C++ link failure on ARM

[Jani Monoses]

Binary package hint: gcc-4.5

The package luatex FTBFS on armel

./CXXLD.sh: g++ -Wall -Wunused -Wimplicit -Wreturn-type -Wno-unknown-pragmas -Wshadow -g -O2 -Wl,-Bsymbolic-functions -o luatex luatex-luatex.o -Wl,--export-dynamic libluatex.a libff.a libluamisc.a libluasocket.a liblua51.a /home/jani/ftbfs/luate/luatex-0.60.2/build/libs/zziplib/libzzip.a -lpng -lz -lpoppler /home/jani/ftbfs/luate/luatex-0.60.2/build/libs/obsdcompat/libopenbsd-compat.a libmd5.a libmplib.a lib/lib.a /home/jani/ftbfs/luate/luatex-0.60.2/build/texk/kpathsea/.libs/libkpathsea.a -ldl -lm -nodefaultlibs -Wl,-Bstatic -lstdc++ -Wl,-Bdynamic -lm -lgcc_eh -lgcc -lc -lgcc_eh -lgcc
/usr/bin/ld: /usr/lib/gcc/arm-linux-gnueabi/4.5.2/libgcc_eh.a(unwind-arm.o): undefined reference to symbol '__exidx_end'
/usr/bin/ld: note: '__exidx_end' is defined in DSO /usr/lib/liblcms.so.1 so try adding it to the linker command line
/usr/lib/liblcms.so.1: could not read symbols: Invalid operation

If I rerun the same command line with g++-4.4 it links.

Complete build log
http://launchpadlibrarian.net/58040388/buildlog_ubuntu-natty-armel.luatex_0.60.2-1_FAILEDTOBUILD.txt.gz

[Matthias Klose (doko)]

maybe not Linaro related, but please could you have look at it?

[Michael Hope (michaelh1)]

Compiling luatex_0.60.1-1build2 under Maverick with gcc-linaro-4.5-2010.11-1 succeeds:

libtool: link: ./CXXLD.sh -Wall -Wunused -Wimplicit -Wreturn-type -Wno-unknown-pragmas -Wshadow -g -O2 -Wl,-Bsymbolic-functions -o luatex luatex-luatex.o -Wl,--export-dynamic libluatex.a libff.a libluamisc.a libluasocket.a liblua51.a /home/michaelh/linaro/packages/luatex-0.60.1/build/libs/zziplib/libzzip.a -lpng -lz -lpoppler /home/michaelh/linaro/packages/luatex-0.60.1/build/libs/obsdcompat/libopenbsd-compat.a libmd5.a libmplib.a lib/lib.a /home/michaelh/linaro/packages/luatex-0.60.1/build/texk/kpathsea/.libs/libkpathsea.a -ldl -lm
./CXXLD.sh: g++-linaro -Wall -Wunused -Wimplicit -Wreturn-type -Wno-unknown-pragmas -Wshadow -g -O2 -Wl,-Bsymbolic-functions -o luatex luatex-luatex.o -Wl,--export-dynamic libluatex.a libff.a libluamisc.a libluasocket.a liblua51.a /home/michaelh/linaro/packages/luatex-0.60.1/build/libs/zziplib/libzzip.a -lpng -lz -lpoppler /home/michaelh/linaro/packages/luatex-0.60.1/build/libs/obsdcompat/libopenbsd-compat.a libmd5.a libmplib.a lib/lib.a /home/michaelh/linaro/packages/luatex-0.60.1/build/texk/kpathsea/.libs/libkpathsea.a -ldl -lm -nodefaultlibs -Wl,-Bstatic -lstdc++ -Wl,-Bdynamic -lm -lgcc_eh -lgcc -lc -lgcc_eh -lgcc
make[6]: Leaving directory `/home/michaelh/linaro/packages/luatex-0.60.1/build/texk/web2c'

The 'libgcc_eh.a' reference is interesting. The command line includes a '-Bstatic libstdc++' followed by a '-Bdynamic -lm -lgcc_eh' etc. I wonder why libgcc_eh.a is being referenced instead of libgcc_eh.so

[Michael Hope (michaelh1)]

Compiling luatex_0.60.2-1 under Natty with gcc-linaro-4.5.2010.11-1 succeeds.

[Jani Monoses (jani)]

This is the version of the failing gcc
g++ (Ubuntu/Linaro 4.5.1-10ubuntu3)
FWIW I see no libgcc_eh.so installed on the system (neither on ARM nor x86 natty) only the static lib.

[Andrew Stubbs (ams-codesourcery)]

I can reproduce the failure under a Natty chroot.

The missing symbol, "__exidx_end", is defined by the linker script (see /usr/lib/ldscripts/armelf_linux_eabi.x), so I can't see why it isn't defined, but that's just a symptom of the real problem.

For whatever reason, this package is setup to link libstdc++ statically, not dynamically, and this means manually specifying all the hidden libraries, but they have been done incorrectly. If the command is truncated before the "-nodefaultlibs" option, thus allowing the compile driver to do a normal link, it does not use libgcc_eh at all, but uses libgcc_s.so instead, and the link is successful.

The following link line works correctly with this compiler:

g++ -Wall -Wunused -Wimplicit -Wreturn-type -Wno-unknown-pragmas -Wshadow -g -O2 -Wl,-Bsymbolic-functions -o luatex luatex-luatex.o -Wl,--export-dynamic libluatex.a libff.a libluamisc.a libluasocket.a liblua51.a /home/ams/lp686381/luatex-0.60.2/build/libs/zziplib/libzzip.a -lpng -lz -lpoppler /home/ams/lp686381/luatex-0.60.2/build/libs/obsdcompat/libopenbsd-compat.a libmd5.a libmplib.a lib/lib.a /home/ams/lp686381/luatex-0.60.2/build/texk/kpathsea/.libs/libkpathsea.a -ldl -lm -nodefaultlibs -Wl,-Bstatic -lstdc++ -Wl,-Bdynamic -lm -lgcc_s -lgcc -lc -lgcc_s -lgcc

[Jani Monoses (jani)]

so is this a packaging bug? In that case it should be reassigned to luatex.

[Jani Monoses (jani)]

This is the automake macro that creates the explicit library order and call to the linker, it is used by various latex-related packages apparently

http://www.tex.ac.uk/tex-archive/systems/luatex/source/m4/kpse-cxx-hack.m4