[PATCH v1 1/3] lib/vsprintf: Replace hidden BUILD_BUG_ON() with static_assert()

Andy Shevchenko
2020-07-31T12:31:53Z

First of all, there is no compile time check for the SMALL
to be ' ' (0x20, i.e. space). Second, for ZEROPAD the check
is hidden in the code.

For better maintenance replace BUILD_BUG_ON() with static_assert()
for ZEROPAD and move it closer to the definition. While at it,
introduce check for SMALL.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
lib/vsprintf.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 31a674dd2674..8a8ac7ce0289 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -381,6 +381,9 @@ int num_to_str(char *buf, int size, unsigned long long num, unsigned int width)
#define SMALL 32 /* use lowercase in hex (must be 32 == 0x20) */
#define SPECIAL 64 /* prefix hex with "0x", octal with "0" */

+static_assert(ZEROPAD + ' ' == '0');
+static_assert(SMALL == ' ');
+
enum format_type {
FORMAT_TYPE_NONE, /* Just a string part */
FORMAT_TYPE_WIDTH,
@@ -507,7 +510,7 @@ char *number(char *buf, char *end, unsigned long long num,
/* zero or space padding */
if (!(spec.flags & LEFT)) {
char c = ' ' + (spec.flags & ZEROPAD);
- BUILD_BUG_ON(' ' + ZEROPAD != '0');
+
while (--field_width >= 0) {
if (buf < end)
*buf = c;
--
2.27.0