From 08c3b1780a8771124c21efa07155cd8672a13ca6 Mon Sep 17 00:00:00 2001
From: Alain Frisch <alain@frisch.fr>
Date: Fri, 12 Oct 2012 08:24:34 +0000
Subject: [PATCH] PR#5787: Bad behavior of 'Unused ...' warnings in the
 toplevel.

git-svn-id: http://caml.inria.fr/svn/ocaml/trunk@13010 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02
---
 Changes             |  1 +
 toplevel/toploop.ml |  2 +-
 typing/env.ml       | 18 +++++++++++++-----
 typing/env.mli      |  4 +++-
 4 files changed, 18 insertions(+), 7 deletions(-)

diff --git a/Changes b/Changes
index d51958d9d..ba4255a49 100644
--- a/Changes
+++ b/Changes
@@ -26,6 +26,7 @@ Bug fixes:
 - PR#5747: 'unused open' warning not given when compiling with -annot
 - PR#5758: Compiler bug when matching on floats
 - PR#5763: ocamlbuild does not give correct flags when running menhir
+- PR#5787: Bad behavior of 'Unused ...' warnings in the toplevel
 
 Internals:
 - Moved debugger/envaux.ml to typing/envaux.ml to publish env_of_only_summary
diff --git a/toplevel/toploop.ml b/toplevel/toploop.ml
index f75e27b19..821561587 100644
--- a/toplevel/toploop.ml
+++ b/toplevel/toploop.ml
@@ -422,7 +422,7 @@ let loop ppf =
       first_line := true;
       let phr = try !parse_toplevel_phrase lb with Exit -> raise PPerror in
       if !Clflags.dump_parsetree then Printast.top_phrase ppf phr;
-      Env.reset_missing_cmis ();
+      Env.reset_cache_toplevel ();
       ignore(execute_phrase true ppf phr)
     with
     | End_of_file -> exit 0
diff --git a/typing/env.ml b/typing/env.ml
index c287e1dc6..47cd1f005 100644
--- a/typing/env.ml
+++ b/typing/env.ml
@@ -329,13 +329,21 @@ let reset_cache () =
   Hashtbl.clear persistent_structures;
   Consistbl.clear crc_units;
   Hashtbl.clear value_declarations;
-  Hashtbl.clear type_declarations
+  Hashtbl.clear type_declarations;
+  Hashtbl.clear used_constructors
 
-let reset_missing_cmis () =
-  let l = Hashtbl.fold
+let reset_cache_toplevel () =
+  (* Delete 'missing cmi' entries from the cache. *)
+  let l =
+    Hashtbl.fold
       (fun name r acc -> if r = None then name :: acc else acc)
-      persistent_structures [] in
-  List.iter (Hashtbl.remove persistent_structures) l
+      persistent_structures []
+  in
+  List.iter (Hashtbl.remove persistent_structures) l;
+  Hashtbl.clear value_declarations;
+  Hashtbl.clear type_declarations;
+  Hashtbl.clear used_constructors
+
 
 let set_unit_name name =
   current_unit := name
diff --git a/typing/env.mli b/typing/env.mli
index e6fa36542..71680ebba 100644
--- a/typing/env.mli
+++ b/typing/env.mli
@@ -108,7 +108,9 @@ val enter_cltype: string -> class_type_declaration -> t -> Ident.t * t
 
 (* Initialize the cache of in-core module interfaces. *)
 val reset_cache: unit -> unit
-val reset_missing_cmis: unit -> unit
+
+(* To be called before each toplevel phrase. *)
+val reset_cache_toplevel: unit -> unit
 
 (* Remember the name of the current compilation unit. *)
 val set_unit_name: string -> unit