On 2017/10/10 6:25, Manuel López-Ibáñez wrote:
For what is worth, the color output of GCC comes originally from grep,
and grep does have code for colorizing in Windows:
http://git.savannah.gnu.org/cgit/grep.git/tree/lib
and there are significant differences with this patch. For once,
/* $TERM is not normally defined on DOS/Windows, so don't require
it for highlighting. But some programs, like Emacs, do define
it when running Grep as a subprocess, so make sure they don't
set TERM=dumb. */
char const *t = getenv ("TERM");
return ! (t && strcmp (t, "dumb") == 0);
and they don't need a custom fputs() because their strategy is slightly
different: They only override colorize_start (print_start_colorize) and
colorize_stop (print_end_colorize) and convert ANSI sequences to W32
sequences on the fly. Thus, we wouldn't need to touch pretty-printer.c
Since on *nix it is not when `colorize_start()` is called that the
terminal color is changed (it is when those ANSI escape codes are
delivered to the other peer which will translate them), and the string
passed to `fputs()` is free to deliver multiple escape codes, it is not
an option unless we output integral diagnostic messages using multiple
fputs()` calls.
For example,
```
test.c:3:9: warning: 'a' is used uninitialized in this function
[-Wuninitialized]
```
The words 'warning' and '-Wuninitialized' should be magenta, so there
are four ANSI escape codes (two to set the color and another two to
restore the color), and this line of text must be output using five
individual calls to the `fputs()` function (one for each segment with
the consistent color), which is not the case (this whole line of text is
delivered using a single call), so all five segments have to be all in
magenta or no color at all. This is not a solution.
and all changes will be restricted to diagnostic-color.c (which could be
split into -posix.c and -w32.c like grep does and be moved into
host-specific config/ subdir).
Even if the host-specific part is not done, I honestly think it is a
good idea to match grep's code as much as possible since we may want to
merge bugfixes between the two and eventually this code may end up in
gnulib. Moreover, if somebody else implemented color output for another
OS in grep, it would be very easy to transplant it to GCC (or viceversa)
if the API remains close.
Cheers,
Manuel.
--
Best regards,
LH_Mouse
