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From: "ppalka at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c++/82877] negative array index accepted in a pointer difference expression in constexpr context
Date: Fri, 29 Jan 2021 17:43:52 +0000	[thread overview]
Message-ID: <bug-82877-4-SwF9KBNw5e@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-82877-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82877

Patrick Palka <ppalka at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |ppalka at gcc dot gnu.org

--- Comment #3 from Patrick Palka <ppalka at gcc dot gnu.org> ---
Looks we correctly reject the testcase starting with GCC 9.1 (r9-6136):

<source>:9:21:   in 'constexpr' expansion of 'f()'
<source>:9:22: error: array subscript value '-1' is outside the bounds of array
type 'int [1]'
    9 | constexpr int i = f ();
      |                      ^

Starting with GCC 10.1, the diagnostic also points to the correct line:

source>:9:21:   in 'constexpr' expansion of 'f()'
<source>:6:27: error: array subscript value '-1' is outside the bounds of array
type 'int [1]'
    6 |   return &s.a[0] - &s.a[-1];   // undefined, should be rejected
      |                     ~~~~~~^

       reply	other threads:[~2021-01-29 17:43 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <bug-82877-4@http.gcc.gnu.org/bugzilla/>
2021-01-29 17:43 ` ppalka at gcc dot gnu.org [this message]
2021-09-12 19:01 ` johelegp at gmail dot com
2022-09-26  9:29 ` redi at gcc dot gnu.org

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