Index: llvm/include/llvm/ObjectYAML/yaml2obj.h
===================================================================
--- llvm/include/llvm/ObjectYAML/yaml2obj.h
+++ llvm/include/llvm/ObjectYAML/yaml2obj.h
@@ -11,8 +11,17 @@
 #ifndef LLVM_TOOLS_YAML2OBJ_YAML2OBJ_H
 #define LLVM_TOOLS_YAML2OBJ_YAML2OBJ_H
 
+#include "llvm/ADT/StringRef.h"
+#include <memory>
+
 namespace llvm {
 class raw_ostream;
+template <typename T> class SmallVectorImpl;
+template <typename T> class Expected;
+
+namespace object {
+class ObjectFile;
+}
 
 namespace COFFYAML {
 struct Object;
@@ -33,13 +42,20 @@
 namespace yaml {
 class Input;
 struct YamlObjectFile;
-}
-}
 
-int yaml2coff(llvm::COFFYAML::Object &Doc, llvm::raw_ostream &Out);
-int yaml2elf(llvm::ELFYAML::Object &Doc, llvm::raw_ostream &Out);
-int yaml2macho(llvm::yaml::YamlObjectFile &Doc, llvm::raw_ostream &Out);
-int yaml2minidump(llvm::MinidumpYAML::Object &Doc, llvm::raw_ostream &Out);
-int yaml2wasm(llvm::WasmYAML::Object &Doc, llvm::raw_ostream &Out);
+int yaml2coff(COFFYAML::Object &Doc, raw_ostream &Out);
+int yaml2elf(ELFYAML::Object &Doc, raw_ostream &Out);
+int yaml2macho(YamlObjectFile &Doc, raw_ostream &Out);
+int yaml2minidump(MinidumpYAML::Object &Doc, raw_ostream &Out);
+int yaml2wasm(WasmYAML::Object &Doc, raw_ostream &Out);
+
+int convertYAML(Input &YIn, raw_ostream &Out, unsigned DocNum = 1);
+
+/// Convenience function for tests.
+Expected<std::unique_ptr<object::ObjectFile>>
+yaml2ObjectFile(SmallVectorImpl<char> &Storage, StringRef Yaml);
+
+} // namespace yaml
+} // namespace llvm
 
 #endif
Index: llvm/lib/ObjectYAML/CMakeLists.txt
===================================================================
--- llvm/lib/ObjectYAML/CMakeLists.txt
+++ llvm/lib/ObjectYAML/CMakeLists.txt
@@ -14,4 +14,10 @@
   WasmYAML.cpp
   XCOFFYAML.cpp
   YAML.cpp
+  yaml2coff.cpp
+  yaml2elf.cpp
+  yaml2macho.cpp
+  yaml2obj.cpp
+  yaml2minidump.cpp
+  yaml2wasm.cpp
   )
Index: llvm/lib/ObjectYAML/yaml2coff.cpp
===================================================================
--- llvm/lib/ObjectYAML/yaml2coff.cpp
+++ llvm/lib/ObjectYAML/yaml2coff.cpp
@@ -11,7 +11,6 @@
 ///
 //===----------------------------------------------------------------------===//
 
-#include "yaml2obj.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/ADT/StringMap.h"
@@ -20,6 +19,7 @@
 #include "llvm/DebugInfo/CodeView/StringsAndChecksums.h"
 #include "llvm/Object/COFF.h"
 #include "llvm/ObjectYAML/ObjectYAML.h"
+#include "llvm/ObjectYAML/yaml2obj.h"
 #include "llvm/Support/Endian.h"
 #include "llvm/Support/MemoryBuffer.h"
 #include "llvm/Support/SourceMgr.h"
@@ -592,7 +592,7 @@
   return true;
 }
 
-int yaml2coff(llvm::COFFYAML::Object &Doc, raw_ostream &Out) {
+int yaml::yaml2coff(llvm::COFFYAML::Object &Doc, raw_ostream &Out) {
   COFFParser CP(Doc);
   if (!CP.parse()) {
     errs() << "yaml2obj: Failed to parse YAML file!\n";
Index: llvm/lib/ObjectYAML/yaml2elf.cpp
===================================================================
--- llvm/lib/ObjectYAML/yaml2elf.cpp
+++ llvm/lib/ObjectYAML/yaml2elf.cpp
@@ -11,12 +11,12 @@
 ///
 //===----------------------------------------------------------------------===//
 
-#include "yaml2obj.h"
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/BinaryFormat/ELF.h"
 #include "llvm/MC/StringTableBuilder.h"
 #include "llvm/Object/ELFObjectFile.h"
 #include "llvm/ObjectYAML/ELFYAML.h"
+#include "llvm/ObjectYAML/yaml2obj.h"
 #include "llvm/ADT/StringSet.h"
 #include "llvm/Support/EndianStream.h"
 #include "llvm/Support/MemoryBuffer.h"
@@ -1077,7 +1077,7 @@
   return 0;
 }
 
-int yaml2elf(llvm::ELFYAML::Object &Doc, raw_ostream &Out) {
+int yaml::yaml2elf(llvm::ELFYAML::Object &Doc, raw_ostream &Out) {
   bool IsLE = Doc.Header.Data == ELFYAML::ELF_ELFDATA(ELF::ELFDATA2LSB);
   bool Is64Bit = Doc.Header.Class == ELFYAML::ELF_ELFCLASS(ELF::ELFCLASS64);
   if (Is64Bit) {
Index: llvm/lib/ObjectYAML/yaml2macho.cpp
===================================================================
--- llvm/lib/ObjectYAML/yaml2macho.cpp
+++ llvm/lib/ObjectYAML/yaml2macho.cpp
@@ -11,10 +11,10 @@
 ///
 //===----------------------------------------------------------------------===//
 
-#include "yaml2obj.h"
 #include "llvm/BinaryFormat/MachO.h"
 #include "llvm/ObjectYAML/DWARFEmitter.h"
 #include "llvm/ObjectYAML/ObjectYAML.h"
+#include "llvm/ObjectYAML/yaml2obj.h"
 #include "llvm/Support/Error.h"
 #include "llvm/Support/LEB128.h"
 #include "llvm/Support/YAMLTraits.h"
@@ -592,7 +592,7 @@
 
 } // end anonymous namespace
 
-int yaml2macho(yaml::YamlObjectFile &Doc, raw_ostream &Out) {
+int yaml::yaml2macho(yaml::YamlObjectFile &Doc, raw_ostream &Out) {
   UniversalWriter Writer(Doc);
   if (auto Err = Writer.writeMachO(Out)) {
     errs() << toString(std::move(Err));
Index: llvm/lib/ObjectYAML/yaml2minidump.cpp
===================================================================
--- llvm/lib/ObjectYAML/yaml2minidump.cpp
+++ llvm/lib/ObjectYAML/yaml2minidump.cpp
@@ -6,13 +6,13 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "yaml2obj.h"
 #include "llvm/ObjectYAML/MinidumpYAML.h"
+#include "llvm/ObjectYAML/yaml2obj.h"
 #include "llvm/Support/raw_ostream.h"
 
 using namespace llvm;
 
-int yaml2minidump(MinidumpYAML::Object &Doc, raw_ostream &Out) {
+int yaml::yaml2minidump(MinidumpYAML::Object &Doc, raw_ostream &Out) {
   writeAsBinary(Doc, Out);
   return 0;
 }
Index: llvm/lib/ObjectYAML/yaml2obj.cpp
===================================================================
--- /dev/null
+++ llvm/lib/ObjectYAML/yaml2obj.cpp
@@ -0,0 +1,64 @@
+//===-- yaml2obj.cpp ------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/ObjectYAML/yaml2obj.h"
+#include "llvm/ADT/StringExtras.h"
+#include "llvm/Object/ObjectFile.h"
+#include "llvm/ObjectYAML/ObjectYAML.h"
+#include "llvm/Support/Errc.h"
+#include "llvm/Support/YAMLTraits.h"
+
+namespace llvm {
+namespace yaml {
+
+LLVM_ATTRIBUTE_NORETURN static void error(Twine Message) {
+  errs() << Message << "\n";
+  exit(1);
+}
+
+int convertYAML(yaml::Input &YIn, raw_ostream &Out, unsigned DocNum) {
+  unsigned CurDocNum = 0;
+  do {
+    if (++CurDocNum == DocNum) {
+      yaml::YamlObjectFile Doc;
+      YIn >> Doc;
+      if (YIn.error())
+        error("yaml2obj: Failed to parse YAML file!");
+      if (Doc.Elf)
+        return yaml2elf(*Doc.Elf, Out);
+      if (Doc.Coff)
+        return yaml2coff(*Doc.Coff, Out);
+      if (Doc.MachO || Doc.FatMachO)
+        return yaml2macho(Doc, Out);
+      if (Doc.Minidump)
+        return yaml2minidump(*Doc.Minidump, Out);
+      if (Doc.Wasm)
+        return yaml2wasm(*Doc.Wasm, Out);
+      error("yaml2obj: Unknown document type!");
+    }
+  } while (YIn.nextDocument());
+
+  error("yaml2obj: Cannot find the " + Twine(DocNum) +
+        llvm::getOrdinalSuffix(DocNum) + " document");
+}
+
+Expected<std::unique_ptr<object::ObjectFile>>
+yaml2ObjectFile(SmallVectorImpl<char> &Storage, StringRef Yaml) {
+  Storage.clear();
+  raw_svector_ostream OS(Storage);
+
+  yaml::Input YIn(Yaml);
+  if (convertYAML(YIn, OS))
+    return createStringError(errc::invalid_argument, "Invalid YAML");
+
+  return object::ObjectFile::createObjectFile(
+      MemoryBufferRef(OS.str(), "YamlObject"));
+}
+
+} // namespace yaml
+} // namespace llvm
Index: llvm/lib/ObjectYAML/yaml2wasm.cpp
===================================================================
--- llvm/lib/ObjectYAML/yaml2wasm.cpp
+++ llvm/lib/ObjectYAML/yaml2wasm.cpp
@@ -14,6 +14,7 @@
 
 #include "llvm/Object/Wasm.h"
 #include "llvm/ObjectYAML/ObjectYAML.h"
+#include "llvm/ObjectYAML/yaml2obj.h"
 #include "llvm/Support/Endian.h"
 #include "llvm/Support/LEB128.h"
 
@@ -651,7 +652,7 @@
   return 0;
 }
 
-int yaml2wasm(llvm::WasmYAML::Object &Doc, raw_ostream &Out) {
+int llvm::yaml::yaml2wasm(WasmYAML::Object &Doc, raw_ostream &Out) {
   WasmWriter Writer(Doc);
 
   return Writer.writeWasm(Out);
Index: llvm/tools/yaml2obj/CMakeLists.txt
===================================================================
--- llvm/tools/yaml2obj/CMakeLists.txt
+++ llvm/tools/yaml2obj/CMakeLists.txt
@@ -8,9 +8,4 @@
 
 add_llvm_tool(yaml2obj
   yaml2obj.cpp
-  yaml2coff.cpp
-  yaml2elf.cpp
-  yaml2macho.cpp
-  yaml2minidump.cpp
-  yaml2wasm.cpp
   )
Index: llvm/tools/yaml2obj/yaml2obj.cpp
===================================================================
--- llvm/tools/yaml2obj/yaml2obj.cpp
+++ llvm/tools/yaml2obj/yaml2obj.cpp
@@ -13,9 +13,9 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "yaml2obj.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/ObjectYAML/ObjectYAML.h"
+#include "llvm/ObjectYAML/yaml2obj.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/InitLLVM.h"
@@ -42,32 +42,6 @@
   exit(1);
 }
 
-static int convertYAML(yaml::Input &YIn, raw_ostream &Out) {
-  unsigned CurDocNum = 0;
-  do {
-    if (++CurDocNum == DocNum) {
-      yaml::YamlObjectFile Doc;
-      YIn >> Doc;
-      if (YIn.error())
-        error("yaml2obj: Failed to parse YAML file!");
-      if (Doc.Elf)
-        return yaml2elf(*Doc.Elf, Out);
-      if (Doc.Coff)
-        return yaml2coff(*Doc.Coff, Out);
-      if (Doc.MachO || Doc.FatMachO)
-        return yaml2macho(Doc, Out);
-      if (Doc.Minidump)
-        return yaml2minidump(*Doc.Minidump, Out);
-      if (Doc.Wasm)
-        return yaml2wasm(*Doc.Wasm, Out);
-      error("yaml2obj: Unknown document type!");
-    }
-  } while (YIn.nextDocument());
-
-  error("yaml2obj: Cannot find the " + Twine(DocNum) +
-        llvm::getOrdinalSuffix(DocNum) + " document");
-}
-
 int main(int argc, char **argv) {
   InitLLVM X(argc, argv);
   cl::ParseCommandLineOptions(argc, argv);
@@ -87,7 +61,7 @@
     return 1;
 
   yaml::Input YIn(Buf.get()->getBuffer());
-  int Res = convertYAML(YIn, Out->os());
+  int Res = convertYAML(YIn, Out->os(), DocNum);
   if (Res == 0)
     Out->keep();
 
Index: llvm/unittests/ObjectYAML/CMakeLists.txt
===================================================================
--- llvm/unittests/ObjectYAML/CMakeLists.txt
+++ llvm/unittests/ObjectYAML/CMakeLists.txt
@@ -6,6 +6,7 @@
 add_llvm_unittest(ObjectYAMLTests
   MinidumpYAMLTest.cpp
   YAMLTest.cpp
+  yaml2ObjectFileTest.cpp
   )
 
 target_link_libraries(ObjectYAMLTests PRIVATE LLVMTestingSupport)
Index: llvm/unittests/ObjectYAML/yaml2ObjectFileTest.cpp
===================================================================
--- /dev/null
+++ llvm/unittests/ObjectYAML/yaml2ObjectFileTest.cpp
@@ -0,0 +1,36 @@
+//===- yaml2ObjectFileTest.cpp --------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/ADT/SmallString.h"
+#include "llvm/ObjectYAML/yaml2obj.h"
+#include "llvm/Object/ObjectFile.h"
+#include "llvm/Support/Error.h"
+#include "gtest/gtest.h"
+
+using namespace llvm;
+using namespace object;
+using namespace yaml;
+
+TEST(yaml2ObjectFile, ELF) {
+  SmallString<0> Storage;
+  Expected<std::unique_ptr<ObjectFile>> ErrOrObj
+    = yaml2ObjectFile(Storage, R"(
+--- !ELF
+FileHeader:
+  Class:    ELFCLASS64
+  Data:     ELFDATA2LSB
+  Type:     ET_REL
+  Machine:  EM_X86_64)");
+
+  ASSERT_TRUE(!!ErrOrObj);
+
+  std::unique_ptr<ObjectFile> ObjFile = std::move(ErrOrObj.get());
+
+  ASSERT_TRUE(ObjFile->isELF());
+  ASSERT_TRUE(ObjFile->isRelocatableObject());
+}