Fixed #8360 (false positive "Ineffective call of function 'empty()'")

lib/checkstl.cpp

@@ -1429,6 +1429,7 @@ void CheckStl::uselessCalls()
                 } else if (Token::simpleMatch(tok->linkAt(3)->tokAt(-2), ", 0 )"))
                     uselessCallsSubstrError(tok, true);
             } else if (printWarning && Token::Match(tok, "[{};] %var% . empty ( ) ;") &&
+                       !tok->tokAt(4)->astParent() &&
                        tok->next()->variable() && tok->next()->variable()->isStlType(stl_containers_with_empty_and_clear))
                 uselessCallsEmptyError(tok->next());
             else if (Token::Match(tok, "[{};] std :: remove|remove_if|unique (") && tok->tokAt(5)->nextArgument())

test/teststl.cpp

@@ -2766,6 +2766,12 @@ private:
               "    return x ? true : (y.empty());\n"
               "}");
         ASSERT_EQUALS("", errout.str());
+
+        // #8360
+        check("void f(std::string s) {\n"
+              "    for (;s.empty();) {}\n"
+              "}");
+        ASSERT_EQUALS("", errout.str());
     }
 
     void stabilityOfChecks() {