1 //! Functions dealing with attributes and meta items
6 cfg_matches, contains_feature_attr, eval_condition, find_crate_name, find_deprecation,
7 find_repr_attrs, find_stability, find_unwind_attr, Deprecation, InlineAttr, OptimizeAttr,
8 IntType, ReprAttr, RustcDeprecation, Stability, StabilityLevel, UnwindAttr,
12 pub use StabilityLevel::*;
15 use crate::ast::{AttrId, Attribute, AttrStyle, Name, Ident, Path, PathSegment};
16 use crate::ast::{MetaItem, MetaItemKind, NestedMetaItem};
17 use crate::ast::{Lit, LitKind, Expr, Item, Local, Stmt, StmtKind, GenericParam};
18 use crate::mut_visit::visit_clobber;
19 use crate::source_map::{BytePos, Spanned, dummy_spanned};
20 use crate::parse::lexer::comments::{doc_comment_style, strip_doc_comment_decoration};
21 use crate::parse::parser::Parser;
22 use crate::parse::{self, ParseSess, PResult};
23 use crate::parse::token::{self, TokenKind};
25 use crate::symbol::{sym, Symbol};
27 use crate::tokenstream::{TokenStream, TokenTree, DelimSpan};
31 use syntax_pos::{FileName, Span};
34 use std::ops::DerefMut;
36 pub fn mark_used(attr: &Attribute) {
37 debug!("Marking {:?} as used.", attr);
38 GLOBALS.with(|globals| {
39 globals.used_attrs.lock().insert(attr.id);
43 pub fn is_used(attr: &Attribute) -> bool {
44 GLOBALS.with(|globals| {
45 globals.used_attrs.lock().contains(attr.id)
49 pub fn mark_known(attr: &Attribute) {
50 debug!("Marking {:?} as known.", attr);
51 GLOBALS.with(|globals| {
52 globals.known_attrs.lock().insert(attr.id);
56 pub fn is_known(attr: &Attribute) -> bool {
57 GLOBALS.with(|globals| {
58 globals.known_attrs.lock().contains(attr.id)
62 pub fn is_known_lint_tool(m_item: Ident) -> bool {
63 ["clippy"].contains(&m_item.as_str().as_ref())
67 /// Returns the MetaItem if self is a NestedMetaItem::MetaItem.
68 pub fn meta_item(&self) -> Option<&MetaItem> {
70 NestedMetaItem::MetaItem(ref item) => Some(item),
75 /// Returns the Lit if self is a NestedMetaItem::Literal.
76 pub fn literal(&self) -> Option<&Lit> {
78 NestedMetaItem::Literal(ref lit) => Some(lit),
83 /// Returns `true` if this list item is a MetaItem with a name of `name`.
84 pub fn check_name(&self, name: Symbol) -> bool {
85 self.meta_item().map_or(false, |meta_item| meta_item.check_name(name))
88 /// For a single-segment meta-item returns its name, otherwise returns `None`.
89 pub fn ident(&self) -> Option<Ident> {
90 self.meta_item().and_then(|meta_item| meta_item.ident())
92 pub fn name_or_empty(&self) -> Symbol {
93 self.ident().unwrap_or(Ident::invalid()).name
96 /// Gets the string value if self is a MetaItem and the MetaItem is a
97 /// MetaItemKind::NameValue variant containing a string, otherwise None.
98 pub fn value_str(&self) -> Option<Symbol> {
99 self.meta_item().and_then(|meta_item| meta_item.value_str())
102 /// Returns a name and single literal value tuple of the MetaItem.
103 pub fn name_value_literal(&self) -> Option<(Name, &Lit)> {
104 self.meta_item().and_then(
105 |meta_item| meta_item.meta_item_list().and_then(
107 if meta_item_list.len() == 1 {
108 if let Some(ident) = meta_item.ident() {
109 if let Some(lit) = meta_item_list[0].literal() {
110 return Some((ident.name, lit));
118 /// Gets a list of inner meta items from a list MetaItem type.
119 pub fn meta_item_list(&self) -> Option<&[NestedMetaItem]> {
120 self.meta_item().and_then(|meta_item| meta_item.meta_item_list())
123 /// Returns `true` if the variant is MetaItem.
124 pub fn is_meta_item(&self) -> bool {
125 self.meta_item().is_some()
128 /// Returns `true` if the variant is Literal.
129 pub fn is_literal(&self) -> bool {
130 self.literal().is_some()
133 /// Returns `true` if self is a MetaItem and the meta item is a word.
134 pub fn is_word(&self) -> bool {
135 self.meta_item().map_or(false, |meta_item| meta_item.is_word())
138 /// Returns `true` if self is a MetaItem and the meta item is a ValueString.
139 pub fn is_value_str(&self) -> bool {
140 self.value_str().is_some()
143 /// Returns `true` if self is a MetaItem and the meta item is a list.
144 pub fn is_meta_item_list(&self) -> bool {
145 self.meta_item_list().is_some()
150 /// Returns `true` if the attribute's path matches the argument. If it matches, then the
151 /// attribute is marked as used.
153 /// To check the attribute name without marking it used, use the `path` field directly.
154 pub fn check_name(&self, name: Symbol) -> bool {
155 let matches = self.path == name;
162 /// For a single-segment attribute returns its name, otherwise returns `None`.
163 pub fn ident(&self) -> Option<Ident> {
164 if self.path.segments.len() == 1 {
165 Some(self.path.segments[0].ident)
170 pub fn name_or_empty(&self) -> Symbol {
171 self.ident().unwrap_or(Ident::invalid()).name
174 pub fn value_str(&self) -> Option<Symbol> {
175 self.meta().and_then(|meta| meta.value_str())
178 pub fn meta_item_list(&self) -> Option<Vec<NestedMetaItem>> {
180 Some(MetaItem { node: MetaItemKind::List(list), .. }) => Some(list),
185 pub fn is_word(&self) -> bool {
186 self.tokens.is_empty()
189 pub fn is_meta_item_list(&self) -> bool {
190 self.meta_item_list().is_some()
193 /// Indicates if the attribute is a Value String.
194 pub fn is_value_str(&self) -> bool {
195 self.value_str().is_some()
200 /// For a single-segment meta-item returns its name, otherwise returns `None`.
201 pub fn ident(&self) -> Option<Ident> {
202 if self.path.segments.len() == 1 {
203 Some(self.path.segments[0].ident)
208 pub fn name_or_empty(&self) -> Symbol {
209 self.ident().unwrap_or(Ident::invalid()).name
212 // #[attribute(name = "value")]
214 pub fn name_value_literal(&self) -> Option<&Lit> {
216 MetaItemKind::NameValue(v) => Some(v),
221 pub fn value_str(&self) -> Option<Symbol> {
223 MetaItemKind::NameValue(ref v) => {
225 LitKind::Str(ref s, _) => Some(*s),
233 pub fn meta_item_list(&self) -> Option<&[NestedMetaItem]> {
235 MetaItemKind::List(ref l) => Some(&l[..]),
240 pub fn is_word(&self) -> bool {
242 MetaItemKind::Word => true,
247 pub fn check_name(&self, name: Symbol) -> bool {
251 pub fn is_value_str(&self) -> bool {
252 self.value_str().is_some()
255 pub fn is_meta_item_list(&self) -> bool {
256 self.meta_item_list().is_some()
261 /// Extracts the MetaItem from inside this Attribute.
262 pub fn meta(&self) -> Option<MetaItem> {
263 let mut tokens = self.tokens.trees().peekable();
265 path: self.path.clone(),
266 node: if let Some(node) = MetaItemKind::from_tokens(&mut tokens) {
267 if tokens.peek().is_some() {
278 pub fn parse<'a, T, F>(&self, sess: &'a ParseSess, mut f: F) -> PResult<'a, T>
279 where F: FnMut(&mut Parser<'a>) -> PResult<'a, T>,
281 let mut parser = Parser::new(
289 let result = f(&mut parser)?;
290 if parser.token != token::Eof {
291 parser.unexpected()?;
296 pub fn parse_list<'a, T, F>(&self, sess: &'a ParseSess, mut f: F) -> PResult<'a, Vec<T>>
297 where F: FnMut(&mut Parser<'a>) -> PResult<'a, T>,
299 if self.tokens.is_empty() {
300 return Ok(Vec::new());
302 self.parse(sess, |parser| {
303 parser.expect(&token::OpenDelim(token::Paren))?;
304 let mut list = Vec::new();
305 while !parser.eat(&token::CloseDelim(token::Paren)) {
306 list.push(f(parser)?);
307 if !parser.eat(&token::Comma) {
308 parser.expect(&token::CloseDelim(token::Paren))?;
316 pub fn parse_meta<'a>(&self, sess: &'a ParseSess) -> PResult<'a, MetaItem> {
318 path: self.path.clone(),
319 node: self.parse(sess, |parser| parser.parse_meta_item_kind())?,
324 /// Converts self to a normal #[doc="foo"] comment, if it is a
325 /// comment like `///` or `/** */`. (Returns self unchanged for
326 /// non-sugared doc attributes.)
327 pub fn with_desugared_doc<T, F>(&self, f: F) -> T where
328 F: FnOnce(&Attribute) -> T,
330 if self.is_sugared_doc {
331 let comment = self.value_str().unwrap();
332 let meta = mk_name_value_item_str(
333 Ident::with_empty_ctxt(sym::doc),
334 dummy_spanned(Symbol::intern(&strip_doc_comment_decoration(&comment.as_str()))));
335 let mut attr = if self.style == ast::AttrStyle::Outer {
336 mk_attr_outer(self.span, self.id, meta)
338 mk_attr_inner(self.span, self.id, meta)
340 attr.is_sugared_doc = true;
350 pub fn mk_name_value_item_str(ident: Ident, value: Spanned<Symbol>) -> MetaItem {
351 let lit_kind = LitKind::Str(value.node, ast::StrStyle::Cooked);
352 mk_name_value_item(ident.span.to(value.span), ident, lit_kind, value.span)
355 pub fn mk_name_value_item(span: Span, ident: Ident, lit_kind: LitKind, lit_span: Span) -> MetaItem {
356 let lit = Lit::from_lit_kind(lit_kind, lit_span);
357 MetaItem { path: Path::from_ident(ident), span, node: MetaItemKind::NameValue(lit) }
360 pub fn mk_list_item(span: Span, ident: Ident, items: Vec<NestedMetaItem>) -> MetaItem {
361 MetaItem { path: Path::from_ident(ident), span, node: MetaItemKind::List(items) }
364 pub fn mk_word_item(ident: Ident) -> MetaItem {
365 MetaItem { path: Path::from_ident(ident), span: ident.span, node: MetaItemKind::Word }
368 pub fn mk_nested_word_item(ident: Ident) -> NestedMetaItem {
369 NestedMetaItem::MetaItem(mk_word_item(ident))
372 pub fn mk_attr_id() -> AttrId {
373 use std::sync::atomic::AtomicUsize;
374 use std::sync::atomic::Ordering;
376 static NEXT_ATTR_ID: AtomicUsize = AtomicUsize::new(0);
378 let id = NEXT_ATTR_ID.fetch_add(1, Ordering::SeqCst);
379 assert!(id != ::std::usize::MAX);
383 /// Returns an inner attribute with the given value.
384 pub fn mk_attr_inner(span: Span, id: AttrId, item: MetaItem) -> Attribute {
385 mk_spanned_attr_inner(span, id, item)
388 /// Returns an inner attribute with the given value and span.
389 pub fn mk_spanned_attr_inner(sp: Span, id: AttrId, item: MetaItem) -> Attribute {
392 style: ast::AttrStyle::Inner,
394 tokens: item.node.tokens(item.span),
395 is_sugared_doc: false,
400 /// Returns an outer attribute with the given value.
401 pub fn mk_attr_outer(span: Span, id: AttrId, item: MetaItem) -> Attribute {
402 mk_spanned_attr_outer(span, id, item)
405 /// Returns an outer attribute with the given value and span.
406 pub fn mk_spanned_attr_outer(sp: Span, id: AttrId, item: MetaItem) -> Attribute {
409 style: ast::AttrStyle::Outer,
411 tokens: item.node.tokens(item.span),
412 is_sugared_doc: false,
417 pub fn mk_sugared_doc_attr(id: AttrId, text: Symbol, span: Span) -> Attribute {
418 let style = doc_comment_style(&text.as_str());
419 let lit_kind = LitKind::Str(text, ast::StrStyle::Cooked);
420 let lit = Lit::from_lit_kind(lit_kind, span);
424 path: Path::from_ident(Ident::with_empty_ctxt(sym::doc).with_span_pos(span)),
425 tokens: MetaItemKind::NameValue(lit).tokens(span),
426 is_sugared_doc: true,
431 pub fn list_contains_name(items: &[NestedMetaItem], name: Symbol) -> bool {
432 items.iter().any(|item| {
433 item.check_name(name)
437 pub fn contains_name(attrs: &[Attribute], name: Symbol) -> bool {
438 attrs.iter().any(|item| {
439 item.check_name(name)
443 pub fn find_by_name<'a>(attrs: &'a [Attribute], name: Symbol) -> Option<&'a Attribute> {
444 attrs.iter().find(|attr| attr.check_name(name))
447 pub fn filter_by_name<'a>(attrs: &'a [Attribute], name: Symbol)
448 -> impl Iterator<Item = &'a Attribute> {
449 attrs.iter().filter(move |attr| attr.check_name(name))
452 pub fn first_attr_value_str_by_name(attrs: &[Attribute], name: Symbol) -> Option<Symbol> {
454 .find(|at| at.check_name(name))
455 .and_then(|at| at.value_str())
459 fn tokens(&self) -> TokenStream {
460 let mut idents = vec![];
461 let mut last_pos = BytePos(0 as u32);
462 for (i, segment) in self.path.segments.iter().enumerate() {
463 let is_first = i == 0;
465 let mod_sep_span = Span::new(last_pos,
466 segment.ident.span.lo(),
467 segment.ident.span.ctxt());
468 idents.push(TokenTree::Token(mod_sep_span, token::ModSep).into());
470 idents.push(TokenTree::Token(segment.ident.span,
471 TokenKind::from_ast_ident(segment.ident)).into());
472 last_pos = segment.ident.span.hi();
474 self.node.tokens(self.span).append_to_tree_and_joint_vec(&mut idents);
475 TokenStream::new(idents)
478 fn from_tokens<I>(tokens: &mut iter::Peekable<I>) -> Option<MetaItem>
479 where I: Iterator<Item = TokenTree>,
481 // FIXME: Share code with `parse_path`.
482 let path = match tokens.next() {
483 Some(TokenTree::Token(span, token @ token::Ident(..))) |
484 Some(TokenTree::Token(span, token @ token::ModSep)) => 'arm: {
485 let mut segments = if let token::Ident(ident, _) = token {
486 if let Some(TokenTree::Token(_, token::ModSep)) = tokens.peek() {
488 vec![PathSegment::from_ident(ident.with_span_pos(span))]
490 break 'arm Path::from_ident(ident.with_span_pos(span));
493 vec![PathSegment::path_root(span)]
496 if let Some(TokenTree::Token(span,
497 token::Ident(ident, _))) = tokens.next() {
498 segments.push(PathSegment::from_ident(ident.with_span_pos(span)));
502 if let Some(TokenTree::Token(_, token::ModSep)) = tokens.peek() {
508 let span = span.with_hi(segments.last().unwrap().ident.span.hi());
509 Path { span, segments }
511 Some(TokenTree::Token(_, token::Interpolated(nt))) => match *nt {
512 token::Nonterminal::NtIdent(ident, _) => Path::from_ident(ident),
513 token::Nonterminal::NtMeta(ref meta) => return Some(meta.clone()),
514 token::Nonterminal::NtPath(ref path) => path.clone(),
519 let list_closing_paren_pos = tokens.peek().map(|tt| tt.span().hi());
520 let node = MetaItemKind::from_tokens(tokens)?;
521 let hi = match node {
522 MetaItemKind::NameValue(ref lit) => lit.span.hi(),
523 MetaItemKind::List(..) => list_closing_paren_pos.unwrap_or(path.span.hi()),
526 let span = path.span.with_hi(hi);
527 Some(MetaItem { path, node, span })
532 pub fn tokens(&self, span: Span) -> TokenStream {
534 MetaItemKind::Word => TokenStream::empty(),
535 MetaItemKind::NameValue(ref lit) => {
536 let mut vec = vec![TokenTree::Token(span, token::Eq).into()];
537 lit.tokens().append_to_tree_and_joint_vec(&mut vec);
538 TokenStream::new(vec)
540 MetaItemKind::List(ref list) => {
541 let mut tokens = Vec::new();
542 for (i, item) in list.iter().enumerate() {
544 tokens.push(TokenTree::Token(span, token::Comma).into());
546 item.tokens().append_to_tree_and_joint_vec(&mut tokens);
548 TokenTree::Delimited(
549 DelimSpan::from_single(span),
551 TokenStream::new(tokens).into(),
557 fn from_tokens<I>(tokens: &mut iter::Peekable<I>) -> Option<MetaItemKind>
558 where I: Iterator<Item = TokenTree>,
560 let delimited = match tokens.peek().cloned() {
561 Some(TokenTree::Token(_, token::Eq)) => {
563 return if let Some(TokenTree::Token(span, token)) = tokens.next() {
564 Lit::from_token(&token, span).ok().map(MetaItemKind::NameValue)
569 Some(TokenTree::Delimited(_, delim, ref tts)) if delim == token::Paren => {
573 _ => return Some(MetaItemKind::Word),
576 let mut tokens = delimited.into_trees().peekable();
577 let mut result = Vec::new();
578 while let Some(..) = tokens.peek() {
579 let item = NestedMetaItem::from_tokens(&mut tokens)?;
581 match tokens.next() {
582 None | Some(TokenTree::Token(_, token::Comma)) => {}
586 Some(MetaItemKind::List(result))
590 impl NestedMetaItem {
591 pub fn span(&self) -> Span {
593 NestedMetaItem::MetaItem(ref item) => item.span,
594 NestedMetaItem::Literal(ref lit) => lit.span,
598 fn tokens(&self) -> TokenStream {
600 NestedMetaItem::MetaItem(ref item) => item.tokens(),
601 NestedMetaItem::Literal(ref lit) => lit.tokens(),
605 fn from_tokens<I>(tokens: &mut iter::Peekable<I>) -> Option<NestedMetaItem>
606 where I: Iterator<Item = TokenTree>,
608 if let Some(TokenTree::Token(span, token)) = tokens.peek().cloned() {
609 if let Ok(lit) = Lit::from_token(&token, span) {
611 return Some(NestedMetaItem::Literal(lit));
615 MetaItem::from_tokens(tokens).map(NestedMetaItem::MetaItem)
619 pub trait HasAttrs: Sized {
620 fn attrs(&self) -> &[ast::Attribute];
621 fn visit_attrs<F: FnOnce(&mut Vec<ast::Attribute>)>(&mut self, f: F);
624 impl<T: HasAttrs> HasAttrs for Spanned<T> {
625 fn attrs(&self) -> &[ast::Attribute] { self.node.attrs() }
626 fn visit_attrs<F: FnOnce(&mut Vec<ast::Attribute>)>(&mut self, f: F) {
627 self.node.visit_attrs(f);
631 impl HasAttrs for Vec<Attribute> {
632 fn attrs(&self) -> &[Attribute] {
635 fn visit_attrs<F: FnOnce(&mut Vec<Attribute>)>(&mut self, f: F) {
640 impl HasAttrs for ThinVec<Attribute> {
641 fn attrs(&self) -> &[Attribute] {
644 fn visit_attrs<F: FnOnce(&mut Vec<Attribute>)>(&mut self, f: F) {
645 visit_clobber(self, |this| {
646 let mut vec = this.into();
653 impl<T: HasAttrs + 'static> HasAttrs for P<T> {
654 fn attrs(&self) -> &[Attribute] {
657 fn visit_attrs<F: FnOnce(&mut Vec<Attribute>)>(&mut self, f: F) {
658 (**self).visit_attrs(f);
662 impl HasAttrs for StmtKind {
663 fn attrs(&self) -> &[Attribute] {
665 StmtKind::Local(ref local) => local.attrs(),
666 StmtKind::Item(..) => &[],
667 StmtKind::Expr(ref expr) | StmtKind::Semi(ref expr) => expr.attrs(),
668 StmtKind::Mac(ref mac) => {
669 let (_, _, ref attrs) = **mac;
675 fn visit_attrs<F: FnOnce(&mut Vec<Attribute>)>(&mut self, f: F) {
677 StmtKind::Local(local) => local.visit_attrs(f),
678 StmtKind::Item(..) => {}
679 StmtKind::Expr(expr) => expr.visit_attrs(f),
680 StmtKind::Semi(expr) => expr.visit_attrs(f),
681 StmtKind::Mac(mac) => {
682 let (_mac, _style, attrs) = mac.deref_mut();
683 attrs.visit_attrs(f);
689 impl HasAttrs for Stmt {
690 fn attrs(&self) -> &[ast::Attribute] {
694 fn visit_attrs<F: FnOnce(&mut Vec<ast::Attribute>)>(&mut self, f: F) {
695 self.node.visit_attrs(f);
699 impl HasAttrs for GenericParam {
700 fn attrs(&self) -> &[ast::Attribute] {
704 fn visit_attrs<F: FnOnce(&mut Vec<Attribute>)>(&mut self, f: F) {
705 self.attrs.visit_attrs(f);
709 macro_rules! derive_has_attrs {
710 ($($ty:path),*) => { $(
711 impl HasAttrs for $ty {
712 fn attrs(&self) -> &[Attribute] {
716 fn visit_attrs<F: FnOnce(&mut Vec<Attribute>)>(&mut self, f: F) {
717 self.attrs.visit_attrs(f);
724 Item, Expr, Local, ast::ForeignItem, ast::StructField, ast::ImplItem, ast::TraitItem, ast::Arm,
725 ast::Field, ast::FieldPat, ast::Variant_
728 pub fn inject(mut krate: ast::Crate, parse_sess: &ParseSess, attrs: &[String]) -> ast::Crate {
729 for raw_attr in attrs {
730 let mut parser = parse::new_parser_from_source_str(
732 FileName::cli_crate_attr_source_code(&raw_attr),
736 let start_span = parser.span;
737 let (path, tokens) = panictry!(parser.parse_meta_item_unrestricted());
738 let end_span = parser.span;
739 if parser.token != token::Eof {
740 parse_sess.span_diagnostic
741 .span_err(start_span.to(end_span), "invalid crate attribute");
745 krate.attrs.push(Attribute {
747 style: AttrStyle::Inner,
750 is_sugared_doc: false,
751 span: start_span.to(end_span),