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>

11 files changed, 16 insertions, 16 deletions

diff --git a/hw/acpi/nvdimm.c b/hw/acpi/nvdimm.c
index 5219dd0e2e..eb6a37b14e 100644
--- a/hw/acpi/nvdimm.c
+++ b/hw/acpi/nvdimm.c
@@ -485,7 +485,7 @@ struct NvdimmFuncGetLabelDataOut {
     /* the size of buffer filled by QEMU. */
     uint32_t len;
     uint32_t func_ret_status; /* return status code. */
-    uint8_t out_buf[0]; /* the data got via Get Namesapce Label function. */
+    uint8_t out_buf[]; /* the data got via Get Namesapce Label function. */
 } QEMU_PACKED;
 typedef struct NvdimmFuncGetLabelDataOut NvdimmFuncGetLabelDataOut;
 QEMU_BUILD_BUG_ON(sizeof(NvdimmFuncGetLabelDataOut) > NVDIMM_DSM_MEMORY_SIZE);
@@ -493,7 +493,7 @@ QEMU_BUILD_BUG_ON(sizeof(NvdimmFuncGetLabelDataOut) > NVDIMM_DSM_MEMORY_SIZE);
 struct NvdimmFuncSetLabelDataIn {
     uint32_t offset; /* the offset in the namespace label data area. */
     uint32_t length; /* the size of data is to be written via the function. */
-    uint8_t in_buf[0]; /* the data written to label data area. */
+    uint8_t in_buf[]; /* the data written to label data area. */
 } QEMU_PACKED;
 typedef struct NvdimmFuncSetLabelDataIn NvdimmFuncSetLabelDataIn;
 QEMU_BUILD_BUG_ON(sizeof(NvdimmFuncSetLabelDataIn) +
@@ -510,7 +510,7 @@ struct NvdimmFuncReadFITOut {
     /* the size of buffer filled by QEMU. */
     uint32_t len;
     uint32_t func_ret_status; /* return status code. */
-    uint8_t fit[0]; /* the FIT data. */
+    uint8_t fit[]; /* the FIT data. */
 } QEMU_PACKED;
 typedef struct NvdimmFuncReadFITOut NvdimmFuncReadFITOut;
 QEMU_BUILD_BUG_ON(sizeof(NvdimmFuncReadFITOut) > NVDIMM_DSM_MEMORY_SIZE);
diff --git a/hw/dma/soc_dma.c b/hw/dma/soc_dma.c
index c3e41581b6..3a430057f5 100644
--- a/hw/dma/soc_dma.c
+++ b/hw/dma/soc_dma.c
@@ -80,7 +80,7 @@ struct dma_s {
     } *memmap;
     int memmap_size;
 
-    struct soc_dma_ch_s ch[0];
+    struct soc_dma_ch_s ch[];
 };
 
 static void soc_dma_ch_schedule(struct soc_dma_ch_s *ch, int delay_bytes)
diff --git a/hw/i386/x86.c b/hw/i386/x86.c
index 7f38e6ba8b..08246523f2 100644
--- a/hw/i386/x86.c
+++ b/hw/i386/x86.c
@@ -328,7 +328,7 @@ struct setup_data {
     uint64_t next;
     uint32_t type;
     uint32_t len;
-    uint8_t data[0];
+    uint8_t data[];
 } __attribute__((packed));
 
 
diff --git a/hw/m68k/bootinfo.h b/hw/m68k/bootinfo.h
index 5f8ded2686..c954270aad 100644
--- a/hw/m68k/bootinfo.h
+++ b/hw/m68k/bootinfo.h
@@ -14,7 +14,7 @@
 struct bi_record {
     uint16_t tag;        /* tag ID */
     uint16_t size;       /* size of record */
-    uint32_t data[0];    /* data */
+    uint32_t data[];     /* data */
 };
 
 /* machine independent tags */
diff --git a/hw/misc/omap_l4.c b/hw/misc/omap_l4.c
index 61b6df564a..54aeaecd69 100644
--- a/hw/misc/omap_l4.c
+++ b/hw/misc/omap_l4.c
@@ -24,7 +24,7 @@ struct omap_l4_s {
     MemoryRegion *address_space;
     hwaddr base;
     int ta_num;
-    struct omap_target_agent_s ta[0];
+    struct omap_target_agent_s ta[];
 };
 
 struct omap_l4_s *omap_l4_init(MemoryRegion *address_space,
diff --git a/hw/nvram/eeprom93xx.c b/hw/nvram/eeprom93xx.c
index 07f09549ed..ca6f591c84 100644
--- a/hw/nvram/eeprom93xx.c
+++ b/hw/nvram/eeprom93xx.c
@@ -86,7 +86,7 @@ struct _eeprom_t {
     uint8_t  addrbits;
     uint16_t size;
     uint16_t data;
-    uint16_t contents[0];
+    uint16_t contents[];
 };
 
 /* Code for saving and restoring of EEPROM state. */
diff --git a/hw/rdma/vmw/pvrdma_qp_ops.c b/hw/rdma/vmw/pvrdma_qp_ops.c
index bd6db858de..8050287a6c 100644
--- a/hw/rdma/vmw/pvrdma_qp_ops.c
+++ b/hw/rdma/vmw/pvrdma_qp_ops.c
@@ -34,13 +34,13 @@ typedef struct CompHandlerCtx {
 /* Send Queue WQE */
 typedef struct PvrdmaSqWqe {
     struct pvrdma_sq_wqe_hdr hdr;
-    struct pvrdma_sge sge[0];
+    struct pvrdma_sge sge[];
 } PvrdmaSqWqe;
 
 /* Recv Queue WQE */
 typedef struct PvrdmaRqWqe {
     struct pvrdma_rq_wqe_hdr hdr;
-    struct pvrdma_sge sge[0];
+    struct pvrdma_sge sge[];
 } PvrdmaRqWqe;
 
 /*
diff --git a/hw/usb/dev-network.c b/hw/usb/dev-network.c
index 9a78ad928b..6210427544 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 02693a26ad..ef72738ced 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 {
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index b2d415e5dd..b6c8ef5bc0 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -54,7 +54,7 @@ typedef struct VRingAvail
 {
     uint16_t flags;
     uint16_t idx;
-    uint16_t ring[0];
+    uint16_t ring[];
 } VRingAvail;
 
 typedef struct VRingUsedElem
@@ -67,7 +67,7 @@ typedef struct VRingUsed
 {
     uint16_t flags;
     uint16_t idx;
-    VRingUsedElem ring[0];
+    VRingUsedElem ring[];
 } VRingUsed;
 
 typedef struct VRingMemoryRegionCaches {
diff --git a/hw/xen/xen_pt.h b/hw/xen/xen_pt.h
index 9167bbaf6d..179775db7b 100644
--- a/hw/xen/xen_pt.h
+++ b/hw/xen/xen_pt.h
@@ -203,7 +203,7 @@ typedef struct XenPTMSIX {
     uint64_t mmio_base_addr;
     MemoryRegion mmio;
     void *phys_iomem_base;
-    XenPTMSIXEntry msix_entry[0];
+    XenPTMSIXEntry msix_entry[];
 } XenPTMSIX;
 
 struct XenPCIPassthroughState {