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 #ifdef ASSERT
184 int dbg_stack_arg_slots = compute_num_stack_arg_slots(_signature, _param_size, static_flag);
185 assert(_stack_arg_slots == dbg_stack_arg_slots, "fingerprinter: %d full: %d", _stack_arg_slots, dbg_stack_arg_slots);
186 #endif
187 #else
188 // Fallback: computed _stack_arg_slots is unreliable, compute directly.
189 _stack_arg_slots = compute_num_stack_arg_slots(_signature, _param_size, static_flag);
190 #endif
191
192 // Detect overflow. (We counted _param_size correctly.)
193 if (_method == nullptr && _param_size > fp_max_size_of_parameters) {
194 // We did a one-pass computation of argument size, return type,
195 // and fingerprint.
196 _fingerprint = overflow_fingerprint();
197 return;
198 }
199
200 assert(_shift_count < BitsPerLong,
201 "shift count overflow %d (%d vs. %d): %s",
202 _shift_count, _param_size, fp_max_size_of_parameters,
203 _signature->as_C_string());
204 assert((_accumulator >> _shift_count) == fp_parameters_done, "must be zero");
205
206 // This is the result, along with _return_type:
207 _fingerprint = _accumulator;
208
209 // Cache the result on the method itself:
210 if (_method != nullptr) {
211 _method->constMethod()->set_fingerprint(_fingerprint);
212 }
213 }
214
215 void Fingerprinter::initialize_calling_convention(bool static_flag) {
216 _int_args = 0;
217 _fp_args = 0;
218
219 if (!static_flag) { // `this` takes up an int register
220 _int_args++;
221 }
222 }
223
224 void Fingerprinter::do_type_calling_convention(BasicType type) {
225 // We compute the number of slots for stack-passed arguments in compiled calls.
226 // TODO: SharedRuntime::java_calling_convention is the shared code that knows all details
227 // about the platform-specific calling conventions. This method tries to compute the stack
228 // args number... poorly, at least for 32-bit ports and for zero. Current code has the fallback
229 // that recomputes the stack args number from SharedRuntime::java_calling_convention.
230 #if defined(_LP64) && !defined(ZERO)
231 switch (type) {
232 case T_VOID:
233 break;
234 case T_BOOLEAN:
235 case T_CHAR:
236 case T_BYTE:
237 case T_SHORT:
238 case T_INT:
239 if (_int_args < Argument::n_int_register_parameters_j) {
240 _int_args++;
241 } else {
242 #if defined(PPC64) || defined(S390)
243 _stack_arg_slots += 1;
244 #else
245 _stack_arg_slots = align_up(_stack_arg_slots, 2);
246 _stack_arg_slots += 1;
247 #endif // defined(PPC64) || defined(S390)
248 }
249 break;
250 case T_LONG:
251 case T_OBJECT:
252 case T_ARRAY:
253 case T_ADDRESS:
254 if (_int_args < Argument::n_int_register_parameters_j) {
255 _int_args++;
256 } else {
257 _stack_arg_slots = align_up(_stack_arg_slots, 2);
258 _stack_arg_slots += 2;
259 }
260 break;
261 case T_FLOAT:
262 if (_fp_args < Argument::n_float_register_parameters_j) {
263 _fp_args++;
264 } else {
265 #if defined(PPC64) || defined(S390)
266 _stack_arg_slots += 1;
267 #else
268 _stack_arg_slots = align_up(_stack_arg_slots, 2);
269 _stack_arg_slots += 1;
270 #endif // defined(PPC64) || defined(S390)
271 }
272 break;
273 case T_DOUBLE:
274 if (_fp_args < Argument::n_float_register_parameters_j) {
275 _fp_args++;
276 } else {
277 _stack_arg_slots = align_up(_stack_arg_slots, 2);
278 _stack_arg_slots += 2;
279 }
280 break;
281 default:
282 ShouldNotReachHere();
283 break;
284 }
285 #endif
286 }
287
288 // Implementation of SignatureStream
289
290 static inline BasicType decode_signature_char(int ch) {
291 switch (ch) {
292 #define EACH_SIG(ch, bt, ignore) \
293 case ch: return bt;
294 SIGNATURE_TYPES_DO(EACH_SIG, ignore)
295 #undef EACH_SIG
296 }
297 return (BasicType)0;
298 }
299
300 SignatureStream::SignatureStream(const Symbol* signature,
301 bool is_method) {
302 assert(!is_method || signature->starts_with(JVM_SIGNATURE_FUNC),
303 "method signature required");
304 _signature = signature;
305 _limit = signature->utf8_length();
306 int oz = (is_method ? _s_method : _s_field);
307 _state = oz;
308 _begin = _end = oz; // skip first '(' in method signatures
309 _array_prefix = 0; // just for definiteness
310
311 // assigning java/lang/Object to _previous_name means we can
312 // avoid a number of null checks in the parser
313 _previous_name = vmSymbols::java_lang_Object();
314 _names = nullptr;
315 next();
316 }
317
318 SignatureStream::~SignatureStream() {
319 if (_previous_name == vmSymbols::java_lang_Object()) {
320 // no names were created
321 assert(_names == nullptr, "_names unexpectedly created");
322 return;
323 }
324
325 // decrement refcount for names created during signature parsing
326 _previous_name->decrement_refcount();
327 if (_names != nullptr) {
328 for (int i = 0; i < _names->length(); i++) {
329 _names->at(i)->decrement_refcount();
330 }
331 }
332 }
333
334 inline int SignatureStream::scan_type(BasicType type) {
335 const u1* base = _signature->bytes();
336 int end = _end;
337 int limit = _limit;
338 const u1* tem;
339 switch (type) {
340 case T_OBJECT:
341 tem = (const u1*) memchr(&base[end], JVM_SIGNATURE_ENDCLASS, limit - end);
342 return (tem == nullptr ? limit : pointer_delta_as_int(tem + 1, base));
343
344 case T_ARRAY:
345 while ((end < limit) && ((char)base[end] == JVM_SIGNATURE_ARRAY)) { end++; }
346 // If we discovered only the string of '[', this means something is wrong.
347 if (end >= limit) {
348 assert(false, "Invalid type detected");
349 return limit;
350 }
351 _array_prefix = end - _end; // number of '[' chars just skipped
352 if (Signature::has_envelope(base[end])) {
353 tem = (const u1 *) memchr(&base[end], JVM_SIGNATURE_ENDCLASS, limit - end);
354 return (tem == nullptr ? limit : pointer_delta_as_int(tem + 1, base));
355 }
356 // Skipping over a single character for a primitive type.
357 assert(is_java_primitive(decode_signature_char(base[end])), "only primitives expected");
358 return end + 1;
359
360 default:
361 // Skipping over a single character for a primitive type (or void).
362 assert(!is_reference_type(type), "only primitives or void expected");
363 return end + 1;
364 }
365 }
366
367 void SignatureStream::next() {
368 const Symbol* sig = _signature;
369 int len = _limit;
370 if (_end >= len) { set_done(); return; }
371 _begin = _end;
372 int ch = sig->char_at(_begin);
373 if (ch == JVM_SIGNATURE_ENDFUNC) {
374 assert(_state == _s_method, "must be in method");
375 _state = _s_method_return;
376 _begin = ++_end;
377 if (_end >= len) { set_done(); return; }
378 ch = sig->char_at(_begin);
379 }
380 BasicType bt = decode_signature_char(ch);
381 assert(ch == type2char(bt), "bad signature char %c/%d", ch, ch);
382 _type = bt;
383 _end = scan_type(bt);
384 }
385
386 int SignatureStream::skip_whole_array_prefix() {
387 assert(_type == T_ARRAY, "must be");
388
389 // we are stripping all levels of T_ARRAY,
390 // so we must decode the next character
391 int whole_array_prefix = _array_prefix;
392 int new_begin = _begin + whole_array_prefix;
393 _begin = new_begin;
394 int ch = _signature->char_at(new_begin);
395 BasicType bt = decode_signature_char(ch);
396 assert(ch == type2char(bt), "bad signature char %c/%d", ch, ch);
397 _type = bt;
398 assert(bt != T_VOID && bt != T_ARRAY, "bad signature type");
399 // Don't bother to re-scan, since it won't change the value of _end.
400 return whole_array_prefix;
401 }
402
403 bool Signature::is_valid_array_signature(const Symbol* sig) {
404 assert(sig->utf8_length() > 1, "this should already have been checked");
405 assert(sig->char_at(0) == JVM_SIGNATURE_ARRAY, "this should already have been checked");
406 // The first character is already checked
407 int i = 1;
408 int len = sig->utf8_length();
409 // First skip all '['s
410 while(i < len - 1 && sig->char_at(i) == JVM_SIGNATURE_ARRAY) i++;
411
412 // Check type
413 switch(sig->char_at(i)) {
414 case JVM_SIGNATURE_BYTE:
415 case JVM_SIGNATURE_CHAR:
416 case JVM_SIGNATURE_DOUBLE:
417 case JVM_SIGNATURE_FLOAT:
418 case JVM_SIGNATURE_INT:
419 case JVM_SIGNATURE_LONG:
420 case JVM_SIGNATURE_SHORT:
421 case JVM_SIGNATURE_BOOLEAN:
422 // If it is an array, the type is the last character
423 return (i + 1 == len);
424 case JVM_SIGNATURE_CLASS:
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 klass->java_mirror();
561 }
562
563 void SignatureStream::skip_to_return_type() {
564 while (!at_return_type()) {
565 next();
566 }
567 }
568
569 ResolvingSignatureStream::ResolvingSignatureStream(Symbol* signature,
570 Handle class_loader,
571 Handle protection_domain,
572 bool is_method)
573 : SignatureStream(signature, is_method),
574 _class_loader(class_loader), _protection_domain(protection_domain)
575 {
576 initialize_load_origin(nullptr);
577 }
578
579 ResolvingSignatureStream::ResolvingSignatureStream(Symbol* signature, Klass* load_origin, bool is_method)
580 : SignatureStream(signature, is_method)
581 {
582 assert(load_origin != nullptr, "");
583 initialize_load_origin(load_origin);
584 }
585
586 ResolvingSignatureStream::ResolvingSignatureStream(const Method* method)
587 : SignatureStream(method->signature(), true)
588 {
589 initialize_load_origin(method->method_holder());
590 }
591
592 void ResolvingSignatureStream::cache_handles() {
593 assert(_load_origin != nullptr, "");
594 JavaThread* current = JavaThread::current();
595 _class_loader = Handle(current, _load_origin->class_loader());
596 _protection_domain = Handle(current, _load_origin->protection_domain());
597 }
598
599 #ifdef ASSERT
600 extern bool signature_constants_sane(); // called from basic_types_init()
601
602 bool signature_constants_sane() {
603 // for the lookup table, test every 8-bit code point, and then some:
604 for (int i = -256; i <= 256; i++) {
605 int btcode = 0;
606 switch (i) {
607 #define EACH_SIG(ch, bt, ignore) \
608 case ch: { btcode = bt; break; }
609 SIGNATURE_TYPES_DO(EACH_SIG, ignore)
610 #undef EACH_SIG
611 }
612 int btc = decode_signature_char(i);
613 assert(btc == btcode, "misconfigured table: %d => %d not %d", i, btc, btcode);
614 }
615 return true;
616 }
617
618 bool SignatureVerifier::is_valid_method_signature(const Symbol* sig) {
619 const char* method_sig = (const char*)sig->bytes();
620 ssize_t len = sig->utf8_length();
621 ssize_t index = 0;
622 if (method_sig != nullptr && len > 1 && method_sig[index] == JVM_SIGNATURE_FUNC) {
623 ++index;
624 while (index < len && method_sig[index] != JVM_SIGNATURE_ENDFUNC) {
625 ssize_t res = is_valid_type(&method_sig[index], len - index);
626 if (res == -1) {
627 return false;
628 } else {
629 index += res;
630 }
631 }
632 if (index < len && method_sig[index] == JVM_SIGNATURE_ENDFUNC) {
633 // check the return type
634 ++index;
635 return (is_valid_type(&method_sig[index], len - index) == (len - index));
636 }
637 }
638 return false;
639 }
640
641 bool SignatureVerifier::is_valid_type_signature(const Symbol* sig) {
642 const char* type_sig = (const char*)sig->bytes();
643 ssize_t len = sig->utf8_length();
644 return (type_sig != nullptr && len >= 1 &&
645 (is_valid_type(type_sig, len) == len));
646 }
647
648 // Checks to see if the type (not to go beyond 'limit') refers to a valid type.
649 // Returns -1 if it is not, or the index of the next character that is not part
650 // of the type. The type encoding may end before 'limit' and that's ok.
651 ssize_t SignatureVerifier::is_valid_type(const char* type, ssize_t limit) {
652 ssize_t index = 0;
653
654 // Iterate over any number of array dimensions
655 while (index < limit && type[index] == JVM_SIGNATURE_ARRAY) ++index;
656 if (index >= limit) {
657 return -1;
658 }
659 switch (type[index]) {
660 case JVM_SIGNATURE_BYTE:
661 case JVM_SIGNATURE_CHAR:
662 case JVM_SIGNATURE_FLOAT:
663 case JVM_SIGNATURE_DOUBLE:
664 case JVM_SIGNATURE_INT:
665 case JVM_SIGNATURE_LONG:
666 case JVM_SIGNATURE_SHORT:
667 case JVM_SIGNATURE_BOOLEAN:
668 case JVM_SIGNATURE_VOID:
669 return index + 1;
670 case JVM_SIGNATURE_CLASS:
671 for (index = index + 1; index < limit; ++index) {
672 char c = type[index];
673 switch (c) {
674 case JVM_SIGNATURE_ENDCLASS:
675 return index + 1;
676 case '\0': case JVM_SIGNATURE_DOT: case JVM_SIGNATURE_ARRAY:
677 return -1;
678 default: ; // fall through
679 }
680 }
681 // fall through
682 default: ; // fall through
683 }
684 return -1;
685 }
686
687 #endif // ASSERT
688
689 // Adds an argument to the signature
690 void SigEntry::add_entry(GrowableArray<SigEntry>* sig, BasicType bt, Symbol* symbol, int offset) {
691 sig->append(SigEntry(bt, offset, symbol));
692 if (bt == T_LONG || bt == T_DOUBLE) {
693 sig->append(SigEntry(T_VOID, offset, symbol)); // Longs and doubles take two stack slots
694 }
695 }
696
697 // Returns true if the argument at index 'i' is not an inline type delimiter
698 bool SigEntry::skip_value_delimiters(const GrowableArray<SigEntry>* sig, int i) {
699 return (sig->at(i)._bt != T_METADATA &&
700 (sig->at(i)._bt != T_VOID || sig->at(i-1)._bt == T_LONG || sig->at(i-1)._bt == T_DOUBLE));
701 }
702
703 // Fill basic type array from signature array
704 int SigEntry::fill_sig_bt(const GrowableArray<SigEntry>* sig, BasicType* sig_bt) {
705 int count = 0;
706 for (int i = 0; i < sig->length(); i++) {
707 if (skip_value_delimiters(sig, i)) {
708 sig_bt[count++] = sig->at(i)._bt;
709 }
710 }
711 return count;
712 }
713
714 // Create a temporary symbol from the signature array
715 TempNewSymbol SigEntry::create_symbol(const GrowableArray<SigEntry>* sig) {
716 ResourceMark rm;
717 int length = sig->length();
718 char* sig_str = NEW_RESOURCE_ARRAY(char, 2*length + 3);
719 int idx = 0;
720 sig_str[idx++] = '(';
721 for (int i = 0; i < length; i++) {
722 BasicType bt = sig->at(i)._bt;
723 if (bt == T_METADATA || bt == T_VOID) {
724 // Ignore
725 } else {
726 if (bt == T_ARRAY) {
727 bt = T_OBJECT; // We don't know the element type, treat as Object
728 }
729 sig_str[idx++] = type2char(bt);
730 if (bt == T_OBJECT) {
731 sig_str[idx++] = ';';
732 }
733 }
734 }
735 sig_str[idx++] = ')';
736 // Add a dummy return type. It won't be used but SignatureStream needs it.
737 sig_str[idx++] = 'V';
738 sig_str[idx++] = '\0';
739 return SymbolTable::new_symbol(sig_str);
740 }