1 /*
2 * Copyright (c) 1997, 2023, Oracle and/or its affiliates. All rights reserved.
3 * Copyright (c) 2021, Azul Systems, Inc. All rights reserved.
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This code is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 only, as
8 * published by the Free Software Foundation.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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24 */
25
26 #ifndef SHARE_RUNTIME_SIGNATURE_HPP
27 #define SHARE_RUNTIME_SIGNATURE_HPP
28
29 #include "classfile/symbolTable.hpp"
30 #include "memory/allocation.hpp"
31 #include "oops/method.hpp"
32
33
34 // Static routines and parsing loops for processing field and method
35 // descriptors. In the HotSpot sources we call them "signatures".
36 //
37 // A SignatureStream iterates over a Java descriptor (or parts of it).
38 // The syntax is documented in the Java Virtual Machine Specification,
39 // section 4.3.
40 //
41 // The syntax may be summarized as follows:
42 //
43 // MethodType: '(' {FieldType}* ')' (FieldType | 'V')
44 // FieldType: PrimitiveType | ObjectType | ArrayType
45 // PrimitiveType: 'B' | 'C' | 'D' | 'F' | 'I' | 'J' | 'S' | 'Z'
46 // ObjectType: 'L' ClassName ';' | ArrayType
47 // ArrayType: '[' FieldType
48 // ClassName: {UnqualifiedName '/'}* UnqualifiedName
49 // UnqualifiedName: NameChar {NameChar}*
50 // NameChar: ANY_CHAR_EXCEPT('/' | '.' | ';' | '[')
51 //
52 // All of the concrete characters in the above grammar are given
53 // standard manifest constant names of the form JVM_SIGNATURE_x.
54 // Executable code uses these constant names in preference to raw
55 // character constants. Comments and assertion code sometimes use
56 // the raw character constants for brevity.
57 //
58 // The primitive field types (like 'I') correspond 1-1 with type codes
59 // (like T_INT) which form part of the specification of the 'newarray'
60 // instruction (JVMS 6.5, section on newarray). These type codes are
61 // widely used in the HotSpot code. They are joined by ad hoc codes
62 // like T_OBJECT and T_ARRAY (defined in HotSpot but not in the JVMS)
63 // so that each "basic type" of field descriptor (or void return type)
64 // has a corresponding T_x code. Thus, while T_x codes play a very
65 // minor role in the JVMS, they play a major role in the HotSpot
66 // sources. There are fewer than 16 such "basic types", so they fit
67 // nicely into bitfields.
68 //
69 // The syntax of ClassName overlaps slightly with the descriptor
70 // syntaxes. The strings "I" and "(I)V" are both class names
71 // *and* descriptors. If a class name contains any character other
72 // than "BCDFIJSZ()V" it cannot be confused with a descriptor.
73 // Class names inside of descriptors are always contained in an
74 // "envelope" syntax which starts with 'L' and ends with ';'.
75 //
76 // As a confounding factor, array types report their type name strings
77 // in descriptor format. These name strings are easy to recognize,
78 // since they begin with '['. For this reason some API points on
79 // HotSpot look for array descriptors as well as proper class names.
80 //
81 // For historical reasons some API points that accept class names and
82 // array names also look for class names wrapped inside an envelope
83 // (like "LFoo;") and unwrap them on the fly (to a name like "Foo").
84
85 class Signature : AllStatic {
86 private:
87 static bool is_valid_array_signature(const Symbol* sig);
88
89 public:
90
91 // Returns the basic type of a field signature (or T_VOID for "V").
92 // Assumes the signature is a valid field descriptor.
93 // Do not apply this function to class names or method signatures.
94 static BasicType basic_type(const Symbol* signature) {
95 return basic_type(signature->char_at(0));
96 }
97
98 // Returns T_ILLEGAL for an illegal signature char.
99 static BasicType basic_type(int ch);
100
101 // Assuming it is either a class name or signature,
102 // determine if it in fact is an array descriptor.
103 static bool is_array(const Symbol* signature) {
104 return (signature->utf8_length() > 1 &&
105 signature->char_at(0) == JVM_SIGNATURE_ARRAY &&
106 is_valid_array_signature(signature));
107 }
108
109 // Assuming it is either a class name or signature,
110 // determine if it contains a class name plus ';'.
111 static bool has_envelope(const Symbol* signature) {
112 return ((signature->utf8_length() > 0) &&
113 signature->ends_with(JVM_SIGNATURE_ENDCLASS) &&
114 has_envelope(signature->char_at(0)));
115 }
116
117 // Determine if this signature char introduces an
118 // envelope, which is a class name plus ';'.
119 static bool has_envelope(char signature_char) {
120 return (signature_char == JVM_SIGNATURE_CLASS);
121 }
122
123 // Assuming has_envelope is true, return the symbol
124 // inside the envelope, by stripping 'L' and ';'.
125 // Caller is responsible for decrementing the newly created
126 // Symbol's refcount, use TempNewSymbol.
127 static Symbol* strip_envelope(const Symbol* signature);
128
129 // Assuming it's either a field or method descriptor, determine
130 // whether it is in fact a method descriptor:
131 static bool is_method(const Symbol* signature) {
132 return signature->starts_with(JVM_SIGNATURE_FUNC);
133 }
134
135 // Assuming it's a method signature, determine if it must
136 // return void.
137 static bool is_void_method(const Symbol* signature) {
138 assert(is_method(signature), "signature is not for a method");
139 return signature->ends_with(JVM_SIGNATURE_VOID);
140 }
141 };
142
143 // A SignatureIterator uses a SignatureStream to produce BasicType
144 // results, discarding class names. This means it can be accelerated
145 // using a fingerprint mechanism, in many cases, without loss of type
146 // information. The FingerPrinter class computes and caches this
147 // reduced information for faster iteration.
148
149 class SignatureIterator: public ResourceObj {
150 public:
151 typedef uint64_t fingerprint_t;
152
153 protected:
154 Symbol* _signature; // the signature to iterate over
155 BasicType _return_type;
156 fingerprint_t _fingerprint;
157
158 public:
159 // Definitions used in generating and iterating the
160 // bit field form of the signature generated by the
161 // Fingerprinter.
162 enum {
163 fp_static_feature_size = 1,
164 fp_is_static_bit = 1,
165
166 fp_result_feature_size = 4,
167 fp_result_feature_mask = right_n_bits(fp_result_feature_size),
168 fp_parameter_feature_size = 4,
169 fp_parameter_feature_mask = right_n_bits(fp_parameter_feature_size),
170
171 fp_parameters_done = 0, // marker for end of parameters (must be zero)
172
173 // Parameters take up full wordsize, minus the result and static bit fields.
174 // Since fp_parameters_done is zero, termination field arises from shifting
175 // in zero bits, and therefore occupies no extra space.
176 // The sentinel value is all-zero-bits, which is impossible for a true
177 // fingerprint, since at least the result field will be non-zero.
178 fp_max_size_of_parameters = ((BitsPerLong
179 - (fp_result_feature_size + fp_static_feature_size))
180 / fp_parameter_feature_size)
181 };
182
183 static bool fp_is_valid_type(BasicType type, bool for_return_type = false);
184
185 // Sentinel values are zero and not-zero (-1).
186 // No need to protect the sign bit, since every valid return type is non-zero
187 // (even T_VOID), and there are no valid parameter fields which are 0xF (T_VOID).
188 static fingerprint_t zero_fingerprint() { return (fingerprint_t)0; }
189 static fingerprint_t overflow_fingerprint() { return ~(fingerprint_t)0; }
190 static bool fp_is_valid(fingerprint_t fingerprint) {
191 return (fingerprint != zero_fingerprint()) && (fingerprint != overflow_fingerprint());
192 }
193
194 // Constructors
195 SignatureIterator(Symbol* signature, fingerprint_t fingerprint = zero_fingerprint()) {
196 _signature = signature;
197 _return_type = T_ILLEGAL; // sentinel value for uninitialized
198 _fingerprint = zero_fingerprint();
199 if (fingerprint != _fingerprint) {
200 set_fingerprint(fingerprint);
201 }
202 }
203
204 // If the fingerprint is present, we can use an accelerated loop.
205 void set_fingerprint(fingerprint_t fingerprint);
206
207 // Returns the set fingerprint, or zero_fingerprint()
208 // if none has been set already.
209 fingerprint_t fingerprint() const { return _fingerprint; }
210
211 // Iteration
212 // Hey look: There are no virtual methods in this class.
213 // So how is it customized? By calling do_parameters_on
214 // an object which answers to "do_type(BasicType)".
215 // By convention, this object is in the subclass
216 // itself, so the call is "do_parameters_on(this)".
217 // The effect of this is to inline the parsing loop
218 // everywhere "do_parameters_on" is called.
219 // If there is a valid fingerprint in the object,
220 // an improved loop is called which just unpacks the
221 // bitfields from the fingerprint. Otherwise, the
222 // symbol is parsed.
223 template<typename T> inline void do_parameters_on(T* callback); // iterates over parameters only
224 BasicType return_type(); // computes the value on the fly if necessary
225
226 static BasicType fp_return_type(fingerprint_t fingerprint) {
227 assert(fp_is_valid(fingerprint), "invalid fingerprint");
228 return (BasicType) ((fingerprint >> fp_static_feature_size) & fp_result_feature_mask);
229 }
230 static fingerprint_t fp_start_parameters(fingerprint_t fingerprint) {
231 assert(fp_is_valid(fingerprint), "invalid fingerprint");
232 return fingerprint >> (fp_static_feature_size + fp_result_feature_size);
233 }
234 static BasicType fp_next_parameter(fingerprint_t& mask) {
235 int result = (mask & fp_parameter_feature_mask);
236 mask >>= fp_parameter_feature_size;
237 return (BasicType) result;
238 }
239 };
240
241
242 // Specialized SignatureIterators: Used to compute signature specific values.
243
244 class SignatureTypeNames : public SignatureIterator {
245 protected:
246 virtual void type_name(const char* name) = 0;
247
248 friend class SignatureIterator; // so do_parameters_on can call do_type
249 void do_type(BasicType type) {
250 switch (type) {
251 case T_BOOLEAN: type_name("jboolean"); break;
252 case T_CHAR: type_name("jchar" ); break;
253 case T_FLOAT: type_name("jfloat" ); break;
254 case T_DOUBLE: type_name("jdouble" ); break;
255 case T_BYTE: type_name("jbyte" ); break;
256 case T_SHORT: type_name("jshort" ); break;
257 case T_INT: type_name("jint" ); break;
258 case T_LONG: type_name("jlong" ); break;
259 case T_VOID: type_name("void" ); break;
260 case T_ARRAY:
261 case T_OBJECT: type_name("jobject" ); break;
262 default: ShouldNotReachHere();
263 }
264 }
265
266 public:
267 SignatureTypeNames(Symbol* signature) : SignatureIterator(signature) {}
268 };
269
270
271 // Specialized SignatureIterator: Used to compute the argument size.
272
273 class ArgumentSizeComputer: public SignatureIterator {
274 private:
275 int _size;
276 friend class SignatureIterator; // so do_parameters_on can call do_type
277 void do_type(BasicType type) { _size += parameter_type_word_count(type); }
278 public:
279 ArgumentSizeComputer(Symbol* signature);
280 int size() { return _size; }
281 };
282
283
284 class ArgumentCount: public SignatureIterator {
285 private:
286 int _size;
287 friend class SignatureIterator; // so do_parameters_on can call do_type
288 void do_type(BasicType type) { _size++; }
289 public:
290 ArgumentCount(Symbol* signature);
291 int size() { return _size; }
292 };
293
294
295 class ReferenceArgumentCount: public SignatureIterator {
296 private:
297 int _refs;
298 friend class SignatureIterator; // so do_parameters_on can call do_type
299 void do_type(BasicType type) { if (is_reference_type(type)) _refs++; }
300 public:
301 ReferenceArgumentCount(Symbol* signature);
302 int count() { return _refs; }
303 };
304
305
306 // Specialized SignatureIterator: Used to compute the result type.
307
308 class ResultTypeFinder: public SignatureIterator {
309 public:
310 BasicType type() { return return_type(); }
311 ResultTypeFinder(Symbol* signature) : SignatureIterator(signature) { }
312 };
313
314
315 // Fingerprinter computes a unique ID for a given method. The ID
316 // is a bitvector characterizing the methods signature (incl. the receiver).
317 class Fingerprinter: public SignatureIterator {
318 private:
319 fingerprint_t _accumulator;
320 int _param_size;
321 int _stack_arg_slots;
322 int _shift_count;
323 const Method* _method;
324
325 uint _int_args;
326 uint _fp_args;
327
328 void initialize_accumulator() {
329 _accumulator = 0;
330 _shift_count = fp_result_feature_size + fp_static_feature_size;
331 _param_size = 0;
332 _stack_arg_slots = 0;
333 }
334
335 // Out-of-line method does it all in constructor:
336 void compute_fingerprint_and_return_type(bool static_flag = false);
337
338 void initialize_calling_convention(bool static_flag);
339 void do_type_calling_convention(BasicType type);
340
341 friend class SignatureIterator; // so do_parameters_on can call do_type
342 void do_type(BasicType type) {
343 assert(fp_is_valid_type(type), "bad parameter type");
344 _accumulator |= ((fingerprint_t)type << _shift_count);
345 _shift_count += fp_parameter_feature_size;
346 _param_size += (is_double_word_type(type) ? 2 : 1);
347 do_type_calling_convention(type);
348 }
349
350 public:
351 int size_of_parameters() const { return _param_size; }
352 int num_stack_arg_slots() const { return _stack_arg_slots; }
353
354 // fingerprint() and return_type() are in super class
355
356 Fingerprinter(const methodHandle& method)
357 : SignatureIterator(method->signature()),
358 _method(method()) {
359 compute_fingerprint_and_return_type();
360 }
361 Fingerprinter(Symbol* signature, bool is_static)
362 : SignatureIterator(signature),
363 _method(nullptr) {
364 compute_fingerprint_and_return_type(is_static);
365 }
366 };
367
368
369 // Specialized SignatureIterator: Used for native call purposes
370
371 class NativeSignatureIterator: public SignatureIterator {
372 private:
373 methodHandle _method;
374 // We need separate JNI and Java offset values because in 64 bit mode,
375 // the argument offsets are not in sync with the Java stack.
376 // For example a long takes up 1 "C" stack entry but 2 Java stack entries.
377 int _offset; // The java stack offset
378 int _prepended; // number of prepended JNI parameters (1 JNIEnv, plus 1 mirror if static)
379 int _jni_offset; // the current parameter offset, starting with 0
380
381 friend class SignatureIterator; // so do_parameters_on can call do_type
382 void do_type(BasicType type) {
383 switch (type) {
384 case T_BYTE:
385 case T_BOOLEAN:
386 pass_byte(); _jni_offset++; _offset++;
387 break;
388 case T_CHAR:
389 case T_SHORT:
390 pass_short(); _jni_offset++; _offset++;
391 break;
392 case T_INT:
393 pass_int(); _jni_offset++; _offset++;
394 break;
395 case T_FLOAT:
396 pass_float(); _jni_offset++; _offset++;
397 break;
398 case T_DOUBLE: {
399 int jni_offset = LP64_ONLY(1) NOT_LP64(2);
400 pass_double(); _jni_offset += jni_offset; _offset += 2;
401 break;
402 }
403 case T_LONG: {
404 int jni_offset = LP64_ONLY(1) NOT_LP64(2);
405 pass_long(); _jni_offset += jni_offset; _offset += 2;
406 break;
407 }
408 case T_ARRAY:
409 case T_OBJECT:
410 pass_object(); _jni_offset++; _offset++;
411 break;
412 default:
413 ShouldNotReachHere();
414 }
415 }
416
417 public:
418 methodHandle method() const { return _method; }
419 int offset() const { return _offset; }
420 int jni_offset() const { return _jni_offset + _prepended; }
421 bool is_static() const { return method()->is_static(); }
422 virtual void pass_int() = 0;
423 virtual void pass_long() = 0;
424 virtual void pass_object() = 0; // objects, arrays, inlines
425 virtual void pass_float() = 0;
426 virtual void pass_byte() { pass_int(); };
427 virtual void pass_short() { pass_int(); };
428 #ifdef _LP64
429 virtual void pass_double() = 0;
430 #else
431 virtual void pass_double() { pass_long(); } // may be same as long
432 #endif
433
434 NativeSignatureIterator(const methodHandle& method) : SignatureIterator(method->signature()) {
435 _method = method;
436 _offset = 0;
437 _jni_offset = 0;
438
439 const int JNIEnv_words = 1;
440 const int mirror_words = 1;
441 _prepended = !is_static() ? JNIEnv_words : JNIEnv_words + mirror_words;
442 }
443
444 void iterate() { iterate(Fingerprinter(method()).fingerprint()); }
445
446 // iterate() calls the 3 virtual methods according to the following invocation syntax:
447 //
448 // {pass_int | pass_long | pass_object}
449 //
450 // Arguments are handled from left to right (receiver first, if any).
451 // The offset() values refer to the Java stack offsets but are 0 based and increasing.
452 // The java_offset() values count down to 0, and refer to the Java TOS.
453 // The jni_offset() values increase from 1 or 2, and refer to C arguments.
454 // The method's return type is ignored.
455
456 void iterate(fingerprint_t fingerprint) {
457 set_fingerprint(fingerprint);
458 if (!is_static()) {
459 // handle receiver (not handled by iterate because not in signature)
460 pass_object(); _jni_offset++; _offset++;
461 }
462 do_parameters_on(this);
463 }
464 };
465
466
467 // This is the core parsing logic for iterating over signatures.
468 // All of the previous classes use this for doing their work.
469
470 class SignatureStream : public StackObj {
471 private:
472 const Symbol* _signature;
473 int _begin;
474 int _end;
475 int _limit;
476 int _array_prefix; // count of '[' before the array element descr
477 BasicType _type;
478 int _state;
479 Symbol* _previous_name; // cache the previously looked up symbol to avoid lookups
480 GrowableArray<Symbol*>* _names; // symbols created while parsing that need to be dereferenced
481
482 Symbol* find_symbol();
483
484 enum { _s_field = 0, _s_method = 1, _s_method_return = 3 };
485 void set_done() {
486 _state |= -2; // preserve s_method bit
487 assert(is_done(), "Unable to set state to done");
488 }
489 int scan_type(BasicType bt);
490
491 public:
492 bool at_return_type() const { return _state == (int)_s_method_return; }
493 bool is_done() const { return _state < 0; }
494 void next();
495
496 SignatureStream(const Symbol* signature, bool is_method = true);
497 ~SignatureStream();
498
499 bool is_reference() const { return is_reference_type(_type); }
500 bool is_array() const { return _type == T_ARRAY; }
501 BasicType type() const { return _type; }
502
503 const u1* raw_bytes() const { return _signature->bytes() + _begin; }
504 int raw_length() const { return _end - _begin; }
505 int raw_symbol_begin() const { return _begin + (has_envelope() ? 1 : 0); }
506 int raw_symbol_end() const { return _end - (has_envelope() ? 1 : 0); }
507 char raw_char_at(int i) const {
508 assert(i < _limit, "index for raw_char_at is over the limit");
509 return _signature->char_at(i);
510 }
511
512 // True if there is an embedded class name in this type,
513 // followed by ';'.
514 bool has_envelope() const {
515 if (!Signature::has_envelope(_signature->char_at(_begin)))
516 return false;
517 // this should always be true, but let's test it:
518 assert(_signature->char_at(_end-1) == JVM_SIGNATURE_ENDCLASS, "signature envelope has no semi-colon at end");
519 return true;
520 }
521
522 // return the symbol for chars in symbol_begin()..symbol_end()
523 Symbol* as_symbol() {
524 return find_symbol();
525 }
526
527 // in case you want only the return type:
528 void skip_to_return_type();
529
530 // number of '[' in array prefix
531 int array_prefix_length() {
532 return _type == T_ARRAY ? _array_prefix : 0;
533 }
534
535 // In case you want only the array base type,
536 // reset the stream after skipping some brackets '['.
537 // (The argument is clipped to array_prefix_length(),
538 // and if it ends up as zero this call is a nop.
539 // The default is value skips all brackets '['.)
540 private:
541 int skip_whole_array_prefix();
542 public:
543 int skip_array_prefix(int max_skip_length) {
544 if (_type != T_ARRAY) {
545 return 0;
546 }
547 if (_array_prefix > max_skip_length) {
548 // strip some but not all levels of T_ARRAY
549 _array_prefix -= max_skip_length;
550 _begin += max_skip_length;
551 return max_skip_length;
552 }
553 return skip_whole_array_prefix();
554 }
555 int skip_array_prefix() {
556 if (_type != T_ARRAY) {
557 return 0;
558 }
559 return skip_whole_array_prefix();
560 }
561
562 // free-standing lookups (bring your own CL/PD pair)
563 enum FailureMode { ReturnNull, NCDFError, CachedOrNull };
564
565 Klass* as_klass(Handle class_loader, Handle protection_domain, FailureMode failure_mode, TRAPS);
566 InlineKlass* as_inline_klass(InstanceKlass* holder);
567 oop as_java_mirror(Handle class_loader, Handle protection_domain, FailureMode failure_mode, TRAPS);
568 };
569
570 class SigEntryFilter;
571 typedef GrowableArrayFilterIterator<SigEntry, SigEntryFilter> ExtendedSignature;
572
573 // Used for adapter generation. One SigEntry is used per element of
574 // the signature of the method. Inline type arguments are treated
575 // specially. See comment for InlineKlass::collect_fields().
576 class SigEntry {
577 public:
578 BasicType _bt;
579 int _offset;
580 Symbol* _symbol;
581
582 SigEntry()
583 : _bt(T_ILLEGAL), _offset(-1), _symbol(NULL) {}
584
585 SigEntry(BasicType bt, int offset, Symbol* symbol)
586 : _bt(bt), _offset(offset), _symbol(symbol) {}
587
588 static int compare(SigEntry* e1, SigEntry* e2) {
589 if (e1->_offset != e2->_offset) {
590 return e1->_offset - e2->_offset;
591 }
592 assert((e1->_bt == T_LONG && (e2->_bt == T_LONG || e2->_bt == T_VOID)) ||
593 (e1->_bt == T_DOUBLE && (e2->_bt == T_DOUBLE || e2->_bt == T_VOID)) ||
594 e1->_bt == T_METADATA || e2->_bt == T_METADATA || e1->_bt == T_VOID || e2->_bt == T_VOID, "bad bt");
595 if (e1->_bt == e2->_bt) {
596 assert(e1->_bt == T_METADATA || e1->_bt == T_VOID, "only ones with duplicate offsets");
597 return 0;
598 }
599 if (e1->_bt == T_VOID ||
600 e2->_bt == T_METADATA) {
601 return 1;
602 }
603 if (e1->_bt == T_METADATA ||
604 e2->_bt == T_VOID) {
605 return -1;
606 }
607 ShouldNotReachHere();
608 return 0;
609 }
610 static void add_entry(GrowableArray<SigEntry>* sig, BasicType bt, Symbol* symbol, int offset = -1);
611 static bool skip_value_delimiters(const GrowableArray<SigEntry>* sig, int i);
612 static int fill_sig_bt(const GrowableArray<SigEntry>* sig, BasicType* sig_bt);
613 static TempNewSymbol create_symbol(const GrowableArray<SigEntry>* sig);
614 };
615
616 class SigEntryFilter {
617 public:
618 bool operator()(const SigEntry& entry) { return entry._bt != T_METADATA && entry._bt != T_VOID; }
619 };
620
621 // Specialized SignatureStream: used for invoking SystemDictionary to either find
622 // or resolve the underlying type when iterating over a
623 // Java descriptor (or parts of it).
624 class ResolvingSignatureStream : public SignatureStream {
625 Klass* _load_origin;
626 bool _handles_cached;
627 Handle _class_loader; // cached when needed
628 Handle _protection_domain; // cached when needed
629
630 void initialize_load_origin(Klass* load_origin) {
631 _load_origin = load_origin;
632 _handles_cached = (load_origin == nullptr);
633 }
634 void need_handles() {
635 if (!_handles_cached) {
636 cache_handles();
637 _handles_cached = true;
638 }
639 }
640 void cache_handles();
641
642 public:
643 ResolvingSignatureStream(Symbol* signature, Klass* load_origin, bool is_method = true);
644 ResolvingSignatureStream(Symbol* signature, Handle class_loader, Handle protection_domain, bool is_method = true);
645 ResolvingSignatureStream(const Method* method);
646
647 Klass* as_klass(FailureMode failure_mode, TRAPS) {
648 need_handles();
649 return SignatureStream::as_klass(_class_loader, _protection_domain,
650 failure_mode, THREAD);
651 }
652 oop as_java_mirror(FailureMode failure_mode, TRAPS) {
653 if (is_reference()) {
654 need_handles();
655 }
656 return SignatureStream::as_java_mirror(_class_loader, _protection_domain,
657 failure_mode, THREAD);
658 }
659 };
660
661 // Here is how all the SignatureIterator classes invoke the
662 // SignatureStream engine to do their parsing.
663 template<typename T> inline
664 void SignatureIterator::do_parameters_on(T* callback) {
665 fingerprint_t unaccumulator = _fingerprint;
666
667 // Check for too many arguments, or missing fingerprint:
668 if (!fp_is_valid(unaccumulator)) {
669 SignatureStream ss(_signature);
670 for (; !ss.at_return_type(); ss.next()) {
671 callback->do_type(ss.type());
672 }
673 // while we are here, capture the return type
674 _return_type = ss.type();
675 } else {
676 // Optimized version of do_parameters when fingerprint is known
677 assert(_return_type != T_ILLEGAL, "return type already captured from fp");
678 unaccumulator = fp_start_parameters(unaccumulator);
679 for (BasicType type; (type = fp_next_parameter(unaccumulator)) != (BasicType)fp_parameters_done; ) {
680 assert(fp_is_valid_type(type), "garbled fingerprint");
681 callback->do_type(type);
682 }
683 }
684 }
685
686 #ifdef ASSERT
687 class SignatureVerifier : public StackObj {
688 public:
689 static bool is_valid_method_signature(const Symbol* sig);
690 static bool is_valid_type_signature(const Symbol* sig);
691 private:
692 static ssize_t is_valid_type(const char*, ssize_t);
693 };
694 #endif
695 #endif // SHARE_RUNTIME_SIGNATURE_HPP