Re: [patch][rfc] Allow GDB to search for the right libthread_db.so.1

[Eli Zaretskii <eliz at gnu dot org>]

> Date: Fri, 17 Apr 2009 12:13:08 -0700
> From: Paul Pluzhnikov <ppluzhnikov@google.com>
> Cc: Thiago Jung Bauermann <bauerman@br.ibm.com>,         gdb-patches ml <gdb-patches@sourceware.org>
> 
> Attached is a revised patch, with updated ChangeLog and documentation
> changes.

Thanks.  Please also add a new entry to NEWS, in the "New options"
section.  We have just decided to have all the new options mentioned
there.

> doc/ChangeLog
> 
> 2009-04-17  Paul Pluzhnikov  <ppluzhnikov@google.com>
> 
> 	* gdb.texinfo (Threads): Document libthread-db-search-path.

This part is approved, with a few comments:

> +@table @code
> +@kindex set libthread-db-search-path
> +@item set libthread-db-search-path @r{[}@var{path}@r{]}
> +If this variable is set, @var{path} is a colon-separated list of
> +directories @value{GDBN} will use to search for @code{libthread_db}.

I would add here some suitable @cindex entry, for those who don't know
or don't remember the name of the variable.  Something like

  @cindex search path for @code{libthread_db}

> +If you omit @var{path}, @samp{libthread-db-search-path} will be reset to
> +empty list.

"will be reset to an empty list", with the article.

> +inferior process.  @value{GDBN} first attempts to use
> +@code{libthread_db} located in the same directory, from which
                                                    ^
In English, there's no need for a comma here.  Actually, it would
sound a bit better if you remove the word "same" from this sentence.

> +If none of @code{libthread_db} libraries initialize successfully,
> +thread debugging will be disabled.

I think we should mention here that GDB displays a warning in this
case.

> +Setting @code{libthread-db-search-path} is currently implemented
> +only for @sc{gnu}/Linux targets.

In general, mentioning specific platforms in the manual is a
maintenance nightmare, because we must remember to make changes in the
manual to track the support of the feature on other platforms.  It is
much better to say that this feature is available "only on some
platforms."  That's assuming that on other platforms, using the
command will cause a suitable error message; does it?

Btw, what are the Linux-specific aspects that this feature depends on?
Why can't we implement it on Solaris as well?