gcc/java/verify-glue.c

   1 /* Glue to interface gcj with bytecode verifier.
   2    Copyright (C) 2003, 2004, 2005 Free Software Foundation, Inc.
   3
   4 This file is part of GCC.
   5
   6 GCC is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 GCC is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GCC; see the file COPYING.  If not, write to
  18 the Free Software Foundation, 51 Franklin Street, Fifth Floor,
  19 Boston, MA 02110-1301, USA.
  20
  21 Java and all Java-based marks are trademarks or registered trademarks
  22 of Sun Microsystems, Inc. in the United States and other countries.
  23 The Free Software Foundation is independent of Sun Microsystems, Inc.  */
  24
  25 /* Written by Tom Tromey <tromey@redhat.com>.  */
  26
  27 #include "config.h"
  28
  29 #include "system.h"
  30 #include "coretypes.h"
  31 #include "tm.h"
  32 #include "tree.h"
  33 #include "parse.h"
  34
  35 #include "verify.h"
  36 #include "java-tree.h"
  37 #include "java-except.h"
  38 #include "toplev.h"
  39
  40 void *
  41 vfy_alloc (size_t bytes)
  42 {
  43   return xmalloc (bytes);
  44 }
  45
  46 void
  47 vfy_free (void *mem)
  48 {
  49   free (mem);
  50 }
  51
  52 bool
  53 vfy_strings_equal (vfy_string one, vfy_string two)
  54 {
  55   return one == two;
  56 }
  57
  58 const char *
  59 vfy_string_bytes (vfy_string str)
  60 {
  61   return IDENTIFIER_POINTER (str);
  62 }
  63
  64 int
  65 vfy_string_length (vfy_string str)
  66 {
  67   return IDENTIFIER_LENGTH (str);
  68 }
  69
  70 vfy_string
  71 vfy_init_name (void)
  72 {
  73   return init_identifier_node;
  74 }
  75
  76 vfy_string
  77 vfy_clinit_name (void)
  78 {
  79   return clinit_identifier_node;
  80 }
  81
  82 static const char*
  83 skip_one_type (const char* ptr)
  84 {
  85   int ch = *ptr++;
  86
  87   while (ch == '[')
  88     {
  89       ch = *ptr++;
  90     }
  91
  92   if (ch == 'L')
  93     {
  94       do { ch = *ptr++; } while (ch != ';');
  95     }
  96
  97   return ptr;
  98 }
  99
 100 int
 101 vfy_count_arguments (vfy_string signature)
 102 {
 103   const char *ptr = IDENTIFIER_POINTER (signature);
 104   int arg_count = 0;
 105
 106   /* Skip '('.  */
 107   ptr++;
 108
 109   /* Count args.  */
 110   while (*ptr != ')')
 111     {
 112       ptr = skip_one_type (ptr);
 113       arg_count += 1;
 114     }
 115
 116   return arg_count;
 117 }
 118
 119 vfy_string
 120 vfy_get_string (const char *s, int len)
 121 {
 122   return get_identifier_with_length (s, len);
 123 }
 124
 125 vfy_string
 126 vfy_get_signature (vfy_method *method)
 127 {
 128   return method->signature;
 129 }
 130
 131 vfy_string
 132 vfy_get_method_name (vfy_method *method)
 133 {
 134   return method->name;
 135 }
 136
 137 bool
 138 vfy_is_static (vfy_method *method)
 139 {
 140   return METHOD_STATIC (method->method);
 141 }
 142
 143 const unsigned char *
 144 vfy_get_bytecode (vfy_method *method)
 145 {
 146   return method->bytes;
 147 }
 148
 149 vfy_exception *
 150 vfy_get_exceptions (vfy_method *method)
 151 {
 152   return method->exceptions;
 153 }
 154
 155 void
 156 vfy_get_exception (vfy_exception *exceptions, int index, int *handler,
 157                    int *start, int *end, int *handler_type)
 158 {
 159   *handler = exceptions[index].handler;
 160   *start = exceptions[index].start;
 161   *end = exceptions[index].end;
 162   *handler_type = exceptions[index].type;
 163 }
 164
 165 int
 166 vfy_tag (vfy_constants *pool, int index)
 167 {
 168   int result = JPOOL_TAG (pool, index);
 169   /* gcj will resolve constant pool entries other than string and
 170      class references.  The verifier doesn't care about the values, so
 171      we just strip off the resolved flag.  */
 172   if ((result & CONSTANT_ResolvedFlag) != 0
 173       && result != CONSTANT_ResolvedString
 174       && result != CONSTANT_ResolvedClass)
 175     result &= ~ CONSTANT_ResolvedFlag;
 176   return result;
 177 }
 178
 179 void
 180 vfy_load_indexes (vfy_constants *pool, int index,
 181                   vfy_uint_16 *index0, vfy_uint_16 *index1)
 182 {
 183   *index0 = JPOOL_USHORT1 (pool, index);
 184   *index1 = JPOOL_USHORT2 (pool, index);
 185 }
 186
 187 vfy_constants *
 188 vfy_get_constants (vfy_jclass klass)
 189 {
 190   return TYPE_JCF (klass);
 191 }
 192
 193 int
 194 vfy_get_constants_size (vfy_jclass klass)
 195 {
 196   return JPOOL_SIZE (TYPE_JCF (klass));
 197 }
 198
 199 vfy_string
 200 vfy_get_pool_string (vfy_constants *pool, int index)
 201 {
 202   return get_name_constant (pool, index);
 203 }
 204
 205 vfy_jclass
 206 vfy_get_pool_class (vfy_constants *pool, int index)
 207 {
 208   vfy_jclass k;
 209   k = get_class_constant (pool, index);
 210   return k;
 211 }
 212
 213 vfy_string
 214 vfy_make_string (const char *s, int len)
 215 {
 216   tree result;
 217   char *s2 = (char *) s;
 218   char save = s2[len];
 219   s2[len] = '\0';
 220   result = get_identifier (s2);
 221   s2[len] = save;
 222   return result;
 223 }
 224
 225 vfy_string
 226 vfy_get_class_name (vfy_jclass klass)
 227 {
 228   return DECL_NAME (TYPE_NAME (klass));
 229 }
 230
 231 bool
 232 vfy_is_assignable_from (vfy_jclass target, vfy_jclass source)
 233 {
 234   /* Any class is always assignable to itself, or java.lang.Object. */
 235   if (source == target || target == object_type_node)
 236     return true;
 237
 238   /* For the C++ ABI, perform this test statically. */
 239   if (! flag_indirect_dispatch)
 240     return can_widen_reference_to (source, target);
 241
 242   /* For the BC-ABI, we assume at compile time that reference types are always
 243   compatible.  However, a type assertion table entry is emitted so that the
 244   runtime can detect binary-incompatible changes.  */
 245
 246   add_type_assertion (current_class, JV_ASSERT_TYPES_COMPATIBLE, source,
 247                       target);
 248   return true;
 249 }
 250
 251 char
 252 vfy_get_primitive_char (vfy_jclass klass)
 253 {
 254   tree sig;
 255   if (! vfy_is_primitive (klass))
 256     abort ();
 257   sig = build_java_signature (klass);
 258   return (IDENTIFIER_POINTER (sig))[0];
 259 }
 260
 261 bool
 262 vfy_is_array (vfy_jclass klass)
 263 {
 264   return TYPE_ARRAY_P (klass);
 265 }
 266
 267 bool
 268 vfy_is_interface (vfy_jclass klass)
 269 {
 270   return CLASS_INTERFACE (TYPE_NAME (klass));
 271 }
 272
 273 bool
 274 vfy_is_primitive (vfy_jclass klass)
 275 {
 276   return JPRIMITIVE_TYPE_P (klass);
 277 }
 278
 279 vfy_jclass
 280 vfy_get_superclass (vfy_jclass klass)
 281 {
 282   vfy_jclass k;
 283   k = CLASSTYPE_SUPER (klass);
 284   return k;
 285 }
 286
 287 vfy_jclass
 288 vfy_get_array_class (vfy_jclass klass)
 289 {
 290   vfy_jclass k;
 291   k = build_java_array_type (klass, -1);
 292   return k;
 293 }
 294
 295 vfy_jclass
 296 vfy_get_component_type (vfy_jclass klass)
 297 {
 298   vfy_jclass k;
 299   if (! vfy_is_array (klass))
 300     abort ();
 301   k = TYPE_ARRAY_ELEMENT (klass);
 302   if (TREE_CODE (k) == POINTER_TYPE)
 303     k = TREE_TYPE (k);
 304   return k;
 305 }
 306
 307 bool
 308 vfy_is_abstract (vfy_jclass klass)
 309 {
 310   return CLASS_ABSTRACT (TYPE_NAME (klass));
 311 }
 312
 313 vfy_jclass
 314 vfy_find_class (vfy_jclass ignore ATTRIBUTE_UNUSED, vfy_string name)
 315 {
 316   vfy_jclass k;
 317
 318   k = get_type_from_signature (name);
 319   if (TREE_CODE (k) == POINTER_TYPE)
 320     k = TREE_TYPE (k);
 321
 322   return k;
 323 }
 324
 325 vfy_jclass
 326 vfy_object_type (void)
 327 {
 328   vfy_jclass k;
 329   k = object_type_node;
 330   return k;
 331 }
 332
 333 vfy_jclass
 334 vfy_string_type (void)
 335 {
 336   vfy_jclass k;
 337   k = string_type_node;
 338   return k;
 339 }
 340
 341 vfy_jclass
 342 vfy_throwable_type (void)
 343 {
 344   vfy_jclass k;
 345   k = throwable_type_node;
 346   return k;
 347 }
 348
 349 vfy_jclass
 350 vfy_unsuitable_type (void)
 351 {
 352   return TYPE_SECOND;
 353 }
 354
 355 vfy_jclass
 356 vfy_return_address_type (void)
 357 {
 358   return TYPE_RETURN_ADDR;
 359 }
 360
 361 vfy_jclass
 362 vfy_null_type (void)
 363 {
 364   return TYPE_NULL;
 365 }
 366
 367 bool
 368 vfy_class_has_field (vfy_jclass klass, vfy_string name,
 369                      vfy_string signature)
 370 {
 371   tree field = TYPE_FIELDS (klass);
 372   while (field != NULL_TREE)
 373     {
 374       if (DECL_NAME (field) == name
 375           && build_java_signature (TREE_TYPE (field)) == signature)
 376         return true;
 377       field = TREE_CHAIN (field);
 378     }
 379   return false;
 380 }
 381
 382 int
 383 vfy_fail (const char *message, int pc, vfy_jclass ignore1 ATTRIBUTE_UNUSED,
 384           vfy_method *ignore2 ATTRIBUTE_UNUSED)
 385 {
 386   if (pc == -1)
 387     error ("verification failed: %s", message);
 388   else
 389     error ("verification failed at PC=%d: %s", pc, message);
 390   /* We have to return a value for the verifier to throw.  */
 391   return 1;
 392 }
 393
 394 vfy_jclass
 395 vfy_get_primitive_type (int type)
 396 {
 397   vfy_jclass k;
 398   k = decode_newarray_type (type);
 399   return k;
 400 }
 401
 402 void
 403 vfy_note_stack_depth (vfy_method *method, int pc, int depth)
 404 {
 405   tree label = lookup_label (pc);
 406   LABEL_TYPE_STATE (label) = make_tree_vec (method->max_locals + depth);
 407 }
 408
 409 void
 410 vfy_note_stack_type (vfy_method *method, int pc, int slot, vfy_jclass type)
 411 {
 412   tree label, vec;
 413
 414   slot += method->max_locals;
 415
 416   if (type == object_type_node)
 417     type = object_ptr_type_node;
 418
 419   label = lookup_label (pc);
 420   vec = LABEL_TYPE_STATE (label);
 421   TREE_VEC_ELT (vec, slot) = type;
 422 }
 423
 424 void
 425 vfy_note_local_type (vfy_method *method ATTRIBUTE_UNUSED, int pc, int slot,
 426                      vfy_jclass type)
 427 {
 428   tree label, vec;
 429
 430   if (type == object_type_node)
 431     type = object_ptr_type_node;
 432
 433   label = lookup_label (pc);
 434   vec = LABEL_TYPE_STATE (label);
 435   TREE_VEC_ELT (vec, slot) = type;
 436 }
 437
 438 void
 439 vfy_note_instruction_seen (int pc)
 440 {
 441   instruction_bits[pc] |= BCODE_VERIFIED;
 442 }
 443
 444 /* Verify the bytecodes of the current method.
 445    Return 1 on success, 0 on failure. */
 446 int
 447 verify_jvm_instructions_new (JCF *jcf, const unsigned char *byte_ops,
 448                          long length)
 449 {
 450   vfy_method method;
 451   int i, result, eh_count;
 452   vfy_exception *exceptions;
 453
 454   method_init_exceptions ();
 455
 456   JCF_SEEK (jcf, DECL_CODE_OFFSET (current_function_decl) + length);
 457   eh_count = JCF_readu2 (jcf);
 458
 459   exceptions = (vfy_exception *) xmalloc (eh_count * sizeof (vfy_exception));
 460   for (i = 0; i < eh_count; ++i)
 461     {
 462       int start_pc, end_pc, handler_pc, catch_type;
 463       unsigned char *p = jcf->read_ptr + 8 * i;
 464       start_pc = GET_u2 (p);
 465       end_pc = GET_u2 (p+2);
 466       handler_pc = GET_u2 (p+4);
 467       catch_type = GET_u2 (p+6);
 468
 469       if (start_pc < 0 || start_pc >= length
 470           || end_pc < 0 || end_pc > length || start_pc >= end_pc
 471           || handler_pc < 0 || handler_pc >= length)
 472         {
 473           error ("bad pc in exception_table");
 474           free (exceptions);
 475           return 0;
 476         }
 477
 478       exceptions[i].handler = handler_pc;
 479       exceptions[i].start = start_pc;
 480       exceptions[i].end = end_pc;
 481       exceptions[i].type = catch_type;
 482
 483       add_handler (start_pc, end_pc,
 484                    lookup_label (handler_pc),
 485                    catch_type == 0 ? NULL_TREE
 486                    : get_class_constant (jcf, catch_type));
 487       instruction_bits[handler_pc] |= BCODE_EXCEPTION_TARGET;
 488     }
 489
 490   gcc_assert (sanity_check_exception_range (&whole_range));
 491
 492   method.method = current_function_decl;
 493   method.signature = build_java_signature (TREE_TYPE (current_function_decl));
 494   method.name = DECL_NAME (current_function_decl);
 495   method.bytes = byte_ops;
 496   method.exceptions = exceptions;
 497   method.defining_class = DECL_CONTEXT (current_function_decl);
 498   method.max_stack = DECL_MAX_STACK (current_function_decl);
 499   method.max_locals = DECL_MAX_LOCALS (current_function_decl);
 500   method.code_length = length;
 501   method.exc_count = eh_count;
 502
 503   result = verify_method (&method);
 504
 505   free (exceptions);
 506
 507   return result;
 508 }