CheckCSourceCompiles

Check if given C source compiles and links into an executable.

check_c_source_compiles

check_c_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 try_compile() command. The compile and link commands can be influenced by setting any of the following variables prior to calling check_c_source_compiles():

CMAKE_REQUIRED_FLAGS

Additional flags to pass to the compiler. Note that the contents of CMAKE_C_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 ;-list 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 ;-list 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 INCLUDE_DIRECTORIES directory property will be ignored.

CMAKE_REQUIRED_LINK_OPTIONS

New in version 3.14.

A ;-list of options to add to the link command (see try_compile() for further details).

CMAKE_REQUIRED_LIBRARIES

A ;-list of libraries to add to the link command. These can be the name of system libraries or they can be Imported Targets (see try_compile() for further details).

CMAKE_REQUIRED_QUIET

New in version 3.1.

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.