Re: [Qemu-devel] [PATCH] net: cadence_gem: fix compilation error when debug is on

[Ramon Fried <rfried.dev@gmail.com>]

On Tue, Jun 11, 2019 at 11:34 AM Philippe Mathieu-Daudé <philmd@redhat.com>
wrote:

> Hi Ramon,
>
> On 6/9/19 12:08 PM, Ramon Fried wrote:
> > defining CADENCE_GEM_ERR_DEBUG causes compilation
> > errors, fix that.
> >
> > Signed-off-by: Ramon Fried <rfried.dev@gmail.com>
> > ---
> >  hw/net/cadence_gem.c | 6 +++---
> >  1 file changed, 3 insertions(+), 3 deletions(-)
> >
> > diff --git a/hw/net/cadence_gem.c b/hw/net/cadence_gem.c
> > index 7f63411430..5cc5a71524 100644
> > --- a/hw/net/cadence_gem.c
> > +++ b/hw/net/cadence_gem.c
> > @@ -982,8 +982,8 @@ static ssize_t gem_receive(NetClientState *nc, const
> uint8_t *buf, size_t size)
> >              return -1;
> >          }
> >
> > -        DB_PRINT("copy %d bytes to 0x%x\n", MIN(bytes_to_copy,
> rxbufsize),
> > -                rx_desc_get_buffer(s->rx_desc[q]));
> > +        DB_PRINT("copy %d bytes to 0x%lx\n", MIN(bytes_to_copy,
> rxbufsize),
> > +                rx_desc_get_buffer(s, s->rx_desc[q]));
>
> Your patch fails on 32-bit hosts:
>
> ./hw/net/cadence_gem.c:987:18: error: format '%lx' expects argument of
> type 'long unsigned int', but argument 4 has type 'uint64_t {aka long
> long unsigned int}' [-Werror=format=]
>          DB_PRINT("copy %d bytes to 0x%lx\n", MIN(bytes_to_copy,
> rxbufsize),
>                   ^
> ./hw/net/cadence_gem.c:39:24: note: in definition of macro 'DB_PRINT'
>      fprintf(stderr, ## __VA_ARGS__); \
>                         ^
> ./hw/net/cadence_gem.c: In function 'gem_transmit':
> ./hw/net/cadence_gem.c:1160:26: error: format '%lx' expects argument of
> type 'long unsigned int', but argument 5 has type 'unsigned int'
> [-Werror=format=]
>                  DB_PRINT("TX descriptor @ 0x%x too large: size 0x%x
> space " \
>                           ^
> ./hw/net/cadence_gem.c:39:24: note: in definition of macro 'DB_PRINT'
>      fprintf(stderr, ## __VA_ARGS__); \
>                         ^
> cc1: all warnings being treated as errors
>
> QEMU provides "HWADDR_PRIx" format for addresses, see for example few
> lines earlier:
>
>     DB_PRINT("read descriptor 0x%" HWADDR_PRIx "\n", packet_desc_addr);
>
>
> >
> >          /* Copy packet data to emulated DMA buffer */
> >          address_space_write(&s->dma_as, rx_desc_get_buffer(s,
> s->rx_desc[q]) +
> > @@ -1156,7 +1156,7 @@ static void gem_transmit(CadenceGEMState *s)
> >              if (tx_desc_get_length(desc) > sizeof(tx_packet) -
> >                                                 (p - tx_packet)) {
> >                  DB_PRINT("TX descriptor @ 0x%x too large: size 0x%x
> space " \
> > -                         "0x%x\n", (unsigned)packet_desc_addr,
> > +                         "0x%lx\n", (unsigned)packet_desc_addr,
>
> Here the correct format seems to be "%zd" (difference of sizeof).
>
> >                           (unsigned)tx_desc_get_length(desc),
> >                           sizeof(tx_packet) - (p - tx_packet));
> >                  break;
> >
>
> Nowadays QEMU prefers to move from the old DB_PRINT() macros to the
> trace events API, see for example this commit:
>
>
> https://git.qemu.org/?p=qemu.git;a=commitdiff;h=da1804d17a9ed7f060c072fbc4889db5fbc9c7d2;hp=a4f667b6714916683408b983cfe0a615a725775f
>
> The first line you changed would be replaced by a trace event, while the
> second could be replaced by a qemu_log_mask() call (it is an error
> condition).
>
> Also I suggest to include "QEMU Trivial <qemu-trivial@nongnu.org>" in
> the list of recipients, so your patch might get reviewed/merged quicker.
>
> Regards,
>
> Phil.
>

Hi Phil,
Thanks for the review, I'll send v2 soon.