[PATCH 10/15] cmd: blk_common: Use macros for the return values

[Simon Glass]

Hi Bin,

On Tue, 10 Oct 2023 at 03:06, Bin Meng <bmeng.cn at gmail.com> wrote:
>
> Hi Simon,
>
> On Mon, Oct 2, 2023 at 9:42 AM Simon Glass <sjg at chromium.org> wrote:
> >
> > Hi Bin,
> >
> > On Tue, 26 Sept 2023 at 02:54, Bin Meng <bmeng at tinylab.org> wrote:
> > >
> > > Avoid using magic number 0/1 for the command result.
> > >
> > > Signed-off-by: Bin Meng <bmeng at tinylab.org>
> > > ---
> > >
> > >  cmd/blk_common.c | 14 +++++++-------
> > >  1 file changed, 7 insertions(+), 7 deletions(-)
> > >
> > > diff --git a/cmd/blk_common.c b/cmd/blk_common.c
> > > index 9f9d4327a9..ad9b16dc09 100644
> > > --- a/cmd/blk_common.c
> > > +++ b/cmd/blk_common.c
> > > @@ -25,18 +25,18 @@ int blk_common_cmd(int argc, char *const argv[],
enum uclass_id uclass_id,
> > >         case 2:
> > >                 if (strncmp(argv[1], "inf", 3) == 0) {
> > >                         blk_list_devices(uclass_id);
> > > -                       return 0;
> > > +                       return CMD_RET_SUCCESS;
> >
> > I really don't like this...0 is success.
> >
> > >                 } else if (strncmp(argv[1], "dev", 3) == 0) {
> > >                         if (blk_print_device_num(uclass_id,
*cur_devnump)) {
> > >                                 printf("\nno %s devices available\n",
if_name);
> > >                                 return CMD_RET_FAILURE;
> > >                         }
> > > -                       return 0;
> > > +                       return CMD_RET_SUCCESS;
> > >                 } else if (strncmp(argv[1], "part", 4) == 0) {
> > >                         if (blk_list_part(uclass_id))
> > >                                 printf("\nno %s partition table
available\n",
> > >                                        if_name);
> > > -                       return 0;
> > > +                       return CMD_RET_SUCCESS;
> > >                 }
> > >                 return CMD_RET_USAGE;
> > >         case 3:
> > > @@ -49,7 +49,7 @@ int blk_common_cmd(int argc, char *const argv[],
enum uclass_id uclass_id,
> > >                         } else {
> > >                                 return CMD_RET_FAILURE;
> > >                         }
> > > -                       return 0;
> > > +                       return CMD_RET_SUCCESS;
> > >                 } else if (strncmp(argv[1], "part", 4) == 0) {
> > >                         int dev = (int)dectoul(argv[2], NULL);
> > >
> > > @@ -58,7 +58,7 @@ int blk_common_cmd(int argc, char *const argv[],
enum uclass_id uclass_id,
> > >                                        if_name, dev);
> > >                                 return CMD_RET_FAILURE;
> > >                         }
> > > -                       return 0;
> > > +                       return CMD_RET_SUCCESS;
> > >                 }
> > >                 return CMD_RET_USAGE;
> > >
> > > @@ -80,7 +80,7 @@ int blk_common_cmd(int argc, char *const argv[],
enum uclass_id uclass_id,
> > >
> > >                         printf("%ld blocks read: %s\n", n,
> > >                                n == cnt ? "OK" : "ERROR");
> > > -                       return n == cnt ? 0 : 1;
> > > +                       return n == cnt ? CMD_RET_SUCCESS :
CMD_RET_FAILURE;
> >
> > CMD_RET_FAILURE is OK, but I would prefer not to use CMD_RET_SUCCESS.
> > It is 0 and always will be.
> >
> > It encourages people to do things like:
> >
> > if (ret == CMD_RET_SUCCESS)
> >
> > instead of
> >
> > if (!ret)
>
> I see your concern. However we don't change the return value type to
> enum, so people can still use
>
>     if (!ret)
>
> I would still defend that we should use CMD_RET_SUCCESS.
>
> This is like EXIT_XXX defined in stdlib.h:
>
> #define   EXIT_FAILURE   1    /* Failing exit status.  */
> #define   EXIT_SUCCESS   0    /* Successful exit status.  */
>
> One should use predefined macros whenever possible.

I agree except for success, where I don't, sorry. It should always be 0 in
U-Boot.

People then have to look up the value and also we get things like

if (ret != CMD_RET_SUCCESS)

It is a slippery and I would rather not start down it.

>
> >
> > It would eventually creep into everything, including our clean error
handling.
> >
> > >                 } else if (strcmp(argv[1], "write") == 0) {
> > >                         phys_addr_t paddr = hextoul(argv[2], NULL);
> > >                         lbaint_t blk = hextoul(argv[3], NULL);
> > > @@ -98,7 +98,7 @@ int blk_common_cmd(int argc, char *const argv[],
enum uclass_id uclass_id,
> > >
> > >                         printf("%ld blocks written: %s\n", n,
> > >                                n == cnt ? "OK" : "ERROR");
> > > -                       return n == cnt ? 0 : 1;
> > > +                       return n == cnt ? CMD_RET_SUCCESS :
CMD_RET_FAILURE;
> > >                 } else {
> > >                         return CMD_RET_USAGE;
> > >                 }
> > > --

Regards,