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/Support/DataTypes.h"
23 template<class T> class OwningPtr;
25 /// MemoryBuffer - This interface provides simple read-only access to a block
26 /// of memory, and provides simple methods for reading files and standard input
27 /// into a memory buffer. In addition to basic access to the characters in the
28 /// file, this interface guarantees you can read one character past the end of
29 /// the file, and that this character will read as '\0'.
31 /// The '\0' guarantee is needed to support an optimization -- it's intended to
32 /// be more efficient for clients which are reading all the data to stop
33 /// reading when they encounter a '\0' than to continually check the file
34 /// position to see if it has reached the end of the file.
36 const char *BufferStart; // Start of the buffer.
37 const char *BufferEnd; // End of the buffer.
39 MemoryBuffer(const MemoryBuffer &); // DO NOT IMPLEMENT
40 MemoryBuffer &operator=(const MemoryBuffer &); // DO NOT IMPLEMENT
43 void init(const char *BufStart, const char *BufEnd,
44 bool RequiresNullTerminator);
46 virtual ~MemoryBuffer();
48 const char *getBufferStart() const { return BufferStart; }
49 const char *getBufferEnd() const { return BufferEnd; }
50 size_t getBufferSize() const { return BufferEnd-BufferStart; }
52 StringRef getBuffer() const {
53 return StringRef(BufferStart, getBufferSize());
56 /// getBufferIdentifier - Return an identifier for this buffer, typically the
57 /// filename it was read from.
58 virtual const char *getBufferIdentifier() const {
59 return "Unknown buffer";
62 /// getFile - Open the specified file as a MemoryBuffer, returning a new
63 /// MemoryBuffer if successful, otherwise returning null. If FileSize is
64 /// specified, this means that the client knows that the file exists and that
65 /// it has the specified size.
66 static error_code getFile(StringRef Filename, OwningPtr<MemoryBuffer> &result,
67 int64_t FileSize = -1,
68 bool RequiresNullTerminator = true);
69 static error_code getFile(const char *Filename,
70 OwningPtr<MemoryBuffer> &result,
71 int64_t FileSize = -1,
72 bool RequiresNullTerminator = true);
74 /// getOpenFile - Given an already-open file descriptor, read the file and
75 /// return a MemoryBuffer.
76 static error_code getOpenFile(int FD, const char *Filename,
77 OwningPtr<MemoryBuffer> &result,
81 bool RequiresNullTerminator = true);
83 /// getMemBuffer - Open the specified memory range as a MemoryBuffer. Note
84 /// that InputData must be null terminated if RequiresNullTerminator is true.
85 static MemoryBuffer *getMemBuffer(StringRef InputData,
86 StringRef BufferName = "",
87 bool RequiresNullTerminator = true);
89 /// getMemBufferCopy - Open the specified memory range as a MemoryBuffer,
90 /// copying the contents and taking ownership of it. InputData does not
91 /// have to be null terminated.
92 static MemoryBuffer *getMemBufferCopy(StringRef InputData,
93 StringRef BufferName = "");
95 /// getNewMemBuffer - Allocate a new MemoryBuffer of the specified size that
96 /// is completely initialized to zeros. Note that the caller should
97 /// initialize the memory allocated by this method. The memory is owned by
98 /// the MemoryBuffer object.
99 static MemoryBuffer *getNewMemBuffer(size_t Size, StringRef BufferName = "");
101 /// getNewUninitMemBuffer - Allocate a new MemoryBuffer of the specified size
102 /// that is not initialized. Note that the caller should initialize the
103 /// memory allocated by this method. The memory is owned by the MemoryBuffer
105 static MemoryBuffer *getNewUninitMemBuffer(size_t Size,
106 StringRef BufferName = "");
108 /// getSTDIN - Read all of stdin into a file buffer, and return it.
109 /// If an error occurs, this returns null and sets ec.
110 static error_code getSTDIN(OwningPtr<MemoryBuffer> &result);
113 /// getFileOrSTDIN - Open the specified file as a MemoryBuffer, or open stdin
114 /// if the Filename is "-". If an error occurs, this returns null and sets
116 static error_code getFileOrSTDIN(StringRef Filename,
117 OwningPtr<MemoryBuffer> &result,
118 int64_t FileSize = -1);
119 static error_code getFileOrSTDIN(const char *Filename,
120 OwningPtr<MemoryBuffer> &result,
121 int64_t FileSize = -1);
124 //===--------------------------------------------------------------------===//
125 // Provided for performance analysis.
126 //===--------------------------------------------------------------------===//
128 /// The kind of memory backing used to support the MemoryBuffer.
134 /// Return information on the memory mechanism used to support the
136 virtual BufferKind getBufferKind() const = 0;
139 } // end namespace llvm