gcc/java/verify-glue.c

   1 /* Glue to interface gcj with bytecode verifier.
   2    Copyright (C) 2003, 2004, 2005, 2006, 2007 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 "tm.h"
  31 #include "tree.h"
  32 #include "parse.h"
  33
  34 #include "verify.h"
  35 #include "java-tree.h"
  36 #include "java-except.h"
  37 #include "toplev.h"
  38
  39 void *
  40 vfy_alloc (size_t bytes)
  41 {
  42   return xmalloc (bytes);
  43 }
  44
  45 void
  46 vfy_free (void *mem)
  47 {
  48   free (mem);
  49 }
  50
  51 bool
  52 vfy_strings_equal (vfy_string one, vfy_string two)
  53 {
  54   return one == two;
  55 }
  56
  57 const char *
  58 vfy_string_bytes (vfy_string str)
  59 {
  60   return IDENTIFIER_POINTER (str);
  61 }
  62
  63 int
  64 vfy_string_length (vfy_string str)
  65 {
  66   return IDENTIFIER_LENGTH (str);
  67 }
  68
  69 vfy_string
  70 vfy_init_name (void)
  71 {
  72   return init_identifier_node;
  73 }
  74
  75 vfy_string
  76 vfy_clinit_name (void)
  77 {
  78   return clinit_identifier_node;
  79 }
  80
  81 static const char*
  82 skip_one_type (const char* ptr)
  83 {
  84   int ch = *ptr++;
  85
  86   while (ch == '[')
  87     {
  88       ch = *ptr++;
  89     }
  90
  91   if (ch == 'L')
  92     {
  93       do { ch = *ptr++; } while (ch != ';');
  94     }
  95
  96   return ptr;
  97 }
  98
  99 int
 100 vfy_count_arguments (vfy_string signature)
 101 {
 102   const char *ptr = IDENTIFIER_POINTER (signature);
 103   int arg_count = 0;
 104
 105   /* Skip '('.  */
 106   ptr++;
 107
 108   /* Count args.  */
 109   while (*ptr != ')')
 110     {
 111       ptr = skip_one_type (ptr);
 112       arg_count += 1;
 113     }
 114
 115   return arg_count;
 116 }
 117
 118 vfy_string
 119 vfy_get_string (const char *s, int len)
 120 {
 121   return get_identifier_with_length (s, len);
 122 }
 123
 124 vfy_string
 125 vfy_get_signature (vfy_method *method)
 126 {
 127   return method->signature;
 128 }
 129
 130 vfy_string
 131 vfy_get_method_name (vfy_method *method)
 132 {
 133   return method->name;
 134 }
 135
 136 bool
 137 vfy_is_static (vfy_method *method)
 138 {
 139   return METHOD_STATIC (method->method);
 140 }
 141
 142 const unsigned char *
 143 vfy_get_bytecode (vfy_method *method)
 144 {
 145   return method->bytes;
 146 }
 147
 148 vfy_exception *
 149 vfy_get_exceptions (vfy_method *method)
 150 {
 151   return method->exceptions;
 152 }
 153
 154 void
 155 vfy_get_exception (vfy_exception *exceptions, int index, int *handler,
 156                    int *start, int *end, int *handler_type)
 157 {
 158   *handler = exceptions[index].handler;
 159   *start = exceptions[index].start;
 160   *end = exceptions[index].end;
 161   *handler_type = exceptions[index].type;
 162 }
 163
 164 int
 165 vfy_tag (vfy_constants *pool, int index)
 166 {
 167   int result = JPOOL_TAG (pool, index);
 168   /* gcj will resolve constant pool entries other than string and
 169      class references.  The verifier doesn't care about the values, so
 170      we just strip off the resolved flag.  */
 171   if ((result & CONSTANT_ResolvedFlag) != 0
 172       && result != CONSTANT_ResolvedString
 173       && result != CONSTANT_ResolvedClass)
 174     result &= ~ CONSTANT_ResolvedFlag;
 175   return result;
 176 }
 177
 178 void
 179 vfy_load_indexes (vfy_constants *pool, int index,
 180                   vfy_uint_16 *index0, vfy_uint_16 *index1)
 181 {
 182   *index0 = JPOOL_USHORT1 (pool, index);
 183   *index1 = JPOOL_USHORT2 (pool, index);
 184 }
 185
 186 vfy_constants *
 187 vfy_get_constants (vfy_jclass klass)
 188 {
 189   return TYPE_JCF (klass);
 190 }
 191
 192 int
 193 vfy_get_constants_size (vfy_jclass klass)
 194 {
 195   return JPOOL_SIZE (TYPE_JCF (klass));
 196 }
 197
 198 vfy_string
 199 vfy_get_pool_string (vfy_constants *pool, int index)
 200 {
 201   return get_name_constant (pool, index);
 202 }
 203
 204 vfy_jclass
 205 vfy_get_pool_class (vfy_constants *pool, int index)
 206 {
 207   vfy_jclass k;
 208   k = get_class_constant (pool, index);
 209   return k;
 210 }
 211
 212 vfy_string
 213 vfy_get_class_name (vfy_jclass klass)
 214 {
 215   return DECL_NAME (TYPE_NAME (klass));
 216 }
 217
 218 bool
 219 vfy_is_assignable_from (vfy_jclass target, vfy_jclass source)
 220 {
 221   /* Any class is always assignable to itself, or java.lang.Object. */
 222   if (source == target || target == object_type_node)
 223     return true;
 224
 225   /* For the C++ ABI, perform this test statically. */
 226   if (! flag_indirect_dispatch)
 227     return can_widen_reference_to (source, target);
 228
 229   /* For the BC-ABI, we assume at compile time that reference types are always
 230   compatible.  However, a type assertion table entry is emitted so that the
 231   runtime can detect binary-incompatible changes.  */
 232
 233   add_type_assertion (current_class, JV_ASSERT_TYPES_COMPATIBLE, source,
 234                       target);
 235   return true;
 236 }
 237
 238 char
 239 vfy_get_primitive_char (vfy_jclass klass)
 240 {
 241   tree sig;
 242   gcc_assert (vfy_is_primitive (klass));
 243   sig = build_java_signature (klass);
 244   return (IDENTIFIER_POINTER (sig))[0];
 245 }
 246
 247 bool
 248 vfy_is_array (vfy_jclass klass)
 249 {
 250   return TYPE_ARRAY_P (klass);
 251 }
 252
 253 bool
 254 vfy_is_interface (vfy_jclass klass)
 255 {
 256   return CLASS_INTERFACE (TYPE_NAME (klass));
 257 }
 258
 259 bool
 260 vfy_is_primitive (vfy_jclass klass)
 261 {
 262   return JPRIMITIVE_TYPE_P (klass);
 263 }
 264
 265 vfy_jclass
 266 vfy_get_superclass (vfy_jclass klass)
 267 {
 268   vfy_jclass k;
 269   k = CLASSTYPE_SUPER (klass);
 270   return k;
 271 }
 272
 273 vfy_jclass
 274 vfy_get_array_class (vfy_jclass klass)
 275 {
 276   vfy_jclass k;
 277   k = build_java_array_type (klass, -1);
 278   return k;
 279 }
 280
 281 vfy_jclass
 282 vfy_get_component_type (vfy_jclass klass)
 283 {
 284   vfy_jclass k;
 285   gcc_assert (vfy_is_array (klass));
 286   k = TYPE_ARRAY_ELEMENT (klass);
 287   if (TREE_CODE (k) == POINTER_TYPE)
 288     k = TREE_TYPE (k);
 289   return k;
 290 }
 291
 292 bool
 293 vfy_is_abstract (vfy_jclass klass)
 294 {
 295   return CLASS_ABSTRACT (TYPE_NAME (klass));
 296 }
 297
 298 vfy_jclass
 299 vfy_find_class (vfy_jclass ignore ATTRIBUTE_UNUSED, vfy_string name)
 300 {
 301   vfy_jclass k;
 302
 303   k = get_type_from_signature (name);
 304   if (TREE_CODE (k) == POINTER_TYPE)
 305     k = TREE_TYPE (k);
 306
 307   return k;
 308 }
 309
 310 vfy_jclass
 311 vfy_object_type (void)
 312 {
 313   vfy_jclass k;
 314   k = object_type_node;
 315   return k;
 316 }
 317
 318 vfy_jclass
 319 vfy_class_type (void)
 320 {
 321   return class_type_node;
 322 }
 323
 324 vfy_jclass
 325 vfy_string_type (void)
 326 {
 327   vfy_jclass k;
 328   k = string_type_node;
 329   return k;
 330 }
 331
 332 vfy_jclass
 333 vfy_throwable_type (void)
 334 {
 335   vfy_jclass k;
 336   k = throwable_type_node;
 337   return k;
 338 }
 339
 340 vfy_jclass
 341 vfy_unsuitable_type (void)
 342 {
 343   return TYPE_SECOND;
 344 }
 345
 346 vfy_jclass
 347 vfy_return_address_type (void)
 348 {
 349   return TYPE_RETURN_ADDR;
 350 }
 351
 352 vfy_jclass
 353 vfy_null_type (void)
 354 {
 355   return TYPE_NULL;
 356 }
 357
 358 bool
 359 vfy_class_has_field (vfy_jclass klass, vfy_string name,
 360                      vfy_string signature)
 361 {
 362   tree field = TYPE_FIELDS (klass);
 363   while (field != NULL_TREE)
 364     {
 365       if (DECL_NAME (field) == name
 366           && build_java_signature (TREE_TYPE (field)) == signature)
 367         return true;
 368       field = TREE_CHAIN (field);
 369     }
 370   return false;
 371 }
 372
 373 int
 374 vfy_fail (const char *message, int pc, vfy_jclass ignore1 ATTRIBUTE_UNUSED,
 375           vfy_method *ignore2 ATTRIBUTE_UNUSED)
 376 {
 377   if (pc == -1)
 378     error ("verification failed: %s", message);
 379   else
 380     error ("verification failed at PC=%d: %s", pc, message);
 381   /* We have to return a value for the verifier to throw.  */
 382   return 1;
 383 }
 384
 385 vfy_jclass
 386 vfy_get_primitive_type (int type)
 387 {
 388   vfy_jclass k;
 389   k = decode_newarray_type (type);
 390   return k;
 391 }
 392
 393 void
 394 vfy_note_stack_depth (vfy_method *method, int pc, int depth)
 395 {
 396   tree val = make_tree_vec (method->max_locals + depth);
 397   VEC_replace (tree, type_states, pc, val);
 398   /* Called for side effects.  */
 399   lookup_label (pc);
 400 }
 401
 402 void
 403 vfy_note_stack_type (vfy_method *method, int pc, int slot, vfy_jclass type)
 404 {
 405   tree vec;
 406
 407   slot += method->max_locals;
 408
 409   if (type == object_type_node)
 410     type = object_ptr_type_node;
 411
 412   vec = VEC_index (tree, type_states, pc);
 413   TREE_VEC_ELT (vec, slot) = type;
 414   /* Called for side effects.  */
 415   lookup_label (pc);
 416 }
 417
 418 void
 419 vfy_note_local_type (vfy_method *method ATTRIBUTE_UNUSED, int pc, int slot,
 420                      vfy_jclass type)
 421 {
 422   tree vec;
 423
 424   if (type == object_type_node)
 425     type = object_ptr_type_node;
 426
 427   vec = VEC_index (tree, type_states, pc);
 428   TREE_VEC_ELT (vec, slot) = type;
 429   /* Called for side effects.  */
 430   lookup_label (pc);
 431 }
 432
 433 void
 434 vfy_note_instruction_seen (int pc)
 435 {
 436   instruction_bits[pc] |= BCODE_VERIFIED;
 437 }
 438
 439 /* Verify the bytecodes of the current method.
 440    Return 1 on success, 0 on failure. */
 441 int
 442 verify_jvm_instructions_new (JCF *jcf, const unsigned char *byte_ops,
 443                          long length)
 444 {
 445   vfy_method method;
 446   int i, result, eh_count;
 447   vfy_exception *exceptions;
 448
 449   method_init_exceptions ();
 450
 451   JCF_SEEK (jcf, DECL_CODE_OFFSET (current_function_decl) + length);
 452   eh_count = JCF_readu2 (jcf);
 453
 454   exceptions = (vfy_exception *) xmalloc (eh_count * sizeof (vfy_exception));
 455   for (i = 0; i < eh_count; ++i)
 456     {
 457       int start_pc, end_pc, handler_pc, catch_type;
 458       unsigned char *p = jcf->read_ptr + 8 * i;
 459       start_pc = GET_u2 (p);
 460       end_pc = GET_u2 (p+2);
 461       handler_pc = GET_u2 (p+4);
 462       catch_type = GET_u2 (p+6);
 463
 464       if (start_pc < 0 || start_pc >= length
 465           || end_pc < 0 || end_pc > length || start_pc >= end_pc
 466           || handler_pc < 0 || handler_pc >= length)
 467         {
 468           error ("bad pc in exception_table");
 469           free (exceptions);
 470           return 0;
 471         }
 472
 473       exceptions[i].handler = handler_pc;
 474       exceptions[i].start = start_pc;
 475       exceptions[i].end = end_pc;
 476       exceptions[i].type = catch_type;
 477
 478       add_handler (start_pc, end_pc,
 479                    lookup_label (handler_pc),
 480                    catch_type == 0 ? NULL_TREE
 481                    : get_class_constant (jcf, catch_type));
 482       instruction_bits[handler_pc] |= BCODE_EXCEPTION_TARGET;
 483     }
 484
 485   gcc_assert (sanity_check_exception_range (&whole_range));
 486
 487   method.method = current_function_decl;
 488   method.signature = build_java_signature (TREE_TYPE (current_function_decl));
 489   method.name = DECL_NAME (current_function_decl);
 490   method.bytes = byte_ops;
 491   method.exceptions = exceptions;
 492   method.defining_class = DECL_CONTEXT (current_function_decl);
 493   method.max_stack = DECL_MAX_STACK (current_function_decl);
 494   method.max_locals = DECL_MAX_LOCALS (current_function_decl);
 495   method.code_length = length;
 496   method.exc_count = eh_count;
 497
 498   result = verify_method (&method);
 499
 500   free (exceptions);
 501
 502   return result;
 503 }