A cross-function checking possibility

[jongleb]

Please support to check if functions are called from the other. Let me show an example. Let me show an example.

This is the code I need to check. I need to check if I use an argument in concurrent mode.

  let use_thing thing = 
    let%bind () = fn1 thing
    and _ = fn2 thing in
    return ()

  let other_fn () = get_thing use_thing

And it works when this function is inside the function where get_thing is called.

rules:
  - id: concurrent-use
    patterns:
      - pattern-inside:
          pattern-either:
            - pattern: get_thing (fun $THING -> ...)
            - pattern: get_thing @@ fun $THING -> ...
            - pattern: let $FN_NAME $THING = ... in get_thing  $FN_NAME
      - pattern-either:
          - pattern: let $X = ... $THING ... and $Y = ... $THING ... in ...
          - pattern: let () = ... $THING ... and () = ... $THING ... in ...
          - pattern: let $X = ... $THING ... and () = ... $THING ... in ...
          - pattern: let () = ... $THING ... and $Y = ... $THING ... in ...
    languages:
      - ocaml
    severity: ERROR

And this could be rewritten with the following pattern (at least the same idea works for typescript and python)

rules:
  - id: concurrent-use
    patterns:
      - pattern:
            let $F $THING = ...
            ...
            get_thing  $F
      - pattern-either:
          - pattern: let $X = ... $THING ... and $Y = ... $THING ... in ...
          - pattern: let () = ... $THING ... and () = ... $THING ... in ...
          - pattern: let $X = ... $THING ... and () = ... $THING ... in ...
          - pattern: let () = ... $THING ... and $Y = ... $THING ... in ...
    message: Semgrep found a match
    languages:
      - ocaml
    severity: ERROR

But nothing is caught.

I tried this version (which is worked for typescript too):

- pattern:
            let $F $THING = ...
            ...
            let $ANOTHER_FN ... = get_thing  $F

But I caught: Invalid pattern for OCaml: