[NFC] Reduce SwiftParser stack usage in debug mode #3160
+1,131
−849
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
beccadax
requested review from
ahoppen,
bnbarham,
hamishknight and
rintaro
as code owners
|
Ooo, thanks for looking into this @beccadax!
|
I’ve had trouble running SwiftParser’s tests—particularly the torture tests in the swiftlang/swift repo—locally in debug mode because some common parser functions would use many kilobytes of stack for each call, consuming the stack too quickly for the `maximumNestingLevel` to control. Break up a number of problematic functions to help with this, and also insert a missing stack overflow check in `parseClosureExpression()`.
|
I'll wait for Hamish's input, but a quick run on the swift-syntax/Sources directory was actually about 1% faster than main, so that's promising. |
|
@swift-ci please test |
|
@swift-ci please test Windows platform |
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Outdated suggestions cannot be applied.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.
I’ve had trouble running SwiftParser’s tests—particularly the torture tests in the swiftlang/swift repo—locally in debug mode because some common parser functions would use many kilobytes of stack for each call, consuming the stack too quickly for even a low
maximumNestingLevelto control. Break up a number of problematic functions to help with this, and also insert a missing stack overflow check inparseClosureExpression().Each of the functions I've broken up previously used 4-11K of stack and appeared in a backtrace of a test case that crashed because of a stack overflow, either repeatedly or very close to the top of the stack.
I haven't determined if these changes regress release-mode performance; if they do, we probably shouldn't take them.