//===- TranslateRegistration.cpp - hooks to mlir-translate ----------------===//
//
// Copyright 2019 The MLIR Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//   http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// =============================================================================
//
// This file implements a translation from SPIR-V binary module to MLIR SPIR-V
// ModuleOp.
//
//===----------------------------------------------------------------------===//

#include "mlir/Dialect/SPIRV/SPIRVOps.h"
#include "mlir/Dialect/SPIRV/Serialization.h"
#include "mlir/IR/Builders.h"
#include "mlir/IR/Function.h"
#include "mlir/IR/Module.h"
#include "mlir/Parser.h"
#include "mlir/Support/FileUtilities.h"
#include "mlir/Translation.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/SMLoc.h"
#include "llvm/Support/SourceMgr.h"
#include "llvm/Support/ToolOutputFile.h"

using namespace mlir;

//===----------------------------------------------------------------------===//
// Deserialization registration
//===----------------------------------------------------------------------===//

// Deserializes the SPIR-V binary module stored in the file named as
// `inputFilename` and returns a module containing the SPIR-V module.
OwningModuleRef deserializeModule(std::unique_ptr<llvm::MemoryBuffer> input,
                                  MLIRContext *context) {
  Builder builder(context);

  // Make sure the input stream can be treated as a stream of SPIR-V words
  auto start = input->getBufferStart();
  auto size = input->getBufferSize();
  if (size % sizeof(uint32_t) != 0) {
    emitError(UnknownLoc::get(context))
        << "SPIR-V binary module must contain integral number of 32-bit words";
    return {};
  }

  auto binary = llvm::makeArrayRef(reinterpret_cast<const uint32_t *>(start),
                                   size / sizeof(uint32_t));

  auto spirvModule = spirv::deserialize(binary, context);
  if (!spirvModule)
    return {};

  OwningModuleRef module(ModuleOp::create(FileLineColLoc::get(
      input->getBufferIdentifier(), /*line=*/0, /*column=*/0, context)));
  module->getBody()->push_front(spirvModule->getOperation());

  return module;
}

static TranslateToMLIRRegistration fromBinary(
    "deserialize-spirv",
    [](std::unique_ptr<llvm::MemoryBuffer> input, MLIRContext *context) {
      return deserializeModule(std::move(input), context);
    });

//===----------------------------------------------------------------------===//
// Serialization registration
//===----------------------------------------------------------------------===//

LogicalResult serializeModule(ModuleOp module, llvm::raw_ostream &output) {
  if (!module)
    return failure();

  SmallVector<uint32_t, 0> binary;

  auto spirvModules = module.getOps<spirv::ModuleOp>();

  if (spirvModules.begin() == spirvModules.end())
    return module.emitError("found no 'spv.module' op");

  if (std::next(spirvModules.begin()) != spirvModules.end())
    return module.emitError("found more than one 'spv.module' op");

  if (failed(spirv::serialize(*spirvModules.begin(), binary)))
    return failure();

  output.write(reinterpret_cast<char *>(binary.data()),
               binary.size() * sizeof(uint32_t));

  return mlir::success();
}

static TranslateFromMLIRRegistration
    toBinary("serialize-spirv", [](ModuleOp module, llvm::raw_ostream &output) {
      return serializeModule(module, output);
    });

//===----------------------------------------------------------------------===//
// Round-trip registration
//===----------------------------------------------------------------------===//

LogicalResult roundTripModule(std::unique_ptr<llvm::MemoryBuffer> input,
                              llvm::raw_ostream &output, MLIRContext *context) {
  llvm::SourceMgr sourceMgr;
  sourceMgr.AddNewSourceBuffer(std::move(input), llvm::SMLoc());
  SourceMgrDiagnosticHandler sourceMgrHandler(sourceMgr, context);

  // Parse the memory buffer as a MLIR module.
  auto srcModule = OwningModuleRef(parseSourceFile(sourceMgr, context));
  if (!srcModule)
    return failure();

  SmallVector<uint32_t, 0> binary;

  auto spirvModules = srcModule->getOps<spirv::ModuleOp>();

  if (spirvModules.begin() == spirvModules.end())
    return srcModule->emitError("found no 'spv.module' op");

  if (std::next(spirvModules.begin()) != spirvModules.end())
    return srcModule->emitError("found more than one 'spv.module' op");

  if (failed(spirv::serialize(*spirvModules.begin(), binary)))
    return failure();

  // Then deserialize to get back a SPIR-V module.
  auto spirvModule = spirv::deserialize(binary, context);
  if (!spirvModule)
    return failure();

  // Wrap around in a new MLIR module.
  OwningModuleRef dstModule(ModuleOp::create(FileLineColLoc::get(
      /*filename=*/"", /*line=*/0, /*column=*/0, context)));
  dstModule->getBody()->push_front(spirvModule->getOperation());
  dstModule->print(output);

  return mlir::success();
}

static TranslateRegistration
    roundtrip("test-spirv-roundtrip",
              [](std::unique_ptr<llvm::MemoryBuffer> input,
                 llvm::raw_ostream &output, MLIRContext *context) {
                return roundTripModule(std::move(input), output, context);
              });