| // Copyright (C) 2020-2023 Free Software Foundation, Inc. |
| |
| // This file is part of GCC. |
| |
| // GCC is free software; you can redistribute it and/or modify it under |
| // the terms of the GNU General Public License as published by the Free |
| // Software Foundation; either version 3, or (at your option) any later |
| // version. |
| |
| // GCC is distributed in the hope that it will be useful, but WITHOUT ANY |
| // WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| // FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| // for more details. |
| |
| // You should have received a copy of the GNU General Public License |
| // along with GCC; see the file COPYING3. If not see |
| // <http://www.gnu.org/licenses/>. |
| |
| #include "rust-casts.h" |
| |
| namespace Rust { |
| namespace Resolver { |
| |
| TypeCastRules::TypeCastRules (Location locus, TyTy::TyWithLocation from, |
| TyTy::TyWithLocation to) |
| : locus (locus), from (from), to (to) |
| {} |
| |
| TypeCoercionRules::CoercionResult |
| TypeCastRules::resolve (Location locus, TyTy::TyWithLocation from, |
| TyTy::TyWithLocation to) |
| { |
| TypeCastRules cast_rules (locus, from, to); |
| return cast_rules.check (); |
| } |
| |
| TypeCoercionRules::CoercionResult |
| TypeCastRules::check () |
| { |
| // https://github.com/rust-lang/rust/blob/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4/compiler/rustc_typeck/src/check/cast.rs#L565-L582 |
| auto possible_coercion |
| = TypeCoercionRules::TryCoerce (from.get_ty (), to.get_ty (), locus); |
| if (!possible_coercion.is_error ()) |
| return possible_coercion; |
| |
| // try the simple cast rules |
| auto simple_cast = cast_rules (); |
| if (!simple_cast.is_error ()) |
| return simple_cast; |
| |
| // failed to cast |
| emit_cast_error (); |
| return TypeCoercionRules::CoercionResult::get_error (); |
| } |
| |
| TypeCoercionRules::CoercionResult |
| TypeCastRules::cast_rules () |
| { |
| // https://github.com/rust-lang/rust/blob/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4/compiler/rustc_typeck/src/check/cast.rs#L596 |
| // https://github.com/rust-lang/rust/blob/7eac88abb2e57e752f3302f02be5f3ce3d7adfb4/compiler/rustc_typeck/src/check/cast.rs#L654 |
| |
| rust_debug ("cast_rules from={%s} to={%s}", |
| from.get_ty ()->debug_str ().c_str (), |
| to.get_ty ()->debug_str ().c_str ()); |
| |
| switch (from.get_ty ()->get_kind ()) |
| { |
| case TyTy::TypeKind::INFER: { |
| TyTy::InferType *from_infer |
| = static_cast<TyTy::InferType *> (from.get_ty ()); |
| switch (from_infer->get_infer_kind ()) |
| { |
| case TyTy::InferType::InferTypeKind::GENERAL: |
| return TypeCoercionRules::CoercionResult{{}, |
| to.get_ty ()->clone ()}; |
| |
| case TyTy::InferType::InferTypeKind::INTEGRAL: |
| switch (to.get_ty ()->get_kind ()) |
| { |
| case TyTy::TypeKind::CHAR: |
| case TyTy::TypeKind::BOOL: |
| case TyTy::TypeKind::USIZE: |
| case TyTy::TypeKind::ISIZE: |
| case TyTy::TypeKind::UINT: |
| case TyTy::TypeKind::INT: |
| case TyTy::TypeKind::POINTER: |
| return TypeCoercionRules::CoercionResult{ |
| {}, to.get_ty ()->clone ()}; |
| |
| case TyTy::TypeKind::INFER: { |
| TyTy::InferType *to_infer |
| = static_cast<TyTy::InferType *> (to.get_ty ()); |
| |
| switch (to_infer->get_infer_kind ()) |
| { |
| case TyTy::InferType::InferTypeKind::GENERAL: |
| case TyTy::InferType::InferTypeKind::INTEGRAL: |
| return TypeCoercionRules::CoercionResult{ |
| {}, to.get_ty ()->clone ()}; |
| |
| default: |
| return TypeCoercionRules::CoercionResult::get_error (); |
| } |
| } |
| break; |
| |
| default: |
| return TypeCoercionRules::CoercionResult::get_error (); |
| } |
| break; |
| |
| case TyTy::InferType::InferTypeKind::FLOAT: |
| switch (to.get_ty ()->get_kind ()) |
| { |
| case TyTy::TypeKind::USIZE: |
| case TyTy::TypeKind::ISIZE: |
| case TyTy::TypeKind::UINT: |
| case TyTy::TypeKind::INT: |
| return TypeCoercionRules::CoercionResult{ |
| {}, to.get_ty ()->clone ()}; |
| |
| case TyTy::TypeKind::INFER: { |
| TyTy::InferType *to_infer |
| = static_cast<TyTy::InferType *> (to.get_ty ()); |
| |
| switch (to_infer->get_infer_kind ()) |
| { |
| case TyTy::InferType::InferTypeKind::GENERAL: |
| case TyTy::InferType::InferTypeKind::FLOAT: |
| return TypeCoercionRules::CoercionResult{ |
| {}, to.get_ty ()->clone ()}; |
| |
| default: |
| return TypeCoercionRules::CoercionResult::get_error (); |
| } |
| } |
| break; |
| |
| default: |
| return TypeCoercionRules::CoercionResult::get_error (); |
| } |
| break; |
| } |
| } |
| break; |
| |
| case TyTy::TypeKind::BOOL: |
| switch (to.get_ty ()->get_kind ()) |
| { |
| case TyTy::TypeKind::INFER: |
| case TyTy::TypeKind::USIZE: |
| case TyTy::TypeKind::ISIZE: |
| case TyTy::TypeKind::UINT: |
| case TyTy::TypeKind::INT: |
| return TypeCoercionRules::CoercionResult{{}, to.get_ty ()->clone ()}; |
| |
| default: |
| return TypeCoercionRules::CoercionResult::get_error (); |
| } |
| break; |
| |
| case TyTy::TypeKind::CHAR: |
| case TyTy::TypeKind::USIZE: |
| case TyTy::TypeKind::ISIZE: |
| case TyTy::TypeKind::UINT: |
| case TyTy::TypeKind::INT: |
| switch (to.get_ty ()->get_kind ()) |
| { |
| case TyTy::TypeKind::CHAR: { |
| // only u8 and char |
| bool was_uint = from.get_ty ()->get_kind () == TyTy::TypeKind::UINT; |
| bool was_u8 = was_uint |
| && (static_cast<TyTy::UintType *> (from.get_ty ()) |
| ->get_uint_kind () |
| == TyTy::UintType::UintKind::U8); |
| if (was_u8) |
| return TypeCoercionRules::CoercionResult{{}, |
| to.get_ty ()->clone ()}; |
| } |
| break; |
| |
| case TyTy::TypeKind::INFER: |
| case TyTy::TypeKind::USIZE: |
| case TyTy::TypeKind::ISIZE: |
| case TyTy::TypeKind::UINT: |
| case TyTy::TypeKind::INT: |
| return TypeCoercionRules::CoercionResult{{}, to.get_ty ()->clone ()}; |
| |
| default: |
| return TypeCoercionRules::CoercionResult::get_error (); |
| } |
| break; |
| |
| case TyTy::TypeKind::FLOAT: |
| switch (to.get_ty ()->get_kind ()) |
| { |
| case TyTy::TypeKind::FLOAT: |
| return TypeCoercionRules::CoercionResult{{}, to.get_ty ()->clone ()}; |
| |
| case TyTy::TypeKind::INFER: { |
| TyTy::InferType *to_infer |
| = static_cast<TyTy::InferType *> (to.get_ty ()); |
| |
| switch (to_infer->get_infer_kind ()) |
| { |
| case TyTy::InferType::InferTypeKind::GENERAL: |
| case TyTy::InferType::InferTypeKind::FLOAT: |
| return TypeCoercionRules::CoercionResult{ |
| {}, to.get_ty ()->clone ()}; |
| |
| default: |
| return TypeCoercionRules::CoercionResult::get_error (); |
| } |
| } |
| break; |
| |
| default: |
| return TypeCoercionRules::CoercionResult::get_error (); |
| } |
| break; |
| |
| case TyTy::TypeKind::REF: |
| case TyTy::TypeKind::POINTER: |
| switch (to.get_ty ()->get_kind ()) |
| { |
| case TyTy::TypeKind::REF: |
| case TyTy::TypeKind::POINTER: |
| return check_ptr_ptr_cast (); |
| |
| // FIXME can you cast a pointer to a integral type? |
| |
| default: |
| return TypeCoercionRules::CoercionResult::get_error (); |
| } |
| break; |
| |
| default: |
| return TypeCoercionRules::CoercionResult::get_error (); |
| } |
| |
| return TypeCoercionRules::CoercionResult::get_error (); |
| } |
| |
| TypeCoercionRules::CoercionResult |
| TypeCastRules::check_ptr_ptr_cast () |
| { |
| rust_debug ("check_ptr_ptr_cast from={%s} to={%s}", |
| from.get_ty ()->debug_str ().c_str (), |
| to.get_ty ()->debug_str ().c_str ()); |
| |
| bool from_is_ref = from.get_ty ()->get_kind () == TyTy::TypeKind::REF; |
| bool to_is_ref = to.get_ty ()->get_kind () == TyTy::TypeKind::REF; |
| bool from_is_ptr = from.get_ty ()->get_kind () == TyTy::TypeKind::POINTER; |
| bool to_is_ptr = to.get_ty ()->get_kind () == TyTy::TypeKind::POINTER; |
| |
| if (from_is_ptr && to_is_ptr) |
| { |
| // mutability is ignored here as all pointer usage requires unsafe |
| return TypeCoercionRules::CoercionResult{{}, to.get_ty ()->clone ()}; |
| } |
| else if (from_is_ref && to_is_ref) |
| { |
| // mutability must be coercedable |
| TyTy::ReferenceType &f |
| = static_cast<TyTy::ReferenceType &> (*from.get_ty ()); |
| TyTy::ReferenceType &t |
| = static_cast<TyTy::ReferenceType &> (*to.get_ty ()); |
| |
| if (TypeCoercionRules::coerceable_mutability (f.mutability (), |
| t.mutability ())) |
| { |
| return TypeCoercionRules::CoercionResult{{}, to.get_ty ()->clone ()}; |
| } |
| } |
| |
| return TypeCoercionRules::CoercionResult::get_error (); |
| } |
| |
| void |
| TypeCastRules::emit_cast_error () const |
| { |
| // error[E0604] |
| RichLocation r (locus); |
| r.add_range (from.get_locus ()); |
| r.add_range (to.get_locus ()); |
| rust_error_at (r, "invalid cast %<%s%> to %<%s%>", |
| from.get_ty ()->get_name ().c_str (), |
| to.get_ty ()->get_name ().c_str ()); |
| } |
| |
| } // namespace Resolver |
| } // namespace Rust |