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Where I can find setjmp,longjmp, sigsetjmp implementation? In GCC source I
can't find.

Użytkownik "Borneq" <> napisał w wiadomości
news:ka75r3$66s$...
> Where I can find setjmp,longjmp, sigsetjmp implementation? In GCC source I
> can't find.

I found one:
https://www-asim.lip6.fr/trac/netbsd...v=3&order=name

Użytkownik "Borneq" <> napisał w wiadomości
news:ka76g3$6v1$...
> I found one:
> https://www-asim.lip6.fr/trac/netbsd...v=3&order=name

Is setjmp but not longjmp

Borneq wrote:

> Where I can find setjmp, longjmp, sigsetjmp implementation?

e.g. http://sourceware.org/git/?p=glibc.git;a=tree;f=setjmp

Uzytkownik "Noob" <root@127.0.0.1> napisal w wiadomosci
news:ka7744$178$...
>> Where I can find setjmp, longjmp, sigsetjmp implementation?
>
> e.g. http://sourceware.org/git/?p=glibc.git;a=tree;f=setjmp

This call low level functions, longjmp.c :

#include <setjmp.h>
void
__libc_siglongjmp (sigjmp_buf env, int val)
{
/* Perform any cleanups needed by the frames being unwound. */
_longjmp_unwind (env, val);

if (env[0].__mask_was_saved)
/* Restore the saved signal mask. */
(void) __sigprocmask (SIG_SETMASK, &env[0].__saved_mask,
(sigset_t *) NULL);

/* Call the machine-dependent function to restore machine state. */
__longjmp (env[0].__jmpbuf, val ?: 1);
}

longjmp_unwind ,__sigprocmask, __longjmp are in other library? In assembly?

Borneq wrote:

> longjmp_unwind, __sigprocmask, __longjmp are in other library?

1) tar xjf glibc-2.16.0.tar.bz2
2) grep -rn __longjmp glibc-2.16.0

e.g. http://sourceware.org/git/?p=glibc.g...86/__longjmp.S

Uzytkownik "Noob" <root@127.0.0.1> napisal w wiadomosci
news:ka7b08$n4m$...
> Borneq wrote:
>
>> longjmp_unwind, __sigprocmask, __longjmp are in other library?
>
> 1) tar xjf glibc-2.16.0.tar.bz2
> 2) grep -rn __longjmp glibc-2.16.0
>
> e.g.
> http://sourceware.org/git/?p=glibc.g...86/__longjmp.S

Thanks

"Noob" <root@127.0.0.1> wrote in message news:ka7b08$n4m$...
> Borneq wrote:
>
>> longjmp_unwind, __sigprocmask, __longjmp are in other library?
>
> 1) tar xjf glibc-2.16.0.tar.bz2
> 2) grep -rn __longjmp glibc-2.16.0
>
> e.g.
> http://sourceware.org/git/?p=glibc.g...86/__longjmp.S

This is not C. In that case why does it need to be that complicated? I used
to do this in just 3 instructions:

mov esp,[spsave]
mov ebp,[bpsave]
jmp [....]

It worked.

--
Bartc

BartC wrote:
>
>
> "Noob" <root@127.0.0.1> wrote in message news:ka7b08$n4m$...
>> Borneq wrote:
>>
>>> longjmp_unwind, __sigprocmask, __longjmp are in other library?
>>
>> 1) tar xjf glibc-2.16.0.tar.bz2
>> 2) grep -rn __longjmp glibc-2.16.0
>>
>> e.g.
>> http://sourceware.org/git/?p=glibc.g...86/__longjmp.S
>
> This is not C. In that case why does it need to be that complicated? I
> used to do this in just 3 instructions:
>
> mov esp,[spsave]
> mov ebp,[bpsave]
> jmp [....]
>
> It worked.
>

Doesn't the whole machine state have to be
saved/restored(registers/Fp/SSE/flags etc)? What if the calling function
was using some regs for local vars etc ?!...

On Wed, 12 Dec 2012 15:19:57 +0100, Johann Klammer wrote:

> Doesn't the whole machine state have to be
> saved/restored(registers/Fp/SSE/flags etc)?

No.

> What if the calling function was using some regs for local vars etc ?!...

7.13.2.1p3:

All accessible objects have values as of the time longjmp was
called, except that the values of objects of automatic storage
duration that are local to the function containing the
invocation of the corresponding setjmp macro that do not have
volatile-qualified type and have been changed between the
setjmp invocation and longjmp call are indeterminate.

gcc will warn about such cases with e.g.:

warning: variable ‘foo’ might be clobbered by ‘longjmp’ or ‘vfork’

Typically, only the "essential" registers (program counter, stack pointer,
frame pointer) are preserved. Registers holding local variables or
intermediate results aren't required to be preserved (and usually aren't).
"Global" state isn't modified by longjmp and, AIUI, that includes the FP
environment (<fenv.h>).