LLVM  10.0.0svn
FileWriter.h
Go to the documentation of this file.
1 //===- FileWriter.h ---------------------------------------------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #ifndef LLVM_DEBUGINFO_GSYM_FILEWRITER_H
10 #define LLVM_DEBUGINFO_GSYM_FILEWRITER_H
11 
12 #include "llvm/ADT/ArrayRef.h"
13 #include "llvm/Support/Endian.h"
14 
15 #include <stddef.h>
16 #include <stdint.h>
17 #include <sys/types.h>
18 
19 namespace llvm {
20 class raw_pwrite_stream;
21 
22 namespace gsym {
23 
24 /// A simplified binary data writer class that doesn't require targets, target
25 /// definitions, architectures, or require any other optional compile time
26 /// libraries to be enabled via the build process. This class needs the ability
27 /// to seek to different spots in the binary stream that is produces to fixup
28 /// offsets and sizes.
29 class FileWriter {
31  llvm::support::endianness ByteOrder;
32 public:
34  : OS(S), ByteOrder(B) {}
35  ~FileWriter();
36  /// Write a single uint8_t value into the stream at the current file
37  /// position.
38  ///
39  /// \param Value The value to write into the stream.
40  void writeU8(uint8_t Value);
41 
42  /// Write a single uint16_t value into the stream at the current file
43  /// position. The value will be byte swapped if needed to match the byte
44  /// order specified during construction.
45  ///
46  /// \param Value The value to write into the stream.
47  void writeU16(uint16_t Value);
48 
49  /// Write a single uint32_t value into the stream at the current file
50  /// position. The value will be byte swapped if needed to match the byte
51  /// order specified during construction.
52  ///
53  /// \param Value The value to write into the stream.
54  void writeU32(uint32_t Value);
55 
56  /// Write a single uint64_t value into the stream at the current file
57  /// position. The value will be byte swapped if needed to match the byte
58  /// order specified during construction.
59  ///
60  /// \param Value The value to write into the stream.
61  void writeU64(uint64_t Value);
62 
63  /// Write the value into the stream encoded using signed LEB128 at the
64  /// current file position.
65  ///
66  /// \param Value The value to write into the stream.
67  void writeSLEB(int64_t Value);
68 
69  /// Write the value into the stream encoded using unsigned LEB128 at the
70  /// current file position.
71  ///
72  /// \param Value The value to write into the stream.
73  void writeULEB(uint64_t Value);
74 
75  /// Write an array of uint8_t values into the stream at the current file
76  /// position.
77  ///
78  /// \param Data An array of values to write into the stream.
80 
81  /// Write a NULL terminated C string into the stream at the current file
82  /// position. The entire contents of Str will be written into the steam at
83  /// the current file position and then an extra NULL termation byte will be
84  /// written. It is up to the user to ensure that Str doesn't contain any NULL
85  /// characters unless the additional NULL characters are desired.
86  ///
87  /// \param Str The value to write into the stream.
89 
90  /// Fixup a uint32_t value at the specified offset in the stream. This
91  /// function will save the current file position, seek to the specified
92  /// offset, overwrite the data using Value, and then restore the file
93  /// position to the previous file position.
94  ///
95  /// \param Value The value to write into the stream.
96  /// \param Offset The offset at which to write the Value within the stream.
97  void fixup32(uint32_t Value, uint64_t Offset);
98 
99  /// Pad with zeroes at the current file position until the current file
100  /// position matches the specified alignment.
101  ///
102  /// \param Align An integer speciying the desired alignment. This does not
103  /// need to be a power of two.
104  void alignTo(size_t Align);
105 
106  /// Return the current offset within the file.
107  ///
108  /// \return The unsigned offset from the start of the file of the current
109  /// file position.
110  uint64_t tell();
111 
113  return OS;
114  }
115 
116 private:
117  FileWriter(const FileWriter &rhs) = delete;
118  void operator=(const FileWriter &rhs) = delete;
119 };
120 
121 } // namespace gsym
122 } // namespace llvm
123 
124 #endif // #ifndef LLVM_DEBUGINFO_GSYM_FILEWRITER_H
This class represents lattice values for constants.
Definition: AllocatorList.h:23
void writeU8(uint8_t Value)
Write a single uint8_t value into the stream at the current file position.
Definition: FileWriter.cpp:34
void writeULEB(uint64_t Value)
Write the value into the stream encoded using unsigned LEB128 at the current file position...
Definition: FileWriter.cpp:27
void writeNullTerminated(llvm::StringRef Str)
Write a NULL terminated C string into the stream at the current file position.
Definition: FileWriter.cpp:63
void alignTo(size_t Align)
Pad with zeroes at the current file position until the current file position matches the specified al...
Definition: FileWriter.cpp:71
void fixup32(uint32_t Value, uint64_t Offset)
Fixup a uint32_t value at the specified offset in the stream.
Definition: FileWriter.cpp:53
void writeU32(uint32_t Value)
Write a single uint32_t value into the stream at the current file position.
Definition: FileWriter.cpp:43
void writeU64(uint64_t Value)
Write a single uint64_t value into the stream at the current file position.
Definition: FileWriter.cpp:48
static GCRegistry::Add< OcamlGC > B("ocaml", "ocaml 3.10-compatible GC")
void writeData(llvm::ArrayRef< uint8_t > Data)
Write an array of uint8_t values into the stream at the current file position.
Definition: FileWriter.cpp:59
void writeSLEB(int64_t Value)
Write the value into the stream encoded using signed LEB128 at the current file position.
Definition: FileWriter.cpp:20
A simplified binary data writer class that doesn&#39;t require targets, target definitions, architectures, or require any other optional compile time libraries to be enabled via the build process.
Definition: FileWriter.h:29
FileWriter(llvm::raw_pwrite_stream &S, llvm::support::endianness B)
Definition: FileWriter.h:33
This struct is a compact representation of a valid (non-zero power of two) alignment.
Definition: Alignment.h:40
uint64_t tell()
Return the current offset within the file.
Definition: FileWriter.cpp:67
llvm::raw_pwrite_stream & get_stream()
Definition: FileWriter.h:112
void writeU16(uint16_t Value)
Write a single uint16_t value into the stream at the current file position.
Definition: FileWriter.cpp:38
An abstract base class for streams implementations that also support a pwrite operation.
Definition: raw_ostream.h:359
LLVM Value Representation.
Definition: Value.h:74
StringRef - Represent a constant reference to a string, i.e.
Definition: StringRef.h:48