use std::fmt::Debug;
use std::iter;
use hir::def_id::DefId;
use rustc_abi::Integer::{I8, I32};
use rustc_abi::Primitive::{self, Float, Int, Pointer};
use rustc_abi::{
AbiAndPrefAlign, AddressSpace, Align, BackendRepr, FIRST_VARIANT, FieldIdx, FieldsShape,
HasDataLayout, Layout, LayoutCalculatorError, LayoutData, Niche, ReprOptions, Scalar, Size,
StructKind, TagEncoding, VariantIdx, Variants, WrappingRange,
};
use rustc_index::bit_set::BitSet;
use rustc_index::{IndexSlice, IndexVec};
use rustc_middle::bug;
use rustc_middle::mir::{CoroutineLayout, CoroutineSavedLocal};
use rustc_middle::query::Providers;
use rustc_middle::ty::layout::{
FloatExt, HasTyCtxt, IntegerExt, LayoutCx, LayoutError, LayoutOf, MAX_SIMD_LANES, TyAndLayout,
};
use rustc_middle::ty::print::with_no_trimmed_paths;
use rustc_middle::ty::{
self, AdtDef, CoroutineArgsExt, EarlyBinder, GenericArgsRef, PseudoCanonicalInput, Ty, TyCtxt,
TypeVisitableExt,
};
use rustc_session::{DataTypeKind, FieldInfo, FieldKind, SizeKind, VariantInfo};
use rustc_span::{Symbol, sym};
use tracing::{debug, instrument, trace};
use {rustc_abi as abi, rustc_hir as hir};
use crate::errors::{
MultipleArrayFieldsSimdType, NonPrimitiveSimdType, OversizedSimdType, ZeroLengthSimdType,
};
mod invariant;
pub(crate) fn provide(providers: &mut Providers) {
*providers = Providers { layout_of, ..*providers };
}
#[instrument(skip(tcx, query), level = "debug")]
fn layout_of<'tcx>(
tcx: TyCtxt<'tcx>,
query: ty::PseudoCanonicalInput<'tcx, Ty<'tcx>>,
) -> Result<TyAndLayout<'tcx>, &'tcx LayoutError<'tcx>> {
let PseudoCanonicalInput { typing_env, value: ty } = query;
debug!(?ty);
let typing_env = typing_env.with_post_analysis_normalized(tcx);
let unnormalized_ty = ty;
let ty = match tcx.try_normalize_erasing_regions(typing_env, ty) {
Ok(t) => t,
Err(normalization_error) => {
return Err(tcx
.arena
.alloc(LayoutError::NormalizationFailure(ty, normalization_error)));
}
};
if ty != unnormalized_ty {
return tcx.layout_of(typing_env.as_query_input(ty));
}
let cx = LayoutCx::new(tcx, typing_env);
let layout = layout_of_uncached(&cx, ty)?;
let layout = TyAndLayout { ty, layout };
if cx.tcx().sess.opts.unstable_opts.print_type_sizes {
record_layout_for_printing(&cx, layout);
}
invariant::layout_sanity_check(&cx, &layout);
Ok(layout)
}
fn error<'tcx>(cx: &LayoutCx<'tcx>, err: LayoutError<'tcx>) -> &'tcx LayoutError<'tcx> {
cx.tcx().arena.alloc(err)
}
fn map_error<'tcx>(
cx: &LayoutCx<'tcx>,
ty: Ty<'tcx>,
err: LayoutCalculatorError<TyAndLayout<'tcx>>,
) -> &'tcx LayoutError<'tcx> {
let err = match err {
LayoutCalculatorError::SizeOverflow => {
LayoutError::SizeOverflow(ty)
}
LayoutCalculatorError::UnexpectedUnsized(field) => {
assert!(field.layout.is_unsized(), "invalid layout error {err:#?}");
if !field.ty.is_sized(cx.tcx(), cx.typing_env) {
cx.tcx().dcx().delayed_bug(format!(
"encountered unexpected unsized field in layout of {ty:?}: {field:#?}"
));
}
LayoutError::Unknown(ty)
}
LayoutCalculatorError::EmptyUnion => {
cx.tcx().dcx().delayed_bug(format!("computed layout of empty union: {ty:?}"));
LayoutError::Unknown(ty)
}
LayoutCalculatorError::ReprConflict => {
cx.tcx().dcx().delayed_bug(format!("computed impossible repr (packed enum?): {ty:?}"));
LayoutError::Unknown(ty)
}
};
error(cx, err)
}
fn univariant_uninterned<'tcx>(
cx: &LayoutCx<'tcx>,
ty: Ty<'tcx>,
fields: &IndexSlice<FieldIdx, TyAndLayout<'tcx>>,
repr: &ReprOptions,
kind: StructKind,
) -> Result<LayoutData<FieldIdx, VariantIdx>, &'tcx LayoutError<'tcx>> {
let pack = repr.pack;
if pack.is_some() && repr.align.is_some() {
cx.tcx().dcx().bug("struct cannot be packed and aligned");
}
cx.calc.univariant(fields, repr, kind).map_err(|err| map_error(cx, ty, err))
}
fn layout_of_uncached<'tcx>(
cx: &LayoutCx<'tcx>,
ty: Ty<'tcx>,
) -> Result<Layout<'tcx>, &'tcx LayoutError<'tcx>> {
if let Err(guar) = ty.error_reported() {
return Err(error(cx, LayoutError::ReferencesError(guar)));
}
let tcx = cx.tcx();
let dl = cx.data_layout();
let scalar_unit = |value: Primitive| {
let size = value.size(dl);
assert!(size.bits() <= 128);
Scalar::Initialized { value, valid_range: WrappingRange::full(size) }
};
let scalar = |value: Primitive| tcx.mk_layout(LayoutData::scalar(cx, scalar_unit(value)));
let univariant =
|fields: &IndexSlice<FieldIdx, TyAndLayout<'tcx>>, repr: &ReprOptions, kind| {
Ok(tcx.mk_layout(univariant_uninterned(cx, ty, fields, repr, kind)?))
};
debug_assert!(!ty.has_non_region_infer());
Ok(match *ty.kind() {
ty::Pat(ty, pat) => {
let layout = cx.layout_of(ty)?.layout;
let mut layout = LayoutData::clone(&layout.0);
match *pat {
ty::PatternKind::Range { start, end, include_end } => {
if let BackendRepr::Scalar(scalar) | BackendRepr::ScalarPair(scalar, _) =
&mut layout.backend_repr
{
if let Some(start) = start {
scalar.valid_range_mut().start = start
.try_to_bits(tcx, cx.typing_env)
.ok_or_else(|| error(cx, LayoutError::Unknown(ty)))?;
}
if let Some(end) = end {
let mut end = end
.try_to_bits(tcx, cx.typing_env)
.ok_or_else(|| error(cx, LayoutError::Unknown(ty)))?;
if !include_end {
end = end.wrapping_sub(1);
}
scalar.valid_range_mut().end = end;
}
let niche = Niche {
offset: Size::ZERO,
value: scalar.primitive(),
valid_range: scalar.valid_range(cx),
};
layout.largest_niche = Some(niche);
tcx.mk_layout(layout)
} else {
bug!("pattern type with range but not scalar layout: {ty:?}, {layout:?}")
}
}
}
}
ty::Bool => tcx.mk_layout(LayoutData::scalar(cx, Scalar::Initialized {
value: Int(I8, false),
valid_range: WrappingRange { start: 0, end: 1 },
})),
ty::Char => tcx.mk_layout(LayoutData::scalar(cx, Scalar::Initialized {
value: Int(I32, false),
valid_range: WrappingRange { start: 0, end: 0x10FFFF },
})),
ty::Int(ity) => scalar(Int(abi::Integer::from_int_ty(dl, ity), true)),
ty::Uint(ity) => scalar(Int(abi::Integer::from_uint_ty(dl, ity), false)),
ty::Float(fty) => scalar(Float(abi::Float::from_float_ty(fty))),
ty::FnPtr(..) => {
let mut ptr = scalar_unit(Pointer(dl.instruction_address_space));
ptr.valid_range_mut().start = 1;
tcx.mk_layout(LayoutData::scalar(cx, ptr))
}
ty::Never => tcx.mk_layout(cx.calc.layout_of_never_type()),
ty::Ref(_, pointee, _) | ty::RawPtr(pointee, _) => {
let mut data_ptr = scalar_unit(Pointer(AddressSpace::DATA));
if !ty.is_unsafe_ptr() {
data_ptr.valid_range_mut().start = 1;
}
let pointee = tcx.normalize_erasing_regions(cx.typing_env, pointee);
if pointee.is_sized(tcx, cx.typing_env) {
return Ok(tcx.mk_layout(LayoutData::scalar(cx, data_ptr)));
}
let metadata = if let Some(metadata_def_id) = tcx.lang_items().metadata_type()
&& !pointee.references_error()
{
let pointee_metadata = Ty::new_projection(tcx, metadata_def_id, [pointee]);
let metadata_ty =
match tcx.try_normalize_erasing_regions(cx.typing_env, pointee_metadata) {
Ok(metadata_ty) => metadata_ty,
Err(mut err) => {
match tcx.try_normalize_erasing_regions(
cx.typing_env,
tcx.struct_tail_raw(pointee, |ty| ty, || {}),
) {
Ok(_) => {}
Err(better_err) => {
err = better_err;
}
}
return Err(error(cx, LayoutError::NormalizationFailure(pointee, err)));
}
};
let metadata_layout = cx.layout_of(metadata_ty)?;
if metadata_layout.is_1zst() {
return Ok(tcx.mk_layout(LayoutData::scalar(cx, data_ptr)));
}
let BackendRepr::Scalar(metadata) = metadata_layout.backend_repr else {
return Err(error(cx, LayoutError::Unknown(pointee)));
};
metadata
} else {
let unsized_part = tcx.struct_tail_for_codegen(pointee, cx.typing_env);
match unsized_part.kind() {
ty::Foreign(..) => {
return Ok(tcx.mk_layout(LayoutData::scalar(cx, data_ptr)));
}
ty::Slice(_) | ty::Str => scalar_unit(Int(dl.ptr_sized_integer(), false)),
ty::Dynamic(..) => {
let mut vtable = scalar_unit(Pointer(AddressSpace::DATA));
vtable.valid_range_mut().start = 1;
vtable
}
_ => {
return Err(error(cx, LayoutError::Unknown(pointee)));
}
}
};
tcx.mk_layout(cx.calc.scalar_pair(data_ptr, metadata))
}
ty::Dynamic(_, _, ty::DynStar) => {
let mut data = scalar_unit(Pointer(AddressSpace::DATA));
data.valid_range_mut().start = 0;
let mut vtable = scalar_unit(Pointer(AddressSpace::DATA));
vtable.valid_range_mut().start = 1;
tcx.mk_layout(cx.calc.scalar_pair(data, vtable))
}
ty::Array(element, mut count) => {
if count.has_aliases() {
count = tcx.normalize_erasing_regions(cx.typing_env, count);
if count.has_aliases() {
return Err(error(cx, LayoutError::Unknown(ty)));
}
}
let count = count
.try_to_target_usize(tcx)
.ok_or_else(|| error(cx, LayoutError::Unknown(ty)))?;
let element = cx.layout_of(element)?;
let size = element
.size
.checked_mul(count, dl)
.ok_or_else(|| error(cx, LayoutError::SizeOverflow(ty)))?;
let abi = if count != 0 && ty.is_privately_uninhabited(tcx, cx.typing_env) {
BackendRepr::Uninhabited
} else {
BackendRepr::Memory { sized: true }
};
let largest_niche = if count != 0 { element.largest_niche } else { None };
tcx.mk_layout(LayoutData {
variants: Variants::Single { index: FIRST_VARIANT },
fields: FieldsShape::Array { stride: element.size, count },
backend_repr: abi,
largest_niche,
align: element.align,
size,
max_repr_align: None,
unadjusted_abi_align: element.align.abi,
})
}
ty::Slice(element) => {
let element = cx.layout_of(element)?;
tcx.mk_layout(LayoutData {
variants: Variants::Single { index: FIRST_VARIANT },
fields: FieldsShape::Array { stride: element.size, count: 0 },
backend_repr: BackendRepr::Memory { sized: false },
largest_niche: None,
align: element.align,
size: Size::ZERO,
max_repr_align: None,
unadjusted_abi_align: element.align.abi,
})
}
ty::Str => tcx.mk_layout(LayoutData {
variants: Variants::Single { index: FIRST_VARIANT },
fields: FieldsShape::Array { stride: Size::from_bytes(1), count: 0 },
backend_repr: BackendRepr::Memory { sized: false },
largest_niche: None,
align: dl.i8_align,
size: Size::ZERO,
max_repr_align: None,
unadjusted_abi_align: dl.i8_align.abi,
}),
ty::FnDef(..) => {
univariant(IndexSlice::empty(), &ReprOptions::default(), StructKind::AlwaysSized)?
}
ty::Dynamic(_, _, ty::Dyn) | ty::Foreign(..) => {
let mut unit = univariant_uninterned(
cx,
ty,
IndexSlice::empty(),
&ReprOptions::default(),
StructKind::AlwaysSized,
)?;
match unit.backend_repr {
BackendRepr::Memory { ref mut sized } => *sized = false,
_ => bug!(),
}
tcx.mk_layout(unit)
}
ty::Coroutine(def_id, args) => coroutine_layout(cx, ty, def_id, args)?,
ty::Closure(_, args) => {
let tys = args.as_closure().upvar_tys();
univariant(
&tys.iter().map(|ty| cx.layout_of(ty)).try_collect::<IndexVec<_, _>>()?,
&ReprOptions::default(),
StructKind::AlwaysSized,
)?
}
ty::CoroutineClosure(_, args) => {
let tys = args.as_coroutine_closure().upvar_tys();
univariant(
&tys.iter().map(|ty| cx.layout_of(ty)).try_collect::<IndexVec<_, _>>()?,
&ReprOptions::default(),
StructKind::AlwaysSized,
)?
}
ty::Tuple(tys) => {
let kind =
if tys.len() == 0 { StructKind::AlwaysSized } else { StructKind::MaybeUnsized };
univariant(
&tys.iter().map(|k| cx.layout_of(k)).try_collect::<IndexVec<_, _>>()?,
&ReprOptions::default(),
kind,
)?
}
ty::Adt(def, args) if def.repr().simd() => {
if !def.is_struct() {
tcx.dcx().delayed_bug("#[repr(simd)] was applied to an ADT that is not a struct");
return Err(error(cx, LayoutError::Unknown(ty)));
}
let fields = &def.non_enum_variant().fields;
if fields.is_empty() {
tcx.dcx().emit_fatal(ZeroLengthSimdType { ty })
}
let f0_ty = fields[FieldIdx::ZERO].ty(tcx, args);
for fi in fields {
if fi.ty(tcx, args) != f0_ty {
tcx.dcx().delayed_bug(
"#[repr(simd)] was applied to an ADT with heterogeneous field type",
);
return Err(error(cx, LayoutError::Unknown(ty)));
}
}
let (e_ty, e_len, is_array) = if let ty::Array(e_ty, _) = f0_ty.kind() {
if def.non_enum_variant().fields.len() != 1 {
tcx.dcx().emit_fatal(MultipleArrayFieldsSimdType { ty });
}
let FieldsShape::Array { count, .. } = cx.layout_of(f0_ty)?.layout.fields() else {
return Err(error(cx, LayoutError::Unknown(ty)));
};
(*e_ty, *count, true)
} else {
(f0_ty, def.non_enum_variant().fields.len() as _, false)
};
if e_len == 0 {
tcx.dcx().emit_fatal(ZeroLengthSimdType { ty });
} else if e_len > MAX_SIMD_LANES {
tcx.dcx().emit_fatal(OversizedSimdType { ty, max_lanes: MAX_SIMD_LANES });
}
let e_ly = cx.layout_of(e_ty)?;
let BackendRepr::Scalar(e_abi) = e_ly.backend_repr else {
tcx.dcx().emit_fatal(NonPrimitiveSimdType { ty, e_ty });
};
let size = e_ly
.size
.checked_mul(e_len, dl)
.ok_or_else(|| error(cx, LayoutError::SizeOverflow(ty)))?;
let (abi, align) = if def.repr().packed() && !e_len.is_power_of_two() {
(BackendRepr::Memory { sized: true }, AbiAndPrefAlign {
abi: Align::max_for_offset(size),
pref: dl.vector_align(size).pref,
})
} else {
(BackendRepr::Vector { element: e_abi, count: e_len }, dl.vector_align(size))
};
let size = size.align_to(align.abi);
let fields = if is_array {
FieldsShape::Arbitrary { offsets: [Size::ZERO].into(), memory_index: [0].into() }
} else {
FieldsShape::Array { stride: e_ly.size, count: e_len }
};
tcx.mk_layout(LayoutData {
variants: Variants::Single { index: FIRST_VARIANT },
fields,
backend_repr: abi,
largest_niche: e_ly.largest_niche,
size,
align,
max_repr_align: None,
unadjusted_abi_align: align.abi,
})
}
ty::Adt(def, args) => {
let variants = def
.variants()
.iter()
.map(|v| {
v.fields
.iter()
.map(|field| cx.layout_of(field.ty(tcx, args)))
.try_collect::<IndexVec<_, _>>()
})
.try_collect::<IndexVec<VariantIdx, _>>()?;
if def.is_union() {
if def.repr().pack.is_some() && def.repr().align.is_some() {
tcx.dcx().span_delayed_bug(
tcx.def_span(def.did()),
"union cannot be packed and aligned",
);
return Err(error(cx, LayoutError::Unknown(ty)));
}
return Ok(tcx.mk_layout(
cx.calc
.layout_of_union(&def.repr(), &variants)
.map_err(|err| map_error(cx, ty, err))?,
));
}
let get_discriminant_type =
|min, max| abi::Integer::repr_discr(tcx, ty, &def.repr(), min, max);
let discriminants_iter = || {
def.is_enum()
.then(|| def.discriminants(tcx).map(|(v, d)| (v, d.val as i128)))
.into_iter()
.flatten()
};
let dont_niche_optimize_enum = def.repr().inhibit_enum_layout_opt()
|| def
.variants()
.iter_enumerated()
.any(|(i, v)| v.discr != ty::VariantDiscr::Relative(i.as_u32()));
let maybe_unsized = def.is_struct()
&& def.non_enum_variant().tail_opt().is_some_and(|last_field| {
let typing_env = ty::TypingEnv::post_analysis(tcx, def.did());
!tcx.type_of(last_field.did).instantiate_identity().is_sized(tcx, typing_env)
});
let layout = cx
.calc
.layout_of_struct_or_enum(
&def.repr(),
&variants,
def.is_enum(),
def.is_unsafe_cell(),
tcx.layout_scalar_valid_range(def.did()),
get_discriminant_type,
discriminants_iter(),
dont_niche_optimize_enum,
!maybe_unsized,
)
.map_err(|err| map_error(cx, ty, err))?;
if !maybe_unsized && layout.is_unsized() {
bug!("got unsized layout for type that cannot be unsized {ty:?}: {layout:#?}");
}
if cfg!(debug_assertions)
&& maybe_unsized
&& def.non_enum_variant().tail().ty(tcx, args).is_sized(tcx, cx.typing_env)
{
let mut variants = variants;
let tail_replacement = cx.layout_of(Ty::new_slice(tcx, tcx.types.u8)).unwrap();
*variants[FIRST_VARIANT].raw.last_mut().unwrap() = tail_replacement;
let Ok(unsized_layout) = cx.calc.layout_of_struct_or_enum(
&def.repr(),
&variants,
def.is_enum(),
def.is_unsafe_cell(),
tcx.layout_scalar_valid_range(def.did()),
get_discriminant_type,
discriminants_iter(),
dont_niche_optimize_enum,
!maybe_unsized,
) else {
bug!("failed to compute unsized layout of {ty:?}");
};
let FieldsShape::Arbitrary { offsets: sized_offsets, .. } = &layout.fields else {
bug!("unexpected FieldsShape for sized layout of {ty:?}: {:?}", layout.fields);
};
let FieldsShape::Arbitrary { offsets: unsized_offsets, .. } =
&unsized_layout.fields
else {
bug!(
"unexpected FieldsShape for unsized layout of {ty:?}: {:?}",
unsized_layout.fields
);
};
let (sized_tail, sized_fields) = sized_offsets.raw.split_last().unwrap();
let (unsized_tail, unsized_fields) = unsized_offsets.raw.split_last().unwrap();
if sized_fields != unsized_fields {
bug!("unsizing {ty:?} changed field order!\n{layout:?}\n{unsized_layout:?}");
}
if sized_tail < unsized_tail {
bug!("unsizing {ty:?} moved tail backwards!\n{layout:?}\n{unsized_layout:?}");
}
}
tcx.mk_layout(layout)
}
ty::Alias(..) => {
return Err(error(cx, LayoutError::Unknown(ty)));
}
ty::Bound(..) | ty::CoroutineWitness(..) | ty::Infer(_) | ty::Error(_) => {
bug!("Layout::compute: unexpected type `{}`", ty)
}
ty::Placeholder(..) | ty::Param(_) => {
return Err(error(cx, LayoutError::Unknown(ty)));
}
})
}
#[derive(Clone, Debug, PartialEq)]
enum SavedLocalEligibility {
Unassigned,
Assigned(VariantIdx),
Ineligible(Option<FieldIdx>),
}
fn coroutine_saved_local_eligibility(
info: &CoroutineLayout<'_>,
) -> (BitSet<CoroutineSavedLocal>, IndexVec<CoroutineSavedLocal, SavedLocalEligibility>) {
use SavedLocalEligibility::*;
let mut assignments: IndexVec<CoroutineSavedLocal, SavedLocalEligibility> =
IndexVec::from_elem(Unassigned, &info.field_tys);
let mut ineligible_locals = BitSet::new_empty(info.field_tys.len());
for (variant_index, fields) in info.variant_fields.iter_enumerated() {
for local in fields {
match assignments[*local] {
Unassigned => {
assignments[*local] = Assigned(variant_index);
}
Assigned(idx) => {
trace!(
"removing local {:?} in >1 variant ({:?}, {:?})",
local, variant_index, idx
);
ineligible_locals.insert(*local);
assignments[*local] = Ineligible(None);
}
Ineligible(_) => {}
}
}
}
for local_a in info.storage_conflicts.rows() {
let conflicts_a = info.storage_conflicts.count(local_a);
if ineligible_locals.contains(local_a) {
continue;
}
for local_b in info.storage_conflicts.iter(local_a) {
if ineligible_locals.contains(local_b) || assignments[local_a] == assignments[local_b] {
continue;
}
let conflicts_b = info.storage_conflicts.count(local_b);
let (remove, other) =
if conflicts_a > conflicts_b { (local_a, local_b) } else { (local_b, local_a) };
ineligible_locals.insert(remove);
assignments[remove] = Ineligible(None);
trace!("removing local {:?} due to conflict with {:?}", remove, other);
}
}
{
let mut used_variants = BitSet::new_empty(info.variant_fields.len());
for assignment in &assignments {
if let Assigned(idx) = assignment {
used_variants.insert(*idx);
}
}
if used_variants.count() < 2 {
for assignment in assignments.iter_mut() {
*assignment = Ineligible(None);
}
ineligible_locals.insert_all();
}
}
{
for (idx, local) in ineligible_locals.iter().enumerate() {
assignments[local] = Ineligible(Some(FieldIdx::from_usize(idx)));
}
}
debug!("coroutine saved local assignments: {:?}", assignments);
(ineligible_locals, assignments)
}
fn coroutine_layout<'tcx>(
cx: &LayoutCx<'tcx>,
ty: Ty<'tcx>,
def_id: hir::def_id::DefId,
args: GenericArgsRef<'tcx>,
) -> Result<Layout<'tcx>, &'tcx LayoutError<'tcx>> {
use SavedLocalEligibility::*;
let tcx = cx.tcx();
let instantiate_field = |ty: Ty<'tcx>| EarlyBinder::bind(ty).instantiate(tcx, args);
let Some(info) = tcx.coroutine_layout(def_id, args.as_coroutine().kind_ty()) else {
return Err(error(cx, LayoutError::Unknown(ty)));
};
let (ineligible_locals, assignments) = coroutine_saved_local_eligibility(info);
let tag_index = args.as_coroutine().prefix_tys().len();
let max_discr = (info.variant_fields.len() - 1) as u128;
let discr_int = abi::Integer::fit_unsigned(max_discr);
let tag = Scalar::Initialized {
value: Primitive::Int(discr_int, false),
valid_range: WrappingRange { start: 0, end: max_discr },
};
let tag_layout = TyAndLayout {
ty: discr_int.to_ty(tcx, false),
layout: tcx.mk_layout(LayoutData::scalar(cx, tag)),
};
let promoted_layouts = ineligible_locals.iter().map(|local| {
let field_ty = instantiate_field(info.field_tys[local].ty);
let uninit_ty = Ty::new_maybe_uninit(tcx, field_ty);
cx.spanned_layout_of(uninit_ty, info.field_tys[local].source_info.span)
});
let prefix_layouts = args
.as_coroutine()
.prefix_tys()
.iter()
.map(|ty| cx.layout_of(ty))
.chain(iter::once(Ok(tag_layout)))
.chain(promoted_layouts)
.try_collect::<IndexVec<_, _>>()?;
let prefix = univariant_uninterned(
cx,
ty,
&prefix_layouts,
&ReprOptions::default(),
StructKind::AlwaysSized,
)?;
let (prefix_size, prefix_align) = (prefix.size, prefix.align);
debug!("prefix = {:#?}", prefix);
let (outer_fields, promoted_offsets, promoted_memory_index) = match prefix.fields {
FieldsShape::Arbitrary { mut offsets, memory_index } => {
let mut inverse_memory_index = memory_index.invert_bijective_mapping();
let b_start = FieldIdx::from_usize(tag_index + 1);
let offsets_b = IndexVec::from_raw(offsets.raw.split_off(b_start.as_usize()));
let offsets_a = offsets;
let inverse_memory_index_b: IndexVec<u32, FieldIdx> = inverse_memory_index
.iter()
.filter_map(|&i| i.as_u32().checked_sub(b_start.as_u32()).map(FieldIdx::from_u32))
.collect();
inverse_memory_index.raw.retain(|&i| i < b_start);
let inverse_memory_index_a = inverse_memory_index;
let memory_index_a = inverse_memory_index_a.invert_bijective_mapping();
let memory_index_b = inverse_memory_index_b.invert_bijective_mapping();
let outer_fields =
FieldsShape::Arbitrary { offsets: offsets_a, memory_index: memory_index_a };
(outer_fields, offsets_b, memory_index_b)
}
_ => bug!(),
};
let mut size = prefix.size;
let mut align = prefix.align;
let variants = info
.variant_fields
.iter_enumerated()
.map(|(index, variant_fields)| {
let variant_only_tys = variant_fields
.iter()
.filter(|local| match assignments[**local] {
Unassigned => bug!(),
Assigned(v) if v == index => true,
Assigned(_) => bug!("assignment does not match variant"),
Ineligible(_) => false,
})
.map(|local| {
let field_ty = instantiate_field(info.field_tys[*local].ty);
Ty::new_maybe_uninit(tcx, field_ty)
});
let mut variant = univariant_uninterned(
cx,
ty,
&variant_only_tys.map(|ty| cx.layout_of(ty)).try_collect::<IndexVec<_, _>>()?,
&ReprOptions::default(),
StructKind::Prefixed(prefix_size, prefix_align.abi),
)?;
variant.variants = Variants::Single { index };
let FieldsShape::Arbitrary { offsets, memory_index } = variant.fields else {
bug!();
};
const INVALID_FIELD_IDX: FieldIdx = FieldIdx::MAX;
debug_assert!(variant_fields.next_index() <= INVALID_FIELD_IDX);
let mut combined_inverse_memory_index = IndexVec::from_elem_n(
INVALID_FIELD_IDX,
promoted_memory_index.len() + memory_index.len(),
);
let mut offsets_and_memory_index = iter::zip(offsets, memory_index);
let combined_offsets = variant_fields
.iter_enumerated()
.map(|(i, local)| {
let (offset, memory_index) = match assignments[*local] {
Unassigned => bug!(),
Assigned(_) => {
let (offset, memory_index) = offsets_and_memory_index.next().unwrap();
(offset, promoted_memory_index.len() as u32 + memory_index)
}
Ineligible(field_idx) => {
let field_idx = field_idx.unwrap();
(promoted_offsets[field_idx], promoted_memory_index[field_idx])
}
};
combined_inverse_memory_index[memory_index] = i;
offset
})
.collect();
combined_inverse_memory_index.raw.retain(|&i| i != INVALID_FIELD_IDX);
let combined_memory_index = combined_inverse_memory_index.invert_bijective_mapping();
variant.fields = FieldsShape::Arbitrary {
offsets: combined_offsets,
memory_index: combined_memory_index,
};
size = size.max(variant.size);
align = align.max(variant.align);
Ok(variant)
})
.try_collect::<IndexVec<VariantIdx, _>>()?;
size = size.align_to(align.abi);
let abi = if prefix.backend_repr.is_uninhabited()
|| variants.iter().all(|v| v.backend_repr.is_uninhabited())
{
BackendRepr::Uninhabited
} else {
BackendRepr::Memory { sized: true }
};
let layout = tcx.mk_layout(LayoutData {
variants: Variants::Multiple {
tag,
tag_encoding: TagEncoding::Direct,
tag_field: tag_index,
variants,
},
fields: outer_fields,
backend_repr: abi,
largest_niche: None,
size,
align,
max_repr_align: None,
unadjusted_abi_align: align.abi,
});
debug!("coroutine layout ({:?}): {:#?}", ty, layout);
Ok(layout)
}
fn record_layout_for_printing<'tcx>(cx: &LayoutCx<'tcx>, layout: TyAndLayout<'tcx>) {
if layout.ty.has_non_region_param() || !cx.typing_env.param_env.caller_bounds().is_empty() {
return;
}
let record = |kind, packed, opt_discr_size, variants| {
let type_desc = with_no_trimmed_paths!(format!("{}", layout.ty));
cx.tcx().sess.code_stats.record_type_size(
kind,
type_desc,
layout.align.abi,
layout.size,
packed,
opt_discr_size,
variants,
);
};
match *layout.ty.kind() {
ty::Adt(adt_def, _) => {
debug!("print-type-size t: `{:?}` process adt", layout.ty);
let adt_kind = adt_def.adt_kind();
let adt_packed = adt_def.repr().pack.is_some();
let (variant_infos, opt_discr_size) = variant_info_for_adt(cx, layout, adt_def);
record(adt_kind.into(), adt_packed, opt_discr_size, variant_infos);
}
ty::Coroutine(def_id, args) => {
debug!("print-type-size t: `{:?}` record coroutine", layout.ty);
let (variant_infos, opt_discr_size) =
variant_info_for_coroutine(cx, layout, def_id, args);
record(DataTypeKind::Coroutine, false, opt_discr_size, variant_infos);
}
ty::Closure(..) => {
debug!("print-type-size t: `{:?}` record closure", layout.ty);
record(DataTypeKind::Closure, false, None, vec![]);
}
_ => {
debug!("print-type-size t: `{:?}` skip non-nominal", layout.ty);
}
};
}
fn variant_info_for_adt<'tcx>(
cx: &LayoutCx<'tcx>,
layout: TyAndLayout<'tcx>,
adt_def: AdtDef<'tcx>,
) -> (Vec<VariantInfo>, Option<Size>) {
let build_variant_info = |n: Option<Symbol>, flds: &[Symbol], layout: TyAndLayout<'tcx>| {
let mut min_size = Size::ZERO;
let field_info: Vec<_> = flds
.iter()
.enumerate()
.map(|(i, &name)| {
let field_layout = layout.field(cx, i);
let offset = layout.fields.offset(i);
min_size = min_size.max(offset + field_layout.size);
FieldInfo {
kind: FieldKind::AdtField,
name,
offset: offset.bytes(),
size: field_layout.size.bytes(),
align: field_layout.align.abi.bytes(),
type_name: None,
}
})
.collect();
VariantInfo {
name: n,
kind: if layout.is_unsized() { SizeKind::Min } else { SizeKind::Exact },
align: layout.align.abi.bytes(),
size: if min_size.bytes() == 0 { layout.size.bytes() } else { min_size.bytes() },
fields: field_info,
}
};
match layout.variants {
Variants::Empty => (vec![], None),
Variants::Single { index } => {
debug!("print-type-size `{:#?}` variant {}", layout, adt_def.variant(index).name);
let variant_def = &adt_def.variant(index);
let fields: Vec<_> = variant_def.fields.iter().map(|f| f.name).collect();
(vec![build_variant_info(Some(variant_def.name), &fields, layout)], None)
}
Variants::Multiple { tag, ref tag_encoding, .. } => {
debug!(
"print-type-size `{:#?}` adt general variants def {}",
layout.ty,
adt_def.variants().len()
);
let variant_infos: Vec<_> = adt_def
.variants()
.iter_enumerated()
.map(|(i, variant_def)| {
let fields: Vec<_> = variant_def.fields.iter().map(|f| f.name).collect();
build_variant_info(Some(variant_def.name), &fields, layout.for_variant(cx, i))
})
.collect();
(variant_infos, match tag_encoding {
TagEncoding::Direct => Some(tag.size(cx)),
_ => None,
})
}
}
}
fn variant_info_for_coroutine<'tcx>(
cx: &LayoutCx<'tcx>,
layout: TyAndLayout<'tcx>,
def_id: DefId,
args: ty::GenericArgsRef<'tcx>,
) -> (Vec<VariantInfo>, Option<Size>) {
use itertools::Itertools;
let Variants::Multiple { tag, ref tag_encoding, tag_field, .. } = layout.variants else {
return (vec![], None);
};
let coroutine = cx.tcx().coroutine_layout(def_id, args.as_coroutine().kind_ty()).unwrap();
let upvar_names = cx.tcx().closure_saved_names_of_captured_variables(def_id);
let mut upvars_size = Size::ZERO;
let upvar_fields: Vec<_> = args
.as_coroutine()
.upvar_tys()
.iter()
.zip_eq(upvar_names)
.enumerate()
.map(|(field_idx, (_, name))| {
let field_layout = layout.field(cx, field_idx);
let offset = layout.fields.offset(field_idx);
upvars_size = upvars_size.max(offset + field_layout.size);
FieldInfo {
kind: FieldKind::Upvar,
name: *name,
offset: offset.bytes(),
size: field_layout.size.bytes(),
align: field_layout.align.abi.bytes(),
type_name: None,
}
})
.collect();
let mut variant_infos: Vec<_> = coroutine
.variant_fields
.iter_enumerated()
.map(|(variant_idx, variant_def)| {
let variant_layout = layout.for_variant(cx, variant_idx);
let mut variant_size = Size::ZERO;
let fields = variant_def
.iter()
.enumerate()
.map(|(field_idx, local)| {
let field_name = coroutine.field_names[*local];
let field_layout = variant_layout.field(cx, field_idx);
let offset = variant_layout.fields.offset(field_idx);
variant_size = variant_size.max(offset + field_layout.size);
FieldInfo {
kind: FieldKind::CoroutineLocal,
name: field_name.unwrap_or(Symbol::intern(&format!(
".coroutine_field{}",
local.as_usize()
))),
offset: offset.bytes(),
size: field_layout.size.bytes(),
align: field_layout.align.abi.bytes(),
type_name: (field_name.is_none() || field_name == Some(sym::__awaitee))
.then(|| Symbol::intern(&field_layout.ty.to_string())),
}
})
.chain(upvar_fields.iter().copied())
.collect();
if variant_size == Size::ZERO {
variant_size = upvars_size;
}
if layout.fields.offset(tag_field) >= variant_size {
variant_size += match tag_encoding {
TagEncoding::Direct => tag.size(cx),
_ => Size::ZERO,
};
}
VariantInfo {
name: Some(Symbol::intern(&ty::CoroutineArgs::variant_name(variant_idx))),
kind: SizeKind::Exact,
size: variant_size.bytes(),
align: variant_layout.align.abi.bytes(),
fields,
}
})
.collect();
let end_states = variant_infos.drain(1..=2);
let end_states: Vec<_> = end_states.collect();
variant_infos.extend(end_states);
(variant_infos, match tag_encoding {
TagEncoding::Direct => Some(tag.size(cx)),
_ => None,
})
}