1 /* 2 * Copyright (c) 1997, 2013, 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 #ifndef SHARE_VM_CODE_RELOCINFO_HPP 26 #define SHARE_VM_CODE_RELOCINFO_HPP 27 28 #include "memory/allocation.hpp" 29 #include "utilities/top.hpp" 30 31 class NativeMovConstReg; 32 33 // Types in this file: 34 // relocInfo 35 // One element of an array of halfwords encoding compressed relocations. 36 // Also, the source of relocation types (relocInfo::oop_type, ...). 37 // Relocation 38 // A flyweight object representing a single relocation. 39 // It is fully unpacked from the compressed relocation array. 40 // metadata_Relocation, ... (subclasses of Relocation) 41 // The location of some type-specific operations (metadata_addr, ...). 42 // Also, the source of relocation specs (metadata_Relocation::spec, ...). 43 // oop_Relocation, ... (subclasses of Relocation) 44 // oops in the code stream (strings, class loaders) 45 // Also, the source of relocation specs (oop_Relocation::spec, ...). 46 // RelocationHolder 47 // A ValueObj type which acts as a union holding a Relocation object. 48 // Represents a relocation spec passed into a CodeBuffer during assembly. 49 // RelocIterator 50 // A StackObj which iterates over the relocations associated with 51 // a range of code addresses. Can be used to operate a copy of code. 52 // BoundRelocation 53 // An _internal_ type shared by packers and unpackers of relocations. 54 // It pastes together a RelocationHolder with some pointers into 55 // code and relocInfo streams. 56 57 58 // Notes on relocType: 59 // 60 // These hold enough information to read or write a value embedded in 61 // the instructions of an CodeBlob. They're used to update: 62 // 63 // 1) embedded oops (isOop() == true) 64 // 2) inline caches (isIC() == true) 65 // 3) runtime calls (isRuntimeCall() == true) 66 // 4) internal word ref (isInternalWord() == true) 67 // 5) external word ref (isExternalWord() == true) 68 // 69 // when objects move (GC) or if code moves (compacting the code heap). 70 // They are also used to patch the code (if a call site must change) 71 // 72 // A relocInfo is represented in 16 bits: 73 // 4 bits indicating the relocation type 74 // 12 bits indicating the offset from the previous relocInfo address 75 // 76 // The offsets accumulate along the relocInfo stream to encode the 77 // address within the CodeBlob, which is named RelocIterator::addr(). 78 // The address of a particular relocInfo always points to the first 79 // byte of the relevant instruction (and not to any of its subfields 80 // or embedded immediate constants). 81 // 82 // The offset value is scaled appropriately for the target machine. 83 // (See relocInfo_<arch>.hpp for the offset scaling.) 84 // 85 // On some machines, there may also be a "format" field which may provide 86 // additional information about the format of the instruction stream 87 // at the corresponding code address. The format value is usually zero. 88 // Any machine (such as Intel) whose instructions can sometimes contain 89 // more than one relocatable constant needs format codes to distinguish 90 // which operand goes with a given relocation. 91 // 92 // If the target machine needs N format bits, the offset has 12-N bits, 93 // the format is encoded between the offset and the type, and the 94 // relocInfo_<arch>.hpp file has manifest constants for the format codes. 95 // 96 // If the type is "data_prefix_tag" then the offset bits are further encoded, 97 // and in fact represent not a code-stream offset but some inline data. 98 // The data takes the form of a counted sequence of halfwords, which 99 // precedes the actual relocation record. (Clients never see it directly.) 100 // The interpetation of this extra data depends on the relocation type. 101 // 102 // On machines that have 32-bit immediate fields, there is usually 103 // little need for relocation "prefix" data, because the instruction stream 104 // is a perfectly reasonable place to store the value. On machines in 105 // which 32-bit values must be "split" across instructions, the relocation 106 // data is the "true" specification of the value, which is then applied 107 // to some field of the instruction (22 or 13 bits, on SPARC). 108 // 109 // Whenever the location of the CodeBlob changes, any PC-relative 110 // relocations, and any internal_word_type relocations, must be reapplied. 111 // After the GC runs, oop_type relocations must be reapplied. 112 // 113 // 114 // Here are meanings of the types: 115 // 116 // relocInfo::none -- a filler record 117 // Value: none 118 // Instruction: The corresponding code address is ignored 119 // Data: Any data prefix and format code are ignored 120 // (This means that any relocInfo can be disabled by setting 121 // its type to none. See relocInfo::remove.) 122 // 123 // relocInfo::oop_type, relocInfo::metadata_type -- a reference to an oop or meta data 124 // Value: an oop, or else the address (handle) of an oop 125 // Instruction types: memory (load), set (load address) 126 // Data: [] an oop stored in 4 bytes of instruction 127 // [n] n is the index of an oop in the CodeBlob's oop pool 128 // [[N]n l] and l is a byte offset to be applied to the oop 129 // [Nn Ll] both index and offset may be 32 bits if necessary 130 // Here is a special hack, used only by the old compiler: 131 // [[N]n 00] the value is the __address__ of the nth oop in the pool 132 // (Note that the offset allows optimal references to class variables.) 133 // 134 // relocInfo::internal_word_type -- an address within the same CodeBlob 135 // relocInfo::section_word_type -- same, but can refer to another section 136 // Value: an address in the CodeBlob's code or constants section 137 // Instruction types: memory (load), set (load address) 138 // Data: [] stored in 4 bytes of instruction 139 // [[L]l] a relative offset (see [About Offsets] below) 140 // In the case of section_word_type, the offset is relative to a section 141 // base address, and the section number (e.g., SECT_INSTS) is encoded 142 // into the low two bits of the offset L. 143 // 144 // relocInfo::external_word_type -- a fixed address in the runtime system 145 // Value: an address 146 // Instruction types: memory (load), set (load address) 147 // Data: [] stored in 4 bytes of instruction 148 // [n] the index of a "well-known" stub (usual case on RISC) 149 // [Ll] a 32-bit address 150 // 151 // relocInfo::runtime_call_type -- a fixed subroutine in the runtime system 152 // Value: an address 153 // Instruction types: PC-relative call (or a PC-relative branch) 154 // Data: [] stored in 4 bytes of instruction 155 // 156 // relocInfo::static_call_type -- a static call 157 // Value: an CodeBlob, a stub, or a fixup routine 158 // Instruction types: a call 159 // Data: [] 160 // The identity of the callee is extracted from debugging information. 161 // //%note reloc_3 162 // 163 // relocInfo::virtual_call_type -- a virtual call site (which includes an inline 164 // cache) 165 // Value: an CodeBlob, a stub, the interpreter, or a fixup routine 166 // Instruction types: a call, plus some associated set-oop instructions 167 // Data: [] the associated set-oops are adjacent to the call 168 // [n] n is a relative offset to the first set-oop 169 // [[N]n l] and l is a limit within which the set-oops occur 170 // [Nn Ll] both n and l may be 32 bits if necessary 171 // The identity of the callee is extracted from debugging information. 172 // 173 // relocInfo::opt_virtual_call_type -- a virtual call site that is statically bound 174 // 175 // Same info as a static_call_type. We use a special type, so the handling of 176 // virtuals and statics are separated. 177 // 178 // 179 // The offset n points to the first set-oop. (See [About Offsets] below.) 180 // In turn, the set-oop instruction specifies or contains an oop cell devoted 181 // exclusively to the IC call, which can be patched along with the call. 182 // 183 // The locations of any other set-oops are found by searching the relocation 184 // information starting at the first set-oop, and continuing until all 185 // relocations up through l have been inspected. The value l is another 186 // relative offset. (Both n and l are relative to the call's first byte.) 187 // 188 // The limit l of the search is exclusive. However, if it points within 189 // the call (e.g., offset zero), it is adjusted to point after the call and 190 // any associated machine-specific delay slot. 191 // 192 // Since the offsets could be as wide as 32-bits, these conventions 193 // put no restrictions whatever upon code reorganization. 194 // 195 // The compiler is responsible for ensuring that transition from a clean 196 // state to a monomorphic compiled state is MP-safe. This implies that 197 // the system must respond well to intermediate states where a random 198 // subset of the set-oops has been correctly from the clean state 199 // upon entry to the VEP of the compiled method. In the case of a 200 // machine (Intel) with a single set-oop instruction, the 32-bit 201 // immediate field must not straddle a unit of memory coherence. 202 // //%note reloc_3 203 // 204 // relocInfo::static_stub_type -- an extra stub for each static_call_type 205 // Value: none 206 // Instruction types: a virtual call: { set_oop; jump; } 207 // Data: [[N]n] the offset of the associated static_call reloc 208 // This stub becomes the target of a static call which must be upgraded 209 // to a virtual call (because the callee is interpreted). 210 // See [About Offsets] below. 211 // //%note reloc_2 212 // 213 // For example: 214 // 215 // INSTRUCTIONS RELOC: TYPE PREFIX DATA 216 // ------------ ---- ----------- 217 // sethi %hi(myObject), R oop_type [n(myObject)] 218 // ld [R+%lo(myObject)+fldOffset], R2 oop_type [n(myObject) fldOffset] 219 // add R2, 1, R2 220 // st R2, [R+%lo(myObject)+fldOffset] oop_type [n(myObject) fldOffset] 221 //%note reloc_1 222 // 223 // This uses 4 instruction words, 8 relocation halfwords, 224 // and an entry (which is sharable) in the CodeBlob's oop pool, 225 // for a total of 36 bytes. 226 // 227 // Note that the compiler is responsible for ensuring the "fldOffset" when 228 // added to "%lo(myObject)" does not overflow the immediate fields of the 229 // memory instructions. 230 // 231 // 232 // [About Offsets] Relative offsets are supplied to this module as 233 // positive byte offsets, but they may be internally stored scaled 234 // and/or negated, depending on what is most compact for the target 235 // system. Since the object pointed to by the offset typically 236 // precedes the relocation address, it is profitable to store 237 // these negative offsets as positive numbers, but this decision 238 // is internal to the relocation information abstractions. 239 // 240 241 class Relocation; 242 class CodeBuffer; 243 class CodeSection; 244 class RelocIterator; 245 246 class relocInfo VALUE_OBJ_CLASS_SPEC { 247 friend class RelocIterator; 248 public: 249 enum relocType { 250 none = 0, // Used when no relocation should be generated 251 oop_type = 1, // embedded oop 252 virtual_call_type = 2, // a standard inline cache call for a virtual send 253 opt_virtual_call_type = 3, // a virtual call that has been statically bound (i.e., no IC cache) 254 static_call_type = 4, // a static send 255 static_stub_type = 5, // stub-entry for static send (takes care of interpreter case) 256 runtime_call_type = 6, // call to fixed external routine 257 external_word_type = 7, // reference to fixed external address 258 internal_word_type = 8, // reference within the current code blob 259 section_word_type = 9, // internal, but a cross-section reference 260 poll_type = 10, // polling instruction for safepoints 261 poll_return_type = 11, // polling instruction for safepoints at return 262 metadata_type = 12, // metadata that used to be oops 263 trampoline_stub_type = 13, // stub-entry for trampoline 264 yet_unused_type_1 = 14, // Still unused 265 data_prefix_tag = 15, // tag for a prefix (carries data arguments) 266 type_mask = 15 // A mask which selects only the above values 267 }; 268 269 protected: 270 unsigned short _value; 271 272 enum RawBitsToken { RAW_BITS }; 273 relocInfo(relocType type, RawBitsToken ignore, int bits) 274 : _value((type << nontype_width) + bits) { } 275 276 relocInfo(relocType type, RawBitsToken ignore, int off, int f) 277 : _value((type << nontype_width) + (off / (unsigned)offset_unit) + (f << offset_width)) { } 278 279 public: 280 // constructor 281 relocInfo(relocType type, int offset, int format = 0) 282 #ifndef ASSERT 283 { 284 (*this) = relocInfo(type, RAW_BITS, offset, format); 285 } 286 #else 287 // Put a bunch of assertions out-of-line. 288 ; 289 #endif 290 291 #define APPLY_TO_RELOCATIONS(visitor) \ 292 visitor(oop) \ 293 visitor(metadata) \ 294 visitor(virtual_call) \ 295 visitor(opt_virtual_call) \ 296 visitor(static_call) \ 297 visitor(static_stub) \ 298 visitor(runtime_call) \ 299 visitor(external_word) \ 300 visitor(internal_word) \ 301 visitor(poll) \ 302 visitor(poll_return) \ 303 visitor(section_word) \ 304 visitor(trampoline_stub) \ 305 306 307 public: 308 enum { 309 value_width = sizeof(unsigned short) * BitsPerByte, 310 type_width = 4, // == log2(type_mask+1) 311 nontype_width = value_width - type_width, 312 datalen_width = nontype_width-1, 313 datalen_tag = 1 << datalen_width, // or-ed into _value 314 datalen_limit = 1 << datalen_width, 315 datalen_mask = (1 << datalen_width)-1 316 }; 317 318 // accessors 319 public: 320 relocType type() const { return (relocType)((unsigned)_value >> nontype_width); } 321 int format() const { return format_mask==0? 0: format_mask & 322 ((unsigned)_value >> offset_width); } 323 int addr_offset() const { assert(!is_prefix(), "must have offset"); 324 return (_value & offset_mask)*offset_unit; } 325 326 protected: 327 const short* data() const { assert(is_datalen(), "must have data"); 328 return (const short*)(this + 1); } 329 int datalen() const { assert(is_datalen(), "must have data"); 330 return (_value & datalen_mask); } 331 int immediate() const { assert(is_immediate(), "must have immed"); 332 return (_value & datalen_mask); } 333 public: 334 static int addr_unit() { return offset_unit; } 335 static int offset_limit() { return (1 << offset_width) * offset_unit; } 336 337 void set_type(relocType type); 338 void set_format(int format); 339 340 void remove() { set_type(none); } 341 342 protected: 343 bool is_none() const { return type() == none; } 344 bool is_prefix() const { return type() == data_prefix_tag; } 345 bool is_datalen() const { assert(is_prefix(), "must be prefix"); 346 return (_value & datalen_tag) != 0; } 347 bool is_immediate() const { assert(is_prefix(), "must be prefix"); 348 return (_value & datalen_tag) == 0; } 349 350 public: 351 // Occasionally records of type relocInfo::none will appear in the stream. 352 // We do not bother to filter these out, but clients should ignore them. 353 // These records serve as "filler" in three ways: 354 // - to skip large spans of unrelocated code (this is rare) 355 // - to pad out the relocInfo array to the required oop alignment 356 // - to disable old relocation information which is no longer applicable 357 358 inline friend relocInfo filler_relocInfo(); 359 360 // Every non-prefix relocation may be preceded by at most one prefix, 361 // which supplies 1 or more halfwords of associated data. Conventionally, 362 // an int is represented by 0, 1, or 2 halfwords, depending on how 363 // many bits are required to represent the value. (In addition, 364 // if the sole halfword is a 10-bit unsigned number, it is made 365 // "immediate" in the prefix header word itself. This optimization 366 // is invisible outside this module.) 367 368 inline friend relocInfo prefix_relocInfo(int datalen); 369 370 protected: 371 // an immediate relocInfo optimizes a prefix with one 10-bit unsigned value 372 static relocInfo immediate_relocInfo(int data0) { 373 assert(fits_into_immediate(data0), "data0 in limits"); 374 return relocInfo(relocInfo::data_prefix_tag, RAW_BITS, data0); 375 } 376 static bool fits_into_immediate(int data0) { 377 return (data0 >= 0 && data0 < datalen_limit); 378 } 379 380 public: 381 // Support routines for compilers. 382 383 // This routine takes an infant relocInfo (unprefixed) and 384 // edits in its prefix, if any. It also updates dest.locs_end. 385 void initialize(CodeSection* dest, Relocation* reloc); 386 387 // This routine updates a prefix and returns the limit pointer. 388 // It tries to compress the prefix from 32 to 16 bits, and if 389 // successful returns a reduced "prefix_limit" pointer. 390 relocInfo* finish_prefix(short* prefix_limit); 391 392 // bit-packers for the data array: 393 394 // As it happens, the bytes within the shorts are ordered natively, 395 // but the shorts within the word are ordered big-endian. 396 // This is an arbitrary choice, made this way mainly to ease debugging. 397 static int data0_from_int(jint x) { return x >> value_width; } 398 static int data1_from_int(jint x) { return (short)x; } 399 static jint jint_from_data(short* data) { 400 return (data[0] << value_width) + (unsigned short)data[1]; 401 } 402 403 static jint short_data_at(int n, short* data, int datalen) { 404 return datalen > n ? data[n] : 0; 405 } 406 407 static jint jint_data_at(int n, short* data, int datalen) { 408 return datalen > n+1 ? jint_from_data(&data[n]) : short_data_at(n, data, datalen); 409 } 410 411 // Update methods for relocation information 412 // (since code is dynamically patched, we also need to dynamically update the relocation info) 413 // Both methods takes old_type, so it is able to performe sanity checks on the information removed. 414 static void change_reloc_info_for_address(RelocIterator *itr, address pc, relocType old_type, relocType new_type); 415 static void remove_reloc_info_for_address(RelocIterator *itr, address pc, relocType old_type); 416 417 // Machine dependent stuff 418 #ifdef TARGET_ARCH_x86 419 # include "relocInfo_x86.hpp" 420 #endif 421 #ifdef TARGET_ARCH_aarch64 422 # include "relocInfo_aarch64.hpp" 423 #endif 424 #ifdef TARGET_ARCH_sparc 425 # include "relocInfo_sparc.hpp" 426 #endif 427 #ifdef TARGET_ARCH_zero 428 # include "relocInfo_zero.hpp" 429 #endif 430 #ifdef TARGET_ARCH_arm 431 # include "relocInfo_arm.hpp" 432 #endif 433 #ifdef TARGET_ARCH_ppc 434 # include "relocInfo_ppc.hpp" 435 #endif 436 437 438 protected: 439 // Derived constant, based on format_width which is PD: 440 enum { 441 offset_width = nontype_width - format_width, 442 offset_mask = (1<<offset_width) - 1, 443 format_mask = (1<<format_width) - 1 444 }; 445 public: 446 enum { 447 // Conservatively large estimate of maximum length (in shorts) 448 // of any relocation record. 449 // Extended format is length prefix, data words, and tag/offset suffix. 450 length_limit = 1 + 1 + (3*BytesPerWord/BytesPerShort) + 1, 451 have_format = format_width > 0 452 }; 453 }; 454 455 #define FORWARD_DECLARE_EACH_CLASS(name) \ 456 class name##_Relocation; 457 APPLY_TO_RELOCATIONS(FORWARD_DECLARE_EACH_CLASS) 458 #undef FORWARD_DECLARE_EACH_CLASS 459 460 461 462 inline relocInfo filler_relocInfo() { 463 return relocInfo(relocInfo::none, relocInfo::offset_limit() - relocInfo::offset_unit); 464 } 465 466 inline relocInfo prefix_relocInfo(int datalen = 0) { 467 assert(relocInfo::fits_into_immediate(datalen), "datalen in limits"); 468 return relocInfo(relocInfo::data_prefix_tag, relocInfo::RAW_BITS, relocInfo::datalen_tag | datalen); 469 } 470 471 472 // Holder for flyweight relocation objects. 473 // Although the flyweight subclasses are of varying sizes, 474 // the holder is "one size fits all". 475 class RelocationHolder VALUE_OBJ_CLASS_SPEC { 476 friend class Relocation; 477 friend class CodeSection; 478 479 private: 480 // this preallocated memory must accommodate all subclasses of Relocation 481 // (this number is assertion-checked in Relocation::operator new) 482 enum { _relocbuf_size = 5 }; 483 void* _relocbuf[ _relocbuf_size ]; 484 485 public: 486 Relocation* reloc() const { return (Relocation*) &_relocbuf[0]; } 487 inline relocInfo::relocType type() const; 488 489 // Add a constant offset to a relocation. Helper for class Address. 490 RelocationHolder plus(int offset) const; 491 492 inline RelocationHolder(); // initializes type to none 493 494 inline RelocationHolder(Relocation* r); // make a copy 495 496 static const RelocationHolder none; 497 }; 498 499 // A RelocIterator iterates through the relocation information of a CodeBlob. 500 // It is a variable BoundRelocation which is able to take on successive 501 // values as it is advanced through a code stream. 502 // Usage: 503 // RelocIterator iter(nm); 504 // while (iter.next()) { 505 // iter.reloc()->some_operation(); 506 // } 507 // or: 508 // RelocIterator iter(nm); 509 // while (iter.next()) { 510 // switch (iter.type()) { 511 // case relocInfo::oop_type : 512 // case relocInfo::ic_type : 513 // case relocInfo::prim_type : 514 // case relocInfo::uncommon_type : 515 // case relocInfo::runtime_call_type : 516 // case relocInfo::internal_word_type: 517 // case relocInfo::external_word_type: 518 // ... 519 // } 520 // } 521 522 class RelocIterator : public StackObj { 523 enum { SECT_LIMIT = 3 }; // must be equal to CodeBuffer::SECT_LIMIT, checked in ctor 524 friend class Relocation; 525 friend class relocInfo; // for change_reloc_info_for_address only 526 typedef relocInfo::relocType relocType; 527 528 private: 529 address _limit; // stop producing relocations after this _addr 530 relocInfo* _current; // the current relocation information 531 relocInfo* _end; // end marker; we're done iterating when _current == _end 532 nmethod* _code; // compiled method containing _addr 533 address _addr; // instruction to which the relocation applies 534 short _databuf; // spare buffer for compressed data 535 short* _data; // pointer to the relocation's data 536 short _datalen; // number of halfwords in _data 537 char _format; // position within the instruction 538 539 // Base addresses needed to compute targets of section_word_type relocs. 540 address _section_start[SECT_LIMIT]; 541 address _section_end [SECT_LIMIT]; 542 543 void set_has_current(bool b) { 544 _datalen = !b ? -1 : 0; 545 debug_only(_data = NULL); 546 } 547 void set_current(relocInfo& ri) { 548 _current = &ri; 549 set_has_current(true); 550 } 551 552 RelocationHolder _rh; // where the current relocation is allocated 553 554 relocInfo* current() const { assert(has_current(), "must have current"); 555 return _current; } 556 557 void set_limits(address begin, address limit); 558 559 void advance_over_prefix(); // helper method 560 561 void initialize_misc(); 562 563 void initialize(nmethod* nm, address begin, address limit); 564 565 RelocIterator() { initialize_misc(); } 566 567 public: 568 // constructor 569 RelocIterator(nmethod* nm, address begin = NULL, address limit = NULL); 570 RelocIterator(CodeSection* cb, address begin = NULL, address limit = NULL); 571 572 // get next reloc info, return !eos 573 bool next() { 574 _current++; 575 assert(_current <= _end, "must not overrun relocInfo"); 576 if (_current == _end) { 577 set_has_current(false); 578 return false; 579 } 580 set_has_current(true); 581 582 if (_current->is_prefix()) { 583 advance_over_prefix(); 584 assert(!current()->is_prefix(), "only one prefix at a time"); 585 } 586 587 _addr += _current->addr_offset(); 588 589 if (_limit != NULL && _addr >= _limit) { 590 set_has_current(false); 591 return false; 592 } 593 594 if (relocInfo::have_format) _format = current()->format(); 595 return true; 596 } 597 598 // accessors 599 address limit() const { return _limit; } 600 void set_limit(address x); 601 relocType type() const { return current()->type(); } 602 int format() const { return (relocInfo::have_format) ? current()->format() : 0; } 603 address addr() const { return _addr; } 604 nmethod* code() const { return _code; } 605 short* data() const { return _data; } 606 int datalen() const { return _datalen; } 607 bool has_current() const { return _datalen >= 0; } 608 609 void set_addr(address addr) { _addr = addr; } 610 bool addr_in_const() const; 611 612 address section_start(int n) const { 613 assert(_section_start[n], "must be initialized"); 614 return _section_start[n]; 615 } 616 address section_end(int n) const { 617 assert(_section_end[n], "must be initialized"); 618 return _section_end[n]; 619 } 620 621 // The address points to the affected displacement part of the instruction. 622 // For RISC, this is just the whole instruction. 623 // For Intel, this is an unaligned 32-bit word. 624 625 // type-specific relocation accessors: oop_Relocation* oop_reloc(), etc. 626 #define EACH_TYPE(name) \ 627 inline name##_Relocation* name##_reloc(); 628 APPLY_TO_RELOCATIONS(EACH_TYPE) 629 #undef EACH_TYPE 630 // generic relocation accessor; switches on type to call the above 631 Relocation* reloc(); 632 633 // CodeBlob's have relocation indexes for faster random access: 634 static int locs_and_index_size(int code_size, int locs_size); 635 // Store an index into [dest_start+dest_count..dest_end). 636 // At dest_start[0..dest_count] is the actual relocation information. 637 // Everything else up to dest_end is free space for the index. 638 static void create_index(relocInfo* dest_begin, int dest_count, relocInfo* dest_end); 639 640 #ifndef PRODUCT 641 public: 642 void print(); 643 void print_current(); 644 #endif 645 }; 646 647 648 // A Relocation is a flyweight object allocated within a RelocationHolder. 649 // It represents the relocation data of relocation record. 650 // So, the RelocIterator unpacks relocInfos into Relocations. 651 652 class Relocation VALUE_OBJ_CLASS_SPEC { 653 friend class RelocationHolder; 654 friend class RelocIterator; 655 656 private: 657 static void guarantee_size(); 658 659 // When a relocation has been created by a RelocIterator, 660 // this field is non-null. It allows the relocation to know 661 // its context, such as the address to which it applies. 662 RelocIterator* _binding; 663 664 protected: 665 RelocIterator* binding() const { 666 assert(_binding != NULL, "must be bound"); 667 return _binding; 668 } 669 void set_binding(RelocIterator* b) { 670 assert(_binding == NULL, "must be unbound"); 671 _binding = b; 672 assert(_binding != NULL, "must now be bound"); 673 } 674 675 Relocation() { 676 _binding = NULL; 677 } 678 679 static RelocationHolder newHolder() { 680 return RelocationHolder(); 681 } 682 683 public: 684 void* operator new(size_t size, const RelocationHolder& holder) throw() { 685 if (size > sizeof(holder._relocbuf)) guarantee_size(); 686 assert((void* const *)holder.reloc() == &holder._relocbuf[0], "ptrs must agree"); 687 return holder.reloc(); 688 } 689 690 // make a generic relocation for a given type (if possible) 691 static RelocationHolder spec_simple(relocInfo::relocType rtype); 692 693 // here is the type-specific hook which writes relocation data: 694 virtual void pack_data_to(CodeSection* dest) { } 695 696 // here is the type-specific hook which reads (unpacks) relocation data: 697 virtual void unpack_data() { 698 assert(datalen()==0 || type()==relocInfo::none, "no data here"); 699 } 700 701 static bool is_reloc_index(intptr_t index) { 702 return 0 < index && index < os::vm_page_size(); 703 } 704 705 protected: 706 // Helper functions for pack_data_to() and unpack_data(). 707 708 // Most of the compression logic is confined here. 709 // (The "immediate data" mechanism of relocInfo works independently 710 // of this stuff, and acts to further compress most 1-word data prefixes.) 711 712 // A variable-width int is encoded as a short if it will fit in 16 bits. 713 // The decoder looks at datalen to decide whether to unpack short or jint. 714 // Most relocation records are quite simple, containing at most two ints. 715 716 static bool is_short(jint x) { return x == (short)x; } 717 static short* add_short(short* p, int x) { *p++ = x; return p; } 718 static short* add_jint (short* p, jint x) { 719 *p++ = relocInfo::data0_from_int(x); *p++ = relocInfo::data1_from_int(x); 720 return p; 721 } 722 static short* add_var_int(short* p, jint x) { // add a variable-width int 723 if (is_short(x)) p = add_short(p, x); 724 else p = add_jint (p, x); 725 return p; 726 } 727 728 static short* pack_1_int_to(short* p, jint x0) { 729 // Format is one of: [] [x] [Xx] 730 if (x0 != 0) p = add_var_int(p, x0); 731 return p; 732 } 733 int unpack_1_int() { 734 assert(datalen() <= 2, "too much data"); 735 return relocInfo::jint_data_at(0, data(), datalen()); 736 } 737 738 // With two ints, the short form is used only if both ints are short. 739 short* pack_2_ints_to(short* p, jint x0, jint x1) { 740 // Format is one of: [] [x y?] [Xx Y?y] 741 if (x0 == 0 && x1 == 0) { 742 // no halfwords needed to store zeroes 743 } else if (is_short(x0) && is_short(x1)) { 744 // 1-2 halfwords needed to store shorts 745 p = add_short(p, x0); if (x1!=0) p = add_short(p, x1); 746 } else { 747 // 3-4 halfwords needed to store jints 748 p = add_jint(p, x0); p = add_var_int(p, x1); 749 } 750 return p; 751 } 752 void unpack_2_ints(jint& x0, jint& x1) { 753 int dlen = datalen(); 754 short* dp = data(); 755 if (dlen <= 2) { 756 x0 = relocInfo::short_data_at(0, dp, dlen); 757 x1 = relocInfo::short_data_at(1, dp, dlen); 758 } else { 759 assert(dlen <= 4, "too much data"); 760 x0 = relocInfo::jint_data_at(0, dp, dlen); 761 x1 = relocInfo::jint_data_at(2, dp, dlen); 762 } 763 } 764 765 protected: 766 // platform-dependent utilities for decoding and patching instructions 767 void pd_set_data_value (address x, intptr_t off, bool verify_only = false); // a set or mem-ref 768 void pd_verify_data_value (address x, intptr_t off) { pd_set_data_value(x, off, true); } 769 address pd_call_destination (address orig_addr = NULL); 770 void pd_set_call_destination (address x); 771 772 // this extracts the address of an address in the code stream instead of the reloc data 773 address* pd_address_in_code (); 774 775 // this extracts an address from the code stream instead of the reloc data 776 address pd_get_address_from_code (); 777 778 // these convert from byte offsets, to scaled offsets, to addresses 779 static jint scaled_offset(address x, address base) { 780 int byte_offset = x - base; 781 int offset = -byte_offset / relocInfo::addr_unit(); 782 assert(address_from_scaled_offset(offset, base) == x, "just checkin'"); 783 return offset; 784 } 785 static jint scaled_offset_null_special(address x, address base) { 786 // Some relocations treat offset=0 as meaning NULL. 787 // Handle this extra convention carefully. 788 if (x == NULL) return 0; 789 assert(x != base, "offset must not be zero"); 790 return scaled_offset(x, base); 791 } 792 static address address_from_scaled_offset(jint offset, address base) { 793 int byte_offset = -( offset * relocInfo::addr_unit() ); 794 return base + byte_offset; 795 } 796 797 // these convert between indexes and addresses in the runtime system 798 static int32_t runtime_address_to_index(address runtime_address); 799 static address index_to_runtime_address(int32_t index); 800 801 // helpers for mapping between old and new addresses after a move or resize 802 address old_addr_for(address newa, const CodeBuffer* src, CodeBuffer* dest); 803 address new_addr_for(address olda, const CodeBuffer* src, CodeBuffer* dest); 804 void normalize_address(address& addr, const CodeSection* dest, bool allow_other_sections = false); 805 806 public: 807 // accessors which only make sense for a bound Relocation 808 address addr() const { return binding()->addr(); } 809 nmethod* code() const { return binding()->code(); } 810 bool addr_in_const() const { return binding()->addr_in_const(); } 811 protected: 812 short* data() const { return binding()->data(); } 813 int datalen() const { return binding()->datalen(); } 814 int format() const { return binding()->format(); } 815 816 public: 817 virtual relocInfo::relocType type() { return relocInfo::none; } 818 819 // is it a call instruction? 820 virtual bool is_call() { return false; } 821 822 // is it a data movement instruction? 823 virtual bool is_data() { return false; } 824 825 // some relocations can compute their own values 826 virtual address value(); 827 828 // all relocations are able to reassert their values 829 virtual void set_value(address x); 830 831 virtual void clear_inline_cache() { } 832 833 // This method assumes that all virtual/static (inline) caches are cleared (since for static_call_type and 834 // ic_call_type is not always posisition dependent (depending on the state of the cache)). However, this is 835 // probably a reasonable assumption, since empty caches simplifies code reloacation. 836 virtual void fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest) { } 837 838 void print(); 839 }; 840 841 842 // certain inlines must be deferred until class Relocation is defined: 843 844 inline RelocationHolder::RelocationHolder() { 845 // initialize the vtbl, just to keep things type-safe 846 new(*this) Relocation(); 847 } 848 849 850 inline RelocationHolder::RelocationHolder(Relocation* r) { 851 // wordwise copy from r (ok if it copies garbage after r) 852 for (int i = 0; i < _relocbuf_size; i++) { 853 _relocbuf[i] = ((void**)r)[i]; 854 } 855 } 856 857 858 relocInfo::relocType RelocationHolder::type() const { 859 return reloc()->type(); 860 } 861 862 // A DataRelocation always points at a memory or load-constant instruction.. 863 // It is absolute on most machines, and the constant is split on RISCs. 864 // The specific subtypes are oop, external_word, and internal_word. 865 // By convention, the "value" does not include a separately reckoned "offset". 866 class DataRelocation : public Relocation { 867 public: 868 bool is_data() { return true; } 869 870 // both target and offset must be computed somehow from relocation data 871 virtual int offset() { return 0; } 872 address value() = 0; 873 void set_value(address x) { set_value(x, offset()); } 874 void set_value(address x, intptr_t o) { 875 if (addr_in_const()) 876 *(address*)addr() = x; 877 else 878 pd_set_data_value(x, o); 879 } 880 void verify_value(address x) { 881 if (addr_in_const()) 882 assert(*(address*)addr() == x, "must agree"); 883 else 884 pd_verify_data_value(x, offset()); 885 } 886 887 // The "o" (displacement) argument is relevant only to split relocations 888 // on RISC machines. In some CPUs (SPARC), the set-hi and set-lo ins'ns 889 // can encode more than 32 bits between them. This allows compilers to 890 // share set-hi instructions between addresses that differ by a small 891 // offset (e.g., different static variables in the same class). 892 // On such machines, the "x" argument to set_value on all set-lo 893 // instructions must be the same as the "x" argument for the 894 // corresponding set-hi instructions. The "o" arguments for the 895 // set-hi instructions are ignored, and must not affect the high-half 896 // immediate constant. The "o" arguments for the set-lo instructions are 897 // added into the low-half immediate constant, and must not overflow it. 898 }; 899 900 // A CallRelocation always points at a call instruction. 901 // It is PC-relative on most machines. 902 class CallRelocation : public Relocation { 903 public: 904 bool is_call() { return true; } 905 906 address destination() { return pd_call_destination(); } 907 void set_destination(address x); // pd_set_call_destination 908 909 void fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest); 910 address value() { return destination(); } 911 void set_value(address x) { set_destination(x); } 912 }; 913 914 class oop_Relocation : public DataRelocation { 915 relocInfo::relocType type() { return relocInfo::oop_type; } 916 917 public: 918 // encode in one of these formats: [] [n] [n l] [Nn l] [Nn Ll] 919 // an oop in the CodeBlob's oop pool 920 static RelocationHolder spec(int oop_index, int offset = 0) { 921 assert(oop_index > 0, "must be a pool-resident oop"); 922 RelocationHolder rh = newHolder(); 923 new(rh) oop_Relocation(oop_index, offset); 924 return rh; 925 } 926 // an oop in the instruction stream 927 static RelocationHolder spec_for_immediate() { 928 const int oop_index = 0; 929 const int offset = 0; // if you want an offset, use the oop pool 930 RelocationHolder rh = newHolder(); 931 new(rh) oop_Relocation(oop_index, offset); 932 return rh; 933 } 934 935 private: 936 jint _oop_index; // if > 0, index into CodeBlob::oop_at 937 jint _offset; // byte offset to apply to the oop itself 938 939 oop_Relocation(int oop_index, int offset) { 940 _oop_index = oop_index; _offset = offset; 941 } 942 943 friend class RelocIterator; 944 oop_Relocation() { } 945 946 public: 947 int oop_index() { return _oop_index; } 948 int offset() { return _offset; } 949 950 // data is packed in "2_ints" format: [i o] or [Ii Oo] 951 void pack_data_to(CodeSection* dest); 952 void unpack_data(); 953 954 void fix_oop_relocation(); // reasserts oop value 955 956 void verify_oop_relocation(); 957 958 address value() { return (address) *oop_addr(); } 959 960 bool oop_is_immediate() { return oop_index() == 0; } 961 962 oop* oop_addr(); // addr or &pool[jint_data] 963 oop oop_value(); // *oop_addr 964 // Note: oop_value transparently converts Universe::non_oop_word to NULL. 965 }; 966 967 968 // copy of oop_Relocation for now but may delete stuff in both/either 969 class metadata_Relocation : public DataRelocation { 970 relocInfo::relocType type() { return relocInfo::metadata_type; } 971 972 public: 973 // encode in one of these formats: [] [n] [n l] [Nn l] [Nn Ll] 974 // an metadata in the CodeBlob's metadata pool 975 static RelocationHolder spec(int metadata_index, int offset = 0) { 976 assert(metadata_index > 0, "must be a pool-resident metadata"); 977 RelocationHolder rh = newHolder(); 978 new(rh) metadata_Relocation(metadata_index, offset); 979 return rh; 980 } 981 // an metadata in the instruction stream 982 static RelocationHolder spec_for_immediate() { 983 const int metadata_index = 0; 984 const int offset = 0; // if you want an offset, use the metadata pool 985 RelocationHolder rh = newHolder(); 986 new(rh) metadata_Relocation(metadata_index, offset); 987 return rh; 988 } 989 990 private: 991 jint _metadata_index; // if > 0, index into nmethod::metadata_at 992 jint _offset; // byte offset to apply to the metadata itself 993 994 metadata_Relocation(int metadata_index, int offset) { 995 _metadata_index = metadata_index; _offset = offset; 996 } 997 998 friend class RelocIterator; 999 metadata_Relocation() { } 1000 1001 // Fixes a Metadata pointer in the code. Most platforms embeds the 1002 // Metadata pointer in the code at compile time so this is empty 1003 // for them. 1004 void pd_fix_value(address x); 1005 1006 public: 1007 int metadata_index() { return _metadata_index; } 1008 int offset() { return _offset; } 1009 1010 // data is packed in "2_ints" format: [i o] or [Ii Oo] 1011 void pack_data_to(CodeSection* dest); 1012 void unpack_data(); 1013 1014 void fix_metadata_relocation(); // reasserts metadata value 1015 1016 void verify_metadata_relocation(); 1017 1018 address value() { return (address) *metadata_addr(); } 1019 1020 bool metadata_is_immediate() { return metadata_index() == 0; } 1021 1022 Metadata** metadata_addr(); // addr or &pool[jint_data] 1023 Metadata* metadata_value(); // *metadata_addr 1024 // Note: metadata_value transparently converts Universe::non_metadata_word to NULL. 1025 }; 1026 1027 1028 class virtual_call_Relocation : public CallRelocation { 1029 relocInfo::relocType type() { return relocInfo::virtual_call_type; } 1030 1031 public: 1032 // "cached_value" points to the first associated set-oop. 1033 // The oop_limit helps find the last associated set-oop. 1034 // (See comments at the top of this file.) 1035 static RelocationHolder spec(address cached_value) { 1036 RelocationHolder rh = newHolder(); 1037 new(rh) virtual_call_Relocation(cached_value); 1038 return rh; 1039 } 1040 1041 virtual_call_Relocation(address cached_value) { 1042 _cached_value = cached_value; 1043 assert(cached_value != NULL, "first oop address must be specified"); 1044 } 1045 1046 private: 1047 address _cached_value; // location of set-value instruction 1048 1049 friend class RelocIterator; 1050 virtual_call_Relocation() { } 1051 1052 1053 public: 1054 address cached_value(); 1055 1056 // data is packed as scaled offsets in "2_ints" format: [f l] or [Ff Ll] 1057 // oop_limit is set to 0 if the limit falls somewhere within the call. 1058 // When unpacking, a zero oop_limit is taken to refer to the end of the call. 1059 // (This has the effect of bringing in the call's delay slot on SPARC.) 1060 void pack_data_to(CodeSection* dest); 1061 void unpack_data(); 1062 1063 void clear_inline_cache(); 1064 }; 1065 1066 1067 class opt_virtual_call_Relocation : public CallRelocation { 1068 relocInfo::relocType type() { return relocInfo::opt_virtual_call_type; } 1069 1070 public: 1071 static RelocationHolder spec() { 1072 RelocationHolder rh = newHolder(); 1073 new(rh) opt_virtual_call_Relocation(); 1074 return rh; 1075 } 1076 1077 private: 1078 friend class RelocIterator; 1079 opt_virtual_call_Relocation() { } 1080 1081 public: 1082 void clear_inline_cache(); 1083 1084 // find the matching static_stub 1085 address static_stub(); 1086 }; 1087 1088 1089 class static_call_Relocation : public CallRelocation { 1090 relocInfo::relocType type() { return relocInfo::static_call_type; } 1091 1092 public: 1093 static RelocationHolder spec() { 1094 RelocationHolder rh = newHolder(); 1095 new(rh) static_call_Relocation(); 1096 return rh; 1097 } 1098 1099 private: 1100 friend class RelocIterator; 1101 static_call_Relocation() { } 1102 1103 public: 1104 void clear_inline_cache(); 1105 1106 // find the matching static_stub 1107 address static_stub(); 1108 }; 1109 1110 class static_stub_Relocation : public Relocation { 1111 relocInfo::relocType type() { return relocInfo::static_stub_type; } 1112 1113 public: 1114 static RelocationHolder spec(address static_call) { 1115 RelocationHolder rh = newHolder(); 1116 new(rh) static_stub_Relocation(static_call); 1117 return rh; 1118 } 1119 1120 private: 1121 address _static_call; // location of corresponding static_call 1122 1123 static_stub_Relocation(address static_call) { 1124 _static_call = static_call; 1125 } 1126 1127 friend class RelocIterator; 1128 static_stub_Relocation() { } 1129 1130 public: 1131 void clear_inline_cache(); 1132 1133 address static_call() { return _static_call; } 1134 1135 // data is packed as a scaled offset in "1_int" format: [c] or [Cc] 1136 void pack_data_to(CodeSection* dest); 1137 void unpack_data(); 1138 }; 1139 1140 class runtime_call_Relocation : public CallRelocation { 1141 relocInfo::relocType type() { return relocInfo::runtime_call_type; } 1142 1143 public: 1144 static RelocationHolder spec() { 1145 RelocationHolder rh = newHolder(); 1146 new(rh) runtime_call_Relocation(); 1147 return rh; 1148 } 1149 1150 private: 1151 friend class RelocIterator; 1152 runtime_call_Relocation() { } 1153 1154 public: 1155 }; 1156 1157 // Trampoline Relocations. 1158 // A trampoline allows to encode a small branch in the code, even if there 1159 // is the chance that this branch can not reach all possible code locations. 1160 // If the relocation finds that a branch is too far for the instruction 1161 // in the code, it can patch it to jump to the trampoline where is 1162 // sufficient space for a far branch. Needed on PPC. 1163 class trampoline_stub_Relocation : public Relocation { 1164 relocInfo::relocType type() { return relocInfo::trampoline_stub_type; } 1165 1166 public: 1167 static RelocationHolder spec(address static_call) { 1168 RelocationHolder rh = newHolder(); 1169 return (new (rh) trampoline_stub_Relocation(static_call)); 1170 } 1171 1172 private: 1173 address _owner; // Address of the NativeCall that owns the trampoline. 1174 1175 trampoline_stub_Relocation(address owner) { 1176 _owner = owner; 1177 } 1178 1179 friend class RelocIterator; 1180 trampoline_stub_Relocation() { } 1181 1182 public: 1183 1184 // Return the address of the NativeCall that owns the trampoline. 1185 address owner() { return _owner; } 1186 1187 void pack_data_to(CodeSection * dest); 1188 void unpack_data(); 1189 1190 // Find the trampoline stub for a call. 1191 static address get_trampoline_for(address call, nmethod* code); 1192 }; 1193 1194 class external_word_Relocation : public DataRelocation { 1195 relocInfo::relocType type() { return relocInfo::external_word_type; } 1196 1197 public: 1198 static RelocationHolder spec(address target) { 1199 assert(target != NULL, "must not be null"); 1200 RelocationHolder rh = newHolder(); 1201 new(rh) external_word_Relocation(target); 1202 return rh; 1203 } 1204 1205 // Use this one where all 32/64 bits of the target live in the code stream. 1206 // The target must be an intptr_t, and must be absolute (not relative). 1207 static RelocationHolder spec_for_immediate() { 1208 RelocationHolder rh = newHolder(); 1209 new(rh) external_word_Relocation(NULL); 1210 return rh; 1211 } 1212 1213 // Some address looking values aren't safe to treat as relocations 1214 // and should just be treated as constants. 1215 static bool can_be_relocated(address target) { 1216 return target != NULL && !is_reloc_index((intptr_t)target); 1217 } 1218 1219 private: 1220 address _target; // address in runtime 1221 1222 external_word_Relocation(address target) { 1223 _target = target; 1224 } 1225 1226 friend class RelocIterator; 1227 external_word_Relocation() { } 1228 1229 public: 1230 // data is packed as a well-known address in "1_int" format: [a] or [Aa] 1231 // The function runtime_address_to_index is used to turn full addresses 1232 // to short indexes, if they are pre-registered by the stub mechanism. 1233 // If the "a" value is 0 (i.e., _target is NULL), the address is stored 1234 // in the code stream. See external_word_Relocation::target(). 1235 void pack_data_to(CodeSection* dest); 1236 void unpack_data(); 1237 1238 void fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest); 1239 address target(); // if _target==NULL, fetch addr from code stream 1240 address value() { return target(); } 1241 }; 1242 1243 class internal_word_Relocation : public DataRelocation { 1244 relocInfo::relocType type() { return relocInfo::internal_word_type; } 1245 1246 public: 1247 static RelocationHolder spec(address target) { 1248 assert(target != NULL, "must not be null"); 1249 RelocationHolder rh = newHolder(); 1250 new(rh) internal_word_Relocation(target); 1251 return rh; 1252 } 1253 1254 // use this one where all the bits of the target can fit in the code stream: 1255 static RelocationHolder spec_for_immediate() { 1256 RelocationHolder rh = newHolder(); 1257 new(rh) internal_word_Relocation(NULL); 1258 return rh; 1259 } 1260 1261 internal_word_Relocation(address target) { 1262 _target = target; 1263 _section = -1; // self-relative 1264 } 1265 1266 protected: 1267 address _target; // address in CodeBlob 1268 int _section; // section providing base address, if any 1269 1270 friend class RelocIterator; 1271 internal_word_Relocation() { } 1272 1273 // bit-width of LSB field in packed offset, if section >= 0 1274 enum { section_width = 2 }; // must equal CodeBuffer::sect_bits 1275 1276 public: 1277 // data is packed as a scaled offset in "1_int" format: [o] or [Oo] 1278 // If the "o" value is 0 (i.e., _target is NULL), the offset is stored 1279 // in the code stream. See internal_word_Relocation::target(). 1280 // If _section is not -1, it is appended to the low bits of the offset. 1281 void pack_data_to(CodeSection* dest); 1282 void unpack_data(); 1283 1284 void fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest); 1285 address target(); // if _target==NULL, fetch addr from code stream 1286 int section() { return _section; } 1287 address value() { return target(); } 1288 }; 1289 1290 class section_word_Relocation : public internal_word_Relocation { 1291 relocInfo::relocType type() { return relocInfo::section_word_type; } 1292 1293 public: 1294 static RelocationHolder spec(address target, int section) { 1295 RelocationHolder rh = newHolder(); 1296 new(rh) section_word_Relocation(target, section); 1297 return rh; 1298 } 1299 1300 section_word_Relocation(address target, int section) { 1301 assert(target != NULL, "must not be null"); 1302 assert(section >= 0, "must be a valid section"); 1303 _target = target; 1304 _section = section; 1305 } 1306 1307 //void pack_data_to -- inherited 1308 void unpack_data(); 1309 1310 private: 1311 friend class RelocIterator; 1312 section_word_Relocation() { } 1313 }; 1314 1315 1316 class poll_Relocation : public Relocation { 1317 bool is_data() { return true; } 1318 relocInfo::relocType type() { return relocInfo::poll_type; } 1319 void fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest); 1320 }; 1321 1322 class poll_return_Relocation : public Relocation { 1323 bool is_data() { return true; } 1324 relocInfo::relocType type() { return relocInfo::poll_return_type; } 1325 void fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest); 1326 }; 1327 1328 // We know all the xxx_Relocation classes, so now we can define these: 1329 #define EACH_CASE(name) \ 1330 inline name##_Relocation* RelocIterator::name##_reloc() { \ 1331 assert(type() == relocInfo::name##_type, "type must agree"); \ 1332 /* The purpose of the placed "new" is to re-use the same */ \ 1333 /* stack storage for each new iteration. */ \ 1334 name##_Relocation* r = new(_rh) name##_Relocation(); \ 1335 r->set_binding(this); \ 1336 r->name##_Relocation::unpack_data(); \ 1337 return r; \ 1338 } 1339 APPLY_TO_RELOCATIONS(EACH_CASE); 1340 #undef EACH_CASE 1341 1342 inline RelocIterator::RelocIterator(nmethod* nm, address begin, address limit) { 1343 initialize(nm, begin, limit); 1344 } 1345 1346 #endif // SHARE_VM_CODE_RELOCINFO_HPP