Auto merge of #76612 - estebank:pat-missing-fields-suggestion, r=davidtwco

Provide suggestion for missing fields in patterns

src/test/ui/error-codes/E0027-teach.rs

@@ -1,15 +0,0 @@
-// compile-flags: -Z teach
-
-struct Dog {
-    name: String,
-    age: u32,
-}
-
-fn main() {
-    let d = Dog { name: "Rusty".to_string(), age: 8 };
-
-    match d {
-        Dog { age: x } => {}
-        //~^ ERROR pattern does not mention field `name`
-    }
-}

src/test/ui/error-codes/E0027-teach.stderr

@@ -1,11 +0,0 @@
-error[E0027]: pattern does not mention field `name`
-  --> $DIR/E0027-teach.rs:12:9
-   |
-LL |         Dog { age: x } => {}
-   |         ^^^^^^^^^^^^^^ missing field `name`
-   |
-   = note: This error indicates that a pattern for a struct fails to specify a sub-pattern for every one of the struct's fields. Ensure that each field from the struct's definition is mentioned in the pattern, or use `..` to ignore unwanted fields.
-
-error: aborting due to previous error
-
-For more information about this error, try `rustc --explain E0027`.

src/test/ui/error-codes/E0027.rs

@@ -7,7 +7,9 @@ fn main() {
     let d = Dog { name: "Rusty".to_string(), age: 8 };
 
     match d {
-        Dog { age: x } => {}
-        //~^ ERROR pattern does not mention field `name`
+        Dog { age: x } => {} //~ ERROR pattern does not mention field `name`
+    }
+    match d {
+        Dog {} => {} //~ ERROR pattern does not mention fields `name`, `age`
     }
 }

src/test/ui/error-codes/E0027.stderr

@@ -3,7 +3,31 @@ error[E0027]: pattern does not mention field `name`
    |
 LL |         Dog { age: x } => {}
    |         ^^^^^^^^^^^^^^ missing field `name`
+   |
+help: include the missing field in the pattern
+   |
+LL |         Dog { age: x, name } => {}
+   |                     ^^^^^^
+help: if you don't care about this missing field, you can explicitely ignore it
+   |
+LL |         Dog { age: x, .. } => {}
+   |                     ^^^^
 
-error: aborting due to previous error
+error[E0027]: pattern does not mention fields `name`, `age`
+  --> $DIR/E0027.rs:13:9
+   |
+LL |         Dog {} => {}
+   |         ^^^^^^ missing fields `name`, `age`
+   |
+help: include the missing fields in the pattern
+   |
+LL |         Dog { name, age } => {}
+   |             ^^^^^^^^^^^^^
+help: if you don't care about these missing fields, you can explicitely ignore them
+   |
+LL |         Dog { .. } => {}
+   |             ^^^^^^
+
+error: aborting due to 2 previous errors
 
 For more information about this error, try `rustc --explain E0027`.

src/test/ui/structs/struct-field-cfg.stderr

@@ -17,6 +17,15 @@ error[E0027]: pattern does not mention field `present`
    |
 LL |     let Foo { #[cfg(any())] present: () } = foo;
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ missing field `present`
+   |
+help: include the missing field in the pattern
+   |
+LL |     let Foo { present } = foo;
+   |             ^^^^^^^^^^^
+help: if you don't care about this missing field, you can explicitely ignore it
+   |
+LL |     let Foo { .. } = foo;
+   |             ^^^^^^
 
 error[E0026]: struct `Foo` does not have a field named `absent`
   --> $DIR/struct-field-cfg.rs:16:42

src/test/ui/structs/struct-pat-derived-error.stderr

@@ -15,6 +15,15 @@ error[E0027]: pattern does not mention fields `b`, `c`
    |
 LL |         let A { x, y } = self.d;
    |             ^^^^^^^^^^ missing fields `b`, `c`
+   |
+help: include the missing fields in the pattern
+   |
+LL |         let A { x, y, b, c } = self.d;
+   |                     ^^^^^^
+help: if you don't care about these missing fields, you can explicitely ignore them
+   |
+LL |         let A { x, y, .. } = self.d;
+   |                     ^^^^
 
 error: aborting due to 3 previous errors