Call a foreign-language function: Difference between revisions

=={{header|Forth}}

{{works with|GNU Forth|0.7.0}}

Every version of GNU Forth has experimented with a different means to do C foreign function calls. The current implementation resolves various incompatibilities which had plagued earlier mechanisms by parsing C header files and using the host's native toolchain (i.e. gcc and ld) to generate thunks.

<lang forth>

c-library cstrings

\c #include <string.h>

c-function strdup strdup a -- a ( c-string -- duped string )

c-function strlen strlen a -- n ( c-string -- length )

end-c-library

\ convenience function (not used here)

: c-string ( addr u -- addr' )

tuck pad swap move pad + 0 swap c! pad ;

create test s" testing" mem, 0 c,

test strdup value duped

test .

test 7 type \ testing

cr

duped . \ different address

duped dup strlen type \ testing

duped free throw \ gforth ALLOCATE and FREE map directly to C's malloc() and free()

</lang>