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);
328 } else if (!SP.getFunctionDeclaration()) {
329 // There is not any need to generate specification DIE for a function
330 // defined at compile unit level. If a function is defined inside another
331 // function then gdb prefers the definition at top level and but does not
332 // expect specification DIE in parent function. So avoid creating
333 // specification DIE for a function defined inside a function.
334 DIScope SPContext = resolve(SP.getContext());
335 if (SP.isDefinition() && !SPContext.isCompileUnit() &&
336 !SPContext.isFile() && !isSubprogramContext(SPContext)) {
337 SPCU.addFlag(*SPDie, dwarf::DW_AT_declaration);
340 DICompositeType SPTy = SP.getType();
341 DIArray Args = SPTy.getTypeArray();
342 uint16_t SPTag = SPTy.getTag();
343 if (SPTag == dwarf::DW_TAG_subroutine_type)
344 SPCU.constructSubprogramArguments(*SPDie, Args);
345 DIE *SPDeclDie = SPDie;
347 &SPCU.createAndAddDIE(dwarf::DW_TAG_subprogram, SPCU.getUnitDie());
348 SPCU.addDIEEntry(*SPDie, dwarf::DW_AT_specification, *SPDeclDie);
352 attachLowHighPC(SPCU, *SPDie, FunctionBeginSym, FunctionEndSym);
354 const TargetRegisterInfo *RI = Asm->TM.getRegisterInfo();
355 MachineLocation Location(RI->getFrameRegister(*Asm->MF));
356 SPCU.addAddress(*SPDie, dwarf::DW_AT_frame_base, Location);
358 // Add name to the name table, we do this here because we're guaranteed
359 // to have concrete versions of our DW_TAG_subprogram nodes.
360 addSubprogramNames(SP, *SPDie);
365 /// Check whether we should create a DIE for the given Scope, return true
366 /// if we don't create a DIE (the corresponding DIE is null).
367 bool DwarfDebug::isLexicalScopeDIENull(LexicalScope *Scope) {
368 if (Scope->isAbstractScope())
371 // We don't create a DIE if there is no Range.
372 const SmallVectorImpl<InsnRange> &Ranges = Scope->getRanges();
376 if (Ranges.size() > 1)
379 // We don't create a DIE if we have a single Range and the end label
381 SmallVectorImpl<InsnRange>::const_iterator RI = Ranges.begin();
382 MCSymbol *End = getLabelAfterInsn(RI->second);
386 static void addSectionLabel(AsmPrinter &Asm, DwarfUnit &U, DIE &D,
387 dwarf::Attribute A, const MCSymbol *L,
388 const MCSymbol *Sec) {
389 if (Asm.MAI->doesDwarfUseRelocationsAcrossSections())
390 U.addSectionLabel(D, A, L);
392 U.addSectionDelta(D, A, L, Sec);
395 void DwarfDebug::addScopeRangeList(DwarfCompileUnit &TheCU, DIE &ScopeDIE,
396 const SmallVectorImpl<InsnRange> &Range) {
397 // Emit offset in .debug_range as a relocatable label. emitDIE will handle
398 // emitting it appropriately.
399 MCSymbol *RangeSym = Asm->GetTempSymbol("debug_ranges", GlobalRangeCount++);
401 // Under fission, ranges are specified by constant offsets relative to the
402 // CU's DW_AT_GNU_ranges_base.
404 TheCU.addSectionDelta(ScopeDIE, dwarf::DW_AT_ranges, RangeSym,
405 DwarfDebugRangeSectionSym);
407 addSectionLabel(*Asm, TheCU, ScopeDIE, dwarf::DW_AT_ranges, RangeSym,
408 DwarfDebugRangeSectionSym);
410 RangeSpanList List(RangeSym);
411 for (const InsnRange &R : Range) {
412 RangeSpan Span(getLabelBeforeInsn(R.first), getLabelAfterInsn(R.second));
413 List.addRange(std::move(Span));
416 // Add the range list to the set of ranges to be emitted.
417 TheCU.addRangeList(std::move(List));
420 // Construct new DW_TAG_lexical_block for this scope and attach
421 // DW_AT_low_pc/DW_AT_high_pc labels.
423 DwarfDebug::constructLexicalScopeDIE(DwarfCompileUnit &TheCU,
424 LexicalScope *Scope) {
425 if (isLexicalScopeDIENull(Scope))
428 auto ScopeDIE = make_unique<DIE>(dwarf::DW_TAG_lexical_block);
429 if (Scope->isAbstractScope())
432 const SmallVectorImpl<InsnRange> &ScopeRanges = Scope->getRanges();
434 // If we have multiple ranges, emit them into the range section.
435 if (ScopeRanges.size() > 1) {
436 addScopeRangeList(TheCU, *ScopeDIE, ScopeRanges);
440 // Construct the address range for this DIE.
441 SmallVectorImpl<InsnRange>::const_iterator RI = ScopeRanges.begin();
442 MCSymbol *Start = getLabelBeforeInsn(RI->first);
443 MCSymbol *End = getLabelAfterInsn(RI->second);
444 assert(End && "End label should not be null!");
446 assert(Start->isDefined() && "Invalid starting label for an inlined scope!");
447 assert(End->isDefined() && "Invalid end label for an inlined scope!");
449 attachLowHighPC(TheCU, *ScopeDIE, Start, End);
454 // This scope represents inlined body of a function. Construct DIE to
455 // represent this concrete inlined copy of the function.
457 DwarfDebug::constructInlinedScopeDIE(DwarfCompileUnit &TheCU,
458 LexicalScope *Scope) {
459 const SmallVectorImpl<InsnRange> &ScopeRanges = Scope->getRanges();
460 assert(!ScopeRanges.empty() &&
461 "LexicalScope does not have instruction markers!");
463 assert(Scope->getScopeNode());
464 DIScope DS(Scope->getScopeNode());
465 DISubprogram InlinedSP = getDISubprogram(DS);
466 DIE *OriginDIE = TheCU.getDIE(InlinedSP);
467 // FIXME: This should be an assert (or possibly a
468 // getOrCreateSubprogram(InlinedSP)) otherwise we're just failing to emit
469 // inlining information.
471 DEBUG(dbgs() << "Unable to find original DIE for an inlined subprogram.");
475 auto ScopeDIE = make_unique<DIE>(dwarf::DW_TAG_inlined_subroutine);
476 TheCU.addDIEEntry(*ScopeDIE, dwarf::DW_AT_abstract_origin, *OriginDIE);
478 // If we have multiple ranges, emit them into the range section.
479 if (ScopeRanges.size() > 1)
480 addScopeRangeList(TheCU, *ScopeDIE, ScopeRanges);
482 SmallVectorImpl<InsnRange>::const_iterator RI = ScopeRanges.begin();
483 MCSymbol *StartLabel = getLabelBeforeInsn(RI->first);
484 MCSymbol *EndLabel = getLabelAfterInsn(RI->second);
486 if (!StartLabel || !EndLabel)
487 llvm_unreachable("Unexpected Start and End labels for an inlined scope!");
489 assert(StartLabel->isDefined() &&
490 "Invalid starting label for an inlined scope!");
491 assert(EndLabel->isDefined() && "Invalid end label for an inlined scope!");
493 attachLowHighPC(TheCU, *ScopeDIE, StartLabel, EndLabel);
496 InlinedSubprogramDIEs.insert(OriginDIE);
497 TheCU.addUInt(*OriginDIE, dwarf::DW_AT_inline, None, dwarf::DW_INL_inlined);
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 static std::unique_ptr<DIE> constructVariableDIE(DwarfCompileUnit &TheCU,
514 const LexicalScope &Scope,
515 DIE *&ObjectPointer) {
516 AbstractOrInlined AOI = AOI_None;
517 if (Scope.isAbstractScope())
519 else if (Scope.getInlinedAt())
521 auto Var = TheCU.constructVariableDIE(DV, AOI);
522 if (DV.isObjectPointer())
523 ObjectPointer = Var.get();
527 DIE *DwarfDebug::createScopeChildrenDIE(
528 DwarfCompileUnit &TheCU, LexicalScope *Scope,
529 SmallVectorImpl<std::unique_ptr<DIE>> &Children) {
530 DIE *ObjectPointer = nullptr;
532 // Collect arguments for current function.
533 if (LScopes.isCurrentFunctionScope(Scope)) {
534 for (DbgVariable *ArgDV : CurrentFnArguments)
537 constructVariableDIE(TheCU, *ArgDV, *Scope, ObjectPointer));
539 // If this is a variadic function, add an unspecified parameter.
540 DISubprogram SP(Scope->getScopeNode());
541 DIArray FnArgs = SP.getType().getTypeArray();
542 if (FnArgs.getElement(FnArgs.getNumElements() - 1)
543 .isUnspecifiedParameter()) {
545 make_unique<DIE>(dwarf::DW_TAG_unspecified_parameters));
549 // Collect lexical scope children first.
550 for (DbgVariable *DV : ScopeVariables.lookup(Scope))
551 Children.push_back(constructVariableDIE(TheCU, *DV, *Scope, ObjectPointer));
553 for (LexicalScope *LS : Scope->getChildren())
554 if (std::unique_ptr<DIE> Nested = constructScopeDIE(TheCU, LS))
555 Children.push_back(std::move(Nested));
556 return ObjectPointer;
559 void DwarfDebug::createAndAddScopeChildren(DwarfCompileUnit &TheCU,
560 LexicalScope *Scope, DIE &ScopeDIE) {
561 // We create children when the scope DIE is not null.
562 SmallVector<std::unique_ptr<DIE>, 8> Children;
563 if (DIE *ObjectPointer = createScopeChildrenDIE(TheCU, Scope, Children))
564 TheCU.addDIEEntry(ScopeDIE, dwarf::DW_AT_object_pointer, *ObjectPointer);
567 for (auto &I : Children)
568 ScopeDIE.addChild(std::move(I));
571 void DwarfDebug::constructAbstractSubprogramScopeDIE(DwarfCompileUnit &TheCU,
572 LexicalScope *Scope) {
573 assert(Scope && Scope->getScopeNode());
574 assert(Scope->isAbstractScope());
575 assert(!Scope->getInlinedAt());
577 DISubprogram Sub(Scope->getScopeNode());
579 if (!ProcessedSPNodes.insert(Sub))
582 if (DIE *ScopeDIE = TheCU.getDIE(Sub)) {
583 AbstractSPDies.insert(std::make_pair(Sub, ScopeDIE));
584 TheCU.addUInt(*ScopeDIE, dwarf::DW_AT_inline, None, dwarf::DW_INL_inlined);
585 createAndAddScopeChildren(TheCU, Scope, *ScopeDIE);
589 DIE &DwarfDebug::constructSubprogramScopeDIE(DwarfCompileUnit &TheCU,
590 LexicalScope *Scope) {
591 assert(Scope && Scope->getScopeNode());
592 assert(!Scope->getInlinedAt());
593 assert(!Scope->isAbstractScope());
594 DISubprogram Sub(Scope->getScopeNode());
596 assert(Sub.isSubprogram());
598 ProcessedSPNodes.insert(Sub);
600 DIE &ScopeDIE = updateSubprogramScopeDIE(TheCU, Sub);
602 createAndAddScopeChildren(TheCU, Scope, ScopeDIE);
607 // Construct a DIE for this scope.
608 std::unique_ptr<DIE> DwarfDebug::constructScopeDIE(DwarfCompileUnit &TheCU,
609 LexicalScope *Scope) {
610 if (!Scope || !Scope->getScopeNode())
613 DIScope DS(Scope->getScopeNode());
615 assert((Scope->getInlinedAt() || !DS.isSubprogram()) &&
616 "Only handle inlined subprograms here, use "
617 "constructSubprogramScopeDIE for non-inlined "
620 SmallVector<std::unique_ptr<DIE>, 8> Children;
622 // We try to create the scope DIE first, then the children DIEs. This will
623 // avoid creating un-used children then removing them later when we find out
624 // the scope DIE is null.
625 std::unique_ptr<DIE> ScopeDIE;
626 if (DS.getContext() && DS.isSubprogram()) {
627 ScopeDIE = constructInlinedScopeDIE(TheCU, Scope);
630 // We create children when the scope DIE is not null.
631 createScopeChildrenDIE(TheCU, Scope, Children);
633 // Early exit when we know the scope DIE is going to be null.
634 if (isLexicalScopeDIENull(Scope))
637 // We create children here when we know the scope DIE is not going to be
638 // null and the children will be added to the scope DIE.
639 createScopeChildrenDIE(TheCU, Scope, Children);
641 // There is no need to emit empty lexical block DIE.
642 std::pair<ImportedEntityMap::const_iterator,
643 ImportedEntityMap::const_iterator> Range =
644 std::equal_range(ScopesWithImportedEntities.begin(),
645 ScopesWithImportedEntities.end(),
646 std::pair<const MDNode *, const MDNode *>(DS, nullptr),
648 if (Children.empty() && Range.first == Range.second)
650 ScopeDIE = constructLexicalScopeDIE(TheCU, Scope);
651 assert(ScopeDIE && "Scope DIE should not be null.");
652 for (ImportedEntityMap::const_iterator i = Range.first; i != Range.second;
654 constructImportedEntityDIE(TheCU, i->second, *ScopeDIE);
658 for (auto &I : Children)
659 ScopeDIE->addChild(std::move(I));
664 void DwarfDebug::addGnuPubAttributes(DwarfUnit &U, DIE &D) const {
665 if (!GenerateGnuPubSections)
668 U.addFlag(D, dwarf::DW_AT_GNU_pubnames);
671 // Create new DwarfCompileUnit for the given metadata node with tag
672 // DW_TAG_compile_unit.
673 DwarfCompileUnit &DwarfDebug::constructDwarfCompileUnit(DICompileUnit DIUnit) {
674 StringRef FN = DIUnit.getFilename();
675 CompilationDir = DIUnit.getDirectory();
677 auto OwnedUnit = make_unique<DwarfCompileUnit>(
678 InfoHolder.getUnits().size(), DIUnit, Asm, this, &InfoHolder);
679 DwarfCompileUnit &NewCU = *OwnedUnit;
680 DIE &Die = NewCU.getUnitDie();
681 InfoHolder.addUnit(std::move(OwnedUnit));
683 // LTO with assembly output shares a single line table amongst multiple CUs.
684 // To avoid the compilation directory being ambiguous, let the line table
685 // explicitly describe the directory of all files, never relying on the
686 // compilation directory.
687 if (!Asm->OutStreamer.hasRawTextSupport() || SingleCU)
688 Asm->OutStreamer.getContext().setMCLineTableCompilationDir(
689 NewCU.getUniqueID(), CompilationDir);
691 NewCU.addString(Die, dwarf::DW_AT_producer, DIUnit.getProducer());
692 NewCU.addUInt(Die, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
693 DIUnit.getLanguage());
694 NewCU.addString(Die, dwarf::DW_AT_name, FN);
696 if (!useSplitDwarf()) {
697 NewCU.initStmtList(DwarfLineSectionSym);
699 // If we're using split dwarf the compilation dir is going to be in the
700 // skeleton CU and so we don't need to duplicate it here.
701 if (!CompilationDir.empty())
702 NewCU.addString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
704 addGnuPubAttributes(NewCU, Die);
707 if (DIUnit.isOptimized())
708 NewCU.addFlag(Die, dwarf::DW_AT_APPLE_optimized);
710 StringRef Flags = DIUnit.getFlags();
712 NewCU.addString(Die, dwarf::DW_AT_APPLE_flags, Flags);
714 if (unsigned RVer = DIUnit.getRunTimeVersion())
715 NewCU.addUInt(Die, dwarf::DW_AT_APPLE_major_runtime_vers,
716 dwarf::DW_FORM_data1, RVer);
721 if (useSplitDwarf()) {
722 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoDWOSection(),
723 DwarfInfoDWOSectionSym);
724 NewCU.setSkeleton(constructSkeletonCU(NewCU));
726 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoSection(),
727 DwarfInfoSectionSym);
729 CUMap.insert(std::make_pair(DIUnit, &NewCU));
730 CUDieMap.insert(std::make_pair(&Die, &NewCU));
734 // Construct subprogram DIE.
735 void DwarfDebug::constructSubprogramDIE(DwarfCompileUnit &TheCU,
737 // FIXME: We should only call this routine once, however, during LTO if a
738 // program is defined in multiple CUs we could end up calling it out of
739 // beginModule as we walk the CUs.
741 DwarfCompileUnit *&CURef = SPMap[N];
747 assert(SP.isSubprogram());
748 if (!SP.isDefinition())
749 // This is a method declaration which will be handled while constructing
753 DIE &SubprogramDie = *TheCU.getOrCreateSubprogramDIE(SP);
755 // Expose as a global name.
756 TheCU.addGlobalName(SP.getName(), SubprogramDie, resolve(SP.getContext()));
759 void DwarfDebug::constructImportedEntityDIE(DwarfCompileUnit &TheCU,
761 DIImportedEntity Module(N);
762 assert(Module.Verify());
763 if (DIE *D = TheCU.getOrCreateContextDIE(Module.getContext()))
764 constructImportedEntityDIE(TheCU, Module, *D);
767 void DwarfDebug::constructImportedEntityDIE(DwarfCompileUnit &TheCU,
768 const MDNode *N, DIE &Context) {
769 DIImportedEntity Module(N);
770 assert(Module.Verify());
771 return constructImportedEntityDIE(TheCU, Module, Context);
774 void DwarfDebug::constructImportedEntityDIE(DwarfCompileUnit &TheCU,
775 const DIImportedEntity &Module,
777 assert(Module.Verify() &&
778 "Use one of the MDNode * overloads to handle invalid metadata");
779 DIE &IMDie = TheCU.createAndAddDIE(Module.getTag(), Context, Module);
781 DIDescriptor Entity = resolve(Module.getEntity());
782 if (Entity.isNameSpace())
783 EntityDie = TheCU.getOrCreateNameSpace(DINameSpace(Entity));
784 else if (Entity.isSubprogram())
785 EntityDie = TheCU.getOrCreateSubprogramDIE(DISubprogram(Entity));
786 else if (Entity.isType())
787 EntityDie = TheCU.getOrCreateTypeDIE(DIType(Entity));
789 EntityDie = TheCU.getDIE(Entity);
790 TheCU.addSourceLine(IMDie, Module.getLineNumber(),
791 Module.getContext().getFilename(),
792 Module.getContext().getDirectory());
793 TheCU.addDIEEntry(IMDie, dwarf::DW_AT_import, *EntityDie);
794 StringRef Name = Module.getName();
796 TheCU.addString(IMDie, dwarf::DW_AT_name, Name);
799 // Emit all Dwarf sections that should come prior to the content. Create
800 // global DIEs and emit initial debug info sections. This is invoked by
801 // the target AsmPrinter.
802 void DwarfDebug::beginModule() {
803 if (DisableDebugInfoPrinting)
806 const Module *M = MMI->getModule();
808 // If module has named metadata anchors then use them, otherwise scan the
809 // module using debug info finder to collect debug info.
810 NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
813 TypeIdentifierMap = generateDITypeIdentifierMap(CU_Nodes);
815 // Emit initial sections so we can reference labels later.
818 SingleCU = CU_Nodes->getNumOperands() == 1;
820 for (MDNode *N : CU_Nodes->operands()) {
821 DICompileUnit CUNode(N);
822 DwarfCompileUnit &CU = constructDwarfCompileUnit(CUNode);
823 DIArray ImportedEntities = CUNode.getImportedEntities();
824 for (unsigned i = 0, e = ImportedEntities.getNumElements(); i != e; ++i)
825 ScopesWithImportedEntities.push_back(std::make_pair(
826 DIImportedEntity(ImportedEntities.getElement(i)).getContext(),
827 ImportedEntities.getElement(i)));
828 std::sort(ScopesWithImportedEntities.begin(),
829 ScopesWithImportedEntities.end(), less_first());
830 DIArray GVs = CUNode.getGlobalVariables();
831 for (unsigned i = 0, e = GVs.getNumElements(); i != e; ++i)
832 CU.createGlobalVariableDIE(DIGlobalVariable(GVs.getElement(i)));
833 DIArray SPs = CUNode.getSubprograms();
834 for (unsigned i = 0, e = SPs.getNumElements(); i != e; ++i)
835 constructSubprogramDIE(CU, SPs.getElement(i));
836 DIArray EnumTypes = CUNode.getEnumTypes();
837 for (unsigned i = 0, e = EnumTypes.getNumElements(); i != e; ++i)
838 CU.getOrCreateTypeDIE(EnumTypes.getElement(i));
839 DIArray RetainedTypes = CUNode.getRetainedTypes();
840 for (unsigned i = 0, e = RetainedTypes.getNumElements(); i != e; ++i) {
841 DIType Ty(RetainedTypes.getElement(i));
842 // The retained types array by design contains pointers to
843 // MDNodes rather than DIRefs. Unique them here.
844 DIType UniqueTy(resolve(Ty.getRef()));
845 CU.getOrCreateTypeDIE(UniqueTy);
847 // Emit imported_modules last so that the relevant context is already
849 for (unsigned i = 0, e = ImportedEntities.getNumElements(); i != e; ++i)
850 constructImportedEntityDIE(CU, ImportedEntities.getElement(i));
853 // Tell MMI that we have debug info.
854 MMI->setDebugInfoAvailability(true);
856 // Prime section data.
857 SectionMap[Asm->getObjFileLowering().getTextSection()];
860 // Collect info for variables that were optimized out.
861 void DwarfDebug::collectDeadVariables() {
862 const Module *M = MMI->getModule();
864 if (NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu")) {
865 for (MDNode *N : CU_Nodes->operands()) {
866 DICompileUnit TheCU(N);
867 // Construct subprogram DIE and add variables DIEs.
868 DwarfCompileUnit *SPCU =
869 static_cast<DwarfCompileUnit *>(CUMap.lookup(TheCU));
870 assert(SPCU && "Unable to find Compile Unit!");
871 DIArray Subprograms = TheCU.getSubprograms();
872 for (unsigned i = 0, e = Subprograms.getNumElements(); i != e; ++i) {
873 DISubprogram SP(Subprograms.getElement(i));
874 if (ProcessedSPNodes.count(SP) != 0)
876 assert(SP.isSubprogram() &&
877 "CU's subprogram list contains a non-subprogram");
878 if (!SP.isDefinition())
880 DIArray Variables = SP.getVariables();
881 if (Variables.getNumElements() == 0)
884 // FIXME: See the comment in constructSubprogramDIE about duplicate
886 constructSubprogramDIE(*SPCU, SP);
887 DIE *SPDIE = SPCU->getDIE(SP);
888 for (unsigned vi = 0, ve = Variables.getNumElements(); vi != ve; ++vi) {
889 DIVariable DV(Variables.getElement(vi));
890 assert(DV.isVariable());
891 DbgVariable NewVar(DV, nullptr, this);
892 SPDIE->addChild(SPCU->constructVariableDIE(NewVar));
899 void DwarfDebug::finalizeModuleInfo() {
900 // Collect info for variables that were optimized out.
901 collectDeadVariables();
903 // Handle anything that needs to be done on a per-unit basis after
904 // all other generation.
905 for (const auto &TheU : getUnits()) {
906 // Emit DW_AT_containing_type attribute to connect types with their
907 // vtable holding type.
908 TheU->constructContainingTypeDIEs();
910 // Add CU specific attributes if we need to add any.
911 if (TheU->getUnitDie().getTag() == dwarf::DW_TAG_compile_unit) {
912 // If we're splitting the dwarf out now that we've got the entire
913 // CU then add the dwo id to it.
914 DwarfCompileUnit *SkCU =
915 static_cast<DwarfCompileUnit *>(TheU->getSkeleton());
916 if (useSplitDwarf()) {
917 // Emit a unique identifier for this CU.
918 uint64_t ID = DIEHash(Asm).computeCUSignature(TheU->getUnitDie());
919 TheU->addUInt(TheU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
920 dwarf::DW_FORM_data8, ID);
921 SkCU->addUInt(SkCU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
922 dwarf::DW_FORM_data8, ID);
924 // We don't keep track of which addresses are used in which CU so this
925 // is a bit pessimistic under LTO.
926 if (!AddrPool.isEmpty())
927 addSectionLabel(*Asm, *SkCU, SkCU->getUnitDie(),
928 dwarf::DW_AT_GNU_addr_base, DwarfAddrSectionSym,
929 DwarfAddrSectionSym);
930 if (!TheU->getRangeLists().empty())
931 addSectionLabel(*Asm, *SkCU, SkCU->getUnitDie(),
932 dwarf::DW_AT_GNU_ranges_base,
933 DwarfDebugRangeSectionSym, DwarfDebugRangeSectionSym);
936 // If we have code split among multiple sections or non-contiguous
937 // ranges of code then emit a DW_AT_ranges attribute on the unit that will
938 // remain in the .o file, otherwise add a DW_AT_low_pc.
939 // FIXME: We should use ranges allow reordering of code ala
940 // .subsections_via_symbols in mach-o. This would mean turning on
941 // ranges for all subprogram DIEs for mach-o.
942 DwarfCompileUnit &U =
943 SkCU ? *SkCU : static_cast<DwarfCompileUnit &>(*TheU);
944 unsigned NumRanges = TheU->getRanges().size();
947 addSectionLabel(*Asm, U, U.getUnitDie(), dwarf::DW_AT_ranges,
948 Asm->GetTempSymbol("cu_ranges", U.getUniqueID()),
949 DwarfDebugRangeSectionSym);
951 // A DW_AT_low_pc attribute may also be specified in combination with
952 // DW_AT_ranges to specify the default base address for use in
953 // location lists (see Section 2.6.2) and range lists (see Section
955 U.addUInt(U.getUnitDie(), dwarf::DW_AT_low_pc, dwarf::DW_FORM_addr,
958 RangeSpan &Range = TheU->getRanges().back();
959 U.addLocalLabelAddress(U.getUnitDie(), dwarf::DW_AT_low_pc,
961 U.addLabelDelta(U.getUnitDie(), dwarf::DW_AT_high_pc, Range.getEnd(),
968 // Compute DIE offsets and sizes.
969 InfoHolder.computeSizeAndOffsets();
971 SkeletonHolder.computeSizeAndOffsets();
974 void DwarfDebug::endSections() {
975 // Filter labels by section.
976 for (const SymbolCU &SCU : ArangeLabels) {
977 if (SCU.Sym->isInSection()) {
978 // Make a note of this symbol and it's section.
979 const MCSection *Section = &SCU.Sym->getSection();
980 if (!Section->getKind().isMetadata())
981 SectionMap[Section].push_back(SCU);
983 // Some symbols (e.g. common/bss on mach-o) can have no section but still
984 // appear in the output. This sucks as we rely on sections to build
985 // arange spans. We can do it without, but it's icky.
986 SectionMap[nullptr].push_back(SCU);
990 // Build a list of sections used.
991 std::vector<const MCSection *> Sections;
992 for (const auto &it : SectionMap) {
993 const MCSection *Section = it.first;
994 Sections.push_back(Section);
997 // Sort the sections into order.
998 // This is only done to ensure consistent output order across different runs.
999 std::sort(Sections.begin(), Sections.end(), SectionSort);
1001 // Add terminating symbols for each section.
1002 for (unsigned ID = 0, E = Sections.size(); ID != E; ID++) {
1003 const MCSection *Section = Sections[ID];
1004 MCSymbol *Sym = nullptr;
1007 // We can't call MCSection::getLabelEndName, as it's only safe to do so
1008 // if we know the section name up-front. For user-created sections, the
1009 // resulting label may not be valid to use as a label. (section names can
1010 // use a greater set of characters on some systems)
1011 Sym = Asm->GetTempSymbol("debug_end", ID);
1012 Asm->OutStreamer.SwitchSection(Section);
1013 Asm->OutStreamer.EmitLabel(Sym);
1016 // Insert a final terminator.
1017 SectionMap[Section].push_back(SymbolCU(nullptr, Sym));
1021 // Emit all Dwarf sections that should come after the content.
1022 void DwarfDebug::endModule() {
1023 assert(CurFn == nullptr);
1024 assert(CurMI == nullptr);
1029 // End any existing sections.
1030 // TODO: Does this need to happen?
1033 // Finalize the debug info for the module.
1034 finalizeModuleInfo();
1038 // Emit all the DIEs into a debug info section.
1041 // Corresponding abbreviations into a abbrev section.
1042 emitAbbreviations();
1044 // Emit info into a debug aranges section.
1045 if (GenerateARangeSection)
1048 // Emit info into a debug ranges section.
1051 if (useSplitDwarf()) {
1054 emitDebugAbbrevDWO();
1056 // Emit DWO addresses.
1057 AddrPool.emit(*Asm, Asm->getObjFileLowering().getDwarfAddrSection());
1060 // Emit info into a debug loc section.
1063 // Emit info into the dwarf accelerator table sections.
1064 if (useDwarfAccelTables()) {
1067 emitAccelNamespaces();
1071 // Emit the pubnames and pubtypes sections if requested.
1072 if (HasDwarfPubSections) {
1073 emitDebugPubNames(GenerateGnuPubSections);
1074 emitDebugPubTypes(GenerateGnuPubSections);
1080 // Reset these for the next Module if we have one.
1084 // Find abstract variable, if any, associated with Var.
1085 DbgVariable *DwarfDebug::findAbstractVariable(DIVariable &DV,
1086 DebugLoc ScopeLoc) {
1087 LLVMContext &Ctx = DV->getContext();
1088 // More then one inlined variable corresponds to one abstract variable.
1089 DIVariable Var = cleanseInlinedVariable(DV, Ctx);
1090 DbgVariable *AbsDbgVariable = AbstractVariables.lookup(Var);
1092 return AbsDbgVariable;
1094 LexicalScope *Scope = LScopes.findAbstractScope(ScopeLoc.getScope(Ctx));
1098 AbsDbgVariable = new DbgVariable(Var, nullptr, this);
1099 addScopeVariable(Scope, AbsDbgVariable);
1100 AbstractVariables[Var] = AbsDbgVariable;
1101 return AbsDbgVariable;
1104 // If Var is a current function argument then add it to CurrentFnArguments list.
1105 bool DwarfDebug::addCurrentFnArgument(DbgVariable *Var, LexicalScope *Scope) {
1106 if (!LScopes.isCurrentFunctionScope(Scope))
1108 DIVariable DV = Var->getVariable();
1109 if (DV.getTag() != dwarf::DW_TAG_arg_variable)
1111 unsigned ArgNo = DV.getArgNumber();
1115 size_t Size = CurrentFnArguments.size();
1117 CurrentFnArguments.resize(CurFn->getFunction()->arg_size());
1118 // llvm::Function argument size is not good indicator of how many
1119 // arguments does the function have at source level.
1121 CurrentFnArguments.resize(ArgNo * 2);
1122 CurrentFnArguments[ArgNo - 1] = Var;
1126 // Collect variable information from side table maintained by MMI.
1127 void DwarfDebug::collectVariableInfoFromMMITable(
1128 SmallPtrSet<const MDNode *, 16> &Processed) {
1129 for (const auto &VI : MMI->getVariableDbgInfo()) {
1132 Processed.insert(VI.Var);
1133 DIVariable DV(VI.Var);
1134 LexicalScope *Scope = LScopes.findLexicalScope(VI.Loc);
1136 // If variable scope is not found then skip this variable.
1140 DbgVariable *AbsDbgVariable = findAbstractVariable(DV, VI.Loc);
1141 DbgVariable *RegVar = new DbgVariable(DV, AbsDbgVariable, this);
1142 RegVar->setFrameIndex(VI.Slot);
1143 if (!addCurrentFnArgument(RegVar, Scope))
1144 addScopeVariable(Scope, RegVar);
1148 // Get .debug_loc entry for the instruction range starting at MI.
1149 static DebugLocEntry::Value getDebugLocValue(const MachineInstr *MI) {
1150 const MDNode *Var = MI->getDebugVariable();
1152 assert(MI->getNumOperands() == 3);
1153 if (MI->getOperand(0).isReg()) {
1154 MachineLocation MLoc;
1155 // If the second operand is an immediate, this is a
1156 // register-indirect address.
1157 if (!MI->getOperand(1).isImm())
1158 MLoc.set(MI->getOperand(0).getReg());
1160 MLoc.set(MI->getOperand(0).getReg(), MI->getOperand(1).getImm());
1161 return DebugLocEntry::Value(Var, MLoc);
1163 if (MI->getOperand(0).isImm())
1164 return DebugLocEntry::Value(Var, MI->getOperand(0).getImm());
1165 if (MI->getOperand(0).isFPImm())
1166 return DebugLocEntry::Value(Var, MI->getOperand(0).getFPImm());
1167 if (MI->getOperand(0).isCImm())
1168 return DebugLocEntry::Value(Var, MI->getOperand(0).getCImm());
1170 llvm_unreachable("Unexpected 3 operand DBG_VALUE instruction!");
1173 // Find variables for each lexical scope.
1175 DwarfDebug::collectVariableInfo(SmallPtrSet<const MDNode *, 16> &Processed) {
1176 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1177 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1179 // Grab the variable info that was squirreled away in the MMI side-table.
1180 collectVariableInfoFromMMITable(Processed);
1182 for (const auto &I : DbgValues) {
1183 DIVariable DV(I.first);
1184 if (Processed.count(DV))
1187 // History contains relevant DBG_VALUE instructions for DV and instructions
1189 const SmallVectorImpl<const MachineInstr *> &History = I.second;
1190 if (History.empty())
1192 const MachineInstr *MInsn = History.front();
1194 LexicalScope *Scope = nullptr;
1195 if (DV.getTag() == dwarf::DW_TAG_arg_variable &&
1196 DISubprogram(DV.getContext()).describes(CurFn->getFunction()))
1197 Scope = LScopes.getCurrentFunctionScope();
1198 else if (MDNode *IA = DV.getInlinedAt()) {
1199 DebugLoc DL = DebugLoc::getFromDILocation(IA);
1200 Scope = LScopes.findInlinedScope(DebugLoc::get(
1201 DL.getLine(), DL.getCol(), DV.getContext(), IA));
1203 Scope = LScopes.findLexicalScope(DV.getContext());
1204 // If variable scope is not found then skip this variable.
1208 Processed.insert(DV);
1209 assert(MInsn->isDebugValue() && "History must begin with debug value");
1210 DbgVariable *AbsVar = findAbstractVariable(DV, MInsn->getDebugLoc());
1211 DbgVariable *RegVar = new DbgVariable(DV, AbsVar, this);
1212 if (!addCurrentFnArgument(RegVar, Scope))
1213 addScopeVariable(Scope, RegVar);
1215 AbsVar->setMInsn(MInsn);
1217 // Simplify ranges that are fully coalesced.
1218 if (History.size() <= 1 ||
1219 (History.size() == 2 && MInsn->isIdenticalTo(History.back()))) {
1220 RegVar->setMInsn(MInsn);
1224 // Handle multiple DBG_VALUE instructions describing one variable.
1225 RegVar->setDotDebugLocOffset(DotDebugLocEntries.size());
1227 DotDebugLocEntries.resize(DotDebugLocEntries.size() + 1);
1228 DebugLocList &LocList = DotDebugLocEntries.back();
1230 Asm->GetTempSymbol("debug_loc", DotDebugLocEntries.size() - 1);
1231 SmallVector<DebugLocEntry, 4> &DebugLoc = LocList.List;
1232 for (SmallVectorImpl<const MachineInstr *>::const_iterator
1233 HI = History.begin(),
1236 const MachineInstr *Begin = *HI;
1237 assert(Begin->isDebugValue() && "Invalid History entry");
1239 // Check if DBG_VALUE is truncating a range.
1240 if (Begin->getNumOperands() > 1 && Begin->getOperand(0).isReg() &&
1241 !Begin->getOperand(0).getReg())
1244 // Compute the range for a register location.
1245 const MCSymbol *FLabel = getLabelBeforeInsn(Begin);
1246 const MCSymbol *SLabel = nullptr;
1249 // If Begin is the last instruction in History then its value is valid
1250 // until the end of the function.
1251 SLabel = FunctionEndSym;
1253 const MachineInstr *End = HI[1];
1254 DEBUG(dbgs() << "DotDebugLoc Pair:\n"
1255 << "\t" << *Begin << "\t" << *End << "\n");
1256 if (End->isDebugValue())
1257 SLabel = getLabelBeforeInsn(End);
1259 // End is a normal instruction clobbering the range.
1260 SLabel = getLabelAfterInsn(End);
1261 assert(SLabel && "Forgot label after clobber instruction");
1266 // The value is valid until the next DBG_VALUE or clobber.
1267 DebugLocEntry Loc(FLabel, SLabel, getDebugLocValue(Begin), TheCU);
1268 if (DebugLoc.empty() || !DebugLoc.back().Merge(Loc))
1269 DebugLoc.push_back(std::move(Loc));
1273 // Collect info for variables that were optimized out.
1274 DIArray Variables = DISubprogram(FnScope->getScopeNode()).getVariables();
1275 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1276 DIVariable DV(Variables.getElement(i));
1277 assert(DV.isVariable());
1278 if (!Processed.insert(DV))
1280 if (LexicalScope *Scope = LScopes.findLexicalScope(DV.getContext()))
1281 addScopeVariable(Scope, new DbgVariable(DV, nullptr, this));
1285 // Return Label preceding the instruction.
1286 MCSymbol *DwarfDebug::getLabelBeforeInsn(const MachineInstr *MI) {
1287 MCSymbol *Label = LabelsBeforeInsn.lookup(MI);
1288 assert(Label && "Didn't insert label before instruction");
1292 // Return Label immediately following the instruction.
1293 MCSymbol *DwarfDebug::getLabelAfterInsn(const MachineInstr *MI) {
1294 return LabelsAfterInsn.lookup(MI);
1297 // Process beginning of an instruction.
1298 void DwarfDebug::beginInstruction(const MachineInstr *MI) {
1299 assert(CurMI == nullptr);
1301 // Check if source location changes, but ignore DBG_VALUE locations.
1302 if (!MI->isDebugValue()) {
1303 DebugLoc DL = MI->getDebugLoc();
1304 if (DL != PrevInstLoc && (!DL.isUnknown() || UnknownLocations)) {
1307 if (DL == PrologEndLoc) {
1308 Flags |= DWARF2_FLAG_PROLOGUE_END;
1309 PrologEndLoc = DebugLoc();
1311 if (PrologEndLoc.isUnknown())
1312 Flags |= DWARF2_FLAG_IS_STMT;
1314 if (!DL.isUnknown()) {
1315 const MDNode *Scope = DL.getScope(Asm->MF->getFunction()->getContext());
1316 recordSourceLine(DL.getLine(), DL.getCol(), Scope, Flags);
1318 recordSourceLine(0, 0, nullptr, 0);
1322 // Insert labels where requested.
1323 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1324 LabelsBeforeInsn.find(MI);
1327 if (I == LabelsBeforeInsn.end())
1330 // Label already assigned.
1335 PrevLabel = MMI->getContext().CreateTempSymbol();
1336 Asm->OutStreamer.EmitLabel(PrevLabel);
1338 I->second = PrevLabel;
1341 // Process end of an instruction.
1342 void DwarfDebug::endInstruction() {
1343 assert(CurMI != nullptr);
1344 // Don't create a new label after DBG_VALUE instructions.
1345 // They don't generate code.
1346 if (!CurMI->isDebugValue())
1347 PrevLabel = nullptr;
1349 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1350 LabelsAfterInsn.find(CurMI);
1354 if (I == LabelsAfterInsn.end())
1357 // Label already assigned.
1361 // We need a label after this instruction.
1363 PrevLabel = MMI->getContext().CreateTempSymbol();
1364 Asm->OutStreamer.EmitLabel(PrevLabel);
1366 I->second = PrevLabel;
1369 // Each LexicalScope has first instruction and last instruction to mark
1370 // beginning and end of a scope respectively. Create an inverse map that list
1371 // scopes starts (and ends) with an instruction. One instruction may start (or
1372 // end) multiple scopes. Ignore scopes that are not reachable.
1373 void DwarfDebug::identifyScopeMarkers() {
1374 SmallVector<LexicalScope *, 4> WorkList;
1375 WorkList.push_back(LScopes.getCurrentFunctionScope());
1376 while (!WorkList.empty()) {
1377 LexicalScope *S = WorkList.pop_back_val();
1379 const SmallVectorImpl<LexicalScope *> &Children = S->getChildren();
1380 if (!Children.empty())
1381 WorkList.append(Children.begin(), Children.end());
1383 if (S->isAbstractScope())
1386 for (const InsnRange &R : S->getRanges()) {
1387 assert(R.first && "InsnRange does not have first instruction!");
1388 assert(R.second && "InsnRange does not have second instruction!");
1389 requestLabelBeforeInsn(R.first);
1390 requestLabelAfterInsn(R.second);
1395 // Gather pre-function debug information. Assumes being called immediately
1396 // after the function entry point has been emitted.
1397 void DwarfDebug::beginFunction(const MachineFunction *MF) {
1400 // If there's no debug info for the function we're not going to do anything.
1401 if (!MMI->hasDebugInfo())
1404 // Grab the lexical scopes for the function, if we don't have any of those
1405 // then we're not going to be able to do anything.
1406 LScopes.initialize(*MF);
1407 if (LScopes.empty())
1410 assert(DbgValues.empty() && "DbgValues map wasn't cleaned!");
1412 // Make sure that each lexical scope will have a begin/end label.
1413 identifyScopeMarkers();
1415 // Set DwarfDwarfCompileUnitID in MCContext to the Compile Unit this function
1416 // belongs to so that we add to the correct per-cu line table in the
1418 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1419 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1420 assert(TheCU && "Unable to find compile unit!");
1421 if (Asm->OutStreamer.hasRawTextSupport())
1422 // Use a single line table if we are generating assembly.
1423 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1425 Asm->OutStreamer.getContext().setDwarfCompileUnitID(TheCU->getUniqueID());
1427 // Emit a label for the function so that we have a beginning address.
1428 FunctionBeginSym = Asm->GetTempSymbol("func_begin", Asm->getFunctionNumber());
1429 // Assumes in correct section after the entry point.
1430 Asm->OutStreamer.EmitLabel(FunctionBeginSym);
1432 // Collect user variables, find the end of the prologue.
1433 for (const auto &MBB : *MF) {
1434 for (const auto &MI : MBB) {
1435 if (MI.isDebugValue()) {
1436 assert(MI.getNumOperands() > 1 && "Invalid machine instruction!");
1437 // Keep track of user variables in order of appearance. Create the
1438 // empty history for each variable so that the order of keys in
1439 // DbgValues is correct. Actual history will be populated in
1440 // calculateDbgValueHistory() function.
1441 const MDNode *Var = MI.getDebugVariable();
1443 std::make_pair(Var, SmallVector<const MachineInstr *, 4>()));
1444 } else if (!MI.getFlag(MachineInstr::FrameSetup) &&
1445 PrologEndLoc.isUnknown() && !MI.getDebugLoc().isUnknown()) {
1446 // First known non-DBG_VALUE and non-frame setup location marks
1447 // the beginning of the function body.
1448 PrologEndLoc = MI.getDebugLoc();
1453 // Calculate history for local variables.
1454 calculateDbgValueHistory(MF, Asm->TM.getRegisterInfo(), DbgValues);
1456 // Request labels for the full history.
1457 for (auto &I : DbgValues) {
1458 const SmallVectorImpl<const MachineInstr *> &History = I.second;
1459 if (History.empty())
1462 // The first mention of a function argument gets the FunctionBeginSym
1463 // label, so arguments are visible when breaking at function entry.
1464 DIVariable DV(I.first);
1465 if (DV.isVariable() && DV.getTag() == dwarf::DW_TAG_arg_variable &&
1466 getDISubprogram(DV.getContext()).describes(MF->getFunction()))
1467 LabelsBeforeInsn[History.front()] = FunctionBeginSym;
1469 for (const MachineInstr *MI : History) {
1470 if (MI->isDebugValue())
1471 requestLabelBeforeInsn(MI);
1473 requestLabelAfterInsn(MI);
1477 PrevInstLoc = DebugLoc();
1478 PrevLabel = FunctionBeginSym;
1480 // Record beginning of function.
1481 if (!PrologEndLoc.isUnknown()) {
1482 DebugLoc FnStartDL =
1483 PrologEndLoc.getFnDebugLoc(MF->getFunction()->getContext());
1485 FnStartDL.getLine(), FnStartDL.getCol(),
1486 FnStartDL.getScope(MF->getFunction()->getContext()),
1487 // We'd like to list the prologue as "not statements" but GDB behaves
1488 // poorly if we do that. Revisit this with caution/GDB (7.5+) testing.
1489 DWARF2_FLAG_IS_STMT);
1493 void DwarfDebug::addScopeVariable(LexicalScope *LS, DbgVariable *Var) {
1494 SmallVectorImpl<DbgVariable *> &Vars = ScopeVariables[LS];
1495 DIVariable DV = Var->getVariable();
1496 // Variables with positive arg numbers are parameters.
1497 if (unsigned ArgNum = DV.getArgNumber()) {
1498 // Keep all parameters in order at the start of the variable list to ensure
1499 // function types are correct (no out-of-order parameters)
1501 // This could be improved by only doing it for optimized builds (unoptimized
1502 // builds have the right order to begin with), searching from the back (this
1503 // would catch the unoptimized case quickly), or doing a binary search
1504 // rather than linear search.
1505 SmallVectorImpl<DbgVariable *>::iterator I = Vars.begin();
1506 while (I != Vars.end()) {
1507 unsigned CurNum = (*I)->getVariable().getArgNumber();
1508 // A local (non-parameter) variable has been found, insert immediately
1512 // A later indexed parameter has been found, insert immediately before it.
1513 if (CurNum > ArgNum)
1517 Vars.insert(I, Var);
1521 Vars.push_back(Var);
1524 // Gather and emit post-function debug information.
1525 void DwarfDebug::endFunction(const MachineFunction *MF) {
1526 // Every beginFunction(MF) call should be followed by an endFunction(MF) call,
1527 // though the beginFunction may not be called at all.
1528 // We should handle both cases.
1532 assert(CurFn == MF);
1533 assert(CurFn != nullptr);
1535 if (!MMI->hasDebugInfo() || LScopes.empty()) {
1536 // If we don't have a lexical scope for this function then there will
1537 // be a hole in the range information. Keep note of this by setting the
1538 // previously used section to nullptr.
1539 PrevSection = nullptr;
1545 // Define end label for subprogram.
1546 FunctionEndSym = Asm->GetTempSymbol("func_end", Asm->getFunctionNumber());
1547 // Assumes in correct section after the entry point.
1548 Asm->OutStreamer.EmitLabel(FunctionEndSym);
1550 // Set DwarfDwarfCompileUnitID in MCContext to default value.
1551 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1553 SmallPtrSet<const MDNode *, 16> ProcessedVars;
1554 collectVariableInfo(ProcessedVars);
1556 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1557 DwarfCompileUnit &TheCU = *SPMap.lookup(FnScope->getScopeNode());
1559 // Construct abstract scopes.
1560 for (LexicalScope *AScope : LScopes.getAbstractScopesList()) {
1561 DISubprogram SP(AScope->getScopeNode());
1562 if (!SP.isSubprogram())
1564 // Collect info for variables that were optimized out.
1565 DIArray Variables = SP.getVariables();
1566 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1567 DIVariable DV(Variables.getElement(i));
1568 assert(DV && DV.isVariable());
1569 if (!ProcessedVars.insert(DV))
1571 // Check that DbgVariable for DV wasn't created earlier, when
1572 // findAbstractVariable() was called for inlined instance of DV.
1573 LLVMContext &Ctx = DV->getContext();
1574 DIVariable CleanDV = cleanseInlinedVariable(DV, Ctx);
1575 if (AbstractVariables.lookup(CleanDV))
1577 if (LexicalScope *Scope = LScopes.findAbstractScope(DV.getContext()))
1578 addScopeVariable(Scope, new DbgVariable(DV, nullptr, this));
1580 constructAbstractSubprogramScopeDIE(TheCU, AScope);
1583 DIE &CurFnDIE = constructSubprogramScopeDIE(TheCU, FnScope);
1584 if (!CurFn->getTarget().Options.DisableFramePointerElim(*CurFn))
1585 TheCU.addFlag(CurFnDIE, dwarf::DW_AT_APPLE_omit_frame_ptr);
1587 // Add the range of this function to the list of ranges for the CU.
1588 RangeSpan Span(FunctionBeginSym, FunctionEndSym);
1589 TheCU.addRange(std::move(Span));
1590 PrevSection = Asm->getCurrentSection();
1594 for (auto &I : ScopeVariables)
1595 DeleteContainerPointers(I.second);
1596 ScopeVariables.clear();
1597 DeleteContainerPointers(CurrentFnArguments);
1599 AbstractVariables.clear();
1600 LabelsBeforeInsn.clear();
1601 LabelsAfterInsn.clear();
1602 PrevLabel = nullptr;
1606 // Register a source line with debug info. Returns the unique label that was
1607 // emitted and which provides correspondence to the source line list.
1608 void DwarfDebug::recordSourceLine(unsigned Line, unsigned Col, const MDNode *S,
1613 unsigned Discriminator = 0;
1614 if (DIScope Scope = DIScope(S)) {
1615 assert(Scope.isScope());
1616 Fn = Scope.getFilename();
1617 Dir = Scope.getDirectory();
1618 if (Scope.isLexicalBlock())
1619 Discriminator = DILexicalBlock(S).getDiscriminator();
1621 unsigned CUID = Asm->OutStreamer.getContext().getDwarfCompileUnitID();
1622 Src = static_cast<DwarfCompileUnit &>(*InfoHolder.getUnits()[CUID])
1623 .getOrCreateSourceID(Fn, Dir);
1625 Asm->OutStreamer.EmitDwarfLocDirective(Src, Line, Col, Flags, 0,
1629 //===----------------------------------------------------------------------===//
1631 //===----------------------------------------------------------------------===//
1633 // Emit initial Dwarf sections with a label at the start of each one.
1634 void DwarfDebug::emitSectionLabels() {
1635 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
1637 // Dwarf sections base addresses.
1638 DwarfInfoSectionSym =
1639 emitSectionSym(Asm, TLOF.getDwarfInfoSection(), "section_info");
1640 if (useSplitDwarf()) {
1641 DwarfInfoDWOSectionSym =
1642 emitSectionSym(Asm, TLOF.getDwarfInfoDWOSection(), "section_info_dwo");
1643 DwarfTypesDWOSectionSym =
1644 emitSectionSym(Asm, TLOF.getDwarfTypesDWOSection(), "section_types_dwo");
1646 DwarfAbbrevSectionSym =
1647 emitSectionSym(Asm, TLOF.getDwarfAbbrevSection(), "section_abbrev");
1648 if (useSplitDwarf())
1649 DwarfAbbrevDWOSectionSym = emitSectionSym(
1650 Asm, TLOF.getDwarfAbbrevDWOSection(), "section_abbrev_dwo");
1651 if (GenerateARangeSection)
1652 emitSectionSym(Asm, TLOF.getDwarfARangesSection());
1654 DwarfLineSectionSym =
1655 emitSectionSym(Asm, TLOF.getDwarfLineSection(), "section_line");
1656 if (GenerateGnuPubSections) {
1657 DwarfGnuPubNamesSectionSym =
1658 emitSectionSym(Asm, TLOF.getDwarfGnuPubNamesSection());
1659 DwarfGnuPubTypesSectionSym =
1660 emitSectionSym(Asm, TLOF.getDwarfGnuPubTypesSection());
1661 } else if (HasDwarfPubSections) {
1662 emitSectionSym(Asm, TLOF.getDwarfPubNamesSection());
1663 emitSectionSym(Asm, TLOF.getDwarfPubTypesSection());
1666 DwarfStrSectionSym =
1667 emitSectionSym(Asm, TLOF.getDwarfStrSection(), "info_string");
1668 if (useSplitDwarf()) {
1669 DwarfStrDWOSectionSym =
1670 emitSectionSym(Asm, TLOF.getDwarfStrDWOSection(), "skel_string");
1671 DwarfAddrSectionSym =
1672 emitSectionSym(Asm, TLOF.getDwarfAddrSection(), "addr_sec");
1673 DwarfDebugLocSectionSym =
1674 emitSectionSym(Asm, TLOF.getDwarfLocDWOSection(), "skel_loc");
1676 DwarfDebugLocSectionSym =
1677 emitSectionSym(Asm, TLOF.getDwarfLocSection(), "section_debug_loc");
1678 DwarfDebugRangeSectionSym =
1679 emitSectionSym(Asm, TLOF.getDwarfRangesSection(), "debug_range");
1682 // Recursively emits a debug information entry.
1683 void DwarfDebug::emitDIE(DIE &Die) {
1684 // Get the abbreviation for this DIE.
1685 const DIEAbbrev &Abbrev = Die.getAbbrev();
1687 // Emit the code (index) for the abbreviation.
1688 if (Asm->isVerbose())
1689 Asm->OutStreamer.AddComment("Abbrev [" + Twine(Abbrev.getNumber()) +
1690 "] 0x" + Twine::utohexstr(Die.getOffset()) +
1691 ":0x" + Twine::utohexstr(Die.getSize()) + " " +
1692 dwarf::TagString(Abbrev.getTag()));
1693 Asm->EmitULEB128(Abbrev.getNumber());
1695 const SmallVectorImpl<DIEValue *> &Values = Die.getValues();
1696 const SmallVectorImpl<DIEAbbrevData> &AbbrevData = Abbrev.getData();
1698 // Emit the DIE attribute values.
1699 for (unsigned i = 0, N = Values.size(); i < N; ++i) {
1700 dwarf::Attribute Attr = AbbrevData[i].getAttribute();
1701 dwarf::Form Form = AbbrevData[i].getForm();
1702 assert(Form && "Too many attributes for DIE (check abbreviation)");
1704 if (Asm->isVerbose()) {
1705 Asm->OutStreamer.AddComment(dwarf::AttributeString(Attr));
1706 if (Attr == dwarf::DW_AT_accessibility)
1707 Asm->OutStreamer.AddComment(dwarf::AccessibilityString(
1708 cast<DIEInteger>(Values[i])->getValue()));
1711 // Emit an attribute using the defined form.
1712 Values[i]->EmitValue(Asm, Form);
1715 // Emit the DIE children if any.
1716 if (Abbrev.hasChildren()) {
1717 for (auto &Child : Die.getChildren())
1720 Asm->OutStreamer.AddComment("End Of Children Mark");
1725 // Emit the debug info section.
1726 void DwarfDebug::emitDebugInfo() {
1727 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1729 Holder.emitUnits(this, DwarfAbbrevSectionSym);
1732 // Emit the abbreviation section.
1733 void DwarfDebug::emitAbbreviations() {
1734 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1736 Holder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevSection());
1739 // Emit the last address of the section and the end of the line matrix.
1740 void DwarfDebug::emitEndOfLineMatrix(unsigned SectionEnd) {
1741 // Define last address of section.
1742 Asm->OutStreamer.AddComment("Extended Op");
1745 Asm->OutStreamer.AddComment("Op size");
1746 Asm->EmitInt8(Asm->getDataLayout().getPointerSize() + 1);
1747 Asm->OutStreamer.AddComment("DW_LNE_set_address");
1748 Asm->EmitInt8(dwarf::DW_LNE_set_address);
1750 Asm->OutStreamer.AddComment("Section end label");
1752 Asm->OutStreamer.EmitSymbolValue(
1753 Asm->GetTempSymbol("section_end", SectionEnd),
1754 Asm->getDataLayout().getPointerSize());
1756 // Mark end of matrix.
1757 Asm->OutStreamer.AddComment("DW_LNE_end_sequence");
1763 // Emit visible names into a hashed accelerator table section.
1764 void DwarfDebug::emitAccelNames() {
1765 AccelNames.FinalizeTable(Asm, "Names");
1766 Asm->OutStreamer.SwitchSection(
1767 Asm->getObjFileLowering().getDwarfAccelNamesSection());
1768 MCSymbol *SectionBegin = Asm->GetTempSymbol("names_begin");
1769 Asm->OutStreamer.EmitLabel(SectionBegin);
1771 // Emit the full data.
1772 AccelNames.Emit(Asm, SectionBegin, &InfoHolder);
1775 // Emit objective C classes and categories into a hashed accelerator table
1777 void DwarfDebug::emitAccelObjC() {
1778 AccelObjC.FinalizeTable(Asm, "ObjC");
1779 Asm->OutStreamer.SwitchSection(
1780 Asm->getObjFileLowering().getDwarfAccelObjCSection());
1781 MCSymbol *SectionBegin = Asm->GetTempSymbol("objc_begin");
1782 Asm->OutStreamer.EmitLabel(SectionBegin);
1784 // Emit the full data.
1785 AccelObjC.Emit(Asm, SectionBegin, &InfoHolder);
1788 // Emit namespace dies into a hashed accelerator table.
1789 void DwarfDebug::emitAccelNamespaces() {
1790 AccelNamespace.FinalizeTable(Asm, "namespac");
1791 Asm->OutStreamer.SwitchSection(
1792 Asm->getObjFileLowering().getDwarfAccelNamespaceSection());
1793 MCSymbol *SectionBegin = Asm->GetTempSymbol("namespac_begin");
1794 Asm->OutStreamer.EmitLabel(SectionBegin);
1796 // Emit the full data.
1797 AccelNamespace.Emit(Asm, SectionBegin, &InfoHolder);
1800 // Emit type dies into a hashed accelerator table.
1801 void DwarfDebug::emitAccelTypes() {
1803 AccelTypes.FinalizeTable(Asm, "types");
1804 Asm->OutStreamer.SwitchSection(
1805 Asm->getObjFileLowering().getDwarfAccelTypesSection());
1806 MCSymbol *SectionBegin = Asm->GetTempSymbol("types_begin");
1807 Asm->OutStreamer.EmitLabel(SectionBegin);
1809 // Emit the full data.
1810 AccelTypes.Emit(Asm, SectionBegin, &InfoHolder);
1813 // Public name handling.
1814 // The format for the various pubnames:
1816 // dwarf pubnames - offset/name pairs where the offset is the offset into the CU
1817 // for the DIE that is named.
1819 // gnu pubnames - offset/index value/name tuples where the offset is the offset
1820 // into the CU and the index value is computed according to the type of value
1821 // for the DIE that is named.
1823 // For type units the offset is the offset of the skeleton DIE. For split dwarf
1824 // it's the offset within the debug_info/debug_types dwo section, however, the
1825 // reference in the pubname header doesn't change.
1827 /// computeIndexValue - Compute the gdb index value for the DIE and CU.
1828 static dwarf::PubIndexEntryDescriptor computeIndexValue(DwarfUnit *CU,
1830 dwarf::GDBIndexEntryLinkage Linkage = dwarf::GIEL_STATIC;
1832 // We could have a specification DIE that has our most of our knowledge,
1833 // look for that now.
1834 DIEValue *SpecVal = Die->findAttribute(dwarf::DW_AT_specification);
1836 DIE &SpecDIE = cast<DIEEntry>(SpecVal)->getEntry();
1837 if (SpecDIE.findAttribute(dwarf::DW_AT_external))
1838 Linkage = dwarf::GIEL_EXTERNAL;
1839 } else if (Die->findAttribute(dwarf::DW_AT_external))
1840 Linkage = dwarf::GIEL_EXTERNAL;
1842 switch (Die->getTag()) {
1843 case dwarf::DW_TAG_class_type:
1844 case dwarf::DW_TAG_structure_type:
1845 case dwarf::DW_TAG_union_type:
1846 case dwarf::DW_TAG_enumeration_type:
1847 return dwarf::PubIndexEntryDescriptor(
1848 dwarf::GIEK_TYPE, CU->getLanguage() != dwarf::DW_LANG_C_plus_plus
1849 ? dwarf::GIEL_STATIC
1850 : dwarf::GIEL_EXTERNAL);
1851 case dwarf::DW_TAG_typedef:
1852 case dwarf::DW_TAG_base_type:
1853 case dwarf::DW_TAG_subrange_type:
1854 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_TYPE, dwarf::GIEL_STATIC);
1855 case dwarf::DW_TAG_namespace:
1856 return dwarf::GIEK_TYPE;
1857 case dwarf::DW_TAG_subprogram:
1858 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_FUNCTION, Linkage);
1859 case dwarf::DW_TAG_constant:
1860 case dwarf::DW_TAG_variable:
1861 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE, Linkage);
1862 case dwarf::DW_TAG_enumerator:
1863 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE,
1864 dwarf::GIEL_STATIC);
1866 return dwarf::GIEK_NONE;
1870 /// emitDebugPubNames - Emit visible names into a debug pubnames section.
1872 void DwarfDebug::emitDebugPubNames(bool GnuStyle) {
1873 const MCSection *PSec =
1874 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubNamesSection()
1875 : Asm->getObjFileLowering().getDwarfPubNamesSection();
1877 emitDebugPubSection(GnuStyle, PSec, "Names", &DwarfUnit::getGlobalNames);
1880 void DwarfDebug::emitDebugPubSection(
1881 bool GnuStyle, const MCSection *PSec, StringRef Name,
1882 const StringMap<const DIE *> &(DwarfUnit::*Accessor)() const) {
1883 for (const auto &NU : CUMap) {
1884 DwarfCompileUnit *TheU = NU.second;
1886 const auto &Globals = (TheU->*Accessor)();
1888 if (Globals.empty())
1891 if (auto Skeleton = static_cast<DwarfCompileUnit *>(TheU->getSkeleton()))
1893 unsigned ID = TheU->getUniqueID();
1895 // Start the dwarf pubnames section.
1896 Asm->OutStreamer.SwitchSection(PSec);
1899 Asm->OutStreamer.AddComment("Length of Public " + Name + " Info");
1900 MCSymbol *BeginLabel = Asm->GetTempSymbol("pub" + Name + "_begin", ID);
1901 MCSymbol *EndLabel = Asm->GetTempSymbol("pub" + Name + "_end", ID);
1902 Asm->EmitLabelDifference(EndLabel, BeginLabel, 4);
1904 Asm->OutStreamer.EmitLabel(BeginLabel);
1906 Asm->OutStreamer.AddComment("DWARF Version");
1907 Asm->EmitInt16(dwarf::DW_PUBNAMES_VERSION);
1909 Asm->OutStreamer.AddComment("Offset of Compilation Unit Info");
1910 Asm->EmitSectionOffset(TheU->getLabelBegin(), TheU->getSectionSym());
1912 Asm->OutStreamer.AddComment("Compilation Unit Length");
1913 Asm->EmitLabelDifference(TheU->getLabelEnd(), TheU->getLabelBegin(), 4);
1915 // Emit the pubnames for this compilation unit.
1916 for (const auto &GI : Globals) {
1917 const char *Name = GI.getKeyData();
1918 const DIE *Entity = GI.second;
1920 Asm->OutStreamer.AddComment("DIE offset");
1921 Asm->EmitInt32(Entity->getOffset());
1924 dwarf::PubIndexEntryDescriptor Desc = computeIndexValue(TheU, Entity);
1925 Asm->OutStreamer.AddComment(
1926 Twine("Kind: ") + dwarf::GDBIndexEntryKindString(Desc.Kind) + ", " +
1927 dwarf::GDBIndexEntryLinkageString(Desc.Linkage));
1928 Asm->EmitInt8(Desc.toBits());
1931 Asm->OutStreamer.AddComment("External Name");
1932 Asm->OutStreamer.EmitBytes(StringRef(Name, GI.getKeyLength() + 1));
1935 Asm->OutStreamer.AddComment("End Mark");
1937 Asm->OutStreamer.EmitLabel(EndLabel);
1941 void DwarfDebug::emitDebugPubTypes(bool GnuStyle) {
1942 const MCSection *PSec =
1943 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubTypesSection()
1944 : Asm->getObjFileLowering().getDwarfPubTypesSection();
1946 emitDebugPubSection(GnuStyle, PSec, "Types", &DwarfUnit::getGlobalTypes);
1949 // Emit visible names into a debug str section.
1950 void DwarfDebug::emitDebugStr() {
1951 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1952 Holder.emitStrings(Asm->getObjFileLowering().getDwarfStrSection());
1955 void DwarfDebug::emitDebugLocEntry(ByteStreamer &Streamer,
1956 const DebugLocEntry &Entry) {
1957 assert(Entry.getValues().size() == 1 &&
1958 "multi-value entries are not supported yet.");
1959 const DebugLocEntry::Value Value = Entry.getValues()[0];
1960 DIVariable DV(Value.getVariable());
1961 if (Value.isInt()) {
1962 DIBasicType BTy(resolve(DV.getType()));
1963 if (BTy.Verify() && (BTy.getEncoding() == dwarf::DW_ATE_signed ||
1964 BTy.getEncoding() == dwarf::DW_ATE_signed_char)) {
1965 Streamer.EmitInt8(dwarf::DW_OP_consts, "DW_OP_consts");
1966 Streamer.EmitSLEB128(Value.getInt());
1968 Streamer.EmitInt8(dwarf::DW_OP_constu, "DW_OP_constu");
1969 Streamer.EmitULEB128(Value.getInt());
1971 } else if (Value.isLocation()) {
1972 MachineLocation Loc = Value.getLoc();
1973 if (!DV.hasComplexAddress())
1975 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
1977 // Complex address entry.
1978 unsigned N = DV.getNumAddrElements();
1980 if (N >= 2 && DV.getAddrElement(0) == DIBuilder::OpPlus) {
1981 if (Loc.getOffset()) {
1983 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
1984 Streamer.EmitInt8(dwarf::DW_OP_deref, "DW_OP_deref");
1985 Streamer.EmitInt8(dwarf::DW_OP_plus_uconst, "DW_OP_plus_uconst");
1986 Streamer.EmitSLEB128(DV.getAddrElement(1));
1988 // If first address element is OpPlus then emit
1989 // DW_OP_breg + Offset instead of DW_OP_reg + Offset.
1990 MachineLocation TLoc(Loc.getReg(), DV.getAddrElement(1));
1991 Asm->EmitDwarfRegOp(Streamer, TLoc, DV.isIndirect());
1995 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
1998 // Emit remaining complex address elements.
1999 for (; i < N; ++i) {
2000 uint64_t Element = DV.getAddrElement(i);
2001 if (Element == DIBuilder::OpPlus) {
2002 Streamer.EmitInt8(dwarf::DW_OP_plus_uconst, "DW_OP_plus_uconst");
2003 Streamer.EmitULEB128(DV.getAddrElement(++i));
2004 } else if (Element == DIBuilder::OpDeref) {
2006 Streamer.EmitInt8(dwarf::DW_OP_deref, "DW_OP_deref");
2008 llvm_unreachable("unknown Opcode found in complex address");
2012 // else ... ignore constant fp. There is not any good way to
2013 // to represent them here in dwarf.
2017 void DwarfDebug::emitDebugLocEntryLocation(const DebugLocEntry &Entry) {
2018 Asm->OutStreamer.AddComment("Loc expr size");
2019 MCSymbol *begin = Asm->OutStreamer.getContext().CreateTempSymbol();
2020 MCSymbol *end = Asm->OutStreamer.getContext().CreateTempSymbol();
2021 Asm->EmitLabelDifference(end, begin, 2);
2022 Asm->OutStreamer.EmitLabel(begin);
2024 APByteStreamer Streamer(*Asm);
2025 emitDebugLocEntry(Streamer, Entry);
2027 Asm->OutStreamer.EmitLabel(end);
2030 // Emit locations into the debug loc section.
2031 void DwarfDebug::emitDebugLoc() {
2032 // Start the dwarf loc section.
2033 Asm->OutStreamer.SwitchSection(
2034 Asm->getObjFileLowering().getDwarfLocSection());
2035 unsigned char Size = Asm->getDataLayout().getPointerSize();
2036 for (const auto &DebugLoc : DotDebugLocEntries) {
2037 Asm->OutStreamer.EmitLabel(DebugLoc.Label);
2038 for (const auto &Entry : DebugLoc.List) {
2039 // Set up the range. This range is relative to the entry point of the
2040 // compile unit. This is a hard coded 0 for low_pc when we're emitting
2041 // ranges, or the DW_AT_low_pc on the compile unit otherwise.
2042 const DwarfCompileUnit *CU = Entry.getCU();
2043 if (CU->getRanges().size() == 1) {
2044 // Grab the begin symbol from the first range as our base.
2045 const MCSymbol *Base = CU->getRanges()[0].getStart();
2046 Asm->EmitLabelDifference(Entry.getBeginSym(), Base, Size);
2047 Asm->EmitLabelDifference(Entry.getEndSym(), Base, Size);
2049 Asm->OutStreamer.EmitSymbolValue(Entry.getBeginSym(), Size);
2050 Asm->OutStreamer.EmitSymbolValue(Entry.getEndSym(), Size);
2053 emitDebugLocEntryLocation(Entry);
2055 Asm->OutStreamer.EmitIntValue(0, Size);
2056 Asm->OutStreamer.EmitIntValue(0, Size);
2060 void DwarfDebug::emitDebugLocDWO() {
2061 Asm->OutStreamer.SwitchSection(
2062 Asm->getObjFileLowering().getDwarfLocDWOSection());
2063 for (const auto &DebugLoc : DotDebugLocEntries) {
2064 Asm->OutStreamer.EmitLabel(DebugLoc.Label);
2065 for (const auto &Entry : DebugLoc.List) {
2066 // Just always use start_length for now - at least that's one address
2067 // rather than two. We could get fancier and try to, say, reuse an
2068 // address we know we've emitted elsewhere (the start of the function?
2069 // The start of the CU or CU subrange that encloses this range?)
2070 Asm->EmitInt8(dwarf::DW_LLE_start_length_entry);
2071 unsigned idx = AddrPool.getIndex(Entry.getBeginSym());
2072 Asm->EmitULEB128(idx);
2073 Asm->EmitLabelDifference(Entry.getEndSym(), Entry.getBeginSym(), 4);
2075 emitDebugLocEntryLocation(Entry);
2077 Asm->EmitInt8(dwarf::DW_LLE_end_of_list_entry);
2082 const MCSymbol *Start, *End;
2085 // Emit a debug aranges section, containing a CU lookup for any
2086 // address we can tie back to a CU.
2087 void DwarfDebug::emitDebugARanges() {
2088 // Start the dwarf aranges section.
2089 Asm->OutStreamer.SwitchSection(
2090 Asm->getObjFileLowering().getDwarfARangesSection());
2092 typedef DenseMap<DwarfCompileUnit *, std::vector<ArangeSpan>> SpansType;
2096 // Build a list of sections used.
2097 std::vector<const MCSection *> Sections;
2098 for (const auto &it : SectionMap) {
2099 const MCSection *Section = it.first;
2100 Sections.push_back(Section);
2103 // Sort the sections into order.
2104 // This is only done to ensure consistent output order across different runs.
2105 std::sort(Sections.begin(), Sections.end(), SectionSort);
2107 // Build a set of address spans, sorted by CU.
2108 for (const MCSection *Section : Sections) {
2109 SmallVector<SymbolCU, 8> &List = SectionMap[Section];
2110 if (List.size() < 2)
2113 // Sort the symbols by offset within the section.
2114 std::sort(List.begin(), List.end(),
2115 [&](const SymbolCU &A, const SymbolCU &B) {
2116 unsigned IA = A.Sym ? Asm->OutStreamer.GetSymbolOrder(A.Sym) : 0;
2117 unsigned IB = B.Sym ? Asm->OutStreamer.GetSymbolOrder(B.Sym) : 0;
2119 // Symbols with no order assigned should be placed at the end.
2120 // (e.g. section end labels)
2128 // If we have no section (e.g. common), just write out
2129 // individual spans for each symbol.
2131 for (const SymbolCU &Cur : List) {
2133 Span.Start = Cur.Sym;
2136 Spans[Cur.CU].push_back(Span);
2139 // Build spans between each label.
2140 const MCSymbol *StartSym = List[0].Sym;
2141 for (size_t n = 1, e = List.size(); n < e; n++) {
2142 const SymbolCU &Prev = List[n - 1];
2143 const SymbolCU &Cur = List[n];
2145 // Try and build the longest span we can within the same CU.
2146 if (Cur.CU != Prev.CU) {
2148 Span.Start = StartSym;
2150 Spans[Prev.CU].push_back(Span);
2157 unsigned PtrSize = Asm->getDataLayout().getPointerSize();
2159 // Build a list of CUs used.
2160 std::vector<DwarfCompileUnit *> CUs;
2161 for (const auto &it : Spans) {
2162 DwarfCompileUnit *CU = it.first;
2166 // Sort the CU list (again, to ensure consistent output order).
2167 std::sort(CUs.begin(), CUs.end(), [](const DwarfUnit *A, const DwarfUnit *B) {
2168 return A->getUniqueID() < B->getUniqueID();
2171 // Emit an arange table for each CU we used.
2172 for (DwarfCompileUnit *CU : CUs) {
2173 std::vector<ArangeSpan> &List = Spans[CU];
2175 // Emit size of content not including length itself.
2176 unsigned ContentSize =
2177 sizeof(int16_t) + // DWARF ARange version number
2178 sizeof(int32_t) + // Offset of CU in the .debug_info section
2179 sizeof(int8_t) + // Pointer Size (in bytes)
2180 sizeof(int8_t); // Segment Size (in bytes)
2182 unsigned TupleSize = PtrSize * 2;
2184 // 7.20 in the Dwarf specs requires the table to be aligned to a tuple.
2186 OffsetToAlignment(sizeof(int32_t) + ContentSize, TupleSize);
2188 ContentSize += Padding;
2189 ContentSize += (List.size() + 1) * TupleSize;
2191 // For each compile unit, write the list of spans it covers.
2192 Asm->OutStreamer.AddComment("Length of ARange Set");
2193 Asm->EmitInt32(ContentSize);
2194 Asm->OutStreamer.AddComment("DWARF Arange version number");
2195 Asm->EmitInt16(dwarf::DW_ARANGES_VERSION);
2196 Asm->OutStreamer.AddComment("Offset Into Debug Info Section");
2197 Asm->EmitSectionOffset(CU->getLocalLabelBegin(), CU->getLocalSectionSym());
2198 Asm->OutStreamer.AddComment("Address Size (in bytes)");
2199 Asm->EmitInt8(PtrSize);
2200 Asm->OutStreamer.AddComment("Segment Size (in bytes)");
2203 Asm->OutStreamer.EmitFill(Padding, 0xff);
2205 for (const ArangeSpan &Span : List) {
2206 Asm->EmitLabelReference(Span.Start, PtrSize);
2208 // Calculate the size as being from the span start to it's end.
2210 Asm->EmitLabelDifference(Span.End, Span.Start, PtrSize);
2212 // For symbols without an end marker (e.g. common), we
2213 // write a single arange entry containing just that one symbol.
2214 uint64_t Size = SymSize[Span.Start];
2218 Asm->OutStreamer.EmitIntValue(Size, PtrSize);
2222 Asm->OutStreamer.AddComment("ARange terminator");
2223 Asm->OutStreamer.EmitIntValue(0, PtrSize);
2224 Asm->OutStreamer.EmitIntValue(0, PtrSize);
2228 // Emit visible names into a debug ranges section.
2229 void DwarfDebug::emitDebugRanges() {
2230 // Start the dwarf ranges section.
2231 Asm->OutStreamer.SwitchSection(
2232 Asm->getObjFileLowering().getDwarfRangesSection());
2234 // Size for our labels.
2235 unsigned char Size = Asm->getDataLayout().getPointerSize();
2237 // Grab the specific ranges for the compile units in the module.
2238 for (const auto &I : CUMap) {
2239 DwarfCompileUnit *TheCU = I.second;
2241 // Iterate over the misc ranges for the compile units in the module.
2242 for (const RangeSpanList &List : TheCU->getRangeLists()) {
2243 // Emit our symbol so we can find the beginning of the range.
2244 Asm->OutStreamer.EmitLabel(List.getSym());
2246 for (const RangeSpan &Range : List.getRanges()) {
2247 const MCSymbol *Begin = Range.getStart();
2248 const MCSymbol *End = Range.getEnd();
2249 assert(Begin && "Range without a begin symbol?");
2250 assert(End && "Range without an end symbol?");
2251 if (TheCU->getRanges().size() == 1) {
2252 // Grab the begin symbol from the first range as our base.
2253 const MCSymbol *Base = TheCU->getRanges()[0].getStart();
2254 Asm->EmitLabelDifference(Begin, Base, Size);
2255 Asm->EmitLabelDifference(End, Base, Size);
2257 Asm->OutStreamer.EmitSymbolValue(Begin, Size);
2258 Asm->OutStreamer.EmitSymbolValue(End, Size);
2262 // And terminate the list with two 0 values.
2263 Asm->OutStreamer.EmitIntValue(0, Size);
2264 Asm->OutStreamer.EmitIntValue(0, Size);
2267 // Now emit a range for the CU itself.
2268 if (TheCU->getRanges().size() > 1) {
2269 Asm->OutStreamer.EmitLabel(
2270 Asm->GetTempSymbol("cu_ranges", TheCU->getUniqueID()));
2271 for (const RangeSpan &Range : TheCU->getRanges()) {
2272 const MCSymbol *Begin = Range.getStart();
2273 const MCSymbol *End = Range.getEnd();
2274 assert(Begin && "Range without a begin symbol?");
2275 assert(End && "Range without an end symbol?");
2276 Asm->OutStreamer.EmitSymbolValue(Begin, Size);
2277 Asm->OutStreamer.EmitSymbolValue(End, Size);
2279 // And terminate the list with two 0 values.
2280 Asm->OutStreamer.EmitIntValue(0, Size);
2281 Asm->OutStreamer.EmitIntValue(0, Size);
2286 // DWARF5 Experimental Separate Dwarf emitters.
2288 void DwarfDebug::initSkeletonUnit(const DwarfUnit &U, DIE &Die,
2289 std::unique_ptr<DwarfUnit> NewU) {
2290 NewU->addLocalString(Die, dwarf::DW_AT_GNU_dwo_name,
2291 U.getCUNode().getSplitDebugFilename());
2293 if (!CompilationDir.empty())
2294 NewU->addLocalString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
2296 addGnuPubAttributes(*NewU, Die);
2298 SkeletonHolder.addUnit(std::move(NewU));
2301 // This DIE has the following attributes: DW_AT_comp_dir, DW_AT_stmt_list,
2302 // DW_AT_low_pc, DW_AT_high_pc, DW_AT_ranges, DW_AT_dwo_name, DW_AT_dwo_id,
2303 // DW_AT_addr_base, DW_AT_ranges_base.
2304 DwarfCompileUnit &DwarfDebug::constructSkeletonCU(const DwarfCompileUnit &CU) {
2306 auto OwnedUnit = make_unique<DwarfCompileUnit>(
2307 CU.getUniqueID(), CU.getCUNode(), Asm, this, &SkeletonHolder);
2308 DwarfCompileUnit &NewCU = *OwnedUnit;
2309 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoSection(),
2310 DwarfInfoSectionSym);
2312 NewCU.initStmtList(DwarfLineSectionSym);
2314 initSkeletonUnit(CU, NewCU.getUnitDie(), std::move(OwnedUnit));
2319 // This DIE has the following attributes: DW_AT_comp_dir, DW_AT_dwo_name,
2321 DwarfTypeUnit &DwarfDebug::constructSkeletonTU(DwarfTypeUnit &TU) {
2322 DwarfCompileUnit &CU = static_cast<DwarfCompileUnit &>(
2323 *SkeletonHolder.getUnits()[TU.getCU().getUniqueID()]);
2325 auto OwnedUnit = make_unique<DwarfTypeUnit>(TU.getUniqueID(), CU, Asm, this,
2327 DwarfTypeUnit &NewTU = *OwnedUnit;
2328 NewTU.setTypeSignature(TU.getTypeSignature());
2329 NewTU.setType(nullptr);
2331 Asm->getObjFileLowering().getDwarfTypesSection(TU.getTypeSignature()));
2333 initSkeletonUnit(TU, NewTU.getUnitDie(), std::move(OwnedUnit));
2337 // Emit the .debug_info.dwo section for separated dwarf. This contains the
2338 // compile units that would normally be in debug_info.
2339 void DwarfDebug::emitDebugInfoDWO() {
2340 assert(useSplitDwarf() && "No split dwarf debug info?");
2341 // Don't pass an abbrev symbol, using a constant zero instead so as not to
2342 // emit relocations into the dwo file.
2343 InfoHolder.emitUnits(this, /* AbbrevSymbol */ nullptr);
2346 // Emit the .debug_abbrev.dwo section for separated dwarf. This contains the
2347 // abbreviations for the .debug_info.dwo section.
2348 void DwarfDebug::emitDebugAbbrevDWO() {
2349 assert(useSplitDwarf() && "No split dwarf?");
2350 InfoHolder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevDWOSection());
2353 void DwarfDebug::emitDebugLineDWO() {
2354 assert(useSplitDwarf() && "No split dwarf?");
2355 Asm->OutStreamer.SwitchSection(
2356 Asm->getObjFileLowering().getDwarfLineDWOSection());
2357 SplitTypeUnitFileTable.Emit(Asm->OutStreamer);
2360 // Emit the .debug_str.dwo section for separated dwarf. This contains the
2361 // string section and is identical in format to traditional .debug_str
2363 void DwarfDebug::emitDebugStrDWO() {
2364 assert(useSplitDwarf() && "No split dwarf?");
2365 const MCSection *OffSec =
2366 Asm->getObjFileLowering().getDwarfStrOffDWOSection();
2367 const MCSymbol *StrSym = DwarfStrSectionSym;
2368 InfoHolder.emitStrings(Asm->getObjFileLowering().getDwarfStrDWOSection(),
2372 MCDwarfDwoLineTable *DwarfDebug::getDwoLineTable(const DwarfCompileUnit &CU) {
2373 if (!useSplitDwarf())
2376 SplitTypeUnitFileTable.setCompilationDir(CU.getCUNode().getDirectory());
2377 return &SplitTypeUnitFileTable;
2380 static uint64_t makeTypeSignature(StringRef Identifier) {
2382 Hash.update(Identifier);
2383 // ... take the least significant 8 bytes and return those. Our MD5
2384 // implementation always returns its results in little endian, swap bytes
2386 MD5::MD5Result Result;
2388 return *reinterpret_cast<support::ulittle64_t *>(Result + 8);
2391 void DwarfDebug::addDwarfTypeUnitType(DwarfCompileUnit &CU,
2392 StringRef Identifier, DIE &RefDie,
2393 DICompositeType CTy) {
2394 // Fast path if we're building some type units and one has already used the
2395 // address pool we know we're going to throw away all this work anyway, so
2396 // don't bother building dependent types.
2397 if (!TypeUnitsUnderConstruction.empty() && AddrPool.hasBeenUsed())
2400 const DwarfTypeUnit *&TU = DwarfTypeUnits[CTy];
2402 CU.addDIETypeSignature(RefDie, *TU);
2406 bool TopLevelType = TypeUnitsUnderConstruction.empty();
2407 AddrPool.resetUsedFlag();
2409 auto OwnedUnit = make_unique<DwarfTypeUnit>(
2410 InfoHolder.getUnits().size() + TypeUnitsUnderConstruction.size(), CU, Asm,
2411 this, &InfoHolder, getDwoLineTable(CU));
2412 DwarfTypeUnit &NewTU = *OwnedUnit;
2413 DIE &UnitDie = NewTU.getUnitDie();
2415 TypeUnitsUnderConstruction.push_back(
2416 std::make_pair(std::move(OwnedUnit), CTy));
2418 NewTU.addUInt(UnitDie, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
2421 uint64_t Signature = makeTypeSignature(Identifier);
2422 NewTU.setTypeSignature(Signature);
2424 if (useSplitDwarf())
2425 NewTU.initSection(Asm->getObjFileLowering().getDwarfTypesDWOSection(),
2426 DwarfTypesDWOSectionSym);
2428 CU.applyStmtList(UnitDie);
2430 Asm->getObjFileLowering().getDwarfTypesSection(Signature));
2433 NewTU.setType(NewTU.createTypeDIE(CTy));
2436 auto TypeUnitsToAdd = std::move(TypeUnitsUnderConstruction);
2437 TypeUnitsUnderConstruction.clear();
2439 // Types referencing entries in the address table cannot be placed in type
2441 if (AddrPool.hasBeenUsed()) {
2443 // Remove all the types built while building this type.
2444 // This is pessimistic as some of these types might not be dependent on
2445 // the type that used an address.
2446 for (const auto &TU : TypeUnitsToAdd)
2447 DwarfTypeUnits.erase(TU.second);
2449 // Construct this type in the CU directly.
2450 // This is inefficient because all the dependent types will be rebuilt
2451 // from scratch, including building them in type units, discovering that
2452 // they depend on addresses, throwing them out and rebuilding them.
2453 CU.constructTypeDIE(RefDie, CTy);
2457 // If the type wasn't dependent on fission addresses, finish adding the type
2458 // and all its dependent types.
2459 for (auto &TU : TypeUnitsToAdd) {
2460 if (useSplitDwarf())
2461 TU.first->setSkeleton(constructSkeletonTU(*TU.first));
2462 InfoHolder.addUnit(std::move(TU.first));
2465 CU.addDIETypeSignature(RefDie, NewTU);
2468 void DwarfDebug::attachLowHighPC(DwarfCompileUnit &Unit, DIE &D,
2469 MCSymbol *Begin, MCSymbol *End) {
2470 Unit.addLabelAddress(D, dwarf::DW_AT_low_pc, Begin);
2471 if (DwarfVersion < 4)
2472 Unit.addLabelAddress(D, dwarf::DW_AT_high_pc, End);
2474 Unit.addLabelDelta(D, dwarf::DW_AT_high_pc, End, Begin);
2477 // Accelerator table mutators - add each name along with its companion
2478 // DIE to the proper table while ensuring that the name that we're going
2479 // to reference is in the string table. We do this since the names we
2480 // add may not only be identical to the names in the DIE.
2481 void DwarfDebug::addAccelName(StringRef Name, const DIE &Die) {
2482 if (!useDwarfAccelTables())
2484 AccelNames.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2488 void DwarfDebug::addAccelObjC(StringRef Name, const DIE &Die) {
2489 if (!useDwarfAccelTables())
2491 AccelObjC.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2495 void DwarfDebug::addAccelNamespace(StringRef Name, const DIE &Die) {
2496 if (!useDwarfAccelTables())
2498 AccelNamespace.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2502 void DwarfDebug::addAccelType(StringRef Name, const DIE &Die, char Flags) {
2503 if (!useDwarfAccelTables())
2505 AccelTypes.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),