From: Martin Sebor <msebor@gmail.com>
To: gcc-patches <gcc-patches@gcc.gnu.org>, Jason Merrill <jason@redhat.com>
Subject: [PING 2][PATCH] correct handling of indices into arrays with elements larger than 1 (PR c++/96511)
Date: Fri, 28 Aug 2020 09:42:52 -0600 [thread overview]
Message-ID: <5700f4c4-9bba-3997-c424-2c9ab522a454@gmail.com> (raw)
In-Reply-To: <c077c515-6cf2-43f8-3785-78905a6962f6@gmail.com>
Ping: https://gcc.gnu.org/pipermail/gcc-patches/2020-August/551783.html
On 8/19/20 9:00 AM, Martin Sebor wrote:
> Ping: https://gcc.gnu.org/pipermail/gcc-patches/2020-August/551783.html
>
> On 8/11/20 10:19 AM, Martin Sebor wrote:
>> -Wplacement-new handles array indices and pointer offsets the same:
>> by adjusting them by the size of the element. That's correct for
>> the latter but wrong for the former, causing false positives when
>> the element size is greater than one.
>>
>> In addition, the warning doesn't even attempt to handle arrays of
>> arrays. I'm not sure if I forgot or if I simply didn't think of
>> it.
>>
>> The attached patch corrects these oversights by replacing most
>> of the -Wplacement-new code with a call to compute_objsize which
>> handles all this correctly (plus more), and is also better tested.
>> But even compute_objsize has bugs: it trips up while converting
>> wide_int to offset_int for some pointer offset ranges. Since
>> handling the C++ IL required changes in this area the patch also
>> fixes that.
>>
>> For review purposes, the patch affects just the middle end.
>> The C++ diff pretty much just removes code from the front end.
>>
>> Tested on x86_64-linux plus by building the latest Glibc and
>> confirming no new warnings.
>>
>> Martin
>
next prev parent reply other threads:[~2020-08-28 15:42 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-11 16:19 [PATCH] " Martin Sebor
2020-08-19 15:00 ` [PING][PATCH] " Martin Sebor
2020-08-28 15:42 ` Martin Sebor [this message]
2020-09-01 19:22 ` [PATCH] " Jason Merrill
2020-09-03 18:44 ` Martin Sebor
2020-09-04 17:14 ` Jason Merrill
2020-09-14 22:01 ` Martin Sebor
2020-09-21 21:17 ` [PING][PATCH] " Martin Sebor
2020-09-22 20:05 ` Martin Sebor
2020-09-26 5:17 ` Jason Merrill
2020-09-28 22:01 ` Martin Sebor
2020-10-05 16:37 ` Martin Sebor
2020-10-07 14:26 ` Jason Merrill
2020-10-07 14:42 ` Martin Sebor
2020-10-07 15:07 ` Jason Merrill
2020-10-07 15:19 ` Martin Sebor
2020-10-07 19:28 ` Jason Merrill
2020-10-07 20:11 ` Martin Sebor
2020-10-07 21:01 ` Jason Merrill
2020-10-08 19:18 ` Martin Sebor
2020-10-08 19:40 ` Jason Merrill
2020-10-09 14:51 ` Martin Sebor
2020-10-09 15:13 ` Jason Merrill
2020-10-11 22:45 ` Martin Sebor
2020-10-12 3:44 ` Jason Merrill
2020-10-12 15:21 ` Martin Sebor
2020-10-13 9:46 ` Christophe Lyon
2020-10-13 16:59 ` Martin Sebor
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