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Rollup merge of #107533 - pnkfelix:distinguish-generator-state-in-pri…
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…nt-type-sizes, r=compiler-errors

Extend `-Z print-type-sizes` to distinguish generator upvars+locals from "normal" fields.

For example, for this code:

```rust
async fn wait() {}

async fn test(arg: [u8; 8192]) {
    wait().await;
    drop(arg);
}

async fn test_ideal(_rg: [u8; 8192]) {
    wait().await;
    // drop(arg);
}

fn main() {
    let gen_t = test([0; 8192]);
    let gen_i = test_ideal([0; 8192]);
    println!("expect {}, got: {}",
             std::mem::size_of_val(&gen_i),
             std::mem::size_of_val(&gen_t));
}
```

the `-Z print-type-sizes` output used to start with:

```
print-type-size type: `[async fn body@issue-62958-a.rs:3:32: 6:2]`: 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 type: `std::mem::ManuallyDrop<[u8; 8192]>`: 8192 bytes, alignment: 1 bytes
print-type-size     field `.value`: 8192 bytes
...
```

but with this change, it now instead prints:

```
print-type-size type: `[async fn body@issue-62958-a.rs:3:32: 6:2]`: 16386 bytes, alignment: 1 bytes
print-type-size     discriminant: 1 bytes
print-type-size     variant `Suspend0`: 16385 bytes
print-type-size         upvar `.arg`: 8192 bytes, offset: 0 bytes, alignment: 1 bytes
print-type-size         local `.arg`: 8192 bytes
print-type-size         local `.__awaitee`: 1 bytes
...
print-type-size type: `std::mem::ManuallyDrop<[u8; 8192]>`: 8192 bytes, alignment: 1 bytes
print-type-size     field `.value`: 8192 bytes
```

(spawned off of investigation of #62958 )
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@matthiaskrgr
matthiaskrgr authored Feb 1, 2023
2 parents a37a59f + 362c4fa commit f41f154
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Showing 6 changed files with 39 additions and 18 deletions.
26 changes: 22 additions & 4 deletions compiler/rustc_session/src/code_stats.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -19,8 +19,26 @@ pub enum SizeKind {
Min,
}

#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
pub enum FieldKind {
AdtField,
Upvar,
GeneratorLocal,
}

impl std::fmt::Display for FieldKind {
fn fmt(&self, w: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
match self {
FieldKind::AdtField => write!(w, "field"),
FieldKind::Upvar => write!(w, "upvar"),
FieldKind::GeneratorLocal => write!(w, "local"),
}
}
}

#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
pub struct FieldInfo {
pub kind: FieldKind,
pub name: Symbol,
pub offset: u64,
pub size: u64,
Expand Down Expand Up @@ -145,7 +163,7 @@ impl CodeStats {
fields.sort_by_key(|f| (f.offset, f.size));

for field in fields {
let FieldInfo { ref name, offset, size, align } = field;
let FieldInfo { kind, ref name, offset, size, align } = field;

if offset > min_offset {
let pad = offset - min_offset;
Expand All @@ -155,16 +173,16 @@ impl CodeStats {
if offset < min_offset {
// If this happens it's probably a union.
println!(
"print-type-size {indent}field `.{name}`: {size} bytes, \
"print-type-size {indent}{kind} `.{name}`: {size} bytes, \
offset: {offset} bytes, \
alignment: {align} bytes"
);
} else if info.packed || offset == min_offset {
println!("print-type-size {indent}field `.{name}`: {size} bytes");
println!("print-type-size {indent}{kind} `.{name}`: {size} bytes");
} else {
// Include field alignment in output only if it caused padding injection
println!(
"print-type-size {indent}field `.{name}`: {size} bytes, \
"print-type-size {indent}{kind} `.{name}`: {size} bytes, \
alignment: {align} bytes"
);
}
Expand Down
2 changes: 1 addition & 1 deletion compiler/rustc_session/src/session.rs
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Original file line number Diff line number Diff line change
@@ -1,6 +1,6 @@
use crate::cgu_reuse_tracker::CguReuseTracker;
use crate::code_stats::CodeStats;
pub use crate::code_stats::{DataTypeKind, FieldInfo, SizeKind, VariantInfo};
pub use crate::code_stats::{DataTypeKind, FieldInfo, FieldKind, SizeKind, VariantInfo};
use crate::config::Input;
use crate::config::{self, CrateType, InstrumentCoverage, OptLevel, OutputType, SwitchWithOptPath};
use crate::errors::{
Expand Down
5 changes: 4 additions & 1 deletion compiler/rustc_ty_utils/src/layout.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -9,7 +9,7 @@ use rustc_middle::ty::layout::{
use rustc_middle::ty::{
self, subst::SubstsRef, AdtDef, EarlyBinder, ReprOptions, Ty, TyCtxt, TypeVisitable,
};
use rustc_session::{DataTypeKind, FieldInfo, SizeKind, VariantInfo};
use rustc_session::{DataTypeKind, FieldInfo, FieldKind, SizeKind, VariantInfo};
use rustc_span::symbol::Symbol;
use rustc_span::DUMMY_SP;
use rustc_target::abi::*;
Expand Down Expand Up @@ -881,6 +881,7 @@ fn variant_info_for_adt<'tcx>(
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(),
Expand Down Expand Up @@ -960,6 +961,7 @@ fn variant_info_for_generator<'tcx>(
let offset = layout.fields.offset(field_idx);
upvars_size = upvars_size.max(offset + field_layout.size);
FieldInfo {
kind: FieldKind::Upvar,
name: Symbol::intern(&name),
offset: offset.bytes(),
size: field_layout.size.bytes(),
Expand All @@ -983,6 +985,7 @@ fn variant_info_for_generator<'tcx>(
// The struct is as large as the last field's end
variant_size = variant_size.max(offset + field_layout.size);
FieldInfo {
kind: FieldKind::GeneratorLocal,
name: state_specific_names.get(*local).copied().flatten().unwrap_or(
Symbol::intern(&format!(".generator_field{}", local.as_usize())),
),
Expand Down
12 changes: 6 additions & 6 deletions tests/ui/print_type_sizes/async.stdout
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Original file line number Diff line number Diff line change
@@ -1,15 +1,15 @@
print-type-size type: `[async fn body@$DIR/async.rs:8:36: 11:2]`: 16386 bytes, alignment: 1 bytes
print-type-size discriminant: 1 bytes
print-type-size variant `Suspend0`: 16385 bytes
print-type-size field `.arg`: 8192 bytes, offset: 0 bytes, alignment: 1 bytes
print-type-size field `.arg`: 8192 bytes
print-type-size field `.__awaitee`: 1 bytes
print-type-size upvar `.arg`: 8192 bytes, offset: 0 bytes, alignment: 1 bytes
print-type-size local `.arg`: 8192 bytes
print-type-size local `.__awaitee`: 1 bytes
print-type-size variant `Unresumed`: 8192 bytes
print-type-size field `.arg`: 8192 bytes, offset: 0 bytes, alignment: 1 bytes
print-type-size upvar `.arg`: 8192 bytes, offset: 0 bytes, alignment: 1 bytes
print-type-size variant `Returned`: 8192 bytes
print-type-size field `.arg`: 8192 bytes, offset: 0 bytes, alignment: 1 bytes
print-type-size upvar `.arg`: 8192 bytes, offset: 0 bytes, alignment: 1 bytes
print-type-size variant `Panicked`: 8192 bytes
print-type-size field `.arg`: 8192 bytes, offset: 0 bytes, alignment: 1 bytes
print-type-size upvar `.arg`: 8192 bytes, offset: 0 bytes, alignment: 1 bytes
print-type-size type: `std::mem::ManuallyDrop<[u8; 8192]>`: 8192 bytes, alignment: 1 bytes
print-type-size field `.value`: 8192 bytes
print-type-size type: `std::mem::MaybeUninit<[u8; 8192]>`: 8192 bytes, alignment: 1 bytes
Expand Down
8 changes: 4 additions & 4 deletions tests/ui/print_type_sizes/generator.stdout
View file
Original file line number Diff line number Diff line change
@@ -1,10 +1,10 @@
print-type-size type: `[generator@$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 upvar `.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 upvar `.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 upvar `.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
print-type-size upvar `.array`: 8192 bytes, offset: 0 bytes, alignment: 1 bytes
4 changes: 2 additions & 2 deletions tests/ui/print_type_sizes/generator_discr_placement.stdout
View file
Original file line number Diff line number Diff line change
Expand Up @@ -2,10 +2,10 @@ print-type-size type: `[generator@$DIR/generator_discr_placement.rs:11:13: 11:15
print-type-size discriminant: 1 bytes
print-type-size variant `Suspend0`: 7 bytes
print-type-size padding: 3 bytes
print-type-size field `.w`: 4 bytes, alignment: 4 bytes
print-type-size local `.w`: 4 bytes, alignment: 4 bytes
print-type-size variant `Suspend1`: 7 bytes
print-type-size padding: 3 bytes
print-type-size field `.z`: 4 bytes, alignment: 4 bytes
print-type-size local `.z`: 4 bytes, alignment: 4 bytes
print-type-size variant `Unresumed`: 0 bytes
print-type-size variant `Returned`: 0 bytes
print-type-size variant `Panicked`: 0 bytes

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