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 const RUST_KNOWN_TOOL: &[&str] = &["clippy", "rustfmt"];
112 pub fn is_known_tool(attr: &Attribute) -> bool {
114 attr.path.segments.iter().next().expect("empty path in attribute").identifier.name;
115 RUST_KNOWN_TOOL.contains(&tool_name.as_str().as_ref())
118 impl NestedMetaItem {
119 /// Returns the MetaItem if self is a NestedMetaItemKind::MetaItem.
120 pub fn meta_item(&self) -> Option<&MetaItem> {
122 NestedMetaItemKind::MetaItem(ref item) => Some(item),
127 /// Returns the Lit if self is a NestedMetaItemKind::Literal.
128 pub fn literal(&self) -> Option<&Lit> {
130 NestedMetaItemKind::Literal(ref lit) => Some(lit),
135 /// Returns the Span for `self`.
136 pub fn span(&self) -> Span {
140 /// Returns true if this list item is a MetaItem with a name of `name`.
141 pub fn check_name(&self, name: &str) -> bool {
142 self.meta_item().map_or(false, |meta_item| meta_item.check_name(name))
145 /// Returns the name of the meta item, e.g. `foo` in `#[foo]`,
146 /// `#[foo="bar"]` and `#[foo(bar)]`, if self is a MetaItem
147 pub fn name(&self) -> Option<Name> {
148 self.meta_item().and_then(|meta_item| Some(meta_item.name()))
151 /// Gets the string value if self is a MetaItem and the MetaItem is a
152 /// MetaItemKind::NameValue variant containing a string, otherwise None.
153 pub fn value_str(&self) -> Option<Symbol> {
154 self.meta_item().and_then(|meta_item| meta_item.value_str())
157 /// Returns a name and single literal value tuple of the MetaItem.
158 pub fn name_value_literal(&self) -> Option<(Name, &Lit)> {
159 self.meta_item().and_then(
160 |meta_item| meta_item.meta_item_list().and_then(
162 if meta_item_list.len() == 1 {
163 let nested_item = &meta_item_list[0];
164 if nested_item.is_literal() {
165 Some((meta_item.name(), nested_item.literal().unwrap()))
175 /// Returns a MetaItem if self is a MetaItem with Kind Word.
176 pub fn word(&self) -> Option<&MetaItem> {
177 self.meta_item().and_then(|meta_item| if meta_item.is_word() {
184 /// Gets a list of inner meta items from a list MetaItem type.
185 pub fn meta_item_list(&self) -> Option<&[NestedMetaItem]> {
186 self.meta_item().and_then(|meta_item| meta_item.meta_item_list())
189 /// Returns `true` if the variant is MetaItem.
190 pub fn is_meta_item(&self) -> bool {
191 self.meta_item().is_some()
194 /// Returns `true` if the variant is Literal.
195 pub fn is_literal(&self) -> bool {
196 self.literal().is_some()
199 /// Returns `true` if self is a MetaItem and the meta item is a word.
200 pub fn is_word(&self) -> bool {
201 self.word().is_some()
204 /// Returns `true` if self is a MetaItem and the meta item is a ValueString.
205 pub fn is_value_str(&self) -> bool {
206 self.value_str().is_some()
209 /// Returns `true` if self is a MetaItem and the meta item is a list.
210 pub fn is_meta_item_list(&self) -> bool {
211 self.meta_item_list().is_some()
215 fn name_from_path(path: &ast::Path) -> Name {
216 path.segments.last().expect("empty path in attribute").identifier.name
220 pub fn check_name(&self, name: &str) -> bool {
221 let matches = self.path == name;
228 /// Returns the **last** segment of the name of this attribute.
229 /// E.g. `foo` for `#[foo]`, `skip` for `#[rustfmt::skip]`.
230 pub fn name(&self) -> Name {
231 name_from_path(&self.path)
234 pub fn value_str(&self) -> Option<Symbol> {
235 self.meta().and_then(|meta| meta.value_str())
238 pub fn meta_item_list(&self) -> Option<Vec<NestedMetaItem>> {
240 Some(MetaItem { node: MetaItemKind::List(list), .. }) => Some(list),
245 pub fn is_word(&self) -> bool {
246 self.path.segments.len() == 1 && self.tokens.is_empty()
249 pub fn span(&self) -> Span {
253 pub fn is_meta_item_list(&self) -> bool {
254 self.meta_item_list().is_some()
257 /// Indicates if the attribute is a Value String.
258 pub fn is_value_str(&self) -> bool {
259 self.value_str().is_some()
262 pub fn is_scoped(&self) -> bool {
263 self.path.segments.len() > 1
268 pub fn name(&self) -> Name {
269 name_from_path(&self.name)
272 pub fn value_str(&self) -> Option<Symbol> {
274 MetaItemKind::NameValue(ref v) => {
276 LitKind::Str(ref s, _) => Some(*s),
284 pub fn meta_item_list(&self) -> Option<&[NestedMetaItem]> {
286 MetaItemKind::List(ref l) => Some(&l[..]),
291 pub fn is_word(&self) -> bool {
293 MetaItemKind::Word => true,
298 pub fn span(&self) -> Span { self.span }
300 pub fn check_name(&self, name: &str) -> bool {
304 pub fn is_value_str(&self) -> bool {
305 self.value_str().is_some()
308 pub fn is_meta_item_list(&self) -> bool {
309 self.meta_item_list().is_some()
314 /// Extract the MetaItem from inside this Attribute.
315 pub fn meta(&self) -> Option<MetaItem> {
316 let mut tokens = self.tokens.trees().peekable();
318 name: self.path.clone(),
319 node: if let Some(node) = MetaItemKind::from_tokens(&mut tokens) {
320 if tokens.peek().is_some() {
331 pub fn parse<'a, T, F>(&self, sess: &'a ParseSess, mut f: F) -> PResult<'a, T>
332 where F: FnMut(&mut Parser<'a>) -> PResult<'a, T>,
334 let mut parser = Parser::new(sess, self.tokens.clone(), None, false, false);
335 let result = f(&mut parser)?;
336 if parser.token != token::Eof {
337 parser.unexpected()?;
342 pub fn parse_list<'a, T, F>(&self, sess: &'a ParseSess, mut f: F) -> PResult<'a, Vec<T>>
343 where F: FnMut(&mut Parser<'a>) -> PResult<'a, T>,
345 if self.tokens.is_empty() {
346 return Ok(Vec::new());
348 self.parse(sess, |parser| {
349 parser.expect(&token::OpenDelim(token::Paren))?;
350 let mut list = Vec::new();
351 while !parser.eat(&token::CloseDelim(token::Paren)) {
352 list.push(f(parser)?);
353 if !parser.eat(&token::Comma) {
354 parser.expect(&token::CloseDelim(token::Paren))?;
362 pub fn parse_meta<'a>(&self, sess: &'a ParseSess) -> PResult<'a, MetaItem> {
364 name: self.path.clone(),
365 node: self.parse(sess, |parser| parser.parse_meta_item_kind())?,
370 /// Convert self to a normal #[doc="foo"] comment, if it is a
371 /// comment like `///` or `/** */`. (Returns self unchanged for
372 /// non-sugared doc attributes.)
373 pub fn with_desugared_doc<T, F>(&self, f: F) -> T where
374 F: FnOnce(&Attribute) -> T,
376 if self.is_sugared_doc {
377 let comment = self.value_str().unwrap();
378 let meta = mk_name_value_item_str(
379 Ident::from_str("doc"),
380 dummy_spanned(Symbol::intern(&strip_doc_comment_decoration(&comment.as_str()))));
381 let mut attr = if self.style == ast::AttrStyle::Outer {
382 mk_attr_outer(self.span, self.id, meta)
384 mk_attr_inner(self.span, self.id, meta)
386 attr.is_sugared_doc = true;
396 pub fn mk_name_value_item_str(ident: Ident, value: Spanned<Symbol>) -> MetaItem {
397 let value = respan(value.span, LitKind::Str(value.node, ast::StrStyle::Cooked));
398 mk_name_value_item(ident.span.to(value.span), ident, value)
401 pub fn mk_name_value_item(span: Span, ident: Ident, value: ast::Lit) -> MetaItem {
402 MetaItem { ident, span, node: MetaItemKind::NameValue(value) }
405 pub fn mk_list_item(span: Span, ident: Ident, items: Vec<NestedMetaItem>) -> MetaItem {
406 MetaItem { ident, span, node: MetaItemKind::List(items) }
409 pub fn mk_word_item(ident: Ident) -> MetaItem {
410 MetaItem { ident, span: ident.span, node: MetaItemKind::Word }
413 pub fn mk_word_item(name: Name) -> MetaItem {
414 mk_spanned_word_item(DUMMY_SP, name)
417 macro_rules! mk_spanned_meta_item {
418 ($sp:ident, $name:ident, $node:expr) => {
421 name: ast::Path::from_ident($sp, ast::Ident::with_empty_ctxt($name)),
427 pub fn mk_spanned_name_value_item(sp: Span, name: Name, value: ast::Lit) -> MetaItem {
428 mk_spanned_meta_item!(sp, name, MetaItemKind::NameValue(value))
431 pub fn mk_spanned_list_item(sp: Span, name: Name, items: Vec<NestedMetaItem>) -> MetaItem {
432 mk_spanned_meta_item!(sp, name, MetaItemKind::List(items))
435 pub fn mk_spanned_word_item(sp: Span, name: Name) -> MetaItem {
436 mk_spanned_meta_item!(sp, name, MetaItemKind::Word)
439 pub fn mk_attr_id() -> AttrId {
440 use std::sync::atomic::AtomicUsize;
441 use std::sync::atomic::Ordering;
443 static NEXT_ATTR_ID: AtomicUsize = AtomicUsize::new(0);
445 let id = NEXT_ATTR_ID.fetch_add(1, Ordering::SeqCst);
446 assert!(id != ::std::usize::MAX);
450 /// Returns an inner attribute with the given value.
451 pub fn mk_attr_inner(span: Span, id: AttrId, item: MetaItem) -> Attribute {
452 mk_spanned_attr_inner(span, id, item)
455 /// Returns an inner attribute with the given value and span.
456 pub fn mk_spanned_attr_inner(sp: Span, id: AttrId, item: MetaItem) -> Attribute {
459 style: ast::AttrStyle::Inner,
461 tokens: item.node.tokens(item.span),
462 is_sugared_doc: false,
468 /// Returns an outer attribute with the given value.
469 pub fn mk_attr_outer(span: Span, id: AttrId, item: MetaItem) -> Attribute {
470 mk_spanned_attr_outer(span, id, item)
473 /// Returns an outer attribute with the given value and span.
474 pub fn mk_spanned_attr_outer(sp: Span, id: AttrId, item: MetaItem) -> Attribute {
477 style: ast::AttrStyle::Outer,
479 tokens: item.node.tokens(item.span),
480 is_sugared_doc: false,
485 pub fn mk_sugared_doc_attr(id: AttrId, text: Symbol, span: Span) -> Attribute {
486 let style = doc_comment_style(&text.as_str());
487 let lit = respan(span, LitKind::Str(text, ast::StrStyle::Cooked));
491 path: ast::Path::from_ident(Ident::from_str("doc").with_span_pos(span)),
492 tokens: MetaItemKind::NameValue(lit).tokens(span),
493 is_sugared_doc: true,
498 pub fn list_contains_name(items: &[NestedMetaItem], name: &str) -> bool {
499 items.iter().any(|item| {
500 item.check_name(name)
504 pub fn contains_name(attrs: &[Attribute], name: &str) -> bool {
505 attrs.iter().any(|item| {
506 item.check_name(name)
510 pub fn find_by_name<'a>(attrs: &'a [Attribute], name: &str) -> Option<&'a Attribute> {
511 attrs.iter().find(|attr| attr.check_name(name))
514 pub fn first_attr_value_str_by_name(attrs: &[Attribute], name: &str) -> Option<Symbol> {
516 .find(|at| at.check_name(name))
517 .and_then(|at| at.value_str())
520 /// Check if `attrs` contains an attribute like `#![feature(feature_name)]`.
521 /// This will not perform any "sanity checks" on the form of the attributes.
522 pub fn contains_feature_attr(attrs: &[Attribute], feature_name: &str) -> bool {
523 attrs.iter().any(|item| {
524 item.check_name("feature") &&
525 item.meta_item_list().map(|list| {
526 list.iter().any(|mi| {
527 mi.word().map(|w| w.name() == feature_name)
534 /* Higher-level applications */
536 pub fn find_crate_name(attrs: &[Attribute]) -> Option<Symbol> {
537 first_attr_value_str_by_name(attrs, "crate_name")
540 #[derive(Copy, Clone, Hash, PartialEq, RustcEncodable, RustcDecodable)]
541 pub enum InlineAttr {
548 #[derive(Copy, Clone, PartialEq)]
549 pub enum UnwindAttr {
554 /// Determine what `#[unwind]` attribute is present in `attrs`, if any.
555 pub fn find_unwind_attr(diagnostic: Option<&Handler>, attrs: &[Attribute]) -> Option<UnwindAttr> {
556 let syntax_error = |attr: &Attribute| {
559 span_err!(d, attr.span, E0633, "malformed `#[unwind]` attribute");
564 attrs.iter().fold(None, |ia, attr| {
565 if attr.path != "unwind" {
568 let meta = match attr.meta() {
569 Some(meta) => meta.node,
573 MetaItemKind::Word => {
576 MetaItemKind::List(ref items) => {
578 if items.len() != 1 {
580 } else if list_contains_name(&items[..], "allowed") {
581 Some(UnwindAttr::Allowed)
582 } else if list_contains_name(&items[..], "aborts") {
583 Some(UnwindAttr::Aborts)
594 /// Tests if a cfg-pattern matches the cfg set
595 pub fn cfg_matches(cfg: &ast::MetaItem, sess: &ParseSess, features: Option<&Features>) -> bool {
596 eval_condition(cfg, sess, &mut |cfg| {
597 if let (Some(feats), Some(gated_cfg)) = (features, GatedCfg::gate(cfg)) {
598 gated_cfg.check_and_emit(sess, feats);
600 sess.config.contains(&(cfg.name(), cfg.value_str()))
604 /// Evaluate a cfg-like condition (with `any` and `all`), using `eval` to
605 /// evaluate individual items.
606 pub fn eval_condition<F>(cfg: &ast::MetaItem, sess: &ParseSess, eval: &mut F)
608 where F: FnMut(&ast::MetaItem) -> bool
611 ast::MetaItemKind::List(ref mis) => {
612 for mi in mis.iter() {
613 if !mi.is_meta_item() {
614 handle_errors(&sess.span_diagnostic, mi.span, AttrError::UnsupportedLiteral);
619 // The unwraps below may look dangerous, but we've already asserted
620 // that they won't fail with the loop above.
621 match &*cfg.name().as_str() {
622 "any" => mis.iter().any(|mi| {
623 eval_condition(mi.meta_item().unwrap(), sess, eval)
625 "all" => mis.iter().all(|mi| {
626 eval_condition(mi.meta_item().unwrap(), sess, eval)
630 span_err!(sess.span_diagnostic, cfg.span, E0536, "expected 1 cfg-pattern");
634 !eval_condition(mis[0].meta_item().unwrap(), sess, eval)
637 span_err!(sess.span_diagnostic, cfg.span, E0537, "invalid predicate `{}`", p);
642 ast::MetaItemKind::Word | ast::MetaItemKind::NameValue(..) => {
648 /// Represents the #[stable], #[unstable], #[rustc_{deprecated,const_unstable}] attributes.
649 #[derive(RustcEncodable, RustcDecodable, Clone, Debug, PartialEq, Eq, Hash)]
650 pub struct Stability {
651 pub level: StabilityLevel,
653 pub rustc_depr: Option<RustcDeprecation>,
654 pub rustc_const_unstable: Option<RustcConstUnstable>,
657 /// The available stability levels.
658 #[derive(RustcEncodable, RustcDecodable, PartialEq, PartialOrd, Clone, Debug, Eq, Hash)]
659 pub enum StabilityLevel {
660 // Reason for the current stability level and the relevant rust-lang issue
661 Unstable { reason: Option<Symbol>, issue: u32 },
662 Stable { since: Symbol },
665 #[derive(RustcEncodable, RustcDecodable, PartialEq, PartialOrd, Clone, Debug, Eq, Hash)]
666 pub struct RustcDeprecation {
671 #[derive(RustcEncodable, RustcDecodable, PartialEq, PartialOrd, Clone, Debug, Eq, Hash)]
672 pub struct RustcConstUnstable {
676 #[derive(RustcEncodable, RustcDecodable, PartialEq, PartialOrd, Clone, Debug, Eq, Hash)]
677 pub struct Deprecation {
678 pub since: Option<Symbol>,
679 pub note: Option<Symbol>,
682 impl StabilityLevel {
683 pub fn is_unstable(&self) -> bool { if let Unstable {..} = *self { true } else { false }}
684 pub fn is_stable(&self) -> bool { if let Stable {..} = *self { true } else { false }}
687 fn find_stability_generic<'a, I>(diagnostic: &Handler,
691 where I: Iterator<Item = &'a Attribute>
693 let mut stab: Option<Stability> = None;
694 let mut rustc_depr: Option<RustcDeprecation> = None;
695 let mut rustc_const_unstable: Option<RustcConstUnstable> = None;
697 'outer: for attr in attrs_iter {
700 "rustc_const_unstable",
703 ].iter().any(|&s| attr.path == s) {
704 continue // not a stability level
709 let meta = attr.meta();
710 if let Some(MetaItem { node: MetaItemKind::List(ref metas), .. }) = meta {
711 let meta = meta.as_ref().unwrap();
712 let get = |meta: &MetaItem, item: &mut Option<Symbol>| {
714 handle_errors(diagnostic, meta.span, AttrError::MultipleItem(meta.name()));
717 if let Some(v) = meta.value_str() {
721 span_err!(diagnostic, meta.span, E0539, "incorrect meta item");
726 macro_rules! get_meta {
727 ($($name:ident),+) => {
729 let mut $name = None;
732 if let Some(mi) = meta.meta_item() {
733 match &*mi.name().as_str() {
736 => if !get(mi, &mut $name) { continue 'outer },
739 handle_errors(diagnostic, mi.span,
740 AttrError::UnknownMetaItem(mi.name()));
745 handle_errors(diagnostic, meta.span, AttrError::UnsupportedLiteral);
752 match &*meta.name().as_str() {
753 "rustc_deprecated" => {
754 if rustc_depr.is_some() {
755 span_err!(diagnostic, item_sp, E0540,
756 "multiple rustc_deprecated attributes");
760 get_meta!(since, reason);
762 match (since, reason) {
763 (Some(since), Some(reason)) => {
764 rustc_depr = Some(RustcDeprecation {
770 handle_errors(diagnostic, attr.span(), AttrError::MissingSince);
774 span_err!(diagnostic, attr.span(), E0543, "missing 'reason'");
779 "rustc_const_unstable" => {
780 if rustc_const_unstable.is_some() {
781 span_err!(diagnostic, item_sp, E0553,
782 "multiple rustc_const_unstable attributes");
787 if let Some(feature) = feature {
788 rustc_const_unstable = Some(RustcConstUnstable {
792 span_err!(diagnostic, attr.span(), E0629, "missing 'feature'");
798 handle_errors(diagnostic, attr.span(), AttrError::MultipleStabilityLevels);
802 let mut feature = None;
803 let mut reason = None;
804 let mut issue = None;
806 if let Some(mi) = meta.meta_item() {
807 match &*mi.name().as_str() {
808 "feature" => if !get(mi, &mut feature) { continue 'outer },
809 "reason" => if !get(mi, &mut reason) { continue 'outer },
810 "issue" => if !get(mi, &mut issue) { continue 'outer },
812 handle_errors(diagnostic, meta.span,
813 AttrError::UnknownMetaItem(mi.name()));
818 handle_errors(diagnostic, meta.span, AttrError::UnsupportedLiteral);
823 match (feature, reason, issue) {
824 (Some(feature), reason, Some(issue)) => {
825 stab = Some(Stability {
829 if let Ok(issue) = issue.as_str().parse() {
832 span_err!(diagnostic, attr.span(), E0545,
833 "incorrect 'issue'");
840 rustc_const_unstable: None,
844 handle_errors(diagnostic, attr.span(), AttrError::MissingFeature);
848 span_err!(diagnostic, attr.span(), E0547, "missing 'issue'");
855 handle_errors(diagnostic, attr.span(), AttrError::MultipleStabilityLevels);
859 let mut feature = None;
860 let mut since = None;
862 if let NestedMetaItemKind::MetaItem(ref mi) = meta.node {
863 match &*mi.name().as_str() {
864 "feature" => if !get(mi, &mut feature) { continue 'outer },
865 "since" => if !get(mi, &mut since) { continue 'outer },
867 handle_errors(diagnostic, meta.span,
868 AttrError::UnknownMetaItem(mi.name()));
873 handle_errors(diagnostic, meta.span, AttrError::UnsupportedLiteral);
878 match (feature, since) {
879 (Some(feature), Some(since)) => {
880 stab = Some(Stability {
886 rustc_const_unstable: None,
890 handle_errors(diagnostic, attr.span(), AttrError::MissingFeature);
894 handle_errors(diagnostic, attr.span(), AttrError::MissingSince);
902 span_err!(diagnostic, attr.span(), E0548, "incorrect stability attribute type");
907 // Merge the deprecation info into the stability info
908 if let Some(rustc_depr) = rustc_depr {
909 if let Some(ref mut stab) = stab {
910 stab.rustc_depr = Some(rustc_depr);
912 span_err!(diagnostic, item_sp, E0549,
913 "rustc_deprecated attribute must be paired with \
914 either stable or unstable attribute");
918 // Merge the const-unstable info into the stability info
919 if let Some(rustc_const_unstable) = rustc_const_unstable {
920 if let Some(ref mut stab) = stab {
921 stab.rustc_const_unstable = Some(rustc_const_unstable);
923 span_err!(diagnostic, item_sp, E0630,
924 "rustc_const_unstable attribute must be paired with \
925 either stable or unstable attribute");
932 fn find_deprecation_generic<'a, I>(diagnostic: &Handler,
935 -> Option<Deprecation>
936 where I: Iterator<Item = &'a Attribute>
938 let mut depr: Option<Deprecation> = None;
940 'outer: for attr in attrs_iter {
941 if attr.path != "deprecated" {
948 span_err!(diagnostic, item_sp, E0550, "multiple deprecated attributes");
952 depr = if let Some(metas) = attr.meta_item_list() {
953 let get = |meta: &MetaItem, item: &mut Option<Symbol>| {
955 handle_errors(diagnostic, meta.span, AttrError::MultipleItem(meta.name()));
958 if let Some(v) = meta.value_str() {
962 span_err!(diagnostic, meta.span, E0551, "incorrect meta item");
967 let mut since = None;
970 if let NestedMetaItemKind::MetaItem(ref mi) = meta.node {
971 match &*mi.name().as_str() {
972 "since" => if !get(mi, &mut since) { continue 'outer },
973 "note" => if !get(mi, &mut note) { continue 'outer },
975 handle_errors(diagnostic, meta.span,
976 AttrError::UnknownMetaItem(mi.name()));
981 handle_errors(diagnostic, meta.span, AttrError::UnsupportedLiteral);
986 Some(Deprecation {since: since, note: note})
988 Some(Deprecation{since: None, note: None})
995 /// Find the first stability attribute. `None` if none exists.
996 pub fn find_stability(diagnostic: &Handler, attrs: &[Attribute],
997 item_sp: Span) -> Option<Stability> {
998 find_stability_generic(diagnostic, attrs.iter(), item_sp)
1001 /// Find the deprecation attribute. `None` if none exists.
1002 pub fn find_deprecation(diagnostic: &Handler, attrs: &[Attribute],
1003 item_sp: Span) -> Option<Deprecation> {
1004 find_deprecation_generic(diagnostic, attrs.iter(), item_sp)
1008 /// Parse #[repr(...)] forms.
1010 /// Valid repr contents: any of the primitive integral type names (see
1011 /// `int_type_of_word`, below) to specify enum discriminant type; `C`, to use
1012 /// the same discriminant size that the corresponding C enum would or C
1013 /// structure layout, `packed` to remove padding, and `transparent` to elegate representation
1014 /// concerns to the only non-ZST field.
1015 pub fn find_repr_attrs(diagnostic: &Handler, attr: &Attribute) -> Vec<ReprAttr> {
1016 let mut acc = Vec::new();
1017 if attr.path == "repr" {
1018 if let Some(items) = attr.meta_item_list() {
1021 if !item.is_meta_item() {
1022 handle_errors(diagnostic, item.span, AttrError::UnsupportedLiteral);
1026 let mut recognised = false;
1027 if let Some(mi) = item.word() {
1028 let word = &*mi.name().as_str();
1029 let hint = match word {
1031 "packed" => Some(ReprPacked(1)),
1032 "simd" => Some(ReprSimd),
1033 "transparent" => Some(ReprTransparent),
1034 _ => match int_type_of_word(word) {
1035 Some(ity) => Some(ReprInt(ity)),
1042 if let Some(h) = hint {
1046 } else if let Some((name, value)) = item.name_value_literal() {
1047 let parse_alignment = |node: &ast::LitKind| -> Result<u32, &'static str> {
1048 if let ast::LitKind::Int(literal, ast::LitIntType::Unsuffixed) = node {
1049 if literal.is_power_of_two() {
1050 // rustc::ty::layout::Align restricts align to <= 2147483647
1051 if *literal <= 2147483647 {
1054 Err("larger than 2147483647")
1057 Err("not a power of two")
1060 Err("not an unsuffixed integer")
1064 let mut literal_error = None;
1065 if name == "align" {
1067 match parse_alignment(&value.node) {
1068 Ok(literal) => acc.push(ReprAlign(literal)),
1069 Err(message) => literal_error = Some(message)
1072 else if name == "packed" {
1074 match parse_alignment(&value.node) {
1075 Ok(literal) => acc.push(ReprPacked(literal)),
1076 Err(message) => literal_error = Some(message)
1079 if let Some(literal_error) = literal_error {
1080 span_err!(diagnostic, item.span, E0589,
1081 "invalid `repr(align)` attribute: {}", literal_error);
1084 if let Some(meta_item) = item.meta_item() {
1085 if meta_item.ident.name == "align" {
1086 if let MetaItemKind::NameValue(ref value) = meta_item.node {
1088 let mut err = struct_span_err!(diagnostic, item.span, E0693,
1089 "incorrect `repr(align)` attribute format");
1091 ast::LitKind::Int(int, ast::LitIntType::Unsuffixed) => {
1092 err.span_suggestion(item.span,
1093 "use parentheses instead",
1094 format!("align({})", int));
1096 ast::LitKind::Str(s, _) => {
1097 err.span_suggestion(item.span,
1098 "use parentheses instead",
1099 format!("align({})", s));
1109 // Not a word we recognize
1110 span_err!(diagnostic, item.span, E0552,
1111 "unrecognized representation hint");
1119 fn int_type_of_word(s: &str) -> Option<IntType> {
1121 "i8" => Some(SignedInt(ast::IntTy::I8)),
1122 "u8" => Some(UnsignedInt(ast::UintTy::U8)),
1123 "i16" => Some(SignedInt(ast::IntTy::I16)),
1124 "u16" => Some(UnsignedInt(ast::UintTy::U16)),
1125 "i32" => Some(SignedInt(ast::IntTy::I32)),
1126 "u32" => Some(UnsignedInt(ast::UintTy::U32)),
1127 "i64" => Some(SignedInt(ast::IntTy::I64)),
1128 "u64" => Some(UnsignedInt(ast::UintTy::U64)),
1129 "i128" => Some(SignedInt(ast::IntTy::I128)),
1130 "u128" => Some(UnsignedInt(ast::UintTy::U128)),
1131 "isize" => Some(SignedInt(ast::IntTy::Isize)),
1132 "usize" => Some(UnsignedInt(ast::UintTy::Usize)),
1137 #[derive(PartialEq, Debug, RustcEncodable, RustcDecodable, Copy, Clone)]
1147 #[derive(Eq, Hash, PartialEq, Debug, RustcEncodable, RustcDecodable, Copy, Clone)]
1149 SignedInt(ast::IntTy),
1150 UnsignedInt(ast::UintTy)
1155 pub fn is_signed(self) -> bool {
1157 SignedInt(..) => true,
1158 UnsignedInt(..) => false
1164 fn tokens(&self) -> TokenStream {
1165 let mut idents = vec![];
1166 let mut last_pos = BytePos(0 as u32);
1167 // FIXME: Share code with `parse_path`.
1168 for (i, segment) in self.name.segments.iter().enumerate() {
1169 let is_first = i == 0;
1171 let mod_sep_span = Span::new(last_pos, segment.span.lo(), segment.span.ctxt());
1172 idents.push(TokenTree::Token(mod_sep_span, Token::ModSep).into());
1174 idents.push(TokenTree::Token(segment.span, Token::Ident(segment.identifier)).into());
1175 last_pos = segment.span.hi();
1177 idents.push(self.node.tokens(self.span));
1178 TokenStream::concat(idents)
1181 fn from_tokens<I>(tokens: &mut iter::Peekable<I>) -> Option<MetaItem>
1182 where I: Iterator<Item = TokenTree>,
1184 let name = match tokens.next() {
1185 Some(TokenTree::Token(span, Token::Ident(ident))) => {
1186 if let Some(TokenTree::Token(_, Token::ModSep)) = tokens.peek() {
1188 let mut segments = vec![];
1190 if let Some(TokenTree::Token(span, Token::Ident(ident))) = tokens.next() {
1191 segments.push(ast::PathSegment::from_ident(ident, span));
1195 if let Some(TokenTree::Token(_, Token::ModSep)) = tokens.peek() {
1201 ast::Path { span, segments }
1203 ast::Path::from_ident(span, ident)
1206 Some(TokenTree::Token(_, Token::Interpolated(ref nt))) => match nt.0 {
1207 token::Nonterminal::NtIdent(ident) => {
1208 ast::Path::from_ident(ident.span, ident.node)
1210 token::Nonterminal::NtMeta(ref meta) => return Some(meta.clone()),
1211 token::Nonterminal::NtPath(ref path) => path.clone(),
1216 let list_closing_paren_pos = tokens.peek().map(|tt| tt.span().hi());
1217 let node = MetaItemKind::from_tokens(tokens)?;
1218 let hi = match node {
1219 MetaItemKind::NameValue(ref lit) => lit.span.hi(),
1220 MetaItemKind::List(..) => list_closing_paren_pos.unwrap_or(name.span.hi()),
1221 _ => name.span.hi(),
1223 let span = name.span.with_hi(hi);
1224 Some(MetaItem { name, node, span })
1229 pub fn tokens(&self, span: Span) -> TokenStream {
1231 MetaItemKind::Word => TokenStream::empty(),
1232 MetaItemKind::NameValue(ref lit) => {
1233 TokenStream::concat(vec![TokenTree::Token(span, Token::Eq).into(), lit.tokens()])
1235 MetaItemKind::List(ref list) => {
1236 let mut tokens = Vec::new();
1237 for (i, item) in list.iter().enumerate() {
1239 tokens.push(TokenTree::Token(span, Token::Comma).into());
1241 tokens.push(item.node.tokens());
1243 TokenTree::Delimited(span, Delimited {
1244 delim: token::Paren,
1245 tts: TokenStream::concat(tokens).into(),
1251 fn from_tokens<I>(tokens: &mut iter::Peekable<I>) -> Option<MetaItemKind>
1252 where I: Iterator<Item = TokenTree>,
1254 let delimited = match tokens.peek().cloned() {
1255 Some(TokenTree::Token(_, token::Eq)) => {
1257 return if let Some(TokenTree::Token(span, token)) = tokens.next() {
1258 LitKind::from_token(token)
1259 .map(|lit| MetaItemKind::NameValue(Spanned { node: lit, span: span }))
1264 Some(TokenTree::Delimited(_, ref delimited)) if delimited.delim == token::Paren => {
1268 _ => return Some(MetaItemKind::Word),
1271 let mut tokens = delimited.into_trees().peekable();
1272 let mut result = Vec::new();
1273 while let Some(..) = tokens.peek() {
1274 let item = NestedMetaItemKind::from_tokens(&mut tokens)?;
1275 result.push(respan(item.span(), item));
1276 match tokens.next() {
1277 None | Some(TokenTree::Token(_, Token::Comma)) => {}
1281 Some(MetaItemKind::List(result))
1285 impl NestedMetaItemKind {
1286 fn span(&self) -> Span {
1288 NestedMetaItemKind::MetaItem(ref item) => item.span,
1289 NestedMetaItemKind::Literal(ref lit) => lit.span,
1293 fn tokens(&self) -> TokenStream {
1295 NestedMetaItemKind::MetaItem(ref item) => item.tokens(),
1296 NestedMetaItemKind::Literal(ref lit) => lit.tokens(),
1300 fn from_tokens<I>(tokens: &mut iter::Peekable<I>) -> Option<NestedMetaItemKind>
1301 where I: Iterator<Item = TokenTree>,
1303 if let Some(TokenTree::Token(span, token)) = tokens.peek().cloned() {
1304 if let Some(node) = LitKind::from_token(token) {
1306 return Some(NestedMetaItemKind::Literal(respan(span, node)));
1310 MetaItem::from_tokens(tokens).map(NestedMetaItemKind::MetaItem)
1315 fn tokens(&self) -> TokenStream {
1316 TokenTree::Token(self.span, self.node.token()).into()
1321 fn token(&self) -> Token {
1325 LitKind::Str(string, ast::StrStyle::Cooked) => {
1326 let mut escaped = String::new();
1327 for ch in string.as_str().chars() {
1328 escaped.extend(ch.escape_unicode());
1330 Token::Literal(token::Lit::Str_(Symbol::intern(&escaped)), None)
1332 LitKind::Str(string, ast::StrStyle::Raw(n)) => {
1333 Token::Literal(token::Lit::StrRaw(string, n), None)
1335 LitKind::ByteStr(ref bytes) => {
1336 let string = bytes.iter().cloned().flat_map(ascii::escape_default)
1337 .map(Into::<char>::into).collect::<String>();
1338 Token::Literal(token::Lit::ByteStr(Symbol::intern(&string)), None)
1340 LitKind::Byte(byte) => {
1341 let string: String = ascii::escape_default(byte).map(Into::<char>::into).collect();
1342 Token::Literal(token::Lit::Byte(Symbol::intern(&string)), None)
1344 LitKind::Char(ch) => {
1345 let string: String = ch.escape_default().map(Into::<char>::into).collect();
1346 Token::Literal(token::Lit::Char(Symbol::intern(&string)), None)
1348 LitKind::Int(n, ty) => {
1349 let suffix = match ty {
1350 ast::LitIntType::Unsigned(ty) => Some(Symbol::intern(ty.ty_to_string())),
1351 ast::LitIntType::Signed(ty) => Some(Symbol::intern(ty.ty_to_string())),
1352 ast::LitIntType::Unsuffixed => None,
1354 Token::Literal(token::Lit::Integer(Symbol::intern(&n.to_string())), suffix)
1356 LitKind::Float(symbol, ty) => {
1357 Token::Literal(token::Lit::Float(symbol), Some(Symbol::intern(ty.ty_to_string())))
1359 LitKind::FloatUnsuffixed(symbol) => Token::Literal(token::Lit::Float(symbol), None),
1360 LitKind::Bool(value) => Token::Ident(Ident::with_empty_ctxt(Symbol::intern(if value {
1368 fn from_token(token: Token) -> Option<LitKind> {
1370 Token::Ident(ident, false) if ident.name == "true" => Some(LitKind::Bool(true)),
1371 Token::Ident(ident, false) if ident.name == "false" => Some(LitKind::Bool(false)),
1372 Token::Interpolated(ref nt) => match nt.0 {
1373 token::NtExpr(ref v) => match v.node {
1374 ExprKind::Lit(ref lit) => Some(lit.node.clone()),
1379 Token::Literal(lit, suf) => {
1380 let (suffix_illegal, result) = parse::lit_token(lit, suf, None);
1381 if suffix_illegal && suf.is_some() {
1391 pub trait HasAttrs: Sized {
1392 fn attrs(&self) -> &[ast::Attribute];
1393 fn map_attrs<F: FnOnce(Vec<ast::Attribute>) -> Vec<ast::Attribute>>(self, f: F) -> Self;
1396 impl<T: HasAttrs> HasAttrs for Spanned<T> {
1397 fn attrs(&self) -> &[ast::Attribute] { self.node.attrs() }
1398 fn map_attrs<F: FnOnce(Vec<ast::Attribute>) -> Vec<ast::Attribute>>(self, f: F) -> Self {
1399 respan(self.span, self.node.map_attrs(f))
1403 impl HasAttrs for Vec<Attribute> {
1404 fn attrs(&self) -> &[Attribute] {
1407 fn map_attrs<F: FnOnce(Vec<Attribute>) -> Vec<Attribute>>(self, f: F) -> Self {
1412 impl HasAttrs for ThinVec<Attribute> {
1413 fn attrs(&self) -> &[Attribute] {
1416 fn map_attrs<F: FnOnce(Vec<Attribute>) -> Vec<Attribute>>(self, f: F) -> Self {
1417 f(self.into()).into()
1421 impl<T: HasAttrs + 'static> HasAttrs for P<T> {
1422 fn attrs(&self) -> &[Attribute] {
1425 fn map_attrs<F: FnOnce(Vec<Attribute>) -> Vec<Attribute>>(self, f: F) -> Self {
1426 self.map(|t| t.map_attrs(f))
1430 impl HasAttrs for StmtKind {
1431 fn attrs(&self) -> &[Attribute] {
1433 StmtKind::Local(ref local) => local.attrs(),
1434 StmtKind::Item(..) => &[],
1435 StmtKind::Expr(ref expr) | StmtKind::Semi(ref expr) => expr.attrs(),
1436 StmtKind::Mac(ref mac) => {
1437 let (_, _, ref attrs) = **mac;
1443 fn map_attrs<F: FnOnce(Vec<Attribute>) -> Vec<Attribute>>(self, f: F) -> Self {
1445 StmtKind::Local(local) => StmtKind::Local(local.map_attrs(f)),
1446 StmtKind::Item(..) => self,
1447 StmtKind::Expr(expr) => StmtKind::Expr(expr.map_attrs(f)),
1448 StmtKind::Semi(expr) => StmtKind::Semi(expr.map_attrs(f)),
1449 StmtKind::Mac(mac) => StmtKind::Mac(mac.map(|(mac, style, attrs)| {
1450 (mac, style, attrs.map_attrs(f))
1456 impl HasAttrs for Stmt {
1457 fn attrs(&self) -> &[ast::Attribute] { self.node.attrs() }
1458 fn map_attrs<F: FnOnce(Vec<ast::Attribute>) -> Vec<ast::Attribute>>(self, f: F) -> Self {
1459 Stmt { id: self.id, node: self.node.map_attrs(f), span: self.span }
1463 macro_rules! derive_has_attrs {
1464 ($($ty:path),*) => { $(
1465 impl HasAttrs for $ty {
1466 fn attrs(&self) -> &[Attribute] {
1470 fn map_attrs<F>(mut self, f: F) -> Self
1471 where F: FnOnce(Vec<Attribute>) -> Vec<Attribute>,
1473 self.attrs = self.attrs.map_attrs(f);
1481 Item, Expr, Local, ast::ForeignItem, ast::StructField, ast::ImplItem, ast::TraitItem, ast::Arm,
1482 ast::Field, ast::FieldPat, ast::Variant_