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>

2 files changed, 3 insertions, 3 deletions

diff --git a/hw/usb/dev-network.c b/hw/usb/dev-network.c
index 9a78ad9..6210427 100644
--- a/hw/usb/dev-network.c
+++ b/hw/usb/dev-network.c
@@ -626,7 +626,7 @@ static const uint32_t oid_supported_list[] =
 struct rndis_response {
     QTAILQ_ENTRY(rndis_response) entries;
     uint32_t length;
-    uint8_t buf[0];
+    uint8_t buf[];
 };
 
 typedef struct USBNetState {
diff --git a/hw/usb/dev-smartcard-reader.c b/hw/usb/dev-smartcard-reader.c
index 02693a2..ef72738 100644
--- a/hw/usb/dev-smartcard-reader.c
+++ b/hw/usb/dev-smartcard-reader.c
@@ -227,7 +227,7 @@ typedef struct QEMU_PACKED CCID_Parameter {
 typedef struct QEMU_PACKED CCID_DataBlock {
     CCID_BULK_IN b;
     uint8_t      bChainParameter;
-    uint8_t      abData[0];
+    uint8_t      abData[];
 } CCID_DataBlock;
 
 /* 6.1.4 PC_to_RDR_XfrBlock */
@@ -235,7 +235,7 @@ typedef struct QEMU_PACKED CCID_XferBlock {
     CCID_Header  hdr;
     uint8_t      bBWI; /* Block Waiting Timeout */
     uint16_t     wLevelParameter; /* XXX currently unused */
-    uint8_t      abData[0];
+    uint8_t      abData[];
 } CCID_XferBlock;
 
 typedef struct QEMU_PACKED CCID_IccPowerOn {