compiler/rustc_parse/src/parser/stmt.rs

   1 use super::attr::DEFAULT_INNER_ATTR_FORBIDDEN;
   2 use super::diagnostics::{AttemptLocalParseRecovery, Error};
   3 use super::expr::LhsExpr;
   4 use super::pat::RecoverComma;
   5 use super::path::PathStyle;
   6 use super::TrailingToken;
   7 use super::{AttrWrapper, BlockMode, ForceCollect, Parser, Restrictions, SemiColonMode};
   8 use crate::maybe_whole;
   9
  10 use rustc_ast as ast;
  11 use rustc_ast::ptr::P;
  12 use rustc_ast::token::{self, TokenKind};
  13 use rustc_ast::util::classify;
  14 use rustc_ast::{
  15     AstLike, AttrStyle, AttrVec, Attribute, LocalKind, MacCall, MacCallStmt, MacStmtStyle,
  16 };
  17 use rustc_ast::{Block, BlockCheckMode, Expr, ExprKind, Local, Stmt};
  18 use rustc_ast::{StmtKind, DUMMY_NODE_ID};
  19 use rustc_errors::{Applicability, PResult};
  20 use rustc_span::source_map::{BytePos, Span};
  21 use rustc_span::symbol::{kw, sym};
  22
  23 use std::mem;
  24
  25 impl<'a> Parser<'a> {
  26     /// Parses a statement. This stops just before trailing semicolons on everything but items.
  27     /// e.g., a `StmtKind::Semi` parses to a `StmtKind::Expr`, leaving the trailing `;` unconsumed.
  28     // Public for rustfmt usage.
  29     pub fn parse_stmt(&mut self, force_collect: ForceCollect) -> PResult<'a, Option<Stmt>> {
  30         Ok(self.parse_stmt_without_recovery(false, force_collect).unwrap_or_else(|mut e| {
  31             e.emit();
  32             self.recover_stmt_(SemiColonMode::Break, BlockMode::Ignore);
  33             None
  34         }))
  35     }
  36
  37     /// If `force_capture` is true, forces collection of tokens regardless of whether
  38     /// or not we have attributes
  39     crate fn parse_stmt_without_recovery(
  40         &mut self,
  41         capture_semi: bool,
  42         force_collect: ForceCollect,
  43     ) -> PResult<'a, Option<Stmt>> {
  44         let attrs = self.parse_outer_attributes()?;
  45         let lo = self.token.span;
  46
  47         // Don't use `maybe_whole` so that we have precise control
  48         // over when we bump the parser
  49         if let token::Interpolated(nt) = &self.token.kind {
  50             if let token::NtStmt(stmt) = &**nt {
  51                 let mut stmt = stmt.clone();
  52                 self.bump();
  53                 stmt.visit_attrs(|stmt_attrs| {
  54                     attrs.prepend_to_nt_inner(stmt_attrs);
  55                 });
  56                 return Ok(Some(stmt));
  57             }
  58         }
  59
  60         Ok(Some(if self.token.is_keyword(kw::Let) {
  61             self.parse_local_mk(lo, attrs, capture_semi, force_collect)?
  62         } else if self.is_kw_followed_by_ident(kw::Mut) {
  63             self.recover_stmt_local(lo, attrs, "missing keyword", "let mut")?
  64         } else if self.is_kw_followed_by_ident(kw::Auto) {
  65             self.bump(); // `auto`
  66             let msg = "write `let` instead of `auto` to introduce a new variable";
  67             self.recover_stmt_local(lo, attrs, msg, "let")?
  68         } else if self.is_kw_followed_by_ident(sym::var) {
  69             self.bump(); // `var`
  70             let msg = "write `let` instead of `var` to introduce a new variable";
  71             self.recover_stmt_local(lo, attrs, msg, "let")?
  72         } else if self.check_path() && !self.token.is_qpath_start() && !self.is_path_start_item() {
  73             // We have avoided contextual keywords like `union`, items with `crate` visibility,
  74             // or `auto trait` items. We aim to parse an arbitrary path `a::b` but not something
  75             // that starts like a path (1 token), but it fact not a path.
  76             // Also, we avoid stealing syntax from `parse_item_`.
  77             if force_collect == ForceCollect::Yes {
  78                 self.collect_tokens_no_attrs(|this| this.parse_stmt_path_start(lo, attrs))
  79             } else {
  80                 self.parse_stmt_path_start(lo, attrs)
  81             }?
  82         } else if let Some(item) =
  83             self.parse_item_common(attrs.clone(), false, true, |_| true, force_collect)?
  84         {
  85             // FIXME: Bad copy of attrs
  86             self.mk_stmt(lo.to(item.span), StmtKind::Item(P(item)))
  87         } else if self.eat(&token::Semi) {
  88             // Do not attempt to parse an expression if we're done here.
  89             self.error_outer_attrs(&attrs.take_for_recovery());
  90             self.mk_stmt(lo, StmtKind::Empty)
  91         } else if self.token != token::CloseDelim(token::Brace) {
  92             // Remainder are line-expr stmts.
  93             let e = if force_collect == ForceCollect::Yes {
  94                 self.collect_tokens_no_attrs(|this| {
  95                     this.parse_expr_res(Restrictions::STMT_EXPR, Some(attrs))
  96                 })
  97             } else {
  98                 self.parse_expr_res(Restrictions::STMT_EXPR, Some(attrs))
  99             }?;
 100             self.mk_stmt(lo.to(e.span), StmtKind::Expr(e))
 101         } else {
 102             self.error_outer_attrs(&attrs.take_for_recovery());
 103             return Ok(None);
 104         }))
 105     }
 106
 107     fn parse_stmt_path_start(&mut self, lo: Span, attrs: AttrWrapper) -> PResult<'a, Stmt> {
 108         let stmt = self.collect_tokens_trailing_token(attrs, ForceCollect::No, |this, attrs| {
 109             let path = this.parse_path(PathStyle::Expr)?;
 110
 111             if this.eat(&token::Not) {
 112                 let stmt_mac = this.parse_stmt_mac(lo, attrs.into(), path)?;
 113                 if this.token == token::Semi {
 114                     return Ok((stmt_mac, TrailingToken::Semi));
 115                 } else {
 116                     return Ok((stmt_mac, TrailingToken::None));
 117                 }
 118             }
 119
 120             let expr = if this.eat(&token::OpenDelim(token::Brace)) {
 121                 this.parse_struct_expr(None, path, AttrVec::new(), true)?
 122             } else {
 123                 let hi = this.prev_token.span;
 124                 this.mk_expr(lo.to(hi), ExprKind::Path(None, path), AttrVec::new())
 125             };
 126
 127             let expr = this.with_res(Restrictions::STMT_EXPR, |this| {
 128                 this.parse_dot_or_call_expr_with(expr, lo, attrs)
 129             })?;
 130             // `DUMMY_SP` will get overwritten later in this function
 131             Ok((this.mk_stmt(rustc_span::DUMMY_SP, StmtKind::Expr(expr)), TrailingToken::None))
 132         })?;
 133
 134         if let StmtKind::Expr(expr) = stmt.kind {
 135             // Perform this outside of the `collect_tokens_trailing_token` closure,
 136             // since our outer attributes do not apply to this part of the expression
 137             let expr = self.with_res(Restrictions::STMT_EXPR, |this| {
 138                 this.parse_assoc_expr_with(0, LhsExpr::AlreadyParsed(expr))
 139             })?;
 140             Ok(self.mk_stmt(lo.to(self.prev_token.span), StmtKind::Expr(expr)))
 141         } else {
 142             Ok(stmt)
 143         }
 144     }
 145
 146     /// Parses a statement macro `mac!(args)` provided a `path` representing `mac`.
 147     /// At this point, the `!` token after the path has already been eaten.
 148     fn parse_stmt_mac(&mut self, lo: Span, attrs: AttrVec, path: ast::Path) -> PResult<'a, Stmt> {
 149         let args = self.parse_mac_args()?;
 150         let delim = args.delim();
 151         let hi = self.prev_token.span;
 152
 153         let style =
 154             if delim == token::Brace { MacStmtStyle::Braces } else { MacStmtStyle::NoBraces };
 155
 156         let mac = MacCall { path, args, prior_type_ascription: self.last_type_ascription };
 157
 158         let kind = if delim == token::Brace || self.token == token::Semi || self.token == token::Eof
 159         {
 160             StmtKind::MacCall(P(MacCallStmt { mac, style, attrs, tokens: None }))
 161         } else {
 162             // Since none of the above applied, this is an expression statement macro.
 163             let e = self.mk_expr(lo.to(hi), ExprKind::MacCall(mac), AttrVec::new());
 164             let e = self.maybe_recover_from_bad_qpath(e, true)?;
 165             let e = self.parse_dot_or_call_expr_with(e, lo, attrs.into())?;
 166             let e = self.parse_assoc_expr_with(0, LhsExpr::AlreadyParsed(e))?;
 167             StmtKind::Expr(e)
 168         };
 169         Ok(self.mk_stmt(lo.to(hi), kind))
 170     }
 171
 172     /// Error on outer attributes in this context.
 173     /// Also error if the previous token was a doc comment.
 174     fn error_outer_attrs(&self, attrs: &[Attribute]) {
 175         if let [.., last] = attrs {
 176             if last.is_doc_comment() {
 177                 self.span_err(last.span, Error::UselessDocComment).emit();
 178             } else if attrs.iter().any(|a| a.style == AttrStyle::Outer) {
 179                 self.struct_span_err(last.span, "expected statement after outer attribute").emit();
 180             }
 181         }
 182     }
 183
 184     fn recover_stmt_local(
 185         &mut self,
 186         lo: Span,
 187         attrs: AttrWrapper,
 188         msg: &str,
 189         sugg: &str,
 190     ) -> PResult<'a, Stmt> {
 191         let stmt = self.recover_local_after_let(lo, attrs)?;
 192         self.struct_span_err(lo, "invalid variable declaration")
 193             .span_suggestion(lo, msg, sugg.to_string(), Applicability::MachineApplicable)
 194             .emit();
 195         Ok(stmt)
 196     }
 197
 198     fn parse_local_mk(
 199         &mut self,
 200         lo: Span,
 201         attrs: AttrWrapper,
 202         capture_semi: bool,
 203         force_collect: ForceCollect,
 204     ) -> PResult<'a, Stmt> {
 205         self.collect_tokens_trailing_token(attrs, force_collect, |this, attrs| {
 206             this.expect_keyword(kw::Let)?;
 207             let local = this.parse_local(attrs.into())?;
 208             let trailing = if capture_semi && this.token.kind == token::Semi {
 209                 TrailingToken::Semi
 210             } else {
 211                 TrailingToken::None
 212             };
 213             Ok((this.mk_stmt(lo.to(this.prev_token.span), StmtKind::Local(local)), trailing))
 214         })
 215     }
 216
 217     fn recover_local_after_let(&mut self, lo: Span, attrs: AttrWrapper) -> PResult<'a, Stmt> {
 218         self.collect_tokens_trailing_token(attrs, ForceCollect::No, |this, attrs| {
 219             let local = this.parse_local(attrs.into())?;
 220             // FIXME - maybe capture semicolon in recovery?
 221             Ok((
 222                 this.mk_stmt(lo.to(this.prev_token.span), StmtKind::Local(local)),
 223                 TrailingToken::None,
 224             ))
 225         })
 226     }
 227
 228     /// Parses a local variable declaration.
 229     fn parse_local(&mut self, attrs: AttrVec) -> PResult<'a, P<Local>> {
 230         let lo = self.prev_token.span;
 231         let (pat, colon) = self.parse_pat_before_ty(None, RecoverComma::Yes, "`let` bindings")?;
 232
 233         let (err, ty) = if colon {
 234             // Save the state of the parser before parsing type normally, in case there is a `:`
 235             // instead of an `=` typo.
 236             let parser_snapshot_before_type = self.clone();
 237             let colon_sp = self.prev_token.span;
 238             match self.parse_ty() {
 239                 Ok(ty) => (None, Some(ty)),
 240                 Err(mut err) => {
 241                     if let Ok(snip) = self.span_to_snippet(pat.span) {
 242                         err.span_label(pat.span, format!("while parsing the type for `{}`", snip));
 243                     }
 244                     let err = if self.check(&token::Eq) {
 245                         err.emit();
 246                         None
 247                     } else {
 248                         // Rewind to before attempting to parse the type and continue parsing.
 249                         let parser_snapshot_after_type =
 250                             mem::replace(self, parser_snapshot_before_type);
 251                         Some((parser_snapshot_after_type, colon_sp, err))
 252                     };
 253                     (err, None)
 254                 }
 255             }
 256         } else {
 257             (None, None)
 258         };
 259         let init = match (self.parse_initializer(err.is_some()), err) {
 260             (Ok(init), None) => {
 261                 // init parsed, ty parsed
 262                 init
 263             }
 264             (Ok(init), Some((_, colon_sp, mut err))) => {
 265                 // init parsed, ty error
 266                 // Could parse the type as if it were the initializer, it is likely there was a
 267                 // typo in the code: `:` instead of `=`. Add suggestion and emit the error.
 268                 err.span_suggestion_short(
 269                     colon_sp,
 270                     "use `=` if you meant to assign",
 271                     " =".to_string(),
 272                     Applicability::MachineApplicable,
 273                 );
 274                 err.emit();
 275                 // As this was parsed successfully, continue as if the code has been fixed for the
 276                 // rest of the file. It will still fail due to the emitted error, but we avoid
 277                 // extra noise.
 278                 init
 279             }
 280             (Err(mut init_err), Some((snapshot, _, ty_err))) => {
 281                 // init error, ty error
 282                 init_err.cancel();
 283                 // Couldn't parse the type nor the initializer, only raise the type error and
 284                 // return to the parser state before parsing the type as the initializer.
 285                 // let x: <parse_error>;
 286                 *self = snapshot;
 287                 return Err(ty_err);
 288             }
 289             (Err(err), None) => {
 290                 // init error, ty parsed
 291                 // Couldn't parse the initializer and we're not attempting to recover a failed
 292                 // parse of the type, return the error.
 293                 return Err(err);
 294             }
 295         };
 296         let kind = match init {
 297             None => LocalKind::Decl,
 298             Some(init) => {
 299                 if self.eat_keyword(kw::Else) {
 300                     let els = self.parse_block()?;
 301                     self.check_let_else_init_bool_expr(&init);
 302                     self.check_let_else_init_trailing_brace(&init);
 303                     LocalKind::InitElse(init, els)
 304                 } else {
 305                     LocalKind::Init(init)
 306                 }
 307             }
 308         };
 309         let hi = if self.token == token::Semi { self.token.span } else { self.prev_token.span };
 310         Ok(P(ast::Local { ty, pat, kind, id: DUMMY_NODE_ID, span: lo.to(hi), attrs, tokens: None }))
 311     }
 312
 313     fn check_let_else_init_bool_expr(&self, init: &ast::Expr) {
 314         if let ast::ExprKind::Binary(op, ..) = init.kind {
 315             if op.node.lazy() {
 316                 let suggs = vec![
 317                     (init.span.shrink_to_lo(), "(".to_string()),
 318                     (init.span.shrink_to_hi(), ")".to_string()),
 319                 ];
 320                 self.struct_span_err(
 321                     init.span,
 322                     &format!(
 323                         "a `{}` expression cannot be directly assigned in `let...else`",
 324                         op.node.to_string()
 325                     ),
 326                 )
 327                 .multipart_suggestion(
 328                     "wrap the expression in parenthesis",
 329                     suggs,
 330                     Applicability::MachineApplicable,
 331                 )
 332                 .emit();
 333             }
 334         }
 335     }
 336
 337     fn check_let_else_init_trailing_brace(&self, init: &ast::Expr) {
 338         if let Some(trailing) = classify::expr_trailing_brace(init) {
 339             let err_span = trailing.span.with_lo(trailing.span.hi() - BytePos(1));
 340             let suggs = vec![
 341                 (trailing.span.shrink_to_lo(), "(".to_string()),
 342                 (trailing.span.shrink_to_hi(), ")".to_string()),
 343             ];
 344             self.struct_span_err(
 345                 err_span,
 346                 "right curly brace `}` before `else` in a `let...else` statement not allowed",
 347             )
 348             .multipart_suggestion(
 349                 "try wrapping the expression in parenthesis",
 350                 suggs,
 351                 Applicability::MachineApplicable,
 352             )
 353             .emit();
 354         }
 355     }
 356
 357     /// Parses the RHS of a local variable declaration (e.g., `= 14;`).
 358     fn parse_initializer(&mut self, eq_optional: bool) -> PResult<'a, Option<P<Expr>>> {
 359         let eq_consumed = match self.token.kind {
 360             token::BinOpEq(..) => {
 361                 // Recover `let x <op>= 1` as `let x = 1`
 362                 self.struct_span_err(
 363                     self.token.span,
 364                     "can't reassign to an uninitialized variable",
 365                 )
 366                 .span_suggestion_short(
 367                     self.token.span,
 368                     "initialize the variable",
 369                     "=".to_string(),
 370                     Applicability::MaybeIncorrect,
 371                 )
 372                 .help("if you meant to overwrite, remove the `let` binding")
 373                 .emit();
 374                 self.bump();
 375                 true
 376             }
 377             _ => self.eat(&token::Eq),
 378         };
 379
 380         Ok(if eq_consumed || eq_optional { Some(self.parse_expr()?) } else { None })
 381     }
 382
 383     /// Parses a block. No inner attributes are allowed.
 384     pub(super) fn parse_block(&mut self) -> PResult<'a, P<Block>> {
 385         let (attrs, block) = self.parse_inner_attrs_and_block()?;
 386         if let [.., last] = &*attrs {
 387             self.error_on_forbidden_inner_attr(last.span, DEFAULT_INNER_ATTR_FORBIDDEN);
 388         }
 389         Ok(block)
 390     }
 391
 392     fn error_block_no_opening_brace<T>(&mut self) -> PResult<'a, T> {
 393         let sp = self.token.span;
 394         let tok = super::token_descr(&self.token);
 395         let mut e = self.struct_span_err(sp, &format!("expected `{{`, found {}", tok));
 396         let do_not_suggest_help = self.token.is_keyword(kw::In) || self.token == token::Colon;
 397
 398         // Check to see if the user has written something like
 399         //
 400         //    if (cond)
 401         //      bar;
 402         //
 403         // which is valid in other languages, but not Rust.
 404         match self.parse_stmt_without_recovery(false, ForceCollect::No) {
 405             // If the next token is an open brace (e.g., `if a b {`), the place-
 406             // inside-a-block suggestion would be more likely wrong than right.
 407             Ok(Some(_))
 408                 if self.look_ahead(1, |t| t == &token::OpenDelim(token::Brace))
 409                     || do_not_suggest_help => {}
 410             Ok(Some(stmt)) => {
 411                 let stmt_own_line = self.sess.source_map().is_line_before_span_empty(sp);
 412                 let stmt_span = if stmt_own_line && self.eat(&token::Semi) {
 413                     // Expand the span to include the semicolon.
 414                     stmt.span.with_hi(self.prev_token.span.hi())
 415                 } else {
 416                     stmt.span
 417                 };
 418                 if let Ok(snippet) = self.span_to_snippet(stmt_span) {
 419                     e.span_suggestion(
 420                         stmt_span,
 421                         "try placing this code inside a block",
 422                         format!("{{ {} }}", snippet),
 423                         // Speculative; has been misleading in the past (#46836).
 424                         Applicability::MaybeIncorrect,
 425                     );
 426                 }
 427             }
 428             Err(mut e) => {
 429                 self.recover_stmt_(SemiColonMode::Break, BlockMode::Ignore);
 430                 e.cancel();
 431             }
 432             _ => {}
 433         }
 434         e.span_label(sp, "expected `{`");
 435         Err(e)
 436     }
 437
 438     /// Parses a block. Inner attributes are allowed.
 439     pub(super) fn parse_inner_attrs_and_block(
 440         &mut self,
 441     ) -> PResult<'a, (Vec<Attribute>, P<Block>)> {
 442         self.parse_block_common(self.token.span, BlockCheckMode::Default)
 443     }
 444
 445     /// Parses a block. Inner attributes are allowed.
 446     pub(super) fn parse_block_common(
 447         &mut self,
 448         lo: Span,
 449         blk_mode: BlockCheckMode,
 450     ) -> PResult<'a, (Vec<Attribute>, P<Block>)> {
 451         maybe_whole!(self, NtBlock, |x| (Vec::new(), x));
 452
 453         if !self.eat(&token::OpenDelim(token::Brace)) {
 454             return self.error_block_no_opening_brace();
 455         }
 456
 457         let attrs = self.parse_inner_attributes()?;
 458         let tail = if let Some(tail) = self.maybe_suggest_struct_literal(lo, blk_mode) {
 459             tail?
 460         } else {
 461             self.parse_block_tail(lo, blk_mode, AttemptLocalParseRecovery::Yes)?
 462         };
 463         Ok((attrs, tail))
 464     }
 465
 466     /// Parses the rest of a block expression or function body.
 467     /// Precondition: already parsed the '{'.
 468     crate fn parse_block_tail(
 469         &mut self,
 470         lo: Span,
 471         s: BlockCheckMode,
 472         recover: AttemptLocalParseRecovery,
 473     ) -> PResult<'a, P<Block>> {
 474         let mut stmts = vec![];
 475         while !self.eat(&token::CloseDelim(token::Brace)) {
 476             if self.token == token::Eof {
 477                 break;
 478             }
 479             let stmt = match self.parse_full_stmt(recover) {
 480                 Err(mut err) if recover.yes() => {
 481                     self.maybe_annotate_with_ascription(&mut err, false);
 482                     err.emit();
 483                     self.recover_stmt_(SemiColonMode::Ignore, BlockMode::Ignore);
 484                     Some(self.mk_stmt_err(self.token.span))
 485                 }
 486                 Ok(stmt) => stmt,
 487                 Err(err) => return Err(err),
 488             };
 489             if let Some(stmt) = stmt {
 490                 stmts.push(stmt);
 491             } else {
 492                 // Found only `;` or `}`.
 493                 continue;
 494             };
 495         }
 496         Ok(self.mk_block(stmts, s, lo.to(self.prev_token.span)))
 497     }
 498
 499     /// Parses a statement, including the trailing semicolon.
 500     pub fn parse_full_stmt(
 501         &mut self,
 502         recover: AttemptLocalParseRecovery,
 503     ) -> PResult<'a, Option<Stmt>> {
 504         // Skip looking for a trailing semicolon when we have an interpolated statement.
 505         maybe_whole!(self, NtStmt, |x| Some(x));
 506
 507         let mut stmt = match self.parse_stmt_without_recovery(true, ForceCollect::No)? {
 508             Some(stmt) => stmt,
 509             None => return Ok(None),
 510         };
 511
 512         let mut eat_semi = true;
 513         match stmt.kind {
 514             // Expression without semicolon.
 515             StmtKind::Expr(ref mut expr)
 516                 if self.token != token::Eof && classify::expr_requires_semi_to_be_stmt(expr) =>
 517             {
 518                 // Just check for errors and recover; do not eat semicolon yet.
 519                 if let Err(mut e) =
 520                     self.expect_one_of(&[], &[token::Semi, token::CloseDelim(token::Brace)])
 521                 {
 522                     if let TokenKind::DocComment(..) = self.token.kind {
 523                         if let Ok(snippet) = self.span_to_snippet(self.token.span) {
 524                             let sp = self.token.span;
 525                             let marker = &snippet[..3];
 526                             let (comment_marker, doc_comment_marker) = marker.split_at(2);
 527
 528                             e.span_suggestion(
 529                                 sp.with_hi(sp.lo() + BytePos(marker.len() as u32)),
 530                                 &format!(
 531                                     "add a space before `{}` to use a regular comment",
 532                                     doc_comment_marker,
 533                                 ),
 534                                 format!("{} {}", comment_marker, doc_comment_marker),
 535                                 Applicability::MaybeIncorrect,
 536                             );
 537                         }
 538                     }
 539                     if let Err(mut e) =
 540                         self.check_mistyped_turbofish_with_multiple_type_params(e, expr)
 541                     {
 542                         if recover.no() {
 543                             return Err(e);
 544                         }
 545                         e.emit();
 546                         self.recover_stmt();
 547                     }
 548                     // Don't complain about type errors in body tail after parse error (#57383).
 549                     let sp = expr.span.to(self.prev_token.span);
 550                     *expr = self.mk_expr_err(sp);
 551                 }
 552             }
 553             StmtKind::Expr(_) | StmtKind::MacCall(_) => {}
 554             StmtKind::Local(ref mut local) if let Err(e) = self.expect_semi() => {
 555                 // We might be at the `,` in `let x = foo<bar, baz>;`. Try to recover.
 556                 match &mut local.kind {
 557                     LocalKind::Init(expr) | LocalKind::InitElse(expr, _) => {
 558                             self.check_mistyped_turbofish_with_multiple_type_params(e, expr)?;
 559                             // We found `foo<bar, baz>`, have we fully recovered?
 560                             self.expect_semi()?;
 561                         }
 562                         LocalKind::Decl => return Err(e),
 563                 }
 564                 eat_semi = false;
 565             }
 566             StmtKind::Empty | StmtKind::Item(_) | StmtKind::Local(_) | StmtKind::Semi(_) => eat_semi = false,
 567         }
 568
 569         if eat_semi && self.eat(&token::Semi) {
 570             stmt = stmt.add_trailing_semicolon();
 571         }
 572         stmt.span = stmt.span.to(self.prev_token.span);
 573         Ok(Some(stmt))
 574     }
 575
 576     pub(super) fn mk_block(&self, stmts: Vec<Stmt>, rules: BlockCheckMode, span: Span) -> P<Block> {
 577         P(Block {
 578             stmts,
 579             id: DUMMY_NODE_ID,
 580             rules,
 581             span,
 582             tokens: None,
 583             could_be_bare_literal: false,
 584         })
 585     }
 586
 587     pub(super) fn mk_stmt(&self, span: Span, kind: StmtKind) -> Stmt {
 588         Stmt { id: DUMMY_NODE_ID, kind, span }
 589     }
 590
 591     pub(super) fn mk_stmt_err(&self, span: Span) -> Stmt {
 592         self.mk_stmt(span, StmtKind::Expr(self.mk_expr_err(span)))
 593     }
 594
 595     pub(super) fn mk_block_err(&self, span: Span) -> P<Block> {
 596         self.mk_block(vec![self.mk_stmt_err(span)], BlockCheckMode::Default, span)
 597     }
 598 }