[DebugInfo] Unify ChecksumKind and Checksum value in DIFile

Rather than encode the absence of a checksum with a Kind variant, instead put
both the kind and value in a struct and wrap it in an Optional.

Differential Revision: http://reviews.llvm.org/D43043

llvm-svn: 324928
diff --git a/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp
index 9e714e4..05c0001 100644
--- a/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp
@@ -165,14 +165,21 @@
   auto Insertion = FileIdMap.insert(std::make_pair(FullPath, NextId));
   if (Insertion.second) {
     // We have to compute the full filepath and emit a .cv_file directive.
-    std::string Checksum = fromHex(F->getChecksum());
-    void *CKMem = OS.getContext().allocate(Checksum.size(), 1);
-    memcpy(CKMem, Checksum.data(), Checksum.size());
-    ArrayRef<uint8_t> ChecksumAsBytes(reinterpret_cast<const uint8_t *>(CKMem),
-                                      Checksum.size());
-    DIFile::ChecksumKind ChecksumKind = F->getChecksumKind();
+    ArrayRef<uint8_t> ChecksumAsBytes;
+    FileChecksumKind CSKind = FileChecksumKind::None;
+    if (F->getChecksum()) {
+      std::string Checksum = fromHex(F->getChecksum()->Value);
+      void *CKMem = OS.getContext().allocate(Checksum.size(), 1);
+      memcpy(CKMem, Checksum.data(), Checksum.size());
+      ChecksumAsBytes = ArrayRef<uint8_t>(
+          reinterpret_cast<const uint8_t *>(CKMem), Checksum.size());
+      switch (F->getChecksum()->Kind) {
+      case DIFile::CSK_MD5:  CSKind = FileChecksumKind::MD5; break;
+      case DIFile::CSK_SHA1: CSKind = FileChecksumKind::SHA1; break;
+      }
+    }
     bool Success = OS.EmitCVFileDirective(NextId, FullPath, ChecksumAsBytes,
-                                          static_cast<unsigned>(ChecksumKind));
+                                          static_cast<unsigned>(CSKind));
     (void)Success;
     assert(Success && ".cv_file directive failed");
   }
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
index 939d13f..f799453 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
@@ -280,15 +280,16 @@
 
 MD5::MD5Result *DwarfUnit::getMD5AsBytes(const DIFile *File) {
   assert(File);
-  if (File->getChecksumKind() != DIFile::CSK_MD5)
+  Optional<DIFile::ChecksumInfo<StringRef>> Checksum = File->getChecksum();
+  if (!Checksum || Checksum->Kind != DIFile::CSK_MD5)
     return nullptr;
 
   // Convert the string checksum to an MD5Result for the streamer.
   // The verifier validates the checksum so we assume it's okay.
   // An MD5 checksum is 16 bytes.
-  std::string Checksum = fromHex(File->getChecksum());
+  std::string ChecksumString = fromHex(Checksum->Value);
   void *CKMem = Asm->OutStreamer->getContext().allocate(16, 1);
-  memcpy(CKMem, Checksum.data(), 16);
+  memcpy(CKMem, ChecksumString.data(), 16);
   return reinterpret_cast<MD5::MD5Result *>(CKMem);
 }