Refactorized CheckObsoleteFunctions:

- Speedup checkobsoletefunctions by using symboldatabase and by not calling SymbolDatabase::findFunctionByToken() for each function call.
-> Benchmark (SQlite amalgamation):
    CheckObsoleteFunctions::runSimplifiedChecks(): 9s -> 0,016s (562%, 4% on entire runtime)
- Fixed false negative when passing function result as parameter

lib/checkobsoletefunctions.cpp

@@ -38,42 +38,38 @@ void CheckObsoleteFunctions::obsoleteFunctions()
 
     const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
 
-    for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) {
+    // Functions defined somewhere?
+    for (unsigned int i = 0; i < symbolDatabase->functionScopes.size(); i++) {
+        const Scope* scope = symbolDatabase->functionScopes[i];
+        _obsoleteStandardFunctions.erase(scope->className);
+        _obsoletePosixFunctions.erase(scope->className);
+        _obsoleteC99Functions.erase(scope->className);
+    }
 
+    for (unsigned int i = 0; i < symbolDatabase->functionScopes.size(); i++) {
+        const Scope* scope = symbolDatabase->functionScopes[i];
+        for (const Token* tok = scope->classStart; tok != scope->classEnd; tok = tok->next()) {
             if (tok->isName() && tok->varId()==0 && (tok->next() && tok->next()->str() == "(") &&
-            (!Token::Match(tok->previous(), ".|::|:|,") || Token::simpleMatch(tok->tokAt(-2), "std :: gets"))) {
+                (!Token::Match(tok->previous(), ".|::") || Token::simpleMatch(tok->tokAt(-2), "std ::"))) {
-            // c function declaration?
-            if ((tok->next()->link()->next() && tok->next()->link()->next()->str() == ";") && (tok->previous() && (tok->previous()->str() == "*" || tok->previous()->isName()))) {
-                continue;
-            }
-
-            // function declaration?
-            const Function * function = symbolDatabase->findFunctionByToken(tok);
-            if (function && function->hasBody) {
-                _obsoleteStandardFunctions.erase(tok->str());
-                _obsoletePosixFunctions.erase(tok->str());
-                continue;
-            }
 
                 std::map<std::string,std::string>::const_iterator it = _obsoleteStandardFunctions.find(tok->str());
                 if (it != _obsoleteStandardFunctions.end()) {
                     // If checking an old code base it might be uninteresting to update obsolete functions.
-                // Therefore this is "information"
+                    reportError(tok, Severity::style, "obsoleteFunctions"+it->first, it->second);
-                reportError(tok->next(), Severity::style, "obsoleteFunctions"+it->first, it->second);
                 } else {
                     if (_settings->standards.posix) {
                         it = _obsoletePosixFunctions.find(tok->str());
                         if (it != _obsoletePosixFunctions.end()) {
                             // If checking an old code base it might be uninteresting to update obsolete functions.
-                        // Therefore this is "information"
+                            reportError(tok, Severity::style, "obsoleteFunctions"+it->first, it->second);
-                        reportError(tok->next(), Severity::style, "obsoleteFunctions"+it->first, it->second);
                         }
                     }
                     if (_settings->standards.c >= Standards::C99) {
                         // alloca : this function is obsolete in C but not in C++ (#4382)
                         it = _obsoleteC99Functions.find(tok->str());
                         if (it != _obsoleteC99Functions.end() && !(tok->str() == "alloca" && _tokenizer->isCPP())) {
-                        reportError(tok->next(), Severity::style, "obsoleteFunctions"+it->first, it->second);
+                            reportError(tok, Severity::style, "obsoleteFunctions"+it->first, it->second);
+                        }
                     }
                 }
             }

test/testobsoletefunctions.cpp

@@ -214,6 +214,12 @@ private:
               "    char *x = gets();\n"
               "}\n");
         ASSERT_EQUALS("[test.cpp:3]: (style) Obsolete function 'gets' called. It is recommended to use the function 'fgets' instead.\n", errout.str());
+
+        check("void f()\n"
+              "{\n"
+              "    foo(x, gets());\n"
+              "}");
+        ASSERT_EQUALS("[test.cpp:3]: (style) Obsolete function 'gets' called. It is recommended to use the function 'fgets' instead.\n", errout.str());
     }
 
     void testalloca() {