* [Bug c/38167] Inline accessor to stdin is breaks on -O2 optimization
2008-11-17 2:00 [Bug c/38167] New: Inline accessor to stdin is breaks on -O2 optimization aleksi dot nurmi at helsinki dot fi
@ 2008-11-17 2:03 ` aleksi dot nurmi at helsinki dot fi
2008-11-17 8:47 ` jakub at gcc dot gnu dot org
` (7 subsequent siblings)
8 siblings, 0 replies; 10+ messages in thread
From: aleksi dot nurmi at helsinki dot fi @ 2008-11-17 2:03 UTC (permalink / raw)
To: gcc-bugs
------- Comment #1 from aleksi dot nurmi at helsinki dot fi 2008-11-17 02:01 -------
Created an attachment (id=16707)
--> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=16707&action=view)
preprocessed source
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38167
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Bug c/38167] Inline accessor to stdin is breaks on -O2 optimization
2008-11-17 2:00 [Bug c/38167] New: Inline accessor to stdin is breaks on -O2 optimization aleksi dot nurmi at helsinki dot fi
2008-11-17 2:03 ` [Bug c/38167] " aleksi dot nurmi at helsinki dot fi
@ 2008-11-17 8:47 ` jakub at gcc dot gnu dot org
2008-11-17 14:08 ` aleksi dot nurmi at helsinki dot fi
` (6 subsequent siblings)
8 siblings, 0 replies; 10+ messages in thread
From: jakub at gcc dot gnu dot org @ 2008-11-17 8:47 UTC (permalink / raw)
To: gcc-bugs
------- Comment #2 from jakub at gcc dot gnu dot org 2008-11-17 08:46 -------
Works just fine here, with both 4.3 and 4.4, -O2 and -O0.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38167
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Bug c/38167] Inline accessor to stdin is breaks on -O2 optimization
2008-11-17 2:00 [Bug c/38167] New: Inline accessor to stdin is breaks on -O2 optimization aleksi dot nurmi at helsinki dot fi
2008-11-17 2:03 ` [Bug c/38167] " aleksi dot nurmi at helsinki dot fi
2008-11-17 8:47 ` jakub at gcc dot gnu dot org
@ 2008-11-17 14:08 ` aleksi dot nurmi at helsinki dot fi
2008-11-17 15:12 ` [Bug c/38167] Accessor " aleksi dot nurmi at helsinki dot fi
` (5 subsequent siblings)
8 siblings, 0 replies; 10+ messages in thread
From: aleksi dot nurmi at helsinki dot fi @ 2008-11-17 14:08 UTC (permalink / raw)
To: gcc-bugs
------- Comment #3 from aleksi dot nurmi at helsinki dot fi 2008-11-17 14:06 -------
Works for me on 4.1.3 20080308 (prerelease) (Ubuntu 4.1.2-21ubuntu1) and
(Ubuntu 20081013-0ubuntu2) 4.3.3 20081014 (prerelease), too.
But not in 4.2.4 (Ubuntu 4.2.4-1ubuntu3).
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38167
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Bug c/38167] Accessor to stdin is breaks on -O2 optimization
2008-11-17 2:00 [Bug c/38167] New: Inline accessor to stdin is breaks on -O2 optimization aleksi dot nurmi at helsinki dot fi
` (2 preceding siblings ...)
2008-11-17 14:08 ` aleksi dot nurmi at helsinki dot fi
@ 2008-11-17 15:12 ` aleksi dot nurmi at helsinki dot fi
2008-11-17 15:55 ` [Bug c/38167] Accessor to stdin " aleksi dot nurmi at helsinki dot fi
` (4 subsequent siblings)
8 siblings, 0 replies; 10+ messages in thread
From: aleksi dot nurmi at helsinki dot fi @ 2008-11-17 15:12 UTC (permalink / raw)
To: gcc-bugs
------- Comment #4 from aleksi dot nurmi at helsinki dot fi 2008-11-17 15:11 -------
I found an even shorter way to make it segfault, with no inline functions at
all. It's an -O2 problem, then.
#include <stdio.h>
struct iostream {
FILE *f;
};
static struct iostream our_stdin = { 0 };
void read_char(struct iostream* ios)
{
if (ios->f == 0)
if (ios == &our_stdin)
ios->f = stdin;
fgetc(ios->f);
}
int main()
{
read_char(&our_stdin);
return 0;
}
--
aleksi dot nurmi at helsinki dot fi changed:
What |Removed |Added
----------------------------------------------------------------------------
Summary|Inline accessor to stdin is |Accessor to stdin is breaks
|breaks on -O2 optimization |on -O2 optimization
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38167
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Bug c/38167] Accessor to stdin breaks on -O2 optimization
2008-11-17 2:00 [Bug c/38167] New: Inline accessor to stdin is breaks on -O2 optimization aleksi dot nurmi at helsinki dot fi
` (3 preceding siblings ...)
2008-11-17 15:12 ` [Bug c/38167] Accessor " aleksi dot nurmi at helsinki dot fi
@ 2008-11-17 15:55 ` aleksi dot nurmi at helsinki dot fi
2008-11-24 17:48 ` [Bug middle-end/38167] " pinskia at gcc dot gnu dot org
` (3 subsequent siblings)
8 siblings, 0 replies; 10+ messages in thread
From: aleksi dot nurmi at helsinki dot fi @ 2008-11-17 15:55 UTC (permalink / raw)
To: gcc-bugs
------- Comment #5 from aleksi dot nurmi at helsinki dot fi 2008-11-17 15:53 -------
GDB output showing that libc (debug) received a null pointer:
Program received signal SIGSEGV, Segmentation fault.
_IO_getc (fp=0x0) at getc.c:40
40 _IO_acquire_lock (fp);
(gdb) print fp
$1 = (FILE *) 0x0
(gdb) up
#1 0x000000000040051e in main () at fault.c:20
20 read_char(&our_stdin);
(gdb) print our_stdin.f
$2 = (FILE *) 0x7f75cc0c96a0
(gdb) print stdin
$3 = (struct _IO_FILE *) 0x7f75cc0c96a0
--
aleksi dot nurmi at helsinki dot fi changed:
What |Removed |Added
----------------------------------------------------------------------------
Summary|Accessor to stdin is breaks |Accessor to stdin breaks on
|on -O2 optimization |-O2 optimization
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38167
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Bug middle-end/38167] Accessor to stdin breaks on -O2 optimization
2008-11-17 2:00 [Bug c/38167] New: Inline accessor to stdin is breaks on -O2 optimization aleksi dot nurmi at helsinki dot fi
` (4 preceding siblings ...)
2008-11-17 15:55 ` [Bug c/38167] Accessor to stdin " aleksi dot nurmi at helsinki dot fi
@ 2008-11-24 17:48 ` pinskia at gcc dot gnu dot org
2008-11-24 18:19 ` aleksi dot nurmi at helsinki dot fi
` (2 subsequent siblings)
8 siblings, 0 replies; 10+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2008-11-24 17:48 UTC (permalink / raw)
To: gcc-bugs
------- Comment #6 from pinskia at gcc dot gnu dot org 2008-11-24 17:46 -------
This is most likely one of the aliasing bugs. Does -fno-strict-aliasing fix
the issue?
--
pinskia at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Component|c |middle-end
Keywords| |wrong-code
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38167
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Bug middle-end/38167] Accessor to stdin breaks on -O2 optimization
2008-11-17 2:00 [Bug c/38167] New: Inline accessor to stdin is breaks on -O2 optimization aleksi dot nurmi at helsinki dot fi
` (5 preceding siblings ...)
2008-11-24 17:48 ` [Bug middle-end/38167] " pinskia at gcc dot gnu dot org
@ 2008-11-24 18:19 ` aleksi dot nurmi at helsinki dot fi
2008-11-24 19:34 ` [Bug middle-end/38167] [4.2 Regression] " pinskia at gcc dot gnu dot org
2009-03-31 15:51 ` jsm28 at gcc dot gnu dot org
8 siblings, 0 replies; 10+ messages in thread
From: aleksi dot nurmi at helsinki dot fi @ 2008-11-24 18:19 UTC (permalink / raw)
To: gcc-bugs
------- Comment #7 from aleksi dot nurmi at helsinki dot fi 2008-11-24 18:17 -------
(In reply to comment #6)
> This is most likely one of the aliasing bugs. Does -fno-strict-aliasing fix
> the issue?
Nope. I did a little research and it seems that -fno-tree-vrp fixes it.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38167
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Bug middle-end/38167] [4.2 Regression] Accessor to stdin breaks on -O2 optimization
2008-11-17 2:00 [Bug c/38167] New: Inline accessor to stdin is breaks on -O2 optimization aleksi dot nurmi at helsinki dot fi
` (6 preceding siblings ...)
2008-11-24 18:19 ` aleksi dot nurmi at helsinki dot fi
@ 2008-11-24 19:34 ` pinskia at gcc dot gnu dot org
2009-03-31 15:51 ` jsm28 at gcc dot gnu dot org
8 siblings, 0 replies; 10+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2008-11-24 19:34 UTC (permalink / raw)
To: gcc-bugs
--
pinskia at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Known to fail| |4.2.4
Known to work| |4.4.0 4.3.0
Summary|Accessor to stdin breaks on |[4.2 Regression] Accessor to
|-O2 optimization |stdin breaks on -O2
| |optimization
Target Milestone|--- |4.2.5
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38167
^ permalink raw reply [flat|nested] 10+ messages in thread
* [Bug middle-end/38167] [4.2 Regression] Accessor to stdin breaks on -O2 optimization
2008-11-17 2:00 [Bug c/38167] New: Inline accessor to stdin is breaks on -O2 optimization aleksi dot nurmi at helsinki dot fi
` (7 preceding siblings ...)
2008-11-24 19:34 ` [Bug middle-end/38167] [4.2 Regression] " pinskia at gcc dot gnu dot org
@ 2009-03-31 15:51 ` jsm28 at gcc dot gnu dot org
8 siblings, 0 replies; 10+ messages in thread
From: jsm28 at gcc dot gnu dot org @ 2009-03-31 15:51 UTC (permalink / raw)
To: gcc-bugs
------- Comment #8 from jsm28 at gcc dot gnu dot org 2009-03-31 15:50 -------
Closing 4.2 branch, fixed in 4.3.
--
jsm28 at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |RESOLVED
Known to fail|4.2.4 |4.2.4 4.2.5
Resolution| |FIXED
Target Milestone|4.2.5 |4.3.0
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38167
^ permalink raw reply [flat|nested] 10+ messages in thread