/*

 * Copyright (c) Meta Platforms, Inc. and affiliates.

 *

 * This source code is licensed under the MIT license found in the

 * LICENSE file in the root directory of this source tree.

 */

#include "hermes/BCGen/HBC/Bytecode.h"

#include "hermes/SourceMap/SourceMapGenerator.h"

#include "llvh/ADT/SmallVector.h"

using namespace hermes;

using namespace hbc;

void BytecodeModule::setFunction(

    uint32_t index,

    std::unique_ptr<BytecodeFunction> F) {

  assert(index < getNumFunctions() && "Function ID out of bound");

  functions_[index] = std::move(F);

}

BytecodeFunction &BytecodeModule::getFunction(unsigned index) {

  assert(index < getNumFunctions() && "Function ID out of bound");

  assert(functions_[index] && "Invalid function");

  return *functions_[index];

}

void BytecodeModule::populateSourceMap(SourceMapGenerator *sourceMap) const {

  /// Construct a list of virtual function offsets, and pass it to DebugInfo to

  /// help it populate the source map.

  std::vector<uint32_t> functionOffsets;

  functionOffsets.reserve(functions_.size());

  uint32_t offset = 0;

  for (const auto &func : functions_) {

    functionOffsets.push_back(offset);

    offset += func->getHeader().bytecodeSizeInBytes;

  }

  debugInfo_.populateSourceMap(

      sourceMap, std::move(functionOffsets), segmentID_);

}

ArrayRef<uint32_t> BytecodeFunction::getJumpTablesOnly() const {

  // The jump tables (if there are any) start at the nearest 4-byte boundary

  // from the end of the opcodes.

  uint32_t jumpTableStartIdx =

      llvh::alignTo<sizeof(uint32_t)>(header_.bytecodeSizeInBytes);

  if (jumpTableStartIdx > opcodesAndJumpTables_.size()) {

    return {};

  }

  uint32_t jumpTableBytes = opcodesAndJumpTables_.size() - jumpTableStartIdx;

  assert(jumpTableBytes % sizeof(uint32_t) == 0);

  uint32_t jumpTableSize = jumpTableBytes / sizeof(uint32_t);

  const uint32_t *jumpTableStart = reinterpret_cast<const uint32_t *>(

      opcodesAndJumpTables_.data() + jumpTableStartIdx);

  return {jumpTableStart, jumpTableSize};

}