Fixed #9821 (False positive: Delegating constructor and initialization list)

lib/checkclass.cpp

@@ -943,9 +943,15 @@ void CheckClass::initializationListUsage()
 
     for (const Scope *scope : mSymbolDatabase->functionScopes) {
         // Check every constructor
-        if (!scope->function || (!scope->function->isConstructor()))
+        if (!scope->function || !scope->function->isConstructor())
             continue;
 
+        // Do not warn when a delegate constructor is called
+        if (const Token *initList = scope->function->constructorMemberInitialization()) {
+            if (Token::Match(initList, ": %name% {|(") && initList->strAt(1) == scope->className)
+                continue;
+        }
+
         const Scope* owner = scope->functionOf;
         for (const Token* tok = scope->bodyStart; tok != scope->bodyEnd; tok = tok->next()) {
             if (Token::Match(tok, "%name% (")) // Assignments might depend on this function call or if/for/while/switch statement from now on.

test/testclass.cpp

@@ -6567,6 +6567,19 @@ private:
                                      "    Foo m_i;\n"
                                      "};");
         ASSERT_EQUALS("", errout.str());
+
+        checkInitializationListUsage("class A {\n" // #9821 - delegate constructor
+                                     "public:\n"
+                                     "    A() : st{} {}\n"
+                                     "\n"
+                                     "    explicit A(const std::string &input): A() {\n"
+                                     "        st = input;\n"
+                                     "    }\n"
+                                     "\n"
+                                     "private:\n"
+                                     "    std::string st;\n"
+                                     "};");
+        ASSERT_EQUALS("", errout.str());
     }