vendor/rustc-ap-rustc_expand/src/proc_macro_server.rs

   1 use crate::base::ExtCtxt;
   2
   3 use rustc_ast as ast;
   4 use rustc_ast::token;
   5 use rustc_ast::tokenstream::{self, CanSynthesizeMissingTokens};
   6 use rustc_ast::tokenstream::{DelimSpan, Spacing::*, TokenStream, TreeAndSpacing};
   7 use rustc_ast_pretty::pprust;
   8 use rustc_data_structures::sync::Lrc;
   9 use rustc_errors::Diagnostic;
  10 use rustc_parse::lexer::nfc_normalize;
  11 use rustc_parse::{nt_to_tokenstream, parse_stream_from_source_str};
  12 use rustc_session::parse::ParseSess;
  13 use rustc_span::symbol::{self, kw, sym, Symbol};
  14 use rustc_span::{BytePos, FileName, MultiSpan, Pos, SourceFile, Span};
  15
  16 use pm::bridge::{server, TokenTree};
  17 use pm::{Delimiter, Level, LineColumn, Spacing};
  18 use std::ops::Bound;
  19 use std::{ascii, panic};
  20
  21 trait FromInternal<T> {
  22     fn from_internal(x: T) -> Self;
  23 }
  24
  25 trait ToInternal<T> {
  26     fn to_internal(self) -> T;
  27 }
  28
  29 impl FromInternal<token::DelimToken> for Delimiter {
  30     fn from_internal(delim: token::DelimToken) -> Delimiter {
  31         match delim {
  32             token::Paren => Delimiter::Parenthesis,
  33             token::Brace => Delimiter::Brace,
  34             token::Bracket => Delimiter::Bracket,
  35             token::NoDelim => Delimiter::None,
  36         }
  37     }
  38 }
  39
  40 impl ToInternal<token::DelimToken> for Delimiter {
  41     fn to_internal(self) -> token::DelimToken {
  42         match self {
  43             Delimiter::Parenthesis => token::Paren,
  44             Delimiter::Brace => token::Brace,
  45             Delimiter::Bracket => token::Bracket,
  46             Delimiter::None => token::NoDelim,
  47         }
  48     }
  49 }
  50
  51 impl FromInternal<(TreeAndSpacing, &'_ ParseSess, &'_ mut Vec<Self>)>
  52     for TokenTree<Group, Punct, Ident, Literal>
  53 {
  54     fn from_internal(
  55         ((tree, spacing), sess, stack): (TreeAndSpacing, &ParseSess, &mut Vec<Self>),
  56     ) -> Self {
  57         use rustc_ast::token::*;
  58
  59         let joint = spacing == Joint;
  60         let Token { kind, span } = match tree {
  61             tokenstream::TokenTree::Delimited(span, delim, tts) => {
  62                 let delimiter = Delimiter::from_internal(delim);
  63                 return TokenTree::Group(Group { delimiter, stream: tts, span, flatten: false });
  64             }
  65             tokenstream::TokenTree::Token(token) => token,
  66         };
  67
  68         macro_rules! tt {
  69             ($ty:ident { $($field:ident $(: $value:expr)*),+ $(,)? }) => (
  70                 TokenTree::$ty(self::$ty {
  71                     $($field $(: $value)*,)+
  72                     span,
  73                 })
  74             );
  75             ($ty:ident::$method:ident($($value:expr),*)) => (
  76                 TokenTree::$ty(self::$ty::$method($($value,)* span))
  77             );
  78         }
  79         macro_rules! op {
  80             ($a:expr) => {
  81                 tt!(Punct::new($a, joint))
  82             };
  83             ($a:expr, $b:expr) => {{
  84                 stack.push(tt!(Punct::new($b, joint)));
  85                 tt!(Punct::new($a, true))
  86             }};
  87             ($a:expr, $b:expr, $c:expr) => {{
  88                 stack.push(tt!(Punct::new($c, joint)));
  89                 stack.push(tt!(Punct::new($b, true)));
  90                 tt!(Punct::new($a, true))
  91             }};
  92         }
  93
  94         match kind {
  95             Eq => op!('='),
  96             Lt => op!('<'),
  97             Le => op!('<', '='),
  98             EqEq => op!('=', '='),
  99             Ne => op!('!', '='),
 100             Ge => op!('>', '='),
 101             Gt => op!('>'),
 102             AndAnd => op!('&', '&'),
 103             OrOr => op!('|', '|'),
 104             Not => op!('!'),
 105             Tilde => op!('~'),
 106             BinOp(Plus) => op!('+'),
 107             BinOp(Minus) => op!('-'),
 108             BinOp(Star) => op!('*'),
 109             BinOp(Slash) => op!('/'),
 110             BinOp(Percent) => op!('%'),
 111             BinOp(Caret) => op!('^'),
 112             BinOp(And) => op!('&'),
 113             BinOp(Or) => op!('|'),
 114             BinOp(Shl) => op!('<', '<'),
 115             BinOp(Shr) => op!('>', '>'),
 116             BinOpEq(Plus) => op!('+', '='),
 117             BinOpEq(Minus) => op!('-', '='),
 118             BinOpEq(Star) => op!('*', '='),
 119             BinOpEq(Slash) => op!('/', '='),
 120             BinOpEq(Percent) => op!('%', '='),
 121             BinOpEq(Caret) => op!('^', '='),
 122             BinOpEq(And) => op!('&', '='),
 123             BinOpEq(Or) => op!('|', '='),
 124             BinOpEq(Shl) => op!('<', '<', '='),
 125             BinOpEq(Shr) => op!('>', '>', '='),
 126             At => op!('@'),
 127             Dot => op!('.'),
 128             DotDot => op!('.', '.'),
 129             DotDotDot => op!('.', '.', '.'),
 130             DotDotEq => op!('.', '.', '='),
 131             Comma => op!(','),
 132             Semi => op!(';'),
 133             Colon => op!(':'),
 134             ModSep => op!(':', ':'),
 135             RArrow => op!('-', '>'),
 136             LArrow => op!('<', '-'),
 137             FatArrow => op!('=', '>'),
 138             Pound => op!('#'),
 139             Dollar => op!('$'),
 140             Question => op!('?'),
 141             SingleQuote => op!('\''),
 142
 143             Ident(name, false) if name == kw::DollarCrate => tt!(Ident::dollar_crate()),
 144             Ident(name, is_raw) => tt!(Ident::new(sess, name, is_raw)),
 145             Lifetime(name) => {
 146                 let ident = symbol::Ident::new(name, span).without_first_quote();
 147                 stack.push(tt!(Ident::new(sess, ident.name, false)));
 148                 tt!(Punct::new('\'', true))
 149             }
 150             Literal(lit) => tt!(Literal { lit }),
 151             DocComment(_, attr_style, data) => {
 152                 let mut escaped = String::new();
 153                 for ch in data.as_str().chars() {
 154                     escaped.extend(ch.escape_debug());
 155                 }
 156                 let stream = vec![
 157                     Ident(sym::doc, false),
 158                     Eq,
 159                     TokenKind::lit(token::Str, Symbol::intern(&escaped), None),
 160                 ]
 161                 .into_iter()
 162                 .map(|kind| tokenstream::TokenTree::token(kind, span))
 163                 .collect();
 164                 stack.push(TokenTree::Group(Group {
 165                     delimiter: Delimiter::Bracket,
 166                     stream,
 167                     span: DelimSpan::from_single(span),
 168                     flatten: false,
 169                 }));
 170                 if attr_style == ast::AttrStyle::Inner {
 171                     stack.push(tt!(Punct::new('!', false)));
 172                 }
 173                 tt!(Punct::new('#', false))
 174             }
 175
 176             Interpolated(nt) => {
 177                 if let Some((name, is_raw)) =
 178                     nt.ident_name_compatibility_hack(span, sess.source_map())
 179                 {
 180                     TokenTree::Ident(Ident::new(sess, name.name, is_raw, name.span))
 181                 } else {
 182                     let stream = nt_to_tokenstream(&nt, sess, CanSynthesizeMissingTokens::No);
 183                     TokenTree::Group(Group {
 184                         delimiter: Delimiter::None,
 185                         stream,
 186                         span: DelimSpan::from_single(span),
 187                         flatten: nt.pretty_printing_compatibility_hack(),
 188                     })
 189                 }
 190             }
 191
 192             OpenDelim(..) | CloseDelim(..) => unreachable!(),
 193             Eof => unreachable!(),
 194         }
 195     }
 196 }
 197
 198 impl ToInternal<TokenStream> for TokenTree<Group, Punct, Ident, Literal> {
 199     fn to_internal(self) -> TokenStream {
 200         use rustc_ast::token::*;
 201
 202         let (ch, joint, span) = match self {
 203             TokenTree::Punct(Punct { ch, joint, span }) => (ch, joint, span),
 204             TokenTree::Group(Group { delimiter, stream, span, .. }) => {
 205                 return tokenstream::TokenTree::Delimited(span, delimiter.to_internal(), stream)
 206                     .into();
 207             }
 208             TokenTree::Ident(self::Ident { sym, is_raw, span }) => {
 209                 return tokenstream::TokenTree::token(Ident(sym, is_raw), span).into();
 210             }
 211             TokenTree::Literal(self::Literal {
 212                 lit: token::Lit { kind: token::Integer, symbol, suffix },
 213                 span,
 214             }) if symbol.as_str().starts_with('-') => {
 215                 let minus = BinOp(BinOpToken::Minus);
 216                 let symbol = Symbol::intern(&symbol.as_str()[1..]);
 217                 let integer = TokenKind::lit(token::Integer, symbol, suffix);
 218                 let a = tokenstream::TokenTree::token(minus, span);
 219                 let b = tokenstream::TokenTree::token(integer, span);
 220                 return vec![a, b].into_iter().collect();
 221             }
 222             TokenTree::Literal(self::Literal {
 223                 lit: token::Lit { kind: token::Float, symbol, suffix },
 224                 span,
 225             }) if symbol.as_str().starts_with('-') => {
 226                 let minus = BinOp(BinOpToken::Minus);
 227                 let symbol = Symbol::intern(&symbol.as_str()[1..]);
 228                 let float = TokenKind::lit(token::Float, symbol, suffix);
 229                 let a = tokenstream::TokenTree::token(minus, span);
 230                 let b = tokenstream::TokenTree::token(float, span);
 231                 return vec![a, b].into_iter().collect();
 232             }
 233             TokenTree::Literal(self::Literal { lit, span }) => {
 234                 return tokenstream::TokenTree::token(Literal(lit), span).into();
 235             }
 236         };
 237
 238         let kind = match ch {
 239             '=' => Eq,
 240             '<' => Lt,
 241             '>' => Gt,
 242             '!' => Not,
 243             '~' => Tilde,
 244             '+' => BinOp(Plus),
 245             '-' => BinOp(Minus),
 246             '*' => BinOp(Star),
 247             '/' => BinOp(Slash),
 248             '%' => BinOp(Percent),
 249             '^' => BinOp(Caret),
 250             '&' => BinOp(And),
 251             '|' => BinOp(Or),
 252             '@' => At,
 253             '.' => Dot,
 254             ',' => Comma,
 255             ';' => Semi,
 256             ':' => Colon,
 257             '#' => Pound,
 258             '$' => Dollar,
 259             '?' => Question,
 260             '\'' => SingleQuote,
 261             _ => unreachable!(),
 262         };
 263
 264         let tree = tokenstream::TokenTree::token(kind, span);
 265         TokenStream::new(vec![(tree, if joint { Joint } else { Alone })])
 266     }
 267 }
 268
 269 impl ToInternal<rustc_errors::Level> for Level {
 270     fn to_internal(self) -> rustc_errors::Level {
 271         match self {
 272             Level::Error => rustc_errors::Level::Error,
 273             Level::Warning => rustc_errors::Level::Warning,
 274             Level::Note => rustc_errors::Level::Note,
 275             Level::Help => rustc_errors::Level::Help,
 276             _ => unreachable!("unknown proc_macro::Level variant: {:?}", self),
 277         }
 278     }
 279 }
 280
 281 pub struct FreeFunctions;
 282
 283 #[derive(Clone)]
 284 pub struct TokenStreamIter {
 285     cursor: tokenstream::Cursor,
 286     stack: Vec<TokenTree<Group, Punct, Ident, Literal>>,
 287 }
 288
 289 #[derive(Clone)]
 290 pub struct Group {
 291     delimiter: Delimiter,
 292     stream: TokenStream,
 293     span: DelimSpan,
 294     /// A hack used to pass AST fragments to attribute and derive macros
 295     /// as a single nonterminal token instead of a token stream.
 296     /// FIXME: It needs to be removed, but there are some compatibility issues (see #73345).
 297     flatten: bool,
 298 }
 299
 300 #[derive(Copy, Clone, PartialEq, Eq, Hash)]
 301 pub struct Punct {
 302     ch: char,
 303     // NB. not using `Spacing` here because it doesn't implement `Hash`.
 304     joint: bool,
 305     span: Span,
 306 }
 307
 308 impl Punct {
 309     fn new(ch: char, joint: bool, span: Span) -> Punct {
 310         const LEGAL_CHARS: &[char] = &[
 311             '=', '<', '>', '!', '~', '+', '-', '*', '/', '%', '^', '&', '|', '@', '.', ',', ';',
 312             ':', '#', '$', '?', '\'',
 313         ];
 314         if !LEGAL_CHARS.contains(&ch) {
 315             panic!("unsupported character `{:?}`", ch)
 316         }
 317         Punct { ch, joint, span }
 318     }
 319 }
 320
 321 #[derive(Copy, Clone, PartialEq, Eq, Hash)]
 322 pub struct Ident {
 323     sym: Symbol,
 324     is_raw: bool,
 325     span: Span,
 326 }
 327
 328 impl Ident {
 329     fn new(sess: &ParseSess, sym: Symbol, is_raw: bool, span: Span) -> Ident {
 330         let sym = nfc_normalize(&sym.as_str());
 331         let string = sym.as_str();
 332         if !rustc_lexer::is_ident(&string) {
 333             panic!("`{:?}` is not a valid identifier", string)
 334         }
 335         if is_raw && !sym.can_be_raw() {
 336             panic!("`{}` cannot be a raw identifier", string);
 337         }
 338         sess.symbol_gallery.insert(sym, span);
 339         Ident { sym, is_raw, span }
 340     }
 341     fn dollar_crate(span: Span) -> Ident {
 342         // `$crate` is accepted as an ident only if it comes from the compiler.
 343         Ident { sym: kw::DollarCrate, is_raw: false, span }
 344     }
 345 }
 346
 347 // FIXME(eddyb) `Literal` should not expose internal `Debug` impls.
 348 #[derive(Clone, Debug)]
 349 pub struct Literal {
 350     lit: token::Lit,
 351     span: Span,
 352 }
 353
 354 pub(crate) struct Rustc<'a> {
 355     sess: &'a ParseSess,
 356     def_site: Span,
 357     call_site: Span,
 358     mixed_site: Span,
 359     span_debug: bool,
 360 }
 361
 362 impl<'a> Rustc<'a> {
 363     pub fn new(cx: &'a ExtCtxt<'_>) -> Self {
 364         let expn_data = cx.current_expansion.id.expn_data();
 365         Rustc {
 366             sess: &cx.sess.parse_sess,
 367             def_site: cx.with_def_site_ctxt(expn_data.def_site),
 368             call_site: cx.with_call_site_ctxt(expn_data.call_site),
 369             mixed_site: cx.with_mixed_site_ctxt(expn_data.call_site),
 370             span_debug: cx.ecfg.span_debug,
 371         }
 372     }
 373
 374     fn lit(&mut self, kind: token::LitKind, symbol: Symbol, suffix: Option<Symbol>) -> Literal {
 375         Literal { lit: token::Lit::new(kind, symbol, suffix), span: server::Span::call_site(self) }
 376     }
 377 }
 378
 379 impl server::Types for Rustc<'_> {
 380     type FreeFunctions = FreeFunctions;
 381     type TokenStream = TokenStream;
 382     type TokenStreamBuilder = tokenstream::TokenStreamBuilder;
 383     type TokenStreamIter = TokenStreamIter;
 384     type Group = Group;
 385     type Punct = Punct;
 386     type Ident = Ident;
 387     type Literal = Literal;
 388     type SourceFile = Lrc<SourceFile>;
 389     type MultiSpan = Vec<Span>;
 390     type Diagnostic = Diagnostic;
 391     type Span = Span;
 392 }
 393
 394 impl server::FreeFunctions for Rustc<'_> {
 395     fn track_env_var(&mut self, var: &str, value: Option<&str>) {
 396         self.sess.env_depinfo.borrow_mut().insert((Symbol::intern(var), value.map(Symbol::intern)));
 397     }
 398 }
 399
 400 impl server::TokenStream for Rustc<'_> {
 401     fn new(&mut self) -> Self::TokenStream {
 402         TokenStream::default()
 403     }
 404     fn is_empty(&mut self, stream: &Self::TokenStream) -> bool {
 405         stream.is_empty()
 406     }
 407     fn from_str(&mut self, src: &str) -> Self::TokenStream {
 408         parse_stream_from_source_str(
 409             FileName::proc_macro_source_code(src),
 410             src.to_string(),
 411             self.sess,
 412             Some(self.call_site),
 413         )
 414     }
 415     fn to_string(&mut self, stream: &Self::TokenStream) -> String {
 416         pprust::tts_to_string(stream)
 417     }
 418     fn from_token_tree(
 419         &mut self,
 420         tree: TokenTree<Self::Group, Self::Punct, Self::Ident, Self::Literal>,
 421     ) -> Self::TokenStream {
 422         tree.to_internal()
 423     }
 424     fn into_iter(&mut self, stream: Self::TokenStream) -> Self::TokenStreamIter {
 425         TokenStreamIter { cursor: stream.trees(), stack: vec![] }
 426     }
 427 }
 428
 429 impl server::TokenStreamBuilder for Rustc<'_> {
 430     fn new(&mut self) -> Self::TokenStreamBuilder {
 431         tokenstream::TokenStreamBuilder::new()
 432     }
 433     fn push(&mut self, builder: &mut Self::TokenStreamBuilder, stream: Self::TokenStream) {
 434         builder.push(stream);
 435     }
 436     fn build(&mut self, builder: Self::TokenStreamBuilder) -> Self::TokenStream {
 437         builder.build()
 438     }
 439 }
 440
 441 impl server::TokenStreamIter for Rustc<'_> {
 442     fn next(
 443         &mut self,
 444         iter: &mut Self::TokenStreamIter,
 445     ) -> Option<TokenTree<Self::Group, Self::Punct, Self::Ident, Self::Literal>> {
 446         loop {
 447             let tree = iter.stack.pop().or_else(|| {
 448                 let next = iter.cursor.next_with_spacing()?;
 449                 Some(TokenTree::from_internal((next, self.sess, &mut iter.stack)))
 450             })?;
 451             // A hack used to pass AST fragments to attribute and derive macros
 452             // as a single nonterminal token instead of a token stream.
 453             // Such token needs to be "unwrapped" and not represented as a delimited group.
 454             // FIXME: It needs to be removed, but there are some compatibility issues (see #73345).
 455             if let TokenTree::Group(ref group) = tree {
 456                 if group.flatten {
 457                     iter.cursor.append(group.stream.clone());
 458                     continue;
 459                 }
 460             }
 461             return Some(tree);
 462         }
 463     }
 464 }
 465
 466 impl server::Group for Rustc<'_> {
 467     fn new(&mut self, delimiter: Delimiter, stream: Self::TokenStream) -> Self::Group {
 468         Group {
 469             delimiter,
 470             stream,
 471             span: DelimSpan::from_single(server::Span::call_site(self)),
 472             flatten: false,
 473         }
 474     }
 475     fn delimiter(&mut self, group: &Self::Group) -> Delimiter {
 476         group.delimiter
 477     }
 478     fn stream(&mut self, group: &Self::Group) -> Self::TokenStream {
 479         group.stream.clone()
 480     }
 481     fn span(&mut self, group: &Self::Group) -> Self::Span {
 482         group.span.entire()
 483     }
 484     fn span_open(&mut self, group: &Self::Group) -> Self::Span {
 485         group.span.open
 486     }
 487     fn span_close(&mut self, group: &Self::Group) -> Self::Span {
 488         group.span.close
 489     }
 490     fn set_span(&mut self, group: &mut Self::Group, span: Self::Span) {
 491         group.span = DelimSpan::from_single(span);
 492     }
 493 }
 494
 495 impl server::Punct for Rustc<'_> {
 496     fn new(&mut self, ch: char, spacing: Spacing) -> Self::Punct {
 497         Punct::new(ch, spacing == Spacing::Joint, server::Span::call_site(self))
 498     }
 499     fn as_char(&mut self, punct: Self::Punct) -> char {
 500         punct.ch
 501     }
 502     fn spacing(&mut self, punct: Self::Punct) -> Spacing {
 503         if punct.joint { Spacing::Joint } else { Spacing::Alone }
 504     }
 505     fn span(&mut self, punct: Self::Punct) -> Self::Span {
 506         punct.span
 507     }
 508     fn with_span(&mut self, punct: Self::Punct, span: Self::Span) -> Self::Punct {
 509         Punct { span, ..punct }
 510     }
 511 }
 512
 513 impl server::Ident for Rustc<'_> {
 514     fn new(&mut self, string: &str, span: Self::Span, is_raw: bool) -> Self::Ident {
 515         Ident::new(self.sess, Symbol::intern(string), is_raw, span)
 516     }
 517     fn span(&mut self, ident: Self::Ident) -> Self::Span {
 518         ident.span
 519     }
 520     fn with_span(&mut self, ident: Self::Ident, span: Self::Span) -> Self::Ident {
 521         Ident { span, ..ident }
 522     }
 523 }
 524
 525 impl server::Literal for Rustc<'_> {
 526     fn debug_kind(&mut self, literal: &Self::Literal) -> String {
 527         format!("{:?}", literal.lit.kind)
 528     }
 529     fn symbol(&mut self, literal: &Self::Literal) -> String {
 530         literal.lit.symbol.to_string()
 531     }
 532     fn suffix(&mut self, literal: &Self::Literal) -> Option<String> {
 533         literal.lit.suffix.as_ref().map(Symbol::to_string)
 534     }
 535     fn integer(&mut self, n: &str) -> Self::Literal {
 536         self.lit(token::Integer, Symbol::intern(n), None)
 537     }
 538     fn typed_integer(&mut self, n: &str, kind: &str) -> Self::Literal {
 539         self.lit(token::Integer, Symbol::intern(n), Some(Symbol::intern(kind)))
 540     }
 541     fn float(&mut self, n: &str) -> Self::Literal {
 542         self.lit(token::Float, Symbol::intern(n), None)
 543     }
 544     fn f32(&mut self, n: &str) -> Self::Literal {
 545         self.lit(token::Float, Symbol::intern(n), Some(sym::f32))
 546     }
 547     fn f64(&mut self, n: &str) -> Self::Literal {
 548         self.lit(token::Float, Symbol::intern(n), Some(sym::f64))
 549     }
 550     fn string(&mut self, string: &str) -> Self::Literal {
 551         let mut escaped = String::new();
 552         for ch in string.chars() {
 553             escaped.extend(ch.escape_debug());
 554         }
 555         self.lit(token::Str, Symbol::intern(&escaped), None)
 556     }
 557     fn character(&mut self, ch: char) -> Self::Literal {
 558         let mut escaped = String::new();
 559         escaped.extend(ch.escape_unicode());
 560         self.lit(token::Char, Symbol::intern(&escaped), None)
 561     }
 562     fn byte_string(&mut self, bytes: &[u8]) -> Self::Literal {
 563         let string = bytes
 564             .iter()
 565             .cloned()
 566             .flat_map(ascii::escape_default)
 567             .map(Into::<char>::into)
 568             .collect::<String>();
 569         self.lit(token::ByteStr, Symbol::intern(&string), None)
 570     }
 571     fn span(&mut self, literal: &Self::Literal) -> Self::Span {
 572         literal.span
 573     }
 574     fn set_span(&mut self, literal: &mut Self::Literal, span: Self::Span) {
 575         literal.span = span;
 576     }
 577     fn subspan(
 578         &mut self,
 579         literal: &Self::Literal,
 580         start: Bound<usize>,
 581         end: Bound<usize>,
 582     ) -> Option<Self::Span> {
 583         let span = literal.span;
 584         let length = span.hi().to_usize() - span.lo().to_usize();
 585
 586         let start = match start {
 587             Bound::Included(lo) => lo,
 588             Bound::Excluded(lo) => lo.checked_add(1)?,
 589             Bound::Unbounded => 0,
 590         };
 591
 592         let end = match end {
 593             Bound::Included(hi) => hi.checked_add(1)?,
 594             Bound::Excluded(hi) => hi,
 595             Bound::Unbounded => length,
 596         };
 597
 598         // Bounds check the values, preventing addition overflow and OOB spans.
 599         if start > u32::MAX as usize
 600             || end > u32::MAX as usize
 601             || (u32::MAX - start as u32) < span.lo().to_u32()
 602             || (u32::MAX - end as u32) < span.lo().to_u32()
 603             || start >= end
 604             || end > length
 605         {
 606             return None;
 607         }
 608
 609         let new_lo = span.lo() + BytePos::from_usize(start);
 610         let new_hi = span.lo() + BytePos::from_usize(end);
 611         Some(span.with_lo(new_lo).with_hi(new_hi))
 612     }
 613 }
 614
 615 impl server::SourceFile for Rustc<'_> {
 616     fn eq(&mut self, file1: &Self::SourceFile, file2: &Self::SourceFile) -> bool {
 617         Lrc::ptr_eq(file1, file2)
 618     }
 619     fn path(&mut self, file: &Self::SourceFile) -> String {
 620         match file.name {
 621             FileName::Real(ref name) => name
 622                 .local_path()
 623                 .to_str()
 624                 .expect("non-UTF8 file path in `proc_macro::SourceFile::path`")
 625                 .to_string(),
 626             _ => file.name.to_string(),
 627         }
 628     }
 629     fn is_real(&mut self, file: &Self::SourceFile) -> bool {
 630         file.is_real_file()
 631     }
 632 }
 633
 634 impl server::MultiSpan for Rustc<'_> {
 635     fn new(&mut self) -> Self::MultiSpan {
 636         vec![]
 637     }
 638     fn push(&mut self, spans: &mut Self::MultiSpan, span: Self::Span) {
 639         spans.push(span)
 640     }
 641 }
 642
 643 impl server::Diagnostic for Rustc<'_> {
 644     fn new(&mut self, level: Level, msg: &str, spans: Self::MultiSpan) -> Self::Diagnostic {
 645         let mut diag = Diagnostic::new(level.to_internal(), msg);
 646         diag.set_span(MultiSpan::from_spans(spans));
 647         diag
 648     }
 649     fn sub(
 650         &mut self,
 651         diag: &mut Self::Diagnostic,
 652         level: Level,
 653         msg: &str,
 654         spans: Self::MultiSpan,
 655     ) {
 656         diag.sub(level.to_internal(), msg, MultiSpan::from_spans(spans), None);
 657     }
 658     fn emit(&mut self, diag: Self::Diagnostic) {
 659         self.sess.span_diagnostic.emit_diagnostic(&diag);
 660     }
 661 }
 662
 663 impl server::Span for Rustc<'_> {
 664     fn debug(&mut self, span: Self::Span) -> String {
 665         if self.span_debug {
 666             format!("{:?}", span)
 667         } else {
 668             format!("{:?} bytes({}..{})", span.ctxt(), span.lo().0, span.hi().0)
 669         }
 670     }
 671     fn def_site(&mut self) -> Self::Span {
 672         self.def_site
 673     }
 674     fn call_site(&mut self) -> Self::Span {
 675         self.call_site
 676     }
 677     fn mixed_site(&mut self) -> Self::Span {
 678         self.mixed_site
 679     }
 680     fn source_file(&mut self, span: Self::Span) -> Self::SourceFile {
 681         self.sess.source_map().lookup_char_pos(span.lo()).file
 682     }
 683     fn parent(&mut self, span: Self::Span) -> Option<Self::Span> {
 684         span.parent()
 685     }
 686     fn source(&mut self, span: Self::Span) -> Self::Span {
 687         span.source_callsite()
 688     }
 689     fn start(&mut self, span: Self::Span) -> LineColumn {
 690         let loc = self.sess.source_map().lookup_char_pos(span.lo());
 691         LineColumn { line: loc.line, column: loc.col.to_usize() }
 692     }
 693     fn end(&mut self, span: Self::Span) -> LineColumn {
 694         let loc = self.sess.source_map().lookup_char_pos(span.hi());
 695         LineColumn { line: loc.line, column: loc.col.to_usize() }
 696     }
 697     fn join(&mut self, first: Self::Span, second: Self::Span) -> Option<Self::Span> {
 698         let self_loc = self.sess.source_map().lookup_char_pos(first.lo());
 699         let other_loc = self.sess.source_map().lookup_char_pos(second.lo());
 700
 701         if self_loc.file.name != other_loc.file.name {
 702             return None;
 703         }
 704
 705         Some(first.to(second))
 706     }
 707     fn resolved_at(&mut self, span: Self::Span, at: Self::Span) -> Self::Span {
 708         span.with_ctxt(at.ctxt())
 709     }
 710     fn source_text(&mut self, span: Self::Span) -> Option<String> {
 711         self.sess.source_map().span_to_snippet(span).ok()
 712     }
 713 }