1 //===- llvm/BinaryFormat/Magic.cpp - File magic identification --*- C++ -*-===//
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
7 //===----------------------------------------------------------------------===//
9 #include "llvm/BinaryFormat/Magic.h"
11 #include "llvm/BinaryFormat/COFF.h"
12 #include "llvm/BinaryFormat/ELF.h"
13 #include "llvm/BinaryFormat/MachO.h"
14 #include "llvm/Support/Endian.h"
15 #include "llvm/Support/FileSystem.h"
16 #include "llvm/Support/MemoryBuffer.h"
18 #if !defined(_MSC_VER) && !defined(__MINGW32__)
25 using namespace llvm::support::endian;
26 using namespace llvm::sys::fs;
29 static bool startswith(StringRef Magic, const char (&S)[N]) {
30 return Magic.startswith(StringRef(S, N - 1));
33 /// Identify the magic in magic.
34 file_magic llvm::identify_magic(StringRef Magic) {
36 return file_magic::unknown;
37 switch ((unsigned char)Magic[0]) {
39 // COFF bigobj, CL.exe's LTO object file, or short import library file
40 if (startswith(Magic, "\0\0\xFF\xFF")) {
42 offsetof(COFF::BigObjHeader, UUID) + sizeof(COFF::BigObjMagic);
43 if (Magic.size() < MinSize)
44 return file_magic::coff_import_library;
46 const char *Start = Magic.data() + offsetof(COFF::BigObjHeader, UUID);
47 if (memcmp(Start, COFF::BigObjMagic, sizeof(COFF::BigObjMagic)) == 0)
48 return file_magic::coff_object;
49 if (memcmp(Start, COFF::ClGlObjMagic, sizeof(COFF::BigObjMagic)) == 0)
50 return file_magic::coff_cl_gl_object;
51 return file_magic::coff_import_library;
53 // Windows resource file
54 if (Magic.size() >= sizeof(COFF::WinResMagic) &&
55 memcmp(Magic.data(), COFF::WinResMagic, sizeof(COFF::WinResMagic)) == 0)
56 return file_magic::windows_resource;
57 // 0x0000 = COFF unknown machine type
59 return file_magic::coff_object;
60 if (startswith(Magic, "\0asm"))
61 return file_magic::wasm_object;
67 if (startswith(Magic, "\x01\xDF"))
68 return file_magic::xcoff_object_32;
69 if (startswith(Magic, "\x01\xF7"))
70 return file_magic::xcoff_object_64;
73 case 0xDE: // 0x0B17C0DE = BC wraper
74 if (startswith(Magic, "\xDE\xC0\x17\x0B"))
75 return file_magic::bitcode;
78 if (startswith(Magic, "BC\xC0\xDE"))
79 return file_magic::bitcode;
82 if (startswith(Magic, "!<arch>\n") || startswith(Magic, "!<thin>\n"))
83 return file_magic::archive;
87 if (startswith(Magic, "\177ELF") && Magic.size() >= 18) {
88 bool Data2MSB = Magic[5] == 2;
89 unsigned high = Data2MSB ? 16 : 17;
90 unsigned low = Data2MSB ? 17 : 16;
91 if (Magic[high] == 0) {
94 return file_magic::elf;
96 return file_magic::elf_relocatable;
98 return file_magic::elf_executable;
100 return file_magic::elf_shared_object;
102 return file_magic::elf_core;
105 // It's still some type of ELF file.
106 return file_magic::elf;
111 if (startswith(Magic, "\xCA\xFE\xBA\xBE") ||
112 startswith(Magic, "\xCA\xFE\xBA\xBF")) {
113 // This is complicated by an overlap with Java class files.
114 // See the Mach-O section in /usr/share/file/magic for details.
115 if (Magic.size() >= 8 && Magic[7] < 43)
116 return file_magic::macho_universal_binary;
120 // The two magic numbers for mach-o are:
121 // 0xfeedface - 32-bit mach-o
122 // 0xfeedfacf - 64-bit mach-o
127 if (startswith(Magic, "\xFE\xED\xFA\xCE") ||
128 startswith(Magic, "\xFE\xED\xFA\xCF")) {
131 if (Magic[3] == char(0xCE))
132 MinSize = sizeof(MachO::mach_header);
134 MinSize = sizeof(MachO::mach_header_64);
135 if (Magic.size() >= MinSize)
136 type = Magic[12] << 24 | Magic[13] << 12 | Magic[14] << 8 | Magic[15];
137 } else if (startswith(Magic, "\xCE\xFA\xED\xFE") ||
138 startswith(Magic, "\xCF\xFA\xED\xFE")) {
141 if (Magic[0] == char(0xCE))
142 MinSize = sizeof(MachO::mach_header);
144 MinSize = sizeof(MachO::mach_header_64);
145 if (Magic.size() >= MinSize)
146 type = Magic[15] << 24 | Magic[14] << 12 | Magic[13] << 8 | Magic[12];
152 return file_magic::macho_object;
154 return file_magic::macho_executable;
156 return file_magic::macho_fixed_virtual_memory_shared_lib;
158 return file_magic::macho_core;
160 return file_magic::macho_preload_executable;
162 return file_magic::macho_dynamically_linked_shared_lib;
164 return file_magic::macho_dynamic_linker;
166 return file_magic::macho_bundle;
168 return file_magic::macho_dynamically_linked_shared_lib_stub;
170 return file_magic::macho_dsym_companion;
172 return file_magic::macho_kext_bundle;
176 case 0xF0: // PowerPC Windows
177 case 0x83: // Alpha 32-bit
178 case 0x84: // Alpha 64-bit
179 case 0x66: // MPS R4000 Windows
181 case 0x4c: // 80386 Windows
182 case 0xc4: // ARMNT Windows
183 if (Magic[1] == 0x01)
184 return file_magic::coff_object;
187 case 0x90: // PA-RISC Windows
188 case 0x68: // mc68K Windows
189 if (Magic[1] == 0x02)
190 return file_magic::coff_object;
193 case 'M': // Possible MS-DOS stub on Windows PE file, MSF/PDB file or a
195 if (startswith(Magic, "MZ") && Magic.size() >= 0x3c + 4) {
196 uint32_t off = read32le(Magic.data() + 0x3c);
197 // PE/COFF file, either EXE or DLL.
198 if (Magic.substr(off).startswith(
199 StringRef(COFF::PEMagic, sizeof(COFF::PEMagic))))
200 return file_magic::pecoff_executable;
202 if (Magic.startswith("Microsoft C/C++ MSF 7.00\r\n"))
203 return file_magic::pdb;
204 if (startswith(Magic, "MDMP"))
205 return file_magic::minidump;
208 case 0x64: // x86-64 or ARM64 Windows.
209 if (Magic[1] == char(0x86) || Magic[1] == char(0xaa))
210 return file_magic::coff_object;
213 case 0x2d: // YAML '-'
214 if (startswith(Magic, "--- !tapi") || startswith(Magic, "---\narchs:"))
215 return file_magic::tapi_file;
221 return file_magic::unknown;
224 std::error_code llvm::identify_magic(const Twine &Path, file_magic &Result) {
225 auto FileOrError = MemoryBuffer::getFile(Path, -1LL, false);
227 return FileOrError.getError();
229 std::unique_ptr<MemoryBuffer> FileBuffer = std::move(*FileOrError);
230 Result = identify_magic(FileBuffer->getBuffer());
232 return std::error_code();