Method CreateLlvmStructTypeFromFieldTypes

be/src/runtime/descriptors.cc:1640–1660

}

llvm::StructType* TupleDescriptor::CreateLlvmStructTypeFromFieldTypes(
    LlvmCodeGen* codegen, const vector<llvm::Type*>& field_types,
    int parent_slot_offset) const {
  // Construct the struct type. Use the packed layout although not strictly necessary
  // because the fields are already aligned, so LLVM should not add any padding. The
  // fields are already aligned because we order the slots by descending size and only
  // have powers-of-two slot sizes. Note that STRING and TIMESTAMP slots both occupy
  // 16 bytes although their useful payload is only 12 bytes.
  llvm::StructType* tuple_struct = llvm::StructType::get(codegen->context(),
      llvm::ArrayRef<llvm::Type*>(field_types), true);
  DCHECK(tuple_struct != nullptr);
  const llvm::DataLayout& data_layout = codegen->execution_engine()->getDataLayout();
  const llvm::StructLayout* layout = data_layout.getStructLayout(tuple_struct);
  for (SlotDescriptor* slot: slots()) {
    // Verify that the byte offset in the llvm struct matches the tuple offset
    // computed in the FE.
    DCHECK_EQ(layout->getElementOffset(slot->llvm_field_idx()) + parent_slot_offset,
        slot->tuple_offset()) << id_;
  }
  return tuple_struct;
}

string DescriptorTbl::DebugString() const {
  stringstream out;