[Object] Fix MachO's getUuid to return a pointer into the object instead of a danglin...

This works because uuid's are always little endian so it's not swapped.
Fixes use-after-return reported by asan.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220567 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Object/MachOObjectFile.cpp b/lib/Object/MachOObjectFile.cpp
index 0bd61cecb577d06f2ea5e8534ae370d358d31779..ad2fd03f9eeb60353e03a7c174d33ed09938a05b 100644 (file)
--- a/lib/Object/MachOObjectFile.cpp
+++ b/lib/Object/MachOObjectFile.cpp
@@ -2460,8 +2460,9 @@ ArrayRef<uint8_t> MachOObjectFile::getDyldInfoExportsTrie() const {
 ArrayRef<uint8_t> MachOObjectFile::getUuid() const {
   if (!UuidLoadCmd)
     return ArrayRef<uint8_t>();
-  MachO::uuid_command Uuid = getStruct<MachO::uuid_command>(this, UuidLoadCmd);
-  return ArrayRef<uint8_t>(Uuid.uuid, 16);
+  // Returning a pointer is fine as uuid doesn't need endian swapping.
+  const char *Ptr = UuidLoadCmd + offsetof(MachO::uuid_command, uuid);
+  return ArrayRef<uint8_t>(reinterpret_cast<const uint8_t *>(Ptr), 16);
 }
 
 StringRef MachOObjectFile::getStringTableData() const {