1 /* 2 * Copyright (c) 1997, 2023, 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 "asm/assembler.hpp" 27 #include "classfile/symbolTable.hpp" 28 #include "classfile/systemDictionary.hpp" 29 #include "classfile/vmSymbols.hpp" 30 #include "memory/oopFactory.hpp" 31 #include "memory/resourceArea.hpp" 32 #include "memory/universe.hpp" 33 #include "oops/instanceKlass.hpp" 34 #include "oops/klass.inline.hpp" 35 #include "oops/oop.inline.hpp" 36 #include "oops/symbol.hpp" 37 #include "oops/typeArrayKlass.hpp" 38 #include "oops/inlineKlass.inline.hpp" 39 #include "runtime/fieldDescriptor.inline.hpp" 40 #include "runtime/handles.inline.hpp" 41 #include "runtime/interfaceSupport.inline.hpp" 42 #include "runtime/safepointVerifiers.hpp" 43 #include "runtime/sharedRuntime.hpp" 44 #include "runtime/signature.hpp" 45 #include "runtime/sharedRuntime.hpp" 46 47 // Implementation of SignatureIterator 48 49 // Signature syntax: 50 // 51 // Signature = "(" {Parameter} ")" ReturnType. 52 // Parameter = FieldType. 53 // ReturnType = FieldType | "V". 54 // FieldType = "B" | "C" | "D" | "F" | "I" | "J" | "S" | "Z" | "L" ClassName ";" | "Q" ValueClassName ";" | "[" FieldType. 55 // ClassName = string. 56 57 // The ClassName string can be any JVM-style UTF8 string except: 58 // - an empty string (the empty string is never a name of any kind) 59 // - a string which begins or ends with slash '/' (the package separator) 60 // - a string which contains adjacent slashes '//' (no empty package names) 61 // - a string which contains a semicolon ';' (the end-delimiter) 62 // - a string which contains a left bracket '[' (the array marker) 63 // - a string which contains a dot '.' (the external package separator) 64 // 65 // Other "meta-looking" characters, such as '(' and '<' and '+', 66 // are perfectly legitimate within a class name, for the JVM. 67 // Class names which contain double slashes ('a//b') and non-initial 68 // brackets ('a[b]') are reserved for possible enrichment of the 69 // type language. 70 71 void SignatureIterator::set_fingerprint(fingerprint_t fingerprint) { 72 if (!fp_is_valid(fingerprint)) { 73 _fingerprint = fingerprint; 74 _return_type = T_ILLEGAL; 75 } else if (fingerprint != _fingerprint) { 76 assert(_fingerprint == zero_fingerprint(), "consistent fingerprint values"); 77 _fingerprint = fingerprint; 78 _return_type = fp_return_type(fingerprint); 79 } 80 } 81 82 BasicType SignatureIterator::return_type() { 83 if (_return_type == T_ILLEGAL) { 84 SignatureStream ss(_signature); 85 ss.skip_to_return_type(); 86 _return_type = ss.type(); 87 assert(_return_type != T_ILLEGAL, "illegal return type"); 88 } 89 return _return_type; 90 } 91 92 bool SignatureIterator::fp_is_valid_type(BasicType type, bool for_return_type) { 93 assert(type != (BasicType)fp_parameters_done, "fingerprint is incorrectly at done"); 94 assert(((int)type & ~fp_parameter_feature_mask) == 0, "fingerprint feature mask yielded non-zero value"); 95 return (is_java_primitive(type) || 96 is_reference_type(type) || 97 (for_return_type && type == T_VOID)); 98 } 99 100 ArgumentSizeComputer::ArgumentSizeComputer(Symbol* signature) 101 : SignatureIterator(signature) 102 { 103 _size = 0; 104 do_parameters_on(this); // non-virtual template execution 105 } 106 107 ArgumentCount::ArgumentCount(Symbol* signature) 108 : SignatureIterator(signature) 109 { 110 _size = 0; 111 do_parameters_on(this); // non-virtual template execution 112 } 113 114 ReferenceArgumentCount::ReferenceArgumentCount(Symbol* signature) 115 : SignatureIterator(signature) 116 { 117 _refs = 0; 118 do_parameters_on(this); // non-virtual template execution 119 } 120 121 #if !defined(_LP64) || defined(ZERO) || defined(ASSERT) 122 static int compute_num_stack_arg_slots(Symbol* signature, int sizeargs, bool is_static) { 123 ResourceMark rm; 124 BasicType* sig_bt = NEW_RESOURCE_ARRAY(BasicType, sizeargs); 125 VMRegPair* regs = NEW_RESOURCE_ARRAY(VMRegPair, sizeargs); 126 127 int sig_index = 0; 128 if (!is_static) { 129 sig_bt[sig_index++] = T_OBJECT; // 'this' 130 } 131 for (SignatureStream ss(signature); !ss.at_return_type(); ss.next()) { 132 BasicType t = ss.type(); 133 assert(type2size[t] == 1 || type2size[t] == 2, "size is 1 or 2"); 134 sig_bt[sig_index++] = t; 135 if (type2size[t] == 2) { 136 sig_bt[sig_index++] = T_VOID; 137 } 138 } 139 assert(sig_index == sizeargs, "sig_index: %d sizeargs: %d", sig_index, sizeargs); 140 141 return SharedRuntime::java_calling_convention(sig_bt, regs, sizeargs); 142 } 143 #endif 144 145 void Fingerprinter::compute_fingerprint_and_return_type(bool static_flag) { 146 // See if we fingerprinted this method already 147 if (_method != nullptr) { 148 assert(!static_flag, "must not be passed by caller"); 149 static_flag = _method->is_static(); 150 _fingerprint = _method->constMethod()->fingerprint(); 151 152 if (_fingerprint != zero_fingerprint()) { 153 _return_type = _method->result_type(); 154 assert(is_java_type(_return_type), "return type must be a java type"); 155 return; 156 } 157 158 if (_method->size_of_parameters() > fp_max_size_of_parameters) { 159 _fingerprint = overflow_fingerprint(); 160 _method->constMethod()->set_fingerprint(_fingerprint); 161 // as long as we are here compute the return type: 162 _return_type = ResultTypeFinder(_method->signature()).type(); 163 assert(is_java_type(_return_type), "return type must be a java type"); 164 return; 165 } 166 } 167 168 // Note: This will always take the slow path, since _fp==zero_fp. 169 initialize_accumulator(); 170 initialize_calling_convention(static_flag); 171 do_parameters_on(this); 172 assert(fp_is_valid_type(_return_type, true), "bad result type"); 173 174 // Fill in the return type and static bits: 175 _accumulator |= _return_type << fp_static_feature_size; 176 if (static_flag) { 177 _accumulator |= fp_is_static_bit; 178 } else { 179 _param_size += 1; // this is the convention for Method::compute_size_of_parameters 180 } 181 182 #if defined(_LP64) && !defined(ZERO) 183 _stack_arg_slots = align_up(_stack_arg_slots, 2); 184 #ifdef ASSERT 185 int dbg_stack_arg_slots = compute_num_stack_arg_slots(_signature, _param_size, static_flag); 186 assert(_stack_arg_slots == dbg_stack_arg_slots, "fingerprinter: %d full: %d", _stack_arg_slots, dbg_stack_arg_slots); 187 #endif 188 #else 189 // Fallback: computed _stack_arg_slots is unreliable, compute directly. 190 _stack_arg_slots = compute_num_stack_arg_slots(_signature, _param_size, static_flag); 191 #endif 192 193 // Detect overflow. (We counted _param_size correctly.) 194 if (_method == nullptr && _param_size > fp_max_size_of_parameters) { 195 // We did a one-pass computation of argument size, return type, 196 // and fingerprint. 197 _fingerprint = overflow_fingerprint(); 198 return; 199 } 200 201 assert(_shift_count < BitsPerLong, 202 "shift count overflow %d (%d vs. %d): %s", 203 _shift_count, _param_size, fp_max_size_of_parameters, 204 _signature->as_C_string()); 205 assert((_accumulator >> _shift_count) == fp_parameters_done, "must be zero"); 206 207 // This is the result, along with _return_type: 208 _fingerprint = _accumulator; 209 210 // Cache the result on the method itself: 211 if (_method != nullptr) { 212 _method->constMethod()->set_fingerprint(_fingerprint); 213 } 214 } 215 216 void Fingerprinter::initialize_calling_convention(bool static_flag) { 217 _int_args = 0; 218 _fp_args = 0; 219 220 if (!static_flag) { // `this` takes up an int register 221 _int_args++; 222 } 223 } 224 225 void Fingerprinter::do_type_calling_convention(BasicType type) { 226 // We compute the number of slots for stack-passed arguments in compiled calls. 227 // TODO: SharedRuntime::java_calling_convention is the shared code that knows all details 228 // about the platform-specific calling conventions. This method tries to compute the stack 229 // args number... poorly, at least for 32-bit ports and for zero. Current code has the fallback 230 // that recomputes the stack args number from SharedRuntime::java_calling_convention. 231 #if defined(_LP64) && !defined(ZERO) 232 switch (type) { 233 case T_VOID: 234 break; 235 case T_BOOLEAN: 236 case T_CHAR: 237 case T_BYTE: 238 case T_SHORT: 239 case T_INT: 240 #if defined(PPC64) || defined(S390) 241 if (_int_args < Argument::n_int_register_parameters_j) { 242 _int_args++; 243 } else { 244 _stack_arg_slots += 1; 245 } 246 break; 247 #endif // defined(PPC64) || defined(S390) 248 case T_LONG: 249 case T_OBJECT: 250 case T_ARRAY: 251 case T_ADDRESS: 252 if (_int_args < Argument::n_int_register_parameters_j) { 253 _int_args++; 254 } else { 255 PPC64_ONLY(_stack_arg_slots = align_up(_stack_arg_slots, 2)); 256 S390_ONLY(_stack_arg_slots = align_up(_stack_arg_slots, 2)); 257 _stack_arg_slots += 2; 258 } 259 break; 260 case T_FLOAT: 261 #if defined(PPC64) || defined(S390) 262 if (_fp_args < Argument::n_float_register_parameters_j) { 263 _fp_args++; 264 } else { 265 _stack_arg_slots += 1; 266 } 267 break; 268 #endif // defined(PPC64) || defined(S390) 269 case T_DOUBLE: 270 if (_fp_args < Argument::n_float_register_parameters_j) { 271 _fp_args++; 272 } else { 273 PPC64_ONLY(_stack_arg_slots = align_up(_stack_arg_slots, 2)); 274 S390_ONLY(_stack_arg_slots = align_up(_stack_arg_slots, 2)); 275 _stack_arg_slots += 2; 276 } 277 break; 278 default: 279 ShouldNotReachHere(); 280 break; 281 } 282 #endif 283 } 284 285 // Implementation of SignatureStream 286 287 static inline BasicType decode_signature_char(int ch) { 288 switch (ch) { 289 #define EACH_SIG(ch, bt, ignore) \ 290 case ch: return bt; 291 SIGNATURE_TYPES_DO(EACH_SIG, ignore) 292 #undef EACH_SIG 293 } 294 return (BasicType)0; 295 } 296 297 SignatureStream::SignatureStream(const Symbol* signature, 298 bool is_method) { 299 assert(!is_method || signature->starts_with(JVM_SIGNATURE_FUNC), 300 "method signature required"); 301 _signature = signature; 302 _limit = signature->utf8_length(); 303 int oz = (is_method ? _s_method : _s_field); 304 _state = oz; 305 _begin = _end = oz; // skip first '(' in method signatures 306 _array_prefix = 0; // just for definiteness 307 308 // assigning java/lang/Object to _previous_name means we can 309 // avoid a number of null checks in the parser 310 _previous_name = vmSymbols::java_lang_Object(); 311 _names = nullptr; 312 next(); 313 } 314 315 SignatureStream::~SignatureStream() { 316 if (_previous_name == vmSymbols::java_lang_Object()) { 317 // no names were created 318 assert(_names == nullptr, "_names unexpectedly created"); 319 return; 320 } 321 322 // decrement refcount for names created during signature parsing 323 _previous_name->decrement_refcount(); 324 if (_names != nullptr) { 325 for (int i = 0; i < _names->length(); i++) { 326 _names->at(i)->decrement_refcount(); 327 } 328 } 329 } 330 331 inline int SignatureStream::scan_type(BasicType type) { 332 const u1* base = _signature->bytes(); 333 int end = _end; 334 int limit = _limit; 335 const u1* tem; 336 switch (type) { 337 case T_OBJECT: 338 tem = (const u1*) memchr(&base[end], JVM_SIGNATURE_ENDCLASS, limit - end); 339 return (tem == nullptr ? limit : pointer_delta_as_int(tem + 1, base)); 340 341 case T_ARRAY: 342 while ((end < limit) && ((char)base[end] == JVM_SIGNATURE_ARRAY)) { end++; } 343 // If we discovered only the string of '[', this means something is wrong. 344 if (end >= limit) { 345 assert(false, "Invalid type detected"); 346 return limit; 347 } 348 _array_prefix = end - _end; // number of '[' chars just skipped 349 if (Signature::has_envelope(base[end])) { 350 tem = (const u1 *) memchr(&base[end], JVM_SIGNATURE_ENDCLASS, limit - end); 351 return (tem == nullptr ? limit : pointer_delta_as_int(tem + 1, base)); 352 } 353 // Skipping over a single character for a primitive type. 354 assert(is_java_primitive(decode_signature_char(base[end])), "only primitives expected"); 355 return end + 1; 356 357 default: 358 // Skipping over a single character for a primitive type (or void). 359 assert(!is_reference_type(type), "only primitives or void expected"); 360 return end + 1; 361 } 362 } 363 364 void SignatureStream::next() { 365 const Symbol* sig = _signature; 366 int len = _limit; 367 if (_end >= len) { set_done(); return; } 368 _begin = _end; 369 int ch = sig->char_at(_begin); 370 if (ch == JVM_SIGNATURE_ENDFUNC) { 371 assert(_state == _s_method, "must be in method"); 372 _state = _s_method_return; 373 _begin = ++_end; 374 if (_end >= len) { set_done(); return; } 375 ch = sig->char_at(_begin); 376 } 377 BasicType bt = decode_signature_char(ch); 378 assert(ch == type2char(bt), "bad signature char %c/%d", ch, ch); 379 _type = bt; 380 _end = scan_type(bt); 381 } 382 383 int SignatureStream::skip_whole_array_prefix() { 384 assert(_type == T_ARRAY, "must be"); 385 386 // we are stripping all levels of T_ARRAY, 387 // so we must decode the next character 388 int whole_array_prefix = _array_prefix; 389 int new_begin = _begin + whole_array_prefix; 390 _begin = new_begin; 391 int ch = _signature->char_at(new_begin); 392 BasicType bt = decode_signature_char(ch); 393 assert(ch == type2char(bt), "bad signature char %c/%d", ch, ch); 394 _type = bt; 395 assert(bt != T_VOID && bt != T_ARRAY, "bad signature type"); 396 // Don't bother to re-scan, since it won't change the value of _end. 397 return whole_array_prefix; 398 } 399 400 bool Signature::is_valid_array_signature(const Symbol* sig) { 401 assert(sig->utf8_length() > 1, "this should already have been checked"); 402 assert(sig->char_at(0) == JVM_SIGNATURE_ARRAY, "this should already have been checked"); 403 // The first character is already checked 404 int i = 1; 405 int len = sig->utf8_length(); 406 // First skip all '['s 407 while(i < len - 1 && sig->char_at(i) == JVM_SIGNATURE_ARRAY) i++; 408 409 // Check type 410 switch(sig->char_at(i)) { 411 case JVM_SIGNATURE_BYTE: 412 case JVM_SIGNATURE_CHAR: 413 case JVM_SIGNATURE_DOUBLE: 414 case JVM_SIGNATURE_FLOAT: 415 case JVM_SIGNATURE_INT: 416 case JVM_SIGNATURE_LONG: 417 case JVM_SIGNATURE_SHORT: 418 case JVM_SIGNATURE_BOOLEAN: 419 // If it is an array, the type is the last character 420 return (i + 1 == len); 421 case JVM_SIGNATURE_CLASS: 422 // If it is an object, the last character must be a ';' 423 return sig->char_at(len - 1) == JVM_SIGNATURE_ENDCLASS; 424 } 425 return false; 426 } 427 428 BasicType Signature::basic_type(int ch) { 429 BasicType btcode = decode_signature_char(ch); 430 if (btcode == 0) return T_ILLEGAL; 431 return btcode; 432 } 433 434 Symbol* Signature::strip_envelope(const Symbol* signature) { 435 assert(has_envelope(signature), "precondition"); 436 return SymbolTable::new_symbol((char*) signature->bytes() + 1, 437 signature->utf8_length() - 2); 438 } 439 440 static const int jl_len = 10, object_len = 6, jl_object_len = jl_len + object_len; 441 static const char jl_str[] = "java/lang/"; 442 443 #ifdef ASSERT 444 static bool signature_symbols_sane() { 445 static bool done; 446 if (done) return true; 447 done = true; 448 // test some tense code that looks for common symbol names: 449 assert(vmSymbols::java_lang_Object()->utf8_length() == jl_object_len && 450 vmSymbols::java_lang_Object()->starts_with(jl_str, jl_len) && 451 vmSymbols::java_lang_Object()->ends_with("Object", object_len) && 452 vmSymbols::java_lang_Object()->is_permanent() && 453 vmSymbols::java_lang_String()->utf8_length() == jl_object_len && 454 vmSymbols::java_lang_String()->starts_with(jl_str, jl_len) && 455 vmSymbols::java_lang_String()->ends_with("String", object_len) && 456 vmSymbols::java_lang_String()->is_permanent(), 457 "sanity"); 458 return true; 459 } 460 #endif //ASSERT 461 462 // returns a symbol; the caller is responsible for decrementing it 463 Symbol* SignatureStream::find_symbol() { 464 // Create a symbol from for string _begin _end 465 int begin = raw_symbol_begin(); 466 int end = raw_symbol_end(); 467 468 const char* symbol_chars = (const char*)_signature->base() + begin; 469 int len = end - begin; 470 471 // Quick check for common symbols in signatures 472 assert(signature_symbols_sane(), "incorrect signature sanity check"); 473 if (len == jl_object_len && 474 memcmp(symbol_chars, jl_str, jl_len) == 0) { 475 if (memcmp("String", symbol_chars + jl_len, object_len) == 0) { 476 return vmSymbols::java_lang_String(); 477 } else if (memcmp("Object", symbol_chars + jl_len, object_len) == 0) { 478 return vmSymbols::java_lang_Object(); 479 } 480 } 481 482 Symbol* name = _previous_name; 483 if (name->equals(symbol_chars, len)) { 484 return name; 485 } 486 487 // Save names for cleaning up reference count at the end of 488 // SignatureStream scope. 489 name = SymbolTable::new_symbol(symbol_chars, len); 490 491 // Only allocate the GrowableArray for the _names buffer if more than 492 // one name is being processed in the signature. 493 if (!_previous_name->is_permanent()) { 494 if (_names == nullptr) { 495 _names = new GrowableArray<Symbol*>(10); 496 } 497 _names->push(_previous_name); 498 } 499 _previous_name = name; 500 return name; 501 } 502 503 InlineKlass* SignatureStream::as_inline_klass(InstanceKlass* holder) { 504 ThreadInVMfromUnknown tiv; 505 JavaThread* THREAD = JavaThread::current(); 506 HandleMark hm(THREAD); 507 Handle class_loader(THREAD, holder->class_loader()); 508 Handle protection_domain(THREAD, holder->protection_domain()); 509 Klass* k = as_klass(class_loader, protection_domain, SignatureStream::CachedOrNull, THREAD); 510 assert(!HAS_PENDING_EXCEPTION, "Should never throw"); 511 if (k != nullptr && k->is_inline_klass()) { 512 return InlineKlass::cast(k); 513 } else { 514 return nullptr; 515 } 516 } 517 518 Klass* SignatureStream::as_klass(Handle class_loader, Handle protection_domain, 519 FailureMode failure_mode, TRAPS) { 520 if (!is_reference()) { 521 return nullptr; 522 } 523 Symbol* name = as_symbol(); 524 Klass* k = nullptr; 525 if (failure_mode == ReturnNull) { 526 // Note: SD::resolve_or_null returns null for most failure modes, 527 // but not all. Circularity errors, invalid PDs, etc., throw. 528 k = SystemDictionary::resolve_or_null(name, class_loader, protection_domain, CHECK_NULL); 529 } else if (failure_mode == CachedOrNull) { 530 NoSafepointVerifier nsv; // no loading, now, we mean it! 531 assert(!HAS_PENDING_EXCEPTION, ""); 532 k = SystemDictionary::find_instance_klass(THREAD, name, class_loader, protection_domain); 533 // SD::find does not trigger loading, so there should be no throws 534 // Still, bad things can happen, so we CHECK_NULL and ask callers 535 // to do likewise. 536 return k; 537 } else { 538 // The only remaining failure mode is NCDFError. 539 // The test here allows for an additional mode CNFException 540 // if callers need to request the reflective error instead. 541 bool throw_error = (failure_mode == NCDFError); 542 k = SystemDictionary::resolve_or_fail(name, class_loader, protection_domain, throw_error, CHECK_NULL); 543 } 544 545 return k; 546 } 547 548 oop SignatureStream::as_java_mirror(Handle class_loader, Handle protection_domain, 549 FailureMode failure_mode, TRAPS) { 550 if (!is_reference()) { 551 return Universe::java_mirror(type()); 552 } 553 Klass* klass = as_klass(class_loader, protection_domain, failure_mode, CHECK_NULL); 554 if (klass == nullptr) { 555 return nullptr; 556 } 557 return klass->java_mirror(); 558 } 559 560 void SignatureStream::skip_to_return_type() { 561 while (!at_return_type()) { 562 next(); 563 } 564 } 565 566 ResolvingSignatureStream::ResolvingSignatureStream(Symbol* signature, 567 Handle class_loader, 568 Handle protection_domain, 569 bool is_method) 570 : SignatureStream(signature, is_method), 571 _class_loader(class_loader), _protection_domain(protection_domain) 572 { 573 initialize_load_origin(nullptr); 574 } 575 576 ResolvingSignatureStream::ResolvingSignatureStream(Symbol* signature, Klass* load_origin, bool is_method) 577 : SignatureStream(signature, is_method) 578 { 579 assert(load_origin != nullptr, ""); 580 initialize_load_origin(load_origin); 581 } 582 583 ResolvingSignatureStream::ResolvingSignatureStream(const Method* method) 584 : SignatureStream(method->signature(), true) 585 { 586 initialize_load_origin(method->method_holder()); 587 } 588 589 void ResolvingSignatureStream::cache_handles() { 590 assert(_load_origin != nullptr, ""); 591 JavaThread* current = JavaThread::current(); 592 _class_loader = Handle(current, _load_origin->class_loader()); 593 _protection_domain = Handle(current, _load_origin->protection_domain()); 594 } 595 596 #ifdef ASSERT 597 extern bool signature_constants_sane(); // called from basic_types_init() 598 599 bool signature_constants_sane() { 600 // for the lookup table, test every 8-bit code point, and then some: 601 for (int i = -256; i <= 256; i++) { 602 int btcode = 0; 603 switch (i) { 604 #define EACH_SIG(ch, bt, ignore) \ 605 case ch: { btcode = bt; break; } 606 SIGNATURE_TYPES_DO(EACH_SIG, ignore) 607 #undef EACH_SIG 608 } 609 int btc = decode_signature_char(i); 610 assert(btc == btcode, "misconfigured table: %d => %d not %d", i, btc, btcode); 611 } 612 return true; 613 } 614 615 bool SignatureVerifier::is_valid_method_signature(const Symbol* sig) { 616 const char* method_sig = (const char*)sig->bytes(); 617 ssize_t len = sig->utf8_length(); 618 ssize_t index = 0; 619 if (method_sig != nullptr && len > 1 && method_sig[index] == JVM_SIGNATURE_FUNC) { 620 ++index; 621 while (index < len && method_sig[index] != JVM_SIGNATURE_ENDFUNC) { 622 ssize_t res = is_valid_type(&method_sig[index], len - index); 623 if (res == -1) { 624 return false; 625 } else { 626 index += res; 627 } 628 } 629 if (index < len && method_sig[index] == JVM_SIGNATURE_ENDFUNC) { 630 // check the return type 631 ++index; 632 return (is_valid_type(&method_sig[index], len - index) == (len - index)); 633 } 634 } 635 return false; 636 } 637 638 bool SignatureVerifier::is_valid_type_signature(const Symbol* sig) { 639 const char* type_sig = (const char*)sig->bytes(); 640 ssize_t len = sig->utf8_length(); 641 return (type_sig != nullptr && len >= 1 && 642 (is_valid_type(type_sig, len) == len)); 643 } 644 645 // Checks to see if the type (not to go beyond 'limit') refers to a valid type. 646 // Returns -1 if it is not, or the index of the next character that is not part 647 // of the type. The type encoding may end before 'limit' and that's ok. 648 ssize_t SignatureVerifier::is_valid_type(const char* type, ssize_t limit) { 649 ssize_t index = 0; 650 651 // Iterate over any number of array dimensions 652 while (index < limit && type[index] == JVM_SIGNATURE_ARRAY) ++index; 653 if (index >= limit) { 654 return -1; 655 } 656 switch (type[index]) { 657 case JVM_SIGNATURE_BYTE: 658 case JVM_SIGNATURE_CHAR: 659 case JVM_SIGNATURE_FLOAT: 660 case JVM_SIGNATURE_DOUBLE: 661 case JVM_SIGNATURE_INT: 662 case JVM_SIGNATURE_LONG: 663 case JVM_SIGNATURE_SHORT: 664 case JVM_SIGNATURE_BOOLEAN: 665 case JVM_SIGNATURE_VOID: 666 return index + 1; 667 case JVM_SIGNATURE_CLASS: 668 for (index = index + 1; index < limit; ++index) { 669 char c = type[index]; 670 switch (c) { 671 case JVM_SIGNATURE_ENDCLASS: 672 return index + 1; 673 case '\0': case JVM_SIGNATURE_DOT: case JVM_SIGNATURE_ARRAY: 674 return -1; 675 default: ; // fall through 676 } 677 } 678 // fall through 679 default: ; // fall through 680 } 681 return -1; 682 } 683 684 #endif // ASSERT 685 686 // Adds an argument to the signature 687 void SigEntry::add_entry(GrowableArray<SigEntry>* sig, BasicType bt, Symbol* symbol, int offset) { 688 sig->append(SigEntry(bt, offset, symbol)); 689 if (bt == T_LONG || bt == T_DOUBLE) { 690 sig->append(SigEntry(T_VOID, offset, symbol)); // Longs and doubles take two stack slots 691 } 692 } 693 694 // Returns true if the argument at index 'i' is not an inline type delimiter 695 bool SigEntry::skip_value_delimiters(const GrowableArray<SigEntry>* sig, int i) { 696 return (sig->at(i)._bt != T_METADATA && 697 (sig->at(i)._bt != T_VOID || sig->at(i-1)._bt == T_LONG || sig->at(i-1)._bt == T_DOUBLE)); 698 } 699 700 // Fill basic type array from signature array 701 int SigEntry::fill_sig_bt(const GrowableArray<SigEntry>* sig, BasicType* sig_bt) { 702 int count = 0; 703 for (int i = 0; i < sig->length(); i++) { 704 if (skip_value_delimiters(sig, i)) { 705 sig_bt[count++] = sig->at(i)._bt; 706 } 707 } 708 return count; 709 } 710 711 // Create a temporary symbol from the signature array 712 TempNewSymbol SigEntry::create_symbol(const GrowableArray<SigEntry>* sig) { 713 ResourceMark rm; 714 int length = sig->length(); 715 char* sig_str = NEW_RESOURCE_ARRAY(char, 2*length + 3); 716 int idx = 0; 717 sig_str[idx++] = '('; 718 for (int i = 0; i < length; i++) { 719 BasicType bt = sig->at(i)._bt; 720 if (bt == T_METADATA || bt == T_VOID) { 721 // Ignore 722 } else { 723 if (bt == T_ARRAY) { 724 bt = T_OBJECT; // We don't know the element type, treat as Object 725 } 726 sig_str[idx++] = type2char(bt); 727 if (bt == T_OBJECT) { 728 sig_str[idx++] = ';'; 729 } 730 } 731 } 732 sig_str[idx++] = ')'; 733 // Add a dummy return type. It won't be used but SignatureStream needs it. 734 sig_str[idx++] = 'V'; 735 sig_str[idx++] = '\0'; 736 return SymbolTable::new_symbol(sig_str); 737 }