1 // link.cc - Code for linking and resolving classes and pool entries.
3 /* Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
4 Free Software Foundation
6 This file is part of libgcj.
8 This software is copyrighted work licensed under the terms of the
9 Libgcj License. Please consult the file "LIBGCJ_LICENSE" for
12 /* Author: Kresten Krab Thorup <krab@gnu.org> */
23 #include <java-interp.h>
25 // Set GC_DEBUG before including gc.h!
26 #ifdef LIBGCJ_GC_DEBUG
35 #include <java-cpool.h>
36 #include <execution.h>
39 #include "jvmti-int.h"
41 #include <java/lang/Class.h>
42 #include <java/lang/String.h>
43 #include <java/lang/StringBuffer.h>
44 #include <java/lang/Thread.h>
45 #include <java/lang/InternalError.h>
46 #include <java/lang/VirtualMachineError.h>
47 #include <java/lang/VerifyError.h>
48 #include <java/lang/NoSuchFieldError.h>
49 #include <java/lang/NoSuchMethodError.h>
50 #include <java/lang/ClassFormatError.h>
51 #include <java/lang/IllegalAccessError.h>
52 #include <java/lang/InternalError.h>
53 #include <java/lang/AbstractMethodError.h>
54 #include <java/lang/NoClassDefFoundError.h>
55 #include <java/lang/IncompatibleClassChangeError.h>
56 #include <java/lang/VerifyError.h>
57 #include <java/lang/VMClassLoader.h>
58 #include <java/lang/reflect/Modifier.h>
59 #include <java/security/CodeSource.h>
70 #define ALIGNOF(TYPE) (offsetof (aligner<TYPE>, field))
72 // This returns the alignment of a type as it would appear in a
73 // structure. This can be different from the alignment of the type
74 // itself. For instance on x86 double is 8-aligned but struct{double}
77 _Jv_Linker::get_alignment_from_class (jclass klass
)
79 if (klass
== JvPrimClass (byte
))
80 return ALIGNOF (jbyte
);
81 else if (klass
== JvPrimClass (short))
82 return ALIGNOF (jshort
);
83 else if (klass
== JvPrimClass (int))
84 return ALIGNOF (jint
);
85 else if (klass
== JvPrimClass (long))
86 return ALIGNOF (jlong
);
87 else if (klass
== JvPrimClass (boolean
))
88 return ALIGNOF (jboolean
);
89 else if (klass
== JvPrimClass (char))
90 return ALIGNOF (jchar
);
91 else if (klass
== JvPrimClass (float))
92 return ALIGNOF (jfloat
);
93 else if (klass
== JvPrimClass (double))
94 return ALIGNOF (jdouble
);
96 return ALIGNOF (jobject
);
100 _Jv_Linker::resolve_field (_Jv_Field
*field
, java::lang::ClassLoader
*loader
)
102 if (! field
->isResolved ())
104 _Jv_Utf8Const
*sig
= (_Jv_Utf8Const
*) field
->type
;
105 jclass type
= _Jv_FindClassFromSignature (sig
->chars(), loader
);
107 throw new java::lang::NoClassDefFoundError(field
->name
->toString());
109 field
->flags
&= ~_Jv_FIELD_UNRESOLVED_FLAG
;
113 // A helper for find_field that knows how to recursively search
114 // superclasses and interfaces.
116 _Jv_Linker::find_field_helper (jclass search
, _Jv_Utf8Const
*name
,
117 _Jv_Utf8Const
*type_name
, jclass type
,
122 // From 5.4.3.2. First search class itself.
123 for (int i
= 0; i
< search
->field_count
; ++i
)
125 _Jv_Field
*field
= &search
->fields
[i
];
126 if (! _Jv_equalUtf8Consts (field
->name
, name
))
129 // Checks for the odd situation where we were able to retrieve the
130 // field's class from signature but the resolution of the field itself
131 // failed which means a different class was resolved.
136 resolve_field (field
, search
->loader
);
138 catch (java::lang::Throwable
*exc
)
140 java::lang::LinkageError
*le
= new java::lang::LinkageError
142 ("field type mismatch with different loaders"));
150 // Note that we compare type names and not types. This is
151 // bizarre, but we do it because we want to find a field
152 // (and terminate the search) if it has the correct
153 // descriptor -- but then later reject it if the class
154 // loader check results in different classes. We can't just
155 // pass in the descriptor and check that way, because when
156 // the field is already resolved there is no easy way to
157 // find its descriptor again.
158 if ((field
->isResolved ()
159 ? _Jv_equalUtf8Classnames (type_name
, field
->type
->name
)
160 : _Jv_equalUtf8Classnames (type_name
,
161 (_Jv_Utf8Const
*) field
->type
)))
168 // Next search direct interfaces.
169 for (int i
= 0; i
< search
->interface_count
; ++i
)
171 _Jv_Field
*result
= find_field_helper (search
->interfaces
[i
], name
,
172 type_name
, type
, declarer
);
177 // Now search superclass.
178 search
= search
->superclass
;
185 _Jv_Linker::has_field_p (jclass search
, _Jv_Utf8Const
*field_name
)
187 for (int i
= 0; i
< search
->field_count
; ++i
)
189 _Jv_Field
*field
= &search
->fields
[i
];
190 if (_Jv_equalUtf8Consts (field
->name
, field_name
))
197 // KLASS is the class that is requesting the field.
198 // OWNER is the class in which the field should be found.
199 // FIELD_TYPE_NAME is the type descriptor for the field.
200 // Fill FOUND_CLASS with the address of the class in which the field
201 // is actually declared.
202 // This function does the class loader type checks, and
203 // also access checks. Returns the field, or throws an
204 // exception on error.
206 _Jv_Linker::find_field (jclass klass
, jclass owner
,
208 _Jv_Utf8Const
*field_name
,
209 _Jv_Utf8Const
*field_type_name
)
211 // FIXME: this allocates a _Jv_Utf8Const each time. We should make
213 // Note: This call will resolve the primitive type names ("Z", "B", ...) to
214 // their Java counterparts ("boolean", "byte", ...) if accessed via
215 // field_type->name later. Using these variants of the type name is in turn
216 // important for the find_field_helper function. However if the class
217 // resolution failed then we can only use the already given type name.
219 = _Jv_FindClassFromSignatureNoException (field_type_name
->chars(),
223 = find_field_helper (owner
, field_name
,
227 field_type
, found_class
);
231 java::lang::StringBuffer
*sb
= new java::lang::StringBuffer();
232 sb
->append(JvNewStringLatin1("field "));
233 sb
->append(owner
->getName());
234 sb
->append(JvNewStringLatin1("."));
235 sb
->append(_Jv_NewStringUTF(field_name
->chars()));
236 sb
->append(JvNewStringLatin1(" was not found."));
237 throw new java::lang::NoSuchFieldError (sb
->toString());
240 // Accept it when the field's class could not be resolved.
241 if (field_type
== NULL
)
242 // Silently ignore that we were not able to retrieve the type to make it
243 // possible to run code which does not access this field.
246 if (_Jv_CheckAccess (klass
, *found_class
, the_field
->flags
))
248 // Note that the field returned by find_field_helper is always
249 // resolved. However, we still use the constraint mechanism
250 // because this may affect other lookups.
251 _Jv_CheckOrCreateLoadingConstraint (klass
, (*found_class
)->loader
);
255 java::lang::StringBuffer
*sb
256 = new java::lang::StringBuffer ();
257 sb
->append(klass
->getName());
258 sb
->append(JvNewStringLatin1(": "));
259 sb
->append((*found_class
)->getName());
260 sb
->append(JvNewStringLatin1("."));
261 sb
->append(_Jv_NewStringUtf8Const (field_name
));
262 throw new java::lang::IllegalAccessError(sb
->toString());
268 // Check loading constraints for method.
270 _Jv_Linker::check_loading_constraints (_Jv_Method
*method
, jclass self_class
,
273 JArray
<jclass
> *klass_args
;
276 _Jv_GetTypesFromSignature (method
, self_class
, &klass_args
, &klass_return
);
277 jclass
*klass_arg
= elements (klass_args
);
278 java::lang::ClassLoader
*found_loader
= other_class
->loader
;
280 _Jv_CheckOrCreateLoadingConstraint (klass_return
, found_loader
);
281 for (int i
= 0; i
< klass_args
->length
; i
++)
282 _Jv_CheckOrCreateLoadingConstraint (*(klass_arg
++), found_loader
);
286 _Jv_Linker::resolve_method_entry (jclass klass
, jclass
&found_class
,
287 int class_index
, int name_and_type_index
,
288 bool init
, bool is_iface
)
290 _Jv_Constants
*pool
= &klass
->constants
;
291 jclass owner
= resolve_pool_entry (klass
, class_index
).clazz
;
293 if (init
&& owner
!= klass
)
294 _Jv_InitClass (owner
);
296 _Jv_ushort name_index
, type_index
;
297 _Jv_loadIndexes (&pool
->data
[name_and_type_index
],
301 _Jv_Utf8Const
*method_name
= pool
->data
[name_index
].utf8
;
302 _Jv_Utf8Const
*method_signature
= pool
->data
[type_index
].utf8
;
304 _Jv_Method
*the_method
= 0;
307 // We're going to cache a pointer to the _Jv_Method object
308 // when we find it. So, to ensure this doesn't get moved from
309 // beneath us, we first put all the needed Miranda methods
310 // into the target class.
311 wait_for_state (klass
, JV_STATE_LOADED
);
313 // First search the class itself.
314 the_method
= search_method_in_class (owner
, klass
,
315 method_name
, method_signature
);
320 goto end_of_method_search
;
323 // If we are resolving an interface method, search the
324 // interface's superinterfaces (A superinterface is not an
325 // interface's superclass - a superinterface is implemented by
332 ifaces
.list
= (jclass
*) _Jv_Malloc (ifaces
.len
333 * sizeof (jclass
*));
335 get_interfaces (owner
, &ifaces
);
337 for (int i
= 0; i
< ifaces
.count
; i
++)
339 jclass cls
= ifaces
.list
[i
];
340 the_method
= search_method_in_class (cls
, klass
, method_name
,
349 _Jv_Free (ifaces
.list
);
352 goto end_of_method_search
;
355 // Finally, search superclasses.
356 the_method
= (search_method_in_superclasses
357 (owner
->getSuperclass (), klass
, method_name
,
358 method_signature
, &found_class
));
361 end_of_method_search
:
364 java::lang::StringBuffer
*sb
= new java::lang::StringBuffer();
365 sb
->append(JvNewStringLatin1("method "));
366 sb
->append(owner
->getName());
367 sb
->append(JvNewStringLatin1("."));
368 sb
->append(_Jv_NewStringUTF(method_name
->chars()));
369 sb
->append(JvNewStringLatin1(" with signature "));
370 sb
->append(_Jv_NewStringUTF(method_signature
->chars()));
371 sb
->append(JvNewStringLatin1(" was not found."));
372 throw new java::lang::NoSuchMethodError (sb
->toString());
375 // if (found_class->loader != klass->loader), then we must actually
376 // check that the types of arguments correspond. JVMS 5.4.3.3.
377 if (found_class
->loader
!= klass
->loader
)
378 check_loading_constraints (the_method
, klass
, found_class
);
384 _Jv_Linker::resolve_pool_entry (jclass klass
, int index
, bool lazy
)
386 using namespace java::lang::reflect
;
388 if (GC_base (klass
) && klass
->constants
.data
389 && ! GC_base (klass
->constants
.data
))
391 jsize count
= klass
->constants
.size
;
395 = (_Jv_word
*) _Jv_AllocRawObj (count
* sizeof (_Jv_word
));
396 memcpy ((void*)constants
,
397 (void*)klass
->constants
.data
,
398 count
* sizeof (_Jv_word
));
399 klass
->constants
.data
= constants
;
403 _Jv_Constants
*pool
= &klass
->constants
;
405 if ((pool
->tags
[index
] & JV_CONSTANT_ResolvedFlag
) != 0)
406 return pool
->data
[index
];
408 switch (pool
->tags
[index
] & ~JV_CONSTANT_LazyFlag
)
410 case JV_CONSTANT_Class
:
412 _Jv_Utf8Const
*name
= pool
->data
[index
].utf8
;
415 if (name
->first() == '[')
416 found
= _Jv_FindClassFromSignatureNoException (name
->chars(),
419 found
= _Jv_FindClassNoException (name
, klass
->loader
);
421 // If the class could not be loaded a phantom class is created. Any
422 // function that deals with such a class but cannot do something useful
423 // with it should just throw a NoClassDefFoundError with the class'
429 found
= _Jv_NewClass(name
, NULL
, NULL
);
430 found
->state
= JV_STATE_PHANTOM
;
431 pool
->tags
[index
] |= JV_CONSTANT_ResolvedFlag
;
432 pool
->data
[index
].clazz
= found
;
436 throw new java::lang::NoClassDefFoundError (name
->toString());
439 // Check accessibility, but first strip array types as
440 // _Jv_ClassNameSamePackage can't handle arrays.
443 check
&& check
->isArray();
444 check
= check
->getComponentType())
446 if ((found
->accflags
& Modifier::PUBLIC
) == Modifier::PUBLIC
447 || (_Jv_ClassNameSamePackage (check
->name
,
450 pool
->data
[index
].clazz
= found
;
451 pool
->tags
[index
] |= JV_CONSTANT_ResolvedFlag
;
455 java::lang::StringBuffer
*sb
= new java::lang::StringBuffer ();
456 sb
->append(klass
->getName());
457 sb
->append(JvNewStringLatin1(" can't access class "));
458 sb
->append(found
->getName());
459 throw new java::lang::IllegalAccessError(sb
->toString());
464 case JV_CONSTANT_String
:
467 str
= _Jv_NewStringUtf8Const (pool
->data
[index
].utf8
);
468 pool
->data
[index
].o
= str
;
469 pool
->tags
[index
] |= JV_CONSTANT_ResolvedFlag
;
473 case JV_CONSTANT_Fieldref
:
475 _Jv_ushort class_index
, name_and_type_index
;
476 _Jv_loadIndexes (&pool
->data
[index
],
478 name_and_type_index
);
479 jclass owner
= (resolve_pool_entry (klass
, class_index
, true)).clazz
;
481 // If a phantom class was resolved our field reference is
482 // unusable because of the missing class.
483 if (owner
->state
== JV_STATE_PHANTOM
)
484 throw new java::lang::NoClassDefFoundError(owner
->getName());
486 // We don't initialize 'owner', but we do make sure that its
488 wait_for_state (owner
, JV_STATE_PREPARED
);
490 _Jv_ushort name_index
, type_index
;
491 _Jv_loadIndexes (&pool
->data
[name_and_type_index
],
495 _Jv_Utf8Const
*field_name
= pool
->data
[name_index
].utf8
;
496 _Jv_Utf8Const
*field_type_name
= pool
->data
[type_index
].utf8
;
498 jclass found_class
= 0;
499 _Jv_Field
*the_field
= find_field (klass
, owner
,
503 // Initialize the field's declaring class, not its qualifying
505 _Jv_InitClass (found_class
);
506 pool
->data
[index
].field
= the_field
;
507 pool
->tags
[index
] |= JV_CONSTANT_ResolvedFlag
;
511 case JV_CONSTANT_Methodref
:
512 case JV_CONSTANT_InterfaceMethodref
:
514 _Jv_ushort class_index
, name_and_type_index
;
515 _Jv_loadIndexes (&pool
->data
[index
],
517 name_and_type_index
);
519 _Jv_Method
*the_method
;
521 the_method
= resolve_method_entry (klass
, found_class
,
522 class_index
, name_and_type_index
,
524 pool
->tags
[index
] == JV_CONSTANT_InterfaceMethodref
);
526 pool
->data
[index
].rmethod
527 = klass
->engine
->resolve_method(the_method
,
529 ((the_method
->accflags
530 & Modifier::STATIC
) != 0));
531 pool
->tags
[index
] |= JV_CONSTANT_ResolvedFlag
;
535 return pool
->data
[index
];
538 // This function is used to lazily locate superclasses and
539 // superinterfaces. This must be called with the class lock held.
541 _Jv_Linker::resolve_class_ref (jclass klass
, jclass
*classref
)
543 jclass ret
= *classref
;
545 // If superclass looks like a constant pool entry, resolve it now.
546 if (ret
&& (uaddr
) ret
< (uaddr
) klass
->constants
.size
)
548 if (klass
->state
< JV_STATE_LINKED
)
550 _Jv_Utf8Const
*name
= klass
->constants
.data
[(uaddr
) *classref
].utf8
;
551 ret
= _Jv_FindClass (name
, klass
->loader
);
554 throw new java::lang::NoClassDefFoundError (name
->toString());
558 ret
= klass
->constants
.data
[(uaddr
) classref
].clazz
;
563 // Find a method declared in the cls that is referenced from klass and
564 // perform access checks if CHECK_PERMS is true.
566 _Jv_Linker::search_method_in_class (jclass cls
, jclass klass
,
567 _Jv_Utf8Const
*method_name
,
568 _Jv_Utf8Const
*method_signature
,
571 using namespace java::lang::reflect
;
573 for (int i
= 0; i
< cls
->method_count
; i
++)
575 _Jv_Method
*method
= &cls
->methods
[i
];
576 if ( (!_Jv_equalUtf8Consts (method
->name
,
578 || (!_Jv_equalUtf8Consts (method
->signature
,
582 if (!check_perms
|| _Jv_CheckAccess (klass
, cls
, method
->accflags
))
586 java::lang::StringBuffer
*sb
= new java::lang::StringBuffer();
587 sb
->append(klass
->getName());
588 sb
->append(JvNewStringLatin1(": "));
589 sb
->append(cls
->getName());
590 sb
->append(JvNewStringLatin1("."));
591 sb
->append(_Jv_NewStringUTF(method_name
->chars()));
592 sb
->append(_Jv_NewStringUTF(method_signature
->chars()));
593 throw new java::lang::IllegalAccessError (sb
->toString());
599 // Like search_method_in_class, but work our way up the superclass
602 _Jv_Linker::search_method_in_superclasses (jclass cls
, jclass klass
,
603 _Jv_Utf8Const
*method_name
,
604 _Jv_Utf8Const
*method_signature
,
605 jclass
*found_class
, bool check_perms
)
607 _Jv_Method
*the_method
= NULL
;
609 for ( ; cls
!= 0; cls
= cls
->getSuperclass ())
611 the_method
= search_method_in_class (cls
, klass
, method_name
,
612 method_signature
, check_perms
);
624 #define INITIAL_IOFFSETS_LEN 4
625 #define INITIAL_IFACES_LEN 4
627 static _Jv_IDispatchTable null_idt
= {SHRT_MAX
, 0, {}};
629 // Generate tables for constant-time assignment testing and interface
630 // method lookup. This implements the technique described by Per Bothner
631 // <per@bothner.com> on the java-discuss mailing list on 1999-09-02:
632 // http://gcc.gnu.org/ml/java/1999-q3/msg00377.html
634 _Jv_Linker::prepare_constant_time_tables (jclass klass
)
636 if (klass
->isPrimitive () || klass
->isInterface ())
639 // Short-circuit in case we've been called already.
640 if ((klass
->idt
!= NULL
) || klass
->depth
!= 0)
643 // Calculate the class depth and ancestor table. The depth of a class
644 // is how many "extends" it is removed from Object. Thus the depth of
645 // java.lang.Object is 0, but the depth of java.io.FilterOutputStream
646 // is 2. Depth is defined for all regular and array classes, but not
647 // interfaces or primitive types.
649 jclass klass0
= klass
;
650 jboolean has_interfaces
= false;
651 while (klass0
!= &java::lang::Object::class$
)
653 if (klass0
->interface_count
)
654 has_interfaces
= true;
655 klass0
= klass0
->superclass
;
659 // We do class member testing in constant time by using a small table
660 // of all the ancestor classes within each class. The first element is
661 // a pointer to the current class, and the rest are pointers to the
662 // classes ancestors, ordered from the current class down by decreasing
663 // depth. We do not include java.lang.Object in the table of ancestors,
664 // since it is redundant. Note that the classes pointed to by
665 // 'ancestors' will always be reachable by other paths.
667 klass
->ancestors
= (jclass
*) _Jv_AllocBytes (klass
->depth
670 for (int index
= 0; index
< klass
->depth
; index
++)
672 klass
->ancestors
[index
] = klass0
;
673 klass0
= klass0
->superclass
;
676 if ((klass
->accflags
& java::lang::reflect::Modifier::ABSTRACT
) != 0)
679 // Optimization: If class implements no interfaces, use a common
680 // predefined interface table.
683 klass
->idt
= &null_idt
;
689 ifaces
.len
= INITIAL_IFACES_LEN
;
690 ifaces
.list
= (jclass
*) _Jv_Malloc (ifaces
.len
* sizeof (jclass
*));
692 int itable_size
= get_interfaces (klass
, &ifaces
);
694 if (ifaces
.count
> 0)
696 // The classes pointed to by the itable will always be reachable
698 int idt_bytes
= sizeof (_Jv_IDispatchTable
) + (itable_size
700 klass
->idt
= (_Jv_IDispatchTable
*) _Jv_AllocBytes (idt_bytes
);
701 klass
->idt
->itable_length
= itable_size
;
703 jshort
*itable_offsets
=
704 (jshort
*) _Jv_Malloc (ifaces
.count
* sizeof (jshort
));
706 generate_itable (klass
, &ifaces
, itable_offsets
);
708 jshort cls_iindex
= find_iindex (ifaces
.list
, itable_offsets
,
711 for (int i
= 0; i
< ifaces
.count
; i
++)
713 ifaces
.list
[i
]->ioffsets
[cls_iindex
] = itable_offsets
[i
];
716 klass
->idt
->iindex
= cls_iindex
;
718 _Jv_Free (ifaces
.list
);
719 _Jv_Free (itable_offsets
);
723 klass
->idt
->iindex
= SHRT_MAX
;
727 // Return index of item in list, or -1 if item is not present.
729 _Jv_Linker::indexof (void *item
, void **list
, jshort list_len
)
731 for (int i
=0; i
< list_len
; i
++)
739 // Find all unique interfaces directly or indirectly implemented by klass.
740 // Returns the size of the interface dispatch table (itable) for klass, which
741 // is the number of unique interfaces plus the total number of methods that
742 // those interfaces declare. May extend ifaces if required.
744 _Jv_Linker::get_interfaces (jclass klass
, _Jv_ifaces
*ifaces
)
748 for (int i
= 0; i
< klass
->interface_count
; i
++)
750 jclass iface
= klass
->interfaces
[i
];
752 /* Make sure interface is linked. */
753 wait_for_state(iface
, JV_STATE_LINKED
);
755 if (indexof (iface
, (void **) ifaces
->list
, ifaces
->count
) == -1)
757 if (ifaces
->count
+ 1 >= ifaces
->len
)
759 /* Resize ifaces list */
760 ifaces
->len
= ifaces
->len
* 2;
762 = (jclass
*) _Jv_Realloc (ifaces
->list
,
763 ifaces
->len
* sizeof(jclass
));
765 ifaces
->list
[ifaces
->count
] = iface
;
768 result
+= get_interfaces (klass
->interfaces
[i
], ifaces
);
772 if (klass
->isInterface())
774 // We want to add 1 plus the number of interface methods here.
775 // But, we take special care to skip <clinit>.
777 for (int i
= 0; i
< klass
->method_count
; ++i
)
779 if (klass
->methods
[i
].name
->first() != '<')
783 else if (klass
->superclass
)
784 result
+= get_interfaces (klass
->superclass
, ifaces
);
788 // Fill out itable in klass, resolving method declarations in each ifaces.
789 // itable_offsets is filled out with the position of each iface in itable,
790 // such that itable[itable_offsets[n]] == ifaces.list[n].
792 _Jv_Linker::generate_itable (jclass klass
, _Jv_ifaces
*ifaces
,
793 jshort
*itable_offsets
)
795 void **itable
= klass
->idt
->itable
;
796 jshort itable_pos
= 0;
798 for (int i
= 0; i
< ifaces
->count
; i
++)
800 jclass iface
= ifaces
->list
[i
];
801 itable_offsets
[i
] = itable_pos
;
802 itable_pos
= append_partial_itable (klass
, iface
, itable
, itable_pos
);
804 /* Create ioffsets table for iface */
805 if (iface
->ioffsets
== NULL
)
807 // The first element of ioffsets is its length (itself included).
808 jshort
*ioffsets
= (jshort
*) _Jv_AllocBytes (INITIAL_IOFFSETS_LEN
810 ioffsets
[0] = INITIAL_IOFFSETS_LEN
;
811 for (int i
= 1; i
< INITIAL_IOFFSETS_LEN
; i
++)
814 iface
->ioffsets
= ioffsets
;
819 // Format method name for use in error messages.
821 _Jv_GetMethodString (jclass klass
, _Jv_Method
*meth
,
824 using namespace java::lang
;
825 StringBuffer
*buf
= new StringBuffer (klass
->name
->toString());
826 buf
->append (jchar ('.'));
827 buf
->append (meth
->name
->toString());
828 buf
->append ((jchar
) ' ');
829 buf
->append (meth
->signature
->toString());
832 buf
->append(JvNewStringLatin1(" in "));
833 buf
->append(derived
->name
->toString());
835 return buf
->toString();
839 _Jv_ThrowNoSuchMethodError ()
841 throw new java::lang::NoSuchMethodError
;
844 #if defined USE_LIBFFI && FFI_CLOSURES && defined(INTERPRETER)
845 // A function whose invocation is prepared using libffi. It gets called
846 // whenever a static method of a missing class is invoked. The data argument
847 // holds a reference to a String denoting the missing class.
848 // The prepared function call is stored in a class' atable.
850 _Jv_ThrowNoClassDefFoundErrorTrampoline(ffi_cif
*,
855 throw new java::lang::NoClassDefFoundError(
856 _Jv_NewStringUtf8Const((_Jv_Utf8Const
*) data
));
859 // A variant of the NoClassDefFoundError throwing method that can
860 // be used without libffi.
862 _Jv_ThrowNoClassDefFoundError()
864 throw new java::lang::NoClassDefFoundError();
868 // Throw a NoSuchFieldError. Called by compiler-generated code when
869 // an otable entry is zero. OTABLE_INDEX is the index in the caller's
870 // otable that refers to the missing field. This index may be used to
871 // print diagnostic information about the field.
873 _Jv_ThrowNoSuchFieldError (int /* otable_index */)
875 throw new java::lang::NoSuchFieldError
;
878 // This is put in empty vtable slots.
880 _Jv_ThrowAbstractMethodError ()
882 throw new java::lang::AbstractMethodError();
885 // Each superinterface of a class (i.e. each interface that the class
886 // directly or indirectly implements) has a corresponding "Partial
887 // Interface Dispatch Table" whose size is (number of methods + 1) words.
888 // The first word is a pointer to the interface (i.e. the java.lang.Class
889 // instance for that interface). The remaining words are pointers to the
890 // actual methods that implement the methods declared in the interface,
891 // in order of declaration.
893 // Append partial interface dispatch table for "iface" to "itable", at
894 // position itable_pos.
895 // Returns the offset at which the next partial ITable should be appended.
897 _Jv_Linker::append_partial_itable (jclass klass
, jclass iface
,
898 void **itable
, jshort pos
)
900 using namespace java::lang::reflect
;
902 itable
[pos
++] = (void *) iface
;
905 for (int j
=0; j
< iface
->method_count
; j
++)
907 // Skip '<clinit>' here.
908 if (iface
->methods
[j
].name
->first() == '<')
913 for (cl
= klass
; cl
; cl
= cl
->getSuperclass())
915 meth
= _Jv_GetMethodLocal (cl
, iface
->methods
[j
].name
,
916 iface
->methods
[j
].signature
);
924 if ((meth
->accflags
& Modifier::STATIC
) != 0)
925 throw new java::lang::IncompatibleClassChangeError
926 (_Jv_GetMethodString (klass
, meth
));
927 if ((meth
->accflags
& Modifier::PUBLIC
) == 0)
928 throw new java::lang::IllegalAccessError
929 (_Jv_GetMethodString (klass
, meth
));
931 if ((meth
->accflags
& Modifier::ABSTRACT
) != 0)
932 itable
[pos
] = (void *) &_Jv_ThrowAbstractMethodError
;
934 itable
[pos
] = meth
->ncode
;
936 if (cl
->loader
!= iface
->loader
)
937 check_loading_constraints (meth
, cl
, iface
);
941 // The method doesn't exist in klass. Binary compatibility rules
942 // permit this, so we delay the error until runtime using a pointer
943 // to a method which throws an exception.
944 itable
[pos
] = (void *) _Jv_ThrowNoSuchMethodError
;
952 static _Jv_Mutex_t iindex_mutex
;
953 static bool iindex_mutex_initialized
= false;
955 // We need to find the correct offset in the Class Interface Dispatch
956 // Table for a given interface. Once we have that, invoking an interface
957 // method just requires combining the Method's index in the interface
958 // (known at compile time) to get the correct method. Doing a type test
959 // (cast or instanceof) is the same problem: Once we have a possible Partial
960 // Interface Dispatch Table, we just compare the first element to see if it
961 // matches the desired interface. So how can we find the correct offset?
962 // Our solution is to keep a vector of candiate offsets in each interface
963 // (ioffsets), and in each class we have an index (idt->iindex) used to
964 // select the correct offset from ioffsets.
966 // Calculate and return iindex for a new class.
967 // ifaces is a vector of num interfaces that the class implements.
968 // offsets[j] is the offset in the interface dispatch table for the
969 // interface corresponding to ifaces[j].
970 // May extend the interface ioffsets if required.
972 _Jv_Linker::find_iindex (jclass
*ifaces
, jshort
*offsets
, jshort num
)
977 // Acquire a global lock to prevent itable corruption in case of multiple
978 // classes that implement an intersecting set of interfaces being linked
979 // simultaneously. We can assume that the mutex will be initialized
981 if (! iindex_mutex_initialized
)
983 _Jv_MutexInit (&iindex_mutex
);
984 iindex_mutex_initialized
= true;
987 _Jv_MutexLock (&iindex_mutex
);
989 for (i
=1;; i
++) /* each potential position in ioffsets */
991 for (j
=0;; j
++) /* each iface */
995 if (i
>= ifaces
[j
]->ioffsets
[0])
997 int ioffset
= ifaces
[j
]->ioffsets
[i
];
998 /* We can potentially share this position with another class. */
999 if (ioffset
>= 0 && ioffset
!= offsets
[j
])
1000 break; /* Nope. Try next i. */
1004 for (j
= 0; j
< num
; j
++)
1006 int len
= ifaces
[j
]->ioffsets
[0];
1010 int newlen
= 2 * len
;
1014 jshort
*old_ioffsets
= ifaces
[j
]->ioffsets
;
1015 jshort
*new_ioffsets
= (jshort
*) _Jv_AllocBytes (newlen
1017 memcpy (&new_ioffsets
[1], &old_ioffsets
[1],
1018 (len
- 1) * sizeof (jshort
));
1019 new_ioffsets
[0] = newlen
;
1021 while (len
< newlen
)
1022 new_ioffsets
[len
++] = -1;
1024 ifaces
[j
]->ioffsets
= new_ioffsets
;
1026 ifaces
[j
]->ioffsets
[i
] = offsets
[j
];
1029 _Jv_MutexUnlock (&iindex_mutex
);
1034 #if defined USE_LIBFFI && FFI_CLOSURES && defined(INTERPRETER)
1035 // We use a structure of this type to store the closure that
1036 // represents a missing method.
1037 struct method_closure
1039 // This field must come first, since the address of this field will
1040 // be the same as the address of the overall structure. This is due
1041 // to disabling interior pointers in the GC.
1042 ffi_closure closure
;
1043 _Jv_ClosureList list
;
1045 ffi_type
*arg_types
[1];
1049 _Jv_Linker::create_error_method (_Jv_Utf8Const
*class_name
, jclass klass
)
1052 method_closure
*closure
1053 = (method_closure
*)ffi_closure_alloc (sizeof (method_closure
), &code
);
1055 closure
->arg_types
[0] = &ffi_type_void
;
1057 // Initializes the cif and the closure. If that worked the closure
1058 // is returned and can be used as a function pointer in a class'
1060 if ( ffi_prep_cif (&closure
->cif
,
1064 closure
->arg_types
) == FFI_OK
1065 && ffi_prep_closure_loc (&closure
->closure
,
1067 _Jv_ThrowNoClassDefFoundErrorTrampoline
,
1071 closure
->list
.registerClosure (klass
, closure
);
1076 ffi_closure_free (closure
);
1077 java::lang::StringBuffer
*buffer
= new java::lang::StringBuffer();
1078 buffer
->append(JvNewStringLatin1("Error setting up FFI closure"
1079 " for static method of"
1080 " missing class: "));
1081 buffer
->append (_Jv_NewStringUtf8Const(class_name
));
1082 throw new java::lang::InternalError(buffer
->toString());
1087 _Jv_Linker::create_error_method (_Jv_Utf8Const
*, jclass
)
1089 // Codepath for platforms which do not support (or want) libffi.
1090 // You have to accept that it is impossible to provide the name
1091 // of the missing class then.
1092 return (void *) _Jv_ThrowNoClassDefFoundError
;
1094 #endif // USE_LIBFFI && FFI_CLOSURES
1096 // Functions for indirect dispatch (symbolic virtual binding) support.
1098 // There are three tables, atable otable and itable. atable is an
1099 // array of addresses, and otable is an array of offsets, and these
1100 // are used for static and virtual members respectively. itable is an
1101 // array of pairs {address, index} where each address is a pointer to
1104 // {a,o,i}table_syms is an array of _Jv_MethodSymbols. Each such
1105 // symbol is a tuple of {classname, member name, signature}.
1107 // Set this to true to enable debugging of indirect dispatch tables/linking.
1108 static bool debug_link
= false;
1110 // link_symbol_table() scans these two arrays and fills in the
1111 // corresponding atable and otable with the addresses of static
1112 // members and the offsets of virtual members.
1114 // The offset (in bytes) for each resolved method or field is placed
1115 // at the corresponding position in the virtual method offset table
1118 // This must be called while holding the class lock.
1121 _Jv_Linker::link_symbol_table (jclass klass
)
1124 _Jv_MethodSymbol sym
;
1125 if (klass
->otable
== NULL
1126 || klass
->otable
->state
!= 0)
1129 klass
->otable
->state
= 1;
1132 fprintf (stderr
, "Fixing up otable in %s:\n", klass
->name
->chars());
1134 (sym
= klass
->otable_syms
[index
]).class_name
!= NULL
;
1137 jclass target_class
= _Jv_FindClass (sym
.class_name
, klass
->loader
);
1138 _Jv_Method
*meth
= NULL
;
1140 _Jv_Utf8Const
*signature
= sym
.signature
;
1142 maybe_adjust_signature (signature
, special
);
1144 if (target_class
== NULL
)
1145 throw new java::lang::NoClassDefFoundError
1146 (_Jv_NewStringUTF (sym
.class_name
->chars()));
1148 // We're looking for a field or a method, and we can tell
1149 // which is needed by looking at the signature.
1150 if (signature
->first() == '(' && signature
->len() >= 2)
1152 // Looks like someone is trying to invoke an interface method
1153 if (target_class
->isInterface())
1155 using namespace java::lang
;
1156 StringBuffer
*sb
= new StringBuffer();
1157 sb
->append(JvNewStringLatin1("found interface "));
1158 sb
->append(target_class
->getName());
1159 sb
->append(JvNewStringLatin1(" when searching for a class"));
1160 throw new VerifyError(sb
->toString());
1163 // If the target class does not have a vtable_method_count yet,
1164 // then we can't tell the offsets for its methods, so we must lay
1166 wait_for_state(target_class
, JV_STATE_PREPARED
);
1170 meth
= (search_method_in_superclasses
1171 (target_class
, klass
, sym
.name
, signature
,
1172 NULL
, special
== 0));
1174 catch (::java::lang::IllegalAccessError
*e
)
1178 // Every class has a throwNoSuchMethodErrorIndex method that
1179 // it inherits from java.lang.Object. Find its vtable
1181 static int throwNoSuchMethodErrorIndex
;
1182 if (throwNoSuchMethodErrorIndex
== 0)
1185 = _Jv_makeUtf8Const ("throwNoSuchMethodError",
1186 strlen ("throwNoSuchMethodError"));
1188 = _Jv_LookupDeclaredMethod (&java::lang::Object::class$
,
1189 name
, gcj::void_signature
);
1190 throwNoSuchMethodErrorIndex
1191 = _Jv_VTable::idx_to_offset (meth
->index
);
1194 // If we don't find a nonstatic method, insert the
1195 // vtable index of Object.throwNoSuchMethodError().
1196 // This defers the missing method error until an attempt
1197 // is made to execute it.
1202 offset
= _Jv_VTable::idx_to_offset (meth
->index
);
1204 offset
= throwNoSuchMethodErrorIndex
;
1207 JvFail ("Bad method index");
1208 JvAssert (meth
->index
< target_class
->vtable_method_count
);
1210 klass
->otable
->offsets
[index
] = offset
;
1214 fprintf (stderr
, " offsets[%d] = %d (class %s@%p : %s(%s))\n",
1216 (int)klass
->otable
->offsets
[index
],
1217 (const char*)target_class
->name
->chars(),
1219 (const char*)sym
.name
->chars(),
1220 (const char*)signature
->chars());
1226 wait_for_state(target_class
, JV_STATE_PREPARED
);
1228 _Jv_Field
*the_field
= NULL
;
1231 the_field
= find_field (klass
, target_class
, &found_class
,
1232 sym
.name
, signature
);
1233 if ((the_field
->flags
& java::lang::reflect::Modifier::STATIC
))
1234 throw new java::lang::IncompatibleClassChangeError
;
1236 klass
->otable
->offsets
[index
] = the_field
->u
.boffset
;
1238 catch (java::lang::NoSuchFieldError
*err
)
1240 klass
->otable
->offsets
[index
] = 0;
1246 if (klass
->atable
== NULL
|| klass
->atable
->state
!= 0)
1249 klass
->atable
->state
= 1;
1252 (sym
= klass
->atable_syms
[index
]).class_name
!= NULL
;
1255 jclass target_class
=
1256 _Jv_FindClassNoException (sym
.class_name
, klass
->loader
);
1258 _Jv_Method
*meth
= NULL
;
1260 _Jv_Utf8Const
*signature
= sym
.signature
;
1262 maybe_adjust_signature (signature
, special
);
1264 // ??? Setting this pointer to null will at least get us a
1265 // NullPointerException
1266 klass
->atable
->addresses
[index
] = NULL
;
1268 bool use_error_method
= false;
1270 // If the target class is missing we prepare a function call
1271 // that throws a NoClassDefFoundError and store the address of
1272 // that newly prepared method in the atable. The user can run
1273 // code in classes where the missing class is part of the
1274 // execution environment as long as it is never referenced.
1275 if (target_class
== NULL
)
1276 use_error_method
= true;
1277 // We're looking for a static field or a static method, and we
1278 // can tell which is needed by looking at the signature.
1279 else if (signature
->first() == '(' && signature
->len() >= 2)
1281 // If the target class does not have a vtable_method_count yet,
1282 // then we can't tell the offsets for its methods, so we must lay
1284 wait_for_state (target_class
, JV_STATE_PREPARED
);
1286 // Interface methods cannot have bodies.
1287 if (target_class
->isInterface())
1289 using namespace java::lang
;
1290 StringBuffer
*sb
= new StringBuffer();
1291 sb
->append(JvNewStringLatin1("class "));
1292 sb
->append(target_class
->getName());
1293 sb
->append(JvNewStringLatin1(" is an interface: "
1295 throw new VerifyError(sb
->toString());
1300 meth
= (search_method_in_superclasses
1301 (target_class
, klass
, sym
.name
, signature
,
1302 NULL
, special
== 0));
1304 catch (::java::lang::IllegalAccessError
*e
)
1310 if (meth
->ncode
) // Maybe abstract?
1312 klass
->atable
->addresses
[index
] = meth
->ncode
;
1314 fprintf (stderr
, " addresses[%d] = %p (class %s@%p : %s(%s))\n",
1316 &klass
->atable
->addresses
[index
],
1317 (const char*)target_class
->name
->chars(),
1319 (const char*)sym
.name
->chars(),
1320 (const char*)signature
->chars());
1324 use_error_method
= true;
1326 if (use_error_method
)
1327 klass
->atable
->addresses
[index
]
1328 = create_error_method(sym
.class_name
, klass
);
1334 // Try fields only if the target class exists.
1335 if (target_class
!= NULL
)
1337 wait_for_state(target_class
, JV_STATE_PREPARED
);
1339 _Jv_Field
*the_field
= find_field (klass
, target_class
, &found_class
,
1340 sym
.name
, signature
);
1341 if ((the_field
->flags
& java::lang::reflect::Modifier::STATIC
))
1342 klass
->atable
->addresses
[index
] = the_field
->u
.addr
;
1344 throw new java::lang::IncompatibleClassChangeError
;
1349 if (klass
->itable
== NULL
1350 || klass
->itable
->state
!= 0)
1353 klass
->itable
->state
= 1;
1356 (sym
= klass
->itable_syms
[index
]).class_name
!= NULL
;
1359 jclass target_class
= _Jv_FindClass (sym
.class_name
, klass
->loader
);
1361 _Jv_Utf8Const
*signature
= sym
.signature
;
1363 maybe_adjust_signature (signature
, special
);
1368 wait_for_state(target_class
, JV_STATE_LOADED
);
1369 bool found
= _Jv_getInterfaceMethod (target_class
, cls
, i
,
1370 sym
.name
, signature
);
1374 klass
->itable
->addresses
[index
* 2] = cls
;
1375 klass
->itable
->addresses
[index
* 2 + 1] = (void *)(unsigned long) i
;
1378 fprintf (stderr
, " interfaces[%d] = %p (interface %s@%p : %s(%s))\n",
1380 klass
->itable
->addresses
[index
* 2],
1381 (const char*)cls
->name
->chars(),
1383 (const char*)sym
.name
->chars(),
1384 (const char*)signature
->chars());
1385 fprintf (stderr
, " [%d] = offset %d\n",
1387 (int)(unsigned long)klass
->itable
->addresses
[index
* 2 + 1]);
1392 throw new java::lang::IncompatibleClassChangeError
;
1397 // For each catch_record in the list of caught classes, fill in the
1400 _Jv_Linker::link_exception_table (jclass self
)
1402 struct _Jv_CatchClass
*catch_record
= self
->catch_classes
;
1403 if (!catch_record
|| catch_record
->classname
)
1406 while (catch_record
->classname
)
1411 = _Jv_FindClass (catch_record
->classname
,
1412 self
->getClassLoaderInternal ());
1413 *catch_record
->address
= target_class
;
1415 catch (::java::lang::Throwable
*t
)
1417 // FIXME: We need to do something better here.
1418 *catch_record
->address
= 0;
1422 self
->catch_classes
->classname
= (_Jv_Utf8Const
*)-1;
1425 // Set itable method indexes for members of interface IFACE.
1427 _Jv_Linker::layout_interface_methods (jclass iface
)
1429 if (! iface
->isInterface())
1432 // itable indexes start at 1.
1433 // FIXME: Static initalizers currently get a NULL placeholder entry in the
1434 // itable so they are also assigned an index here.
1435 for (int i
= 0; i
< iface
->method_count
; i
++)
1436 iface
->methods
[i
].index
= i
+ 1;
1439 // Prepare virtual method declarations in KLASS, and any superclasses
1440 // as required, by determining their vtable index, setting
1441 // method->index, and finally setting the class's vtable_method_count.
1442 // Must be called with the lock for KLASS held.
1444 _Jv_Linker::layout_vtable_methods (jclass klass
)
1446 if (klass
->vtable
!= NULL
|| klass
->isInterface()
1447 || klass
->vtable_method_count
!= -1)
1450 jclass superclass
= klass
->getSuperclass();
1452 if (superclass
!= NULL
&& superclass
->vtable_method_count
== -1)
1454 JvSynchronize
sync (superclass
);
1455 layout_vtable_methods (superclass
);
1458 int index
= (superclass
== NULL
? 0 : superclass
->vtable_method_count
);
1460 for (int i
= 0; i
< klass
->method_count
; ++i
)
1462 _Jv_Method
*meth
= &klass
->methods
[i
];
1463 _Jv_Method
*super_meth
= NULL
;
1465 if (! _Jv_isVirtualMethod (meth
))
1468 if (superclass
!= NULL
)
1471 super_meth
= _Jv_LookupDeclaredMethod (superclass
, meth
->name
,
1472 meth
->signature
, &declarer
);
1473 // See if this method actually overrides the other method
1477 if (! _Jv_isVirtualMethod (super_meth
)
1478 || ! _Jv_CheckAccess (klass
, declarer
,
1479 super_meth
->accflags
))
1481 else if ((super_meth
->accflags
1482 & java::lang::reflect::Modifier::FINAL
) != 0)
1484 using namespace java::lang
;
1485 StringBuffer
*sb
= new StringBuffer();
1486 sb
->append(JvNewStringLatin1("method "));
1487 sb
->append(_Jv_GetMethodString(klass
, meth
));
1488 sb
->append(JvNewStringLatin1(" overrides final method "));
1489 sb
->append(_Jv_GetMethodString(declarer
, super_meth
));
1490 throw new VerifyError(sb
->toString());
1492 else if (declarer
->loader
!= klass
->loader
)
1495 check_loading_constraints (meth
, klass
, declarer
);
1501 meth
->index
= super_meth
->index
;
1503 meth
->index
= index
++;
1506 klass
->vtable_method_count
= index
;
1509 // Set entries in VTABLE for virtual methods declared in KLASS.
1511 _Jv_Linker::set_vtable_entries (jclass klass
, _Jv_VTable
*vtable
)
1513 for (int i
= klass
->method_count
- 1; i
>= 0; i
--)
1515 using namespace java::lang::reflect
;
1517 _Jv_Method
*meth
= &klass
->methods
[i
];
1518 if (meth
->index
== (_Jv_ushort
) -1)
1520 if ((meth
->accflags
& Modifier::ABSTRACT
))
1521 // FIXME: it might be nice to have a libffi trampoline here,
1522 // so we could pass in the method name and other information.
1523 vtable
->set_method(meth
->index
,
1524 (void *) &_Jv_ThrowAbstractMethodError
);
1526 vtable
->set_method(meth
->index
, meth
->ncode
);
1530 // Allocate and lay out the virtual method table for KLASS. This will
1531 // also cause vtables to be generated for any non-abstract
1532 // superclasses, and virtual method layout to occur for any abstract
1533 // superclasses. Must be called with monitor lock for KLASS held.
1535 _Jv_Linker::make_vtable (jclass klass
)
1537 using namespace java::lang::reflect
;
1539 // If the vtable exists, or for interface classes, do nothing. All
1540 // other classes, including abstract classes, need a vtable.
1541 if (klass
->vtable
!= NULL
|| klass
->isInterface())
1544 // Ensure all the `ncode' entries are set.
1545 klass
->engine
->create_ncode(klass
);
1547 // Class must be laid out before we can create a vtable.
1548 if (klass
->vtable_method_count
== -1)
1549 layout_vtable_methods (klass
);
1551 // Allocate the new vtable.
1552 _Jv_VTable
*vtable
= _Jv_VTable::new_vtable (klass
->vtable_method_count
);
1553 klass
->vtable
= vtable
;
1555 // Copy the vtable of the closest superclass.
1556 jclass superclass
= klass
->superclass
;
1558 JvSynchronize
sync (superclass
);
1559 make_vtable (superclass
);
1561 for (int i
= 0; i
< superclass
->vtable_method_count
; ++i
)
1562 vtable
->set_method (i
, superclass
->vtable
->get_method (i
));
1564 // Set the class pointer and GC descriptor.
1565 vtable
->clas
= klass
;
1566 vtable
->gc_descr
= _Jv_BuildGCDescr (klass
);
1568 // For each virtual declared in klass, set new vtable entry or
1569 // override an old one.
1570 set_vtable_entries (klass
, vtable
);
1572 // Note that we don't check for abstract methods here. We used to,
1573 // but there is a JVMS clarification that indicates that a check
1574 // here would be too eager. And, a simple test case confirms this.
1577 // Lay out the class, allocating space for static fields and computing
1578 // offsets of instance fields. The class lock must be held by the
1581 _Jv_Linker::ensure_fields_laid_out (jclass klass
)
1583 if (klass
->size_in_bytes
!= -1)
1586 // Compute the alignment for this type by searching through the
1587 // superclasses and finding the maximum required alignment. We
1588 // could consider caching this in the Class.
1589 int max_align
= __alignof__ (java::lang::Object
);
1590 jclass super
= klass
->getSuperclass();
1591 while (super
!= NULL
)
1593 // Ensure that our super has its super installed before
1595 wait_for_state(super
, JV_STATE_LOADING
);
1596 ensure_fields_laid_out(super
);
1597 int num
= JvNumInstanceFields (super
);
1598 _Jv_Field
*field
= JvGetFirstInstanceField (super
);
1601 int field_align
= get_alignment_from_class (field
->type
);
1602 if (field_align
> max_align
)
1603 max_align
= field_align
;
1607 super
= super
->getSuperclass();
1611 // This is the size of the 'static' non-reference fields.
1612 int non_reference_size
= 0;
1613 // This is the size of the 'static' reference fields. We count
1614 // these separately to make it simpler for the GC to scan them.
1615 int reference_size
= 0;
1617 // Although java.lang.Object is never interpreted, an interface can
1618 // have a null superclass. Note that we have to lay out an
1619 // interface because it might have static fields.
1620 if (klass
->superclass
)
1621 instance_size
= klass
->superclass
->size();
1623 instance_size
= java::lang::Object::class$
.size();
1625 klass
->engine
->allocate_field_initializers (klass
);
1627 for (int i
= 0; i
< klass
->field_count
; i
++)
1632 _Jv_Field
*field
= &klass
->fields
[i
];
1634 if (! field
->isRef ())
1636 // It is safe to resolve the field here, since it's a
1637 // primitive class, which does not cause loading to happen.
1638 resolve_field (field
, klass
->loader
);
1639 field_size
= field
->type
->size ();
1640 field_align
= get_alignment_from_class (field
->type
);
1644 field_size
= sizeof (jobject
);
1645 field_align
= __alignof__ (jobject
);
1648 field
->bsize
= field_size
;
1650 if ((field
->flags
& java::lang::reflect::Modifier::STATIC
))
1652 if (field
->u
.addr
== NULL
)
1654 // This computes an offset into a region we'll allocate
1655 // shortly, and then adds this offset to the start
1659 reference_size
= ROUND (reference_size
, field_align
);
1660 field
->u
.boffset
= reference_size
;
1661 reference_size
+= field_size
;
1665 non_reference_size
= ROUND (non_reference_size
, field_align
);
1666 field
->u
.boffset
= non_reference_size
;
1667 non_reference_size
+= field_size
;
1673 instance_size
= ROUND (instance_size
, field_align
);
1674 field
->u
.boffset
= instance_size
;
1675 instance_size
+= field_size
;
1676 if (field_align
> max_align
)
1677 max_align
= field_align
;
1681 if (reference_size
!= 0 || non_reference_size
!= 0)
1682 klass
->engine
->allocate_static_fields (klass
, reference_size
,
1683 non_reference_size
);
1685 // Set the instance size for the class. Note that first we round it
1686 // to the alignment required for this object; this keeps us in sync
1687 // with our current ABI.
1688 instance_size
= ROUND (instance_size
, max_align
);
1689 klass
->size_in_bytes
= instance_size
;
1692 // This takes the class to state JV_STATE_LINKED. The class lock must
1693 // be held when calling this.
1695 _Jv_Linker::ensure_class_linked (jclass klass
)
1697 if (klass
->state
>= JV_STATE_LINKED
)
1700 int state
= klass
->state
;
1703 // Short-circuit, so that mutually dependent classes are ok.
1704 klass
->state
= JV_STATE_LINKED
;
1706 _Jv_Constants
*pool
= &klass
->constants
;
1708 // Compiled classes require that their class constants be
1709 // resolved here. However, interpreted classes need their
1710 // constants to be resolved lazily. If we resolve an
1711 // interpreted class' constants eagerly, we can end up with
1712 // spurious IllegalAccessErrors when the constant pool contains
1713 // a reference to a class we can't access. This can validly
1714 // occur in an obscure case involving the InnerClasses
1716 if (! _Jv_IsInterpretedClass (klass
))
1718 // Resolve class constants first, since other constant pool
1719 // entries may rely on these.
1720 for (int index
= 1; index
< pool
->size
; ++index
)
1722 if (pool
->tags
[index
] == JV_CONSTANT_Class
)
1723 // Lazily resolve the entries.
1724 resolve_pool_entry (klass
, index
, true);
1728 // Resolve the remaining constant pool entries.
1729 for (int index
= 1; index
< pool
->size
; ++index
)
1731 if (pool
->tags
[index
] == JV_CONSTANT_String
)
1735 str
= _Jv_NewStringUtf8Const (pool
->data
[index
].utf8
);
1736 pool
->data
[index
].o
= str
;
1737 pool
->tags
[index
] |= JV_CONSTANT_ResolvedFlag
;
1741 if (klass
->engine
->need_resolve_string_fields())
1743 jfieldID f
= JvGetFirstStaticField (klass
);
1744 for (int n
= JvNumStaticFields (klass
); n
> 0; --n
)
1746 int mod
= f
->getModifiers ();
1747 // If we have a static String field with a non-null initial
1748 // value, we know it points to a Utf8Const.
1750 // Finds out whether we have to initialize a String without the
1751 // need to resolve the field.
1752 if ((f
->isResolved()
1753 ? (f
->type
== &java::lang::String::class$
)
1754 : _Jv_equalUtf8Classnames((_Jv_Utf8Const
*) f
->type
,
1755 java::lang::String::class$
.name
))
1756 && (mod
& java::lang::reflect::Modifier::STATIC
) != 0)
1758 jstring
*strp
= (jstring
*) f
->u
.addr
;
1760 *strp
= _Jv_NewStringUtf8Const ((_Jv_Utf8Const
*) *strp
);
1762 f
= f
->getNextField ();
1766 klass
->notifyAll ();
1768 _Jv_PushClass (klass
);
1770 catch (java::lang::Throwable
*t
)
1772 klass
->state
= state
;
1777 // This ensures that symbolic superclass and superinterface references
1778 // are resolved for the indicated class. This must be called with the
1781 _Jv_Linker::ensure_supers_installed (jclass klass
)
1783 resolve_class_ref (klass
, &klass
->superclass
);
1784 // An interface won't have a superclass.
1785 if (klass
->superclass
)
1786 wait_for_state (klass
->superclass
, JV_STATE_LOADING
);
1788 for (int i
= 0; i
< klass
->interface_count
; ++i
)
1790 resolve_class_ref (klass
, &klass
->interfaces
[i
]);
1791 wait_for_state (klass
->interfaces
[i
], JV_STATE_LOADING
);
1795 // This adds missing `Miranda methods' to a class.
1797 _Jv_Linker::add_miranda_methods (jclass base
, jclass iface_class
)
1799 // Note that at this point, all our supers, and the supers of all
1800 // our superclasses and superinterfaces, will have been installed.
1802 for (int i
= 0; i
< iface_class
->interface_count
; ++i
)
1804 jclass interface
= iface_class
->interfaces
[i
];
1806 for (int j
= 0; j
< interface
->method_count
; ++j
)
1808 _Jv_Method
*meth
= &interface
->methods
[j
];
1809 // Don't bother with <clinit>.
1810 if (meth
->name
->first() == '<')
1812 _Jv_Method
*new_meth
= _Jv_LookupDeclaredMethod (base
, meth
->name
,
1816 // We assume that such methods are very unlikely, so we
1817 // just reallocate the method array each time one is
1818 // found. This greatly simplifies the searching --
1819 // otherwise we have to make sure that each such method
1820 // found is really unique among all superinterfaces.
1821 int new_count
= base
->method_count
+ 1;
1823 = (_Jv_Method
*) _Jv_AllocRawObj (sizeof (_Jv_Method
)
1825 memcpy (new_m
, base
->methods
,
1826 sizeof (_Jv_Method
) * base
->method_count
);
1829 new_m
[base
->method_count
] = *meth
;
1830 new_m
[base
->method_count
].index
= (_Jv_ushort
) -1;
1831 new_m
[base
->method_count
].accflags
1832 |= java::lang::reflect::Modifier::INVISIBLE
;
1834 base
->methods
= new_m
;
1835 base
->method_count
= new_count
;
1839 wait_for_state (interface
, JV_STATE_LOADED
);
1840 add_miranda_methods (base
, interface
);
1844 // This ensures that the class' method table is "complete". This must
1845 // be called with the class lock held.
1847 _Jv_Linker::ensure_method_table_complete (jclass klass
)
1849 if (klass
->vtable
!= NULL
)
1852 // We need our superclass to have its own Miranda methods installed.
1853 if (! klass
->isInterface())
1854 wait_for_state (klass
->getSuperclass (), JV_STATE_LOADED
);
1856 // A class might have so-called "Miranda methods". This is a method
1857 // that is declared in an interface and not re-declared in an
1858 // abstract class. Some compilers don't emit declarations for such
1859 // methods in the class; this will give us problems since we expect
1860 // a declaration for any method requiring a vtable entry. We handle
1861 // this here by searching for such methods and constructing new
1862 // internal declarations for them. Note that we do this
1863 // unconditionally, and not just for abstract classes, to correctly
1864 // account for cases where a class is modified to be concrete and
1865 // still incorrectly inherits an abstract method.
1866 int pre_count
= klass
->method_count
;
1867 add_miranda_methods (klass
, klass
);
1869 // Let the execution engine know that we've added methods.
1870 if (klass
->method_count
!= pre_count
)
1871 klass
->engine
->post_miranda_hook(klass
);
1874 // Verify a class. Must be called with class lock held.
1876 _Jv_Linker::verify_class (jclass klass
)
1878 klass
->engine
->verify(klass
);
1881 // Check the assertions contained in the type assertion table for KLASS.
1882 // This is the equivilent of bytecode verification for native, BC-ABI code.
1884 _Jv_Linker::verify_type_assertions (jclass klass
)
1887 fprintf (stderr
, "Evaluating type assertions for %s:\n",
1888 klass
->name
->chars());
1890 if (klass
->assertion_table
== NULL
)
1893 for (int i
= 0;; i
++)
1895 int assertion_code
= klass
->assertion_table
[i
].assertion_code
;
1896 _Jv_Utf8Const
*op1
= klass
->assertion_table
[i
].op1
;
1897 _Jv_Utf8Const
*op2
= klass
->assertion_table
[i
].op2
;
1899 if (assertion_code
== JV_ASSERT_END_OF_TABLE
)
1901 else if (assertion_code
== JV_ASSERT_TYPES_COMPATIBLE
)
1905 fprintf (stderr
, " code=%i, operand A=%s B=%s\n",
1906 assertion_code
, op1
->chars(), op2
->chars());
1909 // The operands are class signatures. op1 is the source,
1910 // op2 is the target.
1911 jclass cl1
= _Jv_FindClassFromSignature (op1
->chars(),
1912 klass
->getClassLoaderInternal());
1913 jclass cl2
= _Jv_FindClassFromSignature (op2
->chars(),
1914 klass
->getClassLoaderInternal());
1916 // If the class doesn't exist, ignore the assertion. An exception
1917 // will be thrown later if an attempt is made to actually
1918 // instantiate the class.
1919 if (cl1
== NULL
|| cl2
== NULL
)
1922 if (! _Jv_IsAssignableFromSlow (cl1
, cl2
))
1924 jstring s
= JvNewStringUTF ("Incompatible types: In class ");
1925 s
= s
->concat (klass
->getName());
1926 s
= s
->concat (JvNewStringUTF (": "));
1927 s
= s
->concat (cl1
->getName());
1928 s
= s
->concat (JvNewStringUTF (" is not assignable to "));
1929 s
= s
->concat (cl2
->getName());
1930 throw new java::lang::VerifyError (s
);
1933 else if (assertion_code
== JV_ASSERT_IS_INSTANTIABLE
)
1935 // TODO: Implement this.
1937 // Unknown assertion codes are ignored, for forwards-compatibility.
1942 _Jv_Linker::print_class_loaded (jclass klass
)
1944 char *codesource
= NULL
;
1945 if (klass
->protectionDomain
!= NULL
)
1947 java::security::CodeSource
*cs
1948 = klass
->protectionDomain
->getCodeSource();
1951 jstring css
= cs
->toString();
1952 int len
= JvGetStringUTFLength(css
);
1953 codesource
= (char *) _Jv_AllocBytes(len
+ 1);
1954 JvGetStringUTFRegion(css
, 0, css
->length(), codesource
);
1955 codesource
[len
] = '\0';
1958 if (codesource
== NULL
)
1959 codesource
= (char *) "<no code source>";
1962 if (_Jv_IsInterpretedClass (klass
))
1964 else if (_Jv_IsBinaryCompatibilityABI (klass
))
1965 abi
= "BC-compiled";
1967 abi
= "pre-compiled";
1969 fprintf (stderr
, "[Loaded (%s) %s from %s]\n", abi
, klass
->name
->chars(),
1973 // FIXME: mention invariants and stuff.
1975 _Jv_Linker::wait_for_state (jclass klass
, int state
)
1977 if (klass
->state
>= state
)
1980 java::lang::Thread
*self
= java::lang::Thread::currentThread();
1983 JvSynchronize
sync (klass
);
1985 // This is similar to the strategy for class initialization. If we
1986 // already hold the lock, just leave.
1987 while (klass
->state
<= state
1989 && klass
->thread
!= self
)
1992 java::lang::Thread
*save
= klass
->thread
;
1993 klass
->thread
= self
;
1995 // Allocate memory for static fields and constants.
1996 if (GC_base (klass
) && klass
->fields
&& ! GC_base (klass
->fields
))
1998 jsize count
= klass
->field_count
;
2002 = (_Jv_Field
*) _Jv_AllocRawObj (count
* sizeof (_Jv_Field
));
2003 memcpy ((void*)fields
,
2004 (void*)klass
->fields
,
2005 count
* sizeof (_Jv_Field
));
2006 klass
->fields
= fields
;
2010 // Print some debugging info if requested. Interpreted classes are
2011 // handled in defineclass, so we only need to handle the two
2012 // pre-compiled cases here.
2013 if ((klass
->state
== JV_STATE_COMPILED
2014 || klass
->state
== JV_STATE_PRELOADING
)
2015 && ! _Jv_IsInterpretedClass (klass
))
2017 if (gcj::verbose_class_flag
)
2018 print_class_loaded (klass
);
2019 ++gcj::loadedClasses
;
2024 if (state
>= JV_STATE_LOADING
&& klass
->state
< JV_STATE_LOADING
)
2026 ensure_supers_installed (klass
);
2027 klass
->set_state(JV_STATE_LOADING
);
2030 if (state
>= JV_STATE_LOADED
&& klass
->state
< JV_STATE_LOADED
)
2032 ensure_method_table_complete (klass
);
2033 klass
->set_state(JV_STATE_LOADED
);
2036 if (state
>= JV_STATE_PREPARED
&& klass
->state
< JV_STATE_PREPARED
)
2038 ensure_fields_laid_out (klass
);
2039 make_vtable (klass
);
2040 layout_interface_methods (klass
);
2041 prepare_constant_time_tables (klass
);
2042 klass
->set_state(JV_STATE_PREPARED
);
2045 if (state
>= JV_STATE_LINKED
&& klass
->state
< JV_STATE_LINKED
)
2047 if (gcj::verifyClasses
)
2048 verify_class (klass
);
2050 ensure_class_linked (klass
);
2051 link_exception_table (klass
);
2052 link_symbol_table (klass
);
2053 klass
->set_state(JV_STATE_LINKED
);
2056 catch (java::lang::Throwable
*exc
)
2058 klass
->thread
= save
;
2059 klass
->set_state(JV_STATE_ERROR
);
2063 klass
->thread
= save
;
2065 if (klass
->state
== JV_STATE_ERROR
)
2066 throw new java::lang::LinkageError
;
2070 if (__builtin_expect (klass
->state
== JV_STATE_LINKED
, false)
2071 && state
>= JV_STATE_LINKED
2072 && JVMTI_REQUESTED_EVENT (ClassPrepare
))
2074 JNIEnv
*jni_env
= _Jv_GetCurrentJNIEnv ();
2075 _Jv_JVMTI_PostEvent (JVMTI_EVENT_CLASS_PREPARE
, self
, jni_env
,