https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117267
Stas Sergeev <stsp at users dot sourceforge.net> changed:
What |Removed |Added
----------------------------------------------------------------------------
Resolution|INVALID |---
Status|RESOLVED |NEW
--- Comment #10 from Stas Sergeev <stsp at users dot sourceforge.net> ---
Yes, that seems to work, thanks.
But this doesn't mean there is no
bug. Here's the updated test-case:
---
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <ucontext.h>
typedef struct __jmp_buf {
void *buf[5];
} jmp_buf[1];
static ucontext_t uc;
__attribute__((noinline))
static int setjmp(jmp_buf env)
{
int rc = __builtin_setjmp(env[0].buf);
if (rc)
setcontext(&uc);
return rc;
}
static jmp_buf jb;
static void foo(void)
{
printf("before jump\n");
__builtin_longjmp(jb[0].buf, 1);
}
static void bar(void)
{
printf("swapcontext worked\n");
exit(0);
}
int main(void)
{
if (setjmp(jb))
printf("Jumped\n");
else {
getcontext(&uc);
uc.uc_stack.ss_sp = malloc(8192);
uc.uc_stack.ss_size = 8192;
makecontext(&uc, bar, 0);
foo();
}
return 0;
}
---
The idea is to leave the setjmp()
uninlined and recover the stack
with swapcontext().
It works properly w/o optimization,
but generates bad code (shown in prev
msg) with -O2. clang generates the
correct code with any -O.
