Auto merge of #127042 - GrigorenkoPV:derivative, r=compiler-errors

Switch from `derivative` to `derive-where`

This is a part of the effort to get rid of `syn 1.*` in compiler's dependencies: #109302

Derivative has not been maintained in nearly 3 years[^1]. It also depends on `syn 1.*`.

This PR replaces `derivative` with `derive-where`[^2], a not dead alternative, which uses `syn 2.*`.

A couple of `Debug` formats have changed around the skipped fields[^3], but I doubt this is an issue.

[^1]: https://github.com/mcarton/rust-derivative/issues/117
[^2]: https://lib.rs/crates/derive-where
[^3]: See the changes in `tests/ui`

2 files changed, 5 insertions, 10 deletions

diff --git a/compiler/rustc_middle/Cargo.toml b/compiler/rustc_middle/Cargo.toml
index 290ebde8712..69e3b703cce 100644
--- a/compiler/rustc_middle/Cargo.toml
+++ b/compiler/rustc_middle/Cargo.toml
@@ -6,7 +6,7 @@ edition = "2021"
 [dependencies]
 # tidy-alphabetical-start
 bitflags = "2.4.1"
-derivative = "2.2.0"
+derive-where = "1.2.7"
 either = "1.5.0"
 field-offset = "0.3.5"
 gsgdt = "0.1.2"
diff --git a/compiler/rustc_middle/src/mir/query.rs b/compiler/rustc_middle/src/mir/query.rs
index cd8e28522ec..acf4414c4d6 100644
--- a/compiler/rustc_middle/src/mir/query.rs
+++ b/compiler/rustc_middle/src/mir/query.rs
@@ -2,6 +2,7 @@
 
 use crate::mir;
 use crate::ty::{self, CoroutineArgsExt, OpaqueHiddenType, Ty, TyCtxt};
+use derive_where::derive_where;
 use rustc_data_structures::fx::FxIndexMap;
 use rustc_errors::ErrorGuaranteed;
 use rustc_hir::def_id::LocalDefId;
@@ -224,13 +225,7 @@ rustc_data_structures::static_assert_size!(ConstraintCategory<'_>, 16);
 /// See also `rustc_const_eval::borrow_check::constraints`.
 #[derive(Copy, Clone, Debug, Eq, PartialEq, Hash)]
 #[derive(TyEncodable, TyDecodable, HashStable, TypeVisitable, TypeFoldable)]
-#[derive(derivative::Derivative)]
-#[derivative(
-    PartialOrd,
-    Ord,
-    PartialOrd = "feature_allow_slow_enum",
-    Ord = "feature_allow_slow_enum"
-)]
+#[derive_where(PartialOrd, Ord)]
 pub enum ConstraintCategory<'tcx> {
     Return(ReturnConstraint),
     Yield,
@@ -240,7 +235,7 @@ pub enum ConstraintCategory<'tcx> {
     Cast {
         /// Whether this is an unsizing cast and if yes, this contains the target type.
         /// Region variables are erased to ReErased.
-        #[derivative(PartialOrd = "ignore", Ord = "ignore")]
+        #[derive_where(skip)]
         unsize_to: Option<Ty<'tcx>>,
     },
 
@@ -250,7 +245,7 @@ pub enum ConstraintCategory<'tcx> {
     ClosureBounds,
 
     /// Contains the function type if available.
-    CallArgument(#[derivative(PartialOrd = "ignore", Ord = "ignore")] Option<Ty<'tcx>>),
+    CallArgument(#[derive_where(skip)] Option<Ty<'tcx>>),
     CopyBound,
     SizedBound,
     Assignment,