1 /*
2 * Copyright (c) 1997, 2024, 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 "asm/assembler.hpp"
26 #include "classfile/symbolTable.hpp"
27 #include "classfile/systemDictionary.hpp"
28 #include "classfile/vmSymbols.hpp"
29 #include "memory/oopFactory.hpp"
30 #include "memory/resourceArea.hpp"
31 #include "memory/universe.hpp"
32 #include "oops/instanceKlass.hpp"
33 #include "oops/klass.inline.hpp"
34 #include "oops/oop.inline.hpp"
35 #include "oops/symbol.hpp"
36 #include "oops/typeArrayKlass.hpp"
37 #include "oops/inlineKlass.inline.hpp"
38 #include "runtime/fieldDescriptor.inline.hpp"
39 #include "runtime/handles.inline.hpp"
40 #include "runtime/interfaceSupport.inline.hpp"
41 #include "runtime/safepointVerifiers.hpp"
42 #include "runtime/sharedRuntime.hpp"
43 #include "runtime/signature.hpp"
44 #include "runtime/sharedRuntime.hpp"
45
46 // Implementation of SignatureIterator
47
48 // Signature syntax:
49 //
50 // Signature = "(" {Parameter} ")" ReturnType.
51 // Parameter = FieldType.
52 // ReturnType = FieldType | "V".
53 // FieldType = "B" | "C" | "D" | "F" | "I" | "J" | "S" | "Z" | "L" ClassName ";" | "Q" ValueClassName ";" | "[" FieldType.
54 // ClassName = string.
55
56 // The ClassName string can be any JVM-style UTF8 string except:
57 // - an empty string (the empty string is never a name of any kind)
58 // - a string which begins or ends with slash '/' (the package separator)
59 // - a string which contains adjacent slashes '//' (no empty package names)
60 // - a string which contains a semicolon ';' (the end-delimiter)
61 // - a string which contains a left bracket '[' (the array marker)
62 // - a string which contains a dot '.' (the external package separator)
63 //
64 // Other "meta-looking" characters, such as '(' and '<' and '+',
65 // are perfectly legitimate within a class name, for the JVM.
66 // Class names which contain double slashes ('a//b') and non-initial
67 // brackets ('a[b]') are reserved for possible enrichment of the
68 // type language.
69
70 void SignatureIterator::set_fingerprint(fingerprint_t fingerprint) {
71 if (!fp_is_valid(fingerprint)) {
72 _fingerprint = fingerprint;
73 _return_type = T_ILLEGAL;
74 } else if (fingerprint != _fingerprint) {
75 assert(_fingerprint == zero_fingerprint(), "consistent fingerprint values");
76 _fingerprint = fingerprint;
77 _return_type = fp_return_type(fingerprint);
78 }
79 }
80
81 BasicType SignatureIterator::return_type() {
82 if (_return_type == T_ILLEGAL) {
83 SignatureStream ss(_signature);
84 ss.skip_to_return_type();
85 _return_type = ss.type();
86 assert(_return_type != T_ILLEGAL, "illegal return type");
87 }
88 return _return_type;
89 }
90
91 bool SignatureIterator::fp_is_valid_type(BasicType type, bool for_return_type) {
92 assert(type != (BasicType)fp_parameters_done, "fingerprint is incorrectly at done");
93 assert(((int)type & ~fp_parameter_feature_mask) == 0, "fingerprint feature mask yielded non-zero value");
94 return (is_java_primitive(type) ||
95 is_reference_type(type) ||
96 (for_return_type && type == T_VOID));
97 }
98
99 ArgumentSizeComputer::ArgumentSizeComputer(Symbol* signature)
100 : SignatureIterator(signature)
101 {
102 _size = 0;
103 do_parameters_on(this); // non-virtual template execution
104 }
105
106 ArgumentCount::ArgumentCount(Symbol* signature)
107 : SignatureIterator(signature)
108 {
109 _size = 0;
110 do_parameters_on(this); // non-virtual template execution
111 }
112
113 ReferenceArgumentCount::ReferenceArgumentCount(Symbol* signature)
114 : SignatureIterator(signature)
115 {
116 _refs = 0;
117 do_parameters_on(this); // non-virtual template execution
118 }
119
120 #if !defined(_LP64) || defined(ZERO) || defined(ASSERT)
121 static int compute_num_stack_arg_slots(Symbol* signature, int sizeargs, bool is_static) {
122 ResourceMark rm;
123 BasicType* sig_bt = NEW_RESOURCE_ARRAY(BasicType, sizeargs);
124 VMRegPair* regs = NEW_RESOURCE_ARRAY(VMRegPair, sizeargs);
125
126 int sig_index = 0;
127 if (!is_static) {
128 sig_bt[sig_index++] = T_OBJECT; // 'this'
129 }
130 for (SignatureStream ss(signature); !ss.at_return_type(); ss.next()) {
131 BasicType t = ss.type();
132 assert(type2size[t] == 1 || type2size[t] == 2, "size is 1 or 2");
133 sig_bt[sig_index++] = t;
134 if (type2size[t] == 2) {
135 sig_bt[sig_index++] = T_VOID;
136 }
137 }
138 assert(sig_index == sizeargs, "sig_index: %d sizeargs: %d", sig_index, sizeargs);
139
140 return SharedRuntime::java_calling_convention(sig_bt, regs, sizeargs);
141 }
142 #endif
143
144 void Fingerprinter::compute_fingerprint_and_return_type(bool static_flag) {
145 // See if we fingerprinted this method already
146 if (_method != nullptr) {
147 assert(!static_flag, "must not be passed by caller");
148 static_flag = _method->is_static();
149 _fingerprint = _method->constMethod()->fingerprint();
150
151 if (_fingerprint != zero_fingerprint()) {
152 _return_type = _method->result_type();
153 assert(is_java_type(_return_type), "return type must be a java type");
154 return;
155 }
156
157 if (_method->size_of_parameters() > fp_max_size_of_parameters) {
158 _fingerprint = overflow_fingerprint();
159 _method->constMethod()->set_fingerprint(_fingerprint);
160 // as long as we are here compute the return type:
161 _return_type = ResultTypeFinder(_method->signature()).type();
162 assert(is_java_type(_return_type), "return type must be a java type");
163 return;
164 }
165 }
166
167 // Note: This will always take the slow path, since _fp==zero_fp.
168 initialize_accumulator();
169 initialize_calling_convention(static_flag);
170 do_parameters_on(this);
171 assert(fp_is_valid_type(_return_type, true), "bad result type");
172
173 // Fill in the return type and static bits:
174 _accumulator |= _return_type << fp_static_feature_size;
175 if (static_flag) {
176 _accumulator |= fp_is_static_bit;
177 } else {
178 _param_size += 1; // this is the convention for Method::compute_size_of_parameters
179 }
180
181 #if defined(_LP64) && !defined(ZERO)
182 #ifdef ASSERT
183 int dbg_stack_arg_slots = compute_num_stack_arg_slots(_signature, _param_size, static_flag);
184 assert(_stack_arg_slots == dbg_stack_arg_slots, "fingerprinter: %d full: %d", _stack_arg_slots, dbg_stack_arg_slots);
185 #endif
186 #else
187 // Fallback: computed _stack_arg_slots is unreliable, compute directly.
188 _stack_arg_slots = compute_num_stack_arg_slots(_signature, _param_size, static_flag);
189 #endif
190
191 // Detect overflow. (We counted _param_size correctly.)
192 if (_method == nullptr && _param_size > fp_max_size_of_parameters) {
193 // We did a one-pass computation of argument size, return type,
194 // and fingerprint.
195 _fingerprint = overflow_fingerprint();
196 return;
197 }
198
199 assert(_shift_count < BitsPerLong,
200 "shift count overflow %d (%d vs. %d): %s",
201 _shift_count, _param_size, fp_max_size_of_parameters,
202 _signature->as_C_string());
203 assert((_accumulator >> _shift_count) == fp_parameters_done, "must be zero");
204
205 // This is the result, along with _return_type:
206 _fingerprint = _accumulator;
207
208 // Cache the result on the method itself:
209 if (_method != nullptr) {
210 _method->constMethod()->set_fingerprint(_fingerprint);
211 }
212 }
213
214 void Fingerprinter::initialize_calling_convention(bool static_flag) {
215 _int_args = 0;
216 _fp_args = 0;
217
218 if (!static_flag) { // `this` takes up an int register
219 _int_args++;
220 }
221 }
222
223 void Fingerprinter::do_type_calling_convention(BasicType type) {
224 // We compute the number of slots for stack-passed arguments in compiled calls.
225 // TODO: SharedRuntime::java_calling_convention is the shared code that knows all details
226 // about the platform-specific calling conventions. This method tries to compute the stack
227 // args number... poorly, at least for 32-bit ports and for zero. Current code has the fallback
228 // that recomputes the stack args number from SharedRuntime::java_calling_convention.
229 #if defined(_LP64) && !defined(ZERO)
230 switch (type) {
231 case T_VOID:
232 break;
233 case T_BOOLEAN:
234 case T_CHAR:
235 case T_BYTE:
236 case T_SHORT:
237 case T_INT:
238 if (_int_args < Argument::n_int_register_parameters_j) {
239 _int_args++;
240 } else {
241 #if defined(PPC64) || defined(S390)
242 _stack_arg_slots += 1;
243 #else
244 _stack_arg_slots = align_up(_stack_arg_slots, 2);
245 _stack_arg_slots += 1;
246 #endif // defined(PPC64) || defined(S390)
247 }
248 break;
249 case T_LONG:
250 case T_OBJECT:
251 case T_ARRAY:
252 case T_ADDRESS:
253 if (_int_args < Argument::n_int_register_parameters_j) {
254 _int_args++;
255 } else {
256 _stack_arg_slots = align_up(_stack_arg_slots, 2);
257 _stack_arg_slots += 2;
258 }
259 break;
260 case T_FLOAT:
261 if (_fp_args < Argument::n_float_register_parameters_j) {
262 _fp_args++;
263 } else {
264 #if defined(PPC64) || defined(S390)
265 _stack_arg_slots += 1;
266 #else
267 _stack_arg_slots = align_up(_stack_arg_slots, 2);
268 _stack_arg_slots += 1;
269 #endif // defined(PPC64) || defined(S390)
270 }
271 break;
272 case T_DOUBLE:
273 if (_fp_args < Argument::n_float_register_parameters_j) {
274 _fp_args++;
275 } else {
276 _stack_arg_slots = align_up(_stack_arg_slots, 2);
277 _stack_arg_slots += 2;
278 }
279 break;
280 default:
281 ShouldNotReachHere();
282 break;
283 }
284 #endif
285 }
286
287 // Implementation of SignatureStream
288
289 static inline BasicType decode_signature_char(int ch) {
290 switch (ch) {
291 #define EACH_SIG(ch, bt, ignore) \
292 case ch: return bt;
293 SIGNATURE_TYPES_DO(EACH_SIG, ignore)
294 #undef EACH_SIG
295 }
296 return (BasicType)0;
297 }
298
299 SignatureStream::SignatureStream(const Symbol* signature,
300 bool is_method) {
301 assert(!is_method || signature->starts_with(JVM_SIGNATURE_FUNC),
302 "method signature required");
303 _signature = signature;
304 _limit = signature->utf8_length();
305 int oz = (is_method ? _s_method : _s_field);
306 _state = oz;
307 _begin = _end = oz; // skip first '(' in method signatures
308 _array_prefix = 0; // just for definiteness
309
310 // assigning java/lang/Object to _previous_name means we can
311 // avoid a number of null checks in the parser
312 _previous_name = vmSymbols::java_lang_Object();
313 _names = nullptr;
314 next();
315 }
316
317 SignatureStream::~SignatureStream() {
318 if (_previous_name == vmSymbols::java_lang_Object()) {
319 // no names were created
320 assert(_names == nullptr, "_names unexpectedly created");
321 return;
322 }
323
324 // decrement refcount for names created during signature parsing
325 _previous_name->decrement_refcount();
326 if (_names != nullptr) {
327 for (int i = 0; i < _names->length(); i++) {
328 _names->at(i)->decrement_refcount();
329 }
330 }
331 }
332
333 inline int SignatureStream::scan_type(BasicType type) {
334 const u1* base = _signature->bytes();
335 int end = _end;
336 int limit = _limit;
337 const u1* tem;
338 switch (type) {
339 case T_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 // If it is an object, the last character must be a ';'
425 return sig->char_at(len - 1) == JVM_SIGNATURE_ENDCLASS;
426 }
427 return false;
428 }
429
430 BasicType Signature::basic_type(int ch) {
431 BasicType btcode = decode_signature_char(ch);
432 if (btcode == 0) return T_ILLEGAL;
433 return btcode;
434 }
435
436 Symbol* Signature::strip_envelope(const Symbol* signature) {
437 assert(has_envelope(signature), "precondition");
438 return SymbolTable::new_symbol((char*) signature->bytes() + 1,
439 signature->utf8_length() - 2);
440 }
441
442 static const int jl_len = 10, object_len = 6, jl_object_len = jl_len + object_len;
443 static const char jl_str[] = "java/lang/";
444
445 #ifdef ASSERT
446 static bool signature_symbols_sane() {
447 static bool done;
448 if (done) return true;
449 done = true;
450 // test some tense code that looks for common symbol names:
451 assert(vmSymbols::java_lang_Object()->utf8_length() == jl_object_len &&
452 vmSymbols::java_lang_Object()->starts_with(jl_str, jl_len) &&
453 vmSymbols::java_lang_Object()->ends_with("Object", object_len) &&
454 vmSymbols::java_lang_Object()->is_permanent() &&
455 vmSymbols::java_lang_String()->utf8_length() == jl_object_len &&
456 vmSymbols::java_lang_String()->starts_with(jl_str, jl_len) &&
457 vmSymbols::java_lang_String()->ends_with("String", object_len) &&
458 vmSymbols::java_lang_String()->is_permanent(),
459 "sanity");
460 return true;
461 }
462 #endif //ASSERT
463
464 // returns a symbol; the caller is responsible for decrementing it
465 Symbol* SignatureStream::find_symbol() {
466 // Create a symbol from for string _begin _end
467 int begin = raw_symbol_begin();
468 int end = raw_symbol_end();
469
470 const char* symbol_chars = (const char*)_signature->base() + begin;
471 int len = end - begin;
472
473 // Quick check for common symbols in signatures
474 assert(signature_symbols_sane(), "incorrect signature sanity check");
475 if (len == jl_object_len &&
476 memcmp(symbol_chars, jl_str, jl_len) == 0) {
477 if (memcmp("String", symbol_chars + jl_len, object_len) == 0) {
478 return vmSymbols::java_lang_String();
479 } else if (memcmp("Object", symbol_chars + jl_len, object_len) == 0) {
480 return vmSymbols::java_lang_Object();
481 }
482 }
483
484 Symbol* name = _previous_name;
485 if (name->equals(symbol_chars, len)) {
486 return name;
487 }
488
489 // Save names for cleaning up reference count at the end of
490 // SignatureStream scope.
491 name = SymbolTable::new_symbol(symbol_chars, len);
492
493 // Only allocate the GrowableArray for the _names buffer if more than
494 // one name is being processed in the signature.
495 if (!_previous_name->is_permanent()) {
496 if (_names == nullptr) {
497 _names = new GrowableArray<Symbol*>(10);
498 }
499 _names->push(_previous_name);
500 }
501 _previous_name = name;
502 return name;
503 }
504
505 InlineKlass* SignatureStream::as_inline_klass(InstanceKlass* holder) {
506 ThreadInVMfromUnknown tiv;
507 JavaThread* THREAD = JavaThread::current();
508 HandleMark hm(THREAD);
509 Handle class_loader(THREAD, holder->class_loader());
510 Klass* k = as_klass(class_loader, SignatureStream::CachedOrNull, THREAD);
511 assert(!HAS_PENDING_EXCEPTION, "Should never throw");
512 if (k != nullptr && k->is_inline_klass()) {
513 return InlineKlass::cast(k);
514 } else {
515 return nullptr;
516 }
517 }
518
519 Klass* SignatureStream::as_klass(Handle class_loader, FailureMode failure_mode, TRAPS) {
520 if (!is_reference()) {
521 return nullptr;
522 }
523 Symbol* name = as_symbol();
524 Klass* k = nullptr;
525 if (failure_mode == ReturnNull) {
526 // Note: SD::resolve_or_null returns null for most failure modes,
527 // but not all. Circularity errors, invalid PDs, etc., throw.
528 k = SystemDictionary::resolve_or_null(name, class_loader, CHECK_NULL);
529 } else if (failure_mode == CachedOrNull) {
530 NoSafepointVerifier nsv; // no loading, now, we mean it!
531 assert(!HAS_PENDING_EXCEPTION, "");
532 k = SystemDictionary::find_instance_klass(THREAD, name, class_loader);
533 // SD::find does not trigger loading, so there should be no throws
534 // Still, bad things can happen, so we CHECK_NULL and ask callers
535 // to do likewise.
536 return k;
537 } else {
538 // The only remaining failure mode is NCDFError.
539 // The test here allows for an additional mode CNFException
540 // if callers need to request the reflective error instead.
541 bool throw_error = (failure_mode == NCDFError);
542 k = SystemDictionary::resolve_or_fail(name, class_loader, throw_error, CHECK_NULL);
543 }
544
545 return k;
546 }
547
548 oop SignatureStream::as_java_mirror(Handle class_loader, FailureMode failure_mode, TRAPS) {
549 if (!is_reference()) {
550 return Universe::java_mirror(type());
551 }
552 Klass* klass = as_klass(class_loader, failure_mode, CHECK_NULL);
553 if (klass == nullptr) {
554 return nullptr;
555 }
556 return klass->java_mirror();
557 }
558
559 void SignatureStream::skip_to_return_type() {
560 while (!at_return_type()) {
561 next();
562 }
563 }
564
565 ResolvingSignatureStream::ResolvingSignatureStream(Symbol* signature,
566 Handle class_loader,
567 bool is_method)
568 : SignatureStream(signature, is_method), _class_loader(class_loader)
569 {
570 initialize_load_origin(nullptr);
571 }
572
573 ResolvingSignatureStream::ResolvingSignatureStream(Symbol* signature, Klass* load_origin, bool is_method)
574 : SignatureStream(signature, is_method)
575 {
576 assert(load_origin != nullptr, "");
577 initialize_load_origin(load_origin);
578 }
579
580 ResolvingSignatureStream::ResolvingSignatureStream(const Method* method)
581 : SignatureStream(method->signature(), true)
582 {
583 initialize_load_origin(method->method_holder());
584 }
585
586 void ResolvingSignatureStream::cache_handles() {
587 assert(_load_origin != nullptr, "");
588 JavaThread* current = JavaThread::current();
589 _class_loader = Handle(current, _load_origin->class_loader());
590 }
591
592 #ifdef ASSERT
593 extern bool signature_constants_sane(); // called from basic_types_init()
594
595 bool signature_constants_sane() {
596 // for the lookup table, test every 8-bit code point, and then some:
597 for (int i = -256; i <= 256; i++) {
598 int btcode = 0;
599 switch (i) {
600 #define EACH_SIG(ch, bt, ignore) \
601 case ch: { btcode = bt; break; }
602 SIGNATURE_TYPES_DO(EACH_SIG, ignore)
603 #undef EACH_SIG
604 }
605 int btc = decode_signature_char(i);
606 assert(btc == btcode, "misconfigured table: %d => %d not %d", i, btc, btcode);
607 }
608 return true;
609 }
610
611 bool SignatureVerifier::is_valid_method_signature(const Symbol* sig) {
612 const char* method_sig = (const char*)sig->bytes();
613 ssize_t len = sig->utf8_length();
614 ssize_t index = 0;
615 if (method_sig != nullptr && len > 1 && method_sig[index] == JVM_SIGNATURE_FUNC) {
616 ++index;
617 while (index < len && method_sig[index] != JVM_SIGNATURE_ENDFUNC) {
618 ssize_t res = is_valid_type(&method_sig[index], len - index);
619 if (res == -1) {
620 return false;
621 } else {
622 index += res;
623 }
624 }
625 if (index < len && method_sig[index] == JVM_SIGNATURE_ENDFUNC) {
626 // check the return type
627 ++index;
628 return (is_valid_type(&method_sig[index], len - index) == (len - index));
629 }
630 }
631 return false;
632 }
633
634 bool SignatureVerifier::is_valid_type_signature(const Symbol* sig) {
635 const char* type_sig = (const char*)sig->bytes();
636 ssize_t len = sig->utf8_length();
637 return (type_sig != nullptr && len >= 1 &&
638 (is_valid_type(type_sig, len) == len));
639 }
640
641 // Checks to see if the type (not to go beyond 'limit') refers to a valid type.
642 // Returns -1 if it is not, or the index of the next character that is not part
643 // of the type. The type encoding may end before 'limit' and that's ok.
644 ssize_t SignatureVerifier::is_valid_type(const char* type, ssize_t limit) {
645 ssize_t index = 0;
646
647 // Iterate over any number of array dimensions
648 while (index < limit && type[index] == JVM_SIGNATURE_ARRAY) ++index;
649 if (index >= limit) {
650 return -1;
651 }
652 switch (type[index]) {
653 case JVM_SIGNATURE_BYTE:
654 case JVM_SIGNATURE_CHAR:
655 case JVM_SIGNATURE_FLOAT:
656 case JVM_SIGNATURE_DOUBLE:
657 case JVM_SIGNATURE_INT:
658 case JVM_SIGNATURE_LONG:
659 case JVM_SIGNATURE_SHORT:
660 case JVM_SIGNATURE_BOOLEAN:
661 case JVM_SIGNATURE_VOID:
662 return index + 1;
663 case JVM_SIGNATURE_CLASS:
664 for (index = index + 1; index < limit; ++index) {
665 char c = type[index];
666 switch (c) {
667 case JVM_SIGNATURE_ENDCLASS:
668 return index + 1;
669 case '\0': case JVM_SIGNATURE_DOT: case JVM_SIGNATURE_ARRAY:
670 return -1;
671 default: ; // fall through
672 }
673 }
674 // fall through
675 default: ; // fall through
676 }
677 return -1;
678 }
679
680 #endif // ASSERT
681
682 // Adds an argument to the signature
683 void SigEntry::add_entry(GrowableArray<SigEntry>* sig, BasicType bt, Symbol* symbol, int offset, float sort_offset) {
684 if (sort_offset == -1) {
685 sort_offset = offset;
686 }
687 sig->append(SigEntry(bt, offset, sort_offset, symbol));
688 if (bt == T_LONG || bt == T_DOUBLE) {
689 sig->append(SigEntry(T_VOID, offset, sort_offset, symbol)); // Longs and doubles take two stack slots
690 }
691 }
692
693 // Returns true if the argument at index 'i' is not an inline type delimiter
694 bool SigEntry::skip_value_delimiters(const GrowableArray<SigEntry>* sig, int i) {
695 return (sig->at(i)._bt != T_METADATA &&
696 (sig->at(i)._bt != T_VOID || sig->at(i-1)._bt == T_LONG || sig->at(i-1)._bt == T_DOUBLE));
697 }
698
699 // Fill basic type array from signature array
700 int SigEntry::fill_sig_bt(const GrowableArray<SigEntry>* sig, BasicType* sig_bt) {
701 int count = 0;
702 for (int i = 0; i < sig->length(); i++) {
703 if (skip_value_delimiters(sig, i)) {
704 sig_bt[count++] = sig->at(i)._bt;
705 }
706 }
707 return count;
708 }
709
710 // Create a temporary symbol from the signature array
711 TempNewSymbol SigEntry::create_symbol(const GrowableArray<SigEntry>* sig) {
712 ResourceMark rm;
713 int length = sig->length();
714 char* sig_str = NEW_RESOURCE_ARRAY(char, 2*length + 3);
715 int idx = 0;
716 sig_str[idx++] = '(';
717 for (int i = 0; i < length; i++) {
718 BasicType bt = sig->at(i)._bt;
719 if (bt == T_METADATA || bt == T_VOID) {
720 // Ignore
721 } else {
722 if (bt == T_ARRAY) {
723 bt = T_OBJECT; // We don't know the element type, treat as Object
724 }
725 sig_str[idx++] = type2char(bt);
726 if (bt == T_OBJECT) {
727 sig_str[idx++] = ';';
728 }
729 }
730 }
731 sig_str[idx++] = ')';
732 // Add a dummy return type. It won't be used but SignatureStream needs it.
733 sig_str[idx++] = 'V';
734 sig_str[idx++] = '\0';
735 return SymbolTable::new_symbol(sig_str);
736 }