From 050d93682e07e0c50667dbfb1468389078b776f2 Mon Sep 17 00:00:00 2001
From: Hans Bolinder <hasse@erlang.org>
Date: Tue, 18 Aug 2015 14:54:29 +0200
Subject: dialyzer: Fix a bug concerning parameterized opaque types

The example is provided by James Fish in
http://erlang.org/pipermail/erlang-questions/2014-December/082204.html.

Note that warnings with text such as "the _ variable breaks
opaqueness" are still possible.
---
 .../test/opaque_SUITE_data/src/para/myqueue.erl         | 17 +++++++++++++++++
 .../test/opaque_SUITE_data/src/para/myqueue_params.erl  | 15 +++++++++++++++
 lib/hipe/cerl/erl_types.erl                             | 12 ++++++++----
 3 files changed, 40 insertions(+), 4 deletions(-)
 create mode 100644 lib/dialyzer/test/opaque_SUITE_data/src/para/myqueue.erl
 create mode 100644 lib/dialyzer/test/opaque_SUITE_data/src/para/myqueue_params.erl

diff --git a/lib/dialyzer/test/opaque_SUITE_data/src/para/myqueue.erl b/lib/dialyzer/test/opaque_SUITE_data/src/para/myqueue.erl
new file mode 100644
index 0000000000..0f76680464
--- /dev/null
+++ b/lib/dialyzer/test/opaque_SUITE_data/src/para/myqueue.erl
@@ -0,0 +1,17 @@
+-module(myqueue).
+
+-export([new/0, in/2]).
+
+-record(myqueue, {queue = queue:new() :: queue:queue({integer(), _})}).
+
+-opaque myqueue(Item) :: #myqueue{queue :: queue:queue({integer(), Item})}.
+
+-export_type([myqueue/1]).
+
+-spec new() -> myqueue(_).
+new() ->
+    #myqueue{queue=queue:new()}.
+
+-spec in(Item, myqueue(Item)) -> myqueue(Item).
+in(Item, #myqueue{queue=Q}) ->
+    #myqueue{queue=queue:in({1, Item}, Q)}.
diff --git a/lib/dialyzer/test/opaque_SUITE_data/src/para/myqueue_params.erl b/lib/dialyzer/test/opaque_SUITE_data/src/para/myqueue_params.erl
new file mode 100644
index 0000000000..8d766b7804
--- /dev/null
+++ b/lib/dialyzer/test/opaque_SUITE_data/src/para/myqueue_params.erl
@@ -0,0 +1,15 @@
+-module(myqueue_params).
+
+-export([new/0, in/2]).
+
+-record(myqueue_params, {myqueue = myqueue:new() :: myqueue:myqueue(integer())}).
+
+-type myqueue_params() :: #myqueue_params{myqueue ::
+                                          myqueue:myqueue(integer())}.
+-spec new() -> myqueue_params().
+new() ->
+    #myqueue_params{myqueue=myqueue:new()}.
+
+-spec in(integer(), myqueue_params()) -> myqueue_params().
+in(Item, #myqueue_params{myqueue=Q} = P) when is_integer(Item) ->
+    P#myqueue_params{myqueue=myqueue:in(Item, Q)}.
diff --git a/lib/hipe/cerl/erl_types.erl b/lib/hipe/cerl/erl_types.erl
index 25cf1a7ae1..a28dfb9e05 100644
--- a/lib/hipe/cerl/erl_types.erl
+++ b/lib/hipe/cerl/erl_types.erl
@@ -4244,9 +4244,8 @@ type_from_form(Name, Args, TypeNames, ET, M, MR, V, D, L) ->
       Rep2 = case t_is_none(Rep1) of
                true -> Rep1;
                false ->
-                 Args2 = [subst_all_vars_to_any(ArgType) ||
-                           ArgType <- ArgTypes],
-                 t_opaque(Module, Name, Args2, Rep1)
+                 ArgTypes2 = subst_all_vars_to_any_list(ArgTypes),
+                 t_opaque(Module, Name, ArgTypes2, Rep1)
              end,
       {Rep2, L2};
     error ->
@@ -4298,7 +4297,9 @@ remote_from_form(RemMod, Name, Args, TypeNames, ET, M, MR, V, D, L) ->
                   NewRep1 = choose_opaque_type(NewRep, Type),
                   NewRep2 = case t_is_none(NewRep1) of
                      true -> NewRep1;
-                     false -> t_opaque(Mod, Name, ArgTypes, NewRep1)
+                     false ->
+                       ArgTypes2 = subst_all_vars_to_any_list(ArgTypes),
+                       t_opaque(Mod, Name, ArgTypes2, NewRep1)
                    end,
                   {NewRep2, L2};
                 error ->
@@ -4313,6 +4314,9 @@ remote_from_form(RemMod, Name, Args, TypeNames, ET, M, MR, V, D, L) ->
       end
   end.
 
+subst_all_vars_to_any_list(Types) ->
+  [subst_all_vars_to_any(Type) || Type <- Types].
+
 %% Opaque types (both local and remote) are problematic when it comes
 %% to the limits (TypeNames, D, and L). The reason is that if any() is
 %% substituted for a more specialized subtype of an opaque type, the
-- 
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