Get DragonDB to compile with clang.

While at it, fix some compile warnings, 2 of them are actual bugs
(missing virtual d'tor).

Signed-off-by: chakaz <chakaz@chakaz>

.gitignore

@@ -1,5 +1,7 @@
 build/*
 build-*
+clang/*
+clang-*
 .vscode/*.db
 .vscode/settings.json
 third_party

src/facade/reply_builder_test.cc

@@ -172,7 +172,6 @@ RedisReplyBuilderTest::ParsingResults RedisReplyBuilderTest::Parse() {
   auto* ptr = parser_buffer_.get();
   memcpy(ptr, str().data(), SinkSize());
   RedisParser parser(false);  // client side
-  std::string_view tmp_view{str()};
   result.result =
       parser.Parse(RedisParser::Buffer{ptr, SinkSize()}, &result.consumed, &result.args);
   return result;

src/server/db_slice.cc

@@ -29,7 +29,6 @@ namespace {
 
 constexpr auto kPrimeSegmentSize = PrimeTable::kSegBytes;
 constexpr auto kExpireSegmentSize = ExpireTable::kSegBytes;
-constexpr auto kTaxSize = PrimeTable::kTaxAmount;
 
 // mi_malloc good size is 32768. i.e. we have malloc waste of 1.5%.
 static_assert(kPrimeSegmentSize == 32288);

src/server/dflycmd.cc

@@ -412,7 +412,7 @@ OpStatus DflyCmd::StartStableSyncInThread(FlowInfo* flow, Context* cntx, EngineS
   }
 
   // Register cleanup.
-  flow->cleanup = [this, flow]() {
+  flow->cleanup = [flow]() {
     flow->TryShutdownSocket();
     if (flow->streamer) {
       flow->streamer->Cancel();
@@ -626,7 +626,7 @@ void DflyCmd::Shutdown() {
 void DflyCmd::FlowInfo::TryShutdownSocket() {
   // Close socket for clean disconnect.
   if (conn->socket()->IsOpen()) {
-    conn->socket()->Shutdown(SHUT_RDWR);
+    (void)conn->socket()->Shutdown(SHUT_RDWR);
   }
 }
 

src/server/dragonfly_test.cc

@@ -38,13 +38,10 @@ constexpr unsigned kPoolThreadCount = 4;
 
 const char kKey1[] = "x";
 const char kKey2[] = "b";
-const char kKey3[] = "c";
-const char kKey4[] = "y";
 
 const char kKeySid0[] = "x";
 const char kKeySid1[] = "c";
 const char kKeySid2[] = "b";
-const char kKey2Sid0[] = "y";
 
 }  // namespace
 

src/server/memory_cmd.cc

@@ -69,7 +69,7 @@ std::string MallocStats(bool backing, unsigned tid) {
 
 }  // namespace
 
-MemoryCmd::MemoryCmd(ServerFamily* owner, ConnectionContext* cntx) : sf_(*owner), cntx_(cntx) {
+MemoryCmd::MemoryCmd(ServerFamily* owner, ConnectionContext* cntx) : cntx_(cntx) {
 }
 
 void MemoryCmd::Run(CmdArgList args) {

src/server/memory_cmd.h

@@ -17,7 +17,6 @@ class MemoryCmd {
   void Run(CmdArgList args);
 
  private:
-  ServerFamily& sf_;
   ConnectionContext* cntx_;
 };
 

src/server/rdb_load.cc

@@ -200,7 +200,7 @@ class DecompressImpl {
  public:
   DecompressImpl() : uncompressed_mem_buf_{16_KB} {
   }
-  ~DecompressImpl() {
+  virtual ~DecompressImpl() {
   }
   virtual io::Result<base::IoBuf*> Decompress(std::string_view str) = 0;
 
@@ -1955,7 +1955,6 @@ error_code RdbLoaderBase::HandleCompressedBlob(int op_type) {
   // Decompress blob and switch membuf pointer
   // Last type in the compressed blob is RDB_OPCODE_COMPRESSED_BLOB_END
   // in which we will switch back to the origin membuf (HandleCompressedBlobFinish)
-  string_view uncompressed_blob;
   SET_OR_RETURN(decompress_impl_->Decompress(res), mem_buf_);
 
   return kOk;

src/server/rdb_save.cc

@@ -148,7 +148,7 @@ class CompressorImpl {
   CompressorImpl() {
     compression_level_ = absl::GetFlag(FLAGS_compression_level);
   }
-  ~CompressorImpl() {
+  virtual ~CompressorImpl() {
     VLOG(1) << "compressed size: " << compressed_size_total_;
     VLOG(1) << "uncompressed size: " << uncompressed_size_total_;
   }
@@ -1241,7 +1241,7 @@ void RdbSerializer::AllocateCompressorOnce() {
 
 void RdbSerializer::CompressBlob() {
   if (!compression_stats_) {
-    compression_stats_.emplace();
+    compression_stats_.emplace(CompressionStats{});
   }
   Bytes blob_to_compress = mem_buf_.InputBuffer();
   size_t blob_size = blob_to_compress.size();

src/server/replica.h

@@ -26,7 +26,7 @@ namespace dfly {
 class Service;
 class ConnectionContext;
 class JournalExecutor;
-class JournalReader;
+struct JournalReader;
 
 class Replica {
  private:

src/server/server_family.cc

@@ -496,7 +496,7 @@ fibers::future<std::error_code> ServerFamily::Load(const std::string& load_path)
   // Check all paths are valid.
   for (const auto& path : paths) {
     error_code ec;
-    fs::canonical(path, ec);
+    (void)fs::canonical(path, ec);
     if (ec) {
       LOG(ERROR) << "Error loading " << load_path << " " << ec.message();
       fibers::promise<std::error_code> ec_promise;