libjava/resolve.cc

   1 // resolve.cc - Code for linking and resolving classes and pool entries.
   2
   3 /* Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004 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 #include <platform.h>
  15
  16 #include <java-interp.h>
  17
  18 #include <jvm.h>
  19 #include <gcj/cni.h>
  20 #include <string.h>
  21 #include <java-cpool.h>
  22 #include <java/lang/Class.h>
  23 #include <java/lang/String.h>
  24 #include <java/lang/StringBuffer.h>
  25 #include <java/lang/Thread.h>
  26 #include <java/lang/InternalError.h>
  27 #include <java/lang/VirtualMachineError.h>
  28 #include <java/lang/NoSuchFieldError.h>
  29 #include <java/lang/NoSuchMethodError.h>
  30 #include <java/lang/ClassFormatError.h>
  31 #include <java/lang/IllegalAccessError.h>
  32 #include <java/lang/AbstractMethodError.h>
  33 #include <java/lang/NoClassDefFoundError.h>
  34 #include <java/lang/IncompatibleClassChangeError.h>
  35 #include <java/lang/VMClassLoader.h>
  36 #include <java/lang/reflect/Modifier.h>
  37
  38 using namespace gcj;
  39
  40 void
  41 _Jv_ResolveField (_Jv_Field *field, java::lang::ClassLoader *loader)
  42 {
  43   if (! field->isResolved ())
  44     {
  45       _Jv_Utf8Const *sig = (_Jv_Utf8Const*)field->type;
  46       field->type = _Jv_FindClassFromSignature (sig->data, loader);
  47       field->flags &= ~_Jv_FIELD_UNRESOLVED_FLAG;
  48     }
  49 }
  50
  51 #ifdef INTERPRETER
  52
  53 static void throw_internal_error (char *msg)
  54         __attribute__ ((__noreturn__));
  55 static void throw_class_format_error (jstring msg)
  56         __attribute__ ((__noreturn__));
  57 static void throw_class_format_error (char *msg)
  58         __attribute__ ((__noreturn__));
  59
  60 static int get_alignment_from_class (jclass);
  61
  62 static _Jv_ResolvedMethod*
  63 _Jv_BuildResolvedMethod (_Jv_Method*,
  64                          jclass,
  65                          jboolean,
  66                          jint);
  67
  68
  69 static void throw_incompatible_class_change_error (jstring msg)
  70 {
  71   throw new java::lang::IncompatibleClassChangeError (msg);
  72 }
  73
  74 _Jv_word
  75 _Jv_ResolvePoolEntry (jclass klass, int index)
  76 {
  77   using namespace java::lang::reflect;
  78
  79   _Jv_Constants *pool = &klass->constants;
  80
  81   if ((pool->tags[index] & JV_CONSTANT_ResolvedFlag) != 0)
  82     return pool->data[index];
  83
  84   switch (pool->tags[index]) {
  85   case JV_CONSTANT_Class:
  86     {
  87       _Jv_Utf8Const *name = pool->data[index].utf8;
  88
  89       jclass found;
  90       if (name->data[0] == '[')
  91         found = _Jv_FindClassFromSignature (&name->data[0],
  92                                             klass->loader);
  93       else
  94         found = _Jv_FindClass (name, klass->loader);
  95
  96       if (! found)
  97         {
  98           jstring str = _Jv_NewStringUTF (name->data);
  99           // This exception is specified in JLS 2nd Ed, section 5.1.
 100           throw new java::lang::NoClassDefFoundError (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               if (_Jv_CheckAccess (klass, cls, field->flags))
 171                 {
 172                   /* resove the field using the class' own loader
 173                      if necessary */
 174
 175                   if (!field->isResolved ())
 176                     _Jv_ResolveField (field, cls->loader);
 177
 178                   if (field_type != 0 && field->type != field_type)
 179                     throw new java::lang::LinkageError
 180                       (JvNewStringLatin1
 181                        ("field type mismatch with different loaders"));
 182
 183                   the_field = field;
 184                   goto end_of_field_search;
 185                 }
 186               else
 187                 {
 188                   java::lang::StringBuffer *sb
 189                     = new java::lang::StringBuffer ();
 190                   sb->append(klass->getName());
 191                   sb->append(JvNewStringLatin1(": "));
 192                   sb->append(cls->getName());
 193                   sb->append(JvNewStringLatin1("."));
 194                   sb->append(_Jv_NewStringUtf8Const (field_name));
 195                   throw new java::lang::IllegalAccessError(sb->toString());
 196                 }
 197             }
 198         }
 199
 200     end_of_field_search:
 201       if (the_field == 0)
 202         {
 203           java::lang::StringBuffer *sb = new java::lang::StringBuffer();
 204           sb->append(JvNewStringLatin1("field "));
 205           sb->append(owner->getName());
 206           sb->append(JvNewStringLatin1("."));
 207           sb->append(_Jv_NewStringUTF(field_name->data));
 208           sb->append(JvNewStringLatin1(" was not found."));
 209           throw_incompatible_class_change_error(sb->toString());
 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       _Jv_Method *the_method = 0;
 238       jclass found_class = 0;
 239
 240       // First search the class itself.
 241       the_method = _Jv_SearchMethodInClass (owner, klass,
 242                                             method_name, method_signature);
 243
 244       if (the_method != 0)
 245         {
 246           found_class = owner;
 247           goto end_of_method_search;
 248         }
 249
 250       // If we are resolving an interface method, search the
 251       // interface's superinterfaces (A superinterface is not an
 252       // interface's superclass - a superinterface is implemented by
 253       // 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 (the_method == 0)
 304         {
 305           java::lang::StringBuffer *sb = new java::lang::StringBuffer();
 306           sb->append(JvNewStringLatin1("method "));
 307           sb->append(owner->getName());
 308           sb->append(JvNewStringLatin1("."));
 309           sb->append(_Jv_NewStringUTF(method_name->data));
 310           sb->append(JvNewStringLatin1(" was not found."));
 311           throw new java::lang::NoSuchMethodError (sb->toString());
 312         }
 313
 314       int vtable_index = -1;
 315       if (pool->tags[index] != JV_CONSTANT_InterfaceMethodref)
 316         vtable_index = (jshort)the_method->index;
 317
 318       pool->data[index].rmethod =
 319         _Jv_BuildResolvedMethod(the_method,
 320                                 found_class,
 321                                 (the_method->accflags & Modifier::STATIC) != 0,
 322                                 vtable_index);
 323       pool->tags[index] |= JV_CONSTANT_ResolvedFlag;
 324     }
 325     break;
 326
 327   }
 328
 329   return pool->data[index];
 330 }
 331
 332 // Find a method declared in the cls that is referenced from klass and
 333 // perform access checks.
 334 _Jv_Method *
 335 _Jv_SearchMethodInClass (jclass cls, jclass klass,
 336                          _Jv_Utf8Const *method_name,
 337                          _Jv_Utf8Const *method_signature)
 338 {
 339   using namespace java::lang::reflect;
 340
 341   for (int i = 0;  i < cls->method_count;  i++)
 342     {
 343       _Jv_Method *method = &cls->methods[i];
 344       if (   (!_Jv_equalUtf8Consts (method->name,
 345                                     method_name))
 346           || (!_Jv_equalUtf8Consts (method->signature,
 347                                     method_signature)))
 348         continue;
 349
 350       if (_Jv_CheckAccess (klass, cls, method->accflags))
 351         return method;
 352       else
 353         {
 354           java::lang::StringBuffer *sb = new java::lang::StringBuffer();
 355           sb->append(klass->getName());
 356           sb->append(JvNewStringLatin1(": "));
 357           sb->append(cls->getName());
 358           sb->append(JvNewStringLatin1("."));
 359           sb->append(_Jv_NewStringUTF(method_name->data));
 360           sb->append(_Jv_NewStringUTF(method_signature->data));
 361           throw new java::lang::IllegalAccessError (sb->toString());
 362         }
 363     }
 364   return 0;
 365 }
 366
 367 // A helper for _Jv_PrepareClass.  This adds missing `Miranda methods'
 368 // to a class.
 369 void
 370 _Jv_PrepareMissingMethods (jclass base, jclass iface_class)
 371 {
 372   _Jv_InterpClass *interp_base = (_Jv_InterpClass *) base->aux_info;
 373   for (int i = 0; i < iface_class->interface_count; ++i)
 374     {
 375       for (int j = 0; j < iface_class->interfaces[i]->method_count; ++j)
 376         {
 377           _Jv_Method *meth = &iface_class->interfaces[i]->methods[j];
 378           // Don't bother with <clinit>.
 379           if (meth->name->data[0] == '<')
 380             continue;
 381           _Jv_Method *new_meth = _Jv_LookupDeclaredMethod (base, meth->name,
 382                                                            meth->signature);
 383           if (! new_meth)
 384             {
 385               // We assume that such methods are very unlikely, so we
 386               // just reallocate the method array each time one is
 387               // found.  This greatly simplifies the searching --
 388               // otherwise we have to make sure that each such method
 389               // found is really unique among all superinterfaces.
 390               int new_count = base->method_count + 1;
 391               _Jv_Method *new_m
 392                 = (_Jv_Method *) _Jv_AllocBytes (sizeof (_Jv_Method)
 393                                                  * new_count);
 394               memcpy (new_m, base->methods,
 395                       sizeof (_Jv_Method) * base->method_count);
 396
 397               // Add new method.
 398               new_m[base->method_count] = *meth;
 399               new_m[base->method_count].index = (_Jv_ushort) -1;
 400               new_m[base->method_count].accflags
 401                 |= java::lang::reflect::Modifier::INVISIBLE;
 402
 403               _Jv_MethodBase **new_im
 404                 = (_Jv_MethodBase **) _Jv_AllocBytes (sizeof (_Jv_MethodBase *)
 405                                                       * new_count);
 406               memcpy (new_im, interp_base->interpreted_methods,
 407                       sizeof (_Jv_MethodBase *) * base->method_count);
 408
 409               base->methods = new_m;
 410               interp_base->interpreted_methods = new_im;
 411               base->method_count = new_count;
 412             }
 413         }
 414
 415       _Jv_PrepareMissingMethods (base, iface_class->interfaces[i]);
 416     }
 417 }
 418
 419 void
 420 _Jv_PrepareClass(jclass klass)
 421 {
 422   using namespace java::lang::reflect;
 423
 424  /*
 425   * The job of this function is to: 1) assign storage to fields, and 2)
 426   * build the vtable.  static fields are assigned real memory, instance
 427   * fields are assigned offsets.
 428   *
 429   * NOTE: we have a contract with the garbage collector here.  Static
 430   * reference fields must not be resolved, until after they have storage
 431   * assigned which is the check used by the collector to see if it
 432   * should indirect the static field reference and mark the object
 433   * pointed to.
 434   *
 435   * Most fields are resolved lazily (i.e. have their class-type
 436   * assigned) when they are accessed the first time by calling as part
 437   * of _Jv_ResolveField, which is allways called after _Jv_PrepareClass.
 438   * Static fields with initializers are resolved as part of this
 439   * function, as are fields with primitive types.
 440   */
 441
 442   if (! _Jv_IsInterpretedClass (klass))
 443     return;
 444
 445   if (klass->state >= JV_STATE_PREPARED)
 446     return;
 447
 448   // Make sure super-class is linked.  This involves taking a lock on
 449   // the super class, so we use the Java method resolveClass, which
 450   // will unlock it properly, should an exception happen.  If there's
 451   // no superclass, do nothing -- Object will already have been
 452   // resolved.
 453
 454   if (klass->superclass)
 455     java::lang::VMClassLoader::resolveClass (klass->superclass);
 456
 457   _Jv_InterpClass *iclass = (_Jv_InterpClass*)klass->aux_info;
 458
 459   /************ PART ONE: OBJECT LAYOUT ***************/
 460
 461   // Compute the alignment for this type by searching through the
 462   // superclasses and finding the maximum required alignment.  We
 463   // could consider caching this in the Class.
 464   int max_align = __alignof__ (java::lang::Object);
 465   jclass super = klass->superclass;
 466   while (super != NULL)
 467     {
 468       int num = JvNumInstanceFields (super);
 469       _Jv_Field *field = JvGetFirstInstanceField (super);
 470       while (num > 0)
 471         {
 472           int field_align = get_alignment_from_class (field->type);
 473           if (field_align > max_align)
 474             max_align = field_align;
 475           ++field;
 476           --num;
 477         }
 478       super = super->superclass;
 479     }
 480
 481   int instance_size;
 482   int static_size = 0;
 483
 484   // Although java.lang.Object is never interpreted, an interface can
 485   // have a null superclass.  Note that we have to lay out an
 486   // interface because it might have static fields.
 487   if (klass->superclass)
 488     instance_size = klass->superclass->size();
 489   else
 490     instance_size = java::lang::Object::class$.size();
 491
 492   for (int i = 0; i < klass->field_count; i++)
 493     {
 494       int field_size;
 495       int field_align;
 496
 497       _Jv_Field *field = &klass->fields[i];
 498
 499       if (! field->isRef ())
 500         {
 501           // it's safe to resolve the field here, since it's
 502           // a primitive class, which does not cause loading to happen.
 503           _Jv_ResolveField (field, klass->loader);
 504
 505           field_size = field->type->size ();
 506           field_align = get_alignment_from_class (field->type);
 507         }
 508       else
 509         {
 510           field_size = sizeof (jobject);
 511           field_align = __alignof__ (jobject);
 512         }
 513
 514 #ifndef COMPACT_FIELDS
 515       field->bsize = field_size;
 516 #endif
 517
 518       if (field->flags & Modifier::STATIC)
 519         {
 520           /* this computes an offset into a region we'll allocate
 521              shortly, and then add this offset to the start address */
 522
 523           static_size        = ROUND (static_size, field_align);
 524           field->u.boffset   = static_size;
 525           static_size       += field_size;
 526         }
 527       else
 528         {
 529           instance_size      = ROUND (instance_size, field_align);
 530           field->u.boffset   = instance_size;
 531           instance_size     += field_size;
 532           if (field_align > max_align)
 533             max_align = field_align;
 534         }
 535     }
 536
 537   // Set the instance size for the class.  Note that first we round it
 538   // to the alignment required for this object; this keeps us in sync
 539   // with our current ABI.
 540   instance_size = ROUND (instance_size, max_align);
 541   klass->size_in_bytes = instance_size;
 542
 543   // allocate static memory
 544   if (static_size != 0)
 545     {
 546       char *static_data = (char*)_Jv_AllocBytes (static_size);
 547
 548       memset (static_data, 0, static_size);
 549
 550       for (int i = 0; i < klass->field_count; i++)
 551         {
 552           _Jv_Field *field = &klass->fields[i];
 553
 554           if ((field->flags & Modifier::STATIC) != 0)
 555             {
 556               field->u.addr  = static_data + field->u.boffset;
 557
 558               if (iclass->field_initializers[i] != 0)
 559                 {
 560                   _Jv_ResolveField (field, klass->loader);
 561                   _Jv_InitField (0, klass, i);
 562                 }
 563             }
 564         }
 565
 566       // now we don't need the field_initializers anymore, so let the
 567       // collector get rid of it!
 568
 569       iclass->field_initializers = 0;
 570     }
 571
 572   /************ PART TWO: VTABLE LAYOUT ***************/
 573
 574   /* preparation: build the vtable stubs (even interfaces can)
 575      have code -- for static constructors. */
 576   for (int i = 0; i < klass->method_count; i++)
 577     {
 578       _Jv_MethodBase *imeth = iclass->interpreted_methods[i];
 579
 580       if ((klass->methods[i].accflags & Modifier::NATIVE) != 0)
 581         {
 582           // You might think we could use a virtual `ncode' method in
 583           // the _Jv_MethodBase and unify the native and non-native
 584           // cases.  Well, we can't, because we don't allocate these
 585           // objects using `new', and thus they don't get a vtable.
 586           _Jv_JNIMethod *jnim = reinterpret_cast<_Jv_JNIMethod *> (imeth);
 587           klass->methods[i].ncode = jnim->ncode ();
 588         }
 589       else if (imeth != 0)              // it could be abstract
 590         {
 591           _Jv_InterpMethod *im = reinterpret_cast<_Jv_InterpMethod *> (imeth);
 592           _Jv_VerifyMethod (im);
 593           klass->methods[i].ncode = im->ncode ();
 594
 595           // Resolve ctable entries pointing to this method.  See
 596           // _Jv_Defer_Resolution.
 597           void **code = (void **)imeth->deferred;
 598           while (code)
 599             {
 600               void **target = (void **)*code;
 601               *code = klass->methods[i].ncode;
 602               code = target;
 603             }
 604         }
 605     }
 606
 607   if ((klass->accflags & Modifier::INTERFACE))
 608     {
 609       klass->state = JV_STATE_PREPARED;
 610       klass->notifyAll ();
 611       return;
 612     }
 613
 614   // A class might have so-called "Miranda methods".  This is a method
 615   // that is declared in an interface and not re-declared in an
 616   // abstract class.  Some compilers don't emit declarations for such
 617   // methods in the class; this will give us problems since we expect
 618   // a declaration for any method requiring a vtable entry.  We handle
 619   // this here by searching for such methods and constructing new
 620   // internal declarations for them.  We only need to do this for
 621   // abstract classes.
 622   if ((klass->accflags & Modifier::ABSTRACT))
 623     _Jv_PrepareMissingMethods (klass, klass);
 624
 625   klass->vtable_method_count = -1;
 626   _Jv_MakeVTable (klass);
 627
 628   /* wooha! we're done. */
 629   klass->state = JV_STATE_PREPARED;
 630   klass->notifyAll ();
 631 }
 632
 633 /** Do static initialization for fields with a constant initializer */
 634 void
 635 _Jv_InitField (jobject obj, jclass klass, int index)
 636 {
 637   using namespace java::lang::reflect;
 638
 639   if (obj != 0 && klass == 0)
 640     klass = obj->getClass ();
 641
 642   if (!_Jv_IsInterpretedClass (klass))
 643     return;
 644
 645   _Jv_InterpClass *iclass = (_Jv_InterpClass*)klass->aux_info;
 646
 647   _Jv_Field * field = (&klass->fields[0]) + index;
 648
 649   if (index > klass->field_count)
 650     throw_internal_error ("field out of range");
 651
 652   int init = iclass->field_initializers[index];
 653   if (init == 0)
 654     return;
 655
 656   _Jv_Constants *pool = &klass->constants;
 657   int tag = pool->tags[init];
 658
 659   if (! field->isResolved ())
 660     throw_internal_error ("initializing unresolved field");
 661
 662   if (obj==0 && ((field->flags & Modifier::STATIC) == 0))
 663     throw_internal_error ("initializing non-static field with no object");
 664
 665   void *addr = 0;
 666
 667   if ((field->flags & Modifier::STATIC) != 0)
 668     addr = (void*) field->u.addr;
 669   else
 670     addr = (void*) (((char*)obj) + field->u.boffset);
 671
 672   switch (tag)
 673     {
 674     case JV_CONSTANT_String:
 675       {
 676         _Jv_MonitorEnter (klass);
 677         jstring str;
 678         str = _Jv_NewStringUtf8Const (pool->data[init].utf8);
 679         pool->data[init].string = str;
 680         pool->tags[init] = JV_CONSTANT_ResolvedString;
 681         _Jv_MonitorExit (klass);
 682       }
 683       /* fall through */
 684
 685     case JV_CONSTANT_ResolvedString:
 686       if (! (field->type == &StringClass
 687              || field->type == &java::lang::Class::class$))
 688         throw_class_format_error ("string initialiser to non-string field");
 689
 690       *(jstring*)addr = pool->data[init].string;
 691       break;
 692
 693     case JV_CONSTANT_Integer:
 694       {
 695         int value = pool->data[init].i;
 696
 697         if (field->type == JvPrimClass (boolean))
 698           *(jboolean*)addr = (jboolean)value;
 699
 700         else if (field->type == JvPrimClass (byte))
 701           *(jbyte*)addr = (jbyte)value;
 702
 703         else if (field->type == JvPrimClass (char))
 704           *(jchar*)addr = (jchar)value;
 705
 706         else if (field->type == JvPrimClass (short))
 707           *(jshort*)addr = (jshort)value;
 708
 709         else if (field->type == JvPrimClass (int))
 710           *(jint*)addr = (jint)value;
 711
 712         else
 713           throw_class_format_error ("erroneous field initializer");
 714       }
 715       break;
 716
 717     case JV_CONSTANT_Long:
 718       if (field->type != JvPrimClass (long))
 719         throw_class_format_error ("erroneous field initializer");
 720
 721       *(jlong*)addr = _Jv_loadLong (&pool->data[init]);
 722       break;
 723
 724     case JV_CONSTANT_Float:
 725       if (field->type != JvPrimClass (float))
 726         throw_class_format_error ("erroneous field initializer");
 727
 728       *(jfloat*)addr = pool->data[init].f;
 729       break;
 730
 731     case JV_CONSTANT_Double:
 732       if (field->type != JvPrimClass (double))
 733         throw_class_format_error ("erroneous field initializer");
 734
 735       *(jdouble*)addr = _Jv_loadDouble (&pool->data[init]);
 736       break;
 737
 738     default:
 739       throw_class_format_error ("erroneous field initializer");
 740     }
 741 }
 742
 743 template<typename T>
 744 struct aligner
 745 {
 746   T field;
 747 };
 748
 749 #define ALIGNOF(TYPE) (__alignof__ (((aligner<TYPE> *) 0)->field))
 750
 751 // This returns the alignment of a type as it would appear in a
 752 // structure.  This can be different from the alignment of the type
 753 // itself.  For instance on x86 double is 8-aligned but struct{double}
 754 // is 4-aligned.
 755 static int
 756 get_alignment_from_class (jclass klass)
 757 {
 758   if (klass == JvPrimClass (byte))
 759     return ALIGNOF (jbyte);
 760   else if (klass == JvPrimClass (short))
 761     return ALIGNOF (jshort);
 762   else if (klass == JvPrimClass (int))
 763     return ALIGNOF (jint);
 764   else if (klass == JvPrimClass (long))
 765     return ALIGNOF (jlong);
 766   else if (klass == JvPrimClass (boolean))
 767     return ALIGNOF (jboolean);
 768   else if (klass == JvPrimClass (char))
 769     return ALIGNOF (jchar);
 770   else if (klass == JvPrimClass (float))
 771     return ALIGNOF (jfloat);
 772   else if (klass == JvPrimClass (double))
 773     return ALIGNOF (jdouble);
 774   else
 775     return ALIGNOF (jobject);
 776 }
 777
 778
 779 inline static unsigned char*
 780 skip_one_type (unsigned char* ptr)
 781 {
 782   int ch = *ptr++;
 783
 784   while (ch == '[')
 785     {
 786       ch = *ptr++;
 787     }
 788
 789   if (ch == 'L')
 790     {
 791       do { ch = *ptr++; } while (ch != ';');
 792     }
 793
 794   return ptr;
 795 }
 796
 797 static ffi_type*
 798 get_ffi_type_from_signature (unsigned char* ptr)
 799 {
 800   switch (*ptr)
 801     {
 802     case 'L':
 803     case '[':
 804       return &ffi_type_pointer;
 805       break;
 806
 807     case 'Z':
 808       // On some platforms a bool is a byte, on others an int.
 809       if (sizeof (jboolean) == sizeof (jbyte))
 810         return &ffi_type_sint8;
 811       else
 812         {
 813           JvAssert (sizeof (jbyte) == sizeof (jint));
 814           return &ffi_type_sint32;
 815         }
 816       break;
 817
 818     case 'B':
 819       return &ffi_type_sint8;
 820       break;
 821
 822     case 'C':
 823       return &ffi_type_uint16;
 824       break;
 825
 826     case 'S':
 827       return &ffi_type_sint16;
 828       break;
 829
 830     case 'I':
 831       return &ffi_type_sint32;
 832       break;
 833
 834     case 'J':
 835       return &ffi_type_sint64;
 836       break;
 837
 838     case 'F':
 839       return &ffi_type_float;
 840       break;
 841
 842     case 'D':
 843       return &ffi_type_double;
 844       break;
 845
 846     case 'V':
 847       return &ffi_type_void;
 848       break;
 849     }
 850
 851   throw_internal_error ("unknown type in signature");
 852 }
 853
 854 /* this function yields the number of actual arguments, that is, if the
 855  * function is non-static, then one is added to the number of elements
 856  * found in the signature */
 857
 858 int
 859 _Jv_count_arguments (_Jv_Utf8Const *signature,
 860                      jboolean staticp)
 861 {
 862   unsigned char *ptr = (unsigned char*) signature->data;
 863   int arg_count = staticp ? 0 : 1;
 864
 865   /* first, count number of arguments */
 866
 867   // skip '('
 868   ptr++;
 869
 870   // count args
 871   while (*ptr != ')')
 872     {
 873       ptr = skip_one_type (ptr);
 874       arg_count += 1;
 875     }
 876
 877   return arg_count;
 878 }
 879
 880 /* This beast will build a cif, given the signature.  Memory for
 881  * the cif itself and for the argument types must be allocated by the
 882  * caller.
 883  */
 884
 885 static int
 886 init_cif (_Jv_Utf8Const* signature,
 887           int arg_count,
 888           jboolean staticp,
 889           ffi_cif *cif,
 890           ffi_type **arg_types,
 891           ffi_type **rtype_p)
 892 {
 893   unsigned char *ptr = (unsigned char*) signature->data;
 894
 895   int arg_index = 0;            // arg number
 896   int item_count = 0;           // stack-item count
 897
 898   // setup receiver
 899   if (!staticp)
 900     {
 901       arg_types[arg_index++] = &ffi_type_pointer;
 902       item_count += 1;
 903     }
 904
 905   // skip '('
 906   ptr++;
 907
 908   // assign arg types
 909   while (*ptr != ')')
 910     {
 911       arg_types[arg_index++] = get_ffi_type_from_signature (ptr);
 912
 913       if (*ptr == 'J' || *ptr == 'D')
 914         item_count += 2;
 915       else
 916         item_count += 1;
 917
 918       ptr = skip_one_type (ptr);
 919     }
 920
 921   // skip ')'
 922   ptr++;
 923   ffi_type *rtype = get_ffi_type_from_signature (ptr);
 924
 925   ptr = skip_one_type (ptr);
 926   if (ptr != (unsigned char*)signature->data + signature->length)
 927     throw_internal_error ("did not find end of signature");
 928
 929   if (ffi_prep_cif (cif, FFI_DEFAULT_ABI,
 930                     arg_count, rtype, arg_types) != FFI_OK)
 931     throw_internal_error ("ffi_prep_cif failed");
 932
 933   if (rtype_p != NULL)
 934     *rtype_p = rtype;
 935
 936   return item_count;
 937 }
 938
 939 #if FFI_NATIVE_RAW_API
 940 #   define FFI_PREP_RAW_CLOSURE ffi_prep_raw_closure
 941 #   define FFI_RAW_SIZE ffi_raw_size
 942 #else
 943 #   define FFI_PREP_RAW_CLOSURE ffi_prep_java_raw_closure
 944 #   define FFI_RAW_SIZE ffi_java_raw_size
 945 #endif
 946
 947 /* we put this one here, and not in interpret.cc because it
 948  * calls the utility routines _Jv_count_arguments
 949  * which are static to this module.  The following struct defines the
 950  * layout we use for the stubs, it's only used in the ncode method. */
 951
 952 typedef struct {
 953   ffi_raw_closure  closure;
 954   ffi_cif   cif;
 955   ffi_type *arg_types[0];
 956 } ncode_closure;
 957
 958 typedef void (*ffi_closure_fun) (ffi_cif*,void*,ffi_raw*,void*);
 959
 960 void *
 961 _Jv_InterpMethod::ncode ()
 962 {
 963   using namespace java::lang::reflect;
 964
 965   if (self->ncode != 0)
 966     return self->ncode;
 967
 968   jboolean staticp = (self->accflags & Modifier::STATIC) != 0;
 969   int arg_count = _Jv_count_arguments (self->signature, staticp);
 970
 971   ncode_closure *closure =
 972     (ncode_closure*)_Jv_AllocBytes (sizeof (ncode_closure)
 973                                         + arg_count * sizeof (ffi_type*));
 974
 975   init_cif (self->signature,
 976             arg_count,
 977             staticp,
 978             &closure->cif,
 979             &closure->arg_types[0],
 980             NULL);
 981
 982   ffi_closure_fun fun;
 983
 984   args_raw_size = FFI_RAW_SIZE (&closure->cif);
 985
 986   JvAssert ((self->accflags & Modifier::NATIVE) == 0);
 987
 988   if ((self->accflags & Modifier::SYNCHRONIZED) != 0)
 989     {
 990       if (staticp)
 991         fun = (ffi_closure_fun)&_Jv_InterpMethod::run_synch_class;
 992       else
 993         fun = (ffi_closure_fun)&_Jv_InterpMethod::run_synch_object;
 994     }
 995   else
 996     {
 997       if (staticp)
 998         fun = (ffi_closure_fun)&_Jv_InterpMethod::run_class;
 999       else
1000         fun = (ffi_closure_fun)&_Jv_InterpMethod::run_normal;
1001     }
1002
1003   FFI_PREP_RAW_CLOSURE (&closure->closure,
1004                         &closure->cif,
1005                         fun,
1006                         (void*)this);
1007
1008   self->ncode = (void*)closure;
1009   return self->ncode;
1010 }
1011
1012 void *
1013 _Jv_JNIMethod::ncode ()
1014 {
1015   using namespace java::lang::reflect;
1016
1017   if (self->ncode != 0)
1018     return self->ncode;
1019
1020   jboolean staticp = (self->accflags & Modifier::STATIC) != 0;
1021   int arg_count = _Jv_count_arguments (self->signature, staticp);
1022
1023   ncode_closure *closure =
1024     (ncode_closure*)_Jv_AllocBytes (sizeof (ncode_closure)
1025                                     + arg_count * sizeof (ffi_type*));
1026
1027   ffi_type *rtype;
1028   init_cif (self->signature,
1029             arg_count,
1030             staticp,
1031             &closure->cif,
1032             &closure->arg_types[0],
1033             &rtype);
1034
1035   ffi_closure_fun fun;
1036
1037   args_raw_size = FFI_RAW_SIZE (&closure->cif);
1038
1039   // Initialize the argument types and CIF that represent the actual
1040   // underlying JNI function.
1041   int extra_args = 1;
1042   if ((self->accflags & Modifier::STATIC))
1043     ++extra_args;
1044   jni_arg_types = (ffi_type **) _Jv_Malloc ((extra_args + arg_count)
1045                                             * sizeof (ffi_type *));
1046   int offset = 0;
1047   jni_arg_types[offset++] = &ffi_type_pointer;
1048   if ((self->accflags & Modifier::STATIC))
1049     jni_arg_types[offset++] = &ffi_type_pointer;
1050   memcpy (&jni_arg_types[offset], &closure->arg_types[0],
1051           arg_count * sizeof (ffi_type *));
1052
1053   if (ffi_prep_cif (&jni_cif, _Jv_platform_ffi_abi,
1054                     extra_args + arg_count, rtype,
1055                     jni_arg_types) != FFI_OK)
1056     throw_internal_error ("ffi_prep_cif failed for JNI function");
1057
1058   JvAssert ((self->accflags & Modifier::NATIVE) != 0);
1059
1060   // FIXME: for now we assume that all native methods for
1061   // interpreted code use JNI.
1062   fun = (ffi_closure_fun) &_Jv_JNIMethod::call;
1063
1064   FFI_PREP_RAW_CLOSURE (&closure->closure,
1065                         &closure->cif,
1066                         fun,
1067                         (void*) this);
1068
1069   self->ncode = (void *) closure;
1070   return self->ncode;
1071 }
1072
1073
1074 /* A _Jv_ResolvedMethod is what is put in the constant pool for a
1075  * MethodRef or InterfacemethodRef.  */
1076 static _Jv_ResolvedMethod*
1077 _Jv_BuildResolvedMethod (_Jv_Method* method,
1078                          jclass      klass,
1079                          jboolean staticp,
1080                          jint vtable_index)
1081 {
1082   int arg_count = _Jv_count_arguments (method->signature, staticp);
1083
1084   _Jv_ResolvedMethod* result = (_Jv_ResolvedMethod*)
1085     _Jv_AllocBytes (sizeof (_Jv_ResolvedMethod)
1086                     + arg_count*sizeof (ffi_type*));
1087
1088   result->stack_item_count
1089     = init_cif (method->signature,
1090                 arg_count,
1091                 staticp,
1092                 &result->cif,
1093                 &result->arg_types[0],
1094                 NULL);
1095
1096   result->vtable_index        = vtable_index;
1097   result->method              = method;
1098   result->klass               = klass;
1099
1100   return result;
1101 }
1102
1103
1104 static void
1105 throw_class_format_error (jstring msg)
1106 {
1107   throw (msg
1108          ? new java::lang::ClassFormatError (msg)
1109          : new java::lang::ClassFormatError);
1110 }
1111
1112 static void
1113 throw_class_format_error (char *msg)
1114 {
1115   throw_class_format_error (JvNewStringLatin1 (msg));
1116 }
1117
1118 static void
1119 throw_internal_error (char *msg)
1120 {
1121   throw new java::lang::InternalError (JvNewStringLatin1 (msg));
1122 }
1123
1124
1125 #endif /* INTERPRETER */