Fix #11473 FP constVariable / #11448 FP constParameter / #11188 FP danglingTempReference (#4680)

* Fix #11473 FP constVariable with range-based for / #11448 FP constParameter with unused non-const range loop variable

* Fix ValueType / #11188 FP danglingTempReference with auto

* Fix ValueType in range-based for

* Update symboldatabase.cpp

lib/checkother.cpp

@@ -1464,6 +1464,13 @@ void CheckOther::checkConstVariable()
                         break;
                     }
                 }
+                if (astIsRangeBasedForDecl(tok) && Token::Match(tok->astParent()->astOperand2(), "%varid%", var->declarationId())) {
+                    const Variable* refvar = tok->astParent()->astOperand1()->variable();
+                    if (refvar && refvar->isReference() && !refvar->isConst()) {
+                        usedInAssignment = true;
+                        break;
+                    }
+                }
             }
             if (usedInAssignment)
                 continue;

lib/symboldatabase.cpp

@@ -6132,7 +6132,7 @@ void SymbolDatabase::setValueType(Token* tok, const ValueType& valuetype, Source
                 if (autoTok->strAt(1) == "*" && vt.pointer)
                     vt.pointer--;
                 if (Token::Match(autoTok->tokAt(-1), "const|constexpr"))
-                    vt.constness |= 1;
+                    vt.constness |= (1 << vt.pointer);
                 setValueType(autoTok, vt);
                 setAutoTokenProperties(autoTok);
                 if (vt2->pointer > vt.pointer)
@@ -6338,8 +6338,10 @@ void SymbolDatabase::setValueType(Token* tok, const ValueType& valuetype, Source
                 setValueType(autoToken, autovt);
                 setAutoTokenProperties(autoToken);
                 ValueType varvt(autovt);
+                if (autoToken->strAt(1) == "*" && autovt.pointer)
+                    autovt.pointer--;
                 if (isconst)
-                    varvt.constness |= 1;
+                    varvt.constness |= (1 << autovt.pointer);
                 setValueType(parent->previous(), varvt);
                 Variable * var = const_cast<Variable *>(parent->previous()->variable());
                 if (var) {

test/testautovariables.cpp

@@ -2022,6 +2022,13 @@ private:
               "  const int& x = (*e)[1];\n"
               "}\n");
         ASSERT_EQUALS("", errout.str());
+
+        check("int* g();\n" // #11188
+              "void f() {\n"
+              "    const auto& p = g();\n"
+              "    if (p != nullptr) {}\n"
+              "}\n");
+        ASSERT_EQUALS("", errout.str());
     }
 
     void testglobalnamespace() {

test/testother.cpp

@@ -2349,8 +2349,7 @@ private:
         check("void f(std::vector<int>& v) {\n"
               "    for(auto& x:v) {}\n"
               "}");
-        ASSERT_EQUALS("[test.cpp:1]: (style) Parameter 'v' can be declared as reference to const\n"
+        ASSERT_EQUALS("[test.cpp:2]: (style) Variable 'x' can be declared as reference to const\n",
-                      "[test.cpp:2]: (style) Variable 'x' can be declared as reference to const\n",
                       errout.str());
 
         check("void f(std::vector<int>& v) {\n" // #10980
@@ -3019,6 +3018,16 @@ private:
               "    std::cout << m[0] << std::endl;\n"
               "};\n");
         ASSERT_EQUALS("", errout.str());
+
+        check("struct S { int i; };\n" // #11473
+              "void f(std::vector<std::vector<S>>&m, int*& p) {\n"
+              "    auto& a = m[0];\n"
+              "    for (auto& s : a) {\n"
+              "        p = &s.i;\n"
+              "        return;\n"
+              "    }\n"
+              "}\n");
+        ASSERT_EQUALS("", errout.str());
     }
 
     void constParameterCallback() {

test/testsymboldatabase.cpp

@@ -500,6 +500,7 @@ private:
         TEST_CASE(auto15); // C++17 auto deduction from braced-init-list
         TEST_CASE(auto16);
         TEST_CASE(auto17); // #11163
+        TEST_CASE(auto18);
 
         TEST_CASE(unionWithConstructor);
 
@@ -8469,14 +8470,14 @@ private:
         autotok = Token::findsimplematch(autotok, "auto v4");
         ASSERT(autotok);
         ASSERT(autotok->valueType());
-        TODO_ASSERT_EQUALS(0, 1, autotok->valueType()->constness);
+        ASSERT_EQUALS(3, autotok->valueType()->constness);
         ASSERT_EQUALS(1, autotok->valueType()->pointer);
         ASSERT_EQUALS(ValueType::SIGNED, autotok->valueType()->sign);
         ASSERT_EQUALS(ValueType::INT, autotok->valueType()->type);
         vartok = Token::findsimplematch(autotok, "v4 =");
         ASSERT(autotok);
         ASSERT(autotok->valueType());
-        ASSERT_EQUALS(1, vartok->valueType()->constness);
+        ASSERT_EQUALS(3, vartok->valueType()->constness);
         ASSERT_EQUALS(1, vartok->valueType()->pointer);
         ASSERT_EQUALS(ValueType::SIGNED, vartok->valueType()->sign);
         ASSERT_EQUALS(ValueType::INT, vartok->valueType()->type);
@@ -8549,14 +8550,14 @@ private:
         autotok = Token::findsimplematch(autotok, "auto v9");
         ASSERT(autotok);
         ASSERT(autotok->valueType());
-        TODO_ASSERT_EQUALS(0, 1, autotok->valueType()->constness);
+        ASSERT_EQUALS(3, autotok->valueType()->constness);
         ASSERT_EQUALS(1, autotok->valueType()->pointer);
         ASSERT_EQUALS(ValueType::SIGNED, autotok->valueType()->sign);
         ASSERT_EQUALS(ValueType::INT, autotok->valueType()->type);
         vartok = Token::findsimplematch(autotok, "v9 =");
         ASSERT(autotok);
         ASSERT(autotok->valueType());
-        ASSERT_EQUALS(1, vartok->valueType()->constness);
+        ASSERT_EQUALS(3, vartok->valueType()->constness);
         ASSERT_EQUALS(1, vartok->valueType()->pointer);
         ASSERT_EQUALS(ValueType::SIGNED, vartok->valueType()->sign);
         ASSERT_EQUALS(ValueType::INT, vartok->valueType()->type);
@@ -8750,6 +8751,34 @@ private:
         ASSERT_EQUALS(5, db->variableList().size());
     }
 
+    void auto18() {
+        GET_SYMBOL_DB("void f(const int* p) {\n"
+                      "    const int* const& r = p;\n"
+                      "    const auto& s = p;\n"
+                      "}\n");
+        ASSERT_EQUALS(4, db->variableList().size());
+
+        const Variable* r = db->variableList()[2];
+        ASSERT(r->isReference());
+        ASSERT(r->isConst());
+        ASSERT(r->isPointer());
+        const Token* varTok = Token::findsimplematch(tokenizer.tokens(), "r");
+        ASSERT(varTok && varTok->valueType());
+        ASSERT_EQUALS(varTok->valueType()->constness, 3);
+        ASSERT_EQUALS(varTok->valueType()->pointer, 1);
+        ASSERT(varTok->valueType()->reference == Reference::LValue);
+
+        const Variable* s = db->variableList()[3];
+        ASSERT(s->isReference());
+        ASSERT(s->isConst());
+        ASSERT(s->isPointer());
+        const Token* autoTok = Token::findsimplematch(tokenizer.tokens(), "auto");
+        ASSERT(autoTok && autoTok->valueType());
+        ASSERT_EQUALS(autoTok->valueType()->constness, 3);
+        ASSERT_EQUALS(autoTok->valueType()->pointer, 1);
+        TODO_ASSERT(autoTok->valueType()->reference == Reference::LValue);
+    }
+
     void unionWithConstructor() {
         GET_SYMBOL_DB("union Fred {\n"
                       "    Fred(int x) : i(x) { }\n"