Auto merge of rust-lang#117408 - compiler-errors:derive-eq, r=<try>

Use derivative for `PartialEq`/`Eq` in `rustc_type_ir`

r? `@ghost`

splitting this out for perf...

Author: bors

Cargo.lock

@@ -1011,6 +1011,17 @@ dependencies = [
  "syn 2.0.29",
 ]
 
+[[package]]
+name = "derivative"
+version = "2.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fcc3dd5e9e9c0b295d6e1e4d811fb6f157d5ffd784b8d202fc62eac8035a770b"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 1.0.109",
+]
+
 [[package]]
 name = "derive_builder"
 version = "0.12.0"
@@ -4668,6 +4679,7 @@ name = "rustc_type_ir"
 version = "0.0.0"
 dependencies = [
  "bitflags 1.3.2",
+ "derivative",
  "rustc_data_structures",
  "rustc_index",
  "rustc_macros",

compiler/rustc_type_ir/Cargo.toml

@@ -12,3 +12,4 @@ rustc_serialize = { path = "../rustc_serialize" }
 rustc_data_structures = { path = "../rustc_data_structures" }
 rustc_macros = { path = "../rustc_macros" }
 smallvec = { version = "1.8.1", features = ["union", "may_dangle"] }
+derivative = "2.2.0"

compiler/rustc_type_ir/src/canonical.rs

@@ -13,6 +13,8 @@ use crate::{HashStableContext, Interner, TyEncoder, UniverseIndex};
 /// A "canonicalized" type `V` is one where all free inference
 /// variables have been rewritten to "canonical vars". These are
 /// numbered starting from 0 in order of first appearance.
+#[derive(derivative::Derivative)]
+#[derivative(PartialEq(bound = "V: PartialEq"), Eq(bound = "V: Eq"))]
 pub struct Canonical<I: Interner, V> {
     pub value: V,
     pub max_universe: UniverseIndex,
@@ -78,16 +80,6 @@ where
     }
 }
 
-impl<I: Interner, V: Eq> Eq for Canonical<I, V> {}
-
-impl<I: Interner, V: PartialEq> PartialEq for Canonical<I, V> {
-    fn eq(&self, other: &Self) -> bool {
-        self.value == other.value
-            && self.max_universe == other.max_universe
-            && self.variables == other.variables
-    }
-}
-
 impl<I: Interner, V: fmt::Display> fmt::Display for Canonical<I, V> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         write!(

compiler/rustc_type_ir/src/const_kind.rs

@@ -13,7 +13,8 @@ use crate::{
 use self::ConstKind::*;
 
 /// Represents a constant in Rust.
-// #[derive(derive_more::From)]
+#[derive(derivative::Derivative)]
+#[derivative(PartialEq(bound = ""), Eq(bound = ""))]
 pub enum ConstKind<I: Interner> {
     /// A const generic parameter.
     Param(I::ParamConst),
@@ -193,24 +194,6 @@ impl<I: Interner> Ord for ConstKind<I> {
     }
 }
 
-impl<I: Interner> PartialEq for ConstKind<I> {
-    fn eq(&self, other: &Self) -> bool {
-        match (self, other) {
-            (Param(l0), Param(r0)) => l0 == r0,
-            (Infer(l0), Infer(r0)) => l0 == r0,
-            (Bound(l0, l1), Bound(r0, r1)) => l0 == r0 && l1 == r1,
-            (Placeholder(l0), Placeholder(r0)) => l0 == r0,
-            (Unevaluated(l0), Unevaluated(r0)) => l0 == r0,
-            (Value(l0), Value(r0)) => l0 == r0,
-            (Error(l0), Error(r0)) => l0 == r0,
-            (Expr(l0), Expr(r0)) => l0 == r0,
-            _ => false,
-        }
-    }
-}
-
-impl<I: Interner> Eq for ConstKind<I> {}
-
 impl<I: Interner> Clone for ConstKind<I> {
     fn clone(&self) -> Self {
         match self {

compiler/rustc_type_ir/src/predicate_kind.rs

@@ -12,6 +12,8 @@ use crate::{TyDecoder, TyEncoder};
 
 /// A clause is something that can appear in where bounds or be inferred
 /// by implied bounds.
+#[derive(derivative::Derivative)]
+#[derivative(PartialEq(bound = ""), Eq(bound = ""))]
 pub enum ClauseKind<I: Interner> {
     /// Corresponds to `where Foo: Bar<A, B, C>`. `Foo` here would be
     /// the `Self` type of the trait reference and `A`, `B`, and `C`
@@ -65,23 +67,6 @@ where
 {
 }
 
-impl<I: Interner> PartialEq for ClauseKind<I> {
-    fn eq(&self, other: &Self) -> bool {
-        match (self, other) {
-            (Self::Trait(l0), Self::Trait(r0)) => l0 == r0,
-            (Self::RegionOutlives(l0), Self::RegionOutlives(r0)) => l0 == r0,
-            (Self::TypeOutlives(l0), Self::TypeOutlives(r0)) => l0 == r0,
-            (Self::Projection(l0), Self::Projection(r0)) => l0 == r0,
-            (Self::ConstArgHasType(l0, l1), Self::ConstArgHasType(r0, r1)) => l0 == r0 && l1 == r1,
-            (Self::WellFormed(l0), Self::WellFormed(r0)) => l0 == r0,
-            (Self::ConstEvaluatable(l0), Self::ConstEvaluatable(r0)) => l0 == r0,
-            _ => false,
-        }
-    }
-}
-
-impl<I: Interner> Eq for ClauseKind<I> {}
-
 fn clause_kind_discriminant<I: Interner>(value: &ClauseKind<I>) -> usize {
     match value {
         ClauseKind::Trait(_) => 0,
@@ -249,6 +234,8 @@ where
     }
 }
 
+#[derive(derivative::Derivative)]
+#[derivative(PartialEq(bound = ""), Eq(bound = ""))]
 pub enum PredicateKind<I: Interner> {
     /// Prove a clause
     Clause(ClauseKind<I>),
@@ -324,27 +311,6 @@ impl<I: Interner> Clone for PredicateKind<I> {
     }
 }
 
-impl<I: Interner> PartialEq for PredicateKind<I> {
-    fn eq(&self, other: &Self) -> bool {
-        match (self, other) {
-            (Self::Clause(l0), Self::Clause(r0)) => l0 == r0,
-            (Self::ObjectSafe(l0), Self::ObjectSafe(r0)) => l0 == r0,
-            (Self::ClosureKind(l0, l1, l2), Self::ClosureKind(r0, r1, r2)) => {
-                l0 == r0 && l1 == r1 && l2 == r2
-            }
-            (Self::Subtype(l0), Self::Subtype(r0)) => l0 == r0,
-            (Self::Coerce(l0), Self::Coerce(r0)) => l0 == r0,
-            (Self::ConstEquate(l0, l1), Self::ConstEquate(r0, r1)) => l0 == r0 && l1 == r1,
-            (Self::AliasRelate(l0, l1, l2), Self::AliasRelate(r0, r1, r2)) => {
-                l0 == r0 && l1 == r1 && l2 == r2
-            }
-            _ => core::mem::discriminant(self) == core::mem::discriminant(other),
-        }
-    }
-}
-
-impl<I: Interner> Eq for PredicateKind<I> {}
-
 fn predicate_kind_discriminant<I: Interner>(value: &PredicateKind<I>) -> usize {
     match value {
         PredicateKind::Clause(_) => 0,

compiler/rustc_type_ir/src/region_kind.rs

@@ -118,6 +118,8 @@ use self::RegionKind::*;
 /// [1]: https://smallcultfollowing.com/babysteps/blog/2013/10/29/intermingled-parameter-lists/
 /// [2]: https://smallcultfollowing.com/babysteps/blog/2013/11/04/intermingled-parameter-lists/
 /// [rustc dev guide]: https://rustc-dev-guide.rust-lang.org/traits/hrtb.html
+#[derive(derivative::Derivative)]
+#[derivative(PartialEq(bound = ""), Eq(bound = ""))]
 pub enum RegionKind<I: Interner> {
     /// Region bound in a type or fn declaration which will be
     /// substituted 'early' -- that is, at the same time when type
@@ -194,34 +196,6 @@ impl<I: Interner> Clone for RegionKind<I> {
     }
 }
 
-// This is manually implemented because a derive would require `I: PartialEq`
-impl<I: Interner> PartialEq for RegionKind<I> {
-    #[inline]
-    fn eq(&self, other: &RegionKind<I>) -> bool {
-        regionkind_discriminant(self) == regionkind_discriminant(other)
-            && match (self, other) {
-                (ReEarlyBound(a_r), ReEarlyBound(b_r)) => a_r == b_r,
-                (ReLateBound(a_d, a_r), ReLateBound(b_d, b_r)) => a_d == b_d && a_r == b_r,
-                (ReFree(a_r), ReFree(b_r)) => a_r == b_r,
-                (ReStatic, ReStatic) => true,
-                (ReVar(a_r), ReVar(b_r)) => a_r == b_r,
-                (RePlaceholder(a_r), RePlaceholder(b_r)) => a_r == b_r,
-                (ReErased, ReErased) => true,
-                (ReError(_), ReError(_)) => true,
-                _ => {
-                    debug_assert!(
-                        false,
-                        "This branch must be unreachable, maybe the match is missing an arm? self = {self:?}, other = {other:?}"
-                    );
-                    true
-                }
-            }
-    }
-}
-
-// This is manually implemented because a derive would require `I: Eq`
-impl<I: Interner> Eq for RegionKind<I> {}
-
 // This is manually implemented because a derive would require `I: PartialOrd`
 impl<I: Interner> PartialOrd for RegionKind<I> {
     #[inline]

compiler/rustc_type_ir/src/ty_kind.rs

@@ -114,6 +114,8 @@ pub enum AliasKind {
 /// Types written by the user start out as `hir::TyKind` and get
 /// converted to this representation using `AstConv::ast_ty_to_ty`.
 #[rustc_diagnostic_item = "IrTyKind"]
+#[derive(derivative::Derivative)]
+#[derivative(PartialEq(bound = ""), Eq(bound = ""))]
 pub enum TyKind<I: Interner> {
     /// The primitive boolean type. Written as `bool`.
     Bool,
@@ -358,58 +360,6 @@ impl<I: Interner> Clone for TyKind<I> {
     }
 }
 
-// This is manually implemented because a derive would require `I: PartialEq`
-impl<I: Interner> PartialEq for TyKind<I> {
-    #[inline]
-    fn eq(&self, other: &TyKind<I>) -> bool {
-        // You might expect this `match` to be preceded with this:
-        //
-        //   tykind_discriminant(self) == tykind_discriminant(other) &&
-        //
-        // but the data patterns in practice are such that a comparison
-        // succeeds 99%+ of the time, and it's faster to omit it.
-        match (self, other) {
-            (Int(a_i), Int(b_i)) => a_i == b_i,
-            (Uint(a_u), Uint(b_u)) => a_u == b_u,
-            (Float(a_f), Float(b_f)) => a_f == b_f,
-            (Adt(a_d, a_s), Adt(b_d, b_s)) => a_d == b_d && a_s == b_s,
-            (Foreign(a_d), Foreign(b_d)) => a_d == b_d,
-            (Array(a_t, a_c), Array(b_t, b_c)) => a_t == b_t && a_c == b_c,
-            (Slice(a_t), Slice(b_t)) => a_t == b_t,
-            (RawPtr(a_t), RawPtr(b_t)) => a_t == b_t,
-            (Ref(a_r, a_t, a_m), Ref(b_r, b_t, b_m)) => a_r == b_r && a_t == b_t && a_m == b_m,
-            (FnDef(a_d, a_s), FnDef(b_d, b_s)) => a_d == b_d && a_s == b_s,
-            (FnPtr(a_s), FnPtr(b_s)) => a_s == b_s,
-            (Dynamic(a_p, a_r, a_repr), Dynamic(b_p, b_r, b_repr)) => {
-                a_p == b_p && a_r == b_r && a_repr == b_repr
-            }
-            (Closure(a_d, a_s), Closure(b_d, b_s)) => a_d == b_d && a_s == b_s,
-            (Coroutine(a_d, a_s, a_m), Coroutine(b_d, b_s, b_m)) => {
-                a_d == b_d && a_s == b_s && a_m == b_m
-            }
-            (CoroutineWitness(a_d, a_s), CoroutineWitness(b_d, b_s)) => a_d == b_d && a_s == b_s,
-            (Tuple(a_t), Tuple(b_t)) => a_t == b_t,
-            (Alias(a_i, a_p), Alias(b_i, b_p)) => a_i == b_i && a_p == b_p,
-            (Param(a_p), Param(b_p)) => a_p == b_p,
-            (Bound(a_d, a_b), Bound(b_d, b_b)) => a_d == b_d && a_b == b_b,
-            (Placeholder(a_p), Placeholder(b_p)) => a_p == b_p,
-            (Infer(a_t), Infer(b_t)) => a_t == b_t,
-            (Error(a_e), Error(b_e)) => a_e == b_e,
-            (Bool, Bool) | (Char, Char) | (Str, Str) | (Never, Never) => true,
-            _ => {
-                debug_assert!(
-                    tykind_discriminant(self) != tykind_discriminant(other),
-                    "This branch must be unreachable, maybe the match is missing an arm? self = self = {self:?}, other = {other:?}"
-                );
-                false
-            }
-        }
-    }
-}
-
-// This is manually implemented because a derive would require `I: Eq`
-impl<I: Interner> Eq for TyKind<I> {}
-
 // This is manually implemented because a derive would require `I: PartialOrd`
 impl<I: Interner> PartialOrd for TyKind<I> {
     #[inline]
@@ -614,6 +564,7 @@ impl<I: Interner> DebugWithInfcx<I> for TyKind<I> {
         }
     }
 }
+
 // This is manually implemented because a derive would require `I: Debug`
 impl<I: Interner> fmt::Debug for TyKind<I> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {

src/tools/tidy/src/deps.rs

@@ -142,6 +142,7 @@ const PERMITTED_RUSTC_DEPENDENCIES: &[&str] = &[
     "darling_core",
     "darling_macro",
     "datafrog",
+    "derivative",
     "derive_more",
     "derive_setters",
     "digest",