| Message ID | 20201006154256.17392-1-alex.bennee@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | hw/ide/ahci: silence a compiler warning | expand |
On 10/6/20 5:42 PM, Alex Bennée wrote: > When built with -Og -ggdb with gcc 8.3 the compiler gets confused > reporting: > > ../../hw/ide/ahci.c: In function ‘ahci_populate_sglist’: > ../../hw/ide/ahci.c:965:58: error: ‘tbl_entry_size’ may be used uninitialized in this function [-Werror=maybe-uninitialized] > > As prdtl being > 0 is a prerequisite for running the code which > guarantees we execute the loop at least once although not necessarily > resetting off_pos/off_idx which should short-circuit the test anyway. > > To save grey hair initialise the value to zero and move the variable > to the local block so future changes can't accidentally use it. Paolo fixed it yesterday but forgot to Cc you: https://www.mail-archive.com/qemu-block@nongnu.org/msg75131.html As your patch is also valid (and simpler): Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> > > Signed-off-by: Alex Bennée <alex.bennee@linaro.org> > --- > hw/ide/ahci.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/hw/ide/ahci.c b/hw/ide/ahci.c > index 680304a24c..f5c20c7d55 100644 > --- a/hw/ide/ahci.c > +++ b/hw/ide/ahci.c > @@ -925,7 +925,6 @@ static int ahci_populate_sglist(AHCIDevice *ad, QEMUSGList *sglist, > uint64_t sum = 0; > int off_idx = -1; > int64_t off_pos = -1; > - int tbl_entry_size; > IDEBus *bus = &ad->port; > BusState *qbus = BUS(bus); > > @@ -952,6 +951,7 @@ static int ahci_populate_sglist(AHCIDevice *ad, QEMUSGList *sglist, > /* Get entries in the PRDT, init a qemu sglist accordingly */ > if (prdtl > 0) { > AHCI_SG *tbl = (AHCI_SG *)prdt; > + int tbl_entry_size = 0; > sum = 0; > for (i = 0; i < prdtl; i++) { > tbl_entry_size = prdt_tbl_entry_size(&tbl[i]); >
diff --git a/hw/ide/ahci.c b/hw/ide/ahci.c index 680304a24c..f5c20c7d55 100644 --- a/hw/ide/ahci.c +++ b/hw/ide/ahci.c @@ -925,7 +925,6 @@ static int ahci_populate_sglist(AHCIDevice *ad, QEMUSGList *sglist, uint64_t sum = 0; int off_idx = -1; int64_t off_pos = -1; - int tbl_entry_size; IDEBus *bus = &ad->port; BusState *qbus = BUS(bus); @@ -952,6 +951,7 @@ static int ahci_populate_sglist(AHCIDevice *ad, QEMUSGList *sglist, /* Get entries in the PRDT, init a qemu sglist accordingly */ if (prdtl > 0) { AHCI_SG *tbl = (AHCI_SG *)prdt; + int tbl_entry_size = 0; sum = 0; for (i = 0; i < prdtl; i++) { tbl_entry_size = prdt_tbl_entry_size(&tbl[i]);
When built with -Og -ggdb with gcc 8.3 the compiler gets confused reporting: ../../hw/ide/ahci.c: In function ‘ahci_populate_sglist’: ../../hw/ide/ahci.c:965:58: error: ‘tbl_entry_size’ may be used uninitialized in this function [-Werror=maybe-uninitialized] As prdtl being > 0 is a prerequisite for running the code which guarantees we execute the loop at least once although not necessarily resetting off_pos/off_idx which should short-circuit the test anyway. To save grey hair initialise the value to zero and move the variable to the local block so future changes can't accidentally use it. Signed-off-by: Alex Bennée <alex.bennee@linaro.org> --- hw/ide/ahci.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)