Fix string::assign and ::resize_and_overwrite under ASan
#3956
Conversation
This file contains 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
strega-nil-ms
approved these changes
Aug 15, 2023
The argument may alias `*this`, so don't shrink until after we copy the characters.
We need to update the buffer info even if we do not allocate.
Compare the converted "result size" to the "new size" so we don't need to suppress C4108. Improves readability and throughput a teeny bit.
CaseyCarter
changed the title
string::assign under ASanstring::assign and ::resize_and_overwrite under ASan
CaseyCarter
approved these changes
Aug 15, 2023
strega-nil
approved these changes
Aug 15, 2023
StephanTLavavej
approved these changes
Aug 16, 2023
|
Sorry for my oversight😿 I've add a test for the problem introduced by my "fix". |
StephanTLavavej
approved these changes
Aug 16, 2023
CaseyCarter
approved these changes
Aug 16, 2023
|
I'm mirroring this to the MSVC-internal repo - please notify me if any further changes are pushed. |
|
Thanks for fixing these bugs in one of the STL's most popular types and one of MSVC's most important new features! 😻 🐞 🛠️ |
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Outdated suggestions cannot be applied.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.
Fixes #3955 / VSO-1854254 / AB#1854254 (fix string's self-assignment with offset via pointers under ASan)
Fixes VSO-1854245 / AB#1854245 "ASan issue in
basic_string::assign(pointer)"Fixes VSO-1854251 / AB#1854251 "ASan issue in
basic_string::assign(iterator, iterator)"Fixes VSO-1854242 / AB#1854242 "ASan issue in
tests/std/P0980R1_constexpr_strings[basic_string::resize_and_overwrite]"Drive-by: In
resize_and_overwrite, compare the converted result size so we need not suppress the "comparing signed and unsigned" warning.Test coverage for the latter three fixes will be in the ASan test coverage that's incoming in the near future.