| use std::fmt::Write; |
| use std::iter; |
| use std::ops::Range; |
| |
| use rustc_abi::Integer; |
| use rustc_data_structures::base_n::ToBaseN; |
| use rustc_data_structures::fx::FxHashMap; |
| use rustc_data_structures::intern::Interned; |
| use rustc_hir as hir; |
| use rustc_hir::def::CtorKind; |
| use rustc_hir::def_id::{CrateNum, DefId}; |
| use rustc_hir::definitions::{DefPathData, DisambiguatedDefPathData}; |
| use rustc_middle::bug; |
| use rustc_middle::ty::layout::IntegerExt; |
| use rustc_middle::ty::print::{Print, PrintError, Printer}; |
| use rustc_middle::ty::{ |
| self, EarlyBinder, FloatTy, GenericArg, GenericArgKind, Instance, IntTy, ReifyReason, Ty, |
| TyCtxt, TypeVisitable, TypeVisitableExt, UintTy, |
| }; |
| use rustc_span::symbol::kw; |
| use rustc_target::spec::abi::Abi; |
| |
| pub(super) fn mangle<'tcx>( |
| tcx: TyCtxt<'tcx>, |
| instance: Instance<'tcx>, |
| instantiating_crate: Option<CrateNum>, |
| ) -> String { |
| let def_id = instance.def_id(); |
| // FIXME(eddyb) this should ideally not be needed. |
| let args = tcx.normalize_erasing_regions(ty::ParamEnv::reveal_all(), instance.args); |
| |
| let prefix = "_R"; |
| let mut cx: SymbolMangler<'_> = SymbolMangler { |
| tcx, |
| start_offset: prefix.len(), |
| paths: FxHashMap::default(), |
| types: FxHashMap::default(), |
| consts: FxHashMap::default(), |
| binders: vec![], |
| out: String::from(prefix), |
| }; |
| |
| // Append `::{shim:...#0}` to shims that can coexist with a non-shim instance. |
| let shim_kind = match instance.def { |
| ty::InstanceKind::ThreadLocalShim(_) => Some("tls"), |
| ty::InstanceKind::VTableShim(_) => Some("vtable"), |
| ty::InstanceKind::ReifyShim(_, None) => Some("reify"), |
| ty::InstanceKind::ReifyShim(_, Some(ReifyReason::FnPtr)) => Some("reify_fnptr"), |
| ty::InstanceKind::ReifyShim(_, Some(ReifyReason::Vtable)) => Some("reify_vtable"), |
| |
| // FIXME(async_closures): This shouldn't be needed when we fix |
| // `Instance::ty`/`Instance::def_id`. |
| ty::InstanceKind::ConstructCoroutineInClosureShim { receiver_by_ref: true, .. } => { |
| Some("by_move") |
| } |
| ty::InstanceKind::ConstructCoroutineInClosureShim { receiver_by_ref: false, .. } => { |
| Some("by_ref") |
| } |
| |
| _ => None, |
| }; |
| |
| if let Some(shim_kind) = shim_kind { |
| cx.path_append_ns(|cx| cx.print_def_path(def_id, args), 'S', 0, shim_kind).unwrap() |
| } else { |
| cx.print_def_path(def_id, args).unwrap() |
| }; |
| if let Some(instantiating_crate) = instantiating_crate { |
| cx.print_def_path(instantiating_crate.as_def_id(), &[]).unwrap(); |
| } |
| std::mem::take(&mut cx.out) |
| } |
| |
| pub(super) fn mangle_typeid_for_trait_ref<'tcx>( |
| tcx: TyCtxt<'tcx>, |
| trait_ref: ty::PolyExistentialTraitRef<'tcx>, |
| ) -> String { |
| // FIXME(flip1995): See comment in `mangle_typeid_for_fnabi`. |
| let mut cx = SymbolMangler { |
| tcx, |
| start_offset: 0, |
| paths: FxHashMap::default(), |
| types: FxHashMap::default(), |
| consts: FxHashMap::default(), |
| binders: vec![], |
| out: String::new(), |
| }; |
| cx.print_def_path(trait_ref.def_id(), &[]).unwrap(); |
| std::mem::take(&mut cx.out) |
| } |
| |
| struct BinderLevel { |
| /// The range of distances from the root of what's |
| /// being printed, to the lifetimes in a binder. |
| /// Specifically, a `BrAnon` lifetime has depth |
| /// `lifetime_depths.start + index`, going away from the |
| /// the root and towards its use site, as the var index increases. |
| /// This is used to flatten rustc's pairing of `BrAnon` |
| /// (intra-binder disambiguation) with a `DebruijnIndex` |
| /// (binder addressing), to "true" de Bruijn indices, |
| /// by subtracting the depth of a certain lifetime, from |
| /// the innermost depth at its use site. |
| lifetime_depths: Range<u32>, |
| } |
| |
| struct SymbolMangler<'tcx> { |
| tcx: TyCtxt<'tcx>, |
| binders: Vec<BinderLevel>, |
| out: String, |
| |
| /// The length of the prefix in `out` (e.g. 2 for `_R`). |
| start_offset: usize, |
| /// The values are start positions in `out`, in bytes. |
| paths: FxHashMap<(DefId, &'tcx [GenericArg<'tcx>]), usize>, |
| types: FxHashMap<Ty<'tcx>, usize>, |
| consts: FxHashMap<ty::Const<'tcx>, usize>, |
| } |
| |
| impl<'tcx> SymbolMangler<'tcx> { |
| fn push(&mut self, s: &str) { |
| self.out.push_str(s); |
| } |
| |
| /// Push a `_`-terminated base 62 integer, using the format |
| /// specified in the RFC as `<base-62-number>`, that is: |
| /// * `x = 0` is encoded as just the `"_"` terminator |
| /// * `x > 0` is encoded as `x - 1` in base 62, followed by `"_"`, |
| /// e.g. `1` becomes `"0_"`, `62` becomes `"Z_"`, etc. |
| fn push_integer_62(&mut self, x: u64) { |
| push_integer_62(x, &mut self.out) |
| } |
| |
| /// Push a `tag`-prefixed base 62 integer, when larger than `0`, that is: |
| /// * `x = 0` is encoded as `""` (nothing) |
| /// * `x > 0` is encoded as the `tag` followed by `push_integer_62(x - 1)` |
| /// e.g. `1` becomes `tag + "_"`, `2` becomes `tag + "0_"`, etc. |
| fn push_opt_integer_62(&mut self, tag: &str, x: u64) { |
| if let Some(x) = x.checked_sub(1) { |
| self.push(tag); |
| self.push_integer_62(x); |
| } |
| } |
| |
| fn push_disambiguator(&mut self, dis: u64) { |
| self.push_opt_integer_62("s", dis); |
| } |
| |
| fn push_ident(&mut self, ident: &str) { |
| push_ident(ident, &mut self.out) |
| } |
| |
| fn path_append_ns( |
| &mut self, |
| print_prefix: impl FnOnce(&mut Self) -> Result<(), PrintError>, |
| ns: char, |
| disambiguator: u64, |
| name: &str, |
| ) -> Result<(), PrintError> { |
| self.push("N"); |
| self.out.push(ns); |
| print_prefix(self)?; |
| self.push_disambiguator(disambiguator); |
| self.push_ident(name); |
| Ok(()) |
| } |
| |
| fn print_backref(&mut self, i: usize) -> Result<(), PrintError> { |
| self.push("B"); |
| self.push_integer_62((i - self.start_offset) as u64); |
| Ok(()) |
| } |
| |
| fn in_binder<T>( |
| &mut self, |
| value: &ty::Binder<'tcx, T>, |
| print_value: impl FnOnce(&mut Self, &T) -> Result<(), PrintError>, |
| ) -> Result<(), PrintError> |
| where |
| T: TypeVisitable<TyCtxt<'tcx>>, |
| { |
| let mut lifetime_depths = |
| self.binders.last().map(|b| b.lifetime_depths.end).map_or(0..0, |i| i..i); |
| |
| // FIXME(non-lifetime-binders): What to do here? |
| let lifetimes = value |
| .bound_vars() |
| .iter() |
| .filter(|var| matches!(var, ty::BoundVariableKind::Region(..))) |
| .count() as u32; |
| |
| self.push_opt_integer_62("G", lifetimes as u64); |
| lifetime_depths.end += lifetimes; |
| |
| self.binders.push(BinderLevel { lifetime_depths }); |
| print_value(self, value.as_ref().skip_binder())?; |
| self.binders.pop(); |
| |
| Ok(()) |
| } |
| } |
| |
| impl<'tcx> Printer<'tcx> for SymbolMangler<'tcx> { |
| fn tcx(&self) -> TyCtxt<'tcx> { |
| self.tcx |
| } |
| |
| fn print_def_path( |
| &mut self, |
| def_id: DefId, |
| args: &'tcx [GenericArg<'tcx>], |
| ) -> Result<(), PrintError> { |
| if let Some(&i) = self.paths.get(&(def_id, args)) { |
| return self.print_backref(i); |
| } |
| let start = self.out.len(); |
| |
| self.default_print_def_path(def_id, args)?; |
| |
| // Only cache paths that do not refer to an enclosing |
| // binder (which would change depending on context). |
| if !args.iter().any(|k| k.has_escaping_bound_vars()) { |
| self.paths.insert((def_id, args), start); |
| } |
| Ok(()) |
| } |
| |
| fn print_impl_path( |
| &mut self, |
| impl_def_id: DefId, |
| args: &'tcx [GenericArg<'tcx>], |
| mut self_ty: Ty<'tcx>, |
| mut impl_trait_ref: Option<ty::TraitRef<'tcx>>, |
| ) -> Result<(), PrintError> { |
| let key = self.tcx.def_key(impl_def_id); |
| let parent_def_id = DefId { index: key.parent.unwrap(), ..impl_def_id }; |
| |
| let mut param_env = self.tcx.param_env_reveal_all_normalized(impl_def_id); |
| if !args.is_empty() { |
| param_env = EarlyBinder::bind(param_env).instantiate(self.tcx, args); |
| } |
| |
| match &mut impl_trait_ref { |
| Some(impl_trait_ref) => { |
| assert_eq!(impl_trait_ref.self_ty(), self_ty); |
| *impl_trait_ref = self.tcx.normalize_erasing_regions(param_env, *impl_trait_ref); |
| self_ty = impl_trait_ref.self_ty(); |
| } |
| None => { |
| self_ty = self.tcx.normalize_erasing_regions(param_env, self_ty); |
| } |
| } |
| |
| self.push(match impl_trait_ref { |
| Some(_) => "X", |
| None => "M", |
| }); |
| |
| // Encode impl generic params if the generic parameters contain non-region parameters |
| // (implying polymorphization is enabled) and this isn't an inherent impl. |
| if impl_trait_ref.is_some() && args.iter().any(|a| a.has_non_region_param()) { |
| self.path_generic_args( |
| |this| { |
| this.path_append_ns( |
| |cx| cx.print_def_path(parent_def_id, &[]), |
| 'I', |
| key.disambiguated_data.disambiguator as u64, |
| "", |
| ) |
| }, |
| args, |
| )?; |
| } else { |
| self.push_disambiguator(key.disambiguated_data.disambiguator as u64); |
| self.print_def_path(parent_def_id, &[])?; |
| } |
| |
| self_ty.print(self)?; |
| |
| if let Some(trait_ref) = impl_trait_ref { |
| self.print_def_path(trait_ref.def_id, trait_ref.args)?; |
| } |
| |
| Ok(()) |
| } |
| |
| fn print_region(&mut self, region: ty::Region<'_>) -> Result<(), PrintError> { |
| let i = match *region { |
| // Erased lifetimes use the index 0, for a |
| // shorter mangling of `L_`. |
| ty::ReErased => 0, |
| |
| // Bound lifetimes use indices starting at 1, |
| // see `BinderLevel` for more details. |
| ty::ReBound(debruijn, ty::BoundRegion { var, kind: ty::BrAnon }) => { |
| let binder = &self.binders[self.binders.len() - 1 - debruijn.index()]; |
| let depth = binder.lifetime_depths.start + var.as_u32(); |
| |
| 1 + (self.binders.last().unwrap().lifetime_depths.end - 1 - depth) |
| } |
| |
| _ => bug!("symbol_names: non-erased region `{:?}`", region), |
| }; |
| self.push("L"); |
| self.push_integer_62(i as u64); |
| Ok(()) |
| } |
| |
| fn print_type(&mut self, ty: Ty<'tcx>) -> Result<(), PrintError> { |
| // Basic types, never cached (single-character). |
| let basic_type = match ty.kind() { |
| ty::Bool => "b", |
| ty::Char => "c", |
| ty::Str => "e", |
| ty::Tuple(_) if ty.is_unit() => "u", |
| ty::Int(IntTy::I8) => "a", |
| ty::Int(IntTy::I16) => "s", |
| ty::Int(IntTy::I32) => "l", |
| ty::Int(IntTy::I64) => "x", |
| ty::Int(IntTy::I128) => "n", |
| ty::Int(IntTy::Isize) => "i", |
| ty::Uint(UintTy::U8) => "h", |
| ty::Uint(UintTy::U16) => "t", |
| ty::Uint(UintTy::U32) => "m", |
| ty::Uint(UintTy::U64) => "y", |
| ty::Uint(UintTy::U128) => "o", |
| ty::Uint(UintTy::Usize) => "j", |
| ty::Float(FloatTy::F16) => "C3f16", |
| ty::Float(FloatTy::F32) => "f", |
| ty::Float(FloatTy::F64) => "d", |
| ty::Float(FloatTy::F128) => "C4f128", |
| ty::Never => "z", |
| |
| // Should only be encountered with polymorphization, |
| // or within the identity-substituted impl header of an |
| // item nested within an impl item. |
| ty::Param(_) => "p", |
| |
| ty::Bound(..) | ty::Placeholder(_) | ty::Infer(_) | ty::Error(_) => bug!(), |
| |
| _ => "", |
| }; |
| if !basic_type.is_empty() { |
| self.push(basic_type); |
| return Ok(()); |
| } |
| |
| if let Some(&i) = self.types.get(&ty) { |
| return self.print_backref(i); |
| } |
| let start = self.out.len(); |
| |
| match *ty.kind() { |
| // Basic types, handled above. |
| ty::Bool | ty::Char | ty::Str | ty::Int(_) | ty::Uint(_) | ty::Float(_) | ty::Never => { |
| unreachable!() |
| } |
| ty::Tuple(_) if ty.is_unit() => unreachable!(), |
| |
| // Placeholders, also handled as part of basic types. |
| ty::Param(_) | ty::Bound(..) | ty::Placeholder(_) | ty::Infer(_) | ty::Error(_) => { |
| unreachable!() |
| } |
| |
| ty::Ref(r, ty, mutbl) => { |
| self.push(match mutbl { |
| hir::Mutability::Not => "R", |
| hir::Mutability::Mut => "Q", |
| }); |
| if !r.is_erased() { |
| r.print(self)?; |
| } |
| ty.print(self)?; |
| } |
| |
| ty::RawPtr(ty, mutbl) => { |
| self.push(match mutbl { |
| hir::Mutability::Not => "P", |
| hir::Mutability::Mut => "O", |
| }); |
| ty.print(self)?; |
| } |
| |
| ty::Pat(ty, pat) => match *pat { |
| ty::PatternKind::Range { start, end, include_end } => { |
| let consts = [ |
| start.unwrap_or(self.tcx.consts.unit), |
| end.unwrap_or(self.tcx.consts.unit), |
| ty::Const::from_bool(self.tcx, include_end), |
| ]; |
| // HACK: Represent as tuple until we have something better. |
| // HACK: constants are used in arrays, even if the types don't match. |
| self.push("T"); |
| ty.print(self)?; |
| for ct in consts { |
| Ty::new_array_with_const_len(self.tcx, self.tcx.types.unit, ct) |
| .print(self)?; |
| } |
| self.push("E"); |
| } |
| }, |
| |
| ty::Array(ty, len) => { |
| self.push("A"); |
| ty.print(self)?; |
| self.print_const(len)?; |
| } |
| ty::Slice(ty) => { |
| self.push("S"); |
| ty.print(self)?; |
| } |
| |
| ty::Tuple(tys) => { |
| self.push("T"); |
| for ty in tys.iter() { |
| ty.print(self)?; |
| } |
| self.push("E"); |
| } |
| |
| // Mangle all nominal types as paths. |
| ty::Adt(ty::AdtDef(Interned(&ty::AdtDefData { did: def_id, .. }, _)), args) |
| | ty::FnDef(def_id, args) |
| | ty::Closure(def_id, args) |
| | ty::CoroutineClosure(def_id, args) |
| | ty::Coroutine(def_id, args) => { |
| self.print_def_path(def_id, args)?; |
| } |
| |
| // We may still encounter projections here due to the printing |
| // logic sometimes passing identity-substituted impl headers. |
| ty::Alias(ty::Projection, ty::AliasTy { def_id, args, .. }) => { |
| self.print_def_path(def_id, args)?; |
| } |
| |
| ty::Foreign(def_id) => { |
| self.print_def_path(def_id, &[])?; |
| } |
| |
| ty::FnPtr(sig_tys, hdr) => { |
| let sig = sig_tys.with(hdr); |
| self.push("F"); |
| self.in_binder(&sig, |cx, sig| { |
| if sig.safety == hir::Safety::Unsafe { |
| cx.push("U"); |
| } |
| match sig.abi { |
| Abi::Rust => {} |
| Abi::C { unwind: false } => cx.push("KC"), |
| abi => { |
| cx.push("K"); |
| let name = abi.name(); |
| if name.contains('-') { |
| cx.push_ident(&name.replace('-', "_")); |
| } else { |
| cx.push_ident(name); |
| } |
| } |
| } |
| for &ty in sig.inputs() { |
| ty.print(cx)?; |
| } |
| if sig.c_variadic { |
| cx.push("v"); |
| } |
| cx.push("E"); |
| sig.output().print(cx) |
| })?; |
| } |
| |
| ty::Dynamic(predicates, r, kind) => { |
| self.push(match kind { |
| ty::Dyn => "D", |
| // FIXME(dyn-star): need to update v0 mangling docs |
| ty::DynStar => "D*", |
| }); |
| self.print_dyn_existential(predicates)?; |
| r.print(self)?; |
| } |
| |
| ty::Alias(..) => bug!("symbol_names: unexpected alias"), |
| ty::CoroutineWitness(..) => bug!("symbol_names: unexpected `CoroutineWitness`"), |
| } |
| |
| // Only cache types that do not refer to an enclosing |
| // binder (which would change depending on context). |
| if !ty.has_escaping_bound_vars() { |
| self.types.insert(ty, start); |
| } |
| Ok(()) |
| } |
| |
| fn print_dyn_existential( |
| &mut self, |
| predicates: &'tcx ty::List<ty::PolyExistentialPredicate<'tcx>>, |
| ) -> Result<(), PrintError> { |
| // Okay, so this is a bit tricky. Imagine we have a trait object like |
| // `dyn for<'a> Foo<'a, Bar = &'a ()>`. When we mangle this, the |
| // output looks really close to the syntax, where the `Bar = &'a ()` bit |
| // is under the same binders (`['a]`) as the `Foo<'a>` bit. However, we |
| // actually desugar these into two separate `ExistentialPredicate`s. We |
| // can't enter/exit the "binder scope" twice though, because then we |
| // would mangle the binders twice. (Also, side note, we merging these |
| // two is kind of difficult, because of potential HRTBs in the Projection |
| // predicate.) |
| // |
| // Also worth mentioning: imagine that we instead had |
| // `dyn for<'a> Foo<'a, Bar = &'a ()> + Send`. In this case, `Send` is |
| // under the same binders as `Foo`. Currently, this doesn't matter, |
| // because only *auto traits* are allowed other than the principal trait |
| // and all auto traits don't have any generics. Two things could |
| // make this not an "okay" mangling: |
| // 1) Instead of mangling only *used* |
| // bound vars, we want to mangle *all* bound vars (`for<'b> Send` is a |
| // valid trait predicate); |
| // 2) We allow multiple "principal" traits in the future, or at least |
| // allow in any form another trait predicate that can take generics. |
| // |
| // Here we assume that predicates have the following structure: |
| // [<Trait> [{<Projection>}]] [{<Auto>}] |
| // Since any predicates after the first one shouldn't change the binders, |
| // just put them all in the binders of the first. |
| self.in_binder(&predicates[0], |cx, _| { |
| for predicate in predicates.iter() { |
| // It would be nice to be able to validate bound vars here, but |
| // projections can actually include bound vars from super traits |
| // because of HRTBs (only in the `Self` type). Also, auto traits |
| // could have different bound vars *anyways*. |
| match predicate.as_ref().skip_binder() { |
| ty::ExistentialPredicate::Trait(trait_ref) => { |
| // Use a type that can't appear in defaults of type parameters. |
| let dummy_self = Ty::new_fresh(cx.tcx, 0); |
| let trait_ref = trait_ref.with_self_ty(cx.tcx, dummy_self); |
| cx.print_def_path(trait_ref.def_id, trait_ref.args)?; |
| } |
| ty::ExistentialPredicate::Projection(projection) => { |
| let name = cx.tcx.associated_item(projection.def_id).name; |
| cx.push("p"); |
| cx.push_ident(name.as_str()); |
| match projection.term.unpack() { |
| ty::TermKind::Ty(ty) => ty.print(cx), |
| ty::TermKind::Const(c) => c.print(cx), |
| }?; |
| } |
| ty::ExistentialPredicate::AutoTrait(def_id) => { |
| cx.print_def_path(*def_id, &[])?; |
| } |
| } |
| } |
| Ok(()) |
| })?; |
| |
| self.push("E"); |
| Ok(()) |
| } |
| |
| fn print_const(&mut self, ct: ty::Const<'tcx>) -> Result<(), PrintError> { |
| // We only mangle a typed value if the const can be evaluated. |
| let (ct_ty, valtree) = match ct.kind() { |
| ty::ConstKind::Value(ty, val) => (ty, val), |
| |
| // Should only be encountered with polymorphization, |
| // or within the identity-substituted impl header of an |
| // item nested within an impl item. |
| ty::ConstKind::Param(_) => { |
| // Never cached (single-character). |
| self.push("p"); |
| return Ok(()); |
| } |
| |
| // We may still encounter unevaluated consts due to the printing |
| // logic sometimes passing identity-substituted impl headers. |
| ty::Unevaluated(ty::UnevaluatedConst { def, args, .. }) => { |
| return self.print_def_path(def, args); |
| } |
| |
| ty::ConstKind::Expr(_) |
| | ty::ConstKind::Infer(_) |
| | ty::ConstKind::Bound(..) |
| | ty::ConstKind::Placeholder(_) |
| | ty::ConstKind::Error(_) => bug!(), |
| }; |
| |
| if let Some(&i) = self.consts.get(&ct) { |
| self.print_backref(i)?; |
| return Ok(()); |
| } |
| |
| let start = self.out.len(); |
| |
| match ct_ty.kind() { |
| ty::Uint(_) | ty::Int(_) | ty::Bool | ty::Char => { |
| ct_ty.print(self)?; |
| |
| let mut bits = ct |
| .try_to_bits(self.tcx, ty::ParamEnv::reveal_all()) |
| .expect("expected const to be monomorphic"); |
| |
| // Negative integer values are mangled using `n` as a "sign prefix". |
| if let ty::Int(ity) = ct_ty.kind() { |
| let val = |
| Integer::from_int_ty(&self.tcx, *ity).size().sign_extend(bits) as i128; |
| if val < 0 { |
| self.push("n"); |
| } |
| bits = val.unsigned_abs(); |
| } |
| |
| let _ = write!(self.out, "{bits:x}_"); |
| } |
| |
| // Handle `str` as partial support for unsized constants |
| ty::Str => { |
| let tcx = self.tcx(); |
| // HACK(jaic1): hide the `str` type behind a reference |
| // for the following transformation from valtree to raw bytes |
| let ref_ty = Ty::new_imm_ref(tcx, tcx.lifetimes.re_static, ct_ty); |
| let slice = valtree.try_to_raw_bytes(tcx, ref_ty).unwrap_or_else(|| { |
| bug!("expected to get raw bytes from valtree {:?} for type {:}", valtree, ct_ty) |
| }); |
| let s = std::str::from_utf8(slice).expect("non utf8 str from MIR interpreter"); |
| |
| // "e" for str as a basic type |
| self.push("e"); |
| |
| // FIXME(eddyb) use a specialized hex-encoding loop. |
| for byte in s.bytes() { |
| let _ = write!(self.out, "{byte:02x}"); |
| } |
| |
| self.push("_"); |
| } |
| |
| // FIXME(valtrees): Remove the special case for `str` |
| // here and fully support unsized constants. |
| ty::Ref(_, _, mutbl) => { |
| self.push(match mutbl { |
| hir::Mutability::Not => "R", |
| hir::Mutability::Mut => "Q", |
| }); |
| |
| let pointee_ty = |
| ct_ty.builtin_deref(true).expect("tried to dereference on non-ptr type"); |
| let dereferenced_const = ty::Const::new_value(self.tcx, valtree, pointee_ty); |
| dereferenced_const.print(self)?; |
| } |
| |
| ty::Array(..) | ty::Tuple(..) | ty::Adt(..) | ty::Slice(_) => { |
| let contents = self.tcx.destructure_const(ct); |
| let fields = contents.fields.iter().copied(); |
| |
| let print_field_list = |this: &mut Self| { |
| for field in fields.clone() { |
| field.print(this)?; |
| } |
| this.push("E"); |
| Ok(()) |
| }; |
| |
| match *ct_ty.kind() { |
| ty::Array(..) | ty::Slice(_) => { |
| self.push("A"); |
| print_field_list(self)?; |
| } |
| ty::Tuple(..) => { |
| self.push("T"); |
| print_field_list(self)?; |
| } |
| ty::Adt(def, args) => { |
| let variant_idx = |
| contents.variant.expect("destructed const of adt without variant idx"); |
| let variant_def = &def.variant(variant_idx); |
| |
| self.push("V"); |
| self.print_def_path(variant_def.def_id, args)?; |
| |
| match variant_def.ctor_kind() { |
| Some(CtorKind::Const) => { |
| self.push("U"); |
| } |
| Some(CtorKind::Fn) => { |
| self.push("T"); |
| print_field_list(self)?; |
| } |
| None => { |
| self.push("S"); |
| for (field_def, field) in iter::zip(&variant_def.fields, fields) { |
| // HACK(eddyb) this mimics `path_append`, |
| // instead of simply using `field_def.ident`, |
| // just to be able to handle disambiguators. |
| let disambiguated_field = |
| self.tcx.def_key(field_def.did).disambiguated_data; |
| let field_name = disambiguated_field.data.get_opt_name(); |
| self.push_disambiguator( |
| disambiguated_field.disambiguator as u64, |
| ); |
| self.push_ident(field_name.unwrap_or(kw::Empty).as_str()); |
| |
| field.print(self)?; |
| } |
| self.push("E"); |
| } |
| } |
| } |
| _ => unreachable!(), |
| } |
| } |
| _ => { |
| bug!("symbol_names: unsupported constant of type `{}` ({:?})", ct_ty, ct); |
| } |
| } |
| |
| // Only cache consts that do not refer to an enclosing |
| // binder (which would change depending on context). |
| if !ct.has_escaping_bound_vars() { |
| self.consts.insert(ct, start); |
| } |
| Ok(()) |
| } |
| |
| fn path_crate(&mut self, cnum: CrateNum) -> Result<(), PrintError> { |
| self.push("C"); |
| let stable_crate_id = self.tcx.def_path_hash(cnum.as_def_id()).stable_crate_id(); |
| self.push_disambiguator(stable_crate_id.as_u64()); |
| let name = self.tcx.crate_name(cnum); |
| self.push_ident(name.as_str()); |
| Ok(()) |
| } |
| |
| fn path_qualified( |
| &mut self, |
| self_ty: Ty<'tcx>, |
| trait_ref: Option<ty::TraitRef<'tcx>>, |
| ) -> Result<(), PrintError> { |
| assert!(trait_ref.is_some()); |
| let trait_ref = trait_ref.unwrap(); |
| |
| self.push("Y"); |
| self_ty.print(self)?; |
| self.print_def_path(trait_ref.def_id, trait_ref.args) |
| } |
| |
| fn path_append_impl( |
| &mut self, |
| _: impl FnOnce(&mut Self) -> Result<(), PrintError>, |
| _: &DisambiguatedDefPathData, |
| _: Ty<'tcx>, |
| _: Option<ty::TraitRef<'tcx>>, |
| ) -> Result<(), PrintError> { |
| // Inlined into `print_impl_path` |
| unreachable!() |
| } |
| |
| fn path_append( |
| &mut self, |
| print_prefix: impl FnOnce(&mut Self) -> Result<(), PrintError>, |
| disambiguated_data: &DisambiguatedDefPathData, |
| ) -> Result<(), PrintError> { |
| let ns = match disambiguated_data.data { |
| // Extern block segments can be skipped, names from extern blocks |
| // are effectively living in their parent modules. |
| DefPathData::ForeignMod => return print_prefix(self), |
| |
| // Uppercase categories are more stable than lowercase ones. |
| DefPathData::TypeNs(_) => 't', |
| DefPathData::ValueNs(_) => 'v', |
| DefPathData::Closure => 'C', |
| DefPathData::Ctor => 'c', |
| DefPathData::AnonConst => 'k', |
| DefPathData::OpaqueTy => 'i', |
| |
| // These should never show up as `path_append` arguments. |
| DefPathData::CrateRoot |
| | DefPathData::Use |
| | DefPathData::GlobalAsm |
| | DefPathData::Impl |
| | DefPathData::MacroNs(_) |
| | DefPathData::LifetimeNs(_) |
| | DefPathData::AnonAdt => { |
| bug!("symbol_names: unexpected DefPathData: {:?}", disambiguated_data.data) |
| } |
| }; |
| |
| let name = disambiguated_data.data.get_opt_name(); |
| |
| self.path_append_ns( |
| print_prefix, |
| ns, |
| disambiguated_data.disambiguator as u64, |
| name.unwrap_or(kw::Empty).as_str(), |
| ) |
| } |
| |
| fn path_generic_args( |
| &mut self, |
| print_prefix: impl FnOnce(&mut Self) -> Result<(), PrintError>, |
| args: &[GenericArg<'tcx>], |
| ) -> Result<(), PrintError> { |
| // Don't print any regions if they're all erased. |
| let print_regions = args.iter().any(|arg| match arg.unpack() { |
| GenericArgKind::Lifetime(r) => !r.is_erased(), |
| _ => false, |
| }); |
| let args = args.iter().cloned().filter(|arg| match arg.unpack() { |
| GenericArgKind::Lifetime(_) => print_regions, |
| _ => true, |
| }); |
| |
| if args.clone().next().is_none() { |
| return print_prefix(self); |
| } |
| |
| self.push("I"); |
| print_prefix(self)?; |
| for arg in args { |
| match arg.unpack() { |
| GenericArgKind::Lifetime(lt) => { |
| lt.print(self)?; |
| } |
| GenericArgKind::Type(ty) => { |
| ty.print(self)?; |
| } |
| GenericArgKind::Const(c) => { |
| self.push("K"); |
| c.print(self)?; |
| } |
| } |
| } |
| self.push("E"); |
| |
| Ok(()) |
| } |
| } |
| /// Push a `_`-terminated base 62 integer, using the format |
| /// specified in the RFC as `<base-62-number>`, that is: |
| /// * `x = 0` is encoded as just the `"_"` terminator |
| /// * `x > 0` is encoded as `x - 1` in base 62, followed by `"_"`, |
| /// e.g. `1` becomes `"0_"`, `62` becomes `"Z_"`, etc. |
| pub(crate) fn push_integer_62(x: u64, output: &mut String) { |
| if let Some(x) = x.checked_sub(1) { |
| output.push_str(&x.to_base(62)); |
| } |
| output.push('_'); |
| } |
| |
| pub(crate) fn encode_integer_62(x: u64) -> String { |
| let mut output = String::new(); |
| push_integer_62(x, &mut output); |
| output |
| } |
| |
| pub(crate) fn push_ident(ident: &str, output: &mut String) { |
| let mut use_punycode = false; |
| for b in ident.bytes() { |
| match b { |
| b'_' | b'a'..=b'z' | b'A'..=b'Z' | b'0'..=b'9' => {} |
| 0x80..=0xff => use_punycode = true, |
| _ => bug!("symbol_names: bad byte {} in ident {:?}", b, ident), |
| } |
| } |
| |
| let punycode_string; |
| let ident = if use_punycode { |
| output.push('u'); |
| |
| // FIXME(eddyb) we should probably roll our own punycode implementation. |
| let mut punycode_bytes = match punycode::encode(ident) { |
| Ok(s) => s.into_bytes(), |
| Err(()) => bug!("symbol_names: punycode encoding failed for ident {:?}", ident), |
| }; |
| |
| // Replace `-` with `_`. |
| if let Some(c) = punycode_bytes.iter_mut().rfind(|&&mut c| c == b'-') { |
| *c = b'_'; |
| } |
| |
| // FIXME(eddyb) avoid rechecking UTF-8 validity. |
| punycode_string = String::from_utf8(punycode_bytes).unwrap(); |
| &punycode_string |
| } else { |
| ident |
| }; |
| |
| let _ = write!(output, "{}", ident.len()); |
| |
| // Write a separating `_` if necessary (leading digit or `_`). |
| if let Some('_' | '0'..='9') = ident.chars().next() { |
| output.push('_'); |
| } |
| |
| output.push_str(ident); |
| } |
