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};
24 use feature_gate::{Features, GatedCfg};
25 use parse::lexer::comments::{doc_comment_style, strip_doc_comment_decoration};
26 use parse::parser::Parser;
27 use parse::{self, ParseSess, PResult};
28 use parse::token::{self, Token};
31 use tokenstream::{TokenStream, TokenTree, Delimited};
39 UnknownMetaItem(Name),
42 MultipleStabilityLevels,
46 fn handle_errors(diag: &Handler, span: Span, error: AttrError) {
48 AttrError::MultipleItem(item) => span_err!(diag, span, E0538,
49 "multiple '{}' items", item),
50 AttrError::UnknownMetaItem(item) => span_err!(diag, span, E0541,
51 "unknown meta item '{}'", item),
52 AttrError::MissingSince => span_err!(diag, span, E0542, "missing 'since'"),
53 AttrError::MissingFeature => span_err!(diag, span, E0546, "missing 'feature'"),
54 AttrError::MultipleStabilityLevels => span_err!(diag, span, E0544,
55 "multiple stability levels"),
56 AttrError::UnsupportedLiteral => span_err!(diag, span, E0565, "unsupported literal"),
60 pub fn mark_used(attr: &Attribute) {
61 debug!("Marking {:?} as used.", attr);
62 let AttrId(id) = attr.id;
63 GLOBALS.with(|globals| {
64 let mut slot = globals.used_attrs.lock();
65 let idx = (id / 64) as usize;
67 if slot.len() <= idx {
68 slot.resize(idx + 1, 0);
70 slot[idx] |= 1 << shift;
74 pub fn is_used(attr: &Attribute) -> bool {
75 let AttrId(id) = attr.id;
76 GLOBALS.with(|globals| {
77 let slot = globals.used_attrs.lock();
78 let idx = (id / 64) as usize;
80 slot.get(idx).map(|bits| bits & (1 << shift) != 0)
85 pub fn mark_known(attr: &Attribute) {
86 debug!("Marking {:?} as known.", attr);
87 let AttrId(id) = attr.id;
88 GLOBALS.with(|globals| {
89 let mut slot = globals.known_attrs.lock();
90 let idx = (id / 64) as usize;
92 if slot.len() <= idx {
93 slot.resize(idx + 1, 0);
95 slot[idx] |= 1 << shift;
99 pub fn is_known(attr: &Attribute) -> bool {
100 let AttrId(id) = attr.id;
101 GLOBALS.with(|globals| {
102 let slot = globals.known_attrs.lock();
103 let idx = (id / 64) as usize;
105 slot.get(idx).map(|bits| bits & (1 << shift) != 0)
110 impl NestedMetaItem {
111 /// Returns the MetaItem if self is a NestedMetaItemKind::MetaItem.
112 pub fn meta_item(&self) -> Option<&MetaItem> {
114 NestedMetaItemKind::MetaItem(ref item) => Some(item),
119 /// Returns the Lit if self is a NestedMetaItemKind::Literal.
120 pub fn literal(&self) -> Option<&Lit> {
122 NestedMetaItemKind::Literal(ref lit) => Some(lit),
127 /// Returns the Span for `self`.
128 pub fn span(&self) -> Span {
132 /// Returns true if this list item is a MetaItem with a name of `name`.
133 pub fn check_name(&self, name: &str) -> bool {
134 self.meta_item().map_or(false, |meta_item| meta_item.check_name(name))
137 /// Returns the name of the meta item, e.g. `foo` in `#[foo]`,
138 /// `#[foo="bar"]` and `#[foo(bar)]`, if self is a MetaItem
139 pub fn name(&self) -> Option<Name> {
140 self.meta_item().and_then(|meta_item| Some(meta_item.ident.name))
143 /// Gets the string value if self is a MetaItem and the MetaItem is a
144 /// MetaItemKind::NameValue variant containing a string, otherwise None.
145 pub fn value_str(&self) -> Option<Symbol> {
146 self.meta_item().and_then(|meta_item| meta_item.value_str())
149 /// Returns a name and single literal value tuple of the MetaItem.
150 pub fn name_value_literal(&self) -> Option<(Name, &Lit)> {
151 self.meta_item().and_then(
152 |meta_item| meta_item.meta_item_list().and_then(
154 if meta_item_list.len() == 1 {
155 let nested_item = &meta_item_list[0];
156 if nested_item.is_literal() {
157 Some((meta_item.ident.name, nested_item.literal().unwrap()))
167 /// Returns a MetaItem if self is a MetaItem with Kind Word.
168 pub fn word(&self) -> Option<&MetaItem> {
169 self.meta_item().and_then(|meta_item| if meta_item.is_word() {
176 /// Gets a list of inner meta items from a list MetaItem type.
177 pub fn meta_item_list(&self) -> Option<&[NestedMetaItem]> {
178 self.meta_item().and_then(|meta_item| meta_item.meta_item_list())
181 /// Returns `true` if the variant is MetaItem.
182 pub fn is_meta_item(&self) -> bool {
183 self.meta_item().is_some()
186 /// Returns `true` if the variant is Literal.
187 pub fn is_literal(&self) -> bool {
188 self.literal().is_some()
191 /// Returns `true` if self is a MetaItem and the meta item is a word.
192 pub fn is_word(&self) -> bool {
193 self.word().is_some()
196 /// Returns `true` if self is a MetaItem and the meta item is a ValueString.
197 pub fn is_value_str(&self) -> bool {
198 self.value_str().is_some()
201 /// Returns `true` if self is a MetaItem and the meta item is a list.
202 pub fn is_meta_item_list(&self) -> bool {
203 self.meta_item_list().is_some()
208 pub fn check_name(&self, name: &str) -> bool {
209 let matches = self.path == name;
216 pub fn name(&self) -> Option<Name> {
217 match self.path.segments.len() {
218 1 => Some(self.path.segments[0].ident.name),
223 pub fn value_str(&self) -> Option<Symbol> {
224 self.meta().and_then(|meta| meta.value_str())
227 pub fn meta_item_list(&self) -> Option<Vec<NestedMetaItem>> {
229 Some(MetaItem { node: MetaItemKind::List(list), .. }) => Some(list),
234 pub fn is_word(&self) -> bool {
235 self.path.segments.len() == 1 && self.tokens.is_empty()
238 pub fn span(&self) -> Span {
242 pub fn is_meta_item_list(&self) -> bool {
243 self.meta_item_list().is_some()
246 /// Indicates if the attribute is a Value String.
247 pub fn is_value_str(&self) -> bool {
248 self.value_str().is_some()
253 pub fn value_str(&self) -> Option<Symbol> {
255 MetaItemKind::NameValue(ref v) => {
257 LitKind::Str(ref s, _) => Some(*s),
265 pub fn meta_item_list(&self) -> Option<&[NestedMetaItem]> {
267 MetaItemKind::List(ref l) => Some(&l[..]),
272 pub fn is_word(&self) -> bool {
274 MetaItemKind::Word => true,
279 pub fn span(&self) -> Span { self.span }
281 pub fn check_name(&self, name: &str) -> bool {
282 self.ident.name == name
285 pub fn is_value_str(&self) -> bool {
286 self.value_str().is_some()
289 pub fn is_meta_item_list(&self) -> bool {
290 self.meta_item_list().is_some()
295 /// Extract the MetaItem from inside this Attribute.
296 pub fn meta(&self) -> Option<MetaItem> {
297 let mut tokens = self.tokens.trees().peekable();
299 ident: match self.path.segments.len() {
300 1 => self.path.segments[0].ident,
303 node: if let Some(node) = MetaItemKind::from_tokens(&mut tokens) {
304 if tokens.peek().is_some() {
315 pub fn parse<'a, T, F>(&self, sess: &'a ParseSess, mut f: F) -> PResult<'a, T>
316 where F: FnMut(&mut Parser<'a>) -> PResult<'a, T>,
318 let mut parser = Parser::new(sess, self.tokens.clone(), None, false, false);
319 let result = f(&mut parser)?;
320 if parser.token != token::Eof {
321 parser.unexpected()?;
326 pub fn parse_list<'a, T, F>(&self, sess: &'a ParseSess, mut f: F) -> PResult<'a, Vec<T>>
327 where F: FnMut(&mut Parser<'a>) -> PResult<'a, T>,
329 if self.tokens.is_empty() {
330 return Ok(Vec::new());
332 self.parse(sess, |parser| {
333 parser.expect(&token::OpenDelim(token::Paren))?;
334 let mut list = Vec::new();
335 while !parser.eat(&token::CloseDelim(token::Paren)) {
336 list.push(f(parser)?);
337 if !parser.eat(&token::Comma) {
338 parser.expect(&token::CloseDelim(token::Paren))?;
346 pub fn parse_meta<'a>(&self, sess: &'a ParseSess) -> PResult<'a, MetaItem> {
347 if self.path.segments.len() > 1 {
348 sess.span_diagnostic.span_err(self.path.span, "expected ident, found path");
352 ident: self.path.segments.last().unwrap().ident,
353 node: self.parse(sess, |parser| parser.parse_meta_item_kind())?,
358 /// Convert self to a normal #[doc="foo"] comment, if it is a
359 /// comment like `///` or `/** */`. (Returns self unchanged for
360 /// non-sugared doc attributes.)
361 pub fn with_desugared_doc<T, F>(&self, f: F) -> T where
362 F: FnOnce(&Attribute) -> T,
364 if self.is_sugared_doc {
365 let comment = self.value_str().unwrap();
366 let meta = mk_name_value_item_str(
367 Ident::from_str("doc"),
368 dummy_spanned(Symbol::intern(&strip_doc_comment_decoration(&comment.as_str()))));
369 let mut attr = if self.style == ast::AttrStyle::Outer {
370 mk_attr_outer(self.span, self.id, meta)
372 mk_attr_inner(self.span, self.id, meta)
374 attr.is_sugared_doc = true;
384 pub fn mk_name_value_item_str(ident: Ident, value: Spanned<Symbol>) -> MetaItem {
385 let value = respan(value.span, LitKind::Str(value.node, ast::StrStyle::Cooked));
386 mk_name_value_item(ident.span.to(value.span), ident, value)
389 pub fn mk_name_value_item(span: Span, ident: Ident, value: ast::Lit) -> MetaItem {
390 MetaItem { ident, span, node: MetaItemKind::NameValue(value) }
393 pub fn mk_list_item(span: Span, ident: Ident, items: Vec<NestedMetaItem>) -> MetaItem {
394 MetaItem { ident, span, node: MetaItemKind::List(items) }
397 pub fn mk_word_item(ident: Ident) -> MetaItem {
398 MetaItem { ident, span: ident.span, node: MetaItemKind::Word }
400 pub fn mk_nested_word_item(ident: Ident) -> NestedMetaItem {
401 respan(ident.span, NestedMetaItemKind::MetaItem(mk_word_item(ident)))
404 pub fn mk_attr_id() -> AttrId {
405 use std::sync::atomic::AtomicUsize;
406 use std::sync::atomic::Ordering;
408 static NEXT_ATTR_ID: AtomicUsize = AtomicUsize::new(0);
410 let id = NEXT_ATTR_ID.fetch_add(1, Ordering::SeqCst);
411 assert!(id != ::std::usize::MAX);
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 inner 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.ident),
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.ident),
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(Ident::from_str("doc").with_span_pos(span)),
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 find_by_name<'a>(attrs: &'a [Attribute], name: &str) -> Option<&'a Attribute> {
476 attrs.iter().find(|attr| attr.check_name(name))
479 pub fn first_attr_value_str_by_name(attrs: &[Attribute], name: &str) -> Option<Symbol> {
481 .find(|at| at.check_name(name))
482 .and_then(|at| at.value_str())
485 /// Check if `attrs` contains an attribute like `#![feature(feature_name)]`.
486 /// This will not perform any "sanity checks" on the form of the attributes.
487 pub fn contains_feature_attr(attrs: &[Attribute], feature_name: &str) -> bool {
488 attrs.iter().any(|item| {
489 item.check_name("feature") &&
490 item.meta_item_list().map(|list| {
491 list.iter().any(|mi| {
492 mi.word().map(|w| w.ident.name == feature_name)
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 #[derive(Copy, Clone, Hash, PartialEq, RustcEncodable, RustcDecodable)]
506 pub enum InlineAttr {
513 #[derive(Copy, Clone, PartialEq)]
514 pub enum UnwindAttr {
519 /// Determine what `#[unwind]` attribute is present in `attrs`, if any.
520 pub fn find_unwind_attr(diagnostic: Option<&Handler>, attrs: &[Attribute]) -> Option<UnwindAttr> {
521 let syntax_error = |attr: &Attribute| {
524 span_err!(d, attr.span, E0633, "malformed `#[unwind]` attribute");
529 attrs.iter().fold(None, |ia, attr| {
530 if attr.path != "unwind" {
533 let meta = match attr.meta() {
534 Some(meta) => meta.node,
538 MetaItemKind::Word => {
541 MetaItemKind::List(ref items) => {
543 if items.len() != 1 {
545 } else if list_contains_name(&items[..], "allowed") {
546 Some(UnwindAttr::Allowed)
547 } else if list_contains_name(&items[..], "aborts") {
548 Some(UnwindAttr::Aborts)
559 /// Tests if a cfg-pattern matches the cfg set
560 pub fn cfg_matches(cfg: &ast::MetaItem, sess: &ParseSess, features: Option<&Features>) -> bool {
561 eval_condition(cfg, sess, &mut |cfg| {
562 if let (Some(feats), Some(gated_cfg)) = (features, GatedCfg::gate(cfg)) {
563 gated_cfg.check_and_emit(sess, feats);
565 sess.config.contains(&(cfg.ident.name, cfg.value_str()))
569 /// Evaluate a cfg-like condition (with `any` and `all`), using `eval` to
570 /// evaluate individual items.
571 pub fn eval_condition<F>(cfg: &ast::MetaItem, sess: &ParseSess, eval: &mut F)
573 where F: FnMut(&ast::MetaItem) -> bool
576 ast::MetaItemKind::List(ref mis) => {
577 for mi in mis.iter() {
578 if !mi.is_meta_item() {
579 handle_errors(&sess.span_diagnostic, mi.span, AttrError::UnsupportedLiteral);
584 // The unwraps below may look dangerous, but we've already asserted
585 // that they won't fail with the loop above.
586 match &*cfg.ident.name.as_str() {
587 "any" => mis.iter().any(|mi| {
588 eval_condition(mi.meta_item().unwrap(), sess, eval)
590 "all" => mis.iter().all(|mi| {
591 eval_condition(mi.meta_item().unwrap(), sess, eval)
595 span_err!(sess.span_diagnostic, cfg.span, E0536, "expected 1 cfg-pattern");
599 !eval_condition(mis[0].meta_item().unwrap(), sess, eval)
602 span_err!(sess.span_diagnostic, cfg.span, E0537, "invalid predicate `{}`", p);
607 ast::MetaItemKind::Word | ast::MetaItemKind::NameValue(..) => {
613 /// Represents the #[stable], #[unstable], #[rustc_{deprecated,const_unstable}] attributes.
614 #[derive(RustcEncodable, RustcDecodable, Clone, Debug, PartialEq, Eq, Hash)]
615 pub struct Stability {
616 pub level: StabilityLevel,
618 pub rustc_depr: Option<RustcDeprecation>,
619 pub rustc_const_unstable: Option<RustcConstUnstable>,
622 /// The available stability levels.
623 #[derive(RustcEncodable, RustcDecodable, PartialEq, PartialOrd, Clone, Debug, Eq, Hash)]
624 pub enum StabilityLevel {
625 // Reason for the current stability level and the relevant rust-lang issue
626 Unstable { reason: Option<Symbol>, issue: u32 },
627 Stable { since: Symbol },
630 #[derive(RustcEncodable, RustcDecodable, PartialEq, PartialOrd, Clone, Debug, Eq, Hash)]
631 pub struct RustcDeprecation {
636 #[derive(RustcEncodable, RustcDecodable, PartialEq, PartialOrd, Clone, Debug, Eq, Hash)]
637 pub struct RustcConstUnstable {
641 #[derive(RustcEncodable, RustcDecodable, PartialEq, PartialOrd, Clone, Debug, Eq, Hash)]
642 pub struct Deprecation {
643 pub since: Option<Symbol>,
644 pub note: Option<Symbol>,
647 impl StabilityLevel {
648 pub fn is_unstable(&self) -> bool { if let Unstable {..} = *self { true } else { false }}
649 pub fn is_stable(&self) -> bool { if let Stable {..} = *self { true } else { false }}
652 fn find_stability_generic<'a, I>(diagnostic: &Handler,
656 where I: Iterator<Item = &'a Attribute>
658 let mut stab: Option<Stability> = None;
659 let mut rustc_depr: Option<RustcDeprecation> = None;
660 let mut rustc_const_unstable: Option<RustcConstUnstable> = None;
662 'outer: for attr in attrs_iter {
665 "rustc_const_unstable",
668 ].iter().any(|&s| attr.path == s) {
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.ident.name));
682 if let Some(v) = meta.value_str() {
686 span_err!(diagnostic, meta.span, E0539, "incorrect meta item");
691 macro_rules! get_meta {
692 ($($name:ident),+) => {
694 let mut $name = None;
697 if let Some(mi) = meta.meta_item() {
698 match &*mi.ident.name.as_str() {
701 => if !get(mi, &mut $name) { continue 'outer },
704 handle_errors(diagnostic, mi.span,
705 AttrError::UnknownMetaItem(mi.ident.name));
710 handle_errors(diagnostic, meta.span, AttrError::UnsupportedLiteral);
717 match &*meta.ident.name.as_str() {
718 "rustc_deprecated" => {
719 if rustc_depr.is_some() {
720 span_err!(diagnostic, item_sp, E0540,
721 "multiple rustc_deprecated attributes");
725 get_meta!(since, reason);
727 match (since, reason) {
728 (Some(since), Some(reason)) => {
729 rustc_depr = Some(RustcDeprecation {
735 handle_errors(diagnostic, attr.span(), AttrError::MissingSince);
739 span_err!(diagnostic, attr.span(), E0543, "missing 'reason'");
744 "rustc_const_unstable" => {
745 if rustc_const_unstable.is_some() {
746 span_err!(diagnostic, item_sp, E0553,
747 "multiple rustc_const_unstable attributes");
752 if let Some(feature) = feature {
753 rustc_const_unstable = Some(RustcConstUnstable {
757 span_err!(diagnostic, attr.span(), E0629, "missing 'feature'");
763 handle_errors(diagnostic, attr.span(), AttrError::MultipleStabilityLevels);
767 let mut feature = None;
768 let mut reason = None;
769 let mut issue = None;
771 if let Some(mi) = meta.meta_item() {
772 match &*mi.ident.name.as_str() {
773 "feature" => if !get(mi, &mut feature) { continue 'outer },
774 "reason" => if !get(mi, &mut reason) { continue 'outer },
775 "issue" => if !get(mi, &mut issue) { continue 'outer },
777 handle_errors(diagnostic, meta.span,
778 AttrError::UnknownMetaItem(mi.ident.name));
783 handle_errors(diagnostic, meta.span, AttrError::UnsupportedLiteral);
788 match (feature, reason, issue) {
789 (Some(feature), reason, Some(issue)) => {
790 stab = Some(Stability {
794 if let Ok(issue) = issue.as_str().parse() {
797 span_err!(diagnostic, attr.span(), E0545,
798 "incorrect 'issue'");
805 rustc_const_unstable: None,
809 handle_errors(diagnostic, attr.span(), AttrError::MissingFeature);
813 span_err!(diagnostic, attr.span(), E0547, "missing 'issue'");
820 handle_errors(diagnostic, attr.span(), AttrError::MultipleStabilityLevels);
824 let mut feature = None;
825 let mut since = None;
827 if let NestedMetaItemKind::MetaItem(ref mi) = meta.node {
828 match &*mi.ident.name.as_str() {
829 "feature" => if !get(mi, &mut feature) { continue 'outer },
830 "since" => if !get(mi, &mut since) { continue 'outer },
832 handle_errors(diagnostic, meta.span,
833 AttrError::UnknownMetaItem(mi.ident.name));
838 handle_errors(diagnostic, meta.span, AttrError::UnsupportedLiteral);
843 match (feature, since) {
844 (Some(feature), Some(since)) => {
845 stab = Some(Stability {
851 rustc_const_unstable: None,
855 handle_errors(diagnostic, attr.span(), AttrError::MissingFeature);
859 handle_errors(diagnostic, attr.span(), AttrError::MissingSince);
867 span_err!(diagnostic, attr.span(), E0548, "incorrect stability attribute type");
872 // Merge the deprecation info into the stability info
873 if let Some(rustc_depr) = rustc_depr {
874 if let Some(ref mut stab) = stab {
875 stab.rustc_depr = Some(rustc_depr);
877 span_err!(diagnostic, item_sp, E0549,
878 "rustc_deprecated attribute must be paired with \
879 either stable or unstable attribute");
883 // Merge the const-unstable info into the stability info
884 if let Some(rustc_const_unstable) = rustc_const_unstable {
885 if let Some(ref mut stab) = stab {
886 stab.rustc_const_unstable = Some(rustc_const_unstable);
888 span_err!(diagnostic, item_sp, E0630,
889 "rustc_const_unstable attribute must be paired with \
890 either stable or unstable attribute");
897 fn find_deprecation_generic<'a, I>(diagnostic: &Handler,
900 -> Option<Deprecation>
901 where I: Iterator<Item = &'a Attribute>
903 let mut depr: Option<Deprecation> = None;
905 'outer: for attr in attrs_iter {
906 if attr.path != "deprecated" {
913 span_err!(diagnostic, item_sp, E0550, "multiple deprecated attributes");
917 depr = if let Some(metas) = attr.meta_item_list() {
918 let get = |meta: &MetaItem, item: &mut Option<Symbol>| {
920 handle_errors(diagnostic, meta.span, AttrError::MultipleItem(meta.ident.name));
923 if let Some(v) = meta.value_str() {
927 span_err!(diagnostic, meta.span, E0551, "incorrect meta item");
932 let mut since = None;
935 if let NestedMetaItemKind::MetaItem(ref mi) = meta.node {
936 match &*mi.ident.name.as_str() {
937 "since" => if !get(mi, &mut since) { continue 'outer },
938 "note" => if !get(mi, &mut note) { continue 'outer },
940 handle_errors(diagnostic, meta.span,
941 AttrError::UnknownMetaItem(mi.ident.name));
946 handle_errors(diagnostic, meta.span, AttrError::UnsupportedLiteral);
951 Some(Deprecation {since: since, note: note})
953 Some(Deprecation{since: None, note: None})
960 /// Find the first stability attribute. `None` if none exists.
961 pub fn find_stability(diagnostic: &Handler, attrs: &[Attribute],
962 item_sp: Span) -> Option<Stability> {
963 find_stability_generic(diagnostic, attrs.iter(), item_sp)
966 /// Find the deprecation attribute. `None` if none exists.
967 pub fn find_deprecation(diagnostic: &Handler, attrs: &[Attribute],
968 item_sp: Span) -> Option<Deprecation> {
969 find_deprecation_generic(diagnostic, attrs.iter(), item_sp)
973 /// Parse #[repr(...)] forms.
975 /// Valid repr contents: any of the primitive integral type names (see
976 /// `int_type_of_word`, below) to specify enum discriminant type; `C`, to use
977 /// the same discriminant size that the corresponding C enum would or C
978 /// structure layout, `packed` to remove padding, and `transparent` to elegate representation
979 /// concerns to the only non-ZST field.
980 pub fn find_repr_attrs(diagnostic: &Handler, attr: &Attribute) -> Vec<ReprAttr> {
981 let mut acc = Vec::new();
982 if attr.path == "repr" {
983 if let Some(items) = attr.meta_item_list() {
986 if !item.is_meta_item() {
987 handle_errors(diagnostic, item.span, AttrError::UnsupportedLiteral);
991 let mut recognised = false;
992 if let Some(mi) = item.word() {
993 let word = &*mi.ident.name.as_str();
994 let hint = match word {
996 "packed" => Some(ReprPacked),
997 "simd" => Some(ReprSimd),
998 "transparent" => Some(ReprTransparent),
999 _ => match int_type_of_word(word) {
1000 Some(ity) => Some(ReprInt(ity)),
1007 if let Some(h) = hint {
1011 } else if let Some((name, value)) = item.name_value_literal() {
1012 if name == "align" {
1014 let mut align_error = None;
1015 if let ast::LitKind::Int(align, ast::LitIntType::Unsuffixed) = value.node {
1016 if align.is_power_of_two() {
1017 // rustc::ty::layout::Align restricts align to <= 2147483647
1018 if align <= 2147483647 {
1019 acc.push(ReprAlign(align as u32));
1021 align_error = Some("larger than 2147483647");
1024 align_error = Some("not a power of two");
1027 align_error = Some("not an unsuffixed integer");
1029 if let Some(align_error) = align_error {
1030 span_err!(diagnostic, item.span, E0589,
1031 "invalid `repr(align)` attribute: {}", align_error);
1036 // Not a word we recognize
1037 span_err!(diagnostic, item.span, E0552,
1038 "unrecognized representation hint");
1046 fn int_type_of_word(s: &str) -> Option<IntType> {
1048 "i8" => Some(SignedInt(ast::IntTy::I8)),
1049 "u8" => Some(UnsignedInt(ast::UintTy::U8)),
1050 "i16" => Some(SignedInt(ast::IntTy::I16)),
1051 "u16" => Some(UnsignedInt(ast::UintTy::U16)),
1052 "i32" => Some(SignedInt(ast::IntTy::I32)),
1053 "u32" => Some(UnsignedInt(ast::UintTy::U32)),
1054 "i64" => Some(SignedInt(ast::IntTy::I64)),
1055 "u64" => Some(UnsignedInt(ast::UintTy::U64)),
1056 "i128" => Some(SignedInt(ast::IntTy::I128)),
1057 "u128" => Some(UnsignedInt(ast::UintTy::U128)),
1058 "isize" => Some(SignedInt(ast::IntTy::Isize)),
1059 "usize" => Some(UnsignedInt(ast::UintTy::Usize)),
1064 #[derive(PartialEq, Debug, RustcEncodable, RustcDecodable, Copy, Clone)]
1074 #[derive(Eq, Hash, PartialEq, Debug, RustcEncodable, RustcDecodable, Copy, Clone)]
1076 SignedInt(ast::IntTy),
1077 UnsignedInt(ast::UintTy)
1082 pub fn is_signed(self) -> bool {
1084 SignedInt(..) => true,
1085 UnsignedInt(..) => false
1091 fn tokens(&self) -> TokenStream {
1092 let ident = TokenTree::Token(self.span, Token::from_ast_ident(self.ident));
1093 TokenStream::concat(vec![ident.into(), self.node.tokens(self.span)])
1096 fn from_tokens<I>(tokens: &mut iter::Peekable<I>) -> Option<MetaItem>
1097 where I: Iterator<Item = TokenTree>,
1099 let (span, ident) = match tokens.next() {
1100 Some(TokenTree::Token(span, Token::Ident(ident, _))) => (span, ident),
1101 Some(TokenTree::Token(_, Token::Interpolated(ref nt))) => match nt.0 {
1102 token::Nonterminal::NtIdent(ident, _) => (ident.span, ident),
1103 token::Nonterminal::NtMeta(ref meta) => return Some(meta.clone()),
1108 let list_closing_paren_pos = tokens.peek().map(|tt| tt.span().hi());
1109 let node = MetaItemKind::from_tokens(tokens)?;
1110 let hi = match node {
1111 MetaItemKind::NameValue(ref lit) => lit.span.hi(),
1112 MetaItemKind::List(..) => list_closing_paren_pos.unwrap_or(span.hi()),
1115 Some(MetaItem { ident, node, span: span.with_hi(hi) })
1120 pub fn tokens(&self, span: Span) -> TokenStream {
1122 MetaItemKind::Word => TokenStream::empty(),
1123 MetaItemKind::NameValue(ref lit) => {
1124 TokenStream::concat(vec![TokenTree::Token(span, Token::Eq).into(), lit.tokens()])
1126 MetaItemKind::List(ref list) => {
1127 let mut tokens = Vec::new();
1128 for (i, item) in list.iter().enumerate() {
1130 tokens.push(TokenTree::Token(span, Token::Comma).into());
1132 tokens.push(item.node.tokens());
1134 TokenTree::Delimited(span, Delimited {
1135 delim: token::Paren,
1136 tts: TokenStream::concat(tokens).into(),
1142 fn from_tokens<I>(tokens: &mut iter::Peekable<I>) -> Option<MetaItemKind>
1143 where I: Iterator<Item = TokenTree>,
1145 let delimited = match tokens.peek().cloned() {
1146 Some(TokenTree::Token(_, token::Eq)) => {
1148 return if let Some(TokenTree::Token(span, token)) = tokens.next() {
1149 LitKind::from_token(token)
1150 .map(|lit| MetaItemKind::NameValue(Spanned { node: lit, span: span }))
1155 Some(TokenTree::Delimited(_, ref delimited)) if delimited.delim == token::Paren => {
1159 _ => return Some(MetaItemKind::Word),
1162 let mut tokens = delimited.into_trees().peekable();
1163 let mut result = Vec::new();
1164 while let Some(..) = tokens.peek() {
1165 let item = NestedMetaItemKind::from_tokens(&mut tokens)?;
1166 result.push(respan(item.span(), item));
1167 match tokens.next() {
1168 None | Some(TokenTree::Token(_, Token::Comma)) => {}
1172 Some(MetaItemKind::List(result))
1176 impl NestedMetaItemKind {
1177 fn span(&self) -> Span {
1179 NestedMetaItemKind::MetaItem(ref item) => item.span,
1180 NestedMetaItemKind::Literal(ref lit) => lit.span,
1184 fn tokens(&self) -> TokenStream {
1186 NestedMetaItemKind::MetaItem(ref item) => item.tokens(),
1187 NestedMetaItemKind::Literal(ref lit) => lit.tokens(),
1191 fn from_tokens<I>(tokens: &mut iter::Peekable<I>) -> Option<NestedMetaItemKind>
1192 where I: Iterator<Item = TokenTree>,
1194 if let Some(TokenTree::Token(span, token)) = tokens.peek().cloned() {
1195 if let Some(node) = LitKind::from_token(token) {
1197 return Some(NestedMetaItemKind::Literal(respan(span, node)));
1201 MetaItem::from_tokens(tokens).map(NestedMetaItemKind::MetaItem)
1206 fn tokens(&self) -> TokenStream {
1207 TokenTree::Token(self.span, self.node.token()).into()
1212 fn token(&self) -> Token {
1216 LitKind::Str(string, ast::StrStyle::Cooked) => {
1217 let mut escaped = String::new();
1218 for ch in string.as_str().chars() {
1219 escaped.extend(ch.escape_unicode());
1221 Token::Literal(token::Lit::Str_(Symbol::intern(&escaped)), None)
1223 LitKind::Str(string, ast::StrStyle::Raw(n)) => {
1224 Token::Literal(token::Lit::StrRaw(string, n), None)
1226 LitKind::ByteStr(ref bytes) => {
1227 let string = bytes.iter().cloned().flat_map(ascii::escape_default)
1228 .map(Into::<char>::into).collect::<String>();
1229 Token::Literal(token::Lit::ByteStr(Symbol::intern(&string)), None)
1231 LitKind::Byte(byte) => {
1232 let string: String = ascii::escape_default(byte).map(Into::<char>::into).collect();
1233 Token::Literal(token::Lit::Byte(Symbol::intern(&string)), None)
1235 LitKind::Char(ch) => {
1236 let string: String = ch.escape_default().map(Into::<char>::into).collect();
1237 Token::Literal(token::Lit::Char(Symbol::intern(&string)), None)
1239 LitKind::Int(n, ty) => {
1240 let suffix = match ty {
1241 ast::LitIntType::Unsigned(ty) => Some(Symbol::intern(ty.ty_to_string())),
1242 ast::LitIntType::Signed(ty) => Some(Symbol::intern(ty.ty_to_string())),
1243 ast::LitIntType::Unsuffixed => None,
1245 Token::Literal(token::Lit::Integer(Symbol::intern(&n.to_string())), suffix)
1247 LitKind::Float(symbol, ty) => {
1248 Token::Literal(token::Lit::Float(symbol), Some(Symbol::intern(ty.ty_to_string())))
1250 LitKind::FloatUnsuffixed(symbol) => Token::Literal(token::Lit::Float(symbol), None),
1251 LitKind::Bool(value) => Token::Ident(Ident::with_empty_ctxt(Symbol::intern(if value {
1259 fn from_token(token: Token) -> Option<LitKind> {
1261 Token::Ident(ident, false) if ident.name == "true" => Some(LitKind::Bool(true)),
1262 Token::Ident(ident, false) if ident.name == "false" => Some(LitKind::Bool(false)),
1263 Token::Interpolated(ref nt) => match nt.0 {
1264 token::NtExpr(ref v) => match v.node {
1265 ExprKind::Lit(ref lit) => Some(lit.node.clone()),
1270 Token::Literal(lit, suf) => {
1271 let (suffix_illegal, result) = parse::lit_token(lit, suf, None);
1272 if suffix_illegal && suf.is_some() {
1282 pub trait HasAttrs: Sized {
1283 fn attrs(&self) -> &[ast::Attribute];
1284 fn map_attrs<F: FnOnce(Vec<ast::Attribute>) -> Vec<ast::Attribute>>(self, f: F) -> Self;
1287 impl<T: HasAttrs> HasAttrs for Spanned<T> {
1288 fn attrs(&self) -> &[ast::Attribute] { self.node.attrs() }
1289 fn map_attrs<F: FnOnce(Vec<ast::Attribute>) -> Vec<ast::Attribute>>(self, f: F) -> Self {
1290 respan(self.span, self.node.map_attrs(f))
1294 impl HasAttrs for Vec<Attribute> {
1295 fn attrs(&self) -> &[Attribute] {
1298 fn map_attrs<F: FnOnce(Vec<Attribute>) -> Vec<Attribute>>(self, f: F) -> Self {
1303 impl HasAttrs for ThinVec<Attribute> {
1304 fn attrs(&self) -> &[Attribute] {
1307 fn map_attrs<F: FnOnce(Vec<Attribute>) -> Vec<Attribute>>(self, f: F) -> Self {
1308 f(self.into()).into()
1312 impl<T: HasAttrs + 'static> HasAttrs for P<T> {
1313 fn attrs(&self) -> &[Attribute] {
1316 fn map_attrs<F: FnOnce(Vec<Attribute>) -> Vec<Attribute>>(self, f: F) -> Self {
1317 self.map(|t| t.map_attrs(f))
1321 impl HasAttrs for StmtKind {
1322 fn attrs(&self) -> &[Attribute] {
1324 StmtKind::Local(ref local) => local.attrs(),
1325 StmtKind::Item(..) => &[],
1326 StmtKind::Expr(ref expr) | StmtKind::Semi(ref expr) => expr.attrs(),
1327 StmtKind::Mac(ref mac) => {
1328 let (_, _, ref attrs) = **mac;
1334 fn map_attrs<F: FnOnce(Vec<Attribute>) -> Vec<Attribute>>(self, f: F) -> Self {
1336 StmtKind::Local(local) => StmtKind::Local(local.map_attrs(f)),
1337 StmtKind::Item(..) => self,
1338 StmtKind::Expr(expr) => StmtKind::Expr(expr.map_attrs(f)),
1339 StmtKind::Semi(expr) => StmtKind::Semi(expr.map_attrs(f)),
1340 StmtKind::Mac(mac) => StmtKind::Mac(mac.map(|(mac, style, attrs)| {
1341 (mac, style, attrs.map_attrs(f))
1347 impl HasAttrs for Stmt {
1348 fn attrs(&self) -> &[ast::Attribute] { self.node.attrs() }
1349 fn map_attrs<F: FnOnce(Vec<ast::Attribute>) -> Vec<ast::Attribute>>(self, f: F) -> Self {
1350 Stmt { id: self.id, node: self.node.map_attrs(f), span: self.span }
1354 macro_rules! derive_has_attrs {
1355 ($($ty:path),*) => { $(
1356 impl HasAttrs for $ty {
1357 fn attrs(&self) -> &[Attribute] {
1361 fn map_attrs<F>(mut self, f: F) -> Self
1362 where F: FnOnce(Vec<Attribute>) -> Vec<Attribute>,
1364 self.attrs = self.attrs.map_attrs(f);
1372 Item, Expr, Local, ast::ForeignItem, ast::StructField, ast::ImplItem, ast::TraitItem, ast::Arm,
1373 ast::Field, ast::FieldPat, ast::Variant_