[CMake] How can I control / debug linking arguments?

[Gabriel Archacki Hare]

I am trying to set up a cross-compile using FindCUDA to the TegraK1 architecture, which limits me to CUDA 6.5. Specifically, I have a subdirectory TestCUDA that compiles (using separable compilation) to a library libTestCUDA.a, which is then linked with code that is compiled using c++11 (which is not available in CUDA 6.5).

I can compile this by manually issuing build commands. And, I have set up the scripts so that in both OS X and Ubuntu compiling to the respective systems (not a cross-compile) works. However, when I try to cross compile, in the final linking stage 64 bit libraries are referenced, resulting in failure.

[100%] Linking CXX executable Test
/usr/local/bin/cmake -E cmake_link_script CMakeFiles/Test.dir/link.txt --verbose=1
/usr/bin/arm-linux-gnueabihf-g++   -std=c++11 -O3 -DNDEBUG   CMakeFiles/Test.dir/Test.cxx.o  -o Test /home/ghare/Documents/autowiring-build-tegrak1/lib/libAutowiring.a TestCUDA/libTestCUDA.a /usr/local/cuda-6.5/targets/armv7-linux-gnueabihf/lib/libcudart_static.a -lpthread /usr/lib/x86_64-linux-gnu/librt.so /usr/lib/x86_64-linux-gnu/libdl.so 
/usr/lib/x86_64-linux-gnu/librt.so: file not recognized: File format not recognized
collect2: error: ld returned 1 exit status

However, the following command successfully completes the compiling:
arm-linux-gnueabihf-g++ -mfloat-abi=hard -o Test  CMakeFiles/Test.dir/Test.cxx.o /home/ghare/Documents/autowiring-build-tegrak1/lib/libAutowiring.a TestCUDA/libTestCUDA.a -Xlinker --dynamic-linker=/lib/ld-linux-armhf.so.3 -L/usr/local/cuda-6.5/bin/../targets/armv7-linux-gnueabihf/lib/stubs -L/usr/local/cuda-6.5/bin/../targets/armv7-linux-gnueabihf/lib -lcudadevrt -lcudart_static -lrt -lpthread -ldl

All I need to do to have a complete cross-compile setup is to modify the linking…

-Gabriel


P. S. In case it will help, verbose output from the linking state follows:
Using built-in specs.
COLLECT_GCC=/usr/bin/arm-linux-gnueabihf-g++
COLLECT_LTO_WRAPPER=/usr/lib/gcc-cross/arm-linux-gnueabihf/4.8/lto-wrapper
Target: arm-linux-gnueabihf
Configured with: ../src/configure -v --with-pkgversion='Ubuntu/Linaro 4.8.2-16ubuntu4' --with-bugurl=file:///usr/share/doc/gcc-4.8/README.Bugs --enable-languages=c,c++,java,go,d,fortran,objc,obj-c++ --prefix=/usr --program-suffix=-4.8 --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --with-gxx-include-dir=/usr/arm-linux-gnueabihf/include/c++/4.8.2 --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --enable-gnu-unique-object --disable-libmudflap --disable-libitm --disable-libquadmath --enable-plugin --with-system-zlib --disable-browser-plugin --enable-java-awt=gtk --enable-gtk-cairo --with-java-home=/usr/lib/jvm/java-1.5.0-gcj-4.8-armhf-cross/jre --enable-java-home --with-jvm-root-dir=/usr/lib/jvm/java-1.5.0-gcj-4.8-armhf-cross --with-jvm-jar-dir=/usr/lib/jvm-exports/java-1.5.0-gcj-4.8-armhf-cross --with-arch-directory=arm --with-ecj-jar=/usr/share/java/eclipse-ecj.jar --disable-libgcj --enable-objc-gc --enable-multiarch --enable-multilib --disable-sjlj-exceptions --with-arch=armv7-a --with-fpu=vfpv3-d16 --with-float=hard --with-mode=thumb --disable-werror --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=arm-linux-gnueabihf --program-prefix=arm-linux-gnueabihf- --includedir=/usr/arm-linux-gnueabihf/include
Thread model: posix
gcc version 4.8.2 (Ubuntu/Linaro 4.8.2-16ubuntu4) 
COMPILER_PATH=/usr/lib/gcc-cross/arm-linux-gnueabihf/4.8/:/usr/lib/gcc-cross/arm-linux-gnueabihf/4.8/:/usr/lib/gcc-cross/arm-linux-gnueabihf/:/usr/lib/gcc-cross/arm-linux-gnueabihf/4.8/:/usr/lib/gcc-cross/arm-linux-gnueabihf/:/usr/lib/gcc-cross/arm-linux-gnueabihf/4.8/../../../../arm-linux-gnueabihf/bin/
LIBRARY_PATH=/usr/lib/gcc-cross/arm-linux-gnueabihf/4.8/:/usr/lib/gcc-cross/arm-linux-gnueabihf/4.8/../../../../arm-linux-gnueabihf/lib/../lib/:/lib/../lib/:/usr/lib/../lib/:/usr/lib/gcc-cross/arm-linux-gnueabihf/4.8/../../../../arm-linux-gnueabihf/lib/:/lib/:/usr/lib/
COLLECT_GCC_OPTIONS='-v' '-std=c++11' '-O3' '-D' 'NDEBUG' '-o' 'Test' '-shared-libgcc' '-march=armv7-a' '-mfloat-abi=hard' '-mfpu=vfpv3-d16' '-mthumb' '-mtls-dialect=gnu'
 /usr/lib/gcc-cross/arm-linux-gnueabihf/4.8/collect2 --sysroot=/ --build-id --eh-frame-hdr -dynamic-linker /lib/ld-linux-armhf.so.3 -X --hash-style=gnu --as-needed -m armelf_linux_eabi -z relro -o Test /usr/lib/gcc-cross/arm-linux-gnueabihf/4.8/../../../../arm-linux-gnueabihf/lib/../lib/crt1.o /usr/lib/gcc-cross/arm-linux-gnueabihf/4.8/../../../../arm-linux-gnueabihf/lib/../lib/crti.o /usr/lib/gcc-cross/arm-linux-gnueabihf/4.8/crtbegin.o -L/usr/lib/gcc-cross/arm-linux-gnueabihf/4.8 -L/usr/lib/gcc-cross/arm-linux-gnueabihf/4.8/../../../../arm-linux-gnueabihf/lib/../lib -L/lib/../lib -L/usr/lib/../lib -L/usr/lib/gcc-cross/arm-linux-gnueabihf/4.8/../../../../arm-linux-gnueabihf/lib CMakeFiles/Test.dir/Test.cxx.o /home/ghare/Documents/autowiring-build-tegrak1/lib/libAutowiring.a TestCUDA/libTestCUDA.a /usr/local/cuda-6.5/targets/armv7-linux-gnueabihf/lib/libcudart_static.a -lpthread /usr/lib/x86_64-linux-gnu/librt.so /usr/lib/x86_64-linux-gnu/libdl.so -lstdc++ -lm -lgcc_s -lgcc -lc -lgcc_s -lgcc /usr/lib/gcc-cross/arm-linux-gnueabihf/4.8/crtend.o /usr/lib/gcc-cross/arm-linux-gnueabihf/4.8/../../../../arm-linux-gnueabihf/lib/../lib/crtn.o
/usr/lib/x86_64-linux-gnu/librt.so: file not recognized: File format not recognized
collect2: error: ld returned 1 exit status