Clang: Use follow symbol result from clang when global fails

When built-in code model fails to follow symbol under cursor
fall back to the clang result even if it only follows
to the decalration.

Change-Id: I22d8c5fee6ab7594b1d1b7ce8104414db28383c7
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@qt.io>

src/tools/clangbackend/source/clangfollowsymbol.cpp

@@ -146,10 +146,10 @@ static int getTokenIndex(CXTranslationUnit tu, const Tokens &tokens, uint line,
     return tokenIndex;
 }
 
-SourceRangeContainer FollowSymbol::followSymbol(CXTranslationUnit tu,
-                                                const Cursor &fullCursor,
-                                                uint line,
-                                                uint column)
+FollowSymbolResult FollowSymbol::followSymbol(CXTranslationUnit tu,
+                                              const Cursor &fullCursor,
+                                              uint line,
+                                              uint column)
 {
     std::unique_ptr<Tokens> tokens(new Tokens(fullCursor));
 
@@ -175,7 +175,7 @@ SourceRangeContainer FollowSymbol::followSymbol(CXTranslationUnit tu,
         CXFile file = clang_getIncludedFile(cursors[tokenIndex]);
         const ClangString filename(clang_getFileName(file));
         const SourceLocation loc(tu, filename, 1, 1);
-        return SourceRange(loc, loc);
+        return SourceRangeContainer(SourceRange(loc, loc));
     }
 
     // For definitions we can always find a declaration in current TU
@@ -185,12 +185,16 @@ SourceRangeContainer FollowSymbol::followSymbol(CXTranslationUnit tu,
     if (!cursor.isDeclaration()) {
         // This is the symbol usage
         // We want to return definition
+        FollowSymbolResult result;
         cursor = cursor.referenced();
-        if (cursor.isNull() || !cursor.isDefinition()) {
-            // We can't find definition in this TU
+        if (cursor.isNull())
             return SourceRangeContainer();
+        if (!cursor.isDefinition()) {
+            // We can't find definition in this TU
+            result.isPureDeclarationForUsage = true;
         }
-        return extractMatchingTokenRange(cursor, tokenSpelling);
+        result.range = extractMatchingTokenRange(cursor, tokenSpelling);
+        return result;
     }
 
     cursor = cursor.definition();

src/tools/clangbackend/source/clangfollowsymbol.h

@@ -33,17 +33,18 @@ class Utf8String;
 
 namespace ClangBackEnd {
 
-class Cursor;
-class SourceRangeContainer;
 class CommandLineArguments;
+class Cursor;
+class FollowSymbolResult;
+class SourceRangeContainer;
 
 class FollowSymbol
 {
 public:
-    static SourceRangeContainer followSymbol(CXTranslationUnit tu,
-                                             const Cursor &fullCursor,
-                                             uint line,
-                                             uint column);
+    static FollowSymbolResult followSymbol(CXTranslationUnit tu,
+                                           const Cursor &fullCursor,
+                                           uint line,
+                                           uint column);
 };
 
 } // namespace ClangBackEnd

src/tools/clangbackend/source/clangfollowsymboljob.h

@@ -27,14 +27,15 @@
 
 #include "clangdocumentjob.h"
 
+#include <clangsupport/followsymbolmessage.h>
 #include <clangsupport/sourcerangecontainer.h>
 
 namespace ClangBackEnd {
 
-class FollowSymbolJob : public DocumentJob<SourceRangeContainer>
+class FollowSymbolJob : public DocumentJob<FollowSymbolResult>
 {
 public:
-    using AsyncResult = SourceRangeContainer;
+    using AsyncResult = FollowSymbolResult;
 
     AsyncPrepareResult prepareAsyncRun() override;
     void finalizeAsyncRun() override;

src/tools/clangbackend/source/clangtranslationunit.cpp

@@ -269,7 +269,7 @@ void TranslationUnit::extractDiagnostics(DiagnosticContainer &firstHeaderErrorDi
     }
 }
 
-SourceRangeContainer TranslationUnit::followSymbol(uint line, uint column) const
+FollowSymbolResult TranslationUnit::followSymbol(uint line, uint column) const
 {
     return FollowSymbol::followSymbol(m_cxTranslationUnit, cursorAt(line, column), line, column);
 }

src/tools/clangbackend/source/clangtranslationunit.h

@@ -37,6 +37,7 @@ namespace ClangBackEnd {
 class Cursor;
 class DiagnosticContainer;
 class DiagnosticSet;
+class FollowSymbolResult;
 class ReferencesResult;
 class SkippedSourceRanges;
 class SourceLocation;
@@ -108,7 +109,7 @@ public:
     TokenProcessor<FullTokenInfo> fullTokenInfosInRange(const SourceRange &range) const;
 
     SkippedSourceRanges skippedSourceRanges() const;
-    SourceRangeContainer followSymbol(uint line, uint column) const;
+    FollowSymbolResult followSymbol(uint line, uint column) const;
 
 private:
     const Utf8String m_id;