diff options
Diffstat (limited to 'compiler/rustc_const_eval/src/interpret')
| -rw-r--r-- | compiler/rustc_const_eval/src/interpret/intrinsics.rs | 99 | ||||
| -rw-r--r-- | compiler/rustc_const_eval/src/interpret/memory.rs | 6 | ||||
| -rw-r--r-- | compiler/rustc_const_eval/src/interpret/stack.rs | 7 |
3 files changed, 63 insertions, 49 deletions
diff --git a/compiler/rustc_const_eval/src/interpret/intrinsics.rs b/compiler/rustc_const_eval/src/interpret/intrinsics.rs index 22d29eda913..e24a355891d 100644 --- a/compiler/rustc_const_eval/src/interpret/intrinsics.rs +++ b/compiler/rustc_const_eval/src/interpret/intrinsics.rs @@ -4,8 +4,9 @@ use std::assert_matches::assert_matches; -use rustc_abi::{FieldIdx, Size}; +use rustc_abi::{FieldIdx, HasDataLayout, Size}; use rustc_apfloat::ieee::{Double, Half, Quad, Single}; +use rustc_middle::mir::interpret::{read_target_uint, write_target_uint}; use rustc_middle::mir::{self, BinOp, ConstValue, NonDivergingIntrinsic}; use rustc_middle::ty::layout::TyAndLayout; use rustc_middle::ty::{Ty, TyCtxt}; @@ -30,7 +31,7 @@ pub(crate) fn alloc_type_name<'tcx>(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>) -> ConstAll } impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> { /// Generates a value of `TypeId` for `ty` in-place. - pub(crate) fn write_type_id( + fn write_type_id( &mut self, ty: Ty<'tcx>, dest: &PlaceTy<'tcx, M::Provenance>, @@ -48,8 +49,8 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> { // Here we rely on `TypeId` being a newtype around an array of pointers, so we // first project to its only field and then the array elements. let alloc_id = tcx.reserve_and_set_type_id_alloc(ty); - let first = self.project_field(dest, FieldIdx::ZERO)?; - let mut elem_iter = self.project_array_fields(&first)?; + let arr = self.project_field(dest, FieldIdx::ZERO)?; + let mut elem_iter = self.project_array_fields(&arr)?; while let Some((_, elem)) = elem_iter.next(self)? { // Decorate this part of the hash with provenance; leave the integer part unchanged. let hash_fragment = self.read_scalar(&elem)?.to_target_usize(&tcx)?; @@ -61,6 +62,52 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> { interp_ok(()) } + /// Read a value of type `TypeId`, returning the type it represents. + pub(crate) fn read_type_id( + &self, + op: &OpTy<'tcx, M::Provenance>, + ) -> InterpResult<'tcx, Ty<'tcx>> { + // `TypeId` is a newtype around an array of pointers. All pointers must have the same + // provenance, and that provenance represents the type. + let ptr_size = self.pointer_size().bytes_usize(); + let arr = self.project_field(op, FieldIdx::ZERO)?; + + let mut ty_and_hash = None; + let mut elem_iter = self.project_array_fields(&arr)?; + while let Some((idx, elem)) = elem_iter.next(self)? { + let elem = self.read_pointer(&elem)?; + let (elem_ty, elem_hash) = self.get_ptr_type_id(elem)?; + // If this is the first element, remember the type and its hash. + // If this is not the first element, ensure it is consistent with the previous ones. + let full_hash = match ty_and_hash { + None => { + let hash = self.tcx.type_id_hash(elem_ty).as_u128(); + let mut hash_bytes = [0u8; 16]; + write_target_uint(self.data_layout().endian, &mut hash_bytes, hash).unwrap(); + ty_and_hash = Some((elem_ty, hash_bytes)); + hash_bytes + } + Some((ty, hash_bytes)) => { + if ty != elem_ty { + throw_ub_format!( + "invalid `TypeId` value: not all bytes carry the same type id metadata" + ); + } + hash_bytes + } + }; + // Ensure the elem_hash matches the corresponding part of the full hash. + let hash_frag = &full_hash[(idx as usize) * ptr_size..][..ptr_size]; + if read_target_uint(self.data_layout().endian, hash_frag).unwrap() != elem_hash.into() { + throw_ub_format!( + "invalid `TypeId` value: the hash does not match the type id metadata" + ); + } + } + + interp_ok(ty_and_hash.unwrap().0) + } + /// Returns `true` if emulation happened. /// Here we implement the intrinsics that are common to all Miri instances; individual machines can add their own /// intrinsic handling. @@ -97,47 +144,9 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> { self.write_type_id(tp_ty, dest)?; } sym::type_id_eq => { - // Both operands are `TypeId`, which is a newtype around an array of pointers. - // Project until we have the array elements. - let a_fields = self.project_field(&args[0], FieldIdx::ZERO)?; - let b_fields = self.project_field(&args[1], FieldIdx::ZERO)?; - - let mut a_fields = self.project_array_fields(&a_fields)?; - let mut b_fields = self.project_array_fields(&b_fields)?; - - let mut provenance_a = None; - let mut provenance_b = None; - let mut provenance_matches = true; - - while let Some((i, a)) = a_fields.next(self)? { - let (_, b) = b_fields.next(self)?.unwrap(); - - let a = self.deref_pointer(&a)?; - let (a, offset_a) = self.get_ptr_type_id(a.ptr())?; - - let b = self.deref_pointer(&b)?; - let (b, offset_b) = self.get_ptr_type_id(b.ptr())?; - - if *provenance_a.get_or_insert(a) != a { - throw_ub_format!( - "type_id_eq: the first TypeId argument is invalid, the provenance of chunk {i} does not match the first chunk's" - ) - } - if *provenance_b.get_or_insert(b) != b { - throw_ub_format!( - "type_id_eq: the second TypeId argument is invalid, the provenance of chunk {i} does not match the first chunk's" - ) - } - provenance_matches &= a == b; - - if offset_a != offset_b && provenance_matches { - throw_ub_format!( - "type_id_eq: one of the TypeId arguments is invalid, chunk {i} of the hash does not match the type it represents" - ) - } - } - - self.write_scalar(Scalar::from_bool(provenance_matches), dest)?; + let a_ty = self.read_type_id(&args[0])?; + let b_ty = self.read_type_id(&args[1])?; + self.write_scalar(Scalar::from_bool(a_ty == b_ty), dest)?; } sym::variant_count => { let tp_ty = instance.args.type_at(0); diff --git a/compiler/rustc_const_eval/src/interpret/memory.rs b/compiler/rustc_const_eval/src/interpret/memory.rs index 5f9f43a320b..b2cbbc21430 100644 --- a/compiler/rustc_const_eval/src/interpret/memory.rs +++ b/compiler/rustc_const_eval/src/interpret/memory.rs @@ -997,12 +997,12 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> { pub fn get_ptr_type_id( &self, ptr: Pointer<Option<M::Provenance>>, - ) -> InterpResult<'tcx, (Ty<'tcx>, Size)> { + ) -> InterpResult<'tcx, (Ty<'tcx>, u64)> { let (alloc_id, offset, _meta) = self.ptr_get_alloc_id(ptr, 0)?; let GlobalAlloc::TypeId { ty } = self.tcx.global_alloc(alloc_id) else { - throw_ub_format!("type_id_eq: `TypeId` provenance is not a type id") + throw_ub_format!("invalid `TypeId` value: not all bytes carry type id metadata") }; - interp_ok((ty, offset)) + interp_ok((ty, offset.bytes())) } pub fn get_ptr_fn( diff --git a/compiler/rustc_const_eval/src/interpret/stack.rs b/compiler/rustc_const_eval/src/interpret/stack.rs index b6ba069526c..2e99bb4209f 100644 --- a/compiler/rustc_const_eval/src/interpret/stack.rs +++ b/compiler/rustc_const_eval/src/interpret/stack.rs @@ -12,6 +12,7 @@ use rustc_middle::ty::{self, Ty, TyCtxt}; use rustc_middle::{bug, mir}; use rustc_mir_dataflow::impls::always_storage_live_locals; use rustc_span::Span; +use tracing::field::Empty; use tracing::{info_span, instrument, trace}; use super::{ @@ -396,7 +397,11 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> { // Finish things up. M::after_stack_push(self)?; self.frame_mut().loc = Left(mir::Location::START); - let span = info_span!("frame", "{}", instance); + // `tracing_separate_thread` is used to instruct the chrome_tracing [tracing::Layer] in Miri + // to put the "frame" span on a separate trace thread/line than other spans, to make the + // visualization in https://ui.perfetto.dev easier to interpret. It is set to a value of + // [tracing::field::Empty] so that other tracing layers (e.g. the logger) will ignore it. + let span = info_span!("frame", tracing_separate_thread = Empty, "{}", instance); self.frame_mut().tracing_span.enter(span); interp_ok(()) |