[dialyzer] Re-work the handling of opaque types

It is now OK to inspect and modify the internals of opaque types within
the scope of the module.

The contracts are used for decorating types with opaqueness when it is
harmless to do so. The opaqueness is propagated by the typesig module
and also by the dataflow module.

A lot of details have been fixed or updated. In particular the modules
erl_types and erl_bif_types have been modified extensively.

The version in vsn.mk has been updated to 2.7. The reason is a
modification of #opaque{} in erl_types.

Dialyzer seems to be about five percent slower than it used to be.

1 files changed, 55 insertions, 35 deletions

diff --git a/lib/dialyzer/src/dialyzer_contracts.erl b/lib/dialyzer/src/dialyzer_contracts.erl
index 332a326b0d..3467ab4e65 100644
--- a/lib/dialyzer/src/dialyzer_contracts.erl
+++ b/lib/dialyzer/src/dialyzer_contracts.erl
@@ -2,7 +2,7 @@
 %%-----------------------------------------------------------------------
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 2007-2013. All Rights Reserved.
+%% Copyright Ericsson AB 2007-2014. All Rights Reserved.
 %%
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
@@ -21,10 +21,10 @@
 -module(dialyzer_contracts).
 
 -export([check_contract/2,
-	 check_contracts/3,
+	 check_contracts/4,
 	 contracts_without_fun/3,
 	 contract_to_string/1,
-	 get_invalid_contract_warnings/3,
+	 get_invalid_contract_warnings/4,
 	 get_contract_args/1,
 	 get_contract_return/1,
 	 get_contract_return/2,
@@ -160,17 +160,22 @@ process_contract_remote_types(CodeServer) ->
   dialyzer_codeserver:finalize_contracts(NewContractDict, NewCallbackDict,
 					 CodeServer).
 
+-type opaques() :: [erl_types:erl_type()] | 'universe'.
+-type opaques_fun() :: fun((module()) -> opaques()).
+
 -spec check_contracts([{mfa(), file_contract()}],
-		      dialyzer_callgraph:callgraph(), dict()) -> plt_contracts().
+		      dialyzer_callgraph:callgraph(), dict(),
+                      opaques_fun()) -> plt_contracts().
 
-check_contracts(Contracts, Callgraph, FunTypes) ->
+check_contracts(Contracts, Callgraph, FunTypes, FindOpaques) ->
   FoldFun =
     fun(Label, Type, NewContracts) ->
 	case dialyzer_callgraph:lookup_name(Label, Callgraph) of
 	  {ok, {M,F,A} = MFA} ->
 	    case orddict:find(MFA, Contracts) of
 	      {ok, {_FileLine, Contract}} ->
-		case check_contract(Contract, Type) of
+                Opaques = FindOpaques(M),
+		case check_contract(Contract, Type, Opaques) of
 		  ok ->
 		    case erl_bif_types:is_known(M, F, A) of
 		      true ->
@@ -192,7 +197,10 @@ check_contracts(Contracts, Callgraph, FunTypes) ->
 %% Checks all components of a contract
 -spec check_contract(#contract{}, erl_types:erl_type()) -> 'ok' | {'error', term()}.
 
-check_contract(#contract{contracts = Contracts}, SuccType) ->
+check_contract(Contract, SuccType) ->
+  check_contract(Contract, SuccType, 'universe').
+
+check_contract(#contract{contracts = Contracts}, SuccType, Opaques) ->
   try
     Contracts1 = [{Contract, insert_constraints(Constraints, dict:new())}
 		  || {Contract, Constraints} <- Contracts],
@@ -203,9 +211,9 @@ check_contract(#contract{contracts = Contracts}, SuccType) ->
       error ->
 	{error, {overlapping_contract, []}};
       ok ->
-	InfList = [erl_types:t_inf(Contract, SuccType, opaque)
+	InfList = [erl_types:t_inf(Contract, SuccType, Opaques)
 		   || Contract <- Contracts2],
-	case check_contract_inf_list(InfList, SuccType) of
+	case check_contract_inf_list(InfList, SuccType, Opaques) of
 	  {error, _} = Invalid -> Invalid;
 	  ok -> check_extraneous(Contracts2, SuccType)
 	end
@@ -217,7 +225,7 @@ check_contract(#contract{contracts = Contracts}, SuccType) ->
 check_domains([_]) -> ok;
 check_domains([Dom|Doms]) ->
   Fun = fun(D) ->
-	    erl_types:any_none_or_unit(erl_types:t_inf_lists(Dom, D, opaque))
+	    erl_types:any_none_or_unit(erl_types:t_inf_lists(Dom, D))
 	end,
   case lists:all(Fun, Doms) of
     true -> check_domains(Doms);
@@ -227,23 +235,23 @@ check_domains([Dom|Doms]) ->
 %% Allow a contract if one of the overloaded contracts is possible.
 %% We used to be more strict, e.g., all overloaded contracts had to be
 %% possible.
-check_contract_inf_list([FunType|Left], SuccType) ->
+check_contract_inf_list([FunType|Left], SuccType, Opaques) ->
   FunArgs = erl_types:t_fun_args(FunType),
   case lists:any(fun erl_types:t_is_none_or_unit/1, FunArgs) of
-    true -> check_contract_inf_list(Left, SuccType);
+    true -> check_contract_inf_list(Left, SuccType, Opaques);
     false ->
       STRange = erl_types:t_fun_range(SuccType),
       case erl_types:t_is_none_or_unit(STRange) of
 	true -> ok;
 	false ->
 	  Range = erl_types:t_fun_range(FunType),
-	  case erl_types:t_is_none(erl_types:t_inf(STRange, Range, opaque)) of
-	    true -> check_contract_inf_list(Left, SuccType);
+	  case erl_types:t_is_none(erl_types:t_inf(STRange, Range)) of
+	    true -> check_contract_inf_list(Left, SuccType, Opaques);
 	    false -> ok
 	  end
       end
   end;
-check_contract_inf_list([], _SuccType) ->
+check_contract_inf_list([], _SuccType, _Opaques) ->
   {error, invalid_contract}.
 
 check_extraneous([], _SuccType) -> ok;
@@ -259,7 +267,7 @@ check_extraneous_1(Contract, SuccType) ->
   STRng = erl_types:t_fun_range(SuccType),
   ?debug("CR = ~p\nSR = ~p\n", [CRngs, STRng]),
   case [CR || CR <- CRngs,
-              erl_types:t_is_none(erl_types:t_inf(CR, STRng, opaque))] of
+              erl_types:t_is_none(erl_types:t_inf(CR, STRng))] of
     [] ->
       CRngList = list_part(CRng),
       STRngList = list_part(STRng),
@@ -268,7 +276,7 @@ check_extraneous_1(Contract, SuccType) ->
         true ->
           CRngElements = erl_types:t_list_elements(CRngList),
           STRngElements = erl_types:t_list_elements(STRngList),
-          Inf = erl_types:t_inf(CRngElements, STRngElements, opaque),
+          Inf = erl_types:t_inf(CRngElements, STRngElements),
           case erl_types:t_is_none(Inf) of
             true -> {error, invalid_contract};
             false -> ok
@@ -278,7 +286,7 @@ check_extraneous_1(Contract, SuccType) ->
   end.
 
 list_part(Type) ->
-  erl_types:t_inf(erl_types:t_list(), Type, opaque).
+  erl_types:t_inf(erl_types:t_list(), Type).
 
 is_not_nil_list(Type) ->
   erl_types:t_is_list(Type) andalso not erl_types:t_is_nil(Type).
@@ -374,7 +382,7 @@ insert_constraints([], Dict) -> Dict.
 store_tmp_contract(MFA, FileLine, TypeSpec, SpecDict, RecordsDict) ->
   %% io:format("contract from form: ~p\n", [TypeSpec]),
   TmpContract = contract_from_form(TypeSpec, RecordsDict, FileLine),
-  %% io:format("contract: ~p\n", [Contract]),
+  %% io:format("contract: ~p\n", [TmpContract]),
   dict:store(MFA, {FileLine, TmpContract}, SpecDict).
 
 contract_from_form(Forms, RecDict, FileLine) ->
@@ -494,30 +502,35 @@ general_domain([], AccSig) ->
   AccSig1 = erl_types:subst_all_vars_to_any(AccSig),
   erl_types:t_fun_args(AccSig1).
 
--spec get_invalid_contract_warnings([module()], dialyzer_codeserver:codeserver(), dialyzer_plt:plt()) -> [dial_warning()].
+-spec get_invalid_contract_warnings([module()],
+                                    dialyzer_codeserver:codeserver(),
+                                    dialyzer_plt:plt(),
+                                    opaques_fun()) -> [dial_warning()].
 
-get_invalid_contract_warnings(Modules, CodeServer, Plt) ->
-  get_invalid_contract_warnings_modules(Modules, CodeServer, Plt, []).
+get_invalid_contract_warnings(Modules, CodeServer, Plt, FindOpaques) ->
+  get_invalid_contract_warnings_modules(Modules, CodeServer, Plt, FindOpaques, []).
 
-get_invalid_contract_warnings_modules([Mod|Mods], CodeServer, Plt, Acc) ->
+get_invalid_contract_warnings_modules([Mod|Mods], CodeServer, Plt, FindOpaques, Acc) ->
   Contracts1 = dialyzer_codeserver:lookup_mod_contracts(Mod, CodeServer),
   Contracts2 = dict:to_list(Contracts1),
   Records = dialyzer_codeserver:lookup_mod_records(Mod, CodeServer),
-  NewAcc = get_invalid_contract_warnings_funs(Contracts2, Plt, Records, Acc),
-  get_invalid_contract_warnings_modules(Mods, CodeServer, Plt, NewAcc);
-get_invalid_contract_warnings_modules([], _CodeServer, _Plt, Acc) ->
+  NewAcc = get_invalid_contract_warnings_funs(Contracts2, Plt, Records, FindOpaques, Acc),
+  get_invalid_contract_warnings_modules(Mods, CodeServer, Plt, FindOpaques, NewAcc);
+get_invalid_contract_warnings_modules([], _CodeServer, _Plt, _FindOpaques, Acc) ->
   Acc.
 
 get_invalid_contract_warnings_funs([{MFA, {FileLine, Contract}}|Left],
-				   Plt, RecDict, Acc) ->
+				   Plt, RecDict, FindOpaques, Acc) ->
   case dialyzer_plt:lookup(Plt, MFA) of
     none ->
       %% This must be a contract for a non-available function. Just accept it.
-      get_invalid_contract_warnings_funs(Left, Plt, RecDict, Acc);
+      get_invalid_contract_warnings_funs(Left, Plt, RecDict, FindOpaques, Acc);
     {value, {Ret, Args}} ->
       Sig = erl_types:t_fun(Args, Ret),
+      {M, _F, _A} = MFA,
+      Opaques = FindOpaques(M),
       NewAcc =
-	case check_contract(Contract, Sig) of
+	case check_contract(Contract, Sig, Opaques) of
 	  {error, invalid_contract} ->
 	    [invalid_contract_warning(MFA, FileLine, Sig, RecDict)|Acc];
 	  {error, {overlapping_contract, []}} ->
@@ -551,7 +564,7 @@ get_invalid_contract_warnings_funs([{MFA, {FileLine, Contract}}|Left],
 		BifArgs = erl_bif_types:arg_types(M, F, A),
 		BifRet = erl_bif_types:type(M, F, A),
 		BifSig = erl_types:t_fun(BifArgs, BifRet),
-		case check_contract(Contract, BifSig) of
+		case check_contract(Contract, BifSig, Opaques) of
 		  {error, _} ->
 		    [invalid_contract_warning(MFA, FileLine, BifSig, RecDict)
 		     |Acc];
@@ -564,9 +577,9 @@ get_invalid_contract_warnings_funs([{MFA, {FileLine, Contract}}|Left],
 				     RecDict, Acc)
 	    end
 	end,
-      get_invalid_contract_warnings_funs(Left, Plt, RecDict, NewAcc)
+      get_invalid_contract_warnings_funs(Left, Plt, RecDict, FindOpaques, NewAcc)
   end;
-get_invalid_contract_warnings_funs([], _Plt, _RecDict, Acc) ->
+get_invalid_contract_warnings_funs([], _Plt, _RecDict, _FindOpaques, Acc) ->
   Acc.
 
 invalid_contract_warning({M, F, A}, FileLine, SuccType, RecDict) ->
@@ -601,16 +614,23 @@ picky_contract_check(CSig0, Sig0, MFA, FileLine, Contract, RecDict, Acc) ->
   end.
 
 extra_contract_warning({M, F, A}, FileLine, Contract, CSig, Sig, RecDict) ->
-  SigString = lists:flatten(dialyzer_utils:format_sig(Sig, RecDict)),
-  ContractString0 = lists:flatten(dialyzer_utils:format_sig(CSig, RecDict)),
+  %% We do not want to depend upon erl_types:t_to_string() possibly
+  %% hiding the contents of opaque types.
+  SigUnopaque = erl_types:t_unopaque(Sig),
+  CSigUnopaque = erl_types:t_unopaque(CSig),
+  SigString0 =
+    lists:flatten(dialyzer_utils:format_sig(SigUnopaque, RecDict)),
+  ContractString0 =
+    lists:flatten(dialyzer_utils:format_sig(CSigUnopaque, RecDict)),
   %% The only difference is in record fields containing 'undefined' or not.
-  IsUndefRecordFieldsRelated = SigString =:= ContractString0,
+  IsUndefRecordFieldsRelated = SigString0 =:= ContractString0,
   {IsRemoteTypesRelated, SubtypeRelation} =
     is_remote_types_related(Contract, CSig, Sig, RecDict),
   case IsUndefRecordFieldsRelated orelse IsRemoteTypesRelated of
     true ->
       no_warning;
     false ->
+      SigString = lists:flatten(dialyzer_utils:format_sig(Sig, RecDict)),
       ContractString = contract_to_string(Contract),
       {Tag, Msg} =
 	case SubtypeRelation of