Fix PR#6056

git-svn-id: http://caml.inria.fr/svn/ocaml/trunk@13845 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02

Changes

@@ -157,7 +157,7 @@ Bug fixes:
 - PR#6031: Camomile problem with -with-frame-pointers
 - PR#6032: better Random.self_init under Windows
 - PR#6033: Matching.inline_lazy_force needs eta-expansion (command-line flags)
-
+- PR#6056: Using 'match' prevents generalization of values
 Internals:
 - Moved debugger/envaux.ml to typing/envaux.ml to publish env_of_only_summary
   as part of compilerlibs, to be used on bin-annot files.

testsuite/tests/typing-poly/poly.ml

@@ -654,3 +654,16 @@ let (A x) = (raise Exit : s);;
 (* PR#5224 *)
 
 type 'x t = < f : 'y. 'y t >;;
+
+(* PR#6056, PR#6057 *)
+let using_match b =
+  let f =
+    match b with
+    | true -> fun x -> x
+    | false -> fun x -> x
+  in
+  f 0,f
+;;
+
+match (fun x -> x), fun x -> x with x, y -> x, y;;
+match fun x -> x with x -> x, x;;

typing/typecore.ml

@@ -1288,6 +1288,9 @@ let rec is_nonexpansive exp =
   | Texp_function _ -> true
   | Texp_apply(e, (_,None,_)::el) ->
       is_nonexpansive e && List.for_all is_nonexpansive_opt (List.map snd3 el)
+  | Texp_match(e, pat_exp_list, _) ->
+      is_nonexpansive e &&
+      List.for_all (fun (pat, exp) -> is_nonexpansive exp) pat_exp_list
   | Texp_tuple el ->
       List.for_all is_nonexpansive el
   | Texp_construct( _, _, el,_) ->