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, a;
type T;
@@
struct s {
...
- T a[0];
+ T a[];
};
@@
identifier s, a;
type T;
@@
struct s {
...
- 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 <gust...@embeddedor.com>
Signed-off-by: Philippe Mathieu-Daudé <phi...@redhat.com>
---
bsd-user/qemu.h | 2 +-
contrib/libvhost-user/libvhost-user.h | 2 +-
hw/m68k/bootinfo.h | 2 +-
hw/scsi/srp.h | 6 +++---
hw/xen/xen_pt.h | 2 +-
include/hw/acpi/acpi-defs.h | 12 ++++++------
include/hw/arm/smmu-common.h | 2 +-
include/hw/i386/intel_iommu.h | 3 ++-
include/hw/virtio/virtio-iommu.h | 2 +-
include/sysemu/cryptodev.h | 2 +-
include/tcg/tcg.h | 2 +-
pc-bios/s390-ccw/bootmap.h | 2 +-
pc-bios/s390-ccw/sclp.h | 2 +-
tests/qtest/libqos/ahci.h | 2 +-
block/linux-aio.c | 2 +-
hw/acpi/nvdimm.c | 6 +++---
hw/dma/soc_dma.c | 2 +-
hw/i386/x86.c | 2 +-
hw/misc/omap_l4.c | 2 +-
hw/nvram/eeprom93xx.c | 2 +-
hw/rdma/vmw/pvrdma_qp_ops.c | 4 ++--
hw/usb/dev-network.c | 2 +-
hw/usb/dev-smartcard-reader.c | 4 ++--
hw/virtio/virtio.c | 4 ++--
net/queue.c | 2 +-
25 files changed, 38 insertions(+), 37 deletions(-)
diff --git a/bsd-user/qemu.h b/bsd-user/qemu.h
index 09e8aed9c7..f8bb1e5459 100644
--- a/bsd-user/qemu.h
+++ b/bsd-user/qemu.h
@@ -95,7 +95,7 @@ typedef struct TaskState {
struct sigqueue *first_free; /* first free siginfo queue entry */
int signal_pending; /* non zero if a signal may be pending */
- uint8_t stack[0];
+ uint8_t stack[];
} __attribute__((aligned(16))) TaskState;
void init_task_state(TaskState *ts);
diff --git a/contrib/libvhost-user/libvhost-user.h
b/contrib/libvhost-user/libvhost-user.h
index 6fc8000e99..f30394fab6 100644
--- a/contrib/libvhost-user/libvhost-user.h
+++ b/contrib/libvhost-user/libvhost-user.h
@@ -286,7 +286,7 @@ typedef struct VuVirtqInflight {
uint16_t used_idx;
/* Used to track the state of each descriptor in descriptor table */
- VuDescStateSplit desc[0];
+ VuDescStateSplit desc[];
} VuVirtqInflight;
typedef struct VuVirtqInflightDesc {
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/scsi/srp.h b/hw/scsi/srp.h
index d27f31d2d5..54c954badd 100644
--- a/hw/scsi/srp.h
+++ b/hw/scsi/srp.h
@@ -112,7 +112,7 @@ struct srp_direct_buf {
struct srp_indirect_buf {
struct srp_direct_buf table_desc;
uint32_t len;
- struct srp_direct_buf desc_list[0];
+ struct srp_direct_buf desc_list[];
} QEMU_PACKED;
enum {
@@ -211,7 +211,7 @@ struct srp_cmd {
uint8_t reserved4;
uint8_t add_cdb_len;
uint8_t cdb[16];
- uint8_t add_data[0];
+ uint8_t add_data[];
} QEMU_PACKED;
enum {
@@ -241,7 +241,7 @@ struct srp_rsp {
uint32_t data_in_res_cnt;
uint32_t sense_data_len;
uint32_t resp_data_len;
- uint8_t data[0];
+ uint8_t data[];
} QEMU_PACKED;
#endif /* SCSI_SRP_H */
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 {
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;
diff --git a/include/hw/arm/smmu-common.h b/include/hw/arm/smmu-common.h
index 1f37844e5c..ca4a4b1ad1 100644
--- a/include/hw/arm/smmu-common.h
+++ b/include/hw/arm/smmu-common.h
@@ -85,7 +85,7 @@ typedef struct SMMUDevice {
typedef struct SMMUPciBus {
PCIBus *bus;
- SMMUDevice *pbdev[0]; /* Parent array is sparse, so dynamically alloc */
+ SMMUDevice *pbdev[]; /* Parent array is sparse, so dynamically alloc */
} SMMUPciBus;
typedef struct SMMUIOTLBKey {
diff --git a/include/hw/i386/intel_iommu.h b/include/hw/i386/intel_iommu.h
index 66b931e526..67aaa64c1b 100644
--- a/include/hw/i386/intel_iommu.h
+++ b/include/hw/i386/intel_iommu.h
@@ -118,7 +118,8 @@ struct VTDAddressSpace {
struct VTDBus {
PCIBus* bus; /* A reference to the bus to provide
translation for */
- VTDAddressSpace *dev_as[0]; /* A table of VTDAddressSpace objects
indexed by devfn */
+ /* A table of VTDAddressSpace objects indexed by devfn */
+ VTDAddressSpace *dev_as[];
};
struct VTDIOTLBEntry {
diff --git a/include/hw/virtio/virtio-iommu.h b/include/hw/virtio/virtio-iommu.h
index 6f67f1020a..e653004d7c 100644
--- a/include/hw/virtio/virtio-iommu.h
+++ b/include/hw/virtio/virtio-iommu.h
@@ -41,7 +41,7 @@ typedef struct IOMMUDevice {
typedef struct IOMMUPciBus {
PCIBus *bus;
- IOMMUDevice *pbdev[0]; /* Parent array is sparse, so dynamically alloc */
+ IOMMUDevice *pbdev[]; /* Parent array is sparse, so dynamically alloc */
} IOMMUPciBus;
typedef struct VirtIOIOMMU {
diff --git a/include/sysemu/cryptodev.h b/include/sysemu/cryptodev.h
index a9afb7e5b5..35eab06d0e 100644
--- a/include/sysemu/cryptodev.h
+++ b/include/sysemu/cryptodev.h
@@ -143,7 +143,7 @@ typedef struct CryptoDevBackendSymOpInfo {
uint8_t *dst;
uint8_t *aad_data;
uint8_t *digest_result;
- uint8_t data[0];
+ uint8_t data[];
} CryptoDevBackendSymOpInfo;
typedef struct CryptoDevBackendClass {
diff --git a/include/tcg/tcg.h b/include/tcg/tcg.h
index 54e5446880..c48bd76b0a 100644
--- a/include/tcg/tcg.h
+++ b/include/tcg/tcg.h
@@ -267,7 +267,7 @@ struct TCGLabel {
typedef struct TCGPool {
struct TCGPool *next;
int size;
- uint8_t data[0] __attribute__ ((aligned));
+ uint8_t data[] __attribute__ ((aligned));
} TCGPool;
#define TCG_POOL_CHUNK_SIZE 32768
diff --git a/pc-bios/s390-ccw/bootmap.h b/pc-bios/s390-ccw/bootmap.h
index 94f53a5f1e..12a0166aae 100644
--- a/pc-bios/s390-ccw/bootmap.h
+++ b/pc-bios/s390-ccw/bootmap.h
@@ -136,7 +136,7 @@ typedef struct BootMapScriptHeader {
typedef struct BootMapScript {
BootMapScriptHeader header;
- BootMapScriptEntry entry[0];
+ BootMapScriptEntry entry[];
} __attribute__ ((packed)) BootMapScript;
/*
diff --git a/pc-bios/s390-ccw/sclp.h b/pc-bios/s390-ccw/sclp.h
index 8450161ba7..64b53cad29 100644
--- a/pc-bios/s390-ccw/sclp.h
+++ b/pc-bios/s390-ccw/sclp.h
@@ -95,7 +95,7 @@ typedef struct EventBufferHeader {
typedef struct WriteEventData {
SCCBHeader h;
EventBufferHeader ebh;
- char data[0];
+ char data[];
} __attribute__((packed)) WriteEventData;
typedef struct ReadEventData {
diff --git a/tests/qtest/libqos/ahci.h b/tests/qtest/libqos/ahci.h
index f05b3e5fce..44ab1104b5 100644
--- a/tests/qtest/libqos/ahci.h
+++ b/tests/qtest/libqos/ahci.h
@@ -351,7 +351,7 @@ typedef struct AHCIQState {
typedef struct FIS {
uint8_t fis_type;
uint8_t flags;
- char data[0];
+ char data[];
} __attribute__((__packed__)) FIS;
/**
diff --git a/block/linux-aio.c b/block/linux-aio.c
index 91204a25a2..3c0527c2bf 100644
--- a/block/linux-aio.c
+++ b/block/linux-aio.c
@@ -121,7 +121,7 @@ struct aio_ring {
unsigned incompat_features;
unsigned header_length; /* size of aio_ring */
- struct io_event io_events[0];
+ struct io_event io_events[];
};
/**
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/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/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 {
--
2.21.1
