CheckIncludeFile

Provides a macro to check if a header file can be included in C.

check_include_file
check_include_file(<include> <variable> [<flags>])

Check if the given <include> file may be included in a C source file and store the result in an internal cache entry named <variable>. The optional third argument may be used to add compilation flags to the check (or use CMAKE_REQUIRED_FLAGS below).

The following variables may be set before calling this macro to modify the way the check is run:

CMAKE_REQUIRED_FLAGS

String of additional flags to pass to the compiler. The string must be space-delimited--a ;-list will not work. 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--the contents of the INCLUDE_DIRECTORIES directory property will be ignored.

CMAKE_REQUIRED_LINK_OPTIONS

Added 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_LINK_DIRECTORIES

Added in version 3.31.

A ;-list of libraries search paths to pass to the linker (see try_compile() for further details).

CMAKE_REQUIRED_QUIET

Added in version 3.1.

If this variable evaluates to a boolean true value, all status messages associated with the check will be suppressed.

Examples

Checking whether the C header <unistd.h> exists and storing the check result in the HAVE_UNISTD_H cache variable:

include(CheckIncludeFile)

check_include_file(unistd.h HAVE_UNISTD_H)

See Also