Re: [Qemu-devel] [PATCH] hw/9pfs: use g_vasprintf() instead of rolling our own

["Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>]

On Mon, 31 Oct 2011 11:49:33 +0000, Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> wrote:
> Markus Armbruster <armbru@redhat.com> sent fixes for va_list vararg
> issues in v9fs_string_alloc_printf().  It turns out the function
> duplicates g_vasprintf() and can therefore be eliminated entirely.
> 
> Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>

Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>

> ---
>  hw/9pfs/virtio-9p.c |  103 ++-------------------------------------------------
>  1 files changed, 4 insertions(+), 99 deletions(-)
> 
> diff --git a/hw/9pfs/virtio-9p.c b/hw/9pfs/virtio-9p.c
> index 8b6813f..253919b 100644
> --- a/hw/9pfs/virtio-9p.c
> +++ b/hw/9pfs/virtio-9p.c
> @@ -11,6 +11,9 @@
>   *
>   */
> 
> +#include <glib.h>
> +#include <glib/gprintf.h>
> +
>  #include "hw/virtio.h"
>  #include "hw/pc.h"
>  #include "qemu_socket.h"
> @@ -161,114 +164,16 @@ void v9fs_string_null(V9fsString *str)
>      v9fs_string_free(str);
>  }
> 
> -static int number_to_string(void *arg, char type)
> -{
> -    unsigned int ret = 0;
> -
> -    switch (type) {
> -    case 'u': {
> -        unsigned int num = *(unsigned int *)arg;
> -
> -        do {
> -            ret++;
> -            num = num/10;
> -        } while (num);
> -        break;
> -    }
> -    case 'U': {
> -        unsigned long num = *(unsigned long *)arg;
> -        do {
> -            ret++;
> -            num = num/10;
> -        } while (num);
> -        break;
> -    }
> -    default:
> -        printf("Number_to_string: Unknown number format\n");
> -        return -1;
> -    }
> -
> -    return ret;
> -}
> -
> -static int GCC_FMT_ATTR(2, 0)
> -v9fs_string_alloc_printf(char **strp, const char *fmt, va_list ap)
> -{
> -    va_list ap2;
> -    char *iter = (char *)fmt;
> -    int len = 0;
> -    int nr_args = 0;
> -    char *arg_char_ptr;
> -    unsigned int arg_uint;
> -    unsigned long arg_ulong;
> -
> -    /* Find the number of %'s that denotes an argument */
> -    for (iter = strstr(iter, "%"); iter; iter = strstr(iter, "%")) {
> -        nr_args++;
> -        iter++;
> -    }
> -
> -    len = strlen(fmt) - 2*nr_args;
> -
> -    if (!nr_args) {
> -        goto alloc_print;
> -    }
> -
> -    va_copy(ap2, ap);
> -
> -    iter = (char *)fmt;
> -
> -    /* Now parse the format string */
> -    for (iter = strstr(iter, "%"); iter; iter = strstr(iter, "%")) {
> -        iter++;
> -        switch (*iter) {
> -        case 'u':
> -            arg_uint = va_arg(ap2, unsigned int);
> -            len += number_to_string((void *)&arg_uint, 'u');
> -            break;
> -        case 'l':
> -            if (*++iter == 'u') {
> -                arg_ulong = va_arg(ap2, unsigned long);
> -                len += number_to_string((void *)&arg_ulong, 'U');
> -            } else {
> -                return -1;
> -            }
> -            break;
> -        case 's':
> -            arg_char_ptr = va_arg(ap2, char *);
> -            len += strlen(arg_char_ptr);
> -            break;
> -        case 'c':
> -            len += 1;
> -            break;
> -        default:
> -            fprintf(stderr,
> -		    "v9fs_string_alloc_printf:Incorrect format %c", *iter);
> -            return -1;
> -        }
> -        iter++;
> -    }
> -
> -alloc_print:
> -    *strp = g_malloc((len + 1) * sizeof(**strp));
> -
> -    return vsprintf(*strp, fmt, ap);
> -}
> -
>  void GCC_FMT_ATTR(2, 3)
>  v9fs_string_sprintf(V9fsString *str, const char *fmt, ...)
>  {
>      va_list ap;
> -    int err;
> 
>      v9fs_string_free(str);
> 
>      va_start(ap, fmt);
> -    err = v9fs_string_alloc_printf(&str->data, fmt, ap);
> -    BUG_ON(err == -1);
> +    str->size = g_vasprintf(&str->data, fmt, ap);
>      va_end(ap);
> -
> -    str->size = err;
>  }
> 
>  void v9fs_string_copy(V9fsString *lhs, V9fsString *rhs)
> -- 
> 1.7.7
>