Re: [Qemu-devel] [PATCH 02/27] libvhost-user: drop dependency on glib

[Philippe Mathieu-Daudé]

On 09/12/2017 10:13 AM, Marc-André Lureau wrote:
> Hi
>
> ----- Original Message -----
> > Hi Marc-André,
> >
> > On 08/23/2017 01:19 PM, Marc-André Lureau wrote:
> > > libvhost-user is meant to be free of glib dependency. Make sure it is
> > > by droping qemu/osdep.h (which included glib.h)
> > >
> > > This fixes a bad malloc()/g_free() pair.
> > >
> > > Signed-off-by: Marc-André Lureau <address@hidden>
> > > ---
> > >    contrib/libvhost-user/libvhost-user.c | 25 ++++++++++++++++++++++---
> > >    1 file changed, 22 insertions(+), 3 deletions(-)
> > >
> > > diff --git a/contrib/libvhost-user/libvhost-user.c
> > > b/contrib/libvhost-user/libvhost-user.c
> > > index 35fa0c5e56..bb294c6ef7 100644
> > > --- a/contrib/libvhost-user/libvhost-user.c
> > > +++ b/contrib/libvhost-user/libvhost-user.c
> > > @@ -13,11 +13,22 @@
> > >     * later.  See the COPYING file in the top-level directory.
> > >     */
> > >    

/* this code avoids GLib dependency */

> > > -#include <qemu/osdep.h>
> > > +#include <stdlib.h>
> > > +#include <stdio.h>
> > > +#include <unistd.h>
> > > +#include <stdarg.h>
> > > +#include <errno.h>
> > > +#include <string.h>
> > > +#include <assert.h>
> > > +#include <inttypes.h>
> > > +#include <sys/types.h>
> > > +#include <sys/socket.h>
> > >    #include <sys/eventfd.h>
> > > +#include <sys/mman.h>
> > >    #include <linux/vhost.h>
> > >    
> > >    #include "qemu/atomic.h"
> > > +#include "qemu/compiler.h"
> > >    
> > >    #include "libvhost-user.h"
> > >    
> > > @@ -34,6 +45,14 @@
> > >            }                                       \
> > >        } while (0)
> > >    
> > > +#ifndef MIN

/* usually provided by GLib */

> > > +#define MIN(x, y) ({                            \
> > > +        typeof(x) _min1 = (x);                  \
> > > +        typeof(y) _min2 = (y);                  \
> > > +        (void) (&_min1 == &_min2);              \
> > > +        _min1 < _min2 ? _min1 : _min2; })
> >
> > why not add this in qemu/compiler.h instead?
>
> It's a special case here, because libvhost-user doesn't depend on glib. The 
> rest of qemu does. Since MIN/MAX is defined by glib, I don't think 
> qemu/compiler.h should define it.

OK, with some comments about GLib Independence:

Reviewed-by: Philippe Mathieu-Daudé <address@hidden>

> > > +#endif
> > > +
> > >    static const char *
> > >    vu_request_to_string(int req)
> > >    {
> > > @@ -81,7 +100,7 @@ vu_panic(VuDev *dev, const char *msg, ...)
> > >        va_list ap;
> > >    
> > >        va_start(ap, msg);
> > > -    buf = g_strdup_vprintf(msg, ap);
> > > +    vasprintf(&buf, msg, ap);
> > >        va_end(ap);
> > >    
> > >        dev->broken = true;
> > > @@ -840,7 +859,7 @@ vu_dispatch(VuDev *dev)
> > >        success = true;
> > >    
> > >    end:
> > > -    g_free(vmsg.data);
> > > +    free(vmsg.data);
> > >        return success;
> > >    }
> > >