cmake: Disable PartitionAlloc on ARM #446
Closed
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
PartitionAlloc needs to be built with -ffixed-x18 on ARM to avoid clobbering x18. However linking it in also pulls in libstdc++ which can also clobber x18 so this commit just disables PartitionAlloc on ARM for now. It shouldn't be too hard to build LLVM's libc++ with -ffixed-x18 since that's what Android uses so we should probably just do that when we want to re-enable PA.
|
Is libstdc++ being linked causing problems even in tests that don't do heap allocation? If not, I would rather we kept PartitionAlloc in the build and just ignored test failures of heap tests until we have our own build of libc++. We have ARM-specific changes to PartitionAlloc that I would prefer to keep building in CI. |
|
No I haven't hit runtime bugs due to this, it was to preempt potential bugs from calling into it. Though libstdc++.so also defines some unmangled symbols so I don't think we can say with certainty that not allocating will not call into libstdc++.so. If you want to keep building PA we could add |
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Outdated suggestions cannot be applied.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.
PartitionAlloc needs to be built with -ffixed-x18 on ARM to avoid clobbering x18. However linking it in also pulls in libstdc++ which can also clobber x18 so this commit just disables PartitionAlloc on ARM for now. It shouldn't be too hard to build LLVM's libc++ with -ffixed-x18 since that's what Android uses so we should probably just do that when we want to re-enable PA.