Class DebugInfoWriter

lib/Bytecode/Writer/BytecodeWriter.cpp:581–906

This class manages writing debug info attributes to bytecode format.

/// This class manages writing debug info attributes to bytecode format.
class DebugInfoWriter {
public:
  DebugInfoWriter(StringManager &strMgr) : strMgr(strMgr) {}

  /// This method gets or creates an index for an operation.
  uint64_t getOpIndex(Operation *op) {
    auto it = opIndexMap.find(op);
    if (it != opIndexMap.end())
      return it->second;

    // Check if the operation location has a reserved index and return it.
    auto reserved = getDebugReserved(op->getLoc());
    if (reserved != Bytecode::DebugReserved::SIZE)
      return static_cast<uint64_t>(reserved);

    // Adjust the index to account for reserved indices.
    uint64_t opIndex = opIndexMap.size() +
                       static_cast<uint64_t>(Bytecode::DebugReserved::SIZE);

    opIndexMap[op] = opIndex;
    return opIndex;
  }

  /// This method adds a debug info attribute to an operation.
  void addDebugInfo(uint64_t opIndex, Attribute attr) {
    // Nothing to do if the operation has a reserved index.
    if (opIndex < static_cast<uint64_t>(Bytecode::DebugReserved::SIZE))
      return;

    // Adjust the index to account for reserved indices.
    opIndex -= static_cast<uint64_t>(Bytecode::DebugReserved::SIZE);

    if (opIndex >= debuginfoIndices.size())
      debuginfoIndices.resize(opIndex + 1);
    debuginfoIndices[opIndex].push_back(getDebugInfoIndex(attr));
  }

  // debuginfo-section =:
  //   diOpsNum[varint]          // Total number of operations with debug info
  //   padding[bytes]            // Align to 4 bytes
  //   diIndexOffsets[uint32_t]  // Per op offset into the debug info indices
  //   diIndicesNum[varint]      // Total number of debug info indices
  //   padding[bytes]            // Align to 8 bytes
  //   diIndices[uint64_t]       // Array of debug indices to debug info
  //   attributes diAttrNum[varint]         // Total number of debug info
  //   attributes padding[bytes]            // Align to 4 bytes
  //   diOffsets[uint32_t]       // Per debug info attribute offset into the
  //   debug info data diData[bytes]             // Data for each debug info
  //   attribute
  //
  // diData =:
  //   DebugTag[byte]            // Indicates the debug info attribute type
  //   debuginfo-encoding        // Format depends on DebugTag
  LogicalResult writeDebugInfoSection(raw_ostream &stream) {
    // Skip writing the section if there are no debug info attributes.
    if (debuginfoIndices.empty() && debuginfoList.empty())
      return success();