CheckSourceCompiles

New in version 3.19.

Check if given source compiles and links into an executable.

check_source_compiles

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. 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 compiler 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 <code> must contain a valid main program. For example:

check_source_compiles(C
"#include <stdlib.h>
#include <stdnoreturn.h>
noreturn void f(){ exit(0); }
int main(void) { f(); return 1; }"
HAVE_NORETURN)

check_source_compiles(Fortran
"program test
error stop
end program"
HAVE_ERROR_STOP)

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():

CMAKE_REQUIRED_FLAGS

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.

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

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

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.