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<hr>
__TOC__
 
=={{header|Ada}}==
{{works with|GNAT|Community 2021}}
 
 
<lang Ada>--
-- The Rosetta Code Virtual Machine, in Ada.
--
-- It is assumed the platform on which this program is run
-- has two's-complement integers. (Otherwise one could modify
-- the vmint_to_vmsigned and vmsigned_to_vmint functions. But
-- the chances your binary integers are not two's-complement
-- seem pretty low.)
--
 
with Ada.Characters.Handling; use Ada.Characters.Handling;
with Ada.Command_Line; use Ada.Command_Line;
 
with Ada.Strings.Unbounded; use Ada.Strings.Unbounded;
with Ada.Strings.Unbounded.Text_IO; use Ada.Strings.Unbounded.Text_IO;
 
with Ada.Text_IO; use Ada.Text_IO;
with Ada.Text_IO.Text_Streams; use Ada.Text_IO.Text_Streams;
 
with Ada.Unchecked_Conversion;
 
procedure VM
is
bad_vm : exception;
vm_limit_exceeded : exception;
vm_runtime_error : exception;
 
status : Exit_Status;
input_file_name : Unbounded_String;
output_file_name : Unbounded_String;
input_file : File_Type;
output_file : File_Type;
 
-- Some limits of this implementation. You can adjust these to taste.
strings_size : constant := 2_048;
stack_size : constant := 2_048;
data_size : constant := 2_048;
code_size : constant := 32_768;
 
type byte is mod 16#100#;
type vmint is mod 16#1_0000_0000#;
subtype vmsigned is Integer range -2_147_483_648 .. 2_147_483_647;
 
op_halt : constant byte := 0;
op_add : constant byte := 1;
op_sub : constant byte := 2;
op_mul : constant byte := 3;
op_div : constant byte := 4;
op_mod : constant byte := 5;
op_lt : constant byte := 6;
op_gt : constant byte := 7;
op_le : constant byte := 8;
op_ge : constant byte := 9;
op_eq : constant byte := 10;
op_ne : constant byte := 11;
op_and : constant byte := 12;
op_or : constant byte := 13;
op_neg : constant byte := 14;
op_not : constant byte := 15;
op_prtc : constant byte := 16;
op_prti : constant byte := 17;
op_prts : constant byte := 18;
op_fetch : constant byte := 19;
op_store : constant byte := 20;
op_push : constant byte := 21;
op_jmp : constant byte := 22;
op_jz : constant byte := 23;
 
strings : array (0 .. strings_size - 1) of Unbounded_String;
stack : array (0 .. stack_size - 1) of vmint;
data : array (0 .. data_size - 1) of vmint;
code : array (0 .. code_size) of byte;
sp : vmint;
pc : vmint;
 
output_stream : Stream_Access;
 
function vmsigned_to_vmint is new Ada.Unchecked_Conversion
(Source => vmsigned, Target => vmint);
 
function vmint_to_vmsigned is new Ada.Unchecked_Conversion
(Source => vmint, Target => vmsigned);
 
function twos_complement
(x : in vmint)
return vmint
is
begin
return (not x) + 1;
end twos_complement;
 
function vmint_to_digits
(x : in vmint)
return Unbounded_String
is
s : Unbounded_String;
z : vmint;
begin
if x = 0 then
s := To_Unbounded_String ("0");
else
s := To_Unbounded_String ("");
z := x;
while z /= 0 loop
s := Character'Val ((z rem 10) + Character'Pos ('0')) & s;
z := z / 10;
end loop;
end if;
return s;
end vmint_to_digits;
 
function digits_to_vmint
(s : in String)
return vmint
is
zero : constant Character := '0';
zero_pos : constant Integer := Character'Pos (zero);
retval : vmint;
begin
if s'Length < 1 then
raise bad_vm with "expected a numeric literal";
end if;
retval := 0;
for i in s'Range loop
if Is_Decimal_Digit (s (i)) then
retval :=
(10 * retval) + vmint (Character'Pos (s (i)) - zero_pos);
else
raise bad_vm with "expected a decimal digit";
end if;
end loop;
return retval;
end digits_to_vmint;
 
function string_to_vmint
(s : in String)
return vmint
is
retval : vmint;
begin
if s'Length < 1 then
raise bad_vm with "expected a numeric literal";
end if;
if s (s'First) = '-' then
if s'Length < 2 then
raise bad_vm with "expected a numeric literal";
end if;
retval :=
twos_complement (digits_to_vmint (s (s'First + 1 .. s'Last)));
else
retval := digits_to_vmint (s);
end if;
return retval;
end string_to_vmint;
 
procedure parse_header
(s : in String;
data_count : out vmint;
strings_count : out vmint)
is
i : Positive;
j : Positive;
begin
i := s'First;
while i <= s'Last and then not Is_Decimal_Digit (s (i)) loop
i := i + 1;
end loop;
 
j := i;
while j <= s'Last and then Is_Decimal_Digit (s (j)) loop
j := j + 1;
end loop;
 
data_count := digits_to_vmint (s (i .. j - 1));
 
i := j;
while i <= s'Last and then not Is_Decimal_Digit (s (i)) loop
i := i + 1;
end loop;
 
j := i;
while j <= s'Last and then Is_Decimal_Digit (s (j)) loop
j := j + 1;
end loop;
 
strings_count := digits_to_vmint (s (i .. j - 1));
end parse_header;
 
function parse_string_literal
(s : in String)
return Unbounded_String
is
t : Unbounded_String;
i : Positive;
begin
t := To_Unbounded_String ("");
 
i := s'First;
while i <= s'Last and then s (i) /= '"' loop
i := i + 1;
end loop;
 
if s'Last < i or else s (i) /= '"' then
raise bad_vm with "expected a '""'";
end if;
 
i := i + 1;
while i <= s'Last and then s (i) /= '"' loop
if s (i) /= '\' then
Append (t, s (i));
i := i + 1;
elsif s'Last < i + 1 then
raise bad_vm with "truncated string literal";
elsif s (i + 1) = 'n' then
Append (t, Character'Val (10));
i := i + 2;
elsif s (i + 1) = '\' then
Append (t, '\');
i := i + 2;
else
raise bad_vm with "unsupported escape sequence";
end if;
end loop;
 
return t;
end parse_string_literal;
 
function name_to_opcode
(s : in String)
return byte
is
retval : byte;
begin
if s = "halt" then
retval := op_halt;
elsif s = "add" then
retval := op_add;
elsif s = "sub" then
retval := op_sub;
elsif s = "mul" then
retval := op_mul;
elsif s = "div" then
retval := op_div;
elsif s = "mod" then
retval := op_mod;
elsif s = "lt" then
retval := op_lt;
elsif s = "gt" then
retval := op_gt;
elsif s = "le" then
retval := op_le;
elsif s = "ge" then
retval := op_ge;
elsif s = "eq" then
retval := op_eq;
elsif s = "ne" then
retval := op_ne;
elsif s = "and" then
retval := op_and;
elsif s = "or" then
retval := op_or;
elsif s = "neg" then
retval := op_neg;
elsif s = "not" then
retval := op_not;
elsif s = "prtc" then
retval := op_prtc;
elsif s = "prti" then
retval := op_prti;
elsif s = "prts" then
retval := op_prts;
elsif s = "fetch" then
retval := op_fetch;
elsif s = "store" then
retval := op_store;
elsif s = "push" then
retval := op_push;
elsif s = "jmp" then
retval := op_jmp;
elsif s = "jz" then
retval := op_jz;
else
raise bad_vm with ("unexpected opcode name");
end if;
return retval;
end name_to_opcode;
 
procedure parse_instruction
(s : in String;
address : out vmint;
opcode : out byte;
arg : out vmint)
is
i : Positive;
j : Positive;
begin
i := s'First;
while i <= s'Last and then not Is_Decimal_Digit (s (i)) loop
i := i + 1;
end loop;
 
j := i;
while j <= s'Last and then Is_Decimal_Digit (s (j)) loop
j := j + 1;
end loop;
 
address := digits_to_vmint (s (i .. j - 1));
 
i := j;
while i <= s'Last and then not Is_Letter (s (i)) loop
i := i + 1;
end loop;
 
j := i;
while j <= s'Last and then Is_Letter (s (j)) loop
j := j + 1;
end loop;
 
opcode := name_to_opcode (s (i .. j - 1));
 
i := j;
while i <= s'Last and then Is_Space (s (i)) loop
i := i + 1;
end loop;
 
if s'Last < i then
arg := 0;
else
if not Is_Decimal_Digit (s (i)) and then s (i) /= '-' then
i := i + 1;
end if;
j := i;
while j <= s'Last
and then (Is_Decimal_Digit (s (j)) or else s (j) = '-')
loop
j := j + 1;
end loop;
arg := string_to_vmint (s (i .. j - 1));
end if;
end parse_instruction;
 
procedure read_and_parse_header
(data_count : out vmint;
strings_count : out vmint)
is
line : Unbounded_String;
begin
Get_Line (Current_Input, line);
parse_header (To_String (line), data_count, strings_count);
end read_and_parse_header;
 
procedure read_parse_and_store_strings
(strings_count : in vmint)
is
line : Unbounded_String;
begin
if strings_count /= 0 then
if strings_size < strings_count then
raise vm_limit_exceeded with "strings limit exceeded";
end if;
for i in 0 .. strings_count - 1 loop
Get_Line (Current_Input, line);
strings (Integer (i)) :=
parse_string_literal (To_String (line));
end loop;
end if;
end read_parse_and_store_strings;
 
function opcode_takes_arg
(opcode : in byte)
return Boolean
is
retval : Boolean;
begin
if opcode = op_fetch then
retval := True;
elsif opcode = op_store then
retval := True;
elsif opcode = op_push then
retval := True;
elsif opcode = op_jmp then
retval := True;
elsif opcode = op_jz then
retval := True;
else
retval := False;
end if;
return retval;
end opcode_takes_arg;
 
procedure read_parse_and_store_instructions
is
line : Unbounded_String;
address : vmint;
opcode : byte;
arg : vmint;
j : Positive;
begin
while not End_Of_File (Current_Input) loop
Get_Line (Current_Input, line);
 
j := 1;
while j <= Length (line) and then Is_Space (Element (line, j))
loop
j := j + 1;
end loop;
 
if j <= Length (line) then
parse_instruction (To_String (line), address, opcode, arg);
if opcode_takes_arg (opcode) then
if code_size - 4 <= address then
raise vm_limit_exceeded with "code space limit exceeded";
end if;
code (Integer (address)) := opcode;
--
-- Little-endian storage.
--
code (Integer (address) + 1) := byte (arg and 16#FF#);
code (Integer (address) + 2) :=
byte ((arg / 16#100#) and 16#FF#);
code (Integer (address) + 3) :=
byte ((arg / 16#1_0000#) and 16#FF#);
code (Integer (address) + 4) :=
byte ((arg / 16#100_0000#) and 16#FF#);
else
if code_size <= address then
raise vm_limit_exceeded with "code space limit exceeded";
end if;
code (Integer (address)) := opcode;
end if;
end if;
end loop;
end read_parse_and_store_instructions;
 
procedure read_parse_and_store_program
is
data_count : vmint;
strings_count : vmint;
begin
read_and_parse_header (data_count, strings_count);
read_parse_and_store_strings (strings_count);
read_parse_and_store_instructions;
end read_parse_and_store_program;
 
procedure pop_value
(x : out vmint)
is
begin
if sp = 0 then
raise vm_runtime_error with "stack underflow";
end if;
sp := sp - 1;
x := stack (Integer (sp));
end pop_value;
 
procedure push_value
(x : in vmint)
is
begin
if stack_size <= sp then
raise vm_runtime_error with "stack overflow";
end if;
stack (Integer (sp)) := x;
sp := sp + 1;
end push_value;
 
procedure get_value
(x : out vmint)
is
begin
if sp = 0 then
raise vm_runtime_error with "stack underflow";
end if;
x := stack (Integer (sp) - 1);
end get_value;
 
procedure put_value
(x : in vmint)
is
begin
if sp = 0 then
raise vm_runtime_error with "stack underflow";
end if;
stack (Integer (sp) - 1) := x;
end put_value;
 
procedure fetch_value
(i : in vmint;
x : out vmint)
is
begin
if data_size <= i then
raise vm_runtime_error with "data boundary exceeded";
end if;
x := data (Integer (i));
end fetch_value;
 
procedure store_value
(i : in vmint;
x : in vmint)
is
begin
if data_size <= i then
raise vm_runtime_error with "data boundary exceeded";
end if;
data (Integer (i)) := x;
end store_value;
 
procedure immediate_value
(x : out vmint)
is
b0, b1, b2, b3 : vmint;
begin
if code_size - 4 <= pc then
raise vm_runtime_error with "code boundary exceeded";
end if;
--
-- Little-endian order.
--
b0 := vmint (code (Integer (pc)));
b1 := vmint (code (Integer (pc) + 1));
b2 := vmint (code (Integer (pc) + 2));
b3 := vmint (code (Integer (pc) + 3));
x :=
b0 + (16#100# * b1) + (16#1_0000# * b2) + (16#100_0000# * b3);
end immediate_value;
 
procedure machine_add
is
x, y : vmint;
begin
pop_value (y);
get_value (x);
put_value (x + y);
end machine_add;
 
procedure machine_sub
is
x, y : vmint;
begin
pop_value (y);
get_value (x);
put_value (x - y);
end machine_sub;
 
procedure machine_mul
is
x, y : vmint;
begin
pop_value (y);
get_value (x);
put_value
(vmsigned_to_vmint
(vmint_to_vmsigned (x) * vmint_to_vmsigned (y)));
end machine_mul;
 
procedure machine_div
is
x, y : vmint;
begin
pop_value (y);
get_value (x);
put_value
(vmsigned_to_vmint
(vmint_to_vmsigned (x) / vmint_to_vmsigned (y)));
end machine_div;
 
procedure machine_mod
is
x, y : vmint;
begin
pop_value (y);
get_value (x);
put_value
(vmsigned_to_vmint
(vmint_to_vmsigned (x) rem vmint_to_vmsigned (y)));
end machine_mod;
 
procedure machine_lt
is
x, y : vmint;
begin
pop_value (y);
get_value (x);
if vmint_to_vmsigned (x) < vmint_to_vmsigned (y) then
put_value (1);
else
put_value (0);
end if;
end machine_lt;
 
procedure machine_gt
is
x, y : vmint;
begin
pop_value (y);
get_value (x);
if vmint_to_vmsigned (x) > vmint_to_vmsigned (y) then
put_value (1);
else
put_value (0);
end if;
end machine_gt;
 
procedure machine_le
is
x, y : vmint;
begin
pop_value (y);
get_value (x);
if vmint_to_vmsigned (x) <= vmint_to_vmsigned (y) then
put_value (1);
else
put_value (0);
end if;
end machine_le;
 
procedure machine_ge
is
x, y : vmint;
begin
pop_value (y);
get_value (x);
if vmint_to_vmsigned (x) >= vmint_to_vmsigned (y) then
put_value (1);
else
put_value (0);
end if;
end machine_ge;
 
procedure machine_eq
is
x, y : vmint;
begin
pop_value (y);
get_value (x);
if x = y then
put_value (1);
else
put_value (0);
end if;
end machine_eq;
 
procedure machine_ne
is
x, y : vmint;
begin
pop_value (y);
get_value (x);
if x /= y then
put_value (1);
else
put_value (0);
end if;
end machine_ne;
 
procedure machine_and
is
x, y : vmint;
begin
pop_value (y);
get_value (x);
if x /= 0 and y /= 0 then
put_value (1);
else
put_value (0);
end if;
end machine_and;
 
procedure machine_or
is
x, y : vmint;
begin
pop_value (y);
get_value (x);
if x /= 0 or y /= 0 then
put_value (1);
else
put_value (0);
end if;
end machine_or;
 
procedure machine_neg
is
x : vmint;
begin
get_value (x);
put_value (twos_complement (x));
end machine_neg;
 
procedure machine_not
is
x : vmint;
begin
get_value (x);
if x = 0 then
put_value (1);
else
put_value (0);
end if;
end machine_not;
 
procedure machine_prtc
is
x : vmint;
begin
pop_value (x);
Character'Write (output_stream, Character'Val (x));
end machine_prtc;
 
procedure machine_prti
is
x : vmint;
begin
pop_value (x);
if 16#7FFF_FFFF# < x then
Character'Write (output_stream, '-');
String'Write
(output_stream,
To_String (vmint_to_digits (twos_complement (x))));
else
String'Write (output_stream, To_String (vmint_to_digits (x)));
end if;
end machine_prti;
 
procedure machine_prts
is
k : vmint;
begin
pop_value (k);
if strings_size <= k then
raise vm_runtime_error with "strings boundary exceeded";
end if;
String'Write (output_stream, To_String (strings (Integer (k))));
end machine_prts;
 
procedure machine_fetch
is
k : vmint;
x : vmint;
begin
immediate_value (k);
fetch_value (k, x);
push_value (x);
pc := pc + 4;
end machine_fetch;
 
procedure machine_store
is
k : vmint;
x : vmint;
begin
immediate_value (k);
pop_value (x);
store_value (k, x);
pc := pc + 4;
end machine_store;
 
procedure machine_push
is
x : vmint;
begin
immediate_value (x);
push_value (x);
pc := pc + 4;
end machine_push;
 
procedure machine_jmp
is
offset : vmint;
begin
immediate_value (offset);
pc := pc + offset;
end machine_jmp;
 
procedure machine_jz
is
x : vmint;
offset : vmint;
begin
pop_value (x);
if x = 0 then
immediate_value (offset);
pc := pc + offset;
else
pc := pc + 4;
end if;
end machine_jz;
 
procedure machine_step
(halt : out Boolean)
is
opcode : byte;
op_div_4, op_rem_4 : byte;
begin
if code_size <= pc then
raise vm_runtime_error with "code boundary exceeded";
end if;
opcode := code (Integer (pc));
pc := pc + 1;
halt := False;
op_div_4 := opcode / 4;
op_rem_4 := opcode rem 4;
if op_div_4 = 0 then
if op_rem_4 = 0 then
halt := True;
elsif op_rem_4 = 1 then
machine_add;
elsif op_rem_4 = 2 then
machine_sub;
else
machine_mul;
end if;
elsif op_div_4 = 1 then
if op_rem_4 = 0 then
machine_div;
elsif op_rem_4 = 1 then
machine_mod;
elsif op_rem_4 = 2 then
machine_lt;
else
machine_gt;
end if;
elsif op_div_4 = 2 then
if op_rem_4 = 0 then
machine_le;
elsif op_rem_4 = 1 then
machine_ge;
elsif op_rem_4 = 2 then
machine_eq;
else
machine_ne;
end if;
elsif op_div_4 = 3 then
if op_rem_4 = 0 then
machine_and;
elsif op_rem_4 = 1 then
machine_or;
elsif op_rem_4 = 2 then
machine_neg;
else
machine_not;
end if;
elsif op_div_4 = 4 then
if op_rem_4 = 0 then
machine_prtc;
elsif op_rem_4 = 1 then
machine_prti;
elsif op_rem_4 = 2 then
machine_prts;
else
machine_fetch;
end if;
elsif op_div_4 = 5 then
if op_rem_4 = 0 then
machine_store;
elsif op_rem_4 = 1 then
machine_push;
elsif op_rem_4 = 2 then
machine_jmp;
else
machine_jz;
end if;
else
-- Treat anything unrecognized as equivalent to a halt.
halt := True;
end if;
end machine_step;
 
procedure machine_continue
is
halt : Boolean;
begin
halt := False;
while not halt loop
machine_step (halt);
end loop;
end machine_continue;
 
procedure machine_run
is
begin
sp := 0;
pc := 0;
for i in data'Range loop
data (i) := 0;
end loop;
machine_continue;
end machine_run;
 
begin
status := 0;
 
input_file_name := To_Unbounded_String ("-");
 
if Argument_Count = 0 then
null;
elsif Argument_Count = 1 then
input_file_name := To_Unbounded_String (Argument (1));
else
Put ("Usage: ");
Put (Command_Name);
Put_Line (" [INPUTFILE]");
Put ("If either INPUTFILE is missing or ""-"",");
Put_Line (" standard input is used.");
Put_Line ("Output is always to standard output.");
status := 1;
end if;
 
if status = 0 then
if input_file_name /= "-" then
Open (input_file, In_File, To_String (input_file_name));
Set_Input (input_file);
end if;
 
output_stream := Stream (Current_Output);
read_parse_and_store_program;
machine_run;
 
if input_file_name /= "-" then
Set_Input (Standard_Input);
Close (input_file);
end if;
end if;
 
Set_Exit_Status (status);
end VM;</lang>
 
 
{{out}}
<pre>$ gnatmake -q -gnatp -O3 -march=native vm.adb && ./vm compiler-tests/count.vm
count is: 1
count is: 2
count is: 3
count is: 4
count is: 5
count is: 6
count is: 7
count is: 8
count is: 9</pre>
 
 
 
 
 
=={{header|Aime}}==
Chemoelectric
1,448

edits

Retrieved from "https://rosettacode.org/wiki/Special:MobileDiff/271301"