Rollup merge of rust-lang#104895 - chenyukang:yukang/fix-104884-serde…

…, r=TaKO8Ki

Avoid Invalid code suggested when encountering unsatisfied trait bounds in derive macro code

Fixes rust-lang#104884

compiler/rustc_middle/src/ty/diagnostics.rs

@@ -355,6 +355,12 @@ pub fn suggest_constraining_type_params<'a>(
  ));
  }
 
+ // FIXME: remove the suggestions that are from derive, as the span is not correct
+ suggestions = suggestions
+ .into_iter()
+ .filter(|(span, _, _)| !span.in_derive_expansion())
+ .collect::<Vec<_>>();
+
  if suggestions.len() == 1 {
  let (span, suggestion, msg) = suggestions.pop().unwrap();
 

src/test/ui/proc-macro/auxiliary/issue-104884.rs

@@ -0,0 +1,23 @@
+// force-host
+// no-prefer-dynamic
+
+#![crate_type = "proc-macro"]
+
+extern crate proc_macro;
+
+use proc_macro::TokenStream;
+
+#[proc_macro_derive(AddImpl)]
+
+pub fn derive(input: TokenStream) -> TokenStream {
+ "use std::cmp::Ordering;
+
+ impl<T> Ord for PriorityQueue<T> {
+ fn cmp(&self, other: &Self) -> Ordering {
+ self.0.cmp(&self.height)
+ }
+ }
+ "
+ .parse()
+ .unwrap()
+}

src/test/ui/proc-macro/issue-104884-trait-impl-sugg-err.rs

@@ -0,0 +1,20 @@
+// aux-build:issue-104884.rs
+
+use std::collections::BinaryHeap;
+
+#[macro_use]
+extern crate issue_104884;
+
+#[derive(PartialEq, Eq, PartialOrd, Ord)]
+struct PriorityQueueEntry<T> {
+ value: T,
+}
+
+#[derive(PartialOrd, AddImpl)]
+//~^ ERROR can't compare `PriorityQueue<T>` with `PriorityQueue<T>`
+//~| ERROR the trait bound `PriorityQueue<T>: Eq` is not satisfied
+//~| ERROR can't compare `T` with `T`
+
+struct PriorityQueue<T>(BinaryHeap<PriorityQueueEntry<T>>);
+
+fn main() {}

src/test/ui/proc-macro/issue-104884-trait-impl-sugg-err.stderr

@@ -0,0 +1,48 @@
+error[E0277]: can't compare `PriorityQueue<T>` with `PriorityQueue<T>`
+ --> $DIR/issue-104884-trait-impl-sugg-err.rs:13:10
+ |
+LL | #[derive(PartialOrd, AddImpl)]
+ | ^^^^^^^^^^ no implementation for `PriorityQueue<T> == PriorityQueue<T>`
+ |
+ = help: the trait `PartialEq` is not implemented for `PriorityQueue<T>`
+note: required by a bound in `PartialOrd`
+ --> $SRC_DIR/core/src/cmp.rs:LL:COL
+ |
+LL | pub trait PartialOrd<Rhs: ?Sized = Self>: PartialEq<Rhs> {
+ | ^^^^^^^^^^^^^^ required by this bound in `PartialOrd`
+ = note: this error originates in the derive macro `PartialOrd` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0277]: the trait bound `PriorityQueue<T>: Eq` is not satisfied
+ --> $DIR/issue-104884-trait-impl-sugg-err.rs:13:22
+ |
+LL | #[derive(PartialOrd, AddImpl)]
+ | ^^^^^^^ the trait `Eq` is not implemented for `PriorityQueue<T>`
+ |
+note: required by a bound in `Ord`
+ --> $SRC_DIR/core/src/cmp.rs:LL:COL
+ |
+LL | pub trait Ord: Eq + PartialOrd<Self> {
+ | ^^ required by this bound in `Ord`
+ = note: this error originates in the derive macro `AddImpl` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0277]: can't compare `T` with `T`
+ --> $DIR/issue-104884-trait-impl-sugg-err.rs:13:22
+ |
+LL | #[derive(PartialOrd, AddImpl)]
+ | ^^^^^^^ no implementation for `T < T` and `T > T`
+ |
+note: required for `PriorityQueue<T>` to implement `PartialOrd`
+ --> $DIR/issue-104884-trait-impl-sugg-err.rs:13:10
+ |
+LL | #[derive(PartialOrd, AddImpl)]
+ | ^^^^^^^^^^
+note: required by a bound in `Ord`
+ --> $SRC_DIR/core/src/cmp.rs:LL:COL
+ |
+LL | pub trait Ord: Eq + PartialOrd<Self> {
+ | ^^^^^^^^^^^^^^^^ required by this bound in `Ord`
+ = note: this error originates in the derive macro `AddImpl` which comes from the expansion of the derive macro `PartialOrd` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: aborting due to 3 previous errors
+
+For more information about this error, try `rustc --explain E0277`.