libjava/resolve.cc

   1 // resolve.cc - Code for linking and resolving classes and pool entries.
   2
   3 /* Copyright (C) 1999, 2000, 2001, 2002, 2003 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/reflect/Modifier.h>
  36
  37 using namespace gcj;
  38
  39 void
  40 _Jv_ResolveField (_Jv_Field *field, java::lang::ClassLoader *loader)
  41 {
  42   if (! field->isResolved ())
  43     {
  44       _Jv_Utf8Const *sig = (_Jv_Utf8Const*)field->type;
  45       field->type = _Jv_FindClassFromSignature (sig->data, loader);
  46       field->flags &= ~_Jv_FIELD_UNRESOLVED_FLAG;
  47     }
  48 }
  49
  50 #ifdef INTERPRETER
  51
  52 static void throw_internal_error (char *msg)
  53         __attribute__ ((__noreturn__));
  54 static void throw_class_format_error (jstring msg)
  55         __attribute__ ((__noreturn__));
  56 static void throw_class_format_error (char *msg)
  57         __attribute__ ((__noreturn__));
  58
  59 static int get_alignment_from_class (jclass);
  60
  61 static _Jv_ResolvedMethod*
  62 _Jv_BuildResolvedMethod (_Jv_Method*,
  63                          jclass,
  64                          jboolean,
  65                          jint);
  66
  67
  68 static void throw_incompatible_class_change_error (jstring msg)
  69 {
  70   throw new java::lang::IncompatibleClassChangeError (msg);
  71 }
  72
  73 _Jv_word
  74 _Jv_ResolvePoolEntry (jclass klass, int index)
  75 {
  76   using namespace java::lang::reflect;
  77
  78   _Jv_Constants *pool = &klass->constants;
  79
  80   if ((pool->tags[index] & JV_CONSTANT_ResolvedFlag) != 0)
  81     return pool->data[index];
  82
  83   switch (pool->tags[index]) {
  84   case JV_CONSTANT_Class:
  85     {
  86       _Jv_Utf8Const *name = pool->data[index].utf8;
  87
  88       jclass found;
  89       if (name->data[0] == '[')
  90         found = _Jv_FindClassFromSignature (&name->data[0],
  91                                             klass->loader);
  92       else
  93         found = _Jv_FindClass (name, klass->loader);
  94
  95       if (! found)
  96         {
  97           jstring str = _Jv_NewStringUTF (name->data);
  98           // This exception is specified in JLS 2nd Ed, section 5.1.
  99           throw new java::lang::NoClassDefFoundError (str);
 100         }
 101
 102       if ((found->accflags & Modifier::PUBLIC) == Modifier::PUBLIC
 103           || (_Jv_ClassNameSamePackage (found->name,
 104                                         klass->name)))
 105         {
 106           pool->data[index].clazz = found;
 107           pool->tags[index] |= JV_CONSTANT_ResolvedFlag;
 108         }
 109       else
 110         {
 111           throw new java::lang::IllegalAccessError (found->getName());
 112         }
 113     }
 114     break;
 115
 116   case JV_CONSTANT_String:
 117     {
 118       jstring str;
 119       str = _Jv_NewStringUtf8Const (pool->data[index].utf8);
 120       pool->data[index].o = str;
 121       pool->tags[index] |= JV_CONSTANT_ResolvedFlag;
 122     }
 123     break;
 124
 125
 126   case JV_CONSTANT_Fieldref:
 127     {
 128       _Jv_ushort class_index, name_and_type_index;
 129       _Jv_loadIndexes (&pool->data[index],
 130                        class_index,
 131                        name_and_type_index);
 132       jclass owner = (_Jv_ResolvePoolEntry (klass, class_index)).clazz;
 133
 134       if (owner != klass)
 135         _Jv_InitClass (owner);
 136
 137       _Jv_ushort name_index, type_index;
 138       _Jv_loadIndexes (&pool->data[name_and_type_index],
 139                        name_index,
 140                        type_index);
 141
 142       _Jv_Utf8Const *field_name = pool->data[name_index].utf8;
 143       _Jv_Utf8Const *field_type_name = pool->data[type_index].utf8;
 144
 145       // FIXME: The implementation of this function
 146       // (_Jv_FindClassFromSignature) will generate an instance of
 147       // _Jv_Utf8Const for each call if the field type is a class name
 148       // (Lxx.yy.Z;).  This may be too expensive to do for each and
 149       // every fieldref being resolved.  For now, we fix the problem by
 150       // only doing it when we have a loader different from the class
 151       // declaring the field.
 152
 153       jclass field_type = 0;
 154
 155       if (owner->loader != klass->loader)
 156         field_type = _Jv_FindClassFromSignature (field_type_name->data,
 157                                                  klass->loader);
 158
 159       _Jv_Field* the_field = 0;
 160
 161       for (jclass cls = owner; cls != 0; cls = cls->getSuperclass ())
 162         {
 163           for (int i = 0;  i < cls->field_count;  i++)
 164             {
 165               _Jv_Field *field = &cls->fields[i];
 166               if (! _Jv_equalUtf8Consts (field->name, field_name))
 167                 continue;
 168
 169               // now, check field access.
 170
 171               if (   (cls == klass)
 172                   || ((field->flags & Modifier::PUBLIC) != 0)
 173                   || (((field->flags & Modifier::PROTECTED) != 0)
 174                       && cls->isAssignableFrom (klass))
 175                   || (((field->flags & Modifier::PRIVATE) == 0)
 176                       && _Jv_ClassNameSamePackage (cls->name,
 177                                                    klass->name)))
 178                 {
 179                   /* resove the field using the class' own loader
 180                      if necessary */
 181
 182                   if (!field->isResolved ())
 183                     _Jv_ResolveField (field, cls->loader);
 184
 185                   if (field_type != 0 && field->type != field_type)
 186                     throw new java::lang::LinkageError
 187                       (JvNewStringLatin1
 188                        ("field type mismatch with different loaders"));
 189
 190                   the_field = field;
 191                   goto end_of_field_search;
 192                 }
 193               else
 194                 {
 195                   throw new java::lang::IllegalAccessError;
 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 (cls == klass
 351           || ((method->accflags & Modifier::PUBLIC) != 0)
 352           || (((method->accflags & Modifier::PROTECTED) != 0)
 353               && cls->isAssignableFrom (klass))
 354           || (((method->accflags & Modifier::PRIVATE) == 0)
 355               && _Jv_ClassNameSamePackage (cls->name,
 356                                            klass->name)))
 357         {
 358           return method;
 359         }
 360       else
 361         {
 362           throw new java::lang::IllegalAccessError;
 363         }
 364     }
 365   return 0;
 366 }
 367
 368 // A helper for _Jv_PrepareClass.  This adds missing `Miranda methods'
 369 // to a class.
 370 void
 371 _Jv_PrepareMissingMethods (jclass base2, jclass iface_class)
 372 {
 373   _Jv_InterpClass *base = reinterpret_cast<_Jv_InterpClass *> (base2);
 374   for (int i = 0; i < iface_class->interface_count; ++i)
 375     {
 376       for (int j = 0; j < iface_class->interfaces[i]->method_count; ++j)
 377         {
 378           _Jv_Method *meth = &iface_class->interfaces[i]->methods[j];
 379           // Don't bother with <clinit>.
 380           if (meth->name->data[0] == '<')
 381             continue;
 382           _Jv_Method *new_meth = _Jv_LookupDeclaredMethod (base, meth->name,
 383                                                            meth->signature);
 384           if (! new_meth)
 385             {
 386               // We assume that such methods are very unlikely, so we
 387               // just reallocate the method array each time one is
 388               // found.  This greatly simplifies the searching --
 389               // otherwise we have to make sure that each such method
 390               // found is really unique among all superinterfaces.
 391               int new_count = base->method_count + 1;
 392               _Jv_Method *new_m
 393                 = (_Jv_Method *) _Jv_AllocBytes (sizeof (_Jv_Method)
 394                                                  * new_count);
 395               memcpy (new_m, base->methods,
 396                       sizeof (_Jv_Method) * base->method_count);
 397
 398               // Add new method.
 399               new_m[base->method_count] = *meth;
 400               new_m[base->method_count].index = (_Jv_ushort) -1;
 401               new_m[base->method_count].accflags
 402                 |= java::lang::reflect::Modifier::INVISIBLE;
 403
 404               _Jv_MethodBase **new_im
 405                 = (_Jv_MethodBase **) _Jv_AllocBytes (sizeof (_Jv_MethodBase *)
 406                                                       * new_count);
 407               memcpy (new_im, base->interpreted_methods,
 408                       sizeof (_Jv_MethodBase *) * base->method_count);
 409
 410               base->methods = new_m;
 411               base->interpreted_methods = new_im;
 412               base->method_count = new_count;
 413             }
 414         }
 415
 416       _Jv_PrepareMissingMethods (base, iface_class->interfaces[i]);
 417     }
 418 }
 419
 420 void
 421 _Jv_PrepareClass(jclass klass)
 422 {
 423   using namespace java::lang::reflect;
 424
 425  /*
 426   * The job of this function is to: 1) assign storage to fields, and 2)
 427   * build the vtable.  static fields are assigned real memory, instance
 428   * fields are assigned offsets.
 429   *
 430   * NOTE: we have a contract with the garbage collector here.  Static
 431   * reference fields must not be resolved, until after they have storage
 432   * assigned which is the check used by the collector to see if it
 433   * should indirect the static field reference and mark the object
 434   * pointed to.
 435   *
 436   * Most fields are resolved lazily (i.e. have their class-type
 437   * assigned) when they are accessed the first time by calling as part
 438   * of _Jv_ResolveField, which is allways called after _Jv_PrepareClass.
 439   * Static fields with initializers are resolved as part of this
 440   * function, as are fields with primitive types.
 441   */
 442
 443   if (! _Jv_IsInterpretedClass (klass))
 444     return;
 445
 446   if (klass->state >= JV_STATE_PREPARED)
 447     return;
 448
 449   // Make sure super-class is linked.  This involves taking a lock on
 450   // the super class, so we use the Java method resolveClass, which
 451   // will unlock it properly, should an exception happen.  If there's
 452   // no superclass, do nothing -- Object will already have been
 453   // resolved.
 454
 455   if (klass->superclass)
 456     java::lang::ClassLoader::resolveClass0 (klass->superclass);
 457
 458   _Jv_InterpClass *clz = (_Jv_InterpClass*)klass;
 459
 460   /************ PART ONE: OBJECT LAYOUT ***************/
 461
 462   int instance_size;
 463   int static_size;
 464
 465   // Although java.lang.Object is never interpreted, an interface can
 466   // have a null superclass.
 467   if (clz->superclass)
 468     instance_size = clz->superclass->size();
 469   else
 470     instance_size = java::lang::Object::class$.size();
 471   static_size   = 0;
 472
 473   for (int i = 0; i < clz->field_count; i++)
 474     {
 475       int field_size;
 476       int field_align;
 477
 478       _Jv_Field *field = &clz->fields[i];
 479
 480       if (! field->isRef ())
 481         {
 482           // it's safe to resolve the field here, since it's
 483           // a primitive class, which does not cause loading to happen.
 484           _Jv_ResolveField (field, clz->loader);
 485
 486           field_size = field->type->size ();
 487           field_align = get_alignment_from_class (field->type);
 488         }
 489       else
 490         {
 491           field_size = sizeof (jobject);
 492           field_align = __alignof__ (jobject);
 493         }
 494
 495 #ifndef COMPACT_FIELDS
 496       field->bsize = field_size;
 497 #endif
 498
 499       if (field->flags & Modifier::STATIC)
 500         {
 501           /* this computes an offset into a region we'll allocate
 502              shortly, and then add this offset to the start address */
 503
 504           static_size        = ROUND (static_size, field_align);
 505           field->u.boffset   = static_size;
 506           static_size       += field_size;
 507         }
 508       else
 509         {
 510           instance_size      = ROUND (instance_size, field_align);
 511           field->u.boffset   = instance_size;
 512           instance_size     += field_size;
 513         }
 514     }
 515
 516   // set the instance size for the class
 517   clz->size_in_bytes = instance_size;
 518
 519   // allocate static memory
 520   if (static_size != 0)
 521     {
 522       char *static_data = (char*)_Jv_AllocBytes (static_size);
 523
 524       memset (static_data, 0, static_size);
 525
 526       for (int i = 0; i < clz->field_count; i++)
 527         {
 528           _Jv_Field *field = &clz->fields[i];
 529
 530           if ((field->flags & Modifier::STATIC) != 0)
 531             {
 532               field->u.addr  = static_data + field->u.boffset;
 533
 534               if (clz->field_initializers[i] != 0)
 535                 {
 536                   _Jv_ResolveField (field, clz->loader);
 537                   _Jv_InitField (0, clz, i);
 538                 }
 539             }
 540         }
 541
 542       // now we don't need the field_initializers anymore, so let the
 543       // collector get rid of it!
 544
 545       clz->field_initializers = 0;
 546     }
 547
 548   /************ PART TWO: VTABLE LAYOUT ***************/
 549
 550   /* preparation: build the vtable stubs (even interfaces can)
 551      have code -- for static constructors. */
 552   for (int i = 0; i < clz->method_count; i++)
 553     {
 554       _Jv_MethodBase *imeth = clz->interpreted_methods[i];
 555
 556       if ((clz->methods[i].accflags & Modifier::NATIVE) != 0)
 557         {
 558           // You might think we could use a virtual `ncode' method in
 559           // the _Jv_MethodBase and unify the native and non-native
 560           // cases.  Well, we can't, because we don't allocate these
 561           // objects using `new', and thus they don't get a vtable.
 562           _Jv_JNIMethod *jnim = reinterpret_cast<_Jv_JNIMethod *> (imeth);
 563           clz->methods[i].ncode = jnim->ncode ();
 564         }
 565       else if (imeth != 0)              // it could be abstract
 566         {
 567           _Jv_InterpMethod *im = reinterpret_cast<_Jv_InterpMethod *> (imeth);
 568           _Jv_VerifyMethod (im);
 569           clz->methods[i].ncode = im->ncode ();
 570         }
 571     }
 572
 573   if ((clz->accflags & Modifier::INTERFACE))
 574     {
 575       clz->state = JV_STATE_PREPARED;
 576       clz->notifyAll ();
 577       return;
 578     }
 579
 580   // A class might have so-called "Miranda methods".  This is a method
 581   // that is declared in an interface and not re-declared in an
 582   // abstract class.  Some compilers don't emit declarations for such
 583   // methods in the class; this will give us problems since we expect
 584   // a declaration for any method requiring a vtable entry.  We handle
 585   // this here by searching for such methods and constructing new
 586   // internal declarations for them.  We only need to do this for
 587   // abstract classes.
 588   if ((clz->accflags & Modifier::ABSTRACT))
 589     _Jv_PrepareMissingMethods (clz, clz);
 590
 591   clz->vtable_method_count = -1;
 592   _Jv_MakeVTable (clz);
 593
 594   /* wooha! we're done. */
 595   clz->state = JV_STATE_PREPARED;
 596   clz->notifyAll ();
 597 }
 598
 599 /** Do static initialization for fields with a constant initializer */
 600 void
 601 _Jv_InitField (jobject obj, jclass klass, int index)
 602 {
 603   using namespace java::lang::reflect;
 604
 605   if (obj != 0 && klass == 0)
 606     klass = obj->getClass ();
 607
 608   if (!_Jv_IsInterpretedClass (klass))
 609     return;
 610
 611   _Jv_InterpClass *clz = (_Jv_InterpClass*)klass;
 612
 613   _Jv_Field * field = (&clz->fields[0]) + index;
 614
 615   if (index > clz->field_count)
 616     throw_internal_error ("field out of range");
 617
 618   int init = clz->field_initializers[index];
 619   if (init == 0)
 620     return;
 621
 622   _Jv_Constants *pool = &clz->constants;
 623   int tag = pool->tags[init];
 624
 625   if (! field->isResolved ())
 626     throw_internal_error ("initializing unresolved field");
 627
 628   if (obj==0 && ((field->flags & Modifier::STATIC) == 0))
 629     throw_internal_error ("initializing non-static field with no object");
 630
 631   void *addr = 0;
 632
 633   if ((field->flags & Modifier::STATIC) != 0)
 634     addr = (void*) field->u.addr;
 635   else
 636     addr = (void*) (((char*)obj) + field->u.boffset);
 637
 638   switch (tag)
 639     {
 640     case JV_CONSTANT_String:
 641       {
 642         _Jv_MonitorEnter (clz);
 643         jstring str;
 644         str = _Jv_NewStringUtf8Const (pool->data[init].utf8);
 645         pool->data[init].string = str;
 646         pool->tags[init] = JV_CONSTANT_ResolvedString;
 647         _Jv_MonitorExit (clz);
 648       }
 649       /* fall through */
 650
 651     case JV_CONSTANT_ResolvedString:
 652       if (! (field->type == &StringClass
 653              || field->type == &java::lang::Class::class$))
 654         throw_class_format_error ("string initialiser to non-string field");
 655
 656       *(jstring*)addr = pool->data[init].string;
 657       break;
 658
 659     case JV_CONSTANT_Integer:
 660       {
 661         int value = pool->data[init].i;
 662
 663         if (field->type == JvPrimClass (boolean))
 664           *(jboolean*)addr = (jboolean)value;
 665
 666         else if (field->type == JvPrimClass (byte))
 667           *(jbyte*)addr = (jbyte)value;
 668
 669         else if (field->type == JvPrimClass (char))
 670           *(jchar*)addr = (jchar)value;
 671
 672         else if (field->type == JvPrimClass (short))
 673           *(jshort*)addr = (jshort)value;
 674
 675         else if (field->type == JvPrimClass (int))
 676           *(jint*)addr = (jint)value;
 677
 678         else
 679           throw_class_format_error ("erroneous field initializer");
 680       }
 681       break;
 682
 683     case JV_CONSTANT_Long:
 684       if (field->type != JvPrimClass (long))
 685         throw_class_format_error ("erroneous field initializer");
 686
 687       *(jlong*)addr = _Jv_loadLong (&pool->data[init]);
 688       break;
 689
 690     case JV_CONSTANT_Float:
 691       if (field->type != JvPrimClass (float))
 692         throw_class_format_error ("erroneous field initializer");
 693
 694       *(jfloat*)addr = pool->data[init].f;
 695       break;
 696
 697     case JV_CONSTANT_Double:
 698       if (field->type != JvPrimClass (double))
 699         throw_class_format_error ("erroneous field initializer");
 700
 701       *(jdouble*)addr = _Jv_loadDouble (&pool->data[init]);
 702       break;
 703
 704     default:
 705       throw_class_format_error ("erroneous field initializer");
 706     }
 707 }
 708
 709 static int
 710 get_alignment_from_class (jclass klass)
 711 {
 712   if (klass == JvPrimClass (byte))
 713     return  __alignof__ (jbyte);
 714   else if (klass == JvPrimClass (short))
 715     return  __alignof__ (jshort);
 716   else if (klass == JvPrimClass (int))
 717     return  __alignof__ (jint);
 718   else if (klass == JvPrimClass (long))
 719     return  __alignof__ (jlong);
 720   else if (klass == JvPrimClass (boolean))
 721     return  __alignof__ (jboolean);
 722   else if (klass == JvPrimClass (char))
 723     return  __alignof__ (jchar);
 724   else if (klass == JvPrimClass (float))
 725     return  __alignof__ (jfloat);
 726   else if (klass == JvPrimClass (double))
 727     return  __alignof__ (jdouble);
 728   else
 729     return __alignof__ (jobject);
 730 }
 731
 732
 733 inline static unsigned char*
 734 skip_one_type (unsigned char* ptr)
 735 {
 736   int ch = *ptr++;
 737
 738   while (ch == '[')
 739     {
 740       ch = *ptr++;
 741     }
 742
 743   if (ch == 'L')
 744     {
 745       do { ch = *ptr++; } while (ch != ';');
 746     }
 747
 748   return ptr;
 749 }
 750
 751 static ffi_type*
 752 get_ffi_type_from_signature (unsigned char* ptr)
 753 {
 754   switch (*ptr)
 755     {
 756     case 'L':
 757     case '[':
 758       return &ffi_type_pointer;
 759       break;
 760
 761     case 'Z':
 762       // On some platforms a bool is a byte, on others an int.
 763       if (sizeof (jboolean) == sizeof (jbyte))
 764         return &ffi_type_sint8;
 765       else
 766         {
 767           JvAssert (sizeof (jbyte) == sizeof (jint));
 768           return &ffi_type_sint32;
 769         }
 770       break;
 771
 772     case 'B':
 773       return &ffi_type_sint8;
 774       break;
 775
 776     case 'C':
 777       return &ffi_type_uint16;
 778       break;
 779
 780     case 'S':
 781       return &ffi_type_sint16;
 782       break;
 783
 784     case 'I':
 785       return &ffi_type_sint32;
 786       break;
 787
 788     case 'J':
 789       return &ffi_type_sint64;
 790       break;
 791
 792     case 'F':
 793       return &ffi_type_float;
 794       break;
 795
 796     case 'D':
 797       return &ffi_type_double;
 798       break;
 799
 800     case 'V':
 801       return &ffi_type_void;
 802       break;
 803     }
 804
 805   throw_internal_error ("unknown type in signature");
 806 }
 807
 808 /* this function yields the number of actual arguments, that is, if the
 809  * function is non-static, then one is added to the number of elements
 810  * found in the signature */
 811
 812 int
 813 _Jv_count_arguments (_Jv_Utf8Const *signature,
 814                      jboolean staticp)
 815 {
 816   unsigned char *ptr = (unsigned char*) signature->data;
 817   int arg_count = staticp ? 0 : 1;
 818
 819   /* first, count number of arguments */
 820
 821   // skip '('
 822   ptr++;
 823
 824   // count args
 825   while (*ptr != ')')
 826     {
 827       ptr = skip_one_type (ptr);
 828       arg_count += 1;
 829     }
 830
 831   return arg_count;
 832 }
 833
 834 /* This beast will build a cif, given the signature.  Memory for
 835  * the cif itself and for the argument types must be allocated by the
 836  * caller.
 837  */
 838
 839 static int
 840 init_cif (_Jv_Utf8Const* signature,
 841           int arg_count,
 842           jboolean staticp,
 843           ffi_cif *cif,
 844           ffi_type **arg_types,
 845           ffi_type **rtype_p)
 846 {
 847   unsigned char *ptr = (unsigned char*) signature->data;
 848
 849   int arg_index = 0;            // arg number
 850   int item_count = 0;           // stack-item count
 851
 852   // setup receiver
 853   if (!staticp)
 854     {
 855       arg_types[arg_index++] = &ffi_type_pointer;
 856       item_count += 1;
 857     }
 858
 859   // skip '('
 860   ptr++;
 861
 862   // assign arg types
 863   while (*ptr != ')')
 864     {
 865       arg_types[arg_index++] = get_ffi_type_from_signature (ptr);
 866
 867       if (*ptr == 'J' || *ptr == 'D')
 868         item_count += 2;
 869       else
 870         item_count += 1;
 871
 872       ptr = skip_one_type (ptr);
 873     }
 874
 875   // skip ')'
 876   ptr++;
 877   ffi_type *rtype = get_ffi_type_from_signature (ptr);
 878
 879   ptr = skip_one_type (ptr);
 880   if (ptr != (unsigned char*)signature->data + signature->length)
 881     throw_internal_error ("did not find end of signature");
 882
 883   if (ffi_prep_cif (cif, FFI_DEFAULT_ABI,
 884                     arg_count, rtype, arg_types) != FFI_OK)
 885     throw_internal_error ("ffi_prep_cif failed");
 886
 887   if (rtype_p != NULL)
 888     *rtype_p = rtype;
 889
 890   return item_count;
 891 }
 892
 893 #if FFI_NATIVE_RAW_API
 894 #   define FFI_PREP_RAW_CLOSURE ffi_prep_raw_closure
 895 #   define FFI_RAW_SIZE ffi_raw_size
 896 #else
 897 #   define FFI_PREP_RAW_CLOSURE ffi_prep_java_raw_closure
 898 #   define FFI_RAW_SIZE ffi_java_raw_size
 899 #endif
 900
 901 /* we put this one here, and not in interpret.cc because it
 902  * calls the utility routines _Jv_count_arguments
 903  * which are static to this module.  The following struct defines the
 904  * layout we use for the stubs, it's only used in the ncode method. */
 905
 906 typedef struct {
 907   ffi_raw_closure  closure;
 908   ffi_cif   cif;
 909   ffi_type *arg_types[0];
 910 } ncode_closure;
 911
 912 typedef void (*ffi_closure_fun) (ffi_cif*,void*,ffi_raw*,void*);
 913
 914 void *
 915 _Jv_InterpMethod::ncode ()
 916 {
 917   using namespace java::lang::reflect;
 918
 919   if (self->ncode != 0)
 920     return self->ncode;
 921
 922   jboolean staticp = (self->accflags & Modifier::STATIC) != 0;
 923   int arg_count = _Jv_count_arguments (self->signature, staticp);
 924
 925   ncode_closure *closure =
 926     (ncode_closure*)_Jv_AllocBytes (sizeof (ncode_closure)
 927                                         + arg_count * sizeof (ffi_type*));
 928
 929   init_cif (self->signature,
 930             arg_count,
 931             staticp,
 932             &closure->cif,
 933             &closure->arg_types[0],
 934             NULL);
 935
 936   ffi_closure_fun fun;
 937
 938   args_raw_size = FFI_RAW_SIZE (&closure->cif);
 939
 940   JvAssert ((self->accflags & Modifier::NATIVE) == 0);
 941
 942   if ((self->accflags & Modifier::SYNCHRONIZED) != 0)
 943     {
 944       if (staticp)
 945         fun = (ffi_closure_fun)&_Jv_InterpMethod::run_synch_class;
 946       else
 947         fun = (ffi_closure_fun)&_Jv_InterpMethod::run_synch_object;
 948     }
 949   else
 950     {
 951       if (staticp)
 952         fun = (ffi_closure_fun)&_Jv_InterpMethod::run_class;
 953       else
 954         fun = (ffi_closure_fun)&_Jv_InterpMethod::run_normal;
 955     }
 956
 957   FFI_PREP_RAW_CLOSURE (&closure->closure,
 958                         &closure->cif,
 959                         fun,
 960                         (void*)this);
 961
 962   self->ncode = (void*)closure;
 963   return self->ncode;
 964 }
 965
 966 void *
 967 _Jv_JNIMethod::ncode ()
 968 {
 969   using namespace java::lang::reflect;
 970
 971   if (self->ncode != 0)
 972     return self->ncode;
 973
 974   jboolean staticp = (self->accflags & Modifier::STATIC) != 0;
 975   int arg_count = _Jv_count_arguments (self->signature, staticp);
 976
 977   ncode_closure *closure =
 978     (ncode_closure*)_Jv_AllocBytes (sizeof (ncode_closure)
 979                                     + arg_count * sizeof (ffi_type*));
 980
 981   ffi_type *rtype;
 982   init_cif (self->signature,
 983             arg_count,
 984             staticp,
 985             &closure->cif,
 986             &closure->arg_types[0],
 987             &rtype);
 988
 989   ffi_closure_fun fun;
 990
 991   args_raw_size = FFI_RAW_SIZE (&closure->cif);
 992
 993   // Initialize the argument types and CIF that represent the actual
 994   // underlying JNI function.
 995   int extra_args = 1;
 996   if ((self->accflags & Modifier::STATIC))
 997     ++extra_args;
 998   jni_arg_types = (ffi_type **) _Jv_Malloc ((extra_args + arg_count)
 999                                             * sizeof (ffi_type *));
1000   int offset = 0;
1001   jni_arg_types[offset++] = &ffi_type_pointer;
1002   if ((self->accflags & Modifier::STATIC))
1003     jni_arg_types[offset++] = &ffi_type_pointer;
1004   memcpy (&jni_arg_types[offset], &closure->arg_types[0],
1005           arg_count * sizeof (ffi_type *));
1006
1007   if (ffi_prep_cif (&jni_cif, _Jv_platform_ffi_abi,
1008                     extra_args + arg_count, rtype,
1009                     jni_arg_types) != FFI_OK)
1010     throw_internal_error ("ffi_prep_cif failed for JNI function");
1011
1012   JvAssert ((self->accflags & Modifier::NATIVE) != 0);
1013
1014   // FIXME: for now we assume that all native methods for
1015   // interpreted code use JNI.
1016   fun = (ffi_closure_fun) &_Jv_JNIMethod::call;
1017
1018   FFI_PREP_RAW_CLOSURE (&closure->closure,
1019                         &closure->cif,
1020                         fun,
1021                         (void*) this);
1022
1023   self->ncode = (void *) closure;
1024   return self->ncode;
1025 }
1026
1027
1028 /* A _Jv_ResolvedMethod is what is put in the constant pool for a
1029  * MethodRef or InterfacemethodRef.  */
1030 static _Jv_ResolvedMethod*
1031 _Jv_BuildResolvedMethod (_Jv_Method* method,
1032                          jclass      klass,
1033                          jboolean staticp,
1034                          jint vtable_index)
1035 {
1036   int arg_count = _Jv_count_arguments (method->signature, staticp);
1037
1038   _Jv_ResolvedMethod* result = (_Jv_ResolvedMethod*)
1039     _Jv_AllocBytes (sizeof (_Jv_ResolvedMethod)
1040                     + arg_count*sizeof (ffi_type*));
1041
1042   result->stack_item_count
1043     = init_cif (method->signature,
1044                 arg_count,
1045                 staticp,
1046                 &result->cif,
1047                 &result->arg_types[0],
1048                 NULL);
1049
1050   result->vtable_index        = vtable_index;
1051   result->method              = method;
1052   result->klass               = klass;
1053
1054   return result;
1055 }
1056
1057
1058 static void
1059 throw_class_format_error (jstring msg)
1060 {
1061   throw (msg
1062          ? new java::lang::ClassFormatError (msg)
1063          : new java::lang::ClassFormatError);
1064 }
1065
1066 static void
1067 throw_class_format_error (char *msg)
1068 {
1069   throw_class_format_error (JvNewStringLatin1 (msg));
1070 }
1071
1072 static void
1073 throw_internal_error (char *msg)
1074 {
1075   throw new java::lang::InternalError (JvNewStringLatin1 (msg));
1076 }
1077
1078
1079 #endif /* INTERPRETER */