Re: asr(4) error with new clang/llvm

On 1 January 2015 at 23:13, Steven Hartland <killing_at_multiplay.co.uk> wrote:
>
> On 02/01/2015 01:23, Bjoern A. Zeeb wrote:
>>
>> Hi,
>>
>> you need the next line of source to see that while the union only defines
>> Simple[1], the comparison goes up to SG_LIST (or something) which is indeed
>> defined as 58.   Cn someone fix this?   This makes i386 compiles failing
>> currently.
>>
>> /scratch/tmp/bz/head.svn/sys/modules/asr/../../dev/asr/asr.c:1849:29:
>> error: array index 58 is past the end of the array (which contains 1
>> element) [-Werror,-Warray-bounds]
>>          while ((len > 0) && (sg < &((PPRIVATE_SCSI_SCB_EXECUTE_MESSAGE)
>>                                     ^
>> /scratch/tmp/bz/head.svn/sys/dev/asr/i2omsg.h:934:8: note: array 'Simple'
>> declared here
>>         I2O_SGE_SIMPLE_ELEMENT              Simple[1];
>>         ^
>
> If that's wrong it looks like there's also a number of calls to the macro
> SG(SGL,Index,Flags,Buffer,Size)  which are also wrong as Index is used in
> the same way:
> &(((PI2O_SG_ELEMENT)(SGL))->u.Simple[Index]
>
> There appears to be two calls to SG where Index is 1.
>
> I'm afraid I have no idea what the fix would be as the entire driver is very
> voodoo like to me :(

It's a variable length array in a struct / union. Other than being
confusing and now triggering a warning after the clang update it
should be fine.

Most likely we need to build asr with -Werror disabled for that
warning, perhaps -Wno-error-array-bounds. I'll take a look tomorrow
morning if nobody else gets to it first.