top(1): cleanup memory allocation and warnings

- Prefer calloc over malloc. This is more predicable and we're not in a
performance sensitive context. [1]
- Remove bogus comment (obsolete from prior commit). [2]
- Remove void casts and type casts of NULL
- Remove redundant declaration of 'quit'
- Add additional const

Reported by:	kib [1], vangyzen [2]

usr.bin/top/display.c

@@ -148,8 +148,8 @@ display_resize(void)
     }
 
     /* now, allocate space for the screen buffer */
-    screenbuf = malloc(lines * display_width);
-    if (screenbuf == (char *)NULL)
+    screenbuf = calloc(lines, display_width);
+    if (screenbuf == NULL)
     {
 	/* oops! */
 	return(-1);
@@ -205,23 +205,23 @@ int display_init(struct statics * statics)
 	procstate_names = statics->procstate_names;
 	num_procstates = string_count(procstate_names);
 	assert(num_procstates > 0);
-	lprocstates = malloc(num_procstates * sizeof(int));
+	lprocstates = calloc(num_procstates, sizeof(int));
 
 	cpustate_names = statics->cpustate_names;
 
 	swap_names = statics->swap_names;
 	num_swap = string_count(swap_names);
 	assert(num_swap > 0);
-	lswap = malloc(num_swap * sizeof(int));
+	lswap = calloc(num_swap, sizeof(int));
 	num_cpustates = string_count(cpustate_names);
 	assert(num_cpustates > 0);
-	lcpustates = malloc(num_cpustates * sizeof(int) * statics->ncpus);
-	cpustate_columns = malloc(num_cpustates * sizeof(int));
+	lcpustates = calloc(num_cpustates * sizeof(int), statics->ncpus);
+	cpustate_columns = calloc(num_cpustates, sizeof(int));
 
 	memory_names = statics->memory_names;
 	num_memory = string_count(memory_names);
 	assert(num_memory > 0);
-	lmemory = malloc(num_memory * sizeof(int));
+	lmemory = calloc(num_memory, sizeof(int));
 
 	arc_names = statics->arc_names;
 	carc_names = statics->carc_names;
@@ -745,7 +745,7 @@ trim_header(char *text)
 	width = display_width;
 	header_length = strlen(text);
 	if (header_length >= width) {
-		s = malloc((width + 1) * sizeof(char));
+		s = calloc((width + 1), sizeof(char));
 		if (s == NULL)
 			return (NULL);
 		strncpy(s, text, width);

usr.bin/top/machine.c

@@ -382,9 +382,9 @@ machine_init(struct statics *statics)
 	ncpus = 0;
 	GETSYSCTL("kern.smp.maxcpus", maxcpu);
 	size = sizeof(long) * maxcpu * CPUSTATES;
-	times = malloc(size);
+	times = calloc(size, 1);
 	if (times == NULL)
-		err(1, "malloc %zu bytes", size);
+		err(1, "calloc %zu bytes", size);
 	if (sysctlbyname("kern.cp_times", times, &size, NULL, 0) == -1)
 		err(1, "sysctlbyname kern.cp_times");
 	pcpu_cp_time = calloc(1, size);
@@ -779,11 +779,11 @@ get_process_info(struct system_info *si, struct process_select *sel,
 	 */
 	if (previous_proc_count_max < nproc) {
 		free(previous_procs);
-		previous_procs = malloc(nproc * sizeof(*previous_procs));
+		previous_procs = calloc(nproc, sizeof(*previous_procs));
 		free(previous_pref);
-		previous_pref = malloc(nproc * sizeof(*previous_pref));
+		previous_pref = calloc(nproc, sizeof(*previous_pref));
 		if (previous_procs == NULL || previous_pref == NULL) {
-			(void) fprintf(stderr, "top: Out of memory.\n");
+			fprintf(stderr, "top: Out of memory.\n");
 			quit(TOP_EX_SYS_ERROR);
 		}
 		previous_proc_count_max = nproc;
@@ -996,9 +996,9 @@ format_next_process(caddr_t xhandle, char *(*get_userid)(uid_t), int flags)
 		break;
 	}
 
-	cmdbuf = malloc(cmdlen + 1);
+	cmdbuf = calloc(cmdlen + 1, 1);
 	if (cmdbuf == NULL) {
-		warn("malloc(%d)", cmdlen + 1);
+		warn("calloc(%d)", cmdlen + 1);
 		return NULL;
 	}
 
@@ -1031,9 +1031,9 @@ format_next_process(caddr_t xhandle, char *(*get_userid)(uid_t), int flags)
 			size_t len;
 
 			argbuflen = cmdlen * 4;
-			argbuf = malloc(argbuflen + 1);
+			argbuf = calloc(argbuflen + 1, 1);
 			if (argbuf == NULL) {
-				warn("malloc(%zu)", argbuflen + 1);
+				warn("calloc(%zu)", argbuflen + 1);
 				free(cmdbuf);
 				return NULL;
 			}

usr.bin/top/screen.c

@@ -3,7 +3,7 @@
  *  Version 3
  *
  *  This program may be freely redistributed,
- *  but this entire comment MUST remain intact.
+ *  but this entire ceomment MUST remain intact.
  *
  *  Copyright (c) 1984, 1989, William LeFebvre, Rice University
  *  Copyright (c) 1989, 1990, 1992, William LeFebvre, Northwestern University
@@ -270,7 +270,7 @@ get_screensize(void)
 }
 
 void
-top_standout(char *msg)
+top_standout(const char *msg)
 {
     if (smart_terminal)
     {

usr.bin/top/screen.h

@@ -25,9 +25,8 @@ extern char *clear_to_end;
 extern int  screen_length;
 extern int  screen_width;
 
-/* a function that puts a single character on stdout */
 int		clear_eol(int len);
-void	top_standout(char *msg);
+void	top_standout(const char *msg);
 void	top_clear(void);
 void	go_home(void);
 void	reinit_screen(void);

usr.bin/top/utils.c

@@ -26,8 +26,6 @@
 #include <paths.h>
 #include <kvm.h>
 
-void quit(int);
-
 int
 atoiwi(const char *str)
 {
@@ -201,10 +199,10 @@ argparse(char *line, int *cntp)
     cnt += 3;
 
     /* allocate a char * array to hold the pointers */
-    argarray = malloc(cnt * sizeof(char *));
+    argarray = calloc(cnt, sizeof(char *));
 
     /* allocate another array to hold the strings themselves */
-    args = malloc(length+2);
+    args = calloc(length+2, 1);
 
     /* initialization for main loop */
     from = line;