[clang] [clang][DebugInfo] Set EnumKind based on enum_extensibility attribute (PR #126045)

[Michael Buch via cfe-commits]

https://github.com/Michael137 updated https://github.com/llvm/llvm-project/pull/126045

>From 10d37ec7e406d3b6ff5034003087a4b6cbb76fe0 Mon Sep 17 00:00:00 2001
From: Michael Buch <michaelbuch12 at gmail.com>
Date: Wed, 5 Feb 2025 12:02:50 +0000
Subject: [PATCH] [clang][DebugInfo] Set EnumKind based on enum_extensibility
 attribute

This is the 2nd part to https://github.com/llvm/llvm-project/pull/124752. Here we make sure to set the `DICompositeType` `EnumKind` if the enum was declared with `__attribute__((enum_extensibility(...)))`. In DWARF this will be rendered as `DW_AT_APPLE_enum_kind` and will be used by LLDB when creating `clang::EnumDecl`s from debug-info.
---
 clang/lib/CodeGen/CGDebugInfo.cpp             |  6 ++-
 .../CodeGen/debug-info-enum-extensibility.c   | 49 +++++++++++++++++++
 2 files changed, 54 insertions(+), 1 deletion(-)
 create mode 100644 clang/test/CodeGen/debug-info-enum-extensibility.c

diff --git a/clang/lib/CodeGen/CGDebugInfo.cpp b/clang/lib/CodeGen/CGDebugInfo.cpp
index db595796c067e98..d5b584ec0f2e95b 100644
--- a/clang/lib/CodeGen/CGDebugInfo.cpp
+++ b/clang/lib/CodeGen/CGDebugInfo.cpp
@@ -3567,6 +3567,10 @@ llvm::DIType *CGDebugInfo::CreateTypeDefinition(const EnumType *Ty) {
         DBuilder.createEnumerator(Enum->getName(), Enum->getInitVal()));
   }
 
+  std::optional<EnumExtensibilityAttr::Kind> EnumKind;
+  if (auto *Attr = ED->getAttr<EnumExtensibilityAttr>())
+    EnumKind = Attr->getExtensibility();
+
   // Return a CompositeType for the enum itself.
   llvm::DINodeArray EltArray = DBuilder.getOrCreateArray(Enumerators);
 
@@ -3576,7 +3580,7 @@ llvm::DIType *CGDebugInfo::CreateTypeDefinition(const EnumType *Ty) {
   llvm::DIType *ClassTy = getOrCreateType(ED->getIntegerType(), DefUnit);
   return DBuilder.createEnumerationType(
       EnumContext, ED->getName(), DefUnit, Line, Size, Align, EltArray, ClassTy,
-      /*RunTimeLang=*/0, Identifier, ED->isScoped());
+      /*RunTimeLang=*/0, Identifier, ED->isScoped(), EnumKind);
 }
 
 llvm::DIMacro *CGDebugInfo::CreateMacro(llvm::DIMacroFile *Parent,
diff --git a/clang/test/CodeGen/debug-info-enum-extensibility.c b/clang/test/CodeGen/debug-info-enum-extensibility.c
new file mode 100644
index 000000000000000..4f8a42bff3f0195
--- /dev/null
+++ b/clang/test/CodeGen/debug-info-enum-extensibility.c
@@ -0,0 +1,49 @@
+// RUN: %clang_cc1 -emit-llvm -debug-info-kind=limited %s -o - | FileCheck %s
+
+// CHECK-NOT:  enumKind
+// CHECK:      !DICompositeType(tag: DW_TAG_enumeration_type, name: "ClosedEnum"
+// CHECK-SAME:                  enumKind: DW_APPLE_ENUM_KIND_Closed)
+// CHECK:      !DICompositeType(tag: DW_TAG_enumeration_type, name: "OpenEnum"
+// CHECK-SAME:                  enumKind: DW_APPLE_ENUM_KIND_Open)
+// CHECK:      !DICompositeType(tag: DW_TAG_enumeration_type, name: "ClosedFlagEnum"
+// CHECK-SAME:                  enumKind: DW_APPLE_ENUM_KIND_Closed)
+// CHECK:      !DICompositeType(tag: DW_TAG_enumeration_type, name: "OpenFlagEnum"
+// CHECK-SAME:                  enumKind: DW_APPLE_ENUM_KIND_Open)
+// CHECK:      !DICompositeType(tag: DW_TAG_enumeration_type, name: "MixedEnum"
+// CHECK-SAME:                  enumKind: DW_APPLE_ENUM_KIND_Open)
+
+enum Enum {
+  E0, E1
+};
+
+enum FlagEnum {
+  FE0 = 1 << 0, FE1 = 1 << 1
+};
+
+enum __attribute__((enum_extensibility(closed))) ClosedEnum {
+  A0, A1
+};
+
+enum __attribute__((enum_extensibility(open))) OpenEnum {
+  B0, B1
+};
+
+enum __attribute__((enum_extensibility(closed),flag_enum)) ClosedFlagEnum {
+  C0 = 1 << 0, C1 = 1 << 1
+};
+
+enum __attribute__((enum_extensibility(open),flag_enum)) OpenFlagEnum {
+  D0 = 1 << 0, D1 = 1 << 1
+};
+
+enum __attribute__((enum_extensibility(open), enum_extensibility(closed))) MixedEnum {
+  M0, M1
+};
+
+enum Enum e;
+enum FlagEnum fe;
+enum ClosedEnum ce;
+enum OpenEnum oe;
+enum ClosedFlagEnum cfe;
+enum OpenFlagEnum ofe;
+enum MixedEnum me;