Re: [PATCH 1/3] Remove 'read' call from dwz_file::read_string

[Simon Marchi <simark@simark.ca>]

On 2025-03-23 15:20, Tom Tromey wrote:
> dwz_file::read_string calls 'read' on the section, but this isn't
> needed as the sections have all been pre-read.

In the long term, to remove unnecessary 'read' calls in a safe way, I
was thinking of introducing some kind of 'dwarf2_read_section_info' type
that would be a thin wrapper around a `dwarf2_section_info`, but one
that you could only obtain by calling `dwarf2_section_info::read`.  That
would be a kind of "token" to make sure that the section is safe to read
from.  A bit like when a function accepts an std::lock_guard object, it
is guaranteed that the lock is taken.

> @@ -261,7 +263,7 @@ dwarf2_read_dwz_file (dwarf2_per_objfile *per_objfile)
>      error (_("could not find '.gnu_debugaltlink' file for %s"),
>  	   per_bfd->filename ());
>  
> -  auto result = std::make_unique<dwz_file> (std::move (dwz_bfd));
> +  dwz_file_up result (new dwz_file (std::move (dwz_bfd)));

Why this change?

Otherwise, LGTM.

Approved-By: Simon Marchi <simon.marchi@efficios.com>

Simon