libjava/resolve.cc

   1 // resolve.cc - Code for linking and resolving classes and pool entries.
   2
   3 /* Copyright (C) 1999  Cygnus Solutions
   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/ClassFormatError.h>
  28 #include <java/lang/IllegalAccessError.h>
  29 #include <java/lang/AbstractMethodError.h>
  30 #include <java/lang/ClassNotFoundException.h>
  31 #include <java/lang/IncompatibleClassChangeError.h>
  32 #include <java/lang/reflect/Modifier.h>
  33
  34 #ifdef INTERPRETER
  35
  36 static void throw_internal_error (char *msg)
  37         __attribute__ ((__noreturn__));
  38 static void throw_class_format_error (jstring msg)
  39         __attribute__ ((__noreturn__));
  40 static void throw_class_format_error (char *msg)
  41         __attribute__ ((__noreturn__));
  42
  43 #define StringClass _CL_Q34java4lang6String
  44 extern java::lang::Class StringClass;
  45 #define ClassObject _CL_Q34java4lang6Object
  46 extern java::lang::Class ClassObject;
  47 #define ObjectClass _CL_Q34java4lang6Object
  48 extern java::lang::Class ObjectClass;
  49
  50
  51 static int get_alignment_from_class (jclass);
  52
  53 static _Jv_ResolvedMethod*
  54 _Jv_BuildResolvedMethod (_Jv_Method*,
  55                          jclass,
  56                          jboolean,
  57                          jint);
  58
  59
  60 // We need to know the name of a constructor.
  61 static _Jv_Utf8Const *init_name = _Jv_makeUtf8Const ("<init>", 6);
  62
  63 static void throw_incompatible_class_change_error (jstring msg)
  64 {
  65   JvThrow (new java::lang::IncompatibleClassChangeError (msg));
  66 }
  67
  68 _Jv_word
  69 _Jv_ResolvePoolEntry (jclass klass, int index)
  70 {
  71   using namespace java::lang::reflect;
  72
  73   _Jv_Constants *pool = &klass->constants;
  74
  75   if ((pool->tags[index] & JV_CONSTANT_ResolvedFlag) != 0)
  76     return pool->data[index];
  77
  78   switch (pool->tags[index]) {
  79   case JV_CONSTANT_Class:
  80     {
  81       _Jv_Utf8Const *name = pool->data[index].utf8;
  82
  83       jclass found;
  84       if (name->data[0] == '[')
  85         found = _Jv_FindClassFromSignature (&name->data[0],
  86                                             klass->loader);
  87       else
  88         found = _Jv_FindClass (name, klass->loader);
  89
  90       if (! found)
  91         {
  92           jstring str = _Jv_NewStringUTF (name->data);
  93           JvThrow (new java::lang::ClassNotFoundException (str));
  94         }
  95
  96       if ((found->accflags & Modifier::PUBLIC) == Modifier::PUBLIC
  97           || (_Jv_ClassNameSamePackage (found->name,
  98                                         klass->name)))
  99         {
 100           pool->data[index].clazz = found;
 101           pool->tags[index] |= JV_CONSTANT_ResolvedFlag;
 102         }
 103       else
 104         {
 105           JvThrow (new java::lang::IllegalAccessError (found->getName()));
 106         }
 107     }
 108     break;
 109
 110   case JV_CONSTANT_String:
 111     {
 112       jstring str;
 113       str = _Jv_NewStringUtf8Const (pool->data[index].utf8);
 114       pool->data[index].o = str;
 115       pool->tags[index] |= JV_CONSTANT_ResolvedFlag;
 116     }
 117     break;
 118
 119
 120   case JV_CONSTANT_Fieldref:
 121     {
 122       _Jv_ushort class_index, name_and_type_index;
 123       _Jv_loadIndexes (&pool->data[index],
 124                        class_index,
 125                        name_and_type_index);
 126       jclass owner = (_Jv_ResolvePoolEntry (klass, class_index)).clazz;
 127
 128       if (owner != klass)
 129         _Jv_InitClass (owner);
 130
 131       _Jv_ushort name_index, type_index;
 132       _Jv_loadIndexes (&pool->data[name_and_type_index],
 133                        name_index,
 134                        type_index);
 135
 136       _Jv_Utf8Const *field_name = pool->data[name_index].utf8;
 137       _Jv_Utf8Const *field_type_name = pool->data[type_index].utf8;
 138
 139       // FIXME: The implementation of this function
 140       // (_Jv_FindClassFromSignature) will generate an instance of
 141       // _Jv_Utf8Const for each call if the field type is a class name
 142       // (Lxx.yy.Z;).  This may be too expensive to do for each and
 143       // every fieldref being resolved.  For now, we fix the problem by
 144       // only doing it when we have a loader different from the class
 145       // declaring the field.
 146
 147       jclass field_type = 0;
 148
 149       if (owner->loader != klass->loader)
 150         field_type = _Jv_FindClassFromSignature (field_type_name->data,
 151                                                  klass->loader);
 152
 153       _Jv_Field* the_field = 0;
 154
 155       for (jclass cls = owner; cls != 0; cls = cls->getSuperclass ())
 156         {
 157           for (int i = 0;  i < cls->field_count;  i++)
 158             {
 159               _Jv_Field *field = &cls->fields[i];
 160               if (! _Jv_equalUtf8Consts (field->name, field_name))
 161                 continue;
 162
 163               // now, check field access.
 164
 165               if (   (cls == klass)
 166                   || ((field->flags & Modifier::PUBLIC) != 0)
 167                   || (((field->flags & Modifier::PROTECTED) != 0)
 168                       && cls->isAssignableFrom (klass))
 169                   || (((field->flags & Modifier::PRIVATE) == 0)
 170                       && _Jv_ClassNameSamePackage (cls->name,
 171                                                    klass->name)))
 172                 {
 173                   /* resove the field using the class' own loader
 174                      if necessary */
 175
 176                   if (!field->isResolved ())
 177                     _Jv_ResolveField (field, cls->loader);
 178
 179                   if (field_type != 0 && field->type != field_type)
 180                     JvThrow
 181                       (new java::lang::LinkageError
 182                        (JvNewStringLatin1
 183                         ("field type mismatch with different loaders")));
 184
 185                   the_field = field;
 186                   goto end_of_field_search;
 187                 }
 188               else
 189                 {
 190                   JvThrow (new java::lang::IllegalAccessError);
 191                 }
 192             }
 193         }
 194
 195     end_of_field_search:
 196       if (the_field == 0)
 197         {
 198           jstring msg = JvNewStringLatin1 ("field ");
 199           msg = msg->concat (owner->getName ());
 200           msg = msg->concat (JvNewStringLatin1("."));
 201           msg = msg->concat (_Jv_NewStringUTF (field_name->data));
 202           msg = msg->concat (JvNewStringLatin1(" was not found."));
 203           throw_incompatible_class_change_error (msg);
 204         }
 205
 206       pool->data[index].field = the_field;
 207       pool->tags[index] |= JV_CONSTANT_ResolvedFlag;
 208     }
 209     break;
 210
 211   case JV_CONSTANT_Methodref:
 212   case JV_CONSTANT_InterfaceMethodref:
 213     {
 214       _Jv_ushort class_index, name_and_type_index;
 215       _Jv_loadIndexes (&pool->data[index],
 216                        class_index,
 217                        name_and_type_index);
 218       jclass owner = (_Jv_ResolvePoolEntry (klass, class_index)).clazz;
 219
 220       if (owner != klass)
 221         _Jv_InitClass (owner);
 222
 223       _Jv_ushort name_index, type_index;
 224       _Jv_loadIndexes (&pool->data[name_and_type_index],
 225                        name_index,
 226                        type_index);
 227
 228       _Jv_Utf8Const *method_name = pool->data[name_index].utf8;
 229       _Jv_Utf8Const *method_signature = pool->data[type_index].utf8;
 230
 231       int vtable_index = -1;
 232       _Jv_Method *the_method = 0;
 233       jclass found_class = 0;
 234
 235       // we make a loop here, because methods are allowed to be moved to
 236       // a super class, and still be visible.. (binary compatibility).
 237
 238       for (jclass cls = owner; cls != 0; cls = cls->getSuperclass ())
 239         {
 240           for (int i = 0;  i < cls->method_count;  i++)
 241             {
 242               _Jv_Method *method = &cls->methods[i];
 243               if (   (!_Jv_equalUtf8Consts (method->name,
 244                                             method_name))
 245                   || (!_Jv_equalUtf8Consts (method->signature,
 246                                             method_signature)))
 247                 continue;
 248
 249               if (cls == klass
 250                   || ((method->accflags & Modifier::PUBLIC) != 0)
 251                   || (((method->accflags & Modifier::PROTECTED) != 0)
 252                       && cls->isAssignableFrom (klass))
 253                   || (((method->accflags & Modifier::PRIVATE) == 0)
 254                       && _Jv_ClassNameSamePackage (cls->name,
 255                                                    klass->name)))
 256                 {
 257                   // FIXME: if (cls->loader != klass->loader), then we
 258                   // must actually check that the types of arguments
 259                   // correspond.  That is, for each argument type, and
 260                   // the return type, doing _Jv_FindClassFromSignature
 261                   // with either loader should produce the same result,
 262                   // i.e., exactly the same jclass object. JVMS 5.4.3.3
 263
 264                   the_method = method;
 265                   found_class = cls;
 266
 267
 268                   if (pool->tags[index] == JV_CONSTANT_InterfaceMethodref)
 269                     vtable_index = -1;
 270                   else
 271                     vtable_index = _Jv_DetermineVTableIndex
 272                       (cls, method_name, method_signature);
 273
 274                   if (vtable_index == 0)
 275                     throw_incompatible_class_change_error
 276                       (JvNewStringLatin1 ("method not found"));
 277
 278                   goto end_of_method_search;
 279                 }
 280               else
 281                 {
 282                   JvThrow (new java::lang::IllegalAccessError);
 283                 }
 284             }
 285         }
 286
 287     end_of_method_search:
 288       if (the_method == 0)
 289         {
 290           jstring msg = JvNewStringLatin1 ("method ");
 291           msg = msg->concat (owner->getName ());
 292           msg = msg->concat (JvNewStringLatin1("."));
 293           msg = msg->concat (_Jv_NewStringUTF (method_name->data));
 294           msg = msg->concat (JvNewStringLatin1(" was not found."));
 295           JvThrow(new java::lang::NoSuchFieldError (msg));
 296         }
 297
 298       pool->data[index].rmethod =
 299         _Jv_BuildResolvedMethod(the_method,
 300                                 found_class,
 301                                 (the_method->accflags & Modifier::STATIC) != 0,
 302                                 vtable_index);
 303       pool->tags[index] |= JV_CONSTANT_ResolvedFlag;
 304     }
 305     break;
 306
 307   }
 308
 309   return pool->data[index];
 310 }
 311
 312
 313 void
 314 _Jv_ResolveField (_Jv_Field *field, java::lang::ClassLoader *loader)
 315 {
 316   if (! field->isResolved ())
 317     {
 318       _Jv_Utf8Const *sig = (_Jv_Utf8Const*)field->type;
 319       field->type = _Jv_FindClassFromSignature (sig->data, loader);
 320       field->flags &= ~_Jv_FIELD_UNRESOLVED_FLAG;
 321     }
 322 }
 323
 324 _Jv_Method*
 325 _Jv_LookupDeclaredMethod (jclass klass, _Jv_Utf8Const *name,
 326                         _Jv_Utf8Const *signature)
 327 {
 328   for (; klass; klass = klass->getSuperclass())
 329     {
 330       _Jv_Method *meth = _Jv_GetMethodLocal (klass, name, signature);
 331
 332       if (meth)
 333         return meth;
 334     }
 335
 336   return NULL;
 337 }
 338
 339 /** FIXME: this is a terribly inefficient algorithm!  It would improve
 340     things if compiled classes to know vtable offset, and _Jv_Method had
 341     a field for this.
 342
 343     Returns 0  if this class does not declare the given method.
 344     Returns -1 if the given method does not appear in the vtable.
 345                i.e., it is static, private, final or a constructor.
 346     Otherwise, returns the vtable index.  */
 347 int
 348 _Jv_DetermineVTableIndex (jclass klass,
 349                           _Jv_Utf8Const *name,
 350                           _Jv_Utf8Const *signature)
 351 {
 352   using namespace java::lang::reflect;
 353
 354   jclass super_class = klass->getSuperclass ();
 355
 356   if (super_class != NULL)
 357     {
 358       int prev = _Jv_DetermineVTableIndex (super_class,
 359                                            name,
 360                                            signature);
 361       if (prev != 0)
 362         return prev;
 363     }
 364
 365   /* at this point, we know that the super-class does not declare
 366    * the method.  Otherwise, the above call would have found it, and
 367    * determined the result of this function (-1 or some positive
 368    * number).
 369    */
 370
 371   _Jv_Method *meth = _Jv_GetMethodLocal (klass, name, signature);
 372
 373   /* now, if we do not declare this method, return zero */
 374   if (meth == NULL)
 375     return 0;
 376
 377   /* so now, we know not only that the super class does not declare the
 378    * method, but we do!  So, this is a first declaration of the method. */
 379
 380   /* now, the checks for things that are declared in this class, but do
 381    * not go into the vtable.  There are three cases.
 382    * 1) the method is static, private or final
 383    * 2) the class itself is final, or
 384    * 3) it is the method <init>
 385    */
 386
 387   if ((meth->accflags & (Modifier::STATIC
 388                          | Modifier::PRIVATE
 389                          | Modifier::FINAL)) != 0
 390       || (klass->accflags & Modifier::FINAL) != 0
 391       || _Jv_equalUtf8Consts (name, init_name))
 392     return -1;
 393
 394   /* reaching this point, we know for sure, that the method in question
 395    * will be in the vtable.  The question is where. */
 396
 397   /* the base offset, is where we will start assigning vtable
 398    * indexes for this class.  It is 1 for base classes
 399    * (vtable->method[0] is unused), and for non-base classes it is the
 400    * number of entries in the super class' vtable plus 1. */
 401
 402   int base_offset;
 403   if (super_class == 0)
 404     base_offset = 1;
 405   else
 406     base_offset = super_class->vtable_method_count+1;
 407
 408   /* we will consider methods 0..this_method_index-1.  And for each one,
 409    * determine if it is new (i.e., if it appears in the super class),
 410    * and if it should go in the vtable.  If so, increment base_offset */
 411
 412   int this_method_index = meth - (&klass->methods[0]);
 413
 414   for (int i = 0; i < this_method_index; i++)
 415     {
 416       _Jv_Method *m = &klass->methods[i];
 417
 418       /* fist some checks for things that surely do not go in the
 419        * vtable */
 420
 421       if ((m->accflags & (Modifier::STATIC | Modifier::PRIVATE)) != 0)
 422         continue;
 423       if (_Jv_equalUtf8Consts (m->name, init_name))
 424         continue;
 425
 426       /* Then, we need to know if this method appears in the
 427          superclass. (This is where this function gets expensive) */
 428       _Jv_Method *sm = _Jv_LookupDeclaredMethod (super_class,
 429                                                  m->name,
 430                                                  m->signature);
 431
 432       /* if it was somehow declared in the superclass, skip this */
 433       if (sm != NULL)
 434         continue;
 435
 436       /* but if it is final, and not declared in the super class,
 437        * then we also skip it */
 438       if ((m->accflags & Modifier::FINAL) != 0)
 439         continue;
 440
 441       /* finally, we can assign the index of this method */
 442       /* m->vtable_index = base_offset */
 443       base_offset += 1;
 444     }
 445
 446   return base_offset;
 447 }
 448
 449 /* this is installed in place of abstract methods */
 450 static void
 451 _Jv_abstractMethodError ()
 452 {
 453   JvThrow (new java::lang::AbstractMethodError);
 454 }
 455
 456 void
 457 _Jv_PrepareClass(jclass klass)
 458 {
 459   using namespace java::lang::reflect;
 460
 461  /*
 462   * The job of this function is to: 1) assign storage to fields, and 2)
 463   * build the vtable.  static fields are assigned real memory, instance
 464   * fields are assigned offsets.
 465   *
 466   * NOTE: we have a contract with the garbage collector here.  Static
 467   * reference fields must not be resolved, until after they have storage
 468   * assigned which is the check used by the collector to see if it
 469   * should indirect the static field reference and mark the object
 470   * pointed to.
 471   *
 472   * Most fields are resolved lazily (i.e. have their class-type
 473   * assigned) when they are accessed the first time by calling as part
 474   * of _Jv_ResolveField, which is allways called after _Jv_PrepareClass.
 475   * Static fields with initializers are resolved as part of this
 476   * function, as are fields with primitive types.
 477   */
 478
 479   if (! _Jv_IsInterpretedClass (klass))
 480     return;
 481
 482   if (klass->state >= JV_STATE_PREPARED)
 483     return;
 484
 485   // make sure super-class is linked.  This involves taking a lock on
 486   // the super class, so we use the Java method resolveClass, which will
 487   // unlock it properly, should an exception happen.
 488
 489   java::lang::ClassLoader::resolveClass0 (klass->superclass);
 490
 491   _Jv_InterpClass *clz = (_Jv_InterpClass*)klass;
 492
 493   /************ PART ONE: OBJECT LAYOUT ***************/
 494
 495   int instance_size;
 496   int static_size;
 497
 498   // java.lang.Object is never interpreted!
 499   instance_size = clz->superclass->size ();
 500   static_size   = 0;
 501
 502   for (int i = 0; i < clz->field_count; i++)
 503     {
 504       int field_size;
 505       int field_align;
 506
 507       _Jv_Field *field = &clz->fields[i];
 508
 509       if (! field->isRef ())
 510         {
 511           // it's safe to resolve the field here, since it's
 512           // a primitive class, which does not cause loading to happen.
 513           _Jv_ResolveField (field, clz->loader);
 514
 515           field_size = field->type->size ();
 516           field_align = get_alignment_from_class (field->type);
 517         }
 518       else
 519         {
 520           field_size = sizeof (jobject);
 521           field_align = __alignof__ (jobject);
 522         }
 523
 524 #ifndef COMPACT_FIELDS
 525       field->bsize = field_size;
 526 #endif
 527
 528       if (field->flags & Modifier::STATIC)
 529         {
 530           /* this computes an offset into a region we'll allocate
 531              shortly, and then add this offset to the start address */
 532
 533           static_size        = ROUND (static_size, field_align);
 534           field->u.boffset   = static_size;
 535           static_size       += field_size;
 536         }
 537       else
 538         {
 539           instance_size      = ROUND (instance_size, field_align);
 540           field->u.boffset   = instance_size;
 541           instance_size     += field_size;
 542         }
 543     }
 544
 545   // set the instance size for the class
 546   clz->size_in_bytes = instance_size;
 547
 548   // allocate static memory
 549   if (static_size != 0)
 550     {
 551       char *static_data = (char*)_Jv_AllocBytesChecked (static_size);
 552
 553       memset (static_data, 0, static_size);
 554
 555       for (int i = 0; i < clz->field_count; i++)
 556         {
 557           _Jv_Field *field = &clz->fields[i];
 558
 559           if ((field->flags & Modifier::STATIC) != 0)
 560             {
 561               field->u.addr  = static_data + field->u.boffset;
 562
 563               if (clz->field_initializers[i] != 0)
 564                 {
 565                   _Jv_ResolveField (field, clz->loader);
 566                   _Jv_InitField (0, clz, i);
 567                 }
 568             }
 569         }
 570
 571       // now we don't need the field_initializers anymore, so let the
 572       // collector get rid of it!
 573
 574       clz->field_initializers = 0;
 575     }
 576
 577   /************ PART TWO: VTABLE LAYOUT ***************/
 578
 579   /* preparation: build the vtable stubs (even interfaces can)
 580      have code -- for static constructors. */
 581   for (int i = 0; i < clz->method_count; i++)
 582     {
 583       _Jv_InterpMethod *imeth = clz->interpreted_methods[i];
 584
 585       if (imeth != 0)           // it could be abstract or native
 586         {
 587           clz->methods[i].ncode = imeth->ncode ();
 588         }
 589       else
 590         {
 591           if ((clz->methods[i].accflags & Modifier::NATIVE) != 0)
 592             {
 593               JvThrow
 594                 (new java::lang::VirtualMachineError
 595                  (JvNewStringLatin1
 596                   ("the interpreter does not support native methods")));
 597             }
 598         }
 599     }
 600
 601   if (clz->accflags & Modifier::INTERFACE)
 602     {
 603       clz->state = JV_STATE_PREPARED;
 604       clz->notifyAll ();
 605       return;
 606     }
 607
 608   /* FIXME: native methods for interpreted classes should be handled, I
 609    * dunno exactly how, but it seems that we should try to find them at
 610    * this point, and if we fail, try again after <clinit>, since it
 611    * could have caused additional code to be loaded.  Interfaces cannot
 612    * have native methods (not even for static initialization). */
 613
 614
 615   /* Now onto the actual job: vtable layout.  First, count how many new
 616      methods we have */
 617   int new_method_count = 0;
 618
 619   jclass super_class = clz->getSuperclass ();
 620
 621   if (super_class == 0)
 622     throw_internal_error ("cannot handle interpreted base classes");
 623
 624   for (int i = 0; i < clz->method_count; i++)
 625     {
 626       _Jv_Method *this_meth = &clz->methods[i];
 627
 628       if ((this_meth->accflags & (Modifier::STATIC | Modifier::PRIVATE)) != 0
 629           || _Jv_equalUtf8Consts (this_meth->name, init_name))
 630         {
 631           /* skip this, it doesn't go in the vtable */
 632           continue;
 633         }
 634
 635       _Jv_Method *orig_meth = _Jv_LookupDeclaredMethod (super_class,
 636                                                         this_meth->name,
 637                                                         this_meth->signature);
 638
 639       if (orig_meth == 0)
 640         {
 641           // new methods that are final, also don't go in the vtable
 642           if ((this_meth->accflags & Modifier::FINAL) != 0)
 643             continue;
 644
 645           new_method_count += 1;
 646           continue;
 647         }
 648
 649       if ((orig_meth->accflags & (Modifier::STATIC
 650                                   | Modifier::PRIVATE
 651                                   | Modifier::FINAL)) != 0
 652           || ((orig_meth->accflags & Modifier::ABSTRACT) == 0
 653               && (this_meth->accflags & Modifier::ABSTRACT) != 0
 654               && (klass->accflags & Modifier::ABSTRACT) == 0))
 655         {
 656           clz->state = JV_STATE_ERROR;
 657           clz->notifyAll ();
 658           JvThrow (new java::lang::IncompatibleClassChangeError
 659                            (clz->getName ()));
 660         }
 661
 662       /* FIXME: At this point, if (loader != super_class->loader), we
 663        * need to "impose class loader constraints" for the types
 664        * involved in the signature of this method */
 665     }
 666
 667   /* determine size */
 668   int vtable_count = (super_class->vtable_method_count) + new_method_count;
 669   clz->vtable_method_count = vtable_count;
 670
 671   /* allocate vtable structure */
 672   _Jv_VTable *vtable = (_Jv_VTable*)
 673     _Jv_AllocBytesChecked (sizeof (_Jv_VTable)
 674                            + (sizeof (void*) * (vtable_count)));
 675   vtable->clas = clz;
 676
 677   /* copy super class' vtable entries (index 0 goes unused). */
 678   memcpy ((void*)&vtable->method[1],
 679           (void*)&super_class->vtable->method[1],
 680           sizeof (void*) * super_class->vtable_method_count);
 681
 682   /* now, install our own vtable entries, reprise... */
 683   for (int i = 0; i < clz->method_count; i++)
 684     {
 685       _Jv_Method *this_meth = &clz->methods[i];
 686
 687       int index = _Jv_DetermineVTableIndex (clz,
 688                                             this_meth->name,
 689                                             this_meth->signature);
 690
 691       if (index == 0)
 692         throw_internal_error ("method now found in own class");
 693
 694       if (index != -1)
 695         {
 696           if (index > clz->vtable_method_count+1)
 697             throw_internal_error ("vtable problem...");
 698
 699           if (clz->interpreted_methods[i] == 0)
 700             vtable->method[index] = (void*)&_Jv_abstractMethodError;
 701           else
 702             vtable->method[index] = this_meth->ncode;
 703         }
 704     }
 705
 706   /* finally, assign the vtable! */
 707   clz->vtable = vtable;
 708
 709   /* wooha! we're done. */
 710   clz->state = JV_STATE_PREPARED;
 711   clz->notifyAll ();
 712 }
 713
 714 /** Do static initialization for fields with a constant initializer */
 715 void
 716 _Jv_InitField (jobject obj, jclass klass, int index)
 717 {
 718   using namespace java::lang::reflect;
 719
 720   if (obj != 0 && klass == 0)
 721     klass = obj->getClass ();
 722
 723   if (!_Jv_IsInterpretedClass (klass))
 724     return;
 725
 726   _Jv_InterpClass *clz = (_Jv_InterpClass*)klass;
 727
 728   _Jv_Field * field = (&clz->fields[0]) + index;
 729
 730   if (index > clz->field_count)
 731     throw_internal_error ("field out of range");
 732
 733   int init = clz->field_initializers[index];
 734   if (init == 0)
 735     return;
 736
 737   _Jv_Constants *pool = &clz->constants;
 738   int tag = pool->tags[init];
 739
 740   if (! field->isResolved ())
 741     throw_internal_error ("initializing unresolved field");
 742
 743   if (obj==0 && ((field->flags & Modifier::STATIC) == 0))
 744     throw_internal_error ("initializing non-static field with no object");
 745
 746   void *addr = 0;
 747
 748   if ((field->flags & Modifier::STATIC) != 0)
 749     addr = (void*) field->u.addr;
 750   else
 751     addr = (void*) (((char*)obj) + field->u.boffset);
 752
 753   switch (tag)
 754     {
 755     case JV_CONSTANT_String:
 756       {
 757         _Jv_MonitorEnter (clz);
 758         jstring str;
 759         str = _Jv_NewStringUtf8Const (pool->data[init].utf8);
 760         pool->data[init].string = str;
 761         pool->tags[init] = JV_CONSTANT_ResolvedString;
 762         _Jv_MonitorExit (clz);
 763       }
 764       /* fall through */
 765
 766     case JV_CONSTANT_ResolvedString:
 767       if (! (field->type == &StringClass || field->type == &ObjectClass))
 768         throw_class_format_error ("string initialiser to non-string field");
 769
 770       *(jstring*)addr = pool->data[init].string;
 771       break;
 772
 773     case JV_CONSTANT_Integer:
 774       {
 775         int value = pool->data[init].i;
 776
 777         if (field->type == JvPrimClass (boolean))
 778           *(jboolean*)addr = (jboolean)value;
 779
 780         else if (field->type == JvPrimClass (byte))
 781           *(jbyte*)addr = (jbyte)value;
 782
 783         else if (field->type == JvPrimClass (char))
 784           *(jchar*)addr = (jchar)value;
 785
 786         else if (field->type == JvPrimClass (short))
 787           *(jshort*)addr = (jshort)value;
 788
 789         else if (field->type == JvPrimClass (int))
 790           *(jint*)addr = (jint)value;
 791
 792         else
 793           throw_class_format_error ("erroneous field initializer");
 794       }
 795       break;
 796
 797     case JV_CONSTANT_Long:
 798       if (field->type != JvPrimClass (long))
 799         throw_class_format_error ("erroneous field initializer");
 800
 801       *(jlong*)addr = _Jv_loadLong (&pool->data[init]);
 802       break;
 803
 804     case JV_CONSTANT_Float:
 805       if (field->type != JvPrimClass (float))
 806         throw_class_format_error ("erroneous field initializer");
 807
 808       *(jfloat*)addr = pool->data[init].f;
 809       break;
 810
 811     case JV_CONSTANT_Double:
 812       if (field->type != JvPrimClass (double))
 813         throw_class_format_error ("erroneous field initializer");
 814
 815       *(jdouble*)addr = _Jv_loadDouble (&pool->data[init]);
 816       break;
 817
 818     default:
 819       throw_class_format_error ("erroneous field initializer");
 820     }
 821 }
 822
 823 static int
 824 get_alignment_from_class (jclass klass)
 825 {
 826   if (klass == JvPrimClass (byte))
 827     return  __alignof__ (jbyte);
 828   else if (klass == JvPrimClass (short))
 829     return  __alignof__ (jshort);
 830   else if (klass == JvPrimClass (int))
 831     return  __alignof__ (jint);
 832   else if (klass == JvPrimClass (long))
 833     return  __alignof__ (jlong);
 834   else if (klass == JvPrimClass (boolean))
 835     return  __alignof__ (jboolean);
 836   else if (klass == JvPrimClass (char))
 837     return  __alignof__ (jchar);
 838   else if (klass == JvPrimClass (float))
 839     return  __alignof__ (jfloat);
 840   else if (klass == JvPrimClass (double))
 841     return  __alignof__ (jdouble);
 842   else
 843     return __alignof__ (jobject);
 844 }
 845
 846
 847 inline static unsigned char*
 848 skip_one_type (unsigned char* ptr)
 849 {
 850   int ch = *ptr++;
 851
 852   while (ch == '[')
 853     {
 854       ch = *ptr++;
 855     }
 856
 857   if (ch == 'L')
 858     {
 859       do { ch = *ptr++; } while (ch != ';');
 860     }
 861
 862   return ptr;
 863 }
 864
 865 static ffi_type*
 866 get_ffi_type_from_signature (unsigned char* ptr)
 867 {
 868   switch (*ptr)
 869     {
 870     case 'L':
 871     case '[':
 872       return &ffi_type_pointer;
 873       break;
 874
 875     case 'Z':
 876     case 'B':
 877       return &ffi_type_sint8;
 878       break;
 879
 880     case 'C':
 881       return &ffi_type_uint16;
 882       break;
 883
 884     case 'S':
 885       return &ffi_type_sint16;
 886       break;
 887
 888     case 'I':
 889       return &ffi_type_sint32;
 890       break;
 891
 892     case 'J':
 893       return &ffi_type_sint64;
 894       break;
 895
 896     case 'F':
 897       return &ffi_type_float;
 898       break;
 899
 900     case 'D':
 901       return &ffi_type_double;
 902       break;
 903
 904     case 'V':
 905       return &ffi_type_void;
 906       break;
 907     }
 908
 909   throw_internal_error ("unknown type in signature");
 910 }
 911
 912 /* this function yields the number of actual arguments, that is, if the
 913  * function is non-static, then one is added to the number of elements
 914  * found in the signature */
 915
 916 static int
 917 count_arguments (_Jv_Utf8Const *signature,
 918                  jboolean staticp)
 919 {
 920   unsigned char *ptr = (unsigned char*) signature->data;
 921   int arg_count = staticp ? 0 : 1;
 922
 923   /* first, count number of arguments */
 924
 925   // skip '('
 926   ptr++;
 927
 928   // count args
 929   while (*ptr != ')')
 930     {
 931       ptr = skip_one_type (ptr);
 932       arg_count += 1;
 933     }
 934
 935   return arg_count;
 936 }
 937
 938 /* This beast will build a cif, given the signature.  Memory for
 939  * the cif itself and for the argument types must be allocated by the
 940  * caller.
 941  */
 942
 943 static int
 944 init_cif (_Jv_Utf8Const* signature,
 945           int arg_count,
 946           jboolean staticp,
 947           ffi_cif *cif,
 948           ffi_type **arg_types)
 949 {
 950   unsigned char *ptr = (unsigned char*) signature->data;
 951
 952   int arg_index = 0;            // arg number
 953   int item_count = 0;           // stack-item count
 954
 955   // setup receiver
 956   if (!staticp)
 957     {
 958       arg_types[arg_index++] = &ffi_type_pointer;
 959       item_count += 1;
 960     }
 961
 962   // skip '('
 963   ptr++;
 964
 965   // assign arg types
 966   while (*ptr != ')')
 967     {
 968       arg_types[arg_index++] = get_ffi_type_from_signature (ptr);
 969
 970       if (*ptr == 'J' || *ptr == 'D')
 971         item_count += 2;
 972       else
 973         item_count += 1;
 974
 975       ptr = skip_one_type (ptr);
 976     }
 977
 978   // skip ')'
 979   ptr++;
 980   ffi_type *rtype = get_ffi_type_from_signature (ptr);
 981
 982   ptr = skip_one_type (ptr);
 983   if (ptr != (unsigned char*)signature->data + signature->length)
 984     throw_internal_error ("did not find end of signature");
 985
 986   if (ffi_prep_cif (cif, FFI_DEFAULT_ABI,
 987                     arg_count, rtype, arg_types) != FFI_OK)
 988     throw_internal_error ("ffi_prep_cif failed");
 989
 990   return item_count;
 991 }
 992
 993
 994 /* we put this one here, and not in interpret.cc because it
 995  * calls the utility routines count_arguments
 996  * which are static to this module.  The following struct defines the
 997  * layout we use for the stubs, it's only used in the ncode method. */
 998
 999 typedef struct {
1000   ffi_raw_closure  closure;
1001   ffi_cif   cif;
1002   ffi_type *arg_types[0];
1003 } ncode_closure;
1004
1005 typedef void (*ffi_closure_fun) (ffi_cif*,void*,ffi_raw*,void*);
1006
1007 void *
1008 _Jv_InterpMethod::ncode ()
1009 {
1010   using namespace java::lang::reflect;
1011
1012   if (self->ncode != 0)
1013     return self->ncode;
1014
1015   jboolean staticp = (self->accflags & Modifier::STATIC) != 0;
1016   int arg_count = count_arguments (self->signature, staticp);
1017
1018   ncode_closure *closure =
1019     (ncode_closure*)_Jv_AllocBytesChecked (sizeof (ncode_closure)
1020                                         + arg_count * sizeof (ffi_type*));
1021
1022   init_cif (self->signature,
1023             arg_count,
1024             staticp,
1025             &closure->cif,
1026             &closure->arg_types[0]);
1027
1028   ffi_closure_fun fun;
1029
1030   args_raw_size = ffi_raw_size (&closure->cif);
1031
1032   if ((self->accflags & Modifier::SYNCHRONIZED) != 0)
1033     {
1034       if (staticp)
1035         fun = (ffi_closure_fun)&_Jv_InterpMethod::run_synch_class;
1036       else
1037         fun = (ffi_closure_fun)&_Jv_InterpMethod::run_synch_object;
1038     }
1039   else
1040     {
1041       fun = (ffi_closure_fun)&_Jv_InterpMethod::run_normal;
1042     }
1043
1044   ffi_prep_raw_closure (&closure->closure,
1045                      &closure->cif,
1046                      fun,
1047                      (void*)this);
1048
1049   self->ncode = (void*)closure;
1050   return self->ncode;
1051 }
1052
1053
1054 /* A _Jv_ResolvedMethod is what is put in the constant pool for a
1055  * MethodRef or InterfacemethodRef.  */
1056 static _Jv_ResolvedMethod*
1057 _Jv_BuildResolvedMethod (_Jv_Method* method,
1058                          jclass      klass,
1059                          jboolean staticp,
1060                          jint vtable_index)
1061 {
1062   int arg_count = count_arguments (method->signature, staticp);
1063
1064   _Jv_ResolvedMethod* result = (_Jv_ResolvedMethod*)
1065     _Jv_AllocBytesChecked (sizeof (_Jv_ResolvedMethod)
1066                            + arg_count*sizeof (ffi_type*));
1067
1068   result->stack_item_count
1069     = init_cif (method->signature,
1070                 arg_count,
1071                 staticp,
1072                 &result->cif,
1073                 &result->arg_types[0]);
1074
1075   result->vtable_index        = vtable_index;
1076   result->method              = method;
1077   result->klass               = klass;
1078
1079   return result;
1080 }
1081
1082
1083 static void
1084 throw_class_format_error (jstring msg)
1085 {
1086   if (msg == 0)
1087     JvThrow (new java::lang::ClassFormatError);
1088   else
1089     JvThrow (new java::lang::ClassFormatError (msg));
1090 }
1091
1092 static void
1093 throw_class_format_error (char *msg)
1094 {
1095   throw_class_format_error (JvNewStringLatin1 (msg));
1096 }
1097
1098 static void
1099 throw_internal_error (char *msg)
1100 {
1101   JvThrow
1102     (new java::lang::InternalError (JvNewStringLatin1 (msg)));
1103 }
1104
1105
1106 #endif /* INTERPRETER */