lyx_mirror/development/cmake/modules/FindCXX11Compiler.cmake
Kornel Benko c7dbc201df Amend 9c863039: Cmake build: Adapt handling of c++ standards to new Visual C++ 2019
Apparently the use of "/std:c++20" is too new for our sources.
2020-06-04 18:01:49 +02:00

155 lines
4.3 KiB
CMake

# This file is part of lyx.
#
# The module comes from the enblend project, slightly modified.
#
# Check if compiler supports C++11 features
# and which compiler switches are necessary
# CXX11_FLAG : contains the necessary compiler flag
#
# Copyright (c) 2013 Thomas Modes <tmodes@@users.sourceforge.net>
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
#
# 1. Redistributions of source code must retain the copyright
# notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the copyright
# notice, this list of conditions and the following disclaimer in the
# documentation and/or other materials provided with the distribution.
# 3. The name of the author may not be used to endorse or promote products
# derived from this software without specific prior written permission.
#
# This file is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with lyx; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
#
INCLUDE(CheckCXXSourceCompiles)
INCLUDE(FindPackageHandleStandardArgs)
if (CMAKE_CXX_COMPILER_ID MATCHES "^([cC]lang|AppleClang)$")
set(CXX11_FLAG_CANDIDATES "--std=c++11 -Wno-deprecated-register")
else()
if (CYGWIN)
set(CXX11_FLAG_CANDIDATES "--std=gnu++11")
else()
if (MSVC)
# MSVC does not have a general C++11 flag, one can only switch off
# MS extensions with /Za in general or by extension with /Zc.
# Use an empty flag to ensure that CXX11_STD_REGEX is correctly set.
if (MSVC_VERSION LESS 1926)
set(CXX11_FLAG_CANDIDATES "noflagneeded")
else()
set(CXX11_FLAG_CANDIDATES
"/std:c++17"
"/std:c++14"
"noflagneeded")
endif()
else()
set(CXX11_FLAG_CANDIDATES
"--std=c++14"
"--std=c++11"
"--std=gnu++11"
"--std=gnu++0x"
)
endif()
endif()
endif()
# sample openmp source code to test
SET(CXX11_TEST_SOURCE
"
template <typename T>
struct check
{
static_assert(sizeof(int) <= sizeof(T), \"not big enough\");
};
typedef check<check<bool>> right_angle_brackets;
class TestDeleted
{
public:
TestDeleted() = delete;
};
int a;
decltype(a) b;
typedef check<int> check_type;
check_type c;
check_type&& cr = static_cast<check_type&&>(c);
auto d = a;
int main() {
return 0;
};
")
# The following code snipped taken from example in http://stackoverflow.com/questions/8561850/compile-stdregex-iterator-with-gcc
set(REGEX_TEST_SOURCE
"
#include <regex>
#include <iostream>
#include <string.h>
typedef std::regex_iterator<const char *> Myiter;
int main()
{
const char *pat = \"axayaz\";
Myiter::regex_type rx(\"a\");
Myiter next(pat, pat + strlen(pat), rx);
Myiter end;
return (0);
}
")
# check c compiler
set(SAFE_CMAKE_REQUIRED_QUIET ${CMAKE_REQUIRED_QUIET})
set(CMAKE_REQUIRED_QUIET ON)
SET(SAFE_CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS}")
FOREACH(FLAG ${CXX11_FLAG_CANDIDATES})
IF("${FLAG}" STREQUAL "noflagneeded")
UNSET(CMAKE_REQUIRED_FLAGS)
ELSE()
SET(CMAKE_REQUIRED_FLAGS "${FLAG}")
ENDIF()
UNSET(CXX11_FLAG_DETECTED CACHE)
CHECK_CXX_SOURCE_COMPILES("${CXX11_TEST_SOURCE}" CXX11_FLAG_DETECTED)
IF(CXX11_FLAG_DETECTED)
SET(CXX11_FLAG "${FLAG}")
message(STATUS "CXX11_FLAG_DETECTED = \"${FLAG}\"")
set(LYX_USE_CXX11 1)
check_cxx_source_compiles("${REGEX_TEST_SOURCE}" CXX_STD_REGEX_DETECTED)
if (CXX_STD_REGEX_DETECTED)
message(STATUS "Compiler supports std_regex")
set(CXX11_STD_REGEX ON)
else()
message(STATUS "Compiler does not support std_regex")
set(CXX11_STD_REGEX OFF)
endif()
break()
ENDIF()
ENDFOREACH()
SET(CMAKE_REQUIRED_FLAGS "${SAFE_CMAKE_REQUIRED_FLAGS}")
set(CMAKE_REQUIRED_QUIET ${SAFE_CMAKE_REQUIRED_QUIET})
# handle the standard arguments for find_package
FIND_PACKAGE_HANDLE_STANDARD_ARGS(CXX11Compiler DEFAULT_MSG CXX11_FLAG)
IF("${CXX11_FLAG}" STREQUAL "noflagneeded")
SET(CXX11_FLAG "")
ENDIF()
MARK_AS_ADVANCED(CXX11_FLAG CXX11_STD_REGEX)