Use a weak logmsg function within libckpool allowing it to be included standalone without touching ckpool code

src/ckpool.c

@@ -30,6 +30,50 @@
 
 ckpool_t *global_ckp;
 
+/* Log everything to the logfile, but display warnings on the console as well */
+void logmsg(int loglevel, const char *fmt, ...) {
+	if (global_ckp->loglevel >= loglevel && fmt) {
+		int logfd = global_ckp->logfd;
+		char *buf = NULL;
+		struct tm *tm;
+		time_t now_t;
+		va_list ap;
+
+		va_start(ap, fmt);
+		VASPRINTF(&buf, fmt, ap);
+		va_end(ap);
+
+		now_t = time(NULL);
+		tm = localtime(&now_t);
+		if (logfd) {
+			FILE *LOGFP = global_ckp->logfp;
+
+			flock(logfd, LOCK_EX);
+			fprintf(LOGFP, "[%d-%02d-%02d %02d:%02d:%02d] %s",
+				tm->tm_year + 1900,
+				tm->tm_mon + 1,
+				tm->tm_mday,
+				tm->tm_hour,
+				tm->tm_min,
+				tm->tm_sec,
+				buf);
+			if (loglevel <= LOG_ERR)
+				fprintf(LOGFP, " with errno %d: %s", errno, strerror(errno));
+			fprintf(LOGFP, "\n");
+			fflush(LOGFP);
+			flock(logfd, LOCK_UN);
+		}
+		if (loglevel <= LOG_WARNING) {\
+			fprintf(stderr, "%s", buf);
+			if (loglevel <= LOG_ERR)
+				fprintf(stderr, " with errno %d: %s", errno, strerror(errno));
+			fprintf(stderr, "\n");
+			fflush(stderr);
+		}
+		free(buf);
+	}
+}
+
 static void *listener(void *arg)
 {
 	proc_instance_t *pi = (proc_instance_t *)arg;

src/ckpool.h

@@ -119,77 +119,4 @@ json_t *json_rpc_call(connsock_t *cs, const char *rpc_req);
 
 int process_exit(ckpool_t *ckp, proc_instance_t *pi, int ret);
 
-#define ASPRINTF(strp, fmt, ...) do { \
-	if (unlikely(asprintf(strp, fmt, ##__VA_ARGS__) < 0)) \
-		quitfrom(1, __FILE__, __func__, __LINE__, "Failed to asprintf"); \
-} while (0)
-
-/* Log everything to the logfile, but display warnings on the console as well */
-#define LOGMSG(_loglevel, fmt, ...) do { \
-	if (global_ckp->loglevel >= _loglevel && fmt) { \
-		struct tm *tm; \
-		char *BUF = NULL; \
-		time_t now_t; \
-		int LOGFD = global_ckp->logfd; \
-		\
-		ASPRINTF(&BUF, fmt, ##__VA_ARGS__); \
-		now_t = time(NULL); \
-		tm = localtime(&now_t); \
-		if (LOGFD) { \
-			FILE *LOGFP = global_ckp->logfp; \
-			\
-			flock(LOGFD, LOCK_EX); \
-			fprintf(LOGFP, "[%d-%02d-%02d %02d:%02d:%02d] %s", \
-				tm->tm_year + 1900, \
-				tm->tm_mon + 1, \
-				tm->tm_mday, \
-				tm->tm_hour, \
-				tm->tm_min, \
-				tm->tm_sec, \
-				BUF); \
-			if (_loglevel <= LOG_ERR) \
-				fprintf(LOGFP, " with errno %d: %s", errno, strerror(errno)); \
-			fprintf(LOGFP, "\n"); \
-			fflush(LOGFP); \
-			flock(LOGFD, LOCK_UN); \
-		} \
-		if (_loglevel <= LOG_WARNING) {\
-			fprintf(stderr, "%s", BUF); \
-			if (_loglevel <= LOG_ERR) \
-				fprintf(stderr, " with errno %d: %s", errno, strerror(errno)); \
-			fprintf(stderr, "\n"); \
-			fflush(stderr); \
-		} \
-		free(BUF); \
-	} \
-} while (0)
-
-#define LOGEMERG(fmt, ...) LOGMSG(LOG_EMERG, fmt, ##__VA_ARGS__)
-#define LOGALERT(fmt, ...) LOGMSG(LOG_ALERT, fmt, ##__VA_ARGS__)
-#define LOGCRIT(fmt, ...) LOGMSG(LOG_CRIT, fmt, ##__VA_ARGS__)
-#define LOGERR(fmt, ...) LOGMSG(LOG_ERR, fmt, ##__VA_ARGS__)
-#define LOGWARNING(fmt, ...) LOGMSG(LOG_WARNING, fmt, ##__VA_ARGS__)
-#define LOGNOTICE(fmt, ...) LOGMSG(LOG_NOTICE, fmt, ##__VA_ARGS__)
-#define LOGINFO(fmt, ...) LOGMSG(LOG_INFO, fmt, ##__VA_ARGS__)
-#define LOGDEBUG(fmt, ...) LOGMSG(LOG_DEBUG, fmt, ##__VA_ARGS__)
-
-#define IN_FMT_FFL " in %s %s():%d"
-#define quitfrom(status, _file, _func, _line, fmt, ...) do { \
-	if (fmt) { \
-		fprintf(stderr, fmt IN_FMT_FFL, ##__VA_ARGS__, _file, _func, _line); \
-		fprintf(stderr, "\n"); \
-		fflush(stderr); \
-	} \
-	exit(status); \
-} while (0)
-
-#define quit(status, fmt, ...) do { \
-	if (fmt) { \
-		fprintf(stderr, fmt, ##__VA_ARGS__); \
-		fprintf(stderr, "\n"); \
-		fflush(stderr); \
-	} \
-	exit(status); \
-} while (0)
-
 #endif /* CKPOOL_H */

src/libckpool.c

@@ -37,6 +37,21 @@
 #define UNIX_PATH_MAX 108
 #endif
 
+/* We use a weak function as a simple printf within the library that can be
+ * overridden by however the outside executable wishes to do its logging. */
+void __attribute__((weak)) logmsg(int __maybe_unused loglevel, const char *fmt, ...)
+{
+	va_list ap;
+	char *buf;
+
+	va_start(ap, fmt);
+	VASPRINTF(&buf, fmt, ap);
+	va_end(ap);
+
+	printf("%s\n", buf);
+	free(buf);
+}
+
 void rename_proc(const char *name)
 {
 	char buf[16];

src/libckpool.h

@@ -161,18 +161,45 @@ static inline void flip_80(void *dest_p, const void *src_p)
 
 #define dealloc(ptr) _dealloc((void *)&(ptr))
 
-/* Should be defined in syslog, but keeping them here is a reminder of their
- * values. */
-#ifndef LOG_ERR
-#define	LOG_EMERG	0	/* system is unusable */
-#define	LOG_ALERT	1	/* action must be taken immediately */
-#define	LOG_CRIT	2	/* critical conditions */
-#define	LOG_ERR		3	/* error conditions */
-#define	LOG_WARNING	4	/* warning conditions */
-#define	LOG_NOTICE	5	/* normal but significant condition */
-#define	LOG_INFO	6	/* informational */
-#define	LOG_DEBUG	7	/* debug-level messages */
-#endif
+#define VASPRINTF(strp, fmt, ...) do { \
+	if (unlikely(vasprintf(strp, fmt, ##__VA_ARGS__) < 0)) \
+		quitfrom(1, __FILE__, __func__, __LINE__, "Failed to asprintf"); \
+} while (0)
+
+#define ASPRINTF(strp, fmt, ...) do { \
+	if (unlikely(asprintf(strp, fmt, ##__VA_ARGS__) < 0)) \
+		quitfrom(1, __FILE__, __func__, __LINE__, "Failed to asprintf"); \
+} while (0)
+
+void logmsg(int loglevel, const char *fmt, ...);
+
+#define LOGEMERG(fmt, ...) logmsg(LOG_EMERG, fmt, ##__VA_ARGS__)
+#define LOGALERT(fmt, ...) logmsg(LOG_ALERT, fmt, ##__VA_ARGS__)
+#define LOGCRIT(fmt, ...) logmsg(LOG_CRIT, fmt, ##__VA_ARGS__)
+#define LOGERR(fmt, ...) logmsg(LOG_ERR, fmt, ##__VA_ARGS__)
+#define LOGWARNING(fmt, ...) logmsg(LOG_WARNING, fmt, ##__VA_ARGS__)
+#define LOGNOTICE(fmt, ...) logmsg(LOG_NOTICE, fmt, ##__VA_ARGS__)
+#define LOGINFO(fmt, ...) logmsg(LOG_INFO, fmt, ##__VA_ARGS__)
+#define LOGDEBUG(fmt, ...) logmsg(LOG_DEBUG, fmt, ##__VA_ARGS__)
+
+#define IN_FMT_FFL " in %s %s():%d"
+#define quitfrom(status, _file, _func, _line, fmt, ...) do { \
+	if (fmt) { \
+		fprintf(stderr, fmt IN_FMT_FFL, ##__VA_ARGS__, _file, _func, _line); \
+		fprintf(stderr, "\n"); \
+		fflush(stderr); \
+	} \
+	exit(status); \
+} while (0)
+
+#define quit(status, fmt, ...) do { \
+	if (fmt) { \
+		fprintf(stderr, fmt, ##__VA_ARGS__); \
+		fprintf(stderr, "\n"); \
+		fflush(stderr); \
+	} \
+	exit(status); \
+} while (0)
 
 #define PAGESIZE (4096)