New in version 3.19.

Check if given source compiles and links into an executable.

check_source_compiles(<lang> <code> <resultVar>
                      [FAIL_REGEX <regex1> [<regex2>...]]
                      [SRC_EXT <extension>])

Check that the source supplied in <code> can be compiled as a source file for the requested language 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.

By default, the test source file will be given a file extension that matches the requested language. The SRC_EXT option can be used to override this with .<extension> instead.

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_source_compiles():


Additional flags to pass to the compiler. Note that the contents of CMAKE_<LANG>_FLAGS and its associated configuration-specific variable are automatically added to the compiler command before the contents of CMAKE_REQUIRED_FLAGS.


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.


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.


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


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).


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.