Add missing const and nodiscard keywords and update to c++23 and c17

.kdev4/persephone.kdev4

@@ -10,8 +10,8 @@ checkUnusedFunction=true
 [CustomDefinesAndIncludes][ProjectPath0]
 Path=.
 parseAmbiguousAsCPP=true
-parserArguments=-ferror-limit=100 -fspell-checking -Wdocumentation -Wunused-parameter -Wunreachable-code -Wall -std=c++2a
-parserArgumentsC=-ferror-limit=100 -fspell-checking -Wdocumentation -Wunused-parameter -Wunreachable-code -Wall -std=c11
+parserArguments=-ferror-limit=100 -fspell-checking -Wdocumentation -Wunused-parameter -Wunreachable-code -Wall -std=c++23
+parserArgumentsC=-ferror-limit=100 -fspell-checking -Wdocumentation -Wunused-parameter -Wunreachable-code -Wall -std=c17
 parserArgumentsCuda=-ferror-limit=100 -fspell-checking -Wdocumentation -Wunused-parameter -Wunreachable-code -Wall -std=c++11
 parserArgumentsOpenCL=-ferror-limit=100 -fspell-checking -Wdocumentation -Wunused-parameter -Wunreachable-code -Wall -cl-std=CL1.1
 

meson.build

@@ -1,19 +1,18 @@
 project(
-    'persephone',
-    'cpp',
-    version: '0.1.0',
-    default_options: [
-        'cpp_std=c++20',
-        'c_std=c11',
-        'warning_level=3',
-        # yaml_cpp break werror. Fixes appreciated
-        #'werror=true',
-        'b_lto=true',
-        'b_thinlto_cache=true',
-        #'b_sanitize=address,undefined',
-        # Clang fails to link with sanatizers without this: https://github.com/mesonbuild/meson/issues/764
-        #'b_lundef=false',
-    ],
+  'persephone',
+  'cpp',
+  version : '0.1.0',
+  default_options : [
+    'cpp_std=c++23',
+    'c_std=c17',
+    'warning_level=3',
+    # yaml_cpp break werror. Fixes appreciated
+    #'werror=true',
+    'b_lto=true',
+    'b_thinlto_cache=true',
+    # Clang fails to link with sanatizers without this: https://github.com/mesonbuild/meson/issues/764
+    #'b_lundef=false',
+  ]
 )
 #
 add_project_arguments(

src/database/database.cpp

@@ -7,12 +7,12 @@
 #include <stdexcept>
 #include <zlib.h>
 
-void Database::migrate() {
+void Database::migrate() const {
   Migrator migrator;
   migrator.migrate();
 }
 
-drogon::Task<Database::UserCreationResp>
+[[nodiscard]] drogon::Task<Database::UserCreationResp>
 Database::create_user(Database::UserCreationData const &data) const {
   auto sql = drogon::app().getDbClient();
 
@@ -63,7 +63,8 @@ Database::create_user(Database::UserCreationData const &data) const {
   co_return resp_data;
 }
 
-drogon::Task<bool> Database::user_exists(std::string matrix_id) const {
+[[nodiscard]] drogon::Task<bool>
+Database::user_exists(std::string matrix_id) const {
   auto sql = drogon::app().getDbClient();
   try {
     auto f = co_await sql->execSqlCoro(
@@ -79,7 +80,7 @@ drogon::Task<bool> Database::user_exists(std::string matrix_id) const {
   }
 }
 
-drogon::Task<std::optional<Database::UserInfo>>
+[[nodiscard]] drogon::Task<std::optional<Database::UserInfo>>
 Database::get_user_info(std::string auth_token) const {
   auto sql = drogon::app().getDbClient();
   try {
@@ -112,7 +113,7 @@ Database::get_user_info(std::string auth_token) const {
   }
 }
 
-drogon::Task<bool>
+[[nodiscard]] drogon::Task<bool>
 Database::validate_access_token(std::string auth_token) const {
   auto sql = drogon::app().getDbClient();
   try {

src/database/database.hpp

@@ -20,7 +20,7 @@ void prepare_statements();
  */
 class Database {
 public:
-  void migrate();
+  void migrate() const;
 
   struct [[nodiscard]] UserCreationData {
     std::string matrix_id;

src/database/migrations/migrator.cpp

@@ -1,6 +1,6 @@
 #include "migrator.hpp"
 
-void Migrator::migrate() {
+void Migrator::migrate() const {
   LOG_INFO << "Starting database migration";
   this->migration_v0();
   this->migration_v1();
@@ -10,7 +10,7 @@ void Migrator::migrate() {
   LOG_INFO << "Finished database migration";
 }
 
-void Migrator::migration_v0() {
+void Migrator::migration_v0() const {
   auto sql = drogon::app().getDbClient("default");
   assert(sql);
   try {
@@ -25,7 +25,7 @@ void Migrator::migration_v0() {
   }
 }
 
-void Migrator::migration_v1() {
+void Migrator::migration_v1() const {
   LOG_INFO << "Starting database migration v0->v1";
   auto sql = drogon::app().getDbClient("default");
   assert(sql);
@@ -159,7 +159,7 @@ void Migrator::migration_v1() {
   }
 }
 
-void Migrator::migration_v2() {
+void Migrator::migration_v2() const {
   LOG_INFO << "Starting database migration v1->v2";
   auto sql = drogon::app().getDbClient();
   assert(sql);
@@ -203,7 +203,7 @@ void Migrator::migration_v2() {
   }
 }
 
-void Migrator::migration_v3() {
+void Migrator::migration_v3() const {
   LOG_INFO << "Starting database migration v2->v3";
   auto sql = drogon::app().getDbClient();
   assert(sql);

src/database/migrations/migrator.hpp

@@ -3,11 +3,11 @@
 
 class Migrator {
 public:
-  void migrate();
+  void migrate() const;
 
 private:
-  void migration_v0();
-  void migration_v1();
-  void migration_v2();
-  void migration_v3();
+  void migration_v0() const;
+  void migration_v1() const;
+  void migration_v2() const;
+  void migration_v3() const;
 };

src/utils/config.hpp

@@ -32,7 +32,7 @@ struct [[nodiscard]] Config {
   MatrixConfig matrix_config;
   WebserverConfig webserver_config;
 
-  explicit Config() {
+  [[nodiscard]] explicit Config() {
     LOG_INFO << "Loading config file";
     YAML::Node config = YAML::LoadFile("config.yaml");
     this->load_db(config);

src/utils/json_utils.cpp

@@ -13,7 +13,8 @@
 #include <stdexcept>
 
 namespace json_utils {
-std::vector<unsigned char> unbase64_key(const std::string &input) {
+[[nodiscard]] std::vector<unsigned char>
+unbase64_key(const std::string &input) {
   size_t b64_str_len = input.size();
   size_t bin_len = b64_str_len * (static_cast<size_t>(4) * 3);
   std::vector<unsigned char> bin_str(bin_len);
@@ -29,7 +30,7 @@ std::vector<unsigned char> unbase64_key(const std::string &input) {
   return bin_str;
 }
 
-std::string base64_key(const std::vector<unsigned char> &input) {
+[[nodiscard]] std::string base64_key(const std::vector<unsigned char> &input) {
   unsigned long long private_key_len = input.size();
   const size_t base64_max_len = sodium_base64_encoded_len(
       private_key_len, sodium_base64_VARIANT_URLSAFE_NO_PADDING);
@@ -45,8 +46,10 @@ std::string base64_key(const std::vector<unsigned char> &input) {
   return base64_str;
 }
 
-json sign_json(const std::string &server_name, const std::string &key_id,
-               const std::vector<unsigned char> &secret_key, json json_data) {
+[[nodiscard]] json sign_json(const std::string &server_name,
+                             const std::string &key_id,
+                             const std::vector<unsigned char> &secret_key,
+                             json json_data) {
   // Get existing (or not yet existing) signatures and unsigned fields
   auto signatures = json_data.value("signatures", json(json::value_t::object));
   auto unsigned_value = json_data.value("unsigned", json{});
@@ -81,8 +84,8 @@ json sign_json(const std::string &server_name, const std::string &key_id,
   return json_data;
 }
 
-std::tuple<std::array<unsigned char, crypto_sign_PUBLICKEYBYTES>,
-           std::array<unsigned char, crypto_sign_SECRETKEYBYTES>>
+[[nodiscard]] std::tuple<std::array<unsigned char, crypto_sign_PUBLICKEYBYTES>,
+                         std::array<unsigned char, crypto_sign_SECRETKEYBYTES>>
 generate_server_key() {
   std::array<unsigned char, crypto_sign_PUBLICKEYBYTES> pk;
   std::array<unsigned char, crypto_sign_SECRETKEYBYTES> sk;

src/utils/state_res.cpp

@@ -27,7 +27,7 @@
  * "m.room.join_rules", "m.room.power_levels", "m.room.history_visibility",
  * "m.room.redaction", and others.
  */
-json v11_redact(const json &event) {
+[[nodiscard]] json v11_redact(const json &event) {
   //  We copy here to (if needed) have the original still intact
   json event_copy(event);
 
@@ -94,14 +94,14 @@ json v11_redact(const json &event) {
   return event_copy;
 }
 
-json redact(const json &event, const std::string &room_version) {
+[[nodiscard]] json redact(const json &event, const std::string &room_version) {
   if (room_version == "11") {
     return v11_redact(event);
   }
   throw MatrixRoomVersionError(room_version);
 }
 
-std::string reference_hash_v11(const json &event) {
+[[nodiscard]] std::string reference_hash_v11(const json &event) {
   //  We copy here to (if needed) have the original still intact
   json event_copy(event);
 
@@ -119,15 +119,17 @@ std::string reference_hash_v11(const json &event) {
   return sha256_hash_string;
 }
 
-std::string reference_hash(const json &event, const std::string &room_version) {
+[[nodiscard]] std::string reference_hash(const json &event,
+                                         const std::string &room_version) {
   if (room_version == "11") {
     return reference_hash_v11(event);
   }
 
   throw MatrixRoomVersionError(room_version);
 }
 
-std::string event_id(const json &event, const std::string &room_version) {
+[[nodiscard]] std::string event_id(const json &event,
+                                   const std::string &room_version) {
   auto hash = reference_hash(event, room_version);
 
   unsigned long long hash_len = hash.size();
@@ -148,7 +150,7 @@ std::string event_id(const json &event, const std::string &room_version) {
 
 // Function to create the partial state map from unconflicted events while
 // preserving ordering
-std::map<EventType, std::map<StateKey, StateEvent>>
+[[nodiscard]] std::map<EventType, std::map<StateKey, StateEvent>>
 createPartialState(const std::vector<StateEvent> &unconflictedEvents) {
   std::map<EventType, std::map<StateKey, StateEvent>> partialState;
 
@@ -163,7 +165,8 @@ createPartialState(const std::vector<StateEvent> &unconflictedEvents) {
   return partialState;
 }
 
-StateEventSets splitEvents(const std::vector<std::vector<StateEvent>> &forks) {
+[[nodiscard]] StateEventSets
+splitEvents(const std::vector<std::vector<StateEvent>> &forks) {
   StateEventSets result;
   std::vector<std::map<std::pair<EventType, StateKey>, int>> stateTuples(
       forks.size());
@@ -213,7 +216,7 @@ StateEventSets splitEvents(const std::vector<std::vector<StateEvent>> &forks) {
   return result;
 }
 
-std::map<EventID, int>
+[[nodiscard]] std::map<EventID, int>
 sorted_incoming_edges(const std::map<EventID, int> &incoming_edges,
                       const std::map<EventID, StateEvent> &event_map) {
   auto comparator = [&](const EventID &x, const EventID &y) {
@@ -250,7 +253,7 @@ sorted_incoming_edges(const std::map<EventID, int> &incoming_edges,
   return sorted_edges;
 }
 
-std::vector<StateEvent>
+[[nodiscard]] std::vector<StateEvent>
 kahns_algorithm(const std::vector<StateEvent> &full_conflicted_set) {
   std::vector<StateEvent> output_events;
   std::map<EventID, StateEvent> event_map;
@@ -286,7 +289,7 @@ kahns_algorithm(const std::vector<StateEvent> &full_conflicted_set) {
   return output_events;
 }
 
-bool auth_against_partial_state_version_11(
+[[nodiscard]] bool auth_against_partial_state_version_11(
     const std::map<EventType, std::map<StateKey, StateEvent>>
         &current_partial_state,
     StateEvent &e) {
@@ -366,7 +369,7 @@ bool auth_against_partial_state_version_11(
 // This checks if the event is allowed by the auth checks
 // These are defined in
 // https://spec.matrix.org/v1.9/rooms/v11/#authorization-rules
-bool auth_against_partial_state(
+[[nodiscard]] bool auth_against_partial_state(
     std::map<EventType, std::map<StateKey, StateEvent>> &current_partial_state,
     StateEvent &e) {
   if (e["type"].get<std::string>() == "m.room.create") {
@@ -400,7 +403,7 @@ void mainline_iterate(std::vector<StateEvent> &power_level_mainline,
   }
 }
 
-StateEvent
+[[nodiscard]] StateEvent
 get_closest_mainline_event(std::vector<StateEvent> &power_level_mainline,
                            StateEvent &event) {
   StateEvent closest_mainline_event;
@@ -431,7 +434,7 @@ get_closest_mainline_event(std::vector<StateEvent> &power_level_mainline,
   return closest_mainline_event;
 }
 
-std::vector<StateEvent>
+[[nodiscard]] std::vector<StateEvent>
 sorted_normal_state_events(std::vector<StateEvent> normal_events) {
   auto compare_events = [](StateEvent &x, StateEvent &y) {
     if (x["position_on_mainline"].get<std::string>() !=
@@ -452,7 +455,7 @@ sorted_normal_state_events(std::vector<StateEvent> normal_events) {
   return normal_events;
 }
 
-std::map<EventType, std::map<StateKey, StateEvent>>
+[[nodiscard]] std::map<EventType, std::map<StateKey, StateEvent>>
 stateres_v2(const std::vector<std::vector<StateEvent>> &forks) {
   auto state_event_sets = splitEvents(forks);
   auto partial_state = createPartialState(state_event_sets.unconflictedEvents);

src/utils/state_res.hpp

@@ -11,7 +11,7 @@ using EventType = std::string;
 using StateKey = std::string;
 
 // Custom struct to hold conflicted and unconflicted state sets
-struct StateEventSets {
+struct [[nodiscard]] StateEventSets {
   std::vector<StateEvent> conflictedEvents;
   std::vector<StateEvent> unconflictedEvents;
 };

src/utils/utils.hpp

@@ -14,21 +14,21 @@ using namespace drogon;
 
 constexpr auto UserAgent = "persephone/0.1.0";
 
-struct SRVRecord {
+struct [[nodiscard]] SRVRecord {
   std::string host;
   unsigned int port;
   unsigned short int priority;
   unsigned short int weight;
 };
 
-struct ResolvedServer {
+struct [[nodiscard]] ResolvedServer {
   std::string address;
   // Unsigned long since conversion from string is a little easier here
   unsigned long port;
   std::string server_name;
 };
 
-struct HTTPRequest {
+struct [[nodiscard]] HTTPRequest {
   drogon::HttpClientPtr client;
   drogon::HttpMethod method;
   std::string path;
@@ -40,7 +40,7 @@ struct HTTPRequest {
   int timeout;
 };
 
-struct VerifyKeyData {
+struct [[nodiscard]] VerifyKeyData {
   std::vector<unsigned char> private_key;
   std::string public_key_base64;
   std::string key_id;