1 /*
   2  * Copyright (c) 1997, 2019, 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 "memory/resourceArea.hpp"
  30 #include "memory/universe.hpp"
  31 #include "oops/instanceKlass.hpp"
  32 #include "oops/oop.inline.hpp"
  33 #include "oops/symbol.hpp"
  34 #include "oops/typeArrayKlass.hpp"
  35 #include "runtime/signature.hpp"
  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->char_at(_index) != c) fatal("expecting %c", c);
  55   _index++;
  56 }
  57 
  58 int SignatureIterator::parse_type() {
  59   // Note: This function could be simplified by using "return T_XXX_size;"
  60   //       instead of the assignment and the break statements. However, it
  61   //       seems that the product build for win32_i486 with MS VC++ 6.0 doesn't
  62   //       work (stack underflow for some tests) - this seems to be a VC++ 6.0
  63   //       compiler bug (was problem - gri 4/27/2000).
  64   int size = -1;
  65   switch(_signature->char_at(_index)) {
  66     case JVM_SIGNATURE_BYTE:    do_byte(); if (_parameter_index < 0 ) _return_type = T_BYTE;
  67                                   _index++; size = T_BYTE_size; break;
  68     case JVM_SIGNATURE_CHAR:    do_char(); if (_parameter_index < 0 ) _return_type = T_CHAR;
  69                                   _index++; size = T_CHAR_size; break;
  70     case JVM_SIGNATURE_DOUBLE:  do_double(); if (_parameter_index < 0 ) _return_type = T_DOUBLE;
  71                                   _index++; size = T_DOUBLE_size; break;
  72     case JVM_SIGNATURE_FLOAT:   do_float(); if (_parameter_index < 0 ) _return_type = T_FLOAT;
  73                                   _index++; size = T_FLOAT_size; break;
  74     case JVM_SIGNATURE_INT:     do_int(); if (_parameter_index < 0 ) _return_type = T_INT;
  75                                   _index++; size = T_INT_size; break;
  76     case JVM_SIGNATURE_LONG:    do_long(); if (_parameter_index < 0 ) _return_type = T_LONG;
  77                                   _index++; size = T_LONG_size; break;
  78     case JVM_SIGNATURE_SHORT:   do_short(); if (_parameter_index < 0 ) _return_type = T_SHORT;
  79                                   _index++; size = T_SHORT_size; break;
  80     case JVM_SIGNATURE_BOOLEAN: do_bool(); if (_parameter_index < 0 ) _return_type = T_BOOLEAN;
  81                                   _index++; size = T_BOOLEAN_size; break;
  82     case JVM_SIGNATURE_VOID:    do_void(); if (_parameter_index < 0 ) _return_type = T_VOID;
  83                                   _index++; size = T_VOID_size; break;
  84     case JVM_SIGNATURE_CLASS:
  85       { int begin = ++_index;
  86         Symbol* sig = _signature;
  87         while (sig->char_at(_index++) != JVM_SIGNATURE_ENDCLASS) ;
  88         do_object(begin, _index);
  89       }
  90       if (_parameter_index < 0 ) _return_type = T_OBJECT;
  91       size = T_OBJECT_size;
  92       break;
  93     case JVM_SIGNATURE_ARRAY:
  94       { int begin = ++_index;
  95         Symbol* sig = _signature;
  96         while (sig->char_at(_index) == JVM_SIGNATURE_ARRAY) {
  97           _index++;
  98         }
  99         if (sig->char_at(_index) == JVM_SIGNATURE_CLASS) {
 100           while (sig->char_at(_index++) != JVM_SIGNATURE_ENDCLASS) ;
 101         } else {
 102           _index++;
 103         }
 104         do_array(begin, _index);
 105        if (_parameter_index < 0 ) _return_type = T_ARRAY;
 106       }
 107       size = T_ARRAY_size;
 108       break;
 109     default:
 110       ShouldNotReachHere();
 111       break;
 112   }
 113   assert(size >= 0, "size must be set");
 114   return size;
 115 }
 116 
 117 
 118 void SignatureIterator::check_signature_end() {
 119   if (_index < _signature->utf8_length()) {
 120     tty->print_cr("too many chars in signature");
 121     _signature->print_value_on(tty);
 122     tty->print_cr(" @ %d", _index);
 123   }
 124 }
 125 
 126 
 127 void SignatureIterator::iterate_parameters() {
 128   // Parse parameters
 129   _index = 0;
 130   _parameter_index = 0;
 131   expect(JVM_SIGNATURE_FUNC);
 132   while (_signature->char_at(_index) != JVM_SIGNATURE_ENDFUNC) _parameter_index += parse_type();
 133   expect(JVM_SIGNATURE_ENDFUNC);
 134   _parameter_index = 0;
 135 }
 136 
 137 // Optimized version of iterate_parameters when fingerprint is known
 138 void SignatureIterator::iterate_parameters( uint64_t fingerprint ) {
 139   uint64_t saved_fingerprint = fingerprint;
 140 
 141   // Check for too many arguments
 142   if (fingerprint == (uint64_t)CONST64(-1)) {
 143     SignatureIterator::iterate_parameters();
 144     return;
 145   }
 146 
 147   assert(fingerprint, "Fingerprint should not be 0");
 148 
 149   _parameter_index = 0;
 150   fingerprint = fingerprint >> (static_feature_size + result_feature_size);
 151   while ( 1 ) {
 152     switch ( fingerprint & parameter_feature_mask ) {
 153       case bool_parm:
 154         do_bool();
 155         _parameter_index += T_BOOLEAN_size;
 156         break;
 157       case byte_parm:
 158         do_byte();
 159         _parameter_index += T_BYTE_size;
 160         break;
 161       case char_parm:
 162         do_char();
 163         _parameter_index += T_CHAR_size;
 164         break;
 165       case short_parm:
 166         do_short();
 167         _parameter_index += T_SHORT_size;
 168         break;
 169       case int_parm:
 170         do_int();
 171         _parameter_index += T_INT_size;
 172         break;
 173       case obj_parm:
 174         do_object(0, 0);
 175         _parameter_index += T_OBJECT_size;
 176         break;
 177       case long_parm:
 178         do_long();
 179         _parameter_index += T_LONG_size;
 180         break;
 181       case float_parm:
 182         do_float();
 183         _parameter_index += T_FLOAT_size;
 184         break;
 185       case double_parm:
 186         do_double();
 187         _parameter_index += T_DOUBLE_size;
 188         break;
 189       case done_parm:
 190         return;
 191       default:
 192         tty->print_cr("*** parameter is " UINT64_FORMAT, fingerprint & parameter_feature_mask);
 193         tty->print_cr("*** fingerprint is " PTR64_FORMAT, saved_fingerprint);
 194         ShouldNotReachHere();
 195         break;
 196     }
 197     fingerprint >>= parameter_feature_size;
 198   }
 199 }
 200 
 201 
 202 void SignatureIterator::iterate_returntype() {
 203   // Ignore parameters
 204   _index = 0;
 205   expect(JVM_SIGNATURE_FUNC);
 206   Symbol* sig = _signature;
 207   // Need to skip over each type in the signature's argument list until a
 208   // closing ')' is found., then get the return type.  We cannot just scan
 209   // for the first ')' because ')' is a legal character in a type name.
 210   while (sig->char_at(_index) != JVM_SIGNATURE_ENDFUNC) {
 211     switch(sig->char_at(_index)) {
 212       case JVM_SIGNATURE_BYTE:
 213       case JVM_SIGNATURE_CHAR:
 214       case JVM_SIGNATURE_DOUBLE:
 215       case JVM_SIGNATURE_FLOAT:
 216       case JVM_SIGNATURE_INT:
 217       case JVM_SIGNATURE_LONG:
 218       case JVM_SIGNATURE_SHORT:
 219       case JVM_SIGNATURE_BOOLEAN:
 220       case JVM_SIGNATURE_VOID:
 221         {
 222           _index++;
 223         }
 224         break;
 225       case JVM_SIGNATURE_CLASS:
 226         {
 227           while (sig->char_at(_index++) != JVM_SIGNATURE_ENDCLASS) ;
 228         }
 229         break;
 230       case JVM_SIGNATURE_ARRAY:
 231         {
 232           while (sig->char_at(++_index) == JVM_SIGNATURE_ARRAY) ;
 233           if (sig->char_at(_index) == JVM_SIGNATURE_CLASS) {
 234             while (sig->char_at(_index++) != JVM_SIGNATURE_ENDCLASS) ;
 235           } else {
 236             _index++;
 237           }
 238         }
 239         break;
 240       default:
 241         ShouldNotReachHere();
 242         break;
 243     }
 244   }
 245   expect(JVM_SIGNATURE_ENDFUNC);
 246   // Parse return type
 247   _parameter_index = -1;
 248   parse_type();
 249   check_signature_end();
 250   _parameter_index = 0;
 251 }
 252 
 253 
 254 void SignatureIterator::iterate() {
 255   // Parse parameters
 256   _parameter_index = 0;
 257   _index = 0;
 258   expect(JVM_SIGNATURE_FUNC);
 259   while (_signature->char_at(_index) != JVM_SIGNATURE_ENDFUNC) _parameter_index += parse_type();
 260   expect(JVM_SIGNATURE_ENDFUNC);
 261   // Parse return type
 262   _parameter_index = -1;
 263   parse_type();
 264   check_signature_end();
 265   _parameter_index = 0;
 266 }
 267 
 268 
 269 // Implementation of SignatureStream
 270 SignatureStream::SignatureStream(Symbol* signature, bool is_method) :
 271                    _signature(signature), _at_return_type(false), _previous_name(NULL), _names(NULL) {
 272   _begin = _end = (is_method ? 1 : 0);  // skip first '(' in method signatures
 273   next();
 274 }
 275 
 276 SignatureStream::~SignatureStream() {
 277   // decrement refcount for names created during signature parsing
 278   if (_names != NULL) {
 279     for (int i = 0; i < _names->length(); i++) {
 280       _names->at(i)->decrement_refcount();
 281     }
 282   }
 283 }
 284 
 285 bool SignatureStream::is_done() const {
 286   return _end > _signature->utf8_length();
 287 }
 288 
 289 
 290 void SignatureStream::next_non_primitive(int t) {
 291   switch (t) {
 292     case JVM_SIGNATURE_CLASS: {
 293       _type = T_OBJECT;
 294       Symbol* sig = _signature;
 295       while (sig->char_at(_end++) != JVM_SIGNATURE_ENDCLASS);
 296       break;
 297     }
 298     case JVM_SIGNATURE_ARRAY: {
 299       _type = T_ARRAY;
 300       Symbol* sig = _signature;
 301       char c = sig->char_at(_end);
 302       while ('0' <= c && c <= '9') c = sig->char_at(_end++);
 303       while (sig->char_at(_end) == JVM_SIGNATURE_ARRAY) {
 304         _end++;
 305         c = sig->char_at(_end);
 306         while ('0' <= c && c <= '9') c = sig->char_at(_end++);
 307       }
 308       switch(sig->char_at(_end)) {
 309         case JVM_SIGNATURE_BYTE:
 310         case JVM_SIGNATURE_CHAR:
 311         case JVM_SIGNATURE_DOUBLE:
 312         case JVM_SIGNATURE_FLOAT:
 313         case JVM_SIGNATURE_INT:
 314         case JVM_SIGNATURE_LONG:
 315         case JVM_SIGNATURE_SHORT:
 316         case JVM_SIGNATURE_BOOLEAN:_end++; break;
 317         default: {
 318           while (sig->char_at(_end++) != JVM_SIGNATURE_ENDCLASS);
 319           break;
 320         }
 321       }
 322       break;
 323     }
 324     case JVM_SIGNATURE_ENDFUNC: _end++; next(); _at_return_type = true; break;
 325     default : ShouldNotReachHere();
 326   }
 327 }
 328 
 329 
 330 bool SignatureStream::is_object() const {
 331   return _type == T_OBJECT
 332       || _type == T_ARRAY;
 333 }
 334 
 335 bool SignatureStream::is_array() const {
 336   return _type == T_ARRAY;
 337 }
 338 
 339 Symbol* SignatureStream::as_symbol() {
 340   // Create a symbol from for string _begin _end
 341   int begin = _begin;
 342   int end   = _end;
 343 
 344   if (   _signature->char_at(_begin) == JVM_SIGNATURE_CLASS
 345       && _signature->char_at(_end-1) == JVM_SIGNATURE_ENDCLASS) {
 346     begin++;
 347     end--;
 348   }
 349 
 350   const char* symbol_chars = (const char*)_signature->base() + begin;
 351   int len = end - begin;
 352 
 353   // Quick check for common symbols in signatures
 354   assert((vmSymbols::java_lang_String()->utf8_length() == 16 && vmSymbols::java_lang_Object()->utf8_length() == 16), "sanity");
 355   if (len == 16 &&
 356       strncmp(symbol_chars, "java/lang/", 10) == 0) {
 357     if (strncmp("String", symbol_chars + 10, 6) == 0) {
 358       return vmSymbols::java_lang_String();
 359     } else if (strncmp("Object", symbol_chars + 10, 6) == 0) {
 360       return vmSymbols::java_lang_Object();
 361     }
 362   }
 363 
 364   Symbol* name = _previous_name;
 365   if (name != NULL && name->equals(symbol_chars, len)) {
 366     return name;
 367   }
 368 
 369   // Save names for cleaning up reference count at the end of
 370   // SignatureStream scope.
 371   name = SymbolTable::new_symbol(symbol_chars, len);
 372   if (!name->is_permanent()) {
 373     if (_names == NULL) {
 374       _names = new GrowableArray<Symbol*>(10);
 375     }
 376     _names->push(name);  // save new symbol for decrementing later
 377   }
 378   _previous_name = name;
 379   return name;
 380 }
 381 
 382 Klass* SignatureStream::as_klass(Handle class_loader, Handle protection_domain,
 383                                  FailureMode failure_mode, TRAPS) {
 384   if (!is_object())  return NULL;
 385   Symbol* name = as_symbol();
 386   if (failure_mode == ReturnNull) {
 387     return SystemDictionary::resolve_or_null(name, class_loader, protection_domain, THREAD);
 388   } else {
 389     bool throw_error = (failure_mode == NCDFError);
 390     return SystemDictionary::resolve_or_fail(name, class_loader, protection_domain, throw_error, THREAD);
 391   }
 392 }
 393 
 394 oop SignatureStream::as_java_mirror(Handle class_loader, Handle protection_domain,
 395                                     FailureMode failure_mode, TRAPS) {
 396   if (!is_object())
 397     return Universe::java_mirror(type());
 398   Klass* klass = as_klass(class_loader, protection_domain, failure_mode, CHECK_NULL);
 399   if (klass == NULL)  return NULL;
 400   return klass->java_mirror();
 401 }
 402 
 403 Symbol* SignatureStream::as_symbol_or_null() {
 404   // Create a symbol from for string _begin _end
 405   ResourceMark rm;
 406 
 407   int begin = _begin;
 408   int end   = _end;
 409 
 410   if (   _signature->char_at(_begin) == JVM_SIGNATURE_CLASS
 411       && _signature->char_at(_end-1) == JVM_SIGNATURE_ENDCLASS) {
 412     begin++;
 413     end--;
 414   }
 415 
 416   char* buffer = NEW_RESOURCE_ARRAY(char, end - begin);
 417   for (int index = begin; index < end; index++) {
 418     buffer[index - begin] = _signature->char_at(index);
 419   }
 420   Symbol* result = SymbolTable::probe(buffer, end - begin);
 421   return result;
 422 }
 423 
 424 int SignatureStream::reference_parameter_count() {
 425   int args_count = 0;
 426   for ( ; !at_return_type(); next()) {
 427     if (is_object()) {
 428       args_count++;
 429     }
 430   }
 431   return args_count;
 432 }
 433 
 434 #ifdef ASSERT
 435 bool SignatureVerifier::is_valid_method_signature(Symbol* sig) {
 436   const char* method_sig = (const char*)sig->bytes();
 437   ssize_t len = sig->utf8_length();
 438   ssize_t index = 0;
 439   if (method_sig != NULL && len > 1 && method_sig[index] == JVM_SIGNATURE_FUNC) {
 440     ++index;
 441     while (index < len && method_sig[index] != JVM_SIGNATURE_ENDFUNC) {
 442       ssize_t res = is_valid_type(&method_sig[index], len - index);
 443       if (res == -1) {
 444         return false;
 445       } else {
 446         index += res;
 447       }
 448     }
 449     if (index < len && method_sig[index] == JVM_SIGNATURE_ENDFUNC) {
 450       // check the return type
 451       ++index;
 452       return (is_valid_type(&method_sig[index], len - index) == (len - index));
 453     }
 454   }
 455   return false;
 456 }
 457 
 458 bool SignatureVerifier::is_valid_type_signature(Symbol* sig) {
 459   const char* type_sig = (const char*)sig->bytes();
 460   ssize_t len = sig->utf8_length();
 461   return (type_sig != NULL && len >= 1 &&
 462           (is_valid_type(type_sig, len) == len));
 463 }
 464 
 465 // Checks to see if the type (not to go beyond 'limit') refers to a valid type.
 466 // Returns -1 if it is not, or the index of the next character that is not part
 467 // of the type.  The type encoding may end before 'limit' and that's ok.
 468 ssize_t SignatureVerifier::is_valid_type(const char* type, ssize_t limit) {
 469   ssize_t index = 0;
 470 
 471   // Iterate over any number of array dimensions
 472   while (index < limit && type[index] == JVM_SIGNATURE_ARRAY) ++index;
 473   if (index >= limit) {
 474     return -1;
 475   }
 476   switch (type[index]) {
 477     case JVM_SIGNATURE_BYTE:
 478     case JVM_SIGNATURE_CHAR:
 479     case JVM_SIGNATURE_DOUBLE:
 480     case JVM_SIGNATURE_FLOAT:
 481     case JVM_SIGNATURE_INT:
 482     case JVM_SIGNATURE_LONG:
 483     case JVM_SIGNATURE_SHORT:
 484     case JVM_SIGNATURE_BOOLEAN:
 485     case JVM_SIGNATURE_VOID:
 486       return index + 1;
 487     case JVM_SIGNATURE_CLASS:
 488       for (index = index + 1; index < limit; ++index) {
 489         char c = type[index];
 490         switch (c) {
 491           case JVM_SIGNATURE_ENDCLASS:
 492             return index + 1;
 493           case '\0': case JVM_SIGNATURE_DOT: case JVM_SIGNATURE_ARRAY:
 494             return -1;
 495           default: ; // fall through
 496         }
 497       }
 498       // fall through
 499     default: ; // fall through
 500   }
 501   return -1;
 502 }
 503 #endif // ASSERT