Auto merge of rust-lang#59031 - estebank:recover-from-comaless, r=petrochenkov

Recover from missing comma between enum variants and from bad `pub` kw Fix rust-lang#56579. Fix rust-lang#56473.

Author: bors

src/libsyntax/parse/parser.rs

@@ -1524,7 +1524,7 @@ impl<'a> Parser<'a> {
  at_end: &mut bool,
  mut attrs: Vec<Attribute>) -> PResult<'a, TraitItem> {
  let lo = self.span;
-
+ self.eat_bad_pub();
  let (name, node, generics) = if self.eat_keyword(keywords::Type) {
  self.parse_trait_item_assoc_ty()?
  } else if self.is_const_item() {
@@ -7688,6 +7688,7 @@ impl<'a> Parser<'a> {
 
  let struct_def;
  let mut disr_expr = None;
+ self.eat_bad_pub();
  let ident = self.parse_ident()?;
  if self.check(&token::OpenDelim(token::Brace)) {
  // Parse a struct variant.
@@ -7719,11 +7720,25 @@ impl<'a> Parser<'a> {
  };
  variants.push(respan(vlo.to(self.prev_span), vr));
 
- if !self.eat(&token::Comma) { break; }
+ if !self.eat(&token::Comma) {
+ if self.token.is_ident() && !self.token.is_reserved_ident() {
+ let sp = self.sess.source_map().next_point(self.prev_span);
+ let mut err = self.struct_span_err(sp, "missing comma");
+ err.span_suggestion_short(
+ sp,
+ "missing comma",
+ ",".to_owned(),
+ Applicability::MaybeIncorrect,
+ );
+ err.emit();
+ } else {
+ break;
+ }
+ }
  }
  self.expect(&token::CloseDelim(token::Brace))?;
  if !any_disr.is_empty() && !all_nullary {
- let mut err =self.struct_span_err(
+ let mut err = self.struct_span_err(
  any_disr.clone(),
  "discriminator values can only be used with a field-less enum",
  );
@@ -8608,6 +8623,21 @@ impl<'a> Parser<'a> {
  Applicability::MaybeIncorrect,
  ).emit();
  }
+
+ /// Recover from `pub` keyword in places where it seems _reasonable_ but isn't valid.
+ fn eat_bad_pub(&mut self) {
+ if self.token.is_keyword(keywords::Pub) {
+ match self.parse_visibility(false) {
+ Ok(vis) => {
+ let mut err = self.diagnostic()
+ .struct_span_err(vis.span, "unnecessary visibility qualifier");
+ err.span_label(vis.span, "`pub` not permitted here");
+ err.emit();
+ }
+ Err(mut err) => err.emit(),
+ }
+ }
+ }
 }
 
 pub fn emit_unclosed_delims(unclosed_delims: &mut Vec<UnmatchedBrace>, handler: &errors::Handler) {

src/test/ui/issues/issue-28433.rs

@@ -1,13 +1,14 @@
 // compile-flags: -Z continue-parse-after-error
 
-enum bird {
- pub duck,
- //~^ ERROR: expected identifier, found keyword `pub`
- //~| ERROR: expected
- goose
+enum Bird {
+ pub Duck,
+ //~^ ERROR unnecessary visibility qualifier
+ Goose,
+ pub(crate) Dove
+ //~^ ERROR unnecessary visibility qualifier
 }
 
 
 fn main() {
- let y = bird::goose;
+ let y = Bird::Goose;
 }

src/test/ui/issues/issue-28433.stderr

@@ -1,18 +1,14 @@
-error: expected identifier, found keyword `pub`
+error: unnecessary visibility qualifier
  --> $DIR/issue-28433.rs:4:5
  |
-LL | pub duck,
- | ^^^ expected identifier, found keyword
-help: you can escape reserved keywords to use them as identifiers
- |
-LL | r#pub duck,
- | ^^^^^
+LL | pub Duck,
+ | ^^^ `pub` not permitted here
 
-error: expected one of `(`, `,`, `=`, `{`, or `}`, found `duck`
- --> $DIR/issue-28433.rs:4:9
+error: unnecessary visibility qualifier
+ --> $DIR/issue-28433.rs:7:5
  |
-LL | pub duck,
- |  ^^^^ expected one of `(`, `,`, `=`, `{`, or `}` here
+LL | pub(crate) Dove
+ | ^^^^^^^^^^ `pub` not permitted here
 
 error: aborting due to 2 previous errors
 

src/test/ui/parser/recover-enum.rs

@@ -3,7 +3,11 @@
 fn main() {
  enum Test {
  Very
- Bad //~ ERROR found `Bad`
- Stuff
+ //~^ ERROR missing comma
+ Bad(usize)
+ //~^ ERROR missing comma
+ Stuff { a: usize }
+ //~^ ERROR missing comma
+ Here
  }
 }

src/test/ui/parser/recover-enum.stderr

@@ -1,10 +1,20 @@
-error: expected one of `(`, `,`, `=`, `{`, or `}`, found `Bad`
- --> $DIR/recover-enum.rs:6:9
+error: missing comma
+ --> $DIR/recover-enum.rs:5:13
  |
 LL | Very
- | - expected one of `(`, `,`, `=`, `{`, or `}` here
-LL | Bad
- | ^^^ unexpected token
+ | ^ help: missing comma
 
-error: aborting due to previous error
+error: missing comma
+ --> $DIR/recover-enum.rs:7:19
+ |
+LL | Bad(usize)
+ | ^ help: missing comma
+
+error: missing comma
+ --> $DIR/recover-enum.rs:9:27
+ |
+LL | Stuff { a: usize }
+ | ^ help: missing comma
+
+error: aborting due to 3 previous errors
 

src/test/ui/parser/trait-pub-assoc-const.rs

@@ -1,6 +1,6 @@
 trait Foo {
  pub const Foo: u32;
- //~^ ERROR expected one of `async`, `const`, `extern`, `fn`, `type`, `unsafe`, or `}`, found
+ //~^ ERROR unnecessary visibility qualifier
 }
 
 fn main() {}

src/test/ui/parser/trait-pub-assoc-const.stderr

@@ -1,10 +1,8 @@
-error: expected one of `async`, `const`, `extern`, `fn`, `type`, `unsafe`, or `}`, found `pub`
+error: unnecessary visibility qualifier
  --> $DIR/trait-pub-assoc-const.rs:2:5
  |
-LL | trait Foo {
- | - expected one of 7 possible tokens here
 LL | pub const Foo: u32;
- | ^^^ unexpected token
+ | ^^^ `pub` not permitted here
 
 error: aborting due to previous error
 

src/test/ui/parser/trait-pub-assoc-ty.rs

@@ -1,6 +1,6 @@
 trait Foo {
  pub type Foo;
- //~^ ERROR expected one of `async`, `const`, `extern`, `fn`, `type`, `unsafe`, or `}`, found
+ //~^ ERROR unnecessary visibility qualifier
 }
 
 fn main() {}

src/test/ui/parser/trait-pub-assoc-ty.stderr

@@ -1,10 +1,8 @@
-error: expected one of `async`, `const`, `extern`, `fn`, `type`, `unsafe`, or `}`, found `pub`
+error: unnecessary visibility qualifier
  --> $DIR/trait-pub-assoc-ty.rs:2:5
  |
-LL | trait Foo {
- | - expected one of 7 possible tokens here
 LL | pub type Foo;
- | ^^^ unexpected token
+ | ^^^ `pub` not permitted here
 
 error: aborting due to previous error
 

src/test/ui/parser/trait-pub-method.rs

@@ -1,6 +1,6 @@
 trait Foo {
  pub fn foo();
- //~^ ERROR expected one of `async`, `const`, `extern`, `fn`, `type`, `unsafe`, or `}`, found
+ //~^ ERROR unnecessary visibility qualifier
 }
 
 fn main() {}