Fix; correct placement of type inference error for method calls

Jamesbarford · Jamesbarford · commit 5b99636a48d3 · 2025-10-06T11:42:43.000+01:00
diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs
@@ -2975,6 +2975,7 @@ impl<'a, 'b, 'tcx> ArgsCtxt<'a, 'b, 'tcx> {
                 IsSuggestion(true),
                 callee_ty.peel_refs(),
                 self.call_ctxt.callee_expr.unwrap().hir_id,
+                None,
                 TraitsInScope,
                 |mut ctxt| ctxt.probe_for_similar_candidate(),
             )
diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs
@@ -1794,6 +1794,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         self_ty,
                         expr.hir_id,
                         ProbeScope::TraitsInScope,
+                        Some(expr.span),
                     )
                 {
                     (pick.item, segment)
diff --git a/compiler/rustc_hir_typeck/src/method/mod.rs b/compiler/rustc_hir_typeck/src/method/mod.rs
@@ -104,6 +104,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             self_ty,
             call_expr_id,
             ProbeScope::TraitsInScope,
+            None,
         ) {
             Ok(pick) => {
                 pick.maybe_emit_unstable_name_collision_hint(
@@ -188,7 +189,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             ProbeScope::TraitsInScope
         };
 
-        let pick = self.lookup_probe(segment.ident, self_ty, call_expr, scope)?;
+        let pick = self.lookup_probe(segment.ident, self_ty, call_expr, self_expr, scope)?;
 
         self.lint_edition_dependent_dot_call(
             self_ty, segment, span, call_expr, self_expr, &pick, args,
@@ -215,6 +216,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     segment.ident,
                     trait_type,
                     call_expr,
+                    self_expr,
                     ProbeScope::TraitsInScope,
                 ) {
                     Ok(ref new_pick) if pick.differs_from(new_pick) => {
@@ -283,6 +285,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         method_name: Ident,
         self_ty: Ty<'tcx>,
         call_expr: &hir::Expr<'_>,
+        self_expr: &hir::Expr<'_>,
         scope: ProbeScope,
     ) -> probe::PickResult<'tcx> {
         let pick = self.probe_for_name(
@@ -293,7 +296,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             self_ty,
             call_expr.hir_id,
             scope,
+            Some(self_expr.span),
         )?;
+
         pick.maybe_emit_unstable_name_collision_hint(self.tcx, method_name.span, call_expr.hir_id);
         Ok(pick)
     }
@@ -314,6 +319,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             self_ty,
             call_expr.hir_id,
             scope,
+            None,
         )?;
         Ok(pick)
     }
@@ -533,6 +539,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             self_ty,
             expr_id,
             ProbeScope::TraitsInScope,
+            Some(self_ty_span),
         );
         let pick = match (pick, struct_variant) {
             // Fall back to a resolution that will produce an error later.
diff --git a/compiler/rustc_hir_typeck/src/method/probe.rs b/compiler/rustc_hir_typeck/src/method/probe.rs
@@ -296,6 +296,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 IsSuggestion(true),
                 self_ty,
                 scope_expr_id,
+                None,
                 ProbeScope::AllTraits,
                 |probe_cx| Ok(probe_cx.candidate_method_names(candidate_filter)),
             )
@@ -311,6 +312,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     IsSuggestion(true),
                     self_ty,
                     scope_expr_id,
+                    None,
                     ProbeScope::AllTraits,
                     |probe_cx| probe_cx.pick(),
                 )
@@ -330,6 +332,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         self_ty: Ty<'tcx>,
         scope_expr_id: HirId,
         scope: ProbeScope,
+        self_expr_span: Option<Span>,
     ) -> PickResult<'tcx> {
         self.probe_op(
             item_name.span,
@@ -339,6 +342,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             is_suggestion,
             self_ty,
             scope_expr_id,
+            self_expr_span,
             scope,
             |probe_cx| probe_cx.pick(),
         )
@@ -363,6 +367,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             is_suggestion,
             self_ty,
             scope_expr_id,
+            None,
             scope,
             |probe_cx| {
                 Ok(probe_cx
@@ -383,6 +388,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         is_suggestion: IsSuggestion,
         self_ty: Ty<'tcx>,
         scope_expr_id: HirId,
+        self_expr: Option<Span>,
         scope: ProbeScope,
         op: OP,
     ) -> Result<R, MethodError<'tcx>>
@@ -488,11 +494,10 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     ty::Infer(ty::TyVar(_)) => {
                         let raw_ptr_call = bad_ty.reached_raw_pointer
                             && !self.tcx.features().arbitrary_self_types();
-                        // FIXME: Ideally we'd use the span of the self-expr here,
-                        // not of the method path.
+
                         let mut err = self.err_ctxt().emit_inference_failure_err(
                             self.body_id,
-                            span,
+                            self_expr.unwrap_or(span),
                             ty.into(),
                             TypeAnnotationNeeded::E0282,
                             !raw_ptr_call,
diff --git a/compiler/rustc_hir_typeck/src/method/suggest.rs b/compiler/rustc_hir_typeck/src/method/suggest.rs
@@ -2114,6 +2114,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                             rcvr_ty,
                             expr_id,
                             ProbeScope::TraitsInScope,
+                            None,
                         )
                         .is_ok()
             })
@@ -3176,6 +3177,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 deref_ty,
                 ty.hir_id,
                 ProbeScope::TraitsInScope,
+                None,
             ) {
                 if deref_ty.is_suggestable(self.tcx, true)
                     // If this method receives `&self`, then the provided
diff --git a/tests/ui/autoref-autoderef/deref-ambiguity-becomes-nonambiguous.stderr b/tests/ui/autoref-autoderef/deref-ambiguity-becomes-nonambiguous.stderr
@@ -5,7 +5,7 @@ LL |     let var_fn = Value::wrap();
    |         ^^^^^^
 ...
 LL |     let _ = var_fn.clone();
-   |                    ----- type must be known at this point
+   |             ------ type must be known at this point
    |
 help: consider giving `var_fn` an explicit type, where the placeholders `_` are specified
    |
diff --git a/tests/ui/closures/deduce-signature/obligation-with-leaking-placeholders.next.stderr b/tests/ui/closures/deduce-signature/obligation-with-leaking-placeholders.next.stderr
@@ -5,7 +5,7 @@ LL |     needs_foo(|x| {
    |                ^
 ...
 LL |         x.to_string();
-   |           --------- type must be known at this point
+   |         - type must be known at this point
    |
 help: consider giving this closure parameter an explicit type
    |
diff --git a/tests/ui/impl-trait/hidden-type-is-opaque-2.default.stderr b/tests/ui/impl-trait/hidden-type-is-opaque-2.default.stderr
@@ -5,7 +5,7 @@ LL |     Thunk::new(|mut cont| {
    |                 ^^^^^^^^
 LL |
 LL |         cont.reify_as();
-   |              -------- type must be known at this point
+   |         ---- type must be known at this point
    |
 help: consider giving this closure parameter an explicit type
    |
@@ -19,7 +19,7 @@ LL |     Thunk::new(|mut cont| {
    |                 ^^^^^^^^
 LL |
 LL |         cont.reify_as();
-   |              -------- type must be known at this point
+   |         ---- type must be known at this point
    |
 help: consider giving this closure parameter an explicit type
    |
diff --git a/tests/ui/impl-trait/hidden-type-is-opaque-2.next.stderr b/tests/ui/impl-trait/hidden-type-is-opaque-2.next.stderr
@@ -5,7 +5,7 @@ LL |     Thunk::new(|mut cont| {
    |                 ^^^^^^^^
 LL |
 LL |         cont.reify_as();
-   |              -------- type must be known at this point
+   |         ---- type must be known at this point
    |
 help: consider giving this closure parameter an explicit type
    |
@@ -19,7 +19,7 @@ LL |     Thunk::new(|mut cont| {
    |                 ^^^^^^^^
 LL |
 LL |         cont.reify_as();
-   |              -------- type must be known at this point
+   |         ---- type must be known at this point
    |
 help: consider giving this closure parameter an explicit type
    |
diff --git a/tests/ui/inference/need_type_info/incompat-call-after-qualified-path-0.stderr b/tests/ui/inference/need_type_info/incompat-call-after-qualified-path-0.stderr
@@ -2,7 +2,7 @@ error[E0282]: type annotations needed
   --> $DIR/incompat-call-after-qualified-path-0.rs:21:6
    |
 LL |   f(|a, b| a.cmp(b));
-   |      ^       --- type must be known at this point
+   |      ^     - type must be known at this point
    |
 help: consider giving this closure parameter an explicit type
    |
diff --git a/tests/ui/inference/need_type_info/incompat-call-after-qualified-path-1.stderr b/tests/ui/inference/need_type_info/incompat-call-after-qualified-path-1.stderr
@@ -2,7 +2,7 @@ error[E0282]: type annotations needed
   --> $DIR/incompat-call-after-qualified-path-1.rs:25:6
    |
 LL |   f(|a, b| a.cmp(b));
-   |      ^       --- type must be known at this point
+   |      ^     - type must be known at this point
    |
 help: consider giving this closure parameter an explicit type
    |
diff --git a/tests/ui/issues/issue-20261.stderr b/tests/ui/issues/issue-20261.stderr
@@ -1,8 +1,8 @@
 error[E0282]: type annotations needed
-  --> $DIR/issue-20261.rs:4:11
+  --> $DIR/issue-20261.rs:4:9
    |
 LL |         i.clone();
-   |           ^^^^^ cannot infer type
+   |         ^ cannot infer type
 
 error: aborting due to 1 previous error
 
diff --git a/tests/ui/issues/issue-2151.stderr b/tests/ui/issues/issue-2151.stderr
@@ -4,7 +4,7 @@ error[E0282]: type annotations needed
 LL |     let x = panic!();
    |         ^
 LL |     x.clone();
-   |       ----- type must be known at this point
+   |     - type must be known at this point
    |
 help: consider giving `x` an explicit type
    |
diff --git a/tests/ui/lazy-type-alias-impl-trait/branches3.stderr b/tests/ui/lazy-type-alias-impl-trait/branches3.stderr
@@ -2,7 +2,7 @@ error[E0282]: type annotations needed
   --> $DIR/branches3.rs:9:10
    |
 LL |         |s| s.len()
-   |          ^    --- type must be known at this point
+   |          ^  - type must be known at this point
    |
 help: consider giving this closure parameter an explicit type
    |
@@ -13,7 +13,7 @@ error[E0282]: type annotations needed
   --> $DIR/branches3.rs:18:10
    |
 LL |         |s| s.len()
-   |          ^    --- type must be known at this point
+   |          ^  - type must be known at this point
    |
 help: consider giving this closure parameter an explicit type
    |
@@ -24,7 +24,7 @@ error[E0282]: type annotations needed
   --> $DIR/branches3.rs:26:10
    |
 LL |         |s| s.len()
-   |          ^    --- type must be known at this point
+   |          ^  - type must be known at this point
    |
 help: consider giving this closure parameter an explicit type
    |
@@ -35,7 +35,7 @@ error[E0282]: type annotations needed
   --> $DIR/branches3.rs:33:10
    |
 LL |         |s| s.len()
-   |          ^    --- type must be known at this point
+   |          ^  - type must be known at this point
    |
 help: consider giving this closure parameter an explicit type
    |
diff --git a/tests/ui/methods/call_method_unknown_pointee.stderr b/tests/ui/methods/call_method_unknown_pointee.stderr
@@ -1,11 +1,10 @@
 error[E0282]: type annotations needed
-  --> $DIR/call_method_unknown_pointee.rs:10:41
+  --> $DIR/call_method_unknown_pointee.rs:10:23
    |
 LL |         let _a: i32 = (ptr as *const _).read();
-   |                                         ^^^^
-   |                                         |
-   |                                         cannot infer type
-   |                                         cannot call a method on a raw pointer with an unknown pointee type
+   |                       ^^^^^^^^^^^^^^^^^ ---- cannot call a method on a raw pointer with an unknown pointee type
+   |                       |
+   |                       cannot infer type
 
 error[E0282]: type annotations needed for `*const _`
   --> $DIR/call_method_unknown_pointee.rs:12:13
@@ -22,13 +21,12 @@ LL |         let b: *const _ = ptr as *const _;
    |              ++++++++++
 
 error[E0282]: type annotations needed
-  --> $DIR/call_method_unknown_pointee.rs:21:39
+  --> $DIR/call_method_unknown_pointee.rs:21:23
    |
 LL |         let _a: i32 = (ptr as *mut _).read();
-   |                                       ^^^^
-   |                                       |
-   |                                       cannot infer type
-   |                                       cannot call a method on a raw pointer with an unknown pointee type
+   |                       ^^^^^^^^^^^^^^^ ---- cannot call a method on a raw pointer with an unknown pointee type
+   |                       |
+   |                       cannot infer type
 
 error[E0282]: type annotations needed for `*mut _`
   --> $DIR/call_method_unknown_pointee.rs:23:13
diff --git a/tests/ui/methods/call_method_unknown_referent.stderr b/tests/ui/methods/call_method_unknown_referent.stderr
@@ -1,14 +1,14 @@
 error[E0282]: type annotations needed
-  --> $DIR/call_method_unknown_referent.rs:20:31
+  --> $DIR/call_method_unknown_referent.rs:20:19
    |
 LL |     let _a: i32 = (ptr as &_).read();
-   |                               ^^^^ cannot infer type
+   |                   ^^^^^^^^^^^ cannot infer type
 
 error[E0282]: type annotations needed
-  --> $DIR/call_method_unknown_referent.rs:26:37
+  --> $DIR/call_method_unknown_referent.rs:26:14
    |
 LL |     let _b = (rc as std::rc::Rc<_>).read();
-   |                                     ^^^^ cannot infer type
+   |              ^^^^^^^^^^^^^^^^^^^^^^ cannot infer type
 
 error[E0599]: no method named `read` found for struct `SmartPtr<T>` in the current scope
   --> $DIR/call_method_unknown_referent.rs:46:35
diff --git a/tests/ui/proc-macro/quote/not-repeatable.stderr b/tests/ui/proc-macro/quote/not-repeatable.stderr
@@ -21,10 +21,10 @@ note: the traits `Iterator` and `ToTokens` must be implemented
   --> $SRC_DIR/core/src/iter/traits/iterator.rs:LL:COL
 
 error[E0282]: type annotations needed
-  --> $DIR/not-repeatable.rs:11:13
+  --> $DIR/not-repeatable.rs:11:25
    |
 LL |     let _ = quote! { $($ip)* };
-   |             ^^^^^^^^^^^^^^^^^^ cannot infer type
+   |                         ^^ cannot infer type
 
 error: aborting due to 2 previous errors
 
diff --git a/tests/ui/repeat-expr/copy-inference-side-effects-are-lazy.stderr b/tests/ui/repeat-expr/copy-inference-side-effects-are-lazy.stderr
@@ -5,7 +5,7 @@ LL |     let x = [Foo(PhantomData); 2];
    |         ^
 LL |
 LL |     extract(x).max(2);
-   |                --- type must be known at this point
+   |     ---------- type must be known at this point
    |
 help: consider giving `x` an explicit type, where the placeholders `_` are specified
    |
diff --git a/tests/ui/span/issue-42234-unknown-receiver-type.stderr b/tests/ui/span/issue-42234-unknown-receiver-type.stderr
@@ -4,7 +4,7 @@ error[E0282]: type annotations needed
 LL |     let x: Option<_> = None;
    |                        ^^^^ cannot infer type of the type parameter `T` declared on the enum `Option`
 LL |     x.unwrap().method_that_could_exist_on_some_type();
-   |                ------------------------------------ type must be known at this point
+   |     ---------- type must be known at this point
    |
 help: consider specifying the generic argument
    |
@@ -16,8 +16,6 @@ error[E0282]: type annotations needed
    |
 LL |         .sum::<_>()
    |          ^^^ cannot infer type of the type parameter `S` declared on the method `sum`
-LL |         .to_string()
-   |          --------- type must be known at this point
    |
 
 error: aborting due to 2 previous errors
diff --git a/tests/ui/type-alias-impl-trait/closures_in_branches.stderr b/tests/ui/type-alias-impl-trait/closures_in_branches.stderr
@@ -2,7 +2,7 @@ error[E0282]: type annotations needed
   --> $DIR/closures_in_branches.rs:8:10
    |
 LL |         |x| x.len()
-   |          ^    --- type must be known at this point
+   |          ^  - type must be known at this point
    |
 help: consider giving this closure parameter an explicit type
    |
@@ -13,7 +13,7 @@ error[E0282]: type annotations needed
   --> $DIR/closures_in_branches.rs:22:10
    |
 LL |         |x| x.len()
-   |          ^    --- type must be known at this point
+   |          ^  - type must be known at this point
    |
 help: consider giving this closure parameter an explicit type
    |
diff --git a/tests/ui/type-inference/regression-issue-81317.stderr b/tests/ui/type-inference/regression-issue-81317.stderr
diff --git a/tests/ui/typeck/issue-13853.stderr b/tests/ui/typeck/issue-13853.stderr

Original file line number	Diff line number	Diff line change
`@@ -2975,6 +2975,7 @@ impl<'a, 'b, 'tcx> ArgsCtxt<'a, 'b, 'tcx> {`
`2975`	`2975`	`IsSuggestion(true),`
`2976`	`2976`	`callee_ty.peel_refs(),`
`2977`	`2977`	`self.call_ctxt.callee_expr.unwrap().hir_id,`
	`2978`	`+ None,`
`2978`	`2979`	`TraitsInScope,`
`2979`	`2980`	`\|mut ctxt\| ctxt.probe_for_similar_candidate(),`
`2980`	`2981`	`)`
Original file line number	Diff line number	Diff line change
`@@ -1794,6 +1794,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {`
`1794`	`1794`	`self_ty,`
`1795`	`1795`	`expr.hir_id,`
`1796`	`1796`	`ProbeScope::TraitsInScope,`
	`1797`	`+ Some(expr.span),`
`1797`	`1798`	`)`
`1798`	`1799`	`{`
`1799`	`1800`	`(pick.item, segment)`
Original file line number	Diff line number	Diff line change
`@@ -5,7 +5,7 @@ LL \| let var_fn = Value::wrap();`
`5`	`5`	`\| ^^^^^^`
`6`	`6`	`...`
`7`	`7`	`LL \| let _ = var_fn.clone();`
`8`		`- \| ----- type must be known at this point`
	`8`	`+ \| ------ type must be known at this point`
`9`	`9`	`\|`
`10`	`10`	help: consider giving `var_fn` an explicit type, where the placeholders `_` are specified
`11`	`11`	`\|`
Original file line number	Diff line number	Diff line change
`@@ -5,7 +5,7 @@ LL \| needs_foo(\|x\| {`
`5`	`5`	`\| ^`
`6`	`6`	`...`
`7`	`7`	`LL \| x.to_string();`
`8`		`- \| --------- type must be known at this point`
	`8`	`+ \| - type must be known at this point`
`9`	`9`	`\|`
`10`	`10`	`help: consider giving this closure parameter an explicit type`
`11`	`11`	`\|`
Original file line number	Diff line number	Diff line change
`@@ -5,7 +5,7 @@ LL \| Thunk::new(\|mut cont\| {`
`5`	`5`	`\| ^^^^^^^^`
`6`	`6`	`LL \|`
`7`	`7`	`LL \| cont.reify_as();`
`8`		`- \| -------- type must be known at this point`
	`8`	`+ \| ---- type must be known at this point`
`9`	`9`	`\|`
`10`	`10`	`help: consider giving this closure parameter an explicit type`
`11`	`11`	`\|`
`@@ -19,7 +19,7 @@ LL \| Thunk::new(\|mut cont\| {`
`19`	`19`	`\| ^^^^^^^^`
`20`	`20`	`LL \|`
`21`	`21`	`LL \| cont.reify_as();`
`22`		`- \| -------- type must be known at this point`
	`22`	`+ \| ---- type must be known at this point`
`23`	`23`	`\|`
`24`	`24`	`help: consider giving this closure parameter an explicit type`
`25`	`25`	`\|`
Original file line number	Diff line number	Diff line change
`@@ -2,7 +2,7 @@ error[E0282]: type annotations needed`
`2`	`2`	`--> $DIR/incompat-call-after-qualified-path-0.rs:21:6`
`3`	`3`	`\|`
`4`	`4`	`LL \| f(\|a, b\| a.cmp(b));`
`5`		`- \| ^ --- type must be known at this point`
	`5`	`+ \| ^ - type must be known at this point`
`6`	`6`	`\|`
`7`	`7`	`help: consider giving this closure parameter an explicit type`
`8`	`8`	`\|`