1 /* 2 * Copyright (c) 2003, 2011, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #include "precompiled.hpp" 26 #include "classfile/stackMapFrame.hpp" 27 #include "classfile/verifier.hpp" 28 #include "memory/resourceArea.hpp" 29 #include "oops/oop.inline.hpp" 30 #include "oops/symbol.hpp" 31 #include "runtime/handles.inline.hpp" 32 #include "utilities/globalDefinitions.hpp" 33 34 StackMapFrame::StackMapFrame(u2 max_locals, u2 max_stack, ClassVerifier* v) : 35 _offset(0), _locals_size(0), _stack_size(0), 36 _stack_mark(0), _flags(0), _max_locals(max_locals), 37 _max_stack(max_stack), _verifier(v) { 38 Thread* thr = v->thread(); 39 _locals = NEW_RESOURCE_ARRAY_IN_THREAD(thr, VerificationType, max_locals); 40 _stack = NEW_RESOURCE_ARRAY_IN_THREAD(thr, VerificationType, max_stack); 41 int32_t i; 42 for(i = 0; i < max_locals; i++) { 43 _locals[i] = VerificationType::bogus_type(); 44 } 45 for(i = 0; i < max_stack; i++) { 46 _stack[i] = VerificationType::bogus_type(); 47 } 48 } 49 50 StackMapFrame* StackMapFrame::frame_in_exception_handler(u1 flags) { 51 Thread* thr = _verifier->thread(); 52 VerificationType* stack = NEW_RESOURCE_ARRAY_IN_THREAD(thr, VerificationType, 1); 53 StackMapFrame* frame = new StackMapFrame(_offset, flags, _locals_size, 0, _max_locals, _max_stack, _locals, stack, _verifier); 54 return frame; 55 } 56 57 bool StackMapFrame::has_new_object() const { 58 int32_t i; 59 for (i = 0; i < _max_locals; i++) { 60 if (_locals[i].is_uninitialized()) { 61 return true; 62 } 63 } 64 for (i = 0; i < _stack_size; i++) { 65 if (_stack[i].is_uninitialized()) { 66 return true; 67 } 68 } 69 return false; 70 } 71 72 void StackMapFrame::initialize_object( 73 VerificationType old_object, VerificationType new_object) { 74 int32_t i; 75 for (i = 0; i < _max_locals; i++) { 76 if (_locals[i].equals(old_object)) { 77 _locals[i] = new_object; 78 } 79 } 80 for (i = 0; i < _stack_size; i++) { 81 if (_stack[i].equals(old_object)) { 82 _stack[i] = new_object; 83 } 84 } 85 if (old_object == VerificationType::uninitialized_this_type()) { 86 // "this" has been initialized - reset flags 87 _flags = 0; 88 } 89 } 90 91 VerificationType StackMapFrame::set_locals_from_arg( 92 const methodHandle m, VerificationType thisKlass, TRAPS) { 93 SignatureStream ss(m->signature()); 94 int init_local_num = 0; 95 if (!m->is_static()) { 96 init_local_num++; 97 // add one extra argument for instance method 98 if (m->name() == vmSymbols::object_initializer_name() && 99 thisKlass.name() != vmSymbols::java_lang_Object()) { 100 _locals[0] = VerificationType::uninitialized_this_type(); 101 _flags |= FLAG_THIS_UNINIT; 102 } else { 103 _locals[0] = thisKlass; 104 } 105 } 106 107 // local num may be greater than size of parameters because long/double occupies two slots 108 while(!ss.at_return_type()) { 109 init_local_num += _verifier->change_sig_to_verificationType( 110 &ss, &_locals[init_local_num], 111 CHECK_VERIFY_(verifier(), VerificationType::bogus_type())); 112 ss.next(); 113 } 114 _locals_size = init_local_num; 115 116 switch (ss.type()) { 117 case T_OBJECT: 118 case T_ARRAY: 119 { 120 Symbol* sig = ss.as_symbol(CHECK_(VerificationType::bogus_type())); 121 // Create another symbol to save as signature stream unreferences 122 // this symbol. 123 Symbol* sig_copy = 124 verifier()->create_temporary_symbol(sig, 0, sig->utf8_length(), 125 CHECK_(VerificationType::bogus_type())); 126 assert(sig_copy == sig, "symbols don't match"); 127 return VerificationType::reference_type(sig_copy); 128 } 129 case T_INT: return VerificationType::integer_type(); 130 case T_BYTE: return VerificationType::byte_type(); 131 case T_CHAR: return VerificationType::char_type(); 132 case T_SHORT: return VerificationType::short_type(); 133 case T_BOOLEAN: return VerificationType::boolean_type(); 134 case T_FLOAT: return VerificationType::float_type(); 135 case T_DOUBLE: return VerificationType::double_type(); 136 case T_LONG: return VerificationType::long_type(); 137 case T_VOID: return VerificationType::bogus_type(); 138 default: 139 ShouldNotReachHere(); 140 } 141 return VerificationType::bogus_type(); 142 } 143 144 void StackMapFrame::copy_locals(const StackMapFrame* src) { 145 int32_t len = src->locals_size() < _locals_size ? 146 src->locals_size() : _locals_size; 147 for (int32_t i = 0; i < len; i++) { 148 _locals[i] = src->locals()[i]; 149 } 150 } 151 152 void StackMapFrame::copy_stack(const StackMapFrame* src) { 153 int32_t len = src->stack_size() < _stack_size ? 154 src->stack_size() : _stack_size; 155 for (int32_t i = 0; i < len; i++) { 156 _stack[i] = src->stack()[i]; 157 } 158 } 159 160 // Returns the location of the first mismatch, or 'len' if there are no 161 // mismatches 162 int StackMapFrame::is_assignable_to( 163 VerificationType* from, VerificationType* to, int32_t len, TRAPS) const { 164 int32_t i = 0; 165 for (i = 0; i < len; i++) { 166 if (!to[i].is_assignable_from(from[i], verifier(), THREAD)) { 167 break; 168 } 169 } 170 return i; 171 } 172 173 bool StackMapFrame::has_flag_match_exception( 174 const StackMapFrame* target) const { 175 // We allow flags of {UninitThis} to assign to {} if-and-only-if the 176 // target frame does not depend upon the current type. 177 // This is slightly too strict, as we need only enforce that the 178 // slots that were initialized by the <init> (the things that were 179 // UninitializedThis before initialize_object() converted them) are unused. 180 // However we didn't save that information so we'll enforce this upon 181 // anything that might have been initialized. This is a rare situation 182 // and javac never generates code that would end up here, but some profilers 183 // (such as NetBeans) might, when adding exception handlers in <init> 184 // methods to cover the invokespecial instruction. See 7020118. 185 186 assert(max_locals() == target->max_locals() && 187 stack_size() == target->stack_size(), "StackMap sizes must match"); 188 189 VerificationType top = VerificationType::top_type(); 190 VerificationType this_type = verifier()->current_type(); 191 192 if (!flag_this_uninit() || target->flags() != 0) { 193 return false; 194 } 195 196 for (int i = 0; i < target->locals_size(); ++i) { 197 if (locals()[i] == this_type && target->locals()[i] != top) { 198 return false; 199 } 200 } 201 202 for (int i = 0; i < target->stack_size(); ++i) { 203 if (stack()[i] == this_type && target->stack()[i] != top) { 204 return false; 205 } 206 } 207 208 return true; 209 } 210 211 bool StackMapFrame::is_assignable_to( 212 const StackMapFrame* target, bool is_exception_handler, 213 ErrorContext* ctx, TRAPS) const { 214 if (_max_locals != target->max_locals()) { 215 *ctx = ErrorContext::locals_size_mismatch( 216 _offset, (StackMapFrame*)this, (StackMapFrame*)target); 217 return false; 218 } 219 if (_stack_size != target->stack_size()) { 220 *ctx = ErrorContext::stack_size_mismatch( 221 _offset, (StackMapFrame*)this, (StackMapFrame*)target); 222 return false; 223 } 224 // Only need to compare type elements up to target->locals() or target->stack(). 225 // The remaining type elements in this state can be ignored because they are 226 // assignable to bogus type. 227 int mismatch_loc; 228 mismatch_loc = is_assignable_to( 229 _locals, target->locals(), target->locals_size(), THREAD); 230 if (mismatch_loc != target->locals_size()) { 231 *ctx = ErrorContext::bad_type(target->offset(), 232 TypeOrigin::local(mismatch_loc, (StackMapFrame*)this), 233 TypeOrigin::sm_local(mismatch_loc, (StackMapFrame*)target)); 234 return false; 235 } 236 mismatch_loc = is_assignable_to(_stack, target->stack(), _stack_size, THREAD); 237 if (mismatch_loc != _stack_size) { 238 *ctx = ErrorContext::bad_type(target->offset(), 239 TypeOrigin::stack(mismatch_loc, (StackMapFrame*)this), 240 TypeOrigin::sm_stack(mismatch_loc, (StackMapFrame*)target)); 241 return false; 242 } 243 bool match_flags = (_flags | target->flags()) == target->flags(); 244 if (!match_flags && 245 (!is_exception_handler || !has_flag_match_exception(target))) { 246 *ctx = ErrorContext::bad_flags(target->offset(), 247 (StackMapFrame*)this, (StackMapFrame*)target); 248 return false; 249 } 250 251 return true; 252 } 253 254 VerificationType StackMapFrame::pop_stack_ex(VerificationType type, TRAPS) { 255 if (_stack_size <= 0) { 256 verifier()->verify_error( 257 ErrorContext::stack_underflow(_offset, this), 258 "Operand stack underflow"); 259 return VerificationType::bogus_type(); 260 } 261 VerificationType top = _stack[--_stack_size]; 262 bool subtype = type.is_assignable_from( 263 top, verifier(), CHECK_(VerificationType::bogus_type())); 264 if (!subtype) { 265 verifier()->verify_error( 266 ErrorContext::bad_type(_offset, stack_top_ctx(), 267 TypeOrigin::implicit(type)), 268 "Bad type on operand stack"); 269 return VerificationType::bogus_type(); 270 } 271 return top; 272 } 273 274 VerificationType StackMapFrame::get_local( 275 int32_t index, VerificationType type, TRAPS) { 276 if (index >= _max_locals) { 277 verifier()->verify_error( 278 ErrorContext::bad_local_index(_offset, index), 279 "Local variable table overflow"); 280 return VerificationType::bogus_type(); 281 } 282 bool subtype = type.is_assignable_from(_locals[index], 283 verifier(), CHECK_(VerificationType::bogus_type())); 284 if (!subtype) { 285 verifier()->verify_error( 286 ErrorContext::bad_type(_offset, 287 TypeOrigin::local(index, this), 288 TypeOrigin::implicit(type)), 289 "Bad local variable type"); 290 return VerificationType::bogus_type(); 291 } 292 if(index >= _locals_size) { _locals_size = index + 1; } 293 return _locals[index]; 294 } 295 296 void StackMapFrame::get_local_2( 297 int32_t index, VerificationType type1, VerificationType type2, TRAPS) { 298 assert(type1.is_long() || type1.is_double(), "must be long/double"); 299 assert(type2.is_long2() || type2.is_double2(), "must be long/double_2"); 300 if (index >= _locals_size - 1) { 301 verifier()->verify_error( 302 ErrorContext::bad_local_index(_offset, index), 303 "get long/double overflows locals"); 304 return; 305 } 306 bool subtype = type1.is_assignable_from(_locals[index], verifier(), CHECK); 307 if (!subtype) { 308 verifier()->verify_error( 309 ErrorContext::bad_type(_offset, 310 TypeOrigin::local(index, this), TypeOrigin::implicit(type1)), 311 "Bad local variable type"); 312 } else { 313 subtype = type2.is_assignable_from(_locals[index + 1], verifier(), CHECK); 314 if (!subtype) { 315 /* Unreachable? All local store routines convert a split long or double 316 * into a TOP during the store. So we should never end up seeing an 317 * orphaned half. */ 318 verifier()->verify_error( 319 ErrorContext::bad_type(_offset, 320 TypeOrigin::local(index + 1, this), TypeOrigin::implicit(type2)), 321 "Bad local variable type"); 322 } 323 } 324 } 325 326 void StackMapFrame::set_local(int32_t index, VerificationType type, TRAPS) { 327 assert(!type.is_check(), "Must be a real type"); 328 if (index >= _max_locals) { 329 verifier()->verify_error( 330 ErrorContext::bad_local_index(_offset, index), 331 "Local variable table overflow"); 332 return; 333 } 334 // If type at index is double or long, set the next location to be unusable 335 if (_locals[index].is_double() || _locals[index].is_long()) { 336 assert((index + 1) < _locals_size, "Local variable table overflow"); 337 _locals[index + 1] = VerificationType::bogus_type(); 338 } 339 // If type at index is double_2 or long_2, set the previous location to be unusable 340 if (_locals[index].is_double2() || _locals[index].is_long2()) { 341 assert(index >= 1, "Local variable table underflow"); 342 _locals[index - 1] = VerificationType::bogus_type(); 343 } 344 _locals[index] = type; 345 if (index >= _locals_size) { 346 #ifdef ASSERT 347 for (int i=_locals_size; i<index; i++) { 348 assert(_locals[i] == VerificationType::bogus_type(), 349 "holes must be bogus type"); 350 } 351 #endif 352 _locals_size = index + 1; 353 } 354 } 355 356 void StackMapFrame::set_local_2( 357 int32_t index, VerificationType type1, VerificationType type2, TRAPS) { 358 assert(type1.is_long() || type1.is_double(), "must be long/double"); 359 assert(type2.is_long2() || type2.is_double2(), "must be long/double_2"); 360 if (index >= _max_locals - 1) { 361 verifier()->verify_error( 362 ErrorContext::bad_local_index(_offset, index), 363 "Local variable table overflow"); 364 return; 365 } 366 // If type at index+1 is double or long, set the next location to be unusable 367 if (_locals[index+1].is_double() || _locals[index+1].is_long()) { 368 assert((index + 2) < _locals_size, "Local variable table overflow"); 369 _locals[index + 2] = VerificationType::bogus_type(); 370 } 371 // If type at index is double_2 or long_2, set the previous location to be unusable 372 if (_locals[index].is_double2() || _locals[index].is_long2()) { 373 assert(index >= 1, "Local variable table underflow"); 374 _locals[index - 1] = VerificationType::bogus_type(); 375 } 376 _locals[index] = type1; 377 _locals[index+1] = type2; 378 if (index >= _locals_size - 1) { 379 #ifdef ASSERT 380 for (int i=_locals_size; i<index; i++) { 381 assert(_locals[i] == VerificationType::bogus_type(), 382 "holes must be bogus type"); 383 } 384 #endif 385 _locals_size = index + 2; 386 } 387 } 388 389 TypeOrigin StackMapFrame::stack_top_ctx() { 390 return TypeOrigin::stack(_stack_size, this); 391 } 392 393 void StackMapFrame::print(outputStream* str) const { 394 str->indent().print_cr("bci: @%d", _offset); 395 str->indent().print_cr("flags: {%s }", 396 flag_this_uninit() ? " flagThisUninit" : ""); 397 str->indent().print("locals: {"); 398 for (int32_t i = 0; i < _locals_size; i++) { 399 str->print(" "); 400 _locals[i].print_on(str); 401 if (i != _locals_size - 1) { 402 str->print(","); 403 } 404 } 405 str->print_cr(" }"); 406 str->indent().print("stack: {"); 407 for (int32_t j = 0; j < _stack_size; j++) { 408 str->print(" "); 409 _stack[j].print_on(str); 410 if (j != _stack_size - 1) { 411 str->print(","); 412 } 413 } 414 str->print_cr(" }"); 415 }