tweak "make mut" spans (No. 3)

Ezrashaw · Ezrashaw · commit 9329bb57773e · 2023-04-20T19:04:01.000+12:00
diff --git a/compiler/rustc_borrowck/src/diagnostics/mutability_errors.rs b/compiler/rustc_borrowck/src/diagnostics/mutability_errors.rs
@@ -1263,6 +1263,10 @@ fn suggest_ampmut<'tcx>(
     {
         let span = span.with_lo(span.lo() + BytePos(ws_pos as u32)).shrink_to_lo();
         (true, span, " mut".to_owned())
+    } else if binding_exists {
+        // shrink the span to just after the `&` in `&variable`
+        let span = span.with_lo(span.lo() + BytePos(1)).shrink_to_lo();
+        (true, span, "mut ".to_owned())
     } else {
         let ty_mut = local_decl.ty.builtin_deref(true).unwrap();
         assert_eq!(ty_mut.mutbl, hir::Mutability::Not);
diff --git a/tests/ui/borrowck/borrowck-assign-to-andmut-in-aliasable-loc.stderr b/tests/ui/borrowck/borrowck-assign-to-andmut-in-aliasable-loc.stderr
@@ -6,8 +6,8 @@ LL |     *s.pointer += 1;
    |
 help: consider changing this to be a mutable reference
    |
-LL | fn a(s: &mut S<'_>) {
-   |         ~~~~~~~~~~
+LL | fn a(s: &mut S) {
+   |          +++
 
 error[E0594]: cannot assign to `*s.pointer`, which is behind a `&` reference
   --> $DIR/borrowck-assign-to-andmut-in-aliasable-loc.rs:17:5
@@ -17,8 +17,8 @@ LL |     *s.pointer += 1;
    |
 help: consider changing this to be a mutable reference
    |
-LL | fn c(s: &mut &mut S<'_>) {
-   |         ~~~~~~~~~~~~~~~
+LL | fn c(s: &mut  &mut S) {
+   |          +++
 
 error: aborting due to 2 previous errors
 
diff --git a/tests/ui/borrowck/borrowck-borrow-mut-base-ptr-in-aliasable-loc.stderr b/tests/ui/borrowck/borrowck-borrow-mut-base-ptr-in-aliasable-loc.stderr
@@ -27,8 +27,8 @@ LL |     let x:  &mut isize = &mut **t0;
    |
 help: consider changing this to be a mutable reference
    |
-LL | fn foo4(t0: &mut &mut isize) {
-   |             ~~~~~~~~~~~~~~~
+LL | fn foo4(t0: &mut  &mut isize) {
+   |              +++
 
 error: aborting due to 3 previous errors
 
diff --git a/tests/ui/borrowck/borrowck-reborrow-from-mut.stderr b/tests/ui/borrowck/borrowck-reborrow-from-mut.stderr
@@ -111,7 +111,7 @@ LL |     let _bar1 = &mut foo.bar1;
 help: consider changing this to be a mutable reference
    |
 LL | fn borrow_mut_from_imm(foo: &mut Foo) {
-   |                             ~~~~~~~~
+   |                              +++
 
 error: aborting due to 11 previous errors
 
diff --git a/tests/ui/borrowck/mutability-errors.stderr b/tests/ui/borrowck/mutability-errors.stderr
@@ -7,7 +7,7 @@ LL |     *x = (1,);
 help: consider changing this to be a mutable reference
    |
 LL | fn named_ref(x: &mut (i32,)) {
-   |                 ~~~~~~~~~~~
+   |                  +++
 
 error[E0594]: cannot assign to `x.0`, which is behind a `&` reference
   --> $DIR/mutability-errors.rs:10:5
@@ -18,7 +18,7 @@ LL |     x.0 = 1;
 help: consider changing this to be a mutable reference
    |
 LL | fn named_ref(x: &mut (i32,)) {
-   |                 ~~~~~~~~~~~
+   |                  +++
 
 error[E0596]: cannot borrow `*x` as mutable, as it is behind a `&` reference
   --> $DIR/mutability-errors.rs:11:5
@@ -29,7 +29,7 @@ LL |     &mut *x;
 help: consider changing this to be a mutable reference
    |
 LL | fn named_ref(x: &mut (i32,)) {
-   |                 ~~~~~~~~~~~
+   |                  +++
 
 error[E0596]: cannot borrow `x.0` as mutable, as it is behind a `&` reference
   --> $DIR/mutability-errors.rs:12:5
@@ -40,7 +40,7 @@ LL |     &mut x.0;
 help: consider changing this to be a mutable reference
    |
 LL | fn named_ref(x: &mut (i32,)) {
-   |                 ~~~~~~~~~~~
+   |                  +++
 
 error[E0594]: cannot assign to data in a `&` reference
   --> $DIR/mutability-errors.rs:16:5
@@ -74,8 +74,8 @@ LL |     *x = (1,);
    |
 help: consider changing this to be a mutable pointer
    |
-LL | unsafe fn named_ptr(x: *mut (i32,)) {
-   |                        ~~~~~~~~~~~
+LL | unsafe fn named_ptr(x: *mut const (i32,)) {
+   |                         +++
 
 error[E0594]: cannot assign to `x.0`, which is behind a `*const` pointer
   --> $DIR/mutability-errors.rs:24:5
@@ -85,8 +85,8 @@ LL |     (*x).0 = 1;
    |
 help: consider changing this to be a mutable pointer
    |
-LL | unsafe fn named_ptr(x: *mut (i32,)) {
-   |                        ~~~~~~~~~~~
+LL | unsafe fn named_ptr(x: *mut const (i32,)) {
+   |                         +++
 
 error[E0596]: cannot borrow `*x` as mutable, as it is behind a `*const` pointer
   --> $DIR/mutability-errors.rs:25:5
@@ -96,8 +96,8 @@ LL |     &mut *x;
    |
 help: consider changing this to be a mutable pointer
    |
-LL | unsafe fn named_ptr(x: *mut (i32,)) {
-   |                        ~~~~~~~~~~~
+LL | unsafe fn named_ptr(x: *mut const (i32,)) {
+   |                         +++
 
 error[E0596]: cannot borrow `x.0` as mutable, as it is behind a `*const` pointer
   --> $DIR/mutability-errors.rs:26:5
@@ -107,8 +107,8 @@ LL |     &mut (*x).0;
    |
 help: consider changing this to be a mutable pointer
    |
-LL | unsafe fn named_ptr(x: *mut (i32,)) {
-   |                        ~~~~~~~~~~~
+LL | unsafe fn named_ptr(x: *mut const (i32,)) {
+   |                         +++
 
 error[E0594]: cannot assign to data in a `*const` pointer
   --> $DIR/mutability-errors.rs:30:5
diff --git a/tests/ui/did_you_mean/issue-38147-4.stderr b/tests/ui/did_you_mean/issue-38147-4.stderr
@@ -6,8 +6,8 @@ LL |     f.s.push('x');
    |
 help: consider changing this to be a mutable reference
    |
-LL | fn f(x: usize, f: &mut Foo<'_>) {
-   |                   ~~~~~~~~~~~~
+LL | fn f(x: usize, f: &mut Foo) {
+   |                    +++
 
 error: aborting due to previous error
 
diff --git a/tests/ui/did_you_mean/issue-39544.stderr b/tests/ui/did_you_mean/issue-39544.stderr
@@ -40,7 +40,7 @@ LL |         let _ = &mut other.x;
 help: consider changing this to be a mutable reference
    |
 LL |     fn foo1(&self, other: &mut Z) {
-   |                           ~~~~~~
+   |                            +++
 
 error[E0596]: cannot borrow `self.x` as mutable, as it is behind a `&` reference
   --> $DIR/issue-39544.rs:25:17
@@ -62,7 +62,7 @@ LL |         let _ = &mut other.x;
 help: consider changing this to be a mutable reference
    |
 LL |     fn foo2<'a>(&'a self, other: &mut Z) {
-   |                                  ~~~~~~
+   |                                   +++
 
 error[E0596]: cannot borrow `self.x` as mutable, as it is behind a `&` reference
   --> $DIR/issue-39544.rs:30:17
@@ -84,7 +84,7 @@ LL |         let _ = &mut other.x;
 help: consider changing this to be a mutable reference
    |
 LL |     fn foo3<'a>(self: &'a Self, other: &mut Z) {
-   |                                        ~~~~~~
+   |                                         +++
 
 error[E0596]: cannot borrow `other.x` as mutable, as it is behind a `&` reference
   --> $DIR/issue-39544.rs:35:17
@@ -95,7 +95,7 @@ LL |         let _ = &mut other.x;
 help: consider changing this to be a mutable reference
    |
 LL |     fn foo4(other: &mut Z) {
-   |                    ~~~~~~
+   |                     +++
 
 error[E0596]: cannot borrow `z.x` as mutable, as `z` is not declared as mutable
   --> $DIR/issue-39544.rs:41:13
@@ -117,7 +117,7 @@ LL |     let _ = &mut w.x;
 help: consider changing this to be a mutable reference
    |
 LL | pub fn with_arg(z: Z, w: &mut Z) {
-   |                          ~~~~~~
+   |                           +++
 
 error[E0594]: cannot assign to `*x.0`, which is behind a `&` reference
   --> $DIR/issue-39544.rs:48:5
diff --git a/tests/ui/nll/issue-57989.stderr b/tests/ui/nll/issue-57989.stderr
@@ -7,7 +7,7 @@ LL |     *x = 0;
 help: consider changing this to be a mutable reference
    |
 LL | fn f(x: &mut i32) {
-   |         ~~~~~~~~
+   |          +++
 
 error[E0506]: cannot assign to `*x` because it is borrowed
   --> $DIR/issue-57989.rs:5:5
diff --git a/tests/ui/span/borrowck-borrow-overloaded-auto-deref-mut.stderr b/tests/ui/span/borrowck-borrow-overloaded-auto-deref-mut.stderr
@@ -18,7 +18,7 @@ LL |     &mut x.y
 help: consider changing this to be a mutable reference
    |
 LL | fn deref_extend_mut_field1(x: &mut Own<Point>) -> &mut isize {
-   |                               ~~~~~~~~~~~~~~~
+   |                                +++
 
 error[E0499]: cannot borrow `*x` as mutable more than once at a time
   --> $DIR/borrowck-borrow-overloaded-auto-deref-mut.rs:78:19
@@ -82,7 +82,7 @@ LL |     x.y_mut()
 help: consider changing this to be a mutable reference
    |
 LL | fn deref_extend_mut_method1(x: &mut Own<Point>) -> &mut isize {
-   |                                ~~~~~~~~~~~~~~~
+   |                                 +++
 
 error[E0596]: cannot borrow `x` as mutable, as it is not declared as mutable
   --> $DIR/borrowck-borrow-overloaded-auto-deref-mut.rs:129:6
diff --git a/tests/ui/span/borrowck-call-is-borrow-issue-12224.stderr b/tests/ui/span/borrowck-call-is-borrow-issue-12224.stderr
@@ -19,7 +19,7 @@ LL |     (*f)();
 help: consider changing this to be a mutable reference
    |
 LL | fn test2<F>(f: &mut F) where F: FnMut() {
-   |                ~~~~~~
+   |                 +++
 
 error[E0596]: cannot borrow `f.f` as mutable, as it is behind a `&` reference
   --> $DIR/borrowck-call-is-borrow-issue-12224.rs:34:5
@@ -29,8 +29,8 @@ LL |     f.f.call_mut(())
    |
 help: consider changing this to be a mutable reference
    |
-LL | fn test4(f: &mut Test<'_>) {
-   |             ~~~~~~~~~~~~~
+LL | fn test4(f: &mut Test) {
+   |              +++
 
 error[E0507]: cannot move out of `f`, a captured variable in an `FnMut` closure
   --> $DIR/borrowck-call-is-borrow-issue-12224.rs:57:13
diff --git a/tests/ui/span/borrowck-call-method-from-mut-aliasable.stderr b/tests/ui/span/borrowck-call-method-from-mut-aliasable.stderr
@@ -7,7 +7,7 @@ LL |     x.h();
 help: consider changing this to be a mutable reference
    |
 LL | fn b(x: &mut Foo) {
-   |         ~~~~~~~~
+   |          +++
 
 error: aborting due to previous error
 
diff --git a/tests/ui/span/borrowck-fn-in-const-b.stderr b/tests/ui/span/borrowck-fn-in-const-b.stderr
@@ -7,7 +7,7 @@ LL |         x.push(format!("this is broken"));
 help: consider changing this to be a mutable reference
    |
 LL |     fn broken(x: &mut Vec<String>) {
-   |                  ~~~~~~~~~~~~~~~~
+   |                   +++
 
 error: aborting due to previous error
 
diff --git a/tests/ui/span/borrowck-object-mutability.stderr b/tests/ui/span/borrowck-object-mutability.stderr
@@ -7,7 +7,7 @@ LL |     x.borrowed_mut();
 help: consider changing this to be a mutable reference
    |
 LL | fn borrowed_receiver(x: &mut dyn Foo) {
-   |                         ~~~~~~~~~~~~
+   |                          +++
 
 error[E0596]: cannot borrow `*x` as mutable, as `x` is not declared as mutable
   --> $DIR/borrowck-object-mutability.rs:18:5
diff --git a/tests/ui/span/mut-arg-hint.stderr b/tests/ui/span/mut-arg-hint.stderr
@@ -7,7 +7,7 @@ LL |         a.push_str("bar");
 help: consider changing this to be a mutable reference
    |
 LL |     fn foo(mut a: &mut String) {
-   |                   ~~~~~~~~~~~
+   |                    +++
 
 error[E0596]: cannot borrow `*a` as mutable, as it is behind a `&` reference
   --> $DIR/mut-arg-hint.rs:8:5
@@ -29,7 +29,7 @@ LL |         a.push_str("foo");
 help: consider changing this to be a mutable reference
    |
 LL |     pub fn foo(mut a: &mut String) {
-   |                       ~~~~~~~~~~~
+   |                        +++
 
 error: aborting due to 3 previous errors
 
diff --git a/tests/ui/suggestions/issue-68049-2.stderr b/tests/ui/suggestions/issue-68049-2.stderr
@@ -6,8 +6,8 @@ LL |       *input = self.0;
    |
 help: consider changing that to be a mutable reference
    |
-LL |   fn example(&self, input: &mut i32); // should suggest here
-   |                            ~~~~~~~~
+LL |   fn example(&self, input: mut ); // should suggest here
+   |                            ~~~
 
 error[E0594]: cannot assign to `self.0`, which is behind a `&` reference
   --> $DIR/issue-68049-2.rs:17:5

Original file line number	Diff line number	Diff line change
`@@ -6,8 +6,8 @@ LL \| *s.pointer += 1;`
`6`	`6`	`\|`
`7`	`7`	`help: consider changing this to be a mutable reference`
`8`	`8`	`\|`
`9`		`-LL \| fn a(s: &mut S<'_>) {`
`10`		`- \| ~~~~~~~~~~`
	`9`	`+LL \| fn a(s: &mut S) {`
	`10`	`+ \| +++`
`11`	`11`
`12`	`12`	error[E0594]: cannot assign to `*s.pointer`, which is behind a `&` reference
`13`	`13`	`--> $DIR/borrowck-assign-to-andmut-in-aliasable-loc.rs:17:5`
`@@ -17,8 +17,8 @@ LL \| *s.pointer += 1;`
`17`	`17`	`\|`
`18`	`18`	`help: consider changing this to be a mutable reference`
`19`	`19`	`\|`
`20`		`-LL \| fn c(s: &mut &mut S<'_>) {`
`21`		`- \| ~~~~~~~~~~~~~~~`
	`20`	`+LL \| fn c(s: &mut &mut S) {`
	`21`	`+ \| +++`
`22`	`22`
`23`	`23`	`error: aborting due to 2 previous errors`
`24`	`24`
Original file line number	Diff line number	Diff line change
`@@ -27,8 +27,8 @@ LL \| let x: &mut isize = &mut **t0;`
`27`	`27`	`\|`
`28`	`28`	`help: consider changing this to be a mutable reference`
`29`	`29`	`\|`
`30`		`-LL \| fn foo4(t0: &mut &mut isize) {`
`31`		`- \| ~~~~~~~~~~~~~~~`
	`30`	`+LL \| fn foo4(t0: &mut &mut isize) {`
	`31`	`+ \| +++`
`32`	`32`
`33`	`33`	`error: aborting due to 3 previous errors`
`34`	`34`
Original file line number	Diff line number	Diff line change
`@@ -111,7 +111,7 @@ LL \| let _bar1 = &mut foo.bar1;`
`111`	`111`	`help: consider changing this to be a mutable reference`
`112`	`112`	`\|`
`113`	`113`	`LL \| fn borrow_mut_from_imm(foo: &mut Foo) {`
`114`		`- \| ~~~~~~~~`
	`114`	`+ \| +++`
`115`	`115`
`116`	`116`	`error: aborting due to 11 previous errors`
`117`	`117`
Original file line number	Diff line number	Diff line change
`@@ -6,8 +6,8 @@ LL \| f.s.push('x');`
`6`	`6`	`\|`
`7`	`7`	`help: consider changing this to be a mutable reference`
`8`	`8`	`\|`
`9`		`-LL \| fn f(x: usize, f: &mut Foo<'_>) {`
`10`		`- \| ~~~~~~~~~~~~`
	`9`	`+LL \| fn f(x: usize, f: &mut Foo) {`
	`10`	`+ \| +++`
`11`	`11`
`12`	`12`	`error: aborting due to previous error`
`13`	`13`
Original file line number	Diff line number	Diff line change
`@@ -7,7 +7,7 @@ LL \| *x = 0;`
`7`	`7`	`help: consider changing this to be a mutable reference`
`8`	`8`	`\|`
`9`	`9`	`LL \| fn f(x: &mut i32) {`
`10`		`- \| ~~~~~~~~`
	`10`	`+ \| +++`
`11`	`11`
`12`	`12`	error[E0506]: cannot assign to `*x` because it is borrowed
`13`	`13`	`--> $DIR/issue-57989.rs:5:5`
Original file line number	Diff line number	Diff line change
`@@ -19,7 +19,7 @@ LL \| (*f)();`
`19`	`19`	`help: consider changing this to be a mutable reference`
`20`	`20`	`\|`
`21`	`21`	`LL \| fn test2<F>(f: &mut F) where F: FnMut() {`
`22`		`- \| ~~~~~~`
	`22`	`+ \| +++`
`23`	`23`
`24`	`24`	error[E0596]: cannot borrow `f.f` as mutable, as it is behind a `&` reference
`25`	`25`	`--> $DIR/borrowck-call-is-borrow-issue-12224.rs:34:5`
`@@ -29,8 +29,8 @@ LL \| f.f.call_mut(())`
`29`	`29`	`\|`
`30`	`30`	`help: consider changing this to be a mutable reference`
`31`	`31`	`\|`
`32`		`-LL \| fn test4(f: &mut Test<'_>) {`
`33`		`- \| ~~~~~~~~~~~~~`
	`32`	`+LL \| fn test4(f: &mut Test) {`
	`33`	`+ \| +++`
`34`	`34`
`35`	`35`	error[E0507]: cannot move out of `f`, a captured variable in an `FnMut` closure
`36`	`36`	`--> $DIR/borrowck-call-is-borrow-issue-12224.rs:57:13`
Original file line number	Diff line number	Diff line change
`@@ -7,7 +7,7 @@ LL \| x.h();`
`7`	`7`	`help: consider changing this to be a mutable reference`
`8`	`8`	`\|`
`9`	`9`	`LL \| fn b(x: &mut Foo) {`
`10`		`- \| ~~~~~~~~`
	`10`	`+ \| +++`
`11`	`11`
`12`	`12`	`error: aborting due to previous error`
`13`	`13`
Original file line number	Diff line number	Diff line change
`@@ -7,7 +7,7 @@ LL \| x.push(format!("this is broken"));`
`7`	`7`	`help: consider changing this to be a mutable reference`
`8`	`8`	`\|`
`9`	`9`	`LL \| fn broken(x: &mut Vec<String>) {`
`10`		`- \| ~~~~~~~~~~~~~~~~`
	`10`	`+ \| +++`
`11`	`11`
`12`	`12`	`error: aborting due to previous error`
`13`	`13`
Original file line number	Diff line number	Diff line change
`@@ -7,7 +7,7 @@ LL \| x.borrowed_mut();`
`7`	`7`	`help: consider changing this to be a mutable reference`
`8`	`8`	`\|`
`9`	`9`	`LL \| fn borrowed_receiver(x: &mut dyn Foo) {`
`10`		`- \| ~~~~~~~~~~~~`
	`10`	`+ \| +++`
`11`	`11`
`12`	`12`	error[E0596]: cannot borrow `*x` as mutable, as `x` is not declared as mutable
`13`	`13`	`--> $DIR/borrowck-object-mutability.rs:18:5`
Original file line number	Diff line number	Diff line change
`@@ -7,7 +7,7 @@ LL \| a.push_str("bar");`
`7`	`7`	`help: consider changing this to be a mutable reference`
`8`	`8`	`\|`
`9`	`9`	`LL \| fn foo(mut a: &mut String) {`
`10`		`- \| ~~~~~~~~~~~`
	`10`	`+ \| +++`
`11`	`11`
`12`	`12`	error[E0596]: cannot borrow `*a` as mutable, as it is behind a `&` reference
`13`	`13`	`--> $DIR/mut-arg-hint.rs:8:5`
`@@ -29,7 +29,7 @@ LL \| a.push_str("foo");`
`29`	`29`	`help: consider changing this to be a mutable reference`
`30`	`30`	`\|`
`31`	`31`	`LL \| pub fn foo(mut a: &mut String) {`
`32`		`- \| ~~~~~~~~~~~`
	`32`	`+ \| +++`
`33`	`33`
`34`	`34`	`error: aborting due to 3 previous errors`
`35`	`35`