ladybird/AK/BufferStream.h
Itamar 8a886e0e96 LibDebug: Parse line number information from DWARF format
DWARF line number information, if generated, is stored  in the
.debug_line section of an object file.

The information is encoded as instructions for a VM that is defined in
the DWARF specification.
By executing these instructions, we can extract the encoded line number
information.
2020-04-20 17:25:50 +02:00

449 lines
12 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. 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.
*
* 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 HOLDER 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.
*/
#pragma once
#include <AK/ByteBuffer.h>
#include <AK/String.h>
#include <AK/StringView.h>
namespace AK {
class BufferStream {
public:
explicit BufferStream(ByteBuffer& buffer)
: m_buffer(buffer)
{
}
~BufferStream()
{
ASSERT(!m_read_failure);
}
BufferStream& operator<<(i8 value)
{
m_buffer[m_offset++] = value;
return *this;
}
BufferStream& operator>>(i8& value)
{
if (m_offset + sizeof(value) > unsigned(m_buffer.size())) {
m_read_failure = true;
return *this;
}
value = m_buffer[m_offset++];
return *this;
}
BufferStream& operator<<(u8 value)
{
m_buffer[m_offset++] = value;
return *this;
}
BufferStream& operator>>(u8& value)
{
if (m_offset + sizeof(value) > unsigned(m_buffer.size())) {
m_read_failure = true;
return *this;
}
value = m_buffer[m_offset++];
return *this;
}
BufferStream& operator<<(bool value)
{
m_buffer[m_offset++] = value;
return *this;
}
BufferStream& operator>>(bool& value)
{
if (m_offset + sizeof(value) > unsigned(m_buffer.size())) {
m_read_failure = true;
return *this;
}
value = m_buffer[m_offset++];
return *this;
}
BufferStream& operator<<(float value)
{
union bits {
float as_float;
u32 as_u32;
} u;
u.as_float = value;
return *this << u.as_u32;
}
BufferStream& operator>>(float& value)
{
union bits {
float as_float;
u32 as_u32;
} u;
*this >> u.as_u32;
if (m_read_failure)
return *this;
value = u.as_float;
return *this;
}
BufferStream& operator<<(char value)
{
m_buffer[m_offset++] = (u8)value;
return *this;
}
BufferStream& operator>>(char& value)
{
if (m_offset + sizeof(value) > unsigned(m_buffer.size())) {
m_read_failure = true;
return *this;
}
value = (u8)m_buffer[m_offset++];
return *this;
}
BufferStream& operator<<(u16 value)
{
m_buffer[m_offset++] = value;
m_buffer[m_offset++] = (u8)(value >> 8);
return *this;
}
BufferStream& operator>>(u16& value)
{
if (m_offset + sizeof(value) > unsigned(m_buffer.size())) {
m_read_failure = true;
return *this;
}
value = 0;
u8 b0 = m_buffer[m_offset++];
u8 b1 = m_buffer[m_offset++];
value |= (u8(b1) << 8);
value |= (u8(b0));
return *this;
}
BufferStream& operator<<(i16 value)
{
m_buffer[m_offset++] = value;
m_buffer[m_offset++] = (u8)(value >> 8);
return *this;
}
BufferStream& operator>>(i16& value)
{
if (m_offset + sizeof(value) > unsigned(m_buffer.size())) {
m_read_failure = true;
return *this;
}
value = 0;
u8 b0 = m_buffer[m_offset++];
u8 b1 = m_buffer[m_offset++];
value |= (u8(b1) << 8);
value |= (u8(b0));
return *this;
}
BufferStream& operator<<(u32 value)
{
m_buffer[m_offset++] = value;
m_buffer[m_offset++] = (u8)(value >> 8);
m_buffer[m_offset++] = (u8)(value >> 16);
m_buffer[m_offset++] = (u8)(value >> 24);
return *this;
}
BufferStream& operator>>(u32& value)
{
if (m_offset + sizeof(value) > unsigned(m_buffer.size())) {
m_read_failure = true;
return *this;
}
u8 b0 = m_buffer[m_offset++];
u8 b1 = m_buffer[m_offset++];
u8 b2 = m_buffer[m_offset++];
u8 b3 = m_buffer[m_offset++];
value = 0;
value |= (u8(b3) << 24);
value |= (u8(b2) << 16);
value |= (u8(b1) << 8);
value |= (u8(b0));
return *this;
}
BufferStream& operator<<(i32 value)
{
m_buffer[m_offset++] = value;
m_buffer[m_offset++] = (u8)(value >> 8);
m_buffer[m_offset++] = (u8)(value >> 16);
m_buffer[m_offset++] = (u8)(value >> 24);
return *this;
}
BufferStream& operator>>(i32& value)
{
if (m_offset + sizeof(value) > unsigned(m_buffer.size())) {
m_read_failure = true;
return *this;
}
u8 b0 = m_buffer[m_offset++];
u8 b1 = m_buffer[m_offset++];
u8 b2 = m_buffer[m_offset++];
u8 b3 = m_buffer[m_offset++];
value = 0;
value |= (u8(b3) << 24);
value |= (u8(b2) << 16);
value |= (u8(b1) << 8);
value |= (u8(b0));
return *this;
}
BufferStream& operator<<(u64 value)
{
m_buffer[m_offset++] = value;
m_buffer[m_offset++] = (u8)(value >> 8);
m_buffer[m_offset++] = (u8)(value >> 16);
m_buffer[m_offset++] = (u8)(value >> 24);
m_buffer[m_offset++] = (u8)(value >> 32);
m_buffer[m_offset++] = (u8)(value >> 40);
m_buffer[m_offset++] = (u8)(value >> 48);
m_buffer[m_offset++] = (u8)(value >> 56);
return *this;
}
BufferStream& operator>>(u64& value)
{
if (m_offset + sizeof(value) > unsigned(m_buffer.size())) {
m_read_failure = true;
return *this;
}
u8 b0 = m_buffer[m_offset++];
u8 b1 = m_buffer[m_offset++];
u8 b2 = m_buffer[m_offset++];
u8 b3 = m_buffer[m_offset++];
u8 b4 = m_buffer[m_offset++];
u8 b5 = m_buffer[m_offset++];
u8 b6 = m_buffer[m_offset++];
u8 b7 = m_buffer[m_offset++];
value = 0;
value |= ((long long)b7 << 56);
value |= ((long long)b6 << 48);
value |= ((long long)b5 << 40);
value |= ((long long)b4 << 32);
value |= ((long long)b3 << 24);
value |= ((long long)b2 << 16);
value |= ((long long)b1 << 8);
value |= ((long long)b0);
return *this;
}
BufferStream& operator<<(i64 value)
{
m_buffer[m_offset++] = value;
m_buffer[m_offset++] = (u8)(value >> 8);
m_buffer[m_offset++] = (u8)(value >> 16);
m_buffer[m_offset++] = (u8)(value >> 24);
m_buffer[m_offset++] = (u8)(value >> 32);
m_buffer[m_offset++] = (u8)(value >> 40);
m_buffer[m_offset++] = (u8)(value >> 48);
m_buffer[m_offset++] = (u8)(value >> 56);
return *this;
}
BufferStream& operator>>(i64& value)
{
if (m_offset + sizeof(value) > unsigned(m_buffer.size())) {
m_read_failure = true;
return *this;
}
u8 b0 = m_buffer[m_offset++];
u8 b1 = m_buffer[m_offset++];
u8 b2 = m_buffer[m_offset++];
u8 b3 = m_buffer[m_offset++];
u8 b4 = m_buffer[m_offset++];
u8 b5 = m_buffer[m_offset++];
u8 b6 = m_buffer[m_offset++];
u8 b7 = m_buffer[m_offset++];
value = 0;
value |= ((long long)b7 << 56);
value |= ((long long)b6 << 48);
value |= ((long long)b5 << 40);
value |= ((long long)b4 << 32);
value |= ((long long)b3 << 24);
value |= ((long long)b2 << 16);
value |= ((long long)b1 << 8);
value |= ((long long)b0);
return *this;
}
BufferStream& operator<<(const char* value)
{
return *this << StringView(value);
}
BufferStream& operator<<(const StringView& value)
{
for (size_t i = 0; i < value.length(); ++i)
m_buffer[m_offset++] = value[i];
return *this;
}
BufferStream& operator<<(const ByteBuffer& value)
{
for (size_t i = 0; i < value.size(); ++i)
m_buffer[m_offset++] = value[i];
return *this;
}
BufferStream& read_raw(u8* raw_data, size_t size)
{
if (m_offset + size > m_buffer.size()) {
m_read_failure = true;
return *this;
}
__builtin_memcpy(raw_data, m_buffer.data() + m_offset, size);
m_offset += size;
return *this;
};
u8 peek()
{
if (m_offset >= m_buffer.size()) {
m_read_failure = true;
return 0;
}
return m_buffer[m_offset];
}
BufferStream& operator>>(String& str)
{
if (m_offset >= m_buffer.size()) {
m_read_failure = true;
return *this;
}
size_t string_size = 0;
while (m_offset + string_size < m_buffer.size() && m_buffer[m_offset + string_size]) {
++string_size;
}
str = String(reinterpret_cast<const char*>(&m_buffer[m_offset]), string_size);
m_offset += string_size + 1;
return *this;
}
// LEB128 is a variable-length encoding for integers
BufferStream& read_LEB128_unsigned(size_t& result)
{
result = 0;
size_t num_bytes = 0;
while (true) {
if (m_offset > m_buffer.size()) {
m_read_failure = true;
break;
}
const u8 byte = m_buffer[m_offset];
result = (result) | (static_cast<size_t>(byte & ~(1 << 7)) << (num_bytes * 7));
++m_offset;
if (!(byte & (1 << 7)))
break;
++num_bytes;
}
return *this;
}
// LEB128 is a variable-length encoding for integers
BufferStream& read_LEB128_signed(ssize_t& result)
{
result = 0;
size_t num_bytes = 0;
u8 byte = 0;
do {
if (m_offset > m_buffer.size()) {
m_read_failure = true;
break;
}
byte = m_buffer[m_offset];
result = (result) | (static_cast<size_t>(byte & ~(1 << 7)) << (num_bytes * 7));
++m_offset;
++num_bytes;
} while (byte & (1 << 7));
if (num_bytes * 7 < sizeof(size_t) * 4 && (byte & 0x40)) {
// sign extend
result |= ((size_t)(-1) << (num_bytes * 7));
}
return *this;
}
BufferStream& advance(size_t amount)
{
if (m_offset + amount > m_buffer.size()) {
m_read_failure = true;
} else {
m_offset += amount;
}
return *this;
}
bool at_end() const
{
return m_offset == m_buffer.size();
}
void fill_to_end(u8 ch)
{
while (!at_end())
m_buffer[m_offset++] = ch;
}
ssize_t offset() const { return m_offset; }
void snip()
{
m_buffer.trim(m_offset);
}
void reset()
{
m_offset = 0;
m_read_failure = false;
}
bool handle_read_failure()
{
bool old = m_read_failure;
m_read_failure = false;
return old;
}
private:
ByteBuffer& m_buffer;
size_t m_offset { 0 };
bool m_read_failure { false };
};
}
using AK::BufferStream;