[Bug tree-optimization/49618] New: When building uClibc with GCC 4.6.1 old_atexit is miscompiled

[Bug tree-optimization/49618] New: When building uClibc with GCC 4.6.1 old_atexit is miscompiled

[sedat.dilek at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49618

           Summary: When building uClibc with GCC 4.6.1 old_atexit is
                    miscompiled
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: sedat.dilek@gmail.com


Created attachment 24661
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=24661
Preprocessed file "old_atexit.i"

Hi,

this issue kept me UP for several weeks. It first occured when generating a
mipsel target-toolchain based on gcc-4.6.0 with uClibc-0.9.32 for a router
project called freetz. Finally, I could track the problem with the assistance
from Edwin Török. A big thank you, Edwin.

### Problem description:

When building uClibc with GCC 4.6.1 old_atexit is miscompiled, which causes
this testprogram to crash when calling old_atexit:

#include <stdlib.h>
void foo() {}
int main() {     return atexit(foo);}

This is a regression from GCC 4.5.3 which compiled old_atexit() fine.

Attached is the preprocessed file old_atexit.i.

Commandline to create old_atexit.os:

mipsel-linux-uclibc-gcc -S old_atexit.i -o old_atexit.os -funsigned-char
-fno-builtin -fno-asm -msoft-float -std=gnu99 -march=4kc -mtune=4kc -mabi=32
-fno-stack-protector -Os -funit-at-a-time
-fmerge-all-constants -fstrict-aliasing -fno-tree-loop-optimize
-fno-tree-dominator-opts -fno-strength-reduce -mno-split-addresses -fPIC

As seen below with GCC 4.6.1 &__dso_handle is assumed to be non-NULL
and the branch (beqz) eliminated, but it is in fact NULL at runtime
which causes the crash.
With GCC 4.5.3 there is a beqz that tests for &__dso_handle == NULL:

000537d0 <old_atexit>:
  537d0:       3c1c0003        lui     gp,0x3
  537d4:       279c8d10        addiu   gp,gp,-29424
  537d8:       0399e021        addu    gp,gp,t9
  537dc:       8f828a2c        lw      v0,-30164(gp)
  537e0:       8f9989ac        lw      t9,-30292(gp)
  537e4:       8c460000        lw      a2,0(v0)
  ^^^^^^^^^^ SIGSEGV here, with a NULL dereference
  537e8:       00002821        move    a1,zero
  537ec:       03200008        jr      t9
  537f0:       0002300a        movz    a2,zero,v0

old_atexit.os with GCC 4.6.1:
       .file   1 "old_atexit.c"
       .section .mdebug.abi32
       .previous
       .gnu_attribute 4, 3
       .abicalls
       .text
       .align  2
       .globl  old_atexit
       .set    nomips16
       .ent    old_atexit
       .type   old_atexit, @function
old_atexit:
       .frame  $sp,0,$31               # vars= 0, regs= 0/0, args= 0, gp= 0
       .mask   0x00000000,0
       .fmask  0x00000000,0
       .set    noreorder
       .cpload $25
       .set    nomacro
       lw      $2,%got(__dso_handle)($28)
       lw      $25,%call16(__cxa_atexit)($28)
       lw      $6,0($2)
       move    $5,$0
       .reloc  1f,R_MIPS_JALR,__cxa_atexit
1:      jr      $25
       movz    $6,$0,$2

       .set    macro
       .set    reorder
       .end    old_atexit
       .size   old_atexit, .-old_atexit
       .weak   atexit
       atexit = old_atexit
       .weak   __dso_handle
       .ident  "GCC: (GNU) 4.6.1"

old_atexit.os with GCC 4.5.3:
       .file   1 "old_atexit.c"
       .section .mdebug.abi32
       .previous
       .gnu_attribute 4, 3
       .abicalls
       .text
       .align  2
       .globl  old_atexit
       .set    nomips16
       .ent    old_atexit
       .type   old_atexit, @function
old_atexit:
       .frame  $sp,0,$31               # vars= 0, regs= 0/0, args= 0, gp= 0
       .mask   0x00000000,0
       .fmask  0x00000000,0
       .set    noreorder
       .cpload $25
       .set    nomacro
       lw      $2,%got(__dso_handle)($28)
       beq     $2,$0,$L2
       move    $6,$0

       lw      $6,0($2)
$L2:
       lw      $25,%call16(__cxa_atexit)($28)
       .reloc  1f,R_MIPS_JALR,__cxa_atexit
1:      jr      $25
       move    $5,$0

       .set    macro
       .set    reorder
       .end    old_atexit
       .size   old_atexit, .-old_atexit
       .weak   atexit
       atexit = old_atexit
       .weak   __dso_handle
       .ident  "GCC: (GNU) 4.5.3"

### GCC versions (with gcc -v output) for target and host:

$
/mnt/sdb3/freetz/freetz-trunk_gcc-4.6.1/toolchain/build/mipsel_gcc-4.6.1_uClibc-0.9.32/mipsel-linux-uclibc/bin/mipsel-linux-uclibc-gcc
-v
Using built-in specs.
COLLECT_GCC=/mnt/sdb3/freetz/freetz-trunk_gcc-4.6.1/toolchain/build/mipsel_gcc-4.6.1_uClibc-0.9.32/mipsel-linux-uclibc/bin/mipsel-linux-uclibc-gcc
COLLECT_LTO_WRAPPER=/mnt/sdb3/freetz/freetz-trunk_gcc-4.6.1/toolchain/build/mipsel_gcc-4.6.1_uClibc-0.9.32/mipsel-linux-uclibc/bin/../libexec/gcc/mipsel-linux-uclibc/4.6.1/lto-wrapper
Target: mipsel-linux-uclibc
Configured with:
/mnt/sdb3/freetz/freetz-trunk/source/toolchain-mipsel_gcc-4.6.1_uClibc-0.9.32/gcc-4.6.1/configure
--prefix=/mnt/sdb3/freetz/freetz-trunk/toolchain/build/mipsel_gcc-4.6.1_uClibc-0.9.32/mipsel-linux-uclibc
--with-sysroot=/mnt/sdb3/freetz/freetz-trunk/toolchain/build/mipsel_gcc-4.6.1_uClibc-0.9.32/mipsel-linux-uclibc/usr/
--build=i386-pc-linux-gnu --host=i386-pc-linux-gnu --target=mipsel-linux-uclibc
--enable-languages=c,c++ --enable-shared --enable-threads
--with-gmp=/mnt/sdb3/freetz/freetz-trunk/tools/build
--with-mpfr=/mnt/sdb3/freetz/freetz-trunk/tools/build
--with-mpc=/mnt/sdb3/freetz/freetz-trunk/tools/build --with-gnu-ld
--disable-__cxa_atexit --disable-libgomp --disable-libmudflap
--disable-multilib --disable-tls --disable-fixed-point --with-float=soft
--enable-cxx-flags=-msoft-float --disable-libssp --with-march=4kc --disable-nls
--with-mips-plt --disable-decimal-float
Thread model: posix
gcc version 4.6.1 (GCC)

$
/mnt/sdb3/freetz/freetz-trunk_gcc-4.5.3/toolchain/build/mipsel_gcc-4.5.3_uClibc-0.9.32/mipsel-linux-uclibc/bin/mipsel-linux-uclibc-gcc
-v
Using built-in specs.
COLLECT_GCC=/mnt/sdb3/freetz/freetz-trunk_gcc-4.5.3/toolchain/build/mipsel_gcc-4.5.3_uClibc-0.9.32/mipsel-linux-uclibc/bin/mipsel-linux-uclibc-gcc
COLLECT_LTO_WRAPPER=/mnt/sdb3/freetz/freetz-trunk_gcc-4.5.3/toolchain/build/mipsel_gcc-4.5.3_uClibc-0.9.32/mipsel-linux-uclibc/bin/../libexec/gcc/mipsel-linux-uclibc/4.5.3/lto-wrapper
Target: mipsel-linux-uclibc
Configured with:
/mnt/sdb3/freetz/freetz-trunk/source/toolchain-mipsel_gcc-4.5.3_uClibc-0.9.32/gcc-4.5.3/configure
--prefix=/mnt/sdb3/freetz/freetz-trunk/toolchain/build/mipsel_gcc-4.5.3_uClibc-0.9.32/mipsel-linux-uclibc
--with-sysroot=/mnt/sdb3/freetz/freetz-trunk/toolchain/build/mipsel_gcc-4.5.3_uClibc-0.9.32/mipsel-linux-uclibc/usr/
--build=i386-pc-linux-gnu --host=i386-pc-linux-gnu --target=mipsel-linux-uclibc
--enable-languages=c,c++ --enable-shared --enable-threads
--with-gmp=/mnt/sdb3/freetz/freetz-trunk/tools/build
--with-mpfr=/mnt/sdb3/freetz/freetz-trunk/tools/build
--with-mpc=/mnt/sdb3/freetz/freetz-trunk/tools/build --with-gnu-ld
--disable-__cxa_atexit --disable-libgomp --disable-libmudflap
--disable-multilib --disable-tls --disable-fixed-point --with-float=soft
--enable-cxx-flags=-msoft-float --disable-libssp --with-march=4kc --disable-nls
--with-mips-plt --disable-decimal-float
Thread model: posix
gcc version 4.5.3 (GCC)

$ gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/i386-linux-gnu/gcc/i486-linux-gnu/4.6.1/lto-wrapper
Target: i486-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Debian 4.6.1-1'
--with-bugurl=file:///usr/share/doc/gcc-4.6/README.Bugs
--enable-languages=c,c++,fortran,objc,obj-c++,go --prefix=/usr
--program-suffix=-4.6 --enable-shared --enable-multiarch
--with-multiarch-defaults=i386-linux-gnu --enable-linker-build-id
--with-system-zlib --libexecdir=/usr/lib/i386-linux-gnu
--without-included-gettext --enable-threads=posix
--with-gxx-include-dir=/usr/include/c++/4.6 --libdir=/usr/lib/i386-linux-gnu
--enable-nls --enable-clocale=gnu --enable-libstdcxx-debug
--enable-libstdcxx-time=yes --enable-plugin --enable-objc-gc
--enable-targets=all --with-arch-32=i586 --with-tune=generic
--enable-checking=release --build=i486-linux-gnu --host=i486-linux-gnu
--target=i486-linux-gnu
Thread model: posix
gcc version 4.6.1 (Debian 4.6.1-1)

### Target is a Speedport W701V router:

# uname -a
Linux fritz.fonwlan.box 2.6.13.1-ohio #1 Thu Jun 30 17:59:33 CEST 2011 mips
GNU/Linux
# cat /proc/version 
Linux version 2.6.13.1-ohio () (gcc version 3.4.6) #1 Thu Jun 30 17:59:33 CEST
2011

### Host is a Debian/sid i386 system:

$ uname -a
Linux seduxbox 2.6.39-2-686-pae #1 SMP Wed Jun 8 11:33:14 UTC 2011 i686
GNU/Linux
$ cat /proc/version 
Linux version 2.6.39-2-686-pae (Debian 2.6.39-2) (ben@decadent.org.uk) (gcc
version 4.4.6 (Debian 4.4.6-3) ) #1 SMP Wed Jun 8 11:33:14 UTC 2011

Hope this helps to kill that BUG.

Kind Regards,
- Sedat -

[Bug tree-optimization/49618] When building uClibc with GCC 4.6.1 old_atexit is miscompiled

[tg at mirbsd dot org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49618

Thorsten Glaser <tg at mirbsd dot org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |tg at mirbsd dot org

--- Comment #1 from Thorsten Glaser <tg at mirbsd dot org> 2011-07-03 14:58:47 UTC ---
Ouch. I can see where it might be NULL… but in anal-C99 taking a pointer of
an object (&__dso_handle) can never be a NULL pointer, so GCC might, in a
very theoretical sense, be correct in optimising away this check.

Does adding -fno-delete-null-pointer-checks to the compile options help?

[Bug tree-optimization/49618] When building uClibc with GCC 4.6.1 old_atexit is miscompiled

[edwintorok at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49618

--- Comment #2 from Török Edwin <edwintorok at gmail dot com> 2011-07-03 15:07:02 UTC ---
(In reply to comment #1)
> Ouch. I can see where it might be NULL… but in anal-C99 taking a pointer of
> an object (&__dso_handle) can never be a NULL pointer, so GCC might, in a
> very theoretical sense, be correct in optimising away this check.
> 
> Does adding -fno-delete-null-pointer-checks to the compile options help?

No, with -fno-delete-null-pointer-checks the 'beq' instruction is still
deleted.

-O1 works though.

[Bug tree-optimization/49618] When building uClibc with GCC 4.6.1 old_atexit is miscompiled

[sedat.dilek at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49618

--- Comment #3 from dileks <sedat.dilek at gmail dot com> 2011-07-03 15:39:02 UTC ---
Short feedback: -O{0,1,2,} works (beq* is there), -Os doesn't (beq deleted).

[ -O0 ]
    beq    $2,$0,$L2

[ -O1 ]
    beql    $2,$0,$L3

[ -O2 ]
    beql    $2,$0,$L2

[ -Os ]
[ empty ]

[Bug tree-optimization/49618] When building uClibc with GCC 4.6.1 old_atexit is miscompiled

[sedat.dilek at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49618

--- Comment #4 from Sedat Dilek <sedat.dilek at gmail dot com> 2011-07-03 17:46:07 UTC ---
With the Patch from [1] I could boot a firmware-image on my router.

[1]
http://freetz.org/attachment/ticket/1310/gcc-4.6.x-disable-if-conversion.patch

[Bug tree-optimization/49618] When building uClibc with GCC 4.6.1 old_atexit is miscompiled

[pinskia at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49618

--- Comment #5 from Andrew Pinski <pinskia at gcc dot gnu.org> 2011-07-03 19:27:08 UTC ---
__dso_handle should be marked as weak in the source.

[Bug tree-optimization/49618] When building uClibc with GCC 4.6.1 old_atexit is miscompiled

[pinskia at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49618

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |wrong-code
   Target Milestone|---                         |4.6.2

--- Comment #6 from Andrew Pinski <pinskia at gcc dot gnu.org> 2011-07-03 19:28:08 UTC ---
Hmm, it is already marked as weak.

[Bug tree-optimization/49618] When building uClibc with GCC 4.6.1 old_atexit is miscompiled

[ernews at gmx dot de]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49618

Eugene Rudoy <ernews at gmx dot de> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |ernews at gmx dot de

--- Comment #7 from Eugene Rudoy <ernews at gmx dot de> 2011-07-03 20:09:42 UTC ---
(In reply to comment #4)
> With the Patch from [1] I could boot a firmware-image on my router.
It seems the "if-conversion"-opt is not the actual reason. It does solve the
issue, but it's not the reason. Explanation: "if-conversion" is enabled by
default at -O1. The code is however not miss-compiled when compiled using -O1
(-Os causes it to be miss-compiled).

I found out that disabling gcse and cse-follow-jumps (i.e. passing -fno-gcse
-fno-cse-follow-jumps [1]) also solves the issue. As the optimization level
(-O2/-Os) these both are by default enabled on correspond to the -Os flag we
use I consider them to be the actual reason for the miss-compiling.

[1] http://freetz.org/attachment/ticket/1310/gcc-4.6.x-disable-opt-flags.patch

[Bug tree-optimization/49618] When building uClibc with GCC 4.6.1 old_atexit is miscompiled

[sedat.dilek at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49618

--- Comment #8 from Sedat Dilek <sedat.dilek at gmail dot com> 2011-07-03 20:47:37 UTC ---
Confirmed... Image built with gcc-4.6.x-disable-opt-flags.patch works also
fine.

[Bug tree-optimization/49618] When building uClibc with GCC 4.6.1 old_atexit is miscompiled

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49618

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |ebotcazou at gcc dot
                   |                            |gnu.org, jakub at gcc dot
                   |                            |gnu.org, rsandifo at gcc
                   |                            |dot gnu.org

--- Comment #9 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-07-04 08:10:19 UTC ---
I think the problem is either that the MEM has the MEM_NOTRAP_P flag set on it:
(mem/f/i:SI (symbol_ref/i:SI ("__dso_handle") <var_decl 0x7ffff13ce320
__dso_handle>) [0 S4 A32])
That makes ifcvt believe it can try to use a conditional move with that as an
operand, and as there is no conditional move with MEM operand on this target,
it is forced into register first.

MEM_NOTRAP_P is set in set_mem_attributes_minus_bitpos:
  /* Note whether this expression can trap.  */
  MEM_NOTRAP_P (ref) = !tree_could_trap_p (t);
where t is VAR_DECL for __dso_handle with DECL_WEAK.

Or the problem might be that noce_try_cmove_arith should be using
  else if (may_trap_or_fault_p (a) || may_trap_or_fault_p (b))
    return FALSE;
instead of
  else if (may_trap_p (a) || may_trap_p (b))
    return FALSE;

Eric/Richard, what do you think?  The comments seem to be fuzzy to me, some
comments say that MEM_NOTRAP_P only apply to the position where the MEM is
originally used (and in this case the __dso_handle var is read only guarded
with if (__dso_handle != NULL), on the other side I wonder if we ever clear
MEM_NOTRAP_P on unguarded DECL_WEAK var references.

[Bug tree-optimization/49618] When building uClibc with GCC 4.6.1 old_atexit is miscompiled

[ebotcazou at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49618

--- Comment #10 from Eric Botcazou <ebotcazou at gcc dot gnu.org> 2011-07-04 10:14:40 UTC ---
> Eric/Richard, what do you think?  The comments seem to be fuzzy to me, some
> comments say that MEM_NOTRAP_P only apply to the position where the MEM is
> originally used (and in this case the __dso_handle var is read only guarded
> with if (__dso_handle != NULL), on the other side I wonder if we ever clear
> MEM_NOTRAP_P on unguarded DECL_WEAK var references.

I think that DECL_WEAK should always prevent MEM_NOTRAP_P from being set.  This
is a regression because of the change in set_mem_attributes_minus_bitpos,
right?

The code on the 4.5 branch reads:

      if (DECL_P (base))
    {
      if (CODE_CONTAINS_STRUCT (TREE_CODE (base), TS_DECL_WITH_VIS))
        MEM_NOTRAP_P (ref) = !DECL_WEAK (base);
      else
        MEM_NOTRAP_P (ref) = 1;
    }
      else
    MEM_NOTRAP_P (ref) = TREE_THIS_NOTRAP (base);

Maybe the first part should be reinstated.

[Bug tree-optimization/49618] When building uClibc with GCC 4.6.1 old_atexit is miscompiled

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49618

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2011.07.04 12:38:03
         AssignedTo|unassigned at gcc dot       |jakub at gcc dot gnu.org
                   |gnu.org                     |
     Ever Confirmed|0                           |1

--- Comment #11 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-07-04 12:38:03 UTC ---
Created attachment 24673
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=24673
gcc47-pr49618.patch

Untested 4.7 fix.

[Bug tree-optimization/49618] When building uClibc with GCC 4.6.1 old_atexit is miscompiled

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49618

--- Comment #12 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-07-04 12:39:21 UTC ---
Created attachment 24674
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=24674
gcc46-pr49618.patch

Untested more conservative 4.6 fix.

[Bug tree-optimization/49618] When building uClibc with GCC 4.6.1 old_atexit is miscompiled

[sedat.dilek at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49618

--- Comment #13 from Sedat Dilek <sedat.dilek at gmail dot com> 2011-07-04 14:29:27 UTC ---
Confirmed... gcc46-pr49618.patch solves the problem here, workaround patches
from freetz project are no more necessary.

[Bug tree-optimization/49618] When building uClibc with GCC 4.6.1 old_atexit is miscompiled

[sedat.dilek at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49618

--- Comment #14 from Sedat Dilek <sedat.dilek at gmail dot com> 2011-07-04 14:38:05 UTC ---
Thank you gcc folks and all involved people to fix this bug.

[Bug tree-optimization/49618] When building uClibc with GCC 4.6.1 old_atexit is miscompiled

[sedat.dilek at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49618

--- Comment #15 from Sedat Dilek <sedat.dilek at gmail dot com> 2011-07-04 16:47:25 UTC ---
Created attachment 24677
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=24677
Simple testcase-script for gcc-PR49618

[Bug tree-optimization/49618] When building uClibc with GCC 4.6.1 old_atexit is miscompiled

[sedat.dilek at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49618

--- Comment #17 from Sedat Dilek <sedat.dilek at gmail dot com> 2011-07-04 16:48:44 UTC ---
Created attachment 24679
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=24679
old_atexit.os_OptLevel-O1

[Bug tree-optimization/49618] When building uClibc with GCC 4.6.1 old_atexit is miscompiled

[sedat.dilek at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49618

--- Comment #20 from Sedat Dilek <sedat.dilek at gmail dot com> 2011-07-04 16:50:10 UTC ---
Created attachment 24682
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=24682
old_atexit.os_OptLevel-Os

[Bug tree-optimization/49618] When building uClibc with GCC 4.6.1 old_atexit is miscompiled

[sedat.dilek at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49618

--- Comment #19 from Sedat Dilek <sedat.dilek at gmail dot com> 2011-07-04 16:49:44 UTC ---
Created attachment 24681
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=24681
old_atexit.os_OptLevel-O3

[Bug tree-optimization/49618] When building uClibc with GCC 4.6.1 old_atexit is miscompiled

[sedat.dilek at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49618

--- Comment #18 from Sedat Dilek <sedat.dilek at gmail dot com> 2011-07-04 16:49:13 UTC ---
Created attachment 24680
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=24680
old_atexit.os_OptLevel-O2

[Bug tree-optimization/49618] When building uClibc with GCC 4.6.1 old_atexit is miscompiled

[sedat.dilek at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49618

--- Comment #16 from Sedat Dilek <sedat.dilek at gmail dot com> 2011-07-04 16:48:15 UTC ---
Created attachment 24678
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=24678
old_atexit.os_OptLevel-O0

[Bug tree-optimization/49618] When building uClibc with GCC 4.6.1 old_atexit is miscompiled

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49618

--- Comment #21 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-07-05 18:43:07 UTC ---
Author: jakub
Date: Tue Jul  5 18:43:04 2011
New Revision: 175884

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=175884
Log:
    PR tree-optimization/49618
    * tree-eh.c (tree_could_trap_p) <case CALL_EXPR>: For DECL_WEAK
    t recurse on the decl.
    <case FUNCTION_DECL, case VAR_DECL>: For DECL_WEAK decls
    return true if expr isn't known to be defined in current
    TU or some other LTO partition.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/tree-eh.c

[Bug tree-optimization/49618] When building uClibc with GCC 4.6.1 old_atexit is miscompiled

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49618

--- Comment #22 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-07-05 18:44:35 UTC ---
Author: jakub
Date: Tue Jul  5 18:44:32 2011
New Revision: 175885

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=175885
Log:
    PR tree-optimization/49618
    * tree-eh.c (tree_could_trap_p) <case FUNCTION_DECL, case VAR_DECL>:
    For DECL_WEAK decls return true.

Modified:
    branches/gcc-4_6-branch/gcc/ChangeLog
    branches/gcc-4_6-branch/gcc/tree-eh.c

[Bug tree-optimization/49618] When building uClibc with GCC 4.6.1 old_atexit is miscompiled

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49618

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|                            |FIXED

--- Comment #23 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-07-05 19:12:01 UTC ---
Should be fixed now.