1 //===---- ObjectBuffer.h - Utility class to wrap object image memory -----===//
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3 // The LLVM Compiler Infrastructure
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5 // This file is distributed under the University of Illinois Open Source
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6 // License. See LICENSE.TXT for details.
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8 //===----------------------------------------------------------------------===//
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10 // This file declares a wrapper class to hold the memory into which an
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11 // object will be generated.
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13 //===----------------------------------------------------------------------===//
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15 #ifndef LLVM_EXECUTIONENGINE_OBJECTBUFFER_H
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16 #define LLVM_EXECUTIONENGINE_OBJECTBUFFER_H
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18 #include "llvm/ADT/SmallVector.h"
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19 #include "llvm/ADT/OwningPtr.h"
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20 #include "llvm/Support/raw_ostream.h"
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21 #include "llvm/Support/MemoryBuffer.h"
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25 /// ObjectBuffer - This class acts as a container for the memory buffer used during
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26 /// generation and loading of executable objects using MCJIT and RuntimeDyld. The
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27 /// underlying memory for the object will be owned by the ObjectBuffer instance
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28 /// throughout its lifetime. The getMemBuffer() method provides a way to create a
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29 /// MemoryBuffer wrapper object instance to be owned by other classes (such as
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30 /// ObjectFile) as needed, but the MemoryBuffer instance returned does not own the
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31 /// actual memory it points to.
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32 class ObjectBuffer {
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35 ObjectBuffer(MemoryBuffer* Buf) : Buffer(Buf) {}
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36 virtual ~ObjectBuffer() {}
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38 /// getMemBuffer - Like MemoryBuffer::getMemBuffer() this function
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39 /// returns a pointer to an object that is owned by the caller. However,
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40 /// the caller does not take ownership of the underlying memory.
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41 MemoryBuffer *getMemBuffer() const {
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42 return MemoryBuffer::getMemBuffer(Buffer->getBuffer(), "", false);
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45 const char *getBufferStart() const { return Buffer->getBufferStart(); }
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46 size_t getBufferSize() const { return Buffer->getBufferSize(); }
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49 // The memory contained in an ObjectBuffer
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50 OwningPtr<MemoryBuffer> Buffer;
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53 /// ObjectBufferStream - This class encapsulates the SmallVector and
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54 /// raw_svector_ostream needed to generate an object using MC code emission
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55 /// while providing a common ObjectBuffer interface for access to the
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56 /// memory once the object has been generated.
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57 class ObjectBufferStream : public ObjectBuffer {
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59 ObjectBufferStream() : OS(SV) {}
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60 virtual ~ObjectBufferStream() {}
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62 raw_ostream &getOStream() { return OS; }
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67 // Make the data accessible via the ObjectBuffer::Buffer
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68 Buffer.reset(MemoryBuffer::getMemBuffer(StringRef(SV.data(), SV.size()),
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74 SmallVector<char, 4096> SV; // Working buffer into which we JIT.
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75 raw_svector_ostream OS; // streaming wrapper
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