[clang] [HLSL] Fix debug info generation for RWBuffer types (PR #119041)

[via cfe-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-debuginfo

@llvm/pr-subscribers-clang-codegen

Author: None (joaosaffran)

<details>
<summary>Changes</summary>

This PR fix the debug infor generation for RWBuffer types.
- This implements the [same fix as DXC](https://github.com/microsoft/DirectXShaderCompiler/pull/6296).
- Adds the HLSLAttributedResource debug info generation

Closes #<!-- -->118523 

---
Full diff: https://github.com/llvm/llvm-project/pull/119041.diff


3 Files Affected:

- (modified) clang/lib/CodeGen/CGDebugInfo.cpp (+12-23) 
- (modified) clang/lib/CodeGen/CGDebugInfo.h (+2) 
- (added) clang/test/CodeGenHLSL/debug/rwbuffer_debug_info.hlsl (+11) 


``````````diff
diff --git a/clang/lib/CodeGen/CGDebugInfo.cpp b/clang/lib/CodeGen/CGDebugInfo.cpp
index 60f32f76109e9a..3fb840137bbaf5 100644
--- a/clang/lib/CodeGen/CGDebugInfo.cpp
+++ b/clang/lib/CodeGen/CGDebugInfo.cpp
@@ -2021,28 +2021,10 @@ llvm::DISubroutineType *CGDebugInfo::getOrCreateInstanceMethodType(
   // ThisPtr may be null if the member function has an explicit 'this'
   // parameter.
   if (!ThisPtr.isNull()) {
-    const CXXRecordDecl *RD = ThisPtr->getPointeeCXXRecordDecl();
-    if (isa<ClassTemplateSpecializationDecl>(RD)) {
-      // Create pointer type directly in this case.
-      const PointerType *ThisPtrTy = cast<PointerType>(ThisPtr);
-      uint64_t Size = CGM.getContext().getTypeSize(ThisPtrTy);
-      auto Align = getTypeAlignIfRequired(ThisPtrTy, CGM.getContext());
-      llvm::DIType *PointeeType =
-          getOrCreateType(ThisPtrTy->getPointeeType(), Unit);
-      llvm::DIType *ThisPtrType =
-          DBuilder.createPointerType(PointeeType, Size, Align);
-      TypeCache[ThisPtr.getAsOpaquePtr()].reset(ThisPtrType);
-      // TODO: This and the artificial type below are misleading, the
-      // types aren't artificial the argument is, but the current
-      // metadata doesn't represent that.
-      ThisPtrType = DBuilder.createObjectPointerType(ThisPtrType);
-      Elts.push_back(ThisPtrType);
-    } else {
-      llvm::DIType *ThisPtrType = getOrCreateType(ThisPtr, Unit);
-      TypeCache[ThisPtr.getAsOpaquePtr()].reset(ThisPtrType);
-      ThisPtrType = DBuilder.createObjectPointerType(ThisPtrType);
-      Elts.push_back(ThisPtrType);
-    }
+    llvm::DIType *ThisPtrType = getOrCreateType(ThisPtr, Unit);
+    TypeCache[ThisPtr.getAsOpaquePtr()].reset(ThisPtrType);
+    ThisPtrType = DBuilder.createObjectPointerType(ThisPtrType);
+    Elts.push_back(ThisPtrType);
   }
 
   // Copy rest of the arguments.
@@ -3509,6 +3491,11 @@ llvm::DIType *CGDebugInfo::CreateType(const PipeType *Ty, llvm::DIFile *U) {
   return getOrCreateType(Ty->getElementType(), U);
 }
 
+llvm::DIType *CGDebugInfo::CreateType(const HLSLAttributedResourceType *Ty,
+                                      llvm::DIFile *U) {
+  return getOrCreateType(Ty->getWrappedType(), U);
+}
+
 llvm::DIType *CGDebugInfo::CreateEnumType(const EnumType *Ty) {
   const EnumDecl *ED = Ty->getDecl();
 
@@ -3851,12 +3838,14 @@ llvm::DIType *CGDebugInfo::CreateTypeNode(QualType Ty, llvm::DIFile *Unit) {
 
   case Type::TemplateSpecialization:
     return CreateType(cast<TemplateSpecializationType>(Ty), Unit);
+  case Type::HLSLAttributedResource: {
+    return CreateType(cast<HLSLAttributedResourceType>(Ty), Unit);
+  }
 
   case Type::CountAttributed:
   case Type::Auto:
   case Type::Attributed:
   case Type::BTFTagAttributed:
-  case Type::HLSLAttributedResource:
   case Type::Adjusted:
   case Type::Decayed:
   case Type::DeducedTemplateSpecialization:
diff --git a/clang/lib/CodeGen/CGDebugInfo.h b/clang/lib/CodeGen/CGDebugInfo.h
index 3fd0237a1c61dd..38f73eca561b7e 100644
--- a/clang/lib/CodeGen/CGDebugInfo.h
+++ b/clang/lib/CodeGen/CGDebugInfo.h
@@ -196,6 +196,8 @@ class CGDebugInfo {
   llvm::DIType *CreateType(const PointerType *Ty, llvm::DIFile *F);
   llvm::DIType *CreateType(const BlockPointerType *Ty, llvm::DIFile *F);
   llvm::DIType *CreateType(const FunctionType *Ty, llvm::DIFile *F);
+  llvm::DIType *CreateType(const HLSLAttributedResourceType *Ty,
+                           llvm::DIFile *F);
   /// Get structure or union type.
   llvm::DIType *CreateType(const RecordType *Tyg);
 
diff --git a/clang/test/CodeGenHLSL/debug/rwbuffer_debug_info.hlsl b/clang/test/CodeGenHLSL/debug/rwbuffer_debug_info.hlsl
new file mode 100644
index 00000000000000..705be1af08be23
--- /dev/null
+++ b/clang/test/CodeGenHLSL/debug/rwbuffer_debug_info.hlsl
@@ -0,0 +1,11 @@
+// RUN: %clang  --driver-mode=dxc -Zi -Fc - -T cs_6_3 -O0 %s | FileCheck %s
+
+// CHECK: #dbg_declare(ptr [[ThisReg:%this\..*]], [[ThisMd:![0-9]+]],
+// CHECK-DAG: [[ThisMd]] = !DILocalVariable(name: "this", arg: 1, scope: !{{[0-9]+}}, type: ![[type:[0-9]+]], flags: DIFlagArtificial | DIFlagObjectPointer)
+
+RWBuffer<float4> Out : register(u7, space4);
+
+[numthreads(8,1,1)]
+void main(uint GI : SV_GroupIndex) {
+  Out[GI] = 0;
+}

``````````

</details>


https://github.com/llvm/llvm-project/pull/119041