CMake/Modules/CheckStructHasMember.cmake
2019-05-14 15:26:46 -04:00

83 lines
2.4 KiB
CMake

# Distributed under the OSI-approved BSD 3-Clause License. See accompanying
# file Copyright.txt or https://cmake.org/licensing for details.
#[=======================================================================[.rst:
CheckStructHasMember
--------------------
Check if the given struct or class has the specified member variable
.. command:: CHECK_STRUCT_HAS_MEMBER
.. code-block:: cmake
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_LINK_OPTIONS = list of options to pass to link command
CMAKE_REQUIRED_LIBRARIES = list of libraries to link
CMAKE_REQUIRED_QUIET = execute quietly without messages
Example:
.. code-block:: cmake
CHECK_STRUCT_HAS_MEMBER("struct timeval" tv_sec sys/select.h
HAVE_TIMEVAL_TV_SEC LANGUAGE C)
#]=======================================================================]
include_guard(GLOBAL)
include(CheckCSourceCompiles)
include(CheckCXXSourceCompiles)
macro (CHECK_STRUCT_HAS_MEMBER _STRUCT _MEMBER _HEADER _RESULT)
set(_INCLUDE_FILES)
foreach (it ${_HEADER})
string(APPEND _INCLUDE_FILES "#include <${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 "
${_INCLUDE_FILES}
int main()
{
(void)sizeof(((${_STRUCT} *)0)->${_MEMBER});
return 0;
}
")
if("${_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 ()