Method parseFunctionBody

src/lib/Bitcode/Reader/BitcodeReader.cpp:3411–4721

Lazily parse the specified function body block.

/// Lazily parse the specified function body block.
Error BitcodeReader::parseFunctionBody(Function *F) {
  if (Stream.EnterSubBlock(bitc::FUNCTION_BLOCK_ID))
    return error("Invalid record");

  // Unexpected unresolved metadata when parsing function.
  if (MDLoader->hasFwdRefs())
    return error("Invalid function metadata: incoming forward references");

  InstructionList.clear();
  unsigned ModuleValueListSize = ValueList.size();
  unsigned ModuleMDLoaderSize = MDLoader->size();

  // Add all the function arguments to the value table.
  for (Argument &I : F->args())
    ValueList.push_back(&I);

  unsigned NextValueNo = ValueList.size();
  BasicBlock *CurBB = nullptr;
  unsigned CurBBNo = 0;

  DebugLoc LastLoc;
  auto getLastInstruction = [&]() -> Instruction * {
    if (CurBB && !CurBB->empty())
      return &CurBB->back();
    else if (CurBBNo && FunctionBBs[CurBBNo - 1] &&
             !FunctionBBs[CurBBNo - 1]->empty())
      return &FunctionBBs[CurBBNo - 1]->back();
    return nullptr;
  };

  std::vector<OperandBundleDef> OperandBundles;

  // Read all the records.
  SmallVector<uint64_t, 64> Record;

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

    switch (Entry.Kind) {
    case BitstreamEntry::Error:
      return error("Malformed block");
    case BitstreamEntry::EndBlock:
      goto OutOfRecordLoop;

    case BitstreamEntry::SubBlock:
      switch (Entry.ID) {
      default:  // Skip unknown content.
        if (Stream.SkipBlock())
          return error("Invalid record");
        break;
      case bitc::CONSTANTS_BLOCK_ID:
        if (Error Err = parseConstants())
          return Err;
        NextValueNo = ValueList.size();
        break;
      case bitc::VALUE_SYMTAB_BLOCK_ID:
        if (Error Err = parseValueSymbolTable())
          return Err;