Mercurial > hg > graal-jvmci-8
diff src/share/vm/ci/ciField.hpp @ 0:a61af66fc99e jdk7-b24
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author | duke |
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date | Sat, 01 Dec 2007 00:00:00 +0000 |
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children | d5fc211aea19 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/share/vm/ci/ciField.hpp Sat Dec 01 00:00:00 2007 +0000 @@ -0,0 +1,168 @@ +/* + * Copyright 1999-2006 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, + * CA 95054 USA or visit www.sun.com if you need additional information or + * have any questions. + * + */ + +// 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; + friend class NonStaticFieldFiller; + +private: + ciFlags _flags; + ciInstanceKlass* _holder; + ciSymbol* _name; + ciSymbol* _signature; + ciType* _type; + int _offset; + bool _is_constant; + ciInstanceKlass* _known_to_link_with; + ciConstant _constant_value; + + // Used for will_link + int _cp_index; + + ciType* compute_type(); + ciType* compute_type_impl(); + + ciField(ciInstanceKlass* klass, int index); + ciField(fieldDescriptor* fd); + + // shared constructor code + void initialize_from(fieldDescriptor* fd); + + // The implementation of the print method. + void print_impl(outputStream* st); + +public: + ciFlags flags() { 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() { return _holder; } + + // Name of this field? + ciSymbol* name() { return _name; } + + // Signature of this field? + ciSymbol* signature() { 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() { + assert(_offset >= 1, "illegal call to offset()"); + return _offset; + } + + // Same question, explicit units. (Fields are aligned to the byte level.) + int offset_in_bytes() { + 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 canonical holder of the field has undergone + // static initialization. + // 3. If the field is an object or array, then the oop + // in question is allocated in perm space. + // 4. 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. + // + // Note: the check for case 4 is not yet implemented. + bool is_constant() { return _is_constant; } + + // Get the constant value of this field. + ciConstant constant_value() { + assert(is_constant(), "illegal call to constant_value()"); + return _constant_value; + } + + // Check for link time errors. Accessing a field from a + // certain class 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(ciInstanceKlass* accessing_klass, + Bytecodes::Code bc); + + // Java access flags + bool is_public () { return flags().is_public(); } + bool is_private () { return flags().is_private(); } + bool is_protected () { return flags().is_protected(); } + bool is_static () { return flags().is_static(); } + bool is_final () { return flags().is_final(); } + bool is_volatile () { return flags().is_volatile(); } + bool is_transient () { return flags().is_transient(); } + + // Debugging output + void print(); + void print_name_on(outputStream* st); +};