[lldb] [ObjectFileMachO] LLVM_COV is not mapped into firmware memory (#86359) #8475
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
…lvm#86359) It is possible to gather code coverage in a firmware environment, where the __LLVM_COV segment will not be mapped in memory but does exist in the binary, see https://llvm.org/devmtg/2020-09/slides/PhippsAlan_EmbeddedCodeCoverage_LLVM_Conf_Talk_final.pdf The __LLVM_COV segment in the binary happens to be at the same address as the __DATA segment, so if lldb treats this segment as loaded, it shadows the __DATA segment and address->symbol resolution can fail. For these non-userland code cases, we need to mark __LLVM_COV as not a loadable segment. rdar://124475661 (cherry picked from commit 765d4c4)
|
@swift-ci test |
jasonmolenda
changed the title
|
@swift-ci test windows |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
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Outdated suggestions cannot be applied.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.
It is possible to gather code coverage in a firmware environment, where the __LLVM_COV segment will not be mapped in memory but does exist in the binary, see
https://llvm.org/devmtg/2020-09/slides/PhippsAlan_EmbeddedCodeCoverage_LLVM_Conf_Talk_final.pdf
The __LLVM_COV segment in the binary happens to be at the same address as the __DATA segment, so if lldb treats this segment as loaded, it shadows the __DATA segment and address->symbol resolution can fail.
For these non-userland code cases, we need to mark __LLVM_COV as not a loadable segment.
rdar://124475661
(cherry picked from commit 765d4c4)