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From: Hui Zhu <teawater@gmail.com>
To: gdb@sourceware.org
Subject: Does gdb can handle longjmp in i386 and amd64 now?
Date: Wed, 02 Sep 2009 14:22:00 -0000	[thread overview]
Message-ID: <daef60380909020722t72006cadi1e43beefc2a9441e@mail.gmail.com> (raw)

Hi guys,

I try the following code with gdb in i386 and amd64:
#include   <setjmp.h>
#include   <stdio.h>
jmp_buf j;

void
raise_exception (void)
{
	//printf ("exception   raised\n");
	longjmp (j, 1);		/*   jump   to   exception   handler   */
	printf ("this   line   should   never   appear\n");
}

int
main (void)
{
	if (setjmp (j) == 0)
	{
		printf ("''setjmp''   is   initializing   ''j''\n");
		raise_exception ();
		printf ("this   line   should   never   appear\n");
	}
	else
	{
		printf ("''setjmp''   was   just   jumped   into\n");
		/*   this   code   is   the   exception   handler   */
	}

	return 0;
}


In i386, what I got is:

(gdb) start
Temporary breakpoint 1 at 0x80483ff: file 1.c, line 16.
Starting program: /home/teawater/gdb/a.out

Temporary breakpoint 1, main () at 1.c:16
16		if (setjmp (j) == 0)
(gdb) s
18			printf ("''setjmp''   is   initializing   ''j''\n");
(gdb) s
''setjmp''   is   initializing   ''j''
19			raise_exception ();
(gdb)
raise_exception () at 1.c:9
9		longjmp (j, 1);		/*   jump   to   exception   handler   */
(gdb)
0xb7ea3e61 in siglongjmp () from /lib/tls/i686/cmov/libc.so.6
(gdb) s
Single stepping until exit from function siglongjmp,
which has no line number information.
''setjmp''   was   just   jumped   into

Program exited normally.



In amd64, what I got is:
(gdb) start
Temporary breakpoint 1 at 0x4005c3: file 1.c, line 16.
Starting program: /home/teawater/gdb/a.out

Temporary breakpoint 1, main () at 1.c:16
warning: Source file is more recent than executable.
16		if (setjmp (j) == 0)
(gdb) s
18			printf ("''setjmp''   is   initializing   ''j''\n");
(gdb) s
''setjmp''   is   initializing   ''j''
19			raise_exception ();
(gdb)
raise_exception () at 1.c:9
9		longjmp (j, 1);		/*   jump   to   exception   handler   */
(gdb)
''setjmp''   was   just   jumped   into

Program exited normally.


Are this right?

Thanks,
Hui


             reply	other threads:[~2009-09-02 14:22 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-09-02 14:22 Hui Zhu [this message]
2009-09-02 15:12 ` Tom Tromey
2009-09-02 15:17   ` Mark Kettenis
2009-09-02 15:22     ` Tom Tromey
2009-09-03  1:44       ` Hui Zhu

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