libjava/resolve.cc

   1 // resolve.cc - Code for linking and resolving classes and pool entries.
   2
   3 /* Copyright (C) 1999, 2000  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 #ifdef INTERPRETER
  36
  37 static void throw_internal_error (char *msg)
  38         __attribute__ ((__noreturn__));
  39 static void throw_class_format_error (jstring msg)
  40         __attribute__ ((__noreturn__));
  41 static void throw_class_format_error (char *msg)
  42         __attribute__ ((__noreturn__));
  43
  44 // Exceptional return values for _Jv_DetermineVTableIndex
  45 #define METHOD_NOT_THERE (-2)
  46 #define METHOD_INACCESSIBLE (-1)
  47
  48 static int get_alignment_from_class (jclass);
  49
  50 static _Jv_ResolvedMethod*
  51 _Jv_BuildResolvedMethod (_Jv_Method*,
  52                          jclass,
  53                          jboolean,
  54                          jint);
  55
  56
  57 // We need to know the name of a constructor.
  58 static _Jv_Utf8Const *init_name = _Jv_makeUtf8Const ("<init>", 6);
  59
  60 static void throw_incompatible_class_change_error (jstring msg)
  61 {
  62   JvThrow (new java::lang::IncompatibleClassChangeError (msg));
  63 }
  64
  65 _Jv_word
  66 _Jv_ResolvePoolEntry (jclass klass, int index)
  67 {
  68   using namespace java::lang::reflect;
  69
  70   _Jv_Constants *pool = &klass->constants;
  71
  72   if ((pool->tags[index] & JV_CONSTANT_ResolvedFlag) != 0)
  73     return pool->data[index];
  74
  75   switch (pool->tags[index]) {
  76   case JV_CONSTANT_Class:
  77     {
  78       _Jv_Utf8Const *name = pool->data[index].utf8;
  79
  80       jclass found;
  81       if (name->data[0] == '[')
  82         found = _Jv_FindClassFromSignature (&name->data[0],
  83                                             klass->loader);
  84       else
  85         found = _Jv_FindClass (name, klass->loader);
  86
  87       if (! found)
  88         {
  89           jstring str = _Jv_NewStringUTF (name->data);
  90           JvThrow (new java::lang::ClassNotFoundException (str));
  91         }
  92
  93       if ((found->accflags & Modifier::PUBLIC) == Modifier::PUBLIC
  94           || (_Jv_ClassNameSamePackage (found->name,
  95                                         klass->name)))
  96         {
  97           pool->data[index].clazz = found;
  98           pool->tags[index] |= JV_CONSTANT_ResolvedFlag;
  99         }
 100       else
 101         {
 102           JvThrow (new java::lang::IllegalAccessError (found->getName()));
 103         }
 104     }
 105     break;
 106
 107   case JV_CONSTANT_String:
 108     {
 109       jstring str;
 110       str = _Jv_NewStringUtf8Const (pool->data[index].utf8);
 111       pool->data[index].o = str;
 112       pool->tags[index] |= JV_CONSTANT_ResolvedFlag;
 113     }
 114     break;
 115
 116
 117   case JV_CONSTANT_Fieldref:
 118     {
 119       _Jv_ushort class_index, name_and_type_index;
 120       _Jv_loadIndexes (&pool->data[index],
 121                        class_index,
 122                        name_and_type_index);
 123       jclass owner = (_Jv_ResolvePoolEntry (klass, class_index)).clazz;
 124
 125       if (owner != klass)
 126         _Jv_InitClass (owner);
 127
 128       _Jv_ushort name_index, type_index;
 129       _Jv_loadIndexes (&pool->data[name_and_type_index],
 130                        name_index,
 131                        type_index);
 132
 133       _Jv_Utf8Const *field_name = pool->data[name_index].utf8;
 134       _Jv_Utf8Const *field_type_name = pool->data[type_index].utf8;
 135
 136       // FIXME: The implementation of this function
 137       // (_Jv_FindClassFromSignature) will generate an instance of
 138       // _Jv_Utf8Const for each call if the field type is a class name
 139       // (Lxx.yy.Z;).  This may be too expensive to do for each and
 140       // every fieldref being resolved.  For now, we fix the problem by
 141       // only doing it when we have a loader different from the class
 142       // declaring the field.
 143
 144       jclass field_type = 0;
 145
 146       if (owner->loader != klass->loader)
 147         field_type = _Jv_FindClassFromSignature (field_type_name->data,
 148                                                  klass->loader);
 149
 150       _Jv_Field* the_field = 0;
 151
 152       for (jclass cls = owner; cls != 0; cls = cls->getSuperclass ())
 153         {
 154           for (int i = 0;  i < cls->field_count;  i++)
 155             {
 156               _Jv_Field *field = &cls->fields[i];
 157               if (! _Jv_equalUtf8Consts (field->name, field_name))
 158                 continue;
 159
 160               // now, check field access.
 161
 162               if (   (cls == klass)
 163                   || ((field->flags & Modifier::PUBLIC) != 0)
 164                   || (((field->flags & Modifier::PROTECTED) != 0)
 165                       && cls->isAssignableFrom (klass))
 166                   || (((field->flags & Modifier::PRIVATE) == 0)
 167                       && _Jv_ClassNameSamePackage (cls->name,
 168                                                    klass->name)))
 169                 {
 170                   /* resove the field using the class' own loader
 171                      if necessary */
 172
 173                   if (!field->isResolved ())
 174                     _Jv_ResolveField (field, cls->loader);
 175
 176                   if (field_type != 0 && field->type != field_type)
 177                     JvThrow
 178                       (new java::lang::LinkageError
 179                        (JvNewStringLatin1
 180                         ("field type mismatch with different loaders")));
 181
 182                   the_field = field;
 183                   goto end_of_field_search;
 184                 }
 185               else
 186                 {
 187                   JvThrow (new java::lang::IllegalAccessError);
 188                 }
 189             }
 190         }
 191
 192     end_of_field_search:
 193       if (the_field == 0)
 194         {
 195           jstring msg = JvNewStringLatin1 ("field ");
 196           msg = msg->concat (owner->getName ());
 197           msg = msg->concat (JvNewStringLatin1("."));
 198           msg = msg->concat (_Jv_NewStringUTF (field_name->data));
 199           msg = msg->concat (JvNewStringLatin1(" was not found."));
 200           throw_incompatible_class_change_error (msg);
 201         }
 202
 203       pool->data[index].field = the_field;
 204       pool->tags[index] |= JV_CONSTANT_ResolvedFlag;
 205     }
 206     break;
 207
 208   case JV_CONSTANT_Methodref:
 209   case JV_CONSTANT_InterfaceMethodref:
 210     {
 211       _Jv_ushort class_index, name_and_type_index;
 212       _Jv_loadIndexes (&pool->data[index],
 213                        class_index,
 214                        name_and_type_index);
 215       jclass owner = (_Jv_ResolvePoolEntry (klass, class_index)).clazz;
 216
 217       if (owner != klass)
 218         _Jv_InitClass (owner);
 219
 220       _Jv_ushort name_index, type_index;
 221       _Jv_loadIndexes (&pool->data[name_and_type_index],
 222                        name_index,
 223                        type_index);
 224
 225       _Jv_Utf8Const *method_name = pool->data[name_index].utf8;
 226       _Jv_Utf8Const *method_signature = pool->data[type_index].utf8;
 227
 228       int vtable_index = -1;
 229       _Jv_Method *the_method = 0;
 230       jclass found_class = 0;
 231
 232       // First search the class itself.
 233       the_method = _Jv_SearchMethodInClass (owner, klass,
 234                    method_name, method_signature);
 235
 236       if (the_method != 0)
 237         {
 238           found_class = owner;
 239           goto end_of_method_search;
 240         }
 241
 242       // If we are resolving an interface method, search the interface's
 243       // superinterfaces (A superinterface is not an interface's superclass -
 244       // a superinterface is implemented by the interface).
 245       if (pool->tags[index] == JV_CONSTANT_InterfaceMethodref)
 246         {
 247           _Jv_ifaces ifaces;
 248           ifaces.count = 0;
 249           ifaces.len = 4;
 250           ifaces.list = (jclass *) _Jv_Malloc (ifaces.len * sizeof (jclass *));
 251
 252           _Jv_GetInterfaces (owner, &ifaces);
 253
 254           for (int i=0; i < ifaces.count; i++)
 255             {
 256               jclass cls = ifaces.list[i];
 257               the_method = _Jv_SearchMethodInClass (cls, klass, method_name,
 258                                                     method_signature);
 259               if (the_method != 0)
 260                 {
 261                   found_class = cls;
 262                   break;
 263                 }
 264             }
 265
 266           _Jv_Free (ifaces.list);
 267
 268           if (the_method != 0)
 269             goto end_of_method_search;
 270         }
 271
 272       // Finally, search superclasses.
 273       for (jclass cls = owner->getSuperclass (); cls != 0;
 274            cls = cls->getSuperclass ())
 275         {
 276           the_method = _Jv_SearchMethodInClass (cls, klass,
 277                        method_name, method_signature);
 278           if (the_method != 0)
 279             {
 280               found_class = cls;
 281               break;
 282             }
 283         }
 284
 285     end_of_method_search:
 286
 287       // FIXME: if (cls->loader != klass->loader), then we
 288       // must actually check that the types of arguments
 289       // correspond.  That is, for each argument type, and
 290       // the return type, doing _Jv_FindClassFromSignature
 291       // with either loader should produce the same result,
 292       // i.e., exactly the same jclass object. JVMS 5.4.3.3
 293
 294       if (pool->tags[index] == JV_CONSTANT_InterfaceMethodref)
 295         vtable_index = -1;
 296       else
 297         vtable_index = _Jv_DetermineVTableIndex
 298           (found_class, method_name, method_signature);
 299
 300       if (vtable_index == METHOD_NOT_THERE)
 301         throw_incompatible_class_change_error
 302           (JvNewStringLatin1 ("method not found"));
 303
 304       if (the_method == 0)
 305         {
 306           jstring msg = JvNewStringLatin1 ("method ");
 307           msg = msg->concat (owner->getName ());
 308           msg = msg->concat (JvNewStringLatin1("."));
 309           msg = msg->concat (_Jv_NewStringUTF (method_name->data));
 310           msg = msg->concat (JvNewStringLatin1(" was not found."));
 311           JvThrow(new java::lang::NoSuchMethodError (msg));
 312         }
 313
 314       pool->data[index].rmethod =
 315         _Jv_BuildResolvedMethod(the_method,
 316                                 found_class,
 317                                 (the_method->accflags & Modifier::STATIC) != 0,
 318                                 vtable_index);
 319       pool->tags[index] |= JV_CONSTANT_ResolvedFlag;
 320     }
 321     break;
 322
 323   }
 324
 325   return pool->data[index];
 326 }
 327
 328 // Find a method declared in the cls that is referenced from klass and
 329 // perform access checks.
 330 _Jv_Method *
 331 _Jv_SearchMethodInClass (jclass cls, jclass klass,
 332                          _Jv_Utf8Const *method_name,
 333                          _Jv_Utf8Const *method_signature)
 334 {
 335   using namespace java::lang::reflect;
 336
 337   for (int i = 0;  i < cls->method_count;  i++)
 338     {
 339       _Jv_Method *method = &cls->methods[i];
 340       if (   (!_Jv_equalUtf8Consts (method->name,
 341                                     method_name))
 342           || (!_Jv_equalUtf8Consts (method->signature,
 343                                     method_signature)))
 344         continue;
 345
 346       if (cls == klass
 347           || ((method->accflags & Modifier::PUBLIC) != 0)
 348           || (((method->accflags & Modifier::PROTECTED) != 0)
 349               && cls->isAssignableFrom (klass))
 350           || (((method->accflags & Modifier::PRIVATE) == 0)
 351               && _Jv_ClassNameSamePackage (cls->name,
 352                                            klass->name)))
 353         {
 354           return method;
 355         }
 356       else
 357         {
 358           JvThrow (new java::lang::IllegalAccessError);
 359         }
 360     }
 361   return 0;
 362 }
 363
 364 void
 365 _Jv_ResolveField (_Jv_Field *field, java::lang::ClassLoader *loader)
 366 {
 367   if (! field->isResolved ())
 368     {
 369       _Jv_Utf8Const *sig = (_Jv_Utf8Const*)field->type;
 370       field->type = _Jv_FindClassFromSignature (sig->data, loader);
 371       field->flags &= ~_Jv_FIELD_UNRESOLVED_FLAG;
 372     }
 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*)
 702     _Jv_AllocBytesChecked (sizeof (_Jv_VTable)
 703                            + (sizeof (void*) * (vtable_count)));
 704   vtable->clas = clz;
 705   vtable->gc_descr = _Jv_BuildGCDescr(clz);
 706
 707   {
 708     jclass effective_superclass = super_class;
 709
 710     /* If super_class is abstract or an interface it has no vtable.
 711        We need to find a real one... */
 712     while (effective_superclass && effective_superclass->vtable == NULL)
 713       effective_superclass = effective_superclass->superclass;
 714
 715     /* copy super class' vtable entries. */
 716     if (effective_superclass && effective_superclass->vtable)
 717       memcpy ((void*)&vtable->method[0],
 718               (void*)&effective_superclass->vtable->method[0],
 719               sizeof (void*) * effective_superclass->vtable_method_count);
 720   }
 721
 722   /* now, install our own vtable entries, reprise... */
 723   for (int i = 0; i < clz->method_count; i++)
 724     {
 725       _Jv_Method *this_meth = &clz->methods[i];
 726
 727       int index = _Jv_DetermineVTableIndex (clz,
 728                                             this_meth->name,
 729                                             this_meth->signature);
 730
 731       if (index == METHOD_NOT_THERE)
 732         throw_internal_error ("method now found in own class");
 733
 734       if (index != METHOD_INACCESSIBLE)
 735         {
 736           if (index > clz->vtable_method_count)
 737             throw_internal_error ("vtable problem...");
 738
 739           if (clz->interpreted_methods[i] == 0)
 740             vtable->method[index] = (void*)&_Jv_abstractMethodError;
 741           else
 742             vtable->method[index] = this_meth->ncode;
 743         }
 744     }
 745
 746   /* finally, assign the vtable! */
 747   clz->vtable = vtable;
 748
 749   /* wooha! we're done. */
 750   clz->state = JV_STATE_PREPARED;
 751   clz->notifyAll ();
 752 }
 753
 754 /** Do static initialization for fields with a constant initializer */
 755 void
 756 _Jv_InitField (jobject obj, jclass klass, int index)
 757 {
 758   using namespace java::lang::reflect;
 759
 760   if (obj != 0 && klass == 0)
 761     klass = obj->getClass ();
 762
 763   if (!_Jv_IsInterpretedClass (klass))
 764     return;
 765
 766   _Jv_InterpClass *clz = (_Jv_InterpClass*)klass;
 767
 768   _Jv_Field * field = (&clz->fields[0]) + index;
 769
 770   if (index > clz->field_count)
 771     throw_internal_error ("field out of range");
 772
 773   int init = clz->field_initializers[index];
 774   if (init == 0)
 775     return;
 776
 777   _Jv_Constants *pool = &clz->constants;
 778   int tag = pool->tags[init];
 779
 780   if (! field->isResolved ())
 781     throw_internal_error ("initializing unresolved field");
 782
 783   if (obj==0 && ((field->flags & Modifier::STATIC) == 0))
 784     throw_internal_error ("initializing non-static field with no object");
 785
 786   void *addr = 0;
 787
 788   if ((field->flags & Modifier::STATIC) != 0)
 789     addr = (void*) field->u.addr;
 790   else
 791     addr = (void*) (((char*)obj) + field->u.boffset);
 792
 793   switch (tag)
 794     {
 795     case JV_CONSTANT_String:
 796       {
 797         _Jv_MonitorEnter (clz);
 798         jstring str;
 799         str = _Jv_NewStringUtf8Const (pool->data[init].utf8);
 800         pool->data[init].string = str;
 801         pool->tags[init] = JV_CONSTANT_ResolvedString;
 802         _Jv_MonitorExit (clz);
 803       }
 804       /* fall through */
 805
 806     case JV_CONSTANT_ResolvedString:
 807       if (! (field->type == &StringClass
 808              || field->type == &java::lang::Class::class$))
 809         throw_class_format_error ("string initialiser to non-string field");
 810
 811       *(jstring*)addr = pool->data[init].string;
 812       break;
 813
 814     case JV_CONSTANT_Integer:
 815       {
 816         int value = pool->data[init].i;
 817
 818         if (field->type == JvPrimClass (boolean))
 819           *(jboolean*)addr = (jboolean)value;
 820
 821         else if (field->type == JvPrimClass (byte))
 822           *(jbyte*)addr = (jbyte)value;
 823
 824         else if (field->type == JvPrimClass (char))
 825           *(jchar*)addr = (jchar)value;
 826
 827         else if (field->type == JvPrimClass (short))
 828           *(jshort*)addr = (jshort)value;
 829
 830         else if (field->type == JvPrimClass (int))
 831           *(jint*)addr = (jint)value;
 832
 833         else
 834           throw_class_format_error ("erroneous field initializer");
 835       }
 836       break;
 837
 838     case JV_CONSTANT_Long:
 839       if (field->type != JvPrimClass (long))
 840         throw_class_format_error ("erroneous field initializer");
 841
 842       *(jlong*)addr = _Jv_loadLong (&pool->data[init]);
 843       break;
 844
 845     case JV_CONSTANT_Float:
 846       if (field->type != JvPrimClass (float))
 847         throw_class_format_error ("erroneous field initializer");
 848
 849       *(jfloat*)addr = pool->data[init].f;
 850       break;
 851
 852     case JV_CONSTANT_Double:
 853       if (field->type != JvPrimClass (double))
 854         throw_class_format_error ("erroneous field initializer");
 855
 856       *(jdouble*)addr = _Jv_loadDouble (&pool->data[init]);
 857       break;
 858
 859     default:
 860       throw_class_format_error ("erroneous field initializer");
 861     }
 862 }
 863
 864 static int
 865 get_alignment_from_class (jclass klass)
 866 {
 867   if (klass == JvPrimClass (byte))
 868     return  __alignof__ (jbyte);
 869   else if (klass == JvPrimClass (short))
 870     return  __alignof__ (jshort);
 871   else if (klass == JvPrimClass (int))
 872     return  __alignof__ (jint);
 873   else if (klass == JvPrimClass (long))
 874     return  __alignof__ (jlong);
 875   else if (klass == JvPrimClass (boolean))
 876     return  __alignof__ (jboolean);
 877   else if (klass == JvPrimClass (char))
 878     return  __alignof__ (jchar);
 879   else if (klass == JvPrimClass (float))
 880     return  __alignof__ (jfloat);
 881   else if (klass == JvPrimClass (double))
 882     return  __alignof__ (jdouble);
 883   else
 884     return __alignof__ (jobject);
 885 }
 886
 887
 888 inline static unsigned char*
 889 skip_one_type (unsigned char* ptr)
 890 {
 891   int ch = *ptr++;
 892
 893   while (ch == '[')
 894     {
 895       ch = *ptr++;
 896     }
 897
 898   if (ch == 'L')
 899     {
 900       do { ch = *ptr++; } while (ch != ';');
 901     }
 902
 903   return ptr;
 904 }
 905
 906 static ffi_type*
 907 get_ffi_type_from_signature (unsigned char* ptr)
 908 {
 909   switch (*ptr)
 910     {
 911     case 'L':
 912     case '[':
 913       return &ffi_type_pointer;
 914       break;
 915
 916     case 'Z':
 917       // On some platforms a bool is a byte, on others an int.
 918       if (sizeof (jboolean) == sizeof (jbyte))
 919         return &ffi_type_sint8;
 920       else
 921         {
 922           JvAssert (sizeof (jbyte) == sizeof (jint));
 923           return &ffi_type_sint32;
 924         }
 925       break;
 926
 927     case 'B':
 928       return &ffi_type_sint8;
 929       break;
 930
 931     case 'C':
 932       return &ffi_type_uint16;
 933       break;
 934
 935     case 'S':
 936       return &ffi_type_sint16;
 937       break;
 938
 939     case 'I':
 940       return &ffi_type_sint32;
 941       break;
 942
 943     case 'J':
 944       return &ffi_type_sint64;
 945       break;
 946
 947     case 'F':
 948       return &ffi_type_float;
 949       break;
 950
 951     case 'D':
 952       return &ffi_type_double;
 953       break;
 954
 955     case 'V':
 956       return &ffi_type_void;
 957       break;
 958     }
 959
 960   throw_internal_error ("unknown type in signature");
 961 }
 962
 963 /* this function yields the number of actual arguments, that is, if the
 964  * function is non-static, then one is added to the number of elements
 965  * found in the signature */
 966
 967 static int
 968 count_arguments (_Jv_Utf8Const *signature,
 969                  jboolean staticp)
 970 {
 971   unsigned char *ptr = (unsigned char*) signature->data;
 972   int arg_count = staticp ? 0 : 1;
 973
 974   /* first, count number of arguments */
 975
 976   // skip '('
 977   ptr++;
 978
 979   // count args
 980   while (*ptr != ')')
 981     {
 982       ptr = skip_one_type (ptr);
 983       arg_count += 1;
 984     }
 985
 986   return arg_count;
 987 }
 988
 989 /* This beast will build a cif, given the signature.  Memory for
 990  * the cif itself and for the argument types must be allocated by the
 991  * caller.
 992  */
 993
 994 static int
 995 init_cif (_Jv_Utf8Const* signature,
 996           int arg_count,
 997           jboolean staticp,
 998           ffi_cif *cif,
 999           ffi_type **arg_types,
1000           ffi_type **rtype_p)
1001 {
1002   unsigned char *ptr = (unsigned char*) signature->data;
1003
1004   int arg_index = 0;            // arg number
1005   int item_count = 0;           // stack-item count
1006
1007   // setup receiver
1008   if (!staticp)
1009     {
1010       arg_types[arg_index++] = &ffi_type_pointer;
1011       item_count += 1;
1012     }
1013
1014   // skip '('
1015   ptr++;
1016
1017   // assign arg types
1018   while (*ptr != ')')
1019     {
1020       arg_types[arg_index++] = get_ffi_type_from_signature (ptr);
1021
1022       if (*ptr == 'J' || *ptr == 'D')
1023         item_count += 2;
1024       else
1025         item_count += 1;
1026
1027       ptr = skip_one_type (ptr);
1028     }
1029
1030   // skip ')'
1031   ptr++;
1032   ffi_type *rtype = get_ffi_type_from_signature (ptr);
1033
1034   ptr = skip_one_type (ptr);
1035   if (ptr != (unsigned char*)signature->data + signature->length)
1036     throw_internal_error ("did not find end of signature");
1037
1038   if (ffi_prep_cif (cif, FFI_DEFAULT_ABI,
1039                     arg_count, rtype, arg_types) != FFI_OK)
1040     throw_internal_error ("ffi_prep_cif failed");
1041
1042   if (rtype_p != NULL)
1043     *rtype_p = rtype;
1044
1045   return item_count;
1046 }
1047
1048 #if FFI_NATIVE_RAW_API
1049 #   define FFI_PREP_RAW_CLOSURE ffi_prep_raw_closure
1050 #   define FFI_RAW_SIZE ffi_raw_size
1051 #else
1052 #   define FFI_PREP_RAW_CLOSURE ffi_prep_java_raw_closure
1053 #   define FFI_RAW_SIZE ffi_java_raw_size
1054 #endif
1055
1056 /* we put this one here, and not in interpret.cc because it
1057  * calls the utility routines count_arguments
1058  * which are static to this module.  The following struct defines the
1059  * layout we use for the stubs, it's only used in the ncode method. */
1060
1061 typedef struct {
1062   ffi_raw_closure  closure;
1063   ffi_cif   cif;
1064   ffi_type *arg_types[0];
1065 } ncode_closure;
1066
1067 typedef void (*ffi_closure_fun) (ffi_cif*,void*,ffi_raw*,void*);
1068
1069 void *
1070 _Jv_InterpMethod::ncode ()
1071 {
1072   using namespace java::lang::reflect;
1073
1074   if (self->ncode != 0)
1075     return self->ncode;
1076
1077   jboolean staticp = (self->accflags & Modifier::STATIC) != 0;
1078   int arg_count = count_arguments (self->signature, staticp);
1079
1080   ncode_closure *closure =
1081     (ncode_closure*)_Jv_AllocBytesChecked (sizeof (ncode_closure)
1082                                         + arg_count * sizeof (ffi_type*));
1083
1084   init_cif (self->signature,
1085             arg_count,
1086             staticp,
1087             &closure->cif,
1088             &closure->arg_types[0],
1089             NULL);
1090
1091   ffi_closure_fun fun;
1092
1093   args_raw_size = FFI_RAW_SIZE (&closure->cif);
1094
1095   JvAssert ((self->accflags & Modifier::NATIVE) == 0);
1096
1097   if ((self->accflags & Modifier::SYNCHRONIZED) != 0)
1098     {
1099       if (staticp)
1100         fun = (ffi_closure_fun)&_Jv_InterpMethod::run_synch_class;
1101       else
1102         fun = (ffi_closure_fun)&_Jv_InterpMethod::run_synch_object;
1103     }
1104   else
1105     {
1106       fun = (ffi_closure_fun)&_Jv_InterpMethod::run_normal;
1107     }
1108
1109   FFI_PREP_RAW_CLOSURE (&closure->closure,
1110                         &closure->cif,
1111                         fun,
1112                         (void*)this);
1113
1114   self->ncode = (void*)closure;
1115   return self->ncode;
1116 }
1117
1118
1119 void *
1120 _Jv_JNIMethod::ncode ()
1121 {
1122   using namespace java::lang::reflect;
1123
1124   if (self->ncode != 0)
1125     return self->ncode;
1126
1127   jboolean staticp = (self->accflags & Modifier::STATIC) != 0;
1128   int arg_count = count_arguments (self->signature, staticp);
1129
1130   ncode_closure *closure =
1131     (ncode_closure*)_Jv_AllocBytesChecked (sizeof (ncode_closure)
1132                                         + arg_count * sizeof (ffi_type*));
1133
1134   ffi_type *rtype;
1135   init_cif (self->signature,
1136             arg_count,
1137             staticp,
1138             &closure->cif,
1139             &closure->arg_types[0],
1140             &rtype);
1141
1142   ffi_closure_fun fun;
1143
1144   args_raw_size = FFI_RAW_SIZE (&closure->cif);
1145
1146   // Initialize the argument types and CIF that represent the actual
1147   // underlying JNI function.
1148   int extra_args = 1;
1149   if ((self->accflags & Modifier::STATIC))
1150     ++extra_args;
1151   jni_arg_types = (ffi_type **) _Jv_Malloc ((extra_args + arg_count)
1152                                             * sizeof (ffi_type *));
1153   int offset = 0;
1154   jni_arg_types[offset++] = &ffi_type_pointer;
1155   if ((self->accflags & Modifier::STATIC))
1156     jni_arg_types[offset++] = &ffi_type_pointer;
1157   memcpy (&jni_arg_types[offset], &closure->arg_types[0],
1158           arg_count * sizeof (ffi_type *));
1159
1160   if (ffi_prep_cif (&jni_cif, FFI_DEFAULT_ABI,
1161                     extra_args + arg_count, rtype,
1162                     jni_arg_types) != FFI_OK)
1163     throw_internal_error ("ffi_prep_cif failed for JNI function");
1164
1165   JvAssert ((self->accflags & Modifier::NATIVE) != 0);
1166
1167   // FIXME: for now we assume that all native methods for
1168   // interpreted code use JNI.
1169   fun = (ffi_closure_fun) &_Jv_JNIMethod::call;
1170
1171   FFI_PREP_RAW_CLOSURE (&closure->closure,
1172                         &closure->cif,
1173                         fun,
1174                         (void*) this);
1175
1176   self->ncode = (void *) closure;
1177   return self->ncode;
1178 }
1179
1180
1181 /* A _Jv_ResolvedMethod is what is put in the constant pool for a
1182  * MethodRef or InterfacemethodRef.  */
1183 static _Jv_ResolvedMethod*
1184 _Jv_BuildResolvedMethod (_Jv_Method* method,
1185                          jclass      klass,
1186                          jboolean staticp,
1187                          jint vtable_index)
1188 {
1189   int arg_count = count_arguments (method->signature, staticp);
1190
1191   _Jv_ResolvedMethod* result = (_Jv_ResolvedMethod*)
1192     _Jv_AllocBytesChecked (sizeof (_Jv_ResolvedMethod)
1193                            + arg_count*sizeof (ffi_type*));
1194
1195   result->stack_item_count
1196     = init_cif (method->signature,
1197                 arg_count,
1198                 staticp,
1199                 &result->cif,
1200                 &result->arg_types[0],
1201                 NULL);
1202
1203   result->vtable_index        = vtable_index;
1204   result->method              = method;
1205   result->klass               = klass;
1206
1207   return result;
1208 }
1209
1210
1211 static void
1212 throw_class_format_error (jstring msg)
1213 {
1214   if (msg == 0)
1215     JvThrow (new java::lang::ClassFormatError);
1216   else
1217     JvThrow (new java::lang::ClassFormatError (msg));
1218 }
1219
1220 static void
1221 throw_class_format_error (char *msg)
1222 {
1223   throw_class_format_error (JvNewStringLatin1 (msg));
1224 }
1225
1226 static void
1227 throw_internal_error (char *msg)
1228 {
1229   JvThrow
1230     (new java::lang::InternalError (JvNewStringLatin1 (msg)));
1231 }
1232
1233
1234 #endif /* INTERPRETER */