rust: pin-init: add `syn` dependency and remove `proc-macro[2]` and `quote` workarounds

`syn` makes parsing Rust from proc-macros a lot simpler. `pin-init` has
not used `syn` up until now, because the we did not support it. That
changed in commit 54e3eae85562 ("Merge patch series "`syn` support""),
so we can finally utilize the added ergonomics of parsing proc-macro
input with `syn`.

Previously we only had the `proc-macro` library available, whereas the
user-space version also used `proc-macro2` and `quote`. Now both are
available, so remove the workarounds.

Due to these changes, clippy emits warnings about unnecessary
`.to_string()` as `proc-macro2` provides an additional `PartialEq` impl
on `Ident`, so the warnings are fixed.

[ Adjusted wording from upstream version and added build system changes
  for the kernel - Benno ]

Co-developed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Tamir Duberstein <tamird@gmail.com>
Tested-by: Andreas Hindborg <a.hindborg@kernel.org>
Signed-off-by: Benno Lossin <lossin@kernel.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/scripts/generate_rust_analyzer.py b/scripts/generate_rust_analyzer.py
index 147d0cc94068..d31d93888658 100755
--- a/scripts/generate_rust_analyzer.py
+++ b/scripts/generate_rust_analyzer.py
@@ -123,7 +123,7 @@ def generate_crates(srctree, objtree, sysroot_src, external_src, cfgs, core_edit
     append_crate(
         "pin_init_internal",
         srctree / "rust" / "pin-init" / "internal" / "src" / "lib.rs",
-        [],
+        ["std", "proc_macro", "proc_macro2", "quote", "syn"],
         cfg=["kernel"],
         is_proc_macro=True,
     )