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Date: Thu, 26 May 2022 22:04:36 +0300
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From: Eli Zaretskii <eliz@gnu.org>
To: Tom Tromey <tromey@adacore.com>
Cc: gdb-patches@sourceware.org, jon.turney@dronecode.org.uk
In-Reply-To: <87zgj46xfm.fsf@tromey.com> (message from Tom Tromey on Thu, 26
 May 2022 11:00:45 -0600)
Subject: Re: [PATCH 1/9] Fix possible Cygwin build problem
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> From: Tom Tromey <tromey@adacore.com>
> Cc: Jon Turney <jon.turney@dronecode.org.uk>,  Eli Zaretskii <eliz@gnu.org>,
>   tromey@adacore.com
> Date: Thu, 26 May 2022 11:00:45 -0600
> 
> >>>>> "Eli" == Eli Zaretskii via Gdb-patches <gdb-patches@sourceware.org> writes:
> 
> Eli> __USEWIDE in native Windows programming assumes the use of wchar_t for
> Eli> character and character strings, something that GDB sources aren't
> Eli> equipped for doing, at least not easily.  AFAIK, Cygwin alleviates
> Eli> that by using UTF-8 encoded strings, but native Windows programming
> Eli> cannot (yet) do that safely enough on all supported Windows versions.
> 
> It looks like windows-nat.c defines __USEWIDE only for Cygwin, and then
> is careful to use the *W forms of various Windows APIs.  So maybe it
> works ok in practice?

I doubt it, in general, because GDB uses 'char *' for strings, and
those won't work in *W APIs without an explicit conversion to wchar_t.

However, I see only 2 calls to *W APIs in windows-nat.c, and they are
both under the __CYGWIN__ condition.  So I think we are good.

> Eli> As long as MinGW builds of GDB support only the so-called "ANSI"
> Eli> encoding (i.e. the current system codepage), there's no reason to use
> Eli> __USEWIDE in the MinGW build of GDB, and every reason not to use it.
> 
> Yeah, I think __USEWIDE is not used for mingw.  However I wonder if we
> could remove it for Cygwin as well... that would clean up some code.
> Not a huge amount, but every Cygwin divergence is a bit of a pain.

This will need a Cygwin expert, which I'm not.