diff options
Diffstat (limited to 'compiler/rustc_const_eval/src/interpret/operand.rs')
| -rw-r--r-- | compiler/rustc_const_eval/src/interpret/operand.rs | 128 |
1 files changed, 95 insertions, 33 deletions
diff --git a/compiler/rustc_const_eval/src/interpret/operand.rs b/compiler/rustc_const_eval/src/interpret/operand.rs index e6d0a73c521..be39e63ab4f 100644 --- a/compiler/rustc_const_eval/src/interpret/operand.rs +++ b/compiler/rustc_const_eval/src/interpret/operand.rs @@ -1,6 +1,8 @@ //! Functions concerning immediate values and operands, and reading from operands. //! All high-level functions to read from memory work on operands as sources. +use std::assert_matches::assert_matches; + use either::{Either, Left, Right}; use rustc_hir::def::Namespace; @@ -14,7 +16,7 @@ use rustc_target::abi::{self, Abi, Align, HasDataLayout, Size}; use super::{ alloc_range, from_known_layout, mir_assign_valid_types, AllocId, ConstValue, Frame, GlobalId, InterpCx, InterpResult, MPlaceTy, Machine, MemPlace, MemPlaceMeta, PlaceTy, Pointer, - Provenance, Scalar, + Projectable, Provenance, Scalar, }; /// An `Immediate` represents a single immediate self-contained Rust value. @@ -199,6 +201,20 @@ impl<'tcx, Prov: Provenance> From<ImmTy<'tcx, Prov>> for OpTy<'tcx, Prov> { } } +impl<'tcx, Prov: Provenance> From<&'_ ImmTy<'tcx, Prov>> for OpTy<'tcx, Prov> { + #[inline(always)] + fn from(val: &ImmTy<'tcx, Prov>) -> Self { + OpTy { op: Operand::Immediate(val.imm), layout: val.layout, align: None } + } +} + +impl<'tcx, Prov: Provenance> From<&'_ mut ImmTy<'tcx, Prov>> for OpTy<'tcx, Prov> { + #[inline(always)] + fn from(val: &mut ImmTy<'tcx, Prov>) -> Self { + OpTy { op: Operand::Immediate(val.imm), layout: val.layout, align: None } + } +} + impl<'tcx, Prov: Provenance> ImmTy<'tcx, Prov> { #[inline] pub fn from_scalar(val: Scalar<Prov>, layout: TyAndLayout<'tcx>) -> Self { @@ -243,12 +259,8 @@ impl<'tcx, Prov: Provenance> ImmTy<'tcx, Prov> { /// Compute the "sub-immediate" that is located within the `base` at the given offset with the /// given layout. - pub(super) fn offset( - &self, - offset: Size, - layout: TyAndLayout<'tcx>, - cx: &impl HasDataLayout, - ) -> Self { + // Not called `offset` to avoid confusion with the trait method. + fn offset_(&self, offset: Size, layout: TyAndLayout<'tcx>, cx: &impl HasDataLayout) -> Self { // This makes several assumptions about what layouts we will encounter; we match what // codegen does as good as we can (see `extract_field` in `rustc_codegen_ssa/src/mir/operand.rs`). let inner_val: Immediate<_> = match (**self, self.layout.abi) { @@ -256,14 +268,28 @@ impl<'tcx, Prov: Provenance> ImmTy<'tcx, Prov> { (Immediate::Uninit, _) => Immediate::Uninit, // the field contains no information, can be left uninit _ if layout.is_zst() => Immediate::Uninit, + // some fieldless enum variants can have non-zero size but still `Aggregate` ABI... try + // to detect those here and also give them no data + _ if matches!(layout.abi, Abi::Aggregate { .. }) + && matches!(&layout.fields, abi::FieldsShape::Arbitrary { offsets, .. } if offsets.len() == 0) => + { + Immediate::Uninit + } // the field covers the entire type _ if layout.size == self.layout.size => { - assert!(match (self.layout.abi, layout.abi) { - (Abi::Scalar(..), Abi::Scalar(..)) => true, - (Abi::ScalarPair(..), Abi::ScalarPair(..)) => true, - _ => false, - }); - assert!(offset.bytes() == 0); + assert_eq!(offset.bytes(), 0); + assert!( + match (self.layout.abi, layout.abi) { + (Abi::Scalar(..), Abi::Scalar(..)) => true, + (Abi::ScalarPair(..), Abi::ScalarPair(..)) => true, + _ => false, + }, + "cannot project into {} immediate with equally-sized field {}\nouter ABI: {:#?}\nfield ABI: {:#?}", + self.layout.ty, + layout.ty, + self.layout.abi, + layout.abi, + ); **self } // extract fields from types with `ScalarPair` ABI @@ -286,8 +312,42 @@ impl<'tcx, Prov: Provenance> ImmTy<'tcx, Prov> { } } +impl<'mir, 'tcx: 'mir, Prov: Provenance> Projectable<'mir, 'tcx, Prov> for ImmTy<'tcx, Prov> { + #[inline(always)] + fn layout(&self) -> TyAndLayout<'tcx> { + self.layout + } + + fn meta<M: Machine<'mir, 'tcx, Provenance = Prov>>( + &self, + _ecx: &InterpCx<'mir, 'tcx, M>, + ) -> InterpResult<'tcx, MemPlaceMeta<M::Provenance>> { + assert!(self.layout.is_sized()); // unsized ImmTy can only exist temporarily and should never reach this here + Ok(MemPlaceMeta::None) + } + + fn offset_with_meta( + &self, + offset: Size, + meta: MemPlaceMeta<Prov>, + layout: TyAndLayout<'tcx>, + cx: &impl HasDataLayout, + ) -> InterpResult<'tcx, Self> { + assert_matches!(meta, MemPlaceMeta::None); // we can't store this anywhere anyway + Ok(self.offset_(offset, layout, cx)) + } + + fn to_op<M: Machine<'mir, 'tcx, Provenance = Prov>>( + &self, + _ecx: &InterpCx<'mir, 'tcx, M>, + ) -> InterpResult<'tcx, OpTy<'tcx, M::Provenance>> { + Ok(self.into()) + } +} + impl<'tcx, Prov: Provenance> OpTy<'tcx, Prov> { - pub(super) fn meta(&self) -> InterpResult<'tcx, MemPlaceMeta<Prov>> { + // Provided as inherent method since it doesn't need the `ecx` of `Projectable::meta`. + pub fn meta(&self) -> InterpResult<'tcx, MemPlaceMeta<Prov>> { Ok(if self.layout.is_unsized() { if matches!(self.op, Operand::Immediate(_)) { // Unsized immediate OpTy cannot occur. We create a MemPlace for all unsized locals during argument passing. @@ -300,15 +360,24 @@ impl<'tcx, Prov: Provenance> OpTy<'tcx, Prov> { MemPlaceMeta::None }) } +} - pub fn len(&self, cx: &impl HasDataLayout) -> InterpResult<'tcx, u64> { - self.meta()?.len(self.layout, cx) +impl<'mir, 'tcx: 'mir, Prov: Provenance + 'static> Projectable<'mir, 'tcx, Prov> + for OpTy<'tcx, Prov> +{ + #[inline(always)] + fn layout(&self) -> TyAndLayout<'tcx> { + self.layout } - /// Offset the operand in memory (if possible) and change its metadata. - /// - /// This can go wrong very easily if you give the wrong layout for the new place! - pub(super) fn offset_with_meta( + fn meta<M: Machine<'mir, 'tcx, Provenance = Prov>>( + &self, + _ecx: &InterpCx<'mir, 'tcx, M>, + ) -> InterpResult<'tcx, MemPlaceMeta<M::Provenance>> { + self.meta() + } + + fn offset_with_meta( &self, offset: Size, meta: MemPlaceMeta<Prov>, @@ -320,22 +389,16 @@ impl<'tcx, Prov: Provenance> OpTy<'tcx, Prov> { Right(imm) => { assert!(!meta.has_meta()); // no place to store metadata here // Every part of an uninit is uninit. - Ok(imm.offset(offset, layout, cx).into()) + Ok(imm.offset(offset, layout, cx)?.into()) } } } - /// Offset the operand in memory (if possible). - /// - /// This can go wrong very easily if you give the wrong layout for the new place! - pub fn offset( + fn to_op<M: Machine<'mir, 'tcx, Provenance = Prov>>( &self, - offset: Size, - layout: TyAndLayout<'tcx>, - cx: &impl HasDataLayout, - ) -> InterpResult<'tcx, Self> { - assert!(layout.is_sized()); - self.offset_with_meta(offset, MemPlaceMeta::None, layout, cx) + _ecx: &InterpCx<'mir, 'tcx, M>, + ) -> InterpResult<'tcx, OpTy<'tcx, M::Provenance>> { + Ok(self.clone()) } } @@ -525,7 +588,6 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> { /// Every place can be read from, so we can turn them into an operand. /// This will definitely return `Indirect` if the place is a `Ptr`, i.e., this /// will never actually read from memory. - #[inline(always)] pub fn place_to_op( &self, place: &PlaceTy<'tcx, M::Provenance>, @@ -564,7 +626,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> { let mut op = self.local_to_op(self.frame(), mir_place.local, layout)?; // Using `try_fold` turned out to be bad for performance, hence the loop. for elem in mir_place.projection.iter() { - op = self.operand_projection(&op, elem)? + op = self.project(&op, elem)? } trace!("eval_place_to_op: got {:?}", *op); |