From: Kornel Benko <kornel@lyx.org>
Date: Fri, 15 Jul 2016 08:37:18 +0000 (+0200)
Subject: Cmake build: Added code to compile with QT5.7
X-Git-Tag: 2.3.0alpha1~1263
X-Git-Url: https://git.lyx.org/gitweb/?a=commitdiff_plain;h=7eea0b6fa8942cef7f024fc77d1c10550ec68ef7;hp=19e0adb86bafc6e7a27267a2cacbff0029f5170a;p=features.git

Cmake build: Added code to compile with QT5.7

QT5.7 cmake config files explicitly instruct cmake to use `-std=gnu++11`.
This is not the same as is found by our FindCXX11Compiler.cmake,
which leads to compilation errors.
Here we overrule the setting.

Thanks to helpfull hand from Brad King <brad.king@kitware.com>
---

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 48688dced3..7fd8b26f76 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -572,7 +572,15 @@ if(NOT MSVC)
 	if(NOT LYX_QUIET)
 		set(CMAKE_VERBOSE_MAKEFILE ON)
 	endif()
-    set(LYX_CXX_FLAGS "-Wall -Wunused-parameter ${LYX_GCC11_MODE}")
+	set(LYX_CXX_FLAGS "-Wall -Wunused-parameter ${LYX_GCC11_MODE}")
+	if(LYX_CXX_FLAGS MATCHES "\\+\\+(14|11|98)")
+	  # Thanks to Brad King <brad.king@kitware.com>
+	  # for the pointer to https://cmake.org/cmake/help/v3.6/variable/CMAKE_CXX_STANDARD.html
+	  # This allows us to use QT5.7 with recent g++ (version >= 4.9) compilers
+	  # and still use our own c++ extension tests
+	  set(CMAKE_CXX_STANDARD ${CMAKE_MATCH_1})
+	  message(STATUS "CMAKE_CXX_STANDARD set to ${CMAKE_CXX_STANDARD}")
+	endif()
 	if(LYX_STDLIB_DEBUG)
 		set(LYX_CXX_FLAGS "${LYX_CXX_FLAGS} -D_GLIBCXX_DEBUG -D_GLIBCXX_DEBUG_PEDANTIC")
 	endif()