Re: [dpdk-dev] [PATCH] ixgbe: fix build with gcc 4.4

[Vlad Zolotarov <vladz@cloudius-systems.com>]

On 04/14/15 16:23, Ananyev, Konstantin wrote:
>
>> -----Original Message-----
>> From: Vlad Zolotarov [mailto:vladz@cloudius-systems.com]
>> Sent: Tuesday, April 14, 2015 1:52 PM
>> To: Thomas Monjalon; Ananyev, Konstantin; Zhang, Helin
>> Cc: dev@dpdk.org
>> Subject: Re: [PATCH] ixgbe: fix build with gcc 4.4
>>
>>
>>
>> On 04/14/15 12:31, Thomas Monjalon wrote:
>>> With GCC 4.4.7 from CentOS 6.5, the following errors arise:
>>>
>>> lib/librte_pmd_ixgbe/ixgbe_rxtx.c: In function ‘ixgbe_dev_rx_queue_setup’:
>>> lib/librte_pmd_ixgbe/ixgbe_rxtx.c:2509: error: missing initializer
>>> lib/librte_pmd_ixgbe/ixgbe_rxtx.c:2509: error: (near initialization for ‘dev_info.driver_name’)
>>>
>>> lib/librte_pmd_ixgbe/ixgbe_rxtx.c: In function ‘ixgbe_set_rsc’:
>>> lib/librte_pmd_ixgbe/ixgbe_rxtx.c:4072: error: missing initializer
>>> lib/librte_pmd_ixgbe/ixgbe_rxtx.c:4072: error: (near initialization for ‘dev_info.driver_name’)
>>>
>>> lib/librte_pmd_ixgbe/ixgbe_rxtx.c: In function ‘ixgbe_recv_pkts_lro_single_alloc’:
>>> lib/librte_pmd_ixgbe/ixgbe_rxtx.c:1479: error: ‘next_rsc_entry’ may be used uninitialized in this function
>>> lib/librte_pmd_ixgbe/ixgbe_rxtx.c:1480: error: ‘next_rxe’ may be used uninitialized in this function
>> :D Looks like a gcc bug ;) Both are set and only after that (!!!) used
>> under "!eop" condition.
> Possibly, but we still need to make it build cleanly.

It's clearly - I was just trying to be polite here... ;)
Please, add the comment explaining this initialization so that nobody 
removes these workarounds by mistake...

> Konstantin
>
>>> Fixes: 8eecb3295aed ("ixgbe: add LRO support")
>>>
>>> Signed-off-by: Thomas Monjalon <thomas.monjalon@6wind.com>
>>> ---
>>>    lib/librte_pmd_ixgbe/ixgbe_rxtx.c | 8 ++++----
>>>    1 file changed, 4 insertions(+), 4 deletions(-)
>>>
>>> diff --git a/lib/librte_pmd_ixgbe/ixgbe_rxtx.c b/lib/librte_pmd_ixgbe/ixgbe_rxtx.c
>>> index f1da9ec..a2b8631 100644
>>> --- a/lib/librte_pmd_ixgbe/ixgbe_rxtx.c
>>> +++ b/lib/librte_pmd_ixgbe/ixgbe_rxtx.c
>>> @@ -1476,8 +1476,8 @@ ixgbe_recv_pkts_lro(void *rx_queue, struct rte_mbuf **rx_pkts, uint16_t nb_pkts,
>>>    		bool eop;
>>>    		struct ixgbe_rx_entry *rxe;
>>>    		struct ixgbe_rsc_entry *rsc_entry;
>>> -		struct ixgbe_rsc_entry *next_rsc_entry;
>>> -		struct ixgbe_rx_entry *next_rxe;
>>> +		struct ixgbe_rsc_entry *next_rsc_entry = NULL;
>>> +		struct ixgbe_rx_entry *next_rxe = NULL;
>>>    		struct rte_mbuf *first_seg;
>>>    		struct rte_mbuf *rxm;
>>>    		struct rte_mbuf *nmb;
>>> @@ -2506,7 +2506,7 @@ ixgbe_dev_rx_queue_setup(struct rte_eth_dev *dev,
>>>    	struct ixgbe_rx_queue *rxq;
>>>    	struct ixgbe_hw     *hw;
>>>    	uint16_t len;
>>> -	struct rte_eth_dev_info dev_info = { 0 };
>>> +	struct rte_eth_dev_info dev_info = { .max_rx_queues = 0 };
>>>    	struct rte_eth_rxmode *dev_rx_mode = &dev->data->dev_conf.rxmode;
>>>    	bool rsc_requested = false;
>>>
>>> @@ -4069,7 +4069,7 @@ ixgbe_set_rsc(struct rte_eth_dev *dev)
>>>    {
>>>    	struct rte_eth_rxmode *rx_conf = &dev->data->dev_conf.rxmode;
>>>    	struct ixgbe_hw *hw = IXGBE_DEV_PRIVATE_TO_HW(dev->data->dev_private);
>>> -	struct rte_eth_dev_info dev_info = { 0 };
>>> +	struct rte_eth_dev_info dev_info = { .max_rx_queues = 0 };
>>>    	bool rsc_capable = false;
>>>    	uint16_t i;
>>>    	uint32_t rdrxctl;