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Diffstat (limited to 'Modules/CheckCCompilerFlag.cmake')
| -rw-r--r-- | Modules/CheckCCompilerFlag.cmake | 50 |
1 files changed, 30 insertions, 20 deletions
diff --git a/Modules/CheckCCompilerFlag.cmake b/Modules/CheckCCompilerFlag.cmake index 1ba67fc..5a7298b 100644 --- a/Modules/CheckCCompilerFlag.cmake +++ b/Modules/CheckCCompilerFlag.cmake @@ -1,26 +1,36 @@ # Distributed under the OSI-approved BSD 3-Clause License. See accompanying # file Copyright.txt or https://cmake.org/licensing for details. -#.rst: -# CheckCCompilerFlag -# ------------------ -# -# Check whether the C compiler supports a given flag. -# -# CHECK_C_COMPILER_FLAG(<flag> <var>) -# -# :: -# -# <flag> - the compiler flag -# <var> - variable to store the result -# Will be created as an internal cache variable. -# -# This internally calls the check_c_source_compiles macro and sets -# CMAKE_REQUIRED_DEFINITIONS to <flag>. See help for -# CheckCSourceCompiles 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: +CheckCCompilerFlag +------------------ + +Check whether the C compiler supports a given flag. + +.. command:: check_c_compiler_flag + + :: + + check_c_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_c_source_compiles`` macro from the +:module:`CheckCSourceCompiles` 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_C_FLAGS <CMAKE_<LANG>_FLAGS>`, unknown flags + in such variables may cause a false negative for this check. +#]=======================================================================] include(CheckCSourceCompiles) include(CMakeCheckCompilerFlagCommonPatterns) |