[libvirt] [PATCH v2] glibcompat: Reimplement g_strdup_printf() and g_strdup_vprintf()

[Peter Krempa]

On Fri, Oct 18, 2019 at 11:49:05 +0200, Michal Privoznik wrote:
> These functions don't really abort() on OOM. The fix was merged
> upstream, but not in the minimal version we require. Provide our
> own implementation which can be removed once we bump the minimal
> version.
> 
> Signed-off-by: Michal Privoznik <mprivozn at redhat.com>
> ---
> 
> v2 of:
> 
> https://www.redhat.com/archives/libvir-list/2019-October/msg01153.html
> 
> diff to v1:
> - moved the code to src/utils/glibcompat.c
> 
>  src/internal.h           |  1 +
>  src/libvirt_private.syms |  5 +++++
>  src/util/Makefile.inc.am |  2 ++
>  src/util/glibcompat.c    | 48 ++++++++++++++++++++++++++++++++++++++++
>  src/util/glibcompat.h    | 31 ++++++++++++++++++++++++++
>  5 files changed, 87 insertions(+)
>  create mode 100644 src/util/glibcompat.c
>  create mode 100644 src/util/glibcompat.h
> 
> diff --git a/src/internal.h b/src/internal.h
> index fb17b87baa..5b0a2335f5 100644
> --- a/src/internal.h
> +++ b/src/internal.h
> @@ -64,6 +64,7 @@
>  #include "libvirt/virterror.h"
>  
>  #include "c-strcase.h"
> +#include "glibcompat.h"

Please include this right below glib.h

>  
>  /* Merely casting to (void) is not sufficient since the
>   * introduction of the "warn_unused_result" attribute

[...]

> diff --git a/src/util/glibcompat.c b/src/util/glibcompat.c
> new file mode 100644
> index 0000000000..af638f4d8c
> --- /dev/null
> +++ b/src/util/glibcompat.c
> @@ -0,0 +1,48 @@
> +/*
> + * Copyright (C) 2019 Red Hat, Inc.
> + *
> + * This library is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU Lesser General Public
> + * License as published by the Free Software Foundation; either
> + * version 2.1 of the License, or (at your option) any later version.
> + *
> + * This library is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> + * Lesser General Public License for more details.
> + *
> + * You should have received a copy of the GNU Lesser General Public
> + * License along with this library.  If not, see
> + * <http://www.gnu.org/licenses/>.
> + */
> +
> +#include <config.h>
> +
> +#include "glibcompat.h"

Sooo, this includes the macros ...

> +
> +/* Due to a bug in glib, g_strdup_printf() nor g_strdup_vprintf()
> + * abort on OOM.  It's fixed in glib's upstream. Provide our own
> + * implementation until the fix get's distributed. */
> +char *
> +vir_g_strdup_printf(const char *msg, ...)
> +{
> +  va_list args;
> +  char *ret;
> +  va_start(args, msg);
> +  ret = g_strdup_vprintf(msg, args);
> +  if (!ret)
> +    abort();
> +  va_end(args);
> +  return ret;
> +}
> +
> +
> +char *
> +vir_g_strdup_vprintf(const char *msg, va_list args)
> +{
> +  char *ret;
> +  ret = g_strdup_vprintf(msg, args);

So this will become vir_g_strdup_vprintf.. thus become infinite
recursion.

> +  if (!ret)
> +    abort();
> +  return ret;
> +}

I think the kludge header must be separate and not included into this
implementation, otherwise it will not work as expected.


> diff --git a/src/util/glibcompat.h b/src/util/glibcompat.h
> new file mode 100644
> index 0000000000..9c5fef09bf
> --- /dev/null
> +++ b/src/util/glibcompat.h
> @@ -0,0 +1,31 @@
> +/*
> + * Copyright (C) 2019 Red Hat, Inc.
> + *
> + * This library is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU Lesser General Public
> + * License as published by the Free Software Foundation; either
> + * version 2.1 of the License, or (at your option) any later version.
> + *
> + * This library is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> + * Lesser General Public License for more details.
> + *
> + * You should have received a copy of the GNU Lesser General Public
> + * License along with this library.  If not, see
> + * <http://www.gnu.org/licenses/>.
> + */
> +
> +#pragma once
> +
> +#include <glib.h>
> +
> +char *vir_g_strdup_printf(const char *msg, ...)
> +    G_GNUC_PRINTF(1, 2);
> +char *vir_g_strdup_vprintf(const char *msg, va_list args)
> +    G_GNUC_PRINTF(1, 0);
> +
> +#if !GLIB_CHECK_VERSION(2, 64, 0)
> +# define g_strdup_printf vir_g_strdup_printf
> +# define g_strdup_vprintf vir_g_strdup_vprintf
> +#endif
> -- 
> 2.21.0
> 
> --
> libvir-list mailing list
> libvir-list at redhat.com
> https://www.redhat.com/mailman/listinfo/libvir-list