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Diffstat (limited to 'cmake/gsl_functions.cmake')
| -rw-r--r-- | cmake/gsl_functions.cmake | 72 |
1 files changed, 72 insertions, 0 deletions
diff --git a/cmake/gsl_functions.cmake b/cmake/gsl_functions.cmake new file mode 100644 index 0000000..b71747c --- /dev/null +++ b/cmake/gsl_functions.cmake @@ -0,0 +1,72 @@ +# This cmake module is meant to hold helper functions/macros +# that make maintaining the cmake build system much easier. +# This is especially helpful since gsl needs to provide coverage +# for multiple versions of cmake. +# +# Any functions/macros should have a gsl_* prefix to avoid problems + +function(gsl_set_default_cxx_standard min_cxx_standard) + set(GSL_CXX_STANDARD "${min_cxx_standard}" CACHE STRING "Use c++ standard") + + # when minimum version required is 3.8.0 remove if below + # both branches do exactly the same thing + if (CMAKE_VERSION VERSION_LESS 3.7.9) + if (MSVC) + set(GSL_CXX_STD_OPT "-std:c++${GSL_CXX_STANDARD}") + else() + set(GSL_CXX_STD_OPT "-std=c++${GSL_CXX_STANDARD}") + endif() + + include(CheckCXXCompilerFlag) + CHECK_CXX_COMPILER_FLAG("${GSL_CXX_STD_OPT}" COMPILER_SUPPORTS_CXX_STANDARD) + + if(COMPILER_SUPPORTS_CXX_STANDARD) + target_compile_options(GSL INTERFACE "${GSL_CXX_STD_OPT}") + else() + message(FATAL_ERROR "The compiler ${CMAKE_CXX_COMPILER} has no c++${GSL_CXX_STANDARD} support. Please use a different C++ compiler.") + endif() + else() + # Compiler must support at least this standard + target_compile_features(GSL INTERFACE "cxx_std_${GSL_CXX_STANDARD}") + # on *nix systems force the use of -std=c++XX instead of -std=gnu++XX (default) + set(CMAKE_CXX_EXTENSIONS OFF) + endif() +endfunction() + +# The best way for a project to specify the GSL's C++ standard is by the client specifying +# the CMAKE_CXX_STANDARD. However, this isn't always ideal. Since the CMAKE_CXX_STANDARD is +# tied to the cmake version. And many projects have low cmake minimums. +# +# So provide an alternative approach in case that doesn't work. +function(gsl_client_set_cxx_standard min_cxx_standard) + if (DEFINED CMAKE_CXX_STANDARD) + if (${CMAKE_CXX_STANDARD} VERSION_LESS ${min_cxx_standard}) + message(FATAL_ERROR "GSL: Requires at least CXX standard ${min_cxx_standard}, user provided ${CMAKE_CXX_STANDARD}") + endif() + + # Set the GSL standard to what the client desires + set(GSL_CXX_STANDARD "${CMAKE_CXX_STANDARD}" PARENT_SCOPE) + + # Exit out early to avoid extra unneccessary work + return() + endif() + + # Otherwise pick a reasonable default + gsl_set_default_cxx_standard(${min_cxx_standard}) +endfunction() + +# Adding the GSL.natvis files improves the debugging experience for users of this library. +function(gsl_add_native_visualizer_support) + if (CMAKE_VERSION VERSION_GREATER 3.7.8) + if (MSVC_IDE) + option(GSL_VS_ADD_NATIVE_VISUALIZERS "Configure project to use Visual Studio native visualizers" TRUE) + else() + set(GSL_VS_ADD_NATIVE_VISUALIZERS FALSE CACHE INTERNAL "Native visualizers are Visual Studio extension" FORCE) + endif() + + # add natvis file to the library so it will automatically be loaded into Visual Studio + if(GSL_VS_ADD_NATIVE_VISUALIZERS) + target_sources(GSL INTERFACE $<BUILD_INTERFACE:${GSL_SOURCE_DIR}/GSL.natvis>) + endif() + endif() +endfunction() |