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 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).clone()),
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);
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 if self.style == ast::AttrStyle::Outer {
375 f(&mk_attr_outer(self.span, self.id, meta))
377 f(&mk_attr_inner(self.span, self.id, meta))
387 pub fn mk_name_value_item_str(name: Name, value: Symbol) -> MetaItem {
388 let value_lit = dummy_spanned(LitKind::Str(value, ast::StrStyle::Cooked));
389 mk_spanned_name_value_item(DUMMY_SP, name, value_lit)
392 pub fn mk_name_value_item(name: Name, value: ast::Lit) -> MetaItem {
393 mk_spanned_name_value_item(DUMMY_SP, name, value)
396 pub fn mk_list_item(name: Name, items: Vec<NestedMetaItem>) -> MetaItem {
397 mk_spanned_list_item(DUMMY_SP, name, items)
400 pub fn mk_list_word_item(name: Name) -> ast::NestedMetaItem {
401 dummy_spanned(NestedMetaItemKind::MetaItem(mk_spanned_word_item(DUMMY_SP, name)))
404 pub fn mk_word_item(name: Name) -> MetaItem {
405 mk_spanned_word_item(DUMMY_SP, name)
408 pub fn mk_spanned_name_value_item(sp: Span, name: Name, value: ast::Lit) -> MetaItem {
409 MetaItem { span: sp, name: name, node: MetaItemKind::NameValue(value) }
412 pub fn mk_spanned_list_item(sp: Span, name: Name, items: Vec<NestedMetaItem>) -> MetaItem {
413 MetaItem { span: sp, name: name, node: MetaItemKind::List(items) }
416 pub fn mk_spanned_word_item(sp: Span, name: Name) -> MetaItem {
417 MetaItem { span: sp, name: name, node: MetaItemKind::Word }
422 thread_local! { static NEXT_ATTR_ID: Cell<usize> = Cell::new(0) }
424 pub fn mk_attr_id() -> AttrId {
425 let id = NEXT_ATTR_ID.with(|slot| {
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 innter 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 first_attr_value_str_by_name(attrs: &[Attribute], name: &str) -> Option<Symbol> {
495 .find(|at| at.check_name(name))
496 .and_then(|at| at.value_str())
499 /* Higher-level applications */
501 pub fn find_crate_name(attrs: &[Attribute]) -> Option<Symbol> {
502 first_attr_value_str_by_name(attrs, "crate_name")
505 /// Find the value of #[export_name=*] attribute and check its validity.
506 pub fn find_export_name_attr(diag: &Handler, attrs: &[Attribute]) -> Option<Symbol> {
507 attrs.iter().fold(None, |ia,attr| {
508 if attr.check_name("export_name") {
509 if let s@Some(_) = attr.value_str() {
512 struct_span_err!(diag, attr.span, E0558,
513 "export_name attribute has invalid format")
514 .span_label(attr.span, "did you mean #[export_name=\"*\"]?")
524 pub fn contains_extern_indicator(diag: &Handler, attrs: &[Attribute]) -> bool {
525 contains_name(attrs, "no_mangle") ||
526 find_export_name_attr(diag, attrs).is_some()
529 #[derive(Copy, Clone, PartialEq)]
530 pub enum InlineAttr {
537 /// Determine what `#[inline]` attribute is present in `attrs`, if any.
538 pub fn find_inline_attr(diagnostic: Option<&Handler>, attrs: &[Attribute]) -> InlineAttr {
539 attrs.iter().fold(InlineAttr::None, |ia, attr| {
540 if attr.path != "inline" {
543 let meta = match attr.meta() {
544 Some(meta) => meta.node,
548 MetaItemKind::Word => {
552 MetaItemKind::List(ref items) => {
554 if items.len() != 1 {
555 diagnostic.map(|d|{ span_err!(d, attr.span, E0534, "expected one argument"); });
557 } else if list_contains_name(&items[..], "always") {
559 } else if list_contains_name(&items[..], "never") {
563 span_err!(d, items[0].span, E0535, "invalid argument");
574 /// True if `#[inline]` or `#[inline(always)]` is present in `attrs`.
575 pub fn requests_inline(attrs: &[Attribute]) -> bool {
576 match find_inline_attr(None, attrs) {
577 InlineAttr::Hint | InlineAttr::Always => true,
578 InlineAttr::None | InlineAttr::Never => false,
582 /// Tests if a cfg-pattern matches the cfg set
583 pub fn cfg_matches(cfg: &ast::MetaItem, sess: &ParseSess, features: Option<&Features>) -> bool {
585 ast::MetaItemKind::List(ref mis) => {
586 for mi in mis.iter() {
587 if !mi.is_meta_item() {
588 handle_errors(&sess.span_diagnostic, mi.span, AttrError::UnsupportedLiteral);
593 // The unwraps below may look dangerous, but we've already asserted
594 // that they won't fail with the loop above.
595 match &*cfg.name.as_str() {
596 "any" => mis.iter().any(|mi| {
597 cfg_matches(mi.meta_item().unwrap(), sess, features)
599 "all" => mis.iter().all(|mi| {
600 cfg_matches(mi.meta_item().unwrap(), sess, features)
604 span_err!(sess.span_diagnostic, cfg.span, E0536, "expected 1 cfg-pattern");
608 !cfg_matches(mis[0].meta_item().unwrap(), sess, features)
611 span_err!(sess.span_diagnostic, cfg.span, E0537, "invalid predicate `{}`", p);
616 ast::MetaItemKind::Word | ast::MetaItemKind::NameValue(..) => {
617 if let (Some(feats), Some(gated_cfg)) = (features, GatedCfg::gate(cfg)) {
618 gated_cfg.check_and_emit(sess, feats);
620 sess.config.contains(&(cfg.name(), cfg.value_str()))
625 /// Represents the #[stable], #[unstable] and #[rustc_deprecated] attributes.
626 #[derive(RustcEncodable, RustcDecodable, Clone, Debug, PartialEq, Eq, Hash)]
627 pub struct Stability {
628 pub level: StabilityLevel,
630 pub rustc_depr: Option<RustcDeprecation>,
633 /// The available stability levels.
634 #[derive(RustcEncodable, RustcDecodable, PartialEq, PartialOrd, Clone, Debug, Eq, Hash)]
635 pub enum StabilityLevel {
636 // Reason for the current stability level and the relevant rust-lang issue
637 Unstable { reason: Option<Symbol>, issue: u32 },
638 Stable { since: Symbol },
641 #[derive(RustcEncodable, RustcDecodable, PartialEq, PartialOrd, Clone, Debug, Eq, Hash)]
642 pub struct RustcDeprecation {
647 #[derive(RustcEncodable, RustcDecodable, PartialEq, PartialOrd, Clone, Debug, Eq, Hash)]
648 pub struct Deprecation {
649 pub since: Option<Symbol>,
650 pub note: Option<Symbol>,
653 impl StabilityLevel {
654 pub fn is_unstable(&self) -> bool { if let Unstable {..} = *self { true } else { false }}
655 pub fn is_stable(&self) -> bool { if let Stable {..} = *self { true } else { false }}
658 fn find_stability_generic<'a, I>(diagnostic: &Handler,
662 where I: Iterator<Item = &'a Attribute>
664 let mut stab: Option<Stability> = None;
665 let mut rustc_depr: Option<RustcDeprecation> = None;
667 'outer: for attr in attrs_iter {
668 if attr.path != "rustc_deprecated" && attr.path != "unstable" && attr.path != "stable" {
669 continue // not a stability level
674 let meta = attr.meta();
675 if let Some(MetaItem { node: MetaItemKind::List(ref metas), .. }) = meta {
676 let meta = meta.as_ref().unwrap();
677 let get = |meta: &MetaItem, item: &mut Option<Symbol>| {
679 handle_errors(diagnostic, meta.span, AttrError::MultipleItem(meta.name()));
682 if let Some(v) = meta.value_str() {
686 span_err!(diagnostic, meta.span, E0539, "incorrect meta item");
691 match &*meta.name.as_str() {
692 "rustc_deprecated" => {
693 if rustc_depr.is_some() {
694 span_err!(diagnostic, item_sp, E0540,
695 "multiple rustc_deprecated attributes");
699 let mut since = None;
700 let mut reason = None;
702 if let Some(mi) = meta.meta_item() {
703 match &*mi.name().as_str() {
704 "since" => if !get(mi, &mut since) { continue 'outer },
705 "reason" => if !get(mi, &mut reason) { continue 'outer },
707 handle_errors(diagnostic, mi.span,
708 AttrError::UnknownMetaItem(mi.name()));
713 handle_errors(diagnostic, meta.span, AttrError::UnsupportedLiteral);
718 match (since, reason) {
719 (Some(since), Some(reason)) => {
720 rustc_depr = Some(RustcDeprecation {
726 handle_errors(diagnostic, attr.span(), AttrError::MissingSince);
730 span_err!(diagnostic, attr.span(), E0543, "missing 'reason'");
737 handle_errors(diagnostic, attr.span(), AttrError::MultipleStabilityLevels);
741 let mut feature = None;
742 let mut reason = None;
743 let mut issue = None;
745 if let Some(mi) = meta.meta_item() {
746 match &*mi.name().as_str() {
747 "feature" => if !get(mi, &mut feature) { continue 'outer },
748 "reason" => if !get(mi, &mut reason) { continue 'outer },
749 "issue" => if !get(mi, &mut issue) { continue 'outer },
751 handle_errors(diagnostic, meta.span,
752 AttrError::UnknownMetaItem(mi.name()));
757 handle_errors(diagnostic, meta.span, AttrError::UnsupportedLiteral);
762 match (feature, reason, issue) {
763 (Some(feature), reason, Some(issue)) => {
764 stab = Some(Stability {
768 if let Ok(issue) = issue.as_str().parse() {
771 span_err!(diagnostic, attr.span(), E0545,
772 "incorrect 'issue'");
782 handle_errors(diagnostic, attr.span(), AttrError::MissingFeature);
786 span_err!(diagnostic, attr.span(), E0547, "missing 'issue'");
793 handle_errors(diagnostic, attr.span(), AttrError::MultipleStabilityLevels);
797 let mut feature = None;
798 let mut since = None;
800 if let NestedMetaItemKind::MetaItem(ref mi) = meta.node {
801 match &*mi.name().as_str() {
802 "feature" => if !get(mi, &mut feature) { continue 'outer },
803 "since" => if !get(mi, &mut since) { continue 'outer },
805 handle_errors(diagnostic, meta.span,
806 AttrError::UnknownMetaItem(mi.name()));
811 handle_errors(diagnostic, meta.span, AttrError::UnsupportedLiteral);
816 match (feature, since) {
817 (Some(feature), Some(since)) => {
818 stab = Some(Stability {
827 handle_errors(diagnostic, attr.span(), AttrError::MissingFeature);
831 handle_errors(diagnostic, attr.span(), AttrError::MissingSince);
839 span_err!(diagnostic, attr.span(), E0548, "incorrect stability attribute type");
844 // Merge the deprecation info into the stability info
845 if let Some(rustc_depr) = rustc_depr {
846 if let Some(ref mut stab) = stab {
847 stab.rustc_depr = Some(rustc_depr);
849 span_err!(diagnostic, item_sp, E0549,
850 "rustc_deprecated attribute must be paired with \
851 either stable or unstable attribute");
858 fn find_deprecation_generic<'a, I>(diagnostic: &Handler,
861 -> Option<Deprecation>
862 where I: Iterator<Item = &'a Attribute>
864 let mut depr: Option<Deprecation> = None;
866 'outer: for attr in attrs_iter {
867 if attr.path != "deprecated" {
874 span_err!(diagnostic, item_sp, E0550, "multiple deprecated attributes");
878 depr = if let Some(metas) = attr.meta_item_list() {
879 let get = |meta: &MetaItem, item: &mut Option<Symbol>| {
881 handle_errors(diagnostic, meta.span, AttrError::MultipleItem(meta.name()));
884 if let Some(v) = meta.value_str() {
888 span_err!(diagnostic, meta.span, E0551, "incorrect meta item");
893 let mut since = None;
896 if let NestedMetaItemKind::MetaItem(ref mi) = meta.node {
897 match &*mi.name().as_str() {
898 "since" => if !get(mi, &mut since) { continue 'outer },
899 "note" => if !get(mi, &mut note) { continue 'outer },
901 handle_errors(diagnostic, meta.span,
902 AttrError::UnknownMetaItem(mi.name()));
907 handle_errors(diagnostic, meta.span, AttrError::UnsupportedLiteral);
912 Some(Deprecation {since: since, note: note})
914 Some(Deprecation{since: None, note: None})
921 /// Find the first stability attribute. `None` if none exists.
922 pub fn find_stability(diagnostic: &Handler, attrs: &[Attribute],
923 item_sp: Span) -> Option<Stability> {
924 find_stability_generic(diagnostic, attrs.iter(), item_sp)
927 /// Find the deprecation attribute. `None` if none exists.
928 pub fn find_deprecation(diagnostic: &Handler, attrs: &[Attribute],
929 item_sp: Span) -> Option<Deprecation> {
930 find_deprecation_generic(diagnostic, attrs.iter(), item_sp)
934 /// Parse #[repr(...)] forms.
936 /// Valid repr contents: any of the primitive integral type names (see
937 /// `int_type_of_word`, below) to specify enum discriminant type; `C`, to use
938 /// the same discriminant size that the corresponding C enum would or C
939 /// structure layout, and `packed` to remove padding.
940 pub fn find_repr_attrs(diagnostic: &Handler, attr: &Attribute) -> Vec<ReprAttr> {
941 let mut acc = Vec::new();
942 if attr.path == "repr" {
943 if let Some(items) = attr.meta_item_list() {
946 if !item.is_meta_item() {
947 handle_errors(diagnostic, item.span, AttrError::UnsupportedLiteral);
951 let mut recognised = false;
952 if let Some(mi) = item.word() {
953 let word = &*mi.name().as_str();
954 let hint = match word {
955 // Can't use "extern" because it's not a lexical identifier.
956 "C" => Some(ReprExtern),
957 "packed" => Some(ReprPacked),
958 "simd" => Some(ReprSimd),
959 _ => match int_type_of_word(word) {
960 Some(ity) => Some(ReprInt(ity)),
967 if let Some(h) = hint {
971 } else if let Some((name, value)) = item.name_value_literal() {
974 let mut align_error = None;
975 if let ast::LitKind::Int(align, ast::LitIntType::Unsuffixed) = value.node {
976 if align.is_power_of_two() {
977 // rustc::ty::layout::Align restricts align to <= 32768
979 acc.push(ReprAlign(align as u16));
981 align_error = Some("larger than 32768");
984 align_error = Some("not a power of two");
987 align_error = Some("not an unsuffixed integer");
989 if let Some(align_error) = align_error {
990 span_err!(diagnostic, item.span, E0589,
991 "invalid `repr(align)` attribute: {}", align_error);
996 // Not a word we recognize
997 span_err!(diagnostic, item.span, E0552,
998 "unrecognized representation hint");
1006 fn int_type_of_word(s: &str) -> Option<IntType> {
1008 "i8" => Some(SignedInt(ast::IntTy::I8)),
1009 "u8" => Some(UnsignedInt(ast::UintTy::U8)),
1010 "i16" => Some(SignedInt(ast::IntTy::I16)),
1011 "u16" => Some(UnsignedInt(ast::UintTy::U16)),
1012 "i32" => Some(SignedInt(ast::IntTy::I32)),
1013 "u32" => Some(UnsignedInt(ast::UintTy::U32)),
1014 "i64" => Some(SignedInt(ast::IntTy::I64)),
1015 "u64" => Some(UnsignedInt(ast::UintTy::U64)),
1016 "i128" => Some(SignedInt(ast::IntTy::I128)),
1017 "u128" => Some(UnsignedInt(ast::UintTy::U128)),
1018 "isize" => Some(SignedInt(ast::IntTy::Is)),
1019 "usize" => Some(UnsignedInt(ast::UintTy::Us)),
1024 #[derive(PartialEq, Debug, RustcEncodable, RustcDecodable, Copy, Clone)]
1033 #[derive(Eq, Hash, PartialEq, Debug, RustcEncodable, RustcDecodable, Copy, Clone)]
1035 SignedInt(ast::IntTy),
1036 UnsignedInt(ast::UintTy)
1041 pub fn is_signed(self) -> bool {
1043 SignedInt(..) => true,
1044 UnsignedInt(..) => false
1050 fn tokens(&self) -> TokenStream {
1051 let ident = TokenTree::Token(self.span, Token::Ident(Ident::with_empty_ctxt(self.name)));
1052 TokenStream::concat(vec![ident.into(), self.node.tokens(self.span)])
1055 fn from_tokens<I>(tokens: &mut iter::Peekable<I>) -> Option<MetaItem>
1056 where I: Iterator<Item = TokenTree>,
1058 let (mut span, name) = match tokens.next() {
1059 Some(TokenTree::Token(span, Token::Ident(ident))) => (span, ident.name),
1060 Some(TokenTree::Token(_, Token::Interpolated(ref nt))) => match **nt {
1061 token::Nonterminal::NtIdent(ident) => (ident.span, ident.node.name),
1062 token::Nonterminal::NtMeta(ref meta) => return Some(meta.clone()),
1067 let node = match MetaItemKind::from_tokens(tokens) {
1071 if let Some(last_span) = node.last_span() {
1072 span.hi = last_span.hi;
1074 Some(MetaItem { name: name, span: span, node: node })
1079 fn last_span(&self) -> Option<Span> {
1081 MetaItemKind::Word => None,
1082 MetaItemKind::List(ref list) => list.last().map(NestedMetaItem::span),
1083 MetaItemKind::NameValue(ref lit) => Some(lit.span),
1087 pub fn tokens(&self, span: Span) -> TokenStream {
1089 MetaItemKind::Word => TokenStream::empty(),
1090 MetaItemKind::NameValue(ref lit) => {
1091 TokenStream::concat(vec![TokenTree::Token(span, Token::Eq).into(), lit.tokens()])
1093 MetaItemKind::List(ref list) => {
1094 let mut tokens = Vec::new();
1095 for (i, item) in list.iter().enumerate() {
1097 tokens.push(TokenTree::Token(span, Token::Comma).into());
1099 tokens.push(item.node.tokens());
1101 TokenTree::Delimited(span, Delimited {
1102 delim: token::Paren,
1103 tts: TokenStream::concat(tokens).into(),
1109 fn from_tokens<I>(tokens: &mut iter::Peekable<I>) -> Option<MetaItemKind>
1110 where I: Iterator<Item = TokenTree>,
1112 let delimited = match tokens.peek().cloned() {
1113 Some(TokenTree::Token(_, token::Eq)) => {
1115 return if let Some(TokenTree::Token(span, token)) = tokens.next() {
1116 LitKind::from_token(token)
1117 .map(|lit| MetaItemKind::NameValue(Spanned { node: lit, span: span }))
1122 Some(TokenTree::Delimited(_, ref delimited)) if delimited.delim == token::Paren => {
1126 _ => return Some(MetaItemKind::Word),
1129 let mut tokens = delimited.into_trees().peekable();
1130 let mut result = Vec::new();
1131 while let Some(..) = tokens.peek() {
1132 match NestedMetaItemKind::from_tokens(&mut tokens) {
1133 Some(item) => result.push(Spanned { span: item.span(), node: item }),
1134 None => return None,
1136 match tokens.next() {
1137 None | Some(TokenTree::Token(_, Token::Comma)) => {}
1141 Some(MetaItemKind::List(result))
1145 impl NestedMetaItemKind {
1146 fn span(&self) -> Span {
1148 NestedMetaItemKind::MetaItem(ref item) => item.span,
1149 NestedMetaItemKind::Literal(ref lit) => lit.span,
1153 fn tokens(&self) -> TokenStream {
1155 NestedMetaItemKind::MetaItem(ref item) => item.tokens(),
1156 NestedMetaItemKind::Literal(ref lit) => lit.tokens(),
1160 fn from_tokens<I>(tokens: &mut iter::Peekable<I>) -> Option<NestedMetaItemKind>
1161 where I: Iterator<Item = TokenTree>,
1163 if let Some(TokenTree::Token(span, token)) = tokens.peek().cloned() {
1164 if let Some(node) = LitKind::from_token(token) {
1166 return Some(NestedMetaItemKind::Literal(Spanned { node: node, span: span }));
1170 MetaItem::from_tokens(tokens).map(NestedMetaItemKind::MetaItem)
1175 fn tokens(&self) -> TokenStream {
1176 TokenTree::Token(self.span, self.node.token()).into()
1181 fn token(&self) -> Token {
1185 LitKind::Str(string, ast::StrStyle::Cooked) => {
1186 let mut escaped = String::new();
1187 for ch in string.as_str().chars() {
1188 escaped.extend(ch.escape_unicode());
1190 Token::Literal(token::Lit::Str_(Symbol::intern(&escaped)), None)
1192 LitKind::Str(string, ast::StrStyle::Raw(n)) => {
1193 Token::Literal(token::Lit::StrRaw(string, n), None)
1195 LitKind::ByteStr(ref bytes) => {
1196 let string = bytes.iter().cloned().flat_map(ascii::escape_default)
1197 .map(Into::<char>::into).collect::<String>();
1198 Token::Literal(token::Lit::ByteStr(Symbol::intern(&string)), None)
1200 LitKind::Byte(byte) => {
1201 let string: String = ascii::escape_default(byte).map(Into::<char>::into).collect();
1202 Token::Literal(token::Lit::Byte(Symbol::intern(&string)), None)
1204 LitKind::Char(ch) => {
1205 let string: String = ch.escape_default().map(Into::<char>::into).collect();
1206 Token::Literal(token::Lit::Char(Symbol::intern(&string)), None)
1208 LitKind::Int(n, ty) => {
1209 let suffix = match ty {
1210 ast::LitIntType::Unsigned(ty) => Some(Symbol::intern(ty.ty_to_string())),
1211 ast::LitIntType::Signed(ty) => Some(Symbol::intern(ty.ty_to_string())),
1212 ast::LitIntType::Unsuffixed => None,
1214 Token::Literal(token::Lit::Integer(Symbol::intern(&n.to_string())), suffix)
1216 LitKind::Float(symbol, ty) => {
1217 Token::Literal(token::Lit::Float(symbol), Some(Symbol::intern(ty.ty_to_string())))
1219 LitKind::FloatUnsuffixed(symbol) => Token::Literal(token::Lit::Float(symbol), None),
1220 LitKind::Bool(value) => Token::Ident(Ident::with_empty_ctxt(Symbol::intern(match value {
1227 fn from_token(token: Token) -> Option<LitKind> {
1229 Token::Ident(ident) if ident.name == "true" => Some(LitKind::Bool(true)),
1230 Token::Ident(ident) if ident.name == "false" => Some(LitKind::Bool(false)),
1231 Token::Interpolated(ref nt) => match **nt {
1232 token::NtExpr(ref v) => match v.node {
1233 ExprKind::Lit(ref lit) => Some(lit.node.clone()),
1238 Token::Literal(lit, suf) => {
1239 let (suffix_illegal, result) = parse::lit_token(lit, suf, None);
1240 if suffix_illegal && suf.is_some() {
1250 pub trait HasAttrs: Sized {
1251 fn attrs(&self) -> &[ast::Attribute];
1252 fn map_attrs<F: FnOnce(Vec<ast::Attribute>) -> Vec<ast::Attribute>>(self, f: F) -> Self;
1255 impl<T: HasAttrs> HasAttrs for Spanned<T> {
1256 fn attrs(&self) -> &[ast::Attribute] { self.node.attrs() }
1257 fn map_attrs<F: FnOnce(Vec<ast::Attribute>) -> Vec<ast::Attribute>>(self, f: F) -> Self {
1258 Spanned { node: self.node.map_attrs(f), span: self.span }
1262 impl HasAttrs for Vec<Attribute> {
1263 fn attrs(&self) -> &[Attribute] {
1266 fn map_attrs<F: FnOnce(Vec<Attribute>) -> Vec<Attribute>>(self, f: F) -> Self {
1271 impl HasAttrs for ThinVec<Attribute> {
1272 fn attrs(&self) -> &[Attribute] {
1275 fn map_attrs<F: FnOnce(Vec<Attribute>) -> Vec<Attribute>>(self, f: F) -> Self {
1276 f(self.into()).into()
1280 impl<T: HasAttrs + 'static> HasAttrs for P<T> {
1281 fn attrs(&self) -> &[Attribute] {
1284 fn map_attrs<F: FnOnce(Vec<Attribute>) -> Vec<Attribute>>(self, f: F) -> Self {
1285 self.map(|t| t.map_attrs(f))
1289 impl HasAttrs for StmtKind {
1290 fn attrs(&self) -> &[Attribute] {
1292 StmtKind::Local(ref local) => local.attrs(),
1293 StmtKind::Item(..) => &[],
1294 StmtKind::Expr(ref expr) | StmtKind::Semi(ref expr) => expr.attrs(),
1295 StmtKind::Mac(ref mac) => {
1296 let (_, _, ref attrs) = **mac;
1302 fn map_attrs<F: FnOnce(Vec<Attribute>) -> Vec<Attribute>>(self, f: F) -> Self {
1304 StmtKind::Local(local) => StmtKind::Local(local.map_attrs(f)),
1305 StmtKind::Item(..) => self,
1306 StmtKind::Expr(expr) => StmtKind::Expr(expr.map_attrs(f)),
1307 StmtKind::Semi(expr) => StmtKind::Semi(expr.map_attrs(f)),
1308 StmtKind::Mac(mac) => StmtKind::Mac(mac.map(|(mac, style, attrs)| {
1309 (mac, style, attrs.map_attrs(f))
1315 impl HasAttrs for Stmt {
1316 fn attrs(&self) -> &[ast::Attribute] { self.node.attrs() }
1317 fn map_attrs<F: FnOnce(Vec<ast::Attribute>) -> Vec<ast::Attribute>>(self, f: F) -> Self {
1318 Stmt { id: self.id, node: self.node.map_attrs(f), span: self.span }
1322 macro_rules! derive_has_attrs {
1323 ($($ty:path),*) => { $(
1324 impl HasAttrs for $ty {
1325 fn attrs(&self) -> &[Attribute] {
1329 fn map_attrs<F>(mut self, f: F) -> Self
1330 where F: FnOnce(Vec<Attribute>) -> Vec<Attribute>,
1332 self.attrs = self.attrs.map_attrs(f);
1340 Item, Expr, Local, ast::ForeignItem, ast::StructField, ast::ImplItem, ast::TraitItem, ast::Arm,
1341 ast::Field, ast::FieldPat, ast::Variant_