gcc/java/verify-glue.c

   1 /* Glue to interface gcj with bytecode verifier.
   2    Copyright (C) 2003-2016 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 3, 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 COPYING3.  If not see
  18 <http://www.gnu.org/licenses/>.
  19
  20 Java and all Java-based marks are trademarks or registered trademarks
  21 of Sun Microsystems, Inc. in the United States and other countries.
  22 The Free Software Foundation is independent of Sun Microsystems, Inc.  */
  23
  24 /* Written by Tom Tromey <tromey@redhat.com>.  */
  25
  26 #include "config.h"
  27
  28 #include "system.h"
  29 #include "coretypes.h"
  30 #include "options.h"
  31 #include "stringpool.h"
  32 #include "diagnostic-core.h"
  33 #include "parse.h"
  34
  35 #include "verify.h"
  36 #include "java-except.h"
  37
  38 void *
  39 vfy_alloc (size_t bytes)
  40 {
  41   return xmalloc (bytes);
  42 }
  43
  44 void
  45 vfy_free (void *mem)
  46 {
  47   free (mem);
  48 }
  49
  50 bool
  51 vfy_strings_equal (vfy_string one, vfy_string two)
  52 {
  53   return one == two;
  54 }
  55
  56 const char *
  57 vfy_string_bytes (vfy_string str)
  58 {
  59   return IDENTIFIER_POINTER (str);
  60 }
  61
  62 int
  63 vfy_string_length (vfy_string str)
  64 {
  65   return IDENTIFIER_LENGTH (str);
  66 }
  67
  68 vfy_string
  69 vfy_init_name (void)
  70 {
  71   return init_identifier_node;
  72 }
  73
  74 vfy_string
  75 vfy_clinit_name (void)
  76 {
  77   return clinit_identifier_node;
  78 }
  79
  80 static const char*
  81 skip_one_type (const char* ptr)
  82 {
  83   int ch = *ptr++;
  84
  85   while (ch == '[')
  86     {
  87       ch = *ptr++;
  88     }
  89
  90   if (ch == 'L')
  91     {
  92       do { ch = *ptr++; } while (ch != ';');
  93     }
  94
  95   return ptr;
  96 }
  97
  98 int
  99 vfy_count_arguments (vfy_string signature)
 100 {
 101   const char *ptr = IDENTIFIER_POINTER (signature);
 102   int arg_count = 0;
 103
 104   /* Skip '('.  */
 105   ptr++;
 106
 107   /* Count args.  */
 108   while (*ptr != ')')
 109     {
 110       ptr = skip_one_type (ptr);
 111       arg_count += 1;
 112     }
 113
 114   return arg_count;
 115 }
 116
 117 vfy_string
 118 vfy_get_string (const char *s, int len)
 119 {
 120   return get_identifier_with_length (s, len);
 121 }
 122
 123 vfy_string
 124 vfy_get_signature (vfy_method *method)
 125 {
 126   return method->signature;
 127 }
 128
 129 vfy_string
 130 vfy_get_method_name (vfy_method *method)
 131 {
 132   return method->name;
 133 }
 134
 135 bool
 136 vfy_is_static (vfy_method *method)
 137 {
 138   return METHOD_STATIC (method->method);
 139 }
 140
 141 const unsigned char *
 142 vfy_get_bytecode (vfy_method *method)
 143 {
 144   return method->bytes;
 145 }
 146
 147 vfy_exception *
 148 vfy_get_exceptions (vfy_method *method)
 149 {
 150   return method->exceptions;
 151 }
 152
 153 void
 154 vfy_get_exception (vfy_exception *exceptions, int index, int *handler,
 155                    int *start, int *end, int *handler_type)
 156 {
 157   *handler = exceptions[index].handler;
 158   *start = exceptions[index].start;
 159   *end = exceptions[index].end;
 160   *handler_type = exceptions[index].type;
 161 }
 162
 163 int
 164 vfy_tag (vfy_constants *pool, int index)
 165 {
 166   int result = JPOOL_TAG (pool, index);
 167   /* gcj will resolve constant pool entries other than string and
 168      class references.  The verifier doesn't care about the values, so
 169      we just strip off the resolved flag.  */
 170   if ((result & CONSTANT_ResolvedFlag) != 0
 171       && result != CONSTANT_ResolvedString
 172       && result != CONSTANT_ResolvedClass)
 173     result &= ~ CONSTANT_ResolvedFlag;
 174   return result;
 175 }
 176
 177 void
 178 vfy_load_indexes (vfy_constants *pool, int index,
 179                   vfy_uint_16 *index0, vfy_uint_16 *index1)
 180 {
 181   *index0 = JPOOL_USHORT1 (pool, index);
 182   *index1 = JPOOL_USHORT2 (pool, index);
 183 }
 184
 185 vfy_constants *
 186 vfy_get_constants (vfy_jclass klass)
 187 {
 188   return TYPE_JCF (klass);
 189 }
 190
 191 int
 192 vfy_get_constants_size (vfy_jclass klass)
 193 {
 194   return JPOOL_SIZE (TYPE_JCF (klass));
 195 }
 196
 197 vfy_string
 198 vfy_get_pool_string (vfy_constants *pool, int index)
 199 {
 200   return get_name_constant (pool, index);
 201 }
 202
 203 vfy_jclass
 204 vfy_get_pool_class (vfy_constants *pool, int index)
 205 {
 206   vfy_jclass k;
 207   k = get_class_constant (pool, index);
 208   return k;
 209 }
 210
 211 vfy_string
 212 vfy_get_class_name (vfy_jclass klass)
 213 {
 214   return DECL_NAME (TYPE_NAME (klass));
 215 }
 216
 217 bool
 218 vfy_is_assignable_from (vfy_jclass target, vfy_jclass source)
 219 {
 220   /* Any class is always assignable to itself, or java.lang.Object. */
 221   if (source == target || target == object_type_node)
 222     return true;
 223
 224   /* For the C++ ABI, perform this test statically. */
 225   if (! flag_indirect_dispatch)
 226     return can_widen_reference_to (source, target);
 227
 228   /* For the BC-ABI, we assume at compile time that reference types are always
 229   compatible.  However, a type assertion table entry is emitted so that the
 230   runtime can detect binary-incompatible changes.  */
 231
 232   add_type_assertion (current_class, JV_ASSERT_TYPES_COMPATIBLE, source,
 233                       target);
 234   return true;
 235 }
 236
 237 char
 238 vfy_get_primitive_char (vfy_jclass klass)
 239 {
 240   tree sig;
 241   gcc_assert (vfy_is_primitive (klass));
 242   sig = build_java_signature (klass);
 243   return (IDENTIFIER_POINTER (sig))[0];
 244 }
 245
 246 bool
 247 vfy_is_array (vfy_jclass klass)
 248 {
 249   return TYPE_ARRAY_P (klass);
 250 }
 251
 252 bool
 253 vfy_is_interface (vfy_jclass klass)
 254 {
 255   return CLASS_INTERFACE (TYPE_NAME (klass));
 256 }
 257
 258 bool
 259 vfy_is_primitive (vfy_jclass klass)
 260 {
 261   return JPRIMITIVE_TYPE_P (klass);
 262 }
 263
 264 vfy_jclass
 265 vfy_get_superclass (vfy_jclass klass)
 266 {
 267   vfy_jclass k;
 268   k = CLASSTYPE_SUPER (klass);
 269   return k;
 270 }
 271
 272 vfy_jclass
 273 vfy_get_array_class (vfy_jclass klass)
 274 {
 275   vfy_jclass k;
 276   k = build_java_array_type (klass, -1);
 277   return k;
 278 }
 279
 280 vfy_jclass
 281 vfy_get_component_type (vfy_jclass klass)
 282 {
 283   vfy_jclass k;
 284   gcc_assert (vfy_is_array (klass));
 285   k = TYPE_ARRAY_ELEMENT (klass);
 286   if (TREE_CODE (k) == POINTER_TYPE)
 287     k = TREE_TYPE (k);
 288   return k;
 289 }
 290
 291 bool
 292 vfy_is_abstract (vfy_jclass klass)
 293 {
 294   return CLASS_ABSTRACT (TYPE_NAME (klass));
 295 }
 296
 297 vfy_jclass
 298 vfy_find_class (vfy_jclass ignore ATTRIBUTE_UNUSED, vfy_string name)
 299 {
 300   vfy_jclass k;
 301
 302   k = get_type_from_signature (name);
 303   if (TREE_CODE (k) == POINTER_TYPE)
 304     k = TREE_TYPE (k);
 305
 306   return k;
 307 }
 308
 309 vfy_jclass
 310 vfy_object_type (void)
 311 {
 312   vfy_jclass k;
 313   k = object_type_node;
 314   return k;
 315 }
 316
 317 vfy_jclass
 318 vfy_class_type (void)
 319 {
 320   return class_type_node;
 321 }
 322
 323 vfy_jclass
 324 vfy_string_type (void)
 325 {
 326   vfy_jclass k;
 327   k = string_type_node;
 328   return k;
 329 }
 330
 331 vfy_jclass
 332 vfy_throwable_type (void)
 333 {
 334   vfy_jclass k;
 335   k = throwable_type_node;
 336   return k;
 337 }
 338
 339 vfy_jclass
 340 vfy_unsuitable_type (void)
 341 {
 342   return TYPE_SECOND;
 343 }
 344
 345 vfy_jclass
 346 vfy_return_address_type (void)
 347 {
 348   return TYPE_RETURN_ADDR;
 349 }
 350
 351 vfy_jclass
 352 vfy_null_type (void)
 353 {
 354   return TYPE_NULL;
 355 }
 356
 357 bool
 358 vfy_class_has_field (vfy_jclass klass, vfy_string name,
 359                      vfy_string signature)
 360 {
 361   tree field = TYPE_FIELDS (klass);
 362   while (field != NULL_TREE)
 363     {
 364       if (DECL_NAME (field) == name
 365           && build_java_signature (TREE_TYPE (field)) == signature)
 366         return true;
 367       field = DECL_CHAIN (field);
 368     }
 369   return false;
 370 }
 371
 372 int
 373 vfy_fail (const char *message, int pc, vfy_jclass ignore1 ATTRIBUTE_UNUSED,
 374           vfy_method *ignore2 ATTRIBUTE_UNUSED)
 375 {
 376   if (pc == -1)
 377     error ("verification failed: %s", message);
 378   else
 379     error ("verification failed at PC=%d: %s", pc, message);
 380   /* We have to return a value for the verifier to throw.  */
 381   return 1;
 382 }
 383
 384 vfy_jclass
 385 vfy_get_primitive_type (int type)
 386 {
 387   vfy_jclass k;
 388   k = decode_newarray_type (type);
 389   return k;
 390 }
 391
 392 void
 393 vfy_note_stack_depth (vfy_method *method, int pc, int depth)
 394 {
 395   tree val = make_tree_vec (method->max_locals + depth);
 396   (*type_states)[pc] = val;
 397   /* Called for side effects.  */
 398   lookup_label (pc);
 399 }
 400
 401 void
 402 vfy_note_stack_type (vfy_method *method, int pc, int slot, vfy_jclass type)
 403 {
 404   tree vec;
 405
 406   slot += method->max_locals;
 407
 408   if (type == object_type_node)
 409     type = object_ptr_type_node;
 410
 411   vec = (*type_states)[pc];
 412   TREE_VEC_ELT (vec, slot) = type;
 413   /* Called for side effects.  */
 414   lookup_label (pc);
 415 }
 416
 417 void
 418 vfy_note_local_type (vfy_method *method ATTRIBUTE_UNUSED, int pc, int slot,
 419                      vfy_jclass type)
 420 {
 421   tree vec;
 422
 423   if (type == object_type_node)
 424     type = object_ptr_type_node;
 425
 426   vec = (*type_states)[pc];
 427   TREE_VEC_ELT (vec, slot) = type;
 428   /* Called for side effects.  */
 429   lookup_label (pc);
 430 }
 431
 432 void
 433 vfy_note_instruction_seen (int pc)
 434 {
 435   instruction_bits[pc] |= BCODE_VERIFIED;
 436 }
 437
 438 /* Verify the bytecodes of the current method.
 439    Return 1 on success, 0 on failure. */
 440 int
 441 verify_jvm_instructions_new (JCF *jcf, const unsigned char *byte_ops,
 442                          long length)
 443 {
 444   vfy_method method;
 445   int i, result, eh_count;
 446   vfy_exception *exceptions;
 447
 448   method_init_exceptions ();
 449
 450   JCF_SEEK (jcf, DECL_CODE_OFFSET (current_function_decl) + length);
 451   eh_count = JCF_readu2 (jcf);
 452
 453   exceptions = (vfy_exception *) xmalloc (eh_count * sizeof (vfy_exception));
 454   for (i = 0; i < eh_count; ++i)
 455     {
 456       int start_pc, end_pc, handler_pc, catch_type;
 457       unsigned char *p = jcf->read_ptr + 8 * i;
 458       start_pc = GET_u2 (p);
 459       end_pc = GET_u2 (p+2);
 460       handler_pc = GET_u2 (p+4);
 461       catch_type = GET_u2 (p+6);
 462
 463       if (start_pc < 0 || start_pc >= length
 464           || end_pc < 0 || end_pc > length || start_pc >= end_pc
 465           || handler_pc < 0 || handler_pc >= length)
 466         {
 467           error ("bad pc in exception_table");
 468           free (exceptions);
 469           return 0;
 470         }
 471
 472       exceptions[i].handler = handler_pc;
 473       exceptions[i].start = start_pc;
 474       exceptions[i].end = end_pc;
 475       exceptions[i].type = catch_type;
 476
 477       add_handler (start_pc, end_pc,
 478                    lookup_label (handler_pc),
 479                    catch_type == 0 ? NULL_TREE
 480                    : get_class_constant (jcf, catch_type));
 481       instruction_bits[handler_pc] |= BCODE_EXCEPTION_TARGET;
 482     }
 483
 484   gcc_assert (sanity_check_exception_range (&whole_range));
 485
 486   method.method = current_function_decl;
 487   method.signature = build_java_signature (TREE_TYPE (current_function_decl));
 488   method.name = DECL_NAME (current_function_decl);
 489   method.bytes = byte_ops;
 490   method.exceptions = exceptions;
 491   method.defining_class = DECL_CONTEXT (current_function_decl);
 492   method.max_stack = DECL_MAX_STACK (current_function_decl);
 493   method.max_locals = DECL_MAX_LOCALS (current_function_decl);
 494   method.code_length = length;
 495   method.exc_count = eh_count;
 496
 497   result = verify_method (&method);
 498
 499   free (exceptions);
 500
 501   return result;
 502 }