mirror of
https://github.com/microsoft/GSL.git
synced 2024-11-03 17:56:43 -05:00
475b785d2c
* Use CMAKE_CXX_STANDARD when available If the use has provided the variable CMAKE_CXX_STANDARD use that instead of providing a default cache variable. * Typo
62 lines
2.4 KiB
CMake
62 lines
2.4 KiB
CMake
# 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
|
|
if (DEFINED guideline_support_library_include_guard)
|
|
return()
|
|
endif()
|
|
set(guideline_support_library_include_guard ON)
|
|
|
|
function(gsl_set_default_cxx_standard min_cxx_standard)
|
|
set(GSL_CXX_STANDARD "${min_cxx_standard}" CACHE STRING "Use c++ standard")
|
|
|
|
set(GSL_CXX_STD "cxx_std_${GSL_CXX_STANDARD}")
|
|
|
|
if (MSVC)
|
|
set(GSL_CXX_STD_OPT "-std:c++${GSL_CXX_STANDARD}")
|
|
else()
|
|
set(GSL_CXX_STD_OPT "-std=c++${GSL_CXX_STANDARD}")
|
|
endif()
|
|
|
|
# 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)
|
|
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()
|
|
target_compile_features(GSL INTERFACE "${GSL_CXX_STD}")
|
|
# on *nix systems force the use of -std=c++XX instead of -std=gnu++XX (default)
|
|
set(CMAKE_CXX_EXTENSIONS OFF)
|
|
endif()
|
|
endfunction()
|
|
|
|
# The best way for a project to specify the GSL's C++ standard is by the client specifying
|
|
# the CMAKE_CXX_STANDARD. However, this isn't always ideal. Since the CMAKE_CXX_STANDARD is
|
|
# tied to the cmake version. And many projects have low cmake minimums.
|
|
#
|
|
# So provide an alternative approach in case that doesn't work.
|
|
function(gsl_client_set_cxx_standard min_cxx_standard)
|
|
if (DEFINED CMAKE_CXX_STANDARD)
|
|
if (${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()
|