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Diffstat (limited to 'Modules/CheckCXXSourceCompiles.cmake')
| -rw-r--r-- | Modules/CheckCXXSourceCompiles.cmake | 83 |
1 files changed, 58 insertions, 25 deletions
diff --git a/Modules/CheckCXXSourceCompiles.cmake b/Modules/CheckCXXSourceCompiles.cmake index e54d09e..4634a7b 100644 --- a/Modules/CheckCXXSourceCompiles.cmake +++ b/Modules/CheckCXXSourceCompiles.cmake @@ -1,31 +1,64 @@ # Distributed under the OSI-approved BSD 3-Clause License. See accompanying # file Copyright.txt or https://cmake.org/licensing for details. -#.rst: -# CheckCXXSourceCompiles -# ---------------------- -# -# Check if given C++ source compiles and links into an executable -# -# CHECK_CXX_SOURCE_COMPILES(<code> <var> [FAIL_REGEX <fail-regex>]) -# -# :: -# -# <code> - source code to try to compile, must define 'main' -# <var> - variable to store whether the source code compiled -# Will be created as an internal cache variable. -# <fail-regex> - fail if test output matches this regex -# -# The following variables may be set before calling this macro to modify -# the way the check is run: -# -# :: -# -# CMAKE_REQUIRED_FLAGS = string of compile command line flags -# CMAKE_REQUIRED_DEFINITIONS = list of macros to define (-DFOO=bar) -# CMAKE_REQUIRED_INCLUDES = list of include directories -# CMAKE_REQUIRED_LIBRARIES = list of libraries to link -# CMAKE_REQUIRED_QUIET = execute quietly without messages +#[=======================================================================[.rst: +CheckCXXSourceCompiles +---------------------- + +Check if given C++ source compiles and links into an executable. + +.. command:: check_cxx_source_compiles + + :: + + check_cxx_source_compiles(code resultVar [FAIL_REGEX regex1 [regex2...]]) + + Check that the source supplied in ``code`` can be compiled as a C++ source + file and linked as an executable (so it must contain at least a ``main()`` + function). The result will be stored in the internal cache variable specified + by ``resultVar``, with a boolean true value for success and boolean false for + failure. If ``FAIL_REGEX`` is provided, then failure is determined by + checking if anything in the output matches any of the specified regular + expressions. + + The underlying check is performed by the :command:`try_compile` command. The + compile and link commands can be influenced by setting any of the following + variables prior to calling ``check_cxx_source_compiles()``: + + ``CMAKE_REQUIRED_FLAGS`` + Additional flags to pass to the compiler. Note that the contents of + :variable:`CMAKE_CXX_FLAGS <CMAKE_<LANG>_FLAGS>` and its associated + configuration-specific variable are automatically added to the compiler + command before the contents of ``CMAKE_REQUIRED_FLAGS``. + + ``CMAKE_REQUIRED_DEFINITIONS`` + A :ref:`;-list <CMake Language Lists>` of compiler definitions of the form + ``-DFOO`` or ``-DFOO=bar``. A definition for the name specified by + ``resultVar`` will also be added automatically. + + ``CMAKE_REQUIRED_INCLUDES`` + A :ref:`;-list <CMake Language Lists>` of header search paths to pass to + the compiler. These will be the only header search paths used by + ``try_compile()``, i.e. the contents of the :prop_dir:`INCLUDE_DIRECTORIES` + directory property will be ignored. + + ``CMAKE_REQUIRED_LIBRARIES`` + A :ref:`;-list <CMake Language Lists>` of libraries to add to the link + command. These can be the name of system libraries or they can be + :ref:`Imported Targets <Imported Targets>` (see :command:`try_compile` for + further details). + + ``CMAKE_REQUIRED_QUIET`` + If this variable evaluates to a boolean true value, all status messages + associated with the check will be suppressed. + + The check is only performed once, with the result cached in the variable + named by ``resultVar``. Every subsequent CMake run will re-use this cached + value rather than performing the check again, even if the ``code`` changes. + In order to force the check to be re-evaluated, the variable named by + ``resultVar`` must be manually removed from the cache. + +#]=======================================================================] macro(CHECK_CXX_SOURCE_COMPILES SOURCE VAR) if(NOT DEFINED "${VAR}") |