diff options
Diffstat (limited to 'Modules/CheckCXXCompilerFlag.cmake')
-rw-r--r-- | Modules/CheckCXXCompilerFlag.cmake | 49 |
1 files changed, 30 insertions, 19 deletions
diff --git a/Modules/CheckCXXCompilerFlag.cmake b/Modules/CheckCXXCompilerFlag.cmake index afbb231..f731b70 100644 --- a/Modules/CheckCXXCompilerFlag.cmake +++ b/Modules/CheckCXXCompilerFlag.cmake @@ -1,25 +1,36 @@ # Distributed under the OSI-approved BSD 3-Clause License. See accompanying # file Copyright.txt or https://cmake.org/licensing for details. -#.rst: -# CheckCXXCompilerFlag -# -------------------- -# -# Check whether the CXX compiler supports a given flag. -# -# CHECK_CXX_COMPILER_FLAG(<flag> <var>) -# -# :: -# -# <flag> - the compiler flag -# <var> - variable to store the result -# -# This internally calls the check_cxx_source_compiles macro and sets -# CMAKE_REQUIRED_DEFINITIONS to <flag>. See help for -# CheckCXXSourceCompiles for a listing of variables that can otherwise -# modify the build. The result only tells that the compiler does not -# give an error message when it encounters the flag. If the flag has -# any effect or even a specific one is beyond the scope of this module. +#[=======================================================================[.rst: +CheckCXXCompilerFlag +------------------------ + +Check whether the CXX compiler supports a given flag. + +.. command:: check_cxx_compiler_flag + + :: + + check_cxx_compiler_flag(<flag> <var>) + + Check that the ``<flag>`` is accepted by the compiler without + a diagnostic. Stores the result in an internal cache entry + named ``<var>``. + +This command temporarily sets the ``CMAKE_REQUIRED_DEFINITIONS`` variable +and calls the ``check_cxx_source_compiles`` macro from the +:module:`CheckCXXSourceCompiles` module. See documentation of that +module for a listing of variables that can otherwise modify the build. + +A positive result from this check indicates only that the compiler did not +issue a diagnostic message when given the flag. Whether the flag has any +effect or even a specific one is beyond the scope of this module. + +.. note:: + Since the :command:`try_compile` command forwards flags from variables + like :variable:`CMAKE_CXX_FLAGS <CMAKE_<LANG>_FLAGS>`, unknown flags + in such variables may cause a false negative for this check. +#]=======================================================================] include(CheckCXXSourceCompiles) include(CMakeCheckCompilerFlagCommonPatterns) |