[XCOFF] Add functionality for parsing AIX XCOFF object file headers

Summary:
1. Add functionality for parsing AIX XCOFF object files headers.
2. Only support 32-bit AIX XCOFF object files in this patch.
3. Print out the AIX XCOFF object file header in YAML format.

Reviewers: sfertile, hubert.reinterpretcast, jasonliu, mstorsjo, zturner, rnk

Reviewed By: sfertile, hubert.reinterpretcast

Subscribers: jsji, mgorny, hiraditya, jdoerfert, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D59419

Patch by Digger Lin

llvm-svn: 357663

1 files changed, 7 insertions, 0 deletions

diff --git a/llvm/lib/BinaryFormat/Magic.cpp b/llvm/lib/BinaryFormat/Magic.cpp
index 85f944fa6ab..6063187a546 100644
--- a/llvm/lib/BinaryFormat/Magic.cpp
+++ b/llvm/lib/BinaryFormat/Magic.cpp
@@ -61,6 +61,13 @@ file_magic llvm::identify_magic(StringRef Magic) {
       return file_magic::wasm_object;
     break;
   }
+
+  case 0x01:
+    // XCOFF format
+    if (startswith(Magic, "\x01\xDF"))
+      return file_magic::xcoff_object_32;
+    break;
+
   case 0xDE: // 0x0B17C0DE = BC wraper
     if (startswith(Magic, "\xDE\xC0\x17\x0B"))
       return file_magic::bitcode;