Re: [PATCH 1/4] Calculate size and write correct DWARF5 header

[Jakub Jelinek <jakub@redhat.com>]

On Fri, Sep 25, 2020 at 06:35:43PM +0200, Mark Wielaard wrote:
> > > -      unsigned int headersz = cu->cu_kind == CU_TYPES ? 23 : 11;
> > > +      unsigned int headersz = (cu->cu_kind == CU_TYPES
> > > +			       ? 23 : (cu->cu_version >= 5 ? 12 : 11));
> > 
> > Is the DWARF 5 .debug_info types header also 23 bytes long?
> 
> DW_UT_type units are length (4) + version (2) + unit_type (1) +
> ptr_size (1) + abbrev_off (4) + signature (8) + type_off (4) = 28 bytes
> long. But we don't support those yet. When we do we need to distinguish
> between CU_TYPES_4 and CU_TYPES_5 because they can be both present.
> 
> For my first pass of adding DWARF5 support I was not planning on doing
> CU_TYPES_5 because as far as I know nothing produces it at the moment.
> But it shouldn't be too hard to add it at the same level that dwz
> supports CU_TYPES_4.
> 
> Is the patch (with the above fix) as attached for just compile and
> partial DWARF5 unit headers OK for now?

Ok, thanks.

> From c2cf77e0cdf05611bb0aa6ee6261acb13dff5634 Mon Sep 17 00:00:00 2001
> From: Mark Wielaard <mark@klomp.org>
> Date: Wed, 23 Sep 2020 01:48:39 +0200
> Subject: [PATCH] Calculate size and write correct DWARF5 compile and partial
>  unit headers.
> 
> 	* dwz.c (try_debug_info): Add header size check for cu_version 5.
> 	(read_debug_info): Likewise.
> 	(partition_dups_1): Add 1 to pu_size for cu_version 5.
> 	(create_import_tree): Include header_size, 13 or 14 depending on
> 	cu_version, in cost comparision.
> 	(compute_abbrevs): Adjust headersz depending on cu_version.
> 	(recompute_abbrevs): Likewise.
> 	(write_info): Write cu_version 5 unit type.

	Jakub