1 //===--- MemoryBuffer.h - Memory Buffer Interface ---------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines the MemoryBuffer interface.
12 //===----------------------------------------------------------------------===//
14 #ifndef LLVM_SUPPORT_MEMORYBUFFER_H
15 #define LLVM_SUPPORT_MEMORYBUFFER_H
17 #include "llvm/ADT/StringRef.h"
18 #include "llvm/System/DataTypes.h"
23 /// MemoryBuffer - This interface provides simple read-only access to a block
24 /// of memory, and provides simple methods for reading files and standard input
25 /// into a memory buffer. In addition to basic access to the characters in the
26 /// file, this interface guarantees you can read one character past the end of
27 /// the file, and that this character will read as '\0'.
29 /// The '\0' guarantee is needed to support an optimization -- it's intended to
30 /// be more efficient for clients which are reading all the data to stop
31 /// reading when they encounter a '\0' than to continually check the file
32 /// position to see if it has reached the end of the file.
34 const char *BufferStart; // Start of the buffer.
35 const char *BufferEnd; // End of the buffer.
37 MemoryBuffer(const MemoryBuffer &); // DO NOT IMPLEMENT
38 MemoryBuffer &operator=(const MemoryBuffer &); // DO NOT IMPLEMENT
41 void init(const char *BufStart, const char *BufEnd);
43 virtual ~MemoryBuffer();
45 const char *getBufferStart() const { return BufferStart; }
46 const char *getBufferEnd() const { return BufferEnd; }
47 size_t getBufferSize() const { return BufferEnd-BufferStart; }
49 StringRef getBuffer() const {
50 return StringRef(BufferStart, getBufferSize());
53 /// getBufferIdentifier - Return an identifier for this buffer, typically the
54 /// filename it was read from.
55 virtual const char *getBufferIdentifier() const {
56 return "Unknown buffer";
59 /// getFile - Open the specified file as a MemoryBuffer, returning a new
60 /// MemoryBuffer if successful, otherwise returning null. If FileSize is
61 /// specified, this means that the client knows that the file exists and that
62 /// it has the specified size.
63 static MemoryBuffer *getFile(StringRef Filename, std::string *ErrStr = 0,
64 int64_t FileSize = -1);
65 static MemoryBuffer *getFile(const char *Filename, std::string *ErrStr = 0,
66 int64_t FileSize = -1);
68 /// getOpenFile - Given an already-open file descriptor, read the file and
69 /// return a MemoryBuffer. This takes ownership of the descriptor,
70 /// immediately closing it after reading the file.
71 static MemoryBuffer *getOpenFile(int FD, const char *Filename,
72 std::string *ErrStr = 0,
73 int64_t FileSize = -1);
75 /// getMemBuffer - Open the specified memory range as a MemoryBuffer. Note
76 /// that InputData must be null terminated.
77 static MemoryBuffer *getMemBuffer(StringRef InputData,
78 StringRef BufferName = "");
80 /// getMemBufferCopy - Open the specified memory range as a MemoryBuffer,
81 /// copying the contents and taking ownership of it. InputData does not
82 /// have to be null terminated.
83 static MemoryBuffer *getMemBufferCopy(StringRef InputData,
84 StringRef BufferName = "");
86 /// getNewMemBuffer - Allocate a new MemoryBuffer of the specified size that
87 /// is completely initialized to zeros. Note that the caller should
88 /// initialize the memory allocated by this method. The memory is owned by
89 /// the MemoryBuffer object.
90 static MemoryBuffer *getNewMemBuffer(size_t Size, StringRef BufferName = "");
92 /// getNewUninitMemBuffer - Allocate a new MemoryBuffer of the specified size
93 /// that is not initialized. Note that the caller should initialize the
94 /// memory allocated by this method. The memory is owned by the MemoryBuffer
96 static MemoryBuffer *getNewUninitMemBuffer(size_t Size,
97 StringRef BufferName = "");
99 /// getSTDIN - Read all of stdin into a file buffer, and return it.
100 /// If an error occurs, this returns null and fills in *ErrStr with a reason.
101 static MemoryBuffer *getSTDIN(std::string *ErrStr = 0);
104 /// getFileOrSTDIN - Open the specified file as a MemoryBuffer, or open stdin
105 /// if the Filename is "-". If an error occurs, this returns null and fills
106 /// in *ErrStr with a reason.
107 static MemoryBuffer *getFileOrSTDIN(StringRef Filename,
108 std::string *ErrStr = 0,
109 int64_t FileSize = -1);
110 static MemoryBuffer *getFileOrSTDIN(const char *Filename,
111 std::string *ErrStr = 0,
112 int64_t FileSize = -1);
115 } // end namespace llvm