NFC: Move API uses of MD5::MD5Result to Optional

[echristo]

Summary

The other half of most of this API is Optional and it's literally... optional, so let's make it so.

[dblaikie]

Looks good to me (:

llvm/lib/MC/MCDwarf.cpp

364 ↗

(On Diff #193802)

You can write this as "*DwarfFile.Checksum" rather than "DwarfFile.Checksum.getValue()" if you like. (I tend to prefer that)

[echristo]

llvm/lib/MC/MCDwarf.cpp

364 ↗

(On Diff #193802)

SGTM. :)

llvm/trunk/include/llvm/MC/MCContext.h

public:
     const std::string &getMainFileName() const { return MainFileName; }
 
     /// Set the main file name and override the default.
     void setMainFileName(StringRef S) { MainFileName = S; }
 
     /// Creates an entry in the dwarf file and directory tables.
     Expected<unsigned> getDwarfFile(StringRef Directory, StringRef FileName,
                                     unsigned FileNumber,
-                                    MD5::MD5Result *Checksum,
+                                    Optional<MD5::MD5Result> Checksum,
                                     Optional<StringRef> Source, unsigned CUID);
 
     bool isValidDwarfFileNumber(unsigned FileNumber, unsigned CUID = 0);
 
     const std::map<unsigned, MCDwarfLineTable> &getMCDwarfLineTables() const {
       return MCDwarfLineTablesCUMap;
     }
 
public:
 
     void setDwarfCompileUnitID(unsigned CUIndex) {
       DwarfCompileUnitID = CUIndex;
     }
 
     /// Specifies the "root" file and directory of the compilation unit.
     /// These are "file 0" and "directory 0" in DWARF v5.
     void setMCLineTableRootFile(unsigned CUID, StringRef CompilationDir,
-                                StringRef Filename, MD5::MD5Result *Checksum,
+                                StringRef Filename,
+                                Optional<MD5::MD5Result> Checksum,
                                 Optional<StringRef> Source) {
       getMCDwarfLineTable(CUID).setRootFile(CompilationDir, Filename, Checksum,
                                             Source);
     }
 
     /// Reports whether MD5 checksum usage is consistent (all-or-none).
     bool isDwarfMD5UsageConsistent(unsigned CUID) const {
       return getMCDwarfLineTable(CUID).isMD5UsageConsistent();

llvm/trunk/include/llvm/MC/MCDwarf.h

struct MCDwarfFile {
   // The base name of the file without its directory path.
   std::string Name;
 
   // The index into the list of directory names for this file name.
   unsigned DirIndex;
 
   /// The MD5 checksum, if there is one. Non-owning pointer to data allocated
   /// in MCContext.
-  MD5::MD5Result *Checksum = nullptr;
+  Optional<MD5::MD5Result> Checksum;
 
   /// The source code of the file. Non-owning reference to data allocated in
   /// MCContext.
   Optional<StringRef> Source;
 };
 
 /// Instances of this class represent the information from a
 /// dwarf .loc directive.

 private:
   bool HasAllMD5 = true;
   bool HasAnyMD5 = false;
 
 public:
   MCDwarfLineTableHeader() = default;
 
   Expected<unsigned> tryGetFile(StringRef &Directory, StringRef &FileName,
-                                MD5::MD5Result *Checksum,
+                                Optional<MD5::MD5Result> Checksum,
                                 Optional<StringRef> &Source,
                                 unsigned FileNumber = 0);
   std::pair<MCSymbol *, MCSymbol *>
   Emit(MCStreamer *MCOS, MCDwarfLineTableParams Params,
        Optional<MCDwarfLineStr> &LineStr) const;
   std::pair<MCSymbol *, MCSymbol *>
   Emit(MCStreamer *MCOS, MCDwarfLineTableParams Params,
        ArrayRef<char> SpecialOpcodeLengths,
void emitV5FileDirTables(MCStreamer *MCOS, Optional<MCDwarfLineStr> &LineStr,
                            StringRef CtxCompilationDir) const;
 };
 
 class MCDwarfDwoLineTable {
   MCDwarfLineTableHeader Header;
 
 public:
   void maybeSetRootFile(StringRef Directory, StringRef FileName,
-                        MD5::MD5Result *Checksum, Optional<StringRef> Source) {
+                        Optional<MD5::MD5Result> Checksum, Optional<StringRef> Source) {
     if (!Header.RootFile.Name.empty())
       return;
     Header.CompilationDir = Directory;
     Header.RootFile.Name = FileName;
     Header.RootFile.DirIndex = 0;
     Header.RootFile.Checksum = Checksum;
     Header.RootFile.Source = Source;
-    Header.trackMD5Usage(Checksum);
+    Header.trackMD5Usage(Checksum.hasValue());
     Header.HasSource = Source.hasValue();
   }
 
   unsigned getFile(StringRef Directory, StringRef FileName,
-                   MD5::MD5Result *Checksum, Optional<StringRef> Source) {
+                   Optional<MD5::MD5Result> Checksum, Optional<StringRef> Source) {
     return cantFail(Header.tryGetFile(Directory, FileName, Checksum, Source));
   }
 
   void Emit(MCStreamer &MCOS, MCDwarfLineTableParams Params,
             MCSection *Section) const;
 };
 
 class MCDwarfLineTable {
   MCDwarfLineTableHeader Header;
   MCLineSection MCLineSections;
 
 public:
   // This emits the Dwarf file and the line tables for all Compile Units.
   static void Emit(MCObjectStreamer *MCOS, MCDwarfLineTableParams Params);
 
   // This emits the Dwarf file and the line tables for a given Compile Unit.
   void EmitCU(MCObjectStreamer *MCOS, MCDwarfLineTableParams Params,
               Optional<MCDwarfLineStr> &LineStr) const;
 
   Expected<unsigned> tryGetFile(StringRef &Directory, StringRef &FileName,
-                                MD5::MD5Result *Checksum,
+                                Optional<MD5::MD5Result> Checksum,
                                 Optional<StringRef> Source,
                                 unsigned FileNumber = 0);
   unsigned getFile(StringRef &Directory, StringRef &FileName,
-                   MD5::MD5Result *Checksum, Optional<StringRef> &Source,
+                   Optional<MD5::MD5Result> Checksum, Optional<StringRef> &Source,
                    unsigned FileNumber = 0) {
     return cantFail(tryGetFile(Directory, FileName, Checksum, Source,
                                FileNumber));
   }
 
   void setRootFile(StringRef Directory, StringRef FileName,
-                   MD5::MD5Result *Checksum, Optional<StringRef> Source) {
+                   Optional<MD5::MD5Result> Checksum, Optional<StringRef> Source) {
     Header.CompilationDir = Directory;
     Header.RootFile.Name = FileName;
     Header.RootFile.DirIndex = 0;
     Header.RootFile.Checksum = Checksum;
     Header.RootFile.Source = Source;
-    Header.trackMD5Usage(Checksum);
+    Header.trackMD5Usage(Checksum.hasValue());
     Header.HasSource = Source.hasValue();
   }
 
   void resetRootFile() {
     assert(Header.MCDwarfFiles.empty());
     Header.RootFile.Name.clear();
     Header.resetMD5Usage();
     Header.HasSource = false;

llvm/trunk/include/llvm/MC/MCStreamer.h

public:
   /// Emit the "identifiers" directive.  This implements the
   /// '.ident "version foo"' assembler directive.
   virtual void EmitIdent(StringRef IdentString) {}
 
   /// Associate a filename with a specified logical file number.  This
   /// implements the DWARF2 '.file 4 "foo.c"' assembler directive.
   unsigned EmitDwarfFileDirective(unsigned FileNo, StringRef Directory,
                                   StringRef Filename,
-                                  MD5::MD5Result *Checksum = nullptr,
+                                  Optional<MD5::MD5Result> Checksum = None,
                                   Optional<StringRef> Source = None,
                                   unsigned CUID = 0) {
     return cantFail(
         tryEmitDwarfFileDirective(FileNo, Directory, Filename, Checksum,
                                   Source, CUID));
   }
 
   /// Associate a filename with a specified logical file number.
   /// Also associate a directory, optional checksum, and optional source
   /// text with the logical file.  This implements the DWARF2
   /// '.file 4 "dir/foo.c"' assembler directive, and the DWARF5
   /// '.file 4 "dir/foo.c" md5 "..." source "..."' assembler directive.
   virtual Expected<unsigned> tryEmitDwarfFileDirective(
       unsigned FileNo, StringRef Directory, StringRef Filename,
-      MD5::MD5Result *Checksum = nullptr, Optional<StringRef> Source = None,
+      Optional<MD5::MD5Result> Checksum = None, Optional<StringRef> Source = None,
       unsigned CUID = 0);
 
   /// Specify the "root" file of the compilation, using the ".file 0" extension.
   virtual void emitDwarfFile0Directive(StringRef Directory, StringRef Filename,
-                                       MD5::MD5Result *Checksum,
+                                       Optional<MD5::MD5Result> Checksum,
                                        Optional<StringRef> Source,
                                        unsigned CUID = 0);
 
   virtual void EmitCFIBKeyFrame();
 
   /// This implements the DWARF2 '.loc fileno lineno ...' assembler
   /// directive.
   virtual void EmitDwarfLocDirective(unsigned FileNo, unsigned Line,

llvm/trunk/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp

 unsigned DwarfCompileUnit::getOrCreateSourceID(const DIFile *File) {
   // If we print assembly, we can't separate .file entries according to
   // compile units. Thus all files will belong to the default compile unit.
 
   // FIXME: add a better feature test than hasRawTextSupport. Even better,
   // extend .file to support this.
   unsigned CUID = Asm->OutStreamer->hasRawTextSupport() ? 0 : getUniqueID();
   if (!File)
-    return Asm->OutStreamer->EmitDwarfFileDirective(0, "", "", nullptr, None, CUID);
+    return Asm->OutStreamer->EmitDwarfFileDirective(0, "", "", None, None, CUID);
   return Asm->OutStreamer->EmitDwarfFileDirective(
       0, File->getDirectory(), File->getFilename(), getMD5AsBytes(File),
       File->getSource(), CUID);
 }
 
 DIE *DwarfCompileUnit::getOrCreateGlobalVariableDIE(
     const DIGlobalVariable *GV, ArrayRef<GlobalExpr> GlobalExprs) {
   // Check for pre-existence.

llvm/trunk/lib/CodeGen/AsmPrinter/DwarfUnit.h

public:
 
   /// Add a Dwarf section label attribute data and value.
   DIE::value_iterator addSectionLabel(DIE &Die, dwarf::Attribute Attribute,
                                       const MCSymbol *Label,
                                       const MCSymbol *Sec);
 
   /// If the \p File has an MD5 checksum, return it as an MD5Result
   /// allocated in the MCContext.
-  MD5::MD5Result *getMD5AsBytes(const DIFile *File) const;
+  Optional<MD5::MD5Result> getMD5AsBytes(const DIFile *File) const;
 
 protected:
   ~DwarfUnit();
 
   /// Create new static data member DIE.
   DIE *getOrCreateStaticMemberDIE(const DIDerivedType *DT);
 
   /// Look up the source ID for the given file. If none currently exists,

llvm/trunk/lib/CodeGen/AsmPrinter/DwarfUnit.cpp

 void DwarfUnit::addSectionOffset(DIE &Die, dwarf::Attribute Attribute,
                                  uint64_t Integer) {
   if (DD->getDwarfVersion() >= 4)
     addUInt(Die, Attribute, dwarf::DW_FORM_sec_offset, Integer);
   else
     addUInt(Die, Attribute, dwarf::DW_FORM_data4, Integer);
 }
 
-MD5::MD5Result *DwarfUnit::getMD5AsBytes(const DIFile *File) const {
+Optional<MD5::MD5Result> DwarfUnit::getMD5AsBytes(const DIFile *File) const {
   assert(File);
   if (DD->getDwarfVersion() < 5)
-    return nullptr;
+    return None;
   Optional<DIFile::ChecksumInfo<StringRef>> Checksum = File->getChecksum();
   if (!Checksum || Checksum->Kind != DIFile::CSK_MD5)
-    return nullptr;
+    return None;
 
   // 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 ChecksumString = fromHex(Checksum->Value);
-  void *CKMem = Asm->OutStreamer->getContext().allocate(16, 1);
-  memcpy(CKMem, ChecksumString.data(), 16);
-  return reinterpret_cast<MD5::MD5Result *>(CKMem);
+  MD5::MD5Result CKMem;
+  std::copy(ChecksumString.begin(), ChecksumString.end(), CKMem.Bytes.data());
+  return CKMem;
 }
 
 unsigned DwarfTypeUnit::getOrCreateSourceID(const DIFile *File) {
   if (!SplitLineTable)
     return getCU().getOrCreateSourceID(File);
   if (!UsedLineTable) {
     UsedLineTable = true;
     // This is a split type unit that needs a line table.

llvm/trunk/lib/MC/MCAsmStreamer.cpp

public:
   void emitValueToOffset(const MCExpr *Offset,
                          unsigned char Value,
                          SMLoc Loc) override;
 
   void EmitFileDirective(StringRef Filename) override;
   Expected<unsigned> tryEmitDwarfFileDirective(unsigned FileNo,
                                                StringRef Directory,
                                                StringRef Filename,
-                                               MD5::MD5Result *Checksum = 0,
+                                               Optional<MD5::MD5Result> Checksum = None,
                                                Optional<StringRef> Source = None,
                                                unsigned CUID = 0) override;
   void emitDwarfFile0Directive(StringRef Directory, StringRef Filename,
-                               MD5::MD5Result *Checksum,
+                               Optional<MD5::MD5Result> Checksum,
                                Optional<StringRef> Source,
                                unsigned CUID = 0) override;
   void EmitDwarfLocDirective(unsigned FileNo, unsigned Line,
                              unsigned Column, unsigned Flags,
                              unsigned Isa, unsigned Discriminator,
                              StringRef FileName) override;
   MCSymbol *getDwarfLineTableSymbol(unsigned CUID) override;
 
void MCAsmStreamer::EmitFileDirective(StringRef Filename) {
   assert(MAI->hasSingleParameterDotFile());
   OS << "\t.file\t";
   PrintQuotedString(Filename, OS);
   EmitEOL();
 }
 
 static void printDwarfFileDirective(unsigned FileNo, StringRef Directory,
                                     StringRef Filename,
-                                    MD5::MD5Result *Checksum,
+                                    Optional<MD5::MD5Result> Checksum,
                                     Optional<StringRef> Source,
                                     bool UseDwarfDirectory,
                                     raw_svector_ostream &OS) {
   SmallString<128> FullPathName;
 
   if (!UseDwarfDirectory && !Directory.empty()) {
     if (sys::path::is_absolute(Filename))
       Directory = "";
static void printDwarfFileDirective(unsigned FileNo, StringRef Directory,
   if (Source) {
     OS << " source ";
     PrintQuotedString(*Source, OS);
   }
 }
 
 Expected<unsigned> MCAsmStreamer::tryEmitDwarfFileDirective(
     unsigned FileNo, StringRef Directory, StringRef Filename,
-    MD5::MD5Result *Checksum, Optional<StringRef> Source, unsigned CUID) {
+    Optional<MD5::MD5Result> Checksum, Optional<StringRef> Source, unsigned CUID) {
   assert(CUID == 0 && "multiple CUs not supported by MCAsmStreamer");
 
   MCDwarfLineTable &Table = getContext().getMCDwarfLineTable(CUID);
   unsigned NumFiles = Table.getMCDwarfFiles().size();
   Expected<unsigned> FileNoOrErr =
       Table.tryGetFile(Directory, Filename, Checksum, Source, FileNo);
   if (!FileNoOrErr)
     return FileNoOrErr.takeError();
Expected<unsigned> MCAsmStreamer::tryEmitDwarfFileDirective(
   else
     EmitRawText(OS1.str());
 
   return FileNo;
 }
 
 void MCAsmStreamer::emitDwarfFile0Directive(StringRef Directory,
                                             StringRef Filename,
-                                            MD5::MD5Result *Checksum,
+                                            Optional<MD5::MD5Result> Checksum,
                                             Optional<StringRef> Source,
                                             unsigned CUID) {
   assert(CUID == 0);
   // .file 0 is new for DWARF v5.
   if (getContext().getDwarfVersion() < 5)
     return;
   // Inform MCDwarf about the root file.
   getContext().setMCLineTableRootFile(CUID, Directory, Filename, Checksum,

llvm/trunk/lib/MC/MCContext.cpp

 
 //===----------------------------------------------------------------------===//
 // Dwarf Management
 //===----------------------------------------------------------------------===//
 
 void MCContext::setGenDwarfRootFile(StringRef InputFileName, StringRef Buffer) {
   // MCDwarf needs the root file as well as the compilation directory.
   // If we find a '.file 0' directive that will supersede these values.
-  MD5::MD5Result *Cksum = nullptr;
+  Optional<MD5::MD5Result> Cksum;
   if (getDwarfVersion() >= 5) {
     MD5 Hash;
-    Cksum = (MD5::MD5Result *)allocate(sizeof(MD5::MD5Result), 1);
+    MD5::MD5Result Sum;
     Hash.update(Buffer);
-    Hash.final(*Cksum);
+    Hash.final(Sum);
+    Cksum = Sum;
   }
   // Canonicalize the root filename. It cannot be empty, and should not
   // repeat the compilation dir.
   StringRef FileName =
       !getMainFileName().empty() ? StringRef(getMainFileName()) : InputFileName;
   if (FileName.empty() || FileName == "-")
     FileName = "<stdin>";
   if (FileName.consume_front(getCompilationDir()))
     if (llvm::sys::path::is_separator(FileName.front()))
       FileName = FileName.drop_front();
   assert(!FileName.empty());
   setMCLineTableRootFile(
       /*CUID=*/0, getCompilationDir(), FileName, Cksum, None);
 }
 
 /// getDwarfFile - takes a file name and number to place in the dwarf file and
 /// directory tables.  If the file number has already been allocated it is an
 /// error and zero is returned and the client reports the error, else the
 /// allocated file number is returned.  The file numbers may be in any order.
 Expected<unsigned> MCContext::getDwarfFile(StringRef Directory,
                                            StringRef FileName,
                                            unsigned FileNumber,
-                                           MD5::MD5Result *Checksum,
+                                           Optional<MD5::MD5Result> Checksum,
                                            Optional<StringRef> Source,
                                            unsigned CUID) {
   MCDwarfLineTable &Table = MCDwarfLineTablesCUMap[CUID];
   return Table.tryGetFile(Directory, FileName, Checksum, Source, FileNumber);
 }
 
 /// isValidDwarfFileNumber - takes a dwarf file number and returns true if it
 /// currently is assigned and false otherwise.

llvm/trunk/lib/MC/MCDwarf.cpp

static void emitOneV5FileEntry(MCStreamer *MCOS, const MCDwarfFile &DwarfFile,
   if (LineStr)
     LineStr->emitRef(MCOS, DwarfFile.Name);
   else {
     MCOS->EmitBytes(DwarfFile.Name);     // FileName and...
     MCOS->EmitBytes(StringRef("\0", 1)); // its null terminator.
   }
   MCOS->EmitULEB128IntValue(DwarfFile.DirIndex); // Directory number.
   if (EmitMD5) {
-    MD5::MD5Result *Cksum = DwarfFile.Checksum;
+    const MD5::MD5Result &Cksum = *DwarfFile.Checksum;
     MCOS->EmitBinaryData(
-        StringRef(reinterpret_cast<const char *>(Cksum->Bytes.data()),
-                  Cksum->Bytes.size()));
+        StringRef(reinterpret_cast<const char *>(Cksum.Bytes.data()),
+                  Cksum.Bytes.size()));
   }
   if (HasSource) {
     if (LineStr)
       LineStr->emitRef(MCOS, DwarfFile.Source.getValueOr(StringRef()));
     else {
       MCOS->EmitBytes(
           DwarfFile.Source.getValueOr(StringRef())); // Source and...
       MCOS->EmitBytes(StringRef("\0", 1));           // its null terminator.
void MCDwarfLineTable::EmitCU(MCObjectStreamer *MCOS,
 
   // This is the end of the section, so set the value of the symbol at the end
   // of this section (that was used in a previous expression).
   MCOS->EmitLabel(LineEndSym);
 }
 
 Expected<unsigned> MCDwarfLineTable::tryGetFile(StringRef &Directory,
                                                 StringRef &FileName,
-                                                MD5::MD5Result *Checksum,
+                                                Optional<MD5::MD5Result> Checksum,
                                                 Optional<StringRef> Source,
                                                 unsigned FileNumber) {
   return Header.tryGetFile(Directory, FileName, Checksum, Source, FileNumber);
 }
 
 Expected<unsigned>
 MCDwarfLineTableHeader::tryGetFile(StringRef &Directory,
                                    StringRef &FileName,
-                                   MD5::MD5Result *Checksum,
+                                   Optional<MD5::MD5Result> Checksum,
                                    Optional<StringRef> &Source,
                                    unsigned FileNumber) {
   if (Directory == CompilationDir)
     Directory = "";
   if (FileName.empty()) {
     FileName = "<stdin>";
     Directory = "";
   }
   assert(!FileName.empty());
   // Keep track of whether any or all files have an MD5 checksum.
   // If any files have embedded source, they all must.
   if (MCDwarfFiles.empty()) {
-    trackMD5Usage(Checksum);
+    trackMD5Usage(Checksum.hasValue());
     HasSource = (Source != None);
   }
   if (FileNumber == 0) {
     // File numbers start with 1 and/or after any file numbers
     // allocated by inline-assembler .file directives.
     FileNumber = MCDwarfFiles.empty() ? 1 : MCDwarfFiles.size();
     SmallString<256> Buffer;
     auto IterBool = SourceIdMap.insert(
if (Directory.empty()) {
     // directory names are stored at MCDwarfDirs[DirIndex-1] where FileNames
     // are stored at MCDwarfFiles[FileNumber].Name .
     DirIndex++;
   }
 
   File.Name = FileName;
   File.DirIndex = DirIndex;
   File.Checksum = Checksum;
-  trackMD5Usage(Checksum);
+  trackMD5Usage(Checksum.hasValue());
   File.Source = Source;
   if (Source)
     HasSource = true;
 
   // return the allocated FileNumber.
   return FileNumber;
 }
 

llvm/trunk/lib/MC/MCParser/AsmParser.cpp

if (FileNumber == -1) {
     // In case there is a -g option as well as debug info from directive .file,
     // we turn off the -g option, directly use the existing debug info instead.
     // Also reset any implicit ".file 0" for the assembler source.
     if (Ctx.getGenDwarfForAssembly()) {
       Ctx.getMCDwarfLineTable(0).resetRootFile();
       Ctx.setGenDwarfForAssembly(false);
     }
 
-    MD5::MD5Result *CKMem = nullptr;
+    Optional<MD5::MD5Result> CKMem;
     if (HasMD5) {
-      CKMem = (MD5::MD5Result *)Ctx.allocate(sizeof(MD5::MD5Result), 1);
+      MD5::MD5Result Sum;
       for (unsigned i = 0; i != 8; ++i) {
-        CKMem->Bytes[i] = uint8_t(MD5Hi >> ((7 - i) * 8));
-        CKMem->Bytes[i + 8] = uint8_t(MD5Lo >> ((7 - i) * 8));
+        Sum.Bytes[i] = uint8_t(MD5Hi >> ((7 - i) * 8));
+        Sum.Bytes[i + 8] = uint8_t(MD5Lo >> ((7 - i) * 8));
       }
+      CKMem = Sum;
     }
     if (HasSource) {
       char *SourceBuf = static_cast<char *>(Ctx.allocate(SourceString.size()));
       memcpy(SourceBuf, SourceString.data(), SourceString.size());
       Source = StringRef(SourceBuf, SourceString.size());
     }
     if (FileNumber == 0) {
       if (Ctx.getDwarfVersion() < 5)

llvm/trunk/lib/MC/MCStreamer.cpp

 /// The implementation in this class just redirects to emitFill.
 void MCStreamer::EmitZeros(uint64_t NumBytes) {
   emitFill(NumBytes, 0);
 }
 
 Expected<unsigned>
 MCStreamer::tryEmitDwarfFileDirective(unsigned FileNo, StringRef Directory,
                                       StringRef Filename,
-                                      MD5::MD5Result *Checksum,
+                                      Optional<MD5::MD5Result> Checksum,
                                       Optional<StringRef> Source,
                                       unsigned CUID) {
   return getContext().getDwarfFile(Directory, Filename, FileNo, Checksum,
                                    Source, CUID);
 }
 
 void MCStreamer::emitDwarfFile0Directive(StringRef Directory,
                                          StringRef Filename,
-                                         MD5::MD5Result *Checksum,
+                                         Optional<MD5::MD5Result> Checksum,
                                          Optional<StringRef> Source,
                                          unsigned CUID) {
   getContext().setMCLineTableRootFile(CUID, Directory, Filename, Checksum,
                                       Source);
 }
 
 void MCStreamer::EmitCFIBKeyFrame() {
   MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();