[Bug c++/55468] New: Label value to incorrect destination

[Bug c++/55468] New: Label value to incorrect destination

[martin.girard5 at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55468

             Bug #: 55468
           Summary: Label value to incorrect destination
    Classification: Unclassified
           Product: gcc
           Version: 4.7.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: martin.girard5@gmail.com


This is a case of a label pointing to the wrong line. It is clear from looking
at the disassembly that the value of said label is bogus.

Look around line 31452. The sigtrap label points to line 31458. Instead, the
&&sigtrap label gives the address of line 31448, four lines above instead of
six lines below.

In the disassembly, one can see a movl instruction writing the address as a
function argument onto the stack, and said address is unmistakably the WSTOPSIG
macro four lines prior. As a result, the executable loops indefinitely upon
reaching this area, whereas it should be skipping the next block instead.

[Bug c++/55468] Label value to incorrect destination

[martin.girard5 at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55468

--- Comment #1 from martin.girard5 at gmail dot com 2012-11-26 06:29:52 UTC ---
Created attachment 28777
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=28777
The preprocessed output

[Bug c++/55468] Label value to incorrect destination

[martin.girard5 at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55468

--- Comment #2 from martin.girard5 at gmail dot com 2012-11-26 06:39:35 UTC ---
COLLECT_GCC=g++
COLLECT_LTO_WRAPPER=/usr/lib64/gcc/x86_64-suse-linux/4.7/lto-wrapper
Target: x86_64-suse-linux
Configured with: ../configure --prefix=/usr --infodir=/usr/share/info
--mandir=/usr/share/man --libdir=/usr/lib64 --libexecdir=/usr/lib64
--enable-languages=c,c++,objc,fortran,obj-c++,java,ada
--enable-checking=release --with-gxx-include-dir=/usr/include/c++/4.7
--enable-ssp --disable-libssp --disable-libitm --disable-plugin
--with-bugurl=http://bugs.opensuse.org/ --with-pkgversion='SUSE Linux'
--disable-libgcj --disable-libmudflap --with-slibdir=/lib64 --with-system-zlib
--enable-__cxa_atexit --enable-libstdcxx-allocator=new --disable-libstdcxx-pch
--enable-version-specific-runtime-libs --enable-linker-build-id
--program-suffix=-4.7 --enable-linux-futex --without-system-libunwind
--with-arch-32=i586 --with-tune=generic --build=x86_64-suse-linux
Thread model: posix
gcc version 4.7.2 20120920 [gcc-4_7-branch revision 191568] (SUSE Linux) 
COLLECT_GCC_OPTIONS='-o' 'test' '-v' '-save-temps' '-std=c++11' '-I'
'../include' '-march=pentium4' '-mtune=native' '-mfpmath=sse' '-m32'
'-static-libgcc' '-Wno-invalid-offsetof' '-Wno-overflow' '-Wno-pointer-arith'
'-Wno-unused-function' '-Wno-attributes' '-fno-threadsafe-statics'

[Bug c++/55468] Label value to incorrect destination

[pinskia at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55468

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|                            |INVALID

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> 2012-11-26 08:56:22 UTC ---
Labels as values are only designed and will only work with computed gotos.  Any
other use is an undefined use of them.

The actual labels are moved around just like any other label would be and will
be place at random places in the code if not used with computed gotos.

[Bug c++/55468] Label value to incorrect destination

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=55468

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|INVALID                     |DUPLICATE

--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Dup.

*** This bug has been marked as a duplicate of bug 44298 ***