Pass -fno-operator-names when supported

Summary:
Disables alternative tokens for &&, ||, etc.. They're are not supported
by MSVC out of the box, thus using them will limit the portability of
the code. There *are* options to make alternative tokens available under
MSVC [1], but I think we shouldn't promote the usage of them.

From the GCC documentation:
-fno-operator-names: Do not treat the operator name keywords and,
bitand, bitor, compl, not, or and xor as synonyms as keywords.

[1] http://stackoverflow.com/questions/555505/when-were-the-and-and-or-alternative-tokens-introduced-in-c

Reviewers: #frameworks, #buildsystem, ivan

Reviewed By: ivan

Subscribers: rakuco, elvisangelaccio

Differential Revision: https://phabricator.kde.org/D3850

1 files changed, 8 insertions, 0 deletions

diff --git a/kde-modules/KDECompilerSettings.cmake b/kde-modules/KDECompilerSettings.cmake
index 24eea3a7..583dfb57 100644
--- a/kde-modules/KDECompilerSettings.cmake
+++ b/kde-modules/KDECompilerSettings.cmake
@@ -211,6 +211,14 @@ if (CMAKE_C_COMPILER_ID STREQUAL "GNU" OR
     set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fno-common")
 endif()
 
+# Do not treat the operator name keywords and, bitand, bitor, compl, not, or and xor as synonyms as keywords.
+# They're not supported under Visual Studio out of the box thus using them limits the portability of code
+if (CMAKE_C_COMPILER_ID STREQUAL "GNU" OR
+        CMAKE_C_COMPILER_ID STREQUAL "Clang" OR
+        (CMAKE_C_COMPILER_ID STREQUAL "Intel" AND NOT WIN32))
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fno-operator-names")
+endif()
+
 # Default to hidden visibility for symbols
 set(CMAKE_C_VISIBILITY_PRESET hidden)
 set(CMAKE_CXX_VISIBILITY_PRESET hidden)