--- a/hotspot/src/share/vm/classfile/defaultMethods.cpp Mon Aug 26 09:33:01 2013 +0200
+++ b/hotspot/src/share/vm/classfile/defaultMethods.cpp Mon Aug 26 11:35:25 2013 -0400
@@ -25,7 +25,6 @@
#include "precompiled.hpp"
#include "classfile/bytecodeAssembler.hpp"
#include "classfile/defaultMethods.hpp"
-#include "classfile/genericSignatures.hpp"
#include "classfile/symbolTable.hpp"
#include "memory/allocation.hpp"
#include "memory/metadataFactory.hpp"
@@ -75,14 +74,6 @@
}
};
-class ContextMark : public PseudoScopeMark {
- private:
- generic::Context::Mark _mark;
- public:
- ContextMark(const generic::Context::Mark& cm) : _mark(cm) {}
- virtual void destroy() { _mark.destroy(); }
-};
-
#ifndef PRODUCT
static void print_slot(outputStream* str, Symbol* name, Symbol* signature) {
ResourceMark rm;
@@ -503,38 +494,6 @@
return SymbolTable::new_symbol(ss.base(), (int)ss.size(), CHECK_NULL);
}
-// A generic method family contains a set of all methods that implement a single
-// language-level method. Because of erasure, these methods may have different
-// signatures. As members of the set are collected while walking over the
-// hierarchy, they are tagged with a qualification state. The qualification
-// state for an erased method is set to disqualified if there exists a path
-// from the root of hierarchy to the method that contains an interleaving
-// language-equivalent method defined in an interface.
-class GenericMethodFamily : public MethodFamily {
- private:
-
- generic::MethodDescriptor* _descriptor; // language-level description
-
- public:
-
- GenericMethodFamily(generic::MethodDescriptor* canonical_desc)
- : _descriptor(canonical_desc) {}
-
- generic::MethodDescriptor* descriptor() const { return _descriptor; }
-
- bool descriptor_matches(generic::MethodDescriptor* md, generic::Context* ctx) {
- return descriptor()->covariant_match(md, ctx);
- }
-
-#ifndef PRODUCT
- Symbol* get_generic_sig() const {
-
- generic::Context ctx(NULL); // empty, as _descriptor already canonicalized
- TempNewSymbol sig = descriptor()->reify_signature(&ctx, Thread::current());
- return sig;
- }
-#endif // ndef PRODUCT
-};
class StateRestorer;
@@ -571,26 +530,6 @@
StateRestorer* record_method_and_dq_further(Method* mo);
};
-
-// StatefulGenericMethodFamily is a wrapper around GenericMethodFamily that maintains the
-// qualification state during hierarchy visitation, and applies that state
-// when adding members to the GenericMethodFamily.
-class StatefulGenericMethodFamily : public StatefulMethodFamily {
-
- public:
- StatefulGenericMethodFamily(generic::MethodDescriptor* md, generic::Context* ctx)
- : StatefulMethodFamily(new GenericMethodFamily(md->canonicalize(ctx))) {
-
- }
- GenericMethodFamily* get_method_family() {
- return (GenericMethodFamily*)_method_family;
- }
-
- bool descriptor_matches(generic::MethodDescriptor* md, generic::Context* ctx) {
- return get_method_family()->descriptor_matches(md, ctx);
- }
-};
-
class StateRestorer : public PseudoScopeMark {
private:
StatefulMethodFamily* _method;
@@ -616,39 +555,6 @@
return mark;
}
-class StatefulGenericMethodFamilies : public ResourceObj {
- private:
- GrowableArray<StatefulGenericMethodFamily*> _methods;
-
- public:
- StatefulGenericMethodFamily* find_matching(
- generic::MethodDescriptor* md, generic::Context* ctx) {
- for (int i = 0; i < _methods.length(); ++i) {
- StatefulGenericMethodFamily* existing = _methods.at(i);
- if (existing->descriptor_matches(md, ctx)) {
- return existing;
- }
- }
- return NULL;
- }
-
- StatefulGenericMethodFamily* find_matching_or_create(
- generic::MethodDescriptor* md, generic::Context* ctx) {
- StatefulGenericMethodFamily* method = find_matching(md, ctx);
- if (method == NULL) {
- method = new StatefulGenericMethodFamily(md, ctx);
- _methods.append(method);
- }
- return method;
- }
-
- void extract_families_into(GrowableArray<GenericMethodFamily*>* array) {
- for (int i = 0; i < _methods.length(); ++i) {
- array->append(_methods.at(i)->get_method_family());
- }
- }
-};
-
// Represents a location corresponding to a vtable slot for methods that
// neither the class nor any of it's ancestors provide an implementaion.
// Default methods may be present to fill this slot.
@@ -779,146 +685,11 @@
};
-// Iterates over the type hierarchy looking for all methods with a specific
-// method name. The result of this is a set of method families each of
-// which is populated with a set of methods that implement the same
-// language-level signature.
-class FindMethodsByGenericSig : public HierarchyVisitor<FindMethodsByGenericSig> {
- private:
- // Context data
- Thread* THREAD;
- generic::DescriptorCache* _cache;
- Symbol* _method_name;
- generic::Context* _ctx;
- StatefulGenericMethodFamilies _families;
- public:
-
- FindMethodsByGenericSig(generic::DescriptorCache* cache, Symbol* name,
- generic::Context* ctx, Thread* thread) :
- _cache(cache), _method_name(name), _ctx(ctx), THREAD(thread) {}
-
- void get_discovered_families(GrowableArray<GenericMethodFamily*>* methods) {
- _families.extract_families_into(methods);
- }
-
- void* new_node_data(InstanceKlass* cls) { return new PseudoScope(); }
- void free_node_data(void* node_data) {
- PseudoScope::cast(node_data)->destroy();
- }
-
- bool visit() {
- PseudoScope* scope = PseudoScope::cast(current_data());
- InstanceKlass* klass = current_class();
- InstanceKlass* sub = current_depth() > 0 ? class_at_depth(1) : NULL;
-
- ContextMark* cm = new ContextMark(_ctx->mark());
- scope->add_mark(cm); // will restore context when scope is freed
-
- _ctx->apply_type_arguments(sub, klass, THREAD);
-
- int start, end = 0;
- start = klass->find_method_by_name(_method_name, &end);
- if (start != -1) {
- for (int i = start; i < end; ++i) {
- Method* m = klass->methods()->at(i);
- // This gets the method's parameter list with its generic type
- // parameters resolved
- generic::MethodDescriptor* md = _cache->descriptor_for(m, THREAD);
-
- // Find all methods on this hierarchy that match this method
- // (name, signature). This class collects other families of this
- // method name.
- StatefulGenericMethodFamily* family =
- _families.find_matching_or_create(md, _ctx);
-
- if (klass->is_interface()) {
- // ???
- StateRestorer* restorer = family->record_method_and_dq_further(m);
- scope->add_mark(restorer);
- } else {
- // This is the rule that methods in classes "win" (bad word) over
- // methods in interfaces. This works because of single inheritance
- family->set_target_if_empty(m);
- }
- }
- }
- return true;
- }
-};
-
-#ifndef PRODUCT
-static void print_generic_families(
- GrowableArray<GenericMethodFamily*>* methods, Symbol* match) {
- streamIndentor si(tty, 4);
- if (methods->length() == 0) {
- tty->indent();
- tty->print_cr("No Logical Method found");
- }
- for (int i = 0; i < methods->length(); ++i) {
- tty->indent();
- GenericMethodFamily* lm = methods->at(i);
- if (lm->contains_signature(match)) {
- tty->print_cr("<Matching>");
- } else {
- tty->print_cr("<Non-Matching>");
- }
- lm->print_sig_on(tty, lm->get_generic_sig(), 1);
- }
-}
-#endif // ndef PRODUCT
static void create_overpasses(
GrowableArray<EmptyVtableSlot*>* slots, InstanceKlass* klass, TRAPS);
-static void generate_generic_defaults(
- InstanceKlass* klass, GrowableArray<EmptyVtableSlot*>* empty_slots,
- EmptyVtableSlot* slot, int current_slot_index, TRAPS) {
-
- if (slot->is_bound()) {
-#ifndef PRODUCT
- if (TraceDefaultMethods) {
- streamIndentor si(tty, 4);
- tty->indent().print_cr("Already bound to logical method:");
- GenericMethodFamily* lm = (GenericMethodFamily*)(slot->get_binding());
- lm->print_sig_on(tty, lm->get_generic_sig(), 1);
- }
-#endif // ndef PRODUCT
- return; // covered by previous processing
- }
-
- generic::DescriptorCache cache;
-
- generic::Context ctx(&cache);
- FindMethodsByGenericSig visitor(&cache, slot->name(), &ctx, CHECK);
- visitor.run(klass);
-
- GrowableArray<GenericMethodFamily*> discovered_families;
- visitor.get_discovered_families(&discovered_families);
-
-#ifndef PRODUCT
- if (TraceDefaultMethods) {
- print_generic_families(&discovered_families, slot->signature());
- }
-#endif // ndef PRODUCT
-
- // Find and populate any other slots that match the discovered families
- for (int j = current_slot_index; j < empty_slots->length(); ++j) {
- EmptyVtableSlot* open_slot = empty_slots->at(j);
-
- if (slot->name() == open_slot->name()) {
- for (int k = 0; k < discovered_families.length(); ++k) {
- GenericMethodFamily* lm = discovered_families.at(k);
-
- if (lm->contains_signature(open_slot->signature())) {
- lm->determine_target(klass, CHECK);
- open_slot->bind_family(lm);
- }
- }
- }
- }
-}
-
static void generate_erased_defaults(
InstanceKlass* klass, GrowableArray<EmptyVtableSlot*>* empty_slots,
EmptyVtableSlot* slot, TRAPS) {
@@ -943,21 +714,14 @@
//
// First if finds any name/signature slots that need any implementation (either
// because they are miranda or a superclass's implementation is an overpass
-// itself). For each slot, iterate over the hierarchy, using generic signature
-// information to partition any methods that match the name into method families
-// where each family contains methods whose signatures are equivalent at the
-// language level (i.e., their reified parameters match and return values are
-// covariant). Check those sets to see if they contain a signature that matches
-// the slot we're looking at (if we're lucky, there might be other empty slots
-// that we can fill using the same analysis).
+// itself). For each slot, iterate over the hierarchy, to see if they contain a
+// signature that matches the slot we are looking at.
//
// For each slot filled, we generate an overpass method that either calls the
// unique default method candidate using invokespecial, or throws an exception
// (in the case of no default method candidates, or more than one valid
-// candidate). These methods are then added to the class's method list. If
-// the method set we're using contains methods (qualified or not) with a
-// different runtime signature than the method we're creating, then we have to
-// create bridges with those signatures too.
+// candidate). These methods are then added to the class's method list.
+// The JVM does not create bridges nor handle generic signatures here.
void DefaultMethods::generate_default_methods(
InstanceKlass* klass, GrowableArray<Method*>* mirandas, TRAPS) {
@@ -997,11 +761,7 @@
}
#endif // ndef PRODUCT
- if (ParseGenericDefaults) {
- generate_generic_defaults(klass, empty_slots, slot, i, CHECK);
- } else {
- generate_erased_defaults(klass, empty_slots, slot, CHECK);
- }
+ generate_erased_defaults(klass, empty_slots, slot, CHECK);
}
#ifndef PRODUCT
if (TraceDefaultMethods) {
@@ -1019,13 +779,13 @@
}
/**
- * Generic analysis was used upon interface '_target' and found a unique
- * default method candidate with generic signature '_method_desc'. This
+ * Interface inheritance rules were used to find a unique default method
+ * candidate for the resolved class. This
* method is only viable if it would also be in the set of default method
* candidates if we ran a full analysis on the current class.
*
* The only reason that the method would not be in the set of candidates for
- * the current class is if that there's another covariantly matching method
+ * the current class is if that there's another matching method
* which is "more specific" than the found method -- i.e., one could find a
* path in the interface hierarchy in which the matching method appears
* before we get to '_target'.
@@ -1110,48 +870,6 @@
: ShadowChecker(thread, name, holder, target) {}
};
-class GenericShadowChecker : public ShadowChecker {
- private:
- generic::DescriptorCache* _cache;
- generic::MethodDescriptor* _method_desc;
-
- bool path_has_shadow() {
- generic::Context ctx(_cache);
-
- for (int i = current_depth() - 1; i > 0; --i) {
- InstanceKlass* ik = class_at_depth(i);
- InstanceKlass* sub = class_at_depth(i + 1);
- ctx.apply_type_arguments(sub, ik, THREAD);
-
- if (ik->is_interface()) {
- int end;
- int start = ik->find_method_by_name(_method_name, &end);
- if (start != -1) {
- for (int j = start; j < end; ++j) {
- Method* mo = ik->methods()->at(j);
- generic::MethodDescriptor* md = _cache->descriptor_for(mo, THREAD);
- if (_method_desc->covariant_match(md, &ctx)) {
- return true;
- }
- }
- }
- }
- }
- return false;
- }
-
- public:
-
- GenericShadowChecker(generic::DescriptorCache* cache, Thread* thread,
- Symbol* name, InstanceKlass* holder, generic::MethodDescriptor* desc,
- InstanceKlass* target)
- : ShadowChecker(thread, name, holder, target) {
- _cache = cache;
- _method_desc = desc;
- }
-};
-
-
// Find the unique qualified candidate from the perspective of the super_class
// which is the resolved_klass, which must be an immediate superinterface
@@ -1203,66 +921,6 @@
}
}
-// super_class is assumed to be the direct super of current_class
-Method* find_generic_super_default( InstanceKlass* current_class,
- InstanceKlass* super_class,
- Symbol* method_name, Symbol* sig, TRAPS) {
- generic::DescriptorCache cache;
- generic::Context ctx(&cache);
-
- // Prime the initial generic context for current -> super_class
- ctx.apply_type_arguments(current_class, super_class, CHECK_NULL);
-
- FindMethodsByGenericSig visitor(&cache, method_name, &ctx, CHECK_NULL);
- visitor.run(super_class);
-
- GrowableArray<GenericMethodFamily*> families;
- visitor.get_discovered_families(&families);
-
-#ifndef PRODUCT
- if (TraceDefaultMethods) {
- print_generic_families(&families, sig);
- }
-#endif // ndef PRODUCT
-
- GenericMethodFamily* selected_family = NULL;
-
- for (int i = 0; i < families.length(); ++i) {
- GenericMethodFamily* lm = families.at(i);
- if (lm->contains_signature(sig)) {
- lm->determine_target(current_class, CHECK_NULL);
- selected_family = lm;
- }
- }
-
- if (selected_family->has_target()) {
- Method* target = selected_family->get_selected_target();
- InstanceKlass* holder = InstanceKlass::cast(target->method_holder());
-
- // Verify that the identified method is valid from the context of
- // the current class
- GenericShadowChecker checker(&cache, THREAD, target->name(),
- holder, selected_family->descriptor(), super_class);
- checker.run(current_class);
-
- if (checker.found_shadow()) {
-#ifndef PRODUCT
- if (TraceDefaultMethods) {
- tty->print_cr(" Only candidate found was shadowed.");
- }
-#endif // ndef PRODUCT
- THROW_MSG_(vmSymbols::java_lang_AbstractMethodError(),
- "Accessible default method not found", NULL);
- } else {
- return target;
- }
- } else {
- assert(selected_family->throws_exception(), "must have target or throw");
- THROW_MSG_(vmSymbols::java_lang_AbstractMethodError(),
- selected_family->get_exception_message()->as_C_string(), NULL);
- }
-}
-
// This is called during linktime when we find an invokespecial call that
// refers to a direct superinterface. It indicates that we should find the
// default method in the hierarchy of that superinterface, and if that method
@@ -1296,13 +954,8 @@
assert(super_class->is_interface(), "only call for default methods");
Method* target = NULL;
- if (ParseGenericDefaults) {
- target = find_generic_super_default(current_class, super_class,
- method_name, sig, CHECK_NULL);
- } else {
- target = find_erased_super_default(current_class, super_class,
- method_name, sig, CHECK_NULL);
- }
+ target = find_erased_super_default(current_class, super_class,
+ method_name, sig, CHECK_NULL);
#ifndef PRODUCT
if (target != NULL) {