Fix a ton of pedantic compiler warnings.

70 files changed, 189 insertions, 201 deletions

diff --git a/src/base.cpp b/src/base.cpp
index 86261d0f8..594498d24 100644
--- a/src/base.cpp
+++ b/src/base.cpp
@@ -52,14 +52,14 @@ refcountbase::~refcountbase()
 {
 	if (refcount && ServerInstance)
 		ServerInstance->Logs.Log("CULLLIST", LOG_DEBUG, "refcountbase::~ @%p with refcount %d",
-			(void*)this, refcount);
+			static_cast<void*>(this), refcount);
 }
 
 usecountbase::~usecountbase()
 {
 	if (usecount && ServerInstance)
 		ServerInstance->Logs.Log("CULLLIST", LOG_DEBUG, "usecountbase::~ @%p with refcount %d",
-			(void*)this, usecount);
+			static_cast<void*>(this), usecount);
 }
 
 void ServiceProvider::RegisterService()
diff --git a/src/command_parse.cpp b/src/command_parse.cpp
index 8b96d60cc..c367271c4 100644
--- a/src/command_parse.cpp
+++ b/src/command_parse.cpp
@@ -148,7 +148,7 @@ CmdResult CommandParser::CallHandler(const std::string& commandname, const Comma
 					case CmdAccess::SERVER: // Only servers can execute.
 						bOkay = IS_SERVER(user);
 						break;
-				};
+				}
 			}
 			else
 			{
diff --git a/src/coremods/core_channel/cmd_topic.cpp b/src/coremods/core_channel/cmd_topic.cpp
index 605961007..67f951f6c 100644
--- a/src/coremods/core_channel/cmd_topic.cpp
+++ b/src/coremods/core_channel/cmd_topic.cpp
@@ -103,5 +103,5 @@ CmdResult CommandTopic::HandleLocal(LocalUser* user, const Params& parameters)
 void Topic::ShowTopic(LocalUser* user, Channel* chan)
 {
 	user->WriteNumeric(RPL_TOPIC, chan->name, chan->topic);
-	user->WriteNumeric(RPL_TOPICTIME, chan->name, chan->setby, (unsigned long)chan->topicset);
+	user->WriteNumeric(RPL_TOPICTIME, chan->name, chan->setby, chan->topicset);
 }
diff --git a/src/coremods/core_channel/invite.cpp b/src/coremods/core_channel/invite.cpp
index 7f23977c1..3b52726cb 100644
--- a/src/coremods/core_channel/invite.cpp
+++ b/src/coremods/core_channel/invite.cpp
@@ -95,7 +95,8 @@ void Invite::APIImpl::Create(LocalUser* user, Channel* chan, time_t timeout)
 		// Expired, don't bother
 		return;
 
-	ServerInstance->Logs.Log(MODNAME, LOG_DEBUG, "Invite::APIImpl::Create(): user=%s chan=%s timeout=%lu", user->uuid.c_str(), chan->name.c_str(), (unsigned long)timeout);
+	ServerInstance->Logs.Log(MODNAME, LOG_DEBUG, "Invite::APIImpl::Create(): user=%s chan=%s timeout=%lu",
+		user->uuid.c_str(), chan->name.c_str(), static_cast<unsigned long>(timeout));
 
 	Invite* inv = Find(user, chan);
 	if (inv)
@@ -104,7 +105,8 @@ void Invite::APIImpl::Create(LocalUser* user, Channel* chan, time_t timeout)
 		if (!inv->IsTimed())
 			return;
 
-		ServerInstance->Logs.Log(MODNAME, LOG_DEBUG, "Invite::APIImpl::Create(): changing expiration in %p", (void*) inv);
+		ServerInstance->Logs.Log(MODNAME, LOG_DEBUG, "Invite::APIImpl::Create(): changing expiration in %p",
+			static_cast<void*>(inv));
 		if (timeout == 0)
 		{
 			// Convert timed invite to non-expiring
@@ -128,7 +130,8 @@ void Invite::APIImpl::Create(LocalUser* user, Channel* chan, time_t timeout)
 
 		userext.Get(user, true)->invites.push_front(inv);
 		chanext.Get(chan, true)->invites.push_front(inv);
-		ServerInstance->Logs.Log(MODNAME, LOG_DEBUG, "Invite::APIImpl::Create(): created new Invite %p", (void*) inv);
+		ServerInstance->Logs.Log(MODNAME, LOG_DEBUG, "Invite::APIImpl::Create(): created new Invite %p",
+			static_cast<void*>(inv));
 	}
 }
 
@@ -176,7 +179,7 @@ Invite::Invite::Invite(LocalUser* u, Channel* c)
 Invite::Invite::~Invite()
 {
 	delete expiretimer;
-	ServerInstance->Logs.Log(MODNAME, LOG_DEBUG, "Invite::~ %p", (void*) this);
+	ServerInstance->Logs.Log(MODNAME, LOG_DEBUG, "Invite::~ %p", static_cast<void*>(this));
 }
 
 void Invite::Invite::Serialize(bool human, bool show_chans, std::string& out)
@@ -202,7 +205,7 @@ InviteExpireTimer::InviteExpireTimer(Invite::Invite* invite, time_t timeout)
 
 bool InviteExpireTimer::Tick(time_t currtime)
 {
-	ServerInstance->Logs.Log(MODNAME, LOG_DEBUG, "InviteExpireTimer::Tick(): expired %p", (void*) inv);
+	ServerInstance->Logs.Log(MODNAME, LOG_DEBUG, "InviteExpireTimer::Tick(): expired %p", static_cast<void*>(inv));
 	apiimpl->Destruct(inv);
 	return false;
 }
diff --git a/src/coremods/core_dns.cpp b/src/coremods/core_dns.cpp
index 8ac41866e..3b67ffee4 100644
--- a/src/coremods/core_dns.cpp
+++ b/src/coremods/core_dns.cpp
@@ -398,7 +398,7 @@ class MyManager : public Manager, public Timer, public EventHandler
 				cachettl = rr.ttl;
 		}
 
-		cachettl = std::min(cachettl, (unsigned int)5*60);
+		cachettl = std::min<unsigned int>(cachettl, 5*60);
 		ResourceRecord& rr = r.answers.front();
 		// Set TTL to what we've determined to be the lowest
 		rr.ttl = cachettl;
@@ -418,7 +418,7 @@ class MyManager : public Manager, public Timer, public EventHandler
 		ServerInstance->Timers.AddTimer(this);
 	}
 
-	~MyManager()
+	~MyManager() override
 	{
 		// Ensure Process() will fail for new requests
 		Close();
@@ -557,7 +557,6 @@ class MyManager : public Manager, public Timer, public EventHandler
 				return "DNS lookups are disabled";
 			case ERROR_NONE:
 			case ERROR_UNKNOWN:
-			default:
 				return "Unknown error";
 		}
 	}
diff --git a/src/coremods/core_lusers.cpp b/src/coremods/core_lusers.cpp
index 3e2b9260f..e93e5e17b 100644
--- a/src/coremods/core_lusers.cpp
+++ b/src/coremods/core_lusers.cpp
@@ -28,9 +28,9 @@
 
 struct LusersCounters
 {
-	unsigned int max_local;
-	unsigned int max_global;
-	unsigned int invisible = 0;
+	size_t max_local;
+	size_t max_global;
+	size_t invisible = 0;
 
 	LusersCounters(UserModeReference& invisiblemode)
 		: max_local(ServerInstance->Users.LocalUserCount())
@@ -47,7 +47,7 @@ struct LusersCounters
 
 	inline void UpdateMaxUsers()
 	{
-		unsigned int current = ServerInstance->Users.LocalUserCount();
+		size_t current = ServerInstance->Users.LocalUserCount();
 		if (current > max_local)
 			max_local = current;
 
@@ -80,11 +80,11 @@ class CommandLusers : public Command
  */
 CmdResult CommandLusers::Handle(User* user, const Params& parameters)
 {
-	unsigned int n_users = ServerInstance->Users.RegisteredUserCount();
+	size_t n_users = ServerInstance->Users.RegisteredUserCount();
 	ProtocolInterface::ServerList serverlist;
 	ServerInstance->PI->GetServerList(serverlist);
-	unsigned int n_serv = serverlist.size();
-	unsigned int n_local_servs = 0;
+	size_t n_serv = serverlist.size();
+	size_t n_local_servs = 0;
 	for (ProtocolInterface::ServerList::const_iterator i = serverlist.begin(); i != serverlist.end(); ++i)
 	{
 		if (i->parentname == ServerInstance->Config->ServerName)
@@ -96,10 +96,10 @@ CmdResult CommandLusers::Handle(User* user, const Params& parameters)
 
 	counters.UpdateMaxUsers();
 
-	user->WriteNumeric(RPL_LUSERCLIENT, InspIRCd::Format("There are %d users and %d invisible on %d servers",
+	user->WriteNumeric(RPL_LUSERCLIENT, InspIRCd::Format("There are %zu users and %zu invisible on %zu servers",
 			n_users - counters.invisible, counters.invisible, n_serv));
 
-	unsigned int opercount = ServerInstance->Users.all_opers.size();
+	size_t opercount = ServerInstance->Users.all_opers.size();
 	if (opercount)
 		user->WriteNumeric(RPL_LUSEROP, opercount, "operator(s) online");
 
@@ -107,19 +107,20 @@ CmdResult CommandLusers::Handle(User* user, const Params& parameters)
 		user->WriteNumeric(RPL_LUSERUNKNOWN, ServerInstance->Users.UnregisteredUserCount(), "unknown connections");
 
 	user->WriteNumeric(RPL_LUSERCHANNELS, ServerInstance->GetChans().size(), "channels formed");
-	user->WriteNumeric(RPL_LUSERME, InspIRCd::Format("I have %d clients and %d servers", ServerInstance->Users.LocalUserCount(), n_local_servs));
-	user->WriteNumeric(RPL_LOCALUSERS, InspIRCd::Format("Current local users: %d  Max: %d", ServerInstance->Users.LocalUserCount(), counters.max_local));
-	user->WriteNumeric(RPL_GLOBALUSERS, InspIRCd::Format("Current global users: %d  Max: %d", n_users, counters.max_global));
+	user->WriteNumeric(RPL_LUSERME, InspIRCd::Format("I have %zu clients and %zu servers", ServerInstance->Users.LocalUserCount(), n_local_servs));
+	user->WriteNumeric(RPL_LOCALUSERS, InspIRCd::Format("Current local users: %zu  Max: %zu", ServerInstance->Users.LocalUserCount(), counters.max_local));
+	user->WriteNumeric(RPL_GLOBALUSERS, InspIRCd::Format("Current global users: %zu  Max: %zu", n_users, counters.max_global));
 
 	return CmdResult::SUCCESS;
 }
 
 class InvisibleWatcher : public ModeWatcher
 {
-	unsigned int& invisible;
+	size_t& invisible;
 public:
-	InvisibleWatcher(Module* mod, unsigned int& Invisible)
-		: ModeWatcher(mod, "invisible", MODETYPE_USER), invisible(Invisible)
+	InvisibleWatcher(Module* mod, size_t& Invisible)
+		: ModeWatcher(mod, "invisible", MODETYPE_USER)
+		, invisible(Invisible)
 	{
 	}
 
diff --git a/src/coremods/core_mode.cpp b/src/coremods/core_mode.cpp
index 865bf2bcb..d65d3b45e 100644
--- a/src/coremods/core_mode.cpp
+++ b/src/coremods/core_mode.cpp
@@ -248,7 +248,7 @@ void CommandMode::DisplayCurrentModes(User* user, User* targetuser, Channel* tar
 		modenum.push(targetchannel->name);
 		GetModeList(modenum, targetchannel, user);
 		user->WriteNumeric(modenum);
-		user->WriteNumeric(RPL_CHANNELCREATED, targetchannel->name, (unsigned long)targetchannel->age);
+		user->WriteNumeric(RPL_CHANNELCREATED, targetchannel->name, targetchannel->age);
 	}
 	else
 	{
diff --git a/src/coremods/core_oper/cmd_die.cpp b/src/coremods/core_oper/cmd_die.cpp
index 6ef846018..a4887f192 100644
--- a/src/coremods/core_oper/cmd_die.cpp
+++ b/src/coremods/core_oper/cmd_die.cpp
@@ -62,12 +62,9 @@ CmdResult CommandDie::Handle(User* user, const Params& parameters)
 {
 	if (irc::equals(parameters[0], ServerInstance->Config->ServerName))
 	{
-		{
-			std::string diebuf = "*** DIE command from " + user->GetFullHost() + ". Terminating.";
-			ServerInstance->Logs.Log(MODNAME, LOG_SPARSE, diebuf);
-			DieRestart::SendError(diebuf);
-		}
-
+		const std::string diebuf = "*** DIE command from " + user->GetFullHost() + ". Terminating.";
+		ServerInstance->Logs.Log(MODNAME, LOG_SPARSE, diebuf);
+		DieRestart::SendError(diebuf);
 		ServerInstance->Exit(EXIT_STATUS_DIE);
 	}
 	else
@@ -76,5 +73,4 @@ CmdResult CommandDie::Handle(User* user, const Params& parameters)
 		ServerInstance->SNO.WriteGlobalSno('a', "Failed DIE command from %s.", user->GetFullRealHost().c_str());
 		return CmdResult::FAILURE;
 	}
-	return CmdResult::SUCCESS;
 }
diff --git a/src/coremods/core_reloadmodule.cpp b/src/coremods/core_reloadmodule.cpp
index 2f211767f..96fe48586 100644
--- a/src/coremods/core_reloadmodule.cpp
+++ b/src/coremods/core_reloadmodule.cpp
@@ -179,7 +179,7 @@ class DataKeeper
 	// Data saved for each user
 	struct UserData : public OwnedModesExts
 	{
-		static const size_t UNUSED_INDEX = (size_t)-1;
+		static const size_t UNUSED_INDEX = SIZE_MAX;
 		size_t serializerindex;
 
 		UserData(User* user, size_t serializeridx)
@@ -520,7 +520,7 @@ void DataKeeper::Save(Module* currmod)
 
 	reloadevprov->Call(&ReloadModule::EventListener::OnReloadModuleSave, mod, this->moddata);
 
-	ServerInstance->Logs.Log(MODNAME, LOG_DEBUG, "Saved data about %lu users %lu chans %lu modules", (unsigned long)userdatalist.size(), (unsigned long)chandatalist.size(), (unsigned long)moddata.list.size());
+	ServerInstance->Logs.Log(MODNAME, LOG_DEBUG, "Saved data about %zu users %zu chans %zu modules", userdatalist.size(), chandatalist.size(), moddata.list.size());
 }
 
 void DataKeeper::VerifyServiceProvider(const ProviderInfo& service, const char* type)
@@ -694,7 +694,7 @@ void DataKeeper::DoRestoreModules()
 	for (ReloadModule::CustomData::List::iterator i = moddata.list.begin(); i != moddata.list.end(); ++i)
 	{
 		ReloadModule::CustomData::Data& data = *i;
-		ServerInstance->Logs.Log(MODNAME, LOG_DEBUG, "Calling module data handler %p", (void*)data.handler);
+		ServerInstance->Logs.Log(MODNAME, LOG_DEBUG, "Calling module data handler %p", static_cast<void*>(data.handler));
 		data.handler->OnReloadModuleRestore(mod, data.data);
 	}
 }
diff --git a/src/coremods/core_whois.cpp b/src/coremods/core_whois.cpp
index a6ca4a2bc..fdfb0b6c6 100644
--- a/src/coremods/core_whois.cpp
+++ b/src/coremods/core_whois.cpp
@@ -315,7 +315,7 @@ CmdResult CommandWhois::HandleLocal(LocalUser* user, const Params& parameters)
 		LocalUser* localuser = IS_LOCAL(dest);
 		if (localuser && (ServerInstance->Config->HideServer.empty() || parameters.size() > 1))
 		{
-			idle = labs((long)((localuser->idle_lastmsg)-ServerInstance->Time()));
+			idle = std::max<unsigned long>(localuser->idle_lastmsg - ServerInstance->Time(), 0);
 			signon = dest->signon;
 		}
 
diff --git a/src/cull.cpp b/src/cull.cpp
index ed4b06c09..9a6665a29 100644
--- a/src/cull.cpp
+++ b/src/cull.cpp
@@ -35,7 +35,7 @@ Cullable::Cullable()
 	if (ServerInstance)
 	{
 		ServerInstance->Logs.Log("CULLLIST", LOG_DEBUG, "Cullable::+%s @%p",
-				typeid(*this).name(), (void*)this);
+				typeid(*this).name(), static_cast<void*>(this));
 	}
 #endif
 }
@@ -46,7 +46,7 @@ Cullable::~Cullable()
 	if (ServerInstance)
 	{
 		ServerInstance->Logs.Log("CULLLIST", LOG_DEBUG, "Cullable::~%s @%p",
-			typeid(*this).name(), (void*)this);
+			typeid(*this).name(), static_cast<void*>(this));
 	}
 #endif
 }
@@ -57,7 +57,7 @@ Cullable::Result Cullable::Cull()
 	if (ServerInstance)
 	{
 		ServerInstance->Logs.Log("CULLLIST", LOG_DEBUG, "Cullable::-%s @%p",
-			typeid(*this).name(), (void*)this);
+			typeid(*this).name(), static_cast<void*>(this));
 	}
 #endif
 	return Result();
@@ -88,9 +88,9 @@ void CullList::Apply()
 		{
 #ifdef INSPIRCD_ENABLE_RTTI
 			ServerInstance->Logs.Log("CULLLIST", LOG_DEBUG, "Deleting %s @%p", typeid(*c).name(),
-				(void*)c);
+				static_cast<void*>(c));
 #else
-			ServerInstance->Logs.Log("CULLLIST", LOG_DEBUG, "Deleting @%p", (void*)c);
+			ServerInstance->Logs.Log("CULLLIST", LOG_DEBUG, "Deleting @%p", static_cast<void*>(c));
 #endif
 			c->Cull();
 			queue.push_back(c);
@@ -98,7 +98,7 @@ void CullList::Apply()
 		else
 		{
 			ServerInstance->Logs.Log("CULLLIST", LOG_DEBUG, "WARNING: Object @%p culled twice!",
-				(void*)c);
+				static_cast<void*>(c));
 		}
 	}
 	list.clear();
diff --git a/src/extensible.cpp b/src/extensible.cpp
index bb236061d..88230ae9a 100644
--- a/src/extensible.cpp
+++ b/src/extensible.cpp
@@ -55,7 +55,10 @@ Extensible::Extensible()
 Extensible::~Extensible()
 {
 	if ((!extensions.empty() || !culled) && ServerInstance)
-		ServerInstance->Logs.Log("CULLLIST", LOG_DEBUG, "Extensible destructor called without cull @%p", (void*)this);
+	{
+		ServerInstance->Logs.Log("CULLLIST", LOG_DEBUG, "Extensible destructor called without cull @%p",
+			static_cast<void*>(this));
+	}
 }
 
 Cullable::Result Extensible::Cull()
@@ -137,15 +140,15 @@ void ExtensionItem::Sync(const Extensible* container, void* item)
 	switch (type)
 	{
 		case ExtensionItem::EXT_CHANNEL:
-			ServerInstance->PI->SendMetaData((Channel*)container, name, networkstr);
+			ServerInstance->PI->SendMetaData(static_cast<const Channel*>(container), name, networkstr);
 			break;
 
 		case ExtensionItem::EXT_MEMBERSHIP:
-			ServerInstance->PI->SendMetaData((Membership*)container, name, networkstr);
+			ServerInstance->PI->SendMetaData(static_cast<const Membership*>(container), name, networkstr);
 			break;
 
 		case ExtensionItem::EXT_USER:
-			ServerInstance->PI->SendMetaData((User*)container, name, networkstr);
+			ServerInstance->PI->SendMetaData(static_cast<const User*>(container), name, networkstr);
 			break;
 	}
 }
diff --git a/src/hashcomp.cpp b/src/hashcomp.cpp
index ff12328b3..37158bb06 100644
--- a/src/hashcomp.cpp
+++ b/src/hashcomp.cpp
@@ -89,8 +89,8 @@ unsigned const char ascii_case_insensitive_map[256] = {
 
 bool irc::equals(const std::string& s1, const std::string& s2)
 {
-	const unsigned char* n1 = (const unsigned char*)s1.c_str();
-	const unsigned char* n2 = (const unsigned char*)s2.c_str();
+	const unsigned char* n1 = reinterpret_cast<const unsigned char*>(s1.c_str());
+	const unsigned char* n2 = reinterpret_cast<const unsigned char*>(s2.c_str());
 	for (; *n1 && *n2; n1++, n2++)
 		if (national_case_insensitive_map[*n1] != national_case_insensitive_map[*n2])
 			return false;
@@ -111,7 +111,9 @@ size_t irc::find(const std::string& haystack, const std::string& needle)
 		bool found = true;
 		for (size_t npos = 0; npos < needle.length(); ++npos)
 		{
-			if (national_case_insensitive_map[(unsigned char)needle[npos]] != national_case_insensitive_map[(unsigned char)haystack[hpos + npos]])
+			unsigned char unpos = needle[npos];
+			unsigned char uhpos = haystack[hpos + npos];
+			if (national_case_insensitive_map[unpos] != national_case_insensitive_map[uhpos])
 			{
 				// Uh-oh, characters at the current haystack position don't match.
 				found = false;
@@ -131,15 +133,14 @@ size_t irc::find(const std::string& haystack, const std::string& needle)
 
 bool irc::insensitive_swo::operator()(const std::string& a, const std::string& b) const
 {
-	const unsigned char* charmap = national_case_insensitive_map;
 	std::string::size_type asize = a.size();
 	std::string::size_type bsize = b.size();
 	std::string::size_type maxsize = std::min(asize, bsize);
 
 	for (std::string::size_type i = 0; i < maxsize; i++)
 	{
-		unsigned char A = charmap[(unsigned char)a[i]];
-		unsigned char B = charmap[(unsigned char)b[i]];
+		unsigned char A = national_case_insensitive_map[static_cast<unsigned char>(a[i])];
+		unsigned char B = national_case_insensitive_map[static_cast<unsigned char>(b[i])];
 		if (A > B)
 			return false;
 		else if (A < B)
@@ -157,8 +158,8 @@ size_t irc::insensitive::operator()(const std::string &s) const
 	 * This avoids a copy to use hash<const char*>
 	 */
 	size_t t = 0;
-	for (std::string::const_iterator x = s.begin(); x != s.end(); ++x) /* ++x not x++, as its faster */
-		t = 5 * t + national_case_insensitive_map[(unsigned char)*x];
+	for (const auto& c : s)
+		t = 5 * t + national_case_insensitive_map[static_cast<unsigned char>(c)];
 	return t;
 }
 
diff --git a/src/helperfuncs.cpp b/src/helperfuncs.cpp
index 9e3f1d4e1..607f44a28 100644
--- a/src/helperfuncs.cpp
+++ b/src/helperfuncs.cpp
@@ -501,7 +501,7 @@ std::string InspIRCd::GenRandomStr(unsigned int length, bool printable)
 unsigned long InspIRCd::GenRandomInt(unsigned long max)
 {
 	unsigned long rv;
-	GenRandom((char*)&rv, sizeof(rv));
+	GenRandom(reinterpret_cast<char*>(&rv), sizeof(rv));
 	return rv % max;
 }
 
diff --git a/src/inspircd.cpp b/src/inspircd.cpp
index 526514329..a934a5b62 100644
--- a/src/inspircd.cpp
+++ b/src/inspircd.cpp
@@ -65,6 +65,7 @@ unsigned const char* national_case_insensitive_map = ascii_case_insensitive_map;
 
 namespace
 {
+	[[noreturn]]
 	void VoidSignalHandler(int);
 
 	// Warns a user running as root that they probably shouldn't.
@@ -309,7 +310,6 @@ namespace
 						<< con_bright << "Usage: " << con_reset << argv[0] << " [--config <file>] [--debug] [--nofork] [--nolog]" << std::endl
 						<< std::string(strlen(argv[0]) + 8, ' ') << "[--nopid] [--runasroot] [--version]" << std::endl;
 					ServerInstance->Exit(EXIT_STATUS_ARGV);
-					break;
 			}
 		}
 
diff --git a/src/inspsocket.cpp b/src/inspsocket.cpp
index 893bc304a..0f12aebbe 100644
--- a/src/inspsocket.cpp
+++ b/src/inspsocket.cpp
@@ -294,7 +294,7 @@ void StreamSocket::FlushSendQ(SendQueue& sq)
 				rv = SocketEngine::WriteV(this, iovecs, bufcount);
 			}
 
-			if (rv == (int)sq.bytes())
+			if (rv == static_cast<int>(sq.bytes()))
 			{
 				// it's our lucky day, everything got written out. Fast cleanup.
 				// This won't ever happen if the number of buffers got capped.
@@ -311,7 +311,7 @@ void StreamSocket::FlushSendQ(SendQueue& sq)
 				while (rv > 0 && !sq.empty())
 				{
 					const SendQueue::Element& front = sq.front();
-					if (front.length() <= (size_t)rv)
+					if (front.length() <= static_cast<size_t>(rv))
 					{
 						// this string got fully written out
 						rv -= front.length();
@@ -518,7 +518,7 @@ void StreamSocket::AddIOHook(IOHook* newhook)
 		return;
 	}
 
-	IOHookMiddle* lasthook;
+	IOHookMiddle* lasthook = nullptr;
 	while (curr)
 	{
 		lasthook = IOHookMiddle::ToMiddleHook(curr);
diff --git a/src/inspstring.cpp b/src/inspstring.cpp
index 3cbf06602..a94b46fac 100644
--- a/src/inspstring.cpp
+++ b/src/inspstring.cpp
@@ -50,7 +50,7 @@ std::string BinToBase64(const std::string& data_str, const char* table, char pad
 		table = b64table;
 
 	uint32_t buffer;
-	uint8_t* data = (uint8_t*)data_str.data();
+	const uint8_t* data = reinterpret_cast<const uint8_t*>(data_str.data());
 	std::string rv;
 	size_t i = 0;
 	while (i + 2 < data_str.length())
diff --git a/src/listmode.cpp b/src/listmode.cpp
index 7ecdc2eeb..42ba49114 100644
--- a/src/listmode.cpp
+++ b/src/listmode.cpp
@@ -40,7 +40,7 @@ void ListModeBase::DisplayList(User* user, Channel* channel)
 	{
 		for (ModeList::const_iterator it = cd->list.begin(); it != cd->list.end(); ++it)
 		{
-			user->WriteNumeric(listnumeric, channel->name, it->mask, it->setter, (unsigned long) it->time);
+			user->WriteNumeric(listnumeric, channel->name, it->mask, it->setter, it->time);
 		}
 	}
 	user->WriteNumeric(endoflistnumeric, channel->name, endofliststring);
diff --git a/src/modules.cpp b/src/modules.cpp
index 5ff3b8041..495d82930 100644
--- a/src/modules.cpp
+++ b/src/modules.cpp
@@ -209,19 +209,19 @@ void ModuleManager::Attach(Implementation* i, Module* mod, size_t sz)
 void ModuleManager::AttachAll(Module* mod)
 {
 	for (size_t i = 0; i != I_END; ++i)
-		Attach((Implementation)i, mod);
+		Attach(static_cast<Implementation>(i), mod);
 }
 
 void ModuleManager::DetachAll(Module* mod)
 {
 	for (size_t n = 0; n != I_END; ++n)
-		Detach((Implementation)n, mod);
+		Detach(static_cast<Implementation>(n), mod);
 }
 
 void ModuleManager::SetPriority(Module* mod, Priority s)
 {
 	for (size_t n = 0; n != I_END; ++n)
-		SetPriority(mod, (Implementation)n, s);
+		SetPriority(mod, static_cast<Implementation>(n), s);
 }
 
 bool ModuleManager::SetPriority(Module* mod, Implementation i, Priority s, Module* which)
@@ -608,7 +608,7 @@ void ModuleManager::DelService(ServiceProvider& item)
 		case SERVICE_MODE:
 			if (!ServerInstance->Modes.DelMode(static_cast<ModeHandler*>(&item)))
 				throw ModuleException("Mode "+std::string(item.name)+" does not exist.");
-			// Fall through
+			[[fallthrough]];
 		case SERVICE_DATA:
 		case SERVICE_IOHOOK:
 		{
diff --git a/src/modules/extra/m_geo_maxmind.cpp b/src/modules/extra/m_geo_maxmind.cpp
index e39e171a6..da045868d 100644
--- a/src/modules/extra/m_geo_maxmind.cpp
+++ b/src/modules/extra/m_geo_maxmind.cpp
@@ -156,7 +156,7 @@ class ModuleGeoMaxMind : public Module
 		memset(&geoapi.mmdb, 0, sizeof(geoapi.mmdb));
 	}
 
-	~ModuleGeoMaxMind()
+	~ModuleGeoMaxMind() override
 	{
 		MMDB_close(&geoapi.mmdb);
 	}
diff --git a/src/modules/extra/m_ldap.cpp b/src/modules/extra/m_ldap.cpp
index 09c9a3f6e..bfb1397cb 100644
--- a/src/modules/extra/m_ldap.cpp
+++ b/src/modules/extra/m_ldap.cpp
@@ -294,7 +294,7 @@ class LDAPService : public LDAPProvider, public SocketThread
 		Connect();
 	}
 
-	~LDAPService()
+	~LDAPService() override
 	{
 		this->LockQueue();
 
@@ -623,7 +623,7 @@ class ModuleLDAP : public Module
 	{
 	}
 
-	~ModuleLDAP()
+	~ModuleLDAP() override
 	{
 		for (ServiceMap::iterator i = LDAPServices.begin(); i != LDAPServices.end(); ++i)
 		{
diff --git a/src/modules/extra/m_mysql.cpp b/src/modules/extra/m_mysql.cpp
index 446bf730b..728f5a04a 100644
--- a/src/modules/extra/m_mysql.cpp
+++ b/src/modules/extra/m_mysql.cpp
@@ -140,7 +140,7 @@ class ModuleSQL : public Module
 
 	void init() override;
 	ModuleSQL();
-	~ModuleSQL();
+	~ModuleSQL() override;
 	void ReadConfig(ConfigStatus& status) override;
 	void OnUnloadModule(Module* mod) override;
 };
@@ -305,7 +305,7 @@ class SQLConnection : public SQL::Provider
 	{
 	}
 
-	~SQLConnection()
+	~SQLConnection() override
 	{
 		mysql_close(connection);
 	}
diff --git a/src/modules/extra/m_pgsql.cpp b/src/modules/extra/m_pgsql.cpp
index 368e5e363..baa22b999 100644
--- a/src/modules/extra/m_pgsql.cpp
+++ b/src/modules/extra/m_pgsql.cpp
@@ -207,7 +207,7 @@ class SQLConn : public SQL::Provider, public EventHandler
 		return this->EventHandler::Cull();
 	}
 
-	~SQLConn()
+	~SQLConn() override
 	{
 		SQL::Error err(SQL::BAD_DBID);
 		if (qinprog.c)
@@ -532,7 +532,7 @@ class ModulePgSQL : public Module
 	{
 	}
 
-	~ModulePgSQL()
+	~ModulePgSQL() override
 	{
 		delete retimer;
 		ClearAllConnections();
diff --git a/src/modules/extra/m_regex_pcre.cpp b/src/modules/extra/m_regex_pcre.cpp
index 4d51be31b..fca30b4bf 100644
--- a/src/modules/extra/m_regex_pcre.cpp
+++ b/src/modules/extra/m_regex_pcre.cpp
@@ -63,7 +63,7 @@ class PCREPattern final
 			throw Regex::Exception(pattern, error, erroroffset);
 	}
 
-	~PCREPattern()
+	~PCREPattern() override
 	{
 		pcre_free(regex);
 	}
diff --git a/src/modules/extra/m_regex_posix.cpp b/src/modules/extra/m_regex_posix.cpp
index 943f7cca4..be3c28093 100644
--- a/src/modules/extra/m_regex_posix.cpp
+++ b/src/modules/extra/m_regex_posix.cpp
@@ -57,7 +57,7 @@ class POSIXPattern final
 		throw Regex::Exception(pattern, std::string(&errormsg[0], errormsg.size()));
 	}
 
-	~POSIXPattern()
+	~POSIXPattern() override
 	{
 		regfree(&regex);
 	}
diff --git a/src/modules/extra/m_regex_tre.cpp b/src/modules/extra/m_regex_tre.cpp
index a0c901230..2285adaa6 100644
--- a/src/modules/extra/m_regex_tre.cpp
+++ b/src/modules/extra/m_regex_tre.cpp
@@ -64,7 +64,7 @@ class TREPattern final
 		throw Regex::Exception(pattern, std::string(&errormsg[0], errormsg.size()));
 	}
 
-	~TREPattern()
+	~TREPattern() override
 	{
 		regfree(&regex);
 	}
diff --git a/src/modules/extra/m_sqlite3.cpp b/src/modules/extra/m_sqlite3.cpp
index 3cd9713cb..2f3954a84 100644
--- a/src/modules/extra/m_sqlite3.cpp
+++ b/src/modules/extra/m_sqlite3.cpp
@@ -113,7 +113,7 @@ class SQLConn : public SQL::Provider
 		}
 	}
 
-	~SQLConn()
+	~SQLConn() override
 	{
 		if (conn)
 		{
@@ -237,7 +237,7 @@ class ModuleSQLite3 : public Module
 	{
 	}
 
-	~ModuleSQLite3()
+	~ModuleSQLite3() override
 	{
 		ClearConns();
 	}
diff --git a/src/modules/extra/m_ssl_gnutls.cpp b/src/modules/extra/m_ssl_gnutls.cpp
index 5557a3806..d4f33d819 100644
--- a/src/modules/extra/m_ssl_gnutls.cpp
+++ b/src/modules/extra/m_ssl_gnutls.cpp
@@ -1086,7 +1086,7 @@ class GnuTLSIOHookProvider : public SSLIOHookProvider
 		ServerInstance->Modules.AddService(*this);
 	}
 
-	~GnuTLSIOHookProvider()
+	~GnuTLSIOHookProvider() override
 	{
 		ServerInstance->Modules.DelService(*this);
 	}
@@ -1199,7 +1199,7 @@ class ModuleSSLGnuTLS : public Module
 		}
 	}
 
-	~ModuleSSLGnuTLS()
+	~ModuleSSLGnuTLS() override
 	{
 		ServerInstance->GenRandom = &InspIRCd::DefaultGenRandom;
 	}
diff --git a/src/modules/extra/m_ssl_mbedtls.cpp b/src/modules/extra/m_ssl_mbedtls.cpp
index 5282ee261..dd14ec080 100644
--- a/src/modules/extra/m_ssl_mbedtls.cpp
+++ b/src/modules/extra/m_ssl_mbedtls.cpp
@@ -818,7 +818,7 @@ class mbedTLSIOHookProvider : public SSLIOHookProvider
 		ServerInstance->Modules.AddService(*this);
 	}
 
-	~mbedTLSIOHookProvider()
+	~mbedTLSIOHookProvider() override
 	{
 		ServerInstance->Modules.DelService(*this);
 	}
diff --git a/src/modules/extra/m_ssl_openssl.cpp b/src/modules/extra/m_ssl_openssl.cpp
index d7e5e3782..2a0479e3e 100644
--- a/src/modules/extra/m_ssl_openssl.cpp
+++ b/src/modules/extra/m_ssl_openssl.cpp
@@ -869,7 +869,7 @@ class OpenSSLIOHookProvider : public SSLIOHookProvider
 		ServerInstance->Modules.AddService(*this);
 	}
 
-	~OpenSSLIOHookProvider()
+	~OpenSSLIOHookProvider() override
 	{
 		ServerInstance->Modules.DelService(*this);
 	}
@@ -952,7 +952,7 @@ class ModuleSSLOpenSSL : public Module
 		biomethods = OpenSSL::BIOMethod::alloc();
 	}
 
-	~ModuleSSLOpenSSL()
+	~ModuleSSLOpenSSL() override
 	{
 		BIO_meth_free(biomethods);
 	}
diff --git a/src/modules/extra/m_sslrehashsignal.cpp b/src/modules/extra/m_sslrehashsignal.cpp
index c50ea10f2..b911c6a43 100644
--- a/src/modules/extra/m_sslrehashsignal.cpp
+++ b/src/modules/extra/m_sslrehashsignal.cpp
@@ -36,7 +36,7 @@ class ModuleSSLRehashSignal : public Module
 	{
 	}
 
-	~ModuleSSLRehashSignal()
+	~ModuleSSLRehashSignal() override
 	{
 		signal(SIGUSR1, SIG_IGN);
 	}
diff --git a/src/modules/m_anticaps.cpp b/src/modules/m_anticaps.cpp
index 7c7dc8844..645b2b916 100644
--- a/src/modules/m_anticaps.cpp
+++ b/src/modules/m_anticaps.cpp
@@ -142,10 +142,6 @@ class AntiCapsMode : public ParamMode<AntiCapsMode, SimpleExtItem<AntiCapsSettin
 			case ACM_KICK_BAN:
 				out.append("kickban");
 				break;
-			default:
-				out.append("unknown~");
-				out.append(ConvToStr(acs->method));
-				break;
 		}
 		out.push_back(':');
 		out.append(ConvToStr(acs->minlen));
diff --git a/src/modules/m_bcrypt.cpp b/src/modules/m_bcrypt.cpp
index a47ce8f36..9f3c9f7d5 100644
--- a/src/modules/m_bcrypt.cpp
+++ b/src/modules/m_bcrypt.cpp
@@ -17,7 +17,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-/// $CompilerFlags: -Ivendor_directory("bcrypt")
+/// $CompilerFlags: -isystem vendor_directory("bcrypt")
 
 
 #include "inspircd.h"
diff --git a/src/modules/m_callerid.cpp b/src/modules/m_callerid.cpp
index 4a01b569c..887c8b337 100644
--- a/src/modules/m_callerid.cpp
+++ b/src/modules/m_callerid.cpp
@@ -423,7 +423,7 @@ public:
 			time_t now = ServerInstance->Time();
 			/* +g and *not* accepted */
 			user->WriteNumeric(ERR_TARGUMODEG, dest->nick, "is in +g mode (server-side ignore).");
-			if (now > (dat->lastnotify + (time_t)notify_cooldown))
+			if (now > (dat->lastnotify + notify_cooldown))
 			{
 				user->WriteNumeric(RPL_TARGNOTIFY, dest->nick, "has been informed that you messaged them.");
 				dest->WriteRemoteNumeric(RPL_UMODEGMSG, user->nick, InspIRCd::Format("%s@%s", user->ident.c_str(), user->GetDisplayedHost().c_str()), InspIRCd::Format("is messaging you, and you have user mode +g set. Use /ACCEPT +%s to allow.",
diff --git a/src/modules/m_cap.cpp b/src/modules/m_cap.cpp
index e368145b8..fd1cc2127 100644
--- a/src/modules/m_cap.cpp
+++ b/src/modules/m_cap.cpp
@@ -158,7 +158,7 @@ class Cap::ManagerImpl : public Cap::Manager, public ReloadModule::EventListener
 		managerimpl = this;
 	}
 
-	~ManagerImpl()
+	~ManagerImpl() override
 	{
 		for (CapMap::iterator i = caps.begin(); i != caps.end(); ++i)
 		{
diff --git a/src/modules/m_cban.cpp b/src/modules/m_cban.cpp
index 8ca02402b..70c01109d 100644
--- a/src/modules/m_cban.cpp
+++ b/src/modules/m_cban.cpp
@@ -180,7 +180,7 @@ class ModuleCBan : public Module, public Stats::EventListener
 		ServerInstance->XLines->RegisterFactory(&f);
 	}
 
-	~ModuleCBan()
+	~ModuleCBan() override
 	{
 		ServerInstance->XLines->DelAll("CBAN");
 		ServerInstance->XLines->UnregisterFactory(&f);
diff --git a/src/modules/m_cloaking.cpp b/src/modules/m_cloaking.cpp
index 2000f1c40..79fa98faa 100644
--- a/src/modules/m_cloaking.cpp
+++ b/src/modules/m_cloaking.cpp
@@ -494,8 +494,8 @@ class ModuleCloaking : public Module
 				break;
 			}
 			case MODE_OPAQUE:
-			default:
 				chost = SegmentIP(info, ip, true);
+				break;
 		}
 		return chost;
 	}
diff --git a/src/modules/m_codepage.cpp b/src/modules/m_codepage.cpp
index 69bd6c1ad..4884da5d6 100644
--- a/src/modules/m_codepage.cpp
+++ b/src/modules/m_codepage.cpp
@@ -124,7 +124,7 @@ class ModuleCodepage
 	{
 	}
 
-	~ModuleCodepage()
+	~ModuleCodepage() override
 	{
 		ServerInstance->IsNick = origisnick;
 		CheckInvalidNick();
diff --git a/src/modules/m_customprefix.cpp b/src/modules/m_customprefix.cpp
index 5cfb0fe3f..aa71fd3c1 100644
--- a/src/modules/m_customprefix.cpp
+++ b/src/modules/m_customprefix.cpp
@@ -103,7 +103,7 @@ class ModuleCustomPrefix : public Module
 		}
 	}
 
-	~ModuleCustomPrefix()
+	~ModuleCustomPrefix() override
 	{
 		stdalgo::delete_all(modes);
 	}
diff --git a/src/modules/m_dnsbl.cpp b/src/modules/m_dnsbl.cpp
index fc1465f7a..1857465af 100644
--- a/src/modules/m_dnsbl.cpp
+++ b/src/modules/m_dnsbl.cpp
@@ -234,7 +234,6 @@ class DNSBLResolver : public DNS::Request
 					break;
 				}
 				case DNSBLConfEntry::I_UNKNOWN:
-				default:
 					break;
 			}
 
diff --git a/src/modules/m_exemptchanops.cpp b/src/modules/m_exemptchanops.cpp
index 37146e03c..b44a825fb 100644
--- a/src/modules/m_exemptchanops.cpp
+++ b/src/modules/m_exemptchanops.cpp
@@ -40,12 +40,12 @@ class ExemptChanOps : public ListModeBase
 		syntax = "<restriction>:<prefix>";
 	}
 
-	static PrefixMode* FindMode(const std::string& mode)
+	static PrefixMode* FindMode(const std::string& pmode)
 	{
-		if (mode.length() == 1)
-			return ServerInstance->Modes.FindPrefixMode(mode[0]);
+		if (pmode.length() == 1)
+			return ServerInstance->Modes.FindPrefixMode(pmode[0]);
 
-		ModeHandler* mh = ServerInstance->Modes.FindMode(mode, MODETYPE_CHANNEL);
+		ModeHandler* mh = ServerInstance->Modes.FindMode(pmode, MODETYPE_CHANNEL);
 		return mh ? mh->IsPrefixMode() : NULL;
 	}
 
diff --git a/src/modules/m_filter.cpp b/src/modules/m_filter.cpp
index e2cfb13ed..cc9f2a211 100644
--- a/src/modules/m_filter.cpp
+++ b/src/modules/m_filter.cpp
@@ -128,7 +128,6 @@ class FilterResult
 				break;
 				default:
 					return *n;
-				break;
 			}
 		}
 		return 0;
diff --git a/src/modules/m_hidelist.cpp b/src/modules/m_hidelist.cpp
index 3f8e5bc12..afcafbcce 100644
--- a/src/modules/m_hidelist.cpp
+++ b/src/modules/m_hidelist.cpp
@@ -86,7 +86,7 @@ class ModuleHideList : public Module
 	{
 	}
 
-	~ModuleHideList()
+	~ModuleHideList() override
 	{
 		stdalgo::delete_all(watchers);
 	}
diff --git a/src/modules/m_httpd.cpp b/src/modules/m_httpd.cpp
index 9a2006035..168f0bdca 100644
--- a/src/modules/m_httpd.cpp
+++ b/src/modules/m_httpd.cpp
@@ -26,7 +26,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-/// $CompilerFlags: -Ivendor_directory("http_parser")
+/// $CompilerFlags: -isystem vendor_directory("http_parser")
 
 
 #include "inspircd.h"
@@ -225,7 +225,7 @@ class HttpServerSocket : public BufferedSocket, public Timer, public insp::intru
 		ServerInstance->Timers.AddTimer(this);
 	}
 
-	~HttpServerSocket()
+	~HttpServerSocket() override
 	{
 		sockets.erase(this);
 	}
diff --git a/src/modules/m_httpd_stats.cpp b/src/modules/m_httpd_stats.cpp
index c18c8c960..41e592f7f 100644
--- a/src/modules/m_httpd_stats.cpp
+++ b/src/modules/m_httpd_stats.cpp
@@ -320,17 +320,14 @@ namespace Stats
 
 		bool operator()(User* u1, User* u2)
 		{
-			switch (order) {
+			switch (order)
+			{
 				case OB_LASTMSG:
 					return Compare(IS_LOCAL(u1)->idle_lastmsg, IS_LOCAL(u2)->idle_lastmsg);
-					break;
 				case OB_NICK:
 					return Compare(u1->nick, u2->nick);
-					break;
-				default:
 				case OB_NONE:
 					return false;
-					break;
 			}
 		}
 	};
diff --git a/src/modules/m_ircv3_sts.cpp b/src/modules/m_ircv3_sts.cpp
index ef1586208..4ee85bf73 100644
--- a/src/modules/m_ircv3_sts.cpp
+++ b/src/modules/m_ircv3_sts.cpp
@@ -74,7 +74,7 @@ class STSCap : public Cap::Capability
 		DisableAutoRegister();
 	}
 
-	~STSCap()
+	~STSCap() override
 	{
 		// TODO: Send duration=0 when STS vanishes.
 	}
diff --git a/src/modules/m_nationalchars.cpp b/src/modules/m_nationalchars.cpp
index 539465b42..a57ae26fd 100644
--- a/src/modules/m_nationalchars.cpp
+++ b/src/modules/m_nationalchars.cpp
@@ -311,7 +311,7 @@ class ModuleNationalChars : public Module
 		}
 	}
 
-	~ModuleNationalChars()
+	~ModuleNationalChars() override
 	{
 		ServerInstance->IsNick = rememberer;
 		national_case_insensitive_map = lowermap_rememberer;
diff --git a/src/modules/m_pbkdf2.cpp b/src/modules/m_pbkdf2.cpp
index 6804ba89d..ddaa7a8e3 100644
--- a/src/modules/m_pbkdf2.cpp
+++ b/src/modules/m_pbkdf2.cpp
@@ -207,7 +207,7 @@ class ModulePBKDF2 : public Module
 	{
 	}
 
-	~ModulePBKDF2()
+	~ModulePBKDF2() override
 	{
 		stdalgo::delete_all(providers);
 	}
diff --git a/src/modules/m_rline.cpp b/src/modules/m_rline.cpp
index 80a597846..fe9bd7e48 100644
--- a/src/modules/m_rline.cpp
+++ b/src/modules/m_rline.cpp
@@ -232,7 +232,7 @@ class ModuleRLine
 		ServerInstance->XLines->RegisterFactory(&f);
 	}
 
-	~ModuleRLine()
+	~ModuleRLine() override
 	{
 		ServerInstance->XLines->DelAll("R");
 		ServerInstance->XLines->UnregisterFactory(&f);
diff --git a/src/modules/m_sasl.cpp b/src/modules/m_sasl.cpp
index 095a42fe7..b7318c86d 100644
--- a/src/modules/m_sasl.cpp
+++ b/src/modules/m_sasl.cpp
@@ -231,43 +231,41 @@ class SaslAuthenticator
 	{
 		switch (this->state)
 		{
-		 case SASL_INIT:
-			this->agent = msg[0];
-			this->state = SASL_COMM;
-			/* fall through */
-		 case SASL_COMM:
-			if (msg[0] != this->agent)
-				return this->state;
+			case SASL_INIT:
+				this->agent = msg[0];
+				this->state = SASL_COMM;
+				[[fallthrough]];
 
-			if (msg.size() < 4)
-				return this->state;
+			case SASL_COMM:
+				if (msg[0] != this->agent)
+					return this->state;
 
-			if (msg[2] == "C")
-			{
-				ClientProtocol::Message authmsg("AUTHENTICATE");
-				authmsg.PushParamRef(msg[3]);
+				if (msg.size() < 4)
+					return this->state;
 
-				ClientProtocol::Event authevent(*g_protoev, authmsg);
-				LocalUser* const localuser = IS_LOCAL(user);
-				if (localuser)
-					localuser->Send(authevent);
-			}
-			else if (msg[2] == "D")
-			{
-				this->state = SASL_DONE;
-				this->result = this->GetSaslResult(msg[3]);
-			}
-			else if (msg[2] == "M")
-				this->user->WriteNumeric(RPL_SASLMECHS, msg[3], "are available SASL mechanisms");
-			else
-				ServerInstance->Logs.Log(MODNAME, LOG_DEFAULT, "Services sent an unknown SASL message \"%s\" \"%s\"", msg[2].c_str(), msg[3].c_str());
+				if (msg[2] == "C")
+				{
+					ClientProtocol::Message authmsg("AUTHENTICATE");
+					authmsg.PushParamRef(msg[3]);
 
-			break;
-		 case SASL_DONE:
-			break;
-		 default:
-			ServerInstance->Logs.Log(MODNAME, LOG_DEFAULT, "WTF: SaslState is not a known state (%d)", this->state);
-			break;
+					ClientProtocol::Event authevent(*g_protoev, authmsg);
+					LocalUser* const localuser = IS_LOCAL(user);
+					if (localuser)
+						localuser->Send(authevent);
+				}
+				else if (msg[2] == "D")
+				{
+					this->state = SASL_DONE;
+					this->result = this->GetSaslResult(msg[3]);
+				}
+				else if (msg[2] == "M")
+					this->user->WriteNumeric(RPL_SASLMECHS, msg[3], "are available SASL mechanisms");
+				else
+					ServerInstance->Logs.Log(MODNAME, LOG_DEFAULT, "Services sent an unknown SASL message \"%s\" \"%s\"", msg[2].c_str(), msg[3].c_str());
+				break;
+
+			case SASL_DONE:
+				break;
 		}
 
 		return this->state;
@@ -306,8 +304,6 @@ class SaslAuthenticator
 		 case SASL_FAIL:
 			this->user->WriteNumeric(ERR_SASLFAIL, "SASL authentication failed");
 			break;
-		 default:
-			break;
 		}
 
 		this->state_announced = true;
diff --git a/src/modules/m_services_account.cpp b/src/modules/m_services_account.cpp
index db15f8c26..cdef9ec04 100644
--- a/src/modules/m_services_account.cpp
+++ b/src/modules/m_services_account.cpp
@@ -264,7 +264,6 @@ class ModuleServicesAccount
 				// User is messaging a +M channel and is not registered or exempt.
 				user->WriteNumeric(ERR_NEEDREGGEDNICK, targchan->name, "You need to be identified to a registered account to message this channel");
 				return MOD_RES_DENY;
-				break;
 			}
 			case MessageTarget::TYPE_USER:
 			{
@@ -278,7 +277,6 @@ class ModuleServicesAccount
 				// User is messaging a +R user and is not registered or on an accept list.
 				user->WriteNumeric(ERR_NEEDREGGEDNICK, targuser->nick, "You need to be identified to a registered account to message this user");
 				return MOD_RES_DENY;
-				break;
 			}
 			case MessageTarget::TYPE_SERVER:
 				break;
diff --git a/src/modules/m_sha2.cpp b/src/modules/m_sha2.cpp
index 3c3560d5c..e3ad8a6f7 100644
--- a/src/modules/m_sha2.cpp
+++ b/src/modules/m_sha2.cpp
@@ -23,7 +23,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-/// $CompilerFlags: -Ivendor_directory("sha2")
+/// $CompilerFlags: -isystem vendor_directory("sha2")
 
 
 #include "inspircd.h"
@@ -43,7 +43,7 @@ class HashSHA2 : public HashProvider
 	std::string GenerateRaw(const std::string& data) override
 	{
 		std::vector<char> bytes(out_size);
-		SHA((unsigned char*)data.data(), data.size(), (unsigned char*)&bytes[0]);
+		SHA(reinterpret_cast<const unsigned char*>(data.data()), data.size(), reinterpret_cast<unsigned char*>(&bytes[0]));
 		return std::string(&bytes[0], bytes.size());
 	}
 };
diff --git a/src/modules/m_showfile.cpp b/src/modules/m_showfile.cpp
index 3c9973853..d8e8ef827 100644
--- a/src/modules/m_showfile.cpp
+++ b/src/modules/m_showfile.cpp
@@ -171,7 +171,7 @@ class ModuleShowFile : public Module
 		cmds.swap(newcmds);
 	}
 
-	~ModuleShowFile()
+	~ModuleShowFile() override
 	{
 		stdalgo::delete_all(cmds);
 	}
diff --git a/src/modules/m_shun.cpp b/src/modules/m_shun.cpp
index 6ff15645d..404ddbb43 100644
--- a/src/modules/m_shun.cpp
+++ b/src/modules/m_shun.cpp
@@ -185,7 +185,7 @@ class ModuleShun : public Module, public Stats::EventListener
 		ServerInstance->XLines->RegisterFactory(&shun);
 	}
 
-	~ModuleShun()
+	~ModuleShun() override
 	{
 		ServerInstance->XLines->DelAll("SHUN");
 		ServerInstance->XLines->UnregisterFactory(&shun);
diff --git a/src/modules/m_spanningtree/commands.h b/src/modules/m_spanningtree/commands.h
index 234776d7c..152ee25d7 100644
--- a/src/modules/m_spanningtree/commands.h
+++ b/src/modules/m_spanningtree/commands.h
@@ -102,9 +102,9 @@ class CommandMetadata : public ServerCommand
 	class Builder : public CmdBuilder
 	{
 	 public:
-		Builder(User* user, const std::string& key, const std::string& val);
-		Builder(Channel* chan, const std::string& key, const std::string& val);
-		Builder(Membership* memb, const std::string& key, const std::string& val);
+		Builder(const User* user, const std::string& key, const std::string& val);
+		Builder(const Channel* chan, const std::string& key, const std::string& val);
+		Builder(const Membership* memb, const std::string& key, const std::string& val);
 		Builder(const std::string& key, const std::string& val);
 	};
 };
diff --git a/src/modules/m_spanningtree/main.h b/src/modules/m_spanningtree/main.h
index 0d4c32d72..7b1f8ef5b 100644
--- a/src/modules/m_spanningtree/main.h
+++ b/src/modules/m_spanningtree/main.h
@@ -220,6 +220,6 @@ class ModuleSpanningTree
 	void OnMode(User* source, User* u, Channel* c, const Modes::ChangeList& modes, ModeParser::ModeProcessFlag processflags) override;
 	void OnShutdown(const std::string& reason) override;
 	Cullable::Result Cull() override;
-	~ModuleSpanningTree();
+	~ModuleSpanningTree() override;
 	void Prioritize() override;
 };
diff --git a/src/modules/m_spanningtree/metadata.cpp b/src/modules/m_spanningtree/metadata.cpp
index f250861f1..aabd4cbbc 100644
--- a/src/modules/m_spanningtree/metadata.cpp
+++ b/src/modules/m_spanningtree/metadata.cpp
@@ -110,7 +110,7 @@ CmdResult CommandMetadata::Handle(User* srcuser, Params& params)
 	return CmdResult::SUCCESS;
 }
 
-CommandMetadata::Builder::Builder(User* user, const std::string& key, const std::string& val)
+CommandMetadata::Builder::Builder(const User* user, const std::string& key, const std::string& val)
 	: CmdBuilder("METADATA")
 {
 	push(user->uuid);
@@ -118,7 +118,7 @@ CommandMetadata::Builder::Builder(User* user, const std::string& key, const std:
 	push_last(val);
 }
 
-CommandMetadata::Builder::Builder(Channel* chan, const std::string& key, const std::string& val)
+CommandMetadata::Builder::Builder(const Channel* chan, const std::string& key, const std::string& val)
 	: CmdBuilder("METADATA")
 {
 	push(chan->name);
@@ -127,7 +127,7 @@ CommandMetadata::Builder::Builder(Channel* chan, const std::string& key, const s
 	push_last(val);
 }
 
-CommandMetadata::Builder::Builder(Membership* memb, const std::string& key, const std::string& val)
+CommandMetadata::Builder::Builder(const Membership* memb, const std::string& key, const std::string& val)
 	: CmdBuilder("METADATA")
 {
 	push_raw("@");
diff --git a/src/modules/m_spanningtree/protocolinterface.cpp b/src/modules/m_spanningtree/protocolinterface.cpp
index 59a282378..8e0d0fd4d 100644
--- a/src/modules/m_spanningtree/protocolinterface.cpp
+++ b/src/modules/m_spanningtree/protocolinterface.cpp
@@ -87,17 +87,17 @@ void SpanningTreeProtocolInterface::BroadcastEncap(const std::string& cmd, const
 	CmdBuilder(source, "ENCAP * ").push_raw(cmd).insert(params).Forward(server);
 }
 
-void SpanningTreeProtocolInterface::SendMetaData(User* u, const std::string& key, const std::string& data)
+void SpanningTreeProtocolInterface::SendMetaData(const User* u, const std::string& key, const std::string& data)
 {
 	CommandMetadata::Builder(u, key, data).Broadcast();
 }
 
-void SpanningTreeProtocolInterface::SendMetaData(Channel* c, const std::string& key, const std::string& data)
+void SpanningTreeProtocolInterface::SendMetaData(const Channel* c, const std::string& key, const std::string& data)
 {
 	CommandMetadata::Builder(c, key, data).Broadcast();
 }
 
-void SpanningTreeProtocolInterface::SendMetaData(Membership* m, const std::string& key, const std::string& data)
+void SpanningTreeProtocolInterface::SendMetaData(const Membership* m, const std::string& key, const std::string& data)
 {
 	CommandMetadata::Builder(m, key, data).Broadcast();
 }
diff --git a/src/modules/m_spanningtree/protocolinterface.h b/src/modules/m_spanningtree/protocolinterface.h
index b44599db0..e4cda3c84 100644
--- a/src/modules/m_spanningtree/protocolinterface.h
+++ b/src/modules/m_spanningtree/protocolinterface.h
@@ -37,9 +37,9 @@ class SpanningTreeProtocolInterface : public ProtocolInterface
 
 	bool SendEncapsulatedData(const std::string& targetmask, const std::string& cmd, const CommandBase::Params& params, User* source) override;
 	void BroadcastEncap(const std::string& cmd, const CommandBase::Params& params, User* source, User* omit) override;
-	void SendMetaData(User* user, const std::string& key, const std::string& data) override;
-	void SendMetaData(Channel* chan, const std::string& key, const std::string& data) override;
-	void SendMetaData(Membership* memb, const std::string& key, const std::string& data) override;
+	void SendMetaData(const User* user, const std::string& key, const std::string& data) override;
+	void SendMetaData(const Channel* chan, const std::string& key, const std::string& data) override;
+	void SendMetaData(const Membership* memb, const std::string& key, const std::string& data) override;
 	void SendMetaData(const std::string& key, const std::string& data) override;
 	void SendSNONotice(char snomask, const std::string& text) override;
 	void SendMessage(Channel* target, char status, const std::string& text, MessageType msgtype) override;
diff --git a/src/modules/m_spanningtree/treeserver.h b/src/modules/m_spanningtree/treeserver.h
index 028bbf49d..8b09f3817 100644
--- a/src/modules/m_spanningtree/treeserver.h
+++ b/src/modules/m_spanningtree/treeserver.h
@@ -234,7 +234,7 @@ class TreeServer : public Server
 
 	/** Destructor, deletes ServerUser unless IsRoot()
 	 */
-	~TreeServer();
+	~TreeServer() override;
 
 	/** Returns the TreeServer the given user is connected to
 	 * @param user The user whose server to return
diff --git a/src/modules/m_spanningtree/utils.h b/src/modules/m_spanningtree/utils.h
index 2782330d5..daca8417b 100644
--- a/src/modules/m_spanningtree/utils.h
+++ b/src/modules/m_spanningtree/utils.h
@@ -123,7 +123,7 @@ class SpanningTreeUtilities : public Cullable
 
 	/** Destroy class and free listeners etc
 	 */
-	~SpanningTreeUtilities();
+	~SpanningTreeUtilities() override;
 
 	void RouteCommand(TreeServer* origin, CommandBase* cmd, const CommandBase::Params& parameters, User* user);
 
diff --git a/src/modules/m_sqloper.cpp b/src/modules/m_sqloper.cpp
index f037336ff..7ff0b1759 100644
--- a/src/modules/m_sqloper.cpp
+++ b/src/modules/m_sqloper.cpp
@@ -195,7 +195,7 @@ public:
 		GetOperBlocks();
 	}
 
-	~ModuleSQLOper()
+	~ModuleSQLOper() override
 	{
 		// Remove all oper blocks that were from the DB
 		for (std::vector<std::string>::const_iterator i = my_blocks.begin(); i != my_blocks.end(); ++i)
diff --git a/src/modules/m_svshold.cpp b/src/modules/m_svshold.cpp
index 4b60e5110..e7b7027db 100644
--- a/src/modules/m_svshold.cpp
+++ b/src/modules/m_svshold.cpp
@@ -223,7 +223,7 @@ class ModuleSVSHold : public Module, public Stats::EventListener
 		return MOD_RES_PASSTHRU;
 	}
 
-	~ModuleSVSHold()
+	~ModuleSVSHold() override
 	{
 		ServerInstance->XLines->DelAll("SVSHOLD");
 		ServerInstance->XLines->UnregisterFactory(&s);
diff --git a/src/modules/m_websocket.cpp b/src/modules/m_websocket.cpp
index bd9ce068b..9bbf6ffa0 100644
--- a/src/modules/m_websocket.cpp
+++ b/src/modules/m_websocket.cpp
@@ -18,7 +18,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-/// $CompilerFlags: -Ivendor_directory("utfcpp")
+/// $CompilerFlags: -isystem vendor_directory("utfcpp")
 
 
 #include "inspircd.h"
diff --git a/src/snomasks.cpp b/src/snomasks.cpp
index cf1f2554a..296525534 100644
--- a/src/snomasks.cpp
+++ b/src/snomasks.cpp
@@ -147,6 +147,6 @@ std::string Snomask::GetDescription(char letter) const
 	if (!Description.empty())
 		ret += Description;
 	else
-		ret += std::string("SNO-") + (char)tolower(letter);
+		ret += InspIRCd::Format("SNO-%c", tolower(letter));
 	return ret;
 }
diff --git a/src/socket.cpp b/src/socket.cpp
index 4e408ec33..34da4d79e 100644
--- a/src/socket.cpp
+++ b/src/socket.cpp
@@ -236,13 +236,13 @@ std::string irc::sockets::sockaddrs::addr() const
 	{
 		case AF_INET:
 			char ip4addr[INET_ADDRSTRLEN];
-			if (!inet_ntop(AF_INET, (void*)&in4.sin_addr, ip4addr, sizeof(ip4addr)))
+			if (!inet_ntop(AF_INET, static_cast<const void*>(&in4.sin_addr), ip4addr, sizeof(ip4addr)))
 				return "0.0.0.0";
 			return ip4addr;
 
 		case AF_INET6:
 			char ip6addr[INET6_ADDRSTRLEN];
-			if (!inet_ntop(AF_INET6, (void*)&in6.sin6_addr, ip6addr, sizeof(ip6addr)))
+			if (!inet_ntop(AF_INET6, static_cast<const void*>(&in6.sin6_addr), ip6addr, sizeof(ip6addr)))
 				return "0:0:0:0:0:0:0:0";
 			return ip6addr;
 
@@ -261,13 +261,13 @@ std::string irc::sockets::sockaddrs::str() const
 	{
 		case AF_INET:
 			char ip4addr[INET_ADDRSTRLEN];
-			if (!inet_ntop(AF_INET, (void*)&in4.sin_addr, ip4addr, sizeof(ip4addr)))
+			if (!inet_ntop(AF_INET, static_cast<const void*>(&in4.sin_addr), ip4addr, sizeof(ip4addr)))
 				strcpy(ip4addr, "0.0.0.0");
 			return InspIRCd::Format("%s:%u", ip4addr, ntohs(in4.sin_port));
 
 		case AF_INET6:
 			char ip6addr[INET6_ADDRSTRLEN];
-			if (!inet_ntop(AF_INET6, (void*)&in6.sin6_addr, ip6addr, sizeof(ip6addr)))
+			if (!inet_ntop(AF_INET6, static_cast<const void*>(&in6.sin6_addr), ip6addr, sizeof(ip6addr)))
 				strcpy(ip6addr, "0:0:0:0:0:0:0:0");
 			return InspIRCd::Format("[%s]:%u", ip6addr, ntohs(in6.sin6_port));
 
@@ -340,13 +340,13 @@ static void sa2cidr(irc::sockets::cidr_mask& cidr, const irc::sockets::sockaddrs
 		case AF_INET:
 			cidr.length = range > 32 ? 32 : range;
 			target_byte = sizeof(sa.in4.sin_addr);
-			base = (unsigned char*)&sa.in4.sin_addr;
+			base = reinterpret_cast<const unsigned char*>(&sa.in4.sin_addr);
 			break;
 
 		case AF_INET6:
 			cidr.length = range > 128 ? 128 : range;
 			target_byte = sizeof(sa.in6.sin6_addr);
-			base = (unsigned char*)&sa.in6.sin6_addr;
+			base = reinterpret_cast<const unsigned char*>(&sa.in6.sin6_addr);
 			break;
 
 		default:
@@ -402,12 +402,12 @@ std::string irc::sockets::cidr_mask::str() const
 	switch (type)
 	{
 		case AF_INET:
-			base = (unsigned char*)&sa.in4.sin_addr;
+			base = reinterpret_cast<unsigned char*>(&sa.in4.sin_addr);
 			len = 4;
 			break;
 
 		case AF_INET6:
-			base = (unsigned char*)&sa.in6.sin6_addr;
+			base = reinterpret_cast<unsigned char*>(&sa.in6.sin6_addr);
 			len = 16;
 			break;
 
@@ -421,7 +421,7 @@ std::string irc::sockets::cidr_mask::str() const
 	}
 
 	memcpy(base, bits, len);
-	return sa.addr() + "/" + ConvToStr((int)length);
+	return sa.addr() + "/" + ConvToStr(length);
 }
 
 bool irc::sockets::cidr_mask::operator==(const cidr_mask& other) const
diff --git a/src/socketengine.cpp b/src/socketengine.cpp
index 9186f2c8c..2841e20a2 100644
--- a/src/socketengine.cpp
+++ b/src/socketengine.cpp
@@ -231,33 +231,33 @@ int SocketEngine::NonBlocking(int fd)
 void SocketEngine::SetReuse(int fd)
 {
 	int on = 1;
-	setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, (char*)&on, sizeof(on));
+	setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, static_cast<void*>(&on), sizeof(on));
 }
 
 int SocketEngine::RecvFrom(EventHandler* fd, void *buf, size_t len, int flags, sockaddr *from, socklen_t *fromlen)
 {
-	int nbRecvd = recvfrom(fd->GetFd(), (char*)buf, len, flags, from, fromlen);
+	int nbRecvd = recvfrom(fd->GetFd(), static_cast<char*>(buf), len, flags, from, fromlen);
 	stats.UpdateReadCounters(nbRecvd);
 	return nbRecvd;
 }
 
 int SocketEngine::Send(EventHandler* fd, const void *buf, size_t len, int flags)
 {
-	int nbSent = send(fd->GetFd(), (const char*)buf, len, flags);
+	int nbSent = send(fd->GetFd(), static_cast<const char*>(buf), len, flags);
 	stats.UpdateWriteCounters(nbSent);
 	return nbSent;
 }
 
 int SocketEngine::Recv(EventHandler* fd, void *buf, size_t len, int flags)
 {
-	int nbRecvd = recv(fd->GetFd(), (char*)buf, len, flags);
+	int nbRecvd = recv(fd->GetFd(), static_cast<char*>(buf), len, flags);
 	stats.UpdateReadCounters(nbRecvd);
 	return nbRecvd;
 }
 
 int SocketEngine::SendTo(EventHandler* fd, const void* buf, size_t len, int flags, const irc::sockets::sockaddrs& address)
 {
-	int nbSent = sendto(fd->GetFd(), (const char*)buf, len, flags, &address.sa, address.sa_size());
+	int nbSent = sendto(fd->GetFd(), static_cast<const char*>(buf), len, flags, &address.sa, address.sa_size());
 	stats.UpdateWriteCounters(nbSent);
 	return nbSent;
 }
@@ -354,8 +354,8 @@ void SocketEngine::Statistics::CheckFlush() const
 void SocketEngine::Statistics::GetBandwidth(float& kbitpersec_in, float& kbitpersec_out, float& kbitpersec_total) const
 {
 	CheckFlush();
-	float in_kbit = indata * 8;
-	float out_kbit = outdata * 8;
+	float in_kbit = static_cast<float>(indata) * 8;
+	float out_kbit = static_cast<float>(outdata) * 8;
 	kbitpersec_total = ((in_kbit + out_kbit) / 1024);
 	kbitpersec_in = in_kbit / 1024;
 	kbitpersec_out = out_kbit / 1024;
diff --git a/src/threadsocket.cpp b/src/threadsocket.cpp
index a2d0aae82..4a8b542eb 100644
--- a/src/threadsocket.cpp
+++ b/src/threadsocket.cpp
@@ -35,7 +35,7 @@ class ThreadSignalSocket : public EventHandler
 		SocketEngine::AddFd(this, FD_WANT_FAST_READ | FD_WANT_NO_WRITE);
 	}
 
-	~ThreadSignalSocket()
+	~ThreadSignalSocket() override
 	{
 		SocketEngine::Close(this);
 	}
diff --git a/src/users.cpp b/src/users.cpp
index fd68c6761..4415a2f01 100644
--- a/src/users.cpp
+++ b/src/users.cpp
@@ -234,8 +234,8 @@ void UserIOHandler::OnDataReady()
 	if (recvq.length() > user->GetClass()->GetRecvqMax() && !user->HasPrivPermission("users/flood/increased-buffers"))
 	{
 		ServerInstance->Users.QuitUser(user, "RecvQ exceeded");
-		ServerInstance->SNO.WriteToSnoMask('a', "User %s RecvQ of %lu exceeds connect class maximum of %lu",
-			user->nick.c_str(), (unsigned long)recvq.length(), user->GetClass()->GetRecvqMax());
+		ServerInstance->SNO.WriteToSnoMask('a', "User %s RecvQ of %zu exceeds connect class maximum of %lu",
+			user->nick.c_str(), recvq.length(), user->GetClass()->GetRecvqMax());
 		return;
 	}
 
@@ -796,7 +796,7 @@ void LocalUser::Write(const ClientProtocol::SerializedMessage& text)
 		if (nlpos == std::string::npos)
 			nlpos = text.length(); // TODO is this ok, test it
 
-		ServerInstance->Logs.Log("USEROUTPUT", LOG_RAWIO, "C[%s] O %.*s", uuid.c_str(), (int) nlpos, text.c_str());
+		ServerInstance->Logs.Log("USEROUTPUT", LOG_RAWIO, "C[%s] O %.*s", uuid.c_str(), static_cast<int>(nlpos), text.c_str());
 	}
 
 	eh.AddWriteBuf(text);
diff --git a/src/wildcard.cpp b/src/wildcard.cpp
index f9e706906..364051cf1 100644
--- a/src/wildcard.cpp
+++ b/src/wildcard.cpp
@@ -26,10 +26,10 @@
 
 static bool MatchInternal(const unsigned char* str, const unsigned char* mask, unsigned const char* map)
 {
-	unsigned char* cp = NULL;
-	unsigned char* mp = NULL;
-	unsigned char* string = (unsigned char*)str;
-	unsigned char* wild = (unsigned char*)mask;
+	const unsigned char* cp = nullptr;
+	const unsigned char* mp = nullptr;
+	const unsigned char* string = reinterpret_cast<const unsigned char*>(str);
+	const unsigned char* wild = reinterpret_cast<const unsigned char*>(mask);
 
 	while ((*string) && (*wild != '*'))
 	{
@@ -81,7 +81,7 @@ bool InspIRCd::Match(const std::string& str, const std::string& mask, unsigned c
 	if (!map)
 		map = national_case_insensitive_map;
 
-	return MatchInternal((const unsigned char*)str.c_str(), (const unsigned char*)mask.c_str(), map);
+	return MatchInternal(reinterpret_cast<const unsigned char*>(str.c_str()), reinterpret_cast<const unsigned char*>(mask.c_str()), map);
 }
 
 bool InspIRCd::Match(const char* str, const char* mask, unsigned const char* map)
@@ -89,7 +89,7 @@ bool InspIRCd::Match(const char* str, const char* mask, unsigned const char* map
 	if (!map)
 		map = national_case_insensitive_map;
 
-	return MatchInternal((const unsigned char*)str, (const unsigned char*)mask, map);
+	return MatchInternal(reinterpret_cast<const unsigned char*>(str), reinterpret_cast<const unsigned char*>(mask), map);
 }
 
 bool InspIRCd::MatchCIDR(const std::string& str, const std::string& mask, unsigned const char* map)