compiler/rustc_parse/src/parser/stmt.rs

   1 use super::attr::DEFAULT_INNER_ATTR_FORBIDDEN;
   2 use super::diagnostics::{
   3     AttemptLocalParseRecovery, Error, InvalidVariableDeclaration, InvalidVariableDeclarationSub,
   4 };
   5 use super::expr::LhsExpr;
   6 use super::pat::RecoverComma;
   7 use super::path::PathStyle;
   8 use super::TrailingToken;
   9 use super::{
  10     AttrWrapper, BlockMode, FnParseMode, ForceCollect, Parser, Restrictions, SemiColonMode,
  11 };
  12 use crate::maybe_whole;
  13
  14 use rustc_ast as ast;
  15 use rustc_ast::ptr::P;
  16 use rustc_ast::token::{self, Delimiter, TokenKind};
  17 use rustc_ast::util::classify;
  18 use rustc_ast::{AttrStyle, AttrVec, Attribute, LocalKind, MacCall, MacCallStmt, MacStmtStyle};
  19 use rustc_ast::{Block, BlockCheckMode, Expr, ExprKind, HasAttrs, Local, Stmt};
  20 use rustc_ast::{StmtKind, DUMMY_NODE_ID};
  21 use rustc_errors::{Applicability, DiagnosticBuilder, ErrorGuaranteed, PResult};
  22 use rustc_span::source_map::{BytePos, Span};
  23 use rustc_span::symbol::{kw, sym};
  24
  25 use std::mem;
  26
  27 impl<'a> Parser<'a> {
  28     /// Parses a statement. This stops just before trailing semicolons on everything but items.
  29     /// e.g., a `StmtKind::Semi` parses to a `StmtKind::Expr`, leaving the trailing `;` unconsumed.
  30     // Public for rustfmt usage.
  31     pub fn parse_stmt(&mut self, force_collect: ForceCollect) -> PResult<'a, Option<Stmt>> {
  32         Ok(self.parse_stmt_without_recovery(false, force_collect).unwrap_or_else(|mut e| {
  33             e.emit();
  34             self.recover_stmt_(SemiColonMode::Break, BlockMode::Ignore);
  35             None
  36         }))
  37     }
  38
  39     /// If `force_collect` is [`ForceCollect::Yes`], forces collection of tokens regardless of whether
  40     /// or not we have attributes
  41     pub(crate) fn parse_stmt_without_recovery(
  42         &mut self,
  43         capture_semi: bool,
  44         force_collect: ForceCollect,
  45     ) -> PResult<'a, Option<Stmt>> {
  46         let attrs = self.parse_outer_attributes()?;
  47         let lo = self.token.span;
  48
  49         // Don't use `maybe_whole` so that we have precise control
  50         // over when we bump the parser
  51         if let token::Interpolated(nt) = &self.token.kind && let token::NtStmt(stmt) = &**nt {
  52             let mut stmt = stmt.clone();
  53             self.bump();
  54             stmt.visit_attrs(|stmt_attrs| {
  55                 attrs.prepend_to_nt_inner(stmt_attrs);
  56             });
  57             return Ok(Some(stmt.into_inner()));
  58         }
  59
  60         if self.token.is_keyword(kw::Mut) && self.is_keyword_ahead(1, &[kw::Let]) {
  61             self.bump();
  62             let mut_let_span = lo.to(self.token.span);
  63             self.sess.emit_err(InvalidVariableDeclaration {
  64                 span: mut_let_span,
  65                 sub: InvalidVariableDeclarationSub::SwitchMutLetOrder(mut_let_span),
  66             });
  67         }
  68
  69         Ok(Some(if self.token.is_keyword(kw::Let) {
  70             self.parse_local_mk(lo, attrs, capture_semi, force_collect)?
  71         } else if self.is_kw_followed_by_ident(kw::Mut) {
  72             self.recover_stmt_local(lo, attrs, InvalidVariableDeclarationSub::MissingLet)?
  73         } else if self.is_kw_followed_by_ident(kw::Auto) {
  74             self.bump(); // `auto`
  75             self.recover_stmt_local(lo, attrs, InvalidVariableDeclarationSub::UseLetNotAuto)?
  76         } else if self.is_kw_followed_by_ident(sym::var) {
  77             self.bump(); // `var`
  78             self.recover_stmt_local(lo, attrs, InvalidVariableDeclarationSub::UseLetNotVar)?
  79         } else if self.check_path() && !self.token.is_qpath_start() && !self.is_path_start_item() {
  80             // We have avoided contextual keywords like `union`, items with `crate` visibility,
  81             // or `auto trait` items. We aim to parse an arbitrary path `a::b` but not something
  82             // that starts like a path (1 token), but it fact not a path.
  83             // Also, we avoid stealing syntax from `parse_item_`.
  84             if force_collect == ForceCollect::Yes {
  85                 self.collect_tokens_no_attrs(|this| this.parse_stmt_path_start(lo, attrs))
  86             } else {
  87                 self.parse_stmt_path_start(lo, attrs)
  88             }?
  89         } else if let Some(item) = self.parse_item_common(
  90             attrs.clone(),
  91             false,
  92             true,
  93             FnParseMode { req_name: |_| true, req_body: true },
  94             force_collect,
  95         )? {
  96             // FIXME: Bad copy of attrs
  97             self.mk_stmt(lo.to(item.span), StmtKind::Item(P(item)))
  98         } else if self.eat(&token::Semi) {
  99             // Do not attempt to parse an expression if we're done here.
 100             self.error_outer_attrs(&attrs.take_for_recovery());
 101             self.mk_stmt(lo, StmtKind::Empty)
 102         } else if self.token != token::CloseDelim(Delimiter::Brace) {
 103             // Remainder are line-expr stmts.
 104             let e = if force_collect == ForceCollect::Yes {
 105                 self.collect_tokens_no_attrs(|this| {
 106                     this.parse_expr_res(Restrictions::STMT_EXPR, Some(attrs))
 107                 })
 108             } else {
 109                 self.parse_expr_res(Restrictions::STMT_EXPR, Some(attrs))
 110             }?;
 111             if matches!(e.kind, ExprKind::Assign(..)) && self.eat_keyword(kw::Else) {
 112                 let bl = self.parse_block()?;
 113                 // Destructuring assignment ... else.
 114                 // This is not allowed, but point it out in a nice way.
 115                 let mut err = self.struct_span_err(
 116                     e.span.to(bl.span),
 117                     "<assignment> ... else { ... } is not allowed",
 118                 );
 119                 err.emit();
 120             }
 121             self.mk_stmt(lo.to(e.span), StmtKind::Expr(e))
 122         } else {
 123             self.error_outer_attrs(&attrs.take_for_recovery());
 124             return Ok(None);
 125         }))
 126     }
 127
 128     fn parse_stmt_path_start(&mut self, lo: Span, attrs: AttrWrapper) -> PResult<'a, Stmt> {
 129         let stmt = self.collect_tokens_trailing_token(attrs, ForceCollect::No, |this, attrs| {
 130             let path = this.parse_path(PathStyle::Expr)?;
 131
 132             if this.eat(&token::Not) {
 133                 let stmt_mac = this.parse_stmt_mac(lo, attrs, path)?;
 134                 if this.token == token::Semi {
 135                     return Ok((stmt_mac, TrailingToken::Semi));
 136                 } else {
 137                     return Ok((stmt_mac, TrailingToken::None));
 138                 }
 139             }
 140
 141             let expr = if this.eat(&token::OpenDelim(Delimiter::Brace)) {
 142                 this.parse_struct_expr(None, path, true)?
 143             } else {
 144                 let hi = this.prev_token.span;
 145                 this.mk_expr(lo.to(hi), ExprKind::Path(None, path))
 146             };
 147
 148             let expr = this.with_res(Restrictions::STMT_EXPR, |this| {
 149                 this.parse_dot_or_call_expr_with(expr, lo, attrs)
 150             })?;
 151             // `DUMMY_SP` will get overwritten later in this function
 152             Ok((this.mk_stmt(rustc_span::DUMMY_SP, StmtKind::Expr(expr)), TrailingToken::None))
 153         })?;
 154
 155         if let StmtKind::Expr(expr) = stmt.kind {
 156             // Perform this outside of the `collect_tokens_trailing_token` closure,
 157             // since our outer attributes do not apply to this part of the expression
 158             let expr = self.with_res(Restrictions::STMT_EXPR, |this| {
 159                 this.parse_assoc_expr_with(0, LhsExpr::AlreadyParsed(expr))
 160             })?;
 161             Ok(self.mk_stmt(lo.to(self.prev_token.span), StmtKind::Expr(expr)))
 162         } else {
 163             Ok(stmt)
 164         }
 165     }
 166
 167     /// Parses a statement macro `mac!(args)` provided a `path` representing `mac`.
 168     /// At this point, the `!` token after the path has already been eaten.
 169     fn parse_stmt_mac(&mut self, lo: Span, attrs: AttrVec, path: ast::Path) -> PResult<'a, Stmt> {
 170         let args = self.parse_mac_args()?;
 171         let delim = args.delim();
 172         let hi = self.prev_token.span;
 173
 174         let style = match delim {
 175             Some(Delimiter::Brace) => MacStmtStyle::Braces,
 176             Some(_) => MacStmtStyle::NoBraces,
 177             None => unreachable!(),
 178         };
 179
 180         let mac = P(MacCall { path, args, prior_type_ascription: self.last_type_ascription });
 181
 182         let kind = if (style == MacStmtStyle::Braces
 183             && self.token != token::Dot
 184             && self.token != token::Question)
 185             || self.token == token::Semi
 186             || self.token == token::Eof
 187         {
 188             StmtKind::MacCall(P(MacCallStmt { mac, style, attrs, tokens: None }))
 189         } else {
 190             // Since none of the above applied, this is an expression statement macro.
 191             let e = self.mk_expr(lo.to(hi), ExprKind::MacCall(mac));
 192             let e = self.maybe_recover_from_bad_qpath(e)?;
 193             let e = self.parse_dot_or_call_expr_with(e, lo, attrs)?;
 194             let e = self.parse_assoc_expr_with(0, LhsExpr::AlreadyParsed(e))?;
 195             StmtKind::Expr(e)
 196         };
 197         Ok(self.mk_stmt(lo.to(hi), kind))
 198     }
 199
 200     /// Error on outer attributes in this context.
 201     /// Also error if the previous token was a doc comment.
 202     fn error_outer_attrs(&self, attrs: &[Attribute]) {
 203         if let [.., last] = attrs {
 204             if last.is_doc_comment() {
 205                 self.span_err(last.span, Error::UselessDocComment).emit();
 206             } else if attrs.iter().any(|a| a.style == AttrStyle::Outer) {
 207                 self.struct_span_err(last.span, "expected statement after outer attribute").emit();
 208             }
 209         }
 210     }
 211
 212     fn recover_stmt_local(
 213         &mut self,
 214         lo: Span,
 215         attrs: AttrWrapper,
 216         subdiagnostic: fn(Span) -> InvalidVariableDeclarationSub,
 217     ) -> PResult<'a, Stmt> {
 218         let stmt = self.recover_local_after_let(lo, attrs)?;
 219         self.sess.emit_err(InvalidVariableDeclaration { span: lo, sub: subdiagnostic(lo) });
 220         Ok(stmt)
 221     }
 222
 223     fn parse_local_mk(
 224         &mut self,
 225         lo: Span,
 226         attrs: AttrWrapper,
 227         capture_semi: bool,
 228         force_collect: ForceCollect,
 229     ) -> PResult<'a, Stmt> {
 230         self.collect_tokens_trailing_token(attrs, force_collect, |this, attrs| {
 231             this.expect_keyword(kw::Let)?;
 232             let local = this.parse_local(attrs)?;
 233             let trailing = if capture_semi && this.token.kind == token::Semi {
 234                 TrailingToken::Semi
 235             } else {
 236                 TrailingToken::None
 237             };
 238             Ok((this.mk_stmt(lo.to(this.prev_token.span), StmtKind::Local(local)), trailing))
 239         })
 240     }
 241
 242     fn recover_local_after_let(&mut self, lo: Span, attrs: AttrWrapper) -> PResult<'a, Stmt> {
 243         self.collect_tokens_trailing_token(attrs, ForceCollect::No, |this, attrs| {
 244             let local = this.parse_local(attrs)?;
 245             // FIXME - maybe capture semicolon in recovery?
 246             Ok((
 247                 this.mk_stmt(lo.to(this.prev_token.span), StmtKind::Local(local)),
 248                 TrailingToken::None,
 249             ))
 250         })
 251     }
 252
 253     /// Parses a local variable declaration.
 254     fn parse_local(&mut self, attrs: AttrVec) -> PResult<'a, P<Local>> {
 255         let lo = self.prev_token.span;
 256
 257         if self.token.is_keyword(kw::Const) && self.look_ahead(1, |t| t.is_ident()) {
 258             self.struct_span_err(
 259                 lo.to(self.token.span),
 260                 "`const` and `let` are mutually exclusive",
 261             )
 262             .span_suggestion(
 263                 lo.to(self.token.span),
 264                 "remove `let`",
 265                 "const",
 266                 Applicability::MaybeIncorrect,
 267             )
 268             .emit();
 269             self.bump();
 270         }
 271
 272         let (pat, colon) = self.parse_pat_before_ty(None, RecoverComma::Yes, "`let` bindings")?;
 273
 274         let (err, ty) = if colon {
 275             // Save the state of the parser before parsing type normally, in case there is a `:`
 276             // instead of an `=` typo.
 277             let parser_snapshot_before_type = self.clone();
 278             let colon_sp = self.prev_token.span;
 279             match self.parse_ty() {
 280                 Ok(ty) => (None, Some(ty)),
 281                 Err(mut err) => {
 282                     if let Ok(snip) = self.span_to_snippet(pat.span) {
 283                         err.span_label(pat.span, format!("while parsing the type for `{}`", snip));
 284                     }
 285                     // we use noexpect here because we don't actually expect Eq to be here
 286                     // but we are still checking for it in order to be able to handle it if
 287                     // it is there
 288                     let err = if self.check_noexpect(&token::Eq) {
 289                         err.emit();
 290                         None
 291                     } else {
 292                         // Rewind to before attempting to parse the type and continue parsing.
 293                         let parser_snapshot_after_type =
 294                             mem::replace(self, parser_snapshot_before_type);
 295                         Some((parser_snapshot_after_type, colon_sp, err))
 296                     };
 297                     (err, None)
 298                 }
 299             }
 300         } else {
 301             (None, None)
 302         };
 303         let init = match (self.parse_initializer(err.is_some()), err) {
 304             (Ok(init), None) => {
 305                 // init parsed, ty parsed
 306                 init
 307             }
 308             (Ok(init), Some((_, colon_sp, mut err))) => {
 309                 // init parsed, ty error
 310                 // Could parse the type as if it were the initializer, it is likely there was a
 311                 // typo in the code: `:` instead of `=`. Add suggestion and emit the error.
 312                 err.span_suggestion_short(
 313                     colon_sp,
 314                     "use `=` if you meant to assign",
 315                     " =",
 316                     Applicability::MachineApplicable,
 317                 );
 318                 err.emit();
 319                 // As this was parsed successfully, continue as if the code has been fixed for the
 320                 // rest of the file. It will still fail due to the emitted error, but we avoid
 321                 // extra noise.
 322                 init
 323             }
 324             (Err(init_err), Some((snapshot, _, ty_err))) => {
 325                 // init error, ty error
 326                 init_err.cancel();
 327                 // Couldn't parse the type nor the initializer, only raise the type error and
 328                 // return to the parser state before parsing the type as the initializer.
 329                 // let x: <parse_error>;
 330                 *self = snapshot;
 331                 return Err(ty_err);
 332             }
 333             (Err(err), None) => {
 334                 // init error, ty parsed
 335                 // Couldn't parse the initializer and we're not attempting to recover a failed
 336                 // parse of the type, return the error.
 337                 return Err(err);
 338             }
 339         };
 340         let kind = match init {
 341             None => LocalKind::Decl,
 342             Some(init) => {
 343                 if self.eat_keyword(kw::Else) {
 344                     if self.token.is_keyword(kw::If) {
 345                         // `let...else if`. Emit the same error that `parse_block()` would,
 346                         // but explicitly point out that this pattern is not allowed.
 347                         let msg = "conditional `else if` is not supported for `let...else`";
 348                         return Err(self.error_block_no_opening_brace_msg(msg));
 349                     }
 350                     let els = self.parse_block()?;
 351                     self.check_let_else_init_bool_expr(&init);
 352                     self.check_let_else_init_trailing_brace(&init);
 353                     LocalKind::InitElse(init, els)
 354                 } else {
 355                     LocalKind::Init(init)
 356                 }
 357             }
 358         };
 359         let hi = if self.token == token::Semi { self.token.span } else { self.prev_token.span };
 360         Ok(P(ast::Local { ty, pat, kind, id: DUMMY_NODE_ID, span: lo.to(hi), attrs, tokens: None }))
 361     }
 362
 363     fn check_let_else_init_bool_expr(&self, init: &ast::Expr) {
 364         if let ast::ExprKind::Binary(op, ..) = init.kind {
 365             if op.node.lazy() {
 366                 let suggs = vec![
 367                     (init.span.shrink_to_lo(), "(".to_string()),
 368                     (init.span.shrink_to_hi(), ")".to_string()),
 369                 ];
 370                 self.struct_span_err(
 371                     init.span,
 372                     &format!(
 373                         "a `{}` expression cannot be directly assigned in `let...else`",
 374                         op.node.to_string()
 375                     ),
 376                 )
 377                 .multipart_suggestion(
 378                     "wrap the expression in parentheses",
 379                     suggs,
 380                     Applicability::MachineApplicable,
 381                 )
 382                 .emit();
 383             }
 384         }
 385     }
 386
 387     fn check_let_else_init_trailing_brace(&self, init: &ast::Expr) {
 388         if let Some(trailing) = classify::expr_trailing_brace(init) {
 389             let err_span = trailing.span.with_lo(trailing.span.hi() - BytePos(1));
 390             let suggs = vec![
 391                 (trailing.span.shrink_to_lo(), "(".to_string()),
 392                 (trailing.span.shrink_to_hi(), ")".to_string()),
 393             ];
 394             self.struct_span_err(
 395                 err_span,
 396                 "right curly brace `}` before `else` in a `let...else` statement not allowed",
 397             )
 398             .multipart_suggestion(
 399                 "try wrapping the expression in parentheses",
 400                 suggs,
 401                 Applicability::MachineApplicable,
 402             )
 403             .emit();
 404         }
 405     }
 406
 407     /// Parses the RHS of a local variable declaration (e.g., `= 14;`).
 408     fn parse_initializer(&mut self, eq_optional: bool) -> PResult<'a, Option<P<Expr>>> {
 409         let eq_consumed = match self.token.kind {
 410             token::BinOpEq(..) => {
 411                 // Recover `let x <op>= 1` as `let x = 1`
 412                 self.struct_span_err(
 413                     self.token.span,
 414                     "can't reassign to an uninitialized variable",
 415                 )
 416                 .span_suggestion_short(
 417                     self.token.span,
 418                     "initialize the variable",
 419                     "=",
 420                     Applicability::MaybeIncorrect,
 421                 )
 422                 .help("if you meant to overwrite, remove the `let` binding")
 423                 .emit();
 424                 self.bump();
 425                 true
 426             }
 427             _ => self.eat(&token::Eq),
 428         };
 429
 430         Ok(if eq_consumed || eq_optional { Some(self.parse_expr()?) } else { None })
 431     }
 432
 433     /// Parses a block. No inner attributes are allowed.
 434     pub(super) fn parse_block(&mut self) -> PResult<'a, P<Block>> {
 435         let (attrs, block) = self.parse_inner_attrs_and_block()?;
 436         if let [.., last] = &*attrs {
 437             self.error_on_forbidden_inner_attr(last.span, DEFAULT_INNER_ATTR_FORBIDDEN);
 438         }
 439         Ok(block)
 440     }
 441
 442     fn error_block_no_opening_brace_msg(
 443         &mut self,
 444         msg: &str,
 445     ) -> DiagnosticBuilder<'a, ErrorGuaranteed> {
 446         let sp = self.token.span;
 447         let mut e = self.struct_span_err(sp, msg);
 448         let do_not_suggest_help = self.token.is_keyword(kw::In) || self.token == token::Colon;
 449
 450         // Check to see if the user has written something like
 451         //
 452         //    if (cond)
 453         //      bar;
 454         //
 455         // which is valid in other languages, but not Rust.
 456         match self.parse_stmt_without_recovery(false, ForceCollect::No) {
 457             // If the next token is an open brace, e.g., we have:
 458             //
 459             //     if expr other_expr {
 460             //        ^    ^          ^- lookahead(1) is a brace
 461             //        |    |- current token is not "else"
 462             //        |- (statement we just parsed)
 463             //
 464             // the place-inside-a-block suggestion would be more likely wrong than right.
 465             //
 466             // FIXME(compiler-errors): this should probably parse an arbitrary expr and not
 467             // just lookahead one token, so we can see if there's a brace after _that_,
 468             // since we want to protect against:
 469             //     `if 1 1 + 1 {` being suggested as  `if { 1 } 1 + 1 {`
 470             //                                            +   +
 471             Ok(Some(_))
 472                 if (!self.token.is_keyword(kw::Else)
 473                     && self.look_ahead(1, |t| t == &token::OpenDelim(Delimiter::Brace)))
 474                     || do_not_suggest_help => {}
 475             // Do not suggest `if foo println!("") {;}` (as would be seen in test for #46836).
 476             Ok(Some(Stmt { kind: StmtKind::Empty, .. })) => {}
 477             Ok(Some(stmt)) => {
 478                 let stmt_own_line = self.sess.source_map().is_line_before_span_empty(sp);
 479                 let stmt_span = if stmt_own_line && self.eat(&token::Semi) {
 480                     // Expand the span to include the semicolon.
 481                     stmt.span.with_hi(self.prev_token.span.hi())
 482                 } else {
 483                     stmt.span
 484                 };
 485                 e.multipart_suggestion(
 486                     "try placing this code inside a block",
 487                     vec![
 488                         (stmt_span.shrink_to_lo(), "{ ".to_string()),
 489                         (stmt_span.shrink_to_hi(), " }".to_string()),
 490                     ],
 491                     // Speculative; has been misleading in the past (#46836).
 492                     Applicability::MaybeIncorrect,
 493                 );
 494             }
 495             Err(e) => {
 496                 self.recover_stmt_(SemiColonMode::Break, BlockMode::Ignore);
 497                 e.cancel();
 498             }
 499             _ => {}
 500         }
 501         e.span_label(sp, "expected `{`");
 502         e
 503     }
 504
 505     fn error_block_no_opening_brace<T>(&mut self) -> PResult<'a, T> {
 506         let tok = super::token_descr(&self.token);
 507         let msg = format!("expected `{{`, found {}", tok);
 508         Err(self.error_block_no_opening_brace_msg(&msg))
 509     }
 510
 511     /// Parses a block. Inner attributes are allowed.
 512     pub(super) fn parse_inner_attrs_and_block(&mut self) -> PResult<'a, (AttrVec, P<Block>)> {
 513         self.parse_block_common(self.token.span, BlockCheckMode::Default)
 514     }
 515
 516     /// Parses a block. Inner attributes are allowed.
 517     pub(super) fn parse_block_common(
 518         &mut self,
 519         lo: Span,
 520         blk_mode: BlockCheckMode,
 521     ) -> PResult<'a, (AttrVec, P<Block>)> {
 522         maybe_whole!(self, NtBlock, |x| (AttrVec::new(), x));
 523
 524         self.maybe_recover_unexpected_block_label();
 525         if !self.eat(&token::OpenDelim(Delimiter::Brace)) {
 526             return self.error_block_no_opening_brace();
 527         }
 528
 529         let attrs = self.parse_inner_attributes()?;
 530         let tail = match self.maybe_suggest_struct_literal(lo, blk_mode) {
 531             Some(tail) => tail?,
 532             None => self.parse_block_tail(lo, blk_mode, AttemptLocalParseRecovery::Yes)?,
 533         };
 534         Ok((attrs, tail))
 535     }
 536
 537     /// Parses the rest of a block expression or function body.
 538     /// Precondition: already parsed the '{'.
 539     pub(crate) fn parse_block_tail(
 540         &mut self,
 541         lo: Span,
 542         s: BlockCheckMode,
 543         recover: AttemptLocalParseRecovery,
 544     ) -> PResult<'a, P<Block>> {
 545         let mut stmts = vec![];
 546         while !self.eat(&token::CloseDelim(Delimiter::Brace)) {
 547             if self.token == token::Eof {
 548                 break;
 549             }
 550             let stmt = match self.parse_full_stmt(recover) {
 551                 Err(mut err) if recover.yes() => {
 552                     self.maybe_annotate_with_ascription(&mut err, false);
 553                     err.emit();
 554                     self.recover_stmt_(SemiColonMode::Ignore, BlockMode::Ignore);
 555                     Some(self.mk_stmt_err(self.token.span))
 556                 }
 557                 Ok(stmt) => stmt,
 558                 Err(err) => return Err(err),
 559             };
 560             if let Some(stmt) = stmt {
 561                 stmts.push(stmt);
 562             } else {
 563                 // Found only `;` or `}`.
 564                 continue;
 565             };
 566         }
 567         Ok(self.mk_block(stmts, s, lo.to(self.prev_token.span)))
 568     }
 569
 570     /// Parses a statement, including the trailing semicolon.
 571     pub fn parse_full_stmt(
 572         &mut self,
 573         recover: AttemptLocalParseRecovery,
 574     ) -> PResult<'a, Option<Stmt>> {
 575         // Skip looking for a trailing semicolon when we have an interpolated statement.
 576         maybe_whole!(self, NtStmt, |x| Some(x.into_inner()));
 577
 578         let Some(mut stmt) = self.parse_stmt_without_recovery(true, ForceCollect::No)? else {
 579             return Ok(None);
 580         };
 581
 582         let mut eat_semi = true;
 583         match stmt.kind {
 584             // Expression without semicolon.
 585             StmtKind::Expr(ref mut expr)
 586                 if self.token != token::Eof && classify::expr_requires_semi_to_be_stmt(expr) =>
 587             {
 588                 // Just check for errors and recover; do not eat semicolon yet.
 589                 if let Err(mut e) =
 590                     self.expect_one_of(&[], &[token::Semi, token::CloseDelim(Delimiter::Brace)])
 591                 {
 592                     if let TokenKind::DocComment(..) = self.token.kind {
 593                         if let Ok(snippet) = self.span_to_snippet(self.token.span) {
 594                             let sp = self.token.span;
 595                             let marker = &snippet[..3];
 596                             let (comment_marker, doc_comment_marker) = marker.split_at(2);
 597
 598                             e.span_suggestion(
 599                                 sp.with_hi(sp.lo() + BytePos(marker.len() as u32)),
 600                                 &format!(
 601                                     "add a space before `{}` to use a regular comment",
 602                                     doc_comment_marker,
 603                                 ),
 604                                 format!("{} {}", comment_marker, doc_comment_marker),
 605                                 Applicability::MaybeIncorrect,
 606                             );
 607                         }
 608                     }
 609                     if let Err(mut e) =
 610                         self.check_mistyped_turbofish_with_multiple_type_params(e, expr)
 611                     {
 612                         if recover.no() {
 613                             return Err(e);
 614                         }
 615                         e.emit();
 616                         self.recover_stmt();
 617                     }
 618                     // Don't complain about type errors in body tail after parse error (#57383).
 619                     let sp = expr.span.to(self.prev_token.span);
 620                     *expr = self.mk_expr_err(sp);
 621                 }
 622             }
 623             StmtKind::Expr(_) | StmtKind::MacCall(_) => {}
 624             StmtKind::Local(ref mut local) if let Err(e) = self.expect_semi() => {
 625                 // We might be at the `,` in `let x = foo<bar, baz>;`. Try to recover.
 626                 match &mut local.kind {
 627                     LocalKind::Init(expr) | LocalKind::InitElse(expr, _) => {
 628                         self.check_mistyped_turbofish_with_multiple_type_params(e, expr)?;
 629                         // We found `foo<bar, baz>`, have we fully recovered?
 630                         self.expect_semi()?;
 631                     }
 632                     LocalKind::Decl => return Err(e),
 633                 }
 634                 eat_semi = false;
 635             }
 636             StmtKind::Empty | StmtKind::Item(_) | StmtKind::Local(_) | StmtKind::Semi(_) => eat_semi = false,
 637         }
 638
 639         if eat_semi && self.eat(&token::Semi) {
 640             stmt = stmt.add_trailing_semicolon();
 641         }
 642         stmt.span = stmt.span.to(self.prev_token.span);
 643         Ok(Some(stmt))
 644     }
 645
 646     pub(super) fn mk_block(&self, stmts: Vec<Stmt>, rules: BlockCheckMode, span: Span) -> P<Block> {
 647         P(Block {
 648             stmts,
 649             id: DUMMY_NODE_ID,
 650             rules,
 651             span,
 652             tokens: None,
 653             could_be_bare_literal: false,
 654         })
 655     }
 656
 657     pub(super) fn mk_stmt(&self, span: Span, kind: StmtKind) -> Stmt {
 658         Stmt { id: DUMMY_NODE_ID, kind, span }
 659     }
 660
 661     pub(super) fn mk_stmt_err(&self, span: Span) -> Stmt {
 662         self.mk_stmt(span, StmtKind::Expr(self.mk_expr_err(span)))
 663     }
 664
 665     pub(super) fn mk_block_err(&self, span: Span) -> P<Block> {
 666         self.mk_block(vec![self.mk_stmt_err(span)], BlockCheckMode::Default, span)
 667     }
 668 }