Re: [PATCH] diagnostics: Fix up selftests with $COLUMNS < 42 [PR108973]

[David Malcolm <dmalcolm@redhat.com>]

On Fri, 2023-03-03 at 10:35 +0100, Jakub Jelinek wrote:
> Hi!
> 
> As mentioned in the PR, GCC's diagnostics self-tests fail if $COLUMNS
> < 42.
> Guarding each self-test with if (get_terminal_width () > 41) or
> similar
> would be a maintainance nightmare (PR has a patch to do so without
> reformatting to make it work for $COLUMNS in [30, 41] inclusive, but
> I'm afraid going down to $COLUMNS 1 would mean marking everything).
> Furthermore, the self-tests don't really emit stuff to the terminal,
> but into a buffer, so using get_terminal_width () for it seems
> inappropriate.  The following patch makes sure
> test_diagnostic_context
> constructor uses at least 80 columns wide caret max width, of course
> some tests override it already if they want to test for behavior in
> narrower
> cases.
> 
> Bootstrapped/regtested on x86_64-linux and i686-linux, plus tested
> on self-tests with $COLUMNS down to 1, ok for trunk?
> 
> 2023-03-03  Jakub Jelinek  <jakub@redhat.com>
> 
>         PR testsuite/108973
>         * selftest-diagnostic.cc
>         (test_diagnostic_context::test_diagnostic_context): Ensure
>         caret_max_width isn't smaller than 80.
> 
> --- gcc/selftest-diagnostic.cc.jj       2023-01-02 09:32:31.991146491
> +0100
> +++ gcc/selftest-diagnostic.cc  2023-03-02 10:05:17.974321025 +0100
> @@ -41,6 +41,7 @@ test_diagnostic_context::test_diagnostic
>    show_column = true;
>    start_span = start_span_cb;
>    min_margin_width = 6;
> +  caret_max_width = MAX (caret_max_width, 80);
>  }

Thanks for working on this.

Patch is OK, but I wonder if it would even better to just hardcode
caret_max_width as 80 here, to better eliminate that influence from
from the environment in the unit tests?  I think all of the tests that
modify caret_max_width do so after the ctor has run.

Dave