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src/hotspot/share/runtime/signature.cpp

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

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

483   if (name->equals(symbol_chars, len)) {
484     return name;
485   }
486 
487   // Save names for cleaning up reference count at the end of
488   // SignatureStream scope.
489   name = SymbolTable::new_symbol(symbol_chars, len);
490 
491   // Only allocate the GrowableArray for the _names buffer if more than
492   // one name is being processed in the signature.
493   if (!_previous_name->is_permanent()) {
494     if (_names == nullptr) {
495       _names = new GrowableArray<Symbol*>(10);
496     }
497     _names->push(_previous_name);
498   }
499   _previous_name = name;
500   return name;
501 }
502 














503 Klass* SignatureStream::as_klass(Handle class_loader, FailureMode failure_mode, TRAPS) {
504   if (!is_reference()) {
505     return nullptr;
506   }
507   Symbol* name = as_symbol();
508   Klass* k = nullptr;
509   if (failure_mode == ReturnNull) {
510     // Note:  SD::resolve_or_null returns null for most failure modes,
511     // but not all.  Circularity errors, invalid PDs, etc., throw.
512     k = SystemDictionary::resolve_or_null(name, class_loader, CHECK_NULL);
513   } else if (failure_mode == CachedOrNull) {
514     NoSafepointVerifier nsv;  // no loading, now, we mean it!
515     assert(!HAS_PENDING_EXCEPTION, "");
516     k = SystemDictionary::find_instance_klass(THREAD, name, class_loader);
517     // SD::find does not trigger loading, so there should be no throws
518     // Still, bad things can happen, so we CHECK_NULL and ask callers
519     // to do likewise.
520     return k;
521   } else {
522     // The only remaining failure mode is NCDFError.

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

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

























































 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;

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.

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:

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 }
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