Auto merge of #2618 - RalfJung:rustup, r=RalfJung

Rustup

6 files changed, 126 insertions, 30 deletions

diff --git a/compiler/rustc_parse/src/parser/attr.rs b/compiler/rustc_parse/src/parser/attr.rs
index 58be348883c..9e45656946b 100644
--- a/compiler/rustc_parse/src/parser/attr.rs
+++ b/compiler/rustc_parse/src/parser/attr.rs
@@ -55,7 +55,7 @@ impl<'a> Parser<'a> {
                     let span = self.token.span;
                     let mut err = self.sess.span_diagnostic.struct_span_err_with_code(
                         span,
-                        fluent::parser::inner_doc_comment_not_permitted,
+                        fluent::parser_inner_doc_comment_not_permitted,
                         error_code!(E0753),
                     );
                     if let Some(replacement_span) = self.annotate_following_item_if_applicable(
@@ -66,10 +66,10 @@ impl<'a> Parser<'a> {
                             token::CommentKind::Block => OuterAttributeType::DocBlockComment,
                         },
                     ) {
-                        err.note(fluent::parser::note);
+                        err.note(fluent::note);
                         err.span_suggestion_verbose(
                             replacement_span,
-                            fluent::parser::suggestion,
+                            fluent::suggestion,
                             "",
                             rustc_errors::Applicability::MachineApplicable,
                         );
@@ -173,10 +173,10 @@ impl<'a> Parser<'a> {
             Ok(Some(item)) => {
                 // FIXME(#100717)
                 err.set_arg("item", item.kind.descr());
-                err.span_label(item.span, fluent::parser::label_does_not_annotate_this);
+                err.span_label(item.span, fluent::label_does_not_annotate_this);
                 err.span_suggestion_verbose(
                     replacement_span,
-                    fluent::parser::sugg_change_inner_to_outer,
+                    fluent::sugg_change_inner_to_outer,
                     match attr_type {
                         OuterAttributeType::Attribute => "",
                         OuterAttributeType::DocBlockComment => "*",
@@ -200,27 +200,27 @@ impl<'a> Parser<'a> {
                 Some(InnerAttrForbiddenReason::AfterOuterDocComment { prev_doc_comment_span }) => {
                     let mut diag = self.struct_span_err(
                         attr_sp,
-                        fluent::parser::inner_attr_not_permitted_after_outer_doc_comment,
+                        fluent::parser_inner_attr_not_permitted_after_outer_doc_comment,
                     );
-                    diag.span_label(attr_sp, fluent::parser::label_attr)
-                        .span_label(prev_doc_comment_span, fluent::parser::label_prev_doc_comment);
+                    diag.span_label(attr_sp, fluent::label_attr)
+                        .span_label(prev_doc_comment_span, fluent::label_prev_doc_comment);
                     diag
                 }
                 Some(InnerAttrForbiddenReason::AfterOuterAttribute { prev_outer_attr_sp }) => {
                     let mut diag = self.struct_span_err(
                         attr_sp,
-                        fluent::parser::inner_attr_not_permitted_after_outer_attr,
+                        fluent::parser_inner_attr_not_permitted_after_outer_attr,
                     );
-                    diag.span_label(attr_sp, fluent::parser::label_attr)
-                        .span_label(prev_outer_attr_sp, fluent::parser::label_prev_attr);
+                    diag.span_label(attr_sp, fluent::label_attr)
+                        .span_label(prev_outer_attr_sp, fluent::label_prev_attr);
                     diag
                 }
                 Some(InnerAttrForbiddenReason::InCodeBlock) | None => {
-                    self.struct_span_err(attr_sp, fluent::parser::inner_attr_not_permitted)
+                    self.struct_span_err(attr_sp, fluent::parser_inner_attr_not_permitted)
                 }
             };
 
-            diag.note(fluent::parser::inner_attr_explanation);
+            diag.note(fluent::parser_inner_attr_explanation);
             if self
                 .annotate_following_item_if_applicable(
                     &mut diag,
@@ -229,7 +229,7 @@ impl<'a> Parser<'a> {
                 )
                 .is_some()
             {
-                diag.note(fluent::parser::outer_attr_explanation);
+                diag.note(fluent::parser_outer_attr_explanation);
             };
             diag.emit();
         }
diff --git a/compiler/rustc_parse/src/parser/attr_wrapper.rs b/compiler/rustc_parse/src/parser/attr_wrapper.rs
index 81c051b8f35..1b16ecb5ec2 100644
--- a/compiler/rustc_parse/src/parser/attr_wrapper.rs
+++ b/compiler/rustc_parse/src/parser/attr_wrapper.rs
@@ -273,16 +273,23 @@ impl<'a> Parser<'a> {
         let cursor_snapshot_next_calls = cursor_snapshot.num_next_calls;
         let mut end_pos = self.token_cursor.num_next_calls;
 
+        let mut captured_trailing = false;
+
         // Capture a trailing token if requested by the callback 'f'
         match trailing {
             TrailingToken::None => {}
+            TrailingToken::Gt => {
+                assert_eq!(self.token.kind, token::Gt);
+            }
             TrailingToken::Semi => {
                 assert_eq!(self.token.kind, token::Semi);
                 end_pos += 1;
+                captured_trailing = true;
             }
             TrailingToken::MaybeComma => {
                 if self.token.kind == token::Comma {
                     end_pos += 1;
+                    captured_trailing = true;
                 }
             }
         }
@@ -292,11 +299,7 @@ impl<'a> Parser<'a> {
         // was not actually bumped past it. When the `LazyAttrTokenStream` gets converted
         // into an `AttrTokenStream`, we will create the proper token.
         if self.token_cursor.break_last_token {
-            assert_eq!(
-                trailing,
-                TrailingToken::None,
-                "Cannot set `break_last_token` and have trailing token"
-            );
+            assert!(!captured_trailing, "Cannot set break_last_token and have trailing token");
             end_pos += 1;
         }
 
diff --git a/compiler/rustc_parse/src/parser/diagnostics.rs b/compiler/rustc_parse/src/parser/diagnostics.rs
index 40d85c833a7..887a4a6de33 100644
--- a/compiler/rustc_parse/src/parser/diagnostics.rs
+++ b/compiler/rustc_parse/src/parser/diagnostics.rs
@@ -926,7 +926,7 @@ impl<'a> Parser<'a> {
                     if self.eat(&token::Gt) {
                         e.span_suggestion_verbose(
                             binop.span.shrink_to_lo(),
-                            fluent::parser::sugg_turbofish_syntax,
+                            fluent::parser_sugg_turbofish_syntax,
                             "::",
                             Applicability::MaybeIncorrect,
                         )
@@ -1374,9 +1374,17 @@ impl<'a> Parser<'a> {
         kind: IncDecRecovery,
         (pre_span, post_span): (Span, Span),
     ) -> MultiSugg {
+        let mut patches = Vec::new();
+
+        if !pre_span.is_empty() {
+            patches.push((pre_span, String::new()));
+        }
+
+        patches.push((post_span, format!(" {}= 1", kind.op.chr())));
+
         MultiSugg {
             msg: format!("use `{}= 1` instead", kind.op.chr()),
-            patches: vec![(pre_span, String::new()), (post_span, format!(" {}= 1", kind.op.chr()))],
+            patches,
             applicability: Applicability::MachineApplicable,
         }
     }
diff --git a/compiler/rustc_parse/src/parser/expr.rs b/compiler/rustc_parse/src/parser/expr.rs
index afa116ce1bc..ca216b1cd10 100644
--- a/compiler/rustc_parse/src/parser/expr.rs
+++ b/compiler/rustc_parse/src/parser/expr.rs
@@ -42,8 +42,10 @@ use rustc_ast::{AnonConst, BinOp, BinOpKind, FnDecl, FnRetTy, MacCall, Param, Ty
 use rustc_ast::{Arm, Async, BlockCheckMode, Expr, ExprKind, Label, Movability, RangeLimits};
 use rustc_ast::{ClosureBinder, StmtKind};
 use rustc_ast_pretty::pprust;
-use rustc_errors::IntoDiagnostic;
-use rustc_errors::{Applicability, Diagnostic, PResult};
+use rustc_errors::{
+    Applicability, Diagnostic, DiagnosticBuilder, ErrorGuaranteed, IntoDiagnostic, PResult,
+    StashKey,
+};
 use rustc_session::errors::ExprParenthesesNeeded;
 use rustc_session::lint::builtin::BREAK_WITH_LABEL_AND_LOOP;
 use rustc_session::lint::BuiltinLintDiagnostics;
@@ -1513,11 +1515,11 @@ impl<'a> Parser<'a> {
     /// Parse `'label: $expr`. The label is already parsed.
     fn parse_labeled_expr(
         &mut self,
-        label: Label,
+        label_: Label,
         mut consume_colon: bool,
     ) -> PResult<'a, P<Expr>> {
-        let lo = label.ident.span;
-        let label = Some(label);
+        let lo = label_.ident.span;
+        let label = Some(label_);
         let ate_colon = self.eat(&token::Colon);
         let expr = if self.eat_keyword(kw::While) {
             self.parse_while_expr(label, lo)
@@ -1530,6 +1532,19 @@ impl<'a> Parser<'a> {
         {
             self.parse_block_expr(label, lo, BlockCheckMode::Default)
         } else if !ate_colon
+            && (matches!(self.token.kind, token::CloseDelim(_) | token::Comma)
+                || self.token.is_op())
+        {
+            let lit = self.recover_unclosed_char(label_.ident, |self_| {
+                self_.sess.create_err(UnexpectedTokenAfterLabel {
+                    span: self_.token.span,
+                    remove_label: None,
+                    enclose_in_block: None,
+                })
+            });
+            consume_colon = false;
+            Ok(self.mk_expr(lo, ExprKind::Lit(lit)))
+        } else if !ate_colon
             && (self.check_noexpect(&TokenKind::Comma) || self.check_noexpect(&TokenKind::Gt))
         {
             // We're probably inside of a `Path<'a>` that needs a turbofish
@@ -1603,6 +1618,39 @@ impl<'a> Parser<'a> {
         Ok(expr)
     }
 
+    /// Emit an error when a char is parsed as a lifetime because of a missing quote
+    pub(super) fn recover_unclosed_char(
+        &mut self,
+        lifetime: Ident,
+        err: impl FnOnce(&mut Self) -> DiagnosticBuilder<'a, ErrorGuaranteed>,
+    ) -> ast::Lit {
+        if let Some(mut diag) =
+            self.sess.span_diagnostic.steal_diagnostic(lifetime.span, StashKey::LifetimeIsChar)
+        {
+            diag.span_suggestion_verbose(
+                lifetime.span.shrink_to_hi(),
+                "add `'` to close the char literal",
+                "'",
+                Applicability::MaybeIncorrect,
+            )
+            .emit();
+        } else {
+            err(self)
+                .span_suggestion_verbose(
+                    lifetime.span.shrink_to_hi(),
+                    "add `'` to close the char literal",
+                    "'",
+                    Applicability::MaybeIncorrect,
+                )
+                .emit();
+        }
+        ast::Lit {
+            token_lit: token::Lit::new(token::LitKind::Char, lifetime.name, None),
+            kind: ast::LitKind::Char(lifetime.name.as_str().chars().next().unwrap_or('_')),
+            span: lifetime.span,
+        }
+    }
+
     /// Recover on the syntax `do catch { ... }` suggesting `try { ... }` instead.
     fn recover_do_catch(&mut self) -> PResult<'a, P<Expr>> {
         let lo = self.token.span;
@@ -1728,7 +1776,7 @@ impl<'a> Parser<'a> {
     }
 
     pub(super) fn parse_lit(&mut self) -> PResult<'a, Lit> {
-        self.parse_opt_lit().ok_or_else(|| {
+        self.parse_opt_lit().ok_or(()).or_else(|()| {
             if let token::Interpolated(inner) = &self.token.kind {
                 let expr = match inner.as_ref() {
                     token::NtExpr(expr) => Some(expr),
@@ -1740,12 +1788,22 @@ impl<'a> Parser<'a> {
                         let mut err = InvalidInterpolatedExpression { span: self.token.span }
                             .into_diagnostic(&self.sess.span_diagnostic);
                         err.downgrade_to_delayed_bug();
-                        return err;
+                        return Err(err);
                     }
                 }
             }
-            let msg = format!("unexpected token: {}", super::token_descr(&self.token));
-            self.struct_span_err(self.token.span, &msg)
+            let token = self.token.clone();
+            let err = |self_: &mut Self| {
+                let msg = format!("unexpected token: {}", super::token_descr(&token));
+                self_.struct_span_err(token.span, &msg)
+            };
+            // On an error path, eagerly consider a lifetime to be an unclosed character lit
+            if self.token.is_lifetime() {
+                let lt = self.expect_lifetime();
+                Ok(self.recover_unclosed_char(lt.ident, err))
+            } else {
+                Err(err(self))
+            }
         })
     }
 
@@ -2051,6 +2109,10 @@ impl<'a> Parser<'a> {
 
         if self.token.kind == TokenKind::Semi
             && matches!(self.token_cursor.frame.delim_sp, Some((Delimiter::Parenthesis, _)))
+            // HACK: This is needed so we can detect whether we're inside a macro,
+            // where regular assumptions about what tokens can follow other tokens
+            // don't necessarily apply.
+            && self.subparser_name.is_none()
         {
             // It is likely that the closure body is a block but where the
             // braces have been removed. We will recover and eat the next
@@ -3080,6 +3142,8 @@ impl<'a> Parser<'a> {
                 && this.token.kind == token::Semi
             {
                 TrailingToken::Semi
+            } else if this.token.kind == token::Gt {
+                TrailingToken::Gt
             } else {
                 // FIXME - pass this through from the place where we know
                 // we need a comma, rather than assuming that `#[attr] expr,`
diff --git a/compiler/rustc_parse/src/parser/mod.rs b/compiler/rustc_parse/src/parser/mod.rs
index b934e087608..89c24920f85 100644
--- a/compiler/rustc_parse/src/parser/mod.rs
+++ b/compiler/rustc_parse/src/parser/mod.rs
@@ -79,6 +79,7 @@ pub enum ForceCollect {
 pub enum TrailingToken {
     None,
     Semi,
+    Gt,
     /// If the trailing token is a comma, then capture it
     /// Otherwise, ignore the trailing token
     MaybeComma,
diff --git a/compiler/rustc_parse/src/parser/pat.rs b/compiler/rustc_parse/src/parser/pat.rs
index 56efec422d6..52c11b4e35f 100644
--- a/compiler/rustc_parse/src/parser/pat.rs
+++ b/compiler/rustc_parse/src/parser/pat.rs
@@ -402,6 +402,25 @@ impl<'a> Parser<'a> {
             } else {
                 PatKind::Path(qself, path)
             }
+        } else if matches!(self.token.kind, token::Lifetime(_))
+            // In pattern position, we're totally fine with using "next token isn't colon"
+            // as a heuristic. We could probably just always try to recover if it's a lifetime,
+            // because we never have `'a: label {}` in a pattern position anyways, but it does
+            // keep us from suggesting something like `let 'a: Ty = ..` => `let 'a': Ty = ..`
+            && !self.look_ahead(1, |token| matches!(token.kind, token::Colon))
+        {
+            // Recover a `'a` as a `'a'` literal
+            let lt = self.expect_lifetime();
+            let lit = self.recover_unclosed_char(lt.ident, |self_| {
+                let expected = expected.unwrap_or("pattern");
+                let msg =
+                    format!("expected {}, found {}", expected, super::token_descr(&self_.token));
+
+                let mut err = self_.struct_span_err(self_.token.span, &msg);
+                err.span_label(self_.token.span, format!("expected {}", expected));
+                err
+            });
+            PatKind::Lit(self.mk_expr(lo, ExprKind::Lit(lit)))
         } else {
             // Try to parse everything else as literal with optional minus
             match self.parse_literal_maybe_minus() {
@@ -799,6 +818,7 @@ impl<'a> Parser<'a> {
                 || t.kind == token::Dot // e.g. `.5` for recovery;
                 || t.can_begin_literal_maybe_minus() // e.g. `42`.
                 || t.is_whole_expr()
+                || t.is_lifetime() // recover `'a` instead of `'a'`
             })
     }