[PATCH] storage-daemon: include current command line option in the errors

[PATCH] storage-daemon: include current command line option in the errors

[Paolo Bonzini]

Use the location management facilities that the emulator uses, so that
the current command line option appears in the error message.

Before:

  $ storage-daemon/qemu-storage-daemon --nbd key..=
  qemu-storage-daemon: Invalid parameter 'key..'

After:

  $ storage-daemon/qemu-storage-daemon --nbd key..=
  qemu-storage-daemon: --nbd key..=: Invalid parameter 'key..'

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 storage-daemon/qemu-storage-daemon.c | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/storage-daemon/qemu-storage-daemon.c b/storage-daemon/qemu-storage-daemon.c
index 9021a46b3a..a8f8d83f6f 100644
--- a/storage-daemon/qemu-storage-daemon.c
+++ b/storage-daemon/qemu-storage-daemon.c
@@ -152,6 +152,20 @@ static void init_qmp_commands(void)
                          qmp_marshal_qmp_capabilities, QCO_ALLOW_PRECONFIG);
 }
 
+static int getopt_set_loc(int argc, char **argv, const char *optstring,
+                          const struct option *longopts)
+{
+    int c, save_index;
+
+    optarg = NULL;
+    save_index = optind;
+    c = getopt_long(argc, argv, optstring, longopts, NULL);
+    if (optarg) {
+        loc_set_cmdline(argv, save_index, MAX(1, optind - save_index));
+    }
+    return c;
+}
+
 static void process_options(int argc, char *argv[])
 {
     int c;
@@ -174,7 +188,7 @@ static void process_options(int argc, char *argv[])
      * they are given on the command lines. This means that things must be
      * defined first before they can be referenced in another option.
      */
-    while ((c = getopt_long(argc, argv, "hT:V", long_options, NULL)) != -1) {
+    while ((c = getopt_set_loc(argc, argv, "hT:V", long_options)) != -1) {
         switch (c) {
         case '?':
             exit(EXIT_FAILURE);
@@ -283,6 +297,7 @@ static void process_options(int argc, char *argv[])
         error_report("Unexpected argument: %s", argv[optind]);
         exit(EXIT_FAILURE);
     }
+    loc_set_none();
 }
 
 int main(int argc, char *argv[])
-- 
2.26.2

Re: [PATCH] storage-daemon: include current command line option in the errors

[Eric Blake]

On 2/26/21 5:03 AM, Paolo Bonzini wrote:
> Use the location management facilities that the emulator uses, so that
> the current command line option appears in the error message.
> 
> Before:
> 
>   $ storage-daemon/qemu-storage-daemon --nbd key..=
>   qemu-storage-daemon: Invalid parameter 'key..'
> 
> After:
> 
>   $ storage-daemon/qemu-storage-daemon --nbd key..=
>   qemu-storage-daemon: --nbd key..=: Invalid parameter 'key..'
> 
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
>  storage-daemon/qemu-storage-daemon.c | 17 ++++++++++++++++-
>  1 file changed, 16 insertions(+), 1 deletion(-)
> 

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

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3226
Virtualization:  qemu.org | libvirt.org

Re: [PATCH] storage-daemon: include current command line option in the errors

[Kevin Wolf]

Am 26.02.2021 um 12:03 hat Paolo Bonzini geschrieben:
> Use the location management facilities that the emulator uses, so that
> the current command line option appears in the error message.
> 
> Before:
> 
>   $ storage-daemon/qemu-storage-daemon --nbd key..=
>   qemu-storage-daemon: Invalid parameter 'key..'
> 
> After:
> 
>   $ storage-daemon/qemu-storage-daemon --nbd key..=
>   qemu-storage-daemon: --nbd key..=: Invalid parameter 'key..'
> 
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
>  storage-daemon/qemu-storage-daemon.c | 17 ++++++++++++++++-
>  1 file changed, 16 insertions(+), 1 deletion(-)
> 
> diff --git a/storage-daemon/qemu-storage-daemon.c b/storage-daemon/qemu-storage-daemon.c
> index 9021a46b3a..a8f8d83f6f 100644
> --- a/storage-daemon/qemu-storage-daemon.c
> +++ b/storage-daemon/qemu-storage-daemon.c
> @@ -152,6 +152,20 @@ static void init_qmp_commands(void)
>                           qmp_marshal_qmp_capabilities, QCO_ALLOW_PRECONFIG);
>  }
>  
> +static int getopt_set_loc(int argc, char **argv, const char *optstring,
> +                          const struct option *longopts)
> +{
> +    int c, save_index;
> +
> +    optarg = NULL;
> +    save_index = optind;
> +    c = getopt_long(argc, argv, optstring, longopts, NULL);
> +    if (optarg) {
> +        loc_set_cmdline(argv, save_index, MAX(1, optind - save_index));

This save_index approach isn't perfect because getopt may skip
non-option arguments and they will be included in the help text:

    $ build/storage-daemon/qemu-storage-daemon foo --object iothread
    qemu-storage-daemon: foo --object iothread: Parameter 'id' is missing

    $ build/storage-daemon/qemu-storage-daemon foo --object iothread,id=t
    qemu-storage-daemon: --object iothread,id=t foo: Unexpected argument: foo

However, without changing the interface of loc_set_cmdline(), getting
the right index seems hard. Not sure what is the best way for fixing
this or if it's worth the effort.

Kevin

> +    }
> +    return c;
> +}
> +
>  static void process_options(int argc, char *argv[])
>  {
>      int c;
> @@ -174,7 +188,7 @@ static void process_options(int argc, char *argv[])
>       * they are given on the command lines. This means that things must be
>       * defined first before they can be referenced in another option.
>       */
> -    while ((c = getopt_long(argc, argv, "hT:V", long_options, NULL)) != -1) {
> +    while ((c = getopt_set_loc(argc, argv, "hT:V", long_options)) != -1) {
>          switch (c) {
>          case '?':
>              exit(EXIT_FAILURE);
> @@ -283,6 +297,7 @@ static void process_options(int argc, char *argv[])
>          error_report("Unexpected argument: %s", argv[optind]);
>          exit(EXIT_FAILURE);
>      }
> +    loc_set_none();
>  }
>  
>  int main(int argc, char *argv[])
> -- 
> 2.26.2
> 

Re: [PATCH] storage-daemon: include current command line option in the errors

[Paolo Bonzini]

On 01/03/21 13:26, Kevin Wolf wrote:
> This save_index approach isn't perfect because getopt may skip
> non-option arguments and they will be included in the help text:
> 
>      $ build/storage-daemon/qemu-storage-daemon foo --object iothread
>      qemu-storage-daemon: foo --object iothread: Parameter 'id' is missing
> 
>      $ build/storage-daemon/qemu-storage-daemon foo --object iothread,id=t
>      qemu-storage-daemon: --object iothread,id=t foo: Unexpected argument: foo
> 
> However, without changing the interface of loc_set_cmdline(), getting
> the right index seems hard. Not sure what is the best way for fixing
> this or if it's worth the effort.

We can do better by passing "-hT:V" to getopt_long.  Then each 
non-option argument is returned directly, and everything works as 
getopt_long no longer needs to reorder argv.

Paolo