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/* Compiled and run by foreign-stack-alignment.lisp
*
* stack_alignment_offset(int) returns the offset of the first argument from a
* given alignment. run (1) from main, to obtain the good value with no
* lisp involved (2) from lisp both with and without callbacks to see that
* we have not messed the alignment.
*
* trampoline(int(*)()) is here so that we can get callbacks on the
* stack too.
*/
/* This software is part of the SBCL system. See the README file for
* more information.
*
* While most of SBCL is derived from the CMU CL system, the test
* files (like this one) were written from scratch after the fork
* from CMU CL.
*
* This software is in the public domain and is provided with
* absolutely no warranty. See the COPYING and CREDITS files for
* more information.
*/
#include <stdio.h>
#include <stdint.h> // for uintptr_t
#include <stdlib.h> // for atoi
/* <nikodemus> bwahahahaaa!
* <Xophe> oh dear. He's finally flipped
* <lisppaste> nikodemus pasted "stack_alignment_offset" at
* http://paste.lisp.org/display/13231
* <Xophe> heh
* <Xophe> along with a big / * This code is really twisted * / comment :-)
* <antifuchs> gods.
*/
extern int
stack_alignment_offset (int alignment)
{
return ((unsigned int)(uintptr_t)&alignment) % alignment;
}
extern int
trampoline (int(*callback)(void))
{
return callback();
}
int main (int argc, char** argv)
{
if (argc != 2) {
printf("wrong number of arguments: %d\n", argc-1);
return 1;
}
printf("%d\n", stack_alignment_offset(atoi(argv[1])));
return 0;
}
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