[PATCH] D66407: [llvm-objcopy][MachO] Implement -Ibinary

Mon Aug 26 01:34:17 PDT 2019

seiya marked 2 inline comments as done.
seiya added inline comments.

================
Comment at: llvm/test/tools/llvm-objcopy/MachO/binary-input.test:19
+X86-64-NEXT:  Arch: x86_64
+ARM64:        Format: Mach-O arm64
+ARM64-NEXT:   Arch: aarch64
----------------
Note that GNU objcopy sets MH_MAGIC instead of MH_MAGIC64 for aarch64:

```
$ gobjcopy -I binary -B aarch64 -O mach-o-arm64 foo.txt binary.arm64.o

$ llvm-readobj binary.arm64.o                                         
File: binary.arm64.o
Format: Mach-O 32-bit unknown         <- should be "Mach-O arm64"!
Arch: aarch64
AddressSize: 32bit

$ otool -h binary.arm64.o   
Mach header
      magic cputype cpusubtype  caps    filetype ncmds  ...
 0xfeedface 16777228          0  0x00           1     3    ...
```

I have no experience with aarch64 MachO objects, but AFAIK the magic should be MH_MAGIC64 ([[ https://github.com/llvm/llvm-project/blob/c52c74efdf43f35c7d1b9dcda309218b50573677/llvm/test/MC/MachO/AArch64/data-in-code.s#L18 | example ]]). I believe it's a bug in GNU objcopy...

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D66407/new/

https://reviews.llvm.org/D66407