From: Alec Teal <a.teal@warwick.ac.uk>
To: Jonathan Wakely <jwakely.gcc@gmail.com>
Cc: gcc-help <gcc-help@gcc.gnu.org>
Subject: Re: [X-POST] Alignas broken when used with constexpr array data member for structure
Date: Tue, 09 Jan 2018 13:49:00 -0000 [thread overview]
Message-ID: <9fca020d-371e-d14d-521a-5b3798c052c7@warwick.ac.uk> (raw)
In-Reply-To: <CAH6eHdRrrcG2TsLqxsrJZTnHPQa8BjAF1cS7C56p_hsZ02Qbbw@mail.gmail.com>
More specific please, there's a lot in here.
For example I had a look in constexpr - seems like a good place to
start! 7k lines; things may have moved.
It seems I might have been wrong, I need more than a directory!
I'm currently trying to set a breakpoint where errors are emitted (and
hopefully find something on the stack, even if it's a function doing the
passes!) - it's hard to find!
Usually I'd take more of a guess but this bug means I'm very far off the
mark with the implementation.
Alec
On 09/01/18 13:40, Jonathan Wakely wrote:
> And I've now told you both on IRC and in reply to your original email,
> the directory is gcc/cp
>
> On 9 January 2018 at 13:39, Alec Teal <a.teal@warwick.ac.uk> wrote:
>> Per recommendation asking on GCC help
>>
>>
>>
>> -------- Forwarded Message --------
>> Subject: Alignas broken when used with constexpr array data member
>> for structure
>> Date: Tue, 9 Jan 2018 13:15:37 +0000
>> From: Alec Teal <a.teal@warwick.ac.uk>
>> To: gcc@gcc.gnu.org <gcc@gcc.gnu.org>
>>
>>
>>
>> [This sender failed our fraud detection checks and may not be who they
>> appear to be. Learn about spoofing at http://aka.ms/LearnAboutSpoofing]
>>
>>
>> Hi there,
>>
>> In GCC 4.8.4 I have something like the following:
>>
>> constexpr int x = 5;
>>
>> constexpr int y = 4;
>>
>> struct alignas(y) my_data_block {
>>
>> char data[x];
>>
>> };
>>
>>
>> And it causes some weird errors to the tune of "size of array ‘data’ is
>> not an integral constant-expression" in the presence of the alignas
>>
>> This is a pretty nasty bug and means it's not implemented as I thought.
>> I don't know the front-ends (but I do actually know GIMPLE-low and below
>> quite well, love the pattern matching) and I'd like to dig more, it's
>> almost certainly fixed - this is just for personal curiosity.
>>
>> Where would I look? A 1 line reply with a directory would be a great
>> start; even if it's just a guess.
>>
>> I did ask in #gcc on freenode - it didn't go so well, sorry to ping you
>> all for this.
>>
>>
>> Alec
>>
next prev parent reply other threads:[~2018-01-09 13:49 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <2182301d-14b8-287d-bf6b-d9ed22e34726@warwick.ac.uk>
2018-01-09 13:39 ` Fwd: " Alec Teal
2018-01-09 13:41 ` Jonathan Wakely
2018-01-09 13:49 ` Alec Teal [this message]
2018-01-09 13:56 ` Jonathan Wakely
2018-01-09 14:04 ` Alec Teal
2018-01-09 14:06 ` Jonathan Wakely
2018-01-09 14:26 ` Mason
2018-01-09 14:29 ` Jonathan Wakely
2018-01-12 16:50 ` Alec Teal
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