diff -r 9f471b837330 -r 69de8357bc53 hotspot/src/share/vm/oops/klassVtable.cpp --- a/hotspot/src/share/vm/oops/klassVtable.cpp Mon Jul 14 12:43:50 2014 +0400 +++ b/hotspot/src/share/vm/oops/klassVtable.cpp Wed May 07 19:21:52 2014 +0400 @@ -251,6 +251,17 @@ // For bytecodes not produced by javac together it is possible that a method does not override // the superclass's method, but might indirectly override a super-super class's vtable entry // If none found, return a null superk, else return the superk of the method this does override +// For public and protected methods: if they override a superclass, they will +// also be overridden themselves appropriately. +// Private methods do not override and are not overridden. +// Package Private methods are trickier: +// e.g. P1.A, pub m +// P2.B extends A, package private m +// P1.C extends B, public m +// P1.C.m needs to override P1.A.m and can not override P2.B.m +// Therefore: all package private methods need their own vtable entries for +// them to be the root of an inheritance overriding decision +// Package private methods may also override other vtable entries InstanceKlass* klassVtable::find_transitive_override(InstanceKlass* initialsuper, methodHandle target_method, int vtable_index, Handle target_loader, Symbol* target_classname, Thread * THREAD) { InstanceKlass* superk = initialsuper; @@ -398,8 +409,11 @@ target_classname, THREAD)) != (InstanceKlass*)NULL)))) { - // overriding, so no new entry - allocate_new = false; + // Package private methods always need a new entry to root their own + // overriding. They may also override other methods. + if (!target_method()->is_package_private()) { + allocate_new = false; + } if (checkconstraints) { // Override vtable entry if passes loader constraint check @@ -543,8 +557,9 @@ AccessFlags class_flags, TRAPS) { if (class_flags.is_interface()) { - // Interfaces do not use vtables, so there is no point to assigning - // a vtable index to any of their methods. If we refrain from doing this, + // Interfaces do not use vtables, except for java.lang.Object methods, + // so there is no point to assigning + // a vtable index to any of their local methods. If we refrain from doing this, // we can use Method::_vtable_index to hold the itable index return false; } @@ -582,6 +597,12 @@ return true; } + // Package private methods always need a new entry to root their own + // overriding. This allows transitive overriding to work. + if (target_method()->is_package_private()) { + return true; + } + // search through the super class hierarchy to see if we need // a new entry ResourceMark rm;