#6298 stack overflow in Scope::findFunctionInBase (endless recursion). Fix handling of circular class hierarchy

lib/symboldatabase.cpp

@@ -844,8 +844,16 @@ SymbolDatabase::SymbolDatabase(const Tokenizer *tokenizer, const Settings *setti
         // fill in base class info
         for (std::list<Type>::iterator it = typeList.begin(); it != typeList.end(); ++it) {
             // finish filling in base class info
-            for (unsigned int i = 0; i < it->derivedFrom.size(); ++i)
-                it->derivedFrom[i].type = findType(it->derivedFrom[i].nameTok, it->enclosingScope);
+            for (unsigned int i = 0; i < it->derivedFrom.size(); ++i) {
+				const Type* found = findType(it->derivedFrom[i].nameTok, it->enclosingScope);
+				if (found && found->findDependency(&(*it))) {
+						// circular dependency
+						//_tokenizer->syntaxError(nullptr);
+				}
+				else {
+					it->derivedFrom[i].type = found;
+				}
+			}
         }
 
         // fill in friend info
@@ -2054,6 +2062,16 @@ bool Type::hasCircularDependencies(std::set<BaseInfo>* anchestors) const
     return false;
 }
 
+bool Type::findDependency(const Type* anchestor) const {
+	if (this==anchestor)
+		return true;
+	for (std::vector<BaseInfo>::const_iterator parent=derivedFrom.begin(); parent!=derivedFrom.end(); ++parent) {
+		if (parent->type && parent->type->findDependency(anchestor))
+			return true;
+	}
+	return false;
+}
+
 bool Variable::arrayDimensions(const Library* lib)
 {
     const Library::Container* container = lib->detectContainer(_start);

lib/symboldatabase.h

@@ -122,7 +122,14 @@ public:
     * @param anchestors list of anchestors. For internal usage only, clients should not supply this argument.
     * @return true if there is a circular dependency
     */
-    bool hasCircularDependencies(std::set<BaseInfo>* anchestors = 0) const;
+    bool hasCircularDependencies(std::set<BaseInfo>* anchestors = nullptr) const;
+
+	/**
+    * Check for dependency
+    * @param anchestor potential anchestor
+    * @return true if there is a dependency
+    */
+	bool findDependency(const Type* anchestor) const;
 };
 
 /** @brief Information about a member variable. */

test/testclass.cpp

@@ -4929,14 +4929,14 @@ private:
                    "int MixerParticipant::GetAudioFrame() {\n"
                    "    return 0;\n"
                    "}");
-        ASSERT_EQUALS("[test.cpp:4] -> [test.cpp:2]: (performance, inconclusive) Technically the member function 'MixerParticipant::GetAudioFrame' can be static.\n", errout.str());
+        ASSERT_EQUALS("", errout.str());
 
         checkConst("class MixerParticipant : public MixerParticipant {\n"
                    "    bool InitializeFileReader() {\n"
                    "       printf(\"music\");\n"
                    "    }\n"
                    "};");
-        ASSERT_EQUALS("[test.cpp:2]: (performance, inconclusive) Technically the member function 'MixerParticipant::InitializeFileReader' can be static.\n", errout.str());
+        ASSERT_EQUALS("", errout.str());
 
         // Based on an example from SVN source code causing an endless recursion within CheckClass::isConstMemberFunc()
         // A more complete example including a template declaration like

test/testsymboldatabase.cpp

@@ -260,6 +260,7 @@ private:
         TEST_CASE(functionPrototype); // ticket #5867
 
         TEST_CASE(lambda); // ticket #5867
+		TEST_CASE(circularDependencies); // 6298
     }
 
     void array() const {
@@ -2914,6 +2915,21 @@ private:
             ASSERT_EQUALS(Scope::eLambda, scope->type);
         }
     }
+	// #6298 "stack overflow in Scope::findFunctionInBase (endless recursion)"
+	void circularDependencies() {
+		check("template<template<class> class E,class D> class C : E<D> {\n"
+					"	public:\n"
+					"		int f();\n"
+					"};\n"
+					"class E : C<D,int> {\n"
+					"	public:\n"
+					"		int f() { return C< ::D,int>::f(); }\n"
+					"};\n"
+					"int main() {\n"
+					"	E c;\n"
+					"	c.f();\n"
+					"}");
+	}
 };
 
 REGISTER_TEST(TestSymbolDatabase)

test/testunusedprivfunc.cpp

@@ -722,7 +722,7 @@ private:
               "    C a;\n"
               "}");
 
-        ASSERT_EQUALS("[test.cpp:10]: (style) Unused private function: 'InfiniteA::foo'\n", errout.str());
+        ASSERT_EQUALS("", errout.str());
     }
 
     void staticVariable() {