CheckFunctionExists¶
Check if a C function can be linked
- check_function_exists¶
check_function_exists(<function> <variable>)
Checks that the
<function>is provided by libraries on the system and store the result in a<variable>, which will be created as an internal cache variable.
The following variables may be set before calling this macro to modify the way the check is run:
CMAKE_REQUIRED_FLAGSString of additional flags to pass to the compiler. The string must be space-delimited--a ;-list will not work. The contents of
CMAKE_<LANG>_FLAGSand its associated configuration-specific variable are automatically added to the compiler command before the contents ofCMAKE_REQUIRED_FLAGS.
CMAKE_REQUIRED_DEFINITIONSA ;-list of compiler definitions of the form
-DFOOor-DFOO=bar. A definition for the name specified by<resultVar>will also be added automatically.
CMAKE_REQUIRED_INCLUDESA ;-list of header search paths to pass to the compiler. These will be the only header search paths used--the contents of the
INCLUDE_DIRECTORIESdirectory property will be ignored.
CMAKE_REQUIRED_LINK_OPTIONSAdded in version 3.14.
A ;-list of options to add to the link command (see
try_compile()for further details).
CMAKE_REQUIRED_LIBRARIESA ;-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_QUIETAdded in version 3.1.
If this variable evaluates to a boolean true value, all status messages associated with the check will be suppressed.
Note
Prefer using CheckSymbolExists instead of this module,
for the following reasons:
check_function_exists()can't detect functions that are inlined in headers or specified as a macro.check_function_exists()can't detect anything in the 32-bit versions of the Win32 API, because of a mismatch in calling conventions.check_function_exists()only verifies linking, it does not verify that the function is declared in system headers.