[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

1 files changed, 19 insertions, 18 deletions

diff --git a/llvm/lib/IR/DebugInfoMetadata.cpp b/llvm/lib/IR/DebugInfoMetadata.cpp
index a777198d159..68b1d662815 100644
--- a/llvm/lib/IR/DebugInfoMetadata.cpp
+++ b/llvm/lib/IR/DebugInfoMetadata.cpp
@@ -394,34 +394,36 @@ DISubroutineType *DISubroutineType::getImpl(LLVMContext &Context, DIFlags Flags,
 
 // FIXME: Implement this string-enum correspondence with a .def file and macros,
 // so that the association is explicit rather than implied.
-static const char *ChecksumKindName[DIFile::CSK_Last + 1] = {
-  "CSK_None",
+static const char *ChecksumKindName[DIFile::CSK_Last] = {
   "CSK_MD5",
   "CSK_SHA1"
 };
 
-DIFile::ChecksumKind DIFile::getChecksumKind(StringRef CSKindStr) {
-  return StringSwitch<DIFile::ChecksumKind>(CSKindStr)
-      .Case("CSK_MD5", DIFile::CSK_MD5)
-      .Case("CSK_SHA1", DIFile::CSK_SHA1)
-      .Default(DIFile::CSK_None);
+StringRef DIFile::getChecksumKindAsString(ChecksumKind CSKind) {
+  assert(CSKind <= DIFile::CSK_Last && "Invalid checksum kind");
+  // The first space was originally the CSK_None variant, which is now
+  // obsolete, but the space is still reserved in ChecksumKind, so we account
+  // for it here.
+  return ChecksumKindName[CSKind - 1];
 }
 
-StringRef DIFile::getChecksumKindAsString() const {
-  assert(CSKind <= DIFile::CSK_Last && "Invalid checksum kind");
-  return ChecksumKindName[CSKind];
+Optional<DIFile::ChecksumKind> DIFile::getChecksumKind(StringRef CSKindStr) {
+  return StringSwitch<Optional<DIFile::ChecksumKind>>(CSKindStr)
+      .Case("CSK_MD5", DIFile::CSK_MD5)
+      .Case("CSK_SHA1", DIFile::CSK_SHA1)
+      .Default(None);
 }
 
 DIFile *DIFile::getImpl(LLVMContext &Context, MDString *Filename,
-                        MDString *Directory, DIFile::ChecksumKind CSKind,
-                        MDString *Checksum, StorageType Storage,
-                        bool ShouldCreate) {
+                        MDString *Directory,
+                        Optional<DIFile::ChecksumInfo<MDString *>> CS,
+                        StorageType Storage, bool ShouldCreate) {
   assert(isCanonical(Filename) && "Expected canonical MDString");
   assert(isCanonical(Directory) && "Expected canonical MDString");
-  assert(isCanonical(Checksum) && "Expected canonical MDString");
-  DEFINE_GETIMPL_LOOKUP(DIFile, (Filename, Directory, CSKind, Checksum));
-  Metadata *Ops[] = {Filename, Directory, Checksum};
-  DEFINE_GETIMPL_STORE(DIFile, (CSKind), Ops);
+  assert((!CS || isCanonical(CS->Value)) && "Expected canonical MDString");
+  DEFINE_GETIMPL_LOOKUP(DIFile, (Filename, Directory, CS));
+  Metadata *Ops[] = {Filename, Directory, CS ? CS->Value : nullptr};
+  DEFINE_GETIMPL_STORE(DIFile, (CS), Ops);
 }
 
 DICompileUnit *DICompileUnit::getImpl(
@@ -901,4 +903,3 @@ DIMacroFile *DIMacroFile::getImpl(LLVMContext &Context, unsigned MIType,
   Metadata *Ops[] = { File, Elements };
   DEFINE_GETIMPL_STORE(DIMacroFile, (MIType, Line), Ops);
 }
-