# Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
# file Copyright.txt or https://cmake.org/licensing for details.

#[=======================================================================[.rst:
CheckPrototypeDefinition
------------------------

Check if the prototype we expect is correct.

check_prototype_definition(FUNCTION PROTOTYPE RETURN HEADER VARIABLE)

::

  FUNCTION - The name of the function (used to check if prototype exists)
  PROTOTYPE- The prototype to check.
  RETURN - The return value of the function.
  HEADER - The header files required.
  VARIABLE - The variable to store the result.
             Will be created as an internal cache variable.

Example:

::

  check_prototype_definition(getpwent_r
   "struct passwd *getpwent_r(struct passwd *src, char *buf, int buflen)"
   "NULL"
   "unistd.h;pwd.h"
   SOLARIS_GETPWENT_R)

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

::

  CMAKE_REQUIRED_FLAGS = string of compile command line flags
  CMAKE_REQUIRED_DEFINITIONS = list of macros to define (-DFOO=bar)
  CMAKE_REQUIRED_INCLUDES = list of include directories
  CMAKE_REQUIRED_LIBRARIES = list of libraries to link
  CMAKE_REQUIRED_QUIET = execute quietly without messages
#]=======================================================================]

#

get_filename_component(__check_proto_def_dir "${CMAKE_CURRENT_LIST_FILE}" PATH)

include_guard(GLOBAL)

function(check_prototype_definition _FUNCTION _PROTOTYPE _RETURN _HEADER _VARIABLE)

  if (NOT DEFINED ${_VARIABLE})
    set(CHECK_PROTOTYPE_DEFINITION_CONTENT "/* */\n")

    set(CHECK_PROTOTYPE_DEFINITION_FLAGS ${CMAKE_REQUIRED_FLAGS})
    if (CMAKE_REQUIRED_LIBRARIES)
      set(CHECK_PROTOTYPE_DEFINITION_LIBS
        LINK_LIBRARIES ${CMAKE_REQUIRED_LIBRARIES})
    else()
      set(CHECK_PROTOTYPE_DEFINITION_LIBS)
    endif()
    if (CMAKE_REQUIRED_INCLUDES)
      set(CMAKE_SYMBOL_EXISTS_INCLUDES
        "-DINCLUDE_DIRECTORIES:STRING=${CMAKE_REQUIRED_INCLUDES}")
    else()
      set(CMAKE_SYMBOL_EXISTS_INCLUDES)
    endif()

    foreach(_FILE ${_HEADER})
      string(APPEND CHECK_PROTOTYPE_DEFINITION_HEADER
        "#include <${_FILE}>\n")
    endforeach()

    set(CHECK_PROTOTYPE_DEFINITION_SYMBOL ${_FUNCTION})
    set(CHECK_PROTOTYPE_DEFINITION_PROTO ${_PROTOTYPE})
    set(CHECK_PROTOTYPE_DEFINITION_RETURN ${_RETURN})

    configure_file("${__check_proto_def_dir}/CheckPrototypeDefinition.c.in"
      "${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/CheckPrototypeDefinition.c" @ONLY)

    file(READ ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/CheckPrototypeDefinition.c _SOURCE)

    try_compile(${_VARIABLE}
      ${CMAKE_BINARY_DIR}
      ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/CheckPrototypeDefinition.c
      COMPILE_DEFINITIONS ${CMAKE_REQUIRED_DEFINITIONS}
      ${CHECK_PROTOTYPE_DEFINITION_LIBS}
      CMAKE_FLAGS -DCOMPILE_DEFINITIONS:STRING=${CHECK_PROTOTYPE_DEFINITION_FLAGS}
      "${CMAKE_SYMBOL_EXISTS_INCLUDES}"
      OUTPUT_VARIABLE OUTPUT)

    if (${_VARIABLE})
      set(${_VARIABLE} 1 CACHE INTERNAL "Have correct prototype for ${_FUNCTION}")
      if(NOT CMAKE_REQUIRED_QUIET)
        message(STATUS "Checking prototype ${_FUNCTION} for ${_VARIABLE} - True")
      endif()
      file(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeOutput.log
        "Determining if the prototype ${_FUNCTION} exists for ${_VARIABLE} passed with the following output:\n"
        "${OUTPUT}\n\n")
    else ()
      if(NOT CMAKE_REQUIRED_QUIET)
        message(STATUS "Checking prototype ${_FUNCTION} for ${_VARIABLE} - False")
      endif()
      set(${_VARIABLE} 0 CACHE INTERNAL "Have correct prototype for ${_FUNCTION}")
      file(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeError.log
        "Determining if the prototype ${_FUNCTION} exists for ${_VARIABLE} failed with the following output:\n"
        "${OUTPUT}\n\n${_SOURCE}\n\n")
    endif ()
  endif()

endfunction()