update command_handler documentation

Improve the developer manual and primer sections which talk about
writing command handlers.  Notably, it documents the new CMD_* macros.
This commit is contained in:
Zachary T Welch 2009-11-17 05:38:17 -08:00
parent cfaf7bdd0a
commit 789d47c180
2 changed files with 22 additions and 21 deletions

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@ -45,16 +45,16 @@ another layer of handlers.
@subsection helpercmdhandlerdef Defining and Calling Command Handlers
These functions should be defined using the COMMAND_HANDLER macro.
These functions should be defined using the @c COMMAND_HANDLER macro.
These methods must be defined as static, as their principle entry point
should be the run_command dispatch mechanism.
Command helper functions that require access to the full set of
parameters should be defined using the COMMAND_HELPER. These must be
parameters should be defined using the @c COMMAND_HELPER. These must be
declared static by you, as sometimes you might want to share a helper
among several files (e.g. s3c24xx_nand.h).
among several files (e.g. @c s3c24xx_nand.h).
Both types of routines must be called using the CALL_COMMAND_HANDLER macro.
Both types of routines must be called using the @c CALL_COMMAND_HANDLER macro.
Calls using this macro to normal handlers require the name of the command
handler (which can a name or function pointer). Calls to helpers and
derived handlers must pass those extra parameters specified by their
@ -67,22 +67,18 @@ will be able to use direct invocations.
Thus, the following macros can be used to define and call command
handlers or helpers:
- COMMAND_HANDLER - declare or define a command handler.
- COMMAND_HELPER - declare or define a derived command handler or helper.
- CALL_COMMAND_COMMAND - call a command handler/helper.
@subsection helpercmdhandlerparam Command Handler Parameters
The following parameters are defined in the scope of all command
handlers and helpers:
- <code>struct command_context *cmd_ctx</code> - the command's context
- <code>unsigned argc</code> - the number of command arguments
- <code>const char *args[]</code> - contains the command arguments
- @c COMMAND_HANDLER - declare or define a command handler.
- @c COMMAND_HELPER - declare or define a derived command handler or helper.
- @c CALL_COMMAND_COMMAND - call a command handler/helper.
@subsection helpercmdhandlermacros Command Handler Macros
In addition, the following macro may be used:
- <code>COMMAND_NAME</code> - contains the command name
In addition, the following macros may be used in the context of
command handlers and helpers:
- @c CMD_CTX - the current @c command_context
- @c CMD_NAME - invoked command name
- @c CMD_ARGC - the number of command arguments
- @c CMD_ARGV - array of command argument strings
@section helpercmdprimer Command Development Primer

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@ -16,7 +16,7 @@ COMMAND_HANDLER(handle_hello_command)
const char *sep, *name;
int retval = CALL_COMMAND_HANDLER(handle_hello_args);
if (ERROR_OK == retval)
command_print(cmd_ctx, "Greetings%s%s!", sep, name);
command_print(CMD_CTX, "Greetings%s%s!", sep, name);
return retval;
}
@endcode
@ -39,13 +39,13 @@ static COMMAND_HELPER(handle_hello_args, const char **sep, const char **name)
{
if (argc > 1)
{
LOG_ERROR("%s: too many arguments", COMMAND_NAME);
LOG_ERROR("%s: too many arguments", CMD_NAME);
return ERROR_COMMAND_SYNTAX_ERROR;
}
if (1 == argc)
if (1 == CMD_ARGC)
{
*sep = ", ";
*name = args[0];
*name = CMD_ARGV[0];
}
else
*sep = *name = "";
@ -96,4 +96,9 @@ Greetings, John Doe!
Error: ocd_hello: too many arguments
@endcode
This difference between the registered and displayed command name comes from
the fact that the TCL scripts are provided with a stub that calls the munged
name. This stub wraps the internal <code>ocd_</code>-prefixed routine,
providing a measure of high-level error handling.
*/