Clang: Put clang's resource dir after /usr/local/include

...also on Linux.

That's what clang invoked from the command line does.

Change-Id: I59c48d11fab3b944bb42ca7bb4cd9093a735df60
Reviewed-by: Cristian Adam <cristian.adam@qt.io>
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@qt.io>

src/plugins/cpptools/headerpathfilter.cpp

@@ -120,24 +120,19 @@ QString clangIncludeDirectory(const QString &clangVersion, const QString &clangR
 #endif
 }
 
-HeaderPaths::iterator resourceIterator(HeaderPaths &headerPaths, bool isMacOs)
+HeaderPaths::iterator resourceIterator(HeaderPaths &headerPaths)
 {
     // include/c++, include/g++, libc++\include and libc++abi\include
     static const QString cppIncludes = R"((.*/include/.*(g\+\+|c\+\+).*))"
                                        R"(|(.*libc\+\+/include))"
-                                       R"(|(.*libc\+\+abi/include))";
+                                       R"(|(.*libc\+\+abi/include))"
+                                       R"(|(/usr/local/include))";
     static const QRegularExpression includeRegExp("\\A(" + cppIncludes + ")\\z");
 
-    // The same as includeRegExp but also matches /usr/local/include
-    static const QRegularExpression includeRegExpMac("\\A(" + cppIncludes
-                                                     + R"(|(/usr/local/include))" + ")\\z");
-
-    const QRegularExpression &includePathRegEx = isMacOs ? includeRegExpMac : includeRegExp;
-
     return std::stable_partition(headerPaths.begin(),
                                  headerPaths.end(),
                                  [&](const HeaderPath &headerPath) {
-                                     return includePathRegEx.match(headerPath.path).hasMatch();
+                                     return includeRegExp.match(headerPath.path).hasMatch();
                                  });
 }
 
@@ -165,8 +160,7 @@ void HeaderPathFilter::tweakHeaderPaths()
     removeClangSystemHeaderPaths(builtInHeaderPaths);
     removeGccInternalIncludePaths();
 
-    auto split = resourceIterator(builtInHeaderPaths,
+    auto split = resourceIterator(builtInHeaderPaths);
-                                  projectPart.toolChainTargetTriple.contains("darwin"));
 
     if (!clangVersion.isEmpty()) {
         const QString clangIncludePath = clangIncludeDirectory(clangVersion, clangResourceDirectory);

tests/unit/unittest/compileroptionsbuilder-test.cpp

@@ -351,10 +351,10 @@ TEST_F(CompilerOptionsBuilder, ClangHeadersAndCppIncludesPathsOrderLinux)
             QDir::toNativeSeparators(
                 "/usr/lib/gcc/x86_64-linux-gnu/4.8/../../../../include/x86_64-linux-gnu/c++/4.8"),
             "-isystem",
-            QDir::toNativeSeparators(CLANG_RESOURCE_DIR ""),
-            "-isystem",
             QDir::toNativeSeparators("/usr/local/include"),
             "-isystem",
+            QDir::toNativeSeparators(CLANG_RESOURCE_DIR ""),
+            "-isystem",
             QDir::toNativeSeparators("/usr/lib/gcc/x86_64-linux-gnu/4.8/include"),
             "-isystem",
             QDir::toNativeSeparators("/usr/include/x86_64-linux-gnu"),

tests/unit/unittest/headerpathfilter-test.cpp

@@ -241,8 +241,8 @@ TEST_F(HeaderPathFilter, ClangHeadersAndCppIncludesPathsOrderLinux)
                                        "c++/4.8/backward"),
                             HasBuiltIn("/usr/lib/gcc/x86_64-linux-gnu/4.8/../../../../include/"
                                        "x86_64-linux-gnu/c++/4.8"),
-                            HasBuiltIn(CLANG_RESOURCE_DIR),
                             HasBuiltIn("/usr/local/include"),
+                            HasBuiltIn(CLANG_RESOURCE_DIR),
                             HasBuiltIn("/usr/lib/gcc/x86_64-linux-gnu/4.8/include"),
                             HasBuiltIn("/usr/include/x86_64-linux-gnu"),
                             HasBuiltIn("/usr/include"),