Clang: Highlight invalid declarations as text

...instead of the corresponding declaration color.

Task-number: QTCREATORBUG-18686
Change-Id: Ice4d84816351af79efa286f49516c392bd80da86
Reviewed-by: Ivan Donchevskii <ivan.donchevskii@qt.io>

src/tools/clangbackend/source/clangbackend_global.h

@@ -41,4 +41,9 @@ enum class PreferredTranslationUnit
 #  define IS_PRETTY_DECL_SUPPORTED
 #endif
 
+// CLANG-UPGRADE-CHECK: Remove IS_INVALIDDECL_SUPPORTED once we require clang >= 7.0
+#if defined(CINDEX_VERSION_HAS_ISINVALIDECL_BACKPORTED) || CINDEX_VERSION_MINOR >= 46
+#  define IS_INVALIDDECL_SUPPORTED
+#endif
+
 } // namespace ClangBackEnd

src/tools/clangbackend/source/cursor.cpp

@@ -29,6 +29,8 @@
 #include "sourcelocation.h"
 #include "sourcerange.h"
 
+#include "clangbackend_global.h"
+
 #include <ostream>
 
 namespace ClangBackEnd {
@@ -103,6 +105,15 @@ bool Cursor::isDeclaration() const
     return clang_isDeclaration(kind());
 }
 
+bool Cursor::isInvalidDeclaration() const
+{
+#ifdef IS_INVALIDDECL_SUPPORTED
+    return clang_isInvalidDeclaration(cxCursor);
+#else
+    return false;
+#endif
+}
+
 bool Cursor::isLocalVariable() const
 {
     switch (semanticParent().kind()) {

src/tools/clangbackend/source/cursor.h

@@ -61,6 +61,7 @@ public:
     bool isStaticMethod() const;
     bool isCompoundType() const;
     bool isDeclaration() const;
+    bool isInvalidDeclaration() const;
     bool isLocalVariable() const;
     bool isReference() const;
     bool isExpression() const;

src/tools/clangbackend/source/tokeninfo.cpp

@@ -308,6 +308,9 @@ void TokenInfo::identifierKind(const Cursor &cursor, Recursion recursion)
 {
     m_isIdentifier = (cursor.kind() != CXCursor_PreprocessingDirective);
 
+    if (cursor.isInvalidDeclaration())
+        return;
+
     switch (cursor.kind()) {
         case CXCursor_Destructor:
         case CXCursor_Constructor: