http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56983
Bug #: 56983
Summary: Label in asm deleted after call to non-returning
function
Classification: Unclassified
Product: gcc
Version: 4.7.2
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
AssignedTo: unassig...@gcc.gnu.org
ReportedBy: silvioricar...@gmail.com
gcc -v:
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/i686-linux-gnu/4.7/lto-wrapper
Target: i686-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu/Linaro
4.7.2-2ubuntu1' --with-bugurl=file:///usr/share/doc/gcc-4.7/README.Bugs
--enable-languages=c,c++,go,fortran,objc,obj-c++ --prefix=/usr
--program-suffix=-4.7 --enable-shared --enable-linker-build-id
--with-system-zlib --libexecdir=/usr/lib --without-included-gettext
--enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.7
--libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu
--enable-libstdcxx-debug --enable-libstdcxx-time=yes --enable-gnu-unique-object
--enable-plugin --enable-objc-gc --enable-targets=all --disable-werror
--with-arch-32=i686 --with-tune=generic --enable-checking=release
--build=i686-linux-gnu --host=i686-linux-gnu --target=i686-linux-gnu
Thread model: posix
gcc version 4.7.2 (Ubuntu/Linaro 4.7.2-2ubuntu1)
uname -a:
Linux silvioricardoc-laptop 3.5.0-27-generic #46-Ubuntu SMP Mon Mar 25 20:00:05
UTC 2013 i686 i686 i686 GNU/Linux
Command-line:
gcc -Wall -Wextra code.c
Description:
GCC eliminates all code following a call to a non-returning function, even if
this code includes an asm label that can be jumped to. In the latter case, it
will generate the "jump-to-label" assembly output, but the code will fail to
link due to the missing label.
The problem may be the fact that GCC does not know when an asm label can be
jumped into, but in this case, the correct solution should be to act
conservatively and keep that part of the code intact.