RFR: 8227633: avoid comparing this pointers to NULL

[coleen.phillimore at oracle.com]

This looks good to me.  I don't know this compiler code very well, so 
please wait for a second reviewer.
Thanks,
Coleen

On 7/16/19 9:01 AM, Baesken, Matthias wrote:
> Hello Coleen ,
>
> I adjusted the check in   formssel.cpp   to      if (mnode != NULL)   ,
>
>>> I didn't see that you added a check for NULL in the callers of
>>> print_opcodes
>   and added NULL checks to the  _inst._opcode->print_opcode   calls  in   src/hotspot/share/adlc/output_c.cpp  .
>
> Regarding   Set::setstr()  in src/hotspot/share/libadt/set.cpp  ,
>   This is   used  in print()   and  this  can be called  "conveniently in the debugger"  (see set.hpp ).
> So I think it is okay to remove the check .
>
>
> please  see   the new webrev  :
>
> http://cr.openjdk.java.net/~mbaesken/webrevs/8227633.2/
>
>
> Thanks, Matthias
>
>
>
>>> + if (mnode) mnode->count_instr_names(names);
>>>
>>>
>>> We also try to avoid implicit checks against null for pointers so change
>>> this to:
>>>
>> Hi Coleen, sure I can change this ; I just found a lot of places   in  formssel.cpp
>> where  if (ptr) { ...  }    is used  .
>>
>>> I didn't see that you added a check for NULL in the callers of
>>> print_opcodes or setstr.? Can those callers never pass NULL?
>>>
>> It looked to me that the setstr   is never really called  and  void Set::print()
>> const { ... }   where it is used is used for debug printing - did I miss something
>> ?
>>
>> Regarding print_opcodes   ,  there probably  the NULL checks at caller palces
>> should better be added .
>>
>> Regards, Matthias
>>