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, 59 Temple Place - Suite 330,
  19 Boston, MA 02111-1307, 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 "errors.h"
  34 #include "parse.h"
  35
  36 #include "verify.h"
  37 #include "java-tree.h"
  38 #include "java-except.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   /* At compile time, for the BC-ABI we assume that reference types are always
 235   compatible.  However, a type assertion table entry is emitted so that the
 236   runtime can detect binary-incompatible changes.  */
 237
 238   /* FIXME: implement real test for old ABI.  */
 239
 240   /* Any class is always assignable to itself, or java.lang.Object. */
 241   if (source == target || target == object_type_node)
 242     return true;
 243
 244   /* Otherwise, a type assertion is required.  */
 245   add_type_assertion (current_class, JV_ASSERT_TYPES_COMPATIBLE, source,
 246                       target);
 247   return true;
 248 }
 249
 250 char
 251 vfy_get_primitive_char (vfy_jclass klass)
 252 {
 253   tree sig;
 254   if (! vfy_is_primitive (klass))
 255     abort ();
 256   sig = build_java_signature (klass);
 257   return (IDENTIFIER_POINTER (sig))[0];
 258 }
 259
 260 int
 261 vfy_get_interface_count (vfy_jclass klass ATTRIBUTE_UNUSED)
 262 {
 263   /* FIXME: Need to merge from mainline to get this. */
 264   #if 0
 265   return BINFO_N_BASE_BINFOS (klass);
 266   #endif
 267   return -1;
 268 }
 269
 270 vfy_jclass
 271 vfy_get_interface (vfy_jclass klass ATTRIBUTE_UNUSED, int index ATTRIBUTE_UNUSED)
 272 {
 273   /* FIXME: Need to merge from mainline to get this. */
 274   #if 0
 275   vfy_jclass k;
 276   k = BINFO_BASE_BINFO (klass, index);
 277   return k;
 278   #endif
 279   return NULL;
 280 }
 281
 282 bool
 283 vfy_is_array (vfy_jclass klass)
 284 {
 285   return TYPE_ARRAY_P (klass);
 286 }
 287
 288 bool
 289 vfy_is_interface (vfy_jclass klass)
 290 {
 291   return CLASS_INTERFACE (TYPE_NAME (klass));
 292 }
 293
 294 bool
 295 vfy_is_primitive (vfy_jclass klass)
 296 {
 297   return JPRIMITIVE_TYPE_P (klass);
 298 }
 299
 300 vfy_jclass
 301 vfy_get_superclass (vfy_jclass klass)
 302 {
 303   vfy_jclass k;
 304   k = CLASSTYPE_SUPER (klass);
 305   return k;
 306 }
 307
 308 vfy_jclass
 309 vfy_get_array_class (vfy_jclass klass)
 310 {
 311   vfy_jclass k;
 312   k = build_java_array_type (klass, -1);
 313   return k;
 314 }
 315
 316 vfy_jclass
 317 vfy_get_component_type (vfy_jclass klass)
 318 {
 319   vfy_jclass k;
 320   if (! vfy_is_array (klass))
 321     abort ();
 322   k = TYPE_ARRAY_ELEMENT (klass);
 323   if (TREE_CODE (k) == POINTER_TYPE)
 324     k = TREE_TYPE (k);
 325   return k;
 326 }
 327
 328 bool
 329 vfy_is_abstract (vfy_jclass klass)
 330 {
 331   return CLASS_ABSTRACT (TYPE_NAME (klass));
 332 }
 333
 334 vfy_jclass
 335 vfy_find_class (vfy_jclass ignore ATTRIBUTE_UNUSED, vfy_string name)
 336 {
 337   vfy_jclass k;
 338
 339   k = get_type_from_signature (name);
 340   if (TREE_CODE (k) == POINTER_TYPE)
 341     k = TREE_TYPE (k);
 342
 343   return k;
 344 }
 345
 346 vfy_jclass
 347 vfy_object_type (void)
 348 {
 349   vfy_jclass k;
 350   k = object_type_node;
 351   return k;
 352 }
 353
 354 vfy_jclass
 355 vfy_string_type (void)
 356 {
 357   vfy_jclass k;
 358   k = string_type_node;
 359   return k;
 360 }
 361
 362 vfy_jclass
 363 vfy_throwable_type (void)
 364 {
 365   vfy_jclass k;
 366   k = throwable_type_node;
 367   return k;
 368 }
 369
 370 vfy_jclass
 371 vfy_unsuitable_type (void)
 372 {
 373   return TYPE_SECOND;
 374 }
 375
 376 vfy_jclass
 377 vfy_return_address_type (void)
 378 {
 379   return TYPE_RETURN_ADDR;
 380 }
 381
 382 vfy_jclass
 383 vfy_null_type (void)
 384 {
 385   return TYPE_NULL;
 386 }
 387
 388 bool
 389 vfy_class_has_field (vfy_jclass klass, vfy_string name,
 390                      vfy_string signature)
 391 {
 392   tree field = TYPE_FIELDS (klass);
 393   while (field != NULL_TREE)
 394     {
 395       if (DECL_NAME (field) == name
 396           && build_java_signature (TREE_TYPE (field)) == signature)
 397         return true;
 398       field = TREE_CHAIN (field);
 399     }
 400   return false;
 401 }
 402
 403 int
 404 vfy_fail (const char *message, int pc, vfy_jclass ignore1 ATTRIBUTE_UNUSED,
 405           vfy_method *ignore2 ATTRIBUTE_UNUSED)
 406 {
 407   if (pc == -1)
 408     error ("verification failed: %s", message);
 409   else
 410     error ("verification failed at PC=%d: %s", pc, message);
 411   /* We have to return a value for the verifier to throw.  */
 412   return 1;
 413 }
 414
 415 vfy_jclass
 416 vfy_get_primitive_type (int type)
 417 {
 418   vfy_jclass k;
 419   k = decode_newarray_type (type);
 420   return k;
 421 }
 422
 423 void
 424 vfy_note_stack_depth (vfy_method *method, int pc, int depth)
 425 {
 426   tree label = lookup_label (pc);
 427   LABEL_TYPE_STATE (label) = make_tree_vec (method->max_locals + depth);
 428 }
 429
 430 void
 431 vfy_note_stack_type (vfy_method *method, int pc, int slot, vfy_jclass type)
 432 {
 433   tree label, vec;
 434
 435   slot += method->max_locals;
 436
 437   if (type == object_type_node)
 438     type = object_ptr_type_node;
 439
 440   label = lookup_label (pc);
 441   vec = LABEL_TYPE_STATE (label);
 442   TREE_VEC_ELT (vec, slot) = type;
 443 }
 444
 445 void
 446 vfy_note_local_type (vfy_method *method ATTRIBUTE_UNUSED, int pc, int slot,
 447                      vfy_jclass type)
 448 {
 449   tree label, vec;
 450
 451   if (type == object_type_node)
 452     type = object_ptr_type_node;
 453
 454   label = lookup_label (pc);
 455   vec = LABEL_TYPE_STATE (label);
 456   TREE_VEC_ELT (vec, slot) = type;
 457 }
 458
 459 void
 460 vfy_note_instruction_seen (int pc)
 461 {
 462   instruction_bits[pc] |= BCODE_VERIFIED;
 463 }
 464
 465 /* Verify the bytecodes of the current method.
 466    Return 1 on success, 0 on failure. */
 467 int
 468 verify_jvm_instructions_new (JCF *jcf, const unsigned char *byte_ops,
 469                          long length)
 470 {
 471   vfy_method method;
 472   int i, result, eh_count;
 473   vfy_exception *exceptions;
 474
 475   method_init_exceptions ();
 476
 477   JCF_SEEK (jcf, DECL_CODE_OFFSET (current_function_decl) + length);
 478   eh_count = JCF_readu2 (jcf);
 479
 480   exceptions = (vfy_exception *) xmalloc (eh_count * sizeof (vfy_exception));
 481   for (i = 0; i < eh_count; ++i)
 482     {
 483       int start_pc, end_pc, handler_pc, catch_type;
 484       unsigned char *p = jcf->read_ptr + 8 * i;
 485       start_pc = GET_u2 (p);
 486       end_pc = GET_u2 (p+2);
 487       handler_pc = GET_u2 (p+4);
 488       catch_type = GET_u2 (p+6);
 489
 490       if (start_pc < 0 || start_pc >= length
 491           || end_pc < 0 || end_pc > length || start_pc >= end_pc
 492           || handler_pc < 0 || handler_pc >= length)
 493         {
 494           error ("bad pc in exception_table");
 495           free (exceptions);
 496           return 0;
 497         }
 498
 499       exceptions[i].handler = handler_pc;
 500       exceptions[i].start = start_pc;
 501       exceptions[i].end = end_pc;
 502       exceptions[i].type = catch_type;
 503
 504       add_handler (start_pc, end_pc,
 505                    lookup_label (handler_pc),
 506                    catch_type == 0 ? NULL_TREE
 507                    : get_class_constant (jcf, catch_type));
 508       instruction_bits[handler_pc] |= BCODE_EXCEPTION_TARGET;
 509     }
 510
 511   handle_nested_ranges ();
 512
 513   method.method = current_function_decl;
 514   method.signature = build_java_signature (TREE_TYPE (current_function_decl));
 515   method.name = DECL_NAME (current_function_decl);
 516   method.bytes = byte_ops;
 517   method.exceptions = exceptions;
 518   method.defining_class = DECL_CONTEXT (current_function_decl);
 519   method.max_stack = DECL_MAX_STACK (current_function_decl);
 520   method.max_locals = DECL_MAX_LOCALS (current_function_decl);
 521   method.code_length = length;
 522   method.exc_count = eh_count;
 523
 524   result = verify_method (&method);
 525
 526   free (exceptions);
 527
 528   return result;
 529 }