Support parsing fat MachO objects produced by Metal.

Author: maleadt

src/MachO/MachOHeader.jl

@@ -42,7 +42,7 @@ function macho_header_type(magic::UInt32)
         return MachOHeader32{MachOHandle}
     elseif magic in (MH_MAGIC_64, MH_CIGAM_64)
         return MachOHeader64{MachOHandle}
-    elseif magic in (FAT_MAGIC, FAT_CIGAM, FAT_MAGIC_64, FAT_CIGAM_64)
+    elseif magic in (FAT_MAGIC, FAT_CIGAM, FAT_MAGIC_64, FAT_CIGAM_64, FAT_MAGIC_METAL, FAT_CIGAM_METAL)
         return MachOFatHeader{MachOHandle}
     else
         throw(MagicMismatch("Invalid Magic ($(string(magic, base=16)))!"))
@@ -58,7 +58,7 @@ Mach-O header.
 function macho_is64bit(magic::UInt32)
     if magic in (MH_MAGIC_64, MH_CIGAM_64, FAT_MAGIC_64, FAT_CIGAM_64)
         return true
-    elseif magic in (MH_MAGIC, MH_CIGAM, FAT_MAGIC, FAT_CIGAM)
+    elseif magic in (MH_MAGIC, MH_CIGAM, FAT_MAGIC, FAT_CIGAM, FAT_MAGIC_METAL, FAT_CIGAM_METAL)
         return false
     else
         throw(MagicMismatch("Invalid Magic ($(string(magic, base=16)))!"))
@@ -72,9 +72,9 @@ Given the `magic` field from a Mach-O file header, return the endianness of the
 Mach-O header.
 """
 function macho_endianness(magic::UInt32)
-    if magic in (MH_CIGAM, MH_CIGAM_64, FAT_CIGAM)
+    if magic in (MH_CIGAM, MH_CIGAM_64, FAT_CIGAM, FAT_CIGAM_METAL)
         return :BigEndian
-    elseif magic in (MH_MAGIC, MH_MAGIC_64, FAT_MAGIC)
+    elseif magic in (MH_MAGIC, MH_MAGIC_64, FAT_MAGIC, FAT_MAGIC_METAL)
         return :LittleEndian
     else
         throw(MagicMismatch("Invalid Magic ($(string(magic, base=16)))!"))

src/MachO/constants.jl

@@ -11,6 +11,9 @@
 
     const FAT_MAGIC_64 = 0xCAFEBABF
     const FAT_CIGAM_64 = bswap(FAT_MAGIC_64)
+
+    const FAT_MAGIC_METAL = 0xCBFEBABE
+    const FAT_CIGAM_METAL = bswap(FAT_MAGIC_METAL)
 end
 
 const CPU_ARCH_MASK     = 0xff000000