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Commit | Line | Data |
---|---|---|
e74abb32 | 1 | pub mod attr; |
3dfed10e | 2 | mod diagnostics; |
416331ca | 3 | mod expr; |
3dfed10e | 4 | mod generics; |
416331ca | 5 | mod item; |
3dfed10e | 6 | mod nonterminal; |
dfeec247 | 7 | mod pat; |
416331ca | 8 | mod path; |
dfeec247 | 9 | mod stmt; |
3dfed10e | 10 | mod ty; |
416331ca | 11 | |
60c5eb7d | 12 | use crate::lexer::UnmatchedBrace; |
29967ef6 | 13 | pub use diagnostics::AttemptLocalParseRecovery; |
3dfed10e XL |
14 | use diagnostics::Error; |
15 | pub use path::PathStyle; | |
60c5eb7d | 16 | |
74b04a01 XL |
17 | use rustc_ast::ptr::P; |
18 | use rustc_ast::token::{self, DelimToken, Token, TokenKind}; | |
29967ef6 | 19 | use rustc_ast::tokenstream::{self, DelimSpan, LazyTokenStream, Spacing}; |
fc512014 | 20 | use rustc_ast::tokenstream::{CreateTokenStream, TokenStream, TokenTree, TreeAndSpacing}; |
3dfed10e | 21 | use rustc_ast::DUMMY_NODE_ID; |
5869c6ff XL |
22 | use rustc_ast::{self as ast, AnonConst, AttrStyle, AttrVec, Const, CrateSugar, Extern, HasTokens}; |
23 | use rustc_ast::{Async, Expr, ExprKind, MacArgs, MacDelimiter, Mutability, StrLit, Unsafe}; | |
29967ef6 | 24 | use rustc_ast::{Visibility, VisibilityKind}; |
74b04a01 | 25 | use rustc_ast_pretty::pprust; |
fc512014 | 26 | use rustc_data_structures::sync::Lrc; |
29967ef6 XL |
27 | use rustc_errors::PResult; |
28 | use rustc_errors::{struct_span_err, Applicability, DiagnosticBuilder, FatalError}; | |
74b04a01 | 29 | use rustc_session::parse::ParseSess; |
1b1a35ee | 30 | use rustc_span::source_map::{Span, DUMMY_SP}; |
f9f354fc | 31 | use rustc_span::symbol::{kw, sym, Ident, Symbol}; |
3dfed10e | 32 | use tracing::debug; |
74b04a01 | 33 | |
dfeec247 | 34 | use std::{cmp, mem, slice}; |
60c5eb7d | 35 | |
9fa01778 | 36 | bitflags::bitflags! { |
94b46f34 | 37 | struct Restrictions: u8 { |
ea8adc8c XL |
38 | const STMT_EXPR = 1 << 0; |
39 | const NO_STRUCT_LITERAL = 1 << 1; | |
29967ef6 | 40 | const CONST_EXPR = 1 << 2; |
1a4d82fc | 41 | } |
223e47cc LB |
42 | } |
43 | ||
8faf50e0 | 44 | #[derive(Clone, Copy, PartialEq, Debug)] |
e74abb32 | 45 | enum SemiColonMode { |
7453a54e SL |
46 | Break, |
47 | Ignore, | |
9fa01778 | 48 | Comma, |
7453a54e SL |
49 | } |
50 | ||
8faf50e0 | 51 | #[derive(Clone, Copy, PartialEq, Debug)] |
e74abb32 | 52 | enum BlockMode { |
cc61c64b XL |
53 | Break, |
54 | Ignore, | |
55 | } | |
56 | ||
5869c6ff XL |
57 | /// Whether or not we should force collection of tokens for an AST node, |
58 | /// regardless of whether or not it has attributes | |
59 | pub enum ForceCollect { | |
60 | Yes, | |
61 | No, | |
62 | } | |
63 | ||
64 | pub enum TrailingToken { | |
65 | None, | |
66 | Semi, | |
67 | } | |
68 | ||
e1599b0c | 69 | /// Like `maybe_whole_expr`, but for things other than expressions. |
416331ca | 70 | #[macro_export] |
1a4d82fc | 71 | macro_rules! maybe_whole { |
c30ab7b3 | 72 | ($p:expr, $constructor:ident, |$x:ident| $e:expr) => { |
dc9dc135 | 73 | if let token::Interpolated(nt) = &$p.token.kind { |
532ac7d7 XL |
74 | if let token::$constructor(x) = &**nt { |
75 | let $x = x.clone(); | |
c30ab7b3 SL |
76 | $p.bump(); |
77 | return Ok($e); | |
223e47cc | 78 | } |
1a4d82fc | 79 | } |
c30ab7b3 | 80 | }; |
1a4d82fc | 81 | } |
223e47cc | 82 | |
532ac7d7 | 83 | /// If the next tokens are ill-formed `$ty::` recover them as `<$ty>::`. |
416331ca | 84 | #[macro_export] |
532ac7d7 XL |
85 | macro_rules! maybe_recover_from_interpolated_ty_qpath { |
86 | ($self: expr, $allow_qpath_recovery: expr) => { | |
87 | if $allow_qpath_recovery && $self.look_ahead(1, |t| t == &token::ModSep) { | |
dc9dc135 | 88 | if let token::Interpolated(nt) = &$self.token.kind { |
532ac7d7 XL |
89 | if let token::NtTy(ty) = &**nt { |
90 | let ty = ty.clone(); | |
91 | $self.bump(); | |
74b04a01 | 92 | return $self.maybe_recover_from_bad_qpath_stage_2($self.prev_token.span, ty); |
532ac7d7 XL |
93 | } |
94 | } | |
95 | } | |
dfeec247 | 96 | }; |
532ac7d7 XL |
97 | } |
98 | ||
041b39d2 | 99 | #[derive(Clone)] |
1a4d82fc JJ |
100 | pub struct Parser<'a> { |
101 | pub sess: &'a ParseSess, | |
74b04a01 | 102 | /// The current token. |
dc9dc135 | 103 | pub token: Token, |
29967ef6 XL |
104 | /// The spacing for the current token |
105 | pub token_spacing: Spacing, | |
74b04a01 XL |
106 | /// The previous token. |
107 | pub prev_token: Token, | |
94b46f34 | 108 | restrictions: Restrictions, |
e74abb32 | 109 | expected_tokens: Vec<TokenType>, |
29967ef6 XL |
110 | // Important: This must only be advanced from `next_tok` |
111 | // to ensure that `token_cursor.num_next_calls` is updated properly | |
e1599b0c | 112 | token_cursor: TokenCursor, |
94b46f34 | 113 | desugar_doc_comments: bool, |
9fa01778 XL |
114 | /// This field is used to keep track of how many left angle brackets we have seen. This is |
115 | /// required in order to detect extra leading left angle brackets (`<` characters) and error | |
116 | /// appropriately. | |
117 | /// | |
118 | /// See the comments in the `parse_path_segment` function for more details. | |
e74abb32 XL |
119 | unmatched_angle_bracket_count: u32, |
120 | max_angle_bracket_count: u32, | |
e1599b0c | 121 | /// A list of all unclosed delimiters found by the lexer. If an entry is used for error recovery |
9fa01778 XL |
122 | /// it gets removed from here. Every entry left at the end gets emitted as an independent |
123 | /// error. | |
e74abb32 XL |
124 | pub(super) unclosed_delims: Vec<UnmatchedBrace>, |
125 | last_unexpected_token_span: Option<Span>, | |
3dfed10e XL |
126 | /// Span pointing at the `:` for the last type ascription the parser has seen, and whether it |
127 | /// looked like it could have been a mistyped path or literal `Option:Some(42)`). | |
e74abb32 | 128 | pub last_type_ascription: Option<(Span, bool /* likely path typo */)>, |
dc9dc135 | 129 | /// If present, this `Parser` is not parsing Rust code but rather a macro call. |
e74abb32 | 130 | subparser_name: Option<&'static str>, |
1a4d82fc JJ |
131 | } |
132 | ||
9fa01778 XL |
133 | impl<'a> Drop for Parser<'a> { |
134 | fn drop(&mut self) { | |
e74abb32 | 135 | emit_unclosed_delims(&mut self.unclosed_delims, &self.sess); |
9fa01778 XL |
136 | } |
137 | } | |
7cac9316 | 138 | |
041b39d2 | 139 | #[derive(Clone)] |
e1599b0c XL |
140 | struct TokenCursor { |
141 | frame: TokenCursorFrame, | |
142 | stack: Vec<TokenCursorFrame>, | |
29967ef6 XL |
143 | desugar_doc_comments: bool, |
144 | // Counts the number of calls to `next` or `next_desugared`, | |
145 | // depending on whether `desugar_doc_comments` is set. | |
146 | num_next_calls: usize, | |
fc512014 XL |
147 | // During parsing, we may sometimes need to 'unglue' a |
148 | // glued token into two component tokens | |
149 | // (e.g. '>>' into '>' and '>), so that the parser | |
150 | // can consume them one at a time. This process | |
151 | // bypasses the normal capturing mechanism | |
152 | // (e.g. `num_next_calls` will not be incremented), | |
153 | // since the 'unglued' tokens due not exist in | |
154 | // the original `TokenStream`. | |
155 | // | |
156 | // If we end up consuming both unglued tokens, | |
157 | // then this is not an issue - we'll end up | |
158 | // capturing the single 'glued' token. | |
159 | // | |
160 | // However, in certain circumstances, we may | |
161 | // want to capture just the first 'unglued' token. | |
162 | // For example, capturing the `Vec<u8>` | |
163 | // in `Option<Vec<u8>>` requires us to unglue | |
164 | // the trailing `>>` token. The `append_unglued_token` | |
165 | // field is used to track this token - it gets | |
166 | // appended to the captured stream when | |
167 | // we evaluate a `LazyTokenStream` | |
168 | append_unglued_token: Option<TreeAndSpacing>, | |
8bb4bdeb XL |
169 | } |
170 | ||
041b39d2 | 171 | #[derive(Clone)] |
e1599b0c XL |
172 | struct TokenCursorFrame { |
173 | delim: token::DelimToken, | |
174 | span: DelimSpan, | |
175 | open_delim: bool, | |
176 | tree_cursor: tokenstream::Cursor, | |
177 | close_delim: bool, | |
3b2f2976 XL |
178 | } |
179 | ||
8bb4bdeb | 180 | impl TokenCursorFrame { |
29967ef6 | 181 | fn new(span: DelimSpan, delim: DelimToken, tts: TokenStream) -> Self { |
8bb4bdeb | 182 | TokenCursorFrame { |
dc9dc135 XL |
183 | delim, |
184 | span, | |
0731742a | 185 | open_delim: delim == token::NoDelim, |
29967ef6 | 186 | tree_cursor: tts.into_trees(), |
0731742a | 187 | close_delim: delim == token::NoDelim, |
8bb4bdeb XL |
188 | } |
189 | } | |
190 | } | |
191 | ||
192 | impl TokenCursor { | |
29967ef6 | 193 | fn next(&mut self) -> (Token, Spacing) { |
8bb4bdeb | 194 | loop { |
29967ef6 | 195 | let (tree, spacing) = if !self.frame.open_delim { |
8bb4bdeb | 196 | self.frame.open_delim = true; |
f9f354fc | 197 | TokenTree::open_tt(self.frame.span, self.frame.delim).into() |
1b1a35ee | 198 | } else if let Some(tree) = self.frame.tree_cursor.next_with_spacing() { |
8bb4bdeb XL |
199 | tree |
200 | } else if !self.frame.close_delim { | |
201 | self.frame.close_delim = true; | |
f9f354fc | 202 | TokenTree::close_tt(self.frame.span, self.frame.delim).into() |
8bb4bdeb XL |
203 | } else if let Some(frame) = self.stack.pop() { |
204 | self.frame = frame; | |
dfeec247 | 205 | continue; |
8bb4bdeb | 206 | } else { |
29967ef6 | 207 | (TokenTree::Token(Token::new(token::Eof, DUMMY_SP)), Spacing::Alone) |
8bb4bdeb XL |
208 | }; |
209 | ||
29967ef6 XL |
210 | match tree { |
211 | TokenTree::Token(token) => { | |
212 | return (token, spacing); | |
f9f354fc | 213 | } |
0731742a | 214 | TokenTree::Delimited(sp, delim, tts) => { |
29967ef6 | 215 | let frame = TokenCursorFrame::new(sp, delim, tts); |
8bb4bdeb XL |
216 | self.stack.push(mem::replace(&mut self.frame, frame)); |
217 | } | |
218 | } | |
219 | } | |
220 | } | |
221 | ||
29967ef6 | 222 | fn next_desugared(&mut self) -> (Token, Spacing) { |
3dfed10e | 223 | let (data, attr_style, sp) = match self.next() { |
29967ef6 | 224 | (Token { kind: token::DocComment(_, attr_style, data), span }, _) => { |
3dfed10e XL |
225 | (data, attr_style, span) |
226 | } | |
7cac9316 | 227 | tok => return tok, |
8bb4bdeb XL |
228 | }; |
229 | ||
8bb4bdeb XL |
230 | // Searches for the occurrences of `"#*` and returns the minimum number of `#`s |
231 | // required to wrap the text. | |
232 | let mut num_of_hashes = 0; | |
233 | let mut count = 0; | |
3dfed10e | 234 | for ch in data.as_str().chars() { |
8bb4bdeb XL |
235 | count = match ch { |
236 | '"' => 1, | |
237 | '#' if count > 0 => count + 1, | |
238 | _ => 0, | |
239 | }; | |
240 | num_of_hashes = cmp::max(num_of_hashes, count); | |
241 | } | |
242 | ||
b7449926 | 243 | let delim_span = DelimSpan::from_single(sp); |
0731742a XL |
244 | let body = TokenTree::Delimited( |
245 | delim_span, | |
246 | token::Bracket, | |
dc9dc135 XL |
247 | [ |
248 | TokenTree::token(token::Ident(sym::doc, false), sp), | |
249 | TokenTree::token(token::Eq, sp), | |
3dfed10e | 250 | TokenTree::token(TokenKind::lit(token::StrRaw(num_of_hashes), data, None), sp), |
0731742a | 251 | ] |
dfeec247 XL |
252 | .iter() |
253 | .cloned() | |
74b04a01 | 254 | .collect::<TokenStream>(), |
0731742a | 255 | ); |
8bb4bdeb | 256 | |
dfeec247 XL |
257 | self.stack.push(mem::replace( |
258 | &mut self.frame, | |
259 | TokenCursorFrame::new( | |
260 | delim_span, | |
261 | token::NoDelim, | |
29967ef6 | 262 | if attr_style == AttrStyle::Inner { |
dfeec247 XL |
263 | [TokenTree::token(token::Pound, sp), TokenTree::token(token::Not, sp), body] |
264 | .iter() | |
265 | .cloned() | |
266 | .collect::<TokenStream>() | |
267 | } else { | |
268 | [TokenTree::token(token::Pound, sp), body] | |
269 | .iter() | |
270 | .cloned() | |
271 | .collect::<TokenStream>() | |
272 | }, | |
273 | ), | |
274 | )); | |
8bb4bdeb XL |
275 | |
276 | self.next() | |
277 | } | |
278 | } | |
279 | ||
5869c6ff | 280 | #[derive(Debug, Clone, PartialEq)] |
e74abb32 | 281 | enum TokenType { |
dc9dc135 XL |
282 | Token(TokenKind), |
283 | Keyword(Symbol), | |
1a4d82fc | 284 | Operator, |
32a655c1 SL |
285 | Lifetime, |
286 | Ident, | |
287 | Path, | |
288 | Type, | |
9fa01778 | 289 | Const, |
1a4d82fc | 290 | } |
223e47cc | 291 | |
1a4d82fc | 292 | impl TokenType { |
e74abb32 | 293 | fn to_string(&self) -> String { |
1a4d82fc | 294 | match *self { |
dc9dc135 XL |
295 | TokenType::Token(ref t) => format!("`{}`", pprust::token_kind_to_string(t)), |
296 | TokenType::Keyword(kw) => format!("`{}`", kw), | |
32a655c1 SL |
297 | TokenType::Operator => "an operator".to_string(), |
298 | TokenType::Lifetime => "lifetime".to_string(), | |
299 | TokenType::Ident => "identifier".to_string(), | |
300 | TokenType::Path => "path".to_string(), | |
301 | TokenType::Type => "type".to_string(), | |
fc512014 | 302 | TokenType::Const => "a const expression".to_string(), |
1a4d82fc JJ |
303 | } |
304 | } | |
223e47cc LB |
305 | } |
306 | ||
8faf50e0 | 307 | #[derive(Copy, Clone, Debug)] |
e74abb32 | 308 | enum TokenExpectType { |
ea8adc8c XL |
309 | Expect, |
310 | NoExpect, | |
311 | } | |
312 | ||
e74abb32 XL |
313 | /// A sequence separator. |
314 | struct SeqSep { | |
315 | /// The separator token. | |
316 | sep: Option<TokenKind>, | |
317 | /// `true` if a trailing separator is allowed. | |
318 | trailing_sep_allowed: bool, | |
319 | } | |
320 | ||
321 | impl SeqSep { | |
322 | fn trailing_allowed(t: TokenKind) -> SeqSep { | |
dfeec247 | 323 | SeqSep { sep: Some(t), trailing_sep_allowed: true } |
e74abb32 XL |
324 | } |
325 | ||
326 | fn none() -> SeqSep { | |
dfeec247 | 327 | SeqSep { sep: None, trailing_sep_allowed: false } |
e74abb32 XL |
328 | } |
329 | } | |
330 | ||
dfeec247 XL |
331 | pub enum FollowedByType { |
332 | Yes, | |
333 | No, | |
334 | } | |
335 | ||
336 | fn token_descr_opt(token: &Token) -> Option<&'static str> { | |
337 | Some(match token.kind { | |
338 | _ if token.is_special_ident() => "reserved identifier", | |
339 | _ if token.is_used_keyword() => "keyword", | |
340 | _ if token.is_unused_keyword() => "reserved keyword", | |
341 | token::DocComment(..) => "doc comment", | |
342 | _ => return None, | |
343 | }) | |
344 | } | |
345 | ||
346 | pub(super) fn token_descr(token: &Token) -> String { | |
347 | let token_str = pprust::token_to_string(token); | |
348 | match token_descr_opt(token) { | |
349 | Some(prefix) => format!("{} `{}`", prefix, token_str), | |
350 | _ => format!("`{}`", token_str), | |
351 | } | |
352 | } | |
60c5eb7d | 353 | |
1a4d82fc | 354 | impl<'a> Parser<'a> { |
dc9dc135 XL |
355 | pub fn new( |
356 | sess: &'a ParseSess, | |
357 | tokens: TokenStream, | |
dc9dc135 XL |
358 | desugar_doc_comments: bool, |
359 | subparser_name: Option<&'static str>, | |
360 | ) -> Self { | |
c30ab7b3 | 361 | let mut parser = Parser { |
3b2f2976 | 362 | sess, |
dc9dc135 | 363 | token: Token::dummy(), |
29967ef6 | 364 | token_spacing: Spacing::Alone, |
74b04a01 | 365 | prev_token: Token::dummy(), |
d9579d0f | 366 | restrictions: Restrictions::empty(), |
1a4d82fc | 367 | expected_tokens: Vec::new(), |
8bb4bdeb | 368 | token_cursor: TokenCursor { |
29967ef6 | 369 | frame: TokenCursorFrame::new(DelimSpan::dummy(), token::NoDelim, tokens), |
8bb4bdeb | 370 | stack: Vec::new(), |
29967ef6 XL |
371 | num_next_calls: 0, |
372 | desugar_doc_comments, | |
fc512014 | 373 | append_unglued_token: None, |
8bb4bdeb | 374 | }, |
3b2f2976 | 375 | desugar_doc_comments, |
9fa01778 XL |
376 | unmatched_angle_bracket_count: 0, |
377 | max_angle_bracket_count: 0, | |
378 | unclosed_delims: Vec::new(), | |
379 | last_unexpected_token_span: None, | |
416331ca | 380 | last_type_ascription: None, |
dc9dc135 | 381 | subparser_name, |
c30ab7b3 SL |
382 | }; |
383 | ||
74b04a01 XL |
384 | // Make parser point to the first token. |
385 | parser.bump(); | |
7cac9316 | 386 | |
c30ab7b3 SL |
387 | parser |
388 | } | |
389 | ||
29967ef6 XL |
390 | fn next_tok(&mut self, fallback_span: Span) -> (Token, Spacing) { |
391 | let (mut next, spacing) = if self.desugar_doc_comments { | |
7cac9316 XL |
392 | self.token_cursor.next_desugared() |
393 | } else { | |
394 | self.token_cursor.next() | |
8bb4bdeb | 395 | }; |
29967ef6 | 396 | self.token_cursor.num_next_calls += 1; |
fc512014 XL |
397 | // We've retrieved an token from the underlying |
398 | // cursor, so we no longer need to worry about | |
399 | // an unglued token. See `break_and_eat` for more details | |
400 | self.token_cursor.append_unglued_token = None; | |
dc9dc135 | 401 | if next.span.is_dummy() { |
83c7162d | 402 | // Tweak the location for better diagnostics, but keep syntactic context intact. |
74b04a01 | 403 | next.span = fallback_span.with_ctxt(next.span.ctxt()); |
1a4d82fc | 404 | } |
29967ef6 | 405 | (next, spacing) |
1a4d82fc JJ |
406 | } |
407 | ||
29967ef6 | 408 | pub fn unexpected<T>(&mut self) -> PResult<'a, T> { |
9346a6ac | 409 | match self.expect_one_of(&[], &[]) { |
9cc50fc6 | 410 | Err(e) => Err(e), |
e74abb32 XL |
411 | // We can get `Ok(true)` from `recover_closing_delimiter` |
412 | // which is called in `expected_one_of_not_found`. | |
413 | Ok(_) => FatalError.raise(), | |
9346a6ac | 414 | } |
1a4d82fc JJ |
415 | } |
416 | ||
9fa01778 | 417 | /// Expects and consumes the token `t`. Signals an error if the next token is not `t`. |
dc9dc135 | 418 | pub fn expect(&mut self, t: &TokenKind) -> PResult<'a, bool /* recovered */> { |
1a4d82fc JJ |
419 | if self.expected_tokens.is_empty() { |
420 | if self.token == *t { | |
9cc50fc6 | 421 | self.bump(); |
9fa01778 | 422 | Ok(false) |
1a4d82fc | 423 | } else { |
dc9dc135 | 424 | self.unexpected_try_recover(t) |
1a4d82fc JJ |
425 | } |
426 | } else { | |
94b46f34 | 427 | self.expect_one_of(slice::from_ref(t), &[]) |
1a4d82fc JJ |
428 | } |
429 | } | |
430 | ||
431 | /// Expect next token to be edible or inedible token. If edible, | |
432 | /// then consume it; if inedible, then return without consuming | |
433 | /// anything. Signal a fatal error if next token is unexpected. | |
9fa01778 XL |
434 | pub fn expect_one_of( |
435 | &mut self, | |
dc9dc135 XL |
436 | edible: &[TokenKind], |
437 | inedible: &[TokenKind], | |
9fa01778 | 438 | ) -> PResult<'a, bool /* recovered */> { |
dc9dc135 | 439 | if edible.contains(&self.token.kind) { |
9cc50fc6 | 440 | self.bump(); |
9fa01778 | 441 | Ok(false) |
dc9dc135 | 442 | } else if inedible.contains(&self.token.kind) { |
1a4d82fc | 443 | // leave it in the input |
9fa01778 | 444 | Ok(false) |
dc9dc135 | 445 | } else if self.last_unexpected_token_span == Some(self.token.span) { |
9fa01778 | 446 | FatalError.raise(); |
1a4d82fc | 447 | } else { |
dc9dc135 | 448 | self.expected_one_of_not_found(edible, inedible) |
1a4d82fc | 449 | } |
970d7e83 LB |
450 | } |
451 | ||
dfeec247 | 452 | // Public for rustfmt usage. |
f9f354fc | 453 | pub fn parse_ident(&mut self) -> PResult<'a, Ident> { |
2c00a5a8 XL |
454 | self.parse_ident_common(true) |
455 | } | |
456 | ||
f9f354fc | 457 | fn parse_ident_common(&mut self, recover: bool) -> PResult<'a, Ident> { |
74b04a01 XL |
458 | match self.token.ident() { |
459 | Some((ident, is_raw)) => { | |
460 | if !is_raw && ident.is_reserved() { | |
2c00a5a8 XL |
461 | let mut err = self.expected_ident_found(); |
462 | if recover { | |
463 | err.emit(); | |
464 | } else { | |
465 | return Err(err); | |
466 | } | |
041b39d2 | 467 | } |
9cc50fc6 | 468 | self.bump(); |
74b04a01 | 469 | Ok(ident) |
970d7e83 | 470 | } |
74b04a01 XL |
471 | _ => Err(match self.prev_token.kind { |
472 | TokenKind::DocComment(..) => { | |
473 | self.span_fatal_err(self.prev_token.span, Error::UselessDocComment) | |
474 | } | |
475 | _ => self.expected_ident_found(), | |
dfeec247 | 476 | }), |
970d7e83 LB |
477 | } |
478 | } | |
479 | ||
9fa01778 | 480 | /// Checks if the next token is `tok`, and returns `true` if so. |
1a4d82fc | 481 | /// |
7453a54e | 482 | /// This method will automatically add `tok` to `expected_tokens` if `tok` is not |
1a4d82fc | 483 | /// encountered. |
e74abb32 | 484 | fn check(&mut self, tok: &TokenKind) -> bool { |
1a4d82fc | 485 | let is_present = self.token == *tok; |
dfeec247 XL |
486 | if !is_present { |
487 | self.expected_tokens.push(TokenType::Token(tok.clone())); | |
488 | } | |
1a4d82fc | 489 | is_present |
970d7e83 LB |
490 | } |
491 | ||
9fa01778 | 492 | /// Consumes a token 'tok' if it exists. Returns whether the given token was present. |
dc9dc135 | 493 | pub fn eat(&mut self, tok: &TokenKind) -> bool { |
1a4d82fc | 494 | let is_present = self.check(tok); |
dfeec247 XL |
495 | if is_present { |
496 | self.bump() | |
497 | } | |
9cc50fc6 | 498 | is_present |
970d7e83 LB |
499 | } |
500 | ||
e74abb32 XL |
501 | /// If the next token is the given keyword, returns `true` without eating it. |
502 | /// An expectation is also added for diagnostics purposes. | |
dc9dc135 | 503 | fn check_keyword(&mut self, kw: Symbol) -> bool { |
85aaf69f SL |
504 | self.expected_tokens.push(TokenType::Keyword(kw)); |
505 | self.token.is_keyword(kw) | |
506 | } | |
507 | ||
e74abb32 XL |
508 | /// If the next token is the given keyword, eats it and returns `true`. |
509 | /// Otherwise, returns `false`. An expectation is also added for diagnostics purposes. | |
dfeec247 XL |
510 | // Public for rustfmt usage. |
511 | pub fn eat_keyword(&mut self, kw: Symbol) -> bool { | |
85aaf69f | 512 | if self.check_keyword(kw) { |
9cc50fc6 SL |
513 | self.bump(); |
514 | true | |
85aaf69f | 515 | } else { |
9cc50fc6 | 516 | false |
85aaf69f SL |
517 | } |
518 | } | |
519 | ||
dc9dc135 | 520 | fn eat_keyword_noexpect(&mut self, kw: Symbol) -> bool { |
1a4d82fc | 521 | if self.token.is_keyword(kw) { |
9cc50fc6 SL |
522 | self.bump(); |
523 | true | |
1a4d82fc | 524 | } else { |
9cc50fc6 | 525 | false |
1a4d82fc | 526 | } |
970d7e83 LB |
527 | } |
528 | ||
9fa01778 XL |
529 | /// If the given word is not a keyword, signals an error. |
530 | /// If the next token is not the given word, signals an error. | |
531 | /// Otherwise, eats it. | |
dc9dc135 | 532 | fn expect_keyword(&mut self, kw: Symbol) -> PResult<'a, ()> { |
dfeec247 | 533 | if !self.eat_keyword(kw) { self.unexpected() } else { Ok(()) } |
970d7e83 LB |
534 | } |
535 | ||
74b04a01 XL |
536 | /// Is the given keyword `kw` followed by a non-reserved identifier? |
537 | fn is_kw_followed_by_ident(&self, kw: Symbol) -> bool { | |
538 | self.token.is_keyword(kw) && self.look_ahead(1, |t| t.is_ident() && !t.is_reserved_ident()) | |
539 | } | |
540 | ||
e74abb32 XL |
541 | fn check_or_expected(&mut self, ok: bool, typ: TokenType) -> bool { |
542 | if ok { | |
32a655c1 SL |
543 | true |
544 | } else { | |
e74abb32 | 545 | self.expected_tokens.push(typ); |
32a655c1 SL |
546 | false |
547 | } | |
548 | } | |
549 | ||
e74abb32 XL |
550 | fn check_ident(&mut self) -> bool { |
551 | self.check_or_expected(self.token.is_ident(), TokenType::Ident) | |
552 | } | |
553 | ||
32a655c1 | 554 | fn check_path(&mut self) -> bool { |
e74abb32 | 555 | self.check_or_expected(self.token.is_path_start(), TokenType::Path) |
32a655c1 SL |
556 | } |
557 | ||
558 | fn check_type(&mut self) -> bool { | |
e74abb32 | 559 | self.check_or_expected(self.token.can_begin_type(), TokenType::Type) |
32a655c1 SL |
560 | } |
561 | ||
9fa01778 | 562 | fn check_const_arg(&mut self) -> bool { |
e74abb32 XL |
563 | self.check_or_expected(self.token.can_begin_const_arg(), TokenType::Const) |
564 | } | |
565 | ||
29967ef6 XL |
566 | fn check_inline_const(&self, dist: usize) -> bool { |
567 | self.is_keyword_ahead(dist, &[kw::Const]) | |
568 | && self.look_ahead(dist + 1, |t| match t.kind { | |
569 | token::Interpolated(ref nt) => matches!(**nt, token::NtBlock(..)), | |
570 | token::OpenDelim(DelimToken::Brace) => true, | |
571 | _ => false, | |
572 | }) | |
573 | } | |
574 | ||
e74abb32 XL |
575 | /// Checks to see if the next token is either `+` or `+=`. |
576 | /// Otherwise returns `false`. | |
577 | fn check_plus(&mut self) -> bool { | |
578 | self.check_or_expected( | |
579 | self.token.is_like_plus(), | |
580 | TokenType::Token(token::BinOp(token::Plus)), | |
581 | ) | |
9fa01778 XL |
582 | } |
583 | ||
74b04a01 XL |
584 | /// Eats the expected token if it's present possibly breaking |
585 | /// compound tokens like multi-character operators in process. | |
586 | /// Returns `true` if the token was eaten. | |
587 | fn break_and_eat(&mut self, expected: TokenKind) -> bool { | |
588 | if self.token.kind == expected { | |
589 | self.bump(); | |
590 | return true; | |
591 | } | |
592 | match self.token.kind.break_two_token_op() { | |
593 | Some((first, second)) if first == expected => { | |
594 | let first_span = self.sess.source_map().start_point(self.token.span); | |
595 | let second_span = self.token.span.with_lo(first_span.hi()); | |
596 | self.token = Token::new(first, first_span); | |
fc512014 XL |
597 | // Keep track of this token - if we end token capturing now, |
598 | // we'll want to append this token to the captured stream. | |
599 | // | |
600 | // If we consume any additional tokens, then this token | |
601 | // is not needed (we'll capture the entire 'glued' token), | |
602 | // and `next_tok` will set this field to `None` | |
603 | self.token_cursor.append_unglued_token = | |
604 | Some((TokenTree::Token(self.token.clone()), Spacing::Alone)); | |
29967ef6 XL |
605 | // Use the spacing of the glued token as the spacing |
606 | // of the unglued second token. | |
607 | self.bump_with((Token::new(second, second_span), self.token_spacing)); | |
94b46f34 XL |
608 | true |
609 | } | |
74b04a01 XL |
610 | _ => { |
611 | self.expected_tokens.push(TokenType::Token(expected)); | |
612 | false | |
94b46f34 | 613 | } |
94b46f34 XL |
614 | } |
615 | } | |
616 | ||
74b04a01 XL |
617 | /// Eats `+` possibly breaking tokens like `+=` in process. |
618 | fn eat_plus(&mut self) -> bool { | |
619 | self.break_and_eat(token::BinOp(token::Plus)) | |
620 | } | |
621 | ||
622 | /// Eats `&` possibly breaking tokens like `&&` in process. | |
623 | /// Signals an error if `&` is not eaten. | |
9cc50fc6 | 624 | fn expect_and(&mut self) -> PResult<'a, ()> { |
74b04a01 | 625 | if self.break_and_eat(token::BinOp(token::And)) { Ok(()) } else { self.unexpected() } |
ea8adc8c XL |
626 | } |
627 | ||
74b04a01 XL |
628 | /// Eats `|` possibly breaking tokens like `||` in process. |
629 | /// Signals an error if `|` was not eaten. | |
ea8adc8c | 630 | fn expect_or(&mut self) -> PResult<'a, ()> { |
74b04a01 | 631 | if self.break_and_eat(token::BinOp(token::Or)) { Ok(()) } else { self.unexpected() } |
970d7e83 LB |
632 | } |
633 | ||
74b04a01 | 634 | /// Eats `<` possibly breaking tokens like `<<` in process. |
9cc50fc6 | 635 | fn eat_lt(&mut self) -> bool { |
74b04a01 | 636 | let ate = self.break_and_eat(token::Lt); |
9fa01778 XL |
637 | if ate { |
638 | // See doc comment for `unmatched_angle_bracket_count`. | |
639 | self.unmatched_angle_bracket_count += 1; | |
640 | self.max_angle_bracket_count += 1; | |
641 | debug!("eat_lt: (increment) count={:?}", self.unmatched_angle_bracket_count); | |
1a4d82fc | 642 | } |
9fa01778 | 643 | ate |
1a4d82fc JJ |
644 | } |
645 | ||
74b04a01 XL |
646 | /// Eats `<` possibly breaking tokens like `<<` in process. |
647 | /// Signals an error if `<` was not eaten. | |
9cc50fc6 | 648 | fn expect_lt(&mut self) -> PResult<'a, ()> { |
74b04a01 | 649 | if self.eat_lt() { Ok(()) } else { self.unexpected() } |
1a4d82fc JJ |
650 | } |
651 | ||
74b04a01 XL |
652 | /// Eats `>` possibly breaking tokens like `>>` in process. |
653 | /// Signals an error if `>` was not eaten. | |
94b46f34 | 654 | fn expect_gt(&mut self) -> PResult<'a, ()> { |
74b04a01 XL |
655 | if self.break_and_eat(token::Gt) { |
656 | // See doc comment for `unmatched_angle_bracket_count`. | |
657 | if self.unmatched_angle_bracket_count > 0 { | |
658 | self.unmatched_angle_bracket_count -= 1; | |
659 | debug!("expect_gt: (decrement) count={:?}", self.unmatched_angle_bracket_count); | |
dfeec247 | 660 | } |
74b04a01 XL |
661 | Ok(()) |
662 | } else { | |
663 | self.unexpected() | |
1a4d82fc JJ |
664 | } |
665 | } | |
666 | ||
416331ca | 667 | fn expect_any_with_type(&mut self, kets: &[&TokenKind], expect: TokenExpectType) -> bool { |
dfeec247 XL |
668 | kets.iter().any(|k| match expect { |
669 | TokenExpectType::Expect => self.check(k), | |
670 | TokenExpectType::NoExpect => self.token == **k, | |
416331ca XL |
671 | }) |
672 | } | |
673 | ||
e74abb32 | 674 | fn parse_seq_to_before_tokens<T>( |
b7449926 | 675 | &mut self, |
dc9dc135 | 676 | kets: &[&TokenKind], |
b7449926 XL |
677 | sep: SeqSep, |
678 | expect: TokenExpectType, | |
416331ca XL |
679 | mut f: impl FnMut(&mut Parser<'a>) -> PResult<'a, T>, |
680 | ) -> PResult<'a, (Vec<T>, bool /* trailing */, bool /* recovered */)> { | |
9fa01778 XL |
681 | let mut first = true; |
682 | let mut recovered = false; | |
416331ca | 683 | let mut trailing = false; |
c30ab7b3 | 684 | let mut v = vec![]; |
416331ca XL |
685 | while !self.expect_any_with_type(kets, expect) { |
686 | if let token::CloseDelim(..) | token::Eof = self.token.kind { | |
dfeec247 | 687 | break; |
416331ca | 688 | } |
7cac9316 XL |
689 | if let Some(ref t) = sep.sep { |
690 | if first { | |
691 | first = false; | |
692 | } else { | |
9fa01778 XL |
693 | match self.expect(t) { |
694 | Ok(false) => {} | |
695 | Ok(true) => { | |
696 | recovered = true; | |
697 | break; | |
abe05a73 | 698 | } |
60c5eb7d | 699 | Err(mut expect_err) => { |
74b04a01 | 700 | let sp = self.prev_token.span.shrink_to_hi(); |
60c5eb7d XL |
701 | let token_str = pprust::token_kind_to_string(t); |
702 | ||
e1599b0c | 703 | // Attempt to keep parsing if it was a similar separator. |
9fa01778 | 704 | if let Some(ref tokens) = t.similar_tokens() { |
dc9dc135 | 705 | if tokens.contains(&self.token.kind) { |
9fa01778 XL |
706 | self.bump(); |
707 | } | |
708 | } | |
60c5eb7d | 709 | |
f9f354fc XL |
710 | // If this was a missing `@` in a binding pattern |
711 | // bail with a suggestion | |
712 | // https://github.com/rust-lang/rust/issues/72373 | |
f035d41b | 713 | if self.prev_token.is_ident() && self.token.kind == token::DotDot { |
f9f354fc XL |
714 | let msg = format!( |
715 | "if you meant to bind the contents of \ | |
716 | the rest of the array pattern into `{}`, use `@`", | |
717 | pprust::token_to_string(&self.prev_token) | |
718 | ); | |
719 | expect_err | |
720 | .span_suggestion_verbose( | |
721 | self.prev_token.span.shrink_to_hi().until(self.token.span), | |
722 | &msg, | |
723 | " @ ".to_string(), | |
724 | Applicability::MaybeIncorrect, | |
725 | ) | |
726 | .emit(); | |
727 | break; | |
728 | } | |
729 | ||
e1599b0c | 730 | // Attempt to keep parsing if it was an omitted separator. |
9fa01778 XL |
731 | match f(self) { |
732 | Ok(t) => { | |
60c5eb7d XL |
733 | // Parsed successfully, therefore most probably the code only |
734 | // misses a separator. | |
735 | expect_err | |
736 | .span_suggestion_short( | |
5869c6ff | 737 | sp, |
60c5eb7d XL |
738 | &format!("missing `{}`", token_str), |
739 | token_str, | |
740 | Applicability::MaybeIncorrect, | |
741 | ) | |
742 | .emit(); | |
743 | ||
9fa01778 XL |
744 | v.push(t); |
745 | continue; | |
dfeec247 | 746 | } |
9fa01778 | 747 | Err(mut e) => { |
60c5eb7d XL |
748 | // Parsing failed, therefore it must be something more serious |
749 | // than just a missing separator. | |
750 | expect_err.emit(); | |
751 | ||
9fa01778 XL |
752 | e.cancel(); |
753 | break; | |
754 | } | |
abe05a73 XL |
755 | } |
756 | } | |
7453a54e SL |
757 | } |
758 | } | |
7453a54e | 759 | } |
416331ca XL |
760 | if sep.trailing_sep_allowed && self.expect_any_with_type(kets, expect) { |
761 | trailing = true; | |
7453a54e SL |
762 | break; |
763 | } | |
764 | ||
abe05a73 XL |
765 | let t = f(self)?; |
766 | v.push(t); | |
970d7e83 | 767 | } |
7453a54e | 768 | |
416331ca | 769 | Ok((v, trailing, recovered)) |
970d7e83 LB |
770 | } |
771 | ||
dfeec247 XL |
772 | /// Parses a sequence, not including the closing delimiter. The function |
773 | /// `f` must consume tokens until reaching the next separator or | |
774 | /// closing bracket. | |
775 | fn parse_seq_to_before_end<T>( | |
776 | &mut self, | |
777 | ket: &TokenKind, | |
778 | sep: SeqSep, | |
779 | f: impl FnMut(&mut Parser<'a>) -> PResult<'a, T>, | |
780 | ) -> PResult<'a, (Vec<T>, bool, bool)> { | |
781 | self.parse_seq_to_before_tokens(&[ket], sep, TokenExpectType::Expect, f) | |
782 | } | |
783 | ||
784 | /// Parses a sequence, including the closing delimiter. The function | |
785 | /// `f` must consume tokens until reaching the next separator or | |
786 | /// closing bracket. | |
787 | fn parse_seq_to_end<T>( | |
788 | &mut self, | |
789 | ket: &TokenKind, | |
790 | sep: SeqSep, | |
791 | f: impl FnMut(&mut Parser<'a>) -> PResult<'a, T>, | |
792 | ) -> PResult<'a, (Vec<T>, bool /* trailing */)> { | |
793 | let (val, trailing, recovered) = self.parse_seq_to_before_end(ket, sep, f)?; | |
794 | if !recovered { | |
795 | self.eat(ket); | |
796 | } | |
797 | Ok((val, trailing)) | |
798 | } | |
799 | ||
9fa01778 XL |
800 | /// Parses a sequence, including the closing delimiter. The function |
801 | /// `f` must consume tokens until reaching the next separator or | |
1a4d82fc | 802 | /// closing bracket. |
416331ca | 803 | fn parse_unspanned_seq<T>( |
9fa01778 | 804 | &mut self, |
dc9dc135 XL |
805 | bra: &TokenKind, |
806 | ket: &TokenKind, | |
9fa01778 | 807 | sep: SeqSep, |
416331ca XL |
808 | f: impl FnMut(&mut Parser<'a>) -> PResult<'a, T>, |
809 | ) -> PResult<'a, (Vec<T>, bool)> { | |
54a0048b | 810 | self.expect(bra)?; |
dfeec247 | 811 | self.parse_seq_to_end(ket, sep, f) |
416331ca XL |
812 | } |
813 | ||
814 | fn parse_delim_comma_seq<T>( | |
815 | &mut self, | |
816 | delim: DelimToken, | |
817 | f: impl FnMut(&mut Parser<'a>) -> PResult<'a, T>, | |
818 | ) -> PResult<'a, (Vec<T>, bool)> { | |
819 | self.parse_unspanned_seq( | |
820 | &token::OpenDelim(delim), | |
821 | &token::CloseDelim(delim), | |
822 | SeqSep::trailing_allowed(token::Comma), | |
823 | f, | |
824 | ) | |
825 | } | |
826 | ||
827 | fn parse_paren_comma_seq<T>( | |
828 | &mut self, | |
829 | f: impl FnMut(&mut Parser<'a>) -> PResult<'a, T>, | |
830 | ) -> PResult<'a, (Vec<T>, bool)> { | |
831 | self.parse_delim_comma_seq(token::Paren, f) | |
970d7e83 LB |
832 | } |
833 | ||
74b04a01 | 834 | /// Advance the parser by one token using provided token as the next one. |
29967ef6 | 835 | fn bump_with(&mut self, (next_token, next_spacing): (Token, Spacing)) { |
74b04a01 XL |
836 | // Bumping after EOF is a bad sign, usually an infinite loop. |
837 | if self.prev_token.kind == TokenKind::Eof { | |
dfeec247 XL |
838 | let msg = "attempted to bump the parser past EOF (may be stuck in a loop)"; |
839 | self.span_bug(self.token.span, msg); | |
7453a54e SL |
840 | } |
841 | ||
74b04a01 XL |
842 | // Update the current and previous tokens. |
843 | self.prev_token = mem::replace(&mut self.token, next_token); | |
29967ef6 | 844 | self.token_spacing = next_spacing; |
9e0c209e | 845 | |
74b04a01 | 846 | // Diagnostics. |
7453a54e | 847 | self.expected_tokens.clear(); |
223e47cc | 848 | } |
7453a54e | 849 | |
74b04a01 XL |
850 | /// Advance the parser by one token. |
851 | pub fn bump(&mut self) { | |
852 | let next_token = self.next_tok(self.token.span); | |
853 | self.bump_with(next_token); | |
854 | } | |
855 | ||
e74abb32 XL |
856 | /// Look-ahead `dist` tokens of `self.token` and get access to that token there. |
857 | /// When `dist == 0` then the current token is looked at. | |
858 | pub fn look_ahead<R>(&self, dist: usize, looker: impl FnOnce(&Token) -> R) -> R { | |
c30ab7b3 | 859 | if dist == 0 { |
e74abb32 | 860 | return looker(&self.token); |
223e47cc | 861 | } |
8bb4bdeb | 862 | |
dc9dc135 | 863 | let frame = &self.token_cursor.frame; |
29967ef6 | 864 | match frame.tree_cursor.look_ahead(dist - 1) { |
8bb4bdeb | 865 | Some(tree) => match tree { |
29967ef6 | 866 | TokenTree::Token(token) => looker(token), |
dfeec247 | 867 | TokenTree::Delimited(dspan, delim, _) => { |
29967ef6 | 868 | looker(&Token::new(token::OpenDelim(*delim), dspan.open)) |
dfeec247 XL |
869 | } |
870 | }, | |
29967ef6 XL |
871 | None => looker(&Token::new(token::CloseDelim(frame.delim), frame.span.close)), |
872 | } | |
223e47cc | 873 | } |
ff7c6d11 | 874 | |
dc9dc135 XL |
875 | /// Returns whether any of the given keywords are `dist` tokens ahead of the current one. |
876 | fn is_keyword_ahead(&self, dist: usize, kws: &[Symbol]) -> bool { | |
877 | self.look_ahead(dist, |t| kws.iter().any(|&kw| t.is_keyword(kw))) | |
223e47cc | 878 | } |
223e47cc | 879 | |
9fa01778 | 880 | /// Parses asyncness: `async` or nothing. |
74b04a01 | 881 | fn parse_asyncness(&mut self) -> Async { |
dc9dc135 | 882 | if self.eat_keyword(kw::Async) { |
74b04a01 XL |
883 | let span = self.prev_token.uninterpolated_span(); |
884 | Async::Yes { span, closure_id: DUMMY_NODE_ID, return_impl_trait_id: DUMMY_NODE_ID } | |
8faf50e0 | 885 | } else { |
74b04a01 | 886 | Async::No |
8faf50e0 XL |
887 | } |
888 | } | |
889 | ||
9fa01778 | 890 | /// Parses unsafety: `unsafe` or nothing. |
74b04a01 XL |
891 | fn parse_unsafety(&mut self) -> Unsafe { |
892 | if self.eat_keyword(kw::Unsafe) { | |
893 | Unsafe::Yes(self.prev_token.uninterpolated_span()) | |
894 | } else { | |
895 | Unsafe::No | |
896 | } | |
897 | } | |
898 | ||
899 | /// Parses constness: `const` or nothing. | |
900 | fn parse_constness(&mut self) -> Const { | |
29967ef6 XL |
901 | // Avoid const blocks to be parsed as const items |
902 | if self.look_ahead(1, |t| t != &token::OpenDelim(DelimToken::Brace)) | |
903 | && self.eat_keyword(kw::Const) | |
904 | { | |
74b04a01 XL |
905 | Const::Yes(self.prev_token.uninterpolated_span()) |
906 | } else { | |
907 | Const::No | |
908 | } | |
1a4d82fc JJ |
909 | } |
910 | ||
29967ef6 XL |
911 | /// Parses inline const expressions. |
912 | fn parse_const_block(&mut self, span: Span) -> PResult<'a, P<Expr>> { | |
913 | self.sess.gated_spans.gate(sym::inline_const, span); | |
914 | self.eat_keyword(kw::Const); | |
915 | let blk = self.parse_block()?; | |
916 | let anon_const = AnonConst { | |
917 | id: DUMMY_NODE_ID, | |
918 | value: self.mk_expr(blk.span, ExprKind::Block(blk, None), AttrVec::new()), | |
919 | }; | |
fc512014 XL |
920 | let blk_span = anon_const.value.span; |
921 | Ok(self.mk_expr(span.to(blk_span), ExprKind::ConstBlock(anon_const), AttrVec::new())) | |
29967ef6 XL |
922 | } |
923 | ||
416331ca XL |
924 | /// Parses mutability (`mut` or nothing). |
925 | fn parse_mutability(&mut self) -> Mutability { | |
dfeec247 | 926 | if self.eat_keyword(kw::Mut) { Mutability::Mut } else { Mutability::Not } |
223e47cc LB |
927 | } |
928 | ||
e74abb32 XL |
929 | /// Possibly parses mutability (`const` or `mut`). |
930 | fn parse_const_or_mut(&mut self) -> Option<Mutability> { | |
931 | if self.eat_keyword(kw::Mut) { | |
dfeec247 | 932 | Some(Mutability::Mut) |
e74abb32 | 933 | } else if self.eat_keyword(kw::Const) { |
dfeec247 | 934 | Some(Mutability::Not) |
e74abb32 XL |
935 | } else { |
936 | None | |
937 | } | |
938 | } | |
939 | ||
416331ca | 940 | fn parse_field_name(&mut self) -> PResult<'a, Ident> { |
dfeec247 XL |
941 | if let token::Literal(token::Lit { kind: token::Integer, symbol, suffix }) = self.token.kind |
942 | { | |
416331ca XL |
943 | self.expect_no_suffix(self.token.span, "a tuple index", suffix); |
944 | self.bump(); | |
74b04a01 | 945 | Ok(Ident::new(symbol, self.prev_token.span)) |
223e47cc | 946 | } else { |
416331ca | 947 | self.parse_ident_common(false) |
223e47cc LB |
948 | } |
949 | } | |
950 | ||
60c5eb7d XL |
951 | fn parse_mac_args(&mut self) -> PResult<'a, P<MacArgs>> { |
952 | self.parse_mac_args_common(true).map(P) | |
953 | } | |
954 | ||
955 | fn parse_attr_args(&mut self) -> PResult<'a, MacArgs> { | |
956 | self.parse_mac_args_common(false) | |
957 | } | |
958 | ||
959 | fn parse_mac_args_common(&mut self, delimited_only: bool) -> PResult<'a, MacArgs> { | |
dfeec247 XL |
960 | Ok( |
961 | if self.check(&token::OpenDelim(DelimToken::Paren)) | |
962 | || self.check(&token::OpenDelim(DelimToken::Bracket)) | |
963 | || self.check(&token::OpenDelim(DelimToken::Brace)) | |
964 | { | |
965 | match self.parse_token_tree() { | |
966 | TokenTree::Delimited(dspan, delim, tokens) => | |
60c5eb7d | 967 | // We've confirmed above that there is a delimiter so unwrapping is OK. |
dfeec247 XL |
968 | { |
969 | MacArgs::Delimited(dspan, MacDelimiter::from_token(delim).unwrap(), tokens) | |
60c5eb7d | 970 | } |
dfeec247 | 971 | _ => unreachable!(), |
60c5eb7d | 972 | } |
dfeec247 XL |
973 | } else if !delimited_only { |
974 | if self.eat(&token::Eq) { | |
74b04a01 | 975 | let eq_span = self.prev_token.span; |
dfeec247 XL |
976 | let mut is_interpolated_expr = false; |
977 | if let token::Interpolated(nt) = &self.token.kind { | |
978 | if let token::NtExpr(..) = **nt { | |
979 | is_interpolated_expr = true; | |
980 | } | |
981 | } | |
60c5eb7d | 982 | |
5869c6ff XL |
983 | // Collect tokens because they are used during lowering to HIR. |
984 | let expr = self.collect_tokens(|this| this.parse_expr())?; | |
fc512014 XL |
985 | let span = expr.span; |
986 | ||
987 | match &expr.kind { | |
988 | // Not gated to supporte things like `doc = $expr` that work on stable. | |
989 | _ if is_interpolated_expr => {} | |
990 | ExprKind::Lit(lit) if lit.kind.is_unsuffixed() => {} | |
991 | _ => self.sess.gated_spans.gate(sym::extended_key_value_attributes, span), | |
992 | } | |
993 | ||
5869c6ff XL |
994 | let token_kind = token::Interpolated(Lrc::new(token::NtExpr(expr))); |
995 | MacArgs::Eq(eq_span, Token::new(token_kind, span)) | |
dfeec247 XL |
996 | } else { |
997 | MacArgs::Empty | |
998 | } | |
60c5eb7d | 999 | } else { |
dfeec247 XL |
1000 | return self.unexpected(); |
1001 | }, | |
1002 | ) | |
416331ca | 1003 | } |
041b39d2 | 1004 | |
e74abb32 XL |
1005 | fn parse_or_use_outer_attributes( |
1006 | &mut self, | |
dfeec247 XL |
1007 | already_parsed_attrs: Option<AttrVec>, |
1008 | ) -> PResult<'a, AttrVec> { | |
416331ca XL |
1009 | if let Some(attrs) = already_parsed_attrs { |
1010 | Ok(attrs) | |
970d7e83 | 1011 | } else { |
416331ca | 1012 | self.parse_outer_attributes().map(|a| a.into()) |
970d7e83 LB |
1013 | } |
1014 | } | |
1015 | ||
416331ca | 1016 | /// Parses a single token tree from the input. |
3dfed10e | 1017 | pub(crate) fn parse_token_tree(&mut self) -> TokenTree { |
dc9dc135 | 1018 | match self.token.kind { |
416331ca | 1019 | token::OpenDelim(..) => { |
29967ef6 XL |
1020 | let depth = self.token_cursor.stack.len(); |
1021 | ||
1022 | // We keep advancing the token cursor until we hit | |
1023 | // the matching `CloseDelim` token. | |
1024 | while !(depth == self.token_cursor.stack.len() | |
1025 | && matches!(self.token.kind, token::CloseDelim(_))) | |
1026 | { | |
1027 | // Advance one token at a time, so `TokenCursor::next()` | |
1028 | // can capture these tokens if necessary. | |
1029 | self.bump(); | |
1030 | } | |
1031 | // We are still inside the frame corresponding | |
1032 | // to the delimited stream we captured, so grab | |
1033 | // the tokens from this frame. | |
1034 | let frame = &self.token_cursor.frame; | |
1035 | let stream = frame.tree_cursor.stream.clone(); | |
1036 | let span = frame.span; | |
1037 | let delim = frame.delim; | |
1038 | // Consume close delimiter | |
0731742a | 1039 | self.bump(); |
29967ef6 | 1040 | TokenTree::Delimited(span, delim, stream) |
dfeec247 | 1041 | } |
416331ca XL |
1042 | token::CloseDelim(_) | token::Eof => unreachable!(), |
1043 | _ => { | |
416331ca | 1044 | self.bump(); |
74b04a01 | 1045 | TokenTree::Token(self.prev_token.clone()) |
0731742a | 1046 | } |
0731742a XL |
1047 | } |
1048 | } | |
1049 | ||
416331ca XL |
1050 | /// Parses a stream of tokens into a list of `TokenTree`s, up to EOF. |
1051 | pub fn parse_all_token_trees(&mut self) -> PResult<'a, Vec<TokenTree>> { | |
1052 | let mut tts = Vec::new(); | |
1053 | while self.token != token::Eof { | |
1054 | tts.push(self.parse_token_tree()); | |
54a0048b | 1055 | } |
416331ca | 1056 | Ok(tts) |
54a0048b SL |
1057 | } |
1058 | ||
416331ca XL |
1059 | pub fn parse_tokens(&mut self) -> TokenStream { |
1060 | let mut result = Vec::new(); | |
1061 | loop { | |
1062 | match self.token.kind { | |
1063 | token::Eof | token::CloseDelim(..) => break, | |
1064 | _ => result.push(self.parse_token_tree().into()), | |
ff7c6d11 | 1065 | } |
223e47cc | 1066 | } |
416331ca | 1067 | TokenStream::new(result) |
223e47cc LB |
1068 | } |
1069 | ||
416331ca XL |
1070 | /// Evaluates the closure with restrictions in place. |
1071 | /// | |
1072 | /// Afters the closure is evaluated, restrictions are reset. | |
e74abb32 | 1073 | fn with_res<T>(&mut self, res: Restrictions, f: impl FnOnce(&mut Self) -> T) -> T { |
416331ca | 1074 | let old = self.restrictions; |
e74abb32 XL |
1075 | self.restrictions = res; |
1076 | let res = f(self); | |
416331ca | 1077 | self.restrictions = old; |
e74abb32 | 1078 | res |
8faf50e0 XL |
1079 | } |
1080 | ||
416331ca XL |
1081 | fn is_crate_vis(&self) -> bool { |
1082 | self.token.is_keyword(kw::Crate) && self.look_ahead(1, |t| t != &token::ModSep) | |
223e47cc LB |
1083 | } |
1084 | ||
416331ca XL |
1085 | /// Parses `pub`, `pub(crate)` and `pub(in path)` plus shortcuts `crate` for `pub(crate)`, |
1086 | /// `pub(self)` for `pub(in self)` and `pub(super)` for `pub(in super)`. | |
1087 | /// If the following element can't be a tuple (i.e., it's a function definition), then | |
1088 | /// it's not a tuple struct field), and the contents within the parentheses isn't valid, | |
1089 | /// so emit a proper diagnostic. | |
1b1a35ee XL |
1090 | // Public for rustfmt usage. |
1091 | pub fn parse_visibility(&mut self, fbt: FollowedByType) -> PResult<'a, Visibility> { | |
416331ca | 1092 | maybe_whole!(self, NtVis, |x| x); |
dc9dc135 | 1093 | |
416331ca XL |
1094 | self.expected_tokens.push(TokenType::Keyword(kw::Crate)); |
1095 | if self.is_crate_vis() { | |
1096 | self.bump(); // `crate` | |
74b04a01 | 1097 | self.sess.gated_spans.gate(sym::crate_visibility_modifier, self.prev_token.span); |
1b1a35ee XL |
1098 | return Ok(Visibility { |
1099 | span: self.prev_token.span, | |
1100 | kind: VisibilityKind::Crate(CrateSugar::JustCrate), | |
1101 | tokens: None, | |
1102 | }); | |
416331ca | 1103 | } |
223e47cc | 1104 | |
416331ca XL |
1105 | if !self.eat_keyword(kw::Pub) { |
1106 | // We need a span for our `Spanned<VisibilityKind>`, but there's inherently no | |
1107 | // keyword to grab a span from for inherited visibility; an empty span at the | |
1108 | // beginning of the current token would seem to be the "Schelling span". | |
1b1a35ee XL |
1109 | return Ok(Visibility { |
1110 | span: self.token.span.shrink_to_lo(), | |
1111 | kind: VisibilityKind::Inherited, | |
1112 | tokens: None, | |
1113 | }); | |
416331ca | 1114 | } |
74b04a01 | 1115 | let lo = self.prev_token.span; |
223e47cc | 1116 | |
416331ca XL |
1117 | if self.check(&token::OpenDelim(token::Paren)) { |
1118 | // We don't `self.bump()` the `(` yet because this might be a struct definition where | |
1119 | // `()` or a tuple might be allowed. For example, `struct Struct(pub (), pub (usize));`. | |
1120 | // Because of this, we only `bump` the `(` if we're assured it is appropriate to do so | |
1121 | // by the following tokens. | |
dfeec247 XL |
1122 | if self.is_keyword_ahead(1, &[kw::Crate]) && self.look_ahead(2, |t| t != &token::ModSep) |
1123 | // account for `pub(crate::foo)` | |
416331ca | 1124 | { |
e74abb32 | 1125 | // Parse `pub(crate)`. |
416331ca XL |
1126 | self.bump(); // `(` |
1127 | self.bump(); // `crate` | |
1128 | self.expect(&token::CloseDelim(token::Paren))?; // `)` | |
e74abb32 | 1129 | let vis = VisibilityKind::Crate(CrateSugar::PubCrate); |
1b1a35ee XL |
1130 | return Ok(Visibility { |
1131 | span: lo.to(self.prev_token.span), | |
1132 | kind: vis, | |
1133 | tokens: None, | |
1134 | }); | |
416331ca | 1135 | } else if self.is_keyword_ahead(1, &[kw::In]) { |
e74abb32 | 1136 | // Parse `pub(in path)`. |
416331ca XL |
1137 | self.bump(); // `(` |
1138 | self.bump(); // `in` | |
1139 | let path = self.parse_path(PathStyle::Mod)?; // `path` | |
1140 | self.expect(&token::CloseDelim(token::Paren))?; // `)` | |
dfeec247 | 1141 | let vis = VisibilityKind::Restricted { path: P(path), id: ast::DUMMY_NODE_ID }; |
1b1a35ee XL |
1142 | return Ok(Visibility { |
1143 | span: lo.to(self.prev_token.span), | |
1144 | kind: vis, | |
1145 | tokens: None, | |
1146 | }); | |
e74abb32 XL |
1147 | } else if self.look_ahead(2, |t| t == &token::CloseDelim(token::Paren)) |
1148 | && self.is_keyword_ahead(1, &[kw::Super, kw::SelfLower]) | |
416331ca | 1149 | { |
e74abb32 | 1150 | // Parse `pub(self)` or `pub(super)`. |
416331ca XL |
1151 | self.bump(); // `(` |
1152 | let path = self.parse_path(PathStyle::Mod)?; // `super`/`self` | |
1153 | self.expect(&token::CloseDelim(token::Paren))?; // `)` | |
dfeec247 | 1154 | let vis = VisibilityKind::Restricted { path: P(path), id: ast::DUMMY_NODE_ID }; |
1b1a35ee XL |
1155 | return Ok(Visibility { |
1156 | span: lo.to(self.prev_token.span), | |
1157 | kind: vis, | |
1158 | tokens: None, | |
1159 | }); | |
60c5eb7d XL |
1160 | } else if let FollowedByType::No = fbt { |
1161 | // Provide this diagnostic if a type cannot follow; | |
1162 | // in particular, if this is not a tuple struct. | |
e74abb32 XL |
1163 | self.recover_incorrect_vis_restriction()?; |
1164 | // Emit diagnostic, but continue with public visibility. | |
532ac7d7 | 1165 | } |
223e47cc | 1166 | } |
223e47cc | 1167 | |
1b1a35ee | 1168 | Ok(Visibility { span: lo, kind: VisibilityKind::Public, tokens: None }) |
223e47cc LB |
1169 | } |
1170 | ||
e74abb32 XL |
1171 | /// Recovery for e.g. `pub(something) fn ...` or `struct X { pub(something) y: Z }` |
1172 | fn recover_incorrect_vis_restriction(&mut self) -> PResult<'a, ()> { | |
1173 | self.bump(); // `(` | |
1174 | let path = self.parse_path(PathStyle::Mod)?; | |
dfeec247 | 1175 | self.expect(&token::CloseDelim(token::Paren))?; // `)` |
e74abb32 XL |
1176 | |
1177 | let msg = "incorrect visibility restriction"; | |
1178 | let suggestion = r##"some possible visibility restrictions are: | |
1179 | `pub(crate)`: visible only on the current crate | |
1180 | `pub(super)`: visible only in the current module's parent | |
1181 | `pub(in path::to::module)`: visible only on the specified path"##; | |
1182 | ||
1183 | let path_str = pprust::path_to_string(&path); | |
1184 | ||
1185 | struct_span_err!(self.sess.span_diagnostic, path.span, E0704, "{}", msg) | |
1186 | .help(suggestion) | |
1187 | .span_suggestion( | |
1188 | path.span, | |
1189 | &format!("make this visible only to module `{}` with `in`", path_str), | |
1190 | format!("in {}", path_str), | |
1191 | Applicability::MachineApplicable, | |
1192 | ) | |
1193 | .emit(); | |
1194 | ||
1195 | Ok(()) | |
1196 | } | |
1197 | ||
60c5eb7d XL |
1198 | /// Parses `extern string_literal?`. |
1199 | fn parse_extern(&mut self) -> PResult<'a, Extern> { | |
1200 | Ok(if self.eat_keyword(kw::Extern) { | |
1201 | Extern::from_abi(self.parse_abi()) | |
e74abb32 | 1202 | } else { |
60c5eb7d XL |
1203 | Extern::None |
1204 | }) | |
e74abb32 XL |
1205 | } |
1206 | ||
60c5eb7d XL |
1207 | /// Parses a string literal as an ABI spec. |
1208 | fn parse_abi(&mut self) -> Option<StrLit> { | |
1209 | match self.parse_str_lit() { | |
1210 | Ok(str_lit) => Some(str_lit), | |
1211 | Err(Some(lit)) => match lit.kind { | |
1212 | ast::LitKind::Err(_) => None, | |
1213 | _ => { | |
1214 | self.struct_span_err(lit.span, "non-string ABI literal") | |
1215 | .span_suggestion( | |
1216 | lit.span, | |
1217 | "specify the ABI with a string literal", | |
1218 | "\"C\"".to_string(), | |
1219 | Applicability::MaybeIncorrect, | |
1220 | ) | |
1221 | .emit(); | |
1222 | None | |
223e47cc | 1223 | } |
dfeec247 | 1224 | }, |
60c5eb7d | 1225 | Err(None) => None, |
223e47cc LB |
1226 | } |
1227 | } | |
1228 | ||
5869c6ff XL |
1229 | pub fn collect_tokens<R: HasTokens>( |
1230 | &mut self, | |
1231 | f: impl FnOnce(&mut Self) -> PResult<'a, R>, | |
1232 | ) -> PResult<'a, R> { | |
1233 | self.collect_tokens_trailing_token(|this| Ok((f(this)?, TrailingToken::None))) | |
1234 | } | |
1235 | ||
f9f354fc XL |
1236 | /// Records all tokens consumed by the provided callback, |
1237 | /// including the current token. These tokens are collected | |
29967ef6 | 1238 | /// into a `LazyTokenStream`, and returned along with the result |
fc512014 | 1239 | /// of the callback. |
f9f354fc XL |
1240 | /// |
1241 | /// Note: If your callback consumes an opening delimiter | |
1242 | /// (including the case where you call `collect_tokens` | |
1243 | /// when the current token is an opening delimeter), | |
1244 | /// you must also consume the corresponding closing delimiter. | |
1245 | /// | |
1246 | /// That is, you can consume | |
1247 | /// `something ([{ }])` or `([{}])`, but not `([{}]` | |
1248 | /// | |
1249 | /// This restriction shouldn't be an issue in practice, | |
1250 | /// since this function is used to record the tokens for | |
1251 | /// a parsed AST item, which always has matching delimiters. | |
5869c6ff | 1252 | pub fn collect_tokens_trailing_token<R: HasTokens>( |
e74abb32 | 1253 | &mut self, |
5869c6ff XL |
1254 | f: impl FnOnce(&mut Self) -> PResult<'a, (R, TrailingToken)>, |
1255 | ) -> PResult<'a, R> { | |
29967ef6 XL |
1256 | let start_token = (self.token.clone(), self.token_spacing); |
1257 | let cursor_snapshot = self.token_cursor.clone(); | |
f9f354fc | 1258 | |
5869c6ff | 1259 | let (mut ret, trailing_token) = f(self)?; |
f9f354fc | 1260 | |
29967ef6 XL |
1261 | // Produces a `TokenStream` on-demand. Using `cursor_snapshot` |
1262 | // and `num_calls`, we can reconstruct the `TokenStream` seen | |
1263 | // by the callback. This allows us to avoid producing a `TokenStream` | |
1264 | // if it is never needed - for example, a captured `macro_rules!` | |
1265 | // argument that is never passed to a proc macro. | |
fc512014 XL |
1266 | // In practice token stream creation happens rarely compared to |
1267 | // calls to `collect_tokens` (see some statistics in #78736), | |
1268 | // so we are doing as little up-front work as possible. | |
29967ef6 XL |
1269 | // |
1270 | // This also makes `Parser` very cheap to clone, since | |
1271 | // there is no intermediate collection buffer to clone. | |
fc512014 | 1272 | #[derive(Clone)] |
29967ef6 XL |
1273 | struct LazyTokenStreamImpl { |
1274 | start_token: (Token, Spacing), | |
1275 | cursor_snapshot: TokenCursor, | |
1276 | num_calls: usize, | |
1277 | desugar_doc_comments: bool, | |
fc512014 | 1278 | append_unglued_token: Option<TreeAndSpacing>, |
29967ef6 XL |
1279 | } |
1280 | impl CreateTokenStream for LazyTokenStreamImpl { | |
1281 | fn create_token_stream(&self) -> TokenStream { | |
1282 | // The token produced by the final call to `next` or `next_desugared` | |
1283 | // was not actually consumed by the callback. The combination | |
1284 | // of chaining the initial token and using `take` produces the desired | |
1285 | // result - we produce an empty `TokenStream` if no calls were made, | |
1286 | // and omit the final token otherwise. | |
1287 | let mut cursor_snapshot = self.cursor_snapshot.clone(); | |
1288 | let tokens = std::iter::once(self.start_token.clone()) | |
5869c6ff | 1289 | .chain((0..self.num_calls).map(|_| { |
29967ef6 XL |
1290 | if self.desugar_doc_comments { |
1291 | cursor_snapshot.next_desugared() | |
1292 | } else { | |
1293 | cursor_snapshot.next() | |
1294 | } | |
1295 | })) | |
5869c6ff | 1296 | .take(self.num_calls); |
29967ef6 | 1297 | |
fc512014 XL |
1298 | make_token_stream(tokens, self.append_unglued_token.clone()) |
1299 | } | |
5869c6ff XL |
1300 | } |
1301 | ||
1302 | let mut num_calls = self.token_cursor.num_next_calls - cursor_snapshot.num_next_calls; | |
1303 | match trailing_token { | |
1304 | TrailingToken::None => {} | |
1305 | TrailingToken::Semi => { | |
1306 | assert_eq!(self.token.kind, token::Semi); | |
1307 | num_calls += 1; | |
8faf50e0 | 1308 | } |
3b2f2976 XL |
1309 | } |
1310 | ||
29967ef6 XL |
1311 | let lazy_impl = LazyTokenStreamImpl { |
1312 | start_token, | |
5869c6ff | 1313 | num_calls, |
29967ef6 | 1314 | cursor_snapshot, |
29967ef6 | 1315 | desugar_doc_comments: self.desugar_doc_comments, |
fc512014 | 1316 | append_unglued_token: self.token_cursor.append_unglued_token.clone(), |
29967ef6 | 1317 | }; |
5869c6ff XL |
1318 | ret.finalize_tokens(LazyTokenStream::new(lazy_impl)); |
1319 | Ok(ret) | |
3b2f2976 XL |
1320 | } |
1321 | ||
0531ce1d XL |
1322 | /// `::{` or `::*` |
1323 | fn is_import_coupler(&mut self) -> bool { | |
dfeec247 XL |
1324 | self.check(&token::ModSep) |
1325 | && self.look_ahead(1, |t| { | |
1326 | *t == token::OpenDelim(token::Brace) || *t == token::BinOp(token::Star) | |
1327 | }) | |
a7813a04 | 1328 | } |
1b1a35ee XL |
1329 | |
1330 | pub fn clear_expected_tokens(&mut self) { | |
1331 | self.expected_tokens.clear(); | |
1332 | } | |
e74abb32 | 1333 | } |
532ac7d7 | 1334 | |
e74abb32 XL |
1335 | crate fn make_unclosed_delims_error( |
1336 | unmatched: UnmatchedBrace, | |
1337 | sess: &ParseSess, | |
1338 | ) -> Option<DiagnosticBuilder<'_>> { | |
1339 | // `None` here means an `Eof` was found. We already emit those errors elsewhere, we add them to | |
1340 | // `unmatched_braces` only for error recovery in the `Parser`. | |
1341 | let found_delim = unmatched.found_delim?; | |
dfeec247 XL |
1342 | let mut err = sess.span_diagnostic.struct_span_err( |
1343 | unmatched.found_span, | |
1344 | &format!( | |
1345 | "mismatched closing delimiter: `{}`", | |
1346 | pprust::token_kind_to_string(&token::CloseDelim(found_delim)), | |
1347 | ), | |
1348 | ); | |
1349 | err.span_label(unmatched.found_span, "mismatched closing delimiter"); | |
e74abb32 | 1350 | if let Some(sp) = unmatched.candidate_span { |
dfeec247 | 1351 | err.span_label(sp, "closing delimiter possibly meant for this"); |
e74abb32 XL |
1352 | } |
1353 | if let Some(sp) = unmatched.unclosed_span { | |
dfeec247 | 1354 | err.span_label(sp, "unclosed delimiter"); |
e74abb32 XL |
1355 | } |
1356 | Some(err) | |
223e47cc | 1357 | } |
9fa01778 | 1358 | |
e74abb32 | 1359 | pub fn emit_unclosed_delims(unclosed_delims: &mut Vec<UnmatchedBrace>, sess: &ParseSess) { |
dfeec247 XL |
1360 | *sess.reached_eof.borrow_mut() |= |
1361 | unclosed_delims.iter().any(|unmatched_delim| unmatched_delim.found_delim.is_none()); | |
e74abb32 | 1362 | for unmatched in unclosed_delims.drain(..) { |
f9f354fc | 1363 | if let Some(mut e) = make_unclosed_delims_error(unmatched, sess) { |
74b04a01 | 1364 | e.emit(); |
f9f354fc | 1365 | } |
9fa01778 | 1366 | } |
9fa01778 | 1367 | } |
29967ef6 XL |
1368 | |
1369 | /// Converts a flattened iterator of tokens (including open and close delimiter tokens) | |
1370 | /// into a `TokenStream`, creating a `TokenTree::Delimited` for each matching pair | |
1371 | /// of open and close delims. | |
fc512014 XL |
1372 | fn make_token_stream( |
1373 | tokens: impl Iterator<Item = (Token, Spacing)>, | |
1374 | append_unglued_token: Option<TreeAndSpacing>, | |
1375 | ) -> TokenStream { | |
29967ef6 XL |
1376 | #[derive(Debug)] |
1377 | struct FrameData { | |
1378 | open: Span, | |
1379 | inner: Vec<(TokenTree, Spacing)>, | |
1380 | } | |
1381 | let mut stack = vec![FrameData { open: DUMMY_SP, inner: vec![] }]; | |
1382 | for (token, spacing) in tokens { | |
1383 | match token { | |
1384 | Token { kind: TokenKind::OpenDelim(_), span } => { | |
1385 | stack.push(FrameData { open: span, inner: vec![] }); | |
1386 | } | |
1387 | Token { kind: TokenKind::CloseDelim(delim), span } => { | |
1388 | let frame_data = stack.pop().expect("Token stack was empty!"); | |
1389 | let dspan = DelimSpan::from_pair(frame_data.open, span); | |
1390 | let stream = TokenStream::new(frame_data.inner); | |
1391 | let delimited = TokenTree::Delimited(dspan, delim, stream); | |
1392 | stack | |
1393 | .last_mut() | |
1394 | .unwrap_or_else(|| panic!("Bottom token frame is missing for tokens!")) | |
1395 | .inner | |
1396 | .push((delimited, Spacing::Alone)); | |
1397 | } | |
fc512014 XL |
1398 | token => { |
1399 | stack | |
1400 | .last_mut() | |
1401 | .expect("Bottom token frame is missing!") | |
1402 | .inner | |
1403 | .push((TokenTree::Token(token), spacing)); | |
1404 | } | |
29967ef6 XL |
1405 | } |
1406 | } | |
fc512014 XL |
1407 | let mut final_buf = stack.pop().expect("Missing final buf!"); |
1408 | final_buf.inner.extend(append_unglued_token); | |
29967ef6 XL |
1409 | assert!(stack.is_empty(), "Stack should be empty: final_buf={:?} stack={:?}", final_buf, stack); |
1410 | TokenStream::new(final_buf.inner) | |
1411 | } | |
5869c6ff XL |
1412 | |
1413 | #[macro_export] | |
1414 | macro_rules! maybe_collect_tokens { | |
1415 | ($self:ident, $force_collect:expr, $attrs:expr, $f:expr) => { | |
1416 | if matches!($force_collect, ForceCollect::Yes) | |
1417 | || $crate::parser::attr::maybe_needs_tokens($attrs) | |
1418 | { | |
1419 | $self.collect_tokens_trailing_token($f) | |
1420 | } else { | |
1421 | Ok($f($self)?.0) | |
1422 | } | |
1423 | }; | |
1424 | } |