[TextAPI][elfabi] Make TBE handlers functions that return Errors

Since TBEHandler doesn't maintain state or otherwise have any need to be
a class right now, the read and write functions have been moved out and
turned into standalone functions. Additionally, the TBE read function
has been updated to return an Expected value for better error handling.
Tests have been updated to reflect these changes.

Differential Revision: https://reviews.llvm.org/D55450

llvm-svn: 348735

1 files changed, 5 insertions, 4 deletions

diff --git a/llvm/lib/TextAPI/ELF/TBEHandler.cpp b/llvm/lib/TextAPI/ELF/TBEHandler.cpp
index 846f80a8b5b..426e7bb86e3 100644
--- a/llvm/lib/TextAPI/ELF/TBEHandler.cpp
+++ b/llvm/lib/TextAPI/ELF/TBEHandler.cpp
@@ -142,16 +142,17 @@ template <> struct MappingTraits<ELFStub> {
 } // end namespace yaml
 } // end namespace llvm
 
-std::unique_ptr<ELFStub> TBEHandler::readFile(StringRef Buf) {
+Expected<std::unique_ptr<ELFStub>> elfabi::readTBEFromBuffer(StringRef Buf) {
   yaml::Input YamlIn(Buf);
   std::unique_ptr<ELFStub> Stub(new ELFStub());
   YamlIn >> *Stub;
-  if (YamlIn.error())
-    return nullptr;
+  if (std::error_code Err = YamlIn.error())
+    return createStringError(Err, "YAML failed reading as TBE");
+
   return Stub;
 }
 
-Error TBEHandler::writeFile(raw_ostream &OS, const ELFStub &Stub) {
+Error elfabi::writeTBEToOutputStream(raw_ostream &OS, const ELFStub &Stub) {
   yaml::Output YamlOut(OS, NULL, /*WrapColumn =*/0);
 
   YamlOut << const_cast<ELFStub &>(Stub);