Apply clang-tidy to remove empty constructors / destructors

This patch is the result of running run-clang-tidy -fix -header-filter=.* -checks='-*,modernize-use-equals-default' . Code style changes have been done on top. The result of this change leads to the following improvements: 1. Binary size reduction. * For a -DBUILD_CONFIG=mysql_release build, the binary size is reduced by ~400kb. * A raw -DCMAKE_BUILD_TYPE=Release reduces the binary size by ~1.4kb. 2. Compiler can better understand the intent of the code, thus it leads to more optimization possibilities. Additionally it enabled detecting unused variables that had an empty default constructor but not marked so explicitly. Particular change required following this patch in sql/opt_range.cc result_keys, an unused template class Bitmap now correctly issues unused variable warnings. Setting Bitmap template class constructor to default allows the compiler to identify that there are no side-effects when instantiating the class. Previously the compiler could not issue the warning as it assumed Bitmap class (being a template) would not be performing a NO-OP for its default constructor. This prevented the "unused variable warning".
MariaDB · Feb 9, 2023 · 08c8520 · 08c8520
1 parent 8dab661
commit 08c8520
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Showing 242 changed files with 1,101 additions and 1,341 deletions.
diff --git a/client/mysqlbinlog.cc b/client/mysqlbinlog.cc
@@ -303,8 +303,8 @@ class Load_log_processor
     }
 
 public:
-  Load_log_processor() {}
-  ~Load_log_processor() {}
+  Load_log_processor() = default;
+  ~Load_log_processor() = default;
 
   int init()
   {

diff --git a/include/ilist.h b/include/ilist.h
@@ -27,12 +27,11 @@
 // Derive your class from this struct to insert to a linked list.
 template <class Tag= void> struct ilist_node
 {
-  ilist_node() noexcept
 #ifndef DBUG_OFF
-      : next(NULL), prev(NULL)
+  ilist_node() noexcept : next(NULL), prev(NULL) {}
+#else
+  ilist_node() = default;
 #endif
-  {
-  }
 
   ilist_node(ilist_node *next, ilist_node *prev) noexcept
       : next(next), prev(prev)

diff --git a/include/my_atomic_wrapper.h b/include/my_atomic_wrapper.h
@@ -39,7 +39,7 @@ template <typename Type> class Atomic_relaxed
   Atomic_relaxed(const Atomic_relaxed<Type> &rhs)
   { m.store(rhs, std::memory_order_relaxed); }
   Atomic_relaxed(Type val) : m(val) {}
-  Atomic_relaxed() {}
+  Atomic_relaxed() = default;
 
   operator Type() const { return m.load(std::memory_order_relaxed); }
   Type operator=(const Type val)

diff --git a/include/my_counter.h b/include/my_counter.h
@@ -31,7 +31,7 @@ template <typename Type> class Atomic_counter
   Atomic_counter(const Atomic_counter<Type> &rhs)
   { m_counter.store(rhs, std::memory_order_relaxed); }
   Atomic_counter(Type val): m_counter(val) {}
-  Atomic_counter() {}
+  Atomic_counter() = default;
 
   Type operator++(int) { return add(1); }
   Type operator--(int) { return sub(1); }

diff --git a/include/span.h b/include/span.h
@@ -81,7 +81,7 @@ template <class ElementType> class span
 
   span(const span &other) : data_(other.data_), size_(other.size_) {}
 
-  ~span(){};
+  ~span() = default;
 
   span &operator=(const span &other)
   {

diff --git a/mysys_ssl/my_crypt.cc b/mysys_ssl/my_crypt.cc
@@ -104,7 +104,7 @@ class MyCTX_nopad : public MyCTX
   uchar oiv[MY_AES_BLOCK_SIZE];
 
   MyCTX_nopad() : MyCTX() { }
-  ~MyCTX_nopad() { }
+  ~MyCTX_nopad() = default;
 
   int init(const EVP_CIPHER *cipher, int encrypt, const uchar *key, uint klen,
            const uchar *iv, uint ivlen)

diff --git a/plugin/handler_socket/handlersocket/database.cpp b/plugin/handler_socket/handlersocket/database.cpp
@@ -189,9 +189,7 @@ database::database(const config& c)
 {
 }
 
-database::~database()
-{
-}
+database::~database() = default;
 
 dbcontext_ptr
 database::create_context(bool for_write) volatile
@@ -226,9 +224,7 @@ dbcontext::dbcontext(volatile database *d, bool for_write)
   user_level_lock_timeout = d->get_conf().get_int("wrlock_timeout", 12);
 }
 
-dbcontext::~dbcontext()
-{
-}
+dbcontext::~dbcontext() = default;
 
 namespace {
 

diff --git a/plugin/handler_socket/handlersocket/database.hpp b/plugin/handler_socket/handlersocket/database.hpp
@@ -27,7 +27,7 @@ struct dbcontext_i;
 typedef std::auto_ptr<dbcontext_i> dbcontext_ptr;
 
 struct database_i {
-  virtual ~database_i() { }
+  virtual ~database_i() = default;
   virtual dbcontext_ptr create_context(bool for_write) volatile = 0;
   virtual void stop() volatile = 0;
   virtual const config& get_conf() const volatile = 0;
@@ -57,7 +57,7 @@ struct prep_stmt {
 };
 
 struct dbcallback_i {
-  virtual ~dbcallback_i () { }
+  virtual ~dbcallback_i() = default;
   virtual void dbcb_set_prep_stmt(size_t pst_id, const prep_stmt& v) = 0;
   virtual const prep_stmt *dbcb_get_prep_stmt(size_t pst_id) const = 0;
   virtual void dbcb_resp_short(uint32_t code, const char *msg) = 0;
@@ -111,7 +111,7 @@ struct cmd_exec_args {
 };
 
 struct dbcontext_i {
-  virtual ~dbcontext_i() { }
+  virtual ~dbcontext_i() = default;
   virtual void init_thread(const void *stack_bottom,
     volatile int& shutdown_flag) = 0;
   virtual void term_thread() = 0;

diff --git a/plugin/handler_socket/handlersocket/hstcpsvr.hpp b/plugin/handler_socket/handlersocket/hstcpsvr.hpp
@@ -47,7 +47,7 @@ struct hstcpsvr_i;
 typedef std::auto_ptr<hstcpsvr_i> hstcpsvr_ptr;
 
 struct hstcpsvr_i {
-  virtual ~hstcpsvr_i() { }
+  virtual ~hstcpsvr_i() = default;
   virtual std::string start_listen() = 0;
   static hstcpsvr_ptr create(const config& conf);
 };

diff --git a/plugin/handler_socket/handlersocket/hstcpsvr_worker.hpp b/plugin/handler_socket/handlersocket/hstcpsvr_worker.hpp
@@ -24,7 +24,7 @@ struct hstcpsvr_worker_arg {
 };
 
 struct hstcpsvr_worker_i {
-  virtual ~hstcpsvr_worker_i() { }
+  virtual ~hstcpsvr_worker_i() = default;
   virtual void run() = 0;
   static hstcpsvr_worker_ptr create(const hstcpsvr_worker_arg& arg);
 };

diff --git a/plugin/handler_socket/libhsclient/hstcpcli.hpp b/plugin/handler_socket/libhsclient/hstcpcli.hpp
@@ -33,7 +33,7 @@ struct hstcpcli_i;
 typedef std::auto_ptr<hstcpcli_i> hstcpcli_ptr;
 
 struct hstcpcli_i {
-  virtual ~hstcpcli_i() { }
+  virtual ~hstcpcli_i() = default;
   virtual void close() = 0;
   virtual int reconnect() = 0;
   virtual bool stable_point() = 0;

diff --git a/plugin/handler_socket/libhsclient/util.hpp b/plugin/handler_socket/libhsclient/util.hpp
@@ -13,7 +13,7 @@ namespace dena {
 
 /* boost::noncopyable */
 struct noncopyable {
-  noncopyable() { }
+  noncopyable() = default;
  private:
   noncopyable(const noncopyable&);
   noncopyable& operator =(const noncopyable&);

diff --git a/plugin/query_response_time/query_response_time.cc b/plugin/query_response_time/query_response_time.cc
@@ -153,7 +153,7 @@ class time_collector
 
 public:
   time_collector(utility& u): m_utility(&u) { flush(); }
-  ~time_collector() { }
+  ~time_collector() = default;
   uint32_t count(uint index) { return m_count[index]; }
   uint64_t total(uint index) { return m_total[index]; }
   void flush()

diff --git a/plugin/versioning/versioning.cc b/plugin/versioning/versioning.cc
@@ -35,8 +35,8 @@ class Create_func_trt : public Create_native_func
   static Create_func_trt<TRT_FIELD> s_singleton;
 
 protected:
-  Create_func_trt<TRT_FIELD>() {}
-  virtual ~Create_func_trt<TRT_FIELD>() {}
+  Create_func_trt<TRT_FIELD>() = default;
+  virtual ~Create_func_trt<TRT_FIELD>() = default;
 };
 
 template<TR_table::field_id_t TRT_FIELD>
@@ -131,8 +131,8 @@ class Create_func_trt_trx_sees : public Create_native_func
   static Create_func_trt_trx_sees<Item_func_trt_trx_seesX> s_singleton;
 
 protected:
-  Create_func_trt_trx_sees<Item_func_trt_trx_seesX>() {}
-  virtual ~Create_func_trt_trx_sees<Item_func_trt_trx_seesX>() {}
+  Create_func_trt_trx_sees<Item_func_trt_trx_seesX>() = default;
+  virtual ~Create_func_trt_trx_sees<Item_func_trt_trx_seesX>() = default;
 };
 
 template<class X>

diff --git a/sql/derived_handler.h b/sql/derived_handler.h
@@ -56,7 +56,7 @@ class derived_handler
   derived_handler(THD *thd_arg, handlerton *ht_arg)
     : thd(thd_arg), ht(ht_arg), derived(0),table(0), tmp_table_param(0),
     unit(0), select(0) {}
-  virtual ~derived_handler() {}
+  virtual ~derived_handler() = default;
 
   /*
     Functions to scan data. All these returns 0 if ok, error code in case

diff --git a/sql/event_data_objects.cc b/sql/event_data_objects.cc
@@ -314,9 +314,7 @@ Event_queue_element::Event_queue_element():
   SYNOPSIS
     Event_queue_element::Event_queue_element()
 */
-Event_queue_element::~Event_queue_element()
-{
-}
+Event_queue_element::~Event_queue_element() = default;
 
 
 /*
@@ -342,9 +340,7 @@ Event_timed::Event_timed():
     Event_timed::~Event_timed()
 */
 
-Event_timed::~Event_timed()
-{
-}
+Event_timed::~Event_timed() = default;
 
 
 /*

diff --git a/sql/event_db_repository.h b/sql/event_db_repository.h
@@ -71,7 +71,7 @@ class Event_parse_data;
 class Event_db_repository
 {
 public:
-  Event_db_repository(){}
+  Event_db_repository() = default;
 
   bool
   create_event(THD *thd, Event_parse_data *parse_data,

diff --git a/sql/field.h b/sql/field.h
@@ -562,7 +562,7 @@ class Virtual_column_info: public Sql_alloc,
     name.length= 0;
   };
   Virtual_column_info* clone(THD *thd);
-  ~Virtual_column_info() {};
+  ~Virtual_column_info() = default;
   enum_vcol_info_type get_vcol_type() const
   {
     return vcol_type;
@@ -761,7 +761,7 @@ class Field: public Value_source
   Field(uchar *ptr_arg,uint32 length_arg,uchar *null_ptr_arg,
         uchar null_bit_arg, utype unireg_check_arg,
         const LEX_CSTRING *field_name_arg);
-  virtual ~Field() {}
+  virtual ~Field() = default;
 
   DTCollation dtcollation() const
   {
@@ -5215,7 +5215,7 @@ class Send_field :public Sql_alloc,
   LEX_CSTRING col_name, org_col_name;
   ulong length;
   uint flags, decimals;
-  Send_field() {}
+  Send_field() = default;
   Send_field(Field *field)
   {
     field->make_send_field(this);
@@ -5320,8 +5320,8 @@ class Copy_field :public Sql_alloc {
   Field *from_field,*to_field;
   String tmp;					// For items
 
-  Copy_field() {}
-  ~Copy_field() {}
+  Copy_field() = default;
+  ~Copy_field() = default;
   void set(Field *to,Field *from,bool save);	// Field to field 
   void set(uchar *to,Field *from);		// Field to string
   void (*do_copy)(Copy_field *);

diff --git a/sql/filesort_utils.h b/sql/filesort_utils.h
@@ -112,17 +112,11 @@ class Filesort_buffer
   /**
     We need an assignment operator, see filesort().
     This happens to have the same semantics as the one that would be
-    generated by the compiler. We still implement it here, to show shallow
-    assignment explicitly: we have two objects sharing the same array.
+    generated by the compiler.
+    Note that this is a shallow copy. We have two objects sharing the same
+    array.
   */
-  Filesort_buffer &operator=(const Filesort_buffer &rhs)
-  {
-    m_idx_array= rhs.m_idx_array;
-    m_record_length= rhs.m_record_length;
-    m_start_of_data= rhs.m_start_of_data;
-    allocated_size=  rhs.allocated_size;
-    return *this;
-  }
+  Filesort_buffer &operator=(const Filesort_buffer &rhs) = default;
 
 private:
   typedef Bounds_checked_array<uchar*> Idx_array;

diff --git a/sql/gcalc_slicescan.h b/sql/gcalc_slicescan.h
@@ -344,7 +344,7 @@ class Gcalc_shape_transporter
   {
     return complete_ring() || complete_poly();
   }
-  virtual ~Gcalc_shape_transporter() {}
+  virtual ~Gcalc_shape_transporter() = default;
 };
 
 

diff --git a/sql/group_by_handler.h b/sql/group_by_handler.h
@@ -72,7 +72,7 @@ class group_by_handler
 
   group_by_handler(THD *thd_arg, handlerton *ht_arg)
     : thd(thd_arg), ht(ht_arg), table(0) {}
-  virtual ~group_by_handler() {}
+  virtual ~group_by_handler() = default;
 
   /*
     Functions to scan data. All these returns 0 if ok, error code in case

diff --git a/sql/handler.h b/sql/handler.h
@@ -842,7 +842,7 @@ struct xid_t {
   long bqual_length;
   char data[XIDDATASIZE];  // not \0-terminated !
 
-  xid_t() {}                                /* Remove gcc warning */
+  xid_t() = default;                                /* Remove gcc warning */
   bool eq(struct xid_t *xid) const
   { return !xid->is_null() && eq(xid->gtrid_length, xid->bqual_length, xid->data); }
   bool eq(long g, long b, const char *d) const
@@ -1529,7 +1529,7 @@ struct handlerton
      public:
      virtual bool add_table(const char *tname, size_t tlen) = 0;
      virtual bool add_file(const char *fname) = 0;
-     protected: virtual ~discovered_list() {}
+     protected: virtual ~discovered_list() = default;
    };
 
    /*
@@ -1710,7 +1710,7 @@ struct THD_TRANS
     m_unsafe_rollback_flags= 0;
   }
   bool is_empty() const { return ha_list == NULL; }
-  THD_TRANS() {}                        /* Remove gcc warning */
+  THD_TRANS() = default;                        /* Remove gcc warning */
 
   unsigned int m_unsafe_rollback_flags;
  /*
@@ -1954,7 +1954,7 @@ struct Table_period_info: Sql_alloc
 
   struct start_end_t
   {
-    start_end_t() {};
+    start_end_t() = default;
     start_end_t(const LEX_CSTRING& _start, const LEX_CSTRING& _end) :
       start(_start),
       end(_end) {}
@@ -2262,9 +2262,9 @@ struct Table_specification_st: public HA_CREATE_INFO,
 class inplace_alter_handler_ctx : public Sql_alloc
 {
 public:
-  inplace_alter_handler_ctx() {}
+  inplace_alter_handler_ctx() = default;
 
-  virtual ~inplace_alter_handler_ctx() {}
+  virtual ~inplace_alter_handler_ctx() = default;
   virtual void set_shared_data(const inplace_alter_handler_ctx& ctx) {}
 };
 
@@ -2490,8 +2490,8 @@ typedef struct st_key_create_information
 class TABLEOP_HOOKS
 {
 public:
-  TABLEOP_HOOKS() {}
-  virtual ~TABLEOP_HOOKS() {}
+  TABLEOP_HOOKS() = default;
+  virtual ~TABLEOP_HOOKS() = default;
 
   inline void prelock(TABLE **tables, uint count)
   {
@@ -2532,7 +2532,7 @@ typedef class Item COND;
 
 typedef struct st_ha_check_opt
 {
-  st_ha_check_opt() {}                        /* Remove gcc warning */
+  st_ha_check_opt() = default;                        /* Remove gcc warning */
   uint flags;       /* isam layer flags (e.g. for myisamchk) */
   uint sql_flags;   /* sql layer flags - for something myisamchk cannot do */
   time_t start_time;   /* When check/repair starts */
@@ -2911,8 +2911,8 @@ uint calculate_key_len(TABLE *, uint, const uchar *, key_part_map);
 class Handler_share
 {
 public:
-  Handler_share() {}
-  virtual ~Handler_share() {}
+  Handler_share() = default;
+  virtual ~Handler_share() = default;
 };
 
 enum class Compare_keys : uint32_t
@@ -4969,7 +4969,7 @@ class Discovered_table_list: public handlerton::discovered_list
                         const LEX_CSTRING *wild_arg);
   Discovered_table_list(THD *thd_arg, Dynamic_array<LEX_CSTRING*> *tables_arg)
     : thd(thd_arg), wild(NULL), with_temps(true), tables(tables_arg) {}
-  ~Discovered_table_list() {}
+  ~Discovered_table_list() = default;
 
   bool add_table(const char *tname, size_t tlen);
   bool add_file(const char *fname);

diff --git a/sql/hash_filo.h b/sql/hash_filo.h
@@ -35,7 +35,7 @@ class hash_filo_element
 private:
   hash_filo_element *next_used,*prev_used;
  public:
-  hash_filo_element() {}
+  hash_filo_element() = default;
   hash_filo_element *next()
   { return next_used; }
   hash_filo_element *prev()