Merge pull request #1783 from bjorng/bjorn/deprecate-get_stacktrace/OTP-14692

Deprecate erlang:get_stacktrace/1

3 files changed, 15 insertions, 128 deletions

diff --git a/lib/stdlib/src/erl_lint.erl b/lib/stdlib/src/erl_lint.erl
index 9a62d21d34..79dc6ce180 100644
--- a/lib/stdlib/src/erl_lint.erl
+++ b/lib/stdlib/src/erl_lint.erl
@@ -93,13 +93,6 @@ value_option(Flag, Default, On, OnVal, Off, OffVal, Opts) ->
          }).
 
 
-%% Are we outside or inside a catch or try/catch?
--type catch_scope() :: 'none'
-                     | 'after_old_catch'
-                     | 'after_try'
-                     | 'wrong_part_of_try'
-                     | 'try_catch'.
-
 %% Define the lint state record.
 %% 'called' and 'exports' contain {Line, {Function, Arity}},
 %% the other function collections contain {Function, Arity}.
@@ -144,9 +137,7 @@ value_option(Flag, Default, On, OnVal, Off, OffVal, Opts) ->
                    :: dict:dict(ta(), #typeinfo{}),
                exp_types=gb_sets:empty()        %Exported types
                    :: gb_sets:set(ta()),
-               in_try_head=false :: boolean(),  %In a try head.
-               catch_scope = none               %Inside/outside try or catch
-                   :: catch_scope()
+               in_try_head=false :: boolean()  %In a try head.
               }).
 
 -type lint_state() :: #lint{}.
@@ -233,15 +224,6 @@ format_error({redefine_old_bif_import,{F,A}}) ->
 format_error({redefine_bif_import,{F,A}}) ->
     io_lib:format("import directive overrides auto-imported BIF ~w/~w~n"
 		  " - use \"-compile({no_auto_import,[~w/~w]}).\" to resolve name clash", [F,A,F,A]);
-format_error({get_stacktrace,wrong_part_of_try}) ->
-    "erlang:get_stacktrace/0 used in the wrong part of 'try' expression. "
-        "(Use it in the block between 'catch' and 'end'.)";
-format_error({get_stacktrace,after_old_catch}) ->
-    "erlang:get_stacktrace/0 used following an old-style 'catch' "
-        "may stop working in a future release. (Use it inside 'try'.)";
-format_error({get_stacktrace,after_try}) ->
-    "erlang:get_stacktrace/0 used following a 'try' expression "
-        "may stop working in a future release. (Use it inside 'try'.)";
 format_error({deprecated, MFA, ReplacementMFA, Rel}) ->
     io_lib:format("~s is deprecated and will be removed in ~s; use ~s",
 		  [format_mfa(MFA), Rel, format_mfa(ReplacementMFA)]);
@@ -591,10 +573,7 @@ start(File, Opts) ->
 		      false, Opts)},
 	 {missing_spec_all,
 	  bool_option(warn_missing_spec_all, nowarn_missing_spec_all,
-		      false, Opts)},
-         {get_stacktrace,
-          bool_option(warn_get_stacktrace, nowarn_get_stacktrace,
-                      true, Opts)}
+		      false, Opts)}
 	],
     Enabled1 = [Category || {Category,true} <- Enabled0],
     Enabled = ordsets:from_list(Enabled1),
@@ -1426,7 +1405,7 @@ call_function(Line, F, A, #lint{usage=Usage0,called=Cd,func=Func,file=File}=St)
 %% function(Line, Name, Arity, Clauses, State) -> State.
 
 function(Line, Name, Arity, Cs, St0) ->
-    St1 = St0#lint{func={Name,Arity},catch_scope=none},
+    St1 = St0#lint{func={Name,Arity}},
     St2 = define_function(Line, Name, Arity, St1),
     clauses(Cs, St2).
 
@@ -2367,7 +2346,7 @@ expr({call,Line,F,As}, Vt, St0) ->
 expr({'try',Line,Es,Scs,Ccs,As}, Vt, St0) ->
     %% Currently, we don't allow any exports because later
     %% passes cannot handle exports in combination with 'after'.
-    {Evt0,St1} = exprs(Es, Vt, St0#lint{catch_scope=wrong_part_of_try}),
+    {Evt0,St1} = exprs(Es, Vt, St0),
     TryLine = {'try',Line},
     Uvt = vtunsafe(TryLine, Evt0, Vt),
     Evt1 = vtupdate(Uvt, Evt0),
@@ -2379,12 +2358,11 @@ expr({'try',Line,Es,Scs,Ccs,As}, Vt, St0) ->
     {Avt0,St} = exprs(As, vtupdate(Evt2, Vt), St2),
     Avt1 = vtupdate(vtunsafe(TryLine, Avt0, Vt), Avt0),
     Avt = vtmerge(Evt2, Avt1),
-    {Avt,St#lint{catch_scope=after_try}};
+    {Avt,St};
 expr({'catch',Line,E}, Vt, St0) ->
     %% No new variables added, flag new variables as unsafe.
     {Evt,St} = expr(E, Vt, St0),
-    {vtupdate(vtunsafe({'catch',Line}, Evt, Vt), Evt),
-     St#lint{catch_scope=after_old_catch}};
+    {vtupdate(vtunsafe({'catch',Line}, Evt, Vt), Evt),St};
 expr({match,_Line,P,E}, Vt, St0) ->
     {Evt,St1} = expr(E, Vt, St0),
     {Pvt,Bvt,St2} = pattern(P, vtupdate(Evt, Vt), St1),
@@ -3223,7 +3201,7 @@ is_module_dialyzer_option(Option) ->
 
 try_clauses(Scs, Ccs, In, Vt, St0) ->
     {Csvt0,St1} = icrt_clauses(Scs, Vt, St0),
-    St2 = St1#lint{catch_scope=try_catch,in_try_head=true},
+    St2 = St1#lint{in_try_head=true},
     {Csvt1,St3} = icrt_clauses(Ccs, Vt, St2),
     Csvt = Csvt0 ++ Csvt1,
     UpdVt = icrt_export(Csvt, Vt, In, St3),
@@ -3243,7 +3221,7 @@ icrt_clauses(Cs, In, Vt, St0) ->
 icrt_clauses(Cs, Vt, St) ->
     mapfoldl(fun (C, St0) -> icrt_clause(C, Vt, St0) end, St, Cs).
 
-icrt_clause({clause,_Line,H,G,B}, Vt0, #lint{catch_scope=Scope}=St0) ->
+icrt_clause({clause,_Line,H,G,B}, Vt0, St0) ->
     Vt1 = taint_stack_var(Vt0, H, St0),
     {Hvt,Binvt,St1} = head(H, Vt1, St0),
     Vt2 = vtupdate(Hvt, Binvt),
@@ -3251,7 +3229,7 @@ icrt_clause({clause,_Line,H,G,B}, Vt0, #lint{catch_scope=Scope}=St0) ->
     {Gvt,St2} = guard(G, vtupdate(Vt3, Vt0), St1#lint{in_try_head=false}),
     Vt4 = vtupdate(Gvt, Vt2),
     {Bvt,St3} = exprs(B, vtupdate(Vt4, Vt0), St2),
-    {vtupdate(Bvt, Vt4),St3#lint{catch_scope=Scope}}.
+    {vtupdate(Bvt, Vt4),St3}.
 
 taint_stack_var(Vt, Pat, #lint{in_try_head=true}) ->
     [{tuple,_,[_,_,{var,_,Stk}]}] = Pat,
@@ -3736,8 +3714,7 @@ has_wildcard_field([]) -> false.
 check_remote_function(Line, M, F, As, St0) ->
     St1 = deprecated_function(Line, M, F, As, St0),
     St2 = check_qlc_hrl(Line, M, F, As, St1),
-    St3 = check_get_stacktrace(Line, M, F, As, St2),
-    format_function(Line, M, F, As, St3).
+    format_function(Line, M, F, As, St2).
 
 %% check_qlc_hrl(Line, ModName, FuncName, [Arg], State) -> State
 %%  Add warning if qlc:q/1,2 has been called but qlc.hrl has not
@@ -3786,23 +3763,6 @@ deprecated_function(Line, M, F, As, St) ->
 	    St
     end.
 
-check_get_stacktrace(Line, erlang, get_stacktrace, [], St) ->
-    case St of
-        #lint{catch_scope=none} ->
-            St;
-        #lint{catch_scope=try_catch} ->
-            St;
-        #lint{catch_scope=Scope} ->
-            case is_warn_enabled(get_stacktrace, St) of
-                false ->
-                    St;
-                true ->
-                    add_warning(Line, {get_stacktrace,Scope}, St)
-            end
-    end;
-check_get_stacktrace(_, _, _, _, St) ->
-    St.
-
 -dialyzer({no_match, deprecated_type/5}).
 
 deprecated_type(L, M, N, As, St) ->
diff --git a/lib/stdlib/src/otp_internal.erl b/lib/stdlib/src/otp_internal.erl
index 5b488cc677..a17addcc42 100644
--- a/lib/stdlib/src/otp_internal.erl
+++ b/lib/stdlib/src/otp_internal.erl
@@ -604,6 +604,9 @@ obsolete_1(filename, find_src, 1) ->
 obsolete_1(filename, find_src, 2) ->
     {deprecated, "deprecated; use filelib:find_source/3 instead"};
 
+obsolete_1(erlang, get_stacktrace, 0) ->
+    {deprecated, "deprecated; use the new try/catch syntax for retrieving the stack backtrace"};
+
 %% Removed in OTP 20.
 
 obsolete_1(erlang, hash, 2) ->
diff --git a/lib/stdlib/test/erl_lint_SUITE.erl b/lib/stdlib/test/erl_lint_SUITE.erl
index e40f5e9a5d..f9ab83a120 100644
--- a/lib/stdlib/test/erl_lint_SUITE.erl
+++ b/lib/stdlib/test/erl_lint_SUITE.erl
@@ -66,7 +66,7 @@
          otp_11851/1,otp_11879/1,otp_13230/1,
          record_errors/1, otp_11879_cont/1,
          non_latin1_module/1, otp_14323/1,
-         get_stacktrace/1, stacktrace_syntax/1,
+         stacktrace_syntax/1,
          otp_14285/1, otp_14378/1]).
 
 suite() ->
@@ -88,7 +88,7 @@ all() ->
      maps, maps_type, maps_parallel_match,
      otp_11851, otp_11879, otp_13230,
      record_errors, otp_11879_cont, non_latin1_module, otp_14323,
-     get_stacktrace, stacktrace_syntax, otp_14285, otp_14378].
+     stacktrace_syntax, otp_14285, otp_14378].
 
 groups() -> 
     [{unused_vars_warn, [],
@@ -4055,82 +4055,6 @@ otp_14323(Config) ->
     [] = run(Config, Ts),
     ok.
 
-get_stacktrace(Config) ->
-    Ts = [{old_catch,
-           <<"t1() ->
-                  catch error(foo),
-                  erlang:get_stacktrace().
-           ">>,
-           [],
-           {warnings,[{3,erl_lint,{get_stacktrace,after_old_catch}}]}},
-          {nowarn_get_stacktrace,
-           <<"t1() ->
-                  catch error(foo),
-                  erlang:get_stacktrace().
-           ">>,
-           [nowarn_get_stacktrace],
-           []},
-          {try_catch,
-           <<"t1(X) ->
-                  try abs(X) of
-                    _ ->
-                      erlang:get_stacktrace()
-                  catch
-                      _:_ -> ok
-                  end.
-
-              t2() ->
-                  try error(foo)
-                  catch _:_ -> ok
-                  end,
-                  erlang:get_stacktrace().
-
-              t3() ->
-                  try error(foo)
-                  catch _:_ ->
-                    try error(bar)
-                    catch _:_ ->
-                      ok
-                    end,
-                    erlang:get_stacktrace()
-                  end.
-
-              no_warning(X) ->
-                  try
-                     abs(X)
-                  catch
-                     _:_ ->
-                       erlang:get_stacktrace()
-                  end.
-           ">>,
-           [],
-           {warnings,[{4,erl_lint,{get_stacktrace,wrong_part_of_try}},
-                      {13,erl_lint,{get_stacktrace,after_try}},
-                      {22,erl_lint,{get_stacktrace,after_try}}]}},
-          {multiple_catch_clauses,
-           <<"maybe_error(Arg) ->
-                try 5 / Arg
-                catch
-                    error:badarith ->
-                        _Stacktrace = erlang:get_stacktrace(),
-                        try io:nl()
-                        catch
-                            error:_ -> io:format('internal error')
-                        end;
-                    error:badarg ->
-                        _Stacktrace = erlang:get_stacktrace(),
-                        try io:format(qwe)
-                        catch
-                            error:_ -> io:format('internal error')
-                        end
-                end.
-             ">>,
-           [],
-           []}],
-
-    run(Config, Ts),
-    ok.
-
 stacktrace_syntax(Config) ->
     Ts = [{guard,
            <<"t1() ->