--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/ci/ciField.hpp Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,203 @@
+/*
+ * Copyright (c) 1999, 2013, 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_CI_CIFIELD_HPP
+#define SHARE_VM_CI_CIFIELD_HPP
+
+#include "ci/ciClassList.hpp"
+#include "ci/ciConstant.hpp"
+#include "ci/ciFlags.hpp"
+#include "ci/ciInstance.hpp"
+
+// ciField
+//
+// This class represents the result of a field lookup in the VM.
+// The lookup may not succeed, in which case the information in
+// the ciField will be incomplete.
+class ciField : public ResourceObj {
+ CI_PACKAGE_ACCESS
+ friend class ciEnv;
+ friend class ciInstanceKlass;
+
+private:
+ ciFlags _flags;
+ ciInstanceKlass* _holder;
+ ciSymbol* _name;
+ ciSymbol* _signature;
+ ciType* _type;
+ int _offset;
+ bool _is_constant;
+ ciMethod* _known_to_link_with_put;
+ ciInstanceKlass* _known_to_link_with_get;
+ ciConstant _constant_value;
+
+ ciType* compute_type();
+ ciType* compute_type_impl();
+
+ ciField(ciInstanceKlass* klass, int index);
+ ciField(fieldDescriptor* fd);
+
+ // shared constructor code
+ void initialize_from(fieldDescriptor* fd);
+
+public:
+ ciFlags flags() const { return _flags; }
+
+ // Of which klass is this field a member?
+ //
+ // Usage note: the declared holder of a field is the class
+ // referenced by name in the bytecodes. The canonical holder
+ // is the most general class which holds the field. This
+ // method returns the canonical holder. The declared holder
+ // can be accessed via a method in ciBytecodeStream.
+ //
+ // Ex.
+ // class A {
+ // public int f = 7;
+ // }
+ // class B extends A {
+ // public void test() {
+ // System.out.println(f);
+ // }
+ // }
+ //
+ // A java compiler is permitted to compile the access to
+ // field f as:
+ //
+ // getfield B.f
+ //
+ // In that case the declared holder of f would be B and
+ // the canonical holder of f would be A.
+ ciInstanceKlass* holder() const { return _holder; }
+
+ // Name of this field?
+ ciSymbol* name() const { return _name; }
+
+ // Signature of this field?
+ ciSymbol* signature() const { return _signature; }
+
+ // Of what type is this field?
+ ciType* type() { return (_type == NULL) ? compute_type() : _type; }
+
+ // How is this field actually stored in memory?
+ BasicType layout_type() { return type2field[(_type == NULL) ? T_OBJECT : _type->basic_type()]; }
+
+ // How big is this field in memory?
+ int size_in_bytes() { return type2aelembytes(layout_type()); }
+
+ // What is the offset of this field?
+ int offset() const {
+ assert(_offset >= 1, "illegal call to offset()");
+ return _offset;
+ }
+
+ // Same question, explicit units. (Fields are aligned to the byte level.)
+ int offset_in_bytes() const {
+ return offset();
+ }
+
+ // Is this field shared?
+ bool is_shared() {
+ // non-static fields of shared holders are cached
+ return _holder->is_shared() && !is_static();
+ }
+
+ // Is this field a constant?
+ //
+ // Clarification: A field is considered constant if:
+ // 1. The field is both static and final
+ // 2. The field is not one of the special static/final
+ // non-constant fields. These are java.lang.System.in
+ // and java.lang.System.out. Abomination.
+ //
+ // A field is also considered constant if
+ // - it is marked @Stable and is non-null (or non-zero, if a primitive) or
+ // - it is trusted or
+ // - it is the target field of a CallSite object.
+ //
+ // See ciField::initialize_from() for more details.
+ //
+ // A user should also check the field value (constant_value().is_valid()), since
+ // constant fields of non-initialized classes don't have values yet.
+ bool is_constant() const { return _is_constant; }
+
+ // Get the constant value of the static field.
+ ciConstant constant_value();
+
+ bool is_static_constant() {
+ return is_static() && is_constant() && constant_value().is_valid();
+ }
+
+ // Get the constant value of non-static final field in the given
+ // object.
+ ciConstant constant_value_of(ciObject* object);
+
+ // Check for link time errors. Accessing a field from a
+ // certain method via a certain bytecode may or may not be legal.
+ // This call checks to see if an exception may be raised by
+ // an access of this field.
+ //
+ // Usage note: if the same field is accessed multiple times
+ // in the same compilation, will_link will need to be checked
+ // at each point of access.
+ bool will_link(ciMethod* accessing_method,
+ Bytecodes::Code bc);
+
+ // Java access flags
+ bool is_public () const { return flags().is_public(); }
+ bool is_private () const { return flags().is_private(); }
+ bool is_protected () const { return flags().is_protected(); }
+ bool is_static () const { return flags().is_static(); }
+ bool is_final () const { return flags().is_final(); }
+ bool is_stable () const { return flags().is_stable(); }
+ bool is_volatile () const { return flags().is_volatile(); }
+ bool is_transient () const { return flags().is_transient(); }
+ // The field is modified outside of instance initializer methods
+ // (or class/initializer methods if the field is static).
+ bool has_initialized_final_update() const { return flags().has_initialized_final_update(); }
+
+ bool is_call_site_target() {
+ ciInstanceKlass* callsite_klass = CURRENT_ENV->CallSite_klass();
+ if (callsite_klass == NULL)
+ return false;
+ return (holder()->is_subclass_of(callsite_klass) && (name() == ciSymbol::target_name()));
+ }
+
+ bool is_autobox_cache() {
+ ciSymbol* klass_name = holder()->name();
+ return (name() == ciSymbol::cache_field_name() &&
+ holder()->uses_default_loader() &&
+ (klass_name == ciSymbol::java_lang_Character_CharacterCache() ||
+ klass_name == ciSymbol::java_lang_Byte_ByteCache() ||
+ klass_name == ciSymbol::java_lang_Short_ShortCache() ||
+ klass_name == ciSymbol::java_lang_Integer_IntegerCache() ||
+ klass_name == ciSymbol::java_lang_Long_LongCache()));
+ }
+
+ // Debugging output
+ void print();
+ void print_name_on(outputStream* st);
+};
+
+#endif // SHARE_VM_CI_CIFIELD_HPP