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// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
use attr;
use ast;
use codemap::{spanned, Spanned, mk_sp, Span};
use parse::common::SeqSep;
use parse::PResult;
use parse::token;
use parse::parser::{Parser, TokenType};
use ptr::P;
impl<'a> Parser<'a> {
/// Parse attributes that appear before an item
pub fn parse_outer_attributes(&mut self) -> PResult<'a, Vec<ast::Attribute>> {
let mut attrs: Vec<ast::Attribute> = Vec::new();
loop {
debug!("parse_outer_attributes: self.token={:?}", self.token);
match self.token {
token::Pound => {
attrs.push(self.parse_attribute(false)?);
}
token::DocComment(s) => {
let attr = ::attr::mk_sugared_doc_attr(
attr::mk_attr_id(),
self.id_to_interned_str(ast::Ident::with_empty_ctxt(s)),
self.span.lo,
self.span.hi
);
if attr.node.style != ast::AttrStyle::Outer {
return Err(self.fatal("expected outer comment"));
}
attrs.push(attr);
self.bump();
}
_ => break,
}
}
return Ok(attrs);
}
/// Matches `attribute = # ! [ meta_item ]`
///
/// If permit_inner is true, then a leading `!` indicates an inner
/// attribute
pub fn parse_attribute(&mut self, permit_inner: bool) -> PResult<'a, ast::Attribute> {
debug!("parse_attributes: permit_inner={:?} self.token={:?}",
permit_inner,
self.token);
let (span, value, mut style) = match self.token {
token::Pound => {
let lo = self.span.lo;
self.bump();
if permit_inner {
self.expected_tokens.push(TokenType::Token(token::Not));
}
let style = if self.token == token::Not {
self.bump();
if !permit_inner {
let span = self.span;
self.diagnostic()
.struct_span_err(span,
"an inner attribute is not permitted in this context")
.fileline_help(span,
"place inner attribute at the top of the module or \
block")
.emit()
}
ast::AttrStyle::Inner
} else {
ast::AttrStyle::Outer
};
self.expect(&token::OpenDelim(token::Bracket))?;
let meta_item = self.parse_meta_item()?;
let hi = self.span.hi;
self.expect(&token::CloseDelim(token::Bracket))?;
(mk_sp(lo, hi), meta_item, style)
}
_ => {
let token_str = self.this_token_to_string();
return Err(self.fatal(&format!("expected `#`, found `{}`", token_str)));
}
};
if permit_inner && self.token == token::Semi {
self.bump();
self.span_warn(span,
"this inner attribute syntax is deprecated. The new syntax is \
`#![foo]`, with a bang and no semicolon");
style = ast::AttrStyle::Inner;
}
Ok(Spanned {
span: span,
node: ast::Attribute_ {
id: attr::mk_attr_id(),
style: style,
value: value,
is_sugared_doc: false,
},
})
}
/// Parse attributes that appear after the opening of an item. These should
/// be preceded by an exclamation mark, but we accept and warn about one
/// terminated by a semicolon.
/// matches inner_attrs*
pub fn parse_inner_attributes(&mut self) -> PResult<'a, Vec<ast::Attribute>> {
let mut attrs: Vec<ast::Attribute> = vec![];
loop {
match self.token {
token::Pound => {
// Don't even try to parse if it's not an inner attribute.
if !self.look_ahead(1, |t| t == &token::Not) {
break;
}
let attr = self.parse_attribute(true)?;
assert!(attr.node.style == ast::AttrStyle::Inner);
attrs.push(attr);
}
token::DocComment(s) => {
// we need to get the position of this token before we bump.
let Span { lo, hi, .. } = self.span;
let str = self.id_to_interned_str(ast::Ident::with_empty_ctxt(s));
let attr = attr::mk_sugared_doc_attr(attr::mk_attr_id(), str, lo, hi);
if attr.node.style == ast::AttrStyle::Inner {
attrs.push(attr);
self.bump();
} else {
break;
}
}
_ => break,
}
}
Ok(attrs)
}
/// matches meta_item = IDENT
/// | IDENT = lit
/// | IDENT meta_seq
pub fn parse_meta_item(&mut self) -> PResult<'a, P<ast::MetaItem>> {
let nt_meta = match self.token {
token::Interpolated(token::NtMeta(ref e)) => Some(e.clone()),
_ => None,
};
match nt_meta {
Some(meta) => {
self.bump();
return Ok(meta);
}
None => {}
}
let lo = self.span.lo;
let ident = self.parse_ident()?;
let name = self.id_to_interned_str(ident);
match self.token {
token::Eq => {
self.bump();
let lit = self.parse_lit()?;
// FIXME #623 Non-string meta items are not serialized correctly;
// just forbid them for now
match lit.node {
ast::LitKind::Str(..) => {}
_ => {
self.span_err(lit.span,
"non-string literals are not allowed in meta-items");
}
}
let hi = self.span.hi;
Ok(P(spanned(lo, hi, ast::MetaItemKind::NameValue(name, lit))))
}
token::OpenDelim(token::Paren) => {
let inner_items = self.parse_meta_seq()?;
let hi = self.span.hi;
Ok(P(spanned(lo, hi, ast::MetaItemKind::List(name, inner_items))))
}
_ => {
let hi = self.last_span.hi;
Ok(P(spanned(lo, hi, ast::MetaItemKind::Word(name))))
}
}
}
/// matches meta_seq = ( COMMASEP(meta_item) )
fn parse_meta_seq(&mut self) -> PResult<'a, Vec<P<ast::MetaItem>>> {
self.parse_unspanned_seq(&token::OpenDelim(token::Paren),
&token::CloseDelim(token::Paren),
SeqSep::trailing_allowed(token::Comma),
|p: &mut Parser<'a>| p.parse_meta_item())
}
}