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, Token};
25 use crate::symbol::{keywords, LocalInternedString, 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<T>(&self, name: T) -> bool
88 self.meta_item().map_or(false, |meta_item| meta_item.check_name(name))
91 /// For a single-segment meta-item returns its name, otherwise returns `None`.
92 pub fn ident(&self) -> Option<Ident> {
93 self.meta_item().and_then(|meta_item| meta_item.ident())
95 pub fn name_or_empty(&self) -> LocalInternedString {
96 self.ident().unwrap_or(keywords::Invalid.ident()).name.as_str()
99 /// Gets the string value if self is a MetaItem and the MetaItem is a
100 /// MetaItemKind::NameValue variant containing a string, otherwise None.
101 pub fn value_str(&self) -> Option<Symbol> {
102 self.meta_item().and_then(|meta_item| meta_item.value_str())
105 /// Returns a name and single literal value tuple of the MetaItem.
106 pub fn name_value_literal(&self) -> Option<(Name, &Lit)> {
107 self.meta_item().and_then(
108 |meta_item| meta_item.meta_item_list().and_then(
110 if meta_item_list.len() == 1 {
111 if let Some(ident) = meta_item.ident() {
112 if let Some(lit) = meta_item_list[0].literal() {
113 return Some((ident.name, lit));
121 /// Gets a list of inner meta items from a list MetaItem type.
122 pub fn meta_item_list(&self) -> Option<&[NestedMetaItem]> {
123 self.meta_item().and_then(|meta_item| meta_item.meta_item_list())
126 /// Returns `true` if the variant is MetaItem.
127 pub fn is_meta_item(&self) -> bool {
128 self.meta_item().is_some()
131 /// Returns `true` if the variant is Literal.
132 pub fn is_literal(&self) -> bool {
133 self.literal().is_some()
136 /// Returns `true` if self is a MetaItem and the meta item is a word.
137 pub fn is_word(&self) -> bool {
138 self.meta_item().map_or(false, |meta_item| meta_item.is_word())
141 /// Returns `true` if self is a MetaItem and the meta item is a ValueString.
142 pub fn is_value_str(&self) -> bool {
143 self.value_str().is_some()
146 /// Returns `true` if self is a MetaItem and the meta item is a list.
147 pub fn is_meta_item_list(&self) -> bool {
148 self.meta_item_list().is_some()
153 /// Returns `true` if the attribute's path matches the argument. If it matches, then the
154 /// attribute is marked as used.
156 /// To check the attribute name without marking it used, use the `path` field directly.
157 pub fn check_name<T>(&self, name: T) -> bool
161 let matches = self.path == name;
168 /// For a single-segment attribute returns its name, otherwise returns `None`.
169 pub fn ident(&self) -> Option<Ident> {
170 if self.path.segments.len() == 1 {
171 Some(self.path.segments[0].ident)
176 pub fn name_or_empty(&self) -> LocalInternedString {
177 self.ident().unwrap_or(keywords::Invalid.ident()).name.as_str()
180 pub fn value_str(&self) -> Option<Symbol> {
181 self.meta().and_then(|meta| meta.value_str())
184 pub fn meta_item_list(&self) -> Option<Vec<NestedMetaItem>> {
186 Some(MetaItem { node: MetaItemKind::List(list), .. }) => Some(list),
191 pub fn is_word(&self) -> bool {
192 self.tokens.is_empty()
195 pub fn is_meta_item_list(&self) -> bool {
196 self.meta_item_list().is_some()
199 /// Indicates if the attribute is a Value String.
200 pub fn is_value_str(&self) -> bool {
201 self.value_str().is_some()
206 /// For a single-segment meta-item returns its name, otherwise returns `None`.
207 pub fn ident(&self) -> Option<Ident> {
208 if self.path.segments.len() == 1 {
209 Some(self.path.segments[0].ident)
214 pub fn name_or_empty(&self) -> LocalInternedString {
215 self.ident().unwrap_or(keywords::Invalid.ident()).name.as_str()
218 // #[attribute(name = "value")]
220 pub fn name_value_literal(&self) -> Option<&Lit> {
222 MetaItemKind::NameValue(v) => Some(v),
227 pub fn value_str(&self) -> Option<Symbol> {
229 MetaItemKind::NameValue(ref v) => {
231 LitKind::Str(ref s, _) => Some(*s),
239 pub fn meta_item_list(&self) -> Option<&[NestedMetaItem]> {
241 MetaItemKind::List(ref l) => Some(&l[..]),
246 pub fn is_word(&self) -> bool {
248 MetaItemKind::Word => true,
253 pub fn check_name<T>(&self, name: T) -> bool
260 pub fn is_value_str(&self) -> bool {
261 self.value_str().is_some()
264 pub fn is_meta_item_list(&self) -> bool {
265 self.meta_item_list().is_some()
270 /// Extracts the MetaItem from inside this Attribute.
271 pub fn meta(&self) -> Option<MetaItem> {
272 let mut tokens = self.tokens.trees().peekable();
274 path: self.path.clone(),
275 node: if let Some(node) = MetaItemKind::from_tokens(&mut tokens) {
276 if tokens.peek().is_some() {
287 pub fn parse<'a, T, F>(&self, sess: &'a ParseSess, mut f: F) -> PResult<'a, T>
288 where F: FnMut(&mut Parser<'a>) -> PResult<'a, T>,
290 let mut parser = Parser::new(sess, self.tokens.clone(), None, false, false);
291 let result = f(&mut parser)?;
292 if parser.token != token::Eof {
293 parser.unexpected()?;
298 pub fn parse_list<'a, T, F>(&self, sess: &'a ParseSess, mut f: F) -> PResult<'a, Vec<T>>
299 where F: FnMut(&mut Parser<'a>) -> PResult<'a, T>,
301 if self.tokens.is_empty() {
302 return Ok(Vec::new());
304 self.parse(sess, |parser| {
305 parser.expect(&token::OpenDelim(token::Paren))?;
306 let mut list = Vec::new();
307 while !parser.eat(&token::CloseDelim(token::Paren)) {
308 list.push(f(parser)?);
309 if !parser.eat(&token::Comma) {
310 parser.expect(&token::CloseDelim(token::Paren))?;
318 pub fn parse_meta<'a>(&self, sess: &'a ParseSess) -> PResult<'a, MetaItem> {
320 path: self.path.clone(),
321 node: self.parse(sess, |parser| parser.parse_meta_item_kind())?,
326 /// Converts self to a normal #[doc="foo"] comment, if it is a
327 /// comment like `///` or `/** */`. (Returns self unchanged for
328 /// non-sugared doc attributes.)
329 pub fn with_desugared_doc<T, F>(&self, f: F) -> T where
330 F: FnOnce(&Attribute) -> T,
332 if self.is_sugared_doc {
333 let comment = self.value_str().unwrap();
334 let meta = mk_name_value_item_str(
335 Ident::from_str("doc"),
336 dummy_spanned(Symbol::intern(&strip_doc_comment_decoration(&comment.as_str()))));
337 let mut attr = if self.style == ast::AttrStyle::Outer {
338 mk_attr_outer(self.span, self.id, meta)
340 mk_attr_inner(self.span, self.id, meta)
342 attr.is_sugared_doc = true;
352 pub fn mk_name_value_item_str(ident: Ident, value: Spanned<Symbol>) -> MetaItem {
353 let lit_kind = LitKind::Str(value.node, ast::StrStyle::Cooked);
354 mk_name_value_item(ident.span.to(value.span), ident, lit_kind, value.span)
357 pub fn mk_name_value_item(span: Span, ident: Ident, lit_kind: LitKind, lit_span: Span) -> MetaItem {
358 let lit = Lit::from_lit_kind(lit_kind, lit_span);
359 MetaItem { path: Path::from_ident(ident), span, node: MetaItemKind::NameValue(lit) }
362 pub fn mk_list_item(span: Span, ident: Ident, items: Vec<NestedMetaItem>) -> MetaItem {
363 MetaItem { path: Path::from_ident(ident), span, node: MetaItemKind::List(items) }
366 pub fn mk_word_item(ident: Ident) -> MetaItem {
367 MetaItem { path: Path::from_ident(ident), span: ident.span, node: MetaItemKind::Word }
370 pub fn mk_nested_word_item(ident: Ident) -> NestedMetaItem {
371 NestedMetaItem::MetaItem(mk_word_item(ident))
374 pub fn mk_attr_id() -> AttrId {
375 use std::sync::atomic::AtomicUsize;
376 use std::sync::atomic::Ordering;
378 static NEXT_ATTR_ID: AtomicUsize = AtomicUsize::new(0);
380 let id = NEXT_ATTR_ID.fetch_add(1, Ordering::SeqCst);
381 assert!(id != ::std::usize::MAX);
385 /// Returns an inner attribute with the given value.
386 pub fn mk_attr_inner(span: Span, id: AttrId, item: MetaItem) -> Attribute {
387 mk_spanned_attr_inner(span, id, item)
390 /// Returns an inner attribute with the given value and span.
391 pub fn mk_spanned_attr_inner(sp: Span, id: AttrId, item: MetaItem) -> Attribute {
394 style: ast::AttrStyle::Inner,
396 tokens: item.node.tokens(item.span),
397 is_sugared_doc: false,
402 /// Returns an outer attribute with the given value.
403 pub fn mk_attr_outer(span: Span, id: AttrId, item: MetaItem) -> Attribute {
404 mk_spanned_attr_outer(span, id, item)
407 /// Returns an outer attribute with the given value and span.
408 pub fn mk_spanned_attr_outer(sp: Span, id: AttrId, item: MetaItem) -> Attribute {
411 style: ast::AttrStyle::Outer,
413 tokens: item.node.tokens(item.span),
414 is_sugared_doc: false,
419 pub fn mk_sugared_doc_attr(id: AttrId, text: Symbol, span: Span) -> Attribute {
420 let style = doc_comment_style(&text.as_str());
421 let lit_kind = LitKind::Str(text, ast::StrStyle::Cooked);
422 let lit = Lit::from_lit_kind(lit_kind, span);
426 path: Path::from_ident(Ident::from_str("doc").with_span_pos(span)),
427 tokens: MetaItemKind::NameValue(lit).tokens(span),
428 is_sugared_doc: true,
433 pub fn list_contains_name(items: &[NestedMetaItem], name: &str) -> bool {
434 items.iter().any(|item| {
435 item.check_name(name)
439 pub fn contains_name(attrs: &[Attribute], name: &str) -> bool {
440 attrs.iter().any(|item| {
441 item.check_name(name)
445 pub fn find_by_name<'a>(attrs: &'a [Attribute], name: &str) -> Option<&'a Attribute> {
446 attrs.iter().find(|attr| attr.check_name(name))
449 pub fn filter_by_name<'a>(attrs: &'a [Attribute], name: &'a str)
450 -> impl Iterator<Item = &'a Attribute> {
451 attrs.iter().filter(move |attr| attr.check_name(name))
454 pub fn first_attr_value_str_by_name(attrs: &[Attribute], name: &str) -> Option<Symbol> {
456 .find(|at| at.check_name(name))
457 .and_then(|at| at.value_str())
461 fn tokens(&self) -> TokenStream {
462 let mut idents = vec![];
463 let mut last_pos = BytePos(0 as u32);
464 for (i, segment) in self.path.segments.iter().enumerate() {
465 let is_first = i == 0;
467 let mod_sep_span = Span::new(last_pos,
468 segment.ident.span.lo(),
469 segment.ident.span.ctxt());
470 idents.push(TokenTree::Token(mod_sep_span, Token::ModSep).into());
472 idents.push(TokenTree::Token(segment.ident.span,
473 Token::from_ast_ident(segment.ident)).into());
474 last_pos = segment.ident.span.hi();
476 self.node.tokens(self.span).append_to_tree_and_joint_vec(&mut idents);
477 TokenStream::new(idents)
480 fn from_tokens<I>(tokens: &mut iter::Peekable<I>) -> Option<MetaItem>
481 where I: Iterator<Item = TokenTree>,
483 // FIXME: Share code with `parse_path`.
484 let path = match tokens.next() {
485 Some(TokenTree::Token(span, token @ Token::Ident(..))) |
486 Some(TokenTree::Token(span, token @ Token::ModSep)) => 'arm: {
487 let mut segments = if let Token::Ident(ident, _) = token {
488 if let Some(TokenTree::Token(_, Token::ModSep)) = tokens.peek() {
490 vec![PathSegment::from_ident(ident.with_span_pos(span))]
492 break 'arm Path::from_ident(ident.with_span_pos(span));
495 vec![PathSegment::path_root(span)]
498 if let Some(TokenTree::Token(span,
499 Token::Ident(ident, _))) = tokens.next() {
500 segments.push(PathSegment::from_ident(ident.with_span_pos(span)));
504 if let Some(TokenTree::Token(_, Token::ModSep)) = tokens.peek() {
510 let span = span.with_hi(segments.last().unwrap().ident.span.hi());
511 Path { span, segments }
513 Some(TokenTree::Token(_, Token::Interpolated(nt))) => match *nt {
514 token::Nonterminal::NtIdent(ident, _) => Path::from_ident(ident),
515 token::Nonterminal::NtMeta(ref meta) => return Some(meta.clone()),
516 token::Nonterminal::NtPath(ref path) => path.clone(),
521 let list_closing_paren_pos = tokens.peek().map(|tt| tt.span().hi());
522 let node = MetaItemKind::from_tokens(tokens)?;
523 let hi = match node {
524 MetaItemKind::NameValue(ref lit) => lit.span.hi(),
525 MetaItemKind::List(..) => list_closing_paren_pos.unwrap_or(path.span.hi()),
528 let span = path.span.with_hi(hi);
529 Some(MetaItem { path, node, span })
534 pub fn tokens(&self, span: Span) -> TokenStream {
536 MetaItemKind::Word => TokenStream::empty(),
537 MetaItemKind::NameValue(ref lit) => {
538 let mut vec = vec![TokenTree::Token(span, Token::Eq).into()];
539 lit.tokens().append_to_tree_and_joint_vec(&mut vec);
540 TokenStream::new(vec)
542 MetaItemKind::List(ref list) => {
543 let mut tokens = Vec::new();
544 for (i, item) in list.iter().enumerate() {
546 tokens.push(TokenTree::Token(span, Token::Comma).into());
548 item.tokens().append_to_tree_and_joint_vec(&mut tokens);
550 TokenTree::Delimited(
551 DelimSpan::from_single(span),
553 TokenStream::new(tokens).into(),
559 fn from_tokens<I>(tokens: &mut iter::Peekable<I>) -> Option<MetaItemKind>
560 where I: Iterator<Item = TokenTree>,
562 let delimited = match tokens.peek().cloned() {
563 Some(TokenTree::Token(_, token::Eq)) => {
565 return if let Some(TokenTree::Token(span, token)) = tokens.next() {
566 Lit::from_token(&token, span, None).map(MetaItemKind::NameValue)
571 Some(TokenTree::Delimited(_, delim, ref tts)) if delim == token::Paren => {
575 _ => return Some(MetaItemKind::Word),
578 let mut tokens = delimited.into_trees().peekable();
579 let mut result = Vec::new();
580 while let Some(..) = tokens.peek() {
581 let item = NestedMetaItem::from_tokens(&mut tokens)?;
583 match tokens.next() {
584 None | Some(TokenTree::Token(_, Token::Comma)) => {}
588 Some(MetaItemKind::List(result))
592 impl NestedMetaItem {
593 pub fn span(&self) -> Span {
595 NestedMetaItem::MetaItem(ref item) => item.span,
596 NestedMetaItem::Literal(ref lit) => lit.span,
600 fn tokens(&self) -> TokenStream {
602 NestedMetaItem::MetaItem(ref item) => item.tokens(),
603 NestedMetaItem::Literal(ref lit) => lit.tokens(),
607 fn from_tokens<I>(tokens: &mut iter::Peekable<I>) -> Option<NestedMetaItem>
608 where I: Iterator<Item = TokenTree>,
610 if let Some(TokenTree::Token(span, token)) = tokens.peek().cloned() {
611 if let Some(lit) = Lit::from_token(&token, span, None) {
613 return Some(NestedMetaItem::Literal(lit));
617 MetaItem::from_tokens(tokens).map(NestedMetaItem::MetaItem)
621 pub trait HasAttrs: Sized {
622 fn attrs(&self) -> &[ast::Attribute];
623 fn visit_attrs<F: FnOnce(&mut Vec<ast::Attribute>)>(&mut self, f: F);
626 impl<T: HasAttrs> HasAttrs for Spanned<T> {
627 fn attrs(&self) -> &[ast::Attribute] { self.node.attrs() }
628 fn visit_attrs<F: FnOnce(&mut Vec<ast::Attribute>)>(&mut self, f: F) {
629 self.node.visit_attrs(f);
633 impl HasAttrs for Vec<Attribute> {
634 fn attrs(&self) -> &[Attribute] {
637 fn visit_attrs<F: FnOnce(&mut Vec<Attribute>)>(&mut self, f: F) {
642 impl HasAttrs for ThinVec<Attribute> {
643 fn attrs(&self) -> &[Attribute] {
646 fn visit_attrs<F: FnOnce(&mut Vec<Attribute>)>(&mut self, f: F) {
647 visit_clobber(self, |this| {
648 let mut vec = this.into();
655 impl<T: HasAttrs + 'static> HasAttrs for P<T> {
656 fn attrs(&self) -> &[Attribute] {
659 fn visit_attrs<F: FnOnce(&mut Vec<Attribute>)>(&mut self, f: F) {
660 (**self).visit_attrs(f);
664 impl HasAttrs for StmtKind {
665 fn attrs(&self) -> &[Attribute] {
667 StmtKind::Local(ref local) => local.attrs(),
668 StmtKind::Item(..) => &[],
669 StmtKind::Expr(ref expr) | StmtKind::Semi(ref expr) => expr.attrs(),
670 StmtKind::Mac(ref mac) => {
671 let (_, _, ref attrs) = **mac;
677 fn visit_attrs<F: FnOnce(&mut Vec<Attribute>)>(&mut self, f: F) {
679 StmtKind::Local(local) => local.visit_attrs(f),
680 StmtKind::Item(..) => {}
681 StmtKind::Expr(expr) => expr.visit_attrs(f),
682 StmtKind::Semi(expr) => expr.visit_attrs(f),
683 StmtKind::Mac(mac) => {
684 let (_mac, _style, attrs) = mac.deref_mut();
685 attrs.visit_attrs(f);
691 impl HasAttrs for Stmt {
692 fn attrs(&self) -> &[ast::Attribute] {
696 fn visit_attrs<F: FnOnce(&mut Vec<ast::Attribute>)>(&mut self, f: F) {
697 self.node.visit_attrs(f);
701 impl HasAttrs for GenericParam {
702 fn attrs(&self) -> &[ast::Attribute] {
706 fn visit_attrs<F: FnOnce(&mut Vec<Attribute>)>(&mut self, f: F) {
707 self.attrs.visit_attrs(f);
711 macro_rules! derive_has_attrs {
712 ($($ty:path),*) => { $(
713 impl HasAttrs for $ty {
714 fn attrs(&self) -> &[Attribute] {
718 fn visit_attrs<F: FnOnce(&mut Vec<Attribute>)>(&mut self, f: F) {
719 self.attrs.visit_attrs(f);
726 Item, Expr, Local, ast::ForeignItem, ast::StructField, ast::ImplItem, ast::TraitItem, ast::Arm,
727 ast::Field, ast::FieldPat, ast::Variant_
730 pub fn inject(mut krate: ast::Crate, parse_sess: &ParseSess, attrs: &[String]) -> ast::Crate {
731 for raw_attr in attrs {
732 let mut parser = parse::new_parser_from_source_str(
734 FileName::cli_crate_attr_source_code(&raw_attr),
738 let start_span = parser.span;
739 let (path, tokens) = panictry!(parser.parse_meta_item_unrestricted());
740 let end_span = parser.span;
741 if parser.token != token::Eof {
742 parse_sess.span_diagnostic
743 .span_err(start_span.to(end_span), "invalid crate attribute");
747 krate.attrs.push(Attribute {
749 style: AttrStyle::Inner,
752 is_sugared_doc: false,
753 span: start_span.to(end_span),