C++ (Cpp) DataReader::HasOverflow示例

status_t
AbbreviationTable::_ParseAbbreviationEntry(DataReader& abbrevReader,
	bool& _nullEntry)
{
	uint32 code = abbrevReader.ReadUnsignedLEB128(0);
	if (code == 0) {
		if (abbrevReader.HasOverflow()) {
			fprintf(stderr, "Invalid abbreviation table 1!\n");
			return B_BAD_DATA;
		}
		_nullEntry = true;
		return B_OK;
	}

	off_t remaining = abbrevReader.BytesRemaining();

/*	uint32 tag =*/ abbrevReader.ReadUnsignedLEB128(0);
/*	uint8 hasChildren =*/ abbrevReader.Read<uint8>(DW_CHILDREN_no);

//	printf("entry: %lu, tag: %lu, children: %d\n", code, tag,
//		hasChildren);

	// parse attribute specifications
	while (true) {
		uint32 attributeName = abbrevReader.ReadUnsignedLEB128(0);
		uint32 attributeForm = abbrevReader.ReadUnsignedLEB128(0);
		if (abbrevReader.HasOverflow()) {
			fprintf(stderr, "Invalid abbreviation table 2!\n");
			return B_BAD_DATA;
		}

		if (attributeName == 0 && attributeForm == 0)
			break;

//		printf("  attr: name: %lu, form: %lu\n", attributeName,
//			attributeForm);
	}

	// create the entry
	if (fEntryTable.Lookup(code) == NULL) {
		AbbreviationTableEntry* entry = new(std::nothrow)
			AbbreviationTableEntry(code, fSize - remaining,
				remaining - abbrevReader.BytesRemaining());
		if (entry == NULL)
			return B_NO_MEMORY;

		fEntryTable.Insert(entry);
	} else
		fprintf(stderr, "Duplicate abbreviation table entry %lu!\n", code);

	_nullEntry = false;
	return B_OK;
}