CMake/Modules/CheckStructHasMember.cmake
Peter Wu 384d3ce720 CheckStructHasMember: avoid breakage on -Wall -Werror (#15203)
With CMAKE_C_FLAGS='-Wall -Werror', this test breaks due to
-Werror=unused-value. Fix this by ignoring the return value.
2014-10-13 07:57:05 -04:00

86 lines
2.6 KiB
CMake

#.rst:
# CheckStructHasMember
# --------------------
#
# Check if the given struct or class has the specified member variable
#
# ::
#
# CHECK_STRUCT_HAS_MEMBER(<struct> <member> <header> <variable>
# [LANGUAGE <language>])
#
# ::
#
# <struct> - the name of the struct or class you are interested in
# <member> - the member which existence you want to check
# <header> - the header(s) where the prototype should be declared
# <variable> - variable to store the result
# <language> - the compiler to use (C or CXX)
#
#
#
# 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
# CMAKE_REQUIRED_LIBRARIES = list of libraries to link
# CMAKE_REQUIRED_QUIET = execute quietly without messages
#
#
#
# Example: CHECK_STRUCT_HAS_MEMBER("struct timeval" tv_sec sys/select.h
# HAVE_TIMEVAL_TV_SEC LANGUAGE C)
#=============================================================================
# Copyright 2007-2009 Kitware, Inc.
#
# Distributed under the OSI-approved BSD License (the "License");
# see accompanying file Copyright.txt for details.
#
# This software is distributed WITHOUT ANY WARRANTY; without even the
# implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
# See the License for more information.
#=============================================================================
# (To distribute this file outside of CMake, substitute the full
# License text for the above reference.)
include(CheckCSourceCompiles)
include(CheckCXXSourceCompiles)
macro (CHECK_STRUCT_HAS_MEMBER _STRUCT _MEMBER _HEADER _RESULT)
set(_INCLUDE_FILES)
foreach (it ${_HEADER})
set(_INCLUDE_FILES "${_INCLUDE_FILES}#include <${it}>\n")
endforeach ()
if("x${ARGN}" STREQUAL "x")
set(_lang C)
elseif("x${ARGN}" MATCHES "^xLANGUAGE;([a-zA-Z]+)$")
set(_lang "${CMAKE_MATCH_1}")
else()
message(FATAL_ERROR "Unknown arguments:\n ${ARGN}\n")
endif()
set(_CHECK_STRUCT_MEMBER_SOURCE_CODE "
${_INCLUDE_FILES}
int main()
{
${_STRUCT}* tmp;
(void) tmp->${_MEMBER};
return 0;
}
")
if("${_lang}" STREQUAL "C")
CHECK_C_SOURCE_COMPILES("${_CHECK_STRUCT_MEMBER_SOURCE_CODE}" ${_RESULT})
elseif("${_lang}" STREQUAL "CXX")
CHECK_CXX_SOURCE_COMPILES("${_CHECK_STRUCT_MEMBER_SOURCE_CODE}" ${_RESULT})
else()
message(FATAL_ERROR "Unknown language:\n ${_lang}\nSupported languages: C, CXX.\n")
endif()
endmacro ()