1 //===-- llvm/CodeGen/DwarfDebug.cpp - Dwarf Debug Framework ---------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file contains support for writing dwarf debug info into asm files.
12 //===----------------------------------------------------------------------===//
14 #include "ByteStreamer.h"
15 #include "DwarfDebug.h"
18 #include "DwarfUnit.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/IR/Constants.h"
26 #include "llvm/IR/DIBuilder.h"
27 #include "llvm/IR/DataLayout.h"
28 #include "llvm/IR/DebugInfo.h"
29 #include "llvm/IR/Instructions.h"
30 #include "llvm/IR/Module.h"
31 #include "llvm/IR/ValueHandle.h"
32 #include "llvm/MC/MCAsmInfo.h"
33 #include "llvm/MC/MCSection.h"
34 #include "llvm/MC/MCStreamer.h"
35 #include "llvm/MC/MCSymbol.h"
36 #include "llvm/Support/CommandLine.h"
37 #include "llvm/Support/Debug.h"
38 #include "llvm/Support/Dwarf.h"
39 #include "llvm/Support/ErrorHandling.h"
40 #include "llvm/Support/FormattedStream.h"
41 #include "llvm/Support/LEB128.h"
42 #include "llvm/Support/MD5.h"
43 #include "llvm/Support/Path.h"
44 #include "llvm/Support/Timer.h"
45 #include "llvm/Target/TargetFrameLowering.h"
46 #include "llvm/Target/TargetLoweringObjectFile.h"
47 #include "llvm/Target/TargetMachine.h"
48 #include "llvm/Target/TargetOptions.h"
49 #include "llvm/Target/TargetRegisterInfo.h"
52 #define DEBUG_TYPE "dwarfdebug"
55 DisableDebugInfoPrinting("disable-debug-info-print", cl::Hidden,
56 cl::desc("Disable debug info printing"));
58 static cl::opt<bool> UnknownLocations(
59 "use-unknown-locations", cl::Hidden,
60 cl::desc("Make an absence of debug location information explicit."),
64 GenerateGnuPubSections("generate-gnu-dwarf-pub-sections", cl::Hidden,
65 cl::desc("Generate GNU-style pubnames and pubtypes"),
68 static cl::opt<bool> GenerateARangeSection("generate-arange-section",
70 cl::desc("Generate dwarf aranges"),
74 enum DefaultOnOff { Default, Enable, Disable };
77 static cl::opt<DefaultOnOff>
78 DwarfAccelTables("dwarf-accel-tables", cl::Hidden,
79 cl::desc("Output prototype dwarf accelerator tables."),
80 cl::values(clEnumVal(Default, "Default for platform"),
81 clEnumVal(Enable, "Enabled"),
82 clEnumVal(Disable, "Disabled"), clEnumValEnd),
85 static cl::opt<DefaultOnOff>
86 SplitDwarf("split-dwarf", cl::Hidden,
87 cl::desc("Output DWARF5 split debug info."),
88 cl::values(clEnumVal(Default, "Default for platform"),
89 clEnumVal(Enable, "Enabled"),
90 clEnumVal(Disable, "Disabled"), clEnumValEnd),
93 static cl::opt<DefaultOnOff>
94 DwarfPubSections("generate-dwarf-pub-sections", cl::Hidden,
95 cl::desc("Generate DWARF pubnames and pubtypes sections"),
96 cl::values(clEnumVal(Default, "Default for platform"),
97 clEnumVal(Enable, "Enabled"),
98 clEnumVal(Disable, "Disabled"), clEnumValEnd),
101 static cl::opt<unsigned>
102 DwarfVersionNumber("dwarf-version", cl::Hidden,
103 cl::desc("Generate DWARF for dwarf version."), cl::init(0));
105 static const char *const DWARFGroupName = "DWARF Emission";
106 static const char *const DbgTimerName = "DWARF Debug Writer";
108 //===----------------------------------------------------------------------===//
110 /// resolve - Look in the DwarfDebug map for the MDNode that
111 /// corresponds to the reference.
112 template <typename T> T DbgVariable::resolve(DIRef<T> Ref) const {
113 return DD->resolve(Ref);
116 bool DbgVariable::isBlockByrefVariable() const {
117 assert(Var.isVariable() && "Invalid complex DbgVariable!");
118 return Var.isBlockByrefVariable(DD->getTypeIdentifierMap());
121 DIType DbgVariable::getType() const {
122 DIType Ty = Var.getType().resolve(DD->getTypeIdentifierMap());
123 // FIXME: isBlockByrefVariable should be reformulated in terms of complex
124 // addresses instead.
125 if (Var.isBlockByrefVariable(DD->getTypeIdentifierMap())) {
126 /* Byref variables, in Blocks, are declared by the programmer as
127 "SomeType VarName;", but the compiler creates a
128 __Block_byref_x_VarName struct, and gives the variable VarName
129 either the struct, or a pointer to the struct, as its type. This
130 is necessary for various behind-the-scenes things the compiler
131 needs to do with by-reference variables in blocks.
133 However, as far as the original *programmer* is concerned, the
134 variable should still have type 'SomeType', as originally declared.
136 The following function dives into the __Block_byref_x_VarName
137 struct to find the original type of the variable. This will be
138 passed back to the code generating the type for the Debug
139 Information Entry for the variable 'VarName'. 'VarName' will then
140 have the original type 'SomeType' in its debug information.
142 The original type 'SomeType' will be the type of the field named
143 'VarName' inside the __Block_byref_x_VarName struct.
145 NOTE: In order for this to not completely fail on the debugger
146 side, the Debug Information Entry for the variable VarName needs to
147 have a DW_AT_location that tells the debugger how to unwind through
148 the pointers and __Block_byref_x_VarName struct to find the actual
149 value of the variable. The function addBlockByrefType does this. */
151 uint16_t tag = Ty.getTag();
153 if (tag == dwarf::DW_TAG_pointer_type)
154 subType = resolve(DIDerivedType(Ty).getTypeDerivedFrom());
156 DIArray Elements = DICompositeType(subType).getTypeArray();
157 for (unsigned i = 0, N = Elements.getNumElements(); i < N; ++i) {
158 DIDerivedType DT(Elements.getElement(i));
159 if (getName() == DT.getName())
160 return (resolve(DT.getTypeDerivedFrom()));
166 static LLVM_CONSTEXPR DwarfAccelTable::Atom TypeAtoms[] = {
167 DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset, dwarf::DW_FORM_data4),
168 DwarfAccelTable::Atom(dwarf::DW_ATOM_die_tag, dwarf::DW_FORM_data2),
169 DwarfAccelTable::Atom(dwarf::DW_ATOM_type_flags, dwarf::DW_FORM_data1)};
171 DwarfDebug::DwarfDebug(AsmPrinter *A, Module *M)
172 : Asm(A), MMI(Asm->MMI), FirstCU(nullptr), PrevLabel(nullptr),
173 GlobalRangeCount(0), InfoHolder(A, "info_string", DIEValueAllocator),
174 UsedNonDefaultText(false),
175 SkeletonHolder(A, "skel_string", DIEValueAllocator),
176 AccelNames(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
177 dwarf::DW_FORM_data4)),
178 AccelObjC(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
179 dwarf::DW_FORM_data4)),
180 AccelNamespace(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
181 dwarf::DW_FORM_data4)),
182 AccelTypes(TypeAtoms) {
184 DwarfInfoSectionSym = DwarfAbbrevSectionSym = DwarfStrSectionSym = nullptr;
185 DwarfDebugRangeSectionSym = DwarfDebugLocSectionSym = nullptr;
186 DwarfLineSectionSym = nullptr;
187 DwarfAddrSectionSym = nullptr;
188 DwarfAbbrevDWOSectionSym = DwarfStrDWOSectionSym = nullptr;
189 FunctionBeginSym = FunctionEndSym = nullptr;
193 // Turn on accelerator tables for Darwin by default, pubnames by
194 // default for non-Darwin, and handle split dwarf.
195 bool IsDarwin = Triple(A->getTargetTriple()).isOSDarwin();
197 if (DwarfAccelTables == Default)
198 HasDwarfAccelTables = IsDarwin;
200 HasDwarfAccelTables = DwarfAccelTables == Enable;
202 if (SplitDwarf == Default)
203 HasSplitDwarf = false;
205 HasSplitDwarf = SplitDwarf == Enable;
207 if (DwarfPubSections == Default)
208 HasDwarfPubSections = !IsDarwin;
210 HasDwarfPubSections = DwarfPubSections == Enable;
212 DwarfVersion = DwarfVersionNumber ? DwarfVersionNumber
213 : MMI->getModule()->getDwarfVersion();
216 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
221 // Define out of line so we don't have to include DwarfUnit.h in DwarfDebug.h.
222 DwarfDebug::~DwarfDebug() { }
224 // Switch to the specified MCSection and emit an assembler
225 // temporary label to it if SymbolStem is specified.
226 static MCSymbol *emitSectionSym(AsmPrinter *Asm, const MCSection *Section,
227 const char *SymbolStem = nullptr) {
228 Asm->OutStreamer.SwitchSection(Section);
232 MCSymbol *TmpSym = Asm->GetTempSymbol(SymbolStem);
233 Asm->OutStreamer.EmitLabel(TmpSym);
237 static bool isObjCClass(StringRef Name) {
238 return Name.startswith("+") || Name.startswith("-");
241 static bool hasObjCCategory(StringRef Name) {
242 if (!isObjCClass(Name))
245 return Name.find(") ") != StringRef::npos;
248 static void getObjCClassCategory(StringRef In, StringRef &Class,
249 StringRef &Category) {
250 if (!hasObjCCategory(In)) {
251 Class = In.slice(In.find('[') + 1, In.find(' '));
256 Class = In.slice(In.find('[') + 1, In.find('('));
257 Category = In.slice(In.find('[') + 1, In.find(' '));
261 static StringRef getObjCMethodName(StringRef In) {
262 return In.slice(In.find(' ') + 1, In.find(']'));
265 // Helper for sorting sections into a stable output order.
266 static bool SectionSort(const MCSection *A, const MCSection *B) {
267 std::string LA = (A ? A->getLabelBeginName() : "");
268 std::string LB = (B ? B->getLabelBeginName() : "");
272 // Add the various names to the Dwarf accelerator table names.
273 // TODO: Determine whether or not we should add names for programs
274 // that do not have a DW_AT_name or DW_AT_linkage_name field - this
275 // is only slightly different than the lookup of non-standard ObjC names.
276 void DwarfDebug::addSubprogramNames(DISubprogram SP, DIE &Die) {
277 if (!SP.isDefinition())
279 addAccelName(SP.getName(), Die);
281 // If the linkage name is different than the name, go ahead and output
282 // that as well into the name table.
283 if (SP.getLinkageName() != "" && SP.getName() != SP.getLinkageName())
284 addAccelName(SP.getLinkageName(), Die);
286 // If this is an Objective-C selector name add it to the ObjC accelerator
288 if (isObjCClass(SP.getName())) {
289 StringRef Class, Category;
290 getObjCClassCategory(SP.getName(), Class, Category);
291 addAccelObjC(Class, Die);
293 addAccelObjC(Category, Die);
294 // Also add the base method name to the name table.
295 addAccelName(getObjCMethodName(SP.getName()), Die);
299 /// isSubprogramContext - Return true if Context is either a subprogram
300 /// or another context nested inside a subprogram.
301 bool DwarfDebug::isSubprogramContext(const MDNode *Context) {
304 DIDescriptor D(Context);
305 if (D.isSubprogram())
308 return isSubprogramContext(resolve(DIType(Context).getContext()));
312 // Find DIE for the given subprogram and attach appropriate DW_AT_low_pc
313 // and DW_AT_high_pc attributes. If there are global variables in this
314 // scope then create and insert DIEs for these variables.
315 DIE &DwarfDebug::updateSubprogramScopeDIE(DwarfCompileUnit &SPCU,
317 DIE *SPDie = SPCU.getDIE(SP);
319 assert(SPDie && "Unable to find subprogram DIE!");
321 // If we're updating an abstract DIE, then we will be adding the children and
322 // object pointer later on. But what we don't want to do is process the
323 // concrete DIE twice.
324 if (DIE *AbsSPDIE = AbstractSPDies.lookup(SP)) {
325 // Pick up abstract subprogram DIE.
326 SPDie = &SPCU.createAndAddDIE(dwarf::DW_TAG_subprogram, SPCU.getUnitDie());
327 SPCU.addDIEEntry(*SPDie, dwarf::DW_AT_abstract_origin, *AbsSPDIE);
329 DISubprogram SPDecl = SP.getFunctionDeclaration();
330 if (!SPDecl.isSubprogram()) {
331 // There is not any need to generate specification DIE for a function
332 // defined at compile unit level. If a function is defined inside another
333 // function then gdb prefers the definition at top level and but does not
334 // expect specification DIE in parent function. So avoid creating
335 // specification DIE for a function defined inside a function.
336 DIScope SPContext = resolve(SP.getContext());
337 if (SP.isDefinition() && !SPContext.isCompileUnit() &&
338 !SPContext.isFile() && !isSubprogramContext(SPContext)) {
339 SPCU.addFlag(*SPDie, dwarf::DW_AT_declaration);
342 DICompositeType SPTy = SP.getType();
343 DIArray Args = SPTy.getTypeArray();
344 uint16_t SPTag = SPTy.getTag();
345 if (SPTag == dwarf::DW_TAG_subroutine_type)
346 SPCU.constructSubprogramArguments(*SPDie, Args);
347 DIE *SPDeclDie = SPDie;
349 &SPCU.createAndAddDIE(dwarf::DW_TAG_subprogram, SPCU.getUnitDie());
350 SPCU.addDIEEntry(*SPDie, dwarf::DW_AT_specification, *SPDeclDie);
355 attachLowHighPC(SPCU, *SPDie, FunctionBeginSym, FunctionEndSym);
357 const TargetRegisterInfo *RI = Asm->TM.getRegisterInfo();
358 MachineLocation Location(RI->getFrameRegister(*Asm->MF));
359 SPCU.addAddress(*SPDie, dwarf::DW_AT_frame_base, Location);
361 // Add name to the name table, we do this here because we're guaranteed
362 // to have concrete versions of our DW_TAG_subprogram nodes.
363 addSubprogramNames(SP, *SPDie);
368 /// Check whether we should create a DIE for the given Scope, return true
369 /// if we don't create a DIE (the corresponding DIE is null).
370 bool DwarfDebug::isLexicalScopeDIENull(LexicalScope *Scope) {
371 if (Scope->isAbstractScope())
374 // We don't create a DIE if there is no Range.
375 const SmallVectorImpl<InsnRange> &Ranges = Scope->getRanges();
379 if (Ranges.size() > 1)
382 // We don't create a DIE if we have a single Range and the end label
384 SmallVectorImpl<InsnRange>::const_iterator RI = Ranges.begin();
385 MCSymbol *End = getLabelAfterInsn(RI->second);
389 static void addSectionLabel(AsmPrinter &Asm, DwarfUnit &U, DIE &D,
390 dwarf::Attribute A, const MCSymbol *L,
391 const MCSymbol *Sec) {
392 if (Asm.MAI->doesDwarfUseRelocationsAcrossSections())
393 U.addSectionLabel(D, A, L);
395 U.addSectionDelta(D, A, L, Sec);
398 void DwarfDebug::addScopeRangeList(DwarfCompileUnit &TheCU, DIE &ScopeDIE,
399 const SmallVectorImpl<InsnRange> &Range) {
400 // Emit offset in .debug_range as a relocatable label. emitDIE will handle
401 // emitting it appropriately.
402 MCSymbol *RangeSym = Asm->GetTempSymbol("debug_ranges", GlobalRangeCount++);
404 // Under fission, ranges are specified by constant offsets relative to the
405 // CU's DW_AT_GNU_ranges_base.
407 TheCU.addSectionDelta(ScopeDIE, dwarf::DW_AT_ranges, RangeSym,
408 DwarfDebugRangeSectionSym);
410 addSectionLabel(*Asm, TheCU, ScopeDIE, dwarf::DW_AT_ranges, RangeSym,
411 DwarfDebugRangeSectionSym);
413 RangeSpanList List(RangeSym);
414 for (const InsnRange &R : Range) {
415 RangeSpan Span(getLabelBeforeInsn(R.first), getLabelAfterInsn(R.second));
416 List.addRange(std::move(Span));
419 // Add the range list to the set of ranges to be emitted.
420 TheCU.addRangeList(std::move(List));
423 // Construct new DW_TAG_lexical_block for this scope and attach
424 // DW_AT_low_pc/DW_AT_high_pc labels.
426 DwarfDebug::constructLexicalScopeDIE(DwarfCompileUnit &TheCU,
427 LexicalScope *Scope) {
428 if (isLexicalScopeDIENull(Scope))
431 auto ScopeDIE = make_unique<DIE>(dwarf::DW_TAG_lexical_block);
432 if (Scope->isAbstractScope())
435 const SmallVectorImpl<InsnRange> &ScopeRanges = Scope->getRanges();
437 // If we have multiple ranges, emit them into the range section.
438 if (ScopeRanges.size() > 1) {
439 addScopeRangeList(TheCU, *ScopeDIE, ScopeRanges);
443 // Construct the address range for this DIE.
444 SmallVectorImpl<InsnRange>::const_iterator RI = ScopeRanges.begin();
445 MCSymbol *Start = getLabelBeforeInsn(RI->first);
446 MCSymbol *End = getLabelAfterInsn(RI->second);
447 assert(End && "End label should not be null!");
449 assert(Start->isDefined() && "Invalid starting label for an inlined scope!");
450 assert(End->isDefined() && "Invalid end label for an inlined scope!");
452 attachLowHighPC(TheCU, *ScopeDIE, Start, End);
457 // This scope represents inlined body of a function. Construct DIE to
458 // represent this concrete inlined copy of the function.
460 DwarfDebug::constructInlinedScopeDIE(DwarfCompileUnit &TheCU,
461 LexicalScope *Scope) {
462 const SmallVectorImpl<InsnRange> &ScopeRanges = Scope->getRanges();
463 assert(!ScopeRanges.empty() &&
464 "LexicalScope does not have instruction markers!");
466 if (!Scope->getScopeNode())
468 DIScope DS(Scope->getScopeNode());
469 DISubprogram InlinedSP = getDISubprogram(DS);
470 DIE *OriginDIE = TheCU.getDIE(InlinedSP);
472 DEBUG(dbgs() << "Unable to find original DIE for an inlined subprogram.");
476 auto ScopeDIE = make_unique<DIE>(dwarf::DW_TAG_inlined_subroutine);
477 TheCU.addDIEEntry(*ScopeDIE, dwarf::DW_AT_abstract_origin, *OriginDIE);
479 // If we have multiple ranges, emit them into the range section.
480 if (ScopeRanges.size() > 1)
481 addScopeRangeList(TheCU, *ScopeDIE, ScopeRanges);
483 SmallVectorImpl<InsnRange>::const_iterator RI = ScopeRanges.begin();
484 MCSymbol *StartLabel = getLabelBeforeInsn(RI->first);
485 MCSymbol *EndLabel = getLabelAfterInsn(RI->second);
487 if (!StartLabel || !EndLabel)
488 llvm_unreachable("Unexpected Start and End labels for an inlined scope!");
490 assert(StartLabel->isDefined() &&
491 "Invalid starting label for an inlined scope!");
492 assert(EndLabel->isDefined() && "Invalid end label for an inlined scope!");
494 attachLowHighPC(TheCU, *ScopeDIE, StartLabel, EndLabel);
497 InlinedSubprogramDIEs.insert(OriginDIE);
499 // Add the call site information to the DIE.
500 DILocation DL(Scope->getInlinedAt());
501 TheCU.addUInt(*ScopeDIE, dwarf::DW_AT_call_file, None,
502 TheCU.getOrCreateSourceID(DL.getFilename(), DL.getDirectory()));
503 TheCU.addUInt(*ScopeDIE, dwarf::DW_AT_call_line, None, DL.getLineNumber());
505 // Add name to the name table, we do this here because we're guaranteed
506 // to have concrete versions of our DW_TAG_inlined_subprogram nodes.
507 addSubprogramNames(InlinedSP, *ScopeDIE);
512 DIE *DwarfDebug::createScopeChildrenDIE(
513 DwarfCompileUnit &TheCU, LexicalScope *Scope,
514 SmallVectorImpl<std::unique_ptr<DIE>> &Children) {
515 DIE *ObjectPointer = nullptr;
517 // Collect arguments for current function.
518 if (LScopes.isCurrentFunctionScope(Scope)) {
519 for (DbgVariable *ArgDV : CurrentFnArguments)
522 TheCU.constructVariableDIE(*ArgDV, Scope->isAbstractScope()));
523 if (ArgDV->isObjectPointer())
524 ObjectPointer = Children.back().get();
527 // If this is a variadic function, add an unspecified parameter.
528 DISubprogram SP(Scope->getScopeNode());
529 DIArray FnArgs = SP.getType().getTypeArray();
530 if (FnArgs.getElement(FnArgs.getNumElements() - 1)
531 .isUnspecifiedParameter()) {
533 make_unique<DIE>(dwarf::DW_TAG_unspecified_parameters));
537 // Collect lexical scope children first.
538 for (DbgVariable *DV : ScopeVariables.lookup(Scope)) {
540 TheCU.constructVariableDIE(*DV, Scope->isAbstractScope()));
541 if (DV->isObjectPointer())
542 ObjectPointer = Children.back().get();
544 for (LexicalScope *LS : Scope->getChildren())
545 if (std::unique_ptr<DIE> Nested = constructScopeDIE(TheCU, LS))
546 Children.push_back(std::move(Nested));
547 return ObjectPointer;
550 void DwarfDebug::createAndAddScopeChildren(DwarfCompileUnit &TheCU,
552 DISubprogram Sub, DIE &ScopeDIE) {
553 // We create children when the scope DIE is not null.
554 SmallVector<std::unique_ptr<DIE>, 8> Children;
555 if (DIE *ObjectPointer = createScopeChildrenDIE(TheCU, Scope, Children))
556 // The declaration will have the object_pointer, otherwise put it on the
557 // definition. This happens with ObjC blocks that have object_pointer on
558 // non-member functions.
559 if (!Sub.getFunctionDeclaration())
560 TheCU.addDIEEntry(ScopeDIE, dwarf::DW_AT_object_pointer, *ObjectPointer);
563 for (auto &I : Children)
564 ScopeDIE.addChild(std::move(I));
567 void DwarfDebug::constructAbstractSubprogramScopeDIE(DwarfCompileUnit &TheCU,
568 LexicalScope *Scope) {
569 assert(Scope && Scope->getScopeNode());
570 assert(Scope->isAbstractScope());
571 assert(!Scope->getInlinedAt());
573 DISubprogram Sub(Scope->getScopeNode());
575 ProcessedSPNodes.insert(Sub);
577 if (DIE *ScopeDIE = TheCU.getDIE(Sub)) {
578 AbstractSPDies.insert(std::make_pair(Sub, ScopeDIE));
579 createAndAddScopeChildren(TheCU, Scope, Sub, *ScopeDIE);
583 DIE &DwarfDebug::constructSubprogramScopeDIE(DwarfCompileUnit &TheCU,
584 LexicalScope *Scope) {
585 assert(Scope && Scope->getScopeNode());
586 assert(!Scope->getInlinedAt());
587 assert(!Scope->isAbstractScope());
588 assert(DIScope(Scope->getScopeNode()).isSubprogram());
590 DISubprogram Sub(Scope->getScopeNode());
592 ProcessedSPNodes.insert(Sub);
594 DIE &ScopeDIE = updateSubprogramScopeDIE(TheCU, Sub);
596 createAndAddScopeChildren(TheCU, Scope, Sub, ScopeDIE);
601 // Construct a DIE for this scope.
602 std::unique_ptr<DIE> DwarfDebug::constructScopeDIE(DwarfCompileUnit &TheCU,
603 LexicalScope *Scope) {
604 if (!Scope || !Scope->getScopeNode())
607 DIScope DS(Scope->getScopeNode());
609 assert((Scope->getInlinedAt() || !DS.isSubprogram()) &&
610 "Only handle inlined subprograms here, use "
611 "constructSubprogramScopeDIE for non-inlined "
614 SmallVector<std::unique_ptr<DIE>, 8> Children;
616 // We try to create the scope DIE first, then the children DIEs. This will
617 // avoid creating un-used children then removing them later when we find out
618 // the scope DIE is null.
619 std::unique_ptr<DIE> ScopeDIE;
620 if (Scope->getInlinedAt()) {
621 ScopeDIE = constructInlinedScopeDIE(TheCU, Scope);
624 // We create children when the scope DIE is not null.
625 createScopeChildrenDIE(TheCU, Scope, Children);
627 // Early exit when we know the scope DIE is going to be null.
628 if (isLexicalScopeDIENull(Scope))
631 // We create children here when we know the scope DIE is not going to be
632 // null and the children will be added to the scope DIE.
633 createScopeChildrenDIE(TheCU, Scope, Children);
635 // There is no need to emit empty lexical block DIE.
636 std::pair<ImportedEntityMap::const_iterator,
637 ImportedEntityMap::const_iterator> Range =
638 std::equal_range(ScopesWithImportedEntities.begin(),
639 ScopesWithImportedEntities.end(),
640 std::pair<const MDNode *, const MDNode *>(DS, nullptr),
642 if (Children.empty() && Range.first == Range.second)
644 ScopeDIE = constructLexicalScopeDIE(TheCU, Scope);
645 assert(ScopeDIE && "Scope DIE should not be null.");
646 for (ImportedEntityMap::const_iterator i = Range.first; i != Range.second;
648 constructImportedEntityDIE(TheCU, i->second, *ScopeDIE);
652 for (auto &I : Children)
653 ScopeDIE->addChild(std::move(I));
658 void DwarfDebug::addGnuPubAttributes(DwarfUnit &U, DIE &D) const {
659 if (!GenerateGnuPubSections)
662 U.addFlag(D, dwarf::DW_AT_GNU_pubnames);
665 // Create new DwarfCompileUnit for the given metadata node with tag
666 // DW_TAG_compile_unit.
667 DwarfCompileUnit &DwarfDebug::constructDwarfCompileUnit(DICompileUnit DIUnit) {
668 StringRef FN = DIUnit.getFilename();
669 CompilationDir = DIUnit.getDirectory();
671 auto OwnedUnit = make_unique<DwarfCompileUnit>(
672 InfoHolder.getUnits().size(), DIUnit, Asm, this, &InfoHolder);
673 DwarfCompileUnit &NewCU = *OwnedUnit;
674 DIE &Die = NewCU.getUnitDie();
675 InfoHolder.addUnit(std::move(OwnedUnit));
677 // LTO with assembly output shares a single line table amongst multiple CUs.
678 // To avoid the compilation directory being ambiguous, let the line table
679 // explicitly describe the directory of all files, never relying on the
680 // compilation directory.
681 if (!Asm->OutStreamer.hasRawTextSupport() || SingleCU)
682 Asm->OutStreamer.getContext().setMCLineTableCompilationDir(
683 NewCU.getUniqueID(), CompilationDir);
685 NewCU.addString(Die, dwarf::DW_AT_producer, DIUnit.getProducer());
686 NewCU.addUInt(Die, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
687 DIUnit.getLanguage());
688 NewCU.addString(Die, dwarf::DW_AT_name, FN);
690 if (!useSplitDwarf()) {
691 NewCU.initStmtList(DwarfLineSectionSym);
693 // If we're using split dwarf the compilation dir is going to be in the
694 // skeleton CU and so we don't need to duplicate it here.
695 if (!CompilationDir.empty())
696 NewCU.addString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
698 addGnuPubAttributes(NewCU, Die);
701 if (DIUnit.isOptimized())
702 NewCU.addFlag(Die, dwarf::DW_AT_APPLE_optimized);
704 StringRef Flags = DIUnit.getFlags();
706 NewCU.addString(Die, dwarf::DW_AT_APPLE_flags, Flags);
708 if (unsigned RVer = DIUnit.getRunTimeVersion())
709 NewCU.addUInt(Die, dwarf::DW_AT_APPLE_major_runtime_vers,
710 dwarf::DW_FORM_data1, RVer);
715 if (useSplitDwarf()) {
716 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoDWOSection(),
717 DwarfInfoDWOSectionSym);
718 NewCU.setSkeleton(constructSkeletonCU(NewCU));
720 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoSection(),
721 DwarfInfoSectionSym);
723 CUMap.insert(std::make_pair(DIUnit, &NewCU));
724 CUDieMap.insert(std::make_pair(&Die, &NewCU));
728 // Construct subprogram DIE.
729 void DwarfDebug::constructSubprogramDIE(DwarfCompileUnit &TheCU,
731 // FIXME: We should only call this routine once, however, during LTO if a
732 // program is defined in multiple CUs we could end up calling it out of
733 // beginModule as we walk the CUs.
735 DwarfCompileUnit *&CURef = SPMap[N];
741 if (!SP.isDefinition())
742 // This is a method declaration which will be handled while constructing
746 DIE &SubprogramDie = *TheCU.getOrCreateSubprogramDIE(SP);
748 // Expose as a global name.
749 TheCU.addGlobalName(SP.getName(), SubprogramDie, resolve(SP.getContext()));
752 void DwarfDebug::constructImportedEntityDIE(DwarfCompileUnit &TheCU,
754 DIImportedEntity Module(N);
755 assert(Module.Verify());
756 if (DIE *D = TheCU.getOrCreateContextDIE(Module.getContext()))
757 constructImportedEntityDIE(TheCU, Module, *D);
760 void DwarfDebug::constructImportedEntityDIE(DwarfCompileUnit &TheCU,
761 const MDNode *N, DIE &Context) {
762 DIImportedEntity Module(N);
763 assert(Module.Verify());
764 return constructImportedEntityDIE(TheCU, Module, Context);
767 void DwarfDebug::constructImportedEntityDIE(DwarfCompileUnit &TheCU,
768 const DIImportedEntity &Module,
770 assert(Module.Verify() &&
771 "Use one of the MDNode * overloads to handle invalid metadata");
772 DIE &IMDie = TheCU.createAndAddDIE(Module.getTag(), Context, Module);
774 DIDescriptor Entity = resolve(Module.getEntity());
775 if (Entity.isNameSpace())
776 EntityDie = TheCU.getOrCreateNameSpace(DINameSpace(Entity));
777 else if (Entity.isSubprogram())
778 EntityDie = TheCU.getOrCreateSubprogramDIE(DISubprogram(Entity));
779 else if (Entity.isType())
780 EntityDie = TheCU.getOrCreateTypeDIE(DIType(Entity));
782 EntityDie = TheCU.getDIE(Entity);
783 TheCU.addSourceLine(IMDie, Module.getLineNumber(),
784 Module.getContext().getFilename(),
785 Module.getContext().getDirectory());
786 TheCU.addDIEEntry(IMDie, dwarf::DW_AT_import, *EntityDie);
787 StringRef Name = Module.getName();
789 TheCU.addString(IMDie, dwarf::DW_AT_name, Name);
792 // Emit all Dwarf sections that should come prior to the content. Create
793 // global DIEs and emit initial debug info sections. This is invoked by
794 // the target AsmPrinter.
795 void DwarfDebug::beginModule() {
796 if (DisableDebugInfoPrinting)
799 const Module *M = MMI->getModule();
801 // If module has named metadata anchors then use them, otherwise scan the
802 // module using debug info finder to collect debug info.
803 NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
806 TypeIdentifierMap = generateDITypeIdentifierMap(CU_Nodes);
808 // Emit initial sections so we can reference labels later.
811 SingleCU = CU_Nodes->getNumOperands() == 1;
813 for (MDNode *N : CU_Nodes->operands()) {
814 DICompileUnit CUNode(N);
815 DwarfCompileUnit &CU = constructDwarfCompileUnit(CUNode);
816 DIArray ImportedEntities = CUNode.getImportedEntities();
817 for (unsigned i = 0, e = ImportedEntities.getNumElements(); i != e; ++i)
818 ScopesWithImportedEntities.push_back(std::make_pair(
819 DIImportedEntity(ImportedEntities.getElement(i)).getContext(),
820 ImportedEntities.getElement(i)));
821 std::sort(ScopesWithImportedEntities.begin(),
822 ScopesWithImportedEntities.end(), less_first());
823 DIArray GVs = CUNode.getGlobalVariables();
824 for (unsigned i = 0, e = GVs.getNumElements(); i != e; ++i)
825 CU.createGlobalVariableDIE(DIGlobalVariable(GVs.getElement(i)));
826 DIArray SPs = CUNode.getSubprograms();
827 for (unsigned i = 0, e = SPs.getNumElements(); i != e; ++i)
828 constructSubprogramDIE(CU, SPs.getElement(i));
829 DIArray EnumTypes = CUNode.getEnumTypes();
830 for (unsigned i = 0, e = EnumTypes.getNumElements(); i != e; ++i)
831 CU.getOrCreateTypeDIE(EnumTypes.getElement(i));
832 DIArray RetainedTypes = CUNode.getRetainedTypes();
833 for (unsigned i = 0, e = RetainedTypes.getNumElements(); i != e; ++i) {
834 DIType Ty(RetainedTypes.getElement(i));
835 // The retained types array by design contains pointers to
836 // MDNodes rather than DIRefs. Unique them here.
837 DIType UniqueTy(resolve(Ty.getRef()));
838 CU.getOrCreateTypeDIE(UniqueTy);
840 // Emit imported_modules last so that the relevant context is already
842 for (unsigned i = 0, e = ImportedEntities.getNumElements(); i != e; ++i)
843 constructImportedEntityDIE(CU, ImportedEntities.getElement(i));
846 // Tell MMI that we have debug info.
847 MMI->setDebugInfoAvailability(true);
849 // Prime section data.
850 SectionMap[Asm->getObjFileLowering().getTextSection()];
853 // Attach DW_AT_inline attribute with inlined subprogram DIEs.
854 void DwarfDebug::computeInlinedDIEs() {
855 // Attach DW_AT_inline attribute with inlined subprogram DIEs.
856 for (DIE *ISP : InlinedSubprogramDIEs)
857 FirstCU->addUInt(*ISP, dwarf::DW_AT_inline, None, dwarf::DW_INL_inlined);
859 for (const auto &AI : AbstractSPDies) {
860 DIE &ISP = *AI.second;
861 if (InlinedSubprogramDIEs.count(&ISP))
863 FirstCU->addUInt(ISP, dwarf::DW_AT_inline, None, dwarf::DW_INL_inlined);
867 // Collect info for variables that were optimized out.
868 void DwarfDebug::collectDeadVariables() {
869 const Module *M = MMI->getModule();
871 if (NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu")) {
872 for (MDNode *N : CU_Nodes->operands()) {
873 DICompileUnit TheCU(N);
874 DIArray Subprograms = TheCU.getSubprograms();
875 for (unsigned i = 0, e = Subprograms.getNumElements(); i != e; ++i) {
876 DISubprogram SP(Subprograms.getElement(i));
877 if (ProcessedSPNodes.count(SP) != 0)
879 if (!SP.isSubprogram())
881 if (!SP.isDefinition())
883 DIArray Variables = SP.getVariables();
884 if (Variables.getNumElements() == 0)
887 // Construct subprogram DIE and add variables DIEs.
888 DwarfCompileUnit *SPCU =
889 static_cast<DwarfCompileUnit *>(CUMap.lookup(TheCU));
890 assert(SPCU && "Unable to find Compile Unit!");
891 // FIXME: See the comment in constructSubprogramDIE about duplicate
893 constructSubprogramDIE(*SPCU, SP);
894 DIE *SPDIE = SPCU->getDIE(SP);
895 for (unsigned vi = 0, ve = Variables.getNumElements(); vi != ve; ++vi) {
896 DIVariable DV(Variables.getElement(vi));
897 if (!DV.isVariable())
899 DbgVariable NewVar(DV, nullptr, this);
900 SPDIE->addChild(SPCU->constructVariableDIE(NewVar, false));
907 void DwarfDebug::finalizeModuleInfo() {
908 // Collect info for variables that were optimized out.
909 collectDeadVariables();
911 // Attach DW_AT_inline attribute with inlined subprogram DIEs.
912 computeInlinedDIEs();
914 // Handle anything that needs to be done on a per-unit basis after
915 // all other generation.
916 for (const auto &TheU : getUnits()) {
917 // Emit DW_AT_containing_type attribute to connect types with their
918 // vtable holding type.
919 TheU->constructContainingTypeDIEs();
921 // Add CU specific attributes if we need to add any.
922 if (TheU->getUnitDie().getTag() == dwarf::DW_TAG_compile_unit) {
923 // If we're splitting the dwarf out now that we've got the entire
924 // CU then add the dwo id to it.
925 DwarfCompileUnit *SkCU =
926 static_cast<DwarfCompileUnit *>(TheU->getSkeleton());
927 if (useSplitDwarf()) {
928 // Emit a unique identifier for this CU.
929 uint64_t ID = DIEHash(Asm).computeCUSignature(TheU->getUnitDie());
930 TheU->addUInt(TheU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
931 dwarf::DW_FORM_data8, ID);
932 SkCU->addUInt(SkCU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
933 dwarf::DW_FORM_data8, ID);
935 // We don't keep track of which addresses are used in which CU so this
936 // is a bit pessimistic under LTO.
937 if (!AddrPool.isEmpty())
938 addSectionLabel(*Asm, *SkCU, SkCU->getUnitDie(),
939 dwarf::DW_AT_GNU_addr_base, DwarfAddrSectionSym,
940 DwarfAddrSectionSym);
941 if (!TheU->getRangeLists().empty())
942 addSectionLabel(*Asm, *SkCU, SkCU->getUnitDie(),
943 dwarf::DW_AT_GNU_ranges_base,
944 DwarfDebugRangeSectionSym, DwarfDebugRangeSectionSym);
947 // If we have code split among multiple sections or non-contiguous
948 // ranges of code then emit a DW_AT_ranges attribute on the unit that will
949 // remain in the .o file, otherwise add a DW_AT_low_pc.
950 // FIXME: We should use ranges allow reordering of code ala
951 // .subsections_via_symbols in mach-o. This would mean turning on
952 // ranges for all subprogram DIEs for mach-o.
953 DwarfCompileUnit &U =
954 SkCU ? *SkCU : static_cast<DwarfCompileUnit &>(*TheU);
955 unsigned NumRanges = TheU->getRanges().size();
958 addSectionLabel(*Asm, U, U.getUnitDie(), dwarf::DW_AT_ranges,
959 Asm->GetTempSymbol("cu_ranges", U.getUniqueID()),
960 DwarfDebugRangeSectionSym);
962 // A DW_AT_low_pc attribute may also be specified in combination with
963 // DW_AT_ranges to specify the default base address for use in
964 // location lists (see Section 2.6.2) and range lists (see Section
966 U.addUInt(U.getUnitDie(), dwarf::DW_AT_low_pc, dwarf::DW_FORM_addr,
969 RangeSpan &Range = TheU->getRanges().back();
970 U.addLocalLabelAddress(U.getUnitDie(), dwarf::DW_AT_low_pc,
972 U.addLabelDelta(U.getUnitDie(), dwarf::DW_AT_high_pc, Range.getEnd(),
979 // Compute DIE offsets and sizes.
980 InfoHolder.computeSizeAndOffsets();
982 SkeletonHolder.computeSizeAndOffsets();
985 void DwarfDebug::endSections() {
986 // Filter labels by section.
987 for (const SymbolCU &SCU : ArangeLabels) {
988 if (SCU.Sym->isInSection()) {
989 // Make a note of this symbol and it's section.
990 const MCSection *Section = &SCU.Sym->getSection();
991 if (!Section->getKind().isMetadata())
992 SectionMap[Section].push_back(SCU);
994 // Some symbols (e.g. common/bss on mach-o) can have no section but still
995 // appear in the output. This sucks as we rely on sections to build
996 // arange spans. We can do it without, but it's icky.
997 SectionMap[nullptr].push_back(SCU);
1001 // Build a list of sections used.
1002 std::vector<const MCSection *> Sections;
1003 for (const auto &it : SectionMap) {
1004 const MCSection *Section = it.first;
1005 Sections.push_back(Section);
1008 // Sort the sections into order.
1009 // This is only done to ensure consistent output order across different runs.
1010 std::sort(Sections.begin(), Sections.end(), SectionSort);
1012 // Add terminating symbols for each section.
1013 for (unsigned ID = 0, E = Sections.size(); ID != E; ID++) {
1014 const MCSection *Section = Sections[ID];
1015 MCSymbol *Sym = nullptr;
1018 // We can't call MCSection::getLabelEndName, as it's only safe to do so
1019 // if we know the section name up-front. For user-created sections, the
1020 // resulting label may not be valid to use as a label. (section names can
1021 // use a greater set of characters on some systems)
1022 Sym = Asm->GetTempSymbol("debug_end", ID);
1023 Asm->OutStreamer.SwitchSection(Section);
1024 Asm->OutStreamer.EmitLabel(Sym);
1027 // Insert a final terminator.
1028 SectionMap[Section].push_back(SymbolCU(nullptr, Sym));
1032 // Emit all Dwarf sections that should come after the content.
1033 void DwarfDebug::endModule() {
1034 assert(CurFn == nullptr);
1035 assert(CurMI == nullptr);
1040 // End any existing sections.
1041 // TODO: Does this need to happen?
1044 // Finalize the debug info for the module.
1045 finalizeModuleInfo();
1049 // Emit all the DIEs into a debug info section.
1052 // Corresponding abbreviations into a abbrev section.
1053 emitAbbreviations();
1055 // Emit info into a debug aranges section.
1056 if (GenerateARangeSection)
1059 // Emit info into a debug ranges section.
1062 if (useSplitDwarf()) {
1065 emitDebugAbbrevDWO();
1067 // Emit DWO addresses.
1068 AddrPool.emit(*Asm, Asm->getObjFileLowering().getDwarfAddrSection());
1071 // Emit info into a debug loc section.
1074 // Emit info into the dwarf accelerator table sections.
1075 if (useDwarfAccelTables()) {
1078 emitAccelNamespaces();
1082 // Emit the pubnames and pubtypes sections if requested.
1083 if (HasDwarfPubSections) {
1084 emitDebugPubNames(GenerateGnuPubSections);
1085 emitDebugPubTypes(GenerateGnuPubSections);
1091 // Reset these for the next Module if we have one.
1095 // Find abstract variable, if any, associated with Var.
1096 DbgVariable *DwarfDebug::findAbstractVariable(DIVariable &DV,
1097 DebugLoc ScopeLoc) {
1098 LLVMContext &Ctx = DV->getContext();
1099 // More then one inlined variable corresponds to one abstract variable.
1100 DIVariable Var = cleanseInlinedVariable(DV, Ctx);
1101 DbgVariable *AbsDbgVariable = AbstractVariables.lookup(Var);
1103 return AbsDbgVariable;
1105 LexicalScope *Scope = LScopes.findAbstractScope(ScopeLoc.getScope(Ctx));
1109 AbsDbgVariable = new DbgVariable(Var, nullptr, this);
1110 addScopeVariable(Scope, AbsDbgVariable);
1111 AbstractVariables[Var] = AbsDbgVariable;
1112 return AbsDbgVariable;
1115 // If Var is a current function argument then add it to CurrentFnArguments list.
1116 bool DwarfDebug::addCurrentFnArgument(DbgVariable *Var, LexicalScope *Scope) {
1117 if (!LScopes.isCurrentFunctionScope(Scope))
1119 DIVariable DV = Var->getVariable();
1120 if (DV.getTag() != dwarf::DW_TAG_arg_variable)
1122 unsigned ArgNo = DV.getArgNumber();
1126 size_t Size = CurrentFnArguments.size();
1128 CurrentFnArguments.resize(CurFn->getFunction()->arg_size());
1129 // llvm::Function argument size is not good indicator of how many
1130 // arguments does the function have at source level.
1132 CurrentFnArguments.resize(ArgNo * 2);
1133 CurrentFnArguments[ArgNo - 1] = Var;
1137 // Collect variable information from side table maintained by MMI.
1138 void DwarfDebug::collectVariableInfoFromMMITable(
1139 SmallPtrSet<const MDNode *, 16> &Processed) {
1140 for (const auto &VI : MMI->getVariableDbgInfo()) {
1143 Processed.insert(VI.Var);
1144 DIVariable DV(VI.Var);
1145 LexicalScope *Scope = LScopes.findLexicalScope(VI.Loc);
1147 // If variable scope is not found then skip this variable.
1151 DbgVariable *AbsDbgVariable = findAbstractVariable(DV, VI.Loc);
1152 DbgVariable *RegVar = new DbgVariable(DV, AbsDbgVariable, this);
1153 RegVar->setFrameIndex(VI.Slot);
1154 if (!addCurrentFnArgument(RegVar, Scope))
1155 addScopeVariable(Scope, RegVar);
1157 AbsDbgVariable->setFrameIndex(VI.Slot);
1161 // Return true if debug value, encoded by DBG_VALUE instruction, is in a
1163 static bool isDbgValueInDefinedReg(const MachineInstr *MI) {
1164 assert(MI->isDebugValue() && "Invalid DBG_VALUE machine instruction!");
1165 return MI->getNumOperands() == 3 && MI->getOperand(0).isReg() &&
1166 MI->getOperand(0).getReg() &&
1167 (MI->getOperand(1).isImm() ||
1168 (MI->getOperand(1).isReg() && MI->getOperand(1).getReg() == 0U));
1171 // Get .debug_loc entry for the instruction range starting at MI.
1172 static DebugLocEntry::Value getDebugLocValue(const MachineInstr *MI) {
1173 const MDNode *Var = MI->getDebugVariable();
1175 assert(MI->getNumOperands() == 3);
1176 if (MI->getOperand(0).isReg()) {
1177 MachineLocation MLoc;
1178 // If the second operand is an immediate, this is a
1179 // register-indirect address.
1180 if (!MI->getOperand(1).isImm())
1181 MLoc.set(MI->getOperand(0).getReg());
1183 MLoc.set(MI->getOperand(0).getReg(), MI->getOperand(1).getImm());
1184 return DebugLocEntry::Value(Var, MLoc);
1186 if (MI->getOperand(0).isImm())
1187 return DebugLocEntry::Value(Var, MI->getOperand(0).getImm());
1188 if (MI->getOperand(0).isFPImm())
1189 return DebugLocEntry::Value(Var, MI->getOperand(0).getFPImm());
1190 if (MI->getOperand(0).isCImm())
1191 return DebugLocEntry::Value(Var, MI->getOperand(0).getCImm());
1193 llvm_unreachable("Unexpected 3 operand DBG_VALUE instruction!");
1196 // Find variables for each lexical scope.
1198 DwarfDebug::collectVariableInfo(SmallPtrSet<const MDNode *, 16> &Processed) {
1199 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1200 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1202 // Grab the variable info that was squirreled away in the MMI side-table.
1203 collectVariableInfoFromMMITable(Processed);
1205 for (const MDNode *Var : UserVariables) {
1206 if (Processed.count(Var))
1209 // History contains relevant DBG_VALUE instructions for Var and instructions
1211 SmallVectorImpl<const MachineInstr *> &History = DbgValues[Var];
1212 if (History.empty())
1214 const MachineInstr *MInsn = History.front();
1217 LexicalScope *Scope = nullptr;
1218 if (DV.getTag() == dwarf::DW_TAG_arg_variable &&
1219 DISubprogram(DV.getContext()).describes(CurFn->getFunction()))
1220 Scope = LScopes.getCurrentFunctionScope();
1221 else if (MDNode *IA = DV.getInlinedAt())
1222 Scope = LScopes.findInlinedScope(DebugLoc::getFromDILocation(IA));
1224 Scope = LScopes.findLexicalScope(cast<MDNode>(DV->getOperand(1)));
1225 // If variable scope is not found then skip this variable.
1229 Processed.insert(DV);
1230 assert(MInsn->isDebugValue() && "History must begin with debug value");
1231 DbgVariable *AbsVar = findAbstractVariable(DV, MInsn->getDebugLoc());
1232 DbgVariable *RegVar = new DbgVariable(DV, AbsVar, this);
1233 if (!addCurrentFnArgument(RegVar, Scope))
1234 addScopeVariable(Scope, RegVar);
1236 AbsVar->setMInsn(MInsn);
1238 // Simplify ranges that are fully coalesced.
1239 if (History.size() <= 1 ||
1240 (History.size() == 2 && MInsn->isIdenticalTo(History.back()))) {
1241 RegVar->setMInsn(MInsn);
1245 // Handle multiple DBG_VALUE instructions describing one variable.
1246 RegVar->setDotDebugLocOffset(DotDebugLocEntries.size());
1248 DotDebugLocEntries.resize(DotDebugLocEntries.size() + 1);
1249 DebugLocList &LocList = DotDebugLocEntries.back();
1251 Asm->GetTempSymbol("debug_loc", DotDebugLocEntries.size() - 1);
1252 SmallVector<DebugLocEntry, 4> &DebugLoc = LocList.List;
1253 for (SmallVectorImpl<const MachineInstr *>::const_iterator
1254 HI = History.begin(),
1257 const MachineInstr *Begin = *HI;
1258 assert(Begin->isDebugValue() && "Invalid History entry");
1260 // Check if DBG_VALUE is truncating a range.
1261 if (Begin->getNumOperands() > 1 && Begin->getOperand(0).isReg() &&
1262 !Begin->getOperand(0).getReg())
1265 // Compute the range for a register location.
1266 const MCSymbol *FLabel = getLabelBeforeInsn(Begin);
1267 const MCSymbol *SLabel = nullptr;
1270 // If Begin is the last instruction in History then its value is valid
1271 // until the end of the function.
1272 SLabel = FunctionEndSym;
1274 const MachineInstr *End = HI[1];
1275 DEBUG(dbgs() << "DotDebugLoc Pair:\n"
1276 << "\t" << *Begin << "\t" << *End << "\n");
1277 if (End->isDebugValue())
1278 SLabel = getLabelBeforeInsn(End);
1280 // End is a normal instruction clobbering the range.
1281 SLabel = getLabelAfterInsn(End);
1282 assert(SLabel && "Forgot label after clobber instruction");
1287 // The value is valid until the next DBG_VALUE or clobber.
1288 DebugLocEntry Loc(FLabel, SLabel, getDebugLocValue(Begin), TheCU);
1289 if (DebugLoc.empty() || !DebugLoc.back().Merge(Loc))
1290 DebugLoc.push_back(std::move(Loc));
1294 // Collect info for variables that were optimized out.
1295 DIArray Variables = DISubprogram(FnScope->getScopeNode()).getVariables();
1296 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1297 DIVariable DV(Variables.getElement(i));
1298 if (!DV || !DV.isVariable() || !Processed.insert(DV))
1300 if (LexicalScope *Scope = LScopes.findLexicalScope(DV.getContext()))
1301 addScopeVariable(Scope, new DbgVariable(DV, nullptr, this));
1305 // Return Label preceding the instruction.
1306 MCSymbol *DwarfDebug::getLabelBeforeInsn(const MachineInstr *MI) {
1307 MCSymbol *Label = LabelsBeforeInsn.lookup(MI);
1308 assert(Label && "Didn't insert label before instruction");
1312 // Return Label immediately following the instruction.
1313 MCSymbol *DwarfDebug::getLabelAfterInsn(const MachineInstr *MI) {
1314 return LabelsAfterInsn.lookup(MI);
1317 // Process beginning of an instruction.
1318 void DwarfDebug::beginInstruction(const MachineInstr *MI) {
1319 assert(CurMI == nullptr);
1321 // Check if source location changes, but ignore DBG_VALUE locations.
1322 if (!MI->isDebugValue()) {
1323 DebugLoc DL = MI->getDebugLoc();
1324 if (DL != PrevInstLoc && (!DL.isUnknown() || UnknownLocations)) {
1327 if (DL == PrologEndLoc) {
1328 Flags |= DWARF2_FLAG_PROLOGUE_END;
1329 PrologEndLoc = DebugLoc();
1331 if (PrologEndLoc.isUnknown())
1332 Flags |= DWARF2_FLAG_IS_STMT;
1334 if (!DL.isUnknown()) {
1335 const MDNode *Scope = DL.getScope(Asm->MF->getFunction()->getContext());
1336 recordSourceLine(DL.getLine(), DL.getCol(), Scope, Flags);
1338 recordSourceLine(0, 0, nullptr, 0);
1342 // Insert labels where requested.
1343 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1344 LabelsBeforeInsn.find(MI);
1347 if (I == LabelsBeforeInsn.end())
1350 // Label already assigned.
1355 PrevLabel = MMI->getContext().CreateTempSymbol();
1356 Asm->OutStreamer.EmitLabel(PrevLabel);
1358 I->second = PrevLabel;
1361 // Process end of an instruction.
1362 void DwarfDebug::endInstruction() {
1363 assert(CurMI != nullptr);
1364 // Don't create a new label after DBG_VALUE instructions.
1365 // They don't generate code.
1366 if (!CurMI->isDebugValue())
1367 PrevLabel = nullptr;
1369 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1370 LabelsAfterInsn.find(CurMI);
1374 if (I == LabelsAfterInsn.end())
1377 // Label already assigned.
1381 // We need a label after this instruction.
1383 PrevLabel = MMI->getContext().CreateTempSymbol();
1384 Asm->OutStreamer.EmitLabel(PrevLabel);
1386 I->second = PrevLabel;
1389 // Each LexicalScope has first instruction and last instruction to mark
1390 // beginning and end of a scope respectively. Create an inverse map that list
1391 // scopes starts (and ends) with an instruction. One instruction may start (or
1392 // end) multiple scopes. Ignore scopes that are not reachable.
1393 void DwarfDebug::identifyScopeMarkers() {
1394 SmallVector<LexicalScope *, 4> WorkList;
1395 WorkList.push_back(LScopes.getCurrentFunctionScope());
1396 while (!WorkList.empty()) {
1397 LexicalScope *S = WorkList.pop_back_val();
1399 const SmallVectorImpl<LexicalScope *> &Children = S->getChildren();
1400 if (!Children.empty())
1401 WorkList.append(Children.begin(), Children.end());
1403 if (S->isAbstractScope())
1406 for (const InsnRange &R : S->getRanges()) {
1407 assert(R.first && "InsnRange does not have first instruction!");
1408 assert(R.second && "InsnRange does not have second instruction!");
1409 requestLabelBeforeInsn(R.first);
1410 requestLabelAfterInsn(R.second);
1415 // Gather pre-function debug information. Assumes being called immediately
1416 // after the function entry point has been emitted.
1417 void DwarfDebug::beginFunction(const MachineFunction *MF) {
1420 // If there's no debug info for the function we're not going to do anything.
1421 if (!MMI->hasDebugInfo())
1424 // Grab the lexical scopes for the function, if we don't have any of those
1425 // then we're not going to be able to do anything.
1426 LScopes.initialize(*MF);
1427 if (LScopes.empty())
1430 assert(UserVariables.empty() && DbgValues.empty() && "Maps weren't cleaned");
1432 // Make sure that each lexical scope will have a begin/end label.
1433 identifyScopeMarkers();
1435 // Set DwarfDwarfCompileUnitID in MCContext to the Compile Unit this function
1436 // belongs to so that we add to the correct per-cu line table in the
1438 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1439 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1440 assert(TheCU && "Unable to find compile unit!");
1441 if (Asm->OutStreamer.hasRawTextSupport())
1442 // Use a single line table if we are generating assembly.
1443 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1445 Asm->OutStreamer.getContext().setDwarfCompileUnitID(TheCU->getUniqueID());
1447 // Emit a label for the function so that we have a beginning address.
1448 FunctionBeginSym = Asm->GetTempSymbol("func_begin", Asm->getFunctionNumber());
1449 // Assumes in correct section after the entry point.
1450 Asm->OutStreamer.EmitLabel(FunctionBeginSym);
1452 const TargetRegisterInfo *TRI = Asm->TM.getRegisterInfo();
1453 // LiveUserVar - Map physreg numbers to the MDNode they contain.
1454 std::vector<const MDNode *> LiveUserVar(TRI->getNumRegs());
1456 for (MachineFunction::const_iterator I = MF->begin(), E = MF->end(); I != E;
1458 bool AtBlockEntry = true;
1459 for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end();
1461 const MachineInstr *MI = II;
1463 if (MI->isDebugValue()) {
1464 assert(MI->getNumOperands() > 1 && "Invalid machine instruction!");
1466 // Keep track of user variables.
1467 const MDNode *Var = MI->getDebugVariable();
1469 // Variable is in a register, we need to check for clobbers.
1470 if (isDbgValueInDefinedReg(MI))
1471 LiveUserVar[MI->getOperand(0).getReg()] = Var;
1473 // Check the history of this variable.
1474 SmallVectorImpl<const MachineInstr *> &History = DbgValues[Var];
1475 if (History.empty()) {
1476 UserVariables.push_back(Var);
1477 // The first mention of a function argument gets the FunctionBeginSym
1478 // label, so arguments are visible when breaking at function entry.
1480 if (DV.isVariable() && DV.getTag() == dwarf::DW_TAG_arg_variable &&
1481 getDISubprogram(DV.getContext()).describes(MF->getFunction()))
1482 LabelsBeforeInsn[MI] = FunctionBeginSym;
1484 // We have seen this variable before. Try to coalesce DBG_VALUEs.
1485 const MachineInstr *Prev = History.back();
1486 if (Prev->isDebugValue()) {
1487 // Coalesce identical entries at the end of History.
1488 if (History.size() >= 2 &&
1489 Prev->isIdenticalTo(History[History.size() - 2])) {
1490 DEBUG(dbgs() << "Coalescing identical DBG_VALUE entries:\n"
1491 << "\t" << *Prev << "\t"
1492 << *History[History.size() - 2] << "\n");
1496 // Terminate old register assignments that don't reach MI;
1497 MachineFunction::const_iterator PrevMBB = Prev->getParent();
1498 if (PrevMBB != I && (!AtBlockEntry || std::next(PrevMBB) != I) &&
1499 isDbgValueInDefinedReg(Prev)) {
1500 // Previous register assignment needs to terminate at the end of
1502 MachineBasicBlock::const_iterator LastMI =
1503 PrevMBB->getLastNonDebugInstr();
1504 if (LastMI == PrevMBB->end()) {
1505 // Drop DBG_VALUE for empty range.
1506 DEBUG(dbgs() << "Dropping DBG_VALUE for empty range:\n"
1507 << "\t" << *Prev << "\n");
1509 } else if (std::next(PrevMBB) != PrevMBB->getParent()->end())
1510 // Terminate after LastMI.
1511 History.push_back(LastMI);
1515 History.push_back(MI);
1517 // Not a DBG_VALUE instruction.
1518 if (!MI->isPosition())
1519 AtBlockEntry = false;
1521 // First known non-DBG_VALUE and non-frame setup location marks
1522 // the beginning of the function body.
1523 if (!MI->getFlag(MachineInstr::FrameSetup) &&
1524 (PrologEndLoc.isUnknown() && !MI->getDebugLoc().isUnknown()))
1525 PrologEndLoc = MI->getDebugLoc();
1527 // Check if the instruction clobbers any registers with debug vars.
1528 for (const MachineOperand &MO : MI->operands()) {
1529 if (!MO.isReg() || !MO.isDef() || !MO.getReg())
1531 for (MCRegAliasIterator AI(MO.getReg(), TRI, true); AI.isValid();
1534 const MDNode *Var = LiveUserVar[Reg];
1537 // Reg is now clobbered.
1538 LiveUserVar[Reg] = nullptr;
1540 // Was MD last defined by a DBG_VALUE referring to Reg?
1541 DbgValueHistoryMap::iterator HistI = DbgValues.find(Var);
1542 if (HistI == DbgValues.end())
1544 SmallVectorImpl<const MachineInstr *> &History = HistI->second;
1545 if (History.empty())
1547 const MachineInstr *Prev = History.back();
1548 // Sanity-check: Register assignments are terminated at the end of
1550 if (!Prev->isDebugValue() || Prev->getParent() != MI->getParent())
1552 // Is the variable still in Reg?
1553 if (!isDbgValueInDefinedReg(Prev) ||
1554 Prev->getOperand(0).getReg() != Reg)
1556 // Var is clobbered. Make sure the next instruction gets a label.
1557 History.push_back(MI);
1564 for (auto &I : DbgValues) {
1565 SmallVectorImpl<const MachineInstr *> &History = I.second;
1566 if (History.empty())
1569 // Make sure the final register assignments are terminated.
1570 const MachineInstr *Prev = History.back();
1571 if (Prev->isDebugValue() && isDbgValueInDefinedReg(Prev)) {
1572 const MachineBasicBlock *PrevMBB = Prev->getParent();
1573 MachineBasicBlock::const_iterator LastMI =
1574 PrevMBB->getLastNonDebugInstr();
1575 if (LastMI == PrevMBB->end())
1576 // Drop DBG_VALUE for empty range.
1578 else if (PrevMBB != &PrevMBB->getParent()->back()) {
1579 // Terminate after LastMI.
1580 History.push_back(LastMI);
1583 // Request labels for the full history.
1584 for (const MachineInstr *MI : History) {
1585 if (MI->isDebugValue())
1586 requestLabelBeforeInsn(MI);
1588 requestLabelAfterInsn(MI);
1592 PrevInstLoc = DebugLoc();
1593 PrevLabel = FunctionBeginSym;
1595 // Record beginning of function.
1596 if (!PrologEndLoc.isUnknown()) {
1597 DebugLoc FnStartDL =
1598 PrologEndLoc.getFnDebugLoc(MF->getFunction()->getContext());
1600 FnStartDL.getLine(), FnStartDL.getCol(),
1601 FnStartDL.getScope(MF->getFunction()->getContext()),
1602 // We'd like to list the prologue as "not statements" but GDB behaves
1603 // poorly if we do that. Revisit this with caution/GDB (7.5+) testing.
1604 DWARF2_FLAG_IS_STMT);
1608 void DwarfDebug::addScopeVariable(LexicalScope *LS, DbgVariable *Var) {
1609 SmallVectorImpl<DbgVariable *> &Vars = ScopeVariables[LS];
1610 DIVariable DV = Var->getVariable();
1611 // Variables with positive arg numbers are parameters.
1612 if (unsigned ArgNum = DV.getArgNumber()) {
1613 // Keep all parameters in order at the start of the variable list to ensure
1614 // function types are correct (no out-of-order parameters)
1616 // This could be improved by only doing it for optimized builds (unoptimized
1617 // builds have the right order to begin with), searching from the back (this
1618 // would catch the unoptimized case quickly), or doing a binary search
1619 // rather than linear search.
1620 SmallVectorImpl<DbgVariable *>::iterator I = Vars.begin();
1621 while (I != Vars.end()) {
1622 unsigned CurNum = (*I)->getVariable().getArgNumber();
1623 // A local (non-parameter) variable has been found, insert immediately
1627 // A later indexed parameter has been found, insert immediately before it.
1628 if (CurNum > ArgNum)
1632 Vars.insert(I, Var);
1636 Vars.push_back(Var);
1639 // Gather and emit post-function debug information.
1640 void DwarfDebug::endFunction(const MachineFunction *MF) {
1641 // Every beginFunction(MF) call should be followed by an endFunction(MF) call,
1642 // though the beginFunction may not be called at all.
1643 // We should handle both cases.
1647 assert(CurFn == MF);
1648 assert(CurFn != nullptr);
1650 if (!MMI->hasDebugInfo() || LScopes.empty()) {
1651 // If we don't have a lexical scope for this function then there will
1652 // be a hole in the range information. Keep note of this by setting the
1653 // previously used section to nullptr.
1654 PrevSection = nullptr;
1660 // Define end label for subprogram.
1661 FunctionEndSym = Asm->GetTempSymbol("func_end", Asm->getFunctionNumber());
1662 // Assumes in correct section after the entry point.
1663 Asm->OutStreamer.EmitLabel(FunctionEndSym);
1665 // Set DwarfDwarfCompileUnitID in MCContext to default value.
1666 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1668 SmallPtrSet<const MDNode *, 16> ProcessedVars;
1669 collectVariableInfo(ProcessedVars);
1671 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1672 DwarfCompileUnit &TheCU = *SPMap.lookup(FnScope->getScopeNode());
1674 // Construct abstract scopes.
1675 for (LexicalScope *AScope : LScopes.getAbstractScopesList()) {
1676 DISubprogram SP(AScope->getScopeNode());
1677 if (SP.isSubprogram()) {
1678 // Collect info for variables that were optimized out.
1679 DIArray Variables = SP.getVariables();
1680 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1681 DIVariable DV(Variables.getElement(i));
1682 if (!DV || !DV.isVariable() || !ProcessedVars.insert(DV))
1684 // Check that DbgVariable for DV wasn't created earlier, when
1685 // findAbstractVariable() was called for inlined instance of DV.
1686 LLVMContext &Ctx = DV->getContext();
1687 DIVariable CleanDV = cleanseInlinedVariable(DV, Ctx);
1688 if (AbstractVariables.lookup(CleanDV))
1690 if (LexicalScope *Scope = LScopes.findAbstractScope(DV.getContext()))
1691 addScopeVariable(Scope, new DbgVariable(DV, nullptr, this));
1694 if (ProcessedSPNodes.count(AScope->getScopeNode()) == 0)
1695 constructAbstractSubprogramScopeDIE(TheCU, AScope);
1698 DIE &CurFnDIE = constructSubprogramScopeDIE(TheCU, FnScope);
1699 if (!CurFn->getTarget().Options.DisableFramePointerElim(*CurFn))
1700 TheCU.addFlag(CurFnDIE, dwarf::DW_AT_APPLE_omit_frame_ptr);
1702 // Add the range of this function to the list of ranges for the CU.
1703 RangeSpan Span(FunctionBeginSym, FunctionEndSym);
1704 TheCU.addRange(std::move(Span));
1705 PrevSection = Asm->getCurrentSection();
1709 for (auto &I : ScopeVariables)
1710 DeleteContainerPointers(I.second);
1711 ScopeVariables.clear();
1712 DeleteContainerPointers(CurrentFnArguments);
1713 UserVariables.clear();
1715 AbstractVariables.clear();
1716 LabelsBeforeInsn.clear();
1717 LabelsAfterInsn.clear();
1718 PrevLabel = nullptr;
1722 // Register a source line with debug info. Returns the unique label that was
1723 // emitted and which provides correspondence to the source line list.
1724 void DwarfDebug::recordSourceLine(unsigned Line, unsigned Col, const MDNode *S,
1729 unsigned Discriminator = 0;
1731 DIDescriptor Scope(S);
1733 if (Scope.isCompileUnit()) {
1734 DICompileUnit CU(S);
1735 Fn = CU.getFilename();
1736 Dir = CU.getDirectory();
1737 } else if (Scope.isFile()) {
1739 Fn = F.getFilename();
1740 Dir = F.getDirectory();
1741 } else if (Scope.isSubprogram()) {
1743 Fn = SP.getFilename();
1744 Dir = SP.getDirectory();
1745 } else if (Scope.isLexicalBlockFile()) {
1746 DILexicalBlockFile DBF(S);
1747 Fn = DBF.getFilename();
1748 Dir = DBF.getDirectory();
1749 } else if (Scope.isLexicalBlock()) {
1750 DILexicalBlock DB(S);
1751 Fn = DB.getFilename();
1752 Dir = DB.getDirectory();
1753 Discriminator = DB.getDiscriminator();
1755 llvm_unreachable("Unexpected scope info");
1757 unsigned CUID = Asm->OutStreamer.getContext().getDwarfCompileUnitID();
1758 Src = static_cast<DwarfCompileUnit &>(*InfoHolder.getUnits()[CUID])
1759 .getOrCreateSourceID(Fn, Dir);
1761 Asm->OutStreamer.EmitDwarfLocDirective(Src, Line, Col, Flags, 0,
1765 //===----------------------------------------------------------------------===//
1767 //===----------------------------------------------------------------------===//
1769 // Emit initial Dwarf sections with a label at the start of each one.
1770 void DwarfDebug::emitSectionLabels() {
1771 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
1773 // Dwarf sections base addresses.
1774 DwarfInfoSectionSym =
1775 emitSectionSym(Asm, TLOF.getDwarfInfoSection(), "section_info");
1776 if (useSplitDwarf())
1777 DwarfInfoDWOSectionSym =
1778 emitSectionSym(Asm, TLOF.getDwarfInfoDWOSection(), "section_info_dwo");
1779 DwarfAbbrevSectionSym =
1780 emitSectionSym(Asm, TLOF.getDwarfAbbrevSection(), "section_abbrev");
1781 if (useSplitDwarf())
1782 DwarfAbbrevDWOSectionSym = emitSectionSym(
1783 Asm, TLOF.getDwarfAbbrevDWOSection(), "section_abbrev_dwo");
1784 if (GenerateARangeSection)
1785 emitSectionSym(Asm, TLOF.getDwarfARangesSection());
1787 DwarfLineSectionSym =
1788 emitSectionSym(Asm, TLOF.getDwarfLineSection(), "section_line");
1789 if (GenerateGnuPubSections) {
1790 DwarfGnuPubNamesSectionSym =
1791 emitSectionSym(Asm, TLOF.getDwarfGnuPubNamesSection());
1792 DwarfGnuPubTypesSectionSym =
1793 emitSectionSym(Asm, TLOF.getDwarfGnuPubTypesSection());
1794 } else if (HasDwarfPubSections) {
1795 emitSectionSym(Asm, TLOF.getDwarfPubNamesSection());
1796 emitSectionSym(Asm, TLOF.getDwarfPubTypesSection());
1799 DwarfStrSectionSym =
1800 emitSectionSym(Asm, TLOF.getDwarfStrSection(), "info_string");
1801 if (useSplitDwarf()) {
1802 DwarfStrDWOSectionSym =
1803 emitSectionSym(Asm, TLOF.getDwarfStrDWOSection(), "skel_string");
1804 DwarfAddrSectionSym =
1805 emitSectionSym(Asm, TLOF.getDwarfAddrSection(), "addr_sec");
1806 DwarfDebugLocSectionSym =
1807 emitSectionSym(Asm, TLOF.getDwarfLocDWOSection(), "skel_loc");
1809 DwarfDebugLocSectionSym =
1810 emitSectionSym(Asm, TLOF.getDwarfLocSection(), "section_debug_loc");
1811 DwarfDebugRangeSectionSym =
1812 emitSectionSym(Asm, TLOF.getDwarfRangesSection(), "debug_range");
1815 // Recursively emits a debug information entry.
1816 void DwarfDebug::emitDIE(DIE &Die) {
1817 // Get the abbreviation for this DIE.
1818 const DIEAbbrev &Abbrev = Die.getAbbrev();
1820 // Emit the code (index) for the abbreviation.
1821 if (Asm->isVerbose())
1822 Asm->OutStreamer.AddComment("Abbrev [" + Twine(Abbrev.getNumber()) +
1823 "] 0x" + Twine::utohexstr(Die.getOffset()) +
1824 ":0x" + Twine::utohexstr(Die.getSize()) + " " +
1825 dwarf::TagString(Abbrev.getTag()));
1826 Asm->EmitULEB128(Abbrev.getNumber());
1828 const SmallVectorImpl<DIEValue *> &Values = Die.getValues();
1829 const SmallVectorImpl<DIEAbbrevData> &AbbrevData = Abbrev.getData();
1831 // Emit the DIE attribute values.
1832 for (unsigned i = 0, N = Values.size(); i < N; ++i) {
1833 dwarf::Attribute Attr = AbbrevData[i].getAttribute();
1834 dwarf::Form Form = AbbrevData[i].getForm();
1835 assert(Form && "Too many attributes for DIE (check abbreviation)");
1837 if (Asm->isVerbose()) {
1838 Asm->OutStreamer.AddComment(dwarf::AttributeString(Attr));
1839 if (Attr == dwarf::DW_AT_accessibility)
1840 Asm->OutStreamer.AddComment(dwarf::AccessibilityString(
1841 cast<DIEInteger>(Values[i])->getValue()));
1844 // Emit an attribute using the defined form.
1845 Values[i]->EmitValue(Asm, Form);
1848 // Emit the DIE children if any.
1849 if (Abbrev.hasChildren()) {
1850 for (auto &Child : Die.getChildren())
1853 Asm->OutStreamer.AddComment("End Of Children Mark");
1858 // Emit the debug info section.
1859 void DwarfDebug::emitDebugInfo() {
1860 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1862 Holder.emitUnits(this, DwarfAbbrevSectionSym);
1865 // Emit the abbreviation section.
1866 void DwarfDebug::emitAbbreviations() {
1867 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1869 Holder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevSection());
1872 // Emit the last address of the section and the end of the line matrix.
1873 void DwarfDebug::emitEndOfLineMatrix(unsigned SectionEnd) {
1874 // Define last address of section.
1875 Asm->OutStreamer.AddComment("Extended Op");
1878 Asm->OutStreamer.AddComment("Op size");
1879 Asm->EmitInt8(Asm->getDataLayout().getPointerSize() + 1);
1880 Asm->OutStreamer.AddComment("DW_LNE_set_address");
1881 Asm->EmitInt8(dwarf::DW_LNE_set_address);
1883 Asm->OutStreamer.AddComment("Section end label");
1885 Asm->OutStreamer.EmitSymbolValue(
1886 Asm->GetTempSymbol("section_end", SectionEnd),
1887 Asm->getDataLayout().getPointerSize());
1889 // Mark end of matrix.
1890 Asm->OutStreamer.AddComment("DW_LNE_end_sequence");
1896 // Emit visible names into a hashed accelerator table section.
1897 void DwarfDebug::emitAccelNames() {
1898 AccelNames.FinalizeTable(Asm, "Names");
1899 Asm->OutStreamer.SwitchSection(
1900 Asm->getObjFileLowering().getDwarfAccelNamesSection());
1901 MCSymbol *SectionBegin = Asm->GetTempSymbol("names_begin");
1902 Asm->OutStreamer.EmitLabel(SectionBegin);
1904 // Emit the full data.
1905 AccelNames.Emit(Asm, SectionBegin, &InfoHolder);
1908 // Emit objective C classes and categories into a hashed accelerator table
1910 void DwarfDebug::emitAccelObjC() {
1911 AccelObjC.FinalizeTable(Asm, "ObjC");
1912 Asm->OutStreamer.SwitchSection(
1913 Asm->getObjFileLowering().getDwarfAccelObjCSection());
1914 MCSymbol *SectionBegin = Asm->GetTempSymbol("objc_begin");
1915 Asm->OutStreamer.EmitLabel(SectionBegin);
1917 // Emit the full data.
1918 AccelObjC.Emit(Asm, SectionBegin, &InfoHolder);
1921 // Emit namespace dies into a hashed accelerator table.
1922 void DwarfDebug::emitAccelNamespaces() {
1923 AccelNamespace.FinalizeTable(Asm, "namespac");
1924 Asm->OutStreamer.SwitchSection(
1925 Asm->getObjFileLowering().getDwarfAccelNamespaceSection());
1926 MCSymbol *SectionBegin = Asm->GetTempSymbol("namespac_begin");
1927 Asm->OutStreamer.EmitLabel(SectionBegin);
1929 // Emit the full data.
1930 AccelNamespace.Emit(Asm, SectionBegin, &InfoHolder);
1933 // Emit type dies into a hashed accelerator table.
1934 void DwarfDebug::emitAccelTypes() {
1936 AccelTypes.FinalizeTable(Asm, "types");
1937 Asm->OutStreamer.SwitchSection(
1938 Asm->getObjFileLowering().getDwarfAccelTypesSection());
1939 MCSymbol *SectionBegin = Asm->GetTempSymbol("types_begin");
1940 Asm->OutStreamer.EmitLabel(SectionBegin);
1942 // Emit the full data.
1943 AccelTypes.Emit(Asm, SectionBegin, &InfoHolder);
1946 // Public name handling.
1947 // The format for the various pubnames:
1949 // dwarf pubnames - offset/name pairs where the offset is the offset into the CU
1950 // for the DIE that is named.
1952 // gnu pubnames - offset/index value/name tuples where the offset is the offset
1953 // into the CU and the index value is computed according to the type of value
1954 // for the DIE that is named.
1956 // For type units the offset is the offset of the skeleton DIE. For split dwarf
1957 // it's the offset within the debug_info/debug_types dwo section, however, the
1958 // reference in the pubname header doesn't change.
1960 /// computeIndexValue - Compute the gdb index value for the DIE and CU.
1961 static dwarf::PubIndexEntryDescriptor computeIndexValue(DwarfUnit *CU,
1963 dwarf::GDBIndexEntryLinkage Linkage = dwarf::GIEL_STATIC;
1965 // We could have a specification DIE that has our most of our knowledge,
1966 // look for that now.
1967 DIEValue *SpecVal = Die->findAttribute(dwarf::DW_AT_specification);
1969 DIE &SpecDIE = cast<DIEEntry>(SpecVal)->getEntry();
1970 if (SpecDIE.findAttribute(dwarf::DW_AT_external))
1971 Linkage = dwarf::GIEL_EXTERNAL;
1972 } else if (Die->findAttribute(dwarf::DW_AT_external))
1973 Linkage = dwarf::GIEL_EXTERNAL;
1975 switch (Die->getTag()) {
1976 case dwarf::DW_TAG_class_type:
1977 case dwarf::DW_TAG_structure_type:
1978 case dwarf::DW_TAG_union_type:
1979 case dwarf::DW_TAG_enumeration_type:
1980 return dwarf::PubIndexEntryDescriptor(
1981 dwarf::GIEK_TYPE, CU->getLanguage() != dwarf::DW_LANG_C_plus_plus
1982 ? dwarf::GIEL_STATIC
1983 : dwarf::GIEL_EXTERNAL);
1984 case dwarf::DW_TAG_typedef:
1985 case dwarf::DW_TAG_base_type:
1986 case dwarf::DW_TAG_subrange_type:
1987 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_TYPE, dwarf::GIEL_STATIC);
1988 case dwarf::DW_TAG_namespace:
1989 return dwarf::GIEK_TYPE;
1990 case dwarf::DW_TAG_subprogram:
1991 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_FUNCTION, Linkage);
1992 case dwarf::DW_TAG_constant:
1993 case dwarf::DW_TAG_variable:
1994 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE, Linkage);
1995 case dwarf::DW_TAG_enumerator:
1996 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE,
1997 dwarf::GIEL_STATIC);
1999 return dwarf::GIEK_NONE;
2003 /// emitDebugPubNames - Emit visible names into a debug pubnames section.
2005 void DwarfDebug::emitDebugPubNames(bool GnuStyle) {
2006 const MCSection *PSec =
2007 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubNamesSection()
2008 : Asm->getObjFileLowering().getDwarfPubNamesSection();
2010 emitDebugPubSection(GnuStyle, PSec, "Names", &DwarfUnit::getGlobalNames);
2013 void DwarfDebug::emitDebugPubSection(
2014 bool GnuStyle, const MCSection *PSec, StringRef Name,
2015 const StringMap<const DIE *> &(DwarfUnit::*Accessor)() const) {
2016 for (const auto &NU : CUMap) {
2017 DwarfCompileUnit *TheU = NU.second;
2019 const auto &Globals = (TheU->*Accessor)();
2021 if (Globals.empty())
2024 if (auto Skeleton = static_cast<DwarfCompileUnit *>(TheU->getSkeleton()))
2026 unsigned ID = TheU->getUniqueID();
2028 // Start the dwarf pubnames section.
2029 Asm->OutStreamer.SwitchSection(PSec);
2032 Asm->OutStreamer.AddComment("Length of Public " + Name + " Info");
2033 MCSymbol *BeginLabel = Asm->GetTempSymbol("pub" + Name + "_begin", ID);
2034 MCSymbol *EndLabel = Asm->GetTempSymbol("pub" + Name + "_end", ID);
2035 Asm->EmitLabelDifference(EndLabel, BeginLabel, 4);
2037 Asm->OutStreamer.EmitLabel(BeginLabel);
2039 Asm->OutStreamer.AddComment("DWARF Version");
2040 Asm->EmitInt16(dwarf::DW_PUBNAMES_VERSION);
2042 Asm->OutStreamer.AddComment("Offset of Compilation Unit Info");
2043 Asm->EmitSectionOffset(TheU->getLabelBegin(), TheU->getSectionSym());
2045 Asm->OutStreamer.AddComment("Compilation Unit Length");
2046 Asm->EmitLabelDifference(TheU->getLabelEnd(), TheU->getLabelBegin(), 4);
2048 // Emit the pubnames for this compilation unit.
2049 for (const auto &GI : Globals) {
2050 const char *Name = GI.getKeyData();
2051 const DIE *Entity = GI.second;
2053 Asm->OutStreamer.AddComment("DIE offset");
2054 Asm->EmitInt32(Entity->getOffset());
2057 dwarf::PubIndexEntryDescriptor Desc = computeIndexValue(TheU, Entity);
2058 Asm->OutStreamer.AddComment(
2059 Twine("Kind: ") + dwarf::GDBIndexEntryKindString(Desc.Kind) + ", " +
2060 dwarf::GDBIndexEntryLinkageString(Desc.Linkage));
2061 Asm->EmitInt8(Desc.toBits());
2064 Asm->OutStreamer.AddComment("External Name");
2065 Asm->OutStreamer.EmitBytes(StringRef(Name, GI.getKeyLength() + 1));
2068 Asm->OutStreamer.AddComment("End Mark");
2070 Asm->OutStreamer.EmitLabel(EndLabel);
2074 void DwarfDebug::emitDebugPubTypes(bool GnuStyle) {
2075 const MCSection *PSec =
2076 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubTypesSection()
2077 : Asm->getObjFileLowering().getDwarfPubTypesSection();
2079 emitDebugPubSection(GnuStyle, PSec, "Types", &DwarfUnit::getGlobalTypes);
2082 // Emit visible names into a debug str section.
2083 void DwarfDebug::emitDebugStr() {
2084 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
2085 Holder.emitStrings(Asm->getObjFileLowering().getDwarfStrSection());
2088 void DwarfDebug::emitDebugLocEntry(ByteStreamer &Streamer,
2089 const DebugLocEntry &Entry) {
2090 assert(Entry.getValues().size() == 1 &&
2091 "multi-value entries are not supported yet.");
2092 const DebugLocEntry::Value Value = Entry.getValues()[0];
2093 DIVariable DV(Value.getVariable());
2094 if (Value.isInt()) {
2095 DIBasicType BTy(resolve(DV.getType()));
2096 if (BTy.Verify() && (BTy.getEncoding() == dwarf::DW_ATE_signed ||
2097 BTy.getEncoding() == dwarf::DW_ATE_signed_char)) {
2098 Streamer.EmitInt8(dwarf::DW_OP_consts, "DW_OP_consts");
2099 Streamer.EmitSLEB128(Value.getInt());
2101 Streamer.EmitInt8(dwarf::DW_OP_constu, "DW_OP_constu");
2102 Streamer.EmitULEB128(Value.getInt());
2104 } else if (Value.isLocation()) {
2105 MachineLocation Loc = Value.getLoc();
2106 if (!DV.hasComplexAddress())
2108 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2110 // Complex address entry.
2111 unsigned N = DV.getNumAddrElements();
2113 if (N >= 2 && DV.getAddrElement(0) == DIBuilder::OpPlus) {
2114 if (Loc.getOffset()) {
2116 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2117 Streamer.EmitInt8(dwarf::DW_OP_deref, "DW_OP_deref");
2118 Streamer.EmitInt8(dwarf::DW_OP_plus_uconst, "DW_OP_plus_uconst");
2119 Streamer.EmitSLEB128(DV.getAddrElement(1));
2121 // If first address element is OpPlus then emit
2122 // DW_OP_breg + Offset instead of DW_OP_reg + Offset.
2123 MachineLocation TLoc(Loc.getReg(), DV.getAddrElement(1));
2124 Asm->EmitDwarfRegOp(Streamer, TLoc, DV.isIndirect());
2128 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2131 // Emit remaining complex address elements.
2132 for (; i < N; ++i) {
2133 uint64_t Element = DV.getAddrElement(i);
2134 if (Element == DIBuilder::OpPlus) {
2135 Streamer.EmitInt8(dwarf::DW_OP_plus_uconst, "DW_OP_plus_uconst");
2136 Streamer.EmitULEB128(DV.getAddrElement(++i));
2137 } else if (Element == DIBuilder::OpDeref) {
2139 Streamer.EmitInt8(dwarf::DW_OP_deref, "DW_OP_deref");
2141 llvm_unreachable("unknown Opcode found in complex address");
2145 // else ... ignore constant fp. There is not any good way to
2146 // to represent them here in dwarf.
2150 void DwarfDebug::emitDebugLocEntryLocation(const DebugLocEntry &Entry) {
2151 Asm->OutStreamer.AddComment("Loc expr size");
2152 MCSymbol *begin = Asm->OutStreamer.getContext().CreateTempSymbol();
2153 MCSymbol *end = Asm->OutStreamer.getContext().CreateTempSymbol();
2154 Asm->EmitLabelDifference(end, begin, 2);
2155 Asm->OutStreamer.EmitLabel(begin);
2157 APByteStreamer Streamer(*Asm);
2158 emitDebugLocEntry(Streamer, Entry);
2160 Asm->OutStreamer.EmitLabel(end);
2163 // Emit locations into the debug loc section.
2164 void DwarfDebug::emitDebugLoc() {
2165 // Start the dwarf loc section.
2166 Asm->OutStreamer.SwitchSection(
2167 Asm->getObjFileLowering().getDwarfLocSection());
2168 unsigned char Size = Asm->getDataLayout().getPointerSize();
2169 for (const auto &DebugLoc : DotDebugLocEntries) {
2170 Asm->OutStreamer.EmitLabel(DebugLoc.Label);
2171 for (const auto &Entry : DebugLoc.List) {
2172 // Set up the range. This range is relative to the entry point of the
2173 // compile unit. This is a hard coded 0 for low_pc when we're emitting
2174 // ranges, or the DW_AT_low_pc on the compile unit otherwise.
2175 const DwarfCompileUnit *CU = Entry.getCU();
2176 if (CU->getRanges().size() == 1) {
2177 // Grab the begin symbol from the first range as our base.
2178 const MCSymbol *Base = CU->getRanges()[0].getStart();
2179 Asm->EmitLabelDifference(Entry.getBeginSym(), Base, Size);
2180 Asm->EmitLabelDifference(Entry.getEndSym(), Base, Size);
2182 Asm->OutStreamer.EmitSymbolValue(Entry.getBeginSym(), Size);
2183 Asm->OutStreamer.EmitSymbolValue(Entry.getEndSym(), Size);
2186 emitDebugLocEntryLocation(Entry);
2188 Asm->OutStreamer.EmitIntValue(0, Size);
2189 Asm->OutStreamer.EmitIntValue(0, Size);
2193 void DwarfDebug::emitDebugLocDWO() {
2194 Asm->OutStreamer.SwitchSection(
2195 Asm->getObjFileLowering().getDwarfLocDWOSection());
2196 for (const auto &DebugLoc : DotDebugLocEntries) {
2197 Asm->OutStreamer.EmitLabel(DebugLoc.Label);
2198 for (const auto &Entry : DebugLoc.List) {
2199 // Just always use start_length for now - at least that's one address
2200 // rather than two. We could get fancier and try to, say, reuse an
2201 // address we know we've emitted elsewhere (the start of the function?
2202 // The start of the CU or CU subrange that encloses this range?)
2203 Asm->EmitInt8(dwarf::DW_LLE_start_length_entry);
2204 unsigned idx = AddrPool.getIndex(Entry.getBeginSym());
2205 Asm->EmitULEB128(idx);
2206 Asm->EmitLabelDifference(Entry.getEndSym(), Entry.getBeginSym(), 4);
2208 emitDebugLocEntryLocation(Entry);
2210 Asm->EmitInt8(dwarf::DW_LLE_end_of_list_entry);
2215 const MCSymbol *Start, *End;
2218 // Emit a debug aranges section, containing a CU lookup for any
2219 // address we can tie back to a CU.
2220 void DwarfDebug::emitDebugARanges() {
2221 // Start the dwarf aranges section.
2222 Asm->OutStreamer.SwitchSection(
2223 Asm->getObjFileLowering().getDwarfARangesSection());
2225 typedef DenseMap<DwarfCompileUnit *, std::vector<ArangeSpan>> SpansType;
2229 // Build a list of sections used.
2230 std::vector<const MCSection *> Sections;
2231 for (const auto &it : SectionMap) {
2232 const MCSection *Section = it.first;
2233 Sections.push_back(Section);
2236 // Sort the sections into order.
2237 // This is only done to ensure consistent output order across different runs.
2238 std::sort(Sections.begin(), Sections.end(), SectionSort);
2240 // Build a set of address spans, sorted by CU.
2241 for (const MCSection *Section : Sections) {
2242 SmallVector<SymbolCU, 8> &List = SectionMap[Section];
2243 if (List.size() < 2)
2246 // Sort the symbols by offset within the section.
2247 std::sort(List.begin(), List.end(),
2248 [&](const SymbolCU &A, const SymbolCU &B) {
2249 unsigned IA = A.Sym ? Asm->OutStreamer.GetSymbolOrder(A.Sym) : 0;
2250 unsigned IB = B.Sym ? Asm->OutStreamer.GetSymbolOrder(B.Sym) : 0;
2252 // Symbols with no order assigned should be placed at the end.
2253 // (e.g. section end labels)
2261 // If we have no section (e.g. common), just write out
2262 // individual spans for each symbol.
2264 for (const SymbolCU &Cur : List) {
2266 Span.Start = Cur.Sym;
2269 Spans[Cur.CU].push_back(Span);
2272 // Build spans between each label.
2273 const MCSymbol *StartSym = List[0].Sym;
2274 for (size_t n = 1, e = List.size(); n < e; n++) {
2275 const SymbolCU &Prev = List[n - 1];
2276 const SymbolCU &Cur = List[n];
2278 // Try and build the longest span we can within the same CU.
2279 if (Cur.CU != Prev.CU) {
2281 Span.Start = StartSym;
2283 Spans[Prev.CU].push_back(Span);
2290 unsigned PtrSize = Asm->getDataLayout().getPointerSize();
2292 // Build a list of CUs used.
2293 std::vector<DwarfCompileUnit *> CUs;
2294 for (const auto &it : Spans) {
2295 DwarfCompileUnit *CU = it.first;
2299 // Sort the CU list (again, to ensure consistent output order).
2300 std::sort(CUs.begin(), CUs.end(), [](const DwarfUnit *A, const DwarfUnit *B) {
2301 return A->getUniqueID() < B->getUniqueID();
2304 // Emit an arange table for each CU we used.
2305 for (DwarfCompileUnit *CU : CUs) {
2306 std::vector<ArangeSpan> &List = Spans[CU];
2308 // Emit size of content not including length itself.
2309 unsigned ContentSize =
2310 sizeof(int16_t) + // DWARF ARange version number
2311 sizeof(int32_t) + // Offset of CU in the .debug_info section
2312 sizeof(int8_t) + // Pointer Size (in bytes)
2313 sizeof(int8_t); // Segment Size (in bytes)
2315 unsigned TupleSize = PtrSize * 2;
2317 // 7.20 in the Dwarf specs requires the table to be aligned to a tuple.
2319 OffsetToAlignment(sizeof(int32_t) + ContentSize, TupleSize);
2321 ContentSize += Padding;
2322 ContentSize += (List.size() + 1) * TupleSize;
2324 // For each compile unit, write the list of spans it covers.
2325 Asm->OutStreamer.AddComment("Length of ARange Set");
2326 Asm->EmitInt32(ContentSize);
2327 Asm->OutStreamer.AddComment("DWARF Arange version number");
2328 Asm->EmitInt16(dwarf::DW_ARANGES_VERSION);
2329 Asm->OutStreamer.AddComment("Offset Into Debug Info Section");
2330 Asm->EmitSectionOffset(CU->getLocalLabelBegin(), CU->getLocalSectionSym());
2331 Asm->OutStreamer.AddComment("Address Size (in bytes)");
2332 Asm->EmitInt8(PtrSize);
2333 Asm->OutStreamer.AddComment("Segment Size (in bytes)");
2336 Asm->OutStreamer.EmitFill(Padding, 0xff);
2338 for (const ArangeSpan &Span : List) {
2339 Asm->EmitLabelReference(Span.Start, PtrSize);
2341 // Calculate the size as being from the span start to it's end.
2343 Asm->EmitLabelDifference(Span.End, Span.Start, PtrSize);
2345 // For symbols without an end marker (e.g. common), we
2346 // write a single arange entry containing just that one symbol.
2347 uint64_t Size = SymSize[Span.Start];
2351 Asm->OutStreamer.EmitIntValue(Size, PtrSize);
2355 Asm->OutStreamer.AddComment("ARange terminator");
2356 Asm->OutStreamer.EmitIntValue(0, PtrSize);
2357 Asm->OutStreamer.EmitIntValue(0, PtrSize);
2361 // Emit visible names into a debug ranges section.
2362 void DwarfDebug::emitDebugRanges() {
2363 // Start the dwarf ranges section.
2364 Asm->OutStreamer.SwitchSection(
2365 Asm->getObjFileLowering().getDwarfRangesSection());
2367 // Size for our labels.
2368 unsigned char Size = Asm->getDataLayout().getPointerSize();
2370 // Grab the specific ranges for the compile units in the module.
2371 for (const auto &I : CUMap) {
2372 DwarfCompileUnit *TheCU = I.second;
2374 // Iterate over the misc ranges for the compile units in the module.
2375 for (const RangeSpanList &List : TheCU->getRangeLists()) {
2376 // Emit our symbol so we can find the beginning of the range.
2377 Asm->OutStreamer.EmitLabel(List.getSym());
2379 for (const RangeSpan &Range : List.getRanges()) {
2380 const MCSymbol *Begin = Range.getStart();
2381 const MCSymbol *End = Range.getEnd();
2382 assert(Begin && "Range without a begin symbol?");
2383 assert(End && "Range without an end symbol?");
2384 if (TheCU->getRanges().size() == 1) {
2385 // Grab the begin symbol from the first range as our base.
2386 const MCSymbol *Base = TheCU->getRanges()[0].getStart();
2387 Asm->EmitLabelDifference(Begin, Base, Size);
2388 Asm->EmitLabelDifference(End, Base, Size);
2390 Asm->OutStreamer.EmitSymbolValue(Begin, Size);
2391 Asm->OutStreamer.EmitSymbolValue(End, Size);
2395 // And terminate the list with two 0 values.
2396 Asm->OutStreamer.EmitIntValue(0, Size);
2397 Asm->OutStreamer.EmitIntValue(0, Size);
2400 // Now emit a range for the CU itself.
2401 if (TheCU->getRanges().size() > 1) {
2402 Asm->OutStreamer.EmitLabel(
2403 Asm->GetTempSymbol("cu_ranges", TheCU->getUniqueID()));
2404 for (const RangeSpan &Range : TheCU->getRanges()) {
2405 const MCSymbol *Begin = Range.getStart();
2406 const MCSymbol *End = Range.getEnd();
2407 assert(Begin && "Range without a begin symbol?");
2408 assert(End && "Range without an end symbol?");
2409 Asm->OutStreamer.EmitSymbolValue(Begin, Size);
2410 Asm->OutStreamer.EmitSymbolValue(End, Size);
2412 // And terminate the list with two 0 values.
2413 Asm->OutStreamer.EmitIntValue(0, Size);
2414 Asm->OutStreamer.EmitIntValue(0, Size);
2419 // DWARF5 Experimental Separate Dwarf emitters.
2421 void DwarfDebug::initSkeletonUnit(const DwarfUnit &U, DIE &Die,
2422 std::unique_ptr<DwarfUnit> NewU) {
2423 NewU->addLocalString(Die, dwarf::DW_AT_GNU_dwo_name,
2424 U.getCUNode().getSplitDebugFilename());
2426 if (!CompilationDir.empty())
2427 NewU->addLocalString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
2429 addGnuPubAttributes(*NewU, Die);
2431 SkeletonHolder.addUnit(std::move(NewU));
2434 // This DIE has the following attributes: DW_AT_comp_dir, DW_AT_stmt_list,
2435 // DW_AT_low_pc, DW_AT_high_pc, DW_AT_ranges, DW_AT_dwo_name, DW_AT_dwo_id,
2436 // DW_AT_addr_base, DW_AT_ranges_base.
2437 DwarfCompileUnit &DwarfDebug::constructSkeletonCU(const DwarfCompileUnit &CU) {
2439 auto OwnedUnit = make_unique<DwarfCompileUnit>(
2440 CU.getUniqueID(), CU.getCUNode(), Asm, this, &SkeletonHolder);
2441 DwarfCompileUnit &NewCU = *OwnedUnit;
2442 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoSection(),
2443 DwarfInfoSectionSym);
2445 NewCU.initStmtList(DwarfLineSectionSym);
2447 initSkeletonUnit(CU, NewCU.getUnitDie(), std::move(OwnedUnit));
2452 // This DIE has the following attributes: DW_AT_comp_dir, DW_AT_dwo_name,
2454 DwarfTypeUnit &DwarfDebug::constructSkeletonTU(DwarfTypeUnit &TU) {
2455 DwarfCompileUnit &CU = static_cast<DwarfCompileUnit &>(
2456 *SkeletonHolder.getUnits()[TU.getCU().getUniqueID()]);
2458 auto OwnedUnit = make_unique<DwarfTypeUnit>(TU.getUniqueID(), CU, Asm, this,
2460 DwarfTypeUnit &NewTU = *OwnedUnit;
2461 NewTU.setTypeSignature(TU.getTypeSignature());
2462 NewTU.setType(nullptr);
2464 Asm->getObjFileLowering().getDwarfTypesSection(TU.getTypeSignature()));
2466 initSkeletonUnit(TU, NewTU.getUnitDie(), std::move(OwnedUnit));
2470 // Emit the .debug_info.dwo section for separated dwarf. This contains the
2471 // compile units that would normally be in debug_info.
2472 void DwarfDebug::emitDebugInfoDWO() {
2473 assert(useSplitDwarf() && "No split dwarf debug info?");
2474 // Don't pass an abbrev symbol, using a constant zero instead so as not to
2475 // emit relocations into the dwo file.
2476 InfoHolder.emitUnits(this, /* AbbrevSymbol */ nullptr);
2479 // Emit the .debug_abbrev.dwo section for separated dwarf. This contains the
2480 // abbreviations for the .debug_info.dwo section.
2481 void DwarfDebug::emitDebugAbbrevDWO() {
2482 assert(useSplitDwarf() && "No split dwarf?");
2483 InfoHolder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevDWOSection());
2486 void DwarfDebug::emitDebugLineDWO() {
2487 assert(useSplitDwarf() && "No split dwarf?");
2488 Asm->OutStreamer.SwitchSection(
2489 Asm->getObjFileLowering().getDwarfLineDWOSection());
2490 SplitTypeUnitFileTable.Emit(Asm->OutStreamer);
2493 // Emit the .debug_str.dwo section for separated dwarf. This contains the
2494 // string section and is identical in format to traditional .debug_str
2496 void DwarfDebug::emitDebugStrDWO() {
2497 assert(useSplitDwarf() && "No split dwarf?");
2498 const MCSection *OffSec =
2499 Asm->getObjFileLowering().getDwarfStrOffDWOSection();
2500 const MCSymbol *StrSym = DwarfStrSectionSym;
2501 InfoHolder.emitStrings(Asm->getObjFileLowering().getDwarfStrDWOSection(),
2505 MCDwarfDwoLineTable *DwarfDebug::getDwoLineTable(const DwarfCompileUnit &CU) {
2506 if (!useSplitDwarf())
2509 SplitTypeUnitFileTable.setCompilationDir(CU.getCUNode().getDirectory());
2510 return &SplitTypeUnitFileTable;
2513 static uint64_t makeTypeSignature(StringRef Identifier) {
2515 Hash.update(Identifier);
2516 // ... take the least significant 8 bytes and return those. Our MD5
2517 // implementation always returns its results in little endian, swap bytes
2519 MD5::MD5Result Result;
2521 return *reinterpret_cast<support::ulittle64_t *>(Result + 8);
2524 void DwarfDebug::addDwarfTypeUnitType(DwarfCompileUnit &CU,
2525 StringRef Identifier, DIE &RefDie,
2526 DICompositeType CTy) {
2527 // Fast path if we're building some type units and one has already used the
2528 // address pool we know we're going to throw away all this work anyway, so
2529 // don't bother building dependent types.
2530 if (!TypeUnitsUnderConstruction.empty() && AddrPool.hasBeenUsed())
2533 const DwarfTypeUnit *&TU = DwarfTypeUnits[CTy];
2535 CU.addDIETypeSignature(RefDie, *TU);
2539 bool TopLevelType = TypeUnitsUnderConstruction.empty();
2540 AddrPool.resetUsedFlag();
2543 make_unique<DwarfTypeUnit>(InfoHolder.getUnits().size(), CU, Asm, this,
2544 &InfoHolder, getDwoLineTable(CU));
2545 DwarfTypeUnit &NewTU = *OwnedUnit;
2546 DIE &UnitDie = NewTU.getUnitDie();
2548 TypeUnitsUnderConstruction.push_back(
2549 std::make_pair(std::move(OwnedUnit), CTy));
2551 NewTU.addUInt(UnitDie, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
2554 uint64_t Signature = makeTypeSignature(Identifier);
2555 NewTU.setTypeSignature(Signature);
2557 if (!useSplitDwarf())
2558 CU.applyStmtList(UnitDie);
2562 ? Asm->getObjFileLowering().getDwarfTypesDWOSection(Signature)
2563 : Asm->getObjFileLowering().getDwarfTypesSection(Signature));
2565 NewTU.setType(NewTU.createTypeDIE(CTy));
2568 auto TypeUnitsToAdd = std::move(TypeUnitsUnderConstruction);
2569 TypeUnitsUnderConstruction.clear();
2571 // Types referencing entries in the address table cannot be placed in type
2573 if (AddrPool.hasBeenUsed()) {
2575 // Remove all the types built while building this type.
2576 // This is pessimistic as some of these types might not be dependent on
2577 // the type that used an address.
2578 for (const auto &TU : TypeUnitsToAdd)
2579 DwarfTypeUnits.erase(TU.second);
2581 // Construct this type in the CU directly.
2582 // This is inefficient because all the dependent types will be rebuilt
2583 // from scratch, including building them in type units, discovering that
2584 // they depend on addresses, throwing them out and rebuilding them.
2585 CU.constructTypeDIE(RefDie, CTy);
2589 // If the type wasn't dependent on fission addresses, finish adding the type
2590 // and all its dependent types.
2591 for (auto &TU : TypeUnitsToAdd) {
2592 if (useSplitDwarf())
2593 TU.first->setSkeleton(constructSkeletonTU(*TU.first));
2594 InfoHolder.addUnit(std::move(TU.first));
2597 CU.addDIETypeSignature(RefDie, NewTU);
2600 void DwarfDebug::attachLowHighPC(DwarfCompileUnit &Unit, DIE &D,
2601 MCSymbol *Begin, MCSymbol *End) {
2602 Unit.addLabelAddress(D, dwarf::DW_AT_low_pc, Begin);
2603 if (DwarfVersion < 4)
2604 Unit.addLabelAddress(D, dwarf::DW_AT_high_pc, End);
2606 Unit.addLabelDelta(D, dwarf::DW_AT_high_pc, End, Begin);
2609 // Accelerator table mutators - add each name along with its companion
2610 // DIE to the proper table while ensuring that the name that we're going
2611 // to reference is in the string table. We do this since the names we
2612 // add may not only be identical to the names in the DIE.
2613 void DwarfDebug::addAccelName(StringRef Name, const DIE &Die) {
2614 if (!useDwarfAccelTables())
2616 AccelNames.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2620 void DwarfDebug::addAccelObjC(StringRef Name, const DIE &Die) {
2621 if (!useDwarfAccelTables())
2623 AccelObjC.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2627 void DwarfDebug::addAccelNamespace(StringRef Name, const DIE &Die) {
2628 if (!useDwarfAccelTables())
2630 AccelNamespace.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2634 void DwarfDebug::addAccelType(StringRef Name, const DIE &Die, char Flags) {
2635 if (!useDwarfAccelTables())
2637 AccelTypes.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),