Fix #10737 Regression: unusedStructMember (#3894)

* Fix #10737 Regression: unusedStructMember

* Add test for #9161

* simpleMatch

lib/symboldatabase.cpp

@@ -106,16 +106,15 @@ static bool isExecutableScope(const Token* tok)
     const Token * tok2 = tok->link()->previous();
     if (Token::simpleMatch(tok2, "; }"))
         return true;
-    if (Token::Match(tok2, "{|} }")) {
+    if (tok2 == tok)
-        const Token* startTok = tok2->str() == "{" ? tok2 : tok2->link();
+        return false;
+    if (Token::simpleMatch(tok2, "} }")) { // inner scope
+        const Token* startTok = tok2->link();
         if (Token::Match(startTok->previous(), "do|try|else {"))
             return true;
-        if (Token::simpleMatch(startTok->previous(), ") {"))
+        if (Token::Match(startTok->previous(), ")|] {"))
             return !findLambdaStartToken(tok2);
-        if (tok->str() == "{")
+        return isExecutableScope(startTok);
-            return false;
-        else
-            return isExecutableScope(startTok);
     }
     return false;
 }
@@ -128,7 +127,7 @@ void SymbolDatabase::createSymbolDatabaseFindAllScopes()
     // pointer to current scope
     Scope *scope = &scopeList.back();
 
-    // Store the edning of init lists
+    // Store the ending of init lists
     std::stack<std::pair<const Token*, const Scope*>> endInitList;
     auto inInitList = [&] {
         if (endInitList.empty())

test/teststl.cpp

@@ -3904,6 +3904,14 @@ private:
               "    f(p.c_str());\n"
               "}\n");
         ASSERT_EQUALS("", errout.str());
+
+        check("struct S {\n" //#9161
+              "    const char* f() const noexcept {\n"
+              "        return (\"\" + m).c_str();\n"
+              "    }\n"
+              "    std::string m;\n"
+              "};\n", /*inconclusive*/ true);
+        ASSERT_EQUALS("[test.cpp:3]: (error) Dangerous usage of c_str(). The value returned by c_str() is invalid after this call.\n", errout.str());
     }
 
     void uselessCalls() {

test/testunusedvar.cpp

@@ -67,6 +67,7 @@ private:
         TEST_CASE(structmember17); // #10591
         TEST_CASE(structmember18); // #10684
         TEST_CASE(structmember19); // #10826, #10848, #10852
+        TEST_CASE(structmember20); // #10737
 
         TEST_CASE(localvar1);
         TEST_CASE(localvar2);
@@ -1743,6 +1744,21 @@ private:
         settings.enforcedLang = Settings::None;
     }
 
+    void structmember20() { // #10737
+        checkStructMemberUsage("void f() {\n"
+                               "    {\n"
+                               "    }\n"
+                               "    {\n"
+                               "        struct S { int a; };\n"
+                               "        S s{};\n"
+                               "        {\n"
+                               "            if (s.a) {}\n"
+                               "        }\n"
+                               "    }\n"
+                               "}\n");
+        ASSERT_EQUALS("", errout.str());
+    }
+
     void functionVariableUsage_(const char* file, int line, const char code[], const char filename[] = "test.cpp") {
         // Clear the error buffer..
         errout.str("");