util: make size macros unsigned

poettering · yuwata · commit 67bd5620f6cf · 2020-10-20T15:51:48.000+09:00
By making them unsigned comparing them with other sizes is less likely to trigger compiler warnings regarding signed/unsigned comparisons. After all sizes (i.e. size_t) are generally assumed to be unsigned, so these should be too. Prompted-by: systemd#17345 (comment)
diff --git a/src/basic/format-util.h b/src/basic/format-util.h
@@ -72,11 +72,14 @@ typedef enum {
         FORMAT_BYTES_TRAILING_B  = 1 << 2,
 } FormatBytesFlag;
 
-#define FORMAT_BYTES_MAX 16
+#define FORMAT_BYTES_MAX 16U
+
 char *format_bytes_full(char *buf, size_t l, uint64_t t, FormatBytesFlag flag);
+
 static inline char *format_bytes(char *buf, size_t l, uint64_t t) {
         return format_bytes_full(buf, l, t, FORMAT_BYTES_USE_IEC | FORMAT_BYTES_BELOW_POINT | FORMAT_BYTES_TRAILING_B);
 }
+
 static inline char *format_bytes_cgroup_protection(char *buf, size_t l, uint64_t t) {
         if (t == CGROUP_LIMIT_MAX) {
                 (void) snprintf(buf, l, "%s", "infinity");
diff --git a/src/basic/time-util.h b/src/basic/time-util.h
@@ -63,10 +63,10 @@ typedef enum TimestampStyle {
 
 /* We assume a maximum timezone length of 6. TZNAME_MAX is not defined on Linux, but glibc internally initializes this
  * to 6. Let's rely on that. */
-#define FORMAT_TIMESTAMP_MAX (3+1+10+1+8+1+6+1+6+1)
-#define FORMAT_TIMESTAMP_WIDTH 28 /* when outputting, assume this width */
-#define FORMAT_TIMESTAMP_RELATIVE_MAX 256
-#define FORMAT_TIMESPAN_MAX 64
+#define FORMAT_TIMESTAMP_MAX (3U+1U+10U+1U+8U+1U+6U+1U+6U+1U)
+#define FORMAT_TIMESTAMP_WIDTH 28U /* when outputting, assume this width */
+#define FORMAT_TIMESTAMP_RELATIVE_MAX 256U
+#define FORMAT_TIMESPAN_MAX 64U
 
 #define TIME_T_MAX (time_t)((UINTMAX_C(1) << ((sizeof(time_t) << 3) - 1)) - 1)
 
diff --git a/src/cgtop/cgtop.c b/src/cgtop/cgtop.c
@@ -586,7 +586,7 @@ static void display(Hashmap *a) {
         Group **array;
         signed path_columns;
         unsigned rows, n = 0, j, maxtcpu = 0, maxtpath = 3; /* 3 for ellipsize() to work properly */
-        char buffer[MAX3(21, FORMAT_BYTES_MAX, FORMAT_TIMESPAN_MAX)];
+        char buffer[MAX3(21U, FORMAT_BYTES_MAX, FORMAT_TIMESPAN_MAX)];
 
         assert(a);
 
diff --git a/src/shared/logs-show.c b/src/shared/logs-show.c
@@ -347,7 +347,7 @@ static int output_timestamp_monotonic(FILE *f, sd_journal *j, const char *monoto
 }
 
 static int output_timestamp_realtime(FILE *f, sd_journal *j, OutputMode mode, OutputFlags flags, const char *realtime) {
-        char buf[MAX(FORMAT_TIMESTAMP_MAX, 64)];
+        char buf[MAX(FORMAT_TIMESTAMP_MAX, 64U)];
         struct tm *(*gettime_r)(const time_t *, struct tm *);
         struct tm tm;
         uint64_t x;

Original file line number	Diff line number	Diff line change
`@@ -347,7 +347,7 @@ static int output_timestamp_monotonic(FILE f, sd_journal j, const char *monoto`
`347`	`347`	`}`
`348`	`348`
`349`	`349`	`static int output_timestamp_realtime(FILE f, sd_journal j, OutputMode mode, OutputFlags flags, const char *realtime) {`
`350`		`- char buf[MAX(FORMAT_TIMESTAMP_MAX, 64)];`
	`350`	`+ char buf[MAX(FORMAT_TIMESTAMP_MAX, 64U)];`
`351`	`351`	`struct tm (gettime_r)(const time_t , struct tm );`
`352`	`352`	`struct tm tm;`
`353`	`353`	`uint64_t x;`