From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53634) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fIeQO-0006mI-3M for qemu-devel@nongnu.org; Tue, 15 May 2018 14:11:49 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fIeQJ-0004Xr-PX for qemu-devel@nongnu.org; Tue, 15 May 2018 14:11:48 -0400 References: <20180515134950.3755-1-muriloo@linux.ibm.com> From: Eric Blake Message-ID: <7abb9c3c-524d-16cb-4bbd-7a27c5c6e676@redhat.com> Date: Tue, 15 May 2018 13:11:39 -0500 MIME-Version: 1.0 In-Reply-To: <20180515134950.3755-1-muriloo@linux.ibm.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH] HACKING: document preference for g_new instead of g_malloc List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Murilo Opsfelder Araujo , qemu-devel@nongnu.org Cc: Markus Armbruster , David Hildenbrand , Eduardo Habkost , Paolo Bonzini , qemu-trivial adding qemu-trivial as a potential tree for this to go through On 05/15/2018 08:49 AM, Murilo Opsfelder Araujo wrote: > This patch documents the preference for g_new instead of g_malloc. The > reasons were adapted from commit b45c03f585ea9bb1af76c73e82195418c294919d. > > Discussion in QEMU's mailing list: > http://lists.nongnu.org/archive/html/qemu-devel/2018-05/msg03238.html > > Cc: qemu-devel@nongnu.org > Cc: David Hildenbrand > Cc: Eduardo Habkost > Cc: Markus Armbruster > Cc: Paolo Bonzini > Signed-off-by: Murilo Opsfelder Araujo > --- > HACKING | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/HACKING b/HACKING > index 4125c97d8d..0fc3e0fc04 100644 > --- a/HACKING > +++ b/HACKING > @@ -118,6 +118,15 @@ Please note that g_malloc will exit on allocation failure, so there > is no need to test for failure (as you would have to with malloc). > Calling g_malloc with a zero size is valid and will return NULL. > > +Prefer g_new(T, n) instead of g_malloc(sizeof(T) * n) for the following > +reasons: > + > + a. It catches multiplication overflowing size_t; > + b. It returns T * instead of void *, letting compiler catch more type > + errors. > + > +Declarations like T *v = g_malloc(sizeof(*v)) are acceptable, though. > + > Memory allocated by qemu_memalign or qemu_blockalign must be freed with > qemu_vfree, since breaking this will cause problems on Win32. > > -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3266 Virtualization: qemu.org | libvirt.org