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),
270 pub fn meta_item_list(&self) -> Option<&[NestedMetaItem]> {
272 MetaItemKind::List(ref l) => Some(&l[..]),
277 pub fn is_word(&self) -> bool {
279 MetaItemKind::Word => true,
284 pub fn span(&self) -> Span { self.span }
286 pub fn check_name(&self, name: &str) -> bool {
290 pub fn is_value_str(&self) -> bool {
291 self.value_str().is_some()
294 pub fn is_meta_item_list(&self) -> bool {
295 self.meta_item_list().is_some()
300 /// Extract the MetaItem from inside this Attribute.
301 pub fn meta(&self) -> Option<MetaItem> {
302 let mut tokens = self.tokens.trees().peekable();
304 name: match self.path.segments.len() {
305 1 => self.path.segments[0].identifier.name,
308 node: if let Some(node) = MetaItemKind::from_tokens(&mut tokens) {
309 if tokens.peek().is_some() {
320 pub fn parse<'a, T, F>(&self, sess: &'a ParseSess, mut f: F) -> PResult<'a, T>
321 where F: FnMut(&mut Parser<'a>) -> PResult<'a, T>,
323 let mut parser = Parser::new(sess, self.tokens.clone(), None, false, false);
324 let result = f(&mut parser)?;
325 if parser.token != token::Eof {
326 parser.unexpected()?;
331 pub fn parse_list<'a, T, F>(&self, sess: &'a ParseSess, mut f: F) -> PResult<'a, Vec<T>>
332 where F: FnMut(&mut Parser<'a>) -> PResult<'a, T>,
334 if self.tokens.is_empty() {
335 return Ok(Vec::new());
337 self.parse(sess, |parser| {
338 parser.expect(&token::OpenDelim(token::Paren))?;
339 let mut list = Vec::new();
340 while !parser.eat(&token::CloseDelim(token::Paren)) {
341 list.push(f(parser)?);
342 if !parser.eat(&token::Comma) {
343 parser.expect(&token::CloseDelim(token::Paren))?;
351 pub fn parse_meta<'a>(&self, sess: &'a ParseSess) -> PResult<'a, MetaItem> {
352 if self.path.segments.len() > 1 {
353 sess.span_diagnostic.span_err(self.path.span, "expected ident, found path");
357 name: self.path.segments.last().unwrap().identifier.name,
358 node: self.parse(sess, |parser| parser.parse_meta_item_kind())?,
363 /// Convert self to a normal #[doc="foo"] comment, if it is a
364 /// comment like `///` or `/** */`. (Returns self unchanged for
365 /// non-sugared doc attributes.)
366 pub fn with_desugared_doc<T, F>(&self, f: F) -> T where
367 F: FnOnce(&Attribute) -> T,
369 if self.is_sugared_doc {
370 let comment = self.value_str().unwrap();
371 let meta = mk_name_value_item_str(
372 Symbol::intern("doc"),
373 Symbol::intern(&strip_doc_comment_decoration(&comment.as_str())));
374 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 inner attribute with the given value and span.
439 pub fn mk_spanned_attr_inner(sp: Span, id: AttrId, item: MetaItem) -> Attribute {
442 style: ast::AttrStyle::Inner,
443 path: ast::Path::from_ident(item.span, ast::Ident::with_empty_ctxt(item.name)),
444 tokens: item.node.tokens(item.span),
445 is_sugared_doc: false,
451 /// Returns an outer attribute with the given value.
452 pub fn mk_attr_outer(span: Span, id: AttrId, item: MetaItem) -> Attribute {
453 mk_spanned_attr_outer(span, id, item)
456 /// Returns an outer attribute with the given value and span.
457 pub fn mk_spanned_attr_outer(sp: Span, id: AttrId, item: MetaItem) -> Attribute {
460 style: ast::AttrStyle::Outer,
461 path: ast::Path::from_ident(item.span, ast::Ident::with_empty_ctxt(item.name)),
462 tokens: item.node.tokens(item.span),
463 is_sugared_doc: false,
468 pub fn mk_sugared_doc_attr(id: AttrId, text: Symbol, span: Span) -> Attribute {
469 let style = doc_comment_style(&text.as_str());
470 let lit = respan(span, LitKind::Str(text, ast::StrStyle::Cooked));
474 path: ast::Path::from_ident(span, ast::Ident::from_str("doc")),
475 tokens: MetaItemKind::NameValue(lit).tokens(span),
476 is_sugared_doc: true,
481 pub fn list_contains_name(items: &[NestedMetaItem], name: &str) -> bool {
482 items.iter().any(|item| {
483 item.check_name(name)
487 pub fn contains_name(attrs: &[Attribute], name: &str) -> bool {
488 attrs.iter().any(|item| {
489 item.check_name(name)
493 pub fn find_by_name<'a>(attrs: &'a [Attribute], name: &str) -> Option<&'a Attribute> {
494 attrs.iter().find(|attr| attr.check_name(name))
497 pub fn first_attr_value_str_by_name(attrs: &[Attribute], name: &str) -> Option<Symbol> {
499 .find(|at| at.check_name(name))
500 .and_then(|at| at.value_str())
503 /* Higher-level applications */
505 pub fn find_crate_name(attrs: &[Attribute]) -> Option<Symbol> {
506 first_attr_value_str_by_name(attrs, "crate_name")
509 /// Find the value of #[export_name=*] attribute and check its validity.
510 pub fn find_export_name_attr(diag: &Handler, attrs: &[Attribute]) -> Option<Symbol> {
511 attrs.iter().fold(None, |ia,attr| {
512 if attr.check_name("export_name") {
513 if let s@Some(_) = attr.value_str() {
516 struct_span_err!(diag, attr.span, E0558,
517 "export_name attribute has invalid format")
518 .span_label(attr.span, "did you mean #[export_name=\"*\"]?")
528 pub fn contains_extern_indicator(diag: &Handler, attrs: &[Attribute]) -> bool {
529 contains_name(attrs, "no_mangle") ||
530 find_export_name_attr(diag, attrs).is_some()
533 #[derive(Copy, Clone, PartialEq)]
534 pub enum InlineAttr {
541 /// Determine what `#[inline]` attribute is present in `attrs`, if any.
542 pub fn find_inline_attr(diagnostic: Option<&Handler>, attrs: &[Attribute]) -> InlineAttr {
543 attrs.iter().fold(InlineAttr::None, |ia, attr| {
544 if attr.path != "inline" {
547 let meta = match attr.meta() {
548 Some(meta) => meta.node,
552 MetaItemKind::Word => {
556 MetaItemKind::List(ref items) => {
558 if items.len() != 1 {
559 diagnostic.map(|d|{ span_err!(d, attr.span, E0534, "expected one argument"); });
561 } else if list_contains_name(&items[..], "always") {
563 } else if list_contains_name(&items[..], "never") {
567 span_err!(d, items[0].span, E0535, "invalid argument");
578 /// True if `#[inline]` or `#[inline(always)]` is present in `attrs`.
579 pub fn requests_inline(attrs: &[Attribute]) -> bool {
580 match find_inline_attr(None, attrs) {
581 InlineAttr::Hint | InlineAttr::Always => true,
582 InlineAttr::None | InlineAttr::Never => false,
586 /// Tests if a cfg-pattern matches the cfg set
587 pub fn cfg_matches(cfg: &ast::MetaItem, sess: &ParseSess, features: Option<&Features>) -> bool {
588 eval_condition(cfg, sess, &mut |cfg| {
589 if let (Some(feats), Some(gated_cfg)) = (features, GatedCfg::gate(cfg)) {
590 gated_cfg.check_and_emit(sess, feats);
592 sess.config.contains(&(cfg.name(), cfg.value_str()))
596 /// Evaluate a cfg-like condition (with `any` and `all`), using `eval` to
597 /// evaluate individual items.
598 pub fn eval_condition<F>(cfg: &ast::MetaItem, sess: &ParseSess, eval: &mut F)
600 where F: FnMut(&ast::MetaItem) -> bool
603 ast::MetaItemKind::List(ref mis) => {
604 for mi in mis.iter() {
605 if !mi.is_meta_item() {
606 handle_errors(&sess.span_diagnostic, mi.span, AttrError::UnsupportedLiteral);
611 // The unwraps below may look dangerous, but we've already asserted
612 // that they won't fail with the loop above.
613 match &*cfg.name.as_str() {
614 "any" => mis.iter().any(|mi| {
615 eval_condition(mi.meta_item().unwrap(), sess, eval)
617 "all" => mis.iter().all(|mi| {
618 eval_condition(mi.meta_item().unwrap(), sess, eval)
622 span_err!(sess.span_diagnostic, cfg.span, E0536, "expected 1 cfg-pattern");
626 !eval_condition(mis[0].meta_item().unwrap(), sess, eval)
629 span_err!(sess.span_diagnostic, cfg.span, E0537, "invalid predicate `{}`", p);
634 ast::MetaItemKind::Word | ast::MetaItemKind::NameValue(..) => {
640 /// Represents the #[stable], #[unstable], #[rustc_{deprecated,const_unstable}] attributes.
641 #[derive(RustcEncodable, RustcDecodable, Clone, Debug, PartialEq, Eq, Hash)]
642 pub struct Stability {
643 pub level: StabilityLevel,
645 pub rustc_depr: Option<RustcDeprecation>,
646 pub rustc_const_unstable: Option<RustcConstUnstable>,
649 /// The available stability levels.
650 #[derive(RustcEncodable, RustcDecodable, PartialEq, PartialOrd, Clone, Debug, Eq, Hash)]
651 pub enum StabilityLevel {
652 // Reason for the current stability level and the relevant rust-lang issue
653 Unstable { reason: Option<Symbol>, issue: u32 },
654 Stable { since: Symbol },
657 #[derive(RustcEncodable, RustcDecodable, PartialEq, PartialOrd, Clone, Debug, Eq, Hash)]
658 pub struct RustcDeprecation {
663 #[derive(RustcEncodable, RustcDecodable, PartialEq, PartialOrd, Clone, Debug, Eq, Hash)]
664 pub struct RustcConstUnstable {
668 #[derive(RustcEncodable, RustcDecodable, PartialEq, PartialOrd, Clone, Debug, Eq, Hash)]
669 pub struct Deprecation {
670 pub since: Option<Symbol>,
671 pub note: Option<Symbol>,
674 impl StabilityLevel {
675 pub fn is_unstable(&self) -> bool { if let Unstable {..} = *self { true } else { false }}
676 pub fn is_stable(&self) -> bool { if let Stable {..} = *self { true } else { false }}
679 fn find_stability_generic<'a, I>(diagnostic: &Handler,
683 where I: Iterator<Item = &'a Attribute>
685 let mut stab: Option<Stability> = None;
686 let mut rustc_depr: Option<RustcDeprecation> = None;
687 let mut rustc_const_unstable: Option<RustcConstUnstable> = None;
689 'outer: for attr in attrs_iter {
692 "rustc_const_unstable",
695 ].iter().any(|&s| attr.path == s) {
696 continue // not a stability level
701 let meta = attr.meta();
702 if let Some(MetaItem { node: MetaItemKind::List(ref metas), .. }) = meta {
703 let meta = meta.as_ref().unwrap();
704 let get = |meta: &MetaItem, item: &mut Option<Symbol>| {
706 handle_errors(diagnostic, meta.span, AttrError::MultipleItem(meta.name()));
709 if let Some(v) = meta.value_str() {
713 span_err!(diagnostic, meta.span, E0539, "incorrect meta item");
718 macro_rules! get_meta {
719 ($($name:ident),+) => {
721 let mut $name = None;
724 if let Some(mi) = meta.meta_item() {
725 match &*mi.name().as_str() {
728 => if !get(mi, &mut $name) { continue 'outer },
731 handle_errors(diagnostic, mi.span,
732 AttrError::UnknownMetaItem(mi.name()));
737 handle_errors(diagnostic, meta.span, AttrError::UnsupportedLiteral);
744 match &*meta.name.as_str() {
745 "rustc_deprecated" => {
746 if rustc_depr.is_some() {
747 span_err!(diagnostic, item_sp, E0540,
748 "multiple rustc_deprecated attributes");
752 get_meta!(since, reason);
754 match (since, reason) {
755 (Some(since), Some(reason)) => {
756 rustc_depr = Some(RustcDeprecation {
762 handle_errors(diagnostic, attr.span(), AttrError::MissingSince);
766 span_err!(diagnostic, attr.span(), E0543, "missing 'reason'");
771 "rustc_const_unstable" => {
772 if rustc_const_unstable.is_some() {
773 span_err!(diagnostic, item_sp, E0553,
774 "multiple rustc_const_unstable attributes");
779 if let Some(feature) = feature {
780 rustc_const_unstable = Some(RustcConstUnstable {
784 span_err!(diagnostic, attr.span(), E0629, "missing 'feature'");
790 handle_errors(diagnostic, attr.span(), AttrError::MultipleStabilityLevels);
794 let mut feature = None;
795 let mut reason = None;
796 let mut issue = None;
798 if let Some(mi) = meta.meta_item() {
799 match &*mi.name().as_str() {
800 "feature" => if !get(mi, &mut feature) { continue 'outer },
801 "reason" => if !get(mi, &mut reason) { continue 'outer },
802 "issue" => if !get(mi, &mut issue) { continue 'outer },
804 handle_errors(diagnostic, meta.span,
805 AttrError::UnknownMetaItem(mi.name()));
810 handle_errors(diagnostic, meta.span, AttrError::UnsupportedLiteral);
815 match (feature, reason, issue) {
816 (Some(feature), reason, Some(issue)) => {
817 stab = Some(Stability {
821 if let Ok(issue) = issue.as_str().parse() {
824 span_err!(diagnostic, attr.span(), E0545,
825 "incorrect 'issue'");
832 rustc_const_unstable: None,
836 handle_errors(diagnostic, attr.span(), AttrError::MissingFeature);
840 span_err!(diagnostic, attr.span(), E0547, "missing 'issue'");
847 handle_errors(diagnostic, attr.span(), AttrError::MultipleStabilityLevels);
851 let mut feature = None;
852 let mut since = None;
854 if let NestedMetaItemKind::MetaItem(ref mi) = meta.node {
855 match &*mi.name().as_str() {
856 "feature" => if !get(mi, &mut feature) { continue 'outer },
857 "since" => if !get(mi, &mut since) { continue 'outer },
859 handle_errors(diagnostic, meta.span,
860 AttrError::UnknownMetaItem(mi.name()));
865 handle_errors(diagnostic, meta.span, AttrError::UnsupportedLiteral);
870 match (feature, since) {
871 (Some(feature), Some(since)) => {
872 stab = Some(Stability {
878 rustc_const_unstable: None,
882 handle_errors(diagnostic, attr.span(), AttrError::MissingFeature);
886 handle_errors(diagnostic, attr.span(), AttrError::MissingSince);
894 span_err!(diagnostic, attr.span(), E0548, "incorrect stability attribute type");
899 // Merge the deprecation info into the stability info
900 if let Some(rustc_depr) = rustc_depr {
901 if let Some(ref mut stab) = stab {
902 stab.rustc_depr = Some(rustc_depr);
904 span_err!(diagnostic, item_sp, E0549,
905 "rustc_deprecated attribute must be paired with \
906 either stable or unstable attribute");
910 // Merge the const-unstable info into the stability info
911 if let Some(rustc_const_unstable) = rustc_const_unstable {
912 if let Some(ref mut stab) = stab {
913 stab.rustc_const_unstable = Some(rustc_const_unstable);
915 span_err!(diagnostic, item_sp, E0630,
916 "rustc_const_unstable attribute must be paired with \
917 either stable or unstable attribute");
924 fn find_deprecation_generic<'a, I>(diagnostic: &Handler,
927 -> Option<Deprecation>
928 where I: Iterator<Item = &'a Attribute>
930 let mut depr: Option<Deprecation> = None;
932 'outer: for attr in attrs_iter {
933 if attr.path != "deprecated" {
940 span_err!(diagnostic, item_sp, E0550, "multiple deprecated attributes");
944 depr = if let Some(metas) = attr.meta_item_list() {
945 let get = |meta: &MetaItem, item: &mut Option<Symbol>| {
947 handle_errors(diagnostic, meta.span, AttrError::MultipleItem(meta.name()));
950 if let Some(v) = meta.value_str() {
954 span_err!(diagnostic, meta.span, E0551, "incorrect meta item");
959 let mut since = None;
962 if let NestedMetaItemKind::MetaItem(ref mi) = meta.node {
963 match &*mi.name().as_str() {
964 "since" => if !get(mi, &mut since) { continue 'outer },
965 "note" => if !get(mi, &mut note) { continue 'outer },
967 handle_errors(diagnostic, meta.span,
968 AttrError::UnknownMetaItem(mi.name()));
973 handle_errors(diagnostic, meta.span, AttrError::UnsupportedLiteral);
978 Some(Deprecation {since: since, note: note})
980 Some(Deprecation{since: None, note: None})
987 /// Find the first stability attribute. `None` if none exists.
988 pub fn find_stability(diagnostic: &Handler, attrs: &[Attribute],
989 item_sp: Span) -> Option<Stability> {
990 find_stability_generic(diagnostic, attrs.iter(), item_sp)
993 /// Find the deprecation attribute. `None` if none exists.
994 pub fn find_deprecation(diagnostic: &Handler, attrs: &[Attribute],
995 item_sp: Span) -> Option<Deprecation> {
996 find_deprecation_generic(diagnostic, attrs.iter(), item_sp)
1000 /// Parse #[repr(...)] forms.
1002 /// Valid repr contents: any of the primitive integral type names (see
1003 /// `int_type_of_word`, below) to specify enum discriminant type; `C`, to use
1004 /// the same discriminant size that the corresponding C enum would or C
1005 /// structure layout, and `packed` to remove padding.
1006 pub fn find_repr_attrs(diagnostic: &Handler, attr: &Attribute) -> Vec<ReprAttr> {
1007 let mut acc = Vec::new();
1008 if attr.path == "repr" {
1009 if let Some(items) = attr.meta_item_list() {
1012 if !item.is_meta_item() {
1013 handle_errors(diagnostic, item.span, AttrError::UnsupportedLiteral);
1017 let mut recognised = false;
1018 if let Some(mi) = item.word() {
1019 let word = &*mi.name().as_str();
1020 let hint = match word {
1021 // Can't use "extern" because it's not a lexical identifier.
1022 "C" => Some(ReprExtern),
1023 "packed" => Some(ReprPacked),
1024 "simd" => Some(ReprSimd),
1025 _ => match int_type_of_word(word) {
1026 Some(ity) => Some(ReprInt(ity)),
1033 if let Some(h) = hint {
1037 } else if let Some((name, value)) = item.name_value_literal() {
1038 if name == "align" {
1040 let mut align_error = None;
1041 if let ast::LitKind::Int(align, ast::LitIntType::Unsuffixed) = value.node {
1042 if align.is_power_of_two() {
1043 // rustc::ty::layout::Align restricts align to <= 2147483647
1044 if align <= 2147483647 {
1045 acc.push(ReprAlign(align as u32));
1047 align_error = Some("larger than 2147483647");
1050 align_error = Some("not a power of two");
1053 align_error = Some("not an unsuffixed integer");
1055 if let Some(align_error) = align_error {
1056 span_err!(diagnostic, item.span, E0589,
1057 "invalid `repr(align)` attribute: {}", align_error);
1062 // Not a word we recognize
1063 span_err!(diagnostic, item.span, E0552,
1064 "unrecognized representation hint");
1072 fn int_type_of_word(s: &str) -> Option<IntType> {
1074 "i8" => Some(SignedInt(ast::IntTy::I8)),
1075 "u8" => Some(UnsignedInt(ast::UintTy::U8)),
1076 "i16" => Some(SignedInt(ast::IntTy::I16)),
1077 "u16" => Some(UnsignedInt(ast::UintTy::U16)),
1078 "i32" => Some(SignedInt(ast::IntTy::I32)),
1079 "u32" => Some(UnsignedInt(ast::UintTy::U32)),
1080 "i64" => Some(SignedInt(ast::IntTy::I64)),
1081 "u64" => Some(UnsignedInt(ast::UintTy::U64)),
1082 "i128" => Some(SignedInt(ast::IntTy::I128)),
1083 "u128" => Some(UnsignedInt(ast::UintTy::U128)),
1084 "isize" => Some(SignedInt(ast::IntTy::Is)),
1085 "usize" => Some(UnsignedInt(ast::UintTy::Us)),
1090 #[derive(PartialEq, Debug, RustcEncodable, RustcDecodable, Copy, Clone)]
1099 #[derive(Eq, Hash, PartialEq, Debug, RustcEncodable, RustcDecodable, Copy, Clone)]
1101 SignedInt(ast::IntTy),
1102 UnsignedInt(ast::UintTy)
1107 pub fn is_signed(self) -> bool {
1109 SignedInt(..) => true,
1110 UnsignedInt(..) => false
1116 fn tokens(&self) -> TokenStream {
1117 let ident = TokenTree::Token(self.span, Token::Ident(Ident::with_empty_ctxt(self.name)));
1118 TokenStream::concat(vec![ident.into(), self.node.tokens(self.span)])
1121 fn from_tokens<I>(tokens: &mut iter::Peekable<I>) -> Option<MetaItem>
1122 where I: Iterator<Item = TokenTree>,
1124 let (span, name) = match tokens.next() {
1125 Some(TokenTree::Token(span, Token::Ident(ident))) => (span, ident.name),
1126 Some(TokenTree::Token(_, Token::Interpolated(ref nt))) => match nt.0 {
1127 token::Nonterminal::NtIdent(ident) => (ident.span, ident.node.name),
1128 token::Nonterminal::NtMeta(ref meta) => return Some(meta.clone()),
1133 let list_closing_paren_pos = tokens.peek().map(|tt| tt.span().hi());
1134 let node = match MetaItemKind::from_tokens(tokens) {
1138 let hi = match node {
1139 MetaItemKind::NameValue(ref lit) => lit.span.hi(),
1140 MetaItemKind::List(..) => list_closing_paren_pos.unwrap_or(span.hi()),
1143 Some(MetaItem { name, node, span: span.with_hi(hi) })
1148 pub fn tokens(&self, span: Span) -> TokenStream {
1150 MetaItemKind::Word => TokenStream::empty(),
1151 MetaItemKind::NameValue(ref lit) => {
1152 TokenStream::concat(vec![TokenTree::Token(span, Token::Eq).into(), lit.tokens()])
1154 MetaItemKind::List(ref list) => {
1155 let mut tokens = Vec::new();
1156 for (i, item) in list.iter().enumerate() {
1158 tokens.push(TokenTree::Token(span, Token::Comma).into());
1160 tokens.push(item.node.tokens());
1162 TokenTree::Delimited(span, Delimited {
1163 delim: token::Paren,
1164 tts: TokenStream::concat(tokens).into(),
1170 fn from_tokens<I>(tokens: &mut iter::Peekable<I>) -> Option<MetaItemKind>
1171 where I: Iterator<Item = TokenTree>,
1173 let delimited = match tokens.peek().cloned() {
1174 Some(TokenTree::Token(_, token::Eq)) => {
1176 return if let Some(TokenTree::Token(span, token)) = tokens.next() {
1177 LitKind::from_token(token)
1178 .map(|lit| MetaItemKind::NameValue(Spanned { node: lit, span: span }))
1183 Some(TokenTree::Delimited(_, ref delimited)) if delimited.delim == token::Paren => {
1187 _ => return Some(MetaItemKind::Word),
1190 let mut tokens = delimited.into_trees().peekable();
1191 let mut result = Vec::new();
1192 while let Some(..) = tokens.peek() {
1193 match NestedMetaItemKind::from_tokens(&mut tokens) {
1194 Some(item) => result.push(respan(item.span(), item)),
1195 None => return None,
1197 match tokens.next() {
1198 None | Some(TokenTree::Token(_, Token::Comma)) => {}
1202 Some(MetaItemKind::List(result))
1206 impl NestedMetaItemKind {
1207 fn span(&self) -> Span {
1209 NestedMetaItemKind::MetaItem(ref item) => item.span,
1210 NestedMetaItemKind::Literal(ref lit) => lit.span,
1214 fn tokens(&self) -> TokenStream {
1216 NestedMetaItemKind::MetaItem(ref item) => item.tokens(),
1217 NestedMetaItemKind::Literal(ref lit) => lit.tokens(),
1221 fn from_tokens<I>(tokens: &mut iter::Peekable<I>) -> Option<NestedMetaItemKind>
1222 where I: Iterator<Item = TokenTree>,
1224 if let Some(TokenTree::Token(span, token)) = tokens.peek().cloned() {
1225 if let Some(node) = LitKind::from_token(token) {
1227 return Some(NestedMetaItemKind::Literal(respan(span, node)));
1231 MetaItem::from_tokens(tokens).map(NestedMetaItemKind::MetaItem)
1236 fn tokens(&self) -> TokenStream {
1237 TokenTree::Token(self.span, self.node.token()).into()
1242 fn token(&self) -> Token {
1246 LitKind::Str(string, ast::StrStyle::Cooked) => {
1247 let mut escaped = String::new();
1248 for ch in string.as_str().chars() {
1249 escaped.extend(ch.escape_unicode());
1251 Token::Literal(token::Lit::Str_(Symbol::intern(&escaped)), None)
1253 LitKind::Str(string, ast::StrStyle::Raw(n)) => {
1254 Token::Literal(token::Lit::StrRaw(string, n), None)
1256 LitKind::ByteStr(ref bytes) => {
1257 let string = bytes.iter().cloned().flat_map(ascii::escape_default)
1258 .map(Into::<char>::into).collect::<String>();
1259 Token::Literal(token::Lit::ByteStr(Symbol::intern(&string)), None)
1261 LitKind::Byte(byte) => {
1262 let string: String = ascii::escape_default(byte).map(Into::<char>::into).collect();
1263 Token::Literal(token::Lit::Byte(Symbol::intern(&string)), None)
1265 LitKind::Char(ch) => {
1266 let string: String = ch.escape_default().map(Into::<char>::into).collect();
1267 Token::Literal(token::Lit::Char(Symbol::intern(&string)), None)
1269 LitKind::Int(n, ty) => {
1270 let suffix = match ty {
1271 ast::LitIntType::Unsigned(ty) => Some(Symbol::intern(ty.ty_to_string())),
1272 ast::LitIntType::Signed(ty) => Some(Symbol::intern(ty.ty_to_string())),
1273 ast::LitIntType::Unsuffixed => None,
1275 Token::Literal(token::Lit::Integer(Symbol::intern(&n.to_string())), suffix)
1277 LitKind::Float(symbol, ty) => {
1278 Token::Literal(token::Lit::Float(symbol), Some(Symbol::intern(ty.ty_to_string())))
1280 LitKind::FloatUnsuffixed(symbol) => Token::Literal(token::Lit::Float(symbol), None),
1281 LitKind::Bool(value) => Token::Ident(Ident::with_empty_ctxt(Symbol::intern(if value {
1289 fn from_token(token: Token) -> Option<LitKind> {
1291 Token::Ident(ident) if ident.name == "true" => Some(LitKind::Bool(true)),
1292 Token::Ident(ident) if ident.name == "false" => Some(LitKind::Bool(false)),
1293 Token::Interpolated(ref nt) => match nt.0 {
1294 token::NtExpr(ref v) => match v.node {
1295 ExprKind::Lit(ref lit) => Some(lit.node.clone()),
1300 Token::Literal(lit, suf) => {
1301 let (suffix_illegal, result) = parse::lit_token(lit, suf, None);
1302 if suffix_illegal && suf.is_some() {
1312 pub trait HasAttrs: Sized {
1313 fn attrs(&self) -> &[ast::Attribute];
1314 fn map_attrs<F: FnOnce(Vec<ast::Attribute>) -> Vec<ast::Attribute>>(self, f: F) -> Self;
1317 impl<T: HasAttrs> HasAttrs for Spanned<T> {
1318 fn attrs(&self) -> &[ast::Attribute] { self.node.attrs() }
1319 fn map_attrs<F: FnOnce(Vec<ast::Attribute>) -> Vec<ast::Attribute>>(self, f: F) -> Self {
1320 respan(self.span, self.node.map_attrs(f))
1324 impl HasAttrs for Vec<Attribute> {
1325 fn attrs(&self) -> &[Attribute] {
1328 fn map_attrs<F: FnOnce(Vec<Attribute>) -> Vec<Attribute>>(self, f: F) -> Self {
1333 impl HasAttrs for ThinVec<Attribute> {
1334 fn attrs(&self) -> &[Attribute] {
1337 fn map_attrs<F: FnOnce(Vec<Attribute>) -> Vec<Attribute>>(self, f: F) -> Self {
1338 f(self.into()).into()
1342 impl<T: HasAttrs + 'static> HasAttrs for P<T> {
1343 fn attrs(&self) -> &[Attribute] {
1346 fn map_attrs<F: FnOnce(Vec<Attribute>) -> Vec<Attribute>>(self, f: F) -> Self {
1347 self.map(|t| t.map_attrs(f))
1351 impl HasAttrs for StmtKind {
1352 fn attrs(&self) -> &[Attribute] {
1354 StmtKind::Local(ref local) => local.attrs(),
1355 StmtKind::Item(..) => &[],
1356 StmtKind::Expr(ref expr) | StmtKind::Semi(ref expr) => expr.attrs(),
1357 StmtKind::Mac(ref mac) => {
1358 let (_, _, ref attrs) = **mac;
1364 fn map_attrs<F: FnOnce(Vec<Attribute>) -> Vec<Attribute>>(self, f: F) -> Self {
1366 StmtKind::Local(local) => StmtKind::Local(local.map_attrs(f)),
1367 StmtKind::Item(..) => self,
1368 StmtKind::Expr(expr) => StmtKind::Expr(expr.map_attrs(f)),
1369 StmtKind::Semi(expr) => StmtKind::Semi(expr.map_attrs(f)),
1370 StmtKind::Mac(mac) => StmtKind::Mac(mac.map(|(mac, style, attrs)| {
1371 (mac, style, attrs.map_attrs(f))
1377 impl HasAttrs for Stmt {
1378 fn attrs(&self) -> &[ast::Attribute] { self.node.attrs() }
1379 fn map_attrs<F: FnOnce(Vec<ast::Attribute>) -> Vec<ast::Attribute>>(self, f: F) -> Self {
1380 Stmt { id: self.id, node: self.node.map_attrs(f), span: self.span }
1384 macro_rules! derive_has_attrs {
1385 ($($ty:path),*) => { $(
1386 impl HasAttrs for $ty {
1387 fn attrs(&self) -> &[Attribute] {
1391 fn map_attrs<F>(mut self, f: F) -> Self
1392 where F: FnOnce(Vec<Attribute>) -> Vec<Attribute>,
1394 self.attrs = self.attrs.map_attrs(f);
1402 Item, Expr, Local, ast::ForeignItem, ast::StructField, ast::ImplItem, ast::TraitItem, ast::Arm,
1403 ast::Field, ast::FieldPat, ast::Variant_