Begin to abstract rustc_type_ir for rust-analyzer

Author: compiler-errors

Diff for: Cargo.lock

@@ -3967,11 +3967,22 @@ name = "rustc_index"
 version = "0.0.0"
 dependencies = [
  "arrayvec",
+ "rustc_index_macros",
  "rustc_macros",
  "rustc_serialize",
  "smallvec",
 ]
 
+[[package]]
+name = "rustc_index_macros"
+version = "0.0.0"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.29",
+ "synstructure 0.13.0",
+]
+
 [[package]]
 name = "rustc_infer"
 version = "0.0.0"

Diff for: compiler/rustc_index/Cargo.toml

@@ -8,9 +8,10 @@ edition = "2021"
 [dependencies]
 arrayvec = { version = "0.7", default-features = false }
 rustc_serialize = { path = "../rustc_serialize", optional = true }
+rustc_index_macros = { path = "../rustc_index_macros" }
 rustc_macros = { path = "../rustc_macros", optional = true }
 smallvec = "1.8.1"
 
 [features]
 default = ["nightly"]
-nightly = ["rustc_serialize", "rustc_macros"]
+nightly = ["rustc_serialize", "rustc_macros", "rustc_index_macros/nightly"]

Diff for: compiler/rustc_index/src/lib.rs

@@ -25,8 +25,7 @@ mod vec;
 
 pub use {idx::Idx, slice::IndexSlice, vec::IndexVec};
 
-#[cfg(feature = "rustc_macros")]
-pub use rustc_macros::newtype_index;
+pub use rustc_index_macros::newtype_index;
 
 /// Type size assertion. The first argument is a type and the second argument is its expected size.
 ///

Diff for: compiler/rustc_macros/src/lib.rs

@@ -17,7 +17,6 @@ use proc_macro::TokenStream;
 mod diagnostics;
 mod hash_stable;
 mod lift;
-mod newtype;
 mod query;
 mod serialize;
 mod symbols;
@@ -34,27 +33,6 @@ pub fn symbols(input: TokenStream) -> TokenStream {
     symbols::symbols(input.into()).into()
 }
 
-/// Creates a struct type `S` that can be used as an index with
-/// `IndexVec` and so on.
-///
-/// There are two ways of interacting with these indices:
-///
-/// - The `From` impls are the preferred way. So you can do
-///   `S::from(v)` with a `usize` or `u32`. And you can convert back
-///   to an integer with `u32::from(s)`.
-///
-/// - Alternatively, you can use the methods `S::new(v)` and `s.index()`
-///   to create/return a value.
-///
-/// Internally, the index uses a u32, so the index must not exceed
-/// `u32::MAX`. You can also customize things like the `Debug` impl,
-/// what traits are derived, and so forth via the macro.
-#[proc_macro]
-#[allow_internal_unstable(step_trait, rustc_attrs, trusted_step, spec_option_partial_eq)]
-pub fn newtype_index(input: TokenStream) -> TokenStream {
-    newtype::newtype(input)
-}
-
 decl_derive!([HashStable, attributes(stable_hasher)] => hash_stable::hash_stable_derive);
 decl_derive!(
     [HashStable_Generic, attributes(stable_hasher)] =>