Fix #13303 FN unreadVariable (iterator) (#8023)

Author: chrchr-github

lib/astutils.cpp

@@ -3678,15 +3678,15 @@ bool isGlobalData(const Token *expr)
             // TODO check if pointer points at local data
             const Variable *lhsvar = tok->astOperand1()->variable();
             const ValueType *lhstype = tok->astOperand1()->valueType();
-            if (lhsvar->isPointer()) {
+            if (lhsvar->isPointer() || !lhstype || lhstype->type == ValueType::Type::ITERATOR) {
                 globalData = true;
                 return ChildrenToVisit::none;
             }
             if (lhsvar->isArgument() && lhsvar->isArray()) {
                 globalData = true;
                 return ChildrenToVisit::none;
             }
-            if (lhsvar->isArgument() && (!lhstype || (lhstype->type <= ValueType::Type::VOID && !lhstype->container))) {
+            if (lhsvar->isArgument() && lhstype->type <= ValueType::Type::VOID && !lhstype->container) {
                 globalData = true;
                 return ChildrenToVisit::none;
             }

lib/checkunusedvar.cpp

@@ -1283,12 +1283,6 @@ void CheckUnusedVar::checkFunctionVariableUsage()
             if (!tok->astOperand1())
                 continue;
 
-            const Token *iteratorToken = tok->astOperand1();
-            while (Token::Match(iteratorToken, "[.*]"))
-                iteratorToken = iteratorToken->astOperand1();
-            if (iteratorToken && iteratorToken->variable() && iteratorToken->variable()->typeEndToken()->str().find("iterator") != std::string::npos)
-                continue;
-
             const Token *op1tok = tok->astOperand1();
             while (Token::Match(op1tok, ".|[|*"))
                 op1tok = op1tok->astOperand1();

test/testunusedvar.cpp

@@ -5228,6 +5228,13 @@ class TestUnusedVar : public TestFixture {
                               "    }\n"
                               "}");
         ASSERT_EQUALS("", errout_str());
+
+        functionVariableUsage("void f(const std::vector<int>& v) {\n" // #13303
+                              "    std::vector<int>::const_iterator it = v.cbegin();\n"
+                              "    if (*it == 0)\n"
+                              "        it = v.cend();\n"
+                              "}\n");
+        ASSERT_EQUALS("[test.cpp:4:12]: (style) Variable 'it' is assigned a value that is never used. [unreadVariable]\n", errout_str());
     }
 
     void localvaralias19() { // #9828