Re: [PATCH v2 1/2] xen/char: console: Use const whenever we point to literal strings

[Jan Beulich]

On 18.05.2021 16:01, Julien Grall wrote:
> From: Julien Grall 
> 
> Literal strings are not meant to be modified. So we should use const
> char * rather than char * when we want to store a pointer to them.
> 
> The array should also not be modified at all and is only used by
> xenlog_update_val(). So take the opportunity to add an extra const and
> move the definition in the function.
> 
> Signed-off-by: Julien Grall 

Reviewed-by: Jan Beulich 

Re: [PATCH v2 1/2] xen/char: console: Use const whenever we point to literal strings

[Luca Fancellu]

> On 18 May 2021, at 15:01, Julien Grall  wrote:
> 
> From: Julien Grall 
> 
> Literal strings are not meant to be modified. So we should use const
> char * rather than char * when we want to store a pointer to them.
> 
> The array should also not be modified at all and is only used by
> xenlog_update_val(). So take the opportunity to add an extra const and
> move the definition in the function.
> 
> Signed-off-by: Julien Grall 
> 
> ---
>Changes in v2:
>- The array content should never be modified
>- Move lvl2opt in xenlog_update_val()
> ---
> xen/drivers/char/console.c | 7 ---
> 1 file changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/xen/drivers/char/console.c b/xen/drivers/char/console.c
> index 23583751709c..7d0a603d0311 100644
> --- a/xen/drivers/char/console.c
> +++ b/xen/drivers/char/console.c
> @@ -168,10 +168,11 @@ static int parse_guest_loglvl(const char *s);
> static char xenlog_val[LOGLVL_VAL_SZ];
> static char xenlog_guest_val[LOGLVL_VAL_SZ];
> 
> -static char *lvl2opt[] = { "none", "error", "warning", "info", "all" };
> -
> static void xenlog_update_val(int lower, int upper, char *val)
> {
> +static const char * const lvl2opt[] =
> +{ "none", "error", "warning", "info", "all" };
> +
> snprintf(val, LOGLVL_VAL_SZ, "%s/%s", lvl2opt[lower], lvl2opt[upper]);
> }
> 
> @@ -262,7 +263,7 @@ static int parse_guest_loglvl(const char *s)
> return ret;
> }
> 
> -static char *loglvl_str(int lvl)
> +static const char *loglvl_str(int lvl)
> {
> switch ( lvl )
> {
> -- 
> 2.17.1
> 

Hi Julien,

Seems good to me and very sensible.

Reviewed-by: Luca Fancellu 

Cheers,
Luca

[PATCH v2 1/2] xen/char: console: Use const whenever we point to literal strings

[Julien Grall]

From: Julien Grall 

Literal strings are not meant to be modified. So we should use const
char * rather than char * when we want to store a pointer to them.

The array should also not be modified at all and is only used by
xenlog_update_val(). So take the opportunity to add an extra const and
move the definition in the function.

Signed-off-by: Julien Grall 

---
Changes in v2:
- The array content should never be modified
- Move lvl2opt in xenlog_update_val()
---
 xen/drivers/char/console.c | 7 ---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/xen/drivers/char/console.c b/xen/drivers/char/console.c
index 23583751709c..7d0a603d0311 100644
--- a/xen/drivers/char/console.c
+++ b/xen/drivers/char/console.c
@@ -168,10 +168,11 @@ static int parse_guest_loglvl(const char *s);
 static char xenlog_val[LOGLVL_VAL_SZ];
 static char xenlog_guest_val[LOGLVL_VAL_SZ];
 
-static char *lvl2opt[] = { "none", "error", "warning", "info", "all" };
-
 static void xenlog_update_val(int lower, int upper, char *val)
 {
+static const char * const lvl2opt[] =
+{ "none", "error", "warning", "info", "all" };
+
 snprintf(val, LOGLVL_VAL_SZ, "%s/%s", lvl2opt[lower], lvl2opt[upper]);
 }
 
@@ -262,7 +263,7 @@ static int parse_guest_loglvl(const char *s)
 return ret;
 }
 
-static char *loglvl_str(int lvl)
+static const char *loglvl_str(int lvl)
 {
 switch ( lvl )
 {
-- 
2.17.1