Function getEnableSplitLTOUnitFlag

src/lib/Bitcode/Reader/BitcodeReader.cpp:5932–5970

}

static Expected<bool> getEnableSplitLTOUnitFlag(BitstreamCursor &Stream,
                                                unsigned ID) {
  if (Stream.EnterSubBlock(ID))
    return error("Invalid record");
  SmallVector<uint64_t, 64> Record;

  while (true) {
    BitstreamEntry Entry = Stream.advanceSkippingSubblocks();

    switch (Entry.Kind) {
    case BitstreamEntry::SubBlock: // Handled for us already.
    case BitstreamEntry::Error:
      return error("Malformed block");
    case BitstreamEntry::EndBlock:
      // If no flags record found, conservatively return true to mimic
      // behavior before this flag was added.
      return true;
    case BitstreamEntry::Record:
      // The interesting case.
      break;
    }

    // Look for the FS_FLAGS record.
    Record.clear();
    auto BitCode = Stream.readRecord(Entry.ID, Record);
    switch (BitCode) {
    default: // Default behavior: ignore.
      break;
    case bitc::FS_FLAGS: { // [flags]
      uint64_t Flags = Record[0];
      // Scan flags.
      assert(Flags <= 0x1f && "Unexpected bits in flag");

      return Flags & 0x8;
    }
    }
  }
  llvm_unreachable("Exit infinite loop");
}

// Check if the given bitcode buffer contains a global value summary block.
Expected<BitcodeLTOInfo> BitcodeModule::getLTOInfo() {