Add some const qualifiers

(Implementing suggestions of sudden6)

2 files changed, 80 insertions, 82 deletions

diff --git a/toxcore/group.c b/toxcore/group.c
index d0609b1a..101c1196 100644
--- a/toxcore/group.c
+++ b/toxcore/group.c
@@ -251,7 +251,7 @@ int32_t conference_by_id(const Group_Chats *g_c, const uint8_t *id)
  *
  * TODO(irungentoo): make this more efficient.
  */
-static int get_peer_index(Group_c *g, uint16_t peer_number)
+static int get_peer_index(const Group_c *g, uint16_t peer_number)
 {
     for (uint32_t i = 0; i < g->numpeers; ++i) {
         if (g->group[i].peer_number == peer_number) {
@@ -283,7 +283,6 @@ typedef enum Groupchat_Closest {
 
 static int add_to_closest(Group_Chats *g_c, uint32_t groupnumber, const uint8_t *real_pk, const uint8_t *temp_pk)
 {
-    // TODO(zugz): this can be const. Similarly throughout the file.
     Group_c *g = get_group_c(g_c, groupnumber);
 
     if (!g) {
@@ -365,7 +364,7 @@ static int add_to_closest(Group_Chats *g_c, uint32_t groupnumber, const uint8_t
     return 0;
 }
 
-static unsigned int pk_in_closest_peers(Group_c *g, uint8_t *real_pk)
+static unsigned int pk_in_closest_peers(const Group_c *g, uint8_t *real_pk)
 {
     unsigned int i;
 
@@ -388,7 +387,7 @@ static int add_conn_to_groupchat(Group_Chats *g_c, int friendcon_id, uint32_t gr
 static void remove_conn_reason(Group_Chats *g_c, uint32_t groupnumber, uint16_t i, uint8_t reason);
 
 static int send_packet_online(Friend_Connections *fr_c, int friendcon_id, uint16_t group_num, uint8_t type,
-                              uint8_t *id);
+                              const uint8_t *id);
 
 static int connect_to_closest(Group_Chats *g_c, uint32_t groupnumber, void *userdata)
 {
@@ -458,7 +457,7 @@ static int connect_to_closest(Group_Chats *g_c, uint32_t groupnumber, void *user
     return 0;
 }
 
-static int get_frozen_index(Group_c *g, uint16_t peer_number)
+static int get_frozen_index(const Group_c *g, uint16_t peer_number)
 {
     for (uint32_t i = 0; i < g->numfrozen; ++i) {
         if (g->frozen[i].peer_number == peer_number) {
@@ -485,7 +484,7 @@ static bool delete_frozen(Group_c *g, uint32_t frozen_index)
             g->frozen[frozen_index] = g->frozen[g->numfrozen];
         }
 
-        Group_Peer *frozen_temp = (Group_Peer *)realloc(g->frozen, sizeof(Group_Peer) * (g->numfrozen));
+        Group_Peer *const frozen_temp = (Group_Peer *)realloc(g->frozen, sizeof(Group_Peer) * (g->numfrozen));
 
         if (frozen_temp == nullptr) {
             return false;
@@ -567,13 +566,13 @@ static void delete_any_peer_with_pk(Group_Chats *g_c, uint32_t groupnumber, cons
         return;
     }
 
-    int prev_peer_index = peer_in_chat(g, real_pk);
+    const int prev_peer_index = peer_in_chat(g, real_pk);
 
     if (prev_peer_index >= 0) {
         delpeer(g_c, groupnumber, prev_peer_index, userdata, false);
     }
 
-    int prev_frozen_index = frozen_in_chat(g, real_pk);
+    const int prev_frozen_index = frozen_in_chat(g, real_pk);
 
     if (prev_frozen_index >= 0) {
         delete_frozen(g, prev_frozen_index);
@@ -1139,7 +1138,7 @@ int del_groupchat(Group_Chats *g_c, uint32_t groupnumber, bool leave_permanently
  */
 int group_peer_pubkey(const Group_Chats *g_c, uint32_t groupnumber, int peernumber, uint8_t *pk, bool frozen)
 {
-    Group_c *g = get_group_c(g_c, groupnumber);
+    const Group_c *g = get_group_c(g_c, groupnumber);
 
     if (!g) {
         return -1;
@@ -1164,7 +1163,7 @@ int group_peer_pubkey(const Group_Chats *g_c, uint32_t groupnumber, int peernumb
  */
 int group_peername_size(const Group_Chats *g_c, uint32_t groupnumber, int peernumber, bool frozen)
 {
-    Group_c *g = get_group_c(g_c, groupnumber);
+    const Group_c *g = get_group_c(g_c, groupnumber);
 
     if (!g) {
         return -1;
@@ -1193,7 +1192,7 @@ int group_peername_size(const Group_Chats *g_c, uint32_t groupnumber, int peernu
  */
 int group_peername(const Group_Chats *g_c, uint32_t groupnumber, int peernumber, uint8_t *name, bool frozen)
 {
-    Group_c *g = get_group_c(g_c, groupnumber);
+    const Group_c *g = get_group_c(g_c, groupnumber);
 
     if (!g) {
         return -1;
@@ -1224,7 +1223,7 @@ int group_peername(const Group_Chats *g_c, uint32_t groupnumber, int peernumber,
 int group_frozen_last_active(const Group_Chats *g_c, uint32_t groupnumber, int peernumber,
                              uint64_t *last_active)
 {
-    Group_c *g = get_group_c(g_c, groupnumber);
+    const Group_c *g = get_group_c(g_c, groupnumber);
 
     if (!g) {
         return -1;
@@ -1251,7 +1250,7 @@ int group_frozen_last_active(const Group_Chats *g_c, uint32_t groupnumber, int p
 int group_names(const Group_Chats *g_c, uint32_t groupnumber, uint8_t names[][MAX_NAME_LENGTH], uint16_t lengths[],
                 uint16_t length, bool frozen)
 {
-    Group_c *g = get_group_c(g_c, groupnumber);
+    const Group_c *g = get_group_c(g_c, groupnumber);
 
     if (!g) {
         return -1;
@@ -1274,7 +1273,7 @@ int group_names(const Group_Chats *g_c, uint32_t groupnumber, uint8_t names[][MA
  */
 int group_number_peers(const Group_Chats *g_c, uint32_t groupnumber, bool frozen)
 {
-    Group_c *g = get_group_c(g_c, groupnumber);
+    const Group_c *g = get_group_c(g_c, groupnumber);
 
     if (!g) {
         return -1;
@@ -1291,7 +1290,7 @@ int group_number_peers(const Group_Chats *g_c, uint32_t groupnumber, bool frozen
  */
 int group_peernumber_is_ours(const Group_Chats *g_c, uint32_t groupnumber, int peernumber)
 {
-    Group_c *g = get_group_c(g_c, groupnumber);
+    const Group_c *g = get_group_c(g_c, groupnumber);
 
     if (!g) {
         return -1;
@@ -1712,7 +1711,7 @@ static int group_name_send(const Group_Chats *g_c, uint32_t groupnumber, const u
  */
 static bool group_leave(const Group_Chats *g_c, uint32_t groupnumber, bool permanent)
 {
-    Group_c *g = get_group_c(g_c, groupnumber);
+    const Group_c *g = get_group_c(g_c, groupnumber);
 
     if (!g) {
         return false;
@@ -1769,7 +1768,7 @@ int group_title_send(const Group_Chats *g_c, uint32_t groupnumber, const uint8_t
  */
 int group_title_get_size(const Group_Chats *g_c, uint32_t groupnumber)
 {
-    Group_c *g = get_group_c(g_c, groupnumber);
+    const Group_c *g = get_group_c(g_c, groupnumber);
 
     if (!g) {
         return -1;
@@ -1791,7 +1790,7 @@ int group_title_get_size(const Group_Chats *g_c, uint32_t groupnumber)
  */
 int group_title_get(const Group_Chats *g_c, uint32_t groupnumber, uint8_t *title)
 {
-    Group_c *g = get_group_c(g_c, groupnumber);
+    const Group_c *g = get_group_c(g_c, groupnumber);
 
     if (!g) {
         return -1;
@@ -1929,7 +1928,7 @@ static void handle_friend_invite_packet(Messenger *m, uint32_t friendnumber, con
  * returns index on success
  * returns -1 on failure.
  */
-static int friend_in_close(Group_c *g, int friendcon_id)
+static int friend_in_close(const Group_c *g, int friendcon_id)
 {
     unsigned int i;
 
@@ -1950,7 +1949,7 @@ static int friend_in_close(Group_c *g, int friendcon_id)
 
 /* return number of connected close connections.
  */
-static unsigned int count_close_connected(Group_c *g)
+static unsigned int count_close_connected(const Group_c *g)
 {
     unsigned int i, count = 0;
 
@@ -1964,7 +1963,7 @@ static unsigned int count_close_connected(Group_c *g)
 }
 
 static int send_packet_online(Friend_Connections *fr_c, int friendcon_id, uint16_t group_num, uint8_t type,
-                              uint8_t *id)
+                              const uint8_t *id)
 {
     uint8_t packet[1 + ONLINE_PACKET_DATA_SIZE];
     group_num = net_htons(group_num);
@@ -2045,7 +2044,7 @@ static int handle_packet_rejoin(Group_Chats *g_c, int friendcon_id, const uint8_
 
     const int32_t groupnum = get_group_num(g_c, *data, data + 1);
 
-    Group_c *g = get_group_c(g_c, groupnum);
+    const Group_c *g = get_group_c(g_c, groupnum);
 
     if (!g) {
         return -1;
@@ -2099,7 +2098,7 @@ static unsigned int send_peer_query(Group_Chats *g_c, int friendcon_id, uint16_t
  */
 static unsigned int send_peers(Group_Chats *g_c, uint32_t groupnumber, int friendcon_id, uint16_t group_num)
 {
-    Group_c *g = get_group_c(g_c, groupnumber);
+    const Group_c *g = get_group_c(g_c, groupnumber);
 
     if (!g) {
         return 0;
@@ -2222,7 +2221,7 @@ static void handle_direct_packet(Group_Chats *g_c, uint32_t groupnumber, const u
 
     switch (data[0]) {
         case PEER_INTRODUCED_ID: {
-            Group_c *g = get_group_c(g_c, groupnumber);
+            const Group_c *g = get_group_c(g_c, groupnumber);
 
             if (!g) {
                 return;
@@ -2234,7 +2233,7 @@ static void handle_direct_packet(Group_Chats *g_c, uint32_t groupnumber, const u
         break;
 
         case PEER_QUERY_ID: {
-            Group_c *g = get_group_c(g_c, groupnumber);
+            const Group_c *g = get_group_c(g_c, groupnumber);
 
             if (!g) {
                 return;
@@ -2256,7 +2255,7 @@ static void handle_direct_packet(Group_Chats *g_c, uint32_t groupnumber, const u
         break;
 
         case PEER_TITLE_ID: {
-            Group_c *g = get_group_c(g_c, groupnumber);
+            const Group_c *g = get_group_c(g_c, groupnumber);
 
             if (!g) {
                 break;
@@ -2279,7 +2278,7 @@ static void handle_direct_packet(Group_Chats *g_c, uint32_t groupnumber, const u
 static unsigned int send_message_all_close(const Group_Chats *g_c, uint32_t groupnumber, const uint8_t *data,
         uint16_t length, int receiver)
 {
-    Group_c *g = get_group_c(g_c, groupnumber);
+    const Group_c *g = get_group_c(g_c, groupnumber);
 
     if (!g) {
         return 0;
@@ -2314,7 +2313,7 @@ static unsigned int send_lossy_all_close(const Group_Chats *g_c, uint32_t groupn
         uint16_t length,
         int receiver)
 {
-    Group_c *g = get_group_c(g_c, groupnumber);
+    const Group_c *g = get_group_c(g_c, groupnumber);
 
     if (!g) {
         return 0;
@@ -2561,7 +2560,7 @@ static void handle_message_packet_group(Group_Chats *g_c, uint32_t groupnumber,
         return;
     }
 
-    Group_c *g = get_group_c(g_c, groupnumber);
+    const Group_c *g = get_group_c(g_c, groupnumber);
 
     if (!g) {
         return;
@@ -2741,7 +2740,7 @@ static int g_handle_packet(void *object, int friendcon_id, const uint8_t *data,
     uint16_t groupnumber;
     memcpy(&groupnumber, data + 1, sizeof(uint16_t));
     groupnumber = net_ntohs(groupnumber);
-    Group_c *g = get_group_c(g_c, groupnumber);
+    const Group_c *g = get_group_c(g_c, groupnumber);
 
     if (!g) {
         return -1;
@@ -2781,7 +2780,7 @@ static int g_handle_packet(void *object, int friendcon_id, const uint8_t *data,
  *
  * TODO(irungentoo): test this
  */
-static unsigned int lossy_packet_not_received(Group_c *g, int peer_index, uint16_t message_number)
+static unsigned int lossy_packet_not_received(const Group_c *g, int peer_index, uint16_t message_number)
 {
     if (peer_index == -1) {
         // TODO(sudden6): invalid return value
@@ -2852,7 +2851,7 @@ static int handle_lossy(void *object, int friendcon_id, const uint8_t *data, uin
     peer_number = net_ntohs(peer_number);
     message_number = net_ntohs(message_number);
 
-    Group_c *g = get_group_c(g_c, groupnumber);
+    const Group_c *g = get_group_c(g_c, groupnumber);
 
     if (!g) {
         return -1;
@@ -2921,7 +2920,7 @@ int group_set_object(const Group_Chats *g_c, uint32_t groupnumber, void *object)
  */
 int group_peer_set_object(const Group_Chats *g_c, uint32_t groupnumber, int peernumber, void *object)
 {
-    Group_c *g = get_group_c(g_c, groupnumber);
+    const Group_c *g = get_group_c(g_c, groupnumber);
 
     if (!g) {
         return -1;
@@ -2942,7 +2941,7 @@ int group_peer_set_object(const Group_Chats *g_c, uint32_t groupnumber, int peer
  */
 void *group_get_object(const Group_Chats *g_c, uint32_t groupnumber)
 {
-    Group_c *g = get_group_c(g_c, groupnumber);
+    const Group_c *g = get_group_c(g_c, groupnumber);
 
     if (!g) {
         return nullptr;
@@ -2958,7 +2957,7 @@ void *group_get_object(const Group_Chats *g_c, uint32_t groupnumber)
  */
 void *group_peer_get_object(const Group_Chats *g_c, uint32_t groupnumber, int peernumber)
 {
-    Group_c *g = get_group_c(g_c, groupnumber);
+    const Group_c *g = get_group_c(g_c, groupnumber);
 
     if (!g) {
         return nullptr;
@@ -3101,7 +3100,7 @@ static uint8_t *save_conf(const Group_c *g, uint8_t *data)
     host_to_lendian_bytes16(data, g->peer_number);
     data += sizeof(uint16_t);
 
-    uint8_t *numsaved_location = data;
+    uint8_t *const numsaved_location = data;
     data += sizeof(uint32_t);
 
     *data = g->title_len;
@@ -3133,7 +3132,7 @@ static uint32_t conferences_section_size(const Group_Chats *g_c)
     uint32_t len = 0;
 
     for (uint16_t i = 0; i < g_c->num_chats; ++i) {
-        Group_c *g = get_group_c(g_c, i);
+        const Group_c *g = get_group_c(g_c, i);
 
         if (!g || g->status != GROUPCHAT_STATUS_CONNECTED) {
             continue;
@@ -3156,7 +3155,7 @@ uint8_t *conferences_save(const Group_Chats *g_c, uint8_t *data)
     data = state_write_section_header(data, STATE_COOKIE_TYPE, len, STATE_TYPE_CONFERENCES);
 
     for (uint16_t i = 0; i < g_c->num_chats; ++i) {
-        Group_c *g = get_group_c(g_c, i);
+        const Group_c *g = get_group_c(g_c, i);
 
         if (!g || g->status != GROUPCHAT_STATUS_CONNECTED) {
             continue;
diff --git a/toxcore/tox.c b/toxcore/tox.c
index d848102e..d59094af 100644
--- a/toxcore/tox.c
+++ b/toxcore/tox.c
@@ -330,7 +330,7 @@ bool tox_version_is_compatible(uint32_t major, uint32_t minor, uint32_t patch)
 
 static State_Load_Status state_load_callback(void *outer, const uint8_t *data, uint32_t length, uint16_t type)
 {
-    Tox *tox = (Tox *)outer;
+    const Tox *tox = (const Tox *)outer;
     State_Load_Status status = STATE_LOAD_STATUS_CONTINUE;
 
     if (messenger_load_state_section(tox->m, data, length, type, &status)
@@ -356,7 +356,7 @@ static State_Load_Status state_load_callback(void *outer, const uint8_t *data, u
 static int tox_load(Tox *tox, const uint8_t *data, uint32_t length)
 {
     uint32_t data32[2];
-    uint32_t cookie_len = sizeof(data32);
+    const uint32_t cookie_len = sizeof(data32);
 
     if (length < cookie_len) {
         return -1;
@@ -637,7 +637,7 @@ bool tox_bootstrap(Tox *tox, const char *host, uint16_t port, const uint8_t *pub
 
     IP_Port *root;
 
-    int32_t count = net_getipport(host, &root, TOX_SOCK_DGRAM);
+    const int32_t count = net_getipport(host, &root, TOX_SOCK_DGRAM);
 
     if (count == -1) {
         net_freeipport(root);
@@ -713,8 +713,7 @@ Tox_Connection tox_self_get_connection_status(const Tox *tox)
 {
     const Messenger *m = tox->m;
 
-    // TODO(zugz): this can be const. Similarly throughout the file.
-    unsigned int ret = onion_connection_status(m->onion_c);
+    const unsigned int ret = onion_connection_status(m->onion_c);
 
     if (ret == 2) {
         return TOX_CONNECTION_UDP;
@@ -913,7 +912,7 @@ uint32_t tox_friend_add(Tox *tox, const uint8_t *address, const uint8_t *message
     }
 
     Messenger *m = tox->m;
-    int32_t ret = m_addfriend(m, address, message, length);
+    const int32_t ret = m_addfriend(m, address, message, length);
 
     if (ret >= 0) {
         SET_ERROR_PARAMETER(error, TOX_ERR_FRIEND_ADD_OK);
@@ -932,7 +931,7 @@ uint32_t tox_friend_add_norequest(Tox *tox, const uint8_t *public_key, Tox_Err_F
     }
 
     Messenger *m = tox->m;
-    int32_t ret = m_addfriend_norequest(m, public_key);
+    const int32_t ret = m_addfriend_norequest(m, public_key);
 
     if (ret >= 0) {
         SET_ERROR_PARAMETER(error, TOX_ERR_FRIEND_ADD_OK);
@@ -946,7 +945,7 @@ uint32_t tox_friend_add_norequest(Tox *tox, const uint8_t *public_key, Tox_Err_F
 bool tox_friend_delete(Tox *tox, uint32_t friend_number, Tox_Err_Friend_Delete *error)
 {
     Messenger *m = tox->m;
-    int ret = m_delfriend(m, friend_number);
+    const int ret = m_delfriend(m, friend_number);
 
     // TODO(irungentoo): handle if realloc fails?
     if (ret == -1) {
@@ -966,7 +965,7 @@ uint32_t tox_friend_by_public_key(const Tox *tox, const uint8_t *public_key, Tox
     }
 
     const Messenger *m = tox->m;
-    int32_t ret = getfriend_id(m, public_key);
+    const int32_t ret = getfriend_id(m, public_key);
 
     if (ret == -1) {
         SET_ERROR_PARAMETER(error, TOX_ERR_FRIEND_BY_PUBLIC_KEY_NOT_FOUND);
@@ -1004,7 +1003,7 @@ bool tox_friend_exists(const Tox *tox, uint32_t friend_number)
 uint64_t tox_friend_get_last_online(const Tox *tox, uint32_t friend_number, Tox_Err_Friend_Get_Last_Online *error)
 {
     const Messenger *m = tox->m;
-    uint64_t timestamp = m_get_last_online(m, friend_number);
+    const uint64_t timestamp = m_get_last_online(m, friend_number);
 
     if (timestamp == UINT64_MAX) {
         SET_ERROR_PARAMETER(error, TOX_ERR_FRIEND_GET_LAST_ONLINE_FRIEND_NOT_FOUND);
@@ -1033,7 +1032,7 @@ void tox_self_get_friend_list(const Tox *tox, uint32_t *friend_list)
 size_t tox_friend_get_name_size(const Tox *tox, uint32_t friend_number, Tox_Err_Friend_Query *error)
 {
     const Messenger *m = tox->m;
-    int ret = m_get_name_size(m, friend_number);
+    const int ret = m_get_name_size(m, friend_number);
 
     if (ret == -1) {
         SET_ERROR_PARAMETER(error, TOX_ERR_FRIEND_QUERY_FRIEND_NOT_FOUND);
@@ -1052,7 +1051,7 @@ bool tox_friend_get_name(const Tox *tox, uint32_t friend_number, uint8_t *name,
     }
 
     const Messenger *m = tox->m;
-    int ret = getname(m, friend_number, name);
+    const int ret = getname(m, friend_number, name);
 
     if (ret == -1) {
         SET_ERROR_PARAMETER(error, TOX_ERR_FRIEND_QUERY_FRIEND_NOT_FOUND);
@@ -1071,7 +1070,7 @@ void tox_callback_friend_name(Tox *tox, tox_friend_name_cb *callback)
 size_t tox_friend_get_status_message_size(const Tox *tox, uint32_t friend_number, Tox_Err_Friend_Query *error)
 {
     const Messenger *m = tox->m;
-    int ret = m_get_statusmessage_size(m, friend_number);
+    const int ret = m_get_statusmessage_size(m, friend_number);
 
     if (ret == -1) {
         SET_ERROR_PARAMETER(error, TOX_ERR_FRIEND_QUERY_FRIEND_NOT_FOUND);
@@ -1114,7 +1113,7 @@ Tox_User_Status tox_friend_get_status(const Tox *tox, uint32_t friend_number, To
 {
     const Messenger *m = tox->m;
 
-    int ret = m_get_userstatus(m, friend_number);
+    const int ret = m_get_userstatus(m, friend_number);
 
     if (ret == USERSTATUS_INVALID) {
         SET_ERROR_PARAMETER(error, TOX_ERR_FRIEND_QUERY_FRIEND_NOT_FOUND);
@@ -1134,7 +1133,7 @@ Tox_Connection tox_friend_get_connection_status(const Tox *tox, uint32_t friend_
 {
     const Messenger *m = tox->m;
 
-    int ret = m_get_friend_connectionstatus(m, friend_number);
+    const int ret = m_get_friend_connectionstatus(m, friend_number);
 
     if (ret == -1) {
         SET_ERROR_PARAMETER(error, TOX_ERR_FRIEND_QUERY_FRIEND_NOT_FOUND);
@@ -1153,7 +1152,7 @@ void tox_callback_friend_connection_status(Tox *tox, tox_friend_connection_statu
 bool tox_friend_get_typing(const Tox *tox, uint32_t friend_number, Tox_Err_Friend_Query *error)
 {
     const Messenger *m = tox->m;
-    int ret = m_get_istyping(m, friend_number);
+    const int ret = m_get_istyping(m, friend_number);
 
     if (ret == -1) {
         SET_ERROR_PARAMETER(error, TOX_ERR_FRIEND_QUERY_FRIEND_NOT_FOUND);
@@ -1264,7 +1263,7 @@ bool tox_file_control(Tox *tox, uint32_t friend_number, uint32_t file_number, To
                       Tox_Err_File_Control *error)
 {
     Messenger *m = tox->m;
-    int ret = file_control(m, friend_number, file_number, control);
+    const int ret = file_control(m, friend_number, file_number, control);
 
     if (ret == 0) {
         SET_ERROR_PARAMETER(error, TOX_ERR_FILE_CONTROL_OK);
@@ -1313,7 +1312,7 @@ bool tox_file_seek(Tox *tox, uint32_t friend_number, uint32_t file_number, uint6
                    Tox_Err_File_Seek *error)
 {
     Messenger *m = tox->m;
-    int ret = file_seek(m, friend_number, file_number, position);
+    const int ret = file_seek(m, friend_number, file_number, position);
 
     if (ret == 0) {
         SET_ERROR_PARAMETER(error, TOX_ERR_FILE_SEEK_OK);
@@ -1365,7 +1364,7 @@ bool tox_file_get_file_id(const Tox *tox, uint32_t friend_number, uint32_t file_
     }
 
     const Messenger *m = tox->m;
-    int ret = file_get_id(m, friend_number, file_number, file_id);
+    const int ret = file_get_id(m, friend_number, file_number, file_id);
 
     if (ret == 0) {
         SET_ERROR_PARAMETER(error, TOX_ERR_FILE_GET_OK);
@@ -1398,7 +1397,7 @@ uint32_t tox_file_send(Tox *tox, uint32_t friend_number, uint32_t kind, uint64_t
     }
 
     Messenger *m = tox->m;
-    long int file_num = new_filesender(m, friend_number, kind, file_size, file_id, filename, filename_length);
+    const long int file_num = new_filesender(m, friend_number, kind, file_size, file_id, filename, filename_length);
 
     if (file_num >= 0) {
         SET_ERROR_PARAMETER(error, TOX_ERR_FILE_SEND_OK);
@@ -1431,7 +1430,7 @@ bool tox_file_send_chunk(Tox *tox, uint32_t friend_number, uint32_t file_number,
                          size_t length, Tox_Err_File_Send_Chunk *error)
 {
     Messenger *m = tox->m;
-    int ret = file_data(m, friend_number, file_number, position, data, length);
+    const int ret = file_data(m, friend_number, file_number, position, data, length);
 
     if (ret == 0) {
         SET_ERROR_PARAMETER(error, TOX_ERR_FILE_SEND_CHUNK_OK);
@@ -1520,7 +1519,7 @@ void tox_callback_conference_peer_list_changed(Tox *tox, tox_conference_peer_lis
 uint32_t tox_conference_new(Tox *tox, Tox_Err_Conference_New *error)
 {
     Messenger *m = tox->m;
-    int ret = add_groupchat(m->conferences_object, GROUPCHAT_TYPE_TEXT);
+    const int ret = add_groupchat(m->conferences_object, GROUPCHAT_TYPE_TEXT);
 
     if (ret == -1) {
         SET_ERROR_PARAMETER(error, TOX_ERR_CONFERENCE_NEW_INIT);
@@ -1534,7 +1533,7 @@ uint32_t tox_conference_new(Tox *tox, Tox_Err_Conference_New *error)
 bool tox_conference_delete(Tox *tox, uint32_t conference_number, Tox_Err_Conference_Delete *error)
 {
     Messenger *m = tox->m;
-    int ret = del_groupchat(m->conferences_object, conference_number, true);
+    const int ret = del_groupchat(m->conferences_object, conference_number, true);
 
     if (ret == -1) {
         SET_ERROR_PARAMETER(error, TOX_ERR_CONFERENCE_DELETE_CONFERENCE_NOT_FOUND);
@@ -1548,7 +1547,7 @@ bool tox_conference_delete(Tox *tox, uint32_t conference_number, Tox_Err_Confere
 uint32_t tox_conference_peer_count(const Tox *tox, uint32_t conference_number, Tox_Err_Conference_Peer_Query *error)
 {
     const Messenger *m = tox->m;
-    int ret = group_number_peers(m->conferences_object, conference_number, false);
+    const int ret = group_number_peers(m->conferences_object, conference_number, false);
 
     if (ret == -1) {
         SET_ERROR_PARAMETER(error, TOX_ERR_CONFERENCE_PEER_QUERY_CONFERENCE_NOT_FOUND);
@@ -1563,7 +1562,7 @@ size_t tox_conference_peer_get_name_size(const Tox *tox, uint32_t conference_num
         Tox_Err_Conference_Peer_Query *error)
 {
     const Messenger *m = tox->m;
-    int ret = group_peername_size(m->conferences_object, conference_number, peer_number, false);
+    const int ret = group_peername_size(m->conferences_object, conference_number, peer_number, false);
 
     switch (ret) {
         case -1:
@@ -1583,7 +1582,7 @@ bool tox_conference_peer_get_name(const Tox *tox, uint32_t conference_number, ui
                                   Tox_Err_Conference_Peer_Query *error)
 {
     const Messenger *m = tox->m;
-    int ret = group_peername(m->conferences_object, conference_number, peer_number, name, false);
+    const int ret = group_peername(m->conferences_object, conference_number, peer_number, name, false);
 
     switch (ret) {
         case -1:
@@ -1603,7 +1602,7 @@ bool tox_conference_peer_get_public_key(const Tox *tox, uint32_t conference_numb
                                         uint8_t *public_key, Tox_Err_Conference_Peer_Query *error)
 {
     const Messenger *m = tox->m;
-    int ret = group_peer_pubkey(m->conferences_object, conference_number, peer_number, public_key, false);
+    const int ret = group_peer_pubkey(m->conferences_object, conference_number, peer_number, public_key, false);
 
     switch (ret) {
         case -1:
@@ -1623,7 +1622,7 @@ bool tox_conference_peer_number_is_ours(const Tox *tox, uint32_t conference_numb
                                         Tox_Err_Conference_Peer_Query *error)
 {
     const Messenger *m = tox->m;
-    int ret = group_peernumber_is_ours(m->conferences_object, conference_number, peer_number);
+    const int ret = group_peernumber_is_ours(m->conferences_object, conference_number, peer_number);
 
     switch (ret) {
         case -1:
@@ -1647,7 +1646,7 @@ uint32_t tox_conference_offline_peer_count(const Tox *tox, uint32_t conference_n
         Tox_Err_Conference_Peer_Query *error)
 {
     const Messenger *m = tox->m;
-    int ret = group_number_peers(m->conferences_object, conference_number, true);
+    const int ret = group_number_peers(m->conferences_object, conference_number, true);
 
     if (ret == -1) {
         SET_ERROR_PARAMETER(error, TOX_ERR_CONFERENCE_PEER_QUERY_CONFERENCE_NOT_FOUND);
@@ -1663,7 +1662,7 @@ size_t tox_conference_offline_peer_get_name_size(const Tox *tox, uint32_t confer
         Tox_Err_Conference_Peer_Query *error)
 {
     const Messenger *m = tox->m;
-    int ret = group_peername_size(m->conferences_object, conference_number, offline_peer_number, true);
+    const int ret = group_peername_size(m->conferences_object, conference_number, offline_peer_number, true);
 
     switch (ret) {
         case -1:
@@ -1684,7 +1683,7 @@ bool tox_conference_offline_peer_get_name(const Tox *tox, uint32_t conference_nu
         Tox_Err_Conference_Peer_Query *error)
 {
     const Messenger *m = tox->m;
-    int ret = group_peername(m->conferences_object, conference_number, offline_peer_number, name, true);
+    const int ret = group_peername(m->conferences_object, conference_number, offline_peer_number, name, true);
 
     switch (ret) {
         case -1:
@@ -1705,7 +1704,7 @@ bool tox_conference_offline_peer_get_public_key(const Tox *tox, uint32_t confere
         uint8_t *public_key, Tox_Err_Conference_Peer_Query *error)
 {
     const Messenger *m = tox->m;
-    int ret = group_peer_pubkey(m->conferences_object, conference_number, offline_peer_number, public_key, true);
+    const int ret = group_peer_pubkey(m->conferences_object, conference_number, offline_peer_number, public_key, true);
 
     switch (ret) {
         case -1:
@@ -1727,7 +1726,7 @@ uint64_t tox_conference_offline_peer_get_last_active(const Tox *tox, uint32_t co
 {
     const Messenger *m = tox->m;
     uint64_t last_active = UINT64_MAX;
-    int ret = group_frozen_last_active(m->conferences_object, conference_number, offline_peer_number, &last_active);
+    const int ret = group_frozen_last_active(m->conferences_object, conference_number, offline_peer_number, &last_active);
 
     switch (ret) {
         case -1:
@@ -1747,7 +1746,7 @@ bool tox_conference_invite(Tox *tox, uint32_t friend_number, uint32_t conference
                            Tox_Err_Conference_Invite *error)
 {
     Messenger *m = tox->m;
-    int ret = invite_friend(m->conferences_object, friend_number, conference_number);
+    const int ret = invite_friend(m->conferences_object, friend_number, conference_number);
 
     switch (ret) {
         case -1:
@@ -1771,7 +1770,7 @@ uint32_t tox_conference_join(Tox *tox, uint32_t friend_number, const uint8_t *co
                              Tox_Err_Conference_Join *error)
 {
     Messenger *m = tox->m;
-    int ret = join_groupchat(m->conferences_object, friend_number, GROUPCHAT_TYPE_TEXT, cookie, length);
+    const int ret = join_groupchat(m->conferences_object, friend_number, GROUPCHAT_TYPE_TEXT, cookie, length);
 
     switch (ret) {
         case -1:
@@ -1840,7 +1839,7 @@ bool tox_conference_send_message(Tox *tox, uint32_t conference_number, Tox_Messa
 size_t tox_conference_get_title_size(const Tox *tox, uint32_t conference_number, Tox_Err_Conference_Title *error)
 {
     const Messenger *m = tox->m;
-    int ret = group_title_get_size(m->conferences_object, conference_number);
+    const int ret = group_title_get_size(m->conferences_object, conference_number);
 
     switch (ret) {
         case -1:
@@ -1860,7 +1859,7 @@ bool tox_conference_get_title(const Tox *tox, uint32_t conference_number, uint8_
                               Tox_Err_Conference_Title *error)
 {
     const Messenger *m = tox->m;
-    int ret = group_title_get(m->conferences_object, conference_number, title);
+    const int ret = group_title_get(m->conferences_object, conference_number, title);
 
     switch (ret) {
         case -1:
@@ -1880,7 +1879,7 @@ bool tox_conference_set_title(Tox *tox, uint32_t conference_number, const uint8_
                               Tox_Err_Conference_Title *error)
 {
     Messenger *m = tox->m;
-    int ret = group_title_send(m->conferences_object, conference_number, title, length);
+    const int ret = group_title_send(m->conferences_object, conference_number, title, length);
 
     switch (ret) {
         case -1:
@@ -1909,7 +1908,7 @@ size_t tox_conference_get_chatlist_size(const Tox *tox)
 void tox_conference_get_chatlist(const Tox *tox, uint32_t *chatlist)
 {
     const Messenger *m = tox->m;
-    size_t list_size = tox_conference_get_chatlist_size(tox);
+    const size_t list_size = tox_conference_get_chatlist_size(tox);
     copy_chatlist(m->conferences_object, chatlist, list_size);
 }
 
@@ -1917,7 +1916,7 @@ Tox_Conference_Type tox_conference_get_type(const Tox *tox, uint32_t conference_
         Tox_Err_Conference_Get_Type *error)
 {
     const Messenger *m = tox->m;
-    int ret = group_get_type(m->conferences_object, conference_number);
+    const int ret = group_get_type(m->conferences_object, conference_number);
 
     if (ret == -1) {
         SET_ERROR_PARAMETER(error, TOX_ERR_CONFERENCE_GET_TYPE_CONFERENCE_NOT_FOUND);
@@ -1946,7 +1945,7 @@ uint32_t tox_conference_by_id(const Tox *tox, const uint8_t *id, Tox_Err_Confere
         return UINT32_MAX;
     }
 
-    int32_t ret = conference_by_id(tox->m->conferences_object, id);
+    const int32_t ret = conference_by_id(tox->m->conferences_object, id);
 
     if (ret == -1) {
         SET_ERROR_PARAMETER(error, TOX_ERR_CONFERENCE_BY_ID_NOT_FOUND);
@@ -2031,7 +2030,7 @@ bool tox_friend_send_lossy_packet(Tox *tox, uint32_t friend_number, const uint8_
         return 0;
     }
 
-    int ret = m_send_custom_lossy_packet(m, friend_number, data, length);
+    const int ret = m_send_custom_lossy_packet(m, friend_number, data, length);
 
     set_custom_packet_error(ret, error);
 
@@ -2062,7 +2061,7 @@ bool tox_friend_send_lossless_packet(Tox *tox, uint32_t friend_number, const uin
         return 0;
     }
 
-    int ret = send_custom_lossless_packet(m, friend_number, data, length);
+    const int ret = send_custom_lossless_packet(m, friend_number, data, length);
 
     set_custom_packet_error(ret, error);
 
@@ -2089,7 +2088,7 @@ void tox_self_get_dht_id(const Tox *tox, uint8_t *dht_id)
 uint16_t tox_self_get_udp_port(const Tox *tox, Tox_Err_Get_Port *error)
 {
     const Messenger *m = tox->m;
-    uint16_t port = net_htons(net_port(m->net));
+    const uint16_t port = net_htons(net_port(m->net));
 
     if (port) {
         SET_ERROR_PARAMETER(error, TOX_ERR_GET_PORT_OK);