src/libsyntax/attr/mod.rs

   1 //! Functions dealing with attributes and meta items
   2
   3 mod builtin;
   4
   5 pub use builtin::{
   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,
   9 };
  10 pub use IntType::*;
  11 pub use ReprAttr::*;
  12 pub use StabilityLevel::*;
  13
  14 use crate::ast;
  15 use crate::ast::{AttrId, Attribute, AttrStyle, Name, Ident, Path, PathSegment};
  16 use crate::ast::{MetaItem, MetaItemKind, NestedMetaItem, NestedMetaItemKind};
  17 use crate::ast::{Lit, LitKind, Expr, ExprKind, Item, Local, Stmt, StmtKind, GenericParam};
  18 use crate::mut_visit::visit_clobber;
  19 use crate::source_map::{BytePos, Spanned, respan, 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};
  24 use crate::ptr::P;
  25 use crate::symbol::Symbol;
  26 use crate::ThinVec;
  27 use crate::tokenstream::{TokenStream, TokenTree, DelimSpan};
  28 use crate::GLOBALS;
  29
  30 use log::debug;
  31 use syntax_pos::{FileName, Span};
  32
  33 use std::iter;
  34 use std::ops::DerefMut;
  35
  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);
  40     });
  41 }
  42
  43 pub fn is_used(attr: &Attribute) -> bool {
  44     GLOBALS.with(|globals| {
  45         globals.used_attrs.lock().contains(attr.id)
  46     })
  47 }
  48
  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);
  53     });
  54 }
  55
  56 pub fn is_known(attr: &Attribute) -> bool {
  57     GLOBALS.with(|globals| {
  58         globals.known_attrs.lock().contains(attr.id)
  59     })
  60 }
  61
  62 pub fn is_known_lint_tool(m_item: Ident) -> bool {
  63     ["clippy"].contains(&m_item.as_str().as_ref())
  64 }
  65
  66 impl NestedMetaItem {
  67     /// Returns the MetaItem if self is a NestedMetaItemKind::MetaItem.
  68     pub fn meta_item(&self) -> Option<&MetaItem> {
  69         match self.node {
  70             NestedMetaItemKind::MetaItem(ref item) => Some(item),
  71             _ => None
  72         }
  73     }
  74
  75     /// Returns the Lit if self is a NestedMetaItemKind::Literal.
  76     pub fn literal(&self) -> Option<&Lit> {
  77         match self.node {
  78             NestedMetaItemKind::Literal(ref lit) => Some(lit),
  79             _ => None
  80         }
  81     }
  82
  83     /// Returns the Span for `self`.
  84     pub fn span(&self) -> Span {
  85         self.span
  86     }
  87
  88     /// Returns `true` if this list item is a MetaItem with a name of `name`.
  89     pub fn check_name(&self, name: &str) -> bool {
  90         self.meta_item().map_or(false, |meta_item| meta_item.check_name(name))
  91     }
  92
  93     /// For a single-segment meta-item returns its name, otherwise returns `None`.
  94     pub fn ident(&self) -> Option<Ident> {
  95         self.meta_item().and_then(|meta_item| meta_item.ident())
  96     }
  97     pub fn ident_str(&self) -> Option<&str> {
  98         self.ident().map(|name| name.as_str().get())
  99     }
 100
 101     /// Gets the string value if self is a MetaItem and the MetaItem is a
 102     /// MetaItemKind::NameValue variant containing a string, otherwise None.
 103     pub fn value_str(&self) -> Option<Symbol> {
 104         self.meta_item().and_then(|meta_item| meta_item.value_str())
 105     }
 106
 107     /// Returns a name and single literal value tuple of the MetaItem.
 108     pub fn name_value_literal(&self) -> Option<(Name, &Lit)> {
 109         self.meta_item().and_then(
 110             |meta_item| meta_item.meta_item_list().and_then(
 111                 |meta_item_list| {
 112                     if meta_item_list.len() == 1 {
 113                         if let Some(ident) = meta_item.ident() {
 114                             if let Some(lit) = meta_item_list[0].literal() {
 115                                 return Some((ident.name, lit));
 116                             }
 117                         }
 118                     }
 119                     None
 120                 }))
 121     }
 122
 123     /// Gets a list of inner meta items from a list MetaItem type.
 124     pub fn meta_item_list(&self) -> Option<&[NestedMetaItem]> {
 125         self.meta_item().and_then(|meta_item| meta_item.meta_item_list())
 126     }
 127
 128     /// Returns `true` if the variant is MetaItem.
 129     pub fn is_meta_item(&self) -> bool {
 130         self.meta_item().is_some()
 131     }
 132
 133     /// Returns `true` if the variant is Literal.
 134     pub fn is_literal(&self) -> bool {
 135         self.literal().is_some()
 136     }
 137
 138     /// Returns `true` if self is a MetaItem and the meta item is a word.
 139     pub fn is_word(&self) -> bool {
 140         self.meta_item().map_or(false, |meta_item| meta_item.is_word())
 141     }
 142
 143     /// Returns `true` if self is a MetaItem and the meta item is a ValueString.
 144     pub fn is_value_str(&self) -> bool {
 145         self.value_str().is_some()
 146     }
 147
 148     /// Returns `true` if self is a MetaItem and the meta item is a list.
 149     pub fn is_meta_item_list(&self) -> bool {
 150         self.meta_item_list().is_some()
 151     }
 152 }
 153
 154 impl Attribute {
 155     /// Returns `true` if the attribute's path matches the argument. If it matches, then the
 156     /// attribute is marked as used.
 157     ///
 158     /// To check the attribute name without marking it used, use the `path` field directly.
 159     pub fn check_name(&self, name: &str) -> bool {
 160         let matches = self.path == name;
 161         if matches {
 162             mark_used(self);
 163         }
 164         matches
 165     }
 166
 167     /// For a single-segment attribute returns its name, otherwise returns `None`.
 168     pub fn ident(&self) -> Option<Ident> {
 169         if self.path.segments.len() == 1 {
 170             Some(self.path.segments[0].ident)
 171         } else {
 172             None
 173         }
 174     }
 175     pub fn ident_str(&self) -> Option<&str> {
 176         self.ident().map(|name| name.as_str().get())
 177     }
 178
 179     pub fn value_str(&self) -> Option<Symbol> {
 180         self.meta().and_then(|meta| meta.value_str())
 181     }
 182
 183     pub fn meta_item_list(&self) -> Option<Vec<NestedMetaItem>> {
 184         match self.meta() {
 185             Some(MetaItem { node: MetaItemKind::List(list), .. }) => Some(list),
 186             _ => None
 187         }
 188     }
 189
 190     pub fn is_word(&self) -> bool {
 191         self.tokens.is_empty()
 192     }
 193
 194     pub fn span(&self) -> Span {
 195         self.span
 196     }
 197
 198     pub fn is_meta_item_list(&self) -> bool {
 199         self.meta_item_list().is_some()
 200     }
 201
 202     /// Indicates if the attribute is a Value String.
 203     pub fn is_value_str(&self) -> bool {
 204         self.value_str().is_some()
 205     }
 206 }
 207
 208 impl MetaItem {
 209     /// For a single-segment meta-item returns its name, otherwise returns `None`.
 210     pub fn ident(&self) -> Option<Ident> {
 211         if self.ident.segments.len() == 1 {
 212             Some(self.ident.segments[0].ident)
 213         } else {
 214             None
 215         }
 216     }
 217     pub fn ident_str(&self) -> Option<&str> {
 218         self.ident().map(|name| name.as_str().get())
 219     }
 220
 221     // #[attribute(name = "value")]
 222     //             ^^^^^^^^^^^^^^
 223     pub fn name_value_literal(&self) -> Option<&Lit> {
 224         match &self.node {
 225             MetaItemKind::NameValue(v) => Some(v),
 226             _ => None,
 227         }
 228     }
 229
 230     pub fn value_str(&self) -> Option<Symbol> {
 231         match self.node {
 232             MetaItemKind::NameValue(ref v) => {
 233                 match v.node {
 234                     LitKind::Str(ref s, _) => Some(*s),
 235                     _ => None,
 236                 }
 237             },
 238             _ => None
 239         }
 240     }
 241
 242     pub fn meta_item_list(&self) -> Option<&[NestedMetaItem]> {
 243         match self.node {
 244             MetaItemKind::List(ref l) => Some(&l[..]),
 245             _ => None
 246         }
 247     }
 248
 249     pub fn is_word(&self) -> bool {
 250         match self.node {
 251             MetaItemKind::Word => true,
 252             _ => false,
 253         }
 254     }
 255
 256     pub fn span(&self) -> Span { self.span }
 257
 258     pub fn check_name(&self, name: &str) -> bool {
 259         self.ident == name
 260     }
 261
 262     pub fn is_value_str(&self) -> bool {
 263         self.value_str().is_some()
 264     }
 265
 266     pub fn is_meta_item_list(&self) -> bool {
 267         self.meta_item_list().is_some()
 268     }
 269 }
 270
 271 impl Attribute {
 272     /// Extracts the MetaItem from inside this Attribute.
 273     pub fn meta(&self) -> Option<MetaItem> {
 274         let mut tokens = self.tokens.trees().peekable();
 275         Some(MetaItem {
 276             ident: self.path.clone(),
 277             node: if let Some(node) = MetaItemKind::from_tokens(&mut tokens) {
 278                 if tokens.peek().is_some() {
 279                     return None;
 280                 }
 281                 node
 282             } else {
 283                 return None;
 284             },
 285             span: self.span,
 286         })
 287     }
 288
 289     pub fn parse<'a, T, F>(&self, sess: &'a ParseSess, mut f: F) -> PResult<'a, T>
 290         where F: FnMut(&mut Parser<'a>) -> PResult<'a, T>,
 291     {
 292         let mut parser = Parser::new(sess, self.tokens.clone(), None, false, false);
 293         let result = f(&mut parser)?;
 294         if parser.token != token::Eof {
 295             parser.unexpected()?;
 296         }
 297         Ok(result)
 298     }
 299
 300     pub fn parse_list<'a, T, F>(&self, sess: &'a ParseSess, mut f: F) -> PResult<'a, Vec<T>>
 301         where F: FnMut(&mut Parser<'a>) -> PResult<'a, T>,
 302     {
 303         if self.tokens.is_empty() {
 304             return Ok(Vec::new());
 305         }
 306         self.parse(sess, |parser| {
 307             parser.expect(&token::OpenDelim(token::Paren))?;
 308             let mut list = Vec::new();
 309             while !parser.eat(&token::CloseDelim(token::Paren)) {
 310                 list.push(f(parser)?);
 311                 if !parser.eat(&token::Comma) {
 312                    parser.expect(&token::CloseDelim(token::Paren))?;
 313                     break
 314                 }
 315             }
 316             Ok(list)
 317         })
 318     }
 319
 320     pub fn parse_meta<'a>(&self, sess: &'a ParseSess) -> PResult<'a, MetaItem> {
 321         Ok(MetaItem {
 322             ident: self.path.clone(),
 323             node: self.parse(sess, |parser| parser.parse_meta_item_kind())?,
 324             span: self.span,
 325         })
 326     }
 327
 328     /// Converts self to a normal #[doc="foo"] comment, if it is a
 329     /// comment like `///` or `/** */`. (Returns self unchanged for
 330     /// non-sugared doc attributes.)
 331     pub fn with_desugared_doc<T, F>(&self, f: F) -> T where
 332         F: FnOnce(&Attribute) -> T,
 333     {
 334         if self.is_sugared_doc {
 335             let comment = self.value_str().unwrap();
 336             let meta = mk_name_value_item_str(
 337                 Ident::from_str("doc"),
 338                 dummy_spanned(Symbol::intern(&strip_doc_comment_decoration(&comment.as_str()))));
 339             let mut attr = if self.style == ast::AttrStyle::Outer {
 340                 mk_attr_outer(self.span, self.id, meta)
 341             } else {
 342                 mk_attr_inner(self.span, self.id, meta)
 343             };
 344             attr.is_sugared_doc = true;
 345             f(&attr)
 346         } else {
 347             f(self)
 348         }
 349     }
 350 }
 351
 352 /* Constructors */
 353
 354 pub fn mk_name_value_item_str(ident: Ident, value: Spanned<Symbol>) -> MetaItem {
 355     let value = respan(value.span, LitKind::Str(value.node, ast::StrStyle::Cooked));
 356     mk_name_value_item(ident.span.to(value.span), ident, value)
 357 }
 358
 359 pub fn mk_name_value_item(span: Span, ident: Ident, value: ast::Lit) -> MetaItem {
 360     MetaItem { ident: Path::from_ident(ident), span, node: MetaItemKind::NameValue(value) }
 361 }
 362
 363 pub fn mk_list_item(span: Span, ident: Ident, items: Vec<NestedMetaItem>) -> MetaItem {
 364     MetaItem { ident: Path::from_ident(ident), span, node: MetaItemKind::List(items) }
 365 }
 366
 367 pub fn mk_word_item(ident: Ident) -> MetaItem {
 368     MetaItem { ident: Path::from_ident(ident), span: ident.span, node: MetaItemKind::Word }
 369 }
 370
 371 pub fn mk_nested_word_item(ident: Ident) -> NestedMetaItem {
 372     respan(ident.span, NestedMetaItemKind::MetaItem(mk_word_item(ident)))
 373 }
 374
 375 pub fn mk_attr_id() -> AttrId {
 376     use std::sync::atomic::AtomicUsize;
 377     use std::sync::atomic::Ordering;
 378
 379     static NEXT_ATTR_ID: AtomicUsize = AtomicUsize::new(0);
 380
 381     let id = NEXT_ATTR_ID.fetch_add(1, Ordering::SeqCst);
 382     assert!(id != ::std::usize::MAX);
 383     AttrId(id)
 384 }
 385
 386 /// Returns an inner attribute with the given value.
 387 pub fn mk_attr_inner(span: Span, id: AttrId, item: MetaItem) -> Attribute {
 388     mk_spanned_attr_inner(span, id, item)
 389 }
 390
 391 /// Returns an inner attribute with the given value and span.
 392 pub fn mk_spanned_attr_inner(sp: Span, id: AttrId, item: MetaItem) -> Attribute {
 393     Attribute {
 394         id,
 395         style: ast::AttrStyle::Inner,
 396         path: item.ident,
 397         tokens: item.node.tokens(item.span),
 398         is_sugared_doc: false,
 399         span: sp,
 400     }
 401 }
 402
 403 /// Returns an outer attribute with the given value.
 404 pub fn mk_attr_outer(span: Span, id: AttrId, item: MetaItem) -> Attribute {
 405     mk_spanned_attr_outer(span, id, item)
 406 }
 407
 408 /// Returns an outer attribute with the given value and span.
 409 pub fn mk_spanned_attr_outer(sp: Span, id: AttrId, item: MetaItem) -> Attribute {
 410     Attribute {
 411         id,
 412         style: ast::AttrStyle::Outer,
 413         path: item.ident,
 414         tokens: item.node.tokens(item.span),
 415         is_sugared_doc: false,
 416         span: sp,
 417     }
 418 }
 419
 420 pub fn mk_sugared_doc_attr(id: AttrId, text: Symbol, span: Span) -> Attribute {
 421     let style = doc_comment_style(&text.as_str());
 422     let lit = respan(span, LitKind::Str(text, ast::StrStyle::Cooked));
 423     Attribute {
 424         id,
 425         style,
 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,
 429         span,
 430     }
 431 }
 432
 433 pub fn list_contains_name(items: &[NestedMetaItem], name: &str) -> bool {
 434     items.iter().any(|item| {
 435         item.check_name(name)
 436     })
 437 }
 438
 439 pub fn contains_name(attrs: &[Attribute], name: &str) -> bool {
 440     attrs.iter().any(|item| {
 441         item.check_name(name)
 442     })
 443 }
 444
 445 pub fn find_by_name<'a>(attrs: &'a [Attribute], name: &str) -> Option<&'a Attribute> {
 446     attrs.iter().find(|attr| attr.check_name(name))
 447 }
 448
 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))
 452 }
 453
 454 pub fn first_attr_value_str_by_name(attrs: &[Attribute], name: &str) -> Option<Symbol> {
 455     attrs.iter()
 456         .find(|at| at.check_name(name))
 457         .and_then(|at| at.value_str())
 458 }
 459
 460 impl MetaItem {
 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.ident.segments.iter().enumerate() {
 465             let is_first = i == 0;
 466             if !is_first {
 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());
 471             }
 472             idents.push(TokenTree::Token(segment.ident.span,
 473                                          Token::from_ast_ident(segment.ident)).into());
 474             last_pos = segment.ident.span.hi();
 475         }
 476         self.node.tokens(self.span).append_to_tree_and_joint_vec(&mut idents);
 477         TokenStream::new(idents)
 478     }
 479
 480     fn from_tokens<I>(tokens: &mut iter::Peekable<I>) -> Option<MetaItem>
 481         where I: Iterator<Item = TokenTree>,
 482     {
 483         // FIXME: Share code with `parse_path`.
 484         let ident = 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() {
 489                         tokens.next();
 490                         vec![PathSegment::from_ident(ident.with_span_pos(span))]
 491                     } else {
 492                         break 'arm Path::from_ident(ident.with_span_pos(span));
 493                     }
 494                 } else {
 495                     vec![PathSegment::path_root(span)]
 496                 };
 497                 loop {
 498                     if let Some(TokenTree::Token(span,
 499                                                     Token::Ident(ident, _))) = tokens.next() {
 500                         segments.push(PathSegment::from_ident(ident.with_span_pos(span)));
 501                     } else {
 502                         return None;
 503                     }
 504                     if let Some(TokenTree::Token(_, Token::ModSep)) = tokens.peek() {
 505                         tokens.next();
 506                     } else {
 507                         break;
 508                     }
 509                 }
 510                 let span = span.with_hi(segments.last().unwrap().ident.span.hi());
 511                 Path { span, segments }
 512             }
 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(),
 517                 _ => return None,
 518             },
 519             _ => return None,
 520         };
 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(ident.span.hi()),
 526             _ => ident.span.hi(),
 527         };
 528         let span = ident.span.with_hi(hi);
 529         Some(MetaItem { ident, node, span })
 530     }
 531 }
 532
 533 impl MetaItemKind {
 534     pub fn tokens(&self, span: Span) -> TokenStream {
 535         match *self {
 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)
 541             }
 542             MetaItemKind::List(ref list) => {
 543                 let mut tokens = Vec::new();
 544                 for (i, item) in list.iter().enumerate() {
 545                     if i > 0 {
 546                         tokens.push(TokenTree::Token(span, Token::Comma).into());
 547                     }
 548                     item.node.tokens().append_to_tree_and_joint_vec(&mut tokens);
 549                 }
 550                 TokenTree::Delimited(
 551                     DelimSpan::from_single(span),
 552                     token::Paren,
 553                     TokenStream::new(tokens).into(),
 554                 ).into()
 555             }
 556         }
 557     }
 558
 559     fn from_tokens<I>(tokens: &mut iter::Peekable<I>) -> Option<MetaItemKind>
 560         where I: Iterator<Item = TokenTree>,
 561     {
 562         let delimited = match tokens.peek().cloned() {
 563             Some(TokenTree::Token(_, token::Eq)) => {
 564                 tokens.next();
 565                 return if let Some(TokenTree::Token(span, token)) = tokens.next() {
 566                     LitKind::from_token(token)
 567                         .map(|lit| MetaItemKind::NameValue(Spanned { node: lit, span: span }))
 568                 } else {
 569                     None
 570                 };
 571             }
 572             Some(TokenTree::Delimited(_, delim, ref tts)) if delim == token::Paren => {
 573                 tokens.next();
 574                 tts.clone()
 575             }
 576             _ => return Some(MetaItemKind::Word),
 577         };
 578
 579         let mut tokens = delimited.into_trees().peekable();
 580         let mut result = Vec::new();
 581         while let Some(..) = tokens.peek() {
 582             let item = NestedMetaItemKind::from_tokens(&mut tokens)?;
 583             result.push(respan(item.span(), item));
 584             match tokens.next() {
 585                 None | Some(TokenTree::Token(_, Token::Comma)) => {}
 586                 _ => return None,
 587             }
 588         }
 589         Some(MetaItemKind::List(result))
 590     }
 591 }
 592
 593 impl NestedMetaItemKind {
 594     fn span(&self) -> Span {
 595         match *self {
 596             NestedMetaItemKind::MetaItem(ref item) => item.span,
 597             NestedMetaItemKind::Literal(ref lit) => lit.span,
 598         }
 599     }
 600
 601     fn tokens(&self) -> TokenStream {
 602         match *self {
 603             NestedMetaItemKind::MetaItem(ref item) => item.tokens(),
 604             NestedMetaItemKind::Literal(ref lit) => lit.tokens(),
 605         }
 606     }
 607
 608     fn from_tokens<I>(tokens: &mut iter::Peekable<I>) -> Option<NestedMetaItemKind>
 609         where I: Iterator<Item = TokenTree>,
 610     {
 611         if let Some(TokenTree::Token(span, token)) = tokens.peek().cloned() {
 612             if let Some(node) = LitKind::from_token(token) {
 613                 tokens.next();
 614                 return Some(NestedMetaItemKind::Literal(respan(span, node)));
 615             }
 616         }
 617
 618         MetaItem::from_tokens(tokens).map(NestedMetaItemKind::MetaItem)
 619     }
 620 }
 621
 622 impl Lit {
 623     crate fn tokens(&self) -> TokenStream {
 624         TokenTree::Token(self.span, self.node.token()).into()
 625     }
 626 }
 627
 628 impl LitKind {
 629     fn token(&self) -> Token {
 630         use std::ascii;
 631
 632         match *self {
 633             LitKind::Str(string, ast::StrStyle::Cooked) => {
 634                 let escaped = string.as_str().escape_default().to_string();
 635                 Token::Literal(token::Lit::Str_(Symbol::intern(&escaped)), None)
 636             }
 637             LitKind::Str(string, ast::StrStyle::Raw(n)) => {
 638                 Token::Literal(token::Lit::StrRaw(string, n), None)
 639             }
 640             LitKind::ByteStr(ref bytes) => {
 641                 let string = bytes.iter().cloned().flat_map(ascii::escape_default)
 642                     .map(Into::<char>::into).collect::<String>();
 643                 Token::Literal(token::Lit::ByteStr(Symbol::intern(&string)), None)
 644             }
 645             LitKind::Byte(byte) => {
 646                 let string: String = ascii::escape_default(byte).map(Into::<char>::into).collect();
 647                 Token::Literal(token::Lit::Byte(Symbol::intern(&string)), None)
 648             }
 649             LitKind::Char(ch) => {
 650                 let string: String = ch.escape_default().map(Into::<char>::into).collect();
 651                 Token::Literal(token::Lit::Char(Symbol::intern(&string)), None)
 652             }
 653             LitKind::Int(n, ty) => {
 654                 let suffix = match ty {
 655                     ast::LitIntType::Unsigned(ty) => Some(Symbol::intern(ty.ty_to_string())),
 656                     ast::LitIntType::Signed(ty) => Some(Symbol::intern(ty.ty_to_string())),
 657                     ast::LitIntType::Unsuffixed => None,
 658                 };
 659                 Token::Literal(token::Lit::Integer(Symbol::intern(&n.to_string())), suffix)
 660             }
 661             LitKind::Float(symbol, ty) => {
 662                 Token::Literal(token::Lit::Float(symbol), Some(Symbol::intern(ty.ty_to_string())))
 663             }
 664             LitKind::FloatUnsuffixed(symbol) => Token::Literal(token::Lit::Float(symbol), None),
 665             LitKind::Bool(value) => Token::Ident(Ident::with_empty_ctxt(Symbol::intern(if value {
 666                 "true"
 667             } else {
 668                 "false"
 669             })), false),
 670             LitKind::Err(val) => Token::Literal(token::Lit::Err(val), None),
 671         }
 672     }
 673
 674     fn from_token(token: Token) -> Option<LitKind> {
 675         match token {
 676             Token::Ident(ident, false) if ident.name == "true" => Some(LitKind::Bool(true)),
 677             Token::Ident(ident, false) if ident.name == "false" => Some(LitKind::Bool(false)),
 678             Token::Interpolated(nt) => match *nt {
 679                 token::NtExpr(ref v) | token::NtLiteral(ref v) => match v.node {
 680                     ExprKind::Lit(ref lit) => Some(lit.node.clone()),
 681                     _ => None,
 682                 },
 683                 _ => None,
 684             },
 685             Token::Literal(lit, suf) => {
 686                 let (suffix_illegal, result) = parse::lit_token(lit, suf, None);
 687                 if suffix_illegal && suf.is_some() {
 688                     return None;
 689                 }
 690                 result
 691             }
 692             _ => None,
 693         }
 694     }
 695 }
 696
 697 pub trait HasAttrs: Sized {
 698     fn attrs(&self) -> &[ast::Attribute];
 699     fn visit_attrs<F: FnOnce(&mut Vec<ast::Attribute>)>(&mut self, f: F);
 700 }
 701
 702 impl<T: HasAttrs> HasAttrs for Spanned<T> {
 703     fn attrs(&self) -> &[ast::Attribute] { self.node.attrs() }
 704     fn visit_attrs<F: FnOnce(&mut Vec<ast::Attribute>)>(&mut self, f: F) {
 705         self.node.visit_attrs(f);
 706     }
 707 }
 708
 709 impl HasAttrs for Vec<Attribute> {
 710     fn attrs(&self) -> &[Attribute] {
 711         self
 712     }
 713     fn visit_attrs<F: FnOnce(&mut Vec<Attribute>)>(&mut self, f: F) {
 714         f(self)
 715     }
 716 }
 717
 718 impl HasAttrs for ThinVec<Attribute> {
 719     fn attrs(&self) -> &[Attribute] {
 720         self
 721     }
 722     fn visit_attrs<F: FnOnce(&mut Vec<Attribute>)>(&mut self, f: F) {
 723         visit_clobber(self, |this| {
 724             let mut vec = this.into();
 725             f(&mut vec);
 726             vec.into()
 727         });
 728     }
 729 }
 730
 731 impl<T: HasAttrs + 'static> HasAttrs for P<T> {
 732     fn attrs(&self) -> &[Attribute] {
 733         (**self).attrs()
 734     }
 735     fn visit_attrs<F: FnOnce(&mut Vec<Attribute>)>(&mut self, f: F) {
 736         (**self).visit_attrs(f);
 737     }
 738 }
 739
 740 impl HasAttrs for StmtKind {
 741     fn attrs(&self) -> &[Attribute] {
 742         match *self {
 743             StmtKind::Local(ref local) => local.attrs(),
 744             StmtKind::Item(..) => &[],
 745             StmtKind::Expr(ref expr) | StmtKind::Semi(ref expr) => expr.attrs(),
 746             StmtKind::Mac(ref mac) => {
 747                 let (_, _, ref attrs) = **mac;
 748                 attrs.attrs()
 749             }
 750         }
 751     }
 752
 753     fn visit_attrs<F: FnOnce(&mut Vec<Attribute>)>(&mut self, f: F) {
 754         match self {
 755             StmtKind::Local(local) => local.visit_attrs(f),
 756             StmtKind::Item(..) => {}
 757             StmtKind::Expr(expr) => expr.visit_attrs(f),
 758             StmtKind::Semi(expr) => expr.visit_attrs(f),
 759             StmtKind::Mac(mac) => {
 760                 let (_mac, _style, attrs) = mac.deref_mut();
 761                 attrs.visit_attrs(f);
 762             }
 763         }
 764     }
 765 }
 766
 767 impl HasAttrs for Stmt {
 768     fn attrs(&self) -> &[ast::Attribute] {
 769         self.node.attrs()
 770     }
 771
 772     fn visit_attrs<F: FnOnce(&mut Vec<ast::Attribute>)>(&mut self, f: F) {
 773         self.node.visit_attrs(f);
 774     }
 775 }
 776
 777 impl HasAttrs for GenericParam {
 778     fn attrs(&self) -> &[ast::Attribute] {
 779         &self.attrs
 780     }
 781
 782     fn visit_attrs<F: FnOnce(&mut Vec<Attribute>)>(&mut self, f: F) {
 783         self.attrs.visit_attrs(f);
 784     }
 785 }
 786
 787 macro_rules! derive_has_attrs {
 788     ($($ty:path),*) => { $(
 789         impl HasAttrs for $ty {
 790             fn attrs(&self) -> &[Attribute] {
 791                 &self.attrs
 792             }
 793
 794             fn visit_attrs<F: FnOnce(&mut Vec<Attribute>)>(&mut self, f: F) {
 795                 self.attrs.visit_attrs(f);
 796             }
 797         }
 798     )* }
 799 }
 800
 801 derive_has_attrs! {
 802     Item, Expr, Local, ast::ForeignItem, ast::StructField, ast::ImplItem, ast::TraitItem, ast::Arm,
 803     ast::Field, ast::FieldPat, ast::Variant_
 804 }
 805
 806 pub fn inject(mut krate: ast::Crate, parse_sess: &ParseSess, attrs: &[String]) -> ast::Crate {
 807     for raw_attr in attrs {
 808         let mut parser = parse::new_parser_from_source_str(
 809             parse_sess,
 810             FileName::cli_crate_attr_source_code(&raw_attr),
 811             raw_attr.clone(),
 812         );
 813
 814         let start_span = parser.span;
 815         let (path, tokens) = panictry!(parser.parse_meta_item_unrestricted());
 816         let end_span = parser.span;
 817         if parser.token != token::Eof {
 818             parse_sess.span_diagnostic
 819                 .span_err(start_span.to(end_span), "invalid crate attribute");
 820             continue;
 821         }
 822
 823         krate.attrs.push(Attribute {
 824             id: mk_attr_id(),
 825             style: AttrStyle::Inner,
 826             path,
 827             tokens,
 828             is_sugared_doc: false,
 829             span: start_span.to(end_span),
 830         });
 831     }
 832
 833     krate
 834 }
 835
 836 // APIs used by clippy and resurrected for beta
 837 impl Attribute {
 838     pub fn name(&self) -> Name {
 839         self.path.segments.last().expect("empty path in attribute").ident.name
 840     }
 841 }
 842 impl MetaItem {
 843     pub fn name(&self) -> Name {
 844         self.ident.segments.last().expect("empty path in attribute").ident.name
 845     }
 846     pub fn is_scoped(&self) -> Option<Ident> {
 847         if self.ident.segments.len() > 1 {
 848             Some(self.ident.segments[0].ident)
 849         } else {
 850             None
 851         }
 852     }
 853 }
 854 impl NestedMetaItem {
 855     pub fn word(&self) -> Option<&MetaItem> {
 856         self.meta_item().and_then(|meta_item| if meta_item.is_word() {
 857             Some(meta_item)
 858         } else {
 859             None
 860         })
 861     }
 862 }