Re: Metadata style?

[Eli Zaretskii <eliz@gnu.org>]

> From: Tom Tromey <tromey@adacore.com>
> Cc: Tom Tromey <tromey@adacore.com>,  gdb-patches@sourceware.org
> Date: Thu, 07 Apr 2022 12:44:42 -0600
> 
> Eli> But there's no explanation in the manual what is the "metadata"
> Eli> object.  What is it, and how can I display it in GDB to see the style
> Eli> in action?
> 
> First, sorry about this, I completely slipped on writing documentation
> for this.
> 
> There's a test for this style:
> 
> 	gdb_test_no_output "set print repeat 3"
> 	gdb_test "print {0,0,0,0,0,0,0,0}" \
> 	    " = \\{0 [limited_style {<repeats.*8.*times>} metadata]\\}"
> 
> It's used in a number of places where gdb is attempting to display some
> kind of data from the inferior but instead prints some
> internally-generated text, e.g.:
> 
>   fprintf_styled (stream, metadata_style.style (), _("<unavailable>"));
> 
> I'm not completely sure of the best way to describe this.

Thanks.  How about the following addition to the manual?

--- gdb/doc/gdb.texinfo~0	2022-03-20 06:59:56.000000000 +0200
+++ gdb/doc/gdb.texinfo	2022-04-10 11:53:37.405750000 +0300
@@ -26283,6 +26283,16 @@
 the command @command{apropos -v REGEXP} uses the highlight style to
 mark the documentation parts matching @var{regexp}.
 
+@item metadata
+Control the styling of data annotations added by @value{GDBN} to data
+it displays.  By default, this style's intensity is dim.  Metadata
+annotations include the @samp{repeats @var{N} times} annotation for
+suppressed display of repeated array elements (@pxref{Print Strings}),
+@samp{<unavailable>} and @w{@samp{<error @var{descr}>}} annotations
+for errors and @samp{<optimized-out>} annotations for optimized-out
+values in displaying stack frame information in backtraces
+(@pxref{Backtrace}), etc.
+
 @item tui-border
 Control the styling of the TUI border.  Note that, unlike other
 styling options, only the color of the border can be controlled via