MCAssembler.h revision c5252da873d547a19069eaf9030fec203f128f66
1//===- MCAssembler.h - Object File Generation -------------------*- C++ -*-===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9 10#ifndef LLVM_MC_MCASSEMBLER_H 11#define LLVM_MC_MCASSEMBLER_H 12 13#include "llvm/MC/MCFixup.h" 14#include "llvm/MC/MCInst.h" 15#include "llvm/ADT/DenseMap.h" 16#include "llvm/ADT/SmallPtrSet.h" 17#include "llvm/ADT/SmallString.h" 18#include "llvm/ADT/ilist.h" 19#include "llvm/ADT/ilist_node.h" 20#include "llvm/Support/Casting.h" 21#include "llvm/Support/DataTypes.h" 22#include <vector> // FIXME: Shouldn't be needed. 23 24namespace llvm { 25class raw_ostream; 26class MCAsmLayout; 27class MCAssembler; 28class MCContext; 29class MCCodeEmitter; 30class MCExpr; 31class MCFragment; 32class MCObjectWriter; 33class MCSection; 34class MCSectionData; 35class MCSymbol; 36class MCSymbolData; 37class MCValue; 38class MCAsmBackend; 39 40class MCFragment : public ilist_node<MCFragment> { 41 friend class MCAsmLayout; 42 43 MCFragment(const MCFragment&) LLVM_DELETED_FUNCTION; 44 void operator=(const MCFragment&) LLVM_DELETED_FUNCTION; 45 46public: 47 enum FragmentType { 48 FT_Align, 49 FT_Data, 50 FT_Fill, 51 FT_Inst, 52 FT_Org, 53 FT_Dwarf, 54 FT_DwarfFrame, 55 FT_LEB 56 }; 57 58private: 59 FragmentType Kind; 60 61 /// Parent - The data for the section this fragment is in. 62 MCSectionData *Parent; 63 64 /// Atom - The atom this fragment is in, as represented by it's defining 65 /// symbol. Atom's are only used by backends which set 66 /// \see MCAsmBackend::hasReliableSymbolDifference(). 67 MCSymbolData *Atom; 68 69 /// @name Assembler Backend Data 70 /// @{ 71 // 72 // FIXME: This could all be kept private to the assembler implementation. 73 74 /// Offset - The offset of this fragment in its section. This is ~0 until 75 /// initialized. 76 uint64_t Offset; 77 78 /// LayoutOrder - The layout order of this fragment. 79 unsigned LayoutOrder; 80 81 /// @} 82 83protected: 84 MCFragment(FragmentType _Kind, MCSectionData *_Parent = 0); 85 86public: 87 // Only for sentinel. 88 MCFragment(); 89 virtual ~MCFragment(); 90 91 FragmentType getKind() const { return Kind; } 92 93 MCSectionData *getParent() const { return Parent; } 94 void setParent(MCSectionData *Value) { Parent = Value; } 95 96 MCSymbolData *getAtom() const { return Atom; } 97 void setAtom(MCSymbolData *Value) { Atom = Value; } 98 99 unsigned getLayoutOrder() const { return LayoutOrder; } 100 void setLayoutOrder(unsigned Value) { LayoutOrder = Value; } 101 102 static bool classof(const MCFragment *O) { return true; } 103 104 void dump(); 105}; 106 107class MCDataFragment : public MCFragment { 108 virtual void anchor(); 109 SmallString<32> Contents; 110 111 /// Fixups - The list of fixups in this fragment. 112 std::vector<MCFixup> Fixups; 113 114public: 115 typedef std::vector<MCFixup>::const_iterator const_fixup_iterator; 116 typedef std::vector<MCFixup>::iterator fixup_iterator; 117 118public: 119 MCDataFragment(MCSectionData *SD = 0) : MCFragment(FT_Data, SD) {} 120 121 /// @name Accessors 122 /// @{ 123 124 SmallString<32> &getContents() { return Contents; } 125 const SmallString<32> &getContents() const { return Contents; } 126 127 /// @} 128 /// @name Fixup Access 129 /// @{ 130 131 void addFixup(MCFixup Fixup) { 132 // Enforce invariant that fixups are in offset order. 133 assert((Fixups.empty() || Fixup.getOffset() >= Fixups.back().getOffset()) && 134 "Fixups must be added in order!"); 135 Fixups.push_back(Fixup); 136 } 137 138 std::vector<MCFixup> &getFixups() { return Fixups; } 139 const std::vector<MCFixup> &getFixups() const { return Fixups; } 140 141 fixup_iterator fixup_begin() { return Fixups.begin(); } 142 const_fixup_iterator fixup_begin() const { return Fixups.begin(); } 143 144 fixup_iterator fixup_end() {return Fixups.end();} 145 const_fixup_iterator fixup_end() const {return Fixups.end();} 146 147 size_t fixup_size() const { return Fixups.size(); } 148 149 /// @} 150 151 static bool classof(const MCFragment *F) { 152 return F->getKind() == MCFragment::FT_Data; 153 } 154 static bool classof(const MCDataFragment *) { return true; } 155}; 156 157// FIXME: This current incarnation of MCInstFragment doesn't make much sense, as 158// it is almost entirely a duplicate of MCDataFragment. If we decide to stick 159// with this approach (as opposed to making MCInstFragment a very light weight 160// object with just the MCInst and a code size, then we should just change 161// MCDataFragment to have an optional MCInst at its end. 162class MCInstFragment : public MCFragment { 163 virtual void anchor(); 164 165 /// Inst - The instruction this is a fragment for. 166 MCInst Inst; 167 168 /// Code - Binary data for the currently encoded instruction. 169 SmallString<8> Code; 170 171 /// Fixups - The list of fixups in this fragment. 172 SmallVector<MCFixup, 1> Fixups; 173 174public: 175 typedef SmallVectorImpl<MCFixup>::const_iterator const_fixup_iterator; 176 typedef SmallVectorImpl<MCFixup>::iterator fixup_iterator; 177 178public: 179 MCInstFragment(const MCInst &_Inst, MCSectionData *SD = 0) 180 : MCFragment(FT_Inst, SD), Inst(_Inst) { 181 } 182 183 /// @name Accessors 184 /// @{ 185 186 SmallVectorImpl<char> &getCode() { return Code; } 187 const SmallVectorImpl<char> &getCode() const { return Code; } 188 189 unsigned getInstSize() const { return Code.size(); } 190 191 MCInst &getInst() { return Inst; } 192 const MCInst &getInst() const { return Inst; } 193 194 void setInst(const MCInst& Value) { Inst = Value; } 195 196 /// @} 197 /// @name Fixup Access 198 /// @{ 199 200 SmallVectorImpl<MCFixup> &getFixups() { return Fixups; } 201 const SmallVectorImpl<MCFixup> &getFixups() const { return Fixups; } 202 203 fixup_iterator fixup_begin() { return Fixups.begin(); } 204 const_fixup_iterator fixup_begin() const { return Fixups.begin(); } 205 206 fixup_iterator fixup_end() {return Fixups.end();} 207 const_fixup_iterator fixup_end() const {return Fixups.end();} 208 209 size_t fixup_size() const { return Fixups.size(); } 210 211 /// @} 212 213 static bool classof(const MCFragment *F) { 214 return F->getKind() == MCFragment::FT_Inst; 215 } 216 static bool classof(const MCInstFragment *) { return true; } 217}; 218 219class MCAlignFragment : public MCFragment { 220 virtual void anchor(); 221 222 /// Alignment - The alignment to ensure, in bytes. 223 unsigned Alignment; 224 225 /// Value - Value to use for filling padding bytes. 226 int64_t Value; 227 228 /// ValueSize - The size of the integer (in bytes) of \p Value. 229 unsigned ValueSize; 230 231 /// MaxBytesToEmit - The maximum number of bytes to emit; if the alignment 232 /// cannot be satisfied in this width then this fragment is ignored. 233 unsigned MaxBytesToEmit; 234 235 /// EmitNops - Flag to indicate that (optimal) NOPs should be emitted instead 236 /// of using the provided value. The exact interpretation of this flag is 237 /// target dependent. 238 bool EmitNops : 1; 239 240public: 241 MCAlignFragment(unsigned _Alignment, int64_t _Value, unsigned _ValueSize, 242 unsigned _MaxBytesToEmit, MCSectionData *SD = 0) 243 : MCFragment(FT_Align, SD), Alignment(_Alignment), 244 Value(_Value),ValueSize(_ValueSize), 245 MaxBytesToEmit(_MaxBytesToEmit), EmitNops(false) {} 246 247 /// @name Accessors 248 /// @{ 249 250 unsigned getAlignment() const { return Alignment; } 251 252 int64_t getValue() const { return Value; } 253 254 unsigned getValueSize() const { return ValueSize; } 255 256 unsigned getMaxBytesToEmit() const { return MaxBytesToEmit; } 257 258 bool hasEmitNops() const { return EmitNops; } 259 void setEmitNops(bool Value) { EmitNops = Value; } 260 261 /// @} 262 263 static bool classof(const MCFragment *F) { 264 return F->getKind() == MCFragment::FT_Align; 265 } 266 static bool classof(const MCAlignFragment *) { return true; } 267}; 268 269class MCFillFragment : public MCFragment { 270 virtual void anchor(); 271 272 /// Value - Value to use for filling bytes. 273 int64_t Value; 274 275 /// ValueSize - The size (in bytes) of \p Value to use when filling, or 0 if 276 /// this is a virtual fill fragment. 277 unsigned ValueSize; 278 279 /// Size - The number of bytes to insert. 280 uint64_t Size; 281 282public: 283 MCFillFragment(int64_t _Value, unsigned _ValueSize, uint64_t _Size, 284 MCSectionData *SD = 0) 285 : MCFragment(FT_Fill, SD), 286 Value(_Value), ValueSize(_ValueSize), Size(_Size) { 287 assert((!ValueSize || (Size % ValueSize) == 0) && 288 "Fill size must be a multiple of the value size!"); 289 } 290 291 /// @name Accessors 292 /// @{ 293 294 int64_t getValue() const { return Value; } 295 296 unsigned getValueSize() const { return ValueSize; } 297 298 uint64_t getSize() const { return Size; } 299 300 /// @} 301 302 static bool classof(const MCFragment *F) { 303 return F->getKind() == MCFragment::FT_Fill; 304 } 305 static bool classof(const MCFillFragment *) { return true; } 306}; 307 308class MCOrgFragment : public MCFragment { 309 virtual void anchor(); 310 311 /// Offset - The offset this fragment should start at. 312 const MCExpr *Offset; 313 314 /// Value - Value to use for filling bytes. 315 int8_t Value; 316 317public: 318 MCOrgFragment(const MCExpr &_Offset, int8_t _Value, MCSectionData *SD = 0) 319 : MCFragment(FT_Org, SD), 320 Offset(&_Offset), Value(_Value) {} 321 322 /// @name Accessors 323 /// @{ 324 325 const MCExpr &getOffset() const { return *Offset; } 326 327 uint8_t getValue() const { return Value; } 328 329 /// @} 330 331 static bool classof(const MCFragment *F) { 332 return F->getKind() == MCFragment::FT_Org; 333 } 334 static bool classof(const MCOrgFragment *) { return true; } 335}; 336 337class MCLEBFragment : public MCFragment { 338 virtual void anchor(); 339 340 /// Value - The value this fragment should contain. 341 const MCExpr *Value; 342 343 /// IsSigned - True if this is a sleb128, false if uleb128. 344 bool IsSigned; 345 346 SmallString<8> Contents; 347public: 348 MCLEBFragment(const MCExpr &Value_, bool IsSigned_, MCSectionData *SD) 349 : MCFragment(FT_LEB, SD), 350 Value(&Value_), IsSigned(IsSigned_) { Contents.push_back(0); } 351 352 /// @name Accessors 353 /// @{ 354 355 const MCExpr &getValue() const { return *Value; } 356 357 bool isSigned() const { return IsSigned; } 358 359 SmallString<8> &getContents() { return Contents; } 360 const SmallString<8> &getContents() const { return Contents; } 361 362 /// @} 363 364 static bool classof(const MCFragment *F) { 365 return F->getKind() == MCFragment::FT_LEB; 366 } 367 static bool classof(const MCLEBFragment *) { return true; } 368}; 369 370class MCDwarfLineAddrFragment : public MCFragment { 371 virtual void anchor(); 372 373 /// LineDelta - the value of the difference between the two line numbers 374 /// between two .loc dwarf directives. 375 int64_t LineDelta; 376 377 /// AddrDelta - The expression for the difference of the two symbols that 378 /// make up the address delta between two .loc dwarf directives. 379 const MCExpr *AddrDelta; 380 381 SmallString<8> Contents; 382 383public: 384 MCDwarfLineAddrFragment(int64_t _LineDelta, const MCExpr &_AddrDelta, 385 MCSectionData *SD) 386 : MCFragment(FT_Dwarf, SD), 387 LineDelta(_LineDelta), AddrDelta(&_AddrDelta) { Contents.push_back(0); } 388 389 /// @name Accessors 390 /// @{ 391 392 int64_t getLineDelta() const { return LineDelta; } 393 394 const MCExpr &getAddrDelta() const { return *AddrDelta; } 395 396 SmallString<8> &getContents() { return Contents; } 397 const SmallString<8> &getContents() const { return Contents; } 398 399 /// @} 400 401 static bool classof(const MCFragment *F) { 402 return F->getKind() == MCFragment::FT_Dwarf; 403 } 404 static bool classof(const MCDwarfLineAddrFragment *) { return true; } 405}; 406 407class MCDwarfCallFrameFragment : public MCFragment { 408 virtual void anchor(); 409 410 /// AddrDelta - The expression for the difference of the two symbols that 411 /// make up the address delta between two .cfi_* dwarf directives. 412 const MCExpr *AddrDelta; 413 414 SmallString<8> Contents; 415 416public: 417 MCDwarfCallFrameFragment(const MCExpr &_AddrDelta, MCSectionData *SD) 418 : MCFragment(FT_DwarfFrame, SD), 419 AddrDelta(&_AddrDelta) { Contents.push_back(0); } 420 421 /// @name Accessors 422 /// @{ 423 424 const MCExpr &getAddrDelta() const { return *AddrDelta; } 425 426 SmallString<8> &getContents() { return Contents; } 427 const SmallString<8> &getContents() const { return Contents; } 428 429 /// @} 430 431 static bool classof(const MCFragment *F) { 432 return F->getKind() == MCFragment::FT_DwarfFrame; 433 } 434 static bool classof(const MCDwarfCallFrameFragment *) { return true; } 435}; 436 437// FIXME: Should this be a separate class, or just merged into MCSection? Since 438// we anticipate the fast path being through an MCAssembler, the only reason to 439// keep it out is for API abstraction. 440class MCSectionData : public ilist_node<MCSectionData> { 441 friend class MCAsmLayout; 442 443 MCSectionData(const MCSectionData&); // DO NOT IMPLEMENT 444 void operator=(const MCSectionData&); // DO NOT IMPLEMENT 445 446public: 447 typedef iplist<MCFragment> FragmentListType; 448 449 typedef FragmentListType::const_iterator const_iterator; 450 typedef FragmentListType::iterator iterator; 451 452 typedef FragmentListType::const_reverse_iterator const_reverse_iterator; 453 typedef FragmentListType::reverse_iterator reverse_iterator; 454 455private: 456 FragmentListType Fragments; 457 const MCSection *Section; 458 459 /// Ordinal - The section index in the assemblers section list. 460 unsigned Ordinal; 461 462 /// LayoutOrder - The index of this section in the layout order. 463 unsigned LayoutOrder; 464 465 /// Alignment - The maximum alignment seen in this section. 466 unsigned Alignment; 467 468 /// @name Assembler Backend Data 469 /// @{ 470 // 471 // FIXME: This could all be kept private to the assembler implementation. 472 473 /// HasInstructions - Whether this section has had instructions emitted into 474 /// it. 475 unsigned HasInstructions : 1; 476 477 /// @} 478 479public: 480 // Only for use as sentinel. 481 MCSectionData(); 482 MCSectionData(const MCSection &Section, MCAssembler *A = 0); 483 484 const MCSection &getSection() const { return *Section; } 485 486 unsigned getAlignment() const { return Alignment; } 487 void setAlignment(unsigned Value) { Alignment = Value; } 488 489 bool hasInstructions() const { return HasInstructions; } 490 void setHasInstructions(bool Value) { HasInstructions = Value; } 491 492 unsigned getOrdinal() const { return Ordinal; } 493 void setOrdinal(unsigned Value) { Ordinal = Value; } 494 495 unsigned getLayoutOrder() const { return LayoutOrder; } 496 void setLayoutOrder(unsigned Value) { LayoutOrder = Value; } 497 498 /// @name Fragment Access 499 /// @{ 500 501 const FragmentListType &getFragmentList() const { return Fragments; } 502 FragmentListType &getFragmentList() { return Fragments; } 503 504 iterator begin() { return Fragments.begin(); } 505 const_iterator begin() const { return Fragments.begin(); } 506 507 iterator end() { return Fragments.end(); } 508 const_iterator end() const { return Fragments.end(); } 509 510 reverse_iterator rbegin() { return Fragments.rbegin(); } 511 const_reverse_iterator rbegin() const { return Fragments.rbegin(); } 512 513 reverse_iterator rend() { return Fragments.rend(); } 514 const_reverse_iterator rend() const { return Fragments.rend(); } 515 516 size_t size() const { return Fragments.size(); } 517 518 bool empty() const { return Fragments.empty(); } 519 520 void dump(); 521 522 /// @} 523}; 524 525// FIXME: Same concerns as with SectionData. 526class MCSymbolData : public ilist_node<MCSymbolData> { 527public: 528 const MCSymbol *Symbol; 529 530 /// Fragment - The fragment this symbol's value is relative to, if any. 531 MCFragment *Fragment; 532 533 /// Offset - The offset to apply to the fragment address to form this symbol's 534 /// value. 535 uint64_t Offset; 536 537 /// IsExternal - True if this symbol is visible outside this translation 538 /// unit. 539 unsigned IsExternal : 1; 540 541 /// IsPrivateExtern - True if this symbol is private extern. 542 unsigned IsPrivateExtern : 1; 543 544 /// CommonSize - The size of the symbol, if it is 'common', or 0. 545 // 546 // FIXME: Pack this in with other fields? We could put it in offset, since a 547 // common symbol can never get a definition. 548 uint64_t CommonSize; 549 550 /// SymbolSize - An expression describing how to calculate the size of 551 /// a symbol. If a symbol has no size this field will be NULL. 552 const MCExpr *SymbolSize; 553 554 /// CommonAlign - The alignment of the symbol, if it is 'common'. 555 // 556 // FIXME: Pack this in with other fields? 557 unsigned CommonAlign; 558 559 /// Flags - The Flags field is used by object file implementations to store 560 /// additional per symbol information which is not easily classified. 561 uint32_t Flags; 562 563 /// Index - Index field, for use by the object file implementation. 564 uint64_t Index; 565 566public: 567 // Only for use as sentinel. 568 MCSymbolData(); 569 MCSymbolData(const MCSymbol &_Symbol, MCFragment *_Fragment, uint64_t _Offset, 570 MCAssembler *A = 0); 571 572 /// @name Accessors 573 /// @{ 574 575 const MCSymbol &getSymbol() const { return *Symbol; } 576 577 MCFragment *getFragment() const { return Fragment; } 578 void setFragment(MCFragment *Value) { Fragment = Value; } 579 580 uint64_t getOffset() const { return Offset; } 581 void setOffset(uint64_t Value) { Offset = Value; } 582 583 /// @} 584 /// @name Symbol Attributes 585 /// @{ 586 587 bool isExternal() const { return IsExternal; } 588 void setExternal(bool Value) { IsExternal = Value; } 589 590 bool isPrivateExtern() const { return IsPrivateExtern; } 591 void setPrivateExtern(bool Value) { IsPrivateExtern = Value; } 592 593 /// isCommon - Is this a 'common' symbol. 594 bool isCommon() const { return CommonSize != 0; } 595 596 /// setCommon - Mark this symbol as being 'common'. 597 /// 598 /// \param Size - The size of the symbol. 599 /// \param Align - The alignment of the symbol. 600 void setCommon(uint64_t Size, unsigned Align) { 601 CommonSize = Size; 602 CommonAlign = Align; 603 } 604 605 /// getCommonSize - Return the size of a 'common' symbol. 606 uint64_t getCommonSize() const { 607 assert(isCommon() && "Not a 'common' symbol!"); 608 return CommonSize; 609 } 610 611 void setSize(const MCExpr *SS) { 612 SymbolSize = SS; 613 } 614 615 const MCExpr *getSize() const { 616 return SymbolSize; 617 } 618 619 620 /// getCommonAlignment - Return the alignment of a 'common' symbol. 621 unsigned getCommonAlignment() const { 622 assert(isCommon() && "Not a 'common' symbol!"); 623 return CommonAlign; 624 } 625 626 /// getFlags - Get the (implementation defined) symbol flags. 627 uint32_t getFlags() const { return Flags; } 628 629 /// setFlags - Set the (implementation defined) symbol flags. 630 void setFlags(uint32_t Value) { Flags = Value; } 631 632 /// modifyFlags - Modify the flags via a mask 633 void modifyFlags(uint32_t Value, uint32_t Mask) { 634 Flags = (Flags & ~Mask) | Value; 635 } 636 637 /// getIndex - Get the (implementation defined) index. 638 uint64_t getIndex() const { return Index; } 639 640 /// setIndex - Set the (implementation defined) index. 641 void setIndex(uint64_t Value) { Index = Value; } 642 643 /// @} 644 645 void dump(); 646}; 647 648// FIXME: This really doesn't belong here. See comments below. 649struct IndirectSymbolData { 650 MCSymbol *Symbol; 651 MCSectionData *SectionData; 652}; 653 654// FIXME: Ditto this. Purely so the Streamer and the ObjectWriter can talk 655// to one another. 656struct DataRegionData { 657 // This enum should be kept in sync w/ the mach-o definition in 658 // llvm/Object/MachOFormat.h. 659 enum KindTy { Data = 1, JumpTable8, JumpTable16, JumpTable32 } Kind; 660 MCSymbol *Start; 661 MCSymbol *End; 662}; 663 664class MCAssembler { 665 friend class MCAsmLayout; 666 667public: 668 typedef iplist<MCSectionData> SectionDataListType; 669 typedef iplist<MCSymbolData> SymbolDataListType; 670 671 typedef SectionDataListType::const_iterator const_iterator; 672 typedef SectionDataListType::iterator iterator; 673 674 typedef SymbolDataListType::const_iterator const_symbol_iterator; 675 typedef SymbolDataListType::iterator symbol_iterator; 676 677 typedef std::vector<IndirectSymbolData>::const_iterator 678 const_indirect_symbol_iterator; 679 typedef std::vector<IndirectSymbolData>::iterator indirect_symbol_iterator; 680 681 typedef std::vector<DataRegionData>::const_iterator 682 const_data_region_iterator; 683 typedef std::vector<DataRegionData>::iterator data_region_iterator; 684 685private: 686 MCAssembler(const MCAssembler&); // DO NOT IMPLEMENT 687 void operator=(const MCAssembler&); // DO NOT IMPLEMENT 688 689 MCContext &Context; 690 691 MCAsmBackend &Backend; 692 693 MCCodeEmitter &Emitter; 694 695 MCObjectWriter &Writer; 696 697 raw_ostream &OS; 698 699 iplist<MCSectionData> Sections; 700 701 iplist<MCSymbolData> Symbols; 702 703 /// The map of sections to their associated assembler backend data. 704 // 705 // FIXME: Avoid this indirection? 706 DenseMap<const MCSection*, MCSectionData*> SectionMap; 707 708 /// The map of symbols to their associated assembler backend data. 709 // 710 // FIXME: Avoid this indirection? 711 DenseMap<const MCSymbol*, MCSymbolData*> SymbolMap; 712 713 std::vector<IndirectSymbolData> IndirectSymbols; 714 715 std::vector<DataRegionData> DataRegions; 716 /// The set of function symbols for which a .thumb_func directive has 717 /// been seen. 718 // 719 // FIXME: We really would like this in target specific code rather than 720 // here. Maybe when the relocation stuff moves to target specific, 721 // this can go with it? The streamer would need some target specific 722 // refactoring too. 723 SmallPtrSet<const MCSymbol*, 64> ThumbFuncs; 724 725 unsigned RelaxAll : 1; 726 unsigned NoExecStack : 1; 727 unsigned SubsectionsViaSymbols : 1; 728 729private: 730 /// Evaluate a fixup to a relocatable expression and the value which should be 731 /// placed into the fixup. 732 /// 733 /// \param Layout The layout to use for evaluation. 734 /// \param Fixup The fixup to evaluate. 735 /// \param DF The fragment the fixup is inside. 736 /// \param Target [out] On return, the relocatable expression the fixup 737 /// evaluates to. 738 /// \param Value [out] On return, the value of the fixup as currently laid 739 /// out. 740 /// \return Whether the fixup value was fully resolved. This is true if the 741 /// \p Value result is fixed, otherwise the value may change due to 742 /// relocation. 743 bool evaluateFixup(const MCAsmLayout &Layout, 744 const MCFixup &Fixup, const MCFragment *DF, 745 MCValue &Target, uint64_t &Value) const; 746 747 /// Check whether a fixup can be satisfied, or whether it needs to be relaxed 748 /// (increased in size, in order to hold its value correctly). 749 bool fixupNeedsRelaxation(const MCFixup &Fixup, const MCInstFragment *DF, 750 const MCAsmLayout &Layout) const; 751 752 /// Check whether the given fragment needs relaxation. 753 bool fragmentNeedsRelaxation(const MCInstFragment *IF, 754 const MCAsmLayout &Layout) const; 755 756 /// layoutOnce - Perform one layout iteration and return true if any offsets 757 /// were adjusted. 758 bool layoutOnce(MCAsmLayout &Layout); 759 760 bool layoutSectionOnce(MCAsmLayout &Layout, MCSectionData &SD); 761 762 bool relaxInstruction(MCAsmLayout &Layout, MCInstFragment &IF); 763 764 bool relaxLEB(MCAsmLayout &Layout, MCLEBFragment &IF); 765 766 bool relaxDwarfLineAddr(MCAsmLayout &Layout, MCDwarfLineAddrFragment &DF); 767 bool relaxDwarfCallFrameFragment(MCAsmLayout &Layout, 768 MCDwarfCallFrameFragment &DF); 769 770 /// finishLayout - Finalize a layout, including fragment lowering. 771 void finishLayout(MCAsmLayout &Layout); 772 773 uint64_t handleFixup(const MCAsmLayout &Layout, 774 MCFragment &F, const MCFixup &Fixup); 775 776public: 777 /// Compute the effective fragment size assuming it is laid out at the given 778 /// \p SectionAddress and \p FragmentOffset. 779 uint64_t computeFragmentSize(const MCAsmLayout &Layout, 780 const MCFragment &F) const; 781 782 /// Find the symbol which defines the atom containing the given symbol, or 783 /// null if there is no such symbol. 784 const MCSymbolData *getAtom(const MCSymbolData *Symbol) const; 785 786 /// Check whether a particular symbol is visible to the linker and is required 787 /// in the symbol table, or whether it can be discarded by the assembler. This 788 /// also effects whether the assembler treats the label as potentially 789 /// defining a separate atom. 790 bool isSymbolLinkerVisible(const MCSymbol &SD) const; 791 792 /// Emit the section contents using the given object writer. 793 void writeSectionData(const MCSectionData *Section, 794 const MCAsmLayout &Layout) const; 795 796 /// Check whether a given symbol has been flagged with .thumb_func. 797 bool isThumbFunc(const MCSymbol *Func) const { 798 return ThumbFuncs.count(Func); 799 } 800 801 /// Flag a function symbol as the target of a .thumb_func directive. 802 void setIsThumbFunc(const MCSymbol *Func) { ThumbFuncs.insert(Func); } 803 804public: 805 /// Construct a new assembler instance. 806 /// 807 /// \param OS The stream to output to. 808 // 809 // FIXME: How are we going to parameterize this? Two obvious options are stay 810 // concrete and require clients to pass in a target like object. The other 811 // option is to make this abstract, and have targets provide concrete 812 // implementations as we do with AsmParser. 813 MCAssembler(MCContext &Context_, MCAsmBackend &Backend_, 814 MCCodeEmitter &Emitter_, MCObjectWriter &Writer_, 815 raw_ostream &OS); 816 ~MCAssembler(); 817 818 MCContext &getContext() const { return Context; } 819 820 MCAsmBackend &getBackend() const { return Backend; } 821 822 MCCodeEmitter &getEmitter() const { return Emitter; } 823 824 MCObjectWriter &getWriter() const { return Writer; } 825 826 /// Finish - Do final processing and write the object to the output stream. 827 /// \p Writer is used for custom object writer (as the MCJIT does), 828 /// if not specified it is automatically created from backend. 829 void Finish(); 830 831 // FIXME: This does not belong here. 832 bool getSubsectionsViaSymbols() const { 833 return SubsectionsViaSymbols; 834 } 835 void setSubsectionsViaSymbols(bool Value) { 836 SubsectionsViaSymbols = Value; 837 } 838 839 bool getRelaxAll() const { return RelaxAll; } 840 void setRelaxAll(bool Value) { RelaxAll = Value; } 841 842 bool getNoExecStack() const { return NoExecStack; } 843 void setNoExecStack(bool Value) { NoExecStack = Value; } 844 845 /// @name Section List Access 846 /// @{ 847 848 const SectionDataListType &getSectionList() const { return Sections; } 849 SectionDataListType &getSectionList() { return Sections; } 850 851 iterator begin() { return Sections.begin(); } 852 const_iterator begin() const { return Sections.begin(); } 853 854 iterator end() { return Sections.end(); } 855 const_iterator end() const { return Sections.end(); } 856 857 size_t size() const { return Sections.size(); } 858 859 /// @} 860 /// @name Symbol List Access 861 /// @{ 862 863 const SymbolDataListType &getSymbolList() const { return Symbols; } 864 SymbolDataListType &getSymbolList() { return Symbols; } 865 866 symbol_iterator symbol_begin() { return Symbols.begin(); } 867 const_symbol_iterator symbol_begin() const { return Symbols.begin(); } 868 869 symbol_iterator symbol_end() { return Symbols.end(); } 870 const_symbol_iterator symbol_end() const { return Symbols.end(); } 871 872 size_t symbol_size() const { return Symbols.size(); } 873 874 /// @} 875 /// @name Indirect Symbol List Access 876 /// @{ 877 878 // FIXME: This is a total hack, this should not be here. Once things are 879 // factored so that the streamer has direct access to the .o writer, it can 880 // disappear. 881 std::vector<IndirectSymbolData> &getIndirectSymbols() { 882 return IndirectSymbols; 883 } 884 885 indirect_symbol_iterator indirect_symbol_begin() { 886 return IndirectSymbols.begin(); 887 } 888 const_indirect_symbol_iterator indirect_symbol_begin() const { 889 return IndirectSymbols.begin(); 890 } 891 892 indirect_symbol_iterator indirect_symbol_end() { 893 return IndirectSymbols.end(); 894 } 895 const_indirect_symbol_iterator indirect_symbol_end() const { 896 return IndirectSymbols.end(); 897 } 898 899 size_t indirect_symbol_size() const { return IndirectSymbols.size(); } 900 901 /// @} 902 /// @name Data Region List Access 903 /// @{ 904 905 // FIXME: This is a total hack, this should not be here. Once things are 906 // factored so that the streamer has direct access to the .o writer, it can 907 // disappear. 908 std::vector<DataRegionData> &getDataRegions() { 909 return DataRegions; 910 } 911 912 data_region_iterator data_region_begin() { 913 return DataRegions.begin(); 914 } 915 const_data_region_iterator data_region_begin() const { 916 return DataRegions.begin(); 917 } 918 919 data_region_iterator data_region_end() { 920 return DataRegions.end(); 921 } 922 const_data_region_iterator data_region_end() const { 923 return DataRegions.end(); 924 } 925 926 size_t data_region_size() const { return DataRegions.size(); } 927 928 /// @} 929 /// @name Backend Data Access 930 /// @{ 931 932 MCSectionData &getSectionData(const MCSection &Section) const { 933 MCSectionData *Entry = SectionMap.lookup(&Section); 934 assert(Entry && "Missing section data!"); 935 return *Entry; 936 } 937 938 MCSectionData &getOrCreateSectionData(const MCSection &Section, 939 bool *Created = 0) { 940 MCSectionData *&Entry = SectionMap[&Section]; 941 942 if (Created) *Created = !Entry; 943 if (!Entry) 944 Entry = new MCSectionData(Section, this); 945 946 return *Entry; 947 } 948 949 MCSymbolData &getSymbolData(const MCSymbol &Symbol) const { 950 MCSymbolData *Entry = SymbolMap.lookup(&Symbol); 951 assert(Entry && "Missing symbol data!"); 952 return *Entry; 953 } 954 955 MCSymbolData &getOrCreateSymbolData(const MCSymbol &Symbol, 956 bool *Created = 0) { 957 MCSymbolData *&Entry = SymbolMap[&Symbol]; 958 959 if (Created) *Created = !Entry; 960 if (!Entry) 961 Entry = new MCSymbolData(Symbol, 0, 0, this); 962 963 return *Entry; 964 } 965 966 /// @} 967 968 void dump(); 969}; 970 971} // end namespace llvm 972 973#endif 974