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::{self, CrateConfig};
  14 use codemap::{CodeMap, FilePathMapping};
  15 use syntax_pos::{self, Span, FileMap, NO_EXPANSION};
  16 use errors::{Handler, ColorConfig, DiagnosticBuilder};
  17 use feature_gate::UnstableFeatures;
  18 use parse::parser::Parser;
  19 use ptr::P;
  20 use str::char_at;
  21 use symbol::Symbol;
  22 use tokenstream::{TokenStream, TokenTree};
  23
  24 use std::cell::RefCell;
  25 use std::collections::HashSet;
  26 use std::iter;
  27 use std::path::{Path, PathBuf};
  28 use std::rc::Rc;
  29 use std::str;
  30
  31 pub type PResult<'a, T> = Result<T, DiagnosticBuilder<'a>>;
  32
  33 #[macro_use]
  34 pub mod parser;
  35
  36 pub mod lexer;
  37 pub mod token;
  38 pub mod attr;
  39
  40 pub mod common;
  41 pub mod classify;
  42 pub mod obsolete;
  43
  44 /// Info about a parsing session.
  45 pub struct ParseSess {
  46     pub span_diagnostic: Handler,
  47     pub unstable_features: UnstableFeatures,
  48     pub config: CrateConfig,
  49     pub missing_fragment_specifiers: RefCell<HashSet<Span>>,
  50     /// Used to determine and report recursive mod inclusions
  51     included_mod_stack: RefCell<Vec<PathBuf>>,
  52     code_map: Rc<CodeMap>,
  53 }
  54
  55 impl ParseSess {
  56     pub fn new(file_path_mapping: FilePathMapping) -> Self {
  57         let cm = Rc::new(CodeMap::new(file_path_mapping));
  58         let handler = Handler::with_tty_emitter(ColorConfig::Auto,
  59                                                 true,
  60                                                 false,
  61                                                 Some(cm.clone()));
  62         ParseSess::with_span_handler(handler, cm)
  63     }
  64
  65     pub fn with_span_handler(handler: Handler, code_map: Rc<CodeMap>) -> ParseSess {
  66         ParseSess {
  67             span_diagnostic: handler,
  68             unstable_features: UnstableFeatures::from_environment(),
  69             config: HashSet::new(),
  70             missing_fragment_specifiers: RefCell::new(HashSet::new()),
  71             included_mod_stack: RefCell::new(vec![]),
  72             code_map: code_map
  73         }
  74     }
  75
  76     pub fn codemap(&self) -> &CodeMap {
  77         &self.code_map
  78     }
  79 }
  80
  81 #[derive(Clone)]
  82 pub struct Directory {
  83     pub path: PathBuf,
  84     pub ownership: DirectoryOwnership,
  85 }
  86
  87 #[derive(Copy, Clone)]
  88 pub enum DirectoryOwnership {
  89     Owned,
  90     UnownedViaBlock,
  91     UnownedViaMod(bool /* legacy warnings? */),
  92 }
  93
  94 // a bunch of utility functions of the form parse_<thing>_from_<source>
  95 // where <thing> includes crate, expr, item, stmt, tts, and one that
  96 // uses a HOF to parse anything, and <source> includes file and
  97 // source_str.
  98
  99 pub fn parse_crate_from_file<'a>(input: &Path, sess: &'a ParseSess) -> PResult<'a, ast::Crate> {
 100     let mut parser = new_parser_from_file(sess, input);
 101     parser.parse_crate_mod()
 102 }
 103
 104 pub fn parse_crate_attrs_from_file<'a>(input: &Path, sess: &'a ParseSess)
 105                                        -> PResult<'a, Vec<ast::Attribute>> {
 106     let mut parser = new_parser_from_file(sess, input);
 107     parser.parse_inner_attributes()
 108 }
 109
 110 pub fn parse_crate_from_source_str(name: String, source: String, sess: &ParseSess)
 111                                        -> PResult<ast::Crate> {
 112     new_parser_from_source_str(sess, name, source).parse_crate_mod()
 113 }
 114
 115 pub fn parse_crate_attrs_from_source_str(name: String, source: String, sess: &ParseSess)
 116                                              -> PResult<Vec<ast::Attribute>> {
 117     new_parser_from_source_str(sess, name, source).parse_inner_attributes()
 118 }
 119
 120 pub fn parse_expr_from_source_str(name: String, source: String, sess: &ParseSess)
 121                                       -> PResult<P<ast::Expr>> {
 122     new_parser_from_source_str(sess, name, source).parse_expr()
 123 }
 124
 125 /// Parses an item.
 126 ///
 127 /// Returns `Ok(Some(item))` when successful, `Ok(None)` when no item was found, and`Err`
 128 /// when a syntax error occurred.
 129 pub fn parse_item_from_source_str(name: String, source: String, sess: &ParseSess)
 130                                       -> PResult<Option<P<ast::Item>>> {
 131     new_parser_from_source_str(sess, name, source).parse_item()
 132 }
 133
 134 pub fn parse_meta_from_source_str(name: String, source: String, sess: &ParseSess)
 135                                       -> PResult<ast::MetaItem> {
 136     new_parser_from_source_str(sess, name, source).parse_meta_item()
 137 }
 138
 139 pub fn parse_stmt_from_source_str(name: String, source: String, sess: &ParseSess)
 140                                       -> PResult<Option<ast::Stmt>> {
 141     new_parser_from_source_str(sess, name, source).parse_stmt()
 142 }
 143
 144 pub fn parse_stream_from_source_str(name: String, source: String, sess: &ParseSess,
 145                                     override_span: Option<Span>)
 146                                     -> TokenStream {
 147     filemap_to_stream(sess, sess.codemap().new_filemap(name, source), override_span)
 148 }
 149
 150 // Create a new parser from a source string
 151 pub fn new_parser_from_source_str(sess: &ParseSess, name: String, source: String)
 152                                       -> Parser {
 153     let mut parser = filemap_to_parser(sess, sess.codemap().new_filemap(name, source));
 154     parser.recurse_into_file_modules = false;
 155     parser
 156 }
 157
 158 /// Create a new parser, handling errors as appropriate
 159 /// if the file doesn't exist
 160 pub fn new_parser_from_file<'a>(sess: &'a ParseSess, path: &Path) -> Parser<'a> {
 161     filemap_to_parser(sess, file_to_filemap(sess, path, None))
 162 }
 163
 164 /// Given a session, a crate config, a path, and a span, add
 165 /// the file at the given path to the codemap, and return a parser.
 166 /// On an error, use the given span as the source of the problem.
 167 pub fn new_sub_parser_from_file<'a>(sess: &'a ParseSess,
 168                                     path: &Path,
 169                                     directory_ownership: DirectoryOwnership,
 170                                     module_name: Option<String>,
 171                                     sp: Span) -> Parser<'a> {
 172     let mut p = filemap_to_parser(sess, file_to_filemap(sess, path, Some(sp)));
 173     p.directory.ownership = directory_ownership;
 174     p.root_module_name = module_name;
 175     p
 176 }
 177
 178 /// Given a filemap and config, return a parser
 179 pub fn filemap_to_parser(sess: & ParseSess, filemap: Rc<FileMap>, ) -> Parser {
 180     let end_pos = filemap.end_pos;
 181     let mut parser = stream_to_parser(sess, filemap_to_stream(sess, filemap, None));
 182
 183     if parser.token == token::Eof && parser.span == syntax_pos::DUMMY_SP {
 184         parser.span = Span { lo: end_pos, hi: end_pos, ctxt: NO_EXPANSION };
 185     }
 186
 187     parser
 188 }
 189
 190 // must preserve old name for now, because quote! from the *existing*
 191 // compiler expands into it
 192 pub fn new_parser_from_tts(sess: &ParseSess, tts: Vec<TokenTree>) -> Parser {
 193     stream_to_parser(sess, tts.into_iter().collect())
 194 }
 195
 196
 197 // base abstractions
 198
 199 /// Given a session and a path and an optional span (for error reporting),
 200 /// add the path to the session's codemap and return the new filemap.
 201 fn file_to_filemap(sess: &ParseSess, path: &Path, spanopt: Option<Span>)
 202                    -> Rc<FileMap> {
 203     match sess.codemap().load_file(path) {
 204         Ok(filemap) => filemap,
 205         Err(e) => {
 206             let msg = format!("couldn't read {:?}: {}", path.display(), e);
 207             match spanopt {
 208                 Some(sp) => panic!(sess.span_diagnostic.span_fatal(sp, &msg)),
 209                 None => panic!(sess.span_diagnostic.fatal(&msg))
 210             }
 211         }
 212     }
 213 }
 214
 215 /// Given a filemap, produce a sequence of token-trees
 216 pub fn filemap_to_stream(sess: &ParseSess, filemap: Rc<FileMap>, override_span: Option<Span>)
 217                          -> TokenStream {
 218     let mut srdr = lexer::StringReader::new(sess, filemap);
 219     srdr.override_span = override_span;
 220     srdr.real_token();
 221     panictry!(srdr.parse_all_token_trees())
 222 }
 223
 224 /// Given stream and the `ParseSess`, produce a parser
 225 pub fn stream_to_parser(sess: &ParseSess, stream: TokenStream) -> Parser {
 226     Parser::new(sess, stream, None, true, false)
 227 }
 228
 229 /// Parse a string representing a character literal into its final form.
 230 /// Rather than just accepting/rejecting a given literal, unescapes it as
 231 /// well. Can take any slice prefixed by a character escape. Returns the
 232 /// character and the number of characters consumed.
 233 pub fn char_lit(lit: &str) -> (char, isize) {
 234     use std::char;
 235
 236     // Handle non-escaped chars first.
 237     if lit.as_bytes()[0] != b'\\' {
 238         // If the first byte isn't '\\' it might part of a multi-byte char, so
 239         // get the char with chars().
 240         let c = lit.chars().next().unwrap();
 241         return (c, 1);
 242     }
 243
 244     // Handle escaped chars.
 245     match lit.as_bytes()[1] as char {
 246         '"' => ('"', 2),
 247         'n' => ('\n', 2),
 248         'r' => ('\r', 2),
 249         't' => ('\t', 2),
 250         '\\' => ('\\', 2),
 251         '\'' => ('\'', 2),
 252         '0' => ('\0', 2),
 253         'x' => {
 254             let v = u32::from_str_radix(&lit[2..4], 16).unwrap();
 255             let c = char::from_u32(v).unwrap();
 256             (c, 4)
 257         }
 258         'u' => {
 259             assert_eq!(lit.as_bytes()[2], b'{');
 260             let idx = lit.find('}').unwrap();
 261             let v = u32::from_str_radix(&lit[3..idx], 16).unwrap();
 262             let c = char::from_u32(v).unwrap();
 263             (c, (idx + 1) as isize)
 264         }
 265         _ => panic!("lexer should have rejected a bad character escape {}", lit)
 266     }
 267 }
 268
 269 pub fn escape_default(s: &str) -> String {
 270     s.chars().map(char::escape_default).flat_map(|x| x).collect()
 271 }
 272
 273 /// Parse a string representing a string literal into its final form. Does
 274 /// unescaping.
 275 pub fn str_lit(lit: &str) -> String {
 276     debug!("parse_str_lit: given {}", escape_default(lit));
 277     let mut res = String::with_capacity(lit.len());
 278
 279     // FIXME #8372: This could be a for-loop if it didn't borrow the iterator
 280     let error = |i| format!("lexer should have rejected {} at {}", lit, i);
 281
 282     /// Eat everything up to a non-whitespace
 283     fn eat<'a>(it: &mut iter::Peekable<str::CharIndices<'a>>) {
 284         loop {
 285             match it.peek().map(|x| x.1) {
 286                 Some(' ') | Some('\n') | Some('\r') | Some('\t') => {
 287                     it.next();
 288                 },
 289                 _ => { break; }
 290             }
 291         }
 292     }
 293
 294     let mut chars = lit.char_indices().peekable();
 295     while let Some((i, c)) = chars.next() {
 296         match c {
 297             '\\' => {
 298                 let ch = chars.peek().unwrap_or_else(|| {
 299                     panic!("{}", error(i))
 300                 }).1;
 301
 302                 if ch == '\n' {
 303                     eat(&mut chars);
 304                 } else if ch == '\r' {
 305                     chars.next();
 306                     let ch = chars.peek().unwrap_or_else(|| {
 307                         panic!("{}", error(i))
 308                     }).1;
 309
 310                     if ch != '\n' {
 311                         panic!("lexer accepted bare CR");
 312                     }
 313                     eat(&mut chars);
 314                 } else {
 315                     // otherwise, a normal escape
 316                     let (c, n) = char_lit(&lit[i..]);
 317                     for _ in 0..n - 1 { // we don't need to move past the first \
 318                         chars.next();
 319                     }
 320                     res.push(c);
 321                 }
 322             },
 323             '\r' => {
 324                 let ch = chars.peek().unwrap_or_else(|| {
 325                     panic!("{}", error(i))
 326                 }).1;
 327
 328                 if ch != '\n' {
 329                     panic!("lexer accepted bare CR");
 330                 }
 331                 chars.next();
 332                 res.push('\n');
 333             }
 334             c => res.push(c),
 335         }
 336     }
 337
 338     res.shrink_to_fit(); // probably not going to do anything, unless there was an escape.
 339     debug!("parse_str_lit: returning {}", res);
 340     res
 341 }
 342
 343 /// Parse a string representing a raw string literal into its final form. The
 344 /// only operation this does is convert embedded CRLF into a single LF.
 345 pub fn raw_str_lit(lit: &str) -> String {
 346     debug!("raw_str_lit: given {}", escape_default(lit));
 347     let mut res = String::with_capacity(lit.len());
 348
 349     let mut chars = lit.chars().peekable();
 350     while let Some(c) = chars.next() {
 351         if c == '\r' {
 352             if *chars.peek().unwrap() != '\n' {
 353                 panic!("lexer accepted bare CR");
 354             }
 355             chars.next();
 356             res.push('\n');
 357         } else {
 358             res.push(c);
 359         }
 360     }
 361
 362     res.shrink_to_fit();
 363     res
 364 }
 365
 366 // check if `s` looks like i32 or u1234 etc.
 367 fn looks_like_width_suffix(first_chars: &[char], s: &str) -> bool {
 368     s.len() > 1 &&
 369         first_chars.contains(&char_at(s, 0)) &&
 370         s[1..].chars().all(|c| '0' <= c && c <= '9')
 371 }
 372
 373 macro_rules! err {
 374     ($opt_diag:expr, |$span:ident, $diag:ident| $($body:tt)*) => {
 375         match $opt_diag {
 376             Some(($span, $diag)) => { $($body)* }
 377             None => return None,
 378         }
 379     }
 380 }
 381
 382 pub fn lit_token(lit: token::Lit, suf: Option<Symbol>, diag: Option<(Span, &Handler)>)
 383                  -> (bool /* suffix illegal? */, Option<ast::LitKind>) {
 384     use ast::LitKind;
 385
 386     match lit {
 387        token::Byte(i) => (true, Some(LitKind::Byte(byte_lit(&i.as_str()).0))),
 388        token::Char(i) => (true, Some(LitKind::Char(char_lit(&i.as_str()).0))),
 389
 390         // There are some valid suffixes for integer and float literals,
 391         // so all the handling is done internally.
 392         token::Integer(s) => (false, integer_lit(&s.as_str(), suf, diag)),
 393         token::Float(s) => (false, float_lit(&s.as_str(), suf, diag)),
 394
 395         token::Str_(s) => {
 396             let s = Symbol::intern(&str_lit(&s.as_str()));
 397             (true, Some(LitKind::Str(s, ast::StrStyle::Cooked)))
 398         }
 399         token::StrRaw(s, n) => {
 400             let s = Symbol::intern(&raw_str_lit(&s.as_str()));
 401             (true, Some(LitKind::Str(s, ast::StrStyle::Raw(n))))
 402         }
 403         token::ByteStr(i) => {
 404             (true, Some(LitKind::ByteStr(byte_str_lit(&i.as_str()))))
 405         }
 406         token::ByteStrRaw(i, _) => {
 407             (true, Some(LitKind::ByteStr(Rc::new(i.to_string().into_bytes()))))
 408         }
 409     }
 410 }
 411
 412 fn filtered_float_lit(data: Symbol, suffix: Option<Symbol>, diag: Option<(Span, &Handler)>)
 413                       -> Option<ast::LitKind> {
 414     debug!("filtered_float_lit: {}, {:?}", data, suffix);
 415     let suffix = match suffix {
 416         Some(suffix) => suffix,
 417         None => return Some(ast::LitKind::FloatUnsuffixed(data)),
 418     };
 419
 420     Some(match &*suffix.as_str() {
 421         "f32" => ast::LitKind::Float(data, ast::FloatTy::F32),
 422         "f64" => ast::LitKind::Float(data, ast::FloatTy::F64),
 423         suf => {
 424             err!(diag, |span, diag| {
 425                 if suf.len() >= 2 && looks_like_width_suffix(&['f'], suf) {
 426                     // if it looks like a width, lets try to be helpful.
 427                     let msg = format!("invalid width `{}` for float literal", &suf[1..]);
 428                     diag.struct_span_err(span, &msg).help("valid widths are 32 and 64").emit()
 429                 } else {
 430                     let msg = format!("invalid suffix `{}` for float literal", suf);
 431                     diag.struct_span_err(span, &msg)
 432                         .help("valid suffixes are `f32` and `f64`")
 433                         .emit();
 434                 }
 435             });
 436
 437             ast::LitKind::FloatUnsuffixed(data)
 438         }
 439     })
 440 }
 441 pub fn float_lit(s: &str, suffix: Option<Symbol>, diag: Option<(Span, &Handler)>)
 442                  -> Option<ast::LitKind> {
 443     debug!("float_lit: {:?}, {:?}", s, suffix);
 444     // FIXME #2252: bounds checking float literals is deferred until trans
 445     let s = s.chars().filter(|&c| c != '_').collect::<String>();
 446     filtered_float_lit(Symbol::intern(&s), suffix, diag)
 447 }
 448
 449 /// Parse a string representing a byte literal into its final form. Similar to `char_lit`
 450 pub fn byte_lit(lit: &str) -> (u8, usize) {
 451     let err = |i| format!("lexer accepted invalid byte literal {} step {}", lit, i);
 452
 453     if lit.len() == 1 {
 454         (lit.as_bytes()[0], 1)
 455     } else {
 456         assert_eq!(lit.as_bytes()[0], b'\\', "{}", err(0));
 457         let b = match lit.as_bytes()[1] {
 458             b'"' => b'"',
 459             b'n' => b'\n',
 460             b'r' => b'\r',
 461             b't' => b'\t',
 462             b'\\' => b'\\',
 463             b'\'' => b'\'',
 464             b'0' => b'\0',
 465             _ => {
 466                 match u64::from_str_radix(&lit[2..4], 16).ok() {
 467                     Some(c) =>
 468                         if c > 0xFF {
 469                             panic!(err(2))
 470                         } else {
 471                             return (c as u8, 4)
 472                         },
 473                     None => panic!(err(3))
 474                 }
 475             }
 476         };
 477         (b, 2)
 478     }
 479 }
 480
 481 pub fn byte_str_lit(lit: &str) -> Rc<Vec<u8>> {
 482     let mut res = Vec::with_capacity(lit.len());
 483
 484     // FIXME #8372: This could be a for-loop if it didn't borrow the iterator
 485     let error = |i| format!("lexer should have rejected {} at {}", lit, i);
 486
 487     /// Eat everything up to a non-whitespace
 488     fn eat<I: Iterator<Item=(usize, u8)>>(it: &mut iter::Peekable<I>) {
 489         loop {
 490             match it.peek().map(|x| x.1) {
 491                 Some(b' ') | Some(b'\n') | Some(b'\r') | Some(b'\t') => {
 492                     it.next();
 493                 },
 494                 _ => { break; }
 495             }
 496         }
 497     }
 498
 499     // byte string literals *must* be ASCII, but the escapes don't have to be
 500     let mut chars = lit.bytes().enumerate().peekable();
 501     loop {
 502         match chars.next() {
 503             Some((i, b'\\')) => {
 504                 let em = error(i);
 505                 match chars.peek().expect(&em).1 {
 506                     b'\n' => eat(&mut chars),
 507                     b'\r' => {
 508                         chars.next();
 509                         if chars.peek().expect(&em).1 != b'\n' {
 510                             panic!("lexer accepted bare CR");
 511                         }
 512                         eat(&mut chars);
 513                     }
 514                     _ => {
 515                         // otherwise, a normal escape
 516                         let (c, n) = byte_lit(&lit[i..]);
 517                         // we don't need to move past the first \
 518                         for _ in 0..n - 1 {
 519                             chars.next();
 520                         }
 521                         res.push(c);
 522                     }
 523                 }
 524             },
 525             Some((i, b'\r')) => {
 526                 let em = error(i);
 527                 if chars.peek().expect(&em).1 != b'\n' {
 528                     panic!("lexer accepted bare CR");
 529                 }
 530                 chars.next();
 531                 res.push(b'\n');
 532             }
 533             Some((_, c)) => res.push(c),
 534             None => break,
 535         }
 536     }
 537
 538     Rc::new(res)
 539 }
 540
 541 pub fn integer_lit(s: &str, suffix: Option<Symbol>, diag: Option<(Span, &Handler)>)
 542                    -> Option<ast::LitKind> {
 543     // s can only be ascii, byte indexing is fine
 544
 545     let s2 = s.chars().filter(|&c| c != '_').collect::<String>();
 546     let mut s = &s2[..];
 547
 548     debug!("integer_lit: {}, {:?}", s, suffix);
 549
 550     let mut base = 10;
 551     let orig = s;
 552     let mut ty = ast::LitIntType::Unsuffixed;
 553
 554     if char_at(s, 0) == '0' && s.len() > 1 {
 555         match char_at(s, 1) {
 556             'x' => base = 16,
 557             'o' => base = 8,
 558             'b' => base = 2,
 559             _ => { }
 560         }
 561     }
 562
 563     // 1f64 and 2f32 etc. are valid float literals.
 564     if let Some(suf) = suffix {
 565         if looks_like_width_suffix(&['f'], &suf.as_str()) {
 566             let err = match base {
 567                 16 => Some("hexadecimal float literal is not supported"),
 568                 8 => Some("octal float literal is not supported"),
 569                 2 => Some("binary float literal is not supported"),
 570                 _ => None,
 571             };
 572             if let Some(err) = err {
 573                 err!(diag, |span, diag| diag.span_err(span, err));
 574             }
 575             return filtered_float_lit(Symbol::intern(s), Some(suf), diag)
 576         }
 577     }
 578
 579     if base != 10 {
 580         s = &s[2..];
 581     }
 582
 583     if let Some(suf) = suffix {
 584         if suf.as_str().is_empty() {
 585             err!(diag, |span, diag| diag.span_bug(span, "found empty literal suffix in Some"));
 586         }
 587         ty = match &*suf.as_str() {
 588             "isize" => ast::LitIntType::Signed(ast::IntTy::Is),
 589             "i8"  => ast::LitIntType::Signed(ast::IntTy::I8),
 590             "i16" => ast::LitIntType::Signed(ast::IntTy::I16),
 591             "i32" => ast::LitIntType::Signed(ast::IntTy::I32),
 592             "i64" => ast::LitIntType::Signed(ast::IntTy::I64),
 593             "i128" => ast::LitIntType::Signed(ast::IntTy::I128),
 594             "usize" => ast::LitIntType::Unsigned(ast::UintTy::Us),
 595             "u8"  => ast::LitIntType::Unsigned(ast::UintTy::U8),
 596             "u16" => ast::LitIntType::Unsigned(ast::UintTy::U16),
 597             "u32" => ast::LitIntType::Unsigned(ast::UintTy::U32),
 598             "u64" => ast::LitIntType::Unsigned(ast::UintTy::U64),
 599             "u128" => ast::LitIntType::Unsigned(ast::UintTy::U128),
 600             suf => {
 601                 // i<digits> and u<digits> look like widths, so lets
 602                 // give an error message along those lines
 603                 err!(diag, |span, diag| {
 604                     if looks_like_width_suffix(&['i', 'u'], suf) {
 605                         let msg = format!("invalid width `{}` for integer literal", &suf[1..]);
 606                         diag.struct_span_err(span, &msg)
 607                             .help("valid widths are 8, 16, 32, 64 and 128")
 608                             .emit();
 609                     } else {
 610                         let msg = format!("invalid suffix `{}` for numeric literal", suf);
 611                         diag.struct_span_err(span, &msg)
 612                             .help("the suffix must be one of the integral types \
 613                                    (`u32`, `isize`, etc)")
 614                             .emit();
 615                     }
 616                 });
 617
 618                 ty
 619             }
 620         }
 621     }
 622
 623     debug!("integer_lit: the type is {:?}, base {:?}, the new string is {:?}, the original \
 624            string was {:?}, the original suffix was {:?}", ty, base, s, orig, suffix);
 625
 626     Some(match u128::from_str_radix(s, base) {
 627         Ok(r) => ast::LitKind::Int(r, ty),
 628         Err(_) => {
 629             // small bases are lexed as if they were base 10, e.g, the string
 630             // might be `0b10201`. This will cause the conversion above to fail,
 631             // but these cases have errors in the lexer: we don't want to emit
 632             // two errors, and we especially don't want to emit this error since
 633             // it isn't necessarily true.
 634             let already_errored = base < 10 &&
 635                 s.chars().any(|c| c.to_digit(10).map_or(false, |d| d >= base));
 636
 637             if !already_errored {
 638                 err!(diag, |span, diag| diag.span_err(span, "int literal is too large"));
 639             }
 640             ast::LitKind::Int(0, ty)
 641         }
 642     })
 643 }
 644
 645 #[cfg(test)]
 646 mod tests {
 647     use super::*;
 648     use syntax_pos::{self, Span, BytePos, Pos, NO_EXPANSION};
 649     use codemap::Spanned;
 650     use ast::{self, Ident, PatKind};
 651     use abi::Abi;
 652     use attr::first_attr_value_str_by_name;
 653     use parse;
 654     use parse::parser::Parser;
 655     use print::pprust::item_to_string;
 656     use ptr::P;
 657     use tokenstream::{self, TokenTree};
 658     use util::parser_testing::{string_to_stream, string_to_parser};
 659     use util::parser_testing::{string_to_expr, string_to_item, string_to_stmt};
 660     use util::ThinVec;
 661
 662     // produce a syntax_pos::span
 663     fn sp(a: u32, b: u32) -> Span {
 664         Span {lo: BytePos(a), hi: BytePos(b), ctxt: NO_EXPANSION}
 665     }
 666
 667     fn str2seg(s: &str, lo: u32, hi: u32) -> ast::PathSegment {
 668         ast::PathSegment::from_ident(Ident::from_str(s), sp(lo, hi))
 669     }
 670
 671     #[test] fn path_exprs_1() {
 672         assert!(string_to_expr("a".to_string()) ==
 673                    P(ast::Expr{
 674                     id: ast::DUMMY_NODE_ID,
 675                     node: ast::ExprKind::Path(None, ast::Path {
 676                         span: sp(0, 1),
 677                         segments: vec![str2seg("a", 0, 1)],
 678                     }),
 679                     span: sp(0, 1),
 680                     attrs: ThinVec::new(),
 681                    }))
 682     }
 683
 684     #[test] fn path_exprs_2 () {
 685         assert!(string_to_expr("::a::b".to_string()) ==
 686                    P(ast::Expr {
 687                     id: ast::DUMMY_NODE_ID,
 688                     node: ast::ExprKind::Path(None, ast::Path {
 689                         span: sp(0, 6),
 690                         segments: vec![ast::PathSegment::crate_root(sp(0, 2)),
 691                                        str2seg("a", 2, 3),
 692                                        str2seg("b", 5, 6)]
 693                     }),
 694                     span: sp(0, 6),
 695                     attrs: ThinVec::new(),
 696                    }))
 697     }
 698
 699     #[should_panic]
 700     #[test] fn bad_path_expr_1() {
 701         string_to_expr("::abc::def::return".to_string());
 702     }
 703
 704     // check the token-tree-ization of macros
 705     #[test]
 706     fn string_to_tts_macro () {
 707         let tts: Vec<_> =
 708             string_to_stream("macro_rules! zip (($a)=>($a))".to_string()).trees().collect();
 709         let tts: &[TokenTree] = &tts[..];
 710
 711         match (tts.len(), tts.get(0), tts.get(1), tts.get(2), tts.get(3)) {
 712             (
 713                 4,
 714                 Some(&TokenTree::Token(_, token::Ident(name_macro_rules))),
 715                 Some(&TokenTree::Token(_, token::Not)),
 716                 Some(&TokenTree::Token(_, token::Ident(name_zip))),
 717                 Some(&TokenTree::Delimited(_, ref macro_delimed)),
 718             )
 719             if name_macro_rules.name == "macro_rules"
 720             && name_zip.name == "zip" => {
 721                 let tts = &macro_delimed.stream().trees().collect::<Vec<_>>();
 722                 match (tts.len(), tts.get(0), tts.get(1), tts.get(2)) {
 723                     (
 724                         3,
 725                         Some(&TokenTree::Delimited(_, ref first_delimed)),
 726                         Some(&TokenTree::Token(_, token::FatArrow)),
 727                         Some(&TokenTree::Delimited(_, ref second_delimed)),
 728                     )
 729                     if macro_delimed.delim == token::Paren => {
 730                         let tts = &first_delimed.stream().trees().collect::<Vec<_>>();
 731                         match (tts.len(), tts.get(0), tts.get(1)) {
 732                             (
 733                                 2,
 734                                 Some(&TokenTree::Token(_, token::Dollar)),
 735                                 Some(&TokenTree::Token(_, token::Ident(ident))),
 736                             )
 737                             if first_delimed.delim == token::Paren && ident.name == "a" => {},
 738                             _ => panic!("value 3: {:?}", *first_delimed),
 739                         }
 740                         let tts = &second_delimed.stream().trees().collect::<Vec<_>>();
 741                         match (tts.len(), tts.get(0), tts.get(1)) {
 742                             (
 743                                 2,
 744                                 Some(&TokenTree::Token(_, token::Dollar)),
 745                                 Some(&TokenTree::Token(_, token::Ident(ident))),
 746                             )
 747                             if second_delimed.delim == token::Paren
 748                             && ident.name == "a" => {},
 749                             _ => panic!("value 4: {:?}", *second_delimed),
 750                         }
 751                     },
 752                     _ => panic!("value 2: {:?}", *macro_delimed),
 753                 }
 754             },
 755             _ => panic!("value: {:?}",tts),
 756         }
 757     }
 758
 759     #[test]
 760     fn string_to_tts_1() {
 761         let tts = string_to_stream("fn a (b : i32) { b; }".to_string());
 762
 763         let expected = TokenStream::concat(vec![
 764             TokenTree::Token(sp(0, 2), token::Ident(Ident::from_str("fn"))).into(),
 765             TokenTree::Token(sp(3, 4), token::Ident(Ident::from_str("a"))).into(),
 766             TokenTree::Delimited(
 767                 sp(5, 14),
 768                 tokenstream::Delimited {
 769                     delim: token::DelimToken::Paren,
 770                     tts: TokenStream::concat(vec![
 771                         TokenTree::Token(sp(6, 7), token::Ident(Ident::from_str("b"))).into(),
 772                         TokenTree::Token(sp(8, 9), token::Colon).into(),
 773                         TokenTree::Token(sp(10, 13), token::Ident(Ident::from_str("i32"))).into(),
 774                     ]).into(),
 775                 }).into(),
 776             TokenTree::Delimited(
 777                 sp(15, 21),
 778                 tokenstream::Delimited {
 779                     delim: token::DelimToken::Brace,
 780                     tts: TokenStream::concat(vec![
 781                         TokenTree::Token(sp(17, 18), token::Ident(Ident::from_str("b"))).into(),
 782                         TokenTree::Token(sp(18, 19), token::Semi).into(),
 783                     ]).into(),
 784                 }).into()
 785         ]);
 786
 787         assert_eq!(tts, expected);
 788     }
 789
 790     #[test] fn ret_expr() {
 791         assert!(string_to_expr("return d".to_string()) ==
 792                    P(ast::Expr{
 793                     id: ast::DUMMY_NODE_ID,
 794                     node:ast::ExprKind::Ret(Some(P(ast::Expr{
 795                         id: ast::DUMMY_NODE_ID,
 796                         node:ast::ExprKind::Path(None, ast::Path{
 797                             span: sp(7, 8),
 798                             segments: vec![str2seg("d", 7, 8)],
 799                         }),
 800                         span:sp(7,8),
 801                         attrs: ThinVec::new(),
 802                     }))),
 803                     span:sp(0,8),
 804                     attrs: ThinVec::new(),
 805                    }))
 806     }
 807
 808     #[test] fn parse_stmt_1 () {
 809         assert!(string_to_stmt("b;".to_string()) ==
 810                    Some(ast::Stmt {
 811                        node: ast::StmtKind::Expr(P(ast::Expr {
 812                            id: ast::DUMMY_NODE_ID,
 813                            node: ast::ExprKind::Path(None, ast::Path {
 814                                span:sp(0,1),
 815                                segments: vec![str2seg("b", 0, 1)],
 816                             }),
 817                            span: sp(0,1),
 818                            attrs: ThinVec::new()})),
 819                        id: ast::DUMMY_NODE_ID,
 820                        span: sp(0,1)}))
 821
 822     }
 823
 824     fn parser_done(p: Parser){
 825         assert_eq!(p.token.clone(), token::Eof);
 826     }
 827
 828     #[test] fn parse_ident_pat () {
 829         let sess = ParseSess::new(FilePathMapping::empty());
 830         let mut parser = string_to_parser(&sess, "b".to_string());
 831         assert!(panictry!(parser.parse_pat())
 832                 == P(ast::Pat{
 833                 id: ast::DUMMY_NODE_ID,
 834                 node: PatKind::Ident(ast::BindingMode::ByValue(ast::Mutability::Immutable),
 835                                     Spanned{ span:sp(0, 1),
 836                                              node: Ident::from_str("b")
 837                     },
 838                                     None),
 839                 span: sp(0,1)}));
 840         parser_done(parser);
 841     }
 842
 843     // check the contents of the tt manually:
 844     #[test] fn parse_fundecl () {
 845         // this test depends on the intern order of "fn" and "i32"
 846         assert_eq!(string_to_item("fn a (b : i32) { b; }".to_string()),
 847                   Some(
 848                       P(ast::Item{ident:Ident::from_str("a"),
 849                             attrs:Vec::new(),
 850                             id: ast::DUMMY_NODE_ID,
 851                             node: ast::ItemKind::Fn(P(ast::FnDecl {
 852                                 inputs: vec![ast::Arg{
 853                                     ty: P(ast::Ty{id: ast::DUMMY_NODE_ID,
 854                                                   node: ast::TyKind::Path(None, ast::Path{
 855                                         span:sp(10,13),
 856                                         segments: vec![str2seg("i32", 10, 13)],
 857                                         }),
 858                                         span:sp(10,13)
 859                                     }),
 860                                     pat: P(ast::Pat {
 861                                         id: ast::DUMMY_NODE_ID,
 862                                         node: PatKind::Ident(
 863                                             ast::BindingMode::ByValue(ast::Mutability::Immutable),
 864                                                 Spanned{
 865                                                     span: sp(6,7),
 866                                                     node: Ident::from_str("b")},
 867                                                 None
 868                                                     ),
 869                                             span: sp(6,7)
 870                                     }),
 871                                         id: ast::DUMMY_NODE_ID
 872                                     }],
 873                                 output: ast::FunctionRetTy::Default(sp(15, 15)),
 874                                 variadic: false
 875                             }),
 876                                     ast::Unsafety::Normal,
 877                                     Spanned {
 878                                         span: sp(0,2),
 879                                         node: ast::Constness::NotConst,
 880                                     },
 881                                     Abi::Rust,
 882                                     ast::Generics{ // no idea on either of these:
 883                                         lifetimes: Vec::new(),
 884                                         ty_params: Vec::new(),
 885                                         where_clause: ast::WhereClause {
 886                                             id: ast::DUMMY_NODE_ID,
 887                                             predicates: Vec::new(),
 888                                         },
 889                                         span: syntax_pos::DUMMY_SP,
 890                                     },
 891                                     P(ast::Block {
 892                                         stmts: vec![ast::Stmt {
 893                                             node: ast::StmtKind::Semi(P(ast::Expr{
 894                                                 id: ast::DUMMY_NODE_ID,
 895                                                 node: ast::ExprKind::Path(None,
 896                                                       ast::Path{
 897                                                         span:sp(17,18),
 898                                                         segments: vec![str2seg("b", 17, 18)],
 899                                                       }),
 900                                                 span: sp(17,18),
 901                                                 attrs: ThinVec::new()})),
 902                                             id: ast::DUMMY_NODE_ID,
 903                                             span: sp(17,19)}],
 904                                         id: ast::DUMMY_NODE_ID,
 905                                         rules: ast::BlockCheckMode::Default, // no idea
 906                                         span: sp(15,21),
 907                                     })),
 908                             vis: ast::Visibility::Inherited,
 909                             span: sp(0,21)})));
 910     }
 911
 912     #[test] fn parse_use() {
 913         let use_s = "use foo::bar::baz;";
 914         let vitem = string_to_item(use_s.to_string()).unwrap();
 915         let vitem_s = item_to_string(&vitem);
 916         assert_eq!(&vitem_s[..], use_s);
 917
 918         let use_s = "use foo::bar as baz;";
 919         let vitem = string_to_item(use_s.to_string()).unwrap();
 920         let vitem_s = item_to_string(&vitem);
 921         assert_eq!(&vitem_s[..], use_s);
 922     }
 923
 924     #[test] fn parse_extern_crate() {
 925         let ex_s = "extern crate foo;";
 926         let vitem = string_to_item(ex_s.to_string()).unwrap();
 927         let vitem_s = item_to_string(&vitem);
 928         assert_eq!(&vitem_s[..], ex_s);
 929
 930         let ex_s = "extern crate foo as bar;";
 931         let vitem = string_to_item(ex_s.to_string()).unwrap();
 932         let vitem_s = item_to_string(&vitem);
 933         assert_eq!(&vitem_s[..], ex_s);
 934     }
 935
 936     fn get_spans_of_pat_idents(src: &str) -> Vec<Span> {
 937         let item = string_to_item(src.to_string()).unwrap();
 938
 939         struct PatIdentVisitor {
 940             spans: Vec<Span>
 941         }
 942         impl<'a> ::visit::Visitor<'a> for PatIdentVisitor {
 943             fn visit_pat(&mut self, p: &'a ast::Pat) {
 944                 match p.node {
 945                     PatKind::Ident(_ , ref spannedident, _) => {
 946                         self.spans.push(spannedident.span.clone());
 947                     }
 948                     _ => {
 949                         ::visit::walk_pat(self, p);
 950                     }
 951                 }
 952             }
 953         }
 954         let mut v = PatIdentVisitor { spans: Vec::new() };
 955         ::visit::walk_item(&mut v, &item);
 956         return v.spans;
 957     }
 958
 959     #[test] fn span_of_self_arg_pat_idents_are_correct() {
 960
 961         let srcs = ["impl z { fn a (&self, &myarg: i32) {} }",
 962                     "impl z { fn a (&mut self, &myarg: i32) {} }",
 963                     "impl z { fn a (&'a self, &myarg: i32) {} }",
 964                     "impl z { fn a (self, &myarg: i32) {} }",
 965                     "impl z { fn a (self: Foo, &myarg: i32) {} }",
 966                     ];
 967
 968         for &src in &srcs {
 969             let spans = get_spans_of_pat_idents(src);
 970             let Span{ lo, hi, .. } = spans[0];
 971             assert!("self" == &src[lo.to_usize()..hi.to_usize()],
 972                     "\"{}\" != \"self\". src=\"{}\"",
 973                     &src[lo.to_usize()..hi.to_usize()], src)
 974         }
 975     }
 976
 977     #[test] fn parse_exprs () {
 978         // just make sure that they parse....
 979         string_to_expr("3 + 4".to_string());
 980         string_to_expr("a::z.froob(b,&(987+3))".to_string());
 981     }
 982
 983     #[test] fn attrs_fix_bug () {
 984         string_to_item("pub fn mk_file_writer(path: &Path, flags: &[FileFlag])
 985                    -> Result<Box<Writer>, String> {
 986     #[cfg(windows)]
 987     fn wb() -> c_int {
 988       (O_WRONLY | libc::consts::os::extra::O_BINARY) as c_int
 989     }
 990
 991     #[cfg(unix)]
 992     fn wb() -> c_int { O_WRONLY as c_int }
 993
 994     let mut fflags: c_int = wb();
 995 }".to_string());
 996     }
 997
 998     #[test] fn crlf_doc_comments() {
 999         let sess = ParseSess::new(FilePathMapping::empty());
1000
1001         let name = "<source>".to_string();
1002         let source = "/// doc comment\r\nfn foo() {}".to_string();
1003         let item = parse_item_from_source_str(name.clone(), source, &sess)
1004             .unwrap().unwrap();
1005         let doc = first_attr_value_str_by_name(&item.attrs, "doc").unwrap();
1006         assert_eq!(doc, "/// doc comment");
1007
1008         let source = "/// doc comment\r\n/// line 2\r\nfn foo() {}".to_string();
1009         let item = parse_item_from_source_str(name.clone(), source, &sess)
1010             .unwrap().unwrap();
1011         let docs = item.attrs.iter().filter(|a| a.path == "doc")
1012                     .map(|a| a.value_str().unwrap().to_string()).collect::<Vec<_>>();
1013         let b: &[_] = &["/// doc comment".to_string(), "/// line 2".to_string()];
1014         assert_eq!(&docs[..], b);
1015
1016         let source = "/** doc comment\r\n *  with CRLF */\r\nfn foo() {}".to_string();
1017         let item = parse_item_from_source_str(name, source, &sess).unwrap().unwrap();
1018         let doc = first_attr_value_str_by_name(&item.attrs, "doc").unwrap();
1019         assert_eq!(doc, "/** doc comment\n *  with CRLF */");
1020     }
1021
1022     #[test]
1023     fn ttdelim_span() {
1024         let sess = ParseSess::new(FilePathMapping::empty());
1025         let expr = parse::parse_expr_from_source_str("foo".to_string(),
1026             "foo!( fn main() { body } )".to_string(), &sess).unwrap();
1027
1028         let tts: Vec<_> = match expr.node {
1029             ast::ExprKind::Mac(ref mac) => mac.node.stream().trees().collect(),
1030             _ => panic!("not a macro"),
1031         };
1032
1033         let span = tts.iter().rev().next().unwrap().span();
1034
1035         match sess.codemap().span_to_snippet(span) {
1036             Ok(s) => assert_eq!(&s[..], "{ body }"),
1037             Err(_) => panic!("could not get snippet"),
1038         }
1039     }
1040
1041     // This tests that when parsing a string (rather than a file) we don't try
1042     // and read in a file for a module declaration and just parse a stub.
1043     // See `recurse_into_file_modules` in the parser.
1044     #[test]
1045     fn out_of_line_mod() {
1046         let sess = ParseSess::new(FilePathMapping::empty());
1047         let item = parse_item_from_source_str(
1048             "foo".to_owned(),
1049             "mod foo { struct S; mod this_does_not_exist; }".to_owned(),
1050             &sess,
1051         ).unwrap().unwrap();
1052
1053         if let ast::ItemKind::Mod(ref m) = item.node {
1054             assert!(m.items.len() == 2);
1055         } else {
1056             panic!();
1057         }
1058     }
1059 }