Re: [Qemu-devel] Hacks for building on gcc 7 / Fedora 26

[Daniel P. Berrange]

On Fri, Apr 07, 2017 at 03:38:47PM +0100, Dr. David Alan Gilbert wrote:
> Hi,
>    Fedora 26 has gcc 7.0.1 which has the normal compliment
> of new fussy warnings; so far I've posted :
> 
> tests/check-qdict: Fix missing brackets
> slirp/smb: Replace constant strings by glib string
> 
> that fix one actual mistake and work around something it's being
> fussy over.
> 
> But I've also got a pile of hacks, attached below that I'm
> not too sure what I'll do with them yet, but they're attached
> for anyone else trying to build.  Note they're smoke-only-tested.
> 
> I also have gcc bug https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80346
> filed for what I reckon is a couple of overly pessimistic warnings.


> diff --git a/include/qemu/iov.h b/include/qemu/iov.h
> index bd9fd55b0a..ebb0221140 100644
> --- a/include/qemu/iov.h
> +++ b/include/qemu/iov.h
> @@ -46,7 +46,7 @@ static inline size_t
>  iov_from_buf(const struct iovec *iov, unsigned int iov_cnt,
>               size_t offset, const void *buf, size_t bytes)
>  {
> -    if (__builtin_constant_p(bytes) && iov_cnt &&
> +    if (__builtin_constant_p(bytes) && iov_cnt && bytes <= INT_MAX &&
>          offset <= iov[0].iov_len && bytes <= iov[0].iov_len - offset) {
>          memcpy(iov[0].iov_base + offset, buf, bytes);
>          return bytes;
> @@ -59,7 +59,7 @@ static inline size_t
>  iov_to_buf(const struct iovec *iov, const unsigned int iov_cnt,
>             size_t offset, void *buf, size_t bytes)
>  {
> -    if (__builtin_constant_p(bytes) && iov_cnt &&
> +    if (__builtin_constant_p(bytes) && iov_cnt && bytes <= INT_MAX &&
>          offset <= iov[0].iov_len && bytes <= iov[0].iov_len - offset) {
>          memcpy(buf, iov[0].iov_base + offset, bytes);
>          return bytes;
> diff --git a/tests/bios-tables-test.c b/tests/bios-tables-test.c
> index 88dbf97853..c55de4f65b 100644
> --- a/tests/bios-tables-test.c
> +++ b/tests/bios-tables-test.c
> @@ -98,7 +98,7 @@ static void test_acpi_rsdt_table(test_data *data)
>      AcpiRsdtDescriptorRev1 *rsdt_table = &data->rsdt_table;
>      uint32_t addr = data->rsdp_table.rsdt_physical_address;
>      uint32_t *tables;
> -    int tables_nr;
> +    unsigned int tables_nr;
>      uint8_t checksum;
>  
>      /* read the header */

Unless I've missed a patch somwhere, I think the problems that these two
chunks are fixing are still needed for current git master, to stop warnings
in the unit tests.


Regards,
Daniel
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