| Message ID | 20201111142203.2359370-6-kuhn.chenqun@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | fix uninitialized variable warning | expand |
* 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 > >
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);
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> --- 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(-)