Rollup merge of rust-lang#110504 - compiler-errors:tweak-borrow-sugg, r=cjgillot

Tweak borrow suggestion span

Avoids a `span_to_snippet` call when we don't need to surround the expression in parentheses. The fact that the suggestion was using the whole span of the expression rather than just appending a `&` was prevented me from using `// run-rustfix` in another PR (rust-lang#110432 (comment)).

Also some drive-by renames of functions that have been annoying me for a bit.

Author: Dylan-DPC

compiler/rustc_hir_typeck/src/demand.rs

@@ -275,13 +275,13 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         expected_ty_expr: Option<&'tcx hir::Expr<'tcx>>,
     ) -> bool {
         let expr = expr.peel_blocks();
-        if let Some((sp, msg, suggestion, applicability, verbose, annotation)) =
-            self.check_ref(expr, found, expected)
+        if let Some((suggestion, msg, applicability, verbose, annotation)) =
+            self.suggest_deref_or_ref(expr, found, expected)
         {
             if verbose {
-                err.span_suggestion_verbose(sp, msg, suggestion, applicability);
+                err.multipart_suggestion_verbose(msg, suggestion, applicability);
             } else {
-                err.span_suggestion(sp, msg, suggestion, applicability);
+                err.multipart_suggestion(msg, suggestion, applicability);
             }
             if annotation {
                 let suggest_annotation = match expr.peel_drop_temps().kind {
@@ -343,7 +343,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 err.span_label(sp, format!("{descr} `{name}` defined here"));
             }
             return true;
-        } else if self.check_for_cast(err, expr, found, expected, expected_ty_expr) {
+        } else if self.suggest_cast(err, expr, found, expected, expected_ty_expr) {
             return true;
         } else {
             let methods = self.get_conversion_methods(expr.span, expected, found, expr.hir_id);

compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs

@@ -1045,7 +1045,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             );
         }
 
-        self.check_for_inner_self(&mut err, source, rcvr_ty, item_name);
+        self.suggest_unwrapping_inner_self(&mut err, source, rcvr_ty, item_name);
 
         bound_spans.sort();
         bound_spans.dedup();
@@ -1132,7 +1132,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             }
         }
 
-        self.check_for_deref_method(&mut err, source, rcvr_ty, item_name, expected);
+        self.note_derefed_ty_has_method(&mut err, source, rcvr_ty, item_name, expected);
         return Some(err);
     }
 
@@ -1805,7 +1805,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         }
     }
 
-    fn check_for_inner_self(
+    fn suggest_unwrapping_inner_self(
         &self,
         err: &mut Diagnostic,
         source: SelfSource<'tcx>,
@@ -2175,7 +2175,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         }
     }
 
-    fn check_for_deref_method(
+    fn note_derefed_ty_has_method(
         &self,
         err: &mut Diagnostic,
         self_source: SelfSource<'tcx>,

compiler/rustc_hir_typeck/src/method/suggest.rs

@@ -16,7 +16,7 @@ LL | fn foo(a: &A, d: D, e: &E, g: G) {}
 help: consider borrowing here
    |
 LL |     foo(&&A, B, C, D, &E, F, G);
-   |                       ~~
+   |                       +
 help: remove the extra arguments
    |
 LL -     foo(&&A, B, C, D, E, F, G);

tests/ui/argument-suggestions/issue-97484.stderr

@@ -2,14 +2,16 @@ error[E0308]: mismatched types
   --> $DIR/issue-102206.rs:6:27
    |
 LL |     std::mem::size_of_val(foo());
-   |     --------------------- ^^^^^
-   |     |                     |
-   |     |                     expected `&_`, found future
-   |     |                     help: consider borrowing here: `&foo()`
+   |     --------------------- ^^^^^ expected `&_`, found future
+   |     |
    |     arguments to this function are incorrect
    |
 note: function defined here
   --> $SRC_DIR/core/src/mem/mod.rs:LL:COL
+help: consider borrowing here
+   |
+LL |     std::mem::size_of_val(&foo());
+   |                           +
 
 error: aborting due to previous error
 

tests/ui/async-await/issues/issue-102206.stderr

@@ -2,11 +2,14 @@ error[E0308]: mismatched types
   --> $DIR/coercion-slice.rs:4:21
    |
 LL |     let _: &[i32] = [0];
-   |            ------   ^^^
-   |            |        |
-   |            |        expected `&[i32]`, found `[{integer}; 1]`
-   |            |        help: consider borrowing here: `&[0]`
+   |            ------   ^^^ expected `&[i32]`, found `[{integer}; 1]`
+   |            |
    |            expected due to this
+   |
+help: consider borrowing here
+   |
+LL |     let _: &[i32] = &[0];
+   |                     +
 
 error: aborting due to previous error
 

tests/ui/coercion/coercion-slice.stderr

@@ -98,19 +98,23 @@ error[E0308]: mismatched types
   --> $DIR/deref-suggestion.rs:40:17
    |
 LL |     let s = S { u };
-   |                 ^
-   |                 |
-   |                 expected `&u32`, found integer
-   |                 help: consider borrowing here: `u: &u`
+   |                 ^ expected `&u32`, found integer
+   |
+help: consider borrowing here
+   |
+LL |     let s = S { u: &u };
+   |                 ++++
 
 error[E0308]: mismatched types
   --> $DIR/deref-suggestion.rs:42:20
    |
 LL |     let s = S { u: u };
-   |                    ^
-   |                    |
-   |                    expected `&u32`, found integer
-   |                    help: consider borrowing here: `&u`
+   |                    ^ expected `&u32`, found integer
+   |
+help: consider borrowing here
+   |
+LL |     let s = S { u: &u };
+   |                    +
 
 error[E0308]: mismatched types
   --> $DIR/deref-suggestion.rs:45:17

tests/ui/inference/deref-suggestion.stderr

@@ -2,10 +2,8 @@ error[E0308]: mismatched types
   --> $DIR/issue-11374.rs:26:15
    |
 LL |     c.read_to(v);
-   |       ------- ^
-   |       |       |
-   |       |       expected `&mut [u8]`, found `Vec<_>`
-   |       |       help: consider mutably borrowing here: `&mut v`
+   |       ------- ^ expected `&mut [u8]`, found `Vec<_>`
+   |       |
    |       arguments to this method are incorrect
    |
    = note: expected mutable reference `&mut [u8]`
@@ -15,6 +13,10 @@ note: method defined here
    |
 LL |     pub fn read_to(&mut self, vec: &mut [u8]) {
    |            ^^^^^^^            --------------
+help: consider mutably borrowing here
+   |
+LL |     c.read_to(&mut v);
+   |               ++++
 
 error: aborting due to previous error
 

tests/ui/issues/issue-11374.stderr

@@ -2,11 +2,14 @@ error[E0308]: mismatched types
   --> $DIR/issue-17033.rs:2:10
    |
 LL |     (*p)(())
-   |     ---- ^^
-   |     |    |
-   |     |    expected `&mut ()`, found `()`
-   |     |    help: consider mutably borrowing here: `&mut ()`
+   |     ---- ^^ expected `&mut ()`, found `()`
+   |     |
    |     arguments to this function are incorrect
+   |
+help: consider mutably borrowing here
+   |
+LL |     (*p)(&mut ())
+   |          ++++
 
 error: aborting due to previous error
 

tests/ui/issues/issue-17033.stderr

@@ -19,7 +19,7 @@ LL | fn print_x(_: &dyn Foo<Item=bool>, extra: &str) {
 help: consider borrowing here
    |
 LL |     print_x(&X);
-   |             ~~
+   |             +
 help: provide the argument
    |
 LL |     print_x(/* &dyn Foo<Item = bool> */, /* &str */);