Fixed #11102 (False positive: unreadVariable when union in derived struct is used)

Author: danmar

lib/symboldatabase.cpp

@@ -1002,24 +1002,24 @@ void SymbolDatabase::createSymbolDatabaseVariableSymbolTable()
     }
 
     // fill in missing variables if possible
-    const std::size_t functions = functionScopes.size();
-    for (std::size_t i = 0; i < functions; ++i) {
-        const Scope *func = functionScopes[i];
+    for (const Scope *func: functionScopes) {
         for (const Token *tok = func->bodyStart->next(); tok && tok != func->bodyEnd; tok = tok->next()) {
             // check for member variable
-            if (tok->varId() && tok->next() &&
-                (tok->next()->str() == "." ||
-                 (tok->next()->str() == "[" && tok->linkAt(1)->strAt(1) == "."))) {
-                const Token *tok1 = tok->next()->str() == "." ? tok->tokAt(2) : tok->linkAt(1)->tokAt(2);
-                if (tok1 && tok1->varId() && mVariableList[tok1->varId()] == nullptr) {
-                    const Variable *var = mVariableList[tok->varId()];
-                    if (var && var->typeScope()) {
-                        // find the member variable of this variable
-                        const Variable *var1 = var->typeScope()->getVariable(tok1->str());
-                        if (var1) {
-                            // add this variable to the look up table
-                            mVariableList[tok1->varId()] = var1;
-                        }
+            if (!Token::Match(tok, "%var% .|["))
+                continue;
+            const Token* tokDot = tok->next();
+            while (Token::simpleMatch(tokDot, "["))
+                tokDot = tokDot->link()->next();
+            if (!Token::Match(tokDot, ". %var%"))
+                continue;
+            const Token *member = tokDot->next();
+            if (mVariableList[member->varId()] == nullptr) {
+                const Variable *var1 = mVariableList[tok->varId()];
+                if (var1 && var1->typeScope()) {
+                    const Variable* memberVar = var1->typeScope()->getVariable(member->str());
+                    if (memberVar) {
+                        // add this variable to the look up table
+                        mVariableList[member->varId()] = memberVar;
                     }
                 }
             }
@@ -4442,7 +4442,6 @@ void Scope::getVariableList(const Settings* settings, const Token* start, const
 
         // Is it a function?
         else if (tok->str() == "{") {
-
             tok = tok->link();
             continue;
         }
@@ -4614,13 +4613,18 @@ const Token *Scope::checkVariable(const Token *tok, AccessControl varaccess, con
 
 const Variable *Scope::getVariable(const std::string &varname) const
 {
-    std::list<Variable>::const_iterator iter;
-
-    for (iter = varlist.begin(); iter != varlist.end(); ++iter) {
-        if (iter->name() == varname)
-            return &*iter;
+    for (const Variable& var: varlist) {
+        if (var.name() == varname)
+            return &var;
+    }
+    if (definedType) {
+        for (const Type::BaseInfo& baseInfo: definedType->derivedFrom) {
+            if (baseInfo.type && baseInfo.type->classScope) {
+                if (const Variable* var = baseInfo.type->classScope->getVariable(varname))
+                    return var;
+            }
+        }
     }
-
     return nullptr;
 }
 

test/testimportproject.cpp

@@ -352,7 +352,7 @@ class TestImportProject : public TestFixture {
         ASSERT_EQUALS("lib/", s.includePaths.front());
     }
 
-    void ignorePaths() {
+    void ignorePaths() const {
         ImportProject::FileSettings fs1, fs2;
         fs1.filename = "foo/bar";
         fs2.filename = "qwe/rty";

test/testsymboldatabase.cpp

@@ -184,6 +184,7 @@ class TestSymbolDatabase : public TestFixture {
 
         TEST_CASE(rangeBasedFor);
 
+        TEST_CASE(memberVar1);
         TEST_CASE(arrayMemberVar1);
         TEST_CASE(arrayMemberVar2);
         TEST_CASE(arrayMemberVar3);
@@ -1417,6 +1418,22 @@ class TestSymbolDatabase : public TestFixture {
         ASSERT_EQUALS("signed int *", c->valueType()->str());
     }
 
+    void memberVar1() {
+        GET_SYMBOL_DB("struct Foo {\n"
+                      "    int x;\n"
+                      "};\n"
+                      "struct Bar : public Foo {};\n"
+                      "void f() {\n"
+                      "    struct Bar bar;\n"
+                      "    bar.x = 123;\n"  // <- x should get a variable() pointer
+                      "}");
+
+        ASSERT(db != nullptr);
+        const Token *tok = Token::findsimplematch(tokenizer.tokens(), "x =");
+        ASSERT(tok->variable());
+        ASSERT(Token::simpleMatch(tok->variable()->typeStartToken(), "int x ;"));
+    }
+
     void arrayMemberVar1() {
         GET_SYMBOL_DB("struct Foo {\n"
                       "    int x;\n"