Fix #14161 FN constVariablePointer (assignment to const pointer)

Author: web-flow

lib/astutils.cpp

@@ -2916,7 +2916,10 @@ static bool isExpressionChangedAt(const F& getExprTok,
             aliased = isAliasOf(tok, expr, &i);
         if (!aliased)
             return false;
-        if (isVariableChanged(tok, indirect + i, settings, depth))
+        i += indirect;
+        if (tok->valueType() && tok->valueType()->pointer)
+            i = std::min(i, tok->valueType()->pointer);
+        if (isVariableChanged(tok, i, settings, depth))
             return true;
         // TODO: Try to traverse the lambda function
         if (Token::Match(tok, "%var% ("))

lib/checkother.cpp

@@ -1916,8 +1916,13 @@ void CheckOther::checkConstPointer()
                 continue;
             if (Token::simpleMatch(parent, "(") && Token::Match(parent->astOperand1(), "if|while"))
                 continue;
-            if (Token::simpleMatch(parent, "=") && parent->astOperand1() == tok)
-                continue;
+            if (Token::simpleMatch(parent, "=")) {
+                const Token* lhs = parent->astOperand1();
+                if (lhs == tok)
+                    continue;
+                if (lhs && lhs->valueType() && lhs->valueType()->isConst(vt->pointer))
+                    continue;
+            }
             if (const Token* ftok = getTokenArgumentFunction(tok, argn)) {
                 if (ftok->function()) {
                     const bool isCastArg = parent->isCast() && !ftok->function()->getOverloadedFunctions().empty(); // assume that cast changes the called function

test/testother.cpp

@@ -4497,6 +4497,16 @@ class TestOther : public TestFixture {
         ASSERT_EQUALS("[test.cpp:2:18]: (style) Parameter 's' can be declared as pointer to const [constParameterPointer]\n"
                       "[test.cpp:5:18]: (style) Parameter 's' can be declared as pointer to const [constParameterPointer]\n",
                       errout_str());
+
+        check("struct T;\n"
+              "void use(const T*);\n"
+              "void f(T* tok0) {\n"
+              "    T *tok1 = tok0;\n"
+              "    const T *tok2 = tok1;\n"
+              "    use(tok2);\n"
+              "}\n");
+        ASSERT_EQUALS("[test.cpp:4:8]: (style) Variable 'tok1' can be declared as pointer to const [constVariablePointer]\n",
+                      errout_str());
     }
 
     void constArray() {