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