Fixed #4231 (False positive: (error) Returning/dereferencing 'ptr' after it is deallocated / released (ignoring goto))

lib/checkleakautovar.cpp

@@ -467,6 +467,11 @@ void CheckLeakAutoVar::checkScope(const Token * const startToken,
             varInfo->clear();
         }
 
+        // goto => weird execution path
+        else if (tok->str() == "goto") {
+            varInfo->clear();
+        }
+
         // throw
         // TODO: if the execution leave the function then treat it as return
         else if (tok->str() == "throw") {

test/testleakautovar.cpp

@@ -61,6 +61,7 @@ private:
 
         // goto
         TEST_CASE(goto1);
+        TEST_CASE(goto2);
 
         // if/else
         TEST_CASE(ifelse1);
@@ -324,6 +325,19 @@ private:
         ASSERT_EQUALS("", errout.str());
     }
 
+    void goto2() { // #4231
+        check("static char * f() {\n"
+              "x:\n"
+              "    char *p = malloc(100);\n"
+              "    if (err) {\n"
+              "        free(p);\n"
+              "        goto x;\n"
+              "    }\n"
+              "    return p;\n"  // no error since there is a goto
+              "}");
+        ASSERT_EQUALS("", errout.str());
+    }
+
     void ifelse1() {
         check("int f() {\n"
               "    char *p = NULL;\n"