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::support::endianness ByteOrder; 32 public: 33 FileWriter(llvm::raw_pwrite_stream &S, llvm::support::endianness B) 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. 79 void writeData(llvm::ArrayRef<uint8_t> Data); 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. 88 void writeNullTerminated(llvm::StringRef Str); 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(); 111 112 llvm::raw_pwrite_stream &get_stream() { 113 return OS; 114 } 115 116 llvm::support::endianness getByteOrder() const { return ByteOrder; } 117 118 private: 119 FileWriter(const FileWriter &rhs) = delete; 120 void operator=(const FileWriter &rhs) = delete; 121 }; 122 123 } // namespace gsym 124 } // namespace llvm 125 126 #endif // LLVM_DEBUGINFO_GSYM_FILEWRITER_H 127