Change the default statusline format to print "no target" when lldb is
launched without a target. Currently, the statusline is empty, which
looks rather odd.
And use this functionality to replace the ASCII "|" with the same
full-geight line-drawing character used in diagnostics rendering on a
color terminal.
Fix a deadlock between the statusline mutex (in Debugger) and the output
file mutex (in LockedStreamFile). The deadlock occurs when the main
thread is calling the statusline callback while holding the output mutex
in Editline, while the default event thread is trying to update the
statusline.
Extend the uncritical section so we can redraw the statusline there.
The loop in Editline::GetCharacter should be unnecessary. It would only
loop if we had a successful read with length zero, which shouldn't be
possible or when we can't convert a partial UTF-8 character, in which
case we bail out.
rdar://149251156
When you run lldb without colors (`-X`), the status line looks weird
because it doesn't have a background. You end up with what appears to be
floating text at the bottom of your terminal.
This patch changes the statusline to use the reverse video effect, even
when colors are off. The effect doesn't introduce any new colors and
just inverts the foreground and background color.
I considered an alternative approach which changes the behavior of the
`-X` option, so that turning off colors doesn't prevent emitting
non-color related control characters such as bold, underline, and
reverse video. I decided to go with this more targeted fix as (1) nobody
is asking for this more general change and (2) it introduces significant
complexity to plumb this through using a setting and driver flag so that
it can be disabled when running the tests.
Fixes#134112.
Add a statusline to command-line LLDB to display information about the
current state of the debugger. The statusline is a dedicated area
displayed at the bottom of the screen. The information displayed is
configurable through a setting consisting of LLDB’s format strings.
Enablement
----------
The statusline is enabled by default, but can be disabled with the
following setting:
```
(lldb) settings set show-statusline false
```
Configuration
-------------
The statusline is configurable through the `statusline-format` setting.
The default configuration shows the target name, the current file, the
stop reason and any ongoing progress events.
```
(lldb) settings show statusline-format
statusline-format (format-string) = "${ansi.bg.blue}${ansi.fg.black}{${target.file.basename}}{ | ${line.file.basename}:${line.number}:${line.column}}{ | ${thread.stop-reason}}{ | {${progress.count} }${progress.message}}"
```
The statusline supersedes the current progress reporting implementation.
Consequently, the following settings no longer have any effect (but
continue to exist to not break anyone's `.lldbinit`):
```
show-progress -- Whether to show progress or not if the debugger's output is an interactive color-enabled terminal.
show-progress-ansi-prefix -- When displaying progress in a color-enabled terminal, use the ANSI terminal code specified in this format immediately before the progress message.
show-progress-ansi-suffix -- When displaying progress in a color-enabled terminal, use the ANSI terminal code specified in this format immediately after the progress message.
```
Format Strings
--------------
LLDB's format strings are documented in the LLDB documentation and on
the website: https://lldb.llvm.org/use/formatting.html#format-strings.
The current implementation is relatively limited but various
improvements have been discussed in the RFC.
One such improvement is being to display a string when a format string
is empty. Right now, when launching LLDB without a target, the
statusline will be empty, which is expected, but looks rather odd.
RFC
---
The full RFC can be found on Discourse:
https://discourse.llvm.org/t/rfc-lldb-statusline/83948
