Index: llvm/trunk/lib/Object/IRObjectFile.cpp
===================================================================
--- llvm/trunk/lib/Object/IRObjectFile.cpp
+++ llvm/trunk/lib/Object/IRObjectFile.cpp
@@ -78,6 +78,8 @@
       StringRef SecContents;
       if (std::error_code EC = Sec.getContents(SecContents))
         return errorCodeToError(EC);
+      if (SecContents.size() <= 1)
+        return errorCodeToError(object_error::bitcode_section_not_found);
       return MemoryBufferRef(SecContents, Obj.getFileName());
     }
   }
Index: llvm/trunk/test/Object/nm-bitcode.test
===================================================================
--- llvm/trunk/test/Object/nm-bitcode.test
+++ llvm/trunk/test/Object/nm-bitcode.test
@@ -0,0 +1,12 @@
+# Inputs generated with:
+# echo 'int hello() { return 5; }' > test.c
+# clang -O -fembed-bitcode -c -o macho-bitcode-x86_64.o test.c
+# clang -O -fembed-bitcode-marker -c -o macho-bitcode-marker-x86_64.o test.c
+
+RUN: llvm-nm -a %p/Inputs/macho-bitcode-x86_64.o \
+RUN:         | FileCheck %s
+
+RUN: llvm-nm -a %p/Inputs/macho-bitcode-marker-x86_64.o \
+RUN:         | FileCheck %s
+
+CHECK: T _hello