Linking GraphicsMagick++ with clang libc++ on Linux

Question

I'm trying to compile an app on Ubuntu 12.04 x64. It was built on osx with clang 3.2, uses the new c++11 standard and has dependencies to boost and GraphicsMagick++ and running fine. Compiling with gcc 4.8.1 yielded a compiler crash. Unfortunately we have to release the software asap and can't wait for gcc to fix the bugs.

After some trial and error with clang on linux and reading through some mailing lists I managed according to this post https://plus.google.com/u/0/+DeWittClinton/posts/Vr7y8TPsKgR to compile it with clang 3.3 and libc++ (and libc++abi). All unit tests relating to boost (header only and shared object libs) are executing well. After we start to link against GraphicsMagick++ it results in undefined reference errors below.

"/usr/bin/ld" -export-dynamic -z relro --hash-style=gnu --build-id --eh-frame-hdr -m elf_x86_64 -dynamic-linker /lib64/ld-linux-x86-64.so.2 -o ../test_xxx_import /usr/lib/gcc/x86_64-linux-gnu/4.8/../../../x86_64-linux-gnu/crt1.o /usr/lib/gcc/x86_64-linux-gnu/4.8/../../../x86_64-linux-gnu/crti.o /usr/lib/gcc/x86_64-linux-gnu/4.8/crtbegin.o -L/usr/local/lib/ -L/usr/lib/gcc/x86_64-linux-gnu/4.8 -L/usr/lib/gcc/x86_64-linux-gnu/4.8/../../../x86_64-linux-gnu -L/lib/x86_64-linux-gnu -L/lib/../lib64 -L/usr/lib/x86_64-linux-gnu -L/usr/lib/gcc/x86_64-linux-gnu/4.8/../../.. -L/lib -L/usr/lib -lc++ -lc++abi CMakeFiles/test_xxx_import.dir/xxx_http_binding_test.cpp.o CMakeFiles/test_xxx_import.dir/resource_test.cpp.o CMakeFiles/test_xxx_import.dir/slugify_test.cpp.o CMakeFiles/test_xxx_import.dir/product_test.cpp.o CMakeFiles/test_xxx_import.dir/field_semantic_test.cpp.o CMakeFiles/test_xxx_import.dir/files.index-parser_test.cpp.o CMakeFiles/test_xxx_import.dir/thread_pool_test.cpp.o CMakeFiles/test_xxx_import.dir/container_sink_test.cpp.o CMakeFiles/test_xxx_import.dir/factories_test.cpp.o CMakeFiles/test_xxx_import.dir/thread_safe_queue_test.cpp.o CMakeFiles/test_xxx_import.dir/container_device_test.cpp.o CMakeFiles/test_xxx_import.dir/product_catalog_test.cpp.o CMakeFiles/test_xxx_import.dir/config_object_test.cpp.o CMakeFiles/test_xxx_import.dir/sha1_test.cpp.o CMakeFiles/test_xxx_import.dir/resize_test.cpp.o CMakeFiles/test_xxx_import.dir/redis_connection_test.cpp.o CMakeFiles/test_xxx_import.dir/redis_util_test.cpp.o CMakeFiles/test_xxx_import.dir/redis_product_test.cpp.o CMakeFiles/test_xxx_import.dir/redis_string_util_test.cpp.o CMakeFiles/test_xxx_import.dir/redis_task_queue_test.cpp.o CMakeFiles/test_xxx_import.dir/stream_manipulator_test.cpp.o CMakeFiles/test_xxx_import.dir/category_info_test.cpp.o CMakeFiles/test_xxx_import.dir/localized_string_test.cpp.o CMakeFiles/test_xxx_import.dir/product_description_test.cpp.o CMakeFiles/test_xxx_import.dir/product_picture_test.cpp.o CMakeFiles/test_xxx_import.dir/product_relation_test.cpp.o CMakeFiles/test_xxx_import.dir/supplier_test.cpp.o CMakeFiles/test_xxx_import.dir/summary_description_test.cpp.o CMakeFiles/test_xxx_import.dir/summary_descriptions_test.cpp.o CMakeFiles/test_xxx_import.dir/stage_base_test.cpp.o CMakeFiles/test_xxx_import.dir/thread_reclaimer_test.cpp.o CMakeFiles/test_xxx_import.dir/product_sheet_download_test.cpp.o CMakeFiles/test_xxx_import.dir/image_scaling_test.cpp.o CMakeFiles/test_xxx_import.dir/image_download_test.cpp.o CMakeFiles/test_xxx_import.dir/product_data_sheet_parser_test.cpp.o ../libxxx_import.a /usr/local/lib/libboost_unit_test_framework.a /usr/local/lib/libboost_thread.a /usr/local/lib/libboost_date_time.a /usr/local/lib/libGraphicsMagick++.a /usr/local/lib/libboost_filesystem.a /usr/local/lib/libboost_system.a /usr/local/lib/libboost_exception.a /usr/local/lib/libboost_chrono.a /usr/local/lib/libboost_log.a /usr/local/lib/libPocoNet.so /usr/local/lib/libPocoFoundation.so /usr/local/lib/libPocoNetSSL.so /usr/local/lib/libPocoUtil.so -Bstatic -lexpat -lhiredis -Bdynamic /usr/local/lib/libboost_date_time.a /usr/local/lib/libGraphicsMagick++.a -rpath /usr/local/lib -lc++ -lm -lgcc_s -lgcc -lc -lgcc_s -lgcc /usr/lib/gcc/x86_64-linux-gnu/4.8/crtend.o /usr/lib/gcc/x86_64-linux-gnu/4.8/../../../x86_64-linux-gnu/crtn.o
/usr/local/lib/libGraphicsMagick++.a(Image.o): In function `Magick::Image::signature(bool) const':
/home/xxx_import/temp/GraphicsMagick-1.3.18/Magick++/lib/Image.cpp:3271: undefined reference to `GetImageAttribute'
/home/xxx_import/temp/GraphicsMagick-1.3.18/Magick++/lib/Image.cpp:3274: undefined reference to `SignatureImage'
/home/xxx_import/temp/GraphicsMagick-1.3.18/Magick++/lib/Image.cpp:3278: undefined reference to `GetImageAttribute'
/usr/local/lib/libGraphicsMagick++.a(Image.o): In function `Magick::Image::read(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&)':

GraphicsMagick-1.3.18 was configured with following call:

CC=clang CXX=clang++ ./configure --with-jbig=yes --with-png=yes --with-jpeg=yes --enable-shared=yes CXXFLAGS="-O2 -g -stdlib=libc++  -isystem /usr/local/include/c++/v1/" LDFLAGS="-stdlib=libc++ -L/usr/local/lib/ -R/usr/local/lib/" LIBS="-lc++ -lc++abi"

and afterwards built and installed.

looking up the symbols manually are found as undefined:

nm /usr/local/lib/libGraphicsMagick++.a | grep GetImageAttribute
                 U GetImageAttribute

Attribute is found in /usr/local/lib/libGraphicsMagick.a.

My ldd output looks like:

ldd /usr/local/lib/libGraphicsMagick++.so
linux-vdso.so.1 =>  (0x00007fff78592000)
libGraphicsMagick.so.3 => /usr/local/lib/libGraphicsMagick.so.3 (0x00007fd0b0309000)
libjpeg.so.8 => /usr/lib/x86_64-linux-gnu/libjpeg.so.8 (0x00007fd0b00b0000)
libpng12.so.0 => /lib/x86_64-linux-gnu/libpng12.so.0 (0x00007fd0afe87000)
libbz2.so.1.0 => /lib/x86_64-linux-gnu/libbz2.so.1.0 (0x00007fd0afc77000)
libz.so.1 => /lib/x86_64-linux-gnu/libz.so.1 (0x00007fd0afa60000)
libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007fd0af842000)
libc++abi.so.1 => /usr/local/lib/libc++abi.so.1 (0x00007fd0af5f5000)
libc++.so.1 => /usr/local/lib/libc++.so.1 (0x00007fd0af351000)
libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007fd0af054000)
libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007fd0aec95000)
libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007fd0aea7f000)
/lib64/ld-linux-x86-64.so.2 (0x00007fd0b09c3000)
librt.so.1 => /lib/x86_64-linux-gnu/librt.so.1 (0x00007fd0ae876000)

It links against some C libraries from gcc toolchain. Should I build them also with clang? Any suggestions are really welcome.

Answer 1

Do you also explicitly link with dependencies of GraphicsMagick++? I think that might resolve your problem if you enumerate all the dependencies of GraphicsMagick++ as dependancies of produced executable, so link with these libs as well:

-lGraphicsMagick -ljpeg -lpng12 -lbz2 -lz

And see if you have less linking errors or none.