[Bug lto/59183] New: configure of pdsh successfuly checks for function shl_load when lto is enabled

[steffen at hauihau dot de]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59183

            Bug ID: 59183
           Summary: configure of pdsh successfuly checks for function
                    shl_load when lto is enabled
           Product: gcc
           Version: 4.8.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: lto
          Assignee: unassigned at gcc dot gnu.org
          Reporter: steffen at hauihau dot de

Created attachment 31243
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=31243&action=edit
Output directories with -save-temps of both gcc runs with disabled and enabled
lto

Hi all,

I was running into an issue when I tried to compile pdsh 2.26 (a parallel
shell, see https://computing.llnl.gov/linux/pdsh.html). When lto is enabled,
configure successfully checks for function shl_load, but fails when lto is
disabled.

With enabled lto:
gcc -o shl_load_test -march=native -O2 -pipe -ggdb -floop-interchange
-floop-strip-mine -floop-block -ftree-loop-distribution -fira-loop-pressure
-ftree-vectorize -ftree-loop-linear -flto=5 -fuse-linker-plugin -Wl,-O1
-Wl,--as-needed -march=native -O2 -pipe -ggdb -floop-interchange
-floop-strip-mine -floop-block -ftree-loop-distribution -fira-loop-pressure
-ftree-vectorize -ftree-loop-linear -flto=5 -fuse-linker-plugin -Wl,-znow
-Wl,--sort-common -Wl,--hash-style=gnu -Wl,--enable-new-dtags -save-temps
shl_load_test.c 
gcc: warning: -pipe ignored because -save-temps specified
gcc: warning: -pipe ignored because -save-temps specified
[Leaving LTRANS /tmp/ccSSsJJ4.args]
[Leaving LTRANS shl_load_test.ltrans.out]
gcc: warning: -pipe ignored because -save-temps specified
[Leaving LTRANS /tmp/cc259S6e.mk]
[Leaving LTRANS shl_load_test.ltrans0.o]


With disabled lto:
gcc -o shl_load_test -march=native -O2 -pipe -ggdb -floop-interchange
-floop-strip-mine -floop-block -ftree-loop-distribution -fira-loop-pressure
-ftree-vectorize -ftree-loop-linear -Wl,-O1 -Wl,--as-needed -march=native -O2
-pipe -ggdb -floop-interchange -floop-strip-mine -floop-block
-ftree-loop-distribution -fira-loop-pressure -ftree-vectorize
-ftree-loop-linear -Wl,-znow -Wl,--sort-common -Wl,--hash-style=gnu
-Wl,--enable-new-dtags -save-temps shl_load_test.c gcc: warning: -pipe ignored
because -save-temps specified
shl_load_test.o:shl_load_test.c:function f: error: undefined reference to
'shl_load'
shl_load_test.c:69: error: undefined reference to 'shl_load'
collect2: error: ld returned 1 exit status


The latter one is the desired result, as this function is not present on my
system.

I have this issue also with another package (libsidplay) where configure checks
successfully for strnicmp and stricmp, which are both not present. Disabled lto
here does also prevent configure from successfully checking for these two
functions. I've compared the piece of code, which configure uses to check for
these functions and it is identical to the code that the configure from pdsh
uses to check for shl_load (replace shl_load with strnicmp/stricmp).


Here is the output of gcc -v:
COLLECT_GCC=/usr/x86_64-pc-linux-gnu/gcc-bin/4.8.2/gcc
COLLECT_LTO_WRAPPER=/usr/libexec/gcc/x86_64-pc-linux-gnu/4.8.2/lto-wrapper
Ziel: x86_64-pc-linux-gnu
Konfiguriert mit:
/home/misc/gentoo/tmp/portage/sys-devel/gcc-4.8.2/work/gcc-4.8.2/configure
--prefix=/usr --bindir=/usr/x86_64-pc-linux-gnu/gcc-bin/4.8.2
--includedir=/usr/lib/gcc/x86_64-pc-linux-gnu/4.8.2/include
--datadir=/usr/share/gcc-data/x86_64-pc-linux-gnu/4.8.2
--mandir=/usr/share/gcc-data/x86_64-pc-linux-gnu/4.8.2/man
--infodir=/usr/share/gcc-data/x86_64-pc-linux-gnu/4.8.2/info
--with-gxx-include-dir=/usr/lib/gcc/x86_64-pc-linux-gnu/4.8.2/include/g++-v4
--host=x86_64-pc-linux-gnu --build=x86_64-pc-linux-gnu --disable-altivec
--disable-fixed-point --with-cloog --disable-isl-version-check --enable-lto
--enable-nls --without-included-gettext --with-system-zlib --enable-obsolete
--disable-werror --enable-secureplt --enable-multilib
--with-multilib-list=m32,m64 --enable-libmudflap --disable-libssp
--enable-libgomp
--with-python-dir=/share/gcc-data/x86_64-pc-linux-gnu/4.8.2/python
--enable-checking=release --disable-libgcj --enable-libstdcxx-time
--enable-languages=c,c++,fortran --enable-shared --enable-threads=posix
--enable-__cxa_atexit --enable-clocale=gnu --enable-targets=all
--with-bugurl=http://bugs.gentoo.org/ --with-pkgversion='Gentoo 4.8.2 p1.0,
pie-0.5.8'
Thread-Modell: posix
gcc-Version 4.8.2 (Gentoo 4.8.2 p1.0, pie-0.5.8) 


Please let me know wether you need more input/files from me.