[clang] NFCI: Use DirectoryEntryRef in Module::Directory

[jansvoboda11]

Summary

This patch changes the type of Module::Directory from const DirectoryEntry * to (essentially) Optional<DirectoryEntryRef> in order to remove uses of the deprecated DirectoryEntry::getName().

Depends on D127651.

[bnbarham]

clang/include/clang/Basic/Module.h

152

Too many places to update I assume?

[bnbarham]

clang/lib/Lex/ModuleMap.cpp

184

Does a module always have a directory?

[jansvoboda11]

clang/include/clang/Basic/Module.h

152

Yes.

clang/lib/Lex/ModuleMap.cpp

184

No. Only a module we have read module map for. Module we only read from the PCM (and perhaps a standard C++ module) will not have a directory.

clang/include/clang/Basic/Module.h

public:
 
   /// The parent of this module. This will be NULL for the top-level
   /// module.
   Module *Parent;
 
   /// The build directory of this module. This is the directory in
   /// which the module is notionally built, and relative to which its headers
   /// are found.
-  const DirectoryEntry *Directory = nullptr;
+  OptionalDirectoryEntryRefDegradesToDirectoryEntryPtr Directory;
 
   /// The presumed file name for the module map defining this module.
   /// Only non-empty when building from preprocessed source.
   std::string PresumedModuleMapFile;
 
   /// The umbrella header or directory.
   llvm::PointerUnion<const FileEntryRef::MapEntry *,
                      const DirectoryEntryRef::MapEntry *>

clang/lib/Lex/ModuleMap.cpp

static void appendSubframeworkPaths(Module *Mod,
   for (StringRef Framework : llvm::drop_begin(llvm::reverse(Paths)))
     llvm::sys::path::append(Path, "Frameworks", Framework + ".framework");
 }
 
 OptionalFileEntryRef ModuleMap::findHeader(
     Module *M, const Module::UnresolvedHeaderDirective &Header,
     SmallVectorImpl<char> &RelativePathName, bool &NeedsFramework) {
   // Search for the header file within the module's home directory.
-  auto *Directory = M->Directory;
+  auto Directory = M->Directory;
   SmallString<128> FullPathName(Directory->getName());
 
   auto GetFile = [&](StringRef Filename) -> OptionalFileEntryRef {
     auto File =
         expectedToOptional(SourceMgr.getFileManager().getFileRef(Filename));
     if (!File || (Header.Size && File->getSize() != *Header.Size) ||
         (Header.ModTime && File->getModificationTime() != *Header.ModTime))
       return std::nullopt;