Fix #7731 FN postfixOperator for variable declared in for-loop init statement

lib/checkpostfixoperator.cpp

@@ -64,7 +64,19 @@ void CheckPostfixOperator::postfixOperator()
                 if (var->isPointer() || var->isArray())
                     continue;
 
-                if (Token::Match(var->nameToken()->previous(), "iterator|const_iterator|reverse_iterator|const_reverse_iterator")) {
+                const Token* typeEndTok = var->typeStartToken();
+                if (Token::simpleMatch(typeEndTok, "::"))
+                    typeEndTok = typeEndTok->next();
+                while (Token::Match(typeEndTok, "%name% ::|<")) {
+                    if (typeEndTok->linkAt(1)) {
+                        typeEndTok = typeEndTok->linkAt(1)->next();
+                        if (Token::simpleMatch(typeEndTok, "::"))
+                            typeEndTok = typeEndTok->next();
+                    }
+                    else
+                        typeEndTok = typeEndTok->tokAt(2);
+                }
+                if (Token::Match(typeEndTok, "iterator|const_iterator|reverse_iterator|const_reverse_iterator")) {
                     // the variable is an iterator
                     postfixOperatorError(tok);
                 } else if (var->type()) {

lib/symboldatabase.cpp

@@ -4969,6 +4969,7 @@ const Token *Scope::checkVariable(const Token *tok, AccessControl varaccess, con
     const Token *typetok = nullptr;
 
     if (tok && isVariableDeclaration(tok, vartok, typetok)) {
+        const Token* const orig = tok;
         // If the vartok was set in the if-blocks above, create a entry for this variable..
         tok = vartok->next();
         while (Token::Match(tok, "[|{"))
@@ -4993,6 +4994,17 @@ const Token *Scope::checkVariable(const Token *tok, AccessControl varaccess, con
             typestart = typestart->next();
 
         addVariable(vartok, typestart, vartok->previous(), varaccess, vType, this, settings);
+
+        if (type == eFor && orig->strAt(-2) == "for") {
+            for (const Token* tok2 = tok; tok2 && !Token::Match(tok2, "[;:]"); tok2 = tok2->next()) {
+                if (tok2->link()) {
+                    tok2 = tok2->link();
+                    continue;
+                }
+                if (Token::Match(tok2, ", %name%"))
+                    addVariable(tok2->next(), typestart, vartok->previous(), varaccess, vType, this, settings);
+            }
+        }
     }
 
     return tok;

test/testpostfixoperator.cpp

@@ -231,7 +231,10 @@ class TestPostfixOperator : public TestFixture {
               "}");
         ASSERT_EQUALS("", errout_str());
 
-
+        check("void f(const std::string &s) {\n" // #7731
+              "    for (std::string::const_iterator i = s.begin(), r = s.end() - 1; i != r; r--) {}\n"
+              "}\n");
+        ASSERT_EQUALS("[test.cpp:2]: (performance) Prefer prefix ++/-- operators for non-primitive types.\n", errout_str());
     }
 
     void testvolatile() {

test/testsymboldatabase.cpp

@@ -435,6 +435,7 @@ class TestSymbolDatabase : public TestFixture {
         TEST_CASE(createSymbolDatabaseFindAllScopes7);
         TEST_CASE(createSymbolDatabaseFindAllScopes8); // #12761
         TEST_CASE(createSymbolDatabaseFindAllScopes9);
+        TEST_CASE(createSymbolDatabaseFindAllScopes10);
 
         TEST_CASE(createSymbolDatabaseIncompleteVars);
 
@@ -5980,6 +5981,21 @@ class TestSymbolDatabase : public TestFixture {
         ASSERT_EQUALS(db->scopeList.back().type, Scope::eLambda);
     }
 
+    void createSymbolDatabaseFindAllScopes10() {
+        GET_SYMBOL_DB("void g() {\n"
+                      "    for (int i = 0, r = 1; i < r; ++i) {}\n"
+                      "}\n");
+        ASSERT(db);
+        ASSERT_EQUALS(3, db->scopeList.size());
+        ASSERT_EQUALS(2, db->scopeList.back().varlist.size());
+        const Token* const iTok = Token::findsimplematch(tokenizer.tokens(), "i");
+        const Token* const rTok = Token::findsimplematch(iTok, "r");
+        const Variable* i = iTok->variable(), *r = rTok->variable();
+        ASSERT(i != nullptr && r != nullptr);
+        ASSERT_EQUALS(i->typeStartToken(), r->typeStartToken());
+        ASSERT(i->valueType()->isTypeEqual(r->valueType()));
+    }
+
     void createSymbolDatabaseIncompleteVars()
     {
         {