[Qemu-devel] [PATCH] qemu-pr-helper: Do not use {0} for initialization

[Qemu-devel] [PATCH] qemu-pr-helper: Do not use {0} for initialization

[Paolo Bonzini]

The first field in struct dm_ioctl is an array, and old GCC warns
about it with -Wmissing-braces (GCC <= 4.8).  The "{0}" universal
zero initializer is only useful if the other side might be a scalar;
for a struct, "{}" is enough and shuts up the compiler.

Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 scsi/qemu-pr-helper.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/scsi/qemu-pr-helper.c b/scsi/qemu-pr-helper.c
index dd9785143b..8e475f676e 100644
--- a/scsi/qemu-pr-helper.c
+++ b/scsi/qemu-pr-helper.c
@@ -258,12 +258,12 @@ static void *dm_dev_ioctl(int fd, int ioc, struct dm_ioctl *dm)
 
 static void dm_init(void)
 {
+    struct dm_ioctl dm = {};
     control_fd = open(CONTROL_PATH, O_RDWR);
     if (control_fd < 0) {
         perror("Cannot open " CONTROL_PATH);
         exit(1);
     }
-    struct dm_ioctl dm = { 0 };
     if (!dm_ioctl(DM_VERSION, &dm)) {
         perror("ioctl");
         exit(1);
-- 
2.14.2

Re: [Qemu-devel] [PATCH] qemu-pr-helper: Do not use {0} for initialization

[Stefan Hajnoczi]

On Fri, Oct 20, 2017 at 01:21:21PM +0200, Paolo Bonzini wrote:
> The first field in struct dm_ioctl is an array, and old GCC warns
> about it with -Wmissing-braces (GCC <= 4.8).  The "{0}" universal
> zero initializer is only useful if the other side might be a scalar;
> for a struct, "{}" is enough and shuts up the compiler.
> 
> Suggested-by: Peter Maydell <peter.maydell@linaro.org>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
>  scsi/qemu-pr-helper.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>