lightningd: add code to search strmaps for memleak detection.

Didn't put this in common/memleak because only lightningd currently needs it
(as of next patch).

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

Makefile

@@ -96,6 +96,7 @@ CCAN_OBJS :=					\
 	ccan-str-base32.o			\
 	ccan-str-hex.o				\
 	ccan-str.o				\
+	ccan-strmap.o				\
 	ccan-take.o				\
 	ccan-tal-grab_file.o			\
 	ccan-tal-link.o				\

lightningd/memdump.c

@@ -2,6 +2,7 @@
 #include "memdump.h"
 #if DEVELOPER
 #include <backtrace.h>
+#include <ccan/strmap/strmap.h>
 #include <ccan/tal/str/str.h>
 #include <common/daemon.h>
 #include <common/json_command.h>
@@ -120,6 +121,22 @@ static void json_add_backtrace(struct json_stream *response,
 	json_array_end(response);
 }
 
+static bool handle_strmap(const char *member, void *p, void *memtable_)
+{
+	struct htable *memtable = memtable_;
+
+	memleak_scan_region(memtable, p, tal_bytelen(p));
+
+	/* Keep going */
+	return true;
+}
+
+/* FIXME: If strmap used tal, this wouldn't be necessary! */
+void memleak_remove_strmap_(struct htable *memtable, const struct strmap *m)
+{
+	strmap_iterate_(m, handle_strmap, memtable);
+}
+
 static void scan_mem(struct command *cmd,
 		     struct json_stream *response,
 		     struct lightningd *ld,

lightningd/memdump.h

@@ -5,8 +5,16 @@
 #include <stdbool.h>
 
 struct command;
+struct htable;
+struct strmap;
 struct subd;
 
 void opening_memleak_done(struct command *cmd, struct subd *leaker);
 void peer_memleak_done(struct command *cmd, struct subd *leaker);
+
+/* Remove any pointers inside this strmap (which is opaque to memleak). */
+#define memleak_remove_strmap(memtable, strmap) \
+	memleak_remove_strmap_((memtable), tcon_unwrap(strmap))
+void memleak_remove_strmap_(struct htable *memtable, const struct strmap *m);
+
 #endif /* LIGHTNING_LIGHTNINGD_MEMDUMP_H */