lightningd: fix backtraces in memleak detection.

We were using a *different* backtrace_state var, which was always NULL.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

common/daemon.c

@@ -15,8 +15,9 @@
 #include <unistd.h>
 #include <wally_core.h>
 
+struct backtrace_state *backtrace_state;
+
 #if BACKTRACE_SUPPORTED
-static struct backtrace_state *backtrace_state;
 static void (*bt_print)(const char *fmt, ...) PRINTF_FMT(1,2);
 static void (*bt_exit)(void);
 

common/daemon.h

@@ -10,4 +10,6 @@ void daemon_setup(const char *argv0,
 /* Shutdown for a valgrind-clean exit (frees everything) */
 void daemon_shutdown(void);
 
+struct backtrace_state *backtrace_state;
+
 #endif /* LIGHTNING_COMMON_DAEMON_H */

common/memleak.c

@@ -2,10 +2,10 @@
 #include <backtrace.h>
 #include <ccan/crypto/siphash24/siphash24.h>
 #include <ccan/htable/htable.h>
+#include <common/daemon.h>
 #include <common/memleak.h>
 
 #if DEVELOPER
-static struct backtrace_state *backtrace_state;
 static const void **notleaks;
 static bool *notleak_children;
 
@@ -226,10 +226,9 @@ static void add_backtrace(tal_t *parent UNUSED, enum tal_notify_type type UNNEED
 	tal_add_notifier(child, TAL_NOTIFY_ADD_CHILD, add_backtrace);
 }
 
-void memleak_init(const tal_t *root, struct backtrace_state *bstate)
+void memleak_init(const tal_t *root)
 {
 	assert(!notleaks);
-	backtrace_state = bstate;
 	notleaks = tal_arr(NULL, const void *, 0);
 	notleak_children = tal_arr(notleaks, bool, 0);
 

common/memleak.h

@@ -21,10 +21,9 @@
 void *notleak_(const void *ptr, bool plus_children);
 
 struct htable;
-struct backtrace_state;
 
 /* Initialize memleak detection, with this as the root */
-void memleak_init(const tal_t *root, struct backtrace_state *bstate);
+void memleak_init(const tal_t *root);
 
 /* Free memleak detection. */
 void memleak_cleanup(void);

lightningd/lightningd.c

@@ -41,8 +41,6 @@
 
 char *bitcoin_datadir;
 
-struct backtrace_state *backtrace_state;
-
 int pid_fd;
 
 static struct lightningd *new_lightningd(const tal_t *ctx)
@@ -56,7 +54,7 @@ static struct lightningd *new_lightningd(const tal_t *ctx)
 	ld->dev_allow_localhost = false;
 
 	if (getenv("LIGHTNINGD_DEV_MEMLEAK"))
-		memleak_init(ld, backtrace_state);
+		memleak_init(ld);
 #endif
 
 	list_head_init(&ld->peers);

lightningd/lightningd.h

@@ -204,9 +204,6 @@ struct lightningd {
 
 const struct chainparams *get_chainparams(const struct lightningd *ld);
 
-/* State for performing backtraces. */
-struct backtrace_state *backtrace_state;
-
 /* Check we can run subdaemons, and check their versions */
 void test_daemons(const struct lightningd *ld);
 

lightningd/memdump.c

@@ -3,6 +3,7 @@
 #if DEVELOPER
 #include <backtrace.h>
 #include <ccan/tal/str/str.h>
+#include <common/daemon.h>
 #include <common/memleak.h>
 #include <lightningd/chaintopology.h>
 #include <lightningd/jsonrpc.h>