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param: make command sinks (fail/success) return a special type.

These routines free the 'struct command': a common coding error is not
to return immediately.

To catch this, we make them return a non-NULL 'struct command_result
*', and we're going to make the command handlers return the same (to
encourage 'return command_fail(...)'-style usage).

We also provide two sources for external use:
1. command_param_failed() when param() fails.
2. command_its_complicated() for some complex cases.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
plugin-7
Rusty Russell 6 years ago
parent
commit
93bf7c4839
  1. 6
      common/json_command.h
  2. 4
      common/test/run-param.c
  3. 38
      lightningd/jsonrpc.c
  4. 36
      lightningd/jsonrpc.h
  5. 11
      lightningd/test/run-invoice-select-inchan.c
  6. 14
      wallet/test/run-wallet.c

6
common/json_command.h

@ -7,10 +7,12 @@
#include <stdbool.h>
struct command;
struct command_result;
/* Caller supplied this: param assumes it can call it. */
void PRINTF_FMT(3, 4) command_fail(struct command *cmd, int code,
const char *fmt, ...);
struct command_result *command_fail(struct command *cmd, int code,
const char *fmt, ...)
PRINTF_FMT(3, 4);
/* Also caller supplied: is this invoked simply to get usage? */
bool command_usage_only(const struct command *cmd);

4
common/test/run-param.c

@ -22,13 +22,15 @@ static bool check_fail(void) {
struct command *cmd;
void command_fail(struct command *cmd, int code, const char *fmt, ...)
struct command_result *command_fail(struct command *cmd,
int code, const char *fmt, ...)
{
failed = true;
va_list ap;
va_start(ap, fmt);
fail_msg = tal_vfmt(cmd, fmt, ap);
va_end(ap);
return NULL;
}
/* AUTOGENERATED MOCKS START */

38
lightningd/jsonrpc.c

@ -45,6 +45,23 @@
#include <sys/types.h>
#include <sys/un.h>
/* Dummy structure. */
struct command_result {
char c;
};
static struct command_result param_failed, complete, pending, unknown;
struct command_result *command_param_failed(void)
{
return &param_failed;
}
struct command_result *command_its_complicated(void)
{
return &unknown;
}
/* This represents a JSON RPC connection. It can invoke multiple commands, but
* a command can outlive the connection, which could close any time. */
struct json_connection {
@ -383,7 +400,8 @@ static void destroy_command(struct command *cmd)
list_del_from(&cmd->jcon->commands, &cmd->list);
}
void command_raw_complete(struct command *cmd, struct json_stream *result)
struct command_result *command_raw_complete(struct command *cmd,
struct json_stream *result)
{
json_stream_close(result, cmd);
@ -392,27 +410,30 @@ void command_raw_complete(struct command *cmd, struct json_stream *result)
tal_steal(cmd->jcon, result);
tal_free(cmd);
return &complete;
}
void command_success(struct command *cmd, struct json_stream *result)
struct command_result *command_success(struct command *cmd,
struct json_stream *result)
{
assert(cmd);
assert(cmd->have_json_stream);
json_stream_append(result, " }\n\n");
command_raw_complete(cmd, result);
return command_raw_complete(cmd, result);
}
void command_failed(struct command *cmd, struct json_stream *result)
struct command_result *command_failed(struct command *cmd,
struct json_stream *result)
{
assert(cmd->have_json_stream);
/* Have to close error */
json_stream_append(result, " } }\n\n");
command_raw_complete(cmd, result);
return command_raw_complete(cmd, result);
}
void PRINTF_FMT(3, 4) command_fail(struct command *cmd, int code,
struct command_result *command_fail(struct command *cmd, int code,
const char *fmt, ...)
{
const char *errmsg;
@ -424,13 +445,14 @@ void PRINTF_FMT(3, 4) command_fail(struct command *cmd, int code,
va_end(ap);
r = json_stream_fail_nodata(cmd, code, errmsg);
command_failed(cmd, r);
return command_failed(cmd, r);
}
void command_still_pending(struct command *cmd)
struct command_result *command_still_pending(struct command *cmd)
{
notleak_with_children(cmd);
cmd->pending = true;
return &pending;
}
static void json_command_malformed(struct json_connection *jcon,

36
lightningd/jsonrpc.h

@ -41,6 +41,12 @@ struct command {
bool have_json_stream;
};
/**
* Dummy structure to make sure you call one of
* command_success / command_failed / command_still_pending.
*/
struct command_result;
struct json_command {
const char *name;
void (*dispatch)(struct command *,
@ -87,15 +93,37 @@ struct json_stream *json_stream_fail_nodata(struct command *cmd,
const char *errmsg);
struct json_stream *null_response(struct command *cmd);
void command_success(struct command *cmd, struct json_stream *response);
void command_failed(struct command *cmd, struct json_stream *result);
/* These returned values are never NULL. */
struct command_result *command_success(struct command *cmd,
struct json_stream *response);
struct command_result *command_failed(struct command *cmd,
struct json_stream *result);
/* Mainly for documentation, that we plan to close this later. */
void command_still_pending(struct command *cmd);
struct command_result *command_still_pending(struct command *cmd);
/* For low-level JSON stream access: */
struct json_stream *json_stream_raw_for_cmd(struct command *cmd);
void command_raw_complete(struct command *cmd, struct json_stream *result);
struct command_result *command_raw_complete(struct command *cmd,
struct json_stream *result);
/* To return if param() fails. */
extern struct command_result *command_param_failed(void);
/* Wrapper for pending commands (ignores return) */
static inline void was_pending(const struct command_result *res)
{
assert(res);
}
/* Transition for ignoring command */
static inline void fixme_ignore(const struct command_result *res)
{
}
/* FIXME: For the few cases where return value is indeterminate */
struct command_result *command_its_complicated(void);
/**
* Create a new jsonrpc to wrap all related information.

11
lightningd/test/run-invoice-select-inchan.c

@ -41,17 +41,20 @@ bool channel_tell_funding_locked(struct lightningd *ld UNNEEDED,
u32 depth UNNEEDED)
{ fprintf(stderr, "channel_tell_funding_locked called!\n"); abort(); }
/* Generated stub for command_fail */
void command_fail(struct command *cmd UNNEEDED, int code UNNEEDED,
struct command_result *command_fail(struct command *cmd UNNEEDED, int code UNNEEDED,
const char *fmt UNNEEDED, ...)
{ fprintf(stderr, "command_fail called!\n"); abort(); }
/* Generated stub for command_failed */
void command_failed(struct command *cmd UNNEEDED, struct json_stream *result UNNEEDED)
struct command_result *command_failed(struct command *cmd UNNEEDED,
struct json_stream *result UNNEEDED)
{ fprintf(stderr, "command_failed called!\n"); abort(); }
/* Generated stub for command_still_pending */
void command_still_pending(struct command *cmd UNNEEDED)
struct command_result *command_still_pending(struct command *cmd UNNEEDED)
{ fprintf(stderr, "command_still_pending called!\n"); abort(); }
/* Generated stub for command_success */
void command_success(struct command *cmd UNNEEDED, struct json_stream *response UNNEEDED)
struct command_result *command_success(struct command *cmd UNNEEDED,
struct json_stream *response UNNEEDED)
{ fprintf(stderr, "command_success called!\n"); abort(); }
/* Generated stub for connect_succeeded */
void connect_succeeded(struct lightningd *ld UNNEEDED, const struct pubkey *id UNNEEDED)

14
wallet/test/run-wallet.c

@ -51,14 +51,16 @@ bool channel_tell_funding_locked(struct lightningd *ld UNNEEDED,
u32 depth UNNEEDED)
{ fprintf(stderr, "channel_tell_funding_locked called!\n"); abort(); }
/* Generated stub for command_fail */
void command_fail(struct command *cmd UNNEEDED, int code UNNEEDED,
struct command_result *command_fail(struct command *cmd UNNEEDED, int code UNNEEDED,
const char *fmt UNNEEDED, ...)
{ fprintf(stderr, "command_fail called!\n"); abort(); }
/* Generated stub for command_still_pending */
void command_still_pending(struct command *cmd UNNEEDED)
struct command_result *command_still_pending(struct command *cmd UNNEEDED)
{ fprintf(stderr, "command_still_pending called!\n"); abort(); }
/* Generated stub for command_success */
void command_success(struct command *cmd UNNEEDED, struct json_stream *response UNNEEDED)
struct command_result *command_success(struct command *cmd UNNEEDED,
struct json_stream *response UNNEEDED)
{ fprintf(stderr, "command_success called!\n"); abort(); }
/* Generated stub for connect_succeeded */
void connect_succeeded(struct lightningd *ld UNNEEDED, const struct pubkey *id UNNEEDED)
@ -264,6 +266,12 @@ bool json_tok_bool(struct command *cmd UNNEEDED, const char *name UNNEEDED,
bool json_tok_channel_id(const char *buffer UNNEEDED, const jsmntok_t *tok UNNEEDED,
struct channel_id *cid UNNEEDED)
{ fprintf(stderr, "json_tok_channel_id called!\n"); abort(); }
/* Generated stub for json_tok_full */
const char *json_tok_full(const char *buffer UNNEEDED, const jsmntok_t *t UNNEEDED)
{ fprintf(stderr, "json_tok_full called!\n"); abort(); }
/* Generated stub for json_tok_full_len */
int json_tok_full_len(const jsmntok_t *t UNNEEDED)
{ fprintf(stderr, "json_tok_full_len called!\n"); abort(); }
/* Generated stub for json_tok_loglevel */
bool json_tok_loglevel(struct command *cmd UNNEEDED, const char *name UNNEEDED,
const char *buffer UNNEEDED, const jsmntok_t *tok UNNEEDED,

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