CODETOOLS-7902290 breaks all JTreg tests which use @requires vm.opt.*

[Volker Simonis]

Hi,

the change "CODETOOLS-7902290: introduce error state of @requires
properties" [1] which was recently pushed to the codetools repo,
breaks all JTreg tests which have a require clause that queries a non
final (i.e. no "vm.opt.final") VM option.

For example the test
"hotspot/jtreg/runtime/ReservedStack/ReservedStackTest.java" which
uses "@requires vm.opt.DeoptimizeALot != true" will now fail with:

test result: Error. Error evaluating expression: name not defined:
vm.opt.DeoptimizeALot

This is because
com.sun.javatest.regtest.config.RegressionContext.get() was changed to
return null instead of the string "null" for unknown properties.
Looking at requires.VMProps, I realized that "vm.opt.DeoptimizeALot"
is indeed not defined (as many other "vm.opt" properties, see below).
So it turns out that all the tests which @required a "vm.opt" option
did run in a faulty configuration until now.

I could for example easily fix
"hotspot/jtreg/runtime/ReservedStack/ReservedStackTest.java" by adding
the corresponding option in VMProps.java:

$ hg diff
diff -r 7a1e2d7ac55a test/jtreg-ext/requires/VMProps.java
--- a/test/jtreg-ext/requires/VMProps.java      Thu Oct 11 10:11:18 2018 -0400
+++ b/test/jtreg-ext/requires/VMProps.java      Thu Oct 11 18:51:37 2018 +0200
@@ -266,6 +266,8 @@
         vmOptFinalFlag(map, "ClassUnloading");
         vmOptFinalFlag(map, "UseCompressedOops");
         vmOptFinalFlag(map, "EnableJVMCI");
+        String value = String.valueOf(WB.getBooleanVMFlag("DeoptimizeALot"));
+        map.put("vm.opt.DeoptimizeALot", value);
     }

Following is a list of all "vm.opt" options used in @requires clauses
without being defined in VMProps.java:

vm.opt.AggressiveOpts
vm.opt.ClassUnloading
vm.opt.ClassUnloadingWithConcurrentMark
vm.opt.DeoptimizeALot
vm.opt.DisableExplicitGC
vm.opt.ExplicitGCInvokesConcurrent
vm.opt.FlightRecorder
vm.opt.G1HeapRegionSize
vm.opt.Inline
vm.opt.MaxGCPauseMillis
vm.opt.StartFlightRecording
vm.opt.SurvivorAlignmentInBytes
vm.opt.TieredCompilation
vm.opt.TieredStopAtLevel
vm.opt.TieredStopAtLevel==4)
vm.opt.TieredStopAtLevel==null
vm.opt.UseJVMCICompiler

What's the current plan? Do we want to add all these options in
VMProps.java? Or should we better add all the -XX VM options together
to VMProps such that they can all be freely used within @requires
clauses?

Thank you and best regards,
Volker

PS: I've noticed that there's "8209807: improve handling exception in
requires.VMProps" [2] to apparently adapt VMProps.java to
CODETOOLS-7902290 but I've tried the attached webrev and it doesn't
help with the described problem.

[1] https://bugs.openjdk.java.net/browse/CODETOOLS-7902290
[2] https://bugs.openjdk.java.net/browse/JDK-8209807