RFR (XS): 80357290: Code using assert(is_oop_or_null) needs better error messages

[Thomas Schatzl]

Hi,

On Wed, 2014-08-06 at 10:28 +0200, Marcus Larsson wrote:
> Hi,
> 
> Can I have reviews for this small change adding oop information to 
> is_oop_or_null assert fail messages?
> 
> CR:
> http://cr.openjdk.java.net/~brutisso/webrev-8035729/
> 
> Bug:
> https://bugs.openjdk.java.net/browse/JDK-8035729/

  not sure what the other think, but is it worth to try to make the
error messages themselves be more uniform?
While I do not want to be all the same, we have:

1) expected an oop or NULL
2) expected an oop or NULL:
3) Not an oop? (
4) check for header:
5) should be an oop now:
6) Object should be whole at this point:
7) Not an oop:
8) discovered field is bad: 
9) bad referent:
10) bad next field: 
11) bad discovered field: 
12) should always be an oop: 

Some suggestions:

- Capitalize the first letter of the sentences
- change 1 to "Expected an oop or NULL at "
- replace 2,3,5,6,7,12 by 1
- change 4,9-11 to "Expected an oop for <type> field at "

Otherwise the change is good.

Thanks,
  Thomas