Files
clang-p2996/lldb/source/Utility/StringExtractor.cpp
Francis Ricci 15a2165d64 Skip leading spaces when decoding hex values
Summary:
The StringExtractor functions using stroull will already
skip leading whitespace (ie GetU64). Make sure that the manual
hex parsing functions also skip leading whitespace.

This is important for members of the gdb protocol which are defined
as using whitespace separators (ie qfThreadInfo, qC, etc). While
lldb-server does not use the whitespace separators, gdb-remotes
should work if they do, as the whitespace is defined by the gdb-remote
protocol.

Reviewers: vharron, jasonmolenda, clayborg

Subscribers: sas, lldb-commits

Differential Revision: http://reviews.llvm.org/D20509

llvm-svn: 270592
2016-05-24 18:19:45 +00:00

502 lines
13 KiB
C++

//===-- StringExtractor.cpp -------------------------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "lldb/Utility/StringExtractor.h"
// C Includes
#include <stdlib.h>
// C++ Includes
// Other libraries and framework includes
// Project includes
static inline int
xdigit_to_sint (char ch)
{
if (ch >= 'a' && ch <= 'f')
return 10 + ch - 'a';
if (ch >= 'A' && ch <= 'F')
return 10 + ch - 'A';
if (ch >= '0' && ch <= '9')
return ch - '0';
return -1;
}
//----------------------------------------------------------------------
// StringExtractor constructor
//----------------------------------------------------------------------
StringExtractor::StringExtractor() :
m_packet(),
m_index (0)
{
}
StringExtractor::StringExtractor(const char *packet_cstr) :
m_packet(),
m_index (0)
{
if (packet_cstr)
m_packet.assign (packet_cstr);
}
//----------------------------------------------------------------------
// StringExtractor copy constructor
//----------------------------------------------------------------------
StringExtractor::StringExtractor(const StringExtractor& rhs) :
m_packet (rhs.m_packet),
m_index (rhs.m_index)
{
}
//----------------------------------------------------------------------
// StringExtractor assignment operator
//----------------------------------------------------------------------
const StringExtractor&
StringExtractor::operator=(const StringExtractor& rhs)
{
if (this != &rhs)
{
m_packet = rhs.m_packet;
m_index = rhs.m_index;
}
return *this;
}
//----------------------------------------------------------------------
// Destructor
//----------------------------------------------------------------------
StringExtractor::~StringExtractor()
{
}
char
StringExtractor::GetChar (char fail_value)
{
if (m_index < m_packet.size())
{
char ch = m_packet[m_index];
++m_index;
return ch;
}
m_index = UINT64_MAX;
return fail_value;
}
//----------------------------------------------------------------------
// If a pair of valid hex digits exist at the head of the
// StringExtractor they are decoded into an unsigned byte and returned
// by this function
//
// If there is not a pair of valid hex digits at the head of the
// StringExtractor, it is left unchanged and -1 is returned
//----------------------------------------------------------------------
int
StringExtractor::DecodeHexU8()
{
SkipSpaces();
if (GetBytesLeft() < 2)
{
return -1;
}
const int hi_nibble = xdigit_to_sint(m_packet[m_index]);
const int lo_nibble = xdigit_to_sint(m_packet[m_index+1]);
if (hi_nibble == -1 || lo_nibble == -1)
{
return -1;
}
m_index += 2;
return (uint8_t)((hi_nibble << 4) + lo_nibble);
}
//----------------------------------------------------------------------
// Extract an unsigned character from two hex ASCII chars in the packet
// string, or return fail_value on failure
//----------------------------------------------------------------------
uint8_t
StringExtractor::GetHexU8 (uint8_t fail_value, bool set_eof_on_fail)
{
// On success, fail_value will be overwritten with the next
// character in the stream
GetHexU8Ex(fail_value, set_eof_on_fail);
return fail_value;
}
bool
StringExtractor::GetHexU8Ex (uint8_t& ch, bool set_eof_on_fail)
{
int byte = DecodeHexU8();
if (byte == -1)
{
if (set_eof_on_fail || m_index >= m_packet.size())
m_index = UINT64_MAX;
// ch should not be changed in case of failure
return false;
}
ch = (uint8_t)byte;
return true;
}
uint32_t
StringExtractor::GetU32 (uint32_t fail_value, int base)
{
if (m_index < m_packet.size())
{
char *end = nullptr;
const char *start = m_packet.c_str();
const char *cstr = start + m_index;
uint32_t result = static_cast<uint32_t>(::strtoul (cstr, &end, base));
if (end && end != cstr)
{
m_index = end - start;
return result;
}
}
return fail_value;
}
int32_t
StringExtractor::GetS32 (int32_t fail_value, int base)
{
if (m_index < m_packet.size())
{
char *end = nullptr;
const char *start = m_packet.c_str();
const char *cstr = start + m_index;
int32_t result = static_cast<int32_t>(::strtol (cstr, &end, base));
if (end && end != cstr)
{
m_index = end - start;
return result;
}
}
return fail_value;
}
uint64_t
StringExtractor::GetU64 (uint64_t fail_value, int base)
{
if (m_index < m_packet.size())
{
char *end = nullptr;
const char *start = m_packet.c_str();
const char *cstr = start + m_index;
uint64_t result = ::strtoull (cstr, &end, base);
if (end && end != cstr)
{
m_index = end - start;
return result;
}
}
return fail_value;
}
int64_t
StringExtractor::GetS64 (int64_t fail_value, int base)
{
if (m_index < m_packet.size())
{
char *end = nullptr;
const char *start = m_packet.c_str();
const char *cstr = start + m_index;
int64_t result = ::strtoll (cstr, &end, base);
if (end && end != cstr)
{
m_index = end - start;
return result;
}
}
return fail_value;
}
uint32_t
StringExtractor::GetHexMaxU32 (bool little_endian, uint32_t fail_value)
{
uint32_t result = 0;
uint32_t nibble_count = 0;
SkipSpaces();
if (little_endian)
{
uint32_t shift_amount = 0;
while (m_index < m_packet.size() && ::isxdigit (m_packet[m_index]))
{
// Make sure we don't exceed the size of a uint32_t...
if (nibble_count >= (sizeof(uint32_t) * 2))
{
m_index = UINT64_MAX;
return fail_value;
}
uint8_t nibble_lo;
uint8_t nibble_hi = xdigit_to_sint (m_packet[m_index]);
++m_index;
if (m_index < m_packet.size() && ::isxdigit (m_packet[m_index]))
{
nibble_lo = xdigit_to_sint (m_packet[m_index]);
++m_index;
result |= ((uint32_t)nibble_hi << (shift_amount + 4));
result |= ((uint32_t)nibble_lo << shift_amount);
nibble_count += 2;
shift_amount += 8;
}
else
{
result |= ((uint32_t)nibble_hi << shift_amount);
nibble_count += 1;
shift_amount += 4;
}
}
}
else
{
while (m_index < m_packet.size() && ::isxdigit (m_packet[m_index]))
{
// Make sure we don't exceed the size of a uint32_t...
if (nibble_count >= (sizeof(uint32_t) * 2))
{
m_index = UINT64_MAX;
return fail_value;
}
uint8_t nibble = xdigit_to_sint (m_packet[m_index]);
// Big Endian
result <<= 4;
result |= nibble;
++m_index;
++nibble_count;
}
}
return result;
}
uint64_t
StringExtractor::GetHexMaxU64 (bool little_endian, uint64_t fail_value)
{
uint64_t result = 0;
uint32_t nibble_count = 0;
SkipSpaces();
if (little_endian)
{
uint32_t shift_amount = 0;
while (m_index < m_packet.size() && ::isxdigit (m_packet[m_index]))
{
// Make sure we don't exceed the size of a uint64_t...
if (nibble_count >= (sizeof(uint64_t) * 2))
{
m_index = UINT64_MAX;
return fail_value;
}
uint8_t nibble_lo;
uint8_t nibble_hi = xdigit_to_sint (m_packet[m_index]);
++m_index;
if (m_index < m_packet.size() && ::isxdigit (m_packet[m_index]))
{
nibble_lo = xdigit_to_sint (m_packet[m_index]);
++m_index;
result |= ((uint64_t)nibble_hi << (shift_amount + 4));
result |= ((uint64_t)nibble_lo << shift_amount);
nibble_count += 2;
shift_amount += 8;
}
else
{
result |= ((uint64_t)nibble_hi << shift_amount);
nibble_count += 1;
shift_amount += 4;
}
}
}
else
{
while (m_index < m_packet.size() && ::isxdigit (m_packet[m_index]))
{
// Make sure we don't exceed the size of a uint64_t...
if (nibble_count >= (sizeof(uint64_t) * 2))
{
m_index = UINT64_MAX;
return fail_value;
}
uint8_t nibble = xdigit_to_sint (m_packet[m_index]);
// Big Endian
result <<= 4;
result |= nibble;
++m_index;
++nibble_count;
}
}
return result;
}
size_t
StringExtractor::GetHexBytes (void *dst_void, size_t dst_len, uint8_t fail_fill_value)
{
uint8_t *dst = (uint8_t*)dst_void;
size_t bytes_extracted = 0;
while (bytes_extracted < dst_len && GetBytesLeft ())
{
dst[bytes_extracted] = GetHexU8 (fail_fill_value);
if (IsGood())
++bytes_extracted;
else
break;
}
for (size_t i = bytes_extracted; i < dst_len; ++i)
dst[i] = fail_fill_value;
return bytes_extracted;
}
//----------------------------------------------------------------------
// Decodes all valid hex encoded bytes at the head of the
// StringExtractor, limited by dst_len.
//
// Returns the number of bytes successfully decoded
//----------------------------------------------------------------------
size_t
StringExtractor::GetHexBytesAvail (void *dst_void, size_t dst_len)
{
uint8_t *dst = (uint8_t*)dst_void;
size_t bytes_extracted = 0;
while (bytes_extracted < dst_len)
{
int decode = DecodeHexU8();
if (decode == -1)
{
break;
}
dst[bytes_extracted++] = (uint8_t)decode;
}
return bytes_extracted;
}
// Consume ASCII hex nibble character pairs until we have decoded byte_size
// bytes of data.
uint64_t
StringExtractor::GetHexWithFixedSize (uint32_t byte_size, bool little_endian, uint64_t fail_value)
{
if (byte_size <= 8 && GetBytesLeft() >= byte_size * 2)
{
uint64_t result = 0;
uint32_t i;
if (little_endian)
{
// Little Endian
uint32_t shift_amount;
for (i = 0, shift_amount = 0;
i < byte_size && IsGood();
++i, shift_amount += 8)
{
result |= ((uint64_t)GetHexU8() << shift_amount);
}
}
else
{
// Big Endian
for (i = 0; i < byte_size && IsGood(); ++i)
{
result <<= 8;
result |= GetHexU8();
}
}
}
m_index = UINT64_MAX;
return fail_value;
}
size_t
StringExtractor::GetHexByteString (std::string &str)
{
str.clear();
char ch;
while ((ch = GetHexU8()) != '\0')
str.append(1, ch);
return str.size();
}
size_t
StringExtractor::GetHexByteStringFixedLength (std::string &str, uint32_t nibble_length)
{
str.clear();
uint32_t nibble_count = 0;
for (const char *pch = Peek(); (nibble_count < nibble_length) && (pch != nullptr); str.append(1, GetHexU8(0, false)), pch = Peek (), nibble_count += 2)
{}
return str.size();
}
size_t
StringExtractor::GetHexByteStringTerminatedBy (std::string &str,
char terminator)
{
str.clear();
char ch;
while ((ch = GetHexU8(0,false)) != '\0')
str.append(1, ch);
if (Peek() && *Peek() == terminator)
return str.size();
str.clear();
return str.size();
}
bool
StringExtractor::GetNameColonValue (std::string &name, std::string &value)
{
// Read something in the form of NNNN:VVVV; where NNNN is any character
// that is not a colon, followed by a ':' character, then a value (one or
// more ';' chars), followed by a ';'
if (m_index < m_packet.size())
{
const size_t colon_idx = m_packet.find (':', m_index);
if (colon_idx != std::string::npos)
{
const size_t semicolon_idx = m_packet.find (';', colon_idx);
if (semicolon_idx != std::string::npos)
{
name.assign (m_packet, m_index, colon_idx - m_index);
value.assign (m_packet, colon_idx + 1, semicolon_idx - (colon_idx + 1));
m_index = semicolon_idx + 1;
return true;
}
}
}
m_index = UINT64_MAX;
return false;
}
void
StringExtractor::SkipSpaces ()
{
const size_t n = m_packet.size();
while (m_index < n && isspace(m_packet[m_index]))
++m_index;
}