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From: | Wenchao Xia |
Subject: | Re: [Qemu-devel] [PATCH V6 08/13] monitor: refine parse_cmdline() |
Date: | Thu, 18 Jul 2013 10:01:42 +0800 |
User-agent: | Mozilla/5.0 (Windows NT 5.1; rv:17.0) Gecko/20130620 Thunderbird/17.0.7 |
δΊ 2013-7-18 3:39, Luiz Capitulino ει:
On Thu, 11 Jul 2013 11:13:44 +0800 Wenchao Xia <address@hidden> wrote:Since this function will be used by help_cmd() later, so improve it to make it more generic and easier to use. free_cmdline_args() is added to as paired function to free the result. Signed-off-by: Wenchao Xia <address@hidden> --- monitor.c | 52 ++++++++++++++++++++++++++++++++++++++-------------- 1 files changed, 38 insertions(+), 14 deletions(-) diff --git a/monitor.c b/monitor.c index db63223..2d4f699 100644 --- a/monitor.c +++ b/monitor.c @@ -801,9 +801,31 @@ static int get_str(char *buf, int buf_size, const char **pp) #define MAX_ARGS 16 -/* NOTE: this parser is an approximate form of the real command parser */ -static void parse_cmdline(const char *cmdline, - int *pnb_args, char **args) +static void free_cmdline_args(char **args, int nb_args) +{ + int i; + + nb_args = nb_args < MAX_ARGS ? nb_args : MAX_ARGS;Why is this needed? nb_args is guaranteed to be at most MAX_ARGS, isn't it? If you really want to ensure it, then you can assert() it.
I'll use assert().
+ for (i = 0; i < nb_args; i++) { + g_free(args[i]); + } + +} + +/* + * Parse the command line to get valid args. + * @cmdline: command line to be parsed. + * @pnb_args: location to store the number of args, must NOT be NULL. + * @args: location to store the args, which should be freed by caller, must + * NOT be NULL. + * + * Returns 0 on success, negative on failure. + * + * NOTE: this parser is an approximate form of the real command parser. Number + * of args have a limit of MAX_ARGS. + */ +static int parse_cmdline(const char *cmdline, + int *pnb_args, char **args) { const char *p; int nb_args, ret; @@ -811,24 +833,26 @@ static void parse_cmdline(const char *cmdline, p = cmdline; nb_args = 0; - for (;;) { + while (nb_args < MAX_ARGS) {I think it would be better to fail if nb_args > MAX_ARGS. Well, ideally
will fail the function if nb_args > MAX_ARGS in next version.
we shouldn't have any artificial limit, but I'd guess that dropping MAX_ARGS goes a bit to far for this series' scope.while (qemu_isspace(*p)) { p++; } if (*p == '\0') { break; } - if (nb_args >= MAX_ARGS) { - break; - } ret = get_str(buf, sizeof(buf), &p); - args[nb_args] = g_strdup(buf); - nb_args++; if (ret < 0) { - break; + goto fail; } + args[nb_args] = g_strdup(buf); + nb_args++; } *pnb_args = nb_args; + return 0; + + fail: + free_cmdline_args(args, nb_args); + return -1; } static void help_cmd_dump(Monitor *mon, const mon_cmd_t *cmds, @@ -4144,7 +4168,9 @@ static void monitor_find_completion(Monitor *mon, const mon_cmd_t *cmd; MonitorBlockComplete mbs; - parse_cmdline(cmdline, &nb_args, args); + if (parse_cmdline(cmdline, &nb_args, args) < 0) { + return; + } #ifdef DEBUG_COMPLETION for (i = 0; i < nb_args; i++) { monitor_printf(mon, "arg%d = '%s'\n", i, args[i]); @@ -4234,9 +4260,7 @@ static void monitor_find_completion(Monitor *mon, } cleanup: - for (i = 0; i < nb_args; i++) { - g_free(args[i]); - } + free_cmdline_args(args, nb_args); } static int monitor_can_read(void *opaque)
-- Best Regards Wenchao Xia
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