Re: [PATCH] Use g_new() & friends where that makes obvious sense

[Michael S. Tsirkin]

On Fri, Sep 23, 2022 at 10:42:54AM +0200, Markus Armbruster wrote:
> g_new(T, n) is neater than g_malloc(sizeof(T) * n).  It's also safer,
> for two reasons.  One, it catches multiplication overflowing size_t.
> Two, it returns T * rather than void *, which lets the compiler catch
> more type errors.
> 
> This commit only touches allocations with size arguments of the form
> sizeof(T).
> 
> Patch created mechanically with:
> 
>     $ spatch --in-place --sp-file scripts/coccinelle/use-g_new-etc.cocci \
>            --macro-file scripts/cocci-macro-file.h FILES...
> 
> The previous iteration was commit a95942b50c.
> 
> Signed-off-by: Markus Armbruster <armbru@redhat.com>

Reviewed-by: Michael S. Tsirkin <mst@redhat.com>

> ---
>  hw/remote/iommu.c         | 2 +-
>  hw/virtio/virtio-crypto.c | 2 +-
>  migration/dirtyrate.c     | 4 ++--
>  softmmu/dirtylimit.c      | 4 ++--
>  4 files changed, 6 insertions(+), 6 deletions(-)
> 
> diff --git a/hw/remote/iommu.c b/hw/remote/iommu.c
> index fd723d91f3..1391dd712c 100644
> --- a/hw/remote/iommu.c
> +++ b/hw/remote/iommu.c
> @@ -47,7 +47,7 @@ static AddressSpace *remote_iommu_find_add_as(PCIBus 
> *pci_bus,
>      elem = g_hash_table_lookup(iommu->elem_by_devfn, INT2VOIDP(devfn));
>  
>      if (!elem) {
> -        elem = g_malloc0(sizeof(RemoteIommuElem));
> +        elem = g_new0(RemoteIommuElem, 1);
>          g_hash_table_insert(iommu->elem_by_devfn, INT2VOIDP(devfn), elem);
>      }
>  
> diff --git a/hw/virtio/virtio-crypto.c b/hw/virtio/virtio-crypto.c
> index c1243c3f93..df4bde210b 100644
> --- a/hw/virtio/virtio-crypto.c
> +++ b/hw/virtio/virtio-crypto.c
> @@ -710,7 +710,7 @@ virtio_crypto_handle_asym_req(VirtIOCrypto *vcrypto,
>      uint8_t *src = NULL;
>      uint8_t *dst = NULL;
>  
> -    asym_op_info = g_malloc0(sizeof(CryptoDevBackendAsymOpInfo));
> +    asym_op_info = g_new0(CryptoDevBackendAsymOpInfo, 1);
>      src_len = ldl_le_p(&req->para.src_data_len);
>      dst_len = ldl_le_p(&req->para.dst_data_len);
>  
> diff --git a/migration/dirtyrate.c b/migration/dirtyrate.c
> index 795fab5c37..d6f1e01a70 100644
> --- a/migration/dirtyrate.c
> +++ b/migration/dirtyrate.c
> @@ -119,9 +119,9 @@ static DirtyPageRecord *vcpu_dirty_stat_alloc(VcpuStat 
> *stat)
>      }
>  
>      stat->nvcpu = nvcpu;
> -    stat->rates = g_malloc0(sizeof(DirtyRateVcpu) * nvcpu);
> +    stat->rates = g_new0(DirtyRateVcpu, nvcpu);
>  
> -    records = g_malloc0(sizeof(DirtyPageRecord) * nvcpu);
> +    records = g_new0(DirtyPageRecord, nvcpu);
>  
>      return records;
>  }
> diff --git a/softmmu/dirtylimit.c b/softmmu/dirtylimit.c
> index 8d98cb7f2c..12668555f2 100644
> --- a/softmmu/dirtylimit.c
> +++ b/softmmu/dirtylimit.c
> @@ -154,7 +154,7 @@ void vcpu_dirty_rate_stat_initialize(void)
>  
>      vcpu_dirty_rate_stat->stat.nvcpu = max_cpus;
>      vcpu_dirty_rate_stat->stat.rates =
> -        g_malloc0(sizeof(DirtyRateVcpu) * max_cpus);
> +        g_new0(DirtyRateVcpu, max_cpus);
>  
>      vcpu_dirty_rate_stat->running = false;
>  }
> @@ -198,7 +198,7 @@ void dirtylimit_state_initialize(void)
>      dirtylimit_state = g_malloc0(sizeof(*dirtylimit_state));
>  
>      dirtylimit_state->states =
> -            g_malloc0(sizeof(VcpuDirtyLimitState) * max_cpus);
> +            g_new0(VcpuDirtyLimitState, max_cpus);
>  
>      for (i = 0; i < max_cpus; i++) {
>          dirtylimit_state->states[i].cpu_index = i;
> -- 
> 2.37.2