From: vsr <vsr@opencascade.com>
Date: Mon, 14 Sep 2020 08:50:01 +0000 (+0300)
Subject: Correctly set C++ standard (default value is set to 11)
X-Git-Tag: V2_4_5~4
X-Git-Url: http://git.salome-platform.org/gitweb/?a=commitdiff_plain;h=79ce1736c8b18ebc2110968661fcaf5db501b7d3;p=tools%2Flibbatch.git

Correctly set C++ standard (default value is set to 11)
---

diff --git a/CMakeLists.txt b/CMakeLists.txt
index c97961f..841de12 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -63,23 +63,27 @@ ENDIF()
 
 INCLUDE(CheckCXXCompilerFlag)
 
-SET(LIBBATCH_NO_CXX11_SUPPORT FALSE CACHE BOOL "Switch OFF C++-11 standard")
-IF(NOT LIBBATCH_NO_CXX11_SUPPORT)
-  # C++11 support
-  CHECK_CXX_COMPILER_FLAG("-std=c++11" COMPILER_SUPPORTS_CXX11)
-  IF(COMPILER_SUPPORTS_CXX11)
-    MESSAGE(STATUS "Enable C++11 support")
-    SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11")
-  ELSE()
-    CHECK_CXX_COMPILER_FLAG("-std=c++0x" COMPILER_SUPPORTS_CXX0X)
-    IF(COMPILER_SUPPORTS_CXX0X)
-      MESSAGE(STATUS "Enable C++0x support")
-      SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++0x")
-    ELSE()
-      MESSAGE(WARNING "Compiler ${CMAKE_CXX_COMPILER} has no C++11 support.")
-    ENDIF()
+# Option: C++ standard to use
+# Note: CMake by default enables C++ extensions; they can be disabled by additionally
+#       specifying -DCMAKE_CXX_EXTENSIONS=OFF
+SET(LIBBATCH_CXX_STANDARD 11 CACHE STRING "C++ standard to use")
+SET(_supported_standards 11 14 17 20)
+SET(_standard_ok FALSE)
+FOREACH(_standard ${_supported_standards})
+  IF(LIBBATCH_CXX_STANDARD STREQUAL _standard)
+    SET(_standard_ok TRUE)
+    BREAK()
   ENDIF()
+ENDFOREACH()
+IF(NOT _standard_ok)
+  MESSAGE(FATAL_ERROR "Unsupported C++ standard: ${LIBBATCH_CXX_STANDARD}; allowed values: ${_supported_standards}")
 ENDIF()
+UNSET(_supported_standards)
+UNSET(_standard)
+UNSET(_standard_ok)
+MESSAGE(STATUS "Setting C++ standard to ${LIBBATCH_CXX_STANDARD}")
+SET(CMAKE_CXX_STANDARD ${LIBBATCH_CXX_STANDARD})
+SET(CMAKE_CXX_STANDARD_REQUIRED ON)
 
 IF(NOT (WIN32 OR APPLE))
   SET(LIBBATCH_DEBUG_WARNINGS FALSE CACHE BOOL "Print more compiler warnings")