libjava/prims.cc

   1 // prims.cc - Code for core of runtime environment.
   2
   3 /* Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005  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 #include <config.h>
  12 #include <platform.h>
  13
  14 #include <stdlib.h>
  15 #include <stdarg.h>
  16 #include <stdio.h>
  17 #include <string.h>
  18 #include <signal.h>
  19
  20 #ifdef HAVE_UNISTD_H
  21 #include <unistd.h>
  22 #endif
  23
  24 #include <gcj/cni.h>
  25 #include <jvm.h>
  26 #include <java-signal.h>
  27 #include <java-threads.h>
  28 #include <java-interp.h>
  29
  30 #ifdef ENABLE_JVMPI
  31 #include <jvmpi.h>
  32 #include <java/lang/ThreadGroup.h>
  33 #endif
  34
  35 #ifndef DISABLE_GETENV_PROPERTIES
  36 #include <ctype.h>
  37 #include <java-props.h>
  38 #define PROCESS_GCJ_PROPERTIES process_gcj_properties()
  39 #else
  40 #define PROCESS_GCJ_PROPERTIES
  41 #endif // DISABLE_GETENV_PROPERTIES
  42
  43 #include <java/lang/Class.h>
  44 #include <java/lang/ClassLoader.h>
  45 #include <java/lang/Runtime.h>
  46 #include <java/lang/String.h>
  47 #include <java/lang/Thread.h>
  48 #include <java/lang/ThreadGroup.h>
  49 #include <java/lang/ArrayIndexOutOfBoundsException.h>
  50 #include <java/lang/ArithmeticException.h>
  51 #include <java/lang/ClassFormatError.h>
  52 #include <java/lang/InternalError.h>
  53 #include <java/lang/NegativeArraySizeException.h>
  54 #include <java/lang/NullPointerException.h>
  55 #include <java/lang/OutOfMemoryError.h>
  56 #include <java/lang/System.h>
  57 #include <java/lang/VMThrowable.h>
  58 #include <java/lang/reflect/Modifier.h>
  59 #include <java/io/PrintStream.h>
  60 #include <java/lang/UnsatisfiedLinkError.h>
  61 #include <java/lang/VirtualMachineError.h>
  62 #include <gnu/gcj/runtime/ExtensionClassLoader.h>
  63 #include <gnu/gcj/runtime/FinalizerThread.h>
  64 #include <execution.h>
  65 #include <gnu/java/lang/MainThread.h>
  66 #include <java/lang/VMClassLoader.h>
  67
  68 #ifdef USE_LTDL
  69 #include <ltdl.h>
  70 #endif
  71
  72 // Execution engine for compiled code.
  73 _Jv_CompiledEngine _Jv_soleCompiledEngine;
  74
  75 // We allocate a single OutOfMemoryError exception which we keep
  76 // around for use if we run out of memory.
  77 static java::lang::OutOfMemoryError *no_memory;
  78
  79 // Number of bytes in largest array object we create.  This could be
  80 // increased to the largest size_t value, so long as the appropriate
  81 // functions are changed to take a size_t argument instead of jint.
  82 #define MAX_OBJECT_SIZE ((1<<31) - 1)
  83
  84 // Properties set at compile time.
  85 const char **_Jv_Compiler_Properties = NULL;
  86 int _Jv_Properties_Count = 0;
  87
  88 #ifndef DISABLE_GETENV_PROPERTIES
  89 // Property key/value pairs.
  90 property_pair *_Jv_Environment_Properties;
  91 #endif
  92
  93 // Stash the argv pointer to benefit native libraries that need it.
  94 const char **_Jv_argv;
  95 int _Jv_argc;
  96
  97 // Argument support.
  98 int
  99 _Jv_GetNbArgs (void)
 100 {
 101   // _Jv_argc is 0 if not explicitly initialized.
 102   return _Jv_argc;
 103 }
 104
 105 const char *
 106 _Jv_GetSafeArg (int index)
 107 {
 108   if (index >=0 && index < _Jv_GetNbArgs ())
 109     return _Jv_argv[index];
 110   else
 111     return "";
 112 }
 113
 114 void
 115 _Jv_SetArgs (int argc, const char **argv)
 116 {
 117   _Jv_argc = argc;
 118   _Jv_argv = argv;
 119 }
 120
 121 #ifdef ENABLE_JVMPI
 122 // Pointer to JVMPI notification functions.
 123 void (*_Jv_JVMPI_Notify_OBJECT_ALLOC) (JVMPI_Event *event);
 124 void (*_Jv_JVMPI_Notify_THREAD_START) (JVMPI_Event *event);
 125 void (*_Jv_JVMPI_Notify_THREAD_END) (JVMPI_Event *event);
 126 #endif
 127 \f
 128
 129 #if defined (HANDLE_SEGV) || defined(HANDLE_FPE)
 130 /* Unblock a signal.  Unless we do this, the signal may only be sent
 131    once.  */
 132 static void
 133 unblock_signal (int signum __attribute__ ((__unused__)))
 134 {
 135 #ifdef _POSIX_VERSION
 136   sigset_t sigs;
 137
 138   sigemptyset (&sigs);
 139   sigaddset (&sigs, signum);
 140   sigprocmask (SIG_UNBLOCK, &sigs, NULL);
 141 #endif
 142 }
 143 #endif
 144
 145 #ifdef HANDLE_SEGV
 146 SIGNAL_HANDLER (catch_segv)
 147 {
 148   java::lang::NullPointerException *nullp
 149     = new java::lang::NullPointerException;
 150   unblock_signal (SIGSEGV);
 151   MAKE_THROW_FRAME (nullp);
 152   throw nullp;
 153 }
 154 #endif
 155
 156 #ifdef HANDLE_FPE
 157 SIGNAL_HANDLER (catch_fpe)
 158 {
 159   java::lang::ArithmeticException *arithexception
 160     = new java::lang::ArithmeticException (JvNewStringLatin1 ("/ by zero"));
 161   unblock_signal (SIGFPE);
 162 #ifdef HANDLE_DIVIDE_OVERFLOW
 163   HANDLE_DIVIDE_OVERFLOW;
 164 #else
 165   MAKE_THROW_FRAME (arithexception);
 166 #endif
 167   throw arithexception;
 168 }
 169 #endif
 170
 171 \f
 172
 173 jboolean
 174 _Jv_equalUtf8Consts (const Utf8Const* a, const Utf8Const *b)
 175 {
 176   int len;
 177   const _Jv_ushort *aptr, *bptr;
 178   if (a == b)
 179     return true;
 180   if (a->hash != b->hash)
 181     return false;
 182   len = a->length;
 183   if (b->length != len)
 184     return false;
 185   aptr = (const _Jv_ushort *)a->data;
 186   bptr = (const _Jv_ushort *)b->data;
 187   len = (len + 1) >> 1;
 188   while (--len >= 0)
 189     if (*aptr++ != *bptr++)
 190       return false;
 191   return true;
 192 }
 193
 194 /* True iff A is equal to STR.
 195    HASH is STR->hashCode().
 196 */
 197
 198 jboolean
 199 _Jv_equal (Utf8Const* a, jstring str, jint hash)
 200 {
 201   if (a->hash != (_Jv_ushort) hash)
 202     return false;
 203   jint len = str->length();
 204   jint i = 0;
 205   jchar *sptr = _Jv_GetStringChars (str);
 206   unsigned char* ptr = (unsigned char*) a->data;
 207   unsigned char* limit = ptr + a->length;
 208   for (;; i++, sptr++)
 209     {
 210       int ch = UTF8_GET (ptr, limit);
 211       if (i == len)
 212         return ch < 0;
 213       if (ch != *sptr)
 214         return false;
 215     }
 216   return true;
 217 }
 218
 219 /* Like _Jv_equal, but stop after N characters.  */
 220 jboolean
 221 _Jv_equaln (Utf8Const *a, jstring str, jint n)
 222 {
 223   jint len = str->length();
 224   jint i = 0;
 225   jchar *sptr = _Jv_GetStringChars (str);
 226   unsigned char* ptr = (unsigned char*) a->data;
 227   unsigned char* limit = ptr + a->length;
 228   for (; n-- > 0; i++, sptr++)
 229     {
 230       int ch = UTF8_GET (ptr, limit);
 231       if (i == len)
 232         return ch < 0;
 233       if (ch != *sptr)
 234         return false;
 235     }
 236   return true;
 237 }
 238
 239 /* Count the number of Unicode chars encoded in a given Ut8 string. */
 240 int
 241 _Jv_strLengthUtf8(char* str, int len)
 242 {
 243   unsigned char* ptr;
 244   unsigned char* limit;
 245   int str_length;
 246
 247   ptr = (unsigned char*) str;
 248   limit = ptr + len;
 249   str_length = 0;
 250   for (; ptr < limit; str_length++)
 251     {
 252       if (UTF8_GET (ptr, limit) < 0)
 253         return (-1);
 254     }
 255   return (str_length);
 256 }
 257
 258 /* Calculate a hash value for a string encoded in Utf8 format.
 259  * This returns the same hash value as specified or java.lang.String.hashCode.
 260  */
 261 jint
 262 _Jv_hashUtf8String (char* str, int len)
 263 {
 264   unsigned char* ptr = (unsigned char*) str;
 265   unsigned char* limit = ptr + len;
 266   jint hash = 0;
 267
 268   for (; ptr < limit;)
 269     {
 270       int ch = UTF8_GET (ptr, limit);
 271       /* Updated specification from
 272          http://www.javasoft.com/docs/books/jls/clarify.html. */
 273       hash = (31 * hash) + ch;
 274     }
 275   return hash;
 276 }
 277
 278 void
 279 _Jv_Utf8Const::init(char *s, int len)
 280 {
 281   ::memcpy (data, s, len);
 282   data[len] = 0;
 283   length = len;
 284   hash = _Jv_hashUtf8String (s, len) & 0xFFFF;
 285 }
 286
 287 _Jv_Utf8Const *
 288 _Jv_makeUtf8Const (char* s, int len)
 289 {
 290   if (len < 0)
 291     len = strlen (s);
 292   Utf8Const* m
 293     = (Utf8Const*) _Jv_AllocBytes (_Jv_Utf8Const::space_needed(s, len));
 294   m->init(s, len);
 295   return m;
 296 }
 297
 298 _Jv_Utf8Const *
 299 _Jv_makeUtf8Const (jstring string)
 300 {
 301   jint hash = string->hashCode ();
 302   jint len = _Jv_GetStringUTFLength (string);
 303
 304   Utf8Const* m = (Utf8Const*)
 305     _Jv_AllocBytes (sizeof(Utf8Const) + len + 1);
 306
 307   m->hash = hash;
 308   m->length = len;
 309
 310   _Jv_GetStringUTFRegion (string, 0, string->length (), m->data);
 311   m->data[len] = 0;
 312
 313   return m;
 314 }
 315
 316 \f
 317
 318 #ifdef DEBUG
 319 void
 320 _Jv_Abort (const char *function, const char *file, int line,
 321            const char *message)
 322 #else
 323 void
 324 _Jv_Abort (const char *, const char *, int, const char *message)
 325 #endif
 326 {
 327 #ifdef DEBUG
 328   fprintf (stderr,
 329            "libgcj failure: %s\n   in function %s, file %s, line %d\n",
 330            message, function, file, line);
 331 #else
 332   fprintf (stderr, "libgcj failure: %s\n", message);
 333 #endif
 334   abort ();
 335 }
 336
 337 static void
 338 fail_on_finalization (jobject)
 339 {
 340   JvFail ("object was finalized");
 341 }
 342
 343 void
 344 _Jv_GCWatch (jobject obj)
 345 {
 346   _Jv_RegisterFinalizer (obj, fail_on_finalization);
 347 }
 348
 349 void
 350 _Jv_ThrowBadArrayIndex(jint bad_index)
 351 {
 352   throw new java::lang::ArrayIndexOutOfBoundsException
 353     (java::lang::String::valueOf (bad_index));
 354 }
 355
 356 void
 357 _Jv_ThrowNullPointerException ()
 358 {
 359   throw new java::lang::NullPointerException;
 360 }
 361
 362 // Resolve an entry in the constant pool and return the target
 363 // address.
 364 void *
 365 _Jv_ResolvePoolEntry (jclass this_class, jint index)
 366 {
 367   _Jv_Constants *pool = &this_class->constants;
 368
 369   if ((pool->tags[index] & JV_CONSTANT_ResolvedFlag) != 0)
 370     return pool->data[index].field->u.addr;
 371
 372   JvSynchronize sync (this_class);
 373   return (_Jv_Linker::resolve_pool_entry (this_class, index))
 374     .field->u.addr;
 375 }
 376
 377
 378 // Explicitly throw a no memory exception.
 379 // The collector calls this when it encounters an out-of-memory condition.
 380 void _Jv_ThrowNoMemory()
 381 {
 382   throw no_memory;
 383 }
 384
 385 #ifdef ENABLE_JVMPI
 386 # define JVMPI_NOTIFY_ALLOC(klass,size,obj) \
 387     if (__builtin_expect (_Jv_JVMPI_Notify_OBJECT_ALLOC != 0, false)) \
 388       jvmpi_notify_alloc(klass,size,obj);
 389 static void
 390 jvmpi_notify_alloc(jclass klass, jint size, jobject obj)
 391 {
 392   // Service JVMPI allocation request.
 393   JVMPI_Event event;
 394
 395   event.event_type = JVMPI_EVENT_OBJECT_ALLOC;
 396   event.env_id = NULL;
 397   event.u.obj_alloc.arena_id = 0;
 398   event.u.obj_alloc.class_id = (jobjectID) klass;
 399   event.u.obj_alloc.is_array = 0;
 400   event.u.obj_alloc.size = size;
 401   event.u.obj_alloc.obj_id = (jobjectID) obj;
 402
 403   // FIXME:  This doesn't look right for the Boehm GC.  A GC may
 404   // already be in progress.  _Jv_DisableGC () doesn't wait for it.
 405   // More importantly, I don't see the need for disabling GC, since we
 406   // blatantly have a pointer to obj on our stack, ensuring that the
 407   // object can't be collected.  Even for a nonconservative collector,
 408   // it appears to me that this must be true, since we are about to
 409   // return obj. Isn't this whole approach way too intrusive for
 410   // a useful profiling interface?                      - HB
 411   _Jv_DisableGC ();
 412   (*_Jv_JVMPI_Notify_OBJECT_ALLOC) (&event);
 413   _Jv_EnableGC ();
 414 }
 415 #else /* !ENABLE_JVMPI */
 416 # define JVMPI_NOTIFY_ALLOC(klass,size,obj) /* do nothing */
 417 #endif
 418
 419 // Allocate a new object of class KLASS.
 420 // First a version that assumes that we have no finalizer, and that
 421 // the class is already initialized.
 422 // If we know that JVMPI is disabled, this can be replaced by a direct call
 423 // to the allocator for the appropriate GC.
 424 jobject
 425 _Jv_AllocObjectNoInitNoFinalizer (jclass klass)
 426 {
 427   jint size = klass->size ();
 428   jobject obj = (jobject) _Jv_AllocObj (size, klass);
 429   JVMPI_NOTIFY_ALLOC (klass, size, obj);
 430   return obj;
 431 }
 432
 433 // And now a version that initializes if necessary.
 434 jobject
 435 _Jv_AllocObjectNoFinalizer (jclass klass)
 436 {
 437   _Jv_InitClass (klass);
 438   jint size = klass->size ();
 439   jobject obj = (jobject) _Jv_AllocObj (size, klass);
 440   JVMPI_NOTIFY_ALLOC (klass, size, obj);
 441   return obj;
 442 }
 443
 444 // And now the general version that registers a finalizer if necessary.
 445 jobject
 446 _Jv_AllocObject (jclass klass)
 447 {
 448   jobject obj = _Jv_AllocObjectNoFinalizer (klass);
 449
 450   // We assume that the compiler only generates calls to this routine
 451   // if there really is an interesting finalizer.
 452   // Unfortunately, we still have to the dynamic test, since there may
 453   // be cni calls to this routine.
 454   // Note that on IA64 get_finalizer() returns the starting address of the
 455   // function, not a function pointer.  Thus this still works.
 456   if (klass->vtable->get_finalizer ()
 457       != java::lang::Object::class$.vtable->get_finalizer ())
 458     _Jv_RegisterFinalizer (obj, _Jv_FinalizeObject);
 459   return obj;
 460 }
 461
 462 // Allocate a String, including variable length storage.
 463 jstring
 464 _Jv_AllocString(jsize len)
 465 {
 466   using namespace java::lang;
 467
 468   jsize sz = sizeof(java::lang::String) + len * sizeof(jchar);
 469
 470   // We assert that for strings allocated this way, the data field
 471   // will always point to the object itself.  Thus there is no reason
 472   // for the garbage collector to scan any of it.
 473   // Furthermore, we're about to overwrite the string data, so
 474   // initialization of the object is not an issue.
 475
 476   // String needs no initialization, and there is no finalizer, so
 477   // we can go directly to the collector's allocator interface.
 478   jstring obj = (jstring) _Jv_AllocPtrFreeObj(sz, &String::class$);
 479
 480   obj->data = obj;
 481   obj->boffset = sizeof(java::lang::String);
 482   obj->count = len;
 483   obj->cachedHashCode = 0;
 484
 485   JVMPI_NOTIFY_ALLOC (&String::class$, sz, obj);
 486
 487   return obj;
 488 }
 489
 490 // A version of the above that assumes the object contains no pointers,
 491 // and requires no finalization.  This can't happen if we need pointers
 492 // to locks.
 493 #ifdef JV_HASH_SYNCHRONIZATION
 494 jobject
 495 _Jv_AllocPtrFreeObject (jclass klass)
 496 {
 497   _Jv_InitClass (klass);
 498   jint size = klass->size ();
 499
 500   jobject obj = (jobject) _Jv_AllocPtrFreeObj (size, klass);
 501
 502   JVMPI_NOTIFY_ALLOC (klass, size, obj);
 503
 504   return obj;
 505 }
 506 #endif /* JV_HASH_SYNCHRONIZATION */
 507
 508
 509 // Allocate a new array of Java objects.  Each object is of type
 510 // `elementClass'.  `init' is used to initialize each slot in the
 511 // array.
 512 jobjectArray
 513 _Jv_NewObjectArray (jsize count, jclass elementClass, jobject init)
 514 {
 515   if (__builtin_expect (count < 0, false))
 516     throw new java::lang::NegativeArraySizeException;
 517
 518   JvAssert (! elementClass->isPrimitive ());
 519
 520   // Ensure that elements pointer is properly aligned.
 521   jobjectArray obj = NULL;
 522   size_t size = (size_t) elements (obj);
 523   // Check for overflow.
 524   if (__builtin_expect ((size_t) count >
 525                         (MAX_OBJECT_SIZE - 1 - size) / sizeof (jobject), false))
 526     throw no_memory;
 527
 528   size += count * sizeof (jobject);
 529
 530   jclass klass = _Jv_GetArrayClass (elementClass,
 531                                     elementClass->getClassLoaderInternal());
 532
 533   obj = (jobjectArray) _Jv_AllocArray (size, klass);
 534   // Cast away const.
 535   jsize *lp = const_cast<jsize *> (&obj->length);
 536   *lp = count;
 537   // We know the allocator returns zeroed memory.  So don't bother
 538   // zeroing it again.
 539   if (init)
 540     {
 541       jobject *ptr = elements(obj);
 542       while (--count >= 0)
 543         *ptr++ = init;
 544     }
 545   return obj;
 546 }
 547
 548 // Allocate a new array of primitives.  ELTYPE is the type of the
 549 // element, COUNT is the size of the array.
 550 jobject
 551 _Jv_NewPrimArray (jclass eltype, jint count)
 552 {
 553   int elsize = eltype->size();
 554   if (__builtin_expect (count < 0, false))
 555     throw new java::lang::NegativeArraySizeException;
 556
 557   JvAssert (eltype->isPrimitive ());
 558   jobject dummy = NULL;
 559   size_t size = (size_t) _Jv_GetArrayElementFromElementType (dummy, eltype);
 560
 561   // Check for overflow.
 562   if (__builtin_expect ((size_t) count >
 563                         (MAX_OBJECT_SIZE - size) / elsize, false))
 564     throw no_memory;
 565
 566   jclass klass = _Jv_GetArrayClass (eltype, 0);
 567
 568 # ifdef JV_HASH_SYNCHRONIZATION
 569   // Since the vtable is always statically allocated,
 570   // these are completely pointerfree!  Make sure the GC doesn't touch them.
 571   __JArray *arr =
 572     (__JArray*) _Jv_AllocPtrFreeObj (size + elsize * count, klass);
 573   memset((char *)arr + size, 0, elsize * count);
 574 # else
 575   __JArray *arr = (__JArray*) _Jv_AllocObj (size + elsize * count, klass);
 576   // Note that we assume we are given zeroed memory by the allocator.
 577 # endif
 578   // Cast away const.
 579   jsize *lp = const_cast<jsize *> (&arr->length);
 580   *lp = count;
 581
 582   return arr;
 583 }
 584
 585 jobject
 586 _Jv_NewArray (jint type, jint size)
 587 {
 588   switch (type)
 589     {
 590       case  4:  return JvNewBooleanArray (size);
 591       case  5:  return JvNewCharArray (size);
 592       case  6:  return JvNewFloatArray (size);
 593       case  7:  return JvNewDoubleArray (size);
 594       case  8:  return JvNewByteArray (size);
 595       case  9:  return JvNewShortArray (size);
 596       case 10:  return JvNewIntArray (size);
 597       case 11:  return JvNewLongArray (size);
 598     }
 599   throw new java::lang::InternalError
 600     (JvNewStringLatin1 ("invalid type code in _Jv_NewArray"));
 601 }
 602
 603 // Allocate a possibly multi-dimensional array but don't check that
 604 // any array length is <0.
 605 static jobject
 606 _Jv_NewMultiArrayUnchecked (jclass type, jint dimensions, jint *sizes)
 607 {
 608   JvAssert (type->isArray());
 609   jclass element_type = type->getComponentType();
 610   jobject result;
 611   if (element_type->isPrimitive())
 612     result = _Jv_NewPrimArray (element_type, sizes[0]);
 613   else
 614     result = _Jv_NewObjectArray (sizes[0], element_type, NULL);
 615
 616   if (dimensions > 1)
 617     {
 618       JvAssert (! element_type->isPrimitive());
 619       JvAssert (element_type->isArray());
 620       jobject *contents = elements ((jobjectArray) result);
 621       for (int i = 0; i < sizes[0]; ++i)
 622         contents[i] = _Jv_NewMultiArrayUnchecked (element_type, dimensions - 1,
 623                                                   sizes + 1);
 624     }
 625
 626   return result;
 627 }
 628
 629 jobject
 630 _Jv_NewMultiArray (jclass type, jint dimensions, jint *sizes)
 631 {
 632   for (int i = 0; i < dimensions; ++i)
 633     if (sizes[i] < 0)
 634       throw new java::lang::NegativeArraySizeException;
 635
 636   return _Jv_NewMultiArrayUnchecked (type, dimensions, sizes);
 637 }
 638
 639 jobject
 640 _Jv_NewMultiArray (jclass array_type, jint dimensions, ...)
 641 {
 642   va_list args;
 643   jint sizes[dimensions];
 644   va_start (args, dimensions);
 645   for (int i = 0; i < dimensions; ++i)
 646     {
 647       jint size = va_arg (args, jint);
 648       if (size < 0)
 649         throw new java::lang::NegativeArraySizeException;
 650       sizes[i] = size;
 651     }
 652   va_end (args);
 653
 654   return _Jv_NewMultiArrayUnchecked (array_type, dimensions, sizes);
 655 }
 656
 657 \f
 658
 659 // Ensure 8-byte alignment, for hash synchronization.
 660 #define DECLARE_PRIM_TYPE(NAME)                 \
 661   java::lang::Class _Jv_##NAME##Class __attribute__ ((aligned (8)));
 662
 663 DECLARE_PRIM_TYPE(byte)
 664 DECLARE_PRIM_TYPE(short)
 665 DECLARE_PRIM_TYPE(int)
 666 DECLARE_PRIM_TYPE(long)
 667 DECLARE_PRIM_TYPE(boolean)
 668 DECLARE_PRIM_TYPE(char)
 669 DECLARE_PRIM_TYPE(float)
 670 DECLARE_PRIM_TYPE(double)
 671 DECLARE_PRIM_TYPE(void)
 672
 673 void
 674 _Jv_InitPrimClass (jclass cl, char *cname, char sig, int len)
 675 {
 676   using namespace java::lang::reflect;
 677
 678   // We must set the vtable for the class; the Java constructor
 679   // doesn't do this.
 680   (*(_Jv_VTable **) cl) = java::lang::Class::class$.vtable;
 681
 682   // Initialize the fields we care about.  We do this in the same
 683   // order they are declared in Class.h.
 684   cl->name = _Jv_makeUtf8Const ((char *) cname, -1);
 685   cl->accflags = Modifier::PUBLIC | Modifier::FINAL | Modifier::ABSTRACT;
 686   cl->method_count = sig;
 687   cl->size_in_bytes = len;
 688   cl->vtable = JV_PRIMITIVE_VTABLE;
 689   cl->state = JV_STATE_DONE;
 690   cl->depth = -1;
 691 }
 692
 693 jclass
 694 _Jv_FindClassFromSignature (char *sig, java::lang::ClassLoader *loader)
 695 {
 696   switch (*sig)
 697     {
 698     case 'B':
 699       return JvPrimClass (byte);
 700     case 'S':
 701       return JvPrimClass (short);
 702     case 'I':
 703       return JvPrimClass (int);
 704     case 'J':
 705       return JvPrimClass (long);
 706     case 'Z':
 707       return JvPrimClass (boolean);
 708     case 'C':
 709       return JvPrimClass (char);
 710     case 'F':
 711       return JvPrimClass (float);
 712     case 'D':
 713       return JvPrimClass (double);
 714     case 'V':
 715       return JvPrimClass (void);
 716     case 'L':
 717       {
 718         int i;
 719         for (i = 1; sig[i] && sig[i] != ';'; ++i)
 720           ;
 721         _Jv_Utf8Const *name = _Jv_makeUtf8Const (&sig[1], i - 1);
 722         return _Jv_FindClass (name, loader);
 723       }
 724     case '[':
 725       {
 726         jclass klass = _Jv_FindClassFromSignature (&sig[1], loader);
 727         if (! klass)
 728           return NULL;
 729         return _Jv_GetArrayClass (klass, loader);
 730       }
 731     }
 732
 733   return NULL;                  // Placate compiler.
 734 }
 735
 736 \f
 737
 738 JArray<jstring> *
 739 JvConvertArgv (int argc, const char **argv)
 740 {
 741   if (argc < 0)
 742     argc = 0;
 743   jobjectArray ar = JvNewObjectArray(argc, &java::lang::String::class$, NULL);
 744   jobject *ptr = elements(ar);
 745   jbyteArray bytes = NULL;
 746   for (int i = 0;  i < argc;  i++)
 747     {
 748       const char *arg = argv[i];
 749       int len = strlen (arg);
 750       if (bytes == NULL || bytes->length < len)
 751         bytes = JvNewByteArray (len);
 752       jbyte *bytePtr = elements (bytes);
 753       // We assume jbyte == char.
 754       memcpy (bytePtr, arg, len);
 755
 756       // Now convert using the default encoding.
 757       *ptr++ = new java::lang::String (bytes, 0, len);
 758     }
 759   return (JArray<jstring>*) ar;
 760 }
 761
 762 // FIXME: These variables are static so that they will be
 763 // automatically scanned by the Boehm collector.  This is needed
 764 // because with qthreads the collector won't scan the initial stack --
 765 // it will only scan the qthreads stacks.
 766
 767 // Command line arguments.
 768 static JArray<jstring> *arg_vec;
 769
 770 // The primary thread.
 771 static java::lang::Thread *main_thread;
 772
 773 #ifndef DISABLE_GETENV_PROPERTIES
 774
 775 static char *
 776 next_property_key (char *s, size_t *length)
 777 {
 778   size_t l = 0;
 779
 780   JvAssert (s);
 781
 782   // Skip over whitespace
 783   while (isspace (*s))
 784     s++;
 785
 786   // If we've reached the end, return NULL.  Also return NULL if for
 787   // some reason we've come across a malformed property string.
 788   if (*s == 0
 789       || *s == ':'
 790       || *s == '=')
 791     return NULL;
 792
 793   // Determine the length of the property key.
 794   while (s[l] != 0
 795          && ! isspace (s[l])
 796          && s[l] != ':'
 797          && s[l] != '=')
 798     {
 799       if (s[l] == '\\'
 800           && s[l+1] != 0)
 801         l++;
 802       l++;
 803     }
 804
 805   *length = l;
 806
 807   return s;
 808 }
 809
 810 static char *
 811 next_property_value (char *s, size_t *length)
 812 {
 813   size_t l = 0;
 814
 815   JvAssert (s);
 816
 817   while (isspace (*s))
 818     s++;
 819
 820   if (*s == ':'
 821       || *s == '=')
 822     s++;
 823
 824   while (isspace (*s))
 825     s++;
 826
 827   // If we've reached the end, return NULL.
 828   if (*s == 0)
 829     return NULL;
 830
 831   // Determine the length of the property value.
 832   while (s[l] != 0
 833          && ! isspace (s[l])
 834          && s[l] != ':'
 835          && s[l] != '=')
 836     {
 837       if (s[l] == '\\'
 838           && s[l+1] != 0)
 839         l += 2;
 840       else
 841         l++;
 842     }
 843
 844   *length = l;
 845
 846   return s;
 847 }
 848
 849 static void
 850 process_gcj_properties ()
 851 {
 852   char *props = getenv("GCJ_PROPERTIES");
 853   char *p = props;
 854   size_t length;
 855   size_t property_count = 0;
 856
 857   if (NULL == props)
 858     return;
 859
 860   // Whip through props quickly in order to count the number of
 861   // property values.
 862   while (p && (p = next_property_key (p, &length)))
 863     {
 864       // Skip to the end of the key
 865       p += length;
 866
 867       p = next_property_value (p, &length);
 868       if (p)
 869         p += length;
 870
 871       property_count++;
 872     }
 873
 874   // Allocate an array of property value/key pairs.
 875   _Jv_Environment_Properties =
 876     (property_pair *) malloc (sizeof(property_pair)
 877                               * (property_count + 1));
 878
 879   // Go through the properties again, initializing _Jv_Properties
 880   // along the way.
 881   p = props;
 882   property_count = 0;
 883   while (p && (p = next_property_key (p, &length)))
 884     {
 885       _Jv_Environment_Properties[property_count].key = p;
 886       _Jv_Environment_Properties[property_count].key_length = length;
 887
 888       // Skip to the end of the key
 889       p += length;
 890
 891       p = next_property_value (p, &length);
 892
 893       _Jv_Environment_Properties[property_count].value = p;
 894       _Jv_Environment_Properties[property_count].value_length = length;
 895
 896       if (p)
 897         p += length;
 898
 899       property_count++;
 900     }
 901   memset ((void *) &_Jv_Environment_Properties[property_count],
 902           0, sizeof (property_pair));
 903
 904   // Null terminate the strings.
 905   for (property_pair *prop = &_Jv_Environment_Properties[0];
 906        prop->key != NULL;
 907        prop++)
 908     {
 909       prop->key[prop->key_length] = 0;
 910       prop->value[prop->value_length] = 0;
 911     }
 912 }
 913 #endif // DISABLE_GETENV_PROPERTIES
 914
 915 namespace gcj
 916 {
 917   _Jv_Utf8Const *void_signature;
 918   _Jv_Utf8Const *clinit_name;
 919   _Jv_Utf8Const *init_name;
 920   _Jv_Utf8Const *finit_name;
 921
 922   bool runtimeInitialized = false;
 923
 924   // When true, print debugging information about class loading.
 925   bool verbose_class_flag;
 926
 927   // When true, enable the bytecode verifier and BC-ABI type verification.
 928   bool verifyClasses = true;
 929
 930   // Thread stack size specified by the -Xss runtime argument.
 931   size_t stack_size = 0;
 932 }
 933
 934 // We accept all non-standard options accepted by Sun's java command,
 935 // for compatibility with existing application launch scripts.
 936 static jint
 937 parse_x_arg (char* option_string)
 938 {
 939   if (strlen (option_string) <= 0)
 940     return -1;
 941
 942   if (! strcmp (option_string, "int"))
 943     {
 944       // FIXME: this should cause the vm to never load shared objects
 945     }
 946   else if (! strcmp (option_string, "mixed"))
 947     {
 948       // FIXME: allow interpreted and native code
 949     }
 950   else if (! strcmp (option_string, "batch"))
 951     {
 952       // FIXME: disable background JIT'ing
 953     }
 954   else if (! strcmp (option_string, "debug"))
 955     {
 956       // FIXME: add JDWP/JVMDI support
 957     }
 958   else if (! strncmp (option_string, "bootclasspath:", 14))
 959     {
 960       // FIXME: add a parse_bootclasspath_arg function
 961     }
 962   else if (! strncmp (option_string, "bootclasspath/a:", 16))
 963     {
 964     }
 965   else if (! strncmp (option_string, "bootclasspath/p:", 16))
 966     {
 967     }
 968   else if (! strcmp (option_string, "check:jni"))
 969     {
 970       // FIXME: enable strict JNI checking
 971     }
 972   else if (! strcmp (option_string, "future"))
 973     {
 974       // FIXME: enable strict class file format checks
 975     }
 976   else if (! strcmp (option_string, "noclassgc"))
 977     {
 978       // FIXME: disable garbage collection for classes
 979     }
 980   else if (! strcmp (option_string, "incgc"))
 981     {
 982       // FIXME: incremental garbage collection
 983     }
 984   else if (! strncmp (option_string, "loggc:", 6))
 985     {
 986       if (option_string[6] == '\0')
 987         {
 988           fprintf (stderr,
 989                    "libgcj: filename argument expected for loggc option\n");
 990           return -1;
 991         }
 992       // FIXME: set gc logging filename
 993     }
 994   else if (! strncmp (option_string, "ms", 2))
 995     {
 996       // FIXME: ignore this option until PR 20699 is fixed.
 997       // _Jv_SetInitialHeapSize (option_string + 2);
 998     }
 999   else if (! strncmp (option_string, "mx", 2))
1000     _Jv_SetMaximumHeapSize (option_string + 2);
1001   else if (! strcmp (option_string, "prof"))
1002     {
1003       // FIXME: enable profiling of program running in vm
1004     }
1005   else if (! strncmp (option_string, "runhprof:", 9))
1006     {
1007       // FIXME: enable specific type of vm profiling.  add a
1008       // parse_runhprof_arg function
1009     }
1010   else if (! strcmp (option_string, "rs"))
1011     {
1012       // FIXME: reduced system signal usage.  disable thread dumps,
1013       // only terminate in response to user-initiated calls,
1014       // e.g. System.exit()
1015     }
1016   else if (! strncmp (option_string, "ss", 2))
1017     {
1018       _Jv_SetStackSize (option_string + 2);
1019     }
1020   else if (! strcmp (option_string, "X:+UseAltSigs"))
1021     {
1022       // FIXME: use signals other than SIGUSR1 and SIGUSR2
1023     }
1024   else if (! strcmp (option_string, "share:off"))
1025     {
1026       // FIXME: don't share class data
1027     }
1028   else if (! strcmp (option_string, "share:auto"))
1029     {
1030       // FIXME: share class data where possible
1031     }
1032   else if (! strcmp (option_string, "share:on"))
1033     {
1034       // FIXME: fail if impossible to share class data
1035     }
1036
1037   return 0;
1038 }
1039
1040 static jint
1041 parse_verbose_args (char* option_string,
1042                     bool ignore_unrecognized)
1043 {
1044   size_t len = sizeof ("-verbose") - 1;
1045
1046   if (strlen (option_string) < len)
1047     return -1;
1048
1049   if (option_string[len] == ':'
1050       && option_string[len + 1] != '\0')
1051     {
1052       char* verbose_args = option_string + len + 1;
1053
1054       do
1055         {
1056           if (! strncmp (verbose_args,
1057                          "gc", sizeof ("gc") - 1))
1058             {
1059               if (verbose_args[sizeof ("gc") - 1] == '\0'
1060                   || verbose_args[sizeof ("gc") - 1] == ',')
1061                 {
1062                   // FIXME: we should add functions to boehm-gc that
1063                   // toggle GC_print_stats, GC_PRINT_ADDRESS_MAP and
1064                   // GC_print_back_height.
1065                   verbose_args += sizeof ("gc") - 1;
1066                 }
1067               else
1068                 {
1069                 verbose_arg_err:
1070                   fprintf (stderr, "libgcj: unknown verbose option: %s\n",
1071                            option_string);
1072                   return -1;
1073                 }
1074             }
1075           else if (! strncmp (verbose_args,
1076                               "class",
1077                               sizeof ("class") - 1))
1078             {
1079               if (verbose_args[sizeof ("class") - 1] == '\0'
1080                   || verbose_args[sizeof ("class") - 1] == ',')
1081                 {
1082                   gcj::verbose_class_flag = true;
1083                   verbose_args += sizeof ("class") - 1;
1084                 }
1085               else
1086                 goto verbose_arg_err;
1087             }
1088           else if (! strncmp (verbose_args, "jni",
1089                               sizeof ("jni") - 1))
1090             {
1091               if (verbose_args[sizeof ("jni") - 1] == '\0'
1092                   || verbose_args[sizeof ("jni") - 1] == ',')
1093                 {
1094                   // FIXME: enable JNI messages.
1095                   verbose_args += sizeof ("jni") - 1;
1096                 }
1097               else
1098                 goto verbose_arg_err;
1099             }
1100           else if (ignore_unrecognized
1101                    && verbose_args[0] == 'X')
1102             {
1103               // ignore unrecognized non-standard verbose option
1104               while (verbose_args[0] != '\0'
1105                      && verbose_args[0] != ',')
1106                 verbose_args++;
1107             }
1108           else if (verbose_args[0] == ',')
1109             {
1110               verbose_args++;
1111             }
1112           else
1113             goto verbose_arg_err;
1114
1115           if (verbose_args[0] == ',')
1116             verbose_args++;
1117         }
1118       while (verbose_args[0] != '\0');
1119     }
1120   else if (option_string[len] == 'g'
1121            && option_string[len + 1] == 'c'
1122            && option_string[len + 2] == '\0')
1123     {
1124       // FIXME: we should add functions to boehm-gc that
1125       // toggle GC_print_stats, GC_PRINT_ADDRESS_MAP and
1126       // GC_print_back_height.
1127       return 0;
1128     }
1129   else if (option_string[len] == '\0')
1130     {
1131       gcj::verbose_class_flag = true;
1132       return 0;
1133     }
1134   else
1135     {
1136       // unrecognized option beginning with -verbose
1137       return -1;
1138     }
1139   return 0;
1140 }
1141
1142 static jint
1143 parse_init_args (JvVMInitArgs* vm_args)
1144 {
1145   // if _Jv_Compiler_Properties is non-NULL then it needs to be
1146   // re-allocated dynamically.
1147   if (_Jv_Compiler_Properties)
1148     {
1149       const char** props = _Jv_Compiler_Properties;
1150       _Jv_Compiler_Properties = NULL;
1151
1152       for (int i = 0; props[i]; i++)
1153         {
1154           _Jv_Compiler_Properties = (const char**) _Jv_Realloc
1155             (_Jv_Compiler_Properties,
1156              (_Jv_Properties_Count + 1) * sizeof (const char*));
1157           _Jv_Compiler_Properties[_Jv_Properties_Count++] = props[i];
1158         }
1159     }
1160
1161   if (vm_args == NULL)
1162     return 0;
1163
1164   for (int i = 0; i < vm_args->nOptions; ++i)
1165     {
1166       char* option_string = vm_args->options[i].optionString;
1167       if (! strcmp (option_string, "vfprintf")
1168           || ! strcmp (option_string, "exit")
1169           || ! strcmp (option_string, "abort"))
1170         {
1171           // FIXME: we are required to recognize these, but for
1172           // now we don't handle them in any way.
1173           continue;
1174         }
1175       else if (! strncmp (option_string,
1176                           "-verbose", sizeof ("-verbose") - 1))
1177         {
1178           jint result = parse_verbose_args (option_string,
1179                                             vm_args->ignoreUnrecognized);
1180           if (result < 0)
1181             return result;
1182         }
1183       else if (! strncmp (option_string, "-D", 2))
1184         {
1185           _Jv_Compiler_Properties = (const char**) _Jv_Realloc
1186             (_Jv_Compiler_Properties,
1187              (_Jv_Properties_Count + 1) * sizeof (char*));
1188
1189           _Jv_Compiler_Properties[_Jv_Properties_Count++] =
1190             strdup (option_string + 2);
1191
1192           continue;
1193         }
1194       else if (vm_args->ignoreUnrecognized)
1195         {
1196           if (option_string[0] == '_')
1197             parse_x_arg (option_string + 1);
1198           else if (! strncmp (option_string, "-X", 2))
1199             parse_x_arg (option_string + 2);
1200           else
1201             {
1202             unknown_option:
1203               fprintf (stderr, "libgcj: unknown option: %s\n", option_string);
1204               return -1;
1205             }
1206         }
1207       else
1208         goto unknown_option;
1209     }
1210   return 0;
1211 }
1212
1213 jint
1214 _Jv_CreateJavaVM (JvVMInitArgs* vm_args)
1215 {
1216   using namespace gcj;
1217
1218   if (runtimeInitialized)
1219     return -1;
1220
1221   runtimeInitialized = true;
1222
1223   jint result = parse_init_args (vm_args);
1224   if (result < 0)
1225     return -1;
1226
1227   PROCESS_GCJ_PROPERTIES;
1228
1229   /* Threads must be initialized before the GC, so that it inherits the
1230      signal mask.  */
1231   _Jv_InitThreads ();
1232   _Jv_InitGC ();
1233   _Jv_InitializeSyncMutex ();
1234
1235 #ifdef INTERPRETER
1236   _Jv_InitInterpreter ();
1237 #endif
1238
1239 #ifdef HANDLE_SEGV
1240   INIT_SEGV;
1241 #endif
1242
1243 #ifdef HANDLE_FPE
1244   INIT_FPE;
1245 #endif
1246
1247   /* Initialize Utf8 constants declared in jvm.h. */
1248   void_signature = _Jv_makeUtf8Const ("()V", 3);
1249   clinit_name = _Jv_makeUtf8Const ("<clinit>", 8);
1250   init_name = _Jv_makeUtf8Const ("<init>", 6);
1251   finit_name = _Jv_makeUtf8Const ("finit$", 6);
1252
1253   /* Initialize built-in classes to represent primitive TYPEs. */
1254   _Jv_InitPrimClass (&_Jv_byteClass,    "byte",    'B', 1);
1255   _Jv_InitPrimClass (&_Jv_shortClass,   "short",   'S', 2);
1256   _Jv_InitPrimClass (&_Jv_intClass,     "int",     'I', 4);
1257   _Jv_InitPrimClass (&_Jv_longClass,    "long",    'J', 8);
1258   _Jv_InitPrimClass (&_Jv_booleanClass, "boolean", 'Z', 1);
1259   _Jv_InitPrimClass (&_Jv_charClass,    "char",    'C', 2);
1260   _Jv_InitPrimClass (&_Jv_floatClass,   "float",   'F', 4);
1261   _Jv_InitPrimClass (&_Jv_doubleClass,  "double",  'D', 8);
1262   _Jv_InitPrimClass (&_Jv_voidClass,    "void",    'V', 0);
1263
1264   // Turn stack trace generation off while creating exception objects.
1265   _Jv_InitClass (&java::lang::VMThrowable::class$);
1266   java::lang::VMThrowable::trace_enabled = 0;
1267
1268   // We have to initialize this fairly early, to avoid circular class
1269   // initialization.  In particular we want to start the
1270   // initialization of ClassLoader before we start the initialization
1271   // of VMClassLoader.
1272   _Jv_InitClass (&java::lang::ClassLoader::class$);
1273
1274   // Set up the system class loader and the bootstrap class loader.
1275   gnu::gcj::runtime::ExtensionClassLoader::initialize();
1276   java::lang::VMClassLoader::initialize(JvNewStringLatin1(TOOLEXECLIBDIR));
1277
1278   _Jv_RegisterBootstrapPackages();
1279
1280   no_memory = new java::lang::OutOfMemoryError;
1281
1282   java::lang::VMThrowable::trace_enabled = 1;
1283
1284 #ifdef USE_LTDL
1285   LTDL_SET_PRELOADED_SYMBOLS ();
1286 #endif
1287
1288   _Jv_platform_initialize ();
1289
1290   _Jv_JNI_Init ();
1291
1292   _Jv_GCInitializeFinalizers (&::gnu::gcj::runtime::FinalizerThread::finalizerReady);
1293
1294   // Start the GC finalizer thread.  A VirtualMachineError can be
1295   // thrown by the runtime if, say, threads aren't available.
1296   try
1297     {
1298       using namespace gnu::gcj::runtime;
1299       FinalizerThread *ft = new FinalizerThread ();
1300       ft->start ();
1301     }
1302   catch (java::lang::VirtualMachineError *ignore)
1303     {
1304     }
1305
1306   return 0;
1307 }
1308
1309 void
1310 _Jv_RunMain (JvVMInitArgs *vm_args, jclass klass, const char *name, int argc,
1311              const char **argv, bool is_jar)
1312 {
1313 #ifndef DISABLE_MAIN_ARGS
1314   _Jv_SetArgs (argc, argv);
1315 #endif
1316
1317   java::lang::Runtime *runtime = NULL;
1318
1319   try
1320     {
1321       if (_Jv_CreateJavaVM (vm_args) < 0)
1322         {
1323           fprintf (stderr, "libgcj: couldn't create virtual machine\n");
1324           exit (1);
1325         }
1326
1327       // Get the Runtime here.  We want to initialize it before searching
1328       // for `main'; that way it will be set up if `main' is a JNI method.
1329       runtime = java::lang::Runtime::getRuntime ();
1330
1331 #ifdef DISABLE_MAIN_ARGS
1332       arg_vec = JvConvertArgv (0, 0);
1333 #else
1334       arg_vec = JvConvertArgv (argc - 1, argv + 1);
1335 #endif
1336
1337       using namespace gnu::java::lang;
1338       if (klass)
1339         main_thread = new MainThread (klass, arg_vec);
1340       else
1341         main_thread = new MainThread (JvNewStringLatin1 (name),
1342                                       arg_vec, is_jar);
1343     }
1344   catch (java::lang::Throwable *t)
1345     {
1346       java::lang::System::err->println (JvNewStringLatin1
1347         ("Exception during runtime initialization"));
1348       t->printStackTrace();
1349       if (runtime)
1350         runtime->exit (1);
1351       // In case the runtime creation failed.
1352       ::exit (1);
1353     }
1354
1355   _Jv_AttachCurrentThread (main_thread);
1356   _Jv_ThreadRun (main_thread);
1357   _Jv_ThreadWait ();
1358
1359   int status = (int) java::lang::ThreadGroup::had_uncaught_exception;
1360   runtime->exit (status);
1361 }
1362
1363 void
1364 _Jv_RunMain (jclass klass, const char *name, int argc, const char **argv,
1365              bool is_jar)
1366 {
1367   _Jv_RunMain (NULL, klass, name, argc, argv, is_jar);
1368 }
1369
1370 void
1371 JvRunMain (jclass klass, int argc, const char **argv)
1372 {
1373   _Jv_RunMain (klass, NULL, argc, argv, false);
1374 }
1375
1376 \f
1377
1378 // Parse a string and return a heap size.
1379 static size_t
1380 parse_memory_size (const char *spec)
1381 {
1382   char *end;
1383   unsigned long val = strtoul (spec, &end, 10);
1384   if (*end == 'k' || *end == 'K')
1385     val *= 1024;
1386   else if (*end == 'm' || *end == 'M')
1387     val *= 1048576;
1388   return (size_t) val;
1389 }
1390
1391 // Set the initial heap size.  This might be ignored by the GC layer.
1392 // This must be called before _Jv_RunMain.
1393 void
1394 _Jv_SetInitialHeapSize (const char *arg)
1395 {
1396   size_t size = parse_memory_size (arg);
1397   _Jv_GCSetInitialHeapSize (size);
1398 }
1399
1400 // Set the maximum heap size.  This might be ignored by the GC layer.
1401 // This must be called before _Jv_RunMain.
1402 void
1403 _Jv_SetMaximumHeapSize (const char *arg)
1404 {
1405   size_t size = parse_memory_size (arg);
1406   _Jv_GCSetMaximumHeapSize (size);
1407 }
1408
1409 void
1410 _Jv_SetStackSize (const char *arg)
1411 {
1412   size_t size = parse_memory_size (arg);
1413   gcj::stack_size = size;
1414 }
1415
1416 void *
1417 _Jv_Malloc (jsize size)
1418 {
1419   if (__builtin_expect (size == 0, false))
1420     size = 1;
1421   void *ptr = malloc ((size_t) size);
1422   if (__builtin_expect (ptr == NULL, false))
1423     throw no_memory;
1424   return ptr;
1425 }
1426
1427 void *
1428 _Jv_Realloc (void *ptr, jsize size)
1429 {
1430   if (__builtin_expect (size == 0, false))
1431     size = 1;
1432   ptr = realloc (ptr, (size_t) size);
1433   if (__builtin_expect (ptr == NULL, false))
1434     throw no_memory;
1435   return ptr;
1436 }
1437
1438 void *
1439 _Jv_MallocUnchecked (jsize size)
1440 {
1441   if (__builtin_expect (size == 0, false))
1442     size = 1;
1443   return malloc ((size_t) size);
1444 }
1445
1446 void
1447 _Jv_Free (void* ptr)
1448 {
1449   return free (ptr);
1450 }
1451
1452 \f
1453
1454 // In theory, these routines can be #ifdef'd away on machines which
1455 // support divide overflow signals.  However, we never know if some
1456 // code might have been compiled with "-fuse-divide-subroutine", so we
1457 // always include them in libgcj.
1458
1459 jint
1460 _Jv_divI (jint dividend, jint divisor)
1461 {
1462   if (__builtin_expect (divisor == 0, false))
1463     {
1464       java::lang::ArithmeticException *arithexception
1465         = new java::lang::ArithmeticException (JvNewStringLatin1 ("/ by zero"));
1466       throw arithexception;
1467     }
1468
1469   if (dividend == (jint) 0x80000000L && divisor == -1)
1470     return dividend;
1471
1472   return dividend / divisor;
1473 }
1474
1475 jint
1476 _Jv_remI (jint dividend, jint divisor)
1477 {
1478   if (__builtin_expect (divisor == 0, false))
1479     {
1480       java::lang::ArithmeticException *arithexception
1481         = new java::lang::ArithmeticException (JvNewStringLatin1 ("/ by zero"));
1482       throw arithexception;
1483     }
1484
1485   if (dividend == (jint) 0x80000000L && divisor == -1)
1486     return 0;
1487
1488   return dividend % divisor;
1489 }
1490
1491 jlong
1492 _Jv_divJ (jlong dividend, jlong divisor)
1493 {
1494   if (__builtin_expect (divisor == 0, false))
1495     {
1496       java::lang::ArithmeticException *arithexception
1497         = new java::lang::ArithmeticException (JvNewStringLatin1 ("/ by zero"));
1498       throw arithexception;
1499     }
1500
1501   if (dividend == (jlong) 0x8000000000000000LL && divisor == -1)
1502     return dividend;
1503
1504   return dividend / divisor;
1505 }
1506
1507 jlong
1508 _Jv_remJ (jlong dividend, jlong divisor)
1509 {
1510   if (__builtin_expect (divisor == 0, false))
1511     {
1512       java::lang::ArithmeticException *arithexception
1513         = new java::lang::ArithmeticException (JvNewStringLatin1 ("/ by zero"));
1514       throw arithexception;
1515     }
1516
1517   if (dividend == (jlong) 0x8000000000000000LL && divisor == -1)
1518     return 0;
1519
1520   return dividend % divisor;
1521 }
1522
1523 \f
1524
1525 // Return true if SELF_KLASS can access a field or method in
1526 // OTHER_KLASS.  The field or method's access flags are specified in
1527 // FLAGS.
1528 jboolean
1529 _Jv_CheckAccess (jclass self_klass, jclass other_klass, jint flags)
1530 {
1531   using namespace java::lang::reflect;
1532   return ((self_klass == other_klass)
1533           || ((flags & Modifier::PUBLIC) != 0)
1534           || (((flags & Modifier::PROTECTED) != 0)
1535               && _Jv_IsAssignableFromSlow (other_klass, self_klass))
1536           || (((flags & Modifier::PRIVATE) == 0)
1537               && _Jv_ClassNameSamePackage (self_klass->name,
1538                                            other_klass->name)));
1539 }