Re: [PATCH 3/4] print-symbol-loading.exp: Allow libc symbols to be already loaded

[Kevin Buettner <kevinb@redhat.com>]

On Fri, 11 Jun 2021 12:33:33 -0700
Kevin Buettner via Gdb-patches <gdb-patches@sourceware.org> wrote:

> On Fri, 11 Jun 2021 15:22:23 -0400
> Simon Marchi <simon.marchi@polymtl.ca> wrote:
>>		    }
> > > +        	    -re "^$cmd_regex\r\nSymbols already loaded for.*?\\/libc\\..*?\r\n$gdb_prompt $" {    
> > 
> > I'm just wondering about these regexps:
> > 
> >  - What does the sequence .*? mean in a regexp?
> >  - Doesn't having .* risk matching multiple lines, including some
> >    unexpected output that we wouldn't want to match?  Should we use the
> >    typical [^\r\n]* instead?  
> 
> The regexp ".*?" is the non-greedy variation of ".*".  I.e. whereas ".*"
> matches as much as possible, ".*?" will match as little as possible.
> Therefore, ".*?\r\n" will only match only as much as needed until
> the next \r is found; therefore it will not match multiple lines.

After some IRC discussion, we both agreed that it'd be safer to use
[^\r\n]* instead.  So that line left quoted above looks like this now:

		    -re "^$cmd_regex\r\nSymbols already loaded for\[^\r\n\]*\\/libc\\.\[^\r\n\]*\r\n$gdb_prompt $" {

Kevin