/usr/lib/gcc/x86_64-linux-gnu/4.5/lto1 crashes with segmentation fault when both -fopenmp and -flto are used

Minimal test case on which the bug can be reproduced

Preprocessed version of test.c

Backtrace.

Obtained by using

gcc-4.5 test.c -o test -Os -fopenmp -flto -std=c99 -save-temps -v

and then

gdb /usr/lib/gcc/x86_64-linux-gnu/4.5.1/lto1

with the arguments displayed by gcc -v

If necessary, can attach

/tmp/cc5yp0gX.lto.o
/tmp/ccvA4NFX
test.s

as well

apport information

Same happens with -fwhopr instead of -flto

please could you recheck this with gcc-4.6 (in an oneiric chroot)

With gcc-4.6 I see a different bug.

When compiling without -flto, ie

gcc test.c -o test -O1 -fopenmp -std=c99

everything is fine.

With -flto:

$ gcc test.c -o test -O1 -fopenmp -flto -std=c99
/tmp/cckxIhdE.ltrans0.ltrans.o: In function `main._omp_fn.0.2060.2020':
cckxIhdE.ltrans0.o:(.text+0x2): undefined reference to `omp_get_num_threads'
cckxIhdE.ltrans0.o:(.text+0x9): undefined reference to `omp_get_thread_num'
/tmp/cckxIhdE.ltrans0.ltrans.o: In function `main':
cckxIhdE.ltrans0.o:(.text+0x87): undefined reference to `GOMP_parallel_start'
cckxIhdE.ltrans0.o:(.text+0x8c): undefined reference to `GOMP_parallel_end'
collect2: ld returned 1 exit status

$ gcc test.c -o test -O1 -fopenmp -flto -std=c99 -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/x86_64-linux-gnu/gcc/x86_64-linux-gnu/4.6.1/lto-wrapper
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu/Linaro 4.6.1-4ubuntu1' --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=x86_64-linux-gnu --enable-linker-build-id --with-system-zlib --libexecdir=/usr/lib/x86_64-linux-gnu --without-included-gettext --enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.6 --libdir=/usr/lib/x86_64-linux-gnu --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --enable-plugin --enable-objc-gc --disable-werror --with-arch-32=i686 --with-tune=generic --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix
gcc version 4.6.1 (Ubuntu/Linaro 4.6.1-4ubuntu1)
COLLECT_GCC_OPTIONS='-o' 'test' '-O1' '-fopenmp' '-flto' '-std=c99' '-v' '-mtune=generic' '-march=x86-64' '-pthread'
 /usr/lib/x86_64-linux-gnu/gcc/x86_64-linux-gnu/4.6.1/cc1 -quiet -v -D_REENTRANT test.c -quiet -dumpbase test.c -mtune=generic -march=x86-64 -auxbase test -O1 -std=c99 -version -fopenmp -flto -fstack-protector -o /tmp/ccjn2A1G.s
GNU C (Ubuntu/Linaro 4.6.1-4ubuntu1) version 4.6.1 (x86_64-linux-gnu)
        compiled by GNU C version 4.6.1, GMP version 5.0.1, MPFR version 3.0.1-p3, MPC version 0.9
GGC heuristics: --param ggc-min-expand=30 --param ggc-min-heapsize=4096
ignoring nonexistent directory "/usr/local/include/x86_64-linux-gnu"
ignoring nonexistent directory "/usr/lib/x86_64-linux-gnu/gcc/x86_64-linux-gnu/4.6.1/../../../../../x86_64-linux-gnu/include"
#include "..." search starts here:
#include <...> search starts here:
 /usr/lib/x86_64-linux-gnu/gcc/x86_64-linux-gnu/4.6.1/include
 /usr/local/include
 /usr/lib/x86_64-linux-gnu/gcc/x86_64-linux-gnu/4.6.1/include-fixed
 /usr/include/x86_64-linux-gnu
 /usr/include
End of search list.
GNU C (Ubuntu/Linaro 4.6.1-4ubuntu1) version 4.6.1 (x86_64-linux-gnu)
        compiled by GNU C version 4.6.1, GMP version 5.0.1, MPFR version 3.0.1-p3, MPC version 0.9
GGC heuristics: --param ggc-min-expand=30 --param ggc-min-heapsize=4096
Compiler executable checksum: f4dac7f0dc853914603e09c85c5ce51e
COLLECT_GCC_OPTIONS='-o' 'test' '-O1' '-fopenmp' '-flto' '-std=c99' '-v' '-mtune=ge...

This bug was fixed in the package binutils - 2.21.53.20110810-0ubuntu3

---------------
binutils (2.21.53.20110810-0ubuntu3) oneiric; urgency=low

  * Fix PR ld/13201, link error with --as-needed and -flto. LP: #778292.
    LP: #690194.
 -- Matthias Klose <email address hidden> Tue, 20 Sep 2011 11:34:33 +0200