7086585: make Java field injection more flexible

Reviewed-by: jrose, twisti, kvn, coleenp

hotspot/src/share/vm/oops/fieldStreams.hpp

@@ -0,0 +1,174 @@
+/*
+ * Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#ifndef SHARE_VM_OOPS_FIELDSTREAMS_HPP
+#define SHARE_VM_OOPS_FIELDSTREAMS_HPP
+
+#include "oops/instanceKlass.hpp"
+#include "oops/fieldInfo.hpp"
+
+// The is the base class for iteration over the fields array
+// describing the declared fields in the class.  Several subclasses
+// are provided depending on the kind of iteration required.  The
+// JavaFieldStream is for iterating over regular Java fields and it
+// generally the preferred iterator.  InternalFieldStream only
+// iterates over fields that have been injected by the JVM.
+// AllFieldStream exposes all fields and should only be used in rare
+// cases.
+class FieldStreamBase : public StackObj {
+ protected:
+  typeArrayHandle     _fields;
+  constantPoolHandle  _constants;
+  int                 _index;
+  int                 _limit;
+
+  FieldInfo* field() const { return FieldInfo::from_field_array(_fields(), _index); }
+
+  FieldStreamBase(typeArrayHandle fields, constantPoolHandle constants, int start, int limit) {
+    _fields = fields;
+    _constants = constants;
+    _index = start;
+    _limit = limit;
+  }
+
+  FieldStreamBase(typeArrayHandle fields, constantPoolHandle constants) {
+    _fields = fields;
+    _constants = constants;
+    _index = 0;
+    _limit = fields->length() / FieldInfo::field_slots;
+  }
+
+ public:
+  FieldStreamBase(instanceKlass* klass) {
+    _fields = klass->fields();
+    _constants = klass->constants();
+    _index = 0;
+    _limit = klass->java_fields_count();
+  }
+  FieldStreamBase(instanceKlassHandle klass) {
+    _fields = klass->fields();
+    _constants = klass->constants();
+    _index = 0;
+    _limit = klass->java_fields_count();
+  }
+
+  // accessors
+  int index() const                 { return _index; }
+
+  void next() { _index += 1; }
+  bool done() const { return _index >= _limit; }
+
+  // Accessors for current field
+  AccessFlags access_flags() const {
+    AccessFlags flags;
+    flags.set_flags(field()->access_flags());
+    return flags;
+  }
+
+  void set_access_flags(u2 flags) const {
+    field()->set_access_flags(flags);
+  }
+
+  void set_access_flags(AccessFlags flags) const {
+    set_access_flags(flags.as_short());
+  }
+
+  Symbol* name() const {
+    return field()->name(_constants);
+  }
+
+  Symbol* signature() const {
+    return field()->signature(_constants);
+  }
+
+  Symbol* generic_signature() const {
+    return field()->generic_signature(_constants);
+  }
+
+  int offset() const {
+    return field()->offset();
+  }
+
+  void set_offset(int offset) {
+    field()->set_offset(offset);
+  }
+};
+
+// Iterate over only the internal fields
+class JavaFieldStream : public FieldStreamBase {
+ public:
+  JavaFieldStream(instanceKlass* k):      FieldStreamBase(k->fields(), k->constants(), 0, k->java_fields_count()) {}
+  JavaFieldStream(instanceKlassHandle k): FieldStreamBase(k->fields(), k->constants(), 0, k->java_fields_count()) {}
+
+  int name_index() const {
+    assert(!field()->is_internal(), "regular only");
+    return field()->name_index();
+  }
+  void set_name_index(int index) {
+    assert(!field()->is_internal(), "regular only");
+    field()->set_name_index(index);
+  }
+  int signature_index() const {
+    assert(!field()->is_internal(), "regular only");
+    return field()->signature_index();
+  }
+  void set_signature_index(int index) {
+    assert(!field()->is_internal(), "regular only");
+    field()->set_signature_index(index);
+  }
+  int generic_signature_index() const {
+    assert(!field()->is_internal(), "regular only");
+    return field()->generic_signature_index();
+  }
+  void set_generic_signature_index(int index) {
+    assert(!field()->is_internal(), "regular only");
+    field()->set_generic_signature_index(index);
+  }
+  int initval_index() const {
+    assert(!field()->is_internal(), "regular only");
+    return field()->initval_index();
+  }
+  void set_initval_index(int index) {
+    assert(!field()->is_internal(), "regular only");
+    return field()->set_initval_index(index);
+  }
+};
+
+
+// Iterate over only the internal fields
+class InternalFieldStream : public FieldStreamBase {
+ public:
+  InternalFieldStream(instanceKlass* k):      FieldStreamBase(k->fields(), k->constants(), k->java_fields_count(), k->all_fields_count()) {}
+  InternalFieldStream(instanceKlassHandle k): FieldStreamBase(k->fields(), k->constants(), k->java_fields_count(), k->all_fields_count()) {}
+};
+
+
+class AllFieldStream : public FieldStreamBase {
+ public:
+  AllFieldStream(typeArrayHandle fields, constantPoolHandle constants): FieldStreamBase(fields, constants) {}
+  AllFieldStream(instanceKlass* k):      FieldStreamBase(k->fields(), k->constants()) {}
+  AllFieldStream(instanceKlassHandle k): FieldStreamBase(k->fields(), k->constants()) {}
+};
+
+#endif // SHARE_VM_OOPS_FIELDSTREAMS_HPP