From 1157dc7167d13a9bdcafd30b8ad0ecf5ae5faa7f Mon Sep 17 00:00:00 2001 From: b-naber Date: Tue, 5 Apr 2022 16:33:42 +0200 Subject: [PATCH] implement valtree -> constvalue conversion --- .../src/const_eval/eval_queries.rs | 38 +- .../rustc_const_eval/src/const_eval/mod.rs | 136 +---- .../src/const_eval/valtrees.rs | 479 ++++++++++++++++++ .../rustc_const_eval/src/interpret/mod.rs | 2 +- .../rustc_const_eval/src/interpret/operand.rs | 5 +- .../rustc_const_eval/src/interpret/place.rs | 27 +- .../src/mir/interpret/allocation.rs | 5 + .../rustc_middle/src/mir/interpret/pointer.rs | 2 +- .../rustc_middle/src/ty/consts/valtree.rs | 3 + 9 files changed, 546 insertions(+), 151 deletions(-) create mode 100644 compiler/rustc_const_eval/src/const_eval/valtrees.rs diff --git a/compiler/rustc_const_eval/src/const_eval/eval_queries.rs b/compiler/rustc_const_eval/src/const_eval/eval_queries.rs index 7cca6178ab2..38fecf7232e 100644 --- a/compiler/rustc_const_eval/src/const_eval/eval_queries.rs +++ b/compiler/rustc_const_eval/src/const_eval/eval_queries.rs @@ -106,6 +106,7 @@ pub(super) fn mk_eval_cx<'mir, 'tcx>( /// This function converts an interpreter value into a constant that is meant for use in the /// type system. +#[instrument(skip(ecx), level = "debug")] pub(super) fn op_to_const<'tcx>( ecx: &CompileTimeEvalContext<'_, 'tcx>, op: &OpTy<'tcx>, @@ -140,21 +141,26 @@ pub(super) fn op_to_const<'tcx>( op.try_as_mplace() }; + debug!(?immediate); + // We know `offset` is relative to the allocation, so we can use `into_parts`. - let to_const_value = |mplace: &MPlaceTy<'_>| match mplace.ptr.into_parts() { - (Some(alloc_id), offset) => { - let alloc = ecx.tcx.global_alloc(alloc_id).unwrap_memory(); - ConstValue::ByRef { alloc, offset } - } - (None, offset) => { - assert!(mplace.layout.is_zst()); - assert_eq!( - offset.bytes() % mplace.layout.align.abi.bytes(), - 0, - "this MPlaceTy must come from a validated constant, thus we can assume the \ + let to_const_value = |mplace: &MPlaceTy<'_>| { + debug!("to_const_value(mplace: {:?})", mplace); + match mplace.ptr.into_parts() { + (Some(alloc_id), offset) => { + let alloc = ecx.tcx.global_alloc(alloc_id).unwrap_memory(); + ConstValue::ByRef { alloc, offset } + } + (None, offset) => { + assert!(mplace.layout.is_zst()); + assert_eq!( + offset.bytes() % mplace.layout.align.abi.bytes(), + 0, + "this MPlaceTy must come from a validated constant, thus we can assume the \ alignment is correct", - ); - ConstValue::Scalar(Scalar::ZST) + ); + ConstValue::Scalar(Scalar::ZST) + } } }; match immediate { @@ -166,6 +172,7 @@ pub(super) fn op_to_const<'tcx>( ScalarMaybeUninit::Uninit => to_const_value(&op.assert_mem_place()), }, Immediate::ScalarPair(a, b) => { + debug!("ScalarPair(a: {:?}, b: {:?})", a, b); // We know `offset` is relative to the allocation, so we can use `into_parts`. let (data, start) = match ecx.scalar_to_ptr(a.check_init().unwrap()).unwrap().into_parts() { @@ -209,7 +216,10 @@ fn turn_into_const_value<'tcx>( ); // Turn this into a proper constant. - op_to_const(&ecx, &mplace.into()) + let const_val = op_to_const(&ecx, &mplace.into()); + debug!(?const_val); + + const_val } pub fn eval_to_const_value_raw_provider<'tcx>( diff --git a/compiler/rustc_const_eval/src/const_eval/mod.rs b/compiler/rustc_const_eval/src/const_eval/mod.rs index 68f9bee593f..96c18d488ee 100644 --- a/compiler/rustc_const_eval/src/const_eval/mod.rs +++ b/compiler/rustc_const_eval/src/const_eval/mod.rs @@ -3,29 +3,26 @@ use std::convert::TryFrom; use rustc_hir::Mutability; -use rustc_middle::ty::layout::HasTyCtxt; +use rustc_middle::mir; use rustc_middle::ty::{self, TyCtxt}; -use rustc_middle::{ - mir::{self, interpret::ConstAlloc}, - ty::ScalarInt, -}; use rustc_span::{source_map::DUMMY_SP, symbol::Symbol}; -use rustc_target::abi::VariantIdx; use crate::interpret::{ - intern_const_alloc_recursive, ConstValue, InternKind, InterpCx, InterpResult, MPlaceTy, - MemPlaceMeta, Scalar, + intern_const_alloc_recursive, ConstValue, InternKind, InterpCx, InterpResult, MemPlaceMeta, + Scalar, }; mod error; mod eval_queries; mod fn_queries; mod machine; +mod valtrees; pub use error::*; pub use eval_queries::*; pub use fn_queries::*; pub use machine::*; +pub(crate) use valtrees::{const_to_valtree, valtree_to_const_value}; pub(crate) fn const_caller_location( tcx: TyCtxt<'_>, @@ -41,128 +38,6 @@ pub(crate) fn const_caller_location( ConstValue::Scalar(Scalar::from_maybe_pointer(loc_place.ptr, &tcx)) } -/// Convert an evaluated constant to a type level constant -pub(crate) fn const_to_valtree<'tcx>( - tcx: TyCtxt<'tcx>, - param_env: ty::ParamEnv<'tcx>, - raw: ConstAlloc<'tcx>, -) -> Option> { - let ecx = mk_eval_cx( - tcx, DUMMY_SP, param_env, - // It is absolutely crucial for soundness that - // we do not read from static items or other mutable memory. - false, - ); - let place = ecx.raw_const_to_mplace(raw).unwrap(); - const_to_valtree_inner(&ecx, &place) -} - -#[instrument(skip(ecx), level = "debug")] -fn branches<'tcx>( - ecx: &CompileTimeEvalContext<'tcx, 'tcx>, - place: &MPlaceTy<'tcx>, - n: usize, - variant: Option, -) -> Option> { - let place = match variant { - Some(variant) => ecx.mplace_downcast(&place, variant).unwrap(), - None => *place, - }; - let variant = variant.map(|variant| Some(ty::ValTree::Leaf(ScalarInt::from(variant.as_u32())))); - debug!(?place, ?variant); - - let fields = (0..n).map(|i| { - let field = ecx.mplace_field(&place, i).unwrap(); - const_to_valtree_inner(ecx, &field) - }); - // For enums, we prepend their variant index before the variant's fields so we can figure out - // the variant again when just seeing a valtree. - let branches = variant.into_iter().chain(fields); - Some(ty::ValTree::Branch(ecx.tcx.arena.alloc_from_iter(branches.collect::>>()?))) -} - -fn slice_branches<'tcx>( - ecx: &CompileTimeEvalContext<'tcx, 'tcx>, - place: &MPlaceTy<'tcx>, -) -> Option> { - let n = place.len(&ecx.tcx()).expect(&format!("expected to use len of place {:?}", place)); - let branches = (0..n).map(|i| { - let place_elem = ecx.mplace_index(place, i).unwrap(); - const_to_valtree_inner(ecx, &place_elem) - }); - - Some(ty::ValTree::Branch(ecx.tcx.arena.alloc_from_iter(branches.collect::>>()?))) -} - -#[instrument(skip(ecx), level = "debug")] -fn const_to_valtree_inner<'tcx>( - ecx: &CompileTimeEvalContext<'tcx, 'tcx>, - place: &MPlaceTy<'tcx>, -) -> Option> { - match place.layout.ty.kind() { - ty::FnDef(..) => Some(ty::ValTree::zst()), - ty::Bool | ty::Int(_) | ty::Uint(_) | ty::Float(_) | ty::Char => { - let val = ecx.read_immediate(&place.into()).unwrap(); - let val = val.to_scalar().unwrap(); - Some(ty::ValTree::Leaf(val.assert_int())) - } - - // Raw pointers are not allowed in type level constants, as we cannot properly test them for - // equality at compile-time (see `ptr_guaranteed_eq`/`_ne`). - // Technically we could allow function pointers (represented as `ty::Instance`), but this is not guaranteed to - // agree with runtime equality tests. - ty::FnPtr(_) | ty::RawPtr(_) => None, - - ty::Ref(_, _, _) => { - let derefd_place = ecx.deref_operand(&place.into()).unwrap_or_else(|e| bug!("couldn't deref {:?}, error: {:?}", place, e)); - debug!(?derefd_place); - - const_to_valtree_inner(ecx, &derefd_place) - } - - ty::Str | ty::Slice(_) | ty::Array(_, _) => { - let valtree = slice_branches(ecx, place); - debug!(?valtree); - - valtree - } - // Trait objects are not allowed in type level constants, as we have no concept for - // resolving their backing type, even if we can do that at const eval time. We may - // hypothetically be able to allow `dyn StructuralEq` trait objects in the future, - // but it is unclear if this is useful. - ty::Dynamic(..) => None, - - ty::Tuple(substs) => branches(ecx, place, substs.len(), None), - - ty::Adt(def, _) => { - if def.variants().is_empty() { - bug!("uninhabited types should have errored and never gotten converted to valtree") - } - - let variant = ecx.read_discriminant(&place.into()).unwrap().1; - - branches(ecx, place, def.variant(variant).fields.len(), def.is_enum().then_some(variant)) - } - - ty::Never - | ty::Error(_) - | ty::Foreign(..) - | ty::Infer(ty::FreshIntTy(_)) - | ty::Infer(ty::FreshFloatTy(_)) - | ty::Projection(..) - | ty::Param(_) - | ty::Bound(..) - | ty::Placeholder(..) - // FIXME(oli-obk): we could look behind opaque types - | ty::Opaque(..) - | ty::Infer(_) - // FIXME(oli-obk): we can probably encode closures just like structs - | ty::Closure(..) - | ty::Generator(..) - | ty::GeneratorWitness(..) => None, - } -} - /// This function should never fail for validated constants. However, it is also invoked from the /// pretty printer which might attempt to format invalid constants and in that case it might fail. pub(crate) fn try_destructure_const<'tcx>( @@ -202,6 +77,7 @@ pub(crate) fn try_destructure_const<'tcx>( Ok(mir::DestructuredConst { variant, fields }) } +#[instrument(skip(tcx), level = "debug")] pub(crate) fn deref_const<'tcx>( tcx: TyCtxt<'tcx>, param_env: ty::ParamEnv<'tcx>, diff --git a/compiler/rustc_const_eval/src/const_eval/valtrees.rs b/compiler/rustc_const_eval/src/const_eval/valtrees.rs new file mode 100644 index 00000000000..ded539fd340 --- /dev/null +++ b/compiler/rustc_const_eval/src/const_eval/valtrees.rs @@ -0,0 +1,479 @@ +use super::eval_queries::{mk_eval_cx, op_to_const}; +use super::machine::CompileTimeEvalContext; +use crate::interpret::{ + intern_const_alloc_recursive, ConstValue, ImmTy, Immediate, InternKind, MemoryKind, PlaceTy, + Pointer, Scalar, ScalarMaybeUninit, +}; +use rustc_middle::mir::interpret::{ConstAlloc, GlobalAlloc}; +use rustc_middle::mir::{Field, ProjectionElem}; +use rustc_middle::ty::{self, ScalarInt, Ty, TyCtxt}; +use rustc_span::source_map::DUMMY_SP; +use rustc_target::abi::VariantIdx; + +use crate::interpret::visitor::Value; +use crate::interpret::MPlaceTy; + +/// Convert an evaluated constant to a type level constant +#[instrument(skip(tcx), level = "debug")] +pub(crate) fn const_to_valtree<'tcx>( + tcx: TyCtxt<'tcx>, + param_env: ty::ParamEnv<'tcx>, + raw: ConstAlloc<'tcx>, +) -> Option> { + let ecx = mk_eval_cx( + tcx, DUMMY_SP, param_env, + // It is absolutely crucial for soundness that + // we do not read from static items or other mutable memory. + false, + ); + let place = ecx.raw_const_to_mplace(raw).unwrap(); + const_to_valtree_inner(&ecx, &place) +} + +#[instrument(skip(ecx), level = "debug")] +fn branches<'tcx>( + ecx: &CompileTimeEvalContext<'tcx, 'tcx>, + place: &MPlaceTy<'tcx>, + n: usize, + variant: Option, +) -> Option> { + let place = match variant { + Some(variant) => ecx.mplace_downcast(&place, variant).unwrap(), + None => *place, + }; + let variant = variant.map(|variant| Some(ty::ValTree::Leaf(ScalarInt::from(variant.as_u32())))); + debug!(?place, ?variant); + + let fields = (0..n).map(|i| { + let field = ecx.mplace_field(&place, i).unwrap(); + const_to_valtree_inner(ecx, &field) + }); + // For enums, we preped their variant index before the variant's fields so we can figure out + // the variant again when just seeing a valtree. + let branches = variant.into_iter().chain(fields); + Some(ty::ValTree::Branch(ecx.tcx.arena.alloc_from_iter(branches.collect::>>()?))) +} + +fn slice_branches<'tcx>( + ecx: &CompileTimeEvalContext<'tcx, 'tcx>, + place: &MPlaceTy<'tcx>, +) -> Option> { + let n = place.len(&ecx.tcx.tcx).expect(&format!("expected to use len of place {:?}", place)); + let branches = (0..n).map(|i| { + let place_elem = ecx.mplace_index(place, i).unwrap(); + const_to_valtree_inner(ecx, &place_elem) + }); + + Some(ty::ValTree::Branch(ecx.tcx.arena.alloc_from_iter(branches.collect::>>()?))) +} + +#[instrument(skip(ecx), level = "debug")] +fn const_to_valtree_inner<'tcx>( + ecx: &CompileTimeEvalContext<'tcx, 'tcx>, + place: &MPlaceTy<'tcx>, +) -> Option> { + match place.layout.ty.kind() { + ty::FnDef(..) => Some(ty::ValTree::zst()), + ty::Bool | ty::Int(_) | ty::Uint(_) | ty::Float(_) | ty::Char => { + let val = ecx.read_immediate(&place.into()).unwrap(); + let val = val.to_scalar().unwrap(); + Some(ty::ValTree::Leaf(val.assert_int())) + } + + // Raw pointers are not allowed in type level constants, as we cannot properly test them for + // equality at compile-time (see `ptr_guaranteed_eq`/`_ne`). + // Technically we could allow function pointers (represented as `ty::Instance`), but this is not guaranteed to + // agree with runtime equality tests. + ty::FnPtr(_) | ty::RawPtr(_) => None, + + ty::Ref(_, _, _) => { + let derefd_place = ecx.deref_operand(&place.into()).unwrap_or_else(|e| bug!("couldn't deref {:?}, error: {:?}", place, e)); + debug!(?derefd_place); + + const_to_valtree_inner(ecx, &derefd_place) + } + + ty::Str | ty::Slice(_) | ty::Array(_, _) => { + let valtree = slice_branches(ecx, place); + debug!(?valtree); + + valtree + } + // Trait objects are not allowed in type level constants, as we have no concept for + // resolving their backing type, even if we can do that at const eval time. We may + // hypothetically be able to allow `dyn StructuralEq` trait objects in the future, + // but it is unclear if this is useful. + ty::Dynamic(..) => None, + + ty::Tuple(substs) => branches(ecx, place, substs.len(), None), + + ty::Adt(def, _) => { + if def.variants().is_empty() { + bug!("uninhabited types should have errored and never gotten converted to valtree") + } + + let variant = ecx.read_discriminant(&place.into()).unwrap().1; + + branches(ecx, place, def.variant(variant).fields.len(), def.is_enum().then_some(variant)) + } + + ty::Never + | ty::Error(_) + | ty::Foreign(..) + | ty::Infer(ty::FreshIntTy(_)) + | ty::Infer(ty::FreshFloatTy(_)) + | ty::Projection(..) + | ty::Param(_) + | ty::Bound(..) + | ty::Placeholder(..) + // FIXME(oli-obk): we could look behind opaque types + | ty::Opaque(..) + | ty::Infer(_) + // FIXME(oli-obk): we can probably encode closures just like structs + | ty::Closure(..) + | ty::Generator(..) + | ty::GeneratorWitness(..) => None, + } +} + +#[instrument(skip(ecx), level = "debug")] +fn create_mplace_from_layout<'tcx>( + ecx: &mut CompileTimeEvalContext<'tcx, 'tcx>, + param_env_ty: ty::ParamEnvAnd<'tcx, Ty<'tcx>>, +) -> MPlaceTy<'tcx> { + let tcx = ecx.tcx; + let layout = tcx.layout_of(param_env_ty).unwrap(); + debug!(?layout); + + ecx.allocate(layout, MemoryKind::Stack).unwrap() +} + +/// Converts a `ValTree` to a `ConstValue`, which is needed after mir +/// construction has finished. +#[instrument(skip(tcx), level = "debug")] +pub fn valtree_to_const_value<'tcx>( + tcx: TyCtxt<'tcx>, + param_env_ty: ty::ParamEnvAnd<'tcx, Ty<'tcx>>, + valtree: ty::ValTree<'tcx>, +) -> ConstValue<'tcx> { + // Basic idea: We directly construct `Scalar` values from trivial `ValTree`s + // (those for constants with type bool, int, uint, float or char). + // For all other types we create an `MPlace` and fill that by walking + // the `ValTree` and using `place_projection` and `place_field` to + // create inner `MPlace`s which are filled recursively. + // FIXME Does this need an example? + + let (param_env, ty) = param_env_ty.into_parts(); + let mut ecx = mk_eval_cx(tcx, DUMMY_SP, param_env, false); + + match ty.kind() { + ty::Bool | ty::Int(_) | ty::Uint(_) | ty::Float(_) | ty::Char => match valtree { + ty::ValTree::Leaf(scalar_int) => ConstValue::Scalar(Scalar::Int(scalar_int)), + ty::ValTree::Branch(_) => bug!( + "ValTrees for Bool, Int, Uint, Float or Char should have the form ValTree::Leaf" + ), + }, + ty::Ref(_, inner_ty, _) => { + match inner_ty.kind() { + ty::Slice(_) | ty::Str => { + let slice_ty = match inner_ty.kind() { + ty::Slice(slice_ty) => *slice_ty, + ty::Str => tcx.mk_ty(ty::Uint(ty::UintTy::U8)), + _ => bug!("expected ty::Slice | ty::Str"), + }; + debug!(?slice_ty); + + let valtrees = valtree.unwrap_branch(); + + // Create a place for the underlying array + let len = valtrees.len(); + let arr_ty = tcx.mk_array(slice_ty, len as u64); + let mut place = + create_mplace_from_layout(&mut ecx, ty::ParamEnv::empty().and(arr_ty)); + debug!(?place); + + // Insert elements of `arr_valtree` into `place` + fill_place_recursively(&mut ecx, &mut place, valtree, arr_ty); + dump_place(&ecx, place.into()); + + // The allocation behind `place` is local, we need to intern it + intern_const_alloc_recursive(&mut ecx, InternKind::Constant, &place).unwrap(); + + // Now we need to get the Allocation + let alloc_id = place.mplace.ptr.provenance.unwrap(); + debug!(?alloc_id); + + let data = match tcx.get_global_alloc(alloc_id) { + Some(GlobalAlloc::Memory(const_alloc)) => const_alloc, + _ => bug!("expected memory allocation"), + }; + debug!(?data); + + return ConstValue::Slice { data, start: 0, end: len as usize }; + } + _ => { + match valtree { + ty::ValTree::Branch(_) => { + // create a place for the pointee + let mut place = create_mplace_from_layout( + &mut ecx, + ty::ParamEnv::empty().and(*inner_ty), + ); + debug!(?place); + + // insert elements of valtree into `place` + fill_place_recursively(&mut ecx, &mut place, valtree, *inner_ty); + dump_place(&ecx, place.into()); + intern_const_alloc_recursive(&mut ecx, InternKind::Constant, &place) + .unwrap(); + + let ref_place = place.mplace.to_ref(&tcx); + let imm = ImmTy::from_immediate( + ref_place, + tcx.layout_of(param_env_ty).unwrap(), + ); + + let const_val = op_to_const(&ecx, &imm.into()); + debug!(?const_val); + + const_val + } + ty::ValTree::Leaf(_) => { + let mut place = create_mplace_from_layout( + &mut ecx, + ty::ParamEnv::empty().and(*inner_ty), + ); + + fill_place_recursively(&mut ecx, &mut place, valtree, *inner_ty); + dump_place(&ecx, place.into()); + + let ref_place = place.mplace.to_ref(&tcx); + let imm = ImmTy::from_immediate( + ref_place, + tcx.layout_of(param_env_ty).unwrap(), + ); + + op_to_const(&ecx, &imm.into()) + } + } + } + } + } + ty::Tuple(_) | ty::Array(_, _) | ty::Adt(..) => { + let mut place = create_mplace_from_layout(&mut ecx, param_env_ty); + debug!(?place); + + fill_place_recursively(&mut ecx, &mut place, valtree, ty); + dump_place(&ecx, place.into()); + intern_const_alloc_recursive(&mut ecx, InternKind::Constant, &place).unwrap(); + + let const_val = op_to_const(&ecx, &place.into()); + debug!(?const_val); + + const_val + } + ty::Never + | ty::FnDef(..) + | ty::Error(_) + | ty::Foreign(..) + | ty::Infer(ty::FreshIntTy(_)) + | ty::Infer(ty::FreshFloatTy(_)) + | ty::Projection(..) + | ty::Param(_) + | ty::Bound(..) + | ty::Placeholder(..) + | ty::Opaque(..) + | ty::Infer(_) + | ty::Closure(..) + | ty::Generator(..) + | ty::GeneratorWitness(..) + | ty::FnPtr(_) + | ty::RawPtr(_) + | ty::Str + | ty::Slice(_) + | ty::Dynamic(..) => bug!("no ValTree should have been created for type {:?}", ty.kind()), + } +} + +// FIXME Needs a better/correct name +#[instrument(skip(ecx), level = "debug")] +fn fill_place_recursively<'tcx>( + ecx: &mut CompileTimeEvalContext<'tcx, 'tcx>, + place: &mut MPlaceTy<'tcx>, + valtree: ty::ValTree<'tcx>, + ty: Ty<'tcx>, +) { + // This will match on valtree and write the value(s) corresponding to the ValTree + // inside the place recursively. + + let tcx = ecx.tcx.tcx; + + match ty.kind() { + ty::Bool | ty::Int(_) | ty::Uint(_) | ty::Float(_) | ty::Char => { + let scalar_int = valtree.unwrap_leaf(); + debug!("writing trivial valtree {:?} to place {:?}", scalar_int, place); + ecx.write_immediate( + Immediate::Scalar(ScalarMaybeUninit::Scalar(scalar_int.into())), + &(*place).into(), + ) + .unwrap(); + } + ty::Ref(_, inner_ty, _) => { + match inner_ty.kind() { + ty::Slice(_) | ty::Str => { + let slice_ty = match inner_ty.kind() { + ty::Slice(slice_ty) => *slice_ty, + ty::Str => tcx.mk_ty(ty::Uint(ty::UintTy::U8)), + _ => bug!("expected ty::Slice | ty::Str"), + }; + debug!(?slice_ty); + + let valtrees = valtree.unwrap_branch(); + debug!(?valtrees); + let len = valtrees.len(); + debug!(?len); + + // create a place for the underlying array + let arr_ty = tcx.mk_array(slice_ty, len as u64); + let mut arr_place = + create_mplace_from_layout(ecx, ty::ParamEnv::empty().and(arr_ty)); + debug!(?arr_place); + + // Insert elements of `arr_valtree` into `place` + fill_place_recursively(ecx, &mut arr_place, valtree, arr_ty); + dump_place(&ecx, arr_place.into()); + + // Now we need to create a `ScalarPair` from the filled `place` + // and write that into `place` + let (alloc_id, offset) = arr_place.mplace.ptr.into_parts(); + debug!(?alloc_id, ?offset); + let unwrapped_ptr = Pointer { offset, provenance: alloc_id.unwrap() }; + let len_scalar = ScalarMaybeUninit::Scalar(Scalar::from_u64(len as u64)); + + let imm = Immediate::ScalarPair( + ScalarMaybeUninit::from_pointer(unwrapped_ptr, &tcx), + len_scalar, + ); + debug!(?imm); + + // Now write the ScalarPair into the original place we wanted to fill + // in this call + let _ = ecx.write_immediate(imm, &(*place).into()).unwrap(); + + dump_place(&ecx, (*place).into()); + } + _ => { + let mut pointee_place = + create_mplace_from_layout(ecx, ty::ParamEnv::empty().and(*inner_ty)); + debug!(?pointee_place); + fill_place_recursively(ecx, &mut pointee_place, valtree, *inner_ty); + + dump_place(ecx, pointee_place.into()); + intern_const_alloc_recursive(ecx, InternKind::Constant, &pointee_place) + .unwrap(); + + let imm = pointee_place.mplace.to_ref(&tcx); + debug!(?imm); + + ecx.write_immediate(imm, &(*place).into()).unwrap(); + } + } + } + ty::Tuple(tuple_types) => { + let branches = valtree.unwrap_branch(); + assert_eq!(tuple_types.len(), branches.len()); + + for (i, inner_valtree) in branches.iter().enumerate() { + debug!(?i, ?inner_valtree); + let inner_ty = tuple_types.get(i).expect(&format!( + "expected to be able to index at position {} into {:?}", + i, tuple_types + )); + debug!(?inner_ty); + + // Create the mplace for the tuple element + let mut place_inner = ecx.mplace_field(place, i).unwrap(); + debug!(?place_inner); + + // insert valtree corresponding to tuple element into place + fill_place_recursively(ecx, &mut place_inner, *inner_valtree, *inner_ty); + } + } + ty::Array(inner_ty, _) => { + let inner_valtrees = valtree.unwrap_branch(); + for (i, inner_valtree) in inner_valtrees.iter().enumerate() { + debug!(?i, ?inner_valtree); + + let mut place_inner = ecx.mplace_field(place, i).unwrap(); + debug!(?place_inner); + + fill_place_recursively(ecx, &mut place_inner, *inner_valtree, *inner_ty) + } + } + ty::Adt(def, substs) if def.is_enum() => { + debug!("enum, substs: {:?}", substs); + let inner_valtrees = valtree.unwrap_branch(); + + // First element of valtree corresponds to variant + let scalar_int = inner_valtrees[0].unwrap_leaf(); + let variant_idx = VariantIdx::from_u32(scalar_int.try_to_u32().unwrap()); + let variant = def.variant(variant_idx); + debug!(?variant); + + // Need to downcast place + let place_downcast = place.project_downcast(ecx, variant_idx).unwrap(); + debug!(?place_downcast); + + // fill `place_downcast` with the valtree elements corresponding to + // the fields of the enum + let fields = &variant.fields; + let inner_valtrees = &inner_valtrees[1..]; + for (i, field) in fields.iter().enumerate() { + debug!(?i, ?field); + + let field_ty = field.ty(tcx, substs); + debug!(?field_ty); + + let mut field_mplace = ecx.mplace_field(&place_downcast, i).unwrap(); + debug!(?field_mplace); + let inner_valtree = inner_valtrees[i]; + + fill_place_recursively(ecx, &mut field_mplace, inner_valtree, field_ty); + dump_place(&ecx, field_mplace.into()); + } + + debug!("dump of place_downcast"); + dump_place(ecx, place_downcast.into()); + + // don't forget filling the place with the discriminant of the enum + ecx.write_discriminant(variant_idx, &(*place).into()).unwrap(); + dump_place(ecx, (*place).into()); + } + ty::Adt(def, substs) => { + debug!("Adt def: {:?} with substs: {:?}", def, substs); + let inner_valtrees = valtree.unwrap_branch(); + debug!(?inner_valtrees); + let (fields, inner_valtrees) = + (&def.variant(VariantIdx::from_usize(0)).fields[..], inner_valtrees); + + debug!("fields: {:?}", fields); + + for (i, field) in fields.iter().enumerate() { + let field_ty = field.ty(tcx, substs); + debug!(?field_ty); + let old_field_ty = tcx.type_of(field.did); + debug!(?old_field_ty); + let projection_elem = ProjectionElem::Field(Field::from_usize(i), field_ty); + let mut field_place = ecx.mplace_projection(place, projection_elem).unwrap(); + let inner_valtree = inner_valtrees[i]; + + fill_place_recursively(ecx, &mut field_place, inner_valtree, field_ty); + } + } + _ => {} + } +} + +fn dump_place<'tcx>(ecx: &CompileTimeEvalContext<'tcx, 'tcx>, place: PlaceTy<'tcx>) { + trace!("{:?}", ecx.dump_place(place.place)); +} diff --git a/compiler/rustc_const_eval/src/interpret/mod.rs b/compiler/rustc_const_eval/src/interpret/mod.rs index 2b9fe565997..dba746e72e2 100644 --- a/compiler/rustc_const_eval/src/interpret/mod.rs +++ b/compiler/rustc_const_eval/src/interpret/mod.rs @@ -14,7 +14,7 @@ mod terminator; mod traits; mod util; mod validity; -mod visitor; +pub(crate) mod visitor; pub use rustc_middle::mir::interpret::*; // have all the `interpret` symbols in one place: here diff --git a/compiler/rustc_const_eval/src/interpret/operand.rs b/compiler/rustc_const_eval/src/interpret/operand.rs index dfc0028e87f..170fbab2cce 100644 --- a/compiler/rustc_const_eval/src/interpret/operand.rs +++ b/compiler/rustc_const_eval/src/interpret/operand.rs @@ -98,7 +98,7 @@ impl<'tcx, Tag: Provenance> Immediate { // as input for binary and cast operations. #[derive(Copy, Clone, Debug)] pub struct ImmTy<'tcx, Tag: Provenance = AllocId> { - imm: Immediate, + pub imm: Immediate, pub layout: TyAndLayout<'tcx>, } @@ -248,7 +248,7 @@ impl<'tcx, Tag: Provenance> ImmTy<'tcx, Tag> { impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> { /// Try reading an immediate in memory; this is interesting particularly for `ScalarPair`. /// Returns `None` if the layout does not permit loading this as a value. - fn try_read_immediate_from_mplace( + pub(crate) fn try_read_immediate_from_mplace( &self, mplace: &MPlaceTy<'tcx, M::PointerTag>, ) -> InterpResult<'tcx, Option>> { @@ -424,6 +424,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> { }) } + #[instrument(skip(self), level = "debug")] pub fn operand_projection( &self, base: &OpTy<'tcx, M::PointerTag>, diff --git a/compiler/rustc_const_eval/src/interpret/place.rs b/compiler/rustc_const_eval/src/interpret/place.rs index e4660fe090c..8caf9eee2d9 100644 --- a/compiler/rustc_const_eval/src/interpret/place.rs +++ b/compiler/rustc_const_eval/src/interpret/place.rs @@ -82,7 +82,7 @@ rustc_data_structures::static_assert_size!(Place, 56); #[derive(Copy, Clone, Debug)] pub struct PlaceTy<'tcx, Tag: Provenance = AllocId> { - place: Place, // Keep this private; it helps enforce invariants. + pub(crate) place: Place, // Keep this private; it helps enforce invariants. pub layout: TyAndLayout<'tcx>, } @@ -100,7 +100,7 @@ impl<'tcx, Tag: Provenance> std::ops::Deref for PlaceTy<'tcx, Tag> { /// A MemPlace with its layout. Constructing it is only possible in this module. #[derive(Copy, Clone, Hash, Eq, PartialEq, Debug)] pub struct MPlaceTy<'tcx, Tag: Provenance = AllocId> { - mplace: MemPlace, + pub(crate) mplace: MemPlace, pub layout: TyAndLayout<'tcx>, } @@ -294,6 +294,7 @@ where /// Take an operand, representing a pointer, and dereference it to a place -- that /// will always be a MemPlace. Lives in `place.rs` because it creates a place. + #[instrument(skip(self), level = "debug")] pub fn deref_operand( &self, src: &OpTy<'tcx, M::PointerTag>, @@ -487,7 +488,8 @@ where } /// Project into an mplace - pub(super) fn mplace_projection( + #[instrument(skip(self), level = "debug")] + pub(crate) fn mplace_projection( &self, base: &MPlaceTy<'tcx, M::PointerTag>, proj_elem: mir::PlaceElem<'tcx>, @@ -548,6 +550,7 @@ where /// Just a convenience function, but used quite a bit. /// This is the only projection that might have a side-effect: We cannot project /// into the field of a local `ScalarPair`, we have to first allocate it. + #[instrument(skip(self), level = "debug")] pub fn place_field( &mut self, base: &PlaceTy<'tcx, M::PointerTag>, @@ -586,6 +589,7 @@ where } /// Projects into a place. + #[instrument(skip(self), level = "debug")] pub fn place_projection( &mut self, base: &PlaceTy<'tcx, M::PointerTag>, @@ -617,19 +621,23 @@ where /// Computes a place. You should only use this if you intend to write into this /// place; for reading, a more efficient alternative is `eval_place_for_read`. + #[instrument(skip(self), level = "debug")] pub fn eval_place( &mut self, place: mir::Place<'tcx>, ) -> InterpResult<'tcx, PlaceTy<'tcx, M::PointerTag>> { + debug!("projection: {:?}", place.projection); let mut place_ty = PlaceTy { // This works even for dead/uninitialized locals; we check further when writing place: Place::Local { frame: self.frame_idx(), local: place.local }, layout: self.layout_of_local(self.frame(), place.local, None)?, }; + debug!(?place_ty); for elem in place.projection.iter() { place_ty = self.place_projection(&place_ty, &elem)? } + debug!("place after projections: {:?}", place_ty); trace!("{:?}", self.dump_place(place_ty.place)); // Sanity-check the type we ended up with. @@ -646,6 +654,7 @@ where /// Write an immediate to a place #[inline(always)] + #[instrument(skip(self), level = "debug")] pub fn write_immediate( &mut self, src: Immediate, @@ -684,6 +693,7 @@ where /// Write an immediate to a place. /// If you use this you are responsible for validating that things got copied at the /// right type. + #[instrument(skip(self), level = "debug")] fn write_immediate_no_validate( &mut self, src: Immediate, @@ -736,6 +746,7 @@ where /// Write an immediate to memory. /// If you use this you are responsible for validating that things got copied at the /// right type. + #[instrument(skip(self), level = "debug")] fn write_immediate_to_mplace_no_validate( &mut self, value: Immediate, @@ -758,6 +769,7 @@ where // cover all the bytes! match value { Immediate::Scalar(scalar) => { + debug!(?scalar); match dest.layout.abi { Abi::Scalar(_) => {} // fine _ => span_bug!( @@ -830,6 +842,7 @@ where /// Copies the data from an operand to a place. This does not support transmuting! /// Use `copy_op_transmute` if the layouts could disagree. #[inline(always)] + #[instrument(skip(self), level = "debug")] pub fn copy_op( &mut self, src: &OpTy<'tcx, M::PointerTag>, @@ -849,6 +862,7 @@ where /// Use `copy_op_transmute` if the layouts could disagree. /// Also, if you use this you are responsible for validating that things get copied at the /// right type. + #[instrument(skip(self), level = "debug")] fn copy_op_no_validate( &mut self, src: &OpTy<'tcx, M::PointerTag>, @@ -868,6 +882,7 @@ where // Let us see if the layout is simple so we take a shortcut, avoid force_allocation. let src = match self.try_read_immediate(src)? { Ok(src_val) => { + debug!("immediate from src is {:?}", src_val); assert!(!src.layout.is_unsized(), "cannot have unsized immediates"); // Yay, we got a value that we can write directly. // FIXME: Add a check to make sure that if `src` is indirect, @@ -955,6 +970,7 @@ where /// This supports unsized types and returns the computed size to avoid some /// redundant computation when copying; use `force_allocation` for a simpler, sized-only /// version. + #[instrument(skip(self), level = "debug")] pub fn force_allocation_maybe_sized( &mut self, place: &PlaceTy<'tcx, M::PointerTag>, @@ -962,6 +978,7 @@ where ) -> InterpResult<'tcx, (MPlaceTy<'tcx, M::PointerTag>, Option)> { let (mplace, size) = match place.place { Place::Local { frame, local } => { + debug!("LocalPlace"); match M::access_local_mut(self, frame, local)? { Ok(&mut local_val) => { // We need to make an allocation. @@ -975,9 +992,12 @@ where let (size, align) = self .size_and_align_of(&meta, &local_layout)? .expect("Cannot allocate for non-dyn-sized type"); + debug!(?size, ?align); let ptr = self.allocate_ptr(size, align, MemoryKind::Stack)?; + debug!("allocated ptr: {:?}", ptr); let mplace = MemPlace { ptr: ptr.into(), align, meta }; if let LocalValue::Live(Operand::Immediate(value)) = local_val { + debug!("LocalValue::Live: immediate value {:?}", value); // Preserve old value. // We don't have to validate as we can assume the local // was already valid for its type. @@ -1037,6 +1057,7 @@ where } /// Writes the discriminant of the given variant. + #[instrument(skip(self), level = "debug")] pub fn write_discriminant( &mut self, variant_index: VariantIdx, diff --git a/compiler/rustc_middle/src/mir/interpret/allocation.rs b/compiler/rustc_middle/src/mir/interpret/allocation.rs index c628406064f..5e7e362eeef 100644 --- a/compiler/rustc_middle/src/mir/interpret/allocation.rs +++ b/compiler/rustc_middle/src/mir/interpret/allocation.rs @@ -418,6 +418,7 @@ impl Allocation { /// /// It is the caller's responsibility to check bounds and alignment beforehand. /// Most likely, you want to call `InterpCx::write_scalar` instead of this method. + #[instrument(skip(self, cx), level = "debug")] pub fn write_scalar( &mut self, cx: &impl HasDataLayout, @@ -432,6 +433,7 @@ impl Allocation { return self.write_uninit(cx, range); } }; + debug!(?val); // `to_bits_or_ptr_internal` is the right method because we just want to store this data // as-is into memory. @@ -442,13 +444,16 @@ impl Allocation { } Ok(data) => (data, None), }; + debug!(?bytes, ?provenance); let endian = cx.data_layout().endian; let dst = self.get_bytes_mut(cx, range)?; + debug!(?dst); write_target_uint(endian, dst, bytes).unwrap(); // See if we have to also write a relocation. if let Some(provenance) = provenance { + debug!("insert relocation for {:?}", provenance); self.relocations.0.insert(range.start, provenance); } diff --git a/compiler/rustc_middle/src/mir/interpret/pointer.rs b/compiler/rustc_middle/src/mir/interpret/pointer.rs index c71aea417ec..cb36e540954 100644 --- a/compiler/rustc_middle/src/mir/interpret/pointer.rs +++ b/compiler/rustc_middle/src/mir/interpret/pointer.rs @@ -158,7 +158,7 @@ impl Provenance for AllocId { #[derive(Copy, Clone, Eq, PartialEq, Ord, PartialOrd, TyEncodable, TyDecodable, Hash)] #[derive(HashStable)] pub struct Pointer { - pub(super) offset: Size, // kept private to avoid accidental misinterpretation (meaning depends on `Tag` type) + pub offset: Size, // FIXME This should probably be private pub provenance: Tag, } diff --git a/compiler/rustc_middle/src/ty/consts/valtree.rs b/compiler/rustc_middle/src/ty/consts/valtree.rs index e17c69cb353..418848f69d7 100644 --- a/compiler/rustc_middle/src/ty/consts/valtree.rs +++ b/compiler/rustc_middle/src/ty/consts/valtree.rs @@ -20,6 +20,9 @@ pub enum ValTree<'tcx> { /// See the `ScalarInt` documentation for how `ScalarInt` guarantees that equal values /// of these types have the same representation. Leaf(ScalarInt), + + //SliceOrStr(ValSlice<'tcx>), + // dont use SliceOrStr for now /// The fields of any kind of aggregate. Structs, tuples and arrays are represented by /// listing their fields' values in order. /// Enums are represented by storing their discriminant as a field, followed by all