diff options
4 files changed, 59 insertions, 27 deletions
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 498b2f1b081..7cca6178ab2 100644 --- a/compiler/rustc_const_eval/src/const_eval/eval_queries.rs +++ b/compiler/rustc_const_eval/src/const_eval/eval_queries.rs @@ -188,6 +188,7 @@ pub(super) fn op_to_const<'tcx>( } } +#[instrument(skip(tcx), level = "debug")] fn turn_into_const_value<'tcx>( tcx: TyCtxt<'tcx>, constant: ConstAlloc<'tcx>, @@ -206,6 +207,7 @@ fn turn_into_const_value<'tcx>( !is_static || cid.promoted.is_some(), "the `eval_to_const_value_raw` query should not be used for statics, use `eval_to_allocation` instead" ); + // Turn this into a proper constant. op_to_const(&ecx, &mplace.into()) } diff --git a/compiler/rustc_const_eval/src/const_eval/mod.rs b/compiler/rustc_const_eval/src/const_eval/mod.rs index 6fd7f707e7e..80270f82563 100644 --- a/compiler/rustc_const_eval/src/const_eval/mod.rs +++ b/compiler/rustc_const_eval/src/const_eval/mod.rs @@ -3,12 +3,14 @@ use std::convert::TryFrom; use rustc_hir::Mutability; +use rustc_middle::ty::layout::HasTyCtxt; 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, @@ -55,28 +57,48 @@ pub(crate) fn const_to_valtree<'tcx>( const_to_valtree_inner(&ecx, &place) } -fn const_to_valtree_inner<'tcx>( +#[instrument(skip(ecx), level = "debug")] +fn branches<'tcx>( ecx: &CompileTimeEvalContext<'tcx, 'tcx>, place: &MPlaceTy<'tcx>, + n: usize, + variant: Option<VariantIdx>, ) -> Option<ty::ValTree<'tcx>> { - let branches = |n, variant| { - 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())))); - 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::<Option<Vec<_>>>()?), - )) + 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::<Option<Vec<_>>>()?))) +} + +fn slice_branches<'tcx>( + ecx: &CompileTimeEvalContext<'tcx, 'tcx>, + place: &MPlaceTy<'tcx>, +) -> Option<ty::ValTree<'tcx>> { + 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::<Option<Vec<_>>>()?))) +} + +#[instrument(skip(ecx), level = "debug")] +fn const_to_valtree_inner<'tcx>( + ecx: &CompileTimeEvalContext<'tcx, 'tcx>, + place: &MPlaceTy<'tcx>, +) -> Option<ty::ValTree<'tcx>> { match place.layout.ty.kind() { ty::FnDef(..) => Some(ty::ValTree::zst()), ty::Bool | ty::Int(_) | ty::Uint(_) | ty::Float(_) | ty::Char => { @@ -90,19 +112,27 @@ fn const_to_valtree_inner<'tcx>( // 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(..) => unimplemented!("need to use deref_const"), + 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::Slice(_) | ty::Str => { - unimplemented!("need to find the backing data of the slice/str and recurse on that") - } - ty::Tuple(substs) => branches(substs.len(), None), - ty::Array(_, len) => branches(usize::try_from(len.eval_usize(ecx.tcx.tcx, ecx.param_env)).unwrap(), None), + ty::Tuple(substs) => branches(ecx, place, substs.len(), None), ty::Adt(def, _) => { if def.variants().is_empty() { @@ -111,7 +141,7 @@ fn const_to_valtree_inner<'tcx>( let variant = ecx.read_discriminant(&place.into()).unwrap().1; - branches(def.variant(variant).fields.len(), def.is_enum().then_some(variant)) + branches(ecx, place, def.variant(variant).fields.len(), def.is_enum().then_some(variant)) } ty::Never diff --git a/compiler/rustc_const_eval/src/interpret/place.rs b/compiler/rustc_const_eval/src/interpret/place.rs index 8dc74035d61..31da4522a1f 100644 --- a/compiler/rustc_const_eval/src/interpret/place.rs +++ b/compiler/rustc_const_eval/src/interpret/place.rs @@ -191,7 +191,7 @@ impl<'tcx, Tag: Provenance> MPlaceTy<'tcx, Tag> { } #[inline] - pub(super) fn len(&self, cx: &impl HasDataLayout) -> InterpResult<'tcx, u64> { + pub(crate) fn len(&self, cx: &impl HasDataLayout) -> InterpResult<'tcx, u64> { if self.layout.is_unsized() { // We need to consult `meta` metadata match self.layout.ty.kind() { diff --git a/compiler/rustc_middle/src/ty/consts/valtree.rs b/compiler/rustc_middle/src/ty/consts/valtree.rs index fae22c28628..195760c0590 100644 --- a/compiler/rustc_middle/src/ty/consts/valtree.rs +++ b/compiler/rustc_middle/src/ty/consts/valtree.rs @@ -1,5 +1,5 @@ use super::ScalarInt; -use rustc_macros::HashStable; +use rustc_macros::{HashStable, TyDecodable, TyEncodable}; #[derive(Copy, Clone, Debug, Hash, TyEncodable, TyDecodable, Eq, PartialEq, Ord, PartialOrd)] #[derive(HashStable)] |