[libcxx-commits] [PATCH] D136765: [ASan][libcxx] Annotating std::vector with all allocators

Wed Mar 8 07:37:44 PST 2023

philnik added a comment.

In D136765#4178116 <https://reviews.llvm.org/D136765#4178116>, @manojgupta wrote:

> In D136765#4178089 <https://reviews.llvm.org/D136765#4178089>, @hans wrote:
>
>> In D136765#4173661 <https://reviews.llvm.org/D136765#4173661>, @ayzhao wrote:
>>
>>> FYI this is causing (yet another) bug on Chrome/Chrome OS: https://crbug.com/1422033
>>
>> We've root caused this to ChromeOS using a toolchain based on llvmorg-16-init-6711-g11897708c022, which is before the ASan runtime gained support for unaligned container memory in llvmorg-16-init-9006-gdd1b7b797a11, which this patch depends on. (https://crbug.com/1422033#c11 has a reproducer).
>>
>> I see that the patch is already trying to handle this with the `#if _LIBCPP_CLANG_VER >= 1600` check. However, that doesn't quite work since there were many revisions with that version number before the ASan change.
>>
>> Should it be checking `_LIBCPP_CLANG_VER >= 1700` instead, or is there some more precise way to handle this? (Does the ASan runtime have some way to check if it supports this for example?)
>
> Afaik, this is against libc++ policy. libc++ needs to work with at least 1 or 2 last clang releases so this patch needs to accomodate it.
> @ldionne to confirm.

The last two official releases. It doesn't seem like ChromeOS uses that, given that LLVM16 isn't released yet. Anyways, I think we have to revert, since we clearly need some way to fix the annotation problems, and that will probably take some time to figure out.

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https://reviews.llvm.org/D136765