Globally deduplicate matching fulfillment errors

Author: compiler-errors

compiler/rustc_typeck/src/check/fn_ctxt/checks.rs

@@ -15,7 +15,6 @@ use crate::check::{
 use crate::structured_errors::StructuredDiagnostic;
 
 use rustc_ast as ast;
-use rustc_data_structures::fx::FxHashSet;
 use rustc_errors::{pluralize, Applicability, Diagnostic, DiagnosticId, MultiSpan};
 use rustc_hir as hir;
 use rustc_hir::def::{CtorOf, DefKind, Res};
@@ -1618,12 +1617,6 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         &self,
         errors: &mut Vec<traits::FulfillmentError<'tcx>>,
     ) {
-        // Store a mapping from `(Span, Predicate) -> ObligationCause`, so that
-        // other errors that have the same span and predicate can also get fixed,
-        // even if their `ObligationCauseCode` isn't an `Expr*Obligation` kind.
-        // This is important since if we adjust one span but not the other, then
-        // we will have "duplicated" the error on the UI side.
-        let mut remap_cause = FxHashSet::default();
         let mut not_adjusted = vec![];
 
         for error in errors {
@@ -1634,6 +1627,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 // Store both the predicate and the predicate *without constness*
                 // since sometimes we instantiate and check both of these in a
                 // method call, for example.
+                let mut remap_cause = self.remap_fulfillment_cause.borrow_mut();
                 remap_cause.insert((
                     before_span,
                     error.obligation.predicate,
@@ -1652,9 +1646,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         }
 
         for error in not_adjusted {
-            for (span, predicate, cause) in &remap_cause {
+            for (span, predicate, cause) in &*self.remap_fulfillment_cause.borrow() {
                 if *predicate == error.obligation.predicate
-                    && span.contains(error.obligation.cause.span)
+                    && span.overlaps(error.obligation.cause.span)
                 {
                     error.obligation.cause = cause.clone();
                     continue;
@@ -1667,7 +1661,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         &self,
         error: &mut traits::FulfillmentError<'tcx>,
     ) -> bool {
-        let (traits::ExprItemObligation(def_id, hir_id, idx) | traits::ExprBindingObligation(def_id, _, hir_id, idx))
+        let (traits::ExprItemObligation(def_id, hir_id, idx)
+        | traits::ExprBindingObligation(def_id, _, hir_id, idx))
             = *error.obligation.cause.code().peel_derives() else { return false; };
         let hir = self.tcx.hir();
         let hir::Node::Expr(expr) = hir.get(hir_id) else { return false; };

compiler/rustc_typeck/src/check/fn_ctxt/mod.rs

@@ -4,6 +4,7 @@ mod checks;
 mod suggestions;
 
 pub use _impl::*;
+use rustc_data_structures::fx::FxHashSet;
 pub use suggestions::*;
 
 use crate::astconv::AstConv;
@@ -129,6 +130,14 @@ pub struct FnCtxt<'a, 'tcx> {
 
     /// True if the return type has an Opaque type
     pub(super) return_type_has_opaque: bool,
+
+    // Store a mapping from `(Span, Predicate) -> ObligationCause`, so that
+    // other errors that have the same span and predicate can also get fixed,
+    // even if their `ObligationCauseCode` isn't an `Expr{Item,Binding}Obligation`.
+    // This is important since if we adjust one span but not the other, then
+    // we will have "duplicated" the error on the UI side.
+    pub(super) remap_fulfillment_cause:
+        RefCell<FxHashSet<(Span, ty::Predicate<'tcx>, ObligationCause<'tcx>)>>,
 }
 
 impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
@@ -156,6 +165,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             inh,
             return_type_pre_known: true,
             return_type_has_opaque: false,
+            remap_fulfillment_cause: Default::default(),
         }
     }
 

src/test/ui/associated-types/associated-types-path-2.rs

@@ -29,14 +29,12 @@ pub fn f1_uint_uint() {
     f1(2u32, 4u32);
     //~^ ERROR `u32: Foo` is not satisfied
     //~| ERROR `u32: Foo` is not satisfied
-    //~| ERROR `u32: Foo` is not satisfied
 }
 
 pub fn f1_uint_int() {
     f1(2u32, 4i32);
     //~^ ERROR `u32: Foo` is not satisfied
     //~| ERROR `u32: Foo` is not satisfied
-    //~| ERROR `u32: Foo` is not satisfied
 }
 
 pub fn f2_int() {

src/test/ui/associated-types/associated-types-path-2.stderr

@@ -31,14 +31,6 @@ note: required by a bound in `f1`
 LL | pub fn f1<T: Foo>(a: T, x: T::A) {}
    |              ^^^ required by this bound in `f1`
 
-error[E0277]: the trait bound `u32: Foo` is not satisfied
-  --> $DIR/associated-types-path-2.rs:29:5
-   |
-LL |     f1(2u32, 4u32);
-   |     ^^^^^^^^^^^^^^ the trait `Foo` is not implemented for `u32`
-   |
-   = help: the trait `Foo` is implemented for `i32`
-
 error[E0277]: the trait bound `u32: Foo` is not satisfied
   --> $DIR/associated-types-path-2.rs:29:14
    |
@@ -48,7 +40,7 @@ LL |     f1(2u32, 4u32);
    = help: the trait `Foo` is implemented for `i32`
 
 error[E0277]: the trait bound `u32: Foo` is not satisfied
-  --> $DIR/associated-types-path-2.rs:36:8
+  --> $DIR/associated-types-path-2.rs:35:8
    |
 LL |     f1(2u32, 4i32);
    |     -- ^^^^ the trait `Foo` is not implemented for `u32`
@@ -63,23 +55,15 @@ LL | pub fn f1<T: Foo>(a: T, x: T::A) {}
    |              ^^^ required by this bound in `f1`
 
 error[E0277]: the trait bound `u32: Foo` is not satisfied
-  --> $DIR/associated-types-path-2.rs:36:5
-   |
-LL |     f1(2u32, 4i32);
-   |     ^^^^^^^^^^^^^^ the trait `Foo` is not implemented for `u32`
-   |
-   = help: the trait `Foo` is implemented for `i32`
-
-error[E0277]: the trait bound `u32: Foo` is not satisfied
-  --> $DIR/associated-types-path-2.rs:36:14
+  --> $DIR/associated-types-path-2.rs:35:14
    |
 LL |     f1(2u32, 4i32);
    |              ^^^^ the trait `Foo` is not implemented for `u32`
    |
    = help: the trait `Foo` is implemented for `i32`
 
 error[E0308]: mismatched types
-  --> $DIR/associated-types-path-2.rs:43:18
+  --> $DIR/associated-types-path-2.rs:41:18
    |
 LL |     let _: i32 = f2(2i32);
    |            ---   ^^^^^^^^ expected `i32`, found `u32`
@@ -91,7 +75,7 @@ help: you can convert a `u32` to an `i32` and panic if the converted value doesn
 LL |     let _: i32 = f2(2i32).try_into().unwrap();
    |                          ++++++++++++++++++++
 
-error: aborting due to 8 previous errors
+error: aborting due to 6 previous errors
 
 Some errors have detailed explanations: E0277, E0308.
 For more information about an error, try `rustc --explain E0277`.

src/test/ui/box/into-boxed-slice-fail.rs

@@ -6,9 +6,7 @@ fn main() {
     let boxed_slice = Box::new([1,2,3]) as Box<[u8]>;
     let _ = Box::into_boxed_slice(boxed_slice);
     //~^ ERROR the size for values of type `[u8]` cannot be known at compilation time
-    //~^^ ERROR the size for values of type `[u8]` cannot be known at compilation time
     let boxed_trait: Box<dyn Debug> = Box::new(5u8);
     let _ = Box::into_boxed_slice(boxed_trait);
     //~^ ERROR the size for values of type `dyn Debug` cannot be known at compilation time
-    //~^^ ERROR the size for values of type `dyn Debug` cannot be known at compilation time
 }

src/test/ui/box/into-boxed-slice-fail.stderr

@@ -13,17 +13,8 @@ note: required by a bound in `Box::<T, A>::into_boxed_slice`
 LL | impl<T, A: Allocator> Box<T, A> {
    |      ^ required by this bound in `Box::<T, A>::into_boxed_slice`
 
-error[E0277]: the size for values of type `[u8]` cannot be known at compilation time
-  --> $DIR/into-boxed-slice-fail.rs:7:13
-   |
-LL |     let _ = Box::into_boxed_slice(boxed_slice);
-   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
-   |
-   = help: the trait `Sized` is not implemented for `[u8]`
-   = note: slice and array elements must have `Sized` type
-
 error[E0277]: the size for values of type `dyn Debug` cannot be known at compilation time
-  --> $DIR/into-boxed-slice-fail.rs:11:35
+  --> $DIR/into-boxed-slice-fail.rs:10:35
    |
 LL |     let _ = Box::into_boxed_slice(boxed_trait);
    |             --------------------- ^^^^^^^^^^^ doesn't have a size known at compile-time
@@ -37,15 +28,6 @@ note: required by a bound in `Box::<T, A>::into_boxed_slice`
 LL | impl<T, A: Allocator> Box<T, A> {
    |      ^ required by this bound in `Box::<T, A>::into_boxed_slice`
 
-error[E0277]: the size for values of type `dyn Debug` cannot be known at compilation time
-  --> $DIR/into-boxed-slice-fail.rs:11:13
-   |
-LL |     let _ = Box::into_boxed_slice(boxed_trait);
-   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
-   |
-   = help: the trait `Sized` is not implemented for `dyn Debug`
-   = note: slice and array elements must have `Sized` type
-
-error: aborting due to 4 previous errors
+error: aborting due to 2 previous errors
 
 For more information about this error, try `rustc --explain E0277`.

src/test/ui/iterators/issue-28098.rs

@@ -1,15 +1,12 @@
 fn main() {
     let _ = Iterator::next(&mut ());
     //~^ ERROR `()` is not an iterator
-    //~| ERROR `()` is not an iterator
-    //~| ERROR `()` is not an iterator
 
     for _ in false {}
     //~^ ERROR `bool` is not an iterator
 
     let _ = Iterator::next(&mut ());
     //~^ ERROR `()` is not an iterator
-    //~| ERROR `()` is not an iterator
 
     other()
 }
@@ -19,12 +16,9 @@ pub fn other() {
 
     let _ = Iterator::next(&mut ());
     //~^ ERROR `()` is not an iterator
-    //~| ERROR `()` is not an iterator
-    //~| ERROR `()` is not an iterator
 
     let _ = Iterator::next(&mut ());
     //~^ ERROR `()` is not an iterator
-    //~| ERROR `()` is not an iterator
 
     for _ in false {}
     //~^ ERROR `bool` is not an iterator

src/test/ui/iterators/issue-28098.stderr

@@ -8,16 +8,8 @@ LL |     let _ = Iterator::next(&mut ());
    |
    = help: the trait `Iterator` is not implemented for `()`
 
-error[E0277]: `()` is not an iterator
-  --> $DIR/issue-28098.rs:2:13
-   |
-LL |     let _ = Iterator::next(&mut ());
-   |             ^^^^^^^^^^^^^^^^^^^^^^^ `()` is not an iterator
-   |
-   = help: the trait `Iterator` is not implemented for `()`
-
 error[E0277]: `bool` is not an iterator
-  --> $DIR/issue-28098.rs:7:14
+  --> $DIR/issue-28098.rs:5:14
    |
 LL |     for _ in false {}
    |              ^^^^^ `bool` is not an iterator
@@ -26,7 +18,7 @@ LL |     for _ in false {}
    = note: required for `bool` to implement `IntoIterator`
 
 error[E0277]: `()` is not an iterator
-  --> $DIR/issue-28098.rs:10:28
+  --> $DIR/issue-28098.rs:8:28
    |
 LL |     let _ = Iterator::next(&mut ());
    |             -------------- ^^^^^^^ `()` is not an iterator
@@ -36,23 +28,7 @@ LL |     let _ = Iterator::next(&mut ());
    = help: the trait `Iterator` is not implemented for `()`
 
 error[E0277]: `()` is not an iterator
-  --> $DIR/issue-28098.rs:10:13
-   |
-LL |     let _ = Iterator::next(&mut ());
-   |             ^^^^^^^^^^^^^^^^^^^^^^^ `()` is not an iterator
-   |
-   = help: the trait `Iterator` is not implemented for `()`
-
-error[E0277]: `()` is not an iterator
-  --> $DIR/issue-28098.rs:2:13
-   |
-LL |     let _ = Iterator::next(&mut ());
-   |             ^^^^^^^^^^^^^^ `()` is not an iterator
-   |
-   = help: the trait `Iterator` is not implemented for `()`
-
-error[E0277]: `()` is not an iterator
-  --> $DIR/issue-28098.rs:20:28
+  --> $DIR/issue-28098.rs:17:28
    |
 LL |     let _ = Iterator::next(&mut ());
    |             -------------- ^^^^^^^ `()` is not an iterator
@@ -62,15 +38,7 @@ LL |     let _ = Iterator::next(&mut ());
    = help: the trait `Iterator` is not implemented for `()`
 
 error[E0277]: `()` is not an iterator
-  --> $DIR/issue-28098.rs:20:13
-   |
-LL |     let _ = Iterator::next(&mut ());
-   |             ^^^^^^^^^^^^^^^^^^^^^^^ `()` is not an iterator
-   |
-   = help: the trait `Iterator` is not implemented for `()`
-
-error[E0277]: `()` is not an iterator
-  --> $DIR/issue-28098.rs:25:28
+  --> $DIR/issue-28098.rs:20:28
    |
 LL |     let _ = Iterator::next(&mut ());
    |             -------------- ^^^^^^^ `()` is not an iterator
@@ -79,31 +47,15 @@ LL |     let _ = Iterator::next(&mut ());
    |
    = help: the trait `Iterator` is not implemented for `()`
 
-error[E0277]: `()` is not an iterator
-  --> $DIR/issue-28098.rs:25:13
-   |
-LL |     let _ = Iterator::next(&mut ());
-   |             ^^^^^^^^^^^^^^^^^^^^^^^ `()` is not an iterator
-   |
-   = help: the trait `Iterator` is not implemented for `()`
-
 error[E0277]: `bool` is not an iterator
-  --> $DIR/issue-28098.rs:29:14
+  --> $DIR/issue-28098.rs:23:14
    |
 LL |     for _ in false {}
    |              ^^^^^ `bool` is not an iterator
    |
    = help: the trait `Iterator` is not implemented for `bool`
    = note: required for `bool` to implement `IntoIterator`
 
-error[E0277]: `()` is not an iterator
-  --> $DIR/issue-28098.rs:20:13
-   |
-LL |     let _ = Iterator::next(&mut ());
-   |             ^^^^^^^^^^^^^^ `()` is not an iterator
-   |
-   = help: the trait `Iterator` is not implemented for `()`
-
-error: aborting due to 12 previous errors
+error: aborting due to 6 previous errors
 
 For more information about this error, try `rustc --explain E0277`.

src/test/ui/on-unimplemented/multiple-impls.rs

@@ -32,14 +32,8 @@ impl Index<Bar<usize>> for [i32] {
 fn main() {
     Index::index(&[] as &[i32], 2u32);
     //~^ ERROR E0277
-    //~| ERROR E0277
-    //~| ERROR E0277
     Index::index(&[] as &[i32], Foo(2u32));
     //~^ ERROR E0277
-    //~| ERROR E0277
-    //~| ERROR E0277
     Index::index(&[] as &[i32], Bar(2u32));
     //~^ ERROR E0277
-    //~| ERROR E0277
-    //~| ERROR E0277
 }