Skip to content

Commit

Permalink
Respond to review feedback
Browse files Browse the repository at this point in the history
  • Loading branch information
@wesleywiser
wesleywiser committed Jun 2, 2021
1 parent ef053fd commit 3127419
Show file tree
Hide file tree
Showing 4 changed files with 61 additions and 98 deletions.
90 changes: 28 additions & 62 deletions compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1485,8 +1485,8 @@ impl EnumMemberDescriptionFactory<'ll, 'tcx> {
_ => bug!(),
};

// This will always find the metadata in the type map.
let fallback = use_enum_fallback(cx);
// This will always find the metadata in the type map.
let self_metadata = type_metadata(cx, self.enum_type, self.span);

match self.layout.variants {
Expand Down Expand Up @@ -1541,11 +1541,11 @@ impl EnumMemberDescriptionFactory<'ll, 'tcx> {
// struct {variant 0 name} {
// tag$ variant$;
// <variant 0 fields>
// } Variant0;
// } variant0;
// <other variant structs>
// }
// ```
// The natvis in `intrinsic.nativs` then matches on `this.Variant0.variant$` to
// The natvis in `intrinsic.nativs` then matches on `this.variant0.variant$` to
// determine which variant is active and then displays it.
Some(DirectTag {
tag_field: Field::from(tag_field),
Expand Down Expand Up @@ -1582,7 +1582,7 @@ impl EnumMemberDescriptionFactory<'ll, 'tcx> {

MemberDescription {
name: if fallback {
format!("Variant{}", i.as_u32())
format!("variant{}", i.as_u32())
} else {
variant_info.variant_name()
},
Expand Down Expand Up @@ -1623,43 +1623,27 @@ impl EnumMemberDescriptionFactory<'ll, 'tcx> {
}
};

// For MSVC, we will generate a union of two structs, one for the dataful variant and one that just points to
// the discriminant field. We also create an enum that contains tag values for the non-dataful variants and
// make the discriminant field that type. We then use natvis to render the enum type correctly in Windbg/VS.
// For MSVC, we will generate a union of two fields, one for the dataful variant
// and one that just points to the discriminant. We also create an enum that
// contains tag values for the non-dataful variants and make the discriminant field
// that type. We then use natvis to render the enum type correctly in Windbg/VS.
// This will generate debuginfo roughly equivalent to the following C:
// ```c
// union enum$<{name}, {min niche}, {max niche}, {dataful variant name} {
// struct dataful_variant {
// union enum$<{name}, {min niche}, {max niche}, {dataful variant name}> {
// struct <dataful variant name> {
// <fields in dataful variant>
// },
// struct discriminant$ {
// enum tag$ {
// <non-dataful variants>
// } discriminant;
// }
// } dataful_variant;
// enum Discriminant$ {
// <non-dataful variants>
// } discriminant;
// }
// ```
// The natvis in `intrinsic.natvis` matches on the type name `enum$<*, *, *, *>`
// and evaluates `this.discriminant$.discriminant`. If the value is between
// the min niche and max niche, then the enum is in the dataful variant and
// `this.dataful_variant` is rendered. Otherwise, the enum is in one of the
// non-dataful variants. In that case, we just need to render the name of the
// `this.discriminant$.discriminant` enum.
// and evaluates `this.discriminant`. If the value is between the min niche and max
// niche, then the enum is in the dataful variant and `this.dataful_variant` is
// rendered. Otherwise, the enum is in one of the non-dataful variants. In that
// case, we just need to render the name of the `this.discriminant` enum.
if fallback {
let unique_type_id = debug_context(cx)
.type_map
.borrow_mut()
.get_unique_type_id_of_enum_variant(cx, self.enum_type, "discriminant$");

let variant_metadata = create_struct_stub(
cx,
self.layout.ty,
&"discriminant$",
unique_type_id,
Some(self_metadata),
DIFlags::FlagArtificial,
);

let dataful_variant_layout = self.layout.for_variant(cx, dataful_variant);

let mut discr_enum_ty = tag.value.to_ty(cx.tcx);
Expand Down Expand Up @@ -1694,8 +1678,8 @@ impl EnumMemberDescriptionFactory<'ll, 'tcx> {
llvm::LLVMRustDIBuilderCreateEnumerationType(
DIB(cx),
self_metadata,
"tag$".as_ptr().cast(),
"tag$".len(),
"Discriminant$".as_ptr().cast(),
"Discriminant$".len(),
unknown_file_metadata(cx),
UNKNOWN_LINE_NUMBER,
tag.value.size(cx).bits(),
Expand All @@ -1706,27 +1690,6 @@ impl EnumMemberDescriptionFactory<'ll, 'tcx> {
)
};

let (size, align) =
cx.size_and_align_of(dataful_variant_layout.field(cx, tag_field).ty);
let members = vec![MemberDescription {
name: "discriminant".to_string(),
type_metadata: discr_enum,
offset: dataful_variant_layout.fields.offset(tag_field),
size,
align,
flags: DIFlags::FlagArtificial,
discriminant: None,
source_info: None,
}];

set_members_of_composite_type(
cx,
self.enum_type,
variant_metadata,
members,
None,
);

let variant_info = variant_info_for(dataful_variant);
let (variant_type_metadata, member_desc_factory) = describe_enum_variant(
cx,
Expand All @@ -1747,6 +1710,9 @@ impl EnumMemberDescriptionFactory<'ll, 'tcx> {
Some(&self.common_members),
);

let (size, align) =
cx.size_and_align_of(dataful_variant_layout.field(cx, tag_field).ty);

vec![
MemberDescription {
// Name the dataful variant so that we can identify it for natvis
Expand All @@ -1760,11 +1726,11 @@ impl EnumMemberDescriptionFactory<'ll, 'tcx> {
source_info: variant_info.source_info(cx),
},
MemberDescription {
name: "discriminant$".into(),
type_metadata: variant_metadata,
offset: Size::ZERO,
size: self.layout.size,
align: self.layout.align.abi,
name: "discriminant".into(),
type_metadata: discr_enum,
offset: dataful_variant_layout.fields.offset(tag_field),
size,
align,
flags: DIFlags::FlagZero,
discriminant: None,
source_info: None,
Expand Down
4 changes: 4 additions & 0 deletions compiler/rustc_codegen_ssa/src/debuginfo/type_names.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -238,6 +238,10 @@ pub fn push_debuginfo_type_name<'tcx>(
}
}

/// MSVC names enums differently than other platforms so that the debugging visualization
// format (natvis) is able to understand enums and render the active variant correctly in the
// debugger. For more information, look in `src/etc/natvis/intrinsic.natvis` and
// `EnumMemberDescriptionFactor::create_member_descriptions`.
fn msvc_enum_fallback(
tcx: TyCtxt<'tcx>,
ty: Ty<'tcx>,
Expand Down
41 changes: 21 additions & 20 deletions src/etc/natvis/intrinsic.natvis
View file
Original file line number Diff line number Diff line change
Expand Up @@ -150,7 +150,7 @@
</Expand>
</Type>
<Type Name="enum$&lt;*&gt;">
<Intrinsic Name="tag" Expression="Variant0.variant$" />
<Intrinsic Name="tag" Expression="variant0.variant$" />
<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>
Expand All @@ -169,31 +169,32 @@
<DisplayString Condition="tag() == 15" Optional="true">{tag(),en}</DisplayString>

<Expand>
<ExpandedItem Condition="tag() == 0">Variant0</ExpandedItem>
<ExpandedItem Condition="tag() == 1" Optional="true">Variant1</ExpandedItem>
<ExpandedItem Condition="tag() == 2" Optional="true">Variant2</ExpandedItem>
<ExpandedItem Condition="tag() == 3" Optional="true">Variant3</ExpandedItem>
<ExpandedItem Condition="tag() == 4" Optional="true">Variant4</ExpandedItem>
<ExpandedItem Condition="tag() == 5" Optional="true">Variant5</ExpandedItem>
<ExpandedItem Condition="tag() == 6" Optional="true">Variant6</ExpandedItem>
<ExpandedItem Condition="tag() == 7" Optional="true">Variant7</ExpandedItem>
<ExpandedItem Condition="tag() == 8" Optional="true">Variant8</ExpandedItem>
<ExpandedItem Condition="tag() == 9" Optional="true">Variant9</ExpandedItem>
<ExpandedItem Condition="tag() == 10" Optional="true">Variant10</ExpandedItem>
<ExpandedItem Condition="tag() == 11" Optional="true">Variant11</ExpandedItem>
<ExpandedItem Condition="tag() == 12" Optional="true">Variant12</ExpandedItem>
<ExpandedItem Condition="tag() == 13" Optional="true">Variant13</ExpandedItem>
<ExpandedItem Condition="tag() == 14" Optional="true">Variant14</ExpandedItem>
<ExpandedItem Condition="tag() == 15" Optional="true">Variant15</ExpandedItem>
<ExpandedItem Condition="tag() == 0">variant0</ExpandedItem>
<ExpandedItem Condition="tag() == 1" Optional="true">variant1</ExpandedItem>
<ExpandedItem Condition="tag() == 2" Optional="true">variant2</ExpandedItem>
<ExpandedItem Condition="tag() == 3" Optional="true">variant3</ExpandedItem>
<ExpandedItem Condition="tag() == 4" Optional="true">variant4</ExpandedItem>
<ExpandedItem Condition="tag() == 5" Optional="true">variant5</ExpandedItem>
<ExpandedItem Condition="tag() == 6" Optional="true">variant6</ExpandedItem>
<ExpandedItem Condition="tag() == 7" Optional="true">variant7</ExpandedItem>
<ExpandedItem Condition="tag() == 8" Optional="true">variant8</ExpandedItem>
<ExpandedItem Condition="tag() == 9" Optional="true">variant9</ExpandedItem>
<ExpandedItem Condition="tag() == 10" Optional="true">variant10</ExpandedItem>
<ExpandedItem Condition="tag() == 11" Optional="true">variant11</ExpandedItem>
<ExpandedItem Condition="tag() == 12" Optional="true">variant12</ExpandedItem>
<ExpandedItem Condition="tag() == 13" Optional="true">variant13</ExpandedItem>
<ExpandedItem Condition="tag() == 14" Optional="true">variant14</ExpandedItem>
<ExpandedItem Condition="tag() == 15" Optional="true">variant15</ExpandedItem>
</Expand>
</Type>

<!-- $T1 is the name of the enum, $T2 is the low value of the dataful variant tag, $T3 is the high value of the dataful variant tag, $T4 is the name of the dataful variant -->
<!-- $T1 is the name of the enum, $T2 is the low value of the dataful variant tag,
$T3 is the high value of the dataful variant tag, $T4 is the name of the dataful variant -->
<Type Name="enum$&lt;*, *, *, *&gt;">
<Intrinsic Name="tag" Expression="discriminant$.discriminant" />
<Intrinsic Name="tag" Expression="discriminant" />
<Intrinsic Name="is_dataful" Expression="tag() &gt;= $T2 &amp;&amp; tag() &lt;= $T3" />
<DisplayString Condition="is_dataful()">{"$T4",sb}({dataful_variant})</DisplayString>
<DisplayString Condition="!is_dataful()">{discriminant$.discriminant,en}</DisplayString>
<DisplayString Condition="!is_dataful()">{discriminant,en}</DisplayString>
<Expand>
<ExpandedItem Condition="is_dataful()">dataful_variant</ExpandedItem>
<Synthetic Condition="is_dataful()" Name="[variant]">
Expand Down
24 changes: 8 additions & 16 deletions src/test/debuginfo/msvc-pretty-enums.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -11,50 +11,43 @@
// cdb-check:a,! [Type: enum$<core::option::Option<enum$<msvc_pretty_enums::CStyleEnum>>, 2, 16, Some>]
// cdb-check: [+0x000] dataful_variant [Type: enum$<core::option::Option<enum$<msvc_pretty_enums::CStyleEnum>>, 2, 16, Some>::Some]
// cdb-check: [+0x000] __0 : Low (0x2) [Type: msvc_pretty_enums::CStyleEnum]
// cdb-check: [+0x000] discriminant$ [Type: enum$<core::option::Option<enum$<msvc_pretty_enums::CStyleEnum>>, 2, 16, Some>::discriminant$]
// cdb-check: [+0x000] discriminant : 0x2 [Type: enum$<core::option::Option<enum$<msvc_pretty_enums::CStyleEnum>>, 2, 16, Some>::tag$]
// cdb-check: [+0x000] discriminant : 0x2 [Type: enum$<core::option::Option<enum$<msvc_pretty_enums::CStyleEnum>>, 2, 16, Some>::Discriminant$]

// cdb-command: dx -r2 b,!
// cdb-check:b,! [Type: enum$<core::option::Option<enum$<msvc_pretty_enums::CStyleEnum>>, 2, 16, Some>]
// cdb-check: [+0x000] dataful_variant [Type: enum$<core::option::Option<enum$<msvc_pretty_enums::CStyleEnum>>, 2, 16, Some>::Some]
// cdb-check: [+0x000] __0 : 0x11 [Type: msvc_pretty_enums::CStyleEnum]
// cdb-check: [+0x000] discriminant$ [Type: enum$<core::option::Option<enum$<msvc_pretty_enums::CStyleEnum>>, 2, 16, Some>::discriminant$]
// cdb-check: [+0x000] discriminant : None (0x11) [Type: enum$<core::option::Option<enum$<msvc_pretty_enums::CStyleEnum>>, 2, 16, Some>::tag$]
// cdb-check: [+0x000] discriminant : None (0x11) [Type: enum$<core::option::Option<enum$<msvc_pretty_enums::CStyleEnum>>, 2, 16, Some>::Discriminant$]

// cdb-command: dx -r2 c,!
// cdb-check:c,! [Type: enum$<msvc_pretty_enums::NicheLayoutEnum, 2, 16, Data>]
// cdb-check: [+0x000] dataful_variant [Type: enum$<msvc_pretty_enums::NicheLayoutEnum, 2, 16, Data>::Data]
// cdb-check: [+0x000] my_data : 0x11 [Type: msvc_pretty_enums::CStyleEnum]
// cdb-check: [+0x000] discriminant$ [Type: enum$<msvc_pretty_enums::NicheLayoutEnum, 2, 16, Data>::discriminant$]
// cdb-check: [+0x000] discriminant : Tag1 (0x11) [Type: enum$<msvc_pretty_enums::NicheLayoutEnum, 2, 16, Data>::tag$]
// cdb-check: [+0x000] discriminant : Tag1 (0x11) [Type: enum$<msvc_pretty_enums::NicheLayoutEnum, 2, 16, Data>::Discriminant$]

// cdb-command: dx -r2 d,!
// cdb-check:d,! [Type: enum$<msvc_pretty_enums::NicheLayoutEnum, 2, 16, Data>]
// cdb-check: [+0x000] dataful_variant [Type: enum$<msvc_pretty_enums::NicheLayoutEnum, 2, 16, Data>::Data]
// cdb-check: [+0x000] my_data : High (0x10) [Type: msvc_pretty_enums::CStyleEnum]
// cdb-check: [+0x000] discriminant$ [Type: enum$<msvc_pretty_enums::NicheLayoutEnum, 2, 16, Data>::discriminant$]
// cdb-check: [+0x000] discriminant : 0x10 [Type: enum$<msvc_pretty_enums::NicheLayoutEnum, 2, 16, Data>::tag$]
// cdb-check: [+0x000] discriminant : 0x10 [Type: enum$<msvc_pretty_enums::NicheLayoutEnum, 2, 16, Data>::Discriminant$]

// cdb-command: dx -r2 e,!
// cdb-check:e,! [Type: enum$<msvc_pretty_enums::NicheLayoutEnum, 2, 16, Data>]
// cdb-check: [+0x000] dataful_variant [Type: enum$<msvc_pretty_enums::NicheLayoutEnum, 2, 16, Data>::Data]
// cdb-check: [+0x000] my_data : 0x13 [Type: msvc_pretty_enums::CStyleEnum]
// cdb-check: [+0x000] discriminant$ [Type: enum$<msvc_pretty_enums::NicheLayoutEnum, 2, 16, Data>::discriminant$]
// cdb-check: [+0x000] discriminant : Tag2 (0x13) [Type: enum$<msvc_pretty_enums::NicheLayoutEnum, 2, 16, Data>::tag$]
// cdb-check: [+0x000] discriminant : Tag2 (0x13) [Type: enum$<msvc_pretty_enums::NicheLayoutEnum, 2, 16, Data>::Discriminant$]

// cdb-command: dx -r2 f,!
// cdb-check:f,! [Type: enum$<core::option::Option<u32*>, 1, [...], Some>]
// cdb-check: [+0x000] dataful_variant [Type: enum$<core::option::Option<u32*>, 1, [...], Some>::Some]
// cdb-check: [+0x000] __0 : 0x[...] : 0x1 [Type: unsigned int *]
// cdb-check: [+0x000] discriminant$ [Type: enum$<core::option::Option<u32*>, 1, [...], Some>::discriminant$]
// cdb-check: [+0x000] discriminant : 0x[...] [Type: enum$<core::option::Option<u32*>, 1, [...], Some>::tag$]
// cdb-check: [+0x000] discriminant : 0x[...] [Type: enum$<core::option::Option<u32*>, 1, [...], Some>::Discriminant$]

// cdb-command: dx -r2 g,!
// cdb-check:g,! [Type: enum$<core::option::Option<u32*>, 1, [...], Some>]
// cdb-check: [+0x000] dataful_variant [Type: enum$<core::option::Option<u32*>, 1, [...], Some>::Some]
// cdb-check: [+0x000] __0 : 0x0 [Type: unsigned int *]
// cdb-check: [+0x000] discriminant$ [Type: enum$<core::option::Option<u32*>, 1, [...], Some>::discriminant$]
// cdb-check: [+0x000] discriminant : None (0x0) [Type: enum$<core::option::Option<u32*>, 1, [...], Some>::tag$]
// cdb-check: [+0x000] discriminant : None (0x0) [Type: enum$<core::option::Option<u32*>, 1, [...], Some>::Discriminant$]

// cdb-command: dx h
// cdb-check:h : Some [Type: enum$<core::option::Option<u32>>]
Expand All @@ -72,8 +65,7 @@
// cdb-check:k,! [Type: enum$<core::option::Option<alloc::string::String>, 1, [...], Some>]
// cdb-check: [+0x000] dataful_variant [Type: enum$<core::option::Option<alloc::string::String>, 1, [...], Some>::Some]
// cdb-check: [+0x000] __0 [Type: alloc::string::String]
// cdb-check: [+0x000] discriminant$ [Type: enum$<core::option::Option<alloc::string::String>, 1, [...], Some>::discriminant$]
// cdb-check: [+0x000] discriminant : 0x[...] [Type: enum$<core::option::Option<alloc::string::String>, 1, [...], Some>::tag$]
// cdb-check: [+0x000] discriminant : 0x[...] [Type: enum$<core::option::Option<alloc::string::String>, 1, [...], Some>::Discriminant$]

pub enum CStyleEnum {
Low = 2,
Expand Down

0 comments on commit 3127419

Please sign in to comment.