Introduce compiler option 'nowarn_deprecated_type'

The deprecation of the built-in types dict/0 and so on had as
side-effect that it was impossible to switch to dict:dict/2 and so on
without getting warnings either in the the previous release (R16B) or
the current one (17.0).

By including the attribute

    -compile(nowarn_deprecated_type).

in an Erlang source file warnings about deprecated types can be
avoided in 17.0.

The option can also be given as a compiler flag:

erlc +nowarn_deprecated_type file.erl

3 files changed, 36 insertions, 3 deletions

diff --git a/lib/compiler/doc/src/compile.xml b/lib/compiler/doc/src/compile.xml
index c66c8ea4bf..5fccdcdcb5 100644
--- a/lib/compiler/doc/src/compile.xml
+++ b/lib/compiler/doc/src/compile.xml
@@ -4,7 +4,7 @@
 <erlref>
   <header>
     <copyright>
-      <year>1996</year><year>2013</year>
+      <year>1996</year><year>2014</year>
       <holder>Ericsson AB. All Rights Reserved.</holder>
     </copyright>
     <legalnotice>
@@ -551,6 +551,14 @@ module.beam: module.erl \
               <c>{Module,Name,Arity}</c> or a list of such tuples.</p>
           </item>
 
+	  <tag><c>nowarn_deprecated_type</c></tag>
+          <item>
+            <p>Turns off warnings for uses of deprecated types. By
+	      default (<c>warn_deprecated_type</c>), warnings are
+	      emitted for every use of a type known by the compiler
+	      to be deprecated.</p>
+          </item>
+
 	  <tag><c>warn_obsolete_guard</c></tag>
           <item>
             <p>Causes warnings to be emitted for calls to old type
diff --git a/lib/stdlib/src/erl_lint.erl b/lib/stdlib/src/erl_lint.erl
index 603808328e..1fe0bd5896 100644
--- a/lib/stdlib/src/erl_lint.erl
+++ b/lib/stdlib/src/erl_lint.erl
@@ -508,6 +508,9 @@ start(File, Opts) ->
 	 {deprecated_function,
 	  bool_option(warn_deprecated_function, nowarn_deprecated_function,
 		      true, Opts)},
+	 {deprecated_type,
+	  bool_option(warn_deprecated_type, nowarn_deprecated_type,
+		      true, Opts)},
          {obsolete_guard,
           bool_option(warn_obsolete_guard, nowarn_obsolete_guard,
                       true, Opts)},
@@ -2646,7 +2649,8 @@ check_type({type, La, TypeName, Args}, SeenVars, St) ->
     St1 = case is_var_arity_type(TypeName) of
 	      true -> St;
 	      false ->
-                  Obsolete = obsolete_builtin_type(TypePair),
+                  Obsolete = (is_warn_enabled(deprecated_type, St)
+                              andalso obsolete_builtin_type(TypePair)),
                   IsObsolete =
                       case Obsolete of
                           {deprecated, Repl, _} when element(1, Repl) =/= Module ->
diff --git a/lib/stdlib/test/erl_lint_SUITE.erl b/lib/stdlib/test/erl_lint_SUITE.erl
index 68bea539a8..8754677466 100644
--- a/lib/stdlib/test/erl_lint_SUITE.erl
+++ b/lib/stdlib/test/erl_lint_SUITE.erl
@@ -3243,7 +3243,7 @@ bin_syntax_errors(Config) ->
     ok.
 
 predef(doc) ->
-    "Predefined types: array(), digraph(), and so on";
+    "OTP-10342: Predefined types: array(), digraph(), and so on";
 predef(suite) -> [];
 predef(Config) when is_list(Config) ->
     W = get_compilation_warnings(Config, "predef", []),
@@ -3258,6 +3258,27 @@ predef(Config) when is_list(Config) ->
      {37,erl_lint,{Tag,{queue,0},{queue,queue,1},"OTP 18.0"}},
      {42,erl_lint,{Tag,{set,0},{sets,set,1},"OTP 18.0"}},
      {47,erl_lint,{Tag,{tid,0},{ets,tid},"OTP 18.0"}}] = W2,
+    Ts = [{otp_10342_1,
+           <<"-compile(nowarn_deprecated_type).
+
+              -spec t(dict()) -> non_neg_integer().
+
+              t(D) ->
+                  erlang:phash2(D, 3000).
+             ">>,
+           {[nowarn_unused_function]},
+           []},
+         {otp_10342_2,
+           <<"-spec t(dict()) -> non_neg_integer().
+
+              t(D) ->
+                  erlang:phash2(D, 3000).
+             ">>,
+           {[nowarn_unused_function]},
+           {warnings,[{1,erl_lint,
+                       {deprecated_builtin_type,{dict,0},{dict,dict,2},
+                        "OTP 18.0"}}]}}],
+    [] = run(Config, Ts),
     ok.
 
 run(Config, Tests) ->