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-rw-r--r--compiler/rustc_symbol_mangling/src/v0.rs844
1 files changed, 844 insertions, 0 deletions
diff --git a/compiler/rustc_symbol_mangling/src/v0.rs b/compiler/rustc_symbol_mangling/src/v0.rs
new file mode 100644
index 000000000..71fa5a448
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+++ b/compiler/rustc_symbol_mangling/src/v0.rs
@@ -0,0 +1,844 @@
+use rustc_data_structures::base_n;
+use rustc_data_structures::fx::{FxHashMap, FxHashSet};
+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::ty::layout::IntegerExt;
+use rustc_middle::ty::print::{Print, Printer};
+use rustc_middle::ty::subst::{GenericArg, GenericArgKind, Subst};
+use rustc_middle::ty::{
+ self, EarlyBinder, FloatTy, Instance, IntTy, Ty, TyCtxt, TypeVisitable, UintTy,
+};
+use rustc_span::symbol::kw;
+use rustc_target::abi::Integer;
+use rustc_target::spec::abi::Abi;
+
+use std::fmt::Write;
+use std::iter;
+use std::ops::Range;
+
+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 substs = tcx.normalize_erasing_regions(ty::ParamEnv::reveal_all(), instance.substs);
+
+ let prefix = "_R";
+ let mut cx = &mut 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::InstanceDef::VTableShim(_) => Some("vtable"),
+ ty::InstanceDef::ReifyShim(_) => Some("reify"),
+
+ _ => None,
+ };
+
+ cx = if let Some(shim_kind) = shim_kind {
+ cx.path_append_ns(|cx| cx.print_def_path(def_id, substs), 'S', 0, shim_kind).unwrap()
+ } else {
+ cx.print_def_path(def_id, substs).unwrap()
+ };
+ if let Some(instantiating_crate) = instantiating_crate {
+ cx = 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 = &mut SymbolMangler {
+ tcx,
+ start_offset: 0,
+ paths: FxHashMap::default(),
+ types: FxHashMap::default(),
+ consts: FxHashMap::default(),
+ binders: vec![],
+ out: String::new(),
+ };
+ cx = 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(i)` lifetime has depth
+ /// `lifetime_depths.start + i`, going away from the
+ /// the root and towards its use site, as `i` 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) {
+ if let Some(x) = x.checked_sub(1) {
+ base_n::push_str(x as u128, 62, &mut self.out);
+ }
+ self.push("_");
+ }
+
+ /// 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) {
+ 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 {
+ self.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!(self.out, "{}", ident.len());
+
+ // Write a separating `_` if necessary (leading digit or `_`).
+ if let Some('_' | '0'..='9') = ident.chars().next() {
+ self.push("_");
+ }
+
+ self.push(ident);
+ }
+
+ fn path_append_ns<'a>(
+ mut self: &'a mut Self,
+ print_prefix: impl FnOnce(&'a mut Self) -> Result<&'a mut Self, !>,
+ ns: char,
+ disambiguator: u64,
+ name: &str,
+ ) -> Result<&'a mut Self, !> {
+ self.push("N");
+ self.out.push(ns);
+ self = print_prefix(self)?;
+ self.push_disambiguator(disambiguator as u64);
+ self.push_ident(name);
+ Ok(self)
+ }
+
+ fn print_backref(&mut self, i: usize) -> Result<&mut Self, !> {
+ self.push("B");
+ self.push_integer_62((i - self.start_offset) as u64);
+ Ok(self)
+ }
+
+ fn in_binder<'a, T>(
+ mut self: &'a mut Self,
+ value: &ty::Binder<'tcx, T>,
+ print_value: impl FnOnce(&'a mut Self, &T) -> Result<&'a mut Self, !>,
+ ) -> Result<&'a mut Self, !>
+ where
+ T: TypeVisitable<'tcx>,
+ {
+ let regions = if value.has_late_bound_regions() {
+ self.tcx.collect_referenced_late_bound_regions(value)
+ } else {
+ FxHashSet::default()
+ };
+
+ let mut lifetime_depths =
+ self.binders.last().map(|b| b.lifetime_depths.end).map_or(0..0, |i| i..i);
+
+ let lifetimes = regions
+ .into_iter()
+ .map(|br| match br {
+ ty::BrAnon(i) => i,
+ _ => bug!("symbol_names: non-anonymized region `{:?}` in `{:?}`", br, value),
+ })
+ .max()
+ .map_or(0, |max| max + 1);
+
+ self.push_opt_integer_62("G", lifetimes as u64);
+ lifetime_depths.end += lifetimes;
+
+ self.binders.push(BinderLevel { lifetime_depths });
+ self = print_value(self, value.as_ref().skip_binder())?;
+ self.binders.pop();
+
+ Ok(self)
+ }
+}
+
+impl<'tcx> Printer<'tcx> for &mut SymbolMangler<'tcx> {
+ type Error = !;
+
+ type Path = Self;
+ type Region = Self;
+ type Type = Self;
+ type DynExistential = Self;
+ type Const = Self;
+
+ fn tcx(&self) -> TyCtxt<'tcx> {
+ self.tcx
+ }
+
+ fn print_def_path(
+ mut self,
+ def_id: DefId,
+ substs: &'tcx [GenericArg<'tcx>],
+ ) -> Result<Self::Path, Self::Error> {
+ if let Some(&i) = self.paths.get(&(def_id, substs)) {
+ return self.print_backref(i);
+ }
+ let start = self.out.len();
+
+ self = self.default_print_def_path(def_id, substs)?;
+
+ // Only cache paths that do not refer to an enclosing
+ // binder (which would change depending on context).
+ if !substs.iter().any(|k| k.has_escaping_bound_vars()) {
+ self.paths.insert((def_id, substs), start);
+ }
+ Ok(self)
+ }
+
+ fn print_impl_path(
+ mut self,
+ impl_def_id: DefId,
+ substs: &'tcx [GenericArg<'tcx>],
+ mut self_ty: Ty<'tcx>,
+ mut impl_trait_ref: Option<ty::TraitRef<'tcx>>,
+ ) -> Result<Self::Path, Self::Error> {
+ 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 !substs.is_empty() {
+ param_env = EarlyBinder(param_env).subst(self.tcx, substs);
+ }
+
+ 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 substitutions contain parameters (implying
+ // polymorphization is enabled) and this isn't an inherent impl.
+ if impl_trait_ref.is_some() && substs.iter().any(|a| a.has_param_types_or_consts()) {
+ self = self.path_generic_args(
+ |this| {
+ this.path_append_ns(
+ |cx| cx.print_def_path(parent_def_id, &[]),
+ 'I',
+ key.disambiguated_data.disambiguator as u64,
+ "",
+ )
+ },
+ substs,
+ )?;
+ } else {
+ self.push_disambiguator(key.disambiguated_data.disambiguator as u64);
+ self = self.print_def_path(parent_def_id, &[])?;
+ }
+
+ self = self_ty.print(self)?;
+
+ if let Some(trait_ref) = impl_trait_ref {
+ self = self.print_def_path(trait_ref.def_id, trait_ref.substs)?;
+ }
+
+ Ok(self)
+ }
+
+ fn print_region(self, region: ty::Region<'_>) -> Result<Self::Region, Self::Error> {
+ let i = match *region {
+ // Erased lifetimes use the index 0, for a
+ // shorter mangling of `L_`.
+ ty::ReErased => 0,
+
+ // Late-bound lifetimes use indices starting at 1,
+ // see `BinderLevel` for more details.
+ ty::ReLateBound(debruijn, ty::BoundRegion { kind: ty::BrAnon(i), .. }) => {
+ let binder = &self.binders[self.binders.len() - 1 - debruijn.index()];
+ let depth = binder.lifetime_depths.start + i;
+
+ 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(self)
+ }
+
+ fn print_type(mut self, ty: Ty<'tcx>) -> Result<Self::Type, Self::Error> {
+ // 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::F32) => "f",
+ ty::Float(FloatTy::F64) => "d",
+ ty::Never => "z",
+
+ // Placeholders (should be demangled as `_`).
+ ty::Param(_) | ty::Bound(..) | ty::Placeholder(_) | ty::Infer(_) | ty::Error(_) => "p",
+
+ _ => "",
+ };
+ if !basic_type.is_empty() {
+ self.push(basic_type);
+ return Ok(self);
+ }
+
+ 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() {
+ self = r.print(self)?;
+ }
+ self = ty.print(self)?;
+ }
+
+ ty::RawPtr(mt) => {
+ self.push(match mt.mutbl {
+ hir::Mutability::Not => "P",
+ hir::Mutability::Mut => "O",
+ });
+ self = mt.ty.print(self)?;
+ }
+
+ ty::Array(ty, len) => {
+ self.push("A");
+ self = ty.print(self)?;
+ self = self.print_const(len)?;
+ }
+ ty::Slice(ty) => {
+ self.push("S");
+ self = ty.print(self)?;
+ }
+
+ ty::Tuple(tys) => {
+ self.push("T");
+ for ty in tys.iter() {
+ self = ty.print(self)?;
+ }
+ self.push("E");
+ }
+
+ // Mangle all nominal types as paths.
+ ty::Adt(ty::AdtDef(Interned(&ty::AdtDefData { did: def_id, .. }, _)), substs)
+ | ty::FnDef(def_id, substs)
+ | ty::Opaque(def_id, substs)
+ | ty::Projection(ty::ProjectionTy { item_def_id: def_id, substs })
+ | ty::Closure(def_id, substs)
+ | ty::Generator(def_id, substs, _) => {
+ self = self.print_def_path(def_id, substs)?;
+ }
+ ty::Foreign(def_id) => {
+ self = self.print_def_path(def_id, &[])?;
+ }
+
+ ty::FnPtr(sig) => {
+ self.push("F");
+ self = self.in_binder(&sig, |mut cx, sig| {
+ if sig.unsafety == hir::Unsafety::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() {
+ cx = ty.print(cx)?;
+ }
+ if sig.c_variadic {
+ cx.push("v");
+ }
+ cx.push("E");
+ sig.output().print(cx)
+ })?;
+ }
+
+ ty::Dynamic(predicates, r) => {
+ self.push("D");
+ self = self.print_dyn_existential(predicates)?;
+ self = r.print(self)?;
+ }
+
+ ty::GeneratorWitness(_) => bug!("symbol_names: unexpected `GeneratorWitness`"),
+ }
+
+ // 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(self)
+ }
+
+ fn print_dyn_existential(
+ mut self,
+ predicates: &'tcx ty::List<ty::Binder<'tcx, ty::ExistentialPredicate<'tcx>>>,
+ ) -> Result<Self::DynExistential, Self::Error> {
+ // 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 = self.in_binder(&predicates[0], |mut 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 = cx.tcx.mk_ty_infer(ty::FreshTy(0));
+ let trait_ref = trait_ref.with_self_ty(cx.tcx, dummy_self);
+ cx = cx.print_def_path(trait_ref.def_id, trait_ref.substs)?;
+ }
+ ty::ExistentialPredicate::Projection(projection) => {
+ let name = cx.tcx.associated_item(projection.item_def_id).name;
+ cx.push("p");
+ cx.push_ident(name.as_str());
+ cx = match projection.term {
+ ty::Term::Ty(ty) => ty.print(cx),
+ ty::Term::Const(c) => c.print(cx),
+ }?;
+ }
+ ty::ExistentialPredicate::AutoTrait(def_id) => {
+ cx = cx.print_def_path(*def_id, &[])?;
+ }
+ }
+ }
+ Ok(cx)
+ })?;
+
+ self.push("E");
+ Ok(self)
+ }
+
+ fn print_const(mut self, ct: ty::Const<'tcx>) -> Result<Self::Const, Self::Error> {
+ // We only mangle a typed value if the const can be evaluated.
+ let ct = ct.eval(self.tcx, ty::ParamEnv::reveal_all());
+ match ct.kind() {
+ ty::ConstKind::Value(_) => {}
+
+ // Placeholders (should be demangled as `_`).
+ // NOTE(eddyb) despite `Unevaluated` having a `DefId` (and therefore
+ // a path), even for it we still need to encode a placeholder, as
+ // the path could refer back to e.g. an `impl` using the constant.
+ ty::ConstKind::Unevaluated(_)
+ | ty::ConstKind::Param(_)
+ | ty::ConstKind::Infer(_)
+ | ty::ConstKind::Bound(..)
+ | ty::ConstKind::Placeholder(_)
+ | ty::ConstKind::Error(_) => {
+ // Never cached (single-character).
+ self.push("p");
+ return Ok(self);
+ }
+ }
+
+ if let Some(&i) = self.consts.get(&ct) {
+ return self.print_backref(i);
+ }
+
+ let start = self.out.len();
+ let ty = ct.ty();
+
+ match ty.kind() {
+ ty::Uint(_) | ty::Int(_) | ty::Bool | ty::Char => {
+ self = ty.print(self)?;
+
+ let mut bits = ct.eval_bits(self.tcx, ty::ParamEnv::reveal_all(), ty);
+
+ // Negative integer values are mangled using `n` as a "sign prefix".
+ if let ty::Int(ity) = 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, "{:x}_", bits);
+ }
+
+ // FIXME(valtrees): Remove the special case for `str`
+ // here and fully support unsized constants.
+ ty::Ref(_, inner_ty, mutbl) => {
+ self.push(match mutbl {
+ hir::Mutability::Not => "R",
+ hir::Mutability::Mut => "Q",
+ });
+
+ match inner_ty.kind() {
+ ty::Str if *mutbl == hir::Mutability::Not => {
+ match ct.kind() {
+ ty::ConstKind::Value(valtree) => {
+ let slice =
+ valtree.try_to_raw_bytes(self.tcx(), ty).unwrap_or_else(|| {
+ bug!(
+ "expected to get raw bytes from valtree {:?} for type {:}",
+ valtree, ty
+ )
+ });
+ let s = std::str::from_utf8(slice).expect("non utf8 str from miri");
+
+ self.push("e");
+
+ // FIXME(eddyb) use a specialized hex-encoding loop.
+ for byte in s.bytes() {
+ let _ = write!(self.out, "{:02x}", byte);
+ }
+
+ self.push("_");
+ }
+
+ _ => {
+ bug!("symbol_names: unsupported `&str` constant: {:?}", ct);
+ }
+ }
+ }
+ _ => {
+ let pointee_ty = ct
+ .ty()
+ .builtin_deref(true)
+ .expect("tried to dereference on non-ptr type")
+ .ty;
+ let dereferenced_const =
+ self.tcx.mk_const(ty::ConstS { kind: ct.kind(), ty: pointee_ty });
+ self = 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 = |mut this: Self| {
+ for field in fields.clone() {
+ this = field.print(this)?;
+ }
+ this.push("E");
+ Ok(this)
+ };
+
+ match *ct.ty().kind() {
+ ty::Array(..) | ty::Slice(_) => {
+ self.push("A");
+ self = print_field_list(self)?;
+ }
+ ty::Tuple(..) => {
+ self.push("T");
+ self = print_field_list(self)?;
+ }
+ ty::Adt(def, substs) => {
+ let variant_idx =
+ contents.variant.expect("destructed const of adt without variant idx");
+ let variant_def = &def.variant(variant_idx);
+
+ self.push("V");
+ self = self.print_def_path(variant_def.def_id, substs)?;
+
+ match variant_def.ctor_kind {
+ CtorKind::Const => {
+ self.push("U");
+ }
+ CtorKind::Fn => {
+ self.push("T");
+ self = print_field_list(self)?;
+ }
+ CtorKind::Fictive => {
+ 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());
+
+ self = 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(self)
+ }
+
+ fn path_crate(self, cnum: CrateNum) -> Result<Self::Path, Self::Error> {
+ 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.to_u64());
+ let name = self.tcx.crate_name(cnum);
+ self.push_ident(name.as_str());
+ Ok(self)
+ }
+
+ fn path_qualified(
+ mut self,
+ self_ty: Ty<'tcx>,
+ trait_ref: Option<ty::TraitRef<'tcx>>,
+ ) -> Result<Self::Path, Self::Error> {
+ assert!(trait_ref.is_some());
+ let trait_ref = trait_ref.unwrap();
+
+ self.push("Y");
+ self = self_ty.print(self)?;
+ self.print_def_path(trait_ref.def_id, trait_ref.substs)
+ }
+
+ fn path_append_impl(
+ self,
+ _: impl FnOnce(Self) -> Result<Self::Path, Self::Error>,
+ _: &DisambiguatedDefPathData,
+ _: Ty<'tcx>,
+ _: Option<ty::TraitRef<'tcx>>,
+ ) -> Result<Self::Path, Self::Error> {
+ // Inlined into `print_impl_path`
+ unreachable!()
+ }
+
+ fn path_append(
+ self,
+ print_prefix: impl FnOnce(Self) -> Result<Self::Path, Self::Error>,
+ disambiguated_data: &DisambiguatedDefPathData,
+ ) -> Result<Self::Path, Self::Error> {
+ 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::ClosureExpr => 'C',
+ DefPathData::Ctor => 'c',
+ DefPathData::AnonConst => 'k',
+ DefPathData::ImplTrait => 'i',
+
+ // These should never show up as `path_append` arguments.
+ DefPathData::CrateRoot
+ | DefPathData::Use
+ | DefPathData::GlobalAsm
+ | DefPathData::Impl
+ | DefPathData::MacroNs(_)
+ | DefPathData::LifetimeNs(_) => {
+ 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(Self) -> Result<Self::Path, Self::Error>,
+ args: &[GenericArg<'tcx>],
+ ) -> Result<Self::Path, Self::Error> {
+ // 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");
+ self = print_prefix(self)?;
+ for arg in args {
+ match arg.unpack() {
+ GenericArgKind::Lifetime(lt) => {
+ self = lt.print(self)?;
+ }
+ GenericArgKind::Type(ty) => {
+ self = ty.print(self)?;
+ }
+ GenericArgKind::Const(c) => {
+ self.push("K");
+ self = c.print(self)?;
+ }
+ }
+ }
+ self.push("E");
+
+ Ok(self)
+ }
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-06-12 08:32:40 +0000