Fix C++ model crash when evaluating deep expressions

Task-number: QTCREATORBUG-3831
Done-with: Roberto Raggi

src/shared/cplusplus/Bind.cpp

@@ -66,6 +66,8 @@
 
 using namespace CPlusPlus;
 
+const int Bind::kMaxDepth(100);
+
 Bind::Bind(TranslationUnit *unit)
     : ASTVisitor(unit),
       _scope(0),
@@ -75,7 +77,8 @@ Bind::Bind(TranslationUnit *unit)
       _visibility(Symbol::Public),
       _objcVisibility(Symbol::Public),
       _methodKey(Function::NormalMethod),
-      _skipFunctionBodies(false)
+      _skipFunctionBodies(false),
+      _depth(0)
 {
 }
 
@@ -291,6 +294,19 @@ FullySpecifiedType Bind::postfixDeclarator(PostfixDeclaratorAST *ast, const Full
     return value;
 }
 
+bool Bind::preVisit(AST *)
+{
+    ++_depth;
+    if (_depth > kMaxDepth)
+        return false;
+    return true;
+}
+
+void Bind::postVisit(AST *)
+{
+    --_depth;
+}
+
 // AST
 bool Bind::visit(ObjCSelectorArgumentAST *ast)
 {

src/shared/cplusplus/Bind.h

@@ -138,6 +138,9 @@ protected:
     void lambdaDeclarator(LambdaDeclaratorAST *ast);
     FullySpecifiedType trailingReturnType(TrailingReturnTypeAST *ast, const FullySpecifiedType &init);
 
+    virtual bool preVisit(AST *);
+    virtual void postVisit(AST *);
+
     // AST
     virtual bool visit(ObjCSelectorArgumentAST *ast);
     virtual bool visit(AttributeAST *ast);
@@ -297,6 +300,8 @@ protected:
     virtual bool visit(ArrayDeclaratorAST *ast);
 
 private:
+    static const int kMaxDepth;
+
     Scope *_scope;
     ExpressionTy _expression;
     const Name *_name;
@@ -306,6 +311,7 @@ private:
     int _objcVisibility;
     int _methodKey;
     bool _skipFunctionBodies;
+    int _depth;
 };
 
 } // namespace CPlusPlus