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 { 30 llvm::raw_pwrite_stream &OS; 31 llvm::endianness ByteOrder; 32 33 public: 34 FileWriter(llvm::raw_pwrite_stream &S, llvm::endianness B) 35 : OS(S), ByteOrder(B) {} 36 ~FileWriter(); 37 /// Write a single uint8_t value into the stream at the current file 38 /// position. 39 /// 40 /// \param Value The value to write into the stream. 41 void writeU8(uint8_t Value); 42 43 /// Write a single uint16_t value into the stream at the current file 44 /// position. The value will be byte swapped if needed to match the byte 45 /// order specified during construction. 46 /// 47 /// \param Value The value to write into the stream. 48 void writeU16(uint16_t Value); 49 50 /// Write a single uint32_t value into the stream at the current file 51 /// position. The value will be byte swapped if needed to match the byte 52 /// order specified during construction. 53 /// 54 /// \param Value The value to write into the stream. 55 void writeU32(uint32_t Value); 56 57 /// Write a single uint64_t value into the stream at the current file 58 /// position. The value will be byte swapped if needed to match the byte 59 /// order specified during construction. 60 /// 61 /// \param Value The value to write into the stream. 62 void writeU64(uint64_t Value); 63 64 /// Write the value into the stream encoded using signed LEB128 at the 65 /// current file position. 66 /// 67 /// \param Value The value to write into the stream. 68 void writeSLEB(int64_t Value); 69 70 /// Write the value into the stream encoded using unsigned LEB128 at the 71 /// current file position. 72 /// 73 /// \param Value The value to write into the stream. 74 void writeULEB(uint64_t Value); 75 76 /// Write an array of uint8_t values into the stream at the current file 77 /// position. 78 /// 79 /// \param Data An array of values to write into the stream. 80 void writeData(llvm::ArrayRef<uint8_t> Data); 81 82 /// Write a NULL terminated C string into the stream at the current file 83 /// position. The entire contents of Str will be written into the steam at 84 /// the current file position and then an extra NULL termation byte will be 85 /// written. It is up to the user to ensure that Str doesn't contain any NULL 86 /// characters unless the additional NULL characters are desired. 87 /// 88 /// \param Str The value to write into the stream. 89 void writeNullTerminated(llvm::StringRef Str); 90 91 /// Fixup a uint32_t value at the specified offset in the stream. This 92 /// function will save the current file position, seek to the specified 93 /// offset, overwrite the data using Value, and then restore the file 94 /// position to the previous file position. 95 /// 96 /// \param Value The value to write into the stream. 97 /// \param Offset The offset at which to write the Value within the stream. 98 void fixup32(uint32_t Value, uint64_t Offset); 99 100 /// Pad with zeroes at the current file position until the current file 101 /// position matches the specified alignment. 102 /// 103 /// \param Align An integer speciying the desired alignment. This does not 104 /// need to be a power of two. 105 void alignTo(size_t Align); 106 107 /// Return the current offset within the file. 108 /// 109 /// \return The unsigned offset from the start of the file of the current 110 /// file position. 111 uint64_t tell(); 112 113 llvm::raw_pwrite_stream &get_stream() { 114 return OS; 115 } 116 117 llvm::endianness getByteOrder() const { return ByteOrder; } 118 119 private: 120 FileWriter(const FileWriter &rhs) = delete; 121 void operator=(const FileWriter &rhs) = delete; 122 }; 123 124 } // namespace gsym 125 } // namespace llvm 126 127 #endif // LLVM_DEBUGINFO_GSYM_FILEWRITER_H 128