1 // link.cc - Code for linking and resolving classes and pool entries.
3 /* Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006 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>
36 #include <java/lang/Class.h>
37 #include <java/lang/String.h>
38 #include <java/lang/StringBuffer.h>
39 #include <java/lang/Thread.h>
40 #include <java/lang/InternalError.h>
41 #include <java/lang/VirtualMachineError.h>
42 #include <java/lang/VerifyError.h>
43 #include <java/lang/NoSuchFieldError.h>
44 #include <java/lang/NoSuchMethodError.h>
45 #include <java/lang/ClassFormatError.h>
46 #include <java/lang/IllegalAccessError.h>
47 #include <java/lang/InternalError.h>
48 #include <java/lang/AbstractMethodError.h>
49 #include <java/lang/NoClassDefFoundError.h>
50 #include <java/lang/IncompatibleClassChangeError.h>
51 #include <java/lang/VerifyError.h>
52 #include <java/lang/VMClassLoader.h>
53 #include <java/lang/reflect/Modifier.h>
54 #include <java/security/CodeSource.h>
65 #define ALIGNOF(TYPE) (offsetof (aligner<TYPE>, field))
67 // This returns the alignment of a type as it would appear in a
68 // structure. This can be different from the alignment of the type
69 // itself. For instance on x86 double is 8-aligned but struct{double}
72 _Jv_Linker::get_alignment_from_class (jclass klass
)
74 if (klass
== JvPrimClass (byte
))
75 return ALIGNOF (jbyte
);
76 else if (klass
== JvPrimClass (short))
77 return ALIGNOF (jshort
);
78 else if (klass
== JvPrimClass (int))
79 return ALIGNOF (jint
);
80 else if (klass
== JvPrimClass (long))
81 return ALIGNOF (jlong
);
82 else if (klass
== JvPrimClass (boolean
))
83 return ALIGNOF (jboolean
);
84 else if (klass
== JvPrimClass (char))
85 return ALIGNOF (jchar
);
86 else if (klass
== JvPrimClass (float))
87 return ALIGNOF (jfloat
);
88 else if (klass
== JvPrimClass (double))
89 return ALIGNOF (jdouble
);
91 return ALIGNOF (jobject
);
95 _Jv_Linker::resolve_field (_Jv_Field
*field
, java::lang::ClassLoader
*loader
)
97 if (! field
->isResolved ())
99 _Jv_Utf8Const
*sig
= (_Jv_Utf8Const
*) field
->type
;
100 jclass type
= _Jv_FindClassFromSignature (sig
->chars(), loader
);
102 throw new java::lang::NoClassDefFoundError(field
->name
->toString());
104 field
->flags
&= ~_Jv_FIELD_UNRESOLVED_FLAG
;
108 // A helper for find_field that knows how to recursively search
109 // superclasses and interfaces.
111 _Jv_Linker::find_field_helper (jclass search
, _Jv_Utf8Const
*name
,
112 _Jv_Utf8Const
*type_name
, jclass type
,
117 // From 5.4.3.2. First search class itself.
118 for (int i
= 0; i
< search
->field_count
; ++i
)
120 _Jv_Field
*field
= &search
->fields
[i
];
121 if (! _Jv_equalUtf8Consts (field
->name
, name
))
124 // Checks for the odd situation where we were able to retrieve the
125 // field's class from signature but the resolution of the field itself
126 // failed which means a different class was resolved.
131 resolve_field (field
, search
->loader
);
133 catch (java::lang::Throwable
*exc
)
135 java::lang::LinkageError
*le
= new java::lang::LinkageError
137 ("field type mismatch with different loaders"));
145 // Note that we compare type names and not types. This is
146 // bizarre, but we do it because we want to find a field
147 // (and terminate the search) if it has the correct
148 // descriptor -- but then later reject it if the class
149 // loader check results in different classes. We can't just
150 // pass in the descriptor and check that way, because when
151 // the field is already resolved there is no easy way to
152 // find its descriptor again.
153 if ((field
->isResolved ()
154 ? _Jv_equalUtf8Classnames (type_name
, field
->type
->name
)
155 : _Jv_equalUtf8Classnames (type_name
,
156 (_Jv_Utf8Const
*) field
->type
)))
163 // Next search direct interfaces.
164 for (int i
= 0; i
< search
->interface_count
; ++i
)
166 _Jv_Field
*result
= find_field_helper (search
->interfaces
[i
], name
,
167 type_name
, type
, declarer
);
172 // Now search superclass.
173 search
= search
->superclass
;
180 _Jv_Linker::has_field_p (jclass search
, _Jv_Utf8Const
*field_name
)
182 for (int i
= 0; i
< search
->field_count
; ++i
)
184 _Jv_Field
*field
= &search
->fields
[i
];
185 if (_Jv_equalUtf8Consts (field
->name
, field_name
))
192 // KLASS is the class that is requesting the field.
193 // OWNER is the class in which the field should be found.
194 // FIELD_TYPE_NAME is the type descriptor for the field.
195 // Fill FOUND_CLASS with the address of the class in which the field
196 // is actually declared.
197 // This function does the class loader type checks, and
198 // also access checks. Returns the field, or throws an
199 // exception on error.
201 _Jv_Linker::find_field (jclass klass
, jclass owner
,
203 _Jv_Utf8Const
*field_name
,
204 _Jv_Utf8Const
*field_type_name
)
206 // FIXME: this allocates a _Jv_Utf8Const each time. We should make
208 // Note: This call will resolve the primitive type names ("Z", "B", ...) to
209 // their Java counterparts ("boolean", "byte", ...) if accessed via
210 // field_type->name later. Using these variants of the type name is in turn
211 // important for the find_field_helper function. However if the class
212 // resolution failed then we can only use the already given type name.
214 = _Jv_FindClassFromSignatureNoException (field_type_name
->chars(),
218 = find_field_helper (owner
, field_name
,
222 field_type
, found_class
);
226 java::lang::StringBuffer
*sb
= new java::lang::StringBuffer();
227 sb
->append(JvNewStringLatin1("field "));
228 sb
->append(owner
->getName());
229 sb
->append(JvNewStringLatin1("."));
230 sb
->append(_Jv_NewStringUTF(field_name
->chars()));
231 sb
->append(JvNewStringLatin1(" was not found."));
232 throw new java::lang::NoSuchFieldError (sb
->toString());
235 // Accept it when the field's class could not be resolved.
236 if (field_type
== NULL
)
237 // Silently ignore that we were not able to retrieve the type to make it
238 // possible to run code which does not access this field.
241 if (_Jv_CheckAccess (klass
, *found_class
, the_field
->flags
))
243 // Note that the field returned by find_field_helper is always
244 // resolved. There's no point checking class loaders here,
245 // since we already did the work to look up all the types.
246 // FIXME: being lazy here would be nice.
247 if (the_field
->type
!= field_type
)
248 throw new java::lang::LinkageError
250 ("field type mismatch with different loaders"));
254 java::lang::StringBuffer
*sb
255 = new java::lang::StringBuffer ();
256 sb
->append(klass
->getName());
257 sb
->append(JvNewStringLatin1(": "));
258 sb
->append((*found_class
)->getName());
259 sb
->append(JvNewStringLatin1("."));
260 sb
->append(_Jv_NewStringUtf8Const (field_name
));
261 throw new java::lang::IllegalAccessError(sb
->toString());
268 _Jv_Linker::resolve_method_entry (jclass klass
, jclass
&found_class
,
269 int class_index
, int name_and_type_index
,
270 bool init
, bool is_iface
)
272 _Jv_Constants
*pool
= &klass
->constants
;
273 jclass owner
= resolve_pool_entry (klass
, class_index
).clazz
;
275 if (init
&& owner
!= klass
)
276 _Jv_InitClass (owner
);
278 _Jv_ushort name_index
, type_index
;
279 _Jv_loadIndexes (&pool
->data
[name_and_type_index
],
283 _Jv_Utf8Const
*method_name
= pool
->data
[name_index
].utf8
;
284 _Jv_Utf8Const
*method_signature
= pool
->data
[type_index
].utf8
;
286 _Jv_Method
*the_method
= 0;
289 // We're going to cache a pointer to the _Jv_Method object
290 // when we find it. So, to ensure this doesn't get moved from
291 // beneath us, we first put all the needed Miranda methods
292 // into the target class.
293 wait_for_state (klass
, JV_STATE_LOADED
);
295 // First search the class itself.
296 the_method
= search_method_in_class (owner
, klass
,
297 method_name
, method_signature
);
302 goto end_of_method_search
;
305 // If we are resolving an interface method, search the
306 // interface's superinterfaces (A superinterface is not an
307 // interface's superclass - a superinterface is implemented by
314 ifaces
.list
= (jclass
*) _Jv_Malloc (ifaces
.len
315 * sizeof (jclass
*));
317 get_interfaces (owner
, &ifaces
);
319 for (int i
= 0; i
< ifaces
.count
; i
++)
321 jclass cls
= ifaces
.list
[i
];
322 the_method
= search_method_in_class (cls
, klass
, method_name
,
331 _Jv_Free (ifaces
.list
);
334 goto end_of_method_search
;
337 // Finally, search superclasses.
338 the_method
= (search_method_in_superclasses
339 (owner
->getSuperclass (), klass
, method_name
,
340 method_signature
, &found_class
));
343 end_of_method_search
:
345 // FIXME: if (cls->loader != klass->loader), then we
346 // must actually check that the types of arguments
347 // correspond. That is, for each argument type, and
348 // the return type, doing _Jv_FindClassFromSignature
349 // with either loader should produce the same result,
350 // i.e., exactly the same jclass object. JVMS 5.4.3.3
354 java::lang::StringBuffer
*sb
= new java::lang::StringBuffer();
355 sb
->append(JvNewStringLatin1("method "));
356 sb
->append(owner
->getName());
357 sb
->append(JvNewStringLatin1("."));
358 sb
->append(_Jv_NewStringUTF(method_name
->chars()));
359 sb
->append(JvNewStringLatin1(" with signature "));
360 sb
->append(_Jv_NewStringUTF(method_signature
->chars()));
361 sb
->append(JvNewStringLatin1(" was not found."));
362 throw new java::lang::NoSuchMethodError (sb
->toString());
369 _Jv_Linker::resolve_pool_entry (jclass klass
, int index
, bool lazy
)
371 using namespace java::lang::reflect
;
373 if (GC_base (klass
) && klass
->constants
.data
374 && ! GC_base (klass
->constants
.data
))
376 jsize count
= klass
->constants
.size
;
380 = (_Jv_word
*) _Jv_AllocRawObj (count
* sizeof (_Jv_word
));
381 memcpy ((void*)constants
,
382 (void*)klass
->constants
.data
,
383 count
* sizeof (_Jv_word
));
384 klass
->constants
.data
= constants
;
388 _Jv_Constants
*pool
= &klass
->constants
;
390 if ((pool
->tags
[index
] & JV_CONSTANT_ResolvedFlag
) != 0)
391 return pool
->data
[index
];
393 switch (pool
->tags
[index
] & ~JV_CONSTANT_LazyFlag
)
395 case JV_CONSTANT_Class
:
397 _Jv_Utf8Const
*name
= pool
->data
[index
].utf8
;
400 if (name
->first() == '[')
401 found
= _Jv_FindClassFromSignatureNoException (name
->chars(),
404 found
= _Jv_FindClassNoException (name
, klass
->loader
);
406 // If the class could not be loaded a phantom class is created. Any
407 // function that deals with such a class but cannot do something useful
408 // with it should just throw a NoClassDefFoundError with the class'
413 found
= _Jv_NewClass(name
, NULL
, NULL
);
414 found
->state
= JV_STATE_PHANTOM
;
415 pool
->tags
[index
] |= JV_CONSTANT_ResolvedFlag
;
416 pool
->data
[index
].clazz
= found
;
420 throw new java::lang::NoClassDefFoundError (name
->toString());
422 // Check accessibility, but first strip array types as
423 // _Jv_ClassNameSamePackage can't handle arrays.
426 check
&& check
->isArray();
427 check
= check
->getComponentType())
429 if ((found
->accflags
& Modifier::PUBLIC
) == Modifier::PUBLIC
430 || (_Jv_ClassNameSamePackage (check
->name
,
433 pool
->data
[index
].clazz
= found
;
434 pool
->tags
[index
] |= JV_CONSTANT_ResolvedFlag
;
438 java::lang::StringBuffer
*sb
= new java::lang::StringBuffer ();
439 sb
->append(klass
->getName());
440 sb
->append(JvNewStringLatin1(" can't access class "));
441 sb
->append(found
->getName());
442 throw new java::lang::IllegalAccessError(sb
->toString());
447 case JV_CONSTANT_String
:
450 str
= _Jv_NewStringUtf8Const (pool
->data
[index
].utf8
);
451 pool
->data
[index
].o
= str
;
452 pool
->tags
[index
] |= JV_CONSTANT_ResolvedFlag
;
456 case JV_CONSTANT_Fieldref
:
458 _Jv_ushort class_index
, name_and_type_index
;
459 _Jv_loadIndexes (&pool
->data
[index
],
461 name_and_type_index
);
462 jclass owner
= (resolve_pool_entry (klass
, class_index
, true)).clazz
;
464 // If a phantom class was resolved our field reference is
465 // unusable because of the missing class.
466 if (owner
->state
== JV_STATE_PHANTOM
)
467 throw new java::lang::NoClassDefFoundError(owner
->getName());
469 // We don't initialize 'owner', but we do make sure that its
471 wait_for_state (owner
, JV_STATE_PREPARED
);
473 _Jv_ushort name_index
, type_index
;
474 _Jv_loadIndexes (&pool
->data
[name_and_type_index
],
478 _Jv_Utf8Const
*field_name
= pool
->data
[name_index
].utf8
;
479 _Jv_Utf8Const
*field_type_name
= pool
->data
[type_index
].utf8
;
481 jclass found_class
= 0;
482 _Jv_Field
*the_field
= find_field (klass
, owner
,
486 // Initialize the field's declaring class, not its qualifying
488 _Jv_InitClass (found_class
);
489 pool
->data
[index
].field
= the_field
;
490 pool
->tags
[index
] |= JV_CONSTANT_ResolvedFlag
;
494 case JV_CONSTANT_Methodref
:
495 case JV_CONSTANT_InterfaceMethodref
:
497 _Jv_ushort class_index
, name_and_type_index
;
498 _Jv_loadIndexes (&pool
->data
[index
],
500 name_and_type_index
);
502 _Jv_Method
*the_method
;
504 the_method
= resolve_method_entry (klass
, found_class
,
505 class_index
, name_and_type_index
,
507 pool
->tags
[index
] == JV_CONSTANT_InterfaceMethodref
);
509 pool
->data
[index
].rmethod
510 = klass
->engine
->resolve_method(the_method
,
512 ((the_method
->accflags
513 & Modifier::STATIC
) != 0));
514 pool
->tags
[index
] |= JV_CONSTANT_ResolvedFlag
;
518 return pool
->data
[index
];
521 // This function is used to lazily locate superclasses and
522 // superinterfaces. This must be called with the class lock held.
524 _Jv_Linker::resolve_class_ref (jclass klass
, jclass
*classref
)
526 jclass ret
= *classref
;
528 // If superclass looks like a constant pool entry, resolve it now.
529 if (ret
&& (uaddr
) ret
< (uaddr
) klass
->constants
.size
)
531 if (klass
->state
< JV_STATE_LINKED
)
533 _Jv_Utf8Const
*name
= klass
->constants
.data
[(uaddr
) *classref
].utf8
;
534 ret
= _Jv_FindClass (name
, klass
->loader
);
537 throw new java::lang::NoClassDefFoundError (name
->toString());
541 ret
= klass
->constants
.data
[(uaddr
) classref
].clazz
;
546 // Find a method declared in the cls that is referenced from klass and
547 // perform access checks if CHECK_PERMS is true.
549 _Jv_Linker::search_method_in_class (jclass cls
, jclass klass
,
550 _Jv_Utf8Const
*method_name
,
551 _Jv_Utf8Const
*method_signature
,
554 using namespace java::lang::reflect
;
556 for (int i
= 0; i
< cls
->method_count
; i
++)
558 _Jv_Method
*method
= &cls
->methods
[i
];
559 if ( (!_Jv_equalUtf8Consts (method
->name
,
561 || (!_Jv_equalUtf8Consts (method
->signature
,
565 if (!check_perms
|| _Jv_CheckAccess (klass
, cls
, method
->accflags
))
569 java::lang::StringBuffer
*sb
= new java::lang::StringBuffer();
570 sb
->append(klass
->getName());
571 sb
->append(JvNewStringLatin1(": "));
572 sb
->append(cls
->getName());
573 sb
->append(JvNewStringLatin1("."));
574 sb
->append(_Jv_NewStringUTF(method_name
->chars()));
575 sb
->append(_Jv_NewStringUTF(method_signature
->chars()));
576 throw new java::lang::IllegalAccessError (sb
->toString());
582 // Like search_method_in_class, but work our way up the superclass
585 _Jv_Linker::search_method_in_superclasses (jclass cls
, jclass klass
,
586 _Jv_Utf8Const
*method_name
,
587 _Jv_Utf8Const
*method_signature
,
588 jclass
*found_class
, bool check_perms
)
590 _Jv_Method
*the_method
= NULL
;
592 for ( ; cls
!= 0; cls
= cls
->getSuperclass ())
594 the_method
= search_method_in_class (cls
, klass
, method_name
,
595 method_signature
, check_perms
);
607 #define INITIAL_IOFFSETS_LEN 4
608 #define INITIAL_IFACES_LEN 4
610 static _Jv_IDispatchTable null_idt
= {SHRT_MAX
, 0, {}};
612 // Generate tables for constant-time assignment testing and interface
613 // method lookup. This implements the technique described by Per Bothner
614 // <per@bothner.com> on the java-discuss mailing list on 1999-09-02:
615 // http://gcc.gnu.org/ml/java/1999-q3/msg00377.html
617 _Jv_Linker::prepare_constant_time_tables (jclass klass
)
619 if (klass
->isPrimitive () || klass
->isInterface ())
622 // Short-circuit in case we've been called already.
623 if ((klass
->idt
!= NULL
) || klass
->depth
!= 0)
626 // Calculate the class depth and ancestor table. The depth of a class
627 // is how many "extends" it is removed from Object. Thus the depth of
628 // java.lang.Object is 0, but the depth of java.io.FilterOutputStream
629 // is 2. Depth is defined for all regular and array classes, but not
630 // interfaces or primitive types.
632 jclass klass0
= klass
;
633 jboolean has_interfaces
= 0;
634 while (klass0
!= &java::lang::Object::class$
)
636 has_interfaces
+= klass0
->interface_count
;
637 klass0
= klass0
->superclass
;
641 // We do class member testing in constant time by using a small table
642 // of all the ancestor classes within each class. The first element is
643 // a pointer to the current class, and the rest are pointers to the
644 // classes ancestors, ordered from the current class down by decreasing
645 // depth. We do not include java.lang.Object in the table of ancestors,
646 // since it is redundant. Note that the classes pointed to by
647 // 'ancestors' will always be reachable by other paths.
649 klass
->ancestors
= (jclass
*) _Jv_AllocBytes (klass
->depth
652 for (int index
= 0; index
< klass
->depth
; index
++)
654 klass
->ancestors
[index
] = klass0
;
655 klass0
= klass0
->superclass
;
658 if ((klass
->accflags
& java::lang::reflect::Modifier::ABSTRACT
) != 0)
661 // Optimization: If class implements no interfaces, use a common
662 // predefined interface table.
665 klass
->idt
= &null_idt
;
671 ifaces
.len
= INITIAL_IFACES_LEN
;
672 ifaces
.list
= (jclass
*) _Jv_Malloc (ifaces
.len
* sizeof (jclass
*));
674 int itable_size
= get_interfaces (klass
, &ifaces
);
676 if (ifaces
.count
> 0)
678 // The classes pointed to by the itable will always be reachable
680 int idt_bytes
= sizeof (_Jv_IDispatchTable
) + (itable_size
682 klass
->idt
= (_Jv_IDispatchTable
*) _Jv_AllocBytes (idt_bytes
);
683 klass
->idt
->itable_length
= itable_size
;
685 jshort
*itable_offsets
=
686 (jshort
*) _Jv_Malloc (ifaces
.count
* sizeof (jshort
));
688 generate_itable (klass
, &ifaces
, itable_offsets
);
690 jshort cls_iindex
= find_iindex (ifaces
.list
, itable_offsets
,
693 for (int i
= 0; i
< ifaces
.count
; i
++)
695 ifaces
.list
[i
]->ioffsets
[cls_iindex
] = itable_offsets
[i
];
698 klass
->idt
->iindex
= cls_iindex
;
700 _Jv_Free (ifaces
.list
);
701 _Jv_Free (itable_offsets
);
705 klass
->idt
->iindex
= SHRT_MAX
;
709 // Return index of item in list, or -1 if item is not present.
711 _Jv_Linker::indexof (void *item
, void **list
, jshort list_len
)
713 for (int i
=0; i
< list_len
; i
++)
721 // Find all unique interfaces directly or indirectly implemented by klass.
722 // Returns the size of the interface dispatch table (itable) for klass, which
723 // is the number of unique interfaces plus the total number of methods that
724 // those interfaces declare. May extend ifaces if required.
726 _Jv_Linker::get_interfaces (jclass klass
, _Jv_ifaces
*ifaces
)
730 for (int i
= 0; i
< klass
->interface_count
; i
++)
732 jclass iface
= klass
->interfaces
[i
];
734 /* Make sure interface is linked. */
735 wait_for_state(iface
, JV_STATE_LINKED
);
737 if (indexof (iface
, (void **) ifaces
->list
, ifaces
->count
) == -1)
739 if (ifaces
->count
+ 1 >= ifaces
->len
)
741 /* Resize ifaces list */
742 ifaces
->len
= ifaces
->len
* 2;
744 = (jclass
*) _Jv_Realloc (ifaces
->list
,
745 ifaces
->len
* sizeof(jclass
));
747 ifaces
->list
[ifaces
->count
] = iface
;
750 result
+= get_interfaces (klass
->interfaces
[i
], ifaces
);
754 if (klass
->isInterface())
756 // We want to add 1 plus the number of interface methods here.
757 // But, we take special care to skip <clinit>.
759 for (int i
= 0; i
< klass
->method_count
; ++i
)
761 if (klass
->methods
[i
].name
->first() != '<')
765 else if (klass
->superclass
)
766 result
+= get_interfaces (klass
->superclass
, ifaces
);
770 // Fill out itable in klass, resolving method declarations in each ifaces.
771 // itable_offsets is filled out with the position of each iface in itable,
772 // such that itable[itable_offsets[n]] == ifaces.list[n].
774 _Jv_Linker::generate_itable (jclass klass
, _Jv_ifaces
*ifaces
,
775 jshort
*itable_offsets
)
777 void **itable
= klass
->idt
->itable
;
778 jshort itable_pos
= 0;
780 for (int i
= 0; i
< ifaces
->count
; i
++)
782 jclass iface
= ifaces
->list
[i
];
783 itable_offsets
[i
] = itable_pos
;
784 itable_pos
= append_partial_itable (klass
, iface
, itable
, itable_pos
);
786 /* Create ioffsets table for iface */
787 if (iface
->ioffsets
== NULL
)
789 // The first element of ioffsets is its length (itself included).
790 jshort
*ioffsets
= (jshort
*) _Jv_AllocBytes (INITIAL_IOFFSETS_LEN
792 ioffsets
[0] = INITIAL_IOFFSETS_LEN
;
793 for (int i
= 1; i
< INITIAL_IOFFSETS_LEN
; i
++)
796 iface
->ioffsets
= ioffsets
;
801 // Format method name for use in error messages.
803 _Jv_GetMethodString (jclass klass
, _Jv_Method
*meth
,
806 using namespace java::lang
;
807 StringBuffer
*buf
= new StringBuffer (klass
->name
->toString());
808 buf
->append (jchar ('.'));
809 buf
->append (meth
->name
->toString());
810 buf
->append ((jchar
) ' ');
811 buf
->append (meth
->signature
->toString());
814 buf
->append(JvNewStringLatin1(" in "));
815 buf
->append(derived
->name
->toString());
817 return buf
->toString();
821 _Jv_ThrowNoSuchMethodError ()
823 throw new java::lang::NoSuchMethodError
;
826 #if defined USE_LIBFFI && FFI_CLOSURES
827 // A function whose invocation is prepared using libffi. It gets called
828 // whenever a static method of a missing class is invoked. The data argument
829 // holds a reference to a String denoting the missing class.
830 // The prepared function call is stored in a class' atable.
832 _Jv_ThrowNoClassDefFoundErrorTrampoline(ffi_cif
*,
837 throw new java::lang::NoClassDefFoundError(
838 _Jv_NewStringUtf8Const((_Jv_Utf8Const
*) data
));
841 // A variant of the NoClassDefFoundError throwing method that can
842 // be used without libffi.
844 _Jv_ThrowNoClassDefFoundError()
846 throw new java::lang::NoClassDefFoundError();
850 // Throw a NoSuchFieldError. Called by compiler-generated code when
851 // an otable entry is zero. OTABLE_INDEX is the index in the caller's
852 // otable that refers to the missing field. This index may be used to
853 // print diagnostic information about the field.
855 _Jv_ThrowNoSuchFieldError (int /* otable_index */)
857 throw new java::lang::NoSuchFieldError
;
860 // This is put in empty vtable slots.
862 _Jv_ThrowAbstractMethodError ()
864 throw new java::lang::AbstractMethodError();
867 // Each superinterface of a class (i.e. each interface that the class
868 // directly or indirectly implements) has a corresponding "Partial
869 // Interface Dispatch Table" whose size is (number of methods + 1) words.
870 // The first word is a pointer to the interface (i.e. the java.lang.Class
871 // instance for that interface). The remaining words are pointers to the
872 // actual methods that implement the methods declared in the interface,
873 // in order of declaration.
875 // Append partial interface dispatch table for "iface" to "itable", at
876 // position itable_pos.
877 // Returns the offset at which the next partial ITable should be appended.
879 _Jv_Linker::append_partial_itable (jclass klass
, jclass iface
,
880 void **itable
, jshort pos
)
882 using namespace java::lang::reflect
;
884 itable
[pos
++] = (void *) iface
;
887 for (int j
=0; j
< iface
->method_count
; j
++)
889 // Skip '<clinit>' here.
890 if (iface
->methods
[j
].name
->first() == '<')
894 for (jclass cl
= klass
; cl
; cl
= cl
->getSuperclass())
896 meth
= _Jv_GetMethodLocal (cl
, iface
->methods
[j
].name
,
897 iface
->methods
[j
].signature
);
905 if ((meth
->accflags
& Modifier::STATIC
) != 0)
906 throw new java::lang::IncompatibleClassChangeError
907 (_Jv_GetMethodString (klass
, meth
));
908 if ((meth
->accflags
& Modifier::PUBLIC
) == 0)
909 throw new java::lang::IllegalAccessError
910 (_Jv_GetMethodString (klass
, meth
));
912 if ((meth
->accflags
& Modifier::ABSTRACT
) != 0)
913 itable
[pos
] = (void *) &_Jv_ThrowAbstractMethodError
;
915 itable
[pos
] = meth
->ncode
;
919 // The method doesn't exist in klass. Binary compatibility rules
920 // permit this, so we delay the error until runtime using a pointer
921 // to a method which throws an exception.
922 itable
[pos
] = (void *) _Jv_ThrowNoSuchMethodError
;
930 static _Jv_Mutex_t iindex_mutex
;
931 static bool iindex_mutex_initialized
= false;
933 // We need to find the correct offset in the Class Interface Dispatch
934 // Table for a given interface. Once we have that, invoking an interface
935 // method just requires combining the Method's index in the interface
936 // (known at compile time) to get the correct method. Doing a type test
937 // (cast or instanceof) is the same problem: Once we have a possible Partial
938 // Interface Dispatch Table, we just compare the first element to see if it
939 // matches the desired interface. So how can we find the correct offset?
940 // Our solution is to keep a vector of candiate offsets in each interface
941 // (ioffsets), and in each class we have an index (idt->iindex) used to
942 // select the correct offset from ioffsets.
944 // Calculate and return iindex for a new class.
945 // ifaces is a vector of num interfaces that the class implements.
946 // offsets[j] is the offset in the interface dispatch table for the
947 // interface corresponding to ifaces[j].
948 // May extend the interface ioffsets if required.
950 _Jv_Linker::find_iindex (jclass
*ifaces
, jshort
*offsets
, jshort num
)
955 // Acquire a global lock to prevent itable corruption in case of multiple
956 // classes that implement an intersecting set of interfaces being linked
957 // simultaneously. We can assume that the mutex will be initialized
959 if (! iindex_mutex_initialized
)
961 _Jv_MutexInit (&iindex_mutex
);
962 iindex_mutex_initialized
= true;
965 _Jv_MutexLock (&iindex_mutex
);
967 for (i
=1;; i
++) /* each potential position in ioffsets */
969 for (j
=0;; j
++) /* each iface */
973 if (i
>= ifaces
[j
]->ioffsets
[0])
975 int ioffset
= ifaces
[j
]->ioffsets
[i
];
976 /* We can potentially share this position with another class. */
977 if (ioffset
>= 0 && ioffset
!= offsets
[j
])
978 break; /* Nope. Try next i. */
982 for (j
= 0; j
< num
; j
++)
984 int len
= ifaces
[j
]->ioffsets
[0];
988 int newlen
= 2 * len
;
992 jshort
*old_ioffsets
= ifaces
[j
]->ioffsets
;
993 jshort
*new_ioffsets
= (jshort
*) _Jv_AllocBytes (newlen
995 memcpy (&new_ioffsets
[1], &old_ioffsets
[1],
996 (len
- 1) * sizeof (jshort
));
997 new_ioffsets
[0] = newlen
;
1000 new_ioffsets
[len
++] = -1;
1002 ifaces
[j
]->ioffsets
= new_ioffsets
;
1004 ifaces
[j
]->ioffsets
[i
] = offsets
[j
];
1007 _Jv_MutexUnlock (&iindex_mutex
);
1012 #if defined USE_LIBFFI && FFI_CLOSURES
1013 // We use a structure of this type to store the closure that
1014 // represents a missing method.
1015 struct method_closure
1017 // This field must come first, since the address of this field will
1018 // be the same as the address of the overall structure. This is due
1019 // to disabling interior pointers in the GC.
1020 ffi_closure closure
;
1022 ffi_type
*arg_types
[1];
1026 _Jv_Linker::create_error_method (_Jv_Utf8Const
*class_name
)
1028 method_closure
*closure
1029 = (method_closure
*) _Jv_AllocBytes(sizeof (method_closure
));
1031 closure
->arg_types
[0] = &ffi_type_void
;
1033 // Initializes the cif and the closure. If that worked the closure
1034 // is returned and can be used as a function pointer in a class'
1036 if ( ffi_prep_cif (&closure
->cif
,
1040 closure
->arg_types
) == FFI_OK
1041 && ffi_prep_closure (&closure
->closure
,
1043 _Jv_ThrowNoClassDefFoundErrorTrampoline
,
1044 class_name
) == FFI_OK
)
1045 return &closure
->closure
;
1048 java::lang::StringBuffer
*buffer
= new java::lang::StringBuffer();
1049 buffer
->append(JvNewStringLatin1("Error setting up FFI closure"
1050 " for static method of"
1051 " missing class: "));
1052 buffer
->append (_Jv_NewStringUtf8Const(class_name
));
1053 throw new java::lang::InternalError(buffer
->toString());
1058 _Jv_Linker::create_error_method (_Jv_Utf8Const
*)
1060 // Codepath for platforms which do not support (or want) libffi.
1061 // You have to accept that it is impossible to provide the name
1062 // of the missing class then.
1063 return (void *) _Jv_ThrowNoClassDefFoundError
;
1065 #endif // USE_LIBFFI && FFI_CLOSURES
1067 // Functions for indirect dispatch (symbolic virtual binding) support.
1069 // There are three tables, atable otable and itable. atable is an
1070 // array of addresses, and otable is an array of offsets, and these
1071 // are used for static and virtual members respectively. itable is an
1072 // array of pairs {address, index} where each address is a pointer to
1075 // {a,o,i}table_syms is an array of _Jv_MethodSymbols. Each such
1076 // symbol is a tuple of {classname, member name, signature}.
1078 // Set this to true to enable debugging of indirect dispatch tables/linking.
1079 static bool debug_link
= false;
1081 // link_symbol_table() scans these two arrays and fills in the
1082 // corresponding atable and otable with the addresses of static
1083 // members and the offsets of virtual members.
1085 // The offset (in bytes) for each resolved method or field is placed
1086 // at the corresponding position in the virtual method offset table
1089 // The same otable and atable may be shared by many classes.
1091 // This must be called while holding the class lock.
1094 _Jv_Linker::link_symbol_table (jclass klass
)
1097 _Jv_MethodSymbol sym
;
1098 if (klass
->otable
== NULL
1099 || klass
->otable
->state
!= 0)
1102 klass
->otable
->state
= 1;
1105 fprintf (stderr
, "Fixing up otable in %s:\n", klass
->name
->chars());
1107 (sym
= klass
->otable_syms
[index
]).class_name
!= NULL
;
1110 jclass target_class
= _Jv_FindClass (sym
.class_name
, klass
->loader
);
1111 _Jv_Method
*meth
= NULL
;
1113 _Jv_Utf8Const
*signature
= sym
.signature
;
1115 maybe_adjust_signature (signature
, special
);
1117 if (target_class
== NULL
)
1118 throw new java::lang::NoClassDefFoundError
1119 (_Jv_NewStringUTF (sym
.class_name
->chars()));
1121 // We're looking for a field or a method, and we can tell
1122 // which is needed by looking at the signature.
1123 if (signature
->first() == '(' && signature
->len() >= 2)
1125 // Looks like someone is trying to invoke an interface method
1126 if (target_class
->isInterface())
1128 using namespace java::lang
;
1129 StringBuffer
*sb
= new StringBuffer();
1130 sb
->append(JvNewStringLatin1("found interface "));
1131 sb
->append(target_class
->getName());
1132 sb
->append(JvNewStringLatin1(" when searching for a class"));
1133 throw new VerifyError(sb
->toString());
1136 // If the target class does not have a vtable_method_count yet,
1137 // then we can't tell the offsets for its methods, so we must lay
1139 wait_for_state(target_class
, JV_STATE_PREPARED
);
1143 meth
= (search_method_in_superclasses
1144 (target_class
, klass
, sym
.name
, signature
,
1145 NULL
, special
== 0));
1147 catch (::java::lang::IllegalAccessError
*e
)
1151 // Every class has a throwNoSuchMethodErrorIndex method that
1152 // it inherits from java.lang.Object. Find its vtable
1154 static int throwNoSuchMethodErrorIndex
;
1155 if (throwNoSuchMethodErrorIndex
== 0)
1158 = _Jv_makeUtf8Const ("throwNoSuchMethodError",
1159 strlen ("throwNoSuchMethodError"));
1161 = _Jv_LookupDeclaredMethod (&java::lang::Object::class$
,
1162 name
, gcj::void_signature
);
1163 throwNoSuchMethodErrorIndex
1164 = _Jv_VTable::idx_to_offset (meth
->index
);
1167 // If we don't find a nonstatic method, insert the
1168 // vtable index of Object.throwNoSuchMethodError().
1169 // This defers the missing method error until an attempt
1170 // is made to execute it.
1175 offset
= _Jv_VTable::idx_to_offset (meth
->index
);
1177 offset
= throwNoSuchMethodErrorIndex
;
1180 JvFail ("Bad method index");
1181 JvAssert (meth
->index
< target_class
->vtable_method_count
);
1183 klass
->otable
->offsets
[index
] = offset
;
1187 fprintf (stderr
, " offsets[%d] = %d (class %s@%p : %s(%s))\n",
1189 (int)klass
->otable
->offsets
[index
],
1190 (const char*)target_class
->name
->chars(),
1192 (const char*)sym
.name
->chars(),
1193 (const char*)signature
->chars());
1199 wait_for_state(target_class
, JV_STATE_PREPARED
);
1201 _Jv_Field
*the_field
= NULL
;
1204 the_field
= find_field (klass
, target_class
, &found_class
,
1205 sym
.name
, signature
);
1206 if ((the_field
->flags
& java::lang::reflect::Modifier::STATIC
))
1207 throw new java::lang::IncompatibleClassChangeError
;
1209 klass
->otable
->offsets
[index
] = the_field
->u
.boffset
;
1211 catch (java::lang::NoSuchFieldError
*err
)
1213 klass
->otable
->offsets
[index
] = 0;
1219 if (klass
->atable
== NULL
|| klass
->atable
->state
!= 0)
1222 klass
->atable
->state
= 1;
1225 (sym
= klass
->atable_syms
[index
]).class_name
!= NULL
;
1228 jclass target_class
=
1229 _Jv_FindClassNoException (sym
.class_name
, klass
->loader
);
1231 _Jv_Method
*meth
= NULL
;
1233 _Jv_Utf8Const
*signature
= sym
.signature
;
1235 maybe_adjust_signature (signature
, special
);
1237 // ??? Setting this pointer to null will at least get us a
1238 // NullPointerException
1239 klass
->atable
->addresses
[index
] = NULL
;
1241 // If the target class is missing we prepare a function call
1242 // that throws a NoClassDefFoundError and store the address of
1243 // that newly prepared method in the atable. The user can run
1244 // code in classes where the missing class is part of the
1245 // execution environment as long as it is never referenced.
1246 if (target_class
== NULL
)
1247 klass
->atable
->addresses
[index
] = create_error_method(sym
.class_name
);
1248 // We're looking for a static field or a static method, and we
1249 // can tell which is needed by looking at the signature.
1250 else if (signature
->first() == '(' && signature
->len() >= 2)
1252 // If the target class does not have a vtable_method_count yet,
1253 // then we can't tell the offsets for its methods, so we must lay
1255 wait_for_state (target_class
, JV_STATE_PREPARED
);
1257 // Interface methods cannot have bodies.
1258 if (target_class
->isInterface())
1260 using namespace java::lang
;
1261 StringBuffer
*sb
= new StringBuffer();
1262 sb
->append(JvNewStringLatin1("class "));
1263 sb
->append(target_class
->getName());
1264 sb
->append(JvNewStringLatin1(" is an interface: "
1266 throw new VerifyError(sb
->toString());
1271 meth
= (search_method_in_superclasses
1272 (target_class
, klass
, sym
.name
, signature
,
1273 NULL
, special
== 0));
1275 catch (::java::lang::IllegalAccessError
*e
)
1281 if (meth
->ncode
) // Maybe abstract?
1283 klass
->atable
->addresses
[index
] = meth
->ncode
;
1285 fprintf (stderr
, " addresses[%d] = %p (class %s@%p : %s(%s))\n",
1287 &klass
->atable
->addresses
[index
],
1288 (const char*)target_class
->name
->chars(),
1290 (const char*)sym
.name
->chars(),
1291 (const char*)signature
->chars());
1295 klass
->atable
->addresses
[index
]
1296 = create_error_method(sym
.class_name
);
1301 // Try fields only if the target class exists.
1302 if (target_class
!= NULL
)
1304 wait_for_state(target_class
, JV_STATE_PREPARED
);
1306 _Jv_Field
*the_field
= find_field (klass
, target_class
, &found_class
,
1307 sym
.name
, signature
);
1308 if ((the_field
->flags
& java::lang::reflect::Modifier::STATIC
))
1309 klass
->atable
->addresses
[index
] = the_field
->u
.addr
;
1311 throw new java::lang::IncompatibleClassChangeError
;
1316 if (klass
->itable
== NULL
1317 || klass
->itable
->state
!= 0)
1320 klass
->itable
->state
= 1;
1323 (sym
= klass
->itable_syms
[index
]).class_name
!= NULL
;
1326 jclass target_class
= _Jv_FindClass (sym
.class_name
, klass
->loader
);
1328 _Jv_Utf8Const
*signature
= sym
.signature
;
1330 maybe_adjust_signature (signature
, special
);
1335 wait_for_state(target_class
, JV_STATE_LOADED
);
1336 bool found
= _Jv_getInterfaceMethod (target_class
, cls
, i
,
1337 sym
.name
, signature
);
1341 klass
->itable
->addresses
[index
* 2] = cls
;
1342 klass
->itable
->addresses
[index
* 2 + 1] = (void *)(unsigned long) i
;
1345 fprintf (stderr
, " interfaces[%d] = %p (interface %s@%p : %s(%s))\n",
1347 klass
->itable
->addresses
[index
* 2],
1348 (const char*)cls
->name
->chars(),
1350 (const char*)sym
.name
->chars(),
1351 (const char*)signature
->chars());
1352 fprintf (stderr
, " [%d] = offset %d\n",
1354 (int)(unsigned long)klass
->itable
->addresses
[index
* 2 + 1]);
1359 throw new java::lang::IncompatibleClassChangeError
;
1364 // For each catch_record in the list of caught classes, fill in the
1367 _Jv_Linker::link_exception_table (jclass self
)
1369 struct _Jv_CatchClass
*catch_record
= self
->catch_classes
;
1370 if (!catch_record
|| catch_record
->classname
)
1373 while (catch_record
->classname
)
1378 = _Jv_FindClass (catch_record
->classname
,
1379 self
->getClassLoaderInternal ());
1380 *catch_record
->address
= target_class
;
1382 catch (::java::lang::Throwable
*t
)
1384 // FIXME: We need to do something better here.
1385 *catch_record
->address
= 0;
1389 self
->catch_classes
->classname
= (_Jv_Utf8Const
*)-1;
1392 // Set itable method indexes for members of interface IFACE.
1394 _Jv_Linker::layout_interface_methods (jclass iface
)
1396 if (! iface
->isInterface())
1399 // itable indexes start at 1.
1400 // FIXME: Static initalizers currently get a NULL placeholder entry in the
1401 // itable so they are also assigned an index here.
1402 for (int i
= 0; i
< iface
->method_count
; i
++)
1403 iface
->methods
[i
].index
= i
+ 1;
1406 // Prepare virtual method declarations in KLASS, and any superclasses
1407 // as required, by determining their vtable index, setting
1408 // method->index, and finally setting the class's vtable_method_count.
1409 // Must be called with the lock for KLASS held.
1411 _Jv_Linker::layout_vtable_methods (jclass klass
)
1413 if (klass
->vtable
!= NULL
|| klass
->isInterface()
1414 || klass
->vtable_method_count
!= -1)
1417 jclass superclass
= klass
->getSuperclass();
1419 if (superclass
!= NULL
&& superclass
->vtable_method_count
== -1)
1421 JvSynchronize
sync (superclass
);
1422 layout_vtable_methods (superclass
);
1425 int index
= (superclass
== NULL
? 0 : superclass
->vtable_method_count
);
1427 for (int i
= 0; i
< klass
->method_count
; ++i
)
1429 _Jv_Method
*meth
= &klass
->methods
[i
];
1430 _Jv_Method
*super_meth
= NULL
;
1432 if (! _Jv_isVirtualMethod (meth
))
1435 if (superclass
!= NULL
)
1438 super_meth
= _Jv_LookupDeclaredMethod (superclass
, meth
->name
,
1439 meth
->signature
, &declarer
);
1440 // See if this method actually overrides the other method
1444 if (! _Jv_isVirtualMethod (super_meth
)
1445 || ! _Jv_CheckAccess (klass
, declarer
,
1446 super_meth
->accflags
))
1448 else if ((super_meth
->accflags
1449 & java::lang::reflect::Modifier::FINAL
) != 0)
1451 using namespace java::lang
;
1452 StringBuffer
*sb
= new StringBuffer();
1453 sb
->append(JvNewStringLatin1("method "));
1454 sb
->append(_Jv_GetMethodString(klass
, meth
));
1455 sb
->append(JvNewStringLatin1(" overrides final method "));
1456 sb
->append(_Jv_GetMethodString(declarer
, super_meth
));
1457 throw new VerifyError(sb
->toString());
1463 meth
->index
= super_meth
->index
;
1465 meth
->index
= index
++;
1468 klass
->vtable_method_count
= index
;
1471 // Set entries in VTABLE for virtual methods declared in KLASS.
1473 _Jv_Linker::set_vtable_entries (jclass klass
, _Jv_VTable
*vtable
)
1475 for (int i
= klass
->method_count
- 1; i
>= 0; i
--)
1477 using namespace java::lang::reflect
;
1479 _Jv_Method
*meth
= &klass
->methods
[i
];
1480 if (meth
->index
== (_Jv_ushort
) -1)
1482 if ((meth
->accflags
& Modifier::ABSTRACT
))
1483 // FIXME: it might be nice to have a libffi trampoline here,
1484 // so we could pass in the method name and other information.
1485 vtable
->set_method(meth
->index
,
1486 (void *) &_Jv_ThrowAbstractMethodError
);
1488 vtable
->set_method(meth
->index
, meth
->ncode
);
1492 // Allocate and lay out the virtual method table for KLASS. This will
1493 // also cause vtables to be generated for any non-abstract
1494 // superclasses, and virtual method layout to occur for any abstract
1495 // superclasses. Must be called with monitor lock for KLASS held.
1497 _Jv_Linker::make_vtable (jclass klass
)
1499 using namespace java::lang::reflect
;
1501 // If the vtable exists, or for interface classes, do nothing. All
1502 // other classes, including abstract classes, need a vtable.
1503 if (klass
->vtable
!= NULL
|| klass
->isInterface())
1506 // Ensure all the `ncode' entries are set.
1507 klass
->engine
->create_ncode(klass
);
1509 // Class must be laid out before we can create a vtable.
1510 if (klass
->vtable_method_count
== -1)
1511 layout_vtable_methods (klass
);
1513 // Allocate the new vtable.
1514 _Jv_VTable
*vtable
= _Jv_VTable::new_vtable (klass
->vtable_method_count
);
1515 klass
->vtable
= vtable
;
1517 // Copy the vtable of the closest superclass.
1518 jclass superclass
= klass
->superclass
;
1520 JvSynchronize
sync (superclass
);
1521 make_vtable (superclass
);
1523 for (int i
= 0; i
< superclass
->vtable_method_count
; ++i
)
1524 vtable
->set_method (i
, superclass
->vtable
->get_method (i
));
1526 // Set the class pointer and GC descriptor.
1527 vtable
->clas
= klass
;
1528 vtable
->gc_descr
= _Jv_BuildGCDescr (klass
);
1530 // For each virtual declared in klass, set new vtable entry or
1531 // override an old one.
1532 set_vtable_entries (klass
, vtable
);
1534 // Note that we don't check for abstract methods here. We used to,
1535 // but there is a JVMS clarification that indicates that a check
1536 // here would be too eager. And, a simple test case confirms this.
1539 // Lay out the class, allocating space for static fields and computing
1540 // offsets of instance fields. The class lock must be held by the
1543 _Jv_Linker::ensure_fields_laid_out (jclass klass
)
1545 if (klass
->size_in_bytes
!= -1)
1548 // Compute the alignment for this type by searching through the
1549 // superclasses and finding the maximum required alignment. We
1550 // could consider caching this in the Class.
1551 int max_align
= __alignof__ (java::lang::Object
);
1552 jclass super
= klass
->getSuperclass();
1553 while (super
!= NULL
)
1555 // Ensure that our super has its super installed before
1557 wait_for_state(super
, JV_STATE_LOADING
);
1558 ensure_fields_laid_out(super
);
1559 int num
= JvNumInstanceFields (super
);
1560 _Jv_Field
*field
= JvGetFirstInstanceField (super
);
1563 int field_align
= get_alignment_from_class (field
->type
);
1564 if (field_align
> max_align
)
1565 max_align
= field_align
;
1569 super
= super
->getSuperclass();
1573 // This is the size of the 'static' non-reference fields.
1574 int non_reference_size
= 0;
1575 // This is the size of the 'static' reference fields. We count
1576 // these separately to make it simpler for the GC to scan them.
1577 int reference_size
= 0;
1579 // Although java.lang.Object is never interpreted, an interface can
1580 // have a null superclass. Note that we have to lay out an
1581 // interface because it might have static fields.
1582 if (klass
->superclass
)
1583 instance_size
= klass
->superclass
->size();
1585 instance_size
= java::lang::Object::class$
.size();
1587 klass
->engine
->allocate_field_initializers (klass
);
1589 for (int i
= 0; i
< klass
->field_count
; i
++)
1594 _Jv_Field
*field
= &klass
->fields
[i
];
1596 if (! field
->isRef ())
1598 // It is safe to resolve the field here, since it's a
1599 // primitive class, which does not cause loading to happen.
1600 resolve_field (field
, klass
->loader
);
1601 field_size
= field
->type
->size ();
1602 field_align
= get_alignment_from_class (field
->type
);
1606 field_size
= sizeof (jobject
);
1607 field_align
= __alignof__ (jobject
);
1610 field
->bsize
= field_size
;
1612 if ((field
->flags
& java::lang::reflect::Modifier::STATIC
))
1614 if (field
->u
.addr
== NULL
)
1616 // This computes an offset into a region we'll allocate
1617 // shortly, and then adds this offset to the start
1621 reference_size
= ROUND (reference_size
, field_align
);
1622 field
->u
.boffset
= reference_size
;
1623 reference_size
+= field_size
;
1627 non_reference_size
= ROUND (non_reference_size
, field_align
);
1628 field
->u
.boffset
= non_reference_size
;
1629 non_reference_size
+= field_size
;
1635 instance_size
= ROUND (instance_size
, field_align
);
1636 field
->u
.boffset
= instance_size
;
1637 instance_size
+= field_size
;
1638 if (field_align
> max_align
)
1639 max_align
= field_align
;
1643 if (reference_size
!= 0 || non_reference_size
!= 0)
1644 klass
->engine
->allocate_static_fields (klass
, reference_size
,
1645 non_reference_size
);
1647 // Set the instance size for the class. Note that first we round it
1648 // to the alignment required for this object; this keeps us in sync
1649 // with our current ABI.
1650 instance_size
= ROUND (instance_size
, max_align
);
1651 klass
->size_in_bytes
= instance_size
;
1654 // This takes the class to state JV_STATE_LINKED. The class lock must
1655 // be held when calling this.
1657 _Jv_Linker::ensure_class_linked (jclass klass
)
1659 if (klass
->state
>= JV_STATE_LINKED
)
1662 int state
= klass
->state
;
1665 // Short-circuit, so that mutually dependent classes are ok.
1666 klass
->state
= JV_STATE_LINKED
;
1668 _Jv_Constants
*pool
= &klass
->constants
;
1670 // Compiled classes require that their class constants be
1671 // resolved here. However, interpreted classes need their
1672 // constants to be resolved lazily. If we resolve an
1673 // interpreted class' constants eagerly, we can end up with
1674 // spurious IllegalAccessErrors when the constant pool contains
1675 // a reference to a class we can't access. This can validly
1676 // occur in an obscure case involving the InnerClasses
1678 if (! _Jv_IsInterpretedClass (klass
))
1680 // Resolve class constants first, since other constant pool
1681 // entries may rely on these.
1682 for (int index
= 1; index
< pool
->size
; ++index
)
1684 if (pool
->tags
[index
] == JV_CONSTANT_Class
)
1685 // Lazily resolve the entries.
1686 resolve_pool_entry (klass
, index
, true);
1690 // Resolve the remaining constant pool entries.
1691 for (int index
= 1; index
< pool
->size
; ++index
)
1693 if (pool
->tags
[index
] == JV_CONSTANT_String
)
1697 str
= _Jv_NewStringUtf8Const (pool
->data
[index
].utf8
);
1698 pool
->data
[index
].o
= str
;
1699 pool
->tags
[index
] |= JV_CONSTANT_ResolvedFlag
;
1703 if (klass
->engine
->need_resolve_string_fields())
1705 jfieldID f
= JvGetFirstStaticField (klass
);
1706 for (int n
= JvNumStaticFields (klass
); n
> 0; --n
)
1708 int mod
= f
->getModifiers ();
1709 // If we have a static String field with a non-null initial
1710 // value, we know it points to a Utf8Const.
1712 // Finds out whether we have to initialize a String without the
1713 // need to resolve the field.
1714 if ((f
->isResolved()
1715 ? (f
->type
== &java::lang::String::class$
)
1716 : _Jv_equalUtf8Classnames((_Jv_Utf8Const
*) f
->type
,
1717 java::lang::String::class$
.name
))
1718 && (mod
& java::lang::reflect::Modifier::STATIC
) != 0)
1720 jstring
*strp
= (jstring
*) f
->u
.addr
;
1722 *strp
= _Jv_NewStringUtf8Const ((_Jv_Utf8Const
*) *strp
);
1724 f
= f
->getNextField ();
1728 klass
->notifyAll ();
1730 _Jv_PushClass (klass
);
1732 catch (java::lang::Throwable
*t
)
1734 klass
->state
= state
;
1739 // This ensures that symbolic superclass and superinterface references
1740 // are resolved for the indicated class. This must be called with the
1743 _Jv_Linker::ensure_supers_installed (jclass klass
)
1745 resolve_class_ref (klass
, &klass
->superclass
);
1746 // An interface won't have a superclass.
1747 if (klass
->superclass
)
1748 wait_for_state (klass
->superclass
, JV_STATE_LOADING
);
1750 for (int i
= 0; i
< klass
->interface_count
; ++i
)
1752 resolve_class_ref (klass
, &klass
->interfaces
[i
]);
1753 wait_for_state (klass
->interfaces
[i
], JV_STATE_LOADING
);
1757 // This adds missing `Miranda methods' to a class.
1759 _Jv_Linker::add_miranda_methods (jclass base
, jclass iface_class
)
1761 // Note that at this point, all our supers, and the supers of all
1762 // our superclasses and superinterfaces, will have been installed.
1764 for (int i
= 0; i
< iface_class
->interface_count
; ++i
)
1766 jclass interface
= iface_class
->interfaces
[i
];
1768 for (int j
= 0; j
< interface
->method_count
; ++j
)
1770 _Jv_Method
*meth
= &interface
->methods
[j
];
1771 // Don't bother with <clinit>.
1772 if (meth
->name
->first() == '<')
1774 _Jv_Method
*new_meth
= _Jv_LookupDeclaredMethod (base
, meth
->name
,
1778 // We assume that such methods are very unlikely, so we
1779 // just reallocate the method array each time one is
1780 // found. This greatly simplifies the searching --
1781 // otherwise we have to make sure that each such method
1782 // found is really unique among all superinterfaces.
1783 int new_count
= base
->method_count
+ 1;
1785 = (_Jv_Method
*) _Jv_AllocRawObj (sizeof (_Jv_Method
)
1787 memcpy (new_m
, base
->methods
,
1788 sizeof (_Jv_Method
) * base
->method_count
);
1791 new_m
[base
->method_count
] = *meth
;
1792 new_m
[base
->method_count
].index
= (_Jv_ushort
) -1;
1793 new_m
[base
->method_count
].accflags
1794 |= java::lang::reflect::Modifier::INVISIBLE
;
1796 base
->methods
= new_m
;
1797 base
->method_count
= new_count
;
1801 wait_for_state (interface
, JV_STATE_LOADED
);
1802 add_miranda_methods (base
, interface
);
1806 // This ensures that the class' method table is "complete". This must
1807 // be called with the class lock held.
1809 _Jv_Linker::ensure_method_table_complete (jclass klass
)
1811 if (klass
->vtable
!= NULL
)
1814 // We need our superclass to have its own Miranda methods installed.
1815 if (! klass
->isInterface())
1816 wait_for_state (klass
->getSuperclass (), JV_STATE_LOADED
);
1818 // A class might have so-called "Miranda methods". This is a method
1819 // that is declared in an interface and not re-declared in an
1820 // abstract class. Some compilers don't emit declarations for such
1821 // methods in the class; this will give us problems since we expect
1822 // a declaration for any method requiring a vtable entry. We handle
1823 // this here by searching for such methods and constructing new
1824 // internal declarations for them. Note that we do this
1825 // unconditionally, and not just for abstract classes, to correctly
1826 // account for cases where a class is modified to be concrete and
1827 // still incorrectly inherits an abstract method.
1828 int pre_count
= klass
->method_count
;
1829 add_miranda_methods (klass
, klass
);
1831 // Let the execution engine know that we've added methods.
1832 if (klass
->method_count
!= pre_count
)
1833 klass
->engine
->post_miranda_hook(klass
);
1836 // Verify a class. Must be called with class lock held.
1838 _Jv_Linker::verify_class (jclass klass
)
1840 klass
->engine
->verify(klass
);
1843 // Check the assertions contained in the type assertion table for KLASS.
1844 // This is the equivilent of bytecode verification for native, BC-ABI code.
1846 _Jv_Linker::verify_type_assertions (jclass klass
)
1849 fprintf (stderr
, "Evaluating type assertions for %s:\n",
1850 klass
->name
->chars());
1852 if (klass
->assertion_table
== NULL
)
1855 for (int i
= 0;; i
++)
1857 int assertion_code
= klass
->assertion_table
[i
].assertion_code
;
1858 _Jv_Utf8Const
*op1
= klass
->assertion_table
[i
].op1
;
1859 _Jv_Utf8Const
*op2
= klass
->assertion_table
[i
].op2
;
1861 if (assertion_code
== JV_ASSERT_END_OF_TABLE
)
1863 else if (assertion_code
== JV_ASSERT_TYPES_COMPATIBLE
)
1867 fprintf (stderr
, " code=%i, operand A=%s B=%s\n",
1868 assertion_code
, op1
->chars(), op2
->chars());
1871 // The operands are class signatures. op1 is the source,
1872 // op2 is the target.
1873 jclass cl1
= _Jv_FindClassFromSignature (op1
->chars(),
1874 klass
->getClassLoaderInternal());
1875 jclass cl2
= _Jv_FindClassFromSignature (op2
->chars(),
1876 klass
->getClassLoaderInternal());
1878 // If the class doesn't exist, ignore the assertion. An exception
1879 // will be thrown later if an attempt is made to actually
1880 // instantiate the class.
1881 if (cl1
== NULL
|| cl2
== NULL
)
1884 if (! _Jv_IsAssignableFromSlow (cl1
, cl2
))
1886 jstring s
= JvNewStringUTF ("Incompatible types: In class ");
1887 s
= s
->concat (klass
->getName());
1888 s
= s
->concat (JvNewStringUTF (": "));
1889 s
= s
->concat (cl1
->getName());
1890 s
= s
->concat (JvNewStringUTF (" is not assignable to "));
1891 s
= s
->concat (cl2
->getName());
1892 throw new java::lang::VerifyError (s
);
1895 else if (assertion_code
== JV_ASSERT_IS_INSTANTIABLE
)
1897 // TODO: Implement this.
1899 // Unknown assertion codes are ignored, for forwards-compatibility.
1904 _Jv_Linker::print_class_loaded (jclass klass
)
1906 char *codesource
= NULL
;
1907 if (klass
->protectionDomain
!= NULL
)
1909 java::security::CodeSource
*cs
1910 = klass
->protectionDomain
->getCodeSource();
1913 jstring css
= cs
->toString();
1914 int len
= JvGetStringUTFLength(css
);
1915 codesource
= (char *) _Jv_AllocBytes(len
+ 1);
1916 JvGetStringUTFRegion(css
, 0, css
->length(), codesource
);
1917 codesource
[len
] = '\0';
1920 if (codesource
== NULL
)
1921 codesource
= (char *) "<no code source>";
1924 if (_Jv_IsInterpretedClass (klass
))
1926 else if (_Jv_IsBinaryCompatibilityABI (klass
))
1927 abi
= "BC-compiled";
1929 abi
= "pre-compiled";
1931 fprintf (stderr
, "[Loaded (%s) %s from %s]\n", abi
, klass
->name
->chars(),
1935 // FIXME: mention invariants and stuff.
1937 _Jv_Linker::wait_for_state (jclass klass
, int state
)
1939 if (klass
->state
>= state
)
1942 JvSynchronize
sync (klass
);
1944 // This is similar to the strategy for class initialization. If we
1945 // already hold the lock, just leave.
1946 java::lang::Thread
*self
= java::lang::Thread::currentThread();
1947 while (klass
->state
<= state
1949 && klass
->thread
!= self
)
1952 java::lang::Thread
*save
= klass
->thread
;
1953 klass
->thread
= self
;
1955 // Allocate memory for static fields and constants.
1956 if (GC_base (klass
) && klass
->fields
&& ! GC_base (klass
->fields
))
1958 jsize count
= klass
->field_count
;
1962 = (_Jv_Field
*) _Jv_AllocRawObj (count
* sizeof (_Jv_Field
));
1963 memcpy ((void*)fields
,
1964 (void*)klass
->fields
,
1965 count
* sizeof (_Jv_Field
));
1966 klass
->fields
= fields
;
1970 // Print some debugging info if requested. Interpreted classes are
1971 // handled in defineclass, so we only need to handle the two
1972 // pre-compiled cases here.
1973 if ((klass
->state
== JV_STATE_COMPILED
1974 || klass
->state
== JV_STATE_PRELOADING
)
1975 && ! _Jv_IsInterpretedClass (klass
))
1977 if (gcj::verbose_class_flag
)
1978 print_class_loaded (klass
);
1979 ++gcj::loadedClasses
;
1984 if (state
>= JV_STATE_LOADING
&& klass
->state
< JV_STATE_LOADING
)
1986 ensure_supers_installed (klass
);
1987 klass
->set_state(JV_STATE_LOADING
);
1990 if (state
>= JV_STATE_LOADED
&& klass
->state
< JV_STATE_LOADED
)
1992 ensure_method_table_complete (klass
);
1993 klass
->set_state(JV_STATE_LOADED
);
1996 if (state
>= JV_STATE_PREPARED
&& klass
->state
< JV_STATE_PREPARED
)
1998 ensure_fields_laid_out (klass
);
1999 make_vtable (klass
);
2000 layout_interface_methods (klass
);
2001 prepare_constant_time_tables (klass
);
2002 klass
->set_state(JV_STATE_PREPARED
);
2005 if (state
>= JV_STATE_LINKED
&& klass
->state
< JV_STATE_LINKED
)
2007 if (gcj::verifyClasses
)
2008 verify_class (klass
);
2010 ensure_class_linked (klass
);
2011 link_exception_table (klass
);
2012 link_symbol_table (klass
);
2013 klass
->set_state(JV_STATE_LINKED
);
2016 catch (java::lang::Throwable
*exc
)
2018 klass
->thread
= save
;
2019 klass
->set_state(JV_STATE_ERROR
);
2023 klass
->thread
= save
;
2025 if (klass
->state
== JV_STATE_ERROR
)
2026 throw new java::lang::LinkageError
;