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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; |
6a06907d | 17 | pub use pat::{GateOr, 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}; | |
6a06907d XL |
22 | use rustc_ast::tokenstream::{self, DelimSpan, Spacing}; |
23 | use rustc_ast::tokenstream::{TokenStream, TokenTree, TreeAndSpacing}; | |
3dfed10e | 24 | use rustc_ast::DUMMY_NODE_ID; |
6a06907d | 25 | use rustc_ast::{self as ast, AnonConst, AstLike, AttrStyle, AttrVec, Const, CrateSugar, Extern}; |
5869c6ff | 26 | use rustc_ast::{Async, Expr, ExprKind, MacArgs, MacDelimiter, Mutability, StrLit, Unsafe}; |
29967ef6 | 27 | use rustc_ast::{Visibility, VisibilityKind}; |
74b04a01 | 28 | use rustc_ast_pretty::pprust; |
fc512014 | 29 | use rustc_data_structures::sync::Lrc; |
29967ef6 XL |
30 | use rustc_errors::PResult; |
31 | use rustc_errors::{struct_span_err, Applicability, DiagnosticBuilder, FatalError}; | |
74b04a01 | 32 | use rustc_session::parse::ParseSess; |
1b1a35ee | 33 | use rustc_span::source_map::{Span, DUMMY_SP}; |
f9f354fc | 34 | use rustc_span::symbol::{kw, sym, Ident, Symbol}; |
3dfed10e | 35 | use tracing::debug; |
74b04a01 | 36 | |
dfeec247 | 37 | use std::{cmp, mem, slice}; |
60c5eb7d | 38 | |
9fa01778 | 39 | bitflags::bitflags! { |
94b46f34 | 40 | struct Restrictions: u8 { |
ea8adc8c XL |
41 | const STMT_EXPR = 1 << 0; |
42 | const NO_STRUCT_LITERAL = 1 << 1; | |
29967ef6 | 43 | const CONST_EXPR = 1 << 2; |
1a4d82fc | 44 | } |
223e47cc LB |
45 | } |
46 | ||
8faf50e0 | 47 | #[derive(Clone, Copy, PartialEq, Debug)] |
e74abb32 | 48 | enum SemiColonMode { |
7453a54e SL |
49 | Break, |
50 | Ignore, | |
9fa01778 | 51 | Comma, |
7453a54e SL |
52 | } |
53 | ||
8faf50e0 | 54 | #[derive(Clone, Copy, PartialEq, Debug)] |
e74abb32 | 55 | enum BlockMode { |
cc61c64b XL |
56 | Break, |
57 | Ignore, | |
58 | } | |
59 | ||
5869c6ff XL |
60 | /// Whether or not we should force collection of tokens for an AST node, |
61 | /// regardless of whether or not it has attributes | |
62 | pub enum ForceCollect { | |
63 | Yes, | |
64 | No, | |
65 | } | |
66 | ||
67 | pub enum TrailingToken { | |
68 | None, | |
69 | Semi, | |
6a06907d XL |
70 | /// If the trailing token is a comma, then capture it |
71 | /// Otherwise, ignore the trailing token | |
72 | MaybeComma, | |
5869c6ff XL |
73 | } |
74 | ||
e1599b0c | 75 | /// Like `maybe_whole_expr`, but for things other than expressions. |
416331ca | 76 | #[macro_export] |
1a4d82fc | 77 | macro_rules! maybe_whole { |
c30ab7b3 | 78 | ($p:expr, $constructor:ident, |$x:ident| $e:expr) => { |
dc9dc135 | 79 | if let token::Interpolated(nt) = &$p.token.kind { |
532ac7d7 XL |
80 | if let token::$constructor(x) = &**nt { |
81 | let $x = x.clone(); | |
c30ab7b3 SL |
82 | $p.bump(); |
83 | return Ok($e); | |
223e47cc | 84 | } |
1a4d82fc | 85 | } |
c30ab7b3 | 86 | }; |
1a4d82fc | 87 | } |
223e47cc | 88 | |
532ac7d7 | 89 | /// If the next tokens are ill-formed `$ty::` recover them as `<$ty>::`. |
416331ca | 90 | #[macro_export] |
532ac7d7 XL |
91 | macro_rules! maybe_recover_from_interpolated_ty_qpath { |
92 | ($self: expr, $allow_qpath_recovery: expr) => { | |
93 | if $allow_qpath_recovery && $self.look_ahead(1, |t| t == &token::ModSep) { | |
dc9dc135 | 94 | if let token::Interpolated(nt) = &$self.token.kind { |
532ac7d7 XL |
95 | if let token::NtTy(ty) = &**nt { |
96 | let ty = ty.clone(); | |
97 | $self.bump(); | |
74b04a01 | 98 | return $self.maybe_recover_from_bad_qpath_stage_2($self.prev_token.span, ty); |
532ac7d7 XL |
99 | } |
100 | } | |
101 | } | |
dfeec247 | 102 | }; |
532ac7d7 XL |
103 | } |
104 | ||
041b39d2 | 105 | #[derive(Clone)] |
1a4d82fc JJ |
106 | pub struct Parser<'a> { |
107 | pub sess: &'a ParseSess, | |
74b04a01 | 108 | /// The current token. |
dc9dc135 | 109 | pub token: Token, |
29967ef6 XL |
110 | /// The spacing for the current token |
111 | pub token_spacing: Spacing, | |
74b04a01 XL |
112 | /// The previous token. |
113 | pub prev_token: Token, | |
94b46f34 | 114 | restrictions: Restrictions, |
e74abb32 | 115 | expected_tokens: Vec<TokenType>, |
29967ef6 XL |
116 | // Important: This must only be advanced from `next_tok` |
117 | // to ensure that `token_cursor.num_next_calls` is updated properly | |
e1599b0c | 118 | token_cursor: TokenCursor, |
94b46f34 | 119 | desugar_doc_comments: bool, |
9fa01778 XL |
120 | /// This field is used to keep track of how many left angle brackets we have seen. This is |
121 | /// required in order to detect extra leading left angle brackets (`<` characters) and error | |
122 | /// appropriately. | |
123 | /// | |
124 | /// See the comments in the `parse_path_segment` function for more details. | |
e74abb32 XL |
125 | unmatched_angle_bracket_count: u32, |
126 | max_angle_bracket_count: u32, | |
e1599b0c | 127 | /// A list of all unclosed delimiters found by the lexer. If an entry is used for error recovery |
9fa01778 XL |
128 | /// it gets removed from here. Every entry left at the end gets emitted as an independent |
129 | /// error. | |
e74abb32 XL |
130 | pub(super) unclosed_delims: Vec<UnmatchedBrace>, |
131 | last_unexpected_token_span: Option<Span>, | |
3dfed10e XL |
132 | /// Span pointing at the `:` for the last type ascription the parser has seen, and whether it |
133 | /// looked like it could have been a mistyped path or literal `Option:Some(42)`). | |
e74abb32 | 134 | pub last_type_ascription: Option<(Span, bool /* likely path typo */)>, |
dc9dc135 | 135 | /// If present, this `Parser` is not parsing Rust code but rather a macro call. |
e74abb32 | 136 | subparser_name: Option<&'static str>, |
1a4d82fc JJ |
137 | } |
138 | ||
9fa01778 XL |
139 | impl<'a> Drop for Parser<'a> { |
140 | fn drop(&mut self) { | |
e74abb32 | 141 | emit_unclosed_delims(&mut self.unclosed_delims, &self.sess); |
9fa01778 XL |
142 | } |
143 | } | |
7cac9316 | 144 | |
041b39d2 | 145 | #[derive(Clone)] |
e1599b0c XL |
146 | struct TokenCursor { |
147 | frame: TokenCursorFrame, | |
148 | stack: Vec<TokenCursorFrame>, | |
29967ef6 XL |
149 | desugar_doc_comments: bool, |
150 | // Counts the number of calls to `next` or `next_desugared`, | |
151 | // depending on whether `desugar_doc_comments` is set. | |
152 | num_next_calls: usize, | |
fc512014 XL |
153 | // During parsing, we may sometimes need to 'unglue' a |
154 | // glued token into two component tokens | |
155 | // (e.g. '>>' into '>' and '>), so that the parser | |
156 | // can consume them one at a time. This process | |
157 | // bypasses the normal capturing mechanism | |
158 | // (e.g. `num_next_calls` will not be incremented), | |
159 | // since the 'unglued' tokens due not exist in | |
160 | // the original `TokenStream`. | |
161 | // | |
162 | // If we end up consuming both unglued tokens, | |
163 | // then this is not an issue - we'll end up | |
164 | // capturing the single 'glued' token. | |
165 | // | |
166 | // However, in certain circumstances, we may | |
167 | // want to capture just the first 'unglued' token. | |
168 | // For example, capturing the `Vec<u8>` | |
169 | // in `Option<Vec<u8>>` requires us to unglue | |
170 | // the trailing `>>` token. The `append_unglued_token` | |
171 | // field is used to track this token - it gets | |
172 | // appended to the captured stream when | |
173 | // we evaluate a `LazyTokenStream` | |
174 | append_unglued_token: Option<TreeAndSpacing>, | |
8bb4bdeb XL |
175 | } |
176 | ||
041b39d2 | 177 | #[derive(Clone)] |
e1599b0c XL |
178 | struct TokenCursorFrame { |
179 | delim: token::DelimToken, | |
180 | span: DelimSpan, | |
181 | open_delim: bool, | |
182 | tree_cursor: tokenstream::Cursor, | |
183 | close_delim: bool, | |
3b2f2976 XL |
184 | } |
185 | ||
8bb4bdeb | 186 | impl TokenCursorFrame { |
29967ef6 | 187 | fn new(span: DelimSpan, delim: DelimToken, tts: TokenStream) -> Self { |
8bb4bdeb | 188 | TokenCursorFrame { |
dc9dc135 XL |
189 | delim, |
190 | span, | |
0731742a | 191 | open_delim: delim == token::NoDelim, |
29967ef6 | 192 | tree_cursor: tts.into_trees(), |
0731742a | 193 | close_delim: delim == token::NoDelim, |
8bb4bdeb XL |
194 | } |
195 | } | |
196 | } | |
197 | ||
198 | impl TokenCursor { | |
29967ef6 | 199 | fn next(&mut self) -> (Token, Spacing) { |
8bb4bdeb | 200 | loop { |
29967ef6 | 201 | let (tree, spacing) = if !self.frame.open_delim { |
8bb4bdeb | 202 | self.frame.open_delim = true; |
f9f354fc | 203 | TokenTree::open_tt(self.frame.span, self.frame.delim).into() |
1b1a35ee | 204 | } else if let Some(tree) = self.frame.tree_cursor.next_with_spacing() { |
8bb4bdeb XL |
205 | tree |
206 | } else if !self.frame.close_delim { | |
207 | self.frame.close_delim = true; | |
f9f354fc | 208 | TokenTree::close_tt(self.frame.span, self.frame.delim).into() |
8bb4bdeb XL |
209 | } else if let Some(frame) = self.stack.pop() { |
210 | self.frame = frame; | |
dfeec247 | 211 | continue; |
8bb4bdeb | 212 | } else { |
29967ef6 | 213 | (TokenTree::Token(Token::new(token::Eof, DUMMY_SP)), Spacing::Alone) |
8bb4bdeb XL |
214 | }; |
215 | ||
29967ef6 XL |
216 | match tree { |
217 | TokenTree::Token(token) => { | |
218 | return (token, spacing); | |
f9f354fc | 219 | } |
0731742a | 220 | TokenTree::Delimited(sp, delim, tts) => { |
29967ef6 | 221 | let frame = TokenCursorFrame::new(sp, delim, tts); |
8bb4bdeb XL |
222 | self.stack.push(mem::replace(&mut self.frame, frame)); |
223 | } | |
224 | } | |
225 | } | |
226 | } | |
227 | ||
29967ef6 | 228 | fn next_desugared(&mut self) -> (Token, Spacing) { |
3dfed10e | 229 | let (data, attr_style, sp) = match self.next() { |
29967ef6 | 230 | (Token { kind: token::DocComment(_, attr_style, data), span }, _) => { |
3dfed10e XL |
231 | (data, attr_style, span) |
232 | } | |
7cac9316 | 233 | tok => return tok, |
8bb4bdeb XL |
234 | }; |
235 | ||
8bb4bdeb XL |
236 | // Searches for the occurrences of `"#*` and returns the minimum number of `#`s |
237 | // required to wrap the text. | |
238 | let mut num_of_hashes = 0; | |
239 | let mut count = 0; | |
3dfed10e | 240 | for ch in data.as_str().chars() { |
8bb4bdeb XL |
241 | count = match ch { |
242 | '"' => 1, | |
243 | '#' if count > 0 => count + 1, | |
244 | _ => 0, | |
245 | }; | |
246 | num_of_hashes = cmp::max(num_of_hashes, count); | |
247 | } | |
248 | ||
b7449926 | 249 | let delim_span = DelimSpan::from_single(sp); |
0731742a XL |
250 | let body = TokenTree::Delimited( |
251 | delim_span, | |
252 | token::Bracket, | |
dc9dc135 XL |
253 | [ |
254 | TokenTree::token(token::Ident(sym::doc, false), sp), | |
255 | TokenTree::token(token::Eq, sp), | |
3dfed10e | 256 | TokenTree::token(TokenKind::lit(token::StrRaw(num_of_hashes), data, None), sp), |
0731742a | 257 | ] |
dfeec247 XL |
258 | .iter() |
259 | .cloned() | |
74b04a01 | 260 | .collect::<TokenStream>(), |
0731742a | 261 | ); |
8bb4bdeb | 262 | |
dfeec247 XL |
263 | self.stack.push(mem::replace( |
264 | &mut self.frame, | |
265 | TokenCursorFrame::new( | |
266 | delim_span, | |
267 | token::NoDelim, | |
29967ef6 | 268 | if attr_style == AttrStyle::Inner { |
dfeec247 XL |
269 | [TokenTree::token(token::Pound, sp), TokenTree::token(token::Not, sp), body] |
270 | .iter() | |
271 | .cloned() | |
272 | .collect::<TokenStream>() | |
273 | } else { | |
274 | [TokenTree::token(token::Pound, sp), body] | |
275 | .iter() | |
276 | .cloned() | |
277 | .collect::<TokenStream>() | |
278 | }, | |
279 | ), | |
280 | )); | |
8bb4bdeb XL |
281 | |
282 | self.next() | |
283 | } | |
284 | } | |
285 | ||
5869c6ff | 286 | #[derive(Debug, Clone, PartialEq)] |
e74abb32 | 287 | enum TokenType { |
dc9dc135 XL |
288 | Token(TokenKind), |
289 | Keyword(Symbol), | |
1a4d82fc | 290 | Operator, |
32a655c1 SL |
291 | Lifetime, |
292 | Ident, | |
293 | Path, | |
294 | Type, | |
9fa01778 | 295 | Const, |
1a4d82fc | 296 | } |
223e47cc | 297 | |
1a4d82fc | 298 | impl TokenType { |
e74abb32 | 299 | fn to_string(&self) -> String { |
1a4d82fc | 300 | match *self { |
dc9dc135 XL |
301 | TokenType::Token(ref t) => format!("`{}`", pprust::token_kind_to_string(t)), |
302 | TokenType::Keyword(kw) => format!("`{}`", kw), | |
32a655c1 SL |
303 | TokenType::Operator => "an operator".to_string(), |
304 | TokenType::Lifetime => "lifetime".to_string(), | |
305 | TokenType::Ident => "identifier".to_string(), | |
306 | TokenType::Path => "path".to_string(), | |
307 | TokenType::Type => "type".to_string(), | |
fc512014 | 308 | TokenType::Const => "a const expression".to_string(), |
1a4d82fc JJ |
309 | } |
310 | } | |
223e47cc LB |
311 | } |
312 | ||
8faf50e0 | 313 | #[derive(Copy, Clone, Debug)] |
e74abb32 | 314 | enum TokenExpectType { |
ea8adc8c XL |
315 | Expect, |
316 | NoExpect, | |
317 | } | |
318 | ||
e74abb32 XL |
319 | /// A sequence separator. |
320 | struct SeqSep { | |
321 | /// The separator token. | |
322 | sep: Option<TokenKind>, | |
323 | /// `true` if a trailing separator is allowed. | |
324 | trailing_sep_allowed: bool, | |
325 | } | |
326 | ||
327 | impl SeqSep { | |
328 | fn trailing_allowed(t: TokenKind) -> SeqSep { | |
dfeec247 | 329 | SeqSep { sep: Some(t), trailing_sep_allowed: true } |
e74abb32 XL |
330 | } |
331 | ||
332 | fn none() -> SeqSep { | |
dfeec247 | 333 | SeqSep { sep: None, trailing_sep_allowed: false } |
e74abb32 XL |
334 | } |
335 | } | |
336 | ||
dfeec247 XL |
337 | pub enum FollowedByType { |
338 | Yes, | |
339 | No, | |
340 | } | |
341 | ||
342 | fn token_descr_opt(token: &Token) -> Option<&'static str> { | |
343 | Some(match token.kind { | |
344 | _ if token.is_special_ident() => "reserved identifier", | |
345 | _ if token.is_used_keyword() => "keyword", | |
346 | _ if token.is_unused_keyword() => "reserved keyword", | |
347 | token::DocComment(..) => "doc comment", | |
348 | _ => return None, | |
349 | }) | |
350 | } | |
351 | ||
352 | pub(super) fn token_descr(token: &Token) -> String { | |
353 | let token_str = pprust::token_to_string(token); | |
354 | match token_descr_opt(token) { | |
355 | Some(prefix) => format!("{} `{}`", prefix, token_str), | |
356 | _ => format!("`{}`", token_str), | |
357 | } | |
358 | } | |
60c5eb7d | 359 | |
1a4d82fc | 360 | impl<'a> Parser<'a> { |
dc9dc135 XL |
361 | pub fn new( |
362 | sess: &'a ParseSess, | |
363 | tokens: TokenStream, | |
dc9dc135 XL |
364 | desugar_doc_comments: bool, |
365 | subparser_name: Option<&'static str>, | |
366 | ) -> Self { | |
c30ab7b3 | 367 | let mut parser = Parser { |
3b2f2976 | 368 | sess, |
dc9dc135 | 369 | token: Token::dummy(), |
29967ef6 | 370 | token_spacing: Spacing::Alone, |
74b04a01 | 371 | prev_token: Token::dummy(), |
d9579d0f | 372 | restrictions: Restrictions::empty(), |
1a4d82fc | 373 | expected_tokens: Vec::new(), |
8bb4bdeb | 374 | token_cursor: TokenCursor { |
29967ef6 | 375 | frame: TokenCursorFrame::new(DelimSpan::dummy(), token::NoDelim, tokens), |
8bb4bdeb | 376 | stack: Vec::new(), |
29967ef6 XL |
377 | num_next_calls: 0, |
378 | desugar_doc_comments, | |
fc512014 | 379 | append_unglued_token: None, |
8bb4bdeb | 380 | }, |
3b2f2976 | 381 | desugar_doc_comments, |
9fa01778 XL |
382 | unmatched_angle_bracket_count: 0, |
383 | max_angle_bracket_count: 0, | |
384 | unclosed_delims: Vec::new(), | |
385 | last_unexpected_token_span: None, | |
416331ca | 386 | last_type_ascription: None, |
dc9dc135 | 387 | subparser_name, |
c30ab7b3 SL |
388 | }; |
389 | ||
74b04a01 XL |
390 | // Make parser point to the first token. |
391 | parser.bump(); | |
7cac9316 | 392 | |
c30ab7b3 SL |
393 | parser |
394 | } | |
395 | ||
29967ef6 XL |
396 | fn next_tok(&mut self, fallback_span: Span) -> (Token, Spacing) { |
397 | let (mut next, spacing) = if self.desugar_doc_comments { | |
7cac9316 XL |
398 | self.token_cursor.next_desugared() |
399 | } else { | |
400 | self.token_cursor.next() | |
8bb4bdeb | 401 | }; |
29967ef6 | 402 | self.token_cursor.num_next_calls += 1; |
fc512014 XL |
403 | // We've retrieved an token from the underlying |
404 | // cursor, so we no longer need to worry about | |
405 | // an unglued token. See `break_and_eat` for more details | |
406 | self.token_cursor.append_unglued_token = None; | |
dc9dc135 | 407 | if next.span.is_dummy() { |
83c7162d | 408 | // Tweak the location for better diagnostics, but keep syntactic context intact. |
74b04a01 | 409 | next.span = fallback_span.with_ctxt(next.span.ctxt()); |
1a4d82fc | 410 | } |
29967ef6 | 411 | (next, spacing) |
1a4d82fc JJ |
412 | } |
413 | ||
29967ef6 | 414 | pub fn unexpected<T>(&mut self) -> PResult<'a, T> { |
9346a6ac | 415 | match self.expect_one_of(&[], &[]) { |
9cc50fc6 | 416 | Err(e) => Err(e), |
e74abb32 XL |
417 | // We can get `Ok(true)` from `recover_closing_delimiter` |
418 | // which is called in `expected_one_of_not_found`. | |
419 | Ok(_) => FatalError.raise(), | |
9346a6ac | 420 | } |
1a4d82fc JJ |
421 | } |
422 | ||
9fa01778 | 423 | /// Expects and consumes the token `t`. Signals an error if the next token is not `t`. |
dc9dc135 | 424 | pub fn expect(&mut self, t: &TokenKind) -> PResult<'a, bool /* recovered */> { |
1a4d82fc JJ |
425 | if self.expected_tokens.is_empty() { |
426 | if self.token == *t { | |
9cc50fc6 | 427 | self.bump(); |
9fa01778 | 428 | Ok(false) |
1a4d82fc | 429 | } else { |
dc9dc135 | 430 | self.unexpected_try_recover(t) |
1a4d82fc JJ |
431 | } |
432 | } else { | |
94b46f34 | 433 | self.expect_one_of(slice::from_ref(t), &[]) |
1a4d82fc JJ |
434 | } |
435 | } | |
436 | ||
437 | /// Expect next token to be edible or inedible token. If edible, | |
438 | /// then consume it; if inedible, then return without consuming | |
439 | /// anything. Signal a fatal error if next token is unexpected. | |
9fa01778 XL |
440 | pub fn expect_one_of( |
441 | &mut self, | |
dc9dc135 XL |
442 | edible: &[TokenKind], |
443 | inedible: &[TokenKind], | |
9fa01778 | 444 | ) -> PResult<'a, bool /* recovered */> { |
dc9dc135 | 445 | if edible.contains(&self.token.kind) { |
9cc50fc6 | 446 | self.bump(); |
9fa01778 | 447 | Ok(false) |
dc9dc135 | 448 | } else if inedible.contains(&self.token.kind) { |
1a4d82fc | 449 | // leave it in the input |
9fa01778 | 450 | Ok(false) |
dc9dc135 | 451 | } else if self.last_unexpected_token_span == Some(self.token.span) { |
9fa01778 | 452 | FatalError.raise(); |
1a4d82fc | 453 | } else { |
dc9dc135 | 454 | self.expected_one_of_not_found(edible, inedible) |
1a4d82fc | 455 | } |
970d7e83 LB |
456 | } |
457 | ||
dfeec247 | 458 | // Public for rustfmt usage. |
f9f354fc | 459 | pub fn parse_ident(&mut self) -> PResult<'a, Ident> { |
2c00a5a8 XL |
460 | self.parse_ident_common(true) |
461 | } | |
462 | ||
f9f354fc | 463 | fn parse_ident_common(&mut self, recover: bool) -> PResult<'a, Ident> { |
74b04a01 XL |
464 | match self.token.ident() { |
465 | Some((ident, is_raw)) => { | |
466 | if !is_raw && ident.is_reserved() { | |
2c00a5a8 XL |
467 | let mut err = self.expected_ident_found(); |
468 | if recover { | |
469 | err.emit(); | |
470 | } else { | |
471 | return Err(err); | |
472 | } | |
041b39d2 | 473 | } |
9cc50fc6 | 474 | self.bump(); |
74b04a01 | 475 | Ok(ident) |
970d7e83 | 476 | } |
74b04a01 XL |
477 | _ => Err(match self.prev_token.kind { |
478 | TokenKind::DocComment(..) => { | |
479 | self.span_fatal_err(self.prev_token.span, Error::UselessDocComment) | |
480 | } | |
481 | _ => self.expected_ident_found(), | |
dfeec247 | 482 | }), |
970d7e83 LB |
483 | } |
484 | } | |
485 | ||
9fa01778 | 486 | /// Checks if the next token is `tok`, and returns `true` if so. |
1a4d82fc | 487 | /// |
7453a54e | 488 | /// This method will automatically add `tok` to `expected_tokens` if `tok` is not |
1a4d82fc | 489 | /// encountered. |
e74abb32 | 490 | fn check(&mut self, tok: &TokenKind) -> bool { |
1a4d82fc | 491 | let is_present = self.token == *tok; |
dfeec247 XL |
492 | if !is_present { |
493 | self.expected_tokens.push(TokenType::Token(tok.clone())); | |
494 | } | |
1a4d82fc | 495 | is_present |
970d7e83 LB |
496 | } |
497 | ||
9fa01778 | 498 | /// Consumes a token 'tok' if it exists. Returns whether the given token was present. |
dc9dc135 | 499 | pub fn eat(&mut self, tok: &TokenKind) -> bool { |
1a4d82fc | 500 | let is_present = self.check(tok); |
dfeec247 XL |
501 | if is_present { |
502 | self.bump() | |
503 | } | |
9cc50fc6 | 504 | is_present |
970d7e83 LB |
505 | } |
506 | ||
e74abb32 XL |
507 | /// If the next token is the given keyword, returns `true` without eating it. |
508 | /// An expectation is also added for diagnostics purposes. | |
dc9dc135 | 509 | fn check_keyword(&mut self, kw: Symbol) -> bool { |
85aaf69f SL |
510 | self.expected_tokens.push(TokenType::Keyword(kw)); |
511 | self.token.is_keyword(kw) | |
512 | } | |
513 | ||
e74abb32 XL |
514 | /// If the next token is the given keyword, eats it and returns `true`. |
515 | /// Otherwise, returns `false`. An expectation is also added for diagnostics purposes. | |
dfeec247 XL |
516 | // Public for rustfmt usage. |
517 | pub fn eat_keyword(&mut self, kw: Symbol) -> bool { | |
85aaf69f | 518 | if self.check_keyword(kw) { |
9cc50fc6 SL |
519 | self.bump(); |
520 | true | |
85aaf69f | 521 | } else { |
9cc50fc6 | 522 | false |
85aaf69f SL |
523 | } |
524 | } | |
525 | ||
dc9dc135 | 526 | fn eat_keyword_noexpect(&mut self, kw: Symbol) -> bool { |
1a4d82fc | 527 | if self.token.is_keyword(kw) { |
9cc50fc6 SL |
528 | self.bump(); |
529 | true | |
1a4d82fc | 530 | } else { |
9cc50fc6 | 531 | false |
1a4d82fc | 532 | } |
970d7e83 LB |
533 | } |
534 | ||
9fa01778 XL |
535 | /// If the given word is not a keyword, signals an error. |
536 | /// If the next token is not the given word, signals an error. | |
537 | /// Otherwise, eats it. | |
dc9dc135 | 538 | fn expect_keyword(&mut self, kw: Symbol) -> PResult<'a, ()> { |
dfeec247 | 539 | if !self.eat_keyword(kw) { self.unexpected() } else { Ok(()) } |
970d7e83 LB |
540 | } |
541 | ||
74b04a01 XL |
542 | /// Is the given keyword `kw` followed by a non-reserved identifier? |
543 | fn is_kw_followed_by_ident(&self, kw: Symbol) -> bool { | |
544 | self.token.is_keyword(kw) && self.look_ahead(1, |t| t.is_ident() && !t.is_reserved_ident()) | |
545 | } | |
546 | ||
e74abb32 XL |
547 | fn check_or_expected(&mut self, ok: bool, typ: TokenType) -> bool { |
548 | if ok { | |
32a655c1 SL |
549 | true |
550 | } else { | |
e74abb32 | 551 | self.expected_tokens.push(typ); |
32a655c1 SL |
552 | false |
553 | } | |
554 | } | |
555 | ||
e74abb32 XL |
556 | fn check_ident(&mut self) -> bool { |
557 | self.check_or_expected(self.token.is_ident(), TokenType::Ident) | |
558 | } | |
559 | ||
32a655c1 | 560 | fn check_path(&mut self) -> bool { |
e74abb32 | 561 | self.check_or_expected(self.token.is_path_start(), TokenType::Path) |
32a655c1 SL |
562 | } |
563 | ||
564 | fn check_type(&mut self) -> bool { | |
e74abb32 | 565 | self.check_or_expected(self.token.can_begin_type(), TokenType::Type) |
32a655c1 SL |
566 | } |
567 | ||
9fa01778 | 568 | fn check_const_arg(&mut self) -> bool { |
e74abb32 XL |
569 | self.check_or_expected(self.token.can_begin_const_arg(), TokenType::Const) |
570 | } | |
571 | ||
29967ef6 XL |
572 | fn check_inline_const(&self, dist: usize) -> bool { |
573 | self.is_keyword_ahead(dist, &[kw::Const]) | |
574 | && self.look_ahead(dist + 1, |t| match t.kind { | |
575 | token::Interpolated(ref nt) => matches!(**nt, token::NtBlock(..)), | |
576 | token::OpenDelim(DelimToken::Brace) => true, | |
577 | _ => false, | |
578 | }) | |
579 | } | |
580 | ||
e74abb32 XL |
581 | /// Checks to see if the next token is either `+` or `+=`. |
582 | /// Otherwise returns `false`. | |
583 | fn check_plus(&mut self) -> bool { | |
584 | self.check_or_expected( | |
585 | self.token.is_like_plus(), | |
586 | TokenType::Token(token::BinOp(token::Plus)), | |
587 | ) | |
9fa01778 XL |
588 | } |
589 | ||
74b04a01 XL |
590 | /// Eats the expected token if it's present possibly breaking |
591 | /// compound tokens like multi-character operators in process. | |
592 | /// Returns `true` if the token was eaten. | |
593 | fn break_and_eat(&mut self, expected: TokenKind) -> bool { | |
594 | if self.token.kind == expected { | |
595 | self.bump(); | |
596 | return true; | |
597 | } | |
598 | match self.token.kind.break_two_token_op() { | |
599 | Some((first, second)) if first == expected => { | |
600 | let first_span = self.sess.source_map().start_point(self.token.span); | |
601 | let second_span = self.token.span.with_lo(first_span.hi()); | |
602 | self.token = Token::new(first, first_span); | |
fc512014 XL |
603 | // Keep track of this token - if we end token capturing now, |
604 | // we'll want to append this token to the captured stream. | |
605 | // | |
606 | // If we consume any additional tokens, then this token | |
607 | // is not needed (we'll capture the entire 'glued' token), | |
608 | // and `next_tok` will set this field to `None` | |
609 | self.token_cursor.append_unglued_token = | |
610 | Some((TokenTree::Token(self.token.clone()), Spacing::Alone)); | |
29967ef6 XL |
611 | // Use the spacing of the glued token as the spacing |
612 | // of the unglued second token. | |
613 | self.bump_with((Token::new(second, second_span), self.token_spacing)); | |
94b46f34 XL |
614 | true |
615 | } | |
74b04a01 XL |
616 | _ => { |
617 | self.expected_tokens.push(TokenType::Token(expected)); | |
618 | false | |
94b46f34 | 619 | } |
94b46f34 XL |
620 | } |
621 | } | |
622 | ||
74b04a01 XL |
623 | /// Eats `+` possibly breaking tokens like `+=` in process. |
624 | fn eat_plus(&mut self) -> bool { | |
625 | self.break_and_eat(token::BinOp(token::Plus)) | |
626 | } | |
627 | ||
628 | /// Eats `&` possibly breaking tokens like `&&` in process. | |
629 | /// Signals an error if `&` is not eaten. | |
9cc50fc6 | 630 | fn expect_and(&mut self) -> PResult<'a, ()> { |
74b04a01 | 631 | if self.break_and_eat(token::BinOp(token::And)) { Ok(()) } else { self.unexpected() } |
ea8adc8c XL |
632 | } |
633 | ||
74b04a01 XL |
634 | /// Eats `|` possibly breaking tokens like `||` in process. |
635 | /// Signals an error if `|` was not eaten. | |
ea8adc8c | 636 | fn expect_or(&mut self) -> PResult<'a, ()> { |
74b04a01 | 637 | if self.break_and_eat(token::BinOp(token::Or)) { Ok(()) } else { self.unexpected() } |
970d7e83 LB |
638 | } |
639 | ||
74b04a01 | 640 | /// Eats `<` possibly breaking tokens like `<<` in process. |
9cc50fc6 | 641 | fn eat_lt(&mut self) -> bool { |
74b04a01 | 642 | let ate = self.break_and_eat(token::Lt); |
9fa01778 XL |
643 | if ate { |
644 | // See doc comment for `unmatched_angle_bracket_count`. | |
645 | self.unmatched_angle_bracket_count += 1; | |
646 | self.max_angle_bracket_count += 1; | |
647 | debug!("eat_lt: (increment) count={:?}", self.unmatched_angle_bracket_count); | |
1a4d82fc | 648 | } |
9fa01778 | 649 | ate |
1a4d82fc JJ |
650 | } |
651 | ||
74b04a01 XL |
652 | /// Eats `<` possibly breaking tokens like `<<` in process. |
653 | /// Signals an error if `<` was not eaten. | |
9cc50fc6 | 654 | fn expect_lt(&mut self) -> PResult<'a, ()> { |
74b04a01 | 655 | if self.eat_lt() { Ok(()) } else { self.unexpected() } |
1a4d82fc JJ |
656 | } |
657 | ||
74b04a01 XL |
658 | /// Eats `>` possibly breaking tokens like `>>` in process. |
659 | /// Signals an error if `>` was not eaten. | |
94b46f34 | 660 | fn expect_gt(&mut self) -> PResult<'a, ()> { |
74b04a01 XL |
661 | if self.break_and_eat(token::Gt) { |
662 | // See doc comment for `unmatched_angle_bracket_count`. | |
663 | if self.unmatched_angle_bracket_count > 0 { | |
664 | self.unmatched_angle_bracket_count -= 1; | |
665 | debug!("expect_gt: (decrement) count={:?}", self.unmatched_angle_bracket_count); | |
dfeec247 | 666 | } |
74b04a01 XL |
667 | Ok(()) |
668 | } else { | |
669 | self.unexpected() | |
1a4d82fc JJ |
670 | } |
671 | } | |
672 | ||
416331ca | 673 | fn expect_any_with_type(&mut self, kets: &[&TokenKind], expect: TokenExpectType) -> bool { |
dfeec247 XL |
674 | kets.iter().any(|k| match expect { |
675 | TokenExpectType::Expect => self.check(k), | |
676 | TokenExpectType::NoExpect => self.token == **k, | |
416331ca XL |
677 | }) |
678 | } | |
679 | ||
e74abb32 | 680 | fn parse_seq_to_before_tokens<T>( |
b7449926 | 681 | &mut self, |
dc9dc135 | 682 | kets: &[&TokenKind], |
b7449926 XL |
683 | sep: SeqSep, |
684 | expect: TokenExpectType, | |
416331ca XL |
685 | mut f: impl FnMut(&mut Parser<'a>) -> PResult<'a, T>, |
686 | ) -> PResult<'a, (Vec<T>, bool /* trailing */, bool /* recovered */)> { | |
9fa01778 XL |
687 | let mut first = true; |
688 | let mut recovered = false; | |
416331ca | 689 | let mut trailing = false; |
c30ab7b3 | 690 | let mut v = vec![]; |
416331ca XL |
691 | while !self.expect_any_with_type(kets, expect) { |
692 | if let token::CloseDelim(..) | token::Eof = self.token.kind { | |
dfeec247 | 693 | break; |
416331ca | 694 | } |
7cac9316 XL |
695 | if let Some(ref t) = sep.sep { |
696 | if first { | |
697 | first = false; | |
698 | } else { | |
9fa01778 XL |
699 | match self.expect(t) { |
700 | Ok(false) => {} | |
701 | Ok(true) => { | |
702 | recovered = true; | |
703 | break; | |
abe05a73 | 704 | } |
60c5eb7d | 705 | Err(mut expect_err) => { |
74b04a01 | 706 | let sp = self.prev_token.span.shrink_to_hi(); |
60c5eb7d XL |
707 | let token_str = pprust::token_kind_to_string(t); |
708 | ||
e1599b0c | 709 | // Attempt to keep parsing if it was a similar separator. |
9fa01778 | 710 | if let Some(ref tokens) = t.similar_tokens() { |
dc9dc135 | 711 | if tokens.contains(&self.token.kind) { |
9fa01778 XL |
712 | self.bump(); |
713 | } | |
714 | } | |
60c5eb7d | 715 | |
f9f354fc XL |
716 | // If this was a missing `@` in a binding pattern |
717 | // bail with a suggestion | |
718 | // https://github.com/rust-lang/rust/issues/72373 | |
f035d41b | 719 | if self.prev_token.is_ident() && self.token.kind == token::DotDot { |
f9f354fc XL |
720 | let msg = format!( |
721 | "if you meant to bind the contents of \ | |
722 | the rest of the array pattern into `{}`, use `@`", | |
723 | pprust::token_to_string(&self.prev_token) | |
724 | ); | |
725 | expect_err | |
726 | .span_suggestion_verbose( | |
727 | self.prev_token.span.shrink_to_hi().until(self.token.span), | |
728 | &msg, | |
729 | " @ ".to_string(), | |
730 | Applicability::MaybeIncorrect, | |
731 | ) | |
732 | .emit(); | |
733 | break; | |
734 | } | |
735 | ||
e1599b0c | 736 | // Attempt to keep parsing if it was an omitted separator. |
9fa01778 XL |
737 | match f(self) { |
738 | Ok(t) => { | |
60c5eb7d XL |
739 | // Parsed successfully, therefore most probably the code only |
740 | // misses a separator. | |
741 | expect_err | |
742 | .span_suggestion_short( | |
5869c6ff | 743 | sp, |
60c5eb7d XL |
744 | &format!("missing `{}`", token_str), |
745 | token_str, | |
746 | Applicability::MaybeIncorrect, | |
747 | ) | |
748 | .emit(); | |
749 | ||
9fa01778 XL |
750 | v.push(t); |
751 | continue; | |
dfeec247 | 752 | } |
9fa01778 | 753 | Err(mut e) => { |
60c5eb7d XL |
754 | // Parsing failed, therefore it must be something more serious |
755 | // than just a missing separator. | |
756 | expect_err.emit(); | |
757 | ||
9fa01778 XL |
758 | e.cancel(); |
759 | break; | |
760 | } | |
abe05a73 XL |
761 | } |
762 | } | |
7453a54e SL |
763 | } |
764 | } | |
7453a54e | 765 | } |
416331ca XL |
766 | if sep.trailing_sep_allowed && self.expect_any_with_type(kets, expect) { |
767 | trailing = true; | |
7453a54e SL |
768 | break; |
769 | } | |
770 | ||
abe05a73 XL |
771 | let t = f(self)?; |
772 | v.push(t); | |
970d7e83 | 773 | } |
7453a54e | 774 | |
416331ca | 775 | Ok((v, trailing, recovered)) |
970d7e83 LB |
776 | } |
777 | ||
dfeec247 XL |
778 | /// Parses a sequence, not including the closing delimiter. The function |
779 | /// `f` must consume tokens until reaching the next separator or | |
780 | /// closing bracket. | |
781 | fn parse_seq_to_before_end<T>( | |
782 | &mut self, | |
783 | ket: &TokenKind, | |
784 | sep: SeqSep, | |
785 | f: impl FnMut(&mut Parser<'a>) -> PResult<'a, T>, | |
786 | ) -> PResult<'a, (Vec<T>, bool, bool)> { | |
787 | self.parse_seq_to_before_tokens(&[ket], sep, TokenExpectType::Expect, f) | |
788 | } | |
789 | ||
790 | /// Parses a sequence, including the closing delimiter. The function | |
791 | /// `f` must consume tokens until reaching the next separator or | |
792 | /// closing bracket. | |
793 | fn parse_seq_to_end<T>( | |
794 | &mut self, | |
795 | ket: &TokenKind, | |
796 | sep: SeqSep, | |
797 | f: impl FnMut(&mut Parser<'a>) -> PResult<'a, T>, | |
798 | ) -> PResult<'a, (Vec<T>, bool /* trailing */)> { | |
799 | let (val, trailing, recovered) = self.parse_seq_to_before_end(ket, sep, f)?; | |
800 | if !recovered { | |
801 | self.eat(ket); | |
802 | } | |
803 | Ok((val, trailing)) | |
804 | } | |
805 | ||
9fa01778 XL |
806 | /// Parses a sequence, including the closing delimiter. The function |
807 | /// `f` must consume tokens until reaching the next separator or | |
1a4d82fc | 808 | /// closing bracket. |
416331ca | 809 | fn parse_unspanned_seq<T>( |
9fa01778 | 810 | &mut self, |
dc9dc135 XL |
811 | bra: &TokenKind, |
812 | ket: &TokenKind, | |
9fa01778 | 813 | sep: SeqSep, |
416331ca XL |
814 | f: impl FnMut(&mut Parser<'a>) -> PResult<'a, T>, |
815 | ) -> PResult<'a, (Vec<T>, bool)> { | |
54a0048b | 816 | self.expect(bra)?; |
dfeec247 | 817 | self.parse_seq_to_end(ket, sep, f) |
416331ca XL |
818 | } |
819 | ||
820 | fn parse_delim_comma_seq<T>( | |
821 | &mut self, | |
822 | delim: DelimToken, | |
823 | f: impl FnMut(&mut Parser<'a>) -> PResult<'a, T>, | |
824 | ) -> PResult<'a, (Vec<T>, bool)> { | |
825 | self.parse_unspanned_seq( | |
826 | &token::OpenDelim(delim), | |
827 | &token::CloseDelim(delim), | |
828 | SeqSep::trailing_allowed(token::Comma), | |
829 | f, | |
830 | ) | |
831 | } | |
832 | ||
833 | fn parse_paren_comma_seq<T>( | |
834 | &mut self, | |
835 | f: impl FnMut(&mut Parser<'a>) -> PResult<'a, T>, | |
836 | ) -> PResult<'a, (Vec<T>, bool)> { | |
837 | self.parse_delim_comma_seq(token::Paren, f) | |
970d7e83 LB |
838 | } |
839 | ||
74b04a01 | 840 | /// Advance the parser by one token using provided token as the next one. |
29967ef6 | 841 | fn bump_with(&mut self, (next_token, next_spacing): (Token, Spacing)) { |
74b04a01 XL |
842 | // Bumping after EOF is a bad sign, usually an infinite loop. |
843 | if self.prev_token.kind == TokenKind::Eof { | |
dfeec247 XL |
844 | let msg = "attempted to bump the parser past EOF (may be stuck in a loop)"; |
845 | self.span_bug(self.token.span, msg); | |
7453a54e SL |
846 | } |
847 | ||
74b04a01 XL |
848 | // Update the current and previous tokens. |
849 | self.prev_token = mem::replace(&mut self.token, next_token); | |
29967ef6 | 850 | self.token_spacing = next_spacing; |
9e0c209e | 851 | |
74b04a01 | 852 | // Diagnostics. |
7453a54e | 853 | self.expected_tokens.clear(); |
223e47cc | 854 | } |
7453a54e | 855 | |
74b04a01 XL |
856 | /// Advance the parser by one token. |
857 | pub fn bump(&mut self) { | |
858 | let next_token = self.next_tok(self.token.span); | |
859 | self.bump_with(next_token); | |
860 | } | |
861 | ||
e74abb32 XL |
862 | /// Look-ahead `dist` tokens of `self.token` and get access to that token there. |
863 | /// When `dist == 0` then the current token is looked at. | |
864 | pub fn look_ahead<R>(&self, dist: usize, looker: impl FnOnce(&Token) -> R) -> R { | |
c30ab7b3 | 865 | if dist == 0 { |
e74abb32 | 866 | return looker(&self.token); |
223e47cc | 867 | } |
8bb4bdeb | 868 | |
dc9dc135 | 869 | let frame = &self.token_cursor.frame; |
29967ef6 | 870 | match frame.tree_cursor.look_ahead(dist - 1) { |
8bb4bdeb | 871 | Some(tree) => match tree { |
29967ef6 | 872 | TokenTree::Token(token) => looker(token), |
dfeec247 | 873 | TokenTree::Delimited(dspan, delim, _) => { |
29967ef6 | 874 | looker(&Token::new(token::OpenDelim(*delim), dspan.open)) |
dfeec247 XL |
875 | } |
876 | }, | |
29967ef6 XL |
877 | None => looker(&Token::new(token::CloseDelim(frame.delim), frame.span.close)), |
878 | } | |
223e47cc | 879 | } |
ff7c6d11 | 880 | |
dc9dc135 XL |
881 | /// Returns whether any of the given keywords are `dist` tokens ahead of the current one. |
882 | fn is_keyword_ahead(&self, dist: usize, kws: &[Symbol]) -> bool { | |
883 | self.look_ahead(dist, |t| kws.iter().any(|&kw| t.is_keyword(kw))) | |
223e47cc | 884 | } |
223e47cc | 885 | |
9fa01778 | 886 | /// Parses asyncness: `async` or nothing. |
74b04a01 | 887 | fn parse_asyncness(&mut self) -> Async { |
dc9dc135 | 888 | if self.eat_keyword(kw::Async) { |
74b04a01 XL |
889 | let span = self.prev_token.uninterpolated_span(); |
890 | Async::Yes { span, closure_id: DUMMY_NODE_ID, return_impl_trait_id: DUMMY_NODE_ID } | |
8faf50e0 | 891 | } else { |
74b04a01 | 892 | Async::No |
8faf50e0 XL |
893 | } |
894 | } | |
895 | ||
9fa01778 | 896 | /// Parses unsafety: `unsafe` or nothing. |
74b04a01 XL |
897 | fn parse_unsafety(&mut self) -> Unsafe { |
898 | if self.eat_keyword(kw::Unsafe) { | |
899 | Unsafe::Yes(self.prev_token.uninterpolated_span()) | |
900 | } else { | |
901 | Unsafe::No | |
902 | } | |
903 | } | |
904 | ||
905 | /// Parses constness: `const` or nothing. | |
906 | fn parse_constness(&mut self) -> Const { | |
29967ef6 XL |
907 | // Avoid const blocks to be parsed as const items |
908 | if self.look_ahead(1, |t| t != &token::OpenDelim(DelimToken::Brace)) | |
909 | && self.eat_keyword(kw::Const) | |
910 | { | |
74b04a01 XL |
911 | Const::Yes(self.prev_token.uninterpolated_span()) |
912 | } else { | |
913 | Const::No | |
914 | } | |
1a4d82fc JJ |
915 | } |
916 | ||
29967ef6 XL |
917 | /// Parses inline const expressions. |
918 | fn parse_const_block(&mut self, span: Span) -> PResult<'a, P<Expr>> { | |
919 | self.sess.gated_spans.gate(sym::inline_const, span); | |
920 | self.eat_keyword(kw::Const); | |
921 | let blk = self.parse_block()?; | |
922 | let anon_const = AnonConst { | |
923 | id: DUMMY_NODE_ID, | |
924 | value: self.mk_expr(blk.span, ExprKind::Block(blk, None), AttrVec::new()), | |
925 | }; | |
fc512014 XL |
926 | let blk_span = anon_const.value.span; |
927 | Ok(self.mk_expr(span.to(blk_span), ExprKind::ConstBlock(anon_const), AttrVec::new())) | |
29967ef6 XL |
928 | } |
929 | ||
416331ca XL |
930 | /// Parses mutability (`mut` or nothing). |
931 | fn parse_mutability(&mut self) -> Mutability { | |
dfeec247 | 932 | if self.eat_keyword(kw::Mut) { Mutability::Mut } else { Mutability::Not } |
223e47cc LB |
933 | } |
934 | ||
e74abb32 XL |
935 | /// Possibly parses mutability (`const` or `mut`). |
936 | fn parse_const_or_mut(&mut self) -> Option<Mutability> { | |
937 | if self.eat_keyword(kw::Mut) { | |
dfeec247 | 938 | Some(Mutability::Mut) |
e74abb32 | 939 | } else if self.eat_keyword(kw::Const) { |
dfeec247 | 940 | Some(Mutability::Not) |
e74abb32 XL |
941 | } else { |
942 | None | |
943 | } | |
944 | } | |
945 | ||
416331ca | 946 | fn parse_field_name(&mut self) -> PResult<'a, Ident> { |
dfeec247 XL |
947 | if let token::Literal(token::Lit { kind: token::Integer, symbol, suffix }) = self.token.kind |
948 | { | |
416331ca XL |
949 | self.expect_no_suffix(self.token.span, "a tuple index", suffix); |
950 | self.bump(); | |
74b04a01 | 951 | Ok(Ident::new(symbol, self.prev_token.span)) |
223e47cc | 952 | } else { |
6a06907d | 953 | self.parse_ident_common(true) |
223e47cc LB |
954 | } |
955 | } | |
956 | ||
60c5eb7d XL |
957 | fn parse_mac_args(&mut self) -> PResult<'a, P<MacArgs>> { |
958 | self.parse_mac_args_common(true).map(P) | |
959 | } | |
960 | ||
961 | fn parse_attr_args(&mut self) -> PResult<'a, MacArgs> { | |
962 | self.parse_mac_args_common(false) | |
963 | } | |
964 | ||
965 | fn parse_mac_args_common(&mut self, delimited_only: bool) -> PResult<'a, MacArgs> { | |
dfeec247 XL |
966 | Ok( |
967 | if self.check(&token::OpenDelim(DelimToken::Paren)) | |
968 | || self.check(&token::OpenDelim(DelimToken::Bracket)) | |
969 | || self.check(&token::OpenDelim(DelimToken::Brace)) | |
970 | { | |
971 | match self.parse_token_tree() { | |
972 | TokenTree::Delimited(dspan, delim, tokens) => | |
60c5eb7d | 973 | // We've confirmed above that there is a delimiter so unwrapping is OK. |
dfeec247 XL |
974 | { |
975 | MacArgs::Delimited(dspan, MacDelimiter::from_token(delim).unwrap(), tokens) | |
60c5eb7d | 976 | } |
dfeec247 | 977 | _ => unreachable!(), |
60c5eb7d | 978 | } |
dfeec247 XL |
979 | } else if !delimited_only { |
980 | if self.eat(&token::Eq) { | |
74b04a01 | 981 | let eq_span = self.prev_token.span; |
dfeec247 XL |
982 | let mut is_interpolated_expr = false; |
983 | if let token::Interpolated(nt) = &self.token.kind { | |
984 | if let token::NtExpr(..) = **nt { | |
985 | is_interpolated_expr = true; | |
986 | } | |
987 | } | |
60c5eb7d | 988 | |
5869c6ff | 989 | // Collect tokens because they are used during lowering to HIR. |
6a06907d | 990 | let expr = self.collect_tokens_no_attrs(|this| this.parse_expr())?; |
fc512014 XL |
991 | let span = expr.span; |
992 | ||
993 | match &expr.kind { | |
994 | // Not gated to supporte things like `doc = $expr` that work on stable. | |
995 | _ if is_interpolated_expr => {} | |
996 | ExprKind::Lit(lit) if lit.kind.is_unsuffixed() => {} | |
997 | _ => self.sess.gated_spans.gate(sym::extended_key_value_attributes, span), | |
998 | } | |
999 | ||
5869c6ff XL |
1000 | let token_kind = token::Interpolated(Lrc::new(token::NtExpr(expr))); |
1001 | MacArgs::Eq(eq_span, Token::new(token_kind, span)) | |
dfeec247 XL |
1002 | } else { |
1003 | MacArgs::Empty | |
1004 | } | |
60c5eb7d | 1005 | } else { |
dfeec247 XL |
1006 | return self.unexpected(); |
1007 | }, | |
1008 | ) | |
416331ca | 1009 | } |
041b39d2 | 1010 | |
e74abb32 XL |
1011 | fn parse_or_use_outer_attributes( |
1012 | &mut self, | |
6a06907d XL |
1013 | already_parsed_attrs: Option<AttrWrapper>, |
1014 | ) -> PResult<'a, AttrWrapper> { | |
416331ca XL |
1015 | if let Some(attrs) = already_parsed_attrs { |
1016 | Ok(attrs) | |
970d7e83 | 1017 | } else { |
6a06907d | 1018 | self.parse_outer_attributes() |
970d7e83 LB |
1019 | } |
1020 | } | |
1021 | ||
416331ca | 1022 | /// Parses a single token tree from the input. |
3dfed10e | 1023 | pub(crate) fn parse_token_tree(&mut self) -> TokenTree { |
dc9dc135 | 1024 | match self.token.kind { |
416331ca | 1025 | token::OpenDelim(..) => { |
29967ef6 XL |
1026 | let depth = self.token_cursor.stack.len(); |
1027 | ||
1028 | // We keep advancing the token cursor until we hit | |
1029 | // the matching `CloseDelim` token. | |
1030 | while !(depth == self.token_cursor.stack.len() | |
1031 | && matches!(self.token.kind, token::CloseDelim(_))) | |
1032 | { | |
1033 | // Advance one token at a time, so `TokenCursor::next()` | |
1034 | // can capture these tokens if necessary. | |
1035 | self.bump(); | |
1036 | } | |
1037 | // We are still inside the frame corresponding | |
1038 | // to the delimited stream we captured, so grab | |
1039 | // the tokens from this frame. | |
1040 | let frame = &self.token_cursor.frame; | |
1041 | let stream = frame.tree_cursor.stream.clone(); | |
1042 | let span = frame.span; | |
1043 | let delim = frame.delim; | |
1044 | // Consume close delimiter | |
0731742a | 1045 | self.bump(); |
29967ef6 | 1046 | TokenTree::Delimited(span, delim, stream) |
dfeec247 | 1047 | } |
416331ca XL |
1048 | token::CloseDelim(_) | token::Eof => unreachable!(), |
1049 | _ => { | |
416331ca | 1050 | self.bump(); |
74b04a01 | 1051 | TokenTree::Token(self.prev_token.clone()) |
0731742a | 1052 | } |
0731742a XL |
1053 | } |
1054 | } | |
1055 | ||
416331ca XL |
1056 | /// Parses a stream of tokens into a list of `TokenTree`s, up to EOF. |
1057 | pub fn parse_all_token_trees(&mut self) -> PResult<'a, Vec<TokenTree>> { | |
1058 | let mut tts = Vec::new(); | |
1059 | while self.token != token::Eof { | |
1060 | tts.push(self.parse_token_tree()); | |
54a0048b | 1061 | } |
416331ca | 1062 | Ok(tts) |
54a0048b SL |
1063 | } |
1064 | ||
416331ca XL |
1065 | pub fn parse_tokens(&mut self) -> TokenStream { |
1066 | let mut result = Vec::new(); | |
1067 | loop { | |
1068 | match self.token.kind { | |
1069 | token::Eof | token::CloseDelim(..) => break, | |
1070 | _ => result.push(self.parse_token_tree().into()), | |
ff7c6d11 | 1071 | } |
223e47cc | 1072 | } |
416331ca | 1073 | TokenStream::new(result) |
223e47cc LB |
1074 | } |
1075 | ||
416331ca XL |
1076 | /// Evaluates the closure with restrictions in place. |
1077 | /// | |
1078 | /// Afters the closure is evaluated, restrictions are reset. | |
e74abb32 | 1079 | fn with_res<T>(&mut self, res: Restrictions, f: impl FnOnce(&mut Self) -> T) -> T { |
416331ca | 1080 | let old = self.restrictions; |
e74abb32 XL |
1081 | self.restrictions = res; |
1082 | let res = f(self); | |
416331ca | 1083 | self.restrictions = old; |
e74abb32 | 1084 | res |
8faf50e0 XL |
1085 | } |
1086 | ||
416331ca XL |
1087 | fn is_crate_vis(&self) -> bool { |
1088 | self.token.is_keyword(kw::Crate) && self.look_ahead(1, |t| t != &token::ModSep) | |
223e47cc LB |
1089 | } |
1090 | ||
416331ca XL |
1091 | /// Parses `pub`, `pub(crate)` and `pub(in path)` plus shortcuts `crate` for `pub(crate)`, |
1092 | /// `pub(self)` for `pub(in self)` and `pub(super)` for `pub(in super)`. | |
1093 | /// If the following element can't be a tuple (i.e., it's a function definition), then | |
1094 | /// it's not a tuple struct field), and the contents within the parentheses isn't valid, | |
1095 | /// so emit a proper diagnostic. | |
1b1a35ee XL |
1096 | // Public for rustfmt usage. |
1097 | pub fn parse_visibility(&mut self, fbt: FollowedByType) -> PResult<'a, Visibility> { | |
416331ca | 1098 | maybe_whole!(self, NtVis, |x| x); |
dc9dc135 | 1099 | |
416331ca XL |
1100 | self.expected_tokens.push(TokenType::Keyword(kw::Crate)); |
1101 | if self.is_crate_vis() { | |
1102 | self.bump(); // `crate` | |
74b04a01 | 1103 | self.sess.gated_spans.gate(sym::crate_visibility_modifier, self.prev_token.span); |
1b1a35ee XL |
1104 | return Ok(Visibility { |
1105 | span: self.prev_token.span, | |
1106 | kind: VisibilityKind::Crate(CrateSugar::JustCrate), | |
1107 | tokens: None, | |
1108 | }); | |
416331ca | 1109 | } |
223e47cc | 1110 | |
416331ca XL |
1111 | if !self.eat_keyword(kw::Pub) { |
1112 | // We need a span for our `Spanned<VisibilityKind>`, but there's inherently no | |
1113 | // keyword to grab a span from for inherited visibility; an empty span at the | |
1114 | // beginning of the current token would seem to be the "Schelling span". | |
1b1a35ee XL |
1115 | return Ok(Visibility { |
1116 | span: self.token.span.shrink_to_lo(), | |
1117 | kind: VisibilityKind::Inherited, | |
1118 | tokens: None, | |
1119 | }); | |
416331ca | 1120 | } |
74b04a01 | 1121 | let lo = self.prev_token.span; |
223e47cc | 1122 | |
416331ca XL |
1123 | if self.check(&token::OpenDelim(token::Paren)) { |
1124 | // We don't `self.bump()` the `(` yet because this might be a struct definition where | |
1125 | // `()` or a tuple might be allowed. For example, `struct Struct(pub (), pub (usize));`. | |
1126 | // Because of this, we only `bump` the `(` if we're assured it is appropriate to do so | |
1127 | // by the following tokens. | |
dfeec247 XL |
1128 | if self.is_keyword_ahead(1, &[kw::Crate]) && self.look_ahead(2, |t| t != &token::ModSep) |
1129 | // account for `pub(crate::foo)` | |
416331ca | 1130 | { |
e74abb32 | 1131 | // Parse `pub(crate)`. |
416331ca XL |
1132 | self.bump(); // `(` |
1133 | self.bump(); // `crate` | |
1134 | self.expect(&token::CloseDelim(token::Paren))?; // `)` | |
e74abb32 | 1135 | let vis = VisibilityKind::Crate(CrateSugar::PubCrate); |
1b1a35ee XL |
1136 | return Ok(Visibility { |
1137 | span: lo.to(self.prev_token.span), | |
1138 | kind: vis, | |
1139 | tokens: None, | |
1140 | }); | |
416331ca | 1141 | } else if self.is_keyword_ahead(1, &[kw::In]) { |
e74abb32 | 1142 | // Parse `pub(in path)`. |
416331ca XL |
1143 | self.bump(); // `(` |
1144 | self.bump(); // `in` | |
1145 | let path = self.parse_path(PathStyle::Mod)?; // `path` | |
1146 | self.expect(&token::CloseDelim(token::Paren))?; // `)` | |
dfeec247 | 1147 | let vis = VisibilityKind::Restricted { path: P(path), id: ast::DUMMY_NODE_ID }; |
1b1a35ee XL |
1148 | return Ok(Visibility { |
1149 | span: lo.to(self.prev_token.span), | |
1150 | kind: vis, | |
1151 | tokens: None, | |
1152 | }); | |
e74abb32 XL |
1153 | } else if self.look_ahead(2, |t| t == &token::CloseDelim(token::Paren)) |
1154 | && self.is_keyword_ahead(1, &[kw::Super, kw::SelfLower]) | |
416331ca | 1155 | { |
e74abb32 | 1156 | // Parse `pub(self)` or `pub(super)`. |
416331ca XL |
1157 | self.bump(); // `(` |
1158 | let path = self.parse_path(PathStyle::Mod)?; // `super`/`self` | |
1159 | self.expect(&token::CloseDelim(token::Paren))?; // `)` | |
dfeec247 | 1160 | let vis = VisibilityKind::Restricted { path: P(path), id: ast::DUMMY_NODE_ID }; |
1b1a35ee XL |
1161 | return Ok(Visibility { |
1162 | span: lo.to(self.prev_token.span), | |
1163 | kind: vis, | |
1164 | tokens: None, | |
1165 | }); | |
60c5eb7d XL |
1166 | } else if let FollowedByType::No = fbt { |
1167 | // Provide this diagnostic if a type cannot follow; | |
1168 | // in particular, if this is not a tuple struct. | |
e74abb32 XL |
1169 | self.recover_incorrect_vis_restriction()?; |
1170 | // Emit diagnostic, but continue with public visibility. | |
532ac7d7 | 1171 | } |
223e47cc | 1172 | } |
223e47cc | 1173 | |
1b1a35ee | 1174 | Ok(Visibility { span: lo, kind: VisibilityKind::Public, tokens: None }) |
223e47cc LB |
1175 | } |
1176 | ||
e74abb32 XL |
1177 | /// Recovery for e.g. `pub(something) fn ...` or `struct X { pub(something) y: Z }` |
1178 | fn recover_incorrect_vis_restriction(&mut self) -> PResult<'a, ()> { | |
1179 | self.bump(); // `(` | |
1180 | let path = self.parse_path(PathStyle::Mod)?; | |
dfeec247 | 1181 | self.expect(&token::CloseDelim(token::Paren))?; // `)` |
e74abb32 XL |
1182 | |
1183 | let msg = "incorrect visibility restriction"; | |
1184 | let suggestion = r##"some possible visibility restrictions are: | |
1185 | `pub(crate)`: visible only on the current crate | |
1186 | `pub(super)`: visible only in the current module's parent | |
1187 | `pub(in path::to::module)`: visible only on the specified path"##; | |
1188 | ||
1189 | let path_str = pprust::path_to_string(&path); | |
1190 | ||
1191 | struct_span_err!(self.sess.span_diagnostic, path.span, E0704, "{}", msg) | |
1192 | .help(suggestion) | |
1193 | .span_suggestion( | |
1194 | path.span, | |
1195 | &format!("make this visible only to module `{}` with `in`", path_str), | |
1196 | format!("in {}", path_str), | |
1197 | Applicability::MachineApplicable, | |
1198 | ) | |
1199 | .emit(); | |
1200 | ||
1201 | Ok(()) | |
1202 | } | |
1203 | ||
60c5eb7d | 1204 | /// Parses `extern string_literal?`. |
6a06907d XL |
1205 | fn parse_extern(&mut self) -> Extern { |
1206 | if self.eat_keyword(kw::Extern) { Extern::from_abi(self.parse_abi()) } else { Extern::None } | |
e74abb32 XL |
1207 | } |
1208 | ||
60c5eb7d XL |
1209 | /// Parses a string literal as an ABI spec. |
1210 | fn parse_abi(&mut self) -> Option<StrLit> { | |
1211 | match self.parse_str_lit() { | |
1212 | Ok(str_lit) => Some(str_lit), | |
1213 | Err(Some(lit)) => match lit.kind { | |
1214 | ast::LitKind::Err(_) => None, | |
1215 | _ => { | |
1216 | self.struct_span_err(lit.span, "non-string ABI literal") | |
1217 | .span_suggestion( | |
1218 | lit.span, | |
1219 | "specify the ABI with a string literal", | |
1220 | "\"C\"".to_string(), | |
1221 | Applicability::MaybeIncorrect, | |
1222 | ) | |
1223 | .emit(); | |
1224 | None | |
223e47cc | 1225 | } |
dfeec247 | 1226 | }, |
60c5eb7d | 1227 | Err(None) => None, |
223e47cc LB |
1228 | } |
1229 | } | |
1230 | ||
6a06907d | 1231 | pub fn collect_tokens_no_attrs<R: AstLike>( |
5869c6ff XL |
1232 | &mut self, |
1233 | f: impl FnOnce(&mut Self) -> PResult<'a, R>, | |
1234 | ) -> PResult<'a, R> { | |
6a06907d XL |
1235 | // The only reason to call `collect_tokens_no_attrs` is if you want tokens, so use |
1236 | // `ForceCollect::Yes` | |
1237 | self.collect_tokens_trailing_token( | |
1238 | AttrWrapper::empty(), | |
1239 | ForceCollect::Yes, | |
1240 | |this, _attrs| Ok((f(this)?, TrailingToken::None)), | |
1241 | ) | |
3b2f2976 XL |
1242 | } |
1243 | ||
0531ce1d XL |
1244 | /// `::{` or `::*` |
1245 | fn is_import_coupler(&mut self) -> bool { | |
dfeec247 XL |
1246 | self.check(&token::ModSep) |
1247 | && self.look_ahead(1, |t| { | |
1248 | *t == token::OpenDelim(token::Brace) || *t == token::BinOp(token::Star) | |
1249 | }) | |
a7813a04 | 1250 | } |
1b1a35ee XL |
1251 | |
1252 | pub fn clear_expected_tokens(&mut self) { | |
1253 | self.expected_tokens.clear(); | |
1254 | } | |
e74abb32 | 1255 | } |
532ac7d7 | 1256 | |
e74abb32 XL |
1257 | crate fn make_unclosed_delims_error( |
1258 | unmatched: UnmatchedBrace, | |
1259 | sess: &ParseSess, | |
1260 | ) -> Option<DiagnosticBuilder<'_>> { | |
1261 | // `None` here means an `Eof` was found. We already emit those errors elsewhere, we add them to | |
1262 | // `unmatched_braces` only for error recovery in the `Parser`. | |
1263 | let found_delim = unmatched.found_delim?; | |
dfeec247 XL |
1264 | let mut err = sess.span_diagnostic.struct_span_err( |
1265 | unmatched.found_span, | |
1266 | &format!( | |
1267 | "mismatched closing delimiter: `{}`", | |
1268 | pprust::token_kind_to_string(&token::CloseDelim(found_delim)), | |
1269 | ), | |
1270 | ); | |
1271 | err.span_label(unmatched.found_span, "mismatched closing delimiter"); | |
e74abb32 | 1272 | if let Some(sp) = unmatched.candidate_span { |
dfeec247 | 1273 | err.span_label(sp, "closing delimiter possibly meant for this"); |
e74abb32 XL |
1274 | } |
1275 | if let Some(sp) = unmatched.unclosed_span { | |
dfeec247 | 1276 | err.span_label(sp, "unclosed delimiter"); |
e74abb32 XL |
1277 | } |
1278 | Some(err) | |
223e47cc | 1279 | } |
9fa01778 | 1280 | |
e74abb32 | 1281 | pub fn emit_unclosed_delims(unclosed_delims: &mut Vec<UnmatchedBrace>, sess: &ParseSess) { |
dfeec247 XL |
1282 | *sess.reached_eof.borrow_mut() |= |
1283 | unclosed_delims.iter().any(|unmatched_delim| unmatched_delim.found_delim.is_none()); | |
e74abb32 | 1284 | for unmatched in unclosed_delims.drain(..) { |
f9f354fc | 1285 | if let Some(mut e) = make_unclosed_delims_error(unmatched, sess) { |
74b04a01 | 1286 | e.emit(); |
f9f354fc | 1287 | } |
9fa01778 | 1288 | } |
9fa01778 | 1289 | } |