[clang] [HLSL] Constant buffers codegen (PR #124886)

[Helena Kotas via cfe-commits]

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@@ -0,0 +1,39 @@
+//===- HLSLTargetInfo.h ---------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "ABIInfoImpl.h"
+#include "TargetInfo.h"
+
+using namespace clang;
+using namespace clang::CodeGen;
+
+//===----------------------------------------------------------------------===//
+// Target codegen info implementation common between DirectX and SPIR/SPIR-V.
+//===----------------------------------------------------------------------===//
+
+class CommonHLSLTargetCodeGenInfo : public TargetCodeGenInfo {
+public:
+  CommonHLSLTargetCodeGenInfo(std::unique_ptr<ABIInfo> Info)
+      : TargetCodeGenInfo(std::move(Info)) {}
+
+  // Returns LLVM target extension type "dx.Layout" or "spv.Layout"
+  // for given structure type and layout data. The first number in
+  // the Layout is the size followed by offsets for each struct element.
+  virtual llvm::Type *getHLSLLayoutType(CodeGenModule &CGM,
+                                        llvm::StructType *LayoutStructTy,
+                                        SmallVector<unsigned> Layout) const {
+    return nullptr;
+  };
+
+protected:
+  // Creates a layout type for given struct with HLSL constant buffer layout
+  // taking into account Packoffsets, if provided.
+  virtual llvm::Type *createHLSLBufferLayoutType(
+      CodeGenModule &CGM, const clang::RecordType *StructType,
+      const SmallVector<unsigned> *Packoffsets = nullptr) const;
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hekota wrote:

I have moved the layout calculations to a separate `HLSLBufferLayoutBuilder` class outside of the target info class hierarchy. This method is no longer needed.

https://github.com/llvm/llvm-project/pull/124886