1 // link.cc - Code for linking and resolving classes and pool entries.
3 /* Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007 Free Software Foundation
5 This file is part of libgcj.
7 This software is copyrighted work licensed under the terms of the
8 Libgcj License. Please consult the file "LIBGCJ_LICENSE" for
11 /* Author: Kresten Krab Thorup <krab@gnu.org> */
22 #include <java-interp.h>
24 // Set GC_DEBUG before including gc.h!
25 #ifdef LIBGCJ_GC_DEBUG
34 #include <java-cpool.h>
35 #include <execution.h>
37 #include "jvmti-int.h"
38 #include <java/lang/Class.h>
39 #include <java/lang/String.h>
40 #include <java/lang/StringBuffer.h>
41 #include <java/lang/Thread.h>
42 #include <java/lang/InternalError.h>
43 #include <java/lang/VirtualMachineError.h>
44 #include <java/lang/VerifyError.h>
45 #include <java/lang/NoSuchFieldError.h>
46 #include <java/lang/NoSuchMethodError.h>
47 #include <java/lang/ClassFormatError.h>
48 #include <java/lang/IllegalAccessError.h>
49 #include <java/lang/InternalError.h>
50 #include <java/lang/AbstractMethodError.h>
51 #include <java/lang/NoClassDefFoundError.h>
52 #include <java/lang/IncompatibleClassChangeError.h>
53 #include <java/lang/VerifyError.h>
54 #include <java/lang/VMClassLoader.h>
55 #include <java/lang/reflect/Modifier.h>
56 #include <java/security/CodeSource.h>
67 #define ALIGNOF(TYPE) (offsetof (aligner<TYPE>, field))
69 // This returns the alignment of a type as it would appear in a
70 // structure. This can be different from the alignment of the type
71 // itself. For instance on x86 double is 8-aligned but struct{double}
74 _Jv_Linker::get_alignment_from_class (jclass klass
)
76 if (klass
== JvPrimClass (byte
))
77 return ALIGNOF (jbyte
);
78 else if (klass
== JvPrimClass (short))
79 return ALIGNOF (jshort
);
80 else if (klass
== JvPrimClass (int))
81 return ALIGNOF (jint
);
82 else if (klass
== JvPrimClass (long))
83 return ALIGNOF (jlong
);
84 else if (klass
== JvPrimClass (boolean
))
85 return ALIGNOF (jboolean
);
86 else if (klass
== JvPrimClass (char))
87 return ALIGNOF (jchar
);
88 else if (klass
== JvPrimClass (float))
89 return ALIGNOF (jfloat
);
90 else if (klass
== JvPrimClass (double))
91 return ALIGNOF (jdouble
);
93 return ALIGNOF (jobject
);
97 _Jv_Linker::resolve_field (_Jv_Field
*field
, java::lang::ClassLoader
*loader
)
99 if (! field
->isResolved ())
101 _Jv_Utf8Const
*sig
= (_Jv_Utf8Const
*) field
->type
;
102 jclass type
= _Jv_FindClassFromSignature (sig
->chars(), loader
);
104 throw new java::lang::NoClassDefFoundError(field
->name
->toString());
106 field
->flags
&= ~_Jv_FIELD_UNRESOLVED_FLAG
;
110 // A helper for find_field that knows how to recursively search
111 // superclasses and interfaces.
113 _Jv_Linker::find_field_helper (jclass search
, _Jv_Utf8Const
*name
,
114 _Jv_Utf8Const
*type_name
, jclass type
,
119 // From 5.4.3.2. First search class itself.
120 for (int i
= 0; i
< search
->field_count
; ++i
)
122 _Jv_Field
*field
= &search
->fields
[i
];
123 if (! _Jv_equalUtf8Consts (field
->name
, name
))
126 // Checks for the odd situation where we were able to retrieve the
127 // field's class from signature but the resolution of the field itself
128 // failed which means a different class was resolved.
133 resolve_field (field
, search
->loader
);
135 catch (java::lang::Throwable
*exc
)
137 java::lang::LinkageError
*le
= new java::lang::LinkageError
139 ("field type mismatch with different loaders"));
147 // Note that we compare type names and not types. This is
148 // bizarre, but we do it because we want to find a field
149 // (and terminate the search) if it has the correct
150 // descriptor -- but then later reject it if the class
151 // loader check results in different classes. We can't just
152 // pass in the descriptor and check that way, because when
153 // the field is already resolved there is no easy way to
154 // find its descriptor again.
155 if ((field
->isResolved ()
156 ? _Jv_equalUtf8Classnames (type_name
, field
->type
->name
)
157 : _Jv_equalUtf8Classnames (type_name
,
158 (_Jv_Utf8Const
*) field
->type
)))
165 // Next search direct interfaces.
166 for (int i
= 0; i
< search
->interface_count
; ++i
)
168 _Jv_Field
*result
= find_field_helper (search
->interfaces
[i
], name
,
169 type_name
, type
, declarer
);
174 // Now search superclass.
175 search
= search
->superclass
;
182 _Jv_Linker::has_field_p (jclass search
, _Jv_Utf8Const
*field_name
)
184 for (int i
= 0; i
< search
->field_count
; ++i
)
186 _Jv_Field
*field
= &search
->fields
[i
];
187 if (_Jv_equalUtf8Consts (field
->name
, field_name
))
194 // KLASS is the class that is requesting the field.
195 // OWNER is the class in which the field should be found.
196 // FIELD_TYPE_NAME is the type descriptor for the field.
197 // Fill FOUND_CLASS with the address of the class in which the field
198 // is actually declared.
199 // This function does the class loader type checks, and
200 // also access checks. Returns the field, or throws an
201 // exception on error.
203 _Jv_Linker::find_field (jclass klass
, jclass owner
,
205 _Jv_Utf8Const
*field_name
,
206 _Jv_Utf8Const
*field_type_name
)
208 // FIXME: this allocates a _Jv_Utf8Const each time. We should make
210 // Note: This call will resolve the primitive type names ("Z", "B", ...) to
211 // their Java counterparts ("boolean", "byte", ...) if accessed via
212 // field_type->name later. Using these variants of the type name is in turn
213 // important for the find_field_helper function. However if the class
214 // resolution failed then we can only use the already given type name.
216 = _Jv_FindClassFromSignatureNoException (field_type_name
->chars(),
220 = find_field_helper (owner
, field_name
,
224 field_type
, found_class
);
228 java::lang::StringBuffer
*sb
= new java::lang::StringBuffer();
229 sb
->append(JvNewStringLatin1("field "));
230 sb
->append(owner
->getName());
231 sb
->append(JvNewStringLatin1("."));
232 sb
->append(_Jv_NewStringUTF(field_name
->chars()));
233 sb
->append(JvNewStringLatin1(" was not found."));
234 throw new java::lang::NoSuchFieldError (sb
->toString());
237 // Accept it when the field's class could not be resolved.
238 if (field_type
== NULL
)
239 // Silently ignore that we were not able to retrieve the type to make it
240 // possible to run code which does not access this field.
243 if (_Jv_CheckAccess (klass
, *found_class
, the_field
->flags
))
245 // Note that the field returned by find_field_helper is always
246 // resolved. There's no point checking class loaders here,
247 // since we already did the work to look up all the types.
248 // FIXME: being lazy here would be nice.
249 if (the_field
->type
!= field_type
)
250 throw new java::lang::LinkageError
252 ("field type mismatch with different loaders"));
256 java::lang::StringBuffer
*sb
257 = new java::lang::StringBuffer ();
258 sb
->append(klass
->getName());
259 sb
->append(JvNewStringLatin1(": "));
260 sb
->append((*found_class
)->getName());
261 sb
->append(JvNewStringLatin1("."));
262 sb
->append(_Jv_NewStringUtf8Const (field_name
));
263 throw new java::lang::IllegalAccessError(sb
->toString());
270 _Jv_Linker::resolve_method_entry (jclass klass
, jclass
&found_class
,
271 int class_index
, int name_and_type_index
,
272 bool init
, bool is_iface
)
274 _Jv_Constants
*pool
= &klass
->constants
;
275 jclass owner
= resolve_pool_entry (klass
, class_index
).clazz
;
277 if (init
&& owner
!= klass
)
278 _Jv_InitClass (owner
);
280 _Jv_ushort name_index
, type_index
;
281 _Jv_loadIndexes (&pool
->data
[name_and_type_index
],
285 _Jv_Utf8Const
*method_name
= pool
->data
[name_index
].utf8
;
286 _Jv_Utf8Const
*method_signature
= pool
->data
[type_index
].utf8
;
288 _Jv_Method
*the_method
= 0;
291 // We're going to cache a pointer to the _Jv_Method object
292 // when we find it. So, to ensure this doesn't get moved from
293 // beneath us, we first put all the needed Miranda methods
294 // into the target class.
295 wait_for_state (klass
, JV_STATE_LOADED
);
297 // First search the class itself.
298 the_method
= search_method_in_class (owner
, klass
,
299 method_name
, method_signature
);
304 goto end_of_method_search
;
307 // If we are resolving an interface method, search the
308 // interface's superinterfaces (A superinterface is not an
309 // interface's superclass - a superinterface is implemented by
316 ifaces
.list
= (jclass
*) _Jv_Malloc (ifaces
.len
317 * sizeof (jclass
*));
319 get_interfaces (owner
, &ifaces
);
321 for (int i
= 0; i
< ifaces
.count
; i
++)
323 jclass cls
= ifaces
.list
[i
];
324 the_method
= search_method_in_class (cls
, klass
, method_name
,
333 _Jv_Free (ifaces
.list
);
336 goto end_of_method_search
;
339 // Finally, search superclasses.
340 the_method
= (search_method_in_superclasses
341 (owner
->getSuperclass (), klass
, method_name
,
342 method_signature
, &found_class
));
345 end_of_method_search
:
348 java::lang::StringBuffer
*sb
= new java::lang::StringBuffer();
349 sb
->append(JvNewStringLatin1("method "));
350 sb
->append(owner
->getName());
351 sb
->append(JvNewStringLatin1("."));
352 sb
->append(_Jv_NewStringUTF(method_name
->chars()));
353 sb
->append(JvNewStringLatin1(" with signature "));
354 sb
->append(_Jv_NewStringUTF(method_signature
->chars()));
355 sb
->append(JvNewStringLatin1(" was not found."));
356 throw new java::lang::NoSuchMethodError (sb
->toString());
359 // if (found_class->loader != klass->loader), then we
360 // must actually check that the types of arguments
361 // correspond. That is, for each argument type, and
362 // the return type, doing _Jv_FindClassFromSignature
363 // with either loader should produce the same result,
364 // i.e., exactly the same jclass object. JVMS 5.4.3.3
365 if (found_class
->loader
!= klass
->loader
)
367 JArray
<jclass
> *found_args
, *klass_args
;
368 jclass found_return
, klass_return
;
370 _Jv_GetTypesFromSignature (the_method
,
374 _Jv_GetTypesFromSignature (the_method
,
379 jclass
*found_arg
= elements (found_args
);
380 jclass
*klass_arg
= elements (klass_args
);
382 for (int i
= 0; i
< found_args
->length
; i
++)
384 if (*(found_arg
++) != *(klass_arg
++))
385 throw new java::lang::LinkageError (JvNewStringLatin1
386 ("argument type mismatch with different loaders"));
388 if (found_return
!= klass_return
)
389 throw new java::lang::LinkageError (JvNewStringLatin1
390 ("return type mismatch with different loaders"));
397 _Jv_Linker::resolve_pool_entry (jclass klass
, int index
, bool lazy
)
399 using namespace java::lang::reflect
;
401 if (GC_base (klass
) && klass
->constants
.data
402 && ! GC_base (klass
->constants
.data
))
404 jsize count
= klass
->constants
.size
;
408 = (_Jv_word
*) _Jv_AllocRawObj (count
* sizeof (_Jv_word
));
409 memcpy ((void*)constants
,
410 (void*)klass
->constants
.data
,
411 count
* sizeof (_Jv_word
));
412 klass
->constants
.data
= constants
;
416 _Jv_Constants
*pool
= &klass
->constants
;
418 if ((pool
->tags
[index
] & JV_CONSTANT_ResolvedFlag
) != 0)
419 return pool
->data
[index
];
421 switch (pool
->tags
[index
] & ~JV_CONSTANT_LazyFlag
)
423 case JV_CONSTANT_Class
:
425 _Jv_Utf8Const
*name
= pool
->data
[index
].utf8
;
428 if (name
->first() == '[')
429 found
= _Jv_FindClassFromSignatureNoException (name
->chars(),
432 found
= _Jv_FindClassNoException (name
, klass
->loader
);
434 // If the class could not be loaded a phantom class is created. Any
435 // function that deals with such a class but cannot do something useful
436 // with it should just throw a NoClassDefFoundError with the class'
442 found
= _Jv_NewClass(name
, NULL
, NULL
);
443 found
->state
= JV_STATE_PHANTOM
;
444 pool
->tags
[index
] |= JV_CONSTANT_ResolvedFlag
;
445 pool
->data
[index
].clazz
= found
;
449 throw new java::lang::NoClassDefFoundError (name
->toString());
452 // Check accessibility, but first strip array types as
453 // _Jv_ClassNameSamePackage can't handle arrays.
456 check
&& check
->isArray();
457 check
= check
->getComponentType())
459 if ((found
->accflags
& Modifier::PUBLIC
) == Modifier::PUBLIC
460 || (_Jv_ClassNameSamePackage (check
->name
,
463 pool
->data
[index
].clazz
= found
;
464 pool
->tags
[index
] |= JV_CONSTANT_ResolvedFlag
;
468 java::lang::StringBuffer
*sb
= new java::lang::StringBuffer ();
469 sb
->append(klass
->getName());
470 sb
->append(JvNewStringLatin1(" can't access class "));
471 sb
->append(found
->getName());
472 throw new java::lang::IllegalAccessError(sb
->toString());
477 case JV_CONSTANT_String
:
480 str
= _Jv_NewStringUtf8Const (pool
->data
[index
].utf8
);
481 pool
->data
[index
].o
= str
;
482 pool
->tags
[index
] |= JV_CONSTANT_ResolvedFlag
;
486 case JV_CONSTANT_Fieldref
:
488 _Jv_ushort class_index
, name_and_type_index
;
489 _Jv_loadIndexes (&pool
->data
[index
],
491 name_and_type_index
);
492 jclass owner
= (resolve_pool_entry (klass
, class_index
, true)).clazz
;
494 // If a phantom class was resolved our field reference is
495 // unusable because of the missing class.
496 if (owner
->state
== JV_STATE_PHANTOM
)
497 throw new java::lang::NoClassDefFoundError(owner
->getName());
499 // We don't initialize 'owner', but we do make sure that its
501 wait_for_state (owner
, JV_STATE_PREPARED
);
503 _Jv_ushort name_index
, type_index
;
504 _Jv_loadIndexes (&pool
->data
[name_and_type_index
],
508 _Jv_Utf8Const
*field_name
= pool
->data
[name_index
].utf8
;
509 _Jv_Utf8Const
*field_type_name
= pool
->data
[type_index
].utf8
;
511 jclass found_class
= 0;
512 _Jv_Field
*the_field
= find_field (klass
, owner
,
516 // Initialize the field's declaring class, not its qualifying
518 _Jv_InitClass (found_class
);
519 pool
->data
[index
].field
= the_field
;
520 pool
->tags
[index
] |= JV_CONSTANT_ResolvedFlag
;
524 case JV_CONSTANT_Methodref
:
525 case JV_CONSTANT_InterfaceMethodref
:
527 _Jv_ushort class_index
, name_and_type_index
;
528 _Jv_loadIndexes (&pool
->data
[index
],
530 name_and_type_index
);
532 _Jv_Method
*the_method
;
534 the_method
= resolve_method_entry (klass
, found_class
,
535 class_index
, name_and_type_index
,
537 pool
->tags
[index
] == JV_CONSTANT_InterfaceMethodref
);
539 pool
->data
[index
].rmethod
540 = klass
->engine
->resolve_method(the_method
,
542 ((the_method
->accflags
543 & Modifier::STATIC
) != 0));
544 pool
->tags
[index
] |= JV_CONSTANT_ResolvedFlag
;
548 return pool
->data
[index
];
551 // This function is used to lazily locate superclasses and
552 // superinterfaces. This must be called with the class lock held.
554 _Jv_Linker::resolve_class_ref (jclass klass
, jclass
*classref
)
556 jclass ret
= *classref
;
558 // If superclass looks like a constant pool entry, resolve it now.
559 if (ret
&& (uaddr
) ret
< (uaddr
) klass
->constants
.size
)
561 if (klass
->state
< JV_STATE_LINKED
)
563 _Jv_Utf8Const
*name
= klass
->constants
.data
[(uaddr
) *classref
].utf8
;
564 ret
= _Jv_FindClass (name
, klass
->loader
);
567 throw new java::lang::NoClassDefFoundError (name
->toString());
571 ret
= klass
->constants
.data
[(uaddr
) classref
].clazz
;
576 // Find a method declared in the cls that is referenced from klass and
577 // perform access checks if CHECK_PERMS is true.
579 _Jv_Linker::search_method_in_class (jclass cls
, jclass klass
,
580 _Jv_Utf8Const
*method_name
,
581 _Jv_Utf8Const
*method_signature
,
584 using namespace java::lang::reflect
;
586 for (int i
= 0; i
< cls
->method_count
; i
++)
588 _Jv_Method
*method
= &cls
->methods
[i
];
589 if ( (!_Jv_equalUtf8Consts (method
->name
,
591 || (!_Jv_equalUtf8Consts (method
->signature
,
595 if (!check_perms
|| _Jv_CheckAccess (klass
, cls
, method
->accflags
))
599 java::lang::StringBuffer
*sb
= new java::lang::StringBuffer();
600 sb
->append(klass
->getName());
601 sb
->append(JvNewStringLatin1(": "));
602 sb
->append(cls
->getName());
603 sb
->append(JvNewStringLatin1("."));
604 sb
->append(_Jv_NewStringUTF(method_name
->chars()));
605 sb
->append(_Jv_NewStringUTF(method_signature
->chars()));
606 throw new java::lang::IllegalAccessError (sb
->toString());
612 // Like search_method_in_class, but work our way up the superclass
615 _Jv_Linker::search_method_in_superclasses (jclass cls
, jclass klass
,
616 _Jv_Utf8Const
*method_name
,
617 _Jv_Utf8Const
*method_signature
,
618 jclass
*found_class
, bool check_perms
)
620 _Jv_Method
*the_method
= NULL
;
622 for ( ; cls
!= 0; cls
= cls
->getSuperclass ())
624 the_method
= search_method_in_class (cls
, klass
, method_name
,
625 method_signature
, check_perms
);
637 #define INITIAL_IOFFSETS_LEN 4
638 #define INITIAL_IFACES_LEN 4
640 static _Jv_IDispatchTable null_idt
= {SHRT_MAX
, 0, {}};
642 // Generate tables for constant-time assignment testing and interface
643 // method lookup. This implements the technique described by Per Bothner
644 // <per@bothner.com> on the java-discuss mailing list on 1999-09-02:
645 // http://gcc.gnu.org/ml/java/1999-q3/msg00377.html
647 _Jv_Linker::prepare_constant_time_tables (jclass klass
)
649 if (klass
->isPrimitive () || klass
->isInterface ())
652 // Short-circuit in case we've been called already.
653 if ((klass
->idt
!= NULL
) || klass
->depth
!= 0)
656 // Calculate the class depth and ancestor table. The depth of a class
657 // is how many "extends" it is removed from Object. Thus the depth of
658 // java.lang.Object is 0, but the depth of java.io.FilterOutputStream
659 // is 2. Depth is defined for all regular and array classes, but not
660 // interfaces or primitive types.
662 jclass klass0
= klass
;
663 jboolean has_interfaces
= 0;
664 while (klass0
!= &java::lang::Object::class$
)
666 has_interfaces
+= klass0
->interface_count
;
667 klass0
= klass0
->superclass
;
671 // We do class member testing in constant time by using a small table
672 // of all the ancestor classes within each class. The first element is
673 // a pointer to the current class, and the rest are pointers to the
674 // classes ancestors, ordered from the current class down by decreasing
675 // depth. We do not include java.lang.Object in the table of ancestors,
676 // since it is redundant. Note that the classes pointed to by
677 // 'ancestors' will always be reachable by other paths.
679 klass
->ancestors
= (jclass
*) _Jv_AllocBytes (klass
->depth
682 for (int index
= 0; index
< klass
->depth
; index
++)
684 klass
->ancestors
[index
] = klass0
;
685 klass0
= klass0
->superclass
;
688 if ((klass
->accflags
& java::lang::reflect::Modifier::ABSTRACT
) != 0)
691 // Optimization: If class implements no interfaces, use a common
692 // predefined interface table.
695 klass
->idt
= &null_idt
;
701 ifaces
.len
= INITIAL_IFACES_LEN
;
702 ifaces
.list
= (jclass
*) _Jv_Malloc (ifaces
.len
* sizeof (jclass
*));
704 int itable_size
= get_interfaces (klass
, &ifaces
);
706 if (ifaces
.count
> 0)
708 // The classes pointed to by the itable will always be reachable
710 int idt_bytes
= sizeof (_Jv_IDispatchTable
) + (itable_size
712 klass
->idt
= (_Jv_IDispatchTable
*) _Jv_AllocBytes (idt_bytes
);
713 klass
->idt
->itable_length
= itable_size
;
715 jshort
*itable_offsets
=
716 (jshort
*) _Jv_Malloc (ifaces
.count
* sizeof (jshort
));
718 generate_itable (klass
, &ifaces
, itable_offsets
);
720 jshort cls_iindex
= find_iindex (ifaces
.list
, itable_offsets
,
723 for (int i
= 0; i
< ifaces
.count
; i
++)
725 ifaces
.list
[i
]->ioffsets
[cls_iindex
] = itable_offsets
[i
];
728 klass
->idt
->iindex
= cls_iindex
;
730 _Jv_Free (ifaces
.list
);
731 _Jv_Free (itable_offsets
);
735 klass
->idt
->iindex
= SHRT_MAX
;
739 // Return index of item in list, or -1 if item is not present.
741 _Jv_Linker::indexof (void *item
, void **list
, jshort list_len
)
743 for (int i
=0; i
< list_len
; i
++)
751 // Find all unique interfaces directly or indirectly implemented by klass.
752 // Returns the size of the interface dispatch table (itable) for klass, which
753 // is the number of unique interfaces plus the total number of methods that
754 // those interfaces declare. May extend ifaces if required.
756 _Jv_Linker::get_interfaces (jclass klass
, _Jv_ifaces
*ifaces
)
760 for (int i
= 0; i
< klass
->interface_count
; i
++)
762 jclass iface
= klass
->interfaces
[i
];
764 /* Make sure interface is linked. */
765 wait_for_state(iface
, JV_STATE_LINKED
);
767 if (indexof (iface
, (void **) ifaces
->list
, ifaces
->count
) == -1)
769 if (ifaces
->count
+ 1 >= ifaces
->len
)
771 /* Resize ifaces list */
772 ifaces
->len
= ifaces
->len
* 2;
774 = (jclass
*) _Jv_Realloc (ifaces
->list
,
775 ifaces
->len
* sizeof(jclass
));
777 ifaces
->list
[ifaces
->count
] = iface
;
780 result
+= get_interfaces (klass
->interfaces
[i
], ifaces
);
784 if (klass
->isInterface())
786 // We want to add 1 plus the number of interface methods here.
787 // But, we take special care to skip <clinit>.
789 for (int i
= 0; i
< klass
->method_count
; ++i
)
791 if (klass
->methods
[i
].name
->first() != '<')
795 else if (klass
->superclass
)
796 result
+= get_interfaces (klass
->superclass
, ifaces
);
800 // Fill out itable in klass, resolving method declarations in each ifaces.
801 // itable_offsets is filled out with the position of each iface in itable,
802 // such that itable[itable_offsets[n]] == ifaces.list[n].
804 _Jv_Linker::generate_itable (jclass klass
, _Jv_ifaces
*ifaces
,
805 jshort
*itable_offsets
)
807 void **itable
= klass
->idt
->itable
;
808 jshort itable_pos
= 0;
810 for (int i
= 0; i
< ifaces
->count
; i
++)
812 jclass iface
= ifaces
->list
[i
];
813 itable_offsets
[i
] = itable_pos
;
814 itable_pos
= append_partial_itable (klass
, iface
, itable
, itable_pos
);
816 /* Create ioffsets table for iface */
817 if (iface
->ioffsets
== NULL
)
819 // The first element of ioffsets is its length (itself included).
820 jshort
*ioffsets
= (jshort
*) _Jv_AllocBytes (INITIAL_IOFFSETS_LEN
822 ioffsets
[0] = INITIAL_IOFFSETS_LEN
;
823 for (int i
= 1; i
< INITIAL_IOFFSETS_LEN
; i
++)
826 iface
->ioffsets
= ioffsets
;
831 // Format method name for use in error messages.
833 _Jv_GetMethodString (jclass klass
, _Jv_Method
*meth
,
836 using namespace java::lang
;
837 StringBuffer
*buf
= new StringBuffer (klass
->name
->toString());
838 buf
->append (jchar ('.'));
839 buf
->append (meth
->name
->toString());
840 buf
->append ((jchar
) ' ');
841 buf
->append (meth
->signature
->toString());
844 buf
->append(JvNewStringLatin1(" in "));
845 buf
->append(derived
->name
->toString());
847 return buf
->toString();
851 _Jv_ThrowNoSuchMethodError ()
853 throw new java::lang::NoSuchMethodError
;
856 #if defined USE_LIBFFI && FFI_CLOSURES
857 // A function whose invocation is prepared using libffi. It gets called
858 // whenever a static method of a missing class is invoked. The data argument
859 // holds a reference to a String denoting the missing class.
860 // The prepared function call is stored in a class' atable.
862 _Jv_ThrowNoClassDefFoundErrorTrampoline(ffi_cif
*,
867 throw new java::lang::NoClassDefFoundError(
868 _Jv_NewStringUtf8Const((_Jv_Utf8Const
*) data
));
871 // A variant of the NoClassDefFoundError throwing method that can
872 // be used without libffi.
874 _Jv_ThrowNoClassDefFoundError()
876 throw new java::lang::NoClassDefFoundError();
880 // Throw a NoSuchFieldError. Called by compiler-generated code when
881 // an otable entry is zero. OTABLE_INDEX is the index in the caller's
882 // otable that refers to the missing field. This index may be used to
883 // print diagnostic information about the field.
885 _Jv_ThrowNoSuchFieldError (int /* otable_index */)
887 throw new java::lang::NoSuchFieldError
;
890 // This is put in empty vtable slots.
892 _Jv_ThrowAbstractMethodError ()
894 throw new java::lang::AbstractMethodError();
897 // Each superinterface of a class (i.e. each interface that the class
898 // directly or indirectly implements) has a corresponding "Partial
899 // Interface Dispatch Table" whose size is (number of methods + 1) words.
900 // The first word is a pointer to the interface (i.e. the java.lang.Class
901 // instance for that interface). The remaining words are pointers to the
902 // actual methods that implement the methods declared in the interface,
903 // in order of declaration.
905 // Append partial interface dispatch table for "iface" to "itable", at
906 // position itable_pos.
907 // Returns the offset at which the next partial ITable should be appended.
909 _Jv_Linker::append_partial_itable (jclass klass
, jclass iface
,
910 void **itable
, jshort pos
)
912 using namespace java::lang::reflect
;
914 itable
[pos
++] = (void *) iface
;
917 for (int j
=0; j
< iface
->method_count
; j
++)
919 // Skip '<clinit>' here.
920 if (iface
->methods
[j
].name
->first() == '<')
924 for (jclass cl
= klass
; cl
; cl
= cl
->getSuperclass())
926 meth
= _Jv_GetMethodLocal (cl
, iface
->methods
[j
].name
,
927 iface
->methods
[j
].signature
);
935 if ((meth
->accflags
& Modifier::STATIC
) != 0)
936 throw new java::lang::IncompatibleClassChangeError
937 (_Jv_GetMethodString (klass
, meth
));
938 if ((meth
->accflags
& Modifier::PUBLIC
) == 0)
939 throw new java::lang::IllegalAccessError
940 (_Jv_GetMethodString (klass
, meth
));
942 if ((meth
->accflags
& Modifier::ABSTRACT
) != 0)
943 itable
[pos
] = (void *) &_Jv_ThrowAbstractMethodError
;
945 itable
[pos
] = meth
->ncode
;
949 // The method doesn't exist in klass. Binary compatibility rules
950 // permit this, so we delay the error until runtime using a pointer
951 // to a method which throws an exception.
952 itable
[pos
] = (void *) _Jv_ThrowNoSuchMethodError
;
960 static _Jv_Mutex_t iindex_mutex
;
961 static bool iindex_mutex_initialized
= false;
963 // We need to find the correct offset in the Class Interface Dispatch
964 // Table for a given interface. Once we have that, invoking an interface
965 // method just requires combining the Method's index in the interface
966 // (known at compile time) to get the correct method. Doing a type test
967 // (cast or instanceof) is the same problem: Once we have a possible Partial
968 // Interface Dispatch Table, we just compare the first element to see if it
969 // matches the desired interface. So how can we find the correct offset?
970 // Our solution is to keep a vector of candiate offsets in each interface
971 // (ioffsets), and in each class we have an index (idt->iindex) used to
972 // select the correct offset from ioffsets.
974 // Calculate and return iindex for a new class.
975 // ifaces is a vector of num interfaces that the class implements.
976 // offsets[j] is the offset in the interface dispatch table for the
977 // interface corresponding to ifaces[j].
978 // May extend the interface ioffsets if required.
980 _Jv_Linker::find_iindex (jclass
*ifaces
, jshort
*offsets
, jshort num
)
985 // Acquire a global lock to prevent itable corruption in case of multiple
986 // classes that implement an intersecting set of interfaces being linked
987 // simultaneously. We can assume that the mutex will be initialized
989 if (! iindex_mutex_initialized
)
991 _Jv_MutexInit (&iindex_mutex
);
992 iindex_mutex_initialized
= true;
995 _Jv_MutexLock (&iindex_mutex
);
997 for (i
=1;; i
++) /* each potential position in ioffsets */
999 for (j
=0;; j
++) /* each iface */
1003 if (i
>= ifaces
[j
]->ioffsets
[0])
1005 int ioffset
= ifaces
[j
]->ioffsets
[i
];
1006 /* We can potentially share this position with another class. */
1007 if (ioffset
>= 0 && ioffset
!= offsets
[j
])
1008 break; /* Nope. Try next i. */
1012 for (j
= 0; j
< num
; j
++)
1014 int len
= ifaces
[j
]->ioffsets
[0];
1018 int newlen
= 2 * len
;
1022 jshort
*old_ioffsets
= ifaces
[j
]->ioffsets
;
1023 jshort
*new_ioffsets
= (jshort
*) _Jv_AllocBytes (newlen
1025 memcpy (&new_ioffsets
[1], &old_ioffsets
[1],
1026 (len
- 1) * sizeof (jshort
));
1027 new_ioffsets
[0] = newlen
;
1029 while (len
< newlen
)
1030 new_ioffsets
[len
++] = -1;
1032 ifaces
[j
]->ioffsets
= new_ioffsets
;
1034 ifaces
[j
]->ioffsets
[i
] = offsets
[j
];
1037 _Jv_MutexUnlock (&iindex_mutex
);
1042 #if defined USE_LIBFFI && FFI_CLOSURES
1043 // We use a structure of this type to store the closure that
1044 // represents a missing method.
1045 struct method_closure
1047 // This field must come first, since the address of this field will
1048 // be the same as the address of the overall structure. This is due
1049 // to disabling interior pointers in the GC.
1050 ffi_closure closure
;
1051 _Jv_ClosureList list
;
1053 ffi_type
*arg_types
[1];
1057 _Jv_Linker::create_error_method (_Jv_Utf8Const
*class_name
, jclass klass
)
1060 method_closure
*closure
1061 = (method_closure
*)ffi_closure_alloc (sizeof (method_closure
), &code
);
1063 closure
->arg_types
[0] = &ffi_type_void
;
1065 // Initializes the cif and the closure. If that worked the closure
1066 // is returned and can be used as a function pointer in a class'
1068 if ( ffi_prep_cif (&closure
->cif
,
1072 closure
->arg_types
) == FFI_OK
1073 && ffi_prep_closure_loc (&closure
->closure
,
1075 _Jv_ThrowNoClassDefFoundErrorTrampoline
,
1079 closure
->list
.registerClosure (klass
, closure
);
1084 ffi_closure_free (closure
);
1085 java::lang::StringBuffer
*buffer
= new java::lang::StringBuffer();
1086 buffer
->append(JvNewStringLatin1("Error setting up FFI closure"
1087 " for static method of"
1088 " missing class: "));
1089 buffer
->append (_Jv_NewStringUtf8Const(class_name
));
1090 throw new java::lang::InternalError(buffer
->toString());
1095 _Jv_Linker::create_error_method (_Jv_Utf8Const
*, jclass
)
1097 // Codepath for platforms which do not support (or want) libffi.
1098 // You have to accept that it is impossible to provide the name
1099 // of the missing class then.
1100 return (void *) _Jv_ThrowNoClassDefFoundError
;
1102 #endif // USE_LIBFFI && FFI_CLOSURES
1104 // Functions for indirect dispatch (symbolic virtual binding) support.
1106 // There are three tables, atable otable and itable. atable is an
1107 // array of addresses, and otable is an array of offsets, and these
1108 // are used for static and virtual members respectively. itable is an
1109 // array of pairs {address, index} where each address is a pointer to
1112 // {a,o,i}table_syms is an array of _Jv_MethodSymbols. Each such
1113 // symbol is a tuple of {classname, member name, signature}.
1115 // Set this to true to enable debugging of indirect dispatch tables/linking.
1116 static bool debug_link
= false;
1118 // link_symbol_table() scans these two arrays and fills in the
1119 // corresponding atable and otable with the addresses of static
1120 // members and the offsets of virtual members.
1122 // The offset (in bytes) for each resolved method or field is placed
1123 // at the corresponding position in the virtual method offset table
1126 // This must be called while holding the class lock.
1129 _Jv_Linker::link_symbol_table (jclass klass
)
1132 _Jv_MethodSymbol sym
;
1133 if (klass
->otable
== NULL
1134 || klass
->otable
->state
!= 0)
1137 klass
->otable
->state
= 1;
1140 fprintf (stderr
, "Fixing up otable in %s:\n", klass
->name
->chars());
1142 (sym
= klass
->otable_syms
[index
]).class_name
!= NULL
;
1145 jclass target_class
= _Jv_FindClass (sym
.class_name
, klass
->loader
);
1146 _Jv_Method
*meth
= NULL
;
1148 _Jv_Utf8Const
*signature
= sym
.signature
;
1150 maybe_adjust_signature (signature
, special
);
1152 if (target_class
== NULL
)
1153 throw new java::lang::NoClassDefFoundError
1154 (_Jv_NewStringUTF (sym
.class_name
->chars()));
1156 // We're looking for a field or a method, and we can tell
1157 // which is needed by looking at the signature.
1158 if (signature
->first() == '(' && signature
->len() >= 2)
1160 // Looks like someone is trying to invoke an interface method
1161 if (target_class
->isInterface())
1163 using namespace java::lang
;
1164 StringBuffer
*sb
= new StringBuffer();
1165 sb
->append(JvNewStringLatin1("found interface "));
1166 sb
->append(target_class
->getName());
1167 sb
->append(JvNewStringLatin1(" when searching for a class"));
1168 throw new VerifyError(sb
->toString());
1171 // If the target class does not have a vtable_method_count yet,
1172 // then we can't tell the offsets for its methods, so we must lay
1174 wait_for_state(target_class
, JV_STATE_PREPARED
);
1178 meth
= (search_method_in_superclasses
1179 (target_class
, klass
, sym
.name
, signature
,
1180 NULL
, special
== 0));
1182 catch (::java::lang::IllegalAccessError
*e
)
1186 // Every class has a throwNoSuchMethodErrorIndex method that
1187 // it inherits from java.lang.Object. Find its vtable
1189 static int throwNoSuchMethodErrorIndex
;
1190 if (throwNoSuchMethodErrorIndex
== 0)
1193 = _Jv_makeUtf8Const ("throwNoSuchMethodError",
1194 strlen ("throwNoSuchMethodError"));
1196 = _Jv_LookupDeclaredMethod (&java::lang::Object::class$
,
1197 name
, gcj::void_signature
);
1198 throwNoSuchMethodErrorIndex
1199 = _Jv_VTable::idx_to_offset (meth
->index
);
1202 // If we don't find a nonstatic method, insert the
1203 // vtable index of Object.throwNoSuchMethodError().
1204 // This defers the missing method error until an attempt
1205 // is made to execute it.
1210 offset
= _Jv_VTable::idx_to_offset (meth
->index
);
1212 offset
= throwNoSuchMethodErrorIndex
;
1215 JvFail ("Bad method index");
1216 JvAssert (meth
->index
< target_class
->vtable_method_count
);
1218 klass
->otable
->offsets
[index
] = offset
;
1222 fprintf (stderr
, " offsets[%d] = %d (class %s@%p : %s(%s))\n",
1224 (int)klass
->otable
->offsets
[index
],
1225 (const char*)target_class
->name
->chars(),
1227 (const char*)sym
.name
->chars(),
1228 (const char*)signature
->chars());
1234 wait_for_state(target_class
, JV_STATE_PREPARED
);
1236 _Jv_Field
*the_field
= NULL
;
1239 the_field
= find_field (klass
, target_class
, &found_class
,
1240 sym
.name
, signature
);
1241 if ((the_field
->flags
& java::lang::reflect::Modifier::STATIC
))
1242 throw new java::lang::IncompatibleClassChangeError
;
1244 klass
->otable
->offsets
[index
] = the_field
->u
.boffset
;
1246 catch (java::lang::NoSuchFieldError
*err
)
1248 klass
->otable
->offsets
[index
] = 0;
1254 if (klass
->atable
== NULL
|| klass
->atable
->state
!= 0)
1257 klass
->atable
->state
= 1;
1260 (sym
= klass
->atable_syms
[index
]).class_name
!= NULL
;
1263 jclass target_class
=
1264 _Jv_FindClassNoException (sym
.class_name
, klass
->loader
);
1266 _Jv_Method
*meth
= NULL
;
1268 _Jv_Utf8Const
*signature
= sym
.signature
;
1270 maybe_adjust_signature (signature
, special
);
1272 // ??? Setting this pointer to null will at least get us a
1273 // NullPointerException
1274 klass
->atable
->addresses
[index
] = NULL
;
1276 bool use_error_method
= false;
1278 // If the target class is missing we prepare a function call
1279 // that throws a NoClassDefFoundError and store the address of
1280 // that newly prepared method in the atable. The user can run
1281 // code in classes where the missing class is part of the
1282 // execution environment as long as it is never referenced.
1283 if (target_class
== NULL
)
1284 use_error_method
= true;
1285 // We're looking for a static field or a static method, and we
1286 // can tell which is needed by looking at the signature.
1287 else if (signature
->first() == '(' && signature
->len() >= 2)
1289 // If the target class does not have a vtable_method_count yet,
1290 // then we can't tell the offsets for its methods, so we must lay
1292 wait_for_state (target_class
, JV_STATE_PREPARED
);
1294 // Interface methods cannot have bodies.
1295 if (target_class
->isInterface())
1297 using namespace java::lang
;
1298 StringBuffer
*sb
= new StringBuffer();
1299 sb
->append(JvNewStringLatin1("class "));
1300 sb
->append(target_class
->getName());
1301 sb
->append(JvNewStringLatin1(" is an interface: "
1303 throw new VerifyError(sb
->toString());
1308 meth
= (search_method_in_superclasses
1309 (target_class
, klass
, sym
.name
, signature
,
1310 NULL
, special
== 0));
1312 catch (::java::lang::IllegalAccessError
*e
)
1318 if (meth
->ncode
) // Maybe abstract?
1320 klass
->atable
->addresses
[index
] = meth
->ncode
;
1322 fprintf (stderr
, " addresses[%d] = %p (class %s@%p : %s(%s))\n",
1324 &klass
->atable
->addresses
[index
],
1325 (const char*)target_class
->name
->chars(),
1327 (const char*)sym
.name
->chars(),
1328 (const char*)signature
->chars());
1332 use_error_method
= true;
1334 if (use_error_method
)
1335 klass
->atable
->addresses
[index
]
1336 = create_error_method(sym
.class_name
, klass
);
1342 // Try fields only if the target class exists.
1343 if (target_class
!= NULL
)
1345 wait_for_state(target_class
, JV_STATE_PREPARED
);
1347 _Jv_Field
*the_field
= find_field (klass
, target_class
, &found_class
,
1348 sym
.name
, signature
);
1349 if ((the_field
->flags
& java::lang::reflect::Modifier::STATIC
))
1350 klass
->atable
->addresses
[index
] = the_field
->u
.addr
;
1352 throw new java::lang::IncompatibleClassChangeError
;
1357 if (klass
->itable
== NULL
1358 || klass
->itable
->state
!= 0)
1361 klass
->itable
->state
= 1;
1364 (sym
= klass
->itable_syms
[index
]).class_name
!= NULL
;
1367 jclass target_class
= _Jv_FindClass (sym
.class_name
, klass
->loader
);
1369 _Jv_Utf8Const
*signature
= sym
.signature
;
1371 maybe_adjust_signature (signature
, special
);
1376 wait_for_state(target_class
, JV_STATE_LOADED
);
1377 bool found
= _Jv_getInterfaceMethod (target_class
, cls
, i
,
1378 sym
.name
, signature
);
1382 klass
->itable
->addresses
[index
* 2] = cls
;
1383 klass
->itable
->addresses
[index
* 2 + 1] = (void *)(unsigned long) i
;
1386 fprintf (stderr
, " interfaces[%d] = %p (interface %s@%p : %s(%s))\n",
1388 klass
->itable
->addresses
[index
* 2],
1389 (const char*)cls
->name
->chars(),
1391 (const char*)sym
.name
->chars(),
1392 (const char*)signature
->chars());
1393 fprintf (stderr
, " [%d] = offset %d\n",
1395 (int)(unsigned long)klass
->itable
->addresses
[index
* 2 + 1]);
1400 throw new java::lang::IncompatibleClassChangeError
;
1405 // For each catch_record in the list of caught classes, fill in the
1408 _Jv_Linker::link_exception_table (jclass self
)
1410 struct _Jv_CatchClass
*catch_record
= self
->catch_classes
;
1411 if (!catch_record
|| catch_record
->classname
)
1414 while (catch_record
->classname
)
1419 = _Jv_FindClass (catch_record
->classname
,
1420 self
->getClassLoaderInternal ());
1421 *catch_record
->address
= target_class
;
1423 catch (::java::lang::Throwable
*t
)
1425 // FIXME: We need to do something better here.
1426 *catch_record
->address
= 0;
1430 self
->catch_classes
->classname
= (_Jv_Utf8Const
*)-1;
1433 // Set itable method indexes for members of interface IFACE.
1435 _Jv_Linker::layout_interface_methods (jclass iface
)
1437 if (! iface
->isInterface())
1440 // itable indexes start at 1.
1441 // FIXME: Static initalizers currently get a NULL placeholder entry in the
1442 // itable so they are also assigned an index here.
1443 for (int i
= 0; i
< iface
->method_count
; i
++)
1444 iface
->methods
[i
].index
= i
+ 1;
1447 // Prepare virtual method declarations in KLASS, and any superclasses
1448 // as required, by determining their vtable index, setting
1449 // method->index, and finally setting the class's vtable_method_count.
1450 // Must be called with the lock for KLASS held.
1452 _Jv_Linker::layout_vtable_methods (jclass klass
)
1454 if (klass
->vtable
!= NULL
|| klass
->isInterface()
1455 || klass
->vtable_method_count
!= -1)
1458 jclass superclass
= klass
->getSuperclass();
1460 if (superclass
!= NULL
&& superclass
->vtable_method_count
== -1)
1462 JvSynchronize
sync (superclass
);
1463 layout_vtable_methods (superclass
);
1466 int index
= (superclass
== NULL
? 0 : superclass
->vtable_method_count
);
1468 for (int i
= 0; i
< klass
->method_count
; ++i
)
1470 _Jv_Method
*meth
= &klass
->methods
[i
];
1471 _Jv_Method
*super_meth
= NULL
;
1473 if (! _Jv_isVirtualMethod (meth
))
1476 if (superclass
!= NULL
)
1479 super_meth
= _Jv_LookupDeclaredMethod (superclass
, meth
->name
,
1480 meth
->signature
, &declarer
);
1481 // See if this method actually overrides the other method
1485 if (! _Jv_isVirtualMethod (super_meth
)
1486 || ! _Jv_CheckAccess (klass
, declarer
,
1487 super_meth
->accflags
))
1489 else if ((super_meth
->accflags
1490 & java::lang::reflect::Modifier::FINAL
) != 0)
1492 using namespace java::lang
;
1493 StringBuffer
*sb
= new StringBuffer();
1494 sb
->append(JvNewStringLatin1("method "));
1495 sb
->append(_Jv_GetMethodString(klass
, meth
));
1496 sb
->append(JvNewStringLatin1(" overrides final method "));
1497 sb
->append(_Jv_GetMethodString(declarer
, super_meth
));
1498 throw new VerifyError(sb
->toString());
1504 meth
->index
= super_meth
->index
;
1506 meth
->index
= index
++;
1509 klass
->vtable_method_count
= index
;
1512 // Set entries in VTABLE for virtual methods declared in KLASS.
1514 _Jv_Linker::set_vtable_entries (jclass klass
, _Jv_VTable
*vtable
)
1516 for (int i
= klass
->method_count
- 1; i
>= 0; i
--)
1518 using namespace java::lang::reflect
;
1520 _Jv_Method
*meth
= &klass
->methods
[i
];
1521 if (meth
->index
== (_Jv_ushort
) -1)
1523 if ((meth
->accflags
& Modifier::ABSTRACT
))
1524 // FIXME: it might be nice to have a libffi trampoline here,
1525 // so we could pass in the method name and other information.
1526 vtable
->set_method(meth
->index
,
1527 (void *) &_Jv_ThrowAbstractMethodError
);
1529 vtable
->set_method(meth
->index
, meth
->ncode
);
1533 // Allocate and lay out the virtual method table for KLASS. This will
1534 // also cause vtables to be generated for any non-abstract
1535 // superclasses, and virtual method layout to occur for any abstract
1536 // superclasses. Must be called with monitor lock for KLASS held.
1538 _Jv_Linker::make_vtable (jclass klass
)
1540 using namespace java::lang::reflect
;
1542 // If the vtable exists, or for interface classes, do nothing. All
1543 // other classes, including abstract classes, need a vtable.
1544 if (klass
->vtable
!= NULL
|| klass
->isInterface())
1547 // Ensure all the `ncode' entries are set.
1548 klass
->engine
->create_ncode(klass
);
1550 // Class must be laid out before we can create a vtable.
1551 if (klass
->vtable_method_count
== -1)
1552 layout_vtable_methods (klass
);
1554 // Allocate the new vtable.
1555 _Jv_VTable
*vtable
= _Jv_VTable::new_vtable (klass
->vtable_method_count
);
1556 klass
->vtable
= vtable
;
1558 // Copy the vtable of the closest superclass.
1559 jclass superclass
= klass
->superclass
;
1561 JvSynchronize
sync (superclass
);
1562 make_vtable (superclass
);
1564 for (int i
= 0; i
< superclass
->vtable_method_count
; ++i
)
1565 vtable
->set_method (i
, superclass
->vtable
->get_method (i
));
1567 // Set the class pointer and GC descriptor.
1568 vtable
->clas
= klass
;
1569 vtable
->gc_descr
= _Jv_BuildGCDescr (klass
);
1571 // For each virtual declared in klass, set new vtable entry or
1572 // override an old one.
1573 set_vtable_entries (klass
, vtable
);
1575 // Note that we don't check for abstract methods here. We used to,
1576 // but there is a JVMS clarification that indicates that a check
1577 // here would be too eager. And, a simple test case confirms this.
1580 // Lay out the class, allocating space for static fields and computing
1581 // offsets of instance fields. The class lock must be held by the
1584 _Jv_Linker::ensure_fields_laid_out (jclass klass
)
1586 if (klass
->size_in_bytes
!= -1)
1589 // Compute the alignment for this type by searching through the
1590 // superclasses and finding the maximum required alignment. We
1591 // could consider caching this in the Class.
1592 int max_align
= __alignof__ (java::lang::Object
);
1593 jclass super
= klass
->getSuperclass();
1594 while (super
!= NULL
)
1596 // Ensure that our super has its super installed before
1598 wait_for_state(super
, JV_STATE_LOADING
);
1599 ensure_fields_laid_out(super
);
1600 int num
= JvNumInstanceFields (super
);
1601 _Jv_Field
*field
= JvGetFirstInstanceField (super
);
1604 int field_align
= get_alignment_from_class (field
->type
);
1605 if (field_align
> max_align
)
1606 max_align
= field_align
;
1610 super
= super
->getSuperclass();
1614 // This is the size of the 'static' non-reference fields.
1615 int non_reference_size
= 0;
1616 // This is the size of the 'static' reference fields. We count
1617 // these separately to make it simpler for the GC to scan them.
1618 int reference_size
= 0;
1620 // Although java.lang.Object is never interpreted, an interface can
1621 // have a null superclass. Note that we have to lay out an
1622 // interface because it might have static fields.
1623 if (klass
->superclass
)
1624 instance_size
= klass
->superclass
->size();
1626 instance_size
= java::lang::Object::class$
.size();
1628 klass
->engine
->allocate_field_initializers (klass
);
1630 for (int i
= 0; i
< klass
->field_count
; i
++)
1635 _Jv_Field
*field
= &klass
->fields
[i
];
1637 if (! field
->isRef ())
1639 // It is safe to resolve the field here, since it's a
1640 // primitive class, which does not cause loading to happen.
1641 resolve_field (field
, klass
->loader
);
1642 field_size
= field
->type
->size ();
1643 field_align
= get_alignment_from_class (field
->type
);
1647 field_size
= sizeof (jobject
);
1648 field_align
= __alignof__ (jobject
);
1651 field
->bsize
= field_size
;
1653 if ((field
->flags
& java::lang::reflect::Modifier::STATIC
))
1655 if (field
->u
.addr
== NULL
)
1657 // This computes an offset into a region we'll allocate
1658 // shortly, and then adds this offset to the start
1662 reference_size
= ROUND (reference_size
, field_align
);
1663 field
->u
.boffset
= reference_size
;
1664 reference_size
+= field_size
;
1668 non_reference_size
= ROUND (non_reference_size
, field_align
);
1669 field
->u
.boffset
= non_reference_size
;
1670 non_reference_size
+= field_size
;
1676 instance_size
= ROUND (instance_size
, field_align
);
1677 field
->u
.boffset
= instance_size
;
1678 instance_size
+= field_size
;
1679 if (field_align
> max_align
)
1680 max_align
= field_align
;
1684 if (reference_size
!= 0 || non_reference_size
!= 0)
1685 klass
->engine
->allocate_static_fields (klass
, reference_size
,
1686 non_reference_size
);
1688 // Set the instance size for the class. Note that first we round it
1689 // to the alignment required for this object; this keeps us in sync
1690 // with our current ABI.
1691 instance_size
= ROUND (instance_size
, max_align
);
1692 klass
->size_in_bytes
= instance_size
;
1695 // This takes the class to state JV_STATE_LINKED. The class lock must
1696 // be held when calling this.
1698 _Jv_Linker::ensure_class_linked (jclass klass
)
1700 if (klass
->state
>= JV_STATE_LINKED
)
1703 int state
= klass
->state
;
1706 // Short-circuit, so that mutually dependent classes are ok.
1707 klass
->state
= JV_STATE_LINKED
;
1709 _Jv_Constants
*pool
= &klass
->constants
;
1711 // Compiled classes require that their class constants be
1712 // resolved here. However, interpreted classes need their
1713 // constants to be resolved lazily. If we resolve an
1714 // interpreted class' constants eagerly, we can end up with
1715 // spurious IllegalAccessErrors when the constant pool contains
1716 // a reference to a class we can't access. This can validly
1717 // occur in an obscure case involving the InnerClasses
1719 if (! _Jv_IsInterpretedClass (klass
))
1721 // Resolve class constants first, since other constant pool
1722 // entries may rely on these.
1723 for (int index
= 1; index
< pool
->size
; ++index
)
1725 if (pool
->tags
[index
] == JV_CONSTANT_Class
)
1726 // Lazily resolve the entries.
1727 resolve_pool_entry (klass
, index
, true);
1731 // Resolve the remaining constant pool entries.
1732 for (int index
= 1; index
< pool
->size
; ++index
)
1734 if (pool
->tags
[index
] == JV_CONSTANT_String
)
1738 str
= _Jv_NewStringUtf8Const (pool
->data
[index
].utf8
);
1739 pool
->data
[index
].o
= str
;
1740 pool
->tags
[index
] |= JV_CONSTANT_ResolvedFlag
;
1744 if (klass
->engine
->need_resolve_string_fields())
1746 jfieldID f
= JvGetFirstStaticField (klass
);
1747 for (int n
= JvNumStaticFields (klass
); n
> 0; --n
)
1749 int mod
= f
->getModifiers ();
1750 // If we have a static String field with a non-null initial
1751 // value, we know it points to a Utf8Const.
1753 // Finds out whether we have to initialize a String without the
1754 // need to resolve the field.
1755 if ((f
->isResolved()
1756 ? (f
->type
== &java::lang::String::class$
)
1757 : _Jv_equalUtf8Classnames((_Jv_Utf8Const
*) f
->type
,
1758 java::lang::String::class$
.name
))
1759 && (mod
& java::lang::reflect::Modifier::STATIC
) != 0)
1761 jstring
*strp
= (jstring
*) f
->u
.addr
;
1763 *strp
= _Jv_NewStringUtf8Const ((_Jv_Utf8Const
*) *strp
);
1765 f
= f
->getNextField ();
1769 klass
->notifyAll ();
1771 _Jv_PushClass (klass
);
1773 catch (java::lang::Throwable
*t
)
1775 klass
->state
= state
;
1780 // This ensures that symbolic superclass and superinterface references
1781 // are resolved for the indicated class. This must be called with the
1784 _Jv_Linker::ensure_supers_installed (jclass klass
)
1786 resolve_class_ref (klass
, &klass
->superclass
);
1787 // An interface won't have a superclass.
1788 if (klass
->superclass
)
1789 wait_for_state (klass
->superclass
, JV_STATE_LOADING
);
1791 for (int i
= 0; i
< klass
->interface_count
; ++i
)
1793 resolve_class_ref (klass
, &klass
->interfaces
[i
]);
1794 wait_for_state (klass
->interfaces
[i
], JV_STATE_LOADING
);
1798 // This adds missing `Miranda methods' to a class.
1800 _Jv_Linker::add_miranda_methods (jclass base
, jclass iface_class
)
1802 // Note that at this point, all our supers, and the supers of all
1803 // our superclasses and superinterfaces, will have been installed.
1805 for (int i
= 0; i
< iface_class
->interface_count
; ++i
)
1807 jclass interface
= iface_class
->interfaces
[i
];
1809 for (int j
= 0; j
< interface
->method_count
; ++j
)
1811 _Jv_Method
*meth
= &interface
->methods
[j
];
1812 // Don't bother with <clinit>.
1813 if (meth
->name
->first() == '<')
1815 _Jv_Method
*new_meth
= _Jv_LookupDeclaredMethod (base
, meth
->name
,
1819 // We assume that such methods are very unlikely, so we
1820 // just reallocate the method array each time one is
1821 // found. This greatly simplifies the searching --
1822 // otherwise we have to make sure that each such method
1823 // found is really unique among all superinterfaces.
1824 int new_count
= base
->method_count
+ 1;
1826 = (_Jv_Method
*) _Jv_AllocRawObj (sizeof (_Jv_Method
)
1828 memcpy (new_m
, base
->methods
,
1829 sizeof (_Jv_Method
) * base
->method_count
);
1832 new_m
[base
->method_count
] = *meth
;
1833 new_m
[base
->method_count
].index
= (_Jv_ushort
) -1;
1834 new_m
[base
->method_count
].accflags
1835 |= java::lang::reflect::Modifier::INVISIBLE
;
1837 base
->methods
= new_m
;
1838 base
->method_count
= new_count
;
1842 wait_for_state (interface
, JV_STATE_LOADED
);
1843 add_miranda_methods (base
, interface
);
1847 // This ensures that the class' method table is "complete". This must
1848 // be called with the class lock held.
1850 _Jv_Linker::ensure_method_table_complete (jclass klass
)
1852 if (klass
->vtable
!= NULL
)
1855 // We need our superclass to have its own Miranda methods installed.
1856 if (! klass
->isInterface())
1857 wait_for_state (klass
->getSuperclass (), JV_STATE_LOADED
);
1859 // A class might have so-called "Miranda methods". This is a method
1860 // that is declared in an interface and not re-declared in an
1861 // abstract class. Some compilers don't emit declarations for such
1862 // methods in the class; this will give us problems since we expect
1863 // a declaration for any method requiring a vtable entry. We handle
1864 // this here by searching for such methods and constructing new
1865 // internal declarations for them. Note that we do this
1866 // unconditionally, and not just for abstract classes, to correctly
1867 // account for cases where a class is modified to be concrete and
1868 // still incorrectly inherits an abstract method.
1869 int pre_count
= klass
->method_count
;
1870 add_miranda_methods (klass
, klass
);
1872 // Let the execution engine know that we've added methods.
1873 if (klass
->method_count
!= pre_count
)
1874 klass
->engine
->post_miranda_hook(klass
);
1877 // Verify a class. Must be called with class lock held.
1879 _Jv_Linker::verify_class (jclass klass
)
1881 klass
->engine
->verify(klass
);
1884 // Check the assertions contained in the type assertion table for KLASS.
1885 // This is the equivilent of bytecode verification for native, BC-ABI code.
1887 _Jv_Linker::verify_type_assertions (jclass klass
)
1890 fprintf (stderr
, "Evaluating type assertions for %s:\n",
1891 klass
->name
->chars());
1893 if (klass
->assertion_table
== NULL
)
1896 for (int i
= 0;; i
++)
1898 int assertion_code
= klass
->assertion_table
[i
].assertion_code
;
1899 _Jv_Utf8Const
*op1
= klass
->assertion_table
[i
].op1
;
1900 _Jv_Utf8Const
*op2
= klass
->assertion_table
[i
].op2
;
1902 if (assertion_code
== JV_ASSERT_END_OF_TABLE
)
1904 else if (assertion_code
== JV_ASSERT_TYPES_COMPATIBLE
)
1908 fprintf (stderr
, " code=%i, operand A=%s B=%s\n",
1909 assertion_code
, op1
->chars(), op2
->chars());
1912 // The operands are class signatures. op1 is the source,
1913 // op2 is the target.
1914 jclass cl1
= _Jv_FindClassFromSignature (op1
->chars(),
1915 klass
->getClassLoaderInternal());
1916 jclass cl2
= _Jv_FindClassFromSignature (op2
->chars(),
1917 klass
->getClassLoaderInternal());
1919 // If the class doesn't exist, ignore the assertion. An exception
1920 // will be thrown later if an attempt is made to actually
1921 // instantiate the class.
1922 if (cl1
== NULL
|| cl2
== NULL
)
1925 if (! _Jv_IsAssignableFromSlow (cl1
, cl2
))
1927 jstring s
= JvNewStringUTF ("Incompatible types: In class ");
1928 s
= s
->concat (klass
->getName());
1929 s
= s
->concat (JvNewStringUTF (": "));
1930 s
= s
->concat (cl1
->getName());
1931 s
= s
->concat (JvNewStringUTF (" is not assignable to "));
1932 s
= s
->concat (cl2
->getName());
1933 throw new java::lang::VerifyError (s
);
1936 else if (assertion_code
== JV_ASSERT_IS_INSTANTIABLE
)
1938 // TODO: Implement this.
1940 // Unknown assertion codes are ignored, for forwards-compatibility.
1945 _Jv_Linker::print_class_loaded (jclass klass
)
1947 char *codesource
= NULL
;
1948 if (klass
->protectionDomain
!= NULL
)
1950 java::security::CodeSource
*cs
1951 = klass
->protectionDomain
->getCodeSource();
1954 jstring css
= cs
->toString();
1955 int len
= JvGetStringUTFLength(css
);
1956 codesource
= (char *) _Jv_AllocBytes(len
+ 1);
1957 JvGetStringUTFRegion(css
, 0, css
->length(), codesource
);
1958 codesource
[len
] = '\0';
1961 if (codesource
== NULL
)
1962 codesource
= (char *) "<no code source>";
1965 if (_Jv_IsInterpretedClass (klass
))
1967 else if (_Jv_IsBinaryCompatibilityABI (klass
))
1968 abi
= "BC-compiled";
1970 abi
= "pre-compiled";
1972 fprintf (stderr
, "[Loaded (%s) %s from %s]\n", abi
, klass
->name
->chars(),
1976 // FIXME: mention invariants and stuff.
1978 _Jv_Linker::wait_for_state (jclass klass
, int state
)
1980 if (klass
->state
>= state
)
1983 java::lang::Thread
*self
= java::lang::Thread::currentThread();
1986 JvSynchronize
sync (klass
);
1988 // This is similar to the strategy for class initialization. If we
1989 // already hold the lock, just leave.
1990 while (klass
->state
<= state
1992 && klass
->thread
!= self
)
1995 java::lang::Thread
*save
= klass
->thread
;
1996 klass
->thread
= self
;
1998 // Allocate memory for static fields and constants.
1999 if (GC_base (klass
) && klass
->fields
&& ! GC_base (klass
->fields
))
2001 jsize count
= klass
->field_count
;
2005 = (_Jv_Field
*) _Jv_AllocRawObj (count
* sizeof (_Jv_Field
));
2006 memcpy ((void*)fields
,
2007 (void*)klass
->fields
,
2008 count
* sizeof (_Jv_Field
));
2009 klass
->fields
= fields
;
2013 // Print some debugging info if requested. Interpreted classes are
2014 // handled in defineclass, so we only need to handle the two
2015 // pre-compiled cases here.
2016 if ((klass
->state
== JV_STATE_COMPILED
2017 || klass
->state
== JV_STATE_PRELOADING
)
2018 && ! _Jv_IsInterpretedClass (klass
))
2020 if (gcj::verbose_class_flag
)
2021 print_class_loaded (klass
);
2022 ++gcj::loadedClasses
;
2027 if (state
>= JV_STATE_LOADING
&& klass
->state
< JV_STATE_LOADING
)
2029 ensure_supers_installed (klass
);
2030 klass
->set_state(JV_STATE_LOADING
);
2033 if (state
>= JV_STATE_LOADED
&& klass
->state
< JV_STATE_LOADED
)
2035 ensure_method_table_complete (klass
);
2036 klass
->set_state(JV_STATE_LOADED
);
2039 if (state
>= JV_STATE_PREPARED
&& klass
->state
< JV_STATE_PREPARED
)
2041 ensure_fields_laid_out (klass
);
2042 make_vtable (klass
);
2043 layout_interface_methods (klass
);
2044 prepare_constant_time_tables (klass
);
2045 klass
->set_state(JV_STATE_PREPARED
);
2048 if (state
>= JV_STATE_LINKED
&& klass
->state
< JV_STATE_LINKED
)
2050 if (gcj::verifyClasses
)
2051 verify_class (klass
);
2053 ensure_class_linked (klass
);
2054 link_exception_table (klass
);
2055 link_symbol_table (klass
);
2056 klass
->set_state(JV_STATE_LINKED
);
2059 catch (java::lang::Throwable
*exc
)
2061 klass
->thread
= save
;
2062 klass
->set_state(JV_STATE_ERROR
);
2066 klass
->thread
= save
;
2068 if (klass
->state
== JV_STATE_ERROR
)
2069 throw new java::lang::LinkageError
;
2072 if (__builtin_expect (klass
->state
== JV_STATE_LINKED
, false)
2073 && state
>= JV_STATE_LINKED
2074 && JVMTI_REQUESTED_EVENT (ClassPrepare
))
2076 JNIEnv
*jni_env
= _Jv_GetCurrentJNIEnv ();
2077 _Jv_JVMTI_PostEvent (JVMTI_EVENT_CLASS_PREPARE
, self
, jni_env
,