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/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), _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 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
161 bool StackMapFrame::is_assignable_to(
162 VerificationType* from, VerificationType* to, int32_t len, TRAPS) const {
163 for (int32_t i = 0; i < len; i++) {
164 bool subtype = to[i].is_assignable_from(
165 from[i], verifier(), THREAD);
166 if (!subtype) {
167 return false;
168 }
169 }
170 return true;
171 }
172
173 bool StackMapFrame::is_assignable_to(const StackMapFrame* target, TRAPS) const {
174 if (_max_locals != target->max_locals() || _stack_size != target->stack_size()) {
175 return false;
176 }
177 // Only need to compare type elements up to target->locals() or target->stack().
178 // The remaining type elements in this state can be ignored because they are
179 // assignable to bogus type.
180 bool match_locals = is_assignable_to(
181 _locals, target->locals(), target->locals_size(), CHECK_false);
182 bool match_stack = is_assignable_to(
183 _stack, target->stack(), _stack_size, CHECK_false);
184 bool match_flags = (_flags | target->flags()) == target->flags();
185 return (match_locals && match_stack && match_flags);
186 }
187
188 VerificationType StackMapFrame::pop_stack_ex(VerificationType type, TRAPS) {
189 if (_stack_size <= 0) {
190 verifier()->verify_error(_offset, "Operand stack underflow");
191 return VerificationType::bogus_type();
192 }
193 VerificationType top = _stack[--_stack_size];
194 bool subtype = type.is_assignable_from(
195 top, verifier(), CHECK_(VerificationType::bogus_type()));
196 if (!subtype) {
197 verifier()->verify_error(_offset, "Bad type on operand stack");
198 return VerificationType::bogus_type();
199 }
200 NOT_PRODUCT( _stack[_stack_size] = VerificationType::bogus_type(); )
201 return top;
202 }
203
204 VerificationType StackMapFrame::get_local(
205 int32_t index, VerificationType type, TRAPS) {
206 if (index >= _max_locals) {
207 verifier()->verify_error(_offset, "Local variable table overflow");
208 return VerificationType::bogus_type();
209 }
210 bool subtype = type.is_assignable_from(_locals[index],
211 verifier(), CHECK_(VerificationType::bogus_type()));
212 if (!subtype) {
213 verifier()->verify_error(_offset, "Bad local variable type");
214 return VerificationType::bogus_type();
215 }
216 if(index >= _locals_size) { _locals_size = index + 1; }
217 return _locals[index];
218 }
219
220 void StackMapFrame::get_local_2(
221 int32_t index, VerificationType type1, VerificationType type2, TRAPS) {
222 assert(type1.is_long() || type1.is_double(), "must be long/double");
223 assert(type2.is_long2() || type2.is_double2(), "must be long/double_2");
224 if (index >= _locals_size - 1) {
225 verifier()->verify_error(_offset, "get long/double overflows locals");
226 return;
227 }
228 bool subtype1 = type1.is_assignable_from(
229 _locals[index], verifier(), CHECK);
230 bool subtype2 = type2.is_assignable_from(
231 _locals[index+1], verifier(), CHECK);
232 if (!subtype1 || !subtype2) {
233 verifier()->verify_error(_offset, "Bad local variable type");
234 return;
235 }
236 }
237
238 void StackMapFrame::set_local(int32_t index, VerificationType type, TRAPS) {
239 assert(!type.is_check(), "Must be a real type");
240 if (index >= _max_locals) {
241 verifier()->verify_error("Local variable table overflow", _offset);
242 return;
243 }
244 // If type at index is double or long, set the next location to be unusable
245 if (_locals[index].is_double() || _locals[index].is_long()) {
246 assert((index + 1) < _locals_size, "Local variable table overflow");
247 _locals[index + 1] = VerificationType::bogus_type();
248 }
249 // If type at index is double_2 or long_2, set the previous location to be unusable
250 if (_locals[index].is_double2() || _locals[index].is_long2()) {
251 assert(index >= 1, "Local variable table underflow");
252 _locals[index - 1] = VerificationType::bogus_type();
253 }
254 _locals[index] = type;
255 if (index >= _locals_size) {
256 #ifdef ASSERT
257 for (int i=_locals_size; i<index; i++) {
258 assert(_locals[i] == VerificationType::bogus_type(),
259 "holes must be bogus type");
260 }
261 #endif
262 _locals_size = index + 1;
263 }
264 }
265
266 void StackMapFrame::set_local_2(
267 int32_t index, VerificationType type1, VerificationType type2, TRAPS) {
268 assert(type1.is_long() || type1.is_double(), "must be long/double");
269 assert(type2.is_long2() || type2.is_double2(), "must be long/double_2");
270 if (index >= _max_locals - 1) {
271 verifier()->verify_error("Local variable table overflow", _offset);
272 return;
273 }
274 // If type at index+1 is double or long, set the next location to be unusable
275 if (_locals[index+1].is_double() || _locals[index+1].is_long()) {
276 assert((index + 2) < _locals_size, "Local variable table overflow");
277 _locals[index + 2] = VerificationType::bogus_type();
278 }
279 // If type at index is double_2 or long_2, set the previous location to be unusable
280 if (_locals[index].is_double2() || _locals[index].is_long2()) {
281 assert(index >= 1, "Local variable table underflow");
282 _locals[index - 1] = VerificationType::bogus_type();
283 }
284 _locals[index] = type1;
285 _locals[index+1] = type2;
286 if (index >= _locals_size - 1) {
287 #ifdef ASSERT
288 for (int i=_locals_size; i<index; i++) {
289 assert(_locals[i] == VerificationType::bogus_type(),
290 "holes must be bogus type");
291 }
292 #endif
293 _locals_size = index + 2;
294 }
295 }
296
297 #ifndef PRODUCT
298
299 void StackMapFrame::print() const {
300 tty->print_cr("stackmap_frame[%d]:", _offset);
301 tty->print_cr("flags = 0x%x", _flags);
302 tty->print("locals[%d] = { ", _locals_size);
303 for (int32_t i = 0; i < _locals_size; i++) {
304 _locals[i].print_on(tty);
305 }
306 tty->print_cr(" }");
307 tty->print("stack[%d] = { ", _stack_size);
308 for (int32_t j = 0; j < _stack_size; j++) {
309 _stack[j].print_on(tty);
310 }
311 tty->print_cr(" }");
312 }
313
314 #endif