Integrate LRgrep error messages - #2072
Open
let-def wants to merge 7 commits into
Open
Conversation
Collaborator
|
Thanks a lot @let-def ! As you probably noticed we merged the upgrade to 5.5 after you opened this PR. Now we need to rebase it and I would like to use that as an occasion to learn about what it adds to the upgrade process. I will start doing that today ! |
Collaborator
|
Du you think it would be useful to have a ci that diffs lr grep's coverage output ? |
voodoos
reviewed
Jul 6, 2026
| { "Expected constructor or operator after `(`" } | ||
|
|
||
| | /constr_ident: LPAREN COLONCOLON . RPAREN | ||
| | /mk_longident(mod_ext_longident,__anonymous_42): LPAREN COLONCOLON . RPAREN |
Collaborator
There was a problem hiding this comment.
@let-def What are these __anonymous_42 ? Is it some menhir internal ?
(I am using https://cambium.inria.fr/~fpottier/publis/bour-pottier-lrgrep-2026.pdf to try to decipher this file, but it's not mentioned there)
Contributor
Author
There was a problem hiding this comment.
It's indeed the names generated by menhir when lambda lifting. Not much I can do about that.
Contributor
Author
There was a problem hiding this comment.
(at the moment, but it would be nice to cleanup later!)
Collaborator
There was a problem hiding this comment.
How can one know which anonymous is associated to which lambda ? For the upgrade it became invalid and I used the one suggested in the error message.
Collaborator
|
Useful links for review: |
Collaborator
|
After getting rid of many errors when rebased on 5.5 I was finally able to run lrgrep... But is it expected that it takes several minutes to complete ? Some backtrace: And another one a few seconds later: |
Collaborator
|
I stopped it after 20 minutes, something is clearly wrong... |
Collaborator
|
Pinning on lrgrep's main branch fixes the loop ! Still a few fixes to make however 😅 |
Collaborator
|
Unrelated question @let-def, but is there anything that would block this from being merged upstream ? Does it rely on the recovery ? |
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
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
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.
This PR integrates LRgrep to generate syntax error messages. This change improves the quality and consistency of error reporting while, hopefully, making the error-handling logic more maintainable. Currently, this is an additive change that complements the existing parser without modifying or removing any existing behavior.
Main changes:
src/ocaml/preprocess/parse_errors.lrgrep, which defines syntax error messages in a clear, declarative format.make lrgrep-coveragetarget generatescoverage.md, a report listing grammatical constructs that currently lack error messages, along with actionable hints for adding coverage.src/ocaml/preprocess/, following the same vendoring pattern used forMenhirLib.The declarative approach should make error messages easier to write, review, and maintain. The coverage tool gives us visibility into error-reporting gaps and guides incremental improvements.
While this PR is a strict addition, the long-term goal is to gradually replace parser components with a version more tightly integrated with LRgrep. This will significantly simplify the preprocessing pipeline and reduce boilerplate in the error recovery and explanation code.