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-c/Support.h"
18 #include "llvm/ADT/Twine.h"
19 #include "llvm/Support/CBindingWrapping.h"
20 #include "llvm/Support/Compiler.h"
21 #include "llvm/Support/DataTypes.h"
27 template<class T> class OwningPtr;
29 /// MemoryBuffer - This interface provides simple read-only access to a block
30 /// of memory, and provides simple methods for reading files and standard input
31 /// into a memory buffer. In addition to basic access to the characters in the
32 /// file, this interface guarantees you can read one character past the end of
33 /// the file, and that this character will read as '\0'.
35 /// The '\0' guarantee is needed to support an optimization -- it's intended to
36 /// be more efficient for clients which are reading all the data to stop
37 /// reading when they encounter a '\0' than to continually check the file
38 /// position to see if it has reached the end of the file.
40 const char *BufferStart; // Start of the buffer.
41 const char *BufferEnd; // End of the buffer.
43 MemoryBuffer(const MemoryBuffer &) LLVM_DELETED_FUNCTION;
44 MemoryBuffer &operator=(const MemoryBuffer &) LLVM_DELETED_FUNCTION;
47 void init(const char *BufStart, const char *BufEnd,
48 bool RequiresNullTerminator);
50 virtual ~MemoryBuffer();
52 const char *getBufferStart() const { return BufferStart; }
53 const char *getBufferEnd() const { return BufferEnd; }
54 size_t getBufferSize() const { return BufferEnd-BufferStart; }
56 StringRef getBuffer() const {
57 return StringRef(BufferStart, getBufferSize());
60 /// getBufferIdentifier - Return an identifier for this buffer, typically the
61 /// filename it was read from.
62 virtual const char *getBufferIdentifier() const {
63 return "Unknown buffer";
66 /// getFile - Open the specified file as a MemoryBuffer, returning a new
67 /// MemoryBuffer if successful, otherwise returning null. If FileSize is
68 /// specified, this means that the client knows that the file exists and that
69 /// it has the specified size.
70 static error_code getFile(Twine Filename, OwningPtr<MemoryBuffer> &Result,
71 int64_t FileSize = -1,
72 bool RequiresNullTerminator = true);
73 static error_code getFile(Twine Filename,
74 std::unique_ptr<MemoryBuffer> &Result,
75 int64_t FileSize = -1,
76 bool RequiresNullTerminator = true);
78 /// Given an already-open file descriptor, map some slice of it into a
79 /// MemoryBuffer. The slice is specified by an \p Offset and \p MapSize.
80 /// Since this is in the middle of a file, the buffer is not null terminated.
81 static error_code getOpenFileSlice(int FD, const char *Filename,
82 OwningPtr<MemoryBuffer> &Result,
83 uint64_t MapSize, int64_t Offset);
84 static error_code getOpenFileSlice(int FD, const char *Filename,
85 std::unique_ptr<MemoryBuffer> &Result,
86 uint64_t MapSize, int64_t Offset);
88 /// Given an already-open file descriptor, read the file and return a
90 static error_code getOpenFile(int FD, const char *Filename,
91 OwningPtr<MemoryBuffer> &Result,
93 bool RequiresNullTerminator = true);
94 static error_code getOpenFile(int FD, const char *Filename,
95 std::unique_ptr<MemoryBuffer> &Result,
97 bool RequiresNullTerminator = true);
99 /// getMemBuffer - Open the specified memory range as a MemoryBuffer. Note
100 /// that InputData must be null terminated if RequiresNullTerminator is true.
101 static MemoryBuffer *getMemBuffer(StringRef InputData,
102 StringRef BufferName = "",
103 bool RequiresNullTerminator = true);
105 /// getMemBufferCopy - Open the specified memory range as a MemoryBuffer,
106 /// copying the contents and taking ownership of it. InputData does not
107 /// have to be null terminated.
108 static MemoryBuffer *getMemBufferCopy(StringRef InputData,
109 StringRef BufferName = "");
111 /// getNewMemBuffer - Allocate a new MemoryBuffer of the specified size that
112 /// is completely initialized to zeros. Note that the caller should
113 /// initialize the memory allocated by this method. The memory is owned by
114 /// the MemoryBuffer object.
115 static MemoryBuffer *getNewMemBuffer(size_t Size, StringRef BufferName = "");
117 /// getNewUninitMemBuffer - Allocate a new MemoryBuffer of the specified size
118 /// that is not initialized. Note that the caller should initialize the
119 /// memory allocated by this method. The memory is owned by the MemoryBuffer
121 static MemoryBuffer *getNewUninitMemBuffer(size_t Size,
122 StringRef BufferName = "");
124 /// getSTDIN - Read all of stdin into a file buffer, and return it.
125 /// If an error occurs, this returns null and sets ec.
126 static error_code getSTDIN(OwningPtr<MemoryBuffer> &Result);
127 static error_code getSTDIN(std::unique_ptr<MemoryBuffer> &Result);
130 /// getFileOrSTDIN - Open the specified file as a MemoryBuffer, or open stdin
131 /// if the Filename is "-". If an error occurs, this returns null and sets
133 static error_code getFileOrSTDIN(StringRef Filename,
134 OwningPtr<MemoryBuffer> &Result,
135 int64_t FileSize = -1);
136 static error_code getFileOrSTDIN(StringRef Filename,
137 std::unique_ptr<MemoryBuffer> &Result,
138 int64_t FileSize = -1);
140 //===--------------------------------------------------------------------===//
141 // Provided for performance analysis.
142 //===--------------------------------------------------------------------===//
144 /// The kind of memory backing used to support the MemoryBuffer.
150 /// Return information on the memory mechanism used to support the
152 virtual BufferKind getBufferKind() const = 0;
155 // Create wrappers for C Binding types (see CBindingWrapping.h).
156 DEFINE_SIMPLE_CONVERSION_FUNCTIONS(MemoryBuffer, LLVMMemoryBufferRef)
158 } // end namespace llvm