Rename (almost) all destructors to destroy_<type>.

We usually did this, but sometimes they were named after what they did,
rather than what they cleaned up.

There are still a few exceptions:
1. I didn't bother creating destroy_xxx wrappers for htable routines
   which already existed.
2. Sometimes destructors really are used for side-effects (eg. to simply
   mark that something was freed): these are clearer with boutique names.
3. Generally destructors are static, but they don't need to be: in some
   cases we attach a destructor then remove it later, or only attach
   to *some* cases.  These are best with qualifiers in the destroy_<type>
   name.

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

common/timeout.c

@@ -8,7 +8,7 @@ struct oneshot {
 	void *arg;
 };
 
-static void remove_timer(struct oneshot *t)
+static void destroy_timer(struct oneshot *t)
 {
 	timer_del(t->timers, &t->timer);
 }
@@ -25,7 +25,7 @@ struct oneshot *new_reltimer_(struct timers *timers,
 	t->timers = timers;
 	timer_init(&t->timer);
 	timer_addrel(timers, &t->timer, relexpiry);
-	tal_add_destructor(t, remove_timer);
+	tal_add_destructor(t, destroy_timer);
 
 	return t;
 }

gossipd/routing.c

@@ -580,8 +580,8 @@ struct routing_channel *routing_channel_new(const tal_t *ctx,
 	return chan;
 }
 
-static void remove_connection_from_channel(struct node_connection *nc,
-					   struct routing_state *rstate)
+static void destroy_node_connection(struct node_connection *nc,
+				    struct routing_state *rstate)
 {
 	struct routing_channel *chan = uintmap_get(
 	    &rstate->channels, short_channel_id_to_uint(&nc->short_channel_id));
@@ -600,7 +600,7 @@ void channel_add_connection(struct routing_state *rstate,
 	int direction = get_channel_direction(&nc->src->id, &nc->dst->id);
 	assert(chan != NULL);
 	chan->connections[direction] = nc;
-	tal_add_destructor2(nc, remove_connection_from_channel, rstate);
+	tal_add_destructor2(nc, destroy_node_connection, rstate);
 }
 
 static void add_pending_node_announcement(struct routing_state *rstate, struct pubkey *nodeid)

lightningd/chaintopology.c

@@ -681,7 +681,7 @@ void chaintopology_mark_pointers_used(struct htable *memtable,
 
 /* On shutdown, channels get deleted last.  That frees from our list, so
  * do it now instead. */
-static void destroy_outgoing_txs(struct chain_topology *topo)
+static void destroy_chain_topology(struct chain_topology *topo)
 {
 	struct outgoing_tx *otx;
 
@@ -724,7 +724,7 @@ void setup_topology(struct chain_topology *topo,
 
 	bitcoind_getblockcount(topo->bitcoind, get_init_blockhash, topo);
 
-	tal_add_destructor(topo, destroy_outgoing_txs);
+	tal_add_destructor(topo, destroy_chain_topology);
 
 	/* Begin fee estimation. */
 	start_fee_estimate(topo);

lightningd/htlc_end.c

@@ -28,14 +28,14 @@ struct htlc_in *find_htlc_in(const struct htlc_in_map *map,
 	return htlc_in_map_get(map, &key);
 }
 
-static void remove_htlc_in(struct htlc_in *hend, struct htlc_in_map *map)
+static void destroy_htlc_in(struct htlc_in *hend, struct htlc_in_map *map)
 {
 	htlc_in_map_del(map, hend);
 }
 
 void connect_htlc_in(struct htlc_in_map *map, struct htlc_in *hend)
 {
-	tal_add_destructor2(hend, remove_htlc_in, map);
+	tal_add_destructor2(hend, destroy_htlc_in, map);
 	htlc_in_map_add(map, hend);
 }
 
@@ -47,14 +47,14 @@ struct htlc_out *find_htlc_out(const struct htlc_out_map *map,
 	return htlc_out_map_get(map, &key);
 }
 
-static void remove_htlc_out(struct htlc_out *hend, struct htlc_out_map *map)
+static void destroy_htlc_out(struct htlc_out *hend, struct htlc_out_map *map)
 {
 	htlc_out_map_del(map, hend);
 }
 
 void connect_htlc_out(struct htlc_out_map *map, struct htlc_out *hend)
 {
-	tal_add_destructor2(hend, remove_htlc_out, map);
+	tal_add_destructor2(hend, destroy_htlc_out, map);
 	htlc_out_map_add(map, hend);
 }
 

lightningd/peer_htlcs.c

@@ -314,7 +314,7 @@ fail:
  *
  * We could queue this and wait for it to come back, but this is simple.
  */
-static void hout_subd_died(struct htlc_out *hout)
+static void destroy_hout_subd_died(struct htlc_out *hout)
 {
 	log_debug(hout->key.channel->log,
 		  "Failing HTLC %"PRIu64" due to peer death",
@@ -355,7 +355,7 @@ static void rcvd_htlc_reply(struct subd *subd, const u8 *msg, const int *fds,
 			local_fail_htlc(hout->in, failure_code,
 					hout->key.channel->scid);
 		/* Prevent hout from being failed twice. */
-		tal_del_destructor(hout, hout_subd_died);
+		tal_del_destructor(hout, destroy_hout_subd_died);
 		tal_free(hout);
 		return;
 	}
@@ -400,7 +400,7 @@ enum onion_type send_htlc_out(struct channel *out, u64 amount, u32 cltv,
 	/* Make peer's daemon own it, catch if it dies. */
 	hout = new_htlc_out(out->owner, out, amount, cltv,
 			    payment_hash, onion_routing_packet, in);
-	tal_add_destructor(hout, hout_subd_died);
+	tal_add_destructor(hout, destroy_hout_subd_died);
 
 	msg = towire_channel_offer_htlc(out, amount, cltv, payment_hash,
 					onion_routing_packet);
@@ -894,7 +894,7 @@ static bool update_out_htlc(struct channel *channel,
 
 	/* First transition into commitment; now it outlives peer. */
 	if (newstate == SENT_ADD_COMMIT) {
-		tal_del_destructor(hout, hout_subd_died);
+		tal_del_destructor(hout, destroy_hout_subd_died);
 		tal_steal(ld, hout);
 
 	} else if (newstate == RCVD_REMOVE_ACK_REVOCATION) {

lightningd/subd.c

@@ -48,7 +48,7 @@ struct subd_req {
 	void *disabler;
 };
 
-static void free_subd_req(struct subd_req *sr)
+static void destroy_subd_req(struct subd_req *sr)
 {
 	list_del(&sr->list);
 	/* Don't disable once we're freed! */
@@ -98,7 +98,7 @@ static void add_req(const tal_t *ctx,
 
 	/* Keep in FIFO order: we sent in order, so replies will be too. */
 	list_add_tail(&sd->reqs, &sr->list);
-	tal_add_destructor(sr, free_subd_req);
+	tal_add_destructor(sr, destroy_subd_req);
 }
 
 /* Caller must free. */

wallet/db.c

@@ -283,7 +283,10 @@ sqlite3_stmt *PRINTF_FMT(3, 4)
 	return stmt;
 }
 
-static void close_db(struct db *db) { sqlite3_close(db->sql); }
+static void destroy_db(struct db *db)
+{
+	sqlite3_close(db->sql);
+}
 
 void db_begin_transaction_(struct db *db, const char *location)
 {
@@ -325,7 +328,7 @@ static struct db *db_open(const tal_t *ctx, char *filename)
 	db = tal(ctx, struct db);
 	db->filename = tal_dup_arr(db, char, filename, strlen(filename), 0);
 	db->sql = sql;
-	tal_add_destructor(db, close_db);
+	tal_add_destructor(db, destroy_db);
 	db->in_transaction = NULL;
 	db_do_exec(__func__, db, "PRAGMA foreign_keys = ON;");
 

wallet/invoices.c

@@ -434,7 +434,7 @@ void invoices_resolve(struct invoices *invoices,
 }
 
 /* Called when an invoice waiter is destructed. */
-static void invoice_waiter_dtor(struct invoice_waiter *w)
+static void destroy_invoice_waiter(struct invoice_waiter *w)
 {
 	/* Already triggered. */
 	if (w->triggered)
@@ -453,7 +453,7 @@ static void add_invoice_waiter(const tal_t *ctx,
 	list_add_tail(waiters, &w->list);
 	w->cb = cb;
 	w->cbarg = cbarg;
-	tal_add_destructor(w, &invoice_waiter_dtor);
+	tal_add_destructor(w, &destroy_invoice_waiter);
 }
 
 

wallet/wallet.c

@@ -1327,7 +1327,7 @@ find_unstored_payment(struct wallet *wallet, const struct sha256 *payment_hash)
 	return NULL;
 }
 
-static void remove_unstored_payment(struct wallet_payment *payment)
+static void destroy_unstored_payment(struct wallet_payment *payment)
 {
 	list_del(&payment->list);
 }
@@ -1337,7 +1337,7 @@ void wallet_payment_setup(struct wallet *wallet, struct wallet_payment *payment)
 	assert(!find_unstored_payment(wallet, &payment->payment_hash));
 
 	list_add_tail(&wallet->unstored_payments, &payment->list);
-	tal_add_destructor(payment, remove_unstored_payment);
+	tal_add_destructor(payment, destroy_unstored_payment);
 }
 
 void wallet_payment_store(struct wallet *wallet,