Re: [PATCH] [gdb/testsuite] Fix gdb.tui/wrap-line.exp

[Andrew Burgess via Gdb-patches <gdb-patches@sourceware.org>]

Tom de Vries via Gdb-patches <gdb-patches@sourceware.org> writes:

> PR testsuite/30458 reports the following FAIL:
> ...
> PASS: gdb.tui/wrap-line.exp: width-auto-detected: cli: wrap
> ^CQuit
> (gdb) WARNING: timeout in accept_gdb_output
> Screen Dump (size 50 columns x 24 rows, cursor at column 6, row 3):
>     0 Quit
>     1 (gdb) 7890123456789012345678901234567890123456789
>     2 W^CQuit
>     3 (gdb)
>   ...
> FAIL: gdb.tui/wrap-line.exp: width-auto-detected: cli: prompt after wrap
> ...
>
> The problem is that the regexp doesn't account for the ^C:
> ...
>     gdb_assert { [Term::wait_for "^WQuit"] } "prompt after wrap"
> ...
>
> Fix this by updating the regexp, and likewise in another place in the
> test-case where we use ^C.

Do we know why we sometimes manage to see '^C'?  I guess it's a timing
thing, but right now I'm at a loss for how we manage to see it.  It
appears that we print the wrapping line, that ends with 'W', and then
wait for this to be displayed.

At this point GDB should be in a stable state waiting in the
event-loop.

When we send \003 this should trigger an event, which should trigger
async_request_quit, which should result in the 'Quit' exception being
thrown, caught, and printed.

I think the '^C' must be getting printed from tui_redisplay_readline
maybe, but I can't see how that gets triggered with \003 in the input
buffer.

I only ask because if we understand why '^C' is sometimes printed then
we might be able to decide if this should always be printed, or never be
printed, and change GDB accordingly...

Thanks,
Andrew

>
> Tested on x86_64-linux.
>
> Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30458
> ---
>  gdb/testsuite/gdb.tui/wrap-line.exp | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/gdb/testsuite/gdb.tui/wrap-line.exp b/gdb/testsuite/gdb.tui/wrap-line.exp
> index 4587517504c..2bfe342e04d 100644
> --- a/gdb/testsuite/gdb.tui/wrap-line.exp
> +++ b/gdb/testsuite/gdb.tui/wrap-line.exp
> @@ -25,6 +25,8 @@ set cols 50
>  set lines 24
>  set dims [list $lines $cols]
>  
> +set re_control_c "(\\^C)?Quit"
> +
>  # Fill line, assuming we start after the gdb prompt.
>  proc fill_line { width } {
>      set res ""
> @@ -47,7 +49,7 @@ proc fill_line { width } {
>  proc test_wrap { wrap_width } {
>      # Generate a prompt and parse it.
>      send_gdb "\003"
> -    gdb_assert { [Term::wait_for "(^|$::gdb_prompt )Quit"] } "start line"
> +    gdb_assert { [Term::wait_for "(^|$::gdb_prompt )$::re_control_c"] } "start line"
>  
>      # Fill the line to just before wrapping.
>      set str [fill_line $wrap_width]
> @@ -64,7 +66,7 @@ proc test_wrap { wrap_width } {
>  
>      # Generate a prompt and parse it.
>      send_gdb "\003"
> -    gdb_assert { [Term::wait_for "^WQuit"] } "prompt after wrap"
> +    gdb_assert { [Term::wait_for "^W$::re_control_c"] } "prompt after wrap"
>  }
>  
>  # Test wrapping in both CLI and TUI.
>
> base-commit: 0cc8cc5e6f82b8d3d8e3803c6f7f5e63f0c866ad
> -- 
> 2.35.3