Re: [PATCH] gdb/dwarf2: pass around DWARF expressions as gdb::array_view

[Simon Marchi <simon.marchi@polymtl.ca>]

On 2026-05-01 12:35, Tom Tromey wrote:
>>>>>> "Simon" == simon marchi <simon.marchi@polymtl.ca> writes:
> 
> Simon> This patch converts a bunch of functions to take or return DWARF
> Simon> expressions as `gdb::array_view<const gdb_byte>`, instead of raw pointer
> Simon> and size.  It doesn't do any non-trivial change to function
> Simon> implementations, but the idea is that we could change them (for example
> Simon> dwarf_expr_context::execute_stack_op) to operate on the array view
> Simon> directly, giving us bounds checking when building in debug mode.  But
> Simon> that is not as trivial.
> 
> I skimmed this and it seems fine to me.
> Approved-By: Tom Tromey <tom@tromey.com>

Thanks, pushed.

> Simon> This patch also doesn't change structure fields to array_views (for
> Simon> instance, dwarf2_loclist_baton), because that would make them
> Simon> non-trivially constructible, and we'd (technically) need to change how
> Simon> they are allocated.
> 
> I thought this sounded backward but I suppose it refers to the fact that
> these are stored in a union inside dwarf2_property_baton.
> 
> A fix for that might be to use a class hierarchy rather than a union.

Yes, I meant that we would start to have to call "new" on them.  They
are currently allocated with XOBNEW, which is disallows on
non-trivially-constructible types.  I guess that's what
allocate_on_obstack is for?  Anyway, I had to stop somewhere with this
patch otherwise the scope creeps too far.

Simon