CheckPrototypeDefinition¶
Check if a C function has the expected prototype.
- check_prototype_definition¶
- check_prototype_definition(<function> <prototype> <return> <headers> <variable>) - <function>
- The name of the function whose prototype is being checked. 
- <prototype>
- The expected prototype of the function, provided as a string. 
- <return>
- The return value of the function. This will be used as a return value in the function definition body of the generated test program to verify that the function's return type matches the expected type. 
- <headers>
- A semicolon-separated list of header file names required for checking the function prototype. 
- <variable>
- The name of the variable to store the check result. This variable will be created as an internal cache variable. 
 - This command generates a test program and verifies that it builds without errors. The generated test program includes specified - <headers>, defines a function with given literal- <prototype>and- <return>value and then uses the specified- <function>. The simplified test program can be illustrated as:- #include <headers> // ... <prototype> { return <return>; } int main(...) { ...<function>()... } 
The following variables may be set before calling this function 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>_FLAGSand its associated configuration-specific variable are automatically added to the compiler command before the contents ofCMAKE_REQUIRED_FLAGS.
CMAKE_REQUIRED_DEFINITIONS
A ;-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_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_DIRECTORIESdirectory 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 if the getpwent_r() function on Solaris/illumos systems has the
expected prototype:
include(CheckPrototypeDefinition)
check_prototype_definition(
  getpwent_r
  "struct passwd *getpwent_r(struct passwd *src, char *buf, int buflen)"
  "NULL"
  "unistd.h;pwd.h"
  HAVE_SOLARIS_GETPWENT_R
)
