Message ID | 1373512429-17865-9-git-send-email-xiawenc@linux.vnet.ibm.com |
---|---|
State | New |
Headers | show |
On Thu, 11 Jul 2013 11:13:44 +0800 Wenchao Xia <xiawenc@linux.vnet.ibm.com> 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 <xiawenc@linux.vnet.ibm.com> > --- > 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. > + 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 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)
δΊ 2013-7-18 3:39, Luiz Capitulino ει: > On Thu, 11 Jul 2013 11:13:44 +0800 > Wenchao Xia <xiawenc@linux.vnet.ibm.com> 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 <xiawenc@linux.vnet.ibm.com> >> --- >> 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) >
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; + 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) { 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)
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 <xiawenc@linux.vnet.ibm.com> --- monitor.c | 52 ++++++++++++++++++++++++++++++++++++++-------------- 1 files changed, 38 insertions(+), 14 deletions(-)