MemoryBuffer.h revision 193323
1//===--- MemoryBuffer.h - Memory Buffer Interface ---------------*- 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 defines the MemoryBuffer interface. 11// 12//===----------------------------------------------------------------------===// 13 14#ifndef LLVM_SUPPORT_MEMORYBUFFER_H 15#define LLVM_SUPPORT_MEMORYBUFFER_H 16 17#include "llvm/Support/DataTypes.h" 18#include <string> 19 20namespace llvm { 21 22/// MemoryBuffer - This interface provides simple read-only access to a block 23/// of memory, and provides simple methods for reading files and standard input 24/// into a memory buffer. In addition to basic access to the characters in the 25/// file, this interface guarantees you can read one character past the end of 26/// @verbatim the file, and that this character will read as '\0'. @endverbatim 27class MemoryBuffer { 28 const char *BufferStart; // Start of the buffer. 29 const char *BufferEnd; // End of the buffer. 30 31 /// MustDeleteBuffer - True if we allocated this buffer. If so, the 32 /// destructor must know the delete[] it. 33 bool MustDeleteBuffer; 34protected: 35 MemoryBuffer() : MustDeleteBuffer(false) {} 36 void init(const char *BufStart, const char *BufEnd); 37 void initCopyOf(const char *BufStart, const char *BufEnd); 38public: 39 virtual ~MemoryBuffer(); 40 41 const char *getBufferStart() const { return BufferStart; } 42 const char *getBufferEnd() const { return BufferEnd; } 43 size_t getBufferSize() const { return BufferEnd-BufferStart; } 44 45 /// getBufferIdentifier - Return an identifier for this buffer, typically the 46 /// filename it was read from. 47 virtual const char *getBufferIdentifier() const { 48 return "Unknown buffer"; 49 } 50 51 /// getFile - Open the specified file as a MemoryBuffer, returning a new 52 /// MemoryBuffer if successful, otherwise returning null. If FileSize is 53 /// specified, this means that the client knows that the file exists and that 54 /// it has the specified size. 55 static MemoryBuffer *getFile(const char *Filename, 56 std::string *ErrStr = 0, 57 int64_t FileSize = -1); 58 59 /// getMemBuffer - Open the specified memory range as a MemoryBuffer. Note 60 /// that EndPtr[0] must be a null byte and be accessible! 61 static MemoryBuffer *getMemBuffer(const char *StartPtr, const char *EndPtr, 62 const char *BufferName = ""); 63 64 /// getMemBufferCopy - Open the specified memory range as a MemoryBuffer, 65 /// copying the contents and taking ownership of it. This has no requirements 66 /// on EndPtr[0]. 67 static MemoryBuffer *getMemBufferCopy(const char *StartPtr,const char *EndPtr, 68 const char *BufferName = ""); 69 70 /// getNewMemBuffer - Allocate a new MemoryBuffer of the specified size that 71 /// is completely initialized to zeros. Note that the caller should 72 /// initialize the memory allocated by this method. The memory is owned by 73 /// the MemoryBuffer object. 74 static MemoryBuffer *getNewMemBuffer(size_t Size, 75 const char *BufferName = ""); 76 77 /// getNewUninitMemBuffer - Allocate a new MemoryBuffer of the specified size 78 /// that is not initialized. Note that the caller should initialize the 79 /// memory allocated by this method. The memory is owned by the MemoryBuffer 80 /// object. 81 static MemoryBuffer *getNewUninitMemBuffer(size_t Size, 82 const char *BufferName = ""); 83 84 /// getSTDIN - Read all of stdin into a file buffer, and return it. This 85 /// returns null if stdin is empty. 86 static MemoryBuffer *getSTDIN(); 87 88 89 /// getFileOrSTDIN - Open the specified file as a MemoryBuffer, or open stdin 90 /// if the Filename is "-". If an error occurs, this returns null and fills 91 /// in *ErrStr with a reason. If stdin is empty, this API (unlike getSTDIN) 92 /// returns an empty buffer. 93 static MemoryBuffer *getFileOrSTDIN(const char *Filename, 94 std::string *ErrStr = 0, 95 int64_t FileSize = -1); 96 97 /// getFileOrSTDIN - Open the specified file as a MemoryBuffer, or open stdin 98 /// if the Filename is "-". If an error occurs, this returns null and fills 99 /// in *ErrStr with a reason. 100 static MemoryBuffer *getFileOrSTDIN(const std::string &FN, 101 std::string *ErrStr = 0, 102 int64_t FileSize = -1) { 103 return getFileOrSTDIN(FN.c_str(), ErrStr, FileSize); 104 } 105}; 106 107} // end namespace llvm 108 109#endif 110