Re: [testsuite,committed] Fix prototype of memset in a test case.

[Georg-Johann Lay <avr@gjlay.de>]

On 22.12.2016 19:20, Richard Sandiford wrote:
> Georg-Johann Lay <avr@gjlay.de> writes:
>> One test case used unsigned long for the 3rd parameter of memset, which
>> should be size_t.  This made the test crash for targets where correct
>> parameter passing depends on correct prototypes.
>>
>> Fixed and committed as obvious.
>
> Catching up on backlog, but... I'm not sure this counts as obvious
> if the crash was an ICE.  We should at least fail gracefully.

The crash I mentioned happened on avr where parameter passing needs
correct prototypes.  The code crashed when executed on avr because
a long gets passed in regs R22..R25 (LSBs first) but a size_t is
passed in R24..R25.  Hence the implementation of memset would pick
up the upper two bytes of the length (zero) which crashes when run.

PR30778 was about wrong-code because more than the specified number
of bytes were written.  It was reported for x64_64 where we have
size_t = unsigned long, hence the change is a no-op on the platform
the PR was originally reported against (similar for x86 where
size_t = unsigned).

Moreover, the test case is condensed from GCC's combine.c and I'd
expect that GCC's header are using correct prototypes :-)

Johann

>
> Thanks,
> Richard
>
>>
>> Johann
>>
>>
>> gcc/testsuite/
>> 	* gcc.c-torture/execute/pr30778.c (memset): Use size_t for 3rd
>> 	parameter in declaration.
>>
>> Index: gcc.c-torture/execute/pr30778.c
>> ===================================================================
>> --- gcc.c-torture/execute/pr30778.c     (revision 242541)
>> +++ gcc.c-torture/execute/pr30778.c     (working copy)
>> @@ -1,4 +1,4 @@
>> -extern void *memset (void *, int, unsigned long);
>> +extern void *memset (void *, int, __SIZE_TYPE__);
>>   extern void abort (void);
>>
>>   struct reg_stat {
>