# Check if the system has the specified function; treat glibc "stub"

# functions as nonexistent:

# CHECK_FUNCTION_EXISTS_GLIBC (FUNCTION FUNCVAR)

#

#  FUNCTION - the function(s) where the prototype should be declared

#  FUNCVAR - variable to define if the function does exist

#

# In particular, this understands the glibc convention of

# defining macros __stub_XXXX or __stub___XXXX if the function

# does appear in the library but is merely a stub that does nothing.

# By detecting this case, we can select alternate behavior on

# platforms that don't support this functionality.

#

# The following variables may be set before calling this macro 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

# Copyright (c) 2009, Michihiro NAKAJIMA

#

# Redistribution and use is allowed according to the terms of the BSD license.

# For details see the accompanying COPYING-CMAKE-SCRIPTS file.

INCLUDE(CheckFunctionExists)

GET_FILENAME_COMPONENT(_selfdir_CheckFunctionExistsGlibc

	 "${CMAKE_CURRENT_LIST_FILE}" PATH)

MACRO (CHECK_FUNCTION_EXISTS_GLIBC _FUNC _FUNCVAR)

   IF(NOT DEFINED ${_FUNCVAR})

     SET(CHECK_STUB_FUNC_1 "__stub_${_FUNC}")

     SET(CHECK_STUB_FUNC_2 "__stub___${_FUNC}")

     CONFIGURE_FILE( ${_selfdir_CheckFunctionExistsGlibc}/CheckFuncs_stub.c.in

       ${CMAKE_CURRENT_BINARY_DIR}/cmake.tmp/CheckFuncs_stub.c IMMEDIATE)

     TRY_COMPILE(__stub

       ${CMAKE_CURRENT_BINARY_DIR}

       ${CMAKE_CURRENT_BINARY_DIR}/cmake.tmp/CheckFuncs_stub.c

       COMPILE_DEFINITIONS ${CMAKE_REQUIRED_DEFINITIONS}

       CMAKE_FLAGS

       -DCOMPILE_DEFINITIONS:STRING=${MACRO_CHECK_INCLUDE_FILE_FLAGS}

       "${CHECK_INCLUDE_FILE_C_INCLUDE_DIRS}")

     IF (__stub)

       SET("${_FUNCVAR}" "" CACHE INTERNAL "Have function ${_FUNC}")

     ELSE (__stub)

       CHECK_FUNCTION_EXISTS("${_FUNC}" "${_FUNCVAR}")

     ENDIF (__stub)

  ENDIF(NOT DEFINED ${_FUNCVAR})

ENDMACRO (CHECK_FUNCTION_EXISTS_GLIBC)