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 if (!ProcessedSPNodes.insert(Sub))
582 if (DIE *ScopeDIE = TheCU.getDIE(Sub)) {
583 AbstractSPDies.insert(std::make_pair(Sub, ScopeDIE));
584 createAndAddScopeChildren(TheCU, Scope, *ScopeDIE);
588 DIE &DwarfDebug::constructSubprogramScopeDIE(DwarfCompileUnit &TheCU,
589 LexicalScope *Scope) {
590 assert(Scope && Scope->getScopeNode());
591 assert(!Scope->getInlinedAt());
592 assert(!Scope->isAbstractScope());
593 assert(DIScope(Scope->getScopeNode()).isSubprogram());
595 DISubprogram Sub(Scope->getScopeNode());
597 ProcessedSPNodes.insert(Sub);
599 DIE &ScopeDIE = updateSubprogramScopeDIE(TheCU, Sub);
601 createAndAddScopeChildren(TheCU, Scope, ScopeDIE);
606 // Construct a DIE for this scope.
607 std::unique_ptr<DIE> DwarfDebug::constructScopeDIE(DwarfCompileUnit &TheCU,
608 LexicalScope *Scope) {
609 if (!Scope || !Scope->getScopeNode())
612 DIScope DS(Scope->getScopeNode());
614 assert((Scope->getInlinedAt() || !DS.isSubprogram()) &&
615 "Only handle inlined subprograms here, use "
616 "constructSubprogramScopeDIE for non-inlined "
619 SmallVector<std::unique_ptr<DIE>, 8> Children;
621 // We try to create the scope DIE first, then the children DIEs. This will
622 // avoid creating un-used children then removing them later when we find out
623 // the scope DIE is null.
624 std::unique_ptr<DIE> ScopeDIE;
625 if (DS.getContext() && DS.isSubprogram()) {
626 ScopeDIE = constructInlinedScopeDIE(TheCU, Scope);
629 // We create children when the scope DIE is not null.
630 createScopeChildrenDIE(TheCU, Scope, Children);
632 // Early exit when we know the scope DIE is going to be null.
633 if (isLexicalScopeDIENull(Scope))
636 // We create children here when we know the scope DIE is not going to be
637 // null and the children will be added to the scope DIE.
638 createScopeChildrenDIE(TheCU, Scope, Children);
640 // There is no need to emit empty lexical block DIE.
641 std::pair<ImportedEntityMap::const_iterator,
642 ImportedEntityMap::const_iterator> Range =
643 std::equal_range(ScopesWithImportedEntities.begin(),
644 ScopesWithImportedEntities.end(),
645 std::pair<const MDNode *, const MDNode *>(DS, nullptr),
647 if (Children.empty() && Range.first == Range.second)
649 ScopeDIE = constructLexicalScopeDIE(TheCU, Scope);
650 assert(ScopeDIE && "Scope DIE should not be null.");
651 for (ImportedEntityMap::const_iterator i = Range.first; i != Range.second;
653 constructImportedEntityDIE(TheCU, i->second, *ScopeDIE);
657 for (auto &I : Children)
658 ScopeDIE->addChild(std::move(I));
663 void DwarfDebug::addGnuPubAttributes(DwarfUnit &U, DIE &D) const {
664 if (!GenerateGnuPubSections)
667 U.addFlag(D, dwarf::DW_AT_GNU_pubnames);
670 // Create new DwarfCompileUnit for the given metadata node with tag
671 // DW_TAG_compile_unit.
672 DwarfCompileUnit &DwarfDebug::constructDwarfCompileUnit(DICompileUnit DIUnit) {
673 StringRef FN = DIUnit.getFilename();
674 CompilationDir = DIUnit.getDirectory();
676 auto OwnedUnit = make_unique<DwarfCompileUnit>(
677 InfoHolder.getUnits().size(), DIUnit, Asm, this, &InfoHolder);
678 DwarfCompileUnit &NewCU = *OwnedUnit;
679 DIE &Die = NewCU.getUnitDie();
680 InfoHolder.addUnit(std::move(OwnedUnit));
682 // LTO with assembly output shares a single line table amongst multiple CUs.
683 // To avoid the compilation directory being ambiguous, let the line table
684 // explicitly describe the directory of all files, never relying on the
685 // compilation directory.
686 if (!Asm->OutStreamer.hasRawTextSupport() || SingleCU)
687 Asm->OutStreamer.getContext().setMCLineTableCompilationDir(
688 NewCU.getUniqueID(), CompilationDir);
690 NewCU.addString(Die, dwarf::DW_AT_producer, DIUnit.getProducer());
691 NewCU.addUInt(Die, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
692 DIUnit.getLanguage());
693 NewCU.addString(Die, dwarf::DW_AT_name, FN);
695 if (!useSplitDwarf()) {
696 NewCU.initStmtList(DwarfLineSectionSym);
698 // If we're using split dwarf the compilation dir is going to be in the
699 // skeleton CU and so we don't need to duplicate it here.
700 if (!CompilationDir.empty())
701 NewCU.addString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
703 addGnuPubAttributes(NewCU, Die);
706 if (DIUnit.isOptimized())
707 NewCU.addFlag(Die, dwarf::DW_AT_APPLE_optimized);
709 StringRef Flags = DIUnit.getFlags();
711 NewCU.addString(Die, dwarf::DW_AT_APPLE_flags, Flags);
713 if (unsigned RVer = DIUnit.getRunTimeVersion())
714 NewCU.addUInt(Die, dwarf::DW_AT_APPLE_major_runtime_vers,
715 dwarf::DW_FORM_data1, RVer);
720 if (useSplitDwarf()) {
721 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoDWOSection(),
722 DwarfInfoDWOSectionSym);
723 NewCU.setSkeleton(constructSkeletonCU(NewCU));
725 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoSection(),
726 DwarfInfoSectionSym);
728 CUMap.insert(std::make_pair(DIUnit, &NewCU));
729 CUDieMap.insert(std::make_pair(&Die, &NewCU));
733 // Construct subprogram DIE.
734 void DwarfDebug::constructSubprogramDIE(DwarfCompileUnit &TheCU,
736 // FIXME: We should only call this routine once, however, during LTO if a
737 // program is defined in multiple CUs we could end up calling it out of
738 // beginModule as we walk the CUs.
740 DwarfCompileUnit *&CURef = SPMap[N];
746 if (!SP.isDefinition())
747 // This is a method declaration which will be handled while constructing
751 DIE &SubprogramDie = *TheCU.getOrCreateSubprogramDIE(SP);
753 // Expose as a global name.
754 TheCU.addGlobalName(SP.getName(), SubprogramDie, resolve(SP.getContext()));
757 void DwarfDebug::constructImportedEntityDIE(DwarfCompileUnit &TheCU,
759 DIImportedEntity Module(N);
760 assert(Module.Verify());
761 if (DIE *D = TheCU.getOrCreateContextDIE(Module.getContext()))
762 constructImportedEntityDIE(TheCU, Module, *D);
765 void DwarfDebug::constructImportedEntityDIE(DwarfCompileUnit &TheCU,
766 const MDNode *N, DIE &Context) {
767 DIImportedEntity Module(N);
768 assert(Module.Verify());
769 return constructImportedEntityDIE(TheCU, Module, Context);
772 void DwarfDebug::constructImportedEntityDIE(DwarfCompileUnit &TheCU,
773 const DIImportedEntity &Module,
775 assert(Module.Verify() &&
776 "Use one of the MDNode * overloads to handle invalid metadata");
777 DIE &IMDie = TheCU.createAndAddDIE(Module.getTag(), Context, Module);
779 DIDescriptor Entity = resolve(Module.getEntity());
780 if (Entity.isNameSpace())
781 EntityDie = TheCU.getOrCreateNameSpace(DINameSpace(Entity));
782 else if (Entity.isSubprogram())
783 EntityDie = TheCU.getOrCreateSubprogramDIE(DISubprogram(Entity));
784 else if (Entity.isType())
785 EntityDie = TheCU.getOrCreateTypeDIE(DIType(Entity));
787 EntityDie = TheCU.getDIE(Entity);
788 TheCU.addSourceLine(IMDie, Module.getLineNumber(),
789 Module.getContext().getFilename(),
790 Module.getContext().getDirectory());
791 TheCU.addDIEEntry(IMDie, dwarf::DW_AT_import, *EntityDie);
792 StringRef Name = Module.getName();
794 TheCU.addString(IMDie, dwarf::DW_AT_name, Name);
797 // Emit all Dwarf sections that should come prior to the content. Create
798 // global DIEs and emit initial debug info sections. This is invoked by
799 // the target AsmPrinter.
800 void DwarfDebug::beginModule() {
801 if (DisableDebugInfoPrinting)
804 const Module *M = MMI->getModule();
806 // If module has named metadata anchors then use them, otherwise scan the
807 // module using debug info finder to collect debug info.
808 NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
811 TypeIdentifierMap = generateDITypeIdentifierMap(CU_Nodes);
813 // Emit initial sections so we can reference labels later.
816 SingleCU = CU_Nodes->getNumOperands() == 1;
818 for (MDNode *N : CU_Nodes->operands()) {
819 DICompileUnit CUNode(N);
820 DwarfCompileUnit &CU = constructDwarfCompileUnit(CUNode);
821 DIArray ImportedEntities = CUNode.getImportedEntities();
822 for (unsigned i = 0, e = ImportedEntities.getNumElements(); i != e; ++i)
823 ScopesWithImportedEntities.push_back(std::make_pair(
824 DIImportedEntity(ImportedEntities.getElement(i)).getContext(),
825 ImportedEntities.getElement(i)));
826 std::sort(ScopesWithImportedEntities.begin(),
827 ScopesWithImportedEntities.end(), less_first());
828 DIArray GVs = CUNode.getGlobalVariables();
829 for (unsigned i = 0, e = GVs.getNumElements(); i != e; ++i)
830 CU.createGlobalVariableDIE(DIGlobalVariable(GVs.getElement(i)));
831 DIArray SPs = CUNode.getSubprograms();
832 for (unsigned i = 0, e = SPs.getNumElements(); i != e; ++i)
833 constructSubprogramDIE(CU, SPs.getElement(i));
834 DIArray EnumTypes = CUNode.getEnumTypes();
835 for (unsigned i = 0, e = EnumTypes.getNumElements(); i != e; ++i)
836 CU.getOrCreateTypeDIE(EnumTypes.getElement(i));
837 DIArray RetainedTypes = CUNode.getRetainedTypes();
838 for (unsigned i = 0, e = RetainedTypes.getNumElements(); i != e; ++i) {
839 DIType Ty(RetainedTypes.getElement(i));
840 // The retained types array by design contains pointers to
841 // MDNodes rather than DIRefs. Unique them here.
842 DIType UniqueTy(resolve(Ty.getRef()));
843 CU.getOrCreateTypeDIE(UniqueTy);
845 // Emit imported_modules last so that the relevant context is already
847 for (unsigned i = 0, e = ImportedEntities.getNumElements(); i != e; ++i)
848 constructImportedEntityDIE(CU, ImportedEntities.getElement(i));
851 // Tell MMI that we have debug info.
852 MMI->setDebugInfoAvailability(true);
854 // Prime section data.
855 SectionMap[Asm->getObjFileLowering().getTextSection()];
858 // Attach DW_AT_inline attribute with inlined subprogram DIEs.
859 void DwarfDebug::computeInlinedDIEs() {
860 // Attach DW_AT_inline attribute with inlined subprogram DIEs.
861 for (DIE *ISP : InlinedSubprogramDIEs)
862 FirstCU->addUInt(*ISP, dwarf::DW_AT_inline, None, dwarf::DW_INL_inlined);
864 for (const auto &AI : AbstractSPDies) {
865 DIE &ISP = *AI.second;
866 if (InlinedSubprogramDIEs.count(&ISP))
868 FirstCU->addUInt(ISP, dwarf::DW_AT_inline, None, dwarf::DW_INL_inlined);
872 // Collect info for variables that were optimized out.
873 void DwarfDebug::collectDeadVariables() {
874 const Module *M = MMI->getModule();
876 if (NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu")) {
877 for (MDNode *N : CU_Nodes->operands()) {
878 DICompileUnit TheCU(N);
879 DIArray Subprograms = TheCU.getSubprograms();
880 for (unsigned i = 0, e = Subprograms.getNumElements(); i != e; ++i) {
881 DISubprogram SP(Subprograms.getElement(i));
882 if (ProcessedSPNodes.count(SP) != 0)
884 if (!SP.isSubprogram())
886 if (!SP.isDefinition())
888 DIArray Variables = SP.getVariables();
889 if (Variables.getNumElements() == 0)
892 // Construct subprogram DIE and add variables DIEs.
893 DwarfCompileUnit *SPCU =
894 static_cast<DwarfCompileUnit *>(CUMap.lookup(TheCU));
895 assert(SPCU && "Unable to find Compile Unit!");
896 // FIXME: See the comment in constructSubprogramDIE about duplicate
898 constructSubprogramDIE(*SPCU, SP);
899 DIE *SPDIE = SPCU->getDIE(SP);
900 for (unsigned vi = 0, ve = Variables.getNumElements(); vi != ve; ++vi) {
901 DIVariable DV(Variables.getElement(vi));
902 if (!DV.isVariable())
904 DbgVariable NewVar(DV, nullptr, this);
905 SPDIE->addChild(SPCU->constructVariableDIE(NewVar));
912 void DwarfDebug::finalizeModuleInfo() {
913 // Collect info for variables that were optimized out.
914 collectDeadVariables();
916 // Attach DW_AT_inline attribute with inlined subprogram DIEs.
917 computeInlinedDIEs();
919 // Handle anything that needs to be done on a per-unit basis after
920 // all other generation.
921 for (const auto &TheU : getUnits()) {
922 // Emit DW_AT_containing_type attribute to connect types with their
923 // vtable holding type.
924 TheU->constructContainingTypeDIEs();
926 // Add CU specific attributes if we need to add any.
927 if (TheU->getUnitDie().getTag() == dwarf::DW_TAG_compile_unit) {
928 // If we're splitting the dwarf out now that we've got the entire
929 // CU then add the dwo id to it.
930 DwarfCompileUnit *SkCU =
931 static_cast<DwarfCompileUnit *>(TheU->getSkeleton());
932 if (useSplitDwarf()) {
933 // Emit a unique identifier for this CU.
934 uint64_t ID = DIEHash(Asm).computeCUSignature(TheU->getUnitDie());
935 TheU->addUInt(TheU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
936 dwarf::DW_FORM_data8, ID);
937 SkCU->addUInt(SkCU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
938 dwarf::DW_FORM_data8, ID);
940 // We don't keep track of which addresses are used in which CU so this
941 // is a bit pessimistic under LTO.
942 if (!AddrPool.isEmpty())
943 addSectionLabel(*Asm, *SkCU, SkCU->getUnitDie(),
944 dwarf::DW_AT_GNU_addr_base, DwarfAddrSectionSym,
945 DwarfAddrSectionSym);
946 if (!TheU->getRangeLists().empty())
947 addSectionLabel(*Asm, *SkCU, SkCU->getUnitDie(),
948 dwarf::DW_AT_GNU_ranges_base,
949 DwarfDebugRangeSectionSym, DwarfDebugRangeSectionSym);
952 // If we have code split among multiple sections or non-contiguous
953 // ranges of code then emit a DW_AT_ranges attribute on the unit that will
954 // remain in the .o file, otherwise add a DW_AT_low_pc.
955 // FIXME: We should use ranges allow reordering of code ala
956 // .subsections_via_symbols in mach-o. This would mean turning on
957 // ranges for all subprogram DIEs for mach-o.
958 DwarfCompileUnit &U =
959 SkCU ? *SkCU : static_cast<DwarfCompileUnit &>(*TheU);
960 unsigned NumRanges = TheU->getRanges().size();
963 addSectionLabel(*Asm, U, U.getUnitDie(), dwarf::DW_AT_ranges,
964 Asm->GetTempSymbol("cu_ranges", U.getUniqueID()),
965 DwarfDebugRangeSectionSym);
967 // A DW_AT_low_pc attribute may also be specified in combination with
968 // DW_AT_ranges to specify the default base address for use in
969 // location lists (see Section 2.6.2) and range lists (see Section
971 U.addUInt(U.getUnitDie(), dwarf::DW_AT_low_pc, dwarf::DW_FORM_addr,
974 RangeSpan &Range = TheU->getRanges().back();
975 U.addLocalLabelAddress(U.getUnitDie(), dwarf::DW_AT_low_pc,
977 U.addLabelDelta(U.getUnitDie(), dwarf::DW_AT_high_pc, Range.getEnd(),
984 // Compute DIE offsets and sizes.
985 InfoHolder.computeSizeAndOffsets();
987 SkeletonHolder.computeSizeAndOffsets();
990 void DwarfDebug::endSections() {
991 // Filter labels by section.
992 for (const SymbolCU &SCU : ArangeLabels) {
993 if (SCU.Sym->isInSection()) {
994 // Make a note of this symbol and it's section.
995 const MCSection *Section = &SCU.Sym->getSection();
996 if (!Section->getKind().isMetadata())
997 SectionMap[Section].push_back(SCU);
999 // Some symbols (e.g. common/bss on mach-o) can have no section but still
1000 // appear in the output. This sucks as we rely on sections to build
1001 // arange spans. We can do it without, but it's icky.
1002 SectionMap[nullptr].push_back(SCU);
1006 // Build a list of sections used.
1007 std::vector<const MCSection *> Sections;
1008 for (const auto &it : SectionMap) {
1009 const MCSection *Section = it.first;
1010 Sections.push_back(Section);
1013 // Sort the sections into order.
1014 // This is only done to ensure consistent output order across different runs.
1015 std::sort(Sections.begin(), Sections.end(), SectionSort);
1017 // Add terminating symbols for each section.
1018 for (unsigned ID = 0, E = Sections.size(); ID != E; ID++) {
1019 const MCSection *Section = Sections[ID];
1020 MCSymbol *Sym = nullptr;
1023 // We can't call MCSection::getLabelEndName, as it's only safe to do so
1024 // if we know the section name up-front. For user-created sections, the
1025 // resulting label may not be valid to use as a label. (section names can
1026 // use a greater set of characters on some systems)
1027 Sym = Asm->GetTempSymbol("debug_end", ID);
1028 Asm->OutStreamer.SwitchSection(Section);
1029 Asm->OutStreamer.EmitLabel(Sym);
1032 // Insert a final terminator.
1033 SectionMap[Section].push_back(SymbolCU(nullptr, Sym));
1037 // Emit all Dwarf sections that should come after the content.
1038 void DwarfDebug::endModule() {
1039 assert(CurFn == nullptr);
1040 assert(CurMI == nullptr);
1045 // End any existing sections.
1046 // TODO: Does this need to happen?
1049 // Finalize the debug info for the module.
1050 finalizeModuleInfo();
1054 // Emit all the DIEs into a debug info section.
1057 // Corresponding abbreviations into a abbrev section.
1058 emitAbbreviations();
1060 // Emit info into a debug aranges section.
1061 if (GenerateARangeSection)
1064 // Emit info into a debug ranges section.
1067 if (useSplitDwarf()) {
1070 emitDebugAbbrevDWO();
1072 // Emit DWO addresses.
1073 AddrPool.emit(*Asm, Asm->getObjFileLowering().getDwarfAddrSection());
1076 // Emit info into a debug loc section.
1079 // Emit info into the dwarf accelerator table sections.
1080 if (useDwarfAccelTables()) {
1083 emitAccelNamespaces();
1087 // Emit the pubnames and pubtypes sections if requested.
1088 if (HasDwarfPubSections) {
1089 emitDebugPubNames(GenerateGnuPubSections);
1090 emitDebugPubTypes(GenerateGnuPubSections);
1096 // Reset these for the next Module if we have one.
1100 // Find abstract variable, if any, associated with Var.
1101 DbgVariable *DwarfDebug::findAbstractVariable(DIVariable &DV,
1102 DebugLoc ScopeLoc) {
1103 LLVMContext &Ctx = DV->getContext();
1104 // More then one inlined variable corresponds to one abstract variable.
1105 DIVariable Var = cleanseInlinedVariable(DV, Ctx);
1106 DbgVariable *AbsDbgVariable = AbstractVariables.lookup(Var);
1108 return AbsDbgVariable;
1110 LexicalScope *Scope = LScopes.findAbstractScope(ScopeLoc.getScope(Ctx));
1114 AbsDbgVariable = new DbgVariable(Var, nullptr, this);
1115 addScopeVariable(Scope, AbsDbgVariable);
1116 AbstractVariables[Var] = AbsDbgVariable;
1117 return AbsDbgVariable;
1120 // If Var is a current function argument then add it to CurrentFnArguments list.
1121 bool DwarfDebug::addCurrentFnArgument(DbgVariable *Var, LexicalScope *Scope) {
1122 if (!LScopes.isCurrentFunctionScope(Scope))
1124 DIVariable DV = Var->getVariable();
1125 if (DV.getTag() != dwarf::DW_TAG_arg_variable)
1127 unsigned ArgNo = DV.getArgNumber();
1131 size_t Size = CurrentFnArguments.size();
1133 CurrentFnArguments.resize(CurFn->getFunction()->arg_size());
1134 // llvm::Function argument size is not good indicator of how many
1135 // arguments does the function have at source level.
1137 CurrentFnArguments.resize(ArgNo * 2);
1138 CurrentFnArguments[ArgNo - 1] = Var;
1142 // Collect variable information from side table maintained by MMI.
1143 void DwarfDebug::collectVariableInfoFromMMITable(
1144 SmallPtrSet<const MDNode *, 16> &Processed) {
1145 for (const auto &VI : MMI->getVariableDbgInfo()) {
1148 Processed.insert(VI.Var);
1149 DIVariable DV(VI.Var);
1150 LexicalScope *Scope = LScopes.findLexicalScope(VI.Loc);
1152 // If variable scope is not found then skip this variable.
1156 DbgVariable *AbsDbgVariable = findAbstractVariable(DV, VI.Loc);
1157 DbgVariable *RegVar = new DbgVariable(DV, AbsDbgVariable, this);
1158 RegVar->setFrameIndex(VI.Slot);
1159 if (!addCurrentFnArgument(RegVar, Scope))
1160 addScopeVariable(Scope, RegVar);
1162 AbsDbgVariable->setFrameIndex(VI.Slot);
1166 // Get .debug_loc entry for the instruction range starting at MI.
1167 static DebugLocEntry::Value getDebugLocValue(const MachineInstr *MI) {
1168 const MDNode *Var = MI->getDebugVariable();
1170 assert(MI->getNumOperands() == 3);
1171 if (MI->getOperand(0).isReg()) {
1172 MachineLocation MLoc;
1173 // If the second operand is an immediate, this is a
1174 // register-indirect address.
1175 if (!MI->getOperand(1).isImm())
1176 MLoc.set(MI->getOperand(0).getReg());
1178 MLoc.set(MI->getOperand(0).getReg(), MI->getOperand(1).getImm());
1179 return DebugLocEntry::Value(Var, MLoc);
1181 if (MI->getOperand(0).isImm())
1182 return DebugLocEntry::Value(Var, MI->getOperand(0).getImm());
1183 if (MI->getOperand(0).isFPImm())
1184 return DebugLocEntry::Value(Var, MI->getOperand(0).getFPImm());
1185 if (MI->getOperand(0).isCImm())
1186 return DebugLocEntry::Value(Var, MI->getOperand(0).getCImm());
1188 llvm_unreachable("Unexpected 3 operand DBG_VALUE instruction!");
1191 // Find variables for each lexical scope.
1193 DwarfDebug::collectVariableInfo(SmallPtrSet<const MDNode *, 16> &Processed) {
1194 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1195 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1197 // Grab the variable info that was squirreled away in the MMI side-table.
1198 collectVariableInfoFromMMITable(Processed);
1200 for (const auto &I : DbgValues) {
1201 DIVariable DV(I.first);
1202 if (Processed.count(DV))
1205 // History contains relevant DBG_VALUE instructions for DV and instructions
1207 const SmallVectorImpl<const MachineInstr *> &History = I.second;
1208 if (History.empty())
1210 const MachineInstr *MInsn = History.front();
1212 LexicalScope *Scope = nullptr;
1213 if (DV.getTag() == dwarf::DW_TAG_arg_variable &&
1214 DISubprogram(DV.getContext()).describes(CurFn->getFunction()))
1215 Scope = LScopes.getCurrentFunctionScope();
1216 else if (MDNode *IA = DV.getInlinedAt()) {
1217 DebugLoc DL = DebugLoc::getFromDILocation(IA);
1218 Scope = LScopes.findInlinedScope(DebugLoc::get(
1219 DL.getLine(), DL.getCol(), DV.getContext(), IA));
1221 Scope = LScopes.findLexicalScope(DV.getContext());
1222 // If variable scope is not found then skip this variable.
1226 Processed.insert(DV);
1227 assert(MInsn->isDebugValue() && "History must begin with debug value");
1228 DbgVariable *AbsVar = findAbstractVariable(DV, MInsn->getDebugLoc());
1229 DbgVariable *RegVar = new DbgVariable(DV, AbsVar, this);
1230 if (!addCurrentFnArgument(RegVar, Scope))
1231 addScopeVariable(Scope, RegVar);
1233 AbsVar->setMInsn(MInsn);
1235 // Simplify ranges that are fully coalesced.
1236 if (History.size() <= 1 ||
1237 (History.size() == 2 && MInsn->isIdenticalTo(History.back()))) {
1238 RegVar->setMInsn(MInsn);
1242 // Handle multiple DBG_VALUE instructions describing one variable.
1243 RegVar->setDotDebugLocOffset(DotDebugLocEntries.size());
1245 DotDebugLocEntries.resize(DotDebugLocEntries.size() + 1);
1246 DebugLocList &LocList = DotDebugLocEntries.back();
1248 Asm->GetTempSymbol("debug_loc", DotDebugLocEntries.size() - 1);
1249 SmallVector<DebugLocEntry, 4> &DebugLoc = LocList.List;
1250 for (SmallVectorImpl<const MachineInstr *>::const_iterator
1251 HI = History.begin(),
1254 const MachineInstr *Begin = *HI;
1255 assert(Begin->isDebugValue() && "Invalid History entry");
1257 // Check if DBG_VALUE is truncating a range.
1258 if (Begin->getNumOperands() > 1 && Begin->getOperand(0).isReg() &&
1259 !Begin->getOperand(0).getReg())
1262 // Compute the range for a register location.
1263 const MCSymbol *FLabel = getLabelBeforeInsn(Begin);
1264 const MCSymbol *SLabel = nullptr;
1267 // If Begin is the last instruction in History then its value is valid
1268 // until the end of the function.
1269 SLabel = FunctionEndSym;
1271 const MachineInstr *End = HI[1];
1272 DEBUG(dbgs() << "DotDebugLoc Pair:\n"
1273 << "\t" << *Begin << "\t" << *End << "\n");
1274 if (End->isDebugValue())
1275 SLabel = getLabelBeforeInsn(End);
1277 // End is a normal instruction clobbering the range.
1278 SLabel = getLabelAfterInsn(End);
1279 assert(SLabel && "Forgot label after clobber instruction");
1284 // The value is valid until the next DBG_VALUE or clobber.
1285 DebugLocEntry Loc(FLabel, SLabel, getDebugLocValue(Begin), TheCU);
1286 if (DebugLoc.empty() || !DebugLoc.back().Merge(Loc))
1287 DebugLoc.push_back(std::move(Loc));
1291 // Collect info for variables that were optimized out.
1292 DIArray Variables = DISubprogram(FnScope->getScopeNode()).getVariables();
1293 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1294 DIVariable DV(Variables.getElement(i));
1295 if (!DV || !DV.isVariable() || !Processed.insert(DV))
1297 if (LexicalScope *Scope = LScopes.findLexicalScope(DV.getContext()))
1298 addScopeVariable(Scope, new DbgVariable(DV, nullptr, this));
1302 // Return Label preceding the instruction.
1303 MCSymbol *DwarfDebug::getLabelBeforeInsn(const MachineInstr *MI) {
1304 MCSymbol *Label = LabelsBeforeInsn.lookup(MI);
1305 assert(Label && "Didn't insert label before instruction");
1309 // Return Label immediately following the instruction.
1310 MCSymbol *DwarfDebug::getLabelAfterInsn(const MachineInstr *MI) {
1311 return LabelsAfterInsn.lookup(MI);
1314 // Process beginning of an instruction.
1315 void DwarfDebug::beginInstruction(const MachineInstr *MI) {
1316 assert(CurMI == nullptr);
1318 // Check if source location changes, but ignore DBG_VALUE locations.
1319 if (!MI->isDebugValue()) {
1320 DebugLoc DL = MI->getDebugLoc();
1321 if (DL != PrevInstLoc && (!DL.isUnknown() || UnknownLocations)) {
1324 if (DL == PrologEndLoc) {
1325 Flags |= DWARF2_FLAG_PROLOGUE_END;
1326 PrologEndLoc = DebugLoc();
1328 if (PrologEndLoc.isUnknown())
1329 Flags |= DWARF2_FLAG_IS_STMT;
1331 if (!DL.isUnknown()) {
1332 const MDNode *Scope = DL.getScope(Asm->MF->getFunction()->getContext());
1333 recordSourceLine(DL.getLine(), DL.getCol(), Scope, Flags);
1335 recordSourceLine(0, 0, nullptr, 0);
1339 // Insert labels where requested.
1340 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1341 LabelsBeforeInsn.find(MI);
1344 if (I == LabelsBeforeInsn.end())
1347 // Label already assigned.
1352 PrevLabel = MMI->getContext().CreateTempSymbol();
1353 Asm->OutStreamer.EmitLabel(PrevLabel);
1355 I->second = PrevLabel;
1358 // Process end of an instruction.
1359 void DwarfDebug::endInstruction() {
1360 assert(CurMI != nullptr);
1361 // Don't create a new label after DBG_VALUE instructions.
1362 // They don't generate code.
1363 if (!CurMI->isDebugValue())
1364 PrevLabel = nullptr;
1366 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1367 LabelsAfterInsn.find(CurMI);
1371 if (I == LabelsAfterInsn.end())
1374 // Label already assigned.
1378 // We need a label after this instruction.
1380 PrevLabel = MMI->getContext().CreateTempSymbol();
1381 Asm->OutStreamer.EmitLabel(PrevLabel);
1383 I->second = PrevLabel;
1386 // Each LexicalScope has first instruction and last instruction to mark
1387 // beginning and end of a scope respectively. Create an inverse map that list
1388 // scopes starts (and ends) with an instruction. One instruction may start (or
1389 // end) multiple scopes. Ignore scopes that are not reachable.
1390 void DwarfDebug::identifyScopeMarkers() {
1391 SmallVector<LexicalScope *, 4> WorkList;
1392 WorkList.push_back(LScopes.getCurrentFunctionScope());
1393 while (!WorkList.empty()) {
1394 LexicalScope *S = WorkList.pop_back_val();
1396 const SmallVectorImpl<LexicalScope *> &Children = S->getChildren();
1397 if (!Children.empty())
1398 WorkList.append(Children.begin(), Children.end());
1400 if (S->isAbstractScope())
1403 for (const InsnRange &R : S->getRanges()) {
1404 assert(R.first && "InsnRange does not have first instruction!");
1405 assert(R.second && "InsnRange does not have second instruction!");
1406 requestLabelBeforeInsn(R.first);
1407 requestLabelAfterInsn(R.second);
1412 // Gather pre-function debug information. Assumes being called immediately
1413 // after the function entry point has been emitted.
1414 void DwarfDebug::beginFunction(const MachineFunction *MF) {
1417 // If there's no debug info for the function we're not going to do anything.
1418 if (!MMI->hasDebugInfo())
1421 // Grab the lexical scopes for the function, if we don't have any of those
1422 // then we're not going to be able to do anything.
1423 LScopes.initialize(*MF);
1424 if (LScopes.empty())
1427 assert(DbgValues.empty() && "DbgValues map wasn't cleaned!");
1429 // Make sure that each lexical scope will have a begin/end label.
1430 identifyScopeMarkers();
1432 // Set DwarfDwarfCompileUnitID in MCContext to the Compile Unit this function
1433 // belongs to so that we add to the correct per-cu line table in the
1435 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1436 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1437 assert(TheCU && "Unable to find compile unit!");
1438 if (Asm->OutStreamer.hasRawTextSupport())
1439 // Use a single line table if we are generating assembly.
1440 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1442 Asm->OutStreamer.getContext().setDwarfCompileUnitID(TheCU->getUniqueID());
1444 // Emit a label for the function so that we have a beginning address.
1445 FunctionBeginSym = Asm->GetTempSymbol("func_begin", Asm->getFunctionNumber());
1446 // Assumes in correct section after the entry point.
1447 Asm->OutStreamer.EmitLabel(FunctionBeginSym);
1449 // Collect user variables, find the end of the prologue.
1450 for (const auto &MBB : *MF) {
1451 for (const auto &MI : MBB) {
1452 if (MI.isDebugValue()) {
1453 assert(MI.getNumOperands() > 1 && "Invalid machine instruction!");
1454 // Keep track of user variables in order of appearance. Create the
1455 // empty history for each variable so that the order of keys in
1456 // DbgValues is correct. Actual history will be populated in
1457 // calculateDbgValueHistory() function.
1458 const MDNode *Var = MI.getDebugVariable();
1460 std::make_pair(Var, SmallVector<const MachineInstr *, 4>()));
1461 } else if (!MI.getFlag(MachineInstr::FrameSetup) &&
1462 PrologEndLoc.isUnknown() && !MI.getDebugLoc().isUnknown()) {
1463 // First known non-DBG_VALUE and non-frame setup location marks
1464 // the beginning of the function body.
1465 PrologEndLoc = MI.getDebugLoc();
1470 // Calculate history for local variables.
1471 calculateDbgValueHistory(MF, Asm->TM.getRegisterInfo(), DbgValues);
1473 // Request labels for the full history.
1474 for (auto &I : DbgValues) {
1475 const SmallVectorImpl<const MachineInstr *> &History = I.second;
1476 if (History.empty())
1479 // The first mention of a function argument gets the FunctionBeginSym
1480 // label, so arguments are visible when breaking at function entry.
1481 DIVariable DV(I.first);
1482 if (DV.isVariable() && DV.getTag() == dwarf::DW_TAG_arg_variable &&
1483 getDISubprogram(DV.getContext()).describes(MF->getFunction()))
1484 LabelsBeforeInsn[History.front()] = FunctionBeginSym;
1486 for (const MachineInstr *MI : History) {
1487 if (MI->isDebugValue())
1488 requestLabelBeforeInsn(MI);
1490 requestLabelAfterInsn(MI);
1494 PrevInstLoc = DebugLoc();
1495 PrevLabel = FunctionBeginSym;
1497 // Record beginning of function.
1498 if (!PrologEndLoc.isUnknown()) {
1499 DebugLoc FnStartDL =
1500 PrologEndLoc.getFnDebugLoc(MF->getFunction()->getContext());
1502 FnStartDL.getLine(), FnStartDL.getCol(),
1503 FnStartDL.getScope(MF->getFunction()->getContext()),
1504 // We'd like to list the prologue as "not statements" but GDB behaves
1505 // poorly if we do that. Revisit this with caution/GDB (7.5+) testing.
1506 DWARF2_FLAG_IS_STMT);
1510 void DwarfDebug::addScopeVariable(LexicalScope *LS, DbgVariable *Var) {
1511 SmallVectorImpl<DbgVariable *> &Vars = ScopeVariables[LS];
1512 DIVariable DV = Var->getVariable();
1513 // Variables with positive arg numbers are parameters.
1514 if (unsigned ArgNum = DV.getArgNumber()) {
1515 // Keep all parameters in order at the start of the variable list to ensure
1516 // function types are correct (no out-of-order parameters)
1518 // This could be improved by only doing it for optimized builds (unoptimized
1519 // builds have the right order to begin with), searching from the back (this
1520 // would catch the unoptimized case quickly), or doing a binary search
1521 // rather than linear search.
1522 SmallVectorImpl<DbgVariable *>::iterator I = Vars.begin();
1523 while (I != Vars.end()) {
1524 unsigned CurNum = (*I)->getVariable().getArgNumber();
1525 // A local (non-parameter) variable has been found, insert immediately
1529 // A later indexed parameter has been found, insert immediately before it.
1530 if (CurNum > ArgNum)
1534 Vars.insert(I, Var);
1538 Vars.push_back(Var);
1541 // Gather and emit post-function debug information.
1542 void DwarfDebug::endFunction(const MachineFunction *MF) {
1543 // Every beginFunction(MF) call should be followed by an endFunction(MF) call,
1544 // though the beginFunction may not be called at all.
1545 // We should handle both cases.
1549 assert(CurFn == MF);
1550 assert(CurFn != nullptr);
1552 if (!MMI->hasDebugInfo() || LScopes.empty()) {
1553 // If we don't have a lexical scope for this function then there will
1554 // be a hole in the range information. Keep note of this by setting the
1555 // previously used section to nullptr.
1556 PrevSection = nullptr;
1562 // Define end label for subprogram.
1563 FunctionEndSym = Asm->GetTempSymbol("func_end", Asm->getFunctionNumber());
1564 // Assumes in correct section after the entry point.
1565 Asm->OutStreamer.EmitLabel(FunctionEndSym);
1567 // Set DwarfDwarfCompileUnitID in MCContext to default value.
1568 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1570 SmallPtrSet<const MDNode *, 16> ProcessedVars;
1571 collectVariableInfo(ProcessedVars);
1573 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1574 DwarfCompileUnit &TheCU = *SPMap.lookup(FnScope->getScopeNode());
1576 // Construct abstract scopes.
1577 for (LexicalScope *AScope : LScopes.getAbstractScopesList()) {
1578 DISubprogram SP(AScope->getScopeNode());
1579 if (!SP.isSubprogram())
1581 // Collect info for variables that were optimized out.
1582 DIArray Variables = SP.getVariables();
1583 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1584 DIVariable DV(Variables.getElement(i));
1585 assert(DV && DV.isVariable());
1586 if (!ProcessedVars.insert(DV))
1588 // Check that DbgVariable for DV wasn't created earlier, when
1589 // findAbstractVariable() was called for inlined instance of DV.
1590 LLVMContext &Ctx = DV->getContext();
1591 DIVariable CleanDV = cleanseInlinedVariable(DV, Ctx);
1592 if (AbstractVariables.lookup(CleanDV))
1594 if (LexicalScope *Scope = LScopes.findAbstractScope(DV.getContext()))
1595 addScopeVariable(Scope, new DbgVariable(DV, nullptr, this));
1597 constructAbstractSubprogramScopeDIE(TheCU, AScope);
1600 DIE &CurFnDIE = constructSubprogramScopeDIE(TheCU, FnScope);
1601 if (!CurFn->getTarget().Options.DisableFramePointerElim(*CurFn))
1602 TheCU.addFlag(CurFnDIE, dwarf::DW_AT_APPLE_omit_frame_ptr);
1604 // Add the range of this function to the list of ranges for the CU.
1605 RangeSpan Span(FunctionBeginSym, FunctionEndSym);
1606 TheCU.addRange(std::move(Span));
1607 PrevSection = Asm->getCurrentSection();
1611 for (auto &I : ScopeVariables)
1612 DeleteContainerPointers(I.second);
1613 ScopeVariables.clear();
1614 DeleteContainerPointers(CurrentFnArguments);
1616 AbstractVariables.clear();
1617 LabelsBeforeInsn.clear();
1618 LabelsAfterInsn.clear();
1619 PrevLabel = nullptr;
1623 // Register a source line with debug info. Returns the unique label that was
1624 // emitted and which provides correspondence to the source line list.
1625 void DwarfDebug::recordSourceLine(unsigned Line, unsigned Col, const MDNode *S,
1630 unsigned Discriminator = 0;
1632 DIDescriptor Scope(S);
1634 if (Scope.isCompileUnit()) {
1635 DICompileUnit CU(S);
1636 Fn = CU.getFilename();
1637 Dir = CU.getDirectory();
1638 } else if (Scope.isFile()) {
1640 Fn = F.getFilename();
1641 Dir = F.getDirectory();
1642 } else if (Scope.isSubprogram()) {
1644 Fn = SP.getFilename();
1645 Dir = SP.getDirectory();
1646 } else if (Scope.isLexicalBlockFile()) {
1647 DILexicalBlockFile DBF(S);
1648 Fn = DBF.getFilename();
1649 Dir = DBF.getDirectory();
1650 } else if (Scope.isLexicalBlock()) {
1651 DILexicalBlock DB(S);
1652 Fn = DB.getFilename();
1653 Dir = DB.getDirectory();
1654 Discriminator = DB.getDiscriminator();
1656 llvm_unreachable("Unexpected scope info");
1658 unsigned CUID = Asm->OutStreamer.getContext().getDwarfCompileUnitID();
1659 Src = static_cast<DwarfCompileUnit &>(*InfoHolder.getUnits()[CUID])
1660 .getOrCreateSourceID(Fn, Dir);
1662 Asm->OutStreamer.EmitDwarfLocDirective(Src, Line, Col, Flags, 0,
1666 //===----------------------------------------------------------------------===//
1668 //===----------------------------------------------------------------------===//
1670 // Emit initial Dwarf sections with a label at the start of each one.
1671 void DwarfDebug::emitSectionLabels() {
1672 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
1674 // Dwarf sections base addresses.
1675 DwarfInfoSectionSym =
1676 emitSectionSym(Asm, TLOF.getDwarfInfoSection(), "section_info");
1677 if (useSplitDwarf())
1678 DwarfInfoDWOSectionSym =
1679 emitSectionSym(Asm, TLOF.getDwarfInfoDWOSection(), "section_info_dwo");
1680 DwarfAbbrevSectionSym =
1681 emitSectionSym(Asm, TLOF.getDwarfAbbrevSection(), "section_abbrev");
1682 if (useSplitDwarf())
1683 DwarfAbbrevDWOSectionSym = emitSectionSym(
1684 Asm, TLOF.getDwarfAbbrevDWOSection(), "section_abbrev_dwo");
1685 if (GenerateARangeSection)
1686 emitSectionSym(Asm, TLOF.getDwarfARangesSection());
1688 DwarfLineSectionSym =
1689 emitSectionSym(Asm, TLOF.getDwarfLineSection(), "section_line");
1690 if (GenerateGnuPubSections) {
1691 DwarfGnuPubNamesSectionSym =
1692 emitSectionSym(Asm, TLOF.getDwarfGnuPubNamesSection());
1693 DwarfGnuPubTypesSectionSym =
1694 emitSectionSym(Asm, TLOF.getDwarfGnuPubTypesSection());
1695 } else if (HasDwarfPubSections) {
1696 emitSectionSym(Asm, TLOF.getDwarfPubNamesSection());
1697 emitSectionSym(Asm, TLOF.getDwarfPubTypesSection());
1700 DwarfStrSectionSym =
1701 emitSectionSym(Asm, TLOF.getDwarfStrSection(), "info_string");
1702 if (useSplitDwarf()) {
1703 DwarfStrDWOSectionSym =
1704 emitSectionSym(Asm, TLOF.getDwarfStrDWOSection(), "skel_string");
1705 DwarfAddrSectionSym =
1706 emitSectionSym(Asm, TLOF.getDwarfAddrSection(), "addr_sec");
1707 DwarfDebugLocSectionSym =
1708 emitSectionSym(Asm, TLOF.getDwarfLocDWOSection(), "skel_loc");
1710 DwarfDebugLocSectionSym =
1711 emitSectionSym(Asm, TLOF.getDwarfLocSection(), "section_debug_loc");
1712 DwarfDebugRangeSectionSym =
1713 emitSectionSym(Asm, TLOF.getDwarfRangesSection(), "debug_range");
1716 // Recursively emits a debug information entry.
1717 void DwarfDebug::emitDIE(DIE &Die) {
1718 // Get the abbreviation for this DIE.
1719 const DIEAbbrev &Abbrev = Die.getAbbrev();
1721 // Emit the code (index) for the abbreviation.
1722 if (Asm->isVerbose())
1723 Asm->OutStreamer.AddComment("Abbrev [" + Twine(Abbrev.getNumber()) +
1724 "] 0x" + Twine::utohexstr(Die.getOffset()) +
1725 ":0x" + Twine::utohexstr(Die.getSize()) + " " +
1726 dwarf::TagString(Abbrev.getTag()));
1727 Asm->EmitULEB128(Abbrev.getNumber());
1729 const SmallVectorImpl<DIEValue *> &Values = Die.getValues();
1730 const SmallVectorImpl<DIEAbbrevData> &AbbrevData = Abbrev.getData();
1732 // Emit the DIE attribute values.
1733 for (unsigned i = 0, N = Values.size(); i < N; ++i) {
1734 dwarf::Attribute Attr = AbbrevData[i].getAttribute();
1735 dwarf::Form Form = AbbrevData[i].getForm();
1736 assert(Form && "Too many attributes for DIE (check abbreviation)");
1738 if (Asm->isVerbose()) {
1739 Asm->OutStreamer.AddComment(dwarf::AttributeString(Attr));
1740 if (Attr == dwarf::DW_AT_accessibility)
1741 Asm->OutStreamer.AddComment(dwarf::AccessibilityString(
1742 cast<DIEInteger>(Values[i])->getValue()));
1745 // Emit an attribute using the defined form.
1746 Values[i]->EmitValue(Asm, Form);
1749 // Emit the DIE children if any.
1750 if (Abbrev.hasChildren()) {
1751 for (auto &Child : Die.getChildren())
1754 Asm->OutStreamer.AddComment("End Of Children Mark");
1759 // Emit the debug info section.
1760 void DwarfDebug::emitDebugInfo() {
1761 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1763 Holder.emitUnits(this, DwarfAbbrevSectionSym);
1766 // Emit the abbreviation section.
1767 void DwarfDebug::emitAbbreviations() {
1768 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1770 Holder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevSection());
1773 // Emit the last address of the section and the end of the line matrix.
1774 void DwarfDebug::emitEndOfLineMatrix(unsigned SectionEnd) {
1775 // Define last address of section.
1776 Asm->OutStreamer.AddComment("Extended Op");
1779 Asm->OutStreamer.AddComment("Op size");
1780 Asm->EmitInt8(Asm->getDataLayout().getPointerSize() + 1);
1781 Asm->OutStreamer.AddComment("DW_LNE_set_address");
1782 Asm->EmitInt8(dwarf::DW_LNE_set_address);
1784 Asm->OutStreamer.AddComment("Section end label");
1786 Asm->OutStreamer.EmitSymbolValue(
1787 Asm->GetTempSymbol("section_end", SectionEnd),
1788 Asm->getDataLayout().getPointerSize());
1790 // Mark end of matrix.
1791 Asm->OutStreamer.AddComment("DW_LNE_end_sequence");
1797 // Emit visible names into a hashed accelerator table section.
1798 void DwarfDebug::emitAccelNames() {
1799 AccelNames.FinalizeTable(Asm, "Names");
1800 Asm->OutStreamer.SwitchSection(
1801 Asm->getObjFileLowering().getDwarfAccelNamesSection());
1802 MCSymbol *SectionBegin = Asm->GetTempSymbol("names_begin");
1803 Asm->OutStreamer.EmitLabel(SectionBegin);
1805 // Emit the full data.
1806 AccelNames.Emit(Asm, SectionBegin, &InfoHolder);
1809 // Emit objective C classes and categories into a hashed accelerator table
1811 void DwarfDebug::emitAccelObjC() {
1812 AccelObjC.FinalizeTable(Asm, "ObjC");
1813 Asm->OutStreamer.SwitchSection(
1814 Asm->getObjFileLowering().getDwarfAccelObjCSection());
1815 MCSymbol *SectionBegin = Asm->GetTempSymbol("objc_begin");
1816 Asm->OutStreamer.EmitLabel(SectionBegin);
1818 // Emit the full data.
1819 AccelObjC.Emit(Asm, SectionBegin, &InfoHolder);
1822 // Emit namespace dies into a hashed accelerator table.
1823 void DwarfDebug::emitAccelNamespaces() {
1824 AccelNamespace.FinalizeTable(Asm, "namespac");
1825 Asm->OutStreamer.SwitchSection(
1826 Asm->getObjFileLowering().getDwarfAccelNamespaceSection());
1827 MCSymbol *SectionBegin = Asm->GetTempSymbol("namespac_begin");
1828 Asm->OutStreamer.EmitLabel(SectionBegin);
1830 // Emit the full data.
1831 AccelNamespace.Emit(Asm, SectionBegin, &InfoHolder);
1834 // Emit type dies into a hashed accelerator table.
1835 void DwarfDebug::emitAccelTypes() {
1837 AccelTypes.FinalizeTable(Asm, "types");
1838 Asm->OutStreamer.SwitchSection(
1839 Asm->getObjFileLowering().getDwarfAccelTypesSection());
1840 MCSymbol *SectionBegin = Asm->GetTempSymbol("types_begin");
1841 Asm->OutStreamer.EmitLabel(SectionBegin);
1843 // Emit the full data.
1844 AccelTypes.Emit(Asm, SectionBegin, &InfoHolder);
1847 // Public name handling.
1848 // The format for the various pubnames:
1850 // dwarf pubnames - offset/name pairs where the offset is the offset into the CU
1851 // for the DIE that is named.
1853 // gnu pubnames - offset/index value/name tuples where the offset is the offset
1854 // into the CU and the index value is computed according to the type of value
1855 // for the DIE that is named.
1857 // For type units the offset is the offset of the skeleton DIE. For split dwarf
1858 // it's the offset within the debug_info/debug_types dwo section, however, the
1859 // reference in the pubname header doesn't change.
1861 /// computeIndexValue - Compute the gdb index value for the DIE and CU.
1862 static dwarf::PubIndexEntryDescriptor computeIndexValue(DwarfUnit *CU,
1864 dwarf::GDBIndexEntryLinkage Linkage = dwarf::GIEL_STATIC;
1866 // We could have a specification DIE that has our most of our knowledge,
1867 // look for that now.
1868 DIEValue *SpecVal = Die->findAttribute(dwarf::DW_AT_specification);
1870 DIE &SpecDIE = cast<DIEEntry>(SpecVal)->getEntry();
1871 if (SpecDIE.findAttribute(dwarf::DW_AT_external))
1872 Linkage = dwarf::GIEL_EXTERNAL;
1873 } else if (Die->findAttribute(dwarf::DW_AT_external))
1874 Linkage = dwarf::GIEL_EXTERNAL;
1876 switch (Die->getTag()) {
1877 case dwarf::DW_TAG_class_type:
1878 case dwarf::DW_TAG_structure_type:
1879 case dwarf::DW_TAG_union_type:
1880 case dwarf::DW_TAG_enumeration_type:
1881 return dwarf::PubIndexEntryDescriptor(
1882 dwarf::GIEK_TYPE, CU->getLanguage() != dwarf::DW_LANG_C_plus_plus
1883 ? dwarf::GIEL_STATIC
1884 : dwarf::GIEL_EXTERNAL);
1885 case dwarf::DW_TAG_typedef:
1886 case dwarf::DW_TAG_base_type:
1887 case dwarf::DW_TAG_subrange_type:
1888 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_TYPE, dwarf::GIEL_STATIC);
1889 case dwarf::DW_TAG_namespace:
1890 return dwarf::GIEK_TYPE;
1891 case dwarf::DW_TAG_subprogram:
1892 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_FUNCTION, Linkage);
1893 case dwarf::DW_TAG_constant:
1894 case dwarf::DW_TAG_variable:
1895 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE, Linkage);
1896 case dwarf::DW_TAG_enumerator:
1897 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE,
1898 dwarf::GIEL_STATIC);
1900 return dwarf::GIEK_NONE;
1904 /// emitDebugPubNames - Emit visible names into a debug pubnames section.
1906 void DwarfDebug::emitDebugPubNames(bool GnuStyle) {
1907 const MCSection *PSec =
1908 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubNamesSection()
1909 : Asm->getObjFileLowering().getDwarfPubNamesSection();
1911 emitDebugPubSection(GnuStyle, PSec, "Names", &DwarfUnit::getGlobalNames);
1914 void DwarfDebug::emitDebugPubSection(
1915 bool GnuStyle, const MCSection *PSec, StringRef Name,
1916 const StringMap<const DIE *> &(DwarfUnit::*Accessor)() const) {
1917 for (const auto &NU : CUMap) {
1918 DwarfCompileUnit *TheU = NU.second;
1920 const auto &Globals = (TheU->*Accessor)();
1922 if (Globals.empty())
1925 if (auto Skeleton = static_cast<DwarfCompileUnit *>(TheU->getSkeleton()))
1927 unsigned ID = TheU->getUniqueID();
1929 // Start the dwarf pubnames section.
1930 Asm->OutStreamer.SwitchSection(PSec);
1933 Asm->OutStreamer.AddComment("Length of Public " + Name + " Info");
1934 MCSymbol *BeginLabel = Asm->GetTempSymbol("pub" + Name + "_begin", ID);
1935 MCSymbol *EndLabel = Asm->GetTempSymbol("pub" + Name + "_end", ID);
1936 Asm->EmitLabelDifference(EndLabel, BeginLabel, 4);
1938 Asm->OutStreamer.EmitLabel(BeginLabel);
1940 Asm->OutStreamer.AddComment("DWARF Version");
1941 Asm->EmitInt16(dwarf::DW_PUBNAMES_VERSION);
1943 Asm->OutStreamer.AddComment("Offset of Compilation Unit Info");
1944 Asm->EmitSectionOffset(TheU->getLabelBegin(), TheU->getSectionSym());
1946 Asm->OutStreamer.AddComment("Compilation Unit Length");
1947 Asm->EmitLabelDifference(TheU->getLabelEnd(), TheU->getLabelBegin(), 4);
1949 // Emit the pubnames for this compilation unit.
1950 for (const auto &GI : Globals) {
1951 const char *Name = GI.getKeyData();
1952 const DIE *Entity = GI.second;
1954 Asm->OutStreamer.AddComment("DIE offset");
1955 Asm->EmitInt32(Entity->getOffset());
1958 dwarf::PubIndexEntryDescriptor Desc = computeIndexValue(TheU, Entity);
1959 Asm->OutStreamer.AddComment(
1960 Twine("Kind: ") + dwarf::GDBIndexEntryKindString(Desc.Kind) + ", " +
1961 dwarf::GDBIndexEntryLinkageString(Desc.Linkage));
1962 Asm->EmitInt8(Desc.toBits());
1965 Asm->OutStreamer.AddComment("External Name");
1966 Asm->OutStreamer.EmitBytes(StringRef(Name, GI.getKeyLength() + 1));
1969 Asm->OutStreamer.AddComment("End Mark");
1971 Asm->OutStreamer.EmitLabel(EndLabel);
1975 void DwarfDebug::emitDebugPubTypes(bool GnuStyle) {
1976 const MCSection *PSec =
1977 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubTypesSection()
1978 : Asm->getObjFileLowering().getDwarfPubTypesSection();
1980 emitDebugPubSection(GnuStyle, PSec, "Types", &DwarfUnit::getGlobalTypes);
1983 // Emit visible names into a debug str section.
1984 void DwarfDebug::emitDebugStr() {
1985 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1986 Holder.emitStrings(Asm->getObjFileLowering().getDwarfStrSection());
1989 void DwarfDebug::emitDebugLocEntry(ByteStreamer &Streamer,
1990 const DebugLocEntry &Entry) {
1991 assert(Entry.getValues().size() == 1 &&
1992 "multi-value entries are not supported yet.");
1993 const DebugLocEntry::Value Value = Entry.getValues()[0];
1994 DIVariable DV(Value.getVariable());
1995 if (Value.isInt()) {
1996 DIBasicType BTy(resolve(DV.getType()));
1997 if (BTy.Verify() && (BTy.getEncoding() == dwarf::DW_ATE_signed ||
1998 BTy.getEncoding() == dwarf::DW_ATE_signed_char)) {
1999 Streamer.EmitInt8(dwarf::DW_OP_consts, "DW_OP_consts");
2000 Streamer.EmitSLEB128(Value.getInt());
2002 Streamer.EmitInt8(dwarf::DW_OP_constu, "DW_OP_constu");
2003 Streamer.EmitULEB128(Value.getInt());
2005 } else if (Value.isLocation()) {
2006 MachineLocation Loc = Value.getLoc();
2007 if (!DV.hasComplexAddress())
2009 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2011 // Complex address entry.
2012 unsigned N = DV.getNumAddrElements();
2014 if (N >= 2 && DV.getAddrElement(0) == DIBuilder::OpPlus) {
2015 if (Loc.getOffset()) {
2017 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2018 Streamer.EmitInt8(dwarf::DW_OP_deref, "DW_OP_deref");
2019 Streamer.EmitInt8(dwarf::DW_OP_plus_uconst, "DW_OP_plus_uconst");
2020 Streamer.EmitSLEB128(DV.getAddrElement(1));
2022 // If first address element is OpPlus then emit
2023 // DW_OP_breg + Offset instead of DW_OP_reg + Offset.
2024 MachineLocation TLoc(Loc.getReg(), DV.getAddrElement(1));
2025 Asm->EmitDwarfRegOp(Streamer, TLoc, DV.isIndirect());
2029 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2032 // Emit remaining complex address elements.
2033 for (; i < N; ++i) {
2034 uint64_t Element = DV.getAddrElement(i);
2035 if (Element == DIBuilder::OpPlus) {
2036 Streamer.EmitInt8(dwarf::DW_OP_plus_uconst, "DW_OP_plus_uconst");
2037 Streamer.EmitULEB128(DV.getAddrElement(++i));
2038 } else if (Element == DIBuilder::OpDeref) {
2040 Streamer.EmitInt8(dwarf::DW_OP_deref, "DW_OP_deref");
2042 llvm_unreachable("unknown Opcode found in complex address");
2046 // else ... ignore constant fp. There is not any good way to
2047 // to represent them here in dwarf.
2051 void DwarfDebug::emitDebugLocEntryLocation(const DebugLocEntry &Entry) {
2052 Asm->OutStreamer.AddComment("Loc expr size");
2053 MCSymbol *begin = Asm->OutStreamer.getContext().CreateTempSymbol();
2054 MCSymbol *end = Asm->OutStreamer.getContext().CreateTempSymbol();
2055 Asm->EmitLabelDifference(end, begin, 2);
2056 Asm->OutStreamer.EmitLabel(begin);
2058 APByteStreamer Streamer(*Asm);
2059 emitDebugLocEntry(Streamer, Entry);
2061 Asm->OutStreamer.EmitLabel(end);
2064 // Emit locations into the debug loc section.
2065 void DwarfDebug::emitDebugLoc() {
2066 // Start the dwarf loc section.
2067 Asm->OutStreamer.SwitchSection(
2068 Asm->getObjFileLowering().getDwarfLocSection());
2069 unsigned char Size = Asm->getDataLayout().getPointerSize();
2070 for (const auto &DebugLoc : DotDebugLocEntries) {
2071 Asm->OutStreamer.EmitLabel(DebugLoc.Label);
2072 for (const auto &Entry : DebugLoc.List) {
2073 // Set up the range. This range is relative to the entry point of the
2074 // compile unit. This is a hard coded 0 for low_pc when we're emitting
2075 // ranges, or the DW_AT_low_pc on the compile unit otherwise.
2076 const DwarfCompileUnit *CU = Entry.getCU();
2077 if (CU->getRanges().size() == 1) {
2078 // Grab the begin symbol from the first range as our base.
2079 const MCSymbol *Base = CU->getRanges()[0].getStart();
2080 Asm->EmitLabelDifference(Entry.getBeginSym(), Base, Size);
2081 Asm->EmitLabelDifference(Entry.getEndSym(), Base, Size);
2083 Asm->OutStreamer.EmitSymbolValue(Entry.getBeginSym(), Size);
2084 Asm->OutStreamer.EmitSymbolValue(Entry.getEndSym(), Size);
2087 emitDebugLocEntryLocation(Entry);
2089 Asm->OutStreamer.EmitIntValue(0, Size);
2090 Asm->OutStreamer.EmitIntValue(0, Size);
2094 void DwarfDebug::emitDebugLocDWO() {
2095 Asm->OutStreamer.SwitchSection(
2096 Asm->getObjFileLowering().getDwarfLocDWOSection());
2097 for (const auto &DebugLoc : DotDebugLocEntries) {
2098 Asm->OutStreamer.EmitLabel(DebugLoc.Label);
2099 for (const auto &Entry : DebugLoc.List) {
2100 // Just always use start_length for now - at least that's one address
2101 // rather than two. We could get fancier and try to, say, reuse an
2102 // address we know we've emitted elsewhere (the start of the function?
2103 // The start of the CU or CU subrange that encloses this range?)
2104 Asm->EmitInt8(dwarf::DW_LLE_start_length_entry);
2105 unsigned idx = AddrPool.getIndex(Entry.getBeginSym());
2106 Asm->EmitULEB128(idx);
2107 Asm->EmitLabelDifference(Entry.getEndSym(), Entry.getBeginSym(), 4);
2109 emitDebugLocEntryLocation(Entry);
2111 Asm->EmitInt8(dwarf::DW_LLE_end_of_list_entry);
2116 const MCSymbol *Start, *End;
2119 // Emit a debug aranges section, containing a CU lookup for any
2120 // address we can tie back to a CU.
2121 void DwarfDebug::emitDebugARanges() {
2122 // Start the dwarf aranges section.
2123 Asm->OutStreamer.SwitchSection(
2124 Asm->getObjFileLowering().getDwarfARangesSection());
2126 typedef DenseMap<DwarfCompileUnit *, std::vector<ArangeSpan>> SpansType;
2130 // Build a list of sections used.
2131 std::vector<const MCSection *> Sections;
2132 for (const auto &it : SectionMap) {
2133 const MCSection *Section = it.first;
2134 Sections.push_back(Section);
2137 // Sort the sections into order.
2138 // This is only done to ensure consistent output order across different runs.
2139 std::sort(Sections.begin(), Sections.end(), SectionSort);
2141 // Build a set of address spans, sorted by CU.
2142 for (const MCSection *Section : Sections) {
2143 SmallVector<SymbolCU, 8> &List = SectionMap[Section];
2144 if (List.size() < 2)
2147 // Sort the symbols by offset within the section.
2148 std::sort(List.begin(), List.end(),
2149 [&](const SymbolCU &A, const SymbolCU &B) {
2150 unsigned IA = A.Sym ? Asm->OutStreamer.GetSymbolOrder(A.Sym) : 0;
2151 unsigned IB = B.Sym ? Asm->OutStreamer.GetSymbolOrder(B.Sym) : 0;
2153 // Symbols with no order assigned should be placed at the end.
2154 // (e.g. section end labels)
2162 // If we have no section (e.g. common), just write out
2163 // individual spans for each symbol.
2165 for (const SymbolCU &Cur : List) {
2167 Span.Start = Cur.Sym;
2170 Spans[Cur.CU].push_back(Span);
2173 // Build spans between each label.
2174 const MCSymbol *StartSym = List[0].Sym;
2175 for (size_t n = 1, e = List.size(); n < e; n++) {
2176 const SymbolCU &Prev = List[n - 1];
2177 const SymbolCU &Cur = List[n];
2179 // Try and build the longest span we can within the same CU.
2180 if (Cur.CU != Prev.CU) {
2182 Span.Start = StartSym;
2184 Spans[Prev.CU].push_back(Span);
2191 unsigned PtrSize = Asm->getDataLayout().getPointerSize();
2193 // Build a list of CUs used.
2194 std::vector<DwarfCompileUnit *> CUs;
2195 for (const auto &it : Spans) {
2196 DwarfCompileUnit *CU = it.first;
2200 // Sort the CU list (again, to ensure consistent output order).
2201 std::sort(CUs.begin(), CUs.end(), [](const DwarfUnit *A, const DwarfUnit *B) {
2202 return A->getUniqueID() < B->getUniqueID();
2205 // Emit an arange table for each CU we used.
2206 for (DwarfCompileUnit *CU : CUs) {
2207 std::vector<ArangeSpan> &List = Spans[CU];
2209 // Emit size of content not including length itself.
2210 unsigned ContentSize =
2211 sizeof(int16_t) + // DWARF ARange version number
2212 sizeof(int32_t) + // Offset of CU in the .debug_info section
2213 sizeof(int8_t) + // Pointer Size (in bytes)
2214 sizeof(int8_t); // Segment Size (in bytes)
2216 unsigned TupleSize = PtrSize * 2;
2218 // 7.20 in the Dwarf specs requires the table to be aligned to a tuple.
2220 OffsetToAlignment(sizeof(int32_t) + ContentSize, TupleSize);
2222 ContentSize += Padding;
2223 ContentSize += (List.size() + 1) * TupleSize;
2225 // For each compile unit, write the list of spans it covers.
2226 Asm->OutStreamer.AddComment("Length of ARange Set");
2227 Asm->EmitInt32(ContentSize);
2228 Asm->OutStreamer.AddComment("DWARF Arange version number");
2229 Asm->EmitInt16(dwarf::DW_ARANGES_VERSION);
2230 Asm->OutStreamer.AddComment("Offset Into Debug Info Section");
2231 Asm->EmitSectionOffset(CU->getLocalLabelBegin(), CU->getLocalSectionSym());
2232 Asm->OutStreamer.AddComment("Address Size (in bytes)");
2233 Asm->EmitInt8(PtrSize);
2234 Asm->OutStreamer.AddComment("Segment Size (in bytes)");
2237 Asm->OutStreamer.EmitFill(Padding, 0xff);
2239 for (const ArangeSpan &Span : List) {
2240 Asm->EmitLabelReference(Span.Start, PtrSize);
2242 // Calculate the size as being from the span start to it's end.
2244 Asm->EmitLabelDifference(Span.End, Span.Start, PtrSize);
2246 // For symbols without an end marker (e.g. common), we
2247 // write a single arange entry containing just that one symbol.
2248 uint64_t Size = SymSize[Span.Start];
2252 Asm->OutStreamer.EmitIntValue(Size, PtrSize);
2256 Asm->OutStreamer.AddComment("ARange terminator");
2257 Asm->OutStreamer.EmitIntValue(0, PtrSize);
2258 Asm->OutStreamer.EmitIntValue(0, PtrSize);
2262 // Emit visible names into a debug ranges section.
2263 void DwarfDebug::emitDebugRanges() {
2264 // Start the dwarf ranges section.
2265 Asm->OutStreamer.SwitchSection(
2266 Asm->getObjFileLowering().getDwarfRangesSection());
2268 // Size for our labels.
2269 unsigned char Size = Asm->getDataLayout().getPointerSize();
2271 // Grab the specific ranges for the compile units in the module.
2272 for (const auto &I : CUMap) {
2273 DwarfCompileUnit *TheCU = I.second;
2275 // Iterate over the misc ranges for the compile units in the module.
2276 for (const RangeSpanList &List : TheCU->getRangeLists()) {
2277 // Emit our symbol so we can find the beginning of the range.
2278 Asm->OutStreamer.EmitLabel(List.getSym());
2280 for (const RangeSpan &Range : List.getRanges()) {
2281 const MCSymbol *Begin = Range.getStart();
2282 const MCSymbol *End = Range.getEnd();
2283 assert(Begin && "Range without a begin symbol?");
2284 assert(End && "Range without an end symbol?");
2285 if (TheCU->getRanges().size() == 1) {
2286 // Grab the begin symbol from the first range as our base.
2287 const MCSymbol *Base = TheCU->getRanges()[0].getStart();
2288 Asm->EmitLabelDifference(Begin, Base, Size);
2289 Asm->EmitLabelDifference(End, Base, Size);
2291 Asm->OutStreamer.EmitSymbolValue(Begin, Size);
2292 Asm->OutStreamer.EmitSymbolValue(End, Size);
2296 // And terminate the list with two 0 values.
2297 Asm->OutStreamer.EmitIntValue(0, Size);
2298 Asm->OutStreamer.EmitIntValue(0, Size);
2301 // Now emit a range for the CU itself.
2302 if (TheCU->getRanges().size() > 1) {
2303 Asm->OutStreamer.EmitLabel(
2304 Asm->GetTempSymbol("cu_ranges", TheCU->getUniqueID()));
2305 for (const RangeSpan &Range : TheCU->getRanges()) {
2306 const MCSymbol *Begin = Range.getStart();
2307 const MCSymbol *End = Range.getEnd();
2308 assert(Begin && "Range without a begin symbol?");
2309 assert(End && "Range without an end symbol?");
2310 Asm->OutStreamer.EmitSymbolValue(Begin, Size);
2311 Asm->OutStreamer.EmitSymbolValue(End, Size);
2313 // And terminate the list with two 0 values.
2314 Asm->OutStreamer.EmitIntValue(0, Size);
2315 Asm->OutStreamer.EmitIntValue(0, Size);
2320 // DWARF5 Experimental Separate Dwarf emitters.
2322 void DwarfDebug::initSkeletonUnit(const DwarfUnit &U, DIE &Die,
2323 std::unique_ptr<DwarfUnit> NewU) {
2324 NewU->addLocalString(Die, dwarf::DW_AT_GNU_dwo_name,
2325 U.getCUNode().getSplitDebugFilename());
2327 if (!CompilationDir.empty())
2328 NewU->addLocalString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
2330 addGnuPubAttributes(*NewU, Die);
2332 SkeletonHolder.addUnit(std::move(NewU));
2335 // This DIE has the following attributes: DW_AT_comp_dir, DW_AT_stmt_list,
2336 // DW_AT_low_pc, DW_AT_high_pc, DW_AT_ranges, DW_AT_dwo_name, DW_AT_dwo_id,
2337 // DW_AT_addr_base, DW_AT_ranges_base.
2338 DwarfCompileUnit &DwarfDebug::constructSkeletonCU(const DwarfCompileUnit &CU) {
2340 auto OwnedUnit = make_unique<DwarfCompileUnit>(
2341 CU.getUniqueID(), CU.getCUNode(), Asm, this, &SkeletonHolder);
2342 DwarfCompileUnit &NewCU = *OwnedUnit;
2343 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoSection(),
2344 DwarfInfoSectionSym);
2346 NewCU.initStmtList(DwarfLineSectionSym);
2348 initSkeletonUnit(CU, NewCU.getUnitDie(), std::move(OwnedUnit));
2353 // This DIE has the following attributes: DW_AT_comp_dir, DW_AT_dwo_name,
2355 DwarfTypeUnit &DwarfDebug::constructSkeletonTU(DwarfTypeUnit &TU) {
2356 DwarfCompileUnit &CU = static_cast<DwarfCompileUnit &>(
2357 *SkeletonHolder.getUnits()[TU.getCU().getUniqueID()]);
2359 auto OwnedUnit = make_unique<DwarfTypeUnit>(TU.getUniqueID(), CU, Asm, this,
2361 DwarfTypeUnit &NewTU = *OwnedUnit;
2362 NewTU.setTypeSignature(TU.getTypeSignature());
2363 NewTU.setType(nullptr);
2365 Asm->getObjFileLowering().getDwarfTypesSection(TU.getTypeSignature()));
2367 initSkeletonUnit(TU, NewTU.getUnitDie(), std::move(OwnedUnit));
2371 // Emit the .debug_info.dwo section for separated dwarf. This contains the
2372 // compile units that would normally be in debug_info.
2373 void DwarfDebug::emitDebugInfoDWO() {
2374 assert(useSplitDwarf() && "No split dwarf debug info?");
2375 // Don't pass an abbrev symbol, using a constant zero instead so as not to
2376 // emit relocations into the dwo file.
2377 InfoHolder.emitUnits(this, /* AbbrevSymbol */ nullptr);
2380 // Emit the .debug_abbrev.dwo section for separated dwarf. This contains the
2381 // abbreviations for the .debug_info.dwo section.
2382 void DwarfDebug::emitDebugAbbrevDWO() {
2383 assert(useSplitDwarf() && "No split dwarf?");
2384 InfoHolder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevDWOSection());
2387 void DwarfDebug::emitDebugLineDWO() {
2388 assert(useSplitDwarf() && "No split dwarf?");
2389 Asm->OutStreamer.SwitchSection(
2390 Asm->getObjFileLowering().getDwarfLineDWOSection());
2391 SplitTypeUnitFileTable.Emit(Asm->OutStreamer);
2394 // Emit the .debug_str.dwo section for separated dwarf. This contains the
2395 // string section and is identical in format to traditional .debug_str
2397 void DwarfDebug::emitDebugStrDWO() {
2398 assert(useSplitDwarf() && "No split dwarf?");
2399 const MCSection *OffSec =
2400 Asm->getObjFileLowering().getDwarfStrOffDWOSection();
2401 const MCSymbol *StrSym = DwarfStrSectionSym;
2402 InfoHolder.emitStrings(Asm->getObjFileLowering().getDwarfStrDWOSection(),
2406 MCDwarfDwoLineTable *DwarfDebug::getDwoLineTable(const DwarfCompileUnit &CU) {
2407 if (!useSplitDwarf())
2410 SplitTypeUnitFileTable.setCompilationDir(CU.getCUNode().getDirectory());
2411 return &SplitTypeUnitFileTable;
2414 static uint64_t makeTypeSignature(StringRef Identifier) {
2416 Hash.update(Identifier);
2417 // ... take the least significant 8 bytes and return those. Our MD5
2418 // implementation always returns its results in little endian, swap bytes
2420 MD5::MD5Result Result;
2422 return *reinterpret_cast<support::ulittle64_t *>(Result + 8);
2425 void DwarfDebug::addDwarfTypeUnitType(DwarfCompileUnit &CU,
2426 StringRef Identifier, DIE &RefDie,
2427 DICompositeType CTy) {
2428 // Fast path if we're building some type units and one has already used the
2429 // address pool we know we're going to throw away all this work anyway, so
2430 // don't bother building dependent types.
2431 if (!TypeUnitsUnderConstruction.empty() && AddrPool.hasBeenUsed())
2434 const DwarfTypeUnit *&TU = DwarfTypeUnits[CTy];
2436 CU.addDIETypeSignature(RefDie, *TU);
2440 bool TopLevelType = TypeUnitsUnderConstruction.empty();
2441 AddrPool.resetUsedFlag();
2444 make_unique<DwarfTypeUnit>(InfoHolder.getUnits().size(), CU, Asm, this,
2445 &InfoHolder, getDwoLineTable(CU));
2446 DwarfTypeUnit &NewTU = *OwnedUnit;
2447 DIE &UnitDie = NewTU.getUnitDie();
2449 TypeUnitsUnderConstruction.push_back(
2450 std::make_pair(std::move(OwnedUnit), CTy));
2452 NewTU.addUInt(UnitDie, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
2455 uint64_t Signature = makeTypeSignature(Identifier);
2456 NewTU.setTypeSignature(Signature);
2458 if (!useSplitDwarf())
2459 CU.applyStmtList(UnitDie);
2463 ? Asm->getObjFileLowering().getDwarfTypesDWOSection(Signature)
2464 : Asm->getObjFileLowering().getDwarfTypesSection(Signature));
2466 NewTU.setType(NewTU.createTypeDIE(CTy));
2469 auto TypeUnitsToAdd = std::move(TypeUnitsUnderConstruction);
2470 TypeUnitsUnderConstruction.clear();
2472 // Types referencing entries in the address table cannot be placed in type
2474 if (AddrPool.hasBeenUsed()) {
2476 // Remove all the types built while building this type.
2477 // This is pessimistic as some of these types might not be dependent on
2478 // the type that used an address.
2479 for (const auto &TU : TypeUnitsToAdd)
2480 DwarfTypeUnits.erase(TU.second);
2482 // Construct this type in the CU directly.
2483 // This is inefficient because all the dependent types will be rebuilt
2484 // from scratch, including building them in type units, discovering that
2485 // they depend on addresses, throwing them out and rebuilding them.
2486 CU.constructTypeDIE(RefDie, CTy);
2490 // If the type wasn't dependent on fission addresses, finish adding the type
2491 // and all its dependent types.
2492 for (auto &TU : TypeUnitsToAdd) {
2493 if (useSplitDwarf())
2494 TU.first->setSkeleton(constructSkeletonTU(*TU.first));
2495 InfoHolder.addUnit(std::move(TU.first));
2498 CU.addDIETypeSignature(RefDie, NewTU);
2501 void DwarfDebug::attachLowHighPC(DwarfCompileUnit &Unit, DIE &D,
2502 MCSymbol *Begin, MCSymbol *End) {
2503 Unit.addLabelAddress(D, dwarf::DW_AT_low_pc, Begin);
2504 if (DwarfVersion < 4)
2505 Unit.addLabelAddress(D, dwarf::DW_AT_high_pc, End);
2507 Unit.addLabelDelta(D, dwarf::DW_AT_high_pc, End, Begin);
2510 // Accelerator table mutators - add each name along with its companion
2511 // DIE to the proper table while ensuring that the name that we're going
2512 // to reference is in the string table. We do this since the names we
2513 // add may not only be identical to the names in the DIE.
2514 void DwarfDebug::addAccelName(StringRef Name, const DIE &Die) {
2515 if (!useDwarfAccelTables())
2517 AccelNames.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2521 void DwarfDebug::addAccelObjC(StringRef Name, const DIE &Die) {
2522 if (!useDwarfAccelTables())
2524 AccelObjC.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2528 void DwarfDebug::addAccelNamespace(StringRef Name, const DIE &Die) {
2529 if (!useDwarfAccelTables())
2531 AccelNamespace.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2535 void DwarfDebug::addAccelType(StringRef Name, const DIE &Die, char Flags) {
2536 if (!useDwarfAccelTables())
2538 AccelTypes.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),