Don't cache dep file #2322
Open
Don't cache dep file #2322
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
sccache has two modes: - normal mode - preprocessor cache mode (aka direct mode in ccache) In the former case, the preprocessor is invoked and creates the dep file itself. Whatever sccache does after that is going to overwrite a fresh file with potentially wrong information, since the cache key is not indexed on the elements that would affect the contents of the dep file, resulting in issue mozilla#2321. In the latter case, sccache currently doesn't handle the situation appropriately (issue mozilla#2194), which is why preprocessor cache mode is automatically disabled when the dependency flags are on the command line (mozilla#2195). Which also means we fallback to the case above.
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Outdated suggestions cannot be applied.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.
sccache has two modes:
In the former case, the preprocessor is invoked and creates the dep file itself. Whatever sccache does after that is going to overwrite a fresh file with potentially wrong information, since the cache key is not indexed on the elements that would affect the contents of the dep file, resulting in issue #2321.
In the latter case, sccache currently doesn't handle the situation appropriately (issue #2194), which is why preprocessor cache mode is automatically disabled when the dependency flags are on the command line (#2195). Which also means we fallback to the case above.