RFR (XS): 8129855: -XX:+IgnoreUnrecognizedVMOptions hides "out of range" VM options.

[gerard ziemski]

hi all,

Please review this small fix (also need a sponsor). It fixes 
IgnoreUnrecognizedVMOptions flag, so it’s now compatible with the new 
range/constraint check feature we put in recently. The current and 
desired/fixed behavior are:

current JDK behavior:
                                 exists, in range      exists, out of 
range   does not exist
                                 -XX:StackRedPages=1 
-XX:StackRedPages=0    -XX:THIS_FLAG_DOESNT_EXIST
-IgnoreUnrecognizedVMOptions           OK ERR                    ERR
+IgnoreUnrecognizedVMOptions           OK OK                     OK



desired/fixed JDK behavior:
                                 exists, in range      exists, out of 
range   does not exist
                                 -XX:StackRedPages=1 
-XX:StackRedPages=0    
-XX:THIS_FLAG_DOESNT_EXIST-IgnoreUnrecognizedVMOptions 
OK                    ERR                    ERR
+IgnoreUnrecognizedVMOptions          OK ERR                    OK


There was a brief email thread on this subject sometime ago 
http://mail.openjdk.java.net/pipermail/hotspot-dev/2015-June/019213.html 
and it was decided that we need a new flag that provides a better 
alternative - that effort is now tracked by 
https://bugs.openjdk.java.net/browse/JDK-8132545

Tested with test case from 
https://bugs.openjdk.java.net/browse/JDK-8130697, 
https://bugs.openjdk.java.net/browse/JDK-6886353 and via "JPRT 
testlist,noncolo.testlist -atk quick"


References:

    bug: https://bugs.openjdk.java.net/browse/JDK-8129855
webrev: http://cr.openjdk.java.net/~gziemski/8129855_rev0/


cheers