Add new __BARE_METAL__ target flag

This flag should be defined when c-utils is built for bare metal
(embedded) targets. This change is not exhaustive; more code needs to be
moved into this section as and when discovered.

The idea was suggested in #28; this commit is just small variation to
the proposed change there.

Signed-off-by: Siddharth Chandrasekaran <[email protected]>

src/logger.c

@@ -59,17 +59,18 @@ static const char *log_level_names[LOG_MAX_LEVEL] = {
 
 static inline void logger_log_set_color(logger_t *ctx, const char *color)
 {
+#if !defined(__BARE_METAL__)
 	size_t ret, len;
 
 	if (ctx->flags & LOGGER_FLAG_NO_COLORS)
 		return;
-
 	if (ctx->file && isatty(fileno(ctx->file))) {
 		len = strnlen(color, 8);
 		ret = write(fileno(ctx->file), color, len);
 		assert(ret == len);
 		ARG_UNUSED(ret); /* squash warning in Release builds */
 	}
+#endif
 }
 
 static const char *get_tstamp()

src/utils.c

@@ -148,6 +148,29 @@ int add_iso8601_utc_datetime(char *buf, size_t size)
 	return strftime(buf, size, "%Y-%m-%dT%H:%M:%SZ", &timeinfo);
 }
 
+#elif defined(__BARE_METAL__)
+
+struct timeval {
+	long tv_sec;  // seconds since epoch
+	long tv_usec; // microseconds
+};
+
+struct timezone {
+	int tz_minuteswest; // minutes west of UTC
+	int tz_dsttime;     // daylight saving time flag
+};
+
+int gettimeofday(struct timeval * tp, struct timezone * tzp)
+{
+	tp->tv_sec = 0;
+	tp->tv_usec = 0;
+	return 0;
+}
+
+int add_iso8601_utc_datetime(char* buf, size_t size) {
+	return 0;
+}
+
 #else
 
 #error Platform test failed