From: ddzama <ddzama@opencascade.com>
Date: Wed, 4 May 2022 09:57:51 +0000 (+0300)
Subject: 0032921: Configuratiuon, CMake - allow selecting C++ standard
X-Git-Url: http://git.dev.opencascade.org/gitweb/?a=commitdiff_plain;h=293b9f436b5001bad5a5ca93a0e6881f230165f1;p=occt.git

0032921: Configuratiuon, CMake - allow selecting C++ standard

Make C++ standard to be enable from cmake settings:
Now, user can choose standard by setting cmake variable CPP_STANDARD.
Available next standard items: C++11, C++14, C++17, C++20, C++23.
---

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 23dd2d377b..feaff8d4ee 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -6,6 +6,10 @@ set (CMAKE_SUPPRESS_REGENERATION TRUE)
 
 set (CMAKE_CONFIGURATION_TYPES Release Debug RelWithDebInfo CACHE INTERNAL "" FORCE)
 
+# set using C++ standard
+set (BUILD_CPP_STANDARD "C++11" CACHE STRING "Select using c++ standard.")
+set_property(CACHE BUILD_CPP_STANDARD PROPERTY STRINGS "C++11" "C++14" "C++17" "C++20" "C++23")
+
 # macro: include patched file if it exists
 macro (OCCT_INCLUDE_CMAKE_FILE BEING_INCLUDED_FILE)
   if (BUILD_PATCH AND EXISTS "${BUILD_PATCH}/${BEING_INCLUDED_FILE}.cmake")
diff --git a/adm/cmake/occt_defs_flags.cmake b/adm/cmake/occt_defs_flags.cmake
index dc20cc283b..8da7008322 100644
--- a/adm/cmake/occt_defs_flags.cmake
+++ b/adm/cmake/occt_defs_flags.cmake
@@ -130,14 +130,25 @@ elseif (CMAKE_COMPILER_IS_GNUCC OR CMAKE_COMPILER_IS_GNUCXX OR "${CMAKE_CXX_COMP
   endif()
 endif()
 
+# Set desired C++ standard
+if     ("${BUILD_CPP_STANDARD}" STREQUAL "C++11")
+  set (CMAKE_CXX_STANDARD 11)
+elseif ("${BUILD_CPP_STANDARD}" STREQUAL "C++14")
+  set (CMAKE_CXX_STANDARD 14)
+elseif ("${BUILD_CPP_STANDARD}" STREQUAL "C++17")
+  set (CMAKE_CXX_STANDARD 17)
+elseif ("${BUILD_CPP_STANDARD}" STREQUAL "C++20")
+  set (CMAKE_CXX_STANDARD 20)
+elseif ("${BUILD_CPP_STANDARD}" STREQUAL "C++23")
+  set (CMAKE_CXX_STANDARD 23)
+else ()
+  message (FATAL_ERROR, "misprint in c++ standard name")
+endif()
+
 if ("x${CMAKE_CXX_COMPILER_ID}" STREQUAL "xClang")
   if (APPLE)
     # CLang can be used with both libstdc++ and libc++, however on OS X libstdc++ is outdated.
-    set (CMAKE_CXX_FLAGS "-std=c++0x -stdlib=libc++ ${CMAKE_CXX_FLAGS}")
-  elseif(NOT WIN32)
-    # CLang for Windows (at least CLang 8.0 distributed with VS 2019)
-    # does not support option "-std=c++0x"
-    set (CMAKE_CXX_FLAGS "-std=c++0x ${CMAKE_CXX_FLAGS}")
+    set (CMAKE_CXX_FLAGS "-stdlib=libc++ ${CMAKE_CXX_FLAGS}")
   endif()
   # Optimize size of binaries
   set (CMAKE_SHARED_LINKER_FLAGS "-Wl,-s ${CMAKE_SHARED_LINKER_FLAGS}")
@@ -148,14 +159,10 @@ elseif(MINGW)
   # workaround bugs in mingw with vtable export
   set (CMAKE_SHARED_LINKER_FLAGS "-Wl,--export-all-symbols")
 
-  # Require C++11
-  set (CMAKE_CXX_FLAGS "-std=gnu++0x ${CMAKE_CXX_FLAGS}")
   # Optimize size of binaries
   set (CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -s")
   set (CMAKE_C_FLAGS_RELEASE "${CMAKE_C_FLAGS_RELEASE} -s")
 elseif (DEFINED CMAKE_COMPILER_IS_GNUCXX)
-  # Require C++11
-  set (CMAKE_CXX_FLAGS "-std=c++0x ${CMAKE_CXX_FLAGS}")
   # Optimize size of binaries
   set (CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -s")
   set (CMAKE_C_FLAGS_RELEASE "${CMAKE_C_FLAGS_RELEASE} -s")
diff --git a/samples/java/jniviewer/app/src/main/jni/CMakeLists.txt b/samples/java/jniviewer/app/src/main/jni/CMakeLists.txt
index 59e131dfc0..eb41dc6fa0 100644
--- a/samples/java/jniviewer/app/src/main/jni/CMakeLists.txt
+++ b/samples/java/jniviewer/app/src/main/jni/CMakeLists.txt
@@ -37,7 +37,7 @@ list(APPEND aLibDeps lib_FreeType)
 # system libraries
 list(APPEND aLibDeps EGL GLESv2 log android)
 
-set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11 -Wall -frtti -fexceptions -fpermissive")
+set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++${CMAKE_CXX_STANDARD} -Wall -frtti -fexceptions -fpermissive")
 
 add_library(TKJniSample SHARED ${SOURCE_FILES})
 target_link_libraries(TKJniSample ${aLibDeps})