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authorPhilippe Mathieu-Daudé <philmd@redhat.com>2020-03-04 16:38:15 +0100
committerPaolo Bonzini <pbonzini@redhat.com>2020-03-16 22:07:42 +0100
commitf7795e4096d8bd1c767c5ddb450fa859ff20490e (patch)
treec7767c88747e00be8118f81349bce043bc2f2959 /net/queue.c
parent770275ed0c0ab05677472efcf184b1a02ab14d07 (diff)
downloadfocaccia-qemu-f7795e4096d8bd1c767c5ddb450fa859ff20490e.tar.gz
focaccia-qemu-f7795e4096d8bd1c767c5ddb450fa859ff20490e.zip
misc: Replace zero-length arrays with flexible array member (automatic)
Description copied from Linux kernel commit from Gustavo A. R. Silva
(see [3]):

--v-- description start --v--

  The current codebase makes use of the zero-length array language
  extension to the C90 standard, but the preferred mechanism to
  declare variable-length types such as these ones is a flexible
  array member [1], introduced in C99:

  struct foo {
      int stuff;
      struct boo array[];
  };

  By making use of the mechanism above, we will get a compiler
  warning in case the flexible array does not occur last in the
  structure, which will help us prevent some kind of undefined
  behavior bugs from being unadvertenly introduced [2] to the
  Linux codebase from now on.

--^-- description end --^--

Do the similar housekeeping in the QEMU codebase (which uses
C99 since commit 7be41675f7cb).

All these instances of code were found with the help of the
following Coccinelle script:

  @@
  identifier s, m, a;
  type t, T;
  @@
   struct s {
      ...
      t m;
  -   T a[0];
  +   T a[];
  };
  @@
  identifier s, m, a;
  type t, T;
  @@
   struct s {
      ...
      t m;
  -   T a[0];
  +   T a[];
   } QEMU_PACKED;

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=76497732932f
[3] https://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux.git/commit/?id=17642a2fbd2c1

Inspired-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'net/queue.c')
-rw-r--r--net/queue.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/net/queue.c b/net/queue.c
index 61276ca4be..0164727e39 100644
--- a/net/queue.c
+++ b/net/queue.c
@@ -46,7 +46,7 @@ struct NetPacket {
     unsigned flags;
     int size;
     NetPacketSent *sent_cb;
-    uint8_t data[0];
+    uint8_t data[];
 };
 
 struct NetQueue {