libjava/resolve.cc

   1 // resolve.cc - Code for linking and resolving classes and pool entries.
   2
   3 /* Copyright (C) 1999, 2000, 2001  Free Software Foundation
   4
   5    This file is part of libgcj.
   6
   7 This software is copyrighted work licensed under the terms of the
   8 Libgcj License.  Please consult the file "LIBGCJ_LICENSE" for
   9 details.  */
  10
  11 /* Author: Kresten Krab Thorup <krab@gnu.org>  */
  12
  13 #include <config.h>
  14
  15 #include <java-interp.h>
  16
  17 #include <jvm.h>
  18 #include <gcj/cni.h>
  19 #include <string.h>
  20 #include <java-cpool.h>
  21 #include <java/lang/Class.h>
  22 #include <java/lang/String.h>
  23 #include <java/lang/Thread.h>
  24 #include <java/lang/InternalError.h>
  25 #include <java/lang/VirtualMachineError.h>
  26 #include <java/lang/NoSuchFieldError.h>
  27 #include <java/lang/NoSuchMethodError.h>
  28 #include <java/lang/ClassFormatError.h>
  29 #include <java/lang/IllegalAccessError.h>
  30 #include <java/lang/AbstractMethodError.h>
  31 #include <java/lang/ClassNotFoundException.h>
  32 #include <java/lang/IncompatibleClassChangeError.h>
  33 #include <java/lang/reflect/Modifier.h>
  34
  35 void
  36 _Jv_ResolveField (_Jv_Field *field, java::lang::ClassLoader *loader)
  37 {
  38   if (! field->isResolved ())
  39     {
  40       _Jv_Utf8Const *sig = (_Jv_Utf8Const*)field->type;
  41       field->type = _Jv_FindClassFromSignature (sig->data, loader);
  42       field->flags &= ~_Jv_FIELD_UNRESOLVED_FLAG;
  43     }
  44 }
  45
  46 #ifdef INTERPRETER
  47
  48 static void throw_internal_error (char *msg)
  49         __attribute__ ((__noreturn__));
  50 static void throw_class_format_error (jstring msg)
  51         __attribute__ ((__noreturn__));
  52 static void throw_class_format_error (char *msg)
  53         __attribute__ ((__noreturn__));
  54
  55 // Exceptional return values for _Jv_DetermineVTableIndex
  56 #define METHOD_NOT_THERE (-2)
  57 #define METHOD_INACCESSIBLE (-1)
  58
  59 static int get_alignment_from_class (jclass);
  60
  61 static _Jv_ResolvedMethod*
  62 _Jv_BuildResolvedMethod (_Jv_Method*,
  63                          jclass,
  64                          jboolean,
  65                          jint);
  66
  67
  68 // We need to know the name of a constructor.
  69 static _Jv_Utf8Const *init_name = _Jv_makeUtf8Const ("<init>", 6);
  70
  71 static void throw_incompatible_class_change_error (jstring msg)
  72 {
  73   JvThrow (new java::lang::IncompatibleClassChangeError (msg));
  74 }
  75
  76 _Jv_word
  77 _Jv_ResolvePoolEntry (jclass klass, int index)
  78 {
  79   using namespace java::lang::reflect;
  80
  81   _Jv_Constants *pool = &klass->constants;
  82
  83   if ((pool->tags[index] & JV_CONSTANT_ResolvedFlag) != 0)
  84     return pool->data[index];
  85
  86   switch (pool->tags[index]) {
  87   case JV_CONSTANT_Class:
  88     {
  89       _Jv_Utf8Const *name = pool->data[index].utf8;
  90
  91       jclass found;
  92       if (name->data[0] == '[')
  93         found = _Jv_FindClassFromSignature (&name->data[0],
  94                                             klass->loader);
  95       else
  96         found = _Jv_FindClass (name, klass->loader);
  97
  98       if (! found)
  99         {
 100           jstring str = _Jv_NewStringUTF (name->data);
 101           JvThrow (new java::lang::ClassNotFoundException (str));
 102         }
 103
 104       if ((found->accflags & Modifier::PUBLIC) == Modifier::PUBLIC
 105           || (_Jv_ClassNameSamePackage (found->name,
 106                                         klass->name)))
 107         {
 108           pool->data[index].clazz = found;
 109           pool->tags[index] |= JV_CONSTANT_ResolvedFlag;
 110         }
 111       else
 112         {
 113           JvThrow (new java::lang::IllegalAccessError (found->getName()));
 114         }
 115     }
 116     break;
 117
 118   case JV_CONSTANT_String:
 119     {
 120       jstring str;
 121       str = _Jv_NewStringUtf8Const (pool->data[index].utf8);
 122       pool->data[index].o = str;
 123       pool->tags[index] |= JV_CONSTANT_ResolvedFlag;
 124     }
 125     break;
 126
 127
 128   case JV_CONSTANT_Fieldref:
 129     {
 130       _Jv_ushort class_index, name_and_type_index;
 131       _Jv_loadIndexes (&pool->data[index],
 132                        class_index,
 133                        name_and_type_index);
 134       jclass owner = (_Jv_ResolvePoolEntry (klass, class_index)).clazz;
 135
 136       if (owner != klass)
 137         _Jv_InitClass (owner);
 138
 139       _Jv_ushort name_index, type_index;
 140       _Jv_loadIndexes (&pool->data[name_and_type_index],
 141                        name_index,
 142                        type_index);
 143
 144       _Jv_Utf8Const *field_name = pool->data[name_index].utf8;
 145       _Jv_Utf8Const *field_type_name = pool->data[type_index].utf8;
 146
 147       // FIXME: The implementation of this function
 148       // (_Jv_FindClassFromSignature) will generate an instance of
 149       // _Jv_Utf8Const for each call if the field type is a class name
 150       // (Lxx.yy.Z;).  This may be too expensive to do for each and
 151       // every fieldref being resolved.  For now, we fix the problem by
 152       // only doing it when we have a loader different from the class
 153       // declaring the field.
 154
 155       jclass field_type = 0;
 156
 157       if (owner->loader != klass->loader)
 158         field_type = _Jv_FindClassFromSignature (field_type_name->data,
 159                                                  klass->loader);
 160
 161       _Jv_Field* the_field = 0;
 162
 163       for (jclass cls = owner; cls != 0; cls = cls->getSuperclass ())
 164         {
 165           for (int i = 0;  i < cls->field_count;  i++)
 166             {
 167               _Jv_Field *field = &cls->fields[i];
 168               if (! _Jv_equalUtf8Consts (field->name, field_name))
 169                 continue;
 170
 171               // now, check field access.
 172
 173               if (   (cls == klass)
 174                   || ((field->flags & Modifier::PUBLIC) != 0)
 175                   || (((field->flags & Modifier::PROTECTED) != 0)
 176                       && cls->isAssignableFrom (klass))
 177                   || (((field->flags & Modifier::PRIVATE) == 0)
 178                       && _Jv_ClassNameSamePackage (cls->name,
 179                                                    klass->name)))
 180                 {
 181                   /* resove the field using the class' own loader
 182                      if necessary */
 183
 184                   if (!field->isResolved ())
 185                     _Jv_ResolveField (field, cls->loader);
 186
 187                   if (field_type != 0 && field->type != field_type)
 188                     JvThrow
 189                       (new java::lang::LinkageError
 190                        (JvNewStringLatin1
 191                         ("field type mismatch with different loaders")));
 192
 193                   the_field = field;
 194                   goto end_of_field_search;
 195                 }
 196               else
 197                 {
 198                   JvThrow (new java::lang::IllegalAccessError);
 199                 }
 200             }
 201         }
 202
 203     end_of_field_search:
 204       if (the_field == 0)
 205         {
 206           jstring msg = JvNewStringLatin1 ("field ");
 207           msg = msg->concat (owner->getName ());
 208           msg = msg->concat (JvNewStringLatin1("."));
 209           msg = msg->concat (_Jv_NewStringUTF (field_name->data));
 210           msg = msg->concat (JvNewStringLatin1(" was not found."));
 211           throw_incompatible_class_change_error (msg);
 212         }
 213
 214       pool->data[index].field = the_field;
 215       pool->tags[index] |= JV_CONSTANT_ResolvedFlag;
 216     }
 217     break;
 218
 219   case JV_CONSTANT_Methodref:
 220   case JV_CONSTANT_InterfaceMethodref:
 221     {
 222       _Jv_ushort class_index, name_and_type_index;
 223       _Jv_loadIndexes (&pool->data[index],
 224                        class_index,
 225                        name_and_type_index);
 226       jclass owner = (_Jv_ResolvePoolEntry (klass, class_index)).clazz;
 227
 228       if (owner != klass)
 229         _Jv_InitClass (owner);
 230
 231       _Jv_ushort name_index, type_index;
 232       _Jv_loadIndexes (&pool->data[name_and_type_index],
 233                        name_index,
 234                        type_index);
 235
 236       _Jv_Utf8Const *method_name = pool->data[name_index].utf8;
 237       _Jv_Utf8Const *method_signature = pool->data[type_index].utf8;
 238
 239       int vtable_index = -1;
 240       _Jv_Method *the_method = 0;
 241       jclass found_class = 0;
 242
 243       // First search the class itself.
 244       the_method = _Jv_SearchMethodInClass (owner, klass,
 245                    method_name, method_signature);
 246
 247       if (the_method != 0)
 248         {
 249           found_class = owner;
 250           goto end_of_method_search;
 251         }
 252
 253       // If we are resolving an interface method, search the interface's
 254       // superinterfaces (A superinterface is not an interface's superclass -
 255       // a superinterface is implemented by the interface).
 256       if (pool->tags[index] == JV_CONSTANT_InterfaceMethodref)
 257         {
 258           _Jv_ifaces ifaces;
 259           ifaces.count = 0;
 260           ifaces.len = 4;
 261           ifaces.list = (jclass *) _Jv_Malloc (ifaces.len * sizeof (jclass *));
 262
 263           _Jv_GetInterfaces (owner, &ifaces);
 264
 265           for (int i=0; i < ifaces.count; i++)
 266             {
 267               jclass cls = ifaces.list[i];
 268               the_method = _Jv_SearchMethodInClass (cls, klass, method_name,
 269                                                     method_signature);
 270               if (the_method != 0)
 271                 {
 272                   found_class = cls;
 273                   break;
 274                 }
 275             }
 276
 277           _Jv_Free (ifaces.list);
 278
 279           if (the_method != 0)
 280             goto end_of_method_search;
 281         }
 282
 283       // Finally, search superclasses.
 284       for (jclass cls = owner->getSuperclass (); cls != 0;
 285            cls = cls->getSuperclass ())
 286         {
 287           the_method = _Jv_SearchMethodInClass (cls, klass,
 288                        method_name, method_signature);
 289           if (the_method != 0)
 290             {
 291               found_class = cls;
 292               break;
 293             }
 294         }
 295
 296     end_of_method_search:
 297
 298       // FIXME: if (cls->loader != klass->loader), then we
 299       // must actually check that the types of arguments
 300       // correspond.  That is, for each argument type, and
 301       // the return type, doing _Jv_FindClassFromSignature
 302       // with either loader should produce the same result,
 303       // i.e., exactly the same jclass object. JVMS 5.4.3.3
 304
 305       if (pool->tags[index] == JV_CONSTANT_InterfaceMethodref)
 306         vtable_index = -1;
 307       else
 308         vtable_index = _Jv_DetermineVTableIndex
 309           (found_class, method_name, method_signature);
 310
 311       if (vtable_index == METHOD_NOT_THERE)
 312         throw_incompatible_class_change_error
 313           (JvNewStringLatin1 ("method not found"));
 314
 315       if (the_method == 0)
 316         {
 317           jstring msg = JvNewStringLatin1 ("method ");
 318           msg = msg->concat (owner->getName ());
 319           msg = msg->concat (JvNewStringLatin1("."));
 320           msg = msg->concat (_Jv_NewStringUTF (method_name->data));
 321           msg = msg->concat (JvNewStringLatin1(" was not found."));
 322           JvThrow(new java::lang::NoSuchMethodError (msg));
 323         }
 324
 325       pool->data[index].rmethod =
 326         _Jv_BuildResolvedMethod(the_method,
 327                                 found_class,
 328                                 (the_method->accflags & Modifier::STATIC) != 0,
 329                                 vtable_index);
 330       pool->tags[index] |= JV_CONSTANT_ResolvedFlag;
 331     }
 332     break;
 333
 334   }
 335
 336   return pool->data[index];
 337 }
 338
 339 // Find a method declared in the cls that is referenced from klass and
 340 // perform access checks.
 341 _Jv_Method *
 342 _Jv_SearchMethodInClass (jclass cls, jclass klass,
 343                          _Jv_Utf8Const *method_name,
 344                          _Jv_Utf8Const *method_signature)
 345 {
 346   using namespace java::lang::reflect;
 347
 348   for (int i = 0;  i < cls->method_count;  i++)
 349     {
 350       _Jv_Method *method = &cls->methods[i];
 351       if (   (!_Jv_equalUtf8Consts (method->name,
 352                                     method_name))
 353           || (!_Jv_equalUtf8Consts (method->signature,
 354                                     method_signature)))
 355         continue;
 356
 357       if (cls == klass
 358           || ((method->accflags & Modifier::PUBLIC) != 0)
 359           || (((method->accflags & Modifier::PROTECTED) != 0)
 360               && cls->isAssignableFrom (klass))
 361           || (((method->accflags & Modifier::PRIVATE) == 0)
 362               && _Jv_ClassNameSamePackage (cls->name,
 363                                            klass->name)))
 364         {
 365           return method;
 366         }
 367       else
 368         {
 369           JvThrow (new java::lang::IllegalAccessError);
 370         }
 371     }
 372   return 0;
 373 }
 374
 375 /** FIXME: this is a terribly inefficient algorithm!  It would improve
 376     things if compiled classes to know vtable offset, and _Jv_Method had
 377     a field for this.
 378
 379     Returns METHOD_NOT_THERE if this class does not declare the given method.
 380     Returns METHOD_INACCESSIBLE if the given method does not appear in the
 381                 vtable, i.e., it is static, private, final or a constructor.
 382     Otherwise, returns the vtable index.  */
 383 int
 384 _Jv_DetermineVTableIndex (jclass klass,
 385                           _Jv_Utf8Const *name,
 386                           _Jv_Utf8Const *signature)
 387 {
 388   using namespace java::lang::reflect;
 389
 390   jclass super_class = klass->getSuperclass ();
 391
 392   if (super_class != NULL)
 393     {
 394       int prev = _Jv_DetermineVTableIndex (super_class,
 395                                            name,
 396                                            signature);
 397       if (prev != METHOD_NOT_THERE)
 398         return prev;
 399     }
 400
 401   /* at this point, we know that the super-class does not declare
 402    * the method.  Otherwise, the above call would have found it, and
 403    * determined the result of this function (-1 or some positive
 404    * number).
 405    */
 406
 407   _Jv_Method *meth = _Jv_GetMethodLocal (klass, name, signature);
 408
 409   /* now, if we do not declare this method, return zero */
 410   if (meth == NULL)
 411     return METHOD_NOT_THERE;
 412
 413   /* so now, we know not only that the super class does not declare the
 414    * method, but we do!  So, this is a first declaration of the method. */
 415
 416   /* now, the checks for things that are declared in this class, but do
 417    * not go into the vtable.  There are three cases.
 418    * 1) the method is static, private or final
 419    * 2) the class itself is final, or
 420    * 3) it is the method <init>
 421    */
 422
 423   if ((meth->accflags & (Modifier::STATIC
 424                          | Modifier::PRIVATE
 425                          | Modifier::FINAL)) != 0
 426       || (klass->accflags & Modifier::FINAL) != 0
 427       || _Jv_equalUtf8Consts (name, init_name))
 428     return METHOD_INACCESSIBLE;
 429
 430   /* reaching this point, we know for sure, that the method in question
 431    * will be in the vtable.  The question is where. */
 432
 433   /* the base offset, is where we will start assigning vtable
 434    * indexes for this class.  It is 0 for base classes
 435    * and for non-base classes it is the
 436    * number of entries in the super class' vtable. */
 437
 438   int base_offset;
 439   if (super_class == 0)
 440     base_offset = 0;
 441   else
 442     base_offset = super_class->vtable_method_count;
 443
 444   /* we will consider methods 0..this_method_index-1.  And for each one,
 445    * determine if it is new (i.e., if it appears in the super class),
 446    * and if it should go in the vtable.  If so, increment base_offset */
 447
 448   int this_method_index = meth - (&klass->methods[0]);
 449
 450   for (int i = 0; i < this_method_index; i++)
 451     {
 452       _Jv_Method *m = &klass->methods[i];
 453
 454       /* fist some checks for things that surely do not go in the
 455        * vtable */
 456
 457       if ((m->accflags & (Modifier::STATIC | Modifier::PRIVATE)) != 0)
 458         continue;
 459       if (_Jv_equalUtf8Consts (m->name, init_name))
 460         continue;
 461
 462       /* Then, we need to know if this method appears in the
 463          superclass. (This is where this function gets expensive) */
 464       _Jv_Method *sm = _Jv_LookupDeclaredMethod (super_class,
 465                                                  m->name,
 466                                                  m->signature);
 467
 468       /* if it was somehow declared in the superclass, skip this */
 469       if (sm != NULL)
 470         continue;
 471
 472       /* but if it is final, and not declared in the super class,
 473        * then we also skip it */
 474       if ((m->accflags & Modifier::FINAL) != 0)
 475         continue;
 476
 477       /* finally, we can assign the index of this method */
 478       /* m->vtable_index = base_offset */
 479       base_offset += 1;
 480     }
 481
 482   return base_offset;
 483 }
 484
 485 /* this is installed in place of abstract methods */
 486 static void
 487 _Jv_abstractMethodError ()
 488 {
 489   JvThrow (new java::lang::AbstractMethodError);
 490 }
 491
 492 void
 493 _Jv_PrepareClass(jclass klass)
 494 {
 495   using namespace java::lang::reflect;
 496
 497  /*
 498   * The job of this function is to: 1) assign storage to fields, and 2)
 499   * build the vtable.  static fields are assigned real memory, instance
 500   * fields are assigned offsets.
 501   *
 502   * NOTE: we have a contract with the garbage collector here.  Static
 503   * reference fields must not be resolved, until after they have storage
 504   * assigned which is the check used by the collector to see if it
 505   * should indirect the static field reference and mark the object
 506   * pointed to.
 507   *
 508   * Most fields are resolved lazily (i.e. have their class-type
 509   * assigned) when they are accessed the first time by calling as part
 510   * of _Jv_ResolveField, which is allways called after _Jv_PrepareClass.
 511   * Static fields with initializers are resolved as part of this
 512   * function, as are fields with primitive types.
 513   */
 514
 515   if (! _Jv_IsInterpretedClass (klass))
 516     return;
 517
 518   if (klass->state >= JV_STATE_PREPARED)
 519     return;
 520
 521   // make sure super-class is linked.  This involves taking a lock on
 522   // the super class, so we use the Java method resolveClass, which will
 523   // unlock it properly, should an exception happen.
 524
 525   java::lang::ClassLoader::resolveClass0 (klass->superclass);
 526
 527   _Jv_InterpClass *clz = (_Jv_InterpClass*)klass;
 528
 529   /************ PART ONE: OBJECT LAYOUT ***************/
 530
 531   int instance_size;
 532   int static_size;
 533
 534   // java.lang.Object is never interpreted!
 535   instance_size = clz->superclass->size ();
 536   static_size   = 0;
 537
 538   for (int i = 0; i < clz->field_count; i++)
 539     {
 540       int field_size;
 541       int field_align;
 542
 543       _Jv_Field *field = &clz->fields[i];
 544
 545       if (! field->isRef ())
 546         {
 547           // it's safe to resolve the field here, since it's
 548           // a primitive class, which does not cause loading to happen.
 549           _Jv_ResolveField (field, clz->loader);
 550
 551           field_size = field->type->size ();
 552           field_align = get_alignment_from_class (field->type);
 553         }
 554       else
 555         {
 556           field_size = sizeof (jobject);
 557           field_align = __alignof__ (jobject);
 558         }
 559
 560 #ifndef COMPACT_FIELDS
 561       field->bsize = field_size;
 562 #endif
 563
 564       if (field->flags & Modifier::STATIC)
 565         {
 566           /* this computes an offset into a region we'll allocate
 567              shortly, and then add this offset to the start address */
 568
 569           static_size        = ROUND (static_size, field_align);
 570           field->u.boffset   = static_size;
 571           static_size       += field_size;
 572         }
 573       else
 574         {
 575           instance_size      = ROUND (instance_size, field_align);
 576           field->u.boffset   = instance_size;
 577           instance_size     += field_size;
 578         }
 579     }
 580
 581   // set the instance size for the class
 582   clz->size_in_bytes = instance_size;
 583
 584   // allocate static memory
 585   if (static_size != 0)
 586     {
 587       char *static_data = (char*)_Jv_AllocBytesChecked (static_size);
 588
 589       memset (static_data, 0, static_size);
 590
 591       for (int i = 0; i < clz->field_count; i++)
 592         {
 593           _Jv_Field *field = &clz->fields[i];
 594
 595           if ((field->flags & Modifier::STATIC) != 0)
 596             {
 597               field->u.addr  = static_data + field->u.boffset;
 598
 599               if (clz->field_initializers[i] != 0)
 600                 {
 601                   _Jv_ResolveField (field, clz->loader);
 602                   _Jv_InitField (0, clz, i);
 603                 }
 604             }
 605         }
 606
 607       // now we don't need the field_initializers anymore, so let the
 608       // collector get rid of it!
 609
 610       clz->field_initializers = 0;
 611     }
 612
 613   /************ PART TWO: VTABLE LAYOUT ***************/
 614
 615   /* preparation: build the vtable stubs (even interfaces can)
 616      have code -- for static constructors. */
 617   for (int i = 0; i < clz->method_count; i++)
 618     {
 619       _Jv_MethodBase *imeth = clz->interpreted_methods[i];
 620
 621       if ((clz->methods[i].accflags & Modifier::NATIVE) != 0)
 622         {
 623           // You might think we could use a virtual `ncode' method in
 624           // the _Jv_MethodBase and unify the native and non-native
 625           // cases.  Well, we can't, because we don't allocate these
 626           // objects using `new', and thus they don't get a vtable.
 627           _Jv_JNIMethod *jnim = reinterpret_cast<_Jv_JNIMethod *> (imeth);
 628           clz->methods[i].ncode = jnim->ncode ();
 629         }
 630       else if (imeth != 0)              // it could be abstract
 631         {
 632           _Jv_InterpMethod *im = reinterpret_cast<_Jv_InterpMethod *> (imeth);
 633           clz->methods[i].ncode = im->ncode ();
 634         }
 635     }
 636
 637   if (clz->accflags & Modifier::INTERFACE)
 638     {
 639       clz->state = JV_STATE_PREPARED;
 640       clz->notifyAll ();
 641       return;
 642     }
 643
 644   /* Now onto the actual job: vtable layout.  First, count how many new
 645      methods we have */
 646   int new_method_count = 0;
 647
 648   jclass super_class = clz->getSuperclass ();
 649
 650   if (super_class == 0)
 651     throw_internal_error ("cannot handle interpreted base classes");
 652
 653   for (int i = 0; i < clz->method_count; i++)
 654     {
 655       _Jv_Method *this_meth = &clz->methods[i];
 656
 657       if ((this_meth->accflags & (Modifier::STATIC | Modifier::PRIVATE)) != 0
 658           || _Jv_equalUtf8Consts (this_meth->name, init_name))
 659         {
 660           /* skip this, it doesn't go in the vtable */
 661           continue;
 662         }
 663
 664       _Jv_Method *orig_meth = _Jv_LookupDeclaredMethod (super_class,
 665                                                         this_meth->name,
 666                                                         this_meth->signature);
 667
 668       if (orig_meth == 0)
 669         {
 670           // new methods that are final, also don't go in the vtable
 671           if ((this_meth->accflags & Modifier::FINAL) != 0)
 672             continue;
 673
 674           new_method_count += 1;
 675           continue;
 676         }
 677
 678       if ((orig_meth->accflags & (Modifier::STATIC
 679                                   | Modifier::PRIVATE
 680                                   | Modifier::FINAL)) != 0
 681           || ((orig_meth->accflags & Modifier::ABSTRACT) == 0
 682               && (this_meth->accflags & Modifier::ABSTRACT) != 0
 683               && (klass->accflags & Modifier::ABSTRACT) == 0))
 684         {
 685           clz->state = JV_STATE_ERROR;
 686           clz->notifyAll ();
 687           JvThrow (new java::lang::IncompatibleClassChangeError
 688                            (clz->getName ()));
 689         }
 690
 691       /* FIXME: At this point, if (loader != super_class->loader), we
 692        * need to "impose class loader constraints" for the types
 693        * involved in the signature of this method */
 694     }
 695
 696   /* determine size */
 697   int vtable_count = (super_class->vtable_method_count) + new_method_count;
 698   clz->vtable_method_count = vtable_count;
 699
 700   /* allocate vtable structure */
 701   _Jv_VTable *vtable = _Jv_VTable::new_vtable (vtable_count);
 702   vtable->clas = clz;
 703   vtable->gc_descr = _Jv_BuildGCDescr(clz);
 704
 705   {
 706     jclass effective_superclass = super_class;
 707
 708     /* If super_class is abstract or an interface it has no vtable.
 709        We need to find a real one... */
 710     while (effective_superclass && effective_superclass->vtable == NULL)
 711       effective_superclass = effective_superclass->superclass;
 712
 713     /* copy super class' vtable entries. */
 714     if (effective_superclass && effective_superclass->vtable)
 715       for (int i = 0; i < effective_superclass->vtable_method_count; ++i)
 716         vtable->set_method (i, effective_superclass->vtable->get_method (i));
 717   }
 718
 719   /* now, install our own vtable entries, reprise... */
 720   for (int i = 0; i < clz->method_count; i++)
 721     {
 722       _Jv_Method *this_meth = &clz->methods[i];
 723
 724       int index = _Jv_DetermineVTableIndex (clz,
 725                                             this_meth->name,
 726                                             this_meth->signature);
 727
 728       if (index == METHOD_NOT_THERE)
 729         throw_internal_error ("method now found in own class");
 730
 731       if (index != METHOD_INACCESSIBLE)
 732         {
 733           if (index > clz->vtable_method_count)
 734             throw_internal_error ("vtable problem...");
 735
 736           if (clz->interpreted_methods[i] == 0)
 737             vtable->set_method(index, (void*)&_Jv_abstractMethodError);
 738           else
 739             vtable->set_method(index, this_meth->ncode);
 740         }
 741     }
 742
 743   /* finally, assign the vtable! */
 744   clz->vtable = vtable;
 745
 746   /* wooha! we're done. */
 747   clz->state = JV_STATE_PREPARED;
 748   clz->notifyAll ();
 749 }
 750
 751 /** Do static initialization for fields with a constant initializer */
 752 void
 753 _Jv_InitField (jobject obj, jclass klass, int index)
 754 {
 755   using namespace java::lang::reflect;
 756
 757   if (obj != 0 && klass == 0)
 758     klass = obj->getClass ();
 759
 760   if (!_Jv_IsInterpretedClass (klass))
 761     return;
 762
 763   _Jv_InterpClass *clz = (_Jv_InterpClass*)klass;
 764
 765   _Jv_Field * field = (&clz->fields[0]) + index;
 766
 767   if (index > clz->field_count)
 768     throw_internal_error ("field out of range");
 769
 770   int init = clz->field_initializers[index];
 771   if (init == 0)
 772     return;
 773
 774   _Jv_Constants *pool = &clz->constants;
 775   int tag = pool->tags[init];
 776
 777   if (! field->isResolved ())
 778     throw_internal_error ("initializing unresolved field");
 779
 780   if (obj==0 && ((field->flags & Modifier::STATIC) == 0))
 781     throw_internal_error ("initializing non-static field with no object");
 782
 783   void *addr = 0;
 784
 785   if ((field->flags & Modifier::STATIC) != 0)
 786     addr = (void*) field->u.addr;
 787   else
 788     addr = (void*) (((char*)obj) + field->u.boffset);
 789
 790   switch (tag)
 791     {
 792     case JV_CONSTANT_String:
 793       {
 794         _Jv_MonitorEnter (clz);
 795         jstring str;
 796         str = _Jv_NewStringUtf8Const (pool->data[init].utf8);
 797         pool->data[init].string = str;
 798         pool->tags[init] = JV_CONSTANT_ResolvedString;
 799         _Jv_MonitorExit (clz);
 800       }
 801       /* fall through */
 802
 803     case JV_CONSTANT_ResolvedString:
 804       if (! (field->type == &StringClass
 805              || field->type == &java::lang::Class::class$))
 806         throw_class_format_error ("string initialiser to non-string field");
 807
 808       *(jstring*)addr = pool->data[init].string;
 809       break;
 810
 811     case JV_CONSTANT_Integer:
 812       {
 813         int value = pool->data[init].i;
 814
 815         if (field->type == JvPrimClass (boolean))
 816           *(jboolean*)addr = (jboolean)value;
 817
 818         else if (field->type == JvPrimClass (byte))
 819           *(jbyte*)addr = (jbyte)value;
 820
 821         else if (field->type == JvPrimClass (char))
 822           *(jchar*)addr = (jchar)value;
 823
 824         else if (field->type == JvPrimClass (short))
 825           *(jshort*)addr = (jshort)value;
 826
 827         else if (field->type == JvPrimClass (int))
 828           *(jint*)addr = (jint)value;
 829
 830         else
 831           throw_class_format_error ("erroneous field initializer");
 832       }
 833       break;
 834
 835     case JV_CONSTANT_Long:
 836       if (field->type != JvPrimClass (long))
 837         throw_class_format_error ("erroneous field initializer");
 838
 839       *(jlong*)addr = _Jv_loadLong (&pool->data[init]);
 840       break;
 841
 842     case JV_CONSTANT_Float:
 843       if (field->type != JvPrimClass (float))
 844         throw_class_format_error ("erroneous field initializer");
 845
 846       *(jfloat*)addr = pool->data[init].f;
 847       break;
 848
 849     case JV_CONSTANT_Double:
 850       if (field->type != JvPrimClass (double))
 851         throw_class_format_error ("erroneous field initializer");
 852
 853       *(jdouble*)addr = _Jv_loadDouble (&pool->data[init]);
 854       break;
 855
 856     default:
 857       throw_class_format_error ("erroneous field initializer");
 858     }
 859 }
 860
 861 static int
 862 get_alignment_from_class (jclass klass)
 863 {
 864   if (klass == JvPrimClass (byte))
 865     return  __alignof__ (jbyte);
 866   else if (klass == JvPrimClass (short))
 867     return  __alignof__ (jshort);
 868   else if (klass == JvPrimClass (int))
 869     return  __alignof__ (jint);
 870   else if (klass == JvPrimClass (long))
 871     return  __alignof__ (jlong);
 872   else if (klass == JvPrimClass (boolean))
 873     return  __alignof__ (jboolean);
 874   else if (klass == JvPrimClass (char))
 875     return  __alignof__ (jchar);
 876   else if (klass == JvPrimClass (float))
 877     return  __alignof__ (jfloat);
 878   else if (klass == JvPrimClass (double))
 879     return  __alignof__ (jdouble);
 880   else
 881     return __alignof__ (jobject);
 882 }
 883
 884
 885 inline static unsigned char*
 886 skip_one_type (unsigned char* ptr)
 887 {
 888   int ch = *ptr++;
 889
 890   while (ch == '[')
 891     {
 892       ch = *ptr++;
 893     }
 894
 895   if (ch == 'L')
 896     {
 897       do { ch = *ptr++; } while (ch != ';');
 898     }
 899
 900   return ptr;
 901 }
 902
 903 static ffi_type*
 904 get_ffi_type_from_signature (unsigned char* ptr)
 905 {
 906   switch (*ptr)
 907     {
 908     case 'L':
 909     case '[':
 910       return &ffi_type_pointer;
 911       break;
 912
 913     case 'Z':
 914       // On some platforms a bool is a byte, on others an int.
 915       if (sizeof (jboolean) == sizeof (jbyte))
 916         return &ffi_type_sint8;
 917       else
 918         {
 919           JvAssert (sizeof (jbyte) == sizeof (jint));
 920           return &ffi_type_sint32;
 921         }
 922       break;
 923
 924     case 'B':
 925       return &ffi_type_sint8;
 926       break;
 927
 928     case 'C':
 929       return &ffi_type_uint16;
 930       break;
 931
 932     case 'S':
 933       return &ffi_type_sint16;
 934       break;
 935
 936     case 'I':
 937       return &ffi_type_sint32;
 938       break;
 939
 940     case 'J':
 941       return &ffi_type_sint64;
 942       break;
 943
 944     case 'F':
 945       return &ffi_type_float;
 946       break;
 947
 948     case 'D':
 949       return &ffi_type_double;
 950       break;
 951
 952     case 'V':
 953       return &ffi_type_void;
 954       break;
 955     }
 956
 957   throw_internal_error ("unknown type in signature");
 958 }
 959
 960 /* this function yields the number of actual arguments, that is, if the
 961  * function is non-static, then one is added to the number of elements
 962  * found in the signature */
 963
 964 static int
 965 count_arguments (_Jv_Utf8Const *signature,
 966                  jboolean staticp)
 967 {
 968   unsigned char *ptr = (unsigned char*) signature->data;
 969   int arg_count = staticp ? 0 : 1;
 970
 971   /* first, count number of arguments */
 972
 973   // skip '('
 974   ptr++;
 975
 976   // count args
 977   while (*ptr != ')')
 978     {
 979       ptr = skip_one_type (ptr);
 980       arg_count += 1;
 981     }
 982
 983   return arg_count;
 984 }
 985
 986 /* This beast will build a cif, given the signature.  Memory for
 987  * the cif itself and for the argument types must be allocated by the
 988  * caller.
 989  */
 990
 991 static int
 992 init_cif (_Jv_Utf8Const* signature,
 993           int arg_count,
 994           jboolean staticp,
 995           ffi_cif *cif,
 996           ffi_type **arg_types,
 997           ffi_type **rtype_p)
 998 {
 999   unsigned char *ptr = (unsigned char*) signature->data;
1000
1001   int arg_index = 0;            // arg number
1002   int item_count = 0;           // stack-item count
1003
1004   // setup receiver
1005   if (!staticp)
1006     {
1007       arg_types[arg_index++] = &ffi_type_pointer;
1008       item_count += 1;
1009     }
1010
1011   // skip '('
1012   ptr++;
1013
1014   // assign arg types
1015   while (*ptr != ')')
1016     {
1017       arg_types[arg_index++] = get_ffi_type_from_signature (ptr);
1018
1019       if (*ptr == 'J' || *ptr == 'D')
1020         item_count += 2;
1021       else
1022         item_count += 1;
1023
1024       ptr = skip_one_type (ptr);
1025     }
1026
1027   // skip ')'
1028   ptr++;
1029   ffi_type *rtype = get_ffi_type_from_signature (ptr);
1030
1031   ptr = skip_one_type (ptr);
1032   if (ptr != (unsigned char*)signature->data + signature->length)
1033     throw_internal_error ("did not find end of signature");
1034
1035   if (ffi_prep_cif (cif, FFI_DEFAULT_ABI,
1036                     arg_count, rtype, arg_types) != FFI_OK)
1037     throw_internal_error ("ffi_prep_cif failed");
1038
1039   if (rtype_p != NULL)
1040     *rtype_p = rtype;
1041
1042   return item_count;
1043 }
1044
1045 #if FFI_NATIVE_RAW_API
1046 #   define FFI_PREP_RAW_CLOSURE ffi_prep_raw_closure
1047 #   define FFI_RAW_SIZE ffi_raw_size
1048 #else
1049 #   define FFI_PREP_RAW_CLOSURE ffi_prep_java_raw_closure
1050 #   define FFI_RAW_SIZE ffi_java_raw_size
1051 #endif
1052
1053 /* we put this one here, and not in interpret.cc because it
1054  * calls the utility routines count_arguments
1055  * which are static to this module.  The following struct defines the
1056  * layout we use for the stubs, it's only used in the ncode method. */
1057
1058 typedef struct {
1059   ffi_raw_closure  closure;
1060   ffi_cif   cif;
1061   ffi_type *arg_types[0];
1062 } ncode_closure;
1063
1064 typedef void (*ffi_closure_fun) (ffi_cif*,void*,ffi_raw*,void*);
1065
1066 void *
1067 _Jv_InterpMethod::ncode ()
1068 {
1069   using namespace java::lang::reflect;
1070
1071   if (self->ncode != 0)
1072     return self->ncode;
1073
1074   jboolean staticp = (self->accflags & Modifier::STATIC) != 0;
1075   int arg_count = count_arguments (self->signature, staticp);
1076
1077   ncode_closure *closure =
1078     (ncode_closure*)_Jv_AllocBytesChecked (sizeof (ncode_closure)
1079                                         + arg_count * sizeof (ffi_type*));
1080
1081   init_cif (self->signature,
1082             arg_count,
1083             staticp,
1084             &closure->cif,
1085             &closure->arg_types[0],
1086             NULL);
1087
1088   ffi_closure_fun fun;
1089
1090   args_raw_size = FFI_RAW_SIZE (&closure->cif);
1091
1092   JvAssert ((self->accflags & Modifier::NATIVE) == 0);
1093
1094   if ((self->accflags & Modifier::SYNCHRONIZED) != 0)
1095     {
1096       if (staticp)
1097         fun = (ffi_closure_fun)&_Jv_InterpMethod::run_synch_class;
1098       else
1099         fun = (ffi_closure_fun)&_Jv_InterpMethod::run_synch_object;
1100     }
1101   else
1102     {
1103       fun = (ffi_closure_fun)&_Jv_InterpMethod::run_normal;
1104     }
1105
1106   FFI_PREP_RAW_CLOSURE (&closure->closure,
1107                         &closure->cif,
1108                         fun,
1109                         (void*)this);
1110
1111   self->ncode = (void*)closure;
1112   return self->ncode;
1113 }
1114
1115
1116 void *
1117 _Jv_JNIMethod::ncode ()
1118 {
1119   using namespace java::lang::reflect;
1120
1121   if (self->ncode != 0)
1122     return self->ncode;
1123
1124   jboolean staticp = (self->accflags & Modifier::STATIC) != 0;
1125   int arg_count = count_arguments (self->signature, staticp);
1126
1127   ncode_closure *closure =
1128     (ncode_closure*)_Jv_AllocBytesChecked (sizeof (ncode_closure)
1129                                         + arg_count * sizeof (ffi_type*));
1130
1131   ffi_type *rtype;
1132   init_cif (self->signature,
1133             arg_count,
1134             staticp,
1135             &closure->cif,
1136             &closure->arg_types[0],
1137             &rtype);
1138
1139   ffi_closure_fun fun;
1140
1141   args_raw_size = FFI_RAW_SIZE (&closure->cif);
1142
1143   // Initialize the argument types and CIF that represent the actual
1144   // underlying JNI function.
1145   int extra_args = 1;
1146   if ((self->accflags & Modifier::STATIC))
1147     ++extra_args;
1148   jni_arg_types = (ffi_type **) _Jv_Malloc ((extra_args + arg_count)
1149                                             * sizeof (ffi_type *));
1150   int offset = 0;
1151   jni_arg_types[offset++] = &ffi_type_pointer;
1152   if ((self->accflags & Modifier::STATIC))
1153     jni_arg_types[offset++] = &ffi_type_pointer;
1154   memcpy (&jni_arg_types[offset], &closure->arg_types[0],
1155           arg_count * sizeof (ffi_type *));
1156
1157   if (ffi_prep_cif (&jni_cif, FFI_DEFAULT_ABI,
1158                     extra_args + arg_count, rtype,
1159                     jni_arg_types) != FFI_OK)
1160     throw_internal_error ("ffi_prep_cif failed for JNI function");
1161
1162   JvAssert ((self->accflags & Modifier::NATIVE) != 0);
1163
1164   // FIXME: for now we assume that all native methods for
1165   // interpreted code use JNI.
1166   fun = (ffi_closure_fun) &_Jv_JNIMethod::call;
1167
1168   FFI_PREP_RAW_CLOSURE (&closure->closure,
1169                         &closure->cif,
1170                         fun,
1171                         (void*) this);
1172
1173   self->ncode = (void *) closure;
1174   return self->ncode;
1175 }
1176
1177
1178 /* A _Jv_ResolvedMethod is what is put in the constant pool for a
1179  * MethodRef or InterfacemethodRef.  */
1180 static _Jv_ResolvedMethod*
1181 _Jv_BuildResolvedMethod (_Jv_Method* method,
1182                          jclass      klass,
1183                          jboolean staticp,
1184                          jint vtable_index)
1185 {
1186   int arg_count = count_arguments (method->signature, staticp);
1187
1188   _Jv_ResolvedMethod* result = (_Jv_ResolvedMethod*)
1189     _Jv_AllocBytesChecked (sizeof (_Jv_ResolvedMethod)
1190                            + arg_count*sizeof (ffi_type*));
1191
1192   result->stack_item_count
1193     = init_cif (method->signature,
1194                 arg_count,
1195                 staticp,
1196                 &result->cif,
1197                 &result->arg_types[0],
1198                 NULL);
1199
1200   result->vtable_index        = vtable_index;
1201   result->method              = method;
1202   result->klass               = klass;
1203
1204   return result;
1205 }
1206
1207
1208 static void
1209 throw_class_format_error (jstring msg)
1210 {
1211   if (msg == 0)
1212     JvThrow (new java::lang::ClassFormatError);
1213   else
1214     JvThrow (new java::lang::ClassFormatError (msg));
1215 }
1216
1217 static void
1218 throw_class_format_error (char *msg)
1219 {
1220   throw_class_format_error (JvNewStringLatin1 (msg));
1221 }
1222
1223 static void
1224 throw_internal_error (char *msg)
1225 {
1226   JvThrow
1227     (new java::lang::InternalError (JvNewStringLatin1 (msg)));
1228 }
1229
1230
1231 #endif /* INTERPRETER */