Re: [Qemu-devel] [PATCH 12/15] qemu-print: New qemu_printf(), qemu_vprintf() etc.

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

On 4/8/19 10:36 AM, Markus Armbruster wrote:
> We commonly want to print to the current monitor if we have one, else
> to stdout/stderr.  For stderr, have error_printf().  For stdout, all
> we have is monitor_vfprintf(), which is rather unwieldy.  We often
> print to stderr just because error_printf() is easier.
> 
> New qemu_printf() and qemu_vprintf() do exactly what's needed.  The
> next commits will put them to use.
> 
> Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
> Signed-off-by: Markus Armbruster <armbru@redhat.com>
> ---
>  MAINTAINERS               |  2 ++
>  include/qemu/qemu-print.h | 19 ++++++++++++++++++
>  stubs/monitor.c           |  5 +++++
>  util/Makefile.objs        |  1 +
>  util/qemu-print.c         | 42 +++++++++++++++++++++++++++++++++++++++
>  5 files changed, 69 insertions(+)
>  create mode 100644 include/qemu/qemu-print.h
>  create mode 100644 util/qemu-print.c
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 56139ac8ab..1aa19dc4ef 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -1895,6 +1895,8 @@ F: hmp.[ch]
>  F: hmp-commands*.hx
>  F: include/monitor/hmp-target.h
>  F: tests/test-hmp.c
> +F: include/qemu/qemu-print.h
> +F: util/qemu-print.c
>  
>  Network device backends
>  M: Jason Wang <jasowang@redhat.com>
> diff --git a/include/qemu/qemu-print.h b/include/qemu/qemu-print.h
> new file mode 100644
> index 0000000000..8fed32bf42
> --- /dev/null
> +++ b/include/qemu/qemu-print.h
> @@ -0,0 +1,19 @@
> +/*
> + * Print to stream or current monitor
> + *
> + * Copyright (C) 2019 Red Hat Inc.
> + *
> + * Authors:
> + *  Markus Armbruster <armbru@redhat.com>,
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2 or later.
> + * See the COPYING file in the top-level directory.
> + */
> +
> +#ifndef QEMU_PRINT_H
> +#define QEMU_PRINT_H
> +
> +int qemu_vprintf(const char *fmt, va_list ap) GCC_FMT_ATTR(1, 0);
> +int qemu_printf(const char *fmt, ...) GCC_FMT_ATTR(1, 2);

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>

> +
> +#endif
> diff --git a/stubs/monitor.c b/stubs/monitor.c
> index b57fe6c32f..b2ea975e40 100644
> --- a/stubs/monitor.c
> +++ b/stubs/monitor.c
> @@ -6,6 +6,11 @@
>  
>  __thread Monitor *cur_mon;
>  
> +int monitor_vprintf(Monitor *mon, const char *fmt, va_list ap)
> +{
> +    abort();
> +}
> +
>  int monitor_get_fd(Monitor *mon, const char *name, Error **errp)
>  {
>      error_setg(errp, "only QEMU supports file descriptor passing");
> diff --git a/util/Makefile.objs b/util/Makefile.objs
> index 835fcd69e2..9206878dec 100644
> --- a/util/Makefile.objs
> +++ b/util/Makefile.objs
> @@ -23,6 +23,7 @@ util-obj-y += bitmap.o bitops.o hbitmap.o
>  util-obj-y += fifo8.o
>  util-obj-y += cacheinfo.o
>  util-obj-y += error.o qemu-error.o
> +util-obj-y += qemu-print.o
>  util-obj-y += id.o
>  util-obj-y += iov.o qemu-config.o qemu-sockets.o uri.o notify.o
>  util-obj-y += qemu-option.o qemu-progress.o
> diff --git a/util/qemu-print.c b/util/qemu-print.c
> new file mode 100644
> index 0000000000..86f9417af8
> --- /dev/null
> +++ b/util/qemu-print.c
> @@ -0,0 +1,42 @@
> +/*
> + * Print to stream or current monitor
> + *
> + * Copyright (C) 2019 Red Hat Inc.
> + *
> + * Authors:
> + *  Markus Armbruster <armbru@redhat.com>,
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2 or later.
> + * See the COPYING file in the top-level directory.
> + */
> +
> +#include "qemu/osdep.h"
> +#include "monitor/monitor.h"
> +#include "qemu/qemu-print.h"
> +
> +/*
> + * Print like vprintf().
> + * Print to current monitor if we have one, else to stdout.
> + */
> +int qemu_vprintf(const char *fmt, va_list ap)
> +{
> +    if (cur_mon) {
> +        return monitor_vprintf(cur_mon, fmt, ap);
> +    }
> +    return vprintf(fmt, ap);
> +}
> +
> +/*
> + * Print like printf().
> + * Print to current monitor if we have one, else to stdout.
> + */
> +int qemu_printf(const char *fmt, ...)
> +{
> +    va_list ap;
> +    int ret;
> +
> +    va_start(ap, fmt);
> +    ret = qemu_vprintf(fmt, ap);
> +    va_end(ap);
> +    return ret;
> +}
>