Clang: Skip built-in includes when exporting the compilation database

We don't want to have compiler-specific paths there.

Change-Id: If26434ea3760d4f2ca4c25bbcf0340f4ea781072
Reviewed-by: Marco Bubke <marco.bubke@qt.io>

src/plugins/cpptools/compileroptionsbuilder.cpp

@@ -43,12 +43,14 @@ namespace CppTools {
 
 CompilerOptionsBuilder::CompilerOptionsBuilder(const ProjectPart &projectPart,
                                                UseSystemHeader useSystemHeader,
+                                               SkipBuiltIn skipBuiltInHeaderPaths,
                                                QString clangVersion,
                                                QString clangResourceDirectory)
     : m_projectPart(projectPart)
     , m_useSystemHeader(useSystemHeader)
     , m_clangVersion(clangVersion)
     , m_clangResourceDirectory(clangResourceDirectory)
+    , m_skipBuiltInHeaderPaths(skipBuiltInHeaderPaths)
 {
 }
 
@@ -237,7 +239,8 @@ void CompilerOptionsBuilder::addHeaderPathOptions()
 
     m_options.append(includes);
     m_options.append(systemIncludes);
-    m_options.append(builtInIncludes);
+    if (m_skipBuiltInHeaderPaths == SkipBuiltIn::No)
+        m_options.append(builtInIncludes);
 }
 
 void CompilerOptionsBuilder::addPrecompiledHeaderOptions(PchUsage pchUsage)

src/plugins/cpptools/compileroptionsbuilder.h

@@ -37,6 +37,12 @@ enum class UseSystemHeader
     No
 };
 
+enum class SkipBuiltIn
+{
+    Yes,
+    No
+};
+
 class CPPTOOLS_EXPORT CompilerOptionsBuilder
 {
 public:
@@ -47,6 +53,7 @@ public:
 
     CompilerOptionsBuilder(const ProjectPart &projectPart,
                            UseSystemHeader useSystemHeader = UseSystemHeader::No,
+                           SkipBuiltIn skipBuiltInHeaderPaths = SkipBuiltIn::No,
                            QString clangVersion = QString(),
                            QString clangResourceDirectory = QString());
     virtual ~CompilerOptionsBuilder() {}
@@ -106,6 +113,8 @@ private:
 
     QString m_clangVersion;
     QString m_clangResourceDirectory;
+
+    SkipBuiltIn m_skipBuiltInHeaderPaths;
 };
 
 } // namespace CppTools