Re: [PING] Re: [Committed] [PATCH 2/4] (v4) On-demand locations within string-literals

[Jeff Law <jeffreyalaw@gmail.com>]

On 9/10/2021 1:48 AM, Thomas Schwinge wrote:
> Hi!
>
> Ping.  My patches again attached, for easy reference.
>
>
> Grüße
>   Thomas
>
>
> On 2021-09-03T18:33:37+0200, I wrote:
>> Hi!
>>
>> On 2021-09-02T21:09:54+0200, I wrote:
>>> On 2021-09-02T15:59:14+0200, I wrote:
>>>> On 2016-08-05T14:16:58-0400, David Malcolm <dmalcolm@redhat.com> wrote:
>>>>> Committed to trunk as r239175; I'm attaching the final version of the
>>>>> patch for reference.
>>>> David, you've added here 'gcc/input.h:struct location_hash' (see quoted
>>>> below), which will be useful elsewhere, so:
>>>>
>>>>> --- a/gcc/input.c
>>>>> +++ b/gcc/input.c
>>>>> +/* Internal function.  Canonicalize LOC into a form suitable for
>>>>> +   use as a key within the database, stripping away macro expansion,
>>>>> +   ad-hoc information, and range information, using the location of
>>>>> +   the start of LOC within an ordinary linemap.  */
>>>>> +
>>>>> +location_t
>>>>> +string_concat_db::get_key_loc (location_t loc)
>>>>> +{
>>>>> +  loc = linemap_resolve_location (line_table, loc, LRK_SPELLING_LOCATION,
>>>>> +                             NULL);
>>>>> +
>>>>> +  loc = get_range_from_loc (line_table, loc).m_start;
>>>>> +
>>>>> +  return loc;
>>>>> +}
>>>> OK to push the attached
>>>> "Harden 'gcc/input.c:string_concat_db::get_key_loc'"?  (This fell out of
>>>> my analysis for development work elsewhere.)
>>> My suggested patch was:
>>>
>>>      --- a/gcc/input.c
>>>      +++ b/gcc/input.c
>>>      @@ -1483,6 +1483,9 @@ string_concat_db::get_key_loc (location_t loc)
>>>
>>>         loc = get_range_from_loc (line_table, loc).m_start;
>>>
>>>      +  /* Ascertain that 'loc' is valid as a key in 'm_table'.  */
>>>      +  gcc_checking_assert (!RESERVED_LOCATION_P (loc));
>>>      +
>>>         return loc;
>>>       }
>>>
>>> Uh, I should've looked at the correct test logs...  This change actually
>>> does regress 'c-c++-common/substring-location-PR-87721.c' and
>>> 'gcc.dg/plugin/diagnostic-test-string-literals-1.c': for these, we do see
>>> 'BUILTINS_LOCATION' (via 'string_concat_db::record_string_concatenation').
>>> Unless someone tell me that's unexpected (I'm completely lost in this
>>> code...)
>> I think I convinced myself that the current code doesn't have stable
>> behavior, so...
>>
>>> I shall change/generalize my changes to provide both a
>>> 'location_hash' only using 'UNKNOWN_LOCATION' as a spare value for
>>> 'Empty' (as currently used here) and another variant additionally using
>>> 'BUILTINS_LOCATION' as spare value for 'Deleted'.
>> ... I didn't do this, but instead would like to push the attached
>> "Don't record string concatenation data for 'RESERVED_LOCATION_P'"
>> (replacing "Harden 'gcc/input.c:string_concat_db::get_key_loc'" as
>> originally proposed).  OK?
>>
>>
>> ... and then re:
>>
>>>>> --- a/gcc/input.h
>>>>> +++ b/gcc/input.h
>>>>> +struct location_hash : int_hash <location_t, UNKNOWN_LOCATION> { };
>>>>> +
>>>>> +class GTY(()) string_concat_db
>>>>> +{
>>>>> +[...]
>>>>> +  hash_map <location_hash, string_concat *> *m_table;
>>>>> +};
>>>> OK to push the attached
>>>> "Generalize 'gcc/input.h:struct location_hash'"?
>> Attached again.
>>
>>
>> Grüße
>>   Thomas
>
> -----------------
> Siemens Electronic Design Automation GmbH; Anschrift: Arnulfstraße 201, 80634 München; Gesellschaft mit beschränkter Haftung; Geschäftsführer: Thomas Heurung, Frank Thürauf; Sitz der Gesellschaft: München; Registergericht München, HRB 106955
>
> 0001-Don-t-record-string-concatenation-data-for-RESERVED_.patch
>
>  From 9f1066fcb770397d6e791aa0594f067a755e2ed6 Mon Sep 17 00:00:00 2001
> From: Thomas Schwinge <thomas@codesourcery.com>
> Date: Fri, 3 Sep 2021 18:25:10 +0200
> Subject: [PATCH] Don't record string concatenation data for
>   'RESERVED_LOCATION_P'
>
> 'RESERVED_LOCATION_P' means 'UNKNOWN_LOCATION' or 'BUILTINS_LOCATION.
> We're using 'UNKNOWN_LOCATION' as a spare value for 'Empty', so should
> ascertain that we don't use it as a key additionally.  Similarly for
> 'BUILTINS_LOCATION' that we'd later like to use as a spare value for
> 'Deleted'.
>
> As discussed in the source code comment added, for these we didn't have
> stable behavior anyway.
>
> Follow-up to r239175 (commit 88fa5555a309e5d6c6171b957daaf2f800920869)
> "On-demand locations within string-literals".
>
> 	gcc/
> 	* input.c (string_concat_db::record_string_concatenation)
> 	(string_concat_db::get_string_concatenation): Skip for
> 	'RESERVED_LOCATION_P'.
> 	gcc/testsuite/
> 	* gcc.dg/plugin/diagnostic-test-string-literals-1.c: Adjust
> 	expected error diagnostics.
OK
jeff