Static build

[schmid786]

I'm trying to use nlopt-f in a statically compiled executable. But the build process of nlopt-f fails if BUILD_SHARED_LIBS=OFF is used.

# Building NLopt
cd nlopt
cmake -B build -S . -DBUILD_SHARED_LIBS=OFF -DCMAKE_INSTALL_PREFIX=install
cmake --build build
cmake --build build -t install

# Building nlopt-f
cd ../nlopt-f
cmake -B build -S . -DBUILD_SHARED_LIBS=OFF -DCMAKE_INSTALL_PREFIX=install -DNLopt_DIR=../nlopt/install/lib/cmake/nlopt
cmake --build build

Linker fails with undefined reference error. An excerpt of the log:

C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/12.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:/Users/<user>/nlopt/install/lib/libnlopt.a(local_optimizer.cc.obj):local_optimize:(.text+0xa3): undefined reference to `std::runtime_error::runtime_error(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/12.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:/Users/<user>/nlopt/install/lib/libnlopt.a(local_optimizer.cc.obj):local_optimize:(.text+0xb2): undefined reference to `operator delete(void*)'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/12.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:/Users/<user>/nlopt/install/lib/libnlopt.a(local_optimizer.cc.obj):local_optimize:(.text+0xb9): undefined reference to `std::runtime_error::~runtime_error()'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/12.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:/Users/<user>/nlopt/install/lib/libnlopt.a(local_optimizer.cc.obj):local_optimize:(.text+0xc8): undefined reference to `__cxa_throw'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/12.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:/Users/<user>/nlopt/install/lib/libnlopt.a(local_optimizer.cc.obj):local_optimize:(.text+0xd3): undefined reference to `__cxa_free_exception'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/12.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:/Users/<user>/nlopt/install/lib/libnlopt.a(local_optimizer.cc.obj):local_optimize:(.text+0xed): undefined reference to `operator delete(void*)'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/12.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:/Users/<user>/nlopt/install/lib/libnlopt.a(local_optimizer.cc.obj):local_optimize:(.text+0x42b): undefined reference to `operator new(unsigned long long)'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/12.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:/Users/<user>/nlopt/install/lib/libnlopt.a(local_optimizer.cc.obj):local_optimize:(.text+0x45c): undefined reference to `operator delete(void*)'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/12.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:/Users/<user>/nlopt/install/lib/libnlopt.a(local_optimizer.cc.obj):local_optimize:(.text+0xcf0): undefined reference to `std::__throw_length_error(char const*)'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/12.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:/Users/<user>/nlopt/install/lib/libnlopt.a(local_optimizer.cc.obj):local_optimize:(.xdata+0x10): undefined reference to `__gxx_personality_seh0'
collect2.exe: error: ld returned 1 exit status

If I build also the shared libraries of NLopt the build process of nlopt-f works but my executable has a dependency to the shared library of NLopt.

[schmid786]

I got it running. I don't know why, but for the static build it is necessary that the linking step is conducted by the c++ compiler instead of the fortran compiler. This can be achived with cmake by setting:

enable_language(CXX)
set_property(TARGET ${prog} PROPERTY LINKER_LANGUAGE CXX)

Maybe this should be implemented in nlopt-f.

[awvwgk]

If you link static libraries their link dependencies get promoted, in this case there is an indirect dependency on the C++ runtime from NLOpt itself. Defaulting to C++ for linking will probably not work in all cases, instead a new link library could be added (in fact it should be handled by NLOpt's CMake export).

[eibarra0]

Another workaround is to include the library "libstdc++" when linking, which has worked for me to operate on both nlopt and nlopt-f in static version.
As an example for building the test, these changes need to be made:

1. Modify the build manifest in the "fpm.toml" file to allow for the additional library

[build]
link = ["nlopt","stdc++"]

2. With compiling and linking the test files with:
   fpm test --link-flag "-Lpath/to/nlopt"