Rollup merge of #75509 - estebank:coming-merrily-from-java-land, r=lcnr

Tweak suggestion for `this` -> `self`

* When referring to `this` in associated `fn`s always suggest `self`.
* Point at ident for `fn` lacking `self`
* Suggest adding `self` to assoc `fn`s when appropriate

_Improvements based on the narrative in https://fasterthanli.me/articles/i-am-a-java-csharp-c-or-cplusplus-dev-time-to-do-some-rust_

2 files changed, 32 insertions, 12 deletions

diff --git a/src/test/ui/error-codes/E0424.rs b/src/test/ui/error-codes/E0424.rs
index 3c6a1d4f88f..fa0c86ecf48 100644
--- a/src/test/ui/error-codes/E0424.rs
+++ b/src/test/ui/error-codes/E0424.rs
@@ -6,6 +6,10 @@ impl Foo {
     fn foo() {
         self.bar(); //~ ERROR E0424
     }
+
+    fn baz(_: i32) {
+        self.bar(); //~ ERROR E0424
+    }
 }
 
 fn main () {
diff --git a/src/test/ui/error-codes/E0424.stderr b/src/test/ui/error-codes/E0424.stderr
index 690a101496d..9b8a29e8272 100644
--- a/src/test/ui/error-codes/E0424.stderr
+++ b/src/test/ui/error-codes/E0424.stderr
@@ -1,21 +1,37 @@
 error[E0424]: expected value, found module `self`
   --> $DIR/E0424.rs:7:9
    |
-LL | /     fn foo() {
-LL | |         self.bar();
-   | |         ^^^^ `self` value is a keyword only available in methods with a `self` parameter
-LL | |     }
-   | |_____- this function doesn't have a `self` parameter
+LL |     fn foo() {
+   |        --- this function doesn't have a `self` parameter
+LL |         self.bar();
+   |         ^^^^ `self` value is a keyword only available in methods with a `self` parameter
+   |
+help: add a `self` receiver parameter to make the associated `fn` a method
+   |
+LL |     fn foo(&self) {
+   |            ^^^^^
+
+error[E0424]: expected value, found module `self`
+  --> $DIR/E0424.rs:11:9
+   |
+LL |     fn baz(_: i32) {
+   |        --- this function doesn't have a `self` parameter
+LL |         self.bar();
+   |         ^^^^ `self` value is a keyword only available in methods with a `self` parameter
+   |
+help: add a `self` receiver parameter to make the associated `fn` a method
+   |
+LL |     fn baz(&self, _: i32) {
+   |            ^^^^^^
 
 error[E0424]: expected unit struct, unit variant or constant, found module `self`
-  --> $DIR/E0424.rs:12:9
+  --> $DIR/E0424.rs:16:9
    |
-LL | / fn main () {
-LL | |     let self = "self";
-   | |         ^^^^ `self` value is a keyword and may not be bound to variables or shadowed
-LL | | }
-   | |_- this function doesn't have a `self` parameter
+LL | fn main () {
+   |    ---- this function can't have a `self` parameter
+LL |     let self = "self";
+   |         ^^^^ `self` value is a keyword and may not be bound to variables or shadowed
 
-error: aborting due to 2 previous errors
+error: aborting due to 3 previous errors
 
 For more information about this error, try `rustc --explain E0424`.