Re: [PATCH v3 dwarves 5/8] btf_encoder: Represent "."-suffixed functions (".isra.0") in BTF

[Jiri Olsa <olsajiri@gmail.com>]

On Wed, Feb 08, 2023 at 11:43:18AM -0300, Arnaldo Carvalho de Melo wrote:
> Em Wed, Feb 08, 2023 at 02:19:20PM +0100, Jiri Olsa escreveu:
> > On Tue, Feb 07, 2023 at 05:14:59PM +0000, Alan Maguire wrote:
> > 
> > SNIP
> > 
> > > +
> > >  /*
> > >   * This corresponds to the same macro defined in
> > >   * include/linux/kallsyms.h
> > > @@ -818,6 +901,11 @@ static int functions_cmp(const void *_a, const void *_b)
> > >  	const struct elf_function *a = _a;
> > >  	const struct elf_function *b = _b;
> > >  
> > > +	/* if search key allows prefix match, verify target has matching
> > > +	 * prefix len and prefix matches.
> > > +	 */
> > > +	if (a->prefixlen && a->prefixlen == b->prefixlen)
> > > +		return strncmp(a->name, b->name, b->prefixlen);
> > >  	return strcmp(a->name, b->name);
> > >  }
> > >  
> > > @@ -850,14 +938,22 @@ static int btf_encoder__collect_function(struct btf_encoder *encoder, GElf_Sym *
> > >  	}
> > >  
> > >  	encoder->functions.entries[encoder->functions.cnt].name = name;
> > > +	if (strchr(name, '.')) {
> > > +		const char *suffix = strchr(name, '.');
> > > +
> > > +		encoder->functions.suffix_cnt++;
> > > +		encoder->functions.entries[encoder->functions.cnt].prefixlen = suffix - name;
> > > +	}
> > >  	encoder->functions.entries[encoder->functions.cnt].generated = false;
> > > +	encoder->functions.entries[encoder->functions.cnt].function = NULL;
> > 
> > should we zero functions.state in here? next patch adds other stuff
> > like got_parameter_names and parameter_names in it, so looks like it
> > could actually matter
> 
> Probably, but that can come as a followup patch, right?

sure, if Alan is ok with that

jirka

> 
> I've applied the patches, combining the patches documenting the two new
> command line options with the patches where those options are
> introduced.
> 
> Testing everything now.
> 
> Thanks,
> 
> - Arnaldo
>  
> > jirka
> > 
> > >  	encoder->functions.cnt++;
> > >  	return 0;
> > >  }
> > >  
> > > -static struct elf_function *btf_encoder__find_function(const struct btf_encoder *encoder, const char *name)
> > > +static struct elf_function *btf_encoder__find_function(const struct btf_encoder *encoder,
> > > +						       const char *name, size_t prefixlen)
> > >  {
> > > -	struct elf_function key = { .name = name };
> > > +	struct elf_function key = { .name = name, .prefixlen = prefixlen };
> > >  
> > 
> > SNIP
> 
> -- 
> 
> - Arnaldo