stdlib: Emit linter warnings for redefined built-in types

Since Erlang/OTP R16B the linter has not emitted warnings when
built-in types were re-defined. This bug has been fixed.

Thanks to Roberto Aloi for reporting the bug.

2 files changed, 78 insertions, 35 deletions

diff --git a/lib/stdlib/src/erl_lint.erl b/lib/stdlib/src/erl_lint.erl
index 1118ff9210..10337b279e 100644
--- a/lib/stdlib/src/erl_lint.erl
+++ b/lib/stdlib/src/erl_lint.erl
@@ -2535,32 +2535,39 @@ type_def(Attr, Line, TypeName, ProtoType, Args, St0) ->
                 CheckType = {type, -1, product, [ProtoType|Args]},
                 check_type(CheckType, St#lint{types=NewDefs})
         end,
-    case (dict:is_key(TypePair, TypeDefs) orelse is_var_arity_type(TypeName)) of
-	true ->
-	    case is_default_type(TypePair) of
-		true  ->
-		    case is_newly_introduced_builtin_type(TypePair) of
-			%% allow some types just for bootstrapping
-			true ->
-			    Warn = {new_builtin_type, TypePair},
-			    St1 = add_warning(Line, Warn, St0),
+    case is_default_type(TypePair) of
+        true ->
+            case is_obsolete_builtin_type(TypePair) of
+                true -> StoreType(St0);
+                false ->
+                    case is_newly_introduced_builtin_type(TypePair) of
+                        %% allow some types just for bootstrapping
+                        true ->
+                            Warn = {new_builtin_type, TypePair},
+                            St1 = add_warning(Line, Warn, St0),
                             StoreType(St1);
-			false ->
-			    add_error(Line, {builtin_type, TypePair}, St0)
-		    end;
-	        false -> add_error(Line, {redefine_type, TypePair}, St0)
-	    end;
-	false ->
-            St1 = case
-                      Attr =:= opaque andalso
-                      is_underspecified(ProtoType, Arity)
-                  of
-                      true ->
-                          Warn = {underspecified_opaque, TypePair},
-                          add_warning(Line, Warn, St0);
-                      false -> St0
-                  end,
-            StoreType(St1)
+                        false ->
+                            add_error(Line, {builtin_type, TypePair}, St0)
+                    end
+            end;
+        false ->
+            case
+                dict:is_key(TypePair, TypeDefs)
+                orelse is_var_arity_type(TypeName)
+            of
+                true -> add_error(Line, {redefine_type, TypePair}, St0);
+                false ->
+                    St1 = case
+                              Attr =:= opaque andalso
+                              is_underspecified(ProtoType, Arity)
+                          of
+                              true ->
+                                  Warn = {underspecified_opaque, TypePair},
+                                  add_warning(Line, Warn, St0);
+                              false -> St0
+                          end,
+                    StoreType(St1)
+	    end
     end.
 
 is_underspecified({type,_,term,[]}, 0) -> true;
@@ -2785,19 +2792,15 @@ is_default_type(_) -> false.
 
 %% R13
 is_newly_introduced_builtin_type({arity, 0}) -> true;
-is_newly_introduced_builtin_type({array, 0}) -> true; % opaque
 is_newly_introduced_builtin_type({bitstring, 0}) -> true;
-is_newly_introduced_builtin_type({dict, 0}) -> true; % opaque
-is_newly_introduced_builtin_type({digraph, 0}) -> true; % opaque
-is_newly_introduced_builtin_type({gb_set, 0}) -> true; % opaque
-is_newly_introduced_builtin_type({gb_tree, 0}) -> true; % opaque
 is_newly_introduced_builtin_type({iodata, 0}) -> true;
-is_newly_introduced_builtin_type({queue, 0}) -> true; % opaque
-is_newly_introduced_builtin_type({set, 0}) -> true; % opaque
 %% R13B01
 is_newly_introduced_builtin_type({boolean, 0}) -> true;
 is_newly_introduced_builtin_type({Name, _}) when is_atom(Name) -> false.
 
+is_obsolete_builtin_type(TypePair) ->
+    obsolete_builtin_type(TypePair) =/= no.
+
 %% Obsolete in OTP 17.0.
 obsolete_builtin_type({array, 0}) ->
     {deprecated, {array, array, 1}, "OTP 18.0"};
@@ -2815,7 +2818,7 @@ obsolete_builtin_type({set, 0}) ->
     {deprecated, {sets, set, 1}, "OTP 18.0"};
 obsolete_builtin_type({tid, 0}) ->
     {deprecated, {ets, tid}, "OTP 18.0"};
-obsolete_builtin_type({Name, _}) when is_atom(Name) -> no.
+obsolete_builtin_type({Name, A}) when is_atom(Name), is_integer(A) -> no.
 
 %% spec_decl(Line, Fun, Types, State) -> State.
 
diff --git a/lib/stdlib/test/erl_lint_SUITE.erl b/lib/stdlib/test/erl_lint_SUITE.erl
index 67110f0ae2..00a92ff4bd 100644
--- a/lib/stdlib/test/erl_lint_SUITE.erl
+++ b/lib/stdlib/test/erl_lint_SUITE.erl
@@ -52,6 +52,7 @@
 	  guard/1, otp_4886/1, otp_4988/1, otp_5091/1, otp_5276/1, otp_5338/1,
 	  otp_5362/1, otp_5371/1, otp_7227/1, otp_5494/1, otp_5644/1, otp_5878/1,
 	  otp_5917/1, otp_6585/1, otp_6885/1, otp_10436/1, otp_11254/1,
+          otp_11772/1,
           export_all/1,
 	  bif_clash/1,
 	  behaviour_basic/1, behaviour_multiple/1,
@@ -86,7 +87,8 @@ all() ->
      unsized_binary_in_bin_gen_pattern,
      otp_4886, otp_4988, otp_5091, otp_5276, otp_5338,
      otp_5362, otp_5371, otp_7227, otp_5494, otp_5644,
-     otp_5878, otp_5917, otp_6585, otp_6885, otp_10436, otp_11254,export_all,
+     otp_5878, otp_5917, otp_6585, otp_6885, otp_10436, otp_11254,
+     otp_11772, export_all,
      bif_clash, behaviour_basic, behaviour_multiple,
      otp_7550, otp_8051, format_warn, {group, on_load},
      too_many_arguments, basic_errors, bin_syntax_errors, predef, maps].
@@ -2562,7 +2564,7 @@ otp_10436(Config) when is_list(Config) ->
     ok.
 
 otp_11254(doc) ->
-    "OTP-11254. Warnings for opaque types.";
+    "OTP-11254. M:F/A could crash the linter.";
 otp_11254(suite) -> [];
 otp_11254(Config) when is_list(Config) ->
     Ts = <<"-module(p2).
@@ -2575,6 +2577,44 @@ otp_11254(Config) when is_list(Config) ->
         run_test2(Config, Ts, []),
     ok.
 
+otp_11772(doc) ->
+    "OTP-11772. Reintroduce warnings for redefined builtin types.";
+otp_11772(suite) -> [];
+otp_11772(Config) when is_list(Config) ->
+    Ts = <<"
+            -module(newly).
+
+            -compile(export_all).
+
+            %% Built-in:
+            -type node() :: node().
+            -type mfa() :: tuple().
+            -type gb_tree() :: mfa(). % Allowed since Erlang/OTP 17.0
+            -type digraph() :: [_].   % Allowed since Erlang/OTP 17.0
+
+            %% \"Newly\" introduced:
+            -type arity() :: atom().
+            -type bitstring() :: list().
+            -type iodata() :: integer().
+            -type boolean() :: iodata().
+
+            -type t() :: arity() | bitstring() | iodata() | boolean() | mfa()
+                       | digraph() | gb_tree() | node().
+
+            -spec t() -> t().
+
+            t() ->
+                1.
+         ">>,
+    {error,[{7,erl_lint,{builtin_type,{node,0}}},
+                         {8,erl_lint,{builtin_type,{mfa,0}}}],
+                        [{13,erl_lint,{new_builtin_type,{arity,0}}},
+                         {14,erl_lint,{new_builtin_type,{bitstring,0}}},
+                         {15,erl_lint,{new_builtin_type,{iodata,0}}},
+                         {16,erl_lint,{new_builtin_type,{boolean,0}}}]} =
+        run_test2(Config, Ts, []),
+    ok.
+
 export_all(doc) ->
     "OTP-7392. Warning for export_all.";
 export_all(Config) when is_list(Config) ->