db: decouple fatal reliance, have as impl defined function

`fatal` is defined in lightningd and has logfile dependencies etc.

Make it more generic by allowing declaration in the use file (wallet.c)

lightningd/log.c

@@ -809,22 +809,25 @@ void log_backtrace_exit(void)
 	}
 }
 
+void fatal_vfmt(const char *fmt, va_list ap)
+{
+	vfprintf(stderr, fmt, ap);
+	fprintf(stderr, "\n");
+
+	if (!crashlog)
+		exit(1);
+
+	logv(crashlog, LOG_BROKEN, NULL, true, fmt, ap);
+	abort();
+}
+
 void fatal(const char *fmt, ...)
 {
 	va_list ap;
 
 	va_start(ap, fmt);
-	vfprintf(stderr, fmt, ap);
+	fatal_vfmt(fmt, ap);
-	fprintf(stderr, "\n");
 	va_end(ap);
-
-	if (!crashlog)
-		exit(1);
-
-	va_start(ap, fmt);
-	logv(crashlog, LOG_BROKEN, NULL, true, fmt, ap);
-	va_end(ap);
-	abort();
 }
 
 struct log_info {

lightningd/log.h

@@ -53,6 +53,7 @@ char *arg_log_to_file(const char *arg, struct lightningd *ld);
 /* Once this is set, we dump fatal with a backtrace to this log */
 extern struct log *crashlog;
 void NORETURN PRINTF_FMT(1,2) fatal(const char *fmt, ...);
+void NORETURN fatal_vfmt(const char *fmt, va_list ap);
 
 void log_backtrace_print(const char *fmt, ...);
 void log_backtrace_exit(void);

wallet/db_common.h

@@ -6,11 +6,6 @@
 #include <ccan/strset/strset.h>
 #include <common/autodata.h>
 
-/* For testing, we want to catch fatal messages. */
-#ifndef db_fatal
-#define db_fatal fatal
-#endif
-
 struct db {
 	char *filename;
 	const char *in_transaction;
@@ -163,6 +158,9 @@ struct db_config {
 /* Provide a way for DB backends to register themselves */
 AUTODATA_TYPE(db_backends, struct db_config);
 
+void db_fatal(const char *fmt, ...)
+	PRINTF_FMT(1, 2);
+
 /**
  * Report a statement that changes the wallet
  *

wallet/test/run-db.c

@@ -1,9 +1,6 @@
 #include "config.h"
   #include <lightningd/log.h>
 
-static void db_test_fatal(const char *fmt, ...);
-#define db_fatal db_test_fatal
-
 static void db_log_(struct log *log UNUSED, enum log_level level UNUSED, const struct node_id *node_id UNUSED, bool call_notifier UNUSED, const char *fmt UNUSED, ...)
 {
 }
@@ -59,7 +56,7 @@ bool wire_sync_write(int fd UNNEEDED, const void *msg TAKES UNNEEDED)
 /* AUTOGENERATED MOCKS END */
 
 static char *db_err;
-static void db_test_fatal(const char *fmt, ...)
+void db_fatal(const char *fmt, ...)
 {
 	va_list ap;
 

wallet/test/run-wallet.c

@@ -1,15 +1,34 @@
 #include "config.h"
   #include <lightningd/log.h>
 
-static void wallet_test_fatal(const char *fmt, ...);
-#define db_fatal wallet_test_fatal
 #include "test_utils.h"
+#include <ccan/tal/str/str.h>
+#include <wallet/db_common.h>
 
 static void db_log_(struct log *log UNUSED, enum log_level level UNUSED, const struct node_id *node_id UNUSED, bool call_notifier UNUSED, const char *fmt UNUSED, ...)
 {
 }
 #define log_ db_log_
 
+#ifndef DB_FATAL
+#define DB_FATAL
+static char *wallet_err;
+void db_fatal(const char *fmt, ...)
+{
+	va_list ap;
+
+	/* Fail hard if we're complaining about not being in transaction */
+	assert(!strstarts(fmt, "No longer in transaction"));
+
+	/* Fail hard if we're complaining about not being in transaction */
+	assert(!strstarts(fmt, "No longer in transaction"));
+
+	va_start(ap, fmt);
+	wallet_err = tal_vfmt(NULL, fmt, ap);
+	va_end(ap);
+}
+#endif /* DB_FATAL */
+
 #include "wallet/wallet.c"
 #include "lightningd/htlc_end.c"
 #include "lightningd/peer_control.c"
@@ -837,22 +856,6 @@ bool fromwire_hsmd_get_channel_basepoints_reply(const void *p UNNEEDED,
 	return true;
 }
 
-static char *wallet_err;
-static void wallet_test_fatal(const char *fmt, ...)
-{
-	va_list ap;
-
-	/* Fail hard if we're complaining about not being in transaction */
-	assert(!strstarts(fmt, "No longer in transaction"));
-
-	/* Fail hard if we're complaining about not being in transaction */
-	assert(!strstarts(fmt, "No longer in transaction"));
-
-	va_start(ap, fmt);
-	wallet_err = tal_vfmt(NULL, fmt, ap);
-	va_end(ap);
-}
-
 #define transaction_wrap(db, ...)					\
 	(db_begin_transaction(db), __VA_ARGS__, db_commit_transaction(db), wallet_err == NULL)
 

wallet/wallet.c

@@ -45,6 +45,21 @@ struct channel_state_param {
 	const enum channel_state_bucket state;
 };
 
+/* Implement db_fatal, as a wrapper around fatal.
+ * We use a ifndef block so that it can get be
+ * implemented in a test file first, if necessary */
+#ifndef DB_FATAL
+#define DB_FATAL
+void db_fatal(const char *fmt, ...)
+{
+	va_list ap;
+
+	va_start(ap, fmt);
+	fatal_vfmt(fmt, ap);
+	va_end(ap);
+}
+#endif /* DB_FATAL */
+
 static void outpointfilters_init(struct wallet *w)
 {
 	struct db_stmt *stmt;