From 16cb4f9c59142b4e82f1a2ccbcc904be7dfdee4c Mon Sep 17 00:00:00 2001
From: Hans Bolinder <hasse@erlang.org>
Date: Mon, 5 Feb 2018 12:32:07 +0100
Subject: stdlib: Do not call erlang:get_stacktrace()

---
 lib/stdlib/src/qlc.erl | 53 +++++++++++++++++++++++++-------------------------
 1 file changed, 26 insertions(+), 27 deletions(-)

(limited to 'lib/stdlib/src/qlc.erl')

diff --git a/lib/stdlib/src/qlc.erl b/lib/stdlib/src/qlc.erl
index f11f9d0a0b..3a66f6930b 100644
--- a/lib/stdlib/src/qlc.erl
+++ b/lib/stdlib/src/qlc.erl
@@ -301,11 +301,11 @@ eval(QH, Options) ->
                             post_funs(Post)
                         end
                 end
-            catch Term ->
-                case erlang:get_stacktrace() of
+            catch throw:Term:Stacktrace ->
+                case Stacktrace of
                     [?THROWN_ERROR | _] ->
                         Term;
-                    Stacktrace ->
+                    _ ->
                         erlang:raise(throw, Term, Stacktrace)
                 end
             end
@@ -359,11 +359,11 @@ fold(Fun, Acc0, QH, Options) ->
                             post_funs(Post)
                         end
                 end
-            catch Term ->
-                case erlang:get_stacktrace() of
+            catch throw:Term:Stacktrace ->
+                case Stacktrace of
                     [?THROWN_ERROR | _] ->
                         Term;
-                    Stacktrace ->
+                    _ ->
                         erlang:raise(throw, Term, Stacktrace)
                 end
             end
@@ -457,11 +457,11 @@ info(QH, Options) ->
                     debug -> % Not documented. Intended for testing only.
                         Info
                 end
-            catch Term ->
-                case erlang:get_stacktrace() of
+            catch throw:Term:Stacktrace ->
+                case Stacktrace of
                     [?THROWN_ERROR | _] ->
                         Term;
-                    Stacktrace ->
+                    _ ->
                         erlang:raise(throw, Term, Stacktrace)
                 end
             end
@@ -1056,9 +1056,9 @@ cursor_process(H, GUnique, GCache, TmpDir, SpawnOptions, MaxList, TmpUsage) ->
                          Prep = prepare_qlc(H, not_a_list, GUnique, GCache, 
                                             TmpDir, MaxList, TmpUsage),
                          setup_qlc(Prep, Setup)
-                     catch Class:Reason ->
-                           Parent ! {self(), {caught, Class, Reason, 
-                                     erlang:get_stacktrace()}},
+                     catch Class:Reason:Stacktrace ->
+                           Parent ! {self(),
+                                     {caught, Class, Reason, Stacktrace}},
                            exit(normal)
                      end,
                  Parent ! {self(), ok},
@@ -1075,8 +1075,8 @@ parent_fun(Pid, Parent) ->
         {TPid, {parent_fun, Fun}} ->
             V = try 
                     {value, Fun()}
-                catch Class:Reason ->
-                    {parent_fun_caught, Class, Reason, erlang:get_stacktrace()}
+                catch Class:Reason:Stacktrace ->
+                    {parent_fun_caught, Class, Reason, Stacktrace}
             end,
             TPid ! {Parent, V},
             parent_fun(Pid, Parent);
@@ -1101,9 +1101,9 @@ reply(Parent, MonRef, Post, Cont) ->
                         throw_error(Cont)
                 end
             catch 
-                Class:Reason ->
+                Class:Reason:Stacktrace ->
                    post_funs(Post),
-                   Message = {caught, Class, Reason, erlang:get_stacktrace()},
+                   Message = {caught, Class, Reason, Stacktrace},
                    Parent ! {self(), Message},
                    exit(normal)
             end,
@@ -1392,9 +1392,8 @@ next_loop(Pid, L, N) when N =/= 0 ->
         {caught, throw, Error, [?THROWN_ERROR | _]} ->
             Error;
         {caught, Class, Reason, Stacktrace} ->
-            CurrentStacktrace = try erlang:error(foo)
-                                catch error:_ -> erlang:get_stacktrace()
-                                end,
+            {current_stacktrace, CurrentStacktrace} =
+                erlang:process_info(self(), current_stacktrace),
             erlang:raise(Class, Reason, Stacktrace ++ CurrentStacktrace);
         error ->
             erlang:error({qlc_cursor_pid_no_longer_exists, Pid})
@@ -2627,9 +2626,9 @@ table_handle(#qlc_table{trav_fun = TraverseFun, trav_MS = TravMS,
             Parent =:= self() ->
                 try
                     ParentFun() 
-                catch Class:Reason ->
+                catch Class:Reason:Stacktrace ->
                     post_funs(Post),
-                    erlang:raise(Class, Reason, erlang:get_stacktrace())
+                    erlang:raise(Class, Reason, Stacktrace)
                 end;
             true ->
                 case monitor_request(Parent, {parent_fun, ParentFun}) of
@@ -3033,9 +3032,9 @@ file_sort_handle(H, Kp, SortOptions, TmpDir, Compressed, Post, LocalPost) ->
         {terms, BTerms} ->
             try 
                 {[binary_to_term(B) || B <- BTerms], Post, LocalPost}
-            catch Class:Reason ->
+            catch Class:Reason:Stacktrace ->
                 post_funs(Post),
-                erlang:raise(Class, Reason, erlang:get_stacktrace())
+                erlang:raise(Class, Reason, Stacktrace)
             end
     end.
 
@@ -3045,9 +3044,9 @@ do_sort(In, Out, Sort, SortOptions, Post) ->
             {error, Reason} -> throw_reason(Reason);
             Reply -> Reply
         end
-    catch Class:Term ->
+    catch Class:Term:Stacktrace ->
         post_funs(Post),
-        erlang:raise(Class, Term, erlang:get_stacktrace())
+        erlang:raise(Class, Term, Stacktrace)
     end.
 
 do_sort(In, Out, sort, SortOptions) ->
@@ -3797,9 +3796,9 @@ call(undefined, _Arg, Default, _Post) ->
 call(Fun, Arg, _Default, Post) ->
     try
         Fun(Arg) 
-    catch Class:Reason ->
+    catch Class:Reason:Stacktrace ->
         post_funs(Post),
-        erlang:raise(Class, Reason, erlang:get_stacktrace())
+        erlang:raise(Class, Reason, Stacktrace)
     end.
 
 grd(undefined, _Arg) ->
-- 
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