Rollup merge of #120516 - Nadrieril:cleanup-impls, r=compiler-errors

pattern_analysis: cleanup manual impls

https://github.com/rust-lang/rust/pull/120420 introduced some unneeded manual impls. I remove them here.

r? ```@Nilstrieb```

compiler/rustc_pattern_analysis/src/constructor.rs

@@ -151,7 +151,6 @@
 use std::cmp::{self, max, min, Ordering};
 use std::fmt;
 use std::iter::once;
-use std::mem;
 
 use smallvec::SmallVec;
 
@@ -648,6 +647,7 @@ pub fn new() -> Self {
 /// `specialize_constructor` returns the list of fields corresponding to a pattern, given a
 /// constructor. `Constructor::apply` reconstructs the pattern from a pair of `Constructor` and
 /// `Fields`.
+#[derive(Debug)]
 pub enum Constructor<Cx: TypeCx> {
     /// Tuples and structs.
     Struct,
@@ -717,74 +717,6 @@ fn clone(&self) -> Self {
     }
 }
 
-impl<Cx: TypeCx> fmt::Debug for Constructor<Cx> {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match self {
-            Constructor::Struct => f.debug_tuple("Struct").finish(),
-            Constructor::Variant(idx) => f.debug_tuple("Variant").field(idx).finish(),
-            Constructor::Ref => f.debug_tuple("Ref").finish(),
-            Constructor::Slice(slice) => f.debug_tuple("Slice").field(slice).finish(),
-            Constructor::UnionField => f.debug_tuple("UnionField").finish(),
-            Constructor::Bool(b) => f.debug_tuple("Bool").field(b).finish(),
-            Constructor::IntRange(range) => f.debug_tuple("IntRange").field(range).finish(),
-            Constructor::F32Range(lo, hi, end) => {
-                f.debug_tuple("F32Range").field(lo).field(hi).field(end).finish()
-            }
-            Constructor::F64Range(lo, hi, end) => {
-                f.debug_tuple("F64Range").field(lo).field(hi).field(end).finish()
-            }
-            Constructor::Str(value) => f.debug_tuple("Str").field(value).finish(),
-            Constructor::Opaque(inner) => f.debug_tuple("Opaque").field(inner).finish(),
-            Constructor::Or => f.debug_tuple("Or").finish(),
-            Constructor::Wildcard => f.debug_tuple("Wildcard").finish(),
-            Constructor::NonExhaustive => f.debug_tuple("NonExhaustive").finish(),
-            Constructor::Hidden => f.debug_tuple("Hidden").finish(),
-            Constructor::Missing => f.debug_tuple("Missing").finish(),
-        }
-    }
-}
-
-impl<Cx: TypeCx> PartialEq for Constructor<Cx> {
-    fn eq(&self, other: &Self) -> bool {
-        (mem::discriminant(self) == mem::discriminant(other))
-            && match (self, other) {
-                (Constructor::Struct, Constructor::Struct) => true,
-                (Constructor::Variant(self_variant), Constructor::Variant(other_variant)) => {
-                    self_variant == other_variant
-                }
-                (Constructor::Ref, Constructor::Ref) => true,
-                (Constructor::Slice(self_slice), Constructor::Slice(other_slice)) => {
-                    self_slice == other_slice
-                }
-                (Constructor::UnionField, Constructor::UnionField) => true,
-                (Constructor::Bool(self_b), Constructor::Bool(other_b)) => self_b == other_b,
-                (Constructor::IntRange(self_range), Constructor::IntRange(other_range)) => {
-                    self_range == other_range
-                }
-                (
-                    Constructor::F32Range(self_lo, self_hi, self_end),
-                    Constructor::F32Range(other_lo, other_hi, other_end),
-                ) => self_lo == other_lo && self_hi == other_hi && self_end == other_end,
-                (
-                    Constructor::F64Range(self_lo, self_hi, self_end),
-                    Constructor::F64Range(other_lo, other_hi, other_end),
-                ) => self_lo == other_lo && self_hi == other_hi && self_end == other_end,
-                (Constructor::Str(self_value), Constructor::Str(other_value)) => {
-                    self_value == other_value
-                }
-                (Constructor::Opaque(self_inner), Constructor::Opaque(other_inner)) => {
-                    self_inner == other_inner
-                }
-                (Constructor::Or, Constructor::Or) => true,
-                (Constructor::Wildcard, Constructor::Wildcard) => true,
-                (Constructor::NonExhaustive, Constructor::NonExhaustive) => true,
-                (Constructor::Hidden, Constructor::Hidden) => true,
-                (Constructor::Missing, Constructor::Missing) => true,
-                _ => unreachable!(),
-            }
-    }
-}
-
 impl<Cx: TypeCx> Constructor<Cx> {
     pub(crate) fn is_non_exhaustive(&self) -> bool {
         matches!(self, NonExhaustive)

compiler/rustc_pattern_analysis/src/pat.rs

@@ -297,6 +297,7 @@ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
 
 /// Same idea as `DeconstructedPat`, except this is a fictitious pattern built up for diagnostics
 /// purposes. As such they don't use interning and can be cloned.
+#[derive(Debug)]
 pub struct WitnessPat<Cx: TypeCx> {
     ctor: Constructor<Cx>,
     pub(crate) fields: Vec<WitnessPat<Cx>>,
@@ -309,16 +310,6 @@ fn clone(&self) -> Self {
     }
 }
 
-impl<Cx: TypeCx> fmt::Debug for WitnessPat<Cx> {
-    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
-        fmt.debug_struct("WitnessPat")
-            .field("ctor", &self.ctor)
-            .field("fields", &self.fields)
-            .field("ty", &self.ty)
-            .finish()
-    }
-}
-
 impl<Cx: TypeCx> WitnessPat<Cx> {
     pub(crate) fn new(ctor: Constructor<Cx>, fields: Vec<Self>, ty: Cx::Ty) -> Self {
         Self { ctor, fields, ty }

compiler/rustc_pattern_analysis/src/usefulness.rs

@@ -1207,6 +1207,7 @@ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
 /// The final `Pair(Some(_), true)` is then the resulting witness.
 ///
 /// See the top of the file for more detailed explanations and examples.
+#[derive(Debug)]
 struct WitnessStack<Cx: TypeCx>(Vec<WitnessPat<Cx>>);
 
 impl<Cx: TypeCx> Clone for WitnessStack<Cx> {
@@ -1215,12 +1216,6 @@ fn clone(&self) -> Self {
     }
 }
 
-impl<Cx: TypeCx> fmt::Debug for WitnessStack<Cx> {
-    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
-        fmt.debug_tuple("WitnessStack").field(&self.0).finish()
-    }
-}
-
 impl<Cx: TypeCx> WitnessStack<Cx> {
     /// Asserts that the witness contains a single pattern, and returns it.
     fn single_pattern(self) -> WitnessPat<Cx> {
@@ -1265,6 +1260,7 @@ fn apply_constructor(&mut self, pcx: &PlaceCtxt<'_, Cx>, ctor: &Constructor<Cx>)
 ///
 /// Just as the `Matrix` starts with a single column, by the end of the algorithm, this has a single
 /// column, which contains the patterns that are missing for the match to be exhaustive.
+#[derive(Debug)]
 struct WitnessMatrix<Cx: TypeCx>(Vec<WitnessStack<Cx>>);
 
 impl<Cx: TypeCx> Clone for WitnessMatrix<Cx> {
@@ -1273,12 +1269,6 @@ fn clone(&self) -> Self {
     }
 }
 
-impl<Cx: TypeCx> fmt::Debug for WitnessMatrix<Cx> {
-    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
-        fmt.debug_tuple("WitnessMatrix").field(&self.0).finish()
-    }
-}
-
 impl<Cx: TypeCx> WitnessMatrix<Cx> {
     /// New matrix with no witnesses.
     fn empty() -> Self {