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 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 ProcessedSPNodes.insert(Sub);
581 if (DIE *ScopeDIE = TheCU.getDIE(Sub)) {
582 AbstractSPDies.insert(std::make_pair(Sub, ScopeDIE));
583 createAndAddScopeChildren(TheCU, Scope, *ScopeDIE);
587 DIE &DwarfDebug::constructSubprogramScopeDIE(DwarfCompileUnit &TheCU,
588 LexicalScope *Scope) {
589 assert(Scope && Scope->getScopeNode());
590 assert(!Scope->getInlinedAt());
591 assert(!Scope->isAbstractScope());
592 assert(DIScope(Scope->getScopeNode()).isSubprogram());
594 DISubprogram Sub(Scope->getScopeNode());
596 ProcessedSPNodes.insert(Sub);
598 DIE &ScopeDIE = updateSubprogramScopeDIE(TheCU, Sub);
600 createAndAddScopeChildren(TheCU, Scope, ScopeDIE);
605 // Construct a DIE for this scope.
606 std::unique_ptr<DIE> DwarfDebug::constructScopeDIE(DwarfCompileUnit &TheCU,
607 LexicalScope *Scope) {
608 if (!Scope || !Scope->getScopeNode())
611 DIScope DS(Scope->getScopeNode());
613 assert((Scope->getInlinedAt() || !DS.isSubprogram()) &&
614 "Only handle inlined subprograms here, use "
615 "constructSubprogramScopeDIE for non-inlined "
618 SmallVector<std::unique_ptr<DIE>, 8> Children;
620 // We try to create the scope DIE first, then the children DIEs. This will
621 // avoid creating un-used children then removing them later when we find out
622 // the scope DIE is null.
623 std::unique_ptr<DIE> ScopeDIE;
624 if (Scope->getInlinedAt()) {
625 ScopeDIE = constructInlinedScopeDIE(TheCU, Scope);
628 // We create children when the scope DIE is not null.
629 createScopeChildrenDIE(TheCU, Scope, Children);
631 // Early exit when we know the scope DIE is going to be null.
632 if (isLexicalScopeDIENull(Scope))
635 // We create children here when we know the scope DIE is not going to be
636 // null and the children will be added to the scope DIE.
637 createScopeChildrenDIE(TheCU, Scope, Children);
639 // There is no need to emit empty lexical block DIE.
640 std::pair<ImportedEntityMap::const_iterator,
641 ImportedEntityMap::const_iterator> Range =
642 std::equal_range(ScopesWithImportedEntities.begin(),
643 ScopesWithImportedEntities.end(),
644 std::pair<const MDNode *, const MDNode *>(DS, nullptr),
646 if (Children.empty() && Range.first == Range.second)
648 ScopeDIE = constructLexicalScopeDIE(TheCU, Scope);
649 assert(ScopeDIE && "Scope DIE should not be null.");
650 for (ImportedEntityMap::const_iterator i = Range.first; i != Range.second;
652 constructImportedEntityDIE(TheCU, i->second, *ScopeDIE);
656 for (auto &I : Children)
657 ScopeDIE->addChild(std::move(I));
662 void DwarfDebug::addGnuPubAttributes(DwarfUnit &U, DIE &D) const {
663 if (!GenerateGnuPubSections)
666 U.addFlag(D, dwarf::DW_AT_GNU_pubnames);
669 // Create new DwarfCompileUnit for the given metadata node with tag
670 // DW_TAG_compile_unit.
671 DwarfCompileUnit &DwarfDebug::constructDwarfCompileUnit(DICompileUnit DIUnit) {
672 StringRef FN = DIUnit.getFilename();
673 CompilationDir = DIUnit.getDirectory();
675 auto OwnedUnit = make_unique<DwarfCompileUnit>(
676 InfoHolder.getUnits().size(), DIUnit, Asm, this, &InfoHolder);
677 DwarfCompileUnit &NewCU = *OwnedUnit;
678 DIE &Die = NewCU.getUnitDie();
679 InfoHolder.addUnit(std::move(OwnedUnit));
681 // LTO with assembly output shares a single line table amongst multiple CUs.
682 // To avoid the compilation directory being ambiguous, let the line table
683 // explicitly describe the directory of all files, never relying on the
684 // compilation directory.
685 if (!Asm->OutStreamer.hasRawTextSupport() || SingleCU)
686 Asm->OutStreamer.getContext().setMCLineTableCompilationDir(
687 NewCU.getUniqueID(), CompilationDir);
689 NewCU.addString(Die, dwarf::DW_AT_producer, DIUnit.getProducer());
690 NewCU.addUInt(Die, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
691 DIUnit.getLanguage());
692 NewCU.addString(Die, dwarf::DW_AT_name, FN);
694 if (!useSplitDwarf()) {
695 NewCU.initStmtList(DwarfLineSectionSym);
697 // If we're using split dwarf the compilation dir is going to be in the
698 // skeleton CU and so we don't need to duplicate it here.
699 if (!CompilationDir.empty())
700 NewCU.addString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
702 addGnuPubAttributes(NewCU, Die);
705 if (DIUnit.isOptimized())
706 NewCU.addFlag(Die, dwarf::DW_AT_APPLE_optimized);
708 StringRef Flags = DIUnit.getFlags();
710 NewCU.addString(Die, dwarf::DW_AT_APPLE_flags, Flags);
712 if (unsigned RVer = DIUnit.getRunTimeVersion())
713 NewCU.addUInt(Die, dwarf::DW_AT_APPLE_major_runtime_vers,
714 dwarf::DW_FORM_data1, RVer);
719 if (useSplitDwarf()) {
720 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoDWOSection(),
721 DwarfInfoDWOSectionSym);
722 NewCU.setSkeleton(constructSkeletonCU(NewCU));
724 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoSection(),
725 DwarfInfoSectionSym);
727 CUMap.insert(std::make_pair(DIUnit, &NewCU));
728 CUDieMap.insert(std::make_pair(&Die, &NewCU));
732 // Construct subprogram DIE.
733 void DwarfDebug::constructSubprogramDIE(DwarfCompileUnit &TheCU,
735 // FIXME: We should only call this routine once, however, during LTO if a
736 // program is defined in multiple CUs we could end up calling it out of
737 // beginModule as we walk the CUs.
739 DwarfCompileUnit *&CURef = SPMap[N];
745 if (!SP.isDefinition())
746 // This is a method declaration which will be handled while constructing
750 DIE &SubprogramDie = *TheCU.getOrCreateSubprogramDIE(SP);
752 // Expose as a global name.
753 TheCU.addGlobalName(SP.getName(), SubprogramDie, resolve(SP.getContext()));
756 void DwarfDebug::constructImportedEntityDIE(DwarfCompileUnit &TheCU,
758 DIImportedEntity Module(N);
759 assert(Module.Verify());
760 if (DIE *D = TheCU.getOrCreateContextDIE(Module.getContext()))
761 constructImportedEntityDIE(TheCU, Module, *D);
764 void DwarfDebug::constructImportedEntityDIE(DwarfCompileUnit &TheCU,
765 const MDNode *N, DIE &Context) {
766 DIImportedEntity Module(N);
767 assert(Module.Verify());
768 return constructImportedEntityDIE(TheCU, Module, Context);
771 void DwarfDebug::constructImportedEntityDIE(DwarfCompileUnit &TheCU,
772 const DIImportedEntity &Module,
774 assert(Module.Verify() &&
775 "Use one of the MDNode * overloads to handle invalid metadata");
776 DIE &IMDie = TheCU.createAndAddDIE(Module.getTag(), Context, Module);
778 DIDescriptor Entity = resolve(Module.getEntity());
779 if (Entity.isNameSpace())
780 EntityDie = TheCU.getOrCreateNameSpace(DINameSpace(Entity));
781 else if (Entity.isSubprogram())
782 EntityDie = TheCU.getOrCreateSubprogramDIE(DISubprogram(Entity));
783 else if (Entity.isType())
784 EntityDie = TheCU.getOrCreateTypeDIE(DIType(Entity));
786 EntityDie = TheCU.getDIE(Entity);
787 TheCU.addSourceLine(IMDie, Module.getLineNumber(),
788 Module.getContext().getFilename(),
789 Module.getContext().getDirectory());
790 TheCU.addDIEEntry(IMDie, dwarf::DW_AT_import, *EntityDie);
791 StringRef Name = Module.getName();
793 TheCU.addString(IMDie, dwarf::DW_AT_name, Name);
796 // Emit all Dwarf sections that should come prior to the content. Create
797 // global DIEs and emit initial debug info sections. This is invoked by
798 // the target AsmPrinter.
799 void DwarfDebug::beginModule() {
800 if (DisableDebugInfoPrinting)
803 const Module *M = MMI->getModule();
805 // If module has named metadata anchors then use them, otherwise scan the
806 // module using debug info finder to collect debug info.
807 NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
810 TypeIdentifierMap = generateDITypeIdentifierMap(CU_Nodes);
812 // Emit initial sections so we can reference labels later.
815 SingleCU = CU_Nodes->getNumOperands() == 1;
817 for (MDNode *N : CU_Nodes->operands()) {
818 DICompileUnit CUNode(N);
819 DwarfCompileUnit &CU = constructDwarfCompileUnit(CUNode);
820 DIArray ImportedEntities = CUNode.getImportedEntities();
821 for (unsigned i = 0, e = ImportedEntities.getNumElements(); i != e; ++i)
822 ScopesWithImportedEntities.push_back(std::make_pair(
823 DIImportedEntity(ImportedEntities.getElement(i)).getContext(),
824 ImportedEntities.getElement(i)));
825 std::sort(ScopesWithImportedEntities.begin(),
826 ScopesWithImportedEntities.end(), less_first());
827 DIArray GVs = CUNode.getGlobalVariables();
828 for (unsigned i = 0, e = GVs.getNumElements(); i != e; ++i)
829 CU.createGlobalVariableDIE(DIGlobalVariable(GVs.getElement(i)));
830 DIArray SPs = CUNode.getSubprograms();
831 for (unsigned i = 0, e = SPs.getNumElements(); i != e; ++i)
832 constructSubprogramDIE(CU, SPs.getElement(i));
833 DIArray EnumTypes = CUNode.getEnumTypes();
834 for (unsigned i = 0, e = EnumTypes.getNumElements(); i != e; ++i)
835 CU.getOrCreateTypeDIE(EnumTypes.getElement(i));
836 DIArray RetainedTypes = CUNode.getRetainedTypes();
837 for (unsigned i = 0, e = RetainedTypes.getNumElements(); i != e; ++i) {
838 DIType Ty(RetainedTypes.getElement(i));
839 // The retained types array by design contains pointers to
840 // MDNodes rather than DIRefs. Unique them here.
841 DIType UniqueTy(resolve(Ty.getRef()));
842 CU.getOrCreateTypeDIE(UniqueTy);
844 // Emit imported_modules last so that the relevant context is already
846 for (unsigned i = 0, e = ImportedEntities.getNumElements(); i != e; ++i)
847 constructImportedEntityDIE(CU, ImportedEntities.getElement(i));
850 // Tell MMI that we have debug info.
851 MMI->setDebugInfoAvailability(true);
853 // Prime section data.
854 SectionMap[Asm->getObjFileLowering().getTextSection()];
857 // Attach DW_AT_inline attribute with inlined subprogram DIEs.
858 void DwarfDebug::computeInlinedDIEs() {
859 // Attach DW_AT_inline attribute with inlined subprogram DIEs.
860 for (DIE *ISP : InlinedSubprogramDIEs)
861 FirstCU->addUInt(*ISP, dwarf::DW_AT_inline, None, dwarf::DW_INL_inlined);
863 for (const auto &AI : AbstractSPDies) {
864 DIE &ISP = *AI.second;
865 if (InlinedSubprogramDIEs.count(&ISP))
867 FirstCU->addUInt(ISP, dwarf::DW_AT_inline, None, dwarf::DW_INL_inlined);
871 // Collect info for variables that were optimized out.
872 void DwarfDebug::collectDeadVariables() {
873 const Module *M = MMI->getModule();
875 if (NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu")) {
876 for (MDNode *N : CU_Nodes->operands()) {
877 DICompileUnit TheCU(N);
878 DIArray Subprograms = TheCU.getSubprograms();
879 for (unsigned i = 0, e = Subprograms.getNumElements(); i != e; ++i) {
880 DISubprogram SP(Subprograms.getElement(i));
881 if (ProcessedSPNodes.count(SP) != 0)
883 if (!SP.isSubprogram())
885 if (!SP.isDefinition())
887 DIArray Variables = SP.getVariables();
888 if (Variables.getNumElements() == 0)
891 // Construct subprogram DIE and add variables DIEs.
892 DwarfCompileUnit *SPCU =
893 static_cast<DwarfCompileUnit *>(CUMap.lookup(TheCU));
894 assert(SPCU && "Unable to find Compile Unit!");
895 // FIXME: See the comment in constructSubprogramDIE about duplicate
897 constructSubprogramDIE(*SPCU, SP);
898 DIE *SPDIE = SPCU->getDIE(SP);
899 for (unsigned vi = 0, ve = Variables.getNumElements(); vi != ve; ++vi) {
900 DIVariable DV(Variables.getElement(vi));
901 if (!DV.isVariable())
903 DbgVariable NewVar(DV, nullptr, this);
904 SPDIE->addChild(SPCU->constructVariableDIE(NewVar));
911 void DwarfDebug::finalizeModuleInfo() {
912 // Collect info for variables that were optimized out.
913 collectDeadVariables();
915 // Attach DW_AT_inline attribute with inlined subprogram DIEs.
916 computeInlinedDIEs();
918 // Handle anything that needs to be done on a per-unit basis after
919 // all other generation.
920 for (const auto &TheU : getUnits()) {
921 // Emit DW_AT_containing_type attribute to connect types with their
922 // vtable holding type.
923 TheU->constructContainingTypeDIEs();
925 // Add CU specific attributes if we need to add any.
926 if (TheU->getUnitDie().getTag() == dwarf::DW_TAG_compile_unit) {
927 // If we're splitting the dwarf out now that we've got the entire
928 // CU then add the dwo id to it.
929 DwarfCompileUnit *SkCU =
930 static_cast<DwarfCompileUnit *>(TheU->getSkeleton());
931 if (useSplitDwarf()) {
932 // Emit a unique identifier for this CU.
933 uint64_t ID = DIEHash(Asm).computeCUSignature(TheU->getUnitDie());
934 TheU->addUInt(TheU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
935 dwarf::DW_FORM_data8, ID);
936 SkCU->addUInt(SkCU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
937 dwarf::DW_FORM_data8, ID);
939 // We don't keep track of which addresses are used in which CU so this
940 // is a bit pessimistic under LTO.
941 if (!AddrPool.isEmpty())
942 addSectionLabel(*Asm, *SkCU, SkCU->getUnitDie(),
943 dwarf::DW_AT_GNU_addr_base, DwarfAddrSectionSym,
944 DwarfAddrSectionSym);
945 if (!TheU->getRangeLists().empty())
946 addSectionLabel(*Asm, *SkCU, SkCU->getUnitDie(),
947 dwarf::DW_AT_GNU_ranges_base,
948 DwarfDebugRangeSectionSym, DwarfDebugRangeSectionSym);
951 // If we have code split among multiple sections or non-contiguous
952 // ranges of code then emit a DW_AT_ranges attribute on the unit that will
953 // remain in the .o file, otherwise add a DW_AT_low_pc.
954 // FIXME: We should use ranges allow reordering of code ala
955 // .subsections_via_symbols in mach-o. This would mean turning on
956 // ranges for all subprogram DIEs for mach-o.
957 DwarfCompileUnit &U =
958 SkCU ? *SkCU : static_cast<DwarfCompileUnit &>(*TheU);
959 unsigned NumRanges = TheU->getRanges().size();
962 addSectionLabel(*Asm, U, U.getUnitDie(), dwarf::DW_AT_ranges,
963 Asm->GetTempSymbol("cu_ranges", U.getUniqueID()),
964 DwarfDebugRangeSectionSym);
966 // A DW_AT_low_pc attribute may also be specified in combination with
967 // DW_AT_ranges to specify the default base address for use in
968 // location lists (see Section 2.6.2) and range lists (see Section
970 U.addUInt(U.getUnitDie(), dwarf::DW_AT_low_pc, dwarf::DW_FORM_addr,
973 RangeSpan &Range = TheU->getRanges().back();
974 U.addLocalLabelAddress(U.getUnitDie(), dwarf::DW_AT_low_pc,
976 U.addLabelDelta(U.getUnitDie(), dwarf::DW_AT_high_pc, Range.getEnd(),
983 // Compute DIE offsets and sizes.
984 InfoHolder.computeSizeAndOffsets();
986 SkeletonHolder.computeSizeAndOffsets();
989 void DwarfDebug::endSections() {
990 // Filter labels by section.
991 for (const SymbolCU &SCU : ArangeLabels) {
992 if (SCU.Sym->isInSection()) {
993 // Make a note of this symbol and it's section.
994 const MCSection *Section = &SCU.Sym->getSection();
995 if (!Section->getKind().isMetadata())
996 SectionMap[Section].push_back(SCU);
998 // Some symbols (e.g. common/bss on mach-o) can have no section but still
999 // appear in the output. This sucks as we rely on sections to build
1000 // arange spans. We can do it without, but it's icky.
1001 SectionMap[nullptr].push_back(SCU);
1005 // Build a list of sections used.
1006 std::vector<const MCSection *> Sections;
1007 for (const auto &it : SectionMap) {
1008 const MCSection *Section = it.first;
1009 Sections.push_back(Section);
1012 // Sort the sections into order.
1013 // This is only done to ensure consistent output order across different runs.
1014 std::sort(Sections.begin(), Sections.end(), SectionSort);
1016 // Add terminating symbols for each section.
1017 for (unsigned ID = 0, E = Sections.size(); ID != E; ID++) {
1018 const MCSection *Section = Sections[ID];
1019 MCSymbol *Sym = nullptr;
1022 // We can't call MCSection::getLabelEndName, as it's only safe to do so
1023 // if we know the section name up-front. For user-created sections, the
1024 // resulting label may not be valid to use as a label. (section names can
1025 // use a greater set of characters on some systems)
1026 Sym = Asm->GetTempSymbol("debug_end", ID);
1027 Asm->OutStreamer.SwitchSection(Section);
1028 Asm->OutStreamer.EmitLabel(Sym);
1031 // Insert a final terminator.
1032 SectionMap[Section].push_back(SymbolCU(nullptr, Sym));
1036 // Emit all Dwarf sections that should come after the content.
1037 void DwarfDebug::endModule() {
1038 assert(CurFn == nullptr);
1039 assert(CurMI == nullptr);
1044 // End any existing sections.
1045 // TODO: Does this need to happen?
1048 // Finalize the debug info for the module.
1049 finalizeModuleInfo();
1053 // Emit all the DIEs into a debug info section.
1056 // Corresponding abbreviations into a abbrev section.
1057 emitAbbreviations();
1059 // Emit info into a debug aranges section.
1060 if (GenerateARangeSection)
1063 // Emit info into a debug ranges section.
1066 if (useSplitDwarf()) {
1069 emitDebugAbbrevDWO();
1071 // Emit DWO addresses.
1072 AddrPool.emit(*Asm, Asm->getObjFileLowering().getDwarfAddrSection());
1075 // Emit info into a debug loc section.
1078 // Emit info into the dwarf accelerator table sections.
1079 if (useDwarfAccelTables()) {
1082 emitAccelNamespaces();
1086 // Emit the pubnames and pubtypes sections if requested.
1087 if (HasDwarfPubSections) {
1088 emitDebugPubNames(GenerateGnuPubSections);
1089 emitDebugPubTypes(GenerateGnuPubSections);
1095 // Reset these for the next Module if we have one.
1099 // Find abstract variable, if any, associated with Var.
1100 DbgVariable *DwarfDebug::findAbstractVariable(DIVariable &DV,
1101 DebugLoc ScopeLoc) {
1102 LLVMContext &Ctx = DV->getContext();
1103 // More then one inlined variable corresponds to one abstract variable.
1104 DIVariable Var = cleanseInlinedVariable(DV, Ctx);
1105 DbgVariable *AbsDbgVariable = AbstractVariables.lookup(Var);
1107 return AbsDbgVariable;
1109 LexicalScope *Scope = LScopes.findAbstractScope(ScopeLoc.getScope(Ctx));
1113 AbsDbgVariable = new DbgVariable(Var, nullptr, this);
1114 addScopeVariable(Scope, AbsDbgVariable);
1115 AbstractVariables[Var] = AbsDbgVariable;
1116 return AbsDbgVariable;
1119 // If Var is a current function argument then add it to CurrentFnArguments list.
1120 bool DwarfDebug::addCurrentFnArgument(DbgVariable *Var, LexicalScope *Scope) {
1121 if (!LScopes.isCurrentFunctionScope(Scope))
1123 DIVariable DV = Var->getVariable();
1124 if (DV.getTag() != dwarf::DW_TAG_arg_variable)
1126 unsigned ArgNo = DV.getArgNumber();
1130 size_t Size = CurrentFnArguments.size();
1132 CurrentFnArguments.resize(CurFn->getFunction()->arg_size());
1133 // llvm::Function argument size is not good indicator of how many
1134 // arguments does the function have at source level.
1136 CurrentFnArguments.resize(ArgNo * 2);
1137 CurrentFnArguments[ArgNo - 1] = Var;
1141 // Collect variable information from side table maintained by MMI.
1142 void DwarfDebug::collectVariableInfoFromMMITable(
1143 SmallPtrSet<const MDNode *, 16> &Processed) {
1144 for (const auto &VI : MMI->getVariableDbgInfo()) {
1147 Processed.insert(VI.Var);
1148 DIVariable DV(VI.Var);
1149 LexicalScope *Scope = LScopes.findLexicalScope(VI.Loc);
1151 // If variable scope is not found then skip this variable.
1155 DbgVariable *AbsDbgVariable = findAbstractVariable(DV, VI.Loc);
1156 DbgVariable *RegVar = new DbgVariable(DV, AbsDbgVariable, this);
1157 RegVar->setFrameIndex(VI.Slot);
1158 if (!addCurrentFnArgument(RegVar, Scope))
1159 addScopeVariable(Scope, RegVar);
1161 AbsDbgVariable->setFrameIndex(VI.Slot);
1165 // Get .debug_loc entry for the instruction range starting at MI.
1166 static DebugLocEntry::Value getDebugLocValue(const MachineInstr *MI) {
1167 const MDNode *Var = MI->getDebugVariable();
1169 assert(MI->getNumOperands() == 3);
1170 if (MI->getOperand(0).isReg()) {
1171 MachineLocation MLoc;
1172 // If the second operand is an immediate, this is a
1173 // register-indirect address.
1174 if (!MI->getOperand(1).isImm())
1175 MLoc.set(MI->getOperand(0).getReg());
1177 MLoc.set(MI->getOperand(0).getReg(), MI->getOperand(1).getImm());
1178 return DebugLocEntry::Value(Var, MLoc);
1180 if (MI->getOperand(0).isImm())
1181 return DebugLocEntry::Value(Var, MI->getOperand(0).getImm());
1182 if (MI->getOperand(0).isFPImm())
1183 return DebugLocEntry::Value(Var, MI->getOperand(0).getFPImm());
1184 if (MI->getOperand(0).isCImm())
1185 return DebugLocEntry::Value(Var, MI->getOperand(0).getCImm());
1187 llvm_unreachable("Unexpected 3 operand DBG_VALUE instruction!");
1190 // Find variables for each lexical scope.
1192 DwarfDebug::collectVariableInfo(SmallPtrSet<const MDNode *, 16> &Processed) {
1193 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1194 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1196 // Grab the variable info that was squirreled away in the MMI side-table.
1197 collectVariableInfoFromMMITable(Processed);
1199 for (const MDNode *Var : UserVariables) {
1200 if (Processed.count(Var))
1203 // History contains relevant DBG_VALUE instructions for Var and instructions
1205 SmallVectorImpl<const MachineInstr *> &History = DbgValues[Var];
1206 if (History.empty())
1208 const MachineInstr *MInsn = History.front();
1211 LexicalScope *Scope = nullptr;
1212 if (DV.getTag() == dwarf::DW_TAG_arg_variable &&
1213 DISubprogram(DV.getContext()).describes(CurFn->getFunction()))
1214 Scope = LScopes.getCurrentFunctionScope();
1215 else if (MDNode *IA = DV.getInlinedAt())
1216 Scope = LScopes.findInlinedScope(DebugLoc::getFromDILocation(IA));
1218 Scope = LScopes.findLexicalScope(cast<MDNode>(DV->getOperand(1)));
1219 // If variable scope is not found then skip this variable.
1223 Processed.insert(DV);
1224 assert(MInsn->isDebugValue() && "History must begin with debug value");
1225 DbgVariable *AbsVar = findAbstractVariable(DV, MInsn->getDebugLoc());
1226 DbgVariable *RegVar = new DbgVariable(DV, AbsVar, this);
1227 if (!addCurrentFnArgument(RegVar, Scope))
1228 addScopeVariable(Scope, RegVar);
1230 AbsVar->setMInsn(MInsn);
1232 // Simplify ranges that are fully coalesced.
1233 if (History.size() <= 1 ||
1234 (History.size() == 2 && MInsn->isIdenticalTo(History.back()))) {
1235 RegVar->setMInsn(MInsn);
1239 // Handle multiple DBG_VALUE instructions describing one variable.
1240 RegVar->setDotDebugLocOffset(DotDebugLocEntries.size());
1242 DotDebugLocEntries.resize(DotDebugLocEntries.size() + 1);
1243 DebugLocList &LocList = DotDebugLocEntries.back();
1245 Asm->GetTempSymbol("debug_loc", DotDebugLocEntries.size() - 1);
1246 SmallVector<DebugLocEntry, 4> &DebugLoc = LocList.List;
1247 for (SmallVectorImpl<const MachineInstr *>::const_iterator
1248 HI = History.begin(),
1251 const MachineInstr *Begin = *HI;
1252 assert(Begin->isDebugValue() && "Invalid History entry");
1254 // Check if DBG_VALUE is truncating a range.
1255 if (Begin->getNumOperands() > 1 && Begin->getOperand(0).isReg() &&
1256 !Begin->getOperand(0).getReg())
1259 // Compute the range for a register location.
1260 const MCSymbol *FLabel = getLabelBeforeInsn(Begin);
1261 const MCSymbol *SLabel = nullptr;
1264 // If Begin is the last instruction in History then its value is valid
1265 // until the end of the function.
1266 SLabel = FunctionEndSym;
1268 const MachineInstr *End = HI[1];
1269 DEBUG(dbgs() << "DotDebugLoc Pair:\n"
1270 << "\t" << *Begin << "\t" << *End << "\n");
1271 if (End->isDebugValue())
1272 SLabel = getLabelBeforeInsn(End);
1274 // End is a normal instruction clobbering the range.
1275 SLabel = getLabelAfterInsn(End);
1276 assert(SLabel && "Forgot label after clobber instruction");
1281 // The value is valid until the next DBG_VALUE or clobber.
1282 DebugLocEntry Loc(FLabel, SLabel, getDebugLocValue(Begin), TheCU);
1283 if (DebugLoc.empty() || !DebugLoc.back().Merge(Loc))
1284 DebugLoc.push_back(std::move(Loc));
1288 // Collect info for variables that were optimized out.
1289 DIArray Variables = DISubprogram(FnScope->getScopeNode()).getVariables();
1290 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1291 DIVariable DV(Variables.getElement(i));
1292 if (!DV || !DV.isVariable() || !Processed.insert(DV))
1294 if (LexicalScope *Scope = LScopes.findLexicalScope(DV.getContext()))
1295 addScopeVariable(Scope, new DbgVariable(DV, nullptr, this));
1299 // Return Label preceding the instruction.
1300 MCSymbol *DwarfDebug::getLabelBeforeInsn(const MachineInstr *MI) {
1301 MCSymbol *Label = LabelsBeforeInsn.lookup(MI);
1302 assert(Label && "Didn't insert label before instruction");
1306 // Return Label immediately following the instruction.
1307 MCSymbol *DwarfDebug::getLabelAfterInsn(const MachineInstr *MI) {
1308 return LabelsAfterInsn.lookup(MI);
1311 // Process beginning of an instruction.
1312 void DwarfDebug::beginInstruction(const MachineInstr *MI) {
1313 assert(CurMI == nullptr);
1315 // Check if source location changes, but ignore DBG_VALUE locations.
1316 if (!MI->isDebugValue()) {
1317 DebugLoc DL = MI->getDebugLoc();
1318 if (DL != PrevInstLoc && (!DL.isUnknown() || UnknownLocations)) {
1321 if (DL == PrologEndLoc) {
1322 Flags |= DWARF2_FLAG_PROLOGUE_END;
1323 PrologEndLoc = DebugLoc();
1325 if (PrologEndLoc.isUnknown())
1326 Flags |= DWARF2_FLAG_IS_STMT;
1328 if (!DL.isUnknown()) {
1329 const MDNode *Scope = DL.getScope(Asm->MF->getFunction()->getContext());
1330 recordSourceLine(DL.getLine(), DL.getCol(), Scope, Flags);
1332 recordSourceLine(0, 0, nullptr, 0);
1336 // Insert labels where requested.
1337 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1338 LabelsBeforeInsn.find(MI);
1341 if (I == LabelsBeforeInsn.end())
1344 // Label already assigned.
1349 PrevLabel = MMI->getContext().CreateTempSymbol();
1350 Asm->OutStreamer.EmitLabel(PrevLabel);
1352 I->second = PrevLabel;
1355 // Process end of an instruction.
1356 void DwarfDebug::endInstruction() {
1357 assert(CurMI != nullptr);
1358 // Don't create a new label after DBG_VALUE instructions.
1359 // They don't generate code.
1360 if (!CurMI->isDebugValue())
1361 PrevLabel = nullptr;
1363 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1364 LabelsAfterInsn.find(CurMI);
1368 if (I == LabelsAfterInsn.end())
1371 // Label already assigned.
1375 // We need a label after this instruction.
1377 PrevLabel = MMI->getContext().CreateTempSymbol();
1378 Asm->OutStreamer.EmitLabel(PrevLabel);
1380 I->second = PrevLabel;
1383 // Each LexicalScope has first instruction and last instruction to mark
1384 // beginning and end of a scope respectively. Create an inverse map that list
1385 // scopes starts (and ends) with an instruction. One instruction may start (or
1386 // end) multiple scopes. Ignore scopes that are not reachable.
1387 void DwarfDebug::identifyScopeMarkers() {
1388 SmallVector<LexicalScope *, 4> WorkList;
1389 WorkList.push_back(LScopes.getCurrentFunctionScope());
1390 while (!WorkList.empty()) {
1391 LexicalScope *S = WorkList.pop_back_val();
1393 const SmallVectorImpl<LexicalScope *> &Children = S->getChildren();
1394 if (!Children.empty())
1395 WorkList.append(Children.begin(), Children.end());
1397 if (S->isAbstractScope())
1400 for (const InsnRange &R : S->getRanges()) {
1401 assert(R.first && "InsnRange does not have first instruction!");
1402 assert(R.second && "InsnRange does not have second instruction!");
1403 requestLabelBeforeInsn(R.first);
1404 requestLabelAfterInsn(R.second);
1409 // Gather pre-function debug information. Assumes being called immediately
1410 // after the function entry point has been emitted.
1411 void DwarfDebug::beginFunction(const MachineFunction *MF) {
1414 // If there's no debug info for the function we're not going to do anything.
1415 if (!MMI->hasDebugInfo())
1418 // Grab the lexical scopes for the function, if we don't have any of those
1419 // then we're not going to be able to do anything.
1420 LScopes.initialize(*MF);
1421 if (LScopes.empty())
1424 assert(UserVariables.empty() && DbgValues.empty() && "Maps weren't cleaned");
1426 // Make sure that each lexical scope will have a begin/end label.
1427 identifyScopeMarkers();
1429 // Set DwarfDwarfCompileUnitID in MCContext to the Compile Unit this function
1430 // belongs to so that we add to the correct per-cu line table in the
1432 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1433 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1434 assert(TheCU && "Unable to find compile unit!");
1435 if (Asm->OutStreamer.hasRawTextSupport())
1436 // Use a single line table if we are generating assembly.
1437 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1439 Asm->OutStreamer.getContext().setDwarfCompileUnitID(TheCU->getUniqueID());
1441 // Emit a label for the function so that we have a beginning address.
1442 FunctionBeginSym = Asm->GetTempSymbol("func_begin", Asm->getFunctionNumber());
1443 // Assumes in correct section after the entry point.
1444 Asm->OutStreamer.EmitLabel(FunctionBeginSym);
1446 // Collect user variables, find the end of the prologue.
1447 for (const auto &MBB : *MF) {
1448 for (const auto &MI : MBB) {
1449 if (MI.isDebugValue()) {
1450 assert(MI.getNumOperands() > 1 && "Invalid machine instruction!");
1451 // Keep track of user variables in order of appearance. Store the set
1452 // of variables we've already seen as a set of keys in DbgValues.
1453 const MDNode *Var = MI.getDebugVariable();
1454 auto IterPair = DbgValues.insert(
1455 std::make_pair(Var, SmallVector<const MachineInstr *, 4>()));
1456 if (IterPair.second)
1457 UserVariables.push_back(Var);
1458 } else if (!MI.getFlag(MachineInstr::FrameSetup) &&
1459 PrologEndLoc.isUnknown() && !MI.getDebugLoc().isUnknown()) {
1460 // First known non-DBG_VALUE and non-frame setup location marks
1461 // the beginning of the function body.
1462 PrologEndLoc = MI.getDebugLoc();
1467 // Calculate history for local variables.
1468 calculateDbgValueHistory(MF, Asm->TM.getRegisterInfo(), DbgValues);
1470 // Request labels for the full history.
1471 for (auto &I : DbgValues) {
1472 const SmallVectorImpl<const MachineInstr *> &History = I.second;
1473 if (History.empty())
1476 // The first mention of a function argument gets the FunctionBeginSym
1477 // label, so arguments are visible when breaking at function entry.
1478 DIVariable DV(I.first);
1479 if (DV.isVariable() && DV.getTag() == dwarf::DW_TAG_arg_variable &&
1480 getDISubprogram(DV.getContext()).describes(MF->getFunction()))
1481 LabelsBeforeInsn[History.front()] = FunctionBeginSym;
1483 for (const MachineInstr *MI : History) {
1484 if (MI->isDebugValue())
1485 requestLabelBeforeInsn(MI);
1487 requestLabelAfterInsn(MI);
1491 PrevInstLoc = DebugLoc();
1492 PrevLabel = FunctionBeginSym;
1494 // Record beginning of function.
1495 if (!PrologEndLoc.isUnknown()) {
1496 DebugLoc FnStartDL =
1497 PrologEndLoc.getFnDebugLoc(MF->getFunction()->getContext());
1499 FnStartDL.getLine(), FnStartDL.getCol(),
1500 FnStartDL.getScope(MF->getFunction()->getContext()),
1501 // We'd like to list the prologue as "not statements" but GDB behaves
1502 // poorly if we do that. Revisit this with caution/GDB (7.5+) testing.
1503 DWARF2_FLAG_IS_STMT);
1507 void DwarfDebug::addScopeVariable(LexicalScope *LS, DbgVariable *Var) {
1508 SmallVectorImpl<DbgVariable *> &Vars = ScopeVariables[LS];
1509 DIVariable DV = Var->getVariable();
1510 // Variables with positive arg numbers are parameters.
1511 if (unsigned ArgNum = DV.getArgNumber()) {
1512 // Keep all parameters in order at the start of the variable list to ensure
1513 // function types are correct (no out-of-order parameters)
1515 // This could be improved by only doing it for optimized builds (unoptimized
1516 // builds have the right order to begin with), searching from the back (this
1517 // would catch the unoptimized case quickly), or doing a binary search
1518 // rather than linear search.
1519 SmallVectorImpl<DbgVariable *>::iterator I = Vars.begin();
1520 while (I != Vars.end()) {
1521 unsigned CurNum = (*I)->getVariable().getArgNumber();
1522 // A local (non-parameter) variable has been found, insert immediately
1526 // A later indexed parameter has been found, insert immediately before it.
1527 if (CurNum > ArgNum)
1531 Vars.insert(I, Var);
1535 Vars.push_back(Var);
1538 // Gather and emit post-function debug information.
1539 void DwarfDebug::endFunction(const MachineFunction *MF) {
1540 // Every beginFunction(MF) call should be followed by an endFunction(MF) call,
1541 // though the beginFunction may not be called at all.
1542 // We should handle both cases.
1546 assert(CurFn == MF);
1547 assert(CurFn != nullptr);
1549 if (!MMI->hasDebugInfo() || LScopes.empty()) {
1550 // If we don't have a lexical scope for this function then there will
1551 // be a hole in the range information. Keep note of this by setting the
1552 // previously used section to nullptr.
1553 PrevSection = nullptr;
1559 // Define end label for subprogram.
1560 FunctionEndSym = Asm->GetTempSymbol("func_end", Asm->getFunctionNumber());
1561 // Assumes in correct section after the entry point.
1562 Asm->OutStreamer.EmitLabel(FunctionEndSym);
1564 // Set DwarfDwarfCompileUnitID in MCContext to default value.
1565 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1567 SmallPtrSet<const MDNode *, 16> ProcessedVars;
1568 collectVariableInfo(ProcessedVars);
1570 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1571 DwarfCompileUnit &TheCU = *SPMap.lookup(FnScope->getScopeNode());
1573 // Construct abstract scopes.
1574 for (LexicalScope *AScope : LScopes.getAbstractScopesList()) {
1575 DISubprogram SP(AScope->getScopeNode());
1576 if (SP.isSubprogram()) {
1577 // Collect info for variables that were optimized out.
1578 DIArray Variables = SP.getVariables();
1579 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1580 DIVariable DV(Variables.getElement(i));
1581 if (!DV || !DV.isVariable() || !ProcessedVars.insert(DV))
1583 // Check that DbgVariable for DV wasn't created earlier, when
1584 // findAbstractVariable() was called for inlined instance of DV.
1585 LLVMContext &Ctx = DV->getContext();
1586 DIVariable CleanDV = cleanseInlinedVariable(DV, Ctx);
1587 if (AbstractVariables.lookup(CleanDV))
1589 if (LexicalScope *Scope = LScopes.findAbstractScope(DV.getContext()))
1590 addScopeVariable(Scope, new DbgVariable(DV, nullptr, this));
1593 if (ProcessedSPNodes.count(AScope->getScopeNode()) == 0)
1594 constructAbstractSubprogramScopeDIE(TheCU, AScope);
1597 DIE &CurFnDIE = constructSubprogramScopeDIE(TheCU, FnScope);
1598 if (!CurFn->getTarget().Options.DisableFramePointerElim(*CurFn))
1599 TheCU.addFlag(CurFnDIE, dwarf::DW_AT_APPLE_omit_frame_ptr);
1601 // Add the range of this function to the list of ranges for the CU.
1602 RangeSpan Span(FunctionBeginSym, FunctionEndSym);
1603 TheCU.addRange(std::move(Span));
1604 PrevSection = Asm->getCurrentSection();
1608 for (auto &I : ScopeVariables)
1609 DeleteContainerPointers(I.second);
1610 ScopeVariables.clear();
1611 DeleteContainerPointers(CurrentFnArguments);
1612 UserVariables.clear();
1614 AbstractVariables.clear();
1615 LabelsBeforeInsn.clear();
1616 LabelsAfterInsn.clear();
1617 PrevLabel = nullptr;
1621 // Register a source line with debug info. Returns the unique label that was
1622 // emitted and which provides correspondence to the source line list.
1623 void DwarfDebug::recordSourceLine(unsigned Line, unsigned Col, const MDNode *S,
1628 unsigned Discriminator = 0;
1630 DIDescriptor Scope(S);
1632 if (Scope.isCompileUnit()) {
1633 DICompileUnit CU(S);
1634 Fn = CU.getFilename();
1635 Dir = CU.getDirectory();
1636 } else if (Scope.isFile()) {
1638 Fn = F.getFilename();
1639 Dir = F.getDirectory();
1640 } else if (Scope.isSubprogram()) {
1642 Fn = SP.getFilename();
1643 Dir = SP.getDirectory();
1644 } else if (Scope.isLexicalBlockFile()) {
1645 DILexicalBlockFile DBF(S);
1646 Fn = DBF.getFilename();
1647 Dir = DBF.getDirectory();
1648 } else if (Scope.isLexicalBlock()) {
1649 DILexicalBlock DB(S);
1650 Fn = DB.getFilename();
1651 Dir = DB.getDirectory();
1652 Discriminator = DB.getDiscriminator();
1654 llvm_unreachable("Unexpected scope info");
1656 unsigned CUID = Asm->OutStreamer.getContext().getDwarfCompileUnitID();
1657 Src = static_cast<DwarfCompileUnit &>(*InfoHolder.getUnits()[CUID])
1658 .getOrCreateSourceID(Fn, Dir);
1660 Asm->OutStreamer.EmitDwarfLocDirective(Src, Line, Col, Flags, 0,
1664 //===----------------------------------------------------------------------===//
1666 //===----------------------------------------------------------------------===//
1668 // Emit initial Dwarf sections with a label at the start of each one.
1669 void DwarfDebug::emitSectionLabels() {
1670 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
1672 // Dwarf sections base addresses.
1673 DwarfInfoSectionSym =
1674 emitSectionSym(Asm, TLOF.getDwarfInfoSection(), "section_info");
1675 if (useSplitDwarf())
1676 DwarfInfoDWOSectionSym =
1677 emitSectionSym(Asm, TLOF.getDwarfInfoDWOSection(), "section_info_dwo");
1678 DwarfAbbrevSectionSym =
1679 emitSectionSym(Asm, TLOF.getDwarfAbbrevSection(), "section_abbrev");
1680 if (useSplitDwarf())
1681 DwarfAbbrevDWOSectionSym = emitSectionSym(
1682 Asm, TLOF.getDwarfAbbrevDWOSection(), "section_abbrev_dwo");
1683 if (GenerateARangeSection)
1684 emitSectionSym(Asm, TLOF.getDwarfARangesSection());
1686 DwarfLineSectionSym =
1687 emitSectionSym(Asm, TLOF.getDwarfLineSection(), "section_line");
1688 if (GenerateGnuPubSections) {
1689 DwarfGnuPubNamesSectionSym =
1690 emitSectionSym(Asm, TLOF.getDwarfGnuPubNamesSection());
1691 DwarfGnuPubTypesSectionSym =
1692 emitSectionSym(Asm, TLOF.getDwarfGnuPubTypesSection());
1693 } else if (HasDwarfPubSections) {
1694 emitSectionSym(Asm, TLOF.getDwarfPubNamesSection());
1695 emitSectionSym(Asm, TLOF.getDwarfPubTypesSection());
1698 DwarfStrSectionSym =
1699 emitSectionSym(Asm, TLOF.getDwarfStrSection(), "info_string");
1700 if (useSplitDwarf()) {
1701 DwarfStrDWOSectionSym =
1702 emitSectionSym(Asm, TLOF.getDwarfStrDWOSection(), "skel_string");
1703 DwarfAddrSectionSym =
1704 emitSectionSym(Asm, TLOF.getDwarfAddrSection(), "addr_sec");
1705 DwarfDebugLocSectionSym =
1706 emitSectionSym(Asm, TLOF.getDwarfLocDWOSection(), "skel_loc");
1708 DwarfDebugLocSectionSym =
1709 emitSectionSym(Asm, TLOF.getDwarfLocSection(), "section_debug_loc");
1710 DwarfDebugRangeSectionSym =
1711 emitSectionSym(Asm, TLOF.getDwarfRangesSection(), "debug_range");
1714 // Recursively emits a debug information entry.
1715 void DwarfDebug::emitDIE(DIE &Die) {
1716 // Get the abbreviation for this DIE.
1717 const DIEAbbrev &Abbrev = Die.getAbbrev();
1719 // Emit the code (index) for the abbreviation.
1720 if (Asm->isVerbose())
1721 Asm->OutStreamer.AddComment("Abbrev [" + Twine(Abbrev.getNumber()) +
1722 "] 0x" + Twine::utohexstr(Die.getOffset()) +
1723 ":0x" + Twine::utohexstr(Die.getSize()) + " " +
1724 dwarf::TagString(Abbrev.getTag()));
1725 Asm->EmitULEB128(Abbrev.getNumber());
1727 const SmallVectorImpl<DIEValue *> &Values = Die.getValues();
1728 const SmallVectorImpl<DIEAbbrevData> &AbbrevData = Abbrev.getData();
1730 // Emit the DIE attribute values.
1731 for (unsigned i = 0, N = Values.size(); i < N; ++i) {
1732 dwarf::Attribute Attr = AbbrevData[i].getAttribute();
1733 dwarf::Form Form = AbbrevData[i].getForm();
1734 assert(Form && "Too many attributes for DIE (check abbreviation)");
1736 if (Asm->isVerbose()) {
1737 Asm->OutStreamer.AddComment(dwarf::AttributeString(Attr));
1738 if (Attr == dwarf::DW_AT_accessibility)
1739 Asm->OutStreamer.AddComment(dwarf::AccessibilityString(
1740 cast<DIEInteger>(Values[i])->getValue()));
1743 // Emit an attribute using the defined form.
1744 Values[i]->EmitValue(Asm, Form);
1747 // Emit the DIE children if any.
1748 if (Abbrev.hasChildren()) {
1749 for (auto &Child : Die.getChildren())
1752 Asm->OutStreamer.AddComment("End Of Children Mark");
1757 // Emit the debug info section.
1758 void DwarfDebug::emitDebugInfo() {
1759 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1761 Holder.emitUnits(this, DwarfAbbrevSectionSym);
1764 // Emit the abbreviation section.
1765 void DwarfDebug::emitAbbreviations() {
1766 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1768 Holder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevSection());
1771 // Emit the last address of the section and the end of the line matrix.
1772 void DwarfDebug::emitEndOfLineMatrix(unsigned SectionEnd) {
1773 // Define last address of section.
1774 Asm->OutStreamer.AddComment("Extended Op");
1777 Asm->OutStreamer.AddComment("Op size");
1778 Asm->EmitInt8(Asm->getDataLayout().getPointerSize() + 1);
1779 Asm->OutStreamer.AddComment("DW_LNE_set_address");
1780 Asm->EmitInt8(dwarf::DW_LNE_set_address);
1782 Asm->OutStreamer.AddComment("Section end label");
1784 Asm->OutStreamer.EmitSymbolValue(
1785 Asm->GetTempSymbol("section_end", SectionEnd),
1786 Asm->getDataLayout().getPointerSize());
1788 // Mark end of matrix.
1789 Asm->OutStreamer.AddComment("DW_LNE_end_sequence");
1795 // Emit visible names into a hashed accelerator table section.
1796 void DwarfDebug::emitAccelNames() {
1797 AccelNames.FinalizeTable(Asm, "Names");
1798 Asm->OutStreamer.SwitchSection(
1799 Asm->getObjFileLowering().getDwarfAccelNamesSection());
1800 MCSymbol *SectionBegin = Asm->GetTempSymbol("names_begin");
1801 Asm->OutStreamer.EmitLabel(SectionBegin);
1803 // Emit the full data.
1804 AccelNames.Emit(Asm, SectionBegin, &InfoHolder);
1807 // Emit objective C classes and categories into a hashed accelerator table
1809 void DwarfDebug::emitAccelObjC() {
1810 AccelObjC.FinalizeTable(Asm, "ObjC");
1811 Asm->OutStreamer.SwitchSection(
1812 Asm->getObjFileLowering().getDwarfAccelObjCSection());
1813 MCSymbol *SectionBegin = Asm->GetTempSymbol("objc_begin");
1814 Asm->OutStreamer.EmitLabel(SectionBegin);
1816 // Emit the full data.
1817 AccelObjC.Emit(Asm, SectionBegin, &InfoHolder);
1820 // Emit namespace dies into a hashed accelerator table.
1821 void DwarfDebug::emitAccelNamespaces() {
1822 AccelNamespace.FinalizeTable(Asm, "namespac");
1823 Asm->OutStreamer.SwitchSection(
1824 Asm->getObjFileLowering().getDwarfAccelNamespaceSection());
1825 MCSymbol *SectionBegin = Asm->GetTempSymbol("namespac_begin");
1826 Asm->OutStreamer.EmitLabel(SectionBegin);
1828 // Emit the full data.
1829 AccelNamespace.Emit(Asm, SectionBegin, &InfoHolder);
1832 // Emit type dies into a hashed accelerator table.
1833 void DwarfDebug::emitAccelTypes() {
1835 AccelTypes.FinalizeTable(Asm, "types");
1836 Asm->OutStreamer.SwitchSection(
1837 Asm->getObjFileLowering().getDwarfAccelTypesSection());
1838 MCSymbol *SectionBegin = Asm->GetTempSymbol("types_begin");
1839 Asm->OutStreamer.EmitLabel(SectionBegin);
1841 // Emit the full data.
1842 AccelTypes.Emit(Asm, SectionBegin, &InfoHolder);
1845 // Public name handling.
1846 // The format for the various pubnames:
1848 // dwarf pubnames - offset/name pairs where the offset is the offset into the CU
1849 // for the DIE that is named.
1851 // gnu pubnames - offset/index value/name tuples where the offset is the offset
1852 // into the CU and the index value is computed according to the type of value
1853 // for the DIE that is named.
1855 // For type units the offset is the offset of the skeleton DIE. For split dwarf
1856 // it's the offset within the debug_info/debug_types dwo section, however, the
1857 // reference in the pubname header doesn't change.
1859 /// computeIndexValue - Compute the gdb index value for the DIE and CU.
1860 static dwarf::PubIndexEntryDescriptor computeIndexValue(DwarfUnit *CU,
1862 dwarf::GDBIndexEntryLinkage Linkage = dwarf::GIEL_STATIC;
1864 // We could have a specification DIE that has our most of our knowledge,
1865 // look for that now.
1866 DIEValue *SpecVal = Die->findAttribute(dwarf::DW_AT_specification);
1868 DIE &SpecDIE = cast<DIEEntry>(SpecVal)->getEntry();
1869 if (SpecDIE.findAttribute(dwarf::DW_AT_external))
1870 Linkage = dwarf::GIEL_EXTERNAL;
1871 } else if (Die->findAttribute(dwarf::DW_AT_external))
1872 Linkage = dwarf::GIEL_EXTERNAL;
1874 switch (Die->getTag()) {
1875 case dwarf::DW_TAG_class_type:
1876 case dwarf::DW_TAG_structure_type:
1877 case dwarf::DW_TAG_union_type:
1878 case dwarf::DW_TAG_enumeration_type:
1879 return dwarf::PubIndexEntryDescriptor(
1880 dwarf::GIEK_TYPE, CU->getLanguage() != dwarf::DW_LANG_C_plus_plus
1881 ? dwarf::GIEL_STATIC
1882 : dwarf::GIEL_EXTERNAL);
1883 case dwarf::DW_TAG_typedef:
1884 case dwarf::DW_TAG_base_type:
1885 case dwarf::DW_TAG_subrange_type:
1886 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_TYPE, dwarf::GIEL_STATIC);
1887 case dwarf::DW_TAG_namespace:
1888 return dwarf::GIEK_TYPE;
1889 case dwarf::DW_TAG_subprogram:
1890 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_FUNCTION, Linkage);
1891 case dwarf::DW_TAG_constant:
1892 case dwarf::DW_TAG_variable:
1893 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE, Linkage);
1894 case dwarf::DW_TAG_enumerator:
1895 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE,
1896 dwarf::GIEL_STATIC);
1898 return dwarf::GIEK_NONE;
1902 /// emitDebugPubNames - Emit visible names into a debug pubnames section.
1904 void DwarfDebug::emitDebugPubNames(bool GnuStyle) {
1905 const MCSection *PSec =
1906 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubNamesSection()
1907 : Asm->getObjFileLowering().getDwarfPubNamesSection();
1909 emitDebugPubSection(GnuStyle, PSec, "Names", &DwarfUnit::getGlobalNames);
1912 void DwarfDebug::emitDebugPubSection(
1913 bool GnuStyle, const MCSection *PSec, StringRef Name,
1914 const StringMap<const DIE *> &(DwarfUnit::*Accessor)() const) {
1915 for (const auto &NU : CUMap) {
1916 DwarfCompileUnit *TheU = NU.second;
1918 const auto &Globals = (TheU->*Accessor)();
1920 if (Globals.empty())
1923 if (auto Skeleton = static_cast<DwarfCompileUnit *>(TheU->getSkeleton()))
1925 unsigned ID = TheU->getUniqueID();
1927 // Start the dwarf pubnames section.
1928 Asm->OutStreamer.SwitchSection(PSec);
1931 Asm->OutStreamer.AddComment("Length of Public " + Name + " Info");
1932 MCSymbol *BeginLabel = Asm->GetTempSymbol("pub" + Name + "_begin", ID);
1933 MCSymbol *EndLabel = Asm->GetTempSymbol("pub" + Name + "_end", ID);
1934 Asm->EmitLabelDifference(EndLabel, BeginLabel, 4);
1936 Asm->OutStreamer.EmitLabel(BeginLabel);
1938 Asm->OutStreamer.AddComment("DWARF Version");
1939 Asm->EmitInt16(dwarf::DW_PUBNAMES_VERSION);
1941 Asm->OutStreamer.AddComment("Offset of Compilation Unit Info");
1942 Asm->EmitSectionOffset(TheU->getLabelBegin(), TheU->getSectionSym());
1944 Asm->OutStreamer.AddComment("Compilation Unit Length");
1945 Asm->EmitLabelDifference(TheU->getLabelEnd(), TheU->getLabelBegin(), 4);
1947 // Emit the pubnames for this compilation unit.
1948 for (const auto &GI : Globals) {
1949 const char *Name = GI.getKeyData();
1950 const DIE *Entity = GI.second;
1952 Asm->OutStreamer.AddComment("DIE offset");
1953 Asm->EmitInt32(Entity->getOffset());
1956 dwarf::PubIndexEntryDescriptor Desc = computeIndexValue(TheU, Entity);
1957 Asm->OutStreamer.AddComment(
1958 Twine("Kind: ") + dwarf::GDBIndexEntryKindString(Desc.Kind) + ", " +
1959 dwarf::GDBIndexEntryLinkageString(Desc.Linkage));
1960 Asm->EmitInt8(Desc.toBits());
1963 Asm->OutStreamer.AddComment("External Name");
1964 Asm->OutStreamer.EmitBytes(StringRef(Name, GI.getKeyLength() + 1));
1967 Asm->OutStreamer.AddComment("End Mark");
1969 Asm->OutStreamer.EmitLabel(EndLabel);
1973 void DwarfDebug::emitDebugPubTypes(bool GnuStyle) {
1974 const MCSection *PSec =
1975 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubTypesSection()
1976 : Asm->getObjFileLowering().getDwarfPubTypesSection();
1978 emitDebugPubSection(GnuStyle, PSec, "Types", &DwarfUnit::getGlobalTypes);
1981 // Emit visible names into a debug str section.
1982 void DwarfDebug::emitDebugStr() {
1983 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1984 Holder.emitStrings(Asm->getObjFileLowering().getDwarfStrSection());
1987 void DwarfDebug::emitDebugLocEntry(ByteStreamer &Streamer,
1988 const DebugLocEntry &Entry) {
1989 assert(Entry.getValues().size() == 1 &&
1990 "multi-value entries are not supported yet.");
1991 const DebugLocEntry::Value Value = Entry.getValues()[0];
1992 DIVariable DV(Value.getVariable());
1993 if (Value.isInt()) {
1994 DIBasicType BTy(resolve(DV.getType()));
1995 if (BTy.Verify() && (BTy.getEncoding() == dwarf::DW_ATE_signed ||
1996 BTy.getEncoding() == dwarf::DW_ATE_signed_char)) {
1997 Streamer.EmitInt8(dwarf::DW_OP_consts, "DW_OP_consts");
1998 Streamer.EmitSLEB128(Value.getInt());
2000 Streamer.EmitInt8(dwarf::DW_OP_constu, "DW_OP_constu");
2001 Streamer.EmitULEB128(Value.getInt());
2003 } else if (Value.isLocation()) {
2004 MachineLocation Loc = Value.getLoc();
2005 if (!DV.hasComplexAddress())
2007 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2009 // Complex address entry.
2010 unsigned N = DV.getNumAddrElements();
2012 if (N >= 2 && DV.getAddrElement(0) == DIBuilder::OpPlus) {
2013 if (Loc.getOffset()) {
2015 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2016 Streamer.EmitInt8(dwarf::DW_OP_deref, "DW_OP_deref");
2017 Streamer.EmitInt8(dwarf::DW_OP_plus_uconst, "DW_OP_plus_uconst");
2018 Streamer.EmitSLEB128(DV.getAddrElement(1));
2020 // If first address element is OpPlus then emit
2021 // DW_OP_breg + Offset instead of DW_OP_reg + Offset.
2022 MachineLocation TLoc(Loc.getReg(), DV.getAddrElement(1));
2023 Asm->EmitDwarfRegOp(Streamer, TLoc, DV.isIndirect());
2027 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2030 // Emit remaining complex address elements.
2031 for (; i < N; ++i) {
2032 uint64_t Element = DV.getAddrElement(i);
2033 if (Element == DIBuilder::OpPlus) {
2034 Streamer.EmitInt8(dwarf::DW_OP_plus_uconst, "DW_OP_plus_uconst");
2035 Streamer.EmitULEB128(DV.getAddrElement(++i));
2036 } else if (Element == DIBuilder::OpDeref) {
2038 Streamer.EmitInt8(dwarf::DW_OP_deref, "DW_OP_deref");
2040 llvm_unreachable("unknown Opcode found in complex address");
2044 // else ... ignore constant fp. There is not any good way to
2045 // to represent them here in dwarf.
2049 void DwarfDebug::emitDebugLocEntryLocation(const DebugLocEntry &Entry) {
2050 Asm->OutStreamer.AddComment("Loc expr size");
2051 MCSymbol *begin = Asm->OutStreamer.getContext().CreateTempSymbol();
2052 MCSymbol *end = Asm->OutStreamer.getContext().CreateTempSymbol();
2053 Asm->EmitLabelDifference(end, begin, 2);
2054 Asm->OutStreamer.EmitLabel(begin);
2056 APByteStreamer Streamer(*Asm);
2057 emitDebugLocEntry(Streamer, Entry);
2059 Asm->OutStreamer.EmitLabel(end);
2062 // Emit locations into the debug loc section.
2063 void DwarfDebug::emitDebugLoc() {
2064 // Start the dwarf loc section.
2065 Asm->OutStreamer.SwitchSection(
2066 Asm->getObjFileLowering().getDwarfLocSection());
2067 unsigned char Size = Asm->getDataLayout().getPointerSize();
2068 for (const auto &DebugLoc : DotDebugLocEntries) {
2069 Asm->OutStreamer.EmitLabel(DebugLoc.Label);
2070 for (const auto &Entry : DebugLoc.List) {
2071 // Set up the range. This range is relative to the entry point of the
2072 // compile unit. This is a hard coded 0 for low_pc when we're emitting
2073 // ranges, or the DW_AT_low_pc on the compile unit otherwise.
2074 const DwarfCompileUnit *CU = Entry.getCU();
2075 if (CU->getRanges().size() == 1) {
2076 // Grab the begin symbol from the first range as our base.
2077 const MCSymbol *Base = CU->getRanges()[0].getStart();
2078 Asm->EmitLabelDifference(Entry.getBeginSym(), Base, Size);
2079 Asm->EmitLabelDifference(Entry.getEndSym(), Base, Size);
2081 Asm->OutStreamer.EmitSymbolValue(Entry.getBeginSym(), Size);
2082 Asm->OutStreamer.EmitSymbolValue(Entry.getEndSym(), Size);
2085 emitDebugLocEntryLocation(Entry);
2087 Asm->OutStreamer.EmitIntValue(0, Size);
2088 Asm->OutStreamer.EmitIntValue(0, Size);
2092 void DwarfDebug::emitDebugLocDWO() {
2093 Asm->OutStreamer.SwitchSection(
2094 Asm->getObjFileLowering().getDwarfLocDWOSection());
2095 for (const auto &DebugLoc : DotDebugLocEntries) {
2096 Asm->OutStreamer.EmitLabel(DebugLoc.Label);
2097 for (const auto &Entry : DebugLoc.List) {
2098 // Just always use start_length for now - at least that's one address
2099 // rather than two. We could get fancier and try to, say, reuse an
2100 // address we know we've emitted elsewhere (the start of the function?
2101 // The start of the CU or CU subrange that encloses this range?)
2102 Asm->EmitInt8(dwarf::DW_LLE_start_length_entry);
2103 unsigned idx = AddrPool.getIndex(Entry.getBeginSym());
2104 Asm->EmitULEB128(idx);
2105 Asm->EmitLabelDifference(Entry.getEndSym(), Entry.getBeginSym(), 4);
2107 emitDebugLocEntryLocation(Entry);
2109 Asm->EmitInt8(dwarf::DW_LLE_end_of_list_entry);
2114 const MCSymbol *Start, *End;
2117 // Emit a debug aranges section, containing a CU lookup for any
2118 // address we can tie back to a CU.
2119 void DwarfDebug::emitDebugARanges() {
2120 // Start the dwarf aranges section.
2121 Asm->OutStreamer.SwitchSection(
2122 Asm->getObjFileLowering().getDwarfARangesSection());
2124 typedef DenseMap<DwarfCompileUnit *, std::vector<ArangeSpan>> SpansType;
2128 // Build a list of sections used.
2129 std::vector<const MCSection *> Sections;
2130 for (const auto &it : SectionMap) {
2131 const MCSection *Section = it.first;
2132 Sections.push_back(Section);
2135 // Sort the sections into order.
2136 // This is only done to ensure consistent output order across different runs.
2137 std::sort(Sections.begin(), Sections.end(), SectionSort);
2139 // Build a set of address spans, sorted by CU.
2140 for (const MCSection *Section : Sections) {
2141 SmallVector<SymbolCU, 8> &List = SectionMap[Section];
2142 if (List.size() < 2)
2145 // Sort the symbols by offset within the section.
2146 std::sort(List.begin(), List.end(),
2147 [&](const SymbolCU &A, const SymbolCU &B) {
2148 unsigned IA = A.Sym ? Asm->OutStreamer.GetSymbolOrder(A.Sym) : 0;
2149 unsigned IB = B.Sym ? Asm->OutStreamer.GetSymbolOrder(B.Sym) : 0;
2151 // Symbols with no order assigned should be placed at the end.
2152 // (e.g. section end labels)
2160 // If we have no section (e.g. common), just write out
2161 // individual spans for each symbol.
2163 for (const SymbolCU &Cur : List) {
2165 Span.Start = Cur.Sym;
2168 Spans[Cur.CU].push_back(Span);
2171 // Build spans between each label.
2172 const MCSymbol *StartSym = List[0].Sym;
2173 for (size_t n = 1, e = List.size(); n < e; n++) {
2174 const SymbolCU &Prev = List[n - 1];
2175 const SymbolCU &Cur = List[n];
2177 // Try and build the longest span we can within the same CU.
2178 if (Cur.CU != Prev.CU) {
2180 Span.Start = StartSym;
2182 Spans[Prev.CU].push_back(Span);
2189 unsigned PtrSize = Asm->getDataLayout().getPointerSize();
2191 // Build a list of CUs used.
2192 std::vector<DwarfCompileUnit *> CUs;
2193 for (const auto &it : Spans) {
2194 DwarfCompileUnit *CU = it.first;
2198 // Sort the CU list (again, to ensure consistent output order).
2199 std::sort(CUs.begin(), CUs.end(), [](const DwarfUnit *A, const DwarfUnit *B) {
2200 return A->getUniqueID() < B->getUniqueID();
2203 // Emit an arange table for each CU we used.
2204 for (DwarfCompileUnit *CU : CUs) {
2205 std::vector<ArangeSpan> &List = Spans[CU];
2207 // Emit size of content not including length itself.
2208 unsigned ContentSize =
2209 sizeof(int16_t) + // DWARF ARange version number
2210 sizeof(int32_t) + // Offset of CU in the .debug_info section
2211 sizeof(int8_t) + // Pointer Size (in bytes)
2212 sizeof(int8_t); // Segment Size (in bytes)
2214 unsigned TupleSize = PtrSize * 2;
2216 // 7.20 in the Dwarf specs requires the table to be aligned to a tuple.
2218 OffsetToAlignment(sizeof(int32_t) + ContentSize, TupleSize);
2220 ContentSize += Padding;
2221 ContentSize += (List.size() + 1) * TupleSize;
2223 // For each compile unit, write the list of spans it covers.
2224 Asm->OutStreamer.AddComment("Length of ARange Set");
2225 Asm->EmitInt32(ContentSize);
2226 Asm->OutStreamer.AddComment("DWARF Arange version number");
2227 Asm->EmitInt16(dwarf::DW_ARANGES_VERSION);
2228 Asm->OutStreamer.AddComment("Offset Into Debug Info Section");
2229 Asm->EmitSectionOffset(CU->getLocalLabelBegin(), CU->getLocalSectionSym());
2230 Asm->OutStreamer.AddComment("Address Size (in bytes)");
2231 Asm->EmitInt8(PtrSize);
2232 Asm->OutStreamer.AddComment("Segment Size (in bytes)");
2235 Asm->OutStreamer.EmitFill(Padding, 0xff);
2237 for (const ArangeSpan &Span : List) {
2238 Asm->EmitLabelReference(Span.Start, PtrSize);
2240 // Calculate the size as being from the span start to it's end.
2242 Asm->EmitLabelDifference(Span.End, Span.Start, PtrSize);
2244 // For symbols without an end marker (e.g. common), we
2245 // write a single arange entry containing just that one symbol.
2246 uint64_t Size = SymSize[Span.Start];
2250 Asm->OutStreamer.EmitIntValue(Size, PtrSize);
2254 Asm->OutStreamer.AddComment("ARange terminator");
2255 Asm->OutStreamer.EmitIntValue(0, PtrSize);
2256 Asm->OutStreamer.EmitIntValue(0, PtrSize);
2260 // Emit visible names into a debug ranges section.
2261 void DwarfDebug::emitDebugRanges() {
2262 // Start the dwarf ranges section.
2263 Asm->OutStreamer.SwitchSection(
2264 Asm->getObjFileLowering().getDwarfRangesSection());
2266 // Size for our labels.
2267 unsigned char Size = Asm->getDataLayout().getPointerSize();
2269 // Grab the specific ranges for the compile units in the module.
2270 for (const auto &I : CUMap) {
2271 DwarfCompileUnit *TheCU = I.second;
2273 // Iterate over the misc ranges for the compile units in the module.
2274 for (const RangeSpanList &List : TheCU->getRangeLists()) {
2275 // Emit our symbol so we can find the beginning of the range.
2276 Asm->OutStreamer.EmitLabel(List.getSym());
2278 for (const RangeSpan &Range : List.getRanges()) {
2279 const MCSymbol *Begin = Range.getStart();
2280 const MCSymbol *End = Range.getEnd();
2281 assert(Begin && "Range without a begin symbol?");
2282 assert(End && "Range without an end symbol?");
2283 if (TheCU->getRanges().size() == 1) {
2284 // Grab the begin symbol from the first range as our base.
2285 const MCSymbol *Base = TheCU->getRanges()[0].getStart();
2286 Asm->EmitLabelDifference(Begin, Base, Size);
2287 Asm->EmitLabelDifference(End, Base, Size);
2289 Asm->OutStreamer.EmitSymbolValue(Begin, Size);
2290 Asm->OutStreamer.EmitSymbolValue(End, Size);
2294 // And terminate the list with two 0 values.
2295 Asm->OutStreamer.EmitIntValue(0, Size);
2296 Asm->OutStreamer.EmitIntValue(0, Size);
2299 // Now emit a range for the CU itself.
2300 if (TheCU->getRanges().size() > 1) {
2301 Asm->OutStreamer.EmitLabel(
2302 Asm->GetTempSymbol("cu_ranges", TheCU->getUniqueID()));
2303 for (const RangeSpan &Range : TheCU->getRanges()) {
2304 const MCSymbol *Begin = Range.getStart();
2305 const MCSymbol *End = Range.getEnd();
2306 assert(Begin && "Range without a begin symbol?");
2307 assert(End && "Range without an end symbol?");
2308 Asm->OutStreamer.EmitSymbolValue(Begin, Size);
2309 Asm->OutStreamer.EmitSymbolValue(End, Size);
2311 // And terminate the list with two 0 values.
2312 Asm->OutStreamer.EmitIntValue(0, Size);
2313 Asm->OutStreamer.EmitIntValue(0, Size);
2318 // DWARF5 Experimental Separate Dwarf emitters.
2320 void DwarfDebug::initSkeletonUnit(const DwarfUnit &U, DIE &Die,
2321 std::unique_ptr<DwarfUnit> NewU) {
2322 NewU->addLocalString(Die, dwarf::DW_AT_GNU_dwo_name,
2323 U.getCUNode().getSplitDebugFilename());
2325 if (!CompilationDir.empty())
2326 NewU->addLocalString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
2328 addGnuPubAttributes(*NewU, Die);
2330 SkeletonHolder.addUnit(std::move(NewU));
2333 // This DIE has the following attributes: DW_AT_comp_dir, DW_AT_stmt_list,
2334 // DW_AT_low_pc, DW_AT_high_pc, DW_AT_ranges, DW_AT_dwo_name, DW_AT_dwo_id,
2335 // DW_AT_addr_base, DW_AT_ranges_base.
2336 DwarfCompileUnit &DwarfDebug::constructSkeletonCU(const DwarfCompileUnit &CU) {
2338 auto OwnedUnit = make_unique<DwarfCompileUnit>(
2339 CU.getUniqueID(), CU.getCUNode(), Asm, this, &SkeletonHolder);
2340 DwarfCompileUnit &NewCU = *OwnedUnit;
2341 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoSection(),
2342 DwarfInfoSectionSym);
2344 NewCU.initStmtList(DwarfLineSectionSym);
2346 initSkeletonUnit(CU, NewCU.getUnitDie(), std::move(OwnedUnit));
2351 // This DIE has the following attributes: DW_AT_comp_dir, DW_AT_dwo_name,
2353 DwarfTypeUnit &DwarfDebug::constructSkeletonTU(DwarfTypeUnit &TU) {
2354 DwarfCompileUnit &CU = static_cast<DwarfCompileUnit &>(
2355 *SkeletonHolder.getUnits()[TU.getCU().getUniqueID()]);
2357 auto OwnedUnit = make_unique<DwarfTypeUnit>(TU.getUniqueID(), CU, Asm, this,
2359 DwarfTypeUnit &NewTU = *OwnedUnit;
2360 NewTU.setTypeSignature(TU.getTypeSignature());
2361 NewTU.setType(nullptr);
2363 Asm->getObjFileLowering().getDwarfTypesSection(TU.getTypeSignature()));
2365 initSkeletonUnit(TU, NewTU.getUnitDie(), std::move(OwnedUnit));
2369 // Emit the .debug_info.dwo section for separated dwarf. This contains the
2370 // compile units that would normally be in debug_info.
2371 void DwarfDebug::emitDebugInfoDWO() {
2372 assert(useSplitDwarf() && "No split dwarf debug info?");
2373 // Don't pass an abbrev symbol, using a constant zero instead so as not to
2374 // emit relocations into the dwo file.
2375 InfoHolder.emitUnits(this, /* AbbrevSymbol */ nullptr);
2378 // Emit the .debug_abbrev.dwo section for separated dwarf. This contains the
2379 // abbreviations for the .debug_info.dwo section.
2380 void DwarfDebug::emitDebugAbbrevDWO() {
2381 assert(useSplitDwarf() && "No split dwarf?");
2382 InfoHolder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevDWOSection());
2385 void DwarfDebug::emitDebugLineDWO() {
2386 assert(useSplitDwarf() && "No split dwarf?");
2387 Asm->OutStreamer.SwitchSection(
2388 Asm->getObjFileLowering().getDwarfLineDWOSection());
2389 SplitTypeUnitFileTable.Emit(Asm->OutStreamer);
2392 // Emit the .debug_str.dwo section for separated dwarf. This contains the
2393 // string section and is identical in format to traditional .debug_str
2395 void DwarfDebug::emitDebugStrDWO() {
2396 assert(useSplitDwarf() && "No split dwarf?");
2397 const MCSection *OffSec =
2398 Asm->getObjFileLowering().getDwarfStrOffDWOSection();
2399 const MCSymbol *StrSym = DwarfStrSectionSym;
2400 InfoHolder.emitStrings(Asm->getObjFileLowering().getDwarfStrDWOSection(),
2404 MCDwarfDwoLineTable *DwarfDebug::getDwoLineTable(const DwarfCompileUnit &CU) {
2405 if (!useSplitDwarf())
2408 SplitTypeUnitFileTable.setCompilationDir(CU.getCUNode().getDirectory());
2409 return &SplitTypeUnitFileTable;
2412 static uint64_t makeTypeSignature(StringRef Identifier) {
2414 Hash.update(Identifier);
2415 // ... take the least significant 8 bytes and return those. Our MD5
2416 // implementation always returns its results in little endian, swap bytes
2418 MD5::MD5Result Result;
2420 return *reinterpret_cast<support::ulittle64_t *>(Result + 8);
2423 void DwarfDebug::addDwarfTypeUnitType(DwarfCompileUnit &CU,
2424 StringRef Identifier, DIE &RefDie,
2425 DICompositeType CTy) {
2426 // Fast path if we're building some type units and one has already used the
2427 // address pool we know we're going to throw away all this work anyway, so
2428 // don't bother building dependent types.
2429 if (!TypeUnitsUnderConstruction.empty() && AddrPool.hasBeenUsed())
2432 const DwarfTypeUnit *&TU = DwarfTypeUnits[CTy];
2434 CU.addDIETypeSignature(RefDie, *TU);
2438 bool TopLevelType = TypeUnitsUnderConstruction.empty();
2439 AddrPool.resetUsedFlag();
2442 make_unique<DwarfTypeUnit>(InfoHolder.getUnits().size(), CU, Asm, this,
2443 &InfoHolder, getDwoLineTable(CU));
2444 DwarfTypeUnit &NewTU = *OwnedUnit;
2445 DIE &UnitDie = NewTU.getUnitDie();
2447 TypeUnitsUnderConstruction.push_back(
2448 std::make_pair(std::move(OwnedUnit), CTy));
2450 NewTU.addUInt(UnitDie, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
2453 uint64_t Signature = makeTypeSignature(Identifier);
2454 NewTU.setTypeSignature(Signature);
2456 if (!useSplitDwarf())
2457 CU.applyStmtList(UnitDie);
2461 ? Asm->getObjFileLowering().getDwarfTypesDWOSection(Signature)
2462 : Asm->getObjFileLowering().getDwarfTypesSection(Signature));
2464 NewTU.setType(NewTU.createTypeDIE(CTy));
2467 auto TypeUnitsToAdd = std::move(TypeUnitsUnderConstruction);
2468 TypeUnitsUnderConstruction.clear();
2470 // Types referencing entries in the address table cannot be placed in type
2472 if (AddrPool.hasBeenUsed()) {
2474 // Remove all the types built while building this type.
2475 // This is pessimistic as some of these types might not be dependent on
2476 // the type that used an address.
2477 for (const auto &TU : TypeUnitsToAdd)
2478 DwarfTypeUnits.erase(TU.second);
2480 // Construct this type in the CU directly.
2481 // This is inefficient because all the dependent types will be rebuilt
2482 // from scratch, including building them in type units, discovering that
2483 // they depend on addresses, throwing them out and rebuilding them.
2484 CU.constructTypeDIE(RefDie, CTy);
2488 // If the type wasn't dependent on fission addresses, finish adding the type
2489 // and all its dependent types.
2490 for (auto &TU : TypeUnitsToAdd) {
2491 if (useSplitDwarf())
2492 TU.first->setSkeleton(constructSkeletonTU(*TU.first));
2493 InfoHolder.addUnit(std::move(TU.first));
2496 CU.addDIETypeSignature(RefDie, NewTU);
2499 void DwarfDebug::attachLowHighPC(DwarfCompileUnit &Unit, DIE &D,
2500 MCSymbol *Begin, MCSymbol *End) {
2501 Unit.addLabelAddress(D, dwarf::DW_AT_low_pc, Begin);
2502 if (DwarfVersion < 4)
2503 Unit.addLabelAddress(D, dwarf::DW_AT_high_pc, End);
2505 Unit.addLabelDelta(D, dwarf::DW_AT_high_pc, End, Begin);
2508 // Accelerator table mutators - add each name along with its companion
2509 // DIE to the proper table while ensuring that the name that we're going
2510 // to reference is in the string table. We do this since the names we
2511 // add may not only be identical to the names in the DIE.
2512 void DwarfDebug::addAccelName(StringRef Name, const DIE &Die) {
2513 if (!useDwarfAccelTables())
2515 AccelNames.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2519 void DwarfDebug::addAccelObjC(StringRef Name, const DIE &Die) {
2520 if (!useDwarfAccelTables())
2522 AccelObjC.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2526 void DwarfDebug::addAccelNamespace(StringRef Name, const DIE &Die) {
2527 if (!useDwarfAccelTables())
2529 AccelNamespace.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2533 void DwarfDebug::addAccelType(StringRef Name, const DIE &Die, char Flags) {
2534 if (!useDwarfAccelTables())
2536 AccelTypes.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),