1 /* 2 * Copyright (c) 1997, 2010, 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 class CodeComments; 26 class AbstractAssembler; 27 class MacroAssembler; 28 class PhaseCFG; 29 class Compile; 30 class BufferBlob; 31 class CodeBuffer; 32 33 class CodeOffsets: public StackObj { 34 public: 35 enum Entries { Entry, 36 Verified_Entry, 37 Frame_Complete, // Offset in the code where the frame setup is (for forte stackwalks) is complete 38 OSR_Entry, 39 Dtrace_trap = OSR_Entry, // dtrace probes can never have an OSR entry so reuse it 40 Exceptions, // Offset where exception handler lives 41 Deopt, // Offset where deopt handler lives 42 DeoptMH, // Offset where MethodHandle deopt handler lives 43 UnwindHandler, // Offset to default unwind handler 44 max_Entries }; 45 46 // special value to note codeBlobs where profile (forte) stack walking is 47 // always dangerous and suspect. 48 49 enum { frame_never_safe = -1 }; 50 51 private: 52 int _values[max_Entries]; 53 54 public: 55 CodeOffsets() { 56 _values[Entry ] = 0; 57 _values[Verified_Entry] = 0; 58 _values[Frame_Complete] = frame_never_safe; 59 _values[OSR_Entry ] = 0; 60 _values[Exceptions ] = -1; 61 _values[Deopt ] = -1; 62 _values[DeoptMH ] = -1; 63 _values[UnwindHandler ] = -1; 64 } 65 66 int value(Entries e) { return _values[e]; } 67 void set_value(Entries e, int val) { _values[e] = val; } 68 }; 69 70 // This class represents a stream of code and associated relocations. 71 // There are a few in each CodeBuffer. 72 // They are filled concurrently, and concatenated at the end. 73 class CodeSection VALUE_OBJ_CLASS_SPEC { 74 friend class CodeBuffer; 75 public: 76 typedef int csize_t; // code size type; would be size_t except for history 77 78 private: 79 address _start; // first byte of contents (instructions) 80 address _mark; // user mark, usually an instruction beginning 81 address _end; // current end address 82 address _limit; // last possible (allocated) end address 83 relocInfo* _locs_start; // first byte of relocation information 84 relocInfo* _locs_end; // first byte after relocation information 85 relocInfo* _locs_limit; // first byte after relocation information buf 86 address _locs_point; // last relocated position (grows upward) 87 bool _locs_own; // did I allocate the locs myself? 88 bool _frozen; // no more expansion of this section 89 char _index; // my section number (SECT_INST, etc.) 90 CodeBuffer* _outer; // enclosing CodeBuffer 91 92 // (Note: _locs_point used to be called _last_reloc_offset.) 93 94 CodeSection() { 95 _start = NULL; 96 _mark = NULL; 97 _end = NULL; 98 _limit = NULL; 99 _locs_start = NULL; 100 _locs_end = NULL; 101 _locs_limit = NULL; 102 _locs_point = NULL; 103 _locs_own = false; 104 _frozen = false; 105 debug_only(_index = (char)-1); 106 debug_only(_outer = (CodeBuffer*)badAddress); 107 } 108 109 void initialize_outer(CodeBuffer* outer, int index) { 110 _outer = outer; 111 _index = index; 112 } 113 114 void initialize(address start, csize_t size = 0) { 115 assert(_start == NULL, "only one init step, please"); 116 _start = start; 117 _mark = NULL; 118 _end = start; 119 120 _limit = start + size; 121 _locs_point = start; 122 } 123 124 void initialize_locs(int locs_capacity); 125 void expand_locs(int new_capacity); 126 void initialize_locs_from(const CodeSection* source_cs); 127 128 // helper for CodeBuffer::expand() 129 void take_over_code_from(CodeSection* cs) { 130 _start = cs->_start; 131 _mark = cs->_mark; 132 _end = cs->_end; 133 _limit = cs->_limit; 134 _locs_point = cs->_locs_point; 135 } 136 137 public: 138 address start() const { return _start; } 139 address mark() const { return _mark; } 140 address end() const { return _end; } 141 address limit() const { return _limit; } 142 csize_t size() const { return (csize_t)(_end - _start); } 143 csize_t mark_off() const { assert(_mark != NULL, "not an offset"); 144 return (csize_t)(_mark - _start); } 145 csize_t capacity() const { return (csize_t)(_limit - _start); } 146 csize_t remaining() const { return (csize_t)(_limit - _end); } 147 148 relocInfo* locs_start() const { return _locs_start; } 149 relocInfo* locs_end() const { return _locs_end; } 150 int locs_count() const { return (int)(_locs_end - _locs_start); } 151 relocInfo* locs_limit() const { return _locs_limit; } 152 address locs_point() const { return _locs_point; } 153 csize_t locs_point_off() const{ return (csize_t)(_locs_point - _start); } 154 csize_t locs_capacity() const { return (csize_t)(_locs_limit - _locs_start); } 155 csize_t locs_remaining()const { return (csize_t)(_locs_limit - _locs_end); } 156 157 int index() const { return _index; } 158 bool is_allocated() const { return _start != NULL; } 159 bool is_empty() const { return _start == _end; } 160 bool is_frozen() const { return _frozen; } 161 bool has_locs() const { return _locs_end != NULL; } 162 163 CodeBuffer* outer() const { return _outer; } 164 165 // is a given address in this section? (2nd version is end-inclusive) 166 bool contains(address pc) const { return pc >= _start && pc < _end; } 167 bool contains2(address pc) const { return pc >= _start && pc <= _end; } 168 bool allocates(address pc) const { return pc >= _start && pc < _limit; } 169 bool allocates2(address pc) const { return pc >= _start && pc <= _limit; } 170 171 void set_end(address pc) { assert(allocates2(pc), err_msg("not in CodeBuffer memory: " PTR_FORMAT " <= " PTR_FORMAT " <= " PTR_FORMAT, _start, pc, _limit)); _end = pc; } 172 void set_mark(address pc) { assert(contains2(pc), "not in codeBuffer"); 173 _mark = pc; } 174 void set_mark_off(int offset) { assert(contains2(offset+_start),"not in codeBuffer"); 175 _mark = offset + _start; } 176 void set_mark() { _mark = _end; } 177 void clear_mark() { _mark = NULL; } 178 179 void set_locs_end(relocInfo* p) { 180 assert(p <= locs_limit(), "locs data fits in allocated buffer"); 181 _locs_end = p; 182 } 183 void set_locs_point(address pc) { 184 assert(pc >= locs_point(), "relocation addr may not decrease"); 185 assert(allocates2(pc), "relocation addr must be in this section"); 186 _locs_point = pc; 187 } 188 189 // Code emission 190 void emit_int8 (int8_t x) { *((int8_t*) end()) = x; set_end(end() + 1); } 191 void emit_int16(int16_t x) { *((int16_t*) end()) = x; set_end(end() + 2); } 192 void emit_int32(int32_t x) { *((int32_t*) end()) = x; set_end(end() + 4); } 193 void emit_int64(int64_t x) { *((int64_t*) end()) = x; set_end(end() + 8); } 194 195 // Share a scratch buffer for relocinfo. (Hacky; saves a resource allocation.) 196 void initialize_shared_locs(relocInfo* buf, int length); 197 198 // Manage labels and their addresses. 199 address target(Label& L, address branch_pc); 200 201 // Emit a relocation. 202 void relocate(address at, RelocationHolder const& rspec, int format = 0); 203 void relocate(address at, relocInfo::relocType rtype, int format = 0) { 204 if (rtype != relocInfo::none) 205 relocate(at, Relocation::spec_simple(rtype), format); 206 } 207 208 // alignment requirement for starting offset 209 // Requirements are that the instruction area and the 210 // stubs area must start on CodeEntryAlignment, and 211 // the ctable on sizeof(jdouble) 212 int alignment() const { return MAX2((int)sizeof(jdouble), (int)CodeEntryAlignment); } 213 214 // Slop between sections, used only when allocating temporary BufferBlob buffers. 215 static csize_t end_slop() { return MAX2((int)sizeof(jdouble), (int)CodeEntryAlignment); } 216 217 csize_t align_at_start(csize_t off) const { return (csize_t) align_size_up(off, alignment()); } 218 219 // Mark a section frozen. Assign its remaining space to 220 // the following section. It will never expand after this point. 221 inline void freeze(); // { _outer->freeze_section(this); } 222 223 // Ensure there's enough space left in the current section. 224 // Return true if there was an expansion. 225 bool maybe_expand_to_ensure_remaining(csize_t amount); 226 227 #ifndef PRODUCT 228 void decode(); 229 void dump(); 230 void print(const char* name); 231 #endif //PRODUCT 232 }; 233 234 class CodeComment; 235 class CodeComments VALUE_OBJ_CLASS_SPEC { 236 private: 237 #ifndef PRODUCT 238 CodeComment* _comments; 239 #endif 240 241 public: 242 CodeComments() { 243 #ifndef PRODUCT 244 _comments = NULL; 245 #endif 246 } 247 248 void add_comment(intptr_t offset, const char * comment) PRODUCT_RETURN; 249 void print_block_comment(outputStream* stream, intptr_t offset) PRODUCT_RETURN; 250 void assign(CodeComments& other) PRODUCT_RETURN; 251 void free() PRODUCT_RETURN; 252 }; 253 254 255 // A CodeBuffer describes a memory space into which assembly 256 // code is generated. This memory space usually occupies the 257 // interior of a single BufferBlob, but in some cases it may be 258 // an arbitrary span of memory, even outside the code cache. 259 // 260 // A code buffer comes in two variants: 261 // 262 // (1) A CodeBuffer referring to an already allocated piece of memory: 263 // This is used to direct 'static' code generation (e.g. for interpreter 264 // or stubroutine generation, etc.). This code comes with NO relocation 265 // information. 266 // 267 // (2) A CodeBuffer referring to a piece of memory allocated when the 268 // CodeBuffer is allocated. This is used for nmethod generation. 269 // 270 // The memory can be divided up into several parts called sections. 271 // Each section independently accumulates code (or data) an relocations. 272 // Sections can grow (at the expense of a reallocation of the BufferBlob 273 // and recopying of all active sections). When the buffered code is finally 274 // written to an nmethod (or other CodeBlob), the contents (code, data, 275 // and relocations) of the sections are padded to an alignment and concatenated. 276 // Instructions and data in one section can contain relocatable references to 277 // addresses in a sibling section. 278 279 class CodeBuffer: public StackObj { 280 friend class CodeSection; 281 282 private: 283 // CodeBuffers must be allocated on the stack except for a single 284 // special case during expansion which is handled internally. This 285 // is done to guarantee proper cleanup of resources. 286 void* operator new(size_t size) { return ResourceObj::operator new(size); } 287 void operator delete(void* p) { ShouldNotCallThis(); } 288 289 public: 290 typedef int csize_t; // code size type; would be size_t except for history 291 enum { 292 // Here is the list of all possible sections. The order reflects 293 // the final layout. 294 SECT_FIRST = 0, 295 SECT_CONSTS = SECT_FIRST, // Non-instruction data: Floats, jump tables, etc. 296 SECT_INSTS, // Executable instructions. 297 SECT_STUBS, // Outbound trampolines for supporting call sites. 298 SECT_LIMIT, SECT_NONE = -1 299 }; 300 301 private: 302 enum { 303 sect_bits = 2, // assert (SECT_LIMIT <= (1<<sect_bits)) 304 sect_mask = (1<<sect_bits)-1 305 }; 306 307 const char* _name; 308 309 CodeSection _consts; // constants, jump tables 310 CodeSection _insts; // instructions (the main section) 311 CodeSection _stubs; // stubs (call site support), deopt, exception handling 312 313 CodeBuffer* _before_expand; // dead buffer, from before the last expansion 314 315 BufferBlob* _blob; // optional buffer in CodeCache for generated code 316 address _total_start; // first address of combined memory buffer 317 csize_t _total_size; // size in bytes of combined memory buffer 318 319 OopRecorder* _oop_recorder; 320 CodeComments _comments; 321 OopRecorder _default_oop_recorder; // override with initialize_oop_recorder 322 Arena* _overflow_arena; 323 324 address _decode_begin; // start address for decode 325 address decode_begin(); 326 327 void initialize_misc(const char * name) { 328 // all pointers other than code_start/end and those inside the sections 329 assert(name != NULL, "must have a name"); 330 _name = name; 331 _before_expand = NULL; 332 _blob = NULL; 333 _oop_recorder = NULL; 334 _decode_begin = NULL; 335 _overflow_arena = NULL; 336 } 337 338 void initialize(address code_start, csize_t code_size) { 339 _consts.initialize_outer(this, SECT_CONSTS); 340 _insts.initialize_outer(this, SECT_INSTS); 341 _stubs.initialize_outer(this, SECT_STUBS); 342 _total_start = code_start; 343 _total_size = code_size; 344 // Initialize the main section: 345 _insts.initialize(code_start, code_size); 346 assert(!_stubs.is_allocated(), "no garbage here"); 347 assert(!_consts.is_allocated(), "no garbage here"); 348 _oop_recorder = &_default_oop_recorder; 349 } 350 351 void initialize_section_size(CodeSection* cs, csize_t size); 352 353 void freeze_section(CodeSection* cs); 354 355 // helper for CodeBuffer::expand() 356 void take_over_code_from(CodeBuffer* cs); 357 358 #ifdef ASSERT 359 // ensure sections are disjoint, ordered, and contained in the blob 360 bool verify_section_allocation(); 361 #endif 362 363 // copies combined relocations to the blob, returns bytes copied 364 // (if target is null, it is a dry run only, just for sizing) 365 csize_t copy_relocations_to(CodeBlob* blob) const; 366 367 // copies combined code to the blob (assumes relocs are already in there) 368 void copy_code_to(CodeBlob* blob); 369 370 // moves code sections to new buffer (assumes relocs are already in there) 371 void relocate_code_to(CodeBuffer* cb) const; 372 373 // set up a model of the final layout of my contents 374 void compute_final_layout(CodeBuffer* dest) const; 375 376 // Expand the given section so at least 'amount' is remaining. 377 // Creates a new, larger BufferBlob, and rewrites the code & relocs. 378 void expand(CodeSection* which_cs, csize_t amount); 379 380 // Helper for expand. 381 csize_t figure_expanded_capacities(CodeSection* which_cs, csize_t amount, csize_t* new_capacity); 382 383 public: 384 // (1) code buffer referring to pre-allocated instruction memory 385 CodeBuffer(address code_start, csize_t code_size) { 386 assert(code_start != NULL, "sanity"); 387 initialize_misc("static buffer"); 388 initialize(code_start, code_size); 389 assert(verify_section_allocation(), "initial use of buffer OK"); 390 } 391 392 // (2) CodeBuffer referring to pre-allocated CodeBlob. 393 CodeBuffer(CodeBlob* blob); 394 395 // (3) code buffer allocating codeBlob memory for code & relocation 396 // info but with lazy initialization. The name must be something 397 // informative. 398 CodeBuffer(const char* name) { 399 initialize_misc(name); 400 } 401 402 403 // (4) code buffer allocating codeBlob memory for code & relocation 404 // info. The name must be something informative and code_size must 405 // include both code and stubs sizes. 406 CodeBuffer(const char* name, csize_t code_size, csize_t locs_size) { 407 initialize_misc(name); 408 initialize(code_size, locs_size); 409 } 410 411 ~CodeBuffer(); 412 413 // Initialize a CodeBuffer constructed using constructor 3. Using 414 // constructor 4 is equivalent to calling constructor 3 and then 415 // calling this method. It's been factored out for convenience of 416 // construction. 417 void initialize(csize_t code_size, csize_t locs_size); 418 419 CodeSection* consts() { return &_consts; } 420 CodeSection* insts() { return &_insts; } 421 CodeSection* stubs() { return &_stubs; } 422 423 // present sections in order; return NULL at end; consts is #0, etc. 424 CodeSection* code_section(int n) { 425 // This makes the slightly questionable but portable assumption 426 // that the various members (_consts, _insts, _stubs, etc.) are 427 // adjacent in the layout of CodeBuffer. 428 CodeSection* cs = &_consts + n; 429 assert(cs->index() == n || !cs->is_allocated(), "sanity"); 430 return cs; 431 } 432 const CodeSection* code_section(int n) const { // yucky const stuff 433 return ((CodeBuffer*)this)->code_section(n); 434 } 435 static const char* code_section_name(int n); 436 int section_index_of(address addr) const; 437 bool contains(address addr) const { 438 // handy for debugging 439 return section_index_of(addr) > SECT_NONE; 440 } 441 442 // A stable mapping between 'locators' (small ints) and addresses. 443 static int locator_pos(int locator) { return locator >> sect_bits; } 444 static int locator_sect(int locator) { return locator & sect_mask; } 445 static int locator(int pos, int sect) { return (pos << sect_bits) | sect; } 446 int locator(address addr) const; 447 address locator_address(int locator) const; 448 449 // Properties 450 const char* name() const { return _name; } 451 CodeBuffer* before_expand() const { return _before_expand; } 452 BufferBlob* blob() const { return _blob; } 453 void set_blob(BufferBlob* blob); 454 void free_blob(); // Free the blob, if we own one. 455 456 // Properties relative to the insts section: 457 address insts_begin() const { return _insts.start(); } 458 address insts_end() const { return _insts.end(); } 459 void set_insts_end(address end) { _insts.set_end(end); } 460 address insts_limit() const { return _insts.limit(); } 461 address insts_mark() const { return _insts.mark(); } 462 void set_insts_mark() { _insts.set_mark(); } 463 void clear_insts_mark() { _insts.clear_mark(); } 464 465 // is there anything in the buffer other than the current section? 466 bool is_pure() const { return insts_size() == total_content_size(); } 467 468 // size in bytes of output so far in the insts sections 469 csize_t insts_size() const { return _insts.size(); } 470 471 // same as insts_size(), except that it asserts there is no non-code here 472 csize_t pure_insts_size() const { assert(is_pure(), "no non-code"); 473 return insts_size(); } 474 // capacity in bytes of the insts sections 475 csize_t insts_capacity() const { return _insts.capacity(); } 476 477 // number of bytes remaining in the insts section 478 csize_t insts_remaining() const { return _insts.remaining(); } 479 480 // is a given address in the insts section? (2nd version is end-inclusive) 481 bool insts_contains(address pc) const { return _insts.contains(pc); } 482 bool insts_contains2(address pc) const { return _insts.contains2(pc); } 483 484 // Allocated size in all sections, when aligned and concatenated 485 // (this is the eventual state of the content in its final 486 // CodeBlob). 487 csize_t total_content_size() const; 488 489 // Combined offset (relative to start of first section) of given 490 // section, as eventually found in the final CodeBlob. 491 csize_t total_offset_of(CodeSection* cs) const; 492 493 // allocated size of all relocation data, including index, rounded up 494 csize_t total_relocation_size() const; 495 496 // allocated size of any and all recorded oops 497 csize_t total_oop_size() const { 498 OopRecorder* recorder = oop_recorder(); 499 return (recorder == NULL)? 0: recorder->oop_size(); 500 } 501 502 // Configuration functions, called immediately after the CB is constructed. 503 // The section sizes are subtracted from the original insts section. 504 // Note: Call them in reverse section order, because each steals from insts. 505 void initialize_consts_size(csize_t size) { initialize_section_size(&_consts, size); } 506 void initialize_stubs_size(csize_t size) { initialize_section_size(&_stubs, size); } 507 // Override default oop recorder. 508 void initialize_oop_recorder(OopRecorder* r); 509 510 OopRecorder* oop_recorder() const { return _oop_recorder; } 511 CodeComments& comments() { return _comments; } 512 513 // Code generation 514 void relocate(address at, RelocationHolder const& rspec, int format = 0) { 515 _insts.relocate(at, rspec, format); 516 } 517 void relocate(address at, relocInfo::relocType rtype, int format = 0) { 518 _insts.relocate(at, rtype, format); 519 } 520 521 // Management of overflow storage for binding of Labels. 522 GrowableArray<int>* create_patch_overflow(); 523 524 // NMethod generation 525 void copy_code_and_locs_to(CodeBlob* blob) { 526 assert(blob != NULL, "sane"); 527 copy_relocations_to(blob); 528 copy_code_to(blob); 529 } 530 void copy_oops_to(nmethod* nm) { 531 if (!oop_recorder()->is_unused()) { 532 oop_recorder()->copy_to(nm); 533 } 534 } 535 536 // Transform an address from the code in this code buffer to a specified code buffer 537 address transform_address(const CodeBuffer &cb, address addr) const; 538 539 void block_comment(intptr_t offset, const char * comment) PRODUCT_RETURN; 540 541 #ifndef PRODUCT 542 public: 543 // Printing / Decoding 544 // decodes from decode_begin() to code_end() and sets decode_begin to end 545 void decode(); 546 void decode_all(); // decodes all the code 547 void skip_decode(); // sets decode_begin to code_end(); 548 void print(); 549 #endif 550 551 552 // The following header contains architecture-specific implementations 553 #include "incls/_codeBuffer_pd.hpp.incl" 554 }; 555 556 557 inline void CodeSection::freeze() { 558 _outer->freeze_section(this); 559 } 560 561 inline bool CodeSection::maybe_expand_to_ensure_remaining(csize_t amount) { 562 if (remaining() < amount) { _outer->expand(this, amount); return true; } 563 return false; 564 }