1 // Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 // Functions dealing with attributes and meta items
13 pub use self::StabilityLevel::*;
14 pub use self::ReprAttr::*;
15 pub use self::IntType::*;
18 use ast::{AttrId, Attribute, Name, Ident};
19 use ast::{MetaItem, MetaItemKind, NestedMetaItem, NestedMetaItemKind};
20 use ast::{Lit, LitKind, Expr, ExprKind, Item, Local, Stmt, StmtKind};
21 use codemap::{Spanned, respan, dummy_spanned};
22 use syntax_pos::{Span, DUMMY_SP};
24 use feature_gate::{Features, GatedCfg};
25 use parse::lexer::comments::{doc_comment_style, strip_doc_comment_decoration};
26 use parse::parser::Parser;
27 use parse::{self, ParseSess, PResult};
28 use parse::token::{self, Token};
31 use tokenstream::{TokenStream, TokenTree, Delimited};
34 use std::cell::RefCell;
38 static USED_ATTRS: RefCell<Vec<u64>> = RefCell::new(Vec::new());
39 static KNOWN_ATTRS: RefCell<Vec<u64>> = RefCell::new(Vec::new());
44 UnknownMetaItem(Name),
47 MultipleStabilityLevels,
51 fn handle_errors(diag: &Handler, span: Span, error: AttrError) {
53 AttrError::MultipleItem(item) => span_err!(diag, span, E0538,
54 "multiple '{}' items", item),
55 AttrError::UnknownMetaItem(item) => span_err!(diag, span, E0541,
56 "unknown meta item '{}'", item),
57 AttrError::MissingSince => span_err!(diag, span, E0542, "missing 'since'"),
58 AttrError::MissingFeature => span_err!(diag, span, E0546, "missing 'feature'"),
59 AttrError::MultipleStabilityLevels => span_err!(diag, span, E0544,
60 "multiple stability levels"),
61 AttrError::UnsupportedLiteral => span_err!(diag, span, E0565, "unsupported literal"),
65 pub fn mark_used(attr: &Attribute) {
66 debug!("Marking {:?} as used.", attr);
67 let AttrId(id) = attr.id;
68 USED_ATTRS.with(|slot| {
69 let idx = (id / 64) as usize;
71 if slot.borrow().len() <= idx {
72 slot.borrow_mut().resize(idx + 1, 0);
74 slot.borrow_mut()[idx] |= 1 << shift;
78 pub fn is_used(attr: &Attribute) -> bool {
79 let AttrId(id) = attr.id;
80 USED_ATTRS.with(|slot| {
81 let idx = (id / 64) as usize;
83 slot.borrow().get(idx).map(|bits| bits & (1 << shift) != 0)
88 pub fn mark_known(attr: &Attribute) {
89 debug!("Marking {:?} as known.", attr);
90 let AttrId(id) = attr.id;
91 KNOWN_ATTRS.with(|slot| {
92 let idx = (id / 64) as usize;
94 if slot.borrow().len() <= idx {
95 slot.borrow_mut().resize(idx + 1, 0);
97 slot.borrow_mut()[idx] |= 1 << shift;
101 pub fn is_known(attr: &Attribute) -> bool {
102 let AttrId(id) = attr.id;
103 KNOWN_ATTRS.with(|slot| {
104 let idx = (id / 64) as usize;
106 slot.borrow().get(idx).map(|bits| bits & (1 << shift) != 0)
111 impl NestedMetaItem {
112 /// Returns the MetaItem if self is a NestedMetaItemKind::MetaItem.
113 pub fn meta_item(&self) -> Option<&MetaItem> {
115 NestedMetaItemKind::MetaItem(ref item) => Some(item),
120 /// Returns the Lit if self is a NestedMetaItemKind::Literal.
121 pub fn literal(&self) -> Option<&Lit> {
123 NestedMetaItemKind::Literal(ref lit) => Some(lit),
128 /// Returns the Span for `self`.
129 pub fn span(&self) -> Span {
133 /// Returns true if this list item is a MetaItem with a name of `name`.
134 pub fn check_name(&self, name: &str) -> bool {
135 self.meta_item().map_or(false, |meta_item| meta_item.check_name(name))
138 /// Returns the name of the meta item, e.g. `foo` in `#[foo]`,
139 /// `#[foo="bar"]` and `#[foo(bar)]`, if self is a MetaItem
140 pub fn name(&self) -> Option<Name> {
141 self.meta_item().and_then(|meta_item| Some(meta_item.name()))
144 /// Gets the string value if self is a MetaItem and the MetaItem is a
145 /// MetaItemKind::NameValue variant containing a string, otherwise None.
146 pub fn value_str(&self) -> Option<Symbol> {
147 self.meta_item().and_then(|meta_item| meta_item.value_str())
150 /// Returns a name and single literal value tuple of the MetaItem.
151 pub fn name_value_literal(&self) -> Option<(Name, &Lit)> {
152 self.meta_item().and_then(
153 |meta_item| meta_item.meta_item_list().and_then(
155 if meta_item_list.len() == 1 {
156 let nested_item = &meta_item_list[0];
157 if nested_item.is_literal() {
158 Some((meta_item.name(), nested_item.literal().unwrap()))
168 /// Returns a MetaItem if self is a MetaItem with Kind Word.
169 pub fn word(&self) -> Option<&MetaItem> {
170 self.meta_item().and_then(|meta_item| if meta_item.is_word() {
177 /// Gets a list of inner meta items from a list MetaItem type.
178 pub fn meta_item_list(&self) -> Option<&[NestedMetaItem]> {
179 self.meta_item().and_then(|meta_item| meta_item.meta_item_list())
182 /// Returns `true` if the variant is MetaItem.
183 pub fn is_meta_item(&self) -> bool {
184 self.meta_item().is_some()
187 /// Returns `true` if the variant is Literal.
188 pub fn is_literal(&self) -> bool {
189 self.literal().is_some()
192 /// Returns `true` if self is a MetaItem and the meta item is a word.
193 pub fn is_word(&self) -> bool {
194 self.word().is_some()
197 /// Returns `true` if self is a MetaItem and the meta item is a ValueString.
198 pub fn is_value_str(&self) -> bool {
199 self.value_str().is_some()
202 /// Returns `true` if self is a MetaItem and the meta item is a list.
203 pub fn is_meta_item_list(&self) -> bool {
204 self.meta_item_list().is_some()
209 pub fn check_name(&self, name: &str) -> bool {
210 let matches = self.path == name;
217 pub fn name(&self) -> Option<Name> {
218 match self.path.segments.len() {
219 1 => Some(self.path.segments[0].identifier.name),
224 pub fn value_str(&self) -> Option<Symbol> {
225 self.meta().and_then(|meta| meta.value_str())
228 pub fn meta_item_list(&self) -> Option<Vec<NestedMetaItem>> {
230 Some(MetaItem { node: MetaItemKind::List(list), .. }) => Some(list),
235 pub fn is_word(&self) -> bool {
236 self.path.segments.len() == 1 && self.tokens.is_empty()
239 pub fn span(&self) -> Span {
243 pub fn is_meta_item_list(&self) -> bool {
244 self.meta_item_list().is_some()
247 /// Indicates if the attribute is a Value String.
248 pub fn is_value_str(&self) -> bool {
249 self.value_str().is_some()
254 pub fn name(&self) -> Name {
258 pub fn value_str(&self) -> Option<Symbol> {
260 MetaItemKind::NameValue(ref v) => {
262 LitKind::Str(ref s, _) => Some(*s),
270 pub fn meta_item_list(&self) -> Option<&[NestedMetaItem]> {
272 MetaItemKind::List(ref l) => Some(&l[..]),
277 pub fn is_word(&self) -> bool {
279 MetaItemKind::Word => true,
284 pub fn span(&self) -> Span { self.span }
286 pub fn check_name(&self, name: &str) -> bool {
290 pub fn is_value_str(&self) -> bool {
291 self.value_str().is_some()
294 pub fn is_meta_item_list(&self) -> bool {
295 self.meta_item_list().is_some()
300 /// Extract the MetaItem from inside this Attribute.
301 pub fn meta(&self) -> Option<MetaItem> {
302 let mut tokens = self.tokens.trees().peekable();
304 name: match self.path.segments.len() {
305 1 => self.path.segments[0].identifier.name,
308 node: if let Some(node) = MetaItemKind::from_tokens(&mut tokens) {
309 if tokens.peek().is_some() {
320 pub fn parse<'a, T, F>(&self, sess: &'a ParseSess, mut f: F) -> PResult<'a, T>
321 where F: FnMut(&mut Parser<'a>) -> PResult<'a, T>,
323 let mut parser = Parser::new(sess, self.tokens.clone(), None, false, false);
324 let result = f(&mut parser)?;
325 if parser.token != token::Eof {
326 parser.unexpected()?;
331 pub fn parse_list<'a, T, F>(&self, sess: &'a ParseSess, mut f: F) -> PResult<'a, Vec<T>>
332 where F: FnMut(&mut Parser<'a>) -> PResult<'a, T>,
334 if self.tokens.is_empty() {
335 return Ok(Vec::new());
337 self.parse(sess, |parser| {
338 parser.expect(&token::OpenDelim(token::Paren))?;
339 let mut list = Vec::new();
340 while !parser.eat(&token::CloseDelim(token::Paren)) {
341 list.push(f(parser)?);
342 if !parser.eat(&token::Comma) {
343 parser.expect(&token::CloseDelim(token::Paren))?;
351 pub fn parse_meta<'a>(&self, sess: &'a ParseSess) -> PResult<'a, MetaItem> {
352 if self.path.segments.len() > 1 {
353 sess.span_diagnostic.span_err(self.path.span, "expected ident, found path");
357 name: self.path.segments.last().unwrap().identifier.name,
358 node: self.parse(sess, |parser| parser.parse_meta_item_kind())?,
363 /// Convert self to a normal #[doc="foo"] comment, if it is a
364 /// comment like `///` or `/** */`. (Returns self unchanged for
365 /// non-sugared doc attributes.)
366 pub fn with_desugared_doc<T, F>(&self, f: F) -> T where
367 F: FnOnce(&Attribute) -> T,
369 if self.is_sugared_doc {
370 let comment = self.value_str().unwrap();
371 let meta = mk_name_value_item_str(
372 Symbol::intern("doc"),
373 Symbol::intern(&strip_doc_comment_decoration(&comment.as_str())));
374 let mut attr = if self.style == ast::AttrStyle::Outer {
375 mk_attr_outer(self.span, self.id, meta)
377 mk_attr_inner(self.span, self.id, meta)
379 attr.is_sugared_doc = true;
389 pub fn mk_name_value_item_str(name: Name, value: Symbol) -> MetaItem {
390 let value_lit = dummy_spanned(LitKind::Str(value, ast::StrStyle::Cooked));
391 mk_spanned_name_value_item(DUMMY_SP, name, value_lit)
394 pub fn mk_name_value_item(name: Name, value: ast::Lit) -> MetaItem {
395 mk_spanned_name_value_item(DUMMY_SP, name, value)
398 pub fn mk_list_item(name: Name, items: Vec<NestedMetaItem>) -> MetaItem {
399 mk_spanned_list_item(DUMMY_SP, name, items)
402 pub fn mk_list_word_item(name: Name) -> ast::NestedMetaItem {
403 dummy_spanned(NestedMetaItemKind::MetaItem(mk_spanned_word_item(DUMMY_SP, name)))
406 pub fn mk_word_item(name: Name) -> MetaItem {
407 mk_spanned_word_item(DUMMY_SP, name)
410 pub fn mk_spanned_name_value_item(sp: Span, name: Name, value: ast::Lit) -> MetaItem {
411 MetaItem { span: sp, name: name, node: MetaItemKind::NameValue(value) }
414 pub fn mk_spanned_list_item(sp: Span, name: Name, items: Vec<NestedMetaItem>) -> MetaItem {
415 MetaItem { span: sp, name: name, node: MetaItemKind::List(items) }
418 pub fn mk_spanned_word_item(sp: Span, name: Name) -> MetaItem {
419 MetaItem { span: sp, name: name, node: MetaItemKind::Word }
422 pub fn mk_attr_id() -> AttrId {
423 use std::sync::atomic::AtomicUsize;
424 use std::sync::atomic::Ordering;
426 static NEXT_ATTR_ID: AtomicUsize = AtomicUsize::new(0);
428 let id = NEXT_ATTR_ID.fetch_add(1, Ordering::SeqCst);
429 assert!(id != ::std::usize::MAX);
433 /// Returns an inner attribute with the given value.
434 pub fn mk_attr_inner(span: Span, id: AttrId, item: MetaItem) -> Attribute {
435 mk_spanned_attr_inner(span, id, item)
438 /// Returns an inner attribute with the given value and span.
439 pub fn mk_spanned_attr_inner(sp: Span, id: AttrId, item: MetaItem) -> Attribute {
442 style: ast::AttrStyle::Inner,
443 path: ast::Path::from_ident(item.span, ast::Ident::with_empty_ctxt(item.name)),
444 tokens: item.node.tokens(item.span),
445 is_sugared_doc: false,
451 /// Returns an outer attribute with the given value.
452 pub fn mk_attr_outer(span: Span, id: AttrId, item: MetaItem) -> Attribute {
453 mk_spanned_attr_outer(span, id, item)
456 /// Returns an outer attribute with the given value and span.
457 pub fn mk_spanned_attr_outer(sp: Span, id: AttrId, item: MetaItem) -> Attribute {
460 style: ast::AttrStyle::Outer,
461 path: ast::Path::from_ident(item.span, ast::Ident::with_empty_ctxt(item.name)),
462 tokens: item.node.tokens(item.span),
463 is_sugared_doc: false,
468 pub fn mk_sugared_doc_attr(id: AttrId, text: Symbol, span: Span) -> Attribute {
469 let style = doc_comment_style(&text.as_str());
470 let lit = respan(span, LitKind::Str(text, ast::StrStyle::Cooked));
474 path: ast::Path::from_ident(span, ast::Ident::from_str("doc")),
475 tokens: MetaItemKind::NameValue(lit).tokens(span),
476 is_sugared_doc: true,
481 pub fn list_contains_name(items: &[NestedMetaItem], name: &str) -> bool {
482 items.iter().any(|item| {
483 item.check_name(name)
487 pub fn contains_name(attrs: &[Attribute], name: &str) -> bool {
488 attrs.iter().any(|item| {
489 item.check_name(name)
493 pub fn find_by_name<'a>(attrs: &'a [Attribute], name: &str) -> Option<&'a Attribute> {
494 attrs.iter().find(|attr| attr.check_name(name))
497 pub fn first_attr_value_str_by_name(attrs: &[Attribute], name: &str) -> Option<Symbol> {
499 .find(|at| at.check_name(name))
500 .and_then(|at| at.value_str())
503 /// Check if `attrs` contains an attribute like `#![feature(feature_name)]`.
504 /// This will not perform any "sanity checks" on the form of the attributes.
505 pub fn contains_feature_attr(attrs: &[Attribute], feature_name: &str) -> bool {
506 attrs.iter().any(|item| {
507 item.check_name("feature") &&
508 item.meta_item_list().map(|list| {
509 list.iter().any(|mi| {
510 mi.word().map(|w| w.name() == feature_name)
517 /* Higher-level applications */
519 pub fn find_crate_name(attrs: &[Attribute]) -> Option<Symbol> {
520 first_attr_value_str_by_name(attrs, "crate_name")
523 #[derive(Copy, Clone, PartialEq)]
524 pub enum InlineAttr {
531 /// Determine what `#[inline]` attribute is present in `attrs`, if any.
532 pub fn find_inline_attr(diagnostic: Option<&Handler>, attrs: &[Attribute]) -> InlineAttr {
533 attrs.iter().fold(InlineAttr::None, |ia, attr| {
534 if attr.path != "inline" {
537 let meta = match attr.meta() {
538 Some(meta) => meta.node,
542 MetaItemKind::Word => {
546 MetaItemKind::List(ref items) => {
548 if items.len() != 1 {
549 diagnostic.map(|d|{ span_err!(d, attr.span, E0534, "expected one argument"); });
551 } else if list_contains_name(&items[..], "always") {
553 } else if list_contains_name(&items[..], "never") {
557 span_err!(d, items[0].span, E0535, "invalid argument");
568 /// True if `#[inline]` or `#[inline(always)]` is present in `attrs`.
569 pub fn requests_inline(attrs: &[Attribute]) -> bool {
570 match find_inline_attr(None, attrs) {
571 InlineAttr::Hint | InlineAttr::Always => true,
572 InlineAttr::None | InlineAttr::Never => false,
576 /// Tests if a cfg-pattern matches the cfg set
577 pub fn cfg_matches(cfg: &ast::MetaItem, sess: &ParseSess, features: Option<&Features>) -> bool {
578 eval_condition(cfg, sess, &mut |cfg| {
579 if let (Some(feats), Some(gated_cfg)) = (features, GatedCfg::gate(cfg)) {
580 gated_cfg.check_and_emit(sess, feats);
582 sess.config.contains(&(cfg.name(), cfg.value_str()))
586 /// Evaluate a cfg-like condition (with `any` and `all`), using `eval` to
587 /// evaluate individual items.
588 pub fn eval_condition<F>(cfg: &ast::MetaItem, sess: &ParseSess, eval: &mut F)
590 where F: FnMut(&ast::MetaItem) -> bool
593 ast::MetaItemKind::List(ref mis) => {
594 for mi in mis.iter() {
595 if !mi.is_meta_item() {
596 handle_errors(&sess.span_diagnostic, mi.span, AttrError::UnsupportedLiteral);
601 // The unwraps below may look dangerous, but we've already asserted
602 // that they won't fail with the loop above.
603 match &*cfg.name.as_str() {
604 "any" => mis.iter().any(|mi| {
605 eval_condition(mi.meta_item().unwrap(), sess, eval)
607 "all" => mis.iter().all(|mi| {
608 eval_condition(mi.meta_item().unwrap(), sess, eval)
612 span_err!(sess.span_diagnostic, cfg.span, E0536, "expected 1 cfg-pattern");
616 !eval_condition(mis[0].meta_item().unwrap(), sess, eval)
619 span_err!(sess.span_diagnostic, cfg.span, E0537, "invalid predicate `{}`", p);
624 ast::MetaItemKind::Word | ast::MetaItemKind::NameValue(..) => {
630 /// Represents the #[stable], #[unstable], #[rustc_{deprecated,const_unstable}] attributes.
631 #[derive(RustcEncodable, RustcDecodable, Clone, Debug, PartialEq, Eq, Hash)]
632 pub struct Stability {
633 pub level: StabilityLevel,
635 pub rustc_depr: Option<RustcDeprecation>,
636 pub rustc_const_unstable: Option<RustcConstUnstable>,
639 /// The available stability levels.
640 #[derive(RustcEncodable, RustcDecodable, PartialEq, PartialOrd, Clone, Debug, Eq, Hash)]
641 pub enum StabilityLevel {
642 // Reason for the current stability level and the relevant rust-lang issue
643 Unstable { reason: Option<Symbol>, issue: u32 },
644 Stable { since: Symbol },
647 #[derive(RustcEncodable, RustcDecodable, PartialEq, PartialOrd, Clone, Debug, Eq, Hash)]
648 pub struct RustcDeprecation {
653 #[derive(RustcEncodable, RustcDecodable, PartialEq, PartialOrd, Clone, Debug, Eq, Hash)]
654 pub struct RustcConstUnstable {
658 #[derive(RustcEncodable, RustcDecodable, PartialEq, PartialOrd, Clone, Debug, Eq, Hash)]
659 pub struct Deprecation {
660 pub since: Option<Symbol>,
661 pub note: Option<Symbol>,
664 impl StabilityLevel {
665 pub fn is_unstable(&self) -> bool { if let Unstable {..} = *self { true } else { false }}
666 pub fn is_stable(&self) -> bool { if let Stable {..} = *self { true } else { false }}
669 fn find_stability_generic<'a, I>(diagnostic: &Handler,
673 where I: Iterator<Item = &'a Attribute>
675 let mut stab: Option<Stability> = None;
676 let mut rustc_depr: Option<RustcDeprecation> = None;
677 let mut rustc_const_unstable: Option<RustcConstUnstable> = None;
679 'outer: for attr in attrs_iter {
682 "rustc_const_unstable",
685 ].iter().any(|&s| attr.path == s) {
686 continue // not a stability level
691 let meta = attr.meta();
692 if let Some(MetaItem { node: MetaItemKind::List(ref metas), .. }) = meta {
693 let meta = meta.as_ref().unwrap();
694 let get = |meta: &MetaItem, item: &mut Option<Symbol>| {
696 handle_errors(diagnostic, meta.span, AttrError::MultipleItem(meta.name()));
699 if let Some(v) = meta.value_str() {
703 span_err!(diagnostic, meta.span, E0539, "incorrect meta item");
708 macro_rules! get_meta {
709 ($($name:ident),+) => {
711 let mut $name = None;
714 if let Some(mi) = meta.meta_item() {
715 match &*mi.name().as_str() {
718 => if !get(mi, &mut $name) { continue 'outer },
721 handle_errors(diagnostic, mi.span,
722 AttrError::UnknownMetaItem(mi.name()));
727 handle_errors(diagnostic, meta.span, AttrError::UnsupportedLiteral);
734 match &*meta.name.as_str() {
735 "rustc_deprecated" => {
736 if rustc_depr.is_some() {
737 span_err!(diagnostic, item_sp, E0540,
738 "multiple rustc_deprecated attributes");
742 get_meta!(since, reason);
744 match (since, reason) {
745 (Some(since), Some(reason)) => {
746 rustc_depr = Some(RustcDeprecation {
752 handle_errors(diagnostic, attr.span(), AttrError::MissingSince);
756 span_err!(diagnostic, attr.span(), E0543, "missing 'reason'");
761 "rustc_const_unstable" => {
762 if rustc_const_unstable.is_some() {
763 span_err!(diagnostic, item_sp, E0553,
764 "multiple rustc_const_unstable attributes");
769 if let Some(feature) = feature {
770 rustc_const_unstable = Some(RustcConstUnstable {
774 span_err!(diagnostic, attr.span(), E0629, "missing 'feature'");
780 handle_errors(diagnostic, attr.span(), AttrError::MultipleStabilityLevels);
784 let mut feature = None;
785 let mut reason = None;
786 let mut issue = None;
788 if let Some(mi) = meta.meta_item() {
789 match &*mi.name().as_str() {
790 "feature" => if !get(mi, &mut feature) { continue 'outer },
791 "reason" => if !get(mi, &mut reason) { continue 'outer },
792 "issue" => if !get(mi, &mut issue) { continue 'outer },
794 handle_errors(diagnostic, meta.span,
795 AttrError::UnknownMetaItem(mi.name()));
800 handle_errors(diagnostic, meta.span, AttrError::UnsupportedLiteral);
805 match (feature, reason, issue) {
806 (Some(feature), reason, Some(issue)) => {
807 stab = Some(Stability {
811 if let Ok(issue) = issue.as_str().parse() {
814 span_err!(diagnostic, attr.span(), E0545,
815 "incorrect 'issue'");
822 rustc_const_unstable: None,
826 handle_errors(diagnostic, attr.span(), AttrError::MissingFeature);
830 span_err!(diagnostic, attr.span(), E0547, "missing 'issue'");
837 handle_errors(diagnostic, attr.span(), AttrError::MultipleStabilityLevels);
841 let mut feature = None;
842 let mut since = None;
844 if let NestedMetaItemKind::MetaItem(ref mi) = meta.node {
845 match &*mi.name().as_str() {
846 "feature" => if !get(mi, &mut feature) { continue 'outer },
847 "since" => if !get(mi, &mut since) { continue 'outer },
849 handle_errors(diagnostic, meta.span,
850 AttrError::UnknownMetaItem(mi.name()));
855 handle_errors(diagnostic, meta.span, AttrError::UnsupportedLiteral);
860 match (feature, since) {
861 (Some(feature), Some(since)) => {
862 stab = Some(Stability {
868 rustc_const_unstable: None,
872 handle_errors(diagnostic, attr.span(), AttrError::MissingFeature);
876 handle_errors(diagnostic, attr.span(), AttrError::MissingSince);
884 span_err!(diagnostic, attr.span(), E0548, "incorrect stability attribute type");
889 // Merge the deprecation info into the stability info
890 if let Some(rustc_depr) = rustc_depr {
891 if let Some(ref mut stab) = stab {
892 stab.rustc_depr = Some(rustc_depr);
894 span_err!(diagnostic, item_sp, E0549,
895 "rustc_deprecated attribute must be paired with \
896 either stable or unstable attribute");
900 // Merge the const-unstable info into the stability info
901 if let Some(rustc_const_unstable) = rustc_const_unstable {
902 if let Some(ref mut stab) = stab {
903 stab.rustc_const_unstable = Some(rustc_const_unstable);
905 span_err!(diagnostic, item_sp, E0630,
906 "rustc_const_unstable attribute must be paired with \
907 either stable or unstable attribute");
914 fn find_deprecation_generic<'a, I>(diagnostic: &Handler,
917 -> Option<Deprecation>
918 where I: Iterator<Item = &'a Attribute>
920 let mut depr: Option<Deprecation> = None;
922 'outer: for attr in attrs_iter {
923 if attr.path != "deprecated" {
930 span_err!(diagnostic, item_sp, E0550, "multiple deprecated attributes");
934 depr = if let Some(metas) = attr.meta_item_list() {
935 let get = |meta: &MetaItem, item: &mut Option<Symbol>| {
937 handle_errors(diagnostic, meta.span, AttrError::MultipleItem(meta.name()));
940 if let Some(v) = meta.value_str() {
944 span_err!(diagnostic, meta.span, E0551, "incorrect meta item");
949 let mut since = None;
952 if let NestedMetaItemKind::MetaItem(ref mi) = meta.node {
953 match &*mi.name().as_str() {
954 "since" => if !get(mi, &mut since) { continue 'outer },
955 "note" => if !get(mi, &mut note) { continue 'outer },
957 handle_errors(diagnostic, meta.span,
958 AttrError::UnknownMetaItem(mi.name()));
963 handle_errors(diagnostic, meta.span, AttrError::UnsupportedLiteral);
968 Some(Deprecation {since: since, note: note})
970 Some(Deprecation{since: None, note: None})
977 /// Find the first stability attribute. `None` if none exists.
978 pub fn find_stability(diagnostic: &Handler, attrs: &[Attribute],
979 item_sp: Span) -> Option<Stability> {
980 find_stability_generic(diagnostic, attrs.iter(), item_sp)
983 /// Find the deprecation attribute. `None` if none exists.
984 pub fn find_deprecation(diagnostic: &Handler, attrs: &[Attribute],
985 item_sp: Span) -> Option<Deprecation> {
986 find_deprecation_generic(diagnostic, attrs.iter(), item_sp)
990 /// Parse #[repr(...)] forms.
992 /// Valid repr contents: any of the primitive integral type names (see
993 /// `int_type_of_word`, below) to specify enum discriminant type; `C`, to use
994 /// the same discriminant size that the corresponding C enum would or C
995 /// structure layout, and `packed` to remove padding.
996 pub fn find_repr_attrs(diagnostic: &Handler, attr: &Attribute) -> Vec<ReprAttr> {
997 let mut acc = Vec::new();
998 if attr.path == "repr" {
999 if let Some(items) = attr.meta_item_list() {
1002 if !item.is_meta_item() {
1003 handle_errors(diagnostic, item.span, AttrError::UnsupportedLiteral);
1007 let mut recognised = false;
1008 if let Some(mi) = item.word() {
1009 let word = &*mi.name().as_str();
1010 let hint = match word {
1011 // Can't use "extern" because it's not a lexical identifier.
1012 "C" => Some(ReprExtern),
1013 "packed" => Some(ReprPacked),
1014 "simd" => Some(ReprSimd),
1015 _ => match int_type_of_word(word) {
1016 Some(ity) => Some(ReprInt(ity)),
1023 if let Some(h) = hint {
1027 } else if let Some((name, value)) = item.name_value_literal() {
1028 if name == "align" {
1030 let mut align_error = None;
1031 if let ast::LitKind::Int(align, ast::LitIntType::Unsuffixed) = value.node {
1032 if align.is_power_of_two() {
1033 // rustc::ty::layout::Align restricts align to <= 2147483647
1034 if align <= 2147483647 {
1035 acc.push(ReprAlign(align as u32));
1037 align_error = Some("larger than 2147483647");
1040 align_error = Some("not a power of two");
1043 align_error = Some("not an unsuffixed integer");
1045 if let Some(align_error) = align_error {
1046 span_err!(diagnostic, item.span, E0589,
1047 "invalid `repr(align)` attribute: {}", align_error);
1052 // Not a word we recognize
1053 span_err!(diagnostic, item.span, E0552,
1054 "unrecognized representation hint");
1062 fn int_type_of_word(s: &str) -> Option<IntType> {
1064 "i8" => Some(SignedInt(ast::IntTy::I8)),
1065 "u8" => Some(UnsignedInt(ast::UintTy::U8)),
1066 "i16" => Some(SignedInt(ast::IntTy::I16)),
1067 "u16" => Some(UnsignedInt(ast::UintTy::U16)),
1068 "i32" => Some(SignedInt(ast::IntTy::I32)),
1069 "u32" => Some(UnsignedInt(ast::UintTy::U32)),
1070 "i64" => Some(SignedInt(ast::IntTy::I64)),
1071 "u64" => Some(UnsignedInt(ast::UintTy::U64)),
1072 "i128" => Some(SignedInt(ast::IntTy::I128)),
1073 "u128" => Some(UnsignedInt(ast::UintTy::U128)),
1074 "isize" => Some(SignedInt(ast::IntTy::Isize)),
1075 "usize" => Some(UnsignedInt(ast::UintTy::Usize)),
1080 #[derive(PartialEq, Debug, RustcEncodable, RustcDecodable, Copy, Clone)]
1089 #[derive(Eq, Hash, PartialEq, Debug, RustcEncodable, RustcDecodable, Copy, Clone)]
1091 SignedInt(ast::IntTy),
1092 UnsignedInt(ast::UintTy)
1097 pub fn is_signed(self) -> bool {
1099 SignedInt(..) => true,
1100 UnsignedInt(..) => false
1106 fn tokens(&self) -> TokenStream {
1107 let ident = TokenTree::Token(self.span, Token::Ident(Ident::with_empty_ctxt(self.name)));
1108 TokenStream::concat(vec![ident.into(), self.node.tokens(self.span)])
1111 fn from_tokens<I>(tokens: &mut iter::Peekable<I>) -> Option<MetaItem>
1112 where I: Iterator<Item = TokenTree>,
1114 let (span, name) = match tokens.next() {
1115 Some(TokenTree::Token(span, Token::Ident(ident))) => (span, ident.name),
1116 Some(TokenTree::Token(_, Token::Interpolated(ref nt))) => match nt.0 {
1117 token::Nonterminal::NtIdent(ident) => (ident.span, ident.node.name),
1118 token::Nonterminal::NtMeta(ref meta) => return Some(meta.clone()),
1123 let list_closing_paren_pos = tokens.peek().map(|tt| tt.span().hi());
1124 let node = MetaItemKind::from_tokens(tokens)?;
1125 let hi = match node {
1126 MetaItemKind::NameValue(ref lit) => lit.span.hi(),
1127 MetaItemKind::List(..) => list_closing_paren_pos.unwrap_or(span.hi()),
1130 Some(MetaItem { name, node, span: span.with_hi(hi) })
1135 pub fn tokens(&self, span: Span) -> TokenStream {
1137 MetaItemKind::Word => TokenStream::empty(),
1138 MetaItemKind::NameValue(ref lit) => {
1139 TokenStream::concat(vec![TokenTree::Token(span, Token::Eq).into(), lit.tokens()])
1141 MetaItemKind::List(ref list) => {
1142 let mut tokens = Vec::new();
1143 for (i, item) in list.iter().enumerate() {
1145 tokens.push(TokenTree::Token(span, Token::Comma).into());
1147 tokens.push(item.node.tokens());
1149 TokenTree::Delimited(span, Delimited {
1150 delim: token::Paren,
1151 tts: TokenStream::concat(tokens).into(),
1157 fn from_tokens<I>(tokens: &mut iter::Peekable<I>) -> Option<MetaItemKind>
1158 where I: Iterator<Item = TokenTree>,
1160 let delimited = match tokens.peek().cloned() {
1161 Some(TokenTree::Token(_, token::Eq)) => {
1163 return if let Some(TokenTree::Token(span, token)) = tokens.next() {
1164 LitKind::from_token(token)
1165 .map(|lit| MetaItemKind::NameValue(Spanned { node: lit, span: span }))
1170 Some(TokenTree::Delimited(_, ref delimited)) if delimited.delim == token::Paren => {
1174 _ => return Some(MetaItemKind::Word),
1177 let mut tokens = delimited.into_trees().peekable();
1178 let mut result = Vec::new();
1179 while let Some(..) = tokens.peek() {
1180 let item = NestedMetaItemKind::from_tokens(&mut tokens)?;
1181 result.push(respan(item.span(), item));
1182 match tokens.next() {
1183 None | Some(TokenTree::Token(_, Token::Comma)) => {}
1187 Some(MetaItemKind::List(result))
1191 impl NestedMetaItemKind {
1192 fn span(&self) -> Span {
1194 NestedMetaItemKind::MetaItem(ref item) => item.span,
1195 NestedMetaItemKind::Literal(ref lit) => lit.span,
1199 fn tokens(&self) -> TokenStream {
1201 NestedMetaItemKind::MetaItem(ref item) => item.tokens(),
1202 NestedMetaItemKind::Literal(ref lit) => lit.tokens(),
1206 fn from_tokens<I>(tokens: &mut iter::Peekable<I>) -> Option<NestedMetaItemKind>
1207 where I: Iterator<Item = TokenTree>,
1209 if let Some(TokenTree::Token(span, token)) = tokens.peek().cloned() {
1210 if let Some(node) = LitKind::from_token(token) {
1212 return Some(NestedMetaItemKind::Literal(respan(span, node)));
1216 MetaItem::from_tokens(tokens).map(NestedMetaItemKind::MetaItem)
1221 fn tokens(&self) -> TokenStream {
1222 TokenTree::Token(self.span, self.node.token()).into()
1227 fn token(&self) -> Token {
1231 LitKind::Str(string, ast::StrStyle::Cooked) => {
1232 let mut escaped = String::new();
1233 for ch in string.as_str().chars() {
1234 escaped.extend(ch.escape_unicode());
1236 Token::Literal(token::Lit::Str_(Symbol::intern(&escaped)), None)
1238 LitKind::Str(string, ast::StrStyle::Raw(n)) => {
1239 Token::Literal(token::Lit::StrRaw(string, n), None)
1241 LitKind::ByteStr(ref bytes) => {
1242 let string = bytes.iter().cloned().flat_map(ascii::escape_default)
1243 .map(Into::<char>::into).collect::<String>();
1244 Token::Literal(token::Lit::ByteStr(Symbol::intern(&string)), None)
1246 LitKind::Byte(byte) => {
1247 let string: String = ascii::escape_default(byte).map(Into::<char>::into).collect();
1248 Token::Literal(token::Lit::Byte(Symbol::intern(&string)), None)
1250 LitKind::Char(ch) => {
1251 let string: String = ch.escape_default().map(Into::<char>::into).collect();
1252 Token::Literal(token::Lit::Char(Symbol::intern(&string)), None)
1254 LitKind::Int(n, ty) => {
1255 let suffix = match ty {
1256 ast::LitIntType::Unsigned(ty) => Some(Symbol::intern(ty.ty_to_string())),
1257 ast::LitIntType::Signed(ty) => Some(Symbol::intern(ty.ty_to_string())),
1258 ast::LitIntType::Unsuffixed => None,
1260 Token::Literal(token::Lit::Integer(Symbol::intern(&n.to_string())), suffix)
1262 LitKind::Float(symbol, ty) => {
1263 Token::Literal(token::Lit::Float(symbol), Some(Symbol::intern(ty.ty_to_string())))
1265 LitKind::FloatUnsuffixed(symbol) => Token::Literal(token::Lit::Float(symbol), None),
1266 LitKind::Bool(value) => Token::Ident(Ident::with_empty_ctxt(Symbol::intern(if value {
1274 fn from_token(token: Token) -> Option<LitKind> {
1276 Token::Ident(ident) if ident.name == "true" => Some(LitKind::Bool(true)),
1277 Token::Ident(ident) if ident.name == "false" => Some(LitKind::Bool(false)),
1278 Token::Interpolated(ref nt) => match nt.0 {
1279 token::NtExpr(ref v) => match v.node {
1280 ExprKind::Lit(ref lit) => Some(lit.node.clone()),
1285 Token::Literal(lit, suf) => {
1286 let (suffix_illegal, result) = parse::lit_token(lit, suf, None);
1287 if suffix_illegal && suf.is_some() {
1297 pub trait HasAttrs: Sized {
1298 fn attrs(&self) -> &[ast::Attribute];
1299 fn map_attrs<F: FnOnce(Vec<ast::Attribute>) -> Vec<ast::Attribute>>(self, f: F) -> Self;
1302 impl<T: HasAttrs> HasAttrs for Spanned<T> {
1303 fn attrs(&self) -> &[ast::Attribute] { self.node.attrs() }
1304 fn map_attrs<F: FnOnce(Vec<ast::Attribute>) -> Vec<ast::Attribute>>(self, f: F) -> Self {
1305 respan(self.span, self.node.map_attrs(f))
1309 impl HasAttrs for Vec<Attribute> {
1310 fn attrs(&self) -> &[Attribute] {
1313 fn map_attrs<F: FnOnce(Vec<Attribute>) -> Vec<Attribute>>(self, f: F) -> Self {
1318 impl HasAttrs for ThinVec<Attribute> {
1319 fn attrs(&self) -> &[Attribute] {
1322 fn map_attrs<F: FnOnce(Vec<Attribute>) -> Vec<Attribute>>(self, f: F) -> Self {
1323 f(self.into()).into()
1327 impl<T: HasAttrs + 'static> HasAttrs for P<T> {
1328 fn attrs(&self) -> &[Attribute] {
1331 fn map_attrs<F: FnOnce(Vec<Attribute>) -> Vec<Attribute>>(self, f: F) -> Self {
1332 self.map(|t| t.map_attrs(f))
1336 impl HasAttrs for StmtKind {
1337 fn attrs(&self) -> &[Attribute] {
1339 StmtKind::Local(ref local) => local.attrs(),
1340 StmtKind::Item(..) => &[],
1341 StmtKind::Expr(ref expr) | StmtKind::Semi(ref expr) => expr.attrs(),
1342 StmtKind::Mac(ref mac) => {
1343 let (_, _, ref attrs) = **mac;
1349 fn map_attrs<F: FnOnce(Vec<Attribute>) -> Vec<Attribute>>(self, f: F) -> Self {
1351 StmtKind::Local(local) => StmtKind::Local(local.map_attrs(f)),
1352 StmtKind::Item(..) => self,
1353 StmtKind::Expr(expr) => StmtKind::Expr(expr.map_attrs(f)),
1354 StmtKind::Semi(expr) => StmtKind::Semi(expr.map_attrs(f)),
1355 StmtKind::Mac(mac) => StmtKind::Mac(mac.map(|(mac, style, attrs)| {
1356 (mac, style, attrs.map_attrs(f))
1362 impl HasAttrs for Stmt {
1363 fn attrs(&self) -> &[ast::Attribute] { self.node.attrs() }
1364 fn map_attrs<F: FnOnce(Vec<ast::Attribute>) -> Vec<ast::Attribute>>(self, f: F) -> Self {
1365 Stmt { id: self.id, node: self.node.map_attrs(f), span: self.span }
1369 macro_rules! derive_has_attrs {
1370 ($($ty:path),*) => { $(
1371 impl HasAttrs for $ty {
1372 fn attrs(&self) -> &[Attribute] {
1376 fn map_attrs<F>(mut self, f: F) -> Self
1377 where F: FnOnce(Vec<Attribute>) -> Vec<Attribute>,
1379 self.attrs = self.attrs.map_attrs(f);
1387 Item, Expr, Local, ast::ForeignItem, ast::StructField, ast::ImplItem, ast::TraitItem, ast::Arm,
1388 ast::Field, ast::FieldPat, ast::Variant_