llvm/lib/CodeGen/AsmPrinter/DIE.cpp

   1 //===--- lib/CodeGen/DIE.cpp - DWARF Info Entries -------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // Data structures for DWARF info entries.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "llvm/CodeGen/DIE.h"
  14 #include "DwarfCompileUnit.h"
  15 #include "DwarfDebug.h"
  16 #include "DwarfUnit.h"
  17 #include "llvm/ADT/Twine.h"
  18 #include "llvm/CodeGen/AsmPrinter.h"
  19 #include "llvm/Config/llvm-config.h"
  20 #include "llvm/IR/DataLayout.h"
  21 #include "llvm/MC/MCAsmInfo.h"
  22 #include "llvm/MC/MCContext.h"
  23 #include "llvm/MC/MCStreamer.h"
  24 #include "llvm/MC/MCSymbol.h"
  25 #include "llvm/Support/Debug.h"
  26 #include "llvm/Support/ErrorHandling.h"
  27 #include "llvm/Support/Format.h"
  28 #include "llvm/Support/FormattedStream.h"
  29 #include "llvm/Support/LEB128.h"
  30 #include "llvm/Support/MD5.h"
  31 #include "llvm/Support/raw_ostream.h"
  32 using namespace llvm;
  33
  34 #define DEBUG_TYPE "dwarfdebug"
  35
  36 //===----------------------------------------------------------------------===//
  37 // DIEAbbrevData Implementation
  38 //===----------------------------------------------------------------------===//
  39
  40 /// Profile - Used to gather unique data for the abbreviation folding set.
  41 ///
  42 void DIEAbbrevData::Profile(FoldingSetNodeID &ID) const {
  43   // Explicitly cast to an integer type for which FoldingSetNodeID has
  44   // overloads.  Otherwise MSVC 2010 thinks this call is ambiguous.
  45   ID.AddInteger(unsigned(Attribute));
  46   ID.AddInteger(unsigned(Form));
  47   if (Form == dwarf::DW_FORM_implicit_const)
  48     ID.AddInteger(Value);
  49 }
  50
  51 //===----------------------------------------------------------------------===//
  52 // DIEAbbrev Implementation
  53 //===----------------------------------------------------------------------===//
  54
  55 /// Profile - Used to gather unique data for the abbreviation folding set.
  56 ///
  57 void DIEAbbrev::Profile(FoldingSetNodeID &ID) const {
  58   ID.AddInteger(unsigned(Tag));
  59   ID.AddInteger(unsigned(Children));
  60
  61   // For each attribute description.
  62   for (unsigned i = 0, N = Data.size(); i < N; ++i)
  63     Data[i].Profile(ID);
  64 }
  65
  66 /// Emit - Print the abbreviation using the specified asm printer.
  67 ///
  68 void DIEAbbrev::Emit(const AsmPrinter *AP) const {
  69   // Emit its Dwarf tag type.
  70   AP->emitULEB128(Tag, dwarf::TagString(Tag).data());
  71
  72   // Emit whether it has children DIEs.
  73   AP->emitULEB128((unsigned)Children, dwarf::ChildrenString(Children).data());
  74
  75   // For each attribute description.
  76   for (unsigned i = 0, N = Data.size(); i < N; ++i) {
  77     const DIEAbbrevData &AttrData = Data[i];
  78
  79     // Emit attribute type.
  80     AP->emitULEB128(AttrData.getAttribute(),
  81                     dwarf::AttributeString(AttrData.getAttribute()).data());
  82
  83     // Emit form type.
  84 #ifndef NDEBUG
  85     // Could be an assertion, but this way we can see the failing form code
  86     // easily, which helps track down where it came from.
  87     if (!dwarf::isValidFormForVersion(AttrData.getForm(),
  88                                       AP->getDwarfVersion())) {
  89       LLVM_DEBUG(dbgs() << "Invalid form " << format("0x%x", AttrData.getForm())
  90                         << " for DWARF version " << AP->getDwarfVersion()
  91                         << "\n");
  92       llvm_unreachable("Invalid form for specified DWARF version");
  93     }
  94 #endif
  95     AP->emitULEB128(AttrData.getForm(),
  96                     dwarf::FormEncodingString(AttrData.getForm()).data());
  97
  98     // Emit value for DW_FORM_implicit_const.
  99     if (AttrData.getForm() == dwarf::DW_FORM_implicit_const)
 100       AP->emitSLEB128(AttrData.getValue());
 101   }
 102
 103   // Mark end of abbreviation.
 104   AP->emitULEB128(0, "EOM(1)");
 105   AP->emitULEB128(0, "EOM(2)");
 106 }
 107
 108 LLVM_DUMP_METHOD
 109 void DIEAbbrev::print(raw_ostream &O) const {
 110   O << "Abbreviation @"
 111     << format("0x%lx", (long)(intptr_t)this)
 112     << "  "
 113     << dwarf::TagString(Tag)
 114     << " "
 115     << dwarf::ChildrenString(Children)
 116     << '\n';
 117
 118   for (unsigned i = 0, N = Data.size(); i < N; ++i) {
 119     O << "  "
 120       << dwarf::AttributeString(Data[i].getAttribute())
 121       << "  "
 122       << dwarf::FormEncodingString(Data[i].getForm());
 123
 124     if (Data[i].getForm() == dwarf::DW_FORM_implicit_const)
 125       O << " " << Data[i].getValue();
 126
 127     O << '\n';
 128   }
 129 }
 130
 131 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
 132 LLVM_DUMP_METHOD void DIEAbbrev::dump() const {
 133   print(dbgs());
 134 }
 135 #endif
 136
 137 //===----------------------------------------------------------------------===//
 138 // DIEAbbrevSet Implementation
 139 //===----------------------------------------------------------------------===//
 140
 141 DIEAbbrevSet::~DIEAbbrevSet() {
 142   for (DIEAbbrev *Abbrev : Abbreviations)
 143     Abbrev->~DIEAbbrev();
 144 }
 145
 146 DIEAbbrev &DIEAbbrevSet::uniqueAbbreviation(DIE &Die) {
 147
 148   FoldingSetNodeID ID;
 149   DIEAbbrev Abbrev = Die.generateAbbrev();
 150   Abbrev.Profile(ID);
 151
 152   void *InsertPos;
 153   if (DIEAbbrev *Existing =
 154           AbbreviationsSet.FindNodeOrInsertPos(ID, InsertPos)) {
 155     Die.setAbbrevNumber(Existing->getNumber());
 156     return *Existing;
 157   }
 158
 159   // Move the abbreviation to the heap and assign a number.
 160   DIEAbbrev *New = new (Alloc) DIEAbbrev(std::move(Abbrev));
 161   Abbreviations.push_back(New);
 162   New->setNumber(Abbreviations.size());
 163   Die.setAbbrevNumber(Abbreviations.size());
 164
 165   // Store it for lookup.
 166   AbbreviationsSet.InsertNode(New, InsertPos);
 167   return *New;
 168 }
 169
 170 void DIEAbbrevSet::Emit(const AsmPrinter *AP, MCSection *Section) const {
 171   if (!Abbreviations.empty()) {
 172     // Start the debug abbrev section.
 173     AP->OutStreamer->SwitchSection(Section);
 174     AP->emitDwarfAbbrevs(Abbreviations);
 175   }
 176 }
 177
 178 //===----------------------------------------------------------------------===//
 179 // DIE Implementation
 180 //===----------------------------------------------------------------------===//
 181
 182 DIE *DIE::getParent() const {
 183   return Owner.dyn_cast<DIE*>();
 184 }
 185
 186 DIEAbbrev DIE::generateAbbrev() const {
 187   DIEAbbrev Abbrev(Tag, hasChildren());
 188   for (const DIEValue &V : values())
 189     if (V.getForm() == dwarf::DW_FORM_implicit_const)
 190       Abbrev.AddImplicitConstAttribute(V.getAttribute(),
 191                                        V.getDIEInteger().getValue());
 192     else
 193       Abbrev.AddAttribute(V.getAttribute(), V.getForm());
 194   return Abbrev;
 195 }
 196
 197 uint64_t DIE::getDebugSectionOffset() const {
 198   const DIEUnit *Unit = getUnit();
 199   assert(Unit && "DIE must be owned by a DIEUnit to get its absolute offset");
 200   return Unit->getDebugSectionOffset() + getOffset();
 201 }
 202
 203 const DIE *DIE::getUnitDie() const {
 204   const DIE *p = this;
 205   while (p) {
 206     if (p->getTag() == dwarf::DW_TAG_compile_unit ||
 207         p->getTag() == dwarf::DW_TAG_type_unit)
 208       return p;
 209     p = p->getParent();
 210   }
 211   return nullptr;
 212 }
 213
 214 DIEUnit *DIE::getUnit() const {
 215   const DIE *UnitDie = getUnitDie();
 216   if (UnitDie)
 217     return UnitDie->Owner.dyn_cast<DIEUnit*>();
 218   return nullptr;
 219 }
 220
 221 DIEValue DIE::findAttribute(dwarf::Attribute Attribute) const {
 222   // Iterate through all the attributes until we find the one we're
 223   // looking for, if we can't find it return NULL.
 224   for (const auto &V : values())
 225     if (V.getAttribute() == Attribute)
 226       return V;
 227   return DIEValue();
 228 }
 229
 230 LLVM_DUMP_METHOD
 231 static void printValues(raw_ostream &O, const DIEValueList &Values,
 232                         StringRef Type, unsigned Size, unsigned IndentCount) {
 233   O << Type << ": Size: " << Size << "\n";
 234
 235   unsigned I = 0;
 236   const std::string Indent(IndentCount, ' ');
 237   for (const auto &V : Values.values()) {
 238     O << Indent;
 239     O << "Blk[" << I++ << "]";
 240     O << "  " << dwarf::FormEncodingString(V.getForm()) << " ";
 241     V.print(O);
 242     O << "\n";
 243   }
 244 }
 245
 246 LLVM_DUMP_METHOD
 247 void DIE::print(raw_ostream &O, unsigned IndentCount) const {
 248   const std::string Indent(IndentCount, ' ');
 249   O << Indent << "Die: " << format("0x%lx", (long)(intptr_t) this)
 250     << ", Offset: " << Offset << ", Size: " << Size << "\n";
 251
 252   O << Indent << dwarf::TagString(getTag()) << " "
 253     << dwarf::ChildrenString(hasChildren()) << "\n";
 254
 255   IndentCount += 2;
 256   for (const auto &V : values()) {
 257     O << Indent;
 258     O << dwarf::AttributeString(V.getAttribute());
 259     O << "  " << dwarf::FormEncodingString(V.getForm()) << " ";
 260     V.print(O);
 261     O << "\n";
 262   }
 263   IndentCount -= 2;
 264
 265   for (const auto &Child : children())
 266     Child.print(O, IndentCount + 4);
 267
 268   O << "\n";
 269 }
 270
 271 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
 272 LLVM_DUMP_METHOD void DIE::dump() const {
 273   print(dbgs());
 274 }
 275 #endif
 276
 277 unsigned DIE::computeOffsetsAndAbbrevs(const AsmPrinter *AP,
 278                                        DIEAbbrevSet &AbbrevSet,
 279                                        unsigned CUOffset) {
 280   // Unique the abbreviation and fill in the abbreviation number so this DIE
 281   // can be emitted.
 282   const DIEAbbrev &Abbrev = AbbrevSet.uniqueAbbreviation(*this);
 283
 284   // Set compile/type unit relative offset of this DIE.
 285   setOffset(CUOffset);
 286
 287   // Add the byte size of the abbreviation code.
 288   CUOffset += getULEB128Size(getAbbrevNumber());
 289
 290   // Add the byte size of all the DIE attribute values.
 291   for (const auto &V : values())
 292     CUOffset += V.SizeOf(AP);
 293
 294   // Let the children compute their offsets and abbreviation numbers.
 295   if (hasChildren()) {
 296     (void)Abbrev;
 297     assert(Abbrev.hasChildren() && "Children flag not set");
 298
 299     for (auto &Child : children())
 300       CUOffset = Child.computeOffsetsAndAbbrevs(AP, AbbrevSet, CUOffset);
 301
 302     // Each child chain is terminated with a zero byte, adjust the offset.
 303     CUOffset += sizeof(int8_t);
 304   }
 305
 306   // Compute the byte size of this DIE and all of its children correctly. This
 307   // is needed so that top level DIE can help the compile unit set its length
 308   // correctly.
 309   setSize(CUOffset - getOffset());
 310   return CUOffset;
 311 }
 312
 313 //===----------------------------------------------------------------------===//
 314 // DIEUnit Implementation
 315 //===----------------------------------------------------------------------===//
 316 DIEUnit::DIEUnit(dwarf::Tag UnitTag)
 317     : Die(UnitTag), Section(nullptr), Offset(0) {
 318   Die.Owner = this;
 319   assert((UnitTag == dwarf::DW_TAG_compile_unit ||
 320           UnitTag == dwarf::DW_TAG_skeleton_unit ||
 321           UnitTag == dwarf::DW_TAG_type_unit ||
 322           UnitTag == dwarf::DW_TAG_partial_unit) &&
 323          "expected a unit TAG");
 324 }
 325
 326 void DIEValue::emitValue(const AsmPrinter *AP) const {
 327   switch (Ty) {
 328   case isNone:
 329     llvm_unreachable("Expected valid DIEValue");
 330 #define HANDLE_DIEVALUE(T)                                                     \
 331   case is##T:                                                                  \
 332     getDIE##T().emitValue(AP, Form);                                           \
 333     break;
 334 #include "llvm/CodeGen/DIEValue.def"
 335   }
 336 }
 337
 338 unsigned DIEValue::SizeOf(const AsmPrinter *AP) const {
 339   switch (Ty) {
 340   case isNone:
 341     llvm_unreachable("Expected valid DIEValue");
 342 #define HANDLE_DIEVALUE(T)                                                     \
 343   case is##T:                                                                  \
 344     return getDIE##T().SizeOf(AP, Form);
 345 #include "llvm/CodeGen/DIEValue.def"
 346   }
 347   llvm_unreachable("Unknown DIE kind");
 348 }
 349
 350 LLVM_DUMP_METHOD
 351 void DIEValue::print(raw_ostream &O) const {
 352   switch (Ty) {
 353   case isNone:
 354     llvm_unreachable("Expected valid DIEValue");
 355 #define HANDLE_DIEVALUE(T)                                                     \
 356   case is##T:                                                                  \
 357     getDIE##T().print(O);                                                      \
 358     break;
 359 #include "llvm/CodeGen/DIEValue.def"
 360   }
 361 }
 362
 363 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
 364 LLVM_DUMP_METHOD void DIEValue::dump() const {
 365   print(dbgs());
 366 }
 367 #endif
 368
 369 //===----------------------------------------------------------------------===//
 370 // DIEInteger Implementation
 371 //===----------------------------------------------------------------------===//
 372
 373 /// EmitValue - Emit integer of appropriate size.
 374 ///
 375 void DIEInteger::emitValue(const AsmPrinter *Asm, dwarf::Form Form) const {
 376   switch (Form) {
 377   case dwarf::DW_FORM_implicit_const:
 378   case dwarf::DW_FORM_flag_present:
 379     // Emit something to keep the lines and comments in sync.
 380     // FIXME: Is there a better way to do this?
 381     Asm->OutStreamer->AddBlankLine();
 382     return;
 383   case dwarf::DW_FORM_flag:
 384   case dwarf::DW_FORM_ref1:
 385   case dwarf::DW_FORM_data1:
 386   case dwarf::DW_FORM_strx1:
 387   case dwarf::DW_FORM_addrx1:
 388   case dwarf::DW_FORM_ref2:
 389   case dwarf::DW_FORM_data2:
 390   case dwarf::DW_FORM_strx2:
 391   case dwarf::DW_FORM_addrx2:
 392   case dwarf::DW_FORM_strx3:
 393   case dwarf::DW_FORM_strp:
 394   case dwarf::DW_FORM_ref4:
 395   case dwarf::DW_FORM_data4:
 396   case dwarf::DW_FORM_ref_sup4:
 397   case dwarf::DW_FORM_strx4:
 398   case dwarf::DW_FORM_addrx4:
 399   case dwarf::DW_FORM_ref8:
 400   case dwarf::DW_FORM_ref_sig8:
 401   case dwarf::DW_FORM_data8:
 402   case dwarf::DW_FORM_ref_sup8:
 403   case dwarf::DW_FORM_GNU_ref_alt:
 404   case dwarf::DW_FORM_GNU_strp_alt:
 405   case dwarf::DW_FORM_line_strp:
 406   case dwarf::DW_FORM_sec_offset:
 407   case dwarf::DW_FORM_strp_sup:
 408   case dwarf::DW_FORM_addr:
 409   case dwarf::DW_FORM_ref_addr:
 410     Asm->OutStreamer->emitIntValue(Integer, SizeOf(Asm, Form));
 411     return;
 412   case dwarf::DW_FORM_GNU_str_index:
 413   case dwarf::DW_FORM_GNU_addr_index:
 414   case dwarf::DW_FORM_ref_udata:
 415   case dwarf::DW_FORM_strx:
 416   case dwarf::DW_FORM_addrx:
 417   case dwarf::DW_FORM_rnglistx:
 418   case dwarf::DW_FORM_udata:
 419     Asm->emitULEB128(Integer);
 420     return;
 421   case dwarf::DW_FORM_sdata:
 422     Asm->emitSLEB128(Integer);
 423     return;
 424   default: llvm_unreachable("DIE Value form not supported yet");
 425   }
 426 }
 427
 428 /// SizeOf - Determine size of integer value in bytes.
 429 ///
 430 unsigned DIEInteger::SizeOf(const AsmPrinter *AP, dwarf::Form Form) const {
 431   assert(AP && "AsmPrinter is required to set FormParams");
 432   dwarf::FormParams Params = {AP->getDwarfVersion(),
 433                               uint8_t(AP->getPointerSize()),
 434                               AP->OutStreamer->getContext().getDwarfFormat()};
 435
 436   if (Optional<uint8_t> FixedSize = dwarf::getFixedFormByteSize(Form, Params))
 437     return *FixedSize;
 438
 439   switch (Form) {
 440   case dwarf::DW_FORM_GNU_str_index:
 441   case dwarf::DW_FORM_GNU_addr_index:
 442   case dwarf::DW_FORM_ref_udata:
 443   case dwarf::DW_FORM_strx:
 444   case dwarf::DW_FORM_addrx:
 445   case dwarf::DW_FORM_rnglistx:
 446   case dwarf::DW_FORM_udata:
 447     return getULEB128Size(Integer);
 448   case dwarf::DW_FORM_sdata:
 449     return getSLEB128Size(Integer);
 450   default: llvm_unreachable("DIE Value form not supported yet");
 451   }
 452 }
 453
 454 LLVM_DUMP_METHOD
 455 void DIEInteger::print(raw_ostream &O) const {
 456   O << "Int: " << (int64_t)Integer << "  0x";
 457   O.write_hex(Integer);
 458 }
 459
 460 //===----------------------------------------------------------------------===//
 461 // DIEExpr Implementation
 462 //===----------------------------------------------------------------------===//
 463
 464 /// EmitValue - Emit expression value.
 465 ///
 466 void DIEExpr::emitValue(const AsmPrinter *AP, dwarf::Form Form) const {
 467   AP->emitDebugValue(Expr, SizeOf(AP, Form));
 468 }
 469
 470 /// SizeOf - Determine size of expression value in bytes.
 471 ///
 472 unsigned DIEExpr::SizeOf(const AsmPrinter *AP, dwarf::Form Form) const {
 473   switch (Form) {
 474   case dwarf::DW_FORM_data4:
 475     return 4;
 476   case dwarf::DW_FORM_data8:
 477     return 8;
 478   case dwarf::DW_FORM_sec_offset:
 479     return AP->getDwarfOffsetByteSize();
 480   default:
 481     llvm_unreachable("DIE Value form not supported yet");
 482   }
 483 }
 484
 485 LLVM_DUMP_METHOD
 486 void DIEExpr::print(raw_ostream &O) const { O << "Expr: " << *Expr; }
 487
 488 //===----------------------------------------------------------------------===//
 489 // DIELabel Implementation
 490 //===----------------------------------------------------------------------===//
 491
 492 /// EmitValue - Emit label value.
 493 ///
 494 void DIELabel::emitValue(const AsmPrinter *AP, dwarf::Form Form) const {
 495   bool IsSectionRelative = Form != dwarf::DW_FORM_addr;
 496   AP->emitLabelReference(Label, SizeOf(AP, Form), IsSectionRelative);
 497 }
 498
 499 /// SizeOf - Determine size of label value in bytes.
 500 ///
 501 unsigned DIELabel::SizeOf(const AsmPrinter *AP, dwarf::Form Form) const {
 502   switch (Form) {
 503   case dwarf::DW_FORM_data4:
 504     return 4;
 505   case dwarf::DW_FORM_data8:
 506     return 8;
 507   case dwarf::DW_FORM_sec_offset:
 508   case dwarf::DW_FORM_strp:
 509     return AP->getDwarfOffsetByteSize();
 510   case dwarf::DW_FORM_addr:
 511     return AP->MAI->getCodePointerSize();
 512   default:
 513     llvm_unreachable("DIE Value form not supported yet");
 514   }
 515 }
 516
 517 LLVM_DUMP_METHOD
 518 void DIELabel::print(raw_ostream &O) const { O << "Lbl: " << Label->getName(); }
 519
 520 //===----------------------------------------------------------------------===//
 521 // DIEBaseTypeRef Implementation
 522 //===----------------------------------------------------------------------===//
 523
 524 void DIEBaseTypeRef::emitValue(const AsmPrinter *AP, dwarf::Form Form) const {
 525   uint64_t Offset = CU->ExprRefedBaseTypes[Index].Die->getOffset();
 526   assert(Offset < (1ULL << (ULEB128PadSize * 7)) && "Offset wont fit");
 527   AP->emitULEB128(Offset, nullptr, ULEB128PadSize);
 528 }
 529
 530 unsigned DIEBaseTypeRef::SizeOf(const AsmPrinter *AP, dwarf::Form Form) const {
 531   return ULEB128PadSize;
 532 }
 533
 534 LLVM_DUMP_METHOD
 535 void DIEBaseTypeRef::print(raw_ostream &O) const { O << "BaseTypeRef: " << Index; }
 536
 537 //===----------------------------------------------------------------------===//
 538 // DIEDelta Implementation
 539 //===----------------------------------------------------------------------===//
 540
 541 /// EmitValue - Emit delta value.
 542 ///
 543 void DIEDelta::emitValue(const AsmPrinter *AP, dwarf::Form Form) const {
 544   AP->emitLabelDifference(LabelHi, LabelLo, SizeOf(AP, Form));
 545 }
 546
 547 /// SizeOf - Determine size of delta value in bytes.
 548 ///
 549 unsigned DIEDelta::SizeOf(const AsmPrinter *AP, dwarf::Form Form) const {
 550   switch (Form) {
 551   case dwarf::DW_FORM_data4:
 552     return 4;
 553   case dwarf::DW_FORM_data8:
 554     return 8;
 555   case dwarf::DW_FORM_sec_offset:
 556     return AP->getDwarfOffsetByteSize();
 557   default:
 558     llvm_unreachable("DIE Value form not supported yet");
 559   }
 560 }
 561
 562 LLVM_DUMP_METHOD
 563 void DIEDelta::print(raw_ostream &O) const {
 564   O << "Del: " << LabelHi->getName() << "-" << LabelLo->getName();
 565 }
 566
 567 //===----------------------------------------------------------------------===//
 568 // DIEString Implementation
 569 //===----------------------------------------------------------------------===//
 570
 571 /// EmitValue - Emit string value.
 572 ///
 573 void DIEString::emitValue(const AsmPrinter *AP, dwarf::Form Form) const {
 574   // Index of string in symbol table.
 575   switch (Form) {
 576   case dwarf::DW_FORM_GNU_str_index:
 577   case dwarf::DW_FORM_strx:
 578   case dwarf::DW_FORM_strx1:
 579   case dwarf::DW_FORM_strx2:
 580   case dwarf::DW_FORM_strx3:
 581   case dwarf::DW_FORM_strx4:
 582     DIEInteger(S.getIndex()).emitValue(AP, Form);
 583     return;
 584   case dwarf::DW_FORM_strp:
 585     if (AP->MAI->doesDwarfUseRelocationsAcrossSections())
 586       DIELabel(S.getSymbol()).emitValue(AP, Form);
 587     else
 588       DIEInteger(S.getOffset()).emitValue(AP, Form);
 589     return;
 590   default:
 591     llvm_unreachable("Expected valid string form");
 592   }
 593 }
 594
 595 /// SizeOf - Determine size of delta value in bytes.
 596 ///
 597 unsigned DIEString::SizeOf(const AsmPrinter *AP, dwarf::Form Form) const {
 598   // Index of string in symbol table.
 599   switch (Form) {
 600   case dwarf::DW_FORM_GNU_str_index:
 601   case dwarf::DW_FORM_strx:
 602   case dwarf::DW_FORM_strx1:
 603   case dwarf::DW_FORM_strx2:
 604   case dwarf::DW_FORM_strx3:
 605   case dwarf::DW_FORM_strx4:
 606     return DIEInteger(S.getIndex()).SizeOf(AP, Form);
 607   case dwarf::DW_FORM_strp:
 608     if (AP->MAI->doesDwarfUseRelocationsAcrossSections())
 609       return DIELabel(S.getSymbol()).SizeOf(AP, Form);
 610     return DIEInteger(S.getOffset()).SizeOf(AP, Form);
 611   default:
 612     llvm_unreachable("Expected valid string form");
 613   }
 614 }
 615
 616 LLVM_DUMP_METHOD
 617 void DIEString::print(raw_ostream &O) const {
 618   O << "String: " << S.getString();
 619 }
 620
 621 //===----------------------------------------------------------------------===//
 622 // DIEInlineString Implementation
 623 //===----------------------------------------------------------------------===//
 624 void DIEInlineString::emitValue(const AsmPrinter *AP, dwarf::Form Form) const {
 625   if (Form == dwarf::DW_FORM_string) {
 626     AP->OutStreamer->emitBytes(S);
 627     AP->emitInt8(0);
 628     return;
 629   }
 630   llvm_unreachable("Expected valid string form");
 631 }
 632
 633 unsigned DIEInlineString::SizeOf(const AsmPrinter *AP, dwarf::Form Form) const {
 634   // Emit string bytes + NULL byte.
 635   return S.size() + 1;
 636 }
 637
 638 LLVM_DUMP_METHOD
 639 void DIEInlineString::print(raw_ostream &O) const {
 640   O << "InlineString: " << S;
 641 }
 642
 643 //===----------------------------------------------------------------------===//
 644 // DIEEntry Implementation
 645 //===----------------------------------------------------------------------===//
 646
 647 /// EmitValue - Emit debug information entry offset.
 648 ///
 649 void DIEEntry::emitValue(const AsmPrinter *AP, dwarf::Form Form) const {
 650
 651   switch (Form) {
 652   case dwarf::DW_FORM_ref1:
 653   case dwarf::DW_FORM_ref2:
 654   case dwarf::DW_FORM_ref4:
 655   case dwarf::DW_FORM_ref8:
 656     AP->OutStreamer->emitIntValue(Entry->getOffset(), SizeOf(AP, Form));
 657     return;
 658
 659   case dwarf::DW_FORM_ref_udata:
 660     AP->emitULEB128(Entry->getOffset());
 661     return;
 662
 663   case dwarf::DW_FORM_ref_addr: {
 664     // Get the absolute offset for this DIE within the debug info/types section.
 665     uint64_t Addr = Entry->getDebugSectionOffset();
 666     if (const MCSymbol *SectionSym =
 667             Entry->getUnit()->getCrossSectionRelativeBaseAddress()) {
 668       AP->emitLabelPlusOffset(SectionSym, Addr, SizeOf(AP, Form), true);
 669       return;
 670     }
 671
 672     AP->OutStreamer->emitIntValue(Addr, SizeOf(AP, Form));
 673     return;
 674   }
 675   default:
 676     llvm_unreachable("Improper form for DIE reference");
 677   }
 678 }
 679
 680 unsigned DIEEntry::SizeOf(const AsmPrinter *AP, dwarf::Form Form) const {
 681   switch (Form) {
 682   case dwarf::DW_FORM_ref1:
 683     return 1;
 684   case dwarf::DW_FORM_ref2:
 685     return 2;
 686   case dwarf::DW_FORM_ref4:
 687     return 4;
 688   case dwarf::DW_FORM_ref8:
 689     return 8;
 690   case dwarf::DW_FORM_ref_udata:
 691     return getULEB128Size(Entry->getOffset());
 692   case dwarf::DW_FORM_ref_addr:
 693     if (AP->getDwarfVersion() == 2)
 694       return AP->MAI->getCodePointerSize();
 695     switch (AP->OutStreamer->getContext().getDwarfFormat()) {
 696     case dwarf::DWARF32:
 697       return 4;
 698     case dwarf::DWARF64:
 699       return 8;
 700     }
 701     llvm_unreachable("Invalid DWARF format");
 702
 703   default:
 704     llvm_unreachable("Improper form for DIE reference");
 705   }
 706 }
 707
 708 LLVM_DUMP_METHOD
 709 void DIEEntry::print(raw_ostream &O) const {
 710   O << format("Die: 0x%lx", (long)(intptr_t)&Entry);
 711 }
 712
 713 //===----------------------------------------------------------------------===//
 714 // DIELoc Implementation
 715 //===----------------------------------------------------------------------===//
 716
 717 /// ComputeSize - calculate the size of the location expression.
 718 ///
 719 unsigned DIELoc::ComputeSize(const AsmPrinter *AP) const {
 720   if (!Size) {
 721     for (const auto &V : values())
 722       Size += V.SizeOf(AP);
 723   }
 724
 725   return Size;
 726 }
 727
 728 /// EmitValue - Emit location data.
 729 ///
 730 void DIELoc::emitValue(const AsmPrinter *Asm, dwarf::Form Form) const {
 731   switch (Form) {
 732   default: llvm_unreachable("Improper form for block");
 733   case dwarf::DW_FORM_block1: Asm->emitInt8(Size);    break;
 734   case dwarf::DW_FORM_block2: Asm->emitInt16(Size);   break;
 735   case dwarf::DW_FORM_block4: Asm->emitInt32(Size);   break;
 736   case dwarf::DW_FORM_block:
 737   case dwarf::DW_FORM_exprloc:
 738     Asm->emitULEB128(Size);
 739     break;
 740   }
 741
 742   for (const auto &V : values())
 743     V.emitValue(Asm);
 744 }
 745
 746 /// SizeOf - Determine size of location data in bytes.
 747 ///
 748 unsigned DIELoc::SizeOf(const AsmPrinter *AP, dwarf::Form Form) const {
 749   switch (Form) {
 750   case dwarf::DW_FORM_block1: return Size + sizeof(int8_t);
 751   case dwarf::DW_FORM_block2: return Size + sizeof(int16_t);
 752   case dwarf::DW_FORM_block4: return Size + sizeof(int32_t);
 753   case dwarf::DW_FORM_block:
 754   case dwarf::DW_FORM_exprloc:
 755     return Size + getULEB128Size(Size);
 756   default: llvm_unreachable("Improper form for block");
 757   }
 758 }
 759
 760 LLVM_DUMP_METHOD
 761 void DIELoc::print(raw_ostream &O) const {
 762   printValues(O, *this, "ExprLoc", Size, 5);
 763 }
 764
 765 //===----------------------------------------------------------------------===//
 766 // DIEBlock Implementation
 767 //===----------------------------------------------------------------------===//
 768
 769 /// ComputeSize - calculate the size of the block.
 770 ///
 771 unsigned DIEBlock::ComputeSize(const AsmPrinter *AP) const {
 772   if (!Size) {
 773     for (const auto &V : values())
 774       Size += V.SizeOf(AP);
 775   }
 776
 777   return Size;
 778 }
 779
 780 /// EmitValue - Emit block data.
 781 ///
 782 void DIEBlock::emitValue(const AsmPrinter *Asm, dwarf::Form Form) const {
 783   switch (Form) {
 784   default: llvm_unreachable("Improper form for block");
 785   case dwarf::DW_FORM_block1: Asm->emitInt8(Size);    break;
 786   case dwarf::DW_FORM_block2: Asm->emitInt16(Size);   break;
 787   case dwarf::DW_FORM_block4: Asm->emitInt32(Size);   break;
 788   case dwarf::DW_FORM_exprloc:
 789   case dwarf::DW_FORM_block:
 790     Asm->emitULEB128(Size);
 791     break;
 792   case dwarf::DW_FORM_string: break;
 793   case dwarf::DW_FORM_data16: break;
 794   }
 795
 796   for (const auto &V : values())
 797     V.emitValue(Asm);
 798 }
 799
 800 /// SizeOf - Determine size of block data in bytes.
 801 ///
 802 unsigned DIEBlock::SizeOf(const AsmPrinter *AP, dwarf::Form Form) const {
 803   switch (Form) {
 804   case dwarf::DW_FORM_block1: return Size + sizeof(int8_t);
 805   case dwarf::DW_FORM_block2: return Size + sizeof(int16_t);
 806   case dwarf::DW_FORM_block4: return Size + sizeof(int32_t);
 807   case dwarf::DW_FORM_exprloc:
 808   case dwarf::DW_FORM_block:  return Size + getULEB128Size(Size);
 809   case dwarf::DW_FORM_data16: return 16;
 810   default: llvm_unreachable("Improper form for block");
 811   }
 812 }
 813
 814 LLVM_DUMP_METHOD
 815 void DIEBlock::print(raw_ostream &O) const {
 816   printValues(O, *this, "Blk", Size, 5);
 817 }
 818
 819 //===----------------------------------------------------------------------===//
 820 // DIELocList Implementation
 821 //===----------------------------------------------------------------------===//
 822
 823 unsigned DIELocList::SizeOf(const AsmPrinter *AP, dwarf::Form Form) const {
 824   switch (Form) {
 825   case dwarf::DW_FORM_loclistx:
 826     return getULEB128Size(Index);
 827   case dwarf::DW_FORM_data4:
 828     assert(!AP->isDwarf64() &&
 829            "DW_FORM_data4 is not suitable to emit a pointer to a location list "
 830            "in the 64-bit DWARF format");
 831     return 4;
 832   case dwarf::DW_FORM_data8:
 833     assert(AP->isDwarf64() &&
 834            "DW_FORM_data8 is not suitable to emit a pointer to a location list "
 835            "in the 32-bit DWARF format");
 836     return 8;
 837   case dwarf::DW_FORM_sec_offset:
 838     return AP->getDwarfOffsetByteSize();
 839   default:
 840     llvm_unreachable("DIE Value form not supported yet");
 841   }
 842 }
 843
 844 /// EmitValue - Emit label value.
 845 ///
 846 void DIELocList::emitValue(const AsmPrinter *AP, dwarf::Form Form) const {
 847   if (Form == dwarf::DW_FORM_loclistx) {
 848     AP->emitULEB128(Index);
 849     return;
 850   }
 851   DwarfDebug *DD = AP->getDwarfDebug();
 852   MCSymbol *Label = DD->getDebugLocs().getList(Index).Label;
 853   AP->emitDwarfSymbolReference(Label, /*ForceOffset*/ DD->useSplitDwarf());
 854 }
 855
 856 LLVM_DUMP_METHOD
 857 void DIELocList::print(raw_ostream &O) const { O << "LocList: " << Index; }
 858
 859 //===----------------------------------------------------------------------===//
 860 // DIEAddrOffset Implementation
 861 //===----------------------------------------------------------------------===//
 862
 863 unsigned DIEAddrOffset::SizeOf(const AsmPrinter *AP, dwarf::Form Form) const {
 864   return Addr.SizeOf(AP, dwarf::DW_FORM_addrx) +
 865          Offset.SizeOf(AP, dwarf::DW_FORM_data4);
 866 }
 867
 868 /// EmitValue - Emit label value.
 869 ///
 870 void DIEAddrOffset::emitValue(const AsmPrinter *AP, dwarf::Form Form) const {
 871   Addr.emitValue(AP, dwarf::DW_FORM_addrx);
 872   Offset.emitValue(AP, dwarf::DW_FORM_data4);
 873 }
 874
 875 LLVM_DUMP_METHOD
 876 void DIEAddrOffset::print(raw_ostream &O) const {
 877   O << "AddrOffset: ";
 878   Addr.print(O);
 879   O << " + ";
 880   Offset.print(O);
 881 }