CheckFortranSourceCompiles

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

check_fortran_source_compiles

check_fortran_source_compiles(<code> <resultVar>
    [FAIL_REGEX <regex>...]
    [SRC_EXT <extension>]
)

Checks that the source supplied in <code> can be compiled as a Fortran source file and linked as an executable. The <code> must be a Fortran program containing at least an end statement–for example:

check_fortran_source_compiles("character :: b; error stop b; end" F2018ESTOPOK SRC_EXT F90)

This command can help avoid costly build processes when a compiler lacks support for a necessary feature, or a particular vendor library is not compatible with the Fortran compiler version being used. This generate-time check may advise the user of such before the main build process. See also the check_fortran_source_runs() command to actually run the compiled code.

The result will be stored in the internal cache variable <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 .F file extension. The SRC_EXT option can be used to override this with .<extension> instead– .F90 is a typical choice.

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_fortran_source_compiles():

CMAKE_REQUIRED_FLAGS

Additional flags to pass to the compiler. Note that the contents of CMAKE_Fortran_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.