lib/xref: add xrefs on zlog_* calls

This allows extracting a list of all log messages including their ECs
and autogenerated unique IDs for them.

Signed-off-by: David Lamparter <equinox@diac24.net>

lib/clippy.c

@@ -107,7 +107,8 @@ int main(int argc, char **argv)
 #include "log.h"
 #include "zassert.h"
 
-void vzlog(int prio, const char *format, va_list args)
+void vzlogx(const struct xref_logmsg *xref, int prio,
+	    const char *format, va_list args)
 {
 	vfprintf(stderr, format, args);
 	fputs("\n", stderr);

lib/log.h

@@ -62,16 +62,6 @@ struct message {
 	const char *str;
 };
 
-/* For logs which have error codes associated with them */
-#define flog_err(ferr_id, format, ...)                                        \
-	zlog_err("[EC %u] " format, ferr_id, ##__VA_ARGS__)
-#define flog_err_sys(ferr_id, format, ...)                                     \
-	flog_err(ferr_id, format, ##__VA_ARGS__)
-#define flog_warn(ferr_id, format, ...)                                        \
-	zlog_warn("[EC %u] " format, ferr_id, ##__VA_ARGS__)
-#define flog(priority, ferr_id, format, ...)                                   \
-	zlog(priority, "[EC %u] " format, ferr_id, ##__VA_ARGS__)
-
 extern void zlog_thread_info(int log_level);
 
 #define ZLOG_FILTERS_MAX 100      /* Max # of filters at once */

lib/xref.h

@@ -27,6 +27,8 @@ enum xref_type {
 	XREFT_NONE = 0,
 
 	XREFT_THREADSCHED = 0x100,
+
+	XREFT_LOGMSG = 0x200,
 };
 
 /* struct xref is the "const" part;  struct xrefdata is the writable part. */

lib/zlog.c

@@ -94,6 +94,7 @@ struct zlog_msg {
 
 	const char *fmt;
 	va_list args;
+	const struct xref_logmsg *xref;
 
 	char *stackbuf;
 	size_t stackbufsz;
@@ -349,12 +350,14 @@ void zlog_tls_buffer_flush(void)
 }
 
 
-static void vzlog_notls(int prio, const char *fmt, va_list ap)
+static void vzlog_notls(const struct xref_logmsg *xref, int prio,
+			const char *fmt, va_list ap)
 {
 	struct zlog_target *zt;
 	struct zlog_msg stackmsg = {
 		.prio = prio & LOG_PRIMASK,
 		.fmt = fmt,
+		.xref = xref,
 	}, *msg = &stackmsg;
 	char stackbuf[512];
 
@@ -379,8 +382,8 @@ static void vzlog_notls(int prio, const char *fmt, va_list ap)
 		XFREE(MTYPE_LOG_MESSAGE, msg->text);
 }
 
-static void vzlog_tls(struct zlog_tls *zlog_tls, int prio,
+static void vzlog_tls(struct zlog_tls *zlog_tls, const struct xref_logmsg *xref,
-		      const char *fmt, va_list ap)
+		      int prio, const char *fmt, va_list ap)
 {
 	struct zlog_target *zt;
 	struct zlog_msg *msg;
@@ -413,6 +416,7 @@ static void vzlog_tls(struct zlog_tls *zlog_tls, int prio,
 	msg->stackbufsz = TLS_LOG_BUF_SIZE - zlog_tls->bufpos - 1;
 	msg->fmt = fmt;
 	msg->prio = prio & LOG_PRIMASK;
+	msg->xref = xref;
 	if (msg->prio < LOG_INFO)
 		immediate = true;
 
@@ -447,7 +451,8 @@ static void vzlog_tls(struct zlog_tls *zlog_tls, int prio,
 		XFREE(MTYPE_LOG_MESSAGE, msg->text);
 }
 
-void vzlog(int prio, const char *fmt, va_list ap)
+void vzlogx(const struct xref_logmsg *xref, int prio,
+	    const char *fmt, va_list ap)
 {
 	struct zlog_tls *zlog_tls = zlog_tls_get();
 
@@ -480,9 +485,9 @@ void vzlog(int prio, const char *fmt, va_list ap)
 #endif
 
 	if (zlog_tls)
-		vzlog_tls(zlog_tls, prio, fmt, ap);
+		vzlog_tls(zlog_tls, xref, prio, fmt, ap);
 	else
-		vzlog_notls(prio, fmt, ap);
+		vzlog_notls(xref, prio, fmt, ap);
 }
 
 void zlog_sigsafe(const char *text, size_t len)
@@ -516,6 +521,11 @@ int zlog_msg_prio(struct zlog_msg *msg)
 	return msg->prio;
 }
 
+const struct xref_logmsg *zlog_msg_xref(struct zlog_msg *msg)
+{
+	return msg->xref;
+}
+
 const char *zlog_msg_text(struct zlog_msg *msg, size_t *textlen)
 {
 	if (!msg->text) {

lib/zlog.h

@@ -38,6 +38,20 @@ extern char zlog_prefix[];
 extern size_t zlog_prefixsz;
 extern int zlog_tmpdirfd;
 
+struct xref_logmsg {
+	struct xref xref;
+
+	const char *fmtstring;
+	uint32_t priority;
+	uint32_t ec;
+};
+
+struct xrefdata_logmsg {
+	struct xrefdata xrefdata;
+
+	/* nothing more here right now */
+};
+
 /* These functions are set up to write to stdout/stderr without explicit
  * initialization and/or before config load.  There is no need to call e.g.
  * fprintf(stderr, ...) just because it's "too early" at startup.  Depending
@@ -45,7 +59,9 @@ extern int zlog_tmpdirfd;
  * determine wether something is a log message or something else.
  */
 
-extern void vzlog(int prio, const char *fmt, va_list ap);
+extern void vzlogx(const struct xref_logmsg *xref, int prio,
+		   const char *fmt, va_list ap);
+#define vzlog(prio, ...) vzlogx(NULL, prio, __VA_ARGS__)
 
 PRINTFRR(2, 3)
 static inline void zlog(int prio, const char *fmt, ...)
@@ -57,11 +73,61 @@ static inline void zlog(int prio, const char *fmt, ...)
 	va_end(ap);
 }
 
-#define zlog_err(...)    zlog(LOG_ERR, __VA_ARGS__)
+PRINTFRR(2, 3)
-#define zlog_warn(...)   zlog(LOG_WARNING, __VA_ARGS__)
+static inline void zlog_ref(const struct xref_logmsg *xref,
-#define zlog_info(...)   zlog(LOG_INFO, __VA_ARGS__)
+			    const char *fmt, ...)
-#define zlog_notice(...) zlog(LOG_NOTICE, __VA_ARGS__)
+{
-#define zlog_debug(...)  zlog(LOG_DEBUG, __VA_ARGS__)
+	va_list ap;
+
+	va_start(ap, fmt);
+	vzlogx(xref, xref->priority, fmt, ap);
+	va_end(ap);
+}
+
+#define _zlog_ref(prio, msg, ...) do {                                         \
+		static struct xrefdata _xrefdata = {                           \
+			.hashstr = (msg),                                      \
+			.hashu32 = { (prio), 0 },                              \
+		};                                                             \
+		static const struct xref_logmsg _xref __attribute__((used)) = {\
+			.xref = XREF_INIT(XREFT_LOGMSG, &_xrefdata, __func__), \
+			.fmtstring = (msg),                                    \
+			.priority = (prio),                                    \
+		};                                                             \
+		XREF_LINK(_xref.xref);                                         \
+		zlog_ref(&_xref, (msg), ## __VA_ARGS__);                       \
+	} while (0)
+
+#define zlog_err(...)    _zlog_ref(LOG_ERR, __VA_ARGS__)
+#define zlog_warn(...)   _zlog_ref(LOG_WARNING, __VA_ARGS__)
+#define zlog_info(...)   _zlog_ref(LOG_INFO, __VA_ARGS__)
+#define zlog_notice(...) _zlog_ref(LOG_NOTICE, __VA_ARGS__)
+#define zlog_debug(...)  _zlog_ref(LOG_DEBUG, __VA_ARGS__)
+
+#define _zlog_ecref(ec_, prio, msg, ...) do {                                  \
+		static struct xrefdata _xrefdata = {                           \
+			.hashstr = (msg),                                      \
+			.hashu32 = { (prio), (ec_) },                          \
+		};                                                             \
+		static const struct xref_logmsg _xref __attribute__((used)) = {\
+			.xref = XREF_INIT(XREFT_LOGMSG, &_xrefdata, __func__), \
+			.fmtstring = (msg),                                    \
+			.priority = (prio),                                    \
+			.ec = (ec_),                                           \
+		};                                                             \
+		XREF_LINK(_xref.xref);                                         \
+		zlog_ref(&_xref, "[EC %u] " msg, ec_, ## __VA_ARGS__);         \
+	} while (0)
+
+#define flog_err(ferr_id, format, ...)                                         \
+	_zlog_ecref(ferr_id, LOG_ERR, format, ## __VA_ARGS__)
+#define flog_warn(ferr_id, format, ...)                                        \
+	_zlog_ecref(ferr_id, LOG_WARNING, format, ## __VA_ARGS__)
+
+#define flog_err_sys(ferr_id, format, ...)                                     \
+	flog_err(ferr_id, format, ##__VA_ARGS__)
+#define flog(priority, ferr_id, format, ...)                                   \
+	zlog(priority, "[EC %u] " format, ferr_id, ##__VA_ARGS__)
 
 extern void zlog_sigsafe(const char *text, size_t len);
 
@@ -83,6 +149,7 @@ extern void zlog_sigsafe(const char *text, size_t len);
 struct zlog_msg;
 
 extern int zlog_msg_prio(struct zlog_msg *msg);
+extern const struct xref_logmsg *zlog_msg_xref(struct zlog_msg *msg);
 
 /* pass NULL as textlen if you don't need it. */
 extern const char *zlog_msg_text(struct zlog_msg *msg, size_t *textlen);