[PATCH 09/14] libdw, libdwfl: Save original path of ELF file

[Omar Sandoval]

On Thu, Nov 02, 2023 at 06:04:27PM +0100, Mark Wielaard wrote:
> Hi Omar,
> 
> On Wed, 2023-09-27 at 11:20 -0700, Omar Sandoval wrote:
> > libdw and libdwfl currently save the path of the directory containing
> > the ELF file to use when searching for alt and dwo files.  To search for
> > dwp files, we need the file name too.  Add an elfpath field to Dwarf,
> > and set the debugdir field from it.  Also update libdwfl to set elfpath
> > and debugdir.
> 
> This looks good. We will need some locking around this code when we
> integrate the thread-safety work. But that should be pretty clear.
> 
> > 
> > Signed-off-by: Omar Sandoval <osandov@fb.com>
> > ---
> >  libdw/ChangeLog                | 11 ++++++++++-
> >  libdw/dwarf_begin_elf.c        | 34 ++++++++++++++++++++--------------
> >  libdw/dwarf_end.c              |  3 ++-
> >  libdw/libdwP.h                 | 12 ++++++++++--
> >  libdwfl/ChangeLog              |  9 +++++++++
> >  libdwfl/dwfl_module.c          |  2 +-
> >  libdwfl/dwfl_module_getdwarf.c | 11 +++++++----
> >  libdwfl/libdwflP.h             |  2 +-
> >  libdwfl/offline.c              |  4 ++--
> >  9 files changed, 62 insertions(+), 26 deletions(-)
> > 
> > diff --git a/libdw/ChangeLog b/libdw/ChangeLog
> > index 1d229094..f491587f 100644
> > --- a/libdw/ChangeLog
> > +++ b/libdw/ChangeLog
> > @@ -20,7 +20,7 @@
> >  	instead of dbg parameter, which is now unused.
> >  	* libdwP.h (Dwarf_Macro_Op_Table): Replace is_64bit with address_size
> >  	and offset_size.  Add dbg.
> > -	(Dwarf): Add cu_index and tu_index.
> > +	(Dwarf): Add cu_index and tu_index.  Add elfpath.
> >  	(Dwarf_CU): Add dwp_row.
> >  	(Dwarf_Package_Index): New type.
> >  	(DW_SECT_TYPES): New macro.
> > @@ -28,6 +28,9 @@
> >  	(dwarf_cu_dwp_section_info): New INTDECL.
> >  	Add IDX_debug_cu_index and IDX_debug_tu_index.  Add
> >  	DWARF_E_UNKNOWN_SECTION.
> > +	(__libdw_debugdir): Replace declaration with...
> > +	(__libdw_elfpath): New declaration.
> > +	(__libdw_set_debugdir): New declaration.
> >  	* dwarf_begin_elf.c (dwarf_scnnames): Add IDX_debug_cu_index and
> >  	IDX_debug_tu_index.
> >  	(scn_to_string_section_idx): Ditto.
> > @@ -35,8 +38,14 @@
> >  	.zdebug_cu_index, and .zdebug_tu_index.
> >  	(check_section): Change .dwo suffix matching to account for
> >  	.debug_cu_index and .debug_tu_index.
> > +	(__libdw_debugdir): Replace with..
> > +	(__libdw_elfpath): New function.
> > +	(__libdw_set_debugdir): New function.
> > +	(valid_p): Call __libdw_elfpath and __libdw_set_debugdir instead of
> > +	__libdw_debugdir.
> >  	* Makefile.am (libdw_a_SOURCES): Add dwarf_cu_dwp_section_info.c.
> >  	* dwarf_end.c (dwarf_end): Free dwarf->cu_index and dwarf->tu_index.
> > +	Free dwarf->elfpath.
> >  	* dwarf_error.c (errmsgs): Add DWARF_E_UNKNOWN_SECTION.
> >  	* libdw.h (dwarf_cu_dwp_section_info): New declaration.
> >  	* libdw.map (ELFUTILS_0.190): Add dwarf_cu_dwp_section_info.
> 
> I had to recreate the ChangeLog entry because we skipped your patch 08.
> In the future lets just move the ChangeLog Entry into the commit
> message (we just updated CONTRIBUTING to recommend this). That makes
> rebasing slightly

Thanks for updating that, that's so much easier to work with :)