diff options
Diffstat (limited to 'src/libsyntax/parse/parser.rs')
| -rw-r--r-- | src/libsyntax/parse/parser.rs | 152 |
1 files changed, 81 insertions, 71 deletions
diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs index d99095eeba3..c3182602a4b 100644 --- a/src/libsyntax/parse/parser.rs +++ b/src/libsyntax/parse/parser.rs @@ -290,6 +290,7 @@ pub struct Parser<'a> { #[derive(PartialEq, Eq, Clone)] pub enum TokenType { Token(token::Token), + Keyword(keywords::Keyword), Operator, } @@ -298,6 +299,7 @@ impl TokenType { match *self { TokenType::Token(ref t) => format!("`{}`", Parser::token_to_string(t)), TokenType::Operator => "an operator".to_string(), + TokenType::Keyword(kw) => format!("`{}`", token::get_name(kw.to_name())), } } } @@ -365,9 +367,9 @@ impl<'a> Parser<'a> { token_str)[]); } - pub fn unexpected(&self) -> ! { - let this_token = self.this_token_to_string(); - self.fatal(&format!("unexpected token: `{}`", this_token)[]); + pub fn unexpected(&mut self) -> ! { + self.expect_one_of(&[], &[]); + unreachable!() } /// Expect and consume the token t. Signal an error if @@ -425,10 +427,13 @@ impl<'a> Parser<'a> { let expect = tokens_to_string(&expected[]); let actual = self.this_token_to_string(); self.fatal( - &(if expected.len() != 1 { + &(if expected.len() > 1 { (format!("expected one of {}, found `{}`", expect, actual)) + } else if expected.len() == 0 { + (format!("unexpected token: `{}`", + actual)) } else { (format!("expected {}, found `{}`", expect, @@ -515,7 +520,7 @@ impl<'a> Parser<'a> { pub fn parse_path_list_item(&mut self) -> ast::PathListItem { let lo = self.span.lo; - let node = if self.eat_keyword(keywords::Mod) { + let node = if self.eat_keyword_noexpect(keywords::Mod) { let span = self.last_span; self.span_warn(span, "deprecated syntax; use the `self` keyword now"); ast::PathListMod { id: ast::DUMMY_NODE_ID } @@ -547,9 +552,23 @@ impl<'a> Parser<'a> { is_present } + pub fn check_keyword(&mut self, kw: keywords::Keyword) -> bool { + self.expected_tokens.push(TokenType::Keyword(kw)); + self.token.is_keyword(kw) + } + /// If the next token is the given keyword, eat it and return /// true. Otherwise, return false. pub fn eat_keyword(&mut self, kw: keywords::Keyword) -> bool { + if self.check_keyword(kw) { + self.bump(); + true + } else { + false + } + } + + pub fn eat_keyword_noexpect(&mut self, kw: keywords::Keyword) -> bool { if self.token.is_keyword(kw) { self.bump(); true @@ -563,10 +582,7 @@ impl<'a> Parser<'a> { /// Otherwise, eat it. pub fn expect_keyword(&mut self, kw: keywords::Keyword) { if !self.eat_keyword(kw) { - let id_interned_str = token::get_name(kw.to_name()); - let token_str = self.this_token_to_string(); - self.fatal(&format!("expected `{}`, found `{}`", - id_interned_str, token_str)[]) + self.expect_one_of(&[], &[]); } } @@ -593,6 +609,7 @@ impl<'a> Parser<'a> { /// Expect and consume an `&`. If `&&` is seen, replace it with a single /// `&` and continue. If an `&` is not seen, signal an error. fn expect_and(&mut self) { + self.expected_tokens.push(TokenType::Token(token::BinOp(token::And))); match self.token { token::BinOp(token::And) => self.bump(), token::AndAnd => { @@ -601,12 +618,7 @@ impl<'a> Parser<'a> { self.replace_token(token::BinOp(token::And), lo, span.hi) } _ => { - let token_str = self.this_token_to_string(); - let found_token = - Parser::token_to_string(&token::BinOp(token::And)); - self.fatal(&format!("expected `{}`, found `{}`", - found_token, - token_str)[]) + self.expect_one_of(&[], &[]); } } } @@ -614,6 +626,7 @@ impl<'a> Parser<'a> { /// Expect and consume a `|`. If `||` is seen, replace it with a single /// `|` and continue. If a `|` is not seen, signal an error. fn expect_or(&mut self) { + self.expected_tokens.push(TokenType::Token(token::BinOp(token::Or))); match self.token { token::BinOp(token::Or) => self.bump(), token::OrOr => { @@ -622,12 +635,7 @@ impl<'a> Parser<'a> { self.replace_token(token::BinOp(token::Or), lo, span.hi) } _ => { - let found_token = self.this_token_to_string(); - let token_str = - Parser::token_to_string(&token::BinOp(token::Or)); - self.fatal(&format!("expected `{}`, found `{}`", - token_str, - found_token)[]) + self.expect_one_of(&[], &[]); } } } @@ -652,6 +660,7 @@ impl<'a> Parser<'a> { /// 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)); match self.token { token::Lt => { self.bump(); true } token::BinOp(token::Shl) => { @@ -666,11 +675,7 @@ impl<'a> Parser<'a> { fn expect_lt(&mut self) { if !self.eat_lt() { - let found_token = self.this_token_to_string(); - let token_str = Parser::token_to_string(&token::Lt); - self.fatal(&format!("expected `{}`, found `{}`", - token_str, - found_token)[]) + self.expect_one_of(&[], &[]); } } @@ -700,6 +705,7 @@ impl<'a> Parser<'a> { /// with a single > and continue. If a GT is not seen, /// signal an error. pub fn expect_gt(&mut self) { + self.expected_tokens.push(TokenType::Token(token::Gt)); match self.token { token::Gt => self.bump(), token::BinOp(token::Shr) => { @@ -740,7 +746,7 @@ impl<'a> Parser<'a> { // would encounter a `>` and stop. This lets the parser handle trailing // commas in generic parameters, because it can stop either after // parsing a type or after parsing a comma. - for i in iter::count(0us, 1) { + for i in iter::count(0, 1) { if self.check(&token::Gt) || self.token == token::BinOp(token::Shr) || self.token == token::Ge @@ -917,7 +923,7 @@ impl<'a> Parser<'a> { }; self.span = next.sp; self.token = next.tok; - self.tokens_consumed += 1us; + self.tokens_consumed += 1; self.expected_tokens.clear(); // check after each token self.check_unknown_macro_variable(); @@ -998,14 +1004,14 @@ impl<'a> Parser<'a> { /// Is the current token one of the keywords that signals a bare function /// type? pub fn token_is_bare_fn_keyword(&mut self) -> bool { - self.token.is_keyword(keywords::Fn) || - self.token.is_keyword(keywords::Unsafe) || - self.token.is_keyword(keywords::Extern) + self.check_keyword(keywords::Fn) || + self.check_keyword(keywords::Unsafe) || + self.check_keyword(keywords::Extern) } /// Is the current token one of the keywords that signals a closure type? pub fn token_is_closure_keyword(&mut self) -> bool { - self.token.is_keyword(keywords::Unsafe) + self.check_keyword(keywords::Unsafe) } pub fn get_lifetime(&mut self) -> ast::Ident { @@ -1035,7 +1041,7 @@ impl<'a> Parser<'a> { let lifetime_defs = self.parse_late_bound_lifetime_defs(); // examine next token to decide to do - if self.eat_keyword(keywords::Proc) { + if self.eat_keyword_noexpect(keywords::Proc) { self.parse_proc_type(lifetime_defs) } else if self.token_is_bare_fn_keyword() || self.token_is_closure_keyword() { self.parse_ty_bare_fn_or_ty_closure(lifetime_defs) @@ -1166,11 +1172,11 @@ impl<'a> Parser<'a> { // Closure: [unsafe] <'lt> |S| [:Bounds] -> T // Fn: [unsafe] [extern "ABI"] fn <'lt> (S) -> T - if self.token.is_keyword(keywords::Fn) { + if self.check_keyword(keywords::Fn) { self.parse_ty_bare_fn(lifetime_defs) - } else if self.token.is_keyword(keywords::Extern) { + } else if self.check_keyword(keywords::Extern) { self.parse_ty_bare_fn(lifetime_defs) - } else if self.token.is_keyword(keywords::Unsafe) { + } else if self.check_keyword(keywords::Unsafe) { if self.look_ahead(1, |t| t.is_keyword(keywords::Fn) || t.is_keyword(keywords::Extern)) { self.parse_ty_bare_fn(lifetime_defs) @@ -1480,7 +1486,7 @@ impl<'a> Parser<'a> { // BORROWED POINTER self.expect_and(); self.parse_borrowed_pointee() - } else if self.token.is_keyword(keywords::For) { + } else if self.check_keyword(keywords::For) { self.parse_for_in_type() } else if self.token_is_bare_fn_keyword() || self.token_is_closure_keyword() { @@ -1494,14 +1500,14 @@ impl<'a> Parser<'a> { })) { // CLOSURE self.parse_ty_closure(Vec::new()) - } else if self.eat_keyword(keywords::Typeof) { + } else if self.eat_keyword_noexpect(keywords::Typeof) { // TYPEOF // In order to not be ambiguous, the type must be surrounded by parens. self.expect(&token::OpenDelim(token::Paren)); let e = self.parse_expr(); self.expect(&token::CloseDelim(token::Paren)); TyTypeof(e) - } else if self.eat_keyword(keywords::Proc) { + } else if self.eat_keyword_noexpect(keywords::Proc) { self.parse_proc_type(Vec::new()) } else if self.eat_lt() { // QUALIFIED PATH `<TYPE as TRAIT_REF>::item` @@ -2092,6 +2098,7 @@ impl<'a> Parser<'a> { } fn expect_open_delim(&mut self) -> token::DelimToken { + self.expected_tokens.push(TokenType::Token(token::Gt)); match self.token { token::OpenDelim(delim) => { self.bump(); @@ -2233,7 +2240,7 @@ impl<'a> Parser<'a> { if self.eat_keyword(keywords::Move) { return self.parse_lambda_expr(CaptureByValue); } - if self.eat_keyword(keywords::Proc) { + if self.eat_keyword_noexpect(keywords::Proc) { let span = self.last_span; let _ = self.parse_proc_decl(); let _ = self.parse_expr(); @@ -2307,8 +2314,8 @@ impl<'a> Parser<'a> { hi = self.span.hi; } else if self.check(&token::ModSep) || self.token.is_ident() && - !self.token.is_keyword(keywords::True) && - !self.token.is_keyword(keywords::False) { + !self.check_keyword(keywords::True) && + !self.check_keyword(keywords::False) { let pth = self.parse_path(LifetimeAndTypesWithColons); @@ -2625,7 +2632,7 @@ impl<'a> Parser<'a> { } pub fn check_unknown_macro_variable(&mut self) { - if self.quote_depth == 0us { + if self.quote_depth == 0 { match self.token { token::SubstNt(name, _) => self.fatal(&format!("unknown macro variable `{}`", @@ -2694,7 +2701,7 @@ impl<'a> Parser<'a> { token_str)[]) }, /* we ought to allow different depths of unquotation */ - token::Dollar | token::SubstNt(..) if p.quote_depth > 0us => { + token::Dollar | token::SubstNt(..) if p.quote_depth > 0 => { p.parse_unquoted() } _ => { @@ -2706,7 +2713,7 @@ impl<'a> Parser<'a> { match self.token { token::Eof => { let open_braces = self.open_braces.clone(); - for sp in open_braces.iter() { + for sp in &open_braces { self.span_help(*sp, "did you mean to close this delimiter?"); } // There shouldn't really be a span, but it's easier for the test runner @@ -2735,7 +2742,7 @@ impl<'a> Parser<'a> { self.open_braces.pop().unwrap(); // Expand to cover the entire delimited token tree - let span = Span { hi: self.span.hi, ..pre_span }; + let span = Span { hi: close_span.hi, ..pre_span }; TtDelimited(span, Rc::new(Delimited { delim: delim, @@ -2792,7 +2799,7 @@ impl<'a> Parser<'a> { ex = ExprAddrOf(m, e); } token::Ident(_, _) => { - if !self.token.is_keyword(keywords::Box) { + if !self.check_keyword(keywords::Box) { return self.parse_dot_or_call_expr(); } @@ -2879,7 +2886,7 @@ impl<'a> Parser<'a> { } } None => { - if AS_PREC >= min_prec && self.eat_keyword(keywords::As) { + if AS_PREC >= min_prec && self.eat_keyword_noexpect(keywords::As) { let rhs = self.parse_ty(); let _as = self.mk_expr(lhs.span.lo, rhs.span.hi, @@ -3002,7 +3009,7 @@ impl<'a> Parser<'a> { /// Parse an 'if' or 'if let' expression ('if' token already eaten) pub fn parse_if_expr(&mut self) -> P<Expr> { - if self.token.is_keyword(keywords::Let) { + if self.check_keyword(keywords::Let) { return self.parse_if_let_expr(); } let lo = self.last_span.lo; @@ -3655,7 +3662,7 @@ impl<'a> Parser<'a> { } let lo = self.span.lo; - if self.token.is_keyword(keywords::Let) { + if self.check_keyword(keywords::Let) { check_expected_item(self, &item_attrs[]); self.expect_keyword(keywords::Let); let decl = self.parse_let(); @@ -5200,7 +5207,7 @@ impl<'a> Parser<'a> { Some(i) => { let mut err = String::from_str("circular modules: "); let len = included_mod_stack.len(); - for p in included_mod_stack[i.. len].iter() { + for p in &included_mod_stack[i.. len] { err.push_str(&p.display().as_cow()[]); err.push_str(" -> "); } @@ -5302,7 +5309,7 @@ impl<'a> Parser<'a> { let (maybe_path, ident) = match self.token { token::Ident(..) => { let the_ident = self.parse_ident(); - let path = if self.eat_keyword(keywords::As) { + let path = if self.eat_keyword_noexpect(keywords::As) { // skip the ident if there is one if self.token.is_ident() { self.bump(); } @@ -5445,7 +5452,7 @@ impl<'a> Parser<'a> { seq_sep_trailing_allowed(token::Comma), |p| p.parse_ty_sum() ); - for ty in arg_tys.into_iter() { + for ty in arg_tys { args.push(ast::VariantArg { ty: ty, id: ast::DUMMY_NODE_ID, @@ -5595,14 +5602,13 @@ impl<'a> Parser<'a> { token_str)[]); } - if self.eat_keyword(keywords::Virtual) { + if self.eat_keyword_noexpect(keywords::Virtual) { let span = self.span; self.span_err(span, "`virtual` structs have been removed from the language"); } - if self.token.is_keyword(keywords::Static) { + if self.eat_keyword(keywords::Static) { // STATIC ITEM - self.bump(); let m = if self.eat_keyword(keywords::Mut) {MutMutable} else {MutImmutable}; let (ident, item_, extra_attrs) = self.parse_item_const(Some(m)); let last_span = self.last_span; @@ -5614,9 +5620,8 @@ impl<'a> Parser<'a> { maybe_append(attrs, extra_attrs)); return Ok(item); } - if self.token.is_keyword(keywords::Const) { + if self.eat_keyword(keywords::Const) { // CONST ITEM - self.bump(); if self.eat_keyword(keywords::Mut) { let last_span = self.last_span; self.span_err(last_span, "const globals cannot be mutable"); @@ -5632,8 +5637,8 @@ impl<'a> Parser<'a> { maybe_append(attrs, extra_attrs)); return Ok(item); } - if self.token.is_keyword(keywords::Unsafe) && - self.look_ahead(1us, |t| t.is_keyword(keywords::Trait)) + if self.check_keyword(keywords::Unsafe) && + self.look_ahead(1, |t| t.is_keyword(keywords::Trait)) { // UNSAFE TRAIT ITEM self.expect_keyword(keywords::Unsafe); @@ -5649,8 +5654,8 @@ impl<'a> Parser<'a> { maybe_append(attrs, extra_attrs)); return Ok(item); } - if self.token.is_keyword(keywords::Unsafe) && - self.look_ahead(1us, |t| t.is_keyword(keywords::Impl)) + if self.check_keyword(keywords::Unsafe) && + self.look_ahead(1, |t| t.is_keyword(keywords::Impl)) { // IMPL ITEM self.expect_keyword(keywords::Unsafe); @@ -5665,7 +5670,7 @@ impl<'a> Parser<'a> { maybe_append(attrs, extra_attrs)); return Ok(item); } - if self.token.is_keyword(keywords::Fn) { + if self.check_keyword(keywords::Fn) { // FUNCTION ITEM self.bump(); let (ident, item_, extra_attrs) = @@ -5679,8 +5684,8 @@ impl<'a> Parser<'a> { maybe_append(attrs, extra_attrs)); return Ok(item); } - if self.token.is_keyword(keywords::Unsafe) - && self.look_ahead(1us, |t| *t != token::OpenDelim(token::Brace)) { + if self.check_keyword(keywords::Unsafe) + && self.look_ahead(1, |t| *t != token::OpenDelim(token::Brace)) { // UNSAFE FUNCTION ITEM self.bump(); let abi = if self.eat_keyword(keywords::Extern) { @@ -5784,11 +5789,11 @@ impl<'a> Parser<'a> { let visibility = self.parse_visibility(); - if self.token.is_keyword(keywords::Static) { + if self.check_keyword(keywords::Static) { // FOREIGN STATIC ITEM return Ok(self.parse_item_foreign_static(visibility, attrs)); } - if self.token.is_keyword(keywords::Fn) || self.token.is_keyword(keywords::Unsafe) { + if self.check_keyword(keywords::Fn) || self.check_keyword(keywords::Unsafe) { // FOREIGN FUNCTION ITEM return Ok(self.parse_item_foreign_fn(visibility, attrs)); } @@ -5912,9 +5917,9 @@ impl<'a> Parser<'a> { self.bump(); match self.token { - token::Ident(i, _) => { - self.bump(); - path.push(i); + token::Ident(..) => { + let ident = self.parse_ident(); + path.push(ident); } // foo::bar::{a,b,c} @@ -5954,11 +5959,16 @@ impl<'a> Parser<'a> { return P(spanned(lo, self.span.hi, ViewPathGlob(path))); } + // fall-through for case foo::bar::; + token::Semi => { + self.span_err(self.span, "expected identifier or `{` or `*`, found `;`"); + } + _ => break } } } - let mut rename_to = path[path.len() - 1us]; + let mut rename_to = path[path.len() - 1]; let path = ast::Path { span: mk_sp(lo, self.last_span.hi), global: false, |