Index: llvm/trunk/lib/ObjectYAML/ELFEmitter.cpp
===================================================================
--- llvm/trunk/lib/ObjectYAML/ELFEmitter.cpp
+++ llvm/trunk/lib/ObjectYAML/ELFEmitter.cpp
@@ -224,10 +224,10 @@
   Header.e_machine = Doc.Header.Machine;
   Header.e_version = EV_CURRENT;
   Header.e_entry = Doc.Header.Entry;
-  Header.e_phoff = sizeof(Header);
+  Header.e_phoff = Doc.ProgramHeaders.size() ? sizeof(Header) : 0;
   Header.e_flags = Doc.Header.Flags;
   Header.e_ehsize = sizeof(Elf_Ehdr);
-  Header.e_phentsize = sizeof(Elf_Phdr);
+  Header.e_phentsize = Doc.ProgramHeaders.size() ? sizeof(Elf_Phdr) : 0;
   Header.e_phnum = Doc.ProgramHeaders.size();
 
   Header.e_shentsize =
Index: llvm/trunk/test/tools/yaml2obj/elf-no-phdrs.yaml
===================================================================
--- llvm/trunk/test/tools/yaml2obj/elf-no-phdrs.yaml
+++ llvm/trunk/test/tools/yaml2obj/elf-no-phdrs.yaml
@@ -0,0 +1,15 @@
+## Check that e_phoff and e_phentsize are set to 0 when there are no
+## program headers.
+
+# RUN: yaml2obj %s -o %t
+# RUN: llvm-readobj --file-headers %t | FileCheck %s
+
+# CHECK: ProgramHeaderOffset: 0x0{{$}}
+# CHECK: ProgramHeaderEntrySize: 0{{$}}
+
+--- !ELF
+FileHeader:
+  Class:   ELFCLASS64
+  Data:    ELFDATA2LSB
+  Type:    ET_REL
+  Machine: EM_X86_64