bendns' repos / rust-analyzer
Unnamed repository; edit this file 'description' to name the repository.
Diffstat (limited to 'crates/hir-ty/src/mir/lower.rs')
-rw-r--r--crates/hir-ty/src/mir/lower.rs79
1 files changed, 36 insertions, 43 deletions
diff --git a/crates/hir-ty/src/mir/lower.rs b/crates/hir-ty/src/mir/lower.rs
index 9e23550451..9cee494bbe 100644
--- a/crates/hir-ty/src/mir/lower.rs
+++ b/crates/hir-ty/src/mir/lower.rs
@@ -31,7 +31,7 @@ use crate::{
display::HirDisplay,
error_lifetime,
generics::generics,
- infer::{CaptureKind, CapturedItem, TypeMismatch},
+ infer::{cast::CastTy, unify::InferenceTable, CaptureKind, CapturedItem, TypeMismatch},
inhabitedness::is_ty_uninhabited_from,
layout::LayoutError,
mapping::ToChalk,
@@ -362,7 +362,7 @@ impl<'ctx> MirLowerCtx<'ctx> {
current,
place,
Rvalue::Cast(
- CastKind::Pointer(*cast),
+ CastKind::PointerCoercion(*cast),
Operand::Copy(p),
last.target.clone(),
),
@@ -898,14 +898,26 @@ impl<'ctx> MirLowerCtx<'ctx> {
let Some((it, current)) = self.lower_expr_to_some_operand(*expr, current)? else {
return Ok(None);
};
- let source_ty = self.infer[*expr].clone();
- let target_ty = self.infer[expr_id].clone();
- self.push_assignment(
- current,
- place,
- Rvalue::Cast(cast_kind(&source_ty, &target_ty)?, it, target_ty),
- expr_id.into(),
- );
+ // Since we don't have THIR, this is the "zipped" version of [rustc's HIR lowering](https://github.com/rust-lang/rust/blob/e71f9529121ca8f687e4b725e3c9adc3f1ebab4d/compiler/rustc_mir_build/src/thir/cx/expr.rs#L165-L178)
+ // and [THIR lowering as RValue](https://github.com/rust-lang/rust/blob/a4601859ae3875732797873612d424976d9e3dd0/compiler/rustc_mir_build/src/build/expr/as_rvalue.rs#L193-L313)
+ let rvalue = if self.infer.coercion_casts.contains(expr) {
+ Rvalue::Use(it)
+ } else {
+ let source_ty = self.infer[*expr].clone();
+ let target_ty = self.infer[expr_id].clone();
+ let cast_kind = if source_ty.as_reference().is_some() {
+ CastKind::PointerCoercion(PointerCast::ArrayToPointer)
+ } else {
+ let mut table = InferenceTable::new(
+ self.db,
+ self.db.trait_environment_for_body(self.owner),
+ );
+ cast_kind(&mut table, &source_ty, &target_ty)?
+ };
+
+ Rvalue::Cast(cast_kind, it, target_ty)
+ };
+ self.push_assignment(current, place, rvalue, expr_id.into());
Ok(Some(current))
}
Expr::Ref { expr, rawness: _, mutability } => {
@@ -2005,40 +2017,21 @@ impl<'ctx> MirLowerCtx<'ctx> {
}
}
-fn cast_kind(source_ty: &Ty, target_ty: &Ty) -> Result<CastKind> {
- Ok(match (source_ty.kind(Interner), target_ty.kind(Interner)) {
- (TyKind::FnDef(..), TyKind::Function(_)) => CastKind::Pointer(PointerCast::ReifyFnPointer),
- (TyKind::Scalar(s), TyKind::Scalar(t)) => match (s, t) {
- (chalk_ir::Scalar::Float(_), chalk_ir::Scalar::Float(_)) => CastKind::FloatToFloat,
- (chalk_ir::Scalar::Float(_), _) => CastKind::FloatToInt,
- (_, chalk_ir::Scalar::Float(_)) => CastKind::IntToFloat,
- (_, _) => CastKind::IntToInt,
- },
- (TyKind::Scalar(_), TyKind::Raw(..)) => CastKind::PointerFromExposedAddress,
- (TyKind::Raw(..), TyKind::Scalar(_)) => CastKind::PointerExposeAddress,
- (TyKind::Raw(_, a) | TyKind::Ref(_, _, a), TyKind::Raw(_, b) | TyKind::Ref(_, _, b)) => {
- CastKind::Pointer(if a == b {
- PointerCast::MutToConstPointer
- } else if matches!(b.kind(Interner), TyKind::Slice(_))
- && matches!(a.kind(Interner), TyKind::Array(_, _))
- || matches!(b.kind(Interner), TyKind::Dyn(_))
- {
- PointerCast::Unsize
- } else if matches!(a.kind(Interner), TyKind::Slice(s) if s == b) {
- PointerCast::ArrayToPointer
- } else {
- // cast between two sized pointer, like *const i32 to *const i8, or two unsized pointer, like
- // slice to slice, slice to str, ... . These are no-ops (even in the unsized case, no metadata
- // will be touched) but there is no specific variant
- // for it in `PointerCast` so we use `MutToConstPointer`
- PointerCast::MutToConstPointer
- })
- }
- // Enum to int casts
- (TyKind::Scalar(_), TyKind::Adt(..)) | (TyKind::Adt(..), TyKind::Scalar(_)) => {
- CastKind::IntToInt
+fn cast_kind(table: &mut InferenceTable<'_>, source_ty: &Ty, target_ty: &Ty) -> Result<CastKind> {
+ let from = CastTy::from_ty(table, source_ty);
+ let cast = CastTy::from_ty(table, target_ty);
+ Ok(match (from, cast) {
+ (Some(CastTy::Ptr(..) | CastTy::FnPtr), Some(CastTy::Int(_))) => {
+ CastKind::PointerExposeAddress
}
- (a, b) => not_supported!("Unknown cast between {a:?} and {b:?}"),
+ (Some(CastTy::Int(_)), Some(CastTy::Ptr(..))) => CastKind::PointerFromExposedAddress,
+ (Some(CastTy::Int(_)), Some(CastTy::Int(_))) => CastKind::IntToInt,
+ (Some(CastTy::FnPtr), Some(CastTy::Ptr(..))) => CastKind::FnPtrToPtr,
+ (Some(CastTy::Float), Some(CastTy::Int(_))) => CastKind::FloatToInt,
+ (Some(CastTy::Int(_)), Some(CastTy::Float)) => CastKind::IntToFloat,
+ (Some(CastTy::Float), Some(CastTy::Float)) => CastKind::FloatToFloat,
+ (Some(CastTy::Ptr(..)), Some(CastTy::Ptr(..))) => CastKind::PtrToPtr,
+ _ => not_supported!("Unknown cast between {source_ty:?} and {target_ty:?}"),
})
}