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Auto merge of #147143 - estebank:verbose-ret-type, r=fee1-dead

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Make replacement suggestion `_` in type verbose

```
error[E0121]: the placeholder `_` is not allowed within types on item signatures for return types
  --> $DIR/in-signature.rs:6:21
   |
LL | fn arr_fn() -> [u8; _] {
   |                     ^ not allowed in type signatures
   |
help: replace with the correct return type
   |
LL - fn arr_fn() -> [u8; _] {
LL + fn arr_fn() -> [u8; 3] {
   |
```
This commit is contained in:
bors
2025-09-30 05:48:32 +00:00
parent c5dc558e6c eceb48534a
commit a2db928053
16 changed files with 258 additions and 150 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
compiler/rustc_hir_analysis/src/collect.rs
View File

@@ -1140,7 +1140,7 @@ fn recover_infer_ret_ty<'tcx>(
// recursive function definition to leak out into the fn sig.
let mut recovered_ret_ty = None;
if let Some(suggestable_ret_ty) = ret_ty.make_suggestable(tcx, false, None) {
diag.span_suggestion(
diag.span_suggestion_verbose(
infer_ret_ty.span,
"replace with the correct return type",
suggestable_ret_ty,
@@ -1152,7 +1152,7 @@ fn recover_infer_ret_ty<'tcx>(
tcx.param_env(def_id),
ret_ty,
) {
diag.span_suggestion(
diag.span_suggestion_verbose(
infer_ret_ty.span,
"replace with an appropriate return type",
sugg,

36
tests/ui/const-generics/generic_arg_infer/in-signature.stderr
View File

@@ -2,29 +2,39 @@ error[E0121]: the placeholder `_` is not allowed within types on item signatures
--> $DIR/in-signature.rs:6:21
|
LL | fn arr_fn() -> [u8; _] {
| -----^-
| | |
| | not allowed in type signatures
| help: replace with the correct return type: `[u8; 3]`
| ^ not allowed in type signatures
|
help: replace with the correct return type
|
LL - fn arr_fn() -> [u8; _] {
LL + fn arr_fn() -> [u8; 3] {
|
error[E0121]: the placeholder `_` is not allowed within types on item signatures for return types
--> $DIR/in-signature.rs:11:24
|
LL | fn ty_fn() -> Bar<i32, _> {
| ---------^-
| | |
| | not allowed in type signatures
| help: replace with the correct return type: `Bar<i32, 3>`
| ^ not allowed in type signatures
|
help: replace with the correct return type
|
LL - fn ty_fn() -> Bar<i32, _> {
LL + fn ty_fn() -> Bar<i32, 3> {
|
error[E0121]: the placeholder `_` is not allowed within types on item signatures for return types
--> $DIR/in-signature.rs:16:25
|
LL | fn ty_fn_mixed() -> Bar<_, _> {
| ----^--^-
| | | |
| | | not allowed in type signatures
| | not allowed in type signatures
| help: replace with the correct return type: `Bar<i32, 3>`
| ^ ^ not allowed in type signatures
| |
| not allowed in type signatures
|
help: replace with the correct return type
|
LL - fn ty_fn_mixed() -> Bar<_, _> {
LL + fn ty_fn_mixed() -> Bar<i32, 3> {
|
error[E0121]: the placeholder `_` is not allowed within types on item signatures for constants
--> $DIR/in-signature.rs:21:20

11
tests/ui/error-codes/E0121.stderr
View File

@@ -2,10 +2,13 @@ error[E0121]: the placeholder `_` is not allowed within types on item signatures
--> $DIR/E0121.rs:1:13
|
LL | fn foo() -> _ { 5 }
| ^
| |
| not allowed in type signatures
| help: replace with the correct return type: `i32`
| ^ not allowed in type signatures
|
help: replace with the correct return type
|
LL - fn foo() -> _ { 5 }
LL + fn foo() -> i32 { 5 }
|
error[E0121]: the placeholder `_` is not allowed within types on item signatures for static variables
--> $DIR/E0121.rs:3:13

21
tests/ui/fn/issue-80179.stderr
View File

@@ -2,21 +2,26 @@ error[E0121]: the placeholder `_` is not allowed within types on item signatures
--> $DIR/issue-80179.rs:10:24
|
LL | fn returns_fn_ptr() -> _ {
| ^
| |
| not allowed in type signatures
| help: replace with the correct return type: `fn() -> i32`
| ^ not allowed in type signatures
|
help: replace with the correct return type
|
LL - fn returns_fn_ptr() -> _ {
LL + fn returns_fn_ptr() -> fn() -> i32 {
|
error[E0121]: the placeholder `_` is not allowed within types on item signatures for return types
--> $DIR/issue-80179.rs:18:25
|
LL | fn returns_closure() -> _ {
| ^
| |
| not allowed in type signatures
| help: replace with an appropriate return type: `impl Fn() -> i32`
| ^ not allowed in type signatures
|
= note: for more information on `Fn` traits and closure types, see https://doc.rust-lang.org/book/ch13-01-closures.html
help: replace with an appropriate return type
|
LL - fn returns_closure() -> _ {
LL + fn returns_closure() -> impl Fn() -> i32 {
|
error: aborting due to 2 previous errors

30
tests/ui/fn/suggest-return-closure.stderr
View File

@@ -2,34 +2,40 @@ error[E0121]: the placeholder `_` is not allowed within types on item signatures
--> $DIR/suggest-return-closure.rs:1:17
|
LL | fn fn_once() -> _ {
| ^
| |
| not allowed in type signatures
| help: replace with an appropriate return type: `impl FnOnce()`
| ^ not allowed in type signatures
|
= note: for more information on `Fn` traits and closure types, see https://doc.rust-lang.org/book/ch13-01-closures.html
help: replace with an appropriate return type
|
LL - fn fn_once() -> _ {
LL + fn fn_once() -> impl FnOnce() {
|
error[E0121]: the placeholder `_` is not allowed within types on item signatures for return types
--> $DIR/suggest-return-closure.rs:13:16
|
LL | fn fn_mut() -> _ {
| ^
| |
| not allowed in type signatures
| help: replace with an appropriate return type: `impl FnMut(char)`
| ^ not allowed in type signatures
|
= note: for more information on `Fn` traits and closure types, see https://doc.rust-lang.org/book/ch13-01-closures.html
help: replace with an appropriate return type
|
LL - fn fn_mut() -> _ {
LL + fn fn_mut() -> impl FnMut(char) {
|
error[E0121]: the placeholder `_` is not allowed within types on item signatures for return types
--> $DIR/suggest-return-closure.rs:33:13
|
LL | fn fun() -> _ {
| ^
| |
| not allowed in type signatures
| help: replace with an appropriate return type: `impl Fn() -> i32`
| ^ not allowed in type signatures
|
= note: for more information on `Fn` traits and closure types, see https://doc.rust-lang.org/book/ch13-01-closures.html
help: replace with an appropriate return type
|
LL - fn fun() -> _ {
LL + fn fun() -> impl Fn() -> i32 {
|
error[E0596]: cannot borrow `x` as mutable, as it is not declared as mutable
--> $DIR/suggest-return-closure.rs:24:9

22
tests/ui/fn/suggest-return-future.stderr
View File

@@ -2,19 +2,25 @@ error[E0121]: the placeholder `_` is not allowed within types on item signatures
--> $DIR/suggest-return-future.rs:7:13
|
LL | fn foo() -> _ {
| ^
| |
| not allowed in type signatures
| help: replace with an appropriate return type: `impl Future<Output = i32>`
| ^ not allowed in type signatures
|
help: replace with an appropriate return type
|
LL - fn foo() -> _ {
LL + fn foo() -> impl Future<Output = i32> {
|
error[E0121]: the placeholder `_` is not allowed within types on item signatures for return types
--> $DIR/suggest-return-future.rs:15:13
|
LL | fn bar() -> _ {
| ^
| |
| not allowed in type signatures
| help: replace with an appropriate return type: `impl Future<Output = i32>`
| ^ not allowed in type signatures
|
help: replace with an appropriate return type
|
LL - fn bar() -> _ {
LL + fn bar() -> impl Future<Output = i32> {
|
error: aborting due to 2 previous errors

44
tests/ui/return/infer-return-ty-for-fn-sig-issue-125488.stderr
View File

@@ -2,37 +2,49 @@ error[E0121]: the placeholder `_` is not allowed within types on item signatures
--> $DIR/infer-return-ty-for-fn-sig-issue-125488.rs:8:24
|
LL | fn f1(s: S<'_>) -> _ {
| ^
| |
| not allowed in type signatures
| help: replace with the correct return type: `S<'_>`
| ^ not allowed in type signatures
|
help: replace with the correct return type
|
LL - fn f1(s: S<'_>) -> _ {
LL + fn f1(s: S<'_>) -> S<'_> {
|
error[E0121]: the placeholder `_` is not allowed within types on item signatures for return types
--> $DIR/infer-return-ty-for-fn-sig-issue-125488.rs:13:24
|
LL | fn f2(s: S<'_>) -> _ {
| ^
| |
| not allowed in type signatures
| help: replace with the correct return type: `S<'_>`
| ^ not allowed in type signatures
|
help: replace with the correct return type
|
LL - fn f2(s: S<'_>) -> _ {
LL + fn f2(s: S<'_>) -> S<'_> {
|
error[E0121]: the placeholder `_` is not allowed within types on item signatures for return types
--> $DIR/infer-return-ty-for-fn-sig-issue-125488.rs:23:24
|
LL | fn f3(s: S<'_>) -> _ {
| ^
| |
| not allowed in type signatures
| help: replace with the correct return type: `S<'_>`
| ^ not allowed in type signatures
|
help: replace with the correct return type
|
LL - fn f3(s: S<'_>) -> _ {
LL + fn f3(s: S<'_>) -> S<'_> {
|
error[E0121]: the placeholder `_` is not allowed within types on item signatures for return types
--> $DIR/infer-return-ty-for-fn-sig-issue-125488.rs:28:24
|
LL | fn f4(s: S<'_>) -> _ {
| ^
| |
| not allowed in type signatures
| help: replace with the correct return type: `S<'_>`
| ^ not allowed in type signatures
|
help: replace with the correct return type
|
LL - fn f4(s: S<'_>) -> _ {
LL + fn f4(s: S<'_>) -> S<'_> {
|
error: aborting due to 4 previous errors

11
tests/ui/suggestions/return-cycle-2.stderr
View File

@@ -2,10 +2,13 @@ error[E0121]: the placeholder `_` is not allowed within types on item signatures
--> $DIR/return-cycle-2.rs:6:34
|
LL | fn as_ref(_: i32, _: i32) -> _ {
| ^
| |
| not allowed in type signatures
| help: replace with the correct return type: `Token<&'static T>`
| ^ not allowed in type signatures
|
help: replace with the correct return type
|
LL - fn as_ref(_: i32, _: i32) -> _ {
LL + fn as_ref(_: i32, _: i32) -> Token<&'static T> {
|
error: aborting due to 1 previous error

11
tests/ui/suggestions/return-cycle.stderr
View File

@@ -2,10 +2,13 @@ error[E0121]: the placeholder `_` is not allowed within types on item signatures
--> $DIR/return-cycle.rs:6:17
|
LL | fn new() -> _ {
| ^
| |
| not allowed in type signatures
| help: replace with the correct return type: `Token<()>`
| ^ not allowed in type signatures
|
help: replace with the correct return type
|
LL - fn new() -> _ {
LL + fn new() -> Token<()> {
|
error: aborting due to 1 previous error

11
tests/ui/suggestions/suggest-fn-ptr-for-fn-item-in-fn-ret.stderr
View File

@@ -2,10 +2,13 @@ error[E0121]: the placeholder `_` is not allowed within types on item signatures
--> $DIR/suggest-fn-ptr-for-fn-item-in-fn-ret.rs:7:13
|
LL | fn bar() -> _ { Wrapper(foo) }
| ^
| |
| not allowed in type signatures
| help: replace with the correct return type: `Wrapper<fn()>`
| ^ not allowed in type signatures
|
help: replace with the correct return type
|
LL - fn bar() -> _ { Wrapper(foo) }
LL + fn bar() -> Wrapper<fn()> { Wrapper(foo) }
|
error: aborting due to 1 previous error

11
tests/ui/type-alias-impl-trait/issue-77179.stderr
View File

@@ -11,10 +11,13 @@ error[E0121]: the placeholder `_` is not allowed within types on item signatures
--> $DIR/issue-77179.rs:8:22
|
LL | fn test() -> Pointer<_> {
| --------^-
| | |
| | not allowed in type signatures
| help: replace with the correct return type: `Pointer<i32>`
| ^ not allowed in type signatures
|
help: replace with the correct return type
|
LL - fn test() -> Pointer<_> {
LL + fn test() -> Pointer<i32> {
|
error[E0121]: the placeholder `_` is not allowed within types on item signatures for functions
--> $DIR/issue-77179.rs:19:25

22
tests/ui/typeck/issue-80779.stderr
View File

@@ -2,19 +2,25 @@ error[E0121]: the placeholder `_` is not allowed within types on item signatures
--> $DIR/issue-80779.rs:10:28
|
LL | pub fn g(_: T<'static>) -> _ {}
| ^
| |
| not allowed in type signatures
| help: replace with the correct return type: `()`
| ^ not allowed in type signatures
|
help: replace with the correct return type
|
LL - pub fn g(_: T<'static>) -> _ {}
LL + pub fn g(_: T<'static>) -> () {}
|
error[E0121]: the placeholder `_` is not allowed within types on item signatures for return types
--> $DIR/issue-80779.rs:5:29
|
LL | pub fn f<'a>(val: T<'a>) -> _ {
| ^
| |
| not allowed in type signatures
| help: replace with the correct return type: `()`
| ^ not allowed in type signatures
|
help: replace with the correct return type
|
LL - pub fn f<'a>(val: T<'a>) -> _ {
LL + pub fn f<'a>(val: T<'a>) -> () {
|
error: aborting due to 2 previous errors

11
tests/ui/typeck/issue-98260.stderr
View File

@@ -2,10 +2,13 @@ error[E0121]: the placeholder `_` is not allowed within types on item signatures
--> $DIR/issue-98260.rs:3:27
|
LL | fn a(aa: B) -> Result<_, B> {
| -------^----
| | |
| | not allowed in type signatures
| help: replace with the correct return type: `Result<(), B>`
| ^ not allowed in type signatures
|
help: replace with the correct return type
|
LL - fn a(aa: B) -> Result<_, B> {
LL + fn a(aa: B) -> Result<(), B> {
|
error: aborting due to 1 previous error

141
tests/ui/typeck/typeck_type_placeholder_item.stderr
View File

@@ -48,20 +48,27 @@ error[E0121]: the placeholder `_` is not allowed within types on item signatures
--> $DIR/typeck_type_placeholder_item.rs:7:14
|
LL | fn test() -> _ { 5 }
| ^
| |
| not allowed in type signatures
| help: replace with the correct return type: `i32`
| ^ not allowed in type signatures
|
help: replace with the correct return type
|
LL - fn test() -> _ { 5 }
LL + fn test() -> i32 { 5 }
|
error[E0121]: the placeholder `_` is not allowed within types on item signatures for return types
--> $DIR/typeck_type_placeholder_item.rs:10:16
|
LL | fn test2() -> (_, _) { (5, 5) }
| -^--^-
| || |
| || not allowed in type signatures
| |not allowed in type signatures
| help: replace with the correct return type: `(i32, i32)`
| ^ ^ not allowed in type signatures
| |
| not allowed in type signatures
|
help: replace with the correct return type
|
LL - fn test2() -> (_, _) { (5, 5) }
LL + fn test2() -> (i32, i32) { (5, 5) }
|
error[E0121]: the placeholder `_` is not allowed within types on item signatures for static variables
--> $DIR/typeck_type_placeholder_item.rs:13:15
@@ -189,19 +196,25 @@ error[E0121]: the placeholder `_` is not allowed within types on item signatures
--> $DIR/typeck_type_placeholder_item.rs:47:26
|
LL | fn test11(x: &usize) -> &_ {
| -^
| ||
| |not allowed in type signatures
| help: replace with the correct return type: `&&usize`
| ^ not allowed in type signatures
|
help: replace with the correct return type
|
LL - fn test11(x: &usize) -> &_ {
LL + fn test11(x: &usize) -> &&usize {
|
error[E0121]: the placeholder `_` is not allowed within types on item signatures for return types
--> $DIR/typeck_type_placeholder_item.rs:52:52
|
LL | unsafe fn test12(x: *const usize) -> *const *const _ {
| --------------^
| | |
| | not allowed in type signatures
| help: replace with the correct return type: `*const *const usize`
| ^ not allowed in type signatures
|
help: replace with the correct return type
|
LL - unsafe fn test12(x: *const usize) -> *const *const _ {
LL + unsafe fn test12(x: *const usize) -> *const *const usize {
|
error[E0121]: the placeholder `_` is not allowed within types on item signatures for methods
--> $DIR/typeck_type_placeholder_item.rs:58:24
@@ -261,20 +274,27 @@ error[E0121]: the placeholder `_` is not allowed within types on item signatures
--> $DIR/typeck_type_placeholder_item.rs:80:21
|
LL | fn fn_test() -> _ { 5 }
| ^
| |
| not allowed in type signatures
| help: replace with the correct return type: `i32`
| ^ not allowed in type signatures
|
help: replace with the correct return type
|
LL - fn fn_test() -> _ { 5 }
LL + fn fn_test() -> i32 { 5 }
|
error[E0121]: the placeholder `_` is not allowed within types on item signatures for return types
--> $DIR/typeck_type_placeholder_item.rs:83:23
|
LL | fn fn_test2() -> (_, _) { (5, 5) }
| -^--^-
| || |
| || not allowed in type signatures
| |not allowed in type signatures
| help: replace with the correct return type: `(i32, i32)`
| ^ ^ not allowed in type signatures
| |
| not allowed in type signatures
|
help: replace with the correct return type
|
LL - fn fn_test2() -> (_, _) { (5, 5) }
LL + fn fn_test2() -> (i32, i32) { (5, 5) }
|
error[E0121]: the placeholder `_` is not allowed within types on item signatures for static variables
--> $DIR/typeck_type_placeholder_item.rs:86:22
@@ -374,20 +394,27 @@ error[E0121]: the placeholder `_` is not allowed within types on item signatures
--> $DIR/typeck_type_placeholder_item.rs:134:30
|
LL | fn fn_test12(x: i32) -> (_, _) { (x, x) }
| -^--^-
| || |
| || not allowed in type signatures
| |not allowed in type signatures
| help: replace with the correct return type: `(i32, i32)`
| ^ ^ not allowed in type signatures
| |
| not allowed in type signatures
|
help: replace with the correct return type
|
LL - fn fn_test12(x: i32) -> (_, _) { (x, x) }
LL + fn fn_test12(x: i32) -> (i32, i32) { (x, x) }
|
error[E0121]: the placeholder `_` is not allowed within types on item signatures for return types
--> $DIR/typeck_type_placeholder_item.rs:137:33
|
LL | fn fn_test13(x: _) -> (i32, _) { (x, x) }
| ------^-
| | |
| | not allowed in type signatures
| help: replace with the correct return type: `(i32, i32)`
| ^ not allowed in type signatures
|
help: replace with the correct return type
|
LL - fn fn_test13(x: _) -> (i32, _) { (x, x) }
LL + fn fn_test13(x: _) -> (i32, i32) { (x, x) }
|
error[E0121]: the placeholder `_` is not allowed within types on item signatures for methods
--> $DIR/typeck_type_placeholder_item.rs:142:31
@@ -528,10 +555,13 @@ error[E0121]: the placeholder `_` is not allowed within types on item signatures
--> $DIR/typeck_type_placeholder_item.rs:226:31
|
LL | fn value() -> Option<&'static _> {
| ----------------^-
| | |
| | not allowed in type signatures
| help: replace with the correct return type: `Option<&'static u8>`
| ^ not allowed in type signatures
|
help: replace with the correct return type
|
LL - fn value() -> Option<&'static _> {
LL + fn value() -> Option<&'static u8> {
|
error[E0121]: the placeholder `_` is not allowed within types on item signatures for constants
--> $DIR/typeck_type_placeholder_item.rs:231:17
@@ -549,10 +579,13 @@ error[E0121]: the placeholder `_` is not allowed within types on item signatures
--> $DIR/typeck_type_placeholder_item.rs:235:31
|
LL | fn evens_squared(n: usize) -> _ {
| ^
| |
| not allowed in type signatures
| help: replace with an appropriate return type: `impl Iterator<Item = usize>`
| ^ not allowed in type signatures
|
help: replace with an appropriate return type
|
LL - fn evens_squared(n: usize) -> _ {
LL + fn evens_squared(n: usize) -> impl Iterator<Item = usize> {
|
error[E0121]: the placeholder `_` is not allowed within types on item signatures for constants
--> $DIR/typeck_type_placeholder_item.rs:240:10
@@ -570,10 +603,13 @@ error[E0121]: the placeholder `_` is not allowed within types on item signatures
--> $DIR/typeck_type_placeholder_item.rs:40:24
|
LL | fn test9(&self) -> _ { () }
| ^
| |
| not allowed in type signatures
| help: replace with the correct return type: `()`
| ^ not allowed in type signatures
|
help: replace with the correct return type
|
LL - fn test9(&self) -> _ { () }
LL + fn test9(&self) -> () { () }
|
error[E0121]: the placeholder `_` is not allowed within types on item signatures for methods
--> $DIR/typeck_type_placeholder_item.rs:43:27
@@ -585,10 +621,13 @@ error[E0121]: the placeholder `_` is not allowed within types on item signatures
--> $DIR/typeck_type_placeholder_item.rs:107:31
|
LL | fn fn_test9(&self) -> _ { () }
| ^
| |
| not allowed in type signatures
| help: replace with the correct return type: `()`
| ^ not allowed in type signatures
|
help: replace with the correct return type
|
LL - fn fn_test9(&self) -> _ { () }
LL + fn fn_test9(&self) -> () { () }
|
error[E0121]: the placeholder `_` is not allowed within types on item signatures for methods
--> $DIR/typeck_type_placeholder_item.rs:110:34

11
tests/ui/typeck/typeck_type_placeholder_item_help.stderr
View File

@@ -2,10 +2,13 @@ error[E0121]: the placeholder `_` is not allowed within types on item signatures
--> $DIR/typeck_type_placeholder_item_help.rs:4:15
|
LL | fn test1() -> _ { Some(42) }
| ^
| |
| not allowed in type signatures
| help: replace with the correct return type: `Option<i32>`
| ^ not allowed in type signatures
|
help: replace with the correct return type
|
LL - fn test1() -> _ { Some(42) }
LL + fn test1() -> Option<i32> { Some(42) }
|
error[E0121]: the placeholder `_` is not allowed within types on item signatures for constants
--> $DIR/typeck_type_placeholder_item_help.rs:7:14

11
tests/ui/variance/leaking-unnameables.stderr
View File

@@ -2,10 +2,13 @@ error[E0121]: the placeholder `_` is not allowed within types on item signatures
--> $DIR/leaking-unnameables.rs:8:18
|
LL | pub fn f<T>() -> _ {
| ^
| |
| not allowed in type signatures
| help: replace with the correct return type: `fn()`
| ^ not allowed in type signatures
|
help: replace with the correct return type
|
LL - pub fn f<T>() -> _ {
LL + pub fn f<T>() -> fn() {
|
error: aborting due to 1 previous error