Summary

Updates landmarks-ppx for compatibility with ppxlib 0.36.0, which changed the internal AST representation to OCaml 5.2.

Breaking Change

Requires ppxlib >= 0.36.0.

This version is not compatible with ppxlib < 0.36.0 due to AST representation change.

Notes

Changes are localized to ppx/mapper.ml.

I did simple rewrites of the arity function (line 177) and wrap_landmark_method function (line 204) to work with the new Pexp_function AST node and preserve landmarks behavior as much as possible.

Critical fix: keep pvb_constraint when rebuilding value binding (line 272). This allows the following minimal examples to compile because of their necessary type annotations.

type _ t =
  | A : int t
  | B : bool t

let f : type a. a t -> bool = function
  | A -> true
  | B -> false

And

type empty = private | 

let absurd : 'a. empty -> 'a = function _ -> .

Testing

I verify that the above examples compile with instrumentation. I also profile a simple fib program using function to check that output is identical previous releases. I then instrument a small project (about 2000 lines) with several modules, and to my eye, the output is as expected. That small project uses a menhir parser (whose outputted code can be instrumented with landmarks-ppx) and polymorphic recursion with GADTs, for example, so it reasonably covers a few features I might expect to break if this ppx upgrade was buggy.

All of the above testing was done with the --auto flag to ppx annotate all functions.

This code (from README.md) still fails to compile:

let test = (fun x -> x)[@landmark "test"]
in test "string", test 1