1 /*
2 * Copyright (c) 1997, 2023, 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 "asm/assembler.hpp"
27 #include "classfile/symbolTable.hpp"
28 #include "classfile/systemDictionary.hpp"
29 #include "classfile/vmSymbols.hpp"
30 #include "memory/oopFactory.hpp"
31 #include "memory/resourceArea.hpp"
32 #include "memory/universe.hpp"
33 #include "oops/instanceKlass.hpp"
34 #include "oops/klass.inline.hpp"
35 #include "oops/oop.inline.hpp"
36 #include "oops/symbol.hpp"
37 #include "oops/typeArrayKlass.hpp"
38 #include "oops/inlineKlass.inline.hpp"
39 #include "runtime/fieldDescriptor.inline.hpp"
40 #include "runtime/handles.inline.hpp"
41 #include "runtime/interfaceSupport.inline.hpp"
42 #include "runtime/safepointVerifiers.hpp"
43 #include "runtime/sharedRuntime.hpp"
44 #include "runtime/signature.hpp"
45 #include "runtime/sharedRuntime.hpp"
46
47 // Implementation of SignatureIterator
48
49 // Signature syntax:
50 //
51 // Signature = "(" {Parameter} ")" ReturnType.
52 // Parameter = FieldType.
53 // ReturnType = FieldType | "V".
54 // FieldType = "B" | "C" | "D" | "F" | "I" | "J" | "S" | "Z" | "L" ClassName ";" | "Q" ValueClassName ";" | "[" FieldType.
55 // ClassName = string.
56
57 // The ClassName string can be any JVM-style UTF8 string except:
58 // - an empty string (the empty string is never a name of any kind)
59 // - a string which begins or ends with slash '/' (the package separator)
60 // - a string which contains adjacent slashes '//' (no empty package names)
61 // - a string which contains a semicolon ';' (the end-delimiter)
62 // - a string which contains a left bracket '[' (the array marker)
63 // - a string which contains a dot '.' (the external package separator)
64 //
65 // Other "meta-looking" characters, such as '(' and '<' and '+',
66 // are perfectly legitimate within a class name, for the JVM.
67 // Class names which contain double slashes ('a//b') and non-initial
68 // brackets ('a[b]') are reserved for possible enrichment of the
69 // type language.
70
71 void SignatureIterator::set_fingerprint(fingerprint_t fingerprint) {
72 if (!fp_is_valid(fingerprint)) {
73 _fingerprint = fingerprint;
74 _return_type = T_ILLEGAL;
75 } else if (fingerprint != _fingerprint) {
76 assert(_fingerprint == zero_fingerprint(), "consistent fingerprint values");
77 _fingerprint = fingerprint;
78 _return_type = fp_return_type(fingerprint);
79 }
80 }
81
82 BasicType SignatureIterator::return_type() {
83 if (_return_type == T_ILLEGAL) {
84 SignatureStream ss(_signature);
85 ss.skip_to_return_type();
86 _return_type = ss.type();
87 assert(_return_type != T_ILLEGAL, "illegal return type");
88 }
89 return _return_type;
90 }
91
92 bool SignatureIterator::fp_is_valid_type(BasicType type, bool for_return_type) {
93 assert(type != (BasicType)fp_parameters_done, "fingerprint is incorrectly at done");
94 assert(((int)type & ~fp_parameter_feature_mask) == 0, "fingerprint feature mask yielded non-zero value");
95 return (is_java_primitive(type) ||
96 is_reference_type(type) ||
97 (for_return_type && type == T_VOID));
98 }
99
100 ArgumentSizeComputer::ArgumentSizeComputer(Symbol* signature)
101 : SignatureIterator(signature)
102 {
103 _size = 0;
104 do_parameters_on(this); // non-virtual template execution
105 }
106
107 ArgumentCount::ArgumentCount(Symbol* signature)
108 : SignatureIterator(signature)
109 {
110 _size = 0;
111 do_parameters_on(this); // non-virtual template execution
112 }
113
114 ReferenceArgumentCount::ReferenceArgumentCount(Symbol* signature)
115 : SignatureIterator(signature)
116 {
117 _refs = 0;
118 do_parameters_on(this); // non-virtual template execution
119 }
120
121 #if !defined(_LP64) || defined(ZERO) || defined(ASSERT)
122 static int compute_num_stack_arg_slots(Symbol* signature, int sizeargs, bool is_static) {
123 ResourceMark rm;
124 BasicType* sig_bt = NEW_RESOURCE_ARRAY(BasicType, sizeargs);
125 VMRegPair* regs = NEW_RESOURCE_ARRAY(VMRegPair, sizeargs);
126
127 int sig_index = 0;
128 if (!is_static) {
129 sig_bt[sig_index++] = T_OBJECT; // 'this'
130 }
131 for (SignatureStream ss(signature); !ss.at_return_type(); ss.next()) {
132 BasicType t = ss.type();
133 assert(type2size[t] == 1 || type2size[t] == 2, "size is 1 or 2");
134 sig_bt[sig_index++] = t;
135 if (type2size[t] == 2) {
136 sig_bt[sig_index++] = T_VOID;
137 }
138 }
139 assert(sig_index == sizeargs, "sig_index: %d sizeargs: %d", sig_index, sizeargs);
140
141 return SharedRuntime::java_calling_convention(sig_bt, regs, sizeargs);
142 }
143 #endif
144
145 void Fingerprinter::compute_fingerprint_and_return_type(bool static_flag) {
146 // See if we fingerprinted this method already
147 if (_method != nullptr) {
148 assert(!static_flag, "must not be passed by caller");
149 static_flag = _method->is_static();
150 _fingerprint = _method->constMethod()->fingerprint();
151
152 if (_fingerprint != zero_fingerprint()) {
153 _return_type = _method->result_type();
154 assert(is_java_type(_return_type), "return type must be a java type");
155 return;
156 }
157
158 if (_method->size_of_parameters() > fp_max_size_of_parameters) {
159 _fingerprint = overflow_fingerprint();
160 _method->constMethod()->set_fingerprint(_fingerprint);
161 // as long as we are here compute the return type:
162 _return_type = ResultTypeFinder(_method->signature()).type();
163 assert(is_java_type(_return_type), "return type must be a java type");
164 return;
165 }
166 }
167
168 // Note: This will always take the slow path, since _fp==zero_fp.
169 initialize_accumulator();
170 initialize_calling_convention(static_flag);
171 do_parameters_on(this);
172 assert(fp_is_valid_type(_return_type, true), "bad result type");
173
174 // Fill in the return type and static bits:
175 _accumulator |= _return_type << fp_static_feature_size;
176 if (static_flag) {
177 _accumulator |= fp_is_static_bit;
178 } else {
179 _param_size += 1; // this is the convention for Method::compute_size_of_parameters
180 }
181
182 #if defined(_LP64) && !defined(ZERO)
183 _stack_arg_slots = align_up(_stack_arg_slots, 2);
184 #ifdef ASSERT
185 int dbg_stack_arg_slots = compute_num_stack_arg_slots(_signature, _param_size, static_flag);
186 assert(_stack_arg_slots == dbg_stack_arg_slots, "fingerprinter: %d full: %d", _stack_arg_slots, dbg_stack_arg_slots);
187 #endif
188 #else
189 // Fallback: computed _stack_arg_slots is unreliable, compute directly.
190 _stack_arg_slots = compute_num_stack_arg_slots(_signature, _param_size, static_flag);
191 #endif
192
193 // Detect overflow. (We counted _param_size correctly.)
194 if (_method == nullptr && _param_size > fp_max_size_of_parameters) {
195 // We did a one-pass computation of argument size, return type,
196 // and fingerprint.
197 _fingerprint = overflow_fingerprint();
198 return;
199 }
200
201 assert(_shift_count < BitsPerLong,
202 "shift count overflow %d (%d vs. %d): %s",
203 _shift_count, _param_size, fp_max_size_of_parameters,
204 _signature->as_C_string());
205 assert((_accumulator >> _shift_count) == fp_parameters_done, "must be zero");
206
207 // This is the result, along with _return_type:
208 _fingerprint = _accumulator;
209
210 // Cache the result on the method itself:
211 if (_method != nullptr) {
212 _method->constMethod()->set_fingerprint(_fingerprint);
213 }
214 }
215
216 void Fingerprinter::initialize_calling_convention(bool static_flag) {
217 _int_args = 0;
218 _fp_args = 0;
219
220 if (!static_flag) { // `this` takes up an int register
221 _int_args++;
222 }
223 }
224
225 void Fingerprinter::do_type_calling_convention(BasicType type) {
226 // We compute the number of slots for stack-passed arguments in compiled calls.
227 // TODO: SharedRuntime::java_calling_convention is the shared code that knows all details
228 // about the platform-specific calling conventions. This method tries to compute the stack
229 // args number... poorly, at least for 32-bit ports and for zero. Current code has the fallback
230 // that recomputes the stack args number from SharedRuntime::java_calling_convention.
231 #if defined(_LP64) && !defined(ZERO)
232 switch (type) {
233 case T_VOID:
234 break;
235 case T_BOOLEAN:
236 case T_CHAR:
237 case T_BYTE:
238 case T_SHORT:
239 case T_INT:
240 #if defined(PPC64) || defined(S390)
241 if (_int_args < Argument::n_int_register_parameters_j) {
242 _int_args++;
243 } else {
244 _stack_arg_slots += 1;
245 }
246 break;
247 #endif // defined(PPC64) || defined(S390)
248 case T_LONG:
249 case T_OBJECT:
250 case T_ARRAY:
251 case T_ADDRESS:
252 case T_PRIMITIVE_OBJECT:
253 if (_int_args < Argument::n_int_register_parameters_j) {
254 _int_args++;
255 } else {
256 PPC64_ONLY(_stack_arg_slots = align_up(_stack_arg_slots, 2));
257 S390_ONLY(_stack_arg_slots = align_up(_stack_arg_slots, 2));
258 _stack_arg_slots += 2;
259 }
260 break;
261 case T_FLOAT:
262 #if defined(PPC64) || defined(S390)
263 if (_fp_args < Argument::n_float_register_parameters_j) {
264 _fp_args++;
265 } else {
266 _stack_arg_slots += 1;
267 }
268 break;
269 #endif // defined(PPC64) || defined(S390)
270 case T_DOUBLE:
271 if (_fp_args < Argument::n_float_register_parameters_j) {
272 _fp_args++;
273 } else {
274 PPC64_ONLY(_stack_arg_slots = align_up(_stack_arg_slots, 2));
275 S390_ONLY(_stack_arg_slots = align_up(_stack_arg_slots, 2));
276 _stack_arg_slots += 2;
277 }
278 break;
279 default:
280 ShouldNotReachHere();
281 break;
282 }
283 #endif
284 }
285
286 // Implementation of SignatureStream
287
288 static inline BasicType decode_signature_char(int ch) {
289 switch (ch) {
290 #define EACH_SIG(ch, bt, ignore) \
291 case ch: return bt;
292 SIGNATURE_TYPES_DO(EACH_SIG, ignore)
293 #undef EACH_SIG
294 }
295 return (BasicType)0;
296 }
297
298 SignatureStream::SignatureStream(const Symbol* signature,
299 bool is_method) {
300 assert(!is_method || signature->starts_with(JVM_SIGNATURE_FUNC),
301 "method signature required");
302 _signature = signature;
303 _limit = signature->utf8_length();
304 int oz = (is_method ? _s_method : _s_field);
305 _state = oz;
306 _begin = _end = oz; // skip first '(' in method signatures
307 _array_prefix = 0; // just for definiteness
308
309 // assigning java/lang/Object to _previous_name means we can
310 // avoid a number of null checks in the parser
311 _previous_name = vmSymbols::java_lang_Object();
312 _names = nullptr;
313 next();
314 }
315
316 SignatureStream::~SignatureStream() {
317 if (_previous_name == vmSymbols::java_lang_Object()) {
318 // no names were created
319 assert(_names == nullptr, "_names unexpectedly created");
320 return;
321 }
322
323 // decrement refcount for names created during signature parsing
324 _previous_name->decrement_refcount();
325 if (_names != nullptr) {
326 for (int i = 0; i < _names->length(); i++) {
327 _names->at(i)->decrement_refcount();
328 }
329 }
330 }
331
332 inline int SignatureStream::scan_type(BasicType type) {
333 const u1* base = _signature->bytes();
334 int end = _end;
335 int limit = _limit;
336 const u1* tem;
337 switch (type) {
338 case T_OBJECT:
339 case T_PRIMITIVE_OBJECT:
340 tem = (const u1*) memchr(&base[end], JVM_SIGNATURE_ENDCLASS, limit - end);
341 return (tem == nullptr ? limit : pointer_delta_as_int(tem + 1, base));
342
343 case T_ARRAY:
344 while ((end < limit) && ((char)base[end] == JVM_SIGNATURE_ARRAY)) { end++; }
345 // If we discovered only the string of '[', this means something is wrong.
346 if (end >= limit) {
347 assert(false, "Invalid type detected");
348 return limit;
349 }
350 _array_prefix = end - _end; // number of '[' chars just skipped
351 if (Signature::has_envelope(base[end])) {
352 tem = (const u1 *) memchr(&base[end], JVM_SIGNATURE_ENDCLASS, limit - end);
353 return (tem == nullptr ? limit : pointer_delta_as_int(tem + 1, base));
354 }
355 // Skipping over a single character for a primitive type.
356 assert(is_java_primitive(decode_signature_char(base[end])), "only primitives expected");
357 return end + 1;
358
359 default:
360 // Skipping over a single character for a primitive type (or void).
361 assert(!is_reference_type(type), "only primitives or void expected");
362 return end + 1;
363 }
364 }
365
366 void SignatureStream::next() {
367 const Symbol* sig = _signature;
368 int len = _limit;
369 if (_end >= len) { set_done(); return; }
370 _begin = _end;
371 int ch = sig->char_at(_begin);
372 if (ch == JVM_SIGNATURE_ENDFUNC) {
373 assert(_state == _s_method, "must be in method");
374 _state = _s_method_return;
375 _begin = ++_end;
376 if (_end >= len) { set_done(); return; }
377 ch = sig->char_at(_begin);
378 }
379 BasicType bt = decode_signature_char(ch);
380 assert(ch == type2char(bt), "bad signature char %c/%d", ch, ch);
381 _type = bt;
382 _end = scan_type(bt);
383 }
384
385 int SignatureStream::skip_whole_array_prefix() {
386 assert(_type == T_ARRAY, "must be");
387
388 // we are stripping all levels of T_ARRAY,
389 // so we must decode the next character
390 int whole_array_prefix = _array_prefix;
391 int new_begin = _begin + whole_array_prefix;
392 _begin = new_begin;
393 int ch = _signature->char_at(new_begin);
394 BasicType bt = decode_signature_char(ch);
395 assert(ch == type2char(bt), "bad signature char %c/%d", ch, ch);
396 _type = bt;
397 assert(bt != T_VOID && bt != T_ARRAY, "bad signature type");
398 // Don't bother to re-scan, since it won't change the value of _end.
399 return whole_array_prefix;
400 }
401
402 bool Signature::is_valid_array_signature(const Symbol* sig) {
403 assert(sig->utf8_length() > 1, "this should already have been checked");
404 assert(sig->char_at(0) == JVM_SIGNATURE_ARRAY, "this should already have been checked");
405 // The first character is already checked
406 int i = 1;
407 int len = sig->utf8_length();
408 // First skip all '['s
409 while(i < len - 1 && sig->char_at(i) == JVM_SIGNATURE_ARRAY) i++;
410
411 // Check type
412 switch(sig->char_at(i)) {
413 case JVM_SIGNATURE_BYTE:
414 case JVM_SIGNATURE_CHAR:
415 case JVM_SIGNATURE_DOUBLE:
416 case JVM_SIGNATURE_FLOAT:
417 case JVM_SIGNATURE_INT:
418 case JVM_SIGNATURE_LONG:
419 case JVM_SIGNATURE_SHORT:
420 case JVM_SIGNATURE_BOOLEAN:
421 // If it is an array, the type is the last character
422 return (i + 1 == len);
423 case JVM_SIGNATURE_CLASS:
424 case JVM_SIGNATURE_PRIMITIVE_OBJECT:
425 // If it is an object, the last character must be a ';'
426 return sig->char_at(len - 1) == JVM_SIGNATURE_ENDCLASS;
427 }
428 return false;
429 }
430
431 BasicType Signature::basic_type(int ch) {
432 BasicType btcode = decode_signature_char(ch);
433 if (btcode == 0) return T_ILLEGAL;
434 return btcode;
435 }
436
437 Symbol* Signature::strip_envelope(const Symbol* signature) {
438 assert(has_envelope(signature), "precondition");
439 return SymbolTable::new_symbol((char*) signature->bytes() + 1,
440 signature->utf8_length() - 2);
441 }
442
443 static const int jl_len = 10, object_len = 6, jl_object_len = jl_len + object_len;
444 static const char jl_str[] = "java/lang/";
445
446 #ifdef ASSERT
447 static bool signature_symbols_sane() {
448 static bool done;
449 if (done) return true;
450 done = true;
451 // test some tense code that looks for common symbol names:
452 assert(vmSymbols::java_lang_Object()->utf8_length() == jl_object_len &&
453 vmSymbols::java_lang_Object()->starts_with(jl_str, jl_len) &&
454 vmSymbols::java_lang_Object()->ends_with("Object", object_len) &&
455 vmSymbols::java_lang_Object()->is_permanent() &&
456 vmSymbols::java_lang_String()->utf8_length() == jl_object_len &&
457 vmSymbols::java_lang_String()->starts_with(jl_str, jl_len) &&
458 vmSymbols::java_lang_String()->ends_with("String", object_len) &&
459 vmSymbols::java_lang_String()->is_permanent(),
460 "sanity");
461 return true;
462 }
463 #endif //ASSERT
464
465 // returns a symbol; the caller is responsible for decrementing it
466 Symbol* SignatureStream::find_symbol() {
467 // Create a symbol from for string _begin _end
468 int begin = raw_symbol_begin();
469 int end = raw_symbol_end();
470
471 const char* symbol_chars = (const char*)_signature->base() + begin;
472 int len = end - begin;
473
474 // Quick check for common symbols in signatures
475 assert(signature_symbols_sane(), "incorrect signature sanity check");
476 if (len == jl_object_len &&
477 memcmp(symbol_chars, jl_str, jl_len) == 0) {
478 if (memcmp("String", symbol_chars + jl_len, object_len) == 0) {
479 return vmSymbols::java_lang_String();
480 } else if (memcmp("Object", symbol_chars + jl_len, object_len) == 0) {
481 return vmSymbols::java_lang_Object();
482 }
483 }
484
485 Symbol* name = _previous_name;
486 if (name->equals(symbol_chars, len)) {
487 return name;
488 }
489
490 // Save names for cleaning up reference count at the end of
491 // SignatureStream scope.
492 name = SymbolTable::new_symbol(symbol_chars, len);
493
494 // Only allocate the GrowableArray for the _names buffer if more than
495 // one name is being processed in the signature.
496 if (!_previous_name->is_permanent()) {
497 if (_names == nullptr) {
498 _names = new GrowableArray<Symbol*>(10);
499 }
500 _names->push(_previous_name);
501 }
502 _previous_name = name;
503 return name;
504 }
505
506 InlineKlass* SignatureStream::as_inline_klass(InstanceKlass* holder) {
507 ThreadInVMfromUnknown tiv;
508 JavaThread* THREAD = JavaThread::current();
509 HandleMark hm(THREAD);
510 Handle class_loader(THREAD, holder->class_loader());
511 Handle protection_domain(THREAD, holder->protection_domain());
512 Klass* k = as_klass(class_loader, protection_domain, SignatureStream::CachedOrNull, THREAD);
513 assert(!HAS_PENDING_EXCEPTION, "Should never throw");
514 if (k != nullptr && k->is_inline_klass()) {
515 return InlineKlass::cast(k);
516 } else {
517 return nullptr;
518 }
519 }
520
521 Klass* SignatureStream::as_klass(Handle class_loader, Handle protection_domain,
522 FailureMode failure_mode, TRAPS) {
523 if (!is_reference()) {
524 return nullptr;
525 }
526 Symbol* name = as_symbol();
527 Klass* k = nullptr;
528 if (failure_mode == ReturnNull) {
529 // Note: SD::resolve_or_null returns null for most failure modes,
530 // but not all. Circularity errors, invalid PDs, etc., throw.
531 k = SystemDictionary::resolve_or_null(name, class_loader, protection_domain, CHECK_NULL);
532 } else if (failure_mode == CachedOrNull) {
533 NoSafepointVerifier nsv; // no loading, now, we mean it!
534 assert(!HAS_PENDING_EXCEPTION, "");
535 k = SystemDictionary::find_instance_klass(THREAD, name, class_loader, protection_domain);
536 // SD::find does not trigger loading, so there should be no throws
537 // Still, bad things can happen, so we CHECK_NULL and ask callers
538 // to do likewise.
539 return k;
540 } else {
541 // The only remaining failure mode is NCDFError.
542 // The test here allows for an additional mode CNFException
543 // if callers need to request the reflective error instead.
544 bool throw_error = (failure_mode == NCDFError);
545 k = SystemDictionary::resolve_or_fail(name, class_loader, protection_domain, throw_error, CHECK_NULL);
546 }
547
548 return k;
549 }
550
551 oop SignatureStream::as_java_mirror(Handle class_loader, Handle protection_domain,
552 FailureMode failure_mode, TRAPS) {
553 if (!is_reference()) {
554 return Universe::java_mirror(type());
555 }
556 Klass* klass = as_klass(class_loader, protection_domain, failure_mode, CHECK_NULL);
557 if (klass == nullptr) {
558 return nullptr;
559 }
560 return has_Q_descriptor() ? InlineKlass::cast(klass)->val_mirror()
561 : klass->java_mirror();
562 }
563
564 void SignatureStream::skip_to_return_type() {
565 while (!at_return_type()) {
566 next();
567 }
568 }
569
570 ResolvingSignatureStream::ResolvingSignatureStream(Symbol* signature,
571 Handle class_loader,
572 Handle protection_domain,
573 bool is_method)
574 : SignatureStream(signature, is_method),
575 _class_loader(class_loader), _protection_domain(protection_domain)
576 {
577 initialize_load_origin(nullptr);
578 }
579
580 ResolvingSignatureStream::ResolvingSignatureStream(Symbol* signature, Klass* load_origin, bool is_method)
581 : SignatureStream(signature, is_method)
582 {
583 assert(load_origin != nullptr, "");
584 initialize_load_origin(load_origin);
585 }
586
587 ResolvingSignatureStream::ResolvingSignatureStream(const Method* method)
588 : SignatureStream(method->signature(), true)
589 {
590 initialize_load_origin(method->method_holder());
591 }
592
593 void ResolvingSignatureStream::cache_handles() {
594 assert(_load_origin != nullptr, "");
595 JavaThread* current = JavaThread::current();
596 _class_loader = Handle(current, _load_origin->class_loader());
597 _protection_domain = Handle(current, _load_origin->protection_domain());
598 }
599
600 #ifdef ASSERT
601 extern bool signature_constants_sane(); // called from basic_types_init()
602
603 bool signature_constants_sane() {
604 // for the lookup table, test every 8-bit code point, and then some:
605 for (int i = -256; i <= 256; i++) {
606 int btcode = 0;
607 switch (i) {
608 #define EACH_SIG(ch, bt, ignore) \
609 case ch: { btcode = bt; break; }
610 SIGNATURE_TYPES_DO(EACH_SIG, ignore)
611 #undef EACH_SIG
612 }
613 int btc = decode_signature_char(i);
614 assert(btc == btcode, "misconfigured table: %d => %d not %d", i, btc, btcode);
615 }
616 return true;
617 }
618
619 bool SignatureVerifier::is_valid_method_signature(const Symbol* sig) {
620 const char* method_sig = (const char*)sig->bytes();
621 ssize_t len = sig->utf8_length();
622 ssize_t index = 0;
623 if (method_sig != nullptr && len > 1 && method_sig[index] == JVM_SIGNATURE_FUNC) {
624 ++index;
625 while (index < len && method_sig[index] != JVM_SIGNATURE_ENDFUNC) {
626 ssize_t res = is_valid_type(&method_sig[index], len - index);
627 if (res == -1) {
628 return false;
629 } else {
630 index += res;
631 }
632 }
633 if (index < len && method_sig[index] == JVM_SIGNATURE_ENDFUNC) {
634 // check the return type
635 ++index;
636 return (is_valid_type(&method_sig[index], len - index) == (len - index));
637 }
638 }
639 return false;
640 }
641
642 bool SignatureVerifier::is_valid_type_signature(const Symbol* sig) {
643 const char* type_sig = (const char*)sig->bytes();
644 ssize_t len = sig->utf8_length();
645 return (type_sig != nullptr && len >= 1 &&
646 (is_valid_type(type_sig, len) == len));
647 }
648
649 // Checks to see if the type (not to go beyond 'limit') refers to a valid type.
650 // Returns -1 if it is not, or the index of the next character that is not part
651 // of the type. The type encoding may end before 'limit' and that's ok.
652 ssize_t SignatureVerifier::is_valid_type(const char* type, ssize_t limit) {
653 ssize_t index = 0;
654
655 // Iterate over any number of array dimensions
656 while (index < limit && type[index] == JVM_SIGNATURE_ARRAY) ++index;
657 if (index >= limit) {
658 return -1;
659 }
660 switch (type[index]) {
661 case JVM_SIGNATURE_BYTE:
662 case JVM_SIGNATURE_CHAR:
663 case JVM_SIGNATURE_FLOAT:
664 case JVM_SIGNATURE_DOUBLE:
665 case JVM_SIGNATURE_INT:
666 case JVM_SIGNATURE_LONG:
667 case JVM_SIGNATURE_SHORT:
668 case JVM_SIGNATURE_BOOLEAN:
669 case JVM_SIGNATURE_VOID:
670 return index + 1;
671 case JVM_SIGNATURE_PRIMITIVE_OBJECT: // fall through
672 case JVM_SIGNATURE_CLASS:
673 for (index = index + 1; index < limit; ++index) {
674 char c = type[index];
675 switch (c) {
676 case JVM_SIGNATURE_ENDCLASS:
677 return index + 1;
678 case '\0': case JVM_SIGNATURE_DOT: case JVM_SIGNATURE_ARRAY:
679 return -1;
680 default: ; // fall through
681 }
682 }
683 // fall through
684 default: ; // fall through
685 }
686 return -1;
687 }
688
689 #endif // ASSERT
690
691 // Adds an argument to the signature
692 void SigEntry::add_entry(GrowableArray<SigEntry>* sig, BasicType bt, Symbol* symbol, int offset) {
693 sig->append(SigEntry(bt, offset, symbol));
694 if (bt == T_LONG || bt == T_DOUBLE) {
695 sig->append(SigEntry(T_VOID, offset, symbol)); // Longs and doubles take two stack slots
696 }
697 }
698
699 // Returns true if the argument at index 'i' is not an inline type delimiter
700 bool SigEntry::skip_value_delimiters(const GrowableArray<SigEntry>* sig, int i) {
701 return (sig->at(i)._bt != T_METADATA &&
702 (sig->at(i)._bt != T_VOID || sig->at(i-1)._bt == T_LONG || sig->at(i-1)._bt == T_DOUBLE));
703 }
704
705 // Fill basic type array from signature array
706 int SigEntry::fill_sig_bt(const GrowableArray<SigEntry>* sig, BasicType* sig_bt) {
707 int count = 0;
708 for (int i = 0; i < sig->length(); i++) {
709 if (skip_value_delimiters(sig, i)) {
710 sig_bt[count++] = sig->at(i)._bt;
711 }
712 }
713 return count;
714 }
715
716 // Create a temporary symbol from the signature array
717 TempNewSymbol SigEntry::create_symbol(const GrowableArray<SigEntry>* sig) {
718 ResourceMark rm;
719 int length = sig->length();
720 char* sig_str = NEW_RESOURCE_ARRAY(char, 2*length + 3);
721 int idx = 0;
722 sig_str[idx++] = '(';
723 for (int i = 0; i < length; i++) {
724 BasicType bt = sig->at(i)._bt;
725 if (bt == T_METADATA || bt == T_VOID) {
726 // Ignore
727 } else {
728 if (bt == T_ARRAY) {
729 bt = T_OBJECT; // We don't know the element type, treat as Object
730 }
731 sig_str[idx++] = type2char(bt);
732 if (bt == T_OBJECT) {
733 sig_str[idx++] = ';';
734 }
735 }
736 }
737 sig_str[idx++] = ')';
738 // Add a dummy return type. It won't be used but SignatureStream needs it.
739 sig_str[idx++] = 'V';
740 sig_str[idx++] = '\0';
741 return SymbolTable::new_symbol(sig_str);
742 }