Comply with clang-tidy modernize-use-default-member-init (#266)

Author: garrisonhess

.clang-tidy

@@ -42,7 +42,6 @@ Checks:     '
             -google-readability-avoid-underscore-in-googletest-name,
             -modernize-avoid-c-arrays,
             -modernize-use-nodiscard,
-            -modernize-use-default-member-init,
             -modernize-use-trailing-return-type,
             -readability-convert-member-functions-to-static,
             -readability-identifier-length,

src/catalog/schema.cpp

@@ -18,7 +18,7 @@
 
 namespace bustub {
 
-Schema::Schema(const std::vector<Column> &columns) : tuple_is_inlined_(true) {
+Schema::Schema(const std::vector<Column> &columns) {
   uint32_t curr_offset = 0;
   for (uint32_t index = 0; index < columns.size(); index++) {
     Column column = columns[index];

src/include/catalog/schema.h

@@ -89,7 +89,7 @@ class Schema {
   std::vector<Column> columns_;
 
   /** True if all the columns are inlined, false otherwise. */
-  bool tuple_is_inlined_;
+  bool tuple_is_inlined_{true};
 
   /** Indices of all uninlined columns. */
   std::vector<uint32_t> uninlined_columns_;

src/include/concurrency/lock_manager.h

@@ -37,11 +37,11 @@ class LockManager {
 
   class LockRequest {
    public:
-    LockRequest(txn_id_t txn_id, LockMode lock_mode) : txn_id_(txn_id), lock_mode_(lock_mode), granted_(false) {}
+    LockRequest(txn_id_t txn_id, LockMode lock_mode) : txn_id_(txn_id), lock_mode_(lock_mode) {}
 
     txn_id_t txn_id_;
     LockMode lock_mode_;
-    bool granted_;
+    bool granted_{false};
   };
 
   class LockRequestQueue {

src/include/concurrency/transaction.h

@@ -155,8 +155,7 @@ class TransactionAbortException : public std::exception {
 class Transaction {
  public:
   explicit Transaction(txn_id_t txn_id, IsolationLevel isolation_level = IsolationLevel::REPEATABLE_READ)
-      : state_(TransactionState::GROWING),
-        isolation_level_(isolation_level),
+      : isolation_level_(isolation_level),
         thread_id_(std::this_thread::get_id()),
         txn_id_(txn_id),
         prev_lsn_(INVALID_LSN),
@@ -256,7 +255,7 @@ class Transaction {
 
  private:
   /** The current transaction state. */
-  TransactionState state_;
+  TransactionState state_{TransactionState::GROWING};
   /** The isolation level of the transaction. */
   IsolationLevel isolation_level_;
   /** The thread ID, used in single-threaded transactions. */

src/include/recovery/log_recovery.h

@@ -50,7 +50,7 @@ class LogRecovery {
   /** Mapping the log sequence number to log file offset for undos. */
   std::unordered_map<lsn_t, int> lsn_mapping_;
 
-  int offset_ __attribute__((__unused__));
+  int offset_ __attribute__((__unused__));  // NOLINT
   char *log_buffer_;
 };
 

src/include/storage/disk/disk_manager.h

@@ -97,10 +97,10 @@ class DiskManager {
   // stream to write db file
   std::fstream db_io_;
   std::string file_name_;
-  int num_flushes_;
-  int num_writes_;
-  bool flush_log_;
-  std::future<void> *flush_log_f_;
+  int num_flushes_{0};
+  int num_writes_{0};
+  bool flush_log_{false};
+  std::future<void> *flush_log_f_{nullptr};
   // With multiple buffer pool instances, need to protect file access
   std::mutex db_io_latch_;
 };

src/storage/disk/disk_manager.cpp

@@ -30,8 +30,7 @@ static char *buffer_used;
  * Constructor: open/create a single database file & log file
  * @input db_file: database file name
  */
-DiskManager::DiskManager(const std::string &db_file)
-    : file_name_(db_file), num_flushes_(0), num_writes_(0), flush_log_(false), flush_log_f_(nullptr) {
+DiskManager::DiskManager(const std::string &db_file) : file_name_(db_file) {
   std::string::size_type n = file_name_.rfind('.');
   if (n == std::string::npos) {
     LOG_DEBUG("wrong file format");