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, Cell};
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 MetaItem if self is a MetaItem with Kind Word.
151 pub fn word(&self) -> Option<&MetaItem> {
152 self.meta_item().and_then(|meta_item| if meta_item.is_word() {
159 /// Gets a list of inner meta items from a list MetaItem type.
160 pub fn meta_item_list(&self) -> Option<&[NestedMetaItem]> {
161 self.meta_item().and_then(|meta_item| meta_item.meta_item_list())
164 /// Returns `true` if the variant is MetaItem.
165 pub fn is_meta_item(&self) -> bool {
166 self.meta_item().is_some()
169 /// Returns `true` if the variant is Literal.
170 pub fn is_literal(&self) -> bool {
171 self.literal().is_some()
174 /// Returns `true` if self is a MetaItem and the meta item is a word.
175 pub fn is_word(&self) -> bool {
176 self.word().is_some()
179 /// Returns `true` if self is a MetaItem and the meta item is a ValueString.
180 pub fn is_value_str(&self) -> bool {
181 self.value_str().is_some()
184 /// Returns `true` if self is a MetaItem and the meta item is a list.
185 pub fn is_meta_item_list(&self) -> bool {
186 self.meta_item_list().is_some()
191 pub fn check_name(&self, name: &str) -> bool {
192 let matches = self.path == name;
199 pub fn name(&self) -> Option<Name> {
200 match self.path.segments.len() {
201 1 => Some(self.path.segments[0].identifier.name),
206 pub fn value_str(&self) -> Option<Symbol> {
207 self.meta().and_then(|meta| meta.value_str())
210 pub fn meta_item_list(&self) -> Option<Vec<NestedMetaItem>> {
212 Some(MetaItem { node: MetaItemKind::List(list), .. }) => Some(list),
217 pub fn is_word(&self) -> bool {
218 self.path.segments.len() == 1 && self.tokens.is_empty()
221 pub fn span(&self) -> Span {
225 pub fn is_meta_item_list(&self) -> bool {
226 self.meta_item_list().is_some()
229 /// Indicates if the attribute is a Value String.
230 pub fn is_value_str(&self) -> bool {
231 self.value_str().is_some()
236 pub fn name(&self) -> Name {
240 pub fn value_str(&self) -> Option<Symbol> {
242 MetaItemKind::NameValue(ref v) => {
244 LitKind::Str(ref s, _) => Some((*s).clone()),
252 pub fn meta_item_list(&self) -> Option<&[NestedMetaItem]> {
254 MetaItemKind::List(ref l) => Some(&l[..]),
259 pub fn is_word(&self) -> bool {
261 MetaItemKind::Word => true,
266 pub fn span(&self) -> Span { self.span }
268 pub fn check_name(&self, name: &str) -> bool {
272 pub fn is_value_str(&self) -> bool {
273 self.value_str().is_some()
276 pub fn is_meta_item_list(&self) -> bool {
277 self.meta_item_list().is_some()
282 /// Extract the MetaItem from inside this Attribute.
283 pub fn meta(&self) -> Option<MetaItem> {
284 let mut tokens = self.tokens.trees().peekable();
286 name: match self.path.segments.len() {
287 1 => self.path.segments[0].identifier.name,
290 node: if let Some(node) = MetaItemKind::from_tokens(&mut tokens) {
291 if tokens.peek().is_some() {
302 pub fn parse<'a, T, F>(&self, sess: &'a ParseSess, mut f: F) -> PResult<'a, T>
303 where F: FnMut(&mut Parser<'a>) -> PResult<'a, T>,
305 let mut parser = Parser::new(sess, self.tokens.clone(), None, false);
306 let result = f(&mut parser)?;
307 if parser.token != token::Eof {
308 parser.unexpected()?;
313 pub fn parse_list<'a, T, F>(&self, sess: &'a ParseSess, mut f: F) -> PResult<'a, Vec<T>>
314 where F: FnMut(&mut Parser<'a>) -> PResult<'a, T>,
316 if self.tokens.is_empty() {
317 return Ok(Vec::new());
319 self.parse(sess, |parser| {
320 parser.expect(&token::OpenDelim(token::Paren))?;
321 let mut list = Vec::new();
322 while !parser.eat(&token::CloseDelim(token::Paren)) {
323 list.push(f(parser)?);
324 if !parser.eat(&token::Comma) {
325 parser.expect(&token::CloseDelim(token::Paren))?;
333 pub fn parse_meta<'a>(&self, sess: &'a ParseSess) -> PResult<'a, MetaItem> {
334 if self.path.segments.len() > 1 {
335 sess.span_diagnostic.span_err(self.path.span, "expected ident, found path");
339 name: self.path.segments.last().unwrap().identifier.name,
340 node: self.parse(sess, |parser| parser.parse_meta_item_kind())?,
345 /// Convert self to a normal #[doc="foo"] comment, if it is a
346 /// comment like `///` or `/** */`. (Returns self unchanged for
347 /// non-sugared doc attributes.)
348 pub fn with_desugared_doc<T, F>(&self, f: F) -> T where
349 F: FnOnce(&Attribute) -> T,
351 if self.is_sugared_doc {
352 let comment = self.value_str().unwrap();
353 let meta = mk_name_value_item_str(
354 Symbol::intern("doc"),
355 Symbol::intern(&strip_doc_comment_decoration(&comment.as_str())));
356 if self.style == ast::AttrStyle::Outer {
357 f(&mk_attr_outer(self.span, self.id, meta))
359 f(&mk_attr_inner(self.span, self.id, meta))
369 pub fn mk_name_value_item_str(name: Name, value: Symbol) -> MetaItem {
370 let value_lit = dummy_spanned(LitKind::Str(value, ast::StrStyle::Cooked));
371 mk_spanned_name_value_item(DUMMY_SP, name, value_lit)
374 pub fn mk_name_value_item(name: Name, value: ast::Lit) -> MetaItem {
375 mk_spanned_name_value_item(DUMMY_SP, name, value)
378 pub fn mk_list_item(name: Name, items: Vec<NestedMetaItem>) -> MetaItem {
379 mk_spanned_list_item(DUMMY_SP, name, items)
382 pub fn mk_list_word_item(name: Name) -> ast::NestedMetaItem {
383 dummy_spanned(NestedMetaItemKind::MetaItem(mk_spanned_word_item(DUMMY_SP, name)))
386 pub fn mk_word_item(name: Name) -> MetaItem {
387 mk_spanned_word_item(DUMMY_SP, name)
390 pub fn mk_spanned_name_value_item(sp: Span, name: Name, value: ast::Lit) -> MetaItem {
391 MetaItem { span: sp, name: name, node: MetaItemKind::NameValue(value) }
394 pub fn mk_spanned_list_item(sp: Span, name: Name, items: Vec<NestedMetaItem>) -> MetaItem {
395 MetaItem { span: sp, name: name, node: MetaItemKind::List(items) }
398 pub fn mk_spanned_word_item(sp: Span, name: Name) -> MetaItem {
399 MetaItem { span: sp, name: name, node: MetaItemKind::Word }
404 thread_local! { static NEXT_ATTR_ID: Cell<usize> = Cell::new(0) }
406 pub fn mk_attr_id() -> AttrId {
407 let id = NEXT_ATTR_ID.with(|slot| {
415 /// Returns an inner attribute with the given value.
416 pub fn mk_attr_inner(span: Span, id: AttrId, item: MetaItem) -> Attribute {
417 mk_spanned_attr_inner(span, id, item)
420 /// Returns an innter attribute with the given value and span.
421 pub fn mk_spanned_attr_inner(sp: Span, id: AttrId, item: MetaItem) -> Attribute {
424 style: ast::AttrStyle::Inner,
425 path: ast::Path::from_ident(item.span, ast::Ident::with_empty_ctxt(item.name)),
426 tokens: item.node.tokens(item.span),
427 is_sugared_doc: false,
433 /// Returns an outer attribute with the given value.
434 pub fn mk_attr_outer(span: Span, id: AttrId, item: MetaItem) -> Attribute {
435 mk_spanned_attr_outer(span, id, item)
438 /// Returns an outer attribute with the given value and span.
439 pub fn mk_spanned_attr_outer(sp: Span, id: AttrId, item: MetaItem) -> Attribute {
442 style: ast::AttrStyle::Outer,
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,
450 pub fn mk_sugared_doc_attr(id: AttrId, text: Symbol, span: Span) -> Attribute {
451 let style = doc_comment_style(&text.as_str());
452 let lit = respan(span, LitKind::Str(text, ast::StrStyle::Cooked));
456 path: ast::Path::from_ident(span, ast::Ident::from_str("doc")),
457 tokens: MetaItemKind::NameValue(lit).tokens(span),
458 is_sugared_doc: true,
463 pub fn list_contains_name(items: &[NestedMetaItem], name: &str) -> bool {
464 items.iter().any(|item| {
465 item.check_name(name)
469 pub fn contains_name(attrs: &[Attribute], name: &str) -> bool {
470 attrs.iter().any(|item| {
471 item.check_name(name)
475 pub fn first_attr_value_str_by_name(attrs: &[Attribute], name: &str) -> Option<Symbol> {
477 .find(|at| at.check_name(name))
478 .and_then(|at| at.value_str())
481 /* Higher-level applications */
483 pub fn find_crate_name(attrs: &[Attribute]) -> Option<Symbol> {
484 first_attr_value_str_by_name(attrs, "crate_name")
487 /// Find the value of #[export_name=*] attribute and check its validity.
488 pub fn find_export_name_attr(diag: &Handler, attrs: &[Attribute]) -> Option<Symbol> {
489 attrs.iter().fold(None, |ia,attr| {
490 if attr.check_name("export_name") {
491 if let s@Some(_) = attr.value_str() {
494 struct_span_err!(diag, attr.span, E0558,
495 "export_name attribute has invalid format")
496 .span_label(attr.span,
497 &format!("did you mean #[export_name=\"*\"]?"))
507 pub fn contains_extern_indicator(diag: &Handler, attrs: &[Attribute]) -> bool {
508 contains_name(attrs, "no_mangle") ||
509 find_export_name_attr(diag, attrs).is_some()
512 #[derive(Copy, Clone, PartialEq)]
513 pub enum InlineAttr {
520 /// Determine what `#[inline]` attribute is present in `attrs`, if any.
521 pub fn find_inline_attr(diagnostic: Option<&Handler>, attrs: &[Attribute]) -> InlineAttr {
522 attrs.iter().fold(InlineAttr::None, |ia, attr| {
523 if attr.path != "inline" {
526 let meta = match attr.meta() {
527 Some(meta) => meta.node,
531 MetaItemKind::Word => {
535 MetaItemKind::List(ref items) => {
537 if items.len() != 1 {
538 diagnostic.map(|d|{ span_err!(d, attr.span, E0534, "expected one argument"); });
540 } else if list_contains_name(&items[..], "always") {
542 } else if list_contains_name(&items[..], "never") {
546 span_err!(d, items[0].span, E0535, "invalid argument");
557 /// True if `#[inline]` or `#[inline(always)]` is present in `attrs`.
558 pub fn requests_inline(attrs: &[Attribute]) -> bool {
559 match find_inline_attr(None, attrs) {
560 InlineAttr::Hint | InlineAttr::Always => true,
561 InlineAttr::None | InlineAttr::Never => false,
565 /// Tests if a cfg-pattern matches the cfg set
566 pub fn cfg_matches(cfg: &ast::MetaItem, sess: &ParseSess, features: Option<&Features>) -> bool {
568 ast::MetaItemKind::List(ref mis) => {
569 for mi in mis.iter() {
570 if !mi.is_meta_item() {
571 handle_errors(&sess.span_diagnostic, mi.span, AttrError::UnsupportedLiteral);
576 // The unwraps below may look dangerous, but we've already asserted
577 // that they won't fail with the loop above.
578 match &*cfg.name.as_str() {
579 "any" => mis.iter().any(|mi| {
580 cfg_matches(mi.meta_item().unwrap(), sess, features)
582 "all" => mis.iter().all(|mi| {
583 cfg_matches(mi.meta_item().unwrap(), sess, features)
587 span_err!(sess.span_diagnostic, cfg.span, E0536, "expected 1 cfg-pattern");
591 !cfg_matches(mis[0].meta_item().unwrap(), sess, features)
594 span_err!(sess.span_diagnostic, cfg.span, E0537, "invalid predicate `{}`", p);
599 ast::MetaItemKind::Word | ast::MetaItemKind::NameValue(..) => {
600 if let (Some(feats), Some(gated_cfg)) = (features, GatedCfg::gate(cfg)) {
601 gated_cfg.check_and_emit(sess, feats);
603 sess.config.contains(&(cfg.name(), cfg.value_str()))
608 /// Represents the #[stable], #[unstable] and #[rustc_deprecated] attributes.
609 #[derive(RustcEncodable, RustcDecodable, Clone, Debug, PartialEq, Eq, Hash)]
610 pub struct Stability {
611 pub level: StabilityLevel,
613 pub rustc_depr: Option<RustcDeprecation>,
616 /// The available stability levels.
617 #[derive(RustcEncodable, RustcDecodable, PartialEq, PartialOrd, Clone, Debug, Eq, Hash)]
618 pub enum StabilityLevel {
619 // Reason for the current stability level and the relevant rust-lang issue
620 Unstable { reason: Option<Symbol>, issue: u32 },
621 Stable { since: Symbol },
624 #[derive(RustcEncodable, RustcDecodable, PartialEq, PartialOrd, Clone, Debug, Eq, Hash)]
625 pub struct RustcDeprecation {
630 #[derive(RustcEncodable, RustcDecodable, PartialEq, PartialOrd, Clone, Debug, Eq, Hash)]
631 pub struct Deprecation {
632 pub since: Option<Symbol>,
633 pub note: Option<Symbol>,
636 impl StabilityLevel {
637 pub fn is_unstable(&self) -> bool { if let Unstable {..} = *self { true } else { false }}
638 pub fn is_stable(&self) -> bool { if let Stable {..} = *self { true } else { false }}
641 fn find_stability_generic<'a, I>(diagnostic: &Handler,
645 where I: Iterator<Item = &'a Attribute>
647 let mut stab: Option<Stability> = None;
648 let mut rustc_depr: Option<RustcDeprecation> = None;
650 'outer: for attr in attrs_iter {
651 if attr.path != "rustc_deprecated" && attr.path != "unstable" && attr.path != "stable" {
652 continue // not a stability level
657 let meta = attr.meta();
658 if let Some(MetaItem { node: MetaItemKind::List(ref metas), .. }) = meta {
659 let meta = meta.as_ref().unwrap();
660 let get = |meta: &MetaItem, item: &mut Option<Symbol>| {
662 handle_errors(diagnostic, meta.span, AttrError::MultipleItem(meta.name()));
665 if let Some(v) = meta.value_str() {
669 span_err!(diagnostic, meta.span, E0539, "incorrect meta item");
674 match &*meta.name.as_str() {
675 "rustc_deprecated" => {
676 if rustc_depr.is_some() {
677 span_err!(diagnostic, item_sp, E0540,
678 "multiple rustc_deprecated attributes");
682 let mut since = None;
683 let mut reason = None;
685 if let Some(mi) = meta.meta_item() {
686 match &*mi.name().as_str() {
687 "since" => if !get(mi, &mut since) { continue 'outer },
688 "reason" => if !get(mi, &mut reason) { continue 'outer },
690 handle_errors(diagnostic, mi.span,
691 AttrError::UnknownMetaItem(mi.name()));
696 handle_errors(diagnostic, meta.span, AttrError::UnsupportedLiteral);
701 match (since, reason) {
702 (Some(since), Some(reason)) => {
703 rustc_depr = Some(RustcDeprecation {
709 handle_errors(diagnostic, attr.span(), AttrError::MissingSince);
713 span_err!(diagnostic, attr.span(), E0543, "missing 'reason'");
720 handle_errors(diagnostic, attr.span(), AttrError::MultipleStabilityLevels);
724 let mut feature = None;
725 let mut reason = None;
726 let mut issue = None;
728 if let Some(mi) = meta.meta_item() {
729 match &*mi.name().as_str() {
730 "feature" => if !get(mi, &mut feature) { continue 'outer },
731 "reason" => if !get(mi, &mut reason) { continue 'outer },
732 "issue" => if !get(mi, &mut issue) { continue 'outer },
734 handle_errors(diagnostic, meta.span,
735 AttrError::UnknownMetaItem(mi.name()));
740 handle_errors(diagnostic, meta.span, AttrError::UnsupportedLiteral);
745 match (feature, reason, issue) {
746 (Some(feature), reason, Some(issue)) => {
747 stab = Some(Stability {
751 if let Ok(issue) = issue.as_str().parse() {
754 span_err!(diagnostic, attr.span(), E0545,
755 "incorrect 'issue'");
765 handle_errors(diagnostic, attr.span(), AttrError::MissingFeature);
769 span_err!(diagnostic, attr.span(), E0547, "missing 'issue'");
776 handle_errors(diagnostic, attr.span(), AttrError::MultipleStabilityLevels);
780 let mut feature = None;
781 let mut since = None;
783 if let NestedMetaItemKind::MetaItem(ref mi) = meta.node {
784 match &*mi.name().as_str() {
785 "feature" => if !get(mi, &mut feature) { continue 'outer },
786 "since" => if !get(mi, &mut since) { continue 'outer },
788 handle_errors(diagnostic, meta.span,
789 AttrError::UnknownMetaItem(mi.name()));
794 handle_errors(diagnostic, meta.span, AttrError::UnsupportedLiteral);
799 match (feature, since) {
800 (Some(feature), Some(since)) => {
801 stab = Some(Stability {
810 handle_errors(diagnostic, attr.span(), AttrError::MissingFeature);
814 handle_errors(diagnostic, attr.span(), AttrError::MissingSince);
822 span_err!(diagnostic, attr.span(), E0548, "incorrect stability attribute type");
827 // Merge the deprecation info into the stability info
828 if let Some(rustc_depr) = rustc_depr {
829 if let Some(ref mut stab) = stab {
830 stab.rustc_depr = Some(rustc_depr);
832 span_err!(diagnostic, item_sp, E0549,
833 "rustc_deprecated attribute must be paired with \
834 either stable or unstable attribute");
841 fn find_deprecation_generic<'a, I>(diagnostic: &Handler,
844 -> Option<Deprecation>
845 where I: Iterator<Item = &'a Attribute>
847 let mut depr: Option<Deprecation> = None;
849 'outer: for attr in attrs_iter {
850 if attr.path != "deprecated" {
857 span_err!(diagnostic, item_sp, E0550, "multiple deprecated attributes");
861 depr = if let Some(metas) = attr.meta_item_list() {
862 let get = |meta: &MetaItem, item: &mut Option<Symbol>| {
864 handle_errors(diagnostic, meta.span, AttrError::MultipleItem(meta.name()));
867 if let Some(v) = meta.value_str() {
871 span_err!(diagnostic, meta.span, E0551, "incorrect meta item");
876 let mut since = None;
879 if let NestedMetaItemKind::MetaItem(ref mi) = meta.node {
880 match &*mi.name().as_str() {
881 "since" => if !get(mi, &mut since) { continue 'outer },
882 "note" => if !get(mi, &mut note) { continue 'outer },
884 handle_errors(diagnostic, meta.span,
885 AttrError::UnknownMetaItem(mi.name()));
890 handle_errors(diagnostic, meta.span, AttrError::UnsupportedLiteral);
895 Some(Deprecation {since: since, note: note})
897 Some(Deprecation{since: None, note: None})
904 /// Find the first stability attribute. `None` if none exists.
905 pub fn find_stability(diagnostic: &Handler, attrs: &[Attribute],
906 item_sp: Span) -> Option<Stability> {
907 find_stability_generic(diagnostic, attrs.iter(), item_sp)
910 /// Find the deprecation attribute. `None` if none exists.
911 pub fn find_deprecation(diagnostic: &Handler, attrs: &[Attribute],
912 item_sp: Span) -> Option<Deprecation> {
913 find_deprecation_generic(diagnostic, attrs.iter(), item_sp)
917 /// Parse #[repr(...)] forms.
919 /// Valid repr contents: any of the primitive integral type names (see
920 /// `int_type_of_word`, below) to specify enum discriminant type; `C`, to use
921 /// the same discriminant size that the corresponding C enum would or C
922 /// structure layout, and `packed` to remove padding.
923 pub fn find_repr_attrs(diagnostic: &Handler, attr: &Attribute) -> Vec<ReprAttr> {
924 let mut acc = Vec::new();
925 if attr.path == "repr" {
926 if let Some(items) = attr.meta_item_list() {
929 if !item.is_meta_item() {
930 handle_errors(diagnostic, item.span, AttrError::UnsupportedLiteral);
934 if let Some(mi) = item.word() {
935 let word = &*mi.name().as_str();
936 let hint = match word {
937 // Can't use "extern" because it's not a lexical identifier.
938 "C" => Some(ReprExtern),
939 "packed" => Some(ReprPacked),
940 "simd" => Some(ReprSimd),
941 _ => match int_type_of_word(word) {
942 Some(ity) => Some(ReprInt(ity)),
944 // Not a word we recognize
945 span_err!(diagnostic, item.span, E0552,
946 "unrecognized representation hint");
952 if let Some(h) = hint {
956 span_err!(diagnostic, item.span, E0553,
957 "unrecognized enum representation hint");
965 fn int_type_of_word(s: &str) -> Option<IntType> {
967 "i8" => Some(SignedInt(ast::IntTy::I8)),
968 "u8" => Some(UnsignedInt(ast::UintTy::U8)),
969 "i16" => Some(SignedInt(ast::IntTy::I16)),
970 "u16" => Some(UnsignedInt(ast::UintTy::U16)),
971 "i32" => Some(SignedInt(ast::IntTy::I32)),
972 "u32" => Some(UnsignedInt(ast::UintTy::U32)),
973 "i64" => Some(SignedInt(ast::IntTy::I64)),
974 "u64" => Some(UnsignedInt(ast::UintTy::U64)),
975 "i128" => Some(SignedInt(ast::IntTy::I128)),
976 "u128" => Some(UnsignedInt(ast::UintTy::U128)),
977 "isize" => Some(SignedInt(ast::IntTy::Is)),
978 "usize" => Some(UnsignedInt(ast::UintTy::Us)),
983 #[derive(PartialEq, Debug, RustcEncodable, RustcDecodable, Copy, Clone)]
991 #[derive(Eq, Hash, PartialEq, Debug, RustcEncodable, RustcDecodable, Copy, Clone)]
993 SignedInt(ast::IntTy),
994 UnsignedInt(ast::UintTy)
999 pub fn is_signed(self) -> bool {
1001 SignedInt(..) => true,
1002 UnsignedInt(..) => false
1008 fn tokens(&self) -> TokenStream {
1009 let ident = TokenTree::Token(self.span, Token::Ident(Ident::with_empty_ctxt(self.name)));
1010 TokenStream::concat(vec![ident.into(), self.node.tokens(self.span)])
1013 fn from_tokens<I>(tokens: &mut iter::Peekable<I>) -> Option<MetaItem>
1014 where I: Iterator<Item = TokenTree>,
1016 let (mut span, name) = match tokens.next() {
1017 Some(TokenTree::Token(span, Token::Ident(ident))) => (span, ident.name),
1018 Some(TokenTree::Token(_, Token::Interpolated(ref nt))) => match **nt {
1019 token::Nonterminal::NtIdent(ident) => (ident.span, ident.node.name),
1020 token::Nonterminal::NtMeta(ref meta) => return Some(meta.clone()),
1025 let node = match MetaItemKind::from_tokens(tokens) {
1029 if let Some(last_span) = node.last_span() {
1030 span.hi = last_span.hi;
1032 Some(MetaItem { name: name, span: span, node: node })
1037 fn last_span(&self) -> Option<Span> {
1039 MetaItemKind::Word => None,
1040 MetaItemKind::List(ref list) => list.last().map(NestedMetaItem::span),
1041 MetaItemKind::NameValue(ref lit) => Some(lit.span),
1045 pub fn tokens(&self, span: Span) -> TokenStream {
1047 MetaItemKind::Word => TokenStream::empty(),
1048 MetaItemKind::NameValue(ref lit) => {
1049 TokenStream::concat(vec![TokenTree::Token(span, Token::Eq).into(), lit.tokens()])
1051 MetaItemKind::List(ref list) => {
1052 let mut tokens = Vec::new();
1053 for (i, item) in list.iter().enumerate() {
1055 tokens.push(TokenTree::Token(span, Token::Comma).into());
1057 tokens.push(item.node.tokens());
1059 TokenTree::Delimited(span, Delimited {
1060 delim: token::Paren,
1061 tts: TokenStream::concat(tokens).into(),
1067 fn from_tokens<I>(tokens: &mut iter::Peekable<I>) -> Option<MetaItemKind>
1068 where I: Iterator<Item = TokenTree>,
1070 let delimited = match tokens.peek().cloned() {
1071 Some(TokenTree::Token(_, token::Eq)) => {
1073 return if let Some(TokenTree::Token(span, token)) = tokens.next() {
1074 LitKind::from_token(token)
1075 .map(|lit| MetaItemKind::NameValue(Spanned { node: lit, span: span }))
1080 Some(TokenTree::Delimited(_, ref delimited)) if delimited.delim == token::Paren => {
1084 _ => return Some(MetaItemKind::Word),
1087 let mut tokens = delimited.into_trees().peekable();
1088 let mut result = Vec::new();
1089 while let Some(..) = tokens.peek() {
1090 match NestedMetaItemKind::from_tokens(&mut tokens) {
1091 Some(item) => result.push(Spanned { span: item.span(), node: item }),
1092 None => return None,
1094 match tokens.next() {
1095 None | Some(TokenTree::Token(_, Token::Comma)) => {}
1099 Some(MetaItemKind::List(result))
1103 impl NestedMetaItemKind {
1104 fn span(&self) -> Span {
1106 NestedMetaItemKind::MetaItem(ref item) => item.span,
1107 NestedMetaItemKind::Literal(ref lit) => lit.span,
1111 fn tokens(&self) -> TokenStream {
1113 NestedMetaItemKind::MetaItem(ref item) => item.tokens(),
1114 NestedMetaItemKind::Literal(ref lit) => lit.tokens(),
1118 fn from_tokens<I>(tokens: &mut iter::Peekable<I>) -> Option<NestedMetaItemKind>
1119 where I: Iterator<Item = TokenTree>,
1121 if let Some(TokenTree::Token(span, token)) = tokens.peek().cloned() {
1122 if let Some(node) = LitKind::from_token(token) {
1124 return Some(NestedMetaItemKind::Literal(Spanned { node: node, span: span }));
1128 MetaItem::from_tokens(tokens).map(NestedMetaItemKind::MetaItem)
1133 fn tokens(&self) -> TokenStream {
1134 TokenTree::Token(self.span, self.node.token()).into()
1139 fn token(&self) -> Token {
1143 LitKind::Str(string, ast::StrStyle::Cooked) => {
1144 let mut escaped = String::new();
1145 for ch in string.as_str().chars() {
1146 escaped.extend(ch.escape_unicode());
1148 Token::Literal(token::Lit::Str_(Symbol::intern(&escaped)), None)
1150 LitKind::Str(string, ast::StrStyle::Raw(n)) => {
1151 Token::Literal(token::Lit::StrRaw(string, n), None)
1153 LitKind::ByteStr(ref bytes) => {
1154 let string = bytes.iter().cloned().flat_map(ascii::escape_default)
1155 .map(Into::<char>::into).collect::<String>();
1156 Token::Literal(token::Lit::ByteStr(Symbol::intern(&string)), None)
1158 LitKind::Byte(byte) => {
1159 let string: String = ascii::escape_default(byte).map(Into::<char>::into).collect();
1160 Token::Literal(token::Lit::Byte(Symbol::intern(&string)), None)
1162 LitKind::Char(ch) => {
1163 let string: String = ch.escape_default().map(Into::<char>::into).collect();
1164 Token::Literal(token::Lit::Char(Symbol::intern(&string)), None)
1166 LitKind::Int(n, ty) => {
1167 let suffix = match ty {
1168 ast::LitIntType::Unsigned(ty) => Some(Symbol::intern(ty.ty_to_string())),
1169 ast::LitIntType::Signed(ty) => Some(Symbol::intern(ty.ty_to_string())),
1170 ast::LitIntType::Unsuffixed => None,
1172 Token::Literal(token::Lit::Integer(Symbol::intern(&n.to_string())), suffix)
1174 LitKind::Float(symbol, ty) => {
1175 Token::Literal(token::Lit::Float(symbol), Some(Symbol::intern(ty.ty_to_string())))
1177 LitKind::FloatUnsuffixed(symbol) => Token::Literal(token::Lit::Float(symbol), None),
1178 LitKind::Bool(value) => Token::Ident(Ident::with_empty_ctxt(Symbol::intern(match value {
1185 fn from_token(token: Token) -> Option<LitKind> {
1187 Token::Ident(ident) if ident.name == "true" => Some(LitKind::Bool(true)),
1188 Token::Ident(ident) if ident.name == "false" => Some(LitKind::Bool(false)),
1189 Token::Interpolated(ref nt) => match **nt {
1190 token::NtExpr(ref v) => match v.node {
1191 ExprKind::Lit(ref lit) => Some(lit.node.clone()),
1196 Token::Literal(lit, suf) => {
1197 let (suffix_illegal, result) = parse::lit_token(lit, suf, None);
1198 if suffix_illegal && suf.is_some() {
1208 pub trait HasAttrs: Sized {
1209 fn attrs(&self) -> &[ast::Attribute];
1210 fn map_attrs<F: FnOnce(Vec<ast::Attribute>) -> Vec<ast::Attribute>>(self, f: F) -> Self;
1213 impl<T: HasAttrs> HasAttrs for Spanned<T> {
1214 fn attrs(&self) -> &[ast::Attribute] { self.node.attrs() }
1215 fn map_attrs<F: FnOnce(Vec<ast::Attribute>) -> Vec<ast::Attribute>>(self, f: F) -> Self {
1216 Spanned { node: self.node.map_attrs(f), span: self.span }
1220 impl HasAttrs for Vec<Attribute> {
1221 fn attrs(&self) -> &[Attribute] {
1224 fn map_attrs<F: FnOnce(Vec<Attribute>) -> Vec<Attribute>>(self, f: F) -> Self {
1229 impl HasAttrs for ThinVec<Attribute> {
1230 fn attrs(&self) -> &[Attribute] {
1233 fn map_attrs<F: FnOnce(Vec<Attribute>) -> Vec<Attribute>>(self, f: F) -> Self {
1234 f(self.into()).into()
1238 impl<T: HasAttrs + 'static> HasAttrs for P<T> {
1239 fn attrs(&self) -> &[Attribute] {
1242 fn map_attrs<F: FnOnce(Vec<Attribute>) -> Vec<Attribute>>(self, f: F) -> Self {
1243 self.map(|t| t.map_attrs(f))
1247 impl HasAttrs for StmtKind {
1248 fn attrs(&self) -> &[Attribute] {
1250 StmtKind::Local(ref local) => local.attrs(),
1251 StmtKind::Item(..) => &[],
1252 StmtKind::Expr(ref expr) | StmtKind::Semi(ref expr) => expr.attrs(),
1253 StmtKind::Mac(ref mac) => {
1254 let (_, _, ref attrs) = **mac;
1260 fn map_attrs<F: FnOnce(Vec<Attribute>) -> Vec<Attribute>>(self, f: F) -> Self {
1262 StmtKind::Local(local) => StmtKind::Local(local.map_attrs(f)),
1263 StmtKind::Item(..) => self,
1264 StmtKind::Expr(expr) => StmtKind::Expr(expr.map_attrs(f)),
1265 StmtKind::Semi(expr) => StmtKind::Semi(expr.map_attrs(f)),
1266 StmtKind::Mac(mac) => StmtKind::Mac(mac.map(|(mac, style, attrs)| {
1267 (mac, style, attrs.map_attrs(f))
1273 impl HasAttrs for Stmt {
1274 fn attrs(&self) -> &[ast::Attribute] { self.node.attrs() }
1275 fn map_attrs<F: FnOnce(Vec<ast::Attribute>) -> Vec<ast::Attribute>>(self, f: F) -> Self {
1276 Stmt { id: self.id, node: self.node.map_attrs(f), span: self.span }
1280 macro_rules! derive_has_attrs {
1281 ($($ty:path),*) => { $(
1282 impl HasAttrs for $ty {
1283 fn attrs(&self) -> &[Attribute] {
1287 fn map_attrs<F>(mut self, f: F) -> Self
1288 where F: FnOnce(Vec<Attribute>) -> Vec<Attribute>,
1290 self.attrs = self.attrs.map_attrs(f);
1298 Item, Expr, Local, ast::ForeignItem, ast::StructField, ast::ImplItem, ast::TraitItem, ast::Arm,
1299 ast::Field, ast::FieldPat, ast::Variant_