Hi!

On 2020-11-30T12:28:31-0700, Jeff Law via Gcc-patches <gcc-patches@gcc.gnu.org> wrote:
> On 11/24/20 2:53 AM, Thomas Schwinge wrote:
>> On 2020-11-06T10:26:46+0100, I wrote:
>>> On 2018-09-25T16:00:14-0400, David Malcolm <dmalcolm@redhat.com> wrote:
>>>> As noted at Cauldron, dumpfile.c currently emits "note: " for all kinds
>>>> of dump message, so that (after filtering) there's no distinction between
>>>> MSG_OPTIMIZED_LOCATIONS vs MSG_NOTE vs MSG_MISSED_OPTIMIZATION in the
>>>> textual output.
>>>>
>>>> This patch changes dumpfile.c so that the "note: " varies to show
>>>> which MSG_* was used, with the string prefix matching that used for
>>>> filtering in -fopt-info, hence e.g.
>>>>   directive_unroll_3.f90:24:0: optimized: loop unrolled 7 times
>>>> and:
>>>>   pr19210-1.c:24:3: missed: missed loop optimization: niters analysis ends up with assumptions.
>>> (However, 'MSG_NOTE'/'note: ' also still remains used for "general
>>> optimization info".)

Well, and of course, 'note: ' prefixes have also "forever" been used for
'inform' etc. diagnostics; so my change here much more relates to
'dg-message', 'dg-warning', 'dg-error' rather than 'dg-optimized',
'dg-missed'.  ;-)

>>>> The patch adds "dg-optimized" and "dg-missed" directives
>>>> --- a/gcc/testsuite/lib/gcc-dg.exp
>>>> +++ b/gcc/testsuite/lib/gcc-dg.exp
>>>> +# Handle output from -fopt-info for MSG_OPTIMIZED_LOCATIONS:
>>>> +# a successful optimization.
>>>> +
>>>> +proc dg-optimized { args } {
>>>> +    # Make this variable available here and to the saved proc.
>>>> +    upvar dg-messages dg-messages
>>>> +
>>>> +    process-message saved-dg-error "optimized: " "$args"
>>>> +}
>>>> +
>>>> +# Handle output from -fopt-info for MSG_MISSED_OPTIMIZATION:
>>>> +# a missed optimization.
>>>> +
>>>> +proc dg-missed { args } {
>>>> +    # Make this variable available here and to the saved proc.
>>>> +    upvar dg-messages dg-messages
>>>> +
>>>> +    process-message saved-dg-error "missed: " "$args"
>>>> +}
>>>> +
>>>
>>> Next to these, I'm proposing to add 'dg-note', see attached "[WIP] Add
>>> 'dg-note' next to 'dg-optimized'", which may be used instead of generic
>>> 'dg-message' (which in current uses in testcases often doesn't scan for
>>> the 'note: ' prefix, by the way).
>>>
>>> The proposed 'dg-note' has the additional property that "if dg-note is
>>> used once, [notes] must *all* be handled explicitly".  The rationale is
>>> that either you're not interested in notes at all (default behavior of
>>> pruning all notes), but often, when you're interested in one note, you're
>>> in fact interested in all notes, and especially interested if
>>> *additional* notes appear over time, as GCC evolves.  It seemed somewhat
>>> useful, but I'm not insisting on coupling the disabling of notes pruning
>>> on 'dg-note' usage, so if anyone feels strongly about that, please speak
>>> up.

(No comments received.)

> I think this is generally fine with the proper doc updates.

ACK, thanks; done.

>>> TODO 'gcc/testsuite/lib/lto.exp' change necessary/desirable?
>>>
>>> The latter got added in commit 824721f0905478ebc39e6a295cc8e95c22fa9d17
>>> "lto, testsuite: Fix ICE in -Wodr (PR lto/83121)".  David, do you happen
>>> to have an opinion on that one?

> I wouldn't
> think we'd want/need to treat LTO differently, so I'm not so sure about
> that specific hunk.

As it should turn out -- of course ;-) -- LTO does need some special
care; added, plus a few testcases adapted, too.

I've pushed "Add 'dg-note', 'dg-lto-note'" to master branch in commit
03eb779141a29f96600cd46904b88a33c4b49a66, see attached.


Grüße
 Thomas


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