diff -r 4ebc2e2fb97c -r 71c04702a3d5 src/hotspot/share/ci/ciField.hpp --- /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