1 //! Functions dealing with attributes and meta items.
4 use crate::ast::{AttrId, AttrItem, AttrKind, AttrStyle, AttrVec, Attribute};
5 use crate::ast::{Expr, GenericParam, Item, Lit, LitKind, Local, Stmt, StmtKind};
6 use crate::ast::{MacArgs, MacDelimiter, MetaItem, MetaItemKind, NestedMetaItem};
7 use crate::ast::{Path, PathSegment};
8 use crate::mut_visit::visit_clobber;
10 use crate::token::{self, CommentKind, Token};
11 use crate::tokenstream::{DelimSpan, TokenStream, TokenTree, TreeAndSpacing};
13 use rustc_index::bit_set::GrowableBitSet;
14 use rustc_span::source_map::{BytePos, Spanned};
15 use rustc_span::symbol::{sym, Ident, Symbol};
20 pub struct MarkedAttrs(GrowableBitSet<AttrId>);
23 // We have no idea how many attributes there will be, so just
24 // initiate the vectors with 0 bits. We'll grow them as necessary.
25 pub fn new() -> Self {
26 MarkedAttrs(GrowableBitSet::new_empty())
29 pub fn mark(&mut self, attr: &Attribute) {
30 self.0.insert(attr.id);
33 pub fn is_marked(&self, attr: &Attribute) -> bool {
34 self.0.contains(attr.id)
38 pub fn is_known_lint_tool(m_item: Ident) -> bool {
39 [sym::clippy, sym::rustc].contains(&m_item.name)
43 /// Returns the `MetaItem` if `self` is a `NestedMetaItem::MetaItem`.
44 pub fn meta_item(&self) -> Option<&MetaItem> {
46 NestedMetaItem::MetaItem(ref item) => Some(item),
51 /// Returns the `Lit` if `self` is a `NestedMetaItem::Literal`s.
52 pub fn literal(&self) -> Option<&Lit> {
54 NestedMetaItem::Literal(ref lit) => Some(lit),
59 /// Returns `true` if this list item is a MetaItem with a name of `name`.
60 pub fn has_name(&self, name: Symbol) -> bool {
61 self.meta_item().map_or(false, |meta_item| meta_item.has_name(name))
64 /// For a single-segment meta item, returns its name; otherwise, returns `None`.
65 pub fn ident(&self) -> Option<Ident> {
66 self.meta_item().and_then(|meta_item| meta_item.ident())
68 pub fn name_or_empty(&self) -> Symbol {
69 self.ident().unwrap_or(Ident::invalid()).name
72 /// Gets the string value if `self` is a `MetaItem` and the `MetaItem` is a
73 /// `MetaItemKind::NameValue` variant containing a string, otherwise `None`.
74 pub fn value_str(&self) -> Option<Symbol> {
75 self.meta_item().and_then(|meta_item| meta_item.value_str())
78 /// Returns a name and single literal value tuple of the `MetaItem`.
79 pub fn name_value_literal(&self) -> Option<(Symbol, &Lit)> {
80 self.meta_item().and_then(|meta_item| {
81 meta_item.meta_item_list().and_then(|meta_item_list| {
82 if meta_item_list.len() == 1 {
83 if let Some(ident) = meta_item.ident() {
84 if let Some(lit) = meta_item_list[0].literal() {
85 return Some((ident.name, lit));
94 /// Gets a list of inner meta items from a list `MetaItem` type.
95 pub fn meta_item_list(&self) -> Option<&[NestedMetaItem]> {
96 self.meta_item().and_then(|meta_item| meta_item.meta_item_list())
99 /// Returns `true` if the variant is `MetaItem`.
100 pub fn is_meta_item(&self) -> bool {
101 self.meta_item().is_some()
104 /// Returns `true` if the variant is `Literal`.
105 pub fn is_literal(&self) -> bool {
106 self.literal().is_some()
109 /// Returns `true` if `self` is a `MetaItem` and the meta item is a word.
110 pub fn is_word(&self) -> bool {
111 self.meta_item().map_or(false, |meta_item| meta_item.is_word())
114 /// Returns `true` if `self` is a `MetaItem` and the meta item is a `ValueString`.
115 pub fn is_value_str(&self) -> bool {
116 self.value_str().is_some()
119 /// Returns `true` if `self` is a `MetaItem` and the meta item is a list.
120 pub fn is_meta_item_list(&self) -> bool {
121 self.meta_item_list().is_some()
126 pub fn has_name(&self, name: Symbol) -> bool {
128 AttrKind::Normal(ref item) => item.path == name,
129 AttrKind::DocComment(..) => false,
133 /// For a single-segment attribute, returns its name; otherwise, returns `None`.
134 pub fn ident(&self) -> Option<Ident> {
136 AttrKind::Normal(ref item) => {
137 if item.path.segments.len() == 1 {
138 Some(item.path.segments[0].ident)
143 AttrKind::DocComment(..) => None,
146 pub fn name_or_empty(&self) -> Symbol {
147 self.ident().unwrap_or(Ident::invalid()).name
150 pub fn value_str(&self) -> Option<Symbol> {
152 AttrKind::Normal(ref item) => item.meta(self.span).and_then(|meta| meta.value_str()),
153 AttrKind::DocComment(..) => None,
157 pub fn meta_item_list(&self) -> Option<Vec<NestedMetaItem>> {
159 AttrKind::Normal(ref item) => match item.meta(self.span) {
160 Some(MetaItem { kind: MetaItemKind::List(list), .. }) => Some(list),
163 AttrKind::DocComment(..) => None,
167 pub fn is_word(&self) -> bool {
168 if let AttrKind::Normal(item) = &self.kind {
169 matches!(item.args, MacArgs::Empty)
175 pub fn is_meta_item_list(&self) -> bool {
176 self.meta_item_list().is_some()
179 /// Indicates if the attribute is a `ValueString`.
180 pub fn is_value_str(&self) -> bool {
181 self.value_str().is_some()
186 /// For a single-segment meta item, returns its name; otherwise, returns `None`.
187 pub fn ident(&self) -> Option<Ident> {
188 if self.path.segments.len() == 1 { Some(self.path.segments[0].ident) } else { None }
190 pub fn name_or_empty(&self) -> Symbol {
191 self.ident().unwrap_or(Ident::invalid()).name
195 // #[attribute(name = "value")]
197 pub fn name_value_literal(&self) -> Option<&Lit> {
199 MetaItemKind::NameValue(v) => Some(v),
204 pub fn value_str(&self) -> Option<Symbol> {
206 MetaItemKind::NameValue(ref v) => match v.kind {
207 LitKind::Str(ref s, _) => Some(*s),
214 pub fn meta_item_list(&self) -> Option<&[NestedMetaItem]> {
216 MetaItemKind::List(ref l) => Some(&l[..]),
221 pub fn is_word(&self) -> bool {
223 MetaItemKind::Word => true,
228 pub fn has_name(&self, name: Symbol) -> bool {
232 pub fn is_value_str(&self) -> bool {
233 self.value_str().is_some()
236 pub fn is_meta_item_list(&self) -> bool {
237 self.meta_item_list().is_some()
242 pub fn span(&self) -> Span {
243 self.args.span().map_or(self.path.span, |args_span| self.path.span.to(args_span))
246 pub fn meta(&self, span: Span) -> Option<MetaItem> {
248 path: self.path.clone(),
249 kind: MetaItemKind::from_mac_args(&self.args)?,
256 pub fn is_doc_comment(&self) -> bool {
258 AttrKind::Normal(_) => false,
259 AttrKind::DocComment(..) => true,
263 pub fn doc_str(&self) -> Option<Symbol> {
265 AttrKind::DocComment(.., data) => Some(data),
266 AttrKind::Normal(ref item) if item.path == sym::doc => {
267 item.meta(self.span).and_then(|meta| meta.value_str())
273 pub fn get_normal_item(&self) -> &AttrItem {
275 AttrKind::Normal(ref item) => item,
276 AttrKind::DocComment(..) => panic!("unexpected doc comment"),
280 pub fn unwrap_normal_item(self) -> AttrItem {
282 AttrKind::Normal(item) => item,
283 AttrKind::DocComment(..) => panic!("unexpected doc comment"),
287 /// Extracts the MetaItem from inside this Attribute.
288 pub fn meta(&self) -> Option<MetaItem> {
290 AttrKind::Normal(ref item) => item.meta(self.span),
291 AttrKind::DocComment(..) => None,
298 pub fn mk_name_value_item_str(ident: Ident, str: Symbol, str_span: Span) -> MetaItem {
299 let lit_kind = LitKind::Str(str, ast::StrStyle::Cooked);
300 mk_name_value_item(ident, lit_kind, str_span)
303 pub fn mk_name_value_item(ident: Ident, lit_kind: LitKind, lit_span: Span) -> MetaItem {
304 let lit = Lit::from_lit_kind(lit_kind, lit_span);
305 let span = ident.span.to(lit_span);
306 MetaItem { path: Path::from_ident(ident), span, kind: MetaItemKind::NameValue(lit) }
309 pub fn mk_list_item(ident: Ident, items: Vec<NestedMetaItem>) -> MetaItem {
310 MetaItem { path: Path::from_ident(ident), span: ident.span, kind: MetaItemKind::List(items) }
313 pub fn mk_word_item(ident: Ident) -> MetaItem {
314 MetaItem { path: Path::from_ident(ident), span: ident.span, kind: MetaItemKind::Word }
317 pub fn mk_nested_word_item(ident: Ident) -> NestedMetaItem {
318 NestedMetaItem::MetaItem(mk_word_item(ident))
321 crate fn mk_attr_id() -> AttrId {
322 use std::sync::atomic::AtomicU32;
323 use std::sync::atomic::Ordering;
325 static NEXT_ATTR_ID: AtomicU32 = AtomicU32::new(0);
327 let id = NEXT_ATTR_ID.fetch_add(1, Ordering::SeqCst);
328 assert!(id != u32::MAX);
332 pub fn mk_attr(style: AttrStyle, path: Path, args: MacArgs, span: Span) -> Attribute {
333 mk_attr_from_item(style, AttrItem { path, args, tokens: None }, span)
336 pub fn mk_attr_from_item(style: AttrStyle, item: AttrItem, span: Span) -> Attribute {
337 Attribute { kind: AttrKind::Normal(item), id: mk_attr_id(), style, span }
340 /// Returns an inner attribute with the given value and span.
341 pub fn mk_attr_inner(item: MetaItem) -> Attribute {
342 mk_attr(AttrStyle::Inner, item.path, item.kind.mac_args(item.span), item.span)
345 /// Returns an outer attribute with the given value and span.
346 pub fn mk_attr_outer(item: MetaItem) -> Attribute {
347 mk_attr(AttrStyle::Outer, item.path, item.kind.mac_args(item.span), item.span)
350 pub fn mk_doc_comment(
351 comment_kind: CommentKind,
356 Attribute { kind: AttrKind::DocComment(comment_kind, data), id: mk_attr_id(), style, span }
359 pub fn list_contains_name(items: &[NestedMetaItem], name: Symbol) -> bool {
360 items.iter().any(|item| item.has_name(name))
364 fn token_trees_and_spacings(&self) -> Vec<TreeAndSpacing> {
365 let mut idents = vec![];
366 let mut last_pos = BytePos(0 as u32);
367 for (i, segment) in self.path.segments.iter().enumerate() {
368 let is_first = i == 0;
371 Span::new(last_pos, segment.ident.span.lo(), segment.ident.span.ctxt());
372 idents.push(TokenTree::token(token::ModSep, mod_sep_span).into());
374 idents.push(TokenTree::Token(Token::from_ast_ident(segment.ident)).into());
375 last_pos = segment.ident.span.hi();
377 idents.extend(self.kind.token_trees_and_spacings(self.span));
381 fn from_tokens<I>(tokens: &mut iter::Peekable<I>) -> Option<MetaItem>
383 I: Iterator<Item = TokenTree>,
385 // FIXME: Share code with `parse_path`.
386 let path = match tokens.next().map(TokenTree::uninterpolate) {
387 Some(TokenTree::Token(Token {
388 kind: kind @ (token::Ident(..) | token::ModSep),
391 let mut segments = if let token::Ident(name, _) = kind {
392 if let Some(TokenTree::Token(Token { kind: token::ModSep, .. })) = tokens.peek()
395 vec![PathSegment::from_ident(Ident::new(name, span))]
397 break 'arm Path::from_ident(Ident::new(name, span));
400 vec![PathSegment::path_root(span)]
403 if let Some(TokenTree::Token(Token { kind: token::Ident(name, _), span })) =
404 tokens.next().map(TokenTree::uninterpolate)
406 segments.push(PathSegment::from_ident(Ident::new(name, span)));
410 if let Some(TokenTree::Token(Token { kind: token::ModSep, .. })) = tokens.peek()
417 let span = span.with_hi(segments.last().unwrap().ident.span.hi());
418 Path { span, segments, tokens: None }
420 Some(TokenTree::Token(Token { kind: token::Interpolated(nt), .. })) => match *nt {
421 token::Nonterminal::NtMeta(ref item) => return item.meta(item.path.span),
422 token::Nonterminal::NtPath(ref path) => path.clone(),
427 let list_closing_paren_pos = tokens.peek().map(|tt| tt.span().hi());
428 let kind = MetaItemKind::from_tokens(tokens)?;
429 let hi = match kind {
430 MetaItemKind::NameValue(ref lit) => lit.span.hi(),
431 MetaItemKind::List(..) => list_closing_paren_pos.unwrap_or(path.span.hi()),
434 let span = path.span.with_hi(hi);
435 Some(MetaItem { path, kind, span })
440 pub fn mac_args(&self, span: Span) -> MacArgs {
442 MetaItemKind::Word => MacArgs::Empty,
443 MetaItemKind::NameValue(lit) => MacArgs::Eq(span, lit.token_tree().into()),
444 MetaItemKind::List(list) => {
445 let mut tts = Vec::new();
446 for (i, item) in list.iter().enumerate() {
448 tts.push(TokenTree::token(token::Comma, span).into());
450 tts.extend(item.token_trees_and_spacings())
453 DelimSpan::from_single(span),
454 MacDelimiter::Parenthesis,
455 TokenStream::new(tts),
461 fn token_trees_and_spacings(&self, span: Span) -> Vec<TreeAndSpacing> {
463 MetaItemKind::Word => vec![],
464 MetaItemKind::NameValue(ref lit) => {
465 vec![TokenTree::token(token::Eq, span).into(), lit.token_tree().into()]
467 MetaItemKind::List(ref list) => {
468 let mut tokens = Vec::new();
469 for (i, item) in list.iter().enumerate() {
471 tokens.push(TokenTree::token(token::Comma, span).into());
473 tokens.extend(item.token_trees_and_spacings())
476 TokenTree::Delimited(
477 DelimSpan::from_single(span),
479 TokenStream::new(tokens),
487 fn list_from_tokens(tokens: TokenStream) -> Option<MetaItemKind> {
488 let mut tokens = tokens.into_trees().peekable();
489 let mut result = Vec::new();
490 while let Some(..) = tokens.peek() {
491 let item = NestedMetaItem::from_tokens(&mut tokens)?;
493 match tokens.next() {
494 None | Some(TokenTree::Token(Token { kind: token::Comma, .. })) => {}
498 Some(MetaItemKind::List(result))
501 fn name_value_from_tokens(
502 tokens: &mut impl Iterator<Item = TokenTree>,
503 ) -> Option<MetaItemKind> {
504 match tokens.next() {
505 Some(TokenTree::Delimited(_, token::NoDelim, inner_tokens)) => {
506 MetaItemKind::name_value_from_tokens(&mut inner_tokens.trees())
508 Some(TokenTree::Token(token)) => {
509 Lit::from_token(&token).ok().map(MetaItemKind::NameValue)
515 fn from_mac_args(args: &MacArgs) -> Option<MetaItemKind> {
517 MacArgs::Delimited(_, MacDelimiter::Parenthesis, tokens) => {
518 MetaItemKind::list_from_tokens(tokens.clone())
520 MacArgs::Delimited(..) => None,
521 MacArgs::Eq(_, tokens) => {
522 assert!(tokens.len() == 1);
523 MetaItemKind::name_value_from_tokens(&mut tokens.trees())
525 MacArgs::Empty => Some(MetaItemKind::Word),
530 tokens: &mut iter::Peekable<impl Iterator<Item = TokenTree>>,
531 ) -> Option<MetaItemKind> {
532 match tokens.peek() {
533 Some(TokenTree::Delimited(_, token::Paren, inner_tokens)) => {
534 let inner_tokens = inner_tokens.clone();
536 MetaItemKind::list_from_tokens(inner_tokens)
538 Some(TokenTree::Delimited(..)) => None,
539 Some(TokenTree::Token(Token { kind: token::Eq, .. })) => {
541 MetaItemKind::name_value_from_tokens(tokens)
543 _ => Some(MetaItemKind::Word),
548 impl NestedMetaItem {
549 pub fn span(&self) -> Span {
551 NestedMetaItem::MetaItem(ref item) => item.span,
552 NestedMetaItem::Literal(ref lit) => lit.span,
556 fn token_trees_and_spacings(&self) -> Vec<TreeAndSpacing> {
558 NestedMetaItem::MetaItem(ref item) => item.token_trees_and_spacings(),
559 NestedMetaItem::Literal(ref lit) => vec![lit.token_tree().into()],
563 fn from_tokens<I>(tokens: &mut iter::Peekable<I>) -> Option<NestedMetaItem>
565 I: Iterator<Item = TokenTree>,
567 match tokens.peek() {
568 Some(TokenTree::Token(token)) => {
569 if let Ok(lit) = Lit::from_token(token) {
571 return Some(NestedMetaItem::Literal(lit));
574 Some(TokenTree::Delimited(_, token::NoDelim, inner_tokens)) => {
575 let inner_tokens = inner_tokens.clone();
577 return NestedMetaItem::from_tokens(&mut inner_tokens.into_trees().peekable());
581 MetaItem::from_tokens(tokens).map(NestedMetaItem::MetaItem)
585 pub trait HasAttrs: Sized {
586 fn attrs(&self) -> &[Attribute];
587 fn visit_attrs(&mut self, f: impl FnOnce(&mut Vec<Attribute>));
590 impl<T: HasAttrs> HasAttrs for Spanned<T> {
591 fn attrs(&self) -> &[Attribute] {
594 fn visit_attrs(&mut self, f: impl FnOnce(&mut Vec<Attribute>)) {
595 self.node.visit_attrs(f);
599 impl HasAttrs for Vec<Attribute> {
600 fn attrs(&self) -> &[Attribute] {
603 fn visit_attrs(&mut self, f: impl FnOnce(&mut Vec<Attribute>)) {
608 impl HasAttrs for AttrVec {
609 fn attrs(&self) -> &[Attribute] {
612 fn visit_attrs(&mut self, f: impl FnOnce(&mut Vec<Attribute>)) {
613 visit_clobber(self, |this| {
614 let mut vec = this.into();
621 impl<T: HasAttrs + 'static> HasAttrs for P<T> {
622 fn attrs(&self) -> &[Attribute] {
625 fn visit_attrs(&mut self, f: impl FnOnce(&mut Vec<Attribute>)) {
626 (**self).visit_attrs(f);
630 impl HasAttrs for StmtKind {
631 fn attrs(&self) -> &[Attribute] {
633 StmtKind::Local(ref local) => local.attrs(),
634 StmtKind::Expr(ref expr) | StmtKind::Semi(ref expr) => expr.attrs(),
635 StmtKind::Empty | StmtKind::Item(..) => &[],
636 StmtKind::MacCall(ref mac) => mac.attrs.attrs(),
640 fn visit_attrs(&mut self, f: impl FnOnce(&mut Vec<Attribute>)) {
642 StmtKind::Local(local) => local.visit_attrs(f),
643 StmtKind::Expr(expr) | StmtKind::Semi(expr) => expr.visit_attrs(f),
644 StmtKind::Empty | StmtKind::Item(..) => {}
645 StmtKind::MacCall(mac) => {
646 mac.attrs.visit_attrs(f);
652 impl HasAttrs for Stmt {
653 fn attrs(&self) -> &[ast::Attribute] {
657 fn visit_attrs(&mut self, f: impl FnOnce(&mut Vec<Attribute>)) {
658 self.kind.visit_attrs(f);
662 macro_rules! derive_has_attrs {
663 ($($ty:path),*) => { $(
664 impl HasAttrs for $ty {
665 fn attrs(&self) -> &[Attribute] {
669 fn visit_attrs(&mut self, f: impl FnOnce(&mut Vec<Attribute>)) {
670 self.attrs.visit_attrs(f);
677 Item, Expr, Local, ast::AssocItem, ast::ForeignItem, ast::StructField, ast::Arm,
678 ast::Field, ast::FieldPat, ast::Variant, ast::Param, GenericParam