Compiler/code generator: Difference between revisions

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{{draft task}}Code Generator
 
A code generator translates the output of the syntax analyzer and/or semantic analyzer
into lower level code, either assembly, object, or virtual.
 
=={{header|Task}}==
{{task heading}}
 
Take the output of the Syntax analyzer [[Compiler/syntax_analyzer|task]] - which is a [[Flatten_a_list|flattened]] Abstract Syntax Tree (AST) - and convert it to virtual machine code, that can be run by the
Line 34:
|-
| style="vertical-align:top" |
<langsyntaxhighlight lang="c">count = 1;
while (count < 10) {
print("count is: ", count, "\n");
count = count + 1;
}</langsyntaxhighlight>
 
| style="vertical-align:top" |
Line 136:
Loading this data into an internal parse tree should be as simple as:
 
<langsyntaxhighlight lang="python">
def load_ast()
line = readline()
Line 158:
right = load_ast()
return make_node(node_type, left, right)
</syntaxhighlight>
</lang>
 
; Output format - refer to the table above
Line 214:
mul
div
mod
lt
gt
le
ge
eq
ne
and
or
 
For the following instructions, the operation is performed against the top entry in the
Line 224 ⟶ 228:
 
neg
not
 
prtc
Line 258 ⟶ 263:
<hr>
__TOC__
 
=={{header|ALGOL 68}}==
Based on the Algol W sample. This generates .NET IL assembler code which can be compiled with the .NET ilasm assembler to generate an exe that can be run under Windows (and presumably Mono though I haven't tried that).
<br>
Apart from the namespace, class and method blocks surrounding the code, the main differences between IL and the task's assembly code are: no "compare-le", "compare-ge", "compare-ne", "prts", "prtc", "prti" and "not" instructions, symbolic labels are used and symbolic local variable names can be used. Some IL instructions have different names, e.g. "stloc" instead of "store". The "prt*" instructions are handled by calling the relevant System.Out.Print method. The compare and "not" instructions are handled by generating equivalent instruction sequences.
<br>
As noted in the code, the generated IL is naive - the sample focuses on simplicity.
<syntaxhighlight lang="algol68"># RC Compiler code generator #
COMMENT
this writes a .NET IL assembler source to standard output.
If the output is stored in a file called "rcsample.il",
it could be compiled the command:
ilasm /opt /out:rcsample.exe rcsample.il
(Note ilasm may not be in the PATH by default(
 
Note: The generated IL is *very* naive
COMMENT
 
# parse tree nodes #
MODE NODE = STRUCT( INT type, REF NODE left, right, INT value );
INT nidentifier = 1, nstring = 2, ninteger = 3, nsequence = 4, nif = 5, nprtc = 6, nprts = 7
, nprti = 8, nwhile = 9, nassign = 10, nnegate = 11, nnot = 12, nmultiply = 13, ndivide = 14
, nmod = 15, nadd = 16, nsubtract = 17, nless = 18, nlessequal = 19, ngreater = 20
, ngreaterequal = 21, nequal = 22, nnotequal = 23, nand = 24, nor = 25
;
# op codes #
INT ofetch = 1, ostore = 2, opush = 3, oadd = 4, osub = 5, omul = 6, odiv = 7, omod = 8
, olt = 9, ogt = 10, ole = 11, oge = 12, oeq = 13, one = 14, oand = 15, oor = 16
, oneg = 17, onot = 18, ojmp = 19, ojz = 20, oprtc = 21, oprts = 22, oprti = 23, opushstr = 24
;
[]INT ndop
= ( -1 , -1 , -1 , -1 , -1 , -1 , -1
, -1 , -1 , -1 , oneg , -1 , omul , odiv
, omod , oadd , osub , olt , -1 , ogt
, -1 , oeq , -1 , oand , oor
) ;
[]STRING ndname
= ( "Identifier" , "String" , "Integer" , "Sequence" , "If" , "Prtc" , "Prts"
, "Prti" , "While" , "Assign" , "Negate" , "Not" , "Multiply" , "Divide"
, "Mod" , "Add" , "Subtract" , "Less" , "LessEqual" , "Greater"
, "GreaterEqual" , "Equal" , "NotEqual" , "And" , "Or"
) ;
[]STRING opname
= ( "ldloc ", "stloc ", "ldc.i4 ", "add ", "sub ", "mul ", "div ", "rem "
, "clt ", "cgt ", "?le ", "?ge ", "ceq ", "?ne ", "and ", "or "
, "neg ", "?not ", "br ", "brfalse", "?prtc ", "?prts ", "?prti ", "ldstr "
) ;
# string and identifier arrays - a hash table might be better... #
INT max string number = 1024;
[ 0 : max string number ]STRING identifiers, strings;
FOR s pos FROM 0 TO max string number DO
identifiers[ s pos ] := "";
strings [ s pos ] := ""
OD;
# label number for label generation #
INT next label number := 0;
# returns the next free label number #
PROC new label = INT: next label number +:= 1;
 
# returns a new node with left and right branches #
PROC op node = ( INT op type, REF NODE left, right )REF NODE: HEAP NODE := NODE( op type, left, right, 0 );
# returns a new operand node #
PROC operand node = ( INT op type, value )REF NODE: HEAP NODE := NODE( op type, NIL, NIL, value );
 
# reports an error and stops #
PROC gen error = ( STRING message )VOID:
BEGIN
print( ( message, newline ) );
stop
END # gen error # ;
 
# reads a node from standard input #
PROC read node = REF NODE:
BEGIN
REF NODE result := NIL;
 
# parses a string from line and stores it in a string in the text array #
# - if it is not already present in the specified textElement list. #
# returns the position of the string in the text array #
PROC read string = ( REF[]STRING text list, CHAR terminator )INT:
BEGIN
# get the text of the string #
STRING str := line[ l pos ];
l pos +:= 1;
WHILE IF l pos <= UPB line THEN line[ l pos ] /= terminator ELSE FALSE FI DO
str +:= line[ l pos ];
l pos +:= 1
OD;
IF l pos > UPB line THEN gen error( "Unterminated String in node file: (" + line + ")." ) FI;
# attempt to find the text in the list of strings/identifiers #
INT t pos := LWB text list;
BOOL found := FALSE;
INT result := LWB text list - 1;
FOR t pos FROM LWB text list TO UPB text list WHILE NOT found DO
IF found := text list[ t pos ] = str THEN
# found the string #
result := t pos
ELIF text list[ t pos ] = "" THEN
# have an empty slot for ther string #
found := TRUE;
text list[ t pos ] := str;
result := t pos
FI
OD;
IF NOT found THEN gen error( "Out of string space." ) FI;
result
END # read string # ;
# gets an integer from the line - no checks for valid digits #
PROC read integer = INT:
BEGIN
INT n := 0;
WHILE line[ l pos ] /= " " DO
( n *:= 10 ) +:= ( ABS line[ l pos ] - ABS "0" );
l pos +:= 1
OD;
n
END # read integer # ;
 
STRING line, name;
INT l pos := 1, nd type := -1;
read( ( line, newline ) );
line +:= " ";
# get the node type name #
WHILE line[ l pos ] = " " DO l pos +:= 1 OD;
name := "";
WHILE IF l pos > UPB line THEN FALSE ELSE line[ l pos ] /= " " FI DO
name +:= line[ l pos ];
l pos +:= 1
OD;
# determine the node type #
nd type := LWB nd name;
IF name /= ";" THEN
# not a null node #
WHILE IF nd type <= UPB nd name THEN name /= nd name[ nd type ] ELSE FALSE FI DO nd type +:= 1 OD;
IF nd type > UPB nd name THEN gen error( "Malformed node: (" + line + ")." ) FI;
# handle the additional parameter for identifier/string/integer, or sub-nodes for operator nodes #
IF nd type = ninteger OR nd type = nidentifier OR nd type = nstring THEN
WHILE line[ l pos ] = " " DO l pos +:= 1 OD;
IF nd type = ninteger THEN result := operand node( nd type, read integer )
ELIF nd type = nidentifier THEN result := operand node( nd type, read string( identifiers, " " ) )
ELSE # nd type = nString # result := operand node( nd type, read string( strings, """" ) )
FI
ELSE
# operator node #
REF NODE left node = read node;
result := op node( nd type, left node, read node )
FI
FI;
result
END # read node # ;
 
# returns a formatted op code for code generation #
PROC operation = ( INT op code )STRING: " " + op name[ op code ] + " ";
# defines the specified label #
PROC define label = ( INT label number )VOID: print( ( "lbl_", whole( label number, 0 ), ":", newline ) );
# generates code to load a string value #
PROC gen load string = ( INT value )VOID:
BEGIN
print( ( operation( opushstr ), " ", strings[ value ], """", newline ) )
END # push string # ;
# generates code to load a constant value #
PROC gen load constant = ( INT value )VOID: print( ( operation( opush ), " ", whole( value, 0 ), newline ) );
# generates an operation acting on an address #
PROC gen data op = ( INT op, address )VOID: print( ( operation( op ), " l_", identifiers[ address ], newline ) );
# generates a nullary operation #
PROC gen op 0 = ( INT op )VOID: print( ( operation( op ), newline ) );
# generates a "not" instruction sequence #
PROC gen not = VOID:
BEGIN
gen load constant( 0 );
print( ( operation( oeq ), newline ) )
END # gen not # ;
# generates a negated condition #
PROC gen not op = ( INT op, REF NODE n )VOID:
BEGIN
gen( left OF n );
gen( right OF n );
gen op 0( op );
gen not
END # gen not op # ;
# generates a jump operation #
PROC gen jump = ( INT op, label )VOID: print( ( operation( op ), " lbl_", whole( label, 0 ), newline ) );
# generates code to output something to System.Console.Out #
PROC gen output = ( REF NODE n, STRING output type )VOID:
BEGIN
print( ( " call " ) );
print( ( "class [mscorlib]System.IO.TextWriter [mscorlib]System.Console::get_Out()", newline ) );
gen( left OF n );
print( ( " callvirt " ) );
print( ( "instance void [mscorlib]System.IO.TextWriter::Write(", output type, ")", newline ) )
END # gen output # ;
 
# generates the code header - assembly info, namespace, class and start of the Main method #
PROC code header = VOID:
BEGIN
print( ( ".assembly extern mscorlib { auto }", newline ) );
print( ( ".assembly RccSample {}", newline ) );
print( ( ".module RccSample.exe", newline ) );
print( ( ".namespace Rcc.Sample", newline ) );
print( ( "{", newline ) );
print( ( " .class public auto ansi Program extends [mscorlib]System.Object", newline ) );
print( ( " {", newline ) );
print( ( " .method public static void Main() cil managed", newline ) );
print( ( " {", newline ) );
print( ( " .entrypoint", newline ) );
# output the local variables #
BOOL have locals := FALSE;
STRING local prefix := " .locals init (int32 l_";
FOR s pos FROM LWB identifiers TO UPB identifiers WHILE identifiers[ s pos ] /= "" DO
print( ( local prefix, identifiers[ s pos ], newline ) );
local prefix := " ,int32 l_";
have locals := TRUE
OD;
IF have locals THEN
# there were some local variables defined - output the terminator #
print( ( " )", newline ) )
FI
END # code header # ;
 
# generates code for the node n #
PROC gen = ( REF NODE n )VOID:
IF n IS REF NODE( NIL ) THEN # null node #
SKIP
ELIF type OF n = nidentifier THEN # load identifier #
gen data op( ofetch, value OF n )
ELIF type OF n = nstring THEN # load string #
gen load string( value OF n )
ELIF type OF n = ninteger THEN # load integer #
gen load constant( value OF n )
ELIF type OF n = nsequence THEN # list #
gen( left OF n );
gen( right OF n )
ELIF type OF n = nif THEN # if-else #
INT else label := new label;
gen( left OF n );
gen jump( ojz, else label );
gen( left OF right OF n );
IF right OF right OF n IS REF NODE( NIL ) THEN
# no "else" part #
define label( else label )
ELSE
# have an "else" part #
INT end if label := new label;
gen jump( ojmp, end if label );
define label( else label );
gen( right OF right OF n );
define label( end if label )
FI
ELIF type OF n = nwhile THEN # while-loop #
INT loop label := new label;
INT exit label := new label;
define label( loop label );
gen( left OF n );
gen jump( ojz, exit label );
gen( right OF n );
gen jump( ojmp, loop label );
define label( exit label )
ELIF type OF n = nassign THEN # assignment #
gen( right OF n );
gen data op( ostore, value OF left OF n )
ELIF type OF n = nnot THEN # bolean not #
gen( left OF n );
gen not
ELIF type OF n = ngreaterequal THEN # compare >= #
gen not op( olt, n )
ELIF type OF n = nnotequal THEN # compare not = #
gen not op( oeq, n )
ELIF type OF n = nlessequal THEN # compare <= #
gen not op( ogt, n )
ELIF type OF n = nprts THEN # print string #
gen output( n, "string" )
ELIF type OF n = nprtc THEN # print character #
gen output( n, "char" )
ELIF type OF n = nprti THEN # print integer #
gen output( n, "int32" )
ELSE # everything else #
gen( left OF n );
gen( right OF n ); # right will be null for a unary op so no code will be generated #
print( ( operation( ndop( type OF n ) ), newline ) )
FI # gen # ;
 
# generates the code trailer - return instruction, end of Main method, end of class and end of namespace #
PROC code trailer = VOID:
BEGIN
print( ( " ret", newline ) );
print( ( " } // Main method", newline ) );
print( ( " } // Program class", newline ) );
print( ( "} // Rcc.Sample namespace", newline ) )
END # code trailer # ;
 
# parse the output from the syntax analyser and generate code from the parse tree #
REF NODE code = read node;
code header;
gen( code );
code trailer</syntaxhighlight>
{{out}}
<pre>
.assembly extern mscorlib { auto }
.assembly RccSample {}
.module RccSample.exe
.namespace Rcc.Sample
{
.class public auto ansi Program extends [mscorlib]System.Object
{
.method public static void Main() cil managed
{
.entrypoint
.locals init (int32 l_count
)
ldc.i4 1
stloc l_count
lbl_1:
ldloc l_count
ldc.i4 10
clt
brfalse lbl_2
call class [mscorlib]System.IO.TextWriter [mscorlib]System.Console::get_Out()
ldstr "count is: "
callvirt instance void [mscorlib]System.IO.TextWriter::Write(string)
call class [mscorlib]System.IO.TextWriter [mscorlib]System.Console::get_Out()
ldloc l_count
callvirt instance void [mscorlib]System.IO.TextWriter::Write(int32)
call class [mscorlib]System.IO.TextWriter [mscorlib]System.Console::get_Out()
ldstr "\n"
callvirt instance void [mscorlib]System.IO.TextWriter::Write(string)
ldloc l_count
ldc.i4 1
add
stloc l_count
br lbl_1
lbl_2:
ret
} // Main method
} // Program class
} // Rcc.Sample namespace
</pre>
 
=={{header|ALGOL W}}==
<langsyntaxhighlight lang="algolw">begin % code generator %
% parse tree nodes %
record node( integer type
Line 625 ⟶ 966:
genOp0( oHalt );
emitCode
end.</langsyntaxhighlight>
{{out}}
The While Counter example
Line 651 ⟶ 992:
65 halt
</pre>
 
=={{header|ATS}}==
For ATS2 with a garbage collector.
<syntaxhighlight lang="ats">
(* The Rosetta Code code generator in ATS2. *)
 
(* Usage: gen [INPUTFILE [OUTPUTFILE]]
If INPUTFILE or OUTPUTFILE is "-" or missing, then standard input
or standard output is used, respectively. *)
 
(* Note: you might wish to add code to catch exceptions and print nice
messages. *)
 
(*------------------------------------------------------------------*)
 
#define ATS_DYNLOADFLAG 0
 
#include "share/atspre_staload.hats"
staload UN = "prelude/SATS/unsafe.sats"
 
#define NIL list_vt_nil ()
#define :: list_vt_cons
 
%{^
/* alloca(3) is needed for ATS exceptions. */
#include <alloca.h>
%}
 
exception internal_error of ()
exception bad_ast_node_type of string
exception premature_end_of_input of ()
exception bad_number_field of string
exception missing_identifier_field of ()
exception bad_quoted_string of string
 
(* Some implementations that are likely missing from the prelude. *)
implement
g0uint2int<sizeknd, llintknd> x =
$UN.cast x
implement
g0uint2uint<sizeknd, ullintknd> x =
$UN.cast x
implement
g0uint2int<ullintknd, llintknd> x =
$UN.cast x
 
(*------------------------------------------------------------------*)
 
extern fn {}
skip_characters$skipworthy (c : char) :<> bool
 
fn {}
skip_characters {n : int}
{i : nat | i <= n}
(s : string n,
i : size_t i)
:<> [j : int | i <= j; j <= n]
size_t j =
let
fun
loop {k : int | i <= k; k <= n}
.<n - k>.
(k : size_t k)
:<> [j : int | k <= j; j <= n]
size_t j =
if string_is_atend (s, k) then
k
else if ~skip_characters$skipworthy (string_get_at (s, k)) then
k
else
loop (succ k)
in
loop i
end
 
fn
skip_whitespace {n : int}
{i : nat | i <= n}
(s : string n,
i : size_t i)
:<> [j : int | i <= j; j <= n]
size_t j =
let
implement
skip_characters$skipworthy<> c =
isspace c
in
skip_characters<> (s, i)
end
 
fn
skip_nonwhitespace {n : int}
{i : nat | i <= n}
(s : string n,
i : size_t i)
:<> [j : int | i <= j; j <= n]
size_t j =
let
implement
skip_characters$skipworthy<> c =
~isspace c
in
skip_characters<> (s, i)
end
 
fn
skip_nonquote {n : int}
{i : nat | i <= n}
(s : string n,
i : size_t i)
:<> [j : int | i <= j; j <= n]
size_t j =
let
implement
skip_characters$skipworthy<> c =
c <> '"'
in
skip_characters<> (s, i)
end
 
fn
skip_to_end {n : int}
{i : nat | i <= n}
(s : string n,
i : size_t i)
:<> [j : int | i <= j; j <= n]
size_t j =
let
implement
skip_characters$skipworthy<> c =
true
in
skip_characters<> (s, i)
end
 
(*------------------------------------------------------------------*)
 
fn
substring_equals {n : int}
{i, j : nat | i <= j; j <= n}
(s : string n,
i : size_t i,
j : size_t j,
t : string)
:<> bool =
let
val m = strlen t
in
if j - i <> m then
false (* The substring is the wrong length. *)
else
let
val p_s = ptrcast s
and p_t = ptrcast t
in
0 = $extfcall (int, "strncmp",
ptr_add<char> (p_s, i), p_t, m)
end
end
 
(*------------------------------------------------------------------*)
 
datatype node_type_t =
| NullNode
| Identifier
| String
| Integer
| Sequence
| If
| Prtc
| Prts
| Prti
| While
| Assign
| Negate
| Not
| Multiply
| Divide
| Mod
| Add
| Subtract
| Less
| LessEqual
| Greater
| GreaterEqual
| Equal
| NotEqual
| And
| Or
 
#define ARBITRARY_NODE_ARG 1234
 
datatype ast_node_t =
| ast_node_t_nil
| ast_node_t_nonnil of node_contents_t
where node_contents_t =
@{
node_type = node_type_t,
node_arg = ullint,
node_left = ast_node_t,
node_right = ast_node_t
}
 
fn
get_node_type {n : int}
{i : nat | i <= n}
(s : string n,
i : size_t i)
: [j : int | i <= j; j <= n]
@(node_type_t,
size_t j) =
let
val i_start = skip_whitespace (s, i)
val i_end = skip_nonwhitespace (s, i_start)
 
macdef eq t =
substring_equals (s, i_start, i_end, ,(t))
 
val node_type =
if eq ";" then
NullNode
else if eq "Identifier" then
Identifier
else if eq "String" then
String
else if eq "Integer" then
Integer
else if eq "Sequence" then
Sequence
else if eq "If" then
If
else if eq "Prtc" then
Prtc
else if eq "Prts" then
Prts
else if eq "Prti" then
Prti
else if eq "While" then
While
else if eq "Assign" then
Assign
else if eq "Negate" then
Negate
else if eq "Not" then
Not
else if eq "Multiply" then
Multiply
else if eq "Divide" then
Divide
else if eq "Mod" then
Mod
else if eq "Add" then
Add
else if eq "Subtract" then
Subtract
else if eq "Less" then
Less
else if eq "LessEqual" then
LessEqual
else if eq "Greater" then
Greater
else if eq "GreaterEqual" then
GreaterEqual
else if eq "Equal" then
Equal
else if eq "NotEqual" then
NotEqual
else if eq "And" then
And
else if eq "Or" then
Or
else
let
val s_bad =
strnptr2string
(string_make_substring (s, i_start, i_end - i_start))
in
$raise bad_ast_node_type s_bad
end
in
@(node_type, i_end)
end
 
fn
get_unsigned {n : int}
{i : nat | i <= n}
(s : string n,
i : size_t i)
: [j : int | i <= j; j <= n]
@(ullint,
size_t j) =
let
val i = skip_whitespace (s, i)
val [j : int] j = skip_nonwhitespace (s, i)
in
if j = i then
$raise bad_number_field ""
else
let
fun
loop {k : int | i <= k; k <= j}
(k : size_t k,
v : ullint)
: ullint =
if k = j then
v
else
let
val c = string_get_at (s, k)
in
if ~isdigit c then
let
val s_bad =
strnptr2string
(string_make_substring (s, i, j - i))
in
$raise bad_number_field s_bad
end
else
let
val digit = char2int1 c - char2int1 '0'
val () = assertloc (0 <= digit)
in
loop (succ k, (g1i2u 10 * v) + g1i2u digit)
end
end
in
@(loop (i, g0i2u 0), j)
end
end
 
fn
get_identifier
{n : int}
{i : nat | i <= n}
(s : string n,
i : size_t i)
: [j : int | i <= j; j <= n]
@(string,
size_t j) =
let
val i = skip_whitespace (s, i)
val j = skip_nonwhitespace (s, i)
in
if i = j then
$raise missing_identifier_field ()
else
let
val ident =
strnptr2string (string_make_substring (s, i, j - i))
in
@(ident, j)
end
end
 
fn
get_quoted_string
{n : int}
{i : nat | i <= n}
(s : string n,
i : size_t i)
: [j : int | i <= j; j <= n]
@(string,
size_t j) =
let
val i = skip_whitespace (s, i)
in
if string_is_atend (s, i) then
$raise bad_quoted_string ""
else if string_get_at (s, i) <> '"' then
let
val j = skip_to_end (s, i)
val s_bad =
strnptr2string (string_make_substring (s, i, j - i))
in
$raise bad_quoted_string s_bad
end
else
let
val j = skip_nonquote (s, succ i)
in
if string_is_atend (s, j) then
let
val s_bad =
strnptr2string (string_make_substring (s, i, j - i))
in
$raise bad_quoted_string s_bad
end
else
let
val quoted_string =
strnptr2string
(string_make_substring (s, i, succ j - i))
in
@(quoted_string, succ j)
end
end
end
 
fn
collect_string
{n : int}
(str : string,
strings : &list_vt (string, n) >> list_vt (string, m))
: #[m : int | m == n || m == n + 1]
[str_num : nat | str_num <= m]
size_t str_num =
(* This implementation uses ‘list_vt’ instead of ‘list’, so
appending elements to the end of the list will be both efficient
and safe. It would also have been reasonable to build a ‘list’
backwards and then make a reversed copy. *)
let
fun
find_or_extend
{i : nat | i <= n}
.<n - i>.
(strings1 : &list_vt (string, n - i)
>> list_vt (string, m),
i : size_t i)
: #[m : int | m == n - i || m == n - i + 1]
[j : nat | j <= n]
size_t j =
case+ strings1 of
| ~ NIL =>
let (* The string is not there. Extend the list. *)
prval () = prop_verify {i == n} ()
in
strings1 := (str :: NIL);
i
end
| @ (head :: tail) =>
if head = str then
let (* The string is found. *)
prval () = fold@ strings1
in
i
end
else
let (* Continue looking. *)
val j = find_or_extend (tail, succ i)
prval () = fold@ strings1
in
j
end
 
prval () = lemma_list_vt_param strings
val n = i2sz (length strings)
and j = find_or_extend (strings, i2sz 0)
in
j
end
 
fn
load_ast (inpf : FILEref,
idents : &List_vt string >> _,
strings : &List_vt string >> _)
: ast_node_t =
let
fun
recurs (idents : &List_vt string >> _,
strings : &List_vt string >> _)
: ast_node_t =
if fileref_is_eof inpf then
$raise premature_end_of_input ()
else
let
val s = strptr2string (fileref_get_line_string inpf)
prval () = lemma_string_param s (* String length >= 0. *)
 
val i = i2sz 0
val @(node_type, i) = get_node_type (s, i)
in
case+ node_type of
| NullNode () => ast_node_t_nil ()
| Integer () =>
let
val @(number, _) = get_unsigned (s, i)
in
ast_node_t_nonnil
@{
node_type = node_type,
node_arg = number,
node_left = ast_node_t_nil,
node_right = ast_node_t_nil
}
end
| Identifier () =>
let
val @(ident, _) = get_identifier (s, i)
val arg = collect_string (ident, idents)
in
ast_node_t_nonnil
@{
node_type = node_type,
node_arg = g0u2u arg,
node_left = ast_node_t_nil,
node_right = ast_node_t_nil
}
end
| String () =>
let
val @(quoted_string, _) = get_quoted_string (s, i)
val arg = collect_string (quoted_string, strings)
in
ast_node_t_nonnil
@{
node_type = node_type,
node_arg = g0u2u arg,
node_left = ast_node_t_nil,
node_right = ast_node_t_nil
}
end
| _ =>
let
val node_left = recurs (idents, strings)
val node_right = recurs (idents, strings)
in
ast_node_t_nonnil
@{
node_type = node_type,
node_arg = g1i2u ARBITRARY_NODE_ARG,
node_left = node_left,
node_right = node_right
}
end
end
in
recurs (idents, strings)
end
 
fn
print_strings {n : int}
(outf : FILEref,
strings : !list_vt (string, n))
: void =
let
fun
loop {m : nat}
.<m>.
(strings1 : !list_vt (string, m)) :
void =
case+ strings1 of
| NIL => ()
| head :: tail =>
begin
fprintln! (outf, head);
loop tail
end
 
prval () = lemma_list_vt_param strings
in
loop strings
end
 
(*------------------------------------------------------------------*)
 
#define ARBITRARY_INSTRUCTION_ARG 1234
#define ARBITRARY_JUMP_ARG 123456789
 
typedef instruction_t =
@{
address = ullint,
opcode = string,
arg = llint
}
 
typedef code_t = ref instruction_t
 
vtypedef pjump_t (p : addr) =
(instruction_t @ p,
instruction_t @ p -<lin,prf> void |
ptr p)
vtypedef pjump_t = [p : addr] pjump_t p
 
fn
add_instruction (opcode : string,
arg : llint,
size : uint,
code : &List0_vt code_t >> List1_vt code_t,
pc : &ullint >> _)
: void =
let
val instr =
@{
address = pc,
opcode = opcode,
arg = arg
}
in
code := (ref instr :: code);
pc := pc + g0u2u size
end
 
fn
add_jump (opcode : string,
code : &List0_vt code_t >> List1_vt code_t,
pc : &ullint >> _)
: pjump_t =
let
val instr =
@{
address = pc,
opcode = opcode,
arg = g1i2i ARBITRARY_JUMP_ARG
}
val ref_instr = ref instr
in
code := (ref_instr :: code);
pc := pc + g0u2u 5U;
ref_vtakeout ref_instr
end
 
fn
fill_jump (pjump : pjump_t,
address : ullint)
: void =
let
val @(pf, fpf | p) = pjump
val instr0 = !p
val jump_offset : llint =
let
val from = succ (instr0.address)
and to = address
in
if from <= to then
g0u2i (to - from)
else
~g0u2i (from - to)
end
val instr1 =
@{
address = instr0.address,
opcode = instr0.opcode,
arg = jump_offset
}
val () = !p := instr1
prval () = fpf pf
in
end
 
fn
add_filled_jump (opcode : string,
address : ullint,
code : &List0_vt code_t >> List1_vt code_t,
pc : &ullint >> _)
: void =
let
val pjump = add_jump (opcode, code, pc)
in
fill_jump (pjump, address)
end
 
fn
generate_code (ast : ast_node_t)
: List_vt code_t =
let
fnx
traverse (ast : ast_node_t,
code : &List0_vt code_t >> _,
pc : &ullint >> _)
: void =
(* Generate the code by consing a list. *)
case+ ast of
| ast_node_t_nil () => ()
| ast_node_t_nonnil contents =>
begin
case+ contents.node_type of
| NullNode () => $raise internal_error ()
 
| If () => if_then (contents, code, pc)
| While () => while_do (contents, code, pc)
 
| Sequence () => sequence (contents, code, pc)
| Assign () => assign (contents, code, pc)
 
| Identifier () => immediate ("fetch", contents, code, pc)
| Integer () => immediate ("push", contents, code, pc)
| String () => immediate ("push", contents, code, pc)
 
| Prtc () => unary_op ("prtc", contents, code, pc)
| Prti () => unary_op ("prti", contents, code, pc)
| Prts () => unary_op ("prts", contents, code, pc)
| Negate () => unary_op ("neg", contents, code, pc)
| Not () => unary_op ("not", contents, code, pc)
 
| Multiply () => binary_op ("mul", contents, code, pc)
| Divide () => binary_op ("div", contents, code, pc)
| Mod () => binary_op ("mod", contents, code, pc)
| Add () => binary_op ("add", contents, code, pc)
| Subtract () => binary_op ("sub", contents, code, pc)
| Less () => binary_op ("lt", contents, code, pc)
| LessEqual () => binary_op ("le", contents, code, pc)
| Greater () => binary_op ("gt", contents, code, pc)
| GreaterEqual () => binary_op ("ge", contents, code, pc)
| Equal () => binary_op ("eq", contents, code, pc)
| NotEqual () => binary_op ("ne", contents, code, pc)
| And () => binary_op ("and", contents, code, pc)
| Or () => binary_op ("or", contents, code, pc)
end
and
if_then (contents : node_contents_t,
code : &List0_vt code_t >> _,
pc : &ullint >> _)
: void =
case- (contents.node_right) of
| ast_node_t_nonnil contents1 =>
let
val condition = (contents.node_left)
and true_branch = (contents1.node_left)
and false_branch = (contents1.node_right)
 
(* Generate code to evaluate the condition. *)
val () = traverse (condition, code, pc);
 
(* Generate a conditional jump. Where it goes to will be
filled in later. *)
val pjump = add_jump ("jz", code, pc)
 
(* Generate code for the true branch. *)
val () = traverse (true_branch, code, pc);
in
case+ false_branch of
| ast_node_t_nil () =>
begin (* There is no false branch. *)
(* Fill in the conditional jump to come here. *)
fill_jump (pjump, pc)
end
| ast_node_t_nonnil _ =>
let (* There is a false branch. *)
(* Generate an unconditional jump. Where it goes to will
be filled in later. *)
val pjump1 = add_jump ("jmp", code, pc)
 
(* Fill in the conditional jump to come here. *)
val () = fill_jump (pjump, pc)
 
(* Generate code for the false branch. *)
val () = traverse (false_branch, code, pc);
 
(* Fill in the unconditional jump to come here. *)
val () = fill_jump (pjump1, pc)
in
end
end
and
while_do (contents : node_contents_t,
code : &List0_vt code_t >> _,
pc : &ullint >> _)
: void =
(* I would prefer to implement ‘while’ by putting the
conditional jump at the end, and jumping to it to get into
the loop. However, we need to generate not the code of our
choice, but the reference result. The reference result has
the conditional jump at the top. *)
let
(* Where to jump from the bottom of the loop. *)
val loop_top_address = pc
(* Generate code to evaluate the condition. *)
val () = traverse (contents.node_left, code, pc)
 
(* Generate a conditional jump. It will be filled in later to
go past the end of the loop. *)
val pjump = add_jump ("jz", code, pc)
 
(* Generate code for the loop body. *)
val () = traverse (contents.node_right, code, pc)
 
(* Generate a jump to the top of the loop. *)
val () = add_filled_jump ("jmp", loop_top_address, code, pc)
 
(* Fill in the conditional jump to come here. *)
val () = fill_jump (pjump, pc)
in
end
and
sequence (contents : node_contents_t,
code : &List0_vt code_t >> _,
pc : &ullint >> _)
: void =
begin
traverse (contents.node_left, code, pc);
traverse (contents.node_right, code, pc)
end
and
assign (contents : node_contents_t,
code : &List0_vt code_t >> _,
pc : &ullint >> _)
: void =
case- contents.node_left of
| ast_node_t_nonnil ident_contents =>
let
val variable_no = ident_contents.node_arg
in
traverse (contents.node_right, code, pc);
add_instruction ("store", g0u2i variable_no, 5U, code, pc)
end
and
immediate (opcode : string,
contents : node_contents_t,
code : &List0_vt code_t >> _,
pc : &ullint >> _)
: void =
add_instruction (opcode, g0u2i (contents.node_arg), 5U,
code, pc)
and
unary_op (opcode : string,
contents : node_contents_t,
code : &List0_vt code_t >> _,
pc : &ullint >> _)
: void =
begin
traverse (contents.node_left, code, pc);
add_instruction (opcode, g0i2i ARBITRARY_INSTRUCTION_ARG, 1U,
code, pc)
end
and
binary_op (opcode : string,
contents : node_contents_t,
code : &List0_vt code_t >> _,
pc : &ullint >> _)
: void =
begin
traverse (contents.node_left, code, pc);
traverse (contents.node_right, code, pc);
add_instruction (opcode, g0i2i ARBITRARY_INSTRUCTION_ARG, 1U,
code, pc)
end
 
var code : List_vt code_t = NIL
var pc : ullint = g0i2u 0
in
traverse (ast, code, pc);
add_instruction ("halt", g0i2i ARBITRARY_INSTRUCTION_ARG, 1U,
code, pc);
 
(* The code is a cons-list, in decreasing-address order, so
reverse it to put the instructions in increasing-address
order. *)
list_vt_reverse code
end
 
fn
print_code (outf : FILEref,
code : !List_vt code_t)
: void =
let
fun
loop {n : nat}
.<n>.
(code : !list_vt (code_t, n))
: void =
case+ code of
| NIL => ()
| ref_instr :: tail =>
let
val @{
address = address,
opcode = opcode,
arg = arg
} = !ref_instr
in
fprint! (outf, address, " ");
fprint! (outf, opcode);
if opcode = "push" then
fprint! (outf, " ", arg)
else if opcode = "fetch" || opcode = "store" then
fprint! (outf, " [", arg, "]")
else if opcode = "jmp" || opcode = "jz" then
begin
fprint! (outf, " (", arg, ") ");
if arg < g1i2i 0 then
let
val offset : ullint = g0i2u (~arg)
val () = assertloc (offset <= succ address)
in
fprint! (outf, succ address - offset)
end
else
let
val offset : ullint = g0i2u arg
in
fprint! (outf, succ address + offset)
end
end;
fprintln! (outf);
loop tail
end
 
prval () = lemma_list_vt_param code
in
loop code
end
 
(*------------------------------------------------------------------*)
 
fn
main_program (inpf : FILEref,
outf : FILEref)
: int =
let
var idents : List_vt string = NIL
var strings : List_vt string = NIL
 
val ast = load_ast (inpf, idents, strings)
val code = generate_code ast
 
val () = fprintln! (outf, "Datasize: ", length idents,
" Strings: ", length strings)
val () = print_strings (outf, strings)
val () = print_code (outf, code)
 
val () = free idents
and () = free strings
and () = free code
in
0
end
 
implement
main (argc, argv) =
let
val inpfname =
if 2 <= argc then
$UN.cast{string} argv[1]
else
"-"
val outfname =
if 3 <= argc then
$UN.cast{string} argv[2]
else
"-"
val inpf =
if (inpfname : string) = "-" then
stdin_ref
else
fileref_open_exn (inpfname, file_mode_r)
 
val outf =
if (outfname : string) = "-" then
stdout_ref
else
fileref_open_exn (outfname, file_mode_w)
in
main_program (inpf, outf)
end
 
(*------------------------------------------------------------------*)
</syntaxhighlight>
 
{{out|case=count}}
<pre>$ patscc -o gen -O3 -DATS_MEMALLOC_GCBDW gen-in-ATS.dats -latslib -lgc && ./gen < count.ast
Datasize: 1 Strings: 2
"count is: "
"\n"
0 push 1
5 store [0]
10 fetch [0]
15 push 10
20 lt
21 jz (43) 65
26 push 0
31 prts
32 fetch [0]
37 prti
38 push 1
43 prts
44 fetch [0]
49 push 1
54 add
55 store [0]
60 jmp (-51) 10
65 halt
</pre>
 
=={{header|AWK}}==
Tested with gawk 4.1.1 and mawk 1.3.4.
<syntaxhighlight lang="awk">
function error(msg) {
printf("%s\n", msg)
exit(1)
}
 
function bytes_to_int(bstr, i, sum) {
sum = 0
for (i=word_size-1; i>=0; i--) {
sum *= 256
sum += code[bstr+i]
}
return sum
}
 
function make_node(oper, left, right, value) {
node_type [next_free_node_index] = oper
node_left [next_free_node_index] = left
node_right[next_free_node_index] = right
node_value[next_free_node_index] = value
return next_free_node_index ++
}
 
function make_leaf(oper, n) {
return make_node(oper, 0, 0, n)
}
 
function emit_byte(x) {
code[next_free_code_index++] = x
}
 
function emit_word(x, i) {
for (i=0; i<word_size; i++) {
emit_byte(int(x)%256);
x = int(x/256)
}
}
 
function emit_word_at(at, n, i) {
for (i=0; i<word_size; i++) {
code[at+i] = int(n)%256
n = int(n/256)
}
}
 
function hole( t) {
t = next_free_code_index
emit_word(0)
return t
}
 
function fetch_var_offset(name, n) {
if (name in globals) {
n = globals[name]
} else {
globals[name] = globals_n
n = globals_n
globals_n += 1
}
return n
}
 
function fetch_string_offset(the_string, n) {
n = string_pool[the_string]
if (n == "") {
string_pool[the_string] = string_n
n = string_n
string_n += 1
}
return n
}
 
function code_gen(x, n, p1, p2) {
if (x == 0) {
return
} else if (node_type[x] == "nd_Ident") {
emit_byte(FETCH)
n = fetch_var_offset(node_value[x])
emit_word(n)
} else if (node_type[x] == "nd_Integer") {
emit_byte(PUSH)
emit_word(node_value[x])
} else if (node_type[x] == "nd_String") {
emit_byte(PUSH)
n = fetch_string_offset(node_value[x])
emit_word(n)
} else if (node_type[x] == "nd_Assign") {
n = fetch_var_offset(node_value[node_left[x]])
code_gen(node_right[x])
emit_byte(STORE)
emit_word(n)
} else if (node_type[x] == "nd_If") {
code_gen(node_left[x]) # expr
emit_byte(JZ) # if false, jump
p1 = hole() # make room for jump dest
code_gen(node_left[node_right[x]]) # if true statements
if (node_right[node_right[x]] != 0) {
emit_byte(JMP) # jump over else statements
p2 = hole()
}
emit_word_at(p1, next_free_code_index - p1)
if (node_right[node_right[x]] != 0) {
code_gen(node_right[node_right[x]]) # else statements
emit_word_at(p2, next_free_code_index - p2)
}
} else if (node_type[x] == "nd_While") {
p1 =next_free_code_index
code_gen(node_left[x])
emit_byte(JZ)
p2 = hole()
code_gen(node_right[x])
emit_byte(JMP) # jump back to the top
emit_word(p1 - next_free_code_index)
emit_word_at(p2, next_free_code_index - p2)
} else if (node_type[x] == "nd_Sequence") {
code_gen(node_left[x])
code_gen(node_right[x])
} else if (node_type[x] == "nd_Prtc") {
code_gen(node_left[x])
emit_byte(PRTC)
} else if (node_type[x] == "nd_Prti") {
code_gen(node_left[x])
emit_byte(PRTI)
} else if (node_type[x] == "nd_Prts") {
code_gen(node_left[x])
emit_byte(PRTS)
} else if (node_type[x] in operators) {
code_gen(node_left[x])
code_gen(node_right[x])
emit_byte(operators[node_type[x]])
} else if (node_type[x] in unary_operators) {
code_gen(node_left[x])
emit_byte(unary_operators[node_type[x]])
} else {
error("error in code generator - found '" node_type[x] "', expecting operator")
}
}
 
function code_finish() {
emit_byte(HALT)
}
 
function list_code() {
printf("Datasize: %d Strings: %d\n", globals_n, string_n)
# Make sure that arrays are sorted by value in ascending order.
PROCINFO["sorted_in"] = "@val_str_asc"
# This is a dependency on GAWK.
for (k in string_pool)
print(k)
pc = 0
while (pc < next_free_code_index) {
printf("%4d ", pc)
op = code[pc]
pc += 1
if (op == FETCH) {
x = bytes_to_int(pc)
printf("fetch [%d]\n", x);
pc += word_size
} else if (op == STORE) {
x = bytes_to_int(pc)
printf("store [%d]\n", x);
pc += word_size
} else if (op == PUSH) {
x = bytes_to_int(pc)
printf("push %d\n", x);
pc += word_size
} else if (op == ADD) { print("add")
} else if (op == SUB) { print("sub")
} else if (op == MUL) { print("mul")
} else if (op == DIV) { print("div")
} else if (op == MOD) { print("mod")
} else if (op == LT) { print("lt")
} else if (op == GT) { print("gt")
} else if (op == LE) { print("le")
} else if (op == GE) { print("ge")
} else if (op == EQ) { print("eq")
} else if (op == NE) { print("ne")
} else if (op == AND) { print("and")
} else if (op == OR) { print("or")
} else if (op == NEG) { print("neg")
} else if (op == NOT) { print("not")
} else if (op == JMP) {
x = bytes_to_int(pc)
printf("jmp (%d) %d\n", x, pc + x);
pc += word_size
} else if (op == JZ) {
x = bytes_to_int(pc)
printf("jz (%d) %d\n", x, pc + x);
pc += word_size
} else if (op == PRTC) { print("prtc")
} else if (op == PRTI) { print("prti")
} else if (op == PRTS) { print("prts")
} else if (op == HALT) { print("halt")
} else { error("list_code: Unknown opcode '" op "'")
}
} # while pc
}
 
function load_ast( line, line_list, text, n, node_type, value, left, right) {
getline line
n=split(line, line_list)
text = line_list[1]
if (text == ";")
return 0
node_type = all_syms[text]
if (n > 1) {
value = line_list[2]
for (i=3;i<=n;i++)
value = value " " line_list[i]
if (value ~ /^[0-9]+$/)
value = int(value)
return make_leaf(node_type, value)
}
left = load_ast()
right = load_ast()
return make_node(node_type, left, right)
}
 
BEGIN {
all_syms["Identifier" ] = "nd_Ident"
all_syms["String" ] = "nd_String"
all_syms["Integer" ] = "nd_Integer"
all_syms["Sequence" ] = "nd_Sequence"
all_syms["If" ] = "nd_If"
all_syms["Prtc" ] = "nd_Prtc"
all_syms["Prts" ] = "nd_Prts"
all_syms["Prti" ] = "nd_Prti"
all_syms["While" ] = "nd_While"
all_syms["Assign" ] = "nd_Assign"
all_syms["Negate" ] = "nd_Negate"
all_syms["Not" ] = "nd_Not"
all_syms["Multiply" ] = "nd_Mul"
all_syms["Divide" ] = "nd_Div"
all_syms["Mod" ] = "nd_Mod"
all_syms["Add" ] = "nd_Add"
all_syms["Subtract" ] = "nd_Sub"
all_syms["Less" ] = "nd_Lss"
all_syms["LessEqual" ] = "nd_Leq"
all_syms["Greater" ] = "nd_Gtr"
all_syms["GreaterEqual"] = "nd_Geq"
all_syms["Equal" ] = "nd_Eql"
all_syms["NotEqual" ] = "nd_Neq"
all_syms["And" ] = "nd_And"
all_syms["Or" ] = "nd_Or"
 
FETCH=1; STORE=2; PUSH=3; ADD=4; SUB=5; MUL=6;
DIV=7; MOD=8; LT=9; GT=10; LE=11; GE=12;
EQ=13; NE=14; AND=15; OR=16; NEG=17; NOT=18;
JMP=19; JZ=20; PRTC=21; PRTS=22; PRTI=23; HALT=24;
 
operators["nd_Lss"] = LT
operators["nd_Gtr"] = GT
operators["nd_Leq"] = LE
operators["nd_Geq"] = GE
operators["nd_Eql"] = EQ
operators["nd_Neq"] = NE
operators["nd_And"] = AND
operators["nd_Or" ] = OR
operators["nd_Sub"] = SUB
operators["nd_Add"] = ADD
operators["nd_Div"] = DIV
operators["nd_Mul"] = MUL
operators["nd_Mod"] = MOD
 
unary_operators["nd_Negate"] = NEG
unary_operators["nd_Not" ] = NOT
 
next_free_node_index = 1
next_free_code_index = 0
globals_n = 0
string_n = 0
word_size = 4
input_file = "-"
 
if (ARGC > 1)
input_file = ARGV[1]
n = load_ast()
code_gen(n)
code_finish()
list_code()
}
</syntaxhighlight>
{{out|case=count}}
<b>
<pre>Datasize: 1 Strings: 2
"count is: "
"\n"
0 push 1
5 store [0]
10 fetch [0]
15 push 10
20 lt
21 jz (43) 65
26 push 0
31 prts
32 fetch [0]
37 prti
38 push 1
43 prts
44 fetch [0]
49 push 1
54 add
55 store [0]
60 jmp (-51) 10
65 halt</pre>
</b>
 
=={{header|C}}==
Tested with gcc 4.81 and later, compiles warning free with -Wall -Wextra
<langsyntaxhighlight Clang="c">#include <stdlib.h>
#include <stdio.h>
#include <string.h>
Line 1,027 ⟶ 2,651:
 
return 0;
}</langsyntaxhighlight>
 
{{out|case=While counter example}}
Line 1,054 ⟶ 2,678:
</b>
 
=={{header|PhixCOBOL}}==
Code by Steve Williams. Tested with GnuCOBOL 2.2.
Reusing parse.e from the [[Compiler/syntax_analyzer#Phix|Syntax Analyzer task]]<br>
Deviates somewhat from the task specification in that it generates executable machine code.
<lang Phix>--
-- demo\rosetta\Compiler\cgen.e
-- ============================
--
-- The reusable part of cgen.exw
--
 
<syntaxhighlight lang="cobol"> >>SOURCE FORMAT IS FREE
include parse.e
identification division.
*> this code is dedicated to the public domain
*> (GnuCOBOL) 2.3-dev.0
program-id. generator.
environment division.
configuration section.
repository. function all intrinsic.
data division.
working-storage section.
01 program-name pic x(32) value spaces global.
01 input-name pic x(32) value spaces global.
01 input-status pic xx global.
 
01 ast-record global.
global sequence vars = {},
03 ast-type pic x(14).
strings = {},
03 ast-value pic x(48).
stringptrs = {}
03 filler redefines ast-value.
05 asl-left pic 999.
05 asl-right pic 999.
 
01 error-record pic x(64) value spaces global.
global integer chain = 0
global sequence code = {}
 
01 loadstack global.
function var_idx(sequence inode)
03 l pic 99 value 0.
if inode[1]!=tk_Identifier then ?9/0 end if
03 l-lim pic 99 value 64.
string ident = inode[2]
03 load-entry occurs 64.
integer n = find(ident,vars)
05 l-node pic x(14).
if n=0 then
vars05 = append(vars,ident)l-left pic 999.
n05 = length(vars)l-right pic 999.
05 l-link pic 999.
 
01 abstract-syntax-tree global.
03 t pic 999 value 0.
03 t1 pic 999.
03 t-lim pic 999 value 998.
03 filler occurs 998.
05 p1 pic 999.
05 p2 pic 999.
05 p3 pic 999.
05 n1 pic 999.
05 leaf.
07 leaf-type pic x(14).
07 leaf-value pic x(48).
05 node redefines leaf.
07 node-type pic x(14).
07 node-left pic 999.
07 node-right pic 999.
 
01 opcodes global.
03 opFETCH pic x value x'00'.
03 opSTORE pic x value x'01'.
03 opPUSH pic x value x'02'.
03 opADD pic x value x'03'.
03 opSUB pic x value x'04'.
03 opMUL pic x value x'05'.
03 opDIV pic x value x'06'.
03 opMOD pic x value x'07'.
03 opLT pic x value x'08'.
03 opGT pic x value x'09'.
03 opLE pic x value x'0A'.
03 opGE pic x value x'0B'.
03 opEQ pic x value x'0C'.
03 opNE pic x value x'0D'.
03 opAND pic x value x'0E'.
03 opOR pic x value x'0F'.
03 opNEG pic x value x'10'.
03 opNOT pic x value x'11'.
03 opJMP pic x value x'13'.
03 opJZ pic x value x'14'.
03 opPRTC pic x value x'15'.
03 opPRTS pic x value x'16'.
03 opPRTI pic x value x'17'.
03 opHALT pic x value x'18'.
 
01 variables global.
03 v pic 99.
03 v-max pic 99 value 0.
03 v-lim pic 99 value 16.
03 variable-entry occurs 16 pic x(48).
 
01 strings global.
03 s pic 99.
03 s-max pic 99 value 0.
03 s-lim pic 99 value 16.
03 string-entry occurs 16 pic x(48).
 
01 generated-code global.
03 c pic 999 value 1.
03 c1 pic 999.
03 c-lim pic 999 value 512.
03 kode pic x(512).
 
procedure division chaining program-name.
start-generator.
call 'loadast'
if program-name <> spaces
call 'readinput' *> close input-file
end-if
>>d perform print-ast
call 'codegen' using t
call 'emitbyte' using opHALT
>>d call 'showhex' using kode c
call 'listcode'
stop run
.
print-ast.
call 'printast' using t
display 'ast:' upon syserr
display 't=' t
perform varying t1 from 1 by 1 until t1 > t
if leaf-type(t1) = 'Identifier' or 'Integer' or 'String'
display t1 space trim(leaf-type(t1)) space trim(leaf-value(t1)) upon syserr
else
display t1 space node-left(t1) space node-right(t1) space trim(node-type(t1))
upon syserr
end-if
end-perform
.
identification division.
program-id. codegen common recursive.
data division.
working-storage section.
01 r pic ---9.
linkage section.
01 n pic 999.
procedure division using n.
start-codegen.
if n = 0
exit program
end-if
>>d display 'at 'c ' node=' space n space node-type(n) upon syserr
evaluate node-type(n)
when 'Identifier'
call 'emitbyte' using opFetch
call 'variableoffset' using leaf-value(n)
call 'emitword' using v '0'
when 'Integer'
call 'emitbyte' using opPUSH
call 'emitword' using leaf-value(n) '0'
when 'String'
call 'emitbyte' using opPUSH
call 'stringoffset' using leaf-value(n)
call 'emitword' using s '0'
when 'Assign'
call 'codegen' using node-right(n)
call 'emitbyte' using opSTORE
move node-left(n) to n1(n)
call 'variableoffset' using leaf-value(n1(n))
call 'emitword' using v '0'
when 'If'
call 'codegen' using node-left(n) *> conditional expr
call 'emitbyte' using opJZ *> jump to false path or exit
move c to p1(n)
call 'emitword' using '0' '0'
move node-right(n) to n1(n) *> true path
call 'codegen' using node-left(n1(n))
if node-right(n1(n)) <> 0 *> there is a false path
call 'emitbyte' using opJMP *> jump past false path
move c to p2(n)
call 'emitword' using '0' '0'
compute r = c - p1(n) *> fill in jump to false path
call 'emitword' using r p1(n)
call 'codegen' using node-right(n1(n)) *> false path
compute r = c - p2(n) *> fill in jump to exit
call 'emitword' using r p2(n)
else
compute r = c - p1(n)
call 'emitword' using r p1(n) *> fill in jump to exit
end-if
when 'While'
move c to p3(n) *> save address of while start
call 'codegen' using node-left(n) *> conditional expr
call 'emitbyte' using opJZ *> jump to exit
move c to p2(n)
call 'emitword' using '0' '0'
call 'codegen' using node-right(n) *> while body
call 'emitbyte' using opJMP *> jump to while start
compute r = p3(n) - c
call 'emitword' using r '0'
compute r = c - p2(n) *> fill in jump to exit
call 'emitword' using r p2(n)
when 'Sequence'
call 'codegen' using node-left(n)
call 'codegen' using node-right(n)
when 'Prtc'
call 'codegen' using node-left(n)
call 'emitbyte' using opPRTC
when 'Prti'
call 'codegen' using node-left(n)
call 'emitbyte' using opPRTI
when 'Prts'
call 'codegen' using node-left(n)
call 'emitbyte' using opPRTS
when 'Less'
call 'codegen' using node-left(n)
call 'codegen' using node-right(n)
call 'emitbyte' using opLT
when 'Greater'
call 'codegen' using node-left(n)
call 'codegen' using node-right(n)
call 'emitbyte' using opGT
when 'LessEqual'
call 'codegen' using node-left(n)
call 'codegen' using node-right(n)
call 'emitbyte' using opLE
when 'GreaterEqual'
call 'codegen' using node-left(n)
call 'codegen' using node-right(n)
call 'emitbyte' using opGE
when 'Equal'
call 'codegen' using node-left(n)
call 'codegen' using node-right(n)
call 'emitbyte' using opEQ
when 'NotEqual'
call 'codegen' using node-left(n)
call 'codegen' using node-right(n)
call 'emitbyte' using opNE
when 'And'
call 'codegen' using node-left(n)
call 'codegen' using node-right(n)
call 'emitbyte' using opAND
when 'Or'
call 'codegen' using node-left(n)
call 'codegen' using node-right(n)
call 'emitbyte' using opOR
when 'Subtract'
call 'codegen' using node-left(n)
call 'codegen' using node-right(n)
call 'emitbyte' using opSUB
when 'Add'
call 'codegen' using node-left(n)
call 'codegen' using node-right(n)
call 'emitbyte' using opADD
when 'Divide'
call 'codegen' using node-left(n)
call 'codegen' using node-right(n)
call 'emitbyte' using opDIV
when 'Multiply'
call 'codegen' using node-left(n)
call 'codegen' using node-right(n)
call 'emitbyte' using opMUL
when 'Mod'
call 'codegen' using node-left(n)
call 'codegen' using node-right(n)
call 'emitbyte' using opMOD
when 'Negate'
call 'codegen' using node-left(n)
call 'emitbyte' using opNEG
when 'Not'
call 'codegen' using node-left(n)
call 'emitbyte' using opNOT
when other
string 'in generator unknown node type: ' node-type(n) into error-record
call 'reporterror'
end-evaluate
.
end program codegen.
 
identification division.
program-id. variableoffset common.
data division.
linkage section.
01 variable-value pic x(48).
procedure division using variable-value.
start-variableoffset.
perform varying v from 1 by 1
until v > v-max
or variable-entry(v) = variable-value
continue
end-perform
if v > v-lim
string 'in generator variable offset v exceeds ' v-lim into error-record
call 'reporterror'
end-if
if v > v-max
move v to v-max
move variable-value to variable-entry(v)
end-if
.
end program variableoffset.
 
identification division.
program-id. stringoffset common.
data division.
linkage section.
01 string-value pic x(48).
procedure division using string-value.
start-stringoffset.
perform varying s from 1 by 1
until s > s-max
or string-entry(s) = string-value
continue
end-perform
if s > s-lim
string ' generator stringoffset s exceeds ' s-lim into error-record
call 'reporterror'
end-if
if s > s-max
move s to s-max
move string-value to string-entry(s)
end-if
subtract 1 from s *> convert index to offset
.
end program stringoffset.
 
identification division.
program-id. emitbyte common.
data division.
linkage section.
01 opcode pic x.
procedure division using opcode.
start-emitbyte.
if c >= c-lim
string 'in generator emitbyte c exceeds ' c-lim into error-record
call 'reporterror'
end-if
move opcode to kode(c:1)
add 1 to c
.
end program emitbyte.
identification division.
program-id. emitword common.
data division.
working-storage section.
01 word-x.
03 word usage binary-int.
01 loc pic 999.
linkage section.
01 word-value any length.
01 loc-value any length.
procedure division using word-value loc-value.
start-emitword.
if c + length(word) > c-lim
string 'in generator emitword exceeds ' c-lim into error-record
call 'reporterror'
end-if
move numval(word-value) to word
move numval(loc-value) to loc
if loc = 0
move word-x to kode(c:length(word))
add length(word) to c
else
move word-x to kode(loc:length(word))
end-if
.
end program emitword.
 
identification division.
program-id. listcode common.
data division.
working-storage section.
01 word-x.
03 word usage binary-int.
01 address-display pic ---9.
01 address-absolute pic zzz9.
01 data-display pic -(9)9.
01 v-display pic z9.
01 s-display pic z9.
01 c-display pic zzz9.
procedure division.
start-listcode.
move v-max to v-display
move s-max to s-display
display 'Datasize: ' trim(v-display) space 'Strings: ' trim(s-display)
perform varying s from 1 by 1
until s > s-max
display string-entry(s)
end-perform
 
move 1 to c1
perform until c1 >= c
compute c-display = c1 - 1
display c-display space with no advancing
evaluate kode(c1:1)
when opFETCH
add 1 to c1
move kode(c1:4) to word-x
compute address-display = word - 1
display 'fetch [' trim(address-display) ']'
add 3 to c1
when opSTORE
add 1 to c1
move kode(c1:4) to word-x
compute address-display = word - 1
display 'store [' trim(address-display) ']'
add 3 to c1
when opPUSH
add 1 to c1
move kode(c1:4) to word-x
move word to data-display
display 'push ' trim(data-display)
add 3 to c1
when opADD display 'add'
when opSUB display 'sub'
when opMUL display 'mul'
when opDIV display 'div'
when opMOD display 'mod'
when opLT display 'lt'
when opGT display 'gt'
when opLE display 'le'
when opGE display 'ge'
when opEQ display 'eq'
when opNE display 'ne'
when opAND display 'and'
when opOR display 'or'
when opNEG display 'neg'
when opNOT display 'not'
when opJMP
move kode(c1 + 1:length(word)) to word-x
move word to address-display
compute address-absolute = c1 + word
display 'jmp (' trim(address-display) ') ' trim(address-absolute)
add length(word) to c1
when opJZ
move kode(c1 + 1:length(word)) to word-x
move word to address-display
compute address-absolute = c1 + word
display 'jz (' trim(address-display) ') ' trim(address-absolute)
add length(word) to c1
when opPRTC display 'prtc'
when opPRTI display 'prti'
when opPRTS display 'prts'
when opHALT display 'halt'
when other
string 'in generator unknown opcode ' kode(c1:1) into error-record
call 'reporterror'
end-evaluate
add 1 to c1
end-perform
.
end program listcode.
 
identification division.
program-id. loadast common recursive.
procedure division.
start-loadast.
if l >= l-lim
string 'in generator loadast l exceeds ' l-lim into error-record
call 'reporterror'
end-if
add 1 to l
call 'readinput'
evaluate true
when ast-record = ';'
when input-status = '10'
move 0 to return-code
when ast-type = 'Identifier'
when ast-type = 'Integer'
when ast-type = 'String'
call 'makeleaf' using ast-type ast-value
move t to return-code
when ast-type = 'Sequence'
move ast-type to l-node(l)
call 'loadast'
move return-code to l-left(l)
call 'loadast'
move t to l-right(l)
call 'makenode' using l-node(l) l-left(l) l-right(l)
move t to return-code
when other
move ast-type to l-node(l)
call 'loadast'
move return-code to l-left(l)
call 'loadast'
move return-code to l-right(l)
call 'makenode' using l-node(l) l-left(l) l-right(l)
move t to return-code
end-evaluate
subtract 1 from l
.
end program loadast.
 
identification division.
program-id. printast common recursive.
data division.
linkage section.
01 n pic 999.
procedure division using n.
start-printast.
if n = 0
display ';' upon syserr
exit program
end-if
display leaf-type(n) upon syserr
evaluate leaf-type(n)
when 'Identifier'
when 'Integer'
when 'String'
display leaf-type(n) space trim(leaf-value(n)) upon syserr
when other
display node-type(n) upon syserr
call 'printast' using node-left(n)
call 'printast' using node-right(n)
end-evaluate
.
end program printast.
 
identification division.
program-id. makenode common.
data division.
linkage section.
01 parm-type any length.
01 parm-l-left pic 999.
01 parm-l-right pic 999.
procedure division using parm-type parm-l-left parm-l-right.
start-makenode.
if t >= t-lim
string 'in generator makenode t exceeds ' t-lim into error-record
call 'reporterror'
end-if
add 1 to t
move parm-type to node-type(t)
move parm-l-left to node-left(t)
move parm-l-right to node-right(t)
.
end program makenode.
 
identification division.
program-id. makeleaf common.
data division.
linkage section.
01 parm-type any length.
01 parm-value pic x(48).
procedure division using parm-type parm-value.
start-makeleaf.
add 1 to t
if t >= t-lim
string 'in generator makeleaf t exceeds ' t-lim into error-record
call 'reporterror'
end-if
move parm-type to leaf-type(t)
move parm-value to leaf-value(t)
.
end program makeleaf.
 
identification division.
program-id. readinput common.
environment division.
input-output section.
file-control.
select input-file assign using input-name
status is input-status
organization is line sequential.
data division.
file section.
fd input-file.
01 input-record pic x(64).
procedure division.
start-readinput.
if program-name = spaces
move '00' to input-status
accept ast-record on exception move '10' to input-status end-accept
exit program
end-if
if input-name = spaces
string program-name delimited by space '.ast' into input-name
open input input-file
if input-status = '35'
string 'in generator ' trim(input-name) ' not found' into error-record
call 'reporterror'
end-if
end-if
read input-file into ast-record
evaluate input-status
when '00'
continue
when '10'
close input-file
when other
string 'in generator ' trim(input-name) ' unexpected input-status: ' input-status
into error-record
call 'reporterror'
end-evaluate
.
end program readinput.
 
program-id. reporterror common.
procedure division.
start-reporterror.
report-error.
display error-record upon syserr
stop run with error status -1
.
end program reporterror.
 
identification division.
program-id. showhex common.
 
data division.
working-storage section.
01 hex.
03 filler pic x(32) value '000102030405060708090A0B0C0D0E0F'.
03 filler pic x(32) value '101112131415161718191A1B1C1D1E1F'.
03 filler pic x(32) value '202122232425262728292A2B2C2D2E2F'.
03 filler pic x(32) value '303132333435363738393A3B3C3D3E3F'.
03 filler pic x(32) value '404142434445464748494A4B4C4D4E4F'.
03 filler pic x(32) value '505152535455565758595A5B5C5D5E5F'.
03 filler pic x(32) value '606162636465666768696A6B6C6D6E6F'.
03 filler pic x(32) value '707172737475767778797A7B7C7D7E7F'.
03 filler pic x(32) value '808182838485868788898A8B8C8D8E8F'.
03 filler pic x(32) value '909192939495969798999A9B9C9D9E9F'.
03 filler pic x(32) value 'A0A1A2A3A4A5A6A7A8A9AAABACADAEAF'.
03 filler pic x(32) value 'B0B1B2B3B4B5B6B7B8B9BABBBCBDBEBF'.
03 filler pic x(32) value 'C0C1C2C3C4C5C6C7C8C9CACBCCCDCECF'.
03 filler pic x(32) value 'D0D1D2D3D4D5D6D7D8D9DADBDCDDDEDF'.
03 filler pic x(32) value 'E0E1E2E3E4E5E6E7E8E9EAEBECEDEEEF'.
03 filler pic x(32) value 'F0F1F2F3F4F5F6F7F8F9FAFBFCFDFEFF'.
 
01 cdx pic 9999.
01 bdx pic 999.
01 byte-count pic 9.
01 bytes-per-word pic 9 value 4.
01 word-count pic 9.
01 words-per-line pic 9 value 8.
 
linkage section.
01 data-field any length.
01 length-data-field pic 999.
 
procedure division using
by reference data-field
by reference length-data-field.
start-showhex.
move 1 to byte-count
move 1 to word-count
perform varying cdx from 1 by 1
until cdx > length-data-field
compute bdx = 2 * ord(data-field(cdx:1)) - 1 end-compute
display hex(bdx:2) with no advancing upon syserr
add 1 to byte-count end-add
if byte-count > bytes-per-word
display ' ' with no advancing upon syserr
move 1 to byte-count
add 1 to word-count end-add
end-if
if word-count > words-per-line
display ' ' upon syserr
move 1 to word-count
end-if
end-perform
if word-count <> 1
or byte-count <> 1
display ' ' upon syserr
end-if
display ' ' upon syserr
goback
.
end program showhex.
end program generator.</syntaxhighlight>
 
{{out|case=Count}}
<pre>prompt$ ./lexer <testcases/Count | ./parser | ./generator
Datasize: 1 Strings: 2
"count is: "
"\n"
0 push 1
5 store [0]
10 fetch [0]
15 push 10
20 lt
21 jz (43) 65
26 push 0
31 prts
32 fetch [0]
37 prti
38 push 1
43 prts
44 fetch [0]
49 push 1
54 add
55 store [0]
60 jmp (-51) 10
65 halt</pre>
 
=={{header|Forth}}==
Tested with Gforth 0.7.3
<syntaxhighlight lang="forth">CREATE BUF 0 ,
: PEEK BUF @ 0= IF KEY BUF ! THEN BUF @ ;
: GETC PEEK 0 BUF ! ;
: SPACE? DUP BL = SWAP 9 14 WITHIN OR ;
: >SPACE BEGIN PEEK SPACE? WHILE GETC DROP REPEAT ;
: DIGIT? 48 58 WITHIN ;
: >Integer >SPACE 0
BEGIN PEEK DIGIT?
WHILE GETC [CHAR] 0 - SWAP 10 * + REPEAT ;
: SKIP ( xt --)
BEGIN PEEK OVER EXECUTE WHILE GETC DROP REPEAT DROP ;
: WORD ( xt -- c-addr) DUP >R SKIP PAD 1+
BEGIN PEEK R@ EXECUTE INVERT
WHILE GETC OVER C! CHAR+
REPEAT R> SKIP PAD TUCK - 1- PAD C! ;
: INTERN ( c-addr -- c-addr)
HERE TUCK OVER C@ CHAR+ DUP ALLOT CMOVE ;
: "? [CHAR] " = ;
: "TYPE" [CHAR] " EMIT TYPE [CHAR] " EMIT ;
: . 0 .R ;
: 3@ ( addr -- w3 w2 w1)
[ 2 CELLS ]L + DUP @ SWAP CELL - DUP @ SWAP CELL - @ ;
 
CREATE BUF' 12 ALLOT
: PREPEND ( c-addr c -- c-addr) BUF' 1+ C!
COUNT 10 MIN DUP 1+ BUF' C! BUF' 2 + SWAP CMOVE BUF' ;
: >NODE ( c-addr -- n) [CHAR] $ PREPEND FIND
IF EXECUTE ELSE ." unrecognized node " COUNT TYPE CR THEN ;
: NODE ( n left right -- addr) HERE >R , , , R> ;
 
: CONS ( a b l -- l) HERE >R , , , R> ;
: FIRST ( l -- a) [ 2 CELLS ]L + @ ;
: SECOND ( l -- b) CELL+ @ ;
: C=? ( c-addr1 c-addr2 -- t|f) COUNT ROT COUNT COMPARE 0= ;
: LOOKUP ( c-addr l -- n t | c-addr f)
BEGIN DUP WHILE OVER OVER FIRST C=?
IF NIP SECOND TRUE EXIT THEN @
REPEAT DROP FALSE ;
 
CREATE GLOBALS 0 , CREATE STRINGS 0 ,
: DEPTH ( pool -- n) DUP IF SECOND 1+ THEN ;
: FISH ( c-addr pool -- n pool') TUCK LOOKUP IF SWAP
ELSE INTERN OVER DEPTH ROT OVER >R CONS R> SWAP THEN ;
: >Identifier ['] SPACE? WORD GLOBALS @ FISH GLOBALS ! ;
: >String ['] "? WORD STRINGS @ FISH STRINGS ! ;
: >; 0 ;
: HANDLER [CHAR] @ PREPEND FIND DROP ;
: READER ( c-addr -- xt t | f)
[CHAR] > PREPEND FIND DUP 0= IF NIP THEN ;
DEFER GETAST
: READ ( c-addr -- right left) READER
IF EXECUTE 0 ELSE GETAST GETAST THEN SWAP ;
: (GETAST) ['] SPACE? WORD DUP HANDLER >R READ R> NODE ;
' (GETAST) IS GETAST
 
CREATE PC 0 ,
: i32! ( n addr --)
OVER $FF AND OVER C! 1+
OVER 8 RSHIFT $FF AND OVER C! 1+
OVER 16 RSHIFT $FF AND OVER C! 1+
OVER 24 RSHIFT $FF AND OVER C! DROP DROP ;
: i32, ( n --) HERE i32! 4 ALLOT 4 PC +! ;
: i8, ( c --) C, 1 PC +! ;
: i8@+ DUP 1+ SWAP C@ 1 PC +! ;
: i32@+ ( addr -- addr+4 n)
i8@+ >R i8@+ 8 LSHIFT R> OR >R
i8@+ 16 LSHIFT R> OR >R i8@+ 24 LSHIFT R> OR ;
 
CREATE #OPS 0 ,
: OP: CREATE #OPS @ , 1 #OPS +! DOES> @ ;
OP: fetch OP: store OP: push OP: jmp OP: jz
OP: prtc OP: prti OP: prts OP: neg OP: not
OP: add OP: sub OP: mul OP: div OP: mod
OP: lt OP: gt OP: le OP: ge
OP: eq OP: ne OP: and OP: or OP: halt
 
: GEN ( ast --) 3@ EXECUTE ;
: @; ( r l) DROP DROP ;
: @Identifier fetch i8, i32, DROP ;
: @Integer push i8, i32, DROP ;
: @String push i8, i32, DROP ;
: @Prtc GEN prtc i8, DROP ;
: @Prti GEN prti i8, DROP ;
: @Prts GEN prts i8, DROP ;
: @Not GEN not i8, DROP ;
: @Negate GEN neg i8, DROP ;
: @Sequence GEN GEN ;
: @Assign CELL+ @ >R GEN store i8, R> i32, ;
: @While PC @ SWAP GEN jz i8, HERE >R 0 i32,
SWAP GEN jmp i8, i32, PC @ R> i32! ;
: @If GEN jz i8, HERE >R 0 i32,
CELL+ DUP CELL+ @ DUP @ ['] @; = IF DROP @
ELSE SWAP @ GEN jmp i8, HERE 0 i32, PC @ R> i32! >R
THEN GEN PC @ R> i32! ;
: BINARY >R GEN GEN R> i8, ;
: @Subtract sub BINARY ; : @Add add BINARY ;
: @Mod mod BINARY ; : @Multiply mul BINARY ;
: @Divide div BINARY ;
: @Less lt BINARY ; : @LessEqual le BINARY ;
: @Greater gt BINARY ; : @GreaterEqual ge BINARY ;
: @Equal eq BINARY ; : @NotEqual ne BINARY ;
: @And and BINARY ; : @Or or BINARY ;
 
: REVERSE ( l -- l') 0 SWAP
BEGIN DUP WHILE TUCK DUP @ ROT ROT ! REPEAT DROP ;
: .STRINGS STRINGS @ REVERSE BEGIN DUP
WHILE DUP FIRST COUNT "TYPE" CR @ REPEAT DROP ;
: .HEADER ( --)
." Datasize: " GLOBALS @ DEPTH . SPACE
." Strings: " STRINGS @ DEPTH . CR .STRINGS ;
: GENERATE ( ast -- addr u)
0 PC ! HERE >R GEN halt i8, R> PC @ ;
: ," [CHAR] " PARSE TUCK HERE SWAP CMOVE ALLOT ;
CREATE "OPS"
," fetch store push jmp jz prtc prti prts "
," neg not add sub mul div mod lt "
," gt le ge eq ne and or halt "
: .i32 i32@+ . ;
: .[i32] [CHAR] [ EMIT .i32 [CHAR] ] EMIT ;
: .off [CHAR] ( EMIT PC @ >R i32@+ DUP R> - . [CHAR] ) EMIT
SPACE . ;
CREATE .INT ' .[i32] , ' .[i32] , ' .i32 , ' .off , ' .off ,
: EMIT ( addr u --) >R 0 PC !
BEGIN PC @ R@ <
WHILE PC @ 5 .R SPACE i8@+
DUP 6 * "OPS" + 6 TYPE
DUP 5 < IF CELLS .INT + @ EXECUTE ELSE DROP THEN CR
REPEAT DROP R> DROP ;
GENERATE EMIT BYE</syntaxhighlight>
Passes all tests.
 
=={{header|Fortran}}==
{{works with|gfortran|11.2.1}}
Fortran 2008/2018 code with C preprocessing. On case-sensitive systems, if you call the source file gen.F90, with a capital F, then gfortran will know to use the C preprocessor.
 
<syntaxhighlight lang="fortran">module compiler_type_kinds
use, intrinsic :: iso_fortran_env, only: int32
use, intrinsic :: iso_fortran_env, only: int64
 
implicit none
private
 
! Synonyms.
integer, parameter, public :: size_kind = int64
integer, parameter, public :: length_kind = size_kind
integer, parameter, public :: nk = size_kind
 
! Synonyms for character capable of storing a Unicode code point.
integer, parameter, public :: unicode_char_kind = selected_char_kind ('ISO_10646')
integer, parameter, public :: ck = unicode_char_kind
 
! Synonyms for integers capable of storing a Unicode code point.
integer, parameter, public :: unicode_ichar_kind = int32
integer, parameter, public :: ick = unicode_ichar_kind
 
! Synonyms for integers in the virtual machine or the interpreter’s
! runtime. (The Rosetta Code task says integers in the virtual
! machine are 32-bit, but there is nothing in the task that prevents
! us using 64-bit integers in the compiler and interpreter.)
integer, parameter, public :: runtime_int_kind = int64
integer, parameter, public :: rik = runtime_int_kind
end module compiler_type_kinds
 
module helper_procedures
use, non_intrinsic :: compiler_type_kinds, only: nk, rik, ck
 
implicit none
private
 
public :: new_storage_size
public :: next_power_of_two
 
public :: isspace
public :: quoted_string
 
public :: int32_to_vm_bytes
public :: uint32_to_vm_bytes
public :: int32_from_vm_bytes
public :: uint32_from_vm_bytes
 
character(1, kind = ck), parameter :: horizontal_tab_char = char (9, kind = ck)
character(1, kind = ck), parameter :: linefeed_char = char (10, kind = ck)
character(1, kind = ck), parameter :: vertical_tab_char = char (11, kind = ck)
character(1, kind = ck), parameter :: formfeed_char = char (12, kind = ck)
character(1, kind = ck), parameter :: carriage_return_char = char (13, kind = ck)
character(1, kind = ck), parameter :: space_char = ck_' '
 
! The following is correct for Unix and its relatives.
character(1, kind = ck), parameter :: newline_char = linefeed_char
 
character(1, kind = ck), parameter :: backslash_char = char (92, kind = ck)
 
contains
 
elemental function new_storage_size (length_needed) result (size)
integer(kind = nk), intent(in) :: length_needed
integer(kind = nk) :: size
 
! Increase storage by orders of magnitude.
 
if (2_nk**32 < length_needed) then
size = huge (1_nk)
else
size = next_power_of_two (length_needed)
end if
end function new_storage_size
return n
end function
 
elemental function string_idxnext_power_of_two (sequencex) inoderesult (y)
integer(kind = nk), intent(in) :: x
if inode[1]!=tk_String then ?9/0 end if
string sinteger(kind = inode[2]nk) :: y
 
integer n = find(s,strings)
if n=0 then!
! It is assumed that no more than 64 bits are used.
strings = append(strings,s)
!
stringptrs = append(stringptrs,0)
! The branch-free algorithm is that of
n = length(strings)
! https://archive.is/nKxAc#RoundUpPowerOf2
!
! Fill in bits until one less than the desired power of two is
! reached, and then add one.
!
 
y = x - 1
y = ior (y, ishft (y, -1))
y = ior (y, ishft (y, -2))
y = ior (y, ishft (y, -4))
y = ior (y, ishft (y, -8))
y = ior (y, ishft (y, -16))
y = ior (y, ishft (y, -32))
y = y + 1
end function next_power_of_two
 
elemental function isspace (ch) result (bool)
character(1, kind = ck), intent(in) :: ch
logical :: bool
 
bool = (ch == horizontal_tab_char) .or. &
& (ch == linefeed_char) .or. &
& (ch == vertical_tab_char) .or. &
& (ch == formfeed_char) .or. &
& (ch == carriage_return_char) .or. &
& (ch == space_char)
end function isspace
 
function quoted_string (str) result (qstr)
character(*, kind = ck), intent(in) :: str
character(:, kind = ck), allocatable :: qstr
 
integer(kind = nk) :: n, i, j
 
! Compute n = the size of qstr.
n = 2_nk
do i = 1_nk, len (str, kind = nk)
select case (str(i:i))
case (newline_char, backslash_char)
n = n + 2
case default
n = n + 1
end select
end do
 
allocate (character(n, kind = ck) :: qstr)
 
! Quote the string.
qstr(1:1) = ck_'"'
j = 2_nk
do i = 1_nk, len (str, kind = nk)
select case (str(i:i))
case (newline_char)
qstr(j:j) = backslash_char
qstr((j + 1):(j + 1)) = ck_'n'
j = j + 2
case (backslash_char)
qstr(j:j) = backslash_char
qstr((j + 1):(j + 1)) = backslash_char
j = j + 2
case default
qstr(j:j) = str(i:i)
j = j + 1
end select
end do
if (j /= n) error stop ! Check code correctness.
qstr(n:n) = ck_'"'
end function quoted_string
 
subroutine int32_to_vm_bytes (n, bytes, i)
integer(kind = rik), intent(in) :: n
character(1), intent(inout) :: bytes(0:*)
integer(kind = rik), intent(in) :: i
 
!
! The virtual machine is presumed to be little-endian. Because I
! slightly prefer little-endian.
!
 
bytes(i) = achar (ibits (n, 0, 8))
bytes(i + 1) = achar (ibits (n, 8, 8))
bytes(i + 2) = achar (ibits (n, 16, 8))
bytes(i + 3) = achar (ibits (n, 24, 8))
end subroutine int32_to_vm_bytes
 
subroutine uint32_to_vm_bytes (n, bytes, i)
integer(kind = rik), intent(in) :: n
character(1), intent(inout) :: bytes(0:*)
integer(kind = rik), intent(in) :: i
 
call int32_to_vm_bytes (n, bytes, i)
end subroutine uint32_to_vm_bytes
 
subroutine int32_from_vm_bytes (n, bytes, i)
integer(kind = rik), intent(out) :: n
character(1), intent(in) :: bytes(0:*)
integer(kind = rik), intent(in) :: i
 
!
! The virtual machine is presumed to be little-endian. Because I
! slightly prefer little-endian.
!
 
call uint32_from_vm_bytes (n, bytes, i)
if (ibits (n, 31, 1) == 1) then
! Extend the sign bit.
n = ior (n, not ((2_rik ** 32) - 1))
end if
end subroutine int32_from_vm_bytes
return n
 
end function
subroutine uint32_from_vm_bytes (n, bytes, i)
integer(kind = rik), intent(out) :: n
character(1), intent(in) :: bytes(0:*)
integer(kind = rik), intent(in) :: i
 
!
! The virtual machine is presumed to be little-endian. Because I
! slightly prefer little-endian.
!
 
integer(kind = rik) :: n0, n1, n2, n3
 
n0 = iachar (bytes(i), kind = rik)
n1 = ishft (iachar (bytes(i + 1), kind = rik), 8)
n2 = ishft (iachar (bytes(i + 2), kind = rik), 16)
n3 = ishft (iachar (bytes(i + 3), kind = rik), 24)
n = ior (n0, ior (n1, ior (n2, n3)))
end subroutine uint32_from_vm_bytes
 
end module helper_procedures
 
module string_buffers
use, intrinsic :: iso_fortran_env, only: error_unit
use, intrinsic :: iso_fortran_env, only: int64
use, non_intrinsic :: compiler_type_kinds, only: nk, ck, ick
use, non_intrinsic :: helper_procedures
 
implicit none
private
 
public :: strbuf_t
public :: skip_whitespace
public :: skip_non_whitespace
public :: skip_whitespace_backwards
public :: at_end_of_line
 
type :: strbuf_t
integer(kind = nk), private :: len = 0
!
! ‘chars’ is made public for efficient access to the individual
! characters.
!
character(1, kind = ck), allocatable, public :: chars(:)
contains
procedure, pass, private :: ensure_storage => strbuf_t_ensure_storage
procedure, pass :: to_unicode_full_string => strbuf_t_to_unicode_full_string
procedure, pass :: to_unicode_substring => strbuf_t_to_unicode_substring
procedure, pass :: length => strbuf_t_length
procedure, pass :: set => strbuf_t_set
procedure, pass :: append => strbuf_t_append
generic :: to_unicode => to_unicode_full_string
generic :: to_unicode => to_unicode_substring
generic :: assignment(=) => set
end type strbuf_t
 
contains
 
function strbuf_t_to_unicode_full_string (strbuf) result (s)
class(strbuf_t), intent(in) :: strbuf
character(:, kind = ck), allocatable :: s
 
!
! This does not actually ensure that the string is valid Unicode;
! any 31-bit ‘character’ is supported.
!
 
integer(kind = nk) :: i
 
allocate (character(len = strbuf%len, kind = ck) :: s)
do i = 1, strbuf%len
s(i:i) = strbuf%chars(i)
end do
end function strbuf_t_to_unicode_full_string
 
function strbuf_t_to_unicode_substring (strbuf, i, j) result (s)
!
! ‘Extreme’ values of i and j are allowed, as shortcuts for ‘from
! the beginning’, ‘up to the end’, or ‘empty substring’.
!
class(strbuf_t), intent(in) :: strbuf
integer(kind = nk), intent(in) :: i, j
character(:, kind = ck), allocatable :: s
 
!
! This does not actually ensure that the string is valid Unicode;
! any 31-bit ‘character’ is supported.
!
 
integer(kind = nk) :: i1, j1
integer(kind = nk) :: n
integer(kind = nk) :: k
 
i1 = max (1_nk, i)
j1 = min (strbuf%len, j)
n = max (0_nk, (j1 - i1) + 1_nk)
 
allocate (character(n, kind = ck) :: s)
do k = 1, n
s(k:k) = strbuf%chars(i1 + (k - 1_nk))
end do
end function strbuf_t_to_unicode_substring
 
elemental function strbuf_t_length (strbuf) result (n)
class(strbuf_t), intent(in) :: strbuf
integer(kind = nk) :: n
 
n = strbuf%len
end function strbuf_t_length
 
subroutine strbuf_t_ensure_storage (strbuf, length_needed)
class(strbuf_t), intent(inout) :: strbuf
integer(kind = nk), intent(in) :: length_needed
 
integer(kind = nk) :: len_needed
integer(kind = nk) :: new_size
type(strbuf_t) :: new_strbuf
 
len_needed = max (length_needed, 1_nk)
 
if (.not. allocated (strbuf%chars)) then
function gen_size(object t)
! Initialize a new strbuf%chars array.
-- note: must be kept precisely in sync with gen_rec!
new_size = new_storage_size (len_needed)
-- (relentlessly tested via estsize/actsize)
allocate (strbuf%chars(1:new_size))
integer size = 0
else if t!=NULL(ubound (strbuf%chars, 1) < len_needed) then
! Allocate a new strbuf%chars array, larger than the current
integer n_type = t[1]
! one, but containing the same characters.
string node_type = tkNames[n_type]
new_size = new_storage_size (len_needed)
switch n_type do
allocate (new_strbuf%chars(1:new_size))
case tk_Sequence:
new_strbuf%chars(1:strbuf%len) = strbuf%chars(1:strbuf%len)
size += gen_size(t[2])
call move_alloc (new_strbuf%chars, strbuf%chars)
size += gen_size(t[3])
case tk_assign:
size += gen_size(t[3])+6
case tk_Integer:
size += 5
case tk_Identifier:
size += 6
case tk_String:
size += 5
case tk_while:
-- emit: @@:<condition><topjmp(@f)><body><tailjmp(@b)>@@:
size += gen_size(t[2])+3
integer body = gen_size(t[3])
integer stail = iff(size+body+2>128?5:2)
integer stop = iff(body+stail >127?6:2)
size += stop+body+stail
case tk_lt:
case tk_le:
case tk_ne:
case tk_eq:
case tk_gt:
case tk_ge:
size += gen_size(t[2])
size += gen_size(t[3])
size += 10
case tk_add:
case tk_and:
case tk_sub:
size += gen_size(t[2])
size += gen_size(t[3])
size += 4
case tk_mul:
size += gen_size(t[2])
size += gen_size(t[3])
size += 5
case tk_div:
case tk_mod:
size += gen_size(t[2])
size += gen_size(t[3])
size += 6
case tk_putc:
case tk_Printi:
case tk_Prints:
size += gen_size(t[2])
size += 5
case tk_if:
size += gen_size(t[2])+3
if t[3][1]!=tk_if then ?9/0 end if
integer truesize = gen_size(t[3][2])
integer falsesize = gen_size(t[3][3])
integer elsejmp = iff(falsesize=0?0:iff(falsesize>127?5:2))
integer mainjmp = iff(truesize+elsejmp>127?6:2)
size += mainjmp+truesize+elsejmp+falsesize
case tk_not:
size += gen_size(t[2])
size += 9
case tk_neg:
size += gen_size(t[2])
size += 4
else:
?9/0
end switch
end if
end subroutine strbuf_t_ensure_storage
return size
end function
 
subroutine strbuf_t_set (dst, src)
procedure gen_rec(object t)
class(strbuf_t), intent(inout) :: dst
-- the recursive part of code_gen
class(*), intent(in) :: src
if t!=NULL then
 
integer initsize = length(code)
integer estsize(kind = gen_size(tnk) :: -- (test the gen_size function)n
integer(kind = nk) :: i
integer n_type = t[1]
 
string node_type = tkNames[n_type]
select type (src)
switch n_type do
type is (character(*, kind = ck))
case tk_Sequence:
n = len (src, kind = gen_rec(t[2]nk)
call gen_recdst%ensure_storage(t[3]n)
do i = 1, case tk_assign:n
integer ndst%chars(i) = var_idxsrc(t[2]i:i)
end gen_rec(t[3])do
dst%len = n
code &= {0o217,0o005,chain,1,n,0} -- pop [i]
type is (character(*))
chain = length(code)-3
n = len (src, kind case= tk_Integer:nk)
call integer dst%ensure_storage(n = t[2])
do i = 1, n
code &= 0o150&int_to_bytes(n) -- push imm32
dst%chars(i) = case tk_whilesrc(i:i)
end do
-- emit: @@:<condition><topjmp(@f)><body><tailjmp(@b)>@@:
integer looptopdst%len = length(code)n
class is (strbuf_t)
gen_rec(t[2])
n = src%len
code &= {0o130, -- pop eax
call dst%ensure_storage(n)
0o205,0o300} -- test eax,eax
integer bodysizedst%chars(1:n) = gen_sizesrc%chars(t[3]1:n)
dst%len = n
-- can we use short jumps?
class default
-- disclaimer: size calcs are not heavily tested; if in
error stop
-- doubt reduce 128/7 by 8, and if that works
end select
-- then yep, you just found a boundary case.
end subroutine strbuf_t_set
integer stail = iff(length(code)+bodysize+4-looptop>128?5:2)
 
integer offset = bodysize+stail
subroutine strbuf_t_append (dst, src)
integer stop = iff(offset>127?6:2)
class(strbuf_t), intent(inout) :: dst
if stop=2 then
class(*), intent(in) :: src
code &= {0o164,offset} -- jz (short) end
 
else
integer(kind = nk) :: n_dst, n_src, n
code &= {0o017,0o204}&int_to_bytes(offset) -- jz (long) end
integer(kind = nk) :: i
end if
 
gen_rec(t[3])
select type (src)
offset = looptop-(length(code)+stail)
type is (character(*, kind = ck))
if stail=2 then
n_dst = dst%len
code &= 0o353&offset -- jmp looptop (short)
n_src = len (src, kind = elsenk)
n = n_dst + n_src
code &= 0o351&int_to_bytes(offset) -- jmp looptop (long)
call end ifdst%ensure_storage(n)
do i = 1, case tk_lt:n_src
dst%chars(n_dst + casei) tk_le= src(i:i)
end case tk_gt:do
dst%len = case tk_ge:n
type is case tk_ne:(character(*))
n_dst = case tk_eq:dst%len
n_src = len (src, kind = gen_rec(t[2]nk)
n = n_dst + gen_rec(t[3])n_src
call integer xrmdst%ensure_storage(n)
do i = 1, n_src
if n_type=tk_ne then xrm = 0o225 -- (#95)
dst%chars(n_dst + i) elsif n_type=tk_lt then xrm = 0o234 -- src(#9Ci:i)
end do
elsif n_type=tk_ge then xrm = 0o235 -- (#9D)
dst%len = n
elsif n_type=tk_le then xrm = 0o236 -- (#9E)
class is (strbuf_t)
elsif n_type=tk_gt then xrm = 0o237 -- (#9F)
n_dst = else ?9/0dst%len
n_src = end ifsrc%len
n = n_dst + n_src
code &= { 0o061,0o300, -- xor eax,eax
call dst%ensure_storage(n)
0o132, -- pop edx
dst%chars((n_dst + 1):n) = src%chars(1:n_src)
0o131, -- pop ecx
dst%len = n
0o071,0o321, -- cmp ecx,edx
class default
0o017,xrm,0o300, -- setcc al
error stop
0o120} -- push eax
end select
case tk_add:
end subroutine strbuf_t_append
case tk_or:
 
case tk_and:
function skip_whitespace (strbuf, i) result (j)
case tk_sub:
class(strbuf_t), intent(in) :: strbuf
gen_rec(t[2])
integer(kind = nk), intent(in) :: i
gen_rec(t[3])
integer(kind = nk) :: j
integer op = find(n_type,{tk_add,tk_or,0,0,tk_and,tk_sub})
 
op = 0o001 + (op-1)*0o010
logical :: done
code &= { 0o130, -- pop eax
 
op,0o004,0o044} -- add/or/and/sub [esp],eax
j = case tk_mul:i
done = .false.
gen_rec(t[2])
do while (.not. done)
gen_rec(t[3])
if (at_end_of_line (strbuf, j)) then
code &= { 0o131, -- pop ecx
done = .true.
0o130, -- pop eax
else if (.not. isspace (strbuf%chars(j))) then
0o367,0o341, -- mul ecx
done = .true.
0o120} -- push eax
case tk_div:else
j = casej tk_mod:+ 1
end gen_rec(t[2])if
end do
gen_rec(t[3])
end function skip_whitespace
integer push = 0o120+(n_type=tk_mod)*2
 
code &= { 0o131, -- pop ecx
function skip_non_whitespace (strbuf, i) result (j)
0o130, -- pop eax
class(strbuf_t), intent(in) :: strbuf
0o231, -- cdq (eax -> edx:eax)
integer(kind = nk), intent(in) :: i
0o367,0o371, -- idiv ecx
integer(kind = nk) :: j
push} -- push eax|edx
 
case tk_Identifier:
logical :: done
integer n = var_idx(t)
 
code &= {0o377,0o065,chain,1,n,0} -- push [n]
j = i
chain = length(code)-3
done = .false.
case tk_putc:
do while (.not. done)
case tk_Printi:
if (at_end_of_line (strbuf, j)) then
case tk_Prints:
done = gen_rec(t[2]).true.
else if (isspace (strbuf%chars(j))) then
integer n = find(n_type,{tk_putc,tk_Printi,tk_Prints})
done = .true.
code &= {0o350,chain,3,n,0} -- call :printc/i/s
else
chain = length(code)-3
j = casej tk_String:+ 1
end if
integer n = string_idx(t)
end do
code &= {0o150,chain,2,n,0} -- push RawStringPtr(string)
end function skip_non_whitespace
chain = length(code)-3
 
case tk_if:
function skip_whitespace_backwards (strbuf, i) result (j)
-- emit: <condition><mainjmp><truepart>[<elsejmp><falsepart>]
class(strbuf_t), intent(in) :: strbuf
gen_rec(t[2])
integer(kind = nk), intent(in) :: i
code &= {0o130, -- pop eax
integer(kind = nk) :: j
0o205,0o300} -- test eax,eax
 
if t[3][1]!=tk_if then ?9/0 end if
logical :: done
integer truesize = gen_size(t[3][2])
 
integer falsesize = gen_size(t[3][3])
j = i
integer elsejmp = iff(falsesize=0?0:iff(falsesize>127?5:2))
done = .false.
integer offset = truesize+elsejmp
do while (.not. done)
integer mainjmp = iff(offset>127?6:2)
if (j == if mainjmp=2-1) then
done = .true.
code &= {0o164,offset} -- jz (short) else/end
else if (.not. isspace (strbuf%chars(j))) elsethen
done = .true.
code &= {0o017,0o204}&int_to_bytes(offset) -- jz (long) else/end
end ifelse
j = j - gen_rec(t[3][2])1
end if falsesize!=0 then
end do
offset = falsesize
end function skip_whitespace_backwards
if elsejmp=2 then
 
code &= 0o353&offset -- jmp end if (short)
function at_end_of_line (strbuf, i) result (bool)
else
class(strbuf_t), intent(in) :: strbuf
code &= 0o351&int_to_bytes(offset) -- jmp end if (long)
integer(kind = nk), intent(in) :: i
end if
logical :: bool
gen_rec(t[3][3])
 
end if
bool = (strbuf%length() < i)
case tk_not:
end function at_end_of_line
gen_rec(t[2])
 
code &= {0o132, -- pop edx
end module string_buffers
0o061,0o300, -- xor eax,eax
 
0o205,0o322, -- test edx,edx
module reading_one_line_from_a_stream
0o017,0o224,0o300, -- setz al
use, intrinsic :: iso_fortran_env, only: input_unit
0o120} -- push eax
use, intrinsic :: iso_fortran_env, only: error_unit
case tk_neg:
use, non_intrinsic :: compiler_type_kinds, only: nk, ck, ick
gen_rec(t[2])
use, non_intrinsic :: string_buffers
code &= {0o130, -- pop eax
 
0o367,0o330, -- neg eax
implicit none
0o120} -- push eax
private
else:
 
error("error in code generator - found %d, expecting operator\n", {n_type})
! get_line_from_stream: read an entire input line from a stream into
end switch
! a strbuf_t.
integer actsize = length(code)
public :: get_line_from_stream
if initsize+estsize!=actsize then ?"9/0" end if -- (test gen_size)
 
character(1, kind = ck), parameter :: linefeed_char = char (10, kind = ck)
 
! The following is correct for Unix and its relatives.
character(1, kind = ck), parameter :: newline_char = linefeed_char
 
contains
 
subroutine get_line_from_stream (unit_no, eof, no_newline, strbuf)
integer, intent(in) :: unit_no
logical, intent(out) :: eof ! End of file?
logical, intent(out) :: no_newline ! There is a line but it has no
! newline? (Thus eof also must
! be .true.)
class(strbuf_t), intent(inout) :: strbuf
 
character(1, kind = ck) :: ch
 
strbuf = ''
call get_ch (unit_no, eof, ch)
do while (.not. eof .and. ch /= newline_char)
call strbuf%append (ch)
call get_ch (unit_no, eof, ch)
end do
no_newline = eof .and. (strbuf%length() /= 0)
end subroutine get_line_from_stream
 
subroutine get_ch (unit_no, eof, ch)
!
! Read a single code point from the stream.
!
! Currently this procedure simply inputs ‘ASCII’ bytes rather than
! Unicode code points.
!
integer, intent(in) :: unit_no
logical, intent(out) :: eof
character(1, kind = ck), intent(out) :: ch
 
integer :: stat
character(1) :: c = '*'
 
eof = .false.
 
if (unit_no == input_unit) then
call get_input_unit_char (c, stat)
else
read (unit = unit_no, iostat = stat) c
end if
end procedure
 
if (stat < 0) then
global procedure code_gen(object t)
ch = ck_'*'
--
eof = .true.
-- Generates proper machine code.
else if (0 < stat) then
--
write (error_unit, '("Input error with status code ", I0)') stat
-- Example: i=10; print "\n"; print i; print "\n"
stop 1
-- Result in vars, strings, chain, code (declared above)
else
-- where vars is: {"i"},
-- ch = char strings(ichar is(c, {"\n"}kind = ick), kind = ck)
end if
-- code is { 0o150,#0A,#00,#00,#00, -- 1: push 10
end subroutine get_ch
-- 0o217,0o005,0,1,1,0 -- 6: pop [i]
-- 0o150,8,2,1,0, -- 12: push ("\n")
-- 0o350,13,3,3,0, -- 17: call :prints
-- 0o377,0o065,18,1,1,0, -- 22: push [i]
-- 0o350,24,3,2,0, -- 28: call :printi
-- 0o150,29,2,1,0, -- 33: push ("\n")
-- 0o350,34,3,3,0, -- 38: call :prints
-- 0o303} -- 43: ret
-- and chain is 39 (->34->29->24->18->13->8->0)
-- The chain connects all places where we need an actual address before
-- the code is executed, with the byte after the link differentiating
-- between var(1), string(2), and builtin(3), and the byte after that
-- determining the instance of the given type - not that any of them
-- are actually limited to a byte in the above intermediate form, and
-- of course the trailing 0 of each {link,type,id,0} is just there to
-- reserve the space we will need.
--
gen_rec(t)
code = append(code,0o303) -- ret (0o303=#C3)
end procedure
 
!!!
include builtins/VM/puts1.e -- low-level console i/o routines
!!! If you tell gfortran you want -std=f2008 or -std=f2018, you likely
!!! will need to add also -fall-intrinsics or -U__GFORTRAN__
!!!
!!! The first way, you get the FGETC intrinsic. The latter way, you
!!! get the C interface code that uses getchar(3).
!!!
#ifdef __GFORTRAN__
 
subroutine get_input_unit_char (c, stat)
function setbuiltins()
!
atom printc,printi,prints
! The following works if you are using gfortran.
#ilASM{
!
jmp :setbuiltins
! (FGETC is considered a feature for backwards compatibility with
::printc
! g77. However, I know of no way to reconfigure input_unit as a
lea edi,[esp+4]
! Fortran 2003 stream, for use with ordinary ‘read’.)
mov esi,1
!
call :%puts1ediesi -- (edi=raw text, esi=length)
character, intent(inout) :: c
ret 4
integer, intent(out) :: stat
::printi
mov eax,[esp+4]
push 0 -- no cr
call :%putsint -- (nb limited to +/-9,999,999,999)
ret 4
::prints
mov edi,[esp+4]
mov esi,[edi-12]
call :%puts1ediesi -- (edi=raw text, esi=length)
ret 4
::setbuiltins
mov eax,:printc
lea edi,[printc]
call :%pStoreMint
mov eax,:printi
lea edi,[printi]
call :%pStoreMint
mov eax,:prints
lea edi,[prints]
call :%pStoreMint
}
return {printc,printi,prints}
end function
 
call fgetc (input_unit, c, stat)
global constant builtin_names = {"printc","printi","prints"}
end subroutine get_input_unit_char
global constant builtins = setbuiltins()
 
#else
global atom var_mem, code_mem
 
subroutine get_input_unit_char (c, stat)
function RawStringPtr(integer n) -- (based on IupRawStringPtr from pGUI.e)
!
--
! An alternative implementation of get_input_unit_char. This
-- Returns a raw string pointer for s, somewhat like allocate_string(s), but using the existing memory.
! actually reads input from the C standard input, which might not
-- NOTE: The return is only valid as long as the value passed as the parameter remains in existence.
! be the same as input_unit.
--
!
atom res
use, intrinsic :: iso_c_binding, only: c_int
string s = strings[n]
character, intent(inout) :: c
#ilASM{
integer, intent(out) :: stat
mov eax,[s]
lea edi,[res]
shl eax,2
call :%pStoreMint
}
stringptrs[n] = res
return res
end function
 
interface
global procedure fixup()
!
var_mem = allocate(length(vars)*4)
! Use getchar(3) to read characters from standard input. This
mem_set(var_mem,0,length(vars)*4)
! assumes there is actually such a function available, and that
code_mem = allocate(length(code))
! getchar(3) does not exist solely as a macro. (One could write
poke(code_mem,code)
! one’s own getchar() if necessary, of course.)
while chain!=0 do
integer this = chain!
function getchar () result (c) bind (c, name = 'getchar')
chain = code[this]
use, intrinsic :: iso_c_binding, only: c_int
integer ftype = code[this+1]
integer id(kind = code[this+2]c_int) :: c
end switchfunction ftype dogetchar
end interface
case 1: -- vars
 
poke4(code_mem+this-1,var_mem+(id-1)*4)
integer(kind = c_int) :: i_char
case 2: -- strings
 
poke4(code_mem+this-1,RawStringPtr(id))
i_char = getchar ()
case 3: -- builtins
!
poke4(code_mem+this-1,builtins[id]-(code_mem+this+3))
! The C standard requires that EOF have a negative value. If the
end switch
! value returned by getchar(3) is not EOF, then it will be
end while
! representable as an unsigned char. Therefore, to check for end
end procedure</lang>
! of file, one need only test whether i_char is negative.
And a simple test driver for the specific task:
!
<lang Phix>--
if (i_char < 0) then
-- demo\rosetta\Compiler\cgen.exw
stat = -1
-- ==============================
else
--
stat = 0
-- Generates 32-bit machine code (see note in vm.exw)
c = char (i_char)
--
end if
end subroutine get_input_unit_char
 
#endif
 
end module reading_one_line_from_a_stream
 
module ast_reader
 
!
! The AST will be read into an array. Perhaps that will improve
! locality, compared to storing the AST as many linked heap nodes.
!
! In any case, implementing the AST this way is an interesting
! problem.
!
 
use, intrinsic :: iso_fortran_env, only: input_unit
use, intrinsic :: iso_fortran_env, only: output_unit
use, intrinsic :: iso_fortran_env, only: error_unit
use, non_intrinsic :: compiler_type_kinds, only: nk, ck, ick, rik
use, non_intrinsic :: helper_procedures, only: next_power_of_two
use, non_intrinsic :: helper_procedures, only: new_storage_size
use, non_intrinsic :: string_buffers
use, non_intrinsic :: reading_one_line_from_a_stream
 
implicit none
private
 
public :: string_table_t
public :: ast_node_t
public :: ast_t
public :: read_ast
 
integer, parameter, public :: node_Nil = 0
integer, parameter, public :: node_Identifier = 1
integer, parameter, public :: node_String = 2
integer, parameter, public :: node_Integer = 3
integer, parameter, public :: node_Sequence = 4
integer, parameter, public :: node_If = 5
integer, parameter, public :: node_Prtc = 6
integer, parameter, public :: node_Prts = 7
integer, parameter, public :: node_Prti = 8
integer, parameter, public :: node_While = 9
integer, parameter, public :: node_Assign = 10
integer, parameter, public :: node_Negate = 11
integer, parameter, public :: node_Not = 12
integer, parameter, public :: node_Multiply = 13
integer, parameter, public :: node_Divide = 14
integer, parameter, public :: node_Mod = 15
integer, parameter, public :: node_Add = 16
integer, parameter, public :: node_Subtract = 17
integer, parameter, public :: node_Less = 18
integer, parameter, public :: node_LessEqual = 19
integer, parameter, public :: node_Greater = 20
integer, parameter, public :: node_GreaterEqual = 21
integer, parameter, public :: node_Equal = 22
integer, parameter, public :: node_NotEqual = 23
integer, parameter, public :: node_And = 24
integer, parameter, public :: node_Or = 25
 
type :: string_table_element_t
character(:, kind = ck), allocatable :: str
end type string_table_element_t
 
type :: string_table_t
integer(kind = nk), private :: len = 0_nk
type(string_table_element_t), allocatable, private :: strings(:)
contains
procedure, pass, private :: ensure_storage => string_table_t_ensure_storage
procedure, pass :: look_up_index => string_table_t_look_up_index
procedure, pass :: look_up_string => string_table_t_look_up_string
procedure, pass :: length => string_table_t_length
generic :: look_up => look_up_index
generic :: look_up => look_up_string
end type string_table_t
 
type :: ast_node_t
integer :: node_variety
 
! Runtime integer, symbol index, or string index.
integer(kind = rik) :: int
 
! The left branch begins at the next node. The right branch
! begins at the address of the left branch, plus the following.
integer(kind = nk) :: right_branch_offset
end type ast_node_t
 
type :: ast_t
integer(kind = nk), private :: len = 0_nk
type(ast_node_t), allocatable, public :: nodes(:)
contains
procedure, pass, private :: ensure_storage => ast_t_ensure_storage
end type ast_t
 
contains
 
subroutine string_table_t_ensure_storage (table, length_needed)
class(string_table_t), intent(inout) :: table
integer(kind = nk), intent(in) :: length_needed
 
integer(kind = nk) :: len_needed
include cgen.e
integer(kind = nk) :: new_size
type(string_table_t) :: new_table
 
len_needed = max (length_needed, 1_nk)
function get_var_name(atom addr)
integer n = (addr-var_mem)/4+1
if n<1 or n>length(vars) then ?9/0 end if
return vars[n]
end function
 
if (.not. allocated (table%strings)) then
function hxl(integer pc, object oh, string fmt, sequence args={})
! Initialize a new table%strings array.
-- helper routine to display the octal/hex bytes just decoded,
new_size = new_storage_size (len_needed)
-- along with the code offset and the human-readable text.
allocate (table%strings(1:new_size))
if length(args) then fmt = sprintf(fmt,args) end if
else if (ubound (table%strings, 1) < len_needed) then
sequence octhex = {}
! Allocate a new table%strings array, larger than the current
atom base = code_mem+pc
! one, but containing the same strings.
integer len = 0
new_size = new_storage_size (len_needed)
if integer(oh) then -- all octal
allocate (new_table%strings(1:new_size))
for i=1 to oh do
new_table%strings(1:table%len) = table%strings(1:table%len)
octhex = append(octhex,sprintf("0o%03o",peek(base)))
call move_alloc (new_table%strings, table%strings)
base += 1
end for
len = oh
else -- some octal and some hex
for i=1 to length(oh) by 2 do
for j=1 to oh[i] do
octhex = append(octhex,sprintf("0o%03o",peek(base)))
base += 1
end for
len += oh[i]
for j=1 to oh[i+1] do
octhex = append(octhex,sprintf("#%02x",peek(base)))
base += 1
end for
len += oh[i+1]
end for
end if
end subroutine string_table_t_ensure_storage
printf(output_file,"%4d: %-30s %s\n",{pc+1,join(octhex,","),fmt})
return len
end function
 
elemental function string_table_t_length (table) result (len)
constant cccodes = {"o?" ,"no?","b?" ,"ae?","z" ,"ne" ,"be?","a?",
class(string_table_t), intent(in) :: table
-- 0 , 1 , 2 , 3 , 4 , 5 , 6 , 7 ,
integer(kind = nk) :: len
"s?" ,"ns?","pe?","po?","l" ,"ge" ,"le" ,"g" }
-- 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15
 
len = table%len
constant regs = {"eax","ecx","edx"} -- (others as/when needed)
end function string_table_t_length
 
function string_table_t_look_up_index (table, str) result (index)
procedure decode()
class(string_table_t), intent(inout) :: table
-- for a much more complete (and better organised) disassembler, see p2asm.e
character(*, kind = ck), intent(in) :: str
integer pc = 0, -- nb 0-based
integer(kind = rik) :: opcode, xrmindex
 
!
while pc<length(code) do
! This implementation simply stores the strings sequentially into
opcode = peek(code_mem+pc)
! an array. Obviously, for large numbers of strings, one might
xrm = -1
! wish to do switchsomething opcodemore docomplex.
!
case 0o150:
! Standard Fortran does not come, out of the box, with a massive
atom vaddr = peek4s(code_mem+pc+1)
! runtime library for doing such things. They are, however, no
integer n = find(vaddr,stringptrs)
! longer nearly as challenging to implement in Fortran as they
object arg = iff(n?enquote(strings[n])
! used to be.
:sprintf("%d",vaddr))
!
pc += hxl(pc,{1,4},"push %s",{arg})
 
case 0o217:
integer(kind = nk) :: i
case 0o377:
 
integer n = find(opcode,{0o217,0o377})
i = 1
string op = {"pop","push"}[n]
index = 0
xrm = peek(code_mem+pc+1)
do while (index == 0)
if n!=find(xrm,{0o005,0o065}) then exit end if
if (i == table%len + 1) then
atom addr = peek4u(code_mem+pc+2)
! The string is new and pcmust +=be hxl(pc,{2,4},"popadded [%s]",{get_var_name(addr)})to the table.
i = casetable%len 0o061:+ 1
if (huge case(1_rik) 0o071:< i) then
! String indices are assumed to be storable as runtime
case 0o205:
! integer n = find(opcode,{0o061,0o071,0o205})integers.
write (error_unit, '("string_table_t stringcapacity op = {"xor","cmp","testexceeded"}[n])')
stop xrm = peek(code_mem+pc+1)
if and_bits(xrm,0o300)!=0o300 then exit end if
call table%ensure_storage(i)
string r1 = regs[and_bits(xrm,0o070)/0o010+1]
string r2table%len = regs[and_bits(xrm,0o007)+1]i
allocate (table%strings(i)%str, source = str)
pc += hxl(pc,2,"%s %s,%s",{op,r1,r2})
index = caseint 0o017:(i, kind = rik)
else if xrm(table%strings(i)%str == peek(code_mem+pc+1str) then
index = int (i, kind = switch xrm dorik)
case 0o224:else
i = i + case 0o225:1
end case 0o234:if
end do
case 0o235:
end function string_table_t_look_up_index
case 0o236:
 
case 0o237:
function string_table_t_look_up_string (table, index) result (str)
string cc = cccodes[and_bits(xrm,0o017)+1]
class(string_table_t), intent(inout) :: table
if peek(code_mem+pc+2)=0o300 then
integer(kind = rik), intent(in) :: index
pc += hxl(pc,3,"set%s al",{cc})
character(:, kind = ck), allocatable :: str
else
 
exit
!
end if
! This is the reverse of string_table_t_look_up_index: given an
case 0o204:
! index, find the string.
integer offset = peek4s(code_mem+pc+2)
!
pc += hxl(pc,{2,4},"jz %d",{pc+6+offset+1})
 
else
if (index < 1 .or. table%len < index) exitthen
! In correct code, this branch should never be end switchreached.
error case 0o120:stop
else
case 0o122:
allocate (str, source = table%strings(index)%str)
case 0o130:
case 0o131:
case 0o132:
string op = {"push","pop"}[find(and_bits(opcode,0o070),{0o020,0o030})]
string reg = regs[and_bits(opcode,0o007)+1]
pc += hxl(pc,1,"%s %s",{op,reg})
case 0o231:
pc += hxl(pc,1,"cdq")
case 0o164:
case 0o353:
string jop = iff(opcode=0o164?"jz":"jmp")
integer offset = peek1s(code_mem+pc+1)
pc += hxl(pc,{1,1},"%s %d",{jop,pc+2+offset+1})
case 0o351:
integer offset = peek4s(code_mem+pc+1)
pc += hxl(pc,{1,4},"jmp %d",{pc+5+offset+1})
case 0o303:
pc += hxl(pc,1,"ret")
case 0o350:
integer offset = peek4s(code_mem+pc+1)
atom addr = offset+code_mem+pc+5
integer n = find(addr,builtins)
pc += hxl(pc,{1,4},"call :%s",{builtin_names[n]})
case 0o001:
case 0o041:
case 0o051:
integer n = find(opcode,{0o001,0o041,0o051})
string op = {"add","and","sub"}[n]
xrm = peek(code_mem+pc+1)
switch xrm do
case 0o004:
if peek(code_mem+pc+2)=0o044 then
pc += hxl(pc,3,"%s [esp],eax",{op})
else
exit
end if
else
exit
end switch
case 0o367:
xrm = peek(code_mem+pc+1)
if and_bits(xrm,0o300)!=0o300 then exit end if
integer n = find(and_bits(xrm,0o070),{0o030,0o040,0o070})
if n=0 then exit end if
string op = {"neg","mul","idiv"}[n]
string reg = regs[and_bits(xrm,0o007)+1]
pc += hxl(pc,2,"%s %s",{op,reg})
else
exit
end switch
end while
if pc<length(code) then
?"incomplete:"
if xrm=-1 then
?{pc+1,sprintf("0o%03o",opcode)}
else
?{pc+1,sprintf("0o%03o 0o%03o",{opcode,xrm})}
end if
end if
end function string_table_t_look_up_string
end procedure
 
subroutine ast_t_ensure_storage (ast, length_needed)
procedure main(sequence cl)
class(ast_t), intent(inout) :: ast
open_files(cl)
integer(kind = nk), intent(in) :: length_needed
toks = lex()
object t = parse()
code_gen(t)
fixup()
decode()
free({var_mem,code_mem})
close_files()
end procedure
 
integer(kind = nk) :: len_needed
--main(command_line())
integer(kind = nk) :: new_size
main({0,0,"gcd.c"})</lang>
type(ast_t) :: new_ast
 
len_needed = max (length_needed, 1_nk)
 
if (.not. allocated (ast%nodes)) then
! Initialize a new ast%nodes array.
new_size = new_storage_size (len_needed)
allocate (ast%nodes(1:new_size))
else if (ubound (ast%nodes, 1) < len_needed) then
! Allocate a new ast%nodes array, larger than the current one,
! but containing the same nodes.
new_size = new_storage_size (len_needed)
allocate (new_ast%nodes(1:new_size))
new_ast%nodes(1:ast%len) = ast%nodes(1:ast%len)
call move_alloc (new_ast%nodes, ast%nodes)
end if
end subroutine ast_t_ensure_storage
 
subroutine read_ast (unit_no, strbuf, ast, symtab, strtab)
integer, intent(in) :: unit_no
type(strbuf_t), intent(inout) :: strbuf
type(ast_t), intent(inout) :: ast
type(string_table_t), intent(inout) :: symtab
type(string_table_t), intent(inout) :: strtab
 
logical :: eof
logical :: no_newline
integer(kind = nk) :: after_ast_address
ast%len = 0
symtab%len = 0
strtab%len = 0
call build_subtree (1_nk, after_ast_address)
 
contains
 
recursive subroutine build_subtree (here_address, after_subtree_address)
integer(kind = nk), value :: here_address
integer(kind = nk), intent(out) :: after_subtree_address
 
integer :: node_variety
integer(kind = nk) :: i, j
integer(kind = nk) :: left_branch_address
integer(kind = nk) :: right_branch_address
 
! Get a line from the parser output.
call get_line_from_stream (unit_no, eof, no_newline, strbuf)
 
if (eof) then
call ast_error
else
! Prepare to store a new node.
call ast%ensure_storage(here_address)
ast%len = here_address
 
! What sort of node is it?
i = skip_whitespace (strbuf, 1_nk)
j = skip_non_whitespace (strbuf, i)
node_variety = strbuf_to_node_variety (strbuf, i, j - 1)
 
ast%nodes(here_address)%node_variety = node_variety
 
select case (node_variety)
case (node_Nil)
after_subtree_address = here_address + 1
case (node_Identifier)
i = skip_whitespace (strbuf, j)
j = skip_non_whitespace (strbuf, i)
ast%nodes(here_address)%int = &
& strbuf_to_symbol_index (strbuf, i, j - 1, symtab)
after_subtree_address = here_address + 1
case (node_String)
i = skip_whitespace (strbuf, j)
j = skip_whitespace_backwards (strbuf, strbuf%length())
ast%nodes(here_address)%int = &
& strbuf_to_string_index (strbuf, i, j, strtab)
after_subtree_address = here_address + 1
case (node_Integer)
i = skip_whitespace (strbuf, j)
j = skip_non_whitespace (strbuf, i)
ast%nodes(here_address)%int = strbuf_to_int (strbuf, i, j - 1)
after_subtree_address = here_address + 1
case default
! The node is internal, and has left and right branches.
! The left branch will start at left_branch_address; the
! right branch will start at left_branch_address +
! right_side_offset.
left_branch_address = here_address + 1
! Build the left branch.
call build_subtree (left_branch_address, right_branch_address)
! Build the right_branch.
call build_subtree (right_branch_address, after_subtree_address)
ast%nodes(here_address)%right_branch_offset = &
& right_branch_address - left_branch_address
end select
 
end if
end subroutine build_subtree
end subroutine read_ast
 
function strbuf_to_node_variety (strbuf, i, j) result (node_variety)
class(strbuf_t), intent(in) :: strbuf
integer(kind = nk), intent(in) :: i, j
integer :: node_variety
 
!
! This function has not been optimized in any way, unless the
! Fortran compiler can optimize it.
!
! Something like a ‘radix tree search’ could be done on the
! characters of the strbuf. Or a perfect hash function. Or a
! binary search. Etc.
!
 
if (j == i - 1) then
call ast_error
else
select case (strbuf%to_unicode(i, j))
case (ck_";")
node_variety = node_Nil
case (ck_"Identifier")
node_variety = node_Identifier
case (ck_"String")
node_variety = node_String
case (ck_"Integer")
node_variety = node_Integer
case (ck_"Sequence")
node_variety = node_Sequence
case (ck_"If")
node_variety = node_If
case (ck_"Prtc")
node_variety = node_Prtc
case (ck_"Prts")
node_variety = node_Prts
case (ck_"Prti")
node_variety = node_Prti
case (ck_"While")
node_variety = node_While
case (ck_"Assign")
node_variety = node_Assign
case (ck_"Negate")
node_variety = node_Negate
case (ck_"Not")
node_variety = node_Not
case (ck_"Multiply")
node_variety = node_Multiply
case (ck_"Divide")
node_variety = node_Divide
case (ck_"Mod")
node_variety = node_Mod
case (ck_"Add")
node_variety = node_Add
case (ck_"Subtract")
node_variety = node_Subtract
case (ck_"Less")
node_variety = node_Less
case (ck_"LessEqual")
node_variety = node_LessEqual
case (ck_"Greater")
node_variety = node_Greater
case (ck_"GreaterEqual")
node_variety = node_GreaterEqual
case (ck_"Equal")
node_variety = node_Equal
case (ck_"NotEqual")
node_variety = node_NotEqual
case (ck_"And")
node_variety = node_And
case (ck_"Or")
node_variety = node_Or
case default
call ast_error
end select
end if
end function strbuf_to_node_variety
 
function strbuf_to_symbol_index (strbuf, i, j, symtab) result (int)
class(strbuf_t), intent(in) :: strbuf
integer(kind = nk), intent(in) :: i, j
type(string_table_t), intent(inout) :: symtab
integer(kind = rik) :: int
 
if (j == i - 1) then
call ast_error
else
int = symtab%look_up(strbuf%to_unicode (i, j))
end if
end function strbuf_to_symbol_index
 
function strbuf_to_int (strbuf, i, j) result (int)
class(strbuf_t), intent(in) :: strbuf
integer(kind = nk), intent(in) :: i, j
integer(kind = rik) :: int
 
integer :: stat
character(:, kind = ck), allocatable :: str
 
if (j < i) then
call ast_error
else
allocate (character(len = (j - i) + 1_nk, kind = ck) :: str)
str = strbuf%to_unicode (i, j)
read (str, *, iostat = stat) int
if (stat /= 0) then
call ast_error
end if
end if
end function strbuf_to_int
 
function strbuf_to_string_index (strbuf, i, j, strtab) result (int)
class(strbuf_t), intent(in) :: strbuf
integer(kind = nk), intent(in) :: i, j
type(string_table_t), intent(inout) :: strtab
integer(kind = rik) :: int
 
if (j == i - 1) then
call ast_error
else
int = strtab%look_up(strbuf_to_string (strbuf, i, j))
end if
end function strbuf_to_string_index
 
function strbuf_to_string (strbuf, i, j) result (str)
class(strbuf_t), intent(in) :: strbuf
integer(kind = nk), intent(in) :: i, j
character(:, kind = ck), allocatable :: str
 
character(1, kind = ck), parameter :: linefeed_char = char (10, kind = ck)
character(1, kind = ck), parameter :: backslash_char = char (92, kind = ck)
 
! The following is correct for Unix and its relatives.
character(1, kind = ck), parameter :: newline_char = linefeed_char
 
integer(kind = nk) :: k
integer(kind = nk) :: count
 
if (strbuf%chars(i) /= ck_'"' .or. strbuf%chars(j) /= ck_'"') then
call ast_error
else
! Count how many characters are needed.
count = 0
k = i + 1
do while (k < j)
count = count + 1
if (strbuf%chars(k) == backslash_char) then
k = k + 2
else
k = k + 1
end if
end do
 
allocate (character(len = count, kind = ck) :: str)
 
count = 0
k = i + 1
do while (k < j)
if (strbuf%chars(k) == backslash_char) then
if (k == j - 1) then
call ast_error
else
select case (strbuf%chars(k + 1))
case (ck_'n')
count = count + 1
str(count:count) = newline_char
case (backslash_char)
count = count + 1
str(count:count) = backslash_char
case default
call ast_error
end select
k = k + 2
end if
else
count = count + 1
str(count:count) = strbuf%chars(k)
k = k + 1
end if
end do
end if
end function strbuf_to_string
 
subroutine ast_error
!
! It might be desirable to give more detail.
!
write (error_unit, '("The AST input seems corrupted.")')
stop 1
end subroutine ast_error
 
end module ast_reader
 
module code_generation
 
!
! First we generate code as if the virtual machine itself were part
! of this program. Then we disassemble the generated code.
!
! Because we are targeting only the one output language, this seems
! an easy way to perform the task.
!
!
! A point worth noting: the virtual machine is a stack
! architecture.
!
! Stack architectures have a long history. Burroughs famously
! preferred stack architectures for running Algol programs. See, for
! instance,
! https://en.wikipedia.org/w/index.php?title=Burroughs_large_systems&oldid=1068076420
!
 
use, intrinsic :: iso_fortran_env, only: input_unit
use, intrinsic :: iso_fortran_env, only: output_unit
use, intrinsic :: iso_fortran_env, only: error_unit
use, non_intrinsic :: compiler_type_kinds
use, non_intrinsic :: helper_procedures
use, non_intrinsic :: ast_reader
 
implicit none
private
 
public :: generate_and_output_code
public :: generate_code
public :: output_code
 
! The virtual machine cannot handle integers of more than 32 bits,
! two’s-complement.
integer(kind = rik), parameter :: vm_huge_negint = -(2_rik ** 31_rik)
integer(kind = rik), parameter :: vm_huge_posint = (2_rik ** 31_rik) - 1_rik
 
! Arbitrarily chosen opcodes.
integer, parameter :: opcode_nop = 0 ! I think there should be a nop
! opcode, to reserve space for
! later hand-patching. :)
integer, parameter :: opcode_halt = 1 ! Does the ‘halt’ instruction
! apply brakes to the drum?
integer, parameter :: opcode_add = 2
integer, parameter :: opcode_sub = 3
integer, parameter :: opcode_mul = 4
integer, parameter :: opcode_div = 5
integer, parameter :: opcode_mod = 6
integer, parameter :: opcode_lt = 7
integer, parameter :: opcode_gt = 8
integer, parameter :: opcode_le = 9
integer, parameter :: opcode_ge = 10
integer, parameter :: opcode_eq = 11
integer, parameter :: opcode_ne = 12
integer, parameter :: opcode_and = 13
integer, parameter :: opcode_or = 14
integer, parameter :: opcode_neg = 15
integer, parameter :: opcode_not = 16
integer, parameter :: opcode_prtc = 17
integer, parameter :: opcode_prti = 18
integer, parameter :: opcode_prts = 19
integer, parameter :: opcode_fetch = 20
integer, parameter :: opcode_store = 21
integer, parameter :: opcode_push = 22
integer, parameter :: opcode_jmp = 23
integer, parameter :: opcode_jz = 24
 
character(8, kind = ck), parameter :: opcode_names(0:24) = &
& (/ "nop ", &
& "halt ", &
& "add ", &
& "sub ", &
& "mul ", &
& "div ", &
& "mod ", &
& "lt ", &
& "gt ", &
& "le ", &
& "ge ", &
& "eq ", &
& "ne ", &
& "and ", &
& "or ", &
& "neg ", &
& "not ", &
& "prtc ", &
& "prti ", &
& "prts ", &
& "fetch ", &
& "store ", &
& "push ", &
& "jmp ", &
& "jz " /)
 
type :: vm_code_t
integer(kind = rik), private :: len = 0_rik
character(1), allocatable :: bytes(:)
contains
procedure, pass, private :: ensure_storage => vm_code_t_ensure_storage
procedure, pass :: length => vm_code_t_length
end type vm_code_t
 
contains
 
subroutine vm_code_t_ensure_storage (code, length_needed)
class(vm_code_t), intent(inout) :: code
integer(kind = nk), intent(in) :: length_needed
 
integer(kind = nk) :: len_needed
integer(kind = nk) :: new_size
type(vm_code_t) :: new_code
 
len_needed = max (length_needed, 1_nk)
 
if (.not. allocated (code%bytes)) then
! Initialize a new code%bytes array.
new_size = new_storage_size (len_needed)
allocate (code%bytes(0:(new_size - 1)))
else if (ubound (code%bytes, 1) < len_needed - 1) then
! Allocate a new code%bytes array, larger than the current one,
! but containing the same bytes.
new_size = new_storage_size (len_needed)
allocate (new_code%bytes(0:(new_size - 1)))
new_code%bytes(0:(code%len - 1)) = code%bytes(0:(code%len - 1))
call move_alloc (new_code%bytes, code%bytes)
end if
end subroutine vm_code_t_ensure_storage
 
elemental function vm_code_t_length (code) result (len)
class(vm_code_t), intent(in) :: code
integer(kind = rik) :: len
 
len = code%len
end function vm_code_t_length
 
subroutine generate_and_output_code (outp, ast, symtab, strtab)
integer, intent(in) :: outp ! The unit to write the output to.
type(ast_t), intent(in) :: ast
type(string_table_t), intent(inout) :: symtab
type(string_table_t), intent(inout) :: strtab
 
type(vm_code_t) :: code
integer(kind = rik) :: i_vm
 
code%len = 0
i_vm = 0_rik
call generate_code (ast, 1_nk, i_vm, code)
call output_code (outp, symtab, strtab, code)
end subroutine generate_and_output_code
 
subroutine generate_code (ast, i_ast, i_vm, code)
type(ast_t), intent(in) :: ast
integer(kind = nk), intent(in) :: i_ast ! Index in the ast array.
integer(kind = rik), intent(inout) :: i_vm ! Address in the virtual machine.
type(vm_code_t), intent(inout) :: code
 
call traverse (i_ast)
 
! Generate a halt instruction.
call code%ensure_storage(i_vm + 1)
code%bytes(i_vm) = achar (opcode_halt)
i_vm = i_vm + 1
 
code%len = i_vm
 
contains
 
recursive subroutine traverse (i_ast)
integer(kind = nk), intent(in) :: i_ast ! Index in the ast array.
 
select case (ast%nodes(i_ast)%node_variety)
 
case (node_Nil)
continue
 
case (node_Integer)
block
integer(kind = rik) :: int_value
 
int_value = ast%nodes(i_ast)%int
call ensure_integer_is_vm_compatible (int_value)
call code%ensure_storage(i_vm + 5)
code%bytes(i_vm) = achar (opcode_push)
call int32_to_vm_bytes (int_value, code%bytes, i_vm + 1)
i_vm = i_vm + 5
end block
 
case (node_Identifier)
block
integer(kind = rik) :: variable_index
 
! In the best Fortran tradition, we indexed the variables
! starting at one; however, the virtual machine starts them
! at zero. So subtract 1.
variable_index = ast%nodes(i_ast)%int - 1
 
call ensure_integer_is_vm_compatible (variable_index)
call code%ensure_storage(i_vm + 5)
code%bytes(i_vm) = achar (opcode_fetch)
call uint32_to_vm_bytes (variable_index, code%bytes, i_vm + 1)
i_vm = i_vm + 5
end block
 
case (node_String)
block
integer(kind = rik) :: string_index
 
! In the best Fortran tradition, we indexed the strings
! starting at one; however, the virtual machine starts them
! at zero. So subtract 1.
string_index = ast%nodes(i_ast)%int - 1
 
call ensure_integer_is_vm_compatible (string_index)
call code%ensure_storage(i_vm + 5)
code%bytes(i_vm) = achar (opcode_push)
call uint32_to_vm_bytes (string_index, code%bytes, i_vm + 1)
i_vm = i_vm + 5
end block
 
case (node_Assign)
block
integer(kind = nk) :: i_left, i_right
integer(kind = rik) :: variable_index
 
i_left = left_branch (i_ast)
i_right = right_branch (i_ast)
 
! In the best Fortran tradition, we indexed the variables
! starting at one; however, the virtual machine starts them
! at zero. So subtract 1.
variable_index = ast%nodes(i_left)%int - 1
 
! Create code to push the right side onto the stack
call traverse (i_right)
 
! Create code to store that result into the variable on the
! left side.
call ensure_node_variety (node_Identifier, ast%nodes(i_left)%node_variety)
call ensure_integer_is_vm_compatible (variable_index)
call code%ensure_storage(i_vm + 5)
code%bytes(i_vm) = achar (opcode_store)
call uint32_to_vm_bytes (variable_index, code%bytes, i_vm + 1)
i_vm = i_vm + 5
end block
 
case (node_Multiply)
call traverse (left_branch (i_ast))
call traverse (right_branch (i_ast))
call code%ensure_storage(i_vm + 1)
code%bytes(i_vm) = achar (opcode_mul)
i_vm = i_vm + 1
 
case (node_Divide)
call traverse (left_branch (i_ast))
call traverse (right_branch (i_ast))
call code%ensure_storage(i_vm + 1)
code%bytes(i_vm) = achar (opcode_div)
i_vm = i_vm + 1
 
case (node_Mod)
call traverse (left_branch (i_ast))
call traverse (right_branch (i_ast))
call code%ensure_storage(i_vm + 1)
code%bytes(i_vm) = achar (opcode_mod)
i_vm = i_vm + 1
 
case (node_Add)
call traverse (left_branch (i_ast))
call traverse (right_branch (i_ast))
call code%ensure_storage(i_vm + 1)
code%bytes(i_vm) = achar (opcode_add)
i_vm = i_vm + 1
 
case (node_Subtract)
call traverse (left_branch (i_ast))
call traverse (right_branch (i_ast))
call code%ensure_storage(i_vm + 1)
code%bytes(i_vm) = achar (opcode_sub)
i_vm = i_vm + 1
 
case (node_Less)
call traverse (left_branch (i_ast))
call traverse (right_branch (i_ast))
call code%ensure_storage(i_vm + 1)
code%bytes(i_vm) = achar (opcode_lt)
i_vm = i_vm + 1
 
case (node_LessEqual)
call traverse (left_branch (i_ast))
call traverse (right_branch (i_ast))
call code%ensure_storage(i_vm + 1)
code%bytes(i_vm) = achar (opcode_le)
i_vm = i_vm + 1
 
case (node_Greater)
call traverse (left_branch (i_ast))
call traverse (right_branch (i_ast))
call code%ensure_storage(i_vm + 1)
code%bytes(i_vm) = achar (opcode_gt)
i_vm = i_vm + 1
 
case (node_GreaterEqual)
call traverse (left_branch (i_ast))
call traverse (right_branch (i_ast))
call code%ensure_storage(i_vm + 1)
code%bytes(i_vm) = achar (opcode_ge)
i_vm = i_vm + 1
 
case (node_Equal)
call traverse (left_branch (i_ast))
call traverse (right_branch (i_ast))
call code%ensure_storage(i_vm + 1)
code%bytes(i_vm) = achar (opcode_eq)
i_vm = i_vm + 1
 
case (node_NotEqual)
call traverse (left_branch (i_ast))
call traverse (right_branch (i_ast))
call code%ensure_storage(i_vm + 1)
code%bytes(i_vm) = achar (opcode_ne)
i_vm = i_vm + 1
 
case (node_Negate)
call ensure_node_variety (node_Nil, &
& ast%nodes(right_branch (i_ast))%node_variety)
call traverse (left_branch (i_ast))
call code%ensure_storage(i_vm + 1)
code%bytes(i_vm) = achar (opcode_neg)
i_vm = i_vm + 1
 
case (node_Not)
call ensure_node_variety (node_Nil, &
& ast%nodes(right_branch (i_ast))%node_variety)
call traverse (left_branch (i_ast))
call code%ensure_storage(i_vm + 1)
code%bytes(i_vm) = achar (opcode_not)
i_vm = i_vm + 1
 
case (node_And)
!
! This is not a short-circuiting AND and so differs from
! C. One would not notice the difference, except in side
! effects that (I believe) are not possible in our tiny
! language.
!
! Even in a language such as Fortran that has actual AND and
! OR operators, an optimizer may generate short-circuiting
! code and so spoil one’s expectations for side
! effects. (Therefore gfortran may issue a warning if you
! call an unpure function within an .AND. or
! .OR. expression.)
!
! A C equivalent to what we have our code generator doing
! (and to Fortran’s .AND. operator) might be something like
!
! #define AND(a, b) ((!!(a)) * (!!(b)))
!
! This macro takes advantage of the equivalence of AND to
! multiplication modulo 2. The ‘!!’ notations are a C idiom
! for converting values to 0 and 1.
!
call traverse (left_branch (i_ast))
call traverse (right_branch (i_ast))
call code%ensure_storage(i_vm + 1)
code%bytes(i_vm) = achar (opcode_and)
i_vm = i_vm + 1
 
case (node_Or)
!
! This is not a short-circuiting OR and so differs from
! C. One would not notice the difference, except in side
! effects that (I believe) are not possible in our tiny
! language.
!
! Even in a language such as Fortran that has actual AND and
! OR operators, an optimizer may generate short-circuiting
! code and so spoil one’s expectations for side
! effects. (Therefore gfortran may issue a warning if you
! call an unpure function within an .AND. or
! .OR. expression.)
!
! A C equivalent to what we have our code generator doing
! (and to Fortran’s .OR. operator) might be something like
!
! #define OR(a, b) (!( (!(a)) * (!(b)) ))
!
! This macro takes advantage of the equivalence of AND to
! multiplication modulo 2, and the equivalence of OR(a,b) to
! !AND(!a,!b). One could instead take advantage of the
! equivalence of OR to addition modulo 2:
!
! #define OR(a, b) ( ( (!!(a)) + (!!(b)) ) & 1 )
!
call traverse (left_branch (i_ast))
call traverse (right_branch (i_ast))
call code%ensure_storage(i_vm + 1)
code%bytes(i_vm) = achar (opcode_or)
i_vm = i_vm + 1
 
case (node_If)
block
integer(kind = nk) :: i_left, i_right
integer(kind = nk) :: i_right_then_left, i_right_then_right
logical :: there_is_an_else_clause
integer(kind = rik) :: fixup_address1
integer(kind = rik) :: fixup_address2
integer(kind = rik) :: relative_address
 
i_left = left_branch (i_ast)
i_right = right_branch (i_ast)
 
call ensure_node_variety (node_If, ast%nodes(i_right)%node_variety)
 
i_right_then_left = left_branch (i_right)
i_right_then_right = right_branch (i_right)
 
there_is_an_else_clause = &
& (ast%nodes(i_right_then_right)%node_variety /= node_Nil)
 
! Generate code for the predicate.
call traverse (i_left)
 
! Generate a conditional jump over the predicate-true code.
call code%ensure_storage(i_vm + 5)
code%bytes(i_vm) = achar (opcode_jz)
call int32_to_vm_bytes (0_rik, code%bytes, i_vm + 1)
fixup_address1 = i_vm + 1
i_vm = i_vm + 5
 
! Generate the predicate-true code.
call traverse (i_right_then_left)
 
if (there_is_an_else_clause) then
! Generate an unconditional jump over the predicate-true
! code.
call code%ensure_storage(i_vm + 5)
code%bytes(i_vm) = achar (opcode_jmp)
call int32_to_vm_bytes (0_rik, code%bytes, i_vm + 1)
fixup_address2 = i_vm + 1
i_vm = i_vm + 5
 
! Fix up the conditional jump, so it jumps to the
! predicate-false code.
relative_address = i_vm - fixup_address1
call int32_to_vm_bytes (relative_address, code%bytes, fixup_address1)
 
! Generate the predicate-false code.
call traverse (i_right_then_right)
 
! Fix up the unconditional jump, so it jumps past the
! predicate-false code.
relative_address = i_vm - fixup_address2
call int32_to_vm_bytes (relative_address, code%bytes, fixup_address2)
else
! Fix up the conditional jump, so it jumps past the
! predicate-true code.
relative_address = i_vm - fixup_address1
call int32_to_vm_bytes (relative_address, code%bytes, fixup_address1)
end if
end block
 
case (node_While)
block
 
!
! Note there is another common way to translate a
! while-loop which is to put (logically inverted) predicate
! code *after* the loop-body code, followed by a
! conditional jump to the start of the loop. You start the
! loop by unconditionally jumping to the predicate code.
!
! If our VM had a ‘jnz’ instruction, that translation would
! almost certainly be slightly better than this one. Given
! that we do not have a ‘jnz’, the code would end up
! slightly enlarged; one would have to put ‘not’ before the
! ‘jz’ at the bottom of the loop.
!
 
integer(kind = nk) :: i_left, i_right
integer(kind = rik) :: loop_address
integer(kind = rik) :: fixup_address
integer(kind = rik) :: relative_address
 
i_left = left_branch (i_ast)
i_right = right_branch (i_ast)
 
! Generate code for the predicate.
loop_address = i_vm
call traverse (i_left)
 
! Generate a conditional jump out of the loop.
call code%ensure_storage(i_vm + 5)
code%bytes(i_vm) = achar (opcode_jz)
call int32_to_vm_bytes (0_rik, code%bytes, i_vm + 1)
fixup_address = i_vm + 1
i_vm = i_vm + 5
 
! Generate code for the loop body.
call traverse (i_right)
 
! Generate an unconditional jump to the top of the loop.
call code%ensure_storage(i_vm + 5)
code%bytes(i_vm) = achar (opcode_jmp)
relative_address = loop_address - (i_vm + 1)
call int32_to_vm_bytes (relative_address, code%bytes, i_vm + 1)
i_vm = i_vm + 5
 
! Fix up the conditional jump, so it jumps after the loop
! body.
relative_address = i_vm - fixup_address
call int32_to_vm_bytes (relative_address, code%bytes, fixup_address)
end block
 
case (node_Prtc)
call ensure_node_variety (node_Nil, &
& ast%nodes(right_branch (i_ast))%node_variety)
call traverse (left_branch (i_ast))
call code%ensure_storage(i_vm + 1)
code%bytes(i_vm) = achar (opcode_prtc)
i_vm = i_vm + 1
 
case (node_Prti)
call ensure_node_variety (node_Nil, &
& ast%nodes(right_branch (i_ast))%node_variety)
call traverse (left_branch (i_ast))
call code%ensure_storage(i_vm + 1)
code%bytes(i_vm) = achar (opcode_prti)
i_vm = i_vm + 1
 
case (node_Prts)
call ensure_node_variety (node_Nil, &
& ast%nodes(right_branch (i_ast))%node_variety)
call traverse (left_branch (i_ast))
call code%ensure_storage(i_vm + 1)
code%bytes(i_vm) = achar (opcode_prts)
i_vm = i_vm + 1
 
case (node_Sequence)
call traverse (left_branch (i_ast))
call traverse (right_branch (i_ast))
 
case default
call bad_ast
 
end select
 
code%len = i_vm
 
end subroutine traverse
 
elemental function left_branch (i_here) result (i_left)
integer(kind = nk), intent(in) :: i_here
integer(kind = nk) :: i_left
 
i_left = i_here + 1
end function left_branch
 
elemental function right_branch (i_here) result (i_right)
integer(kind = nk), intent(in) :: i_here
integer(kind = nk) :: i_right
 
i_right = i_here + 1 + ast%nodes(i_here)%right_branch_offset
end function right_branch
 
subroutine ensure_node_variety (expected_node_variety, found_node_variety)
integer, intent(in) :: expected_node_variety
integer, intent(in) :: found_node_variety
if (expected_node_variety /= found_node_variety) call bad_ast
end subroutine ensure_node_variety
 
subroutine bad_ast
call codegen_error_message
write (error_unit, '("unexpected abstract syntax")')
stop 1
end subroutine bad_ast
 
end subroutine generate_code
 
subroutine output_code (outp, symtab, strtab, code)
integer, intent(in) :: outp ! The unit to write the output to.
type(string_table_t), intent(inout) :: symtab
type(string_table_t), intent(inout) :: strtab
type(vm_code_t), intent(in) :: code
 
call write_header (outp, symtab%length(), strtab%length())
call write_strings (outp, strtab)
call disassemble_instructions (outp, code)
end subroutine output_code
 
subroutine write_header (outp, data_size, strings_size)
integer, intent(in) :: outp
integer(kind = rik) :: data_size
integer(kind = rik) :: strings_size
 
call ensure_integer_is_vm_compatible (data_size)
call ensure_integer_is_vm_compatible (strings_size)
write (outp, '("Datasize: ", I0, " Strings: ", I0)') data_size, strings_size
end subroutine write_header
 
subroutine write_strings (outp, strtab)
integer, intent(in) :: outp
type(string_table_t), intent(inout) :: strtab
 
integer(kind = rik) :: i
 
do i = 1_rik, strtab%length()
write (outp, '(1A)') quoted_string (strtab%look_up(i))
end do
end subroutine write_strings
 
subroutine disassemble_instructions (outp, code)
integer, intent(in) :: outp
type(vm_code_t), intent(in) :: code
 
integer(kind = rik) :: i_vm
integer :: opcode
integer(kind = rik) :: n
 
i_vm = 0_rik
do while (i_vm /= code%length())
call write_vm_code_address (outp, i_vm)
opcode = iachar (code%bytes(i_vm))
call write_vm_opcode (outp, opcode)
select case (opcode)
case (opcode_push)
call int32_from_vm_bytes (n, code%bytes, i_vm + 1)
call write_vm_int_literal (outp, n)
i_vm = i_vm + 5
case (opcode_fetch, opcode_store)
call uint32_from_vm_bytes (n, code%bytes, i_vm + 1)
call write_vm_data_address (outp, n)
i_vm = i_vm + 5
case (opcode_jmp, opcode_jz)
call int32_from_vm_bytes (n, code%bytes, i_vm + 1)
call write_vm_jump_address (outp, n, i_vm + 1)
i_vm = i_vm + 5
case default
i_vm = i_vm + 1
end select
write (outp, '()', advance = 'yes')
end do
end subroutine disassemble_instructions
 
subroutine write_vm_code_address (outp, i_vm)
integer, intent(in) :: outp
integer(kind = rik), intent(in) :: i_vm
 
! 10 characters is wide enough for any 32-bit unsigned number.
write (outp, '(I10, 1X)', advance = 'no') i_vm
end subroutine write_vm_code_address
 
subroutine write_vm_opcode (outp, opcode)
integer, intent(in) :: outp
integer, intent(in) :: opcode
 
character(8, kind = ck) :: opcode_name
 
opcode_name = opcode_names(opcode)
 
select case (opcode)
case (opcode_push, opcode_fetch, opcode_store, opcode_jz, opcode_jmp)
write (outp, '(1A)', advance = 'no') opcode_name(1:6)
case default
write (outp, '(1A)', advance = 'no') trim (opcode_name)
end select
end subroutine write_vm_opcode
 
subroutine write_vm_int_literal (outp, n)
integer, intent(in) :: outp
integer(kind = rik), intent(in) :: n
 
write (outp, '(I0)', advance = 'no') n
end subroutine write_vm_int_literal
 
subroutine write_vm_data_address (outp, i)
integer, intent(in) :: outp
integer(kind = rik), intent(in) :: i
 
write (outp, '("[", I0, "]")', advance = 'no') i
end subroutine write_vm_data_address
 
subroutine write_vm_jump_address (outp, relative_address, i_vm)
integer, intent(in) :: outp
integer(kind = rik), intent(in) :: relative_address
integer(kind = rik), intent(in) :: i_vm
 
write (outp, '(" (", I0, ") ", I0)', advance = 'no') &
& relative_address, i_vm + relative_address
end subroutine write_vm_jump_address
 
subroutine ensure_integer_is_vm_compatible (n)
integer(kind = rik), intent(in) :: n
!
! It would seem desirable to check this in the syntax analyzer,
! instead, so line and column numbers can be given. But checking
! here will not hurt.
!
if (n < vm_huge_negint .or. vm_huge_posint < n) then
call codegen_error_message
write (error_unit, '("integer is too large for the virtual machine: ", I0)') n
stop 1
end if
end subroutine ensure_integer_is_vm_compatible
 
subroutine codegen_error_message
write (error_unit, '("Code generation error: ")', advance = 'no')
end subroutine codegen_error_message
 
end module code_generation
 
program gen
use, intrinsic :: iso_fortran_env, only: input_unit
use, intrinsic :: iso_fortran_env, only: output_unit
use, intrinsic :: iso_fortran_env, only: error_unit
use, non_intrinsic :: compiler_type_kinds
use, non_intrinsic :: string_buffers
use, non_intrinsic :: ast_reader
use, non_intrinsic :: code_generation
 
implicit none
 
integer, parameter :: inp_unit_no = 100
integer, parameter :: outp_unit_no = 101
 
integer :: arg_count
character(200) :: arg
integer :: inp
integer :: outp
 
type(strbuf_t) :: strbuf
type(ast_t) :: ast
type(string_table_t) :: symtab
type(string_table_t) :: strtab
 
arg_count = command_argument_count ()
if (3 <= arg_count) then
call print_usage
else
if (arg_count == 0) then
inp = input_unit
outp = output_unit
else if (arg_count == 1) then
call get_command_argument (1, arg)
inp = open_for_input (trim (arg))
outp = output_unit
else if (arg_count == 2) then
call get_command_argument (1, arg)
inp = open_for_input (trim (arg))
call get_command_argument (2, arg)
outp = open_for_output (trim (arg))
end if
 
call read_ast (inp, strbuf, ast, symtab, strtab)
call generate_and_output_code (outp, ast, symtab, strtab)
end if
 
contains
 
function open_for_input (filename) result (unit_no)
character(*), intent(in) :: filename
integer :: unit_no
 
integer :: stat
 
open (unit = inp_unit_no, file = filename, status = 'old', &
& action = 'read', access = 'stream', form = 'unformatted', &
& iostat = stat)
if (stat /= 0) then
write (error_unit, '("Error: failed to open ", 1A, " for input")') filename
stop 1
end if
unit_no = inp_unit_no
end function open_for_input
 
function open_for_output (filename) result (unit_no)
character(*), intent(in) :: filename
integer :: unit_no
 
integer :: stat
 
open (unit = outp_unit_no, file = filename, action = 'write', iostat = stat)
if (stat /= 0) then
write (error_unit, '("Error: failed to open ", 1A, " for output")') filename
stop 1
end if
unit_no = outp_unit_no
end function open_for_output
 
subroutine print_usage
character(200) :: progname
 
call get_command_argument (0, progname)
write (output_unit, '("Usage: ", 1A, " [INPUT_FILE [OUTPUT_FILE]]")') &
& trim (progname)
end subroutine print_usage
end program gen</syntaxhighlight>
 
{{out}}
$ ./lex compiler-tests/count.t | ./parse | ./gen
<pre>Datasize: 1 Strings: 2
"count is: "
"\n"
0 push 1
5 store [0]
10 fetch [0]
15 push 10
20 lt
21 jz (43) 65
26 push 0
31 prts
32 fetch [0]
37 prti
38 push 1
43 prts
44 fetch [0]
49 push 1
54 add
55 store [0]
60 jmp (-51) 10
65 halt</pre>
 
=={{header|Go}}==
{{trans|C}}
<syntaxhighlight lang="go">package main
 
import (
"bufio"
"encoding/binary"
"fmt"
"log"
"os"
"strconv"
"strings"
)
 
type NodeType int
 
const (
ndIdent NodeType = iota
ndString
ndInteger
ndSequence
ndIf
ndPrtc
ndPrts
ndPrti
ndWhile
ndAssign
ndNegate
ndNot
ndMul
ndDiv
ndMod
ndAdd
ndSub
ndLss
ndLeq
ndGtr
ndGeq
ndEql
ndNeq
ndAnd
ndOr
)
 
type code = byte
 
const (
fetch code = iota
store
push
add
sub
mul
div
mod
lt
gt
le
ge
eq
ne
and
or
neg
not
jmp
jz
prtc
prts
prti
halt
)
 
type Tree struct {
nodeType NodeType
left *Tree
right *Tree
value string
}
 
// dependency: Ordered by NodeType, must remain in same order as NodeType enum
type atr struct {
enumText string
nodeType NodeType
opcode code
}
 
var atrs = []atr{
{"Identifier", ndIdent, 255},
{"String", ndString, 255},
{"Integer", ndInteger, 255},
{"Sequence", ndSequence, 255},
{"If", ndIf, 255},
{"Prtc", ndPrtc, 255},
{"Prts", ndPrts, 255},
{"Prti", ndPrti, 255},
{"While", ndWhile, 255},
{"Assign", ndAssign, 255},
{"Negate", ndNegate, neg},
{"Not", ndNot, not},
{"Multiply", ndMul, mul},
{"Divide", ndDiv, div},
{"Mod", ndMod, mod},
{"Add", ndAdd, add},
{"Subtract", ndSub, sub},
{"Less", ndLss, lt},
{"LessEqual", ndLeq, le},
{"Greater", ndGtr, gt},
{"GreaterEqual", ndGeq, ge},
{"Equal", ndEql, eq},
{"NotEqual", ndNeq, ne},
{"And", ndAnd, and},
{"Or", ndOr, or},
}
 
var (
stringPool []string
globals []string
object []code
)
 
var (
err error
scanner *bufio.Scanner
)
 
func reportError(msg string) {
log.Fatalf("error : %s\n", msg)
}
 
func check(err error) {
if err != nil {
log.Fatal(err)
}
}
 
func nodeType2Op(nodeType NodeType) code {
return atrs[nodeType].opcode
}
 
func makeNode(nodeType NodeType, left *Tree, right *Tree) *Tree {
return &Tree{nodeType, left, right, ""}
}
 
func makeLeaf(nodeType NodeType, value string) *Tree {
return &Tree{nodeType, nil, nil, value}
}
 
/*** Code generator ***/
 
func emitByte(c code) {
object = append(object, c)
}
 
func emitWord(n int) {
bs := make([]byte, 4)
binary.LittleEndian.PutUint32(bs, uint32(n))
for _, b := range bs {
emitByte(code(b))
}
}
 
func emitWordAt(at, n int) {
bs := make([]byte, 4)
binary.LittleEndian.PutUint32(bs, uint32(n))
for i := at; i < at+4; i++ {
object[i] = code(bs[i-at])
}
}
 
func hole() int {
t := len(object)
emitWord(0)
return t
}
 
func fetchVarOffset(id string) int {
for i := 0; i < len(globals); i++ {
if globals[i] == id {
return i
}
}
globals = append(globals, id)
return len(globals) - 1
}
 
func fetchStringOffset(st string) int {
for i := 0; i < len(stringPool); i++ {
if stringPool[i] == st {
return i
}
}
stringPool = append(stringPool, st)
return len(stringPool) - 1
}
 
func codeGen(x *Tree) {
if x == nil {
return
}
var n, p1, p2 int
switch x.nodeType {
case ndIdent:
emitByte(fetch)
n = fetchVarOffset(x.value)
emitWord(n)
case ndInteger:
emitByte(push)
n, err = strconv.Atoi(x.value)
check(err)
emitWord(n)
case ndString:
emitByte(push)
n = fetchStringOffset(x.value)
emitWord(n)
case ndAssign:
n = fetchVarOffset(x.left.value)
codeGen(x.right)
emitByte(store)
emitWord(n)
case ndIf:
codeGen(x.left) // if expr
emitByte(jz) // if false, jump
p1 = hole() // make room forjump dest
codeGen(x.right.left) // if true statements
if x.right.right != nil {
emitByte(jmp)
p2 = hole()
}
emitWordAt(p1, len(object)-p1)
if x.right.right != nil {
codeGen(x.right.right)
emitWordAt(p2, len(object)-p2)
}
case ndWhile:
p1 = len(object)
codeGen(x.left) // while expr
emitByte(jz) // if false, jump
p2 = hole() // make room for jump dest
codeGen(x.right) // statements
emitByte(jmp) // back to the top
emitWord(p1 - len(object)) // plug the top
emitWordAt(p2, len(object)-p2) // plug the 'if false, jump'
case ndSequence:
codeGen(x.left)
codeGen(x.right)
case ndPrtc:
codeGen(x.left)
emitByte(prtc)
case ndPrti:
codeGen(x.left)
emitByte(prti)
case ndPrts:
codeGen(x.left)
emitByte(prts)
case ndLss, ndGtr, ndLeq, ndGeq, ndEql, ndNeq,
ndAnd, ndOr, ndSub, ndAdd, ndDiv, ndMul, ndMod:
codeGen(x.left)
codeGen(x.right)
emitByte(nodeType2Op(x.nodeType))
case ndNegate, ndNot:
codeGen(x.left)
emitByte(nodeType2Op(x.nodeType))
default:
msg := fmt.Sprintf("error in code generator - found %d, expecting operator\n", x.nodeType)
reportError(msg)
}
}
 
func codeFinish() {
emitByte(halt)
}
 
func listCode() {
fmt.Printf("Datasize: %d Strings: %d\n", len(globals), len(stringPool))
for _, s := range stringPool {
fmt.Println(s)
}
pc := 0
for pc < len(object) {
fmt.Printf("%5d ", pc)
op := object[pc]
pc++
switch op {
case fetch:
x := int32(binary.LittleEndian.Uint32(object[pc : pc+4]))
fmt.Printf("fetch [%d]\n", x)
pc += 4
case store:
x := int32(binary.LittleEndian.Uint32(object[pc : pc+4]))
fmt.Printf("store [%d]\n", x)
pc += 4
case push:
x := int32(binary.LittleEndian.Uint32(object[pc : pc+4]))
fmt.Printf("push %d\n", x)
pc += 4
case add:
fmt.Println("add")
case sub:
fmt.Println("sub")
case mul:
fmt.Println("mul")
case div:
fmt.Println("div")
case mod:
fmt.Println("mod")
case lt:
fmt.Println("lt")
case gt:
fmt.Println("gt")
case le:
fmt.Println("le")
case ge:
fmt.Println("ge")
case eq:
fmt.Println("eq")
case ne:
fmt.Println("ne")
case and:
fmt.Println("and")
case or:
fmt.Println("or")
case neg:
fmt.Println("neg")
case not:
fmt.Println("not")
case jmp:
x := int32(binary.LittleEndian.Uint32(object[pc : pc+4]))
fmt.Printf("jmp (%d) %d\n", x, int32(pc)+x)
pc += 4
case jz:
x := int32(binary.LittleEndian.Uint32(object[pc : pc+4]))
fmt.Printf("jz (%d) %d\n", x, int32(pc)+x)
pc += 4
case prtc:
fmt.Println("prtc")
case prti:
fmt.Println("prti")
case prts:
fmt.Println("prts")
case halt:
fmt.Println("halt")
default:
reportError(fmt.Sprintf("listCode: Unknown opcode %d", op))
}
}
}
 
func getEnumValue(name string) NodeType {
for _, atr := range atrs {
if atr.enumText == name {
return atr.nodeType
}
}
reportError(fmt.Sprintf("Unknown token %s\n", name))
return -1
}
 
func loadAst() *Tree {
var nodeType NodeType
var s string
if scanner.Scan() {
line := strings.TrimRight(scanner.Text(), " \t")
tokens := strings.Fields(line)
first := tokens[0]
if first[0] == ';' {
return nil
}
nodeType = getEnumValue(first)
le := len(tokens)
if le == 2 {
s = tokens[1]
} else if le > 2 {
idx := strings.Index(line, `"`)
s = line[idx:]
}
}
check(scanner.Err())
if s != "" {
return makeLeaf(nodeType, s)
}
left := loadAst()
right := loadAst()
return makeNode(nodeType, left, right)
}
 
func main() {
ast, err := os.Open("ast.txt")
check(err)
defer ast.Close()
scanner = bufio.NewScanner(ast)
codeGen(loadAst())
codeFinish()
listCode()
}</syntaxhighlight>
 
{{out}}
while counter example:
<pre>
Datasize: 1 Strings: 2
"count is: "
"\n"
0 push 1
5 store [0]
10 fetch [0]
15 push 10
20 lt
21 jz (43) 65
26 push 0
31 prts
32 fetch [0]
37 prti
38 push 1
43 prts
44 fetch [0]
49 push 1
54 add
55 store [0]
60 jmp (-51) 10
65 halt
</pre>
 
=={{header|J}}==
 
Implementation:
<syntaxhighlight lang="j">require'format/printf'
 
(opcodes)=: opcodes=: ;:{{)n
fetch store push add sub mul div mod lt gt le ge
eq ne and or neg not jmp jz prtc prts prti halt
}}-.LF
 
(ndDisp)=: ndDisp=:;:{{)n
Sequence Multiply Divide Mod Add Subtract Negate Less LessEqual Greater
GreaterEqual Equal NotEqual Not And Or Prts Assign Prti x If x x x While
x x Prtc x Identifier String Integer
}}-.LF
 
ndDisp,.ndOps=:;: {{)n
x mul div mod add sub neg lt le gt ge eq ne not and or
x x x x x x x x x x x x x x x x
}} -.LF
 
load_ast=: {{
'node_types node_values'=: 2{.|:(({.,&<&<}.@}.)~ i.&' ');._2 y
1{::0 load_ast ''
:
node_type=. x{::node_types
if. node_type-:,';' do. x;a: return.end.
node_value=. x{::node_values
if. -.''-:node_value do.x;<node_type make_leaf node_value return.end.
'x left'=.(x+1) load_ast''
'x right'=.(x+1) load_ast''
x;<node_type make_node left right
}}
 
make_leaf=: ;
make_node=: {{m;n;<y}}
typ=: 0&{::
val=: left=: 1&{::
right=: 2&{::
 
gen_code=: {{
if.y-:'' do.'' return.end.
V=. val y
W=. ;2}.y
select.op=.typ y
case.'Integer'do.gen_int _".V [ gen_op push
case.'String'do.gen_string V [ gen_op push
case.'Identifier'do.gen_var V [ gen_op fetch
case.'Assign'do.gen_var left V [ gen_op store [ gen_code W
case.;:'Multiply Divide Mod Add Subtract Less LessEqual Greater GreaterEqual Equal NotEqual And Or'do.
gen_op op [ gen_code W [ gen_code V
case.;:'Not Negate'do.
gen_op op [ gen_code V
case.'If'do.
p1=. gen_int 0 [ gen_op jz [ gen_code V
gen_code left W
if.#right W do.
p2=. gen_int 0 [ gen_op jmp
gen_code right W [ p1 patch #object
p2 patch #object
else.
p1 patch #object
end.
case.'While'do.
p1=. #object
p2=. gen_int 0 [ gen_op jz [ gen_code V
gen_int p1 [ gen_op jmp [ gen_code W
p2 patch #object
case.'Prtc'do.gen_op prtc [ gen_code V
case.'Prti'do.gen_op prti [ gen_code V
case.'Prts'do.gen_op prts [ gen_code V
case.'Sequence'do.
gen_code W [ gen_code V
case.do.error'unknown node type ',typ y
end.
}}
 
gen_op=:{{
arg=. boxopen y
if. -.arg e. opcodes do.
arg=. (ndDisp i. arg){ndOps
end.
assert. arg e. opcodes
object=: object,opcodes i.arg
}}
 
gen_int=:{{
if.#$y do.num=. _ ".y
else.num=. y end.
r=. #object
object=: object,(4#256)#:num
r
}}
 
gen_string=: {{
strings=:~.strings,<y
gen_int strings i.<y
}}
 
gen_var=: {{
vars=:~.vars,<y
gen_int vars i.<y
}}
 
patch=: {{ #object=: ((4#256)#:y) (x+i.4)} object }}
error=: {{echo y throw.}}
getint=: _2147483648+4294967296|2147483648+256#.]
 
list_code=: {{
r=.'Datasize: %d Strings: %d\n' sprintf vars;&#strings
r=.r,;strings,each LF
pc=. 0
lim=.<:#object
while.do.
op=.(pc{object){::opcodes
r=.r,'%5d %s'sprintf pc;op
pc=. pc+1
i=. getint (lim<.pc+i.4){object
k=. 0
select.op
case.fetch;store do.k=.4[r=.r,' [%d]'sprintf i
case.push do.k=.4[r=.r,' %d'sprintf i
case.jmp;jz do.k=.4[r=.r,' (%d) %d'sprintf (i-pc);i
case.halt do.r=.r,LF return.
end.
pc=.pc+k
r=.r,LF
end.
}}
 
gen=: {{
object=:strings=:vars=:i.0
gen_code load_ast y
list_code gen_op halt
}}</syntaxhighlight>
 
Count example:
<syntaxhighlight lang="j">
count=:{{)n
count = 1;
while (count < 10) {
print("count is: ", count, "\n");
count = count + 1;
}
}}
 
gen syntax lex count
Datasize: 1 Strings: 2
"count is: "
"\n"
0 push 1
5 store [0]
10 fetch [0]
15 push 10
20 lt
21 jz (43) 65
26 push 0
31 prts
32 fetch [0]
37 prti
38 push 1
43 prts
44 fetch [0]
49 push 1
54 add
55 store [0]
60 jmp (-51) 10
65 halt
</syntaxhighlight>
 
=={{header|Java}}==
{{trans|Python}}
<syntaxhighlight lang="java">package codegenerator;
 
import java.io.File;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Scanner;
 
public class CodeGenerator {
final static int WORDSIZE = 4;
static byte[] code = {};
static Map<String, NodeType> str_to_nodes = new HashMap<>();
static List<String> string_pool = new ArrayList<>();
static List<String> variables = new ArrayList<>();
static int string_count = 0;
static int var_count = 0;
static Scanner s;
static NodeType[] unary_ops = {
NodeType.nd_Negate, NodeType.nd_Not
};
static NodeType[] operators = {
NodeType.nd_Mul, NodeType.nd_Div, NodeType.nd_Mod, NodeType.nd_Add, NodeType.nd_Sub,
NodeType.nd_Lss, NodeType.nd_Leq, NodeType.nd_Gtr, NodeType.nd_Geq,
NodeType.nd_Eql, NodeType.nd_Neq, NodeType.nd_And, NodeType.nd_Or
};
static enum Mnemonic {
NONE, FETCH, STORE, PUSH, ADD, SUB, MUL, DIV, MOD, LT, GT, LE, GE, EQ, NE, AND, OR, NEG, NOT,
JMP, JZ, PRTC, PRTS, PRTI, HALT
}
static class Node {
public NodeType nt;
public Node left, right;
public String value;
 
Node() {
this.nt = null;
this.left = null;
this.right = null;
this.value = null;
}
Node(NodeType node_type, Node left, Node right, String value) {
this.nt = node_type;
this.left = left;
this.right = right;
this.value = value;
}
public static Node make_node(NodeType nodetype, Node left, Node right) {
return new Node(nodetype, left, right, "");
}
public static Node make_node(NodeType nodetype, Node left) {
return new Node(nodetype, left, null, "");
}
public static Node make_leaf(NodeType nodetype, String value) {
return new Node(nodetype, null, null, value);
}
}
static enum NodeType {
nd_None("", Mnemonic.NONE), nd_Ident("Identifier", Mnemonic.NONE), nd_String("String", Mnemonic.NONE), nd_Integer("Integer", Mnemonic.NONE), nd_Sequence("Sequence", Mnemonic.NONE),
nd_If("If", Mnemonic.NONE),
nd_Prtc("Prtc", Mnemonic.NONE), nd_Prts("Prts", Mnemonic.NONE), nd_Prti("Prti", Mnemonic.NONE), nd_While("While", Mnemonic.NONE),
nd_Assign("Assign", Mnemonic.NONE),
nd_Negate("Negate", Mnemonic.NEG), nd_Not("Not", Mnemonic.NOT), nd_Mul("Multiply", Mnemonic.MUL), nd_Div("Divide", Mnemonic.DIV), nd_Mod("Mod", Mnemonic.MOD), nd_Add("Add", Mnemonic.ADD),
nd_Sub("Subtract", Mnemonic.SUB), nd_Lss("Less", Mnemonic.LT), nd_Leq("LessEqual", Mnemonic.LE),
nd_Gtr("Greater", Mnemonic.GT), nd_Geq("GreaterEqual", Mnemonic.GE), nd_Eql("Equal", Mnemonic.EQ),
nd_Neq("NotEqual", Mnemonic.NE), nd_And("And", Mnemonic.AND), nd_Or("Or", Mnemonic.OR);
 
private final String name;
private final Mnemonic m;
 
NodeType(String name, Mnemonic m) {
this.name = name;
this.m = m;
}
Mnemonic getMnemonic() { return this.m; }
 
@Override
public String toString() { return this.name; }
}
static void appendToCode(int b) {
code = Arrays.copyOf(code, code.length + 1);
code[code.length - 1] = (byte) b;
}
static void emit_byte(Mnemonic m) {
appendToCode(m.ordinal());
}
static void emit_word(int n) {
appendToCode(n >> 24);
appendToCode(n >> 16);
appendToCode(n >> 8);
appendToCode(n);
}
static void emit_word_at(int pos, int n) {
code[pos] = (byte) (n >> 24);
code[pos + 1] = (byte) (n >> 16);
code[pos + 2] = (byte) (n >> 8);
code[pos + 3] = (byte) n;
}
static int get_word(int pos) {
int result;
result = ((code[pos] & 0xff) << 24) + ((code[pos + 1] & 0xff) << 16) + ((code[pos + 2] & 0xff) << 8) + (code[pos + 3] & 0xff) ;
return result;
}
static int fetch_var_offset(String name) {
int n;
n = variables.indexOf(name);
if (n == -1) {
variables.add(name);
n = var_count++;
}
return n;
}
static int fetch_string_offset(String str) {
int n;
n = string_pool.indexOf(str);
if (n == -1) {
string_pool.add(str);
n = string_count++;
}
return n;
}
static int hole() {
int t = code.length;
emit_word(0);
return t;
}
static boolean arrayContains(NodeType[] a, NodeType n) {
boolean result = false;
for (NodeType test: a) {
if (test.equals(n)) {
result = true;
break;
}
}
return result;
}
static void code_gen(Node x) throws Exception {
int n, p1, p2;
if (x == null) return;
switch (x.nt) {
case nd_None: return;
case nd_Ident:
emit_byte(Mnemonic.FETCH);
n = fetch_var_offset(x.value);
emit_word(n);
break;
case nd_Integer:
emit_byte(Mnemonic.PUSH);
emit_word(Integer.parseInt(x.value));
break;
case nd_String:
emit_byte(Mnemonic.PUSH);
n = fetch_string_offset(x.value);
emit_word(n);
break;
case nd_Assign:
n = fetch_var_offset(x.left.value);
code_gen(x.right);
emit_byte(Mnemonic.STORE);
emit_word(n);
break;
case nd_If:
p2 = 0; // to avoid NetBeans complaining about 'not initialized'
code_gen(x.left);
emit_byte(Mnemonic.JZ);
p1 = hole();
code_gen(x.right.left);
if (x.right.right != null) {
emit_byte(Mnemonic.JMP);
p2 = hole();
}
emit_word_at(p1, code.length - p1);
if (x.right.right != null) {
code_gen(x.right.right);
emit_word_at(p2, code.length - p2);
}
break;
case nd_While:
p1 = code.length;
code_gen(x.left);
emit_byte(Mnemonic.JZ);
p2 = hole();
code_gen(x.right);
emit_byte(Mnemonic.JMP);
emit_word(p1 - code.length);
emit_word_at(p2, code.length - p2);
break;
case nd_Sequence:
code_gen(x.left);
code_gen(x.right);
break;
case nd_Prtc:
code_gen(x.left);
emit_byte(Mnemonic.PRTC);
break;
case nd_Prti:
code_gen(x.left);
emit_byte(Mnemonic.PRTI);
break;
case nd_Prts:
code_gen(x.left);
emit_byte(Mnemonic.PRTS);
break;
default:
if (arrayContains(operators, x.nt)) {
code_gen(x.left);
code_gen(x.right);
emit_byte(x.nt.getMnemonic());
} else if (arrayContains(unary_ops, x.nt)) {
code_gen(x.left);
emit_byte(x.nt.getMnemonic());
} else {
throw new Exception("Error in code generator! Found " + x.nt + ", expecting operator.");
}
}
}
static void list_code() throws Exception {
int pc = 0, x;
Mnemonic op;
System.out.println("Datasize: " + var_count + " Strings: " + string_count);
for (String s: string_pool) {
System.out.println(s);
}
while (pc < code.length) {
System.out.printf("%4d ", pc);
op = Mnemonic.values()[code[pc++]];
switch (op) {
case FETCH:
x = get_word(pc);
System.out.printf("fetch [%d]", x);
pc += WORDSIZE;
break;
case STORE:
x = get_word(pc);
System.out.printf("store [%d]", x);
pc += WORDSIZE;
break;
case PUSH:
x = get_word(pc);
System.out.printf("push %d", x);
pc += WORDSIZE;
break;
case ADD: case SUB: case MUL: case DIV: case MOD:
case LT: case GT: case LE: case GE: case EQ: case NE:
case AND: case OR: case NEG: case NOT:
case PRTC: case PRTI: case PRTS: case HALT:
System.out.print(op.toString().toLowerCase());
break;
case JMP:
x = get_word(pc);
System.out.printf("jmp (%d) %d", x, pc + x);
pc += WORDSIZE;
break;
case JZ:
x = get_word(pc);
System.out.printf("jz (%d) %d", x, pc + x);
pc += WORDSIZE;
break;
default:
throw new Exception("Unknown opcode " + code[pc] + "@" + (pc - 1));
}
System.out.println();
}
}
static Node load_ast() throws Exception {
String command, value;
String line;
Node left, right;
 
while (s.hasNext()) {
line = s.nextLine();
value = null;
if (line.length() > 16) {
command = line.substring(0, 15).trim();
value = line.substring(15).trim();
} else {
command = line.trim();
}
if (command.equals(";")) {
return null;
}
if (!str_to_nodes.containsKey(command)) {
throw new Exception("Command not found: '" + command + "'");
}
if (value != null) {
return Node.make_leaf(str_to_nodes.get(command), value);
}
left = load_ast(); right = load_ast();
return Node.make_node(str_to_nodes.get(command), left, right);
}
return null; // for the compiler, not needed
}
public static void main(String[] args) {
Node n;
 
str_to_nodes.put(";", NodeType.nd_None);
str_to_nodes.put("Sequence", NodeType.nd_Sequence);
str_to_nodes.put("Identifier", NodeType.nd_Ident);
str_to_nodes.put("String", NodeType.nd_String);
str_to_nodes.put("Integer", NodeType.nd_Integer);
str_to_nodes.put("If", NodeType.nd_If);
str_to_nodes.put("While", NodeType.nd_While);
str_to_nodes.put("Prtc", NodeType.nd_Prtc);
str_to_nodes.put("Prts", NodeType.nd_Prts);
str_to_nodes.put("Prti", NodeType.nd_Prti);
str_to_nodes.put("Assign", NodeType.nd_Assign);
str_to_nodes.put("Negate", NodeType.nd_Negate);
str_to_nodes.put("Not", NodeType.nd_Not);
str_to_nodes.put("Multiply", NodeType.nd_Mul);
str_to_nodes.put("Divide", NodeType.nd_Div);
str_to_nodes.put("Mod", NodeType.nd_Mod);
str_to_nodes.put("Add", NodeType.nd_Add);
str_to_nodes.put("Subtract", NodeType.nd_Sub);
str_to_nodes.put("Less", NodeType.nd_Lss);
str_to_nodes.put("LessEqual", NodeType.nd_Leq);
str_to_nodes.put("Greater", NodeType.nd_Gtr);
str_to_nodes.put("GreaterEqual", NodeType.nd_Geq);
str_to_nodes.put("Equal", NodeType.nd_Eql);
str_to_nodes.put("NotEqual", NodeType.nd_Neq);
str_to_nodes.put("And", NodeType.nd_And);
str_to_nodes.put("Or", NodeType.nd_Or);
 
if (args.length > 0) {
try {
s = new Scanner(new File(args[0]));
n = load_ast();
code_gen(n);
emit_byte(Mnemonic.HALT);
list_code();
} catch (Exception e) {
System.out.println("Ex: "+e);//.getMessage());
}
}
}
}
</syntaxhighlight>
 
=={{header|Julia}}==
<syntaxhighlight lang="julia">import Base.show
 
mutable struct Asm32
offset::Int32
code::String
arg::Int32
targ::Int32
end
Asm32(code, arg = 0) = Asm32(0, code, arg, 0)
 
show(io::IO, a::Asm32) = print(io, lpad("$(a.offset)", 6), lpad(a.code, 8),
a.targ > 0 ? (lpad("($(a.arg))", 8) * lpad("$(a.targ)", 4)) :
(a.code in ["store", "fetch"] ? lpad("[$(a.arg)]", 8) :
(a.code in ["push"] ? lpad("$(a.arg)", 8) : "")))
 
const ops32 = Dict{String,String}("Multiply" => "mul", "Divide" => "div", "Mod" => "mod", "Add" => "add",
"Subtract" => "sub", "Less" => "lt", "Greater" => "gt", "LessEqual" => "le", "GreaterEqual" => "ge",
"Equal" => "eq", "NotEqual" => "ne", "And" => "and", "or" => "or", "Not" => "not", "Minus" => "neg",
"Prtc" => "prtc", "Prti" => "prti", "Prts" => "prts")
 
function compiletoasm(io)
identifiers = Vector{String}()
strings = Vector{String}()
labels = Vector{Int}()
 
function cpile(io, islefthandside = false)
arr = Vector{Asm32}()
jlabel() = (push!(labels, length(labels) + 1); labels[end])
m = match(r"^(\w+|;)\s*([\d\w\"\\ \S]+)?", strip(readline(io)))
x, val = m == nothing ? Pair(";", 0) : m.captures
if x == ";" return arr
elseif x == "Assign"
lhs = cpile(io, true)
rhs = cpile(io)
append!(arr, rhs)
append!(arr, lhs)
if length(arr) > 100 exit() end
elseif x == "Integer" push!(arr, Asm32("push", parse(Int32, val)))
elseif x == "String"
if !(val in strings)
push!(strings, val)
end
push!(arr, Asm32("push", findfirst(x -> x == val, strings) - 1))
elseif x == "Identifier"
if !(val in identifiers)
if !islefthandside
throw("Identifier $val referenced before it is assigned")
end
push!(identifiers, val)
end
push!(arr, Asm32(islefthandside ? "store" : "fetch", findfirst(x -> x == val, identifiers) - 1))
elseif haskey(ops32, x)
append!(arr, cpile(io))
append!(arr, cpile(io))
push!(arr, Asm32(ops32[x]))
elseif x == "If"
append!(arr, cpile(io))
x, y = jlabel(), jlabel()
push!(arr, Asm32("jz", x))
append!(arr, cpile(io))
push!(arr, Asm32("jmp", y))
a = cpile(io)
if length(a) < 1
push!(a, Asm32("nop", 0))
end
a[1].offset = x
append!(arr, a)
push!(arr, Asm32(y, "nop", 0, 0)) # placeholder
elseif x == "While"
x, y = jlabel(), jlabel()
a = cpile(io)
if length(a) < 1
push!(a, Asm32("nop", 0))
end
a[1].offset = x
append!(arr, a)
push!(arr, Asm32("jz", y))
append!(arr, cpile(io))
push!(arr, Asm32("jmp", x), Asm32(y, "nop", 0, 0))
elseif x == "Sequence"
append!(arr, cpile(io))
append!(arr, cpile(io))
else
throw("unknown node type: $x")
end
arr
end
 
# compile AST
asmarr = cpile(io)
push!(asmarr, Asm32("halt"))
# move address markers to working code and prune nop code
for (i, acode) in enumerate(asmarr)
if acode.code == "nop" && acode.offset != 0 && i < length(asmarr)
asmarr[i + 1].offset = asmarr[i].offset
end
end
filter!(x -> x.code != "nop", asmarr)
# renumber offset column with actual offsets
pos = 0
jmps = Dict{Int, Int}()
for acode in asmarr
if acode.offset > 0
jmps[acode.offset] = pos
end
acode.offset = pos
pos += acode.code in ["push", "store", "fetch", "jz", "jmp"] ? 5 : 1
end
# fix up jump destinations
for acode in asmarr
if acode.code in ["jz", "jmp"]
if haskey(jmps, acode.arg)
acode.targ = jmps[acode.arg]
acode.arg = acode.targ - acode.offset -1
else
throw("unknown jump location: $acode")
end
end
end
# print Datasize and Strings header
println("Datasize: $(length(identifiers)) Strings: $(length(strings))\n" *
join(strings, "\n") )
# print assembly lines
foreach(println, asmarr)
end
 
const testAST = raw"""
Sequence
Sequence
;
Assign
Identifier count
Integer 1
While
Less
Identifier count
Integer 10
Sequence
Sequence
;
Sequence
Sequence
Sequence
;
Prts
String "count is: "
;
Prti
Identifier count
;
Prts
String "\n"
;
Assign
Identifier count
Add
Identifier count
Integer 1 """
 
iob = IOBuffer(testAST) # use an io buffer here for testing, but could use stdin instead of iob
 
compiletoasm(iob)
</syntaxhighlight>{{output}}<pre>
Datasize: 1 Strings: 2
"count is: "
"\n"
0 push 1
5 store [0]
10 fetch [0]
15 push 10
20 lt
21 jz (43) 65
26 push 0
31 prts
32 fetch [0]
37 prti
38 push 1
43 prts
44 fetch [0]
49 push 1
54 add
55 store [0]
60 jmp (-51) 10
65 halt
</pre>
 
=={{header|M2000 Interpreter}}==
<syntaxhighlight lang="m2000 interpreter">
Module CodeGenerator (s$){
Function code$(op$) {
=format$("{0::-6} {1}", pc, op$)
pc++
}
Function code2$(op$, n$) {
=format$("{0::-6} {1} {2}", pc, op$, n$)
pc+=5
}
Function code3$(op$,pc, st, ed) {
=format$("{0::-6} {1} ({2}) {3}", pc, op$, ed-st-1, ed)
}
Enum tok {
gneg, gnot, gmul, gdiv, gmod, gadd, gle, gsub, glt
gle, ggt, gge, geq, gne, gand, gor, gprtc, gprti, gprts,
gif, gwhile, gAssign, gSeq, gstring, gidentifier, gint, gnone
}
 
\\ Inventories are lists with keys, or keys/data (key must be unique)
\\ there is one type more the Invetory Queue which get same keys.
\\ But here not used.
Inventory symb="Multiply":=gmul, "Divide":=gdiv, "Mod":=gmod, "Add":=gadd
Append symb, "Negate":=gneg, "Not":=gnot,"Less":=glt,"Subtract":=gsub
Append symb, "LessEqual":=gle, "Greater":=ggt, "GreaterEqual":=gge, "Sequence":=gSeq
Append symb, "Equal":=geq, "NotEqual":=gne, "And":=gand, "Or":=gor, "While":=gwhile
Append symb, "Prtc":=gprtc,"Prti":=gprti,"Prts":=gprts, "Assign":=gAssign, "If":=gif
Append symb, "String":=gstring, "Identifier":=gidentifier, "Integer":=gint, ";", gnone
 
Inventory DataSet
\\ We set string as key. key maybe an empty string, a string or a number.
\\ so we want eash string to saved one time only.
Inventory Strings
Const nl$=chr$(13)+chr$(10), Ansi=3
Def z$, lim, line$, newvar_ok, i=0
Document message$=nl$
Global pc \\ functions have own scope, so we make it global, for this module, and childs.
 
Dim lines$()
s$=filter$(s$,chr$(9)) \\ exclude tabs
Lines$()=piece$(s$,nl$) \\ break to lines
lim=len(Lines$())
Flush ' empty stack (there is a current stack of values which we use here)
Load_Ast()
If not stack.size=1 Then Flush : Error "Ast not loaded"
AST=array \\ pop the array from stack
Document Assembly$, Header$
 
\\ all lines of assembly goes to stack. Maybe not in right order.
\\ Push statement push to top, Data statement push to bottom of stack
CodeGenerator(Ast)
Data code$("halt") ' append to end of stack
\\ So now we get all data (letters) from stack
While not empty
Assembly$=letter$+nl$
end while
\\ So now we have to place them in order
Sort Assembly$
\\ Let's make the header
Header$=format$("Datasize: {0} Strings: {1}", Len(Dataset),Len(strings))
\\ we use an iterator object, str^ is the counter, readonly, but Eval$() use it from object.
str=each(strings)
While str
Header$=nl$+Eval$(str)
End while
Assembly$=nl$
\\ insert to line 1 the Header
Insert 1 Assembly$=Header$
\\ Also we check for warnings
If len(message$)>2 then Assembly$="Warnings: "+nl$+message$
\\ So now we get a report
\\ (at each 3/4 of window's lines, the printing stop and wait for user response, any key)
Report Assembly$
Clipboard Assembly$
Save.Doc Assembly$, "code.t", Ansi
End
\\ subs have 10000 limit for recursion but can be extended to 1000000 or more.
Sub CodeGenerator(t)
If len(t)=3 then
select case t#val(0)
Case gSeq
CodeGenerator(t#val(1)) : CodeGenerator(t#val(2))
Case gwhile
{
local spc=pc
CodeGenerator(t#val(1))
local pc1=pc
pc+=5 ' room for jz
CodeGenerator(t#val(2))
data code3$("jz",pc1, pc1, pc+5)
data code3$("jmp",pc, pc, spc)
pc+=5 ' room for jmp
}
Case gif
{
CodeGenerator(t#val(1))
local pc1=pc, pc2
pc+=5
CodeGenerator(t#val(2)#val(1))
If len(t#val(2)#val(2))>0 then
pc2=pc
pc+=5
data code3$("jz",pc1, pc1, pc)
CodeGenerator(t#val(2)#val(2))
data code3$("jmp",pc2, pc2, pc)
else
data code3$("jz",pc1, pc1, pc)
end If
}
Case gAssign
{
CodeGenerator(t#val(2))
local newvar_ok=true
CodeGenerator(t#val(1))
}
case gneg to gnot, gprtc to gprts
CodeGenerator(t#val(1)) : data code$(mid$(eval$(t#val(0)),2))
case gmul to gor
{
CodeGenerator(t#val(1))
CodeGenerator(t#val(2))
data code$(mid$(eval$(t#val(0)),2))
}
End select
Else.if len(t)=2 then
select case t#val(0)
Case gString
{
local spos
If exist(strings,t#val$(1)) then
spos=eval(strings!)
else
append strings, t#val$(1)
spos=len(strings)-1
end If
Push code2$("push",str$(spos,0))
}
Case gInt
Push code2$("push",t#val$(1), pc)
Case gIdentifier
{
local ipos
If exist(dataset,t#val$(1)) then
ipos=Eval(dataset!) ' return position
else.if newvar_ok then
Append dataset, t#val$(1)
ipos=len(dataset)-1
else
message$="Variable "+t#val$(1)+" not initialized"+nl$
end If
If newvar_ok then
Push code2$("store","["+str$(ipos, 0)+"]")
else
Push code2$("fetch","["+str$(ipos, 0)+"]")
end If
}
end select
End If
End Sub
Sub Load_Ast()
If i>=lim then Push (,) : exit sub
do
line$=Trim$(lines$(i))
I++
tok$=piece$(line$," ")(0)
until line$<>"" or i>=lim
If tok$="Identifier" then
Push (gidentifier,trim$(Mid$(line$,11)))
else.if tok$="Integer" then
long n=Val(Mid$(line$,8)) ' check overflow
Push (gint, Trim$(Mid$(line$,8)))
else.if tok$="String" then
Push (gstring,Trim$(Mid$(line$,7)))
else.if tok$=";" then
Push (,)
Else
local otok=symb(tok$)
Load_Ast()
Load_Ast()
Shift 2
Push (otok,array, array)
End If
End Sub
}
 
CodeGenerator {
Sequence
Sequence
;
Assign
Identifier count
Integer 1
While
Less
Identifier count
Integer 10
Sequence
Sequence
;
Sequence
Sequence
Sequence
;
Prts
String "count is: "
;
Prti
Identifier count
;
Prts
String "\n"
;
Assign
Identifier count
Add
Identifier count
Integer 1
}
</syntaxhighlight>
 
{{out}}
<pre style="height:30ex;overflow:scroll">
Datasize: 1 Strings: 2
"count is: "
"\n"
0 push
5 store [0]
10 fetch [0]
15 push
20 lt
21 jz (43) 65
26 push 0
31 prts
32 fetch [0]
37 prti
38 push 1
43 prts
44 fetch [0]
49 push
54 add
55 store [0]
60 jmp (-51) 10
65 halt
</pre >
 
=={{header|Nim}}==
 
<syntaxhighlight lang="nim">import os, re, streams, strformat, strutils, tables, std/decls
 
type
 
# AST node types.
NodeKind = enum
nIdentifier = "Identifier"
nString = "String"
nInteger = "Integer"
nSequence = "Sequence"
nIf = "If"
nPrtc = "Prtc"
nPrts = "Prts"
nPrti = "Prti"
nWhile = "While"
nAssign = "Assign"
nNegate = "Negate"
nNot = "Not"
nMultiply = "Multiply"
nDivide = "Divide"
nMod = "Mod"
nAdd = "Add"
nSubtract = "Subtract"
nLess = "Less"
nLessEqual = "LessEqual"
nGreater = "Greater"
nGreaterEqual = "GreaterEqual"
nEqual = "Equal"
nNotEqual = "NotEqual"
nAnd = "And"
nOr = "Or"
 
# Ast node description.
Node = ref object
left: Node
right: Node
case kind: NodeKind
of nString: stringVal: string
of nInteger: intVal: int
of nIdentifier: name: string
else: nil
 
# Virtual machine opcodes.
OpCode = enum
opFetch = "fetch"
opStore = "store"
opPush = "push"
opJmp = "jmp"
opJz = "jz"
opAdd = "add"
opSub = "sub"
opMul = "mul"
opDiv = "div"
opMod = "mod"
opLt = "lt"
opgt = "gt"
opLe = "le"
opGe = "ge"
opEq = "eq"
opNe = "ne"
opAnd = "and"
opOr = "or"
opNeg = "neg"
opNot = "not"
opPrtc = "prtc"
opPrti = "prti"
opPrts = "prts"
opHalt = "halt"
opInvalid = "invalid"
 
# Code generator context.
CodeGen = object
address: int # Current address in code part.
instr: seq[string] # List of instructions.
vars: Table[string, int] # Mapping variable name -> variable index.
strings: seq[string] # List of strings.
 
# Node ranges.
UnaryOpNode = range[nNegate..nNot]
BinaryOpNode = range[nMultiply..nOr]
PrintNode = range[nPrtc..nPrti]
 
 
const
 
# Mapping unary operator Node -> OpCode.
UnOp: array[UnaryOpNode, OpCode] = [opNeg, opNot]
 
# Mapping binary operator Node -> OpCode.
BinOp: array[BinaryOpNode, OpCode] = [opMul, opDiv, opMod, opAdd, opSub, opLt,
opLe, opGt, opGe, opEq, opNe, opAnd, opOr]
 
# Mapping print Node -> OpCode.
PrintOp: array[PrintNode, OpCode] = [opPrtc, opPrts, opPrti]
 
 
####################################################################################################
# Code generator.
 
proc genSimpleInst(gen: var CodeGen; opcode: OpCode) =
## Build a simple instruction (no operand).
gen.instr.add &"{gen.address:>5} {opcode}"
 
#---------------------------------------------------------------------------------------------------
 
proc genMemInst(gen: var CodeGen; opcode: OpCode; memIndex: int) =
## Build a memory access instruction (opFetch, opStore).
gen.instr.add &"{gen.address:>5} {opcode:<5} [{memIndex}]"
 
#---------------------------------------------------------------------------------------------------
 
proc genJumpInst(gen: var CodeGen; opcode: OpCode): int =
## Build a jump instruction. We use the letters X and Y as placeholders
## for the offset and the target address.
result = gen.instr.len
gen.instr.add &"{gen.address:>5} {opcode:<5} (X) Y"
 
#---------------------------------------------------------------------------------------------------
 
proc genPush(gen: var CodeGen; value: int) =
## Build a push instruction.
gen.instr.add &"{gen.address:>5} {opPush:<5} {value}"
 
#---------------------------------------------------------------------------------------------------
 
proc updateJumpInst(gen: var CodeGen; index: int; jumpAddress, targetAddress: int) =
## Update the offset and the target address of a jump instruction.
 
var instr {.byAddr.} = gen.instr[index]
let offset = targetAddress - jumpAddress - 1
for idx in countdown(instr.high, 0):
case instr[idx]
of 'Y':
instr[idx..idx] = $targetAddress
of 'X':
instr[idx..idx] = $offset
break
else:
discard
 
#---------------------------------------------------------------------------------------------------
 
proc process(gen: var CodeGen; node: Node) =
## Generate code for a node.
 
if node.isNil: return
 
case node.kind:
 
of nInteger:
gen.genPush(node.intVal)
inc gen.address, 5
 
of nIdentifier:
if node.name notin gen.vars:
gen.vars[node.name] = gen.vars.len
gen.genMemInst(opFetch, gen.vars[node.name])
inc gen.address, 5
 
of nString:
var index = gen.strings.find(node.stringVal)
if index < 0:
index = gen.strings.len
gen.strings.add(node.stringVal)
gen.genPush(index)
inc gen.address, 5
 
of nAssign:
gen.process(node.right)
if node.left.name notin gen.vars:
gen.vars[node.left.name] = gen.vars.len
gen.genMemInst(opStore, gen.vars[node.left.name])
inc gen.address, 5
 
of UnaryOpNode.low..UnaryOpNode.high:
gen.process(node.left)
gen.genSimpleInst(UnOp[node.kind])
inc gen.address
 
of BinaryOpNode.low..BinaryOpNode.high:
gen.process(node.left)
gen.process(node.right)
gen.genSimpleInst(BinOp[node.kind])
inc gen.address
 
of PrintNode.low..PrintNode.high:
gen.process(node.left)
gen.genSimpleInst(PrintOp[node.kind])
inc gen.address
 
of nIf:
# Generate condition expression.
gen.process(node.left)
# Generate jump if zero.
let jzAddr = gen.address
let jzInst = gen.genJumpInst(opJz)
inc gen.address, 5
# Generate then branch expression.
gen.process(node.right.left)
# If there is an "else" clause, generate unconditional jump
var jmpAddr, jmpInst: int
let hasElseClause = not node.right.right.isNil
if hasElseClause:
jmpAddr = gen.address
jmpInst = gen.genJumpInst(opJmp)
inc gen.address, 5
# Update JZ offset.
gen.updateJumpInst(jzInst, jzAddr, gen.address)
# Generate else expression.
if hasElseClause:
gen.process(node.right.right)
# Update JMP offset.
gen.updateJumpInst(jmpInst, jmpAddr, gen.address)
 
of nWhile:
let condAddr = gen.address
# Generate condition expression.
gen.process(node.left)
# Generate jump if zero.
let jzAddr = gen.address
let jzInst = gen.genJumpInst(opJz)
inc gen.address, 5
# Generate loop code.
gen.process(node.right)
# Generate unconditional jump.
let jmpAddr = gen.address
let jmpInst = gen.genJumpInst(opJmp)
inc gen.address, 5
# Update JMP offset.
gen.updateJumpInst(jmpInst, jmpAddr, condAddr)
# Update JZ offset.
gen.updateJumpInst(jzInst, jzAddr, gen.address)
 
of nSequence:
gen.process(node.left)
gen.process(node.right)
 
#---------------------------------------------------------------------------------------------------
 
proc run(gen: var CodeGen; ast: Node) =
## Run the code generator on the AST.
 
# Process recursively the nodes.
gen.process(ast)
gen.genSimpleInst(opHalt) # Add a Halt operator at the end.
 
# Output header.
echo &"Datasize: {gen.vars.len} Strings: {gen.strings.len}"
# Output strings.
for s in gen.strings:
echo s.escape().replace("\\x0A", "\\n")
# Output code.
for inst in gen.instr:
echo inst
 
####################################################################################################
# AST loader.
 
proc newNode(kind: NodeKind; left: Node; right: Node = nil): Node =
## Create a new node with given left and right children.
result = Node(kind: kind, left: left, right: right)
 
#---------------------------------------------------------------------------------------------------
 
proc loadAst(stream: Stream): Node =
## Load a linear AST and build a binary tree.
 
let line = stream.readLine().strip()
if line.startsWith(';'):
return nil
 
var fields = line.split(' ', 1)
let kind = parseEnum[NodeKind](fields[0])
if kind in {nIdentifier, nString, nInteger}:
if fields.len < 2:
raise newException(ValueError, "Missing value field for " & fields[0])
else:
fields[1] = fields[1].strip()
case kind
of nIdentifier:
return Node(kind: nIdentifier, name: fields[1])
of nString:
let str = fields[1].replacef(re"([^\\])(\\n)", "$1\n").replace(r"\\", r"\").replace("\"", "")
return Node(kind: nString, stringVal: str)
of nInteger:
return Node(kind: nInteger, intVal: parseInt(fields[1]))
else:
if fields.len > 1:
raise newException(ValueError, "Extra field for " & fields[0])
 
let left = stream.loadAst()
let right = stream.loadAst()
result = newNode(kind, left, right)
 
 
#———————————————————————————————————————————————————————————————————————————————————————————————————
 
var stream: Stream
var toClose = false
var codegen: CodeGen
 
if paramCount() < 1:
stream = newFileStream(stdin)
else:
stream = newFileStream(paramStr(1))
toClose = true
 
let ast = loadAst(stream)
if toClose: stream.close()
 
codegen.run(ast)</syntaxhighlight>
 
{{out}}
The code produced is compliant with the specification and can be executed by the virtual machine interpreter.
Example with ASCII Mandelbrot (https://rosettacode.org/wiki/Compiler/Sample_programs#Ascii_Mandlebrot).
 
<pre>Datasize: 15 Strings: 0
0 push 420
5 neg
6 store [0]
11 push 300
16 store [1]
21 push 300
26 store [2]
31 push 300
36 neg
37 store [3]
42 push 7
47 store [4]
52 push 15
57 store [5]
62 push 200
67 store [6]
72 fetch [2]
77 store [7]
82 fetch [7]
87 fetch [3]
92 gt
93 jz (329) 423
98 fetch [0]
103 store [8]
108 fetch [8]
113 fetch [1]
118 lt
119 jz (276) 396
124 push 0
129 store [9]
134 push 0
139 store [10]
144 push 32
149 store [11]
154 push 0
159 store [12]
164 fetch [12]
169 fetch [6]
174 lt
175 jz (193) 369
180 fetch [10]
185 fetch [10]
190 mul
191 push 200
196 div
197 store [13]
202 fetch [9]
207 fetch [9]
212 mul
213 push 200
218 div
219 store [14]
224 fetch [13]
229 fetch [14]
234 add
235 push 800
240 gt
241 jz (56) 298
246 push 48
251 fetch [12]
256 add
257 store [11]
262 fetch [12]
267 push 9
272 gt
273 jz (14) 288
278 push 64
283 store [11]
288 fetch [6]
293 store [12]
298 fetch [10]
303 fetch [9]
308 mul
309 push 100
314 div
315 fetch [7]
320 add
321 store [9]
326 fetch [13]
331 fetch [14]
336 sub
337 fetch [8]
342 add
343 store [10]
348 fetch [12]
353 push 1
358 add
359 store [12]
364 jmp (-201) 164
369 fetch [11]
374 prtc
375 fetch [8]
380 fetch [4]
385 add
386 store [8]
391 jmp (-284) 108
396 push 10
401 prtc
402 fetch [7]
407 fetch [5]
412 sub
413 store [7]
418 jmp (-337) 82
423 halt</pre>
 
=={{header|Perl}}==
Tested with perl v5.26.1
<syntaxhighlight lang="perl">#!/usr/bin/perl
 
use strict; # gen.pl - flatAST to stack machine code
use warnings; # http://www.rosettacode.org/wiki/Compiler/code_generator
 
my $stringcount = my $namecount = my $pairsym = my $pc = 0;
my (%strings, %names);
my %opnames = qw( Less lt LessEqual le Multiply mul Subtract sub Divide div
GreaterEqual ge Equal eq Greater gt NotEqual ne Negate neg );
 
sub tree
{
my ($A, $B) = ( '_' . ++$pairsym, '_' . ++$pairsym ); # labels for jumps
my $line = <> // return '';
(local $_, my $arg) = $line =~ /^(\w+|;)\s+(.*)/ or die "bad input $line";
/Identifier/ ? "fetch [@{[ $names{$arg} //= $namecount++ ]}]\n" :
/Sequence/ ? tree() . tree() :
/Integer/ ? "push $arg\n" :
/String/ ? "push @{[ $strings{$arg} //= $stringcount++ ]}\n" :
/Assign/ ? join '', reverse tree() =~ s/fetch/store/r, tree() :
/While/ ? "$A:\n@{[ tree() ]}jz $B\n@{[ tree() ]}jmp $A\n$B:\n" :
/If/ ? tree() . "jz $A\n@{[ !<> . # !<> skips second 'If'
tree() ]}jmp $B\n$A:\n@{[ tree() ]}$B:\n" :
/;/ ? '' :
tree() . tree() . ($opnames{$_} // lc) . "\n";
}
 
$_ = tree() . "halt\n";
 
s/^jmp\s+(\S+)\n(_\d+:\n)\1:\n/$2/gm; # remove jmp next
s/^(?=[a-z]\w*(.*))/ # add locations
(sprintf("%4d ", $pc), $pc += $1 ? 5 : 1)[0] /gem;
my %labels = /^(_\d+):(?=(?:\n_\d+:)*\n *(\d+) )/gm; # pc addr of labels
s/^ *(\d+) j(?:z|mp) *\K(_\d+)$/ (@{[ # fix jumps
$labels{$2} - $1 - 1]}) $labels{$2}/gm;
s/^_\d+.*\n//gm; # remove labels
 
print "Datasize: $namecount Strings: $stringcount\n";
print "$_\n" for sort { $strings{$a} <=> $strings{$b} } keys %strings;
print;</syntaxhighlight>
Passes all tests.
 
=={{header|Phix}}==
Reusing parse.e from the [[Compiler/syntax_analyzer#Phix|Syntax Analyzer task]]<br>
Deviates somewhat from the task specification in that it generates executable machine code.
<!--<syntaxhighlight lang="phix">(notonline)-->
<span style="color: #000080;font-style:italic;">--
-- demo\rosetta\Compiler\cgen.e
-- ============================
--
-- The reusable part of cgen.exw
--</span>
<span style="color: #008080;">without</span> <span style="color: #008080;">js</span> <span style="color: #000080;font-style:italic;">-- (machine code!)</span>
<span style="color: #008080;">include</span> <span style="color: #000000;">parse</span><span style="color: #0000FF;">.</span><span style="color: #000000;">e</span>
<span style="color: #008080;">global</span> <span style="color: #004080;">sequence</span> <span style="color: #000000;">vars</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{},</span>
<span style="color: #000000;">strings</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{},</span>
<span style="color: #000000;">stringptrs</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{}</span>
<span style="color: #008080;">global</span> <span style="color: #004080;">integer</span> <span style="color: #000000;">chain</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">0</span>
<span style="color: #008080;">global</span> <span style="color: #004080;">sequence</span> <span style="color: #000000;">code</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{}</span>
<span style="color: #008080;">function</span> <span style="color: #000000;">var_idx</span><span style="color: #0000FF;">(</span><span style="color: #004080;">sequence</span> <span style="color: #000000;">inode</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">if</span> <span style="color: #000000;">inode</span><span style="color: #0000FF;">[</span><span style="color: #000000;">1</span><span style="color: #0000FF;">]!=</span><span style="color: #000000;">tk_Identifier</span> <span style="color: #008080;">then</span> <span style="color: #0000FF;">?</span><span style="color: #000000;">9</span><span style="color: #0000FF;">/</span><span style="color: #000000;">0</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #004080;">string</span> <span style="color: #000000;">ident</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">inode</span><span style="color: #0000FF;">[</span><span style="color: #000000;">2</span><span style="color: #0000FF;">]</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">n</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">find</span><span style="color: #0000FF;">(</span><span style="color: #000000;">ident</span><span style="color: #0000FF;">,</span><span style="color: #000000;">vars</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">if</span> <span style="color: #000000;">n</span><span style="color: #0000FF;">=</span><span style="color: #000000;">0</span> <span style="color: #008080;">then</span>
<span style="color: #000000;">vars</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">append</span><span style="color: #0000FF;">(</span><span style="color: #000000;">vars</span><span style="color: #0000FF;">,</span><span style="color: #000000;">ident</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">n</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">vars</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #008080;">return</span> <span style="color: #000000;">n</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">function</span>
<span style="color: #008080;">function</span> <span style="color: #000000;">string_idx</span><span style="color: #0000FF;">(</span><span style="color: #004080;">sequence</span> <span style="color: #000000;">inode</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">if</span> <span style="color: #000000;">inode</span><span style="color: #0000FF;">[</span><span style="color: #000000;">1</span><span style="color: #0000FF;">]!=</span><span style="color: #000000;">tk_String</span> <span style="color: #008080;">then</span> <span style="color: #0000FF;">?</span><span style="color: #000000;">9</span><span style="color: #0000FF;">/</span><span style="color: #000000;">0</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #004080;">string</span> <span style="color: #000000;">s</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">inode</span><span style="color: #0000FF;">[</span><span style="color: #000000;">2</span><span style="color: #0000FF;">]</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">n</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">find</span><span style="color: #0000FF;">(</span><span style="color: #000000;">s</span><span style="color: #0000FF;">,</span><span style="color: #000000;">strings</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">if</span> <span style="color: #000000;">n</span><span style="color: #0000FF;">=</span><span style="color: #000000;">0</span> <span style="color: #008080;">then</span>
<span style="color: #000000;">strings</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">append</span><span style="color: #0000FF;">(</span><span style="color: #000000;">strings</span><span style="color: #0000FF;">,</span><span style="color: #000000;">s</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">stringptrs</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">append</span><span style="color: #0000FF;">(</span><span style="color: #000000;">stringptrs</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">n</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">strings</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #008080;">return</span> <span style="color: #000000;">n</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">function</span>
<span style="color: #008080;">function</span> <span style="color: #000000;">gen_size</span><span style="color: #0000FF;">(</span><span style="color: #004080;">object</span> <span style="color: #000000;">t</span><span style="color: #0000FF;">)</span>
<span style="color: #000080;font-style:italic;">-- note: must be kept precisely in sync with gen_rec!
-- (relentlessly tested via estsize/actsize)</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">size</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">0</span>
<span style="color: #008080;">if</span> <span style="color: #000000;">t</span><span style="color: #0000FF;">!=</span><span style="color: #004600;">NULL</span> <span style="color: #008080;">then</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">n_type</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">t</span><span style="color: #0000FF;">[</span><span style="color: #000000;">1</span><span style="color: #0000FF;">]</span>
<span style="color: #004080;">string</span> <span style="color: #000000;">node_type</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">tkNames</span><span style="color: #0000FF;">[</span><span style="color: #000000;">n_type</span><span style="color: #0000FF;">]</span>
<span style="color: #008080;">switch</span> <span style="color: #000000;">n_type</span> <span style="color: #008080;">do</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">tk_Sequence</span><span style="color: #0000FF;">:</span>
<span style="color: #000000;">size</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">gen_size</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">[</span><span style="color: #000000;">2</span><span style="color: #0000FF;">])</span>
<span style="color: #000000;">size</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">gen_size</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">[</span><span style="color: #000000;">3</span><span style="color: #0000FF;">])</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">tk_assign</span><span style="color: #0000FF;">:</span>
<span style="color: #000000;">size</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">gen_size</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">[</span><span style="color: #000000;">3</span><span style="color: #0000FF;">])+</span><span style="color: #000000;">6</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">tk_Integer</span><span style="color: #0000FF;">:</span>
<span style="color: #000000;">size</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">5</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">tk_Identifier</span><span style="color: #0000FF;">:</span>
<span style="color: #000000;">size</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">6</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">tk_String</span><span style="color: #0000FF;">:</span>
<span style="color: #000000;">size</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">5</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">tk_while</span><span style="color: #0000FF;">:</span>
<span style="color: #000080;font-style:italic;">-- emit: @@:&lt;condition&gt;&lt;topjmp(@f)&gt;&lt;body&gt;&lt;tailjmp(@b)&gt;@@:</span>
<span style="color: #000000;">size</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">gen_size</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">[</span><span style="color: #000000;">2</span><span style="color: #0000FF;">])+</span><span style="color: #000000;">3</span>
<span style="color: #004080;">integer</span> <span style="color: #7060A8;">body</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">gen_size</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">[</span><span style="color: #000000;">3</span><span style="color: #0000FF;">])</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">stail</span> <span style="color: #0000FF;">=</span> <span style="color: #008080;">iff</span><span style="color: #0000FF;">(</span><span style="color: #000000;">size</span><span style="color: #0000FF;">+</span><span style="color: #7060A8;">body</span><span style="color: #0000FF;">+</span><span style="color: #000000;">2</span><span style="color: #0000FF;">></span><span style="color: #000000;">128</span><span style="color: #0000FF;">?</span><span style="color: #000000;">5</span><span style="color: #0000FF;">:</span><span style="color: #000000;">2</span><span style="color: #0000FF;">)</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">stop</span> <span style="color: #0000FF;">=</span> <span style="color: #008080;">iff</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">body</span><span style="color: #0000FF;">+</span><span style="color: #000000;">stail</span> <span style="color: #0000FF;">></span><span style="color: #000000;">127</span><span style="color: #0000FF;">?</span><span style="color: #000000;">6</span><span style="color: #0000FF;">:</span><span style="color: #000000;">2</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">size</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">stop</span><span style="color: #0000FF;">+</span><span style="color: #7060A8;">body</span><span style="color: #0000FF;">+</span><span style="color: #000000;">stail</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">tk_lt</span><span style="color: #0000FF;">:</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">tk_le</span><span style="color: #0000FF;">:</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">tk_ne</span><span style="color: #0000FF;">:</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">tk_eq</span><span style="color: #0000FF;">:</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">tk_gt</span><span style="color: #0000FF;">:</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">tk_ge</span><span style="color: #0000FF;">:</span>
<span style="color: #000000;">size</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">gen_size</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">[</span><span style="color: #000000;">2</span><span style="color: #0000FF;">])</span>
<span style="color: #000000;">size</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">gen_size</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">[</span><span style="color: #000000;">3</span><span style="color: #0000FF;">])</span>
<span style="color: #000000;">size</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">10</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">tk_and</span><span style="color: #0000FF;">:</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">tk_or</span><span style="color: #0000FF;">:</span>
<span style="color: #000000;">size</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">gen_size</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">[</span><span style="color: #000000;">2</span><span style="color: #0000FF;">])</span>
<span style="color: #000000;">size</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">gen_size</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">[</span><span style="color: #000000;">3</span><span style="color: #0000FF;">])</span>
<span style="color: #000000;">size</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">15</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">tk_add</span><span style="color: #0000FF;">:</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">tk_sub</span><span style="color: #0000FF;">:</span>
<span style="color: #000000;">size</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">gen_size</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">[</span><span style="color: #000000;">2</span><span style="color: #0000FF;">])</span>
<span style="color: #000000;">size</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">gen_size</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">[</span><span style="color: #000000;">3</span><span style="color: #0000FF;">])</span>
<span style="color: #000000;">size</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">4</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">tk_mul</span><span style="color: #0000FF;">:</span>
<span style="color: #000000;">size</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">gen_size</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">[</span><span style="color: #000000;">2</span><span style="color: #0000FF;">])</span>
<span style="color: #000000;">size</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">gen_size</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">[</span><span style="color: #000000;">3</span><span style="color: #0000FF;">])</span>
<span style="color: #000000;">size</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">5</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">tk_div</span><span style="color: #0000FF;">:</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">tk_mod</span><span style="color: #0000FF;">:</span>
<span style="color: #000000;">size</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">gen_size</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">[</span><span style="color: #000000;">2</span><span style="color: #0000FF;">])</span>
<span style="color: #000000;">size</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">gen_size</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">[</span><span style="color: #000000;">3</span><span style="color: #0000FF;">])</span>
<span style="color: #000000;">size</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">6</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">tk_putc</span><span style="color: #0000FF;">:</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">tk_Printi</span><span style="color: #0000FF;">:</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">tk_Prints</span><span style="color: #0000FF;">:</span>
<span style="color: #000000;">size</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">gen_size</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">[</span><span style="color: #000000;">2</span><span style="color: #0000FF;">])</span>
<span style="color: #000000;">size</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">5</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">tk_if</span><span style="color: #0000FF;">:</span>
<span style="color: #000000;">size</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">gen_size</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">[</span><span style="color: #000000;">2</span><span style="color: #0000FF;">])+</span><span style="color: #000000;">3</span>
<span style="color: #008080;">if</span> <span style="color: #000000;">t</span><span style="color: #0000FF;">[</span><span style="color: #000000;">3</span><span style="color: #0000FF;">][</span><span style="color: #000000;">1</span><span style="color: #0000FF;">]!=</span><span style="color: #000000;">tk_if</span> <span style="color: #008080;">then</span> <span style="color: #0000FF;">?</span><span style="color: #000000;">9</span><span style="color: #0000FF;">/</span><span style="color: #000000;">0</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">truesize</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">gen_size</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">[</span><span style="color: #000000;">3</span><span style="color: #0000FF;">][</span><span style="color: #000000;">2</span><span style="color: #0000FF;">])</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">falsesize</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">gen_size</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">[</span><span style="color: #000000;">3</span><span style="color: #0000FF;">][</span><span style="color: #000000;">3</span><span style="color: #0000FF;">])</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">elsejmp</span> <span style="color: #0000FF;">=</span> <span style="color: #008080;">iff</span><span style="color: #0000FF;">(</span><span style="color: #000000;">falsesize</span><span style="color: #0000FF;">=</span><span style="color: #000000;">0</span><span style="color: #0000FF;">?</span><span style="color: #000000;">0</span><span style="color: #0000FF;">:</span><span style="color: #008080;">iff</span><span style="color: #0000FF;">(</span><span style="color: #000000;">falsesize</span><span style="color: #0000FF;">></span><span style="color: #000000;">127</span><span style="color: #0000FF;">?</span><span style="color: #000000;">5</span><span style="color: #0000FF;">:</span><span style="color: #000000;">2</span><span style="color: #0000FF;">))</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">mainjmp</span> <span style="color: #0000FF;">=</span> <span style="color: #008080;">iff</span><span style="color: #0000FF;">(</span><span style="color: #000000;">truesize</span><span style="color: #0000FF;">+</span><span style="color: #000000;">elsejmp</span><span style="color: #0000FF;">></span><span style="color: #000000;">127</span><span style="color: #0000FF;">?</span><span style="color: #000000;">6</span><span style="color: #0000FF;">:</span><span style="color: #000000;">2</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">size</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">mainjmp</span><span style="color: #0000FF;">+</span><span style="color: #000000;">truesize</span><span style="color: #0000FF;">+</span><span style="color: #000000;">elsejmp</span><span style="color: #0000FF;">+</span><span style="color: #000000;">falsesize</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">tk_not</span><span style="color: #0000FF;">:</span>
<span style="color: #000000;">size</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">gen_size</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">[</span><span style="color: #000000;">2</span><span style="color: #0000FF;">])</span>
<span style="color: #000000;">size</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">9</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">tk_neg</span><span style="color: #0000FF;">:</span>
<span style="color: #000000;">size</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">gen_size</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">[</span><span style="color: #000000;">2</span><span style="color: #0000FF;">])</span>
<span style="color: #000000;">size</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">4</span>
<span style="color: #008080;">else</span><span style="color: #0000FF;">:</span>
<span style="color: #0000FF;">?</span><span style="color: #000000;">9</span><span style="color: #0000FF;">/</span><span style="color: #000000;">0</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">switch</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #008080;">return</span> <span style="color: #000000;">size</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">function</span>
<span style="color: #008080;">procedure</span> <span style="color: #000000;">gen_rec</span><span style="color: #0000FF;">(</span><span style="color: #004080;">object</span> <span style="color: #000000;">t</span><span style="color: #0000FF;">)</span>
<span style="color: #000080;font-style:italic;">-- the recursive part of code_gen</span>
<span style="color: #008080;">if</span> <span style="color: #000000;">t</span><span style="color: #0000FF;">!=</span><span style="color: #004600;">NULL</span> <span style="color: #008080;">then</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">initsize</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">code</span><span style="color: #0000FF;">)</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">estsize</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">gen_size</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">)</span> <span style="color: #000080;font-style:italic;">-- (test the gen_size function)</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">n_type</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">t</span><span style="color: #0000FF;">[</span><span style="color: #000000;">1</span><span style="color: #0000FF;">]</span>
<span style="color: #004080;">string</span> <span style="color: #000000;">node_type</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">tkNames</span><span style="color: #0000FF;">[</span><span style="color: #000000;">n_type</span><span style="color: #0000FF;">]</span>
<span style="color: #008080;">switch</span> <span style="color: #000000;">n_type</span> <span style="color: #008080;">do</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">tk_Sequence</span><span style="color: #0000FF;">:</span>
<span style="color: #000000;">gen_rec</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">[</span><span style="color: #000000;">2</span><span style="color: #0000FF;">])</span>
<span style="color: #000000;">gen_rec</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">[</span><span style="color: #000000;">3</span><span style="color: #0000FF;">])</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">tk_assign</span><span style="color: #0000FF;">:</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">n</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">var_idx</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">[</span><span style="color: #000000;">2</span><span style="color: #0000FF;">])</span>
<span style="color: #000000;">gen_rec</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">[</span><span style="color: #000000;">3</span><span style="color: #0000FF;">])</span>
<span style="color: #000000;">code</span> <span style="color: #0000FF;">&=</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">0o217</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0o005</span><span style="color: #0000FF;">,</span><span style="color: #000000;">chain</span><span style="color: #0000FF;">,</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #000000;">n</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0</span><span style="color: #0000FF;">}</span> <span style="color: #000080;font-style:italic;">-- pop [i]</span>
<span style="color: #000000;">chain</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">code</span><span style="color: #0000FF;">)-</span><span style="color: #000000;">3</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">tk_Integer</span><span style="color: #0000FF;">:</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">n</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">t</span><span style="color: #0000FF;">[</span><span style="color: #000000;">2</span><span style="color: #0000FF;">]</span>
<span style="color: #000000;">code</span> <span style="color: #0000FF;">&=</span> <span style="color: #000000;">0o150</span><span style="color: #0000FF;">&</span><span style="color: #7060A8;">int_to_bytes</span><span style="color: #0000FF;">(</span><span style="color: #000000;">n</span><span style="color: #0000FF;">)</span> <span style="color: #000080;font-style:italic;">-- push imm32</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">tk_while</span><span style="color: #0000FF;">:</span>
<span style="color: #000080;font-style:italic;">-- emit: @@:&lt;condition&gt;&lt;topjmp(@f)&gt;&lt;body&gt;&lt;tailjmp(@b)&gt;@@:</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">looptop</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">code</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">gen_rec</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">[</span><span style="color: #000000;">2</span><span style="color: #0000FF;">])</span>
<span style="color: #000000;">code</span> <span style="color: #0000FF;">&=</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">0o130</span><span style="color: #0000FF;">,</span> <span style="color: #000080;font-style:italic;">-- pop eax</span>
<span style="color: #000000;">0o205</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0o300</span><span style="color: #0000FF;">}</span> <span style="color: #000080;font-style:italic;">-- test eax,eax</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">bodysize</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">gen_size</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">[</span><span style="color: #000000;">3</span><span style="color: #0000FF;">])</span>
<span style="color: #000080;font-style:italic;">-- can we use short jumps?
-- disclaimer: size calcs are not heavily tested; if in
-- doubt reduce 128/7 by 8, and if that works
-- then yep, you just found a boundary case.</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">stail</span> <span style="color: #0000FF;">=</span> <span style="color: #008080;">iff</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">code</span><span style="color: #0000FF;">)+</span><span style="color: #000000;">bodysize</span><span style="color: #0000FF;">+</span><span style="color: #000000;">4</span><span style="color: #0000FF;">-</span><span style="color: #000000;">looptop</span><span style="color: #0000FF;">></span><span style="color: #000000;">128</span><span style="color: #0000FF;">?</span><span style="color: #000000;">5</span><span style="color: #0000FF;">:</span><span style="color: #000000;">2</span><span style="color: #0000FF;">)</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">offset</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">bodysize</span><span style="color: #0000FF;">+</span><span style="color: #000000;">stail</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">stop</span> <span style="color: #0000FF;">=</span> <span style="color: #008080;">iff</span><span style="color: #0000FF;">(</span><span style="color: #000000;">offset</span><span style="color: #0000FF;">></span><span style="color: #000000;">127</span><span style="color: #0000FF;">?</span><span style="color: #000000;">6</span><span style="color: #0000FF;">:</span><span style="color: #000000;">2</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">if</span> <span style="color: #000000;">stop</span><span style="color: #0000FF;">=</span><span style="color: #000000;">2</span> <span style="color: #008080;">then</span>
<span style="color: #000000;">code</span> <span style="color: #0000FF;">&=</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">0o164</span><span style="color: #0000FF;">,</span><span style="color: #000000;">offset</span><span style="color: #0000FF;">}</span> <span style="color: #000080;font-style:italic;">-- jz (short) end</span>
<span style="color: #008080;">else</span>
<span style="color: #000000;">code</span> <span style="color: #0000FF;">&=</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">0o017</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0o204</span><span style="color: #0000FF;">}&</span><span style="color: #7060A8;">int_to_bytes</span><span style="color: #0000FF;">(</span><span style="color: #000000;">offset</span><span style="color: #0000FF;">)</span> <span style="color: #000080;font-style:italic;">-- jz (long) end</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #000000;">gen_rec</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">[</span><span style="color: #000000;">3</span><span style="color: #0000FF;">])</span>
<span style="color: #000000;">offset</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">looptop</span><span style="color: #0000FF;">-(</span><span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">code</span><span style="color: #0000FF;">)+</span><span style="color: #000000;">stail</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">if</span> <span style="color: #000000;">stail</span><span style="color: #0000FF;">=</span><span style="color: #000000;">2</span> <span style="color: #008080;">then</span>
<span style="color: #000000;">code</span> <span style="color: #0000FF;">&=</span> <span style="color: #000000;">0o353</span><span style="color: #0000FF;">&</span><span style="color: #000000;">offset</span> <span style="color: #000080;font-style:italic;">-- jmp looptop (short)</span>
<span style="color: #008080;">else</span>
<span style="color: #000000;">code</span> <span style="color: #0000FF;">&=</span> <span style="color: #000000;">0o351</span><span style="color: #0000FF;">&</span><span style="color: #7060A8;">int_to_bytes</span><span style="color: #0000FF;">(</span><span style="color: #000000;">offset</span><span style="color: #0000FF;">)</span> <span style="color: #000080;font-style:italic;">-- jmp looptop (long)</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">tk_lt</span><span style="color: #0000FF;">:</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">tk_le</span><span style="color: #0000FF;">:</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">tk_gt</span><span style="color: #0000FF;">:</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">tk_ge</span><span style="color: #0000FF;">:</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">tk_ne</span><span style="color: #0000FF;">:</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">tk_eq</span><span style="color: #0000FF;">:</span>
<span style="color: #000000;">gen_rec</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">[</span><span style="color: #000000;">2</span><span style="color: #0000FF;">])</span>
<span style="color: #000000;">gen_rec</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">[</span><span style="color: #000000;">3</span><span style="color: #0000FF;">])</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">xrm</span>
<span style="color: #008080;">if</span> <span style="color: #000000;">n_type</span><span style="color: #0000FF;">=</span><span style="color: #000000;">tk_ne</span> <span style="color: #008080;">then</span> <span style="color: #000000;">xrm</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">0o225</span> <span style="color: #000080;font-style:italic;">-- (#95)</span>
<span style="color: #008080;">elsif</span> <span style="color: #000000;">n_type</span><span style="color: #0000FF;">=</span><span style="color: #000000;">tk_lt</span> <span style="color: #008080;">then</span> <span style="color: #000000;">xrm</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">0o234</span> <span style="color: #000080;font-style:italic;">-- (#9C)</span>
<span style="color: #008080;">elsif</span> <span style="color: #000000;">n_type</span><span style="color: #0000FF;">=</span><span style="color: #000000;">tk_ge</span> <span style="color: #008080;">then</span> <span style="color: #000000;">xrm</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">0o235</span> <span style="color: #000080;font-style:italic;">-- (#9D)</span>
<span style="color: #008080;">elsif</span> <span style="color: #000000;">n_type</span><span style="color: #0000FF;">=</span><span style="color: #000000;">tk_le</span> <span style="color: #008080;">then</span> <span style="color: #000000;">xrm</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">0o236</span> <span style="color: #000080;font-style:italic;">-- (#9E)</span>
<span style="color: #008080;">elsif</span> <span style="color: #000000;">n_type</span><span style="color: #0000FF;">=</span><span style="color: #000000;">tk_gt</span> <span style="color: #008080;">then</span> <span style="color: #000000;">xrm</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">0o237</span> <span style="color: #000080;font-style:italic;">-- (#9F)</span>
<span style="color: #008080;">else</span> <span style="color: #0000FF;">?</span><span style="color: #000000;">9</span><span style="color: #0000FF;">/</span><span style="color: #000000;">0</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #000000;">code</span> <span style="color: #0000FF;">&=</span> <span style="color: #0000FF;">{</span> <span style="color: #000000;">0o061</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0o300</span><span style="color: #0000FF;">,</span> <span style="color: #000080;font-style:italic;">-- xor eax,eax</span>
<span style="color: #000000;">0o132</span><span style="color: #0000FF;">,</span> <span style="color: #000080;font-style:italic;">-- pop edx</span>
<span style="color: #000000;">0o131</span><span style="color: #0000FF;">,</span> <span style="color: #000080;font-style:italic;">-- pop ecx</span>
<span style="color: #000000;">0o071</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0o321</span><span style="color: #0000FF;">,</span> <span style="color: #000080;font-style:italic;">-- cmp ecx,edx</span>
<span style="color: #000000;">0o017</span><span style="color: #0000FF;">,</span><span style="color: #000000;">xrm</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0o300</span><span style="color: #0000FF;">,</span> <span style="color: #000080;font-style:italic;">-- setcc al</span>
<span style="color: #000000;">0o120</span><span style="color: #0000FF;">}</span> <span style="color: #000080;font-style:italic;">-- push eax</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">tk_or</span><span style="color: #0000FF;">:</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">tk_and</span><span style="color: #0000FF;">:</span>
<span style="color: #000000;">gen_rec</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">[</span><span style="color: #000000;">2</span><span style="color: #0000FF;">])</span>
<span style="color: #000000;">gen_rec</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">[</span><span style="color: #000000;">3</span><span style="color: #0000FF;">])</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">op</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">find</span><span style="color: #0000FF;">(</span><span style="color: #000000;">n_type</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">tk_or</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0</span><span style="color: #0000FF;">,</span><span style="color: #000000;">tk_and</span><span style="color: #0000FF;">})</span>
<span style="color: #000000;">op</span> <span style="color: #0000FF;">*=</span> <span style="color: #000000;">0o010</span>
<span style="color: #000000;">code</span> <span style="color: #0000FF;">&=</span> <span style="color: #0000FF;">{</span> <span style="color: #000000;">0o130</span><span style="color: #0000FF;">,</span> <span style="color: #000080;font-style:italic;">-- pop eax</span>
<span style="color: #000000;">0o131</span><span style="color: #0000FF;">,</span> <span style="color: #000080;font-style:italic;">-- pop ecx</span>
<span style="color: #000000;">0o205</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0o300</span><span style="color: #0000FF;">,</span> <span style="color: #000080;font-style:italic;">-- test eax,eax</span>
<span style="color: #000000;">0o017</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0o225</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0o300</span><span style="color: #0000FF;">,</span> <span style="color: #000080;font-style:italic;">-- setne al</span>
<span style="color: #000000;">0o205</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0o311</span><span style="color: #0000FF;">,</span> <span style="color: #000080;font-style:italic;">-- test ecx,ecx</span>
<span style="color: #000000;">0o017</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0o225</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0o301</span><span style="color: #0000FF;">,</span> <span style="color: #000080;font-style:italic;">-- setne cl</span>
<span style="color: #000000;">op</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0o310</span><span style="color: #0000FF;">,</span> <span style="color: #000080;font-style:italic;">-- or/and al,cl</span>
<span style="color: #000000;">0o120</span><span style="color: #0000FF;">}</span> <span style="color: #000080;font-style:italic;">-- push eax</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">tk_add</span><span style="color: #0000FF;">:</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">tk_sub</span><span style="color: #0000FF;">:</span>
<span style="color: #000000;">gen_rec</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">[</span><span style="color: #000000;">2</span><span style="color: #0000FF;">])</span>
<span style="color: #000000;">gen_rec</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">[</span><span style="color: #000000;">3</span><span style="color: #0000FF;">])</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">op</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">find</span><span style="color: #0000FF;">(</span><span style="color: #000000;">n_type</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">tk_add</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0</span><span style="color: #0000FF;">,</span><span style="color: #000000;">tk_sub</span><span style="color: #0000FF;">})</span>
<span style="color: #000000;">op</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">0o001</span> <span style="color: #0000FF;">+</span> <span style="color: #0000FF;">(</span><span style="color: #000000;">op</span><span style="color: #0000FF;">-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">)*</span><span style="color: #000000;">0o010</span>
<span style="color: #000000;">code</span> <span style="color: #0000FF;">&=</span> <span style="color: #0000FF;">{</span> <span style="color: #000000;">0o130</span><span style="color: #0000FF;">,</span> <span style="color: #000080;font-style:italic;">-- pop eax</span>
<span style="color: #000000;">op</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0o004</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0o044</span><span style="color: #0000FF;">}</span> <span style="color: #000080;font-style:italic;">-- add/or/and/sub [esp],eax</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">tk_mul</span><span style="color: #0000FF;">:</span>
<span style="color: #000000;">gen_rec</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">[</span><span style="color: #000000;">2</span><span style="color: #0000FF;">])</span>
<span style="color: #000000;">gen_rec</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">[</span><span style="color: #000000;">3</span><span style="color: #0000FF;">])</span>
<span style="color: #000000;">code</span> <span style="color: #0000FF;">&=</span> <span style="color: #0000FF;">{</span> <span style="color: #000000;">0o131</span><span style="color: #0000FF;">,</span> <span style="color: #000080;font-style:italic;">-- pop ecx</span>
<span style="color: #000000;">0o130</span><span style="color: #0000FF;">,</span> <span style="color: #000080;font-style:italic;">-- pop eax</span>
<span style="color: #000000;">0o367</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0o341</span><span style="color: #0000FF;">,</span> <span style="color: #000080;font-style:italic;">-- mul ecx</span>
<span style="color: #000000;">0o120</span><span style="color: #0000FF;">}</span> <span style="color: #000080;font-style:italic;">-- push eax</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">tk_div</span><span style="color: #0000FF;">:</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">tk_mod</span><span style="color: #0000FF;">:</span>
<span style="color: #000000;">gen_rec</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">[</span><span style="color: #000000;">2</span><span style="color: #0000FF;">])</span>
<span style="color: #000000;">gen_rec</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">[</span><span style="color: #000000;">3</span><span style="color: #0000FF;">])</span>
<span style="color: #004080;">integer</span> <span style="color: #7060A8;">push</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">0o120</span><span style="color: #0000FF;">+(</span><span style="color: #000000;">n_type</span><span style="color: #0000FF;">=</span><span style="color: #000000;">tk_mod</span><span style="color: #0000FF;">)*</span><span style="color: #000000;">2</span>
<span style="color: #000000;">code</span> <span style="color: #0000FF;">&=</span> <span style="color: #0000FF;">{</span> <span style="color: #000000;">0o131</span><span style="color: #0000FF;">,</span> <span style="color: #000080;font-style:italic;">-- pop ecx</span>
<span style="color: #000000;">0o130</span><span style="color: #0000FF;">,</span> <span style="color: #000080;font-style:italic;">-- pop eax</span>
<span style="color: #000000;">0o231</span><span style="color: #0000FF;">,</span> <span style="color: #000080;font-style:italic;">-- cdq (eax -&gt; edx:eax)</span>
<span style="color: #000000;">0o367</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0o371</span><span style="color: #0000FF;">,</span> <span style="color: #000080;font-style:italic;">-- idiv ecx</span>
<span style="color: #7060A8;">push</span><span style="color: #0000FF;">}</span> <span style="color: #000080;font-style:italic;">-- push eax|edx</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">tk_Identifier</span><span style="color: #0000FF;">:</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">n</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">var_idx</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">code</span> <span style="color: #0000FF;">&=</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">0o377</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0o065</span><span style="color: #0000FF;">,</span><span style="color: #000000;">chain</span><span style="color: #0000FF;">,</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #000000;">n</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0</span><span style="color: #0000FF;">}</span> <span style="color: #000080;font-style:italic;">-- push [n]</span>
<span style="color: #000000;">chain</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">code</span><span style="color: #0000FF;">)-</span><span style="color: #000000;">3</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">tk_putc</span><span style="color: #0000FF;">:</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">tk_Printi</span><span style="color: #0000FF;">:</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">tk_Prints</span><span style="color: #0000FF;">:</span>
<span style="color: #000000;">gen_rec</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">[</span><span style="color: #000000;">2</span><span style="color: #0000FF;">])</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">n</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">find</span><span style="color: #0000FF;">(</span><span style="color: #000000;">n_type</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">tk_putc</span><span style="color: #0000FF;">,</span><span style="color: #000000;">tk_Printi</span><span style="color: #0000FF;">,</span><span style="color: #000000;">tk_Prints</span><span style="color: #0000FF;">})</span>
<span style="color: #000000;">code</span> <span style="color: #0000FF;">&=</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">0o350</span><span style="color: #0000FF;">,</span><span style="color: #000000;">chain</span><span style="color: #0000FF;">,</span><span style="color: #000000;">3</span><span style="color: #0000FF;">,</span><span style="color: #000000;">n</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0</span><span style="color: #0000FF;">}</span> <span style="color: #000080;font-style:italic;">-- call :printc/i/s</span>
<span style="color: #000000;">chain</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">code</span><span style="color: #0000FF;">)-</span><span style="color: #000000;">3</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">tk_String</span><span style="color: #0000FF;">:</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">n</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">string_idx</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">code</span> <span style="color: #0000FF;">&=</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">0o150</span><span style="color: #0000FF;">,</span><span style="color: #000000;">chain</span><span style="color: #0000FF;">,</span><span style="color: #000000;">2</span><span style="color: #0000FF;">,</span><span style="color: #000000;">n</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0</span><span style="color: #0000FF;">}</span> <span style="color: #000080;font-style:italic;">-- push RawStringPtr(string)</span>
<span style="color: #000000;">chain</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">code</span><span style="color: #0000FF;">)-</span><span style="color: #000000;">3</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">tk_if</span><span style="color: #0000FF;">:</span>
<span style="color: #000080;font-style:italic;">-- emit: &lt;condition&gt;&lt;mainjmp&gt;&lt;truepart&gt;[&lt;elsejmp&gt;&lt;falsepart&gt;]</span>
<span style="color: #000000;">gen_rec</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">[</span><span style="color: #000000;">2</span><span style="color: #0000FF;">])</span>
<span style="color: #000000;">code</span> <span style="color: #0000FF;">&=</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">0o130</span><span style="color: #0000FF;">,</span> <span style="color: #000080;font-style:italic;">-- pop eax</span>
<span style="color: #000000;">0o205</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0o300</span><span style="color: #0000FF;">}</span> <span style="color: #000080;font-style:italic;">-- test eax,eax</span>
<span style="color: #008080;">if</span> <span style="color: #000000;">t</span><span style="color: #0000FF;">[</span><span style="color: #000000;">3</span><span style="color: #0000FF;">][</span><span style="color: #000000;">1</span><span style="color: #0000FF;">]!=</span><span style="color: #000000;">tk_if</span> <span style="color: #008080;">then</span> <span style="color: #0000FF;">?</span><span style="color: #000000;">9</span><span style="color: #0000FF;">/</span><span style="color: #000000;">0</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">truesize</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">gen_size</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">[</span><span style="color: #000000;">3</span><span style="color: #0000FF;">][</span><span style="color: #000000;">2</span><span style="color: #0000FF;">])</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">falsesize</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">gen_size</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">[</span><span style="color: #000000;">3</span><span style="color: #0000FF;">][</span><span style="color: #000000;">3</span><span style="color: #0000FF;">])</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">elsejmp</span> <span style="color: #0000FF;">=</span> <span style="color: #008080;">iff</span><span style="color: #0000FF;">(</span><span style="color: #000000;">falsesize</span><span style="color: #0000FF;">=</span><span style="color: #000000;">0</span><span style="color: #0000FF;">?</span><span style="color: #000000;">0</span><span style="color: #0000FF;">:</span><span style="color: #008080;">iff</span><span style="color: #0000FF;">(</span><span style="color: #000000;">falsesize</span><span style="color: #0000FF;">></span><span style="color: #000000;">127</span><span style="color: #0000FF;">?</span><span style="color: #000000;">5</span><span style="color: #0000FF;">:</span><span style="color: #000000;">2</span><span style="color: #0000FF;">))</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">offset</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">truesize</span><span style="color: #0000FF;">+</span><span style="color: #000000;">elsejmp</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">mainjmp</span> <span style="color: #0000FF;">=</span> <span style="color: #008080;">iff</span><span style="color: #0000FF;">(</span><span style="color: #000000;">offset</span><span style="color: #0000FF;">></span><span style="color: #000000;">127</span><span style="color: #0000FF;">?</span><span style="color: #000000;">6</span><span style="color: #0000FF;">:</span><span style="color: #000000;">2</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">if</span> <span style="color: #000000;">mainjmp</span><span style="color: #0000FF;">=</span><span style="color: #000000;">2</span> <span style="color: #008080;">then</span>
<span style="color: #000000;">code</span> <span style="color: #0000FF;">&=</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">0o164</span><span style="color: #0000FF;">,</span><span style="color: #000000;">offset</span><span style="color: #0000FF;">}</span> <span style="color: #000080;font-style:italic;">-- jz (short) else/end</span>
<span style="color: #008080;">else</span>
<span style="color: #000000;">code</span> <span style="color: #0000FF;">&=</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">0o017</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0o204</span><span style="color: #0000FF;">}&</span><span style="color: #7060A8;">int_to_bytes</span><span style="color: #0000FF;">(</span><span style="color: #000000;">offset</span><span style="color: #0000FF;">)</span> <span style="color: #000080;font-style:italic;">-- jz (long) else/end</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #000000;">gen_rec</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">[</span><span style="color: #000000;">3</span><span style="color: #0000FF;">][</span><span style="color: #000000;">2</span><span style="color: #0000FF;">])</span>
<span style="color: #008080;">if</span> <span style="color: #000000;">falsesize</span><span style="color: #0000FF;">!=</span><span style="color: #000000;">0</span> <span style="color: #008080;">then</span>
<span style="color: #000000;">offset</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">falsesize</span>
<span style="color: #008080;">if</span> <span style="color: #000000;">elsejmp</span><span style="color: #0000FF;">=</span><span style="color: #000000;">2</span> <span style="color: #008080;">then</span>
<span style="color: #000000;">code</span> <span style="color: #0000FF;">&=</span> <span style="color: #000000;">0o353</span><span style="color: #0000FF;">&</span><span style="color: #000000;">offset</span> <span style="color: #000080;font-style:italic;">-- jmp end if (short)</span>
<span style="color: #008080;">else</span>
<span style="color: #000000;">code</span> <span style="color: #0000FF;">&=</span> <span style="color: #000000;">0o351</span><span style="color: #0000FF;">&</span><span style="color: #7060A8;">int_to_bytes</span><span style="color: #0000FF;">(</span><span style="color: #000000;">offset</span><span style="color: #0000FF;">)</span> <span style="color: #000080;font-style:italic;">-- jmp end if (long)</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #000000;">gen_rec</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">[</span><span style="color: #000000;">3</span><span style="color: #0000FF;">][</span><span style="color: #000000;">3</span><span style="color: #0000FF;">])</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">tk_not</span><span style="color: #0000FF;">:</span>
<span style="color: #000000;">gen_rec</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">[</span><span style="color: #000000;">2</span><span style="color: #0000FF;">])</span>
<span style="color: #000000;">code</span> <span style="color: #0000FF;">&=</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">0o132</span><span style="color: #0000FF;">,</span> <span style="color: #000080;font-style:italic;">-- pop edx</span>
<span style="color: #000000;">0o061</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0o300</span><span style="color: #0000FF;">,</span> <span style="color: #000080;font-style:italic;">-- xor eax,eax</span>
<span style="color: #000000;">0o205</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0o322</span><span style="color: #0000FF;">,</span> <span style="color: #000080;font-style:italic;">-- test edx,edx</span>
<span style="color: #000000;">0o017</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0o224</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0o300</span><span style="color: #0000FF;">,</span> <span style="color: #000080;font-style:italic;">-- setz al</span>
<span style="color: #000000;">0o120</span><span style="color: #0000FF;">}</span> <span style="color: #000080;font-style:italic;">-- push eax</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">tk_neg</span><span style="color: #0000FF;">:</span>
<span style="color: #000000;">gen_rec</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">[</span><span style="color: #000000;">2</span><span style="color: #0000FF;">])</span>
<span style="color: #000000;">code</span> <span style="color: #0000FF;">&=</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">0o130</span><span style="color: #0000FF;">,</span> <span style="color: #000080;font-style:italic;">-- pop eax</span>
<span style="color: #000000;">0o367</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0o330</span><span style="color: #0000FF;">,</span> <span style="color: #000080;font-style:italic;">-- neg eax</span>
<span style="color: #000000;">0o120</span><span style="color: #0000FF;">}</span> <span style="color: #000080;font-style:italic;">-- push eax</span>
<span style="color: #008080;">else</span><span style="color: #0000FF;">:</span>
<span style="color: #000000;">error</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"error in code generator - found %d, expecting operator\n"</span><span style="color: #0000FF;">,</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">n_type</span><span style="color: #0000FF;">})</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">switch</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">actsize</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">code</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">if</span> <span style="color: #000000;">initsize</span><span style="color: #0000FF;">+</span><span style="color: #000000;">estsize</span><span style="color: #0000FF;">!=</span><span style="color: #000000;">actsize</span> <span style="color: #008080;">then</span> <span style="color: #0000FF;">?</span><span style="color: #008000;">"9/0"</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span> <span style="color: #000080;font-style:italic;">-- (test gen_size)</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">procedure</span>
<span style="color: #008080;">global</span> <span style="color: #008080;">procedure</span> <span style="color: #000000;">code_gen</span><span style="color: #0000FF;">(</span><span style="color: #004080;">object</span> <span style="color: #000000;">t</span><span style="color: #0000FF;">)</span>
<span style="color: #000080;font-style:italic;">--
-- Generates proper machine code.
--
-- Example: i=10; print "\n"; print i; print "\n"
-- Result in vars, strings, chain, code (declared above)
-- where vars is: {"i"},
-- strings is {"\n"},
-- code is { 0o150,#0A,#00,#00,#00, -- 1: push 10
-- 0o217,0o005,0,1,1,0 -- 6: pop [i]
-- 0o150,8,2,1,0, -- 12: push ("\n")
-- 0o350,13,3,3,0, -- 17: call :prints
-- 0o377,0o065,18,1,1,0, -- 22: push [i]
-- 0o350,24,3,2,0, -- 28: call :printi
-- 0o150,29,2,1,0, -- 33: push ("\n")
-- 0o350,34,3,3,0, -- 38: call :prints
-- 0o303} -- 43: ret
-- and chain is 39 (-&gt;34-&gt;29-&gt;24-&gt;18-&gt;13-&gt;8-&gt;0)
-- The chain connects all places where we need an actual address before
-- the code is executed, with the byte after the link differentiating
-- between var(1), string(2), and builtin(3), and the byte after that
-- determining the instance of the given type - not that any of them
-- are actually limited to a byte in the above intermediate form, and
-- of course the trailing 0 of each {link,type,id,0} is just there to
-- reserve the space we will need.
--</span>
<span style="color: #000000;">gen_rec</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">code</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">append</span><span style="color: #0000FF;">(</span><span style="color: #000000;">code</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0o303</span><span style="color: #0000FF;">)</span> <span style="color: #000080;font-style:italic;">-- ret (0o303=#C3)</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">procedure</span>
<span style="color: #008080;">include</span> <span style="color: #000000;">builtins</span><span style="color: #0000FF;">/</span><span style="color: #000000;">VM</span><span style="color: #0000FF;">/</span><span style="color: #000000;">puts1</span><span style="color: #0000FF;">.</span><span style="color: #000000;">e</span> <span style="color: #000080;font-style:italic;">-- low-level console i/o routines</span>
<span style="color: #008080;">function</span> <span style="color: #000000;">setbuiltins</span><span style="color: #0000FF;">()</span>
<span style="color: #004080;">atom</span> <span style="color: #000000;">printc</span><span style="color: #0000FF;">,</span><span style="color: #000000;">printi</span><span style="color: #0000FF;">,</span><span style="color: #000000;">prints</span>
#ilASM{
jmp :setbuiltins
::printc
lea edi,[esp+4]
mov esi,1
call :%puts1ediesi -- (edi=raw text, esi=length)
ret 4
::printi
mov eax,[esp+4]
push 0 -- no cr
call :%putsint -- (nb limited to +/-9,999,999,999)
ret 4
::prints
mov edi,[esp+4]
mov esi,[edi-12]
call :%puts1ediesi -- (edi=raw text, esi=length)
ret 4
::setbuiltins
mov eax,:printc
lea edi,[printc]
call :%pStoreMint
mov eax,:printi
lea edi,[printi]
call :%pStoreMint
mov eax,:prints
lea edi,[prints]
call :%pStoreMint
}
<span style="color: #008080;">return</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">printc</span><span style="color: #0000FF;">,</span><span style="color: #000000;">printi</span><span style="color: #0000FF;">,</span><span style="color: #000000;">prints</span><span style="color: #0000FF;">}</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">function</span>
<span style="color: #008080;">global</span> <span style="color: #008080;">constant</span> <span style="color: #000000;">builtin_names</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{</span><span style="color: #008000;">"printc"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"printi"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"prints"</span><span style="color: #0000FF;">}</span>
<span style="color: #008080;">global</span> <span style="color: #008080;">constant</span> <span style="color: #000000;">builtins</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">setbuiltins</span><span style="color: #0000FF;">()</span>
<span style="color: #008080;">global</span> <span style="color: #004080;">atom</span> <span style="color: #000000;">var_mem</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">code_mem</span>
<span style="color: #008080;">function</span> <span style="color: #000000;">RawStringPtr</span><span style="color: #0000FF;">(</span><span style="color: #004080;">integer</span> <span style="color: #000000;">n</span><span style="color: #0000FF;">)</span> <span style="color: #000080;font-style:italic;">-- (based on IupRawStringPtr from pGUI.e)
--
-- Returns a raw string pointer for s, somewhat like allocate_string(s), but using the existing memory.
-- NOTE: The return is only valid as long as the value passed as the parameter remains in existence.
--</span>
<span style="color: #004080;">atom</span> <span style="color: #000000;">res</span>
<span style="color: #004080;">string</span> <span style="color: #000000;">s</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">strings</span><span style="color: #0000FF;">[</span><span style="color: #000000;">n</span><span style="color: #0000FF;">]</span>
#ilASM{
mov eax,[s]
lea edi,[res]
shl eax,2
call :%pStoreMint
}
<span style="color: #000000;">stringptrs</span><span style="color: #0000FF;">[</span><span style="color: #000000;">n</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">res</span>
<span style="color: #008080;">return</span> <span style="color: #000000;">res</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">function</span>
<span style="color: #008080;">global</span> <span style="color: #008080;">procedure</span> <span style="color: #000000;">fixup</span><span style="color: #0000FF;">()</span>
<span style="color: #000000;">var_mem</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">allocate</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">vars</span><span style="color: #0000FF;">)*</span><span style="color: #000000;">4</span><span style="color: #0000FF;">)</span>
<span style="color: #7060A8;">mem_set</span><span style="color: #0000FF;">(</span><span style="color: #000000;">var_mem</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0</span><span style="color: #0000FF;">,</span><span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">vars</span><span style="color: #0000FF;">)*</span><span style="color: #000000;">4</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">code_mem</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">allocate</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">code</span><span style="color: #0000FF;">))</span>
<span style="color: #7060A8;">poke</span><span style="color: #0000FF;">(</span><span style="color: #000000;">code_mem</span><span style="color: #0000FF;">,</span><span style="color: #000000;">code</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">while</span> <span style="color: #000000;">chain</span><span style="color: #0000FF;">!=</span><span style="color: #000000;">0</span> <span style="color: #008080;">do</span>
<span style="color: #004080;">integer</span> <span style="color: #7060A8;">this</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">chain</span>
<span style="color: #000000;">chain</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">code</span><span style="color: #0000FF;">[</span><span style="color: #7060A8;">this</span><span style="color: #0000FF;">]</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">ftype</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">code</span><span style="color: #0000FF;">[</span><span style="color: #7060A8;">this</span><span style="color: #0000FF;">+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">]</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">id</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">code</span><span style="color: #0000FF;">[</span><span style="color: #7060A8;">this</span><span style="color: #0000FF;">+</span><span style="color: #000000;">2</span><span style="color: #0000FF;">]</span>
<span style="color: #008080;">switch</span> <span style="color: #000000;">ftype</span> <span style="color: #008080;">do</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">1</span><span style="color: #0000FF;">:</span> <span style="color: #000080;font-style:italic;">-- vars</span>
<span style="color: #7060A8;">poke4</span><span style="color: #0000FF;">(</span><span style="color: #000000;">code_mem</span><span style="color: #0000FF;">+</span><span style="color: #7060A8;">this</span><span style="color: #0000FF;">-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #000000;">var_mem</span><span style="color: #0000FF;">+(</span><span style="color: #000000;">id</span><span style="color: #0000FF;">-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">)*</span><span style="color: #000000;">4</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">2</span><span style="color: #0000FF;">:</span> <span style="color: #000080;font-style:italic;">-- strings</span>
<span style="color: #7060A8;">poke4</span><span style="color: #0000FF;">(</span><span style="color: #000000;">code_mem</span><span style="color: #0000FF;">+</span><span style="color: #7060A8;">this</span><span style="color: #0000FF;">-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #000000;">RawStringPtr</span><span style="color: #0000FF;">(</span><span style="color: #000000;">id</span><span style="color: #0000FF;">))</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">3</span><span style="color: #0000FF;">:</span> <span style="color: #000080;font-style:italic;">-- builtins</span>
<span style="color: #7060A8;">poke4</span><span style="color: #0000FF;">(</span><span style="color: #000000;">code_mem</span><span style="color: #0000FF;">+</span><span style="color: #7060A8;">this</span><span style="color: #0000FF;">-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #000000;">builtins</span><span style="color: #0000FF;">[</span><span style="color: #000000;">id</span><span style="color: #0000FF;">]-(</span><span style="color: #000000;">code_mem</span><span style="color: #0000FF;">+</span><span style="color: #7060A8;">this</span><span style="color: #0000FF;">+</span><span style="color: #000000;">3</span><span style="color: #0000FF;">))</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">switch</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">while</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">procedure</span>
<!--</syntaxhighlight>-->
And a simple test driver for the specific task:
<!--<syntaxhighlight lang="phix">(notonline)-->
<span style="color: #000080;font-style:italic;">--
-- demo\rosetta\Compiler\cgen.exw
-- ==============================
--
-- Generates 32-bit machine code (see note in vm.exw)
--</span>
<span style="color: #008080;">without</span> <span style="color: #008080;">js</span> <span style="color: #000080;font-style:italic;">-- (machine code!)</span>
<span style="color: #008080;">include</span> <span style="color: #000000;">cgen</span><span style="color: #0000FF;">.</span><span style="color: #000000;">e</span>
<span style="color: #008080;">function</span> <span style="color: #000000;">get_var_name</span><span style="color: #0000FF;">(</span><span style="color: #004080;">atom</span> <span style="color: #000000;">addr</span><span style="color: #0000FF;">)</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">n</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">(</span><span style="color: #000000;">addr</span><span style="color: #0000FF;">-</span><span style="color: #000000;">var_mem</span><span style="color: #0000FF;">)/</span><span style="color: #000000;">4</span><span style="color: #0000FF;">+</span><span style="color: #000000;">1</span>
<span style="color: #008080;">if</span> <span style="color: #000000;">n</span><span style="color: #0000FF;"><</span><span style="color: #000000;">1</span> <span style="color: #008080;">or</span> <span style="color: #000000;">n</span><span style="color: #0000FF;">></span><span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">vars</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">then</span> <span style="color: #0000FF;">?</span><span style="color: #000000;">9</span><span style="color: #0000FF;">/</span><span style="color: #000000;">0</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #008080;">return</span> <span style="color: #000000;">vars</span><span style="color: #0000FF;">[</span><span style="color: #000000;">n</span><span style="color: #0000FF;">]</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">function</span>
<span style="color: #008080;">function</span> <span style="color: #000000;">hxl</span><span style="color: #0000FF;">(</span><span style="color: #004080;">integer</span> <span style="color: #000000;">pc</span><span style="color: #0000FF;">,</span> <span style="color: #004080;">object</span> <span style="color: #000000;">oh</span><span style="color: #0000FF;">,</span> <span style="color: #004080;">string</span> <span style="color: #000000;">fmt</span><span style="color: #0000FF;">,</span> <span style="color: #004080;">sequence</span> <span style="color: #000000;">args</span><span style="color: #0000FF;">={})</span>
<span style="color: #000080;font-style:italic;">-- helper routine to display the octal/hex bytes just decoded,
-- along with the code offset and the human-readable text.</span>
<span style="color: #008080;">if</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">args</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">then</span> <span style="color: #000000;">fmt</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">sprintf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">fmt</span><span style="color: #0000FF;">,</span><span style="color: #000000;">args</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #004080;">sequence</span> <span style="color: #000000;">octhex</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{}</span>
<span style="color: #004080;">atom</span> <span style="color: #000000;">base</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">code_mem</span><span style="color: #0000FF;">+</span><span style="color: #000000;">pc</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">len</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">0</span>
<span style="color: #008080;">if</span> <span style="color: #004080;">integer</span><span style="color: #0000FF;">(</span><span style="color: #000000;">oh</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">then</span> <span style="color: #000080;font-style:italic;">-- all octal</span>
<span style="color: #008080;">for</span> <span style="color: #000000;">i</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #000000;">oh</span> <span style="color: #008080;">do</span>
<span style="color: #000000;">octhex</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">append</span><span style="color: #0000FF;">(</span><span style="color: #000000;">octhex</span><span style="color: #0000FF;">,</span><span style="color: #7060A8;">sprintf</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"0o%03o"</span><span style="color: #0000FF;">,</span><span style="color: #7060A8;">peek</span><span style="color: #0000FF;">(</span><span style="color: #000000;">base</span><span style="color: #0000FF;">)))</span>
<span style="color: #000000;">base</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">1</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
<span style="color: #000000;">len</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">oh</span>
<span style="color: #008080;">else</span> <span style="color: #000080;font-style:italic;">-- some octal and some hex</span>
<span style="color: #008080;">for</span> <span style="color: #000000;">i</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">oh</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">by</span> <span style="color: #000000;">2</span> <span style="color: #008080;">do</span>
<span style="color: #008080;">for</span> <span style="color: #000000;">j</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #000000;">oh</span><span style="color: #0000FF;">[</span><span style="color: #000000;">i</span><span style="color: #0000FF;">]</span> <span style="color: #008080;">do</span>
<span style="color: #000000;">octhex</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">append</span><span style="color: #0000FF;">(</span><span style="color: #000000;">octhex</span><span style="color: #0000FF;">,</span><span style="color: #7060A8;">sprintf</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"0o%03o"</span><span style="color: #0000FF;">,</span><span style="color: #7060A8;">peek</span><span style="color: #0000FF;">(</span><span style="color: #000000;">base</span><span style="color: #0000FF;">)))</span>
<span style="color: #000000;">base</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">1</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
<span style="color: #000000;">len</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">oh</span><span style="color: #0000FF;">[</span><span style="color: #000000;">i</span><span style="color: #0000FF;">]</span>
<span style="color: #008080;">for</span> <span style="color: #000000;">j</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #000000;">oh</span><span style="color: #0000FF;">[</span><span style="color: #000000;">i</span><span style="color: #0000FF;">+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">]</span> <span style="color: #008080;">do</span>
<span style="color: #000000;">octhex</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">append</span><span style="color: #0000FF;">(</span><span style="color: #000000;">octhex</span><span style="color: #0000FF;">,</span><span style="color: #7060A8;">sprintf</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"#%02x"</span><span style="color: #0000FF;">,</span><span style="color: #7060A8;">peek</span><span style="color: #0000FF;">(</span><span style="color: #000000;">base</span><span style="color: #0000FF;">)))</span>
<span style="color: #000000;">base</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">1</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
<span style="color: #000000;">len</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">oh</span><span style="color: #0000FF;">[</span><span style="color: #000000;">i</span><span style="color: #0000FF;">+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">]</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">output_file</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"%4d: %-30s %s\n"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">pc</span><span style="color: #0000FF;">+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #7060A8;">join</span><span style="color: #0000FF;">(</span><span style="color: #000000;">octhex</span><span style="color: #0000FF;">,</span><span style="color: #008000;">","</span><span style="color: #0000FF;">),</span><span style="color: #000000;">fmt</span><span style="color: #0000FF;">})</span>
<span style="color: #008080;">return</span> <span style="color: #000000;">len</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">function</span>
<span style="color: #008080;">constant</span> <span style="color: #000000;">cccodes</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{</span><span style="color: #008000;">"o?"</span> <span style="color: #0000FF;">,</span><span style="color: #008000;">"no?"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"b?"</span> <span style="color: #0000FF;">,</span><span style="color: #008000;">"ae?"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"z"</span> <span style="color: #0000FF;">,</span><span style="color: #008000;">"ne"</span> <span style="color: #0000FF;">,</span><span style="color: #008000;">"be?"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"a?"</span><span style="color: #0000FF;">,</span>
<span style="color: #000080;font-style:italic;">-- 0 , 1 , 2 , 3 , 4 , 5 , 6 , 7 ,</span>
<span style="color: #008000;">"s?"</span> <span style="color: #0000FF;">,</span><span style="color: #008000;">"ns?"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"pe?"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"po?"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"l"</span> <span style="color: #0000FF;">,</span><span style="color: #008000;">"ge"</span> <span style="color: #0000FF;">,</span><span style="color: #008000;">"le"</span> <span style="color: #0000FF;">,</span><span style="color: #008000;">"g"</span> <span style="color: #0000FF;">}</span>
<span style="color: #000080;font-style:italic;">-- 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15</span>
<span style="color: #008080;">constant</span> <span style="color: #000000;">regs</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{</span><span style="color: #008000;">"eax"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"ecx"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"edx"</span><span style="color: #0000FF;">}</span> <span style="color: #000080;font-style:italic;">-- (others as/when needed)</span>
<span style="color: #008080;">procedure</span> <span style="color: #000000;">decode</span><span style="color: #0000FF;">()</span>
<span style="color: #000080;font-style:italic;">-- for a much more complete (and better organised) disassembler, see p2asm.e</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">pc</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">0</span><span style="color: #0000FF;">,</span> <span style="color: #000080;font-style:italic;">-- nb 0-based</span>
<span style="color: #000000;">opcode</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">xrm</span>
<span style="color: #008080;">while</span> <span style="color: #000000;">pc</span><span style="color: #0000FF;"><</span><span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">code</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">do</span>
<span style="color: #000000;">opcode</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">peek</span><span style="color: #0000FF;">(</span><span style="color: #000000;">code_mem</span><span style="color: #0000FF;">+</span><span style="color: #000000;">pc</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">xrm</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">-</span><span style="color: #000000;">1</span>
<span style="color: #008080;">switch</span> <span style="color: #000000;">opcode</span> <span style="color: #008080;">do</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">0o150</span><span style="color: #0000FF;">:</span>
<span style="color: #004080;">atom</span> <span style="color: #000000;">vaddr</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">peek4s</span><span style="color: #0000FF;">(</span><span style="color: #000000;">code_mem</span><span style="color: #0000FF;">+</span><span style="color: #000000;">pc</span><span style="color: #0000FF;">+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">)</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">n</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">find</span><span style="color: #0000FF;">(</span><span style="color: #000000;">vaddr</span><span style="color: #0000FF;">,</span><span style="color: #000000;">stringptrs</span><span style="color: #0000FF;">)</span>
<span style="color: #004080;">object</span> <span style="color: #000000;">arg</span> <span style="color: #0000FF;">=</span> <span style="color: #008080;">iff</span><span style="color: #0000FF;">(</span><span style="color: #000000;">n</span><span style="color: #0000FF;">?</span><span style="color: #000000;">enquote</span><span style="color: #0000FF;">(</span><span style="color: #000000;">strings</span><span style="color: #0000FF;">[</span><span style="color: #000000;">n</span><span style="color: #0000FF;">])</span>
<span style="color: #0000FF;">:</span><span style="color: #7060A8;">sprintf</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"%d"</span><span style="color: #0000FF;">,</span><span style="color: #000000;">vaddr</span><span style="color: #0000FF;">))</span>
<span style="color: #000000;">pc</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">hxl</span><span style="color: #0000FF;">(</span><span style="color: #000000;">pc</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #000000;">4</span><span style="color: #0000FF;">},</span><span style="color: #008000;">"push %s"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">arg</span><span style="color: #0000FF;">})</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">0o217</span><span style="color: #0000FF;">:</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">0o377</span><span style="color: #0000FF;">:</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">n</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">find</span><span style="color: #0000FF;">(</span><span style="color: #000000;">opcode</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">0o217</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0o377</span><span style="color: #0000FF;">})</span>
<span style="color: #004080;">string</span> <span style="color: #000000;">op</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{</span><span style="color: #008000;">"pop"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"push"</span><span style="color: #0000FF;">}[</span><span style="color: #000000;">n</span><span style="color: #0000FF;">]</span>
<span style="color: #000000;">xrm</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">peek</span><span style="color: #0000FF;">(</span><span style="color: #000000;">code_mem</span><span style="color: #0000FF;">+</span><span style="color: #000000;">pc</span><span style="color: #0000FF;">+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">if</span> <span style="color: #000000;">n</span><span style="color: #0000FF;">!=</span><span style="color: #7060A8;">find</span><span style="color: #0000FF;">(</span><span style="color: #000000;">xrm</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">0o005</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0o065</span><span style="color: #0000FF;">})</span> <span style="color: #008080;">then</span> <span style="color: #008080;">exit</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #004080;">atom</span> <span style="color: #000000;">addr</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">peek4u</span><span style="color: #0000FF;">(</span><span style="color: #000000;">code_mem</span><span style="color: #0000FF;">+</span><span style="color: #000000;">pc</span><span style="color: #0000FF;">+</span><span style="color: #000000;">2</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">pc</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">hxl</span><span style="color: #0000FF;">(</span><span style="color: #000000;">pc</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">2</span><span style="color: #0000FF;">,</span><span style="color: #000000;">4</span><span style="color: #0000FF;">},</span><span style="color: #008000;">"%s [%s]"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">op</span><span style="color: #0000FF;">,</span><span style="color: #000000;">get_var_name</span><span style="color: #0000FF;">(</span><span style="color: #000000;">addr</span><span style="color: #0000FF;">)})</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">0o061</span><span style="color: #0000FF;">:</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">0o071</span><span style="color: #0000FF;">:</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">0o205</span><span style="color: #0000FF;">:</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">n</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">find</span><span style="color: #0000FF;">(</span><span style="color: #000000;">opcode</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">0o061</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0o071</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0o205</span><span style="color: #0000FF;">})</span>
<span style="color: #004080;">string</span> <span style="color: #000000;">op</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{</span><span style="color: #008000;">"xor"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"cmp"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"test"</span><span style="color: #0000FF;">}[</span><span style="color: #000000;">n</span><span style="color: #0000FF;">]</span>
<span style="color: #000000;">xrm</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">peek</span><span style="color: #0000FF;">(</span><span style="color: #000000;">code_mem</span><span style="color: #0000FF;">+</span><span style="color: #000000;">pc</span><span style="color: #0000FF;">+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">if</span> <span style="color: #7060A8;">and_bits</span><span style="color: #0000FF;">(</span><span style="color: #000000;">xrm</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0o300</span><span style="color: #0000FF;">)!=</span><span style="color: #000000;">0o300</span> <span style="color: #008080;">then</span> <span style="color: #008080;">exit</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #004080;">string</span> <span style="color: #000000;">r1</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">regs</span><span style="color: #0000FF;">[</span><span style="color: #7060A8;">and_bits</span><span style="color: #0000FF;">(</span><span style="color: #000000;">xrm</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0o070</span><span style="color: #0000FF;">)/</span><span style="color: #000000;">0o010</span><span style="color: #0000FF;">+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">]</span>
<span style="color: #004080;">string</span> <span style="color: #000000;">r2</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">regs</span><span style="color: #0000FF;">[</span><span style="color: #7060A8;">and_bits</span><span style="color: #0000FF;">(</span><span style="color: #000000;">xrm</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0o007</span><span style="color: #0000FF;">)+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">]</span>
<span style="color: #000000;">pc</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">hxl</span><span style="color: #0000FF;">(</span><span style="color: #000000;">pc</span><span style="color: #0000FF;">,</span><span style="color: #000000;">2</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"%s %s,%s"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">op</span><span style="color: #0000FF;">,</span><span style="color: #000000;">r1</span><span style="color: #0000FF;">,</span><span style="color: #000000;">r2</span><span style="color: #0000FF;">})</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">0o017</span><span style="color: #0000FF;">:</span>
<span style="color: #000000;">xrm</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">peek</span><span style="color: #0000FF;">(</span><span style="color: #000000;">code_mem</span><span style="color: #0000FF;">+</span><span style="color: #000000;">pc</span><span style="color: #0000FF;">+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">switch</span> <span style="color: #000000;">xrm</span> <span style="color: #008080;">do</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">0o224</span><span style="color: #0000FF;">:</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">0o225</span><span style="color: #0000FF;">:</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">0o234</span><span style="color: #0000FF;">:</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">0o235</span><span style="color: #0000FF;">:</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">0o236</span><span style="color: #0000FF;">:</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">0o237</span><span style="color: #0000FF;">:</span>
<span style="color: #004080;">string</span> <span style="color: #000000;">cc</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">cccodes</span><span style="color: #0000FF;">[</span><span style="color: #7060A8;">and_bits</span><span style="color: #0000FF;">(</span><span style="color: #000000;">xrm</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0o017</span><span style="color: #0000FF;">)+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">]</span>
<span style="color: #000000;">xrm</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">peek</span><span style="color: #0000FF;">(</span><span style="color: #000000;">code_mem</span><span style="color: #0000FF;">+</span><span style="color: #000000;">pc</span><span style="color: #0000FF;">+</span><span style="color: #000000;">2</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">if</span> <span style="color: #000000;">xrm</span><span style="color: #0000FF;">=</span><span style="color: #000000;">0o300</span> <span style="color: #008080;">then</span>
<span style="color: #000000;">pc</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">hxl</span><span style="color: #0000FF;">(</span><span style="color: #000000;">pc</span><span style="color: #0000FF;">,</span><span style="color: #000000;">3</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"set%s al"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">cc</span><span style="color: #0000FF;">})</span>
<span style="color: #008080;">elsif</span> <span style="color: #000000;">xrm</span><span style="color: #0000FF;">=</span><span style="color: #000000;">0o301</span> <span style="color: #008080;">then</span>
<span style="color: #000000;">pc</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">hxl</span><span style="color: #0000FF;">(</span><span style="color: #000000;">pc</span><span style="color: #0000FF;">,</span><span style="color: #000000;">3</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"set%s cl"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">cc</span><span style="color: #0000FF;">})</span>
<span style="color: #008080;">else</span>
<span style="color: #008080;">exit</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">0o204</span><span style="color: #0000FF;">:</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">offset</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">peek4s</span><span style="color: #0000FF;">(</span><span style="color: #000000;">code_mem</span><span style="color: #0000FF;">+</span><span style="color: #000000;">pc</span><span style="color: #0000FF;">+</span><span style="color: #000000;">2</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">pc</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">hxl</span><span style="color: #0000FF;">(</span><span style="color: #000000;">pc</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">2</span><span style="color: #0000FF;">,</span><span style="color: #000000;">4</span><span style="color: #0000FF;">},</span><span style="color: #008000;">"jz %d"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">pc</span><span style="color: #0000FF;">+</span><span style="color: #000000;">6</span><span style="color: #0000FF;">+</span><span style="color: #000000;">offset</span><span style="color: #0000FF;">+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">})</span>
<span style="color: #008080;">else</span>
<span style="color: #008080;">exit</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">switch</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">0o010</span><span style="color: #0000FF;">:</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">0o040</span><span style="color: #0000FF;">:</span>
<span style="color: #000000;">xrm</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">peek</span><span style="color: #0000FF;">(</span><span style="color: #000000;">code_mem</span><span style="color: #0000FF;">+</span><span style="color: #000000;">pc</span><span style="color: #0000FF;">+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">if</span> <span style="color: #000000;">xrm</span><span style="color: #0000FF;">=</span><span style="color: #000000;">0o310</span> <span style="color: #008080;">then</span>
<span style="color: #004080;">string</span> <span style="color: #000000;">lop</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{</span><span style="color: #008000;">"or"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"and"</span><span style="color: #0000FF;">}[</span><span style="color: #7060A8;">find</span><span style="color: #0000FF;">(</span><span style="color: #000000;">opcode</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">0o010</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0o040</span><span style="color: #0000FF;">})]</span>
<span style="color: #000000;">pc</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">hxl</span><span style="color: #0000FF;">(</span><span style="color: #000000;">pc</span><span style="color: #0000FF;">,</span><span style="color: #000000;">2</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"%s al,cl"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">lop</span><span style="color: #0000FF;">})</span>
<span style="color: #008080;">else</span>
<span style="color: #008080;">exit</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">0o120</span><span style="color: #0000FF;">:</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">0o122</span><span style="color: #0000FF;">:</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">0o130</span><span style="color: #0000FF;">:</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">0o131</span><span style="color: #0000FF;">:</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">0o132</span><span style="color: #0000FF;">:</span>
<span style="color: #004080;">string</span> <span style="color: #000000;">op</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{</span><span style="color: #008000;">"push"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"pop"</span><span style="color: #0000FF;">}[</span><span style="color: #7060A8;">find</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">and_bits</span><span style="color: #0000FF;">(</span><span style="color: #000000;">opcode</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0o070</span><span style="color: #0000FF;">),{</span><span style="color: #000000;">0o020</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0o030</span><span style="color: #0000FF;">})]</span>
<span style="color: #004080;">string</span> <span style="color: #000000;">reg</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">regs</span><span style="color: #0000FF;">[</span><span style="color: #7060A8;">and_bits</span><span style="color: #0000FF;">(</span><span style="color: #000000;">opcode</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0o007</span><span style="color: #0000FF;">)+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">]</span>
<span style="color: #000000;">pc</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">hxl</span><span style="color: #0000FF;">(</span><span style="color: #000000;">pc</span><span style="color: #0000FF;">,</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"%s %s"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">op</span><span style="color: #0000FF;">,</span><span style="color: #000000;">reg</span><span style="color: #0000FF;">})</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">0o231</span><span style="color: #0000FF;">:</span>
<span style="color: #000000;">pc</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">hxl</span><span style="color: #0000FF;">(</span><span style="color: #000000;">pc</span><span style="color: #0000FF;">,</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"cdq"</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">0o164</span><span style="color: #0000FF;">:</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">0o353</span><span style="color: #0000FF;">:</span>
<span style="color: #004080;">string</span> <span style="color: #000000;">jop</span> <span style="color: #0000FF;">=</span> <span style="color: #008080;">iff</span><span style="color: #0000FF;">(</span><span style="color: #000000;">opcode</span><span style="color: #0000FF;">=</span><span style="color: #000000;">0o164</span><span style="color: #0000FF;">?</span><span style="color: #008000;">"jz"</span><span style="color: #0000FF;">:</span><span style="color: #008000;">"jmp"</span><span style="color: #0000FF;">)</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">offset</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">peek1s</span><span style="color: #0000FF;">(</span><span style="color: #000000;">code_mem</span><span style="color: #0000FF;">+</span><span style="color: #000000;">pc</span><span style="color: #0000FF;">+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">pc</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">hxl</span><span style="color: #0000FF;">(</span><span style="color: #000000;">pc</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #000000;">1</span><span style="color: #0000FF;">},</span><span style="color: #008000;">"%s %d"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">jop</span><span style="color: #0000FF;">,</span><span style="color: #000000;">pc</span><span style="color: #0000FF;">+</span><span style="color: #000000;">2</span><span style="color: #0000FF;">+</span><span style="color: #000000;">offset</span><span style="color: #0000FF;">+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">})</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">0o351</span><span style="color: #0000FF;">:</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">offset</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">peek4s</span><span style="color: #0000FF;">(</span><span style="color: #000000;">code_mem</span><span style="color: #0000FF;">+</span><span style="color: #000000;">pc</span><span style="color: #0000FF;">+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">pc</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">hxl</span><span style="color: #0000FF;">(</span><span style="color: #000000;">pc</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #000000;">4</span><span style="color: #0000FF;">},</span><span style="color: #008000;">"jmp %d"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">pc</span><span style="color: #0000FF;">+</span><span style="color: #000000;">5</span><span style="color: #0000FF;">+</span><span style="color: #000000;">offset</span><span style="color: #0000FF;">+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">})</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">0o303</span><span style="color: #0000FF;">:</span>
<span style="color: #000000;">pc</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">hxl</span><span style="color: #0000FF;">(</span><span style="color: #000000;">pc</span><span style="color: #0000FF;">,</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"ret"</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">0o350</span><span style="color: #0000FF;">:</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">offset</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">peek4s</span><span style="color: #0000FF;">(</span><span style="color: #000000;">code_mem</span><span style="color: #0000FF;">+</span><span style="color: #000000;">pc</span><span style="color: #0000FF;">+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">)</span>
<span style="color: #004080;">atom</span> <span style="color: #000000;">addr</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">offset</span><span style="color: #0000FF;">+</span><span style="color: #000000;">code_mem</span><span style="color: #0000FF;">+</span><span style="color: #000000;">pc</span><span style="color: #0000FF;">+</span><span style="color: #000000;">5</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">n</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">find</span><span style="color: #0000FF;">(</span><span style="color: #000000;">addr</span><span style="color: #0000FF;">,</span><span style="color: #000000;">builtins</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">pc</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">hxl</span><span style="color: #0000FF;">(</span><span style="color: #000000;">pc</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #000000;">4</span><span style="color: #0000FF;">},</span><span style="color: #008000;">"call :%s"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">builtin_names</span><span style="color: #0000FF;">[</span><span style="color: #000000;">n</span><span style="color: #0000FF;">]})</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">0o001</span><span style="color: #0000FF;">:</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">0o041</span><span style="color: #0000FF;">:</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">0o051</span><span style="color: #0000FF;">:</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">n</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">find</span><span style="color: #0000FF;">(</span><span style="color: #000000;">opcode</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">0o001</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0o041</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0o051</span><span style="color: #0000FF;">})</span>
<span style="color: #004080;">string</span> <span style="color: #000000;">op</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{</span><span style="color: #008000;">"add"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"and"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"sub"</span><span style="color: #0000FF;">}[</span><span style="color: #000000;">n</span><span style="color: #0000FF;">]</span>
<span style="color: #000000;">xrm</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">peek</span><span style="color: #0000FF;">(</span><span style="color: #000000;">code_mem</span><span style="color: #0000FF;">+</span><span style="color: #000000;">pc</span><span style="color: #0000FF;">+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">switch</span> <span style="color: #000000;">xrm</span> <span style="color: #008080;">do</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">0o004</span><span style="color: #0000FF;">:</span>
<span style="color: #008080;">if</span> <span style="color: #7060A8;">peek</span><span style="color: #0000FF;">(</span><span style="color: #000000;">code_mem</span><span style="color: #0000FF;">+</span><span style="color: #000000;">pc</span><span style="color: #0000FF;">+</span><span style="color: #000000;">2</span><span style="color: #0000FF;">)=</span><span style="color: #000000;">0o044</span> <span style="color: #008080;">then</span>
<span style="color: #000000;">pc</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">hxl</span><span style="color: #0000FF;">(</span><span style="color: #000000;">pc</span><span style="color: #0000FF;">,</span><span style="color: #000000;">3</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"%s [esp],eax"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">op</span><span style="color: #0000FF;">})</span>
<span style="color: #008080;">else</span>
<span style="color: #008080;">exit</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #008080;">else</span>
<span style="color: #008080;">exit</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">switch</span>
<span style="color: #008080;">case</span> <span style="color: #000000;">0o367</span><span style="color: #0000FF;">:</span>
<span style="color: #000000;">xrm</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">peek</span><span style="color: #0000FF;">(</span><span style="color: #000000;">code_mem</span><span style="color: #0000FF;">+</span><span style="color: #000000;">pc</span><span style="color: #0000FF;">+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">if</span> <span style="color: #7060A8;">and_bits</span><span style="color: #0000FF;">(</span><span style="color: #000000;">xrm</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0o300</span><span style="color: #0000FF;">)!=</span><span style="color: #000000;">0o300</span> <span style="color: #008080;">then</span> <span style="color: #008080;">exit</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">n</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">find</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">and_bits</span><span style="color: #0000FF;">(</span><span style="color: #000000;">xrm</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0o070</span><span style="color: #0000FF;">),{</span><span style="color: #000000;">0o030</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0o040</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0o070</span><span style="color: #0000FF;">})</span>
<span style="color: #008080;">if</span> <span style="color: #000000;">n</span><span style="color: #0000FF;">=</span><span style="color: #000000;">0</span> <span style="color: #008080;">then</span> <span style="color: #008080;">exit</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #004080;">string</span> <span style="color: #000000;">op</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{</span><span style="color: #008000;">"neg"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"mul"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"idiv"</span><span style="color: #0000FF;">}[</span><span style="color: #000000;">n</span><span style="color: #0000FF;">]</span>
<span style="color: #004080;">string</span> <span style="color: #000000;">reg</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">regs</span><span style="color: #0000FF;">[</span><span style="color: #7060A8;">and_bits</span><span style="color: #0000FF;">(</span><span style="color: #000000;">xrm</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0o007</span><span style="color: #0000FF;">)+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">]</span>
<span style="color: #000000;">pc</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">hxl</span><span style="color: #0000FF;">(</span><span style="color: #000000;">pc</span><span style="color: #0000FF;">,</span><span style="color: #000000;">2</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"%s %s"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">op</span><span style="color: #0000FF;">,</span><span style="color: #000000;">reg</span><span style="color: #0000FF;">})</span>
<span style="color: #008080;">else</span>
<span style="color: #008080;">exit</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">switch</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">while</span>
<span style="color: #008080;">if</span> <span style="color: #000000;">pc</span><span style="color: #0000FF;"><</span><span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">code</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">then</span>
<span style="color: #0000FF;">?</span><span style="color: #008000;">"incomplete:"</span>
<span style="color: #008080;">if</span> <span style="color: #000000;">xrm</span><span style="color: #0000FF;">=-</span><span style="color: #000000;">1</span> <span style="color: #008080;">then</span>
<span style="color: #0000FF;">?{</span><span style="color: #000000;">pc</span><span style="color: #0000FF;">+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #7060A8;">sprintf</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"0o%03o"</span><span style="color: #0000FF;">,</span><span style="color: #000000;">opcode</span><span style="color: #0000FF;">)}</span>
<span style="color: #008080;">else</span>
<span style="color: #0000FF;">?{</span><span style="color: #000000;">pc</span><span style="color: #0000FF;">+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #7060A8;">sprintf</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"0o%03o 0o%03o"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">opcode</span><span style="color: #0000FF;">,</span><span style="color: #000000;">xrm</span><span style="color: #0000FF;">})}</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">procedure</span>
<span style="color: #008080;">procedure</span> <span style="color: #000000;">main</span><span style="color: #0000FF;">(</span><span style="color: #004080;">sequence</span> <span style="color: #000000;">cl</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">open_files</span><span style="color: #0000FF;">(</span><span style="color: #000000;">cl</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">toks</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">lex</span><span style="color: #0000FF;">()</span>
<span style="color: #004080;">object</span> <span style="color: #000000;">t</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">parse</span><span style="color: #0000FF;">()</span>
<span style="color: #000000;">code_gen</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">fixup</span><span style="color: #0000FF;">()</span>
<span style="color: #000000;">decode</span><span style="color: #0000FF;">()</span>
<span style="color: #7060A8;">free</span><span style="color: #0000FF;">({</span><span style="color: #000000;">var_mem</span><span style="color: #0000FF;">,</span><span style="color: #000000;">code_mem</span><span style="color: #0000FF;">})</span>
<span style="color: #000000;">close_files</span><span style="color: #0000FF;">()</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">procedure</span>
<span style="color: #000080;font-style:italic;">--main(command_line())</span>
<span style="color: #000000;">main</span><span style="color: #0000FF;">({</span><span style="color: #000000;">0</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"gcd.c"</span><span style="color: #0000FF;">})</span>
<!--</syntaxhighlight>-->
{{out}}
<pre>
Line 1,655 ⟶ 7,880:
=={{header|Python}}==
Tested with Python 2.7 and 3.x
<langsyntaxhighlight Pythonlang="python">from __future__ import print_function
import sys, struct, shlex, operator
 
Line 1,908 ⟶ 8,133:
code_gen(n)
code_finish()
list_code()</langsyntaxhighlight>
 
{{out|case=While counter example}}
Line 1,934 ⟶ 8,159:
65 halt</pre>
</b>
 
=={{header|Raku}}==
(formerly Perl 6)
Using 'while-count' example, input used is here: [https://github.com/SqrtNegInf/Rosettacode-Perl6-Smoke/blob/master/ref/ast.txt ast.txt]
{{trans|Perl}}
<syntaxhighlight lang="raku" line>my %opnames = <
Less lt LessEqual le Multiply mul Subtract sub NotEqual ne
Divide div GreaterEqual ge Equal eq Greater gt Negate neg
>;
 
my (@AST, %strings, %names);
my $string-count = my $name-count = my $pairsym = my $pc = 0;
 
sub tree {
my ($A, $B) = ( '_' ~ ++$pairsym, '_' ~ ++$pairsym );
my $line = @AST.shift // return '';
$line ~~ /^ $<instr> = (\w+|';') [\s+ $<arg> =(.*)]? / or die "bad input $line";
given $<instr> {
when 'Identifier' { "fetch [{%names{$<arg>} //= $name-count++ }]\n" }
when 'Sequence' { tree() ~ tree() }
when 'Integer' { "push $<arg>\n" }
when 'String' { "push { %strings{$<arg>} //= $string-count++ }\n" }
when 'Assign' { join '', reverse (tree().subst( /fetch/, 'store')), tree() }
when 'While' { "$A:\n{ tree() }jz $B\n{ tree() }jmp $A\n$B:\n" }
when 'If' { tree() ~ "jz $A\n{ !@AST.shift ~ tree() }jmp $B\n$A:\n{ tree() }$B:\n" }
when ';' { '' }
default { tree() ~ tree() ~ (%opnames{$<instr>} // $<instr>.lc) ~ "\n" }
}
}
 
@AST = slurp('ast.txt').lines;
my $code = tree() ~ "halt\n";
 
$code ~~ s:g/^^ jmp \s+ (\S+) \n ('_'\d+:\n) $0:\n/$1/; # remove jmp next
$code ~~ s:g/^^ (<[a..z]>\w* (\N+)? ) $$/{my $l=$pc.fmt("%4d "); $pc += $0[0] ?? 5 !! 1; $l}$0/; # add locations
my %labels = ($code ~~ m:g/^^ ('_' \d+) ':' \n \s* (\d+)/)».Slip».Str; # pc addr of labels
$code ~~ s:g/^^ \s* (\d+) \s j[z|mp] \s* <(('_'\d+)/ ({%labels{$1} - $0 - 1}) %labels{$1}/; # fix jumps
$code ~~ s:g/^^ '_'\d+.*?\n//; # remove labels
 
say "Datasize: $name-count Strings: $string-count\n"
~ join('', %strings.keys.sort.reverse «~» "\n")
~ $code;</syntaxhighlight>
{{out}}
<pre>Datasize: 1 Strings: 2
"count is: "
"\n"
0 push 1
5 store [0]
10 fetch [0]
15 push 10
20 lt
21 jz (43) 65
26 push 0
31 prts
32 fetch [0]
37 prti
38 push 1
43 prts
44 fetch [0]
49 push 1
54 add
55 store [0]
60 jmp (-51) 10
65 halt</pre>
 
=={{header|RATFOR}}==
{{works with|ratfor77|[https://sourceforge.net/p/chemoelectric/ratfor77/ public domain 1.0]}}
{{works with|gfortran|11.3.0}}
{{works with|f2c|20100827}}
 
 
<syntaxhighlight lang="ratfor">######################################################################
#
# The Rosetta Code code generator in Ratfor 77.
#
#
# In FORTRAN 77 and therefore in Ratfor 77, there is no way to specify
# that a value should be put on a call stack. Therefore there is no
# way to implement recursive algorithms in Ratfor 77 (although see the
# Ratfor for the "syntax analyzer" task, where a recursive language is
# implemented *in* Ratfor). We are forced to use non-recursive
# algorithms.
#
# How to deal with FORTRAN 77 input is another problem. I use
# formatted input, treating each line as an array of type
# CHARACTER--regrettably of no more than some predetermined, finite
# length. It is a very simple method and presents no significant
# difficulties, aside from the restriction on line length of the
# input.
#
#
# On a POSIX platform, the program can be compiled with f2c and run
# somewhat as follows:
#
# ratfor77 gen-in-ratfor.r > gen-in-ratfor.f
# f2c -C -Nc80 gen-in-ratfor.f
# cc gen-in-ratfor.c -lf2c
# ./a.out < compiler-tests/primes.ast
#
# With gfortran, a little differently:
#
# ratfor77 gen-in-ratfor.r > gen-in-ratfor.f
# gfortran -fcheck=all -std=legacy gen-in-ratfor.f
# ./a.out < compiler-tests/primes.ast
#
#
# I/O is strictly from default input and to default output, which, on
# POSIX systems, usually correspond respectively to standard input and
# standard output. (I did not wish to have to deal with unit numbers;
# these are now standardized in ISO_FORTRAN_ENV, but that is not
# available in FORTRAN 77.)
#
#---------------------------------------------------------------------
 
# Some parameters you may wish to modify.
 
define(LINESZ, 256) # Size of an input line.
define(OUTLSZ, 1024) # Size of an output line.
define(STRNSZ, 4096) # Size of the string pool.
define(NODSSZ, 4096) # Size of the nodes pool.
define(STCKSZ, 4096) # Size of stacks.
define(MAXVAR, 256) # Maximum number of variables.
define(MAXSTR, 256) # Maximum number of strings.
define(CODESZ, 16384) # Maximum size of a compiled program.
 
#---------------------------------------------------------------------
 
define(NEWLIN, 10) # The Unix newline character (ASCII LF).
define(DQUOTE, 34) # The double quote character.
define(BACKSL, 92) # The backslash character.
 
#---------------------------------------------------------------------
 
define(NODESZ, 3)
define(NNEXTF, 1) # Index for next-free.
define(NTAG, 1) # Index for the tag.
# For an internal node --
define(NLEFT, 2) # Index for the left node.
define(NRIGHT, 3) # Index for the right node.
# For a leaf node --
define(NITV, 2) # Index for the string pool index.
define(NITN, 3) # Length of the value.
 
define(NIL, -1) # Nil node.
 
define(RGT, 10000)
define(STAGE2, 20000)
define(STAGE3, 30000)
define(STAGE4, 40000)
 
# The following all must be less than RGT.
define(NDID, 0)
define(NDSTR, 1)
define(NDINT, 2)
define(NDSEQ, 3)
define(NDIF, 4)
define(NDPRTC, 5)
define(NDPRTS, 6)
define(NDPRTI, 7)
define(NDWHIL, 8)
define(NDASGN, 9)
define(NDNEG, 10)
define(NDNOT, 11)
define(NDMUL, 12)
define(NDDIV, 13)
define(NDMOD, 14)
define(NDADD, 15)
define(NDSUB, 16)
define(NDLT, 17)
define(NDLE, 18)
define(NDGT, 19)
define(NDGE, 20)
define(NDEQ, 21)
define(NDNE, 22)
define(NDAND, 23)
define(NDOR, 24)
 
define(OPHALT, 1)
define(OPADD, 2)
define(OPSUB, 3)
define(OPMUL, 4)
define(OPDIV, 5)
define(OPMOD, 6)
define(OPLT, 7)
define(OPGT, 8)
define(OPLE, 9)
define(OPGE, 10)
define(OPEQ, 11)
define(OPNE, 12)
define(OPAND, 13)
define(OPOR, 14)
define(OPNEG, 15)
define(OPNOT, 16)
define(OPPRTC, 17)
define(OPPRTI, 18)
define(OPPRTS, 19)
define(OPFTCH, 20)
define(OPSTOR, 21)
define(OPPUSH, 22)
define(OPJMP, 23)
define(OPJZ, 24)
 
#---------------------------------------------------------------------
 
function issp (c)
 
# Is a character a space character?
 
implicit none
 
character c
logical issp
 
integer ic
 
ic = ichar (c)
issp = (ic == 32 || (9 <= ic && ic <= 13))
end
 
function skipsp (str, i, imax)
 
# Skip past spaces in a string.
 
implicit none
 
character str(*)
integer i
integer imax
integer skipsp
 
logical issp
 
logical done
 
skipsp = i
done = .false.
while (!done)
{
if (imax <= skipsp)
done = .true.
else if (!issp (str(skipsp)))
done = .true.
else
skipsp = skipsp + 1
}
end
 
function skipns (str, i, imax)
 
# Skip past non-spaces in a string.
 
implicit none
 
character str(*)
integer i
integer imax
integer skipns
 
logical issp
 
logical done
 
skipns = i
done = .false.
while (!done)
{
if (imax <= skipns)
done = .true.
else if (issp (str(skipns)))
done = .true.
else
skipns = skipns + 1
}
end
 
function trimrt (str, n)
 
# Find the length of a string, if one ignores trailing spaces.
 
implicit none
 
character str(*)
integer n
integer trimrt
 
logical issp
 
logical done
 
trimrt = n
done = .false.
while (!done)
{
if (trimrt == 0)
done = .true.
else if (!issp (str(trimrt)))
done = .true.
else
trimrt = trimrt - 1
}
end
 
#---------------------------------------------------------------------
 
subroutine addstr (strngs, istrng, src, i0, n0, i, n)
 
# Add a string to the string pool.
 
implicit none
 
character strngs(STRNSZ) # String pool.
integer istrng # String pool's next slot.
character src(*) # Source string.
integer i0, n0 # Index and length in source string.
integer i, n # Index and length in string pool.
 
integer j
 
if (STRNSZ < istrng + (n0 - 1))
{
write (*, '(''string pool exhausted'')')
stop
}
if (n0 == 0)
{
i = 0
n = 0
}
else
{
for (j = 0; j < n0; j = j + 1)
strngs(istrng + j) = src(i0 + j)
i = istrng
n = n0
istrng = istrng + n0
}
end
 
#---------------------------------------------------------------------
 
subroutine push (stack, sp, i)
 
implicit none
 
integer stack(STCKSZ)
integer sp # Stack pointer.
integer i # Value to push.
 
if (sp == STCKSZ)
{
write (*, '(''stack overflow in push'')')
stop
}
stack(sp) = i
sp = sp + 1
end
 
function pop (stack, sp)
 
implicit none
 
integer stack(STCKSZ)
integer sp # Stack pointer.
integer pop
 
if (sp == 1)
{
write (*, '(''stack underflow in pop'')')
stop
}
sp = sp - 1
pop = stack(sp)
end
 
function nstack (sp)
 
implicit none
 
integer sp # Stack pointer.
integer nstack
 
nstack = sp - 1 # Current cardinality of the stack.
end
 
#---------------------------------------------------------------------
 
subroutine initnd (nodes, frelst)
 
# Initialize the nodes pool.
 
implicit none
 
integer nodes (NODESZ, NODSSZ)
integer frelst # Head of the free list.
 
integer i
 
for (i = 1; i < NODSSZ; i = i + 1)
nodes(NNEXTF, i) = i + 1
nodes(NNEXTF, NODSSZ) = NIL
frelst = 1
end
 
subroutine newnod (nodes, frelst, i)
 
# Get the index for a new node taken from the free list.
 
integer nodes (NODESZ, NODSSZ)
integer frelst # Head of the free list.
integer i # Index of the new node.
 
integer j
 
if (frelst == NIL)
{
write (*, '(''nodes pool exhausted'')')
stop
}
i = frelst
frelst = nodes(NNEXTF, frelst)
for (j = 1; j <= NODESZ; j = j + 1)
nodes(j, i) = 0
end
 
subroutine frenod (nodes, frelst, i)
 
# Return a node to the free list.
 
integer nodes (NODESZ, NODSSZ)
integer frelst # Head of the free list.
integer i # Index of the node to free.
 
nodes(NNEXTF, i) = frelst
frelst = i
end
 
function strtag (str, i, n)
 
implicit none
 
character str(*)
integer i, n
integer strtag
 
character*16 s
integer j
 
for (j = 0; j < 16; j = j + 1)
if (j < n)
s(j + 1 : j + 1) = str(i + j)
else
s(j + 1 : j + 1) = ' '
 
if (s == "Identifier ")
strtag = NDID
else if (s == "String ")
strtag = NDSTR
else if (s == "Integer ")
strtag = NDINT
else if (s == "Sequence ")
strtag = NDSEQ
else if (s == "If ")
strtag = NDIF
else if (s == "Prtc ")
strtag = NDPRTC
else if (s == "Prts ")
strtag = NDPRTS
else if (s == "Prti ")
strtag = NDPRTI
else if (s == "While ")
strtag = NDWHIL
else if (s == "Assign ")
strtag = NDASGN
else if (s == "Negate ")
strtag = NDNEG
else if (s == "Not ")
strtag = NDNOT
else if (s == "Multiply ")
strtag = NDMUL
else if (s == "Divide ")
strtag = NDDIV
else if (s == "Mod ")
strtag = NDMOD
else if (s == "Add ")
strtag = NDADD
else if (s == "Subtract ")
strtag = NDSUB
else if (s == "Less ")
strtag = NDLT
else if (s == "LessEqual ")
strtag = NDLE
else if (s == "Greater ")
strtag = NDGT
else if (s == "GreaterEqual ")
strtag = NDGE
else if (s == "Equal ")
strtag = NDEQ
else if (s == "NotEqual ")
strtag = NDNE
else if (s == "And ")
strtag = NDAND
else if (s == "Or ")
strtag = NDOR
else if (s == "; ")
strtag = NIL
else
{
write (*, '(''unrecognized input line: '', A16)') s
stop
}
end
 
subroutine readln (strngs, istrng, tag, iarg, narg)
 
# Read a line of the AST input.
 
implicit none
 
character strngs(STRNSZ) # String pool.
integer istrng # String pool's next slot.
integer tag # The node tag or NIL.
integer iarg # Index of an argument in the string pool.
integer narg # Length of an argument in the string pool.
 
integer trimrt
integer strtag
integer skipsp
integer skipns
 
character line(LINESZ)
character*20 fmt
integer i, j, n
 
# Read a line of text as an array of characters.
write (fmt, '(''('', I10, ''A)'')') LINESZ
read (*, fmt) line
 
n = trimrt (line, LINESZ)
 
i = skipsp (line, 1, n + 1)
j = skipns (line, i, n + 1)
tag = strtag (line, i, j - i)
 
i = skipsp (line, j, n + 1)
call addstr (strngs, istrng, line, i, (n + 1) - i, iarg, narg)
end
 
function hasarg (tag)
 
implicit none
 
integer tag
logical hasarg
 
hasarg = (tag == NDID || tag == NDINT || tag == NDSTR)
end
 
subroutine rdast (strngs, istrng, nodes, frelst, iast)
 
# Read in the AST. A non-recursive algorithm is used.
 
implicit none
 
character strngs(STRNSZ) # String pool.
integer istrng # String pool's next slot.
integer nodes (NODESZ, NODSSZ) # Nodes pool.
integer frelst # Head of the free list.
integer iast # Index of root node of the AST.
 
integer nstack
integer pop
logical hasarg
 
integer stack(STCKSZ)
integer sp # Stack pointer.
integer tag, iarg, narg
integer i, j, k
 
sp = 1
 
call readln (strngs, istrng, tag, iarg, narg)
if (tag == NIL)
iast = NIL
else
{
call newnod (nodes, frelst, i)
iast = i
nodes(NTAG, i) = tag
nodes(NITV, i) = 0
nodes(NITN, i) = 0
if (hasarg (tag))
{
nodes(NITV, i) = iarg
nodes(NITN, i) = narg
}
else
{
call push (stack, sp, i + RGT)
call push (stack, sp, i)
while (nstack (sp) != 0)
{
j = pop (stack, sp)
k = mod (j, RGT)
call readln (strngs, istrng, tag, iarg, narg)
if (tag == NIL)
i = NIL
else
{
call newnod (nodes, frelst, i)
nodes(NTAG, i) = tag
if (hasarg (tag))
{
nodes(NITV, i) = iarg
nodes(NITN, i) = narg
}
else
{
call push (stack, sp, i + RGT)
call push (stack, sp, i)
}
}
if (j == k)
nodes(NLEFT, k) = i
else
nodes(NRIGHT, k) = i
}
}
}
end
 
#---------------------------------------------------------------------
 
subroutine flushl (outbuf, noutbf)
 
# Flush a line from the output buffer.
 
implicit none
 
character outbuf(OUTLSZ) # Output line buffer.
integer noutbf # Number of characters in outbuf.
 
character*20 fmt
integer i
 
if (noutbf == 0)
write (*, '()')
else
{
write (fmt, 1000) noutbf
1000 format ('(', I10, 'A)')
write (*, fmt) (outbuf(i), i = 1, noutbf)
noutbf = 0
}
end
 
subroutine wrtchr (outbuf, noutbf, ch)
 
# Write a character to output.
 
implicit none
 
character outbuf(OUTLSZ) # Output line buffer.
integer noutbf # Number of characters in outbuf.
character ch # The character to output.
 
# This routine silently truncates anything that goes past the buffer
# boundary.
 
if (ch == char (NEWLIN))
call flushl (outbuf, noutbf)
else if (noutbf < OUTLSZ)
{
noutbf = noutbf + 1
outbuf(noutbf) = ch
}
end
 
subroutine wrtstr (outbuf, noutbf, str, i, n)
 
# Write a substring to output.
 
implicit none
 
character outbuf(OUTLSZ) # Output line buffer.
integer noutbf # Number of characters in outbuf.
character str(*) # The string from which to output.
integer i, n # Index and length of the substring.
 
integer j
 
for (j = 0; j < n; j = j + 1)
call wrtchr (outbuf, noutbf, str(i + j))
end
 
subroutine wrtint (outbuf, noutbf, ival, colcnt)
 
# Write a non-negative integer to output.
 
implicit none
 
character outbuf(OUTLSZ) # Output line buffer.
integer noutbf # Number of characters in outbuf.
integer ival # The non-negative integer to print.
integer colcnt # Column count, or zero for free format.
 
integer skipsp
 
character*40 buf
integer i, j
 
write (buf, '(I40)') ival
i = skipsp (buf, 1, 41)
if (0 < colcnt)
for (j = 1; j < colcnt - (40 - i); j = j + 1)
call wrtchr (outbuf, noutbf, ' ')
while (i <= 40)
{
call wrtchr (outbuf, noutbf, buf(i:i))
i = i + 1
}
end
 
#---------------------------------------------------------------------
 
define(VARSZ, 3)
define(VNAMEI, 1) # Variable name's index in the string pool.
define(VNAMEN, 2) # Length of the name.
define(VVALUE, 3) # Variable's number in the VM's data pool.
 
function fndvar (vars, numvar, strngs, istrng, i0, n0)
 
implicit none
 
integer vars(VARSZ, MAXVAR) # Variables.
integer numvar # Number of variables.
character strngs(STRNSZ) # String pool.
integer istrng # String pool's next slot.
integer i0, n0 # Index and length in the string pool.
integer fndvar # The location of the variable.
 
integer j, k
integer i, n
logical done1
logical done2
 
j = 1
done1 = .false.
while (!done1)
if (j == numvar + 1)
done1 = .true.
else if (n0 == vars(VNAMEN, j))
{
k = 0
done2 = .false.
while (!done2)
if (n0 <= k)
done2 = .true.
else if (strngs(i0 + k) == strngs(vars(VNAMEI, j) + k))
k = k + 1
else
done2 = .true.
if (k < n0)
j = j + 1
else
{
done2 = .true.
done1 = .true.
}
}
else
j = j + 1
 
if (j == numvar + 1)
{
if (numvar == MAXVAR)
{
write (*, '(''too many variables'')')
stop
}
numvar = numvar + 1
call addstr (strngs, istrng, strngs, i0, n0, i, n)
vars(VNAMEI, numvar) = i
vars(VNAMEN, numvar) = n
vars(VVALUE, numvar) = numvar - 1
fndvar = numvar
}
else
fndvar = j
end
 
define(STRSZ, 3)
define(STRI, 1) # String's index in this program's string pool.
define(STRN, 2) # Length of the string.
define(STRNO, 3) # String's number in the VM's string pool.
 
function fndstr (strs, numstr, strngs, istrng, i0, n0)
 
implicit none
 
integer strs(STRSZ, MAXSTR) # Strings for the VM's string pool.
integer numstr # Number of such strings.
character strngs(STRNSZ) # String pool.
integer istrng # String pool's next slot.
integer i0, n0 # Index and length in the string pool.
integer fndstr # The location of the string in the VM's string pool.
 
integer j, k
integer i, n
logical done1
logical done2
 
j = 1
done1 = .false.
while (!done1)
if (j == numstr + 1)
done1 = .true.
else if (n0 == strs(STRN, j))
{
k = 0
done2 = .false.
while (!done2)
if (n0 <= k)
done2 = .true.
else if (strngs(i0 + k) == strngs(strs(STRI, j) + k))
k = k + 1
else
done2 = .true.
if (k < n0)
j = j + 1
else
{
done2 = .true.
done1 = .true.
}
}
else
j = j + 1
 
if (j == numstr + 1)
{
if (numstr == MAXSTR)
{
write (*, '(''too many string literals'')')
stop
}
numstr = numstr + 1
call addstr (strngs, istrng, strngs, i0, n0, i, n)
strs(STRI, numstr) = i
strs(STRN, numstr) = n
strs(STRNO, numstr) = numstr - 1
fndstr = numstr
}
else
fndstr = j
end
 
function strint (strngs, i, n)
 
# Convert a string to a non-negative integer.
 
implicit none
 
character strngs(STRNSZ) # String pool.
integer i, n
integer strint
 
integer j
 
strint = 0
for (j = 0; j < n; j = j + 1)
strint = (10 * strint) + (ichar (strngs(i + j)) - ichar ('0'))
end
 
subroutine put1 (code, ncode, i, opcode)
 
# Store a 1-byte operation.
 
implicit none
 
integer code(0 : CODESZ - 1) # Generated code.
integer ncode # Number of VM bytes in the code.
integer i # Address to put the code at.
integer opcode
 
if (CODESZ - i < 1)
{
write (*, '(''address beyond the size of memory'')')
stop
}
code(i) = opcode
ncode = max (ncode, i + 1)
end
 
subroutine put5 (code, ncode, i, opcode, ival)
 
# Store a 5-byte operation.
 
implicit none
 
integer code(0 : CODESZ - 1) # Generated code.
integer ncode # Number of VM bytes in the code.
integer i # Address to put the code at.
integer opcode
integer ival # Immediate integer value.
 
if (CODESZ - i < 5)
{
write (*, '(''address beyond the size of memory'')')
stop
}
code(i) = opcode
code(i + 1) = ival # Do not bother to break the integer into bytes.
code(i + 2) = 0
code(i + 3) = 0
code(i + 4) = 0
ncode = max (ncode, i + 5)
end
 
subroutine compil (vars, numvar, _
strs, numstr, _
strngs, istrng, _
nodes, frelst, _
code, ncode, iast)
 
# Compile the AST to virtual machine code. The algorithm employed is
# non-recursive.
 
implicit none
 
integer vars(VARSZ, MAXVAR) # Variables.
integer numvar # Number of variables.
integer strs(STRSZ, MAXSTR) # Strings for the VM's string pool.
integer numstr # Number of such strings.
character strngs(STRNSZ) # String pool.
integer istrng # String pool's next slot.
integer nodes (NODESZ, NODSSZ) # Nodes pool.
integer frelst # Head of the free list.
integer code(0 : CODESZ - 1) # Generated code.
integer ncode # Number of VM bytes in the code.
integer iast # Root node of the AST.
 
integer fndvar
integer fndstr
integer nstack
integer pop
integer strint
 
integer xstack(STCKSZ) # Node stack.
integer ixstck # Node stack pointer.
integer i
integer i0, n0
integer tag
integer ivar
integer inode1, inode2, inode3
integer addr1, addr2
 
ixstck = 1
call push (xstack, ixstck, iast)
while (nstack (ixstck) != 0)
{
i = pop (xstack, ixstck)
if (i == NIL)
tag = NIL
else
tag = nodes(NTAG, i)
if (tag == NIL)
continue
else if (tag < STAGE2)
{
if (tag == NDSEQ)
{
if (nodes(NRIGHT, i) != NIL)
call push (xstack, ixstck, nodes(NRIGHT, i))
if (nodes(NLEFT, i) != NIL)
call push (xstack, ixstck, nodes(NLEFT, i))
}
else if (tag == NDID)
{
# Fetch the value of a variable.
i0 = nodes(NITV, i)
n0 = nodes(NITN, i)
ivar = fndvar (vars, numvar, strngs, istrng, i0, n0)
ivar = vars(VVALUE, ivar)
call put5 (code, ncode, ncode, OPFTCH, ivar)
}
else if (tag == NDINT)
{
# Push the value of an integer literal.
i0 = nodes(NITV, i)
n0 = nodes(NITN, i)
call put5 (code, ncode, ncode, OPPUSH, _
strint (strngs, i0, n0))
}
else if (tag == NDNEG)
{
call newnod (nodes, frelst, inode1)
nodes(NTAG, inode1) = NDNEG + STAGE2
call push (xstack, ixstck, inode1)
call push (xstack, ixstck, nodes(NLEFT, i))
}
else if (tag == NDNOT)
{
call newnod (nodes, frelst, inode1)
nodes(NTAG, inode1) = NDNOT + STAGE2
call push (xstack, ixstck, inode1)
call push (xstack, ixstck, nodes(NLEFT, i))
}
else if (tag == NDAND)
{
call newnod (nodes, frelst, inode1)
nodes(NTAG, inode1) = NDAND + STAGE2
call push (xstack, ixstck, inode1)
call push (xstack, ixstck, nodes(NRIGHT, i))
call push (xstack, ixstck, nodes(NLEFT, i))
}
else if (tag == NDOR)
{
call newnod (nodes, frelst, inode1)
nodes(NTAG, inode1) = NDOR + STAGE2
call push (xstack, ixstck, inode1)
call push (xstack, ixstck, nodes(NRIGHT, i))
call push (xstack, ixstck, nodes(NLEFT, i))
}
else if (tag == NDADD)
{
call newnod (nodes, frelst, inode1)
nodes(NTAG, inode1) = NDADD + STAGE2
call push (xstack, ixstck, inode1)
call push (xstack, ixstck, nodes(NRIGHT, i))
call push (xstack, ixstck, nodes(NLEFT, i))
}
else if (tag == NDSUB)
{
call newnod (nodes, frelst, inode1)
nodes(NTAG, inode1) = NDSUB + STAGE2
call push (xstack, ixstck, inode1)
call push (xstack, ixstck, nodes(NRIGHT, i))
call push (xstack, ixstck, nodes(NLEFT, i))
}
else if (tag == NDMUL)
{
call newnod (nodes, frelst, inode1)
nodes(NTAG, inode1) = NDMUL + STAGE2
call push (xstack, ixstck, inode1)
call push (xstack, ixstck, nodes(NRIGHT, i))
call push (xstack, ixstck, nodes(NLEFT, i))
}
else if (tag == NDDIV)
{
call newnod (nodes, frelst, inode1)
nodes(NTAG, inode1) = NDDIV + STAGE2
call push (xstack, ixstck, inode1)
call push (xstack, ixstck, nodes(NRIGHT, i))
call push (xstack, ixstck, nodes(NLEFT, i))
}
else if (tag == NDMOD)
{
call newnod (nodes, frelst, inode1)
nodes(NTAG, inode1) = NDMOD + STAGE2
call push (xstack, ixstck, inode1)
call push (xstack, ixstck, nodes(NRIGHT, i))
call push (xstack, ixstck, nodes(NLEFT, i))
}
else if (tag == NDLT)
{
call newnod (nodes, frelst, inode1)
nodes(NTAG, inode1) = NDLT + STAGE2
call push (xstack, ixstck, inode1)
call push (xstack, ixstck, nodes(NRIGHT, i))
call push (xstack, ixstck, nodes(NLEFT, i))
}
else if (tag == NDLE)
{
call newnod (nodes, frelst, inode1)
nodes(NTAG, inode1) = NDLE + STAGE2
call push (xstack, ixstck, inode1)
call push (xstack, ixstck, nodes(NRIGHT, i))
call push (xstack, ixstck, nodes(NLEFT, i))
}
else if (tag == NDGT)
{
call newnod (nodes, frelst, inode1)
nodes(NTAG, inode1) = NDGT + STAGE2
call push (xstack, ixstck, inode1)
call push (xstack, ixstck, nodes(NRIGHT, i))
call push (xstack, ixstck, nodes(NLEFT, i))
}
else if (tag == NDGE)
{
call newnod (nodes, frelst, inode1)
nodes(NTAG, inode1) = NDGE + STAGE2
call push (xstack, ixstck, inode1)
call push (xstack, ixstck, nodes(NRIGHT, i))
call push (xstack, ixstck, nodes(NLEFT, i))
}
else if (tag == NDEQ)
{
call newnod (nodes, frelst, inode1)
nodes(NTAG, inode1) = NDEQ + STAGE2
call push (xstack, ixstck, inode1)
call push (xstack, ixstck, nodes(NRIGHT, i))
call push (xstack, ixstck, nodes(NLEFT, i))
}
else if (tag == NDNE)
{
call newnod (nodes, frelst, inode1)
nodes(NTAG, inode1) = NDNE + STAGE2
call push (xstack, ixstck, inode1)
call push (xstack, ixstck, nodes(NRIGHT, i))
call push (xstack, ixstck, nodes(NLEFT, i))
}
else if (tag == NDASGN)
{
call newnod (nodes, frelst, inode1)
nodes(NTAG, inode1) = NDASGN + STAGE2
nodes(NITV, inode1) = nodes(NITV, nodes(NLEFT, i))
nodes(NITN, inode1) = nodes(NITN, nodes(NLEFT, i))
call push (xstack, ixstck, inode1)
call push (xstack, ixstck, nodes(NRIGHT, i))
}
else if (tag == NDPRTS)
{
i0 = nodes(NITV, nodes(NLEFT, i))
n0 = nodes(NITN, nodes(NLEFT, i))
ivar = fndstr (strs, numstr, strngs, istrng, i0, n0)
ivar = strs(STRNO, ivar)
call put5 (code, ncode, ncode, OPPUSH, ivar)
call put1 (code, ncode, ncode, OPPRTS)
}
else if (tag == NDPRTC)
{
call newnod (nodes, frelst, inode1)
nodes(NTAG, inode1) = NDPRTC + STAGE2
call push (xstack, ixstck, inode1)
call push (xstack, ixstck, nodes(NLEFT, i))
}
else if (tag == NDPRTI)
{
call newnod (nodes, frelst, inode1)
nodes(NTAG, inode1) = NDPRTI + STAGE2
call push (xstack, ixstck, inode1)
call push (xstack, ixstck, nodes(NLEFT, i))
}
else if (tag == NDWHIL)
{
call newnod (nodes, frelst, inode1)
nodes(NTAG, inode1) = NDWHIL + STAGE2
nodes(NLEFT, inode1) = nodes(NRIGHT, i) # Loop body.
nodes(NRIGHT, inode1) = ncode # Addr. of top of loop.
call push (xstack, ixstck, inode1)
call push (xstack, ixstck, nodes(NLEFT, i))
}
else if (tag == NDIF)
{
call newnod (nodes, frelst, inode1)
nodes(NTAG, inode1) = NDIF + STAGE2
# The "then" and "else" clauses, respectively:
nodes(NLEFT, inode1) = nodes(NLEFT, nodes(NRIGHT, i))
nodes(NRIGHT, inode1) = nodes(NRIGHT, nodes(NRIGHT, i))
call push (xstack, ixstck, inode1)
call push (xstack, ixstck, nodes(NLEFT, i))
}
}
else
{
if (tag == NDNEG + STAGE2)
{
call frenod (nodes, frelst, i)
call put1 (code, ncode, ncode, OPNEG)
}
else if (tag == NDNOT + STAGE2)
{
call frenod (nodes, frelst, i)
call put1 (code, ncode, ncode, OPNOT)
}
else if (tag == NDAND + STAGE2)
{
call frenod (nodes, frelst, i)
call put1 (code, ncode, ncode, OPAND)
}
else if (tag == NDOR + STAGE2)
{
call frenod (nodes, frelst, i)
call put1 (code, ncode, ncode, OPOR)
}
else if (tag == NDADD + STAGE2)
{
call frenod (nodes, frelst, i)
call put1 (code, ncode, ncode, OPADD)
}
else if (tag == NDSUB + STAGE2)
{
call frenod (nodes, frelst, i)
call put1 (code, ncode, ncode, OPSUB)
}
else if (tag == NDMUL + STAGE2)
{
call frenod (nodes, frelst, i)
call put1 (code, ncode, ncode, OPMUL)
}
else if (tag == NDDIV + STAGE2)
{
call frenod (nodes, frelst, i)
call put1 (code, ncode, ncode, OPDIV)
}
else if (tag == NDMOD + STAGE2)
{
call frenod (nodes, frelst, i)
call put1 (code, ncode, ncode, OPMOD)
}
else if (tag == NDLT + STAGE2)
{
call frenod (nodes, frelst, i)
call put1 (code, ncode, ncode, OPLT)
}
else if (tag == NDLE + STAGE2)
{
call frenod (nodes, frelst, i)
call put1 (code, ncode, ncode, OPLE)
}
else if (tag == NDGT + STAGE2)
{
call frenod (nodes, frelst, i)
call put1 (code, ncode, ncode, OPGT)
}
else if (tag == NDGE + STAGE2)
{
call frenod (nodes, frelst, i)
call put1 (code, ncode, ncode, OPGE)
}
else if (tag == NDEQ + STAGE2)
{
call frenod (nodes, frelst, i)
call put1 (code, ncode, ncode, OPEQ)
}
else if (tag == NDNE + STAGE2)
{
call frenod (nodes, frelst, i)
call put1 (code, ncode, ncode, OPNE)
}
else if (tag == NDASGN + STAGE2)
{
i0 = nodes(NITV, i)
n0 = nodes(NITN, i)
call frenod (nodes, frelst, i)
ivar = fndvar (vars, numvar, strngs, istrng, i0, n0)
ivar = vars(VVALUE, ivar)
call put5 (code, ncode, ncode, OPSTOR, ivar)
}
else if (tag == NDPRTC + STAGE2)
{
call frenod (nodes, frelst, i)
call put1 (code, ncode, ncode, OPPRTC)
}
else if (tag == NDPRTI + STAGE2)
{
call frenod (nodes, frelst, i)
call put1 (code, ncode, ncode, OPPRTI)
}
else if (tag == NDWHIL + STAGE2)
{
inode1 = nodes(NLEFT, i) # Loop body.
addr1 = nodes(NRIGHT, i) # Addr. of top of loop.
call frenod (nodes, frelst, i)
call put5 (code, ncode, ncode, OPJZ, 0)
call newnod (nodes, frelst, inode2)
nodes(NTAG, inode2) = NDWHIL + STAGE3
nodes(NLEFT, inode2) = addr1 # Top of loop.
nodes(NRIGHT, inode2) = ncode - 4 # Fixup address.
call push (xstack, ixstck, inode2)
call push (xstack, ixstck, inode1)
}
else if (tag == NDWHIL + STAGE3)
{
addr1 = nodes(NLEFT, i) # Top of loop.
addr2 = nodes(NRIGHT, i) # Fixup address.
call frenod (nodes, frelst, i)
call put5 (code, ncode, ncode, OPJMP, addr1)
code(addr2) = ncode
}
else if (tag == NDIF + STAGE2)
{
inode1 = nodes(NLEFT, i) # "Then" clause.
inode2 = nodes(NRIGHT, i) # "Else" clause.
call frenod (nodes, frelst, i)
call put5 (code, ncode, ncode, OPJZ, 0)
call newnod (nodes, frelst, inode3)
nodes(NTAG, inode3) = NDIF + STAGE3
nodes(NLEFT, inode3) = ncode - 4 # Fixup address.
nodes(NRIGHT, inode3) = inode2 # "Else" clause.
call push (xstack, ixstck, inode3)
call push (xstack, ixstck, inode1)
}
else if (tag == NDIF + STAGE3)
{
addr1 = nodes(NLEFT, i) # Fixup address.
inode1 = nodes(NRIGHT, i) # "Else" clause.
call frenod (nodes, frelst, i)
if (inode2 == NIL)
code(addr1) = ncode
else
{
call put5 (code, ncode, ncode, OPJMP, 0)
addr2 = ncode - 4 # Another fixup address.
code(addr1) = ncode
call newnod (nodes, frelst, inode2)
nodes(NTAG, inode2) = NDIF + STAGE4
nodes(NLEFT, inode2) = addr2
call push (xstack, ixstck, inode2)
call push (xstack, ixstck, inode1)
}
}
else if (tag == NDIF + STAGE4)
{
addr1 = nodes(NLEFT, i) # Fixup address.
call frenod (nodes, frelst, i)
code(addr1) = ncode
}
}
}
call put1 (code, ncode, ncode, OPHALT)
end
 
function opname (opcode)
 
implicit none
 
integer opcode
character*8 opname
 
if (opcode == OPHALT)
opname = 'halt '
else if (opcode == OPADD)
opname = 'add '
else if (opcode == OPSUB)
opname = 'sub '
else if (opcode == OPMUL)
opname = 'mul '
else if (opcode == OPDIV)
opname = 'div '
else if (opcode == OPMOD)
opname = 'mod '
else if (opcode == OPLT)
opname = 'lt '
else if (opcode == OPGT)
opname = 'gt '
else if (opcode == OPLE)
opname = 'le '
else if (opcode == OPGE)
opname = 'ge '
else if (opcode == OPEQ)
opname = 'eq '
else if (opcode == OPNE)
opname = 'ne '
else if (opcode == OPAND)
opname = 'and '
else if (opcode == OPOR)
opname = 'or '
else if (opcode == OPNEG)
opname = 'neg '
else if (opcode == OPNOT)
opname = 'not '
else if (opcode == OPPRTC)
opname = 'prtc '
else if (opcode == OPPRTI)
opname = 'prti '
else if (opcode == OPPRTS)
opname = 'prts '
else if (opcode == OPFTCH)
opname = 'fetch '
else if (opcode == OPSTOR)
opname = 'store '
else if (opcode == OPPUSH)
opname = 'push '
else if (opcode == OPJMP)
opname = 'jmp '
else if (opcode == OPJZ)
opname = 'jz '
else
{
write (*, '(''Unrecognized opcode: '', I5)') opcode
stop
}
end
 
subroutine prprog (numvar, strs, numstr, strngs, istrng, _
code, ncode, outbuf, noutbf)
 
implicit none
 
integer numvar # Number of variables.
integer strs(STRSZ, MAXSTR) # Strings for the VM's string pool.
integer numstr # Number of such strings.
character strngs(STRNSZ) # String pool.
integer istrng # String pool's next slot.
integer code(0 : CODESZ - 1) # Generated code.
integer ncode # Number of VM bytes in the code.
character outbuf(OUTLSZ) # Output line buffer.
integer noutbf # Number of characters in outbuf.
 
character*8 opname
 
integer i0, n0
integer i, j
integer opcode
character*8 name
 
character buf(20)
buf(1) = 'D'
buf(2) = 'a'
buf(3) = 't'
buf(4) = 'a'
buf(5) = 's'
buf(6) = 'i'
buf(7) = 'z'
buf(8) = 'e'
buf(9) = ':'
buf(10) = ' '
call wrtstr (outbuf, noutbf, buf, 1, 10)
call wrtint (outbuf, noutbf, numvar, 0)
buf(1) = ' '
buf(2) = 'S'
buf(3) = 't'
buf(4) = 'r'
buf(5) = 'i'
buf(6) = 'n'
buf(7) = 'g'
buf(8) = 's'
buf(9) = ':'
buf(10) = ' '
call wrtstr (outbuf, noutbf, buf, 1, 10)
call wrtint (outbuf, noutbf, numstr, 0)
call wrtchr (outbuf, noutbf, char (NEWLIN))
 
for (i = 1; i <= numstr; i = i + 1)
{
i0 = strs(STRI, i)
n0 = strs(STRN, i)
call wrtstr (outbuf, noutbf, strngs, i0, n0)
call wrtchr (outbuf, noutbf, char (NEWLIN))
}
 
i = 0
while (i != ncode)
{
opcode = code(i)
name = opname (opcode)
call wrtint (outbuf, noutbf, i, 10)
for (j = 1; j <= 2; j = j + 1)
call wrtchr (outbuf, noutbf, ' ')
for (j = 1; j <= 8; j = j + 1)
{
if (opcode == OPFTCH _
|| opcode == OPSTOR _
|| opcode == OPPUSH _
|| opcode == OPJMP _
|| opcode == OPJZ)
call wrtchr (outbuf, noutbf, name(j:j))
else if (name(j:j) != ' ')
call wrtchr (outbuf, noutbf, name(j:j))
}
if (opcode == OPPUSH)
{
call wrtint (outbuf, noutbf, code(i + 1), 0)
i = i + 5
}
else if (opcode == OPFTCH || opcode == OPSTOR)
{
call wrtchr (outbuf, noutbf, '[')
call wrtint (outbuf, noutbf, code(i + 1), 0)
call wrtchr (outbuf, noutbf, ']')
i = i + 5
}
else if (opcode == OPJMP || opcode == OPJZ)
{
call wrtchr (outbuf, noutbf, '(')
call wrtint (outbuf, noutbf, code(i + 1) - (i + 1), 0)
call wrtchr (outbuf, noutbf, ')')
call wrtchr (outbuf, noutbf, ' ')
call wrtint (outbuf, noutbf, code(i + 1), 0)
i = i + 5
}
else
i = i + 1
call wrtchr (outbuf, noutbf, char (NEWLIN))
}
end
 
#---------------------------------------------------------------------
 
program gen
 
implicit none
 
integer vars(VARSZ, MAXVAR) # Variables.
integer numvar # Number of variables.
integer strs(STRSZ, MAXSTR) # Strings for the VM's string pool.
integer numstr # Number of such strings.
character strngs(STRNSZ) # String pool.
integer istrng # String pool's next slot.
integer nodes (NODESZ, NODSSZ) # Nodes pool.
integer frelst # Head of the free list.
character outbuf(OUTLSZ) # Output line buffer.
integer noutbf # Number of characters in outbuf.
integer code(0 : CODESZ - 1) # Generated code.
integer ncode # Number of VM bytes in the code.
integer iast # Root node of the AST.
 
numvar = 0
numstr = 0
istrng = 1
noutbf = 0
ncode = 0
 
call initnd (nodes, frelst)
call rdast (strngs, istrng, nodes, frelst, iast)
 
call compil (vars, numvar, strs, numstr, _
strngs, istrng, nodes, frelst, _
code, ncode, iast)
call prprog (numvar, strs, numstr, strngs, istrng, _
code, ncode, outbuf, noutbf)
 
if (noutbf != 0)
call flushl (outbuf, noutbf)
end
 
######################################################################</syntaxhighlight>
 
{{out}}
<pre>$ ratfor77 gen-in-ratfor.r > gen-in-ratfor.f && gfortran -fcheck=all -std=legacy -O2 gen-in-ratfor.f && ./a.out < compiler-tests/primes.ast
Datasize: 5 Strings: 3
" is prime\n"
"Total primes found: "
"\n"
0 push 1
5 store [0]
10 push 1
15 store [1]
20 push 100
25 store [2]
30 fetch [1]
35 fetch [2]
40 lt
41 jz (160) 202
46 push 3
51 store [3]
56 push 1
61 store [4]
66 fetch [1]
71 push 2
76 add
77 store [1]
82 fetch [3]
87 fetch [3]
92 mul
93 fetch [1]
98 le
99 fetch [4]
104 and
105 jz (53) 159
110 fetch [1]
115 fetch [3]
120 div
121 fetch [3]
126 mul
127 fetch [1]
132 ne
133 store [4]
138 fetch [3]
143 push 2
148 add
149 store [3]
154 jmp (-73) 82
159 fetch [4]
164 jz (32) 197
169 fetch [1]
174 prti
175 push 0
180 prts
181 fetch [0]
186 push 1
191 add
192 store [0]
197 jmp (-168) 30
202 push 1
207 prts
208 fetch [0]
213 prti
214 push 2
219 prts
220 halt</pre>
 
 
=={{header|Scala}}==
The complete implementation for the compiler tasks can be found in a GitHub repository at [https://github.com/edadma/rosettacodeCompiler github.com/edadma/rosettacodeCompiler] which includes full unit testing for the samples given in [[Compiler/Sample programs]].
 
The following code implements a code generator for the output of the [http://rosettacode.org/wiki/Compiler/syntax_analyzer#Scala parser].
 
<syntaxhighlight lang="scala">
package xyz.hyperreal.rosettacodeCompiler
 
import scala.collection.mutable.{ArrayBuffer, HashMap}
import scala.io.Source
 
object CodeGenerator {
 
def fromStdin = fromSource(Source.stdin)
 
def fromString(src: String) = fromSource(Source.fromString(src))
 
def fromSource(ast: Source) = {
val vars = new HashMap[String, Int]
val strings = new ArrayBuffer[String]
val code = new ArrayBuffer[String]
var s: Stream[String] = ast.getLines.toStream
 
def line =
if (s.nonEmpty) {
val n = s.head
 
s = s.tail
 
n.split(" +", 2) match {
case Array(n) => n
case a => a
}
} else
sys.error("unexpected end of AST")
 
def variableIndex(name: String) =
vars get name match {
case None =>
val idx = vars.size
 
vars(name) = idx
idx
case Some(idx) => idx
}
 
def stringIndex(s: String) =
strings indexOf s match {
case -1 =>
val idx = strings.length
 
strings += s
idx
case idx => idx
}
 
var loc = 0
 
def addSimple(inst: String) = {
code += f"$loc%4d $inst"
loc += 1
}
 
def addOperand(inst: String, operand: String) = {
code += f"$loc%4d $inst%-5s $operand"
loc += 5
}
 
def fixup(inst: String, idx: Int, at: Int) = code(idx) = f"$at%4d $inst%-5s (${loc - at - 1}) $loc"
 
generate
addSimple("halt")
println(s"Datasize: ${vars.size} Strings: ${strings.length}")
 
for (s <- strings)
println(s)
 
println(code mkString "\n")
 
def generate: Unit =
line match {
case "Sequence" =>
generate
generate
case ";" =>
case "Assign" =>
val idx =
line match {
case Array("Identifier", name: String) =>
variableIndex(name)
case l => sys.error(s"expected identifier: $l")
}
 
generate
addOperand("store", s"[$idx]")
case Array("Identifier", name: String) => addOperand("fetch", s"[${variableIndex(name)}]")
case Array("Integer", n: String) => addOperand("push", s"$n")
case Array("String", s: String) => addOperand("push", s"${stringIndex(s)}")
case "If" =>
generate
 
val cond = loc
val condidx = code.length
 
addOperand("", "")
s = s.tail
generate
 
if (s.head == ";") {
s = s.tail
fixup("jz", condidx, cond)
} else {
val jump = loc
val jumpidx = code.length
 
addOperand("", "")
fixup("jz", condidx, cond)
generate
fixup("jmp", jumpidx, jump)
}
case "While" =>
val start = loc
 
generate
 
val cond = loc
val condidx = code.length
 
addOperand("", "")
generate
addOperand("jmp", s"(${start - loc - 1}) $start")
fixup("jz", condidx, cond)
case op =>
generate
generate
addSimple(
op match {
case "Prti" => "prti"
case "Prts" => "prts"
case "Prtc" => "prtc"
case "Add" => "add"
case "Subtract" => "sub"
case "Multiply" => "mul"
case "Divide" => "div"
case "Mod" => "mod"
case "Less" => "lt"
case "LessEqual" => "le"
case "Greater" => "gt"
case "GreaterEqual" => "ge"
case "Equal" => "eq"
case "NotEqual" => "ne"
case "And" => "and"
case "Or" => "or"
case "Negate" => "neg"
case "Not" => "not"
}
)
}
}
 
}
</syntaxhighlight>
 
=={{header|Scheme}}==
 
<syntaxhighlight lang="scheme">
(import (scheme base)
(scheme file)
(scheme process-context)
(scheme write)
(only (srfi 1) delete-duplicates list-index)
(only (srfi 13) string-delete string-index string-trim))
 
(define *names* '((Add add) (Subtract sub) (Multiply mul) (Divide div) (Mod mod)
(Less lt) (Greater gt) (LessEqual le) (GreaterEqual ge)
(Equal eq) (NotEqual ne) (And and) (Or or) (Negate neg)
(Not not) (Prts prts) (Prti prti) (Prtc prtc)))
 
(define (change-name name)
(if (assq name *names*)
(cdr (assq name *names*))
(error "Cannot find name" name)))
 
;; Read AST from given filename
;; - return as an s-expression
(define (read-code filename)
(define (read-expr)
(let ((line (string-trim (read-line))))
(if (string=? line ";")
'()
(let ((space (string-index line #\space)))
(if space
(list (string->symbol (string-trim (substring line 0 space)))
(string-trim (substring line space (string-length line))))
(list (string->symbol line) (read-expr) (read-expr)))))))
;
(with-input-from-file filename (lambda () (read-expr))))
 
;; run a three-pass assembler
(define (generate-code ast)
(define new-address ; create a new unique address - for jump locations
(let ((count 0))
(lambda ()
(set! count (+ 1 count))
(string->symbol (string-append "loc-" (number->string count))))))
; define some names for fields
(define left cadr)
(define right (lambda (x) (cadr (cdr x))))
;
(define (extract-values ast)
(if (null? ast)
(values '() '())
(case (car ast)
((Integer)
(values '() '()))
((Negate Not Prtc Prti Prts)
(extract-values (left ast)))
((Assign Add Subtract Multiply Divide Mod Less Greater LessEqual GreaterEqual
Equal NotEqual And Or If While Sequence)
(let-values (((a b) (extract-values (left ast)))
((c d) (extract-values (right ast))))
(values (delete-duplicates (append a c) string=?)
(delete-duplicates (append b d) string=?))))
((String)
(values '() (list (left ast))))
((Identifier)
(values (list (left ast)) '())))))
;
(let-values (((constants strings) (extract-values ast)))
(define (constant-idx term)
(list-index (lambda (s) (string=? s term)) constants))
(define (string-idx term)
(list-index (lambda (s) (string=? s term)) strings))
;
(define (pass-1 ast asm) ; translates ast into a list of basic operations
(if (null? ast)
asm
(case (car ast)
((Integer)
(cons (list 'push (left ast)) asm))
((Identifier)
(cons (list 'fetch (constant-idx (left ast))) asm))
((String)
(cons (list 'push (string-idx (left ast))) asm))
((Assign)
(cons (list 'store (constant-idx (left (left ast)))) (pass-1 (right ast) asm)))
((Add Subtract Multiply Divide Mod Less Greater LessEqual GreaterEqual
Equal NotEqual And Or) ; binary operators
(cons (change-name (car ast))
(pass-1 (right ast) (pass-1 (left ast) asm))))
((Negate Not Prtc Prti Prts) ; unary operations
(cons (change-name (car ast))
(pass-1 (left ast) asm)))
((If)
(let ((label-else (new-address))
(label-end (new-address)))
(if (null? (right (right ast)))
(cons (list 'label label-end) ; label for end of if statement
(pass-1 (left (right ast)) ; output the 'then block
(cons (list 'jz label-end) ; jump to end when test is false
(pass-1 (left ast) asm))))
(cons (list 'label label-end) ; label for end of if statement
(pass-1 (right (right ast)) ; output the 'else block
(cons (list 'label label-else)
(cons (list 'jmp label-end) ; jump past 'else, after 'then
(pass-1 (left (right ast)) ; output the 'then block
(cons (list 'jz label-else) ; jumpt to else when false
(pass-1 (left ast) asm))))))))))
((While)
(let ((label-test (new-address))
(label-end (new-address)))
(cons (list 'label label-end) ; introduce a label for end of while block
(cons (list 'jmp label-test) ; jump back to repeat test
(pass-1 (right ast) ; output the block
(cons (list 'jz label-end) ; test failed, jump around block
(pass-1 (left ast) ; output the test
(cons (list 'label label-test) ; introduce a label for test
asm))))))))
((Sequence)
(pass-1 (right ast) (pass-1 (left ast) asm)))
(else
"Unknown token type"))))
;
(define (pass-2 asm) ; adds addresses and fills in jump locations
(define (fill-addresses)
(let ((addr 0))
(map (lambda (instr)
(let ((res (cons addr instr)))
(unless (eq? (car instr) 'label)
(set! addr (+ addr (if (= 1 (length instr)) 1 5))))
res))
asm)))
;
(define (extract-labels asm)
(let ((labels '()))
(for-each (lambda (instr)
(when (eq? (cadr instr) 'label)
(set! labels (cons (cons (cadr (cdr instr)) (car instr))
labels))))
asm)
labels))
;
(define (add-jump-locations asm labels rec)
(cond ((null? asm)
(reverse rec))
((eq? (cadr (car asm)) 'label) ; ignore the labels
(add-jump-locations (cdr asm) labels rec))
((memq (cadr (car asm)) '(jmp jz)) ; replace labels with addresses for jumps
(add-jump-locations (cdr asm)
labels
(cons (list (car (car asm)) ; previous address
(cadr (car asm)) ; previous jump type
(cdr (assq (cadr (cdar asm)) labels))) ; actual address
rec)))
(else
(add-jump-locations (cdr asm) labels (cons (car asm) rec)))))
;
(let ((asm+addr (fill-addresses)))
(add-jump-locations asm+addr (extract-labels asm+addr) '())))
;
(define (output-instruction instr)
(display (number->string (car instr))) (display #\tab)
(display (cadr instr)) (display #\tab)
(case (cadr instr)
((fetch store)
(display "[") (display (number->string (cadr (cdr instr)))) (display "]\n"))
((jmp jz)
(display
(string-append "("
(number->string (- (cadr (cdr instr)) (car instr) 1))
")"))
(display #\tab)
(display (number->string (cadr (cdr instr)))) (newline))
((push)
(display (cadr (cdr instr))) (newline))
(else
(newline))))
; generate the code and output to stdout
(display
(string-append "Datasize: "
(number->string (length constants))
" Strings: "
(number->string (length strings))))
(newline)
(for-each (lambda (str) (display str) (newline))
strings)
(for-each output-instruction
(pass-2 (reverse (cons (list 'halt) (pass-1 ast '())))))))
 
;; read AST from file and output code to stdout
(if (= 2 (length (command-line)))
(generate-code (read-code (cadr (command-line))))
(display "Error: pass an ast filename\n"))
</syntaxhighlight>
 
Tested on all examples in [[Compiler/Sample programs]].
 
=={{header|Wren}}==
{{trans|Go}}
{{libheader|Wren-dynamic}}
{{libheader|Wren-crypto}}
{{libheader|Wren-fmt}}
{{libheader|Wren-ioutil}}
<syntaxhighlight lang="wren">import "./dynamic" for Enum, Struct, Tuple
import "./crypto" for Bytes
import "./fmt" for Fmt
import "./ioutil" for FileUtil
 
var nodes = [
"Ident",
"String",
"Integer",
"Sequence",
"If",
"Prtc",
"Prts",
"Prti",
"While",
"Assign",
"Negate",
"Not",
"Mul",
"Div",
"Mod",
"Add",
"Sub",
"Lss",
"Leq",
"Gtr",
"Geq",
"Eql",
"Neq",
"And",
"Or"
]
 
var Node = Enum.create("Node", nodes)
 
var codes = [
"fetch",
"store",
"push",
"add",
"sub",
"mul",
"div",
"mod",
"lt",
"gt",
"le",
"ge",
"eq",
"ne",
"and",
"or",
"neg",
"not",
"jmp",
"jz",
"prtc",
"prts",
"prti",
"halt"
]
 
var Code = Enum.create("Code", codes)
 
var Tree = Struct.create("Tree", ["nodeType", "left", "right", "value"])
 
// dependency: Ordered by Node value, must remain in same order as Node enum
var Atr = Tuple.create("Atr", ["enumText", "nodeType", "opcode"])
 
var atrs = [
Atr.new("Identifier", Node.Ident, 255),
Atr.new("String", Node.String, 255),
Atr.new("Integer", Node.Integer, 255),
Atr.new("Sequence", Node.Sequence, 255),
Atr.new("If", Node.If, 255),
Atr.new("Prtc", Node.Prtc, 255),
Atr.new("Prts", Node.Prts, 255),
Atr.new("Prti", Node.Prti, 255),
Atr.new("While", Node.While, 255),
Atr.new("Assign", Node.Assign, 255),
Atr.new("Negate", Node.Negate, Code.neg),
Atr.new("Not", Node.Not, Code.not),
Atr.new("Multiply", Node.Mul, Code.mul),
Atr.new("Divide", Node.Div, Code.div),
Atr.new("Mod", Node.Mod, Code.mod),
Atr.new("Add", Node.Add, Code.add),
Atr.new("Subtract", Node.Sub, Code.sub),
Atr.new("Less", Node.Lss, Code.lt),
Atr.new("LessEqual", Node.Leq, Code.le),
Atr.new("Greater", Node.Gtr, Code.gt),
Atr.new("GreaterEqual", Node.Geq, Code.ge),
Atr.new("Equal", Node.Eql, Code.eq),
Atr.new("NotEqual", Node.Neq, Code.ne),
Atr.new("And", Node.And, Code.and),
Atr.new("Or", Node.Or, Code.or),
]
 
var stringPool = []
var globals = []
var object = []
 
var reportError = Fn.new { |msg| Fiber.abort("error : %(msg)") }
 
var nodeToOp = Fn.new { |nodeType| atrs[nodeType].opcode }
 
var makeNode = Fn.new { |nodeType, left, right| Tree.new(nodeType, left, right, "") }
 
var makeLeaf = Fn.new { |nodeType, value| Tree.new(nodeType, null, null, value) }
 
/* Code generator */
 
var emitByte = Fn.new { |c| object.add(c) }
 
var emitWord = Fn.new { |n|
var bs = Bytes.fromIntLE(n)
for (b in bs) emitByte.call(b)
}
 
var emitWordAt = Fn.new { |at, n|
var bs = Bytes.fromIntLE(n)
for (i in at...at+4) object[i] = bs[i-at]
}
 
var hole = Fn.new {
var t = object.count
emitWord.call(0)
return t
}
 
var fetchVarOffset = Fn.new { |id|
for (i in 0...globals.count) {
if (globals[i] == id) return i
}
globals.add(id)
return globals.count - 1
}
 
var fetchStringOffset = Fn.new { |st|
for (i in 0...stringPool.count) {
if (stringPool[i] == st) return i
}
stringPool.add(st)
return stringPool.count - 1
}
 
var binOpNodes = [
Node.Lss, Node.Gtr, Node.Leq, Node.Geq, Node.Eql, Node.Neq,
Node.And, Node.Or, Node.Sub, Node.Add, Node.Div, Node.Mul, Node.Mod
]
 
var codeGen // recursive function
codeGen = Fn.new { |x|
if (!x) return
var n
var p1
var p2
var nt = x.nodeType
if (nt == Node.Ident) {
emitByte.call(Code.fetch)
n = fetchVarOffset.call(x.value)
emitWord.call(n)
} else if (nt == Node.Integer) {
emitByte.call(Code.push)
n = Num.fromString(x.value)
emitWord.call(n)
} else if (nt == Node.String) {
emitByte.call(Code.push)
n = fetchStringOffset.call(x.value)
emitWord.call(n)
} else if (nt == Node.Assign) {
n = fetchVarOffset.call(x.left.value)
codeGen.call(x.right)
emitByte.call(Code.store)
emitWord.call(n)
} else if (nt == Node.If) {
codeGen.call(x.left) // if expr
emitByte.call(Code.jz) // if false, jump
p1 = hole.call() // make room forjump dest
codeGen.call(x.right.left) // if true statements
if (x.right.right) {
emitByte.call(Code.jmp)
p2 = hole.call()
}
emitWordAt.call(p1, object.count-p1)
if (x.right.right) {
codeGen.call(x.right.right)
emitWordAt.call(p2, object.count-p2)
}
} else if (nt == Node.While) {
p1 = object.count
codeGen.call(x.left) // while expr
emitByte.call(Code.jz) // if false, jump
p2 = hole.call() // make room for jump dest
codeGen.call(x.right) // statements
emitByte.call(Code.jmp) // back to the top
emitWord.call(p1 - object.count) // plug the top
emitWordAt.call(p2, object.count-p2) // plug the 'if false, jump'
} else if (nt == Node.Sequence) {
codeGen.call(x.left)
codeGen.call(x.right)
} else if (nt == Node.Prtc) {
codeGen.call(x.left)
emitByte.call(Code.prtc)
} else if (nt == Node.Prti) {
codeGen.call(x.left)
emitByte.call(Code.prti)
} else if (nt == Node.Prts) {
codeGen.call(x.left)
emitByte.call(Code.prts)
} else if (binOpNodes.contains(nt)) {
codeGen.call(x.left)
codeGen.call(x.right)
emitByte.call(nodeToOp.call(x.nodeType))
} else if (nt == Node.negate || nt == Node.Not) {
codeGen.call(x.left)
emitByte.call(nodeToOp.call(x.nodeType))
} else {
var msg = "error in code generator - found %(x.nodeType) expecting operator"
reportError.call(msg)
}
}
 
// Converts the 4 bytes starting at object[pc] to an unsigned 32 bit integer
// and thence to a signed 32 bit integer
var toInt32LE = Fn.new { |pc|
var x = Bytes.toIntLE(object[pc...pc+4])
if (x >= 2.pow(31)) x = x - 2.pow(32)
return x
}
 
var codeFinish = Fn.new { emitByte.call(Code.halt) }
 
var listCode = Fn.new {
Fmt.print("Datasize: $d Strings: $d", globals.count, stringPool.count)
for (s in stringPool) System.print(s)
var pc = 0
while (pc < object.count) {
Fmt.write("$5d ", pc)
var op = object[pc]
pc = pc + 1
if (op == Code.fetch) {
var x = toInt32LE.call(pc)
Fmt.print("fetch [$d]", x)
pc = pc + 4
} else if (op == Code.store) {
var x = toInt32LE.call(pc)
Fmt.print("store [$d]", x)
pc = pc + 4
} else if (op == Code.push) {
var x = toInt32LE.call(pc)
Fmt.print("push $d", x)
pc = pc + 4
} else if (op == Code.add) {
System.print("add")
} else if (op == Code.sub) {
System.print("sub")
} else if (op == Code.mul) {
System.print("mul")
} else if (op == Code.div) {
System.print("div")
} else if (op == Code.mod) {
System.print("mod")
} else if (op == Code.lt) {
System.print("lt")
} else if (op == Code.gt) {
System.print("gt")
} else if (op == Code.le) {
System.print("le")
} else if (op == Code.ge) {
System.print("ge")
} else if (op == Code.eq) {
System.print("eq")
} else if (op == Code.ne) {
System.print("ne")
} else if (op == Code.and) {
System.print("and")
} else if (op == Code.or) {
System.print("or")
} else if (op == Code.neg) {
System.print("neg")
} else if (op == Code.not) {
System.print("not")
} else if (op == Code.jmp) {
var x = toInt32LE.call(pc)
Fmt.print("jmp ($d) $d", x, pc+x)
pc = pc + 4
} else if (op == Code.jz) {
var x = toInt32LE.call(pc)
Fmt.print("jz ($d) $d", x, pc+x)
pc = pc + 4
} else if (op == Code.prtc) {
System.print("prtc")
} else if (op == Code.prti){
System.print("prti")
} else if (op == Code.prts) {
System.print("prts")
} else if (op == Code.halt) {
System.print("halt")
} else {
reportError.call("listCode: Unknown opcode %(op)")
}
}
}
 
var getEnumValue = Fn.new { |name|
for (atr in atrs) {
if (atr.enumText == name) return atr.nodeType
}
reportError.call("Unknown token %(name)")
}
 
var lines = []
var lineCount = 0
var lineNum = 0
 
var loadAst // recursive function
loadAst = Fn.new {
var nodeType = 0
var s = ""
if (lineNum < lineCount) {
var line = lines[lineNum].trimEnd(" \t")
lineNum = lineNum + 1
var tokens = line.split(" ").where { |s| s != "" }.toList
var first = tokens[0]
if (first[0] == ";") return null
nodeType = getEnumValue.call(first)
var le = tokens.count
if (le == 2) {
s = tokens[1]
} else if (le > 2) {
var idx = line.indexOf("\"")
s = line[idx..-1]
}
}
if (s != "") return makeLeaf.call(nodeType, s)
var left = loadAst.call()
var right = loadAst.call()
return makeNode.call(nodeType, left, right)
}
 
lines = FileUtil.readLines("ast.txt")
lineCount = lines.count
codeGen.call(loadAst.call())
codeFinish.call()
listCode.call()</syntaxhighlight>
 
{{out}}
<pre>
Datasize: 1 Strings: 2
"count is: "
"\n"
0 push 1
5 store [0]
10 fetch [0]
15 push 10
20 lt
21 jz (43) 65
26 push 0
31 prts
32 fetch [0]
37 prti
38 push 1
43 prts
44 fetch [0]
49 push 1
54 add
55 store [0]
60 jmp (-51) 10
65 halt
</pre>
 
=={{header|Zig}}==
<syntaxhighlight lang="zig">
const std = @import("std");
 
pub const CodeGeneratorError = error{OutOfMemory};
 
pub const CodeGenerator = struct {
allocator: std.mem.Allocator,
string_pool: std.ArrayList([]const u8),
globals: std.ArrayList([]const u8),
bytecode: std.ArrayList(u8),
 
const Self = @This();
const word_size = @sizeOf(i32);
 
pub fn init(
allocator: std.mem.Allocator,
string_pool: std.ArrayList([]const u8),
globals: std.ArrayList([]const u8),
) Self {
return CodeGenerator{
.allocator = allocator,
.string_pool = string_pool,
.globals = globals,
.bytecode = std.ArrayList(u8).init(allocator),
};
}
 
pub fn gen(self: *Self, ast: ?*Tree) CodeGeneratorError!void {
try self.genH(ast);
try self.emitHalt();
}
 
// Helper function to allow recursion.
pub fn genH(self: *Self, ast: ?*Tree) CodeGeneratorError!void {
if (ast) |t| {
switch (t.typ) {
.sequence => {
try self.genH(t.left);
try self.genH(t.right);
},
.kw_while => {
const condition_address = self.currentAddress();
try self.genH(t.left);
try self.emitByte(.jz);
const condition_address_hole = self.currentAddress();
try self.emitHole();
try self.genH(t.right);
try self.emitByte(.jmp);
try self.emitInt(condition_address);
self.insertInt(condition_address_hole, self.currentAddress());
},
.kw_if => {
try self.genH(t.left);
try self.emitByte(.jz);
const condition_address_hole = self.currentAddress();
try self.emitHole();
try self.genH(t.right.?.left);
if (t.right.?.right) |else_tree| {
try self.emitByte(.jmp);
const else_address_hole = self.currentAddress();
try self.emitHole();
const else_address = self.currentAddress();
try self.genH(else_tree);
self.insertInt(condition_address_hole, else_address);
self.insertInt(else_address_hole, self.currentAddress());
} else {
self.insertInt(condition_address_hole, self.currentAddress());
}
},
.assign => {
try self.genH(t.right);
try self.emitByte(.store);
try self.emitInt(self.fetchGlobalsOffset(t.left.?.value.?.string));
},
.prts => {
try self.genH(t.left);
try self.emitByte(.prts);
},
.prti => {
try self.genH(t.left);
try self.emitByte(.prti);
},
.prtc => {
try self.genH(t.left);
try self.emitByte(.prtc);
},
.string => {
try self.emitByte(.push);
try self.emitInt(self.fetchStringsOffset(t.value.?.string));
},
.integer => {
try self.emitByte(.push);
try self.emitInt(t.value.?.integer);
},
.identifier => {
try self.emitByte(.fetch);
try self.emitInt(self.fetchGlobalsOffset(t.value.?.string));
},
.negate, .not => {
try self.genH(t.left);
try self.emitByte(Op.fromNodeType(t.typ).?);
},
.add,
.multiply,
.subtract,
.divide,
.mod,
.less,
.less_equal,
.greater,
.greater_equal,
.equal,
.not_equal,
.bool_and,
.bool_or,
=> try self.genBinOp(t),
.unknown => {
std.debug.print("\nINTERP: UNKNOWN {}\n", .{t.typ});
std.os.exit(1);
},
}
}
}
 
fn genBinOp(self: *Self, tree: *Tree) CodeGeneratorError!void {
try self.genH(tree.left);
try self.genH(tree.right);
try self.emitByte(Op.fromNodeType(tree.typ).?);
}
 
fn emitByte(self: *Self, op: Op) CodeGeneratorError!void {
try self.bytecode.append(@enumToInt(op));
}
 
fn emitInt(self: *Self, n: i32) CodeGeneratorError!void {
var n_var = n;
var n_bytes = @ptrCast(*[4]u8, &n_var);
for (n_bytes) |byte| {
try self.bytecode.append(byte);
}
}
 
// Holes are later populated via `insertInt` because they can't be known when
// we populate the bytecode array sequentially.
fn emitHole(self: *Self) CodeGeneratorError!void {
try self.emitInt(std.math.maxInt(i32));
}
 
// Populates the "hole" produced by `emitHole`.
fn insertInt(self: *Self, address: i32, n: i32) void {
var i: i32 = 0;
var n_var = n;
var n_bytes = @ptrCast(*[4]u8, &n_var);
while (i < word_size) : (i += 1) {
self.bytecode.items[@intCast(usize, address + i)] = n_bytes[@intCast(usize, i)];
}
}
 
fn emitHalt(self: *Self) CodeGeneratorError!void {
try self.bytecode.append(@enumToInt(Op.halt));
}
 
fn currentAddress(self: Self) i32 {
return @intCast(i32, self.bytecode.items.len);
}
 
fn fetchStringsOffset(self: Self, str: []const u8) i32 {
for (self.string_pool.items) |string, idx| {
if (std.mem.eql(u8, string, str)) {
return @intCast(i32, idx);
}
}
unreachable;
}
 
fn fetchGlobalsOffset(self: Self, str: []const u8) i32 {
for (self.globals.items) |global, idx| {
if (std.mem.eql(u8, global, str)) {
return @intCast(i32, idx);
}
}
unreachable;
}
 
pub fn print(self: Self) ![]u8 {
var result = std.ArrayList(u8).init(self.allocator);
var writer = result.writer();
try writer.print(
"Datasize: {d} Strings: {d}\n",
.{ self.globals.items.len, self.string_pool.items.len },
);
for (self.string_pool.items) |string| {
try writer.print("{s}\n", .{string});
}
 
var pc: usize = 0;
while (pc < self.bytecode.items.len) : (pc += 1) {
try writer.print("{d:>5} ", .{pc});
switch (@intToEnum(Op, self.bytecode.items[pc])) {
.push => {
try writer.print("push {d}\n", .{self.unpackInt(pc + 1)});
pc += word_size;
},
.store => {
try writer.print("store [{d}]\n", .{self.unpackInt(pc + 1)});
pc += word_size;
},
.fetch => {
try writer.print("fetch [{d}]\n", .{self.unpackInt(pc + 1)});
pc += word_size;
},
.jz => {
const address = self.unpackInt(pc + 1);
try writer.print("jz ({d}) {d}\n", .{ address - @intCast(i32, pc) - 1, address });
pc += word_size;
},
.jmp => {
const address = self.unpackInt(pc + 1);
try writer.print("jmp ({d}) {d}\n", .{ address - @intCast(i32, pc) - 1, address });
pc += word_size;
},
else => try writer.print("{s}\n", .{Op.toString(@intToEnum(Op, self.bytecode.items[pc]))}),
}
}
 
return result.items;
}
 
fn unpackInt(self: Self, pc: usize) i32 {
const arg_ptr = @ptrCast(*[4]u8, self.bytecode.items[pc .. pc + word_size]);
var arg_array = arg_ptr.*;
const arg = @ptrCast(*i32, @alignCast(@alignOf(i32), &arg_array));
return arg.*;
}
};
 
pub const Op = enum(u8) {
fetch,
store,
push,
add,
sub,
mul,
div,
mod,
lt,
gt,
le,
ge,
eq,
ne,
@"and",
@"or",
neg,
not,
jmp,
jz,
prtc,
prts,
prti,
halt,
 
const from_node = std.enums.directEnumArray(NodeType, ?Op, 0, .{
.unknown = null,
.identifier = null,
.string = null,
.integer = null,
.sequence = null,
.kw_if = null,
.prtc = null,
.prts = null,
.prti = null,
.kw_while = null,
.assign = null,
.negate = .neg,
.not = .not,
.multiply = .mul,
.divide = .div,
.mod = .mod,
.add = .add,
.subtract = .sub,
.less = .lt,
.less_equal = .le,
.greater = .gt,
.greater_equal = .ge,
.equal = .eq,
.not_equal = .ne,
.bool_and = .@"and",
.bool_or = .@"or",
});
 
pub fn fromNodeType(node_type: NodeType) ?Op {
return from_node[@enumToInt(node_type)];
}
 
const to_string = std.enums.directEnumArray(Op, []const u8, 0, .{
.fetch = "fetch",
.store = "store",
.push = "push",
.add = "add",
.sub = "sub",
.mul = "mul",
.div = "div",
.mod = "mod",
.lt = "lt",
.gt = "gt",
.le = "le",
.ge = "ge",
.eq = "eq",
.ne = "ne",
.@"and" = "and",
.@"or" = "or",
.neg = "neg",
.not = "not",
.jmp = "jmp",
.jz = "jz",
.prtc = "prtc",
.prts = "prts",
.prti = "prti",
.halt = "halt",
});
 
pub fn toString(self: Op) []const u8 {
return to_string[@enumToInt(self)];
}
};
 
pub fn main() !void {
var arena = std.heap.ArenaAllocator.init(std.heap.page_allocator);
defer arena.deinit();
const allocator = arena.allocator();
 
var arg_it = std.process.args();
_ = try arg_it.next(allocator) orelse unreachable; // program name
const file_name = arg_it.next(allocator);
// We accept both files and standard input.
var file_handle = blk: {
if (file_name) |file_name_delimited| {
const fname: []const u8 = try file_name_delimited;
break :blk try std.fs.cwd().openFile(fname, .{});
} else {
break :blk std.io.getStdIn();
}
};
defer file_handle.close();
const input_content = try file_handle.readToEndAlloc(allocator, std.math.maxInt(usize));
 
var string_pool = std.ArrayList([]const u8).init(allocator);
var globals = std.ArrayList([]const u8).init(allocator);
const ast = try loadAST(allocator, input_content, &string_pool, &globals);
var code_generator = CodeGenerator.init(allocator, string_pool, globals);
try code_generator.gen(ast);
const result: []const u8 = try code_generator.print();
_ = try std.io.getStdOut().write(result);
}
 
pub const NodeType = enum {
unknown,
identifier,
string,
integer,
sequence,
kw_if,
prtc,
prts,
prti,
kw_while,
assign,
negate,
not,
multiply,
divide,
mod,
add,
subtract,
less,
less_equal,
greater,
greater_equal,
equal,
not_equal,
bool_and,
bool_or,
 
const from_string_map = std.ComptimeStringMap(NodeType, .{
.{ "UNKNOWN", .unknown },
.{ "Identifier", .identifier },
.{ "String", .string },
.{ "Integer", .integer },
.{ "Sequence", .sequence },
.{ "If", .kw_if },
.{ "Prtc", .prtc },
.{ "Prts", .prts },
.{ "Prti", .prti },
.{ "While", .kw_while },
.{ "Assign", .assign },
.{ "Negate", .negate },
.{ "Not", .not },
.{ "Multiply", .multiply },
.{ "Divide", .divide },
.{ "Mod", .mod },
.{ "Add", .add },
.{ "Subtract", .subtract },
.{ "Less", .less },
.{ "LessEqual", .less_equal },
.{ "Greater", .greater },
.{ "GreaterEqual", .greater_equal },
.{ "Equal", .equal },
.{ "NotEqual", .not_equal },
.{ "And", .bool_and },
.{ "Or", .bool_or },
});
 
pub fn fromString(str: []const u8) NodeType {
return from_string_map.get(str).?;
}
};
 
pub const NodeValue = union(enum) {
integer: i32,
string: []const u8,
};
 
pub const Tree = struct {
left: ?*Tree,
right: ?*Tree,
typ: NodeType = .unknown,
value: ?NodeValue = null,
 
fn makeNode(allocator: std.mem.Allocator, typ: NodeType, left: ?*Tree, right: ?*Tree) !*Tree {
const result = try allocator.create(Tree);
result.* = Tree{ .left = left, .right = right, .typ = typ };
return result;
}
 
fn makeLeaf(allocator: std.mem.Allocator, typ: NodeType, value: ?NodeValue) !*Tree {
const result = try allocator.create(Tree);
result.* = Tree{ .left = null, .right = null, .typ = typ, .value = value };
return result;
}
};
 
const LoadASTError = error{OutOfMemory} || std.fmt.ParseIntError;
 
fn loadAST(
allocator: std.mem.Allocator,
str: []const u8,
string_pool: *std.ArrayList([]const u8),
globals: *std.ArrayList([]const u8),
) LoadASTError!?*Tree {
var line_it = std.mem.split(u8, str, "\n");
return try loadASTHelper(allocator, &line_it, string_pool, globals);
}
 
fn loadASTHelper(
allocator: std.mem.Allocator,
line_it: *std.mem.SplitIterator(u8),
string_pool: *std.ArrayList([]const u8),
globals: *std.ArrayList([]const u8),
) LoadASTError!?*Tree {
if (line_it.next()) |line| {
var tok_it = std.mem.tokenize(u8, line, " ");
const tok_str = tok_it.next().?;
if (tok_str[0] == ';') return null;
 
const node_type = NodeType.fromString(tok_str);
const pre_iteration_index = tok_it.index;
 
if (tok_it.next()) |leaf_value| {
const node_value = blk: {
switch (node_type) {
.integer => break :blk NodeValue{ .integer = try std.fmt.parseInt(i32, leaf_value, 10) },
.identifier => {
var already_exists = false;
for (globals.items) |global| {
if (std.mem.eql(u8, global, leaf_value)) {
already_exists = true;
break;
}
}
if (!already_exists) try globals.append(leaf_value);
break :blk NodeValue{ .string = leaf_value };
},
.string => {
tok_it.index = pre_iteration_index;
const str = tok_it.rest();
var already_exists = false;
for (string_pool.items) |string| {
if (std.mem.eql(u8, string, str)) {
already_exists = true;
break;
}
}
if (!already_exists) try string_pool.append(str);
break :blk NodeValue{ .string = str };
},
else => unreachable,
}
};
return try Tree.makeLeaf(allocator, node_type, node_value);
}
 
const left = try loadASTHelper(allocator, line_it, string_pool, globals);
const right = try loadASTHelper(allocator, line_it, string_pool, globals);
return try Tree.makeNode(allocator, node_type, left, right);
} else {
return null;
}
}
</syntaxhighlight>
 
=={{header|zkl}}==
{{trans|Python}}
<langsyntaxhighlight lang="zkl">// This is a little endian machine
 
const WORD_SIZE=4;
Line 2,049 ⟶ 11,113:
code.insert(0,66,text.len(),text);
})
}</langsyntaxhighlight>
<langsyntaxhighlight lang="zkl">fcn unasm(code){
all_ops,nthString := all_syms.pump(Dictionary(),"reverse"),-1;
println("Datasize: %d bytes, Strings: %d bytes"
Line 2,084 ⟶ 11,148:
}
}
}</langsyntaxhighlight>
<langsyntaxhighlight lang="zkl">fcn load_ast(file){
line:=file.readln().strip(); // one or two tokens
if(line[0]==";") return(Void);
Line 2,096 ⟶ 11,160:
left,right := load_ast(file),load_ast(file);
Node(type,Void,left,right)
}</langsyntaxhighlight>
<langsyntaxhighlight lang="zkl">ast:=load_ast(File(vm.nthArg(0)));
code:=asm(ast,Data());
code_finish(code);
unasm(code);
File("code.bin","wb").write(code);
println("Wrote %d bytes to code.bin".fmt(code.len()));</langsyntaxhighlight>
File ast.txt is the text at the start of this task.
{{out}}
9,483

edits