src/libsyntax/parse/mod.rs

   1 // Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 //! The main parser interface
  12
  13 use ast;
  14 use codemap::CodeMap;
  15 use syntax_pos::{self, Span, FileMap};
  16 use errors::{Handler, ColorConfig, DiagnosticBuilder};
  17 use parse::parser::Parser;
  18 use parse::token::InternedString;
  19 use ptr::P;
  20 use str::char_at;
  21 use tokenstream;
  22
  23 use std::cell::RefCell;
  24 use std::iter;
  25 use std::path::{Path, PathBuf};
  26 use std::rc::Rc;
  27 use std::str;
  28
  29 pub type PResult<'a, T> = Result<T, DiagnosticBuilder<'a>>;
  30
  31 #[macro_use]
  32 pub mod parser;
  33
  34 pub mod lexer;
  35 pub mod token;
  36 pub mod attr;
  37
  38 pub mod common;
  39 pub mod classify;
  40 pub mod obsolete;
  41
  42 /// Info about a parsing session.
  43 pub struct ParseSess {
  44     pub span_diagnostic: Handler, // better be the same as the one in the reader!
  45     /// Used to determine and report recursive mod inclusions
  46     included_mod_stack: RefCell<Vec<PathBuf>>,
  47     code_map: Rc<CodeMap>,
  48 }
  49
  50 impl ParseSess {
  51     pub fn new() -> ParseSess {
  52         let cm = Rc::new(CodeMap::new());
  53         let handler = Handler::with_tty_emitter(ColorConfig::Auto,
  54                                                 true,
  55                                                 false,
  56                                                 Some(cm.clone()));
  57         ParseSess::with_span_handler(handler, cm)
  58     }
  59
  60     pub fn with_span_handler(handler: Handler, code_map: Rc<CodeMap>) -> ParseSess {
  61         ParseSess {
  62             span_diagnostic: handler,
  63             included_mod_stack: RefCell::new(vec![]),
  64             code_map: code_map
  65         }
  66     }
  67
  68     pub fn codemap(&self) -> &CodeMap {
  69         &self.code_map
  70     }
  71 }
  72
  73 // a bunch of utility functions of the form parse_<thing>_from_<source>
  74 // where <thing> includes crate, expr, item, stmt, tts, and one that
  75 // uses a HOF to parse anything, and <source> includes file and
  76 // source_str.
  77
  78 pub fn parse_crate_from_file<'a>(input: &Path,
  79                                  cfg: ast::CrateConfig,
  80                                  sess: &'a ParseSess)
  81                                  -> PResult<'a, ast::Crate> {
  82     let mut parser = new_parser_from_file(sess, cfg, input);
  83     parser.parse_crate_mod()
  84 }
  85
  86 pub fn parse_crate_attrs_from_file<'a>(input: &Path,
  87                                        cfg: ast::CrateConfig,
  88                                        sess: &'a ParseSess)
  89                                        -> PResult<'a, Vec<ast::Attribute>> {
  90     let mut parser = new_parser_from_file(sess, cfg, input);
  91     parser.parse_inner_attributes()
  92 }
  93
  94 pub fn parse_crate_from_source_str<'a>(name: String,
  95                                        source: String,
  96                                        cfg: ast::CrateConfig,
  97                                        sess: &'a ParseSess)
  98                                        -> PResult<'a, ast::Crate> {
  99     let mut p = new_parser_from_source_str(sess,
 100                                            cfg,
 101                                            name,
 102                                            source);
 103     p.parse_crate_mod()
 104 }
 105
 106 pub fn parse_crate_attrs_from_source_str<'a>(name: String,
 107                                              source: String,
 108                                              cfg: ast::CrateConfig,
 109                                              sess: &'a ParseSess)
 110                                              -> PResult<'a, Vec<ast::Attribute>> {
 111     let mut p = new_parser_from_source_str(sess,
 112                                            cfg,
 113                                            name,
 114                                            source);
 115     p.parse_inner_attributes()
 116 }
 117
 118 pub fn parse_expr_from_source_str<'a>(name: String,
 119                                       source: String,
 120                                       cfg: ast::CrateConfig,
 121                                       sess: &'a ParseSess)
 122                                       -> PResult<'a, P<ast::Expr>> {
 123     let mut p = new_parser_from_source_str(sess, cfg, name, source);
 124     p.parse_expr()
 125 }
 126
 127 /// Parses an item.
 128 ///
 129 /// Returns `Ok(Some(item))` when successful, `Ok(None)` when no item was found, and`Err`
 130 /// when a syntax error occurred.
 131 pub fn parse_item_from_source_str<'a>(name: String,
 132                                       source: String,
 133                                       cfg: ast::CrateConfig,
 134                                       sess: &'a ParseSess)
 135                                       -> PResult<'a, Option<P<ast::Item>>> {
 136     let mut p = new_parser_from_source_str(sess, cfg, name, source);
 137     p.parse_item()
 138 }
 139
 140 pub fn parse_meta_from_source_str<'a>(name: String,
 141                                       source: String,
 142                                       cfg: ast::CrateConfig,
 143                                       sess: &'a ParseSess)
 144                                       -> PResult<'a, P<ast::MetaItem>> {
 145     let mut p = new_parser_from_source_str(sess, cfg, name, source);
 146     p.parse_meta_item()
 147 }
 148
 149 pub fn parse_stmt_from_source_str<'a>(name: String,
 150                                       source: String,
 151                                       cfg: ast::CrateConfig,
 152                                       sess: &'a ParseSess)
 153                                       -> PResult<'a, Option<ast::Stmt>> {
 154     let mut p = new_parser_from_source_str(
 155         sess,
 156         cfg,
 157         name,
 158         source
 159     );
 160     p.parse_stmt()
 161 }
 162
 163 // Warning: This parses with quote_depth > 0, which is not the default.
 164 pub fn parse_tts_from_source_str<'a>(name: String,
 165                                      source: String,
 166                                      cfg: ast::CrateConfig,
 167                                      sess: &'a ParseSess)
 168                                      -> PResult<'a, Vec<tokenstream::TokenTree>> {
 169     let mut p = new_parser_from_source_str(
 170         sess,
 171         cfg,
 172         name,
 173         source
 174     );
 175     p.quote_depth += 1;
 176     // right now this is re-creating the token trees from ... token trees.
 177     p.parse_all_token_trees()
 178 }
 179
 180 // Create a new parser from a source string
 181 pub fn new_parser_from_source_str<'a>(sess: &'a ParseSess,
 182                                       cfg: ast::CrateConfig,
 183                                       name: String,
 184                                       source: String)
 185                                       -> Parser<'a> {
 186     filemap_to_parser(sess, sess.codemap().new_filemap(name, None, source), cfg)
 187 }
 188
 189 /// Create a new parser, handling errors as appropriate
 190 /// if the file doesn't exist
 191 pub fn new_parser_from_file<'a>(sess: &'a ParseSess,
 192                                 cfg: ast::CrateConfig,
 193                                 path: &Path) -> Parser<'a> {
 194     filemap_to_parser(sess, file_to_filemap(sess, path, None), cfg)
 195 }
 196
 197 /// Given a session, a crate config, a path, and a span, add
 198 /// the file at the given path to the codemap, and return a parser.
 199 /// On an error, use the given span as the source of the problem.
 200 pub fn new_sub_parser_from_file<'a>(sess: &'a ParseSess,
 201                                     cfg: ast::CrateConfig,
 202                                     path: &Path,
 203                                     owns_directory: bool,
 204                                     module_name: Option<String>,
 205                                     sp: Span) -> Parser<'a> {
 206     let mut p = filemap_to_parser(sess, file_to_filemap(sess, path, Some(sp)), cfg);
 207     p.owns_directory = owns_directory;
 208     p.root_module_name = module_name;
 209     p
 210 }
 211
 212 /// Given a filemap and config, return a parser
 213 pub fn filemap_to_parser<'a>(sess: &'a ParseSess,
 214                              filemap: Rc<FileMap>,
 215                              cfg: ast::CrateConfig) -> Parser<'a> {
 216     let end_pos = filemap.end_pos;
 217     let mut parser = tts_to_parser(sess, filemap_to_tts(sess, filemap), cfg);
 218
 219     if parser.token == token::Eof && parser.span == syntax_pos::DUMMY_SP {
 220         parser.span = syntax_pos::mk_sp(end_pos, end_pos);
 221     }
 222
 223     parser
 224 }
 225
 226 // must preserve old name for now, because quote! from the *existing*
 227 // compiler expands into it
 228 pub fn new_parser_from_tts<'a>(sess: &'a ParseSess,
 229                                cfg: ast::CrateConfig,
 230                                tts: Vec<tokenstream::TokenTree>)
 231                                -> Parser<'a> {
 232     tts_to_parser(sess, tts, cfg)
 233 }
 234
 235 pub fn new_parser_from_ts<'a>(sess: &'a ParseSess,
 236                               cfg: ast::CrateConfig,
 237                               ts: tokenstream::TokenStream)
 238                               -> Parser<'a> {
 239     tts_to_parser(sess, ts.to_tts(), cfg)
 240 }
 241
 242
 243 // base abstractions
 244
 245 /// Given a session and a path and an optional span (for error reporting),
 246 /// add the path to the session's codemap and return the new filemap.
 247 fn file_to_filemap(sess: &ParseSess, path: &Path, spanopt: Option<Span>)
 248                    -> Rc<FileMap> {
 249     match sess.codemap().load_file(path) {
 250         Ok(filemap) => filemap,
 251         Err(e) => {
 252             let msg = format!("couldn't read {:?}: {}", path.display(), e);
 253             match spanopt {
 254                 Some(sp) => panic!(sess.span_diagnostic.span_fatal(sp, &msg)),
 255                 None => panic!(sess.span_diagnostic.fatal(&msg))
 256             }
 257         }
 258     }
 259 }
 260
 261 /// Given a filemap, produce a sequence of token-trees
 262 pub fn filemap_to_tts(sess: &ParseSess, filemap: Rc<FileMap>)
 263     -> Vec<tokenstream::TokenTree> {
 264     // it appears to me that the cfg doesn't matter here... indeed,
 265     // parsing tt's probably shouldn't require a parser at all.
 266     let cfg = Vec::new();
 267     let srdr = lexer::StringReader::new(&sess.span_diagnostic, filemap);
 268     let mut p1 = Parser::new(sess, cfg, Box::new(srdr));
 269     panictry!(p1.parse_all_token_trees())
 270 }
 271
 272 /// Given tts and cfg, produce a parser
 273 pub fn tts_to_parser<'a>(sess: &'a ParseSess,
 274                          tts: Vec<tokenstream::TokenTree>,
 275                          cfg: ast::CrateConfig) -> Parser<'a> {
 276     let trdr = lexer::new_tt_reader(&sess.span_diagnostic, None, None, tts);
 277     let mut p = Parser::new(sess, cfg, Box::new(trdr));
 278     p.check_unknown_macro_variable();
 279     p
 280 }
 281
 282 /// Parse a string representing a character literal into its final form.
 283 /// Rather than just accepting/rejecting a given literal, unescapes it as
 284 /// well. Can take any slice prefixed by a character escape. Returns the
 285 /// character and the number of characters consumed.
 286 pub fn char_lit(lit: &str) -> (char, isize) {
 287     use std::char;
 288
 289     let mut chars = lit.chars();
 290     let c = match (chars.next(), chars.next()) {
 291         (Some(c), None) if c != '\\' => return (c, 1),
 292         (Some('\\'), Some(c)) => match c {
 293             '"' => Some('"'),
 294             'n' => Some('\n'),
 295             'r' => Some('\r'),
 296             't' => Some('\t'),
 297             '\\' => Some('\\'),
 298             '\'' => Some('\''),
 299             '0' => Some('\0'),
 300             _ => { None }
 301         },
 302         _ => panic!("lexer accepted invalid char escape `{}`", lit)
 303     };
 304
 305     match c {
 306         Some(x) => return (x, 2),
 307         None => { }
 308     }
 309
 310     let msg = format!("lexer should have rejected a bad character escape {}", lit);
 311     let msg2 = &msg[..];
 312
 313     fn esc(len: usize, lit: &str) -> Option<(char, isize)> {
 314         u32::from_str_radix(&lit[2..len], 16).ok()
 315         .and_then(char::from_u32)
 316         .map(|x| (x, len as isize))
 317     }
 318
 319     let unicode_escape = || -> Option<(char, isize)> {
 320         if lit.as_bytes()[2] == b'{' {
 321             let idx = lit.find('}').expect(msg2);
 322             let subslice = &lit[3..idx];
 323             u32::from_str_radix(subslice, 16).ok()
 324                 .and_then(char::from_u32)
 325                 .map(|x| (x, subslice.chars().count() as isize + 4))
 326         } else {
 327             esc(6, lit)
 328         }
 329     };
 330
 331     // Unicode escapes
 332     return match lit.as_bytes()[1] as char {
 333         'x' | 'X' => esc(4, lit),
 334         'u' => unicode_escape(),
 335         'U' => esc(10, lit),
 336         _ => None,
 337     }.expect(msg2);
 338 }
 339
 340 /// Parse a string representing a string literal into its final form. Does
 341 /// unescaping.
 342 pub fn str_lit(lit: &str) -> String {
 343     debug!("parse_str_lit: given {}", lit.escape_default());
 344     let mut res = String::with_capacity(lit.len());
 345
 346     // FIXME #8372: This could be a for-loop if it didn't borrow the iterator
 347     let error = |i| format!("lexer should have rejected {} at {}", lit, i);
 348
 349     /// Eat everything up to a non-whitespace
 350     fn eat<'a>(it: &mut iter::Peekable<str::CharIndices<'a>>) {
 351         loop {
 352             match it.peek().map(|x| x.1) {
 353                 Some(' ') | Some('\n') | Some('\r') | Some('\t') => {
 354                     it.next();
 355                 },
 356                 _ => { break; }
 357             }
 358         }
 359     }
 360
 361     let mut chars = lit.char_indices().peekable();
 362     loop {
 363         match chars.next() {
 364             Some((i, c)) => {
 365                 match c {
 366                     '\\' => {
 367                         let ch = chars.peek().unwrap_or_else(|| {
 368                             panic!("{}", error(i))
 369                         }).1;
 370
 371                         if ch == '\n' {
 372                             eat(&mut chars);
 373                         } else if ch == '\r' {
 374                             chars.next();
 375                             let ch = chars.peek().unwrap_or_else(|| {
 376                                 panic!("{}", error(i))
 377                             }).1;
 378
 379                             if ch != '\n' {
 380                                 panic!("lexer accepted bare CR");
 381                             }
 382                             eat(&mut chars);
 383                         } else {
 384                             // otherwise, a normal escape
 385                             let (c, n) = char_lit(&lit[i..]);
 386                             for _ in 0..n - 1 { // we don't need to move past the first \
 387                                 chars.next();
 388                             }
 389                             res.push(c);
 390                         }
 391                     },
 392                     '\r' => {
 393                         let ch = chars.peek().unwrap_or_else(|| {
 394                             panic!("{}", error(i))
 395                         }).1;
 396
 397                         if ch != '\n' {
 398                             panic!("lexer accepted bare CR");
 399                         }
 400                         chars.next();
 401                         res.push('\n');
 402                     }
 403                     c => res.push(c),
 404                 }
 405             },
 406             None => break
 407         }
 408     }
 409
 410     res.shrink_to_fit(); // probably not going to do anything, unless there was an escape.
 411     debug!("parse_str_lit: returning {}", res);
 412     res
 413 }
 414
 415 /// Parse a string representing a raw string literal into its final form. The
 416 /// only operation this does is convert embedded CRLF into a single LF.
 417 pub fn raw_str_lit(lit: &str) -> String {
 418     debug!("raw_str_lit: given {}", lit.escape_default());
 419     let mut res = String::with_capacity(lit.len());
 420
 421     // FIXME #8372: This could be a for-loop if it didn't borrow the iterator
 422     let mut chars = lit.chars().peekable();
 423     loop {
 424         match chars.next() {
 425             Some(c) => {
 426                 if c == '\r' {
 427                     if *chars.peek().unwrap() != '\n' {
 428                         panic!("lexer accepted bare CR");
 429                     }
 430                     chars.next();
 431                     res.push('\n');
 432                 } else {
 433                     res.push(c);
 434                 }
 435             },
 436             None => break
 437         }
 438     }
 439
 440     res.shrink_to_fit();
 441     res
 442 }
 443
 444 // check if `s` looks like i32 or u1234 etc.
 445 fn looks_like_width_suffix(first_chars: &[char], s: &str) -> bool {
 446     s.len() > 1 &&
 447         first_chars.contains(&char_at(s, 0)) &&
 448         s[1..].chars().all(|c| '0' <= c && c <= '9')
 449 }
 450
 451 fn filtered_float_lit(data: token::InternedString, suffix: Option<&str>,
 452                       sd: &Handler, sp: Span) -> ast::LitKind {
 453     debug!("filtered_float_lit: {}, {:?}", data, suffix);
 454     match suffix.as_ref().map(|s| &**s) {
 455         Some("f32") => ast::LitKind::Float(data, ast::FloatTy::F32),
 456         Some("f64") => ast::LitKind::Float(data, ast::FloatTy::F64),
 457         Some(suf) => {
 458             if suf.len() >= 2 && looks_like_width_suffix(&['f'], suf) {
 459                 // if it looks like a width, lets try to be helpful.
 460                 sd.struct_span_err(sp, &format!("invalid width `{}` for float literal", &suf[1..]))
 461                  .help("valid widths are 32 and 64")
 462                  .emit();
 463             } else {
 464                 sd.struct_span_err(sp, &format!("invalid suffix `{}` for float literal", suf))
 465                   .help("valid suffixes are `f32` and `f64`")
 466                   .emit();
 467             }
 468
 469             ast::LitKind::FloatUnsuffixed(data)
 470         }
 471         None => ast::LitKind::FloatUnsuffixed(data)
 472     }
 473 }
 474 pub fn float_lit(s: &str, suffix: Option<InternedString>,
 475                  sd: &Handler, sp: Span) -> ast::LitKind {
 476     debug!("float_lit: {:?}, {:?}", s, suffix);
 477     // FIXME #2252: bounds checking float literals is deferred until trans
 478     let s = s.chars().filter(|&c| c != '_').collect::<String>();
 479     let data = token::intern_and_get_ident(&s);
 480     filtered_float_lit(data, suffix.as_ref().map(|s| &**s), sd, sp)
 481 }
 482
 483 /// Parse a string representing a byte literal into its final form. Similar to `char_lit`
 484 pub fn byte_lit(lit: &str) -> (u8, usize) {
 485     let err = |i| format!("lexer accepted invalid byte literal {} step {}", lit, i);
 486
 487     if lit.len() == 1 {
 488         (lit.as_bytes()[0], 1)
 489     } else {
 490         assert!(lit.as_bytes()[0] == b'\\', err(0));
 491         let b = match lit.as_bytes()[1] {
 492             b'"' => b'"',
 493             b'n' => b'\n',
 494             b'r' => b'\r',
 495             b't' => b'\t',
 496             b'\\' => b'\\',
 497             b'\'' => b'\'',
 498             b'0' => b'\0',
 499             _ => {
 500                 match u64::from_str_radix(&lit[2..4], 16).ok() {
 501                     Some(c) =>
 502                         if c > 0xFF {
 503                             panic!(err(2))
 504                         } else {
 505                             return (c as u8, 4)
 506                         },
 507                     None => panic!(err(3))
 508                 }
 509             }
 510         };
 511         return (b, 2);
 512     }
 513 }
 514
 515 pub fn byte_str_lit(lit: &str) -> Rc<Vec<u8>> {
 516     let mut res = Vec::with_capacity(lit.len());
 517
 518     // FIXME #8372: This could be a for-loop if it didn't borrow the iterator
 519     let error = |i| format!("lexer should have rejected {} at {}", lit, i);
 520
 521     /// Eat everything up to a non-whitespace
 522     fn eat<'a, I: Iterator<Item=(usize, u8)>>(it: &mut iter::Peekable<I>) {
 523         loop {
 524             match it.peek().map(|x| x.1) {
 525                 Some(b' ') | Some(b'\n') | Some(b'\r') | Some(b'\t') => {
 526                     it.next();
 527                 },
 528                 _ => { break; }
 529             }
 530         }
 531     }
 532
 533     // byte string literals *must* be ASCII, but the escapes don't have to be
 534     let mut chars = lit.bytes().enumerate().peekable();
 535     loop {
 536         match chars.next() {
 537             Some((i, b'\\')) => {
 538                 let em = error(i);
 539                 match chars.peek().expect(&em).1 {
 540                     b'\n' => eat(&mut chars),
 541                     b'\r' => {
 542                         chars.next();
 543                         if chars.peek().expect(&em).1 != b'\n' {
 544                             panic!("lexer accepted bare CR");
 545                         }
 546                         eat(&mut chars);
 547                     }
 548                     _ => {
 549                         // otherwise, a normal escape
 550                         let (c, n) = byte_lit(&lit[i..]);
 551                         // we don't need to move past the first \
 552                         for _ in 0..n - 1 {
 553                             chars.next();
 554                         }
 555                         res.push(c);
 556                     }
 557                 }
 558             },
 559             Some((i, b'\r')) => {
 560                 let em = error(i);
 561                 if chars.peek().expect(&em).1 != b'\n' {
 562                     panic!("lexer accepted bare CR");
 563                 }
 564                 chars.next();
 565                 res.push(b'\n');
 566             }
 567             Some((_, c)) => res.push(c),
 568             None => break,
 569         }
 570     }
 571
 572     Rc::new(res)
 573 }
 574
 575 pub fn integer_lit(s: &str,
 576                    suffix: Option<InternedString>,
 577                    sd: &Handler,
 578                    sp: Span)
 579                    -> ast::LitKind {
 580     // s can only be ascii, byte indexing is fine
 581
 582     let s2 = s.chars().filter(|&c| c != '_').collect::<String>();
 583     let mut s = &s2[..];
 584
 585     debug!("integer_lit: {}, {:?}", s, suffix);
 586
 587     let mut base = 10;
 588     let orig = s;
 589     let mut ty = ast::LitIntType::Unsuffixed;
 590
 591     if char_at(s, 0) == '0' && s.len() > 1 {
 592         match char_at(s, 1) {
 593             'x' => base = 16,
 594             'o' => base = 8,
 595             'b' => base = 2,
 596             _ => { }
 597         }
 598     }
 599
 600     // 1f64 and 2f32 etc. are valid float literals.
 601     if let Some(ref suf) = suffix {
 602         if looks_like_width_suffix(&['f'], suf) {
 603             match base {
 604                 16 => sd.span_err(sp, "hexadecimal float literal is not supported"),
 605                 8 => sd.span_err(sp, "octal float literal is not supported"),
 606                 2 => sd.span_err(sp, "binary float literal is not supported"),
 607                 _ => ()
 608             }
 609             let ident = token::intern_and_get_ident(&s);
 610             return filtered_float_lit(ident, Some(&suf), sd, sp)
 611         }
 612     }
 613
 614     if base != 10 {
 615         s = &s[2..];
 616     }
 617
 618     if let Some(ref suf) = suffix {
 619         if suf.is_empty() { sd.span_bug(sp, "found empty literal suffix in Some")}
 620         ty = match &**suf {
 621             "isize" => ast::LitIntType::Signed(ast::IntTy::Is),
 622             "i8"  => ast::LitIntType::Signed(ast::IntTy::I8),
 623             "i16" => ast::LitIntType::Signed(ast::IntTy::I16),
 624             "i32" => ast::LitIntType::Signed(ast::IntTy::I32),
 625             "i64" => ast::LitIntType::Signed(ast::IntTy::I64),
 626             "usize" => ast::LitIntType::Unsigned(ast::UintTy::Us),
 627             "u8"  => ast::LitIntType::Unsigned(ast::UintTy::U8),
 628             "u16" => ast::LitIntType::Unsigned(ast::UintTy::U16),
 629             "u32" => ast::LitIntType::Unsigned(ast::UintTy::U32),
 630             "u64" => ast::LitIntType::Unsigned(ast::UintTy::U64),
 631             _ => {
 632                 // i<digits> and u<digits> look like widths, so lets
 633                 // give an error message along those lines
 634                 if looks_like_width_suffix(&['i', 'u'], suf) {
 635                     sd.struct_span_err(sp, &format!("invalid width `{}` for integer literal",
 636                                              &suf[1..]))
 637                       .help("valid widths are 8, 16, 32 and 64")
 638                       .emit();
 639                 } else {
 640                     sd.struct_span_err(sp, &format!("invalid suffix `{}` for numeric literal", suf))
 641                       .help("the suffix must be one of the integral types \
 642                              (`u32`, `isize`, etc)")
 643                       .emit();
 644                 }
 645
 646                 ty
 647             }
 648         }
 649     }
 650
 651     debug!("integer_lit: the type is {:?}, base {:?}, the new string is {:?}, the original \
 652            string was {:?}, the original suffix was {:?}", ty, base, s, orig, suffix);
 653
 654     match u64::from_str_radix(s, base) {
 655         Ok(r) => ast::LitKind::Int(r, ty),
 656         Err(_) => {
 657             // small bases are lexed as if they were base 10, e.g, the string
 658             // might be `0b10201`. This will cause the conversion above to fail,
 659             // but these cases have errors in the lexer: we don't want to emit
 660             // two errors, and we especially don't want to emit this error since
 661             // it isn't necessarily true.
 662             let already_errored = base < 10 &&
 663                 s.chars().any(|c| c.to_digit(10).map_or(false, |d| d >= base));
 664
 665             if !already_errored {
 666                 sd.span_err(sp, "int literal is too large");
 667             }
 668             ast::LitKind::Int(0, ty)
 669         }
 670     }
 671 }
 672
 673 #[cfg(test)]
 674 mod tests {
 675     use super::*;
 676     use std::rc::Rc;
 677     use syntax_pos::{Span, BytePos, Pos, NO_EXPANSION};
 678     use codemap::Spanned;
 679     use ast::{self, PatKind};
 680     use abi::Abi;
 681     use attr::{first_attr_value_str_by_name, AttrMetaMethods};
 682     use parse;
 683     use parse::parser::Parser;
 684     use parse::token::{str_to_ident};
 685     use print::pprust::item_to_string;
 686     use ptr::P;
 687     use tokenstream::{self, TokenTree};
 688     use util::parser_testing::{string_to_tts, string_to_parser};
 689     use util::parser_testing::{string_to_expr, string_to_item, string_to_stmt};
 690     use util::ThinVec;
 691
 692     // produce a syntax_pos::span
 693     fn sp(a: u32, b: u32) -> Span {
 694         Span {lo: BytePos(a), hi: BytePos(b), expn_id: NO_EXPANSION}
 695     }
 696
 697     #[test] fn path_exprs_1() {
 698         assert!(string_to_expr("a".to_string()) ==
 699                    P(ast::Expr{
 700                     id: ast::DUMMY_NODE_ID,
 701                     node: ast::ExprKind::Path(None, ast::Path {
 702                         span: sp(0, 1),
 703                         global: false,
 704                         segments: vec!(
 705                             ast::PathSegment {
 706                                 identifier: str_to_ident("a"),
 707                                 parameters: ast::PathParameters::none(),
 708                             }
 709                         ),
 710                     }),
 711                     span: sp(0, 1),
 712                     attrs: ThinVec::new(),
 713                    }))
 714     }
 715
 716     #[test] fn path_exprs_2 () {
 717         assert!(string_to_expr("::a::b".to_string()) ==
 718                    P(ast::Expr {
 719                     id: ast::DUMMY_NODE_ID,
 720                     node: ast::ExprKind::Path(None, ast::Path {
 721                             span: sp(0, 6),
 722                             global: true,
 723                             segments: vec!(
 724                                 ast::PathSegment {
 725                                     identifier: str_to_ident("a"),
 726                                     parameters: ast::PathParameters::none(),
 727                                 },
 728                                 ast::PathSegment {
 729                                     identifier: str_to_ident("b"),
 730                                     parameters: ast::PathParameters::none(),
 731                                 }
 732                             )
 733                         }),
 734                     span: sp(0, 6),
 735                     attrs: ThinVec::new(),
 736                    }))
 737     }
 738
 739     #[should_panic]
 740     #[test] fn bad_path_expr_1() {
 741         string_to_expr("::abc::def::return".to_string());
 742     }
 743
 744     // check the token-tree-ization of macros
 745     #[test]
 746     fn string_to_tts_macro () {
 747         let tts = string_to_tts("macro_rules! zip (($a)=>($a))".to_string());
 748         let tts: &[tokenstream::TokenTree] = &tts[..];
 749
 750         match (tts.len(), tts.get(0), tts.get(1), tts.get(2), tts.get(3)) {
 751             (
 752                 4,
 753                 Some(&TokenTree::Token(_, token::Ident(name_macro_rules))),
 754                 Some(&TokenTree::Token(_, token::Not)),
 755                 Some(&TokenTree::Token(_, token::Ident(name_zip))),
 756                 Some(&TokenTree::Delimited(_, ref macro_delimed)),
 757             )
 758             if name_macro_rules.name.as_str() == "macro_rules"
 759             && name_zip.name.as_str() == "zip" => {
 760                 let tts = &macro_delimed.tts[..];
 761                 match (tts.len(), tts.get(0), tts.get(1), tts.get(2)) {
 762                     (
 763                         3,
 764                         Some(&TokenTree::Delimited(_, ref first_delimed)),
 765                         Some(&TokenTree::Token(_, token::FatArrow)),
 766                         Some(&TokenTree::Delimited(_, ref second_delimed)),
 767                     )
 768                     if macro_delimed.delim == token::Paren => {
 769                         let tts = &first_delimed.tts[..];
 770                         match (tts.len(), tts.get(0), tts.get(1)) {
 771                             (
 772                                 2,
 773                                 Some(&TokenTree::Token(_, token::Dollar)),
 774                                 Some(&TokenTree::Token(_, token::Ident(ident))),
 775                             )
 776                             if first_delimed.delim == token::Paren
 777                             && ident.name.as_str() == "a" => {},
 778                             _ => panic!("value 3: {:?}", **first_delimed),
 779                         }
 780                         let tts = &second_delimed.tts[..];
 781                         match (tts.len(), tts.get(0), tts.get(1)) {
 782                             (
 783                                 2,
 784                                 Some(&TokenTree::Token(_, token::Dollar)),
 785                                 Some(&TokenTree::Token(_, token::Ident(ident))),
 786                             )
 787                             if second_delimed.delim == token::Paren
 788                             && ident.name.as_str() == "a" => {},
 789                             _ => panic!("value 4: {:?}", **second_delimed),
 790                         }
 791                     },
 792                     _ => panic!("value 2: {:?}", **macro_delimed),
 793                 }
 794             },
 795             _ => panic!("value: {:?}",tts),
 796         }
 797     }
 798
 799     #[test]
 800     fn string_to_tts_1() {
 801         let tts = string_to_tts("fn a (b : i32) { b; }".to_string());
 802
 803         let expected = vec![
 804             TokenTree::Token(sp(0, 2), token::Ident(str_to_ident("fn"))),
 805             TokenTree::Token(sp(3, 4), token::Ident(str_to_ident("a"))),
 806             TokenTree::Delimited(
 807                 sp(5, 14),
 808                 Rc::new(tokenstream::Delimited {
 809                     delim: token::DelimToken::Paren,
 810                     open_span: sp(5, 6),
 811                     tts: vec![
 812                         TokenTree::Token(sp(6, 7), token::Ident(str_to_ident("b"))),
 813                         TokenTree::Token(sp(8, 9), token::Colon),
 814                         TokenTree::Token(sp(10, 13), token::Ident(str_to_ident("i32"))),
 815                     ],
 816                     close_span: sp(13, 14),
 817                 })),
 818             TokenTree::Delimited(
 819                 sp(15, 21),
 820                 Rc::new(tokenstream::Delimited {
 821                     delim: token::DelimToken::Brace,
 822                     open_span: sp(15, 16),
 823                     tts: vec![
 824                         TokenTree::Token(sp(17, 18), token::Ident(str_to_ident("b"))),
 825                         TokenTree::Token(sp(18, 19), token::Semi),
 826                     ],
 827                     close_span: sp(20, 21),
 828                 }))
 829         ];
 830
 831         assert_eq!(tts, expected);
 832     }
 833
 834     #[test] fn ret_expr() {
 835         assert!(string_to_expr("return d".to_string()) ==
 836                    P(ast::Expr{
 837                     id: ast::DUMMY_NODE_ID,
 838                     node:ast::ExprKind::Ret(Some(P(ast::Expr{
 839                         id: ast::DUMMY_NODE_ID,
 840                         node:ast::ExprKind::Path(None, ast::Path{
 841                             span: sp(7, 8),
 842                             global: false,
 843                             segments: vec!(
 844                                 ast::PathSegment {
 845                                     identifier: str_to_ident("d"),
 846                                     parameters: ast::PathParameters::none(),
 847                                 }
 848                             ),
 849                         }),
 850                         span:sp(7,8),
 851                         attrs: ThinVec::new(),
 852                     }))),
 853                     span:sp(0,8),
 854                     attrs: ThinVec::new(),
 855                    }))
 856     }
 857
 858     #[test] fn parse_stmt_1 () {
 859         assert!(string_to_stmt("b;".to_string()) ==
 860                    Some(ast::Stmt {
 861                        node: ast::StmtKind::Expr(P(ast::Expr {
 862                            id: ast::DUMMY_NODE_ID,
 863                            node: ast::ExprKind::Path(None, ast::Path {
 864                                span:sp(0,1),
 865                                global:false,
 866                                segments: vec!(
 867                                 ast::PathSegment {
 868                                     identifier: str_to_ident("b"),
 869                                     parameters: ast::PathParameters::none(),
 870                                 }
 871                                ),
 872                             }),
 873                            span: sp(0,1),
 874                            attrs: ThinVec::new()})),
 875                        id: ast::DUMMY_NODE_ID,
 876                        span: sp(0,1)}))
 877
 878     }
 879
 880     fn parser_done(p: Parser){
 881         assert_eq!(p.token.clone(), token::Eof);
 882     }
 883
 884     #[test] fn parse_ident_pat () {
 885         let sess = ParseSess::new();
 886         let mut parser = string_to_parser(&sess, "b".to_string());
 887         assert!(panictry!(parser.parse_pat())
 888                 == P(ast::Pat{
 889                 id: ast::DUMMY_NODE_ID,
 890                 node: PatKind::Ident(ast::BindingMode::ByValue(ast::Mutability::Immutable),
 891                                     Spanned{ span:sp(0, 1),
 892                                              node: str_to_ident("b")
 893                     },
 894                                     None),
 895                 span: sp(0,1)}));
 896         parser_done(parser);
 897     }
 898
 899     // check the contents of the tt manually:
 900     #[test] fn parse_fundecl () {
 901         // this test depends on the intern order of "fn" and "i32"
 902         assert_eq!(string_to_item("fn a (b : i32) { b; }".to_string()),
 903                   Some(
 904                       P(ast::Item{ident:str_to_ident("a"),
 905                             attrs:Vec::new(),
 906                             id: ast::DUMMY_NODE_ID,
 907                             node: ast::ItemKind::Fn(P(ast::FnDecl {
 908                                 inputs: vec!(ast::Arg{
 909                                     ty: P(ast::Ty{id: ast::DUMMY_NODE_ID,
 910                                                   node: ast::TyKind::Path(None, ast::Path{
 911                                         span:sp(10,13),
 912                                         global:false,
 913                                         segments: vec!(
 914                                             ast::PathSegment {
 915                                                 identifier:
 916                                                     str_to_ident("i32"),
 917                                                 parameters: ast::PathParameters::none(),
 918                                             }
 919                                         ),
 920                                         }),
 921                                         span:sp(10,13)
 922                                     }),
 923                                     pat: P(ast::Pat {
 924                                         id: ast::DUMMY_NODE_ID,
 925                                         node: PatKind::Ident(
 926                                             ast::BindingMode::ByValue(ast::Mutability::Immutable),
 927                                                 Spanned{
 928                                                     span: sp(6,7),
 929                                                     node: str_to_ident("b")},
 930                                                 None
 931                                                     ),
 932                                             span: sp(6,7)
 933                                     }),
 934                                         id: ast::DUMMY_NODE_ID
 935                                     }),
 936                                 output: ast::FunctionRetTy::Default(sp(15, 15)),
 937                                 variadic: false
 938                             }),
 939                                     ast::Unsafety::Normal,
 940                                     ast::Constness::NotConst,
 941                                     Abi::Rust,
 942                                     ast::Generics{ // no idea on either of these:
 943                                         lifetimes: Vec::new(),
 944                                         ty_params: P::new(),
 945                                         where_clause: ast::WhereClause {
 946                                             id: ast::DUMMY_NODE_ID,
 947                                             predicates: Vec::new(),
 948                                         }
 949                                     },
 950                                     P(ast::Block {
 951                                         stmts: vec!(ast::Stmt {
 952                                             node: ast::StmtKind::Semi(P(ast::Expr{
 953                                                 id: ast::DUMMY_NODE_ID,
 954                                                 node: ast::ExprKind::Path(None,
 955                                                       ast::Path{
 956                                                         span:sp(17,18),
 957                                                         global:false,
 958                                                         segments: vec!(
 959                                                             ast::PathSegment {
 960                                                                 identifier:
 961                                                                 str_to_ident(
 962                                                                     "b"),
 963                                                                 parameters:
 964                                                                 ast::PathParameters::none(),
 965                                                             }
 966                                                         ),
 967                                                       }),
 968                                                 span: sp(17,18),
 969                                                 attrs: ThinVec::new()})),
 970                                             id: ast::DUMMY_NODE_ID,
 971                                             span: sp(17,19)}),
 972                                         id: ast::DUMMY_NODE_ID,
 973                                         rules: ast::BlockCheckMode::Default, // no idea
 974                                         span: sp(15,21),
 975                                     })),
 976                             vis: ast::Visibility::Inherited,
 977                             span: sp(0,21)})));
 978     }
 979
 980     #[test] fn parse_use() {
 981         let use_s = "use foo::bar::baz;";
 982         let vitem = string_to_item(use_s.to_string()).unwrap();
 983         let vitem_s = item_to_string(&vitem);
 984         assert_eq!(&vitem_s[..], use_s);
 985
 986         let use_s = "use foo::bar as baz;";
 987         let vitem = string_to_item(use_s.to_string()).unwrap();
 988         let vitem_s = item_to_string(&vitem);
 989         assert_eq!(&vitem_s[..], use_s);
 990     }
 991
 992     #[test] fn parse_extern_crate() {
 993         let ex_s = "extern crate foo;";
 994         let vitem = string_to_item(ex_s.to_string()).unwrap();
 995         let vitem_s = item_to_string(&vitem);
 996         assert_eq!(&vitem_s[..], ex_s);
 997
 998         let ex_s = "extern crate foo as bar;";
 999         let vitem = string_to_item(ex_s.to_string()).unwrap();
1000         let vitem_s = item_to_string(&vitem);
1001         assert_eq!(&vitem_s[..], ex_s);
1002     }
1003
1004     fn get_spans_of_pat_idents(src: &str) -> Vec<Span> {
1005         let item = string_to_item(src.to_string()).unwrap();
1006
1007         struct PatIdentVisitor {
1008             spans: Vec<Span>
1009         }
1010         impl ::visit::Visitor for PatIdentVisitor {
1011             fn visit_pat(&mut self, p: &ast::Pat) {
1012                 match p.node {
1013                     PatKind::Ident(_ , ref spannedident, _) => {
1014                         self.spans.push(spannedident.span.clone());
1015                     }
1016                     _ => {
1017                         ::visit::walk_pat(self, p);
1018                     }
1019                 }
1020             }
1021         }
1022         let mut v = PatIdentVisitor { spans: Vec::new() };
1023         ::visit::walk_item(&mut v, &item);
1024         return v.spans;
1025     }
1026
1027     #[test] fn span_of_self_arg_pat_idents_are_correct() {
1028
1029         let srcs = ["impl z { fn a (&self, &myarg: i32) {} }",
1030                     "impl z { fn a (&mut self, &myarg: i32) {} }",
1031                     "impl z { fn a (&'a self, &myarg: i32) {} }",
1032                     "impl z { fn a (self, &myarg: i32) {} }",
1033                     "impl z { fn a (self: Foo, &myarg: i32) {} }",
1034                     ];
1035
1036         for &src in &srcs {
1037             let spans = get_spans_of_pat_idents(src);
1038             let Span{ lo, hi, .. } = spans[0];
1039             assert!("self" == &src[lo.to_usize()..hi.to_usize()],
1040                     "\"{}\" != \"self\". src=\"{}\"",
1041                     &src[lo.to_usize()..hi.to_usize()], src)
1042         }
1043     }
1044
1045     #[test] fn parse_exprs () {
1046         // just make sure that they parse....
1047         string_to_expr("3 + 4".to_string());
1048         string_to_expr("a::z.froob(b,&(987+3))".to_string());
1049     }
1050
1051     #[test] fn attrs_fix_bug () {
1052         string_to_item("pub fn mk_file_writer(path: &Path, flags: &[FileFlag])
1053                    -> Result<Box<Writer>, String> {
1054     #[cfg(windows)]
1055     fn wb() -> c_int {
1056       (O_WRONLY | libc::consts::os::extra::O_BINARY) as c_int
1057     }
1058
1059     #[cfg(unix)]
1060     fn wb() -> c_int { O_WRONLY as c_int }
1061
1062     let mut fflags: c_int = wb();
1063 }".to_string());
1064     }
1065
1066     #[test] fn crlf_doc_comments() {
1067         let sess = ParseSess::new();
1068
1069         let name = "<source>".to_string();
1070         let source = "/// doc comment\r\nfn foo() {}".to_string();
1071         let item = parse_item_from_source_str(name.clone(), source, Vec::new(), &sess)
1072             .unwrap().unwrap();
1073         let doc = first_attr_value_str_by_name(&item.attrs, "doc").unwrap();
1074         assert_eq!(&doc[..], "/// doc comment");
1075
1076         let source = "/// doc comment\r\n/// line 2\r\nfn foo() {}".to_string();
1077         let item = parse_item_from_source_str(name.clone(), source, Vec::new(), &sess)
1078             .unwrap().unwrap();
1079         let docs = item.attrs.iter().filter(|a| &*a.name() == "doc")
1080                     .map(|a| a.value_str().unwrap().to_string()).collect::<Vec<_>>();
1081         let b: &[_] = &["/// doc comment".to_string(), "/// line 2".to_string()];
1082         assert_eq!(&docs[..], b);
1083
1084         let source = "/** doc comment\r\n *  with CRLF */\r\nfn foo() {}".to_string();
1085         let item = parse_item_from_source_str(name, source, Vec::new(), &sess).unwrap().unwrap();
1086         let doc = first_attr_value_str_by_name(&item.attrs, "doc").unwrap();
1087         assert_eq!(&doc[..], "/** doc comment\n *  with CRLF */");
1088     }
1089
1090     #[test]
1091     fn ttdelim_span() {
1092         let sess = ParseSess::new();
1093         let expr = parse::parse_expr_from_source_str("foo".to_string(),
1094             "foo!( fn main() { body } )".to_string(), vec![], &sess).unwrap();
1095
1096         let tts = match expr.node {
1097             ast::ExprKind::Mac(ref mac) => mac.node.tts.clone(),
1098             _ => panic!("not a macro"),
1099         };
1100
1101         let span = tts.iter().rev().next().unwrap().get_span();
1102
1103         match sess.codemap().span_to_snippet(span) {
1104             Ok(s) => assert_eq!(&s[..], "{ body }"),
1105             Err(_) => panic!("could not get snippet"),
1106         }
1107     }
1108 }