make sure ScalarPair enums have ScalarPair variants; add some layout sanity checks
This commit is contained in:
Ralf Jung
parent
8a2fe75d0e
commit
2c11c3d86c
@ -220,6 +220,91 @@ impl<'tcx> fmt::Display for LayoutError<'tcx> {
|
||||
}
|
||||
}
|
||||
|
||||
/// Enforce some basic invariants on layouts.
|
||||
fn sanity_check_layout<'tcx>(
|
||||
tcx: TyCtxt<'tcx>,
|
||||
param_env: ty::ParamEnv<'tcx>,
|
||||
layout: &TyAndLayout<'tcx>,
|
||||
) {
|
||||
// Type-level uninhabitedness should always imply ABI uninhabitedness.
|
||||
if tcx.conservative_is_privately_uninhabited(param_env.and(layout.ty)) {
|
||||
assert!(layout.abi.is_uninhabited());
|
||||
}
|
||||
|
||||
if cfg!(debug_assertions) {
|
||||
fn check_layout_abi<'tcx>(tcx: TyCtxt<'tcx>, layout: Layout<'tcx>) {
|
||||
match layout.abi() {
|
||||
Abi::Scalar(_scalar) => {
|
||||
// No padding in scalars.
|
||||
/* FIXME(#96185):
|
||||
assert_eq!(
|
||||
layout.align().abi,
|
||||
scalar.align(&tcx).abi,
|
||||
"alignment mismatch between ABI and layout in {layout:#?}"
|
||||
);
|
||||
assert_eq!(
|
||||
layout.size(),
|
||||
scalar.size(&tcx),
|
||||
"size mismatch between ABI and layout in {layout:#?}"
|
||||
);*/
|
||||
}
|
||||
Abi::ScalarPair(scalar1, scalar2) => {
|
||||
// Sanity-check scalar pair size.
|
||||
let field2_offset = scalar1.size(&tcx).align_to(scalar2.align(&tcx).abi);
|
||||
let total = field2_offset + scalar2.size(&tcx);
|
||||
assert!(
|
||||
layout.size() >= total,
|
||||
"size mismatch between ABI and layout in {layout:#?}"
|
||||
);
|
||||
}
|
||||
_ => {}
|
||||
}
|
||||
}
|
||||
|
||||
check_layout_abi(tcx, layout.layout);
|
||||
|
||||
if let Variants::Multiple { variants, .. } = &layout.variants {
|
||||
for variant in variants {
|
||||
check_layout_abi(tcx, *variant);
|
||||
// No nested "multiple".
|
||||
assert!(matches!(variant.variants(), Variants::Single { .. }));
|
||||
// Skip empty variants.
|
||||
if variant.size() == Size::ZERO
|
||||
|| variant.fields().count() == 0
|
||||
|| variant.abi().is_uninhabited()
|
||||
{
|
||||
// These are never actually accessed anyway, so we can skip them. (Note that
|
||||
// sometimes, variants with fields have size 0, and sometimes, variants without
|
||||
// fields have non-0 size.)
|
||||
continue;
|
||||
}
|
||||
// Variants should have the same or a smaller size as the full thing.
|
||||
if variant.size() > layout.size {
|
||||
bug!(
|
||||
"Type with size {} bytes has variant with size {} bytes: {layout:#?}",
|
||||
layout.size.bytes(),
|
||||
variant.size().bytes(),
|
||||
)
|
||||
}
|
||||
// The top-level ABI and the ABI of the variants should be coherent.
|
||||
let abi_coherent = match (layout.abi, variant.abi()) {
|
||||
(Abi::Scalar(..), Abi::Scalar(..)) => true,
|
||||
(Abi::ScalarPair(..), Abi::ScalarPair(..)) => true,
|
||||
(Abi::Uninhabited, _) => true,
|
||||
(Abi::Aggregate { .. }, _) => true,
|
||||
_ => false,
|
||||
};
|
||||
if !abi_coherent {
|
||||
bug!(
|
||||
"Variant ABI is incompatible with top-level ABI:\nvariant={:#?}\nTop-level: {layout:#?}",
|
||||
variant
|
||||
);
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
#[instrument(skip(tcx, query), level = "debug")]
|
||||
fn layout_of<'tcx>(
|
||||
tcx: TyCtxt<'tcx>,
|
||||
@ -263,10 +348,7 @@ fn layout_of<'tcx>(
|
||||
|
||||
cx.record_layout_for_printing(layout);
|
||||
|
||||
// Type-level uninhabitedness should always imply ABI uninhabitedness.
|
||||
if tcx.conservative_is_privately_uninhabited(param_env.and(ty)) {
|
||||
assert!(layout.abi.is_uninhabited());
|
||||
}
|
||||
sanity_check_layout(tcx, param_env, &layout);
|
||||
|
||||
Ok(layout)
|
||||
})
|
||||
@ -1313,10 +1395,22 @@ impl<'tcx> LayoutCx<'tcx, TyCtxt<'tcx>> {
|
||||
};
|
||||
let mut abi = Abi::Aggregate { sized: true };
|
||||
|
||||
// Without latter check aligned enums with custom discriminant values
|
||||
// Would result in ICE see the issue #92464 for more info
|
||||
if tag.size(dl) == size || variants.iter().all(|layout| layout.is_empty()) {
|
||||
if layout_variants.iter().all(|v| v.abi.is_uninhabited()) {
|
||||
abi = Abi::Uninhabited;
|
||||
} else if tag.size(dl) == size || variants.iter().all(|layout| layout.is_empty()) {
|
||||
// Without latter check aligned enums with custom discriminant values
|
||||
// Would result in ICE see the issue #92464 for more info
|
||||
abi = Abi::Scalar(tag);
|
||||
// Make sure the variants with fields have the same ABI as the enum itself
|
||||
// (since downcasting to them is a NOP).
|
||||
for variant in &mut layout_variants {
|
||||
if variant.fields.count() > 0
|
||||
&& matches!(variant.abi, Abi::Aggregate { .. })
|
||||
{
|
||||
assert_eq!(variant.size, size);
|
||||
variant.abi = abi;
|
||||
}
|
||||
}
|
||||
} else {
|
||||
// Try to use a ScalarPair for all tagged enums.
|
||||
let mut common_prim = None;
|
||||
@ -1385,14 +1479,21 @@ impl<'tcx> LayoutCx<'tcx, TyCtxt<'tcx>> {
|
||||
// We can use `ScalarPair` only when it matches our
|
||||
// already computed layout (including `#[repr(C)]`).
|
||||
abi = pair.abi;
|
||||
// Make sure the variants with fields have the same ABI as the enum itself
|
||||
// (since downcasting to them is a NOP).
|
||||
for variant in &mut layout_variants {
|
||||
if variant.fields.count() > 0
|
||||
&& matches!(variant.abi, Abi::Aggregate { .. })
|
||||
{
|
||||
variant.abi = abi;
|
||||
// Also need to bump up the size, so that the pair fits inside.
|
||||
variant.size = size;
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
if layout_variants.iter().all(|v| v.abi.is_uninhabited()) {
|
||||
abi = Abi::Uninhabited;
|
||||
}
|
||||
|
||||
let largest_niche = Niche::from_scalar(dl, Size::ZERO, tag);
|
||||
|
||||
let layout_variants =
|
||||
|
||||
@ -184,9 +184,22 @@ error: layout_of(std::result::Result<i32, i32>) = Layout {
|
||||
variants: Single {
|
||||
index: 0,
|
||||
},
|
||||
abi: Aggregate {
|
||||
sized: true,
|
||||
},
|
||||
abi: ScalarPair(
|
||||
Initialized {
|
||||
value: Int(
|
||||
I32,
|
||||
false,
|
||||
),
|
||||
valid_range: 0..=1,
|
||||
},
|
||||
Initialized {
|
||||
value: Int(
|
||||
I32,
|
||||
true,
|
||||
),
|
||||
valid_range: 0..=4294967295,
|
||||
},
|
||||
),
|
||||
largest_niche: None,
|
||||
align: AbiAndPrefAlign {
|
||||
abi: Align(4 bytes),
|
||||
@ -206,9 +219,22 @@ error: layout_of(std::result::Result<i32, i32>) = Layout {
|
||||
variants: Single {
|
||||
index: 1,
|
||||
},
|
||||
abi: Aggregate {
|
||||
sized: true,
|
||||
},
|
||||
abi: ScalarPair(
|
||||
Initialized {
|
||||
value: Int(
|
||||
I32,
|
||||
false,
|
||||
),
|
||||
valid_range: 0..=1,
|
||||
},
|
||||
Initialized {
|
||||
value: Int(
|
||||
I32,
|
||||
true,
|
||||
),
|
||||
valid_range: 0..=4294967295,
|
||||
},
|
||||
),
|
||||
largest_niche: None,
|
||||
align: AbiAndPrefAlign {
|
||||
abi: Align(4 bytes),
|
||||
|
||||
@ -30,9 +30,21 @@ error: layout_of(MissingPayloadField) = Layout {
|
||||
variants: Single {
|
||||
index: 0,
|
||||
},
|
||||
abi: Aggregate {
|
||||
sized: true,
|
||||
},
|
||||
abi: ScalarPair(
|
||||
Initialized {
|
||||
value: Int(
|
||||
I8,
|
||||
false,
|
||||
),
|
||||
valid_range: 0..=1,
|
||||
},
|
||||
Union {
|
||||
value: Int(
|
||||
I8,
|
||||
false,
|
||||
),
|
||||
},
|
||||
),
|
||||
largest_niche: None,
|
||||
align: AbiAndPrefAlign {
|
||||
abi: Align(1 bytes),
|
||||
@ -131,9 +143,22 @@ error: layout_of(CommonPayloadField) = Layout {
|
||||
variants: Single {
|
||||
index: 0,
|
||||
},
|
||||
abi: Aggregate {
|
||||
sized: true,
|
||||
},
|
||||
abi: ScalarPair(
|
||||
Initialized {
|
||||
value: Int(
|
||||
I8,
|
||||
false,
|
||||
),
|
||||
valid_range: 0..=1,
|
||||
},
|
||||
Initialized {
|
||||
value: Int(
|
||||
I8,
|
||||
false,
|
||||
),
|
||||
valid_range: 0..=255,
|
||||
},
|
||||
),
|
||||
largest_niche: None,
|
||||
align: AbiAndPrefAlign {
|
||||
abi: Align(1 bytes),
|
||||
@ -153,9 +178,22 @@ error: layout_of(CommonPayloadField) = Layout {
|
||||
variants: Single {
|
||||
index: 1,
|
||||
},
|
||||
abi: Aggregate {
|
||||
sized: true,
|
||||
},
|
||||
abi: ScalarPair(
|
||||
Initialized {
|
||||
value: Int(
|
||||
I8,
|
||||
false,
|
||||
),
|
||||
valid_range: 0..=1,
|
||||
},
|
||||
Initialized {
|
||||
value: Int(
|
||||
I8,
|
||||
false,
|
||||
),
|
||||
valid_range: 0..=255,
|
||||
},
|
||||
),
|
||||
largest_niche: None,
|
||||
align: AbiAndPrefAlign {
|
||||
abi: Align(1 bytes),
|
||||
@ -237,9 +275,21 @@ error: layout_of(CommonPayloadFieldIsMaybeUninit) = Layout {
|
||||
variants: Single {
|
||||
index: 0,
|
||||
},
|
||||
abi: Aggregate {
|
||||
sized: true,
|
||||
},
|
||||
abi: ScalarPair(
|
||||
Initialized {
|
||||
value: Int(
|
||||
I8,
|
||||
false,
|
||||
),
|
||||
valid_range: 0..=1,
|
||||
},
|
||||
Union {
|
||||
value: Int(
|
||||
I8,
|
||||
false,
|
||||
),
|
||||
},
|
||||
),
|
||||
largest_niche: None,
|
||||
align: AbiAndPrefAlign {
|
||||
abi: Align(1 bytes),
|
||||
@ -259,9 +309,21 @@ error: layout_of(CommonPayloadFieldIsMaybeUninit) = Layout {
|
||||
variants: Single {
|
||||
index: 1,
|
||||
},
|
||||
abi: Aggregate {
|
||||
sized: true,
|
||||
},
|
||||
abi: ScalarPair(
|
||||
Initialized {
|
||||
value: Int(
|
||||
I8,
|
||||
false,
|
||||
),
|
||||
valid_range: 0..=1,
|
||||
},
|
||||
Union {
|
||||
value: Int(
|
||||
I8,
|
||||
false,
|
||||
),
|
||||
},
|
||||
),
|
||||
largest_niche: None,
|
||||
align: AbiAndPrefAlign {
|
||||
abi: Align(1 bytes),
|
||||
|
||||
Loading…
x
Reference in New Issue
Block a user