[dpdk-dev] clang compilation errors with clang 4.0

[dpdk-dev] clang compilation errors with clang 4.0

[Bruce Richardson]

Hi all,

just a heads-up that there are compilation errors showing up with
compiling DPDK with clang 4.0 release. Here are some of the errors I am
seeing. Volunteers to do patches for some of them welcome.

Regards,
/Bruce

/home/bruce/dpdk.org/lib/librte_eal/common/eal_common_tailqs.c:92:24: warning: taking address of packed member 'qlock' of class or structure 'rte_mem_config' may result in an unaligned pointer value [-Waddress-of-packed-member]
        rte_rwlock_read_lock(&mcfg->qlock);
                              ^~~~~~~~~~~


/home/bruce/dpdk.org/lib/librte_eventdev/rte_eventdev.c:371:6: warning: logical not is only applied to the left hand side of this bitwise operator [-Wlogical-not-parentheses]
        if (!dev_conf->event_dev_cfg & RTE_EVENT_DEV_CFG_PER_DEQUEUE_TIMEOUT) {
            ^                        ~

/home/bruce/dpdk.org/lib/librte_ip_frag/rte_ipv4_reassembly.c:139:31: warning: taking address of packed member 'src_addr' of class or structure 'ipv4_hdr' may result in an unaligned pointer value [-Waddress-of-packed-member]
        psd = (unaligned_uint64_t *)&ip_hdr->src_addr;
                                     ^~~~~~~~~~~~~~~~

/home/bruce/dpdk.org/lib/librte_vhost/vhost_user.c:1037:34: warning: taking address of packed member 'payload' of class or structure 'VhostUserMsg' may result in an unaligned pointer value [-Waddress-of-packed-member]
                vhost_user_set_vring_num(dev, &msg.payload.state);
                                               ^~~~~~~~~~~~~~~~~

Re: [dpdk-dev] clang compilation errors with clang 4.0

[Yuanhan Liu]

On Fri, Apr 14, 2017 at 04:55:53PM +0100, Bruce Richardson wrote:
> Hi all,
> 
> just a heads-up that there are compilation errors showing up with
> compiling DPDK with clang 4.0 release. Here are some of the errors I am
> seeing. Volunteers to do patches for some of them welcome.
> 
> Regards,
> /Bruce
> 
> /home/bruce/dpdk.org/lib/librte_eal/common/eal_common_tailqs.c:92:24: warning: taking address of packed member 'qlock' of class or structure 'rte_mem_config' may result in an unaligned pointer value [-Waddress-of-packed-member]
>         rte_rwlock_read_lock(&mcfg->qlock);
>                               ^~~~~~~~~~~
> 
> 
> /home/bruce/dpdk.org/lib/librte_eventdev/rte_eventdev.c:371:6: warning: logical not is only applied to the left hand side of this bitwise operator [-Wlogical-not-parentheses]
>         if (!dev_conf->event_dev_cfg & RTE_EVENT_DEV_CFG_PER_DEQUEUE_TIMEOUT) {
>             ^                        ~
> 
> /home/bruce/dpdk.org/lib/librte_ip_frag/rte_ipv4_reassembly.c:139:31: warning: taking address of packed member 'src_addr' of class or structure 'ipv4_hdr' may result in an unaligned pointer value [-Waddress-of-packed-member]
>         psd = (unaligned_uint64_t *)&ip_hdr->src_addr;
>                                      ^~~~~~~~~~~~~~~~
> 
> /home/bruce/dpdk.org/lib/librte_vhost/vhost_user.c:1037:34: warning: taking address of packed member 'payload' of class or structure 'VhostUserMsg' may result in an unaligned pointer value [-Waddress-of-packed-member]
>                 vhost_user_set_vring_num(dev, &msg.payload.state);
>                                                ^~~~~~~~~~~~~~~~~

Besides the 2nd warnign, all others are the same. Though I'm not quite
sure others, for this vhost-user one, I think it's a false-positive
warning.

	--yliu