[llvm] [SYCL][LLVM] Adding property set I/O library for SYCL (PR #110771)

[Arvind Sudarsanam via llvm-commits]

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+//=- SYCLPropertySetIO.h -- models a sequence of property sets and their I/O =//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+// Models a sequence of property sets and their input and output operations.
+// SYCLPropertyValue set format:
+//   '['<SYCLPropertyValue set name>']'
+//   <property name>=<property type>'|'<property value>
+//   <property name>=<property type>'|'<property value>
+//   ...
+//   '['<SYCLPropertyValue set name>']'
+//   <property name>=<property type>'|'<property value>
+// where
+//   <SYCLPropertyValue set name>, <property name> are strings
+//   <property type> - string representation of the property type
+//   <property value> - string representation of the property value.
+//
+// For example:
+// [Staff/Ages]
+// person1=1|20
+// person2=1|25
+// [Staff/Experience]
+// person1=1|1
+// person2=1|2
+// person3=1|12
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_SUPPORT_SYCLPROPERTYSETIO_H
+#define LLVM_SUPPORT_SYCLPROPERTYSETIO_H
+
+#include "llvm/ADT/MapVector.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/Support/Error.h"
+#include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Support/xxhash.h"
+#include <variant>
+
+namespace llvm {
+namespace util {
+
+// Represents a SYCL property value. SYCLPropertyValue name is stored in the
+// encompassing container.
+class SYCLPropertyValue {
+public:
+  // Type of the size of the value. Value size gets serialized along with the
+  // value data in some cases for later reading at runtime, so size_t is not
+  // suitable as its size varies.
+  using SizeTy = uint64_t;
+
+  // Defines supported property types
+  enum Type { first = 0, None = first, UInt32, ByteArray, last = ByteArray };
+
+  // Translates C++ type to the corresponding type tag.
+  template <typename T> static Type getTypeTag();
+
+  // Casts from int value to a type tag.
+  static Expected<Type> getTypeTag(int T) {
+    if (T < first || T > last)
+      return createStringError(std::error_code(), "bad property type ", T);
+    return static_cast<Type>(T);
+  }
+
+  ~SYCLPropertyValue() {
+    if (std::holds_alternative<std::byte *>(Val)) {
+      auto ByteArrayVal = std::get<std::byte *>(Val);
+      if (ByteArrayVal)
+        delete[] ByteArrayVal;
+    }
+  }
+  SYCLPropertyValue() = default;
+
+  SYCLPropertyValue(Type Ty) {
+    if (Ty == UInt32)
+      Val = (uint32_t)0;
+    else if (Ty == ByteArray)
+      Val = (std::byte *)(0);
+    else
+      llvm_unreachable_internal("unsupported SYCL property type");
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asudarsa wrote:

Used switch-case instead of if-then-else. Thanks

https://github.com/llvm/llvm-project/pull/110771