1 /*
2 * Copyright (c) 1997, 2015, 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.
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23 */
24
25 #ifndef SHARE_VM_RUNTIME_SIGNATURE_HPP
26 #define SHARE_VM_RUNTIME_SIGNATURE_HPP
27
28 #include "memory/allocation.hpp"
29 #include "oops/method.hpp"
30
31 // SignatureIterators iterate over a Java signature (or parts of it).
32 // (Syntax according to: "The Java Virtual Machine Specification" by
33 // Tim Lindholm & Frank Yellin; section 4.3 Descriptors; p. 89ff.)
34 //
35 // Example: Iterating over ([Lfoo;D)I using
36 // 0123456789
37 //
38 // iterate_parameters() calls: do_array(2, 7); do_double();
39 // iterate_returntype() calls: do_int();
40 // iterate() calls: do_array(2, 7); do_double(); do_int();
41 //
42 // is_return_type() is: false ; false ; true
43 //
44 // NOTE: The new optimizer has an alternate, for-loop based signature
45 // iterator implemented in opto/type.cpp, TypeTuple::make().
46
47 class SignatureIterator: public ResourceObj {
48 protected:
49 Symbol* _signature; // the signature to iterate over
50 int _index; // the current character index (only valid during iteration)
51 int _parameter_index; // the current parameter index (0 outside iteration phase)
52 BasicType _return_type;
53
54 void expect(char c);
55 void skip_optional_size();
56 int parse_type(); // returns the parameter size in words (0 for void)
57 void check_signature_end();
58
59 public:
60 // Definitions used in generating and iterating the
61 // bit field form of the signature generated by the
62 // Fingerprinter.
63 enum {
64 static_feature_size = 1,
65 is_static_bit = 1,
66
67 result_feature_size = 4,
68 result_feature_mask = 0xF,
69 parameter_feature_size = 4,
70 parameter_feature_mask = 0xF,
71
72 bool_parm = 1,
73 byte_parm = 2,
74 char_parm = 3,
75 short_parm = 4,
76 int_parm = 5,
77 long_parm = 6,
78 float_parm = 7,
79 double_parm = 8,
80 obj_parm = 9,
81 done_parm = 10, // marker for end of parameters
82
83 // max parameters is wordsize minus
84 // The sign bit, termination field, the result and static bit fields
85 max_size_of_parameters = (BitsPerLong-1 -
86 result_feature_size - parameter_feature_size -
87 static_feature_size) / parameter_feature_size
88 };
89
90 // Constructors
91 SignatureIterator(Symbol* signature);
92
93 // Iteration
94 void dispatch_field(); // dispatches once for field signatures
95 void iterate_parameters(); // iterates over parameters only
96 void iterate_parameters( uint64_t fingerprint );
97 void iterate_returntype(); // iterates over returntype only
98 void iterate(); // iterates over whole signature
99 // Returns the word index of the current parameter;
100 int parameter_index() const { return _parameter_index; }
101 bool is_return_type() const { return parameter_index() < 0; }
102 BasicType get_ret_type() const { return _return_type; }
103
104 // Basic types
105 virtual void do_bool () = 0;
106 virtual void do_char () = 0;
107 virtual void do_float () = 0;
108 virtual void do_double() = 0;
109 virtual void do_byte () = 0;
110 virtual void do_short () = 0;
111 virtual void do_int () = 0;
112 virtual void do_long () = 0;
113 virtual void do_void () = 0;
114
115 // Object types (begin indexes the first character of the entry, end indexes the first character after the entry)
116 virtual void do_object(int begin, int end) = 0;
117 virtual void do_array (int begin, int end) = 0;
118
119 static bool is_static(uint64_t fingerprint) {
120 assert(fingerprint != (uint64_t)CONST64(-1), "invalid fingerprint");
121 return fingerprint & is_static_bit;
122 }
123 static BasicType return_type(uint64_t fingerprint) {
124 assert(fingerprint != (uint64_t)CONST64(-1), "invalid fingerprint");
125 return (BasicType) ((fingerprint >> static_feature_size) & result_feature_mask);
126 }
127 };
128
129
130 // Specialized SignatureIterators: Used to compute signature specific values.
131
132 class SignatureTypeNames : public SignatureIterator {
133 protected:
134 virtual void type_name(const char* name) = 0;
135
136 void do_bool() { type_name("jboolean"); }
137 void do_char() { type_name("jchar" ); }
138 void do_float() { type_name("jfloat" ); }
139 void do_double() { type_name("jdouble" ); }
140 void do_byte() { type_name("jbyte" ); }
141 void do_short() { type_name("jshort" ); }
142 void do_int() { type_name("jint" ); }
143 void do_long() { type_name("jlong" ); }
144 void do_void() { type_name("void" ); }
145 void do_object(int begin, int end) { type_name("jobject" ); }
146 void do_array (int begin, int end) { type_name("jobject" ); }
147
148 public:
149 SignatureTypeNames(Symbol* signature) : SignatureIterator(signature) {}
150 };
151
152
153 class SignatureInfo: public SignatureIterator {
154 protected:
155 bool _has_iterated; // need this because iterate cannot be called in constructor (set is virtual!)
156 bool _has_iterated_return;
157 int _size;
158
159 void lazy_iterate_parameters() { if (!_has_iterated) { iterate_parameters(); _has_iterated = true; } }
160 void lazy_iterate_return() { if (!_has_iterated_return) { iterate_returntype(); _has_iterated_return = true; } }
161
162 virtual void set(int size, BasicType type) = 0;
163
164 void do_bool () { set(T_BOOLEAN_size, T_BOOLEAN); }
165 void do_char () { set(T_CHAR_size , T_CHAR ); }
166 void do_float () { set(T_FLOAT_size , T_FLOAT ); }
167 void do_double() { set(T_DOUBLE_size , T_DOUBLE ); }
168 void do_byte () { set(T_BYTE_size , T_BYTE ); }
169 void do_short () { set(T_SHORT_size , T_SHORT ); }
170 void do_int () { set(T_INT_size , T_INT ); }
171 void do_long () { set(T_LONG_size , T_LONG ); }
172 void do_void () { set(T_VOID_size , T_VOID ); }
173 void do_object(int begin, int end) { set(T_OBJECT_size , T_OBJECT ); }
174 void do_array (int begin, int end) { set(T_ARRAY_size , T_ARRAY ); }
175
176 public:
177 SignatureInfo(Symbol* signature) : SignatureIterator(signature) {
178 _has_iterated = _has_iterated_return = false;
179 _size = 0;
180 _return_type = T_ILLEGAL;
181 }
182
183 };
184
185
186 // Specialized SignatureIterator: Used to compute the argument size.
187
188 class ArgumentSizeComputer: public SignatureInfo {
189 private:
190 void set(int size, BasicType type) { _size += size; }
191 public:
192 ArgumentSizeComputer(Symbol* signature) : SignatureInfo(signature) {}
193
194 int size() { lazy_iterate_parameters(); return _size; }
195 };
196
197
198 class ArgumentCount: public SignatureInfo {
199 private:
200 void set(int size, BasicType type) { _size ++; }
201 public:
202 ArgumentCount(Symbol* signature) : SignatureInfo(signature) {}
203
204 int size() { lazy_iterate_parameters(); return _size; }
205 };
206
207
208 // Specialized SignatureIterator: Used to compute the result type.
209
210 class ResultTypeFinder: public SignatureInfo {
211 private:
212 void set(int size, BasicType type) { _return_type = type; }
213 public:
214 BasicType type() { lazy_iterate_return(); return _return_type; }
215
216 ResultTypeFinder(Symbol* signature) : SignatureInfo(signature) {}
217 };
218
219
220 // Fingerprinter computes a unique ID for a given method. The ID
221 // is a bitvector characterizing the methods signature (incl. the receiver).
222 class Fingerprinter: public SignatureIterator {
223 private:
224 uint64_t _fingerprint;
225 int _shift_count;
226 methodHandle mh;
227
228 public:
229
230 void do_bool() { _fingerprint |= (((uint64_t)bool_parm) << _shift_count); _shift_count += parameter_feature_size; }
231 void do_char() { _fingerprint |= (((uint64_t)char_parm) << _shift_count); _shift_count += parameter_feature_size; }
232 void do_byte() { _fingerprint |= (((uint64_t)byte_parm) << _shift_count); _shift_count += parameter_feature_size; }
233 void do_short() { _fingerprint |= (((uint64_t)short_parm) << _shift_count); _shift_count += parameter_feature_size; }
234 void do_int() { _fingerprint |= (((uint64_t)int_parm) << _shift_count); _shift_count += parameter_feature_size; }
235 void do_long() { _fingerprint |= (((uint64_t)long_parm) << _shift_count); _shift_count += parameter_feature_size; }
236 void do_float() { _fingerprint |= (((uint64_t)float_parm) << _shift_count); _shift_count += parameter_feature_size; }
237 void do_double() { _fingerprint |= (((uint64_t)double_parm) << _shift_count); _shift_count += parameter_feature_size; }
238
239 void do_object(int begin, int end) { _fingerprint |= (((uint64_t)obj_parm) << _shift_count); _shift_count += parameter_feature_size; }
240 void do_array (int begin, int end) { _fingerprint |= (((uint64_t)obj_parm) << _shift_count); _shift_count += parameter_feature_size; }
241
242 void do_void() { ShouldNotReachHere(); }
243
244 Fingerprinter(const methodHandle& method) : SignatureIterator(method->signature()) {
245 mh = method;
246 _fingerprint = 0;
247 }
248
249 uint64_t fingerprint() {
250 // See if we fingerprinted this method already
251 if (mh->constMethod()->fingerprint() != CONST64(0)) {
252 return mh->constMethod()->fingerprint();
253 }
254
255 if (mh->size_of_parameters() > max_size_of_parameters ) {
256 _fingerprint = (uint64_t)CONST64(-1);
257 mh->constMethod()->set_fingerprint(_fingerprint);
258 return _fingerprint;
259 }
260
261 assert( (int)mh->result_type() <= (int)result_feature_mask, "bad result type");
262 _fingerprint = mh->result_type();
263 _fingerprint <<= static_feature_size;
264 if (mh->is_static()) _fingerprint |= 1;
265 _shift_count = result_feature_size + static_feature_size;
266 iterate_parameters();
267 _fingerprint |= ((uint64_t)done_parm) << _shift_count;// mark end of sig
268 mh->constMethod()->set_fingerprint(_fingerprint);
269 return _fingerprint;
270 }
271 };
272
273
274 // Specialized SignatureIterator: Used for native call purposes
275
276 class NativeSignatureIterator: public SignatureIterator {
277 private:
278 methodHandle _method;
279 // We need separate JNI and Java offset values because in 64 bit mode,
280 // the argument offsets are not in sync with the Java stack.
281 // For example a long takes up 1 "C" stack entry but 2 Java stack entries.
282 int _offset; // The java stack offset
283 int _prepended; // number of prepended JNI parameters (1 JNIEnv, plus 1 mirror if static)
284 int _jni_offset; // the current parameter offset, starting with 0
285
286 void do_bool () { pass_int(); _jni_offset++; _offset++; }
287 void do_char () { pass_int(); _jni_offset++; _offset++; }
288 void do_float () { pass_float(); _jni_offset++; _offset++; }
289 #ifdef _LP64
290 void do_double() { pass_double(); _jni_offset++; _offset += 2; }
291 #else
292 void do_double() { pass_double(); _jni_offset += 2; _offset += 2; }
293 #endif
294 void do_byte () { pass_int(); _jni_offset++; _offset++; }
295 void do_short () { pass_int(); _jni_offset++; _offset++; }
296 void do_int () { pass_int(); _jni_offset++; _offset++; }
297 #ifdef _LP64
298 void do_long () { pass_long(); _jni_offset++; _offset += 2; }
299 #else
300 void do_long () { pass_long(); _jni_offset += 2; _offset += 2; }
301 #endif
302 void do_void () { ShouldNotReachHere(); }
303 void do_object(int begin, int end) { pass_object(); _jni_offset++; _offset++; }
304 void do_array (int begin, int end) { pass_object(); _jni_offset++; _offset++; }
305 void do_valuetype(int begin, int end){ pass_valuetype(); _jni_offset++; _offset++; }
306
307 public:
308 methodHandle method() const { return _method; }
309 int offset() const { return _offset; }
310 int jni_offset() const { return _jni_offset + _prepended; }
311 // int java_offset() const { return method()->size_of_parameters() - _offset - 1; }
312 bool is_static() const { return method()->is_static(); }
313 virtual void pass_int() = 0;
314 virtual void pass_long() = 0;
315 virtual void pass_object() = 0;
316 virtual void pass_valuetype() = 0;
317 virtual void pass_float() = 0;
318 #ifdef _LP64
319 virtual void pass_double() = 0;
320 #else
321 virtual void pass_double() { pass_long(); } // may be same as long
322 #endif
323
324 NativeSignatureIterator(const methodHandle& method) : SignatureIterator(method->signature()) {
325 _method = method;
326 _offset = 0;
327 _jni_offset = 0;
328
329 const int JNIEnv_words = 1;
330 const int mirror_words = 1;
331 _prepended = !is_static() ? JNIEnv_words : JNIEnv_words + mirror_words;
332 }
333
334 // iterate() calles the 2 virtual methods according to the following invocation syntax:
335 //
336 // {pass_int | pass_long | pass_object}
337 //
338 // Arguments are handled from left to right (receiver first, if any).
339 // The offset() values refer to the Java stack offsets but are 0 based and increasing.
340 // The java_offset() values count down to 0, and refer to the Java TOS.
341 // The jni_offset() values increase from 1 or 2, and refer to C arguments.
342
343 void iterate() { iterate(Fingerprinter(method()).fingerprint());
344 }
345
346
347 // Optimized path if we have the bitvector form of signature
348 void iterate( uint64_t fingerprint ) {
349
350 if (!is_static()) {
351 // handle receiver (not handled by iterate because not in signature)
352 pass_object(); _jni_offset++; _offset++;
353 }
354
355 SignatureIterator::iterate_parameters( fingerprint );
356 }
357 };
358
359
360 // Handy stream for iterating over signature
361
362 class SignatureStream : public StackObj {
363 private:
364 Symbol* _signature;
365 int _begin;
366 int _end;
367 BasicType _type;
368 bool _at_return_type;
369 GrowableArray<Symbol*>* _names; // symbols created while parsing signature
370
371 public:
372 bool at_return_type() const { return _at_return_type; }
373 bool is_done() const;
374 void next_non_primitive(int t);
375 void next() {
376 Symbol* sig = _signature;
377 int len = sig->utf8_length();
378 if (_end >= len) {
379 _end = len + 1;
380 return;
381 }
382
383 _begin = _end;
384 int t = sig->byte_at(_begin);
385 switch (t) {
386 case 'B': _type = T_BYTE; break;
387 case 'C': _type = T_CHAR; break;
388 case 'D': _type = T_DOUBLE; break;
389 case 'F': _type = T_FLOAT; break;
390 case 'I': _type = T_INT; break;
391 case 'J': _type = T_LONG; break;
392 case 'S': _type = T_SHORT; break;
393 case 'Z': _type = T_BOOLEAN; break;
394 case 'V': _type = T_VOID; break;
395 default : next_non_primitive(t);
396 return;
397 }
398 _end++;
399 }
400
401 SignatureStream(Symbol* signature, bool is_method = true);
402 ~SignatureStream();
403
404 bool is_object() const; // True if this argument is an object
405 bool is_array() const; // True if this argument is an array
406 BasicType type() const { return _type; }
407 Symbol* as_symbol(TRAPS);
408 enum FailureMode { ReturnNull, CNFException, NCDFError };
409 Klass* as_klass(Handle class_loader, Handle protection_domain, FailureMode failure_mode, TRAPS);
410 oop as_java_mirror(Handle class_loader, Handle protection_domain, FailureMode failure_mode, TRAPS);
411 const jbyte* raw_bytes() { return _signature->bytes() + _begin; }
412 int raw_length() { return _end - _begin; }
413
414 // return same as_symbol except allocation of new symbols is avoided.
415 Symbol* as_symbol_or_null();
416
417 // count the number of references in the signature
418 int reference_parameter_count();
419 };
420
421 class SignatureVerifier : public StackObj {
422 public:
423 // Returns true if the symbol is valid method or type signature
424 static bool is_valid_signature(Symbol* sig);
425
426 static bool is_valid_method_signature(Symbol* sig);
427 static bool is_valid_type_signature(Symbol* sig);
428 private:
429
430 static ssize_t is_valid_type(const char*, ssize_t);
431 static bool invalid_name_char(char);
432 };
433
434 // Used for adapter generation. One SigEntry is used per element of
435 // the signature of the method. Value type arguments are treated
436 // specially. See comment for ValueKlass::collect_fields().
437 class SigEntry VALUE_OBJ_CLASS_SPEC {
438 public:
439 BasicType _bt;
440 int _offset;
441
442 SigEntry()
443 : _bt(T_ILLEGAL), _offset(-1) {
444 }
445 SigEntry(BasicType bt, int offset)
446 : _bt(bt), _offset(offset) {}
447
448 SigEntry(BasicType bt)
449 : _bt(bt), _offset(-1) {}
450
451 static int compare(SigEntry* e1, SigEntry* e2) {
452 if (e1->_offset != e2->_offset) {
453 return e1->_offset - e2->_offset;
454 }
455 assert((e1->_bt == T_LONG && (e2->_bt == T_LONG || e2->_bt == T_VOID)) ||
456 (e1->_bt == T_DOUBLE && (e2->_bt == T_DOUBLE || e2->_bt == T_VOID)) ||
457 e1->_bt == T_VALUETYPE || e2->_bt == T_VALUETYPE || e1->_bt == T_VOID || e2->_bt == T_VOID, "bad bt");
458 if (e1->_bt == e2->_bt) {
459 assert(e1->_bt == T_VALUETYPE || e1->_bt == T_VOID, "only ones with duplicate offsets");
460 return 0;
461 }
462 if (e1->_bt == T_VOID ||
463 e2->_bt == T_VALUETYPE) {
464 return 1;
465 }
466 if (e1->_bt == T_VALUETYPE ||
467 e2->_bt == T_VOID) {
468 return -1;
469 }
470 ShouldNotReachHere();
471 return 0;
472 }
473 static int count_fields(const GrowableArray<SigEntry>& sig_extended);
474 static void fill_sig_bt(const GrowableArray<SigEntry>& sig_extended, BasicType* sig_bt_cc, int total_args_passed_cc, bool skip_vt);
475 };
476
477 #endif // SHARE_VM_RUNTIME_SIGNATURE_HPP