From c5604cd0b58f1f2c527ae76dac75a94c7dd23824 Mon Sep 17 00:00:00 2001
From: Michael Goulet <michael@errs.io>
Date: Fri, 12 May 2023 20:34:51 +0000
Subject: [PATCH] Don't use can_eq in derive suggestion for missing method
---
.../rustc_hir_typeck/src/method/suggest.rs | 14 ---------
tests/ui/issues/issue-62375.stderr | 7 +++--
tests/ui/typeck/derive-sugg-arg-arity.rs | 8 +++++
tests/ui/typeck/derive-sugg-arg-arity.stderr | 31 +++++++++++++++++++
4 files changed, 44 insertions(+), 16 deletions(-)
create mode 100644 tests/ui/typeck/derive-sugg-arg-arity.rs
create mode 100644 tests/ui/typeck/derive-sugg-arg-arity.stderr
diff --git a/compiler/rustc_hir_typeck/src/method/suggest.rs b/compiler/rustc_hir_typeck/src/method/suggest.rs
index 486c217707e78..48ce2239ef3e4 100644
--- a/compiler/rustc_hir_typeck/src/method/suggest.rs
+++ b/compiler/rustc_hir_typeck/src/method/suggest.rs
@@ -2090,20 +2090,6 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
| sym::Hash
| sym::Debug => true,
_ => false,
- } && match trait_pred.trait_ref.substs.as_slice() {
- // Only suggest deriving if lhs == rhs...
- [lhs, rhs] => {
- if let Some(lhs) = lhs.as_type()
- && let Some(rhs) = rhs.as_type()
- {
- self.can_eq(self.param_env, lhs, rhs)
- } else {
- false
- }
- },
- // Unary ops can always be derived
- [_] => true,
- _ => false,
};
if can_derive {
let self_name = trait_pred.self_ty().to_string();
diff --git a/tests/ui/issues/issue-62375.stderr b/tests/ui/issues/issue-62375.stderr
index cd632e64fe5fc..f6d7968c0c405 100644
--- a/tests/ui/issues/issue-62375.stderr
+++ b/tests/ui/issues/issue-62375.stderr
@@ -11,8 +11,11 @@ note: an implementation of `PartialEq<fn(()) -> A {A::Value}>` might be missing
|
LL | enum A {
| ^^^^^^ must implement `PartialEq<fn(()) -> A {A::Value}>`
-note: the trait `PartialEq` must be implemented
- --> $SRC_DIR/core/src/cmp.rs:LL:COL
+help: consider annotating `A` with `#[derive(PartialEq)]`
+ |
+LL + #[derive(PartialEq)]
+LL | enum A {
+ |
help: use parentheses to construct this tuple variant
|
LL | a == A::Value(/* () */);
diff --git a/tests/ui/typeck/derive-sugg-arg-arity.rs b/tests/ui/typeck/derive-sugg-arg-arity.rs
new file mode 100644
index 0000000000000..094c93a8535d8
--- /dev/null
+++ b/tests/ui/typeck/derive-sugg-arg-arity.rs
@@ -0,0 +1,8 @@
+pub struct A;
+
+fn main() {
+ match () {
+ _ => match A::partial_cmp() {},
+ //~^ ERROR the function or associated item `partial_cmp` exists for struct `A`, but its trait bounds were not satisfied
+ }
+}
diff --git a/tests/ui/typeck/derive-sugg-arg-arity.stderr b/tests/ui/typeck/derive-sugg-arg-arity.stderr
new file mode 100644
index 0000000000000..5b4c481719830
--- /dev/null
+++ b/tests/ui/typeck/derive-sugg-arg-arity.stderr
@@ -0,0 +1,31 @@
+error[E0599]: the function or associated item `partial_cmp` exists for struct `A`, but its trait bounds were not satisfied
+ --> $DIR/derive-sugg-arg-arity.rs:5:23
+ |
+LL | pub struct A;
+ | ------------
+ | |
+ | function or associated item `partial_cmp` not found for this struct
+ | doesn't satisfy `A: Iterator`
+ | doesn't satisfy `A: PartialOrd<_>`
+...
+LL | _ => match A::partial_cmp() {},
+ | ^^^^^^^^^^^ function or associated item cannot be called on `A` due to unsatisfied trait bounds
+ |
+ = note: the following trait bounds were not satisfied:
+ `A: PartialOrd<_>`
+ which is required by `&A: PartialOrd<&_>`
+ `A: PartialOrd<_>`
+ which is required by `&mut A: PartialOrd<&mut _>`
+ `A: Iterator`
+ which is required by `&mut A: Iterator`
+note: the trait `Iterator` must be implemented
+ --> $SRC_DIR/core/src/iter/traits/iterator.rs:LL:COL
+help: consider annotating `A` with `#[derive(PartialEq, PartialOrd)]`
+ |
+LL + #[derive(PartialEq, PartialOrd)]
+LL | pub struct A;
+ |
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0599`.