[clangd] Enforce trailing slash for remote index's project root

[hokein]

clang-tools-extra/clangd/index/dex/dexp/Dexp.cpp

387 ↗

(On Diff #284597)

Instead of handling this in all callers, I think it might be better to move it to Marshaller and drop the ends-with-slash assertion there.

[kbobyrev]

Handle slash appending in Marshaller.

[kbobyrev]

Remove redundant .str() calls.

[kbobyrev]

Rebase.

clang-tools-extra/clangd/index/remote/Client.cpp

 
 public:
   IndexClient(
       std::shared_ptr<grpc::Channel> Channel, llvm::StringRef ProjectRoot,
       std::chrono::milliseconds DeadlineTime = std::chrono::milliseconds(1000))
       : Stub(remote::SymbolIndex::NewStub(Channel)),
         ProtobufMarshaller(new Marshaller(/*RemoteIndexRoot=*/"",
                                           /*LocalIndexRoot=*/ProjectRoot)),
-        DeadlineWaitingTime(DeadlineTime) {}
+        DeadlineWaitingTime(DeadlineTime) {
+    assert(!ProjectRoot.empty());
+  }
 
   void lookup(const clangd::LookupRequest &Request,
               llvm::function_ref<void(const clangd::Symbol &)> Callback) const {
     streamRPC(Request, &remote::SymbolIndex::Stub::Lookup, Callback);
   }
 
   bool
   fuzzyFind(const clangd::FuzzyFindRequest &Request,

clang-tools-extra/clangd/index/remote/marshalling/Marshalling.cpp

 
 Marshaller::Marshaller(llvm::StringRef RemoteIndexRoot,
                        llvm::StringRef LocalIndexRoot)
     : Strings(Arena) {
   if (!RemoteIndexRoot.empty()) {
     assert(llvm::sys::path::is_absolute(RemoteIndexRoot));
     assert(RemoteIndexRoot ==
            llvm::sys::path::convert_to_slash(RemoteIndexRoot));
-    assert(RemoteIndexRoot.endswith(llvm::sys::path::get_separator()));
     this->RemoteIndexRoot = RemoteIndexRoot.str();
+    if (!RemoteIndexRoot.endswith(llvm::sys::path::get_separator()))
+      *this->RemoteIndexRoot += llvm::sys::path::get_separator();
   }
   if (!LocalIndexRoot.empty()) {
     assert(llvm::sys::path::is_absolute(LocalIndexRoot));
     assert(LocalIndexRoot == llvm::sys::path::convert_to_slash(LocalIndexRoot));
-    assert(LocalIndexRoot.endswith(llvm::sys::path::get_separator()));
     this->LocalIndexRoot = LocalIndexRoot.str();
+    if (!LocalIndexRoot.endswith(llvm::sys::path::get_separator()))
+      *this->LocalIndexRoot += llvm::sys::path::get_separator();
   }
   assert(!RemoteIndexRoot.empty() || !LocalIndexRoot.empty());
 }
 
 llvm::Expected<clangd::LookupRequest>
 Marshaller::fromProtobuf(const LookupRequest *Message) {
   clangd::LookupRequest Req;
   auto IDs = getIDs(Message->ids());