Bug #30199590: RUN CLANG-TIDY MODERNIZE-USE-NULLPTR

Another cross-cutting, large-scale clang-tidy fix. It runs the
“modernize-use-nullptr” fixit over all source code compiled in a fairly
full-featured MySQL build, changing 0 literals (in pointer context)
and NULL to nullptr. A typical example would be:

-  mysql_options(connection, MYSQL_OPT_CONNECT_ATTR_RESET, 0);
+  mysql_options(connection, MYSQL_OPT_CONNECT_ATTR_RESET, nullptr);

as the third argument to mysql_options() is a void *.

Converting 0 and NULL literals to nullptr makes code easier to read by
increasing self-documentation, makes type and argument order mistakes more
difficult, enable compiler warnings when nonsensical operations are attempted
(such as adding pointers), enable perfect forwarding in more cases (NULL cannot
be perfect forwarded, nullptr can) and reduces noise from IDEs and other tools
that check clang-tidy warnings.

Change-Id: Ic863d0a52a78b46f6345e3b69b60bd3dab317e9a

client/base/abstract_option.h

@@ -126,7 +126,7 @@ T_type *Abstract_option<T_type>::set_short_character(char code) {
   this->m_option_structure.id = (int)code;
 
   // Inform that it has changed
-  if (this->m_option_changed_listener != NULL) {
+  if (this->m_option_changed_listener != nullptr) {
     this->m_option_changed_listener->notify_option_optid_changed(this,
                                                                  old_optid);
   }
@@ -139,12 +139,12 @@ Abstract_option<T_type>::Abstract_option(void *value, ulong var_type,
                                          std::string name,
                                          std::string description,
                                          longlong default_value)
-    : m_option_changed_listener(NULL) {
+    : m_option_changed_listener(nullptr) {
   this->m_option_structure.block_size = 0;
   this->m_option_structure.max_value = 0;
   this->m_option_structure.min_value = 0;
-  this->m_option_structure.typelib = NULL;
-  this->m_option_structure.u_max_value = NULL;
+  this->m_option_structure.typelib = nullptr;
+  this->m_option_structure.u_max_value = nullptr;
 
   this->m_option_structure.app_type = this;
   this->m_option_structure.arg_type = REQUIRED_ARG;
@@ -166,7 +166,7 @@ Abstract_option<T_type>::Abstract_option(void *value, ulong var_type,
 
   this->m_option_structure.value = value;
   this->m_option_structure.var_type = var_type;
-  this->m_option_structure.arg_source = 0;
+  this->m_option_structure.arg_source = nullptr;
 }
 
 template <typename T_type>
@@ -177,7 +177,7 @@ my_option Abstract_option<T_type>::get_my_option() {
 template <typename T_type>
 void Abstract_option<T_type>::set_option_changed_listener(
     I_option_changed_listener *listener) {
-  DBUG_ASSERT(this->m_option_changed_listener == NULL);
+  DBUG_ASSERT(this->m_option_changed_listener == nullptr);
 
   this->m_option_changed_listener = listener;
 }

client/base/abstract_options_provider.cc

@@ -1,5 +1,5 @@
 /*
-   Copyright (c) 2001, 2017, Oracle and/or its affiliates. All rights reserved.
+   Copyright (c) 2001, 2019, Oracle and/or its affiliates. All rights reserved.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License, version 2.0,
@@ -122,7 +122,7 @@ vector<my_option> Abstract_options_provider::generate_options() {
 void Abstract_options_provider::options_parsed() {}
 
 Abstract_options_provider::Abstract_options_provider()
-    : m_are_options_created(false), m_option_changed_listener(NULL) {}
+    : m_are_options_created(false), m_option_changed_listener(nullptr) {}
 
 Abstract_options_provider::~Abstract_options_provider() {
   for (vector<I_option *>::iterator it = this->m_options_created.begin();
@@ -133,7 +133,7 @@ Abstract_options_provider::~Abstract_options_provider() {
 
 void Abstract_options_provider::set_option_changed_listener(
     I_option_changed_listener *listener) {
-  DBUG_ASSERT(this->m_option_changed_listener == NULL);
+  DBUG_ASSERT(this->m_option_changed_listener == nullptr);
   this->m_option_changed_listener = listener;
 }
 
@@ -163,7 +163,7 @@ void Abstract_options_provider::notify_option_name_changed(I_option *source,
   this->m_name_usage.insert(std::make_pair(new_name, source));
 
   // If we have listener we should inform it too.
-  if (this->m_option_changed_listener != NULL) {
+  if (this->m_option_changed_listener != nullptr) {
     this->m_option_changed_listener->notify_option_name_changed(source,
                                                                 old_name);
   }
@@ -197,7 +197,7 @@ void Abstract_options_provider::notify_option_optid_changed(I_option *source,
   this->m_optid_usage.insert(std::make_pair(new_optid, source));
 
   // If we have listener we should inform it too.
-  if (this->m_option_changed_listener != NULL) {
+  if (this->m_option_changed_listener != nullptr) {
     this->m_option_changed_listener->notify_option_optid_changed(source,
                                                                  old_optid);
   }

client/base/abstract_program.cc

@@ -41,7 +41,7 @@ bool Abstract_program::callback_option_parsed(int, const struct my_option *opt,
   // Check if option uses My::Tools::Base::Options, and it should.
   Options::I_option *app_type = (Options::I_option *)opt->app_type;
   Options::I_option *option = dynamic_cast<Options::I_option *>(app_type);
-  if (option != NULL) {
+  if (option != nullptr) {
     option->call_callbacks(argument);
   }
   return false;
@@ -127,7 +127,9 @@ void Abstract_program::aggregate_options() {
             &Abstract_program::options_by_name_comparer);
 
   // Adding sentinel, handle_options assume input as array with sentinel.
-  my_option sentinel = {0, 0, 0, 0, 0, 0, GET_NO_ARG, NO_ARG, 0, 0, 0, 0, 0, 0};
+  my_option sentinel = {nullptr, 0,          nullptr, nullptr, nullptr,
+                        nullptr, GET_NO_ARG, NO_ARG,  0,       0,
+                        0,       nullptr,    0,       nullptr};
   this->m_options.push_back(sentinel);
 }
 

client/base/abstract_string_option.h

@@ -1,5 +1,5 @@
 /*
-   Copyright (c) 2014, 2017, Oracle and/or its affiliates. All rights reserved.
+   Copyright (c) 2014, 2019, Oracle and/or its affiliates. All rights reserved.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License, version 2.0,
@@ -77,7 +77,7 @@ Abstract_string_option<T_type>::Abstract_string_option(
                                     description, (uint64)NULL),
       m_destination_value(value) {
   *value = Nullable<std::string>();
-  this->m_original_value = NULL;
+  this->m_original_value = nullptr;
 
   this->add_callback(new std::function<void(char *)>(
       std::bind(&Abstract_string_option<T_type>::string_callback, this,
@@ -95,7 +95,7 @@ T_type *Abstract_string_option<T_type>::set_value(std::string value) {
 
 template <typename T_type>
 void Abstract_string_option<T_type>::string_callback(char *argument) {
-  if (argument != NULL) {
+  if (argument != nullptr) {
     // Copy argument value from char* to destination string.
     *this->m_destination_value = Nullable<std::string>(this->m_original_value);
   } else {

client/base/char_array_option.cc

@@ -1,5 +1,5 @@
 /*
-   Copyright (c) 2001, 2017, Oracle and/or its affiliates. All rights reserved.
+   Copyright (c) 2001, 2019, Oracle and/or its affiliates. All rights reserved.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License, version 2.0,
@@ -33,7 +33,7 @@ Char_array_option::Char_array_option(char **value, bool allocated, string name,
                                      string description)
     : Abstract_value_option<char *>(value, allocated ? GET_STR_ALLOC : GET_STR,
                                     name, description, (uint64)NULL) {
-  *value = NULL;
+  *value = nullptr;
 }
 
 Char_array_option *Char_array_option::set_value(char *value) {

client/base/composite_options_provider.cc

@@ -1,5 +1,5 @@
 /*
-   Copyright (c) 2001, 2017, Oracle and/or its affiliates. All rights reserved.
+   Copyright (c) 2001, 2019, Oracle and/or its affiliates. All rights reserved.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License, version 2.0,
@@ -45,7 +45,7 @@ void Composite_options_provider::add_providers(I_options_provider *first, ...) {
   for (;;) {
     Options::I_options_provider *options_provider =
         va_arg(options_to_add, I_options_provider *);
-    if (options_provider == NULL) {
+    if (options_provider == nullptr) {
       break;
     }
 

client/base/debug_options.cc

@@ -36,13 +36,13 @@ using namespace Mysql::Tools::Base::Options;
 using Mysql::Tools::Base::Abstract_program;
 using std::placeholders::_1;
 
-static Debug_options *primary_debug_options = NULL;
+static Debug_options *primary_debug_options = nullptr;
 static uint my_end_arg;
 
 static void debug_do_exit() { my_end(::my_end_arg); }
 
 Debug_options::Debug_options(Abstract_program *program) : m_program(program) {
-  if (::primary_debug_options == NULL) {
+  if (::primary_debug_options == nullptr) {
     primary_debug_options = this;
     /*
       We don't want to call this routine in destructor, as we want it being

client/base/disabled_option.cc

@@ -1,5 +1,5 @@
 /*
-   Copyright (c) 2001, 2017, Oracle and/or its affiliates. All rights reserved.
+   Copyright (c) 2001, 2019, Oracle and/or its affiliates. All rights reserved.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License, version 2.0,
@@ -30,7 +30,7 @@ using std::string;
 using namespace Mysql::Tools::Base::Options;
 
 Disabled_option::Disabled_option(string name, string description)
-    : Abstract_option<Disabled_option>(NULL, GET_DISABLED, name, description,
+    : Abstract_option<Disabled_option>(nullptr, GET_DISABLED, name, description,
                                        0) {
   this->m_option_structure.arg_type = OPT_ARG;
 }

client/base/mysql_connection_options.cc

@@ -52,7 +52,7 @@ Mysql_connection_options::Mysql_connection_options(Abstract_program *program)
     : m_ssl_options_provider(), m_program(program), m_protocol(0) {
   if (Mysql_connection_options::mysql_inited == false) {
     Mysql_connection_options::mysql_inited = true;
-    mysql_library_init(0, NULL, NULL);
+    mysql_library_init(0, nullptr, nullptr);
     atexit(atexit_mysql_library_end);
   }
 
@@ -141,7 +141,7 @@ void Mysql_connection_options::create_options() {
 }
 
 MYSQL *Mysql_connection_options::create_connection() {
-  MYSQL *connection = mysql_init(NULL);
+  MYSQL *connection = mysql_init(nullptr);
   if (this->m_compress) mysql_options(connection, MYSQL_OPT_COMPRESS, NullS);
 
   if (this->m_compress_algorithm.has_value())
@@ -152,7 +152,7 @@ MYSQL *Mysql_connection_options::create_connection() {
                 &this->m_zstd_compress_level);
 
   if (this->m_ssl_options_provider.apply_for_connection(connection))
-    return NULL;
+    return nullptr;
 
   if (this->m_protocol)
     mysql_options(connection, MYSQL_OPT_PROTOCOL, (char *)&this->m_protocol);
@@ -178,7 +178,7 @@ MYSQL *Mysql_connection_options::create_connection() {
     mysql_options(connection, MYSQL_DEFAULT_AUTH,
                   this->m_default_auth.value().c_str());
 
-  mysql_options(connection, MYSQL_OPT_CONNECT_ATTR_RESET, 0);
+  mysql_options(connection, MYSQL_OPT_CONNECT_ATTR_RESET, nullptr);
   mysql_options4(connection, MYSQL_OPT_CONNECT_ATTR_ADD, "program_name",
                  this->m_program->get_name().c_str());
 
@@ -190,21 +190,22 @@ MYSQL *Mysql_connection_options::create_connection() {
     set_get_server_public_key_option(connection,
                                      &this->m_get_server_public_key);
 
-  if (!mysql_real_connect(
-          connection, this->get_null_or_string(this->m_host),
-          this->get_null_or_string(this->m_user),
-          this->get_null_or_string(this->m_password), NULL, this->m_mysql_port,
-          this->get_null_or_string(this->m_mysql_unix_port), 0)) {
+  if (!mysql_real_connect(connection, this->get_null_or_string(this->m_host),
+                          this->get_null_or_string(this->m_user),
+                          this->get_null_or_string(this->m_password), nullptr,
+                          this->m_mysql_port,
+                          this->get_null_or_string(this->m_mysql_unix_port),
+                          0)) {
     this->db_error(connection, "while connecting to the MySQL server");
     mysql_close(connection);
-    return NULL;
+    return nullptr;
   }
 
   /* Reset auto-commit to the default */
   if (mysql_autocommit(connection, true)) {
     this->db_error(connection, "while resetting auto-commit");
     mysql_close(connection);
-    return NULL;
+    return nullptr;
   }
 
   return connection;
@@ -214,7 +215,7 @@ CHARSET_INFO *Mysql_connection_options::get_current_charset() const {
   return m_default_charset.has_value()
              ? get_charset_by_csname(m_default_charset.value().c_str(),
                                      MY_CS_PRIMARY, MYF(MY_WME))
-             : NULL;
+             : nullptr;
 }
 
 void Mysql_connection_options::set_current_charset(CHARSET_INFO *charset) {
@@ -226,7 +227,7 @@ const char *Mysql_connection_options::get_null_or_string(
   if (maybe_string.has_value()) {
     return maybe_string.value().c_str();
   } else {
-    return NULL;
+    return nullptr;
   }
 }
 

client/base/mysql_query_runner.cc

@@ -1,5 +1,5 @@
 /*
-   Copyright (c) 2014, 2017, Oracle and/or its affiliates. All rights reserved.
+   Copyright (c) 2014, 2019, Oracle and/or its affiliates. All rights reserved.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License, version 2.0,
@@ -125,12 +125,12 @@ int64 Mysql_query_runner::run_query_unguarded(string query) {
 
   MYSQL_RES *results = mysql_use_result(m_connection);
 
-  if (results != NULL) {
+  if (results != nullptr) {
     for (;;) {
       // Feed result callbacks with results.
       MYSQL_ROW row = mysql_fetch_row(results);
 
-      if (row == NULL) {
+      if (row == nullptr) {
         // NULL row indicates end of rows or error
         if (mysql_errno(m_connection) == 0)
           break;
@@ -160,7 +160,7 @@ int64 Mysql_query_runner::run_query_unguarded(string query) {
 
   // Get all notes, warnings and errors of last query.
   if (0 != mysql_query(m_connection, "SHOW WARNINGS") ||
-      NULL == (results = mysql_use_result(m_connection))) {
+      nullptr == (results = mysql_use_result(m_connection))) {
     this->report_mysql_error();
     return 0;
   }
@@ -170,7 +170,7 @@ int64 Mysql_query_runner::run_query_unguarded(string query) {
     // Feed message callbacks with results.
     MYSQL_ROW row = mysql_fetch_row(results);
 
-    if (row == NULL) {
+    if (row == nullptr) {
       // End of rows or an error.
       if (mysql_errno(m_connection) != 0) this->report_mysql_error();
       break;
@@ -297,7 +297,7 @@ void Mysql_query_runner::cleanup_result(
 
 Mysql_query_runner::Row::Row(MYSQL_RES *mysql_result_info,
                              unsigned int column_count, MYSQL_ROW row)
-    : m_buffer(NULL),
+    : m_buffer(nullptr),
       m_buffer_capacity(0),
       m_buffer_size(0),
       m_mysql_result_info(mysql_result_info) {
@@ -315,7 +315,7 @@ Mysql_query_runner::Row::Row(MYSQL_RES *mysql_result_info,
 }
 
 Mysql_query_runner::Row::~Row() {
-  if (m_buffer != NULL) free(m_buffer);
+  if (m_buffer != nullptr) free(m_buffer);
 }
 
 std::string Mysql_query_runner::Row::operator[](std::size_t index) const {
@@ -325,7 +325,7 @@ std::string Mysql_query_runner::Row::operator[](std::size_t index) const {
 }
 
 void Mysql_query_runner::Row::push_back(char *buff, std::size_t length) {
-  if (buff != NULL) {
+  if (buff != nullptr) {
     // Prepare buffer to be able to contain new data.
     this->reserve(m_buffer_starts.size(), m_buffer_size + length + 1);
     // Copy data.

client/base/password_option.cc

@@ -49,7 +49,7 @@ void Password_option::password_callback(char *argument) {
     argument = const_cast<char *>("");
   }
 
-  if (argument != NULL) {
+  if (argument != nullptr) {
     /*
      Destroy argument value, this modifies part of argv passed to main
      routine. This makes command line on linux changed, so no user can see
@@ -66,7 +66,7 @@ void Password_option::password_callback(char *argument) {
      */
     if (*argument) argument[1] = 0;
   } else {
-    char *password = ::get_tty_password(NULL);
+    char *password = ::get_tty_password(nullptr);
     *this->m_destination_value = Nullable<string>(password);
     my_free(password);
   }

client/base/simple_option.cc

@@ -1,5 +1,5 @@
 /*
-   Copyright (c) 2001, 2017, Oracle and/or its affiliates. All rights reserved.
+   Copyright (c) 2001, 2019, Oracle and/or its affiliates. All rights reserved.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License, version 2.0,
@@ -30,6 +30,7 @@ using namespace Mysql::Tools::Base::Options;
 using std::string;
 
 Simple_option::Simple_option(string name, string description)
-    : Abstract_option<Simple_option>(NULL, GET_NO_ARG, name, description, 0) {
+    : Abstract_option<Simple_option>(nullptr, GET_NO_ARG, name, description,
+                                     0) {
   this->m_option_structure.arg_type = NO_ARG;
 }