1483 lines
54 KiB
Rust
1483 lines
54 KiB
Rust
pub mod attr;
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mod attr_wrapper;
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mod diagnostics;
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mod expr;
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mod generics;
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mod item;
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mod nonterminal;
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mod pat;
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mod path;
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mod stmt;
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mod ty;
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use crate::lexer::UnmatchedBrace;
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pub use attr_wrapper::AttrWrapper;
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pub use diagnostics::AttemptLocalParseRecovery;
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use diagnostics::Error;
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pub(crate) use item::FnParseMode;
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pub use pat::{CommaRecoveryMode, RecoverColon, RecoverComma};
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pub use path::PathStyle;
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use rustc_ast::ptr::P;
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use rustc_ast::token::{self, Delimiter, Nonterminal, Token, TokenKind};
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use rustc_ast::tokenstream::AttributesData;
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use rustc_ast::tokenstream::{self, DelimSpan, Spacing};
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use rustc_ast::tokenstream::{TokenStream, TokenTree};
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use rustc_ast::AttrId;
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use rustc_ast::DUMMY_NODE_ID;
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use rustc_ast::{self as ast, AnonConst, AttrStyle, AttrVec, Const, CrateSugar, Extern};
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use rustc_ast::{Async, Expr, ExprKind, MacArgs, MacArgsEq, MacDelimiter, Mutability, StrLit};
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use rustc_ast::{HasAttrs, HasTokens, Unsafe, Visibility, VisibilityKind};
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use rustc_ast_pretty::pprust;
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use rustc_data_structures::fx::FxHashMap;
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use rustc_errors::PResult;
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use rustc_errors::{
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struct_span_err, Applicability, DiagnosticBuilder, ErrorGuaranteed, FatalError, MultiSpan,
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};
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use rustc_session::parse::ParseSess;
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use rustc_span::source_map::{Span, DUMMY_SP};
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use rustc_span::symbol::{kw, sym, Ident, Symbol};
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use tracing::debug;
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use std::ops::Range;
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use std::{cmp, mem, slice};
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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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const CONST_EXPR = 1 << 2;
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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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/// Whether or not we should force collection of tokens for an AST node,
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/// regardless of whether or not it has attributes
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#[derive(Clone, Copy, PartialEq)]
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pub enum ForceCollect {
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Yes,
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No,
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}
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#[derive(Debug, Eq, PartialEq)]
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pub enum TrailingToken {
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None,
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Semi,
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/// If the trailing token is a comma, then capture it
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/// Otherwise, ignore the trailing token
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MaybeComma,
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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
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&& $self.look_ahead(1, |t| t == &token::ModSep)
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&& let token::Interpolated(nt) = &$self.token.kind
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&& let token::NtTy(ty) = &**nt
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{
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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_token.span, ty);
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}
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};
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}
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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 token.
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pub token: Token,
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/// The spacing for the current token
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pub token_spacing: Spacing,
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/// The previous token.
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pub prev_token: Token,
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pub capture_cfg: bool,
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restrictions: Restrictions,
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expected_tokens: Vec<TokenType>,
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// Important: This must only be advanced from `bump` to ensure that
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// `token_cursor.num_next_calls` is updated properly.
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token_cursor: TokenCursor,
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desugar_doc_comments: 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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/// Span pointing at the `:` for the last type ascription the parser has seen, and whether it
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/// looked like it could have been a mistyped path or literal `Option:Some(42)`).
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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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capture_state: CaptureState,
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/// This allows us to recover when the user forget to add braces around
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/// multiple statements in the closure body.
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pub current_closure: Option<ClosureSpans>,
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}
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// This type is used a lot, e.g. it's cloned when matching many declarative macro rules. Make sure
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// it doesn't unintentionally get bigger.
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#[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))]
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rustc_data_structures::static_assert_size!(Parser<'_>, 328);
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/// Stores span information about a closure.
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#[derive(Clone)]
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pub struct ClosureSpans {
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pub whole_closure: Span,
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pub closing_pipe: Span,
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pub body: Span,
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}
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/// Indicates a range of tokens that should be replaced by
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/// the tokens in the provided vector. This is used in two
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/// places during token collection:
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///
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/// 1. During the parsing of an AST node that may have a `#[derive]`
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/// attribute, we parse a nested AST node that has `#[cfg]` or `#[cfg_attr]`
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/// In this case, we use a `ReplaceRange` to replace the entire inner AST node
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/// with `FlatToken::AttrTarget`, allowing us to perform eager cfg-expansion
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/// on an `AttrAnnotatedTokenStream`
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///
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/// 2. When we parse an inner attribute while collecting tokens. We
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/// remove inner attributes from the token stream entirely, and
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/// instead track them through the `attrs` field on the AST node.
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/// This allows us to easily manipulate them (for example, removing
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/// the first macro inner attribute to invoke a proc-macro).
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/// When create a `TokenStream`, the inner attributes get inserted
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/// into the proper place in the token stream.
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pub type ReplaceRange = (Range<u32>, Vec<(FlatToken, Spacing)>);
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/// Controls how we capture tokens. Capturing can be expensive,
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/// so we try to avoid performing capturing in cases where
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/// we will never need an `AttrAnnotatedTokenStream`
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#[derive(Copy, Clone)]
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pub enum Capturing {
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/// We aren't performing any capturing - this is the default mode.
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No,
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/// We are capturing tokens
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Yes,
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}
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#[derive(Clone)]
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struct CaptureState {
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capturing: Capturing,
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replace_ranges: Vec<ReplaceRange>,
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inner_attr_ranges: FxHashMap<AttrId, ReplaceRange>,
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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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// The current (innermost) frame. `frame` and `stack` could be combined,
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// but it's faster to have them separately to access `frame` directly
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// rather than via something like `stack.last().unwrap()` or
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// `stack[stack.len() - 1]`.
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frame: TokenCursorFrame,
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// Additional frames that enclose `frame`.
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stack: Vec<TokenCursorFrame>,
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desugar_doc_comments: bool,
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// Counts the number of calls to `{,inlined_}next`.
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num_next_calls: usize,
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// During parsing, we may sometimes need to 'unglue' a
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// glued token into two component tokens
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// (e.g. '>>' into '>' and '>), so that the parser
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// can consume them one at a time. This process
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// bypasses the normal capturing mechanism
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// (e.g. `num_next_calls` will not be incremented),
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// since the 'unglued' tokens due not exist in
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// the original `TokenStream`.
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//
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// If we end up consuming both unglued tokens,
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// then this is not an issue - we'll end up
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// capturing the single 'glued' token.
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//
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// However, in certain circumstances, we may
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// want to capture just the first 'unglued' token.
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// For example, capturing the `Vec<u8>`
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// in `Option<Vec<u8>>` requires us to unglue
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// the trailing `>>` token. The `break_last_token`
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// field is used to track this token - it gets
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// appended to the captured stream when
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// we evaluate a `LazyTokenStream`
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break_last_token: bool,
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}
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#[derive(Clone)]
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struct TokenCursorFrame {
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delim_sp: Option<(Delimiter, DelimSpan)>,
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tree_cursor: tokenstream::Cursor,
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}
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impl TokenCursorFrame {
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fn new(delim_sp: Option<(Delimiter, DelimSpan)>, tts: TokenStream) -> Self {
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TokenCursorFrame { delim_sp, tree_cursor: tts.into_trees() }
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}
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}
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impl TokenCursor {
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fn next(&mut self, desugar_doc_comments: bool) -> (Token, Spacing) {
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self.inlined_next(desugar_doc_comments)
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}
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/// This always-inlined version should only be used on hot code paths.
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#[inline(always)]
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fn inlined_next(&mut self, desugar_doc_comments: bool) -> (Token, Spacing) {
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loop {
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// FIXME: we currently don't return `Delimiter` open/close delims. To fix #67062 we will
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// need to, whereupon the `delim != Delimiter::Invisible` conditions below can be
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// removed.
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if let Some((tree, spacing)) = self.frame.tree_cursor.next_with_spacing_ref() {
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match tree {
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&TokenTree::Token(ref token) => match (desugar_doc_comments, token) {
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(true, &Token { kind: token::DocComment(_, attr_style, data), span }) => {
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return self.desugar(attr_style, data, span);
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}
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_ => return (token.clone(), *spacing),
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},
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&TokenTree::Delimited(sp, delim, ref tts) => {
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// Set `open_delim` to true here because we deal with it immediately.
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let frame = TokenCursorFrame::new(Some((delim, sp)), tts.clone());
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self.stack.push(mem::replace(&mut self.frame, frame));
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if delim != Delimiter::Invisible {
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return (Token::new(token::OpenDelim(delim), sp.open), Spacing::Alone);
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}
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// No open delimeter to return; continue on to the next iteration.
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}
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};
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} else if let Some(frame) = self.stack.pop() {
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if let Some((delim, span)) = self.frame.delim_sp && delim != Delimiter::Invisible {
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self.frame = frame;
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return (Token::new(token::CloseDelim(delim), span.close), Spacing::Alone);
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}
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self.frame = frame;
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// No close delimiter to return; continue on to the next iteration.
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} else {
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return (Token::new(token::Eof, DUMMY_SP), Spacing::Alone);
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}
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}
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}
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fn desugar(&mut self, attr_style: AttrStyle, data: Symbol, span: Span) -> (Token, Spacing) {
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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 data.as_str().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(span);
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let body = TokenTree::Delimited(
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delim_span,
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Delimiter::Bracket,
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[
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TokenTree::token(token::Ident(sym::doc, false), span),
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TokenTree::token(token::Eq, span),
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TokenTree::token(TokenKind::lit(token::StrRaw(num_of_hashes), data, None), span),
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]
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.iter()
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.cloned()
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.collect::<TokenStream>(),
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);
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self.stack.push(mem::replace(
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&mut self.frame,
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TokenCursorFrame::new(
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None,
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if attr_style == AttrStyle::Inner {
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[TokenTree::token(token::Pound, span), TokenTree::token(token::Not, span), body]
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.iter()
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.cloned()
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.collect::<TokenStream>()
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} else {
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[TokenTree::token(token::Pound, span), body]
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.iter()
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.cloned()
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.collect::<TokenStream>()
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},
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),
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));
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self.next(/* desugar_doc_comments */ false)
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}
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}
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#[derive(Debug, 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 => "a const expression".to_string(),
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}
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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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|
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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 { sep: Some(t), trailing_sep_allowed: true }
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}
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|
|
|
fn none() -> SeqSep {
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SeqSep { sep: None, trailing_sep_allowed: false }
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}
|
|
}
|
|
|
|
pub enum FollowedByType {
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Yes,
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No,
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|
}
|
|
|
|
fn token_descr_opt(token: &Token) -> Option<&'static str> {
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Some(match token.kind {
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_ if token.is_special_ident() => "reserved identifier",
|
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_ if token.is_used_keyword() => "keyword",
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|
_ if 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 token_descr(token: &Token) -> String {
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let token_str = pprust::token_to_string(token);
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match token_descr_opt(token) {
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Some(prefix) => format!("{} `{}`", prefix, token_str),
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|
_ => format!("`{}`", token_str),
|
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}
|
|
}
|
|
|
|
impl<'a> Parser<'a> {
|
|
pub fn new(
|
|
sess: &'a ParseSess,
|
|
tokens: TokenStream,
|
|
desugar_doc_comments: bool,
|
|
subparser_name: Option<&'static str>,
|
|
) -> 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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|
token_spacing: Spacing::Alone,
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|
prev_token: Token::dummy(),
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|
capture_cfg: false,
|
|
restrictions: Restrictions::empty(),
|
|
expected_tokens: Vec::new(),
|
|
token_cursor: TokenCursor {
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|
frame: TokenCursorFrame::new(None, tokens),
|
|
stack: Vec::new(),
|
|
num_next_calls: 0,
|
|
desugar_doc_comments,
|
|
break_last_token: false,
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|
},
|
|
desugar_doc_comments,
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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,
|
|
subparser_name,
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|
capture_state: CaptureState {
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|
capturing: Capturing::No,
|
|
replace_ranges: Vec::new(),
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|
inner_attr_ranges: Default::default(),
|
|
},
|
|
current_closure: None,
|
|
};
|
|
|
|
// Make parser point to the first token.
|
|
parser.bump();
|
|
|
|
parser
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|
}
|
|
|
|
pub fn unexpected<T>(&mut self) -> PResult<'a, T> {
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|
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();
|
|
Ok(false)
|
|
} else {
|
|
self.unexpected_try_recover(t)
|
|
}
|
|
} 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(
|
|
&mut self,
|
|
edible: &[TokenKind],
|
|
inedible: &[TokenKind],
|
|
) -> PResult<'a, bool /* recovered */> {
|
|
if edible.contains(&self.token.kind) {
|
|
self.bump();
|
|
Ok(false)
|
|
} else if inedible.contains(&self.token.kind) {
|
|
// leave it in the input
|
|
Ok(false)
|
|
} else if self.last_unexpected_token_span == Some(self.token.span) {
|
|
FatalError.raise();
|
|
} else {
|
|
self.expected_one_of_not_found(edible, inedible)
|
|
}
|
|
}
|
|
|
|
// Public for rustfmt usage.
|
|
pub fn parse_ident(&mut self) -> PResult<'a, Ident> {
|
|
self.parse_ident_common(true)
|
|
}
|
|
|
|
fn ident_or_err(&mut self) -> PResult<'a, (Ident, /* is_raw */ bool)> {
|
|
self.token.ident().ok_or_else(|| match self.prev_token.kind {
|
|
TokenKind::DocComment(..) => {
|
|
self.span_err(self.prev_token.span, Error::UselessDocComment)
|
|
}
|
|
_ => self.expected_ident_found(),
|
|
})
|
|
}
|
|
|
|
fn parse_ident_common(&mut self, recover: bool) -> PResult<'a, Ident> {
|
|
let (ident, is_raw) = self.ident_or_err()?;
|
|
if !is_raw && ident.is_reserved() {
|
|
let mut err = self.expected_ident_found();
|
|
if recover {
|
|
err.emit();
|
|
} else {
|
|
return Err(err);
|
|
}
|
|
}
|
|
self.bump();
|
|
Ok(ident)
|
|
}
|
|
|
|
/// 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.
|
|
// Public for rustfmt usage.
|
|
pub 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(()) }
|
|
}
|
|
|
|
/// Is the given keyword `kw` followed by a non-reserved identifier?
|
|
fn is_kw_followed_by_ident(&self, kw: Symbol) -> bool {
|
|
self.token.is_keyword(kw) && self.look_ahead(1, |t| t.is_ident() && !t.is_reserved_ident())
|
|
}
|
|
|
|
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)
|
|
}
|
|
|
|
fn check_inline_const(&self, dist: usize) -> bool {
|
|
self.is_keyword_ahead(dist, &[kw::Const])
|
|
&& self.look_ahead(dist + 1, |t| match t.kind {
|
|
token::Interpolated(ref nt) => matches!(**nt, token::NtBlock(..)),
|
|
token::OpenDelim(Delimiter::Brace) => true,
|
|
_ => false,
|
|
})
|
|
}
|
|
|
|
/// 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)),
|
|
)
|
|
}
|
|
|
|
/// Eats the expected token if it's present possibly breaking
|
|
/// compound tokens like multi-character operators in process.
|
|
/// Returns `true` if the token was eaten.
|
|
fn break_and_eat(&mut self, expected: TokenKind) -> bool {
|
|
if self.token.kind == expected {
|
|
self.bump();
|
|
return true;
|
|
}
|
|
match self.token.kind.break_two_token_op() {
|
|
Some((first, second)) if first == expected => {
|
|
let first_span = self.sess.source_map().start_point(self.token.span);
|
|
let second_span = self.token.span.with_lo(first_span.hi());
|
|
self.token = Token::new(first, first_span);
|
|
// Keep track of this token - if we end token capturing now,
|
|
// we'll want to append this token to the captured stream.
|
|
//
|
|
// If we consume any additional tokens, then this token
|
|
// is not needed (we'll capture the entire 'glued' token),
|
|
// and `bump` will set this field to `None`
|
|
self.token_cursor.break_last_token = true;
|
|
// Use the spacing of the glued token as the spacing
|
|
// of the unglued second token.
|
|
self.bump_with((Token::new(second, second_span), self.token_spacing));
|
|
true
|
|
}
|
|
_ => {
|
|
self.expected_tokens.push(TokenType::Token(expected));
|
|
false
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Eats `+` possibly breaking tokens like `+=` in process.
|
|
fn eat_plus(&mut self) -> bool {
|
|
self.break_and_eat(token::BinOp(token::Plus))
|
|
}
|
|
|
|
/// Eats `&` possibly breaking tokens like `&&` in process.
|
|
/// Signals an error if `&` is not eaten.
|
|
fn expect_and(&mut self) -> PResult<'a, ()> {
|
|
if self.break_and_eat(token::BinOp(token::And)) { Ok(()) } else { self.unexpected() }
|
|
}
|
|
|
|
/// Eats `|` possibly breaking tokens like `||` in process.
|
|
/// Signals an error if `|` was not eaten.
|
|
fn expect_or(&mut self) -> PResult<'a, ()> {
|
|
if self.break_and_eat(token::BinOp(token::Or)) { Ok(()) } else { self.unexpected() }
|
|
}
|
|
|
|
/// Eats `<` possibly breaking tokens like `<<` in process.
|
|
fn eat_lt(&mut self) -> bool {
|
|
let ate = self.break_and_eat(token::Lt);
|
|
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
|
|
}
|
|
|
|
/// Eats `<` possibly breaking tokens like `<<` in process.
|
|
/// Signals an error if `<` was not eaten.
|
|
fn expect_lt(&mut self) -> PResult<'a, ()> {
|
|
if self.eat_lt() { Ok(()) } else { self.unexpected() }
|
|
}
|
|
|
|
/// Eats `>` possibly breaking tokens like `>>` in process.
|
|
/// Signals an error if `>` was not eaten.
|
|
fn expect_gt(&mut self) -> PResult<'a, ()> {
|
|
if self.break_and_eat(token::Gt) {
|
|
// 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(())
|
|
} else {
|
|
self.unexpected()
|
|
}
|
|
}
|
|
|
|
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![];
|
|
let unclosed_delims = !self.unclosed_delims.is_empty();
|
|
|
|
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) => {
|
|
self.current_closure.take();
|
|
}
|
|
Ok(true) => {
|
|
self.current_closure.take();
|
|
recovered = true;
|
|
break;
|
|
}
|
|
Err(mut expect_err) => {
|
|
let sp = self.prev_token.span.shrink_to_hi();
|
|
let token_str = pprust::token_kind_to_string(t);
|
|
|
|
match self.current_closure.take() {
|
|
Some(closure_spans) if self.token.kind == TokenKind::Semi => {
|
|
// Finding a semicolon instead of a comma
|
|
// after a closure body indicates that the
|
|
// closure body may be a block but the user
|
|
// forgot to put braces around its
|
|
// statements.
|
|
|
|
self.recover_missing_braces_around_closure_body(
|
|
closure_spans,
|
|
expect_err,
|
|
)?;
|
|
|
|
continue;
|
|
}
|
|
|
|
_ => {
|
|
// Attempt to keep parsing if it was a similar separator.
|
|
if let Some(ref tokens) = t.similar_tokens() {
|
|
if tokens.contains(&self.token.kind) && !unclosed_delims {
|
|
self.bump();
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
// If this was a missing `@` in a binding pattern
|
|
// bail with a suggestion
|
|
// https://github.com/rust-lang/rust/issues/72373
|
|
if self.prev_token.is_ident() && self.token.kind == token::DotDot {
|
|
let msg = format!(
|
|
"if you meant to bind the contents of \
|
|
the rest of the array pattern into `{}`, use `@`",
|
|
pprust::token_to_string(&self.prev_token)
|
|
);
|
|
expect_err
|
|
.span_suggestion_verbose(
|
|
self.prev_token.span.shrink_to_hi().until(self.token.span),
|
|
&msg,
|
|
" @ ",
|
|
Applicability::MaybeIncorrect,
|
|
)
|
|
.emit();
|
|
break;
|
|
}
|
|
|
|
// 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(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))
|
|
}
|
|
|
|
fn recover_missing_braces_around_closure_body(
|
|
&mut self,
|
|
closure_spans: ClosureSpans,
|
|
mut expect_err: DiagnosticBuilder<'_, ErrorGuaranteed>,
|
|
) -> PResult<'a, ()> {
|
|
let initial_semicolon = self.token.span;
|
|
|
|
while self.eat(&TokenKind::Semi) {
|
|
let _ = self.parse_stmt(ForceCollect::Yes)?;
|
|
}
|
|
|
|
expect_err.set_primary_message(
|
|
"closure bodies that contain statements must be surrounded by braces",
|
|
);
|
|
|
|
let preceding_pipe_span = closure_spans.closing_pipe;
|
|
let following_token_span = self.token.span;
|
|
|
|
let mut first_note = MultiSpan::from(vec![initial_semicolon]);
|
|
first_note.push_span_label(
|
|
initial_semicolon,
|
|
"this `;` turns the preceding closure into a statement".to_string(),
|
|
);
|
|
first_note.push_span_label(
|
|
closure_spans.body,
|
|
"this expression is a statement because of the trailing semicolon".to_string(),
|
|
);
|
|
expect_err.span_note(first_note, "statement found outside of a block");
|
|
|
|
let mut second_note = MultiSpan::from(vec![closure_spans.whole_closure]);
|
|
second_note.push_span_label(
|
|
closure_spans.whole_closure,
|
|
"this is the parsed closure...".to_string(),
|
|
);
|
|
second_note.push_span_label(
|
|
following_token_span,
|
|
"...but likely you meant the closure to end here".to_string(),
|
|
);
|
|
expect_err.span_note(second_note, "the closure body may be incorrectly delimited");
|
|
|
|
expect_err.set_span(vec![preceding_pipe_span, following_token_span]);
|
|
|
|
let opening_suggestion_str = " {".to_string();
|
|
let closing_suggestion_str = "}".to_string();
|
|
|
|
expect_err.multipart_suggestion(
|
|
"try adding braces",
|
|
vec![
|
|
(preceding_pipe_span.shrink_to_hi(), opening_suggestion_str),
|
|
(following_token_span.shrink_to_lo(), closing_suggestion_str),
|
|
],
|
|
Applicability::MaybeIncorrect,
|
|
);
|
|
|
|
expect_err.emit();
|
|
|
|
Ok(())
|
|
}
|
|
|
|
/// 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)
|
|
}
|
|
|
|
/// 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>, bool /* trailing */)> {
|
|
let (val, trailing, recovered) = self.parse_seq_to_before_end(ket, sep, f)?;
|
|
if !recovered {
|
|
self.eat(ket);
|
|
}
|
|
Ok((val, trailing))
|
|
}
|
|
|
|
/// 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)?;
|
|
self.parse_seq_to_end(ket, sep, f)
|
|
}
|
|
|
|
fn parse_delim_comma_seq<T>(
|
|
&mut self,
|
|
delim: Delimiter,
|
|
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(Delimiter::Parenthesis, f)
|
|
}
|
|
|
|
/// Advance the parser by one token using provided token as the next one.
|
|
fn bump_with(&mut self, next: (Token, Spacing)) {
|
|
self.inlined_bump_with(next)
|
|
}
|
|
|
|
/// This always-inlined version should only be used on hot code paths.
|
|
#[inline(always)]
|
|
fn inlined_bump_with(&mut self, (next_token, next_spacing): (Token, Spacing)) {
|
|
// Update the current and previous tokens.
|
|
self.prev_token = mem::replace(&mut self.token, next_token);
|
|
self.token_spacing = next_spacing;
|
|
|
|
// Diagnostics.
|
|
self.expected_tokens.clear();
|
|
}
|
|
|
|
/// Advance the parser by one token.
|
|
pub fn bump(&mut self) {
|
|
// Note: destructuring here would give nicer code, but it was found in #96210 to be slower
|
|
// than `.0`/`.1` access.
|
|
let mut next = self.token_cursor.inlined_next(self.desugar_doc_comments);
|
|
self.token_cursor.num_next_calls += 1;
|
|
// We've retrieved an token from the underlying
|
|
// cursor, so we no longer need to worry about
|
|
// an unglued token. See `break_and_eat` for more details
|
|
self.token_cursor.break_last_token = false;
|
|
if next.0.span.is_dummy() {
|
|
// Tweak the location for better diagnostics, but keep syntactic context intact.
|
|
let fallback_span = self.token.span;
|
|
next.0.span = fallback_span.with_ctxt(next.0.span.ctxt());
|
|
}
|
|
debug_assert!(!matches!(
|
|
next.0.kind,
|
|
token::OpenDelim(Delimiter::Invisible) | token::CloseDelim(Delimiter::Invisible)
|
|
));
|
|
self.inlined_bump_with(next)
|
|
}
|
|
|
|
/// 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;
|
|
if let Some((delim, span)) = frame.delim_sp && delim != Delimiter::Invisible {
|
|
let all_normal = (0..dist).all(|i| {
|
|
let token = frame.tree_cursor.look_ahead(i);
|
|
!matches!(token, Some(TokenTree::Delimited(_, Delimiter::Invisible, _)))
|
|
});
|
|
if all_normal {
|
|
return match frame.tree_cursor.look_ahead(dist - 1) {
|
|
Some(tree) => match tree {
|
|
TokenTree::Token(token) => looker(token),
|
|
TokenTree::Delimited(dspan, delim, _) => {
|
|
looker(&Token::new(token::OpenDelim(*delim), dspan.open))
|
|
}
|
|
},
|
|
None => looker(&Token::new(token::CloseDelim(delim), span.close)),
|
|
};
|
|
}
|
|
}
|
|
|
|
let mut cursor = self.token_cursor.clone();
|
|
let mut i = 0;
|
|
let mut token = Token::dummy();
|
|
while i < dist {
|
|
token = cursor.next(/* desugar_doc_comments */ false).0;
|
|
if matches!(
|
|
token.kind,
|
|
token::OpenDelim(Delimiter::Invisible) | token::CloseDelim(Delimiter::Invisible)
|
|
) {
|
|
continue;
|
|
}
|
|
i += 1;
|
|
}
|
|
return looker(&token);
|
|
}
|
|
|
|
/// 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) -> Async {
|
|
if self.eat_keyword(kw::Async) {
|
|
let span = self.prev_token.uninterpolated_span();
|
|
Async::Yes { span, closure_id: DUMMY_NODE_ID, return_impl_trait_id: DUMMY_NODE_ID }
|
|
} else {
|
|
Async::No
|
|
}
|
|
}
|
|
|
|
/// Parses unsafety: `unsafe` or nothing.
|
|
fn parse_unsafety(&mut self) -> Unsafe {
|
|
if self.eat_keyword(kw::Unsafe) {
|
|
Unsafe::Yes(self.prev_token.uninterpolated_span())
|
|
} else {
|
|
Unsafe::No
|
|
}
|
|
}
|
|
|
|
/// Parses constness: `const` or nothing.
|
|
fn parse_constness(&mut self) -> Const {
|
|
// Avoid const blocks to be parsed as const items
|
|
if self.look_ahead(1, |t| t != &token::OpenDelim(Delimiter::Brace))
|
|
&& self.eat_keyword(kw::Const)
|
|
{
|
|
Const::Yes(self.prev_token.uninterpolated_span())
|
|
} else {
|
|
Const::No
|
|
}
|
|
}
|
|
|
|
/// Parses inline const expressions.
|
|
fn parse_const_block(&mut self, span: Span, pat: bool) -> PResult<'a, P<Expr>> {
|
|
if pat {
|
|
self.sess.gated_spans.gate(sym::inline_const_pat, span);
|
|
} else {
|
|
self.sess.gated_spans.gate(sym::inline_const, span);
|
|
}
|
|
self.eat_keyword(kw::Const);
|
|
let (attrs, blk) = self.parse_inner_attrs_and_block()?;
|
|
let anon_const = AnonConst {
|
|
id: DUMMY_NODE_ID,
|
|
value: self.mk_expr(blk.span, ExprKind::Block(blk, None), AttrVec::new()),
|
|
};
|
|
let blk_span = anon_const.value.span;
|
|
Ok(self.mk_expr(span.to(blk_span), ExprKind::ConstBlock(anon_const), AttrVec::from(attrs)))
|
|
}
|
|
|
|
/// Parses mutability (`mut` or nothing).
|
|
fn parse_mutability(&mut self) -> Mutability {
|
|
if self.eat_keyword(kw::Mut) { Mutability::Mut } else { Mutability::Not }
|
|
}
|
|
|
|
/// Possibly parses mutability (`const` or `mut`).
|
|
fn parse_const_or_mut(&mut self) -> Option<Mutability> {
|
|
if self.eat_keyword(kw::Mut) {
|
|
Some(Mutability::Mut)
|
|
} else if self.eat_keyword(kw::Const) {
|
|
Some(Mutability::Not)
|
|
} 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_token.span))
|
|
} else {
|
|
self.parse_ident_common(true)
|
|
}
|
|
}
|
|
|
|
fn parse_mac_args(&mut self) -> PResult<'a, P<MacArgs>> {
|
|
self.parse_mac_args_common(true).map(P)
|
|
}
|
|
|
|
fn parse_attr_args(&mut self) -> PResult<'a, MacArgs> {
|
|
self.parse_mac_args_common(false)
|
|
}
|
|
|
|
fn parse_mac_args_common(&mut self, delimited_only: bool) -> PResult<'a, MacArgs> {
|
|
Ok(
|
|
if self.check(&token::OpenDelim(Delimiter::Parenthesis))
|
|
|| self.check(&token::OpenDelim(Delimiter::Bracket))
|
|
|| self.check(&token::OpenDelim(Delimiter::Brace))
|
|
{
|
|
match self.parse_token_tree() {
|
|
TokenTree::Delimited(dspan, delim, tokens) =>
|
|
// We've confirmed above that there is a delimiter so unwrapping is OK.
|
|
{
|
|
MacArgs::Delimited(dspan, MacDelimiter::from_token(delim).unwrap(), tokens)
|
|
}
|
|
_ => unreachable!(),
|
|
}
|
|
} else if !delimited_only {
|
|
if self.eat(&token::Eq) {
|
|
let eq_span = self.prev_token.span;
|
|
MacArgs::Eq(eq_span, MacArgsEq::Ast(self.parse_expr_force_collect()?))
|
|
} else {
|
|
MacArgs::Empty
|
|
}
|
|
} else {
|
|
return self.unexpected();
|
|
},
|
|
)
|
|
}
|
|
|
|
fn parse_or_use_outer_attributes(
|
|
&mut self,
|
|
already_parsed_attrs: Option<AttrWrapper>,
|
|
) -> PResult<'a, AttrWrapper> {
|
|
if let Some(attrs) = already_parsed_attrs {
|
|
Ok(attrs)
|
|
} else {
|
|
self.parse_outer_attributes()
|
|
}
|
|
}
|
|
|
|
/// Parses a single token tree from the input.
|
|
pub(crate) fn parse_token_tree(&mut self) -> TokenTree {
|
|
match self.token.kind {
|
|
token::OpenDelim(..) => {
|
|
// Grab the tokens from this frame.
|
|
let frame = &self.token_cursor.frame;
|
|
let stream = frame.tree_cursor.stream.clone();
|
|
let (delim, span) = frame.delim_sp.unwrap();
|
|
|
|
// Advance the token cursor through the entire delimited
|
|
// sequence. After getting the `OpenDelim` we are *within* the
|
|
// delimited sequence, i.e. at depth `d`. After getting the
|
|
// matching `CloseDelim` we are *after* the delimited sequence,
|
|
// i.e. at depth `d - 1`.
|
|
let target_depth = self.token_cursor.stack.len() - 1;
|
|
loop {
|
|
// Advance one token at a time, so `TokenCursor::next()`
|
|
// can capture these tokens if necessary.
|
|
self.bump();
|
|
if self.token_cursor.stack.len() == target_depth {
|
|
debug_assert!(matches!(self.token.kind, token::CloseDelim(_)));
|
|
break;
|
|
}
|
|
}
|
|
|
|
// Consume close delimiter
|
|
self.bump();
|
|
TokenTree::Delimited(span, delim, stream)
|
|
}
|
|
token::CloseDelim(_) | token::Eof => unreachable!(),
|
|
_ => {
|
|
self.bump();
|
|
TokenTree::Token(self.prev_token.clone())
|
|
}
|
|
}
|
|
}
|
|
|
|
/// 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 aren't valid,
|
|
/// so emit a proper diagnostic.
|
|
// Public for rustfmt usage.
|
|
pub fn parse_visibility(&mut self, fbt: FollowedByType) -> PResult<'a, Visibility> {
|
|
maybe_whole!(self, NtVis, |x| x.into_inner());
|
|
|
|
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_token.span);
|
|
return Ok(Visibility {
|
|
span: self.prev_token.span,
|
|
kind: VisibilityKind::Crate(CrateSugar::JustCrate),
|
|
tokens: None,
|
|
});
|
|
}
|
|
|
|
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(Visibility {
|
|
span: self.token.span.shrink_to_lo(),
|
|
kind: VisibilityKind::Inherited,
|
|
tokens: None,
|
|
});
|
|
}
|
|
let lo = self.prev_token.span;
|
|
|
|
if self.check(&token::OpenDelim(Delimiter::Parenthesis)) {
|
|
// 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(Delimiter::Parenthesis))?; // `)`
|
|
let vis = VisibilityKind::Crate(CrateSugar::PubCrate);
|
|
return Ok(Visibility {
|
|
span: lo.to(self.prev_token.span),
|
|
kind: vis,
|
|
tokens: None,
|
|
});
|
|
} 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(Delimiter::Parenthesis))?; // `)`
|
|
let vis = VisibilityKind::Restricted { path: P(path), id: ast::DUMMY_NODE_ID };
|
|
return Ok(Visibility {
|
|
span: lo.to(self.prev_token.span),
|
|
kind: vis,
|
|
tokens: None,
|
|
});
|
|
} else if self.look_ahead(2, |t| t == &token::CloseDelim(Delimiter::Parenthesis))
|
|
&& 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(Delimiter::Parenthesis))?; // `)`
|
|
let vis = VisibilityKind::Restricted { path: P(path), id: ast::DUMMY_NODE_ID };
|
|
return Ok(Visibility {
|
|
span: lo.to(self.prev_token.span),
|
|
kind: vis,
|
|
tokens: None,
|
|
});
|
|
} 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(Visibility { span: lo, kind: VisibilityKind::Public, tokens: None })
|
|
}
|
|
|
|
/// 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(Delimiter::Parenthesis))?; // `)`
|
|
|
|
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) -> Extern {
|
|
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,
|
|
}
|
|
}
|
|
|
|
pub fn collect_tokens_no_attrs<R: HasAttrs + HasTokens>(
|
|
&mut self,
|
|
f: impl FnOnce(&mut Self) -> PResult<'a, R>,
|
|
) -> PResult<'a, R> {
|
|
// The only reason to call `collect_tokens_no_attrs` is if you want tokens, so use
|
|
// `ForceCollect::Yes`
|
|
self.collect_tokens_trailing_token(
|
|
AttrWrapper::empty(),
|
|
ForceCollect::Yes,
|
|
|this, _attrs| Ok((f(this)?, TrailingToken::None)),
|
|
)
|
|
}
|
|
|
|
/// `::{` or `::*`
|
|
fn is_import_coupler(&mut self) -> bool {
|
|
self.check(&token::ModSep)
|
|
&& self.look_ahead(1, |t| {
|
|
*t == token::OpenDelim(Delimiter::Brace) || *t == token::BinOp(token::Star)
|
|
})
|
|
}
|
|
|
|
pub fn clear_expected_tokens(&mut self) {
|
|
self.expected_tokens.clear();
|
|
}
|
|
}
|
|
|
|
crate fn make_unclosed_delims_error(
|
|
unmatched: UnmatchedBrace,
|
|
sess: &ParseSess,
|
|
) -> Option<DiagnosticBuilder<'_, ErrorGuaranteed>> {
|
|
// `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 span: MultiSpan = if let Some(sp) = unmatched.unclosed_span {
|
|
vec![unmatched.found_span, sp].into()
|
|
} else {
|
|
unmatched.found_span.into()
|
|
};
|
|
let mut err = sess.span_diagnostic.struct_span_err(
|
|
span,
|
|
&format!(
|
|
"mismatched closing delimiter: `{}`",
|
|
pprust::token_kind_to_string(&token::CloseDelim(found_delim)),
|
|
),
|
|
);
|
|
err.span_label(unmatched.found_span, "mismatched closing delimiter");
|
|
if let Some(sp) = unmatched.candidate_span {
|
|
err.span_label(sp, "closing delimiter possibly meant for this");
|
|
}
|
|
if let Some(sp) = unmatched.unclosed_span {
|
|
err.span_label(sp, "unclosed 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(..) {
|
|
if let Some(mut e) = make_unclosed_delims_error(unmatched, sess) {
|
|
e.emit();
|
|
}
|
|
}
|
|
}
|
|
|
|
/// A helper struct used when building an `AttrAnnotatedTokenStream` from
|
|
/// a `LazyTokenStream`. Both delimiter and non-delimited tokens
|
|
/// are stored as `FlatToken::Token`. A vector of `FlatToken`s
|
|
/// is then 'parsed' to build up an `AttrAnnotatedTokenStream` with nested
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/// `AttrAnnotatedTokenTree::Delimited` tokens
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#[derive(Debug, Clone)]
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|
pub enum FlatToken {
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|
/// A token - this holds both delimiter (e.g. '{' and '}')
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|
/// and non-delimiter tokens
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|
Token(Token),
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|
/// Holds the `AttributesData` for an AST node. The
|
|
/// `AttributesData` is inserted directly into the
|
|
/// constructed `AttrAnnotatedTokenStream` as
|
|
/// an `AttrAnnotatedTokenTree::Attributes`
|
|
AttrTarget(AttributesData),
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|
/// A special 'empty' token that is ignored during the conversion
|
|
/// to an `AttrAnnotatedTokenStream`. This is used to simplify the
|
|
/// handling of replace ranges.
|
|
Empty,
|
|
}
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|
|
|
#[derive(Debug)]
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|
pub enum NtOrTt {
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|
Nt(Nonterminal),
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|
Tt(TokenTree),
|
|
}
|