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Commit | Line | Data |
---|---|---|
e74abb32 | 1 | pub mod attr; |
6a06907d | 2 | mod attr_wrapper; |
3dfed10e | 3 | mod diagnostics; |
416331ca | 4 | mod expr; |
3dfed10e | 5 | mod generics; |
416331ca | 6 | mod item; |
3dfed10e | 7 | mod nonterminal; |
dfeec247 | 8 | mod pat; |
416331ca | 9 | mod path; |
dfeec247 | 10 | mod stmt; |
3dfed10e | 11 | mod ty; |
416331ca | 12 | |
60c5eb7d | 13 | use crate::lexer::UnmatchedBrace; |
6a06907d | 14 | pub use attr_wrapper::AttrWrapper; |
29967ef6 | 15 | pub use diagnostics::AttemptLocalParseRecovery; |
3dfed10e | 16 | use diagnostics::Error; |
136023e0 | 17 | pub use pat::{RecoverColon, RecoverComma}; |
3dfed10e | 18 | pub use path::PathStyle; |
60c5eb7d | 19 | |
74b04a01 XL |
20 | use rustc_ast::ptr::P; |
21 | use rustc_ast::token::{self, DelimToken, Token, TokenKind}; | |
cdc7bbd5 | 22 | use rustc_ast::tokenstream::AttributesData; |
6a06907d | 23 | use rustc_ast::tokenstream::{self, DelimSpan, Spacing}; |
cdc7bbd5 XL |
24 | use rustc_ast::tokenstream::{TokenStream, TokenTree}; |
25 | use rustc_ast::AttrId; | |
3dfed10e | 26 | use rustc_ast::DUMMY_NODE_ID; |
6a06907d | 27 | use rustc_ast::{self as ast, AnonConst, AstLike, AttrStyle, AttrVec, Const, CrateSugar, Extern}; |
5869c6ff | 28 | use rustc_ast::{Async, Expr, ExprKind, MacArgs, MacDelimiter, Mutability, StrLit, Unsafe}; |
29967ef6 | 29 | use rustc_ast::{Visibility, VisibilityKind}; |
74b04a01 | 30 | use rustc_ast_pretty::pprust; |
cdc7bbd5 | 31 | use rustc_data_structures::fx::FxHashMap; |
fc512014 | 32 | use rustc_data_structures::sync::Lrc; |
29967ef6 XL |
33 | use rustc_errors::PResult; |
34 | use rustc_errors::{struct_span_err, Applicability, DiagnosticBuilder, FatalError}; | |
74b04a01 | 35 | use rustc_session::parse::ParseSess; |
1b1a35ee | 36 | use rustc_span::source_map::{Span, DUMMY_SP}; |
f9f354fc | 37 | use rustc_span::symbol::{kw, sym, Ident, Symbol}; |
3dfed10e | 38 | use tracing::debug; |
74b04a01 | 39 | |
cdc7bbd5 | 40 | use std::ops::Range; |
dfeec247 | 41 | use std::{cmp, mem, slice}; |
60c5eb7d | 42 | |
9fa01778 | 43 | bitflags::bitflags! { |
94b46f34 | 44 | struct Restrictions: u8 { |
ea8adc8c XL |
45 | const STMT_EXPR = 1 << 0; |
46 | const NO_STRUCT_LITERAL = 1 << 1; | |
29967ef6 | 47 | const CONST_EXPR = 1 << 2; |
1a4d82fc | 48 | } |
223e47cc LB |
49 | } |
50 | ||
8faf50e0 | 51 | #[derive(Clone, Copy, PartialEq, Debug)] |
e74abb32 | 52 | enum SemiColonMode { |
7453a54e SL |
53 | Break, |
54 | Ignore, | |
9fa01778 | 55 | Comma, |
7453a54e SL |
56 | } |
57 | ||
8faf50e0 | 58 | #[derive(Clone, Copy, PartialEq, Debug)] |
e74abb32 | 59 | enum BlockMode { |
cc61c64b XL |
60 | Break, |
61 | Ignore, | |
62 | } | |
63 | ||
5869c6ff XL |
64 | /// Whether or not we should force collection of tokens for an AST node, |
65 | /// regardless of whether or not it has attributes | |
17df50a5 | 66 | #[derive(Clone, Copy, PartialEq)] |
5869c6ff XL |
67 | pub enum ForceCollect { |
68 | Yes, | |
69 | No, | |
70 | } | |
71 | ||
cdc7bbd5 | 72 | #[derive(Debug, Eq, PartialEq)] |
5869c6ff XL |
73 | pub enum TrailingToken { |
74 | None, | |
75 | Semi, | |
6a06907d XL |
76 | /// If the trailing token is a comma, then capture it |
77 | /// Otherwise, ignore the trailing token | |
78 | MaybeComma, | |
5869c6ff XL |
79 | } |
80 | ||
e1599b0c | 81 | /// Like `maybe_whole_expr`, but for things other than expressions. |
416331ca | 82 | #[macro_export] |
1a4d82fc | 83 | macro_rules! maybe_whole { |
c30ab7b3 | 84 | ($p:expr, $constructor:ident, |$x:ident| $e:expr) => { |
dc9dc135 | 85 | if let token::Interpolated(nt) = &$p.token.kind { |
532ac7d7 XL |
86 | if let token::$constructor(x) = &**nt { |
87 | let $x = x.clone(); | |
c30ab7b3 SL |
88 | $p.bump(); |
89 | return Ok($e); | |
223e47cc | 90 | } |
1a4d82fc | 91 | } |
c30ab7b3 | 92 | }; |
1a4d82fc | 93 | } |
223e47cc | 94 | |
532ac7d7 | 95 | /// If the next tokens are ill-formed `$ty::` recover them as `<$ty>::`. |
416331ca | 96 | #[macro_export] |
532ac7d7 XL |
97 | macro_rules! maybe_recover_from_interpolated_ty_qpath { |
98 | ($self: expr, $allow_qpath_recovery: expr) => { | |
99 | if $allow_qpath_recovery && $self.look_ahead(1, |t| t == &token::ModSep) { | |
dc9dc135 | 100 | if let token::Interpolated(nt) = &$self.token.kind { |
532ac7d7 XL |
101 | if let token::NtTy(ty) = &**nt { |
102 | let ty = ty.clone(); | |
103 | $self.bump(); | |
74b04a01 | 104 | return $self.maybe_recover_from_bad_qpath_stage_2($self.prev_token.span, ty); |
532ac7d7 XL |
105 | } |
106 | } | |
107 | } | |
dfeec247 | 108 | }; |
532ac7d7 XL |
109 | } |
110 | ||
041b39d2 | 111 | #[derive(Clone)] |
1a4d82fc JJ |
112 | pub struct Parser<'a> { |
113 | pub sess: &'a ParseSess, | |
74b04a01 | 114 | /// The current token. |
dc9dc135 | 115 | pub token: Token, |
29967ef6 XL |
116 | /// The spacing for the current token |
117 | pub token_spacing: Spacing, | |
74b04a01 XL |
118 | /// The previous token. |
119 | pub prev_token: Token, | |
cdc7bbd5 | 120 | pub capture_cfg: bool, |
94b46f34 | 121 | restrictions: Restrictions, |
e74abb32 | 122 | expected_tokens: Vec<TokenType>, |
29967ef6 XL |
123 | // Important: This must only be advanced from `next_tok` |
124 | // to ensure that `token_cursor.num_next_calls` is updated properly | |
e1599b0c | 125 | token_cursor: TokenCursor, |
94b46f34 | 126 | desugar_doc_comments: bool, |
9fa01778 XL |
127 | /// This field is used to keep track of how many left angle brackets we have seen. This is |
128 | /// required in order to detect extra leading left angle brackets (`<` characters) and error | |
129 | /// appropriately. | |
130 | /// | |
131 | /// See the comments in the `parse_path_segment` function for more details. | |
e74abb32 XL |
132 | unmatched_angle_bracket_count: u32, |
133 | max_angle_bracket_count: u32, | |
e1599b0c | 134 | /// A list of all unclosed delimiters found by the lexer. If an entry is used for error recovery |
9fa01778 XL |
135 | /// it gets removed from here. Every entry left at the end gets emitted as an independent |
136 | /// error. | |
e74abb32 XL |
137 | pub(super) unclosed_delims: Vec<UnmatchedBrace>, |
138 | last_unexpected_token_span: Option<Span>, | |
3dfed10e XL |
139 | /// Span pointing at the `:` for the last type ascription the parser has seen, and whether it |
140 | /// looked like it could have been a mistyped path or literal `Option:Some(42)`). | |
e74abb32 | 141 | pub last_type_ascription: Option<(Span, bool /* likely path typo */)>, |
dc9dc135 | 142 | /// If present, this `Parser` is not parsing Rust code but rather a macro call. |
e74abb32 | 143 | subparser_name: Option<&'static str>, |
cdc7bbd5 XL |
144 | capture_state: CaptureState, |
145 | } | |
146 | ||
147 | /// Indicates a range of tokens that should be replaced by | |
148 | /// the tokens in the provided vector. This is used in two | |
149 | /// places during token collection: | |
150 | /// | |
151 | /// 1. During the parsing of an AST node that may have a `#[derive]` | |
152 | /// attribute, we parse a nested AST node that has `#[cfg]` or `#[cfg_attr]` | |
153 | /// In this case, we use a `ReplaceRange` to replace the entire inner AST node | |
154 | /// with `FlatToken::AttrTarget`, allowing us to perform eager cfg-expansion | |
155 | /// on a `AttrAnnotatedTokenStream` | |
156 | /// | |
157 | /// 2. When we parse an inner attribute while collecting tokens. We | |
158 | /// remove inner attributes from the token stream entirely, and | |
159 | /// instead track them through the `attrs` field on the AST node. | |
160 | /// This allows us to easily manipulate them (for example, removing | |
161 | /// the first macro inner attribute to invoke a proc-macro). | |
162 | /// When create a `TokenStream`, the inner attributes get inserted | |
163 | /// into the proper place in the token stream. | |
164 | pub type ReplaceRange = (Range<u32>, Vec<(FlatToken, Spacing)>); | |
165 | ||
166 | /// Controls how we capture tokens. Capturing can be expensive, | |
167 | /// so we try to avoid performing capturing in cases where | |
168 | /// we will never need a `AttrAnnotatedTokenStream` | |
169 | #[derive(Copy, Clone)] | |
170 | pub enum Capturing { | |
171 | /// We aren't performing any capturing - this is the default mode. | |
172 | No, | |
173 | /// We are capturing tokens | |
174 | Yes, | |
175 | } | |
176 | ||
177 | #[derive(Clone)] | |
178 | struct CaptureState { | |
179 | capturing: Capturing, | |
180 | replace_ranges: Vec<ReplaceRange>, | |
181 | inner_attr_ranges: FxHashMap<AttrId, ReplaceRange>, | |
1a4d82fc JJ |
182 | } |
183 | ||
9fa01778 XL |
184 | impl<'a> Drop for Parser<'a> { |
185 | fn drop(&mut self) { | |
e74abb32 | 186 | emit_unclosed_delims(&mut self.unclosed_delims, &self.sess); |
9fa01778 XL |
187 | } |
188 | } | |
7cac9316 | 189 | |
041b39d2 | 190 | #[derive(Clone)] |
e1599b0c XL |
191 | struct TokenCursor { |
192 | frame: TokenCursorFrame, | |
193 | stack: Vec<TokenCursorFrame>, | |
29967ef6 XL |
194 | desugar_doc_comments: bool, |
195 | // Counts the number of calls to `next` or `next_desugared`, | |
196 | // depending on whether `desugar_doc_comments` is set. | |
197 | num_next_calls: usize, | |
fc512014 XL |
198 | // During parsing, we may sometimes need to 'unglue' a |
199 | // glued token into two component tokens | |
200 | // (e.g. '>>' into '>' and '>), so that the parser | |
201 | // can consume them one at a time. This process | |
202 | // bypasses the normal capturing mechanism | |
203 | // (e.g. `num_next_calls` will not be incremented), | |
204 | // since the 'unglued' tokens due not exist in | |
205 | // the original `TokenStream`. | |
206 | // | |
207 | // If we end up consuming both unglued tokens, | |
208 | // then this is not an issue - we'll end up | |
209 | // capturing the single 'glued' token. | |
210 | // | |
211 | // However, in certain circumstances, we may | |
212 | // want to capture just the first 'unglued' token. | |
213 | // For example, capturing the `Vec<u8>` | |
214 | // in `Option<Vec<u8>>` requires us to unglue | |
cdc7bbd5 | 215 | // the trailing `>>` token. The `break_last_token` |
fc512014 XL |
216 | // field is used to track this token - it gets |
217 | // appended to the captured stream when | |
218 | // we evaluate a `LazyTokenStream` | |
cdc7bbd5 | 219 | break_last_token: bool, |
8bb4bdeb XL |
220 | } |
221 | ||
041b39d2 | 222 | #[derive(Clone)] |
e1599b0c XL |
223 | struct TokenCursorFrame { |
224 | delim: token::DelimToken, | |
225 | span: DelimSpan, | |
226 | open_delim: bool, | |
227 | tree_cursor: tokenstream::Cursor, | |
228 | close_delim: bool, | |
3b2f2976 XL |
229 | } |
230 | ||
8bb4bdeb | 231 | impl TokenCursorFrame { |
29967ef6 | 232 | fn new(span: DelimSpan, delim: DelimToken, tts: TokenStream) -> Self { |
8bb4bdeb | 233 | TokenCursorFrame { |
dc9dc135 XL |
234 | delim, |
235 | span, | |
cdc7bbd5 | 236 | open_delim: false, |
29967ef6 | 237 | tree_cursor: tts.into_trees(), |
cdc7bbd5 | 238 | close_delim: false, |
8bb4bdeb XL |
239 | } |
240 | } | |
241 | } | |
242 | ||
243 | impl TokenCursor { | |
29967ef6 | 244 | fn next(&mut self) -> (Token, Spacing) { |
8bb4bdeb | 245 | loop { |
29967ef6 | 246 | let (tree, spacing) = if !self.frame.open_delim { |
8bb4bdeb | 247 | self.frame.open_delim = true; |
f9f354fc | 248 | TokenTree::open_tt(self.frame.span, self.frame.delim).into() |
1b1a35ee | 249 | } else if let Some(tree) = self.frame.tree_cursor.next_with_spacing() { |
8bb4bdeb XL |
250 | tree |
251 | } else if !self.frame.close_delim { | |
252 | self.frame.close_delim = true; | |
f9f354fc | 253 | TokenTree::close_tt(self.frame.span, self.frame.delim).into() |
8bb4bdeb XL |
254 | } else if let Some(frame) = self.stack.pop() { |
255 | self.frame = frame; | |
dfeec247 | 256 | continue; |
8bb4bdeb | 257 | } else { |
29967ef6 | 258 | (TokenTree::Token(Token::new(token::Eof, DUMMY_SP)), Spacing::Alone) |
8bb4bdeb XL |
259 | }; |
260 | ||
29967ef6 XL |
261 | match tree { |
262 | TokenTree::Token(token) => { | |
263 | return (token, spacing); | |
f9f354fc | 264 | } |
0731742a | 265 | TokenTree::Delimited(sp, delim, tts) => { |
29967ef6 | 266 | let frame = TokenCursorFrame::new(sp, delim, tts); |
8bb4bdeb XL |
267 | self.stack.push(mem::replace(&mut self.frame, frame)); |
268 | } | |
269 | } | |
270 | } | |
271 | } | |
272 | ||
29967ef6 | 273 | fn next_desugared(&mut self) -> (Token, Spacing) { |
3dfed10e | 274 | let (data, attr_style, sp) = match self.next() { |
29967ef6 | 275 | (Token { kind: token::DocComment(_, attr_style, data), span }, _) => { |
3dfed10e XL |
276 | (data, attr_style, span) |
277 | } | |
7cac9316 | 278 | tok => return tok, |
8bb4bdeb XL |
279 | }; |
280 | ||
8bb4bdeb XL |
281 | // Searches for the occurrences of `"#*` and returns the minimum number of `#`s |
282 | // required to wrap the text. | |
283 | let mut num_of_hashes = 0; | |
284 | let mut count = 0; | |
3dfed10e | 285 | for ch in data.as_str().chars() { |
8bb4bdeb XL |
286 | count = match ch { |
287 | '"' => 1, | |
288 | '#' if count > 0 => count + 1, | |
289 | _ => 0, | |
290 | }; | |
291 | num_of_hashes = cmp::max(num_of_hashes, count); | |
292 | } | |
293 | ||
b7449926 | 294 | let delim_span = DelimSpan::from_single(sp); |
0731742a XL |
295 | let body = TokenTree::Delimited( |
296 | delim_span, | |
297 | token::Bracket, | |
dc9dc135 XL |
298 | [ |
299 | TokenTree::token(token::Ident(sym::doc, false), sp), | |
300 | TokenTree::token(token::Eq, sp), | |
3dfed10e | 301 | TokenTree::token(TokenKind::lit(token::StrRaw(num_of_hashes), data, None), sp), |
0731742a | 302 | ] |
dfeec247 XL |
303 | .iter() |
304 | .cloned() | |
74b04a01 | 305 | .collect::<TokenStream>(), |
0731742a | 306 | ); |
8bb4bdeb | 307 | |
dfeec247 XL |
308 | self.stack.push(mem::replace( |
309 | &mut self.frame, | |
310 | TokenCursorFrame::new( | |
311 | delim_span, | |
312 | token::NoDelim, | |
29967ef6 | 313 | if attr_style == AttrStyle::Inner { |
dfeec247 XL |
314 | [TokenTree::token(token::Pound, sp), TokenTree::token(token::Not, sp), body] |
315 | .iter() | |
316 | .cloned() | |
317 | .collect::<TokenStream>() | |
318 | } else { | |
319 | [TokenTree::token(token::Pound, sp), body] | |
320 | .iter() | |
321 | .cloned() | |
322 | .collect::<TokenStream>() | |
323 | }, | |
324 | ), | |
325 | )); | |
8bb4bdeb XL |
326 | |
327 | self.next() | |
328 | } | |
329 | } | |
330 | ||
5869c6ff | 331 | #[derive(Debug, Clone, PartialEq)] |
e74abb32 | 332 | enum TokenType { |
dc9dc135 XL |
333 | Token(TokenKind), |
334 | Keyword(Symbol), | |
1a4d82fc | 335 | Operator, |
32a655c1 SL |
336 | Lifetime, |
337 | Ident, | |
338 | Path, | |
339 | Type, | |
9fa01778 | 340 | Const, |
1a4d82fc | 341 | } |
223e47cc | 342 | |
1a4d82fc | 343 | impl TokenType { |
e74abb32 | 344 | fn to_string(&self) -> String { |
1a4d82fc | 345 | match *self { |
dc9dc135 XL |
346 | TokenType::Token(ref t) => format!("`{}`", pprust::token_kind_to_string(t)), |
347 | TokenType::Keyword(kw) => format!("`{}`", kw), | |
32a655c1 SL |
348 | TokenType::Operator => "an operator".to_string(), |
349 | TokenType::Lifetime => "lifetime".to_string(), | |
350 | TokenType::Ident => "identifier".to_string(), | |
351 | TokenType::Path => "path".to_string(), | |
352 | TokenType::Type => "type".to_string(), | |
fc512014 | 353 | TokenType::Const => "a const expression".to_string(), |
1a4d82fc JJ |
354 | } |
355 | } | |
223e47cc LB |
356 | } |
357 | ||
8faf50e0 | 358 | #[derive(Copy, Clone, Debug)] |
e74abb32 | 359 | enum TokenExpectType { |
ea8adc8c XL |
360 | Expect, |
361 | NoExpect, | |
362 | } | |
363 | ||
e74abb32 XL |
364 | /// A sequence separator. |
365 | struct SeqSep { | |
366 | /// The separator token. | |
367 | sep: Option<TokenKind>, | |
368 | /// `true` if a trailing separator is allowed. | |
369 | trailing_sep_allowed: bool, | |
370 | } | |
371 | ||
372 | impl SeqSep { | |
373 | fn trailing_allowed(t: TokenKind) -> SeqSep { | |
dfeec247 | 374 | SeqSep { sep: Some(t), trailing_sep_allowed: true } |
e74abb32 XL |
375 | } |
376 | ||
377 | fn none() -> SeqSep { | |
dfeec247 | 378 | SeqSep { sep: None, trailing_sep_allowed: false } |
e74abb32 XL |
379 | } |
380 | } | |
381 | ||
dfeec247 XL |
382 | pub enum FollowedByType { |
383 | Yes, | |
384 | No, | |
385 | } | |
386 | ||
387 | fn token_descr_opt(token: &Token) -> Option<&'static str> { | |
388 | Some(match token.kind { | |
389 | _ if token.is_special_ident() => "reserved identifier", | |
390 | _ if token.is_used_keyword() => "keyword", | |
391 | _ if token.is_unused_keyword() => "reserved keyword", | |
392 | token::DocComment(..) => "doc comment", | |
393 | _ => return None, | |
394 | }) | |
395 | } | |
396 | ||
397 | pub(super) fn token_descr(token: &Token) -> String { | |
398 | let token_str = pprust::token_to_string(token); | |
399 | match token_descr_opt(token) { | |
400 | Some(prefix) => format!("{} `{}`", prefix, token_str), | |
401 | _ => format!("`{}`", token_str), | |
402 | } | |
403 | } | |
60c5eb7d | 404 | |
1a4d82fc | 405 | impl<'a> Parser<'a> { |
dc9dc135 XL |
406 | pub fn new( |
407 | sess: &'a ParseSess, | |
408 | tokens: TokenStream, | |
dc9dc135 XL |
409 | desugar_doc_comments: bool, |
410 | subparser_name: Option<&'static str>, | |
411 | ) -> Self { | |
cdc7bbd5 XL |
412 | let mut start_frame = TokenCursorFrame::new(DelimSpan::dummy(), token::NoDelim, tokens); |
413 | start_frame.open_delim = true; | |
414 | start_frame.close_delim = true; | |
415 | ||
c30ab7b3 | 416 | let mut parser = Parser { |
3b2f2976 | 417 | sess, |
dc9dc135 | 418 | token: Token::dummy(), |
29967ef6 | 419 | token_spacing: Spacing::Alone, |
74b04a01 | 420 | prev_token: Token::dummy(), |
cdc7bbd5 | 421 | capture_cfg: false, |
d9579d0f | 422 | restrictions: Restrictions::empty(), |
1a4d82fc | 423 | expected_tokens: Vec::new(), |
8bb4bdeb | 424 | token_cursor: TokenCursor { |
cdc7bbd5 | 425 | frame: start_frame, |
8bb4bdeb | 426 | stack: Vec::new(), |
29967ef6 XL |
427 | num_next_calls: 0, |
428 | desugar_doc_comments, | |
cdc7bbd5 | 429 | break_last_token: false, |
8bb4bdeb | 430 | }, |
3b2f2976 | 431 | desugar_doc_comments, |
9fa01778 XL |
432 | unmatched_angle_bracket_count: 0, |
433 | max_angle_bracket_count: 0, | |
434 | unclosed_delims: Vec::new(), | |
435 | last_unexpected_token_span: None, | |
416331ca | 436 | last_type_ascription: None, |
dc9dc135 | 437 | subparser_name, |
cdc7bbd5 XL |
438 | capture_state: CaptureState { |
439 | capturing: Capturing::No, | |
440 | replace_ranges: Vec::new(), | |
441 | inner_attr_ranges: Default::default(), | |
442 | }, | |
c30ab7b3 SL |
443 | }; |
444 | ||
74b04a01 XL |
445 | // Make parser point to the first token. |
446 | parser.bump(); | |
7cac9316 | 447 | |
c30ab7b3 SL |
448 | parser |
449 | } | |
450 | ||
29967ef6 | 451 | fn next_tok(&mut self, fallback_span: Span) -> (Token, Spacing) { |
cdc7bbd5 XL |
452 | loop { |
453 | let (mut next, spacing) = if self.desugar_doc_comments { | |
454 | self.token_cursor.next_desugared() | |
455 | } else { | |
456 | self.token_cursor.next() | |
457 | }; | |
458 | self.token_cursor.num_next_calls += 1; | |
459 | // We've retrieved an token from the underlying | |
460 | // cursor, so we no longer need to worry about | |
461 | // an unglued token. See `break_and_eat` for more details | |
462 | self.token_cursor.break_last_token = false; | |
463 | if next.span.is_dummy() { | |
464 | // Tweak the location for better diagnostics, but keep syntactic context intact. | |
465 | next.span = fallback_span.with_ctxt(next.span.ctxt()); | |
466 | } | |
467 | if matches!( | |
468 | next.kind, | |
469 | token::OpenDelim(token::NoDelim) | token::CloseDelim(token::NoDelim) | |
470 | ) { | |
471 | continue; | |
472 | } | |
473 | return (next, spacing); | |
1a4d82fc JJ |
474 | } |
475 | } | |
476 | ||
29967ef6 | 477 | pub fn unexpected<T>(&mut self) -> PResult<'a, T> { |
9346a6ac | 478 | match self.expect_one_of(&[], &[]) { |
9cc50fc6 | 479 | Err(e) => Err(e), |
e74abb32 XL |
480 | // We can get `Ok(true)` from `recover_closing_delimiter` |
481 | // which is called in `expected_one_of_not_found`. | |
482 | Ok(_) => FatalError.raise(), | |
9346a6ac | 483 | } |
1a4d82fc JJ |
484 | } |
485 | ||
9fa01778 | 486 | /// Expects and consumes the token `t`. Signals an error if the next token is not `t`. |
dc9dc135 | 487 | pub fn expect(&mut self, t: &TokenKind) -> PResult<'a, bool /* recovered */> { |
1a4d82fc JJ |
488 | if self.expected_tokens.is_empty() { |
489 | if self.token == *t { | |
9cc50fc6 | 490 | self.bump(); |
9fa01778 | 491 | Ok(false) |
1a4d82fc | 492 | } else { |
dc9dc135 | 493 | self.unexpected_try_recover(t) |
1a4d82fc JJ |
494 | } |
495 | } else { | |
94b46f34 | 496 | self.expect_one_of(slice::from_ref(t), &[]) |
1a4d82fc JJ |
497 | } |
498 | } | |
499 | ||
500 | /// Expect next token to be edible or inedible token. If edible, | |
501 | /// then consume it; if inedible, then return without consuming | |
502 | /// anything. Signal a fatal error if next token is unexpected. | |
9fa01778 XL |
503 | pub fn expect_one_of( |
504 | &mut self, | |
dc9dc135 XL |
505 | edible: &[TokenKind], |
506 | inedible: &[TokenKind], | |
9fa01778 | 507 | ) -> PResult<'a, bool /* recovered */> { |
dc9dc135 | 508 | if edible.contains(&self.token.kind) { |
9cc50fc6 | 509 | self.bump(); |
9fa01778 | 510 | Ok(false) |
dc9dc135 | 511 | } else if inedible.contains(&self.token.kind) { |
1a4d82fc | 512 | // leave it in the input |
9fa01778 | 513 | Ok(false) |
dc9dc135 | 514 | } else if self.last_unexpected_token_span == Some(self.token.span) { |
9fa01778 | 515 | FatalError.raise(); |
1a4d82fc | 516 | } else { |
dc9dc135 | 517 | self.expected_one_of_not_found(edible, inedible) |
1a4d82fc | 518 | } |
970d7e83 LB |
519 | } |
520 | ||
dfeec247 | 521 | // Public for rustfmt usage. |
f9f354fc | 522 | pub fn parse_ident(&mut self) -> PResult<'a, Ident> { |
2c00a5a8 XL |
523 | self.parse_ident_common(true) |
524 | } | |
525 | ||
17df50a5 XL |
526 | fn ident_or_err(&mut self) -> PResult<'a, (Ident, /* is_raw */ bool)> { |
527 | self.token.ident().ok_or_else(|| match self.prev_token.kind { | |
528 | TokenKind::DocComment(..) => { | |
529 | self.span_err(self.prev_token.span, Error::UselessDocComment) | |
530 | } | |
531 | _ => self.expected_ident_found(), | |
532 | }) | |
533 | } | |
534 | ||
f9f354fc | 535 | fn parse_ident_common(&mut self, recover: bool) -> PResult<'a, Ident> { |
17df50a5 XL |
536 | let (ident, is_raw) = self.ident_or_err()?; |
537 | if !is_raw && ident.is_reserved() { | |
538 | let mut err = self.expected_ident_found(); | |
539 | if recover { | |
540 | err.emit(); | |
541 | } else { | |
542 | return Err(err); | |
970d7e83 | 543 | } |
970d7e83 | 544 | } |
17df50a5 XL |
545 | self.bump(); |
546 | Ok(ident) | |
970d7e83 LB |
547 | } |
548 | ||
9fa01778 | 549 | /// Checks if the next token is `tok`, and returns `true` if so. |
1a4d82fc | 550 | /// |
7453a54e | 551 | /// This method will automatically add `tok` to `expected_tokens` if `tok` is not |
1a4d82fc | 552 | /// encountered. |
e74abb32 | 553 | fn check(&mut self, tok: &TokenKind) -> bool { |
1a4d82fc | 554 | let is_present = self.token == *tok; |
dfeec247 XL |
555 | if !is_present { |
556 | self.expected_tokens.push(TokenType::Token(tok.clone())); | |
557 | } | |
1a4d82fc | 558 | is_present |
970d7e83 LB |
559 | } |
560 | ||
9fa01778 | 561 | /// Consumes a token 'tok' if it exists. Returns whether the given token was present. |
dc9dc135 | 562 | pub fn eat(&mut self, tok: &TokenKind) -> bool { |
1a4d82fc | 563 | let is_present = self.check(tok); |
dfeec247 XL |
564 | if is_present { |
565 | self.bump() | |
566 | } | |
9cc50fc6 | 567 | is_present |
970d7e83 LB |
568 | } |
569 | ||
e74abb32 XL |
570 | /// If the next token is the given keyword, returns `true` without eating it. |
571 | /// An expectation is also added for diagnostics purposes. | |
dc9dc135 | 572 | fn check_keyword(&mut self, kw: Symbol) -> bool { |
85aaf69f SL |
573 | self.expected_tokens.push(TokenType::Keyword(kw)); |
574 | self.token.is_keyword(kw) | |
575 | } | |
576 | ||
e74abb32 XL |
577 | /// If the next token is the given keyword, eats it and returns `true`. |
578 | /// Otherwise, returns `false`. An expectation is also added for diagnostics purposes. | |
dfeec247 XL |
579 | // Public for rustfmt usage. |
580 | pub fn eat_keyword(&mut self, kw: Symbol) -> bool { | |
85aaf69f | 581 | if self.check_keyword(kw) { |
9cc50fc6 SL |
582 | self.bump(); |
583 | true | |
85aaf69f | 584 | } else { |
9cc50fc6 | 585 | false |
85aaf69f SL |
586 | } |
587 | } | |
588 | ||
dc9dc135 | 589 | fn eat_keyword_noexpect(&mut self, kw: Symbol) -> bool { |
1a4d82fc | 590 | if self.token.is_keyword(kw) { |
9cc50fc6 SL |
591 | self.bump(); |
592 | true | |
1a4d82fc | 593 | } else { |
9cc50fc6 | 594 | false |
1a4d82fc | 595 | } |
970d7e83 LB |
596 | } |
597 | ||
9fa01778 XL |
598 | /// If the given word is not a keyword, signals an error. |
599 | /// If the next token is not the given word, signals an error. | |
600 | /// Otherwise, eats it. | |
dc9dc135 | 601 | fn expect_keyword(&mut self, kw: Symbol) -> PResult<'a, ()> { |
dfeec247 | 602 | if !self.eat_keyword(kw) { self.unexpected() } else { Ok(()) } |
970d7e83 LB |
603 | } |
604 | ||
74b04a01 XL |
605 | /// Is the given keyword `kw` followed by a non-reserved identifier? |
606 | fn is_kw_followed_by_ident(&self, kw: Symbol) -> bool { | |
607 | self.token.is_keyword(kw) && self.look_ahead(1, |t| t.is_ident() && !t.is_reserved_ident()) | |
608 | } | |
609 | ||
e74abb32 XL |
610 | fn check_or_expected(&mut self, ok: bool, typ: TokenType) -> bool { |
611 | if ok { | |
32a655c1 SL |
612 | true |
613 | } else { | |
e74abb32 | 614 | self.expected_tokens.push(typ); |
32a655c1 SL |
615 | false |
616 | } | |
617 | } | |
618 | ||
e74abb32 XL |
619 | fn check_ident(&mut self) -> bool { |
620 | self.check_or_expected(self.token.is_ident(), TokenType::Ident) | |
621 | } | |
622 | ||
32a655c1 | 623 | fn check_path(&mut self) -> bool { |
e74abb32 | 624 | self.check_or_expected(self.token.is_path_start(), TokenType::Path) |
32a655c1 SL |
625 | } |
626 | ||
627 | fn check_type(&mut self) -> bool { | |
e74abb32 | 628 | self.check_or_expected(self.token.can_begin_type(), TokenType::Type) |
32a655c1 SL |
629 | } |
630 | ||
9fa01778 | 631 | fn check_const_arg(&mut self) -> bool { |
e74abb32 XL |
632 | self.check_or_expected(self.token.can_begin_const_arg(), TokenType::Const) |
633 | } | |
634 | ||
29967ef6 XL |
635 | fn check_inline_const(&self, dist: usize) -> bool { |
636 | self.is_keyword_ahead(dist, &[kw::Const]) | |
637 | && self.look_ahead(dist + 1, |t| match t.kind { | |
638 | token::Interpolated(ref nt) => matches!(**nt, token::NtBlock(..)), | |
639 | token::OpenDelim(DelimToken::Brace) => true, | |
640 | _ => false, | |
641 | }) | |
642 | } | |
643 | ||
e74abb32 XL |
644 | /// Checks to see if the next token is either `+` or `+=`. |
645 | /// Otherwise returns `false`. | |
646 | fn check_plus(&mut self) -> bool { | |
647 | self.check_or_expected( | |
648 | self.token.is_like_plus(), | |
649 | TokenType::Token(token::BinOp(token::Plus)), | |
650 | ) | |
9fa01778 XL |
651 | } |
652 | ||
74b04a01 XL |
653 | /// Eats the expected token if it's present possibly breaking |
654 | /// compound tokens like multi-character operators in process. | |
655 | /// Returns `true` if the token was eaten. | |
656 | fn break_and_eat(&mut self, expected: TokenKind) -> bool { | |
657 | if self.token.kind == expected { | |
658 | self.bump(); | |
659 | return true; | |
660 | } | |
661 | match self.token.kind.break_two_token_op() { | |
662 | Some((first, second)) if first == expected => { | |
663 | let first_span = self.sess.source_map().start_point(self.token.span); | |
664 | let second_span = self.token.span.with_lo(first_span.hi()); | |
665 | self.token = Token::new(first, first_span); | |
fc512014 XL |
666 | // Keep track of this token - if we end token capturing now, |
667 | // we'll want to append this token to the captured stream. | |
668 | // | |
669 | // If we consume any additional tokens, then this token | |
670 | // is not needed (we'll capture the entire 'glued' token), | |
671 | // and `next_tok` will set this field to `None` | |
cdc7bbd5 | 672 | self.token_cursor.break_last_token = true; |
29967ef6 XL |
673 | // Use the spacing of the glued token as the spacing |
674 | // of the unglued second token. | |
675 | self.bump_with((Token::new(second, second_span), self.token_spacing)); | |
94b46f34 XL |
676 | true |
677 | } | |
74b04a01 XL |
678 | _ => { |
679 | self.expected_tokens.push(TokenType::Token(expected)); | |
680 | false | |
94b46f34 | 681 | } |
94b46f34 XL |
682 | } |
683 | } | |
684 | ||
74b04a01 XL |
685 | /// Eats `+` possibly breaking tokens like `+=` in process. |
686 | fn eat_plus(&mut self) -> bool { | |
687 | self.break_and_eat(token::BinOp(token::Plus)) | |
688 | } | |
689 | ||
690 | /// Eats `&` possibly breaking tokens like `&&` in process. | |
691 | /// Signals an error if `&` is not eaten. | |
9cc50fc6 | 692 | fn expect_and(&mut self) -> PResult<'a, ()> { |
74b04a01 | 693 | if self.break_and_eat(token::BinOp(token::And)) { Ok(()) } else { self.unexpected() } |
ea8adc8c XL |
694 | } |
695 | ||
74b04a01 XL |
696 | /// Eats `|` possibly breaking tokens like `||` in process. |
697 | /// Signals an error if `|` was not eaten. | |
ea8adc8c | 698 | fn expect_or(&mut self) -> PResult<'a, ()> { |
74b04a01 | 699 | if self.break_and_eat(token::BinOp(token::Or)) { Ok(()) } else { self.unexpected() } |
970d7e83 LB |
700 | } |
701 | ||
74b04a01 | 702 | /// Eats `<` possibly breaking tokens like `<<` in process. |
9cc50fc6 | 703 | fn eat_lt(&mut self) -> bool { |
74b04a01 | 704 | let ate = self.break_and_eat(token::Lt); |
9fa01778 XL |
705 | if ate { |
706 | // See doc comment for `unmatched_angle_bracket_count`. | |
707 | self.unmatched_angle_bracket_count += 1; | |
708 | self.max_angle_bracket_count += 1; | |
709 | debug!("eat_lt: (increment) count={:?}", self.unmatched_angle_bracket_count); | |
1a4d82fc | 710 | } |
9fa01778 | 711 | ate |
1a4d82fc JJ |
712 | } |
713 | ||
74b04a01 XL |
714 | /// Eats `<` possibly breaking tokens like `<<` in process. |
715 | /// Signals an error if `<` was not eaten. | |
9cc50fc6 | 716 | fn expect_lt(&mut self) -> PResult<'a, ()> { |
74b04a01 | 717 | if self.eat_lt() { Ok(()) } else { self.unexpected() } |
1a4d82fc JJ |
718 | } |
719 | ||
74b04a01 XL |
720 | /// Eats `>` possibly breaking tokens like `>>` in process. |
721 | /// Signals an error if `>` was not eaten. | |
94b46f34 | 722 | fn expect_gt(&mut self) -> PResult<'a, ()> { |
74b04a01 XL |
723 | if self.break_and_eat(token::Gt) { |
724 | // See doc comment for `unmatched_angle_bracket_count`. | |
725 | if self.unmatched_angle_bracket_count > 0 { | |
726 | self.unmatched_angle_bracket_count -= 1; | |
727 | debug!("expect_gt: (decrement) count={:?}", self.unmatched_angle_bracket_count); | |
dfeec247 | 728 | } |
74b04a01 XL |
729 | Ok(()) |
730 | } else { | |
731 | self.unexpected() | |
1a4d82fc JJ |
732 | } |
733 | } | |
734 | ||
416331ca | 735 | fn expect_any_with_type(&mut self, kets: &[&TokenKind], expect: TokenExpectType) -> bool { |
dfeec247 XL |
736 | kets.iter().any(|k| match expect { |
737 | TokenExpectType::Expect => self.check(k), | |
738 | TokenExpectType::NoExpect => self.token == **k, | |
416331ca XL |
739 | }) |
740 | } | |
741 | ||
e74abb32 | 742 | fn parse_seq_to_before_tokens<T>( |
b7449926 | 743 | &mut self, |
dc9dc135 | 744 | kets: &[&TokenKind], |
b7449926 XL |
745 | sep: SeqSep, |
746 | expect: TokenExpectType, | |
416331ca XL |
747 | mut f: impl FnMut(&mut Parser<'a>) -> PResult<'a, T>, |
748 | ) -> PResult<'a, (Vec<T>, bool /* trailing */, bool /* recovered */)> { | |
9fa01778 XL |
749 | let mut first = true; |
750 | let mut recovered = false; | |
416331ca | 751 | let mut trailing = false; |
c30ab7b3 | 752 | let mut v = vec![]; |
cdc7bbd5 XL |
753 | let unclosed_delims = !self.unclosed_delims.is_empty(); |
754 | ||
416331ca XL |
755 | while !self.expect_any_with_type(kets, expect) { |
756 | if let token::CloseDelim(..) | token::Eof = self.token.kind { | |
dfeec247 | 757 | break; |
416331ca | 758 | } |
7cac9316 XL |
759 | if let Some(ref t) = sep.sep { |
760 | if first { | |
761 | first = false; | |
762 | } else { | |
9fa01778 XL |
763 | match self.expect(t) { |
764 | Ok(false) => {} | |
765 | Ok(true) => { | |
766 | recovered = true; | |
767 | break; | |
abe05a73 | 768 | } |
60c5eb7d | 769 | Err(mut expect_err) => { |
74b04a01 | 770 | let sp = self.prev_token.span.shrink_to_hi(); |
60c5eb7d XL |
771 | let token_str = pprust::token_kind_to_string(t); |
772 | ||
e1599b0c | 773 | // Attempt to keep parsing if it was a similar separator. |
9fa01778 | 774 | if let Some(ref tokens) = t.similar_tokens() { |
cdc7bbd5 | 775 | if tokens.contains(&self.token.kind) && !unclosed_delims { |
9fa01778 XL |
776 | self.bump(); |
777 | } | |
778 | } | |
60c5eb7d | 779 | |
f9f354fc XL |
780 | // If this was a missing `@` in a binding pattern |
781 | // bail with a suggestion | |
782 | // https://github.com/rust-lang/rust/issues/72373 | |
f035d41b | 783 | if self.prev_token.is_ident() && self.token.kind == token::DotDot { |
f9f354fc XL |
784 | let msg = format!( |
785 | "if you meant to bind the contents of \ | |
786 | the rest of the array pattern into `{}`, use `@`", | |
787 | pprust::token_to_string(&self.prev_token) | |
788 | ); | |
789 | expect_err | |
790 | .span_suggestion_verbose( | |
791 | self.prev_token.span.shrink_to_hi().until(self.token.span), | |
792 | &msg, | |
793 | " @ ".to_string(), | |
794 | Applicability::MaybeIncorrect, | |
795 | ) | |
796 | .emit(); | |
797 | break; | |
798 | } | |
799 | ||
e1599b0c | 800 | // Attempt to keep parsing if it was an omitted separator. |
9fa01778 XL |
801 | match f(self) { |
802 | Ok(t) => { | |
60c5eb7d XL |
803 | // Parsed successfully, therefore most probably the code only |
804 | // misses a separator. | |
805 | expect_err | |
806 | .span_suggestion_short( | |
5869c6ff | 807 | sp, |
60c5eb7d XL |
808 | &format!("missing `{}`", token_str), |
809 | token_str, | |
810 | Applicability::MaybeIncorrect, | |
811 | ) | |
812 | .emit(); | |
813 | ||
9fa01778 XL |
814 | v.push(t); |
815 | continue; | |
dfeec247 | 816 | } |
9fa01778 | 817 | Err(mut e) => { |
60c5eb7d XL |
818 | // Parsing failed, therefore it must be something more serious |
819 | // than just a missing separator. | |
820 | expect_err.emit(); | |
821 | ||
9fa01778 XL |
822 | e.cancel(); |
823 | break; | |
824 | } | |
abe05a73 XL |
825 | } |
826 | } | |
7453a54e SL |
827 | } |
828 | } | |
7453a54e | 829 | } |
416331ca XL |
830 | if sep.trailing_sep_allowed && self.expect_any_with_type(kets, expect) { |
831 | trailing = true; | |
7453a54e SL |
832 | break; |
833 | } | |
834 | ||
abe05a73 XL |
835 | let t = f(self)?; |
836 | v.push(t); | |
970d7e83 | 837 | } |
7453a54e | 838 | |
416331ca | 839 | Ok((v, trailing, recovered)) |
970d7e83 LB |
840 | } |
841 | ||
dfeec247 XL |
842 | /// Parses a sequence, not including the closing delimiter. The function |
843 | /// `f` must consume tokens until reaching the next separator or | |
844 | /// closing bracket. | |
845 | fn parse_seq_to_before_end<T>( | |
846 | &mut self, | |
847 | ket: &TokenKind, | |
848 | sep: SeqSep, | |
849 | f: impl FnMut(&mut Parser<'a>) -> PResult<'a, T>, | |
850 | ) -> PResult<'a, (Vec<T>, bool, bool)> { | |
851 | self.parse_seq_to_before_tokens(&[ket], sep, TokenExpectType::Expect, f) | |
852 | } | |
853 | ||
854 | /// Parses a sequence, including the closing delimiter. The function | |
855 | /// `f` must consume tokens until reaching the next separator or | |
856 | /// closing bracket. | |
857 | fn parse_seq_to_end<T>( | |
858 | &mut self, | |
859 | ket: &TokenKind, | |
860 | sep: SeqSep, | |
861 | f: impl FnMut(&mut Parser<'a>) -> PResult<'a, T>, | |
862 | ) -> PResult<'a, (Vec<T>, bool /* trailing */)> { | |
863 | let (val, trailing, recovered) = self.parse_seq_to_before_end(ket, sep, f)?; | |
864 | if !recovered { | |
865 | self.eat(ket); | |
866 | } | |
867 | Ok((val, trailing)) | |
868 | } | |
869 | ||
9fa01778 XL |
870 | /// Parses a sequence, including the closing delimiter. The function |
871 | /// `f` must consume tokens until reaching the next separator or | |
1a4d82fc | 872 | /// closing bracket. |
416331ca | 873 | fn parse_unspanned_seq<T>( |
9fa01778 | 874 | &mut self, |
dc9dc135 XL |
875 | bra: &TokenKind, |
876 | ket: &TokenKind, | |
9fa01778 | 877 | sep: SeqSep, |
416331ca XL |
878 | f: impl FnMut(&mut Parser<'a>) -> PResult<'a, T>, |
879 | ) -> PResult<'a, (Vec<T>, bool)> { | |
54a0048b | 880 | self.expect(bra)?; |
dfeec247 | 881 | self.parse_seq_to_end(ket, sep, f) |
416331ca XL |
882 | } |
883 | ||
884 | fn parse_delim_comma_seq<T>( | |
885 | &mut self, | |
886 | delim: DelimToken, | |
887 | f: impl FnMut(&mut Parser<'a>) -> PResult<'a, T>, | |
888 | ) -> PResult<'a, (Vec<T>, bool)> { | |
889 | self.parse_unspanned_seq( | |
890 | &token::OpenDelim(delim), | |
891 | &token::CloseDelim(delim), | |
892 | SeqSep::trailing_allowed(token::Comma), | |
893 | f, | |
894 | ) | |
895 | } | |
896 | ||
897 | fn parse_paren_comma_seq<T>( | |
898 | &mut self, | |
899 | f: impl FnMut(&mut Parser<'a>) -> PResult<'a, T>, | |
900 | ) -> PResult<'a, (Vec<T>, bool)> { | |
901 | self.parse_delim_comma_seq(token::Paren, f) | |
970d7e83 LB |
902 | } |
903 | ||
74b04a01 | 904 | /// Advance the parser by one token using provided token as the next one. |
29967ef6 | 905 | fn bump_with(&mut self, (next_token, next_spacing): (Token, Spacing)) { |
74b04a01 XL |
906 | // Bumping after EOF is a bad sign, usually an infinite loop. |
907 | if self.prev_token.kind == TokenKind::Eof { | |
dfeec247 XL |
908 | let msg = "attempted to bump the parser past EOF (may be stuck in a loop)"; |
909 | self.span_bug(self.token.span, msg); | |
7453a54e SL |
910 | } |
911 | ||
74b04a01 XL |
912 | // Update the current and previous tokens. |
913 | self.prev_token = mem::replace(&mut self.token, next_token); | |
29967ef6 | 914 | self.token_spacing = next_spacing; |
9e0c209e | 915 | |
74b04a01 | 916 | // Diagnostics. |
7453a54e | 917 | self.expected_tokens.clear(); |
223e47cc | 918 | } |
7453a54e | 919 | |
74b04a01 XL |
920 | /// Advance the parser by one token. |
921 | pub fn bump(&mut self) { | |
922 | let next_token = self.next_tok(self.token.span); | |
923 | self.bump_with(next_token); | |
924 | } | |
925 | ||
e74abb32 XL |
926 | /// Look-ahead `dist` tokens of `self.token` and get access to that token there. |
927 | /// When `dist == 0` then the current token is looked at. | |
928 | pub fn look_ahead<R>(&self, dist: usize, looker: impl FnOnce(&Token) -> R) -> R { | |
c30ab7b3 | 929 | if dist == 0 { |
e74abb32 | 930 | return looker(&self.token); |
223e47cc | 931 | } |
8bb4bdeb | 932 | |
dc9dc135 | 933 | let frame = &self.token_cursor.frame; |
cdc7bbd5 XL |
934 | if frame.delim != DelimToken::NoDelim { |
935 | let all_normal = (0..dist).all(|i| { | |
936 | let token = frame.tree_cursor.look_ahead(i); | |
937 | !matches!(token, Some(TokenTree::Delimited(_, DelimToken::NoDelim, _))) | |
938 | }); | |
939 | if all_normal { | |
940 | return match frame.tree_cursor.look_ahead(dist - 1) { | |
941 | Some(tree) => match tree { | |
942 | TokenTree::Token(token) => looker(token), | |
943 | TokenTree::Delimited(dspan, delim, _) => { | |
944 | looker(&Token::new(token::OpenDelim(*delim), dspan.open)) | |
945 | } | |
946 | }, | |
947 | None => looker(&Token::new(token::CloseDelim(frame.delim), frame.span.close)), | |
948 | }; | |
949 | } | |
29967ef6 | 950 | } |
cdc7bbd5 XL |
951 | |
952 | let mut cursor = self.token_cursor.clone(); | |
953 | let mut i = 0; | |
954 | let mut token = Token::dummy(); | |
955 | while i < dist { | |
956 | token = cursor.next().0; | |
957 | if matches!( | |
958 | token.kind, | |
959 | token::OpenDelim(token::NoDelim) | token::CloseDelim(token::NoDelim) | |
960 | ) { | |
961 | continue; | |
962 | } | |
963 | i += 1; | |
964 | } | |
965 | return looker(&token); | |
223e47cc | 966 | } |
ff7c6d11 | 967 | |
dc9dc135 XL |
968 | /// Returns whether any of the given keywords are `dist` tokens ahead of the current one. |
969 | fn is_keyword_ahead(&self, dist: usize, kws: &[Symbol]) -> bool { | |
970 | self.look_ahead(dist, |t| kws.iter().any(|&kw| t.is_keyword(kw))) | |
223e47cc | 971 | } |
223e47cc | 972 | |
9fa01778 | 973 | /// Parses asyncness: `async` or nothing. |
74b04a01 | 974 | fn parse_asyncness(&mut self) -> Async { |
dc9dc135 | 975 | if self.eat_keyword(kw::Async) { |
74b04a01 XL |
976 | let span = self.prev_token.uninterpolated_span(); |
977 | Async::Yes { span, closure_id: DUMMY_NODE_ID, return_impl_trait_id: DUMMY_NODE_ID } | |
8faf50e0 | 978 | } else { |
74b04a01 | 979 | Async::No |
8faf50e0 XL |
980 | } |
981 | } | |
982 | ||
9fa01778 | 983 | /// Parses unsafety: `unsafe` or nothing. |
74b04a01 XL |
984 | fn parse_unsafety(&mut self) -> Unsafe { |
985 | if self.eat_keyword(kw::Unsafe) { | |
986 | Unsafe::Yes(self.prev_token.uninterpolated_span()) | |
987 | } else { | |
988 | Unsafe::No | |
989 | } | |
990 | } | |
991 | ||
992 | /// Parses constness: `const` or nothing. | |
993 | fn parse_constness(&mut self) -> Const { | |
29967ef6 XL |
994 | // Avoid const blocks to be parsed as const items |
995 | if self.look_ahead(1, |t| t != &token::OpenDelim(DelimToken::Brace)) | |
996 | && self.eat_keyword(kw::Const) | |
997 | { | |
74b04a01 XL |
998 | Const::Yes(self.prev_token.uninterpolated_span()) |
999 | } else { | |
1000 | Const::No | |
1001 | } | |
1a4d82fc JJ |
1002 | } |
1003 | ||
29967ef6 XL |
1004 | /// Parses inline const expressions. |
1005 | fn parse_const_block(&mut self, span: Span) -> PResult<'a, P<Expr>> { | |
1006 | self.sess.gated_spans.gate(sym::inline_const, span); | |
1007 | self.eat_keyword(kw::Const); | |
1008 | let blk = self.parse_block()?; | |
1009 | let anon_const = AnonConst { | |
1010 | id: DUMMY_NODE_ID, | |
1011 | value: self.mk_expr(blk.span, ExprKind::Block(blk, None), AttrVec::new()), | |
1012 | }; | |
fc512014 XL |
1013 | let blk_span = anon_const.value.span; |
1014 | Ok(self.mk_expr(span.to(blk_span), ExprKind::ConstBlock(anon_const), AttrVec::new())) | |
29967ef6 XL |
1015 | } |
1016 | ||
416331ca XL |
1017 | /// Parses mutability (`mut` or nothing). |
1018 | fn parse_mutability(&mut self) -> Mutability { | |
dfeec247 | 1019 | if self.eat_keyword(kw::Mut) { Mutability::Mut } else { Mutability::Not } |
223e47cc LB |
1020 | } |
1021 | ||
e74abb32 XL |
1022 | /// Possibly parses mutability (`const` or `mut`). |
1023 | fn parse_const_or_mut(&mut self) -> Option<Mutability> { | |
1024 | if self.eat_keyword(kw::Mut) { | |
dfeec247 | 1025 | Some(Mutability::Mut) |
e74abb32 | 1026 | } else if self.eat_keyword(kw::Const) { |
dfeec247 | 1027 | Some(Mutability::Not) |
e74abb32 XL |
1028 | } else { |
1029 | None | |
1030 | } | |
1031 | } | |
1032 | ||
416331ca | 1033 | fn parse_field_name(&mut self) -> PResult<'a, Ident> { |
dfeec247 XL |
1034 | if let token::Literal(token::Lit { kind: token::Integer, symbol, suffix }) = self.token.kind |
1035 | { | |
416331ca XL |
1036 | self.expect_no_suffix(self.token.span, "a tuple index", suffix); |
1037 | self.bump(); | |
74b04a01 | 1038 | Ok(Ident::new(symbol, self.prev_token.span)) |
223e47cc | 1039 | } else { |
6a06907d | 1040 | self.parse_ident_common(true) |
223e47cc LB |
1041 | } |
1042 | } | |
1043 | ||
60c5eb7d XL |
1044 | fn parse_mac_args(&mut self) -> PResult<'a, P<MacArgs>> { |
1045 | self.parse_mac_args_common(true).map(P) | |
1046 | } | |
1047 | ||
1048 | fn parse_attr_args(&mut self) -> PResult<'a, MacArgs> { | |
1049 | self.parse_mac_args_common(false) | |
1050 | } | |
1051 | ||
1052 | fn parse_mac_args_common(&mut self, delimited_only: bool) -> PResult<'a, MacArgs> { | |
dfeec247 XL |
1053 | Ok( |
1054 | if self.check(&token::OpenDelim(DelimToken::Paren)) | |
1055 | || self.check(&token::OpenDelim(DelimToken::Bracket)) | |
1056 | || self.check(&token::OpenDelim(DelimToken::Brace)) | |
1057 | { | |
1058 | match self.parse_token_tree() { | |
1059 | TokenTree::Delimited(dspan, delim, tokens) => | |
60c5eb7d | 1060 | // We've confirmed above that there is a delimiter so unwrapping is OK. |
dfeec247 XL |
1061 | { |
1062 | MacArgs::Delimited(dspan, MacDelimiter::from_token(delim).unwrap(), tokens) | |
60c5eb7d | 1063 | } |
dfeec247 | 1064 | _ => unreachable!(), |
60c5eb7d | 1065 | } |
dfeec247 XL |
1066 | } else if !delimited_only { |
1067 | if self.eat(&token::Eq) { | |
74b04a01 | 1068 | let eq_span = self.prev_token.span; |
60c5eb7d | 1069 | |
5869c6ff | 1070 | // Collect tokens because they are used during lowering to HIR. |
cdc7bbd5 | 1071 | let expr = self.parse_expr_force_collect()?; |
fc512014 XL |
1072 | let span = expr.span; |
1073 | ||
5869c6ff XL |
1074 | let token_kind = token::Interpolated(Lrc::new(token::NtExpr(expr))); |
1075 | MacArgs::Eq(eq_span, Token::new(token_kind, span)) | |
dfeec247 XL |
1076 | } else { |
1077 | MacArgs::Empty | |
1078 | } | |
60c5eb7d | 1079 | } else { |
dfeec247 XL |
1080 | return self.unexpected(); |
1081 | }, | |
1082 | ) | |
416331ca | 1083 | } |
041b39d2 | 1084 | |
e74abb32 XL |
1085 | fn parse_or_use_outer_attributes( |
1086 | &mut self, | |
6a06907d XL |
1087 | already_parsed_attrs: Option<AttrWrapper>, |
1088 | ) -> PResult<'a, AttrWrapper> { | |
416331ca XL |
1089 | if let Some(attrs) = already_parsed_attrs { |
1090 | Ok(attrs) | |
970d7e83 | 1091 | } else { |
6a06907d | 1092 | self.parse_outer_attributes() |
970d7e83 LB |
1093 | } |
1094 | } | |
1095 | ||
416331ca | 1096 | /// Parses a single token tree from the input. |
3dfed10e | 1097 | pub(crate) fn parse_token_tree(&mut self) -> TokenTree { |
dc9dc135 | 1098 | match self.token.kind { |
416331ca | 1099 | token::OpenDelim(..) => { |
29967ef6 XL |
1100 | let depth = self.token_cursor.stack.len(); |
1101 | ||
1102 | // We keep advancing the token cursor until we hit | |
1103 | // the matching `CloseDelim` token. | |
1104 | while !(depth == self.token_cursor.stack.len() | |
1105 | && matches!(self.token.kind, token::CloseDelim(_))) | |
1106 | { | |
1107 | // Advance one token at a time, so `TokenCursor::next()` | |
1108 | // can capture these tokens if necessary. | |
1109 | self.bump(); | |
1110 | } | |
1111 | // We are still inside the frame corresponding | |
1112 | // to the delimited stream we captured, so grab | |
1113 | // the tokens from this frame. | |
1114 | let frame = &self.token_cursor.frame; | |
1115 | let stream = frame.tree_cursor.stream.clone(); | |
1116 | let span = frame.span; | |
1117 | let delim = frame.delim; | |
1118 | // Consume close delimiter | |
0731742a | 1119 | self.bump(); |
29967ef6 | 1120 | TokenTree::Delimited(span, delim, stream) |
dfeec247 | 1121 | } |
416331ca XL |
1122 | token::CloseDelim(_) | token::Eof => unreachable!(), |
1123 | _ => { | |
416331ca | 1124 | self.bump(); |
74b04a01 | 1125 | TokenTree::Token(self.prev_token.clone()) |
0731742a | 1126 | } |
0731742a XL |
1127 | } |
1128 | } | |
1129 | ||
416331ca XL |
1130 | /// Parses a stream of tokens into a list of `TokenTree`s, up to EOF. |
1131 | pub fn parse_all_token_trees(&mut self) -> PResult<'a, Vec<TokenTree>> { | |
1132 | let mut tts = Vec::new(); | |
1133 | while self.token != token::Eof { | |
1134 | tts.push(self.parse_token_tree()); | |
54a0048b | 1135 | } |
416331ca | 1136 | Ok(tts) |
54a0048b SL |
1137 | } |
1138 | ||
416331ca XL |
1139 | pub fn parse_tokens(&mut self) -> TokenStream { |
1140 | let mut result = Vec::new(); | |
1141 | loop { | |
1142 | match self.token.kind { | |
1143 | token::Eof | token::CloseDelim(..) => break, | |
1144 | _ => result.push(self.parse_token_tree().into()), | |
ff7c6d11 | 1145 | } |
223e47cc | 1146 | } |
416331ca | 1147 | TokenStream::new(result) |
223e47cc LB |
1148 | } |
1149 | ||
416331ca XL |
1150 | /// Evaluates the closure with restrictions in place. |
1151 | /// | |
1152 | /// Afters the closure is evaluated, restrictions are reset. | |
e74abb32 | 1153 | fn with_res<T>(&mut self, res: Restrictions, f: impl FnOnce(&mut Self) -> T) -> T { |
416331ca | 1154 | let old = self.restrictions; |
e74abb32 XL |
1155 | self.restrictions = res; |
1156 | let res = f(self); | |
416331ca | 1157 | self.restrictions = old; |
e74abb32 | 1158 | res |
8faf50e0 XL |
1159 | } |
1160 | ||
416331ca XL |
1161 | fn is_crate_vis(&self) -> bool { |
1162 | self.token.is_keyword(kw::Crate) && self.look_ahead(1, |t| t != &token::ModSep) | |
223e47cc LB |
1163 | } |
1164 | ||
416331ca XL |
1165 | /// Parses `pub`, `pub(crate)` and `pub(in path)` plus shortcuts `crate` for `pub(crate)`, |
1166 | /// `pub(self)` for `pub(in self)` and `pub(super)` for `pub(in super)`. | |
1167 | /// If the following element can't be a tuple (i.e., it's a function definition), then | |
1168 | /// it's not a tuple struct field), and the contents within the parentheses isn't valid, | |
1169 | /// so emit a proper diagnostic. | |
1b1a35ee XL |
1170 | // Public for rustfmt usage. |
1171 | pub fn parse_visibility(&mut self, fbt: FollowedByType) -> PResult<'a, Visibility> { | |
416331ca | 1172 | maybe_whole!(self, NtVis, |x| x); |
dc9dc135 | 1173 | |
416331ca XL |
1174 | self.expected_tokens.push(TokenType::Keyword(kw::Crate)); |
1175 | if self.is_crate_vis() { | |
1176 | self.bump(); // `crate` | |
74b04a01 | 1177 | self.sess.gated_spans.gate(sym::crate_visibility_modifier, self.prev_token.span); |
1b1a35ee XL |
1178 | return Ok(Visibility { |
1179 | span: self.prev_token.span, | |
1180 | kind: VisibilityKind::Crate(CrateSugar::JustCrate), | |
1181 | tokens: None, | |
1182 | }); | |
416331ca | 1183 | } |
223e47cc | 1184 | |
416331ca XL |
1185 | if !self.eat_keyword(kw::Pub) { |
1186 | // We need a span for our `Spanned<VisibilityKind>`, but there's inherently no | |
1187 | // keyword to grab a span from for inherited visibility; an empty span at the | |
1188 | // beginning of the current token would seem to be the "Schelling span". | |
1b1a35ee XL |
1189 | return Ok(Visibility { |
1190 | span: self.token.span.shrink_to_lo(), | |
1191 | kind: VisibilityKind::Inherited, | |
1192 | tokens: None, | |
1193 | }); | |
416331ca | 1194 | } |
74b04a01 | 1195 | let lo = self.prev_token.span; |
223e47cc | 1196 | |
416331ca XL |
1197 | if self.check(&token::OpenDelim(token::Paren)) { |
1198 | // We don't `self.bump()` the `(` yet because this might be a struct definition where | |
1199 | // `()` or a tuple might be allowed. For example, `struct Struct(pub (), pub (usize));`. | |
1200 | // Because of this, we only `bump` the `(` if we're assured it is appropriate to do so | |
1201 | // by the following tokens. | |
dfeec247 XL |
1202 | if self.is_keyword_ahead(1, &[kw::Crate]) && self.look_ahead(2, |t| t != &token::ModSep) |
1203 | // account for `pub(crate::foo)` | |
416331ca | 1204 | { |
e74abb32 | 1205 | // Parse `pub(crate)`. |
416331ca XL |
1206 | self.bump(); // `(` |
1207 | self.bump(); // `crate` | |
1208 | self.expect(&token::CloseDelim(token::Paren))?; // `)` | |
e74abb32 | 1209 | let vis = VisibilityKind::Crate(CrateSugar::PubCrate); |
1b1a35ee XL |
1210 | return Ok(Visibility { |
1211 | span: lo.to(self.prev_token.span), | |
1212 | kind: vis, | |
1213 | tokens: None, | |
1214 | }); | |
416331ca | 1215 | } else if self.is_keyword_ahead(1, &[kw::In]) { |
e74abb32 | 1216 | // Parse `pub(in path)`. |
416331ca XL |
1217 | self.bump(); // `(` |
1218 | self.bump(); // `in` | |
1219 | let path = self.parse_path(PathStyle::Mod)?; // `path` | |
1220 | self.expect(&token::CloseDelim(token::Paren))?; // `)` | |
dfeec247 | 1221 | let vis = VisibilityKind::Restricted { path: P(path), id: ast::DUMMY_NODE_ID }; |
1b1a35ee XL |
1222 | return Ok(Visibility { |
1223 | span: lo.to(self.prev_token.span), | |
1224 | kind: vis, | |
1225 | tokens: None, | |
1226 | }); | |
e74abb32 XL |
1227 | } else if self.look_ahead(2, |t| t == &token::CloseDelim(token::Paren)) |
1228 | && self.is_keyword_ahead(1, &[kw::Super, kw::SelfLower]) | |
416331ca | 1229 | { |
e74abb32 | 1230 | // Parse `pub(self)` or `pub(super)`. |
416331ca XL |
1231 | self.bump(); // `(` |
1232 | let path = self.parse_path(PathStyle::Mod)?; // `super`/`self` | |
1233 | self.expect(&token::CloseDelim(token::Paren))?; // `)` | |
dfeec247 | 1234 | let vis = VisibilityKind::Restricted { path: P(path), id: ast::DUMMY_NODE_ID }; |
1b1a35ee XL |
1235 | return Ok(Visibility { |
1236 | span: lo.to(self.prev_token.span), | |
1237 | kind: vis, | |
1238 | tokens: None, | |
1239 | }); | |
60c5eb7d XL |
1240 | } else if let FollowedByType::No = fbt { |
1241 | // Provide this diagnostic if a type cannot follow; | |
1242 | // in particular, if this is not a tuple struct. | |
e74abb32 XL |
1243 | self.recover_incorrect_vis_restriction()?; |
1244 | // Emit diagnostic, but continue with public visibility. | |
532ac7d7 | 1245 | } |
223e47cc | 1246 | } |
223e47cc | 1247 | |
1b1a35ee | 1248 | Ok(Visibility { span: lo, kind: VisibilityKind::Public, tokens: None }) |
223e47cc LB |
1249 | } |
1250 | ||
e74abb32 XL |
1251 | /// Recovery for e.g. `pub(something) fn ...` or `struct X { pub(something) y: Z }` |
1252 | fn recover_incorrect_vis_restriction(&mut self) -> PResult<'a, ()> { | |
1253 | self.bump(); // `(` | |
1254 | let path = self.parse_path(PathStyle::Mod)?; | |
dfeec247 | 1255 | self.expect(&token::CloseDelim(token::Paren))?; // `)` |
e74abb32 XL |
1256 | |
1257 | let msg = "incorrect visibility restriction"; | |
1258 | let suggestion = r##"some possible visibility restrictions are: | |
1259 | `pub(crate)`: visible only on the current crate | |
1260 | `pub(super)`: visible only in the current module's parent | |
1261 | `pub(in path::to::module)`: visible only on the specified path"##; | |
1262 | ||
1263 | let path_str = pprust::path_to_string(&path); | |
1264 | ||
1265 | struct_span_err!(self.sess.span_diagnostic, path.span, E0704, "{}", msg) | |
1266 | .help(suggestion) | |
1267 | .span_suggestion( | |
1268 | path.span, | |
1269 | &format!("make this visible only to module `{}` with `in`", path_str), | |
1270 | format!("in {}", path_str), | |
1271 | Applicability::MachineApplicable, | |
1272 | ) | |
1273 | .emit(); | |
1274 | ||
1275 | Ok(()) | |
1276 | } | |
1277 | ||
60c5eb7d | 1278 | /// Parses `extern string_literal?`. |
6a06907d XL |
1279 | fn parse_extern(&mut self) -> Extern { |
1280 | if self.eat_keyword(kw::Extern) { Extern::from_abi(self.parse_abi()) } else { Extern::None } | |
e74abb32 XL |
1281 | } |
1282 | ||
60c5eb7d XL |
1283 | /// Parses a string literal as an ABI spec. |
1284 | fn parse_abi(&mut self) -> Option<StrLit> { | |
1285 | match self.parse_str_lit() { | |
1286 | Ok(str_lit) => Some(str_lit), | |
1287 | Err(Some(lit)) => match lit.kind { | |
1288 | ast::LitKind::Err(_) => None, | |
1289 | _ => { | |
1290 | self.struct_span_err(lit.span, "non-string ABI literal") | |
1291 | .span_suggestion( | |
1292 | lit.span, | |
1293 | "specify the ABI with a string literal", | |
1294 | "\"C\"".to_string(), | |
1295 | Applicability::MaybeIncorrect, | |
1296 | ) | |
1297 | .emit(); | |
1298 | None | |
223e47cc | 1299 | } |
dfeec247 | 1300 | }, |
60c5eb7d | 1301 | Err(None) => None, |
223e47cc LB |
1302 | } |
1303 | } | |
1304 | ||
6a06907d | 1305 | pub fn collect_tokens_no_attrs<R: AstLike>( |
5869c6ff XL |
1306 | &mut self, |
1307 | f: impl FnOnce(&mut Self) -> PResult<'a, R>, | |
1308 | ) -> PResult<'a, R> { | |
6a06907d XL |
1309 | // The only reason to call `collect_tokens_no_attrs` is if you want tokens, so use |
1310 | // `ForceCollect::Yes` | |
1311 | self.collect_tokens_trailing_token( | |
1312 | AttrWrapper::empty(), | |
1313 | ForceCollect::Yes, | |
1314 | |this, _attrs| Ok((f(this)?, TrailingToken::None)), | |
1315 | ) | |
3b2f2976 XL |
1316 | } |
1317 | ||
0531ce1d XL |
1318 | /// `::{` or `::*` |
1319 | fn is_import_coupler(&mut self) -> bool { | |
dfeec247 XL |
1320 | self.check(&token::ModSep) |
1321 | && self.look_ahead(1, |t| { | |
1322 | *t == token::OpenDelim(token::Brace) || *t == token::BinOp(token::Star) | |
1323 | }) | |
a7813a04 | 1324 | } |
1b1a35ee XL |
1325 | |
1326 | pub fn clear_expected_tokens(&mut self) { | |
1327 | self.expected_tokens.clear(); | |
1328 | } | |
e74abb32 | 1329 | } |
532ac7d7 | 1330 | |
e74abb32 XL |
1331 | crate fn make_unclosed_delims_error( |
1332 | unmatched: UnmatchedBrace, | |
1333 | sess: &ParseSess, | |
1334 | ) -> Option<DiagnosticBuilder<'_>> { | |
1335 | // `None` here means an `Eof` was found. We already emit those errors elsewhere, we add them to | |
1336 | // `unmatched_braces` only for error recovery in the `Parser`. | |
1337 | let found_delim = unmatched.found_delim?; | |
dfeec247 XL |
1338 | let mut err = sess.span_diagnostic.struct_span_err( |
1339 | unmatched.found_span, | |
1340 | &format!( | |
1341 | "mismatched closing delimiter: `{}`", | |
1342 | pprust::token_kind_to_string(&token::CloseDelim(found_delim)), | |
1343 | ), | |
1344 | ); | |
1345 | err.span_label(unmatched.found_span, "mismatched closing delimiter"); | |
e74abb32 | 1346 | if let Some(sp) = unmatched.candidate_span { |
dfeec247 | 1347 | err.span_label(sp, "closing delimiter possibly meant for this"); |
e74abb32 XL |
1348 | } |
1349 | if let Some(sp) = unmatched.unclosed_span { | |
dfeec247 | 1350 | err.span_label(sp, "unclosed delimiter"); |
e74abb32 XL |
1351 | } |
1352 | Some(err) | |
223e47cc | 1353 | } |
9fa01778 | 1354 | |
e74abb32 | 1355 | pub fn emit_unclosed_delims(unclosed_delims: &mut Vec<UnmatchedBrace>, sess: &ParseSess) { |
dfeec247 XL |
1356 | *sess.reached_eof.borrow_mut() |= |
1357 | unclosed_delims.iter().any(|unmatched_delim| unmatched_delim.found_delim.is_none()); | |
e74abb32 | 1358 | for unmatched in unclosed_delims.drain(..) { |
f9f354fc | 1359 | if let Some(mut e) = make_unclosed_delims_error(unmatched, sess) { |
74b04a01 | 1360 | e.emit(); |
f9f354fc | 1361 | } |
9fa01778 | 1362 | } |
9fa01778 | 1363 | } |
cdc7bbd5 XL |
1364 | |
1365 | /// A helper struct used when building a `AttrAnnotatedTokenStream` from | |
1366 | /// a `LazyTokenStream`. Both delimiter and non-delimited tokens | |
1367 | /// are stored as `FlatToken::Token`. A vector of `FlatToken`s | |
1368 | /// is then 'parsed' to build up a `AttrAnnotatedTokenStream` with nested | |
1369 | /// `AttrAnnotatedTokenTree::Delimited` tokens | |
1370 | #[derive(Debug, Clone)] | |
1371 | pub enum FlatToken { | |
1372 | /// A token - this holds both delimiter (e.g. '{' and '}') | |
1373 | /// and non-delimiter tokens | |
1374 | Token(Token), | |
1375 | /// Holds the `AttributesData` for an AST node. The | |
1376 | /// `AttributesData` is inserted directly into the | |
1377 | /// constructed `AttrAnnotatedTokenStream` as | |
1378 | /// a `AttrAnnotatedTokenTree::Attributes` | |
1379 | AttrTarget(AttributesData), | |
1380 | /// A special 'empty' token that is ignored during the conversion | |
1381 | /// to a `AttrAnnotatedTokenStream`. This is used to simplify the | |
1382 | /// handling of replace ranges. | |
1383 | Empty, | |
1384 | } |