Move Object format code to lib/BinaryFormat.
This creates a new library called BinaryFormat that has all of
the headers from llvm/Support containing structure and layout
definitions for various types of binary formats like dwarf, coff,
elf, etc as well as the code for identifying a file from its
magic.
Differential Revision: https://reviews.llvm.org/D33843
llvm-svn: 304864
diff --git a/llvm/lib/BinaryFormat/Magic.cpp b/llvm/lib/BinaryFormat/Magic.cpp
new file mode 100644
index 0000000..ca4d93f
--- /dev/null
+++ b/llvm/lib/BinaryFormat/Magic.cpp
@@ -0,0 +1,216 @@
+//===- llvm/BinaryFormat/Magic.cpp - File magic identification --*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/BinaryFormat/Magic.h"
+
+#include "llvm/BinaryFormat/COFF.h"
+#include "llvm/BinaryFormat/ELF.h"
+#include "llvm/BinaryFormat/MachO.h"
+#include "llvm/Support/Endian.h"
+#include "llvm/Support/FileSystem.h"
+
+#if !defined(_MSC_VER) && !defined(__MINGW32__)
+#include <unistd.h>
+#else
+#include <io.h>
+#endif
+
+using namespace llvm;
+using namespace llvm::support::endian;
+using namespace llvm::sys::fs;
+
+template <size_t N>
+static bool startswith(StringRef Magic, const char (&S)[N]) {
+ return Magic.startswith(StringRef(S, N - 1));
+}
+
+/// @brief Identify the magic in magic.
+file_magic llvm::identify_magic(StringRef Magic) {
+ if (Magic.size() < 4)
+ return file_magic::unknown;
+ switch ((unsigned char)Magic[0]) {
+ case 0x00: {
+ // COFF bigobj, CL.exe's LTO object file, or short import library file
+ if (startswith(Magic, "\0\0\xFF\xFF")) {
+ size_t MinSize =
+ offsetof(COFF::BigObjHeader, UUID) + sizeof(COFF::BigObjMagic);
+ if (Magic.size() < MinSize)
+ return file_magic::coff_import_library;
+
+ const char *Start = Magic.data() + offsetof(COFF::BigObjHeader, UUID);
+ if (memcmp(Start, COFF::BigObjMagic, sizeof(COFF::BigObjMagic)) == 0)
+ return file_magic::coff_object;
+ if (memcmp(Start, COFF::ClGlObjMagic, sizeof(COFF::BigObjMagic)) == 0)
+ return file_magic::coff_cl_gl_object;
+ return file_magic::coff_import_library;
+ }
+ // Windows resource file
+ if (startswith(Magic, "\0\0\0\0\x20\0\0\0\xFF"))
+ return file_magic::windows_resource;
+ // 0x0000 = COFF unknown machine type
+ if (Magic[1] == 0)
+ return file_magic::coff_object;
+ if (startswith(Magic, "\0asm"))
+ return file_magic::wasm_object;
+ break;
+ }
+ case 0xDE: // 0x0B17C0DE = BC wraper
+ if (startswith(Magic, "\xDE\xC0\x17\x0B"))
+ return file_magic::bitcode;
+ break;
+ case 'B':
+ if (startswith(Magic, "BC\xC0\xDE"))
+ return file_magic::bitcode;
+ break;
+ case '!':
+ if (startswith(Magic, "!<arch>\n") || startswith(Magic, "!<thin>\n"))
+ return file_magic::archive;
+ break;
+
+ case '\177':
+ if (startswith(Magic, "\177ELF") && Magic.size() >= 18) {
+ bool Data2MSB = Magic[5] == 2;
+ unsigned high = Data2MSB ? 16 : 17;
+ unsigned low = Data2MSB ? 17 : 16;
+ if (Magic[high] == 0) {
+ switch (Magic[low]) {
+ default:
+ return file_magic::elf;
+ case 1:
+ return file_magic::elf_relocatable;
+ case 2:
+ return file_magic::elf_executable;
+ case 3:
+ return file_magic::elf_shared_object;
+ case 4:
+ return file_magic::elf_core;
+ }
+ }
+ // It's still some type of ELF file.
+ return file_magic::elf;
+ }
+ break;
+
+ case 0xCA:
+ if (startswith(Magic, "\xCA\xFE\xBA\xBE") ||
+ startswith(Magic, "\xCA\xFE\xBA\xBF")) {
+ // This is complicated by an overlap with Java class files.
+ // See the Mach-O section in /usr/share/file/magic for details.
+ if (Magic.size() >= 8 && Magic[7] < 43)
+ return file_magic::macho_universal_binary;
+ }
+ break;
+
+ // The two magic numbers for mach-o are:
+ // 0xfeedface - 32-bit mach-o
+ // 0xfeedfacf - 64-bit mach-o
+ case 0xFE:
+ case 0xCE:
+ case 0xCF: {
+ uint16_t type = 0;
+ if (startswith(Magic, "\xFE\xED\xFA\xCE") ||
+ startswith(Magic, "\xFE\xED\xFA\xCF")) {
+ /* Native endian */
+ size_t MinSize;
+ if (Magic[3] == char(0xCE))
+ MinSize = sizeof(MachO::mach_header);
+ else
+ MinSize = sizeof(MachO::mach_header_64);
+ if (Magic.size() >= MinSize)
+ type = Magic[12] << 24 | Magic[13] << 12 | Magic[14] << 8 | Magic[15];
+ } else if (startswith(Magic, "\xCE\xFA\xED\xFE") ||
+ startswith(Magic, "\xCF\xFA\xED\xFE")) {
+ /* Reverse endian */
+ size_t MinSize;
+ if (Magic[0] == char(0xCE))
+ MinSize = sizeof(MachO::mach_header);
+ else
+ MinSize = sizeof(MachO::mach_header_64);
+ if (Magic.size() >= MinSize)
+ type = Magic[15] << 24 | Magic[14] << 12 | Magic[13] << 8 | Magic[12];
+ }
+ switch (type) {
+ default:
+ break;
+ case 1:
+ return file_magic::macho_object;
+ case 2:
+ return file_magic::macho_executable;
+ case 3:
+ return file_magic::macho_fixed_virtual_memory_shared_lib;
+ case 4:
+ return file_magic::macho_core;
+ case 5:
+ return file_magic::macho_preload_executable;
+ case 6:
+ return file_magic::macho_dynamically_linked_shared_lib;
+ case 7:
+ return file_magic::macho_dynamic_linker;
+ case 8:
+ return file_magic::macho_bundle;
+ case 9:
+ return file_magic::macho_dynamically_linked_shared_lib_stub;
+ case 10:
+ return file_magic::macho_dsym_companion;
+ case 11:
+ return file_magic::macho_kext_bundle;
+ }
+ break;
+ }
+ case 0xF0: // PowerPC Windows
+ case 0x83: // Alpha 32-bit
+ case 0x84: // Alpha 64-bit
+ case 0x66: // MPS R4000 Windows
+ case 0x50: // mc68K
+ case 0x4c: // 80386 Windows
+ case 0xc4: // ARMNT Windows
+ if (Magic[1] == 0x01)
+ return file_magic::coff_object;
+ LLVM_FALLTHROUGH;
+
+ case 0x90: // PA-RISC Windows
+ case 0x68: // mc68K Windows
+ if (Magic[1] == 0x02)
+ return file_magic::coff_object;
+ break;
+
+ case 'M': // Possible MS-DOS stub on Windows PE file
+ if (startswith(Magic, "MZ")) {
+ uint32_t off = read32le(Magic.data() + 0x3c);
+ // PE/COFF file, either EXE or DLL.
+ if (off < Magic.size() &&
+ memcmp(Magic.data() + off, COFF::PEMagic, sizeof(COFF::PEMagic)) == 0)
+ return file_magic::pecoff_executable;
+ }
+ break;
+
+ case 0x64: // x86-64 Windows.
+ if (Magic[1] == char(0x86))
+ return file_magic::coff_object;
+ break;
+
+ default:
+ break;
+ }
+ return file_magic::unknown;
+}
+
+std::error_code llvm::identify_magic(const Twine &Path, file_magic &Result) {
+ int FD;
+ if (std::error_code EC = openFileForRead(Path, FD))
+ return EC;
+
+ char Buffer[32];
+ int Length = read(FD, Buffer, sizeof(Buffer));
+ if (close(FD) != 0 || Length < 0)
+ return std::error_code(errno, std::generic_category());
+
+ Result = identify_magic(StringRef(Buffer, Length));
+ return std::error_code();
+}