Clang: Fix built-in's ExtractFunction action

Since

  Clang: Provide highlighting for identifier under cursor
  commit ca72c29462

the LocalUseMap, used for some refactoring actions, was not updated
anymore. Fall back to the built-in implementation for the LocalUseMap
because it contains pointers to built-in AST that clang obviously can't
provide.

Task-number: QTCREATORBUG-18607
Change-Id: I08762fe457835d4d83aca719febcb3497ee9696b
Reviewed-by: Ivan Donchevskii <ivan.donchevskii@qt.io>
Reviewed-by: Robert Loehning <robert.loehning@qt.io>
Reviewed-by: Marco Bubke <marco.bubke@qt.io>

src/plugins/cpptools/builtincursorinfo.cpp

@@ -47,7 +47,6 @@ using namespace CPlusPlus;
 using SemanticUses = QList<CppTools::SemanticInfo::Use>;
 
 namespace CppTools {
-namespace Internal {
 namespace {
 
 CursorInfo::Range toRange(const SemanticInfo::Use &use)
@@ -186,7 +185,8 @@ private:
     {
         CursorInfo result;
 
-        const CppTools::SemanticInfo::LocalUseMap localUses = findLocalUses();
+        const CppTools::SemanticInfo::LocalUseMap localUses
+                = BuiltinCursorInfo::findLocalUses(m_document, m_line, m_column);
         result.localUses = localUses;
         splitLocalUses(localUses, &result.useRanges, &result.unusedVariablesRanges);
 
@@ -200,16 +200,6 @@ private:
         return result; // OK, result.unusedVariablesRanges will be passed on
     }
 
-    CppTools::SemanticInfo::LocalUseMap findLocalUses() const
-    {
-        AST *ast = m_document->translationUnit()->ast();
-        FunctionDefinitionUnderCursor functionDefinitionUnderCursor(m_document->translationUnit());
-        DeclarationAST *declaration = functionDefinitionUnderCursor(ast,
-                                                                    static_cast<unsigned>(m_line),
-                                                                    static_cast<unsigned>(m_column));
-        return CppTools::LocalSymbols(m_document, declaration).uses;
-    }
-
     void splitLocalUses(const CppTools::SemanticInfo::LocalUseMap &uses,
                         CursorInfo::Ranges *rangesForLocalVariableUnderCursor,
                         CursorInfo::Ranges *rangesForLocalUnusedVariables) const
@@ -365,5 +355,15 @@ QFuture<CursorInfo> BuiltinCursorInfo::run(const CursorInfoParams &cursorInfoPar
     return Utils::runAsync(&FindUses::find, document, snapshot, line, column, scope, expression);
 }
 
-} // namespace Internal
+CppTools::SemanticInfo::LocalUseMap
+BuiltinCursorInfo::findLocalUses(const Document::Ptr &document, int line, int column)
+{
+    AST *ast = document->translationUnit()->ast();
+    FunctionDefinitionUnderCursor functionDefinitionUnderCursor(document->translationUnit());
+    DeclarationAST *declaration = functionDefinitionUnderCursor(ast,
+                                                                static_cast<unsigned>(line),
+                                                                static_cast<unsigned>(column));
+    return CppTools::LocalSymbols(document, declaration).uses;
+}
+
 } // namespace CppTools

src/plugins/cpptools/builtincursorinfo.h

@@ -26,17 +26,21 @@
 #pragma once
 
 #include "cppcursorinfo.h"
+#include "cpptools_global.h"
+
+#include <cplusplus/CppDocument.h>
 
 #include <QFuture>
 
 namespace CppTools {
-namespace Internal {
 
-class BuiltinCursorInfo
+class CPPTOOLS_EXPORT BuiltinCursorInfo
 {
 public:
     static QFuture<CursorInfo> run(const CursorInfoParams &params);
+
+    static CppTools::SemanticInfo::LocalUseMap
+    findLocalUses(const CPlusPlus::Document::Ptr &document, int line, int column);
 };
 
-} // namespace Internal
 } // namespace CppTools

src/plugins/cpptools/builtineditordocumentprocessor.cpp

@@ -257,7 +257,7 @@ bool BuiltinEditorDocumentProcessor::isParserRunning() const
 QFuture<CursorInfo>
 BuiltinEditorDocumentProcessor::cursorInfo(const CursorInfoParams &params)
 {
-    return Internal::BuiltinCursorInfo::run(params);
+    return BuiltinCursorInfo::run(params);
 }
 
 void BuiltinEditorDocumentProcessor::onParserFinished(CPlusPlus::Document::Ptr document,