Re: Some libabigail RISC-V support issues

[Mark Wielaard <mark@klomp.org>]

Hi Dodji,

On Mon, Jan 08, 2024 at 04:13:39PM +0100, Dodji Seketeli wrote:
> Mark Wielaard <mark@klomp.org> a écrit:
> > [PATCH 1/2] Recognize EM_RISCV in e_machine_to_string
> >
> > Adds support for generating a human readable string for EM_RISCV.
> > It includes configure support in case the system elf.h doesn't
> > contain the macro. But that is just for really old systems, glibc
> > 2.24 added it.
> >
> > Note that elfutils libdw provides dwelf_elf_e_machine_string which
> > does a similar thing.
> 
> Oh, I see that elfutils has it since 0.177.  That's "new" :-).  We
> should then make libabigail's e_machine_to_string use
> dwelf_elf_e_machine_string and require using an elfutils version >= 0.177.  Now
> that elfutils supports pkg-config, it should be easy to require an
> elfutils version.  What do you think?

elfutils 0.177 was released in 2019 so should generally be availble.
It seems a good idea to use dwelf_elf_e_machine_string, but it
produces different descriptions. So it depends on if something depends
on it. If it is just a human readable description then I think the
strings from dwelf_elf_e_machine_string are nicer/more descriptive.

> > [PATCH 2/2] Fix ABG_ASSERT in build_ir_node_from_die for DW_TAG_member
> >
> > Fixes an assert that for some reason only shows up on riscv 
> > in runtesttypesstability against the DWARF for the test file:
> > test-types-stability/PR27165-libzmq.so.5.2.3
> >
> > The issue is that the DIE [2113c8] being checked is in a CU that is 
> > C++, but the dwarf reader current translation unit [b] is a GIMPLE 
> > (lto) one, marked as C99.
> 
> Oh, I see. Good catch.
> >
> > I think this is because that first compile unit contains a variable
> > DIE [35dcf] that has an abstract origin [21492f] with specification
> > [2113c8] and type [211bf6] in the later C++ CU.
> 
> Right.
> 
> > With this make check is all green on riscv.
> 
> Many thanks for this.
> 
> I am applying this patch first, then EM_RISCV one second.  That way, the
> build stays green from the first patch.

And it is green! \o/
https://builder.sourceware.org/buildbot/#/builders/libabigail-ubuntu-riscv

Cheers,

Mark