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.
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.
14 // tjc note: Would be great to have a `match check` macro equivalent
17 #![allow(non_camel_case_types)]
21 use rustc::hir::def_id::{DefId, DefIndex};
24 use rustc::ty::subst::VecPerParamSpace;
25 use rustc::ty::{self, ToPredicate, Ty, TyCtxt, TypeFoldable};
32 use syntax::parse::token;
34 // Compact string representation for Ty values. API TyStr &
35 // parse_from_str. Extra parameters are for converting to/from def_ids in the
36 // data buffer. Whatever format you choose should not contain pipe characters.
38 pub type DefIdConvert<'a> = &'a mut FnMut(DefId) -> DefId;
40 pub struct TyDecoder<'a, 'tcx: 'a> {
44 tcx: TyCtxt<'a, 'tcx, 'tcx>,
45 conv_def_id: DefIdConvert<'a>,
48 impl<'a,'tcx> TyDecoder<'a,'tcx> {
49 pub fn with_doc(tcx: TyCtxt<'a, 'tcx, 'tcx>,
50 crate_num: ast::CrateNum,
52 conv: DefIdConvert<'a>)
53 -> TyDecoder<'a,'tcx> {
54 TyDecoder::new(doc.data, crate_num, doc.start, tcx, conv)
57 pub fn new(data: &'a [u8],
58 crate_num: ast::CrateNum,
60 tcx: TyCtxt<'a, 'tcx, 'tcx>,
61 conv: DefIdConvert<'a>)
62 -> TyDecoder<'a, 'tcx> {
72 pub fn position(&self) -> usize {
76 fn peek(&self) -> char {
77 self.data[self.pos] as char
80 fn next(&mut self) -> char {
81 let ch = self.data[self.pos] as char;
82 self.pos = self.pos + 1;
86 fn next_byte(&mut self) -> u8 {
87 let b = self.data[self.pos];
88 self.pos = self.pos + 1;
92 fn scan<F>(&mut self, mut is_last: F) -> &'a [u8]
93 where F: FnMut(char) -> bool,
95 let start_pos = self.pos;
96 debug!("scan: '{}' (start)", self.data[self.pos] as char);
97 while !is_last(self.data[self.pos] as char) {
99 debug!("scan: '{}'", self.data[self.pos] as char);
101 let end_pos = self.pos;
103 return &self.data[start_pos..end_pos];
106 fn parse_vuint(&mut self) -> usize {
107 let (value, bytes_read) = leb128::read_unsigned_leb128(self.data,
109 self.pos += bytes_read;
113 fn parse_name(&mut self, last: char) -> ast::Name {
114 fn is_last(b: char, c: char) -> bool { return c == b; }
115 let bytes = self.scan(|a| is_last(last, a));
116 token::intern(str::from_utf8(bytes).unwrap())
119 fn parse_size(&mut self) -> Option<usize> {
120 assert_eq!(self.next(), '/');
122 if self.peek() == '|' {
123 assert_eq!(self.next(), '|');
126 let n = self.parse_uint();
127 assert_eq!(self.next(), '|');
132 fn parse_vec_per_param_space<T, F>(&mut self, mut f: F) -> VecPerParamSpace<T> where
133 F: FnMut(&mut TyDecoder<'a, 'tcx>) -> T,
135 let mut r = VecPerParamSpace::empty();
136 for &space in &subst::ParamSpace::all() {
137 assert_eq!(self.next(), '[');
138 while self.peek() != ']' {
139 r.push(space, f(self));
141 assert_eq!(self.next(), ']');
146 pub fn parse_substs(&mut self) -> subst::Substs<'tcx> {
147 let regions = self.parse_vec_per_param_space(|this| this.parse_region());
148 let types = self.parse_vec_per_param_space(|this| this.parse_ty());
149 subst::Substs { types: types, regions: regions }
152 fn parse_bound_region(&mut self) -> ty::BoundRegion {
155 let id = self.parse_u32();
156 assert_eq!(self.next(), '|');
160 let def = self.parse_def();
161 let name = token::intern(&self.parse_str('|'));
162 let issue32330 = match self.next() {
164 assert_eq!(self.next(), ']');
165 ty::Issue32330::WontChange
168 ty::Issue32330::WillChange {
169 fn_def_id: self.parse_def(),
170 region_name: token::intern(&self.parse_str(']')),
173 c => panic!("expected n or y not {}", c)
175 ty::BrNamed(def, name, issue32330)
178 let id = self.parse_u32();
179 assert_eq!(self.next(), '|');
183 _ => bug!("parse_bound_region: bad input")
187 pub fn parse_region(&mut self) -> ty::Region {
190 assert_eq!(self.next(), '[');
191 let id = ty::DebruijnIndex::new(self.parse_u32());
192 assert_eq!(self.next(), '|');
193 let br = self.parse_bound_region();
194 assert_eq!(self.next(), ']');
195 ty::ReLateBound(id, br)
198 assert_eq!(self.next(), '[');
199 let space = self.parse_param_space();
200 assert_eq!(self.next(), '|');
201 let index = self.parse_u32();
202 assert_eq!(self.next(), '|');
203 let name = token::intern(&self.parse_str(']'));
204 ty::ReEarlyBound(ty::EarlyBoundRegion {
211 assert_eq!(self.next(), '[');
212 let scope = self.parse_scope();
213 assert_eq!(self.next(), '|');
214 let br = self.parse_bound_region();
215 assert_eq!(self.next(), ']');
216 ty::ReFree(ty::FreeRegion { scope: scope,
220 let scope = self.parse_scope();
221 assert_eq!(self.next(), '|');
227 _ => bug!("parse_region: bad input")
231 fn parse_scope(&mut self) -> region::CodeExtent {
232 self.tcx.region_maps.bogus_code_extent(match self.next() {
233 // This creates scopes with the wrong NodeId. This isn't
234 // actually a problem because scopes only exist *within*
235 // functions, and functions aren't loaded until trans which
236 // doesn't care about regions.
238 // May still be worth fixing though.
240 assert_eq!(self.next(), '[');
241 let fn_id = self.parse_uint() as ast::NodeId;
242 assert_eq!(self.next(), '|');
243 let body_id = self.parse_uint() as ast::NodeId;
244 assert_eq!(self.next(), ']');
245 region::CodeExtentData::CallSiteScope {
246 fn_id: fn_id, body_id: body_id
249 // This creates scopes with the wrong NodeId. (See note above.)
251 assert_eq!(self.next(), '[');
252 let fn_id = self.parse_uint() as ast::NodeId;
253 assert_eq!(self.next(), '|');
254 let body_id = self.parse_uint() as ast::NodeId;
255 assert_eq!(self.next(), ']');
256 region::CodeExtentData::ParameterScope {
257 fn_id: fn_id, body_id: body_id
261 let node_id = self.parse_uint() as ast::NodeId;
262 region::CodeExtentData::Misc(node_id)
265 let node_id = self.parse_uint() as ast::NodeId;
266 region::CodeExtentData::DestructionScope(node_id)
269 assert_eq!(self.next(), '[');
270 let node_id = self.parse_uint() as ast::NodeId;
271 assert_eq!(self.next(), '|');
272 let first_stmt_index = self.parse_u32();
273 assert_eq!(self.next(), ']');
274 let block_remainder = region::BlockRemainder {
275 block: node_id, first_statement_index: first_stmt_index,
277 region::CodeExtentData::Remainder(block_remainder)
279 _ => bug!("parse_scope: bad input")
283 fn parse_opt<T, F>(&mut self, f: F) -> Option<T>
284 where F: FnOnce(&mut TyDecoder<'a, 'tcx>) -> T,
288 's' => Some(f(self)),
289 _ => bug!("parse_opt: bad input")
293 fn parse_str(&mut self, term: char) -> String {
294 let mut result = String::new();
295 while self.peek() != term {
297 result.as_mut_vec().extend_from_slice(&[self.next_byte()])
304 pub fn parse_trait_ref(&mut self) -> ty::TraitRef<'tcx> {
305 let def = self.parse_def();
306 let substs = self.tcx.mk_substs(self.parse_substs());
307 ty::TraitRef {def_id: def, substs: substs}
310 pub fn parse_ty(&mut self) -> Ty<'tcx> {
313 'b' => return tcx.types.bool,
314 'i' => { /* eat the s of is */ self.next(); return tcx.types.isize },
315 'u' => { /* eat the s of us */ self.next(); return tcx.types.usize },
318 'b' => return tcx.types.u8,
319 'w' => return tcx.types.u16,
320 'l' => return tcx.types.u32,
321 'd' => return tcx.types.u64,
322 'B' => return tcx.types.i8,
323 'W' => return tcx.types.i16,
324 'L' => return tcx.types.i32,
325 'D' => return tcx.types.i64,
326 'f' => return tcx.types.f32,
327 'F' => return tcx.types.f64,
328 _ => bug!("parse_ty: bad numeric type")
331 'c' => return tcx.types.char,
333 assert_eq!(self.next(), '[');
334 let did = self.parse_def();
335 let substs = self.parse_substs();
336 assert_eq!(self.next(), ']');
337 let def = self.tcx.lookup_adt_def(did);
338 return tcx.mk_enum(def, self.tcx.mk_substs(substs));
341 assert_eq!(self.next(), '[');
342 let trait_ref = ty::Binder(self.parse_trait_ref());
343 let bounds = self.parse_existential_bounds();
344 assert_eq!(self.next(), ']');
345 return tcx.mk_trait(trait_ref, bounds);
348 assert_eq!(self.next(), '[');
349 let index = self.parse_u32();
350 assert_eq!(self.next(), '|');
351 let space = self.parse_param_space();
352 assert_eq!(self.next(), '|');
353 let name = token::intern(&self.parse_str(']'));
354 return tcx.mk_param(space, index, name);
356 '~' => return tcx.mk_box(self.parse_ty()),
357 '*' => return tcx.mk_ptr(self.parse_mt()),
359 let r = self.parse_region();
360 let mt = self.parse_mt();
361 return tcx.mk_ref(tcx.mk_region(r), mt);
364 let t = self.parse_ty();
365 return match self.parse_size() {
366 Some(n) => tcx.mk_array(t, n),
367 None => tcx.mk_slice(t)
374 assert_eq!(self.next(), '[');
375 let mut params = Vec::new();
376 while self.peek() != ']' { params.push(self.parse_ty()); }
377 self.pos = self.pos + 1;
378 return tcx.mk_tup(params);
381 let def_id = self.parse_def();
382 let substs = self.tcx.mk_substs(self.parse_substs());
383 return tcx.mk_fn_def(def_id, substs, self.parse_bare_fn_ty());
386 return tcx.mk_fn_ptr(self.parse_bare_fn_ty());
389 // This is a hacky little caching scheme. The idea is that if we encode
390 // the same type twice, the second (and third, and fourth...) time we will
391 // just write `#123`, where `123` is the offset in the metadata of the
392 // first appearance. Now when we are *decoding*, if we see a `#123`, we
393 // can first check a cache (`tcx.rcache`) for that offset. If we find something,
394 // we return it (modulo closure types, see below). But if not, then we
395 // jump to offset 123 and read the type from there.
397 let pos = self.parse_vuint();
398 let key = ty::CReaderCacheKey { cnum: self.krate, pos: pos };
399 if let Some(tt) = tcx.rcache.borrow().get(&key).cloned() {
400 // If there is a closure buried in the type some where, then we
401 // need to re-convert any def ids (see case 'k', below). That means
402 // we can't reuse the cached version.
403 if !tt.has_closure_types() {
408 let mut substate = TyDecoder::new(self.data,
413 let tt = substate.parse_ty();
414 tcx.rcache.borrow_mut().insert(key, tt);
418 let _ = self.parse_def();
419 let inner = self.parse_ty();
423 assert_eq!(self.next(), '[');
424 let did = self.parse_def();
425 let substs = self.parse_substs();
426 assert_eq!(self.next(), ']');
427 let def = self.tcx.lookup_adt_def(did);
428 return self.tcx.mk_struct(def, self.tcx.mk_substs(substs));
431 assert_eq!(self.next(), '[');
432 let did = self.parse_def();
433 let substs = self.parse_substs();
434 let mut tys = vec![];
435 while self.peek() != '.' {
436 tys.push(self.parse_ty());
438 assert_eq!(self.next(), '.');
439 assert_eq!(self.next(), ']');
440 return self.tcx.mk_closure(did, self.tcx.mk_substs(substs), tys);
443 assert_eq!(self.next(), '[');
444 let trait_ref = self.parse_trait_ref();
445 let name = token::intern(&self.parse_str(']'));
446 return tcx.mk_projection(trait_ref, name);
449 assert_eq!(self.next(), '[');
450 let def_id = self.parse_def();
451 let substs = self.parse_substs();
452 assert_eq!(self.next(), ']');
453 return self.tcx.mk_anon(def_id, self.tcx.mk_substs(substs));
456 return tcx.types.err;
458 c => { bug!("unexpected char in type string: {}", c);}
462 fn parse_mutability(&mut self) -> hir::Mutability {
464 'm' => { self.next(); hir::MutMutable }
465 _ => { hir::MutImmutable }
469 fn parse_mt(&mut self) -> ty::TypeAndMut<'tcx> {
470 let m = self.parse_mutability();
471 ty::TypeAndMut { ty: self.parse_ty(), mutbl: m }
474 fn parse_def(&mut self) -> DefId {
475 let def_id = parse_defid(self.scan(|c| c == '|'));
476 return (self.conv_def_id)(def_id);
479 fn parse_uint(&mut self) -> usize {
482 let cur = self.peek();
483 if cur < '0' || cur > '9' { return n; }
484 self.pos = self.pos + 1;
486 n += (cur as usize) - ('0' as usize);
490 fn parse_u32(&mut self) -> u32 {
491 let n = self.parse_uint();
493 assert_eq!(m as usize, n);
497 fn parse_param_space(&mut self) -> subst::ParamSpace {
498 subst::ParamSpace::from_uint(self.parse_uint())
501 fn parse_abi_set(&mut self) -> abi::Abi {
502 assert_eq!(self.next(), '[');
503 let bytes = self.scan(|c| c == ']');
504 let abi_str = str::from_utf8(bytes).unwrap();
505 abi::lookup(&abi_str[..]).expect(abi_str)
508 pub fn parse_closure_ty(&mut self) -> ty::ClosureTy<'tcx> {
509 let unsafety = parse_unsafety(self.next());
510 let sig = self.parse_sig();
511 let abi = self.parse_abi_set();
519 pub fn parse_bare_fn_ty(&mut self) -> &'tcx ty::BareFnTy<'tcx> {
520 let unsafety = parse_unsafety(self.next());
521 let abi = self.parse_abi_set();
522 let sig = self.parse_sig();
523 self.tcx.mk_bare_fn(ty::BareFnTy {
530 fn parse_sig(&mut self) -> ty::PolyFnSig<'tcx> {
531 assert_eq!(self.next(), '[');
532 let mut inputs = Vec::new();
533 while self.peek() != ']' {
534 inputs.push(self.parse_ty());
536 self.pos += 1; // eat the ']'
537 let variadic = match self.next() {
540 r => bug!("bad variadic: {}", r),
542 let output = match self.peek() {
547 _ => ty::FnConverging(self.parse_ty())
549 ty::Binder(ty::FnSig {inputs: inputs,
554 pub fn parse_predicate(&mut self) -> ty::Predicate<'tcx> {
556 't' => ty::Binder(self.parse_trait_ref()).to_predicate(),
557 'e' => ty::Binder(ty::EquatePredicate(self.parse_ty(),
558 self.parse_ty())).to_predicate(),
559 'r' => ty::Binder(ty::OutlivesPredicate(self.parse_region(),
560 self.parse_region())).to_predicate(),
561 'o' => ty::Binder(ty::OutlivesPredicate(self.parse_ty(),
562 self.parse_region())).to_predicate(),
563 'p' => ty::Binder(self.parse_projection_predicate()).to_predicate(),
564 'w' => ty::Predicate::WellFormed(self.parse_ty()),
566 let def_id = self.parse_def();
567 assert_eq!(self.next(), '|');
568 ty::Predicate::ObjectSafe(def_id)
571 let def_id = self.parse_def();
572 assert_eq!(self.next(), '|');
573 let kind = match self.next() {
574 'f' => ty::ClosureKind::Fn,
575 'm' => ty::ClosureKind::FnMut,
576 'o' => ty::ClosureKind::FnOnce,
577 c => bug!("Encountered invalid character in metadata: {}", c)
579 assert_eq!(self.next(), '|');
580 ty::Predicate::ClosureKind(def_id, kind)
582 c => bug!("Encountered invalid character in metadata: {}", c)
586 fn parse_projection_predicate(&mut self) -> ty::ProjectionPredicate<'tcx> {
587 ty::ProjectionPredicate {
588 projection_ty: ty::ProjectionTy {
589 trait_ref: self.parse_trait_ref(),
590 item_name: token::intern(&self.parse_str('|')),
596 pub fn parse_type_param_def(&mut self) -> ty::TypeParameterDef<'tcx> {
597 let name = self.parse_name(':');
598 let def_id = self.parse_def();
599 let space = self.parse_param_space();
600 assert_eq!(self.next(), '|');
601 let index = self.parse_u32();
602 assert_eq!(self.next(), '|');
603 let default_def_id = self.parse_def();
604 let default = self.parse_opt(|this| this.parse_ty());
605 let object_lifetime_default = self.parse_object_lifetime_default();
607 ty::TypeParameterDef {
612 default_def_id: default_def_id,
614 object_lifetime_default: object_lifetime_default,
618 pub fn parse_region_param_def(&mut self) -> ty::RegionParameterDef {
619 let name = self.parse_name(':');
620 let def_id = self.parse_def();
621 let space = self.parse_param_space();
622 assert_eq!(self.next(), '|');
623 let index = self.parse_u32();
624 assert_eq!(self.next(), '|');
625 let mut bounds = vec![];
628 'R' => bounds.push(self.parse_region()),
631 bug!("parse_region_param_def: bad bounds ('{}')", c)
635 ty::RegionParameterDef {
645 fn parse_object_lifetime_default(&mut self) -> ty::ObjectLifetimeDefault {
647 'a' => ty::ObjectLifetimeDefault::Ambiguous,
648 'b' => ty::ObjectLifetimeDefault::BaseDefault,
650 let region = self.parse_region();
651 ty::ObjectLifetimeDefault::Specific(region)
653 _ => bug!("parse_object_lifetime_default: bad input")
657 pub fn parse_existential_bounds(&mut self) -> ty::ExistentialBounds<'tcx> {
658 let builtin_bounds = self.parse_builtin_bounds();
659 let region_bound = self.parse_region();
660 let mut projection_bounds = Vec::new();
665 projection_bounds.push(ty::Binder(self.parse_projection_predicate()));
669 bug!("parse_bounds: bad bounds ('{}')", c)
674 ty::ExistentialBounds::new(
675 region_bound, builtin_bounds, projection_bounds)
678 fn parse_builtin_bounds(&mut self) -> ty::BuiltinBounds {
679 let mut builtin_bounds = ty::BuiltinBounds::empty();
683 builtin_bounds.insert(ty::BoundSend);
686 builtin_bounds.insert(ty::BoundSized);
689 builtin_bounds.insert(ty::BoundCopy);
692 builtin_bounds.insert(ty::BoundSync);
695 return builtin_bounds;
698 bug!("parse_bounds: bad builtin bounds ('{}')", c)
705 // Rust metadata parsing
706 fn parse_defid(buf: &[u8]) -> DefId {
707 let mut colon_idx = 0;
709 while colon_idx < len && buf[colon_idx] != ':' as u8 { colon_idx += 1; }
710 if colon_idx == len {
711 error!("didn't find ':' when parsing def id");
715 let crate_part = &buf[0..colon_idx];
716 let def_part = &buf[colon_idx + 1..len];
718 let crate_num = match str::from_utf8(crate_part).ok().and_then(|s| {
719 s.parse::<usize>().ok()
721 Some(cn) => cn as ast::CrateNum,
722 None => bug!("internal error: parse_defid: crate number expected, found {:?}",
725 let def_num = match str::from_utf8(def_part).ok().and_then(|s| {
726 s.parse::<usize>().ok()
729 None => bug!("internal error: parse_defid: id expected, found {:?}",
732 let index = DefIndex::new(def_num);
733 DefId { krate: crate_num, index: index }
736 fn parse_unsafety(c: char) -> hir::Unsafety {
738 'u' => hir::Unsafety::Unsafe,
739 'n' => hir::Unsafety::Normal,
740 _ => bug!("parse_unsafety: bad unsafety {}", c)