Re: [PATCH v2 dwarves 1/5] dwarves: help dwarf loader spot functions with optimized-out parameters

[Arnaldo Carvalho de Melo <acme@kernel.org>]

Em Mon, Jan 30, 2023 at 09:25:17PM -0300, Arnaldo Carvalho de Melo escreveu:
> Em Mon, Jan 30, 2023 at 10:37:56PM +0000, Alan Maguire escreveu:
> > On 30/01/2023 20:23, Arnaldo Carvalho de Melo wrote:
> > > Em Mon, Jan 30, 2023 at 05:10:51PM -0300, Arnaldo Carvalho de Melo escreveu:
> > >> +++ b/dwarves.h
> > >> @@ -262,6 +262,7 @@ struct cu {
> > >>  	uint8_t		 has_addr_info:1;
> > >>  	uint8_t		 uses_global_strings:1;
> > >>  	uint8_t		 little_endian:1;
> > >> +	uint8_t		 nr_register_params;
> > >>  	uint16_t	 language;
> > >>  	unsigned long	 nr_inline_expansions;
> > >>  	size_t		 size_inline_expansions;
> > > 
>  
> > Thanks for this, never thought of cross-builds to be honest!
> 
> > Tested just now on x86_64 and aarch64 at my end, just ran
> > into one small thing on one system; turns out EM_RISCV isn't
> > defined if using a very old elf.h; below works around this
> > (dwarves otherwise builds fine on this system).
> 
> Ok, will add it and will test with containers for older distros too.

Its on the 'next' branch, so that it gets tested in the libbpf github
repo at:

https://github.com/libbpf/libbpf/actions/workflows/pahole.yml

It failed yesterday and today due to problems with the installation of
llvm, probably tomorrow it'll be back working as I saw some
notifications floating by.

I added the conditional EM_RISCV definition as well as removed the dup
iterator that Jiri noticed.

Thanks,

- Arnaldo
 
> > diff --git a/dwarf_loader.c b/dwarf_loader.c
> > index dba2d37..47a3bc2 100644
> > --- a/dwarf_loader.c
> > +++ b/dwarf_loader.c
> > @@ -992,6 +992,11 @@ static struct class_member *class_member__new(Dwarf_Die *die, struct cu *c
> >         return member;
> >  }
> >  
> > +/* for older elf.h */
> > +#ifndef EM_RISCV
> > +#define EM_RISCV       243
> > +#endif
> > +
> >  /* How many function parameters are passed via registers?  Used below in
> >   * determining if an argument has been optimized out or if it is simply
> >   * an argument > cu__nr_register_params().  Making cu__nr_register_params()
> 
> -- 
> 
> - Arnaldo

-- 

- Arnaldo