[Qemu-devel] [PATCH v2] monitor: print the invalid char in error message

[Qemu-devel] [PATCH v2] monitor: print the invalid char in error message

[Fam Zheng]

It's more friendly to print which char is invalid to user, especially
when user tries to input a float value and expect the monitor to round
it to int. Since we don't round float number when we look for a integer,
telling which char is invalid is less confusing.

Signed-off-by: Fam Zheng <famz@redhat.com>
---
 monitor.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/monitor.c b/monitor.c
index 5dc0aa9..da9c9a2 100644
--- a/monitor.c
+++ b/monitor.c
@@ -3171,9 +3171,13 @@ static const MonitorDef monitor_defs[] = {
     { NULL },
 };
 
-static void expr_error(Monitor *mon, const char *msg)
+static void expr_error(Monitor *mon, const char *fmt, ...)
 {
-    monitor_printf(mon, "%s\n", msg);
+    va_list ap;
+    va_start(ap, fmt);
+    monitor_vprintf(mon, fmt, ap);
+    monitor_printf(mon, "\n");
+    va_end(ap);
     siglongjmp(expr_env, 1);
 }
 
@@ -3291,7 +3295,7 @@ static int64_t expr_unary(Monitor *mon)
             expr_error(mon, "number too large");
         }
         if (pch == p) {
-            expr_error(mon, "invalid char in expression");
+            expr_error(mon, "invalid char '%c' in expression", *p);
         }
         pch = p;
         while (qemu_isspace(*pch))
-- 
1.8.3.1

Re: [Qemu-devel] [PATCH v2] monitor: print the invalid char in error message

[Markus Armbruster]

Fam Zheng <famz@redhat.com> writes:

> It's more friendly to print which char is invalid to user, especially
> when user tries to input a float value and expect the monitor to round
> it to int. Since we don't round float number when we look for a integer,
> telling which char is invalid is less confusing.
>
> Signed-off-by: Fam Zheng <famz@redhat.com>
> ---
>  monitor.c | 10 +++++++---
>  1 file changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/monitor.c b/monitor.c
> index 5dc0aa9..da9c9a2 100644
> --- a/monitor.c
> +++ b/monitor.c
> @@ -3171,9 +3171,13 @@ static const MonitorDef monitor_defs[] = {
>      { NULL },
>  };
>  
> -static void expr_error(Monitor *mon, const char *msg)
> +static void expr_error(Monitor *mon, const char *fmt, ...)
>  {
> -    monitor_printf(mon, "%s\n", msg);
> +    va_list ap;
> +    va_start(ap, fmt);
> +    monitor_vprintf(mon, fmt, ap);
> +    monitor_printf(mon, "\n");
> +    va_end(ap);
>      siglongjmp(expr_env, 1);
>  }
>  
> @@ -3291,7 +3295,7 @@ static int64_t expr_unary(Monitor *mon)
>              expr_error(mon, "number too large");
>          }
>          if (pch == p) {
> -            expr_error(mon, "invalid char in expression");
> +            expr_error(mon, "invalid char '%c' in expression", *p);
>          }
>          pch = p;
>          while (qemu_isspace(*pch))

The user is still left guessing *where* the error is.  But it's an
incremental improvement.

Reviewed-by: Markus Armbruster <armbru@redhat.com>

Re: [Qemu-devel] [PATCH v2] monitor: print the invalid char in error message

[Eric Blake]

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On 08/19/2013 08:58 PM, Fam Zheng wrote:
> It's more friendly to print which char is invalid to user, especially
> when user tries to input a float value and expect the monitor to round
> it to int. Since we don't round float number when we look for a integer,
> telling which char is invalid is less confusing.

Including a sample of the error message issued before and after this
patch as part of the commit message is helpful, but not enough for me to
require a respin.

> 
> Signed-off-by: Fam Zheng <famz@redhat.com>
> ---
>  monitor.c | 10 +++++++---
>  1 file changed, 7 insertions(+), 3 deletions(-)

Reviewed-by: Eric Blake <eblake@redhat.com>

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org


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Re: [Qemu-devel] [PATCH v2] monitor: print the invalid char in error message

[Luiz Capitulino]

On Tue, 20 Aug 2013 10:58:21 +0800
Fam Zheng <famz@redhat.com> wrote:

> It's more friendly to print which char is invalid to user, especially
> when user tries to input a float value and expect the monitor to round
> it to int. Since we don't round float number when we look for a integer,
> telling which char is invalid is less confusing.
> 
> Signed-off-by: Fam Zheng <famz@redhat.com>

Applied to the qmp branch, thanks.

> ---
>  monitor.c | 10 +++++++---
>  1 file changed, 7 insertions(+), 3 deletions(-)
> 
> diff --git a/monitor.c b/monitor.c
> index 5dc0aa9..da9c9a2 100644
> --- a/monitor.c
> +++ b/monitor.c
> @@ -3171,9 +3171,13 @@ static const MonitorDef monitor_defs[] = {
>      { NULL },
>  };
>  
> -static void expr_error(Monitor *mon, const char *msg)
> +static void expr_error(Monitor *mon, const char *fmt, ...)
>  {
> -    monitor_printf(mon, "%s\n", msg);
> +    va_list ap;
> +    va_start(ap, fmt);
> +    monitor_vprintf(mon, fmt, ap);
> +    monitor_printf(mon, "\n");
> +    va_end(ap);
>      siglongjmp(expr_env, 1);
>  }
>  
> @@ -3291,7 +3295,7 @@ static int64_t expr_unary(Monitor *mon)
>              expr_error(mon, "number too large");
>          }
>          if (pch == p) {
> -            expr_error(mon, "invalid char in expression");
> +            expr_error(mon, "invalid char '%c' in expression", *p);
>          }
>          pch = p;
>          while (qemu_isspace(*pch))