1/*
2 * Copyright (c) 2003, 2016, 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
34StackMapFrame::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
50StackMapFrame* 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
57void StackMapFrame::initialize_object(
58    VerificationType old_object, VerificationType new_object) {
59  int32_t i;
60  for (i = 0; i < _max_locals; i++) {
61    if (_locals[i].equals(old_object)) {
62      _locals[i] = new_object;
63    }
64  }
65  for (i = 0; i < _stack_size; i++) {
66    if (_stack[i].equals(old_object)) {
67      _stack[i] = new_object;
68    }
69  }
70  if (old_object == VerificationType::uninitialized_this_type()) {
71    // "this" has been initialized - reset flags
72    _flags = 0;
73  }
74}
75
76VerificationType StackMapFrame::set_locals_from_arg(
77    const methodHandle& m, VerificationType thisKlass, TRAPS) {
78  SignatureStream ss(m->signature());
79  int init_local_num = 0;
80  if (!m->is_static()) {
81    init_local_num++;
82    // add one extra argument for instance method
83    if (m->name() == vmSymbols::object_initializer_name() &&
84       thisKlass.name() != vmSymbols::java_lang_Object()) {
85      _locals[0] = VerificationType::uninitialized_this_type();
86      _flags |= FLAG_THIS_UNINIT;
87    } else {
88      _locals[0] = thisKlass;
89    }
90  }
91
92  // local num may be greater than size of parameters because long/double occupies two slots
93  while(!ss.at_return_type()) {
94    init_local_num += _verifier->change_sig_to_verificationType(
95      &ss, &_locals[init_local_num],
96      CHECK_VERIFY_(verifier(), VerificationType::bogus_type()));
97    ss.next();
98  }
99  _locals_size = init_local_num;
100
101  switch (ss.type()) {
102    case T_OBJECT:
103    case T_ARRAY:
104    {
105      Symbol* sig = ss.as_symbol(CHECK_(VerificationType::bogus_type()));
106      // Create another symbol to save as signature stream unreferences
107      // this symbol.
108      Symbol* sig_copy =
109        verifier()->create_temporary_symbol(sig, 0, sig->utf8_length(),
110                                 CHECK_(VerificationType::bogus_type()));
111      assert(sig_copy == sig, "symbols don't match");
112      return VerificationType::reference_type(sig_copy);
113    }
114    case T_INT:     return VerificationType::integer_type();
115    case T_BYTE:    return VerificationType::byte_type();
116    case T_CHAR:    return VerificationType::char_type();
117    case T_SHORT:   return VerificationType::short_type();
118    case T_BOOLEAN: return VerificationType::boolean_type();
119    case T_FLOAT:   return VerificationType::float_type();
120    case T_DOUBLE:  return VerificationType::double_type();
121    case T_LONG:    return VerificationType::long_type();
122    case T_VOID:    return VerificationType::bogus_type();
123    default:
124      ShouldNotReachHere();
125  }
126  return VerificationType::bogus_type();
127}
128
129void StackMapFrame::copy_locals(const StackMapFrame* src) {
130  int32_t len = src->locals_size() < _locals_size ?
131    src->locals_size() : _locals_size;
132  for (int32_t i = 0; i < len; i++) {
133    _locals[i] = src->locals()[i];
134  }
135}
136
137void StackMapFrame::copy_stack(const StackMapFrame* src) {
138  int32_t len = src->stack_size() < _stack_size ?
139    src->stack_size() : _stack_size;
140  for (int32_t i = 0; i < len; i++) {
141    _stack[i] = src->stack()[i];
142  }
143}
144
145// Returns the location of the first mismatch, or 'len' if there are no
146// mismatches
147int StackMapFrame::is_assignable_to(
148    VerificationType* from, VerificationType* to, int32_t len, TRAPS) const {
149  int32_t i = 0;
150  for (i = 0; i < len; i++) {
151    if (!to[i].is_assignable_from(from[i], verifier(), false, THREAD)) {
152      break;
153    }
154  }
155  return i;
156}
157
158bool StackMapFrame::is_assignable_to(
159    const StackMapFrame* target, ErrorContext* ctx, TRAPS) const {
160  if (_max_locals != target->max_locals()) {
161    *ctx = ErrorContext::locals_size_mismatch(
162        _offset, (StackMapFrame*)this, (StackMapFrame*)target);
163    return false;
164  }
165  if (_stack_size != target->stack_size()) {
166    *ctx = ErrorContext::stack_size_mismatch(
167        _offset, (StackMapFrame*)this, (StackMapFrame*)target);
168    return false;
169  }
170  // Only need to compare type elements up to target->locals() or target->stack().
171  // The remaining type elements in this state can be ignored because they are
172  // assignable to bogus type.
173  int mismatch_loc;
174  mismatch_loc = is_assignable_to(
175    _locals, target->locals(), target->locals_size(), THREAD);
176  if (mismatch_loc != target->locals_size()) {
177    *ctx = ErrorContext::bad_type(target->offset(),
178        TypeOrigin::local(mismatch_loc, (StackMapFrame*)this),
179        TypeOrigin::sm_local(mismatch_loc, (StackMapFrame*)target));
180    return false;
181  }
182  mismatch_loc = is_assignable_to(_stack, target->stack(), _stack_size, THREAD);
183  if (mismatch_loc != _stack_size) {
184    *ctx = ErrorContext::bad_type(target->offset(),
185        TypeOrigin::stack(mismatch_loc, (StackMapFrame*)this),
186        TypeOrigin::sm_stack(mismatch_loc, (StackMapFrame*)target));
187    return false;
188  }
189
190  if ((_flags | target->flags()) == target->flags()) {
191    return true;
192  } else {
193    *ctx = ErrorContext::bad_flags(target->offset(),
194        (StackMapFrame*)this, (StackMapFrame*)target);
195    return false;
196  }
197}
198
199VerificationType StackMapFrame::pop_stack_ex(VerificationType type, TRAPS) {
200  if (_stack_size <= 0) {
201    verifier()->verify_error(
202        ErrorContext::stack_underflow(_offset, this),
203        "Operand stack underflow");
204    return VerificationType::bogus_type();
205  }
206  VerificationType top = _stack[--_stack_size];
207  bool subtype = type.is_assignable_from(
208    top, verifier(), false, CHECK_(VerificationType::bogus_type()));
209  if (!subtype) {
210    verifier()->verify_error(
211        ErrorContext::bad_type(_offset, stack_top_ctx(),
212            TypeOrigin::implicit(type)),
213        "Bad type on operand stack");
214    return VerificationType::bogus_type();
215  }
216  return top;
217}
218
219VerificationType StackMapFrame::get_local(
220    int32_t index, VerificationType type, TRAPS) {
221  if (index >= _max_locals) {
222    verifier()->verify_error(
223        ErrorContext::bad_local_index(_offset, index),
224        "Local variable table overflow");
225    return VerificationType::bogus_type();
226  }
227  bool subtype = type.is_assignable_from(_locals[index],
228    verifier(), false, CHECK_(VerificationType::bogus_type()));
229  if (!subtype) {
230    verifier()->verify_error(
231        ErrorContext::bad_type(_offset,
232          TypeOrigin::local(index, this),
233          TypeOrigin::implicit(type)),
234        "Bad local variable type");
235    return VerificationType::bogus_type();
236  }
237  if(index >= _locals_size) { _locals_size = index + 1; }
238  return _locals[index];
239}
240
241void StackMapFrame::get_local_2(
242    int32_t index, VerificationType type1, VerificationType type2, TRAPS) {
243  assert(type1.is_long() || type1.is_double(), "must be long/double");
244  assert(type2.is_long2() || type2.is_double2(), "must be long/double_2");
245  if (index >= _locals_size - 1) {
246    verifier()->verify_error(
247        ErrorContext::bad_local_index(_offset, index),
248        "get long/double overflows locals");
249    return;
250  }
251  bool subtype = type1.is_assignable_from(_locals[index], verifier(), false, CHECK);
252  if (!subtype) {
253    verifier()->verify_error(
254        ErrorContext::bad_type(_offset,
255            TypeOrigin::local(index, this), TypeOrigin::implicit(type1)),
256        "Bad local variable type");
257  } else {
258    subtype = type2.is_assignable_from(_locals[index + 1], verifier(), false, CHECK);
259    if (!subtype) {
260      /* Unreachable? All local store routines convert a split long or double
261       * into a TOP during the store.  So we should never end up seeing an
262       * orphaned half.  */
263      verifier()->verify_error(
264          ErrorContext::bad_type(_offset,
265              TypeOrigin::local(index + 1, this), TypeOrigin::implicit(type2)),
266          "Bad local variable type");
267    }
268  }
269}
270
271void StackMapFrame::set_local(int32_t index, VerificationType type, TRAPS) {
272  assert(!type.is_check(), "Must be a real type");
273  if (index >= _max_locals) {
274    verifier()->verify_error(
275        ErrorContext::bad_local_index(_offset, index),
276        "Local variable table overflow");
277    return;
278  }
279  // If type at index is double or long, set the next location to be unusable
280  if (_locals[index].is_double() || _locals[index].is_long()) {
281    assert((index + 1) < _locals_size, "Local variable table overflow");
282    _locals[index + 1] = VerificationType::bogus_type();
283  }
284  // If type at index is double_2 or long_2, set the previous location to be unusable
285  if (_locals[index].is_double2() || _locals[index].is_long2()) {
286    assert(index >= 1, "Local variable table underflow");
287    _locals[index - 1] = VerificationType::bogus_type();
288  }
289  _locals[index] = type;
290  if (index >= _locals_size) {
291#ifdef ASSERT
292    for (int i=_locals_size; i<index; i++) {
293      assert(_locals[i] == VerificationType::bogus_type(),
294             "holes must be bogus type");
295    }
296#endif
297    _locals_size = index + 1;
298  }
299}
300
301void StackMapFrame::set_local_2(
302    int32_t index, VerificationType type1, VerificationType type2, TRAPS) {
303  assert(type1.is_long() || type1.is_double(), "must be long/double");
304  assert(type2.is_long2() || type2.is_double2(), "must be long/double_2");
305  if (index >= _max_locals - 1) {
306    verifier()->verify_error(
307        ErrorContext::bad_local_index(_offset, index),
308        "Local variable table overflow");
309    return;
310  }
311  // If type at index+1 is double or long, set the next location to be unusable
312  if (_locals[index+1].is_double() || _locals[index+1].is_long()) {
313    assert((index + 2) < _locals_size, "Local variable table overflow");
314    _locals[index + 2] = VerificationType::bogus_type();
315  }
316  // If type at index is double_2 or long_2, set the previous location to be unusable
317  if (_locals[index].is_double2() || _locals[index].is_long2()) {
318    assert(index >= 1, "Local variable table underflow");
319    _locals[index - 1] = VerificationType::bogus_type();
320  }
321  _locals[index] = type1;
322  _locals[index+1] = type2;
323  if (index >= _locals_size - 1) {
324#ifdef ASSERT
325    for (int i=_locals_size; i<index; i++) {
326      assert(_locals[i] == VerificationType::bogus_type(),
327             "holes must be bogus type");
328    }
329#endif
330    _locals_size = index + 2;
331  }
332}
333
334TypeOrigin StackMapFrame::stack_top_ctx() {
335  return TypeOrigin::stack(_stack_size, this);
336}
337
338void StackMapFrame::print_on(outputStream* str) const {
339  str->indent().print_cr("bci: @%d", _offset);
340  str->indent().print_cr("flags: {%s }",
341      flag_this_uninit() ? " flagThisUninit" : "");
342  str->indent().print("locals: {");
343  for (int32_t i = 0; i < _locals_size; ++i) {
344    str->print(" ");
345    _locals[i].print_on(str);
346    if (i != _locals_size - 1) {
347      str->print(",");
348    }
349  }
350  str->print_cr(" }");
351  str->indent().print("stack: {");
352  for (int32_t j = 0; j < _stack_size; ++j) {
353    str->print(" ");
354    _stack[j].print_on(str);
355    if (j != _stack_size - 1) {
356      str->print(",");
357    }
358  }
359  str->print_cr(" }");
360}
361