helper: command: rewrite command 'ocd_find' as COMMAND_HANDLER

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

// SPDX-License-Identifier: GPL-2.0-or-later

/***************************************************************************
 *   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)                      *
 ***************************************************************************/

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

/* @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,
        const char *cmd_prefix, const char *name);
static int jim_command_dispatch(Jim_Interp *interp, int argc, Jim_Obj * const *argv);
static int help_add_command(struct command_context *cmd_ctx,
        const char *cmd_name, const char *help_text, const char *usage_text);
static int help_del_command(struct command_context *cmd_ctx, const char *cmd_name);

/* set of functions to wrap jimtcl internal data */
static inline bool jimcmd_is_proc(Jim_Cmd *cmd)
{
        return cmd->isproc;
}

bool jimcmd_is_oocd_command(Jim_Cmd *cmd)
{
        return !cmd->isproc && cmd->u.native.cmdProc == jim_command_dispatch;
}

void *jimcmd_privdata(Jim_Cmd *cmd)
{
        return cmd->isproc ? NULL : cmd->u.native.privData;
}

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 *jim_output = Jim_NewStringObj(interp, "", 0);
        if (!jim_output)
                return NULL;

        Jim_IncrRefCount(jim_output);

        struct log_capture_state *state = malloc(sizeof(*state));
        if (!state) {
                LOG_ERROR("Out of memory");
                Jim_DecrRefCount(interp, jim_output);
                return NULL;
        }

        state->interp = interp;
        state->output = jim_output;

        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 (!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);
}

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

/**
 * Find a openocd command from fullname.
 * @returns Returns the named command if it is registred in interp.
 * Returns NULL otherwise.
 */
static struct command *command_find_from_name(Jim_Interp *interp, const char *name)
{
        if (!name)
                return NULL;

        Jim_Obj *jim_name = Jim_NewStringObj(interp, name, -1);
        Jim_IncrRefCount(jim_name);
        Jim_Cmd *cmd = Jim_GetCommand(interp, jim_name, JIM_NONE);
        Jim_DecrRefCount(interp, jim_name);
        if (!cmd || jimcmd_is_proc(cmd) || !jimcmd_is_oocd_command(cmd))
                return NULL;

        return jimcmd_privdata(cmd);
}

static struct command *command_new(struct command_context *cmd_ctx,
        const char *full_name, 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 && !cr->usage)
                LOG_ERROR("BUG: command '%s' does not have the "
                        "'.usage' field filled out",
                        full_name);

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

        c->name = strdup(cr->name);
        if (!c->name) {
                free(c);
                return NULL;
        }

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

        if (cr->help || cr->usage)
                help_add_command(cmd_ctx, full_name, cr->help, cr->usage);

        return c;
}

static void command_free(struct Jim_Interp *interp, void *priv)
{
        struct command *c = priv;

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

static struct command *register_command(struct command_context *context,
        const char *cmd_prefix, const struct command_registration *cr)
{
        char *full_name;

        if (!context || !cr->name)
                return NULL;

        if (cmd_prefix)
                full_name = alloc_printf("%s %s", cmd_prefix, cr->name);
        else
                full_name = strdup(cr->name);
        if (!full_name)
                return NULL;

        struct command *c = command_find_from_name(context->interp, full_name);
        if (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", full_name);
                free(full_name);
                return c;
        }

        c = command_new(context, full_name, cr);
        if (!c) {
                free(full_name);
                return NULL;
        }

        if (false) /* too noisy with debug_level 3 */
                LOG_DEBUG("registering '%s'...", full_name);
        int retval = Jim_CreateCommand(context->interp, full_name,
                                jim_command_dispatch, c, command_free);
        if (retval != JIM_OK) {
                command_run_linef(context, "del_help_text {%s}", full_name);
                command_run_linef(context, "del_usage_text {%s}", full_name);
                free(c);
                free(full_name);
                return NULL;
        }

        free(full_name);
        return c;
}

int __register_commands(struct command_context *cmd_ctx, const char *cmd_prefix,
        const struct command_registration *cmds, void *data,
        struct target *override_target)
{
        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 (cr->name) {
                        c = register_command(cmd_ctx, cmd_prefix, cr);
                        if (!c) {
                                retval = ERROR_FAIL;
                                break;
                        }
                        c->jim_handler_data = data;
                        c->jim_override_target = override_target;
                }
                if (cr->chain) {
                        if (cr->name) {
                                if (cmd_prefix) {
                                        char *new_prefix = alloc_printf("%s %s", cmd_prefix, cr->name);
                                        if (!new_prefix) {
                                                retval = ERROR_FAIL;
                                                break;
                                        }
                                        retval = __register_commands(cmd_ctx, new_prefix, cr->chain, data, override_target);
                                        free(new_prefix);
                                } else {
                                        retval = __register_commands(cmd_ctx, cr->name, cr->chain, data, override_target);
                                }
                        } else {
                                retval = __register_commands(cmd_ctx, cmd_prefix, cr->chain, data, override_target);
                        }
                        if (retval != ERROR_OK)
                                break;
                }
        }
        if (retval != ERROR_OK) {
                for (unsigned j = 0; j < i; j++)
                        unregister_command(cmd_ctx, cmd_prefix, cmds[j].name);
        }
        return retval;
}

static __attribute__ ((format (PRINTF_ATTRIBUTE_FORMAT, 2, 3)))
int unregister_commands_match(struct command_context *cmd_ctx, const char *format, ...)
{
        Jim_Interp *interp = cmd_ctx->interp;
        va_list ap;

        va_start(ap, format);
        char *query = alloc_vprintf(format, ap);
        va_end(ap);
        if (!query)
                return ERROR_FAIL;

        char *query_cmd = alloc_printf("info commands {%s}", query);
        free(query);
        if (!query_cmd)
                return ERROR_FAIL;

        int retval = Jim_EvalSource(interp, __THIS__FILE__, __LINE__, query_cmd);
        free(query_cmd);
        if (retval != JIM_OK)
                return ERROR_FAIL;

        Jim_Obj *list = Jim_GetResult(interp);
        Jim_IncrRefCount(list);

        int len = Jim_ListLength(interp, list);
        for (int i = 0; i < len; i++) {
                Jim_Obj *elem = Jim_ListGetIndex(interp, list, i);
                Jim_IncrRefCount(elem);

                const char *name = Jim_GetString(elem, NULL);
                struct command *c = command_find_from_name(interp, name);
                if (!c) {
                        /* not openocd command */
                        Jim_DecrRefCount(interp, elem);
                        continue;
                }
                if (false) /* too noisy with debug_level 3 */
                        LOG_DEBUG("delete command \"%s\"", name);
#if JIM_VERSION >= 80
                Jim_DeleteCommand(interp, elem);
#else
                Jim_DeleteCommand(interp, name);
#endif

                help_del_command(cmd_ctx, name);

                Jim_DecrRefCount(interp, elem);
        }

        Jim_DecrRefCount(interp, list);
        return ERROR_OK;
}

int unregister_all_commands(struct command_context *context,
        const char *cmd_prefix)
{
        if (!context)
                return ERROR_OK;

        if (!cmd_prefix || !*cmd_prefix)
                return unregister_commands_match(context, "*");

        int retval = unregister_commands_match(context, "%s *", cmd_prefix);
        if (retval != ERROR_OK)
                return retval;

        return unregister_commands_match(context, "%s", cmd_prefix);
}

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

        if (!cmd_prefix || !*cmd_prefix)
                return unregister_commands_match(context, "%s", name);

        return unregister_commands_match(context, "%s %s", cmd_prefix, name);
}

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 && 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 && 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 bool command_can_run(struct command_context *cmd_ctx, struct command *c, const char *full_name)
{
        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;
        }
        LOG_ERROR("The '%s' command must be used %s 'init'.",
                        full_name ? full_name : c->name, when);
        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 */
                command_run_linef(context, "usage %s", words[0]);
        } else if (retval == ERROR_COMMAND_CLOSE_CONNECTION) {
                /* just fall through for a shutdown request */
        } else {
                if (retval != ERROR_OK)
                        LOG_DEBUG("Command '%s' failed with error code %d",
                                                words[0], retval);
                /*
                 * Use the command output as the Tcl result.
                 * Drop last '\n' to allow command output concatenation
                 * while keep using command_print() everywhere.
                 */
                const char *output_txt = Jim_String(cmd.output);
                int len = strlen(output_txt);
                if (len && output_txt[len - 1] == '\n')
                        --len;
                Jim_SetResultString(context->interp, output_txt, len);
        }
        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) {
                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 (!cmd_ctx)
                return;

        free(cmd_ctx);
}

/* find full path to file */
COMMAND_HANDLER(handle_find)
{
        if (CMD_ARGC != 1)
                return ERROR_COMMAND_SYNTAX_ERROR;

        char *full_path = find_file(CMD_ARGV[0]);
        if (!full_path)
                return ERROR_COMMAND_ARGUMENT_INVALID;

        command_print(CMD, "%s", full_path);
        free(full_path);

        return ERROR_OK;
}

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

        if (CMD_ARGC != 1)
                return ERROR_FAIL;

        LOG_USER("%s", CMD_ARGV[0]);
        return ERROR_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_mask = jtag_poll_mask();

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

        jtag_poll_unmask(save_poll_mask);

        command_log_capture_finish(state);

        return retcode;
}

struct help_entry {
        struct list_head lh;
        char *cmd_name;
        char *help;
        char *usage;
};

static COMMAND_HELPER(command_help_show, struct help_entry *c,
        bool show_help, const char *cmd_match);

static COMMAND_HELPER(command_help_show_list, bool show_help, const char *cmd_match)
{
        struct help_entry *entry;

        list_for_each_entry(entry, CMD_CTX->help_list, lh)
                CALL_COMMAND_HANDLER(command_help_show, entry, 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 help_entry *c,
        bool show_help, const char *cmd_match)
{
        unsigned int n = 0;
        for (const char *s = strchr(c->cmd_name, ' '); s; s = strchr(s + 1, ' '))
                n++;

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

        if (is_match) {
                if (c->usage && strlen(c->usage) > 0) {
                        char *msg = alloc_printf("%s %s", c->cmd_name, c->usage);
                        command_help_show_wrap(msg, n, n + 5);
                        free(msg);
                } else {
                        command_help_show_wrap(c->cmd_name, n, n + 5);
                }
        }

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

                /* TODO: factorize jim_command_mode() to avoid running jim command here */
                char *request = alloc_printf("command mode %s", c->cmd_name);
                if (!request) {
                        LOG_ERROR("Out of memory");
                        return ERROR_FAIL;
                }
                int retval = Jim_Eval(CMD_CTX->interp, request);
                free(request);
                enum command_mode mode = COMMAND_UNKNOWN;
                if (retval != JIM_ERR) {
                        const char *result = Jim_GetString(Jim_GetResult(CMD_CTX->interp), NULL);
                        if (!strcmp(result, "any"))
                                mode = COMMAND_ANY;
                        else if (!strcmp(result, "config"))
                                mode = COMMAND_CONFIG;
                        else if (!strcmp(result, "exec"))
                                mode = COMMAND_EXEC;
                }

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

                        switch (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 ? c->help : "", stage_msg);
                } else
                        msg = alloc_printf("%s", c->help ? c->help : "");

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

        return ERROR_OK;
}

COMMAND_HANDLER(handle_help_command)
{
        bool full = strcmp(CMD_NAME, "help") == 0;
        int retval;
        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) {
                LOG_ERROR("unable to build search string");
                return -ENOMEM;
        }
        retval = CALL_COMMAND_HANDLER(command_help_show_list, full, cmd_match);

        free(cmd_match);
        return retval;
}

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 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 jim_command_dispatch(Jim_Interp *interp, int argc, Jim_Obj * const *argv)
{
        /* check subcommands */
        if (argc > 1) {
                char *s = alloc_printf("%s %s", Jim_GetString(argv[0], NULL), Jim_GetString(argv[1], NULL));
                Jim_Obj *js = Jim_NewStringObj(interp, s, -1);
                Jim_IncrRefCount(js);
                free(s);
                Jim_Cmd *cmd = Jim_GetCommand(interp, js, JIM_NONE);
                if (cmd) {
                        int retval = Jim_EvalObjPrefix(interp, js, argc - 2, argv + 2);
                        Jim_DecrRefCount(interp, js);
                        return retval;
                }
                Jim_DecrRefCount(interp, js);
        }

        script_debug(interp, argc, argv);

        struct command *c = jim_to_command(interp);
        if (!c->jim_handler && !c->handler) {
                Jim_EvalObjPrefix(interp, Jim_NewStringObj(interp, "usage", -1), 1, argv);
                return JIM_ERR;
        }

        struct command_context *cmd_ctx = current_command_context(interp);

        if (!command_can_run(cmd_ctx, c, Jim_GetString(argv[0], NULL)))
                return JIM_ERR;

        target_call_timer_callbacks();

        /*
         * 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 jim_command_dispatch() is re-entered.
         */
        struct target *saved_target_override = cmd_ctx->current_target_override;
        if (c->jim_override_target)
                cmd_ctx->current_target_override = c->jim_override_target;

        int retval = exec_command(interp, cmd_ctx, c, argc, argv);

        if (c->jim_override_target)
                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) {
                char *full_name = alloc_concatenate_strings(argc - 1, argv + 1);
                if (!full_name)
                        return JIM_ERR;
                Jim_Obj *s = Jim_NewStringObj(interp, full_name, -1);
                Jim_IncrRefCount(s);
                Jim_Cmd *cmd = Jim_GetCommand(interp, s, JIM_NONE);
                Jim_DecrRefCount(interp, s);
                free(full_name);
                if (!cmd || !(jimcmd_is_proc(cmd) || jimcmd_is_oocd_command(cmd))) {
                        Jim_SetResultString(interp, "unknown", -1);
                        return JIM_OK;
                }

                if (jimcmd_is_proc(cmd)) {
                        /* tcl proc */
                        mode = COMMAND_ANY;
                } else {
                        struct command *c = jimcmd_privdata(cmd);

                        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_del_all_commands(struct command_context *cmd_ctx)
{
        struct help_entry *curr, *n;

        list_for_each_entry_safe(curr, n, cmd_ctx->help_list, lh) {
                list_del(&curr->lh);
                free(curr->cmd_name);
                free(curr->help);
                free(curr->usage);
                free(curr);
        }
        return ERROR_OK;
}

static int help_del_command(struct command_context *cmd_ctx, const char *cmd_name)
{
        struct help_entry *curr;

        list_for_each_entry(curr, cmd_ctx->help_list, lh) {
                if (!strcmp(cmd_name, curr->cmd_name)) {
                        list_del(&curr->lh);
                        free(curr->cmd_name);
                        free(curr->help);
                        free(curr->usage);
                        free(curr);
                        break;
                }
        }

        return ERROR_OK;
}

static int help_add_command(struct command_context *cmd_ctx,
        const char *cmd_name, const char *help_text, const char *usage_text)
{
        int cmp = -1; /* add after curr */
        struct help_entry *curr;

        list_for_each_entry_reverse(curr, cmd_ctx->help_list, lh) {
                cmp = strcmp(cmd_name, curr->cmd_name);
                if (cmp >= 0)
                        break;
        }

        struct help_entry *entry;
        if (cmp) {
                entry = calloc(1, sizeof(*entry));
                if (!entry) {
                        LOG_ERROR("Out of memory");
                        return ERROR_FAIL;
                }
                entry->cmd_name = strdup(cmd_name);
                if (!entry->cmd_name) {
                        LOG_ERROR("Out of memory");
                        free(entry);
                        return ERROR_FAIL;
                }
                list_add(&entry->lh, &curr->lh);
        } else {
                entry = curr;
        }

        if (help_text) {
                char *text = strdup(help_text);
                if (!text) {
                        LOG_ERROR("Out of memory");
                        return ERROR_FAIL;
                }
                free(entry->help);
                entry->help = text;
        }

        if (usage_text) {
                char *text = strdup(usage_text);
                if (!text) {
                        LOG_ERROR("Out of memory");
                        return ERROR_FAIL;
                }
                free(entry->usage);
                entry->usage = text;
        }

        return ERROR_OK;
}

COMMAND_HANDLER(handle_help_add_command)
{
        if (CMD_ARGC != 2)
                return ERROR_COMMAND_SYNTAX_ERROR;

        const char *help = !strcmp(CMD_NAME, "add_help_text") ? CMD_ARGV[1] : NULL;
        const char *usage = !strcmp(CMD_NAME, "add_usage_text") ? CMD_ARGV[1] : NULL;
        if (!help && !usage) {
                LOG_ERROR("command name '%s' is unknown", CMD_NAME);
                return ERROR_COMMAND_SYNTAX_ERROR;
        }
        const char *cmd_name = CMD_ARGV[0];
        return help_add_command(CMD_CTX, 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 (retval != ERROR_OK)
                return retval;

        if (!busy) {
                int64_t then = timeval_ms();
                while (timeval_ms() - then < (int64_t)duration) {
                        target_call_timer_callbacks_now();
                        keep_alive();
                        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,
                .handler = handle_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 = handle_echo,
                .mode = COMMAND_ANY,
                .help = "Logs a message at \"user\" priority. "
                        "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));

        context->mode = COMMAND_EXEC;

        /* context can be duplicated. Put list head on separate mem-chunk to keep list consistent */
        context->help_list = malloc(sizeof(*context->help_list));
        INIT_LIST_HEAD(context->help_list);

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

        context->interp = interp;

        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);
        free(context->help_list);
        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) && (errno == ERANGE)) { \
                        LOG_ERROR("Argument overflow"); \
                        return ERROR_COMMAND_ARGUMENT_OVERFLOW; \
                } \
                if (min && (min == *ul) && (errno == ERANGE)) { \
                        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 (retval != ERROR_OK) \
                        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;
}