libjava/java/lang/reflect/natMethod.cc

   1 // natMethod.cc - Native code for Method class.
   2
   3 /* Copyright (C) 1998, 1999, 2000, 2001 , 2002, 2003, 2004, 2005, 2006 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
  13 #include <gcj/cni.h>
  14 #include <jvm.h>
  15 #include <jni.h>
  16 #include <java-stack.h>
  17
  18 #include <java/lang/reflect/Method.h>
  19 #include <java/lang/reflect/Constructor.h>
  20 #include <java/lang/reflect/InvocationTargetException.h>
  21 #include <java/lang/reflect/Modifier.h>
  22
  23 #include <java/lang/Void.h>
  24 #include <java/lang/Byte.h>
  25 #include <java/lang/Boolean.h>
  26 #include <java/lang/Character.h>
  27 #include <java/lang/Short.h>
  28 #include <java/lang/Integer.h>
  29 #include <java/lang/Long.h>
  30 #include <java/lang/Float.h>
  31 #include <java/lang/Double.h>
  32 #include <java/lang/IllegalAccessException.h>
  33 #include <java/lang/IllegalArgumentException.h>
  34 #include <java/lang/IncompatibleClassChangeError.h>
  35 #include <java/lang/NullPointerException.h>
  36 #include <java/lang/ArrayIndexOutOfBoundsException.h>
  37 #include <java/lang/VirtualMachineError.h>
  38 #include <java/lang/Class.h>
  39 #include <gcj/method.h>
  40 #include <gnu/gcj/RawData.h>
  41 #include <java/lang/NoClassDefFoundError.h>
  42
  43 #include <stdlib.h>
  44
  45 #if USE_LIBFFI
  46 #include <ffi.h>
  47 #else
  48 #include <java/lang/UnsupportedOperationException.h>
  49 #endif
  50
  51 struct cpair
  52 {
  53   jclass prim;
  54   jclass wrap;
  55 };
  56
  57 // This is used to determine when a primitive widening conversion is
  58 // allowed.
  59 static cpair primitives[] =
  60 {
  61 #define BOOLEAN 0
  62   { JvPrimClass (boolean), &java::lang::Boolean::class$ },
  63   { JvPrimClass (byte), &java::lang::Byte::class$ },
  64 #define SHORT 2
  65   { JvPrimClass (short), &java::lang::Short::class$ },
  66 #define CHAR 3
  67   { JvPrimClass (char), &java::lang::Character::class$ },
  68   { JvPrimClass (int), &java::lang::Integer::class$ },
  69   { JvPrimClass (long), &java::lang::Long::class$ },
  70   { JvPrimClass (float), &java::lang::Float::class$ },
  71   { JvPrimClass (double), &java::lang::Double::class$ },
  72   { NULL, NULL }
  73 };
  74
  75 static inline jboolean
  76 can_widen (jclass from, jclass to)
  77 {
  78   int fromx = -1, tox = -1;
  79
  80   for (int i = 0; primitives[i].prim; ++i)
  81     {
  82       if (primitives[i].wrap == from)
  83         fromx = i;
  84       if (primitives[i].prim == to)
  85         tox = i;
  86     }
  87
  88   // Can't handle a miss.
  89   if (fromx == -1 || tox == -1)
  90     return false;
  91   // Boolean arguments may not be widened.
  92   if (fromx == BOOLEAN && tox != BOOLEAN)
  93     return false;
  94   // Nothing promotes to char.
  95   if (tox == CHAR && fromx != CHAR)
  96     return false;
  97
  98   return fromx <= tox;
  99 }
 100
 101 #ifdef USE_LIBFFI
 102 static inline ffi_type *
 103 get_ffi_type (jclass klass)
 104 {
 105   // A special case.
 106   if (klass == NULL)
 107     return &ffi_type_pointer;
 108
 109   ffi_type *r;
 110   if (klass == JvPrimClass (byte))
 111     r = &ffi_type_sint8;
 112   else if (klass == JvPrimClass (short))
 113     r = &ffi_type_sint16;
 114   else if (klass == JvPrimClass (int))
 115     r = &ffi_type_sint32;
 116   else if (klass == JvPrimClass (long))
 117     r = &ffi_type_sint64;
 118   else if (klass == JvPrimClass (float))
 119     r = &ffi_type_float;
 120   else if (klass == JvPrimClass (double))
 121     r = &ffi_type_double;
 122   else if (klass == JvPrimClass (boolean))
 123     {
 124       // On some platforms a bool is a byte, on others an int.
 125       if (sizeof (jboolean) == sizeof (jbyte))
 126         r = &ffi_type_sint8;
 127       else
 128         {
 129           JvAssert (sizeof (jboolean) == sizeof (jint));
 130           r = &ffi_type_sint32;
 131         }
 132     }
 133   else if (klass == JvPrimClass (char))
 134     r = &ffi_type_uint16;
 135   else
 136     {
 137       JvAssert (! klass->isPrimitive());
 138       r = &ffi_type_pointer;
 139     }
 140
 141   return r;
 142 }
 143 #endif // USE_LIBFFI
 144
 145 jobject
 146 java::lang::reflect::Method::invoke (jobject obj, jobjectArray args)
 147 {
 148   using namespace java::lang::reflect;
 149   jclass iface = NULL;
 150
 151   if (parameter_types == NULL)
 152     getType ();
 153
 154   jmethodID meth = _Jv_FromReflectedMethod (this);
 155
 156   if (Modifier::isStatic(meth->accflags))
 157     {
 158       // We have to initialize a static class.  It is safe to do this
 159       // here and not in _Jv_CallAnyMethodA because JNI initializes a
 160       // class whenever a method lookup is done.
 161       _Jv_InitClass (declaringClass);
 162     }
 163   else
 164     {
 165       jclass objClass = JV_CLASS (obj);
 166       if (! _Jv_IsAssignableFrom (objClass, declaringClass))
 167         throw new java::lang::IllegalArgumentException;
 168     }
 169
 170   // Check accessibility, if required.
 171   if (! (Modifier::isPublic (meth->accflags) || this->isAccessible()))
 172     {
 173       Class *caller = _Jv_StackTrace::GetCallingClass (&Method::class$);
 174       if (! _Jv_CheckAccess(caller, declaringClass, meth->accflags))
 175         throw new IllegalAccessException;
 176     }
 177
 178   if (declaringClass->isInterface())
 179     iface = declaringClass;
 180
 181   return _Jv_CallAnyMethodA (obj, return_type, meth, false,
 182                              parameter_types, args, iface);
 183 }
 184
 185 jint
 186 java::lang::reflect::Method::getModifiersInternal ()
 187 {
 188   return _Jv_FromReflectedMethod (this)->accflags;
 189 }
 190
 191 jstring
 192 java::lang::reflect::Method::getName ()
 193 {
 194   if (name == NULL)
 195     name = _Jv_NewStringUtf8Const (_Jv_FromReflectedMethod (this)->name);
 196   return name;
 197 }
 198
 199 /* Internal method to set return_type and parameter_types fields. */
 200
 201 void
 202 java::lang::reflect::Method::getType ()
 203 {
 204   _Jv_Method *method = _Jv_FromReflectedMethod (this);
 205   _Jv_GetTypesFromSignature (method,
 206                              declaringClass,
 207                              &parameter_types,
 208                              &return_type);
 209
 210   int count = 0;
 211   if (method->throws != NULL)
 212     {
 213       while (method->throws[count] != NULL)
 214         ++count;
 215     }
 216
 217   exception_types
 218     = (JArray<jclass> *) JvNewObjectArray (count, &java::lang::Class::class$,
 219                                            NULL);
 220   jclass *elts = elements (exception_types);
 221   for (int i = 0; i < count; ++i)
 222     elts[i] = _Jv_FindClass (method->throws[i],
 223                              declaringClass->getClassLoaderInternal ());
 224 }
 225
 226 void
 227 _Jv_GetTypesFromSignature (jmethodID method,
 228                            jclass declaringClass,
 229                            JArray<jclass> **arg_types_out,
 230                            jclass *return_type_out)
 231 {
 232
 233   _Jv_Utf8Const* sig = method->signature;
 234   java::lang::ClassLoader *loader = declaringClass->getClassLoaderInternal();
 235   char *ptr = sig->chars();
 236   int numArgs = 0;
 237   /* First just count the number of parameters. */
 238   // FIXME: should do some validation here, e.g., that there is only
 239   // one return type.
 240   for (; ; ptr++)
 241     {
 242       switch (*ptr)
 243         {
 244         case 0:
 245         case ')':
 246         case 'V':
 247           break;
 248         case '[':
 249         case '(':
 250           continue;
 251         case 'B':
 252         case 'C':
 253         case 'D':
 254         case 'F':
 255         case 'S':
 256         case 'I':
 257         case 'J':
 258         case 'Z':
 259           numArgs++;
 260           continue;
 261         case 'L':
 262           numArgs++;
 263           do
 264             ptr++;
 265           while (*ptr != ';' && ptr[1] != '\0');
 266           continue;
 267         }
 268       break;
 269     }
 270
 271   JArray<jclass> *args = (JArray<jclass> *)
 272     JvNewObjectArray (numArgs, &java::lang::Class::class$, NULL);
 273   jclass* argPtr = elements (args);
 274   for (ptr = sig->chars(); *ptr != '\0'; ptr++)
 275     {
 276       if (*ptr == '(')
 277         continue;
 278       if (*ptr == ')')
 279         {
 280           argPtr = return_type_out;
 281           continue;
 282         }
 283
 284       char *end_ptr;
 285       jclass type = _Jv_FindClassFromSignature (ptr, loader, &end_ptr);
 286       if (type == NULL)
 287         // FIXME: This isn't ideal.
 288         throw new java::lang::NoClassDefFoundError (sig->toString());
 289
 290       // ARGPTR can be NULL if we are processing the return value of a
 291       // call from Constructor.
 292       if (argPtr)
 293         *argPtr++ = type;
 294
 295       ptr = end_ptr;
 296     }
 297   *arg_types_out = args;
 298 }
 299
 300 // This is a very rough analog of the JNI CallNonvirtual<type>MethodA
 301 // functions.  It handles both Methods and Constructors, and it can
 302 // handle any return type.  In the Constructor case, the `obj'
 303 // argument is unused and should be NULL; also, the `return_type' is
 304 // the class that the constructor will construct.  RESULT is a pointer
 305 // to a `jvalue' (see jni.h); for a void method this should be NULL.
 306 // This function returns an exception (if one was thrown), or NULL if
 307 // the call went ok.
 308 void
 309 _Jv_CallAnyMethodA (jobject obj,
 310                     jclass return_type,
 311                     jmethodID meth,
 312                     jboolean is_constructor,
 313                     jboolean is_virtual_call,
 314                     JArray<jclass> *parameter_types,
 315                     jvalue *args,
 316                     jvalue *result,
 317                     jboolean is_jni_call,
 318                     jclass iface)
 319 {
 320   using namespace java::lang::reflect;
 321
 322 #ifdef USE_LIBFFI
 323   JvAssert (! is_constructor || ! obj);
 324   JvAssert (! is_constructor || return_type);
 325
 326   // See whether call needs an object as the first argument.  A
 327   // constructor does need a `this' argument, but it is one we create.
 328   jboolean needs_this = false;
 329   if (is_constructor
 330       || ! Modifier::isStatic(meth->accflags))
 331     needs_this = true;
 332
 333   int param_count = parameter_types->length;
 334   if (needs_this)
 335     ++param_count;
 336
 337   ffi_type *rtype;
 338   // A constructor itself always returns void.
 339   if (is_constructor || return_type == JvPrimClass (void))
 340     rtype = &ffi_type_void;
 341   else
 342     rtype = get_ffi_type (return_type);
 343   ffi_type **argtypes = (ffi_type **) __builtin_alloca (param_count
 344                                                         * sizeof (ffi_type *));
 345
 346   jclass *paramelts = elements (parameter_types);
 347
 348   // Special case for the `this' argument of a constructor.  Note that
 349   // the JDK 1.2 docs specify that the new object must be allocated
 350   // before argument conversions are done.
 351   if (is_constructor)
 352     obj = _Jv_AllocObject (return_type);
 353
 354   const int size_per_arg = sizeof(jvalue);
 355   ffi_cif cif;
 356
 357   char *p = (char *) __builtin_alloca (param_count * size_per_arg);
 358                 // Overallocate to get correct alignment.
 359   void **values = (void **)
 360                         __builtin_alloca (param_count * sizeof (void *));
 361
 362   int i = 0;
 363   if (needs_this)
 364     {
 365       // The `NULL' type is `Object'.
 366       argtypes[i] = get_ffi_type (NULL);
 367       values[i] = p;
 368       memcpy (p, &obj, sizeof (jobject));
 369       p += size_per_arg;
 370       ++i;
 371     }
 372
 373   for (int arg = 0; i < param_count; ++i, ++arg)
 374     {
 375       int tsize;
 376
 377       argtypes[i] = get_ffi_type (paramelts[arg]);
 378       if (paramelts[arg]->isPrimitive())
 379         tsize = paramelts[arg]->size();
 380       else
 381         tsize = sizeof (jobject);
 382
 383       // Copy appropriate bits from the jvalue into the ffi array.
 384       // FIXME: we could do this copying all in one loop, above, by
 385       // over-allocating a bit.
 386       // How do we do this without breaking big-endian platforms?
 387       values[i] = p;
 388       memcpy (p, &args[arg], tsize);
 389       p += size_per_arg;
 390     }
 391
 392   if (ffi_prep_cif (&cif, FFI_DEFAULT_ABI, param_count,
 393                     rtype, argtypes) != FFI_OK)
 394     throw new java::lang::VirtualMachineError(JvNewStringLatin1("internal error: ffi_prep_cif failed"));
 395
 396   using namespace java::lang;
 397   using namespace java::lang::reflect;
 398
 399   union
 400   {
 401     ffi_arg i;
 402     jobject o;
 403     jlong l;
 404     jfloat f;
 405     jdouble d;
 406   } ffi_result;
 407
 408   switch (rtype->type)
 409     {
 410     case FFI_TYPE_VOID:
 411       break;
 412     case FFI_TYPE_SINT8:
 413       result->b = 0;
 414       break;
 415     case FFI_TYPE_SINT16:
 416       result->s = 0;
 417       break;
 418     case FFI_TYPE_UINT16:
 419       result->c = 0;
 420       break;
 421     case FFI_TYPE_SINT32:
 422       result->i = 0;
 423       break;
 424     case FFI_TYPE_SINT64:
 425       result->j = 0;
 426       break;
 427     case FFI_TYPE_FLOAT:
 428       result->f = 0;
 429       break;
 430     case FFI_TYPE_DOUBLE:
 431       result->d = 0;
 432       break;
 433     case FFI_TYPE_POINTER:
 434       result->l = 0;
 435       break;
 436     default:
 437       JvFail ("Unknown ffi_call return type");
 438       break;
 439     }
 440
 441   void *ncode;
 442
 443   // FIXME: If a vtable index is -1 at this point it is invalid, so we
 444   // have to use the ncode.
 445   //
 446   // This can happen because methods in final classes don't have
 447   // vtable entries, but _Jv_isVirtualMethod() doesn't know that.  We
 448   // could solve this problem by allocating a vtable index for methods
 449   // in final classes.
 450   if (is_virtual_call
 451       && ! Modifier::isFinal (meth->accflags)
 452       && (_Jv_ushort)-1 != meth->index)
 453     {
 454       _Jv_VTable *vtable = *(_Jv_VTable **) obj;
 455       if (iface == NULL)
 456         {
 457           if (is_jni_call && Modifier::isAbstract (meth->accflags))
 458             {
 459               // With JNI we don't know if this is an interface call
 460               // or a call to an abstract method.  Look up the method
 461               // by name, the slow way.
 462               _Jv_Method *concrete_meth
 463                 = _Jv_LookupDeclaredMethod (vtable->clas,
 464                                             meth->name,
 465                                             meth->signature,
 466                                             NULL);
 467               if (concrete_meth == NULL
 468                   || concrete_meth->ncode == NULL
 469                   || Modifier::isAbstract(concrete_meth->accflags))
 470                 throw new java::lang::IncompatibleClassChangeError
 471                   (_Jv_GetMethodString (vtable->clas, meth));
 472               ncode = concrete_meth->ncode;
 473             }
 474           else
 475             ncode = vtable->get_method (meth->index);
 476         }
 477       else
 478         ncode = _Jv_LookupInterfaceMethodIdx (vtable->clas, iface,
 479                                               meth->index);
 480     }
 481   else
 482     {
 483       ncode = meth->ncode;
 484     }
 485
 486   try
 487     {
 488       ffi_call (&cif, (void (*)()) ncode, &ffi_result, values);
 489     }
 490   catch (Throwable *ex)
 491     {
 492       // For JNI we just throw the real error.  For reflection, we
 493       // wrap the underlying method's exception in an
 494       // InvocationTargetException.
 495       if (! is_jni_call)
 496         ex = new InvocationTargetException (ex);
 497       throw ex;
 498     }
 499
 500   // Since ffi_call returns integer values promoted to a word, use
 501   // a narrowing conversion for jbyte, jchar, etc. results.
 502   // Note that boolean is handled either by the FFI_TYPE_SINT8 or
 503   // FFI_TYPE_SINT32 case.
 504   if (is_constructor)
 505     result->l = obj;
 506   else
 507     {
 508       switch (rtype->type)
 509         {
 510         case FFI_TYPE_VOID:
 511           break;
 512         case FFI_TYPE_SINT8:
 513           result->b = (jbyte)ffi_result.i;
 514           break;
 515         case FFI_TYPE_SINT16:
 516           result->s = (jshort)ffi_result.i;
 517           break;
 518         case FFI_TYPE_UINT16:
 519           result->c = (jchar)ffi_result.i;
 520           break;
 521         case FFI_TYPE_SINT32:
 522           result->i = (jint)ffi_result.i;
 523           break;
 524         case FFI_TYPE_SINT64:
 525           result->j = (jlong)ffi_result.l;
 526           break;
 527         case FFI_TYPE_FLOAT:
 528           result->f = (jfloat)ffi_result.f;
 529           break;
 530         case FFI_TYPE_DOUBLE:
 531           result->d = (jdouble)ffi_result.d;
 532           break;
 533         case FFI_TYPE_POINTER:
 534           result->l = (jobject)ffi_result.o;
 535           break;
 536         default:
 537           JvFail ("Unknown ffi_call return type");
 538           break;
 539         }
 540     }
 541 #else
 542   throw new java::lang::UnsupportedOperationException(JvNewStringLatin1("reflection not available in this build"));
 543 #endif // USE_LIBFFI
 544 }
 545
 546 // This is another version of _Jv_CallAnyMethodA, but this one does
 547 // more checking and is used by the reflection (and not JNI) code.
 548 jobject
 549 _Jv_CallAnyMethodA (jobject obj,
 550                     jclass return_type,
 551                     jmethodID meth,
 552                     jboolean is_constructor,
 553                     JArray<jclass> *parameter_types,
 554                     jobjectArray args,
 555                     jclass iface)
 556 {
 557   if (parameter_types->length == 0 && args == NULL)
 558     {
 559       // The JDK accepts this, so we do too.
 560     }
 561   else if (parameter_types->length != args->length)
 562     throw new java::lang::IllegalArgumentException;
 563
 564   int param_count = parameter_types->length;
 565
 566   jclass *paramelts = elements (parameter_types);
 567   jobject *argelts = args == NULL ? NULL : elements (args);
 568   jvalue argvals[param_count];
 569
 570 #define COPY(Where, What, Type) \
 571   do { \
 572     Type val = (What); \
 573     memcpy ((Where), &val, sizeof (Type)); \
 574   } while (0)
 575
 576   for (int i = 0; i < param_count; ++i)
 577     {
 578       jclass k = argelts[i] ? argelts[i]->getClass() : NULL;
 579       if (paramelts[i]->isPrimitive())
 580         {
 581           if (! argelts[i]
 582               || ! k
 583               || ! can_widen (k, paramelts[i]))
 584             throw new java::lang::IllegalArgumentException;
 585
 586           if (paramelts[i] == JvPrimClass (boolean))
 587             COPY (&argvals[i],
 588                   ((java::lang::Boolean *) argelts[i])->booleanValue(),
 589                   jboolean);
 590           else if (paramelts[i] == JvPrimClass (char))
 591             COPY (&argvals[i],
 592                   ((java::lang::Character *) argelts[i])->charValue(),
 593                   jchar);
 594           else
 595             {
 596               java::lang::Number *num = (java::lang::Number *) argelts[i];
 597               if (paramelts[i] == JvPrimClass (byte))
 598                 COPY (&argvals[i], num->byteValue(), jbyte);
 599               else if (paramelts[i] == JvPrimClass (short))
 600                 COPY (&argvals[i], num->shortValue(), jshort);
 601               else if (paramelts[i] == JvPrimClass (int))
 602                 COPY (&argvals[i], num->intValue(), jint);
 603               else if (paramelts[i] == JvPrimClass (long))
 604                 COPY (&argvals[i], num->longValue(), jlong);
 605               else if (paramelts[i] == JvPrimClass (float))
 606                 COPY (&argvals[i], num->floatValue(), jfloat);
 607               else if (paramelts[i] == JvPrimClass (double))
 608                 COPY (&argvals[i], num->doubleValue(), jdouble);
 609             }
 610         }
 611       else
 612         {
 613           if (argelts[i] && ! paramelts[i]->isAssignableFrom (k))
 614             throw new java::lang::IllegalArgumentException;
 615           COPY (&argvals[i], argelts[i], jobject);
 616         }
 617     }
 618
 619   jvalue ret_value;
 620   _Jv_CallAnyMethodA (obj, return_type, meth, is_constructor,
 621                       _Jv_isVirtualMethod (meth),
 622                       parameter_types, argvals, &ret_value,
 623                       false, iface);
 624
 625   jobject r;
 626 #define VAL(Wrapper, Field)  (new Wrapper (ret_value.Field))
 627   if (is_constructor)
 628     r = ret_value.l;
 629   else  if (return_type == JvPrimClass (byte))
 630     r = VAL (java::lang::Byte, b);
 631   else if (return_type == JvPrimClass (short))
 632     r = VAL (java::lang::Short, s);
 633   else if (return_type == JvPrimClass (int))
 634     r = VAL (java::lang::Integer, i);
 635   else if (return_type == JvPrimClass (long))
 636     r = VAL (java::lang::Long, j);
 637   else if (return_type == JvPrimClass (float))
 638     r = VAL (java::lang::Float, f);
 639   else if (return_type == JvPrimClass (double))
 640     r = VAL (java::lang::Double, d);
 641   else if (return_type == JvPrimClass (boolean))
 642     r = VAL (java::lang::Boolean, z);
 643   else if (return_type == JvPrimClass (char))
 644     r = VAL (java::lang::Character, c);
 645   else if (return_type == JvPrimClass (void))
 646     r = NULL;
 647   else
 648     {
 649       JvAssert (return_type == NULL || ! return_type->isPrimitive());
 650       r = ret_value.l;
 651     }
 652
 653   return r;
 654 }