From bc8c3eff6b821298d96055f27a55985a573af44f Mon Sep 17 00:00:00 2001 From: Ramon de C Valle Date: Fri, 29 Mar 2024 17:13:19 -0700 Subject: [PATCH] CFI: Change type transformation to use TypeFolder Change type transformation to use TypeFolder. --- .../src/typeid/typeid_itanium_cxx_abi.rs | 428 ++++++++---------- 1 file changed, 177 insertions(+), 251 deletions(-) diff --git a/compiler/rustc_symbol_mangling/src/typeid/typeid_itanium_cxx_abi.rs b/compiler/rustc_symbol_mangling/src/typeid/typeid_itanium_cxx_abi.rs index 5963bd7c5f16c..85f1cd27cded5 100644 --- a/compiler/rustc_symbol_mangling/src/typeid/typeid_itanium_cxx_abi.rs +++ b/compiler/rustc_symbol_mangling/src/typeid/typeid_itanium_cxx_abi.rs @@ -11,13 +11,14 @@ use rustc_data_structures::base_n; use rustc_data_structures::fx::FxHashMap; use rustc_hir as hir; use rustc_hir::lang_items::LangItem; +use rustc_middle::ty::fold::{TypeFolder, TypeSuperFoldable}; use rustc_middle::ty::layout::IntegerExt; -use rustc_middle::ty::TypeVisitableExt; use rustc_middle::ty::{ self, Const, ExistentialPredicate, FloatTy, FnSig, Instance, IntTy, List, Region, RegionKind, TermKind, Ty, TyCtxt, UintTy, }; use rustc_middle::ty::{GenericArg, GenericArgKind, GenericArgsRef}; +use rustc_middle::ty::{TypeFoldable, TypeVisitableExt}; use rustc_span::def_id::DefId; use rustc_span::sym; use rustc_target::abi::call::{Conv, FnAbi, PassMode}; @@ -182,14 +183,15 @@ fn encode_fnsig<'tcx>( // Encode the return type let transform_ty_options = TransformTyOptions::from_bits(options.bits()) .unwrap_or_else(|| bug!("encode_fnsig: invalid option(s) `{:?}`", options.bits())); - let ty = transform_ty(tcx, fn_sig.output(), &mut Vec::new(), transform_ty_options); + let mut type_folder = TransformTy::new(tcx, transform_ty_options); + let ty = fn_sig.output().fold_with(&mut type_folder); s.push_str(&encode_ty(tcx, ty, dict, encode_ty_options)); // Encode the parameter types let tys = fn_sig.inputs(); if !tys.is_empty() { for ty in tys { - let ty = transform_ty(tcx, *ty, &mut Vec::new(), transform_ty_options); + let ty = ty.fold_with(&mut type_folder); s.push_str(&encode_ty(tcx, ty, dict, encode_ty_options)); } @@ -523,15 +525,9 @@ fn encode_ty<'tcx>( ty::Array(ty0, len) => { // A + let len = len.eval_target_usize(tcx, ty::ParamEnv::reveal_all()); let mut s = String::from("A"); - let _ = write!( - s, - "{}", - &len.try_to_scalar() - .unwrap() - .to_target_usize(&tcx.data_layout) - .expect("Array lens are defined in usize") - ); + let _ = write!(s, "{}", &len); s.push_str(&encode_ty(tcx, *ty0, dict, options)); compress(dict, DictKey::Ty(ty, TyQ::None), &mut s); typeid.push_str(&s); @@ -756,278 +752,208 @@ fn encode_ty<'tcx>( typeid } -/// Transforms predicates for being encoded and used in the substitution dictionary. -fn transform_predicates<'tcx>( +struct TransformTy<'tcx> { tcx: TyCtxt<'tcx>, - predicates: &List>, -) -> &'tcx List> { - tcx.mk_poly_existential_predicates_from_iter(predicates.iter().filter_map(|predicate| { - match predicate.skip_binder() { - ty::ExistentialPredicate::Trait(trait_ref) => { - let trait_ref = ty::TraitRef::identity(tcx, trait_ref.def_id); - Some(ty::Binder::dummy(ty::ExistentialPredicate::Trait( - ty::ExistentialTraitRef::erase_self_ty(tcx, trait_ref), - ))) - } - ty::ExistentialPredicate::Projection(..) => None, - ty::ExistentialPredicate::AutoTrait(..) => Some(predicate), - } - })) -} - -/// Transforms args for being encoded and used in the substitution dictionary. -fn transform_args<'tcx>( - tcx: TyCtxt<'tcx>, - args: GenericArgsRef<'tcx>, - parents: &mut Vec>, options: TransformTyOptions, -) -> GenericArgsRef<'tcx> { - let args = args.iter().map(|arg| match arg.unpack() { - GenericArgKind::Type(ty) if ty.is_c_void(tcx) => Ty::new_unit(tcx).into(), - GenericArgKind::Type(ty) => transform_ty(tcx, ty, parents, options).into(), - _ => arg, - }); - tcx.mk_args_from_iter(args) + parents: Vec>, } -// Transforms a ty:Ty for being encoded and used in the substitution dictionary. It transforms all -// c_void types into unit types unconditionally, generalizes pointers if -// TransformTyOptions::GENERALIZE_POINTERS option is set, and normalizes integers if -// TransformTyOptions::NORMALIZE_INTEGERS option is set. -fn transform_ty<'tcx>( - tcx: TyCtxt<'tcx>, - mut ty: Ty<'tcx>, - parents: &mut Vec>, - options: TransformTyOptions, -) -> Ty<'tcx> { - match ty.kind() { - ty::Float(..) | ty::Str | ty::Never | ty::Foreign(..) | ty::CoroutineWitness(..) => {} +impl<'tcx> TransformTy<'tcx> { + fn new(tcx: TyCtxt<'tcx>, options: TransformTyOptions) -> Self { + TransformTy { tcx, options, parents: Vec::new() } + } +} - ty::Bool => { - if options.contains(EncodeTyOptions::NORMALIZE_INTEGERS) { - // Note: on all platforms that Rust's currently supports, its size and alignment are - // 1, and its ABI class is INTEGER - see Rust Layout and ABIs. - // - // (See https://rust-lang.github.io/unsafe-code-guidelines/layout/scalars.html#bool.) - // - // Clang represents bool as an 8-bit unsigned integer. - ty = tcx.types.u8; +impl<'tcx> TypeFolder> for TransformTy<'tcx> { + // Transforms a ty:Ty for being encoded and used in the substitution dictionary. It transforms + // all c_void types into unit types unconditionally, generalizes pointers if + // TransformTyOptions::GENERALIZE_POINTERS option is set, and normalizes integers if + // TransformTyOptions::NORMALIZE_INTEGERS option is set. + fn fold_ty(&mut self, t: Ty<'tcx>) -> Ty<'tcx> { + match t.kind() { + ty::Array(..) + | ty::Closure(..) + | ty::Coroutine(..) + | ty::CoroutineClosure(..) + | ty::CoroutineWitness(..) + | ty::Float(..) + | ty::FnDef(..) + | ty::Foreign(..) + | ty::Never + | ty::Slice(..) + | ty::Str + | ty::Tuple(..) => t.super_fold_with(self), + + ty::Bool => { + if self.options.contains(EncodeTyOptions::NORMALIZE_INTEGERS) { + // Note: on all platforms that Rust's currently supports, its size and alignment + // are 1, and its ABI class is INTEGER - see Rust Layout and ABIs. + // + // (See https://rust-lang.github.io/unsafe-code-guidelines/layout/scalars.html#bool.) + // + // Clang represents bool as an 8-bit unsigned integer. + self.tcx.types.u8 + } else { + t + } } - } - ty::Char => { - if options.contains(EncodeTyOptions::NORMALIZE_INTEGERS) { - // Since #118032, char is guaranteed to have the same size, alignment, and function - // call ABI as u32 on all platforms. - ty = tcx.types.u32; + ty::Char => { + if self.options.contains(EncodeTyOptions::NORMALIZE_INTEGERS) { + // Since #118032, char is guaranteed to have the same size, alignment, and + // function call ABI as u32 on all platforms. + self.tcx.types.u32 + } else { + t + } } - } - ty::Int(..) | ty::Uint(..) => { - if options.contains(EncodeTyOptions::NORMALIZE_INTEGERS) { - // Note: C99 7.18.2.4 requires uintptr_t and intptr_t to be at least 16-bit wide. - // All platforms we currently support have a C platform, and as a consequence, - // isize/usize are at least 16-bit wide for all of them. - // - // (See https://rust-lang.github.io/unsafe-code-guidelines/layout/scalars.html#isize-and-usize.) - match ty.kind() { - ty::Int(IntTy::Isize) => match tcx.sess.target.pointer_width { - 16 => ty = tcx.types.i16, - 32 => ty = tcx.types.i32, - 64 => ty = tcx.types.i64, - 128 => ty = tcx.types.i128, - _ => bug!( - "transform_ty: unexpected pointer width `{}`", - tcx.sess.target.pointer_width - ), - }, - ty::Uint(UintTy::Usize) => match tcx.sess.target.pointer_width { - 16 => ty = tcx.types.u16, - 32 => ty = tcx.types.u32, - 64 => ty = tcx.types.u64, - 128 => ty = tcx.types.u128, - _ => bug!( - "transform_ty: unexpected pointer width `{}`", - tcx.sess.target.pointer_width - ), - }, - _ => (), + ty::Int(..) | ty::Uint(..) => { + if self.options.contains(EncodeTyOptions::NORMALIZE_INTEGERS) { + // Note: C99 7.18.2.4 requires uintptr_t and intptr_t to be at least 16-bit + // wide. All platforms we currently support have a C platform, and as a + // consequence, isize/usize are at least 16-bit wide for all of them. + // + // (See https://rust-lang.github.io/unsafe-code-guidelines/layout/scalars.html#isize-and-usize.) + match t.kind() { + ty::Int(IntTy::Isize) => match self.tcx.sess.target.pointer_width { + 16 => self.tcx.types.i16, + 32 => self.tcx.types.i32, + 64 => self.tcx.types.i64, + 128 => self.tcx.types.i128, + _ => bug!( + "fold_ty: unexpected pointer width `{}`", + self.tcx.sess.target.pointer_width + ), + }, + ty::Uint(UintTy::Usize) => match self.tcx.sess.target.pointer_width { + 16 => self.tcx.types.u16, + 32 => self.tcx.types.u32, + 64 => self.tcx.types.u64, + 128 => self.tcx.types.u128, + _ => bug!( + "fold_ty: unexpected pointer width `{}`", + self.tcx.sess.target.pointer_width + ), + }, + _ => t, + } + } else { + t } } - } - - _ if ty.is_unit() => {} - ty::Tuple(tys) => { - ty = Ty::new_tup_from_iter( - tcx, - tys.iter().map(|ty| transform_ty(tcx, ty, parents, options)), - ); - } + ty::Adt(..) if t.is_c_void(self.tcx) => self.tcx.types.unit, - ty::Array(ty0, len) => { - let len = len.eval_target_usize(tcx, ty::ParamEnv::reveal_all()); - - ty = Ty::new_array(tcx, transform_ty(tcx, *ty0, parents, options), len); - } - - ty::Slice(ty0) => { - ty = Ty::new_slice(tcx, transform_ty(tcx, *ty0, parents, options)); - } - - ty::Adt(adt_def, args) => { - if ty.is_c_void(tcx) { - ty = Ty::new_unit(tcx); - } else if options.contains(TransformTyOptions::GENERALIZE_REPR_C) && adt_def.repr().c() - { - ty = Ty::new_adt(tcx, *adt_def, ty::List::empty()); - } else if adt_def.repr().transparent() && adt_def.is_struct() && !parents.contains(&ty) - { - // Don't transform repr(transparent) types with an user-defined CFI encoding to - // preserve the user-defined CFI encoding. - if let Some(_) = tcx.get_attr(adt_def.did(), sym::cfi_encoding) { - return ty; - } - let variant = adt_def.non_enum_variant(); - let param_env = tcx.param_env(variant.def_id); - let field = variant.fields.iter().find(|field| { - let ty = tcx.type_of(field.did).instantiate_identity(); - let is_zst = - tcx.layout_of(param_env.and(ty)).is_ok_and(|layout| layout.is_zst()); - !is_zst - }); - if let Some(field) = field { - let ty0 = tcx.type_of(field.did).instantiate(tcx, args); - // Generalize any repr(transparent) user-defined type that is either a pointer - // or reference, and either references itself or any other type that contains or - // references itself, to avoid a reference cycle. - - // If the self reference is not through a pointer, for example, due - // to using `PhantomData`, need to skip normalizing it if we hit it again. - parents.push(ty); - if ty0.is_any_ptr() && ty0.contains(ty) { - ty = transform_ty( - tcx, - ty0, - parents, - options | TransformTyOptions::GENERALIZE_POINTERS, - ); + ty::Adt(adt_def, args) => { + if adt_def.repr().transparent() && adt_def.is_struct() && !self.parents.contains(&t) + { + // Don't transform repr(transparent) types with an user-defined CFI encoding to + // preserve the user-defined CFI encoding. + if let Some(_) = self.tcx.get_attr(adt_def.did(), sym::cfi_encoding) { + return t; + } + let variant = adt_def.non_enum_variant(); + let param_env = self.tcx.param_env(variant.def_id); + let field = variant.fields.iter().find(|field| { + let ty = self.tcx.type_of(field.did).instantiate_identity(); + let is_zst = self + .tcx + .layout_of(param_env.and(ty)) + .is_ok_and(|layout| layout.is_zst()); + !is_zst + }); + if let Some(field) = field { + let ty0 = self.tcx.type_of(field.did).instantiate(self.tcx, args); + // Generalize any repr(transparent) user-defined type that is either a + // pointer or reference, and either references itself or any other type that + // contains or references itself, to avoid a reference cycle. + + // If the self reference is not through a pointer, for example, due + // to using `PhantomData`, need to skip normalizing it if we hit it again. + self.parents.push(t); + let ty = if ty0.is_any_ptr() && ty0.contains(t) { + let options = self.options; + self.options |= TransformTyOptions::GENERALIZE_POINTERS; + let ty = ty0.fold_with(self); + self.options = options; + ty + } else { + ty0.fold_with(self) + }; + self.parents.pop(); + ty } else { - ty = transform_ty(tcx, ty0, parents, options); + // Transform repr(transparent) types without non-ZST field into () + self.tcx.types.unit } - parents.pop(); } else { - // Transform repr(transparent) types without non-ZST field into () - ty = Ty::new_unit(tcx); + t.super_fold_with(self) } - } else { - ty = Ty::new_adt(tcx, *adt_def, transform_args(tcx, args, parents, options)); } - } - - ty::FnDef(def_id, args) => { - ty = Ty::new_fn_def(tcx, *def_id, transform_args(tcx, args, parents, options)); - } - - ty::Closure(def_id, args) => { - ty = Ty::new_closure(tcx, *def_id, transform_args(tcx, args, parents, options)); - } - - ty::CoroutineClosure(def_id, args) => { - ty = Ty::new_coroutine_closure( - tcx, - *def_id, - transform_args(tcx, args, parents, options), - ); - } - ty::Coroutine(def_id, args) => { - ty = Ty::new_coroutine(tcx, *def_id, transform_args(tcx, args, parents, options)); - } - - ty::Ref(region, ty0, ..) => { - if options.contains(TransformTyOptions::GENERALIZE_POINTERS) { - if ty.is_mutable_ptr() { - ty = Ty::new_mut_ref(tcx, tcx.lifetimes.re_static, Ty::new_unit(tcx)); - } else { - ty = Ty::new_imm_ref(tcx, tcx.lifetimes.re_static, Ty::new_unit(tcx)); - } - } else { - if ty.is_mutable_ptr() { - ty = Ty::new_mut_ref(tcx, *region, transform_ty(tcx, *ty0, parents, options)); + ty::Ref(..) => { + if self.options.contains(TransformTyOptions::GENERALIZE_POINTERS) { + if t.is_mutable_ptr() { + Ty::new_mut_ref(self.tcx, self.tcx.lifetimes.re_static, self.tcx.types.unit) + } else { + Ty::new_imm_ref(self.tcx, self.tcx.lifetimes.re_static, self.tcx.types.unit) + } } else { - ty = Ty::new_imm_ref(tcx, *region, transform_ty(tcx, *ty0, parents, options)); + t.super_fold_with(self) } } - } - ty::RawPtr(ptr_ty, _) => { - if options.contains(TransformTyOptions::GENERALIZE_POINTERS) { - if ty.is_mutable_ptr() { - ty = Ty::new_mut_ptr(tcx, Ty::new_unit(tcx)); + ty::RawPtr(..) => { + if self.options.contains(TransformTyOptions::GENERALIZE_POINTERS) { + if t.is_mutable_ptr() { + Ty::new_mut_ptr(self.tcx, self.tcx.types.unit) + } else { + Ty::new_imm_ptr(self.tcx, self.tcx.types.unit) + } } else { - ty = Ty::new_imm_ptr(tcx, Ty::new_unit(tcx)); + t.super_fold_with(self) } - } else { - if ty.is_mutable_ptr() { - ty = Ty::new_mut_ptr(tcx, transform_ty(tcx, *ptr_ty, parents, options)); + } + + ty::FnPtr(..) => { + if self.options.contains(TransformTyOptions::GENERALIZE_POINTERS) { + Ty::new_imm_ptr(self.tcx, self.tcx.types.unit) } else { - ty = Ty::new_imm_ptr(tcx, transform_ty(tcx, *ptr_ty, parents, options)); + t.super_fold_with(self) } } - } - ty::FnPtr(fn_sig) => { - if options.contains(TransformTyOptions::GENERALIZE_POINTERS) { - ty = Ty::new_imm_ptr(tcx, Ty::new_unit(tcx)); - } else { - let parameters: Vec> = fn_sig - .skip_binder() - .inputs() - .iter() - .map(|ty| transform_ty(tcx, *ty, parents, options)) - .collect(); - let output = transform_ty(tcx, fn_sig.skip_binder().output(), parents, options); - ty = Ty::new_fn_ptr( - tcx, - ty::Binder::bind_with_vars( - tcx.mk_fn_sig( - parameters, - output, - fn_sig.c_variadic(), - fn_sig.unsafety(), - fn_sig.abi(), - ), - fn_sig.bound_vars(), - ), + ty::Dynamic(predicates, _region, kind) => { + let predicates = self.tcx.mk_poly_existential_predicates_from_iter( + predicates.iter().filter_map(|predicate| match predicate.skip_binder() { + ty::ExistentialPredicate::Trait(trait_ref) => { + let trait_ref = ty::TraitRef::identity(self.tcx, trait_ref.def_id); + Some(ty::Binder::dummy(ty::ExistentialPredicate::Trait( + ty::ExistentialTraitRef::erase_self_ty(self.tcx, trait_ref), + ))) + } + ty::ExistentialPredicate::Projection(..) => None, + ty::ExistentialPredicate::AutoTrait(..) => Some(predicate), + }), ); - } - } - ty::Dynamic(predicates, _region, kind) => { - ty = Ty::new_dynamic( - tcx, - transform_predicates(tcx, predicates), - tcx.lifetimes.re_erased, - *kind, - ); - } + Ty::new_dynamic(self.tcx, predicates, self.tcx.lifetimes.re_erased, *kind) + } - ty::Alias(..) => { - ty = transform_ty( - tcx, - tcx.normalize_erasing_regions(ty::ParamEnv::reveal_all(), ty), - parents, - options, - ); - } + ty::Alias(..) => { + self.fold_ty(self.tcx.normalize_erasing_regions(ty::ParamEnv::reveal_all(), t)) + } - ty::Bound(..) | ty::Error(..) | ty::Infer(..) | ty::Param(..) | ty::Placeholder(..) => { - bug!("transform_ty: unexpected `{:?}`", ty.kind()); + ty::Bound(..) | ty::Error(..) | ty::Infer(..) | ty::Param(..) | ty::Placeholder(..) => { + bug!("fold_ty: unexpected `{:?}`", t.kind()); + } } } - ty + fn interner(&self) -> TyCtxt<'tcx> { + self.tcx + } } /// Returns a type metadata identifier for the specified FnAbi using the Itanium C++ ABI with vendor @@ -1068,7 +994,8 @@ pub fn typeid_for_fnabi<'tcx>( // Encode the return type let transform_ty_options = TransformTyOptions::from_bits(options.bits()) .unwrap_or_else(|| bug!("typeid_for_fnabi: invalid option(s) `{:?}`", options.bits())); - let ty = transform_ty(tcx, fn_abi.ret.layout.ty, &mut Vec::new(), transform_ty_options); + let mut type_folder = TransformTy::new(tcx, transform_ty_options); + let ty = fn_abi.ret.layout.ty.fold_with(&mut type_folder); typeid.push_str(&encode_ty(tcx, ty, &mut dict, encode_ty_options)); // Encode the parameter types @@ -1080,7 +1007,7 @@ pub fn typeid_for_fnabi<'tcx>( let mut pushed_arg = false; for arg in fn_abi.args.iter().filter(|arg| arg.mode != PassMode::Ignore) { pushed_arg = true; - let ty = transform_ty(tcx, arg.layout.ty, &mut Vec::new(), transform_ty_options); + let ty = arg.layout.ty.fold_with(&mut type_folder); typeid.push_str(&encode_ty(tcx, ty, &mut dict, encode_ty_options)); } if !pushed_arg { @@ -1093,8 +1020,7 @@ pub fn typeid_for_fnabi<'tcx>( if fn_abi.args[n].mode == PassMode::Ignore { continue; } - let ty = - transform_ty(tcx, fn_abi.args[n].layout.ty, &mut Vec::new(), transform_ty_options); + let ty = fn_abi.args[n].layout.ty.fold_with(&mut type_folder); typeid.push_str(&encode_ty(tcx, ty, &mut dict, encode_ty_options)); }