Auto merge of #128037 - beetrees:repr128-c-style-use-natvis, r=michaelwoerister

Use the `enum2$` Natvis visualiser for repr128 C-style enums

Use the preexisting `enum2$` Natvis visualiser to allow PDB debuggers to display fieldless `#[repr(u128)]]`/`#[repr(i128)]]` enums correctly.

Tracking issue: #56071

try-job: x86_64-msvc

3 files changed, 16 insertions, 61 deletions

diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/cpp_like.rs b/compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/cpp_like.rs
index 13006638bb3..181022087f3 100644
--- a/compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/cpp_like.rs
+++ b/compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/cpp_like.rs
@@ -2,7 +2,7 @@ use std::borrow::Cow;
 
 use libc::c_uint;
 use rustc_codegen_ssa::debuginfo::type_names::compute_debuginfo_type_name;
-use rustc_codegen_ssa::debuginfo::wants_c_like_enum_debuginfo;
+use rustc_codegen_ssa::debuginfo::{tag_base_type, wants_c_like_enum_debuginfo};
 use rustc_codegen_ssa::traits::ConstMethods;
 use rustc_index::IndexVec;
 use rustc_middle::bug;
@@ -12,7 +12,7 @@ use rustc_target::abi::{Align, Endian, Size, TagEncoding, VariantIdx, Variants};
 use smallvec::smallvec;
 
 use crate::common::CodegenCx;
-use crate::debuginfo::metadata::enums::{tag_base_type, DiscrResult};
+use crate::debuginfo::metadata::enums::DiscrResult;
 use crate::debuginfo::metadata::type_map::{self, Stub, UniqueTypeId};
 use crate::debuginfo::metadata::{
     build_field_di_node, file_metadata, size_and_align_of, type_di_node, unknown_file_metadata,
@@ -190,7 +190,7 @@ pub(super) fn build_enum_type_di_node<'ll, 'tcx>(
     let enum_type_and_layout = cx.layout_of(enum_type);
     let enum_type_name = compute_debuginfo_type_name(cx.tcx, enum_type, false);
 
-    assert!(!wants_c_like_enum_debuginfo(enum_type_and_layout));
+    assert!(!wants_c_like_enum_debuginfo(cx.tcx, enum_type_and_layout));
 
     type_map::build_type_with_children(
         cx,
@@ -265,7 +265,7 @@ pub(super) fn build_coroutine_di_node<'ll, 'tcx>(
     let coroutine_type_and_layout = cx.layout_of(coroutine_type);
     let coroutine_type_name = compute_debuginfo_type_name(cx.tcx, coroutine_type, false);
 
-    assert!(!wants_c_like_enum_debuginfo(coroutine_type_and_layout));
+    assert!(!wants_c_like_enum_debuginfo(cx.tcx, coroutine_type_and_layout));
 
     type_map::build_type_with_children(
         cx,
@@ -381,7 +381,7 @@ fn build_union_fields_for_enum<'ll, 'tcx>(
     tag_field: usize,
     untagged_variant_index: Option<VariantIdx>,
 ) -> SmallVec<&'ll DIType> {
-    let tag_base_type = super::tag_base_type(cx, enum_type_and_layout);
+    let tag_base_type = tag_base_type(cx.tcx, enum_type_and_layout);
 
     let variant_names_type_di_node = build_variant_names_type_di_node(
         cx,
@@ -676,7 +676,7 @@ fn build_union_fields_for_direct_tag_coroutine<'ll, 'tcx>(
     let variant_range = coroutine_args.variant_range(coroutine_def_id, cx.tcx);
     let variant_count = (variant_range.start.as_u32()..variant_range.end.as_u32()).len();
 
-    let tag_base_type = tag_base_type(cx, coroutine_type_and_layout);
+    let tag_base_type = tag_base_type(cx.tcx, coroutine_type_and_layout);
 
     let variant_names_type_di_node = build_variant_names_type_di_node(
         cx,
@@ -803,7 +803,7 @@ fn build_union_fields_for_direct_tag_enum_or_coroutine<'ll, 'tcx>(
 
     assert_eq!(
         cx.size_and_align_of(enum_type_and_layout.field(cx, tag_field).ty),
-        cx.size_and_align_of(super::tag_base_type(cx, enum_type_and_layout))
+        cx.size_and_align_of(self::tag_base_type(cx.tcx, enum_type_and_layout))
     );
 
     // ... and a field for the tag. If the tag is 128 bits wide, this will actually
diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/mod.rs b/compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/mod.rs
index fc3adaf0681..77cbcd86cdd 100644
--- a/compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/mod.rs
+++ b/compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/mod.rs
@@ -1,17 +1,15 @@
 use std::borrow::Cow;
 
 use rustc_codegen_ssa::debuginfo::type_names::{compute_debuginfo_type_name, cpp_like_debuginfo};
-use rustc_codegen_ssa::debuginfo::wants_c_like_enum_debuginfo;
+use rustc_codegen_ssa::debuginfo::{tag_base_type, wants_c_like_enum_debuginfo};
 use rustc_hir::def::CtorKind;
 use rustc_index::IndexSlice;
 use rustc_middle::bug;
 use rustc_middle::mir::CoroutineLayout;
-use rustc_middle::ty::layout::{IntegerExt, LayoutOf, PrimitiveExt, TyAndLayout};
+use rustc_middle::ty::layout::{LayoutOf, TyAndLayout};
 use rustc_middle::ty::{self, AdtDef, CoroutineArgs, CoroutineArgsExt, Ty, VariantDef};
 use rustc_span::Symbol;
-use rustc_target::abi::{
-    FieldIdx, HasDataLayout, Integer, Primitive, TagEncoding, VariantIdx, Variants,
-};
+use rustc_target::abi::{FieldIdx, TagEncoding, VariantIdx, Variants};
 
 use super::type_map::{DINodeCreationResult, UniqueTypeId};
 use super::{size_and_align_of, SmallVec};
@@ -39,7 +37,7 @@ pub(super) fn build_enum_type_di_node<'ll, 'tcx>(
 
     let enum_type_and_layout = cx.layout_of(enum_type);
 
-    if wants_c_like_enum_debuginfo(enum_type_and_layout) {
+    if wants_c_like_enum_debuginfo(cx.tcx, enum_type_and_layout) {
         return build_c_style_enum_di_node(cx, enum_adt_def, enum_type_and_layout);
     }
 
@@ -74,7 +72,7 @@ fn build_c_style_enum_di_node<'ll, 'tcx>(
         di_node: build_enumeration_type_di_node(
             cx,
             &compute_debuginfo_type_name(cx.tcx, enum_type_and_layout.ty, false),
-            tag_base_type(cx, enum_type_and_layout),
+            tag_base_type(cx.tcx, enum_type_and_layout),
             enum_adt_def.discriminants(cx.tcx).map(|(variant_index, discr)| {
                 let name = Cow::from(enum_adt_def.variant(variant_index).name.as_str());
                 (name, discr.val)
@@ -85,48 +83,6 @@ fn build_c_style_enum_di_node<'ll, 'tcx>(
     }
 }
 
-/// Extract the type with which we want to describe the tag of the given enum or coroutine.
-fn tag_base_type<'ll, 'tcx>(
-    cx: &CodegenCx<'ll, 'tcx>,
-    enum_type_and_layout: TyAndLayout<'tcx>,
-) -> Ty<'tcx> {
-    assert!(match enum_type_and_layout.ty.kind() {
-        ty::Coroutine(..) => true,
-        ty::Adt(adt_def, _) => adt_def.is_enum(),
-        _ => false,
-    });
-
-    match enum_type_and_layout.layout.variants() {
-        // A single-variant enum has no discriminant.
-        Variants::Single { .. } => {
-            bug!("tag_base_type() called for enum without tag: {:?}", enum_type_and_layout)
-        }
-
-        Variants::Multiple { tag_encoding: TagEncoding::Niche { .. }, tag, .. } => {
-            // Niche tags are always normalized to unsized integers of the correct size.
-            match tag.primitive() {
-                Primitive::Int(t, _) => t,
-                Primitive::Float(f) => Integer::from_size(f.size()).unwrap(),
-                // FIXME(erikdesjardins): handle non-default addrspace ptr sizes
-                Primitive::Pointer(_) => {
-                    // If the niche is the NULL value of a reference, then `discr_enum_ty` will be
-                    // a RawPtr. CodeView doesn't know what to do with enums whose base type is a
-                    // pointer so we fix this up to just be `usize`.
-                    // DWARF might be able to deal with this but with an integer type we are on
-                    // the safe side there too.
-                    cx.data_layout().ptr_sized_integer()
-                }
-            }
-            .to_ty(cx.tcx, false)
-        }
-
-        Variants::Multiple { tag_encoding: TagEncoding::Direct, tag, .. } => {
-            // Direct tags preserve the sign.
-            tag.primitive().to_ty(cx.tcx)
-        }
-    }
-}
-
 /// Build a DW_TAG_enumeration_type debuginfo node, with the given base type and variants.
 /// This is a helper function and does not register anything in the type map by itself.
 ///
diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/native.rs b/compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/native.rs
index d7e3b47e0bd..238fbad4dfd 100644
--- a/compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/native.rs
+++ b/compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/native.rs
@@ -2,7 +2,7 @@ use std::borrow::Cow;
 
 use libc::c_uint;
 use rustc_codegen_ssa::debuginfo::type_names::compute_debuginfo_type_name;
-use rustc_codegen_ssa::debuginfo::wants_c_like_enum_debuginfo;
+use rustc_codegen_ssa::debuginfo::{tag_base_type, wants_c_like_enum_debuginfo};
 use rustc_codegen_ssa::traits::ConstMethods;
 use rustc_middle::bug;
 use rustc_middle::ty::layout::{LayoutOf, TyAndLayout};
@@ -11,7 +11,6 @@ use rustc_target::abi::{Size, TagEncoding, VariantIdx, Variants};
 use smallvec::smallvec;
 
 use crate::common::CodegenCx;
-use crate::debuginfo::metadata::enums::tag_base_type;
 use crate::debuginfo::metadata::type_map::{self, Stub, StubInfo, UniqueTypeId};
 use crate::debuginfo::metadata::{
     file_metadata, size_and_align_of, type_di_node, unknown_file_metadata, visibility_di_flags,
@@ -54,7 +53,7 @@ pub(super) fn build_enum_type_di_node<'ll, 'tcx>(
 
     let visibility_flags = visibility_di_flags(cx, enum_adt_def.did(), enum_adt_def.did());
 
-    assert!(!wants_c_like_enum_debuginfo(enum_type_and_layout));
+    assert!(!wants_c_like_enum_debuginfo(cx.tcx, enum_type_and_layout));
 
     type_map::build_type_with_children(
         cx,
@@ -131,7 +130,7 @@ pub(super) fn build_coroutine_di_node<'ll, 'tcx>(
     let containing_scope = get_namespace_for_item(cx, coroutine_def_id);
     let coroutine_type_and_layout = cx.layout_of(coroutine_type);
 
-    assert!(!wants_c_like_enum_debuginfo(coroutine_type_and_layout));
+    assert!(!wants_c_like_enum_debuginfo(cx.tcx, coroutine_type_and_layout));
 
     let coroutine_type_name = compute_debuginfo_type_name(cx.tcx, coroutine_type, false);
 
@@ -321,7 +320,7 @@ fn build_discr_member_di_node<'ll, 'tcx>(
         &Variants::Single { .. } => None,
 
         &Variants::Multiple { tag_field, .. } => {
-            let tag_base_type = tag_base_type(cx, enum_or_coroutine_type_and_layout);
+            let tag_base_type = tag_base_type(cx.tcx, enum_or_coroutine_type_and_layout);
             let (size, align) = cx.size_and_align_of(tag_base_type);
 
             unsafe {