1386 lines
49 KiB
Rust
1386 lines
49 KiB
Rust
pub mod attr;
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mod expr;
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mod pat;
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mod item;
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mod module;
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mod ty;
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mod path;
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pub use path::PathStyle;
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mod stmt;
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mod generics;
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mod diagnostics;
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use diagnostics::Error;
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use crate::{Directory, DirectoryOwnership};
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use crate::lexer::UnmatchedBrace;
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use syntax::ast::{
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self, DUMMY_NODE_ID, AttrStyle, Attribute, CrateSugar, Extern, Ident, StrLit,
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IsAsync, MacDelimiter, Mutability, Visibility, VisibilityKind, Unsafety,
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};
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use syntax::print::pprust;
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use syntax::ptr::P;
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use syntax::token::{self, Token, TokenKind, DelimToken};
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use syntax::tokenstream::{self, DelimSpan, TokenTree, TokenStream, TreeAndJoint};
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use syntax::sess::ParseSess;
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use syntax::source_map::respan;
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use syntax::struct_span_err;
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use syntax::util::comments::{doc_comment_style, strip_doc_comment_decoration};
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use syntax_pos::symbol::{kw, sym, Symbol};
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use syntax_pos::{Span, BytePos, DUMMY_SP, FileName};
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use rustc_data_structures::thin_vec::ThinVec;
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use errors::{PResult, Applicability, DiagnosticBuilder, FatalError};
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use log::debug;
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use std::borrow::Cow;
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use std::{cmp, mem, slice};
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use std::path::PathBuf;
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use rustc_error_codes::*;
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bitflags::bitflags! {
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struct Restrictions: u8 {
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const STMT_EXPR = 1 << 0;
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const NO_STRUCT_LITERAL = 1 << 1;
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}
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}
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#[derive(Clone, Copy, PartialEq, Debug)]
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enum SemiColonMode {
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Break,
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Ignore,
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Comma,
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}
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#[derive(Clone, Copy, PartialEq, Debug)]
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enum BlockMode {
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Break,
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Ignore,
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}
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/// Like `maybe_whole_expr`, but for things other than expressions.
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#[macro_export]
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macro_rules! maybe_whole {
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($p:expr, $constructor:ident, |$x:ident| $e:expr) => {
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if let token::Interpolated(nt) = &$p.token.kind {
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if let token::$constructor(x) = &**nt {
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let $x = x.clone();
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$p.bump();
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return Ok($e);
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}
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}
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};
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}
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/// If the next tokens are ill-formed `$ty::` recover them as `<$ty>::`.
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#[macro_export]
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macro_rules! maybe_recover_from_interpolated_ty_qpath {
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($self: expr, $allow_qpath_recovery: expr) => {
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if $allow_qpath_recovery && $self.look_ahead(1, |t| t == &token::ModSep) {
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if let token::Interpolated(nt) = &$self.token.kind {
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if let token::NtTy(ty) = &**nt {
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let ty = ty.clone();
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$self.bump();
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return $self.maybe_recover_from_bad_qpath_stage_2($self.prev_span, ty);
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}
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}
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}
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}
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}
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#[derive(Debug, Clone, Copy, PartialEq)]
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enum PrevTokenKind {
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DocComment,
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Comma,
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Plus,
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Interpolated,
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Eof,
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Ident,
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BitOr,
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Other,
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}
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// NOTE: `Ident`s are handled by `common.rs`.
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#[derive(Clone)]
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pub struct Parser<'a> {
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pub sess: &'a ParseSess,
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/// The current normalized token.
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/// "Normalized" means that some interpolated tokens
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/// (`$i: ident` and `$l: lifetime` meta-variables) are replaced
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/// with non-interpolated identifier and lifetime tokens they refer to.
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/// Perhaps the normalized / non-normalized setup can be simplified somehow.
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pub token: Token,
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/// The span of the current non-normalized token.
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meta_var_span: Option<Span>,
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/// The span of the previous non-normalized token.
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pub prev_span: Span,
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/// The kind of the previous normalized token (in simplified form).
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prev_token_kind: PrevTokenKind,
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restrictions: Restrictions,
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/// Used to determine the path to externally loaded source files.
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pub(super) directory: Directory<'a>,
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/// `true` to parse sub-modules in other files.
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pub(super) recurse_into_file_modules: bool,
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/// Name of the root module this parser originated from. If `None`, then the
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/// name is not known. This does not change while the parser is descending
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/// into modules, and sub-parsers have new values for this name.
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pub root_module_name: Option<String>,
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expected_tokens: Vec<TokenType>,
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token_cursor: TokenCursor,
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desugar_doc_comments: bool,
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/// `true` we should configure out of line modules as we parse.
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cfg_mods: bool,
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/// This field is used to keep track of how many left angle brackets we have seen. This is
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/// required in order to detect extra leading left angle brackets (`<` characters) and error
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/// appropriately.
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///
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/// See the comments in the `parse_path_segment` function for more details.
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unmatched_angle_bracket_count: u32,
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max_angle_bracket_count: u32,
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/// A list of all unclosed delimiters found by the lexer. If an entry is used for error recovery
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/// it gets removed from here. Every entry left at the end gets emitted as an independent
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/// error.
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pub(super) unclosed_delims: Vec<UnmatchedBrace>,
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last_unexpected_token_span: Option<Span>,
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pub last_type_ascription: Option<(Span, bool /* likely path typo */)>,
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/// If present, this `Parser` is not parsing Rust code but rather a macro call.
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subparser_name: Option<&'static str>,
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}
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impl<'a> Drop for Parser<'a> {
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fn drop(&mut self) {
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emit_unclosed_delims(&mut self.unclosed_delims, &self.sess);
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}
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}
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#[derive(Clone)]
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struct TokenCursor {
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frame: TokenCursorFrame,
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stack: Vec<TokenCursorFrame>,
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}
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#[derive(Clone)]
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struct TokenCursorFrame {
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delim: token::DelimToken,
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span: DelimSpan,
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open_delim: bool,
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tree_cursor: tokenstream::Cursor,
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close_delim: bool,
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last_token: LastToken,
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}
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/// This is used in `TokenCursorFrame` above to track tokens that are consumed
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/// by the parser, and then that's transitively used to record the tokens that
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/// each parse AST item is created with.
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///
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/// Right now this has two states, either collecting tokens or not collecting
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/// tokens. If we're collecting tokens we just save everything off into a local
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/// `Vec`. This should eventually though likely save tokens from the original
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/// token stream and just use slicing of token streams to avoid creation of a
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/// whole new vector.
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///
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/// The second state is where we're passively not recording tokens, but the last
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/// token is still tracked for when we want to start recording tokens. This
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/// "last token" means that when we start recording tokens we'll want to ensure
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/// that this, the first token, is included in the output.
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///
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/// You can find some more example usage of this in the `collect_tokens` method
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/// on the parser.
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#[derive(Clone)]
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enum LastToken {
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Collecting(Vec<TreeAndJoint>),
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Was(Option<TreeAndJoint>),
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}
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impl TokenCursorFrame {
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fn new(span: DelimSpan, delim: DelimToken, tts: &TokenStream) -> Self {
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TokenCursorFrame {
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delim,
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span,
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open_delim: delim == token::NoDelim,
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tree_cursor: tts.clone().into_trees(),
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close_delim: delim == token::NoDelim,
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last_token: LastToken::Was(None),
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}
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}
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}
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impl TokenCursor {
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fn next(&mut self) -> Token {
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loop {
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let tree = if !self.frame.open_delim {
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self.frame.open_delim = true;
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TokenTree::open_tt(self.frame.span, self.frame.delim)
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} else if let Some(tree) = self.frame.tree_cursor.next() {
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tree
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} else if !self.frame.close_delim {
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self.frame.close_delim = true;
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TokenTree::close_tt(self.frame.span, self.frame.delim)
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} else if let Some(frame) = self.stack.pop() {
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self.frame = frame;
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continue
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} else {
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return Token::new(token::Eof, DUMMY_SP);
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};
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match self.frame.last_token {
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LastToken::Collecting(ref mut v) => v.push(tree.clone().into()),
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LastToken::Was(ref mut t) => *t = Some(tree.clone().into()),
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}
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match tree {
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TokenTree::Token(token) => return token,
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TokenTree::Delimited(sp, delim, tts) => {
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let frame = TokenCursorFrame::new(sp, delim, &tts);
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self.stack.push(mem::replace(&mut self.frame, frame));
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}
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}
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}
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}
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fn next_desugared(&mut self) -> Token {
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let (name, sp) = match self.next() {
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Token { kind: token::DocComment(name), span } => (name, span),
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tok => return tok,
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};
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let stripped = strip_doc_comment_decoration(&name.as_str());
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// Searches for the occurrences of `"#*` and returns the minimum number of `#`s
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// required to wrap the text.
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let mut num_of_hashes = 0;
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let mut count = 0;
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for ch in stripped.chars() {
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count = match ch {
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'"' => 1,
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'#' if count > 0 => count + 1,
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_ => 0,
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};
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num_of_hashes = cmp::max(num_of_hashes, count);
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}
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let delim_span = DelimSpan::from_single(sp);
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let body = TokenTree::Delimited(
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delim_span,
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token::Bracket,
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[
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TokenTree::token(token::Ident(sym::doc, false), sp),
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TokenTree::token(token::Eq, sp),
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TokenTree::token(TokenKind::lit(
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token::StrRaw(num_of_hashes), Symbol::intern(&stripped), None
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), sp),
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]
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.iter().cloned().collect::<TokenStream>().into(),
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);
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self.stack.push(mem::replace(&mut self.frame, TokenCursorFrame::new(
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delim_span,
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token::NoDelim,
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&if doc_comment_style(&name.as_str()) == AttrStyle::Inner {
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[TokenTree::token(token::Pound, sp), TokenTree::token(token::Not, sp), body]
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.iter().cloned().collect::<TokenStream>()
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} else {
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[TokenTree::token(token::Pound, sp), body]
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.iter().cloned().collect::<TokenStream>()
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},
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)));
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self.next()
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}
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}
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#[derive(Clone, PartialEq)]
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enum TokenType {
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Token(TokenKind),
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Keyword(Symbol),
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Operator,
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Lifetime,
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Ident,
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Path,
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Type,
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Const,
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}
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impl TokenType {
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fn to_string(&self) -> String {
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match *self {
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TokenType::Token(ref t) => format!("`{}`", pprust::token_kind_to_string(t)),
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TokenType::Keyword(kw) => format!("`{}`", kw),
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TokenType::Operator => "an operator".to_string(),
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TokenType::Lifetime => "lifetime".to_string(),
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TokenType::Ident => "identifier".to_string(),
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TokenType::Path => "path".to_string(),
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TokenType::Type => "type".to_string(),
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TokenType::Const => "const".to_string(),
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}
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}
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}
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#[derive(Copy, Clone, Debug)]
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enum TokenExpectType {
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Expect,
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NoExpect,
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}
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/// A sequence separator.
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struct SeqSep {
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/// The separator token.
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sep: Option<TokenKind>,
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/// `true` if a trailing separator is allowed.
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trailing_sep_allowed: bool,
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}
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impl SeqSep {
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fn trailing_allowed(t: TokenKind) -> SeqSep {
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SeqSep {
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sep: Some(t),
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trailing_sep_allowed: true,
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}
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}
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fn none() -> SeqSep {
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SeqSep {
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sep: None,
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trailing_sep_allowed: false,
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}
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}
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}
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pub enum FollowedByType { Yes, No }
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impl<'a> Parser<'a> {
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pub fn new(
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sess: &'a ParseSess,
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tokens: TokenStream,
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directory: Option<Directory<'a>>,
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recurse_into_file_modules: bool,
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desugar_doc_comments: bool,
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subparser_name: Option<&'static str>,
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) -> Self {
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let mut parser = Parser {
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sess,
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token: Token::dummy(),
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prev_span: DUMMY_SP,
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meta_var_span: None,
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prev_token_kind: PrevTokenKind::Other,
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restrictions: Restrictions::empty(),
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recurse_into_file_modules,
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directory: Directory {
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path: Cow::from(PathBuf::new()),
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ownership: DirectoryOwnership::Owned { relative: None }
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},
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root_module_name: None,
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expected_tokens: Vec::new(),
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token_cursor: TokenCursor {
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frame: TokenCursorFrame::new(
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DelimSpan::dummy(),
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token::NoDelim,
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&tokens.into(),
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),
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stack: Vec::new(),
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},
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desugar_doc_comments,
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cfg_mods: true,
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unmatched_angle_bracket_count: 0,
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max_angle_bracket_count: 0,
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unclosed_delims: Vec::new(),
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last_unexpected_token_span: None,
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last_type_ascription: None,
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subparser_name,
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};
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parser.token = parser.next_tok();
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if let Some(directory) = directory {
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parser.directory = directory;
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} else if !parser.token.span.is_dummy() {
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if let Some(FileName::Real(path)) =
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&sess.source_map().lookup_char_pos(parser.token.span.lo()).file.unmapped_path {
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if let Some(directory_path) = path.parent() {
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parser.directory.path = Cow::from(directory_path.to_path_buf());
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}
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}
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}
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parser.process_potential_macro_variable();
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parser
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}
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|
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fn next_tok(&mut self) -> Token {
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let mut next = if self.desugar_doc_comments {
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self.token_cursor.next_desugared()
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} else {
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self.token_cursor.next()
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};
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if next.span.is_dummy() {
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|
// Tweak the location for better diagnostics, but keep syntactic context intact.
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next.span = self.prev_span.with_ctxt(next.span.ctxt());
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}
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next
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}
|
|
|
|
/// Converts the current token to a string using `self`'s reader.
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|
pub fn this_token_to_string(&self) -> String {
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pprust::token_to_string(&self.token)
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|
}
|
|
|
|
fn token_descr(&self) -> Option<&'static str> {
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|
Some(match &self.token.kind {
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|
_ if self.token.is_special_ident() => "reserved identifier",
|
|
_ if self.token.is_used_keyword() => "keyword",
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|
_ if self.token.is_unused_keyword() => "reserved keyword",
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|
token::DocComment(..) => "doc comment",
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_ => return None,
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})
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|
}
|
|
|
|
pub(super) fn this_token_descr(&self) -> String {
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|
if let Some(prefix) = self.token_descr() {
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format!("{} `{}`", prefix, self.this_token_to_string())
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|
} else {
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|
format!("`{}`", self.this_token_to_string())
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|
}
|
|
}
|
|
|
|
crate fn unexpected<T>(&mut self) -> PResult<'a, T> {
|
|
match self.expect_one_of(&[], &[]) {
|
|
Err(e) => Err(e),
|
|
// We can get `Ok(true)` from `recover_closing_delimiter`
|
|
// which is called in `expected_one_of_not_found`.
|
|
Ok(_) => FatalError.raise(),
|
|
}
|
|
}
|
|
|
|
/// Expects and consumes the token `t`. Signals an error if the next token is not `t`.
|
|
pub fn expect(&mut self, t: &TokenKind) -> PResult<'a, bool /* recovered */> {
|
|
if self.expected_tokens.is_empty() {
|
|
if self.token == *t {
|
|
self.bump();
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|
Ok(false)
|
|
} else {
|
|
self.unexpected_try_recover(t)
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|
}
|
|
} else {
|
|
self.expect_one_of(slice::from_ref(t), &[])
|
|
}
|
|
}
|
|
|
|
/// Expect next token to be edible or inedible token. If edible,
|
|
/// then consume it; if inedible, then return without consuming
|
|
/// anything. Signal a fatal error if next token is unexpected.
|
|
pub fn expect_one_of(
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|
&mut self,
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|
edible: &[TokenKind],
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|
inedible: &[TokenKind],
|
|
) -> PResult<'a, bool /* recovered */> {
|
|
if edible.contains(&self.token.kind) {
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|
self.bump();
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|
Ok(false)
|
|
} else if inedible.contains(&self.token.kind) {
|
|
// leave it in the input
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|
Ok(false)
|
|
} else if self.last_unexpected_token_span == Some(self.token.span) {
|
|
FatalError.raise();
|
|
} else {
|
|
self.expected_one_of_not_found(edible, inedible)
|
|
}
|
|
}
|
|
|
|
fn parse_ident(&mut self) -> PResult<'a, ast::Ident> {
|
|
self.parse_ident_common(true)
|
|
}
|
|
|
|
fn parse_ident_common(&mut self, recover: bool) -> PResult<'a, ast::Ident> {
|
|
match self.token.kind {
|
|
token::Ident(name, _) => {
|
|
if self.token.is_reserved_ident() {
|
|
let mut err = self.expected_ident_found();
|
|
if recover {
|
|
err.emit();
|
|
} else {
|
|
return Err(err);
|
|
}
|
|
}
|
|
let span = self.token.span;
|
|
self.bump();
|
|
Ok(Ident::new(name, span))
|
|
}
|
|
_ => {
|
|
Err(if self.prev_token_kind == PrevTokenKind::DocComment {
|
|
self.span_fatal_err(self.prev_span, Error::UselessDocComment)
|
|
} else {
|
|
self.expected_ident_found()
|
|
})
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Checks if the next token is `tok`, and returns `true` if so.
|
|
///
|
|
/// This method will automatically add `tok` to `expected_tokens` if `tok` is not
|
|
/// encountered.
|
|
fn check(&mut self, tok: &TokenKind) -> bool {
|
|
let is_present = self.token == *tok;
|
|
if !is_present { self.expected_tokens.push(TokenType::Token(tok.clone())); }
|
|
is_present
|
|
}
|
|
|
|
/// Consumes a token 'tok' if it exists. Returns whether the given token was present.
|
|
pub fn eat(&mut self, tok: &TokenKind) -> bool {
|
|
let is_present = self.check(tok);
|
|
if is_present { self.bump() }
|
|
is_present
|
|
}
|
|
|
|
/// If the next token is the given keyword, returns `true` without eating it.
|
|
/// An expectation is also added for diagnostics purposes.
|
|
fn check_keyword(&mut self, kw: Symbol) -> bool {
|
|
self.expected_tokens.push(TokenType::Keyword(kw));
|
|
self.token.is_keyword(kw)
|
|
}
|
|
|
|
/// If the next token is the given keyword, eats it and returns `true`.
|
|
/// Otherwise, returns `false`. An expectation is also added for diagnostics purposes.
|
|
fn eat_keyword(&mut self, kw: Symbol) -> bool {
|
|
if self.check_keyword(kw) {
|
|
self.bump();
|
|
true
|
|
} else {
|
|
false
|
|
}
|
|
}
|
|
|
|
fn eat_keyword_noexpect(&mut self, kw: Symbol) -> bool {
|
|
if self.token.is_keyword(kw) {
|
|
self.bump();
|
|
true
|
|
} else {
|
|
false
|
|
}
|
|
}
|
|
|
|
/// If the given word is not a keyword, signals an error.
|
|
/// If the next token is not the given word, signals an error.
|
|
/// Otherwise, eats it.
|
|
fn expect_keyword(&mut self, kw: Symbol) -> PResult<'a, ()> {
|
|
if !self.eat_keyword(kw) {
|
|
self.unexpected()
|
|
} else {
|
|
Ok(())
|
|
}
|
|
}
|
|
|
|
fn check_or_expected(&mut self, ok: bool, typ: TokenType) -> bool {
|
|
if ok {
|
|
true
|
|
} else {
|
|
self.expected_tokens.push(typ);
|
|
false
|
|
}
|
|
}
|
|
|
|
fn check_ident(&mut self) -> bool {
|
|
self.check_or_expected(self.token.is_ident(), TokenType::Ident)
|
|
}
|
|
|
|
fn check_path(&mut self) -> bool {
|
|
self.check_or_expected(self.token.is_path_start(), TokenType::Path)
|
|
}
|
|
|
|
fn check_type(&mut self) -> bool {
|
|
self.check_or_expected(self.token.can_begin_type(), TokenType::Type)
|
|
}
|
|
|
|
fn check_const_arg(&mut self) -> bool {
|
|
self.check_or_expected(self.token.can_begin_const_arg(), TokenType::Const)
|
|
}
|
|
|
|
/// Checks to see if the next token is either `+` or `+=`.
|
|
/// Otherwise returns `false`.
|
|
fn check_plus(&mut self) -> bool {
|
|
self.check_or_expected(
|
|
self.token.is_like_plus(),
|
|
TokenType::Token(token::BinOp(token::Plus)),
|
|
)
|
|
}
|
|
|
|
/// Expects and consumes a `+`. if `+=` is seen, replaces it with a `=`
|
|
/// and continues. If a `+` is not seen, returns `false`.
|
|
///
|
|
/// This is used when token-splitting `+=` into `+`.
|
|
/// See issue #47856 for an example of when this may occur.
|
|
fn eat_plus(&mut self) -> bool {
|
|
self.expected_tokens.push(TokenType::Token(token::BinOp(token::Plus)));
|
|
match self.token.kind {
|
|
token::BinOp(token::Plus) => {
|
|
self.bump();
|
|
true
|
|
}
|
|
token::BinOpEq(token::Plus) => {
|
|
let span = self.token.span.with_lo(self.token.span.lo() + BytePos(1));
|
|
self.bump_with(token::Eq, span);
|
|
true
|
|
}
|
|
_ => false,
|
|
}
|
|
}
|
|
|
|
/// Expects and consumes an `&`. If `&&` is seen, replaces it with a single
|
|
/// `&` and continues. If an `&` is not seen, signals an error.
|
|
fn expect_and(&mut self) -> PResult<'a, ()> {
|
|
self.expected_tokens.push(TokenType::Token(token::BinOp(token::And)));
|
|
match self.token.kind {
|
|
token::BinOp(token::And) => {
|
|
self.bump();
|
|
Ok(())
|
|
}
|
|
token::AndAnd => {
|
|
let span = self.token.span.with_lo(self.token.span.lo() + BytePos(1));
|
|
Ok(self.bump_with(token::BinOp(token::And), span))
|
|
}
|
|
_ => self.unexpected()
|
|
}
|
|
}
|
|
|
|
/// Expects and consumes an `|`. If `||` is seen, replaces it with a single
|
|
/// `|` and continues. If an `|` is not seen, signals an error.
|
|
fn expect_or(&mut self) -> PResult<'a, ()> {
|
|
self.expected_tokens.push(TokenType::Token(token::BinOp(token::Or)));
|
|
match self.token.kind {
|
|
token::BinOp(token::Or) => {
|
|
self.bump();
|
|
Ok(())
|
|
}
|
|
token::OrOr => {
|
|
let span = self.token.span.with_lo(self.token.span.lo() + BytePos(1));
|
|
Ok(self.bump_with(token::BinOp(token::Or), span))
|
|
}
|
|
_ => self.unexpected()
|
|
}
|
|
}
|
|
|
|
/// Attempts to consume a `<`. If `<<` is seen, replaces it with a single
|
|
/// `<` and continue. If `<-` is seen, replaces it with a single `<`
|
|
/// and continue. If a `<` is not seen, returns false.
|
|
///
|
|
/// This is meant to be used when parsing generics on a path to get the
|
|
/// starting token.
|
|
fn eat_lt(&mut self) -> bool {
|
|
self.expected_tokens.push(TokenType::Token(token::Lt));
|
|
let ate = match self.token.kind {
|
|
token::Lt => {
|
|
self.bump();
|
|
true
|
|
}
|
|
token::BinOp(token::Shl) => {
|
|
let span = self.token.span.with_lo(self.token.span.lo() + BytePos(1));
|
|
self.bump_with(token::Lt, span);
|
|
true
|
|
}
|
|
token::LArrow => {
|
|
let span = self.token.span.with_lo(self.token.span.lo() + BytePos(1));
|
|
self.bump_with(token::BinOp(token::Minus), span);
|
|
true
|
|
}
|
|
_ => false,
|
|
};
|
|
|
|
if ate {
|
|
// See doc comment for `unmatched_angle_bracket_count`.
|
|
self.unmatched_angle_bracket_count += 1;
|
|
self.max_angle_bracket_count += 1;
|
|
debug!("eat_lt: (increment) count={:?}", self.unmatched_angle_bracket_count);
|
|
}
|
|
|
|
ate
|
|
}
|
|
|
|
fn expect_lt(&mut self) -> PResult<'a, ()> {
|
|
if !self.eat_lt() {
|
|
self.unexpected()
|
|
} else {
|
|
Ok(())
|
|
}
|
|
}
|
|
|
|
/// Expects and consumes a single `>` token. if a `>>` is seen, replaces it
|
|
/// with a single `>` and continues. If a `>` is not seen, signals an error.
|
|
fn expect_gt(&mut self) -> PResult<'a, ()> {
|
|
self.expected_tokens.push(TokenType::Token(token::Gt));
|
|
let ate = match self.token.kind {
|
|
token::Gt => {
|
|
self.bump();
|
|
Some(())
|
|
}
|
|
token::BinOp(token::Shr) => {
|
|
let span = self.token.span.with_lo(self.token.span.lo() + BytePos(1));
|
|
Some(self.bump_with(token::Gt, span))
|
|
}
|
|
token::BinOpEq(token::Shr) => {
|
|
let span = self.token.span.with_lo(self.token.span.lo() + BytePos(1));
|
|
Some(self.bump_with(token::Ge, span))
|
|
}
|
|
token::Ge => {
|
|
let span = self.token.span.with_lo(self.token.span.lo() + BytePos(1));
|
|
Some(self.bump_with(token::Eq, span))
|
|
}
|
|
_ => None,
|
|
};
|
|
|
|
match ate {
|
|
Some(_) => {
|
|
// See doc comment for `unmatched_angle_bracket_count`.
|
|
if self.unmatched_angle_bracket_count > 0 {
|
|
self.unmatched_angle_bracket_count -= 1;
|
|
debug!("expect_gt: (decrement) count={:?}", self.unmatched_angle_bracket_count);
|
|
}
|
|
|
|
Ok(())
|
|
},
|
|
None => self.unexpected(),
|
|
}
|
|
}
|
|
|
|
/// Parses a sequence, including the closing delimiter. The function
|
|
/// `f` must consume tokens until reaching the next separator or
|
|
/// closing bracket.
|
|
fn parse_seq_to_end<T>(
|
|
&mut self,
|
|
ket: &TokenKind,
|
|
sep: SeqSep,
|
|
f: impl FnMut(&mut Parser<'a>) -> PResult<'a, T>,
|
|
) -> PResult<'a, Vec<T>> {
|
|
let (val, _, recovered) = self.parse_seq_to_before_end(ket, sep, f)?;
|
|
if !recovered {
|
|
self.bump();
|
|
}
|
|
Ok(val)
|
|
}
|
|
|
|
/// Parses a sequence, not including the closing delimiter. The function
|
|
/// `f` must consume tokens until reaching the next separator or
|
|
/// closing bracket.
|
|
fn parse_seq_to_before_end<T>(
|
|
&mut self,
|
|
ket: &TokenKind,
|
|
sep: SeqSep,
|
|
f: impl FnMut(&mut Parser<'a>) -> PResult<'a, T>,
|
|
) -> PResult<'a, (Vec<T>, bool, bool)> {
|
|
self.parse_seq_to_before_tokens(&[ket], sep, TokenExpectType::Expect, f)
|
|
}
|
|
|
|
fn expect_any_with_type(&mut self, kets: &[&TokenKind], expect: TokenExpectType) -> bool {
|
|
kets.iter().any(|k| {
|
|
match expect {
|
|
TokenExpectType::Expect => self.check(k),
|
|
TokenExpectType::NoExpect => self.token == **k,
|
|
}
|
|
})
|
|
}
|
|
|
|
fn parse_seq_to_before_tokens<T>(
|
|
&mut self,
|
|
kets: &[&TokenKind],
|
|
sep: SeqSep,
|
|
expect: TokenExpectType,
|
|
mut f: impl FnMut(&mut Parser<'a>) -> PResult<'a, T>,
|
|
) -> PResult<'a, (Vec<T>, bool /* trailing */, bool /* recovered */)> {
|
|
let mut first = true;
|
|
let mut recovered = false;
|
|
let mut trailing = false;
|
|
let mut v = vec![];
|
|
while !self.expect_any_with_type(kets, expect) {
|
|
if let token::CloseDelim(..) | token::Eof = self.token.kind {
|
|
break
|
|
}
|
|
if let Some(ref t) = sep.sep {
|
|
if first {
|
|
first = false;
|
|
} else {
|
|
match self.expect(t) {
|
|
Ok(false) => {}
|
|
Ok(true) => {
|
|
recovered = true;
|
|
break;
|
|
}
|
|
Err(mut expect_err) => {
|
|
let sp = self.sess.source_map().next_point(self.prev_span);
|
|
let token_str = pprust::token_kind_to_string(t);
|
|
|
|
// Attempt to keep parsing if it was a similar separator.
|
|
if let Some(ref tokens) = t.similar_tokens() {
|
|
if tokens.contains(&self.token.kind) {
|
|
self.bump();
|
|
}
|
|
}
|
|
|
|
// Attempt to keep parsing if it was an omitted separator.
|
|
match f(self) {
|
|
Ok(t) => {
|
|
// Parsed successfully, therefore most probably the code only
|
|
// misses a separator.
|
|
expect_err
|
|
.span_suggestion_short(
|
|
sp,
|
|
&format!("missing `{}`", token_str),
|
|
token_str,
|
|
Applicability::MaybeIncorrect,
|
|
)
|
|
.emit();
|
|
|
|
v.push(t);
|
|
continue;
|
|
},
|
|
Err(mut e) => {
|
|
// Parsing failed, therefore it must be something more serious
|
|
// than just a missing separator.
|
|
expect_err.emit();
|
|
|
|
e.cancel();
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
if sep.trailing_sep_allowed && self.expect_any_with_type(kets, expect) {
|
|
trailing = true;
|
|
break;
|
|
}
|
|
|
|
let t = f(self)?;
|
|
v.push(t);
|
|
}
|
|
|
|
Ok((v, trailing, recovered))
|
|
}
|
|
|
|
/// Parses a sequence, including the closing delimiter. The function
|
|
/// `f` must consume tokens until reaching the next separator or
|
|
/// closing bracket.
|
|
fn parse_unspanned_seq<T>(
|
|
&mut self,
|
|
bra: &TokenKind,
|
|
ket: &TokenKind,
|
|
sep: SeqSep,
|
|
f: impl FnMut(&mut Parser<'a>) -> PResult<'a, T>,
|
|
) -> PResult<'a, (Vec<T>, bool)> {
|
|
self.expect(bra)?;
|
|
let (result, trailing, recovered) = self.parse_seq_to_before_end(ket, sep, f)?;
|
|
if !recovered {
|
|
self.eat(ket);
|
|
}
|
|
Ok((result, trailing))
|
|
}
|
|
|
|
fn parse_delim_comma_seq<T>(
|
|
&mut self,
|
|
delim: DelimToken,
|
|
f: impl FnMut(&mut Parser<'a>) -> PResult<'a, T>,
|
|
) -> PResult<'a, (Vec<T>, bool)> {
|
|
self.parse_unspanned_seq(
|
|
&token::OpenDelim(delim),
|
|
&token::CloseDelim(delim),
|
|
SeqSep::trailing_allowed(token::Comma),
|
|
f,
|
|
)
|
|
}
|
|
|
|
fn parse_paren_comma_seq<T>(
|
|
&mut self,
|
|
f: impl FnMut(&mut Parser<'a>) -> PResult<'a, T>,
|
|
) -> PResult<'a, (Vec<T>, bool)> {
|
|
self.parse_delim_comma_seq(token::Paren, f)
|
|
}
|
|
|
|
/// Advance the parser by one token.
|
|
pub fn bump(&mut self) {
|
|
if self.prev_token_kind == PrevTokenKind::Eof {
|
|
// Bumping after EOF is a bad sign, usually an infinite loop.
|
|
self.bug("attempted to bump the parser past EOF (may be stuck in a loop)");
|
|
}
|
|
|
|
self.prev_span = self.meta_var_span.take().unwrap_or(self.token.span);
|
|
|
|
// Record last token kind for possible error recovery.
|
|
self.prev_token_kind = match self.token.kind {
|
|
token::DocComment(..) => PrevTokenKind::DocComment,
|
|
token::Comma => PrevTokenKind::Comma,
|
|
token::BinOp(token::Plus) => PrevTokenKind::Plus,
|
|
token::BinOp(token::Or) => PrevTokenKind::BitOr,
|
|
token::Interpolated(..) => PrevTokenKind::Interpolated,
|
|
token::Eof => PrevTokenKind::Eof,
|
|
token::Ident(..) => PrevTokenKind::Ident,
|
|
_ => PrevTokenKind::Other,
|
|
};
|
|
|
|
self.token = self.next_tok();
|
|
self.expected_tokens.clear();
|
|
// Check after each token.
|
|
self.process_potential_macro_variable();
|
|
}
|
|
|
|
/// Advances the parser using provided token as a next one. Use this when
|
|
/// consuming a part of a token. For example a single `<` from `<<`.
|
|
fn bump_with(&mut self, next: TokenKind, span: Span) {
|
|
self.prev_span = self.token.span.with_hi(span.lo());
|
|
// It would be incorrect to record the kind of the current token, but
|
|
// fortunately for tokens currently using `bump_with`, the
|
|
// `prev_token_kind` will be of no use anyway.
|
|
self.prev_token_kind = PrevTokenKind::Other;
|
|
self.token = Token::new(next, span);
|
|
self.expected_tokens.clear();
|
|
}
|
|
|
|
/// Look-ahead `dist` tokens of `self.token` and get access to that token there.
|
|
/// When `dist == 0` then the current token is looked at.
|
|
pub fn look_ahead<R>(&self, dist: usize, looker: impl FnOnce(&Token) -> R) -> R {
|
|
if dist == 0 {
|
|
return looker(&self.token);
|
|
}
|
|
|
|
let frame = &self.token_cursor.frame;
|
|
looker(&match frame.tree_cursor.look_ahead(dist - 1) {
|
|
Some(tree) => match tree {
|
|
TokenTree::Token(token) => token,
|
|
TokenTree::Delimited(dspan, delim, _) =>
|
|
Token::new(token::OpenDelim(delim), dspan.open),
|
|
}
|
|
None => Token::new(token::CloseDelim(frame.delim), frame.span.close)
|
|
})
|
|
}
|
|
|
|
/// Returns whether any of the given keywords are `dist` tokens ahead of the current one.
|
|
fn is_keyword_ahead(&self, dist: usize, kws: &[Symbol]) -> bool {
|
|
self.look_ahead(dist, |t| kws.iter().any(|&kw| t.is_keyword(kw)))
|
|
}
|
|
|
|
/// Parses asyncness: `async` or nothing.
|
|
fn parse_asyncness(&mut self) -> IsAsync {
|
|
if self.eat_keyword(kw::Async) {
|
|
IsAsync::Async {
|
|
closure_id: DUMMY_NODE_ID,
|
|
return_impl_trait_id: DUMMY_NODE_ID,
|
|
}
|
|
} else {
|
|
IsAsync::NotAsync
|
|
}
|
|
}
|
|
|
|
/// Parses unsafety: `unsafe` or nothing.
|
|
fn parse_unsafety(&mut self) -> Unsafety {
|
|
if self.eat_keyword(kw::Unsafe) {
|
|
Unsafety::Unsafe
|
|
} else {
|
|
Unsafety::Normal
|
|
}
|
|
}
|
|
|
|
/// Parses mutability (`mut` or nothing).
|
|
fn parse_mutability(&mut self) -> Mutability {
|
|
if self.eat_keyword(kw::Mut) {
|
|
Mutability::Mutable
|
|
} else {
|
|
Mutability::Immutable
|
|
}
|
|
}
|
|
|
|
/// Possibly parses mutability (`const` or `mut`).
|
|
fn parse_const_or_mut(&mut self) -> Option<Mutability> {
|
|
if self.eat_keyword(kw::Mut) {
|
|
Some(Mutability::Mutable)
|
|
} else if self.eat_keyword(kw::Const) {
|
|
Some(Mutability::Immutable)
|
|
} else {
|
|
None
|
|
}
|
|
}
|
|
|
|
fn parse_field_name(&mut self) -> PResult<'a, Ident> {
|
|
if let token::Literal(token::Lit { kind: token::Integer, symbol, suffix }) =
|
|
self.token.kind {
|
|
self.expect_no_suffix(self.token.span, "a tuple index", suffix);
|
|
self.bump();
|
|
Ok(Ident::new(symbol, self.prev_span))
|
|
} else {
|
|
self.parse_ident_common(false)
|
|
}
|
|
}
|
|
|
|
fn expect_delimited_token_tree(&mut self) -> PResult<'a, (MacDelimiter, TokenStream)> {
|
|
let delim = match self.token.kind {
|
|
token::OpenDelim(delim) => delim,
|
|
_ => {
|
|
let msg = "expected open delimiter";
|
|
let mut err = self.fatal(msg);
|
|
err.span_label(self.token.span, msg);
|
|
return Err(err)
|
|
}
|
|
};
|
|
let tts = match self.parse_token_tree() {
|
|
TokenTree::Delimited(_, _, tts) => tts,
|
|
_ => unreachable!(),
|
|
};
|
|
let delim = match delim {
|
|
token::Paren => MacDelimiter::Parenthesis,
|
|
token::Bracket => MacDelimiter::Bracket,
|
|
token::Brace => MacDelimiter::Brace,
|
|
token::NoDelim => self.bug("unexpected no delimiter"),
|
|
};
|
|
Ok((delim, tts.into()))
|
|
}
|
|
|
|
fn parse_or_use_outer_attributes(
|
|
&mut self,
|
|
already_parsed_attrs: Option<ThinVec<Attribute>>,
|
|
) -> PResult<'a, ThinVec<Attribute>> {
|
|
if let Some(attrs) = already_parsed_attrs {
|
|
Ok(attrs)
|
|
} else {
|
|
self.parse_outer_attributes().map(|a| a.into())
|
|
}
|
|
}
|
|
|
|
pub fn process_potential_macro_variable(&mut self) {
|
|
self.token = match self.token.kind {
|
|
token::Dollar if self.token.span.from_expansion() &&
|
|
self.look_ahead(1, |t| t.is_ident()) => {
|
|
self.bump();
|
|
let name = match self.token.kind {
|
|
token::Ident(name, _) => name,
|
|
_ => unreachable!()
|
|
};
|
|
let span = self.prev_span.to(self.token.span);
|
|
self.diagnostic()
|
|
.struct_span_fatal(span, &format!("unknown macro variable `{}`", name))
|
|
.span_label(span, "unknown macro variable")
|
|
.emit();
|
|
self.bump();
|
|
return
|
|
}
|
|
token::Interpolated(ref nt) => {
|
|
self.meta_var_span = Some(self.token.span);
|
|
// Interpolated identifier and lifetime tokens are replaced with usual identifier
|
|
// and lifetime tokens, so the former are never encountered during normal parsing.
|
|
match **nt {
|
|
token::NtIdent(ident, is_raw) =>
|
|
Token::new(token::Ident(ident.name, is_raw), ident.span),
|
|
token::NtLifetime(ident) =>
|
|
Token::new(token::Lifetime(ident.name), ident.span),
|
|
_ => return,
|
|
}
|
|
}
|
|
_ => return,
|
|
};
|
|
}
|
|
|
|
/// Parses a single token tree from the input.
|
|
pub fn parse_token_tree(&mut self) -> TokenTree {
|
|
match self.token.kind {
|
|
token::OpenDelim(..) => {
|
|
let frame = mem::replace(&mut self.token_cursor.frame,
|
|
self.token_cursor.stack.pop().unwrap());
|
|
self.token.span = frame.span.entire();
|
|
self.bump();
|
|
TokenTree::Delimited(
|
|
frame.span,
|
|
frame.delim,
|
|
frame.tree_cursor.stream.into(),
|
|
)
|
|
},
|
|
token::CloseDelim(_) | token::Eof => unreachable!(),
|
|
_ => {
|
|
let token = self.token.take();
|
|
self.bump();
|
|
TokenTree::Token(token)
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Parses a stream of tokens into a list of `TokenTree`s, up to EOF.
|
|
pub fn parse_all_token_trees(&mut self) -> PResult<'a, Vec<TokenTree>> {
|
|
let mut tts = Vec::new();
|
|
while self.token != token::Eof {
|
|
tts.push(self.parse_token_tree());
|
|
}
|
|
Ok(tts)
|
|
}
|
|
|
|
pub fn parse_tokens(&mut self) -> TokenStream {
|
|
let mut result = Vec::new();
|
|
loop {
|
|
match self.token.kind {
|
|
token::Eof | token::CloseDelim(..) => break,
|
|
_ => result.push(self.parse_token_tree().into()),
|
|
}
|
|
}
|
|
TokenStream::new(result)
|
|
}
|
|
|
|
/// Evaluates the closure with restrictions in place.
|
|
///
|
|
/// Afters the closure is evaluated, restrictions are reset.
|
|
fn with_res<T>(&mut self, res: Restrictions, f: impl FnOnce(&mut Self) -> T) -> T {
|
|
let old = self.restrictions;
|
|
self.restrictions = res;
|
|
let res = f(self);
|
|
self.restrictions = old;
|
|
res
|
|
}
|
|
|
|
fn is_crate_vis(&self) -> bool {
|
|
self.token.is_keyword(kw::Crate) && self.look_ahead(1, |t| t != &token::ModSep)
|
|
}
|
|
|
|
/// Parses `pub`, `pub(crate)` and `pub(in path)` plus shortcuts `crate` for `pub(crate)`,
|
|
/// `pub(self)` for `pub(in self)` and `pub(super)` for `pub(in super)`.
|
|
/// If the following element can't be a tuple (i.e., it's a function definition), then
|
|
/// it's not a tuple struct field), and the contents within the parentheses isn't valid,
|
|
/// so emit a proper diagnostic.
|
|
pub fn parse_visibility(&mut self, fbt: FollowedByType) -> PResult<'a, Visibility> {
|
|
maybe_whole!(self, NtVis, |x| x);
|
|
|
|
self.expected_tokens.push(TokenType::Keyword(kw::Crate));
|
|
if self.is_crate_vis() {
|
|
self.bump(); // `crate`
|
|
self.sess.gated_spans.gate(sym::crate_visibility_modifier, self.prev_span);
|
|
return Ok(respan(self.prev_span, VisibilityKind::Crate(CrateSugar::JustCrate)));
|
|
}
|
|
|
|
if !self.eat_keyword(kw::Pub) {
|
|
// We need a span for our `Spanned<VisibilityKind>`, but there's inherently no
|
|
// keyword to grab a span from for inherited visibility; an empty span at the
|
|
// beginning of the current token would seem to be the "Schelling span".
|
|
return Ok(respan(self.token.span.shrink_to_lo(), VisibilityKind::Inherited))
|
|
}
|
|
let lo = self.prev_span;
|
|
|
|
if self.check(&token::OpenDelim(token::Paren)) {
|
|
// We don't `self.bump()` the `(` yet because this might be a struct definition where
|
|
// `()` or a tuple might be allowed. For example, `struct Struct(pub (), pub (usize));`.
|
|
// Because of this, we only `bump` the `(` if we're assured it is appropriate to do so
|
|
// by the following tokens.
|
|
if self.is_keyword_ahead(1, &[kw::Crate])
|
|
&& self.look_ahead(2, |t| t != &token::ModSep) // account for `pub(crate::foo)`
|
|
{
|
|
// Parse `pub(crate)`.
|
|
self.bump(); // `(`
|
|
self.bump(); // `crate`
|
|
self.expect(&token::CloseDelim(token::Paren))?; // `)`
|
|
let vis = VisibilityKind::Crate(CrateSugar::PubCrate);
|
|
return Ok(respan(lo.to(self.prev_span), vis));
|
|
} else if self.is_keyword_ahead(1, &[kw::In]) {
|
|
// Parse `pub(in path)`.
|
|
self.bump(); // `(`
|
|
self.bump(); // `in`
|
|
let path = self.parse_path(PathStyle::Mod)?; // `path`
|
|
self.expect(&token::CloseDelim(token::Paren))?; // `)`
|
|
let vis = VisibilityKind::Restricted {
|
|
path: P(path),
|
|
id: ast::DUMMY_NODE_ID,
|
|
};
|
|
return Ok(respan(lo.to(self.prev_span), vis));
|
|
} else if self.look_ahead(2, |t| t == &token::CloseDelim(token::Paren))
|
|
&& self.is_keyword_ahead(1, &[kw::Super, kw::SelfLower])
|
|
{
|
|
// Parse `pub(self)` or `pub(super)`.
|
|
self.bump(); // `(`
|
|
let path = self.parse_path(PathStyle::Mod)?; // `super`/`self`
|
|
self.expect(&token::CloseDelim(token::Paren))?; // `)`
|
|
let vis = VisibilityKind::Restricted {
|
|
path: P(path),
|
|
id: ast::DUMMY_NODE_ID,
|
|
};
|
|
return Ok(respan(lo.to(self.prev_span), vis));
|
|
} else if let FollowedByType::No = fbt {
|
|
// Provide this diagnostic if a type cannot follow;
|
|
// in particular, if this is not a tuple struct.
|
|
self.recover_incorrect_vis_restriction()?;
|
|
// Emit diagnostic, but continue with public visibility.
|
|
}
|
|
}
|
|
|
|
Ok(respan(lo, VisibilityKind::Public))
|
|
}
|
|
|
|
/// Recovery for e.g. `pub(something) fn ...` or `struct X { pub(something) y: Z }`
|
|
fn recover_incorrect_vis_restriction(&mut self) -> PResult<'a, ()> {
|
|
self.bump(); // `(`
|
|
let path = self.parse_path(PathStyle::Mod)?;
|
|
self.expect(&token::CloseDelim(token::Paren))?; // `)`
|
|
|
|
let msg = "incorrect visibility restriction";
|
|
let suggestion = r##"some possible visibility restrictions are:
|
|
`pub(crate)`: visible only on the current crate
|
|
`pub(super)`: visible only in the current module's parent
|
|
`pub(in path::to::module)`: visible only on the specified path"##;
|
|
|
|
let path_str = pprust::path_to_string(&path);
|
|
|
|
struct_span_err!(self.sess.span_diagnostic, path.span, E0704, "{}", msg)
|
|
.help(suggestion)
|
|
.span_suggestion(
|
|
path.span,
|
|
&format!("make this visible only to module `{}` with `in`", path_str),
|
|
format!("in {}", path_str),
|
|
Applicability::MachineApplicable,
|
|
)
|
|
.emit();
|
|
|
|
Ok(())
|
|
}
|
|
|
|
/// Parses `extern string_literal?`.
|
|
fn parse_extern(&mut self) -> PResult<'a, Extern> {
|
|
Ok(if self.eat_keyword(kw::Extern) {
|
|
Extern::from_abi(self.parse_abi())
|
|
} else {
|
|
Extern::None
|
|
})
|
|
}
|
|
|
|
/// Parses a string literal as an ABI spec.
|
|
fn parse_abi(&mut self) -> Option<StrLit> {
|
|
match self.parse_str_lit() {
|
|
Ok(str_lit) => Some(str_lit),
|
|
Err(Some(lit)) => match lit.kind {
|
|
ast::LitKind::Err(_) => None,
|
|
_ => {
|
|
self.struct_span_err(lit.span, "non-string ABI literal")
|
|
.span_suggestion(
|
|
lit.span,
|
|
"specify the ABI with a string literal",
|
|
"\"C\"".to_string(),
|
|
Applicability::MaybeIncorrect,
|
|
)
|
|
.emit();
|
|
None
|
|
}
|
|
}
|
|
Err(None) => None,
|
|
}
|
|
}
|
|
|
|
/// We are parsing `async fn`. If we are on Rust 2015, emit an error.
|
|
fn ban_async_in_2015(&self, async_span: Span) {
|
|
if async_span.rust_2015() {
|
|
struct_span_err!(
|
|
self.diagnostic(),
|
|
async_span,
|
|
E0670,
|
|
"`async fn` is not permitted in the 2015 edition",
|
|
)
|
|
.emit();
|
|
}
|
|
}
|
|
|
|
fn collect_tokens<R>(
|
|
&mut self,
|
|
f: impl FnOnce(&mut Self) -> PResult<'a, R>,
|
|
) -> PResult<'a, (R, TokenStream)> {
|
|
// Record all tokens we parse when parsing this item.
|
|
let mut tokens = Vec::new();
|
|
let prev_collecting = match self.token_cursor.frame.last_token {
|
|
LastToken::Collecting(ref mut list) => {
|
|
Some(mem::take(list))
|
|
}
|
|
LastToken::Was(ref mut last) => {
|
|
tokens.extend(last.take());
|
|
None
|
|
}
|
|
};
|
|
self.token_cursor.frame.last_token = LastToken::Collecting(tokens);
|
|
let prev = self.token_cursor.stack.len();
|
|
let ret = f(self);
|
|
let last_token = if self.token_cursor.stack.len() == prev {
|
|
&mut self.token_cursor.frame.last_token
|
|
} else if self.token_cursor.stack.get(prev).is_none() {
|
|
// This can happen due to a bad interaction of two unrelated recovery mechanisms with
|
|
// mismatched delimiters *and* recovery lookahead on the likely typo `pub ident(`
|
|
// (#62881).
|
|
return Ok((ret?, TokenStream::default()));
|
|
} else {
|
|
&mut self.token_cursor.stack[prev].last_token
|
|
};
|
|
|
|
// Pull out the tokens that we've collected from the call to `f` above.
|
|
let mut collected_tokens = match *last_token {
|
|
LastToken::Collecting(ref mut v) => mem::take(v),
|
|
LastToken::Was(ref was) => {
|
|
let msg = format!("our vector went away? - found Was({:?})", was);
|
|
debug!("collect_tokens: {}", msg);
|
|
self.sess.span_diagnostic.delay_span_bug(self.token.span, &msg);
|
|
// This can happen due to a bad interaction of two unrelated recovery mechanisms
|
|
// with mismatched delimiters *and* recovery lookahead on the likely typo
|
|
// `pub ident(` (#62895, different but similar to the case above).
|
|
return Ok((ret?, TokenStream::default()));
|
|
}
|
|
};
|
|
|
|
// If we're not at EOF our current token wasn't actually consumed by
|
|
// `f`, but it'll still be in our list that we pulled out. In that case
|
|
// put it back.
|
|
let extra_token = if self.token != token::Eof {
|
|
collected_tokens.pop()
|
|
} else {
|
|
None
|
|
};
|
|
|
|
// If we were previously collecting tokens, then this was a recursive
|
|
// call. In that case we need to record all the tokens we collected in
|
|
// our parent list as well. To do that we push a clone of our stream
|
|
// onto the previous list.
|
|
match prev_collecting {
|
|
Some(mut list) => {
|
|
list.extend(collected_tokens.iter().cloned());
|
|
list.extend(extra_token);
|
|
*last_token = LastToken::Collecting(list);
|
|
}
|
|
None => {
|
|
*last_token = LastToken::Was(extra_token);
|
|
}
|
|
}
|
|
|
|
Ok((ret?, TokenStream::new(collected_tokens)))
|
|
}
|
|
|
|
/// `::{` or `::*`
|
|
fn is_import_coupler(&mut self) -> bool {
|
|
self.check(&token::ModSep) &&
|
|
self.look_ahead(1, |t| *t == token::OpenDelim(token::Brace) ||
|
|
*t == token::BinOp(token::Star))
|
|
}
|
|
}
|
|
|
|
crate fn make_unclosed_delims_error(
|
|
unmatched: UnmatchedBrace,
|
|
sess: &ParseSess,
|
|
) -> Option<DiagnosticBuilder<'_>> {
|
|
// `None` here means an `Eof` was found. We already emit those errors elsewhere, we add them to
|
|
// `unmatched_braces` only for error recovery in the `Parser`.
|
|
let found_delim = unmatched.found_delim?;
|
|
let mut err = sess.span_diagnostic.struct_span_err(unmatched.found_span, &format!(
|
|
"incorrect close delimiter: `{}`",
|
|
pprust::token_kind_to_string(&token::CloseDelim(found_delim)),
|
|
));
|
|
err.span_label(unmatched.found_span, "incorrect close delimiter");
|
|
if let Some(sp) = unmatched.candidate_span {
|
|
err.span_label(sp, "close delimiter possibly meant for this");
|
|
}
|
|
if let Some(sp) = unmatched.unclosed_span {
|
|
err.span_label(sp, "un-closed delimiter");
|
|
}
|
|
Some(err)
|
|
}
|
|
|
|
pub fn emit_unclosed_delims(unclosed_delims: &mut Vec<UnmatchedBrace>, sess: &ParseSess) {
|
|
*sess.reached_eof.borrow_mut() |= unclosed_delims.iter()
|
|
.any(|unmatched_delim| unmatched_delim.found_delim.is_none());
|
|
for unmatched in unclosed_delims.drain(..) {
|
|
make_unclosed_delims_error(unmatched, sess).map(|mut e| e.emit());
|
|
}
|
|
}
|