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());
122 DIType DbgVariable::getType() const {
123 DIType Ty = Var.getType().resolve(DD->getTypeIdentifierMap());
124 // FIXME: isBlockByrefVariable should be reformulated in terms of complex
125 // addresses instead.
126 if (Var.isBlockByrefVariable(DD->getTypeIdentifierMap())) {
127 /* Byref variables, in Blocks, are declared by the programmer as
128 "SomeType VarName;", but the compiler creates a
129 __Block_byref_x_VarName struct, and gives the variable VarName
130 either the struct, or a pointer to the struct, as its type. This
131 is necessary for various behind-the-scenes things the compiler
132 needs to do with by-reference variables in blocks.
134 However, as far as the original *programmer* is concerned, the
135 variable should still have type 'SomeType', as originally declared.
137 The following function dives into the __Block_byref_x_VarName
138 struct to find the original type of the variable. This will be
139 passed back to the code generating the type for the Debug
140 Information Entry for the variable 'VarName'. 'VarName' will then
141 have the original type 'SomeType' in its debug information.
143 The original type 'SomeType' will be the type of the field named
144 'VarName' inside the __Block_byref_x_VarName struct.
146 NOTE: In order for this to not completely fail on the debugger
147 side, the Debug Information Entry for the variable VarName needs to
148 have a DW_AT_location that tells the debugger how to unwind through
149 the pointers and __Block_byref_x_VarName struct to find the actual
150 value of the variable. The function addBlockByrefType does this. */
152 uint16_t tag = Ty.getTag();
154 if (tag == dwarf::DW_TAG_pointer_type)
155 subType = resolve(DIDerivedType(Ty).getTypeDerivedFrom());
157 DIArray Elements = DICompositeType(subType).getTypeArray();
158 for (unsigned i = 0, N = Elements.getNumElements(); i < N; ++i) {
159 DIDerivedType DT(Elements.getElement(i));
160 if (getName() == DT.getName())
161 return (resolve(DT.getTypeDerivedFrom()));
167 static LLVM_CONSTEXPR DwarfAccelTable::Atom TypeAtoms[] = {
168 DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset, dwarf::DW_FORM_data4),
169 DwarfAccelTable::Atom(dwarf::DW_ATOM_die_tag, dwarf::DW_FORM_data2),
170 DwarfAccelTable::Atom(dwarf::DW_ATOM_type_flags, dwarf::DW_FORM_data1)};
172 DwarfDebug::DwarfDebug(AsmPrinter *A, Module *M)
173 : Asm(A), MMI(Asm->MMI), FirstCU(nullptr), PrevLabel(nullptr),
174 GlobalRangeCount(0), InfoHolder(A, "info_string", DIEValueAllocator),
175 UsedNonDefaultText(false),
176 SkeletonHolder(A, "skel_string", DIEValueAllocator),
177 AccelNames(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
178 dwarf::DW_FORM_data4)),
179 AccelObjC(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
180 dwarf::DW_FORM_data4)),
181 AccelNamespace(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
182 dwarf::DW_FORM_data4)),
183 AccelTypes(TypeAtoms) {
185 DwarfInfoSectionSym = DwarfAbbrevSectionSym = DwarfStrSectionSym = nullptr;
186 DwarfDebugRangeSectionSym = DwarfDebugLocSectionSym = nullptr;
187 DwarfLineSectionSym = nullptr;
188 DwarfAddrSectionSym = nullptr;
189 DwarfAbbrevDWOSectionSym = DwarfStrDWOSectionSym = nullptr;
190 FunctionBeginSym = FunctionEndSym = nullptr;
194 // Turn on accelerator tables for Darwin by default, pubnames by
195 // default for non-Darwin, and handle split dwarf.
196 bool IsDarwin = Triple(A->getTargetTriple()).isOSDarwin();
198 if (DwarfAccelTables == Default)
199 HasDwarfAccelTables = IsDarwin;
201 HasDwarfAccelTables = DwarfAccelTables == Enable;
203 if (SplitDwarf == Default)
204 HasSplitDwarf = false;
206 HasSplitDwarf = SplitDwarf == Enable;
208 if (DwarfPubSections == Default)
209 HasDwarfPubSections = !IsDarwin;
211 HasDwarfPubSections = DwarfPubSections == Enable;
213 DwarfVersion = DwarfVersionNumber
215 : MMI->getModule()->getDwarfVersion();
218 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
223 // Switch to the specified MCSection and emit an assembler
224 // temporary label to it if SymbolStem is specified.
225 static MCSymbol *emitSectionSym(AsmPrinter *Asm, const MCSection *Section,
226 const char *SymbolStem = nullptr) {
227 Asm->OutStreamer.SwitchSection(Section);
231 MCSymbol *TmpSym = Asm->GetTempSymbol(SymbolStem);
232 Asm->OutStreamer.EmitLabel(TmpSym);
236 static bool isObjCClass(StringRef Name) {
237 return Name.startswith("+") || Name.startswith("-");
240 static bool hasObjCCategory(StringRef Name) {
241 if (!isObjCClass(Name))
244 return Name.find(") ") != StringRef::npos;
247 static void getObjCClassCategory(StringRef In, StringRef &Class,
248 StringRef &Category) {
249 if (!hasObjCCategory(In)) {
250 Class = In.slice(In.find('[') + 1, In.find(' '));
255 Class = In.slice(In.find('[') + 1, In.find('('));
256 Category = In.slice(In.find('[') + 1, In.find(' '));
260 static StringRef getObjCMethodName(StringRef In) {
261 return In.slice(In.find(' ') + 1, In.find(']'));
264 // Helper for sorting sections into a stable output order.
265 static bool SectionSort(const MCSection *A, const MCSection *B) {
266 std::string LA = (A ? A->getLabelBeginName() : "");
267 std::string LB = (B ? B->getLabelBeginName() : "");
271 // Add the various names to the Dwarf accelerator table names.
272 // TODO: Determine whether or not we should add names for programs
273 // that do not have a DW_AT_name or DW_AT_linkage_name field - this
274 // is only slightly different than the lookup of non-standard ObjC names.
275 void DwarfDebug::addSubprogramNames(DISubprogram SP, DIE &Die) {
276 if (!SP.isDefinition())
278 addAccelName(SP.getName(), Die);
280 // If the linkage name is different than the name, go ahead and output
281 // that as well into the name table.
282 if (SP.getLinkageName() != "" && SP.getName() != SP.getLinkageName())
283 addAccelName(SP.getLinkageName(), Die);
285 // If this is an Objective-C selector name add it to the ObjC accelerator
287 if (isObjCClass(SP.getName())) {
288 StringRef Class, Category;
289 getObjCClassCategory(SP.getName(), Class, Category);
290 addAccelObjC(Class, Die);
292 addAccelObjC(Category, Die);
293 // Also add the base method name to the name table.
294 addAccelName(getObjCMethodName(SP.getName()), Die);
298 /// isSubprogramContext - Return true if Context is either a subprogram
299 /// or another context nested inside a subprogram.
300 bool DwarfDebug::isSubprogramContext(const MDNode *Context) {
303 DIDescriptor D(Context);
304 if (D.isSubprogram())
307 return isSubprogramContext(resolve(DIType(Context).getContext()));
311 // Find DIE for the given subprogram and attach appropriate DW_AT_low_pc
312 // and DW_AT_high_pc attributes. If there are global variables in this
313 // scope then create and insert DIEs for these variables.
314 DIE *DwarfDebug::updateSubprogramScopeDIE(DwarfCompileUnit &SPCU,
316 DIE *SPDie = SPCU.getDIE(SP);
318 assert(SPDie && "Unable to find subprogram DIE!");
320 // If we're updating an abstract DIE, then we will be adding the children and
321 // object pointer later on. But what we don't want to do is process the
322 // concrete DIE twice.
323 if (DIE *AbsSPDIE = AbstractSPDies.lookup(SP)) {
324 // Pick up abstract subprogram DIE.
325 SPDie = &SPCU.createAndAddDIE(dwarf::DW_TAG_subprogram, SPCU.getUnitDie());
326 SPCU.addDIEEntry(*SPDie, dwarf::DW_AT_abstract_origin, *AbsSPDIE);
328 DISubprogram SPDecl = SP.getFunctionDeclaration();
329 if (!SPDecl.isSubprogram()) {
330 // There is not any need to generate specification DIE for a function
331 // defined at compile unit level. If a function is defined inside another
332 // function then gdb prefers the definition at top level and but does not
333 // expect specification DIE in parent function. So avoid creating
334 // specification DIE for a function defined inside a function.
335 DIScope SPContext = resolve(SP.getContext());
336 if (SP.isDefinition() && !SPContext.isCompileUnit() &&
337 !SPContext.isFile() && !isSubprogramContext(SPContext)) {
338 SPCU.addFlag(*SPDie, dwarf::DW_AT_declaration);
341 DICompositeType SPTy = SP.getType();
342 DIArray Args = SPTy.getTypeArray();
343 uint16_t SPTag = SPTy.getTag();
344 if (SPTag == dwarf::DW_TAG_subroutine_type)
345 SPCU.constructSubprogramArguments(*SPDie, Args);
346 DIE *SPDeclDie = SPDie;
348 &SPCU.createAndAddDIE(dwarf::DW_TAG_subprogram, SPCU.getUnitDie());
349 SPCU.addDIEEntry(*SPDie, dwarf::DW_AT_specification, *SPDeclDie);
354 attachLowHighPC(SPCU, *SPDie, FunctionBeginSym, FunctionEndSym);
356 const TargetRegisterInfo *RI = Asm->TM.getRegisterInfo();
357 MachineLocation Location(RI->getFrameRegister(*Asm->MF));
358 SPCU.addAddress(*SPDie, dwarf::DW_AT_frame_base, Location);
360 // Add name to the name table, we do this here because we're guaranteed
361 // to have concrete versions of our DW_TAG_subprogram nodes.
362 addSubprogramNames(SP, *SPDie);
367 /// Check whether we should create a DIE for the given Scope, return true
368 /// if we don't create a DIE (the corresponding DIE is null).
369 bool DwarfDebug::isLexicalScopeDIENull(LexicalScope *Scope) {
370 if (Scope->isAbstractScope())
373 // We don't create a DIE if there is no Range.
374 const SmallVectorImpl<InsnRange> &Ranges = Scope->getRanges();
378 if (Ranges.size() > 1)
381 // We don't create a DIE if we have a single Range and the end label
383 SmallVectorImpl<InsnRange>::const_iterator RI = Ranges.begin();
384 MCSymbol *End = getLabelAfterInsn(RI->second);
388 static void addSectionLabel(AsmPrinter &Asm, DwarfUnit &U, DIE &D,
389 dwarf::Attribute A, const MCSymbol *L,
390 const MCSymbol *Sec) {
391 if (Asm.MAI->doesDwarfUseRelocationsAcrossSections())
392 U.addSectionLabel(D, A, L);
394 U.addSectionDelta(D, A, L, Sec);
397 void DwarfDebug::addScopeRangeList(DwarfCompileUnit &TheCU, DIE &ScopeDIE,
398 const SmallVectorImpl<InsnRange> &Range) {
399 // Emit offset in .debug_range as a relocatable label. emitDIE will handle
400 // emitting it appropriately.
401 MCSymbol *RangeSym = Asm->GetTempSymbol("debug_ranges", GlobalRangeCount++);
403 // Under fission, ranges are specified by constant offsets relative to the
404 // CU's DW_AT_GNU_ranges_base.
406 TheCU.addSectionDelta(ScopeDIE, dwarf::DW_AT_ranges, RangeSym,
407 DwarfDebugRangeSectionSym);
409 addSectionLabel(*Asm, TheCU, ScopeDIE, dwarf::DW_AT_ranges, RangeSym,
410 DwarfDebugRangeSectionSym);
412 RangeSpanList List(RangeSym);
413 for (const InsnRange &R : Range) {
414 RangeSpan Span(getLabelBeforeInsn(R.first), getLabelAfterInsn(R.second));
415 List.addRange(std::move(Span));
418 // Add the range list to the set of ranges to be emitted.
419 TheCU.addRangeList(std::move(List));
422 // Construct new DW_TAG_lexical_block for this scope and attach
423 // DW_AT_low_pc/DW_AT_high_pc labels.
424 DIE *DwarfDebug::constructLexicalScopeDIE(DwarfCompileUnit &TheCU,
425 LexicalScope *Scope) {
426 if (isLexicalScopeDIENull(Scope))
429 DIE *ScopeDIE = new DIE(dwarf::DW_TAG_lexical_block);
430 if (Scope->isAbstractScope())
433 const SmallVectorImpl<InsnRange> &ScopeRanges = Scope->getRanges();
435 // If we have multiple ranges, emit them into the range section.
436 if (ScopeRanges.size() > 1) {
437 addScopeRangeList(TheCU, *ScopeDIE, ScopeRanges);
441 // Construct the address range for this DIE.
442 SmallVectorImpl<InsnRange>::const_iterator RI = ScopeRanges.begin();
443 MCSymbol *Start = getLabelBeforeInsn(RI->first);
444 MCSymbol *End = getLabelAfterInsn(RI->second);
445 assert(End && "End label should not be null!");
447 assert(Start->isDefined() && "Invalid starting label for an inlined scope!");
448 assert(End->isDefined() && "Invalid end label for an inlined scope!");
450 attachLowHighPC(TheCU, *ScopeDIE, Start, End);
455 // This scope represents inlined body of a function. Construct DIE to
456 // represent this concrete inlined copy of the function.
457 DIE *DwarfDebug::constructInlinedScopeDIE(DwarfCompileUnit &TheCU,
458 LexicalScope *Scope) {
459 const SmallVectorImpl<InsnRange> &ScopeRanges = Scope->getRanges();
460 assert(!ScopeRanges.empty() &&
461 "LexicalScope does not have instruction markers!");
463 if (!Scope->getScopeNode())
465 DIScope DS(Scope->getScopeNode());
466 DISubprogram InlinedSP = getDISubprogram(DS);
467 DIE *OriginDIE = TheCU.getDIE(InlinedSP);
469 DEBUG(dbgs() << "Unable to find original DIE for an inlined subprogram.");
473 DIE *ScopeDIE = new DIE(dwarf::DW_TAG_inlined_subroutine);
474 TheCU.addDIEEntry(*ScopeDIE, dwarf::DW_AT_abstract_origin, *OriginDIE);
476 // If we have multiple ranges, emit them into the range section.
477 if (ScopeRanges.size() > 1)
478 addScopeRangeList(TheCU, *ScopeDIE, ScopeRanges);
480 SmallVectorImpl<InsnRange>::const_iterator RI = ScopeRanges.begin();
481 MCSymbol *StartLabel = getLabelBeforeInsn(RI->first);
482 MCSymbol *EndLabel = getLabelAfterInsn(RI->second);
484 if (!StartLabel || !EndLabel)
485 llvm_unreachable("Unexpected Start and End labels for an inlined scope!");
487 assert(StartLabel->isDefined() &&
488 "Invalid starting label for an inlined scope!");
489 assert(EndLabel->isDefined() && "Invalid end label for an inlined scope!");
491 attachLowHighPC(TheCU, *ScopeDIE, StartLabel, EndLabel);
494 InlinedSubprogramDIEs.insert(OriginDIE);
496 // Add the call site information to the DIE.
497 DILocation DL(Scope->getInlinedAt());
498 TheCU.addUInt(*ScopeDIE, dwarf::DW_AT_call_file, None,
499 TheCU.getOrCreateSourceID(DL.getFilename(), DL.getDirectory()));
500 TheCU.addUInt(*ScopeDIE, dwarf::DW_AT_call_line, None, DL.getLineNumber());
502 // Add name to the name table, we do this here because we're guaranteed
503 // to have concrete versions of our DW_TAG_inlined_subprogram nodes.
504 addSubprogramNames(InlinedSP, *ScopeDIE);
509 DIE *DwarfDebug::createScopeChildrenDIE(
510 DwarfCompileUnit &TheCU, LexicalScope *Scope,
511 SmallVectorImpl<std::unique_ptr<DIE>> &Children) {
512 DIE *ObjectPointer = nullptr;
514 // Collect arguments for current function.
515 if (LScopes.isCurrentFunctionScope(Scope)) {
516 for (DbgVariable *ArgDV : CurrentFnArguments)
519 TheCU.constructVariableDIE(*ArgDV, Scope->isAbstractScope()));
520 if (ArgDV->isObjectPointer())
521 ObjectPointer = Children.back().get();
524 // If this is a variadic function, add an unspecified parameter.
525 DISubprogram SP(Scope->getScopeNode());
526 DIArray FnArgs = SP.getType().getTypeArray();
527 if (FnArgs.getElement(FnArgs.getNumElements() - 1)
528 .isUnspecifiedParameter()) {
530 make_unique<DIE>(dwarf::DW_TAG_unspecified_parameters));
534 // Collect lexical scope children first.
535 for (DbgVariable *DV : ScopeVariables.lookup(Scope)) {
537 TheCU.constructVariableDIE(*DV, Scope->isAbstractScope()));
538 if (DV->isObjectPointer())
539 ObjectPointer = Children.back().get();
541 for (LexicalScope *LS : Scope->getChildren())
542 if (DIE *Nested = constructScopeDIE(TheCU, LS))
543 Children.push_back(std::unique_ptr<DIE>(Nested));
544 return ObjectPointer;
547 // Construct a DIE for this scope.
548 DIE *DwarfDebug::constructScopeDIE(DwarfCompileUnit &TheCU,
549 LexicalScope *Scope) {
550 if (!Scope || !Scope->getScopeNode())
553 DIScope DS(Scope->getScopeNode());
555 SmallVector<std::unique_ptr<DIE>, 8> Children;
556 DIE *ObjectPointer = nullptr;
557 bool ChildrenCreated = false;
559 // We try to create the scope DIE first, then the children DIEs. This will
560 // avoid creating un-used children then removing them later when we find out
561 // the scope DIE is null.
562 DIE *ScopeDIE = nullptr;
563 if (Scope->getInlinedAt())
564 ScopeDIE = constructInlinedScopeDIE(TheCU, Scope);
565 else if (DS.isSubprogram()) {
566 ProcessedSPNodes.insert(DS);
567 if (Scope->isAbstractScope()) {
568 ScopeDIE = TheCU.getDIE(DS);
569 // Note down abstract DIE.
571 AbstractSPDies.insert(std::make_pair(DS, ScopeDIE));
573 ScopeDIE = updateSubprogramScopeDIE(TheCU, DISubprogram(DS));
575 // Early exit when we know the scope DIE is going to be null.
576 if (isLexicalScopeDIENull(Scope))
579 // We create children here when we know the scope DIE is not going to be
580 // null and the children will be added to the scope DIE.
581 ObjectPointer = createScopeChildrenDIE(TheCU, Scope, Children);
582 ChildrenCreated = true;
584 // There is no need to emit empty lexical block DIE.
585 std::pair<ImportedEntityMap::const_iterator,
586 ImportedEntityMap::const_iterator> Range =
588 ScopesWithImportedEntities.begin(),
589 ScopesWithImportedEntities.end(),
590 std::pair<const MDNode *, const MDNode *>(DS, nullptr),
592 if (Children.empty() && Range.first == Range.second)
594 ScopeDIE = constructLexicalScopeDIE(TheCU, Scope);
595 assert(ScopeDIE && "Scope DIE should not be null.");
596 for (ImportedEntityMap::const_iterator i = Range.first; i != Range.second;
598 constructImportedEntityDIE(TheCU, i->second, ScopeDIE);
602 assert(Children.empty() &&
603 "We create children only when the scope DIE is not null.");
606 if (!ChildrenCreated)
607 // We create children when the scope DIE is not null.
608 ObjectPointer = createScopeChildrenDIE(TheCU, Scope, Children);
611 for (auto &I : Children)
612 ScopeDIE->addChild(std::move(I));
614 if (DS.isSubprogram() && ObjectPointer != nullptr)
615 TheCU.addDIEEntry(*ScopeDIE, dwarf::DW_AT_object_pointer, *ObjectPointer);
620 void DwarfDebug::addGnuPubAttributes(DwarfUnit &U, DIE &D) const {
621 if (!GenerateGnuPubSections)
624 U.addFlag(D, dwarf::DW_AT_GNU_pubnames);
627 // Create new DwarfCompileUnit for the given metadata node with tag
628 // DW_TAG_compile_unit.
629 DwarfCompileUnit &DwarfDebug::constructDwarfCompileUnit(DICompileUnit DIUnit) {
630 StringRef FN = DIUnit.getFilename();
631 CompilationDir = DIUnit.getDirectory();
633 DIE *Die = new DIE(dwarf::DW_TAG_compile_unit);
634 auto OwnedUnit = make_unique<DwarfCompileUnit>(
635 InfoHolder.getUnits().size(), Die, DIUnit, Asm, this, &InfoHolder);
636 DwarfCompileUnit &NewCU = *OwnedUnit;
637 InfoHolder.addUnit(std::move(OwnedUnit));
639 // LTO with assembly output shares a single line table amongst multiple CUs.
640 // To avoid the compilation directory being ambiguous, let the line table
641 // explicitly describe the directory of all files, never relying on the
642 // compilation directory.
643 if (!Asm->OutStreamer.hasRawTextSupport() || SingleCU)
644 Asm->OutStreamer.getContext().setMCLineTableCompilationDir(
645 NewCU.getUniqueID(), CompilationDir);
647 NewCU.addString(*Die, dwarf::DW_AT_producer, DIUnit.getProducer());
648 NewCU.addUInt(*Die, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
649 DIUnit.getLanguage());
650 NewCU.addString(*Die, dwarf::DW_AT_name, FN);
652 if (!useSplitDwarf()) {
653 NewCU.initStmtList(DwarfLineSectionSym);
655 // If we're using split dwarf the compilation dir is going to be in the
656 // skeleton CU and so we don't need to duplicate it here.
657 if (!CompilationDir.empty())
658 NewCU.addString(*Die, dwarf::DW_AT_comp_dir, CompilationDir);
660 addGnuPubAttributes(NewCU, *Die);
663 if (DIUnit.isOptimized())
664 NewCU.addFlag(*Die, dwarf::DW_AT_APPLE_optimized);
666 StringRef Flags = DIUnit.getFlags();
668 NewCU.addString(*Die, dwarf::DW_AT_APPLE_flags, Flags);
670 if (unsigned RVer = DIUnit.getRunTimeVersion())
671 NewCU.addUInt(*Die, dwarf::DW_AT_APPLE_major_runtime_vers,
672 dwarf::DW_FORM_data1, RVer);
677 if (useSplitDwarf()) {
678 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoDWOSection(),
679 DwarfInfoDWOSectionSym);
680 NewCU.setSkeleton(constructSkeletonCU(NewCU));
682 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoSection(),
683 DwarfInfoSectionSym);
685 CUMap.insert(std::make_pair(DIUnit, &NewCU));
686 CUDieMap.insert(std::make_pair(Die, &NewCU));
690 // Construct subprogram DIE.
691 void DwarfDebug::constructSubprogramDIE(DwarfCompileUnit &TheCU,
693 // FIXME: We should only call this routine once, however, during LTO if a
694 // program is defined in multiple CUs we could end up calling it out of
695 // beginModule as we walk the CUs.
697 DwarfCompileUnit *&CURef = SPMap[N];
703 if (!SP.isDefinition())
704 // This is a method declaration which will be handled while constructing
708 DIE &SubprogramDie = *TheCU.getOrCreateSubprogramDIE(SP);
710 // Expose as a global name.
711 TheCU.addGlobalName(SP.getName(), SubprogramDie, resolve(SP.getContext()));
714 void DwarfDebug::constructImportedEntityDIE(DwarfCompileUnit &TheCU,
716 DIImportedEntity Module(N);
717 assert(Module.Verify());
718 if (DIE *D = TheCU.getOrCreateContextDIE(Module.getContext()))
719 constructImportedEntityDIE(TheCU, Module, D);
722 void DwarfDebug::constructImportedEntityDIE(DwarfCompileUnit &TheCU,
723 const MDNode *N, DIE *Context) {
724 DIImportedEntity Module(N);
725 assert(Module.Verify());
726 return constructImportedEntityDIE(TheCU, Module, Context);
729 void DwarfDebug::constructImportedEntityDIE(DwarfCompileUnit &TheCU,
730 const DIImportedEntity &Module,
732 assert(Module.Verify() &&
733 "Use one of the MDNode * overloads to handle invalid metadata");
734 assert(Context && "Should always have a context for an imported_module");
735 DIE &IMDie = TheCU.createAndAddDIE(Module.getTag(), *Context, Module);
737 DIDescriptor Entity = resolve(Module.getEntity());
738 if (Entity.isNameSpace())
739 EntityDie = TheCU.getOrCreateNameSpace(DINameSpace(Entity));
740 else if (Entity.isSubprogram())
741 EntityDie = TheCU.getOrCreateSubprogramDIE(DISubprogram(Entity));
742 else if (Entity.isType())
743 EntityDie = TheCU.getOrCreateTypeDIE(DIType(Entity));
745 EntityDie = TheCU.getDIE(Entity);
746 TheCU.addSourceLine(IMDie, Module.getLineNumber(),
747 Module.getContext().getFilename(),
748 Module.getContext().getDirectory());
749 TheCU.addDIEEntry(IMDie, dwarf::DW_AT_import, *EntityDie);
750 StringRef Name = Module.getName();
752 TheCU.addString(IMDie, dwarf::DW_AT_name, Name);
755 // Emit all Dwarf sections that should come prior to the content. Create
756 // global DIEs and emit initial debug info sections. This is invoked by
757 // the target AsmPrinter.
758 void DwarfDebug::beginModule() {
759 if (DisableDebugInfoPrinting)
762 const Module *M = MMI->getModule();
764 // If module has named metadata anchors then use them, otherwise scan the
765 // module using debug info finder to collect debug info.
766 NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
769 TypeIdentifierMap = generateDITypeIdentifierMap(CU_Nodes);
771 // Emit initial sections so we can reference labels later.
774 SingleCU = CU_Nodes->getNumOperands() == 1;
776 for (MDNode *N : CU_Nodes->operands()) {
777 DICompileUnit CUNode(N);
778 DwarfCompileUnit &CU = constructDwarfCompileUnit(CUNode);
779 DIArray ImportedEntities = CUNode.getImportedEntities();
780 for (unsigned i = 0, e = ImportedEntities.getNumElements(); i != e; ++i)
781 ScopesWithImportedEntities.push_back(std::make_pair(
782 DIImportedEntity(ImportedEntities.getElement(i)).getContext(),
783 ImportedEntities.getElement(i)));
784 std::sort(ScopesWithImportedEntities.begin(),
785 ScopesWithImportedEntities.end(), less_first());
786 DIArray GVs = CUNode.getGlobalVariables();
787 for (unsigned i = 0, e = GVs.getNumElements(); i != e; ++i)
788 CU.createGlobalVariableDIE(DIGlobalVariable(GVs.getElement(i)));
789 DIArray SPs = CUNode.getSubprograms();
790 for (unsigned i = 0, e = SPs.getNumElements(); i != e; ++i)
791 constructSubprogramDIE(CU, SPs.getElement(i));
792 DIArray EnumTypes = CUNode.getEnumTypes();
793 for (unsigned i = 0, e = EnumTypes.getNumElements(); i != e; ++i)
794 CU.getOrCreateTypeDIE(EnumTypes.getElement(i));
795 DIArray RetainedTypes = CUNode.getRetainedTypes();
796 for (unsigned i = 0, e = RetainedTypes.getNumElements(); i != e; ++i) {
797 DIType Ty(RetainedTypes.getElement(i));
798 // The retained types array by design contains pointers to
799 // MDNodes rather than DIRefs. Unique them here.
800 DIType UniqueTy(resolve(Ty.getRef()));
801 CU.getOrCreateTypeDIE(UniqueTy);
803 // Emit imported_modules last so that the relevant context is already
805 for (unsigned i = 0, e = ImportedEntities.getNumElements(); i != e; ++i)
806 constructImportedEntityDIE(CU, ImportedEntities.getElement(i));
809 // Tell MMI that we have debug info.
810 MMI->setDebugInfoAvailability(true);
812 // Prime section data.
813 SectionMap[Asm->getObjFileLowering().getTextSection()];
816 // Attach DW_AT_inline attribute with inlined subprogram DIEs.
817 void DwarfDebug::computeInlinedDIEs() {
818 // Attach DW_AT_inline attribute with inlined subprogram DIEs.
819 for (DIE *ISP : InlinedSubprogramDIEs)
820 FirstCU->addUInt(*ISP, dwarf::DW_AT_inline, None, dwarf::DW_INL_inlined);
822 for (const auto &AI : AbstractSPDies) {
823 DIE &ISP = *AI.second;
824 if (InlinedSubprogramDIEs.count(&ISP))
826 FirstCU->addUInt(ISP, dwarf::DW_AT_inline, None, dwarf::DW_INL_inlined);
830 // Collect info for variables that were optimized out.
831 void DwarfDebug::collectDeadVariables() {
832 const Module *M = MMI->getModule();
834 if (NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu")) {
835 for (MDNode *N : CU_Nodes->operands()) {
836 DICompileUnit TheCU(N);
837 DIArray Subprograms = TheCU.getSubprograms();
838 for (unsigned i = 0, e = Subprograms.getNumElements(); i != e; ++i) {
839 DISubprogram SP(Subprograms.getElement(i));
840 if (ProcessedSPNodes.count(SP) != 0)
842 if (!SP.isSubprogram())
844 if (!SP.isDefinition())
846 DIArray Variables = SP.getVariables();
847 if (Variables.getNumElements() == 0)
850 // Construct subprogram DIE and add variables DIEs.
851 DwarfCompileUnit *SPCU =
852 static_cast<DwarfCompileUnit *>(CUMap.lookup(TheCU));
853 assert(SPCU && "Unable to find Compile Unit!");
854 // FIXME: See the comment in constructSubprogramDIE about duplicate
856 constructSubprogramDIE(*SPCU, SP);
857 DIE *SPDIE = SPCU->getDIE(SP);
858 for (unsigned vi = 0, ve = Variables.getNumElements(); vi != ve; ++vi) {
859 DIVariable DV(Variables.getElement(vi));
860 if (!DV.isVariable())
862 DbgVariable NewVar(DV, nullptr, this);
863 SPDIE->addChild(SPCU->constructVariableDIE(NewVar, false));
870 void DwarfDebug::finalizeModuleInfo() {
871 // Collect info for variables that were optimized out.
872 collectDeadVariables();
874 // Attach DW_AT_inline attribute with inlined subprogram DIEs.
875 computeInlinedDIEs();
877 // Handle anything that needs to be done on a per-unit basis after
878 // all other generation.
879 for (const auto &TheU : getUnits()) {
880 // Emit DW_AT_containing_type attribute to connect types with their
881 // vtable holding type.
882 TheU->constructContainingTypeDIEs();
884 // Add CU specific attributes if we need to add any.
885 if (TheU->getUnitDie().getTag() == dwarf::DW_TAG_compile_unit) {
886 // If we're splitting the dwarf out now that we've got the entire
887 // CU then add the dwo id to it.
888 DwarfCompileUnit *SkCU =
889 static_cast<DwarfCompileUnit *>(TheU->getSkeleton());
890 if (useSplitDwarf()) {
891 // Emit a unique identifier for this CU.
892 uint64_t ID = DIEHash(Asm).computeCUSignature(TheU->getUnitDie());
893 TheU->addUInt(TheU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
894 dwarf::DW_FORM_data8, ID);
895 SkCU->addUInt(SkCU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
896 dwarf::DW_FORM_data8, ID);
898 // We don't keep track of which addresses are used in which CU so this
899 // is a bit pessimistic under LTO.
900 if (!AddrPool.isEmpty())
901 addSectionLabel(*Asm, *SkCU, SkCU->getUnitDie(),
902 dwarf::DW_AT_GNU_addr_base, DwarfAddrSectionSym,
903 DwarfAddrSectionSym);
904 if (!TheU->getRangeLists().empty())
905 addSectionLabel(*Asm, *SkCU, SkCU->getUnitDie(),
906 dwarf::DW_AT_GNU_ranges_base,
907 DwarfDebugRangeSectionSym, DwarfDebugRangeSectionSym);
910 // If we have code split among multiple sections or non-contiguous
911 // ranges of code then emit a DW_AT_ranges attribute on the unit that will
912 // remain in the .o file, otherwise add a DW_AT_low_pc.
913 // FIXME: We should use ranges allow reordering of code ala
914 // .subsections_via_symbols in mach-o. This would mean turning on
915 // ranges for all subprogram DIEs for mach-o.
916 DwarfCompileUnit &U =
917 SkCU ? *SkCU : static_cast<DwarfCompileUnit &>(*TheU);
918 unsigned NumRanges = TheU->getRanges().size();
921 addSectionLabel(*Asm, U, U.getUnitDie(), dwarf::DW_AT_ranges,
922 Asm->GetTempSymbol("cu_ranges", U.getUniqueID()),
923 DwarfDebugRangeSectionSym);
925 // A DW_AT_low_pc attribute may also be specified in combination with
926 // DW_AT_ranges to specify the default base address for use in
927 // location lists (see Section 2.6.2) and range lists (see Section
929 U.addUInt(U.getUnitDie(), dwarf::DW_AT_low_pc, dwarf::DW_FORM_addr,
932 RangeSpan &Range = TheU->getRanges().back();
933 U.addLocalLabelAddress(U.getUnitDie(), dwarf::DW_AT_low_pc,
935 U.addLabelDelta(U.getUnitDie(), dwarf::DW_AT_high_pc, Range.getEnd(),
942 // Compute DIE offsets and sizes.
943 InfoHolder.computeSizeAndOffsets();
945 SkeletonHolder.computeSizeAndOffsets();
948 void DwarfDebug::endSections() {
949 // Filter labels by section.
950 for (const SymbolCU &SCU : ArangeLabels) {
951 if (SCU.Sym->isInSection()) {
952 // Make a note of this symbol and it's section.
953 const MCSection *Section = &SCU.Sym->getSection();
954 if (!Section->getKind().isMetadata())
955 SectionMap[Section].push_back(SCU);
957 // Some symbols (e.g. common/bss on mach-o) can have no section but still
958 // appear in the output. This sucks as we rely on sections to build
959 // arange spans. We can do it without, but it's icky.
960 SectionMap[nullptr].push_back(SCU);
964 // Build a list of sections used.
965 std::vector<const MCSection *> Sections;
966 for (const auto &it : SectionMap) {
967 const MCSection *Section = it.first;
968 Sections.push_back(Section);
971 // Sort the sections into order.
972 // This is only done to ensure consistent output order across different runs.
973 std::sort(Sections.begin(), Sections.end(), SectionSort);
975 // Add terminating symbols for each section.
976 for (unsigned ID = 0, E = Sections.size(); ID != E; ID++) {
977 const MCSection *Section = Sections[ID];
978 MCSymbol *Sym = nullptr;
981 // We can't call MCSection::getLabelEndName, as it's only safe to do so
982 // if we know the section name up-front. For user-created sections, the
983 // resulting label may not be valid to use as a label. (section names can
984 // use a greater set of characters on some systems)
985 Sym = Asm->GetTempSymbol("debug_end", ID);
986 Asm->OutStreamer.SwitchSection(Section);
987 Asm->OutStreamer.EmitLabel(Sym);
990 // Insert a final terminator.
991 SectionMap[Section].push_back(SymbolCU(nullptr, Sym));
995 // Emit all Dwarf sections that should come after the content.
996 void DwarfDebug::endModule() {
1003 // End any existing sections.
1004 // TODO: Does this need to happen?
1007 // Finalize the debug info for the module.
1008 finalizeModuleInfo();
1012 // Emit all the DIEs into a debug info section.
1015 // Corresponding abbreviations into a abbrev section.
1016 emitAbbreviations();
1018 // Emit info into a debug aranges section.
1019 if (GenerateARangeSection)
1022 // Emit info into a debug ranges section.
1025 if (useSplitDwarf()) {
1028 emitDebugAbbrevDWO();
1030 // Emit DWO addresses.
1031 AddrPool.emit(*Asm, Asm->getObjFileLowering().getDwarfAddrSection());
1034 // Emit info into a debug loc section.
1037 // Emit info into the dwarf accelerator table sections.
1038 if (useDwarfAccelTables()) {
1041 emitAccelNamespaces();
1045 // Emit the pubnames and pubtypes sections if requested.
1046 if (HasDwarfPubSections) {
1047 emitDebugPubNames(GenerateGnuPubSections);
1048 emitDebugPubTypes(GenerateGnuPubSections);
1054 // Reset these for the next Module if we have one.
1058 // Find abstract variable, if any, associated with Var.
1059 DbgVariable *DwarfDebug::findAbstractVariable(DIVariable &DV,
1060 DebugLoc ScopeLoc) {
1061 LLVMContext &Ctx = DV->getContext();
1062 // More then one inlined variable corresponds to one abstract variable.
1063 DIVariable Var = cleanseInlinedVariable(DV, Ctx);
1064 DbgVariable *AbsDbgVariable = AbstractVariables.lookup(Var);
1066 return AbsDbgVariable;
1068 LexicalScope *Scope = LScopes.findAbstractScope(ScopeLoc.getScope(Ctx));
1072 AbsDbgVariable = new DbgVariable(Var, nullptr, this);
1073 addScopeVariable(Scope, AbsDbgVariable);
1074 AbstractVariables[Var] = AbsDbgVariable;
1075 return AbsDbgVariable;
1078 // If Var is a current function argument then add it to CurrentFnArguments list.
1079 bool DwarfDebug::addCurrentFnArgument(DbgVariable *Var, LexicalScope *Scope) {
1080 if (!LScopes.isCurrentFunctionScope(Scope))
1082 DIVariable DV = Var->getVariable();
1083 if (DV.getTag() != dwarf::DW_TAG_arg_variable)
1085 unsigned ArgNo = DV.getArgNumber();
1089 size_t Size = CurrentFnArguments.size();
1091 CurrentFnArguments.resize(CurFn->getFunction()->arg_size());
1092 // llvm::Function argument size is not good indicator of how many
1093 // arguments does the function have at source level.
1095 CurrentFnArguments.resize(ArgNo * 2);
1096 CurrentFnArguments[ArgNo - 1] = Var;
1100 // Collect variable information from side table maintained by MMI.
1101 void DwarfDebug::collectVariableInfoFromMMITable(
1102 SmallPtrSet<const MDNode *, 16> &Processed) {
1103 for (const auto &VI : MMI->getVariableDbgInfo()) {
1106 Processed.insert(VI.Var);
1107 DIVariable DV(VI.Var);
1108 LexicalScope *Scope = LScopes.findLexicalScope(VI.Loc);
1110 // If variable scope is not found then skip this variable.
1114 DbgVariable *AbsDbgVariable = findAbstractVariable(DV, VI.Loc);
1115 DbgVariable *RegVar = new DbgVariable(DV, AbsDbgVariable, this);
1116 RegVar->setFrameIndex(VI.Slot);
1117 if (!addCurrentFnArgument(RegVar, Scope))
1118 addScopeVariable(Scope, RegVar);
1120 AbsDbgVariable->setFrameIndex(VI.Slot);
1124 // Return true if debug value, encoded by DBG_VALUE instruction, is in a
1126 static bool isDbgValueInDefinedReg(const MachineInstr *MI) {
1127 assert(MI->isDebugValue() && "Invalid DBG_VALUE machine instruction!");
1128 return MI->getNumOperands() == 3 && MI->getOperand(0).isReg() &&
1129 MI->getOperand(0).getReg() &&
1130 (MI->getOperand(1).isImm() ||
1131 (MI->getOperand(1).isReg() && MI->getOperand(1).getReg() == 0U));
1134 // Get .debug_loc entry for the instruction range starting at MI.
1135 static DebugLocEntry::Value getDebugLocValue(const MachineInstr *MI) {
1136 const MDNode *Var = MI->getDebugVariable();
1138 assert(MI->getNumOperands() == 3);
1139 if (MI->getOperand(0).isReg()) {
1140 MachineLocation MLoc;
1141 // If the second operand is an immediate, this is a
1142 // register-indirect address.
1143 if (!MI->getOperand(1).isImm())
1144 MLoc.set(MI->getOperand(0).getReg());
1146 MLoc.set(MI->getOperand(0).getReg(), MI->getOperand(1).getImm());
1147 return DebugLocEntry::Value(Var, MLoc);
1149 if (MI->getOperand(0).isImm())
1150 return DebugLocEntry::Value(Var, MI->getOperand(0).getImm());
1151 if (MI->getOperand(0).isFPImm())
1152 return DebugLocEntry::Value(Var, MI->getOperand(0).getFPImm());
1153 if (MI->getOperand(0).isCImm())
1154 return DebugLocEntry::Value(Var, MI->getOperand(0).getCImm());
1156 llvm_unreachable("Unexpected 3 operand DBG_VALUE instruction!");
1159 // Find variables for each lexical scope.
1161 DwarfDebug::collectVariableInfo(SmallPtrSet<const MDNode *, 16> &Processed) {
1162 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1163 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1165 // Grab the variable info that was squirreled away in the MMI side-table.
1166 collectVariableInfoFromMMITable(Processed);
1168 for (const MDNode *Var : UserVariables) {
1169 if (Processed.count(Var))
1172 // History contains relevant DBG_VALUE instructions for Var and instructions
1174 SmallVectorImpl<const MachineInstr *> &History = DbgValues[Var];
1175 if (History.empty())
1177 const MachineInstr *MInsn = History.front();
1180 LexicalScope *Scope = nullptr;
1181 if (DV.getTag() == dwarf::DW_TAG_arg_variable &&
1182 DISubprogram(DV.getContext()).describes(CurFn->getFunction()))
1183 Scope = LScopes.getCurrentFunctionScope();
1184 else if (MDNode *IA = DV.getInlinedAt())
1185 Scope = LScopes.findInlinedScope(DebugLoc::getFromDILocation(IA));
1187 Scope = LScopes.findLexicalScope(cast<MDNode>(DV->getOperand(1)));
1188 // If variable scope is not found then skip this variable.
1192 Processed.insert(DV);
1193 assert(MInsn->isDebugValue() && "History must begin with debug value");
1194 DbgVariable *AbsVar = findAbstractVariable(DV, MInsn->getDebugLoc());
1195 DbgVariable *RegVar = new DbgVariable(DV, AbsVar, this);
1196 if (!addCurrentFnArgument(RegVar, Scope))
1197 addScopeVariable(Scope, RegVar);
1199 AbsVar->setMInsn(MInsn);
1201 // Simplify ranges that are fully coalesced.
1202 if (History.size() <= 1 ||
1203 (History.size() == 2 && MInsn->isIdenticalTo(History.back()))) {
1204 RegVar->setMInsn(MInsn);
1208 // Handle multiple DBG_VALUE instructions describing one variable.
1209 RegVar->setDotDebugLocOffset(DotDebugLocEntries.size());
1211 DotDebugLocEntries.resize(DotDebugLocEntries.size() + 1);
1212 DebugLocList &LocList = DotDebugLocEntries.back();
1214 Asm->GetTempSymbol("debug_loc", DotDebugLocEntries.size() - 1);
1215 SmallVector<DebugLocEntry, 4> &DebugLoc = LocList.List;
1216 for (SmallVectorImpl<const MachineInstr *>::const_iterator
1217 HI = History.begin(),
1220 const MachineInstr *Begin = *HI;
1221 assert(Begin->isDebugValue() && "Invalid History entry");
1223 // Check if DBG_VALUE is truncating a range.
1224 if (Begin->getNumOperands() > 1 && Begin->getOperand(0).isReg() &&
1225 !Begin->getOperand(0).getReg())
1228 // Compute the range for a register location.
1229 const MCSymbol *FLabel = getLabelBeforeInsn(Begin);
1230 const MCSymbol *SLabel = nullptr;
1233 // If Begin is the last instruction in History then its value is valid
1234 // until the end of the function.
1235 SLabel = FunctionEndSym;
1237 const MachineInstr *End = HI[1];
1238 DEBUG(dbgs() << "DotDebugLoc Pair:\n"
1239 << "\t" << *Begin << "\t" << *End << "\n");
1240 if (End->isDebugValue())
1241 SLabel = getLabelBeforeInsn(End);
1243 // End is a normal instruction clobbering the range.
1244 SLabel = getLabelAfterInsn(End);
1245 assert(SLabel && "Forgot label after clobber instruction");
1250 // The value is valid until the next DBG_VALUE or clobber.
1251 DebugLocEntry Loc(FLabel, SLabel, getDebugLocValue(Begin), TheCU);
1252 if (DebugLoc.empty() || !DebugLoc.back().Merge(Loc))
1253 DebugLoc.push_back(std::move(Loc));
1257 // Collect info for variables that were optimized out.
1258 DIArray Variables = DISubprogram(FnScope->getScopeNode()).getVariables();
1259 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1260 DIVariable DV(Variables.getElement(i));
1261 if (!DV || !DV.isVariable() || !Processed.insert(DV))
1263 if (LexicalScope *Scope = LScopes.findLexicalScope(DV.getContext()))
1264 addScopeVariable(Scope, new DbgVariable(DV, nullptr, this));
1268 // Return Label preceding the instruction.
1269 MCSymbol *DwarfDebug::getLabelBeforeInsn(const MachineInstr *MI) {
1270 MCSymbol *Label = LabelsBeforeInsn.lookup(MI);
1271 assert(Label && "Didn't insert label before instruction");
1275 // Return Label immediately following the instruction.
1276 MCSymbol *DwarfDebug::getLabelAfterInsn(const MachineInstr *MI) {
1277 return LabelsAfterInsn.lookup(MI);
1280 // Process beginning of an instruction.
1281 void DwarfDebug::beginInstruction(const MachineInstr *MI) {
1284 // Check if source location changes, but ignore DBG_VALUE locations.
1285 if (!MI->isDebugValue()) {
1286 DebugLoc DL = MI->getDebugLoc();
1287 if (DL != PrevInstLoc && (!DL.isUnknown() || UnknownLocations)) {
1290 if (DL == PrologEndLoc) {
1291 Flags |= DWARF2_FLAG_PROLOGUE_END;
1292 PrologEndLoc = DebugLoc();
1294 if (PrologEndLoc.isUnknown())
1295 Flags |= DWARF2_FLAG_IS_STMT;
1297 if (!DL.isUnknown()) {
1298 const MDNode *Scope = DL.getScope(Asm->MF->getFunction()->getContext());
1299 recordSourceLine(DL.getLine(), DL.getCol(), Scope, Flags);
1301 recordSourceLine(0, 0, nullptr, 0);
1305 // Insert labels where requested.
1306 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1307 LabelsBeforeInsn.find(MI);
1310 if (I == LabelsBeforeInsn.end())
1313 // Label already assigned.
1318 PrevLabel = MMI->getContext().CreateTempSymbol();
1319 Asm->OutStreamer.EmitLabel(PrevLabel);
1321 I->second = PrevLabel;
1324 // Process end of an instruction.
1325 void DwarfDebug::endInstruction() {
1327 // Don't create a new label after DBG_VALUE instructions.
1328 // They don't generate code.
1329 if (!CurMI->isDebugValue())
1330 PrevLabel = nullptr;
1332 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1333 LabelsAfterInsn.find(CurMI);
1337 if (I == LabelsAfterInsn.end())
1340 // Label already assigned.
1344 // We need a label after this instruction.
1346 PrevLabel = MMI->getContext().CreateTempSymbol();
1347 Asm->OutStreamer.EmitLabel(PrevLabel);
1349 I->second = PrevLabel;
1352 // Each LexicalScope has first instruction and last instruction to mark
1353 // beginning and end of a scope respectively. Create an inverse map that list
1354 // scopes starts (and ends) with an instruction. One instruction may start (or
1355 // end) multiple scopes. Ignore scopes that are not reachable.
1356 void DwarfDebug::identifyScopeMarkers() {
1357 SmallVector<LexicalScope *, 4> WorkList;
1358 WorkList.push_back(LScopes.getCurrentFunctionScope());
1359 while (!WorkList.empty()) {
1360 LexicalScope *S = WorkList.pop_back_val();
1362 const SmallVectorImpl<LexicalScope *> &Children = S->getChildren();
1363 if (!Children.empty())
1364 WorkList.append(Children.begin(), Children.end());
1366 if (S->isAbstractScope())
1369 for (const InsnRange &R : S->getRanges()) {
1370 assert(R.first && "InsnRange does not have first instruction!");
1371 assert(R.second && "InsnRange does not have second instruction!");
1372 requestLabelBeforeInsn(R.first);
1373 requestLabelAfterInsn(R.second);
1378 // Gather pre-function debug information. Assumes being called immediately
1379 // after the function entry point has been emitted.
1380 void DwarfDebug::beginFunction(const MachineFunction *MF) {
1383 // If there's no debug info for the function we're not going to do anything.
1384 if (!MMI->hasDebugInfo())
1387 // Grab the lexical scopes for the function, if we don't have any of those
1388 // then we're not going to be able to do anything.
1389 LScopes.initialize(*MF);
1390 if (LScopes.empty())
1393 assert(UserVariables.empty() && DbgValues.empty() && "Maps weren't cleaned");
1395 // Make sure that each lexical scope will have a begin/end label.
1396 identifyScopeMarkers();
1398 // Set DwarfDwarfCompileUnitID in MCContext to the Compile Unit this function
1399 // belongs to so that we add to the correct per-cu line table in the
1401 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1402 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1403 assert(TheCU && "Unable to find compile unit!");
1404 if (Asm->OutStreamer.hasRawTextSupport())
1405 // Use a single line table if we are generating assembly.
1406 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1408 Asm->OutStreamer.getContext().setDwarfCompileUnitID(TheCU->getUniqueID());
1410 // Emit a label for the function so that we have a beginning address.
1411 FunctionBeginSym = Asm->GetTempSymbol("func_begin", Asm->getFunctionNumber());
1412 // Assumes in correct section after the entry point.
1413 Asm->OutStreamer.EmitLabel(FunctionBeginSym);
1415 const TargetRegisterInfo *TRI = Asm->TM.getRegisterInfo();
1416 // LiveUserVar - Map physreg numbers to the MDNode they contain.
1417 std::vector<const MDNode *> LiveUserVar(TRI->getNumRegs());
1419 for (MachineFunction::const_iterator I = MF->begin(), E = MF->end(); I != E;
1421 bool AtBlockEntry = true;
1422 for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end();
1424 const MachineInstr *MI = II;
1426 if (MI->isDebugValue()) {
1427 assert(MI->getNumOperands() > 1 && "Invalid machine instruction!");
1429 // Keep track of user variables.
1430 const MDNode *Var = MI->getDebugVariable();
1432 // Variable is in a register, we need to check for clobbers.
1433 if (isDbgValueInDefinedReg(MI))
1434 LiveUserVar[MI->getOperand(0).getReg()] = Var;
1436 // Check the history of this variable.
1437 SmallVectorImpl<const MachineInstr *> &History = DbgValues[Var];
1438 if (History.empty()) {
1439 UserVariables.push_back(Var);
1440 // The first mention of a function argument gets the FunctionBeginSym
1441 // label, so arguments are visible when breaking at function entry.
1443 if (DV.isVariable() && DV.getTag() == dwarf::DW_TAG_arg_variable &&
1444 getDISubprogram(DV.getContext()).describes(MF->getFunction()))
1445 LabelsBeforeInsn[MI] = FunctionBeginSym;
1447 // We have seen this variable before. Try to coalesce DBG_VALUEs.
1448 const MachineInstr *Prev = History.back();
1449 if (Prev->isDebugValue()) {
1450 // Coalesce identical entries at the end of History.
1451 if (History.size() >= 2 &&
1452 Prev->isIdenticalTo(History[History.size() - 2])) {
1453 DEBUG(dbgs() << "Coalescing identical DBG_VALUE entries:\n"
1454 << "\t" << *Prev << "\t"
1455 << *History[History.size() - 2] << "\n");
1459 // Terminate old register assignments that don't reach MI;
1460 MachineFunction::const_iterator PrevMBB = Prev->getParent();
1461 if (PrevMBB != I && (!AtBlockEntry || std::next(PrevMBB) != I) &&
1462 isDbgValueInDefinedReg(Prev)) {
1463 // Previous register assignment needs to terminate at the end of
1465 MachineBasicBlock::const_iterator LastMI =
1466 PrevMBB->getLastNonDebugInstr();
1467 if (LastMI == PrevMBB->end()) {
1468 // Drop DBG_VALUE for empty range.
1469 DEBUG(dbgs() << "Dropping DBG_VALUE for empty range:\n"
1470 << "\t" << *Prev << "\n");
1472 } else if (std::next(PrevMBB) != PrevMBB->getParent()->end())
1473 // Terminate after LastMI.
1474 History.push_back(LastMI);
1478 History.push_back(MI);
1480 // Not a DBG_VALUE instruction.
1481 if (!MI->isPosition())
1482 AtBlockEntry = false;
1484 // First known non-DBG_VALUE and non-frame setup location marks
1485 // the beginning of the function body.
1486 if (!MI->getFlag(MachineInstr::FrameSetup) &&
1487 (PrologEndLoc.isUnknown() && !MI->getDebugLoc().isUnknown()))
1488 PrologEndLoc = MI->getDebugLoc();
1490 // Check if the instruction clobbers any registers with debug vars.
1491 for (const MachineOperand &MO : MI->operands()) {
1492 if (!MO.isReg() || !MO.isDef() || !MO.getReg())
1494 for (MCRegAliasIterator AI(MO.getReg(), TRI, true); AI.isValid();
1497 const MDNode *Var = LiveUserVar[Reg];
1500 // Reg is now clobbered.
1501 LiveUserVar[Reg] = nullptr;
1503 // Was MD last defined by a DBG_VALUE referring to Reg?
1504 DbgValueHistoryMap::iterator HistI = DbgValues.find(Var);
1505 if (HistI == DbgValues.end())
1507 SmallVectorImpl<const MachineInstr *> &History = HistI->second;
1508 if (History.empty())
1510 const MachineInstr *Prev = History.back();
1511 // Sanity-check: Register assignments are terminated at the end of
1513 if (!Prev->isDebugValue() || Prev->getParent() != MI->getParent())
1515 // Is the variable still in Reg?
1516 if (!isDbgValueInDefinedReg(Prev) ||
1517 Prev->getOperand(0).getReg() != Reg)
1519 // Var is clobbered. Make sure the next instruction gets a label.
1520 History.push_back(MI);
1527 for (auto &I : DbgValues) {
1528 SmallVectorImpl<const MachineInstr *> &History = I.second;
1529 if (History.empty())
1532 // Make sure the final register assignments are terminated.
1533 const MachineInstr *Prev = History.back();
1534 if (Prev->isDebugValue() && isDbgValueInDefinedReg(Prev)) {
1535 const MachineBasicBlock *PrevMBB = Prev->getParent();
1536 MachineBasicBlock::const_iterator LastMI =
1537 PrevMBB->getLastNonDebugInstr();
1538 if (LastMI == PrevMBB->end())
1539 // Drop DBG_VALUE for empty range.
1541 else if (PrevMBB != &PrevMBB->getParent()->back()) {
1542 // Terminate after LastMI.
1543 History.push_back(LastMI);
1546 // Request labels for the full history.
1547 for (const MachineInstr *MI : History) {
1548 if (MI->isDebugValue())
1549 requestLabelBeforeInsn(MI);
1551 requestLabelAfterInsn(MI);
1555 PrevInstLoc = DebugLoc();
1556 PrevLabel = FunctionBeginSym;
1558 // Record beginning of function.
1559 if (!PrologEndLoc.isUnknown()) {
1560 DebugLoc FnStartDL =
1561 PrologEndLoc.getFnDebugLoc(MF->getFunction()->getContext());
1563 FnStartDL.getLine(), FnStartDL.getCol(),
1564 FnStartDL.getScope(MF->getFunction()->getContext()),
1565 // We'd like to list the prologue as "not statements" but GDB behaves
1566 // poorly if we do that. Revisit this with caution/GDB (7.5+) testing.
1567 DWARF2_FLAG_IS_STMT);
1571 void DwarfDebug::addScopeVariable(LexicalScope *LS, DbgVariable *Var) {
1572 SmallVectorImpl<DbgVariable *> &Vars = ScopeVariables[LS];
1573 DIVariable DV = Var->getVariable();
1574 // Variables with positive arg numbers are parameters.
1575 if (unsigned ArgNum = DV.getArgNumber()) {
1576 // Keep all parameters in order at the start of the variable list to ensure
1577 // function types are correct (no out-of-order parameters)
1579 // This could be improved by only doing it for optimized builds (unoptimized
1580 // builds have the right order to begin with), searching from the back (this
1581 // would catch the unoptimized case quickly), or doing a binary search
1582 // rather than linear search.
1583 SmallVectorImpl<DbgVariable *>::iterator I = Vars.begin();
1584 while (I != Vars.end()) {
1585 unsigned CurNum = (*I)->getVariable().getArgNumber();
1586 // A local (non-parameter) variable has been found, insert immediately
1590 // A later indexed parameter has been found, insert immediately before it.
1591 if (CurNum > ArgNum)
1595 Vars.insert(I, Var);
1599 Vars.push_back(Var);
1602 // Gather and emit post-function debug information.
1603 void DwarfDebug::endFunction(const MachineFunction *MF) {
1604 // Every beginFunction(MF) call should be followed by an endFunction(MF) call,
1605 // though the beginFunction may not be called at all.
1606 // We should handle both cases.
1610 assert(CurFn == MF);
1613 if (!MMI->hasDebugInfo() || LScopes.empty()) {
1614 // If we don't have a lexical scope for this function then there will
1615 // be a hole in the range information. Keep note of this by setting the
1616 // previously used section to nullptr.
1617 PrevSection = nullptr;
1623 // Define end label for subprogram.
1624 FunctionEndSym = Asm->GetTempSymbol("func_end", Asm->getFunctionNumber());
1625 // Assumes in correct section after the entry point.
1626 Asm->OutStreamer.EmitLabel(FunctionEndSym);
1628 // Set DwarfDwarfCompileUnitID in MCContext to default value.
1629 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1631 SmallPtrSet<const MDNode *, 16> ProcessedVars;
1632 collectVariableInfo(ProcessedVars);
1634 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1635 DwarfCompileUnit &TheCU = *SPMap.lookup(FnScope->getScopeNode());
1637 // Construct abstract scopes.
1638 for (LexicalScope *AScope : LScopes.getAbstractScopesList()) {
1639 DISubprogram SP(AScope->getScopeNode());
1640 if (SP.isSubprogram()) {
1641 // Collect info for variables that were optimized out.
1642 DIArray Variables = SP.getVariables();
1643 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1644 DIVariable DV(Variables.getElement(i));
1645 if (!DV || !DV.isVariable() || !ProcessedVars.insert(DV))
1647 // Check that DbgVariable for DV wasn't created earlier, when
1648 // findAbstractVariable() was called for inlined instance of DV.
1649 LLVMContext &Ctx = DV->getContext();
1650 DIVariable CleanDV = cleanseInlinedVariable(DV, Ctx);
1651 if (AbstractVariables.lookup(CleanDV))
1653 if (LexicalScope *Scope = LScopes.findAbstractScope(DV.getContext()))
1654 addScopeVariable(Scope, new DbgVariable(DV, nullptr, this));
1657 if (ProcessedSPNodes.count(AScope->getScopeNode()) == 0)
1658 constructScopeDIE(TheCU, AScope);
1661 DIE &CurFnDIE = *constructScopeDIE(TheCU, FnScope);
1662 if (!CurFn->getTarget().Options.DisableFramePointerElim(*CurFn))
1663 TheCU.addFlag(CurFnDIE, dwarf::DW_AT_APPLE_omit_frame_ptr);
1665 // Add the range of this function to the list of ranges for the CU.
1666 RangeSpan Span(FunctionBeginSym, FunctionEndSym);
1667 TheCU.addRange(std::move(Span));
1668 PrevSection = Asm->getCurrentSection();
1672 for (auto &I : ScopeVariables)
1673 DeleteContainerPointers(I.second);
1674 ScopeVariables.clear();
1675 DeleteContainerPointers(CurrentFnArguments);
1676 UserVariables.clear();
1678 AbstractVariables.clear();
1679 LabelsBeforeInsn.clear();
1680 LabelsAfterInsn.clear();
1681 PrevLabel = nullptr;
1685 // Register a source line with debug info. Returns the unique label that was
1686 // emitted and which provides correspondence to the source line list.
1687 void DwarfDebug::recordSourceLine(unsigned Line, unsigned Col, const MDNode *S,
1692 unsigned Discriminator = 0;
1694 DIDescriptor Scope(S);
1696 if (Scope.isCompileUnit()) {
1697 DICompileUnit CU(S);
1698 Fn = CU.getFilename();
1699 Dir = CU.getDirectory();
1700 } else if (Scope.isFile()) {
1702 Fn = F.getFilename();
1703 Dir = F.getDirectory();
1704 } else if (Scope.isSubprogram()) {
1706 Fn = SP.getFilename();
1707 Dir = SP.getDirectory();
1708 } else if (Scope.isLexicalBlockFile()) {
1709 DILexicalBlockFile DBF(S);
1710 Fn = DBF.getFilename();
1711 Dir = DBF.getDirectory();
1712 } else if (Scope.isLexicalBlock()) {
1713 DILexicalBlock DB(S);
1714 Fn = DB.getFilename();
1715 Dir = DB.getDirectory();
1716 Discriminator = DB.getDiscriminator();
1718 llvm_unreachable("Unexpected scope info");
1720 unsigned CUID = Asm->OutStreamer.getContext().getDwarfCompileUnitID();
1721 Src = static_cast<DwarfCompileUnit &>(*InfoHolder.getUnits()[CUID])
1722 .getOrCreateSourceID(Fn, Dir);
1724 Asm->OutStreamer.EmitDwarfLocDirective(Src, Line, Col, Flags, 0,
1728 //===----------------------------------------------------------------------===//
1730 //===----------------------------------------------------------------------===//
1732 // Emit initial Dwarf sections with a label at the start of each one.
1733 void DwarfDebug::emitSectionLabels() {
1734 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
1736 // Dwarf sections base addresses.
1737 DwarfInfoSectionSym =
1738 emitSectionSym(Asm, TLOF.getDwarfInfoSection(), "section_info");
1739 if (useSplitDwarf())
1740 DwarfInfoDWOSectionSym =
1741 emitSectionSym(Asm, TLOF.getDwarfInfoDWOSection(), "section_info_dwo");
1742 DwarfAbbrevSectionSym =
1743 emitSectionSym(Asm, TLOF.getDwarfAbbrevSection(), "section_abbrev");
1744 if (useSplitDwarf())
1745 DwarfAbbrevDWOSectionSym = emitSectionSym(
1746 Asm, TLOF.getDwarfAbbrevDWOSection(), "section_abbrev_dwo");
1747 if (GenerateARangeSection)
1748 emitSectionSym(Asm, TLOF.getDwarfARangesSection());
1750 DwarfLineSectionSym =
1751 emitSectionSym(Asm, TLOF.getDwarfLineSection(), "section_line");
1752 if (GenerateGnuPubSections) {
1753 DwarfGnuPubNamesSectionSym =
1754 emitSectionSym(Asm, TLOF.getDwarfGnuPubNamesSection());
1755 DwarfGnuPubTypesSectionSym =
1756 emitSectionSym(Asm, TLOF.getDwarfGnuPubTypesSection());
1757 } else if (HasDwarfPubSections) {
1758 emitSectionSym(Asm, TLOF.getDwarfPubNamesSection());
1759 emitSectionSym(Asm, TLOF.getDwarfPubTypesSection());
1762 DwarfStrSectionSym =
1763 emitSectionSym(Asm, TLOF.getDwarfStrSection(), "info_string");
1764 if (useSplitDwarf()) {
1765 DwarfStrDWOSectionSym =
1766 emitSectionSym(Asm, TLOF.getDwarfStrDWOSection(), "skel_string");
1767 DwarfAddrSectionSym =
1768 emitSectionSym(Asm, TLOF.getDwarfAddrSection(), "addr_sec");
1769 DwarfDebugLocSectionSym =
1770 emitSectionSym(Asm, TLOF.getDwarfLocDWOSection(), "skel_loc");
1772 DwarfDebugLocSectionSym =
1773 emitSectionSym(Asm, TLOF.getDwarfLocSection(), "section_debug_loc");
1774 DwarfDebugRangeSectionSym =
1775 emitSectionSym(Asm, TLOF.getDwarfRangesSection(), "debug_range");
1778 // Recursively emits a debug information entry.
1779 void DwarfDebug::emitDIE(DIE &Die) {
1780 // Get the abbreviation for this DIE.
1781 const DIEAbbrev &Abbrev = Die.getAbbrev();
1783 // Emit the code (index) for the abbreviation.
1784 if (Asm->isVerbose())
1785 Asm->OutStreamer.AddComment("Abbrev [" + Twine(Abbrev.getNumber()) +
1786 "] 0x" + Twine::utohexstr(Die.getOffset()) +
1787 ":0x" + Twine::utohexstr(Die.getSize()) + " " +
1788 dwarf::TagString(Abbrev.getTag()));
1789 Asm->EmitULEB128(Abbrev.getNumber());
1791 const SmallVectorImpl<DIEValue *> &Values = Die.getValues();
1792 const SmallVectorImpl<DIEAbbrevData> &AbbrevData = Abbrev.getData();
1794 // Emit the DIE attribute values.
1795 for (unsigned i = 0, N = Values.size(); i < N; ++i) {
1796 dwarf::Attribute Attr = AbbrevData[i].getAttribute();
1797 dwarf::Form Form = AbbrevData[i].getForm();
1798 assert(Form && "Too many attributes for DIE (check abbreviation)");
1800 if (Asm->isVerbose()) {
1801 Asm->OutStreamer.AddComment(dwarf::AttributeString(Attr));
1802 if (Attr == dwarf::DW_AT_accessibility)
1803 Asm->OutStreamer.AddComment(dwarf::AccessibilityString(
1804 cast<DIEInteger>(Values[i])->getValue()));
1807 // Emit an attribute using the defined form.
1808 Values[i]->EmitValue(Asm, Form);
1811 // Emit the DIE children if any.
1812 if (Abbrev.hasChildren()) {
1813 for (auto &Child : Die.getChildren())
1816 Asm->OutStreamer.AddComment("End Of Children Mark");
1821 // Emit the debug info section.
1822 void DwarfDebug::emitDebugInfo() {
1823 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1825 Holder.emitUnits(this, DwarfAbbrevSectionSym);
1828 // Emit the abbreviation section.
1829 void DwarfDebug::emitAbbreviations() {
1830 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1832 Holder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevSection());
1835 // Emit the last address of the section and the end of the line matrix.
1836 void DwarfDebug::emitEndOfLineMatrix(unsigned SectionEnd) {
1837 // Define last address of section.
1838 Asm->OutStreamer.AddComment("Extended Op");
1841 Asm->OutStreamer.AddComment("Op size");
1842 Asm->EmitInt8(Asm->getDataLayout().getPointerSize() + 1);
1843 Asm->OutStreamer.AddComment("DW_LNE_set_address");
1844 Asm->EmitInt8(dwarf::DW_LNE_set_address);
1846 Asm->OutStreamer.AddComment("Section end label");
1848 Asm->OutStreamer.EmitSymbolValue(
1849 Asm->GetTempSymbol("section_end", SectionEnd),
1850 Asm->getDataLayout().getPointerSize());
1852 // Mark end of matrix.
1853 Asm->OutStreamer.AddComment("DW_LNE_end_sequence");
1859 // Emit visible names into a hashed accelerator table section.
1860 void DwarfDebug::emitAccelNames() {
1861 AccelNames.FinalizeTable(Asm, "Names");
1862 Asm->OutStreamer.SwitchSection(
1863 Asm->getObjFileLowering().getDwarfAccelNamesSection());
1864 MCSymbol *SectionBegin = Asm->GetTempSymbol("names_begin");
1865 Asm->OutStreamer.EmitLabel(SectionBegin);
1867 // Emit the full data.
1868 AccelNames.Emit(Asm, SectionBegin, &InfoHolder);
1871 // Emit objective C classes and categories into a hashed accelerator table
1873 void DwarfDebug::emitAccelObjC() {
1874 AccelObjC.FinalizeTable(Asm, "ObjC");
1875 Asm->OutStreamer.SwitchSection(
1876 Asm->getObjFileLowering().getDwarfAccelObjCSection());
1877 MCSymbol *SectionBegin = Asm->GetTempSymbol("objc_begin");
1878 Asm->OutStreamer.EmitLabel(SectionBegin);
1880 // Emit the full data.
1881 AccelObjC.Emit(Asm, SectionBegin, &InfoHolder);
1884 // Emit namespace dies into a hashed accelerator table.
1885 void DwarfDebug::emitAccelNamespaces() {
1886 AccelNamespace.FinalizeTable(Asm, "namespac");
1887 Asm->OutStreamer.SwitchSection(
1888 Asm->getObjFileLowering().getDwarfAccelNamespaceSection());
1889 MCSymbol *SectionBegin = Asm->GetTempSymbol("namespac_begin");
1890 Asm->OutStreamer.EmitLabel(SectionBegin);
1892 // Emit the full data.
1893 AccelNamespace.Emit(Asm, SectionBegin, &InfoHolder);
1896 // Emit type dies into a hashed accelerator table.
1897 void DwarfDebug::emitAccelTypes() {
1899 AccelTypes.FinalizeTable(Asm, "types");
1900 Asm->OutStreamer.SwitchSection(
1901 Asm->getObjFileLowering().getDwarfAccelTypesSection());
1902 MCSymbol *SectionBegin = Asm->GetTempSymbol("types_begin");
1903 Asm->OutStreamer.EmitLabel(SectionBegin);
1905 // Emit the full data.
1906 AccelTypes.Emit(Asm, SectionBegin, &InfoHolder);
1909 // Public name handling.
1910 // The format for the various pubnames:
1912 // dwarf pubnames - offset/name pairs where the offset is the offset into the CU
1913 // for the DIE that is named.
1915 // gnu pubnames - offset/index value/name tuples where the offset is the offset
1916 // into the CU and the index value is computed according to the type of value
1917 // for the DIE that is named.
1919 // For type units the offset is the offset of the skeleton DIE. For split dwarf
1920 // it's the offset within the debug_info/debug_types dwo section, however, the
1921 // reference in the pubname header doesn't change.
1923 /// computeIndexValue - Compute the gdb index value for the DIE and CU.
1924 static dwarf::PubIndexEntryDescriptor computeIndexValue(DwarfUnit *CU,
1926 dwarf::GDBIndexEntryLinkage Linkage = dwarf::GIEL_STATIC;
1928 // We could have a specification DIE that has our most of our knowledge,
1929 // look for that now.
1930 DIEValue *SpecVal = Die->findAttribute(dwarf::DW_AT_specification);
1932 DIE &SpecDIE = cast<DIEEntry>(SpecVal)->getEntry();
1933 if (SpecDIE.findAttribute(dwarf::DW_AT_external))
1934 Linkage = dwarf::GIEL_EXTERNAL;
1935 } else if (Die->findAttribute(dwarf::DW_AT_external))
1936 Linkage = dwarf::GIEL_EXTERNAL;
1938 switch (Die->getTag()) {
1939 case dwarf::DW_TAG_class_type:
1940 case dwarf::DW_TAG_structure_type:
1941 case dwarf::DW_TAG_union_type:
1942 case dwarf::DW_TAG_enumeration_type:
1943 return dwarf::PubIndexEntryDescriptor(
1944 dwarf::GIEK_TYPE, CU->getLanguage() != dwarf::DW_LANG_C_plus_plus
1945 ? dwarf::GIEL_STATIC
1946 : dwarf::GIEL_EXTERNAL);
1947 case dwarf::DW_TAG_typedef:
1948 case dwarf::DW_TAG_base_type:
1949 case dwarf::DW_TAG_subrange_type:
1950 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_TYPE, dwarf::GIEL_STATIC);
1951 case dwarf::DW_TAG_namespace:
1952 return dwarf::GIEK_TYPE;
1953 case dwarf::DW_TAG_subprogram:
1954 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_FUNCTION, Linkage);
1955 case dwarf::DW_TAG_constant:
1956 case dwarf::DW_TAG_variable:
1957 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE, Linkage);
1958 case dwarf::DW_TAG_enumerator:
1959 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE,
1960 dwarf::GIEL_STATIC);
1962 return dwarf::GIEK_NONE;
1966 /// emitDebugPubNames - Emit visible names into a debug pubnames section.
1968 void DwarfDebug::emitDebugPubNames(bool GnuStyle) {
1969 const MCSection *PSec =
1970 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubNamesSection()
1971 : Asm->getObjFileLowering().getDwarfPubNamesSection();
1973 emitDebugPubSection(GnuStyle, PSec, "Names", &DwarfUnit::getGlobalNames);
1976 void DwarfDebug::emitDebugPubSection(
1977 bool GnuStyle, const MCSection *PSec, StringRef Name,
1978 const StringMap<const DIE *> &(DwarfUnit::*Accessor)() const) {
1979 for (const auto &NU : CUMap) {
1980 DwarfCompileUnit *TheU = NU.second;
1982 const auto &Globals = (TheU->*Accessor)();
1984 if (Globals.empty())
1987 if (auto Skeleton = static_cast<DwarfCompileUnit *>(TheU->getSkeleton()))
1989 unsigned ID = TheU->getUniqueID();
1991 // Start the dwarf pubnames section.
1992 Asm->OutStreamer.SwitchSection(PSec);
1995 Asm->OutStreamer.AddComment("Length of Public " + Name + " Info");
1996 MCSymbol *BeginLabel = Asm->GetTempSymbol("pub" + Name + "_begin", ID);
1997 MCSymbol *EndLabel = Asm->GetTempSymbol("pub" + Name + "_end", ID);
1998 Asm->EmitLabelDifference(EndLabel, BeginLabel, 4);
2000 Asm->OutStreamer.EmitLabel(BeginLabel);
2002 Asm->OutStreamer.AddComment("DWARF Version");
2003 Asm->EmitInt16(dwarf::DW_PUBNAMES_VERSION);
2005 Asm->OutStreamer.AddComment("Offset of Compilation Unit Info");
2006 Asm->EmitSectionOffset(TheU->getLabelBegin(), TheU->getSectionSym());
2008 Asm->OutStreamer.AddComment("Compilation Unit Length");
2009 Asm->EmitLabelDifference(TheU->getLabelEnd(), TheU->getLabelBegin(), 4);
2011 // Emit the pubnames for this compilation unit.
2012 for (const auto &GI : Globals) {
2013 const char *Name = GI.getKeyData();
2014 const DIE *Entity = GI.second;
2016 Asm->OutStreamer.AddComment("DIE offset");
2017 Asm->EmitInt32(Entity->getOffset());
2020 dwarf::PubIndexEntryDescriptor Desc = computeIndexValue(TheU, Entity);
2021 Asm->OutStreamer.AddComment(
2022 Twine("Kind: ") + dwarf::GDBIndexEntryKindString(Desc.Kind) + ", " +
2023 dwarf::GDBIndexEntryLinkageString(Desc.Linkage));
2024 Asm->EmitInt8(Desc.toBits());
2027 Asm->OutStreamer.AddComment("External Name");
2028 Asm->OutStreamer.EmitBytes(StringRef(Name, GI.getKeyLength() + 1));
2031 Asm->OutStreamer.AddComment("End Mark");
2033 Asm->OutStreamer.EmitLabel(EndLabel);
2037 void DwarfDebug::emitDebugPubTypes(bool GnuStyle) {
2038 const MCSection *PSec =
2039 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubTypesSection()
2040 : Asm->getObjFileLowering().getDwarfPubTypesSection();
2042 emitDebugPubSection(GnuStyle, PSec, "Types", &DwarfUnit::getGlobalTypes);
2045 // Emit visible names into a debug str section.
2046 void DwarfDebug::emitDebugStr() {
2047 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
2048 Holder.emitStrings(Asm->getObjFileLowering().getDwarfStrSection());
2051 void DwarfDebug::emitDebugLocEntry(ByteStreamer &Streamer,
2052 const DebugLocEntry &Entry) {
2053 assert(Entry.getValues().size() == 1 &&
2054 "multi-value entries are not supported yet.");
2055 const DebugLocEntry::Value Value = Entry.getValues()[0];
2056 DIVariable DV(Value.getVariable());
2057 if (Value.isInt()) {
2058 DIBasicType BTy(resolve(DV.getType()));
2059 if (BTy.Verify() && (BTy.getEncoding() == dwarf::DW_ATE_signed ||
2060 BTy.getEncoding() == dwarf::DW_ATE_signed_char)) {
2061 Streamer.EmitInt8(dwarf::DW_OP_consts, "DW_OP_consts");
2062 Streamer.EmitSLEB128(Value.getInt());
2064 Streamer.EmitInt8(dwarf::DW_OP_constu, "DW_OP_constu");
2065 Streamer.EmitULEB128(Value.getInt());
2067 } else if (Value.isLocation()) {
2068 MachineLocation Loc = Value.getLoc();
2069 if (!DV.hasComplexAddress())
2071 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2073 // Complex address entry.
2074 unsigned N = DV.getNumAddrElements();
2076 if (N >= 2 && DV.getAddrElement(0) == DIBuilder::OpPlus) {
2077 if (Loc.getOffset()) {
2079 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2080 Streamer.EmitInt8(dwarf::DW_OP_deref, "DW_OP_deref");
2081 Streamer.EmitInt8(dwarf::DW_OP_plus_uconst, "DW_OP_plus_uconst");
2082 Streamer.EmitSLEB128(DV.getAddrElement(1));
2084 // If first address element is OpPlus then emit
2085 // DW_OP_breg + Offset instead of DW_OP_reg + Offset.
2086 MachineLocation TLoc(Loc.getReg(), DV.getAddrElement(1));
2087 Asm->EmitDwarfRegOp(Streamer, TLoc, DV.isIndirect());
2091 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2094 // Emit remaining complex address elements.
2095 for (; i < N; ++i) {
2096 uint64_t Element = DV.getAddrElement(i);
2097 if (Element == DIBuilder::OpPlus) {
2098 Streamer.EmitInt8(dwarf::DW_OP_plus_uconst, "DW_OP_plus_uconst");
2099 Streamer.EmitULEB128(DV.getAddrElement(++i));
2100 } else if (Element == DIBuilder::OpDeref) {
2102 Streamer.EmitInt8(dwarf::DW_OP_deref, "DW_OP_deref");
2104 llvm_unreachable("unknown Opcode found in complex address");
2108 // else ... ignore constant fp. There is not any good way to
2109 // to represent them here in dwarf.
2113 void DwarfDebug::emitDebugLocEntryLocation(const DebugLocEntry &Entry) {
2114 Asm->OutStreamer.AddComment("Loc expr size");
2115 MCSymbol *begin = Asm->OutStreamer.getContext().CreateTempSymbol();
2116 MCSymbol *end = Asm->OutStreamer.getContext().CreateTempSymbol();
2117 Asm->EmitLabelDifference(end, begin, 2);
2118 Asm->OutStreamer.EmitLabel(begin);
2120 APByteStreamer Streamer(*Asm);
2121 emitDebugLocEntry(Streamer, Entry);
2123 Asm->OutStreamer.EmitLabel(end);
2126 // Emit locations into the debug loc section.
2127 void DwarfDebug::emitDebugLoc() {
2128 // Start the dwarf loc section.
2129 Asm->OutStreamer.SwitchSection(
2130 Asm->getObjFileLowering().getDwarfLocSection());
2131 unsigned char Size = Asm->getDataLayout().getPointerSize();
2132 for (const auto &DebugLoc : DotDebugLocEntries) {
2133 Asm->OutStreamer.EmitLabel(DebugLoc.Label);
2134 for (const auto &Entry : DebugLoc.List) {
2135 // Set up the range. This range is relative to the entry point of the
2136 // compile unit. This is a hard coded 0 for low_pc when we're emitting
2137 // ranges, or the DW_AT_low_pc on the compile unit otherwise.
2138 const DwarfCompileUnit *CU = Entry.getCU();
2139 if (CU->getRanges().size() == 1) {
2140 // Grab the begin symbol from the first range as our base.
2141 const MCSymbol *Base = CU->getRanges()[0].getStart();
2142 Asm->EmitLabelDifference(Entry.getBeginSym(), Base, Size);
2143 Asm->EmitLabelDifference(Entry.getEndSym(), Base, Size);
2145 Asm->OutStreamer.EmitSymbolValue(Entry.getBeginSym(), Size);
2146 Asm->OutStreamer.EmitSymbolValue(Entry.getEndSym(), Size);
2149 emitDebugLocEntryLocation(Entry);
2151 Asm->OutStreamer.EmitIntValue(0, Size);
2152 Asm->OutStreamer.EmitIntValue(0, Size);
2156 void DwarfDebug::emitDebugLocDWO() {
2157 Asm->OutStreamer.SwitchSection(
2158 Asm->getObjFileLowering().getDwarfLocDWOSection());
2159 for (const auto &DebugLoc : DotDebugLocEntries) {
2160 Asm->OutStreamer.EmitLabel(DebugLoc.Label);
2161 for (const auto &Entry : DebugLoc.List) {
2162 // Just always use start_length for now - at least that's one address
2163 // rather than two. We could get fancier and try to, say, reuse an
2164 // address we know we've emitted elsewhere (the start of the function?
2165 // The start of the CU or CU subrange that encloses this range?)
2166 Asm->EmitInt8(dwarf::DW_LLE_start_length_entry);
2167 unsigned idx = AddrPool.getIndex(Entry.getBeginSym());
2168 Asm->EmitULEB128(idx);
2169 Asm->EmitLabelDifference(Entry.getEndSym(), Entry.getBeginSym(), 4);
2171 emitDebugLocEntryLocation(Entry);
2173 Asm->EmitInt8(dwarf::DW_LLE_end_of_list_entry);
2178 const MCSymbol *Start, *End;
2181 // Emit a debug aranges section, containing a CU lookup for any
2182 // address we can tie back to a CU.
2183 void DwarfDebug::emitDebugARanges() {
2184 // Start the dwarf aranges section.
2185 Asm->OutStreamer.SwitchSection(
2186 Asm->getObjFileLowering().getDwarfARangesSection());
2188 typedef DenseMap<DwarfCompileUnit *, std::vector<ArangeSpan> > SpansType;
2192 // Build a list of sections used.
2193 std::vector<const MCSection *> Sections;
2194 for (const auto &it : SectionMap) {
2195 const MCSection *Section = it.first;
2196 Sections.push_back(Section);
2199 // Sort the sections into order.
2200 // This is only done to ensure consistent output order across different runs.
2201 std::sort(Sections.begin(), Sections.end(), SectionSort);
2203 // Build a set of address spans, sorted by CU.
2204 for (const MCSection *Section : Sections) {
2205 SmallVector<SymbolCU, 8> &List = SectionMap[Section];
2206 if (List.size() < 2)
2209 // Sort the symbols by offset within the section.
2210 std::sort(List.begin(), List.end(),
2211 [&](const SymbolCU &A, const SymbolCU &B) {
2212 unsigned IA = A.Sym ? Asm->OutStreamer.GetSymbolOrder(A.Sym) : 0;
2213 unsigned IB = B.Sym ? Asm->OutStreamer.GetSymbolOrder(B.Sym) : 0;
2215 // Symbols with no order assigned should be placed at the end.
2216 // (e.g. section end labels)
2224 // If we have no section (e.g. common), just write out
2225 // individual spans for each symbol.
2227 for (const SymbolCU &Cur : List) {
2229 Span.Start = Cur.Sym;
2232 Spans[Cur.CU].push_back(Span);
2235 // Build spans between each label.
2236 const MCSymbol *StartSym = List[0].Sym;
2237 for (size_t n = 1, e = List.size(); n < e; n++) {
2238 const SymbolCU &Prev = List[n - 1];
2239 const SymbolCU &Cur = List[n];
2241 // Try and build the longest span we can within the same CU.
2242 if (Cur.CU != Prev.CU) {
2244 Span.Start = StartSym;
2246 Spans[Prev.CU].push_back(Span);
2253 unsigned PtrSize = Asm->getDataLayout().getPointerSize();
2255 // Build a list of CUs used.
2256 std::vector<DwarfCompileUnit *> CUs;
2257 for (const auto &it : Spans) {
2258 DwarfCompileUnit *CU = it.first;
2262 // Sort the CU list (again, to ensure consistent output order).
2263 std::sort(CUs.begin(), CUs.end(), [](const DwarfUnit *A, const DwarfUnit *B) {
2264 return A->getUniqueID() < B->getUniqueID();
2267 // Emit an arange table for each CU we used.
2268 for (DwarfCompileUnit *CU : CUs) {
2269 std::vector<ArangeSpan> &List = Spans[CU];
2271 // Emit size of content not including length itself.
2272 unsigned ContentSize =
2273 sizeof(int16_t) + // DWARF ARange version number
2274 sizeof(int32_t) + // Offset of CU in the .debug_info section
2275 sizeof(int8_t) + // Pointer Size (in bytes)
2276 sizeof(int8_t); // Segment Size (in bytes)
2278 unsigned TupleSize = PtrSize * 2;
2280 // 7.20 in the Dwarf specs requires the table to be aligned to a tuple.
2282 OffsetToAlignment(sizeof(int32_t) + ContentSize, TupleSize);
2284 ContentSize += Padding;
2285 ContentSize += (List.size() + 1) * TupleSize;
2287 // For each compile unit, write the list of spans it covers.
2288 Asm->OutStreamer.AddComment("Length of ARange Set");
2289 Asm->EmitInt32(ContentSize);
2290 Asm->OutStreamer.AddComment("DWARF Arange version number");
2291 Asm->EmitInt16(dwarf::DW_ARANGES_VERSION);
2292 Asm->OutStreamer.AddComment("Offset Into Debug Info Section");
2293 Asm->EmitSectionOffset(CU->getLocalLabelBegin(), CU->getLocalSectionSym());
2294 Asm->OutStreamer.AddComment("Address Size (in bytes)");
2295 Asm->EmitInt8(PtrSize);
2296 Asm->OutStreamer.AddComment("Segment Size (in bytes)");
2299 Asm->OutStreamer.EmitFill(Padding, 0xff);
2301 for (const ArangeSpan &Span : List) {
2302 Asm->EmitLabelReference(Span.Start, PtrSize);
2304 // Calculate the size as being from the span start to it's end.
2306 Asm->EmitLabelDifference(Span.End, Span.Start, PtrSize);
2308 // For symbols without an end marker (e.g. common), we
2309 // write a single arange entry containing just that one symbol.
2310 uint64_t Size = SymSize[Span.Start];
2314 Asm->OutStreamer.EmitIntValue(Size, PtrSize);
2318 Asm->OutStreamer.AddComment("ARange terminator");
2319 Asm->OutStreamer.EmitIntValue(0, PtrSize);
2320 Asm->OutStreamer.EmitIntValue(0, PtrSize);
2324 // Emit visible names into a debug ranges section.
2325 void DwarfDebug::emitDebugRanges() {
2326 // Start the dwarf ranges section.
2327 Asm->OutStreamer.SwitchSection(
2328 Asm->getObjFileLowering().getDwarfRangesSection());
2330 // Size for our labels.
2331 unsigned char Size = Asm->getDataLayout().getPointerSize();
2333 // Grab the specific ranges for the compile units in the module.
2334 for (const auto &I : CUMap) {
2335 DwarfCompileUnit *TheCU = I.second;
2337 // Emit a symbol so we can find the beginning of our ranges.
2338 Asm->OutStreamer.EmitLabel(TheCU->getLabelRange());
2340 // Iterate over the misc ranges for the compile units in the module.
2341 for (const RangeSpanList &List : TheCU->getRangeLists()) {
2342 // Emit our symbol so we can find the beginning of the range.
2343 Asm->OutStreamer.EmitLabel(List.getSym());
2345 for (const RangeSpan &Range : List.getRanges()) {
2346 const MCSymbol *Begin = Range.getStart();
2347 const MCSymbol *End = Range.getEnd();
2348 assert(Begin && "Range without a begin symbol?");
2349 assert(End && "Range without an end symbol?");
2350 if (TheCU->getRanges().size() == 1) {
2351 // Grab the begin symbol from the first range as our base.
2352 const MCSymbol *Base = TheCU->getRanges()[0].getStart();
2353 Asm->EmitLabelDifference(Begin, Base, Size);
2354 Asm->EmitLabelDifference(End, Base, Size);
2356 Asm->OutStreamer.EmitSymbolValue(Begin, Size);
2357 Asm->OutStreamer.EmitSymbolValue(End, Size);
2361 // And terminate the list with two 0 values.
2362 Asm->OutStreamer.EmitIntValue(0, Size);
2363 Asm->OutStreamer.EmitIntValue(0, Size);
2366 // Now emit a range for the CU itself.
2367 if (TheCU->getRanges().size() > 1) {
2368 Asm->OutStreamer.EmitLabel(
2369 Asm->GetTempSymbol("cu_ranges", TheCU->getUniqueID()));
2370 for (const RangeSpan &Range : TheCU->getRanges()) {
2371 const MCSymbol *Begin = Range.getStart();
2372 const MCSymbol *End = Range.getEnd();
2373 assert(Begin && "Range without a begin symbol?");
2374 assert(End && "Range without an end symbol?");
2375 Asm->OutStreamer.EmitSymbolValue(Begin, Size);
2376 Asm->OutStreamer.EmitSymbolValue(End, Size);
2378 // And terminate the list with two 0 values.
2379 Asm->OutStreamer.EmitIntValue(0, Size);
2380 Asm->OutStreamer.EmitIntValue(0, Size);
2385 // DWARF5 Experimental Separate Dwarf emitters.
2387 void DwarfDebug::initSkeletonUnit(const DwarfUnit &U, DIE &Die,
2388 std::unique_ptr<DwarfUnit> NewU) {
2389 NewU->addLocalString(Die, dwarf::DW_AT_GNU_dwo_name,
2390 U.getCUNode().getSplitDebugFilename());
2392 if (!CompilationDir.empty())
2393 NewU->addLocalString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
2395 addGnuPubAttributes(*NewU, Die);
2397 SkeletonHolder.addUnit(std::move(NewU));
2400 // This DIE has the following attributes: DW_AT_comp_dir, DW_AT_stmt_list,
2401 // DW_AT_low_pc, DW_AT_high_pc, DW_AT_ranges, DW_AT_dwo_name, DW_AT_dwo_id,
2402 // DW_AT_addr_base, DW_AT_ranges_base.
2403 DwarfCompileUnit &DwarfDebug::constructSkeletonCU(const DwarfCompileUnit &CU) {
2405 DIE *Die = new DIE(dwarf::DW_TAG_compile_unit);
2406 auto OwnedUnit = make_unique<DwarfCompileUnit>(
2407 CU.getUniqueID(), Die, CU.getCUNode(), Asm, this, &SkeletonHolder);
2408 DwarfCompileUnit &NewCU = *OwnedUnit;
2409 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoSection(),
2410 DwarfInfoSectionSym);
2412 NewCU.initStmtList(DwarfLineSectionSym);
2414 initSkeletonUnit(CU, *Die, std::move(OwnedUnit));
2419 // This DIE has the following attributes: DW_AT_comp_dir, DW_AT_dwo_name,
2421 DwarfTypeUnit &DwarfDebug::constructSkeletonTU(DwarfTypeUnit &TU) {
2422 DwarfCompileUnit &CU = static_cast<DwarfCompileUnit &>(
2423 *SkeletonHolder.getUnits()[TU.getCU().getUniqueID()]);
2425 DIE *Die = new DIE(dwarf::DW_TAG_type_unit);
2426 auto OwnedUnit = make_unique<DwarfTypeUnit>(TU.getUniqueID(), Die, CU, Asm,
2427 this, &SkeletonHolder);
2428 DwarfTypeUnit &NewTU = *OwnedUnit;
2429 NewTU.setTypeSignature(TU.getTypeSignature());
2430 NewTU.setType(nullptr);
2432 Asm->getObjFileLowering().getDwarfTypesSection(TU.getTypeSignature()));
2434 initSkeletonUnit(TU, *Die, std::move(OwnedUnit));
2438 // Emit the .debug_info.dwo section for separated dwarf. This contains the
2439 // compile units that would normally be in debug_info.
2440 void DwarfDebug::emitDebugInfoDWO() {
2441 assert(useSplitDwarf() && "No split dwarf debug info?");
2442 // Don't pass an abbrev symbol, using a constant zero instead so as not to
2443 // emit relocations into the dwo file.
2444 InfoHolder.emitUnits(this, /* AbbrevSymbol */nullptr);
2447 // Emit the .debug_abbrev.dwo section for separated dwarf. This contains the
2448 // abbreviations for the .debug_info.dwo section.
2449 void DwarfDebug::emitDebugAbbrevDWO() {
2450 assert(useSplitDwarf() && "No split dwarf?");
2451 InfoHolder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevDWOSection());
2454 void DwarfDebug::emitDebugLineDWO() {
2455 assert(useSplitDwarf() && "No split dwarf?");
2456 Asm->OutStreamer.SwitchSection(
2457 Asm->getObjFileLowering().getDwarfLineDWOSection());
2458 SplitTypeUnitFileTable.Emit(Asm->OutStreamer);
2461 // Emit the .debug_str.dwo section for separated dwarf. This contains the
2462 // string section and is identical in format to traditional .debug_str
2464 void DwarfDebug::emitDebugStrDWO() {
2465 assert(useSplitDwarf() && "No split dwarf?");
2466 const MCSection *OffSec =
2467 Asm->getObjFileLowering().getDwarfStrOffDWOSection();
2468 const MCSymbol *StrSym = DwarfStrSectionSym;
2469 InfoHolder.emitStrings(Asm->getObjFileLowering().getDwarfStrDWOSection(),
2473 MCDwarfDwoLineTable *DwarfDebug::getDwoLineTable(const DwarfCompileUnit &CU) {
2474 if (!useSplitDwarf())
2477 SplitTypeUnitFileTable.setCompilationDir(CU.getCUNode().getDirectory());
2478 return &SplitTypeUnitFileTable;
2481 static uint64_t makeTypeSignature(StringRef Identifier) {
2483 Hash.update(Identifier);
2484 // ... take the least significant 8 bytes and return those. Our MD5
2485 // implementation always returns its results in little endian, swap bytes
2487 MD5::MD5Result Result;
2489 return *reinterpret_cast<support::ulittle64_t *>(Result + 8);
2492 void DwarfDebug::addDwarfTypeUnitType(DwarfCompileUnit &CU,
2493 StringRef Identifier, DIE &RefDie,
2494 DICompositeType CTy) {
2495 // Fast path if we're building some type units and one has already used the
2496 // address pool we know we're going to throw away all this work anyway, so
2497 // don't bother building dependent types.
2498 if (!TypeUnitsUnderConstruction.empty() && AddrPool.hasBeenUsed())
2501 const DwarfTypeUnit *&TU = DwarfTypeUnits[CTy];
2503 CU.addDIETypeSignature(RefDie, *TU);
2507 bool TopLevelType = TypeUnitsUnderConstruction.empty();
2508 AddrPool.resetUsedFlag();
2510 DIE *UnitDie = new DIE(dwarf::DW_TAG_type_unit);
2512 make_unique<DwarfTypeUnit>(InfoHolder.getUnits().size(), UnitDie, CU, Asm,
2513 this, &InfoHolder, getDwoLineTable(CU));
2514 DwarfTypeUnit &NewTU = *OwnedUnit;
2516 TypeUnitsUnderConstruction.push_back(std::make_pair(std::move(OwnedUnit), CTy));
2518 NewTU.addUInt(*UnitDie, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
2521 uint64_t Signature = makeTypeSignature(Identifier);
2522 NewTU.setTypeSignature(Signature);
2524 if (!useSplitDwarf())
2525 CU.applyStmtList(*UnitDie);
2529 ? Asm->getObjFileLowering().getDwarfTypesDWOSection(Signature)
2530 : Asm->getObjFileLowering().getDwarfTypesSection(Signature));
2532 NewTU.setType(NewTU.createTypeDIE(CTy));
2535 auto TypeUnitsToAdd = std::move(TypeUnitsUnderConstruction);
2536 TypeUnitsUnderConstruction.clear();
2538 // Types referencing entries in the address table cannot be placed in type
2540 if (AddrPool.hasBeenUsed()) {
2542 // Remove all the types built while building this type.
2543 // This is pessimistic as some of these types might not be dependent on
2544 // the type that used an address.
2545 for (const auto &TU : TypeUnitsToAdd)
2546 DwarfTypeUnits.erase(TU.second);
2548 // Construct this type in the CU directly.
2549 // This is inefficient because all the dependent types will be rebuilt
2550 // from scratch, including building them in type units, discovering that
2551 // they depend on addresses, throwing them out and rebuilding them.
2552 CU.constructTypeDIE(RefDie, CTy);
2556 // If the type wasn't dependent on fission addresses, finish adding the type
2557 // and all its dependent types.
2558 for (auto &TU : TypeUnitsToAdd) {
2559 if (useSplitDwarf())
2560 TU.first->setSkeleton(constructSkeletonTU(*TU.first));
2561 InfoHolder.addUnit(std::move(TU.first));
2564 CU.addDIETypeSignature(RefDie, NewTU);
2567 void DwarfDebug::attachLowHighPC(DwarfCompileUnit &Unit, DIE &D,
2568 MCSymbol *Begin, MCSymbol *End) {
2569 Unit.addLabelAddress(D, dwarf::DW_AT_low_pc, Begin);
2570 if (DwarfVersion < 4)
2571 Unit.addLabelAddress(D, dwarf::DW_AT_high_pc, End);
2573 Unit.addLabelDelta(D, dwarf::DW_AT_high_pc, End, Begin);
2576 // Accelerator table mutators - add each name along with its companion
2577 // DIE to the proper table while ensuring that the name that we're going
2578 // to reference is in the string table. We do this since the names we
2579 // add may not only be identical to the names in the DIE.
2580 void DwarfDebug::addAccelName(StringRef Name, const DIE &Die) {
2581 if (!useDwarfAccelTables())
2583 AccelNames.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2587 void DwarfDebug::addAccelObjC(StringRef Name, const DIE &Die) {
2588 if (!useDwarfAccelTables())
2590 AccelObjC.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2594 void DwarfDebug::addAccelNamespace(StringRef Name, const DIE &Die) {
2595 if (!useDwarfAccelTables())
2597 AccelNamespace.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2601 void DwarfDebug::addAccelType(StringRef Name, const DIE &Die, char Flags) {
2602 if (!useDwarfAccelTables())
2604 AccelTypes.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),