Re: [PATCH v2 31/39] util: guard monitor_vprintf callers with CONFIG_HMP

["Daniel P. Berrangé" <berrange@redhat.com>]

On Fri, Jun 26, 2026 at 01:19:32AM +0400, Marc-André Lureau wrote:
> Guard calls to monitor_vprintf in error-report and qemu-print so
> they compile without HMP. When CONFIG_HMP is not set,
> error_vprintf_mon falls back directly to stderr and qemu_vfprintf
> returns -1 for NULL streams.
> 
> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> ---
>  tests/unit/test-util-sockets.c | 4 +++-
>  tools/qemu-vnc/stubs.c         | 2 ++
>  util/error-report.c            | 8 +++++---
>  util/qemu-print.c              | 6 ++++++
>  4 files changed, 16 insertions(+), 4 deletions(-)

This patch probably isn't required any more.

With the QOM classes for montior,  monitor_vprintf calls to a 'vprintf'
class virtual method, or returns -1.

So simply by virtue of HMP being compiled out, monitor_vprintf should
do the right thing.

> 
> diff --git a/tests/unit/test-util-sockets.c b/tests/unit/test-util-sockets.c
> index b9f2453e299..23ebe1e26b5 100644
> --- a/tests/unit/test-util-sockets.c
> +++ b/tests/unit/test-util-sockets.c
> @@ -73,8 +73,10 @@ int monitor_get_fd(Monitor *mon, const char *fdname, Error **errp)
>   */
>  Monitor *monitor_cur(void) { return cur_mon; }
>  Monitor *monitor_set_cur(Coroutine *co, Monitor *mon) { abort(); }
> -int monitor_vprintf(Monitor *mon, const char *fmt, va_list ap) { abort(); }
>  bool monitor_cur_is_qmp(void) { abort(); };
> +#ifdef CONFIG_HMP
> +int monitor_vprintf(Monitor *mon, const char *fmt, va_list ap) { abort(); }
> +#endif
>  
>  #ifndef _WIN32
>  static void test_socket_fd_pass_name_good(void)
> diff --git a/tools/qemu-vnc/stubs.c b/tools/qemu-vnc/stubs.c
> index a865ce85f04..f476dd6d956 100644
> --- a/tools/qemu-vnc/stubs.c
> +++ b/tools/qemu-vnc/stubs.c
> @@ -46,10 +46,12 @@ Monitor *monitor_set_cur(Coroutine *co, Monitor *mon)
>      return NULL;
>  }
>  
> +#ifdef CONFIG_HMP
>  int monitor_vprintf(Monitor *mon, const char *fmt, va_list ap)
>  {
>      return -1;
>  }
> +#endif
>  
>  /*
>   * Link-time stubs for VMState symbols referenced by VNC code.
> diff --git a/util/error-report.c b/util/error-report.c
> index f832ad9b6b6..e2e46281455 100644
> --- a/util/error-report.c
> +++ b/util/error-report.c
> @@ -40,11 +40,13 @@ error_vprintf_mon(Monitor *cur_mon, const char *fmt, va_list ap)
>       * IOW this will only print if in HMP, otherwise we
>       * fallback to stderr for QMP / no-monitor scenarios.
>       */
> +#ifdef CONFIG_HMP
>      int ret = monitor_vprintf(cur_mon, fmt, ap);
> -    if (ret == -1) {
> -        ret = vfprintf(stderr, fmt, ap);
> +    if (ret != -1) {
> +        return ret;
>      }
> -    return ret;
> +#endif
> +    return vfprintf(stderr, fmt, ap);
>  }
>  
>  /*
> diff --git a/util/qemu-print.c b/util/qemu-print.c
> index 7b9591035e5..ee80000722b 100644
> --- a/util/qemu-print.c
> +++ b/util/qemu-print.c
> @@ -20,10 +20,12 @@
>   */
>  int qemu_vprintf(const char *fmt, va_list ap)
>  {
> +#ifdef CONFIG_HMP
>      Monitor *cur_mon = monitor_cur();
>      if (cur_mon) {
>          return monitor_vprintf(cur_mon, fmt, ap);
>      }
> +#endif
>      return vprintf(fmt, ap);
>  }
>  
> @@ -52,7 +54,11 @@ int qemu_printf(const char *fmt, ...)
>  int qemu_vfprintf(FILE *stream, const char *fmt, va_list ap)
>  {
>      if (!stream) {
> +#ifdef CONFIG_HMP
>          return monitor_vprintf(monitor_cur(), fmt, ap);
> +#else
> +        return -1;
> +#endif
>      }
>      return vfprintf(stream, fmt, ap);
>  }
> 
> -- 
> 2.54.0
> 

With regards,
Daniel
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