# Use of stack memory after function return Detects when you access stack variable memory after its declaring function returns. ## Overview Use this check to detect access to a stack variable that a function declares after that function returns. Attempting to access stack memory in this manner can lead to crashes, or result in unpredictable behavior. Available in Xcode 9 and later. > Note: This check is in a disabled state by default. You can enable it under the Address Sanitizer option in the Edit Scheme dialogue. ### Use of stack memory after return in C In the following example, the `integer_pointer_returning_function` function returns a pointer to a stack variable, and there’s an attempt to access the memory of the returned pointer: ```occ int *integer_pointer_returning_function() { int value = 42; return &value; } int *integer_pointer = integer_returning_function(); *integer_pointer = 43; // Error: invalid access of returned stack memory ``` #### Solution Use pointer arguments to allow a function to return values by reference. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)