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use super::eval_queries::{mk_eval_cx, op_to_const};
use super::machine::CompileTimeEvalContext;
use super::{ValTreeCreationError, ValTreeCreationResult, VALTREE_MAX_NODES};
use crate::interpret::{
intern_const_alloc_recursive, ConstValue, ImmTy, Immediate, InternKind, MemPlaceMeta,
MemoryKind, PlaceTy, Scalar,
};
use crate::interpret::{MPlaceTy, Value};
use rustc_middle::ty::{self, ScalarInt, Ty, TyCtxt};
use rustc_span::source_map::DUMMY_SP;
use rustc_target::abi::{Align, VariantIdx};
#[instrument(skip(ecx), level = "debug")]
fn branches<'tcx>(
ecx: &CompileTimeEvalContext<'tcx, 'tcx>,
place: &MPlaceTy<'tcx>,
n: usize,
variant: Option<VariantIdx>,
num_nodes: &mut usize,
) -> ValTreeCreationResult<'tcx> {
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 mut fields = Vec::with_capacity(n);
for i in 0..n {
let field = ecx.mplace_field(&place, i).unwrap();
let valtree = const_to_valtree_inner(ecx, &field, num_nodes)?;
fields.push(Some(valtree));
}
let branches = variant
.into_iter()
.chain(fields.into_iter())
.collect::<Option<Vec<_>>>()
.expect("should have already checked for errors in ValTree creation");
if branches.len() == 0 {
*num_nodes += 1;
}
Ok(ty::ValTree::Branch(ecx.tcx.arena.alloc_from_iter(branches)))
}
#[instrument(skip(ecx), level = "debug")]
fn slice_branches<'tcx>(
ecx: &CompileTimeEvalContext<'tcx, 'tcx>,
place: &MPlaceTy<'tcx>,
num_nodes: &mut usize,
) -> ValTreeCreationResult<'tcx> {
let n = place
.len(&ecx.tcx.tcx)
.unwrap_or_else(|_| panic!("expected to use len of place {:?}", place));
let mut elems = Vec::with_capacity(n as usize);
for i in 0..n {
let place_elem = ecx.mplace_index(place, i).unwrap();
let valtree = const_to_valtree_inner(ecx, &place_elem, num_nodes)?;
elems.push(valtree);
}
Ok(ty::ValTree::Branch(ecx.tcx.arena.alloc_from_iter(elems)))
}
#[instrument(skip(ecx), level = "debug")]
pub(crate) fn const_to_valtree_inner<'tcx>(
ecx: &CompileTimeEvalContext<'tcx, 'tcx>,
place: &MPlaceTy<'tcx>,
num_nodes: &mut usize,
) -> ValTreeCreationResult<'tcx> {
let ty = place.layout.ty;
debug!("ty kind: {:?}", ty.kind());
if *num_nodes >= VALTREE_MAX_NODES {
return Err(ValTreeCreationError::NodesOverflow);
}
match ty.kind() {
ty::FnDef(..) => {
*num_nodes += 1;
Ok(ty::ValTree::zst())
}
ty::Bool | ty::Int(_) | ty::Uint(_) | ty::Float(_) | ty::Char => {
let Ok(val) = ecx.read_immediate(&place.into()) else {
return Err(ValTreeCreationError::Other);
};
let val = val.to_scalar();
*num_nodes += 1;
Ok(ty::ValTree::Leaf(val.assert_int()))
}
ty::FnPtr(_) | ty::RawPtr(_) => Err(ValTreeCreationError::NonSupportedType),
ty::Ref(_, _, _) => {
let Ok(derefd_place)= ecx.deref_operand(&place.into()) else {
return Err(ValTreeCreationError::Other);
};
debug!(?derefd_place);
const_to_valtree_inner(ecx, &derefd_place, num_nodes)
}
ty::Str | ty::Slice(_) | ty::Array(_, _) => {
slice_branches(ecx, place, num_nodes)
}
ty::Dynamic(..) => Err(ValTreeCreationError::NonSupportedType),
ty::Tuple(elem_tys) => {
branches(ecx, place, elem_tys.len(), None, num_nodes)
}
ty::Adt(def, _) => {
if def.is_union() {
return Err(ValTreeCreationError::NonSupportedType);
} else if def.variants().is_empty() {
bug!("uninhabited types should have errored and never gotten converted to valtree")
}
let Ok((_, variant)) = ecx.read_discriminant(&place.into()) else {
return Err(ValTreeCreationError::Other);
};
branches(ecx, place, def.variant(variant).fields.len(), def.is_enum().then_some(variant), num_nodes)
}
ty::Never
| 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(..) => Err(ValTreeCreationError::NonSupportedType),
}
}
#[instrument(skip(ecx), level = "debug")]
fn create_mplace_from_layout<'tcx>(
ecx: &mut CompileTimeEvalContext<'tcx, 'tcx>,
ty: Ty<'tcx>,
) -> MPlaceTy<'tcx> {
let tcx = ecx.tcx;
let param_env = ecx.param_env;
let layout = tcx.layout_of(param_env.and(ty)).unwrap();
debug!(?layout);
ecx.allocate(layout, MemoryKind::Stack).unwrap()
}
fn get_info_on_unsized_field<'tcx>(
ty: Ty<'tcx>,
valtree: ty::ValTree<'tcx>,
tcx: TyCtxt<'tcx>,
) -> (Ty<'tcx>, usize) {
let mut last_valtree = valtree;
let tail = tcx.struct_tail_with_normalize(
ty,
|ty| ty,
|| {
let branches = last_valtree.unwrap_branch();
last_valtree = branches[branches.len() - 1];
debug!(?branches, ?last_valtree);
},
);
let unsized_inner_ty = match tail.kind() {
ty::Slice(t) => *t,
ty::Str => tail,
_ => bug!("expected Slice or Str"),
};
let unsized_inner_ty = match unsized_inner_ty.kind() {
ty::Str => tcx.mk_ty(ty::Uint(ty::UintTy::U8)),
_ => unsized_inner_ty,
};
let num_elems = last_valtree.unwrap_branch().len();
(unsized_inner_ty, num_elems)
}
#[instrument(skip(ecx), level = "debug", ret)]
fn create_pointee_place<'tcx>(
ecx: &mut CompileTimeEvalContext<'tcx, 'tcx>,
ty: Ty<'tcx>,
valtree: ty::ValTree<'tcx>,
) -> MPlaceTy<'tcx> {
let tcx = ecx.tcx.tcx;
if !ty.is_sized(ecx.tcx, ty::ParamEnv::empty()) {
let (unsized_inner_ty, num_elems) = get_info_on_unsized_field(ty, valtree, tcx);
let unsized_inner_ty = match unsized_inner_ty.kind() {
ty::Str => tcx.mk_ty(ty::Uint(ty::UintTy::U8)),
_ => unsized_inner_ty,
};
let unsized_inner_ty_size =
tcx.layout_of(ty::ParamEnv::empty().and(unsized_inner_ty)).unwrap().layout.size();
debug!(?unsized_inner_ty, ?unsized_inner_ty_size, ?num_elems);
let layout = tcx.layout_of(ty::ParamEnv::empty().and(ty)).unwrap();
let size_of_sized_part = layout.layout.size();
let dst_size = unsized_inner_ty_size.checked_mul(num_elems as u64, &tcx).unwrap();
let size = size_of_sized_part.checked_add(dst_size, &tcx).unwrap();
let align = Align::from_bytes(size.bytes().next_power_of_two()).unwrap();
let ptr = ecx.allocate_ptr(size, align, MemoryKind::Stack).unwrap();
debug!(?ptr);
MPlaceTy::from_aligned_ptr_with_meta(
ptr.into(),
layout,
MemPlaceMeta::Meta(Scalar::from_machine_usize(num_elems as u64, &tcx)),
)
} else {
create_mplace_from_layout(ecx, ty)
}
}
#[instrument(skip(tcx), level = "debug", ret)]
pub fn valtree_to_const_value<'tcx>(
tcx: TyCtxt<'tcx>,
param_env_ty: ty::ParamEnvAnd<'tcx, Ty<'tcx>>,
valtree: ty::ValTree<'tcx>,
) -> ConstValue<'tcx> {
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::FnDef(..) => {
assert!(valtree.unwrap_branch().is_empty());
ConstValue::ZeroSized
}
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(_, _, _) | ty::Tuple(_) | ty::Array(_, _) | ty::Adt(..) => {
let mut place = match ty.kind() {
ty::Ref(_, inner_ty, _) => {
create_pointee_place(&mut ecx, *inner_ty, valtree)
}
_ => create_mplace_from_layout(&mut ecx, ty),
};
debug!(?place);
valtree_into_mplace(&mut ecx, &mut place, valtree);
dump_place(&ecx, place.into());
intern_const_alloc_recursive(&mut ecx, InternKind::Constant, &place).unwrap();
match ty.kind() {
ty::Ref(_, _, _) => {
let ref_place = place.to_ref(&tcx);
let imm =
ImmTy::from_immediate(ref_place, tcx.layout_of(param_env_ty).unwrap());
op_to_const(&ecx, &imm.into())
}
_ => op_to_const(&ecx, &place.into()),
}
}
ty::Never
| 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()),
}
}
#[instrument(skip(ecx), level = "debug")]
fn valtree_into_mplace<'tcx>(
ecx: &mut CompileTimeEvalContext<'tcx, 'tcx>,
place: &mut MPlaceTy<'tcx>,
valtree: ty::ValTree<'tcx>,
) {
let tcx = ecx.tcx.tcx;
let ty = place.layout.ty;
match ty.kind() {
ty::FnDef(_, _) => {
ecx.write_immediate(Immediate::Uninit, &place.into()).unwrap();
}
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(scalar_int.into()), &place.into()).unwrap();
}
ty::Ref(_, inner_ty, _) => {
let mut pointee_place = create_pointee_place(ecx, *inner_ty, valtree);
debug!(?pointee_place);
valtree_into_mplace(ecx, &mut pointee_place, valtree);
dump_place(ecx, pointee_place.into());
intern_const_alloc_recursive(ecx, InternKind::Constant, &pointee_place).unwrap();
let imm = match inner_ty.kind() {
ty::Slice(_) | ty::Str => {
let len = valtree.unwrap_branch().len();
let len_scalar = Scalar::from_machine_usize(len as u64, &tcx);
Immediate::ScalarPair(
Scalar::from_maybe_pointer((*pointee_place).ptr, &tcx),
len_scalar,
)
}
_ => pointee_place.to_ref(&tcx),
};
debug!(?imm);
ecx.write_immediate(imm, &place.into()).unwrap();
}
ty::Adt(_, _) | ty::Tuple(_) | ty::Array(_, _) | ty::Str | ty::Slice(_) => {
let branches = valtree.unwrap_branch();
let (place_adjusted, branches, variant_idx) = match ty.kind() {
ty::Adt(def, _) if def.is_enum() => {
let scalar_int = branches[0].unwrap_leaf();
let variant_idx = VariantIdx::from_u32(scalar_int.try_to_u32().unwrap());
let variant = def.variant(variant_idx);
debug!(?variant);
(
place.project_downcast(ecx, variant_idx).unwrap(),
&branches[1..],
Some(variant_idx),
)
}
_ => (*place, branches, None),
};
debug!(?place_adjusted, ?branches);
for (i, inner_valtree) in branches.iter().enumerate() {
debug!(?i, ?inner_valtree);
let mut place_inner = match ty.kind() {
ty::Str | ty::Slice(_) => ecx.mplace_index(&place, i as u64).unwrap(),
_ if !ty.is_sized(ecx.tcx, ty::ParamEnv::empty())
&& i == branches.len() - 1 =>
{
let (unsized_inner_ty, num_elems) =
get_info_on_unsized_field(ty, valtree, tcx);
debug!(?unsized_inner_ty);
let inner_ty = match ty.kind() {
ty::Adt(def, substs) => {
def.variant(VariantIdx::from_u32(0)).fields[i].ty(tcx, substs)
}
ty::Tuple(inner_tys) => inner_tys[i],
_ => bug!("unexpected unsized type {:?}", ty),
};
let inner_layout =
tcx.layout_of(ty::ParamEnv::empty().and(inner_ty)).unwrap();
debug!(?inner_layout);
let offset = place_adjusted.layout.fields.offset(i);
place
.offset_with_meta(
offset,
MemPlaceMeta::Meta(Scalar::from_machine_usize(
num_elems as u64,
&tcx,
)),
inner_layout,
&tcx,
)
.unwrap()
}
_ => ecx.mplace_field(&place_adjusted, i).unwrap(),
};
debug!(?place_inner);
valtree_into_mplace(ecx, &mut place_inner, *inner_valtree);
dump_place(&ecx, place_inner.into());
}
debug!("dump of place_adjusted:");
dump_place(ecx, place_adjusted.into());
if let Some(variant_idx) = variant_idx {
ecx.write_discriminant(variant_idx, &place.into()).unwrap();
}
debug!("dump of place after writing discriminant:");
dump_place(ecx, place.into());
}
_ => bug!("shouldn't have created a ValTree for {:?}", ty),
}
}
fn dump_place<'tcx>(ecx: &CompileTimeEvalContext<'tcx, 'tcx>, place: PlaceTy<'tcx>) {
trace!("{:?}", ecx.dump_place(*place));
}