Rollup merge of #99903 - gimbles:pub, r=davidtwco

Add diagnostic when using public instead of pub

Forwarding from #99706

I accidentally broke something(??) in git and the commits in that PR are absolutely not what I did in that branch

Anyways, this is the PR for this now. Adding tests again in a minute.

cc `@davidtwco`

compiler/rustc_parse/src/parser/diagnostics.rs

@@ -601,6 +601,17 @@ impl<'a> Parser<'a> {
  self.last_unexpected_token_span = Some(self.token.span);
  let mut err = self.struct_span_err(self.token.span, &msg_exp);
 
+ if let TokenKind::Ident(symbol, _) = &self.prev_token.kind {
+ if symbol.as_str() == "public" {
+ err.span_suggestion_short(
+ self.prev_token.span,
+ "write `pub` instead of `public` to make the item public",
+ "pub",
+ appl,
+ );
+ }
+ }
+
  // Add suggestion for a missing closing angle bracket if '>' is included in expected_tokens
  // there are unclosed angle brackets
  if self.unmatched_angle_bracket_count > 0

src/test/ui/parser/public-instead-of-pub.fixed

@@ -0,0 +1,8 @@
+// Checks what happens when `public` is used instead of the correct, `pub`
+// edition:2018
+// run-rustfix
+pub struct X;
+//~^ ERROR expected one of `!` or `::`, found keyword `struct`
+//~^^ HELP write `pub` instead of `public` to make the item public
+
+fn main() {}

src/test/ui/parser/public-instead-of-pub.rs

@@ -0,0 +1,8 @@
+// Checks what happens when `public` is used instead of the correct, `pub`
+// edition:2018
+// run-rustfix
+public struct X;
+//~^ ERROR expected one of `!` or `::`, found keyword `struct`
+//~^^ HELP write `pub` instead of `public` to make the item public
+
+fn main() {}

src/test/ui/parser/public-instead-of-pub.stderr

@@ -0,0 +1,13 @@
+error: expected one of `!` or `::`, found keyword `struct`
+ --> $DIR/public-instead-of-pub.rs:4:8
+ |
+LL | public struct X;
+ | ^^^^^^ expected one of `!` or `::`
+ |
+help: write `pub` instead of `public` to make the item public
+ |
+LL | pub struct X;
+ | ~~~
+
+error: aborting due to previous error
+