Rollup merge of #93693 - rukai:91550, r=davidtwco

Suggest deriving required supertraits

closes https://github.com/rust-lang/rust/issues/91550

I chose to just hardcode handling for PartialOrd and PartialEq because that should be robust enough and I dont know how to go about doing it generically

r? rust-lang/diagnostics

compiler/rustc_typeck/src/check/method/suggest.rs

@@ -9,8 +9,10 @@ use rustc_hir::def_id::{DefId, LocalDefId};
 use rustc_hir::lang_items::LangItem;
 use rustc_hir::{ExprKind, Node, QPath};
 use rustc_infer::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind};
+use rustc_middle::traits::util::supertraits;
 use rustc_middle::ty::fast_reject::{simplify_type, SimplifyParams};
 use rustc_middle::ty::print::with_crate_prefix;
+use rustc_middle::ty::ToPolyTraitRef;
 use rustc_middle::ty::{self, DefIdTree, ToPredicate, Ty, TyCtxt, TypeFoldable};
 use rustc_span::lev_distance;
 use rustc_span::symbol::{kw, sym, Ident};
@@ -1196,9 +1198,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 Some(adt) if adt.did.is_local() => adt,
                 _ => continue,
             };
-            let can_derive = match self.tcx.get_diagnostic_name(trait_pred.def_id()) {
-                Some(sym::Default) => !adt.is_enum(),
-                Some(
+            if let Some(diagnostic_name) = self.tcx.get_diagnostic_name(trait_pred.def_id()) {
+                let can_derive = match diagnostic_name {
+                    sym::Default => !adt.is_enum(),
                     sym::Eq
                     | sym::PartialEq
                     | sym::Ord
@@ -1206,16 +1208,30 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     | sym::Clone
                     | sym::Copy
                     | sym::Hash
-                    | sym::Debug,
-                ) => true,
-                _ => false,
-            };
-            if can_derive {
-                derives.push((
-                    format!("{}", trait_pred.self_ty()),
-                    self.tcx.def_span(adt.did),
-                    format!("{}", trait_pred.trait_ref.print_only_trait_name()),
-                ));
+                    | sym::Debug => true,
+                    _ => false,
+                };
+                if can_derive {
+                    let self_name = trait_pred.self_ty().to_string();
+                    let self_span = self.tcx.def_span(adt.did);
+                    if let Some(poly_trait_ref) = pred.to_opt_poly_trait_pred() {
+                        for super_trait in supertraits(self.tcx, poly_trait_ref.to_poly_trait_ref())
+                        {
+                            if let Some(parent_diagnostic_name) =
+                                self.tcx.get_diagnostic_name(super_trait.def_id())
+                            {
+                                derives.push((
+                                    self_name.clone(),
+                                    self_span.clone(),
+                                    parent_diagnostic_name.to_string(),
+                                ));
+                            }
+                        }
+                    }
+                    derives.push((self_name, self_span, diagnostic_name.to_string()));
+                } else {
+                    traits.push(self.tcx.def_span(trait_pred.def_id()));
+                }
             } else {
                 traits.push(self.tcx.def_span(trait_pred.def_id()));
             }

src/test/ui/binop/issue-28837.stderr

@@ -272,9 +272,9 @@ note: an implementation of `PartialOrd<_>` might be missing for `A`
    |
 LL | struct A;
    | ^^^^^^^^^ must implement `PartialOrd<_>`
-help: consider annotating `A` with `#[derive(PartialOrd)]`
+help: consider annotating `A` with `#[derive(PartialEq, PartialOrd)]`
    |
-LL | #[derive(PartialOrd)]
+LL | #[derive(PartialEq, PartialOrd)]
    |
 
 error[E0369]: binary operation `<=` cannot be applied to type `A`
@@ -290,9 +290,9 @@ note: an implementation of `PartialOrd<_>` might be missing for `A`
    |
 LL | struct A;
    | ^^^^^^^^^ must implement `PartialOrd<_>`
-help: consider annotating `A` with `#[derive(PartialOrd)]`
+help: consider annotating `A` with `#[derive(PartialEq, PartialOrd)]`
    |
-LL | #[derive(PartialOrd)]
+LL | #[derive(PartialEq, PartialOrd)]
    |
 
 error[E0369]: binary operation `>` cannot be applied to type `A`
@@ -308,9 +308,9 @@ note: an implementation of `PartialOrd<_>` might be missing for `A`
    |
 LL | struct A;
    | ^^^^^^^^^ must implement `PartialOrd<_>`
-help: consider annotating `A` with `#[derive(PartialOrd)]`
+help: consider annotating `A` with `#[derive(PartialEq, PartialOrd)]`
    |
-LL | #[derive(PartialOrd)]
+LL | #[derive(PartialEq, PartialOrd)]
    |
 
 error[E0369]: binary operation `>=` cannot be applied to type `A`
@@ -326,9 +326,9 @@ note: an implementation of `PartialOrd<_>` might be missing for `A`
    |
 LL | struct A;
    | ^^^^^^^^^ must implement `PartialOrd<_>`
-help: consider annotating `A` with `#[derive(PartialOrd)]`
+help: consider annotating `A` with `#[derive(PartialEq, PartialOrd)]`
    |
-LL | #[derive(PartialOrd)]
+LL | #[derive(PartialEq, PartialOrd)]
    |
 
 error: aborting due to 15 previous errors

src/test/ui/derives/issue-91550.rs

@@ -0,0 +1,29 @@
+use std::collections::HashSet;
+
+/// natural case from the issue
+struct Value(u32);
+
+fn main() {
+    let hs = HashSet::<Value>::new();
+    hs.insert(Value(0)); //~ ERROR
+}
+
+/// synthetic cases
+pub struct NoDerives;
+
+struct Object<T>(T);
+impl<T: Eq> Object<T> {
+    fn use_eq(&self) {}
+}
+impl<T: Ord> Object<T> {
+    fn use_ord(&self) {}
+}
+impl<T: Ord + PartialOrd> Object<T> {
+    fn use_ord_and_partial_ord(&self) {}
+}
+
+fn function(foo: Object<NoDerives>) {
+    foo.use_eq(); //~ ERROR
+    foo.use_ord(); //~ ERROR
+    foo.use_ord_and_partial_ord(); //~ ERROR
+}

src/test/ui/derives/issue-91550.stderr

@@ -0,0 +1,84 @@
+error[E0599]: the method `insert` exists for struct `HashSet<Value>`, but its trait bounds were not satisfied
+  --> $DIR/issue-91550.rs:8:8
+   |
+LL | struct Value(u32);
+   | ------------------
+   | |
+   | doesn't satisfy `Value: Eq`
+   | doesn't satisfy `Value: Hash`
+...
+LL |     hs.insert(Value(0));
+   |        ^^^^^^ method cannot be called on `HashSet<Value>` due to unsatisfied trait bounds
+   |
+   = note: the following trait bounds were not satisfied:
+           `Value: Eq`
+           `Value: Hash`
+help: consider annotating `Value` with `#[derive(Eq, Hash, PartialEq)]`
+   |
+LL | #[derive(Eq, Hash, PartialEq)]
+   |
+
+error[E0599]: the method `use_eq` exists for struct `Object<NoDerives>`, but its trait bounds were not satisfied
+  --> $DIR/issue-91550.rs:26:9
+   |
+LL | pub struct NoDerives;
+   | --------------------- doesn't satisfy `NoDerives: Eq`
+LL | 
+LL | struct Object<T>(T);
+   | -------------------- method `use_eq` not found for this
+...
+LL |     foo.use_eq();
+   |         ^^^^^^ method cannot be called on `Object<NoDerives>` due to unsatisfied trait bounds
+   |
+   = note: the following trait bounds were not satisfied:
+           `NoDerives: Eq`
+help: consider annotating `NoDerives` with `#[derive(Eq, PartialEq)]`
+   |
+LL | #[derive(Eq, PartialEq)]
+   |
+
+error[E0599]: the method `use_ord` exists for struct `Object<NoDerives>`, but its trait bounds were not satisfied
+  --> $DIR/issue-91550.rs:27:9
+   |
+LL | pub struct NoDerives;
+   | --------------------- doesn't satisfy `NoDerives: Ord`
+LL | 
+LL | struct Object<T>(T);
+   | -------------------- method `use_ord` not found for this
+...
+LL |     foo.use_ord();
+   |         ^^^^^^^ method cannot be called on `Object<NoDerives>` due to unsatisfied trait bounds
+   |
+   = note: the following trait bounds were not satisfied:
+           `NoDerives: Ord`
+help: consider annotating `NoDerives` with `#[derive(Eq, Ord, PartialEq, PartialOrd)]`
+   |
+LL | #[derive(Eq, Ord, PartialEq, PartialOrd)]
+   |
+
+error[E0599]: the method `use_ord_and_partial_ord` exists for struct `Object<NoDerives>`, but its trait bounds were not satisfied
+  --> $DIR/issue-91550.rs:28:9
+   |
+LL | pub struct NoDerives;
+   | ---------------------
+   | |
+   | doesn't satisfy `NoDerives: Ord`
+   | doesn't satisfy `NoDerives: PartialOrd`
+LL | 
+LL | struct Object<T>(T);
+   | -------------------- method `use_ord_and_partial_ord` not found for this
+...
+LL |     foo.use_ord_and_partial_ord();
+   |         ^^^^^^^^^^^^^^^^^^^^^^^ method cannot be called on `Object<NoDerives>` due to unsatisfied trait bounds
+   |
+   = note: the following trait bounds were not satisfied:
+           `NoDerives: Ord`
+           `NoDerives: PartialOrd`
+help: consider annotating `NoDerives` with `#[derive(Eq, Ord, PartialEq, PartialOrd)]`
+   |
+LL | #[derive(Eq, Ord, PartialEq, PartialOrd)]
+   |
+
+error: aborting due to 4 previous errors
+
+For more information about this error, try `rustc --explain E0599`.

src/test/ui/union/union-derive-clone.mirunsafeck.stderr

@@ -16,9 +16,9 @@ LL |     let w = u.clone();
    = note: the following trait bounds were not satisfied:
            `CloneNoCopy: Copy`
            which is required by `U5<CloneNoCopy>: Clone`
-help: consider annotating `CloneNoCopy` with `#[derive(Copy)]`
+help: consider annotating `CloneNoCopy` with `#[derive(Clone, Copy)]`
    |
-LL | #[derive(Copy)]
+LL | #[derive(Clone, Copy)]
    |
 
 error[E0277]: the trait bound `U1: Copy` is not satisfied

src/test/ui/union/union-derive-clone.thirunsafeck.stderr

@@ -16,9 +16,9 @@ LL |     let w = u.clone();
    = note: the following trait bounds were not satisfied:
            `CloneNoCopy: Copy`
            which is required by `U5<CloneNoCopy>: Clone`
-help: consider annotating `CloneNoCopy` with `#[derive(Copy)]`
+help: consider annotating `CloneNoCopy` with `#[derive(Clone, Copy)]`
    |
-LL | #[derive(Copy)]
+LL | #[derive(Clone, Copy)]
    |
 
 error[E0277]: the trait bound `U1: Copy` is not satisfied