Fixed #3987 (False positive: Memory leak reported when throwing/catching)

lib/checkleakautovar.cpp

@@ -462,10 +462,16 @@ void CheckLeakAutoVar::checkScope(const Token * const startToken,
         }
 
         // return
-        else if (tok->str() == "return" || tok->str() == "throw") {
+        else if (tok->str() == "return") {
             ret(tok, *varInfo);
             varInfo->clear();
         }
+
+        // throw
+        // TODO: if the execution leave the function then treat it as return
+        else if (tok->str() == "throw") {
+            varInfo->clear();
+        }
     }
 }
 

test/testleakautovar.cpp

@@ -90,6 +90,9 @@ private:
         TEST_CASE(test2);
         TEST_CASE(test3);  // #3954 - reference pointer
 
+        // Execution reaches a 'throw'
+        TEST_CASE(throw1);
+
         // Possible leak => Further configuration is needed for complete analysis
         TEST_CASE(configuration1);
         TEST_CASE(configuration2);
@@ -509,6 +512,24 @@ private:
         ASSERT_EQUALS("", errout.str());
     }
 
+    void throw1() { // 3987 - Execution reach a 'throw'
+        check("void f() {\n"
+              "    char *p = malloc(10);\n"
+              "    throw 123;\n"
+              "}");
+        TODO_ASSERT_EQUALS("error", "", errout.str());
+
+        check("void f() {\n"
+              "    char *p;\n"
+              "    try {\n"
+              "        p = malloc(10);\n"
+              "        throw 123;\n"
+              "    } catch (...) { }\n"
+              "    free(p);\n"
+              "}");
+        ASSERT_EQUALS("", errout.str());
+    }
+
     void configuration1() {
         // Possible leak => configuration is required for complete analysis
         // The user should be able to "white list" and "black list" functions.