Re: [PATCH] Add --with-diagnostics-urls configuration option and GCC_URLS env var

[王昊然 <msl0000023508@gmail.com>]

I think this is good idea since it is consistent with env var
GCC_COLORS -- the color support will be disabled even with
-fdiagnostics-color=always, if GCC_COLORS is set to empty.
And I has experienced more serious problem when I ssh(1) to the remote
machine from a even older terminal, GNOME Terminal 2.30.2. The
terminal bells made noticeable delays; The whole terminal window would
hang for several seconds when gcc(1) emits too many warnings in at a
time...

2019-12-20 4:48 GMT+08:00, Jakub Jelinek <jakub@redhat.com>:
> On Thu, Dec 19, 2019 at 03:24:19PM -0500, David Malcolm wrote:
>> Currently -fdiagnostics-urls defaults to "auto" and this works
>> (e.g. for recent gnome-terminal, and is gracefully discarded by
>> konsole5), but there have been reports of incompatibilities of the
>> feature with various other terminals.
>>
>> This patch adds a configuration option to change this default, based
>> on Jakub's analogous change to -fdiagnostics-color (r217540).  One
>> possible configure-time option is --with-diagnostics-urls=auto-if-env,
>> which adds support for a GCC_URLS environment variable to control
>> the default (again by analogy with the --with-diagnostics-color
>> configure-time support for changing -fdiagnostics-color).
>
> I think it would be better to have GCC_URLS env var to be be more
> consistent
> with GCC_COLORS, so yes, have the never,auto,auto-if-env,always
> configure possibilities like for colors and for auto-if-env don't print
> URLS if the env var is not present, but on top of that, parse also the
> value
> of the env var like parse_gcc_colors does, and have a way to disable urls
> even with -fdiagnostics-urls=always (like GCC_COLORS= disables colors),
> and perhaps use the env var to select between the ST and BEL terminator
> as apparently some terminals like one or the other more.
> So perhaps accept GCC_URLS= and GCC_URLS=no as disabling, GCC_URLS=bel
> as the (default) case for BEL termination and GCC_URLS=st for the ST
> termination?
> E.g. have a way even for a compiler configured that it will work with new
> terminals most of them time and thus --with-diagnostics-urls=always that
> if somebody sshs to some machine from some old host, GCC_URLS=no (or none?)
> can be still used to disable it, without the need to tweak build system to
> inject there some flags.
>
>> Successfully bootstrapped & regrtested on x86_64-pc-linux-gnu; I
>> tested the --with-diagnostics-urls=auto-if-env and GCC_URLS behavior
>> manually.
>>
>> Jakub: does this look sane to you?  (given that this is heavily based
>> on your 2014 patches for --with-diagnostics-color).
>
> 	Jakub
>
>