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};
39 UnknownMetaItem(Name),
42 MultipleStabilityLevels,
46 fn handle_errors(diag: &Handler, span: Span, error: AttrError) {
48 AttrError::MultipleItem(item) => span_err!(diag, span, E0538,
49 "multiple '{}' items", item),
50 AttrError::UnknownMetaItem(item) => span_err!(diag, span, E0541,
51 "unknown meta item '{}'", item),
52 AttrError::MissingSince => span_err!(diag, span, E0542, "missing 'since'"),
53 AttrError::MissingFeature => span_err!(diag, span, E0546, "missing 'feature'"),
54 AttrError::MultipleStabilityLevels => span_err!(diag, span, E0544,
55 "multiple stability levels"),
56 AttrError::UnsupportedLiteral => span_err!(diag, span, E0565, "unsupported literal"),
60 pub fn mark_used(attr: &Attribute) {
61 debug!("Marking {:?} as used.", attr);
62 let AttrId(id) = attr.id;
63 GLOBALS.with(|globals| {
64 let mut slot = globals.used_attrs.lock();
65 let idx = (id / 64) as usize;
67 if slot.len() <= idx {
68 slot.resize(idx + 1, 0);
70 slot[idx] |= 1 << shift;
74 pub fn is_used(attr: &Attribute) -> bool {
75 let AttrId(id) = attr.id;
76 GLOBALS.with(|globals| {
77 let slot = globals.used_attrs.lock();
78 let idx = (id / 64) as usize;
80 slot.get(idx).map(|bits| bits & (1 << shift) != 0)
85 pub fn mark_known(attr: &Attribute) {
86 debug!("Marking {:?} as known.", attr);
87 let AttrId(id) = attr.id;
88 GLOBALS.with(|globals| {
89 let mut slot = globals.known_attrs.lock();
90 let idx = (id / 64) as usize;
92 if slot.len() <= idx {
93 slot.resize(idx + 1, 0);
95 slot[idx] |= 1 << shift;
99 pub fn is_known(attr: &Attribute) -> bool {
100 let AttrId(id) = attr.id;
101 GLOBALS.with(|globals| {
102 let slot = globals.known_attrs.lock();
103 let idx = (id / 64) as usize;
105 slot.get(idx).map(|bits| bits & (1 << shift) != 0)
110 impl NestedMetaItem {
111 /// Returns the MetaItem if self is a NestedMetaItemKind::MetaItem.
112 pub fn meta_item(&self) -> Option<&MetaItem> {
114 NestedMetaItemKind::MetaItem(ref item) => Some(item),
119 /// Returns the Lit if self is a NestedMetaItemKind::Literal.
120 pub fn literal(&self) -> Option<&Lit> {
122 NestedMetaItemKind::Literal(ref lit) => Some(lit),
127 /// Returns the Span for `self`.
128 pub fn span(&self) -> Span {
132 /// Returns true if this list item is a MetaItem with a name of `name`.
133 pub fn check_name(&self, name: &str) -> bool {
134 self.meta_item().map_or(false, |meta_item| meta_item.check_name(name))
137 /// Returns the name of the meta item, e.g. `foo` in `#[foo]`,
138 /// `#[foo="bar"]` and `#[foo(bar)]`, if self is a MetaItem
139 pub fn name(&self) -> Option<Name> {
140 self.meta_item().and_then(|meta_item| Some(meta_item.name()))
143 /// Gets the string value if self is a MetaItem and the MetaItem is a
144 /// MetaItemKind::NameValue variant containing a string, otherwise None.
145 pub fn value_str(&self) -> Option<Symbol> {
146 self.meta_item().and_then(|meta_item| meta_item.value_str())
149 /// Returns a name and single literal value tuple of the MetaItem.
150 pub fn name_value_literal(&self) -> Option<(Name, &Lit)> {
151 self.meta_item().and_then(
152 |meta_item| meta_item.meta_item_list().and_then(
154 if meta_item_list.len() == 1 {
155 let nested_item = &meta_item_list[0];
156 if nested_item.is_literal() {
157 Some((meta_item.name(), nested_item.literal().unwrap()))
167 /// Returns a MetaItem if self is a MetaItem with Kind Word.
168 pub fn word(&self) -> Option<&MetaItem> {
169 self.meta_item().and_then(|meta_item| if meta_item.is_word() {
176 /// Gets a list of inner meta items from a list MetaItem type.
177 pub fn meta_item_list(&self) -> Option<&[NestedMetaItem]> {
178 self.meta_item().and_then(|meta_item| meta_item.meta_item_list())
181 /// Returns `true` if the variant is MetaItem.
182 pub fn is_meta_item(&self) -> bool {
183 self.meta_item().is_some()
186 /// Returns `true` if the variant is Literal.
187 pub fn is_literal(&self) -> bool {
188 self.literal().is_some()
191 /// Returns `true` if self is a MetaItem and the meta item is a word.
192 pub fn is_word(&self) -> bool {
193 self.word().is_some()
196 /// Returns `true` if self is a MetaItem and the meta item is a ValueString.
197 pub fn is_value_str(&self) -> bool {
198 self.value_str().is_some()
201 /// Returns `true` if self is a MetaItem and the meta item is a list.
202 pub fn is_meta_item_list(&self) -> bool {
203 self.meta_item_list().is_some()
208 pub fn check_name(&self, name: &str) -> bool {
209 let matches = self.path == name;
216 pub fn name(&self) -> Option<Name> {
217 match self.path.segments.len() {
218 1 => Some(self.path.segments[0].ident.name),
223 pub fn value_str(&self) -> Option<Symbol> {
224 self.meta().and_then(|meta| meta.value_str())
227 pub fn meta_item_list(&self) -> Option<Vec<NestedMetaItem>> {
229 Some(MetaItem { node: MetaItemKind::List(list), .. }) => Some(list),
234 pub fn is_word(&self) -> bool {
235 self.path.segments.len() == 1 && self.tokens.is_empty()
238 pub fn span(&self) -> Span {
242 pub fn is_meta_item_list(&self) -> bool {
243 self.meta_item_list().is_some()
246 /// Indicates if the attribute is a Value String.
247 pub fn is_value_str(&self) -> bool {
248 self.value_str().is_some()
253 pub fn name(&self) -> Name {
257 pub fn value_str(&self) -> Option<Symbol> {
259 MetaItemKind::NameValue(ref v) => {
261 LitKind::Str(ref s, _) => Some(*s),
269 pub fn meta_item_list(&self) -> Option<&[NestedMetaItem]> {
271 MetaItemKind::List(ref l) => Some(&l[..]),
276 pub fn is_word(&self) -> bool {
278 MetaItemKind::Word => true,
283 pub fn span(&self) -> Span { self.span }
285 pub fn check_name(&self, name: &str) -> bool {
289 pub fn is_value_str(&self) -> bool {
290 self.value_str().is_some()
293 pub fn is_meta_item_list(&self) -> bool {
294 self.meta_item_list().is_some()
299 /// Extract the MetaItem from inside this Attribute.
300 pub fn meta(&self) -> Option<MetaItem> {
301 let mut tokens = self.tokens.trees().peekable();
303 name: match self.path.segments.len() {
304 1 => self.path.segments[0].ident.name,
307 node: if let Some(node) = MetaItemKind::from_tokens(&mut tokens) {
308 if tokens.peek().is_some() {
319 pub fn parse<'a, T, F>(&self, sess: &'a ParseSess, mut f: F) -> PResult<'a, T>
320 where F: FnMut(&mut Parser<'a>) -> PResult<'a, T>,
322 let mut parser = Parser::new(sess, self.tokens.clone(), None, false, false);
323 let result = f(&mut parser)?;
324 if parser.token != token::Eof {
325 parser.unexpected()?;
330 pub fn parse_list<'a, T, F>(&self, sess: &'a ParseSess, mut f: F) -> PResult<'a, Vec<T>>
331 where F: FnMut(&mut Parser<'a>) -> PResult<'a, T>,
333 if self.tokens.is_empty() {
334 return Ok(Vec::new());
336 self.parse(sess, |parser| {
337 parser.expect(&token::OpenDelim(token::Paren))?;
338 let mut list = Vec::new();
339 while !parser.eat(&token::CloseDelim(token::Paren)) {
340 list.push(f(parser)?);
341 if !parser.eat(&token::Comma) {
342 parser.expect(&token::CloseDelim(token::Paren))?;
350 pub fn parse_meta<'a>(&self, sess: &'a ParseSess) -> PResult<'a, MetaItem> {
351 if self.path.segments.len() > 1 {
352 sess.span_diagnostic.span_err(self.path.span, "expected ident, found path");
356 name: self.path.segments.last().unwrap().ident.name,
357 node: self.parse(sess, |parser| parser.parse_meta_item_kind())?,
362 /// Convert self to a normal #[doc="foo"] comment, if it is a
363 /// comment like `///` or `/** */`. (Returns self unchanged for
364 /// non-sugared doc attributes.)
365 pub fn with_desugared_doc<T, F>(&self, f: F) -> T where
366 F: FnOnce(&Attribute) -> T,
368 if self.is_sugared_doc {
369 let comment = self.value_str().unwrap();
370 let meta = mk_name_value_item_str(
371 Symbol::intern("doc"),
372 Symbol::intern(&strip_doc_comment_decoration(&comment.as_str())));
373 let mut attr = if self.style == ast::AttrStyle::Outer {
374 mk_attr_outer(self.span, self.id, meta)
376 mk_attr_inner(self.span, self.id, meta)
378 attr.is_sugared_doc = true;
388 pub fn mk_name_value_item_str(name: Name, value: Symbol) -> MetaItem {
389 let value_lit = dummy_spanned(LitKind::Str(value, ast::StrStyle::Cooked));
390 mk_spanned_name_value_item(DUMMY_SP, name, value_lit)
393 pub fn mk_name_value_item(name: Name, value: ast::Lit) -> MetaItem {
394 mk_spanned_name_value_item(DUMMY_SP, name, value)
397 pub fn mk_list_item(name: Name, items: Vec<NestedMetaItem>) -> MetaItem {
398 mk_spanned_list_item(DUMMY_SP, name, items)
401 pub fn mk_list_word_item(name: Name) -> ast::NestedMetaItem {
402 dummy_spanned(NestedMetaItemKind::MetaItem(mk_spanned_word_item(DUMMY_SP, name)))
405 pub fn mk_word_item(name: Name) -> MetaItem {
406 mk_spanned_word_item(DUMMY_SP, name)
409 pub fn mk_spanned_name_value_item(sp: Span, name: Name, value: ast::Lit) -> MetaItem {
410 MetaItem { span: sp, name: name, node: MetaItemKind::NameValue(value) }
413 pub fn mk_spanned_list_item(sp: Span, name: Name, items: Vec<NestedMetaItem>) -> MetaItem {
414 MetaItem { span: sp, name: name, node: MetaItemKind::List(items) }
417 pub fn mk_spanned_word_item(sp: Span, name: Name) -> MetaItem {
418 MetaItem { span: sp, name: name, node: MetaItemKind::Word }
421 pub fn mk_attr_id() -> AttrId {
422 use std::sync::atomic::AtomicUsize;
423 use std::sync::atomic::Ordering;
425 static NEXT_ATTR_ID: AtomicUsize = AtomicUsize::new(0);
427 let id = NEXT_ATTR_ID.fetch_add(1, Ordering::SeqCst);
428 assert!(id != ::std::usize::MAX);
432 /// Returns an inner attribute with the given value.
433 pub fn mk_attr_inner(span: Span, id: AttrId, item: MetaItem) -> Attribute {
434 mk_spanned_attr_inner(span, id, item)
437 /// Returns an inner attribute with the given value and span.
438 pub fn mk_spanned_attr_inner(sp: Span, id: AttrId, item: MetaItem) -> Attribute {
441 style: ast::AttrStyle::Inner,
442 path: ast::Path::from_ident(item.span, ast::Ident::with_empty_ctxt(item.name)),
443 tokens: item.node.tokens(item.span),
444 is_sugared_doc: false,
450 /// Returns an outer attribute with the given value.
451 pub fn mk_attr_outer(span: Span, id: AttrId, item: MetaItem) -> Attribute {
452 mk_spanned_attr_outer(span, id, item)
455 /// Returns an outer attribute with the given value and span.
456 pub fn mk_spanned_attr_outer(sp: Span, id: AttrId, item: MetaItem) -> Attribute {
459 style: ast::AttrStyle::Outer,
460 path: ast::Path::from_ident(item.span, ast::Ident::with_empty_ctxt(item.name)),
461 tokens: item.node.tokens(item.span),
462 is_sugared_doc: false,
467 pub fn mk_sugared_doc_attr(id: AttrId, text: Symbol, span: Span) -> Attribute {
468 let style = doc_comment_style(&text.as_str());
469 let lit = respan(span, LitKind::Str(text, ast::StrStyle::Cooked));
473 path: ast::Path::from_ident(span, ast::Ident::from_str("doc")),
474 tokens: MetaItemKind::NameValue(lit).tokens(span),
475 is_sugared_doc: true,
480 pub fn list_contains_name(items: &[NestedMetaItem], name: &str) -> bool {
481 items.iter().any(|item| {
482 item.check_name(name)
486 pub fn contains_name(attrs: &[Attribute], name: &str) -> bool {
487 attrs.iter().any(|item| {
488 item.check_name(name)
492 pub fn find_by_name<'a>(attrs: &'a [Attribute], name: &str) -> Option<&'a Attribute> {
493 attrs.iter().find(|attr| attr.check_name(name))
496 pub fn first_attr_value_str_by_name(attrs: &[Attribute], name: &str) -> Option<Symbol> {
498 .find(|at| at.check_name(name))
499 .and_then(|at| at.value_str())
502 /// Check if `attrs` contains an attribute like `#![feature(feature_name)]`.
503 /// This will not perform any "sanity checks" on the form of the attributes.
504 pub fn contains_feature_attr(attrs: &[Attribute], feature_name: &str) -> bool {
505 attrs.iter().any(|item| {
506 item.check_name("feature") &&
507 item.meta_item_list().map(|list| {
508 list.iter().any(|mi| {
509 mi.word().map(|w| w.name() == feature_name)
516 /* Higher-level applications */
518 pub fn find_crate_name(attrs: &[Attribute]) -> Option<Symbol> {
519 first_attr_value_str_by_name(attrs, "crate_name")
522 #[derive(Copy, Clone, Hash, PartialEq, RustcEncodable, RustcDecodable)]
523 pub enum InlineAttr {
530 #[derive(Copy, Clone, PartialEq)]
531 pub enum UnwindAttr {
536 /// Determine what `#[unwind]` attribute is present in `attrs`, if any.
537 pub fn find_unwind_attr(diagnostic: Option<&Handler>, attrs: &[Attribute]) -> Option<UnwindAttr> {
538 let syntax_error = |attr: &Attribute| {
541 span_err!(d, attr.span, E0633, "malformed `#[unwind]` attribute");
546 attrs.iter().fold(None, |ia, attr| {
547 if attr.path != "unwind" {
550 let meta = match attr.meta() {
551 Some(meta) => meta.node,
555 MetaItemKind::Word => {
558 MetaItemKind::List(ref items) => {
560 if items.len() != 1 {
562 } else if list_contains_name(&items[..], "allowed") {
563 Some(UnwindAttr::Allowed)
564 } else if list_contains_name(&items[..], "aborts") {
565 Some(UnwindAttr::Aborts)
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, `packed` to remove padding, and `transparent` to elegate representation
996 /// concerns to the only non-ZST field.
997 pub fn find_repr_attrs(diagnostic: &Handler, attr: &Attribute) -> Vec<ReprAttr> {
998 let mut acc = Vec::new();
999 if attr.path == "repr" {
1000 if let Some(items) = attr.meta_item_list() {
1003 if !item.is_meta_item() {
1004 handle_errors(diagnostic, item.span, AttrError::UnsupportedLiteral);
1008 let mut recognised = false;
1009 if let Some(mi) = item.word() {
1010 let word = &*mi.name().as_str();
1011 let hint = match word {
1013 "packed" => Some(ReprPacked),
1014 "simd" => Some(ReprSimd),
1015 "transparent" => Some(ReprTransparent),
1016 _ => match int_type_of_word(word) {
1017 Some(ity) => Some(ReprInt(ity)),
1024 if let Some(h) = hint {
1028 } else if let Some((name, value)) = item.name_value_literal() {
1029 if name == "align" {
1031 let mut align_error = None;
1032 if let ast::LitKind::Int(align, ast::LitIntType::Unsuffixed) = value.node {
1033 if align.is_power_of_two() {
1034 // rustc::ty::layout::Align restricts align to <= 2147483647
1035 if align <= 2147483647 {
1036 acc.push(ReprAlign(align as u32));
1038 align_error = Some("larger than 2147483647");
1041 align_error = Some("not a power of two");
1044 align_error = Some("not an unsuffixed integer");
1046 if let Some(align_error) = align_error {
1047 span_err!(diagnostic, item.span, E0589,
1048 "invalid `repr(align)` attribute: {}", align_error);
1053 // Not a word we recognize
1054 span_err!(diagnostic, item.span, E0552,
1055 "unrecognized representation hint");
1063 fn int_type_of_word(s: &str) -> Option<IntType> {
1065 "i8" => Some(SignedInt(ast::IntTy::I8)),
1066 "u8" => Some(UnsignedInt(ast::UintTy::U8)),
1067 "i16" => Some(SignedInt(ast::IntTy::I16)),
1068 "u16" => Some(UnsignedInt(ast::UintTy::U16)),
1069 "i32" => Some(SignedInt(ast::IntTy::I32)),
1070 "u32" => Some(UnsignedInt(ast::UintTy::U32)),
1071 "i64" => Some(SignedInt(ast::IntTy::I64)),
1072 "u64" => Some(UnsignedInt(ast::UintTy::U64)),
1073 "i128" => Some(SignedInt(ast::IntTy::I128)),
1074 "u128" => Some(UnsignedInt(ast::UintTy::U128)),
1075 "isize" => Some(SignedInt(ast::IntTy::Isize)),
1076 "usize" => Some(UnsignedInt(ast::UintTy::Usize)),
1081 #[derive(PartialEq, Debug, RustcEncodable, RustcDecodable, Copy, Clone)]
1091 #[derive(Eq, Hash, PartialEq, Debug, RustcEncodable, RustcDecodable, Copy, Clone)]
1093 SignedInt(ast::IntTy),
1094 UnsignedInt(ast::UintTy)
1099 pub fn is_signed(self) -> bool {
1101 SignedInt(..) => true,
1102 UnsignedInt(..) => false
1108 fn tokens(&self) -> TokenStream {
1109 let ident = TokenTree::Token(self.span,
1110 Token::from_ast_ident(Ident::with_empty_ctxt(self.name)));
1111 TokenStream::concat(vec![ident.into(), self.node.tokens(self.span)])
1114 fn from_tokens<I>(tokens: &mut iter::Peekable<I>) -> Option<MetaItem>
1115 where I: Iterator<Item = TokenTree>,
1117 let (span, name) = match tokens.next() {
1118 Some(TokenTree::Token(span, Token::Ident(ident, _))) => (span, ident.name),
1119 Some(TokenTree::Token(_, Token::Interpolated(ref nt))) => match nt.0 {
1120 token::Nonterminal::NtIdent(ident, _) => (ident.span, ident.node.name),
1121 token::Nonterminal::NtMeta(ref meta) => return Some(meta.clone()),
1126 let list_closing_paren_pos = tokens.peek().map(|tt| tt.span().hi());
1127 let node = MetaItemKind::from_tokens(tokens)?;
1128 let hi = match node {
1129 MetaItemKind::NameValue(ref lit) => lit.span.hi(),
1130 MetaItemKind::List(..) => list_closing_paren_pos.unwrap_or(span.hi()),
1133 Some(MetaItem { name, node, span: span.with_hi(hi) })
1138 pub fn tokens(&self, span: Span) -> TokenStream {
1140 MetaItemKind::Word => TokenStream::empty(),
1141 MetaItemKind::NameValue(ref lit) => {
1142 TokenStream::concat(vec![TokenTree::Token(span, Token::Eq).into(), lit.tokens()])
1144 MetaItemKind::List(ref list) => {
1145 let mut tokens = Vec::new();
1146 for (i, item) in list.iter().enumerate() {
1148 tokens.push(TokenTree::Token(span, Token::Comma).into());
1150 tokens.push(item.node.tokens());
1152 TokenTree::Delimited(span, Delimited {
1153 delim: token::Paren,
1154 tts: TokenStream::concat(tokens).into(),
1160 fn from_tokens<I>(tokens: &mut iter::Peekable<I>) -> Option<MetaItemKind>
1161 where I: Iterator<Item = TokenTree>,
1163 let delimited = match tokens.peek().cloned() {
1164 Some(TokenTree::Token(_, token::Eq)) => {
1166 return if let Some(TokenTree::Token(span, token)) = tokens.next() {
1167 LitKind::from_token(token)
1168 .map(|lit| MetaItemKind::NameValue(Spanned { node: lit, span: span }))
1173 Some(TokenTree::Delimited(_, ref delimited)) if delimited.delim == token::Paren => {
1177 _ => return Some(MetaItemKind::Word),
1180 let mut tokens = delimited.into_trees().peekable();
1181 let mut result = Vec::new();
1182 while let Some(..) = tokens.peek() {
1183 let item = NestedMetaItemKind::from_tokens(&mut tokens)?;
1184 result.push(respan(item.span(), item));
1185 match tokens.next() {
1186 None | Some(TokenTree::Token(_, Token::Comma)) => {}
1190 Some(MetaItemKind::List(result))
1194 impl NestedMetaItemKind {
1195 fn span(&self) -> Span {
1197 NestedMetaItemKind::MetaItem(ref item) => item.span,
1198 NestedMetaItemKind::Literal(ref lit) => lit.span,
1202 fn tokens(&self) -> TokenStream {
1204 NestedMetaItemKind::MetaItem(ref item) => item.tokens(),
1205 NestedMetaItemKind::Literal(ref lit) => lit.tokens(),
1209 fn from_tokens<I>(tokens: &mut iter::Peekable<I>) -> Option<NestedMetaItemKind>
1210 where I: Iterator<Item = TokenTree>,
1212 if let Some(TokenTree::Token(span, token)) = tokens.peek().cloned() {
1213 if let Some(node) = LitKind::from_token(token) {
1215 return Some(NestedMetaItemKind::Literal(respan(span, node)));
1219 MetaItem::from_tokens(tokens).map(NestedMetaItemKind::MetaItem)
1224 fn tokens(&self) -> TokenStream {
1225 TokenTree::Token(self.span, self.node.token()).into()
1230 fn token(&self) -> Token {
1234 LitKind::Str(string, ast::StrStyle::Cooked) => {
1235 let mut escaped = String::new();
1236 for ch in string.as_str().chars() {
1237 escaped.extend(ch.escape_unicode());
1239 Token::Literal(token::Lit::Str_(Symbol::intern(&escaped)), None)
1241 LitKind::Str(string, ast::StrStyle::Raw(n)) => {
1242 Token::Literal(token::Lit::StrRaw(string, n), None)
1244 LitKind::ByteStr(ref bytes) => {
1245 let string = bytes.iter().cloned().flat_map(ascii::escape_default)
1246 .map(Into::<char>::into).collect::<String>();
1247 Token::Literal(token::Lit::ByteStr(Symbol::intern(&string)), None)
1249 LitKind::Byte(byte) => {
1250 let string: String = ascii::escape_default(byte).map(Into::<char>::into).collect();
1251 Token::Literal(token::Lit::Byte(Symbol::intern(&string)), None)
1253 LitKind::Char(ch) => {
1254 let string: String = ch.escape_default().map(Into::<char>::into).collect();
1255 Token::Literal(token::Lit::Char(Symbol::intern(&string)), None)
1257 LitKind::Int(n, ty) => {
1258 let suffix = match ty {
1259 ast::LitIntType::Unsigned(ty) => Some(Symbol::intern(ty.ty_to_string())),
1260 ast::LitIntType::Signed(ty) => Some(Symbol::intern(ty.ty_to_string())),
1261 ast::LitIntType::Unsuffixed => None,
1263 Token::Literal(token::Lit::Integer(Symbol::intern(&n.to_string())), suffix)
1265 LitKind::Float(symbol, ty) => {
1266 Token::Literal(token::Lit::Float(symbol), Some(Symbol::intern(ty.ty_to_string())))
1268 LitKind::FloatUnsuffixed(symbol) => Token::Literal(token::Lit::Float(symbol), None),
1269 LitKind::Bool(value) => Token::Ident(Ident::with_empty_ctxt(Symbol::intern(if value {
1277 fn from_token(token: Token) -> Option<LitKind> {
1279 Token::Ident(ident, false) if ident.name == "true" => Some(LitKind::Bool(true)),
1280 Token::Ident(ident, false) if ident.name == "false" => Some(LitKind::Bool(false)),
1281 Token::Interpolated(ref nt) => match nt.0 {
1282 token::NtExpr(ref v) => match v.node {
1283 ExprKind::Lit(ref lit) => Some(lit.node.clone()),
1288 Token::Literal(lit, suf) => {
1289 let (suffix_illegal, result) = parse::lit_token(lit, suf, None);
1290 if suffix_illegal && suf.is_some() {
1300 pub trait HasAttrs: Sized {
1301 fn attrs(&self) -> &[ast::Attribute];
1302 fn map_attrs<F: FnOnce(Vec<ast::Attribute>) -> Vec<ast::Attribute>>(self, f: F) -> Self;
1305 impl<T: HasAttrs> HasAttrs for Spanned<T> {
1306 fn attrs(&self) -> &[ast::Attribute] { self.node.attrs() }
1307 fn map_attrs<F: FnOnce(Vec<ast::Attribute>) -> Vec<ast::Attribute>>(self, f: F) -> Self {
1308 respan(self.span, self.node.map_attrs(f))
1312 impl HasAttrs for Vec<Attribute> {
1313 fn attrs(&self) -> &[Attribute] {
1316 fn map_attrs<F: FnOnce(Vec<Attribute>) -> Vec<Attribute>>(self, f: F) -> Self {
1321 impl HasAttrs for ThinVec<Attribute> {
1322 fn attrs(&self) -> &[Attribute] {
1325 fn map_attrs<F: FnOnce(Vec<Attribute>) -> Vec<Attribute>>(self, f: F) -> Self {
1326 f(self.into()).into()
1330 impl<T: HasAttrs + 'static> HasAttrs for P<T> {
1331 fn attrs(&self) -> &[Attribute] {
1334 fn map_attrs<F: FnOnce(Vec<Attribute>) -> Vec<Attribute>>(self, f: F) -> Self {
1335 self.map(|t| t.map_attrs(f))
1339 impl HasAttrs for StmtKind {
1340 fn attrs(&self) -> &[Attribute] {
1342 StmtKind::Local(ref local) => local.attrs(),
1343 StmtKind::Item(..) => &[],
1344 StmtKind::Expr(ref expr) | StmtKind::Semi(ref expr) => expr.attrs(),
1345 StmtKind::Mac(ref mac) => {
1346 let (_, _, ref attrs) = **mac;
1352 fn map_attrs<F: FnOnce(Vec<Attribute>) -> Vec<Attribute>>(self, f: F) -> Self {
1354 StmtKind::Local(local) => StmtKind::Local(local.map_attrs(f)),
1355 StmtKind::Item(..) => self,
1356 StmtKind::Expr(expr) => StmtKind::Expr(expr.map_attrs(f)),
1357 StmtKind::Semi(expr) => StmtKind::Semi(expr.map_attrs(f)),
1358 StmtKind::Mac(mac) => StmtKind::Mac(mac.map(|(mac, style, attrs)| {
1359 (mac, style, attrs.map_attrs(f))
1365 impl HasAttrs for Stmt {
1366 fn attrs(&self) -> &[ast::Attribute] { self.node.attrs() }
1367 fn map_attrs<F: FnOnce(Vec<ast::Attribute>) -> Vec<ast::Attribute>>(self, f: F) -> Self {
1368 Stmt { id: self.id, node: self.node.map_attrs(f), span: self.span }
1372 macro_rules! derive_has_attrs {
1373 ($($ty:path),*) => { $(
1374 impl HasAttrs for $ty {
1375 fn attrs(&self) -> &[Attribute] {
1379 fn map_attrs<F>(mut self, f: F) -> Self
1380 where F: FnOnce(Vec<Attribute>) -> Vec<Attribute>,
1382 self.attrs = self.attrs.map_attrs(f);
1390 Item, Expr, Local, ast::ForeignItem, ast::StructField, ast::ImplItem, ast::TraitItem, ast::Arm,
1391 ast::Field, ast::FieldPat, ast::Variant_