Tue, 21 Apr 2009 23:21:04 -0700
6655646: dynamic languages need dynamically linked call sites
Summary: invokedynamic instruction (JSR 292 RI)
Reviewed-by: twisti, never
1 /*
2 * Copyright 1999-2005 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
20 * CA 95054 USA or visit www.sun.com if you need additional information or
21 * have any questions.
22 *
23 */
25 // ciBytecodeStream
26 //
27 // The class is used to iterate over the bytecodes of a method.
28 // It hides the details of constant pool structure/access by
29 // providing accessors for constant pool items. It returns only pure
30 // Java bytecodes; VM-internal _fast bytecodes are translated back to
31 // their original form during iteration.
32 class ciBytecodeStream : StackObj {
33 private:
34 // Handling for the weird bytecodes
35 Bytecodes::Code wide(); // Handle wide bytecode
36 Bytecodes::Code table(Bytecodes::Code); // Handle complicated inline table
38 static Bytecodes::Code check_java(Bytecodes::Code c) {
39 assert(Bytecodes::is_java_code(c), "should not return _fast bytecodes");
40 return c;
41 }
43 ciMethod* _method; // the method
44 ciInstanceKlass* _holder;
45 address _bc_start; // Start of current bytecode for table
46 address _was_wide; // Address past last wide bytecode
47 jint* _table_base; // Aligned start of last table or switch
49 address _start; // Start of bytecodes
50 address _end; // Past end of bytecodes
51 address _pc; // Current PC
52 Bytecodes::Code _bc; // Current bytecode
54 void reset( address base, unsigned int size ) {
55 _bc_start =_was_wide = 0;
56 _start = _pc = base; _end = base + size; }
58 public:
59 // End-Of-Bytecodes
60 static Bytecodes::Code EOBC() {
61 return Bytecodes::_illegal;
62 }
64 ciBytecodeStream(ciMethod* m) {
65 reset_to_method(m);
66 }
68 ciBytecodeStream() {
69 reset_to_method(NULL);
70 }
72 ciMethod* method() const { return _method; }
74 void reset_to_method(ciMethod* m) {
75 _method = m;
76 if (m == NULL) {
77 _holder = NULL;
78 reset(NULL, 0);
79 } else {
80 _holder = m->holder();
81 reset(m->code(), m->code_size());
82 }
83 }
85 void reset_to_bci( int bci );
87 // Force the iterator to report a certain bci.
88 void force_bci(int bci);
90 void set_max_bci( int max ) {
91 _end = _start + max;
92 }
94 address cur_bcp() const { return _bc_start; } // Returns bcp to current instruction
95 int next_bci() const { return _pc -_start; }
96 int cur_bci() const { return _bc_start - _start; }
97 int instruction_size() const { return _pc - _bc_start; }
99 Bytecodes::Code cur_bc() const{ return check_java(_bc); }
100 Bytecodes::Code next_bc() { return Bytecodes::java_code((Bytecodes::Code)* _pc); }
102 // Return current ByteCode and increment PC to next bytecode, skipping all
103 // intermediate constants. Returns EOBC at end.
104 // Expected usage:
105 // while( (bc = iter.next()) != EOBC() ) { ... }
106 Bytecodes::Code next() {
107 _bc_start = _pc; // Capture start of bc
108 if( _pc >= _end ) return EOBC(); // End-Of-Bytecodes
110 // Fetch Java bytecode
111 // All rewritten bytecodes maintain the size of original bytecode.
112 _bc = Bytecodes::java_code((Bytecodes::Code)*_pc);
113 int csize = Bytecodes::length_for(_bc); // Expected size
115 if( _bc == Bytecodes::_wide ) {
116 _bc=wide(); // Handle wide bytecode
117 } else if( csize == 0 ) {
118 _bc=table(_bc); // Handle inline tables
119 } else {
120 _pc += csize; // Bump PC past bytecode
121 }
122 return check_java(_bc);
123 }
125 bool is_wide() const { return ( _pc == _was_wide ); }
127 // Get a byte index following this bytecode.
128 // If prefixed with a wide bytecode, get a wide index.
129 int get_index() const {
130 assert_index_size(is_wide() ? 2 : 1);
131 return (_pc == _was_wide) // was widened?
132 ? Bytes::get_Java_u2(_bc_start+2) // yes, return wide index
133 : _bc_start[1]; // no, return narrow index
134 }
136 // Get 2-byte index (getfield/putstatic/etc)
137 int get_index_big() const {
138 assert_index_size(2);
139 return Bytes::get_Java_u2(_bc_start+1);
140 }
142 // Get 2-byte index (or 4-byte, for invokedynamic)
143 int get_index_int() const {
144 return has_giant_index() ? get_index_giant() : get_index_big();
145 }
147 // Get 4-byte index, for invokedynamic.
148 int get_index_giant() const {
149 assert_index_size(4);
150 return Bytes::get_native_u4(_bc_start+1);
151 }
153 bool has_giant_index() const { return (cur_bc() == Bytecodes::_invokedynamic); }
155 // Get dimensions byte (multinewarray)
156 int get_dimensions() const { return *(unsigned char*)(_pc-1); }
158 // Sign-extended index byte/short, no widening
159 int get_byte() const { return (int8_t)(_pc[-1]); }
160 int get_short() const { return (int16_t)Bytes::get_Java_u2(_pc-2); }
161 int get_long() const { return (int32_t)Bytes::get_Java_u4(_pc-4); }
163 // Get a byte signed constant for "iinc". Invalid for other bytecodes.
164 // If prefixed with a wide bytecode, get a wide constant
165 int get_iinc_con() const {return (_pc==_was_wide) ? get_short() :get_byte();}
167 // 2-byte branch offset from current pc
168 int get_dest( ) const {
169 assert( Bytecodes::length_at(_bc_start) == sizeof(jshort)+1, "get_dest called with bad bytecode" );
170 return _bc_start-_start + (short)Bytes::get_Java_u2(_pc-2);
171 }
173 // 2-byte branch offset from next pc
174 int next_get_dest( ) const {
175 address next_bc_start = _pc;
176 assert( _pc < _end, "" );
177 Bytecodes::Code next_bc = (Bytecodes::Code)*_pc;
178 assert( next_bc != Bytecodes::_wide, "");
179 int next_csize = Bytecodes::length_for(next_bc);
180 assert( next_csize != 0, "" );
181 assert( next_bc <= Bytecodes::_jsr_w, "");
182 address next_pc = _pc + next_csize;
183 assert( Bytecodes::length_at(next_bc_start) == sizeof(jshort)+1, "next_get_dest called with bad bytecode" );
184 return next_bc_start-_start + (short)Bytes::get_Java_u2(next_pc-2);
185 }
187 // 4-byte branch offset from current pc
188 int get_far_dest( ) const {
189 assert( Bytecodes::length_at(_bc_start) == sizeof(jint)+1, "dest4 called with bad bytecode" );
190 return _bc_start-_start + (int)Bytes::get_Java_u4(_pc-4);
191 }
193 // For a lookup or switch table, return target destination
194 int get_int_table( int index ) const {
195 return Bytes::get_Java_u4((address)&_table_base[index]); }
197 // For tableswitch - get length of offset part
198 int get_tableswitch_length() { return get_int_table(2)-get_int_table(1)+1; }
200 int get_dest_table( int index ) const {
201 return cur_bci() + get_int_table(index); }
203 // --- Constant pool access ---
204 int get_constant_index() const;
205 int get_field_index();
206 int get_method_index();
208 // If this bytecode is a new, newarray, multianewarray, instanceof,
209 // or checkcast, get the referenced klass.
210 ciKlass* get_klass(bool& will_link);
211 int get_klass_index() const;
213 // If this bytecode is one of the ldc variants, get the referenced
214 // constant
215 ciConstant get_constant();
216 // True if the ldc variant points to an unresolved string
217 bool is_unresolved_string() const;
218 // True if the ldc variant points to an unresolved klass
219 bool is_unresolved_klass() const;
221 // If this bytecode is one of get_field, get_static, put_field,
222 // or put_static, get the referenced field.
223 ciField* get_field(bool& will_link);
225 ciInstanceKlass* get_declared_field_holder();
226 int get_field_holder_index();
227 int get_field_signature_index();
229 // If this is a method invocation bytecode, get the invoked method.
230 ciMethod* get_method(bool& will_link);
231 ciKlass* get_declared_method_holder();
232 int get_method_holder_index();
233 int get_method_signature_index();
235 private:
236 void assert_index_size(int required_size) const {
237 #ifdef ASSERT
238 int isize = instruction_size() - (is_wide() ? 1 : 0) - 1;
239 if (isize == 2 && cur_bc() == Bytecodes::_iinc)
240 isize = 1;
241 else if (isize <= 2)
242 ; // no change
243 else if (has_giant_index())
244 isize = 4;
245 else
246 isize = 2;
247 assert(isize = required_size, "wrong index size");
248 #endif
249 }
250 };
253 // ciSignatureStream
254 //
255 // The class is used to iterate over the elements of a method signature.
256 class ciSignatureStream : public StackObj {
257 private:
258 ciSignature* _sig;
259 int _pos;
260 public:
261 ciSignatureStream(ciSignature* signature) {
262 _sig = signature;
263 _pos = 0;
264 }
266 bool at_return_type() { return _pos == _sig->count(); }
268 bool is_done() { return _pos > _sig->count(); }
270 void next() {
271 if (_pos <= _sig->count()) {
272 _pos++;
273 }
274 }
276 ciType* type() {
277 if (at_return_type()) {
278 return _sig->return_type();
279 } else {
280 return _sig->type_at(_pos);
281 }
282 }
283 };
286 // ciExceptionHandlerStream
287 //
288 // The class is used to iterate over the exception handlers of
289 // a method.
290 class ciExceptionHandlerStream : public StackObj {
291 private:
292 // The method whose handlers we are traversing
293 ciMethod* _method;
295 // Our current position in the list of handlers
296 int _pos;
297 int _end;
299 ciInstanceKlass* _exception_klass;
300 int _bci;
301 bool _is_exact;
303 public:
304 ciExceptionHandlerStream(ciMethod* method) {
305 _method = method;
307 // Force loading of method code and handlers.
308 _method->code();
310 _pos = 0;
311 _end = _method->_handler_count;
312 _exception_klass = NULL;
313 _bci = -1;
314 _is_exact = false;
315 }
317 ciExceptionHandlerStream(ciMethod* method, int bci,
318 ciInstanceKlass* exception_klass = NULL,
319 bool is_exact = false) {
320 _method = method;
322 // Force loading of method code and handlers.
323 _method->code();
325 _pos = -1;
326 _end = _method->_handler_count + 1; // include the rethrow handler
327 _exception_klass = (exception_klass != NULL && exception_klass->is_loaded()
328 ? exception_klass
329 : NULL);
330 _bci = bci;
331 assert(_bci >= 0, "bci out of range");
332 _is_exact = is_exact;
333 next();
334 }
336 // These methods are currently implemented in an odd way.
337 // Count the number of handlers the iterator has ever produced
338 // or will ever produce. Do not include the final rethrow handler.
339 // That is, a trivial exception handler stream will have a count
340 // of zero and produce just the rethrow handler.
341 int count();
343 // Count the number of handlers this stream will produce from now on.
344 // Include the current handler, and the final rethrow handler.
345 // The remaining count will be zero iff is_done() is true,
346 int count_remaining();
348 bool is_done() {
349 return (_pos >= _end);
350 }
352 void next() {
353 _pos++;
354 if (_bci != -1) {
355 // We are not iterating over all handlers...
356 while (!is_done()) {
357 ciExceptionHandler* handler = _method->_exception_handlers[_pos];
358 if (handler->is_in_range(_bci)) {
359 if (handler->is_catch_all()) {
360 // Found final active catch block.
361 _end = _pos+1;
362 return;
363 } else if (_exception_klass == NULL || !handler->catch_klass()->is_loaded()) {
364 // We cannot do any type analysis here. Must conservatively assume
365 // catch block is reachable.
366 return;
367 } else if (_exception_klass->is_subtype_of(handler->catch_klass())) {
368 // This catch clause will definitely catch the exception.
369 // Final candidate.
370 _end = _pos+1;
371 return;
372 } else if (!_is_exact &&
373 handler->catch_klass()->is_subtype_of(_exception_klass)) {
374 // This catch block may be reachable.
375 return;
376 }
377 }
379 // The catch block was not pertinent. Go on.
380 _pos++;
381 }
382 } else {
383 // This is an iteration over all handlers.
384 return;
385 }
386 }
388 ciExceptionHandler* handler() {
389 return _method->_exception_handlers[_pos];
390 }
391 };