1 /*
2 * Copyright (c) 2003, 2010, 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/symbolOop.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), _flags(0),
36 _max_locals(max_locals), _max_stack(max_stack),
37 _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 symbolHandle signature(THREAD, m->signature());
94 SignatureStream ss(signature);
95 int init_local_num = 0;
96 if (!m->is_static()) {
97 init_local_num++;
98 // add one extra argument for instance method
99 if (m->name() == vmSymbols::object_initializer_name() &&
100 thisKlass.name() != vmSymbols::java_lang_Object()) {
101 _locals[0] = VerificationType::uninitialized_this_type();
102 _flags |= FLAG_THIS_UNINIT;
103 } else {
104 _locals[0] = thisKlass;
105 }
106 }
107
108 // local num may be greater than size of parameters because long/double occupies two slots
109 while(!ss.at_return_type()) {
110 init_local_num += _verifier->change_sig_to_verificationType(
111 &ss, &_locals[init_local_num],
112 CHECK_VERIFY_(verifier(), VerificationType::bogus_type()));
113 ss.next();
114 }
115 _locals_size = init_local_num;
116
117 switch (ss.type()) {
118 case T_OBJECT:
119 case T_ARRAY:
120 {
121 symbolOop sig = ss.as_symbol(CHECK_(VerificationType::bogus_type()));
122 return VerificationType::reference_type(symbolHandle(THREAD, sig));
123 }
124 case T_INT: return VerificationType::integer_type();
125 case T_BYTE: return VerificationType::byte_type();
126 case T_CHAR: return VerificationType::char_type();
127 case T_SHORT: return VerificationType::short_type();
128 case T_BOOLEAN: return VerificationType::boolean_type();
129 case T_FLOAT: return VerificationType::float_type();
130 case T_DOUBLE: return VerificationType::double_type();
131 case T_LONG: return VerificationType::long_type();
132 case T_VOID: return VerificationType::bogus_type();
133 default:
134 ShouldNotReachHere();
135 }
136 return VerificationType::bogus_type();
137 }
138
139 void StackMapFrame::copy_locals(const StackMapFrame* src) {
140 int32_t len = src->locals_size() < _locals_size ?
141 src->locals_size() : _locals_size;
142 for (int32_t i = 0; i < len; i++) {
143 _locals[i] = src->locals()[i];
144 }
145 }
146
147 void StackMapFrame::copy_stack(const StackMapFrame* src) {
148 int32_t len = src->stack_size() < _stack_size ?
149 src->stack_size() : _stack_size;
150 for (int32_t i = 0; i < len; i++) {
151 _stack[i] = src->stack()[i];
152 }
153 }
154
155
156 bool StackMapFrame::is_assignable_to(
157 VerificationType* from, VerificationType* to, int32_t len, TRAPS) const {
158 for (int32_t i = 0; i < len; i++) {
159 bool subtype = to[i].is_assignable_from(
160 from[i], verifier()->current_class(), THREAD);
161 if (!subtype) {
162 return false;
163 }
164 }
165 return true;
166 }
167
168 bool StackMapFrame::is_assignable_to(const StackMapFrame* target, TRAPS) const {
169 if (_max_locals != target->max_locals() || _stack_size != target->stack_size()) {
170 return false;
171 }
172 // Only need to compare type elements up to target->locals() or target->stack().
173 // The remaining type elements in this state can be ignored because they are
174 // assignable to bogus type.
175 bool match_locals = is_assignable_to(
176 _locals, target->locals(), target->locals_size(), CHECK_false);
177 bool match_stack = is_assignable_to(
178 _stack, target->stack(), _stack_size, CHECK_false);
179 bool match_flags = (_flags | target->flags()) == target->flags();
180 return (match_locals && match_stack && match_flags);
181 }
182
183 VerificationType StackMapFrame::pop_stack_ex(VerificationType type, TRAPS) {
184 if (_stack_size <= 0) {
185 verifier()->verify_error(_offset, "Operand stack underflow");
186 return VerificationType::bogus_type();
187 }
188 VerificationType top = _stack[--_stack_size];
189 bool subtype = type.is_assignable_from(
190 top, verifier()->current_class(), CHECK_(VerificationType::bogus_type()));
191 if (!subtype) {
192 verifier()->verify_error(_offset, "Bad type on operand stack");
193 return VerificationType::bogus_type();
194 }
195 NOT_PRODUCT( _stack[_stack_size] = VerificationType::bogus_type(); )
196 return top;
197 }
198
199 VerificationType StackMapFrame::get_local(
200 int32_t index, VerificationType type, TRAPS) {
201 if (index >= _max_locals) {
202 verifier()->verify_error(_offset, "Local variable table overflow");
203 return VerificationType::bogus_type();
204 }
205 bool subtype = type.is_assignable_from(_locals[index],
206 verifier()->current_class(), CHECK_(VerificationType::bogus_type()));
207 if (!subtype) {
208 verifier()->verify_error(_offset, "Bad local variable type");
209 return VerificationType::bogus_type();
210 }
211 if(index >= _locals_size) { _locals_size = index + 1; }
212 return _locals[index];
213 }
214
215 void StackMapFrame::get_local_2(
216 int32_t index, VerificationType type1, VerificationType type2, TRAPS) {
217 assert(type1.is_long() || type1.is_double(), "must be long/double");
218 assert(type2.is_long2() || type2.is_double2(), "must be long/double_2");
219 if (index >= _locals_size - 1) {
220 verifier()->verify_error(_offset, "get long/double overflows locals");
221 return;
222 }
223 bool subtype1 = type1.is_assignable_from(
224 _locals[index], verifier()->current_class(), CHECK);
225 bool subtype2 = type2.is_assignable_from(
226 _locals[index+1], verifier()->current_class(), CHECK);
227 if (!subtype1 || !subtype2) {
228 verifier()->verify_error(_offset, "Bad local variable type");
229 return;
230 }
231 }
232
233 void StackMapFrame::set_local(int32_t index, VerificationType type, TRAPS) {
234 assert(!type.is_check(), "Must be a real type");
235 if (index >= _max_locals) {
236 verifier()->verify_error("Local variable table overflow", _offset);
237 return;
238 }
239 // If type at index is double or long, set the next location to be unusable
240 if (_locals[index].is_double() || _locals[index].is_long()) {
241 assert((index + 1) < _locals_size, "Local variable table overflow");
242 _locals[index + 1] = VerificationType::bogus_type();
243 }
244 // If type at index is double_2 or long_2, set the previous location to be unusable
245 if (_locals[index].is_double2() || _locals[index].is_long2()) {
246 assert(index >= 1, "Local variable table underflow");
247 _locals[index - 1] = VerificationType::bogus_type();
248 }
249 _locals[index] = type;
250 if (index >= _locals_size) {
251 #ifdef ASSERT
252 for (int i=_locals_size; i<index; i++) {
253 assert(_locals[i] == VerificationType::bogus_type(),
254 "holes must be bogus type");
255 }
256 #endif
257 _locals_size = index + 1;
258 }
259 }
260
261 void StackMapFrame::set_local_2(
262 int32_t index, VerificationType type1, VerificationType type2, TRAPS) {
263 assert(type1.is_long() || type1.is_double(), "must be long/double");
264 assert(type2.is_long2() || type2.is_double2(), "must be long/double_2");
265 if (index >= _max_locals - 1) {
266 verifier()->verify_error("Local variable table overflow", _offset);
267 return;
268 }
269 // If type at index+1 is double or long, set the next location to be unusable
270 if (_locals[index+1].is_double() || _locals[index+1].is_long()) {
271 assert((index + 2) < _locals_size, "Local variable table overflow");
272 _locals[index + 2] = VerificationType::bogus_type();
273 }
274 // If type at index is double_2 or long_2, set the previous location to be unusable
275 if (_locals[index].is_double2() || _locals[index].is_long2()) {
276 assert(index >= 1, "Local variable table underflow");
277 _locals[index - 1] = VerificationType::bogus_type();
278 }
279 _locals[index] = type1;
280 _locals[index+1] = type2;
281 if (index >= _locals_size - 1) {
282 #ifdef ASSERT
283 for (int i=_locals_size; i<index; i++) {
284 assert(_locals[i] == VerificationType::bogus_type(),
285 "holes must be bogus type");
286 }
287 #endif
288 _locals_size = index + 2;
289 }
290 }
291
292 #ifndef PRODUCT
293
294 void StackMapFrame::print() const {
295 tty->print_cr("stackmap_frame[%d]:", _offset);
296 tty->print_cr("flags = 0x%x", _flags);
297 tty->print("locals[%d] = { ", _locals_size);
298 for (int32_t i = 0; i < _locals_size; i++) {
299 _locals[i].print_on(tty);
300 }
301 tty->print_cr(" }");
302 tty->print("stack[%d] = { ", _stack_size);
303 for (int32_t j = 0; j < _stack_size; j++) {
304 _stack[j].print_on(tty);
305 }
306 tty->print_cr(" }");
307 }
308
309 #endif