Remove superfluous casts

-  Every non-const pointer converts automatically to void *.
-  Every pointer converts automatically to void *.
-  void * converts to any other pointer.
-  const void * converts to any other const pointer.
-  Integer variables convert to each other.

I changed the declaration of a few variables in order to allow removing
a cast.

However, I didn't attempt to edit casts inside comparisons, since they
are very delicate.  I also kept casts in variadic functions, since they
are necessary, and in allocation functions, because I have other plans
for them.

I also changed a few casts to int that are better as ptrdiff_t.

This change has triggered some warnings about const correctness issues,
which have also been fixed in this patch (see for example src/login.c).

Signed-off-by: Alejandro Colomar <alx@kernel.org>

libmisc/addgrps.c

@@ -100,7 +100,7 @@ int add_groups (const char *list)
 	}
 
 	if (added) {
-		ret = setgroups ((size_t)ngroups, grouplist);
+		ret = setgroups (ngroups, grouplist);
 		free (grouplist);
 		return ret;
 	}

libmisc/age.c

@@ -139,7 +139,7 @@ int expire (const struct passwd *pw, /*@null@*/const struct spwd *sp)
 
 void agecheck (/*@null@*/const struct spwd *sp)
 {
-	long now = (long) time(NULL) / SCALE;
+	long now = time(NULL) / SCALE;
 	long remain;
 
 	if (NULL == sp) {

libmisc/audit_help.c

@@ -62,7 +62,7 @@ void audit_logger (int type, unused const char *pgname, const char *op,
 		return;
 	} else {
 		audit_log_acct_message (audit_fd, type, NULL, op, name, id,
-		                        NULL, NULL, NULL, (int) result);
+		                        NULL, NULL, NULL, result);
 	}
 }
 
@@ -77,7 +77,7 @@ void audit_logger_message (const char *message, shadow_audit_result result)
 		                        NULL, /* hostname */
 		                        NULL, /* addr */
 		                        NULL, /* tty */
-		                        (int) result);
+		                        result);
 	}
 }
 

libmisc/chowntty.c

@@ -51,7 +51,7 @@ void chown_tty (const struct passwd *info)
 	 */
 
 	if (   (fchown (STDIN_FILENO, info->pw_uid, gid) != 0)
-	    || (fchmod (STDIN_FILENO, (mode_t)getdef_num ("TTYPERM", 0600)) != 0)) {
+	    || (fchmod (STDIN_FILENO, getdef_num ("TTYPERM", 0600)) != 0)) {
 		int err = errno;
 		FILE *shadow_logfd = log_get_logfd();
 

libmisc/cleanup_group.c

@@ -22,7 +22,7 @@
  */
 void cleanup_report_add_group (void *group_name)
 {
-	const char *name = (const char *)group_name;
+	const char *name = group_name;
 
 	SYSLOG ((LOG_ERR, "failed to add group %s", name));
 #ifdef WITH_AUDIT
@@ -40,7 +40,7 @@ void cleanup_report_add_group (void *group_name)
  */
 void cleanup_report_del_group (void *group_name)
 {
-	const char *name = (const char *)group_name;
+	const char *name = group_name;
 
 	SYSLOG ((LOG_ERR, "failed to remove group %s", name));
 #ifdef WITH_AUDIT
@@ -95,7 +95,7 @@ void cleanup_report_mod_gshadow (void *cleanup_info)
  */
 void cleanup_report_add_group_group (void *group_name)
 {
-	const char *name = (const char *)group_name;
+	const char *name = group_name;
 
 	SYSLOG ((LOG_ERR, "failed to add group %s to %s", name, gr_dbname ()));
 #ifdef WITH_AUDIT
@@ -115,7 +115,7 @@ void cleanup_report_add_group_group (void *group_name)
  */
 void cleanup_report_add_group_gshadow (void *group_name)
 {
-	const char *name = (const char *)group_name;
+	const char *name = group_name;
 
 	SYSLOG ((LOG_ERR, "failed to add group %s to %s", name, sgr_dbname ()));
 #ifdef WITH_AUDIT
@@ -136,7 +136,7 @@ void cleanup_report_add_group_gshadow (void *group_name)
  */
 void cleanup_report_del_group_group (void *group_name)
 {
-	const char *name = (const char *)group_name;
+	const char *name = group_name;
 
 	SYSLOG ((LOG_ERR,
 	         "failed to remove group %s from %s",
@@ -159,7 +159,7 @@ void cleanup_report_del_group_group (void *group_name)
  */
 void cleanup_report_del_group_gshadow (void *group_name)
 {
-	const char *name = (const char *)group_name;
+	const char *name = group_name;
 
 	SYSLOG ((LOG_ERR,
 	         "failed to remove group %s from %s",

libmisc/cleanup_user.c

@@ -22,7 +22,7 @@
  */
 void cleanup_report_add_user (void *user_name)
 {
-	const char *name = (const char *)user_name;
+	const char *name = user_name;
 
 	SYSLOG ((LOG_ERR, "failed to add user %s", name));
 #ifdef WITH_AUDIT
@@ -59,7 +59,7 @@ void cleanup_report_mod_passwd (void *cleanup_info)
  */
 void cleanup_report_add_user_passwd (void *user_name)
 {
-	const char *name = (const char *)user_name;
+	const char *name = user_name;
 
 	SYSLOG ((LOG_ERR, "failed to add user %s to %s", name, pw_dbname ()));
 #ifdef WITH_AUDIT
@@ -79,7 +79,7 @@ void cleanup_report_add_user_passwd (void *user_name)
  */
 void cleanup_report_add_user_shadow (void *user_name)
 {
-	const char *name = (const char *)user_name;
+	const char *name = user_name;
 
 	SYSLOG ((LOG_ERR, "failed to add user %s to %s", name, spw_dbname ()));
 #ifdef WITH_AUDIT

libmisc/console.c

@@ -70,7 +70,7 @@ static bool is_listed (const char *cfgin, const char *tty, bool def)
 	 * See if this tty is listed in the console file.
 	 */
 
-	while (fgets (buf, (int) sizeof (buf), fp) != NULL) {
+	while (fgets (buf, sizeof (buf), fp) != NULL) {
 		/* Remove optional trailing '\n'. */
 		buf[strcspn (buf, "\n")] = '\0';
 		if (strcmp (buf, tty) == 0) {

libmisc/copydir.c

@@ -768,7 +768,7 @@ static ssize_t full_write(int fd, const void *buf, size_t count) {
 
 		written += res;
 		buf = (const unsigned char*)buf + res;
-		count -= (size_t)res;
+		count -= res;
 	}
 
 	return written;
@@ -850,7 +850,7 @@ static int copy_file (const struct path_info *src, const struct path_info *dst,
 			break;
 		}
 
-		if (full_write (ofd, buf, (size_t)cnt) < 0) {
+		if (full_write (ofd, buf, cnt) < 0) {
 			(void) close (ofd);
 			(void) close (ifd);
 			return -1;

libmisc/failure.c

@@ -53,7 +53,7 @@ void failure (uid_t uid, const char *tty, struct faillog *fl)
 	 */
 
 	if (   (lseek (fd, offset_uid, SEEK_SET) != offset_uid)
-	    || (read (fd, (char *) fl, sizeof *fl) != (ssize_t) sizeof *fl)) {
+	    || (read (fd, fl, sizeof *fl) != (ssize_t) sizeof *fl)) {
 		/* This is not necessarily a failure. The file is
 		 * initially zero length.
 		 *
@@ -86,7 +86,7 @@ void failure (uid_t uid, const char *tty, struct faillog *fl)
 	 */
 
 	if (   (lseek (fd, offset_uid, SEEK_SET) != offset_uid)
-	    || (write (fd, (char *) fl, sizeof *fl) != (ssize_t) sizeof *fl)
+	    || (write (fd, fl, sizeof *fl) != (ssize_t) sizeof *fl)
 	    || (close (fd) != 0)) {
 		SYSLOG ((LOG_WARN,
 		         "Can't write faillog entry for UID %lu in %s.",
@@ -163,7 +163,7 @@ int failcheck (uid_t uid, struct faillog *fl, bool failed)
 	 */
 
 	if (   (lseek (fd, offset_uid, SEEK_SET) != offset_uid)
-	    || (read (fd, (char *) fl, sizeof *fl) != (ssize_t) sizeof *fl)) {
+	    || (read (fd, fl, sizeof *fl) != (ssize_t) sizeof *fl)) {
 		(void) close (fd);
 		return 1;
 	}
@@ -185,7 +185,7 @@ int failcheck (uid_t uid, struct faillog *fl, bool failed)
 		fail.fail_cnt = 0;
 
 		if (   (lseek (fd, offset_uid, SEEK_SET) != offset_uid)
-		    || (write (fd, (const void *) &fail, sizeof fail) != (ssize_t) sizeof fail)
+		    || (write (fd, &fail, sizeof fail) != (ssize_t) sizeof fail)
 		    || (close (fd) != 0)) {
 			SYSLOG ((LOG_WARN,
 			         "Can't reset faillog entry for UID %lu in %s.",
@@ -278,7 +278,7 @@ void failtmp (const char *username, const struct utmp *failent)
 	 * Append the new failure record and close the log file.
 	 */
 
-	if (   (write (fd, (const void *) failent, sizeof *failent) != (ssize_t) sizeof *failent)
+	if (   (write (fd, failent, sizeof *failent) != (ssize_t) sizeof *failent)
 	    || (close (fd) != 0)) {
 		SYSLOG ((LOG_WARN,
 		         "Can't append failure of user %s to %s.",

libmisc/find_new_gid.c

@@ -40,15 +40,14 @@ static int get_ranges (bool sys_group, gid_t *min_id, gid_t *max_id,
 		*preferred_min = (gid_t) 1;
 
 		/* Get the minimum ID range from login.defs or default to 101 */
-		*min_id = (gid_t) getdef_ulong ("SYS_GID_MIN", 101UL);
+		*min_id = getdef_ulong ("SYS_GID_MIN", 101UL);
 
 		/*
 		 * If SYS_GID_MAX is unspecified, we should assume it to be one
 		 * less than the GID_MIN (which is reserved for non-system accounts)
 		 */
-		gid_def_max = (gid_t) getdef_ulong ("GID_MIN", 1000UL) - 1;
-		*max_id = (gid_t) getdef_ulong ("SYS_GID_MAX",
-				(unsigned long) gid_def_max);
+		gid_def_max = getdef_ulong ("GID_MIN", 1000UL) - 1;
+		*max_id = getdef_ulong ("SYS_GID_MAX", gid_def_max);
 
 		/* Check that the ranges make sense */
 		if (*max_id < *min_id) {
@@ -71,8 +70,8 @@ static int get_ranges (bool sys_group, gid_t *min_id, gid_t *max_id,
 		/* Non-system groups */
 
 		/* Get the values from login.defs or use reasonable defaults */
-		*min_id = (gid_t) getdef_ulong ("GID_MIN", 1000UL);
-		*max_id = (gid_t) getdef_ulong ("GID_MAX", 60000UL);
+		*min_id = getdef_ulong ("GID_MIN", 1000UL);
+		*max_id = getdef_ulong ("GID_MAX", 60000UL);
 
 		/*
 		 * The preferred minimum should match the standard ID minimum

libmisc/find_new_uid.c

@@ -40,15 +40,14 @@ static int get_ranges (bool sys_user, uid_t *min_id, uid_t *max_id,
 		*preferred_min = (uid_t) 1;
 
 		/* Get the minimum ID range from login.defs or default to 101 */
-		*min_id = (uid_t) getdef_ulong ("SYS_UID_MIN", 101UL);
+		*min_id = getdef_ulong ("SYS_UID_MIN", 101UL);
 
 		/*
 		 * If SYS_UID_MAX is unspecified, we should assume it to be one
 		 * less than the UID_MIN (which is reserved for non-system accounts)
 		 */
-		uid_def_max = (uid_t) getdef_ulong ("UID_MIN", 1000UL) - 1;
-		*max_id = (uid_t) getdef_ulong ("SYS_UID_MAX",
-				(unsigned long) uid_def_max);
+		uid_def_max = getdef_ulong ("UID_MIN", 1000UL) - 1;
+		*max_id = getdef_ulong ("SYS_UID_MAX", uid_def_max);
 
 		/* Check that the ranges make sense */
 		if (*max_id < *min_id) {
@@ -71,8 +70,8 @@ static int get_ranges (bool sys_user, uid_t *min_id, uid_t *max_id,
 		/* Non-system users */
 
 		/* Get the values from login.defs or use reasonable defaults */
-		*min_id = (uid_t) getdef_ulong ("UID_MIN", 1000UL);
-		*max_id = (uid_t) getdef_ulong ("UID_MAX", 60000UL);
+		*min_id = getdef_ulong ("UID_MIN", 1000UL);
+		*max_id = getdef_ulong ("UID_MAX", 60000UL);
 
 		/*
 		 * The preferred minimum should match the standard ID minimum

libmisc/getgr_nam_gid.c

@@ -36,7 +36,7 @@ extern /*@only@*//*@null@*/struct group *getgr_nam_gid (/*@null@*/const char *gr
 	    && ('\0' == *endptr)
 	    && (ERANGE != errno)
 	    && (/*@+longintegral@*/gid == (gid_t)gid)/*@=longintegral@*/) {
-		return xgetgrgid ((gid_t) gid);
+		return xgetgrgid (gid);
 	}
 	return xgetgrnam (grname);
 }

libmisc/gettime.c

@@ -61,7 +61,7 @@
 			 fallback, epoch);
 	} else {
 		/* Valid */
-		return (time_t)epoch;
+		return epoch;
 	}
 
 	return fallback;

libmisc/hushed.c

@@ -66,7 +66,7 @@ bool hushed (const char *username)
 	if (NULL == fp) {
 		return false;
 	}
-	for (found = false; !found && (fgets (buf, (int) sizeof buf, fp) == buf);) {
+	for (found = false; !found && (fgets (buf, sizeof buf, fp) == buf);) {
 		buf[strcspn (buf, "\n")] = '\0';
 		found = (strcmp (buf, pw->pw_shell) == 0) ||
 		        (strcmp (buf, pw->pw_name) == 0);

libmisc/isexpired.c

@@ -40,7 +40,7 @@ int isexpired (const struct passwd *pw, /*@null@*/const struct spwd *sp)
 {
 	long now;
 
-	now = (long) time(NULL) / SCALE;
+	now = time(NULL) / SCALE;
 
 	if (NULL == sp) {
 		return 0;

libmisc/limits.c

@@ -68,7 +68,7 @@ static int setrlimit_value (unsigned int resource,
 			return 0;
 		}
 		longlimit *= multiplier;
-		limit = (rlim_t)longlimit;
+		limit = longlimit;
 		if (longlimit != limit)
 		{
 			/* FIXME: Again, silent error handling...
@@ -95,7 +95,7 @@ static int set_prio (const char *value)
 	    || (prio != (int) prio)) {
 		return 0;
 	}
-	if (setpriority (PRIO_PROCESS, 0, (int) prio) != 0) {
+	if (setpriority (PRIO_PROCESS, 0, prio) != 0) {
 		return LOGIN_ERROR_RLIMIT;
 	}
 	return 0;
@@ -111,7 +111,7 @@ static int set_umask (const char *value)
 		return 0;
 	}
 
-	(void) umask ((mode_t) mask);
+	(void) umask (mask);
 	return 0;
 }
 
@@ -508,7 +508,7 @@ void setup_limits (const struct passwd *info)
 				if (   (getlong (cp + 4, &inc) == 1)
 				    && (inc >= -20) && (inc <= 20)) {
 					errno = 0;
-					if (   (nice ((int) inc) != -1)
+					if (   (nice (inc) != -1)
 					    || (0 != errno)) {
 						continue;
 					}
@@ -525,7 +525,7 @@ void setup_limits (const struct passwd *info)
 				long int blocks;
 				if (   (getlong (cp + 7, &blocks) == 0)
 				    || (blocks != (int) blocks)
-				    || (set_filesize_limit ((int) blocks) != 0)) {
+				    || (set_filesize_limit (blocks) != 0)) {
 					SYSLOG ((LOG_WARN,
 					         "Can't set the ulimit for user %s",
 					         info->pw_name));
@@ -540,7 +540,7 @@ void setup_limits (const struct passwd *info)
 					         "Can't set umask value for user %s",
 					         info->pw_name));
 				} else {
-					(void) umask ((mode_t) mask);
+					(void) umask (mask);
 				}
 
 				continue;

libmisc/log.c

@@ -82,7 +82,7 @@ void dolastlog (
 	strncpy (newlog.ll_host, host, sizeof (newlog.ll_host) - 1);
 #endif
 	if (   (lseek (fd, offset, SEEK_SET) != offset)
-	    || (write (fd, (const void *) &newlog, sizeof newlog) != (ssize_t) sizeof newlog)
+	    || (write (fd, &newlog, sizeof newlog) != (ssize_t) sizeof newlog)
 	    || (close (fd) != 0)) {
 		SYSLOG ((LOG_WARN,
 		         "Can't write lastlog entry for UID %lu in %s.",

libmisc/loginprompt.c

@@ -81,7 +81,7 @@ void login_prompt (const char *prompt, char *name, int namesize)
 	 */
 
 	memzero (buf, sizeof buf);
-	if (fgets (buf, (int) sizeof buf, stdin) != buf) {
+	if (fgets (buf, sizeof buf, stdin) != buf) {
 		exit (EXIT_FAILURE);
 	}
 

libmisc/obscure.c

@@ -257,7 +257,7 @@ static /*@observer@*//*@null@*/const char *obscure_msg (
 		}
 
 	}
-	maxlen = (size_t) getdef_num ("PASS_MAX_LEN", 8);
+	maxlen = getdef_num ("PASS_MAX_LEN", 8);
 	if (   (oldlen <= maxlen)
 	    && (newlen <= maxlen)) {
 		return NULL;

libmisc/pam_pass_non_interactive.c

@@ -43,8 +43,7 @@ static int ni_conv (int num_msg,
 		return PAM_CONV_ERR;
 	}
 
-	responses = (struct pam_response *) calloc ((size_t) num_msg,
-	                                            sizeof (*responses));
+	responses = (struct pam_response *) calloc (num_msg, sizeof (*responses));
 	if (NULL == responses) {
 		return PAM_CONV_ERR;
 	}

libmisc/prefix_flag.c

@@ -330,7 +330,7 @@ extern struct group *prefix_getgr_nam_gid(const char *grname)
 	    	&& ('\0' == *endptr)
 	    	&& (ERANGE != errno)
 	    	&& (gid == (gid_t)gid)) {
-			return prefix_getgrgid ((gid_t) gid);
+			return prefix_getgrgid (gid);
 		}
 		g = prefix_getgrnam (grname);
 		return g ? __gr_dup(g) : NULL;

libmisc/pwd2spwd.c

@@ -42,7 +42,7 @@ struct spwd *pwd_to_spwd (const struct passwd *pw)
 		 */
 		sp.sp_min = 0;
 		sp.sp_max = (10000L * DAY) / SCALE;
-		sp.sp_lstchg = (long) gettime () / SCALE;
+		sp.sp_lstchg = gettime () / SCALE;
 		if (0 == sp.sp_lstchg) {
 			/* Better disable aging than requiring a password
 			 * change */

libmisc/salt.c

@@ -377,26 +377,26 @@ static /*@observer@*/const char *gensalt (size_t salt_size)
 	} else if (0 == strcmp (method, "BCRYPT")) {
 		BCRYPTMAGNUM(result);
 		salt_len = BCRYPT_SALT_SIZE;
-		rounds = BCRYPT_get_salt_rounds ((int *) arg);
+		rounds = BCRYPT_get_salt_rounds (arg);
 		BCRYPT_salt_rounds_to_buf (result, rounds);
 #endif /* USE_BCRYPT */
 #ifdef USE_YESCRYPT
 	} else if (0 == strcmp (method, "YESCRYPT")) {
 		MAGNUM(result, 'y');
 		salt_len = YESCRYPT_SALT_SIZE;
-		rounds = YESCRYPT_get_salt_cost ((int *) arg);
+		rounds = YESCRYPT_get_salt_cost (arg);
 		YESCRYPT_salt_cost_to_buf (result, rounds);
 #endif /* USE_YESCRYPT */
 #ifdef USE_SHA_CRYPT
 	} else if (0 == strcmp (method, "SHA256")) {
 		MAGNUM(result, '5');
 		salt_len = SHA_CRYPT_SALT_SIZE;
-		rounds = SHA_get_salt_rounds ((int *) arg);
+		rounds = SHA_get_salt_rounds (arg);
 		SHA_salt_rounds_to_buf (result, rounds);
 	} else if (0 == strcmp (method, "SHA512")) {
 		MAGNUM(result, '6');
 		salt_len = SHA_CRYPT_SALT_SIZE;
-		rounds = SHA_get_salt_rounds ((int *) arg);
+		rounds = SHA_get_salt_rounds (arg);
 		SHA_salt_rounds_to_buf (result, rounds);
 #endif /* USE_SHA_CRYPT */
 	} else if (0 != strcmp (method, "DES")) {

libmisc/ttytype.c

@@ -43,7 +43,7 @@ void ttytype (const char *line)
 		perror (typefile);
 		return;
 	}
-	while (fgets (buf, (int) sizeof buf, fp) == buf) {
+	while (fgets (buf, sizeof buf, fp) == buf) {
 		if (buf[0] == '#') {
 			continue;
 		}

libmisc/tz.c

@@ -34,7 +34,7 @@
 
 	fp = fopen (fname, "r");
 	if (   (NULL == fp)
-	    || (fgets (tzbuf, (int) sizeof (tzbuf), fp) == NULL)) {
+	    || (fgets (tzbuf, sizeof (tzbuf), fp) == NULL)) {
 		def_tz = getdef_str ("ENV_TZ");
 		if ((NULL == def_tz) || ('/' == def_tz[0])) {
 			def_tz = "TZ=CST6CDT";

libmisc/utmp.c

@@ -115,7 +115,7 @@ static void updwtmp (const char *filename, const struct utmp *ut)
 
 	fd = open (filename, O_APPEND | O_WRONLY, 0);
 	if (fd >= 0) {
-		write (fd, (const char *) ut, sizeof (*ut));
+		write (fd, ut, sizeof (*ut));
 		close (fd);
 	}
 }

libmisc/yesno.c

@@ -47,7 +47,7 @@ bool yes_or_no (bool read_only)
 	 * Get a line and see what the first character is.
 	 */
 	/* TODO: use gettext */
-	if (fgets (buf, (int) sizeof buf, stdin) == buf) {
+	if (fgets (buf, sizeof buf, stdin) == buf) {
 		return buf[0] == 'y' || buf[0] == 'Y';
 	}