Rollup merge of #93503 - michaelwoerister:fix-vtable-holder-debuginfo-regression, r=wesleywiser

debuginfo: Fix DW_AT_containing_type vtable debuginfo regression

This PR brings back the `DW_AT_containing_type` attribute for vtables after it has accidentally been removed in #89597.

It also implements a more accurate description of vtables. Instead of describing them as an array of void pointers, the compiler will now emit a struct type description with a field for each entry of the vtable.

r? ``@wesleywiser``

This PR should fix issue https://github.com/rust-lang/rust/issues/93164.
~~The PR is blocked on https://github.com/rust-lang/rust/pull/93154 because both of them modify the `codegen/debug-vtable.rs` test case.~~

2 files changed, 49 insertions, 26 deletions

diff --git a/src/test/codegen/debug-vtable.rs b/src/test/codegen/debug-vtable.rs
index 35fd275fd28..b9cb4f93d07 100644
--- a/src/test/codegen/debug-vtable.rs
+++ b/src/test/codegen/debug-vtable.rs
@@ -9,19 +9,41 @@
 // compile-flags: -Cdebuginfo=2 -Copt-level=0 -Csymbol-mangling-version=v0
 // ignore-tidy-linelength
 
+// NONMSVC: ![[USIZE:[0-9]+]] = !DIBasicType(name: "usize"
+// MSVC: ![[USIZE:[0-9]+]] = !DIDerivedType(tag: DW_TAG_typedef, name: "usize"
+// NONMSVC: ![[PTR:[0-9]+]] = !DIDerivedType(tag: DW_TAG_pointer_type, name: "*const ()"
+// MSVC: ![[PTR:[0-9]+]] = !DIDerivedType(tag: DW_TAG_pointer_type, name: "ptr_const$<tuple$<> >"
+
 // NONMSVC: !DIGlobalVariable(name: "<debug_vtable::Foo as debug_vtable::SomeTrait>::{vtable}"
 // MSVC: !DIGlobalVariable(name: "impl$<debug_vtable::Foo, debug_vtable::SomeTrait>::vtable$"
-// NONMSVC: !DIDerivedType(tag: DW_TAG_pointer_type, name: "*const ()",
-// MSVC: !DIDerivedType(tag: DW_TAG_pointer_type, name: "ptr_const$<tuple$<> >",
-// CHECK: !DISubrange(count: 5
+
+// NONMSVC: ![[VTABLE_TY0:[0-9]+]] = !DICompositeType(tag: DW_TAG_structure_type, name: "<debug_vtable::Foo as debug_vtable::SomeTrait>::{vtable_type}", {{.*}} size: {{320|160}}, align: {{64|32}}, flags: DIFlagArtificial, {{.*}} vtableHolder: ![[FOO_TYPE:[0-9]+]],
+// MSVC: ![[VTABLE_TY0:[0-9]+]] = !DICompositeType(tag: DW_TAG_structure_type, name: "impl$<debug_vtable::Foo, debug_vtable::SomeTrait>::vtable_type$", {{.*}} size: {{320|160}}, align: {{64|32}}, flags: DIFlagArtificial, {{.*}} vtableHolder: ![[FOO_TYPE:[0-9]+]],
+// CHECK: !DIDerivedType(tag: DW_TAG_member, name: "drop_in_place", scope: ![[VTABLE_TY0]], {{.*}} baseType: ![[PTR]], size: {{64|32}}, align: {{64|32}})
+// CHECK: !DIDerivedType(tag: DW_TAG_member, name: "size", scope: ![[VTABLE_TY0]], {{.*}} baseType: ![[USIZE]], size: {{64|32}}, align: {{64|32}}, offset: {{64|32}})
+// CHECK: !DIDerivedType(tag: DW_TAG_member, name: "align", scope: ![[VTABLE_TY0]], {{.*}} baseType: ![[USIZE]], size: {{64|32}}, align: {{64|32}}, offset: {{128|64}})
+// CHECK: !DIDerivedType(tag: DW_TAG_member, name: "__method3", scope: ![[VTABLE_TY0]], {{.*}} baseType: ![[PTR]], size: {{64|32}}, align: {{64|32}}, offset: {{192|96}})
+// CHECK: !DIDerivedType(tag: DW_TAG_member, name: "__method4", scope: ![[VTABLE_TY0]], {{.*}} baseType: ![[PTR]], size: {{64|32}}, align: {{64|32}}, offset: {{256|128}})
+// CHECK: ![[FOO_TYPE]] = !DICompositeType(tag: DW_TAG_structure_type, name: "Foo",
 
 // NONMSVC: !DIGlobalVariable(name: "<debug_vtable::Foo as debug_vtable::SomeTraitWithGenerics<u64, i8>>::{vtable}"
 // MSVC: !DIGlobalVariable(name: "impl$<debug_vtable::Foo, debug_vtable::SomeTraitWithGenerics<u64,i8> >::vtable$"
-// CHECK: !DISubrange(count: 4
+
+// NONMSVC: ![[VTABLE_TY1:[0-9]+]] = !DICompositeType(tag: DW_TAG_structure_type, name: "<debug_vtable::Foo as debug_vtable::SomeTraitWithGenerics<u64, i8>>::{vtable_type}", {{.*}}, size: {{256|128}}, align: {{64|32}}, flags: DIFlagArtificial, {{.*}}, vtableHolder: ![[FOO_TYPE]],
+// MSVC: ![[VTABLE_TY1:[0-9]+]] = !DICompositeType(tag: DW_TAG_structure_type, name: "impl$<debug_vtable::Foo, debug_vtable::SomeTraitWithGenerics<u64,i8> >::vtable_type$", {{.*}}, size: {{256|128}}, align: {{64|32}}, flags: DIFlagArtificial, {{.*}}, vtableHolder: ![[FOO_TYPE]],
+// CHECK: !DIDerivedType(tag: DW_TAG_member, name: "drop_in_place", scope: ![[VTABLE_TY1]], {{.*}} baseType: ![[PTR]], size: {{64|32}}, align: {{64|32}})
+// CHECK: !DIDerivedType(tag: DW_TAG_member, name: "size", scope: ![[VTABLE_TY1]], {{.*}} baseType: ![[USIZE]], size: {{64|32}}, align: {{64|32}}, offset: {{64|32}})
+// CHECK: !DIDerivedType(tag: DW_TAG_member, name: "align", scope: ![[VTABLE_TY1]], {{.*}} baseType: ![[USIZE]], size: {{64|32}}, align: {{64|32}}, offset: {{128|64}})
+// CHECK: !DIDerivedType(tag: DW_TAG_member, name: "__method3", scope: ![[VTABLE_TY1]], {{.*}} baseType: ![[PTR]], size: {{64|32}}, align: {{64|32}}, offset: {{192|96}})
 
 // NONMSVC: !DIGlobalVariable(name: "<debug_vtable::Foo as _>::{vtable}"
 // MSVC: !DIGlobalVariable(name: "impl$<debug_vtable::Foo, _>::vtable$"
-// CHECK: !DISubrange(count: 3
+
+// NONMSVC: ![[VTABLE_TY2:[0-9]+]] = !DICompositeType(tag: DW_TAG_structure_type, name: "<debug_vtable::Foo as _>::{vtable_type}", {{.*}}, size: {{192|96}}, align: {{64|32}}, flags: DIFlagArtificial, {{.*}}, vtableHolder: ![[FOO_TYPE]],
+// MSVC: ![[VTABLE_TY2:[0-9]+]] = !DICompositeType(tag: DW_TAG_structure_type, name: "impl$<debug_vtable::Foo, _>::vtable_type$", {{.*}}, size: {{192|96}}, align: {{64|32}}, flags: DIFlagArtificial, {{.*}}, vtableHolder: ![[FOO_TYPE]],
+// CHECK: !DIDerivedType(tag: DW_TAG_member, name: "drop_in_place", scope: ![[VTABLE_TY2]], {{.*}}, baseType: ![[PTR]], size: {{64|32}}, align: {{64|32}})
+// CHECK: !DIDerivedType(tag: DW_TAG_member, name: "size", scope: ![[VTABLE_TY2]], {{.*}}, baseType: ![[USIZE]], size: {{64|32}}, align: {{64|32}}, offset: {{64|32}})
+// CHECK: !DIDerivedType(tag: DW_TAG_member, name: "align", scope: ![[VTABLE_TY2]], {{.*}}, baseType: ![[USIZE]], size: {{64|32}}, align: {{64|32}}, offset: {{128|64}})
 
 // NONMSVC: !DIGlobalVariable(name: "<debug_vtable::bar::{closure_env#0} as core::ops::function::FnOnce<(core::option::Option<&dyn core::ops::function::Fn<(), Output=()>>)>>::{vtable}"
 // MSVC: !DIGlobalVariable(name: "impl$<debug_vtable::bar::closure_env$0, core::ops::function::FnOnce<tuple$<enum$<core::option::Option<ref$<dyn$<core::ops::function::Fn<tuple$<>,assoc$<Output,tuple$<> > > > > >, {{.*}}, {{.*}}, Some> > > >::vtable$"
@@ -34,6 +56,9 @@
 
 #![crate_type = "lib"]
 
+// Force emission for debuginfo for usize and *const() early..
+pub static mut XYZ: Option<(usize, *const ())> = None;
+
 pub struct Foo;
 
 pub trait SomeTrait {
diff --git a/src/test/codegen/debuginfo-generic-closure-env-names.rs b/src/test/codegen/debuginfo-generic-closure-env-names.rs
index 6e5ac951261..ad59f740b56 100644
--- a/src/test/codegen/debuginfo-generic-closure-env-names.rs
+++ b/src/test/codegen/debuginfo-generic-closure-env-names.rs
@@ -17,35 +17,34 @@
 
 // compile-flags: -Cdebuginfo=2 --edition 2021 -Copt-level=0 -Csymbol-mangling-version=v0
 
-
-// CHECK: [[non_generic_closure_NAMESPACE:!.*]] = !DINamespace(name: "non_generic_closure"
-// CHECK: [[function_containing_closure_NAMESPACE:!.*]] = !DINamespace(name: "function_containing_closure"
-// CHECK: [[generic_async_function_NAMESPACE:!.*]] = !DINamespace(name: "generic_async_function"
-// CHECK: [[generic_async_block_NAMESPACE:!.*]] = !DINamespace(name: "generic_async_block"
-
 // non_generic_closure()
-// NONMSVC: !DICompositeType(tag: DW_TAG_structure_type, name: "{closure_env#0}", scope: [[non_generic_closure_NAMESPACE]]
-// MSVC: !DICompositeType(tag: DW_TAG_structure_type, name: "closure_env$0", scope: [[non_generic_closure_NAMESPACE]]
+// NONMSVC: !DICompositeType(tag: DW_TAG_structure_type, name: "{closure_env#0}", scope: ![[non_generic_closure_NAMESPACE:[0-9]+]],
+// MSVC: !DICompositeType(tag: DW_TAG_structure_type, name: "closure_env$0", scope: ![[non_generic_closure_NAMESPACE:[0-9]+]],
+// CHECK: ![[non_generic_closure_NAMESPACE]] = !DINamespace(name: "non_generic_closure"
+
+// CHECK: ![[function_containing_closure_NAMESPACE:[0-9]+]] = !DINamespace(name: "function_containing_closure"
+// CHECK: ![[generic_async_function_NAMESPACE:[0-9]+]] = !DINamespace(name: "generic_async_function"
+// CHECK: ![[generic_async_block_NAMESPACE:[0-9]+]] = !DINamespace(name: "generic_async_block"
 
 // function_containing_closure<u32>()
-// NONMSVC: !DICompositeType(tag: DW_TAG_structure_type, name: "{closure_env#0}<u32>", scope: [[function_containing_closure_NAMESPACE]]
-// MSVC: !DICompositeType(tag: DW_TAG_structure_type, name: "closure_env$0<u32>", scope: [[function_containing_closure_NAMESPACE]]
+// NONMSVC: !DICompositeType(tag: DW_TAG_structure_type, name: "{closure_env#0}<u32>", scope: ![[function_containing_closure_NAMESPACE]]
+// MSVC: !DICompositeType(tag: DW_TAG_structure_type, name: "closure_env$0<u32>", scope: ![[function_containing_closure_NAMESPACE]]
 
 // generic_async_function<Foo>()
-// NONMSVC: !DICompositeType(tag: DW_TAG_structure_type, name: "{async_fn_env#0}<debuginfo_generic_closure_env_names::Foo>", scope: [[generic_async_function_NAMESPACE]]
+// NONMSVC: !DICompositeType(tag: DW_TAG_structure_type, name: "{async_fn_env#0}<debuginfo_generic_closure_env_names::Foo>", scope: ![[generic_async_function_NAMESPACE]]
 
 // generic_async_function<u32>()
-// NONMSVC: !DICompositeType(tag: DW_TAG_structure_type, name: "{async_fn_env#0}<u32>", scope: [[generic_async_function_NAMESPACE]]
+// NONMSVC: !DICompositeType(tag: DW_TAG_structure_type, name: "{async_fn_env#0}<u32>", scope: ![[generic_async_function_NAMESPACE]]
 
 // generic_async_block<Foo>()
-// NONMSVC: !DICompositeType(tag: DW_TAG_structure_type, name: "{async_block_env#0}<debuginfo_generic_closure_env_names::Foo>", scope: [[generic_async_block_NAMESPACE]]
+// NONMSVC: !DICompositeType(tag: DW_TAG_structure_type, name: "{async_block_env#0}<debuginfo_generic_closure_env_names::Foo>", scope: ![[generic_async_block_NAMESPACE]]
 
 // generic_async_block<u32>()
-// NONMSVC: !DICompositeType(tag: DW_TAG_structure_type, name: "{async_block_env#0}<u32>", scope: [[generic_async_block_NAMESPACE]]
+// NONMSVC: !DICompositeType(tag: DW_TAG_structure_type, name: "{async_block_env#0}<u32>", scope: ![[generic_async_block_NAMESPACE]]
 
 // function_containing_closure<Foo>()
-// NONMSVC: !DICompositeType(tag: DW_TAG_structure_type, name: "{closure_env#0}<debuginfo_generic_closure_env_names::Foo>", scope: [[function_containing_closure_NAMESPACE]]
-// MSVC: !DICompositeType(tag: DW_TAG_structure_type, name: "closure_env$0<debuginfo_generic_closure_env_names::Foo>", scope: [[function_containing_closure_NAMESPACE]]
+// NONMSVC: !DICompositeType(tag: DW_TAG_structure_type, name: "{closure_env#0}<debuginfo_generic_closure_env_names::Foo>", scope: ![[function_containing_closure_NAMESPACE]]
+// MSVC: !DICompositeType(tag: DW_TAG_structure_type, name: "closure_env$0<debuginfo_generic_closure_env_names::Foo>", scope: ![[function_containing_closure_NAMESPACE]]
 
 
 #![crate_type = "lib"]
@@ -54,15 +53,14 @@ use std::future::Future;
 pub struct Foo;
 
 pub fn non_generic_closure(x: Foo) -> Box<dyn FnOnce() -> Foo> {
-    // This static only exists to trigger generating the namespace debuginfo for
-    // `function_containing_closure` at a predictable, early point, which makes
-    // writing the FileCheck tests above simpler.
-    static _X: u8 = 0;
     return Box::new(move || x);
 }
 
 fn function_containing_closure<T: 'static>(x: T) -> impl FnOnce() -> T {
-    static _X: u8 = 0; // Same as above
+    // This static only exists to trigger generating the namespace debuginfo for
+    // `function_containing_closure` at a predictable, early point, which makes
+    // writing the FileCheck tests above simpler.
+    static _X: u8 = 0;
 
     return move || x;
 }