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Update directly tagged enums to visualize the same as niche-layout enums

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Previously, directly tagged enums had a `variant$` field which would
show the name of the active variant. We now show the variant using a
`[variant]` synthetic item just like we do for niche-layout enums.
This commit is contained in:
Wesley Wiser 2021-06-24 16:37:03 -04:00
parent 798baebde1
commit 3780684f5a
4 changed files with 61 additions and 95 deletions
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123
compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs
View File

@ -1,4 +1,3 @@
use self::EnumTagInfo::*;
use self::MemberDescriptionFactory::*;
use self::RecursiveTypeDescription::*;
@ -28,7 +27,7 @@
use rustc_hir::def_id::{DefId, LOCAL_CRATE};
use rustc_index::vec::{Idx, IndexVec};
use rustc_middle::ich::NodeIdHashingMode;
use rustc_middle::mir::{self, Field, GeneratorLayout};
use rustc_middle::mir::{self, GeneratorLayout};
use rustc_middle::ty::layout::{self, IntegerExt, PrimitiveExt, TyAndLayout};
use rustc_middle::ty::subst::GenericArgKind;
use rustc_middle::ty::Instance;
@ -1188,7 +1187,7 @@ enum MemberDescriptionFactory<'ll, 'tcx> {
TupleMDF(TupleMemberDescriptionFactory<'tcx>),
EnumMDF(EnumMemberDescriptionFactory<'ll, 'tcx>),
UnionMDF(UnionMemberDescriptionFactory<'tcx>),
VariantMDF(VariantMemberDescriptionFactory<'ll, 'tcx>),
VariantMDF(VariantMemberDescriptionFactory<'tcx>),
}
impl MemberDescriptionFactory<'ll, 'tcx> {
@ -1505,14 +1504,8 @@ fn create_member_descriptions(&self, cx: &CodegenCx<'ll, 'tcx>) -> Vec<MemberDes
}
let variant_info = variant_info_for(index);
let (variant_type_metadata, member_description_factory) = describe_enum_variant(
cx,
self.layout,
variant_info,
None,
self_metadata,
self.span,
);
let (variant_type_metadata, member_description_factory) =
describe_enum_variant(cx, self.layout, variant_info, self_metadata, self.span);
let member_descriptions = member_description_factory.create_member_descriptions(cx);
@ -1540,28 +1533,38 @@ fn create_member_descriptions(&self, cx: &CodegenCx<'ll, 'tcx>) -> Vec<MemberDes
ref variants,
..
} => {
let tag_info = if fallback {
// For MSVC, we generate a union of structs for each variant with an explicit
// discriminant field roughly equivalent to the following C:
let fallback_discr_variant = if fallback {
// For MSVC, we generate a union of structs for each variant and an
// explicit discriminant field roughly equivalent to the following C:
// ```c
// union enum$<{name}> {
// struct {variant 0 name} {
// tag$ variant$;
// <variant 0 fields>
// } variant0;
// <other variant structs>
// {name} discriminant;
// }
// ```
// The natvis in `intrinsic.nativs` then matches on `this.variant0.variant$` to
// The natvis in `intrinsic.nativs` then matches on `this.discriminant` to
// determine which variant is active and then displays it.
Some(DirectTag {
tag_field: Field::from(tag_field),
tag_type_metadata: self.tag_type_metadata.unwrap(),
let enum_layout = self.layout;
let offset = enum_layout.fields.offset(tag_field);
let discr_ty = enum_layout.field(cx, tag_field).ty;
let (size, align) = cx.size_and_align_of(discr_ty);
Some(MemberDescription {
name: "discriminant".into(),
type_metadata: self.tag_type_metadata.unwrap(),
offset,
size,
align,
flags: DIFlags::FlagZero,
discriminant: None,
source_info: None,
})
} else {
// This doesn't matter in this case.
None
};
variants
.iter_enumerated()
.map(|(i, _)| {
@ -1571,7 +1574,6 @@ fn create_member_descriptions(&self, cx: &CodegenCx<'ll, 'tcx>) -> Vec<MemberDes
cx,
variant,
variant_info,
tag_info,
self_metadata,
self.span,
);
@ -1605,6 +1607,7 @@ fn create_member_descriptions(&self, cx: &CodegenCx<'ll, 'tcx>) -> Vec<MemberDes
source_info: variant_info.source_info(cx),
}
})
.chain(fallback_discr_variant.into_iter())
.collect()
}
Variants::Multiple {
@ -1702,7 +1705,6 @@ fn create_member_descriptions(&self, cx: &CodegenCx<'ll, 'tcx>) -> Vec<MemberDes
cx,
dataful_variant_layout,
variant_info,
Some(NicheTag),
self_metadata,
self.span,
);
@ -1754,7 +1756,6 @@ fn create_member_descriptions(&self, cx: &CodegenCx<'ll, 'tcx>) -> Vec<MemberDes
cx,
variant,
variant_info,
Some(NicheTag),
self_metadata,
self.span,
);
@ -1791,39 +1792,27 @@ fn create_member_descriptions(&self, cx: &CodegenCx<'ll, 'tcx>) -> Vec<MemberDes
}
// Creates `MemberDescription`s for the fields of a single enum variant.
struct VariantMemberDescriptionFactory<'ll, 'tcx> {
struct VariantMemberDescriptionFactory<'tcx> {
/// Cloned from the `layout::Struct` describing the variant.
offsets: Vec<Size>,
args: Vec<(String, Ty<'tcx>)>,
tag_type_metadata: Option<&'ll DIType>,
span: Span,
}
impl VariantMemberDescriptionFactory<'ll, 'tcx> {
impl VariantMemberDescriptionFactory<'tcx> {
fn create_member_descriptions(&self, cx: &CodegenCx<'ll, 'tcx>) -> Vec<MemberDescription<'ll>> {
self.args
.iter()
.enumerate()
.map(|(i, &(ref name, ty))| {
// Discriminant is always the first field of our variant
// when using the enum fallback.
let is_artificial_discr = use_enum_fallback(cx) && i == 0;
let (size, align) = cx.size_and_align_of(ty);
MemberDescription {
name: name.to_string(),
type_metadata: if is_artificial_discr {
self.tag_type_metadata.unwrap_or_else(|| type_metadata(cx, ty, self.span))
} else {
type_metadata(cx, ty, self.span)
},
type_metadata: type_metadata(cx, ty, self.span),
offset: self.offsets[i],
size,
align,
flags: if is_artificial_discr {
DIFlags::FlagArtificial
} else {
DIFlags::FlagZero
},
flags: DIFlags::FlagZero,
discriminant: None,
source_info: None,
}
@ -1832,12 +1821,6 @@ fn create_member_descriptions(&self, cx: &CodegenCx<'ll, 'tcx>) -> Vec<MemberDes
}
}
#[derive(Copy, Clone)]
enum EnumTagInfo<'ll> {
DirectTag { tag_field: Field, tag_type_metadata: &'ll DIType },
NicheTag,
}
#[derive(Copy, Clone)]
enum VariantInfo<'a, 'tcx> {
Adt(&'tcx ty::VariantDef),
@ -1916,7 +1899,6 @@ fn describe_enum_variant(
cx: &CodegenCx<'ll, 'tcx>,
layout: layout::TyAndLayout<'tcx>,
variant: VariantInfo<'_, 'tcx>,
discriminant_info: Option<EnumTagInfo<'ll>>,
containing_scope: &'ll DIScope,
span: Span,
) -> (&'ll DICompositeType, MemberDescriptionFactory<'ll, 'tcx>) {
@ -1935,50 +1917,13 @@ fn describe_enum_variant(
)
});
// Build an array of (field name, field type) pairs to be captured in the factory closure.
let (offsets, args) = if use_enum_fallback(cx) {
// If this is not a univariant enum, there is also the discriminant field.
let (discr_offset, discr_arg) = match discriminant_info {
Some(DirectTag { tag_field, .. }) => {
// We have the layout of an enum variant, we need the layout of the outer enum
let enum_layout = cx.layout_of(layout.ty);
let offset = enum_layout.fields.offset(tag_field.as_usize());
let args = ("variant$".to_owned(), enum_layout.field(cx, tag_field.as_usize()).ty);
(Some(offset), Some(args))
}
_ => (None, None),
};
(
discr_offset
.into_iter()
.chain((0..layout.fields.count()).map(|i| layout.fields.offset(i)))
.collect(),
discr_arg
.into_iter()
.chain(
(0..layout.fields.count())
.map(|i| (variant.field_name(i), layout.field(cx, i).ty)),
)
.collect(),
)
} else {
(
(0..layout.fields.count()).map(|i| layout.fields.offset(i)).collect(),
(0..layout.fields.count())
.map(|i| (variant.field_name(i), layout.field(cx, i).ty))
.collect(),
)
};
let offsets = (0..layout.fields.count()).map(|i| layout.fields.offset(i)).collect();
let args = (0..layout.fields.count())
.map(|i| (variant.field_name(i), layout.field(cx, i).ty))
.collect();
let member_description_factory = VariantMDF(VariantMemberDescriptionFactory {
offsets,
args,
tag_type_metadata: match discriminant_info {
Some(DirectTag { tag_type_metadata, .. }) => Some(tag_type_metadata),
_ => None,
},
span,
});
let member_description_factory =
VariantMDF(VariantMemberDescriptionFactory { offsets, args, span });
(metadata_stub, member_description_factory)
}

5
src/etc/natvis/intrinsic.natvis
View File

@ -150,7 +150,7 @@
</Expand>
</Type>
<Type Name="enum$&lt;*&gt;">
<Intrinsic Name="tag" Expression="variant0.variant$" />
<Intrinsic Name="tag" Expression="discriminant" />
<DisplayString Condition="tag() == 0">{tag(),en}</DisplayString>
<DisplayString Condition="tag() == 1" Optional="true">{tag(),en}</DisplayString>
<DisplayString Condition="tag() == 2" Optional="true">{tag(),en}</DisplayString>
@ -169,6 +169,9 @@
<DisplayString Condition="tag() == 15" Optional="true">{tag(),en}</DisplayString>
<Expand>
<Synthetic Name="[variant]">
<DisplayString>{tag(),en}</DisplayString>
</Synthetic>
<ExpandedItem Condition="tag() == 0">variant0</ExpandedItem>
<ExpandedItem Condition="tag() == 1" Optional="true">variant1</ExpandedItem>
<ExpandedItem Condition="tag() == 2" Optional="true">variant2</ExpandedItem>

20
src/test/debuginfo/msvc-pretty-enums.rs
View File

@ -48,14 +48,30 @@
// cdb-check: [+0x000] __0 : 0x0 [Type: unsigned int *]
// cdb-check: [+0x000] discriminant : None (0x0) [Type: enum$<core::option::Option<ref$<u32> >, 1, [...], Some>::Discriminant$]
// cdb-command: dx -r2 h,!
// cdb-check:h,! : Some [Type: enum$<core::option::Option<u32> >]
// cdb-check: [+0x000] variant0 [Type: enum$<core::option::Option<u32> >::None]
// cdb-check: [+0x000] variant1 [Type: enum$<core::option::Option<u32> >::Some]
// cdb-check: [+0x004] __0 : 0xc [Type: unsigned int]
// cdb-check: [+0x000] discriminant : Some (0x1) [Type: core::option::Option]
// cdb-command: dx h
// cdb-check:h : Some [Type: enum$<core::option::Option<u32> >]
// cdb-check: [+0x000] variant$ : Some (0x1) [Type: core::option::Option]
// cdb-check: [<Raw View>] [Type: enum$<core::option::Option<u32> >]
// cdb-check: [variant] : Some
// cdb-check: [+0x004] __0 : 0xc [Type: unsigned int]
// cdb-command: dx -r2 i,!
// cdb-check:i,! : None [Type: enum$<core::option::Option<u32> >]
// cdb-check: [+0x000] variant0 [Type: enum$<core::option::Option<u32> >::None]
// cdb-check: [+0x000] variant1 [Type: enum$<core::option::Option<u32> >::Some]
// cdb-check: [+0x004] __0 : 0x5c0065 [Type: unsigned int]
// cdb-check: [+0x000] discriminant : None (0x0) [Type: core::option::Option]
// cdb-command: dx i
// cdb-check:i : None [Type: enum$<core::option::Option<u32> >]
// cdb-check: [+0x000] variant$ : None (0x0) [Type: core::option::Option]
// cdb-check: [<Raw View>] [Type: enum$<core::option::Option<u32> >]
// cdb-check: [variant] : None
// cdb-command: dx j
// cdb-check:j : High (0x10) [Type: msvc_pretty_enums::CStyleEnum]

8
src/test/debuginfo/pretty-std.rs
View File

@ -116,12 +116,14 @@
// cdb-command: dx some
// cdb-check:some : Some [Type: enum$<core::option::Option<i16> >]
// cdb-check: [...] variant$ : Some (0x1) [Type: core::option::Option]
// cdb-check: [...] __0 : 8 [Type: short]
// cdb-check: [<Raw View>] [Type: enum$<core::option::Option<i16> >]
// cdb-check: [variant] : Some
// cdb-check: [+0x002] __0 : 8 [Type: short]
// cdb-command: dx none
// cdb-check:none : None [Type: enum$<core::option::Option<i64> >]
// cdb-check: [...] variant$ : None (0x0) [Type: core::option::Option]
// cdb-check: [<Raw View>] [Type: enum$<core::option::Option<i64> >]
// cdb-check: [variant] : None
// cdb-command: dx some_string
// NOTE: cdb fails to interpret debug info of Option enums on i686.