286 lines
		
	
	
		
			10 KiB
		
	
	
	
		
			C++
		
	
	
	
			
		
		
	
	
			286 lines
		
	
	
		
			10 KiB
		
	
	
	
		
			C++
		
	
	
	
| //===-- DataEncoder.cpp -----------------------------------------*- C++ -*-===//
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| //
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| //                     The LLVM Compiler Infrastructure
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| //
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| // This file is distributed under the University of Illinois Open Source
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| // License. See LICENSE.TXT for details.
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| //
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| //===----------------------------------------------------------------------===//
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| 
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| #include "lldb/Utility/DataEncoder.h"
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| 
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| #include "lldb/Utility/DataBuffer.h"
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| #include "lldb/Utility/Endian.h"
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| 
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| #include "llvm/Support/ErrorHandling.h" // for llvm_unreachable
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| #include "llvm/Support/MathExtras.h"
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| 
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| #include <cassert>
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| #include <cstddef>
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| 
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| #include <string.h>
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| 
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| using namespace lldb;
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| using namespace lldb_private;
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| 
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| static inline void WriteInt16(unsigned char *ptr, unsigned offset,
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|                               uint16_t value) {
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|   *(uint16_t *)(ptr + offset) = value;
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| }
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| 
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| static inline void WriteInt32(unsigned char *ptr, unsigned offset,
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|                               uint32_t value) {
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|   *(uint32_t *)(ptr + offset) = value;
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| }
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| 
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| static inline void WriteInt64(unsigned char *ptr, unsigned offset,
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|                               uint64_t value) {
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|   *(uint64_t *)(ptr + offset) = value;
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| }
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| 
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| static inline void WriteSwappedInt16(unsigned char *ptr, unsigned offset,
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|                                      uint16_t value) {
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|   *(uint16_t *)(ptr + offset) = llvm::ByteSwap_16(value);
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| }
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| 
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| static inline void WriteSwappedInt32(unsigned char *ptr, unsigned offset,
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|                                      uint32_t value) {
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|   *(uint32_t *)(ptr + offset) = llvm::ByteSwap_32(value);
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| }
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| 
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| static inline void WriteSwappedInt64(unsigned char *ptr, unsigned offset,
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|                                      uint64_t value) {
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|   *(uint64_t *)(ptr + offset) = llvm::ByteSwap_64(value);
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| }
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| 
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| //----------------------------------------------------------------------
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| // Default constructor.
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| //----------------------------------------------------------------------
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| DataEncoder::DataEncoder()
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|     : m_start(nullptr), m_end(nullptr),
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|       m_byte_order(endian::InlHostByteOrder()), m_addr_size(sizeof(void *)),
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|       m_data_sp() {}
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| 
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| //----------------------------------------------------------------------
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| // This constructor allows us to use data that is owned by someone else.
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| // The data must stay around as long as this object is valid.
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| //----------------------------------------------------------------------
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| DataEncoder::DataEncoder(void *data, uint32_t length, ByteOrder endian,
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|                          uint8_t addr_size)
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|     : m_start((uint8_t *)data), m_end((uint8_t *)data + length),
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|       m_byte_order(endian), m_addr_size(addr_size), m_data_sp() {}
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| 
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| //----------------------------------------------------------------------
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| // Make a shared pointer reference to the shared data in "data_sp" and
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| // set the endian swapping setting to "swap", and the address size to
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| // "addr_size". The shared data reference will ensure the data lives
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| // as long as any DataEncoder objects exist that have a reference to
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| // this data.
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| //----------------------------------------------------------------------
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| DataEncoder::DataEncoder(const DataBufferSP &data_sp, ByteOrder endian,
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|                          uint8_t addr_size)
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|     : m_start(nullptr), m_end(nullptr), m_byte_order(endian),
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|       m_addr_size(addr_size), m_data_sp() {
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|   SetData(data_sp);
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| }
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| 
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| DataEncoder::~DataEncoder() = default;
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| 
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| //------------------------------------------------------------------
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| // Clears the object contents back to a default invalid state, and
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| // release any references to shared data that this object may
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| // contain.
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| //------------------------------------------------------------------
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| void DataEncoder::Clear() {
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|   m_start = nullptr;
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|   m_end = nullptr;
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|   m_byte_order = endian::InlHostByteOrder();
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|   m_addr_size = sizeof(void *);
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|   m_data_sp.reset();
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| }
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| 
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| //------------------------------------------------------------------
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| // If this object contains shared data, this function returns the
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| // offset into that shared data. Else zero is returned.
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| //------------------------------------------------------------------
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| size_t DataEncoder::GetSharedDataOffset() const {
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|   if (m_start != nullptr) {
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|     const DataBuffer *data = m_data_sp.get();
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|     if (data != nullptr) {
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|       const uint8_t *data_bytes = data->GetBytes();
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|       if (data_bytes != nullptr) {
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|         assert(m_start >= data_bytes);
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|         return m_start - data_bytes;
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|       }
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|     }
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|   }
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|   return 0;
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| }
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| 
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| //----------------------------------------------------------------------
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| // Set the data with which this object will extract from to data
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| // starting at BYTES and set the length of the data to LENGTH bytes
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| // long. The data is externally owned must be around at least as
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| // long as this object points to the data. No copy of the data is
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| // made, this object just refers to this data and can extract from
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| // it. If this object refers to any shared data upon entry, the
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| // reference to that data will be released. Is SWAP is set to true,
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| // any data extracted will be endian swapped.
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| //----------------------------------------------------------------------
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| uint32_t DataEncoder::SetData(void *bytes, uint32_t length, ByteOrder endian) {
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|   m_byte_order = endian;
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|   m_data_sp.reset();
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|   if (bytes == nullptr || length == 0) {
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|     m_start = nullptr;
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|     m_end = nullptr;
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|   } else {
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|     m_start = (uint8_t *)bytes;
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|     m_end = m_start + length;
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|   }
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|   return GetByteSize();
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| }
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| 
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| //----------------------------------------------------------------------
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| // Assign the data for this object to be a subrange of the shared
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| // data in "data_sp" starting "data_offset" bytes into "data_sp"
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| // and ending "data_length" bytes later. If "data_offset" is not
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| // a valid offset into "data_sp", then this object will contain no
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| // bytes. If "data_offset" is within "data_sp" yet "data_length" is
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| // too large, the length will be capped at the number of bytes
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| // remaining in "data_sp". A ref counted pointer to the data in
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| // "data_sp" will be made in this object IF the number of bytes this
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| // object refers to in greater than zero (if at least one byte was
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| // available starting at "data_offset") to ensure the data stays
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| // around as long as it is needed. The address size and endian swap
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| // settings will remain unchanged from their current settings.
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| //----------------------------------------------------------------------
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| uint32_t DataEncoder::SetData(const DataBufferSP &data_sp, uint32_t data_offset,
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|                               uint32_t data_length) {
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|   m_start = m_end = nullptr;
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| 
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|   if (data_length > 0) {
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|     m_data_sp = data_sp;
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|     if (data_sp) {
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|       const size_t data_size = data_sp->GetByteSize();
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|       if (data_offset < data_size) {
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|         m_start = data_sp->GetBytes() + data_offset;
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|         const size_t bytes_left = data_size - data_offset;
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|         // Cap the length of we asked for too many
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|         if (data_length <= bytes_left)
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|           m_end = m_start + data_length; // We got all the bytes we wanted
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|         else
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|           m_end = m_start + bytes_left; // Not all the bytes requested were
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|                                         // available in the shared data
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|       }
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|     }
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|   }
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| 
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|   uint32_t new_size = GetByteSize();
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| 
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|   // Don't hold a shared pointer to the data buffer if we don't share
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|   // any valid bytes in the shared buffer.
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|   if (new_size == 0)
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|     m_data_sp.reset();
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| 
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|   return new_size;
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| }
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| 
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| //----------------------------------------------------------------------
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| // Extract a single unsigned char from the binary data and update
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| // the offset pointed to by "offset_ptr".
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| //
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| // RETURNS the byte that was extracted, or zero on failure.
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| //----------------------------------------------------------------------
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| uint32_t DataEncoder::PutU8(uint32_t offset, uint8_t value) {
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|   if (ValidOffset(offset)) {
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|     m_start[offset] = value;
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|     return offset + 1;
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|   }
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|   return UINT32_MAX;
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| }
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| 
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| uint32_t DataEncoder::PutU16(uint32_t offset, uint16_t value) {
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|   if (ValidOffsetForDataOfSize(offset, sizeof(value))) {
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|     if (m_byte_order != endian::InlHostByteOrder())
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|       WriteSwappedInt16(m_start, offset, value);
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|     else
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|       WriteInt16(m_start, offset, value);
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| 
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|     return offset + sizeof(value);
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|   }
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|   return UINT32_MAX;
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| }
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| 
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| uint32_t DataEncoder::PutU32(uint32_t offset, uint32_t value) {
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|   if (ValidOffsetForDataOfSize(offset, sizeof(value))) {
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|     if (m_byte_order != endian::InlHostByteOrder())
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|       WriteSwappedInt32(m_start, offset, value);
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|     else
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|       WriteInt32(m_start, offset, value);
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| 
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|     return offset + sizeof(value);
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|   }
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|   return UINT32_MAX;
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| }
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| 
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| uint32_t DataEncoder::PutU64(uint32_t offset, uint64_t value) {
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|   if (ValidOffsetForDataOfSize(offset, sizeof(value))) {
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|     if (m_byte_order != endian::InlHostByteOrder())
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|       WriteSwappedInt64(m_start, offset, value);
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|     else
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|       WriteInt64(m_start, offset, value);
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| 
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|     return offset + sizeof(value);
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|   }
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|   return UINT32_MAX;
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| }
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| 
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| //----------------------------------------------------------------------
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| // Extract a single integer value from the data and update the offset
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| // pointed to by "offset_ptr". The size of the extracted integer
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| // is specified by the "byte_size" argument. "byte_size" should have
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| // a value >= 1 and <= 8 since the return value is only 64 bits
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| // wide. Any "byte_size" values less than 1 or greater than 8 will
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| // result in nothing being extracted, and zero being returned.
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| //
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| // RETURNS the integer value that was extracted, or zero on failure.
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| //----------------------------------------------------------------------
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| uint32_t DataEncoder::PutMaxU64(uint32_t offset, uint32_t byte_size,
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|                                 uint64_t value) {
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|   switch (byte_size) {
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|   case 1:
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|     return PutU8(offset, value);
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|   case 2:
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|     return PutU16(offset, value);
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|   case 4:
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|     return PutU32(offset, value);
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|   case 8:
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|     return PutU64(offset, value);
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|   default:
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|     llvm_unreachable("GetMax64 unhandled case!");
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|   }
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|   return UINT32_MAX;
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| }
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| 
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| uint32_t DataEncoder::PutData(uint32_t offset, const void *src,
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|                               uint32_t src_len) {
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|   if (src == nullptr || src_len == 0)
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|     return offset;
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| 
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|   if (ValidOffsetForDataOfSize(offset, src_len)) {
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|     memcpy(m_start + offset, src, src_len);
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|     return offset + src_len;
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|   }
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|   return UINT32_MAX;
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| }
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| 
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| uint32_t DataEncoder::PutAddress(uint32_t offset, lldb::addr_t addr) {
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|   return PutMaxU64(offset, GetAddressByteSize(), addr);
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| }
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| 
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| uint32_t DataEncoder::PutCString(uint32_t offset, const char *cstr) {
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|   if (cstr != nullptr)
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|     return PutData(offset, cstr, strlen(cstr) + 1);
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|   return UINT32_MAX;
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| }
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