add struct command_registration

Add a structure to encapsulate command registration information, rather
than passing them all as parameters.  Enables further API changes that
require additional required or optional parameters.

Updates the register_command API and COMMAND_REGISTER macro to use it,
along with their documentation.

diff --git a/src/helper/command.c b/src/helper/command.c
index 0561c6c5bcbcb53a3e80bb870da64b6fe91649a1..3df60b65a9c02b6ed0d75d631eee256c4024e72d 100644 (file)
--- a/src/helper/command.c
+++ b/src/helper/command.c
@@ -263,13 +263,12 @@ static void command_free(struct command *c)
 }
 
 struct command* register_command(struct command_context *context,
-               struct command *parent, const char *name,
-               command_handler_t handler, enum command_mode mode,
-               const char *help)
+               struct command *parent, const struct command_registration *cr)
 {
-       if (!context || !name)
+       if (!context || !cr->name)
                return NULL;
 
+       const char *name = cr->name;
        struct command **head = command_list_for_parent(context, parent);
        struct command *c = command_find(*head, name);
        if (NULL != c)
@@ -279,7 +278,7 @@ struct command* register_command(struct command_context *context,
                return c;
        }
 
-       c = command_new(context, parent, name, handler, mode, help);
+       c = command_new(context, parent, name, cr->handler, cr->mode, cr->help);
        /* if allocation failed or it is a placeholder (no handler), we're done */
        if (NULL == c || NULL == c->handler)
                return c;
@@ -762,8 +761,12 @@ int help_add_command(struct command_context *cmd_ctx, struct command *parent,
        if (NULL == nc)
        {
                // add a new command with help text
-               nc = register_command(cmd_ctx, parent, cmd_name,
-                               NULL, COMMAND_ANY, help_text);
+               struct command_registration cr = {
+                               .name = cmd_name,
+                               .mode = COMMAND_ANY,
+                               .help = help_text,
+                       };
+               nc = register_command(cmd_ctx, parent, &cr);
                if (NULL == nc)
                {
                        LOG_ERROR("failed to add '%s' help text", cmd_name);

diff --git a/src/helper/command.h b/src/helper/command.h
index 25c05011d649afa7b165206822e573d06d1f96f5..b57ca75d85a3df6ea80cf22d855e2f747b4c19a5 100644 (file)
--- a/src/helper/command.h
+++ b/src/helper/command.h
@@ -177,13 +177,9 @@ struct command
  */
 char *command_name(struct command *c, char delim);
 
-/**
- * Register a command @c handler that can be called from scripts during
- * the execution @c mode specified.
- *
- * If @c parent is non-NULL, the new command will be registered as a
- * sub-command under it; otherwise, it will be available as a top-level
- * command.
+/*
+ * Commands should be registered by filling in one or more of these
+ * structures and passing them to register_command().
  *
  * A conventioal format should be used for help strings, to provide both
  * usage and basic information:
@@ -191,25 +187,48 @@ char *command_name(struct command *c, char delim);
  * "@<options@> ... - some explanation text"
  * @endcode
  *
- * @param cmd_ctx The command_context in which to register the command.
- * @param parent Register this command as a child of this, or NULL to
- * register a top-level command.
  * @param name The name of the command to register, which must not have
- * been registered previously.
+ * been registered previously in the intended context.
  * @param handler The callback function that will be called.  If NULL,
  * then the command serves as a placeholder for its children or a script.
  * @param mode The command mode(s) in which this command may be run.
  * @param help The help text that will be displayed to the user.
+ */
+struct command_registration {
+       const char *name;
+       command_handler_t handler;
+       enum command_mode mode;
+       const char *help;
+};
+
+/**
+ * Register a command @c handler that can be called from scripts during
+ * the execution @c mode specified.
+ *
+ * If @c parent is non-NULL, the new command will be registered as a
+ * sub-command under it; otherwise, it will be available as a top-level
+ * command.
+ *
+ * @param cmd_ctx The command_context in which to register the command.
+ * @param parent Register this command as a child of this, or NULL to
+ * register a top-level command.
+ * @param rec A command_registration record that contains the desired
+ * command parameters.
  * @returns The new command, if successful; otherwise, NULL.
  */
 struct command* register_command(struct command_context *cmd_ctx,
-               struct command *parent, const char *name,
-               command_handler_t handler, enum command_mode mode,
-               const char *help);
+               struct command *parent, const struct command_registration *rec);
 
-// provide a simple shim, for now; allows parameters to be migrated
 #define COMMAND_REGISTER(_cmd_ctx, _parent, _name, _handler, _mode, _help) \
-               register_command(_cmd_ctx, _parent, _name, _handler, _mode, _help)
+       ({ \
+               struct command_registration cr = { \
+                               .name = _name, \
+                               .handler = _handler, \
+                               .mode = _mode, \
+                               .help = _help, \
+                       }; \
+               register_command(_cmd_ctx, _parent, &cr); \
+       })
 
 /**
  * Unregisters command @c name from the given context, @c cmd_ctx.