Please Clang 15

    CRT.c:1015:14: error: a function declaration without a prototype is deprecated in all versions of C [-Werror,-Wstrict-prototypes]
    void CRT_done() {
                 ^
                  void

CRT.c

@@ -1012,7 +1012,7 @@ IGNORE_WCASTQUAL_END
    CRT_degreeSign = initDegreeSign();
 }
 
-void CRT_done() {
+void CRT_done(void) {
    int resetColor = CRT_colors ? CRT_colors[RESET_COLOR] : CRT_colorSchemes[COLORSCHEME_DEFAULT][RESET_COLOR];
 
    attron(resetColor);
@@ -1033,7 +1033,7 @@ void CRT_fatalError(const char* note) {
    exit(2);
 }
 
-int CRT_readKey() {
+int CRT_readKey(void) {
    nocbreak();
    cbreak();
    nodelay(stdscr, FALSE);
@@ -1042,13 +1042,13 @@ int CRT_readKey() {
    return ret;
 }
 
-void CRT_disableDelay() {
+void CRT_disableDelay(void) {
    nocbreak();
    cbreak();
    nodelay(stdscr, TRUE);
 }
 
-void CRT_enableDelay() {
+void CRT_enableDelay(void) {
    halfdelay(*CRT_delay);
 }
 

MainPanel.c

@@ -210,7 +210,7 @@ const PanelClass MainPanel_class = {
    .printHeader = MainPanel_printHeader
 };
 
-MainPanel* MainPanel_new() {
+MainPanel* MainPanel_new(void) {
    MainPanel* this = AllocThis(MainPanel);
    Panel_init((Panel*) this, 1, 1, 1, 1, Class(Process), false, FunctionBar_new(Settings_isReadonly() ? MainFunctions_ro : MainFunctions, NULL, NULL));
    this->keys = xCalloc(KEY_MAX, sizeof(Htop_Action));

MetersPanel.c

@@ -33,7 +33,7 @@ static const char* const MetersMovingKeys[] = {"Space", "Enter", "Up", "Dn", "<-
 static const int MetersMovingEvents[] = {' ', 13, KEY_UP, KEY_DOWN, KEY_LEFT, KEY_RIGHT, ERR, KEY_DC, KEY_F(10)};
 static FunctionBar* Meters_movingBar = NULL;
 
-void MetersPanel_cleanup() {
+void MetersPanel_cleanup(void) {
    if (Meters_movingBar) {
       FunctionBar_delete(Meters_movingBar);
       Meters_movingBar = NULL;

Process.c

@@ -44,7 +44,7 @@ static uid_t Process_getuid = (uid_t)-1;
 int Process_pidDigits = PROCESS_MIN_PID_DIGITS;
 int Process_uidDigits = PROCESS_MIN_UID_DIGITS;
 
-void Process_setupColumnWidths() {
+void Process_setupColumnWidths(void) {
    int maxPid = Platform_getMaxPid();
    if (maxPid == -1)
       return;
@@ -1240,7 +1240,7 @@ void Process_updateExe(Process* this, const char* exe) {
 
 uint8_t Process_fieldWidths[LAST_PROCESSFIELD] = { 0 };
 
-void Process_resetFieldWidths() {
+void Process_resetFieldWidths(void) {
    for (size_t i = 0; i < LAST_PROCESSFIELD; i++) {
       if (!Process_fields[i].autoWidth)
          continue;

UsersTable.c

@@ -17,7 +17,7 @@ in the source distribution for its full text.
 #include "XUtils.h"
 
 
-UsersTable* UsersTable_new() {
+UsersTable* UsersTable_new(void) {
    UsersTable* this;
    this = xMalloc(sizeof(UsersTable));
    this->users = Hashtable_new(10, true);

XUtils.c

@@ -21,7 +21,7 @@ in the source distribution for its full text.
 #include "CRT.h"
 
 
-void fail() {
+void fail(void) {
    CRT_done();
    abort();
 

linux/Platform.c

@@ -250,7 +250,7 @@ const MeterClass* const Platform_meterTypes[] = {
    NULL
 };
 
-int Platform_getUptime() {
+int Platform_getUptime(void) {
    double uptime = 0;
    FILE* fd = fopen(PROCDIR "/uptime", "r");
    if (fd) {
@@ -285,7 +285,7 @@ void Platform_getLoadAverage(double* one, double* five, double* fifteen) {
    *fifteen = NAN;
 }
 
-int Platform_getMaxPid() {
+int Platform_getMaxPid(void) {
    FILE* file = fopen(PROCDIR "/sys/kernel/pid_max", "r");
    if (!file)
       return -1;