xref: /llvm-project-15.0.7/lldb/tools/debugserver/source/StdStringExtractor.h (revision 76e47d48)

//===-- StdStringExtractor.h ------------------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

#ifndef LLDB_TOOLS_DEBUGSERVER_SOURCE_STDSTRINGEXTRACTOR_H
#define LLDB_TOOLS_DEBUGSERVER_SOURCE_STDSTRINGEXTRACTOR_H

#include <cstdint>
#include <string>


// Based on StringExtractor, with the added limitation that this file should not
// take a dependency on LLVM, as it is used from debugserver.
class StdStringExtractor {
public:
  enum { BigEndian = 0, LittleEndian = 1 };
  // Constructors and Destructors
  StdStringExtractor();
  StdStringExtractor(const char *packet_cstr);
  virtual ~StdStringExtractor();

  // Returns true if the file position is still valid for the data
  // contained in this string extractor object.
  bool IsGood() const { return m_index != UINT64_MAX; }

  uint64_t GetFilePos() const { return m_index; }

  void SetFilePos(uint32_t idx) { m_index = idx; }

  void Clear() {
    m_packet.clear();
    m_index = 0;
  }

  void SkipSpaces();

  const std::string &GetStringRef() const { return m_packet; }

  bool Empty() { return m_packet.empty(); }

  size_t GetBytesLeft() {
    if (m_index < m_packet.size())
      return m_packet.size() - m_index;
    return 0;
  }

  char GetChar(char fail_value = '\0');

  char PeekChar(char fail_value = '\0') {
    const char *cstr = Peek();
    if (cstr)
      return cstr[0];
    return fail_value;
  }

  int DecodeHexU8();

  uint8_t GetHexU8(uint8_t fail_value = 0, bool set_eof_on_fail = true);

  bool GetHexU8Ex(uint8_t &ch, bool set_eof_on_fail = true);

  bool GetNameColonValue(std::string &name, std::string &value);

  int32_t GetS32(int32_t fail_value, int base = 0);

  uint32_t GetU32(uint32_t fail_value, int base = 0);

  int64_t GetS64(int64_t fail_value, int base = 0);

  uint64_t GetU64(uint64_t fail_value, int base = 0);

  uint32_t GetHexMaxU32(bool little_endian, uint32_t fail_value);

  uint64_t GetHexMaxU64(bool little_endian, uint64_t fail_value);

  size_t GetHexBytes(void *dst, size_t dst_len, uint8_t fail_fill_value);

  size_t GetHexBytesAvail(void *dst, size_t dst_len);

  size_t GetHexByteString(std::string &str);

  size_t GetHexByteStringFixedLength(std::string &str, uint32_t nibble_length);

  size_t GetHexByteStringTerminatedBy(std::string &str, char terminator);

  const char *Peek() {
    if (m_index < m_packet.size())
      return m_packet.c_str() + m_index;
    return nullptr;
  }

protected:
  // For StdStringExtractor only
  std::string m_packet; // The string in which to extract data.
  uint64_t m_index;     // When extracting data from a packet, this index
                        // will march along as things get extracted. If set
                        // to UINT64_MAX the end of the packet data was
                        // reached when decoding information
};

#endif // LLDB_TOOLS_DEBUGSERVER_SOURCE_STDSTRINGEXTRACTOR_H