[llvm] [SYCL] Add platform enumeration and info query using liboffload (PR #166927)

[Kseniya Tikhomirova via llvm-commits]

================
@@ -0,0 +1,116 @@
+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// This file contains the declaration of the SYCL 2020 Exception class
+/// interface (4.13.2.)
+///
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBSYCL___IMPL_EXCEPTION_HPP
+#define _LIBSYCL___IMPL_EXCEPTION_HPP
+
+#include <sycl/__impl/detail/config.hpp>
+
+#include <exception>
+#include <memory>
+#include <string>
+#include <system_error>
+#include <type_traits>
+#include <vector>
+
+_LIBSYCL_BEGIN_NAMESPACE_SYCL
+
+class context;
+
+enum class errc : int {
+  success = 0,
+  runtime = 1,
+  kernel = 2,
+  accessor = 3,
+  nd_range = 4,
+  event = 5,
+  kernel_argument = 6,
+  build = 7,
+  invalid = 8,
+  memory_allocation = 9,
+  platform = 10,
+  profiling = 11,
+  feature_not_supported = 12,
+  kernel_not_supported = 13,
+  backend_mismatch = 14,
+};
+
+/// Constructs an error code using E and sycl_category()
+_LIBSYCL_EXPORT std::error_code make_error_code(sycl::errc E) noexcept;
+
+/// Obtains a reference to the static error category object for SYCL errors.
+_LIBSYCL_EXPORT const std::error_category &sycl_category() noexcept;
+
+// Derive from std::exception so uncaught exceptions are printed in c++ default
+// exception handler.
+// Virtual inheritance is mandated by SYCL 2020.
+// 4.13.2. Exception class interface
+class _LIBSYCL_EXPORT exception : public virtual std::exception {
+public:
+  exception(std::error_code, const char *);
+  exception(std::error_code Ec, const std::string &Msg)
+      : exception(Ec, Msg.c_str()) {}
+
+  exception(std::error_code EC) : exception(EC, "") {}
+  exception(int EV, const std::error_category &ECat, const std::string &WhatArg)
+      : exception(EV, ECat, WhatArg.c_str()) {}
+  exception(int EV, const std::error_category &ECat, const char *WhatArg)
+      : exception({EV, ECat}, WhatArg) {}
+  exception(int EV, const std::error_category &ECat)
+      : exception({EV, ECat}, "") {}
+
----------------
KseniyaTikhomirova wrote:

I have received right the opposite comment from another reviewer when I left other methods commented out.
I want to suggest to leave it at it is for now. There are (and will) more things that I can't implement right here, right now (e.g. full list of device info, etc) and it will bring a mess into code base to track these gaps here. In the next PR for device impl I am adding high level list of missed items where this gap is already mentioned. So it shoulnd't be lost.
https://github.com/KseniyaTikhomirova/llvm-project/pull/3/files#diff-e122f118f7e566d443f20bc82a475cbd291333a03b17a2d44b7b9d134dc45d80R87

https://github.com/llvm/llvm-project/pull/166927