Cristian Baboi wrote:
Hello!
Hi Cristian!
This is my first try to use the C interface of gambit-c. I used gambit-c 4.2.8 and mingw gcc compiler from CodeBlocks under Windows XP.
Running alt.exe, I get: Hello World! from C begin 137end
The lines printed from the C function appear before the lines printed by scheme. I have two questions:
- Why the output lines do not appear in the call order ?
I guess you solved your problem, by looking at your 2nd email.
- Is this the correct way to get small executables with gambit-c or it
can be done in a better way ?
I'm not sure about the size of the executable, but I can give you some tips on compiling scheme programs and writing ffi. ;)
functii.c
#include <string.h> #include <stdio.h>
int hello(char * s){ printf("%s",s); return strlen(s); }
I believe that this file is not required. You could get rid of it and only use scm file instead ^_^.
test.scm
(c-declare #<<c-declare-end extern int hello(char *s);
/* You could either put directly your definition of hello here, but I would also get rid of hello if I was you and do instead: */ #include <stdio.h>
c-declare-end )
(c-define-type MyInt int) (c-define-type MyString char-string)
;;this is not necessary, but I guess you knew it already hehe
(define myHello (c-lambda (MyString) MyInt "hello" ))
;;then here you could have: (define printf (c-lambda (char-string char-string) void "printf")) (define (myHello str) (printf "%s" str) (string-length str))
;; the alt.scm can remain the same
alt.scm
(display "begin") (newline) (display (myHello "Hello World!\n")) (display (myHello "from C\n")) (display "end") (newline)
To compile in linux and run the program I usually do: dave@david /tmp $ gsc -c -o test.c test.scm dave@david /tmp $ gsc -c -o alt.c alt.scm dave@david /tmp $ gsc -link -o alt_.c test.c alt.c dave@david /tmp $ gcc -I/opt/gambit-c/current/include -o alt.exe test.c alt.c alt_.c -L/opt/gambit-c/current/lib -lgambc -lutil -lm -ldl dave@david /tmp $ ./alt.exe begin Hello World! 13from C 7end
You would just need to change to compile flags to match thoses required by windows (-lws2_32, etc...). Again, I don't know if this results in the smallest executable but this is the way I compile my scheme program into executables (I usually compile the .c to .o seperately, but this does not change much).
I hope I could help you a bit!
David
PS: I attached to source code file I compiled