Re: [Qemu-devel] [PATCH v2 1/4] block: Use g_new() & friends where that makes obvious sense

[Jeff Cody <jcody@redhat.com>]

On Mon, Aug 18, 2014 at 06:10:40PM +0200, Markus Armbruster wrote:
> g_new(T, n) is neater than g_malloc(sizeof(T) * n).  It's also safer,
> for two reasons.  One, it catches multiplication overflowing size_t.
> Two, it returns T * rather than void *, which lets the compiler catch
> more type errors.
> 
> Patch created with Coccinelle, with two manual changes on top:
> 
> * Add const to bdrv_iterate_format() to keep the types straight
> 
> * Convert the allocation in bdrv_drop_intermediate(), which Coccinelle
>   inexplicably misses
> 
> Coccinelle semantic patch:
> 
>     @@
>     type T;
>     @@
>     -g_malloc(sizeof(T))
>     +g_new(T, 1)
>     @@
>     type T;
>     @@
>     -g_try_malloc(sizeof(T))
>     +g_try_new(T, 1)
>     @@
>     type T;
>     @@
>     -g_malloc0(sizeof(T))
>     +g_new0(T, 1)
>     @@
>     type T;
>     @@
>     -g_try_malloc0(sizeof(T))
>     +g_try_new0(T, 1)
>     @@
>     type T;
>     expression n;
>     @@
>     -g_malloc(sizeof(T) * (n))
>     +g_new(T, n)
>     @@
>     type T;
>     expression n;
>     @@
>     -g_try_malloc(sizeof(T) * (n))
>     +g_try_new(T, n)
>     @@
>     type T;
>     expression n;
>     @@
>     -g_malloc0(sizeof(T) * (n))
>     +g_new0(T, n)
>     @@
>     type T;
>     expression n;
>     @@
>     -g_try_malloc0(sizeof(T) * (n))
>     +g_try_new0(T, n)
>     @@
>     type T;
>     expression p, n;
>     @@
>     -g_realloc(p, sizeof(T) * (n))
>     +g_renew(T, p, n)
>     @@
>     type T;
>     expression p, n;
>     @@
>     -g_try_realloc(p, sizeof(T) * (n))
>     +g_try_renew(T, p, n)
> 
> Signed-off-by: Markus Armbruster <armbru@redhat.com>
> ---
>  block-migration.c      |  6 +++---
>  block.c                | 14 +++++++-------
>  block/archipelago.c    |  6 +++---
>  block/gluster.c        |  8 ++++----
>  block/iscsi.c          |  2 +-
>  block/nfs.c            |  2 +-
>  block/qcow.c           |  2 +-
>  block/qcow2-cluster.c  |  2 +-
>  block/qcow2-refcount.c |  8 ++++----
>  block/qcow2-snapshot.c |  8 ++++----
>  block/raw-posix.c      |  2 +-
>  block/rbd.c            |  4 ++--
>  block/sheepdog.c       |  4 ++--
>  block/vdi.c            |  2 +-
>  block/vhdx.c           |  4 ++--
>  block/vmdk.c           |  7 +++----
>  block/vvfat.c          |  2 +-
>  blockdev-nbd.c         |  2 +-
>  blockdev.c             |  2 +-
>  hw/ide/ahci.c          |  2 +-
>  qemu-io-cmds.c         |  2 +-
>  qemu-io.c              |  2 +-
>  22 files changed, 46 insertions(+), 47 deletions(-)

[...]

Reviewed-by: Jeff Cody <jcody@redhat.com>