helper/command: use one single handler for all the commands

[openocd.git] / src / helper / command.c

/***************************************************************************
 *   Copyright (C) 2005 by Dominic Rath                                    *
 *   Dominic.Rath@gmx.de                                                   *
 *                                                                         *
 *   Copyright (C) 2007,2008 Øyvind Harboe                                 *
 *   oyvind.harboe@zylin.com                                               *
 *                                                                         *
 *   Copyright (C) 2008, Duane Ellis                                       *
 *   openocd@duaneeellis.com                                               *
 *                                                                         *
 *   part of this file is taken from libcli (libcli.sourceforge.net)       *
 *   Copyright (C) David Parrish (david@dparrish.com)                      *
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 *   This program is distributed in the hope that it will be useful,       *
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
 *   GNU General Public License for more details.                          *
 *                                                                         *
 *   You should have received a copy of the GNU General Public License     *
 *   along with this program.  If not, see <http://www.gnu.org/licenses/>. *
 ***************************************************************************/

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

/* see Embedded-HOWTO.txt in Jim Tcl project hosted on BerliOS*/
#define JIM_EMBEDDED

/* @todo the inclusion of target.h here is a layering violation */
#include <jtag/jtag.h>
#include <target/target.h>
#include "command.h"
#include "configuration.h"
#include "log.h"
#include "time_support.h"
#include "jim-eventloop.h"

/* nice short description of source file */
#define __THIS__FILE__ "command.c"

struct log_capture_state {
        Jim_Interp *interp;
        Jim_Obj *output;
};

static int unregister_command(struct command_context *context,
        struct command *parent, const char *name);
static char *command_name(struct command *c, char delim);

static void tcl_output(void *privData, const char *file, unsigned line,
        const char *function, const char *string)
{
        struct log_capture_state *state = privData;
        Jim_AppendString(state->interp, state->output, string, strlen(string));
}

static struct log_capture_state *command_log_capture_start(Jim_Interp *interp)
{
        /* capture log output and return it. A garbage collect can
         * happen, so we need a reference count to this object */
        Jim_Obj *tclOutput = Jim_NewStringObj(interp, "", 0);
        if (NULL == tclOutput)
                return NULL;

        struct log_capture_state *state = malloc(sizeof(*state));
        if (NULL == state)
                return NULL;

        state->interp = interp;
        Jim_IncrRefCount(tclOutput);
        state->output = tclOutput;

        log_add_callback(tcl_output, state);

        return state;
}

/* Classic openocd commands provide progress output which we
 * will capture and return as a Tcl return value.
 *
 * However, if a non-openocd command has been invoked, then it
 * makes sense to return the tcl return value from that command.
 *
 * The tcl return value is empty for openocd commands that provide
 * progress output.
 *
 * Therefore we set the tcl return value only if we actually
 * captured output.
 */
static void command_log_capture_finish(struct log_capture_state *state)
{
        if (NULL == state)
                return;

        log_remove_callback(tcl_output, state);

        int length;
        Jim_GetString(state->output, &length);

        if (length > 0)
                Jim_SetResult(state->interp, state->output);
        else {
                /* No output captured, use tcl return value (which could
                 * be empty too). */
        }
        Jim_DecrRefCount(state->interp, state->output);

        free(state);
}

/*
 * FIXME: workaround for memory leak in jimtcl 0.80
 * Jim API Jim_CreateCommand() converts the command name in a Jim object and
 * does not free the object. Fixed for jimtcl 0.81 by e4416cf86f0b
 * Use the internal jimtcl API Jim_CreateCommandObj, not exported by jim.h,
 * and override the bugged API through preprocessor's macro.
 * This workaround works only when jimtcl is compiled as OpenOCD submodule.
 * If jimtcl is linked-in from a precompiled library, either static or dynamic,
 * the symbol Jim_CreateCommandObj is not exported and the build will use the
 * bugged API.
 * To be removed when OpenOCD will switch to jimtcl 0.81
 */
#if JIM_VERSION == 80
static int workaround_createcommand(Jim_Interp *interp, const char *cmdName,
        Jim_CmdProc *cmdProc, void *privData, Jim_DelCmdProc *delProc);
int Jim_CreateCommandObj(Jim_Interp *interp, Jim_Obj *cmdNameObj,
        Jim_CmdProc *cmdProc, void *privData, Jim_DelCmdProc *delProc)
__attribute__((weak, alias("workaround_createcommand")));
static int workaround_createcommand(Jim_Interp *interp, const char *cmdName,
        Jim_CmdProc *cmdProc, void *privData, Jim_DelCmdProc *delProc)
{
        if ((void *)Jim_CreateCommandObj == (void *)workaround_createcommand)
                return Jim_CreateCommand(interp, cmdName, cmdProc, privData, delProc);

        Jim_Obj *cmd_name = Jim_NewStringObj(interp, cmdName, -1);
        Jim_IncrRefCount(cmd_name);
        int retval = Jim_CreateCommandObj(interp, cmd_name, cmdProc, privData, delProc);
        Jim_DecrRefCount(interp, cmd_name);
        return retval;
}
#define Jim_CreateCommand workaround_createcommand
#endif /* JIM_VERSION == 80 */
/* FIXME: end of workaround for memory leak in jimtcl 0.80 */

static int command_retval_set(Jim_Interp *interp, int retval)
{
        int *return_retval = Jim_GetAssocData(interp, "retval");
        if (return_retval != NULL)
                *return_retval = retval;

        return (retval == ERROR_OK) ? JIM_OK : retval;
}

extern struct command_context *global_cmd_ctx;

/* dump a single line to the log for the command.
 * Do nothing in case we are not at debug level 3 */
void script_debug(Jim_Interp *interp, unsigned int argc, Jim_Obj * const *argv)
{
        if (debug_level < LOG_LVL_DEBUG)
                return;

        char *dbg = alloc_printf("command -");
        for (unsigned i = 0; i < argc; i++) {
                int len;
                const char *w = Jim_GetString(argv[i], &len);
                char *t = alloc_printf("%s %s", dbg, w);
                free(dbg);
                dbg = t;
        }
        LOG_DEBUG("%s", dbg);
        free(dbg);
}

static void script_command_args_free(char **words, unsigned nwords)
{
        for (unsigned i = 0; i < nwords; i++)
                free(words[i]);
        free(words);
}

static char **script_command_args_alloc(
        unsigned argc, Jim_Obj * const *argv, unsigned *nwords)
{
        char **words = malloc(argc * sizeof(char *));
        if (NULL == words)
                return NULL;

        unsigned i;
        for (i = 0; i < argc; i++) {
                int len;
                const char *w = Jim_GetString(argv[i], &len);
                words[i] = strdup(w);
                if (words[i] == NULL) {
                        script_command_args_free(words, i);
                        return NULL;
                }
        }
        *nwords = i;
        return words;
}

struct command_context *current_command_context(Jim_Interp *interp)
{
        /* grab the command context from the associated data */
        struct command_context *cmd_ctx = Jim_GetAssocData(interp, "context");
        if (NULL == cmd_ctx) {
                /* Tcl can invoke commands directly instead of via command_run_line(). This would
                 * happen when the Jim Tcl interpreter is provided by eCos or if we are running
                 * commands in a startup script.
                 *
                 * A telnet or gdb server would provide a non-default command context to
                 * handle piping of error output, have a separate current target, etc.
                 */
                cmd_ctx = global_cmd_ctx;
        }
        return cmd_ctx;
}

static struct command *command_root(struct command *c)
{
        while (NULL != c->parent)
                c = c->parent;
        return c;
}

/**
 * Find a command by name from a list of commands.
 * @returns Returns the named command if it exists in the list.
 * Returns NULL otherwise.
 */
static struct command *command_find(struct command *head, const char *name)
{
        for (struct command *cc = head; cc; cc = cc->next) {
                if (strcmp(cc->name, name) == 0)
                        return cc;
        }
        return NULL;
}

struct command *command_find_in_context(struct command_context *cmd_ctx,
        const char *name)
{
        return command_find(cmd_ctx->commands, name);
}

/**
 * Add the command into the linked list, sorted by name.
 * @param head Address to head of command list pointer, which may be
 * updated if @c c gets inserted at the beginning of the list.
 * @param c The command to add to the list pointed to by @c head.
 */
static void command_add_child(struct command **head, struct command *c)
{
        assert(head);
        if (NULL == *head) {
                *head = c;
                return;
        }

        while ((*head)->next && (strcmp(c->name, (*head)->name) > 0))
                head = &(*head)->next;

        if (strcmp(c->name, (*head)->name) > 0) {
                c->next = (*head)->next;
                (*head)->next = c;
        } else {
                c->next = *head;
                *head = c;
        }
}

static struct command **command_list_for_parent(
        struct command_context *cmd_ctx, struct command *parent)
{
        return parent ? &parent->children : &cmd_ctx->commands;
}

static void command_free(struct command *c)
{
        /** @todo if command has a handler, unregister its jim command! */

        while (NULL != c->children) {
                struct command *tmp = c->children;
                c->children = tmp->next;
                command_free(tmp);
        }

        free(c->name);
        free(c->help);
        free(c->usage);
        free(c);
}

static struct command *command_new(struct command_context *cmd_ctx,
        struct command *parent, const struct command_registration *cr)
{
        assert(cr->name);

        /*
         * If it is a non-jim command with no .usage specified,
         * log an error.
         *
         * strlen(.usage) == 0 means that the command takes no
         * arguments.
        */
        if ((cr->jim_handler == NULL) && (cr->usage == NULL)) {
                LOG_ERROR("BUG: command '%s%s%s' does not have the "
                        "'.usage' field filled out",
                        parent && parent->name ? parent->name : "",
                        parent && parent->name ? " " : "",
                        cr->name);
        }

        struct command *c = calloc(1, sizeof(struct command));
        if (NULL == c)
                return NULL;

        c->name = strdup(cr->name);
        if (cr->help)
                c->help = strdup(cr->help);
        if (cr->usage)
                c->usage = strdup(cr->usage);

        if (!c->name || (cr->help && !c->help) || (cr->usage && !c->usage))
                goto command_new_error;

        c->parent = parent;
        c->handler = cr->handler;
        c->jim_handler = cr->jim_handler;
        c->mode = cr->mode;

        command_add_child(command_list_for_parent(cmd_ctx, parent), c);

        return c;

command_new_error:
        command_free(c);
        return NULL;
}

static int command_unknown(Jim_Interp *interp, int argc, Jim_Obj *const *argv);

static int register_command_handler(struct command_context *cmd_ctx,
        struct command *c)
{
        Jim_Interp *interp = cmd_ctx->interp;

#if 0
        LOG_DEBUG("registering '%s'...", c->name);
#endif

        return Jim_CreateCommand(interp, c->name, command_unknown, c, NULL);
}

static struct command *register_command(struct command_context *context,
        struct command *parent, const struct command_registration *cr)
{
        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) {
                /* TODO: originally we treated attempting to register a cmd twice as an error
                 * Sometimes we need this behaviour, such as with flash banks.
                 * http://www.mail-archive.com/openocd-development@lists.berlios.de/msg11152.html */
                LOG_DEBUG("command '%s' is already registered in '%s' context",
                        name, parent ? parent->name : "<global>");
                return c;
        }

        c = command_new(context, parent, cr);
        if (NULL == c)
                return NULL;

        if (cr->jim_handler || cr->handler) {
                int retval = register_command_handler(context, command_root(c));
                if (retval != JIM_OK) {
                        unregister_command(context, parent, name);
                        return NULL;
                }
        }
        return c;
}

int register_commands(struct command_context *cmd_ctx, struct command *parent,
        const struct command_registration *cmds)
{
        int retval = ERROR_OK;
        unsigned i;
        for (i = 0; cmds[i].name || cmds[i].chain; i++) {
                const struct command_registration *cr = cmds + i;

                struct command *c = NULL;
                if (NULL != cr->name) {
                        c = register_command(cmd_ctx, parent, cr);
                        if (NULL == c) {
                                retval = ERROR_FAIL;
                                break;
                        }
                }
                if (NULL != cr->chain) {
                        struct command *p = c ? : parent;
                        retval = register_commands(cmd_ctx, p, cr->chain);
                        if (ERROR_OK != retval)
                                break;
                }
        }
        if (ERROR_OK != retval) {
                for (unsigned j = 0; j < i; j++)
                        unregister_command(cmd_ctx, parent, cmds[j].name);
        }
        return retval;
}

int unregister_all_commands(struct command_context *context,
        struct command *parent)
{
        if (context == NULL)
                return ERROR_OK;

        struct command **head = command_list_for_parent(context, parent);
        while (NULL != *head) {
                struct command *tmp = *head;
                *head = tmp->next;
                command_free(tmp);
        }

        return ERROR_OK;
}

static int unregister_command(struct command_context *context,
        struct command *parent, const char *name)
{
        if ((!context) || (!name))
                return ERROR_COMMAND_SYNTAX_ERROR;

        struct command *p = NULL;
        struct command **head = command_list_for_parent(context, parent);
        for (struct command *c = *head; NULL != c; p = c, c = c->next) {
                if (strcmp(name, c->name) != 0)
                        continue;

                if (p)
                        p->next = c->next;
                else
                        *head = c->next;

                command_free(c);
                return ERROR_OK;
        }

        return ERROR_OK;
}

void command_set_handler_data(struct command *c, void *p)
{
        c->jim_handler_data = p;
        for (struct command *cc = c->children; NULL != cc; cc = cc->next)
                command_set_handler_data(cc, p);
}

void command_output_text(struct command_context *context, const char *data)
{
        if (context && context->output_handler && data)
                context->output_handler(context, data);
}

void command_print_sameline(struct command_invocation *cmd, const char *format, ...)
{
        char *string;

        va_list ap;
        va_start(ap, format);

        string = alloc_vprintf(format, ap);
        if (string != NULL && cmd) {
                /* we want this collected in the log + we also want to pick it up as a tcl return
                 * value.
                 *
                 * The latter bit isn't precisely neat, but will do for now.
                 */
                Jim_AppendString(cmd->ctx->interp, cmd->output, string, -1);
                /* We already printed it above
                 * command_output_text(context, string); */
                free(string);
        }

        va_end(ap);
}

void command_print(struct command_invocation *cmd, const char *format, ...)
{
        char *string;

        va_list ap;
        va_start(ap, format);

        string = alloc_vprintf(format, ap);
        if (string != NULL && cmd) {
                strcat(string, "\n");   /* alloc_vprintf guaranteed the buffer to be at least one
                                         *char longer */
                /* we want this collected in the log + we also want to pick it up as a tcl return
                 * value.
                 *
                 * The latter bit isn't precisely neat, but will do for now.
                 */
                Jim_AppendString(cmd->ctx->interp, cmd->output, string, -1);
                /* We already printed it above
                 * command_output_text(context, string); */
                free(string);
        }

        va_end(ap);
}

static char *__command_name(struct command *c, char delim, unsigned extra)
{
        char *name;
        unsigned len = strlen(c->name);
        if (NULL == c->parent) {
                /* allocate enough for the name, child names, and '\0' */
                name = malloc(len + extra + 1);
                if (!name) {
                        LOG_ERROR("Out of memory");
                        return NULL;
                }
                strcpy(name, c->name);
        } else {
                /* parent's extra must include both the space and name */
                name = __command_name(c->parent, delim, 1 + len + extra);
                char dstr[2] = { delim, 0 };
                strcat(name, dstr);
                strcat(name, c->name);
        }
        return name;
}

static char *command_name(struct command *c, char delim)
{
        return __command_name(c, delim, 0);
}

static bool command_can_run(struct command_context *cmd_ctx, struct command *c)
{
        if (c->mode == COMMAND_ANY || c->mode == cmd_ctx->mode)
                return true;

        /* Many commands may be run only before/after 'init' */
        const char *when;
        switch (c->mode) {
                case COMMAND_CONFIG:
                        when = "before";
                        break;
                case COMMAND_EXEC:
                        when = "after";
                        break;
                /* handle the impossible with humor; it guarantees a bug report! */
                default:
                        when = "if Cthulhu is summoned by";
                        break;
        }
        char *full_name = command_name(c, ' ');
        LOG_ERROR("The '%s' command must be used %s 'init'.",
                        full_name ? full_name : c->name, when);
        free(full_name);
        return false;
}

static int run_command(struct command_context *context,
        struct command *c, const char **words, unsigned num_words)
{
        struct command_invocation cmd = {
                .ctx = context,
                .current = c,
                .name = c->name,
                .argc = num_words - 1,
                .argv = words + 1,
        };

        cmd.output = Jim_NewEmptyStringObj(context->interp);
        Jim_IncrRefCount(cmd.output);

        int retval = c->handler(&cmd);
        if (retval == ERROR_COMMAND_SYNTAX_ERROR) {
                /* Print help for command */
                char *full_name = command_name(c, ' ');
                if (NULL != full_name) {
                        command_run_linef(context, "usage %s", full_name);
                        free(full_name);
                }
        } else if (retval == ERROR_COMMAND_CLOSE_CONNECTION) {
                /* just fall through for a shutdown request */
        } else {
                if (retval != ERROR_OK) {
                        char *full_name = command_name(c, ' ');
                        LOG_DEBUG("Command '%s' failed with error code %d",
                                                full_name ? full_name : c->name, retval);
                        free(full_name);
                }
                /* Use the command output as the Tcl result */
                Jim_SetResult(context->interp, cmd.output);
        }
        Jim_DecrRefCount(context->interp, cmd.output);

        return retval;
}

int command_run_line(struct command_context *context, char *line)
{
        /* all the parent commands have been registered with the interpreter
         * so, can just evaluate the line as a script and check for
         * results
         */
        /* run the line thru a script engine */
        int retval = ERROR_FAIL;
        int retcode;
        /* Beware! This code needs to be reentrant. It is also possible
         * for OpenOCD commands to be invoked directly from Tcl. This would
         * happen when the Jim Tcl interpreter is provided by eCos for
         * instance.
         */
        struct target *saved_target_override = context->current_target_override;
        context->current_target_override = NULL;

        Jim_Interp *interp = context->interp;
        struct command_context *old_context = Jim_GetAssocData(interp, "context");
        Jim_DeleteAssocData(interp, "context");
        retcode = Jim_SetAssocData(interp, "context", NULL, context);
        if (retcode == JIM_OK) {
                /* associated the return value */
                Jim_DeleteAssocData(interp, "retval");
                retcode = Jim_SetAssocData(interp, "retval", NULL, &retval);
                if (retcode == JIM_OK) {
                        retcode = Jim_Eval_Named(interp, line, 0, 0);

                        Jim_DeleteAssocData(interp, "retval");
                }
                Jim_DeleteAssocData(interp, "context");
                int inner_retcode = Jim_SetAssocData(interp, "context", NULL, old_context);
                if (retcode == JIM_OK)
                        retcode = inner_retcode;
        }
        context->current_target_override = saved_target_override;
        if (retcode == JIM_OK) {
                const char *result;
                int reslen;

                result = Jim_GetString(Jim_GetResult(interp), &reslen);
                if (reslen > 0) {
                        command_output_text(context, result);
                        command_output_text(context, "\n");
                }
                retval = ERROR_OK;
        } else if (retcode == JIM_EXIT) {
                /* ignore.
                 * exit(Jim_GetExitCode(interp)); */
        } else if (retcode == ERROR_COMMAND_CLOSE_CONNECTION) {
                return retcode;
        } else {
                Jim_MakeErrorMessage(interp);
                /* error is broadcast */
                LOG_USER("%s", Jim_GetString(Jim_GetResult(interp), NULL));

                if (retval == ERROR_OK) {
                        /* It wasn't a low level OpenOCD command that failed */
                        return ERROR_FAIL;
                }
                return retval;
        }

        return retval;
}

int command_run_linef(struct command_context *context, const char *format, ...)
{
        int retval = ERROR_FAIL;
        char *string;
        va_list ap;
        va_start(ap, format);
        string = alloc_vprintf(format, ap);
        if (string != NULL) {
                retval = command_run_line(context, string);
                free(string);
        }
        va_end(ap);
        return retval;
}

void command_set_output_handler(struct command_context *context,
        command_output_handler_t output_handler, void *priv)
{
        context->output_handler = output_handler;
        context->output_handler_priv = priv;
}

struct command_context *copy_command_context(struct command_context *context)
{
        struct command_context *copy_context = malloc(sizeof(struct command_context));

        *copy_context = *context;

        return copy_context;
}

void command_done(struct command_context *cmd_ctx)
{
        if (NULL == cmd_ctx)
                return;

        free(cmd_ctx);
}

/* find full path to file */
static int jim_find(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
{
        if (argc != 2)
                return JIM_ERR;
        const char *file = Jim_GetString(argv[1], NULL);
        char *full_path = find_file(file);
        if (full_path == NULL)
                return JIM_ERR;
        Jim_Obj *result = Jim_NewStringObj(interp, full_path, strlen(full_path));
        free(full_path);

        Jim_SetResult(interp, result);
        return JIM_OK;
}

COMMAND_HANDLER(jim_echo)
{
        if (CMD_ARGC == 2 && !strcmp(CMD_ARGV[0], "-n")) {
                LOG_USER_N("%s", CMD_ARGV[1]);
                return JIM_OK;
        }
        if (CMD_ARGC != 1)
                return JIM_ERR;
        LOG_USER("%s", CMD_ARGV[0]);
        return JIM_OK;
}

/* Capture progress output and return as tcl return value. If the
 * progress output was empty, return tcl return value.
 */
static int jim_capture(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
{
        if (argc != 2)
                return JIM_ERR;

        struct log_capture_state *state = command_log_capture_start(interp);

        /* disable polling during capture. This avoids capturing output
         * from polling.
         *
         * This is necessary in order to avoid accidentally getting a non-empty
         * string for tcl fn's.
         */
        bool save_poll = jtag_poll_get_enabled();

        jtag_poll_set_enabled(false);

        const char *str = Jim_GetString(argv[1], NULL);
        int retcode = Jim_Eval_Named(interp, str, __THIS__FILE__, __LINE__);

        jtag_poll_set_enabled(save_poll);

        command_log_capture_finish(state);

        return retcode;
}

static COMMAND_HELPER(command_help_find, struct command *head,
        struct command **out)
{
        if (0 == CMD_ARGC)
                return ERROR_COMMAND_SYNTAX_ERROR;
        *out = command_find(head, CMD_ARGV[0]);
        if (NULL == *out)
                return ERROR_COMMAND_SYNTAX_ERROR;
        if (--CMD_ARGC == 0)
                return ERROR_OK;
        CMD_ARGV++;
        return CALL_COMMAND_HANDLER(command_help_find, (*out)->children, out);
}

static COMMAND_HELPER(command_help_show, struct command *c, unsigned n,
        bool show_help, const char *cmd_match);

static COMMAND_HELPER(command_help_show_list, struct command *head, unsigned n,
        bool show_help, const char *cmd_match)
{
        for (struct command *c = head; NULL != c; c = c->next)
                CALL_COMMAND_HANDLER(command_help_show, c, n, show_help, cmd_match);
        return ERROR_OK;
}

#define HELP_LINE_WIDTH(_n) (int)(76 - (2 * _n))

static void command_help_show_indent(unsigned n)
{
        for (unsigned i = 0; i < n; i++)
                LOG_USER_N("  ");
}
static void command_help_show_wrap(const char *str, unsigned n, unsigned n2)
{
        const char *cp = str, *last = str;
        while (*cp) {
                const char *next = last;
                do {
                        cp = next;
                        do {
                                next++;
                        } while (*next != ' ' && *next != '\t' && *next != '\0');
                } while ((next - last < HELP_LINE_WIDTH(n)) && *next != '\0');
                if (next - last < HELP_LINE_WIDTH(n))
                        cp = next;
                command_help_show_indent(n);
                LOG_USER("%.*s", (int)(cp - last), last);
                last = cp + 1;
                n = n2;
        }
}

static COMMAND_HELPER(command_help_show, struct command *c, unsigned n,
        bool show_help, const char *cmd_match)
{
        char *cmd_name = command_name(c, ' ');
        if (NULL == cmd_name)
                return ERROR_FAIL;

        /* If the match string occurs anywhere, we print out
         * stuff for this command. */
        bool is_match = (strstr(cmd_name, cmd_match) != NULL) ||
                ((c->usage != NULL) && (strstr(c->usage, cmd_match) != NULL)) ||
                ((c->help != NULL) && (strstr(c->help, cmd_match) != NULL));

        if (is_match) {
                command_help_show_indent(n);
                LOG_USER_N("%s", cmd_name);
        }
        free(cmd_name);

        if (is_match) {
                if (c->usage && strlen(c->usage) > 0) {
                        LOG_USER_N(" ");
                        command_help_show_wrap(c->usage, 0, n + 5);
                } else
                        LOG_USER_N("\n");
        }

        if (is_match && show_help) {
                char *msg;

                /* Normal commands are runtime-only; highlight exceptions */
                if (c->mode != COMMAND_EXEC) {
                        const char *stage_msg = "";

                        switch (c->mode) {
                                case COMMAND_CONFIG:
                                        stage_msg = " (configuration command)";
                                        break;
                                case COMMAND_ANY:
                                        stage_msg = " (command valid any time)";
                                        break;
                                default:
                                        stage_msg = " (?mode error?)";
                                        break;
                        }
                        msg = alloc_printf("%s%s", c->help ? : "", stage_msg);
                } else
                        msg = alloc_printf("%s", c->help ? : "");

                if (NULL != msg) {
                        command_help_show_wrap(msg, n + 3, n + 3);
                        free(msg);
                } else
                        return -ENOMEM;
        }

        if (++n > 5) {
                LOG_ERROR("command recursion exceeded");
                return ERROR_FAIL;
        }

        return CALL_COMMAND_HANDLER(command_help_show_list,
                c->children, n, show_help, cmd_match);
}

COMMAND_HANDLER(handle_help_command)
{
        bool full = strcmp(CMD_NAME, "help") == 0;
        int retval;
        struct command *c = CMD_CTX->commands;
        char *cmd_match;

        if (CMD_ARGC <= 0)
                cmd_match = strdup("");

        else {
                cmd_match = strdup(CMD_ARGV[0]);

                for (unsigned int i = 1; i < CMD_ARGC && cmd_match; ++i) {
                        char *prev = cmd_match;
                        cmd_match = alloc_printf("%s %s", prev, CMD_ARGV[i]);
                        free(prev);
                }
        }

        if (cmd_match == NULL) {
                LOG_ERROR("unable to build search string");
                return -ENOMEM;
        }
        retval = CALL_COMMAND_HANDLER(command_help_show_list,
                        c, 0, full, cmd_match);

        free(cmd_match);
        return retval;
}

static int command_unknown_find(unsigned argc, Jim_Obj *const *argv,
        struct command *head, struct command **out)
{
        if (0 == argc)
                return argc;
        const char *cmd_name = Jim_GetString(argv[0], NULL);
        struct command *c = command_find(head, cmd_name);
        if (NULL == c)
                return argc;
        *out = c;
        return command_unknown_find(--argc, ++argv, (*out)->children, out);
}

static char *alloc_concatenate_strings(int argc, Jim_Obj * const *argv)
{
        char *prev, *all;
        int i;

        assert(argc >= 1);

        all = strdup(Jim_GetString(argv[0], NULL));
        if (!all) {
                LOG_ERROR("Out of memory");
                return NULL;
        }

        for (i = 1; i < argc; ++i) {
                prev = all;
                all = alloc_printf("%s %s", all, Jim_GetString(argv[i], NULL));
                free(prev);
                if (!all) {
                        LOG_ERROR("Out of memory");
                        return NULL;
                }
        }

        return all;
}

static int run_usage(Jim_Interp *interp, int argc_valid, int argc, Jim_Obj * const *argv)
{
        struct command_context *cmd_ctx = current_command_context(interp);
        char *command;
        int retval;

        assert(argc_valid >= 1);
        assert(argc >= argc_valid);

        command = alloc_concatenate_strings(argc_valid, argv);
        if (!command)
                return JIM_ERR;

        retval = command_run_linef(cmd_ctx, "usage %s", command);
        if (retval != ERROR_OK) {
                LOG_ERROR("unable to execute command \"usage %s\"", command);
                return JIM_ERR;
        }

        if (argc_valid == argc)
                LOG_ERROR("%s: command requires more arguments", command);
        else {
                free(command);
                command = alloc_concatenate_strings(argc - argc_valid, argv + argc_valid);
                if (!command)
                        return JIM_ERR;
                LOG_ERROR("invalid subcommand \"%s\"", command);
        }

        free(command);
        return retval;
}

static int exec_command(Jim_Interp *interp, struct command_context *cmd_ctx,
                struct command *c, int argc, Jim_Obj *const *argv)
{
        if (c->jim_handler)
                return c->jim_handler(interp, argc, argv);

        /* use c->handler */
        unsigned int nwords;
        char **words = script_command_args_alloc(argc, argv, &nwords);
        if (!words)
                return JIM_ERR;

        int retval = run_command(cmd_ctx, c, (const char **)words, nwords);
        script_command_args_free(words, nwords);
        return command_retval_set(interp, retval);
}

static int command_unknown(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
{
        script_debug(interp, argc, argv);

        struct command_context *cmd_ctx = current_command_context(interp);
        struct command *c = cmd_ctx->commands;
        int remaining = command_unknown_find(argc, argv, c, &c);
        /* if nothing could be consumed, then it's really an unknown command */
        if (remaining == argc) {
                const char *cmd = Jim_GetString(argv[0], NULL);
                LOG_ERROR("Unknown command:\n  %s", cmd);
                return JIM_OK;
        }

        Jim_Obj *const *start;
        unsigned count;
        if (c->handler || c->jim_handler) {
                /* include the command name in the list */
                count = remaining + 1;
                start = argv + (argc - remaining - 1);
        } else {
                count = argc - remaining;
                start = argv;
                run_usage(interp, count, argc, start);
                return JIM_ERR;
        }

        if (!command_can_run(cmd_ctx, c))
                return JIM_ERR;

        target_call_timer_callbacks_now();

        /*
         * Black magic of overridden current target:
         * If the command we are going to handle has a target prefix,
         * override the current target temporarily for the time
         * of processing the command.
         * current_target_override is used also for event handlers
         * therefore we prevent touching it if command has no prefix.
         * Previous override is saved and restored back to ensure
         * correct work when command_unknown() is re-entered.
         */
        struct target *saved_target_override = cmd_ctx->current_target_override;
        if (c->jim_handler_data)
                cmd_ctx->current_target_override = c->jim_handler_data;

        int retval = exec_command(interp, cmd_ctx, c, count, start);

        if (c->jim_handler_data)
                cmd_ctx->current_target_override = saved_target_override;

        return retval;
}

static int jim_command_mode(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
{
        struct command_context *cmd_ctx = current_command_context(interp);
        enum command_mode mode;

        if (argc > 1) {
                struct command *c = cmd_ctx->commands;
                int remaining = command_unknown_find(argc - 1, argv + 1, c, &c);
                /* if nothing could be consumed, then it's an unknown command */
                if (remaining == argc - 1) {
                        Jim_SetResultString(interp, "unknown", -1);
                        return JIM_OK;
                }
                mode = c->mode;
        } else
                mode = cmd_ctx->mode;

        const char *mode_str;
        switch (mode) {
                case COMMAND_ANY:
                        mode_str = "any";
                        break;
                case COMMAND_CONFIG:
                        mode_str = "config";
                        break;
                case COMMAND_EXEC:
                        mode_str = "exec";
                        break;
                default:
                        mode_str = "unknown";
                        break;
        }
        Jim_SetResultString(interp, mode_str, -1);
        return JIM_OK;
}

int help_add_command(struct command_context *cmd_ctx, struct command *parent,
        const char *cmd_name, const char *help_text, const char *usage)
{
        struct command **head = command_list_for_parent(cmd_ctx, parent);
        struct command *nc = command_find(*head, cmd_name);
        if (NULL == nc) {
                /* add a new command with help text */
                struct command_registration cr = {
                        .name = cmd_name,
                        .mode = COMMAND_ANY,
                        .help = help_text,
                        .usage = usage ? : "",
                };
                nc = register_command(cmd_ctx, parent, &cr);
                if (NULL == nc) {
                        LOG_ERROR("failed to add '%s' help text", cmd_name);
                        return ERROR_FAIL;
                }
                LOG_DEBUG("added '%s' help text", cmd_name);
                return ERROR_OK;
        }
        if (help_text) {
                bool replaced = false;
                if (nc->help) {
                        free(nc->help);
                        replaced = true;
                }
                nc->help = strdup(help_text);
                if (replaced)
                        LOG_INFO("replaced existing '%s' help", cmd_name);
                else
                        LOG_DEBUG("added '%s' help text", cmd_name);
        }
        if (usage) {
                bool replaced = false;
                if (nc->usage) {
                        if (*nc->usage)
                                replaced = true;
                        free(nc->usage);
                }
                nc->usage = strdup(usage);
                if (replaced)
                        LOG_INFO("replaced existing '%s' usage", cmd_name);
                else
                        LOG_DEBUG("added '%s' usage text", cmd_name);
        }
        return ERROR_OK;
}

COMMAND_HANDLER(handle_help_add_command)
{
        if (CMD_ARGC < 2) {
                LOG_ERROR("%s: insufficient arguments", CMD_NAME);
                return ERROR_COMMAND_SYNTAX_ERROR;
        }

        /* save help text and remove it from argument list */
        const char *str = CMD_ARGV[--CMD_ARGC];
        const char *help = !strcmp(CMD_NAME, "add_help_text") ? str : NULL;
        const char *usage = !strcmp(CMD_NAME, "add_usage_text") ? str : NULL;
        if (!help && !usage) {
                LOG_ERROR("command name '%s' is unknown", CMD_NAME);
                return ERROR_COMMAND_SYNTAX_ERROR;
        }
        /* likewise for the leaf command name */
        const char *cmd_name = CMD_ARGV[--CMD_ARGC];

        struct command *c = NULL;
        if (CMD_ARGC > 0) {
                c = CMD_CTX->commands;
                int retval = CALL_COMMAND_HANDLER(command_help_find, c, &c);
                if (ERROR_OK != retval)
                        return retval;
        }
        return help_add_command(CMD_CTX, c, cmd_name, help, usage);
}

/* sleep command sleeps for <n> milliseconds
 * this is useful in target startup scripts
 */
COMMAND_HANDLER(handle_sleep_command)
{
        bool busy = false;
        if (CMD_ARGC == 2) {
                if (strcmp(CMD_ARGV[1], "busy") == 0)
                        busy = true;
                else
                        return ERROR_COMMAND_SYNTAX_ERROR;
        } else if (CMD_ARGC < 1 || CMD_ARGC > 2)
                return ERROR_COMMAND_SYNTAX_ERROR;

        unsigned long duration = 0;
        int retval = parse_ulong(CMD_ARGV[0], &duration);
        if (ERROR_OK != retval)
                return retval;

        if (!busy) {
                int64_t then = timeval_ms();
                while (timeval_ms() - then < (int64_t)duration) {
                        target_call_timer_callbacks_now();
                        usleep(1000);
                }
        } else
                busy_sleep(duration);

        return ERROR_OK;
}

static const struct command_registration command_subcommand_handlers[] = {
        {
                .name = "mode",
                .mode = COMMAND_ANY,
                .jim_handler = jim_command_mode,
                .usage = "[command_name ...]",
                .help = "Returns the command modes allowed by a command: "
                        "'any', 'config', or 'exec'. If no command is "
                        "specified, returns the current command mode. "
                        "Returns 'unknown' if an unknown command is given. "
                        "Command can be multiple tokens.",
        },
        COMMAND_REGISTRATION_DONE
};

static const struct command_registration command_builtin_handlers[] = {
        {
                .name = "ocd_find",
                .mode = COMMAND_ANY,
                .jim_handler = jim_find,
                .help = "find full path to file",
                .usage = "file",
        },
        {
                .name = "capture",
                .mode = COMMAND_ANY,
                .jim_handler = jim_capture,
                .help = "Capture progress output and return as tcl return value. If the "
                                "progress output was empty, return tcl return value.",
                .usage = "command",
        },
        {
                .name = "echo",
                .handler = jim_echo,
                .mode = COMMAND_ANY,
                .help = "Logs a message at \"user\" priority. "
                        "Output message to stdout. "
                        "Option \"-n\" suppresses trailing newline",
                .usage = "[-n] string",
        },
        {
                .name = "add_help_text",
                .handler = handle_help_add_command,
                .mode = COMMAND_ANY,
                .help = "Add new command help text; "
                        "Command can be multiple tokens.",
                .usage = "command_name helptext_string",
        },
        {
                .name = "add_usage_text",
                .handler = handle_help_add_command,
                .mode = COMMAND_ANY,
                .help = "Add new command usage text; "
                        "command can be multiple tokens.",
                .usage = "command_name usage_string",
        },
        {
                .name = "sleep",
                .handler = handle_sleep_command,
                .mode = COMMAND_ANY,
                .help = "Sleep for specified number of milliseconds.  "
                        "\"busy\" will busy wait instead (avoid this).",
                .usage = "milliseconds ['busy']",
        },
        {
                .name = "help",
                .handler = handle_help_command,
                .mode = COMMAND_ANY,
                .help = "Show full command help; "
                        "command can be multiple tokens.",
                .usage = "[command_name]",
        },
        {
                .name = "usage",
                .handler = handle_help_command,
                .mode = COMMAND_ANY,
                .help = "Show basic command usage; "
                        "command can be multiple tokens.",
                .usage = "[command_name]",
        },
        {
                .name = "command",
                .mode = COMMAND_ANY,
                .help = "core command group (introspection)",
                .chain = command_subcommand_handlers,
                .usage = "",
        },
        COMMAND_REGISTRATION_DONE
};

struct command_context *command_init(const char *startup_tcl, Jim_Interp *interp)
{
        struct command_context *context = calloc(1, sizeof(struct command_context));
        const char *HostOs;

        context->mode = COMMAND_EXEC;

        /* Create a jim interpreter if we were not handed one */
        if (interp == NULL) {
                /* Create an interpreter */
                interp = Jim_CreateInterp();
                /* Add all the Jim core commands */
                Jim_RegisterCoreCommands(interp);
                Jim_InitStaticExtensions(interp);
        }

        context->interp = interp;

        /* Stick to lowercase for HostOS strings. */
#if defined(_MSC_VER)
        /* WinXX - is generic, the forward
         * looking problem is this:
         *
         *   "win32" or "win64"
         *
         * "winxx" is generic.
         */
        HostOs = "winxx";
#elif defined(__linux__)
        HostOs = "linux";
#elif defined(__APPLE__) || defined(__DARWIN__)
        HostOs = "darwin";
#elif defined(__CYGWIN__)
        HostOs = "cygwin";
#elif defined(__MINGW32__)
        HostOs = "mingw32";
#elif defined(__ECOS)
        HostOs = "ecos";
#elif defined(__FreeBSD__)
        HostOs = "freebsd";
#elif defined(__NetBSD__)
        HostOs = "netbsd";
#elif defined(__OpenBSD__)
        HostOs = "openbsd";
#else
#warning "Unrecognized host OS..."
        HostOs = "other";
#endif
        Jim_SetGlobalVariableStr(interp, "ocd_HOSTOS",
                Jim_NewStringObj(interp, HostOs, strlen(HostOs)));

        register_commands(context, NULL, command_builtin_handlers);

        Jim_SetAssocData(interp, "context", NULL, context);
        if (Jim_Eval_Named(interp, startup_tcl, "embedded:startup.tcl", 1) == JIM_ERR) {
                LOG_ERROR("Failed to run startup.tcl (embedded into OpenOCD)");
                Jim_MakeErrorMessage(interp);
                LOG_USER_N("%s", Jim_GetString(Jim_GetResult(interp), NULL));
                exit(-1);
        }
        Jim_DeleteAssocData(interp, "context");

        return context;
}

void command_exit(struct command_context *context)
{
        if (!context)
                return;

        Jim_FreeInterp(context->interp);
        command_done(context);
}

int command_context_mode(struct command_context *cmd_ctx, enum command_mode mode)
{
        if (!cmd_ctx)
                return ERROR_COMMAND_SYNTAX_ERROR;

        cmd_ctx->mode = mode;
        return ERROR_OK;
}

void process_jim_events(struct command_context *cmd_ctx)
{
        static int recursion;
        if (recursion)
                return;

        recursion++;
        Jim_ProcessEvents(cmd_ctx->interp, JIM_ALL_EVENTS | JIM_DONT_WAIT);
        recursion--;
}

#define DEFINE_PARSE_NUM_TYPE(name, type, func, min, max) \
        int parse ## name(const char *str, type * ul) \
        { \
                if (!*str) { \
                        LOG_ERROR("Invalid command argument"); \
                        return ERROR_COMMAND_ARGUMENT_INVALID; \
                } \
                char *end; \
                errno = 0; \
                *ul = func(str, &end, 0); \
                if (*end) { \
                        LOG_ERROR("Invalid command argument"); \
                        return ERROR_COMMAND_ARGUMENT_INVALID; \
                } \
                if ((max == *ul) && (ERANGE == errno)) { \
                        LOG_ERROR("Argument overflow"); \
                        return ERROR_COMMAND_ARGUMENT_OVERFLOW; \
                } \
                if (min && (min == *ul) && (ERANGE == errno)) { \
                        LOG_ERROR("Argument underflow"); \
                        return ERROR_COMMAND_ARGUMENT_UNDERFLOW; \
                } \
                return ERROR_OK; \
        }
DEFINE_PARSE_NUM_TYPE(_ulong, unsigned long, strtoul, 0, ULONG_MAX)
DEFINE_PARSE_NUM_TYPE(_ullong, unsigned long long, strtoull, 0, ULLONG_MAX)
DEFINE_PARSE_NUM_TYPE(_long, long, strtol, LONG_MIN, LONG_MAX)
DEFINE_PARSE_NUM_TYPE(_llong, long long, strtoll, LLONG_MIN, LLONG_MAX)

#define DEFINE_PARSE_WRAPPER(name, type, min, max, functype, funcname) \
        int parse ## name(const char *str, type * ul) \
        { \
                functype n; \
                int retval = parse ## funcname(str, &n); \
                if (ERROR_OK != retval) \
                        return retval; \
                if (n > max) \
                        return ERROR_COMMAND_ARGUMENT_OVERFLOW; \
                if (min) \
                        return ERROR_COMMAND_ARGUMENT_UNDERFLOW; \
                *ul = n; \
                return ERROR_OK; \
        }

#define DEFINE_PARSE_ULONGLONG(name, type, min, max) \
        DEFINE_PARSE_WRAPPER(name, type, min, max, unsigned long long, _ullong)
DEFINE_PARSE_ULONGLONG(_uint, unsigned, 0, UINT_MAX)
DEFINE_PARSE_ULONGLONG(_u64,  uint64_t, 0, UINT64_MAX)
DEFINE_PARSE_ULONGLONG(_u32,  uint32_t, 0, UINT32_MAX)
DEFINE_PARSE_ULONGLONG(_u16,  uint16_t, 0, UINT16_MAX)
DEFINE_PARSE_ULONGLONG(_u8,   uint8_t,  0, UINT8_MAX)

DEFINE_PARSE_ULONGLONG(_target_addr, target_addr_t, 0, TARGET_ADDR_MAX)

#define DEFINE_PARSE_LONGLONG(name, type, min, max) \
        DEFINE_PARSE_WRAPPER(name, type, min, max, long long, _llong)
DEFINE_PARSE_LONGLONG(_int, int,     n < INT_MIN,   INT_MAX)
DEFINE_PARSE_LONGLONG(_s64, int64_t, n < INT64_MIN, INT64_MAX)
DEFINE_PARSE_LONGLONG(_s32, int32_t, n < INT32_MIN, INT32_MAX)
DEFINE_PARSE_LONGLONG(_s16, int16_t, n < INT16_MIN, INT16_MAX)
DEFINE_PARSE_LONGLONG(_s8,  int8_t,  n < INT8_MIN,  INT8_MAX)

static int command_parse_bool(const char *in, bool *out,
        const char *on, const char *off)
{
        if (strcasecmp(in, on) == 0)
                *out = true;
        else if (strcasecmp(in, off) == 0)
                *out = false;
        else
                return ERROR_COMMAND_SYNTAX_ERROR;
        return ERROR_OK;
}

int command_parse_bool_arg(const char *in, bool *out)
{
        if (command_parse_bool(in, out, "on", "off") == ERROR_OK)
                return ERROR_OK;
        if (command_parse_bool(in, out, "enable", "disable") == ERROR_OK)
                return ERROR_OK;
        if (command_parse_bool(in, out, "true", "false") == ERROR_OK)
                return ERROR_OK;
        if (command_parse_bool(in, out, "yes", "no") == ERROR_OK)
                return ERROR_OK;
        if (command_parse_bool(in, out, "1", "0") == ERROR_OK)
                return ERROR_OK;
        return ERROR_COMMAND_SYNTAX_ERROR;
}

COMMAND_HELPER(handle_command_parse_bool, bool *out, const char *label)
{
        switch (CMD_ARGC) {
                case 1: {
                        const char *in = CMD_ARGV[0];
                        if (command_parse_bool_arg(in, out) != ERROR_OK) {
                                LOG_ERROR("%s: argument '%s' is not valid", CMD_NAME, in);
                                return ERROR_COMMAND_SYNTAX_ERROR;
                        }
                }
                        /* fallthrough */
                case 0:
                        LOG_INFO("%s is %s", label, *out ? "enabled" : "disabled");
                        break;
                default:
                        return ERROR_COMMAND_SYNTAX_ERROR;
        }
        return ERROR_OK;
}