Add proper error for attempted use of undef slot #50556
Merged
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
Fixes the segfault in #50518 and turns it into a proper error at both the syntax level (to catch lowering generating bad slot references) as well as at the codegen level (to catch e.g. bad generated functions and opaque closures). However, note that the latter case is technically undefined behavior, because we do not model the possibility that an otherwise-defined argument could throw at access time. Of course, throwing an error is allowable as undefined behavior and preferable to a segfault.
Keno
added a commit
that referenced
this pull request
Jul 14, 2023
Fixes the case from #50518, but we actually have two test cases in the tests that also hit this (e.g. this one: ``` f40964(xs::Int...=1; k = 2) = (xs, k) ```), but just happened not to hit the bad codegen path. #50556, once merged would have complained on those definitions as well, without this fix.
|
#50559 needs to be merged first for this not to error, since we actually had a test that triggered the bad lowering. |
vtjnash
approved these changes
Jul 15, 2023
| @@ -296,7 +296,7 @@ | |||
| (if (eq? n '|#self#|) (gensy) n)) | |||
| arg-names)))) | |||
| (let ((body (insert-after-meta body ;; don't specialize on generator arguments | |||
| `((meta nospecialize ,@arg-names))))) | |||
| `((meta nospecialize ,@(map (lambda (idx) `(slot ,(+ idx 1))) (iota (length arg-names)))))))) | |||
There was a problem hiding this comment.
IIRC, there was previously a bug (and open issue) that vararg arguments didn't get nospecialize'd for macros. Any idea if this fixed it?
There was a problem hiding this comment.
I don't think so. This is for generated functions.
github-merge-queue bot
pushed a commit
that referenced
this pull request
Jul 15, 2023
Fixes the case from #50518, but we actually have two test cases in the tests that also hit this (e.g. this one: ``` f40964(xs::Int...=1; k = 2) = (xs, k) ``` ), but just happened not to hit the bad codegen path. #50556, once merged would have complained on those definitions as well, without this fix.
I agree with this, but that's a pre-existing issue. I wouldn't really have a problem with ripping out the whole special |
Keno
added a commit
that referenced
this pull request
Jul 17, 2023
I had an off-by-one in #50556, since the argument slots actually start at 2 and `iota` starts at `0`. This was breaking StaticArrays precompiles, which attempts to precompile a generator with its abstract signature and without the nospecialize, those signatures are not compileable.
KristofferC
pushed a commit
that referenced
this pull request
Jul 17, 2023
Fixes the case from #50518, but we actually have two test cases in the tests that also hit this (e.g. this one: ``` f40964(xs::Int...=1; k = 2) = (xs, k) ```), but just happened not to hit the bad codegen path. #50556, once merged would have complained on those definitions as well, without this fix. (cherry picked from commit c272236)
Keno
added a commit
that referenced
this pull request
Jul 18, 2023
I had an off-by-one in #50556, since the argument slots actually start at 2 and `iota` starts at `0`. This was breaking StaticArrays precompiles, which attempts to precompile a generator with its abstract signature and without the nospecialize, those signatures are not compileable. Co-authored-by: Oscar Smith <[email protected]>
KristofferC
pushed a commit
that referenced
this pull request
Aug 10, 2023
Fixes the case from #50518, but we actually have two test cases in the tests that also hit this (e.g. this one: ``` f40964(xs::Int...=1; k = 2) = (xs, k) ```), but just happened not to hit the bad codegen path. #50556, once merged would have complained on those definitions as well, without this fix. (cherry picked from commit c272236)
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.
Fixes the segfault in #50518 and turns it into a proper error at both the syntax level (to catch lowering generating bad slot references) as well as at the codegen level (to catch e.g. bad generated functions and opaque closures). However, note that the latter case is technically undefined behavior, because we do not model the possibility that an otherwise-defined argument could throw at access time. Of course, throwing an error is allowable as undefined behavior and preferable to a segfault.