1use std::fmt::Write;
2use std::hash::Hasher;
3use std::iter;
4use std::ops::Range;
5
6use rustc_abi::{ExternAbi, Integer};
7use rustc_data_structures::base_n::ToBaseN;
8use rustc_data_structures::fx::FxHashMap;
9use rustc_data_structures::intern::Interned;
10use rustc_data_structures::stable_hasher::StableHasher;
11use rustc_hashes::Hash64;
12use rustc_hir as hir;
13use rustc_hir::def::CtorKind;
14use rustc_hir::def_id::{CrateNum, DefId};
15use rustc_hir::definitions::{DefPathData, DisambiguatedDefPathData};
16use rustc_middle::bug;
17use rustc_middle::ty::layout::IntegerExt;
18use rustc_middle::ty::print::{Print, PrintError, Printer};
19use rustc_middle::ty::{
20 self, FloatTy, GenericArg, GenericArgKind, Instance, IntTy, ReifyReason, Ty, TyCtxt,
21 TypeVisitable, TypeVisitableExt, UintTy,
22};
23use rustc_span::sym;
24
25pub(super) fn mangle<'tcx>(
26 tcx: TyCtxt<'tcx>,
27 instance: Instance<'tcx>,
28 instantiating_crate: Option<CrateNum>,
29 is_exportable: bool,
30) -> String {
31 let def_id = instance.def_id();
32 let args = tcx.normalize_erasing_regions(ty::TypingEnv::fully_monomorphized(), instance.args);
34
35 let prefix = "_R";
36 let mut cx: SymbolMangler<'_> = SymbolMangler {
37 tcx,
38 start_offset: prefix.len(),
39 is_exportable,
40 paths: FxHashMap::default(),
41 types: FxHashMap::default(),
42 consts: FxHashMap::default(),
43 binders: vec![],
44 out: String::from(prefix),
45 };
46
47 let shim_kind = match instance.def {
49 ty::InstanceKind::ThreadLocalShim(_) => Some("tls"),
50 ty::InstanceKind::VTableShim(_) => Some("vtable"),
51 ty::InstanceKind::ReifyShim(_, None) => Some("reify"),
52 ty::InstanceKind::ReifyShim(_, Some(ReifyReason::FnPtr)) => Some("reify_fnptr"),
53 ty::InstanceKind::ReifyShim(_, Some(ReifyReason::Vtable)) => Some("reify_vtable"),
54
55 ty::InstanceKind::ConstructCoroutineInClosureShim { receiver_by_ref: true, .. } => {
58 Some("by_move")
59 }
60 ty::InstanceKind::ConstructCoroutineInClosureShim { receiver_by_ref: false, .. } => {
61 Some("by_ref")
62 }
63 ty::InstanceKind::FutureDropPollShim(_, _, _) => Some("drop"),
64 _ => None,
65 };
66
67 if let ty::InstanceKind::AsyncDropGlue(_, ty) = instance.def {
68 let ty::Coroutine(_, cor_args) = ty.kind() else {
69 bug!();
70 };
71 let drop_ty = cor_args.first().unwrap().expect_ty();
72 cx.print_def_path(def_id, tcx.mk_args(&[GenericArg::from(drop_ty)])).unwrap()
73 } else if let Some(shim_kind) = shim_kind {
74 cx.path_append_ns(|cx| cx.print_def_path(def_id, args), 'S', 0, shim_kind).unwrap()
75 } else {
76 cx.print_def_path(def_id, args).unwrap()
77 };
78 if let Some(instantiating_crate) = instantiating_crate {
79 cx.print_def_path(instantiating_crate.as_def_id(), &[]).unwrap();
80 }
81 std::mem::take(&mut cx.out)
82}
83
84pub fn mangle_internal_symbol<'tcx>(tcx: TyCtxt<'tcx>, item_name: &str) -> String {
85 if item_name == "rust_eh_personality" {
86 return "rust_eh_personality".to_owned();
88 }
89
90 let prefix = "_R";
91 let mut cx: SymbolMangler<'_> = SymbolMangler {
92 tcx,
93 start_offset: prefix.len(),
94 is_exportable: false,
95 paths: FxHashMap::default(),
96 types: FxHashMap::default(),
97 consts: FxHashMap::default(),
98 binders: vec![],
99 out: String::from(prefix),
100 };
101
102 cx.path_append_ns(
103 |cx| {
104 cx.push("C");
105 cx.push_disambiguator({
106 let mut hasher = StableHasher::new();
107 hasher.write(tcx.sess.cfg_version.as_bytes());
113
114 let hash: Hash64 = hasher.finish();
115 hash.as_u64()
116 });
117 cx.push_ident("__rustc");
118 Ok(())
119 },
120 'v',
121 0,
122 item_name,
123 )
124 .unwrap();
125
126 std::mem::take(&mut cx.out)
127}
128
129pub(super) fn mangle_typeid_for_trait_ref<'tcx>(
130 tcx: TyCtxt<'tcx>,
131 trait_ref: ty::ExistentialTraitRef<'tcx>,
132) -> String {
133 let mut cx = SymbolMangler {
135 tcx,
136 start_offset: 0,
137 is_exportable: false,
138 paths: FxHashMap::default(),
139 types: FxHashMap::default(),
140 consts: FxHashMap::default(),
141 binders: vec![],
142 out: String::new(),
143 };
144 cx.print_def_path(trait_ref.def_id, &[]).unwrap();
145 std::mem::take(&mut cx.out)
146}
147
148struct BinderLevel {
149 lifetime_depths: Range<u32>,
160}
161
162struct SymbolMangler<'tcx> {
163 tcx: TyCtxt<'tcx>,
164 binders: Vec<BinderLevel>,
165 out: String,
166 is_exportable: bool,
167
168 start_offset: usize,
170 paths: FxHashMap<(DefId, &'tcx [GenericArg<'tcx>]), usize>,
172 types: FxHashMap<Ty<'tcx>, usize>,
173 consts: FxHashMap<ty::Const<'tcx>, usize>,
174}
175
176impl<'tcx> SymbolMangler<'tcx> {
177 fn push(&mut self, s: &str) {
178 self.out.push_str(s);
179 }
180
181 fn push_integer_62(&mut self, x: u64) {
187 push_integer_62(x, &mut self.out)
188 }
189
190 fn push_opt_integer_62(&mut self, tag: &str, x: u64) {
195 if let Some(x) = x.checked_sub(1) {
196 self.push(tag);
197 self.push_integer_62(x);
198 }
199 }
200
201 fn push_disambiguator(&mut self, dis: u64) {
202 self.push_opt_integer_62("s", dis);
203 }
204
205 fn push_ident(&mut self, ident: &str) {
206 push_ident(ident, &mut self.out)
207 }
208
209 fn path_append_ns(
210 &mut self,
211 print_prefix: impl FnOnce(&mut Self) -> Result<(), PrintError>,
212 ns: char,
213 disambiguator: u64,
214 name: &str,
215 ) -> Result<(), PrintError> {
216 self.push("N");
217 self.out.push(ns);
218 print_prefix(self)?;
219 self.push_disambiguator(disambiguator);
220 self.push_ident(name);
221 Ok(())
222 }
223
224 fn print_backref(&mut self, i: usize) -> Result<(), PrintError> {
225 self.push("B");
226 self.push_integer_62((i - self.start_offset) as u64);
227 Ok(())
228 }
229
230 fn wrap_binder<T>(
231 &mut self,
232 value: &ty::Binder<'tcx, T>,
233 print_value: impl FnOnce(&mut Self, &T) -> Result<(), PrintError>,
234 ) -> Result<(), PrintError>
235 where
236 T: TypeVisitable<TyCtxt<'tcx>>,
237 {
238 let mut lifetime_depths =
239 self.binders.last().map(|b| b.lifetime_depths.end).map_or(0..0, |i| i..i);
240
241 let lifetimes = value
243 .bound_vars()
244 .iter()
245 .filter(|var| matches!(var, ty::BoundVariableKind::Region(..)))
246 .count() as u32;
247
248 self.push_opt_integer_62("G", lifetimes as u64);
249 lifetime_depths.end += lifetimes;
250
251 self.binders.push(BinderLevel { lifetime_depths });
252 print_value(self, value.as_ref().skip_binder())?;
253 self.binders.pop();
254
255 Ok(())
256 }
257
258 fn print_pat(&mut self, pat: ty::Pattern<'tcx>) -> Result<(), std::fmt::Error> {
259 Ok(match *pat {
260 ty::PatternKind::Range { start, end } => {
261 let consts = [start, end];
262 for ct in consts {
263 Ty::new_array_with_const_len(self.tcx, self.tcx.types.unit, ct).print(self)?;
264 }
265 }
266 ty::PatternKind::Or(patterns) => {
267 for pat in patterns {
268 self.print_pat(pat)?;
269 }
270 }
271 })
272 }
273}
274
275impl<'tcx> Printer<'tcx> for SymbolMangler<'tcx> {
276 fn tcx(&self) -> TyCtxt<'tcx> {
277 self.tcx
278 }
279
280 fn print_def_path(
281 &mut self,
282 def_id: DefId,
283 args: &'tcx [GenericArg<'tcx>],
284 ) -> Result<(), PrintError> {
285 if let Some(&i) = self.paths.get(&(def_id, args)) {
286 return self.print_backref(i);
287 }
288 let start = self.out.len();
289
290 self.default_print_def_path(def_id, args)?;
291
292 if !args.iter().any(|k| k.has_escaping_bound_vars()) {
295 self.paths.insert((def_id, args), start);
296 }
297 Ok(())
298 }
299
300 fn print_impl_path(
301 &mut self,
302 impl_def_id: DefId,
303 args: &'tcx [GenericArg<'tcx>],
304 ) -> Result<(), PrintError> {
305 let key = self.tcx.def_key(impl_def_id);
306 let parent_def_id = DefId { index: key.parent.unwrap(), ..impl_def_id };
307
308 let self_ty = self.tcx.type_of(impl_def_id);
309 let impl_trait_ref = self.tcx.impl_trait_ref(impl_def_id);
310 let generics = self.tcx.generics_of(impl_def_id);
311 let (typing_env, mut self_ty, mut impl_trait_ref) = if generics.count() > args.len()
325 || &args[..generics.count()]
326 == self
327 .tcx
328 .erase_regions(ty::GenericArgs::identity_for_item(self.tcx, impl_def_id))
329 .as_slice()
330 {
331 (
332 ty::TypingEnv::post_analysis(self.tcx, impl_def_id),
333 self_ty.instantiate_identity(),
334 impl_trait_ref.map(|impl_trait_ref| impl_trait_ref.instantiate_identity()),
335 )
336 } else {
337 assert!(
338 !args.has_non_region_param(),
339 "should not be mangling partially substituted \
340 polymorphic instance: {impl_def_id:?} {args:?}"
341 );
342 (
343 ty::TypingEnv::fully_monomorphized(),
344 self_ty.instantiate(self.tcx, args),
345 impl_trait_ref.map(|impl_trait_ref| impl_trait_ref.instantiate(self.tcx, args)),
346 )
347 };
348
349 match &mut impl_trait_ref {
350 Some(impl_trait_ref) => {
351 assert_eq!(impl_trait_ref.self_ty(), self_ty);
352 *impl_trait_ref = self.tcx.normalize_erasing_regions(typing_env, *impl_trait_ref);
353 self_ty = impl_trait_ref.self_ty();
354 }
355 None => {
356 self_ty = self.tcx.normalize_erasing_regions(typing_env, self_ty);
357 }
358 }
359
360 self.push(match impl_trait_ref {
361 Some(_) => "X",
362 None => "M",
363 });
364
365 if impl_trait_ref.is_some() && args.iter().any(|a| a.has_non_region_param()) {
368 self.path_generic_args(
369 |this| {
370 this.path_append_ns(
371 |cx| cx.print_def_path(parent_def_id, &[]),
372 'I',
373 key.disambiguated_data.disambiguator as u64,
374 "",
375 )
376 },
377 args,
378 )?;
379 } else {
380 let exported_impl_order = self.tcx.stable_order_of_exportable_impls(impl_def_id.krate);
381 let disambiguator = match self.is_exportable {
382 true => exported_impl_order[&impl_def_id] as u64,
383 false => {
384 exported_impl_order.len() as u64 + key.disambiguated_data.disambiguator as u64
385 }
386 };
387 self.push_disambiguator(disambiguator);
388 self.print_def_path(parent_def_id, &[])?;
389 }
390
391 self_ty.print(self)?;
392
393 if let Some(trait_ref) = impl_trait_ref {
394 self.print_def_path(trait_ref.def_id, trait_ref.args)?;
395 }
396
397 Ok(())
398 }
399
400 fn print_region(&mut self, region: ty::Region<'_>) -> Result<(), PrintError> {
401 let i = match region.kind() {
402 ty::ReErased => 0,
405
406 ty::ReBound(debruijn, ty::BoundRegion { var, kind: ty::BoundRegionKind::Anon }) => {
409 let binder = &self.binders[self.binders.len() - 1 - debruijn.index()];
410 let depth = binder.lifetime_depths.start + var.as_u32();
411
412 1 + (self.binders.last().unwrap().lifetime_depths.end - 1 - depth)
413 }
414
415 _ => bug!("symbol_names: non-erased region `{:?}`", region),
416 };
417 self.push("L");
418 self.push_integer_62(i as u64);
419 Ok(())
420 }
421
422 fn print_type(&mut self, ty: Ty<'tcx>) -> Result<(), PrintError> {
423 let basic_type = match ty.kind() {
425 ty::Bool => "b",
426 ty::Char => "c",
427 ty::Str => "e",
428 ty::Tuple(_) if ty.is_unit() => "u",
429 ty::Int(IntTy::I8) => "a",
430 ty::Int(IntTy::I16) => "s",
431 ty::Int(IntTy::I32) => "l",
432 ty::Int(IntTy::I64) => "x",
433 ty::Int(IntTy::I128) => "n",
434 ty::Int(IntTy::Isize) => "i",
435 ty::Uint(UintTy::U8) => "h",
436 ty::Uint(UintTy::U16) => "t",
437 ty::Uint(UintTy::U32) => "m",
438 ty::Uint(UintTy::U64) => "y",
439 ty::Uint(UintTy::U128) => "o",
440 ty::Uint(UintTy::Usize) => "j",
441 ty::Float(FloatTy::F16) => "C3f16",
442 ty::Float(FloatTy::F32) => "f",
443 ty::Float(FloatTy::F64) => "d",
444 ty::Float(FloatTy::F128) => "C4f128",
445 ty::Never => "z",
446
447 ty::Param(_) => "p",
450
451 ty::Bound(..) | ty::Placeholder(_) | ty::Infer(_) | ty::Error(_) => bug!(),
452
453 _ => "",
454 };
455 if !basic_type.is_empty() {
456 self.push(basic_type);
457 return Ok(());
458 }
459
460 if let Some(&i) = self.types.get(&ty) {
461 return self.print_backref(i);
462 }
463 let start = self.out.len();
464
465 match *ty.kind() {
466 ty::Bool | ty::Char | ty::Str | ty::Int(_) | ty::Uint(_) | ty::Float(_) | ty::Never => {
468 unreachable!()
469 }
470 ty::Tuple(_) if ty.is_unit() => unreachable!(),
471
472 ty::Param(_) | ty::Bound(..) | ty::Placeholder(_) | ty::Infer(_) | ty::Error(_) => {
474 unreachable!()
475 }
476
477 ty::Ref(r, ty, mutbl) => {
478 self.push(match mutbl {
479 hir::Mutability::Not => "R",
480 hir::Mutability::Mut => "Q",
481 });
482 if !r.is_erased() {
483 r.print(self)?;
484 }
485 ty.print(self)?;
486 }
487
488 ty::RawPtr(ty, mutbl) => {
489 self.push(match mutbl {
490 hir::Mutability::Not => "P",
491 hir::Mutability::Mut => "O",
492 });
493 ty.print(self)?;
494 }
495
496 ty::Pat(ty, pat) => {
497 self.push("T");
500 ty.print(self)?;
501 self.print_pat(pat)?;
502 self.push("E");
503 }
504
505 ty::Array(ty, len) => {
506 self.push("A");
507 ty.print(self)?;
508 self.print_const(len)?;
509 }
510 ty::Slice(ty) => {
511 self.push("S");
512 ty.print(self)?;
513 }
514
515 ty::Tuple(tys) => {
516 self.push("T");
517 for ty in tys.iter() {
518 ty.print(self)?;
519 }
520 self.push("E");
521 }
522
523 ty::Adt(ty::AdtDef(Interned(&ty::AdtDefData { did: def_id, .. }, _)), args)
525 | ty::FnDef(def_id, args)
526 | ty::Closure(def_id, args)
527 | ty::CoroutineClosure(def_id, args)
528 | ty::Coroutine(def_id, args) => {
529 self.print_def_path(def_id, args)?;
530 }
531
532 ty::Alias(ty::Projection, ty::AliasTy { def_id, args, .. }) => {
535 self.print_def_path(def_id, args)?;
536 }
537
538 ty::Foreign(def_id) => {
539 self.print_def_path(def_id, &[])?;
540 }
541
542 ty::FnPtr(sig_tys, hdr) => {
543 let sig = sig_tys.with(hdr);
544 self.push("F");
545 self.wrap_binder(&sig, |cx, sig| {
546 if sig.safety.is_unsafe() {
547 cx.push("U");
548 }
549 match sig.abi {
550 ExternAbi::Rust => {}
551 ExternAbi::C { unwind: false } => cx.push("KC"),
552 abi => {
553 cx.push("K");
554 let name = abi.as_str();
555 if name.contains('-') {
556 cx.push_ident(&name.replace('-', "_"));
557 } else {
558 cx.push_ident(name);
559 }
560 }
561 }
562 for &ty in sig.inputs() {
563 ty.print(cx)?;
564 }
565 if sig.c_variadic {
566 cx.push("v");
567 }
568 cx.push("E");
569 sig.output().print(cx)
570 })?;
571 }
572
573 ty::UnsafeBinder(..) => todo!(),
575
576 ty::Dynamic(predicates, r, kind) => {
577 self.push(match kind {
578 ty::Dyn => "D",
579 ty::DynStar => "D*",
581 });
582 self.print_dyn_existential(predicates)?;
583 r.print(self)?;
584 }
585
586 ty::Alias(..) => bug!("symbol_names: unexpected alias"),
587 ty::CoroutineWitness(..) => bug!("symbol_names: unexpected `CoroutineWitness`"),
588 }
589
590 if !ty.has_escaping_bound_vars() {
593 self.types.insert(ty, start);
594 }
595 Ok(())
596 }
597
598 fn print_dyn_existential(
599 &mut self,
600 predicates: &'tcx ty::List<ty::PolyExistentialPredicate<'tcx>>,
601 ) -> Result<(), PrintError> {
602 self.wrap_binder(&predicates[0], |cx, _| {
629 for predicate in predicates.iter() {
630 match predicate.as_ref().skip_binder() {
635 ty::ExistentialPredicate::Trait(trait_ref) => {
636 let dummy_self = Ty::new_fresh(cx.tcx, 0);
638 let trait_ref = trait_ref.with_self_ty(cx.tcx, dummy_self);
639 cx.print_def_path(trait_ref.def_id, trait_ref.args)?;
640 }
641 ty::ExistentialPredicate::Projection(projection) => {
642 let name = cx.tcx.associated_item(projection.def_id).name();
643 cx.push("p");
644 cx.push_ident(name.as_str());
645 match projection.term.kind() {
646 ty::TermKind::Ty(ty) => ty.print(cx),
647 ty::TermKind::Const(c) => c.print(cx),
648 }?;
649 }
650 ty::ExistentialPredicate::AutoTrait(def_id) => {
651 cx.print_def_path(*def_id, &[])?;
652 }
653 }
654 }
655 Ok(())
656 })?;
657
658 self.push("E");
659 Ok(())
660 }
661
662 fn print_const(&mut self, ct: ty::Const<'tcx>) -> Result<(), PrintError> {
663 let cv = match ct.kind() {
665 ty::ConstKind::Value(cv) => cv,
666
667 ty::ConstKind::Param(_) => {
670 self.push("p");
672 return Ok(());
673 }
674
675 ty::ConstKind::Unevaluated(ty::UnevaluatedConst { def, args, .. }) => {
678 return self.print_def_path(def, args);
679 }
680
681 ty::ConstKind::Expr(_)
682 | ty::ConstKind::Infer(_)
683 | ty::ConstKind::Bound(..)
684 | ty::ConstKind::Placeholder(_)
685 | ty::ConstKind::Error(_) => bug!(),
686 };
687
688 if let Some(&i) = self.consts.get(&ct) {
689 self.print_backref(i)?;
690 return Ok(());
691 }
692
693 let ty::Value { ty: ct_ty, valtree } = cv;
694 let start = self.out.len();
695
696 match ct_ty.kind() {
697 ty::Uint(_) | ty::Int(_) | ty::Bool | ty::Char => {
698 ct_ty.print(self)?;
699
700 let mut bits = cv
701 .try_to_bits(self.tcx, ty::TypingEnv::fully_monomorphized())
702 .expect("expected const to be monomorphic");
703
704 if let ty::Int(ity) = ct_ty.kind() {
706 let val =
707 Integer::from_int_ty(&self.tcx, *ity).size().sign_extend(bits) as i128;
708 if val < 0 {
709 self.push("n");
710 }
711 bits = val.unsigned_abs();
712 }
713
714 let _ = write!(self.out, "{bits:x}_");
715 }
716
717 ty::Str => {
719 let tcx = self.tcx();
720 let ref_ty = Ty::new_imm_ref(tcx, tcx.lifetimes.re_static, ct_ty);
723 let cv = ty::Value { ty: ref_ty, valtree };
724 let slice = cv.try_to_raw_bytes(tcx).unwrap_or_else(|| {
725 bug!("expected to get raw bytes from valtree {:?} for type {:}", valtree, ct_ty)
726 });
727 let s = std::str::from_utf8(slice).expect("non utf8 str from MIR interpreter");
728
729 self.push("e");
731
732 for byte in s.bytes() {
734 let _ = write!(self.out, "{byte:02x}");
735 }
736
737 self.push("_");
738 }
739
740 ty::Ref(_, _, mutbl) => {
743 self.push(match mutbl {
744 hir::Mutability::Not => "R",
745 hir::Mutability::Mut => "Q",
746 });
747
748 let pointee_ty =
749 ct_ty.builtin_deref(true).expect("tried to dereference on non-ptr type");
750 let dereferenced_const = ty::Const::new_value(self.tcx, valtree, pointee_ty);
751 dereferenced_const.print(self)?;
752 }
753
754 ty::Array(..) | ty::Tuple(..) | ty::Adt(..) | ty::Slice(_) => {
755 let contents = self.tcx.destructure_const(ct);
756 let fields = contents.fields.iter().copied();
757
758 let print_field_list = |this: &mut Self| {
759 for field in fields.clone() {
760 field.print(this)?;
761 }
762 this.push("E");
763 Ok(())
764 };
765
766 match *ct_ty.kind() {
767 ty::Array(..) | ty::Slice(_) => {
768 self.push("A");
769 print_field_list(self)?;
770 }
771 ty::Tuple(..) => {
772 self.push("T");
773 print_field_list(self)?;
774 }
775 ty::Adt(def, args) => {
776 let variant_idx =
777 contents.variant.expect("destructed const of adt without variant idx");
778 let variant_def = &def.variant(variant_idx);
779
780 self.push("V");
781 self.print_def_path(variant_def.def_id, args)?;
782
783 match variant_def.ctor_kind() {
784 Some(CtorKind::Const) => {
785 self.push("U");
786 }
787 Some(CtorKind::Fn) => {
788 self.push("T");
789 print_field_list(self)?;
790 }
791 None => {
792 self.push("S");
793 for (field_def, field) in iter::zip(&variant_def.fields, fields) {
794 let disambiguated_field =
798 self.tcx.def_key(field_def.did).disambiguated_data;
799 let field_name = disambiguated_field.data.get_opt_name();
800 self.push_disambiguator(
801 disambiguated_field.disambiguator as u64,
802 );
803 self.push_ident(field_name.unwrap().as_str());
804
805 field.print(self)?;
806 }
807 self.push("E");
808 }
809 }
810 }
811 _ => unreachable!(),
812 }
813 }
814 _ => {
815 bug!("symbol_names: unsupported constant of type `{}` ({:?})", ct_ty, ct);
816 }
817 }
818
819 if !ct.has_escaping_bound_vars() {
822 self.consts.insert(ct, start);
823 }
824 Ok(())
825 }
826
827 fn path_crate(&mut self, cnum: CrateNum) -> Result<(), PrintError> {
828 self.push("C");
829 if !self.is_exportable {
830 let stable_crate_id = self.tcx.def_path_hash(cnum.as_def_id()).stable_crate_id();
831 self.push_disambiguator(stable_crate_id.as_u64());
832 }
833 let name = self.tcx.crate_name(cnum);
834 self.push_ident(name.as_str());
835 Ok(())
836 }
837
838 fn path_qualified(
839 &mut self,
840 self_ty: Ty<'tcx>,
841 trait_ref: Option<ty::TraitRef<'tcx>>,
842 ) -> Result<(), PrintError> {
843 assert!(trait_ref.is_some());
844 let trait_ref = trait_ref.unwrap();
845
846 self.push("Y");
847 self_ty.print(self)?;
848 self.print_def_path(trait_ref.def_id, trait_ref.args)
849 }
850
851 fn path_append_impl(
852 &mut self,
853 _: impl FnOnce(&mut Self) -> Result<(), PrintError>,
854 _: &DisambiguatedDefPathData,
855 _: Ty<'tcx>,
856 _: Option<ty::TraitRef<'tcx>>,
857 ) -> Result<(), PrintError> {
858 unreachable!()
860 }
861
862 fn path_append(
863 &mut self,
864 print_prefix: impl FnOnce(&mut Self) -> Result<(), PrintError>,
865 disambiguated_data: &DisambiguatedDefPathData,
866 ) -> Result<(), PrintError> {
867 let ns = match disambiguated_data.data {
868 DefPathData::ForeignMod => return print_prefix(self),
871
872 DefPathData::TypeNs(_) => 't',
874 DefPathData::ValueNs(_) => 'v',
875 DefPathData::Closure => 'C',
876 DefPathData::Ctor => 'c',
877 DefPathData::AnonConst => 'k',
878 DefPathData::OpaqueTy => 'i',
879 DefPathData::SyntheticCoroutineBody => 's',
880 DefPathData::NestedStatic => 'n',
881
882 DefPathData::CrateRoot
884 | DefPathData::Use
885 | DefPathData::GlobalAsm
886 | DefPathData::Impl
887 | DefPathData::MacroNs(_)
888 | DefPathData::LifetimeNs(_)
889 | DefPathData::OpaqueLifetime(_)
890 | DefPathData::AnonAssocTy(..) => {
891 bug!("symbol_names: unexpected DefPathData: {:?}", disambiguated_data.data)
892 }
893 };
894
895 let name = disambiguated_data.data.get_opt_name();
896
897 self.path_append_ns(
898 print_prefix,
899 ns,
900 disambiguated_data.disambiguator as u64,
901 name.unwrap_or(sym::empty).as_str(),
902 )
903 }
904
905 fn path_generic_args(
906 &mut self,
907 print_prefix: impl FnOnce(&mut Self) -> Result<(), PrintError>,
908 args: &[GenericArg<'tcx>],
909 ) -> Result<(), PrintError> {
910 let print_regions = args.iter().any(|arg| match arg.kind() {
912 GenericArgKind::Lifetime(r) => !r.is_erased(),
913 _ => false,
914 });
915 let args = args.iter().cloned().filter(|arg| match arg.kind() {
916 GenericArgKind::Lifetime(_) => print_regions,
917 _ => true,
918 });
919
920 if args.clone().next().is_none() {
921 return print_prefix(self);
922 }
923
924 self.push("I");
925 print_prefix(self)?;
926 for arg in args {
927 match arg.kind() {
928 GenericArgKind::Lifetime(lt) => {
929 lt.print(self)?;
930 }
931 GenericArgKind::Type(ty) => {
932 ty.print(self)?;
933 }
934 GenericArgKind::Const(c) => {
935 self.push("K");
936 c.print(self)?;
937 }
938 }
939 }
940 self.push("E");
941
942 Ok(())
943 }
944}
945pub(crate) fn push_integer_62(x: u64, output: &mut String) {
951 if let Some(x) = x.checked_sub(1) {
952 output.push_str(&x.to_base(62));
953 }
954 output.push('_');
955}
956
957pub(crate) fn encode_integer_62(x: u64) -> String {
958 let mut output = String::new();
959 push_integer_62(x, &mut output);
960 output
961}
962
963pub(crate) fn push_ident(ident: &str, output: &mut String) {
964 let mut use_punycode = false;
965 for b in ident.bytes() {
966 match b {
967 b'_' | b'a'..=b'z' | b'A'..=b'Z' | b'0'..=b'9' => {}
968 0x80..=0xff => use_punycode = true,
969 _ => bug!("symbol_names: bad byte {} in ident {:?}", b, ident),
970 }
971 }
972
973 let punycode_string;
974 let ident = if use_punycode {
975 output.push('u');
976
977 let mut punycode_bytes = match punycode::encode(ident) {
979 Ok(s) => s.into_bytes(),
980 Err(()) => bug!("symbol_names: punycode encoding failed for ident {:?}", ident),
981 };
982
983 if let Some(c) = punycode_bytes.iter_mut().rfind(|&&mut c| c == b'-') {
985 *c = b'_';
986 }
987
988 punycode_string = String::from_utf8(punycode_bytes).unwrap();
990 &punycode_string
991 } else {
992 ident
993 };
994
995 let _ = write!(output, "{}", ident.len());
996
997 if let Some('_' | '0'..='9') = ident.chars().next() {
999 output.push('_');
1000 }
1001
1002 output.push_str(ident);
1003}