libjava/prims.cc

   1 // prims.cc - Code for core of runtime environment.
   2
   3 /* Copyright (C) 1998, 1999, 2000, 2001, 2002  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
  29 #ifdef ENABLE_JVMPI
  30 #include <jvmpi.h>
  31 #include <java/lang/ThreadGroup.h>
  32 #endif
  33
  34 #ifndef DISABLE_GETENV_PROPERTIES
  35 #include <ctype.h>
  36 #include <java-props.h>
  37 #define PROCESS_GCJ_PROPERTIES process_gcj_properties()
  38 #else
  39 #define PROCESS_GCJ_PROPERTIES
  40 #endif // DISABLE_GETENV_PROPERTIES
  41
  42 #include <java/lang/Class.h>
  43 #include <java/lang/ClassLoader.h>
  44 #include <java/lang/Runtime.h>
  45 #include <java/lang/String.h>
  46 #include <java/lang/Thread.h>
  47 #include <java/lang/ThreadGroup.h>
  48 #include <java/lang/ArrayIndexOutOfBoundsException.h>
  49 #include <java/lang/ArithmeticException.h>
  50 #include <java/lang/ClassFormatError.h>
  51 #include <java/lang/InternalError.h>
  52 #include <java/lang/NegativeArraySizeException.h>
  53 #include <java/lang/NullPointerException.h>
  54 #include <java/lang/OutOfMemoryError.h>
  55 #include <java/lang/System.h>
  56 #include <java/lang/reflect/Modifier.h>
  57 #include <java/io/PrintStream.h>
  58 #include <java/lang/UnsatisfiedLinkError.h>
  59 #include <java/lang/VirtualMachineError.h>
  60 #include <gnu/gcj/runtime/VMClassLoader.h>
  61 #include <gnu/gcj/runtime/FinalizerThread.h>
  62 #include <gnu/gcj/runtime/FirstThread.h>
  63
  64 #ifdef USE_LTDL
  65 #include <ltdl.h>
  66 #endif
  67
  68 // We allocate a single OutOfMemoryError exception which we keep
  69 // around for use if we run out of memory.
  70 static java::lang::OutOfMemoryError *no_memory;
  71
  72 // Largest representable size_t.
  73 #define SIZE_T_MAX ((size_t) (~ (size_t) 0))
  74
  75 static const char *no_properties[] = { NULL };
  76
  77 // Properties set at compile time.
  78 const char **_Jv_Compiler_Properties = no_properties;
  79
  80 // The JAR file to add to the beginning of java.class.path.
  81 const char *_Jv_Jar_Class_Path;
  82
  83 #ifndef DISABLE_GETENV_PROPERTIES
  84 // Property key/value pairs.
  85 property_pair *_Jv_Environment_Properties;
  86 #endif
  87
  88 // The name of this executable.
  89 static char *_Jv_execName;
  90
  91 // Stash the argv pointer to benefit native libraries that need it.
  92 const char **_Jv_argv;
  93 int _Jv_argc;
  94
  95 #ifdef ENABLE_JVMPI
  96 // Pointer to JVMPI notification functions.
  97 void (*_Jv_JVMPI_Notify_OBJECT_ALLOC) (JVMPI_Event *event);
  98 void (*_Jv_JVMPI_Notify_THREAD_START) (JVMPI_Event *event);
  99 void (*_Jv_JVMPI_Notify_THREAD_END) (JVMPI_Event *event);
 100 #endif
 101 \f
 102
 103 extern "C" void _Jv_ThrowSignal (jthrowable) __attribute ((noreturn));
 104
 105 // Just like _Jv_Throw, but fill in the stack trace first.  Although
 106 // this is declared extern in order that its name not be mangled, it
 107 // is not intended to be used outside this file.
 108 void
 109 _Jv_ThrowSignal (jthrowable throwable)
 110 {
 111   throwable->fillInStackTrace ();
 112   throw throwable;
 113 }
 114
 115 #ifdef HANDLE_SEGV
 116 static java::lang::NullPointerException *nullp;
 117
 118 SIGNAL_HANDLER (catch_segv)
 119 {
 120   MAKE_THROW_FRAME (nullp);
 121   _Jv_ThrowSignal (nullp);
 122 }
 123 #endif
 124
 125 static java::lang::ArithmeticException *arithexception;
 126
 127 #ifdef HANDLE_FPE
 128 SIGNAL_HANDLER (catch_fpe)
 129 {
 130 #ifdef HANDLE_DIVIDE_OVERFLOW
 131   HANDLE_DIVIDE_OVERFLOW;
 132 #else
 133   MAKE_THROW_FRAME (arithexception);
 134 #endif
 135   _Jv_ThrowSignal (arithexception);
 136 }
 137 #endif
 138
 139 \f
 140
 141 jboolean
 142 _Jv_equalUtf8Consts (Utf8Const* a, Utf8Const *b)
 143 {
 144   int len;
 145   _Jv_ushort *aptr, *bptr;
 146   if (a == b)
 147     return true;
 148   if (a->hash != b->hash)
 149     return false;
 150   len = a->length;
 151   if (b->length != len)
 152     return false;
 153   aptr = (_Jv_ushort *)a->data;
 154   bptr = (_Jv_ushort *)b->data;
 155   len = (len + 1) >> 1;
 156   while (--len >= 0)
 157     if (*aptr++ != *bptr++)
 158       return false;
 159   return true;
 160 }
 161
 162 /* True iff A is equal to STR.
 163    HASH is STR->hashCode().
 164 */
 165
 166 jboolean
 167 _Jv_equal (Utf8Const* a, jstring str, jint hash)
 168 {
 169   if (a->hash != (_Jv_ushort) hash)
 170     return false;
 171   jint len = str->length();
 172   jint i = 0;
 173   jchar *sptr = _Jv_GetStringChars (str);
 174   unsigned char* ptr = (unsigned char*) a->data;
 175   unsigned char* limit = ptr + a->length;
 176   for (;; i++, sptr++)
 177     {
 178       int ch = UTF8_GET (ptr, limit);
 179       if (i == len)
 180         return ch < 0;
 181       if (ch != *sptr)
 182         return false;
 183     }
 184   return true;
 185 }
 186
 187 /* Like _Jv_equal, but stop after N characters.  */
 188 jboolean
 189 _Jv_equaln (Utf8Const *a, jstring str, jint n)
 190 {
 191   jint len = str->length();
 192   jint i = 0;
 193   jchar *sptr = _Jv_GetStringChars (str);
 194   unsigned char* ptr = (unsigned char*) a->data;
 195   unsigned char* limit = ptr + a->length;
 196   for (; n-- > 0; i++, sptr++)
 197     {
 198       int ch = UTF8_GET (ptr, limit);
 199       if (i == len)
 200         return ch < 0;
 201       if (ch != *sptr)
 202         return false;
 203     }
 204   return true;
 205 }
 206
 207 /* Count the number of Unicode chars encoded in a given Ut8 string. */
 208 int
 209 _Jv_strLengthUtf8(char* str, int len)
 210 {
 211   unsigned char* ptr;
 212   unsigned char* limit;
 213   int str_length;
 214
 215   ptr = (unsigned char*) str;
 216   limit = ptr + len;
 217   str_length = 0;
 218   for (; ptr < limit; str_length++)
 219     {
 220       if (UTF8_GET (ptr, limit) < 0)
 221         return (-1);
 222     }
 223   return (str_length);
 224 }
 225
 226 /* Calculate a hash value for a string encoded in Utf8 format.
 227  * This returns the same hash value as specified or java.lang.String.hashCode.
 228  */
 229 static jint
 230 hashUtf8String (char* str, int len)
 231 {
 232   unsigned char* ptr = (unsigned char*) str;
 233   unsigned char* limit = ptr + len;
 234   jint hash = 0;
 235
 236   for (; ptr < limit;)
 237     {
 238       int ch = UTF8_GET (ptr, limit);
 239       /* Updated specification from
 240          http://www.javasoft.com/docs/books/jls/clarify.html. */
 241       hash = (31 * hash) + ch;
 242     }
 243   return hash;
 244 }
 245
 246 _Jv_Utf8Const *
 247 _Jv_makeUtf8Const (char* s, int len)
 248 {
 249   if (len < 0)
 250     len = strlen (s);
 251   Utf8Const* m = (Utf8Const*) _Jv_AllocBytes (sizeof(Utf8Const) + len + 1);
 252   memcpy (m->data, s, len);
 253   m->data[len] = 0;
 254   m->length = len;
 255   m->hash = hashUtf8String (s, len) & 0xFFFF;
 256   return (m);
 257 }
 258
 259 _Jv_Utf8Const *
 260 _Jv_makeUtf8Const (jstring string)
 261 {
 262   jint hash = string->hashCode ();
 263   jint len = _Jv_GetStringUTFLength (string);
 264
 265   Utf8Const* m = (Utf8Const*)
 266     _Jv_AllocBytes (sizeof(Utf8Const) + len + 1);
 267
 268   m->hash = hash;
 269   m->length = len;
 270
 271   _Jv_GetStringUTFRegion (string, 0, string->length (), m->data);
 272   m->data[len] = 0;
 273
 274   return m;
 275 }
 276
 277 \f
 278
 279 #ifdef DEBUG
 280 void
 281 _Jv_Abort (const char *function, const char *file, int line,
 282            const char *message)
 283 #else
 284 void
 285 _Jv_Abort (const char *, const char *, int, const char *message)
 286 #endif
 287 {
 288 #ifdef DEBUG
 289   fprintf (stderr,
 290            "libgcj failure: %s\n   in function %s, file %s, line %d\n",
 291            message, function, file, line);
 292 #else
 293   fprintf (stderr, "libgcj failure: %s\n", message);
 294 #endif
 295   abort ();
 296 }
 297
 298 static void
 299 fail_on_finalization (jobject)
 300 {
 301   JvFail ("object was finalized");
 302 }
 303
 304 void
 305 _Jv_GCWatch (jobject obj)
 306 {
 307   _Jv_RegisterFinalizer (obj, fail_on_finalization);
 308 }
 309
 310 void
 311 _Jv_ThrowBadArrayIndex(jint bad_index)
 312 {
 313   throw new java::lang::ArrayIndexOutOfBoundsException
 314     (java::lang::String::valueOf (bad_index));
 315 }
 316
 317 void
 318 _Jv_ThrowNullPointerException ()
 319 {
 320   throw new java::lang::NullPointerException;
 321 }
 322
 323 // Explicitly throw a no memory exception.
 324 // The collector calls this when it encounters an out-of-memory condition.
 325 void _Jv_ThrowNoMemory()
 326 {
 327   throw no_memory;
 328 }
 329
 330 #ifdef ENABLE_JVMPI
 331 static void
 332 jvmpi_notify_alloc(jclass klass, jint size, jobject obj)
 333 {
 334   // Service JVMPI allocation request.
 335   if (__builtin_expect (_Jv_JVMPI_Notify_OBJECT_ALLOC != 0, false))
 336     {
 337       JVMPI_Event event;
 338
 339       event.event_type = JVMPI_EVENT_OBJECT_ALLOC;
 340       event.env_id = NULL;
 341       event.u.obj_alloc.arena_id = 0;
 342       event.u.obj_alloc.class_id = (jobjectID) klass;
 343       event.u.obj_alloc.is_array = 0;
 344       event.u.obj_alloc.size = size;
 345       event.u.obj_alloc.obj_id = (jobjectID) obj;
 346
 347       // FIXME:  This doesn't look right for the Boehm GC.  A GC may
 348       // already be in progress.  _Jv_DisableGC () doesn't wait for it.
 349       // More importantly, I don't see the need for disabling GC, since we
 350       // blatantly have a pointer to obj on our stack, ensuring that the
 351       // object can't be collected.  Even for a nonconservative collector,
 352       // it appears to me that this must be true, since we are about to
 353       // return obj. Isn't this whole approach way too intrusive for
 354       // a useful profiling interface?                  - HB
 355       _Jv_DisableGC ();
 356       (*_Jv_JVMPI_Notify_OBJECT_ALLOC) (&event);
 357       _Jv_EnableGC ();
 358     }
 359 }
 360 #else /* !ENABLE_JVMPI */
 361 # define jvmpi_notify_alloc(klass,size,obj) /* do nothing */
 362 #endif
 363
 364 // Allocate a new object of class KLASS.  SIZE is the size of the object
 365 // to allocate.  You might think this is redundant, but it isn't; some
 366 // classes, such as String, aren't of fixed size.
 367 // First a version that assumes that we have no finalizer, and that
 368 // the class is already initialized.
 369 // If we know that JVMPI is disabled, this can be replaced by a direct call
 370 // to the allocator for the appropriate GC.
 371 jobject
 372 _Jv_AllocObjectNoInitNoFinalizer (jclass klass, jint size)
 373 {
 374   jobject obj = (jobject) _Jv_AllocObj (size, klass);
 375   jvmpi_notify_alloc (klass, size, obj);
 376   return obj;
 377 }
 378
 379 // And now a version that initializes if necessary.
 380 jobject
 381 _Jv_AllocObjectNoFinalizer (jclass klass, jint size)
 382 {
 383   _Jv_InitClass (klass);
 384   jobject obj = (jobject) _Jv_AllocObj (size, klass);
 385   jvmpi_notify_alloc (klass, size, obj);
 386   return obj;
 387 }
 388
 389 // And now the general version that registers a finalizer if necessary.
 390 jobject
 391 _Jv_AllocObject (jclass klass, jint size)
 392 {
 393   jobject obj = _Jv_AllocObjectNoFinalizer (klass, size);
 394
 395   // We assume that the compiler only generates calls to this routine
 396   // if there really is an interesting finalizer.
 397   // Unfortunately, we still have to the dynamic test, since there may
 398   // be cni calls to this routine.
 399   // Nore that on IA64 get_finalizer() returns the starting address of the
 400   // function, not a function pointer.  Thus this still works.
 401   if (klass->vtable->get_finalizer ()
 402       != java::lang::Object::class$.vtable->get_finalizer ())
 403     _Jv_RegisterFinalizer (obj, _Jv_FinalizeObject);
 404   return obj;
 405 }
 406
 407 // A version of the above that assumes the object contains no pointers,
 408 // and requires no finalization.  This can't happen if we need pointers
 409 // to locks.
 410 #ifdef JV_HASH_SYNCHRONIZATION
 411 jobject
 412 _Jv_AllocPtrFreeObject (jclass klass, jint size)
 413 {
 414   _Jv_InitClass (klass);
 415
 416   jobject obj = (jobject) _Jv_AllocPtrFreeObj (size, klass);
 417
 418 #ifdef ENABLE_JVMPI
 419   // Service JVMPI request.
 420
 421   if (__builtin_expect (_Jv_JVMPI_Notify_OBJECT_ALLOC != 0, false))
 422     {
 423       JVMPI_Event event;
 424
 425       event.event_type = JVMPI_EVENT_OBJECT_ALLOC;
 426       event.env_id = NULL;
 427       event.u.obj_alloc.arena_id = 0;
 428       event.u.obj_alloc.class_id = (jobjectID) klass;
 429       event.u.obj_alloc.is_array = 0;
 430       event.u.obj_alloc.size = size;
 431       event.u.obj_alloc.obj_id = (jobjectID) obj;
 432
 433       _Jv_DisableGC ();
 434       (*_Jv_JVMPI_Notify_OBJECT_ALLOC) (&event);
 435       _Jv_EnableGC ();
 436     }
 437 #endif
 438
 439   return obj;
 440 }
 441 #endif /* JV_HASH_SYNCHRONIZATION */
 442
 443
 444 // Allocate a new array of Java objects.  Each object is of type
 445 // `elementClass'.  `init' is used to initialize each slot in the
 446 // array.
 447 jobjectArray
 448 _Jv_NewObjectArray (jsize count, jclass elementClass, jobject init)
 449 {
 450   if (__builtin_expect (count < 0, false))
 451     throw new java::lang::NegativeArraySizeException;
 452
 453   JvAssert (! elementClass->isPrimitive ());
 454
 455   // Ensure that elements pointer is properly aligned.
 456   jobjectArray obj = NULL;
 457   size_t size = (size_t) elements (obj);
 458   size += count * sizeof (jobject);
 459
 460   // FIXME: second argument should be "current loader"
 461   jclass klass = _Jv_GetArrayClass (elementClass, 0);
 462
 463   obj = (jobjectArray) _Jv_AllocArray (size, klass);
 464   // Cast away const.
 465   jsize *lp = const_cast<jsize *> (&obj->length);
 466   *lp = count;
 467   // We know the allocator returns zeroed memory.  So don't bother
 468   // zeroing it again.
 469   if (init)
 470     {
 471       jobject *ptr = elements(obj);
 472       while (--count >= 0)
 473         *ptr++ = init;
 474     }
 475   return obj;
 476 }
 477
 478 // Allocate a new array of primitives.  ELTYPE is the type of the
 479 // element, COUNT is the size of the array.
 480 jobject
 481 _Jv_NewPrimArray (jclass eltype, jint count)
 482 {
 483   int elsize = eltype->size();
 484   if (__builtin_expect (count < 0, false))
 485     throw new java::lang::NegativeArraySizeException;
 486
 487   JvAssert (eltype->isPrimitive ());
 488   jobject dummy = NULL;
 489   size_t size = (size_t) _Jv_GetArrayElementFromElementType (dummy, eltype);
 490
 491   // Check for overflow.
 492   if (__builtin_expect ((size_t) count >
 493                         (SIZE_T_MAX - size) / elsize, false))
 494     throw no_memory;
 495
 496   jclass klass = _Jv_GetArrayClass (eltype, 0);
 497
 498 # ifdef JV_HASH_SYNCHRONIZATION
 499   // Since the vtable is always statically allocated,
 500   // these are completely pointerfree!  Make sure the GC doesn't touch them.
 501   __JArray *arr =
 502     (__JArray*) _Jv_AllocPtrFreeObj (size + elsize * count, klass);
 503   memset((char *)arr + size, 0, elsize * count);
 504 # else
 505   __JArray *arr = (__JArray*) _Jv_AllocObj (size + elsize * count, klass);
 506   // Note that we assume we are given zeroed memory by the allocator.
 507 # endif
 508   // Cast away const.
 509   jsize *lp = const_cast<jsize *> (&arr->length);
 510   *lp = count;
 511
 512   return arr;
 513 }
 514
 515 jobject
 516 _Jv_NewArray (jint type, jint size)
 517 {
 518   switch (type)
 519     {
 520       case  4:  return JvNewBooleanArray (size);
 521       case  5:  return JvNewCharArray (size);
 522       case  6:  return JvNewFloatArray (size);
 523       case  7:  return JvNewDoubleArray (size);
 524       case  8:  return JvNewByteArray (size);
 525       case  9:  return JvNewShortArray (size);
 526       case 10:  return JvNewIntArray (size);
 527       case 11:  return JvNewLongArray (size);
 528     }
 529   throw new java::lang::InternalError
 530     (JvNewStringLatin1 ("invalid type code in _Jv_NewArray"));
 531 }
 532
 533 // Allocate a possibly multi-dimensional array but don't check that
 534 // any array length is <0.
 535 static jobject
 536 _Jv_NewMultiArrayUnchecked (jclass type, jint dimensions, jint *sizes)
 537 {
 538   JvAssert (type->isArray());
 539   jclass element_type = type->getComponentType();
 540   jobject result;
 541   if (element_type->isPrimitive())
 542     result = _Jv_NewPrimArray (element_type, sizes[0]);
 543   else
 544     result = _Jv_NewObjectArray (sizes[0], element_type, NULL);
 545
 546   if (dimensions > 1)
 547     {
 548       JvAssert (! element_type->isPrimitive());
 549       JvAssert (element_type->isArray());
 550       jobject *contents = elements ((jobjectArray) result);
 551       for (int i = 0; i < sizes[0]; ++i)
 552         contents[i] = _Jv_NewMultiArrayUnchecked (element_type, dimensions - 1,
 553                                                   sizes + 1);
 554     }
 555
 556   return result;
 557 }
 558
 559 jobject
 560 _Jv_NewMultiArray (jclass type, jint dimensions, jint *sizes)
 561 {
 562   for (int i = 0; i < dimensions; ++i)
 563     if (sizes[i] < 0)
 564       throw new java::lang::NegativeArraySizeException;
 565
 566   return _Jv_NewMultiArrayUnchecked (type, dimensions, sizes);
 567 }
 568
 569 jobject
 570 _Jv_NewMultiArray (jclass array_type, jint dimensions, ...)
 571 {
 572   va_list args;
 573   jint sizes[dimensions];
 574   va_start (args, dimensions);
 575   for (int i = 0; i < dimensions; ++i)
 576     {
 577       jint size = va_arg (args, jint);
 578       if (size < 0)
 579         throw new java::lang::NegativeArraySizeException;
 580       sizes[i] = size;
 581     }
 582   va_end (args);
 583
 584   return _Jv_NewMultiArrayUnchecked (array_type, dimensions, sizes);
 585 }
 586
 587 \f
 588
 589 #define DECLARE_PRIM_TYPE(NAME)                 \
 590   _Jv_ArrayVTable _Jv_##NAME##VTable;           \
 591   java::lang::Class _Jv_##NAME##Class;
 592
 593 DECLARE_PRIM_TYPE(byte);
 594 DECLARE_PRIM_TYPE(short);
 595 DECLARE_PRIM_TYPE(int);
 596 DECLARE_PRIM_TYPE(long);
 597 DECLARE_PRIM_TYPE(boolean);
 598 DECLARE_PRIM_TYPE(char);
 599 DECLARE_PRIM_TYPE(float);
 600 DECLARE_PRIM_TYPE(double);
 601 DECLARE_PRIM_TYPE(void);
 602
 603 void
 604 _Jv_InitPrimClass (jclass cl, char *cname, char sig, int len,
 605                    _Jv_ArrayVTable *array_vtable)
 606 {
 607   using namespace java::lang::reflect;
 608
 609   _Jv_InitNewClassFields (cl);
 610
 611   // We must set the vtable for the class; the Java constructor
 612   // doesn't do this.
 613   (*(_Jv_VTable **) cl) = java::lang::Class::class$.vtable;
 614
 615   // Initialize the fields we care about.  We do this in the same
 616   // order they are declared in Class.h.
 617   cl->name = _Jv_makeUtf8Const ((char *) cname, -1);
 618   cl->accflags = Modifier::PUBLIC | Modifier::FINAL | Modifier::ABSTRACT;
 619   cl->method_count = sig;
 620   cl->size_in_bytes = len;
 621   cl->vtable = JV_PRIMITIVE_VTABLE;
 622   cl->state = JV_STATE_DONE;
 623   cl->depth = -1;
 624   if (sig != 'V')
 625     _Jv_NewArrayClass (cl, NULL, (_Jv_VTable *) array_vtable);
 626 }
 627
 628 jclass
 629 _Jv_FindClassFromSignature (char *sig, java::lang::ClassLoader *loader)
 630 {
 631   switch (*sig)
 632     {
 633     case 'B':
 634       return JvPrimClass (byte);
 635     case 'S':
 636       return JvPrimClass (short);
 637     case 'I':
 638       return JvPrimClass (int);
 639     case 'J':
 640       return JvPrimClass (long);
 641     case 'Z':
 642       return JvPrimClass (boolean);
 643     case 'C':
 644       return JvPrimClass (char);
 645     case 'F':
 646       return JvPrimClass (float);
 647     case 'D':
 648       return JvPrimClass (double);
 649     case 'V':
 650       return JvPrimClass (void);
 651     case 'L':
 652       {
 653         int i;
 654         for (i = 1; sig[i] && sig[i] != ';'; ++i)
 655           ;
 656         _Jv_Utf8Const *name = _Jv_makeUtf8Const (&sig[1], i - 1);
 657         return _Jv_FindClass (name, loader);
 658
 659       }
 660     case '[':
 661       {
 662         jclass klass = _Jv_FindClassFromSignature (&sig[1], loader);
 663         if (! klass)
 664           return NULL;
 665         return _Jv_GetArrayClass (klass, loader);
 666       }
 667     }
 668
 669   return NULL;                  // Placate compiler.
 670 }
 671
 672 \f
 673
 674 JArray<jstring> *
 675 JvConvertArgv (int argc, const char **argv)
 676 {
 677   if (argc < 0)
 678     argc = 0;
 679   jobjectArray ar = JvNewObjectArray(argc, &StringClass, NULL);
 680   jobject *ptr = elements(ar);
 681   jbyteArray bytes = NULL;
 682   for (int i = 0;  i < argc;  i++)
 683     {
 684       const char *arg = argv[i];
 685       int len = strlen (arg);
 686       if (bytes == NULL || bytes->length < len)
 687         bytes = JvNewByteArray (len);
 688       jbyte *bytePtr = elements (bytes);
 689       // We assume jbyte == char.
 690       memcpy (bytePtr, arg, len);
 691
 692       // Now convert using the default encoding.
 693       *ptr++ = new java::lang::String (bytes, 0, len);
 694     }
 695   return (JArray<jstring>*) ar;
 696 }
 697
 698 // FIXME: These variables are static so that they will be
 699 // automatically scanned by the Boehm collector.  This is needed
 700 // because with qthreads the collector won't scan the initial stack --
 701 // it will only scan the qthreads stacks.
 702
 703 // Command line arguments.
 704 static JArray<jstring> *arg_vec;
 705
 706 // The primary thread.
 707 static java::lang::Thread *main_thread;
 708
 709 char *
 710 _Jv_ThisExecutable (void)
 711 {
 712   return _Jv_execName;
 713 }
 714
 715 void
 716 _Jv_ThisExecutable (const char *name)
 717 {
 718   if (name)
 719     {
 720       _Jv_execName = (char *) _Jv_Malloc (strlen (name) + 1);
 721       strcpy (_Jv_execName, name);
 722     }
 723 }
 724
 725 #ifndef DISABLE_GETENV_PROPERTIES
 726
 727 static char *
 728 next_property_key (char *s, size_t *length)
 729 {
 730   size_t l = 0;
 731
 732   JvAssert (s);
 733
 734   // Skip over whitespace
 735   while (isspace (*s))
 736     s++;
 737
 738   // If we've reached the end, return NULL.  Also return NULL if for
 739   // some reason we've come across a malformed property string.
 740   if (*s == 0
 741       || *s == ':'
 742       || *s == '=')
 743     return NULL;
 744
 745   // Determine the length of the property key.
 746   while (s[l] != 0
 747          && ! isspace (s[l])
 748          && s[l] != ':'
 749          && s[l] != '=')
 750     {
 751       if (s[l] == '\\'
 752           && s[l+1] != 0)
 753         l++;
 754       l++;
 755     }
 756
 757   *length = l;
 758
 759   return s;
 760 }
 761
 762 static char *
 763 next_property_value (char *s, size_t *length)
 764 {
 765   size_t l = 0;
 766
 767   JvAssert (s);
 768
 769   while (isspace (*s))
 770     s++;
 771
 772   if (*s == ':'
 773       || *s == '=')
 774     s++;
 775
 776   while (isspace (*s))
 777     s++;
 778
 779   // If we've reached the end, return NULL.
 780   if (*s == 0)
 781     return NULL;
 782
 783   // Determine the length of the property value.
 784   while (s[l] != 0
 785          && ! isspace (s[l])
 786          && s[l] != ':'
 787          && s[l] != '=')
 788     {
 789       if (s[l] == '\\'
 790           && s[l+1] != 0)
 791         l += 2;
 792       else
 793         l++;
 794     }
 795
 796   *length = l;
 797
 798   return s;
 799 }
 800
 801 static void
 802 process_gcj_properties ()
 803 {
 804   char *props = getenv("GCJ_PROPERTIES");
 805   char *p = props;
 806   size_t length;
 807   size_t property_count = 0;
 808
 809   if (NULL == props)
 810     return;
 811
 812   // Whip through props quickly in order to count the number of
 813   // property values.
 814   while (p && (p = next_property_key (p, &length)))
 815     {
 816       // Skip to the end of the key
 817       p += length;
 818
 819       p = next_property_value (p, &length);
 820       if (p)
 821         p += length;
 822
 823       property_count++;
 824     }
 825
 826   // Allocate an array of property value/key pairs.
 827   _Jv_Environment_Properties =
 828     (property_pair *) malloc (sizeof(property_pair)
 829                               * (property_count + 1));
 830
 831   // Go through the properties again, initializing _Jv_Properties
 832   // along the way.
 833   p = props;
 834   property_count = 0;
 835   while (p && (p = next_property_key (p, &length)))
 836     {
 837       _Jv_Environment_Properties[property_count].key = p;
 838       _Jv_Environment_Properties[property_count].key_length = length;
 839
 840       // Skip to the end of the key
 841       p += length;
 842
 843       p = next_property_value (p, &length);
 844
 845       _Jv_Environment_Properties[property_count].value = p;
 846       _Jv_Environment_Properties[property_count].value_length = length;
 847
 848       if (p)
 849         p += length;
 850
 851       property_count++;
 852     }
 853   memset ((void *) &_Jv_Environment_Properties[property_count],
 854           0, sizeof (property_pair));
 855   {
 856     size_t i = 0;
 857
 858     // Null terminate the strings.
 859     while (_Jv_Environment_Properties[i].key)
 860       {
 861         _Jv_Environment_Properties[i].key[_Jv_Environment_Properties[i].key_length] = 0;
 862         _Jv_Environment_Properties[i++].value[_Jv_Environment_Properties[i].value_length] = 0;
 863       }
 864   }
 865 }
 866 #endif // DISABLE_GETENV_PROPERTIES
 867
 868 namespace gcj
 869 {
 870   _Jv_Utf8Const *void_signature;
 871   _Jv_Utf8Const *clinit_name;
 872   _Jv_Utf8Const *init_name;
 873   _Jv_Utf8Const *finit_name;
 874
 875   bool runtimeInitialized = false;
 876 }
 877
 878 jint
 879 _Jv_CreateJavaVM (void* /*vm_args*/)
 880 {
 881   using namespace gcj;
 882
 883   if (runtimeInitialized)
 884     return -1;
 885
 886   runtimeInitialized = true;
 887
 888   PROCESS_GCJ_PROPERTIES;
 889
 890   _Jv_InitThreads ();
 891   _Jv_InitGC ();
 892   _Jv_InitializeSyncMutex ();
 893
 894   /* Initialize Utf8 constants declared in jvm.h. */
 895   void_signature = _Jv_makeUtf8Const ("()V", 3);
 896   clinit_name = _Jv_makeUtf8Const ("<clinit>", 8);
 897   init_name = _Jv_makeUtf8Const ("<init>", 6);
 898   finit_name = _Jv_makeUtf8Const ("finit$", 6);
 899
 900   /* Initialize built-in classes to represent primitive TYPEs. */
 901   _Jv_InitPrimClass (&_Jv_byteClass,    "byte",    'B', 1, &_Jv_byteVTable);
 902   _Jv_InitPrimClass (&_Jv_shortClass,   "short",   'S', 2, &_Jv_shortVTable);
 903   _Jv_InitPrimClass (&_Jv_intClass,     "int",     'I', 4, &_Jv_intVTable);
 904   _Jv_InitPrimClass (&_Jv_longClass,    "long",    'J', 8, &_Jv_longVTable);
 905   _Jv_InitPrimClass (&_Jv_booleanClass, "boolean", 'Z', 1, &_Jv_booleanVTable);
 906   _Jv_InitPrimClass (&_Jv_charClass,    "char",    'C', 2, &_Jv_charVTable);
 907   _Jv_InitPrimClass (&_Jv_floatClass,   "float",   'F', 4, &_Jv_floatVTable);
 908   _Jv_InitPrimClass (&_Jv_doubleClass,  "double",  'D', 8, &_Jv_doubleVTable);
 909   _Jv_InitPrimClass (&_Jv_voidClass,    "void",    'V', 0, &_Jv_voidVTable);
 910
 911   // Turn stack trace generation off while creating exception objects.
 912   _Jv_InitClass (&java::lang::Throwable::class$);
 913   java::lang::Throwable::trace_enabled = 0;
 914
 915   INIT_SEGV;
 916 #ifdef HANDLE_FPE
 917   INIT_FPE;
 918 #else
 919   arithexception = new java::lang::ArithmeticException
 920     (JvNewStringLatin1 ("/ by zero"));
 921 #endif
 922
 923   no_memory = new java::lang::OutOfMemoryError;
 924
 925   java::lang::Throwable::trace_enabled = 1;
 926
 927 #ifdef USE_LTDL
 928   LTDL_SET_PRELOADED_SYMBOLS ();
 929 #endif
 930
 931   _Jv_platform_initialize ();
 932
 933   _Jv_JNI_Init ();
 934
 935   _Jv_GCInitializeFinalizers (&::gnu::gcj::runtime::FinalizerThread::finalizerReady);
 936
 937   // Start the GC finalizer thread.  A VirtualMachineError can be
 938   // thrown by the runtime if, say, threads aren't available.  In this
 939   // case finalizers simply won't run.
 940   try
 941     {
 942       using namespace gnu::gcj::runtime;
 943       FinalizerThread *ft = new FinalizerThread ();
 944       ft->start ();
 945     }
 946   catch (java::lang::VirtualMachineError *ignore)
 947     {
 948     }
 949
 950   return 0;
 951 }
 952
 953 void
 954 _Jv_RunMain (jclass klass, const char *name, int argc, const char **argv,
 955              bool is_jar)
 956 {
 957   _Jv_argv = argv;
 958   _Jv_argc = argc;
 959
 960   java::lang::Runtime *runtime = NULL;
 961
 962
 963 #ifdef DISABLE_MAIN_ARGS
 964   _Jv_ThisExecutable ("[Embedded App]");
 965 #else
 966 #ifdef HAVE_PROC_SELF_EXE
 967   char exec_name[20];
 968   sprintf (exec_name, "/proc/%d/exe", getpid ());
 969   _Jv_ThisExecutable (exec_name);
 970 #else
 971   _Jv_ThisExecutable (argv[0]);
 972 #endif /* HAVE_PROC_SELF_EXE */
 973 #endif /* DISABLE_MAIN_ARGS */
 974
 975   try
 976     {
 977       // Set this very early so that it is seen when java.lang.System
 978       // is initialized.
 979       if (is_jar)
 980         _Jv_Jar_Class_Path = strdup (name);
 981       _Jv_CreateJavaVM (NULL);
 982
 983       // Get the Runtime here.  We want to initialize it before searching
 984       // for `main'; that way it will be set up if `main' is a JNI method.
 985       runtime = java::lang::Runtime::getRuntime ();
 986
 987 #ifdef DISABLE_MAIN_ARGS
 988       arg_vec = JvConvertArgv (0, 0);
 989 #else
 990       arg_vec = JvConvertArgv (argc - 1, argv + 1);
 991 #endif
 992
 993       using namespace gnu::gcj::runtime;
 994       if (klass)
 995         main_thread = new FirstThread (klass, arg_vec);
 996       else
 997         main_thread = new FirstThread (JvNewStringLatin1 (name),
 998                                        arg_vec, is_jar);
 999     }
1000   catch (java::lang::Throwable *t)
1001     {
1002       java::lang::System::err->println (JvNewStringLatin1
1003         ("Exception during runtime initialization"));
1004       t->printStackTrace();
1005       runtime->exit (1);
1006     }
1007
1008   _Jv_AttachCurrentThread (main_thread);
1009   _Jv_ThreadRun (main_thread);
1010   _Jv_ThreadWait ();
1011
1012   int status = (int) java::lang::ThreadGroup::had_uncaught_exception;
1013   runtime->exit (status);
1014 }
1015
1016 void
1017 JvRunMain (jclass klass, int argc, const char **argv)
1018 {
1019   _Jv_RunMain (klass, NULL, argc, argv, false);
1020 }
1021
1022 \f
1023
1024 // Parse a string and return a heap size.
1025 static size_t
1026 parse_heap_size (const char *spec)
1027 {
1028   char *end;
1029   unsigned long val = strtoul (spec, &end, 10);
1030   if (*end == 'k' || *end == 'K')
1031     val *= 1024;
1032   else if (*end == 'm' || *end == 'M')
1033     val *= 1048576;
1034   return (size_t) val;
1035 }
1036
1037 // Set the initial heap size.  This might be ignored by the GC layer.
1038 // This must be called before _Jv_RunMain.
1039 void
1040 _Jv_SetInitialHeapSize (const char *arg)
1041 {
1042   size_t size = parse_heap_size (arg);
1043   _Jv_GCSetInitialHeapSize (size);
1044 }
1045
1046 // Set the maximum heap size.  This might be ignored by the GC layer.
1047 // This must be called before _Jv_RunMain.
1048 void
1049 _Jv_SetMaximumHeapSize (const char *arg)
1050 {
1051   size_t size = parse_heap_size (arg);
1052   _Jv_GCSetMaximumHeapSize (size);
1053 }
1054
1055 \f
1056
1057 void *
1058 _Jv_Malloc (jsize size)
1059 {
1060   if (__builtin_expect (size == 0, false))
1061     size = 1;
1062   void *ptr = malloc ((size_t) size);
1063   if (__builtin_expect (ptr == NULL, false))
1064     throw no_memory;
1065   return ptr;
1066 }
1067
1068 void *
1069 _Jv_Realloc (void *ptr, jsize size)
1070 {
1071   if (__builtin_expect (size == 0, false))
1072     size = 1;
1073   ptr = realloc (ptr, (size_t) size);
1074   if (__builtin_expect (ptr == NULL, false))
1075     throw no_memory;
1076   return ptr;
1077 }
1078
1079 void *
1080 _Jv_MallocUnchecked (jsize size)
1081 {
1082   if (__builtin_expect (size == 0, false))
1083     size = 1;
1084   return malloc ((size_t) size);
1085 }
1086
1087 void
1088 _Jv_Free (void* ptr)
1089 {
1090   return free (ptr);
1091 }
1092
1093 \f
1094
1095 // In theory, these routines can be #ifdef'd away on machines which
1096 // support divide overflow signals.  However, we never know if some
1097 // code might have been compiled with "-fuse-divide-subroutine", so we
1098 // always include them in libgcj.
1099
1100 jint
1101 _Jv_divI (jint dividend, jint divisor)
1102 {
1103   if (__builtin_expect (divisor == 0, false))
1104     _Jv_ThrowSignal (arithexception);
1105
1106   if (dividend == (jint) 0x80000000L && divisor == -1)
1107     return dividend;
1108
1109   return dividend / divisor;
1110 }
1111
1112 jint
1113 _Jv_remI (jint dividend, jint divisor)
1114 {
1115   if (__builtin_expect (divisor == 0, false))
1116     _Jv_ThrowSignal (arithexception);
1117
1118   if (dividend == (jint) 0x80000000L && divisor == -1)
1119     return 0;
1120
1121   return dividend % divisor;
1122 }
1123
1124 jlong
1125 _Jv_divJ (jlong dividend, jlong divisor)
1126 {
1127   if (__builtin_expect (divisor == 0, false))
1128     _Jv_ThrowSignal (arithexception);
1129
1130   if (dividend == (jlong) 0x8000000000000000LL && divisor == -1)
1131     return dividend;
1132
1133   return dividend / divisor;
1134 }
1135
1136 jlong
1137 _Jv_remJ (jlong dividend, jlong divisor)
1138 {
1139   if (__builtin_expect (divisor == 0, false))
1140     _Jv_ThrowSignal (arithexception);
1141
1142   if (dividend == (jlong) 0x8000000000000000LL && divisor == -1)
1143     return 0;
1144
1145   return dividend % divisor;
1146 }