wire: make fromwire_fail return non-const, use it more

It returns NULL, so you can simply `return fromwire_fail(...)`
if you want to return NULL in this case.  Use that more.

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

bitcoin/test/run-bitcoin_block_from_hex.c

@@ -30,7 +30,7 @@ bool amount_sat_eq(struct amount_sat a UNNEEDED, struct amount_sat b UNNEEDED)
 struct amount_sat fromwire_amount_sat(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 { fprintf(stderr, "fromwire_amount_sat called!\n"); abort(); }
 /* Generated stub for fromwire_fail */
-const void *fromwire_fail(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
+void *fromwire_fail(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 { fprintf(stderr, "fromwire_fail called!\n"); abort(); }
 /* Generated stub for fromwire_sha256 */
 void fromwire_sha256(const u8 **cursor UNNEEDED, size_t *max UNNEEDED, struct sha256 *sha256 UNNEEDED)

bitcoin/test/run-tx-encode.c

@@ -31,7 +31,7 @@ bool amount_sat_eq(struct amount_sat a UNNEEDED, struct amount_sat b UNNEEDED)
 struct amount_sat fromwire_amount_sat(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 { fprintf(stderr, "fromwire_amount_sat called!\n"); abort(); }
 /* Generated stub for fromwire_fail */
-const void *fromwire_fail(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
+void *fromwire_fail(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 { fprintf(stderr, "fromwire_fail called!\n"); abort(); }
 /* Generated stub for fromwire_sha256 */
 void fromwire_sha256(const u8 **cursor UNNEEDED, size_t *max UNNEEDED, struct sha256 *sha256 UNNEEDED)

common/test/run-amount.c

@@ -11,7 +11,7 @@ const u8 *fromwire(const u8 **cursor UNNEEDED, size_t *max UNNEEDED, void *copy
 bool fromwire_bool(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 { fprintf(stderr, "fromwire_bool called!\n"); abort(); }
 /* Generated stub for fromwire_fail */
-const void *fromwire_fail(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
+void *fromwire_fail(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 { fprintf(stderr, "fromwire_fail called!\n"); abort(); }
 /* Generated stub for fromwire_secp256k1_ecdsa_signature */
 void fromwire_secp256k1_ecdsa_signature(const u8 **cursor UNNEEDED, size_t *max UNNEEDED,

common/test/run-bigsize.c

@@ -42,7 +42,7 @@ struct amount_sat fromwire_amount_sat(const u8 **cursor UNNEEDED, size_t *max UN
 bool fromwire_bool(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 { fprintf(stderr, "fromwire_bool called!\n"); abort(); }
 /* Generated stub for fromwire_fail */
-const void *fromwire_fail(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
+void *fromwire_fail(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 { fprintf(stderr, "fromwire_fail called!\n"); abort(); }
 /* Generated stub for fromwire_secp256k1_ecdsa_signature */
 void fromwire_secp256k1_ecdsa_signature(const u8 **cursor UNNEEDED, size_t *max UNNEEDED,

common/test/run-cryptomsg.c

@@ -37,7 +37,7 @@ struct amount_sat fromwire_amount_sat(const u8 **cursor UNNEEDED, size_t *max UN
 bool fromwire_bool(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 { fprintf(stderr, "fromwire_bool called!\n"); abort(); }
 /* Generated stub for fromwire_fail */
-const void *fromwire_fail(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
+void *fromwire_fail(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 { fprintf(stderr, "fromwire_fail called!\n"); abort(); }
 /* Generated stub for fromwire_secp256k1_ecdsa_signature */
 void fromwire_secp256k1_ecdsa_signature(const u8 **cursor UNNEEDED, size_t *max UNNEEDED,

common/test/run-derive_basepoints.c

@@ -38,7 +38,7 @@ struct amount_sat fromwire_amount_sat(const u8 **cursor UNNEEDED, size_t *max UN
 bool fromwire_bool(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 { fprintf(stderr, "fromwire_bool called!\n"); abort(); }
 /* Generated stub for fromwire_fail */
-const void *fromwire_fail(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
+void *fromwire_fail(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 { fprintf(stderr, "fromwire_fail called!\n"); abort(); }
 /* Generated stub for fromwire_secp256k1_ecdsa_signature */
 void fromwire_secp256k1_ecdsa_signature(const u8 **cursor UNNEEDED, size_t *max UNNEEDED,

common/test/run-features.c

@@ -37,7 +37,7 @@ struct amount_sat fromwire_amount_sat(const u8 **cursor UNNEEDED, size_t *max UN
 bool fromwire_bool(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 { fprintf(stderr, "fromwire_bool called!\n"); abort(); }
 /* Generated stub for fromwire_fail */
-const void *fromwire_fail(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
+void *fromwire_fail(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 { fprintf(stderr, "fromwire_fail called!\n"); abort(); }
 /* Generated stub for fromwire_secp256k1_ecdsa_signature */
 void fromwire_secp256k1_ecdsa_signature(const u8 **cursor UNNEEDED, size_t *max UNNEEDED,

common/test/run-funding_tx.c

@@ -26,7 +26,7 @@ const u8 *fromwire(const u8 **cursor UNNEEDED, size_t *max UNNEEDED, void *copy
 bool fromwire_bool(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 { fprintf(stderr, "fromwire_bool called!\n"); abort(); }
 /* Generated stub for fromwire_fail */
-const void *fromwire_fail(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
+void *fromwire_fail(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 { fprintf(stderr, "fromwire_fail called!\n"); abort(); }
 /* Generated stub for fromwire_node_id */
 void fromwire_node_id(const u8 **cursor UNNEEDED, size_t *max UNNEEDED, struct node_id *id UNNEEDED)

common/test/run-ip_port_parsing.c

@@ -36,7 +36,7 @@ struct amount_sat fromwire_amount_sat(const u8 **cursor UNNEEDED, size_t *max UN
 bool fromwire_bool(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 { fprintf(stderr, "fromwire_bool called!\n"); abort(); }
 /* Generated stub for fromwire_fail */
-const void *fromwire_fail(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
+void *fromwire_fail(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 { fprintf(stderr, "fromwire_fail called!\n"); abort(); }
 /* Generated stub for fromwire_secp256k1_ecdsa_signature */
 void fromwire_secp256k1_ecdsa_signature(const u8 **cursor UNNEEDED, size_t *max UNNEEDED,

common/test/run-json_remove.c

@@ -34,7 +34,7 @@ struct amount_sat fromwire_amount_sat(const u8 **cursor UNNEEDED, size_t *max UN
 bool fromwire_bool(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 { fprintf(stderr, "fromwire_bool called!\n"); abort(); }
 /* Generated stub for fromwire_fail */
-const void *fromwire_fail(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
+void *fromwire_fail(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 { fprintf(stderr, "fromwire_fail called!\n"); abort(); }
 /* Generated stub for fromwire_secp256k1_ecdsa_signature */
 void fromwire_secp256k1_ecdsa_signature(const u8 **cursor UNNEEDED, size_t *max UNNEEDED,

common/test/run-key_derive.c

@@ -39,7 +39,7 @@ struct amount_sat fromwire_amount_sat(const u8 **cursor UNNEEDED, size_t *max UN
 bool fromwire_bool(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 { fprintf(stderr, "fromwire_bool called!\n"); abort(); }
 /* Generated stub for fromwire_fail */
-const void *fromwire_fail(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
+void *fromwire_fail(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 { fprintf(stderr, "fromwire_fail called!\n"); abort(); }
 /* Generated stub for fromwire_secp256k1_ecdsa_signature */
 void fromwire_secp256k1_ecdsa_signature(const u8 **cursor UNNEEDED, size_t *max UNNEEDED,

common/test/run-lock.c

@@ -38,7 +38,7 @@ struct amount_sat fromwire_amount_sat(const u8 **cursor UNNEEDED, size_t *max UN
 bool fromwire_bool(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 { fprintf(stderr, "fromwire_bool called!\n"); abort(); }
 /* Generated stub for fromwire_fail */
-const void *fromwire_fail(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
+void *fromwire_fail(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 { fprintf(stderr, "fromwire_fail called!\n"); abort(); }
 /* Generated stub for fromwire_secp256k1_ecdsa_signature */
 void fromwire_secp256k1_ecdsa_signature(const u8 **cursor UNNEEDED, size_t *max UNNEEDED,

common/test/run-softref.c

@@ -35,7 +35,7 @@ struct amount_sat fromwire_amount_sat(const u8 **cursor UNNEEDED, size_t *max UN
 bool fromwire_bool(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 { fprintf(stderr, "fromwire_bool called!\n"); abort(); }
 /* Generated stub for fromwire_fail */
-const void *fromwire_fail(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
+void *fromwire_fail(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 { fprintf(stderr, "fromwire_fail called!\n"); abort(); }
 /* Generated stub for fromwire_secp256k1_ecdsa_signature */
 void fromwire_secp256k1_ecdsa_signature(const u8 **cursor UNNEEDED, size_t *max UNNEEDED,

connectd/test/run-initiator-success.c

@@ -41,7 +41,7 @@ struct amount_sat fromwire_amount_sat(const u8 **cursor UNNEEDED, size_t *max UN
 bool fromwire_bool(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 { fprintf(stderr, "fromwire_bool called!\n"); abort(); }
 /* Generated stub for fromwire_fail */
-const void *fromwire_fail(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
+void *fromwire_fail(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 { fprintf(stderr, "fromwire_fail called!\n"); abort(); }
 /* Generated stub for fromwire_secp256k1_ecdsa_signature */
 void fromwire_secp256k1_ecdsa_signature(const u8 **cursor UNNEEDED, size_t *max UNNEEDED,

connectd/test/run-responder-success.c

@@ -41,7 +41,7 @@ struct amount_sat fromwire_amount_sat(const u8 **cursor UNNEEDED, size_t *max UN
 bool fromwire_bool(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 { fprintf(stderr, "fromwire_bool called!\n"); abort(); }
 /* Generated stub for fromwire_fail */
-const void *fromwire_fail(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
+void *fromwire_fail(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 { fprintf(stderr, "fromwire_fail called!\n"); abort(); }
 /* Generated stub for fromwire_secp256k1_ecdsa_signature */
 void fromwire_secp256k1_ecdsa_signature(const u8 **cursor UNNEEDED, size_t *max UNNEEDED,

lightningd/gossip_msg.c

@@ -28,10 +28,8 @@ struct gossip_getnodes_entry *fromwire_gossip_getnodes_entry(const tal_t *ctx,
 	entry->addresses = tal_arr(entry, struct wireaddr, numaddresses);
 	for (i=0; i<numaddresses; i++) {
 		/* Gossipd doesn't hand us addresses we can't understand. */
-		if (!fromwire_wireaddr(pptr, max, &entry->addresses[i])) {
+		if (!fromwire_wireaddr(pptr, max, &entry->addresses[i]))
-			fromwire_fail(pptr, max);
+			return fromwire_fail(pptr, max);
-			return NULL;
-		}
 	}
 	fromwire(pptr, max, entry->alias, ARRAY_SIZE(entry->alias));
 	fromwire(pptr, max, entry->color, ARRAY_SIZE(entry->color));
@@ -210,8 +208,7 @@ struct exclude_entry *fromwire_exclude_entry(const tal_t *ctx,
 			fromwire_node_id(pptr, max, &entry->u.node_id);
 			return entry;
 		default:
-			fromwire_fail(pptr, max);
+			return fromwire_fail(pptr, max);
-			return NULL;
 	}
 }
 

onchaind/test/run-grind_feerate-bug.c

@@ -35,7 +35,7 @@ const u8 *fromwire(const u8 **cursor UNNEEDED, size_t *max UNNEEDED, void *copy
 bool fromwire_bool(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 { fprintf(stderr, "fromwire_bool called!\n"); abort(); }
 /* Generated stub for fromwire_fail */
-const void *fromwire_fail(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
+void *fromwire_fail(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 { fprintf(stderr, "fromwire_fail called!\n"); abort(); }
 /* Generated stub for fromwire_hsm_get_per_commitment_point_reply */
 bool fromwire_hsm_get_per_commitment_point_reply(const tal_t *ctx UNNEEDED, const void *p UNNEEDED, struct pubkey *per_commitment_point UNNEEDED, struct secret **old_commitment_secret UNNEEDED)

onchaind/test/run-grind_feerate.c

@@ -36,7 +36,7 @@ const u8 *fromwire(const u8 **cursor UNNEEDED, size_t *max UNNEEDED, void *copy
 bool fromwire_bool(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 { fprintf(stderr, "fromwire_bool called!\n"); abort(); }
 /* Generated stub for fromwire_fail */
-const void *fromwire_fail(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
+void *fromwire_fail(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 { fprintf(stderr, "fromwire_fail called!\n"); abort(); }
 /* Generated stub for fromwire_hsm_get_per_commitment_point_reply */
 bool fromwire_hsm_get_per_commitment_point_reply(const tal_t *ctx UNNEEDED, const void *p UNNEEDED, struct pubkey *per_commitment_point UNNEEDED, struct secret **old_commitment_secret UNNEEDED)

wire/fromwire.c

@@ -16,7 +16,7 @@
 extern const struct chainparams *chainparams;
 
 /* Sets *cursor to NULL and returns NULL when extraction fails. */
-const void *fromwire_fail(const u8 **cursor, size_t *max)
+void *fromwire_fail(const u8 **cursor, size_t *max)
 {
 	*cursor = NULL;
 	*max = 0;
@@ -211,10 +211,9 @@ u8 *fromwire_tal_arrn(const tal_t *ctx,
 		      const u8 **cursor, size_t *max, size_t num)
 {
 	u8 *arr;
-	if (num > *max) {
+	if (num > *max)
-		fromwire_fail(cursor, max);
+		return fromwire_fail(cursor, max);
-		return NULL;
+
-	}
 	arr = tal_arr(ctx, u8, num);
 	fromwire_u8_array(cursor, max, arr, num);
 	return arr;
@@ -242,8 +241,7 @@ char *fromwire_wirestring(const tal_t *ctx, const u8 **cursor, size_t *max)
 		if ((*cursor)[i] < ' ')
 			break;
 	}
-	fromwire_fail(cursor, max);
+	return fromwire_fail(cursor, max);
-	return NULL;
 }
 
 void fromwire_siphash_seed(const u8 **cursor, size_t *max,

wire/wire.h

@@ -16,7 +16,7 @@ typedef char wirestring;
 
 /* Read the type; returns -1 if not long enough.  cursor is a tal ptr. */
 int fromwire_peektype(const u8 *cursor);
-const void *fromwire_fail(const u8 **cursor, size_t *max);
+void *fromwire_fail(const u8 **cursor, size_t *max);
 
 void towire(u8 **pptr, const void *data, size_t len);
 void towire_secp256k1_ecdsa_signature(u8 **pptr,