DwarfDebug.cpp revision 208cc6f48975320da1a71cf7f7eff497f4f43b75 
1//===-- llvm/CodeGen/DwarfDebug.cpp - Dwarf Debug Framework ---------------===//
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// This file contains support for writing dwarf debug info into asm files.
11//
12//===----------------------------------------------------------------------===//
13
14#define DEBUG_TYPE "dwarfdebug"
15#include "DwarfDebug.h"
16#include "DIE.h"
17#include "DwarfAccelTable.h"
18#include "DwarfCompileUnit.h"
19#include "llvm/ADT/STLExtras.h"
20#include "llvm/ADT/Statistic.h"
21#include "llvm/ADT/StringExtras.h"
22#include "llvm/ADT/Triple.h"
23#include "llvm/CodeGen/MachineFunction.h"
24#include "llvm/CodeGen/MachineModuleInfo.h"
25#include "llvm/DIBuilder.h"
26#include "llvm/DebugInfo.h"
27#include "llvm/IR/Constants.h"
28#include "llvm/IR/DataLayout.h"
29#include "llvm/IR/Instructions.h"
30#include "llvm/IR/Module.h"
31#include "llvm/MC/MCAsmInfo.h"
32#include "llvm/MC/MCSection.h"
33#include "llvm/MC/MCStreamer.h"
34#include "llvm/MC/MCSymbol.h"
35#include "llvm/Support/CommandLine.h"
36#include "llvm/Support/Debug.h"
37#include "llvm/Support/ErrorHandling.h"
38#include "llvm/Support/FormattedStream.h"
39#include "llvm/Support/Path.h"
40#include "llvm/Support/Timer.h"
41#include "llvm/Support/ValueHandle.h"
42#include "llvm/Target/TargetFrameLowering.h"
43#include "llvm/Target/TargetLoweringObjectFile.h"
44#include "llvm/Target/TargetMachine.h"
45#include "llvm/Target/TargetOptions.h"
46#include "llvm/Target/TargetRegisterInfo.h"
47using namespace llvm;
48
49static cl::opt<bool> DisableDebugInfoPrinting("disable-debug-info-print",
50                                              cl::Hidden,
51     cl::desc("Disable debug info printing"));
52
53static cl::opt<bool> UnknownLocations("use-unknown-locations", cl::Hidden,
54     cl::desc("Make an absence of debug location information explicit."),
55     cl::init(false));
56
57namespace {
58  enum DefaultOnOff {
59    Default, Enable, Disable
60  };
61}
62
63static cl::opt<DefaultOnOff> DwarfAccelTables("dwarf-accel-tables", cl::Hidden,
64     cl::desc("Output prototype dwarf accelerator tables."),
65     cl::values(
66                clEnumVal(Default, "Default for platform"),
67                clEnumVal(Enable, "Enabled"),
68                clEnumVal(Disable, "Disabled"),
69                clEnumValEnd),
70     cl::init(Default));
71
72static cl::opt<DefaultOnOff> DarwinGDBCompat("darwin-gdb-compat", cl::Hidden,
73     cl::desc("Compatibility with Darwin gdb."),
74     cl::values(
75                clEnumVal(Default, "Default for platform"),
76                clEnumVal(Enable, "Enabled"),
77                clEnumVal(Disable, "Disabled"),
78                clEnumValEnd),
79     cl::init(Default));
80
81static cl::opt<DefaultOnOff> SplitDwarf("split-dwarf", cl::Hidden,
82     cl::desc("Output prototype dwarf split debug info."),
83     cl::values(
84                clEnumVal(Default, "Default for platform"),
85                clEnumVal(Enable, "Enabled"),
86                clEnumVal(Disable, "Disabled"),
87                clEnumValEnd),
88     cl::init(Default));
89
90namespace {
91  const char *DWARFGroupName = "DWARF Emission";
92  const char *DbgTimerName = "DWARF Debug Writer";
93} // end anonymous namespace
94
95//===----------------------------------------------------------------------===//
96
97// Configuration values for initial hash set sizes (log2).
98//
99static const unsigned InitAbbreviationsSetSize = 9; // log2(512)
100
101namespace llvm {
102
103DIType DbgVariable::getType() const {
104  DIType Ty = Var.getType();
105  // FIXME: isBlockByrefVariable should be reformulated in terms of complex
106  // addresses instead.
107  if (Var.isBlockByrefVariable()) {
108    /* Byref variables, in Blocks, are declared by the programmer as
109       "SomeType VarName;", but the compiler creates a
110       __Block_byref_x_VarName struct, and gives the variable VarName
111       either the struct, or a pointer to the struct, as its type.  This
112       is necessary for various behind-the-scenes things the compiler
113       needs to do with by-reference variables in blocks.
114
115       However, as far as the original *programmer* is concerned, the
116       variable should still have type 'SomeType', as originally declared.
117
118       The following function dives into the __Block_byref_x_VarName
119       struct to find the original type of the variable.  This will be
120       passed back to the code generating the type for the Debug
121       Information Entry for the variable 'VarName'.  'VarName' will then
122       have the original type 'SomeType' in its debug information.
123
124       The original type 'SomeType' will be the type of the field named
125       'VarName' inside the __Block_byref_x_VarName struct.
126
127       NOTE: In order for this to not completely fail on the debugger
128       side, the Debug Information Entry for the variable VarName needs to
129       have a DW_AT_location that tells the debugger how to unwind through
130       the pointers and __Block_byref_x_VarName struct to find the actual
131       value of the variable.  The function addBlockByrefType does this.  */
132    DIType subType = Ty;
133    unsigned tag = Ty.getTag();
134
135    if (tag == dwarf::DW_TAG_pointer_type) {
136      DIDerivedType DTy = DIDerivedType(Ty);
137      subType = DTy.getTypeDerivedFrom();
138    }
139
140    DICompositeType blockStruct = DICompositeType(subType);
141    DIArray Elements = blockStruct.getTypeArray();
142
143    for (unsigned i = 0, N = Elements.getNumElements(); i < N; ++i) {
144      DIDescriptor Element = Elements.getElement(i);
145      DIDerivedType DT = DIDerivedType(Element);
146      if (getName() == DT.getName())
147        return (DT.getTypeDerivedFrom());
148    }
149  }
150  return Ty;
151}
152
153} // end llvm namespace
154
155DwarfDebug::DwarfDebug(AsmPrinter *A, Module *M)
156  : Asm(A), MMI(Asm->MMI), FirstCU(0),
157    AbbreviationsSet(InitAbbreviationsSetSize),
158    SourceIdMap(DIEValueAllocator),
159    PrevLabel(NULL), GlobalCUIndexCount(0),
160    InfoHolder(A, &AbbreviationsSet, &Abbreviations, "info_string",
161               DIEValueAllocator),
162    SkeletonCU(0),
163    SkeletonAbbrevSet(InitAbbreviationsSetSize),
164    SkeletonHolder(A, &SkeletonAbbrevSet, &SkeletonAbbrevs, "skel_string",
165                   DIEValueAllocator) {
166
167  DwarfInfoSectionSym = DwarfAbbrevSectionSym = 0;
168  DwarfStrSectionSym = TextSectionSym = 0;
169  DwarfDebugRangeSectionSym = DwarfDebugLocSectionSym = 0;
170  DwarfAbbrevDWOSectionSym = DwarfStrDWOSectionSym = 0;
171  FunctionBeginSym = FunctionEndSym = 0;
172
173  // Turn on accelerator tables and older gdb compatibility
174  // for Darwin.
175  bool IsDarwin = Triple(M->getTargetTriple()).isOSDarwin();
176  if (DarwinGDBCompat == Default) {
177    if (IsDarwin)
178      IsDarwinGDBCompat = true;
179    else
180      IsDarwinGDBCompat = false;
181  } else
182    IsDarwinGDBCompat = DarwinGDBCompat == Enable ? true : false;
183
184  if (DwarfAccelTables == Default) {
185    if (IsDarwin)
186      HasDwarfAccelTables = true;
187    else
188      HasDwarfAccelTables = false;
189  } else
190    HasDwarfAccelTables = DwarfAccelTables == Enable ? true : false;
191
192  if (SplitDwarf == Default)
193    HasSplitDwarf = false;
194  else
195    HasSplitDwarf = SplitDwarf == Enable ? true : false;
196
197  {
198    NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
199    beginModule();
200  }
201}
202DwarfDebug::~DwarfDebug() {
203}
204
205// Switch to the specified MCSection and emit an assembler
206// temporary label to it if SymbolStem is specified.
207static MCSymbol *emitSectionSym(AsmPrinter *Asm, const MCSection *Section,
208                                const char *SymbolStem = 0) {
209  Asm->OutStreamer.SwitchSection(Section);
210  if (!SymbolStem) return 0;
211
212  MCSymbol *TmpSym = Asm->GetTempSymbol(SymbolStem);
213  Asm->OutStreamer.EmitLabel(TmpSym);
214  return TmpSym;
215}
216
217MCSymbol *DwarfUnits::getStringPoolSym() {
218  return Asm->GetTempSymbol(StringPref);
219}
220
221MCSymbol *DwarfUnits::getStringPoolEntry(StringRef Str) {
222  std::pair<MCSymbol*, unsigned> &Entry =
223    StringPool.GetOrCreateValue(Str).getValue();
224  if (Entry.first) return Entry.first;
225
226  Entry.second = NextStringPoolNumber++;
227  return Entry.first = Asm->GetTempSymbol(StringPref, Entry.second);
228}
229
230unsigned DwarfUnits::getStringPoolIndex(StringRef Str) {
231  std::pair<MCSymbol*, unsigned> &Entry =
232    StringPool.GetOrCreateValue(Str).getValue();
233  if (Entry.first) return Entry.second;
234
235  Entry.second = NextStringPoolNumber++;
236  Entry.first = Asm->GetTempSymbol(StringPref, Entry.second);
237  return Entry.second;
238}
239
240unsigned DwarfUnits::getAddrPoolIndex(MCSymbol *Sym) {
241  std::pair<MCSymbol*, unsigned> &Entry = AddressPool[Sym];
242  if (Entry.first) return Entry.second;
243
244  Entry.second = NextAddrPoolNumber++;
245  Entry.first = Sym;
246  return Entry.second;
247}
248
249// Define a unique number for the abbreviation.
250//
251void DwarfUnits::assignAbbrevNumber(DIEAbbrev &Abbrev) {
252  // Profile the node so that we can make it unique.
253  FoldingSetNodeID ID;
254  Abbrev.Profile(ID);
255
256  // Check the set for priors.
257  DIEAbbrev *InSet = AbbreviationsSet->GetOrInsertNode(&Abbrev);
258
259  // If it's newly added.
260  if (InSet == &Abbrev) {
261    // Add to abbreviation list.
262    Abbreviations->push_back(&Abbrev);
263
264    // Assign the vector position + 1 as its number.
265    Abbrev.setNumber(Abbreviations->size());
266  } else {
267    // Assign existing abbreviation number.
268    Abbrev.setNumber(InSet->getNumber());
269  }
270}
271
272// If special LLVM prefix that is used to inform the asm
273// printer to not emit usual symbol prefix before the symbol name is used then
274// return linkage name after skipping this special LLVM prefix.
275static StringRef getRealLinkageName(StringRef LinkageName) {
276  char One = '\1';
277  if (LinkageName.startswith(StringRef(&One, 1)))
278    return LinkageName.substr(1);
279  return LinkageName;
280}
281
282static bool isObjCClass(StringRef Name) {
283  return Name.startswith("+") || Name.startswith("-");
284}
285
286static bool hasObjCCategory(StringRef Name) {
287  if (!isObjCClass(Name)) return false;
288
289  size_t pos = Name.find(')');
290  if (pos != std::string::npos) {
291    if (Name[pos+1] != ' ') return false;
292    return true;
293  }
294  return false;
295}
296
297static void getObjCClassCategory(StringRef In, StringRef &Class,
298                                 StringRef &Category) {
299  if (!hasObjCCategory(In)) {
300    Class = In.slice(In.find('[') + 1, In.find(' '));
301    Category = "";
302    return;
303  }
304
305  Class = In.slice(In.find('[') + 1, In.find('('));
306  Category = In.slice(In.find('[') + 1, In.find(' '));
307  return;
308}
309
310static StringRef getObjCMethodName(StringRef In) {
311  return In.slice(In.find(' ') + 1, In.find(']'));
312}
313
314// Add the various names to the Dwarf accelerator table names.
315static void addSubprogramNames(CompileUnit *TheCU, DISubprogram SP,
316                               DIE* Die) {
317  if (!SP.isDefinition()) return;
318
319  TheCU->addAccelName(SP.getName(), Die);
320
321  // If the linkage name is different than the name, go ahead and output
322  // that as well into the name table.
323  if (SP.getLinkageName() != "" && SP.getName() != SP.getLinkageName())
324    TheCU->addAccelName(SP.getLinkageName(), Die);
325
326  // If this is an Objective-C selector name add it to the ObjC accelerator
327  // too.
328  if (isObjCClass(SP.getName())) {
329    StringRef Class, Category;
330    getObjCClassCategory(SP.getName(), Class, Category);
331    TheCU->addAccelObjC(Class, Die);
332    if (Category != "")
333      TheCU->addAccelObjC(Category, Die);
334    // Also add the base method name to the name table.
335    TheCU->addAccelName(getObjCMethodName(SP.getName()), Die);
336  }
337}
338
339// Find DIE for the given subprogram and attach appropriate DW_AT_low_pc
340// and DW_AT_high_pc attributes. If there are global variables in this
341// scope then create and insert DIEs for these variables.
342DIE *DwarfDebug::updateSubprogramScopeDIE(CompileUnit *SPCU,
343                                          const MDNode *SPNode) {
344  DIE *SPDie = SPCU->getDIE(SPNode);
345
346  assert(SPDie && "Unable to find subprogram DIE!");
347  DISubprogram SP(SPNode);
348
349  // If we're updating an abstract DIE, then we will be adding the children and
350  // object pointer later on. But what we don't want to do is process the
351  // concrete DIE twice.
352  if (DIE *AbsSPDIE = AbstractSPDies.lookup(SPNode)) {
353    // Pick up abstract subprogram DIE.
354    SPDie = new DIE(dwarf::DW_TAG_subprogram);
355    SPCU->addDIEEntry(SPDie, dwarf::DW_AT_abstract_origin,
356                      dwarf::DW_FORM_ref4, AbsSPDIE);
357    SPCU->addDie(SPDie);
358  } else {
359    DISubprogram SPDecl = SP.getFunctionDeclaration();
360    if (!SPDecl.isSubprogram()) {
361      // There is not any need to generate specification DIE for a function
362      // defined at compile unit level. If a function is defined inside another
363      // function then gdb prefers the definition at top level and but does not
364      // expect specification DIE in parent function. So avoid creating
365      // specification DIE for a function defined inside a function.
366      if (SP.isDefinition() && !SP.getContext().isCompileUnit() &&
367          !SP.getContext().isFile() &&
368          !isSubprogramContext(SP.getContext())) {
369        SPCU->addFlag(SPDie, dwarf::DW_AT_declaration);
370
371        // Add arguments.
372        DICompositeType SPTy = SP.getType();
373        DIArray Args = SPTy.getTypeArray();
374        unsigned SPTag = SPTy.getTag();
375        if (SPTag == dwarf::DW_TAG_subroutine_type)
376          for (unsigned i = 1, N = Args.getNumElements(); i < N; ++i) {
377            DIE *Arg = new DIE(dwarf::DW_TAG_formal_parameter);
378            DIType ATy = DIType(Args.getElement(i));
379            SPCU->addType(Arg, ATy);
380            if (ATy.isArtificial())
381              SPCU->addFlag(Arg, dwarf::DW_AT_artificial);
382            if (ATy.isObjectPointer())
383              SPCU->addDIEEntry(SPDie, dwarf::DW_AT_object_pointer,
384                                dwarf::DW_FORM_ref4, Arg);
385            SPDie->addChild(Arg);
386          }
387        DIE *SPDeclDie = SPDie;
388        SPDie = new DIE(dwarf::DW_TAG_subprogram);
389        SPCU->addDIEEntry(SPDie, dwarf::DW_AT_specification,
390                          dwarf::DW_FORM_ref4, SPDeclDie);
391        SPCU->addDie(SPDie);
392      }
393    }
394  }
395
396  SPCU->addLabelAddress(SPDie, dwarf::DW_AT_low_pc,
397                        Asm->GetTempSymbol("func_begin",
398                                           Asm->getFunctionNumber()));
399  SPCU->addLabelAddress(SPDie, dwarf::DW_AT_high_pc,
400                        Asm->GetTempSymbol("func_end",
401                                           Asm->getFunctionNumber()));
402  const TargetRegisterInfo *RI = Asm->TM.getRegisterInfo();
403  MachineLocation Location(RI->getFrameRegister(*Asm->MF));
404  SPCU->addAddress(SPDie, dwarf::DW_AT_frame_base, Location);
405
406  // Add name to the name table, we do this here because we're guaranteed
407  // to have concrete versions of our DW_TAG_subprogram nodes.
408  addSubprogramNames(SPCU, SP, SPDie);
409
410  return SPDie;
411}
412
413// Construct new DW_TAG_lexical_block for this scope and attach
414// DW_AT_low_pc/DW_AT_high_pc labels.
415DIE *DwarfDebug::constructLexicalScopeDIE(CompileUnit *TheCU,
416                                          LexicalScope *Scope) {
417  DIE *ScopeDIE = new DIE(dwarf::DW_TAG_lexical_block);
418  if (Scope->isAbstractScope())
419    return ScopeDIE;
420
421  const SmallVector<InsnRange, 4> &Ranges = Scope->getRanges();
422  if (Ranges.empty())
423    return 0;
424
425  SmallVector<InsnRange, 4>::const_iterator RI = Ranges.begin();
426  if (Ranges.size() > 1) {
427    // .debug_range section has not been laid out yet. Emit offset in
428    // .debug_range as a uint, size 4, for now. emitDIE will handle
429    // DW_AT_ranges appropriately.
430    TheCU->addUInt(ScopeDIE, dwarf::DW_AT_ranges, dwarf::DW_FORM_data4,
431                   DebugRangeSymbols.size()
432                   * Asm->getDataLayout().getPointerSize());
433    for (SmallVector<InsnRange, 4>::const_iterator RI = Ranges.begin(),
434         RE = Ranges.end(); RI != RE; ++RI) {
435      DebugRangeSymbols.push_back(getLabelBeforeInsn(RI->first));
436      DebugRangeSymbols.push_back(getLabelAfterInsn(RI->second));
437    }
438    DebugRangeSymbols.push_back(NULL);
439    DebugRangeSymbols.push_back(NULL);
440    return ScopeDIE;
441  }
442
443  MCSymbol *Start = getLabelBeforeInsn(RI->first);
444  MCSymbol *End = getLabelAfterInsn(RI->second);
445
446  if (End == 0) return 0;
447
448  assert(Start->isDefined() && "Invalid starting label for an inlined scope!");
449  assert(End->isDefined() && "Invalid end label for an inlined scope!");
450
451  TheCU->addLabelAddress(ScopeDIE, dwarf::DW_AT_low_pc, Start);
452  TheCU->addLabelAddress(ScopeDIE, dwarf::DW_AT_high_pc, End);
453
454  return ScopeDIE;
455}
456
457// This scope represents inlined body of a function. Construct DIE to
458// represent this concrete inlined copy of the function.
459DIE *DwarfDebug::constructInlinedScopeDIE(CompileUnit *TheCU,
460                                          LexicalScope *Scope) {
461  const SmallVector<InsnRange, 4> &Ranges = Scope->getRanges();
462  assert(Ranges.empty() == false &&
463         "LexicalScope does not have instruction markers!");
464
465  if (!Scope->getScopeNode())
466    return NULL;
467  DIScope DS(Scope->getScopeNode());
468  DISubprogram InlinedSP = getDISubprogram(DS);
469  DIE *OriginDIE = TheCU->getDIE(InlinedSP);
470  if (!OriginDIE) {
471    DEBUG(dbgs() << "Unable to find original DIE for an inlined subprogram.");
472    return NULL;
473  }
474
475  SmallVector<InsnRange, 4>::const_iterator RI = Ranges.begin();
476  MCSymbol *StartLabel = getLabelBeforeInsn(RI->first);
477  MCSymbol *EndLabel = getLabelAfterInsn(RI->second);
478
479  if (StartLabel == 0 || EndLabel == 0) {
480    llvm_unreachable("Unexpected Start and End labels for an inlined scope!");
481  }
482  assert(StartLabel->isDefined() &&
483         "Invalid starting label for an inlined scope!");
484  assert(EndLabel->isDefined() &&
485         "Invalid end label for an inlined scope!");
486
487  DIE *ScopeDIE = new DIE(dwarf::DW_TAG_inlined_subroutine);
488  TheCU->addDIEEntry(ScopeDIE, dwarf::DW_AT_abstract_origin,
489                     dwarf::DW_FORM_ref4, OriginDIE);
490
491  if (Ranges.size() > 1) {
492    // .debug_range section has not been laid out yet. Emit offset in
493    // .debug_range as a uint, size 4, for now. emitDIE will handle
494    // DW_AT_ranges appropriately.
495    TheCU->addUInt(ScopeDIE, dwarf::DW_AT_ranges, dwarf::DW_FORM_data4,
496                   DebugRangeSymbols.size()
497                   * Asm->getDataLayout().getPointerSize());
498    for (SmallVector<InsnRange, 4>::const_iterator RI = Ranges.begin(),
499         RE = Ranges.end(); RI != RE; ++RI) {
500      DebugRangeSymbols.push_back(getLabelBeforeInsn(RI->first));
501      DebugRangeSymbols.push_back(getLabelAfterInsn(RI->second));
502    }
503    DebugRangeSymbols.push_back(NULL);
504    DebugRangeSymbols.push_back(NULL);
505  } else {
506    TheCU->addLabelAddress(ScopeDIE, dwarf::DW_AT_low_pc, StartLabel);
507    TheCU->addLabelAddress(ScopeDIE, dwarf::DW_AT_high_pc, EndLabel);
508  }
509
510  InlinedSubprogramDIEs.insert(OriginDIE);
511
512  // Track the start label for this inlined function.
513  //.debug_inlined section specification does not clearly state how
514  // to emit inlined scope that is split into multiple instruction ranges.
515  // For now, use first instruction range and emit low_pc/high_pc pair and
516  // corresponding .debug_inlined section entry for this pair.
517  DenseMap<const MDNode *, SmallVector<InlineInfoLabels, 4> >::iterator
518    I = InlineInfo.find(InlinedSP);
519
520  if (I == InlineInfo.end()) {
521    InlineInfo[InlinedSP].push_back(std::make_pair(StartLabel, ScopeDIE));
522    InlinedSPNodes.push_back(InlinedSP);
523  } else
524    I->second.push_back(std::make_pair(StartLabel, ScopeDIE));
525
526  DILocation DL(Scope->getInlinedAt());
527  TheCU->addUInt(ScopeDIE, dwarf::DW_AT_call_file, 0,
528                 getOrCreateSourceID(DL.getFilename(), DL.getDirectory()));
529  TheCU->addUInt(ScopeDIE, dwarf::DW_AT_call_line, 0, DL.getLineNumber());
530
531  // Add name to the name table, we do this here because we're guaranteed
532  // to have concrete versions of our DW_TAG_inlined_subprogram nodes.
533  addSubprogramNames(TheCU, InlinedSP, ScopeDIE);
534
535  return ScopeDIE;
536}
537
538// Construct a DIE for this scope.
539DIE *DwarfDebug::constructScopeDIE(CompileUnit *TheCU, LexicalScope *Scope) {
540  if (!Scope || !Scope->getScopeNode())
541    return NULL;
542
543  DIScope DS(Scope->getScopeNode());
544  // Early return to avoid creating dangling variable|scope DIEs.
545  if (!Scope->getInlinedAt() && DS.isSubprogram() && Scope->isAbstractScope() &&
546      !TheCU->getDIE(DS))
547    return NULL;
548
549  SmallVector<DIE *, 8> Children;
550  DIE *ObjectPointer = NULL;
551
552  // Collect arguments for current function.
553  if (LScopes.isCurrentFunctionScope(Scope))
554    for (unsigned i = 0, N = CurrentFnArguments.size(); i < N; ++i)
555      if (DbgVariable *ArgDV = CurrentFnArguments[i])
556        if (DIE *Arg =
557            TheCU->constructVariableDIE(ArgDV, Scope->isAbstractScope())) {
558          Children.push_back(Arg);
559          if (ArgDV->isObjectPointer()) ObjectPointer = Arg;
560        }
561
562  // Collect lexical scope children first.
563  const SmallVector<DbgVariable *, 8> &Variables = ScopeVariables.lookup(Scope);
564  for (unsigned i = 0, N = Variables.size(); i < N; ++i)
565    if (DIE *Variable =
566        TheCU->constructVariableDIE(Variables[i], Scope->isAbstractScope())) {
567      Children.push_back(Variable);
568      if (Variables[i]->isObjectPointer()) ObjectPointer = Variable;
569    }
570  const SmallVector<LexicalScope *, 4> &Scopes = Scope->getChildren();
571  for (unsigned j = 0, M = Scopes.size(); j < M; ++j)
572    if (DIE *Nested = constructScopeDIE(TheCU, Scopes[j]))
573      Children.push_back(Nested);
574  DIE *ScopeDIE = NULL;
575  if (Scope->getInlinedAt())
576    ScopeDIE = constructInlinedScopeDIE(TheCU, Scope);
577  else if (DS.isSubprogram()) {
578    ProcessedSPNodes.insert(DS);
579    if (Scope->isAbstractScope()) {
580      ScopeDIE = TheCU->getDIE(DS);
581      // Note down abstract DIE.
582      if (ScopeDIE)
583        AbstractSPDies.insert(std::make_pair(DS, ScopeDIE));
584    }
585    else
586      ScopeDIE = updateSubprogramScopeDIE(TheCU, DS);
587  }
588  else {
589    // There is no need to emit empty lexical block DIE.
590    if (Children.empty())
591      return NULL;
592    ScopeDIE = constructLexicalScopeDIE(TheCU, Scope);
593  }
594
595  if (!ScopeDIE) return NULL;
596
597  // Add children
598  for (SmallVector<DIE *, 8>::iterator I = Children.begin(),
599         E = Children.end(); I != E; ++I)
600    ScopeDIE->addChild(*I);
601
602  if (DS.isSubprogram() && ObjectPointer != NULL)
603    TheCU->addDIEEntry(ScopeDIE, dwarf::DW_AT_object_pointer,
604                       dwarf::DW_FORM_ref4, ObjectPointer);
605
606  if (DS.isSubprogram())
607    TheCU->addPubTypes(DISubprogram(DS));
608
609  return ScopeDIE;
610}
611
612// Look up the source id with the given directory and source file names.
613// If none currently exists, create a new id and insert it in the
614// SourceIds map. This can update DirectoryNames and SourceFileNames maps
615// as well.
616unsigned DwarfDebug::getOrCreateSourceID(StringRef FileName,
617                                         StringRef DirName) {
618  // If FE did not provide a file name, then assume stdin.
619  if (FileName.empty())
620    return getOrCreateSourceID("<stdin>", StringRef());
621
622  // TODO: this might not belong here. See if we can factor this better.
623  if (DirName == CompilationDir)
624    DirName = "";
625
626  unsigned SrcId = SourceIdMap.size()+1;
627
628  // We look up the file/dir pair by concatenating them with a zero byte.
629  SmallString<128> NamePair;
630  NamePair += DirName;
631  NamePair += '\0'; // Zero bytes are not allowed in paths.
632  NamePair += FileName;
633
634  StringMapEntry<unsigned> &Ent = SourceIdMap.GetOrCreateValue(NamePair, SrcId);
635  if (Ent.getValue() != SrcId)
636    return Ent.getValue();
637
638  // Print out a .file directive to specify files for .loc directives.
639  Asm->OutStreamer.EmitDwarfFileDirective(SrcId, DirName, FileName);
640
641  return SrcId;
642}
643
644// Create new CompileUnit for the given metadata node with tag
645// DW_TAG_compile_unit.
646CompileUnit *DwarfDebug::constructCompileUnit(const MDNode *N) {
647  DICompileUnit DIUnit(N);
648  StringRef FN = DIUnit.getFilename();
649  CompilationDir = DIUnit.getDirectory();
650  // Call this to emit a .file directive if it wasn't emitted for the source
651  // file this CU comes from yet.
652  getOrCreateSourceID(FN, CompilationDir);
653
654  DIE *Die = new DIE(dwarf::DW_TAG_compile_unit);
655  CompileUnit *NewCU = new CompileUnit(GlobalCUIndexCount++,
656                                       DIUnit.getLanguage(), Die, Asm,
657                                       this, &InfoHolder);
658  NewCU->addString(Die, dwarf::DW_AT_producer, DIUnit.getProducer());
659  NewCU->addUInt(Die, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
660                 DIUnit.getLanguage());
661  NewCU->addString(Die, dwarf::DW_AT_name, FN);
662  // 2.17.1 requires that we use DW_AT_low_pc for a single entry point
663  // into an entity. We're using 0 (or a NULL label) for this.
664  NewCU->addLabelAddress(Die, dwarf::DW_AT_low_pc, NULL);
665  // DW_AT_stmt_list is a offset of line number information for this
666  // compile unit in debug_line section.
667  if (Asm->MAI->doesDwarfUseRelocationsAcrossSections())
668    NewCU->addLabel(Die, dwarf::DW_AT_stmt_list, dwarf::DW_FORM_data4,
669                    Asm->GetTempSymbol("section_line"));
670  else
671    NewCU->addUInt(Die, dwarf::DW_AT_stmt_list, dwarf::DW_FORM_data4, 0);
672
673  if (!CompilationDir.empty())
674    NewCU->addString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
675  if (DIUnit.isOptimized())
676    NewCU->addFlag(Die, dwarf::DW_AT_APPLE_optimized);
677
678  StringRef Flags = DIUnit.getFlags();
679  if (!Flags.empty())
680    NewCU->addString(Die, dwarf::DW_AT_APPLE_flags, Flags);
681
682  if (unsigned RVer = DIUnit.getRunTimeVersion())
683    NewCU->addUInt(Die, dwarf::DW_AT_APPLE_major_runtime_vers,
684            dwarf::DW_FORM_data1, RVer);
685
686  if (!FirstCU)
687    FirstCU = NewCU;
688
689  // This should be a unique identifier when we want to build .dwp files.
690  if (useSplitDwarf())
691    NewCU->addUInt(Die, dwarf::DW_AT_GNU_dwo_id, dwarf::DW_FORM_data8, 0);
692
693  if (useSplitDwarf() && !SkeletonCU)
694    SkeletonCU = constructSkeletonCU(N);
695
696  InfoHolder.addUnit(NewCU);
697
698  CUMap.insert(std::make_pair(N, NewCU));
699  return NewCU;
700}
701
702// Construct subprogram DIE.
703void DwarfDebug::constructSubprogramDIE(CompileUnit *TheCU,
704                                        const MDNode *N) {
705  CompileUnit *&CURef = SPMap[N];
706  if (CURef)
707    return;
708  CURef = TheCU;
709
710  DISubprogram SP(N);
711  if (!SP.isDefinition())
712    // This is a method declaration which will be handled while constructing
713    // class type.
714    return;
715
716  DIE *SubprogramDie = TheCU->getOrCreateSubprogramDIE(SP);
717
718  // Add to map.
719  TheCU->insertDIE(N, SubprogramDie);
720
721  // Add to context owner.
722  TheCU->addToContextOwner(SubprogramDie, SP.getContext());
723
724  return;
725}
726
727// Collect debug info from named mdnodes such as llvm.dbg.enum and llvm.dbg.ty.
728void DwarfDebug::collectInfoFromNamedMDNodes(const Module *M) {
729  if (NamedMDNode *NMD = M->getNamedMetadata("llvm.dbg.sp"))
730    for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i) {
731      const MDNode *N = NMD->getOperand(i);
732      if (CompileUnit *CU = CUMap.lookup(DISubprogram(N).getCompileUnit()))
733        constructSubprogramDIE(CU, N);
734    }
735
736  if (NamedMDNode *NMD = M->getNamedMetadata("llvm.dbg.gv"))
737    for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i) {
738      const MDNode *N = NMD->getOperand(i);
739      if (CompileUnit *CU = CUMap.lookup(DIGlobalVariable(N).getCompileUnit()))
740        CU->createGlobalVariableDIE(N);
741    }
742
743  if (NamedMDNode *NMD = M->getNamedMetadata("llvm.dbg.enum"))
744    for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i) {
745      DIType Ty(NMD->getOperand(i));
746      if (CompileUnit *CU = CUMap.lookup(Ty.getCompileUnit()))
747        CU->getOrCreateTypeDIE(Ty);
748    }
749
750  if (NamedMDNode *NMD = M->getNamedMetadata("llvm.dbg.ty"))
751    for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i) {
752      DIType Ty(NMD->getOperand(i));
753      if (CompileUnit *CU = CUMap.lookup(Ty.getCompileUnit()))
754        CU->getOrCreateTypeDIE(Ty);
755    }
756}
757
758// Collect debug info using DebugInfoFinder.
759// FIXME - Remove this when dragonegg switches to DIBuilder.
760bool DwarfDebug::collectLegacyDebugInfo(const Module *M) {
761  DebugInfoFinder DbgFinder;
762  DbgFinder.processModule(*M);
763
764  bool HasDebugInfo = false;
765  // Scan all the compile-units to see if there are any marked as the main
766  // unit. If not, we do not generate debug info.
767  for (DebugInfoFinder::iterator I = DbgFinder.compile_unit_begin(),
768         E = DbgFinder.compile_unit_end(); I != E; ++I) {
769    if (DICompileUnit(*I).isMain()) {
770      HasDebugInfo = true;
771      break;
772    }
773  }
774  if (!HasDebugInfo) return false;
775
776  // Create all the compile unit DIEs.
777  for (DebugInfoFinder::iterator I = DbgFinder.compile_unit_begin(),
778         E = DbgFinder.compile_unit_end(); I != E; ++I)
779    constructCompileUnit(*I);
780
781  // Create DIEs for each global variable.
782  for (DebugInfoFinder::iterator I = DbgFinder.global_variable_begin(),
783         E = DbgFinder.global_variable_end(); I != E; ++I) {
784    const MDNode *N = *I;
785    if (CompileUnit *CU = CUMap.lookup(DIGlobalVariable(N).getCompileUnit()))
786      CU->createGlobalVariableDIE(N);
787  }
788
789  // Create DIEs for each subprogram.
790  for (DebugInfoFinder::iterator I = DbgFinder.subprogram_begin(),
791         E = DbgFinder.subprogram_end(); I != E; ++I) {
792    const MDNode *N = *I;
793    if (CompileUnit *CU = CUMap.lookup(DISubprogram(N).getCompileUnit()))
794      constructSubprogramDIE(CU, N);
795  }
796
797  return HasDebugInfo;
798}
799
800// Emit all Dwarf sections that should come prior to the content. Create
801// global DIEs and emit initial debug info sections. This is invoked by
802// the target AsmPrinter.
803void DwarfDebug::beginModule() {
804  if (DisableDebugInfoPrinting)
805    return;
806
807  const Module *M = MMI->getModule();
808
809  // If module has named metadata anchors then use them, otherwise scan the
810  // module using debug info finder to collect debug info.
811  NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
812  if (CU_Nodes) {
813    for (unsigned i = 0, e = CU_Nodes->getNumOperands(); i != e; ++i) {
814      DICompileUnit CUNode(CU_Nodes->getOperand(i));
815      CompileUnit *CU = constructCompileUnit(CUNode);
816      DIArray GVs = CUNode.getGlobalVariables();
817      for (unsigned i = 0, e = GVs.getNumElements(); i != e; ++i)
818        CU->createGlobalVariableDIE(GVs.getElement(i));
819      DIArray SPs = CUNode.getSubprograms();
820      for (unsigned i = 0, e = SPs.getNumElements(); i != e; ++i)
821        constructSubprogramDIE(CU, SPs.getElement(i));
822      DIArray EnumTypes = CUNode.getEnumTypes();
823      for (unsigned i = 0, e = EnumTypes.getNumElements(); i != e; ++i)
824        CU->getOrCreateTypeDIE(EnumTypes.getElement(i));
825      DIArray RetainedTypes = CUNode.getRetainedTypes();
826      for (unsigned i = 0, e = RetainedTypes.getNumElements(); i != e; ++i)
827        CU->getOrCreateTypeDIE(RetainedTypes.getElement(i));
828    }
829  } else if (!collectLegacyDebugInfo(M))
830    return;
831
832  collectInfoFromNamedMDNodes(M);
833
834  // Tell MMI that we have debug info.
835  MMI->setDebugInfoAvailability(true);
836
837  // Prime section data.
838  SectionMap.insert(Asm->getObjFileLowering().getTextSection());
839}
840
841// Attach DW_AT_inline attribute with inlined subprogram DIEs.
842void DwarfDebug::computeInlinedDIEs() {
843  // Attach DW_AT_inline attribute with inlined subprogram DIEs.
844  for (SmallPtrSet<DIE *, 4>::iterator AI = InlinedSubprogramDIEs.begin(),
845         AE = InlinedSubprogramDIEs.end(); AI != AE; ++AI) {
846    DIE *ISP = *AI;
847    FirstCU->addUInt(ISP, dwarf::DW_AT_inline, 0, dwarf::DW_INL_inlined);
848  }
849  for (DenseMap<const MDNode *, DIE *>::iterator AI = AbstractSPDies.begin(),
850         AE = AbstractSPDies.end(); AI != AE; ++AI) {
851    DIE *ISP = AI->second;
852    if (InlinedSubprogramDIEs.count(ISP))
853      continue;
854    FirstCU->addUInt(ISP, dwarf::DW_AT_inline, 0, dwarf::DW_INL_inlined);
855  }
856}
857
858// Collect info for variables that were optimized out.
859void DwarfDebug::collectDeadVariables() {
860  const Module *M = MMI->getModule();
861  DenseMap<const MDNode *, LexicalScope *> DeadFnScopeMap;
862
863  if (NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu")) {
864    for (unsigned i = 0, e = CU_Nodes->getNumOperands(); i != e; ++i) {
865      DICompileUnit TheCU(CU_Nodes->getOperand(i));
866      DIArray Subprograms = TheCU.getSubprograms();
867      for (unsigned i = 0, e = Subprograms.getNumElements(); i != e; ++i) {
868        DISubprogram SP(Subprograms.getElement(i));
869        if (ProcessedSPNodes.count(SP) != 0) continue;
870        if (!SP.Verify()) continue;
871        if (!SP.isDefinition()) continue;
872        DIArray Variables = SP.getVariables();
873        if (Variables.getNumElements() == 0) continue;
874
875        LexicalScope *Scope =
876          new LexicalScope(NULL, DIDescriptor(SP), NULL, false);
877        DeadFnScopeMap[SP] = Scope;
878
879        // Construct subprogram DIE and add variables DIEs.
880        CompileUnit *SPCU = CUMap.lookup(TheCU);
881        assert(SPCU && "Unable to find Compile Unit!");
882        constructSubprogramDIE(SPCU, SP);
883        DIE *ScopeDIE = SPCU->getDIE(SP);
884        for (unsigned vi = 0, ve = Variables.getNumElements(); vi != ve; ++vi) {
885          DIVariable DV(Variables.getElement(vi));
886          if (!DV.Verify()) continue;
887          DbgVariable *NewVar = new DbgVariable(DV, NULL);
888          if (DIE *VariableDIE =
889              SPCU->constructVariableDIE(NewVar, Scope->isAbstractScope()))
890            ScopeDIE->addChild(VariableDIE);
891        }
892      }
893    }
894  }
895  DeleteContainerSeconds(DeadFnScopeMap);
896}
897
898void DwarfDebug::finalizeModuleInfo() {
899  // Collect info for variables that were optimized out.
900  collectDeadVariables();
901
902  // Attach DW_AT_inline attribute with inlined subprogram DIEs.
903  computeInlinedDIEs();
904
905  // Emit DW_AT_containing_type attribute to connect types with their
906  // vtable holding type.
907  for (DenseMap<const MDNode *, CompileUnit *>::iterator CUI = CUMap.begin(),
908         CUE = CUMap.end(); CUI != CUE; ++CUI) {
909    CompileUnit *TheCU = CUI->second;
910    TheCU->constructContainingTypeDIEs();
911  }
912
913   // Compute DIE offsets and sizes.
914  InfoHolder.computeSizeAndOffsets();
915  if (useSplitDwarf())
916    SkeletonHolder.computeSizeAndOffsets();
917}
918
919void DwarfDebug::endSections() {
920  // Standard sections final addresses.
921  Asm->OutStreamer.SwitchSection(Asm->getObjFileLowering().getTextSection());
922  Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("text_end"));
923  Asm->OutStreamer.SwitchSection(Asm->getObjFileLowering().getDataSection());
924  Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("data_end"));
925
926  // End text sections.
927  for (unsigned I = 0, E = SectionMap.size(); I != E; ++I) {
928    Asm->OutStreamer.SwitchSection(SectionMap[I]);
929    Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("section_end", I+1));
930  }
931}
932
933// Emit all Dwarf sections that should come after the content.
934void DwarfDebug::endModule() {
935
936  if (!FirstCU) return;
937
938  // End any existing sections.
939  // TODO: Does this need to happen?
940  endSections();
941
942  // Finalize the debug info for the module.
943  finalizeModuleInfo();
944
945  // Emit initial sections.
946  emitSectionLabels();
947
948  if (!useSplitDwarf()) {
949    // Emit all the DIEs into a debug info section.
950    emitDebugInfo();
951
952    // Corresponding abbreviations into a abbrev section.
953    emitAbbreviations();
954
955    // Emit info into a debug loc section.
956    emitDebugLoc();
957
958    // Emit info into a debug aranges section.
959    emitDebugARanges();
960
961    // Emit info into a debug ranges section.
962    emitDebugRanges();
963
964    // Emit info into a debug macinfo section.
965    emitDebugMacInfo();
966
967    // Emit inline info.
968    // TODO: When we don't need the option anymore we
969    // can remove all of the code that this section
970    // depends upon.
971    if (useDarwinGDBCompat())
972      emitDebugInlineInfo();
973  } else {
974    // TODO: Fill this in for separated debug sections and separate
975    // out information into new sections.
976
977    // Emit the debug info section and compile units.
978    emitDebugInfo();
979    emitDebugInfoDWO();
980
981    // Corresponding abbreviations into a abbrev section.
982    emitAbbreviations();
983    emitDebugAbbrevDWO();
984
985    // Emit info into a debug loc section.
986    emitDebugLoc();
987
988    // Emit info into a debug aranges section.
989    emitDebugARanges();
990
991    // Emit info into a debug ranges section.
992    emitDebugRanges();
993
994    // Emit info into a debug macinfo section.
995    emitDebugMacInfo();
996
997    // Emit DWO addresses.
998    InfoHolder.emitAddresses(Asm->getObjFileLowering().getDwarfAddrSection());
999
1000    // Emit inline info.
1001    // TODO: When we don't need the option anymore we
1002    // can remove all of the code that this section
1003    // depends upon.
1004    if (useDarwinGDBCompat())
1005      emitDebugInlineInfo();
1006  }
1007
1008  // Emit info into the dwarf accelerator table sections.
1009  if (useDwarfAccelTables()) {
1010    emitAccelNames();
1011    emitAccelObjC();
1012    emitAccelNamespaces();
1013    emitAccelTypes();
1014  }
1015
1016  // Emit info into a debug pubtypes section.
1017  // TODO: When we don't need the option anymore we can
1018  // remove all of the code that adds to the table.
1019  if (useDarwinGDBCompat())
1020    emitDebugPubTypes();
1021
1022  // Finally emit string information into a string table.
1023  emitDebugStr();
1024  if (useSplitDwarf())
1025    emitDebugStrDWO();
1026
1027  // clean up.
1028  SPMap.clear();
1029  for (DenseMap<const MDNode *, CompileUnit *>::iterator I = CUMap.begin(),
1030         E = CUMap.end(); I != E; ++I)
1031    delete I->second;
1032
1033  delete SkeletonCU;
1034
1035  // Reset these for the next Module if we have one.
1036  FirstCU = NULL;
1037  SkeletonCU = NULL;
1038}
1039
1040// Find abstract variable, if any, associated with Var.
1041DbgVariable *DwarfDebug::findAbstractVariable(DIVariable &DV,
1042                                              DebugLoc ScopeLoc) {
1043  LLVMContext &Ctx = DV->getContext();
1044  // More then one inlined variable corresponds to one abstract variable.
1045  DIVariable Var = cleanseInlinedVariable(DV, Ctx);
1046  DbgVariable *AbsDbgVariable = AbstractVariables.lookup(Var);
1047  if (AbsDbgVariable)
1048    return AbsDbgVariable;
1049
1050  LexicalScope *Scope = LScopes.findAbstractScope(ScopeLoc.getScope(Ctx));
1051  if (!Scope)
1052    return NULL;
1053
1054  AbsDbgVariable = new DbgVariable(Var, NULL);
1055  addScopeVariable(Scope, AbsDbgVariable);
1056  AbstractVariables[Var] = AbsDbgVariable;
1057  return AbsDbgVariable;
1058}
1059
1060// If Var is a current function argument then add it to CurrentFnArguments list.
1061bool DwarfDebug::addCurrentFnArgument(const MachineFunction *MF,
1062                                      DbgVariable *Var, LexicalScope *Scope) {
1063  if (!LScopes.isCurrentFunctionScope(Scope))
1064    return false;
1065  DIVariable DV = Var->getVariable();
1066  if (DV.getTag() != dwarf::DW_TAG_arg_variable)
1067    return false;
1068  unsigned ArgNo = DV.getArgNumber();
1069  if (ArgNo == 0)
1070    return false;
1071
1072  size_t Size = CurrentFnArguments.size();
1073  if (Size == 0)
1074    CurrentFnArguments.resize(MF->getFunction()->arg_size());
1075  // llvm::Function argument size is not good indicator of how many
1076  // arguments does the function have at source level.
1077  if (ArgNo > Size)
1078    CurrentFnArguments.resize(ArgNo * 2);
1079  CurrentFnArguments[ArgNo - 1] = Var;
1080  return true;
1081}
1082
1083// Collect variable information from side table maintained by MMI.
1084void
1085DwarfDebug::collectVariableInfoFromMMITable(const MachineFunction *MF,
1086                                   SmallPtrSet<const MDNode *, 16> &Processed) {
1087  MachineModuleInfo::VariableDbgInfoMapTy &VMap = MMI->getVariableDbgInfo();
1088  for (MachineModuleInfo::VariableDbgInfoMapTy::iterator VI = VMap.begin(),
1089         VE = VMap.end(); VI != VE; ++VI) {
1090    const MDNode *Var = VI->first;
1091    if (!Var) continue;
1092    Processed.insert(Var);
1093    DIVariable DV(Var);
1094    const std::pair<unsigned, DebugLoc> &VP = VI->second;
1095
1096    LexicalScope *Scope = LScopes.findLexicalScope(VP.second);
1097
1098    // If variable scope is not found then skip this variable.
1099    if (Scope == 0)
1100      continue;
1101
1102    DbgVariable *AbsDbgVariable = findAbstractVariable(DV, VP.second);
1103    DbgVariable *RegVar = new DbgVariable(DV, AbsDbgVariable);
1104    RegVar->setFrameIndex(VP.first);
1105    if (!addCurrentFnArgument(MF, RegVar, Scope))
1106      addScopeVariable(Scope, RegVar);
1107    if (AbsDbgVariable)
1108      AbsDbgVariable->setFrameIndex(VP.first);
1109  }
1110}
1111
1112// Return true if debug value, encoded by DBG_VALUE instruction, is in a
1113// defined reg.
1114static bool isDbgValueInDefinedReg(const MachineInstr *MI) {
1115  assert(MI->isDebugValue() && "Invalid DBG_VALUE machine instruction!");
1116  return MI->getNumOperands() == 3 &&
1117         MI->getOperand(0).isReg() && MI->getOperand(0).getReg() &&
1118         MI->getOperand(1).isImm() && MI->getOperand(1).getImm() == 0;
1119}
1120
1121// Get .debug_loc entry for the instruction range starting at MI.
1122static DotDebugLocEntry getDebugLocEntry(AsmPrinter *Asm,
1123                                         const MCSymbol *FLabel,
1124                                         const MCSymbol *SLabel,
1125                                         const MachineInstr *MI) {
1126  const MDNode *Var =  MI->getOperand(MI->getNumOperands() - 1).getMetadata();
1127
1128  if (MI->getNumOperands() != 3) {
1129    MachineLocation MLoc = Asm->getDebugValueLocation(MI);
1130    return DotDebugLocEntry(FLabel, SLabel, MLoc, Var);
1131  }
1132  if (MI->getOperand(0).isReg() && MI->getOperand(1).isImm()) {
1133    MachineLocation MLoc;
1134    MLoc.set(MI->getOperand(0).getReg(), MI->getOperand(1).getImm());
1135    return DotDebugLocEntry(FLabel, SLabel, MLoc, Var);
1136  }
1137  if (MI->getOperand(0).isImm())
1138    return DotDebugLocEntry(FLabel, SLabel, MI->getOperand(0).getImm());
1139  if (MI->getOperand(0).isFPImm())
1140    return DotDebugLocEntry(FLabel, SLabel, MI->getOperand(0).getFPImm());
1141  if (MI->getOperand(0).isCImm())
1142    return DotDebugLocEntry(FLabel, SLabel, MI->getOperand(0).getCImm());
1143
1144  llvm_unreachable("Unexpected 3 operand DBG_VALUE instruction!");
1145}
1146
1147// Find variables for each lexical scope.
1148void
1149DwarfDebug::collectVariableInfo(const MachineFunction *MF,
1150                                SmallPtrSet<const MDNode *, 16> &Processed) {
1151
1152  // collection info from MMI table.
1153  collectVariableInfoFromMMITable(MF, Processed);
1154
1155  for (SmallVectorImpl<const MDNode*>::const_iterator
1156         UVI = UserVariables.begin(), UVE = UserVariables.end(); UVI != UVE;
1157         ++UVI) {
1158    const MDNode *Var = *UVI;
1159    if (Processed.count(Var))
1160      continue;
1161
1162    // History contains relevant DBG_VALUE instructions for Var and instructions
1163    // clobbering it.
1164    SmallVectorImpl<const MachineInstr*> &History = DbgValues[Var];
1165    if (History.empty())
1166      continue;
1167    const MachineInstr *MInsn = History.front();
1168
1169    DIVariable DV(Var);
1170    LexicalScope *Scope = NULL;
1171    if (DV.getTag() == dwarf::DW_TAG_arg_variable &&
1172        DISubprogram(DV.getContext()).describes(MF->getFunction()))
1173      Scope = LScopes.getCurrentFunctionScope();
1174    else {
1175      if (DV.getVersion() <= LLVMDebugVersion9)
1176        Scope = LScopes.findLexicalScope(MInsn->getDebugLoc());
1177      else {
1178        if (MDNode *IA = DV.getInlinedAt())
1179          Scope = LScopes.findInlinedScope(DebugLoc::getFromDILocation(IA));
1180        else
1181          Scope = LScopes.findLexicalScope(cast<MDNode>(DV->getOperand(1)));
1182      }
1183    }
1184    // If variable scope is not found then skip this variable.
1185    if (!Scope)
1186      continue;
1187
1188    Processed.insert(DV);
1189    assert(MInsn->isDebugValue() && "History must begin with debug value");
1190    DbgVariable *AbsVar = findAbstractVariable(DV, MInsn->getDebugLoc());
1191    DbgVariable *RegVar = new DbgVariable(DV, AbsVar);
1192    if (!addCurrentFnArgument(MF, RegVar, Scope))
1193      addScopeVariable(Scope, RegVar);
1194    if (AbsVar)
1195      AbsVar->setMInsn(MInsn);
1196
1197    // Simplify ranges that are fully coalesced.
1198    if (History.size() <= 1 || (History.size() == 2 &&
1199                                MInsn->isIdenticalTo(History.back()))) {
1200      RegVar->setMInsn(MInsn);
1201      continue;
1202    }
1203
1204    // Handle multiple DBG_VALUE instructions describing one variable.
1205    RegVar->setDotDebugLocOffset(DotDebugLocEntries.size());
1206
1207    for (SmallVectorImpl<const MachineInstr*>::const_iterator
1208           HI = History.begin(), HE = History.end(); HI != HE; ++HI) {
1209      const MachineInstr *Begin = *HI;
1210      assert(Begin->isDebugValue() && "Invalid History entry");
1211
1212      // Check if DBG_VALUE is truncating a range.
1213      if (Begin->getNumOperands() > 1 && Begin->getOperand(0).isReg()
1214          && !Begin->getOperand(0).getReg())
1215        continue;
1216
1217      // Compute the range for a register location.
1218      const MCSymbol *FLabel = getLabelBeforeInsn(Begin);
1219      const MCSymbol *SLabel = 0;
1220
1221      if (HI + 1 == HE)
1222        // If Begin is the last instruction in History then its value is valid
1223        // until the end of the function.
1224        SLabel = FunctionEndSym;
1225      else {
1226        const MachineInstr *End = HI[1];
1227        DEBUG(dbgs() << "DotDebugLoc Pair:\n"
1228              << "\t" << *Begin << "\t" << *End << "\n");
1229        if (End->isDebugValue())
1230          SLabel = getLabelBeforeInsn(End);
1231        else {
1232          // End is a normal instruction clobbering the range.
1233          SLabel = getLabelAfterInsn(End);
1234          assert(SLabel && "Forgot label after clobber instruction");
1235          ++HI;
1236        }
1237      }
1238
1239      // The value is valid until the next DBG_VALUE or clobber.
1240      DotDebugLocEntries.push_back(getDebugLocEntry(Asm, FLabel, SLabel,
1241                                                    Begin));
1242    }
1243    DotDebugLocEntries.push_back(DotDebugLocEntry());
1244  }
1245
1246  // Collect info for variables that were optimized out.
1247  LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1248  DIArray Variables = DISubprogram(FnScope->getScopeNode()).getVariables();
1249  for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1250    DIVariable DV(Variables.getElement(i));
1251    if (!DV || !DV.Verify() || !Processed.insert(DV))
1252      continue;
1253    if (LexicalScope *Scope = LScopes.findLexicalScope(DV.getContext()))
1254      addScopeVariable(Scope, new DbgVariable(DV, NULL));
1255  }
1256}
1257
1258// Return Label preceding the instruction.
1259MCSymbol *DwarfDebug::getLabelBeforeInsn(const MachineInstr *MI) {
1260  MCSymbol *Label = LabelsBeforeInsn.lookup(MI);
1261  assert(Label && "Didn't insert label before instruction");
1262  return Label;
1263}
1264
1265// Return Label immediately following the instruction.
1266MCSymbol *DwarfDebug::getLabelAfterInsn(const MachineInstr *MI) {
1267  return LabelsAfterInsn.lookup(MI);
1268}
1269
1270// Process beginning of an instruction.
1271void DwarfDebug::beginInstruction(const MachineInstr *MI) {
1272  // Check if source location changes, but ignore DBG_VALUE locations.
1273  if (!MI->isDebugValue()) {
1274    DebugLoc DL = MI->getDebugLoc();
1275    if (DL != PrevInstLoc && (!DL.isUnknown() || UnknownLocations)) {
1276      unsigned Flags = 0;
1277      PrevInstLoc = DL;
1278      if (DL == PrologEndLoc) {
1279        Flags |= DWARF2_FLAG_PROLOGUE_END;
1280        PrologEndLoc = DebugLoc();
1281      }
1282      if (PrologEndLoc.isUnknown())
1283        Flags |= DWARF2_FLAG_IS_STMT;
1284
1285      if (!DL.isUnknown()) {
1286        const MDNode *Scope = DL.getScope(Asm->MF->getFunction()->getContext());
1287        recordSourceLine(DL.getLine(), DL.getCol(), Scope, Flags);
1288      } else
1289        recordSourceLine(0, 0, 0, 0);
1290    }
1291  }
1292
1293  // Insert labels where requested.
1294  DenseMap<const MachineInstr*, MCSymbol*>::iterator I =
1295    LabelsBeforeInsn.find(MI);
1296
1297  // No label needed.
1298  if (I == LabelsBeforeInsn.end())
1299    return;
1300
1301  // Label already assigned.
1302  if (I->second)
1303    return;
1304
1305  if (!PrevLabel) {
1306    PrevLabel = MMI->getContext().CreateTempSymbol();
1307    Asm->OutStreamer.EmitLabel(PrevLabel);
1308  }
1309  I->second = PrevLabel;
1310}
1311
1312// Process end of an instruction.
1313void DwarfDebug::endInstruction(const MachineInstr *MI) {
1314  // Don't create a new label after DBG_VALUE instructions.
1315  // They don't generate code.
1316  if (!MI->isDebugValue())
1317    PrevLabel = 0;
1318
1319  DenseMap<const MachineInstr*, MCSymbol*>::iterator I =
1320    LabelsAfterInsn.find(MI);
1321
1322  // No label needed.
1323  if (I == LabelsAfterInsn.end())
1324    return;
1325
1326  // Label already assigned.
1327  if (I->second)
1328    return;
1329
1330  // We need a label after this instruction.
1331  if (!PrevLabel) {
1332    PrevLabel = MMI->getContext().CreateTempSymbol();
1333    Asm->OutStreamer.EmitLabel(PrevLabel);
1334  }
1335  I->second = PrevLabel;
1336}
1337
1338// Each LexicalScope has first instruction and last instruction to mark
1339// beginning and end of a scope respectively. Create an inverse map that list
1340// scopes starts (and ends) with an instruction. One instruction may start (or
1341// end) multiple scopes. Ignore scopes that are not reachable.
1342void DwarfDebug::identifyScopeMarkers() {
1343  SmallVector<LexicalScope *, 4> WorkList;
1344  WorkList.push_back(LScopes.getCurrentFunctionScope());
1345  while (!WorkList.empty()) {
1346    LexicalScope *S = WorkList.pop_back_val();
1347
1348    const SmallVector<LexicalScope *, 4> &Children = S->getChildren();
1349    if (!Children.empty())
1350      for (SmallVector<LexicalScope *, 4>::const_iterator SI = Children.begin(),
1351             SE = Children.end(); SI != SE; ++SI)
1352        WorkList.push_back(*SI);
1353
1354    if (S->isAbstractScope())
1355      continue;
1356
1357    const SmallVector<InsnRange, 4> &Ranges = S->getRanges();
1358    if (Ranges.empty())
1359      continue;
1360    for (SmallVector<InsnRange, 4>::const_iterator RI = Ranges.begin(),
1361           RE = Ranges.end(); RI != RE; ++RI) {
1362      assert(RI->first && "InsnRange does not have first instruction!");
1363      assert(RI->second && "InsnRange does not have second instruction!");
1364      requestLabelBeforeInsn(RI->first);
1365      requestLabelAfterInsn(RI->second);
1366    }
1367  }
1368}
1369
1370// Get MDNode for DebugLoc's scope.
1371static MDNode *getScopeNode(DebugLoc DL, const LLVMContext &Ctx) {
1372  if (MDNode *InlinedAt = DL.getInlinedAt(Ctx))
1373    return getScopeNode(DebugLoc::getFromDILocation(InlinedAt), Ctx);
1374  return DL.getScope(Ctx);
1375}
1376
1377// Walk up the scope chain of given debug loc and find line number info
1378// for the function.
1379static DebugLoc getFnDebugLoc(DebugLoc DL, const LLVMContext &Ctx) {
1380  const MDNode *Scope = getScopeNode(DL, Ctx);
1381  DISubprogram SP = getDISubprogram(Scope);
1382  if (SP.Verify()) {
1383    // Check for number of operands since the compatibility is
1384    // cheap here.
1385    if (SP->getNumOperands() > 19)
1386      return DebugLoc::get(SP.getScopeLineNumber(), 0, SP);
1387    else
1388      return DebugLoc::get(SP.getLineNumber(), 0, SP);
1389  }
1390
1391  return DebugLoc();
1392}
1393
1394// Gather pre-function debug information.  Assumes being called immediately
1395// after the function entry point has been emitted.
1396void DwarfDebug::beginFunction(const MachineFunction *MF) {
1397  if (!MMI->hasDebugInfo()) return;
1398  LScopes.initialize(*MF);
1399  if (LScopes.empty()) return;
1400  identifyScopeMarkers();
1401
1402  FunctionBeginSym = Asm->GetTempSymbol("func_begin",
1403                                        Asm->getFunctionNumber());
1404  // Assumes in correct section after the entry point.
1405  Asm->OutStreamer.EmitLabel(FunctionBeginSym);
1406
1407  assert(UserVariables.empty() && DbgValues.empty() && "Maps weren't cleaned");
1408
1409  const TargetRegisterInfo *TRI = Asm->TM.getRegisterInfo();
1410  // LiveUserVar - Map physreg numbers to the MDNode they contain.
1411  std::vector<const MDNode*> LiveUserVar(TRI->getNumRegs());
1412
1413  for (MachineFunction::const_iterator I = MF->begin(), E = MF->end();
1414       I != E; ++I) {
1415    bool AtBlockEntry = true;
1416    for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end();
1417         II != IE; ++II) {
1418      const MachineInstr *MI = II;
1419
1420      if (MI->isDebugValue()) {
1421        assert(MI->getNumOperands() > 1 && "Invalid machine instruction!");
1422
1423        // Keep track of user variables.
1424        const MDNode *Var =
1425          MI->getOperand(MI->getNumOperands() - 1).getMetadata();
1426
1427        // Variable is in a register, we need to check for clobbers.
1428        if (isDbgValueInDefinedReg(MI))
1429          LiveUserVar[MI->getOperand(0).getReg()] = Var;
1430
1431        // Check the history of this variable.
1432        SmallVectorImpl<const MachineInstr*> &History = DbgValues[Var];
1433        if (History.empty()) {
1434          UserVariables.push_back(Var);
1435          // The first mention of a function argument gets the FunctionBeginSym
1436          // label, so arguments are visible when breaking at function entry.
1437          DIVariable DV(Var);
1438          if (DV.Verify() && DV.getTag() == dwarf::DW_TAG_arg_variable &&
1439              DISubprogram(getDISubprogram(DV.getContext()))
1440                .describes(MF->getFunction()))
1441            LabelsBeforeInsn[MI] = FunctionBeginSym;
1442        } else {
1443          // We have seen this variable before. Try to coalesce DBG_VALUEs.
1444          const MachineInstr *Prev = History.back();
1445          if (Prev->isDebugValue()) {
1446            // Coalesce identical entries at the end of History.
1447            if (History.size() >= 2 &&
1448                Prev->isIdenticalTo(History[History.size() - 2])) {
1449              DEBUG(dbgs() << "Coalescing identical DBG_VALUE entries:\n"
1450                    << "\t" << *Prev
1451                    << "\t" << *History[History.size() - 2] << "\n");
1452              History.pop_back();
1453            }
1454
1455            // Terminate old register assignments that don't reach MI;
1456            MachineFunction::const_iterator PrevMBB = Prev->getParent();
1457            if (PrevMBB != I && (!AtBlockEntry || llvm::next(PrevMBB) != I) &&
1458                isDbgValueInDefinedReg(Prev)) {
1459              // Previous register assignment needs to terminate at the end of
1460              // its basic block.
1461              MachineBasicBlock::const_iterator LastMI =
1462                PrevMBB->getLastNonDebugInstr();
1463              if (LastMI == PrevMBB->end()) {
1464                // Drop DBG_VALUE for empty range.
1465                DEBUG(dbgs() << "Dropping DBG_VALUE for empty range:\n"
1466                      << "\t" << *Prev << "\n");
1467                History.pop_back();
1468              }
1469              else {
1470                // Terminate after LastMI.
1471                History.push_back(LastMI);
1472              }
1473            }
1474          }
1475        }
1476        History.push_back(MI);
1477      } else {
1478        // Not a DBG_VALUE instruction.
1479        if (!MI->isLabel())
1480          AtBlockEntry = false;
1481
1482        // First known non-DBG_VALUE and non-frame setup location marks
1483        // the beginning of the function body.
1484        if (!MI->getFlag(MachineInstr::FrameSetup) &&
1485            (PrologEndLoc.isUnknown() && !MI->getDebugLoc().isUnknown()))
1486          PrologEndLoc = MI->getDebugLoc();
1487
1488        // Check if the instruction clobbers any registers with debug vars.
1489        for (MachineInstr::const_mop_iterator MOI = MI->operands_begin(),
1490               MOE = MI->operands_end(); MOI != MOE; ++MOI) {
1491          if (!MOI->isReg() || !MOI->isDef() || !MOI->getReg())
1492            continue;
1493          for (MCRegAliasIterator AI(MOI->getReg(), TRI, true);
1494               AI.isValid(); ++AI) {
1495            unsigned Reg = *AI;
1496            const MDNode *Var = LiveUserVar[Reg];
1497            if (!Var)
1498              continue;
1499            // Reg is now clobbered.
1500            LiveUserVar[Reg] = 0;
1501
1502            // Was MD last defined by a DBG_VALUE referring to Reg?
1503            DbgValueHistoryMap::iterator HistI = DbgValues.find(Var);
1504            if (HistI == DbgValues.end())
1505              continue;
1506            SmallVectorImpl<const MachineInstr*> &History = HistI->second;
1507            if (History.empty())
1508              continue;
1509            const MachineInstr *Prev = History.back();
1510            // Sanity-check: Register assignments are terminated at the end of
1511            // their block.
1512            if (!Prev->isDebugValue() || Prev->getParent() != MI->getParent())
1513              continue;
1514            // Is the variable still in Reg?
1515            if (!isDbgValueInDefinedReg(Prev) ||
1516                Prev->getOperand(0).getReg() != Reg)
1517              continue;
1518            // Var is clobbered. Make sure the next instruction gets a label.
1519            History.push_back(MI);
1520          }
1521        }
1522      }
1523    }
1524  }
1525
1526  for (DbgValueHistoryMap::iterator I = DbgValues.begin(), E = DbgValues.end();
1527       I != E; ++I) {
1528    SmallVectorImpl<const MachineInstr*> &History = I->second;
1529    if (History.empty())
1530      continue;
1531
1532    // Make sure the final register assignments are terminated.
1533    const MachineInstr *Prev = History.back();
1534    if (Prev->isDebugValue() && isDbgValueInDefinedReg(Prev)) {
1535      const MachineBasicBlock *PrevMBB = Prev->getParent();
1536      MachineBasicBlock::const_iterator LastMI =
1537        PrevMBB->getLastNonDebugInstr();
1538      if (LastMI == PrevMBB->end())
1539        // Drop DBG_VALUE for empty range.
1540        History.pop_back();
1541      else {
1542        // Terminate after LastMI.
1543        History.push_back(LastMI);
1544      }
1545    }
1546    // Request labels for the full history.
1547    for (unsigned i = 0, e = History.size(); i != e; ++i) {
1548      const MachineInstr *MI = History[i];
1549      if (MI->isDebugValue())
1550        requestLabelBeforeInsn(MI);
1551      else
1552        requestLabelAfterInsn(MI);
1553    }
1554  }
1555
1556  PrevInstLoc = DebugLoc();
1557  PrevLabel = FunctionBeginSym;
1558
1559  // Record beginning of function.
1560  if (!PrologEndLoc.isUnknown()) {
1561    DebugLoc FnStartDL = getFnDebugLoc(PrologEndLoc,
1562                                       MF->getFunction()->getContext());
1563    recordSourceLine(FnStartDL.getLine(), FnStartDL.getCol(),
1564                     FnStartDL.getScope(MF->getFunction()->getContext()),
1565    // We'd like to list the prologue as "not statements" but GDB behaves
1566    // poorly if we do that. Revisit this with caution/GDB (7.5+) testing.
1567                     DWARF2_FLAG_IS_STMT);
1568  }
1569}
1570
1571void DwarfDebug::addScopeVariable(LexicalScope *LS, DbgVariable *Var) {
1572//  SmallVector<DbgVariable *, 8> &Vars = ScopeVariables.lookup(LS);
1573  ScopeVariables[LS].push_back(Var);
1574//  Vars.push_back(Var);
1575}
1576
1577// Gather and emit post-function debug information.
1578void DwarfDebug::endFunction(const MachineFunction *MF) {
1579  if (!MMI->hasDebugInfo() || LScopes.empty()) return;
1580
1581  // Define end label for subprogram.
1582  FunctionEndSym = Asm->GetTempSymbol("func_end",
1583                                      Asm->getFunctionNumber());
1584  // Assumes in correct section after the entry point.
1585  Asm->OutStreamer.EmitLabel(FunctionEndSym);
1586
1587  SmallPtrSet<const MDNode *, 16> ProcessedVars;
1588  collectVariableInfo(MF, ProcessedVars);
1589
1590  LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1591  CompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1592  assert(TheCU && "Unable to find compile unit!");
1593
1594  // Construct abstract scopes.
1595  ArrayRef<LexicalScope *> AList = LScopes.getAbstractScopesList();
1596  for (unsigned i = 0, e = AList.size(); i != e; ++i) {
1597    LexicalScope *AScope = AList[i];
1598    DISubprogram SP(AScope->getScopeNode());
1599    if (SP.Verify()) {
1600      // Collect info for variables that were optimized out.
1601      DIArray Variables = SP.getVariables();
1602      for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1603        DIVariable DV(Variables.getElement(i));
1604        if (!DV || !DV.Verify() || !ProcessedVars.insert(DV))
1605          continue;
1606        // Check that DbgVariable for DV wasn't created earlier, when
1607        // findAbstractVariable() was called for inlined instance of DV.
1608        LLVMContext &Ctx = DV->getContext();
1609        DIVariable CleanDV = cleanseInlinedVariable(DV, Ctx);
1610        if (AbstractVariables.lookup(CleanDV))
1611          continue;
1612        if (LexicalScope *Scope = LScopes.findAbstractScope(DV.getContext()))
1613          addScopeVariable(Scope, new DbgVariable(DV, NULL));
1614      }
1615    }
1616    if (ProcessedSPNodes.count(AScope->getScopeNode()) == 0)
1617      constructScopeDIE(TheCU, AScope);
1618  }
1619
1620  DIE *CurFnDIE = constructScopeDIE(TheCU, FnScope);
1621
1622  if (!MF->getTarget().Options.DisableFramePointerElim(*MF))
1623    TheCU->addFlag(CurFnDIE, dwarf::DW_AT_APPLE_omit_frame_ptr);
1624
1625  DebugFrames.push_back(FunctionDebugFrameInfo(Asm->getFunctionNumber(),
1626                                               MMI->getFrameMoves()));
1627
1628  // Clear debug info
1629  for (DenseMap<LexicalScope *, SmallVector<DbgVariable *, 8> >::iterator
1630         I = ScopeVariables.begin(), E = ScopeVariables.end(); I != E; ++I)
1631    DeleteContainerPointers(I->second);
1632  ScopeVariables.clear();
1633  DeleteContainerPointers(CurrentFnArguments);
1634  UserVariables.clear();
1635  DbgValues.clear();
1636  AbstractVariables.clear();
1637  LabelsBeforeInsn.clear();
1638  LabelsAfterInsn.clear();
1639  PrevLabel = NULL;
1640}
1641
1642// Register a source line with debug info. Returns the  unique label that was
1643// emitted and which provides correspondence to the source line list.
1644void DwarfDebug::recordSourceLine(unsigned Line, unsigned Col, const MDNode *S,
1645                                  unsigned Flags) {
1646  StringRef Fn;
1647  StringRef Dir;
1648  unsigned Src = 1;
1649  if (S) {
1650    DIDescriptor Scope(S);
1651
1652    if (Scope.isCompileUnit()) {
1653      DICompileUnit CU(S);
1654      Fn = CU.getFilename();
1655      Dir = CU.getDirectory();
1656    } else if (Scope.isFile()) {
1657      DIFile F(S);
1658      Fn = F.getFilename();
1659      Dir = F.getDirectory();
1660    } else if (Scope.isSubprogram()) {
1661      DISubprogram SP(S);
1662      Fn = SP.getFilename();
1663      Dir = SP.getDirectory();
1664    } else if (Scope.isLexicalBlockFile()) {
1665      DILexicalBlockFile DBF(S);
1666      Fn = DBF.getFilename();
1667      Dir = DBF.getDirectory();
1668    } else if (Scope.isLexicalBlock()) {
1669      DILexicalBlock DB(S);
1670      Fn = DB.getFilename();
1671      Dir = DB.getDirectory();
1672    } else
1673      llvm_unreachable("Unexpected scope info");
1674
1675    Src = getOrCreateSourceID(Fn, Dir);
1676  }
1677  Asm->OutStreamer.EmitDwarfLocDirective(Src, Line, Col, Flags, 0, 0, Fn);
1678}
1679
1680//===----------------------------------------------------------------------===//
1681// Emit Methods
1682//===----------------------------------------------------------------------===//
1683
1684// Compute the size and offset of a DIE.
1685unsigned
1686DwarfUnits::computeSizeAndOffset(DIE *Die, unsigned Offset) {
1687  // Get the children.
1688  const std::vector<DIE *> &Children = Die->getChildren();
1689
1690  // Record the abbreviation.
1691  assignAbbrevNumber(Die->getAbbrev());
1692
1693  // Get the abbreviation for this DIE.
1694  unsigned AbbrevNumber = Die->getAbbrevNumber();
1695  const DIEAbbrev *Abbrev = Abbreviations->at(AbbrevNumber - 1);
1696
1697  // Set DIE offset
1698  Die->setOffset(Offset);
1699
1700  // Start the size with the size of abbreviation code.
1701  Offset += MCAsmInfo::getULEB128Size(AbbrevNumber);
1702
1703  const SmallVector<DIEValue*, 32> &Values = Die->getValues();
1704  const SmallVector<DIEAbbrevData, 8> &AbbrevData = Abbrev->getData();
1705
1706  // Size the DIE attribute values.
1707  for (unsigned i = 0, N = Values.size(); i < N; ++i)
1708    // Size attribute value.
1709    Offset += Values[i]->SizeOf(Asm, AbbrevData[i].getForm());
1710
1711  // Size the DIE children if any.
1712  if (!Children.empty()) {
1713    assert(Abbrev->getChildrenFlag() == dwarf::DW_CHILDREN_yes &&
1714           "Children flag not set");
1715
1716    for (unsigned j = 0, M = Children.size(); j < M; ++j)
1717      Offset = computeSizeAndOffset(Children[j], Offset);
1718
1719    // End of children marker.
1720    Offset += sizeof(int8_t);
1721  }
1722
1723  Die->setSize(Offset - Die->getOffset());
1724  return Offset;
1725}
1726
1727// Compute the size and offset of all the DIEs.
1728void DwarfUnits::computeSizeAndOffsets() {
1729  for (SmallVector<CompileUnit *, 1>::iterator I = CUs.begin(),
1730         E = CUs.end(); I != E; ++I) {
1731    unsigned Offset =
1732      sizeof(int32_t) + // Length of Compilation Unit Info
1733      sizeof(int16_t) + // DWARF version number
1734      sizeof(int32_t) + // Offset Into Abbrev. Section
1735      sizeof(int8_t);   // Pointer Size (in bytes)
1736
1737    computeSizeAndOffset((*I)->getCUDie(), Offset);
1738  }
1739}
1740
1741// Emit initial Dwarf sections with a label at the start of each one.
1742void DwarfDebug::emitSectionLabels() {
1743  const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
1744
1745  // Dwarf sections base addresses.
1746  DwarfInfoSectionSym =
1747    emitSectionSym(Asm, TLOF.getDwarfInfoSection(), "section_info");
1748  DwarfAbbrevSectionSym =
1749    emitSectionSym(Asm, TLOF.getDwarfAbbrevSection(), "section_abbrev");
1750  if (useSplitDwarf())
1751    DwarfAbbrevDWOSectionSym =
1752      emitSectionSym(Asm, TLOF.getDwarfAbbrevDWOSection(),
1753                     "section_abbrev_dwo");
1754  emitSectionSym(Asm, TLOF.getDwarfARangesSection());
1755
1756  if (const MCSection *MacroInfo = TLOF.getDwarfMacroInfoSection())
1757    emitSectionSym(Asm, MacroInfo);
1758
1759  emitSectionSym(Asm, TLOF.getDwarfLineSection(), "section_line");
1760  emitSectionSym(Asm, TLOF.getDwarfLocSection());
1761  emitSectionSym(Asm, TLOF.getDwarfPubTypesSection());
1762  DwarfStrSectionSym =
1763    emitSectionSym(Asm, TLOF.getDwarfStrSection(), "info_string");
1764  if (useSplitDwarf())
1765    DwarfStrDWOSectionSym =
1766      emitSectionSym(Asm, TLOF.getDwarfStrDWOSection(), "skel_string");
1767  DwarfDebugRangeSectionSym = emitSectionSym(Asm, TLOF.getDwarfRangesSection(),
1768                                             "debug_range");
1769
1770  DwarfDebugLocSectionSym = emitSectionSym(Asm, TLOF.getDwarfLocSection(),
1771                                           "section_debug_loc");
1772
1773  TextSectionSym = emitSectionSym(Asm, TLOF.getTextSection(), "text_begin");
1774  emitSectionSym(Asm, TLOF.getDataSection());
1775}
1776
1777// Recursively emits a debug information entry.
1778void DwarfDebug::emitDIE(DIE *Die, std::vector<DIEAbbrev *> *Abbrevs) {
1779  // Get the abbreviation for this DIE.
1780  unsigned AbbrevNumber = Die->getAbbrevNumber();
1781  const DIEAbbrev *Abbrev = Abbrevs->at(AbbrevNumber - 1);
1782
1783  // Emit the code (index) for the abbreviation.
1784  if (Asm->isVerbose())
1785    Asm->OutStreamer.AddComment("Abbrev [" + Twine(AbbrevNumber) + "] 0x" +
1786                                Twine::utohexstr(Die->getOffset()) + ":0x" +
1787                                Twine::utohexstr(Die->getSize()) + " " +
1788                                dwarf::TagString(Abbrev->getTag()));
1789  Asm->EmitULEB128(AbbrevNumber);
1790
1791  const SmallVector<DIEValue*, 32> &Values = Die->getValues();
1792  const SmallVector<DIEAbbrevData, 8> &AbbrevData = Abbrev->getData();
1793
1794  // Emit the DIE attribute values.
1795  for (unsigned i = 0, N = Values.size(); i < N; ++i) {
1796    unsigned Attr = AbbrevData[i].getAttribute();
1797    unsigned Form = AbbrevData[i].getForm();
1798    assert(Form && "Too many attributes for DIE (check abbreviation)");
1799
1800    if (Asm->isVerbose())
1801      Asm->OutStreamer.AddComment(dwarf::AttributeString(Attr));
1802
1803    switch (Attr) {
1804    case dwarf::DW_AT_abstract_origin: {
1805      DIEEntry *E = cast<DIEEntry>(Values[i]);
1806      DIE *Origin = E->getEntry();
1807      unsigned Addr = Origin->getOffset();
1808      Asm->EmitInt32(Addr);
1809      break;
1810    }
1811    case dwarf::DW_AT_ranges: {
1812      // DW_AT_range Value encodes offset in debug_range section.
1813      DIEInteger *V = cast<DIEInteger>(Values[i]);
1814
1815      if (Asm->MAI->doesDwarfUseRelocationsAcrossSections()) {
1816        Asm->EmitLabelPlusOffset(DwarfDebugRangeSectionSym,
1817                                 V->getValue(),
1818                                 4);
1819      } else {
1820        Asm->EmitLabelOffsetDifference(DwarfDebugRangeSectionSym,
1821                                       V->getValue(),
1822                                       DwarfDebugRangeSectionSym,
1823                                       4);
1824      }
1825      break;
1826    }
1827    case dwarf::DW_AT_location: {
1828      if (DIELabel *L = dyn_cast<DIELabel>(Values[i])) {
1829        if (Asm->MAI->doesDwarfUseRelocationsAcrossSections())
1830          Asm->EmitLabelReference(L->getValue(), 4);
1831        else
1832          Asm->EmitLabelDifference(L->getValue(), DwarfDebugLocSectionSym, 4);
1833      } else {
1834        Values[i]->EmitValue(Asm, Form);
1835      }
1836      break;
1837    }
1838    case dwarf::DW_AT_accessibility: {
1839      if (Asm->isVerbose()) {
1840        DIEInteger *V = cast<DIEInteger>(Values[i]);
1841        Asm->OutStreamer.AddComment(dwarf::AccessibilityString(V->getValue()));
1842      }
1843      Values[i]->EmitValue(Asm, Form);
1844      break;
1845    }
1846    default:
1847      // Emit an attribute using the defined form.
1848      Values[i]->EmitValue(Asm, Form);
1849      break;
1850    }
1851  }
1852
1853  // Emit the DIE children if any.
1854  if (Abbrev->getChildrenFlag() == dwarf::DW_CHILDREN_yes) {
1855    const std::vector<DIE *> &Children = Die->getChildren();
1856
1857    for (unsigned j = 0, M = Children.size(); j < M; ++j)
1858      emitDIE(Children[j], Abbrevs);
1859
1860    if (Asm->isVerbose())
1861      Asm->OutStreamer.AddComment("End Of Children Mark");
1862    Asm->EmitInt8(0);
1863  }
1864}
1865
1866// Emit the various dwarf units to the unit section USection with
1867// the abbreviations going into ASection.
1868void DwarfUnits::emitUnits(DwarfDebug *DD,
1869                           const MCSection *USection,
1870                           const MCSection *ASection,
1871                           const MCSymbol *ASectionSym) {
1872  Asm->OutStreamer.SwitchSection(USection);
1873  for (SmallVector<CompileUnit *, 1>::iterator I = CUs.begin(),
1874         E = CUs.end(); I != E; ++I) {
1875    CompileUnit *TheCU = *I;
1876    DIE *Die = TheCU->getCUDie();
1877
1878    // Emit the compile units header.
1879    Asm->OutStreamer
1880      .EmitLabel(Asm->GetTempSymbol(USection->getLabelBeginName(),
1881                                    TheCU->getUniqueID()));
1882
1883    // Emit size of content not including length itself
1884    unsigned ContentSize = Die->getSize() +
1885      sizeof(int16_t) + // DWARF version number
1886      sizeof(int32_t) + // Offset Into Abbrev. Section
1887      sizeof(int8_t);   // Pointer Size (in bytes)
1888
1889    Asm->OutStreamer.AddComment("Length of Compilation Unit Info");
1890    Asm->EmitInt32(ContentSize);
1891    Asm->OutStreamer.AddComment("DWARF version number");
1892    Asm->EmitInt16(dwarf::DWARF_VERSION);
1893    Asm->OutStreamer.AddComment("Offset Into Abbrev. Section");
1894    Asm->EmitSectionOffset(Asm->GetTempSymbol(ASection->getLabelBeginName()),
1895                           ASectionSym);
1896    Asm->OutStreamer.AddComment("Address Size (in bytes)");
1897    Asm->EmitInt8(Asm->getDataLayout().getPointerSize());
1898
1899    DD->emitDIE(Die, Abbreviations);
1900    Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol(USection->getLabelEndName(),
1901                                                  TheCU->getUniqueID()));
1902  }
1903}
1904
1905// Emit the debug info section.
1906void DwarfDebug::emitDebugInfo() {
1907  DwarfUnits &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1908
1909  Holder.emitUnits(this, Asm->getObjFileLowering().getDwarfInfoSection(),
1910                   Asm->getObjFileLowering().getDwarfAbbrevSection(),
1911                   DwarfAbbrevSectionSym);
1912}
1913
1914// Emit the abbreviation section.
1915void DwarfDebug::emitAbbreviations() {
1916  if (!useSplitDwarf())
1917    emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevSection(),
1918                &Abbreviations);
1919  else
1920    emitSkeletonAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevSection());
1921}
1922
1923void DwarfDebug::emitAbbrevs(const MCSection *Section,
1924                             std::vector<DIEAbbrev *> *Abbrevs) {
1925  // Check to see if it is worth the effort.
1926  if (!Abbrevs->empty()) {
1927    // Start the debug abbrev section.
1928    Asm->OutStreamer.SwitchSection(Section);
1929
1930    MCSymbol *Begin = Asm->GetTempSymbol(Section->getLabelBeginName());
1931    Asm->OutStreamer.EmitLabel(Begin);
1932
1933    // For each abbrevation.
1934    for (unsigned i = 0, N = Abbrevs->size(); i < N; ++i) {
1935      // Get abbreviation data
1936      const DIEAbbrev *Abbrev = Abbrevs->at(i);
1937
1938      // Emit the abbrevations code (base 1 index.)
1939      Asm->EmitULEB128(Abbrev->getNumber(), "Abbreviation Code");
1940
1941      // Emit the abbreviations data.
1942      Abbrev->Emit(Asm);
1943    }
1944
1945    // Mark end of abbreviations.
1946    Asm->EmitULEB128(0, "EOM(3)");
1947
1948    MCSymbol *End = Asm->GetTempSymbol(Section->getLabelEndName());
1949    Asm->OutStreamer.EmitLabel(End);
1950  }
1951}
1952
1953// Emit the last address of the section and the end of the line matrix.
1954void DwarfDebug::emitEndOfLineMatrix(unsigned SectionEnd) {
1955  // Define last address of section.
1956  Asm->OutStreamer.AddComment("Extended Op");
1957  Asm->EmitInt8(0);
1958
1959  Asm->OutStreamer.AddComment("Op size");
1960  Asm->EmitInt8(Asm->getDataLayout().getPointerSize() + 1);
1961  Asm->OutStreamer.AddComment("DW_LNE_set_address");
1962  Asm->EmitInt8(dwarf::DW_LNE_set_address);
1963
1964  Asm->OutStreamer.AddComment("Section end label");
1965
1966  Asm->OutStreamer.EmitSymbolValue(Asm->GetTempSymbol("section_end",SectionEnd),
1967                                   Asm->getDataLayout().getPointerSize());
1968
1969  // Mark end of matrix.
1970  Asm->OutStreamer.AddComment("DW_LNE_end_sequence");
1971  Asm->EmitInt8(0);
1972  Asm->EmitInt8(1);
1973  Asm->EmitInt8(1);
1974}
1975
1976// Emit visible names into a hashed accelerator table section.
1977void DwarfDebug::emitAccelNames() {
1978  DwarfAccelTable AT(DwarfAccelTable::Atom(DwarfAccelTable::eAtomTypeDIEOffset,
1979                                           dwarf::DW_FORM_data4));
1980  for (DenseMap<const MDNode *, CompileUnit *>::iterator I = CUMap.begin(),
1981         E = CUMap.end(); I != E; ++I) {
1982    CompileUnit *TheCU = I->second;
1983    const StringMap<std::vector<DIE*> > &Names = TheCU->getAccelNames();
1984    for (StringMap<std::vector<DIE*> >::const_iterator
1985           GI = Names.begin(), GE = Names.end(); GI != GE; ++GI) {
1986      const char *Name = GI->getKeyData();
1987      const std::vector<DIE *> &Entities = GI->second;
1988      for (std::vector<DIE *>::const_iterator DI = Entities.begin(),
1989             DE = Entities.end(); DI != DE; ++DI)
1990        AT.AddName(Name, (*DI));
1991    }
1992  }
1993
1994  AT.FinalizeTable(Asm, "Names");
1995  Asm->OutStreamer.SwitchSection(
1996    Asm->getObjFileLowering().getDwarfAccelNamesSection());
1997  MCSymbol *SectionBegin = Asm->GetTempSymbol("names_begin");
1998  Asm->OutStreamer.EmitLabel(SectionBegin);
1999
2000  // Emit the full data.
2001  AT.Emit(Asm, SectionBegin, &InfoHolder);
2002}
2003
2004// Emit objective C classes and categories into a hashed accelerator table
2005// section.
2006void DwarfDebug::emitAccelObjC() {
2007  DwarfAccelTable AT(DwarfAccelTable::Atom(DwarfAccelTable::eAtomTypeDIEOffset,
2008                                           dwarf::DW_FORM_data4));
2009  for (DenseMap<const MDNode *, CompileUnit *>::iterator I = CUMap.begin(),
2010         E = CUMap.end(); I != E; ++I) {
2011    CompileUnit *TheCU = I->second;
2012    const StringMap<std::vector<DIE*> > &Names = TheCU->getAccelObjC();
2013    for (StringMap<std::vector<DIE*> >::const_iterator
2014           GI = Names.begin(), GE = Names.end(); GI != GE; ++GI) {
2015      const char *Name = GI->getKeyData();
2016      const std::vector<DIE *> &Entities = GI->second;
2017      for (std::vector<DIE *>::const_iterator DI = Entities.begin(),
2018             DE = Entities.end(); DI != DE; ++DI)
2019        AT.AddName(Name, (*DI));
2020    }
2021  }
2022
2023  AT.FinalizeTable(Asm, "ObjC");
2024  Asm->OutStreamer.SwitchSection(Asm->getObjFileLowering()
2025                                 .getDwarfAccelObjCSection());
2026  MCSymbol *SectionBegin = Asm->GetTempSymbol("objc_begin");
2027  Asm->OutStreamer.EmitLabel(SectionBegin);
2028
2029  // Emit the full data.
2030  AT.Emit(Asm, SectionBegin, &InfoHolder);
2031}
2032
2033// Emit namespace dies into a hashed accelerator table.
2034void DwarfDebug::emitAccelNamespaces() {
2035  DwarfAccelTable AT(DwarfAccelTable::Atom(DwarfAccelTable::eAtomTypeDIEOffset,
2036                                           dwarf::DW_FORM_data4));
2037  for (DenseMap<const MDNode *, CompileUnit *>::iterator I = CUMap.begin(),
2038         E = CUMap.end(); I != E; ++I) {
2039    CompileUnit *TheCU = I->second;
2040    const StringMap<std::vector<DIE*> > &Names = TheCU->getAccelNamespace();
2041    for (StringMap<std::vector<DIE*> >::const_iterator
2042           GI = Names.begin(), GE = Names.end(); GI != GE; ++GI) {
2043      const char *Name = GI->getKeyData();
2044      const std::vector<DIE *> &Entities = GI->second;
2045      for (std::vector<DIE *>::const_iterator DI = Entities.begin(),
2046             DE = Entities.end(); DI != DE; ++DI)
2047        AT.AddName(Name, (*DI));
2048    }
2049  }
2050
2051  AT.FinalizeTable(Asm, "namespac");
2052  Asm->OutStreamer.SwitchSection(Asm->getObjFileLowering()
2053                                 .getDwarfAccelNamespaceSection());
2054  MCSymbol *SectionBegin = Asm->GetTempSymbol("namespac_begin");
2055  Asm->OutStreamer.EmitLabel(SectionBegin);
2056
2057  // Emit the full data.
2058  AT.Emit(Asm, SectionBegin, &InfoHolder);
2059}
2060
2061// Emit type dies into a hashed accelerator table.
2062void DwarfDebug::emitAccelTypes() {
2063  std::vector<DwarfAccelTable::Atom> Atoms;
2064  Atoms.push_back(DwarfAccelTable::Atom(DwarfAccelTable::eAtomTypeDIEOffset,
2065                                        dwarf::DW_FORM_data4));
2066  Atoms.push_back(DwarfAccelTable::Atom(DwarfAccelTable::eAtomTypeTag,
2067                                        dwarf::DW_FORM_data2));
2068  Atoms.push_back(DwarfAccelTable::Atom(DwarfAccelTable::eAtomTypeTypeFlags,
2069                                        dwarf::DW_FORM_data1));
2070  DwarfAccelTable AT(Atoms);
2071  for (DenseMap<const MDNode *, CompileUnit *>::iterator I = CUMap.begin(),
2072         E = CUMap.end(); I != E; ++I) {
2073    CompileUnit *TheCU = I->second;
2074    const StringMap<std::vector<std::pair<DIE*, unsigned > > > &Names
2075      = TheCU->getAccelTypes();
2076    for (StringMap<std::vector<std::pair<DIE*, unsigned> > >::const_iterator
2077           GI = Names.begin(), GE = Names.end(); GI != GE; ++GI) {
2078      const char *Name = GI->getKeyData();
2079      const std::vector<std::pair<DIE *, unsigned> > &Entities = GI->second;
2080      for (std::vector<std::pair<DIE *, unsigned> >::const_iterator DI
2081             = Entities.begin(), DE = Entities.end(); DI !=DE; ++DI)
2082        AT.AddName(Name, (*DI).first, (*DI).second);
2083    }
2084  }
2085
2086  AT.FinalizeTable(Asm, "types");
2087  Asm->OutStreamer.SwitchSection(Asm->getObjFileLowering()
2088                                 .getDwarfAccelTypesSection());
2089  MCSymbol *SectionBegin = Asm->GetTempSymbol("types_begin");
2090  Asm->OutStreamer.EmitLabel(SectionBegin);
2091
2092  // Emit the full data.
2093  AT.Emit(Asm, SectionBegin, &InfoHolder);
2094}
2095
2096void DwarfDebug::emitDebugPubTypes() {
2097  for (DenseMap<const MDNode *, CompileUnit *>::iterator I = CUMap.begin(),
2098         E = CUMap.end(); I != E; ++I) {
2099    CompileUnit *TheCU = I->second;
2100    // Start the dwarf pubtypes section.
2101    Asm->OutStreamer.SwitchSection(
2102      Asm->getObjFileLowering().getDwarfPubTypesSection());
2103    Asm->OutStreamer.AddComment("Length of Public Types Info");
2104    Asm->EmitLabelDifference(
2105      Asm->GetTempSymbol("pubtypes_end", TheCU->getUniqueID()),
2106      Asm->GetTempSymbol("pubtypes_begin", TheCU->getUniqueID()), 4);
2107
2108    Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("pubtypes_begin",
2109                                                  TheCU->getUniqueID()));
2110
2111    if (Asm->isVerbose()) Asm->OutStreamer.AddComment("DWARF Version");
2112    Asm->EmitInt16(dwarf::DWARF_VERSION);
2113
2114    Asm->OutStreamer.AddComment("Offset of Compilation Unit Info");
2115    const MCSection *ISec = Asm->getObjFileLowering().getDwarfInfoSection();
2116    Asm->EmitSectionOffset(Asm->GetTempSymbol(ISec->getLabelBeginName(),
2117                                              TheCU->getUniqueID()),
2118                           DwarfInfoSectionSym);
2119
2120    Asm->OutStreamer.AddComment("Compilation Unit Length");
2121    Asm->EmitLabelDifference(Asm->GetTempSymbol(ISec->getLabelEndName(),
2122                                                TheCU->getUniqueID()),
2123                             Asm->GetTempSymbol(ISec->getLabelBeginName(),
2124                                                TheCU->getUniqueID()),
2125                             4);
2126
2127    const StringMap<DIE*> &Globals = TheCU->getGlobalTypes();
2128    for (StringMap<DIE*>::const_iterator
2129           GI = Globals.begin(), GE = Globals.end(); GI != GE; ++GI) {
2130      const char *Name = GI->getKeyData();
2131      DIE *Entity = GI->second;
2132
2133      if (Asm->isVerbose()) Asm->OutStreamer.AddComment("DIE offset");
2134      Asm->EmitInt32(Entity->getOffset());
2135
2136      if (Asm->isVerbose()) Asm->OutStreamer.AddComment("External Name");
2137      // Emit the name with a terminating null byte.
2138      Asm->OutStreamer.EmitBytes(StringRef(Name, GI->getKeyLength()+1));
2139    }
2140
2141    Asm->OutStreamer.AddComment("End Mark");
2142    Asm->EmitInt32(0);
2143    Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("pubtypes_end",
2144                                                  TheCU->getUniqueID()));
2145  }
2146}
2147
2148// Emit strings into a string section.
2149void DwarfUnits::emitStrings(const MCSection *StrSection,
2150                             const MCSection *OffsetSection = NULL,
2151                             const MCSymbol *StrSecSym = NULL) {
2152
2153  if (StringPool.empty()) return;
2154
2155  // Start the dwarf str section.
2156  Asm->OutStreamer.SwitchSection(StrSection);
2157
2158  // Get all of the string pool entries and put them in an array by their ID so
2159  // we can sort them.
2160  SmallVector<std::pair<unsigned,
2161                 StringMapEntry<std::pair<MCSymbol*, unsigned> >*>, 64> Entries;
2162
2163  for (StringMap<std::pair<MCSymbol*, unsigned> >::iterator
2164         I = StringPool.begin(), E = StringPool.end();
2165       I != E; ++I)
2166    Entries.push_back(std::make_pair(I->second.second, &*I));
2167
2168  array_pod_sort(Entries.begin(), Entries.end());
2169
2170  for (unsigned i = 0, e = Entries.size(); i != e; ++i) {
2171    // Emit a label for reference from debug information entries.
2172    Asm->OutStreamer.EmitLabel(Entries[i].second->getValue().first);
2173
2174    // Emit the string itself with a terminating null byte.
2175    Asm->OutStreamer.EmitBytes(StringRef(Entries[i].second->getKeyData(),
2176                                         Entries[i].second->getKeyLength()+1));
2177  }
2178
2179  // If we've got an offset section go ahead and emit that now as well.
2180  if (OffsetSection) {
2181    Asm->OutStreamer.SwitchSection(OffsetSection);
2182    unsigned offset = 0;
2183    unsigned size = 4; // FIXME: DWARF64 is 8.
2184    for (unsigned i = 0, e = Entries.size(); i != e; ++i) {
2185      Asm->OutStreamer.EmitIntValue(offset, size);
2186      offset += Entries[i].second->getKeyLength() + 1;
2187    }
2188  }
2189}
2190
2191// Emit strings into a string section.
2192void DwarfUnits::emitAddresses(const MCSection *AddrSection) {
2193
2194  if (AddressPool.empty()) return;
2195
2196  // Start the dwarf addr section.
2197  Asm->OutStreamer.SwitchSection(AddrSection);
2198
2199  // Get all of the string pool entries and put them in an array by their ID so
2200  // we can sort them.
2201  SmallVector<std::pair<unsigned,
2202                        std::pair<MCSymbol*, unsigned>* >, 64> Entries;
2203
2204  for (DenseMap<MCSymbol*, std::pair<MCSymbol*, unsigned> >::iterator
2205         I = AddressPool.begin(), E = AddressPool.end();
2206       I != E; ++I)
2207    Entries.push_back(std::make_pair(I->second.second, &(I->second)));
2208
2209  array_pod_sort(Entries.begin(), Entries.end());
2210
2211  for (unsigned i = 0, e = Entries.size(); i != e; ++i) {
2212    // Emit a label for reference from debug information entries.
2213    MCSymbol *Sym = Entries[i].second->first;
2214    if (Sym)
2215      Asm->EmitLabelReference(Entries[i].second->first,
2216                              Asm->getDataLayout().getPointerSize());
2217    else
2218      Asm->OutStreamer.EmitIntValue(0, Asm->getDataLayout().getPointerSize());
2219  }
2220
2221}
2222
2223// Emit visible names into a debug str section.
2224void DwarfDebug::emitDebugStr() {
2225  DwarfUnits &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
2226  Holder.emitStrings(Asm->getObjFileLowering().getDwarfStrSection());
2227}
2228
2229// Emit visible names into a debug loc section.
2230void DwarfDebug::emitDebugLoc() {
2231  if (DotDebugLocEntries.empty())
2232    return;
2233
2234  for (SmallVector<DotDebugLocEntry, 4>::iterator
2235         I = DotDebugLocEntries.begin(), E = DotDebugLocEntries.end();
2236       I != E; ++I) {
2237    DotDebugLocEntry &Entry = *I;
2238    if (I + 1 != DotDebugLocEntries.end())
2239      Entry.Merge(I+1);
2240  }
2241
2242  // Start the dwarf loc section.
2243  Asm->OutStreamer.SwitchSection(
2244    Asm->getObjFileLowering().getDwarfLocSection());
2245  unsigned char Size = Asm->getDataLayout().getPointerSize();
2246  Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("debug_loc", 0));
2247  unsigned index = 1;
2248  for (SmallVector<DotDebugLocEntry, 4>::iterator
2249         I = DotDebugLocEntries.begin(), E = DotDebugLocEntries.end();
2250       I != E; ++I, ++index) {
2251    DotDebugLocEntry &Entry = *I;
2252    if (Entry.isMerged()) continue;
2253    if (Entry.isEmpty()) {
2254      Asm->OutStreamer.EmitIntValue(0, Size);
2255      Asm->OutStreamer.EmitIntValue(0, Size);
2256      Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("debug_loc", index));
2257    } else {
2258      Asm->OutStreamer.EmitSymbolValue(Entry.Begin, Size);
2259      Asm->OutStreamer.EmitSymbolValue(Entry.End, Size);
2260      DIVariable DV(Entry.Variable);
2261      Asm->OutStreamer.AddComment("Loc expr size");
2262      MCSymbol *begin = Asm->OutStreamer.getContext().CreateTempSymbol();
2263      MCSymbol *end = Asm->OutStreamer.getContext().CreateTempSymbol();
2264      Asm->EmitLabelDifference(end, begin, 2);
2265      Asm->OutStreamer.EmitLabel(begin);
2266      if (Entry.isInt()) {
2267        DIBasicType BTy(DV.getType());
2268        if (BTy.Verify() &&
2269            (BTy.getEncoding()  == dwarf::DW_ATE_signed
2270             || BTy.getEncoding() == dwarf::DW_ATE_signed_char)) {
2271          Asm->OutStreamer.AddComment("DW_OP_consts");
2272          Asm->EmitInt8(dwarf::DW_OP_consts);
2273          Asm->EmitSLEB128(Entry.getInt());
2274        } else {
2275          Asm->OutStreamer.AddComment("DW_OP_constu");
2276          Asm->EmitInt8(dwarf::DW_OP_constu);
2277          Asm->EmitULEB128(Entry.getInt());
2278        }
2279      } else if (Entry.isLocation()) {
2280        if (!DV.hasComplexAddress())
2281          // Regular entry.
2282          Asm->EmitDwarfRegOp(Entry.Loc);
2283        else {
2284          // Complex address entry.
2285          unsigned N = DV.getNumAddrElements();
2286          unsigned i = 0;
2287          if (N >= 2 && DV.getAddrElement(0) == DIBuilder::OpPlus) {
2288            if (Entry.Loc.getOffset()) {
2289              i = 2;
2290              Asm->EmitDwarfRegOp(Entry.Loc);
2291              Asm->OutStreamer.AddComment("DW_OP_deref");
2292              Asm->EmitInt8(dwarf::DW_OP_deref);
2293              Asm->OutStreamer.AddComment("DW_OP_plus_uconst");
2294              Asm->EmitInt8(dwarf::DW_OP_plus_uconst);
2295              Asm->EmitSLEB128(DV.getAddrElement(1));
2296            } else {
2297              // If first address element is OpPlus then emit
2298              // DW_OP_breg + Offset instead of DW_OP_reg + Offset.
2299              MachineLocation Loc(Entry.Loc.getReg(), DV.getAddrElement(1));
2300              Asm->EmitDwarfRegOp(Loc);
2301              i = 2;
2302            }
2303          } else {
2304            Asm->EmitDwarfRegOp(Entry.Loc);
2305          }
2306
2307          // Emit remaining complex address elements.
2308          for (; i < N; ++i) {
2309            uint64_t Element = DV.getAddrElement(i);
2310            if (Element == DIBuilder::OpPlus) {
2311              Asm->EmitInt8(dwarf::DW_OP_plus_uconst);
2312              Asm->EmitULEB128(DV.getAddrElement(++i));
2313            } else if (Element == DIBuilder::OpDeref) {
2314              if (!Entry.Loc.isReg())
2315                Asm->EmitInt8(dwarf::DW_OP_deref);
2316            } else
2317              llvm_unreachable("unknown Opcode found in complex address");
2318          }
2319        }
2320      }
2321      // else ... ignore constant fp. There is not any good way to
2322      // to represent them here in dwarf.
2323      Asm->OutStreamer.EmitLabel(end);
2324    }
2325  }
2326}
2327
2328// Emit visible names into a debug aranges section.
2329void DwarfDebug::emitDebugARanges() {
2330  // Start the dwarf aranges section.
2331  Asm->OutStreamer.SwitchSection(
2332                          Asm->getObjFileLowering().getDwarfARangesSection());
2333}
2334
2335// Emit visible names into a debug ranges section.
2336void DwarfDebug::emitDebugRanges() {
2337  // Start the dwarf ranges section.
2338  Asm->OutStreamer.SwitchSection(
2339    Asm->getObjFileLowering().getDwarfRangesSection());
2340  unsigned char Size = Asm->getDataLayout().getPointerSize();
2341  for (SmallVector<const MCSymbol *, 8>::iterator
2342         I = DebugRangeSymbols.begin(), E = DebugRangeSymbols.end();
2343       I != E; ++I) {
2344    if (*I)
2345      Asm->OutStreamer.EmitSymbolValue(const_cast<MCSymbol*>(*I), Size);
2346    else
2347      Asm->OutStreamer.EmitIntValue(0, Size);
2348  }
2349}
2350
2351// Emit visible names into a debug macinfo section.
2352void DwarfDebug::emitDebugMacInfo() {
2353  if (const MCSection *LineInfo =
2354      Asm->getObjFileLowering().getDwarfMacroInfoSection()) {
2355    // Start the dwarf macinfo section.
2356    Asm->OutStreamer.SwitchSection(LineInfo);
2357  }
2358}
2359
2360// Emit inline info using following format.
2361// Section Header:
2362// 1. length of section
2363// 2. Dwarf version number
2364// 3. address size.
2365//
2366// Entries (one "entry" for each function that was inlined):
2367//
2368// 1. offset into __debug_str section for MIPS linkage name, if exists;
2369//   otherwise offset into __debug_str for regular function name.
2370// 2. offset into __debug_str section for regular function name.
2371// 3. an unsigned LEB128 number indicating the number of distinct inlining
2372// instances for the function.
2373//
2374// The rest of the entry consists of a {die_offset, low_pc} pair for each
2375// inlined instance; the die_offset points to the inlined_subroutine die in the
2376// __debug_info section, and the low_pc is the starting address for the
2377// inlining instance.
2378void DwarfDebug::emitDebugInlineInfo() {
2379  if (!Asm->MAI->doesDwarfUseInlineInfoSection())
2380    return;
2381
2382  if (!FirstCU)
2383    return;
2384
2385  Asm->OutStreamer.SwitchSection(
2386                        Asm->getObjFileLowering().getDwarfDebugInlineSection());
2387
2388  Asm->OutStreamer.AddComment("Length of Debug Inlined Information Entry");
2389  Asm->EmitLabelDifference(Asm->GetTempSymbol("debug_inlined_end", 1),
2390                           Asm->GetTempSymbol("debug_inlined_begin", 1), 4);
2391
2392  Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("debug_inlined_begin", 1));
2393
2394  Asm->OutStreamer.AddComment("Dwarf Version");
2395  Asm->EmitInt16(dwarf::DWARF_VERSION);
2396  Asm->OutStreamer.AddComment("Address Size (in bytes)");
2397  Asm->EmitInt8(Asm->getDataLayout().getPointerSize());
2398
2399  for (SmallVector<const MDNode *, 4>::iterator I = InlinedSPNodes.begin(),
2400         E = InlinedSPNodes.end(); I != E; ++I) {
2401
2402    const MDNode *Node = *I;
2403    DenseMap<const MDNode *, SmallVector<InlineInfoLabels, 4> >::iterator II
2404      = InlineInfo.find(Node);
2405    SmallVector<InlineInfoLabels, 4> &Labels = II->second;
2406    DISubprogram SP(Node);
2407    StringRef LName = SP.getLinkageName();
2408    StringRef Name = SP.getName();
2409
2410    Asm->OutStreamer.AddComment("MIPS linkage name");
2411    if (LName.empty())
2412      Asm->EmitSectionOffset(InfoHolder.getStringPoolEntry(Name),
2413                             DwarfStrSectionSym);
2414    else
2415      Asm->EmitSectionOffset(InfoHolder
2416                             .getStringPoolEntry(getRealLinkageName(LName)),
2417                             DwarfStrSectionSym);
2418
2419    Asm->OutStreamer.AddComment("Function name");
2420    Asm->EmitSectionOffset(InfoHolder.getStringPoolEntry(Name),
2421                           DwarfStrSectionSym);
2422    Asm->EmitULEB128(Labels.size(), "Inline count");
2423
2424    for (SmallVector<InlineInfoLabels, 4>::iterator LI = Labels.begin(),
2425           LE = Labels.end(); LI != LE; ++LI) {
2426      if (Asm->isVerbose()) Asm->OutStreamer.AddComment("DIE offset");
2427      Asm->EmitInt32(LI->second->getOffset());
2428
2429      if (Asm->isVerbose()) Asm->OutStreamer.AddComment("low_pc");
2430      Asm->OutStreamer.EmitSymbolValue(LI->first,
2431                                       Asm->getDataLayout().getPointerSize());
2432    }
2433  }
2434
2435  Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("debug_inlined_end", 1));
2436}
2437
2438// DWARF5 Experimental Separate Dwarf emitters.
2439
2440// This DIE has the following attributes: DW_AT_comp_dir, DW_AT_stmt_list,
2441// DW_AT_low_pc, DW_AT_high_pc, DW_AT_ranges, DW_AT_dwo_name, DW_AT_dwo_id,
2442// DW_AT_ranges_base, DW_AT_addr_base. If DW_AT_ranges is present,
2443// DW_AT_low_pc and DW_AT_high_pc are not used, and vice versa.
2444CompileUnit *DwarfDebug::constructSkeletonCU(const MDNode *N) {
2445  DICompileUnit DIUnit(N);
2446  CompilationDir = DIUnit.getDirectory();
2447
2448  DIE *Die = new DIE(dwarf::DW_TAG_compile_unit);
2449  CompileUnit *NewCU = new CompileUnit(GlobalCUIndexCount++,
2450                                       DIUnit.getLanguage(), Die, Asm,
2451                                       this, &SkeletonHolder);
2452
2453  SmallString<16> T(DIUnit.getFilename());
2454  sys::path::replace_extension(T, ".dwo");
2455  StringRef FN = sys::path::filename(T);
2456  NewCU->addLocalString(Die, dwarf::DW_AT_GNU_dwo_name, FN);
2457
2458  // This should be a unique identifier when we want to build .dwp files.
2459  NewCU->addUInt(Die, dwarf::DW_AT_GNU_dwo_id, dwarf::DW_FORM_data8, 0);
2460
2461  // FIXME: The addr base should be relative for each compile unit, however,
2462  // this one is going to be 0 anyhow.
2463  NewCU->addUInt(Die, dwarf::DW_AT_GNU_addr_base, dwarf::DW_FORM_sec_offset, 0);
2464
2465  // 2.17.1 requires that we use DW_AT_low_pc for a single entry point
2466  // into an entity. We're using 0, or a NULL label for this.
2467  NewCU->addUInt(Die, dwarf::DW_AT_low_pc, dwarf::DW_FORM_addr, 0);
2468
2469  // DW_AT_stmt_list is a offset of line number information for this
2470  // compile unit in debug_line section.
2471  if (Asm->MAI->doesDwarfUseRelocationsAcrossSections())
2472    NewCU->addLabel(Die, dwarf::DW_AT_stmt_list, dwarf::DW_FORM_sec_offset,
2473                    Asm->GetTempSymbol("section_line"));
2474  else
2475    NewCU->addUInt(Die, dwarf::DW_AT_stmt_list, dwarf::DW_FORM_sec_offset, 0);
2476
2477  if (!CompilationDir.empty())
2478    NewCU->addLocalString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
2479
2480  SkeletonHolder.addUnit(NewCU);
2481
2482  return NewCU;
2483}
2484
2485void DwarfDebug::emitSkeletonCU(const MCSection *Section) {
2486  Asm->OutStreamer.SwitchSection(Section);
2487  DIE *Die = SkeletonCU->getCUDie();
2488
2489  // Emit the compile units header.
2490  Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol(Section->getLabelBeginName(),
2491                                                SkeletonCU->getUniqueID()));
2492
2493  // Emit size of content not including length itself
2494  unsigned ContentSize = Die->getSize() +
2495    sizeof(int16_t) + // DWARF version number
2496    sizeof(int32_t) + // Offset Into Abbrev. Section
2497    sizeof(int8_t);   // Pointer Size (in bytes)
2498
2499  Asm->OutStreamer.AddComment("Length of Compilation Unit Info");
2500  Asm->EmitInt32(ContentSize);
2501  Asm->OutStreamer.AddComment("DWARF version number");
2502  Asm->EmitInt16(dwarf::DWARF_VERSION);
2503  Asm->OutStreamer.AddComment("Offset Into Abbrev. Section");
2504
2505  const MCSection *ASec = Asm->getObjFileLowering().getDwarfAbbrevSection();
2506  Asm->EmitSectionOffset(Asm->GetTempSymbol(ASec->getLabelBeginName()),
2507                         DwarfAbbrevSectionSym);
2508  Asm->OutStreamer.AddComment("Address Size (in bytes)");
2509  Asm->EmitInt8(Asm->getDataLayout().getPointerSize());
2510
2511  emitDIE(Die, &SkeletonAbbrevs);
2512  Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol(Section->getLabelEndName(),
2513                                                SkeletonCU->getUniqueID()));
2514}
2515
2516void DwarfDebug::emitSkeletonAbbrevs(const MCSection *Section) {
2517  assert(useSplitDwarf() && "No split dwarf debug info?");
2518  emitAbbrevs(Section, &SkeletonAbbrevs);
2519}
2520
2521// Emit the .debug_info.dwo section for separated dwarf. This contains the
2522// compile units that would normally be in debug_info.
2523void DwarfDebug::emitDebugInfoDWO() {
2524  assert(useSplitDwarf() && "No split dwarf debug info?");
2525  InfoHolder.emitUnits(this, Asm->getObjFileLowering().getDwarfInfoDWOSection(),
2526                       Asm->getObjFileLowering().getDwarfAbbrevDWOSection(),
2527                       DwarfAbbrevDWOSectionSym);
2528}
2529
2530// Emit the .debug_abbrev.dwo section for separated dwarf. This contains the
2531// abbreviations for the .debug_info.dwo section.
2532void DwarfDebug::emitDebugAbbrevDWO() {
2533  assert(useSplitDwarf() && "No split dwarf?");
2534  emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevDWOSection(),
2535              &Abbreviations);
2536}
2537
2538// Emit the .debug_str.dwo section for separated dwarf. This contains the
2539// string section and is identical in format to traditional .debug_str
2540// sections.
2541void DwarfDebug::emitDebugStrDWO() {
2542  assert(useSplitDwarf() && "No split dwarf?");
2543  const MCSection *OffSec = Asm->getObjFileLowering()
2544                            .getDwarfStrOffDWOSection();
2545  const MCSymbol *StrSym = DwarfStrSectionSym;
2546  InfoHolder.emitStrings(Asm->getObjFileLowering().getDwarfStrDWOSection(),
2547                         OffSec, StrSym);
2548}
2549