LLVM  3.7.0
ObjectMemoryBuffer.h
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1 //===- ObjectMemoryBuffer.h - SmallVector-backed MemoryBuffrer -*- C++ -*-===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file declares a wrapper class to hold the memory into which an
11 // object will be generated.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #ifndef LLVM_EXECUTIONENGINE_OBJECTMEMORYBUFFER_H
16 #define LLVM_EXECUTIONENGINE_OBJECTMEMORYBUFFER_H
17 
18 #include "llvm/ADT/SmallVector.h"
21 
22 namespace llvm {
23 
24 /// \brief SmallVector-backed MemoryBuffer instance.
25 ///
26 /// This class enables efficient construction of MemoryBuffers from SmallVector
27 /// instances. This is useful for MCJIT and Orc, where object files are streamed
28 /// into SmallVectors, then inspected using ObjectFile (which takes a
29 /// MemoryBuffer).
31 public:
32 
33  /// \brief Construct an ObjectMemoryBuffer from the given SmallVector r-value.
34  ///
35  /// FIXME: It'd be nice for this to be a non-templated constructor taking a
36  /// SmallVectorImpl here instead of a templated one taking a SmallVector<N>,
37  /// but SmallVector's move-construction/assignment currently only take
38  /// SmallVectors. If/when that is fixed we can simplify this constructor and
39  /// the following one.
41  : SV(std::move(SV)), BufferName("<in-memory object>") {
42  init(this->SV.begin(), this->SV.end(), false);
43  }
44 
45  /// \brief Construct a named ObjectMemoryBuffer from the given SmallVector
46  /// r-value and StringRef.
48  : SV(std::move(SV)), BufferName(Name) {
49  init(this->SV.begin(), this->SV.end(), false);
50  }
51 
52  const char* getBufferIdentifier() const override { return BufferName.c_str(); }
53 
54  BufferKind getBufferKind() const override { return MemoryBuffer_Malloc; }
55 
56 private:
58  std::string BufferName;
59 };
60 
61 } // namespace llvm
62 
63 #endif
void init(const char *BufStart, const char *BufEnd, bool RequiresNullTerminator)
init - Initialize this MemoryBuffer as a reference to externally allocated memory, memory that we know is already null terminated.
const char * getBufferIdentifier() const override
Return an identifier for this buffer, typically the filename it was read from.
ObjectMemoryBuffer(SmallVectorImpl< char > &&SV, StringRef Name)
Construct a named ObjectMemoryBuffer from the given SmallVector r-value and StringRef.
ObjectMemoryBuffer(SmallVectorImpl< char > &&SV)
Construct an ObjectMemoryBuffer from the given SmallVector r-value.
This interface provides simple read-only access to a block of memory, and provides simple methods for...
Definition: MemoryBuffer.h:37
SmallVector-backed MemoryBuffer instance.
BufferKind
The kind of memory backing used to support the MemoryBuffer.
Definition: MemoryBuffer.h:136
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:40
BufferKind getBufferKind() const override
Return information on the memory mechanism used to support the MemoryBuffer.