Unused value: Fix false positive (ast, {})

lib/astutils.cpp

@@ -1084,17 +1084,15 @@ struct FwdAnalysis::Result FwdAnalysis::checkRecursive(const Token *expr, const
         if (Token::Match(tok, "return|throw")) {
             // TODO: Handle these better
             // Is expr variable used in expression?
-            bool read = false;
+            const Token *end = tok->findExpressionStartEndTokens().second->next();
-            visitAstNodes(tok->astOperand1(),
+            for (const Token *tok2 = tok; tok2 != end; tok2 = tok2->next()) {
-            [&](const Token *tok2) {
                 if (!local && Token::Match(tok2, "%name% ("))
-                    read = true;
+                    return Result(Result::Type::READ);
                 if (tok2->varId() && exprVarIds.find(tok2->varId()) != exprVarIds.end())
-                    read = true;
+                    return Result(Result::Type::READ);
-                return read ? ChildrenToVisit::done : ChildrenToVisit::op1_and_op2;
+            }
-            });
 
-            return Result(read ? Result::Type::READ : Result::Type::RETURN);
+            return Result(Result::Type::RETURN);
         }
 
         if (tok->str() == "}") {

lib/token.cpp

@@ -1215,6 +1215,8 @@ std::pair<const Token *, const Token *> Token::findExpressionStartEndTokens() co
 
     start = goToLeftParenthesis(start, end);
     end = goToRightParenthesis(start, end);
+    if (Token::simpleMatch(end, "{"))
+        end = end->link();
     return std::pair<const Token *, const Token *>(start,end);
 }
 

test/testtoken.cpp

@@ -939,6 +939,9 @@ private:
         givenACodeSampleToTokenize var2("typedef unsigned long long u64; void f() { *((u64 *)x) = 0; }");
         const Token *const tok2 = Token::findsimplematch(var2.tokens(), "*");
         ASSERT_EQUALS("*((unsigned long long*)x)", tok2->expressionString());
+
+        givenACodeSampleToTokenize data3("return (t){1,2};");
+        ASSERT_EQUALS("return(t){1,2}", data3.tokens()->expressionString());
     }
 };
 

test/testunusedvar.cpp

@@ -107,6 +107,7 @@ private:
         TEST_CASE(localvar51); // ticket #8128 - FN : tok = tok->next();
         TEST_CASE(localvar52);
         TEST_CASE(localvar53); // continue
+        TEST_CASE(localvar54); // ast, {}
         TEST_CASE(localvaralias1);
         TEST_CASE(localvaralias2); // ticket #1637
         TEST_CASE(localvaralias3); // ticket #1639
@@ -2109,6 +2110,14 @@ private:
         // TODO ASSERT_EQUALS("[test.cpp:5]: (style) Variable 'x' is assigned a value that is never used.\n", errout.str());
     }
 
+    void localvar54() {
+        functionVariableUsage("Padding fun() {\n"
+                              "  Distance d = DISTANCE;\n"
+                              "  return (Padding){ d, d, d, d };\n"
+                              "}\n");
+        ASSERT_EQUALS("", errout.str());
+    }
+
     void localvaralias1() {
         functionVariableUsage("void foo()\n"
                               "{\n"