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Rollup merge of #136430 - FedericoBruzzone:follow-up-136180, r=oli-obk

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Use the type-level constant value `ty::Value` where needed

**Follow-up to #136180**

### Summary

This PR refactors functions to accept a single type-level constant value `ty::Value` instead of separate `ty::ValTree` and `ty::Ty` parameters:

- `valtree_to_const_value`: now takes `ty::Value`
- `pretty_print_const_valtree`: now takes `ty::Value`
- Uses `pretty_print_const_valtree` for formatting valtrees  when `visit_const_operand`
- Moves `try_to_raw_bytes` from `ty::Valtree` to `ty::Value`

---

r? ``@lukas-code`` ``@oli-obk``
This commit is contained in:
Matthias Krüger 2025-02-03 21:11:35 +01:00 • committed by GitHub
commit 7e0118cdd2
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7 changed files with 79 additions and 78 deletions
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42
compiler/rustc_const_eval/src/const_eval/valtrees.rs
View file

@ -273,59 +273,63 @@ pub(crate) fn eval_to_valtree<'tcx>(
/// Converts a `ValTree` to a `ConstValue`, which is needed after mir
/// construction has finished.
// FIXME(valtrees): Merge `valtree_to_const_value` and `valtree_into_mplace` into one function
// FIXME(valtrees): Accept `ty::Value` instead of `Ty` and `ty::ValTree` separately.
#[instrument(skip(tcx), level = "debug", ret)]
pub fn valtree_to_const_value<'tcx>(
tcx: TyCtxt<'tcx>,
typing_env: ty::TypingEnv<'tcx>,
ty: Ty<'tcx>,
valtree: ty::ValTree<'tcx>,
cv: ty::Value<'tcx>,
) -> mir::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?
match *ty.kind() {
// FIXME: Does this need an example?
match *cv.ty.kind() {
ty::FnDef(..) => {
assert!(valtree.unwrap_branch().is_empty());
assert!(cv.valtree.unwrap_branch().is_empty());
mir::ConstValue::ZeroSized
}
ty::Bool | ty::Int(_) | ty::Uint(_) | ty::Float(_) | ty::Char | ty::RawPtr(_, _) => {
match valtree {
match cv.valtree {
ty::ValTree::Leaf(scalar_int) => mir::ConstValue::Scalar(Scalar::Int(scalar_int)),
ty::ValTree::Branch(_) => bug!(
"ValTrees for Bool, Int, Uint, Float, Char or RawPtr should have the form ValTree::Leaf"
),
}
}
ty::Pat(ty, _) => valtree_to_const_value(tcx, typing_env, ty, valtree),
ty::Pat(ty, _) => {
let cv = ty::Value { valtree: cv.valtree, ty };
valtree_to_const_value(tcx, typing_env, cv)
}
ty::Ref(_, inner_ty, _) => {
let mut ecx =
mk_eval_cx_to_read_const_val(tcx, DUMMY_SP, typing_env, CanAccessMutGlobal::No);
let imm = valtree_to_ref(&mut ecx, valtree, inner_ty);
let imm =
ImmTy::from_immediate(imm, tcx.layout_of(typing_env.as_query_input(ty)).unwrap());
let imm = valtree_to_ref(&mut ecx, cv.valtree, inner_ty);
let imm = ImmTy::from_immediate(
imm,
tcx.layout_of(typing_env.as_query_input(cv.ty)).unwrap(),
);
op_to_const(&ecx, &imm.into(), /* for diagnostics */ false)
}
ty::Tuple(_) | ty::Array(_, _) | ty::Adt(..) => {
let layout = tcx.layout_of(typing_env.as_query_input(ty)).unwrap();
let layout = tcx.layout_of(typing_env.as_query_input(cv.ty)).unwrap();
if layout.is_zst() {
// Fast path to avoid some allocations.
return mir::ConstValue::ZeroSized;
}
if layout.backend_repr.is_scalar()
&& (matches!(ty.kind(), ty::Tuple(_))
|| matches!(ty.kind(), ty::Adt(def, _) if def.is_struct()))
&& (matches!(cv.ty.kind(), ty::Tuple(_))
|| matches!(cv.ty.kind(), ty::Adt(def, _) if def.is_struct()))
{
// A Scalar tuple/struct; we can avoid creating an allocation.
let branches = valtree.unwrap_branch();
let branches = cv.valtree.unwrap_branch();
// Find the non-ZST field. (There can be aligned ZST!)
for (i, &inner_valtree) in branches.iter().enumerate() {
let field = layout.field(&LayoutCx::new(tcx, typing_env), i);
if !field.is_zst() {
return valtree_to_const_value(tcx, typing_env, field.ty, inner_valtree);
let cv = ty::Value { valtree: inner_valtree, ty: field.ty };
return valtree_to_const_value(tcx, typing_env, cv);
}
}
bug!("could not find non-ZST field during in {layout:#?}");
@ -335,9 +339,9 @@ pub fn valtree_to_const_value<'tcx>(
mk_eval_cx_to_read_const_val(tcx, DUMMY_SP, typing_env, CanAccessMutGlobal::No);
// Need to create a place for this valtree.
let place = create_valtree_place(&mut ecx, layout, valtree);
let place = create_valtree_place(&mut ecx, layout, cv.valtree);
valtree_into_mplace(&mut ecx, &place, valtree);
valtree_into_mplace(&mut ecx, &place, cv.valtree);
dump_place(&ecx, &place);
intern_const_alloc_recursive(&mut ecx, InternKind::Constant, &place).unwrap();
@ -362,7 +366,7 @@ pub fn valtree_to_const_value<'tcx>(
| ty::Slice(_)
| ty::Dynamic(..)
| ty::UnsafeBinder(_) => {
bug!("no ValTree should have been created for type {:?}", ty.kind())
bug!("no ValTree should have been created for type {:?}", cv.ty.kind())
}
}
}

10
compiler/rustc_const_eval/src/lib.rs
View file

@ -46,14 +46,8 @@ pub fn provide(providers: &mut Providers) {
};
providers.hooks.try_destructure_mir_constant_for_user_output =
const_eval::try_destructure_mir_constant_for_user_output;
providers.valtree_to_const_val = |tcx, cv| {
const_eval::valtree_to_const_value(
tcx,
ty::TypingEnv::fully_monomorphized(),
cv.ty,
cv.valtree,
)
};
providers.valtree_to_const_val =
|tcx, cv| const_eval::valtree_to_const_value(tcx, ty::TypingEnv::fully_monomorphized(), cv);
providers.check_validity_requirement = |tcx, (init_kind, param_env_and_ty)| {
util::check_validity_requirement(tcx, init_kind, param_env_and_ty)
};