diff --git a/src/librustc_mir/interpret/eval_context.rs b/src/librustc_mir/interpret/eval_context.rs index 9aa42e107dc..ce098f583d0 100644 --- a/src/librustc_mir/interpret/eval_context.rs +++ b/src/librustc_mir/interpret/eval_context.rs @@ -210,6 +210,48 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> LayoutOf for InterpCx<'mir, 'tcx, M> { } } +/// Test if it is valid for a MIR assignment to assign `src`-typed place to `dest`-typed value. +/// This test should be symmetric, as it is primarily about layout compatibility. +pub(super) fn mir_assign_valid_types<'tcx>(src: Ty<'tcx>, dest: Ty<'tcx>) -> bool { + src == dest + || match (&src.kind, &dest.kind) { + (ty::Ref(_, src_pointee, _), ty::Ref(_, dest_pointee, _)) => { + // After optimizations, there can be assignments that change reference mutability. + // This does not affect reference layout, so that is fine. + src_pointee == dest_pointee + } + (ty::FnPtr(_), ty::FnPtr(_)) => { + // All function pointers have equal layout, and thus can be assigned. + true + } + _ => false, + } +} + +/// Use the already known layout if given (but sanity check in debug mode), +/// or compute the layout. +#[cfg_attr(not(debug_assertions), inline(always))] +pub(super) fn from_known_layout<'tcx>( + known_layout: Option>, + compute: impl FnOnce() -> InterpResult<'tcx, TyAndLayout<'tcx>>, +) -> InterpResult<'tcx, TyAndLayout<'tcx>> { + match known_layout { + None => compute(), + Some(known_layout) => { + if cfg!(debug_assertions) { + let check_layout = compute()?; + assert!( + mir_assign_valid_types(check_layout.ty, known_layout.ty), + "expected type differs from actual type.\nexpected: {:?}\nactual: {:?}", + known_layout.ty, + check_layout.ty, + ); + } + Ok(known_layout) + } + } +} + impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> { pub fn new( tcx: TyCtxtAt<'tcx>, @@ -377,7 +419,7 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> { // have to support that case (mostly by skipping all caching). match frame.locals.get(local).and_then(|state| state.layout.get()) { None => { - let layout = crate::interpret::operand::from_known_layout(layout, || { + let layout = from_known_layout(layout, || { let local_ty = frame.body.local_decls[local].ty; let local_ty = self.subst_from_frame_and_normalize_erasing_regions(frame, local_ty); diff --git a/src/librustc_mir/interpret/mod.rs b/src/librustc_mir/interpret/mod.rs index 4e30da82907..fb59a177b97 100644 --- a/src/librustc_mir/interpret/mod.rs +++ b/src/librustc_mir/interpret/mod.rs @@ -18,19 +18,13 @@ mod visitor; pub use rustc_middle::mir::interpret::*; // have all the `interpret` symbols in one place: here pub use self::eval_context::{Frame, InterpCx, LocalState, LocalValue, StackPopCleanup}; - -pub use self::place::{MPlaceTy, MemPlace, MemPlaceMeta, Place, PlaceTy}; - -pub use self::memory::{AllocCheck, FnVal, Memory, MemoryKind}; - +pub use self::intern::{intern_const_alloc_recursive, InternKind}; pub use self::machine::{AllocMap, Machine, MayLeak, StackPopJump}; - -pub use self::operand::{ImmTy, Immediate, OpTy, Operand, ScalarMaybeUndef}; - +pub use self::memory::{AllocCheck, FnVal, Memory, MemoryKind}; +pub use self::operand::{ImmTy, Immediate, OpTy, Operand}; +pub use self::place::{MPlaceTy, MemPlace, MemPlaceMeta, Place, PlaceTy}; +pub use self::validity::RefTracking; pub use self::visitor::{MutValueVisitor, ValueVisitor}; -pub use self::validity::RefTracking; - -pub use self::intern::{intern_const_alloc_recursive, InternKind}; - crate use self::intrinsics::eval_nullary_intrinsic; +use eval_context::{from_known_layout, mir_assign_valid_types}; diff --git a/src/librustc_mir/interpret/operand.rs b/src/librustc_mir/interpret/operand.rs index 999d0d26ab3..12595e4e4d9 100644 --- a/src/librustc_mir/interpret/operand.rs +++ b/src/librustc_mir/interpret/operand.rs @@ -2,21 +2,21 @@ //! All high-level functions to read from memory work on operands as sources. use std::convert::TryFrom; +use std::fmt::Write; -use super::{InterpCx, MPlaceTy, Machine, MemPlace, Place, PlaceTy}; use rustc_hir::def::Namespace; use rustc_macros::HashStable; -pub use rustc_middle::mir::interpret::ScalarMaybeUndef; -use rustc_middle::mir::interpret::{ - sign_extend, truncate, AllocId, ConstValue, GlobalId, InterpResult, Pointer, Scalar, -}; use rustc_middle::ty::layout::{IntegerExt, PrimitiveExt, TyAndLayout}; use rustc_middle::ty::print::{FmtPrinter, PrettyPrinter, Printer}; use rustc_middle::ty::Ty; use rustc_middle::{mir, ty}; use rustc_target::abi::{Abi, DiscriminantKind, HasDataLayout, Integer, LayoutOf, Size}; use rustc_target::abi::{VariantIdx, Variants}; -use std::fmt::Write; + +use super::{ + from_known_layout, sign_extend, truncate, AllocId, ConstValue, GlobalId, InterpCx, + InterpResult, MPlaceTy, Machine, MemPlace, Place, PlaceTy, Pointer, Scalar, ScalarMaybeUndef, +}; /// An `Immediate` represents a single immediate self-contained Rust value. /// @@ -203,29 +203,6 @@ impl<'tcx, Tag: Copy> ImmTy<'tcx, Tag> { } } -// Use the existing layout if given (but sanity check in debug mode), -// or compute the layout. -#[inline(always)] -pub(super) fn from_known_layout<'tcx>( - layout: Option>, - compute: impl FnOnce() -> InterpResult<'tcx, TyAndLayout<'tcx>>, -) -> InterpResult<'tcx, TyAndLayout<'tcx>> { - match layout { - None => compute(), - Some(layout) => { - if cfg!(debug_assertions) { - let layout2 = compute()?; - assert_eq!( - layout.layout, layout2.layout, - "mismatch in layout of supposedly equal-layout types {:?} and {:?}", - layout.ty, layout2.ty - ); - } - Ok(layout) - } - } -} - impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> { /// Normalice `place.ptr` to a `Pointer` if this is a place and not a ZST. /// Can be helpful to avoid lots of `force_ptr` calls later, if this place is used a lot. diff --git a/src/librustc_mir/interpret/place.rs b/src/librustc_mir/interpret/place.rs index 5d4976c09bb..c9999ef7c95 100644 --- a/src/librustc_mir/interpret/place.rs +++ b/src/librustc_mir/interpret/place.rs @@ -7,16 +7,15 @@ use std::hash::Hash; use rustc_macros::HashStable; use rustc_middle::mir; -use rustc_middle::mir::interpret::truncate; use rustc_middle::ty::layout::{PrimitiveExt, TyAndLayout}; use rustc_middle::ty::{self, Ty}; use rustc_target::abi::{Abi, Align, DiscriminantKind, FieldsShape}; use rustc_target::abi::{HasDataLayout, LayoutOf, Size, VariantIdx, Variants}; use super::{ - AllocId, AllocMap, Allocation, AllocationExtra, ImmTy, Immediate, InterpCx, InterpResult, - LocalValue, Machine, MemoryKind, OpTy, Operand, Pointer, PointerArithmetic, RawConst, Scalar, - ScalarMaybeUndef, + mir_assign_valid_types, truncate, AllocId, AllocMap, Allocation, AllocationExtra, ImmTy, + Immediate, InterpCx, InterpResult, LocalValue, Machine, MemoryKind, OpTy, Operand, Pointer, + PointerArithmetic, RawConst, Scalar, ScalarMaybeUndef, }; #[derive(Copy, Clone, Debug, Hash, PartialEq, Eq, HashStable)] @@ -283,23 +282,6 @@ impl<'tcx, Tag: ::std::fmt::Debug> PlaceTy<'tcx, Tag> { } } -/// Test if it is valid for a MIR assignment to assign `src`-typed place to `dest`-typed value. -fn mir_assign_valid_types<'tcx>(src: Ty<'tcx>, dest: Ty<'tcx>) -> bool { - src == dest - || match (&src.kind, &dest.kind) { - (ty::Ref(_, src_pointee, _), ty::Ref(_, dest_pointee, _)) => { - // After optimizations, there can be assignments that change reference mutability. - // This does not affect reference layout, so that is fine. - src_pointee == dest_pointee - } - (ty::FnPtr(_), ty::FnPtr(_)) => { - // All function pointers have equal layout, and thus can be assigned. - true - } - _ => false, - } -} - // separating the pointer tag for `impl Trait`, see https://github.com/rust-lang/rust/issues/54385 impl<'mir, 'tcx, Tag, M> InterpCx<'mir, 'tcx, M> where