Index: include/llvm/ObjectYAML/ELFYAML.h
===================================================================
--- include/llvm/ObjectYAML/ELFYAML.h
+++ include/llvm/ObjectYAML/ELFYAML.h
@@ -50,6 +50,7 @@
 LLVM_YAML_STRONG_TYPEDEF(uint8_t, ELF_RSS)
 // Just use 64, since it can hold 32-bit values too.
 LLVM_YAML_STRONG_TYPEDEF(uint64_t, ELF_SHF)
+LLVM_YAML_STRONG_TYPEDEF(uint32_t, ELF_SHN)
 LLVM_YAML_STRONG_TYPEDEF(uint8_t, ELF_STT)
 LLVM_YAML_STRONG_TYPEDEF(uint8_t, ELF_STV)
 LLVM_YAML_STRONG_TYPEDEF(uint8_t, ELF_STO)
@@ -89,6 +90,7 @@
   StringRef Name;
   ELF_STT Type;
   StringRef Section;
+  Optional<ELF_SHN> Index;
   llvm::yaml::Hex64 Value;
   llvm::yaml::Hex64 Size;
   uint8_t Other;
@@ -267,6 +269,10 @@
   static void bitset(IO &IO, ELFYAML::ELF_SHF &Value);
 };
 
+template <> struct ScalarEnumerationTraits<ELFYAML::ELF_SHN> {
+  static void enumeration(IO &IO, ELFYAML::ELF_SHN &Value);
+};
+
 template <>
 struct ScalarEnumerationTraits<ELFYAML::ELF_STT> {
   static void enumeration(IO &IO, ELFYAML::ELF_STT &Value);
@@ -334,6 +340,7 @@
 template <>
 struct MappingTraits<ELFYAML::Symbol> {
   static void mapping(IO &IO, ELFYAML::Symbol &Symbol);
+  static StringRef validate(IO &IO, ELFYAML::Symbol &Symbol);
 };
 
 template <>
Index: lib/ObjectYAML/ELFYAML.cpp
===================================================================
--- lib/ObjectYAML/ELFYAML.cpp
+++ lib/ObjectYAML/ELFYAML.cpp
@@ -477,6 +477,23 @@
 #undef BCase
 }
 
+void ScalarEnumerationTraits<ELFYAML::ELF_SHN>::enumeration(
+    IO &IO, ELFYAML::ELF_SHN &Value) {
+#define ECase(X) IO.enumCase(Value, #X, ELF::X)
+  ECase(SHN_UNDEF);
+  ECase(SHN_LORESERVE);
+  ECase(SHN_LOPROC);
+  ECase(SHN_HIPROC);
+  ECase(SHN_LOOS);
+  ECase(SHN_HIOS);
+  ECase(SHN_ABS);
+  ECase(SHN_COMMON);
+  ECase(SHN_XINDEX);
+  ECase(SHN_HIRESERVE);
+#undef ECase
+  IO.enumFallback<Hex32>(Value);
+}
+
 void ScalarEnumerationTraits<ELFYAML::ELF_STT>::enumeration(
     IO &IO, ELFYAML::ELF_STT &Value) {
 #define ECase(X) IO.enumCase(Value, #X, ELF::X)
@@ -701,6 +718,7 @@
   IO.mapOptional("Name", Symbol.Name, StringRef());
   IO.mapOptional("Type", Symbol.Type, ELFYAML::ELF_STT(0));
   IO.mapOptional("Section", Symbol.Section, StringRef());
+  IO.mapOptional("Index", Symbol.Index);
   IO.mapOptional("Value", Symbol.Value, Hex64(0));
   IO.mapOptional("Size", Symbol.Size, Hex64(0));
 
@@ -709,6 +727,13 @@
   IO.mapOptional("Other", Keys->Other, ELFYAML::ELF_STO(0));
 }
 
+StringRef MappingTraits<ELFYAML::Symbol>::validate(IO &IO, ELFYAML::Symbol &Symbol) {
+  if(Symbol.Index && Symbol.Section.data()) {
+    return "Index and Section cannot both be specified for Symbol";
+  }
+  return StringRef();
+}
+
 void MappingTraits<ELFYAML::LocalGlobalWeakSymbols>::mapping(
     IO &IO, ELFYAML::LocalGlobalWeakSymbols &Symbols) {
   IO.mapOptional("Local", Symbols.Local);
Index: tools/yaml2obj/yaml2elf.cpp
===================================================================
--- tools/yaml2obj/yaml2elf.cpp
+++ tools/yaml2obj/yaml2elf.cpp
@@ -409,7 +409,10 @@
         exit(1);
       }
       Symbol.st_shndx = Index;
-    } // else Symbol.st_shndex == SHN_UNDEF (== 0), since it was zero'd earlier.
+    } else if (Sym.Index) {
+      Symbol.st_shndx = *Sym.Index;
+    }
+    // else Symbol.st_shndex == SHN_UNDEF (== 0), since it was zero'd earlier.
     Symbol.st_value = Sym.Value;
     Symbol.st_other = Sym.Other;
     Symbol.st_size = Sym.Size;