diff options
Diffstat (limited to 'src/libsyntax/parse/parser.rs')
| -rw-r--r-- | src/libsyntax/parse/parser.rs | 401 |
1 files changed, 70 insertions, 331 deletions
diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs index 4a457f5a43c..2ce0046ca27 100644 --- a/src/libsyntax/parse/parser.rs +++ b/src/libsyntax/parse/parser.rs @@ -1,28 +1,28 @@ +pub mod attr; mod expr; mod pat; mod item; -pub use item::AliasKind; mod module; -pub use module::{ModulePath, ModulePathSuccess}; mod ty; mod path; pub use path::PathStyle; mod stmt; mod generics; +mod diagnostics; +use diagnostics::Error; use crate::ast::{ - self, DUMMY_NODE_ID, AttrStyle, Attribute, BindingMode, CrateSugar, Ident, - IsAsync, MacDelimiter, Mutability, Param, StrStyle, SelfKind, TyKind, Visibility, - VisibilityKind, Unsafety, + self, DUMMY_NODE_ID, AttrStyle, Attribute, CrateSugar, Ident, + IsAsync, MacDelimiter, Mutability, StrStyle, Visibility, VisibilityKind, Unsafety, }; -use crate::parse::{ParseSess, PResult, Directory, DirectoryOwnership, SeqSep, literal, token}; -use crate::parse::diagnostics::{Error, dummy_arg}; +use crate::parse::{PResult, Directory, DirectoryOwnership}; use crate::parse::lexer::UnmatchedBrace; use crate::parse::lexer::comments::{doc_comment_style, strip_doc_comment_decoration}; -use crate::parse::token::{Token, TokenKind, DelimToken}; +use crate::parse::token::{self, Token, TokenKind, DelimToken}; use crate::print::pprust; use crate::ptr::P; -use crate::source_map::{self, respan}; +use crate::sess::ParseSess; +use crate::source_map::respan; use crate::symbol::{kw, sym, Symbol}; use crate::tokenstream::{self, DelimSpan, TokenTree, TokenStream, TreeAndJoint}; use crate::ThinVec; @@ -44,29 +44,18 @@ bitflags::bitflags! { } #[derive(Clone, Copy, PartialEq, Debug)] -crate enum SemiColonMode { +enum SemiColonMode { Break, Ignore, Comma, } #[derive(Clone, Copy, PartialEq, Debug)] -crate enum BlockMode { +enum BlockMode { Break, Ignore, } -/// The parsing configuration used to parse a parameter list (see `parse_fn_params`). -struct ParamCfg { - /// Is `self` is allowed as the first parameter? - is_self_allowed: bool, - /// Is `...` allowed as the tail of the parameter list? - allow_c_variadic: bool, - /// `is_name_required` decides if, per-parameter, - /// the parameter must have a pattern or just a type. - is_name_required: fn(&token::Token) -> bool, -} - /// Like `maybe_whole_expr`, but for things other than expressions. #[macro_export] macro_rules! maybe_whole { @@ -97,13 +86,6 @@ macro_rules! maybe_recover_from_interpolated_ty_qpath { } } -fn maybe_append(mut lhs: Vec<Attribute>, mut rhs: Option<Vec<Attribute>>) -> Vec<Attribute> { - if let Some(ref mut rhs) = rhs { - lhs.append(rhs); - } - lhs -} - #[derive(Debug, Clone, Copy, PartialEq)] enum PrevTokenKind { DocComment, @@ -135,33 +117,33 @@ pub struct Parser<'a> { prev_token_kind: PrevTokenKind, restrictions: Restrictions, /// Used to determine the path to externally loaded source files. - crate directory: Directory<'a>, + pub(super) directory: Directory<'a>, /// `true` to parse sub-modules in other files. - pub recurse_into_file_modules: bool, + pub(super) recurse_into_file_modules: bool, /// Name of the root module this parser originated from. If `None`, then the /// name is not known. This does not change while the parser is descending /// into modules, and sub-parsers have new values for this name. pub root_module_name: Option<String>, - crate expected_tokens: Vec<TokenType>, + expected_tokens: Vec<TokenType>, token_cursor: TokenCursor, desugar_doc_comments: bool, /// `true` we should configure out of line modules as we parse. - pub cfg_mods: bool, + cfg_mods: bool, /// This field is used to keep track of how many left angle brackets we have seen. This is /// required in order to detect extra leading left angle brackets (`<` characters) and error /// appropriately. /// /// See the comments in the `parse_path_segment` function for more details. - crate unmatched_angle_bracket_count: u32, - crate max_angle_bracket_count: u32, + unmatched_angle_bracket_count: u32, + max_angle_bracket_count: u32, /// A list of all unclosed delimiters found by the lexer. If an entry is used for error recovery /// it gets removed from here. Every entry left at the end gets emitted as an independent /// error. - crate unclosed_delims: Vec<UnmatchedBrace>, - crate last_unexpected_token_span: Option<Span>, - crate last_type_ascription: Option<(Span, bool /* likely path typo */)>, + pub(super) unclosed_delims: Vec<UnmatchedBrace>, + last_unexpected_token_span: Option<Span>, + pub last_type_ascription: Option<(Span, bool /* likely path typo */)>, /// If present, this `Parser` is not parsing Rust code but rather a macro call. - crate subparser_name: Option<&'static str>, + subparser_name: Option<&'static str>, } impl<'a> Drop for Parser<'a> { @@ -205,7 +187,7 @@ struct TokenCursorFrame { /// You can find some more example usage of this in the `collect_tokens` method /// on the parser. #[derive(Clone)] -crate enum LastToken { +enum LastToken { Collecting(Vec<TreeAndJoint>), Was(Option<TreeAndJoint>), } @@ -296,10 +278,10 @@ impl TokenCursor { token::NoDelim, &if doc_comment_style(&name.as_str()) == AttrStyle::Inner { [TokenTree::token(token::Pound, sp), TokenTree::token(token::Not, sp), body] - .iter().cloned().collect::<TokenStream>().into() + .iter().cloned().collect::<TokenStream>() } else { [TokenTree::token(token::Pound, sp), body] - .iter().cloned().collect::<TokenStream>().into() + .iter().cloned().collect::<TokenStream>() }, ))); @@ -308,7 +290,7 @@ impl TokenCursor { } #[derive(Clone, PartialEq)] -crate enum TokenType { +enum TokenType { Token(TokenKind), Keyword(Symbol), Operator, @@ -320,7 +302,7 @@ crate enum TokenType { } impl TokenType { - crate fn to_string(&self) -> String { + fn to_string(&self) -> String { match *self { TokenType::Token(ref t) => format!("`{}`", pprust::token_kind_to_string(t)), TokenType::Keyword(kw) => format!("`{}`", kw), @@ -335,11 +317,35 @@ impl TokenType { } #[derive(Copy, Clone, Debug)] -crate enum TokenExpectType { +enum TokenExpectType { Expect, NoExpect, } +/// A sequence separator. +struct SeqSep { + /// The separator token. + sep: Option<TokenKind>, + /// `true` if a trailing separator is allowed. + trailing_sep_allowed: bool, +} + +impl SeqSep { + fn trailing_allowed(t: TokenKind) -> SeqSep { + SeqSep { + sep: Some(t), + trailing_sep_allowed: true, + } + } + + fn none() -> SeqSep { + SeqSep { + sep: None, + trailing_sep_allowed: false, + } + } +} + impl<'a> Parser<'a> { pub fn new( sess: &'a ParseSess, @@ -416,7 +422,7 @@ impl<'a> Parser<'a> { pprust::token_to_string(&self.token) } - crate fn token_descr(&self) -> Option<&'static str> { + fn token_descr(&self) -> Option<&'static str> { Some(match &self.token.kind { _ if self.token.is_special_ident() => "reserved identifier", _ if self.token.is_used_keyword() => "keyword", @@ -426,7 +432,7 @@ impl<'a> Parser<'a> { }) } - crate fn this_token_descr(&self) -> String { + pub(super) fn this_token_descr(&self) -> String { if let Some(prefix) = self.token_descr() { format!("{} `{}`", prefix, self.this_token_to_string()) } else { @@ -476,7 +482,7 @@ impl<'a> Parser<'a> { } } - pub fn parse_ident(&mut self) -> PResult<'a, ast::Ident> { + fn parse_ident(&mut self) -> PResult<'a, ast::Ident> { self.parse_ident_common(true) } @@ -509,7 +515,7 @@ impl<'a> Parser<'a> { /// /// This method will automatically add `tok` to `expected_tokens` if `tok` is not /// encountered. - crate fn check(&mut self, tok: &TokenKind) -> bool { + 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 @@ -531,7 +537,7 @@ impl<'a> Parser<'a> { /// If the next token is the given keyword, eats it and returns `true`. /// Otherwise, returns `false`. An expectation is also added for diagnostics purposes. - pub fn eat_keyword(&mut self, kw: Symbol) -> bool { + fn eat_keyword(&mut self, kw: Symbol) -> bool { if self.check_keyword(kw) { self.bump(); true @@ -569,7 +575,7 @@ impl<'a> Parser<'a> { } } - crate fn check_ident(&mut self) -> bool { + fn check_ident(&mut self) -> bool { self.check_or_expected(self.token.is_ident(), TokenType::Ident) } @@ -649,10 +655,6 @@ impl<'a> Parser<'a> { } } - fn expect_no_suffix(&self, sp: Span, kind: &str, suffix: Option<ast::Name>) { - literal::expect_no_suffix(&self.sess.span_diagnostic, sp, kind, suffix) - } - /// 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. @@ -738,7 +740,7 @@ impl<'a> Parser<'a> { /// Parses a sequence, including the closing delimiter. The function /// `f` must consume tokens until reaching the next separator or /// closing bracket. - pub fn parse_seq_to_end<T>( + fn parse_seq_to_end<T>( &mut self, ket: &TokenKind, sep: SeqSep, @@ -754,7 +756,7 @@ impl<'a> Parser<'a> { /// Parses a sequence, not including the closing delimiter. The function /// `f` must consume tokens until reaching the next separator or /// closing bracket. - pub fn parse_seq_to_before_end<T>( + fn parse_seq_to_before_end<T>( &mut self, ket: &TokenKind, sep: SeqSep, @@ -772,7 +774,7 @@ impl<'a> Parser<'a> { }) } - crate fn parse_seq_to_before_tokens<T>( + fn parse_seq_to_before_tokens<T>( &mut self, kets: &[&TokenKind], sep: SeqSep, @@ -1018,7 +1020,7 @@ impl<'a> Parser<'a> { } } - crate fn process_potential_macro_variable(&mut self) { + 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()) => { @@ -1052,7 +1054,7 @@ impl<'a> Parser<'a> { } /// Parses a single token tree from the input. - crate fn parse_token_tree(&mut self) -> TokenTree { + pub fn parse_token_tree(&mut self) -> TokenTree { match self.token.kind { token::OpenDelim(..) => { let frame = mem::replace(&mut self.token_cursor.frame, @@ -1105,271 +1107,6 @@ impl<'a> Parser<'a> { res } - /// Parses the parameter list of a function, including the `(` and `)` delimiters. - fn parse_fn_params(&mut self, mut cfg: ParamCfg) -> PResult<'a, Vec<Param>> { - let sp = self.token.span; - let is_trait_item = cfg.is_self_allowed; - let mut c_variadic = false; - // Parse the arguments, starting out with `self` being possibly allowed... - let (params, _) = self.parse_paren_comma_seq(|p| { - let param = p.parse_param_general(&cfg, is_trait_item); - // ...now that we've parsed the first argument, `self` is no longer allowed. - cfg.is_self_allowed = false; - - match param { - Ok(param) => Ok( - if let TyKind::CVarArgs = param.ty.kind { - c_variadic = true; - if p.token != token::CloseDelim(token::Paren) { - p.span_err( - p.token.span, - "`...` must be the last argument of a C-variadic function", - ); - // FIXME(eddyb) this should probably still push `CVarArgs`. - // Maybe AST validation/HIR lowering should emit the above error? - None - } else { - Some(param) - } - } else { - Some(param) - } - ), - Err(mut e) => { - e.emit(); - let lo = p.prev_span; - // Skip every token until next possible arg or end. - p.eat_to_tokens(&[&token::Comma, &token::CloseDelim(token::Paren)]); - // Create a placeholder argument for proper arg count (issue #34264). - let span = lo.to(p.prev_span); - Ok(Some(dummy_arg(Ident::new(kw::Invalid, span)))) - } - } - })?; - - let mut params: Vec<_> = params.into_iter().filter_map(|x| x).collect(); - - // Replace duplicated recovered params with `_` pattern to avoid unecessary errors. - self.deduplicate_recovered_params_names(&mut params); - - if c_variadic && params.len() <= 1 { - self.span_err( - sp, - "C-variadic function must be declared with at least one named argument", - ); - } - - Ok(params) - } - - /// Skips unexpected attributes and doc comments in this position and emits an appropriate - /// error. - /// This version of parse param doesn't necessarily require identifier names. - fn parse_param_general(&mut self, cfg: &ParamCfg, is_trait_item: bool) -> PResult<'a, Param> { - let lo = self.token.span; - let attrs = self.parse_outer_attributes()?; - - // Possibly parse `self`. Recover if we parsed it and it wasn't allowed here. - if let Some(mut param) = self.parse_self_param()? { - param.attrs = attrs.into(); - return if cfg.is_self_allowed { - Ok(param) - } else { - self.recover_bad_self_param(param, is_trait_item) - }; - } - - let is_name_required = match self.token.kind { - token::DotDotDot => false, - _ => (cfg.is_name_required)(&self.token), - }; - let (pat, ty) = if is_name_required || self.is_named_param() { - debug!("parse_param_general parse_pat (is_name_required:{})", is_name_required); - - let pat = self.parse_fn_param_pat()?; - if let Err(mut err) = self.expect(&token::Colon) { - return if let Some(ident) = self.parameter_without_type( - &mut err, - pat, - is_name_required, - cfg.is_self_allowed, - is_trait_item, - ) { - err.emit(); - Ok(dummy_arg(ident)) - } else { - Err(err) - }; - } - - self.eat_incorrect_doc_comment_for_param_type(); - (pat, self.parse_ty_common(true, true, cfg.allow_c_variadic)?) - } else { - debug!("parse_param_general ident_to_pat"); - let parser_snapshot_before_ty = self.clone(); - self.eat_incorrect_doc_comment_for_param_type(); - let mut ty = self.parse_ty_common(true, true, cfg.allow_c_variadic); - if ty.is_ok() && self.token != token::Comma && - self.token != token::CloseDelim(token::Paren) { - // This wasn't actually a type, but a pattern looking like a type, - // so we are going to rollback and re-parse for recovery. - ty = self.unexpected(); - } - match ty { - Ok(ty) => { - let ident = Ident::new(kw::Invalid, self.prev_span); - let bm = BindingMode::ByValue(Mutability::Immutable); - let pat = self.mk_pat_ident(ty.span, bm, ident); - (pat, ty) - } - // If this is a C-variadic argument and we hit an error, return the error. - Err(err) if self.token == token::DotDotDot => return Err(err), - // Recover from attempting to parse the argument as a type without pattern. - Err(mut err) => { - err.cancel(); - mem::replace(self, parser_snapshot_before_ty); - self.recover_arg_parse()? - } - } - }; - - let span = lo.to(self.token.span); - - Ok(Param { - attrs: attrs.into(), - id: ast::DUMMY_NODE_ID, - is_placeholder: false, - pat, - span, - ty, - }) - } - - /// Returns the parsed optional self parameter and whether a self shortcut was used. - /// - /// See `parse_self_param_with_attrs` to collect attributes. - fn parse_self_param(&mut self) -> PResult<'a, Option<Param>> { - // Extract an identifier *after* having confirmed that the token is one. - let expect_self_ident = |this: &mut Self| { - match this.token.kind { - // Preserve hygienic context. - token::Ident(name, _) => { - let span = this.token.span; - this.bump(); - Ident::new(name, span) - } - _ => unreachable!(), - } - }; - // Is `self` `n` tokens ahead? - let is_isolated_self = |this: &Self, n| { - this.is_keyword_ahead(n, &[kw::SelfLower]) - && this.look_ahead(n + 1, |t| t != &token::ModSep) - }; - // Is `mut self` `n` tokens ahead? - let is_isolated_mut_self = |this: &Self, n| { - this.is_keyword_ahead(n, &[kw::Mut]) - && is_isolated_self(this, n + 1) - }; - // Parse `self` or `self: TYPE`. We already know the current token is `self`. - let parse_self_possibly_typed = |this: &mut Self, m| { - let eself_ident = expect_self_ident(this); - let eself_hi = this.prev_span; - let eself = if this.eat(&token::Colon) { - SelfKind::Explicit(this.parse_ty()?, m) - } else { - SelfKind::Value(m) - }; - Ok((eself, eself_ident, eself_hi)) - }; - // Recover for the grammar `*self`, `*const self`, and `*mut self`. - let recover_self_ptr = |this: &mut Self| { - let msg = "cannot pass `self` by raw pointer"; - let span = this.token.span; - this.struct_span_err(span, msg) - .span_label(span, msg) - .emit(); - - Ok((SelfKind::Value(Mutability::Immutable), expect_self_ident(this), this.prev_span)) - }; - - // Parse optional `self` parameter of a method. - // Only a limited set of initial token sequences is considered `self` parameters; anything - // else is parsed as a normal function parameter list, so some lookahead is required. - let eself_lo = self.token.span; - let (eself, eself_ident, eself_hi) = match self.token.kind { - token::BinOp(token::And) => { - let eself = if is_isolated_self(self, 1) { - // `&self` - self.bump(); - SelfKind::Region(None, Mutability::Immutable) - } else if is_isolated_mut_self(self, 1) { - // `&mut self` - self.bump(); - self.bump(); - SelfKind::Region(None, Mutability::Mutable) - } else if self.look_ahead(1, |t| t.is_lifetime()) && is_isolated_self(self, 2) { - // `&'lt self` - self.bump(); - let lt = self.expect_lifetime(); - SelfKind::Region(Some(lt), Mutability::Immutable) - } else if self.look_ahead(1, |t| t.is_lifetime()) && is_isolated_mut_self(self, 2) { - // `&'lt mut self` - self.bump(); - let lt = self.expect_lifetime(); - self.bump(); - SelfKind::Region(Some(lt), Mutability::Mutable) - } else { - // `¬_self` - return Ok(None); - }; - (eself, expect_self_ident(self), self.prev_span) - } - // `*self` - token::BinOp(token::Star) if is_isolated_self(self, 1) => { - self.bump(); - recover_self_ptr(self)? - } - // `*mut self` and `*const self` - token::BinOp(token::Star) if - self.look_ahead(1, |t| t.is_mutability()) - && is_isolated_self(self, 2) => - { - self.bump(); - self.bump(); - recover_self_ptr(self)? - } - // `self` and `self: TYPE` - token::Ident(..) if is_isolated_self(self, 0) => { - parse_self_possibly_typed(self, Mutability::Immutable)? - } - // `mut self` and `mut self: TYPE` - token::Ident(..) if is_isolated_mut_self(self, 0) => { - self.bump(); - parse_self_possibly_typed(self, Mutability::Mutable)? - } - _ => return Ok(None), - }; - - let eself = source_map::respan(eself_lo.to(eself_hi), eself); - Ok(Some(Param::from_self(ThinVec::default(), eself, eself_ident))) - } - - fn is_named_param(&self) -> bool { - let offset = match self.token.kind { - token::Interpolated(ref nt) => match **nt { - token::NtPat(..) => return self.look_ahead(1, |t| t == &token::Colon), - _ => 0, - } - token::BinOp(token::And) | token::AndAnd => 1, - _ if self.token.is_keyword(kw::Mut) => 1, - _ => 0, - }; - - self.look_ahead(offset, |t| t.is_ident()) && - self.look_ahead(offset + 1, |t| t == &token::Colon) - } - fn is_crate_vis(&self) -> bool { self.token.is_keyword(kw::Crate) && self.look_ahead(1, |t| t != &token::ModSep) } @@ -1454,12 +1191,14 @@ impl<'a> Parser<'a> { `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), - format!("in {}", path), + &format!("make this visible only to module `{}` with `in`", path_str), + format!("in {}", path_str), Applicability::MachineApplicable, ) .emit(); @@ -1548,7 +1287,7 @@ impl<'a> Parser<'a> { // 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::new(vec![]))); + return Ok((ret?, TokenStream::default())); } else { &mut self.token_cursor.stack[prev].last_token }; @@ -1563,7 +1302,7 @@ impl<'a> Parser<'a> { // 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::new(vec![]))); + return Ok((ret?, TokenStream::default())); } }; @@ -1601,7 +1340,7 @@ impl<'a> Parser<'a> { *t == token::BinOp(token::Star)) } - pub fn parse_optional_str(&mut self) -> Option<(Symbol, ast::StrStyle, Option<ast::Name>)> { + fn parse_optional_str(&mut self) -> Option<(Symbol, ast::StrStyle, Option<ast::Name>)> { let ret = match self.token.kind { token::Literal(token::Lit { kind: token::Str, symbol, suffix }) => (symbol, ast::StrStyle::Cooked, suffix), @@ -1641,7 +1380,7 @@ impl<'a> Parser<'a> { ], Applicability::MaybeIncorrect, ).span_suggestion( - self.sess.source_map.next_point(self.prev_span), + self.sess.source_map().next_point(self.prev_span), "add a semicolon", ';'.to_string(), Applicability::MaybeIncorrect, |