1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/vm/ci/ciField.hpp Sat Dec 01 00:00:00 2007 +0000
1.3 @@ -0,0 +1,168 @@
1.4 +/*
1.5 + * Copyright 1999-2006 Sun Microsystems, Inc. All Rights Reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation.
1.11 + *
1.12 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.13 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.14 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.15 + * version 2 for more details (a copy is included in the LICENSE file that
1.16 + * accompanied this code).
1.17 + *
1.18 + * You should have received a copy of the GNU General Public License version
1.19 + * 2 along with this work; if not, write to the Free Software Foundation,
1.20 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.21 + *
1.22 + * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
1.23 + * CA 95054 USA or visit www.sun.com if you need additional information or
1.24 + * have any questions.
1.25 + *
1.26 + */
1.27 +
1.28 +// ciField
1.29 +//
1.30 +// This class represents the result of a field lookup in the VM.
1.31 +// The lookup may not succeed, in which case the information in
1.32 +// the ciField will be incomplete.
1.33 +class ciField : public ResourceObj {
1.34 + CI_PACKAGE_ACCESS
1.35 + friend class ciEnv;
1.36 + friend class ciInstanceKlass;
1.37 + friend class NonStaticFieldFiller;
1.38 +
1.39 +private:
1.40 + ciFlags _flags;
1.41 + ciInstanceKlass* _holder;
1.42 + ciSymbol* _name;
1.43 + ciSymbol* _signature;
1.44 + ciType* _type;
1.45 + int _offset;
1.46 + bool _is_constant;
1.47 + ciInstanceKlass* _known_to_link_with;
1.48 + ciConstant _constant_value;
1.49 +
1.50 + // Used for will_link
1.51 + int _cp_index;
1.52 +
1.53 + ciType* compute_type();
1.54 + ciType* compute_type_impl();
1.55 +
1.56 + ciField(ciInstanceKlass* klass, int index);
1.57 + ciField(fieldDescriptor* fd);
1.58 +
1.59 + // shared constructor code
1.60 + void initialize_from(fieldDescriptor* fd);
1.61 +
1.62 + // The implementation of the print method.
1.63 + void print_impl(outputStream* st);
1.64 +
1.65 +public:
1.66 + ciFlags flags() { return _flags; }
1.67 +
1.68 + // Of which klass is this field a member?
1.69 + //
1.70 + // Usage note: the declared holder of a field is the class
1.71 + // referenced by name in the bytecodes. The canonical holder
1.72 + // is the most general class which holds the field. This
1.73 + // method returns the canonical holder. The declared holder
1.74 + // can be accessed via a method in ciBytecodeStream.
1.75 + //
1.76 + // Ex.
1.77 + // class A {
1.78 + // public int f = 7;
1.79 + // }
1.80 + // class B extends A {
1.81 + // public void test() {
1.82 + // System.out.println(f);
1.83 + // }
1.84 + // }
1.85 + //
1.86 + // A java compiler is permitted to compile the access to
1.87 + // field f as:
1.88 + //
1.89 + // getfield B.f
1.90 + //
1.91 + // In that case the declared holder of f would be B and
1.92 + // the canonical holder of f would be A.
1.93 + ciInstanceKlass* holder() { return _holder; }
1.94 +
1.95 + // Name of this field?
1.96 + ciSymbol* name() { return _name; }
1.97 +
1.98 + // Signature of this field?
1.99 + ciSymbol* signature() { return _signature; }
1.100 +
1.101 + // Of what type is this field?
1.102 + ciType* type() { return (_type == NULL) ? compute_type() : _type; }
1.103 +
1.104 + // How is this field actually stored in memory?
1.105 + BasicType layout_type() { return type2field[(_type == NULL) ? T_OBJECT : _type->basic_type()]; }
1.106 +
1.107 + // How big is this field in memory?
1.108 + int size_in_bytes() { return type2aelembytes[layout_type()]; }
1.109 +
1.110 + // What is the offset of this field?
1.111 + int offset() {
1.112 + assert(_offset >= 1, "illegal call to offset()");
1.113 + return _offset;
1.114 + }
1.115 +
1.116 + // Same question, explicit units. (Fields are aligned to the byte level.)
1.117 + int offset_in_bytes() {
1.118 + return offset();
1.119 + }
1.120 +
1.121 + // Is this field shared?
1.122 + bool is_shared() {
1.123 + // non-static fields of shared holders are cached
1.124 + return _holder->is_shared() && !is_static();
1.125 + }
1.126 +
1.127 + // Is this field a constant?
1.128 + //
1.129 + // Clarification: A field is considered constant if:
1.130 + // 1. The field is both static and final
1.131 + // 2. The canonical holder of the field has undergone
1.132 + // static initialization.
1.133 + // 3. If the field is an object or array, then the oop
1.134 + // in question is allocated in perm space.
1.135 + // 4. The field is not one of the special static/final
1.136 + // non-constant fields. These are java.lang.System.in
1.137 + // and java.lang.System.out. Abomination.
1.138 + //
1.139 + // Note: the check for case 4 is not yet implemented.
1.140 + bool is_constant() { return _is_constant; }
1.141 +
1.142 + // Get the constant value of this field.
1.143 + ciConstant constant_value() {
1.144 + assert(is_constant(), "illegal call to constant_value()");
1.145 + return _constant_value;
1.146 + }
1.147 +
1.148 + // Check for link time errors. Accessing a field from a
1.149 + // certain class via a certain bytecode may or may not be legal.
1.150 + // This call checks to see if an exception may be raised by
1.151 + // an access of this field.
1.152 + //
1.153 + // Usage note: if the same field is accessed multiple times
1.154 + // in the same compilation, will_link will need to be checked
1.155 + // at each point of access.
1.156 + bool will_link(ciInstanceKlass* accessing_klass,
1.157 + Bytecodes::Code bc);
1.158 +
1.159 + // Java access flags
1.160 + bool is_public () { return flags().is_public(); }
1.161 + bool is_private () { return flags().is_private(); }
1.162 + bool is_protected () { return flags().is_protected(); }
1.163 + bool is_static () { return flags().is_static(); }
1.164 + bool is_final () { return flags().is_final(); }
1.165 + bool is_volatile () { return flags().is_volatile(); }
1.166 + bool is_transient () { return flags().is_transient(); }
1.167 +
1.168 + // Debugging output
1.169 + void print();
1.170 + void print_name_on(outputStream* st);
1.171 +};
