diff options
| author | Kazuhiko Sakaguchi | 2019-08-09 21:19:16 +0200 |
|---|---|---|
| committer | Kazuhiko Sakaguchi | 2019-08-10 20:33:48 +0200 |
| commit | 970404f2bfa7a26ad64692844441261cebd80082 (patch) | |
| tree | 68f76ecb0664017f2988b44ba006b73a8960835c | |
| parent | b8477fb38842016c226ba9d7be8f60486411a2ee (diff) | |
[extraction] Fix #7191: Avoid unsound eta-reduction
`Mlutil.simpl` and `Mlutil.atomic_eta_red` did some unsound eta-reductions as
follows:
(fun x0 ... xn => MLexn x0 ... xn) ->eta MLexn.
`MLexn` raises an exception thus is not a value in OCaml. So the above
simplification may change the behavior of extracted programs. This patch
restricts `atomic_eta_red` to eta-redexes whose core is both atomic and value.
Acknowledgement: This work is financially supported by Peano System Inc.
on-behalf-of: @peano-system <info@peano-system.jp>
| -rw-r--r-- | plugins/extraction/mlutil.ml | 4 | ||||
| -rw-r--r-- | test-suite/output/bug7191.out | 9 | ||||
| -rw-r--r-- | test-suite/output/bug7191.v | 3 |
3 files changed, 14 insertions, 2 deletions
diff --git a/plugins/extraction/mlutil.ml b/plugins/extraction/mlutil.ml index 2d5872718f..c57daf0047 100644 --- a/plugins/extraction/mlutil.ml +++ b/plugins/extraction/mlutil.ml @@ -779,7 +779,7 @@ let eta_red e = else e | _ -> e -(* Performs an eta-reduction when the core is atomic, +(* Performs an eta-reduction when the core is atomic and value, or otherwise returns None *) let atomic_eta_red e = @@ -789,7 +789,7 @@ let atomic_eta_red e = | MLapp (f,a) when test_eta_args_lift 0 n a -> (match f with | MLrel k when k>n -> Some (MLrel (k-n)) - | MLglob _ | MLexn _ | MLdummy _ -> Some f + | MLglob _ | MLdummy _ -> Some f | _ -> None) | _ -> None diff --git a/test-suite/output/bug7191.out b/test-suite/output/bug7191.out new file mode 100644 index 0000000000..005455e30c --- /dev/null +++ b/test-suite/output/bug7191.out @@ -0,0 +1,9 @@ + +type unit0 = +| Tt + +(** val f : unit0 -> unit0 **) + +let f _ = + assert false (* absurd case *) + diff --git a/test-suite/output/bug7191.v b/test-suite/output/bug7191.v new file mode 100644 index 0000000000..1aa4625b6c --- /dev/null +++ b/test-suite/output/bug7191.v @@ -0,0 +1,3 @@ +Require Extraction. +Definition f (x : False) : unit -> unit := match x with end. +Recursive Extraction f. |