[Bug c/26294] New: va_list passing breaks on x86-64 only

[ian-gccbug at penguinhosting dot net]

The following works on i386, sparc32 and sparc64, but produces a compiler
warning on x86-64, then prints garbage and crashses when run:

---------------------------
#include <stdarg.h>
#include <stdio.h>

void func3(va_list *ap) {
        int test = va_arg(*ap,int);
        fprintf(stderr,"%d\n",test);
}

void func2(va_list ap) {
        func3(&ap);
}

void func1(int start, ...) {
        va_list ap;

        va_start(ap,start);

        func2(ap);

        va_end(ap);
}

int main() {
        fprintf(stderr,"This should print 1:\n");
        func1(2,1);
        return 0;
}
---------------------------
test.c: In function `func2':
test.c:10: warning: passing arg 1 of `func3' from incompatible pointer type
---------------------------
This should print 1:
-7609280
Segmentation fault


-- 
           Summary: va_list passing breaks on x86-64 only
           Product: gcc
           Version: 3.4.4
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: ian-gccbug at penguinhosting dot net
 GCC build triplet: x86_64-pc-linux-gnu
  GCC host triplet: x86_64-pc-linux-gnu
GCC target triplet: x86_64-pc-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26294