Fix modernize-use-auto warning reported by clang-tidy (#1111)

.clang-tidy

@@ -1,7 +1,7 @@
 # refer to https://clang.llvm.org/extra/clang-tidy/checks/list.html
 Checks: -*, clang-analyzer-core.*, clang-analyzer-cplusplus.*, clang-analyzer-deadcode.*, clang-analyzer-nullability.*, clang-analyzer-security.*, clang-analyzer-unix.*, clang-analyzer-valist.*, cppcoreguidelines-init-variables, cppcoreguidelines-macro-usage, cppcoreguidelines-interfaces-global-init, cppcoreguidelines-narrowing-conversions, cppcoreguidelines-no-malloc, cppcoreguidelines-prefer-member-initializer, cppcoreguidelines-special-member-functions, cppcoreguidelines-slicing, google-build-explicit-make-pair, google-default-arguments, google-explicit-constructor, modernize-avoid-bind, modernize-loop-convert, modernize-macro-to-enum, modernize-make-shared, modernize-make-unique, modernize-pass-by-value, modernize-redundant-void-arg, modernize-return-braced-init-list, modernize-use-auto, modernize-use-bool-literals, modernize-use-emplace, modernize-use-equals-default, modernize-use-equals-delete, modernize-use-nullptr, modernize-use-override, modernize-use-using, performance-faster-string-find, performance-for-range-copy, performance-implicit-conversion-in-loop, performance-inefficient-algorithm, performance-inefficient-vector-operation, performance-move-const-arg, performance-move-constructor-init, performance-no-automatic-move, performance-trivially-destructible, performance-type-promotion-in-math-fn, performance-unnecessary-copy-initialization, performance-unnecessary-value-param
 
-WarningsAsErrors: clang-analyzer-*, -clang-analyzer-security.insecureAPI.rand, cppcoreguidelines-interfaces-global-init, cppcoreguidelines-no-malloc, cppcoreguidelines-slicing, google-*, modernize-use-emplace, modernize-use-equals-default, modernize-use-equals-delete, performance-implicit-conversion-in-loop, performance-inefficient-algorithm, performance-move-constructor-init, performance-no-automatic-move, performance-trivially-destructible, performance-type-promotion-in-math-fn, performance-unnecessary-copy-initialization, modernize-use-bool-literals, performance-unnecessary-value-param, modernize-make-unique, performance-for-range-copy, performance-faster-string-find, modernize-redundant-void-arg, modernize-avoid-bind
+WarningsAsErrors: clang-analyzer-*, -clang-analyzer-security.insecureAPI.rand, cppcoreguidelines-interfaces-global-init, cppcoreguidelines-no-malloc, cppcoreguidelines-slicing, google-*, modernize-use-emplace, modernize-use-equals-default, modernize-use-equals-delete, performance-implicit-conversion-in-loop, performance-inefficient-algorithm, performance-move-constructor-init, performance-no-automatic-move, performance-trivially-destructible, performance-type-promotion-in-math-fn, performance-unnecessary-copy-initialization, modernize-use-bool-literals, performance-unnecessary-value-param, modernize-make-unique, performance-for-range-copy, performance-faster-string-find, modernize-redundant-void-arg, modernize-avoid-bind, modernize-use-auto
 
 CheckOptions:
   - key:           cppcoreguidelines-special-member-functions.AllowSoleDefaultDtor

src/commands/redis_cmd.cc

@@ -4713,8 +4713,7 @@ class CommandFetchFile : public Commander {
         // Sleep if the speed of sending file is more than replication speed limit
         auto end = std::chrono::high_resolution_clock::now();
         uint64_t duration = std::chrono::duration_cast<std::chrono::microseconds>(end - start).count();
-        uint64_t shortest =
-            static_cast<uint64_t>(static_cast<double>(file_size) / max_replication_bytes * (1000 * 1000));
+        auto shortest = static_cast<uint64_t>(static_cast<double>(file_size) / max_replication_bytes * (1000 * 1000));
         if (max_replication_bytes > 0 && duration < shortest) {
           LOG(INFO) << "[replication] Need to sleep " << (shortest - duration) / 1000
                     << " ms since of sending files too quickly";

src/storage/batch_extractor.cc

@@ -70,7 +70,7 @@ rocksdb::Status WriteBatchExtractor::PutCF(uint32_t column_family_id, const Slic
         if (!parse_result) {
           return rocksdb::Status::InvalidArgument(parse_result.Msg());
         }
-        RedisCommand cmd = static_cast<RedisCommand>(*parse_result);
+        auto cmd = static_cast<RedisCommand>(*parse_result);
         if (cmd == kRedisCmdExpire) {
           command_args = {"EXPIREAT", user_key, std::to_string(metadata.expire)};
           resp_commands_[ns].emplace_back(Redis::Command2RESP(command_args));
@@ -103,7 +103,7 @@ rocksdb::Status WriteBatchExtractor::PutCF(uint32_t column_family_id, const Slic
         if (!parse_result) {
           return rocksdb::Status::InvalidArgument(parse_result.Msg());
         }
-        RedisCommand cmd = static_cast<RedisCommand>(*parse_result);
+        auto cmd = static_cast<RedisCommand>(*parse_result);
         switch (cmd) {
           case kRedisCmdLSet:
             if (args->size() < 2) {
@@ -149,7 +149,7 @@ rocksdb::Status WriteBatchExtractor::PutCF(uint32_t column_family_id, const Slic
         if (!parse_result) {
           return rocksdb::Status::InvalidArgument(parse_result.Msg());
         }
-        RedisCommand cmd = static_cast<RedisCommand>(*parse_result);
+        auto cmd = static_cast<RedisCommand>(*parse_result);
         switch (cmd) {
           case kRedisCmdSetBit: {
             if (args->size() < 2) {
@@ -240,7 +240,7 @@ rocksdb::Status WriteBatchExtractor::DeleteCF(uint32_t column_family_id, const S
         if (!parse_result) {
           return rocksdb::Status::InvalidArgument(parse_result.Msg());
         }
-        RedisCommand cmd = static_cast<RedisCommand>(*parse_result);
+        auto cmd = static_cast<RedisCommand>(*parse_result);
         switch (cmd) {
           case kRedisCmdLTrim:
             if (first_seen_) {

src/types/redis_bitmap.cc

@@ -247,8 +247,8 @@ rocksdb::Status Bitmap::BitCount(const Slice &user_key, int64_t start, int64_t s
   if (stop > static_cast<int64_t>(metadata.size)) stop = metadata.size;
   if (start < 0 || stop <= 0 || start >= stop) return rocksdb::Status::OK();
 
-  uint32_t u_start = static_cast<uint32_t>(start);
-  uint32_t u_stop = static_cast<uint32_t>(stop);
+  auto u_start = static_cast<uint32_t>(start);
+  auto u_stop = static_cast<uint32_t>(stop);
 
   LatestSnapShot ss(db_);
   rocksdb::ReadOptions read_options;
@@ -297,8 +297,8 @@ rocksdb::Status Bitmap::BitPos(const Slice &user_key, bool bit, int64_t start, i
     *pos = -1;
     return rocksdb::Status::OK();
   }
-  uint32_t u_start = static_cast<uint32_t>(start);
-  uint32_t u_stop = static_cast<uint32_t>(stop);
+  auto u_start = static_cast<uint32_t>(start);
+  auto u_stop = static_cast<uint32_t>(stop);
 
   auto bitPosInByte = [](char byte, bool bit) -> int {
     for (int i = 0; i < 8; i++) {
@@ -430,7 +430,7 @@ rocksdb::Status Bitmap::BitOp(BitOpFlags op_flag, const std::string &op_name, co
 
 #ifndef USE_ALIGNED_ACCESS
         if (frag_minlen >= sizeof(uint64_t) * 4 && frag_numkeys <= 16) {
-          uint64_t *lres = reinterpret_cast<uint64_t *>(frag_res.get());
+          auto *lres = reinterpret_cast<uint64_t *>(frag_res.get());
           const uint64_t *lp[16];
           for (i = 0; i < frag_numkeys; i++) {
             lp[i] = reinterpret_cast<const uint64_t *>(fragments[i].data());