Remove prototypes with empty declarations (#12020)

Technically declaring a prototype with an empty declaration has been deprecated since the early days of C, but we never got a warning for it. C2x will apparently be introducing a breaking change if you are using this type of declarator, so Clang 15 has started issuing a warning with -pedantic. Although not apparently a problem for any of the compiler we build on, if feels like the right thing is to properly adhere to the C standard and use (void).

43 files changed, 210 insertions, 211 deletions

diff --git a/src/Makefile b/src/Makefile
index d8efcafb2..4708d1a0a 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -40,7 +40,7 @@ ifneq (,$(findstring FreeBSD,$(uname_S)))
   STD+=-Wno-c11-extensions
 endif
 endif
-WARN=-Wall -W -Wno-missing-field-initializers -Werror=deprecated-declarations
+WARN=-Wall -W -Wno-missing-field-initializers -Werror=deprecated-declarations -Wstrict-prototypes
 OPT=$(OPTIMIZATION)
 
 # Detect if the compiler supports C11 _Atomic.
diff --git a/src/acl.c b/src/acl.c
index 25a9a0a47..ebf152aaa 100644
--- a/src/acl.c
+++ b/src/acl.c
@@ -642,7 +642,7 @@ void ACLSetSelectorCommandBitsForCategory(dict *commands, aclSelector *selector,
 /* This function is responsible for recomputing the command bits for all selectors of the existing users.
  * It uses the 'command_rules', a string representation of the ordered categories and commands, 
  * to recompute the command bits. */
-void ACLRecomputeCommandBitsFromCommandRulesAllUsers() {
+void ACLRecomputeCommandBitsFromCommandRulesAllUsers(void) {
     raxIterator ri;
     raxStart(&ri,Users);
     raxSeek(&ri,"^",NULL,0);
diff --git a/src/aof.c b/src/aof.c
index 55bca6e7a..468d577f8 100644
--- a/src/aof.c
+++ b/src/aof.c
@@ -164,12 +164,12 @@ void aofManifestFree(aofManifest *am) {
     zfree(am);
 }
 
-sds getAofManifestFileName() {
+sds getAofManifestFileName(void) {
     return sdscatprintf(sdsempty(), "%s%s", server.aof_filename,
                 MANIFEST_NAME_SUFFIX);
 }
 
-sds getTempAofManifestFileName() {
+sds getTempAofManifestFileName(void) {
     return sdscatprintf(sdsempty(), "%s%s%s", TEMP_FILE_NAME_PREFIX,
                 server.aof_filename, MANIFEST_NAME_SUFFIX);
 }
@@ -464,7 +464,7 @@ sds getNewIncrAofName(aofManifest *am) {
 }
 
 /* Get temp INCR type AOF name. */
-sds getTempIncrAofName() {
+sds getTempIncrAofName(void) {
     return sdscatprintf(sdsempty(), "%s%s%s", TEMP_FILE_NAME_PREFIX, server.aof_filename,
         INCR_FILE_SUFFIX);
 }
@@ -692,7 +692,7 @@ int aofDelHistoryFiles(void) {
 }
 
 /* Used to clean up temp INCR AOF when AOFRW fails. */
-void aofDelTempIncrAofFile() {
+void aofDelTempIncrAofFile(void) {
     sds aof_filename = getTempIncrAofName();
     sds aof_filepath = makePath(server.aof_dirname, aof_filename);
     serverLog(LL_NOTICE, "Removing the temp incr aof file %s in the background", aof_filename);
diff --git a/src/cli_common.c b/src/cli_common.c
index 7b4775cde..0b13db5dc 100644
--- a/src/cli_common.c
+++ b/src/cli_common.c
@@ -191,7 +191,7 @@ ssize_t cliWriteConn(redisContext *c, const char *buf, size_t buf_len)
 
 /* Wrapper around OpenSSL (libssl and libcrypto) initialisation
  */
-int cliSecureInit()
+int cliSecureInit(void)
 {
 #ifdef USE_OPENSSL
     ERR_load_crypto_strings();
diff --git a/src/cli_common.h b/src/cli_common.h
index c5c4c11aa..cffdee61d 100644
--- a/src/cli_common.h
+++ b/src/cli_common.h
@@ -37,7 +37,7 @@ int cliSecureConnection(redisContext *c, cliSSLconfig config, const char **err);
 
 ssize_t cliWriteConn(redisContext *c, const char *buf, size_t buf_len);
 
-int cliSecureInit();
+int cliSecureInit(void);
 
 sds readArgFromStdin(void);
 
diff --git a/src/cluster.c b/src/cluster.c
index b20225c8b..69029164e 100644
--- a/src/cluster.c
+++ b/src/cluster.c
@@ -126,7 +126,7 @@ dictType clusterNodesBlackListDictType = {
         NULL                        /* allow to expand */
 };
 
-static ConnectionType *connTypeOfCluster() {
+static ConnectionType *connTypeOfCluster(void) {
     if (server.tls_cluster) {
         return connectionTypeTls();
     }
@@ -2321,18 +2321,18 @@ uint32_t getAlignedPingExtSize(uint32_t dataSize) {
     return sizeof(clusterMsgPingExt) + EIGHT_BYTE_ALIGN(dataSize);
 }
 
-uint32_t getHostnamePingExtSize() {
+uint32_t getHostnamePingExtSize(void) {
     if (sdslen(myself->hostname) == 0) {
         return 0;
     }
     return getAlignedPingExtSize(sdslen(myself->hostname) + 1);
 }
 
-uint32_t getShardIdPingExtSize() {
+uint32_t getShardIdPingExtSize(void) {
     return getAlignedPingExtSize(sizeof(clusterMsgPingExtShardId));
 }
 
-uint32_t getForgottenNodeExtSize() {
+uint32_t getForgottenNodeExtSize(void) {
     return getAlignedPingExtSize(sizeof(clusterMsgPingExtForgottenNode));
 }
 
@@ -5559,7 +5559,7 @@ void clusterReplyMultiBulkSlots(client * c) {
     setDeferredArrayLen(c, slot_replylen, num_masters);
 }
 
-sds genClusterInfoString() {
+sds genClusterInfoString(void) {
     sds info = sdsempty();
     char *statestr[] = {"ok","fail"};
     int slots_assigned = 0, slots_ok = 0, slots_pfail = 0, slots_fail = 0;
diff --git a/src/cluster.h b/src/cluster.h
index cabc9273f..b5ab7d5a5 100644
--- a/src/cluster.h
+++ b/src/cluster.h
@@ -423,7 +423,7 @@ void slotToChannelDel(sds channel);
 void clusterUpdateMyselfHostname(void);
 void clusterUpdateMyselfAnnouncedPorts(void);
 sds clusterGenNodesDescription(int filter, int use_pport);
-sds genClusterInfoString();
+sds genClusterInfoString(void);
 void freeClusterLink(clusterLink *link);
 
 #endif /* __CLUSTER_H */
diff --git a/src/config.c b/src/config.c
index 9a3f8d969..6978cc5e7 100644
--- a/src/config.c
+++ b/src/config.c
@@ -1065,7 +1065,7 @@ void rewriteConfigReleaseState(struct rewriteConfigState *state) {
 }
 
 /* Create the configuration rewrite state */
-struct rewriteConfigState *rewriteConfigCreateState() {
+struct rewriteConfigState *rewriteConfigCreateState(void) {
     struct rewriteConfigState *state = zmalloc(sizeof(*state));
     state->option_to_line = dictCreate(&optionToLineDictType);
     state->rewritten = dictCreate(&optionSetDictType);
@@ -1643,7 +1643,7 @@ void rewriteConfigRemoveOrphaned(struct rewriteConfigState *state) {
 
 /* This function returns a string representation of all the config options
  * marked with DEBUG_CONFIG, which can be used to help with debugging. */
-sds getConfigDebugInfo() {
+sds getConfigDebugInfo(void) {
     struct rewriteConfigState *state = rewriteConfigCreateState();
     state->force_write = 1; /* Force the output */
     state->needs_signature = 0; /* Omit the rewrite signature */
@@ -3260,7 +3260,7 @@ int registerConfigValue(const char *name, const standardConfig *config, int alia
 
 /* Initialize configs to their default values and create and populate the 
  * runtime configuration dictionary. */
-void initConfigValues() {
+void initConfigValues(void) {
     configs = dictCreate(&sdsHashDictType);
     dictExpand(configs, sizeof(static_configs) / sizeof(standardConfig));
     for (standardConfig *config = static_configs; config->name != NULL; config++) {
diff --git a/src/connection.c b/src/connection.c
index 6bb0c9ec1..fd9d5d17a 100644
--- a/src/connection.c
+++ b/src/connection.c
@@ -57,7 +57,7 @@ int connTypeRegister(ConnectionType *ct) {
     return C_OK;
 }
 
-int connTypeInitialize() {
+int connTypeInitialize(void) {
     /* currently socket connection type is necessary  */
     serverAssert(RedisRegisterConnectionTypeSocket() == C_OK);
 
@@ -88,7 +88,7 @@ ConnectionType *connectionByType(const char *typename) {
 }
 
 /* Cache TCP connection type, query it by string once */
-ConnectionType *connectionTypeTcp() {
+ConnectionType *connectionTypeTcp(void) {
     static ConnectionType *ct_tcp = NULL;
 
     if (ct_tcp != NULL)
@@ -101,7 +101,7 @@ ConnectionType *connectionTypeTcp() {
 }
 
 /* Cache TLS connection type, query it by string once */
-ConnectionType *connectionTypeTls() {
+ConnectionType *connectionTypeTls(void) {
     static ConnectionType *ct_tls = NULL;
     static int cached = 0;
 
@@ -116,7 +116,7 @@ ConnectionType *connectionTypeTls() {
 }
 
 /* Cache Unix connection type, query it by string once */
-ConnectionType *connectionTypeUnix() {
+ConnectionType *connectionTypeUnix(void) {
     static ConnectionType *ct_unix = NULL;
 
     if (ct_unix != NULL)
@@ -141,7 +141,7 @@ int connectionIndexByType(const char *typename) {
     return -1;
 }
 
-void connTypeCleanupAll() {
+void connTypeCleanupAll(void) {
     ConnectionType *ct;
     int type;
 
diff --git a/src/connection.h b/src/connection.h
index da8b1b7c7..7c26ac635 100644
--- a/src/connection.h
+++ b/src/connection.h
@@ -379,7 +379,7 @@ static inline sds connGetPeerCert(connection *conn) {
 }
 
 /* Initialize the redis connection framework */
-int connTypeInitialize();
+int connTypeInitialize(void);
 
 /* Register a connection type into redis connection framework */
 int connTypeRegister(ConnectionType *ct);
@@ -388,13 +388,13 @@ int connTypeRegister(ConnectionType *ct);
 ConnectionType *connectionByType(const char *typename);
 
 /* Fast path to get TCP connection type */
-ConnectionType *connectionTypeTcp();
+ConnectionType *connectionTypeTcp(void);
 
 /* Fast path to get TLS connection type */
-ConnectionType *connectionTypeTls();
+ConnectionType *connectionTypeTls(void);
 
 /* Fast path to get Unix connection type */
-ConnectionType *connectionTypeUnix();
+ConnectionType *connectionTypeUnix(void);
 
 /* Lookup the index of a connection type by type name, return -1 if not found */
 int connectionIndexByType(const char *typename);
@@ -418,7 +418,7 @@ static inline int connTypeConfigure(ConnectionType *ct, void *priv, int reconfig
 }
 
 /* Walk all the connection types and cleanup them all if possible */
-void connTypeCleanupAll();
+void connTypeCleanupAll(void);
 
 /* Test all the connection type has pending data or not. */
 int connTypeHasPendingData(void);
@@ -441,8 +441,8 @@ static inline aeFileProc *connAcceptHandler(ConnectionType *ct) {
 /* Get Listeners information, note that caller should free the non-empty string */
 sds getListensInfoString(sds info);
 
-int RedisRegisterConnectionTypeSocket();
-int RedisRegisterConnectionTypeUnix();
-int RedisRegisterConnectionTypeTLS();
+int RedisRegisterConnectionTypeSocket(void);
+int RedisRegisterConnectionTypeUnix(void);
+int RedisRegisterConnectionTypeTLS(void);
 
 #endif  /* __REDIS_CONNECTION_H */
diff --git a/src/db.c b/src/db.c
index 31c8f69bd..de7c601b0 100644
--- a/src/db.c
+++ b/src/db.c
@@ -562,7 +562,7 @@ int selectDb(client *c, int id) {
     return C_OK;
 }
 
-long long dbTotalServerKeyCount() {
+long long dbTotalServerKeyCount(void) {
     long long total = 0;
     int j;
     for (j = 0; j < server.dbnum; j++) {
diff --git a/src/debug.c b/src/debug.c
index 68dcdcc9a..0305e8a73 100644
--- a/src/debug.c
+++ b/src/debug.c
@@ -2056,9 +2056,9 @@ void dumpCodeAroundEIP(void *eip) {
     }
 }
 
-void invalidFunctionWasCalled() {}
+void invalidFunctionWasCalled(void) {}
 
-typedef void (*invalidFunctionWasCalledType)();
+typedef void (*invalidFunctionWasCalledType)(void);
 
 void sigsegvHandler(int sig, siginfo_t *info, void *secret) {
     UNUSED(secret);
@@ -2227,7 +2227,7 @@ void watchdogScheduleSignal(int period) {
     it.it_interval.tv_usec = 0;
     setitimer(ITIMER_REAL, &it, NULL);
 }
-void applyWatchdogPeriod() {
+void applyWatchdogPeriod(void) {
     struct sigaction act;
 
     /* Disable watchdog when period is 0 */
diff --git a/src/defrag.c b/src/defrag.c
index 5b7fdb775..ff63cf8fd 100644
--- a/src/defrag.c
+++ b/src/defrag.c
@@ -781,7 +781,7 @@ float getAllocatorFragmentation(size_t *out_frag_bytes) {
 
 /* We may need to defrag other globals, one small allocation can hold a full allocator run.
  * so although small, it is still important to defrag these */
-void defragOtherGlobals() {
+void defragOtherGlobals(void) {
 
     /* there are many more pointers to defrag (e.g. client argv, output / aof buffers, etc.
      * but we assume most of these are short lived, we only need to defrag allocations
@@ -887,7 +887,7 @@ int defragLaterStep(redisDb *db, long long endtime) {
 #define LIMIT(y, min, max) ((y)<(min)? min: ((y)>(max)? max: (y)))
 
 /* decide if defrag is needed, and at what CPU effort to invest in it */
-void computeDefragCycles() {
+void computeDefragCycles(void) {
     size_t frag_bytes;
     float frag_pct = getAllocatorFragmentation(&frag_bytes);
     /* If we're not already running, and below the threshold, exit. */
diff --git a/src/eval.c b/src/eval.c
index 8ae3061ca..eb4b52936 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -650,15 +650,15 @@ NULL
     }
 }
 
-unsigned long evalMemory() {
+unsigned long evalMemory(void) {
     return luaMemory(lctx.lua);
 }
 
-dict* evalScriptsDict() {
+dict* evalScriptsDict(void) {
     return lctx.lua_scripts;
 }
 
-unsigned long evalScriptsMemory() {
+unsigned long evalScriptsMemory(void) {
     return lctx.lua_scripts_mem +
             dictMemUsage(lctx.lua_scripts) +
             dictSize(lctx.lua_scripts) * sizeof(luaScript);
@@ -688,7 +688,7 @@ void ldbFlushLog(list *log) {
         listDelNode(log,ln);
 }
 
-int ldbIsEnabled(){
+int ldbIsEnabled(void){
     return ldb.active && ldb.step;
 }
 
diff --git a/src/evict.c b/src/evict.c
index 41712b926..4ca9f62ed 100644
--- a/src/evict.c
+++ b/src/evict.c
@@ -494,7 +494,7 @@ static int isSafeToPerformEvictions(void) {
 }
 
 /* Algorithm for converting tenacity (0-100) to a time limit.  */
-static unsigned long evictionTimeLimitUs() {
+static unsigned long evictionTimeLimitUs(void) {
     serverAssert(server.maxmemory_eviction_tenacity >= 0);
     serverAssert(server.maxmemory_eviction_tenacity <= 100);
 
diff --git a/src/function_lua.c b/src/function_lua.c
index ca89818d8..91bb5cd67 100644
--- a/src/function_lua.c
+++ b/src/function_lua.c
@@ -420,7 +420,7 @@ static int luaRegisterFunction(lua_State *lua) {
 }
 
 /* Initialize Lua engine, should be called once on start. */
-int luaEngineInitEngine() {
+int luaEngineInitEngine(void) {
     luaEngineCtx *lua_engine_ctx = zmalloc(sizeof(*lua_engine_ctx));
     lua_engine_ctx->lua = lua_open();
 
diff --git a/src/functions.c b/src/functions.c
index c60d40d3c..f5738ba79 100644
--- a/src/functions.c
+++ b/src/functions.c
@@ -212,12 +212,12 @@ void functionsLibCtxSwapWithCurrent(functionsLibCtx *new_lib_ctx) {
 }
 
 /* return the current functions ctx */
-functionsLibCtx* functionsLibCtxGetCurrent() {
+functionsLibCtx* functionsLibCtxGetCurrent(void) {
     return curr_functions_lib_ctx;
 }
 
 /* Create a new functions ctx */
-functionsLibCtx* functionsLibCtxCreate() {
+functionsLibCtx* functionsLibCtxCreate(void) {
     functionsLibCtx *ret = zmalloc(sizeof(functionsLibCtx));
     ret->libraries = dictCreate(&librariesDictType);
     ret->functions = dictCreate(&functionDictType);
@@ -1075,7 +1075,7 @@ void functionLoadCommand(client *c) {
 }
 
 /* Return memory usage of all the engines combine */
-unsigned long functionsMemory() {
+unsigned long functionsMemory(void) {
     dictIterator *iter = dictGetIterator(engines);
     dictEntry *entry = NULL;
     size_t engines_nemory = 0;
@@ -1090,7 +1090,7 @@ unsigned long functionsMemory() {
 }
 
 /* Return memory overhead of all the engines combine */
-unsigned long functionsMemoryOverhead() {
+unsigned long functionsMemoryOverhead(void) {
     size_t memory_overhead = dictMemUsage(engines);
     memory_overhead += dictMemUsage(curr_functions_lib_ctx->functions);
     memory_overhead += sizeof(functionsLibCtx);
@@ -1101,15 +1101,15 @@ unsigned long functionsMemoryOverhead() {
 }
 
 /* Returns the number of functions */
-unsigned long functionsNum() {
+unsigned long functionsNum(void) {
     return dictSize(curr_functions_lib_ctx->functions);
 }
 
-unsigned long functionsLibNum() {
+unsigned long functionsLibNum(void) {
     return dictSize(curr_functions_lib_ctx->libraries);
 }
 
-dict* functionsLibGet() {
+dict* functionsLibGet(void) {
     return curr_functions_lib_ctx->libraries;
 }
 
@@ -1119,7 +1119,7 @@ size_t functionsLibCtxfunctionsLen(functionsLibCtx *functions_ctx) {
 
 /* Initialize engine data structures.
  * Should be called once on server initialization */
-int functionsInit() {
+int functionsInit(void) {
     engines = dictCreate(&engineDictType);
 
     if (luaEngineInitEngine() != C_OK) {
diff --git a/src/functions.h b/src/functions.h
index 40716dbc7..26e45babc 100644
--- a/src/functions.h
+++ b/src/functions.h
@@ -110,14 +110,14 @@ struct functionLibInfo {
 
 int functionsRegisterEngine(const char *engine_name, engine *engine_ctx);
 sds functionsCreateWithLibraryCtx(sds code, int replace, sds* err, functionsLibCtx *lib_ctx);
-unsigned long functionsMemory();
-unsigned long functionsMemoryOverhead();
-unsigned long functionsNum();
-unsigned long functionsLibNum();
-dict* functionsLibGet();
+unsigned long functionsMemory(void);
+unsigned long functionsMemoryOverhead(void);
+unsigned long functionsNum(void);
+unsigned long functionsLibNum(void);
+dict* functionsLibGet(void);
 size_t functionsLibCtxfunctionsLen(functionsLibCtx *functions_ctx);
-functionsLibCtx* functionsLibCtxGetCurrent();
-functionsLibCtx* functionsLibCtxCreate();
+functionsLibCtx* functionsLibCtxGetCurrent(void);
+functionsLibCtx* functionsLibCtxCreate(void);
 void functionsLibCtxClearCurrent(int async);
 void functionsLibCtxFree(functionsLibCtx *lib_ctx);
 void functionsLibCtxClear(functionsLibCtx *lib_ctx);
@@ -125,7 +125,7 @@ void functionsLibCtxSwapWithCurrent(functionsLibCtx *lib_ctx);
 
 int functionLibCreateFunction(sds name, void *function, functionLibInfo *li, sds desc, uint64_t f_flags, sds *err);
 
-int luaEngineInitEngine();
-int functionsInit();
+int luaEngineInitEngine(void);
+int functionsInit(void);
 
 #endif /* __FUNCTIONS_H_ */
diff --git a/src/lazyfree.c b/src/lazyfree.c
index a44ad2df4..8ac55f777 100644
--- a/src/lazyfree.c
+++ b/src/lazyfree.c
@@ -82,7 +82,7 @@ size_t lazyfreeGetFreedObjectsCount(void) {
     return aux;
 }
 
-void lazyfreeResetStats() {
+void lazyfreeResetStats(void) {
     atomicSet(lazyfreed_objects,0);
 }
 
diff --git a/src/listpack.c b/src/listpack.c
index f7c867f2e..ecc7e9f6f 100644
--- a/src/listpack.c
+++ b/src/listpack.c
@@ -1693,7 +1693,7 @@ char *mixlist[] = {"hello", "foo", "quux", "1024"};
 char *intlist[] = {"4294967296", "-100", "100", "128000", 
                    "non integer", "much much longer non integer"};
 
-static unsigned char *createList() {
+static unsigned char *createList(void) {
     unsigned char *lp = lpNew(0);
     lp = lpAppend(lp, (unsigned char*)mixlist[1], strlen(mixlist[1]));
     lp = lpAppend(lp, (unsigned char*)mixlist[2], strlen(mixlist[2]));
@@ -1702,7 +1702,7 @@ static unsigned char *createList() {
     return lp;
 }
 
-static unsigned char *createIntList() {
+static unsigned char *createIntList(void) {
     unsigned char *lp = lpNew(0);
     lp = lpAppend(lp, (unsigned char*)intlist[2], strlen(intlist[2]));
     lp = lpAppend(lp, (unsigned char*)intlist[3], strlen(intlist[3]));
diff --git a/src/module.c b/src/module.c
index 77256feae..561677e7e 100644
--- a/src/module.c
+++ b/src/module.c
@@ -789,7 +789,7 @@ int RM_GetApi(const char *funcname, void **targetPtrPtr) {
     return REDISMODULE_OK;
 }
 
-void modulePostExecutionUnitOperations() {
+void modulePostExecutionUnitOperations(void) {
     if (server.execution_nesting)
         return;
 
@@ -2276,7 +2276,7 @@ uint64_t RM_MonotonicMicroseconds(void) {
 }
 
 /* Return the current UNIX time in microseconds */
-ustime_t RM_Microseconds() {
+ustime_t RM_Microseconds(void) {
     return ustime();
 }
 
@@ -2286,7 +2286,7 @@ ustime_t RM_Microseconds() {
  * key space notification, causing a module to execute a RedisModule_Call,
  * causing another notification, etc.
  * It makes sense that all this callbacks would use the same clock. */
-ustime_t RM_CachedMicroseconds() {
+ustime_t RM_CachedMicroseconds(void) {
     return server.ustime;
 }
 
@@ -3913,7 +3913,7 @@ int RM_GetContextFlags(RedisModuleCtx *ctx) {
  * garbage collection tasks, or that do writes and replicate such writes
  * periodically in timer callbacks or other periodic callbacks.
  */
-int RM_AvoidReplicaTraffic() {
+int RM_AvoidReplicaTraffic(void) {
     return !!(isPausedActionsWithUpdate(PAUSE_ACTION_REPLICA));
 }
 
@@ -4023,7 +4023,7 @@ RedisModuleKey *RM_OpenKey(RedisModuleCtx *ctx, robj *keyname, int mode) {
  *              // REDISMODULE_OPEN_KEY_NOTOUCH is not supported
  *        }
  */
-int RM_GetOpenKeyModesAll() {
+int RM_GetOpenKeyModesAll(void) {
     return _REDISMODULE_OPEN_KEY_ALL;
 }
 
@@ -6950,7 +6950,7 @@ void moduleRDBLoadError(RedisModuleIO *io) {
 /* Returns 0 if there's at least one registered data type that did not declare
  * REDISMODULE_OPTIONS_HANDLE_IO_ERRORS, in which case diskless loading should
  * be avoided since it could cause data loss. */
-int moduleAllDatatypesHandleErrors() {
+int moduleAllDatatypesHandleErrors(void) {
     dictIterator *di = dictGetIterator(modules);
     dictEntry *de;
 
@@ -6970,7 +6970,7 @@ int moduleAllDatatypesHandleErrors() {
 /* Returns 0 if module did not declare REDISMODULE_OPTIONS_HANDLE_REPL_ASYNC_LOAD, in which case
  * diskless async loading should be avoided because module doesn't know there can be traffic during
  * database full resynchronization. */
-int moduleAllModulesHandleReplAsyncLoad() {
+int moduleAllModulesHandleReplAsyncLoad(void) {
     dictIterator *di = dictGetIterator(modules);
     dictEntry *de;
 
@@ -8418,7 +8418,7 @@ void RM_FreeThreadSafeContext(RedisModuleCtx *ctx) {
     zfree(ctx);
 }
 
-void moduleGILAfterLock() {
+void moduleGILAfterLock(void) {
     /* We should never get here if we already inside a module
      * code block which already opened a context. */
     serverAssert(server.execution_nesting == 0);
@@ -8454,7 +8454,7 @@ int RM_ThreadSafeContextTryLock(RedisModuleCtx *ctx) {
     return REDISMODULE_OK;
 }
 
-void moduleGILBeforeUnlock() {
+void moduleGILBeforeUnlock(void) {
     /* We should never get here if we already inside a module
      * code block which already opened a context, except
      * the bump-up from moduleGILAcquired. */
@@ -8569,7 +8569,7 @@ int RM_SubscribeToKeyspaceEvents(RedisModuleCtx *ctx, int types, RedisModuleNoti
     return REDISMODULE_OK;
 }
 
-void firePostExecutionUnitJobs() {
+void firePostExecutionUnitJobs(void) {
     /* Avoid propagation of commands.
      * In that way, postExecutionUnitOperations will prevent
      * recursive calls to firePostExecutionUnitJobs.
@@ -8622,7 +8622,7 @@ int RM_AddPostNotificationJob(RedisModuleCtx *ctx, RedisModulePostNotificationJo
 
 /* Get the configured bitmap of notify-keyspace-events (Could be used
  * for additional filtering in RedisModuleNotificationFunc) */
-int RM_GetNotifyKeyspaceEvents() {
+int RM_GetNotifyKeyspaceEvents(void) {
     return server.notify_keyspace_events;
 }
 
@@ -9337,7 +9337,7 @@ int RM_EventLoopAddOneShot(RedisModuleEventLoopOneShotFunc func, void *user_data
 
 /* This function will check the moduleEventLoopOneShots queue in order to
  * call the callback for the registered oneshot events. */
-static void eventLoopHandleOneShotEvents() {
+static void eventLoopHandleOneShotEvents(void) {
     pthread_mutex_lock(&moduleEventLoopMutex);
     if (moduleEventLoopOneShots) {
         while (listLength(moduleEventLoopOneShots)) {
@@ -10438,7 +10438,7 @@ int RM_ExportSharedAPI(RedisModuleCtx *ctx, const char *apiname, void *func) {
  *
  * Here is an example:
  *
- *     int ... myCommandImplementation() {
+ *     int ... myCommandImplementation(void) {
  *        if (getExternalAPIs() == 0) {
  *             reply with an error here if we cannot have the APIs
  *        }
@@ -10771,7 +10771,7 @@ size_t RM_MallocSizeDict(RedisModuleDict* dict) {
  * * Exactly 1 - Memory limit reached.
  * * Greater 1 - More memory used than the configured limit.
  */
-float RM_GetUsedMemoryRatio(){
+float RM_GetUsedMemoryRatio(void){
     float level;
     getMaxmemoryState(NULL, NULL, NULL, &level);
     return level;
@@ -10810,7 +10810,7 @@ static void moduleScanCallback(void *privdata, const dictEntry *de) {
 }
 
 /* Create a new cursor to be used with RedisModule_Scan */
-RedisModuleScanCursor *RM_ScanCursorCreate() {
+RedisModuleScanCursor *RM_ScanCursorCreate(void) {
     RedisModuleScanCursor* cursor = zmalloc(sizeof(*cursor));
     cursor->cursor = 0;
     cursor->done = 0;
@@ -13068,7 +13068,7 @@ int RM_GetLFU(RedisModuleKey *key, long long *lfu_freq) {
  *              // REDISMODULE_OPTIONS_ALLOW_NESTED_KEYSPACE_NOTIFICATIONS is not supported
  *        }
  */
-int RM_GetModuleOptionsAll() {
+int RM_GetModuleOptionsAll(void) {
     return _REDISMODULE_OPTIONS_FLAGS_NEXT - 1;
 }
 
@@ -13085,7 +13085,7 @@ int RM_GetModuleOptionsAll() {
  *              // REDISMODULE_CTX_FLAGS_MULTI is not supported
  *        }
  */
-int RM_GetContextFlagsAll() {
+int RM_GetContextFlagsAll(void) {
     return _REDISMODULE_CTX_FLAGS_NEXT - 1;
 }
 
@@ -13102,7 +13102,7 @@ int RM_GetContextFlagsAll() {
  *              // REDISMODULE_NOTIFY_LOADED is not supported
  *        }
  */
-int RM_GetKeyspaceNotificationFlagsAll() {
+int RM_GetKeyspaceNotificationFlagsAll(void) {
     return _REDISMODULE_NOTIFY_NEXT - 1;
 }
 
@@ -13110,7 +13110,7 @@ int RM_GetKeyspaceNotificationFlagsAll() {
  * Return the redis version in format of 0x00MMmmpp.
  * Example for 6.0.7 the return value will be 0x00060007.
  */
-int RM_GetServerVersion() {
+int RM_GetServerVersion(void) {
     return REDIS_VERSION_NUM;
 }
 
@@ -13119,7 +13119,7 @@ int RM_GetServerVersion() {
  * You can use that when calling RM_CreateDataType to know which fields of
  * RedisModuleTypeMethods are gonna be supported and which will be ignored.
  */
-int RM_GetTypeMethodVersion() {
+int RM_GetTypeMethodVersion(void) {
     return REDISMODULE_TYPE_METHOD_VERSION;
 }
 
diff --git a/src/monotonic.c b/src/monotonic.c
index 608fa351c..1d71962f3 100644
--- a/src/monotonic.c
+++ b/src/monotonic.c
@@ -32,11 +32,11 @@ static char monotonic_info_string[32];
 
 static long mono_ticksPerMicrosecond = 0;
 
-static monotime getMonotonicUs_x86() {
+static monotime getMonotonicUs_x86(void) {
     return __rdtsc() / mono_ticksPerMicrosecond;
 }
 
-static void monotonicInit_x86linux() {
+static void monotonicInit_x86linux(void) {
     const int bufflen = 256;
     char buf[bufflen];
     regex_t cpuGhzRegex, constTscRegex;
@@ -99,24 +99,24 @@ static void monotonicInit_x86linux() {
 static long mono_ticksPerMicrosecond = 0;
 
 /* Read the clock value.  */
-static inline uint64_t __cntvct() {
+static inline uint64_t __cntvct(void) {
     uint64_t virtual_timer_value;
     __asm__ volatile("mrs %0, cntvct_el0" : "=r"(virtual_timer_value));
     return virtual_timer_value;
 }
 
 /* Read the Count-timer Frequency.  */
-static inline uint32_t cntfrq_hz() {
+static inline uint32_t cntfrq_hz(void) {
     uint64_t virtual_freq_value;
     __asm__ volatile("mrs %0, cntfrq_el0" : "=r"(virtual_freq_value));
     return (uint32_t)virtual_freq_value;    /* top 32 bits are reserved */
 }
 
-static monotime getMonotonicUs_aarch64() {
+static monotime getMonotonicUs_aarch64(void) {
     return __cntvct() / mono_ticksPerMicrosecond;
 }
 
-static void monotonicInit_aarch64() {
+static void monotonicInit_aarch64(void) {
     mono_ticksPerMicrosecond = (long)cntfrq_hz() / 1000L / 1000L;
     if (mono_ticksPerMicrosecond == 0) {
         fprintf(stderr, "monotonic: aarch64, unable to determine clock rate");
@@ -130,7 +130,7 @@ static void monotonicInit_aarch64() {
 #endif
 
 
-static monotime getMonotonicUs_posix() {
+static monotime getMonotonicUs_posix(void) {
     /* clock_gettime() is specified in POSIX.1b (1993).  Even so, some systems
      * did not support this until much later.  CLOCK_MONOTONIC is technically
      * optional and may not be supported - but it appears to be universal.
@@ -140,7 +140,7 @@ static monotime getMonotonicUs_posix() {
     return ((uint64_t)ts.tv_sec) * 1000000 + ts.tv_nsec / 1000;
 }
 
-static void monotonicInit_posix() {
+static void monotonicInit_posix(void) {
     /* Ensure that CLOCK_MONOTONIC is supported.  This should be supported
      * on any reasonably current OS.  If the assertion below fails, provide
      * an appropriate alternate implementation.  */
@@ -155,7 +155,7 @@ static void monotonicInit_posix() {
 
 
 
-const char * monotonicInit() {
+const char * monotonicInit(void) {
     #if defined(USE_PROCESSOR_CLOCK) && defined(__x86_64__) && defined(__linux__)
     if (getMonotonicUs == NULL) monotonicInit_x86linux();
     #endif
@@ -169,11 +169,11 @@ const char * monotonicInit() {
     return monotonic_info_string;
 }
 
-const char *monotonicInfoString() {
+const char *monotonicInfoString(void) {
     return monotonic_info_string;
 }
 
-monotonic_clock_type monotonicGetType() {
+monotonic_clock_type monotonicGetType(void) {
     if (getMonotonicUs == getMonotonicUs_posix)
         return MONOTONIC_CLOCK_POSIX;
     return MONOTONIC_CLOCK_HW;
diff --git a/src/monotonic.h b/src/monotonic.h
index 32cf70638..b465f90b1 100644
--- a/src/monotonic.h
+++ b/src/monotonic.h
@@ -33,13 +33,13 @@ typedef enum monotonic_clock_type {
  * needs to be called once, it may be called additional times without impact.
  * Returns a printable string indicating the type of clock initialized.
  * (The returned string is static and doesn't need to be freed.)  */
-const char *monotonicInit();
+const char *monotonicInit(void);
 
 /* Return a string indicating the type of monotonic clock being used. */
-const char *monotonicInfoString();
+const char *monotonicInfoString(void);
 
 /* Return the type of monotonic clock being used. */
-monotonic_clock_type monotonicGetType();
+monotonic_clock_type monotonicGetType(void);
 
 /* Functions to measure elapsed time.  Example:
  *     monotime myTimer;
diff --git a/src/networking.c b/src/networking.c
index f8fb6bee2..25d2b4c34 100644
--- a/src/networking.c
+++ b/src/networking.c
@@ -3981,7 +3981,7 @@ void updatePausedActions(void) {
 
 /* Unblock all paused clients (ones that where blocked by BLOCKED_POSTPONE (possibly in processCommand).
  * This means they'll get re-processed in beforeSleep, and may get paused again if needed. */
-void unblockPostponedClients() {
+void unblockPostponedClients(void) {
     listNode *ln;
     listIter li;
     listRewind(server.postponed_clients, &li);
diff --git a/src/pubsub.c b/src/pubsub.c
index 2bbe40380..ed7350843 100644
--- a/src/pubsub.c
+++ b/src/pubsub.c
@@ -207,12 +207,12 @@ void addReplyPubsubPatUnsubscribed(client *c, robj *pattern) {
  *----------------------------------------------------------------------------*/
 
 /* Return the number of pubsub channels + patterns is handled. */
-int serverPubsubSubscriptionCount() {
+int serverPubsubSubscriptionCount(void) {
     return dictSize(server.pubsub_channels) + dictSize(server.pubsub_patterns);
 }
 
 /* Return the number of pubsub shard level channels is handled. */
-int serverPubsubShardSubscriptionCount() {
+int serverPubsubShardSubscriptionCount(void) {
     return dictSize(server.pubsubshard_channels);
 }
 
diff --git a/src/rand.c b/src/rand.c
index 09b0508f1..e1e98e63b 100644
--- a/src/rand.c
+++ b/src/rand.c
@@ -68,7 +68,7 @@
 static uint32_t x[3] = { X0, X1, X2 }, a[3] = { A0, A1, A2 }, c = C;
 static void next(void);
 
-int32_t redisLrand48() {
+int32_t redisLrand48(void) {
     next();
     return (((int32_t)x[2] << (N - 1)) + (x[1] >> 1));
 }
diff --git a/src/rand.h b/src/rand.h
index 1dce3e8b0..9884915a9 100644
--- a/src/rand.h
+++ b/src/rand.h
@@ -30,7 +30,7 @@
 #ifndef REDIS_RANDOM_H
 #define REDIS_RANDOM_H
 
-int32_t redisLrand48();
+int32_t redisLrand48(void);
 void redisSrand48(int32_t seedval);
 
 #define REDIS_LRAND48_MAX INT32_MAX
diff --git a/src/redis-benchmark.c b/src/redis-benchmark.c
index 95f54539c..2eb689e9f 100644
--- a/src/redis-benchmark.c
+++ b/src/redis-benchmark.c
@@ -192,7 +192,7 @@ static void writeHandler(aeEventLoop *el, int fd, void *privdata, int mask);
 static void createMissingClients(client c);
 static benchmarkThread *createBenchmarkThread(int index);
 static void freeBenchmarkThread(benchmarkThread *thread);
-static void freeBenchmarkThreads();
+static void freeBenchmarkThreads(void);
 static void *execBenchmarkThread(void *ptr);
 static clusterNode *createClusterNode(char *ip, int port);
 static redisConfig *getRedisConfig(const char *ip, int port,
@@ -201,7 +201,7 @@ static redisContext *getRedisContext(const char *ip, int port,
                                      const char *hostsocket);
 static void freeRedisConfig(redisConfig *cfg);
 static int fetchClusterSlotsConfiguration(client c);
-static void updateClusterSlotsConfiguration();
+static void updateClusterSlotsConfiguration(void);
 int showThroughput(struct aeEventLoop *eventLoop, long long id,
                    void *clientData);
 
@@ -958,7 +958,7 @@ static void showLatencyReport(void) {
     }
 }
 
-static void initBenchmarkThreads() {
+static void initBenchmarkThreads(void) {
     int i;
     if (config.threads) freeBenchmarkThreads();
     config.threads = zmalloc(config.num_threads * sizeof(benchmarkThread*));
@@ -968,7 +968,7 @@ static void initBenchmarkThreads() {
     }
 }
 
-static void startBenchmarkThreads() {
+static void startBenchmarkThreads(void) {
     int i;
     for (i = 0; i < config.num_threads; i++) {
         benchmarkThread *t = config.threads[i];
@@ -1035,7 +1035,7 @@ static void freeBenchmarkThread(benchmarkThread *thread) {
     zfree(thread);
 }
 
-static void freeBenchmarkThreads() {
+static void freeBenchmarkThreads(void) {
     int i = 0;
     for (; i < config.num_threads; i++) {
         benchmarkThread *thread = config.threads[i];
@@ -1096,7 +1096,7 @@ static void freeClusterNode(clusterNode *node) {
     zfree(node);
 }
 
-static void freeClusterNodes() {
+static void freeClusterNodes(void) {
     int i = 0;
     for (; i < config.cluster_node_count; i++) {
         clusterNode *n = config.cluster_nodes[i];
@@ -1118,7 +1118,7 @@ static clusterNode **addClusterNode(clusterNode *node) {
 /* TODO: This should be refactored to use CLUSTER SLOTS, the migrating/importing
  * information is anyway not used.
  */
-static int fetchClusterConfiguration() {
+static int fetchClusterConfiguration(void) {
     int success = 1;
     redisContext *ctx = NULL;
     redisReply *reply =  NULL;
@@ -1377,7 +1377,7 @@ cleanup:
 }
 
 /* Atomically update the new slots configuration. */
-static void updateClusterSlotsConfiguration() {
+static void updateClusterSlotsConfiguration(void) {
     pthread_mutex_lock(&config.is_updating_slots_mutex);
     atomicSet(config.is_updating_slots, 1);
     int i;
diff --git a/src/redis-cli.c b/src/redis-cli.c
index ad2c79840..62eccf610 100644
--- a/src/redis-cli.c
+++ b/src/redis-cli.c
@@ -848,7 +848,7 @@ static size_t cliLegacyCountCommands(struct commandDocs *commands, sds version)
 /* Gets the server version string by calling INFO SERVER.
  * Stores the result in config.server_version.
  * When not connected, or not possible, returns NULL. */
-static sds cliGetServerVersion() {
+static sds cliGetServerVersion(void) {
     static const char *key = "\nredis_version:";
     redisReply *serverInfo = NULL;
     char *pos;
@@ -1724,7 +1724,7 @@ static int cliConnect(int flags) {
 
 /* In cluster, if server replies ASK, we will redirect to a different node.
  * Before sending the real command, we need to send ASKING command first. */
-static int cliSendAsking() {
+static int cliSendAsking(void) {
     redisReply *reply;
 
     config.cluster_send_asking = 0;
@@ -2319,7 +2319,7 @@ static int cliReadReply(int output_raw_strings) {
 }
 
 /* Simultaneously wait for pubsub messages from redis and input on stdin. */
-static void cliWaitForMessagesOrStdin() {
+static void cliWaitForMessagesOrStdin(void) {
     int show_info = config.output != OUTPUT_RAW && (isatty(STDOUT_FILENO) ||
                                                     getenv("FAKETTY"));
     int use_color = show_info && isColorTerm();
@@ -2965,7 +2965,7 @@ static int parseOptions(int argc, char **argv) {
     return i;
 }
 
-static void parseEnv() {
+static void parseEnv(void) {
     /* Set auth from env, but do not overwrite CLI arguments if passed */
     char *auth = getenv(REDIS_CLI_AUTH_ENV);
     if (auth != NULL && config.conn_info.auth == NULL) {
@@ -5870,7 +5870,7 @@ static clusterManagerNode * clusterManagerGetNodeWithMostKeysInSlot(list *nodes,
  * in the cluster. If there are multiple masters with the same smaller
  * number of replicas, one at random is returned. */
 
-static clusterManagerNode *clusterManagerNodeWithLeastReplicas() {
+static clusterManagerNode *clusterManagerNodeWithLeastReplicas(void) {
     clusterManagerNode *node = NULL;
     int lowest_count = 0;
     listIter li;
@@ -5889,7 +5889,7 @@ static clusterManagerNode *clusterManagerNodeWithLeastReplicas() {
 
 /* This function returns a random master node, return NULL if none */
 
-static clusterManagerNode *clusterManagerNodeMasterRandom() {
+static clusterManagerNode *clusterManagerNodeMasterRandom(void) {
     int master_count = 0;
     int idx;
     listIter li;
@@ -8391,7 +8391,7 @@ int sendReplconf(const char* arg1, const char* arg2) {
     return res;
 }
 
-void sendCapa() {
+void sendCapa(void) {
     sendReplconf("capa", "eof");
 }
 
diff --git a/src/redismodule.h b/src/redismodule.h
index fff6ac9bc..049b0f340 100644
--- a/src/redismodule.h
+++ b/src/redismodule.h
@@ -976,7 +976,7 @@ REDISMODULE_API int (*RedisModule_GetSelectedDb)(RedisModuleCtx *ctx) REDISMODUL
 REDISMODULE_API int (*RedisModule_SelectDb)(RedisModuleCtx *ctx, int newid) REDISMODULE_ATTR;
 REDISMODULE_API int (*RedisModule_KeyExists)(RedisModuleCtx *ctx, RedisModuleString *keyname) REDISMODULE_ATTR;
 REDISMODULE_API RedisModuleKey * (*RedisModule_OpenKey)(RedisModuleCtx *ctx, RedisModuleString *keyname, int mode) REDISMODULE_ATTR;
-REDISMODULE_API int (*RedisModule_GetOpenKeyModesAll)() REDISMODULE_ATTR;
+REDISMODULE_API int (*RedisModule_GetOpenKeyModesAll)(void) REDISMODULE_ATTR;
 REDISMODULE_API void (*RedisModule_CloseKey)(RedisModuleKey *kp) REDISMODULE_ATTR;
 REDISMODULE_API int (*RedisModule_KeyType)(RedisModuleKey *kp) REDISMODULE_ATTR;
 REDISMODULE_API size_t (*RedisModule_ValueLength)(RedisModuleKey *kp) REDISMODULE_ATTR;
@@ -1098,7 +1098,7 @@ REDISMODULE_API int (*RedisModule_SetClientNameById)(uint64_t id, RedisModuleStr
 REDISMODULE_API int (*RedisModule_PublishMessage)(RedisModuleCtx *ctx, RedisModuleString *channel, RedisModuleString *message) REDISMODULE_ATTR;
 REDISMODULE_API int (*RedisModule_PublishMessageShard)(RedisModuleCtx *ctx, RedisModuleString *channel, RedisModuleString *message) REDISMODULE_ATTR;
 REDISMODULE_API int (*RedisModule_GetContextFlags)(RedisModuleCtx *ctx) REDISMODULE_ATTR;
-REDISMODULE_API int (*RedisModule_AvoidReplicaTraffic)() REDISMODULE_ATTR;
+REDISMODULE_API int (*RedisModule_AvoidReplicaTraffic)(void) REDISMODULE_ATTR;
 REDISMODULE_API void * (*RedisModule_PoolAlloc)(RedisModuleCtx *ctx, size_t bytes) REDISMODULE_ATTR;
 REDISMODULE_API RedisModuleType * (*RedisModule_CreateDataType)(RedisModuleCtx *ctx, const char *name, int encver, RedisModuleTypeMethods *typemethods) REDISMODULE_ATTR;
 REDISMODULE_API int (*RedisModule_ModuleTypeSetValue)(RedisModuleKey *key, RedisModuleType *mt, void *value) REDISMODULE_ATTR;
@@ -1201,17 +1201,17 @@ REDISMODULE_API RedisModuleBlockedClient * (*RedisModule_BlockClientOnKeys)(Redi
 REDISMODULE_API RedisModuleBlockedClient * (*RedisModule_BlockClientOnKeysWithFlags)(RedisModuleCtx *ctx, RedisModuleCmdFunc reply_callback, RedisModuleCmdFunc timeout_callback, void (*free_privdata)(RedisModuleCtx*,void*), long long timeout_ms, RedisModuleString **keys, int numkeys, void *privdata, int flags) REDISMODULE_ATTR;
 REDISMODULE_API void (*RedisModule_SignalKeyAsReady)(RedisModuleCtx *ctx, RedisModuleString *key) REDISMODULE_ATTR;
 REDISMODULE_API RedisModuleString * (*RedisModule_GetBlockedClientReadyKey)(RedisModuleCtx *ctx) REDISMODULE_ATTR;
-REDISMODULE_API RedisModuleScanCursor * (*RedisModule_ScanCursorCreate)() REDISMODULE_ATTR;
+REDISMODULE_API RedisModuleScanCursor * (*RedisModule_ScanCursorCreate)(void) REDISMODULE_ATTR;
 REDISMODULE_API void (*RedisModule_ScanCursorRestart)(RedisModuleScanCursor *cursor) REDISMODULE_ATTR;
 REDISMODULE_API void (*RedisModule_ScanCursorDestroy)(RedisModuleScanCursor *cursor) REDISMODULE_ATTR;
 REDISMODULE_API int (*RedisModule_Scan)(RedisModuleCtx *ctx, RedisModuleScanCursor *cursor, RedisModuleScanCB fn, void *privdata) REDISMODULE_ATTR;
 REDISMODULE_API int (*RedisModule_ScanKey)(RedisModuleKey *key, RedisModuleScanCursor *cursor, RedisModuleScanKeyCB fn, void *privdata) REDISMODULE_ATTR;
-REDISMODULE_API int (*RedisModule_GetContextFlagsAll)() REDISMODULE_ATTR;
-REDISMODULE_API int (*RedisModule_GetModuleOptionsAll)() REDISMODULE_ATTR;
-REDISMODULE_API int (*RedisModule_GetKeyspaceNotificationFlagsAll)() REDISMODULE_ATTR;
+REDISMODULE_API int (*RedisModule_GetContextFlagsAll)(void) REDISMODULE_ATTR;
+REDISMODULE_API int (*RedisModule_GetModuleOptionsAll)(void) REDISMODULE_ATTR;
+REDISMODULE_API int (*RedisModule_GetKeyspaceNotificationFlagsAll)(void) REDISMODULE_ATTR;
 REDISMODULE_API int (*RedisModule_IsSubEventSupported)(RedisModuleEvent event, uint64_t subevent) REDISMODULE_ATTR;
-REDISMODULE_API int (*RedisModule_GetServerVersion)() REDISMODULE_ATTR;
-REDISMODULE_API int (*RedisModule_GetTypeMethodVersion)() REDISMODULE_ATTR;
+REDISMODULE_API int (*RedisModule_GetServerVersion)(void) REDISMODULE_ATTR;
+REDISMODULE_API int (*RedisModule_GetTypeMethodVersion)(void) REDISMODULE_ATTR;
 REDISMODULE_API void (*RedisModule_Yield)(RedisModuleCtx *ctx, int flags, const char *busy_reply) REDISMODULE_ATTR;
 REDISMODULE_API RedisModuleBlockedClient * (*RedisModule_BlockClient)(RedisModuleCtx *ctx, RedisModuleCmdFunc reply_callback, RedisModuleCmdFunc timeout_callback, void (*free_privdata)(RedisModuleCtx*,void*), long long timeout_ms) REDISMODULE_ATTR;
 REDISMODULE_API void * (*RedisModule_BlockClientGetPrivateData)(RedisModuleBlockedClient *blocked_client) REDISMODULE_ATTR;
@@ -1234,7 +1234,7 @@ REDISMODULE_API void (*RedisModule_ThreadSafeContextUnlock)(RedisModuleCtx *ctx)
 REDISMODULE_API int (*RedisModule_SubscribeToKeyspaceEvents)(RedisModuleCtx *ctx, int types, RedisModuleNotificationFunc cb) REDISMODULE_ATTR;
 REDISMODULE_API int (*RedisModule_AddPostNotificationJob)(RedisModuleCtx *ctx, RedisModulePostNotificationJobFunc callback, void *pd, void (*free_pd)(void*)) REDISMODULE_ATTR;
 REDISMODULE_API int (*RedisModule_NotifyKeyspaceEvent)(RedisModuleCtx *ctx, int type, const char *event, RedisModuleString *key) REDISMODULE_ATTR;
-REDISMODULE_API int (*RedisModule_GetNotifyKeyspaceEvents)() REDISMODULE_ATTR;
+REDISMODULE_API int (*RedisModule_GetNotifyKeyspaceEvents)(void) REDISMODULE_ATTR;
 REDISMODULE_API int (*RedisModule_BlockedClientDisconnected)(RedisModuleCtx *ctx) REDISMODULE_ATTR;
 REDISMODULE_API void (*RedisModule_RegisterClusterMessageReceiver)(RedisModuleCtx *ctx, uint8_t type, RedisModuleClusterMessageReceiver callback) REDISMODULE_ATTR;
 REDISMODULE_API int (*RedisModule_SendClusterMessage)(RedisModuleCtx *ctx, const char *target_id, uint8_t type, const char *msg, uint32_t len) REDISMODULE_ATTR;
@@ -1263,7 +1263,7 @@ REDISMODULE_API int (*RedisModule_Fork)(RedisModuleForkDoneHandler cb, void *use
 REDISMODULE_API void (*RedisModule_SendChildHeartbeat)(double progress) REDISMODULE_ATTR;
 REDISMODULE_API int (*RedisModule_ExitFromChild)(int retcode) REDISMODULE_ATTR;
 REDISMODULE_API int (*RedisModule_KillForkChild)(int child_pid) REDISMODULE_ATTR;
-REDISMODULE_API float (*RedisModule_GetUsedMemoryRatio)() REDISMODULE_ATTR;
+REDISMODULE_API float (*RedisModule_GetUsedMemoryRatio)(void) REDISMODULE_ATTR;
 REDISMODULE_API size_t (*RedisModule_MallocSize)(void* ptr) REDISMODULE_ATTR;
 REDISMODULE_API size_t (*RedisModule_MallocUsableSize)(void *ptr) REDISMODULE_ATTR;
 REDISMODULE_API size_t (*RedisModule_MallocSizeString)(RedisModuleString* str) REDISMODULE_ATTR;
diff --git a/src/replication.c b/src/replication.c
index 260a405da..ca3287491 100644
--- a/src/replication.c
+++ b/src/replication.c
@@ -55,7 +55,7 @@ int cancelReplicationHandshake(int reconnect);
 int RDBGeneratedByReplication = 0;
 
 /* --------------------------- Utility functions ---------------------------- */
-static ConnectionType *connTypeOfReplication() {
+static ConnectionType *connTypeOfReplication(void) {
     if (server.tls_replication) {
         return connectionTypeTls();
     }
@@ -1793,7 +1793,7 @@ void replicationCreateMasterClient(connection *conn, int dbid) {
  * master-replica synchronization: if it fails after multiple attempts
  * the replica cannot be considered reliable and exists with an
  * error. */
-void restartAOFAfterSYNC() {
+void restartAOFAfterSYNC(void) {
     unsigned int tries, max_tries = 10;
     for (tries = 0; tries < max_tries; ++tries) {
         if (startAppendOnly() == C_OK) break;
@@ -1810,7 +1810,7 @@ void restartAOFAfterSYNC() {
     }
 }
 
-static int useDisklessLoad() {
+static int useDisklessLoad(void) {
     /* compute boolean decision to use diskless load */
     int enabled = server.repl_diskless_load == REPL_DISKLESS_LOAD_SWAPDB ||
            (server.repl_diskless_load == REPL_DISKLESS_LOAD_WHEN_DB_EMPTY && dbTotalServerKeyCount()==0);
@@ -1849,7 +1849,7 @@ void disklessLoadDiscardTempDb(redisDb *tempDb) {
  * we have no way to incrementally feed our replicas after that.
  * We want our replicas to resync with us as well, if we have any sub-replicas.
  * This is useful on readSyncBulkPayload in places where we just finished transferring db. */
-void replicationAttachToNewMaster() { 
+void replicationAttachToNewMaster(void) { 
     /* Replica starts to apply data from new master, we must discard the cached
      * master structure. */
     serverAssert(server.master == NULL);
@@ -3993,7 +3993,7 @@ static client *findReplica(char *host, int port) {
     return NULL;
 }
 
-const char *getFailoverStateString() {
+const char *getFailoverStateString(void) {
     switch(server.failover_state) {
         case NO_FAILOVER: return "no-failover";
         case FAILOVER_IN_PROGRESS: return "failover-in-progress";
@@ -4005,7 +4005,7 @@ const char *getFailoverStateString() {
 /* Resets the internal failover configuration, this needs
  * to be called after a failover either succeeds or fails
  * as it includes the client unpause. */
-void clearFailoverState() {
+void clearFailoverState(void) {
     server.failover_end_time = 0;
     server.force_failover = 0;
     zfree(server.target_replica_host);
diff --git a/src/script.c b/src/script.c
index dd0bd3a58..70680e3ea 100644
--- a/src/script.c
+++ b/src/script.c
@@ -60,16 +60,16 @@ static void enterScriptTimedoutMode(scriptRunCtx *run_ctx) {
     blockingOperationStarts();
 }
 
-int scriptIsTimedout() {
+int scriptIsTimedout(void) {
     return scriptIsRunning() && (curr_run_ctx->flags & SCRIPT_TIMEDOUT);
 }
 
-client* scriptGetClient() {
+client* scriptGetClient(void) {
     serverAssert(scriptIsRunning());
     return curr_run_ctx->c;
 }
 
-client* scriptGetCaller() {
+client* scriptGetCaller(void) {
     serverAssert(scriptIsRunning());
     return curr_run_ctx->original_client;
 }
@@ -269,16 +269,16 @@ void scriptResetRun(scriptRunCtx *run_ctx) {
 }
 
 /* return true if a script is currently running */
-int scriptIsRunning() {
+int scriptIsRunning(void) {
     return curr_run_ctx != NULL;
 }
 
-const char* scriptCurrFunction() {
+const char* scriptCurrFunction(void) {
     serverAssert(scriptIsRunning());
     return curr_run_ctx->funcname;
 }
 
-int scriptIsEval() {
+int scriptIsEval(void) {
     serverAssert(scriptIsRunning());
     return curr_run_ctx->flags & SCRIPT_EVAL_MODE;
 }
@@ -571,7 +571,7 @@ error:
     incrCommandStatsOnError(cmd, ERROR_COMMAND_REJECTED);
 }
 
-long long scriptRunDuration() {
+long long scriptRunDuration(void) {
     serverAssert(scriptIsRunning());
     return elapsedMs(curr_run_ctx->start_time);
 }
diff --git a/src/script.h b/src/script.h
index edcacd578..c487165d6 100644
--- a/src/script.h
+++ b/src/script.h
@@ -100,12 +100,12 @@ int scriptSetRepl(scriptRunCtx *r_ctx, int repl);
 void scriptCall(scriptRunCtx *r_ctx, sds *err);
 int scriptInterrupt(scriptRunCtx *r_ctx);
 void scriptKill(client *c, int is_eval);
-int scriptIsRunning();
-const char* scriptCurrFunction();
-int scriptIsEval();
-int scriptIsTimedout();
-client* scriptGetClient();
-client* scriptGetCaller();
-long long scriptRunDuration();
+int scriptIsRunning(void);
+const char* scriptCurrFunction(void);
+int scriptIsEval(void);
+int scriptIsTimedout(void);
+client* scriptGetClient(void);
+client* scriptGetCaller(void);
+long long scriptRunDuration(void);
 
 #endif /* __SCRIPT_H_ */
diff --git a/src/sentinel.c b/src/sentinel.c
index 3d5c3861c..326def135 100644
--- a/src/sentinel.c
+++ b/src/sentinel.c
@@ -1740,7 +1740,7 @@ const char *sentinelCheckCreateInstanceErrors(int role) {
 }
 
 /* init function for server.sentinel_config */
-void initializeSentinelConfig() {
+void initializeSentinelConfig(void) {
     server.sentinel_config = zmalloc(sizeof(struct sentinelConfig));
     server.sentinel_config->monitor_cfg = listCreate();
     server.sentinel_config->pre_monitor_cfg = listCreate();
@@ -1751,7 +1751,7 @@ void initializeSentinelConfig() {
 }
 
 /* destroy function for server.sentinel_config */
-void freeSentinelConfig() {
+void freeSentinelConfig(void) {
     /* release these three config queues since we will not use it anymore */
     listRelease(server.sentinel_config->pre_monitor_cfg);
     listRelease(server.sentinel_config->monitor_cfg);
@@ -3179,7 +3179,7 @@ void sentinelSendPeriodicCommands(sentinelRedisInstance *ri) {
 
 /* =========================== SENTINEL command ============================= */
 
-const char* getLogLevel() {
+const char* getLogLevel(void) {
    switch (server.verbosity) {
     case LL_DEBUG: return "debug";
     case LL_VERBOSE: return "verbose";
diff --git a/src/server.c b/src/server.c
index fff6c7082..381edabc6 100644
--- a/src/server.c
+++ b/src/server.c
@@ -656,11 +656,11 @@ const char *strChildType(int type) {
 
 /* Return true if there are active children processes doing RDB saving,
  * AOF rewriting, or some side process spawned by a loaded module. */
-int hasActiveChildProcess() {
+int hasActiveChildProcess(void) {
     return server.child_pid != -1;
 }
 
-void resetChildState() {
+void resetChildState(void) {
     server.child_type = CHILD_TYPE_NONE;
     server.child_pid = -1;
     server.stat_current_cow_peak = 0;
@@ -682,7 +682,7 @@ int isMutuallyExclusiveChildType(int type) {
 }
 
 /* Returns true when we're inside a long command that yielded to the event loop. */
-int isInsideYieldingLongCommand() {
+int isInsideYieldingLongCommand(void) {
     return scriptIsTimedout() || server.busy_module_yield_flags;
 }
 
@@ -1148,7 +1148,7 @@ void enterExecutionUnit(int update_cached_time, long long us) {
     }
 }
 
-void exitExecutionUnit() {
+void exitExecutionUnit(void) {
     --server.execution_nesting;
 }
 
@@ -1204,7 +1204,7 @@ void checkChildrenDone(void) {
 }
 
 /* Called from serverCron and cronUpdateMemoryStats to update cached memory metrics. */
-void cronUpdateMemoryStats() {
+void cronUpdateMemoryStats(void) {
     /* Record the max memory used since the server was started. */
     if (zmalloc_used_memory() > server.stat_peak_memory)
         server.stat_peak_memory = zmalloc_used_memory();
@@ -1518,14 +1518,14 @@ int serverCron(struct aeEventLoop *eventLoop, long long id, void *clientData) {
 }
 
 
-void blockingOperationStarts() {
+void blockingOperationStarts(void) {
     if(!server.blocking_op_nesting++){
         updateCachedTime(0);
         server.blocked_last_cron = server.mstime;
     }
 }
 
-void blockingOperationEnds() {
+void blockingOperationEnds(void) {
     if(!(--server.blocking_op_nesting)){
         server.blocked_last_cron = 0;
     }
@@ -1536,7 +1536,7 @@ void blockingOperationEnds() {
  * It attempts to do its duties at a similar rate as the configured server.hz,
  * and updates cronloops variable so that similarly to serverCron, the
  * run_with_period can be used. */
-void whileBlockedCron() {
+void whileBlockedCron(void) {
     /* Here we may want to perform some cron jobs (normally done server.hz times
      * per second). */
 
@@ -1954,7 +1954,7 @@ void createSharedObjects(void) {
     shared.maxstring = sdsnew("maxstring");
 }
 
-void initServerClientMemUsageBuckets() {
+void initServerClientMemUsageBuckets(void) {
     if (server.client_mem_usage_buckets)
         return;
     server.client_mem_usage_buckets = zmalloc(sizeof(clientMemUsageBucket)*CLIENT_MEM_USAGE_BUCKETS);
@@ -1964,7 +1964,7 @@ void initServerClientMemUsageBuckets() {
     }
 }
 
-void freeServerClientMemUsageBuckets() {
+void freeServerClientMemUsageBuckets(void) {
     if (!server.client_mem_usage_buckets)
         return;
     for (int j = 0; j < CLIENT_MEM_USAGE_BUCKETS; j++)
@@ -2717,7 +2717,7 @@ void initServer(void) {
         initServerClientMemUsageBuckets();
 }
 
-void initListeners() {
+void initListeners(void) {
     /* Setup listeners from server config for TCP/TLS/Unix */
     int conn_index;
     connListener *listener;
@@ -2794,7 +2794,7 @@ void initListeners() {
  * Specifically, creation of threads due to a race bug in ld.so, in which
  * Thread Local Storage initialization collides with dlopen call.
  * see: https://sourceware.org/bugzilla/show_bug.cgi?id=19329 */
-void InitServerLast() {
+void InitServerLast(void) {
     bioInit();
     initThreadedIO();
     set_jemalloc_bg_thread(server.jemalloc_bg_thread);
@@ -3304,7 +3304,7 @@ void updateCommandLatencyHistogram(struct hdr_histogram **latency_histogram, int
 /* Handle the alsoPropagate() API to handle commands that want to propagate
  * multiple separated commands. Note that alsoPropagate() is not affected
  * by CLIENT_PREVENT_PROP flag. */
-static void propagatePendingCommands() {
+static void propagatePendingCommands(void) {
     if (server.also_propagate.numops == 0)
         return;
 
@@ -3360,7 +3360,7 @@ static void propagatePendingCommands() {
  * currently with respect to replication and post jobs, but in the future there might
  * be other considerations. So we basically want the `postUnitOperations` to trigger
  * after the entire chain finished. */
-void postExecutionUnitOperations() {
+void postExecutionUnitOperations(void) {
     if (server.execution_nesting)
         return;
 
@@ -6505,7 +6505,7 @@ void setupChildSignalHandlers(void) {
  * of the parent process, e.g. fd(socket or flock) etc.
  * should close the resources not used by the child process, so that if the
  * parent restarts it can bind/lock despite the child possibly still running. */
-void closeChildUnusedResourceAfterFork() {
+void closeChildUnusedResourceAfterFork(void) {
     closeListeningSockets(0);
     if (server.cluster_enabled && server.cluster_config_file_lock_fd != -1)
         close(server.cluster_config_file_lock_fd);  /* don't care if this fails */
diff --git a/src/server.h b/src/server.h
index 222044ab9..bced3dbb8 100644
--- a/src/server.h
+++ b/src/server.h
@@ -1372,9 +1372,8 @@ typedef struct redisOp {
 /* Defines an array of Redis operations. There is an API to add to this
  * structure in an easy way.
  *
- * redisOpArrayInit();
- * redisOpArrayAppend();
- * redisOpArrayFree();
+ * int redisOpArrayAppend(redisOpArray *oa, int dbid, robj **argv, int argc, int target);
+ * void redisOpArrayFree(redisOpArray *oa);
  */
 typedef struct redisOpArray {
     redisOp *ops;
@@ -2472,14 +2471,14 @@ void moduleAcquireGIL(void);
 int moduleTryAcquireGIL(void);
 void moduleReleaseGIL(void);
 void moduleNotifyKeyspaceEvent(int type, const char *event, robj *key, int dbid);
-void firePostExecutionUnitJobs();
+void firePostExecutionUnitJobs(void);
 void moduleCallCommandFilters(client *c);
-void modulePostExecutionUnitOperations();
+void modulePostExecutionUnitOperations(void);
 void ModuleForkDoneHandler(int exitcode, int bysignal);
 int TerminateModuleForkChild(int child_pid, int wait);
 ssize_t rdbSaveModulesAux(rio *rdb, int when);
-int moduleAllDatatypesHandleErrors();
-int moduleAllModulesHandleReplAsyncLoad();
+int moduleAllDatatypesHandleErrors(void);
+int moduleAllModulesHandleReplAsyncLoad(void);
 sds modulesCollectInfo(sds info, dict *sections_dict, int for_crash_report, int sections);
 void moduleFireServerEvent(uint64_t eid, int subid, void *data);
 void processModuleLoadingProgressEvent(int is_aof);
@@ -2607,11 +2606,11 @@ void unpauseActions(pause_purpose purpose);
 uint32_t isPausedActions(uint32_t action_bitmask);
 uint32_t isPausedActionsWithUpdate(uint32_t action_bitmask);
 void updatePausedActions(void);
-void unblockPostponedClients();
+void unblockPostponedClients(void);
 void processEventsWhileBlocked(void);
-void whileBlockedCron();
-void blockingOperationStarts();
-void blockingOperationEnds();
+void whileBlockedCron(void);
+void blockingOperationStarts(void);
+void blockingOperationEnds(void);
 int handleClientsWithPendingWrites(void);
 int handleClientsWithPendingWritesUsingThreads(void);
 int handleClientsWithPendingReadsUsingThreads(void);
@@ -2777,7 +2776,7 @@ void replicationCron(void);
 void replicationStartPendingFork(void);
 void replicationHandleMasterDisconnection(void);
 void replicationCacheMaster(client *c);
-void resizeReplicationBacklog();
+void resizeReplicationBacklog(void);
 void replicationSetMaster(char *ip, int port);
 void replicationUnsetMaster(void);
 void refreshGoodSlavesCount(void);
@@ -2806,7 +2805,7 @@ void rdbPipeWriteHandlerConnRemoved(struct connection *conn);
 void clearFailoverState(void);
 void updateFailoverStatus(void);
 void abortFailover(const char *err);
-const char *getFailoverStateString();
+const char *getFailoverStateString(void);
 
 /* Generic persistence functions */
 void startLoadingFile(size_t size, char* filename, int rdbflags);
@@ -2840,7 +2839,7 @@ void stopAppendOnly(void);
 int startAppendOnly(void);
 void backgroundRewriteDoneHandler(int exitcode, int bysignal);
 void killAppendOnlyChild(void);
-void restartAOFAfterSYNC();
+void restartAOFAfterSYNC(void);
 void aofLoadManifestFromDisk(void);
 void aofOpenIfNeededOnServerStart(void);
 void aofManifestFree(aofManifest *am);
@@ -2857,8 +2856,8 @@ void receiveChildInfo(void);
 
 /* Fork helpers */
 int redisFork(int purpose);
-int hasActiveChildProcess();
-void resetChildState();
+int hasActiveChildProcess(void);
+void resetChildState(void);
 int isMutuallyExclusiveChildType(int type);
 
 /* acl.c -- Authentication related prototypes. */
@@ -2912,13 +2911,13 @@ int ACLLoadConfiguredUsers(void);
 robj *ACLDescribeUser(user *u);
 void ACLLoadUsersAtStartup(void);
 void addReplyCommandCategories(client *c, struct redisCommand *cmd);
-user *ACLCreateUnlinkedUser();
+user *ACLCreateUnlinkedUser(void);
 void ACLFreeUserAndKillClients(user *u);
 void addACLLogEntry(client *c, int reason, int context, int argpos, sds username, sds object);
 sds getAclErrorMessage(int acl_res, user *user, struct redisCommand *cmd, sds errored_val, int verbose);
 void ACLUpdateDefaultUserPassword(sds password);
 sds genRedisInfoStringACLStats(sds info);
-void ACLRecomputeCommandBitsFromCommandRulesAllUsers();
+void ACLRecomputeCommandBitsFromCommandRulesAllUsers(void);
 
 /* Sorted sets data type */
 
@@ -2990,7 +2989,7 @@ int zslLexValueLteMax(sds value, zlexrangespec *spec);
 
 /* Core functions */
 int getMaxmemoryState(size_t *total, size_t *logical, size_t *tofree, float *level);
-size_t freeMemoryGetNotCountedMemory();
+size_t freeMemoryGetNotCountedMemory(void);
 int overMaxmemoryAfterAlloc(size_t moremem);
 uint64_t getCommandFlags(client *c);
 int processCommand(client *c);
@@ -3011,11 +3010,11 @@ struct redisCommand *lookupCommandByCString(const char *s);
 struct redisCommand *lookupCommandOrOriginal(robj **argv, int argc);
 int commandCheckExistence(client *c, sds *err);
 int commandCheckArity(client *c, sds *err);
-void startCommandExecution();
+void startCommandExecution(void);
 int incrCommandStatsOnError(struct redisCommand *cmd, int flags);
 void call(client *c, int flags);
 void alsoPropagate(int dbid, robj **argv, int argc, int target);
-void postExecutionUnitOperations();
+void postExecutionUnitOperations(void);
 void redisOpArrayFree(redisOpArray *oa);
 void forceCommandPropagation(client *c, int flags);
 void preventCommandPropagation(client *c);
@@ -3047,7 +3046,7 @@ void incrementErrorCount(const char *fullerr, size_t namelen);
 void closeListeningSockets(int unlink_unix_socket);
 void updateCachedTime(int update_daylight_info);
 void enterExecutionUnit(int update_cached_time, long long us);
-void exitExecutionUnit();
+void exitExecutionUnit(void);
 void resetServerStats(void);
 void activeDefragCycle(void);
 unsigned int getLRUClock(void);
@@ -3121,8 +3120,8 @@ int pubsubUnsubscribeAllPatterns(client *c, int notify);
 int pubsubPublishMessage(robj *channel, robj *message, int sharded);
 int pubsubPublishMessageAndPropagateToCluster(robj *channel, robj *message, int sharded);
 void addReplyPubsubMessage(client *c, robj *channel, robj *msg, robj *message_bulk);
-int serverPubsubSubscriptionCount();
-int serverPubsubShardSubscriptionCount();
+int serverPubsubSubscriptionCount(void);
+int serverPubsubShardSubscriptionCount(void);
 size_t pubsubMemOverhead(client *c);
 
 /* Keyspace events notification */
@@ -3176,12 +3175,12 @@ struct rewriteConfigState; /* Forward declaration to export API. */
 int rewriteConfigRewriteLine(struct rewriteConfigState *state, const char *option, sds line, int force);
 void rewriteConfigMarkAsProcessed(struct rewriteConfigState *state, const char *option);
 int rewriteConfig(char *path, int force_write);
-void initConfigValues();
+void initConfigValues(void);
 void removeConfig(sds name);
-sds getConfigDebugInfo();
+sds getConfigDebugInfo(void);
 int allowProtectedAction(int config, client *c);
-void initServerClientMemUsageBuckets();
-void freeServerClientMemUsageBuckets();
+void initServerClientMemUsageBuckets(void);
+void freeServerClientMemUsageBuckets(void);
 
 /* Module Configuration */
 typedef struct ModuleConfig ModuleConfig;
@@ -3249,7 +3248,7 @@ robj *dbUnshareStringValue(redisDb *db, robj *key, robj *o);
 long long emptyData(int dbnum, int flags, void(callback)(dict*));
 long long emptyDbStructure(redisDb *dbarray, int dbnum, int async, void(callback)(dict*));
 void flushAllDataAndResetRDB(int flags);
-long long dbTotalServerKeyCount();
+long long dbTotalServerKeyCount(void);
 redisDb *initTempDb(void);
 void discardTempDb(redisDb *tempDb, void(callback)(dict*));
 
@@ -3326,16 +3325,16 @@ sds luaCreateFunction(client *c, robj *body);
 void luaLdbLineHook(lua_State *lua, lua_Debug *ar);
 void freeLuaScriptsAsync(dict *lua_scripts);
 void freeFunctionsAsync(functionsLibCtx *lib_ctx);
-int ldbIsEnabled();
+int ldbIsEnabled(void);
 void ldbLog(sds entry);
 void ldbLogRedisReply(char *reply);
 void sha1hex(char *digest, char *script, size_t len);
-unsigned long evalMemory();
-dict* evalScriptsDict();
-unsigned long evalScriptsMemory();
+unsigned long evalMemory(void);
+dict* evalScriptsDict(void);
+unsigned long evalScriptsMemory(void);
 uint64_t evalGetCommandFlags(client *c, uint64_t orig_flags);
 uint64_t fcallGetCommandFlags(client *c, uint64_t orig_flags);
-int isInsideYieldingLongCommand();
+int isInsideYieldingLongCommand(void);
 
 typedef struct luaScript {
     uint64_t flags;
@@ -3691,7 +3690,7 @@ dict *genInfoSectionDict(robj **argv, int argc, char **defaults, int *out_all, i
 void releaseInfoSectionDict(dict *sec);
 sds genRedisInfoString(dict *section_dict, int all_sections, int everything);
 sds genModulesInfoString(sds info);
-void applyWatchdogPeriod();
+void applyWatchdogPeriod(void);
 void watchdogScheduleSignal(int period);
 void serverLogHexDump(int level, char *descr, void *value, size_t len);
 int memtest_preserving_test(unsigned long *m, size_t bytes, int passes);
diff --git a/src/socket.c b/src/socket.c
index cecbd4288..0cfb2e4ec 100644
--- a/src/socket.c
+++ b/src/socket.c
@@ -464,7 +464,7 @@ int connRecvTimeout(connection *conn, long long ms) {
     return anetRecvTimeout(NULL, conn->fd, ms);
 }
 
-int RedisRegisterConnectionTypeSocket()
+int RedisRegisterConnectionTypeSocket(void)
 {
     return connTypeRegister(&CT_Socket);
 }
diff --git a/src/tls.c b/src/tls.c
index 6e8c8531d..94cba63f1 100644
--- a/src/tls.c
+++ b/src/tls.c
@@ -1062,13 +1062,13 @@ static const char *connTLSGetType(connection *conn_) {
     return CONN_TYPE_TLS;
 }
 
-static int tlsHasPendingData() {
+static int tlsHasPendingData(void) {
     if (!pending_list)
         return 0;
     return listLength(pending_list) > 0;
 }
 
-static int tlsProcessPendingData() {
+static int tlsProcessPendingData(void) {
     listIter li;
     listNode *ln;
 
@@ -1151,13 +1151,13 @@ static ConnectionType CT_TLS = {
     .get_peer_cert = connTLSGetPeerCert,
 };
 
-int RedisRegisterConnectionTypeTLS() {
+int RedisRegisterConnectionTypeTLS(void) {
     return connTypeRegister(&CT_TLS);
 }
 
 #else   /* USE_OPENSSL */
 
-int RedisRegisterConnectionTypeTLS() {
+int RedisRegisterConnectionTypeTLS(void) {
     serverLog(LL_VERBOSE, "Connection type %s not builtin", CONN_TYPE_TLS);
     return C_ERR;
 }
diff --git a/src/unix.c b/src/unix.c
index d85e200d3..73e56d4a0 100644
--- a/src/unix.c
+++ b/src/unix.c
@@ -200,7 +200,7 @@ static ConnectionType CT_Unix = {
     .process_pending_data = NULL,
 };
 
-int RedisRegisterConnectionTypeUnix()
+int RedisRegisterConnectionTypeUnix(void)
 {
     return connTypeRegister(&CT_Unix);
 }
diff --git a/src/ziplist.c b/src/ziplist.c
index c3aa65633..c891625a9 100644
--- a/src/ziplist.c
+++ b/src/ziplist.c
@@ -1694,7 +1694,7 @@ unsigned int ziplistRandomPairsUnique(unsigned char *zl, unsigned int count, zip
 
 #define debug(f, ...) { if (DEBUG) printf(f, __VA_ARGS__); }
 
-static unsigned char *createList() {
+static unsigned char *createList(void) {
     unsigned char *zl = ziplistNew();
     zl = ziplistPush(zl, (unsigned char*)"foo", 3, ZIPLIST_TAIL);
     zl = ziplistPush(zl, (unsigned char*)"quux", 4, ZIPLIST_TAIL);
@@ -1703,7 +1703,7 @@ static unsigned char *createList() {
     return zl;
 }
 
-static unsigned char *createIntList() {
+static unsigned char *createIntList(void) {
     unsigned char *zl = ziplistNew();
     char buf[32];
 
diff --git a/src/zmalloc.c b/src/zmalloc.c
index 08ec64fc4..bbfa38651 100644
--- a/src/zmalloc.c
+++ b/src/zmalloc.c
@@ -656,7 +656,7 @@ void set_jemalloc_bg_thread(int enable) {
     je_mallctl("background_thread", NULL, 0, &val, 1);
 }
 
-int jemalloc_purge() {
+int jemalloc_purge(void) {
     /* return all unused (reserved) pages to the OS */
     char tmp[32];
     unsigned narenas = 0;
@@ -682,7 +682,7 @@ void set_jemalloc_bg_thread(int enable) {
     ((void)(enable));
 }
 
-int jemalloc_purge() {
+int jemalloc_purge(void) {
     return 0;
 }
 
diff --git a/src/zmalloc.h b/src/zmalloc.h
index 499cb7ec8..1ff66a635 100644
--- a/src/zmalloc.h
+++ b/src/zmalloc.h
@@ -120,7 +120,7 @@ void zmalloc_set_oom_handler(void (*oom_handler)(size_t));
 size_t zmalloc_get_rss(void);
 int zmalloc_get_allocator_info(size_t *allocated, size_t *active, size_t *resident);
 void set_jemalloc_bg_thread(int enable);
-int jemalloc_purge();
+int jemalloc_purge(void);
 size_t zmalloc_get_private_dirty(long pid);
 size_t zmalloc_get_smap_bytes_by_field(char *field, long pid);
 size_t zmalloc_get_memory_size(void);
diff --git a/tests/modules/blockonkeys.c b/tests/modules/blockonkeys.c
index 8f4353a55..bc3b6b1a4 100644
--- a/tests/modules/blockonkeys.c
+++ b/tests/modules/blockonkeys.c
@@ -21,7 +21,7 @@ typedef struct {
 
 static RedisModuleType *fsltype = NULL;
 
-fsl_t *fsl_type_create() {
+fsl_t *fsl_type_create(void) {
     fsl_t *o;
     o = RedisModule_Alloc(sizeof(*o));
     o->length = 0;