[PATCH] Recognize 0x0000 as a COFF file magic.

[Rafael Espíndola]

LGTM.

On 14 November 2013 16:41, Rui Ueyama <ruiu at google.com> wrote:
>   - added a test using llvm-readobj.
>
> Hi Bigcheese,
>
> http://llvm-reviews.chandlerc.com/D2164
>
> CHANGE SINCE LAST DIFF
>   http://llvm-reviews.chandlerc.com/D2164?vs=5535&id=5552#toc
>
> Files:
>   lib/Support/Path.cpp
>   test/tools/llvm-readobj/Inputs/magic.coff-unknown
>   test/tools/llvm-readobj/file-headers.test
>   unittests/Support/Path.cpp
>
> Index: lib/Support/Path.cpp
> ===================================================================
> --- lib/Support/Path.cpp
> +++ lib/Support/Path.cpp
> @@ -853,6 +853,9 @@
>        if (Magic.size() >= sizeof(Expected) &&
>            memcmp(Magic.data(), Expected, sizeof(Expected)) == 0)
>          return file_magic::windows_resource;
> +      // 0x0000 = COFF unknown machine type
> +      if (Magic[1] == 0)
> +        return file_magic::coff_object;
>        break;
>      }
>      case 0xDE:  // 0x0B17C0DE = BC wraper
> Index: test/tools/llvm-readobj/file-headers.test
> ===================================================================
> --- test/tools/llvm-readobj/file-headers.test
> +++ test/tools/llvm-readobj/file-headers.test
> @@ -8,6 +8,8 @@
>  RUN:   | FileCheck %s -check-prefix ELF32
>  RUN: llvm-readobj -h %p/Inputs/trivial.obj.elf-x86-64 \
>  RUN:   | FileCheck %s -check-prefix ELF64
> +RUN: llvm-readobj -h %p/Inputs/magic.coff-unknown \
> +RUN:   | FileCheck %s -check-prefix COFF-UNKNOWN
>
>  COFF32:      File: {{(.*[/\\])?}}trivial.obj.coff-i386
>  COFF32-NEXT: Format: COFF-i386
> @@ -183,3 +185,17 @@
>  PE32-NEXT:     ReservedSize: 0x0
>  PE32-NEXT:   }
>  PE32-NEXT: }
> +
> +COFF-UNKNOWN:      Format: COFF-<unknown arch>
> +COFF-UNKNOWN-NEXT: Arch: unknown
> +COFF-UNKNOWN-NEXT: AddressSize: 32bit
> +COFF-UNKNOWN-NEXT: ImageFileHeader {
> +COFF-UNKNOWN-NEXT:   Machine: IMAGE_FILE_MACHINE_UNKNOWN (0x0)
> +COFF-UNKNOWN-NEXT:   SectionCount: 3
> +COFF-UNKNOWN-NEXT:   TimeDateStamp: 2013-11-14 21:19:28 (0x52853E60)
> +COFF-UNKNOWN-NEXT:   PointerToSymbolTable: 0xF8
> +COFF-UNKNOWN-NEXT:   SymbolCount: 11
> +COFF-UNKNOWN-NEXT:   OptionalHeaderSize: 0
> +COFF-UNKNOWN-NEXT:   Characteristics [ (0x0)
> +COFF-UNKNOWN-NEXT:   ]
> +COFF-UNKNOWN-NEXT: }
> Index: unittests/Support/Path.cpp
> ===================================================================
> --- unittests/Support/Path.cpp
> +++ unittests/Support/Path.cpp
> @@ -418,6 +418,7 @@
>
>  const char archive[] = "!<arch>\x0A";
>  const char bitcode[] = "\xde\xc0\x17\x0b";
> +const char coff_object[] = "\x00\x00";
>  const char elf_relocatable[] = { 0x7f, 'E', 'L', 'F', 1, 2, 1, 0, 0,
>                                   0,    0,   0,   0,   0, 0, 0, 0, 1 };
>  const char macho_universal_binary[] = "\xca\xfe\xba\xbe...\0x00";
> @@ -445,6 +446,7 @@
>      { #magic, magic, sizeof(magic), fs::file_magic::magic }
>      DEFINE(archive),
>      DEFINE(bitcode),
> +    DEFINE(coff_object),
>      DEFINE(elf_relocatable),
>      DEFINE(macho_universal_binary),
>      DEFINE(macho_object),