# 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)