replaces dangling pointers in initarray with indexes #225
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
In `initarray`, `prev1` and `prev2` are dangling pointers. When assigned, they point to an address of an item in the literal queue. The compiler checks the literal queue size before adding an element. If the size isn't sufficient to hold another element, it reallocates the literal queue to accommodate more items. When the reallocation happens, the previous references (`prev1` and `prev2`) to the elements of the literal queue are invalidated. De-referencing the broken pointers will cause undefined behavior. This commit replaces the pointers with indexes. The indexes are invariant to the reallocation.
|
Nice catch 👍 |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
fix for #220
In
initarray,prev1andprev2are dangling pointers. When assigned, they point to an address of an item in the literal queue. The compiler checks (litadd) the literal queue size before adding an element. If the size isn't sufficient to hold another element, it reallocates the literal queue to accommodate more items. When the reallocation happens, the previous references (prev1andprev2) to the elements of the literal queue are invalidated. De-referencing the broken pointers will cause undefined behavior.This commit replaces the pointers with indexes. The indexes are invariant to the reallocation.