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Rollup merge of #104019 - compiler-errors:print-generator-sizes, r=wesleywiser 

Compute generator sizes with `-Zprint_type_sizes`

Fixes #103887
r? `@pnkfelix`
This commit is contained in:
Matthias Krüger 2022-12-10 09:24:41 +01:00 committed by GitHub
parent ae8794ce6a 7d23e29f9f
commit 0f5d3ba30f
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GPG Key ID: 4AEE18F83AFDEB23
10 changed files with 286 additions and 104 deletions
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68
compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs
View File

@ -27,9 +27,7 @@ use rustc_codegen_ssa::traits::*;
use rustc_fs_util::path_to_c_string;
use rustc_hir::def::CtorKind;
use rustc_hir::def_id::{DefId, LOCAL_CRATE};
use rustc_index::vec::{Idx, IndexVec};
use rustc_middle::bug;
use rustc_middle::mir::{self, GeneratorLayout};
use rustc_middle::ty::layout::{LayoutOf, TyAndLayout};
use rustc_middle::ty::subst::GenericArgKind;
use rustc_middle::ty::{
@ -1026,33 +1024,6 @@ fn build_struct_type_di_node<'ll, 'tcx>(
// Tuples
//=-----------------------------------------------------------------------------
/// Returns names of captured upvars for closures and generators.
///
/// Here are some examples:
/// - `name__field1__field2` when the upvar is captured by value.
/// - `_ref__name__field` when the upvar is captured by reference.
///
/// For generators this only contains upvars that are shared by all states.
fn closure_saved_names_of_captured_variables(tcx: TyCtxt<'_>, def_id: DefId) -> SmallVec<String> {
let body = tcx.optimized_mir(def_id);
body.var_debug_info
.iter()
.filter_map(|var| {
let is_ref = match var.value {
mir::VarDebugInfoContents::Place(place) if place.local == mir::Local::new(1) => {
// The projection is either `[.., Field, Deref]` or `[.., Field]`. It
// implies whether the variable is captured by value or by reference.
matches!(place.projection.last().unwrap(), mir::ProjectionElem::Deref)
}
_ => return None,
};
let prefix = if is_ref { "_ref__" } else { "" };
Some(prefix.to_owned() + var.name.as_str())
})
.collect()
}
/// Builds the DW_TAG_member debuginfo nodes for the upvars of a closure or generator.
/// For a generator, this will handle upvars shared by all states.
fn build_upvar_field_di_nodes<'ll, 'tcx>(
@ -1083,7 +1054,7 @@ fn build_upvar_field_di_nodes<'ll, 'tcx>(
.all(|&t| t == cx.tcx.normalize_erasing_regions(ParamEnv::reveal_all(), t))
);
let capture_names = closure_saved_names_of_captured_variables(cx.tcx, def_id);
let capture_names = cx.tcx.closure_saved_names_of_captured_variables(def_id);
let layout = cx.layout_of(closure_or_generator_ty);
up_var_tys
@ -1229,43 +1200,6 @@ fn build_union_type_di_node<'ll, 'tcx>(
)
}
// FIXME(eddyb) maybe precompute this? Right now it's computed once
// per generator monomorphization, but it doesn't depend on substs.
fn generator_layout_and_saved_local_names<'tcx>(
tcx: TyCtxt<'tcx>,
def_id: DefId,
) -> (&'tcx GeneratorLayout<'tcx>, IndexVec<mir::GeneratorSavedLocal, Option<Symbol>>) {
let body = tcx.optimized_mir(def_id);
let generator_layout = body.generator_layout().unwrap();
let mut generator_saved_local_names = IndexVec::from_elem(None, &generator_layout.field_tys);
let state_arg = mir::Local::new(1);
for var in &body.var_debug_info {
let mir::VarDebugInfoContents::Place(place) = &var.value else { continue };
if place.local != state_arg {
continue;
}
match place.projection[..] {
[
// Deref of the `Pin<&mut Self>` state argument.
mir::ProjectionElem::Field(..),
mir::ProjectionElem::Deref,
// Field of a variant of the state.
mir::ProjectionElem::Downcast(_, variant),
mir::ProjectionElem::Field(field, _),
] => {
let name = &mut generator_saved_local_names
[generator_layout.variant_fields[variant][field]];
if name.is_none() {
name.replace(var.name);
}
}
_ => {}
}
}
(generator_layout, generator_saved_local_names)
}
/// Computes the type parameters for a type, if any, for the given metadata.
fn build_generic_type_param_di_nodes<'ll, 'tcx>(
cx: &CodegenCx<'ll, 'tcx>,

8
compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/cpp_like.rs
View File

@ -22,9 +22,9 @@ use crate::{
common::CodegenCx,
debuginfo::{
metadata::{
build_field_di_node, closure_saved_names_of_captured_variables,
build_field_di_node,
enums::{tag_base_type, DiscrResult},
file_metadata, generator_layout_and_saved_local_names, size_and_align_of, type_di_node,
file_metadata, size_and_align_of, type_di_node,
type_map::{self, Stub, UniqueTypeId},
unknown_file_metadata, DINodeCreationResult, SmallVec, NO_GENERICS, NO_SCOPE_METADATA,
UNKNOWN_LINE_NUMBER,
@ -677,9 +677,9 @@ fn build_union_fields_for_direct_tag_generator<'ll, 'tcx>(
};
let (generator_layout, state_specific_upvar_names) =
generator_layout_and_saved_local_names(cx.tcx, generator_def_id);
cx.tcx.generator_layout_and_saved_local_names(generator_def_id);
let common_upvar_names = closure_saved_names_of_captured_variables(cx.tcx, generator_def_id);
let common_upvar_names = cx.tcx.closure_saved_names_of_captured_variables(generator_def_id);
let variant_range = generator_substs.variant_range(generator_def_id, cx.tcx);
let variant_count = (variant_range.start.as_u32()..variant_range.end.as_u32()).len();

7
compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/native.rs
View File

@ -4,9 +4,8 @@ use crate::{
common::CodegenCx,
debuginfo::{
metadata::{
closure_saved_names_of_captured_variables,
enums::tag_base_type,
file_metadata, generator_layout_and_saved_local_names, size_and_align_of, type_di_node,
file_metadata, size_and_align_of, type_di_node,
type_map::{self, Stub, StubInfo, UniqueTypeId},
unknown_file_metadata, DINodeCreationResult, SmallVec, NO_GENERICS,
UNKNOWN_LINE_NUMBER,
@ -157,7 +156,7 @@ pub(super) fn build_generator_di_node<'ll, 'tcx>(
),
|cx, generator_type_di_node| {
let (generator_layout, state_specific_upvar_names) =
generator_layout_and_saved_local_names(cx.tcx, generator_def_id);
cx.tcx.generator_layout_and_saved_local_names(generator_def_id);
let Variants::Multiple { tag_encoding: TagEncoding::Direct, ref variants, .. } = generator_type_and_layout.variants else {
bug!(
@ -167,7 +166,7 @@ pub(super) fn build_generator_di_node<'ll, 'tcx>(
};
let common_upvar_names =
closure_saved_names_of_captured_variables(cx.tcx, generator_def_id);
cx.tcx.closure_saved_names_of_captured_variables(generator_def_id);
// Build variant struct types
let variant_struct_type_di_nodes: SmallVec<_> = variants

76
compiler/rustc_middle/src/ty/util.rs
View File

@ -1,6 +1,7 @@
//! Miscellaneous type-system utilities that are too small to deserve their own modules.
use crate::middle::codegen_fn_attrs::CodegenFnAttrFlags;
use crate::mir;
use crate::ty::layout::IntegerExt;
use crate::ty::{
self, DefIdTree, FallibleTypeFolder, Ty, TyCtxt, TypeFoldable, TypeFolder, TypeSuperFoldable,
@ -15,6 +16,7 @@ use rustc_hir as hir;
use rustc_hir::def::{CtorOf, DefKind, Res};
use rustc_hir::def_id::DefId;
use rustc_index::bit_set::GrowableBitSet;
use rustc_index::vec::{Idx, IndexVec};
use rustc_macros::HashStable;
use rustc_span::{sym, DUMMY_SP};
use rustc_target::abi::{Integer, IntegerType, Size, TargetDataLayout};
@ -692,6 +694,80 @@ impl<'tcx> TyCtxt<'tcx> {
pub fn bound_impl_subject(self, def_id: DefId) -> ty::EarlyBinder<ty::ImplSubject<'tcx>> {
ty::EarlyBinder(self.impl_subject(def_id))
}
/// Returns names of captured upvars for closures and generators.
///
/// Here are some examples:
/// - `name__field1__field2` when the upvar is captured by value.
/// - `_ref__name__field` when the upvar is captured by reference.
///
/// For generators this only contains upvars that are shared by all states.
pub fn closure_saved_names_of_captured_variables(
self,
def_id: DefId,
) -> SmallVec<[String; 16]> {
let body = self.optimized_mir(def_id);
body.var_debug_info
.iter()
.filter_map(|var| {
let is_ref = match var.value {
mir::VarDebugInfoContents::Place(place)
if place.local == mir::Local::new(1) =>
{
// The projection is either `[.., Field, Deref]` or `[.., Field]`. It
// implies whether the variable is captured by value or by reference.
matches!(place.projection.last().unwrap(), mir::ProjectionElem::Deref)
}
_ => return None,
};
let prefix = if is_ref { "_ref__" } else { "" };
Some(prefix.to_owned() + var.name.as_str())
})
.collect()
}
// FIXME(eddyb) maybe precompute this? Right now it's computed once
// per generator monomorphization, but it doesn't depend on substs.
pub fn generator_layout_and_saved_local_names(
self,
def_id: DefId,
) -> (
&'tcx ty::GeneratorLayout<'tcx>,
IndexVec<mir::GeneratorSavedLocal, Option<rustc_span::Symbol>>,
) {
let tcx = self;
let body = tcx.optimized_mir(def_id);
let generator_layout = body.generator_layout().unwrap();
let mut generator_saved_local_names =
IndexVec::from_elem(None, &generator_layout.field_tys);
let state_arg = mir::Local::new(1);
for var in &body.var_debug_info {
let mir::VarDebugInfoContents::Place(place) = &var.value else { continue };
if place.local != state_arg {
continue;
}
match place.projection[..] {
[
// Deref of the `Pin<&mut Self>` state argument.
mir::ProjectionElem::Field(..),
mir::ProjectionElem::Deref,
// Field of a variant of the state.
mir::ProjectionElem::Downcast(_, variant),
mir::ProjectionElem::Field(field, _),
] => {
let name = &mut generator_saved_local_names
[generator_layout.variant_fields[variant][field]];
if name.is_none() {
name.replace(var.name);
}
}
_ => {}
}
}
(generator_layout, generator_saved_local_names)
}
}
struct OpaqueTypeExpander<'tcx> {

5
compiler/rustc_session/src/code_stats.rs
View File

@ -19,7 +19,7 @@ pub enum SizeKind {
Min,
}
#[derive(Clone, PartialEq, Eq, Hash, Debug)]
#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
pub struct FieldInfo {
pub name: Symbol,
pub offset: u64,
@ -33,6 +33,7 @@ pub enum DataTypeKind {
Union,
Enum,
Closure,
Generator,
}
#[derive(PartialEq, Eq, Hash, Debug)]
@ -114,7 +115,7 @@ impl CodeStats {
let struct_like = match kind {
DataTypeKind::Struct | DataTypeKind::Closure => true,
DataTypeKind::Enum | DataTypeKind::Union => false,
DataTypeKind::Enum | DataTypeKind::Union | DataTypeKind::Generator => false,
};
for (i, variant_info) in variants.into_iter().enumerate() {
let VariantInfo { ref name, kind: _, align: _, size, ref fields } = *variant_info;

145
compiler/rustc_ty_utils/src/layout.rs
View File

@ -1,3 +1,4 @@
use hir::def_id::DefId;
use rustc_hir as hir;
use rustc_index::bit_set::BitSet;
use rustc_index::vec::{Idx, IndexVec};
@ -6,7 +7,7 @@ use rustc_middle::ty::layout::{
IntegerExt, LayoutCx, LayoutError, LayoutOf, TyAndLayout, MAX_SIMD_LANES,
};
use rustc_middle::ty::{
self, subst::SubstsRef, EarlyBinder, ReprOptions, Ty, TyCtxt, TypeVisitable,
self, subst::SubstsRef, AdtDef, EarlyBinder, ReprOptions, Ty, TyCtxt, TypeVisitable,
};
use rustc_session::{DataTypeKind, FieldInfo, SizeKind, VariantInfo};
use rustc_span::symbol::Symbol;
@ -814,27 +815,39 @@ fn record_layout_for_printing_outlined<'tcx>(
);
};
let adt_def = match *layout.ty.kind() {
ty::Adt(ref adt_def, _) => {
match *layout.ty.kind() {
ty::Adt(adt_def, _) => {
debug!("print-type-size t: `{:?}` process adt", layout.ty);
adt_def
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::Generator(def_id, substs, _) => {
debug!("print-type-size t: `{:?}` record generator", layout.ty);
// Generators always have a begin/poisoned/end state with additional suspend points
let (variant_infos, opt_discr_size) =
variant_info_for_generator(cx, layout, def_id, substs);
record(DataTypeKind::Generator, false, opt_discr_size, variant_infos);
}
ty::Closure(..) => {
debug!("print-type-size t: `{:?}` record closure", layout.ty);
record(DataTypeKind::Closure, false, None, vec![]);
return;
}
_ => {
debug!("print-type-size t: `{:?}` skip non-nominal", layout.ty);
return;
}
};
}
let adt_kind = adt_def.adt_kind();
let adt_packed = adt_def.repr().pack.is_some();
fn variant_info_for_adt<'tcx>(
cx: &LayoutCx<'tcx, TyCtxt<'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
@ -843,10 +856,7 @@ fn record_layout_for_printing_outlined<'tcx>(
.map(|(i, &name)| {
let field_layout = layout.field(cx, i);
let offset = layout.fields.offset(i);
let field_end = offset + field_layout.size;
if min_size < field_end {
min_size = field_end;
}
min_size = min_size.max(offset + field_layout.size);
FieldInfo {
name,
offset: offset.bytes(),
@ -871,16 +881,9 @@ fn record_layout_for_printing_outlined<'tcx>(
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();
record(
adt_kind.into(),
adt_packed,
None,
vec![build_variant_info(Some(variant_def.name), &fields, layout)],
);
(vec![build_variant_info(Some(variant_def.name), &fields, layout)], None)
} else {
// (This case arises for *empty* enums; so give it
// zero variants.)
record(adt_kind.into(), adt_packed, None, vec![]);
(vec![], None)
}
}
@ -898,15 +901,101 @@ fn record_layout_for_printing_outlined<'tcx>(
build_variant_info(Some(variant_def.name), &fields, layout.for_variant(cx, i))
})
.collect();
record(
adt_kind.into(),
adt_packed,
(
variant_infos,
match tag_encoding {
TagEncoding::Direct => Some(tag.size(cx)),
_ => None,
},
)
}
}
}
fn variant_info_for_generator<'tcx>(
cx: &LayoutCx<'tcx, TyCtxt<'tcx>>,
layout: TyAndLayout<'tcx>,
def_id: DefId,
substs: ty::SubstsRef<'tcx>,
) -> (Vec<VariantInfo>, Option<Size>) {
let Variants::Multiple { tag, ref tag_encoding, .. } = layout.variants else {
return (vec![], None);
};
let (generator, state_specific_names) = cx.tcx.generator_layout_and_saved_local_names(def_id);
let upvar_names = cx.tcx.closure_saved_names_of_captured_variables(def_id);
let mut upvars_size = Size::ZERO;
let upvar_fields: Vec<_> = substs
.as_generator()
.upvar_tys()
.zip(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 {
name: Symbol::intern(&name),
offset: offset.bytes(),
size: field_layout.size.bytes(),
align: field_layout.align.abi.bytes(),
}
})
.collect();
let variant_infos: Vec<_> = generator
.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_layout = variant_layout.field(cx, field_idx);
let offset = variant_layout.fields.offset(field_idx);
// The struct is as large as the last field's end
variant_size = variant_size.max(offset + field_layout.size);
FieldInfo {
name: state_specific_names.get(*local).copied().flatten().unwrap_or(
Symbol::intern(&format!(".generator_field{}", local.as_usize())),
),
offset: offset.bytes(),
size: field_layout.size.bytes(),
align: field_layout.align.abi.bytes(),
}
})
.chain(upvar_fields.iter().copied())
.collect();
// If the variant has no state-specific fields, then it's the size of the upvars.
if variant_size == Size::ZERO {
variant_size = upvars_size;
}
// We need to add the discriminant size back into min_size, since it is subtracted
// later during printing.
variant_size += match tag_encoding {
TagEncoding::Direct => tag.size(cx),
_ => Size::ZERO,
};
VariantInfo {
name: Some(Symbol::intern(&ty::GeneratorSubsts::variant_name(variant_idx))),
kind: SizeKind::Exact,
size: variant_size.bytes(),
align: variant_layout.align.abi.bytes(),
fields,
}
})
.collect();
(
variant_infos,
);
}
}
match tag_encoding {
TagEncoding::Direct => Some(tag.size(cx)),
_ => None,
},
)
}

19
src/test/ui/print_type_sizes/async.rs Normal file
View File

@ -0,0 +1,19 @@
// compile-flags: -Z print-type-sizes
// edition:2021
// build-pass
// ignore-pass
#![feature(start)]
async fn wait() {}
async fn test(arg: [u8; 8192]) {
wait().await;
drop(arg);
}
#[start]
fn start(_: isize, _: *const *const u8) -> isize {
let _ = test([0; 8192]);
0
}

34
src/test/ui/print_type_sizes/async.stdout Normal file
View File

@ -0,0 +1,34 @@
print-type-size type: `[async fn body@$DIR/async.rs:10:32: 13:2]`: 16386 bytes, alignment: 1 bytes
print-type-size discriminant: 1 bytes
print-type-size variant `Suspend0`: 16385 bytes
print-type-size field `.arg`: 8192 bytes, offset: 0 bytes, alignment: 1 bytes
print-type-size field `.arg`: 8192 bytes
print-type-size field `.__awaitee`: 1 bytes
print-type-size variant `Unresumed`: 8192 bytes
print-type-size field `.arg`: 8192 bytes, offset: 0 bytes, alignment: 1 bytes
print-type-size variant `Returned`: 8192 bytes
print-type-size field `.arg`: 8192 bytes, offset: 0 bytes, alignment: 1 bytes
print-type-size variant `Panicked`: 8192 bytes
print-type-size field `.arg`: 8192 bytes, offset: 0 bytes, alignment: 1 bytes
print-type-size type: `std::mem::ManuallyDrop<[u8; 8192]>`: 8192 bytes, alignment: 1 bytes
print-type-size field `.value`: 8192 bytes
print-type-size type: `std::mem::MaybeUninit<[u8; 8192]>`: 8192 bytes, alignment: 1 bytes
print-type-size variant `MaybeUninit`: 8192 bytes
print-type-size field `.uninit`: 0 bytes
print-type-size field `.value`: 8192 bytes
print-type-size type: `[async fn body@$DIR/async.rs:8:17: 8:19]`: 1 bytes, alignment: 1 bytes
print-type-size discriminant: 1 bytes
print-type-size variant `Unresumed`: 0 bytes
print-type-size variant `Returned`: 0 bytes
print-type-size variant `Panicked`: 0 bytes
print-type-size type: `std::mem::ManuallyDrop<[async fn body@$DIR/async.rs:8:17: 8:19]>`: 1 bytes, alignment: 1 bytes
print-type-size field `.value`: 1 bytes
print-type-size type: `std::mem::MaybeUninit<[async fn body@$DIR/async.rs:8:17: 8:19]>`: 1 bytes, alignment: 1 bytes
print-type-size variant `MaybeUninit`: 1 bytes
print-type-size field `.uninit`: 0 bytes
print-type-size field `.value`: 1 bytes
print-type-size type: `std::task::Poll<()>`: 1 bytes, alignment: 1 bytes
print-type-size discriminant: 1 bytes
print-type-size variant `Ready`: 0 bytes
print-type-size field `.0`: 0 bytes
print-type-size variant `Pending`: 0 bytes

20
src/test/ui/print_type_sizes/generator.rs Normal file
View File

@ -0,0 +1,20 @@
// compile-flags: -Z print-type-sizes
// build-pass
// ignore-pass
#![feature(start, generators, generator_trait)]
use std::ops::Generator;
fn generator<const C: usize>(array: [u8; C]) -> impl Generator<Yield = (), Return = ()> {
move |()| {
yield ();
let _ = array;
}
}
#[start]
fn start(_: isize, _: *const *const u8) -> isize {
let _ = generator([0; 8192]);
0
}

10
src/test/ui/print_type_sizes/generator.stdout Normal file
View File

@ -0,0 +1,10 @@
print-type-size type: `[generator@$DIR/generator.rs:10:5: 10:14]`: 8193 bytes, alignment: 1 bytes
print-type-size discriminant: 1 bytes
print-type-size variant `Unresumed`: 8192 bytes
print-type-size field `.array`: 8192 bytes, offset: 0 bytes, alignment: 1 bytes
print-type-size variant `Returned`: 8192 bytes
print-type-size field `.array`: 8192 bytes, offset: 0 bytes, alignment: 1 bytes
print-type-size variant `Panicked`: 8192 bytes
print-type-size field `.array`: 8192 bytes, offset: 0 bytes, alignment: 1 bytes
print-type-size variant `Suspend0`: 8192 bytes
print-type-size field `.array`: 8192 bytes, offset: 0 bytes, alignment: 1 bytes