Re: Providing more precise "excess errors" message in DejaGnu

On 28/08/2025 15:01, Iain Sandoe wrote:
> 
> 
>> On 28 Aug 2025, at 14:36, Jeff Law via Gcc <[email protected]> wrote:
>>
>>
>>
>> On 8/28/25 5:42 AM, Richard Biener via Gcc wrote:
>>> On Thu, Aug 28, 2025 at 1:12 PM Rainer Orth via Gcc <[email protected]> wrote:
>>>>
>>>> Hi Sam,
>>>>
>>>>> When a test fails with 'excess errors', there's often only one actual
>>>>> error (an excess "(error|warning|note):") and it'd be nice to not have
>>>>> to dig in the .log files to fish that out.
>>>>
>>>> I think such a move would be a bad mistake.  Consider ICEs where you
>>>> have something like
>>>>
>>>> FAIL: gcc.c-torture/compile/pr35318.c   -O0  (test for excess errors)
>>>> Excess errors:
>>>> /vol/gcc/src/hg/master/local/gcc/testsuite/gcc.c-torture/compile/pr35318.c:9:1: error: unrecognizable insn:
>>>> (insn 13 25 26 2 (parallel [
>>>>             (set (reg:DF 10 %o2 [orig:112 x ] [112])
>>>>                 (asm_operands/v:DF ("") ("=r,r") 0 [
>>>>                         (reg:SI 11 %o3 [orig:112 x+4 ] [112])
>>>>                         (mem/c:DF (plus:SI (reg/f:SI 30 %fp)
>>>>                                 (const_int -24 [0xffffffffffffffe8])) [3 %sfp+-24 S8 A64])
>>>> [and many more lines...]
>>>>
>>>> This would clutter the output beyond recognition, especially if this is
>>>> a torture test which is run at several optimization options.
>>>>
>>>> Excess errors, like all others, always require further investigation.
>>>> In my experience, digging the full error messages from the .log files is
>>>> usually the smallest part of that.  You often even have to rerun the
>>>> compilation manually to also get the parts that are filtered out by the
>>>> prune procs.
>>> I find the classification this would provide useful, like I like the
>>> (internal compiler error) classification we already have.  I would
>>> of course not duplicate all of th eabove message but only
>>> '(unrecognizable insn)' in the above case.
>> It's not the only consideration, but keep in mind that such output is not stable and will cause some headaches with scripting that compares two summary files.
> 
> This is something that I think we want to tackle anyway ..
>>
>> Even with the bit of instability to the line number in the ICE message, I do find the ICE classification useful as well.
> 
> … the classification is useful, but the false positive “new fail / old fail went away” pairs are a real nuiscance .. hopefully we can have some brainstorming @cauldron about ways to deal with this (e.g. fuzzy matching or some smart way to discard the twinkling line numbers).
> 

Well really, the compare-tests script should report duplicate results as a problem as well, since 

PASS: abcd
...
PASS: abcd

is just a dup pass/fail waiting to happen.


R.

> Iain
> 
> 
> 
>>
>> Jeff
>