[Bug c++/102613] New: [C++23] P2246R1 - Character encoding of diagnostic text

[Bug c++/102613] New: [C++23] P2246R1 - Character encoding of diagnostic text

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102613

            Bug ID: 102613
           Summary: [C++23] P2246R1 - Character encoding of diagnostic
                    text
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: mpolacek at gcc dot gnu.org
  Target Milestone: ---

See https://wg21.link/p2246r1

This might be a noop, but we should include some tests probably.

[Bug c++/102613] [C++23] P2246R1 - Character encoding of diagnostic text

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102613

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jakub at gcc dot gnu.org,
                   |                            |jason at gcc dot gnu.org

--- Comment #1 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Is there anything we need to do here?
From what I can see, e.g. for static assertions which is one of the two changed
points
we reencode the message from -finput-charset= charset if supplied to UTF-8 and
then emit the UTF-8 chars to the terminal regardless of locale's charset
unobfuscated, so say given:
static_assert (false, "��c");
and -finput-charset=ISO-8859-1
00.C:1:16: error: static assertion failed: áæc
    1 | static_assert (false, "áæc");
      |                ^~~~~
is emitted, while without that -finput-charset= (i.e. when it is invalid
UTF-8), we emit
00.C:1:16: error: static assertion failed: ��c
    1 | static_assert (false, "��c");
      |                ^~~~~
On valid UTF-8 emoji:
static_assert (false, "😀");
we emit
01.C:1:16: error: static assertion failed: 😀
    1 | static_assert (false, "😀");
      |                ^~~~~
and with -finput-charset=ISO-8859-1
01.C:1:16: error: static assertion failed: ð
    1 | static_assert (false, "ð");
      |                ^~~~~
Not really sure what to do for our testsuite for this though, because while we
can use -finput-charset= in dg-options, we have no control on what the pseudo
terminal encoding actually is.

[Bug c++/102613] [C++23] P2246R1 - Character encoding of diagnostic text

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102613

--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Looking at what clang++ does, they emit
01.C:1:1: error: static_assert failed "\360\237\230\200"
etc. and don't really support -finput-charset=ISO-8859-1 etc.
(-finput-charset=utf-8 works).