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, FileName};
  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     // Spans where a `mod foo;` statement was included in a non-mod.rs file.
  51     // These are used to issue errors if the non_modrs_mods feature is not enabled.
  52     pub non_modrs_mods: RefCell<Vec<(ast::Ident, Span)>>,
  53     /// Used to determine and report recursive mod inclusions
  54     included_mod_stack: RefCell<Vec<PathBuf>>,
  55     code_map: Rc<CodeMap>,
  56 }
  57
  58 impl ParseSess {
  59     pub fn new(file_path_mapping: FilePathMapping) -> Self {
  60         let cm = Rc::new(CodeMap::new(file_path_mapping));
  61         let handler = Handler::with_tty_emitter(ColorConfig::Auto,
  62                                                 true,
  63                                                 false,
  64                                                 Some(cm.clone()));
  65         ParseSess::with_span_handler(handler, cm)
  66     }
  67
  68     pub fn with_span_handler(handler: Handler, code_map: Rc<CodeMap>) -> ParseSess {
  69         ParseSess {
  70             span_diagnostic: handler,
  71             unstable_features: UnstableFeatures::from_environment(),
  72             config: HashSet::new(),
  73             missing_fragment_specifiers: RefCell::new(HashSet::new()),
  74             included_mod_stack: RefCell::new(vec![]),
  75             code_map,
  76             non_modrs_mods: RefCell::new(vec![]),
  77         }
  78     }
  79
  80     pub fn codemap(&self) -> &CodeMap {
  81         &self.code_map
  82     }
  83 }
  84
  85 #[derive(Clone)]
  86 pub struct Directory {
  87     pub path: PathBuf,
  88     pub ownership: DirectoryOwnership,
  89 }
  90
  91 #[derive(Copy, Clone)]
  92 pub enum DirectoryOwnership {
  93     Owned {
  94         // None if `mod.rs`, `Some("foo")` if we're in `foo.rs`
  95         relative: Option<ast::Ident>,
  96     },
  97     UnownedViaBlock,
  98     UnownedViaMod(bool /* legacy warnings? */),
  99 }
 100
 101 // a bunch of utility functions of the form parse_<thing>_from_<source>
 102 // where <thing> includes crate, expr, item, stmt, tts, and one that
 103 // uses a HOF to parse anything, and <source> includes file and
 104 // source_str.
 105
 106 pub fn parse_crate_from_file<'a>(input: &Path, sess: &'a ParseSess) -> PResult<'a, ast::Crate> {
 107     let mut parser = new_parser_from_file(sess, input);
 108     parser.parse_crate_mod()
 109 }
 110
 111 pub fn parse_crate_attrs_from_file<'a>(input: &Path, sess: &'a ParseSess)
 112                                        -> PResult<'a, Vec<ast::Attribute>> {
 113     let mut parser = new_parser_from_file(sess, input);
 114     parser.parse_inner_attributes()
 115 }
 116
 117 pub fn parse_crate_from_source_str(name: FileName, source: String, sess: &ParseSess)
 118                                        -> PResult<ast::Crate> {
 119     new_parser_from_source_str(sess, name, source).parse_crate_mod()
 120 }
 121
 122 pub fn parse_crate_attrs_from_source_str(name: FileName, source: String, sess: &ParseSess)
 123                                              -> PResult<Vec<ast::Attribute>> {
 124     new_parser_from_source_str(sess, name, source).parse_inner_attributes()
 125 }
 126
 127 pub fn parse_expr_from_source_str(name: FileName, source: String, sess: &ParseSess)
 128                                       -> PResult<P<ast::Expr>> {
 129     new_parser_from_source_str(sess, name, source).parse_expr()
 130 }
 131
 132 /// Parses an item.
 133 ///
 134 /// Returns `Ok(Some(item))` when successful, `Ok(None)` when no item was found, and `Err`
 135 /// when a syntax error occurred.
 136 pub fn parse_item_from_source_str(name: FileName, source: String, sess: &ParseSess)
 137                                       -> PResult<Option<P<ast::Item>>> {
 138     new_parser_from_source_str(sess, name, source).parse_item()
 139 }
 140
 141 pub fn parse_meta_from_source_str(name: FileName, source: String, sess: &ParseSess)
 142                                       -> PResult<ast::MetaItem> {
 143     new_parser_from_source_str(sess, name, source).parse_meta_item()
 144 }
 145
 146 pub fn parse_stmt_from_source_str(name: FileName, source: String, sess: &ParseSess)
 147                                       -> PResult<Option<ast::Stmt>> {
 148     new_parser_from_source_str(sess, name, source).parse_stmt()
 149 }
 150
 151 pub fn parse_stream_from_source_str(name: FileName, source: String, sess: &ParseSess,
 152                                     override_span: Option<Span>)
 153                                     -> TokenStream {
 154     filemap_to_stream(sess, sess.codemap().new_filemap(name, source), override_span)
 155 }
 156
 157 // Create a new parser from a source string
 158 pub fn new_parser_from_source_str(sess: &ParseSess, name: FileName, source: String)
 159                                       -> Parser {
 160     let mut parser = filemap_to_parser(sess, sess.codemap().new_filemap(name, source));
 161     parser.recurse_into_file_modules = false;
 162     parser
 163 }
 164
 165 /// Create a new parser, handling errors as appropriate
 166 /// if the file doesn't exist
 167 pub fn new_parser_from_file<'a>(sess: &'a ParseSess, path: &Path) -> Parser<'a> {
 168     filemap_to_parser(sess, file_to_filemap(sess, path, None))
 169 }
 170
 171 /// Given a session, a crate config, a path, and a span, add
 172 /// the file at the given path to the codemap, and return a parser.
 173 /// On an error, use the given span as the source of the problem.
 174 pub fn new_sub_parser_from_file<'a>(sess: &'a ParseSess,
 175                                     path: &Path,
 176                                     directory_ownership: DirectoryOwnership,
 177                                     module_name: Option<String>,
 178                                     sp: Span) -> Parser<'a> {
 179     let mut p = filemap_to_parser(sess, file_to_filemap(sess, path, Some(sp)));
 180     p.directory.ownership = directory_ownership;
 181     p.root_module_name = module_name;
 182     p
 183 }
 184
 185 /// Given a filemap and config, return a parser
 186 pub fn filemap_to_parser(sess: & ParseSess, filemap: Rc<FileMap>, ) -> Parser {
 187     let end_pos = filemap.end_pos;
 188     let mut parser = stream_to_parser(sess, filemap_to_stream(sess, filemap, None));
 189
 190     if parser.token == token::Eof && parser.span == syntax_pos::DUMMY_SP {
 191         parser.span = Span::new(end_pos, end_pos, NO_EXPANSION);
 192     }
 193
 194     parser
 195 }
 196
 197 // must preserve old name for now, because quote! from the *existing*
 198 // compiler expands into it
 199 pub fn new_parser_from_tts(sess: &ParseSess, tts: Vec<TokenTree>) -> Parser {
 200     stream_to_parser(sess, tts.into_iter().collect())
 201 }
 202
 203
 204 // base abstractions
 205
 206 /// Given a session and a path and an optional span (for error reporting),
 207 /// add the path to the session's codemap and return the new filemap.
 208 fn file_to_filemap(sess: &ParseSess, path: &Path, spanopt: Option<Span>)
 209                    -> Rc<FileMap> {
 210     match sess.codemap().load_file(path) {
 211         Ok(filemap) => filemap,
 212         Err(e) => {
 213             let msg = format!("couldn't read {:?}: {}", path.display(), e);
 214             match spanopt {
 215                 Some(sp) => panic!(sess.span_diagnostic.span_fatal(sp, &msg)),
 216                 None => panic!(sess.span_diagnostic.fatal(&msg))
 217             }
 218         }
 219     }
 220 }
 221
 222 /// Given a filemap, produce a sequence of token-trees
 223 pub fn filemap_to_stream(sess: &ParseSess, filemap: Rc<FileMap>, override_span: Option<Span>)
 224                          -> TokenStream {
 225     let mut srdr = lexer::StringReader::new(sess, filemap);
 226     srdr.override_span = override_span;
 227     srdr.real_token();
 228     panictry!(srdr.parse_all_token_trees())
 229 }
 230
 231 /// Given stream and the `ParseSess`, produce a parser
 232 pub fn stream_to_parser(sess: &ParseSess, stream: TokenStream) -> Parser {
 233     Parser::new(sess, stream, None, true, false)
 234 }
 235
 236 /// Parse a string representing a character literal into its final form.
 237 /// Rather than just accepting/rejecting a given literal, unescapes it as
 238 /// well. Can take any slice prefixed by a character escape. Returns the
 239 /// character and the number of characters consumed.
 240 pub fn char_lit(lit: &str, diag: Option<(Span, &Handler)>) -> (char, isize) {
 241     use std::char;
 242
 243     // Handle non-escaped chars first.
 244     if lit.as_bytes()[0] != b'\\' {
 245         // If the first byte isn't '\\' it might part of a multi-byte char, so
 246         // get the char with chars().
 247         let c = lit.chars().next().unwrap();
 248         return (c, 1);
 249     }
 250
 251     // Handle escaped chars.
 252     match lit.as_bytes()[1] as char {
 253         '"' => ('"', 2),
 254         'n' => ('\n', 2),
 255         'r' => ('\r', 2),
 256         't' => ('\t', 2),
 257         '\\' => ('\\', 2),
 258         '\'' => ('\'', 2),
 259         '0' => ('\0', 2),
 260         'x' => {
 261             let v = u32::from_str_radix(&lit[2..4], 16).unwrap();
 262             let c = char::from_u32(v).unwrap();
 263             (c, 4)
 264         }
 265         'u' => {
 266             assert_eq!(lit.as_bytes()[2], b'{');
 267             let idx = lit.find('}').unwrap();
 268             let s = &lit[3..idx].chars().filter(|&c| c != '_').collect::<String>();
 269             let v = u32::from_str_radix(&s, 16).unwrap();
 270             let c = char::from_u32(v).unwrap_or_else(|| {
 271                 if let Some((span, diag)) = diag {
 272                     let mut diag = diag.struct_span_err(span, "invalid unicode character escape");
 273                     if v > 0x10FFFF {
 274                         diag.help("unicode escape must be at most 10FFFF").emit();
 275                     } else {
 276                         diag.help("unicode escape must not be a surrogate").emit();
 277                     }
 278                 }
 279                 '\u{FFFD}'
 280             });
 281             (c, (idx + 1) as isize)
 282         }
 283         _ => panic!("lexer should have rejected a bad character escape {}", lit)
 284     }
 285 }
 286
 287 pub fn escape_default(s: &str) -> String {
 288     s.chars().map(char::escape_default).flat_map(|x| x).collect()
 289 }
 290
 291 /// Parse a string representing a string literal into its final form. Does
 292 /// unescaping.
 293 pub fn str_lit(lit: &str, diag: Option<(Span, &Handler)>) -> String {
 294     debug!("parse_str_lit: given {}", escape_default(lit));
 295     let mut res = String::with_capacity(lit.len());
 296
 297     // FIXME #8372: This could be a for-loop if it didn't borrow the iterator
 298     let error = |i| format!("lexer should have rejected {} at {}", lit, i);
 299
 300     /// Eat everything up to a non-whitespace
 301     fn eat<'a>(it: &mut iter::Peekable<str::CharIndices<'a>>) {
 302         loop {
 303             match it.peek().map(|x| x.1) {
 304                 Some(' ') | Some('\n') | Some('\r') | Some('\t') => {
 305                     it.next();
 306                 },
 307                 _ => { break; }
 308             }
 309         }
 310     }
 311
 312     let mut chars = lit.char_indices().peekable();
 313     while let Some((i, c)) = chars.next() {
 314         match c {
 315             '\\' => {
 316                 let ch = chars.peek().unwrap_or_else(|| {
 317                     panic!("{}", error(i))
 318                 }).1;
 319
 320                 if ch == '\n' {
 321                     eat(&mut chars);
 322                 } else if ch == '\r' {
 323                     chars.next();
 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                     eat(&mut chars);
 332                 } else {
 333                     // otherwise, a normal escape
 334                     let (c, n) = char_lit(&lit[i..], diag);
 335                     for _ in 0..n - 1 { // we don't need to move past the first \
 336                         chars.next();
 337                     }
 338                     res.push(c);
 339                 }
 340             },
 341             '\r' => {
 342                 let ch = chars.peek().unwrap_or_else(|| {
 343                     panic!("{}", error(i))
 344                 }).1;
 345
 346                 if ch != '\n' {
 347                     panic!("lexer accepted bare CR");
 348                 }
 349                 chars.next();
 350                 res.push('\n');
 351             }
 352             c => res.push(c),
 353         }
 354     }
 355
 356     res.shrink_to_fit(); // probably not going to do anything, unless there was an escape.
 357     debug!("parse_str_lit: returning {}", res);
 358     res
 359 }
 360
 361 /// Parse a string representing a raw string literal into its final form. The
 362 /// only operation this does is convert embedded CRLF into a single LF.
 363 pub fn raw_str_lit(lit: &str) -> String {
 364     debug!("raw_str_lit: given {}", escape_default(lit));
 365     let mut res = String::with_capacity(lit.len());
 366
 367     let mut chars = lit.chars().peekable();
 368     while let Some(c) = chars.next() {
 369         if c == '\r' {
 370             if *chars.peek().unwrap() != '\n' {
 371                 panic!("lexer accepted bare CR");
 372             }
 373             chars.next();
 374             res.push('\n');
 375         } else {
 376             res.push(c);
 377         }
 378     }
 379
 380     res.shrink_to_fit();
 381     res
 382 }
 383
 384 // check if `s` looks like i32 or u1234 etc.
 385 fn looks_like_width_suffix(first_chars: &[char], s: &str) -> bool {
 386     s.len() > 1 &&
 387         first_chars.contains(&char_at(s, 0)) &&
 388         s[1..].chars().all(|c| '0' <= c && c <= '9')
 389 }
 390
 391 macro_rules! err {
 392     ($opt_diag:expr, |$span:ident, $diag:ident| $($body:tt)*) => {
 393         match $opt_diag {
 394             Some(($span, $diag)) => { $($body)* }
 395             None => return None,
 396         }
 397     }
 398 }
 399
 400 pub fn lit_token(lit: token::Lit, suf: Option<Symbol>, diag: Option<(Span, &Handler)>)
 401                  -> (bool /* suffix illegal? */, Option<ast::LitKind>) {
 402     use ast::LitKind;
 403
 404     match lit {
 405        token::Byte(i) => (true, Some(LitKind::Byte(byte_lit(&i.as_str()).0))),
 406        token::Char(i) => (true, Some(LitKind::Char(char_lit(&i.as_str(), diag).0))),
 407
 408         // There are some valid suffixes for integer and float literals,
 409         // so all the handling is done internally.
 410         token::Integer(s) => (false, integer_lit(&s.as_str(), suf, diag)),
 411         token::Float(s) => (false, float_lit(&s.as_str(), suf, diag)),
 412
 413         token::Str_(s) => {
 414             let s = Symbol::intern(&str_lit(&s.as_str(), diag));
 415             (true, Some(LitKind::Str(s, ast::StrStyle::Cooked)))
 416         }
 417         token::StrRaw(s, n) => {
 418             let s = Symbol::intern(&raw_str_lit(&s.as_str()));
 419             (true, Some(LitKind::Str(s, ast::StrStyle::Raw(n))))
 420         }
 421         token::ByteStr(i) => {
 422             (true, Some(LitKind::ByteStr(byte_str_lit(&i.as_str()))))
 423         }
 424         token::ByteStrRaw(i, _) => {
 425             (true, Some(LitKind::ByteStr(Rc::new(i.to_string().into_bytes()))))
 426         }
 427     }
 428 }
 429
 430 fn filtered_float_lit(data: Symbol, suffix: Option<Symbol>, diag: Option<(Span, &Handler)>)
 431                       -> Option<ast::LitKind> {
 432     debug!("filtered_float_lit: {}, {:?}", data, suffix);
 433     let suffix = match suffix {
 434         Some(suffix) => suffix,
 435         None => return Some(ast::LitKind::FloatUnsuffixed(data)),
 436     };
 437
 438     Some(match &*suffix.as_str() {
 439         "f32" => ast::LitKind::Float(data, ast::FloatTy::F32),
 440         "f64" => ast::LitKind::Float(data, ast::FloatTy::F64),
 441         suf => {
 442             err!(diag, |span, diag| {
 443                 if suf.len() >= 2 && looks_like_width_suffix(&['f'], suf) {
 444                     // if it looks like a width, lets try to be helpful.
 445                     let msg = format!("invalid width `{}` for float literal", &suf[1..]);
 446                     diag.struct_span_err(span, &msg).help("valid widths are 32 and 64").emit()
 447                 } else {
 448                     let msg = format!("invalid suffix `{}` for float literal", suf);
 449                     diag.struct_span_err(span, &msg)
 450                         .help("valid suffixes are `f32` and `f64`")
 451                         .emit();
 452                 }
 453             });
 454
 455             ast::LitKind::FloatUnsuffixed(data)
 456         }
 457     })
 458 }
 459 pub fn float_lit(s: &str, suffix: Option<Symbol>, diag: Option<(Span, &Handler)>)
 460                  -> Option<ast::LitKind> {
 461     debug!("float_lit: {:?}, {:?}", s, suffix);
 462     // FIXME #2252: bounds checking float literals is deferred until trans
 463     let s = s.chars().filter(|&c| c != '_').collect::<String>();
 464     filtered_float_lit(Symbol::intern(&s), suffix, diag)
 465 }
 466
 467 /// Parse a string representing a byte literal into its final form. Similar to `char_lit`
 468 pub fn byte_lit(lit: &str) -> (u8, usize) {
 469     let err = |i| format!("lexer accepted invalid byte literal {} step {}", lit, i);
 470
 471     if lit.len() == 1 {
 472         (lit.as_bytes()[0], 1)
 473     } else {
 474         assert_eq!(lit.as_bytes()[0], b'\\', "{}", err(0));
 475         let b = match lit.as_bytes()[1] {
 476             b'"' => b'"',
 477             b'n' => b'\n',
 478             b'r' => b'\r',
 479             b't' => b'\t',
 480             b'\\' => b'\\',
 481             b'\'' => b'\'',
 482             b'0' => b'\0',
 483             _ => {
 484                 match u64::from_str_radix(&lit[2..4], 16).ok() {
 485                     Some(c) =>
 486                         if c > 0xFF {
 487                             panic!(err(2))
 488                         } else {
 489                             return (c as u8, 4)
 490                         },
 491                     None => panic!(err(3))
 492                 }
 493             }
 494         };
 495         (b, 2)
 496     }
 497 }
 498
 499 pub fn byte_str_lit(lit: &str) -> Rc<Vec<u8>> {
 500     let mut res = Vec::with_capacity(lit.len());
 501
 502     // FIXME #8372: This could be a for-loop if it didn't borrow the iterator
 503     let error = |i| format!("lexer should have rejected {} at {}", lit, i);
 504
 505     /// Eat everything up to a non-whitespace
 506     fn eat<I: Iterator<Item=(usize, u8)>>(it: &mut iter::Peekable<I>) {
 507         loop {
 508             match it.peek().map(|x| x.1) {
 509                 Some(b' ') | Some(b'\n') | Some(b'\r') | Some(b'\t') => {
 510                     it.next();
 511                 },
 512                 _ => { break; }
 513             }
 514         }
 515     }
 516
 517     // byte string literals *must* be ASCII, but the escapes don't have to be
 518     let mut chars = lit.bytes().enumerate().peekable();
 519     loop {
 520         match chars.next() {
 521             Some((i, b'\\')) => {
 522                 let em = error(i);
 523                 match chars.peek().expect(&em).1 {
 524                     b'\n' => eat(&mut chars),
 525                     b'\r' => {
 526                         chars.next();
 527                         if chars.peek().expect(&em).1 != b'\n' {
 528                             panic!("lexer accepted bare CR");
 529                         }
 530                         eat(&mut chars);
 531                     }
 532                     _ => {
 533                         // otherwise, a normal escape
 534                         let (c, n) = byte_lit(&lit[i..]);
 535                         // we don't need to move past the first \
 536                         for _ in 0..n - 1 {
 537                             chars.next();
 538                         }
 539                         res.push(c);
 540                     }
 541                 }
 542             },
 543             Some((i, b'\r')) => {
 544                 let em = error(i);
 545                 if chars.peek().expect(&em).1 != b'\n' {
 546                     panic!("lexer accepted bare CR");
 547                 }
 548                 chars.next();
 549                 res.push(b'\n');
 550             }
 551             Some((_, c)) => res.push(c),
 552             None => break,
 553         }
 554     }
 555
 556     Rc::new(res)
 557 }
 558
 559 pub fn integer_lit(s: &str, suffix: Option<Symbol>, diag: Option<(Span, &Handler)>)
 560                    -> Option<ast::LitKind> {
 561     // s can only be ascii, byte indexing is fine
 562
 563     let s2 = s.chars().filter(|&c| c != '_').collect::<String>();
 564     let mut s = &s2[..];
 565
 566     debug!("integer_lit: {}, {:?}", s, suffix);
 567
 568     let mut base = 10;
 569     let orig = s;
 570     let mut ty = ast::LitIntType::Unsuffixed;
 571
 572     if char_at(s, 0) == '0' && s.len() > 1 {
 573         match char_at(s, 1) {
 574             'x' => base = 16,
 575             'o' => base = 8,
 576             'b' => base = 2,
 577             _ => { }
 578         }
 579     }
 580
 581     // 1f64 and 2f32 etc. are valid float literals.
 582     if let Some(suf) = suffix {
 583         if looks_like_width_suffix(&['f'], &suf.as_str()) {
 584             let err = match base {
 585                 16 => Some("hexadecimal float literal is not supported"),
 586                 8 => Some("octal float literal is not supported"),
 587                 2 => Some("binary float literal is not supported"),
 588                 _ => None,
 589             };
 590             if let Some(err) = err {
 591                 err!(diag, |span, diag| diag.span_err(span, err));
 592             }
 593             return filtered_float_lit(Symbol::intern(s), Some(suf), diag)
 594         }
 595     }
 596
 597     if base != 10 {
 598         s = &s[2..];
 599     }
 600
 601     if let Some(suf) = suffix {
 602         if suf.as_str().is_empty() {
 603             err!(diag, |span, diag| diag.span_bug(span, "found empty literal suffix in Some"));
 604         }
 605         ty = match &*suf.as_str() {
 606             "isize" => ast::LitIntType::Signed(ast::IntTy::Is),
 607             "i8"  => ast::LitIntType::Signed(ast::IntTy::I8),
 608             "i16" => ast::LitIntType::Signed(ast::IntTy::I16),
 609             "i32" => ast::LitIntType::Signed(ast::IntTy::I32),
 610             "i64" => ast::LitIntType::Signed(ast::IntTy::I64),
 611             "i128" => ast::LitIntType::Signed(ast::IntTy::I128),
 612             "usize" => ast::LitIntType::Unsigned(ast::UintTy::Us),
 613             "u8"  => ast::LitIntType::Unsigned(ast::UintTy::U8),
 614             "u16" => ast::LitIntType::Unsigned(ast::UintTy::U16),
 615             "u32" => ast::LitIntType::Unsigned(ast::UintTy::U32),
 616             "u64" => ast::LitIntType::Unsigned(ast::UintTy::U64),
 617             "u128" => ast::LitIntType::Unsigned(ast::UintTy::U128),
 618             suf => {
 619                 // i<digits> and u<digits> look like widths, so lets
 620                 // give an error message along those lines
 621                 err!(diag, |span, diag| {
 622                     if looks_like_width_suffix(&['i', 'u'], suf) {
 623                         let msg = format!("invalid width `{}` for integer literal", &suf[1..]);
 624                         diag.struct_span_err(span, &msg)
 625                             .help("valid widths are 8, 16, 32, 64 and 128")
 626                             .emit();
 627                     } else {
 628                         let msg = format!("invalid suffix `{}` for numeric literal", suf);
 629                         diag.struct_span_err(span, &msg)
 630                             .help("the suffix must be one of the integral types \
 631                                    (`u32`, `isize`, etc)")
 632                             .emit();
 633                     }
 634                 });
 635
 636                 ty
 637             }
 638         }
 639     }
 640
 641     debug!("integer_lit: the type is {:?}, base {:?}, the new string is {:?}, the original \
 642            string was {:?}, the original suffix was {:?}", ty, base, s, orig, suffix);
 643
 644     Some(match u128::from_str_radix(s, base) {
 645         Ok(r) => ast::LitKind::Int(r, ty),
 646         Err(_) => {
 647             // small bases are lexed as if they were base 10, e.g, the string
 648             // might be `0b10201`. This will cause the conversion above to fail,
 649             // but these cases have errors in the lexer: we don't want to emit
 650             // two errors, and we especially don't want to emit this error since
 651             // it isn't necessarily true.
 652             let already_errored = base < 10 &&
 653                 s.chars().any(|c| c.to_digit(10).map_or(false, |d| d >= base));
 654
 655             if !already_errored {
 656                 err!(diag, |span, diag| diag.span_err(span, "int literal is too large"));
 657             }
 658             ast::LitKind::Int(0, ty)
 659         }
 660     })
 661 }
 662
 663 #[cfg(test)]
 664 mod tests {
 665     use super::*;
 666     use syntax_pos::{self, Span, BytePos, Pos, NO_EXPANSION};
 667     use codemap::Spanned;
 668     use ast::{self, Ident, PatKind};
 669     use abi::Abi;
 670     use attr::first_attr_value_str_by_name;
 671     use parse;
 672     use parse::parser::Parser;
 673     use print::pprust::item_to_string;
 674     use ptr::P;
 675     use tokenstream::{self, TokenTree};
 676     use util::parser_testing::{string_to_stream, string_to_parser};
 677     use util::parser_testing::{string_to_expr, string_to_item, string_to_stmt};
 678     use util::ThinVec;
 679
 680     // produce a syntax_pos::span
 681     fn sp(a: u32, b: u32) -> Span {
 682         Span::new(BytePos(a), BytePos(b), NO_EXPANSION)
 683     }
 684
 685     fn str2seg(s: &str, lo: u32, hi: u32) -> ast::PathSegment {
 686         ast::PathSegment::from_ident(Ident::from_str(s), sp(lo, hi))
 687     }
 688
 689     #[test] fn path_exprs_1() {
 690         assert!(string_to_expr("a".to_string()) ==
 691                    P(ast::Expr{
 692                     id: ast::DUMMY_NODE_ID,
 693                     node: ast::ExprKind::Path(None, ast::Path {
 694                         span: sp(0, 1),
 695                         segments: vec![str2seg("a", 0, 1)],
 696                     }),
 697                     span: sp(0, 1),
 698                     attrs: ThinVec::new(),
 699                    }))
 700     }
 701
 702     #[test] fn path_exprs_2 () {
 703         assert!(string_to_expr("::a::b".to_string()) ==
 704                    P(ast::Expr {
 705                     id: ast::DUMMY_NODE_ID,
 706                     node: ast::ExprKind::Path(None, ast::Path {
 707                         span: sp(0, 6),
 708                         segments: vec![ast::PathSegment::crate_root(sp(0, 2)),
 709                                        str2seg("a", 2, 3),
 710                                        str2seg("b", 5, 6)]
 711                     }),
 712                     span: sp(0, 6),
 713                     attrs: ThinVec::new(),
 714                    }))
 715     }
 716
 717     #[should_panic]
 718     #[test] fn bad_path_expr_1() {
 719         string_to_expr("::abc::def::return".to_string());
 720     }
 721
 722     // check the token-tree-ization of macros
 723     #[test]
 724     fn string_to_tts_macro () {
 725         let tts: Vec<_> =
 726             string_to_stream("macro_rules! zip (($a)=>($a))".to_string()).trees().collect();
 727         let tts: &[TokenTree] = &tts[..];
 728
 729         match (tts.len(), tts.get(0), tts.get(1), tts.get(2), tts.get(3)) {
 730             (
 731                 4,
 732                 Some(&TokenTree::Token(_, token::Ident(name_macro_rules))),
 733                 Some(&TokenTree::Token(_, token::Not)),
 734                 Some(&TokenTree::Token(_, token::Ident(name_zip))),
 735                 Some(&TokenTree::Delimited(_, ref macro_delimed)),
 736             )
 737             if name_macro_rules.name == "macro_rules"
 738             && name_zip.name == "zip" => {
 739                 let tts = &macro_delimed.stream().trees().collect::<Vec<_>>();
 740                 match (tts.len(), tts.get(0), tts.get(1), tts.get(2)) {
 741                     (
 742                         3,
 743                         Some(&TokenTree::Delimited(_, ref first_delimed)),
 744                         Some(&TokenTree::Token(_, token::FatArrow)),
 745                         Some(&TokenTree::Delimited(_, ref second_delimed)),
 746                     )
 747                     if macro_delimed.delim == token::Paren => {
 748                         let tts = &first_delimed.stream().trees().collect::<Vec<_>>();
 749                         match (tts.len(), tts.get(0), tts.get(1)) {
 750                             (
 751                                 2,
 752                                 Some(&TokenTree::Token(_, token::Dollar)),
 753                                 Some(&TokenTree::Token(_, token::Ident(ident))),
 754                             )
 755                             if first_delimed.delim == token::Paren && ident.name == "a" => {},
 756                             _ => panic!("value 3: {:?}", *first_delimed),
 757                         }
 758                         let tts = &second_delimed.stream().trees().collect::<Vec<_>>();
 759                         match (tts.len(), tts.get(0), tts.get(1)) {
 760                             (
 761                                 2,
 762                                 Some(&TokenTree::Token(_, token::Dollar)),
 763                                 Some(&TokenTree::Token(_, token::Ident(ident))),
 764                             )
 765                             if second_delimed.delim == token::Paren
 766                             && ident.name == "a" => {},
 767                             _ => panic!("value 4: {:?}", *second_delimed),
 768                         }
 769                     },
 770                     _ => panic!("value 2: {:?}", *macro_delimed),
 771                 }
 772             },
 773             _ => panic!("value: {:?}",tts),
 774         }
 775     }
 776
 777     #[test]
 778     fn string_to_tts_1() {
 779         let tts = string_to_stream("fn a (b : i32) { b; }".to_string());
 780
 781         let expected = TokenStream::concat(vec![
 782             TokenTree::Token(sp(0, 2), token::Ident(Ident::from_str("fn"))).into(),
 783             TokenTree::Token(sp(3, 4), token::Ident(Ident::from_str("a"))).into(),
 784             TokenTree::Delimited(
 785                 sp(5, 14),
 786                 tokenstream::Delimited {
 787                     delim: token::DelimToken::Paren,
 788                     tts: TokenStream::concat(vec![
 789                         TokenTree::Token(sp(6, 7), token::Ident(Ident::from_str("b"))).into(),
 790                         TokenTree::Token(sp(8, 9), token::Colon).into(),
 791                         TokenTree::Token(sp(10, 13), token::Ident(Ident::from_str("i32"))).into(),
 792                     ]).into(),
 793                 }).into(),
 794             TokenTree::Delimited(
 795                 sp(15, 21),
 796                 tokenstream::Delimited {
 797                     delim: token::DelimToken::Brace,
 798                     tts: TokenStream::concat(vec![
 799                         TokenTree::Token(sp(17, 18), token::Ident(Ident::from_str("b"))).into(),
 800                         TokenTree::Token(sp(18, 19), token::Semi).into(),
 801                     ]).into(),
 802                 }).into()
 803         ]);
 804
 805         assert_eq!(tts, expected);
 806     }
 807
 808     #[test] fn ret_expr() {
 809         assert!(string_to_expr("return d".to_string()) ==
 810                    P(ast::Expr{
 811                     id: ast::DUMMY_NODE_ID,
 812                     node:ast::ExprKind::Ret(Some(P(ast::Expr{
 813                         id: ast::DUMMY_NODE_ID,
 814                         node:ast::ExprKind::Path(None, ast::Path{
 815                             span: sp(7, 8),
 816                             segments: vec![str2seg("d", 7, 8)],
 817                         }),
 818                         span:sp(7,8),
 819                         attrs: ThinVec::new(),
 820                     }))),
 821                     span:sp(0,8),
 822                     attrs: ThinVec::new(),
 823                    }))
 824     }
 825
 826     #[test] fn parse_stmt_1 () {
 827         assert!(string_to_stmt("b;".to_string()) ==
 828                    Some(ast::Stmt {
 829                        node: ast::StmtKind::Expr(P(ast::Expr {
 830                            id: ast::DUMMY_NODE_ID,
 831                            node: ast::ExprKind::Path(None, ast::Path {
 832                                span:sp(0,1),
 833                                segments: vec![str2seg("b", 0, 1)],
 834                             }),
 835                            span: sp(0,1),
 836                            attrs: ThinVec::new()})),
 837                        id: ast::DUMMY_NODE_ID,
 838                        span: sp(0,1)}))
 839
 840     }
 841
 842     fn parser_done(p: Parser){
 843         assert_eq!(p.token.clone(), token::Eof);
 844     }
 845
 846     #[test] fn parse_ident_pat () {
 847         let sess = ParseSess::new(FilePathMapping::empty());
 848         let mut parser = string_to_parser(&sess, "b".to_string());
 849         assert!(panictry!(parser.parse_pat())
 850                 == P(ast::Pat{
 851                 id: ast::DUMMY_NODE_ID,
 852                 node: PatKind::Ident(ast::BindingMode::ByValue(ast::Mutability::Immutable),
 853                                     Spanned{ span:sp(0, 1),
 854                                              node: Ident::from_str("b")
 855                     },
 856                                     None),
 857                 span: sp(0,1)}));
 858         parser_done(parser);
 859     }
 860
 861     // check the contents of the tt manually:
 862     #[test] fn parse_fundecl () {
 863         // this test depends on the intern order of "fn" and "i32"
 864         let item = string_to_item("fn a (b : i32) { b; }".to_string()).map(|m| {
 865             m.map(|mut m| {
 866                 m.tokens = None;
 867                 m
 868             })
 869         });
 870         assert_eq!(item,
 871                   Some(
 872                       P(ast::Item{ident:Ident::from_str("a"),
 873                             attrs:Vec::new(),
 874                             id: ast::DUMMY_NODE_ID,
 875                             tokens: None,
 876                             node: ast::ItemKind::Fn(P(ast::FnDecl {
 877                                 inputs: vec![ast::Arg{
 878                                     ty: P(ast::Ty{id: ast::DUMMY_NODE_ID,
 879                                                   node: ast::TyKind::Path(None, ast::Path{
 880                                         span:sp(10,13),
 881                                         segments: vec![str2seg("i32", 10, 13)],
 882                                         }),
 883                                         span:sp(10,13)
 884                                     }),
 885                                     pat: P(ast::Pat {
 886                                         id: ast::DUMMY_NODE_ID,
 887                                         node: PatKind::Ident(
 888                                             ast::BindingMode::ByValue(
 889                                                 ast::Mutability::Immutable),
 890                                             Spanned{
 891                                                 span: sp(6,7),
 892                                                 node: Ident::from_str("b")},
 893                                             None
 894                                         ),
 895                                         span: sp(6,7)
 896                                     }),
 897                                         id: ast::DUMMY_NODE_ID
 898                                     }],
 899                                 output: ast::FunctionRetTy::Default(sp(15, 15)),
 900                                 variadic: false
 901                             }),
 902                                     ast::Unsafety::Normal,
 903                                     Spanned {
 904                                         span: sp(0,2),
 905                                         node: ast::Constness::NotConst,
 906                                     },
 907                                     Abi::Rust,
 908                                     ast::Generics{
 909                                         params: Vec::new(),
 910                                         where_clause: ast::WhereClause {
 911                                             id: ast::DUMMY_NODE_ID,
 912                                             predicates: Vec::new(),
 913                                             span: syntax_pos::DUMMY_SP,
 914                                         },
 915                                         span: syntax_pos::DUMMY_SP,
 916                                     },
 917                                     P(ast::Block {
 918                                         stmts: vec![ast::Stmt {
 919                                             node: ast::StmtKind::Semi(P(ast::Expr{
 920                                                 id: ast::DUMMY_NODE_ID,
 921                                                 node: ast::ExprKind::Path(None,
 922                                                       ast::Path{
 923                                                         span:sp(17,18),
 924                                                         segments: vec![str2seg("b", 17, 18)],
 925                                                       }),
 926                                                 span: sp(17,18),
 927                                                 attrs: ThinVec::new()})),
 928                                             id: ast::DUMMY_NODE_ID,
 929                                             span: sp(17,19)}],
 930                                         id: ast::DUMMY_NODE_ID,
 931                                         rules: ast::BlockCheckMode::Default, // no idea
 932                                         span: sp(15,21),
 933                                         recovered: false,
 934                                     })),
 935                             vis: ast::Visibility::Inherited,
 936                             span: sp(0,21)})));
 937     }
 938
 939     #[test] fn parse_use() {
 940         let use_s = "use foo::bar::baz;";
 941         let vitem = string_to_item(use_s.to_string()).unwrap();
 942         let vitem_s = item_to_string(&vitem);
 943         assert_eq!(&vitem_s[..], use_s);
 944
 945         let use_s = "use foo::bar as baz;";
 946         let vitem = string_to_item(use_s.to_string()).unwrap();
 947         let vitem_s = item_to_string(&vitem);
 948         assert_eq!(&vitem_s[..], use_s);
 949     }
 950
 951     #[test] fn parse_extern_crate() {
 952         let ex_s = "extern crate foo;";
 953         let vitem = string_to_item(ex_s.to_string()).unwrap();
 954         let vitem_s = item_to_string(&vitem);
 955         assert_eq!(&vitem_s[..], ex_s);
 956
 957         let ex_s = "extern crate foo as bar;";
 958         let vitem = string_to_item(ex_s.to_string()).unwrap();
 959         let vitem_s = item_to_string(&vitem);
 960         assert_eq!(&vitem_s[..], ex_s);
 961     }
 962
 963     fn get_spans_of_pat_idents(src: &str) -> Vec<Span> {
 964         let item = string_to_item(src.to_string()).unwrap();
 965
 966         struct PatIdentVisitor {
 967             spans: Vec<Span>
 968         }
 969         impl<'a> ::visit::Visitor<'a> for PatIdentVisitor {
 970             fn visit_pat(&mut self, p: &'a ast::Pat) {
 971                 match p.node {
 972                     PatKind::Ident(_ , ref spannedident, _) => {
 973                         self.spans.push(spannedident.span.clone());
 974                     }
 975                     _ => {
 976                         ::visit::walk_pat(self, p);
 977                     }
 978                 }
 979             }
 980         }
 981         let mut v = PatIdentVisitor { spans: Vec::new() };
 982         ::visit::walk_item(&mut v, &item);
 983         return v.spans;
 984     }
 985
 986     #[test] fn span_of_self_arg_pat_idents_are_correct() {
 987
 988         let srcs = ["impl z { fn a (&self, &myarg: i32) {} }",
 989                     "impl z { fn a (&mut self, &myarg: i32) {} }",
 990                     "impl z { fn a (&'a self, &myarg: i32) {} }",
 991                     "impl z { fn a (self, &myarg: i32) {} }",
 992                     "impl z { fn a (self: Foo, &myarg: i32) {} }",
 993                     ];
 994
 995         for &src in &srcs {
 996             let spans = get_spans_of_pat_idents(src);
 997             let (lo, hi) = (spans[0].lo(), spans[0].hi());
 998             assert!("self" == &src[lo.to_usize()..hi.to_usize()],
 999                     "\"{}\" != \"self\". src=\"{}\"",
1000                     &src[lo.to_usize()..hi.to_usize()], src)
1001         }
1002     }
1003
1004     #[test] fn parse_exprs () {
1005         // just make sure that they parse....
1006         string_to_expr("3 + 4".to_string());
1007         string_to_expr("a::z.froob(b,&(987+3))".to_string());
1008     }
1009
1010     #[test] fn attrs_fix_bug () {
1011         string_to_item("pub fn mk_file_writer(path: &Path, flags: &[FileFlag])
1012                    -> Result<Box<Writer>, String> {
1013     #[cfg(windows)]
1014     fn wb() -> c_int {
1015       (O_WRONLY | libc::consts::os::extra::O_BINARY) as c_int
1016     }
1017
1018     #[cfg(unix)]
1019     fn wb() -> c_int { O_WRONLY as c_int }
1020
1021     let mut fflags: c_int = wb();
1022 }".to_string());
1023     }
1024
1025     #[test] fn crlf_doc_comments() {
1026         let sess = ParseSess::new(FilePathMapping::empty());
1027
1028         let name = FileName::Custom("source".to_string());
1029         let source = "/// doc comment\r\nfn foo() {}".to_string();
1030         let item = parse_item_from_source_str(name.clone(), source, &sess)
1031             .unwrap().unwrap();
1032         let doc = first_attr_value_str_by_name(&item.attrs, "doc").unwrap();
1033         assert_eq!(doc, "/// doc comment");
1034
1035         let source = "/// doc comment\r\n/// line 2\r\nfn foo() {}".to_string();
1036         let item = parse_item_from_source_str(name.clone(), source, &sess)
1037             .unwrap().unwrap();
1038         let docs = item.attrs.iter().filter(|a| a.path == "doc")
1039                     .map(|a| a.value_str().unwrap().to_string()).collect::<Vec<_>>();
1040         let b: &[_] = &["/// doc comment".to_string(), "/// line 2".to_string()];
1041         assert_eq!(&docs[..], b);
1042
1043         let source = "/** doc comment\r\n *  with CRLF */\r\nfn foo() {}".to_string();
1044         let item = parse_item_from_source_str(name, source, &sess).unwrap().unwrap();
1045         let doc = first_attr_value_str_by_name(&item.attrs, "doc").unwrap();
1046         assert_eq!(doc, "/** doc comment\n *  with CRLF */");
1047     }
1048
1049     #[test]
1050     fn ttdelim_span() {
1051         let sess = ParseSess::new(FilePathMapping::empty());
1052         let expr = parse::parse_expr_from_source_str(PathBuf::from("foo").into(),
1053             "foo!( fn main() { body } )".to_string(), &sess).unwrap();
1054
1055         let tts: Vec<_> = match expr.node {
1056             ast::ExprKind::Mac(ref mac) => mac.node.stream().trees().collect(),
1057             _ => panic!("not a macro"),
1058         };
1059
1060         let span = tts.iter().rev().next().unwrap().span();
1061
1062         match sess.codemap().span_to_snippet(span) {
1063             Ok(s) => assert_eq!(&s[..], "{ body }"),
1064             Err(_) => panic!("could not get snippet"),
1065         }
1066     }
1067
1068     // This tests that when parsing a string (rather than a file) we don't try
1069     // and read in a file for a module declaration and just parse a stub.
1070     // See `recurse_into_file_modules` in the parser.
1071     #[test]
1072     fn out_of_line_mod() {
1073         let sess = ParseSess::new(FilePathMapping::empty());
1074         let item = parse_item_from_source_str(
1075             PathBuf::from("foo").into(),
1076             "mod foo { struct S; mod this_does_not_exist; }".to_owned(),
1077             &sess,
1078         ).unwrap().unwrap();
1079
1080         if let ast::ItemKind::Mod(ref m) = item.node {
1081             assert!(m.items.len() == 2);
1082         } else {
1083             panic!();
1084         }
1085     }
1086 }