over-eager verification

Tue Mar 5 10:15:00 GMT 2002

>>>>> "Per" == Per Bothner <per@bothner.com> writes:

Per> We should verify a method the first time it is invoked, not when
Per> its class is prepared, since since most methods will never get
Per> called.
I don't think we can do this. See JVM Spec Section 4.9.1, Pass 3:
 Still during linking, the verifier checks the code array of the
 Code attribute for each method of the class file by performing
 data-flow analysis on each method.
So it explicitly requires checking during preparation and not at
invocation.
Per> (Actually, ideally verfication should be done in conjunction with
Per> JIT-compilation, since a JIT will need the type information that
Per> the verifier has recoved.)
This seems unlikely given our desire for modularity, and also that the
first JIT will most likely be ORP, which as far as I could see has no
way of feeding it this info.
Tom