1 /*
   2  * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "classfile/symbolTable.hpp"
  27 #include "classfile/systemDictionary.hpp"
  28 #include "memory/oopFactory.hpp"
  29 #include "oops/instanceKlass.hpp"
  30 #include "oops/oop.inline.hpp"
  31 #include "oops/symbol.hpp"
  32 #include "oops/typeArrayKlass.hpp"
  33 #include "runtime/signature.hpp"
  34 
  35 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
  36 
  37 // Implementation of SignatureIterator
  38 
  39 // Signature syntax:
  40 //
  41 // Signature  = "(" {Parameter} ")" ReturnType.
  42 // Parameter  = FieldType.
  43 // ReturnType = FieldType | "V".
  44 // FieldType  = "B" | "C" | "D" | "F" | "I" | "J" | "S" | "Z" | "L" ClassName ";" | "[" FieldType.
  45 // ClassName  = string.
  46 
  47 
  48 SignatureIterator::SignatureIterator(Symbol* signature) {
  49   _signature       = signature;
  50   _parameter_index = 0;
  51 }
  52 
  53 void SignatureIterator::expect(char c) {
  54   if (_signature->byte_at(_index) != c) fatal(err_msg("expecting %c", c));
  55   _index++;
  56 }
  57 
  58 
  59 void SignatureIterator::skip_optional_size() {
  60   Symbol* sig = _signature;
  61   char c = sig->byte_at(_index);
  62   while ('0' <= c && c <= '9') c = sig->byte_at(++_index);
  63 }
  64 
  65 
  66 int SignatureIterator::parse_type() {
  67   // Note: This function could be simplified by using "return T_XXX_size;"
  68   //       instead of the assignment and the break statements. However, it
  69   //       seems that the product build for win32_i486 with MS VC++ 6.0 doesn't
  70   //       work (stack underflow for some tests) - this seems to be a VC++ 6.0
  71   //       compiler bug (was problem - gri 4/27/2000).
  72   int size = -1;
  73   switch(_signature->byte_at(_index)) {
  74     case 'B': do_byte  (); if (_parameter_index < 0 ) _return_type = T_BYTE;
  75               _index++; size = T_BYTE_size   ; break;
  76     case 'C': do_char  (); if (_parameter_index < 0 ) _return_type = T_CHAR;
  77               _index++; size = T_CHAR_size   ; break;
  78     case 'D': do_double(); if (_parameter_index < 0 ) _return_type = T_DOUBLE;
  79               _index++; size = T_DOUBLE_size ; break;
  80     case 'F': do_float (); if (_parameter_index < 0 ) _return_type = T_FLOAT;
  81               _index++; size = T_FLOAT_size  ; break;
  82     case 'I': do_int   (); if (_parameter_index < 0 ) _return_type = T_INT;
  83               _index++; size = T_INT_size    ; break;
  84     case 'J': do_long  (); if (_parameter_index < 0 ) _return_type = T_LONG;
  85               _index++; size = T_LONG_size   ; break;
  86     case 'S': do_short (); if (_parameter_index < 0 ) _return_type = T_SHORT;
  87               _index++; size = T_SHORT_size  ; break;
  88     case 'Z': do_bool  (); if (_parameter_index < 0 ) _return_type = T_BOOLEAN;
  89               _index++; size = T_BOOLEAN_size; break;
  90     case 'V': do_void  (); if (_parameter_index < 0 ) _return_type = T_VOID;
  91               _index++; size = T_VOID_size;  ; break;
  92     case 'L':
  93       { int begin = ++_index;
  94         Symbol* sig = _signature;
  95         while (sig->byte_at(_index++) != ';') ;
  96         do_object(begin, _index);
  97       }
  98       if (_parameter_index < 0 ) _return_type = T_OBJECT;
  99       size = T_OBJECT_size;
 100       break;
 101     case '[':
 102       { int begin = ++_index;
 103         skip_optional_size();
 104         Symbol* sig = _signature;
 105         while (sig->byte_at(_index) == '[') {
 106           _index++;
 107           skip_optional_size();
 108         }
 109         if (sig->byte_at(_index) == 'L') {
 110           while (sig->byte_at(_index++) != ';') ;
 111         } else {
 112           _index++;
 113         }
 114         do_array(begin, _index);
 115        if (_parameter_index < 0 ) _return_type = T_ARRAY;
 116       }
 117       size = T_ARRAY_size;
 118       break;
 119     default:
 120       ShouldNotReachHere();
 121       break;
 122   }
 123   assert(size >= 0, "size must be set");
 124   return size;
 125 }
 126 
 127 
 128 void SignatureIterator::check_signature_end() {
 129   if (_index < _signature->utf8_length()) {
 130     tty->print_cr("too many chars in signature");
 131     _signature->print_value_on(tty);
 132     tty->print_cr(" @ %d", _index);
 133   }
 134 }
 135 
 136 
 137 void SignatureIterator::dispatch_field() {
 138   // no '(', just one (field) type
 139   _index = 0;
 140   _parameter_index = 0;
 141   parse_type();
 142   check_signature_end();
 143 }
 144 
 145 
 146 void SignatureIterator::iterate_parameters() {
 147   // Parse parameters
 148   _index = 0;
 149   _parameter_index = 0;
 150   expect('(');
 151   while (_signature->byte_at(_index) != ')') _parameter_index += parse_type();
 152   expect(')');
 153   _parameter_index = 0;
 154 }
 155 
 156 // Optimized version of iterate_parameters when fingerprint is known
 157 void SignatureIterator::iterate_parameters( uint64_t fingerprint ) {
 158   uint64_t saved_fingerprint = fingerprint;
 159 
 160   // Check for too many arguments
 161   if (fingerprint == (uint64_t)CONST64(-1)) {
 162     SignatureIterator::iterate_parameters();
 163     return;
 164   }
 165 
 166   assert(fingerprint, "Fingerprint should not be 0");
 167 
 168   _parameter_index = 0;
 169   fingerprint = fingerprint >> (static_feature_size + result_feature_size);
 170   while ( 1 ) {
 171     switch ( fingerprint & parameter_feature_mask ) {
 172       case bool_parm:
 173         do_bool();
 174         _parameter_index += T_BOOLEAN_size;
 175         break;
 176       case byte_parm:
 177         do_byte();
 178         _parameter_index += T_BYTE_size;
 179         break;
 180       case char_parm:
 181         do_char();
 182         _parameter_index += T_CHAR_size;
 183         break;
 184       case short_parm:
 185         do_short();
 186         _parameter_index += T_SHORT_size;
 187         break;
 188       case int_parm:
 189         do_int();
 190         _parameter_index += T_INT_size;
 191         break;
 192       case obj_parm:
 193         do_object(0, 0);
 194         _parameter_index += T_OBJECT_size;
 195         break;
 196       case long_parm:
 197         do_long();
 198         _parameter_index += T_LONG_size;
 199         break;
 200       case float_parm:
 201         do_float();
 202         _parameter_index += T_FLOAT_size;
 203         break;
 204       case double_parm:
 205         do_double();
 206         _parameter_index += T_DOUBLE_size;
 207         break;
 208       case done_parm:
 209         return;
 210         break;
 211       default:
 212         tty->print_cr("*** parameter is %d", fingerprint & parameter_feature_mask);
 213         tty->print_cr("*** fingerprint is " PTR64_FORMAT, saved_fingerprint);
 214         ShouldNotReachHere();
 215         break;
 216     }
 217     fingerprint >>= parameter_feature_size;
 218   }
 219   _parameter_index = 0;
 220 }
 221 
 222 
 223 void SignatureIterator::iterate_returntype() {
 224   // Ignore parameters
 225   _index = 0;
 226   expect('(');
 227   Symbol* sig = _signature;
 228   while (sig->byte_at(_index) != ')') _index++;
 229   expect(')');
 230   // Parse return type
 231   _parameter_index = -1;
 232   parse_type();
 233   check_signature_end();
 234   _parameter_index = 0;
 235 }
 236 
 237 
 238 void SignatureIterator::iterate() {
 239   // Parse parameters
 240   _parameter_index = 0;
 241   _index = 0;
 242   expect('(');
 243   while (_signature->byte_at(_index) != ')') _parameter_index += parse_type();
 244   expect(')');
 245   // Parse return type
 246   _parameter_index = -1;
 247   parse_type();
 248   check_signature_end();
 249   _parameter_index = 0;
 250 }
 251 
 252 
 253 // Implementation of SignatureStream
 254 SignatureStream::SignatureStream(Symbol* signature, bool is_method) :
 255                    _signature(signature), _at_return_type(false) {
 256   _begin = _end = (is_method ? 1 : 0);  // skip first '(' in method signatures
 257   _names = new GrowableArray<Symbol*>(10);
 258   next();
 259 }
 260 
 261 SignatureStream::~SignatureStream() {
 262   // decrement refcount for names created during signature parsing
 263   for (int i = 0; i < _names->length(); i++) {
 264     _names->at(i)->decrement_refcount();
 265   }
 266 }
 267 
 268 bool SignatureStream::is_done() const {
 269   return _end > _signature->utf8_length();
 270 }
 271 
 272 
 273 void SignatureStream::next_non_primitive(int t) {
 274   switch (t) {
 275     case 'L': {
 276       _type = T_OBJECT;
 277       Symbol* sig = _signature;
 278       while (sig->byte_at(_end++) != ';');
 279       break;
 280     }
 281     case '[': {
 282       _type = T_ARRAY;
 283       Symbol* sig = _signature;
 284       char c = sig->byte_at(_end);
 285       while ('0' <= c && c <= '9') c = sig->byte_at(_end++);
 286       while (sig->byte_at(_end) == '[') {
 287         _end++;
 288         c = sig->byte_at(_end);
 289         while ('0' <= c && c <= '9') c = sig->byte_at(_end++);
 290       }
 291       switch(sig->byte_at(_end)) {
 292         case 'B':
 293         case 'C':
 294         case 'D':
 295         case 'F':
 296         case 'I':
 297         case 'J':
 298         case 'S':
 299         case 'Z':_end++; break;
 300         default: {
 301           while (sig->byte_at(_end++) != ';');
 302           break;
 303         }
 304       }
 305       break;
 306     }
 307     case ')': _end++; next(); _at_return_type = true; break;
 308     default : ShouldNotReachHere();
 309   }
 310 }
 311 
 312 
 313 bool SignatureStream::is_object() const {
 314   return _type == T_OBJECT
 315       || _type == T_ARRAY;
 316 }
 317 
 318 bool SignatureStream::is_array() const {
 319   return _type == T_ARRAY;
 320 }
 321 
 322 Symbol* SignatureStream::as_symbol(TRAPS) {
 323   // Create a symbol from for string _begin _end
 324   int begin = _begin;
 325   int end   = _end;
 326 
 327   if (   _signature->byte_at(_begin) == 'L'
 328       && _signature->byte_at(_end-1) == ';') {
 329     begin++;
 330     end--;
 331   }
 332 
 333   // Save names for cleaning up reference count at the end of
 334   // SignatureStream scope.
 335   Symbol* name = SymbolTable::new_symbol(_signature, begin, end, CHECK_NULL);
 336   _names->push(name);  // save new symbol for decrementing later
 337   return name;
 338 }
 339 
 340 Klass* SignatureStream::as_klass(Handle class_loader, Handle protection_domain,
 341                                    FailureMode failure_mode, TRAPS) {
 342   if (!is_object())  return NULL;
 343   Symbol* name = as_symbol(CHECK_NULL);
 344   if (failure_mode == ReturnNull) {
 345     return SystemDictionary::resolve_or_null(name, class_loader, protection_domain, THREAD);
 346   } else {
 347     bool throw_error = (failure_mode == NCDFError);
 348     return SystemDictionary::resolve_or_fail(name, class_loader, protection_domain, throw_error, THREAD);
 349   }
 350 }
 351 
 352 oop SignatureStream::as_java_mirror(Handle class_loader, Handle protection_domain,
 353                                     FailureMode failure_mode, TRAPS) {
 354   if (!is_object())
 355     return Universe::java_mirror(type());
 356   Klass* klass = as_klass(class_loader, protection_domain, failure_mode, CHECK_NULL);
 357   if (klass == NULL)  return NULL;
 358   return klass->java_mirror();
 359 }
 360 
 361 Symbol* SignatureStream::as_symbol_or_null() {
 362   // Create a symbol from for string _begin _end
 363   ResourceMark rm;
 364 
 365   int begin = _begin;
 366   int end   = _end;
 367 
 368   if (   _signature->byte_at(_begin) == 'L'
 369       && _signature->byte_at(_end-1) == ';') {
 370     begin++;
 371     end--;
 372   }
 373 
 374   char* buffer = NEW_RESOURCE_ARRAY(char, end - begin);
 375   for (int index = begin; index < end; index++) {
 376     buffer[index - begin] = _signature->byte_at(index);
 377   }
 378   Symbol* result = SymbolTable::probe(buffer, end - begin);
 379   return result;
 380 }
 381 
 382 int SignatureStream::reference_parameter_count() {
 383   int args_count = 0;
 384   for ( ; !at_return_type(); next()) {
 385     if (is_object()) {
 386       args_count++;
 387     }
 388   }
 389   return args_count;
 390 }
 391 
 392 bool SignatureVerifier::is_valid_signature(Symbol* sig) {
 393   const char* signature = (const char*)sig->bytes();
 394   ssize_t len = sig->utf8_length();
 395   if (signature == NULL || signature[0] == '\0' || len < 1) {
 396     return false;
 397   } else if (signature[0] == '(') {
 398     return is_valid_method_signature(sig);
 399   } else {
 400     return is_valid_type_signature(sig);
 401   }
 402 }
 403 
 404 bool SignatureVerifier::is_valid_method_signature(Symbol* sig) {
 405   const char* method_sig = (const char*)sig->bytes();
 406   ssize_t len = sig->utf8_length();
 407   ssize_t index = 0;
 408   if (method_sig != NULL && len > 1 && method_sig[index] == '(') {
 409     ++index;
 410     while (index < len && method_sig[index] != ')') {
 411       ssize_t res = is_valid_type(&method_sig[index], len - index);
 412       if (res == -1) {
 413         return false;
 414       } else {
 415         index += res;
 416       }
 417     }
 418     if (index < len && method_sig[index] == ')') {
 419       // check the return type
 420       ++index;
 421       return (is_valid_type(&method_sig[index], len - index) == (len - index));
 422     }
 423   }
 424   return false;
 425 }
 426 
 427 bool SignatureVerifier::is_valid_type_signature(Symbol* sig) {
 428   const char* type_sig = (const char*)sig->bytes();
 429   ssize_t len = sig->utf8_length();
 430   return (type_sig != NULL && len >= 1 &&
 431           (is_valid_type(type_sig, len) == len));
 432 }
 433 
 434 // Checks to see if the type (not to go beyond 'limit') refers to a valid type.
 435 // Returns -1 if it is not, or the index of the next character that is not part
 436 // of the type.  The type encoding may end before 'limit' and that's ok.
 437 ssize_t SignatureVerifier::is_valid_type(const char* type, ssize_t limit) {
 438   ssize_t index = 0;
 439 
 440   // Iterate over any number of array dimensions
 441   while (index < limit && type[index] == '[') ++index;
 442   if (index >= limit) {
 443     return -1;
 444   }
 445   switch (type[index]) {
 446     case 'B': case 'C': case 'D': case 'F': case 'I':
 447     case 'J': case 'S': case 'Z': case 'V':
 448       return index + 1;
 449     case 'L':
 450       for (index = index + 1; index < limit; ++index) {
 451         char c = type[index];
 452         if (c == ';') {
 453           return index + 1;
 454         }
 455         if (invalid_name_char(c)) {
 456           return -1;
 457         }
 458       }
 459       // fall through
 460     default: ; // fall through
 461   }
 462   return -1;
 463 }
 464 
 465 bool SignatureVerifier::invalid_name_char(char c) {
 466   switch (c) {
 467     case '\0': case '.': case ';': case '[':
 468       return true;
 469     default:
 470       return false;
 471   }
 472 }