[spirv] Fixes vk::BufferPointer constructor expression construction. (microsoft#7331)

Constructors are now properly attached to the template class declaration
instead of a specialization.
Closes microsoft#6489 (again).

---------

Co-authored-by: Nathan Gauër <github@keenuts.net>

Author: danbrown-amd

tools/clang/lib/AST/ASTContextHLSL.cpp

@@ -1390,19 +1390,27 @@ CXXRecordDecl *hlsl::DeclareVkBufferPointerType(ASTContext &context,
       DeclarationName(&context.Idents.get("Get")), true);
   CanQualType canQualType =
       recordDecl->getTypeForDecl()->getCanonicalTypeUnqualified();
-  CreateConstructorDeclarationWithParams(
+  auto *copyConstructorDecl = CreateConstructorDeclarationWithParams(
       context, recordDecl, context.VoidTy,
       {context.getRValueReferenceType(canQualType)}, {"bufferPointer"},
-      context.DeclarationNames.getCXXConstructorName(canQualType), false);
-  CreateConstructorDeclarationWithParams(
+      context.DeclarationNames.getCXXConstructorName(canQualType), false, true);
+  auto *addressConstructorDecl = CreateConstructorDeclarationWithParams(
       context, recordDecl, context.VoidTy, {context.UnsignedIntTy}, {"address"},
-      context.DeclarationNames.getCXXConstructorName(canQualType), false);
+      context.DeclarationNames.getCXXConstructorName(canQualType), false, true);
+  hlsl::CreateFunctionTemplateDecl(
+      context, recordDecl, copyConstructorDecl,
+      Builder.getTemplateDecl()->getTemplateParameters()->begin(), 2);
+  hlsl::CreateFunctionTemplateDecl(
+      context, recordDecl, addressConstructorDecl,
+      Builder.getTemplateDecl()->getTemplateParameters()->begin(), 2);
 
   StringRef OpcodeGroup = GetHLOpcodeGroupName(HLOpcodeGroup::HLIntrinsic);
   unsigned Opcode = static_cast<unsigned>(IntrinsicOp::MOP_GetBufferContents);
   methodDecl->addAttr(
       HLSLIntrinsicAttr::CreateImplicit(context, OpcodeGroup, "", Opcode));
   methodDecl->addAttr(HLSLCXXOverloadAttr::CreateImplicit(context));
+  copyConstructorDecl->addAttr(HLSLCXXOverloadAttr::CreateImplicit(context));
+  addressConstructorDecl->addAttr(HLSLCXXOverloadAttr::CreateImplicit(context));
 
   return Builder.completeDefinition();
 }

tools/clang/lib/Sema/SemaExprCXX.cpp

@@ -1057,26 +1057,51 @@ Sema::BuildCXXTypeConstructExpr(TypeSourceInfo *TInfo,
     Expr *Arg = Exprs[0];
 #ifdef ENABLE_SPIRV_CODEGEN
     if (hlsl::IsVKBufferPointerType(Ty) && Arg->getType()->isIntegerType()) {
-      for (auto *ctor : Ty->getAsCXXRecordDecl()->ctors()) {
-        if (auto *functionType = ctor->getType()->getAs<FunctionProtoType>()) {
-          if (functionType->getNumParams() != 1 ||
-              !functionType->getParamType(0)->isIntegerType())
-            continue;
-
-          CanQualType argType = Arg->getType()->getCanonicalTypeUnqualified();
-          if (!Arg->isRValue()) {
-            Arg = ImpCastExprToType(Arg, argType, CK_LValueToRValue).get();
-          }
-          if (argType != Context.UnsignedLongLongTy) {
-            Arg = ImpCastExprToType(Arg, Context.UnsignedLongLongTy,
-                                    CK_IntegralCast)
-                      .get();
-          }
-          return CXXConstructExpr::Create(
-              Context, Ty, TyBeginLoc, ctor, false, {Arg}, false, false, false,
-              false, CXXConstructExpr::ConstructionKind::CK_Complete,
-              SourceRange(LParenLoc, RParenLoc));
+      typedef DeclContext::specific_decl_iterator<FunctionTemplateDecl> ft_iter;
+      auto *recordDecl = Ty->getAsCXXRecordDecl();
+      auto *specDecl = cast<ClassTemplateSpecializationDecl>(recordDecl);
+      auto *templatedDecl =
+          specDecl->getSpecializedTemplate()->getTemplatedDecl();
+      auto functionTemplateDecls =
+          llvm::iterator_range<ft_iter>(ft_iter(templatedDecl->decls_begin()),
+                                        ft_iter(templatedDecl->decls_end()));
+      for (auto *ftd : functionTemplateDecls) {
+        auto *fd = ftd->getTemplatedDecl();
+        if (fd->getNumParams() != 1 ||
+            !fd->getParamDecl(0)->getType()->isIntegerType())
+          continue;
+
+        void *insertPos;
+        auto templateArgs = ftd->getInjectedTemplateArgs();
+        auto *functionDecl = ftd->findSpecialization(templateArgs, insertPos);
+        if (!functionDecl) {
+          DeclarationNameInfo DInfo(ftd->getDeclName(),
+                                    recordDecl->getLocation());
+          auto *templateArgList = TemplateArgumentList::CreateCopy(
+              Context, templateArgs.data(), templateArgs.size());
+          functionDecl = CXXConstructorDecl::Create(
+              Context, recordDecl, Arg->getLocStart(), DInfo, Ty, TInfo, false,
+              false, false, false);
+          functionDecl->setFunctionTemplateSpecialization(ftd, templateArgList,
+                                                          insertPos);
+        } else if (functionDecl->getDeclKind() != Decl::Kind::CXXConstructor) {
+          continue;
+        }
+
+        CanQualType argType = Arg->getType()->getCanonicalTypeUnqualified();
+        if (!Arg->isRValue()) {
+          Arg = ImpCastExprToType(Arg, argType, CK_LValueToRValue).get();
+        }
+        if (argType != Context.UnsignedLongLongTy) {
+          Arg = ImpCastExprToType(Arg, Context.UnsignedLongLongTy,
+                                  CK_IntegralCast)
+                    .get();
         }
+        return CXXConstructExpr::Create(
+            Context, Ty, TyBeginLoc, cast<CXXConstructorDecl>(functionDecl),
+            false, {Arg}, false, false, false, false,
+            CXXConstructExpr::ConstructionKind::CK_Complete,
+            SourceRange(LParenLoc, RParenLoc));
       }
     }
 #endif

tools/clang/test/CodeGenSPIRV/vk.buffer-pointer.from-uint.hlsl

@@ -0,0 +1,46 @@
+// RUN: %dxc -spirv -Od -T cs_6_7 %s | FileCheck %s
+// RUN: %dxc -spirv -Od -T cs_6_7 -DALIGN_16 %s | FileCheck %s
+// RUN: %dxc -spirv -Od -T cs_6_7 -DNO_PC %s | FileCheck %s
+
+// Was getting bogus type errors with the defined changes
+
+#ifdef ALIGN_16
+typedef vk::BufferPointer<uint, 16> BufferType;
+#else
+typedef vk::BufferPointer<uint, 32> BufferType;
+#endif
+#ifndef NO_PC
+struct PushConstantStruct {
+  BufferType push_buffer;
+};
+[[vk::push_constant]] PushConstantStruct push_constant;
+#endif
+
+RWStructuredBuffer<uint> output;
+
+// CHECK: [[INT:%[_0-9A-Za-z]*]] = OpTypeInt 32 1
+// CHECK: [[I0:%[_0-9A-Za-z]*]] = OpConstant [[INT]] 0
+// CHECK: [[UINT:%[_0-9A-Za-z]*]] = OpTypeInt 32 0
+// CHECK: [[U0:%[_0-9A-Za-z]*]] = OpConstant [[UINT]] 0
+// CHECK: [[PPUINT:%[_0-9A-Za-z]*]] = OpTypePointer PhysicalStorageBuffer [[UINT]]
+// CHECK: [[PFPPUINT:%[_0-9A-Za-z]*]] = OpTypePointer Function [[PPUINT]]
+// CHECK: [[PUUINT:%[_0-9A-Za-z]*]] = OpTypePointer Uniform [[UINT]]
+// CHECK: [[OUTPUT:%[_0-9A-Za-z]*]] = OpVariable %{{[_0-9A-Za-z]*}} Uniform
+
+[numthreads(1, 1, 1)]
+void main() {
+  uint64_t addr = 123;
+  vk::BufferPointer<uint, 32> test = vk::BufferPointer<uint, 32>(addr);
+  output[0] = test.Get();
+}
+
+// CHECK: [[TEST:%[_0-9A-Za-z]*]] = OpVariable [[PFPPUINT]] Function
+// CHECK: [[X1:%[_0-9A-Za-z]*]] = OpConvertUToPtr [[PPUINT]]
+// CHECK: OpStore [[TEST]] [[X1]]
+// CHECK: [[X2:%[_0-9A-Za-z]*]] = OpLoad [[PPUINT]] [[TEST]] Aligned 32
+// CHECK: [[X3:%[_0-9A-Za-z]*]] = OpLoad [[UINT]] [[X2]] Aligned 4
+// CHECK: [[X4:%[_0-9A-Za-z]*]] = OpAccessChain [[PUUINT]] [[OUTPUT]] [[I0]] [[U0]]
+// CHECK: OpStore [[X4]] [[X3]]
+// CHECK: OpReturn
+// CHECK: OpFunctionEnd
+