Wed, 06 Jan 2010 14:22:39 -0800
6914300: ciEnv should export all well known classes
Reviewed-by: kvn, twisti
duke@435 | 1 | /* |
twisti@1573 | 2 | * Copyright 1999-2009 Sun Microsystems, Inc. All Rights Reserved. |
duke@435 | 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
duke@435 | 4 | * |
duke@435 | 5 | * This code is free software; you can redistribute it and/or modify it |
duke@435 | 6 | * under the terms of the GNU General Public License version 2 only, as |
duke@435 | 7 | * published by the Free Software Foundation. |
duke@435 | 8 | * |
duke@435 | 9 | * This code is distributed in the hope that it will be useful, but WITHOUT |
duke@435 | 10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
duke@435 | 11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
duke@435 | 12 | * version 2 for more details (a copy is included in the LICENSE file that |
duke@435 | 13 | * accompanied this code). |
duke@435 | 14 | * |
duke@435 | 15 | * You should have received a copy of the GNU General Public License version |
duke@435 | 16 | * 2 along with this work; if not, write to the Free Software Foundation, |
duke@435 | 17 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
duke@435 | 18 | * |
duke@435 | 19 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
duke@435 | 20 | * CA 95054 USA or visit www.sun.com if you need additional information or |
duke@435 | 21 | * have any questions. |
duke@435 | 22 | * |
duke@435 | 23 | */ |
duke@435 | 24 | |
duke@435 | 25 | #include "incls/_precompiled.incl" |
duke@435 | 26 | #include "incls/_ciField.cpp.incl" |
duke@435 | 27 | |
duke@435 | 28 | // ciField |
duke@435 | 29 | // |
duke@435 | 30 | // This class represents the result of a field lookup in the VM. |
duke@435 | 31 | // The lookup may not succeed, in which case the information in |
duke@435 | 32 | // the ciField will be incomplete. |
duke@435 | 33 | |
duke@435 | 34 | // The ciObjectFactory cannot create circular data structures in one query. |
duke@435 | 35 | // To avoid vicious circularities, we initialize ciField::_type to NULL |
duke@435 | 36 | // for reference types and derive it lazily from the ciField::_signature. |
duke@435 | 37 | // Primitive types are eagerly initialized, and basic layout queries |
duke@435 | 38 | // can succeed without initialization, using only the BasicType of the field. |
duke@435 | 39 | |
duke@435 | 40 | // Notes on bootstrapping and shared CI objects: A field is shared if and |
duke@435 | 41 | // only if it is (a) non-static and (b) declared by a shared instance klass. |
duke@435 | 42 | // This allows non-static field lists to be cached on shared types. |
duke@435 | 43 | // Because the _type field is lazily initialized, however, there is a |
duke@435 | 44 | // special restriction that a shared field cannot cache an unshared type. |
duke@435 | 45 | // This puts a small performance penalty on shared fields with unshared |
duke@435 | 46 | // types, such as StackTraceElement[] Throwable.stackTrace. |
duke@435 | 47 | // (Throwable is shared because ClassCastException is shared, but |
duke@435 | 48 | // StackTraceElement is not presently shared.) |
duke@435 | 49 | |
duke@435 | 50 | // It is not a vicious circularity for a ciField to recursively create |
duke@435 | 51 | // the ciSymbols necessary to represent its name and signature. |
duke@435 | 52 | // Therefore, these items are created eagerly, and the name and signature |
duke@435 | 53 | // of a shared field are themselves shared symbols. This somewhat |
duke@435 | 54 | // pollutes the set of shared CI objects: It grows from 50 to 93 items, |
duke@435 | 55 | // with all of the additional 43 being uninteresting shared ciSymbols. |
duke@435 | 56 | // This adds at most one step to the binary search, an amount which |
duke@435 | 57 | // decreases for complex compilation tasks. |
duke@435 | 58 | |
duke@435 | 59 | // ------------------------------------------------------------------ |
duke@435 | 60 | // ciField::ciField |
duke@435 | 61 | ciField::ciField(ciInstanceKlass* klass, int index): _known_to_link_with(NULL) { |
duke@435 | 62 | ASSERT_IN_VM; |
duke@435 | 63 | CompilerThread *thread = CompilerThread::current(); |
duke@435 | 64 | |
duke@435 | 65 | assert(ciObjectFactory::is_initialized(), "not a shared field"); |
duke@435 | 66 | |
duke@435 | 67 | assert(klass->get_instanceKlass()->is_linked(), "must be linked before using its constan-pool"); |
duke@435 | 68 | |
duke@435 | 69 | _cp_index = index; |
duke@435 | 70 | constantPoolHandle cpool(thread, klass->get_instanceKlass()->constants()); |
duke@435 | 71 | |
duke@435 | 72 | // Get the field's name, signature, and type. |
duke@435 | 73 | symbolHandle name (thread, cpool->name_ref_at(index)); |
duke@435 | 74 | _name = ciEnv::current(thread)->get_object(name())->as_symbol(); |
duke@435 | 75 | |
duke@435 | 76 | int nt_index = cpool->name_and_type_ref_index_at(index); |
duke@435 | 77 | int sig_index = cpool->signature_ref_index_at(nt_index); |
duke@435 | 78 | symbolHandle signature (thread, cpool->symbol_at(sig_index)); |
duke@435 | 79 | _signature = ciEnv::current(thread)->get_object(signature())->as_symbol(); |
duke@435 | 80 | |
duke@435 | 81 | BasicType field_type = FieldType::basic_type(signature()); |
duke@435 | 82 | |
duke@435 | 83 | // If the field is a pointer type, get the klass of the |
duke@435 | 84 | // field. |
duke@435 | 85 | if (field_type == T_OBJECT || field_type == T_ARRAY) { |
duke@435 | 86 | bool ignore; |
duke@435 | 87 | // This is not really a class reference; the index always refers to the |
duke@435 | 88 | // field's type signature, as a symbol. Linkage checks do not apply. |
twisti@1573 | 89 | _type = ciEnv::current(thread)->get_klass_by_index(cpool, sig_index, ignore, klass); |
duke@435 | 90 | } else { |
duke@435 | 91 | _type = ciType::make(field_type); |
duke@435 | 92 | } |
duke@435 | 93 | |
duke@435 | 94 | _name = (ciSymbol*)ciEnv::current(thread)->get_object(name()); |
duke@435 | 95 | |
duke@435 | 96 | // Get the field's declared holder. |
duke@435 | 97 | // |
duke@435 | 98 | // Note: we actually create a ciInstanceKlass for this klass, |
duke@435 | 99 | // even though we may not need to. |
duke@435 | 100 | int holder_index = cpool->klass_ref_index_at(index); |
duke@435 | 101 | bool holder_is_accessible; |
duke@435 | 102 | ciInstanceKlass* declared_holder = |
twisti@1573 | 103 | ciEnv::current(thread)->get_klass_by_index(cpool, holder_index, |
twisti@1573 | 104 | holder_is_accessible, |
twisti@1573 | 105 | klass)->as_instance_klass(); |
duke@435 | 106 | |
duke@435 | 107 | // The declared holder of this field may not have been loaded. |
duke@435 | 108 | // Bail out with partial field information. |
duke@435 | 109 | if (!holder_is_accessible) { |
duke@435 | 110 | // _cp_index and _type have already been set. |
duke@435 | 111 | // The default values for _flags and _constant_value will suffice. |
duke@435 | 112 | // We need values for _holder, _offset, and _is_constant, |
duke@435 | 113 | _holder = declared_holder; |
duke@435 | 114 | _offset = -1; |
duke@435 | 115 | _is_constant = false; |
duke@435 | 116 | return; |
duke@435 | 117 | } |
duke@435 | 118 | |
duke@435 | 119 | instanceKlass* loaded_decl_holder = declared_holder->get_instanceKlass(); |
duke@435 | 120 | |
duke@435 | 121 | // Perform the field lookup. |
duke@435 | 122 | fieldDescriptor field_desc; |
duke@435 | 123 | klassOop canonical_holder = |
duke@435 | 124 | loaded_decl_holder->find_field(name(), signature(), &field_desc); |
duke@435 | 125 | if (canonical_holder == NULL) { |
duke@435 | 126 | // Field lookup failed. Will be detected by will_link. |
duke@435 | 127 | _holder = declared_holder; |
duke@435 | 128 | _offset = -1; |
duke@435 | 129 | _is_constant = false; |
duke@435 | 130 | return; |
duke@435 | 131 | } |
duke@435 | 132 | |
duke@435 | 133 | assert(canonical_holder == field_desc.field_holder(), "just checking"); |
duke@435 | 134 | initialize_from(&field_desc); |
duke@435 | 135 | } |
duke@435 | 136 | |
duke@435 | 137 | ciField::ciField(fieldDescriptor *fd): _known_to_link_with(NULL) { |
duke@435 | 138 | ASSERT_IN_VM; |
duke@435 | 139 | |
duke@435 | 140 | _cp_index = -1; |
duke@435 | 141 | |
duke@435 | 142 | // Get the field's name, signature, and type. |
duke@435 | 143 | ciEnv* env = CURRENT_ENV; |
duke@435 | 144 | _name = env->get_object(fd->name())->as_symbol(); |
duke@435 | 145 | _signature = env->get_object(fd->signature())->as_symbol(); |
duke@435 | 146 | |
duke@435 | 147 | BasicType field_type = fd->field_type(); |
duke@435 | 148 | |
duke@435 | 149 | // If the field is a pointer type, get the klass of the |
duke@435 | 150 | // field. |
duke@435 | 151 | if (field_type == T_OBJECT || field_type == T_ARRAY) { |
duke@435 | 152 | _type = NULL; // must call compute_type on first access |
duke@435 | 153 | } else { |
duke@435 | 154 | _type = ciType::make(field_type); |
duke@435 | 155 | } |
duke@435 | 156 | |
duke@435 | 157 | initialize_from(fd); |
duke@435 | 158 | |
duke@435 | 159 | // Either (a) it is marked shared, or else (b) we are done bootstrapping. |
duke@435 | 160 | assert(is_shared() || ciObjectFactory::is_initialized(), |
duke@435 | 161 | "bootstrap classes must not create & cache unshared fields"); |
duke@435 | 162 | } |
duke@435 | 163 | |
duke@435 | 164 | void ciField::initialize_from(fieldDescriptor* fd) { |
duke@435 | 165 | // Get the flags, offset, and canonical holder of the field. |
duke@435 | 166 | _flags = ciFlags(fd->access_flags()); |
duke@435 | 167 | _offset = fd->offset(); |
duke@435 | 168 | _holder = CURRENT_ENV->get_object(fd->field_holder())->as_instance_klass(); |
duke@435 | 169 | |
duke@435 | 170 | // Check to see if the field is constant. |
twisti@1573 | 171 | if (_holder->is_initialized() && this->is_final()) { |
twisti@1573 | 172 | if (!this->is_static()) { |
twisti@1573 | 173 | // A field can be constant if it's a final static field or if it's |
twisti@1573 | 174 | // a final non-static field of a trusted class ({java,sun}.dyn). |
twisti@1573 | 175 | if (_holder->is_in_package("java/dyn") || _holder->is_in_package("sun/dyn")) { |
twisti@1573 | 176 | _is_constant = true; |
twisti@1573 | 177 | return; |
twisti@1573 | 178 | } |
twisti@1573 | 179 | _is_constant = false; |
twisti@1573 | 180 | return; |
twisti@1573 | 181 | } |
twisti@1573 | 182 | |
duke@435 | 183 | // This field just may be constant. The only cases where it will |
duke@435 | 184 | // not be constant are: |
duke@435 | 185 | // |
duke@435 | 186 | // 1. The field holds a non-perm-space oop. The field is, strictly |
duke@435 | 187 | // speaking, constant but we cannot embed non-perm-space oops into |
duke@435 | 188 | // generated code. For the time being we need to consider the |
duke@435 | 189 | // field to be not constant. |
duke@435 | 190 | // 2. The field is a *special* static&final field whose value |
duke@435 | 191 | // may change. The three examples are java.lang.System.in, |
duke@435 | 192 | // java.lang.System.out, and java.lang.System.err. |
duke@435 | 193 | |
duke@435 | 194 | klassOop k = _holder->get_klassOop(); |
never@1577 | 195 | assert( SystemDictionary::System_klass() != NULL, "Check once per vm"); |
never@1577 | 196 | if( k == SystemDictionary::System_klass() ) { |
duke@435 | 197 | // Check offsets for case 2: System.in, System.out, or System.err |
duke@435 | 198 | if( _offset == java_lang_System::in_offset_in_bytes() || |
duke@435 | 199 | _offset == java_lang_System::out_offset_in_bytes() || |
duke@435 | 200 | _offset == java_lang_System::err_offset_in_bytes() ) { |
duke@435 | 201 | _is_constant = false; |
duke@435 | 202 | return; |
duke@435 | 203 | } |
duke@435 | 204 | } |
duke@435 | 205 | |
duke@435 | 206 | _is_constant = true; |
duke@435 | 207 | switch(type()->basic_type()) { |
duke@435 | 208 | case T_BYTE: |
duke@435 | 209 | _constant_value = ciConstant(type()->basic_type(), k->byte_field(_offset)); |
duke@435 | 210 | break; |
duke@435 | 211 | case T_CHAR: |
duke@435 | 212 | _constant_value = ciConstant(type()->basic_type(), k->char_field(_offset)); |
duke@435 | 213 | break; |
duke@435 | 214 | case T_SHORT: |
duke@435 | 215 | _constant_value = ciConstant(type()->basic_type(), k->short_field(_offset)); |
duke@435 | 216 | break; |
duke@435 | 217 | case T_BOOLEAN: |
duke@435 | 218 | _constant_value = ciConstant(type()->basic_type(), k->bool_field(_offset)); |
duke@435 | 219 | break; |
duke@435 | 220 | case T_INT: |
duke@435 | 221 | _constant_value = ciConstant(type()->basic_type(), k->int_field(_offset)); |
duke@435 | 222 | break; |
duke@435 | 223 | case T_FLOAT: |
duke@435 | 224 | _constant_value = ciConstant(k->float_field(_offset)); |
duke@435 | 225 | break; |
duke@435 | 226 | case T_DOUBLE: |
duke@435 | 227 | _constant_value = ciConstant(k->double_field(_offset)); |
duke@435 | 228 | break; |
duke@435 | 229 | case T_LONG: |
duke@435 | 230 | _constant_value = ciConstant(k->long_field(_offset)); |
duke@435 | 231 | break; |
duke@435 | 232 | case T_OBJECT: |
duke@435 | 233 | case T_ARRAY: |
duke@435 | 234 | { |
duke@435 | 235 | oop o = k->obj_field(_offset); |
duke@435 | 236 | |
duke@435 | 237 | // A field will be "constant" if it is known always to be |
duke@435 | 238 | // a non-null reference to an instance of a particular class, |
duke@435 | 239 | // or to a particular array. This can happen even if the instance |
duke@435 | 240 | // or array is not perm. In such a case, an "unloaded" ciArray |
duke@435 | 241 | // or ciInstance is created. The compiler may be able to use |
duke@435 | 242 | // information about the object's class (which is exact) or length. |
duke@435 | 243 | |
duke@435 | 244 | if (o == NULL) { |
duke@435 | 245 | _constant_value = ciConstant(type()->basic_type(), ciNullObject::make()); |
duke@435 | 246 | } else { |
duke@435 | 247 | _constant_value = ciConstant(type()->basic_type(), CURRENT_ENV->get_object(o)); |
duke@435 | 248 | assert(_constant_value.as_object() == CURRENT_ENV->get_object(o), "check interning"); |
duke@435 | 249 | } |
duke@435 | 250 | } |
duke@435 | 251 | } |
duke@435 | 252 | } else { |
duke@435 | 253 | _is_constant = false; |
duke@435 | 254 | } |
duke@435 | 255 | } |
duke@435 | 256 | |
duke@435 | 257 | // ------------------------------------------------------------------ |
duke@435 | 258 | // ciField::compute_type |
duke@435 | 259 | // |
duke@435 | 260 | // Lazily compute the type, if it is an instance klass. |
duke@435 | 261 | ciType* ciField::compute_type() { |
duke@435 | 262 | GUARDED_VM_ENTRY(return compute_type_impl();) |
duke@435 | 263 | } |
duke@435 | 264 | |
duke@435 | 265 | ciType* ciField::compute_type_impl() { |
duke@435 | 266 | ciKlass* type = CURRENT_ENV->get_klass_by_name_impl(_holder, _signature, false); |
duke@435 | 267 | if (!type->is_primitive_type() && is_shared()) { |
duke@435 | 268 | // We must not cache a pointer to an unshared type, in a shared field. |
duke@435 | 269 | bool type_is_also_shared = false; |
duke@435 | 270 | if (type->is_type_array_klass()) { |
duke@435 | 271 | type_is_also_shared = true; // int[] etc. are explicitly bootstrapped |
duke@435 | 272 | } else if (type->is_instance_klass()) { |
duke@435 | 273 | type_is_also_shared = type->as_instance_klass()->is_shared(); |
duke@435 | 274 | } else { |
duke@435 | 275 | // Currently there is no 'shared' query for array types. |
duke@435 | 276 | type_is_also_shared = !ciObjectFactory::is_initialized(); |
duke@435 | 277 | } |
duke@435 | 278 | if (!type_is_also_shared) |
duke@435 | 279 | return type; // Bummer. |
duke@435 | 280 | } |
duke@435 | 281 | _type = type; |
duke@435 | 282 | return type; |
duke@435 | 283 | } |
duke@435 | 284 | |
duke@435 | 285 | |
duke@435 | 286 | // ------------------------------------------------------------------ |
duke@435 | 287 | // ciField::will_link |
duke@435 | 288 | // |
duke@435 | 289 | // Can a specific access to this field be made without causing |
duke@435 | 290 | // link errors? |
duke@435 | 291 | bool ciField::will_link(ciInstanceKlass* accessing_klass, |
duke@435 | 292 | Bytecodes::Code bc) { |
duke@435 | 293 | VM_ENTRY_MARK; |
duke@435 | 294 | if (_offset == -1) { |
duke@435 | 295 | // at creation we couldn't link to our holder so we need to |
duke@435 | 296 | // maintain that stance, otherwise there's no safe way to use this |
duke@435 | 297 | // ciField. |
duke@435 | 298 | return false; |
duke@435 | 299 | } |
duke@435 | 300 | |
duke@435 | 301 | if (_known_to_link_with == accessing_klass) { |
duke@435 | 302 | return true; |
duke@435 | 303 | } |
duke@435 | 304 | |
duke@435 | 305 | FieldAccessInfo result; |
duke@435 | 306 | constantPoolHandle c_pool(THREAD, |
duke@435 | 307 | accessing_klass->get_instanceKlass()->constants()); |
duke@435 | 308 | LinkResolver::resolve_field(result, c_pool, _cp_index, |
duke@435 | 309 | Bytecodes::java_code(bc), |
duke@435 | 310 | true, false, KILL_COMPILE_ON_FATAL_(false)); |
duke@435 | 311 | |
duke@435 | 312 | // update the hit-cache, unless there is a problem with memory scoping: |
duke@435 | 313 | if (accessing_klass->is_shared() || !is_shared()) |
duke@435 | 314 | _known_to_link_with = accessing_klass; |
duke@435 | 315 | |
duke@435 | 316 | return true; |
duke@435 | 317 | } |
duke@435 | 318 | |
duke@435 | 319 | // ------------------------------------------------------------------ |
duke@435 | 320 | // ciField::print |
duke@435 | 321 | void ciField::print() { |
duke@435 | 322 | tty->print("<ciField "); |
duke@435 | 323 | _holder->print_name(); |
duke@435 | 324 | tty->print("."); |
duke@435 | 325 | _name->print_symbol(); |
duke@435 | 326 | tty->print(" offset=%d type=", _offset); |
duke@435 | 327 | if (_type != NULL) _type->print_name(); |
duke@435 | 328 | else tty->print("(reference)"); |
duke@435 | 329 | tty->print(" is_constant=%s", bool_to_str(_is_constant)); |
duke@435 | 330 | if (_is_constant) { |
duke@435 | 331 | tty->print(" constant_value="); |
duke@435 | 332 | _constant_value.print(); |
duke@435 | 333 | } |
duke@435 | 334 | tty->print(">"); |
duke@435 | 335 | } |
duke@435 | 336 | |
duke@435 | 337 | // ------------------------------------------------------------------ |
duke@435 | 338 | // ciField::print_name_on |
duke@435 | 339 | // |
duke@435 | 340 | // Print the name of this field |
duke@435 | 341 | void ciField::print_name_on(outputStream* st) { |
duke@435 | 342 | name()->print_symbol_on(st); |
duke@435 | 343 | } |