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src/hotspot/share/runtime/signature.cpp

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 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 "runtime/fieldDescriptor.inline.hpp"
 39 #include "runtime/handles.inline.hpp"

 40 #include "runtime/safepointVerifiers.hpp"
 41 #include "runtime/sharedRuntime.hpp"
 42 #include "runtime/signature.hpp"
 43 #include "runtime/sharedRuntime.hpp"
 44 
 45 // Implementation of SignatureIterator
 46 
 47 // Signature syntax:
 48 //
 49 // Signature  = "(" {Parameter} ")" ReturnType.
 50 // Parameter  = FieldType.
 51 // ReturnType = FieldType | "V".
 52 // FieldType  = "B" | "C" | "D" | "F" | "I" | "J" | "S" | "Z" | "L" ClassName ";" | "[" FieldType.
 53 // ClassName  = string.
 54 
 55 // The ClassName string can be any JVM-style UTF8 string except:
 56 //  - an empty string (the empty string is never a name of any kind)
 57 //  - a string which begins or ends with slash '/' (the package separator)
 58 //  - a string which contains adjacent slashes '//' (no empty package names)
 59 //  - a string which contains a semicolon ';' (the end-delimiter)
 60 //  - a string which contains a left bracket '[' (the array marker)
 61 //  - a string which contains a dot '.' (the external package separator)
 62 //
 63 // Other "meta-looking" characters, such as '(' and '<' and '+',
 64 // are perfectly legitimate within a class name, for the JVM.
 65 // Class names which contain double slashes ('a//b') and non-initial
 66 // brackets ('a[b]') are reserved for possible enrichment of the
 67 // type language.
 68 
 69 void SignatureIterator::set_fingerprint(fingerprint_t fingerprint) {
 70   if (!fp_is_valid(fingerprint)) {
 71     _fingerprint = fingerprint;
 72     _return_type = T_ILLEGAL;

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 defined(PPC64) || defined(S390)
239     if (_int_args < Argument::n_int_register_parameters_j) {
240       _int_args++;
241     } else {
242       _stack_arg_slots += 1;
243     }
244     break;
245 #endif // defined(PPC64) || defined(S390)
246   case T_LONG:
247   case T_OBJECT:
248   case T_ARRAY:
249   case T_ADDRESS:

250     if (_int_args < Argument::n_int_register_parameters_j) {
251       _int_args++;
252     } else {
253       PPC64_ONLY(_stack_arg_slots = align_up(_stack_arg_slots, 2));
254       S390_ONLY(_stack_arg_slots = align_up(_stack_arg_slots, 2));
255       _stack_arg_slots += 2;
256     }
257     break;
258   case T_FLOAT:
259 #if defined(PPC64) || defined(S390)
260     if (_fp_args < Argument::n_float_register_parameters_j) {
261       _fp_args++;
262     } else {
263       _stack_arg_slots += 1;
264     }
265     break;
266 #endif // defined(PPC64) || defined(S390)
267   case T_DOUBLE:
268     if (_fp_args < Argument::n_float_register_parameters_j) {
269       _fp_args++;

316     assert(_names == nullptr, "_names unexpectedly created");
317     return;
318   }
319 
320   // decrement refcount for names created during signature parsing
321   _previous_name->decrement_refcount();
322   if (_names != nullptr) {
323     for (int i = 0; i < _names->length(); i++) {
324       _names->at(i)->decrement_refcount();
325     }
326   }
327 }
328 
329 inline int SignatureStream::scan_type(BasicType type) {
330   const u1* base = _signature->bytes();
331   int end = _end;
332   int limit = _limit;
333   const u1* tem;
334   switch (type) {
335   case T_OBJECT:

336     tem = (const u1*) memchr(&base[end], JVM_SIGNATURE_ENDCLASS, limit - end);
337     return (tem == nullptr ? limit : pointer_delta_as_int(tem + 1, base));
338 
339   case T_ARRAY:
340     while ((end < limit) && ((char)base[end] == JVM_SIGNATURE_ARRAY)) { end++; }
341     // If we discovered only the string of '[', this means something is wrong.
342     if (end >= limit) {
343       assert(false, "Invalid type detected");
344       return limit;
345     }
346     _array_prefix = end - _end;  // number of '[' chars just skipped
347     if (Signature::has_envelope(base[end])) {
348       tem = (const u1 *) memchr(&base[end], JVM_SIGNATURE_ENDCLASS, limit - end);
349       return (tem == nullptr ? limit : pointer_delta_as_int(tem + 1, base));
350     }
351     // Skipping over a single character for a primitive type.
352     assert(is_java_primitive(decode_signature_char(base[end])), "only primitives expected");
353     return end + 1;
354 
355   default:

400   assert(sig->char_at(0) == JVM_SIGNATURE_ARRAY, "this should already have been checked");
401   // The first character is already checked
402   int i = 1;
403   int len = sig->utf8_length();
404   // First skip all '['s
405   while(i < len - 1 && sig->char_at(i) == JVM_SIGNATURE_ARRAY) i++;
406 
407   // Check type
408   switch(sig->char_at(i)) {
409   case JVM_SIGNATURE_BYTE:
410   case JVM_SIGNATURE_CHAR:
411   case JVM_SIGNATURE_DOUBLE:
412   case JVM_SIGNATURE_FLOAT:
413   case JVM_SIGNATURE_INT:
414   case JVM_SIGNATURE_LONG:
415   case JVM_SIGNATURE_SHORT:
416   case JVM_SIGNATURE_BOOLEAN:
417     // If it is an array, the type is the last character
418     return (i + 1 == len);
419   case JVM_SIGNATURE_CLASS:

420     // If it is an object, the last character must be a ';'
421     return sig->char_at(len - 1) == JVM_SIGNATURE_ENDCLASS;
422   }
423   return false;
424 }
425 
426 BasicType Signature::basic_type(int ch) {
427   BasicType btcode = decode_signature_char(ch);
428   if (btcode == 0)  return T_ILLEGAL;
429   return btcode;
430 }
431 
432 Symbol* Signature::strip_envelope(const Symbol* signature) {
433   assert(has_envelope(signature), "precondition");
434   return SymbolTable::new_symbol((char*) signature->bytes() + 1,
435                                  signature->utf8_length() - 2);
436 }
437 
438 static const int jl_len = 10, object_len = 6, jl_object_len = jl_len + object_len;
439 static const char jl_str[] = "java/lang/";

481   if (name->equals(symbol_chars, len)) {
482     return name;
483   }
484 
485   // Save names for cleaning up reference count at the end of
486   // SignatureStream scope.
487   name = SymbolTable::new_symbol(symbol_chars, len);
488 
489   // Only allocate the GrowableArray for the _names buffer if more than
490   // one name is being processed in the signature.
491   if (!_previous_name->is_permanent()) {
492     if (_names == nullptr) {
493       _names = new GrowableArray<Symbol*>(10);
494     }
495     _names->push(_previous_name);
496   }
497   _previous_name = name;
498   return name;
499 }
500 















501 Klass* SignatureStream::as_klass(Handle class_loader, Handle protection_domain,
502                                  FailureMode failure_mode, TRAPS) {
503   if (!is_reference()) {
504     return nullptr;
505   }
506   Symbol* name = as_symbol();
507   Klass* k = nullptr;
508   if (failure_mode == ReturnNull) {
509     // Note:  SD::resolve_or_null returns null for most failure modes,
510     // but not all.  Circularity errors, invalid PDs, etc., throw.
511     k = SystemDictionary::resolve_or_null(name, class_loader, protection_domain, CHECK_NULL);
512   } else if (failure_mode == CachedOrNull) {
513     NoSafepointVerifier nsv;  // no loading, now, we mean it!
514     assert(!HAS_PENDING_EXCEPTION, "");
515     k = SystemDictionary::find_instance_klass(THREAD, name, class_loader, protection_domain);
516     // SD::find does not trigger loading, so there should be no throws
517     // Still, bad things can happen, so we CHECK_NULL and ask callers
518     // to do likewise.
519     return k;
520   } else {
521     // The only remaining failure mode is NCDFError.
522     // The test here allows for an additional mode CNFException
523     // if callers need to request the reflective error instead.
524     bool throw_error = (failure_mode == NCDFError);
525     k = SystemDictionary::resolve_or_fail(name, class_loader, protection_domain, throw_error, CHECK_NULL);
526   }
527 
528   return k;
529 }
530 
531 oop SignatureStream::as_java_mirror(Handle class_loader, Handle protection_domain,
532                                     FailureMode failure_mode, TRAPS) {
533   if (!is_reference()) {
534     return Universe::java_mirror(type());
535   }
536   Klass* klass = as_klass(class_loader, protection_domain, failure_mode, CHECK_NULL);
537   if (klass == nullptr) {
538     return nullptr;
539   }
540   return klass->java_mirror();

541 }
542 
543 void SignatureStream::skip_to_return_type() {
544   while (!at_return_type()) {
545     next();
546   }
547 }
548 
549 ResolvingSignatureStream::ResolvingSignatureStream(Symbol* signature,
550                                                    Handle class_loader,
551                                                    Handle protection_domain,
552                                                    bool is_method)
553   : SignatureStream(signature, is_method),
554     _class_loader(class_loader), _protection_domain(protection_domain)
555 {
556   initialize_load_origin(nullptr);
557 }
558 
559 ResolvingSignatureStream::ResolvingSignatureStream(Symbol* signature, Klass* load_origin, bool is_method)
560   : SignatureStream(signature, is_method)
561 {
562   assert(load_origin != nullptr, "");
563   initialize_load_origin(load_origin);
564 }
565 
566 ResolvingSignatureStream::ResolvingSignatureStream(const Method* method)
567   : SignatureStream(method->signature(), true)
568 {
569   initialize_load_origin(method->method_holder());
570 }
571 
572 void ResolvingSignatureStream::cache_handles() {
573   assert(_load_origin != nullptr, "");
574   JavaThread* current = JavaThread::current();
575   _class_loader = Handle(current, _load_origin->class_loader());
576   _protection_domain = Handle(current, _load_origin->protection_domain());
577 }
578 
579 #ifdef ASSERT
580 
581 extern bool signature_constants_sane(); // called from basic_types_init()
582 
583 bool signature_constants_sane() {
584   // for the lookup table, test every 8-bit code point, and then some:
585   for (int i = -256; i <= 256; i++) {
586     int btcode = 0;
587     switch (i) {
588 #define EACH_SIG(ch, bt, ignore) \
589     case ch: { btcode = bt; break; }
590     SIGNATURE_TYPES_DO(EACH_SIG, ignore)
591 #undef EACH_SIG
592     }
593     int btc = decode_signature_char(i);
594     assert(btc == btcode, "misconfigured table: %d => %d not %d", i, btc, btcode);
595   }
596   return true;
597 }
598 
599 bool SignatureVerifier::is_valid_method_signature(Symbol* sig) {
600   const char* method_sig = (const char*)sig->bytes();
601   ssize_t len = sig->utf8_length();
602   ssize_t index = 0;
603   if (method_sig != nullptr && len > 1 && method_sig[index] == JVM_SIGNATURE_FUNC) {
604     ++index;
605     while (index < len && method_sig[index] != JVM_SIGNATURE_ENDFUNC) {
606       ssize_t res = is_valid_type(&method_sig[index], len - index);
607       if (res == -1) {
608         return false;
609       } else {
610         index += res;
611       }
612     }
613     if (index < len && method_sig[index] == JVM_SIGNATURE_ENDFUNC) {
614       // check the return type
615       ++index;
616       return (is_valid_type(&method_sig[index], len - index) == (len - index));
617     }
618   }
619   return false;
620 }
621 
622 bool SignatureVerifier::is_valid_type_signature(Symbol* sig) {
623   const char* type_sig = (const char*)sig->bytes();
624   ssize_t len = sig->utf8_length();
625   return (type_sig != nullptr && len >= 1 &&
626           (is_valid_type(type_sig, len) == len));
627 }
628 
629 // Checks to see if the type (not to go beyond 'limit') refers to a valid type.
630 // Returns -1 if it is not, or the index of the next character that is not part
631 // of the type.  The type encoding may end before 'limit' and that's ok.
632 ssize_t SignatureVerifier::is_valid_type(const char* type, ssize_t limit) {
633   ssize_t index = 0;
634 
635   // Iterate over any number of array dimensions
636   while (index < limit && type[index] == JVM_SIGNATURE_ARRAY) ++index;
637   if (index >= limit) {
638     return -1;
639   }
640   switch (type[index]) {
641     case JVM_SIGNATURE_BYTE:
642     case JVM_SIGNATURE_CHAR:
643     case JVM_SIGNATURE_FLOAT:
644     case JVM_SIGNATURE_DOUBLE:
645     case JVM_SIGNATURE_INT:
646     case JVM_SIGNATURE_LONG:
647     case JVM_SIGNATURE_SHORT:
648     case JVM_SIGNATURE_BOOLEAN:
649     case JVM_SIGNATURE_VOID:
650       return index + 1;

651     case JVM_SIGNATURE_CLASS:
652       for (index = index + 1; index < limit; ++index) {
653         char c = type[index];
654         switch (c) {
655           case JVM_SIGNATURE_ENDCLASS:
656             return index + 1;
657           case '\0': case JVM_SIGNATURE_DOT: case JVM_SIGNATURE_ARRAY:
658             return -1;
659           default: ; // fall through
660         }
661       }
662       // fall through
663     default: ; // fall through
664   }
665   return -1;
666 }
667 
668 #endif // ASSERT






















































 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;

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++;

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:

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/";

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 }
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