// Protocol Buffers - Google's data interchange format

// Copyright 2008 Google Inc.  All rights reserved.

// https://developers.google.com/protocol-buffers/

//

// Redistribution and use in source and binary forms, with or without

// modification, are permitted provided that the following conditions are

// met:

//

//     * Redistributions of source code must retain the above copyright

// notice, this list of conditions and the following disclaimer.

//     * Redistributions in binary form must reproduce the above

// copyright notice, this list of conditions and the following disclaimer

// in the documentation and/or other materials provided with the

// distribution.

//     * Neither the name of Google Inc. nor the names of its

// contributors may be used to endorse or promote products derived from

// this software without specific prior written permission.

//

// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR

// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT

// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

#ifndef GOOGLE_PROTOBUF_PARSE_CONTEXT_H__

#define GOOGLE_PROTOBUF_PARSE_CONTEXT_H__

#include <cstdint>

#include <cstring>

#include <string>

#include <type_traits>

#include <google/protobuf/io/coded_stream.h>

#include <google/protobuf/io/zero_copy_stream.h>

#include <google/protobuf/arena.h>

#include <google/protobuf/port.h>

#include <google/protobuf/stubs/strutil.h>

#include <google/protobuf/arenastring.h>

#include <google/protobuf/endian.h>

#include <google/protobuf/implicit_weak_message.h>

#include <google/protobuf/inlined_string_field.h>

#include <google/protobuf/metadata_lite.h>

#include <google/protobuf/repeated_field.h>

#include <google/protobuf/wire_format_lite.h>

// Must be included last.

#include <google/protobuf/port_def.inc>

namespace google {

namespace protobuf {

class UnknownFieldSet;

class DescriptorPool;

class MessageFactory;

namespace internal {

// Template code below needs to know about the existence of these functions.

PROTOBUF_EXPORT void WriteVarint(uint32_t num, uint64_t val, std::string* s);

PROTOBUF_EXPORT void WriteLengthDelimited(uint32_t num, StringPiece val,

                                          std::string* s);

// Inline because it is just forwarding to s->WriteVarint

inline void WriteVarint(uint32_t num, uint64_t val, UnknownFieldSet* s);

inline void WriteLengthDelimited(uint32_t num, StringPiece val,

                                 UnknownFieldSet* s);

// The basic abstraction the parser is designed for is a slight modification

// of the ZeroCopyInputStream (ZCIS) abstraction. A ZCIS presents a serialized

// stream as a series of buffers that concatenate to the full stream.

// Pictorially a ZCIS presents a stream in chunks like so

// [---------------------------------------------------------------]

// [---------------------] chunk 1

//                      [----------------------------] chunk 2

//                                          chunk 3 [--------------]

//

// Where the '-' represent the bytes which are vertically lined up with the

// bytes of the stream. The proto parser requires its input to be presented

// similarly with the extra

// property that each chunk has kSlopBytes past its end that overlaps with the

// first kSlopBytes of the next chunk, or if there is no next chunk at least its

// still valid to read those bytes. Again, pictorially, we now have

//

// [---------------------------------------------------------------]

// [-------------------....] chunk 1

//                    [------------------------....] chunk 2

//                                    chunk 3 [------------------..**]

//                                                      chunk 4 [--****]

// Here '-' mean the bytes of the stream or chunk and '.' means bytes past the

// chunk that match up with the start of the next chunk. Above each chunk has

// 4 '.' after the chunk. In the case these 'overflow' bytes represents bytes

// past the stream, indicated by '*' above, their values are unspecified. It is

// still legal to read them (ie. should not segfault). Reading past the

// end should be detected by the user and indicated as an error.

//

// The reason for this, admittedly, unconventional invariant is to ruthlessly

// optimize the protobuf parser. Having an overlap helps in two important ways.

// Firstly it alleviates having to performing bounds checks if a piece of code

// is guaranteed to not read more than kSlopBytes. Secondly, and more

// importantly, the protobuf wireformat is such that reading a key/value pair is

// always less than 16 bytes. This removes the need to change to next buffer in

// the middle of reading primitive values. Hence there is no need to store and

// load the current position.

class PROTOBUF_EXPORT EpsCopyInputStream {

 public:

  enum { kSlopBytes = 16, kMaxCordBytesToCopy = 512 };

  explicit EpsCopyInputStream(bool enable_aliasing)

      : aliasing_(enable_aliasing ? kOnPatch : kNoAliasing) {}

  void BackUp(const char* ptr) {

    GOOGLE_DCHECK(ptr <= buffer_end_ + kSlopBytes);

    int count;

    if (next_chunk_ == buffer_) {

      count = static_cast<int>(buffer_end_ + kSlopBytes - ptr);

    } else {

      count = size_ + static_cast<int>(buffer_end_ - ptr);

    }

    if (count > 0) StreamBackUp(count);

  }

  // If return value is negative it's an error

  PROTOBUF_NODISCARD int PushLimit(const char* ptr, int limit) {

    GOOGLE_DCHECK(limit >= 0 && limit <= INT_MAX - kSlopBytes);

    // This add is safe due to the invariant above, because

    // ptr - buffer_end_ <= kSlopBytes.

    limit += static_cast<int>(ptr - buffer_end_);

    limit_end_ = buffer_end_ + (std::min)(0, limit);

    auto old_limit = limit_;

    limit_ = limit;

    return old_limit - limit;

  }

  PROTOBUF_NODISCARD bool PopLimit(int delta) {

    if (PROTOBUF_PREDICT_FALSE(!EndedAtLimit())) return false;

    limit_ = limit_ + delta;

    // TODO(gerbens) We could remove this line and hoist the code to

    // DoneFallback. Study the perf/bin-size effects.

    limit_end_ = buffer_end_ + (std::min)(0, limit_);

    return true;

  }

  PROTOBUF_NODISCARD const char* Skip(const char* ptr, int size) {

    if (size <= buffer_end_ + kSlopBytes - ptr) {

      return ptr + size;

    }

    return SkipFallback(ptr, size);

  }

  PROTOBUF_NODISCARD const char* ReadString(const char* ptr, int size,

                                            std::string* s) {

    if (size <= buffer_end_ + kSlopBytes - ptr) {

      s->assign(ptr, size);

      return ptr + size;

    }

    return ReadStringFallback(ptr, size, s);

  }

  PROTOBUF_NODISCARD const char* AppendString(const char* ptr, int size,

                                              std::string* s) {

    if (size <= buffer_end_ + kSlopBytes - ptr) {

      s->append(ptr, size);

      return ptr + size;

    }

    return AppendStringFallback(ptr, size, s);

  }

  // Implemented in arenastring.cc

  PROTOBUF_NODISCARD const char* ReadArenaString(const char* ptr,

                                                 ArenaStringPtr* s,

                                                 Arena* arena);

  template <typename Tag, typename T>

  PROTOBUF_NODISCARD const char* ReadRepeatedFixed(const char* ptr,

                                                   Tag expected_tag,

                                                   RepeatedField<T>* out);

  template <typename T>

  PROTOBUF_NODISCARD const char* ReadPackedFixed(const char* ptr, int size,

                                                 RepeatedField<T>* out);

  template <typename Add>

  PROTOBUF_NODISCARD const char* ReadPackedVarint(const char* ptr, Add add);

  uint32_t LastTag() const { return last_tag_minus_1_ + 1; }

  bool ConsumeEndGroup(uint32_t start_tag) {

    bool res = last_tag_minus_1_ == start_tag;

    last_tag_minus_1_ = 0;

    return res;

  }

  bool EndedAtLimit() const { return last_tag_minus_1_ == 0; }

  bool EndedAtEndOfStream() const { return last_tag_minus_1_ == 1; }

  void SetLastTag(uint32_t tag) { last_tag_minus_1_ = tag - 1; }

  void SetEndOfStream() { last_tag_minus_1_ = 1; }

  bool IsExceedingLimit(const char* ptr) {

    return ptr > limit_end_ &&

           (next_chunk_ == nullptr || ptr - buffer_end_ > limit_);

  }

  bool AliasingEnabled() const { return aliasing_ != kNoAliasing; }

  int BytesUntilLimit(const char* ptr) const {

    return limit_ + static_cast<int>(buffer_end_ - ptr);

  }

  // Returns true if more data is available, if false is returned one has to

  // call Done for further checks.

  bool DataAvailable(const char* ptr) { return ptr < limit_end_; }

 protected:

  // Returns true is limit (either an explicit limit or end of stream) is

  // reached. It aligns *ptr across buffer seams.

  // If limit is exceeded it returns true and ptr is set to null.

  bool DoneWithCheck(const char** ptr, int d) {

    GOOGLE_DCHECK(*ptr);

    if (PROTOBUF_PREDICT_TRUE(*ptr < limit_end_)) return false;

    int overrun = static_cast<int>(*ptr - buffer_end_);

    GOOGLE_DCHECK_LE(overrun, kSlopBytes);  // Guaranteed by parse loop.

    if (overrun ==

        limit_) {  //  No need to flip buffers if we ended on a limit.

      // If we actually overrun the buffer and next_chunk_ is null. It means

      // the stream ended and we passed the stream end.

      if (overrun > 0 && next_chunk_ == nullptr) *ptr = nullptr;

      return true;

    }

    auto res = DoneFallback(overrun, d);

    *ptr = res.first;

    return res.second;

  }

  const char* InitFrom(StringPiece flat) {

    overall_limit_ = 0;

    if (flat.size() > kSlopBytes) {

      limit_ = kSlopBytes;

      limit_end_ = buffer_end_ = flat.data() + flat.size() - kSlopBytes;

      next_chunk_ = buffer_;

      if (aliasing_ == kOnPatch) aliasing_ = kNoDelta;

      return flat.data();

    } else {

      std::memcpy(buffer_, flat.data(), flat.size());

      limit_ = 0;

      limit_end_ = buffer_end_ = buffer_ + flat.size();

      next_chunk_ = nullptr;

      if (aliasing_ == kOnPatch) {

        aliasing_ = reinterpret_cast<std::uintptr_t>(flat.data()) -

                    reinterpret_cast<std::uintptr_t>(buffer_);

      }

      return buffer_;

    }

  }

  const char* InitFrom(io::ZeroCopyInputStream* zcis);

  const char* InitFrom(io::ZeroCopyInputStream* zcis, int limit) {

    if (limit == -1) return InitFrom(zcis);

    overall_limit_ = limit;

    auto res = InitFrom(zcis);

    limit_ = limit - static_cast<int>(buffer_end_ - res);

    limit_end_ = buffer_end_ + (std::min)(0, limit_);

    return res;

  }

 private:

  const char* limit_end_;  // buffer_end_ + min(limit_, 0)

  const char* buffer_end_;

  const char* next_chunk_;

  int size_;

  int limit_;  // relative to buffer_end_;

  io::ZeroCopyInputStream* zcis_ = nullptr;

  char buffer_[2 * kSlopBytes] = {};

  enum { kNoAliasing = 0, kOnPatch = 1, kNoDelta = 2 };

  std::uintptr_t aliasing_ = kNoAliasing;

  // This variable is used to communicate how the parse ended, in order to

  // completely verify the parsed data. A wire-format parse can end because of

  // one of the following conditions:

  // 1) A parse can end on a pushed limit.

  // 2) A parse can end on End Of Stream (EOS).

  // 3) A parse can end on 0 tag (only valid for toplevel message).

  // 4) A parse can end on an end-group tag.

  // This variable should always be set to 0, which indicates case 1. If the

  // parse terminated due to EOS (case 2), it's set to 1. In case the parse

  // ended due to a terminating tag (case 3 and 4) it's set to (tag - 1).

  // This var doesn't really belong in EpsCopyInputStream and should be part of

  // the ParseContext, but case 2 is most easily and optimally implemented in

  // DoneFallback.

  uint32_t last_tag_minus_1_ = 0;

  int overall_limit_ = INT_MAX;  // Overall limit independent of pushed limits.

  // Pretty random large number that seems like a safe allocation on most

  // systems. TODO(gerbens) do we need to set this as build flag?

  enum { kSafeStringSize = 50000000 };

  // Advances to next buffer chunk returns a pointer to the same logical place

  // in the stream as set by overrun. Overrun indicates the position in the slop

  // region the parse was left (0 <= overrun <= kSlopBytes). Returns true if at

  // limit, at which point the returned pointer maybe null if there was an

  // error. The invariant of this function is that it's guaranteed that

  // kSlopBytes bytes can be accessed from the returned ptr. This function might

  // advance more buffers than one in the underlying ZeroCopyInputStream.

  std::pair<const char*, bool> DoneFallback(int overrun, int depth);

  // Advances to the next buffer, at most one call to Next() on the underlying

  // ZeroCopyInputStream is made. This function DOES NOT match the returned

  // pointer to where in the slop region the parse ends, hence no overrun

  // parameter. This is useful for string operations where you always copy

  // to the end of the buffer (including the slop region).

  const char* Next();

  // overrun is the location in the slop region the stream currently is

  // (0 <= overrun <= kSlopBytes). To prevent flipping to the next buffer of

  // the ZeroCopyInputStream in the case the parse will end in the last

  // kSlopBytes of the current buffer. depth is the current depth of nested

  // groups (or negative if the use case does not need careful tracking).

  inline const char* NextBuffer(int overrun, int depth);

  const char* SkipFallback(const char* ptr, int size);

  const char* AppendStringFallback(const char* ptr, int size, std::string* str);

  const char* ReadStringFallback(const char* ptr, int size, std::string* str);

  bool StreamNext(const void** data) {

    bool res = zcis_->Next(data, &size_);

    if (res) overall_limit_ -= size_;

    return res;

  }

  void StreamBackUp(int count) {

    zcis_->BackUp(count);

    overall_limit_ += count;

  }

  template <typename A>

  const char* AppendSize(const char* ptr, int size, const A& append) {

    int chunk_size = buffer_end_ + kSlopBytes - ptr;

    do {

      GOOGLE_DCHECK(size > chunk_size);

      if (next_chunk_ == nullptr) return nullptr;

      append(ptr, chunk_size);

      ptr += chunk_size;

      size -= chunk_size;

      // TODO(gerbens) Next calls NextBuffer which generates buffers with

      // overlap and thus incurs cost of copying the slop regions. This is not

      // necessary for reading strings. We should just call Next buffers.

      if (limit_ <= kSlopBytes) return nullptr;

      ptr = Next();

      if (ptr == nullptr) return nullptr;  // passed the limit

      ptr += kSlopBytes;

      chunk_size = buffer_end_ + kSlopBytes - ptr;

    } while (size > chunk_size);

    append(ptr, size);

    return ptr + size;

  }

  // AppendUntilEnd appends data until a limit (either a PushLimit or end of

  // stream. Normal payloads are from length delimited fields which have an

  // explicit size. Reading until limit only comes when the string takes

  // the place of a protobuf, ie RawMessage/StringRawMessage, lazy fields and

  // implicit weak messages. We keep these methods private and friend them.

  template <typename A>

  const char* AppendUntilEnd(const char* ptr, const A& append) {

    if (ptr - buffer_end_ > limit_) return nullptr;

    while (limit_ > kSlopBytes) {

      size_t chunk_size = buffer_end_ + kSlopBytes - ptr;

      append(ptr, chunk_size);

      ptr = Next();

      if (ptr == nullptr) return limit_end_;

      ptr += kSlopBytes;

    }

    auto end = buffer_end_ + limit_;

    GOOGLE_DCHECK(end >= ptr);

    append(ptr, end - ptr);

    return end;

  }

  PROTOBUF_NODISCARD const char* AppendString(const char* ptr,

                                              std::string* str) {

    return AppendUntilEnd(

        ptr, [str](const char* p, ptrdiff_t s) { str->append(p, s); });

  }

  friend class ImplicitWeakMessage;

};

using LazyEagerVerifyFnType = const char* (*)(const char* ptr,

                                              ParseContext* ctx);

using LazyEagerVerifyFnRef = std::remove_pointer<LazyEagerVerifyFnType>::type&;

// ParseContext holds all data that is global to the entire parse. Most

// importantly it contains the input stream, but also recursion depth and also

// stores the end group tag, in case a parser ended on a endgroup, to verify

// matching start/end group tags.

class PROTOBUF_EXPORT ParseContext : public EpsCopyInputStream {

 public:

  struct Data {

    const DescriptorPool* pool = nullptr;

    MessageFactory* factory = nullptr;

    Arena* arena = nullptr;

  };

  template <typename... T>

  ParseContext(int depth, bool aliasing, const char** start, T&&... args)

      : EpsCopyInputStream(aliasing), depth_(depth) {

    *start = InitFrom(std::forward<T>(args)...);

  }

  void TrackCorrectEnding() { group_depth_ = 0; }

  bool Done(const char** ptr) { return DoneWithCheck(ptr, group_depth_); }

  int depth() const { return depth_; }

  Data& data() { return data_; }

  const Data& data() const { return data_; }

  const char* ParseMessage(MessageLite* msg, const char* ptr);

  // Spawns a child parsing context that inherits key properties. New context

  // inherits the following:

  // --depth_, data_, check_required_fields_, lazy_parse_mode_

  // The spawned context always disables aliasing (different input).

  template <typename... T>

  ParseContext Spawn(const char** start, T&&... args) {

    ParseContext spawned(depth_, false, start, std::forward<T>(args)...);

    // Transfer key context states.

    spawned.data_ = data_;

    return spawned;

  }

  // This overload supports those few cases where ParseMessage is called

  // on a class that is not actually a proto message.

  // TODO(jorg): Eliminate this use case.

  template <typename T,

            typename std::enable_if<!std::is_base_of<MessageLite, T>::value,

                                    bool>::type = true>

  PROTOBUF_NODISCARD const char* ParseMessage(T* msg, const char* ptr);

  template <typename T>

  PROTOBUF_NODISCARD PROTOBUF_NDEBUG_INLINE const char* ParseGroup(

      T* msg, const char* ptr, uint32_t tag) {

    if (--depth_ < 0) return nullptr;

    group_depth_++;

    ptr = msg->_InternalParse(ptr, this);

    group_depth_--;

    depth_++;

    if (PROTOBUF_PREDICT_FALSE(!ConsumeEndGroup(tag))) return nullptr;

    return ptr;

  }

 private:

  // Out-of-line routine to save space in ParseContext::ParseMessage<T>

  //   int old;

  //   ptr = ReadSizeAndPushLimitAndDepth(ptr, &old)

  // is equivalent to:

  //   int size = ReadSize(&ptr);

  //   if (!ptr) return nullptr;

  //   int old = PushLimit(ptr, size);

  //   if (--depth_ < 0) return nullptr;

  PROTOBUF_NODISCARD const char* ReadSizeAndPushLimitAndDepth(const char* ptr,

                                                              int* old_limit);

  // The context keeps an internal stack to keep track of the recursive

  // part of the parse state.

  // Current depth of the active parser, depth counts down.

  // This is used to limit recursion depth (to prevent overflow on malicious

  // data), but is also used to index in stack_ to store the current state.

  int depth_;

  // Unfortunately necessary for the fringe case of ending on 0 or end-group tag

  // in the last kSlopBytes of a ZeroCopyInputStream chunk.

  int group_depth_ = INT_MIN;

  Data data_;

};

template <uint32_t tag>

bool ExpectTag(const char* ptr) {

  if (tag < 128) {

    return *ptr == static_cast<char>(tag);

  } else {

    static_assert(tag < 128 * 128, "We only expect tags for 1 or 2 bytes");

    char buf[2] = {static_cast<char>(tag | 0x80), static_cast<char>(tag >> 7)};

    return std::memcmp(ptr, buf, 2) == 0;

  }

}

Unexecuted instantiation: bool google::protobuf::internal::ExpectTag<26u>(char const*)

Unexecuted instantiation: bool google::protobuf::internal::ExpectTag<10u>(char const*)

Unexecuted instantiation: bool google::protobuf::internal::ExpectTag<18u>(char const*)

Unexecuted instantiation: bool google::protobuf::internal::ExpectTag<34u>(char const*)

template <int>

struct EndianHelper;

template <>

struct EndianHelper<1> {

  static uint8_t Load(const void* p) { return *static_cast<const uint8_t*>(p); }

};

template <>

struct EndianHelper<2> {

  static uint16_t Load(const void* p) {

    uint16_t tmp;

    std::memcpy(&tmp, p, 2);

    return little_endian::ToHost(tmp);

  }

};

template <>

struct EndianHelper<4> {

  static uint32_t Load(const void* p) {

    uint32_t tmp;

    std::memcpy(&tmp, p, 4);

    return little_endian::ToHost(tmp);

  }

};

template <>

struct EndianHelper<8> {

  static uint64_t Load(const void* p) {

    uint64_t tmp;

    std::memcpy(&tmp, p, 8);

    return little_endian::ToHost(tmp);

  }

};

template <typename T>

T UnalignedLoad(const char* p) {

  auto tmp = EndianHelper<sizeof(T)>::Load(p);

  T res;

  memcpy(&res, &tmp, sizeof(T));

  return res;

}

Unexecuted instantiation: unsigned short google::protobuf::internal::UnalignedLoad<unsigned short>(char const*)

Unexecuted instantiation: float google::protobuf::internal::UnalignedLoad<float>(char const*)

Unexecuted instantiation: double google::protobuf::internal::UnalignedLoad<double>(char const*)

Unexecuted instantiation: unsigned long google::protobuf::internal::UnalignedLoad<unsigned long>(char const*)

Unexecuted instantiation: unsigned int google::protobuf::internal::UnalignedLoad<unsigned int>(char const*)

Unexecuted instantiation: long google::protobuf::internal::UnalignedLoad<long>(char const*)

Unexecuted instantiation: int google::protobuf::internal::UnalignedLoad<int>(char const*)

PROTOBUF_EXPORT

std::pair<const char*, uint32_t> VarintParseSlow32(const char* p, uint32_t res);

PROTOBUF_EXPORT

std::pair<const char*, uint64_t> VarintParseSlow64(const char* p, uint32_t res);

inline const char* VarintParseSlow(const char* p, uint32_t res, uint32_t* out) {

  auto tmp = VarintParseSlow32(p, res);

  *out = tmp.second;

  return tmp.first;

}

inline const char* VarintParseSlow(const char* p, uint32_t res, uint64_t* out) {

  auto tmp = VarintParseSlow64(p, res);

  *out = tmp.second;

  return tmp.first;

}

template <typename T>

PROTOBUF_NODISCARD const char* VarintParse(const char* p, T* out) {

  auto ptr = reinterpret_cast<const uint8_t*>(p);

  uint32_t res = ptr[0];

  if (!(res & 0x80)) {

    *out = res;

    return p + 1;

  }

  uint32_t byte = ptr[1];

  res += (byte - 1) << 7;

  if (!(byte & 0x80)) {

    *out = res;

    return p + 2;

  }

  return VarintParseSlow(p, res, out);

}

Unexecuted instantiation: char const* google::protobuf::internal::VarintParse<unsigned long>(char const*, unsigned long*)

Unexecuted instantiation: char const* google::protobuf::internal::VarintParse<unsigned int>(char const*, unsigned int*)

// Used for tags, could read up to 5 bytes which must be available.

// Caller must ensure its safe to call.

PROTOBUF_EXPORT

std::pair<const char*, uint32_t> ReadTagFallback(const char* p, uint32_t res);

// Same as ParseVarint but only accept 5 bytes at most.

inline const char* ReadTag(const char* p, uint32_t* out,

                           uint32_t /*max_tag*/ = 0) {

  uint32_t res = static_cast<uint8_t>(p[0]);

  if (res < 128) {

    *out = res;

    return p + 1;

  }

  uint32_t second = static_cast<uint8_t>(p[1]);

  res += (second - 1) << 7;

  if (second < 128) {

    *out = res;

    return p + 2;

  }

  auto tmp = ReadTagFallback(p, res);

  *out = tmp.second;

  return tmp.first;

}

// As above, but optimized to consume very few registers while still being fast,

// ReadTagInlined is useful for callers that don't mind the extra code but would

// like to avoid an extern function call causing spills into the stack.

//

// Two support routines for ReadTagInlined come first...

template <class T>

PROTOBUF_NODISCARD PROTOBUF_ALWAYS_INLINE constexpr T RotateLeft(

    T x, int s) noexcept {

  return static_cast<T>(x << (s & (std::numeric_limits<T>::digits - 1))) |

         static_cast<T>(x >> ((-s) & (std::numeric_limits<T>::digits - 1)));

}

PROTOBUF_NODISCARD inline PROTOBUF_ALWAYS_INLINE uint64_t

RotRight7AndReplaceLowByte(uint64_t res, const char& byte) {

#if defined(__x86_64__) && defined(__GNUC__)

  // This will only use one register for `res`.

  // `byte` comes as a reference to allow the compiler to generate code like:

  //

  //   rorq    $7, %rcx

  //   movb    1(%rax), %cl

  //

  // which avoids loading the incoming bytes into a separate register first.

  asm("ror $7,%0\n\t"

      "movb %1,%b0"

      : "+r"(res)

      : "m"(byte));

#else

  res = RotateLeft(res, -7);

  res = res & ~0xFF;

  res |= 0xFF & byte;

#endif

  return res;

};

inline PROTOBUF_ALWAYS_INLINE

const char* ReadTagInlined(const char* ptr, uint32_t* out) {

  uint64_t res = 0xFF & ptr[0];

  if (PROTOBUF_PREDICT_FALSE(res >= 128)) {

    res = RotRight7AndReplaceLowByte(res, ptr[1]);

    if (PROTOBUF_PREDICT_FALSE(res & 0x80)) {

      res = RotRight7AndReplaceLowByte(res, ptr[2]);

      if (PROTOBUF_PREDICT_FALSE(res & 0x80)) {

        res = RotRight7AndReplaceLowByte(res, ptr[3]);

        if (PROTOBUF_PREDICT_FALSE(res & 0x80)) {

          // Note: this wouldn't work if res were 32-bit,

          // because then replacing the low byte would overwrite

          // the bottom 4 bits of the result.

          res = RotRight7AndReplaceLowByte(res, ptr[4]);

          if (PROTOBUF_PREDICT_FALSE(res & 0x80)) {

            // The proto format does not permit longer than 5-byte encodings for

            // tags.

            *out = 0;

            return nullptr;

          }

          *out = static_cast<uint32_t>(RotateLeft(res, 28));

#if defined(__GNUC__)

          // Note: this asm statement prevents the compiler from

          // trying to share the "return ptr + constant" among all

          // branches.

          asm("" : "+r"(ptr));

#endif

          return ptr + 5;

        }

        *out = static_cast<uint32_t>(RotateLeft(res, 21));

        return ptr + 4;

      }

      *out = static_cast<uint32_t>(RotateLeft(res, 14));

      return ptr + 3;

    }

    *out = static_cast<uint32_t>(RotateLeft(res, 7));

    return ptr + 2;

  }

  *out = static_cast<uint32_t>(res);

  return ptr + 1;

}

// Decode 2 consecutive bytes of a varint and returns the value, shifted left

// by 1. It simultaneous updates *ptr to *ptr + 1 or *ptr + 2 depending if the

// first byte's continuation bit is set.

// If bit 15 of return value is set (equivalent to the continuation bits of both

// bytes being set) the varint continues, otherwise the parse is done. On x86

// movsx eax, dil

// and edi, eax

// add eax, edi

// adc [rsi], 1

inline uint32_t DecodeTwoBytes(const char** ptr) {

  uint32_t value = UnalignedLoad<uint16_t>(*ptr);

  // Sign extend the low byte continuation bit

  uint32_t x = static_cast<int8_t>(value);

  value &= x;  // Mask out the high byte iff no continuation

  // This add is an amazing operation, it cancels the low byte continuation bit

  // from y transferring it to the carry. Simultaneously it also shifts the 7

  // LSB left by one tightly against high byte varint bits. Hence value now

  // contains the unpacked value shifted left by 1.

  value += x;

  // Use the carry to update the ptr appropriately.

  *ptr += value < x ? 2 : 1;

  return value;

}

// More efficient varint parsing for big varints

inline const char* ParseBigVarint(const char* p, uint64_t* out) {

  auto pnew = p;

  auto tmp = DecodeTwoBytes(&pnew);

  uint64_t res = tmp >> 1;

  if (PROTOBUF_PREDICT_TRUE(static_cast<std::int16_t>(tmp) >= 0)) {

    *out = res;

    return pnew;

  }

  for (std::uint32_t i = 1; i < 5; i++) {

    pnew = p + 2 * i;

    tmp = DecodeTwoBytes(&pnew);

    res += (static_cast<std::uint64_t>(tmp) - 2) << (14 * i - 1);

    if (PROTOBUF_PREDICT_TRUE(static_cast<std::int16_t>(tmp) >= 0)) {

      *out = res;

      return pnew;

    }

  }

  return nullptr;

}

PROTOBUF_EXPORT

std::pair<const char*, int32_t> ReadSizeFallback(const char* p, uint32_t first);

// Used for tags, could read up to 5 bytes which must be available. Additionally

// it makes sure the unsigned value fits a int32_t, otherwise returns nullptr.

// Caller must ensure its safe to call.

inline uint32_t ReadSize(const char** pp) {

  auto p = *pp;

  uint32_t res = static_cast<uint8_t>(p[0]);

  if (res < 128) {

    *pp = p + 1;

    return res;

  }

  auto x = ReadSizeFallback(p, res);

  *pp = x.first;

  return x.second;

}

// Some convenience functions to simplify the generated parse loop code.

// Returning the value and updating the buffer pointer allows for nicer

// function composition. We rely on the compiler to inline this.

// Also in debug compiles having local scoped variables tend to generated

// stack frames that scale as O(num fields).

inline uint64_t ReadVarint64(const char** p) {

  uint64_t tmp;

  *p = VarintParse(*p, &tmp);

  return tmp;

}

inline uint32_t ReadVarint32(const char** p) {

  uint32_t tmp;

  *p = VarintParse(*p, &tmp);

  return tmp;

}

inline int64_t ReadVarintZigZag64(const char** p) {

  uint64_t tmp;

  *p = VarintParse(*p, &tmp);

  return WireFormatLite::ZigZagDecode64(tmp);

}

inline int32_t ReadVarintZigZag32(const char** p) {

  uint64_t tmp;

  *p = VarintParse(*p, &tmp);

  return WireFormatLite::ZigZagDecode32(static_cast<uint32_t>(tmp));

}

template <typename T, typename std::enable_if<

                          !std::is_base_of<MessageLite, T>::value, bool>::type>

PROTOBUF_NODISCARD const char* ParseContext::ParseMessage(T* msg,

                                                          const char* ptr) {

  int old;

  ptr = ReadSizeAndPushLimitAndDepth(ptr, &old);

  ptr = ptr ? msg->_InternalParse(ptr, this) : nullptr;

  depth_++;

  if (!PopLimit(old)) return nullptr;

  return ptr;

}

template <typename Tag, typename T>

const char* EpsCopyInputStream::ReadRepeatedFixed(const char* ptr,

                                                  Tag expected_tag,

                                                  RepeatedField<T>* out) {

  do {

    out->Add(UnalignedLoad<T>(ptr));

    ptr += sizeof(T);

    if (PROTOBUF_PREDICT_FALSE(ptr >= limit_end_)) return ptr;

  } while (UnalignedLoad<Tag>(ptr) == expected_tag && (ptr += sizeof(Tag)));

  return ptr;

}

// Add any of the following lines to debug which parse function is failing.

#define GOOGLE_PROTOBUF_ASSERT_RETURN(predicate, ret) \

  if (!(predicate)) {                                  \

    /*  ::raise(SIGINT);  */                           \

    /*  GOOGLE_LOG(ERROR) << "Parse failure";  */             \

    return ret;                                        \

  }

#define GOOGLE_PROTOBUF_PARSER_ASSERT(predicate) \

  GOOGLE_PROTOBUF_ASSERT_RETURN(predicate, nullptr)

template <typename T>

const char* EpsCopyInputStream::ReadPackedFixed(const char* ptr, int size,

                                                RepeatedField<T>* out) {

  GOOGLE_PROTOBUF_PARSER_ASSERT(ptr);

  int nbytes = buffer_end_ + kSlopBytes - ptr;

  while (size > nbytes) {

    int num = nbytes / sizeof(T);

    int old_entries = out->size();

    out->Reserve(old_entries + num);

    int block_size = num * sizeof(T);

    auto dst = out->AddNAlreadyReserved(num);

#ifdef PROTOBUF_LITTLE_ENDIAN

    std::memcpy(dst, ptr, block_size);

#else

    for (int i = 0; i < num; i++)

      dst[i] = UnalignedLoad<T>(ptr + i * sizeof(T));

#endif

    size -= block_size;

    if (limit_ <= kSlopBytes) return nullptr;

    ptr = Next();

    if (ptr == nullptr) return nullptr;

    ptr += kSlopBytes - (nbytes - block_size);

    nbytes = buffer_end_ + kSlopBytes - ptr;

  }

  int num = size / sizeof(T);

  int old_entries = out->size();

  out->Reserve(old_entries + num);

  int block_size = num * sizeof(T);

  auto dst = out->AddNAlreadyReserved(num);

#ifdef PROTOBUF_LITTLE_ENDIAN

  std::memcpy(dst, ptr, block_size);

#else

  for (int i = 0; i < num; i++) dst[i] = UnalignedLoad<T>(ptr + i * sizeof(T));

#endif

  ptr += block_size;

  if (size != block_size) return nullptr;

  return ptr;

}

template <typename Add>

const char* ReadPackedVarintArray(const char* ptr, const char* end, Add add) {

  while (ptr < end) {

    uint64_t varint;

    ptr = VarintParse(ptr, &varint);

    if (ptr == nullptr) return nullptr;

    add(varint);

  }

  return ptr;

}

template <typename Add>

const char* EpsCopyInputStream::ReadPackedVarint(const char* ptr, Add add) {

  int size = ReadSize(&ptr);

  GOOGLE_PROTOBUF_PARSER_ASSERT(ptr);

  int chunk_size = buffer_end_ - ptr;

  while (size > chunk_size) {

    ptr = ReadPackedVarintArray(ptr, buffer_end_, add);

    if (ptr == nullptr) return nullptr;

    int overrun = ptr - buffer_end_;

    GOOGLE_DCHECK(overrun >= 0 && overrun <= kSlopBytes);

    if (size - chunk_size <= kSlopBytes) {

      // The current buffer contains all the information needed, we don't need

      // to flip buffers. However we must parse from a buffer with enough space

      // so we are not prone to a buffer overflow.

      char buf[kSlopBytes + 10] = {};

      std::memcpy(buf, buffer_end_, kSlopBytes);

      GOOGLE_CHECK_LE(size - chunk_size, kSlopBytes);

      auto end = buf + (size - chunk_size);

      auto res = ReadPackedVarintArray(buf + overrun, end, add);

      if (res == nullptr || res != end) return nullptr;

      return buffer_end_ + (res - buf);

    }

    size -= overrun + chunk_size;

    GOOGLE_DCHECK_GT(size, 0);

    // We must flip buffers

    if (limit_ <= kSlopBytes) return nullptr;

    ptr = Next();

    if (ptr == nullptr) return nullptr;

    ptr += overrun;

    chunk_size = buffer_end_ - ptr;

  }

  auto end = ptr + size;

  ptr = ReadPackedVarintArray(ptr, end, add);

  return end == ptr ? ptr : nullptr;

}

// Helper for verification of utf8

PROTOBUF_EXPORT

bool VerifyUTF8(StringPiece s, const char* field_name);

inline bool VerifyUTF8(const std::string* s, const char* field_name) {

  return VerifyUTF8(*s, field_name);

}

// All the string parsers with or without UTF checking and for all CTypes.

PROTOBUF_NODISCARD PROTOBUF_EXPORT const char* InlineGreedyStringParser(

    std::string* s, const char* ptr, ParseContext* ctx);

template <typename T>

PROTOBUF_NODISCARD const char* FieldParser(uint64_t tag, T& field_parser,

                                           const char* ptr, ParseContext* ctx) {

  uint32_t number = tag >> 3;

  GOOGLE_PROTOBUF_PARSER_ASSERT(number != 0);

  using WireType = internal::WireFormatLite::WireType;

  switch (tag & 7) {

    case WireType::WIRETYPE_VARINT: {

      uint64_t value;

      ptr = VarintParse(ptr, &value);

      GOOGLE_PROTOBUF_PARSER_ASSERT(ptr);

      field_parser.AddVarint(number, value);

      break;

    }

    case WireType::WIRETYPE_FIXED64: {

      uint64_t value = UnalignedLoad<uint64_t>(ptr);

      ptr += 8;

      field_parser.AddFixed64(number, value);

      break;

    }

    case WireType::WIRETYPE_LENGTH_DELIMITED: {

      ptr = field_parser.ParseLengthDelimited(number, ptr, ctx);

      GOOGLE_PROTOBUF_PARSER_ASSERT(ptr);

      break;

    }

    case WireType::WIRETYPE_START_GROUP: {

      ptr = field_parser.ParseGroup(number, ptr, ctx);

      GOOGLE_PROTOBUF_PARSER_ASSERT(ptr);

      break;

    }

    case WireType::WIRETYPE_END_GROUP: {

      GOOGLE_LOG(FATAL) << "Can't happen";

      break;

    }

    case WireType::WIRETYPE_FIXED32: {

      uint32_t value = UnalignedLoad<uint32_t>(ptr);

      ptr += 4;

      field_parser.AddFixed32(number, value);

      break;

    }

    default:

      return nullptr;

  }

  return ptr;

}

template <typename T>

PROTOBUF_NODISCARD const char* WireFormatParser(T& field_parser,

                                                const char* ptr,

                                                ParseContext* ctx) {

  while (!ctx->Done(&ptr)) {

    uint32_t tag;

    ptr = ReadTag(ptr, &tag);

    GOOGLE_PROTOBUF_PARSER_ASSERT(ptr != nullptr);

    if (tag == 0 || (tag & 7) == 4) {

      ctx->SetLastTag(tag);

      return ptr;

    }

    ptr = FieldParser(tag, field_parser, ptr, ctx);

    GOOGLE_PROTOBUF_PARSER_ASSERT(ptr != nullptr);

  }

  return ptr;

}

// The packed parsers parse repeated numeric primitives directly into  the

// corresponding field

// These are packed varints

PROTOBUF_NODISCARD PROTOBUF_EXPORT const char* PackedInt32Parser(

    void* object, const char* ptr, ParseContext* ctx);

PROTOBUF_NODISCARD PROTOBUF_EXPORT const char* PackedUInt32Parser(

    void* object, const char* ptr, ParseContext* ctx);

PROTOBUF_NODISCARD PROTOBUF_EXPORT const char* PackedInt64Parser(

    void* object, const char* ptr, ParseContext* ctx);

PROTOBUF_NODISCARD PROTOBUF_EXPORT const char* PackedUInt64Parser(

    void* object, const char* ptr, ParseContext* ctx);

PROTOBUF_NODISCARD PROTOBUF_EXPORT const char* PackedSInt32Parser(

    void* object, const char* ptr, ParseContext* ctx);

PROTOBUF_NODISCARD PROTOBUF_EXPORT const char* PackedSInt64Parser(

    void* object, const char* ptr, ParseContext* ctx);

PROTOBUF_NODISCARD PROTOBUF_EXPORT const char* PackedEnumParser(

    void* object, const char* ptr, ParseContext* ctx);

template <typename T>

PROTOBUF_NODISCARD const char* PackedEnumParser(void* object, const char* ptr,

                                                ParseContext* ctx,

                                                bool (*is_valid)(int),

                                                InternalMetadata* metadata,

                                                int field_num) {

  return ctx->ReadPackedVarint(

      ptr, [object, is_valid, metadata, field_num](uint64_t val) {

        if (is_valid(val)) {

          static_cast<RepeatedField<int>*>(object)->Add(val);

        } else {

          WriteVarint(field_num, val, metadata->mutable_unknown_fields<T>());

        }

      });

}

template <typename T>

PROTOBUF_NODISCARD const char* PackedEnumParserArg(

    void* object, const char* ptr, ParseContext* ctx,

    bool (*is_valid)(const void*, int), const void* data,

    InternalMetadata* metadata, int field_num) {

  return ctx->ReadPackedVarint(

      ptr, [object, is_valid, data, metadata, field_num](uint64_t val) {

        if (is_valid(data, val)) {

          static_cast<RepeatedField<int>*>(object)->Add(val);

        } else {

          WriteVarint(field_num, val, metadata->mutable_unknown_fields<T>());

        }

      });

}

PROTOBUF_NODISCARD PROTOBUF_EXPORT const char* PackedBoolParser(

    void* object, const char* ptr, ParseContext* ctx);

PROTOBUF_NODISCARD PROTOBUF_EXPORT const char* PackedFixed32Parser(

    void* object, const char* ptr, ParseContext* ctx);

PROTOBUF_NODISCARD PROTOBUF_EXPORT const char* PackedSFixed32Parser(

    void* object, const char* ptr, ParseContext* ctx);

PROTOBUF_NODISCARD PROTOBUF_EXPORT const char* PackedFixed64Parser(

    void* object, const char* ptr, ParseContext* ctx);

PROTOBUF_NODISCARD PROTOBUF_EXPORT const char* PackedSFixed64Parser(

    void* object, const char* ptr, ParseContext* ctx);

PROTOBUF_NODISCARD PROTOBUF_EXPORT const char* PackedFloatParser(

    void* object, const char* ptr, ParseContext* ctx);

PROTOBUF_NODISCARD PROTOBUF_EXPORT const char* PackedDoubleParser(

    void* object, const char* ptr, ParseContext* ctx);

// This is the only recursive parser.

PROTOBUF_NODISCARD PROTOBUF_EXPORT const char* UnknownGroupLiteParse(

    std::string* unknown, const char* ptr, ParseContext* ctx);

// This is a helper to for the UnknownGroupLiteParse but is actually also

// useful in the generated code. It uses overload on std::string* vs

// UnknownFieldSet* to make the generated code isomorphic between full and lite.

PROTOBUF_NODISCARD PROTOBUF_EXPORT const char* UnknownFieldParse(

    uint32_t tag, std::string* unknown, const char* ptr, ParseContext* ctx);

}  // namespace internal

}  // namespace protobuf

}  // namespace google

#include <google/protobuf/port_undef.inc>

#endif  // GOOGLE_PROTOBUF_PARSE_CONTEXT_H__