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>

1 files changed, 6 insertions, 6 deletions

diff --git a/include/hw/acpi/acpi-defs.h b/include/hw/acpi/acpi-defs.h
index 57a3f58b0c..19f7ba7b70 100644
--- a/include/hw/acpi/acpi-defs.h
+++ b/include/hw/acpi/acpi-defs.h
@@ -518,7 +518,7 @@ struct AcpiDmarDeviceScope {
     struct {
         uint8_t device;
         uint8_t function;
-    } path[0];
+    } path[];
 } QEMU_PACKED;
 typedef struct AcpiDmarDeviceScope AcpiDmarDeviceScope;
 
@@ -530,7 +530,7 @@ struct AcpiDmarHardwareUnit {
     uint8_t reserved;
     uint16_t pci_segment;   /* The PCI Segment associated with this unit */
     uint64_t address;   /* Base address of remapping hardware register-set */
-    AcpiDmarDeviceScope scope[0];
+    AcpiDmarDeviceScope scope[];
 } QEMU_PACKED;
 typedef struct AcpiDmarHardwareUnit AcpiDmarHardwareUnit;
 
@@ -541,7 +541,7 @@ struct AcpiDmarRootPortATS {
     uint8_t flags;
     uint8_t reserved;
     uint16_t pci_segment;
-    AcpiDmarDeviceScope scope[0];
+    AcpiDmarDeviceScope scope[];
 } QEMU_PACKED;
 typedef struct AcpiDmarRootPortATS AcpiDmarRootPortATS;
 
@@ -604,7 +604,7 @@ typedef struct AcpiIortMemoryAccess AcpiIortMemoryAccess;
 struct AcpiIortItsGroup {
     ACPI_IORT_NODE_HEADER_DEF
     uint32_t its_count;
-    uint32_t identifiers[0];
+    uint32_t identifiers[];
 } QEMU_PACKED;
 typedef struct AcpiIortItsGroup AcpiIortItsGroup;
 
@@ -621,7 +621,7 @@ struct AcpiIortSmmu3 {
     uint32_t pri_gsiv;
     uint32_t gerr_gsiv;
     uint32_t sync_gsiv;
-    AcpiIortIdMapping id_mapping_array[0];
+    AcpiIortIdMapping id_mapping_array[];
 } QEMU_PACKED;
 typedef struct AcpiIortSmmu3 AcpiIortSmmu3;
 
@@ -630,7 +630,7 @@ struct AcpiIortRC {
     AcpiIortMemoryAccess memory_properties;
     uint32_t ats_attribute;
     uint32_t pci_segment_number;
-    AcpiIortIdMapping id_mapping_array[0];
+    AcpiIortIdMapping id_mapping_array[];
 } QEMU_PACKED;
 typedef struct AcpiIortRC AcpiIortRC;