refactor and fix this-expression-has-type note

Centril · Centril · commit d7e2f3aee550 · 2019-12-30T14:05:17.000+01:00
diff --git a/src/librustc/infer/error_reporting/mod.rs b/src/librustc/infer/error_reporting/mod.rs
@@ -582,6 +582,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
     ) {
         match cause.code {
             ObligationCauseCode::Pattern { span, ty } => {
+                let ty = self.resolve_vars_if_possible(&ty);
                 if ty.is_suggestable() {
                     // don't show type `_`
                     err.span_label(span, format!("this expression has type `{}`", ty));
diff --git a/src/librustc_typeck/check/pat.rs b/src/librustc_typeck/check/pat.rs
diff --git a/src/test/ui/destructure-trait-ref.stderr b/src/test/ui/destructure-trait-ref.stderr
@@ -44,7 +44,9 @@ error[E0308]: mismatched types
   --> $DIR/destructure-trait-ref.rs:42:13
    |
 LL |     let box box x = box 1isize as Box<dyn T>;
-   |             ^^^^^ expected trait `T`, found struct `std::boxed::Box`
+   |             ^^^^^   ------------------------ this expression has type `std::boxed::Box<dyn T>`
+   |             |
+   |             expected trait `T`, found struct `std::boxed::Box`
    |
    = note: expected trait object `dyn T`
                     found struct `std::boxed::Box<_>`
diff --git a/src/test/ui/exclusive-range/exclusive_range_pattern_syntax_collision.stderr b/src/test/ui/exclusive-range/exclusive_range_pattern_syntax_collision.stderr
@@ -8,7 +8,7 @@ error[E0308]: mismatched types
   --> $DIR/exclusive_range_pattern_syntax_collision.rs:5:13
    |
 LL |     match [5..4, 99..105, 43..44] {
-   |           ----------------------- this expression has type `std::ops::Range<{integer}>`
+   |           ----------------------- this expression has type `[std::ops::Range<{integer}>; 3]`
 LL |         [_, 99.., _] => {},
    |             ^^ expected struct `std::ops::Range`, found integer
    |
diff --git a/src/test/ui/exclusive-range/exclusive_range_pattern_syntax_collision2.stderr b/src/test/ui/exclusive-range/exclusive_range_pattern_syntax_collision2.stderr
@@ -14,7 +14,7 @@ error[E0308]: mismatched types
   --> $DIR/exclusive_range_pattern_syntax_collision2.rs:5:13
    |
 LL |     match [5..4, 99..105, 43..44] {
-   |           ----------------------- this expression has type `std::ops::Range<{integer}>`
+   |           ----------------------- this expression has type `[std::ops::Range<{integer}>; 3]`
 LL |         [_, 99..] => {},
    |             ^^ expected struct `std::ops::Range`, found integer
    |
diff --git a/src/test/ui/exclusive-range/exclusive_range_pattern_syntax_collision3.stderr b/src/test/ui/exclusive-range/exclusive_range_pattern_syntax_collision3.stderr
@@ -8,7 +8,7 @@ error[E0308]: mismatched types
   --> $DIR/exclusive_range_pattern_syntax_collision3.rs:5:12
    |
 LL |     match [5..4, 99..105, 43..44] {
-   |           ----------------------- this expression has type `std::ops::Range<{integer}>`
+   |           ----------------------- this expression has type `[std::ops::Range<{integer}>; 3]`
 LL |         [..9, 99..100, _] => {},
    |            ^ expected struct `std::ops::Range`, found integer
    |
@@ -19,7 +19,7 @@ error[E0308]: mismatched types
   --> $DIR/exclusive_range_pattern_syntax_collision3.rs:5:15
    |
 LL |     match [5..4, 99..105, 43..44] {
-   |           ----------------------- this expression has type `std::ops::Range<{integer}>`
+   |           ----------------------- this expression has type `[std::ops::Range<{integer}>; 3]`
 LL |         [..9, 99..100, _] => {},
    |               ^^  --- this is of type `{integer}`
    |               |
@@ -32,7 +32,7 @@ error[E0308]: mismatched types
   --> $DIR/exclusive_range_pattern_syntax_collision3.rs:5:19
    |
 LL |     match [5..4, 99..105, 43..44] {
-   |           ----------------------- this match expression has type `std::ops::Range<{integer}>`
+   |           ----------------------- this expression has type `[std::ops::Range<{integer}>; 3]`
 LL |         [..9, 99..100, _] => {},
    |               --  ^^^ expected struct `std::ops::Range`, found integer
    |               |
diff --git a/src/test/ui/issues/issue-15896.stderr b/src/test/ui/issues/issue-15896.stderr
@@ -2,7 +2,7 @@ error[E0308]: mismatched types
   --> $DIR/issue-15896.rs:11:11
    |
 LL |     let u = match e {
-   |                   - this expression has type `main::R`
+   |                   - this expression has type `main::E`
 LL |         E::B(
 LL |           Tau{t: x},
    |           ^^^^^^^^^ expected enum `main::R`, found struct `main::Tau`
diff --git a/src/test/ui/issues/issue-16338.stderr b/src/test/ui/issues/issue-16338.stderr
@@ -2,7 +2,7 @@ error[E0308]: mismatched types
   --> $DIR/issue-16338.rs:7:9
    |
 LL |     let Slice { data: data, len: len } = "foo";
-   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^   ----- this expression has type `str`
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^   ----- this expression has type `&str`
    |         |
    |         expected `str`, found struct `Slice`
    |
diff --git a/src/test/ui/mismatched_types/E0409.stderr b/src/test/ui/mismatched_types/E0409.stderr
@@ -9,6 +9,8 @@ LL |         (0, ref y) | (y, 0) => {}
 error[E0308]: mismatched types
   --> $DIR/E0409.rs:5:23
    |
+LL |     match x {
+   |           - this expression has type `({integer}, {integer})`
 LL |         (0, ref y) | (y, 0) => {}
    |                       ^ expected `&{integer}`, found integer
 
diff --git a/src/test/ui/or-patterns/already-bound-name.stderr b/src/test/ui/or-patterns/already-bound-name.stderr
@@ -94,7 +94,9 @@ error[E0308]: mismatched types
   --> $DIR/already-bound-name.rs:33:31
    |
 LL |     let B(A(a, _) | B(a)) | A(a, A(a, _) | B(a)) = B(B(1));
-   |                               ^ expected integer, found enum `E`
+   |                               ^                    ------- this expression has type `E<E<{integer}>>`
+   |                               |
+   |                               expected integer, found enum `E`
    |
    = note: expected type `{integer}`
               found type `E<{integer}>`
diff --git a/src/test/ui/or-patterns/inconsistent-modes.stderr b/src/test/ui/or-patterns/inconsistent-modes.stderr
@@ -60,7 +60,9 @@ error[E0308]: mismatched types
   --> $DIR/inconsistent-modes.rs:13:25
    |
 LL |     let Ok(ref a) | Err(ref mut a): Result<&u8, &mut u8> = Ok(&0);
-   |                         ^^^^^^^^^ types differ in mutability
+   |                         ^^^^^^^^^                          ------ this expression has type `std::result::Result<&u8, &mut u8>`
+   |                         |
+   |                         types differ in mutability
    |
    = note: expected type `&&u8`
               found type `&mut &mut u8`
@@ -69,7 +71,9 @@ error[E0308]: mismatched types
   --> $DIR/inconsistent-modes.rs:16:31
    |
 LL |     let Ok((ref a, b)) | Err((ref mut a, ref b)) = Ok((0, &0));
-   |                               ^^^^^^^^^ types differ in mutability
+   |                               ^^^^^^^^^            ----------- this expression has type `std::result::Result<({integer}, &{integer}), (_, _)>`
+   |                               |
+   |                               types differ in mutability
    |
    = note: expected type `&{integer}`
               found type `&mut _`
diff --git a/src/test/ui/or-patterns/or-pattern-mismatch.stderr b/src/test/ui/or-patterns/or-pattern-mismatch.stderr
@@ -2,7 +2,7 @@ error[E0308]: mismatched types
   --> $DIR/or-pattern-mismatch.rs:3:68
    |
 LL | fn main() { match Blah::A(1, 1, 2) { Blah::A(_, x, y) | Blah::B(x, y) => { } } }
-   |                                                                    ^ expected `usize`, found `isize`
+   |                   ---------------- this expression has type `Blah` ^ expected `usize`, found `isize`
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/parser/recover-range-pats.stderr b/src/test/ui/parser/recover-range-pats.stderr
@@ -425,8 +425,9 @@ error[E0308]: mismatched types
   --> $DIR/recover-range-pats.rs:23:16
    |
 LL |     if let X.. .0 = 0 {}
-   |            -   ^^ expected integer, found floating-point number
-   |            |
+   |            -   ^^   - this expression has type `u8`
+   |            |   |
+   |            |   expected integer, found floating-point number
    |            this is of type `u8`
 
 error[E0029]: only char and numeric types are allowed in range patterns
@@ -457,8 +458,9 @@ error[E0308]: mismatched types
   --> $DIR/recover-range-pats.rs:36:16
    |
 LL |     if let X..=.0 = 0 {}
-   |            -   ^^ expected integer, found floating-point number
-   |            |
+   |            -   ^^   - this expression has type `u8`
+   |            |   |
+   |            |   expected integer, found floating-point number
    |            this is of type `u8`
 
 error[E0029]: only char and numeric types are allowed in range patterns
@@ -489,8 +491,9 @@ error[E0308]: mismatched types
   --> $DIR/recover-range-pats.rs:52:17
    |
 LL |     if let X... .0 = 0 {}
-   |            -    ^^ expected integer, found floating-point number
-   |            |
+   |            -    ^^   - this expression has type `u8`
+   |            |    |
+   |            |    expected integer, found floating-point number
    |            this is of type `u8`
 
 error[E0029]: only char and numeric types are allowed in range patterns
diff --git a/src/test/ui/pattern/pat-struct-field-expr-has-type.stderr b/src/test/ui/pattern/pat-struct-field-expr-has-type.stderr
@@ -2,7 +2,7 @@ error[E0308]: mismatched types
   --> $DIR/pat-struct-field-expr-has-type.rs:7:16
    |
 LL |     match (S { f: 42 }) {
-   |           ------------- this expression has type `u8`
+   |           ------------- this expression has type `S`
 LL |         S { f: Ok(_) } => {}
    |                ^^^^^ expected `u8`, found enum `std::result::Result`
    |
diff --git a/src/test/ui/pattern/pattern-tyvar.stderr b/src/test/ui/pattern/pattern-tyvar.stderr
@@ -2,7 +2,7 @@ error[E0308]: mismatched types
   --> $DIR/pattern-tyvar.rs:5:18
    |
 LL |     match t {
-   |           - this expression has type `std::option::Option<std::vec::Vec<isize>>`
+   |           - this expression has type `Bar`
 LL |       Bar::T1(_, Some::<isize>(x)) => {
    |                  ^^^^^^^^^^^^^^^^ expected struct `std::vec::Vec`, found `isize`
    |
diff --git a/src/test/ui/resolve/resolve-inconsistent-binding-mode.stderr b/src/test/ui/resolve/resolve-inconsistent-binding-mode.stderr
@@ -23,18 +23,24 @@ LL |       Opts::A(ref mut i) | Opts::B(ref i) => {}
 error[E0308]: mismatched types
   --> $DIR/resolve-inconsistent-binding-mode.rs:7:32
    |
+LL |     match x {
+   |           - this expression has type `Opts`
 LL |       Opts::A(ref i) | Opts::B(i) => {}
    |                                ^ expected `&isize`, found `isize`
 
 error[E0308]: mismatched types
   --> $DIR/resolve-inconsistent-binding-mode.rs:16:32
    |
+LL |     match x {
+   |           - this expression has type `Opts`
 LL |       Opts::A(ref i) | Opts::B(i) => {}
    |                                ^ expected `&isize`, found `isize`
 
 error[E0308]: mismatched types
   --> $DIR/resolve-inconsistent-binding-mode.rs:25:36
    |
+LL |     match x {
+   |           - this expression has type `Opts`
 LL |       Opts::A(ref mut i) | Opts::B(ref i) => {}
    |                                    ^^^^^ types differ in mutability
    |
diff --git a/src/test/ui/resolve/resolve-inconsistent-names.stderr b/src/test/ui/resolve/resolve-inconsistent-names.stderr
@@ -86,6 +86,8 @@ LL |         (CONST1, _) | (_, Const2) => ()
 error[E0308]: mismatched types
   --> $DIR/resolve-inconsistent-names.rs:19:19
    |
+LL |     match x {
+   |           - this expression has type `(E, E)`
 LL |         (A, B) | (ref B, c) | (c, A) => ()
    |                   ^^^^^ expected enum `E`, found `&E`
 
diff --git a/src/test/ui/rfc-2497-if-let-chains/disallowed-positions.stderr b/src/test/ui/rfc-2497-if-let-chains/disallowed-positions.stderr
@@ -697,7 +697,7 @@ error[E0308]: mismatched types
   --> $DIR/disallowed-positions.rs:86:12
    |
 LL |     if let Range { start: true, end } = t..&&false {}
-   |            ^^^^^^^^^^^^^^^^^^^^^^^^^^   - this expression has type `bool`
+   |            ^^^^^^^^^^^^^^^^^^^^^^^^^^   - this expression has type `&&bool`
    |            |
    |            expected `bool`, found struct `std::ops::Range`
    |
@@ -885,7 +885,7 @@ error[E0308]: mismatched types
   --> $DIR/disallowed-positions.rs:150:15
    |
 LL |     while let Range { start: true, end } = t..&&false {}
-   |               ^^^^^^^^^^^^^^^^^^^^^^^^^^   - this expression has type `bool`
+   |               ^^^^^^^^^^^^^^^^^^^^^^^^^^   - this expression has type `&&bool`
    |               |
    |               expected `bool`, found struct `std::ops::Range`
    |

Original file line number	Diff line number	Diff line change
`@@ -44,7 +44,9 @@ error[E0308]: mismatched types`
`44`	`44`	`--> $DIR/destructure-trait-ref.rs:42:13`
`45`	`45`	`\|`
`46`	`46`	`LL \| let box box x = box 1isize as Box<dyn T>;`
`47`		- \| ^^^^^ expected trait `T`, found struct `std::boxed::Box`
	`47`	+ \| ^^^^^ ------------------------ this expression has type `std::boxed::Box<dyn T>`
	`48`	`+ \| \|`
	`49`	+ \| expected trait `T`, found struct `std::boxed::Box`
`48`	`50`	`\|`
`49`	`51`	= note: expected trait object `dyn T`
`50`	`52`	found struct `std::boxed::Box<_>`
Original file line number	Diff line number	Diff line change
`@@ -8,7 +8,7 @@ error[E0308]: mismatched types`
`8`	`8`	`--> $DIR/exclusive_range_pattern_syntax_collision.rs:5:13`
`9`	`9`	`\|`
`10`	`10`	`LL \| match [5..4, 99..105, 43..44] {`
`11`		- \| ----------------------- this expression has type `std::ops::Range<{integer}>`
	`11`	+ \| ----------------------- this expression has type `[std::ops::Range<{integer}>; 3]`
`12`	`12`	`LL \| [_, 99.., _] => {},`
`13`	`13`	\| ^^ expected struct `std::ops::Range`, found integer
`14`	`14`	`\|`
Original file line number	Diff line number	Diff line change
`@@ -14,7 +14,7 @@ error[E0308]: mismatched types`
`14`	`14`	`--> $DIR/exclusive_range_pattern_syntax_collision2.rs:5:13`
`15`	`15`	`\|`
`16`	`16`	`LL \| match [5..4, 99..105, 43..44] {`
`17`		- \| ----------------------- this expression has type `std::ops::Range<{integer}>`
	`17`	+ \| ----------------------- this expression has type `[std::ops::Range<{integer}>; 3]`
`18`	`18`	`LL \| [_, 99..] => {},`
`19`	`19`	\| ^^ expected struct `std::ops::Range`, found integer
`20`	`20`	`\|`
Original file line number	Diff line number	Diff line change
`@@ -2,7 +2,7 @@ error[E0308]: mismatched types`
`2`	`2`	`--> $DIR/issue-15896.rs:11:11`
`3`	`3`	`\|`
`4`	`4`	`LL \| let u = match e {`
`5`		- \| - this expression has type `main::R`
	`5`	+ \| - this expression has type `main::E`
`6`	`6`	`LL \| E::B(`
`7`	`7`	`LL \| Tau{t: x},`
`8`	`8`	\| ^^^^^^^^^ expected enum `main::R`, found struct `main::Tau`
Original file line number	Diff line number	Diff line change
`@@ -2,7 +2,7 @@ error[E0308]: mismatched types`
`2`	`2`	`--> $DIR/issue-16338.rs:7:9`
`3`	`3`	`\|`
`4`	`4`	`LL \| let Slice { data: data, len: len } = "foo";`
`5`		- \| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ----- this expression has type `str`
	`5`	+ \| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ----- this expression has type `&str`
`6`	`6`	`\| \|`
`7`	`7`	\| expected `str`, found struct `Slice`
`8`	`8`	`\|`
Original file line number	Diff line number	Diff line change
`@@ -9,6 +9,8 @@ LL \| (0, ref y) \| (y, 0) => {}`
`9`	`9`	`error[E0308]: mismatched types`
`10`	`10`	`--> $DIR/E0409.rs:5:23`
`11`	`11`	`\|`
	`12`	`+LL \| match x {`
	`13`	+ \| - this expression has type `({integer}, {integer})`
`12`	`14`	`LL \| (0, ref y) \| (y, 0) => {}`
`13`	`15`	\| ^ expected `&{integer}`, found integer
`14`	`16`
Original file line number	Diff line number	Diff line change
`@@ -94,7 +94,9 @@ error[E0308]: mismatched types`
`94`	`94`	`--> $DIR/already-bound-name.rs:33:31`
`95`	`95`	`\|`
`96`	`96`	`LL \| let B(A(a, _) \| B(a)) \| A(a, A(a, _) \| B(a)) = B(B(1));`
`97`		- \| ^ expected integer, found enum `E`
	`97`	+ \| ^ ------- this expression has type `E<E<{integer}>>`
	`98`	`+ \| \|`
	`99`	+ \| expected integer, found enum `E`
`98`	`100`	`\|`
`99`	`101`	= note: expected type `{integer}`
`100`	`102`	found type `E<{integer}>`