1 /*
   2  * Copyright (c) 2003, 2012, 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 
 244   bool match_flags = (_flags | target->flags()) == target->flags();
 245   if (match_flags || is_exception_handler && has_flag_match_exception(target)) {
 246     return true;
 247   } else {
 248     *ctx = ErrorContext::bad_flags(target->offset(),
 249         (StackMapFrame*)this, (StackMapFrame*)target);
 250     return false;
 251   }
 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_on(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 }