Re: [PATCH v2 5/5] migration: fix uninitialized variable warning in migrate_send_rp_req_pages()

[Dr. David Alan Gilbert]

* Chen Qun (kuhn.chenqun@huawei.com) wrote:
> After the WITH_QEMU_LOCK_GUARD macro is added, the compiler cannot identify
>  that the statements in the macro must be executed. As a result, some 
> variables
>  assignment statements in the macro may be considered as unexecuted by the 
> compiler.
> 
> When the -Wmaybe-uninitialized capability is enabled on GCC9,the compiler 
> showed warning:
> migration/migration.c: In function ‘migrate_send_rp_req_pages’:
> migration/migration.c:384:8: warning: ‘received’ may be used uninitialized in 
> this function [-Wmaybe-uninitialized]
>  384 |     if (received) {
>      |        ^
> 
> Add a default value for 'received' to prevented the warning.
> 
> Reported-by: Euler Robot <euler.robot@huawei.com>
> Signed-off-by: Chen Qun <kuhn.chenqun@huawei.com>
> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>

Queuing this one via migration

> ---
> Cc: Juan Quintela <quintela@redhat.com>
> Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
> ---
>  migration/migration.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/migration/migration.c b/migration/migration.c
> index 9bb4fee5ac..de90486a61 100644
> --- a/migration/migration.c
> +++ b/migration/migration.c
> @@ -361,7 +361,7 @@ int migrate_send_rp_req_pages(MigrationIncomingState *mis,
>                                RAMBlock *rb, ram_addr_t start, uint64_t haddr)
>  {
>      void *aligned = (void *)(uintptr_t)(haddr & (-qemu_ram_pagesize(rb)));
> -    bool received;
> +    bool received = false;
>  
>      WITH_QEMU_LOCK_GUARD(&mis->page_request_mutex) {
>          received = ramblock_recv_bitmap_test_byte_offset(rb, start);
> -- 
> 2.27.0
> 
> 
-- 
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK