Set an upper range of compiler versions for -Werror

This allows us to go back to older versions of Qt with newer compilers,
that didn't exist when those versions were released. It also allows
someone upgrading their compiler and not being faced with having to fix
all warnings before Qt compiles.

This commit whitelists the following compilers:
* Apple Clang versions 4.0, 4.1 and 4.2 (OS X only)
* Intel Compiler versions 13.0, 13.1 and 14.0 (Linux only)
* GCC versions 4.6, 4.7 and 4.8 (all OS)

Notably, Clang on other other OS besides OS X and MSVC are missing.

Change-Id: I665160d40a59336da1904f2a6c1eda543e592b48
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@digia.com>

1 files changed, 13 insertions, 11 deletions

diff --git a/mkspecs/features/qt_common.prf b/mkspecs/features/qt_common.prf
index 10b7736749..27dfb7adcb 100644
--- a/mkspecs/features/qt_common.prf
+++ b/mkspecs/features/qt_common.prf
@@ -24,15 +24,16 @@ warnings_are_errors:warning_clean {
     # This setting is compiler-dependent anyway because it depends on the version of the
     # compiler.
     clang {
-        # Apple clang 4.0+ or clang 3.1+
-        greaterThan(QT_CLANG_MAJOR_VERSION, 3) | \
-        if(equals(QT_CLANG_MAJOR_VERSION, 3):greaterThan(QT_CLANG_MINOR_VERSION, 1)) | \
-        greaterThan(QT_APPLE_CLANG_MAJOR_VERSION, 3) {
+        # Apple clang 4.0-4.2
+        # Regular clang is not tested
+        ver = $${QT_APPLE_CLANG_MAJOR_VERSION}.$${QT_APPLE_CLANG_MINOR_VERSION}
+        contains(ver, "4\\.[012]") {
             QMAKE_CXXFLAGS += -Werror -Wno-error=\\$${LITERAL_HASH}warnings $$WERROR
         }
-    } else:intel_icc {
-        # Intel CC 13.0+ (a.k.a. Intel Composer XE 2013)
-        greaterThan(QT_ICC_MAJOR_VERSION, 12) {
+    } else:intel_icc:linux {
+        # Intel CC 13.0 - 14.0, on Linux only
+        ver = $${QT_ICC_MAJOR_VERSION}.$${QT_ICC_MINOR_VERSION}
+        linux:contains(ver, "(13\\.|14\\.0)") {
             # 177: function "entity" was declared but never referenced
             #      (too aggressive; ICC reports even for functions created due to template instantiation)
             # 1224: #warning directive
@@ -40,10 +41,10 @@ warnings_are_errors:warning_clean {
             #      (NULL in C++ is usually a literal 0)
             QMAKE_CXXFLAGS += -Werror -ww177,1224,1881 $$WERROR
         }
-    } else:gcc {
-        # GCC 4.6+
-        # note: there was no GCC 3.6 and this assumes no one is crazy enough to compile Qt with GCC 2.7
-        greaterThan(QT_GCC_MAJOR_VERSION, 4)|greaterThan(QT_GCC_MINOR_VERSION, 5) {
+    } else:gcc:!clang:!intel_icc {
+        # GCC 4.6-4.8
+        ver = $${QT_GCC_MAJOR_VERSION}.$${QT_GCC_MINOR_VERSION}
+        contains(ver, "4\\.[678]") {
             QMAKE_CXXFLAGS += -Werror -Wno-error=cpp $$WERROR
 
             # GCC prints this bogus warning, after it has inlined a lot of code
@@ -51,4 +52,5 @@ warnings_are_errors:warning_clean {
             QMAKE_CXXFLAGS += -Wno-error=strict-overflow
         }
     }
+    unset(ver)
 }