Re: [PATCH v3] multi-process: Initialize variables declared with g_auto*

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

Cc'ing Miroslav

On 3/12/21 12:21 PM, Zenghui Yu wrote:
> Quote docs/devel/style.rst (section "Automatic memory deallocation"):
> 
> * Variables declared with g_auto* MUST always be initialized,
>   otherwise the cleanup function will use uninitialized stack memory
> 
> Initialize @name properly to get rid of the compilation error (using
> gcc-7.3.0 on CentOS):
> 
> ../hw/remote/proxy.c: In function 'pci_proxy_dev_realize':
> /usr/include/glib-2.0/glib/glib-autocleanups.h:28:3: error: 'name' may be used uninitialized in this function [-Werror=maybe-uninitialized]
>    g_free (*pp);
>    ^~~~~~~~~~~~
> ../hw/remote/proxy.c:350:30: note: 'name' was declared here
>              g_autofree char *name;
>                               ^~~~
> 
> Signed-off-by: Zenghui Yu <yuzenghui@huawei.com>
> Reviewed-by: Jagannathan Raman <jag.raman@oracle.com>
> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> ---
> * From v2:
>   - Add OS distro and compiler version into commit message
>   - Add Philippe's R-b
>   - Cc: qemu-trivial@nongnu.org
> 
>  hw/remote/memory.c | 5 ++---
>  hw/remote/proxy.c  | 3 +--
>  2 files changed, 3 insertions(+), 5 deletions(-)
> 
> diff --git a/hw/remote/memory.c b/hw/remote/memory.c
> index 32085b1e05..d97947d4b8 100644
> --- a/hw/remote/memory.c
> +++ b/hw/remote/memory.c
> @@ -42,10 +42,9 @@ void remote_sysmem_reconfig(MPQemuMsg *msg, Error **errp)
>  
>      remote_sysmem_reset();
>  
> -    for (region = 0; region < msg->num_fds; region++) {
> -        g_autofree char *name;
> +    for (region = 0; region < msg->num_fds; region++, suffix++) {
> +        g_autofree char *name = g_strdup_printf("remote-mem-%u", suffix);
>          subregion = g_new(MemoryRegion, 1);
> -        name = g_strdup_printf("remote-mem-%u", suffix++);
>          memory_region_init_ram_from_fd(subregion, NULL,
>                                         name, sysmem_info->sizes[region],
>                                         true, msg->fds[region],
> diff --git a/hw/remote/proxy.c b/hw/remote/proxy.c
> index 4fa4be079d..6dda705fc2 100644
> --- a/hw/remote/proxy.c
> +++ b/hw/remote/proxy.c
> @@ -347,13 +347,12 @@ static void probe_pci_info(PCIDevice *dev, Error **errp)
>                     PCI_BASE_ADDRESS_SPACE_IO : PCI_BASE_ADDRESS_SPACE_MEMORY;
>  
>          if (size) {
> -            g_autofree char *name;
> +            g_autofree char *name = g_strdup_printf("bar-region-%d", i);
>              pdev->region[i].dev = pdev;
>              pdev->region[i].present = true;
>              if (type == PCI_BASE_ADDRESS_SPACE_MEMORY) {
>                  pdev->region[i].memory = true;
>              }
> -            name = g_strdup_printf("bar-region-%d", i);
>              memory_region_init_io(&pdev->region[i].mr, OBJECT(pdev),
>                                    &proxy_mr_ops, &pdev->region[i],
>                                    name, size);
>