C++: Fix crash when deducing auto (with invalid ids)

Task-number: QTCREATORBUG-7801

Change-Id: I61436148ed1428a50a6840ba9109310a57dabaa4
Reviewed-by: Roberto Raggi <roberto.raggi@nokia.com>

src/libs/cplusplus/LookupContext.cpp

@@ -88,7 +88,9 @@ static void path_helper(Symbol *symbol, QList<const Name *> *names)
     }
 }
 
-static bool compareName(const Name *name, const Name *other)
+namespace CPlusPlus {
+
+bool compareName(const Name *name, const Name *other)
 {
     if (name == other)
         return true;
@@ -104,8 +106,6 @@ static bool compareName(const Name *name, const Name *other)
     return false;
 }
 
-namespace CPlusPlus {
-
 bool compareFullyQualifiedName(const QList<const Name *> &path, const QList<const Name *> &other)
 {
     if (path.length() != other.length())

src/libs/cplusplus/LookupContext.h

@@ -252,6 +252,7 @@ private:
     QSharedPointer<Control> _control;
 };
 
+bool CPLUSPLUS_EXPORT compareName(const Name *name, const Name *other);
 bool CPLUSPLUS_EXPORT compareFullyQualifiedName(const QList<const Name *> &path,
                                                 const QList<const Name *> &other);
 

src/libs/cplusplus/ResolveExpression.cpp

@@ -473,27 +473,38 @@ bool ResolveExpression::visit(SimpleNameAST *ast)
         if (item.declaration() == 0)
             continue;
 
-        if (item.type().isAuto()) {
+        if (item.type().isAuto()
+                && _blockedIds.find(ast->name->identifier()) == _blockedIds.end()) {
             const Declaration *decl = item.declaration()->asDeclaration();
             if (!decl)
                 continue;
 
-            Document::Ptr doc = _context.snapshot().document(decl->fileName());
-
             const StringLiteral *initializationString = decl->getInitializer();
             if (initializationString == 0)
                 continue;
 
-            QByteArray initializer = QByteArray::fromRawData(initializationString->chars(), initializationString->size()).trimmed();
+            const QByteArray &initializer =
+                    QByteArray::fromRawData(initializationString->chars(),
+                                            initializationString->size()).trimmed();
 
             // Skip lambda-function initializers
             if (initializer.length() > 0 && initializer[0] == '[')
                 continue;
 
             TypeOfExpression exprTyper;
+            Document::Ptr doc = _context.snapshot().document(decl->fileName());
             exprTyper.init(doc, _context.snapshot(), _context.bindings());
 
-            QList<LookupItem> typeItems = exprTyper(initializer, decl->enclosingScope(), TypeOfExpression::Preprocess);
+            Document::Ptr exprDoc =
+                    documentForExpression(exprTyper.preprocessedExpression(initializer));
+            exprDoc->check();
+            ExpressionAST *exprAST = extractExpressionAST(exprDoc);
+            if (!exprAST)
+                continue;
+
+            _blockedIds.insert(ast->name->identifier());
+            const QList<LookupItem> &typeItems = resolve(exprAST, decl->enclosingScope());
+            _blockedIds.erase(ast->name->identifier());
             if (typeItems.empty())
                 continue;
 

src/libs/cplusplus/ResolveExpression.h

@@ -36,6 +36,7 @@
 #include <ASTVisitor.h>
 #include <FullySpecifiedType.h>
 #include <Bind.h>
+#include <set>
 
 namespace CPlusPlus {
 
@@ -118,12 +119,20 @@ protected:
     // Objective-C expressions
     virtual bool visit(ObjCMessageExpressionAST *ast);
 
+
 private:
+    struct IdentifierComp
+    {
+        bool operator()(const Identifier *a, const Identifier *b) const
+        { return strcmp(a->chars(), b->chars()) < 0; }
+    };
+
     Scope *_scope;
     LookupContext _context;
     Bind bind;
     QList<LookupItem> _results;
     bool _reference;
+    std::set<const Identifier *, IdentifierComp> _blockedIds; // Replace by a hash impl.
 };
 
 } // namespace CPlusPlus

src/libs/cplusplus/TypeOfExpression.cpp

@@ -163,23 +163,6 @@ ExpressionAST *TypeOfExpression::expressionAST() const
     return extractExpressionAST(m_lookupContext.expressionDocument());
 }
 
-ExpressionAST *TypeOfExpression::extractExpressionAST(Document::Ptr doc) const
-{
-    if (! doc->translationUnit()->ast())
-        return 0;
-
-    return doc->translationUnit()->ast()->asExpression();
-}
-
-Document::Ptr TypeOfExpression::documentForExpression(const QByteArray &utf8code) const
-{
-    // create the expression's AST.
-    Document::Ptr doc = Document::create(QLatin1String("<completion>"));
-    doc->setUtf8Source(utf8code);
-    doc->parse(Document::ParseExpression);
-    return doc;
-}
-
 void TypeOfExpression::processEnvironment(Document::Ptr doc, Environment *env,
                                           QSet<QString> *processed) const
 {
@@ -210,3 +193,24 @@ QByteArray TypeOfExpression::preprocessedExpression(const QByteArray &utf8code)
     Preprocessor preproc(0, m_environment.data());
     return preproc.run("<expression>", utf8code);
 }
+
+namespace CPlusPlus {
+
+ExpressionAST *extractExpressionAST(Document::Ptr doc)
+{
+    if (! doc->translationUnit()->ast())
+        return 0;
+
+    return doc->translationUnit()->ast()->asExpression();
+}
+
+Document::Ptr documentForExpression(const QByteArray &utf8code)
+{
+    // create the expression's AST.
+    Document::Ptr doc = Document::create(QLatin1String("<completion>"));
+    doc->setUtf8Source(utf8code);
+    doc->parse(Document::ParseExpression);
+    return doc;
+}
+
+} // namespace CPlusPlus

src/libs/cplusplus/TypeOfExpression.h

@@ -122,15 +122,13 @@ public:
     Scope *scope() const;
 
     ExpressionAST *expressionAST() const;
+    QByteArray preprocessedExpression(const QByteArray &utf8code) const;
 
 private:
-    ExpressionAST *extractExpressionAST(Document::Ptr doc) const;
-    Document::Ptr documentForExpression(const QByteArray &utf8code) const;
 
     void processEnvironment(Document::Ptr doc, Environment *env,
                             QSet<QString> *processed) const;
 
-    QByteArray preprocessedExpression(const QByteArray &utf8code) const;
 
 private:
     Document::Ptr m_thisDocument;
@@ -142,6 +140,9 @@ private:
     mutable QSharedPointer<Environment> m_environment;
 };
 
+ExpressionAST CPLUSPLUS_EXPORT *extractExpressionAST(Document::Ptr doc);
+Document::Ptr CPLUSPLUS_EXPORT documentForExpression(const QByteArray &utf8code);
+
 } // namespace CPlusPlus
 
 #endif // CPLUSPLUS_TYPEOFEXPRESSION_H