Reported by: Ludovic Brenta <ludovic <at> ludovic-brenta.org>
Date: Fri, 4 Oct 2019 13:33:01 UTC
Severity: minor
Found in version 26.1
Done: Stephen Leake <stephen_leake <at> stephe-leake.org>
Bug is archived. No further changes may be made.
Message #17 received at 37620 <at> debbugs.gnu.org (full text, mbox):
From: Stephen Leake <stephen_leake <at> stephe-leake.org> To: 37620 <at> debbugs.gnu.org Subject: 26.1; ada-mode 6.2.1 partial parsing occasionally hangs while moving point Date: Tue, 03 Mar 2020 14:29:14 -0800
[Message part 1 (text/plain, inline)]
There is a bug in error recovery that can cause the parser to hang; that may be the cause of this bug. Patch attached. -- -- Stephe
[patch.diff (text/x-patch, inline)]
--- a/wisitoken-parse-lr-mckenzie_recover-base.adb
+++ b/wisitoken-parse-lr-mckenzie_recover-base.adb
@@ -2,7 +2,7 @@
--
-- Base utilities for McKenzie_Recover
--
--- Copyright (C) 2018, 2019 Free Software Foundation, Inc.
+-- Copyright (C) 2018 - 2020 Free Software Foundation, Inc.
--
-- This library is free software; you can redistribute it and/or modify it
-- under terms of the GNU General Public License as published by the Free
@@ -30,49 +30,56 @@ package body WisiToken.Parse.LR.McKenzie_Recover.Base is
return Boolean
is
Done_Count : SAL.Base_Peek_Type := 0;
+ Skip : Boolean;
begin
-- Return True if all parsers are done, or if any parser has a config
-- available to check.
for P_Status of Parser_Status loop
+ Skip := False;
+
case P_Status.Recover_State is
when Active | Ready =>
if P_Status.Parser_State.Recover.Config_Heap.Count > 0 then
if P_Status.Parser_State.Recover.Check_Count - Check_Delta_Limit >= Min_Success_Check_Count then
-- fail; another parser succeeded, this one taking too long.
Done_Count := Done_Count + 1;
+ Skip := True;
elsif Total_Enqueue_Count + P_Status.Parser_State.Recover.Config_Full_Count >= Enqueue_Limit then
-- fail
Done_Count := Done_Count + 1;
+ Skip := True;
end if;
end if;
- case P_Status.Recover_State is
- when Active =>
- if P_Status.Parser_State.Recover.Config_Heap.Count > 0 then
- -- Still working
- return True;
- else
- if P_Status.Active_Workers = 0 then
- -- fail; no configs left to check.
- Done_Count := Done_Count + 1;
+ if not Skip then
+ case P_Status.Recover_State is
+ when Active =>
+ if P_Status.Parser_State.Recover.Config_Heap.Count > 0 then
+ -- Still working
+ return True;
+ else
+ if P_Status.Active_Workers = 0 then
+ -- fail; no configs left to check.
+ Done_Count := Done_Count + 1;
+ end if;
end if;
- end if;
- when Ready =>
- if P_Status.Parser_State.Recover.Config_Heap.Count > 0 and then
- P_Status.Parser_State.Recover.Config_Heap.Min_Key <= P_Status.Parser_State.Recover.Results.Min_Key
- then
- -- Still more to check.
- return True;
+ when Ready =>
+ if P_Status.Parser_State.Recover.Config_Heap.Count > 0 and then
+ P_Status.Parser_State.Recover.Config_Heap.Min_Key <= P_Status.Parser_State.Recover.Results.Min_Key
+ then
+ -- Still more to check.
+ return True;
- elsif P_Status.Active_Workers = 0 then
- Done_Count := Done_Count + 1;
- end if;
+ elsif P_Status.Active_Workers = 0 then
+ Done_Count := Done_Count + 1;
+ end if;
- when others =>
- null;
- end case;
+ when others =>
+ null;
+ end case;
+ end if;
when Success | Fail =>
Done_Count := Done_Count + 1;
@@ -135,6 +142,7 @@ package body WisiToken.Parse.LR.McKenzie_Recover.Base is
(Parsers, Parser_Status, Min_Success_Check_Count, Total_Enqueue_Count, Check_Delta_Limit, Enqueue_Limit)
is
Done_Count : SAL.Base_Peek_Type := 0;
+ Skip : Boolean;
Min_Cost : Integer := Integer'Last;
Min_Cost_Index : SAL.Base_Peek_Type;
@@ -168,6 +176,8 @@ package body WisiToken.Parse.LR.McKenzie_Recover.Base is
-- No task_id in outline trace messages, because they may appear in
-- .parse_good
for I in Parser_Status'Range loop
+ Skip := False;
+
declare
P_Status : Base.Parser_Status renames Parser_Status (I);
begin
@@ -186,6 +196,7 @@ package body WisiToken.Parse.LR.McKenzie_Recover.Base is
P_Status.Fail_Mode := Fail_Check_Delta;
Done_Count := Done_Count + 1;
+ Skip := True;
elsif Total_Enqueue_Count + P_Status.Parser_State.Recover.Config_Full_Count >= Enqueue_Limit then
if Trace_McKenzie > Outline then
@@ -200,48 +211,51 @@ package body WisiToken.Parse.LR.McKenzie_Recover.Base is
P_Status.Fail_Mode := Fail_Enqueue_Limit;
Done_Count := Done_Count + 1;
+ Skip := True;
end if;
end if;
- case P_Status.Recover_State is
- when Active =>
- if P_Status.Parser_State.Recover.Config_Heap.Count > 0 then
- if P_Status.Parser_State.Recover.Config_Heap.Min_Key < Min_Cost then
- Min_Cost := P_Status.Parser_State.Recover.Config_Heap.Min_Key;
- Min_Cost_Index := I;
- -- not done
- end if;
- else
- if P_Status.Active_Workers = 0 then
- -- No configs left to check (rarely happens with real languages).
- if Trace_McKenzie > Outline then
- Put_Line
- (Trace.all, P_Status.Parser_State.Label, "fail; no configs left", Task_ID => False);
+ if not Skip then
+ case P_Status.Recover_State is
+ when Active =>
+ if P_Status.Parser_State.Recover.Config_Heap.Count > 0 then
+ if P_Status.Parser_State.Recover.Config_Heap.Min_Key < Min_Cost then
+ Min_Cost := P_Status.Parser_State.Recover.Config_Heap.Min_Key;
+ Min_Cost_Index := I;
+ -- not done
+ end if;
+ else
+ if P_Status.Active_Workers = 0 then
+ -- No configs left to check (rarely happens with real languages).
+ if Trace_McKenzie > Outline then
+ Put_Line
+ (Trace.all, P_Status.Parser_State.Label, "fail; no configs left", Task_ID => False);
+ end if;
+ P_Status.Recover_State := Fail;
+ P_Status.Fail_Mode := Fail_No_Configs_Left;
+
+ Done_Count := Done_Count + 1;
end if;
- P_Status.Recover_State := Fail;
- P_Status.Fail_Mode := Fail_No_Configs_Left;
-
- Done_Count := Done_Count + 1;
end if;
- end if;
- when Ready =>
- if P_Status.Parser_State.Recover.Config_Heap.Count > 0 and then
- P_Status.Parser_State.Recover.Config_Heap.Min_Key <=
- P_Status.Parser_State.Recover.Results.Min_Key
- then
- -- Still more to check. We don't check Min_Cost here so this parser
- -- can finish quickly.
- Set_Outputs (I);
- return;
-
- elsif P_Status.Active_Workers = 0 then
- P_Status.Recover_State := Success;
- Done_Count := Done_Count + 1;
- end if;
- when others =>
- null;
- end case;
+ when Ready =>
+ if P_Status.Parser_State.Recover.Config_Heap.Count > 0 and then
+ P_Status.Parser_State.Recover.Config_Heap.Min_Key <=
+ P_Status.Parser_State.Recover.Results.Min_Key
+ then
+ -- Still more to check. We don't check Min_Cost here so this parser
+ -- can finish quickly.
+ Set_Outputs (I);
+ return;
+
+ elsif P_Status.Active_Workers = 0 then
+ P_Status.Recover_State := Success;
+ Done_Count := Done_Count + 1;
+ end if;
+ when others =>
+ null;
+ end case;
+ end if;
when Success | Fail =>
Done_Count := Done_Count + 1;
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