Re: [PATCH 0/2] Change Rust Binder crate name to rust_binder

[Alice Ryhl <aliceryhl@google.com>]

On Thu, Mar 05, 2026 at 12:34:16PM +0000, Gary Guo wrote:
> On Thu Mar 5, 2026 at 12:27 PM GMT, Alice Ryhl wrote:
> > On Thu, Mar 05, 2026 at 12:17:52PM +0000, Gary Guo wrote:
> >> On Thu Mar 5, 2026 at 10:49 AM GMT, Alice Ryhl wrote:
> >> > On Tue, Feb 24, 2026 at 03:17:16PM +0000, Alice Ryhl wrote:
> >> >> On Tue, Feb 24, 2026 at 02:24:59PM +0100, Miguel Ojeda wrote:
> >> >> > On Tue, Feb 24, 2026 at 10:38 AM Alice Ryhl <aliceryhl@google.com> wrote:
> >> >> > >
> >> >> > > Currently the crate name of the Rust Binder driver is rust_binder_main,
> >> >> > > but I'd like it to be called rust_binder instead. This affects e.g.
> >> >> > > symbol names in stack traces.
> >> >> > 
> >> >> > We discussed allowing to customize crate names years ago, at least for
> >> >> > dashes vs. underscores, for matching C names more closely and perhaps
> >> >> > other needs.
> >> >> > 
> >> >> > Back then, we decided to keep things simple to avoid confusion (i.e. a
> >> >> > single identifier used everywhere the same way is simpler, at least
> >> >> > for humans) and to avoid having to deal with those dual names
> >> >> > everywhere (e.g. adding workarounds for rust-analyzer here).
> >> >> > 
> >> >> > I talked with Alice about what she needed here -- could we rename that
> >> >> > source file to just something like `binder`? That would avoid the need
> >> >> > to have a custom name, so everything would still match (symbols,
> >> >> > source file, object file...), and it would give you even shorter
> >> >> > names.
> >> >> 
> >> >> Sure just renaming rust_binder_main.rs to binder.rs would work too.
> >> >
> >> > I realized that there's a much simpler way to allow crates to rename
> >> > themselves: do not pass the --crate-name argument at all.
> >> >
> >> > Because if you do not pass this argument, then rustc will use the
> >> > name of the .rs file as the crate name by default, *but* if the crate
> >> > contains #![crate_name = "..."], then that will be used instead.
> >> >
> >> > Do you still want to enforce that the crate name always matches the
> >> > file name? It seems unfortunate that it's currently impossible to create
> >> > a Rust module where the .ko file and crate name is the same, unless no
> >> > extra object files are linked into the module.
> >> 
> >> I think previously a fixed crate name is load-bearing because we need rustc to
> >> emit outputs to a fixed location.
> >> 
> >> This shouldn't be needed after commit 295d8398c67e ("kbuild: specify output
> >> names separately for each emission type from rustc"), so if nothing breaks with
> >> `--crate-name` removed, then I think it makes sense to drop it to allow custom
> >> rustflags to override them.
> >
> > Are you sure? I know this commit shows up in blame, but it just adds a
> > backslash to the --crate-name argument.
> >
> > I do not believe that omitting --crate-name changes anything in cases
> > where the crate name already matches the file name.
> 
> Before this change we rely on the crate name to match the file name, otherwise
> the .d file and .o file will be placed at wrong location and Kbuild cannot find
> the output files.
> 
> With this change we specify everything explicitly, so even if you pass
> `--crate-name=foo`, the object file is still `rust_binder.o` so the build can
> continue.
> 
> My point is that you *cannot* reasonably override crate names before this
> change.

Ok I understand now what you're getting at. That commit is required to
change the crate name (but it's not required to omit --crate-name
without changing what the crate name is).

Alice