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 #define DEBUG_TYPE "dwarfdebug"
15 #include "ByteStreamer.h"
16 #include "DwarfDebug.h"
19 #include "DwarfAccelTable.h"
20 #include "DwarfUnit.h"
21 #include "llvm/ADT/STLExtras.h"
22 #include "llvm/ADT/Statistic.h"
23 #include "llvm/ADT/StringExtras.h"
24 #include "llvm/ADT/Triple.h"
25 #include "llvm/CodeGen/MachineFunction.h"
26 #include "llvm/CodeGen/MachineModuleInfo.h"
27 #include "llvm/IR/Constants.h"
28 #include "llvm/IR/DIBuilder.h"
29 #include "llvm/IR/DataLayout.h"
30 #include "llvm/IR/DebugInfo.h"
31 #include "llvm/IR/Instructions.h"
32 #include "llvm/IR/Module.h"
33 #include "llvm/IR/ValueHandle.h"
34 #include "llvm/MC/MCAsmInfo.h"
35 #include "llvm/MC/MCSection.h"
36 #include "llvm/MC/MCStreamer.h"
37 #include "llvm/MC/MCSymbol.h"
38 #include "llvm/Support/CommandLine.h"
39 #include "llvm/Support/Debug.h"
40 #include "llvm/Support/Dwarf.h"
41 #include "llvm/Support/ErrorHandling.h"
42 #include "llvm/Support/FormattedStream.h"
43 #include "llvm/Support/LEB128.h"
44 #include "llvm/Support/MD5.h"
45 #include "llvm/Support/Path.h"
46 #include "llvm/Support/Timer.h"
47 #include "llvm/Target/TargetFrameLowering.h"
48 #include "llvm/Target/TargetLoweringObjectFile.h"
49 #include "llvm/Target/TargetMachine.h"
50 #include "llvm/Target/TargetOptions.h"
51 #include "llvm/Target/TargetRegisterInfo.h"
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 //===----------------------------------------------------------------------===//
112 /// resolve - Look in the DwarfDebug map for the MDNode that
113 /// corresponds to the reference.
114 template <typename T> T DbgVariable::resolve(DIRef<T> Ref) const {
115 return DD->resolve(Ref);
118 bool DbgVariable::isBlockByrefVariable() const {
119 assert(Var.isVariable() && "Invalid complex DbgVariable!");
120 return Var.isBlockByrefVariable(DD->getTypeIdentifierMap());
124 DIType DbgVariable::getType() const {
125 DIType Ty = Var.getType().resolve(DD->getTypeIdentifierMap());
126 // FIXME: isBlockByrefVariable should be reformulated in terms of complex
127 // addresses instead.
128 if (Var.isBlockByrefVariable(DD->getTypeIdentifierMap())) {
129 /* Byref variables, in Blocks, are declared by the programmer as
130 "SomeType VarName;", but the compiler creates a
131 __Block_byref_x_VarName struct, and gives the variable VarName
132 either the struct, or a pointer to the struct, as its type. This
133 is necessary for various behind-the-scenes things the compiler
134 needs to do with by-reference variables in blocks.
136 However, as far as the original *programmer* is concerned, the
137 variable should still have type 'SomeType', as originally declared.
139 The following function dives into the __Block_byref_x_VarName
140 struct to find the original type of the variable. This will be
141 passed back to the code generating the type for the Debug
142 Information Entry for the variable 'VarName'. 'VarName' will then
143 have the original type 'SomeType' in its debug information.
145 The original type 'SomeType' will be the type of the field named
146 'VarName' inside the __Block_byref_x_VarName struct.
148 NOTE: In order for this to not completely fail on the debugger
149 side, the Debug Information Entry for the variable VarName needs to
150 have a DW_AT_location that tells the debugger how to unwind through
151 the pointers and __Block_byref_x_VarName struct to find the actual
152 value of the variable. The function addBlockByrefType does this. */
154 uint16_t tag = Ty.getTag();
156 if (tag == dwarf::DW_TAG_pointer_type)
157 subType = resolve(DIDerivedType(Ty).getTypeDerivedFrom());
159 DIArray Elements = DICompositeType(subType).getTypeArray();
160 for (unsigned i = 0, N = Elements.getNumElements(); i < N; ++i) {
161 DIDerivedType DT(Elements.getElement(i));
162 if (getName() == DT.getName())
163 return (resolve(DT.getTypeDerivedFrom()));
169 } // end llvm namespace
171 /// Return Dwarf Version by checking module flags.
172 static unsigned getDwarfVersionFromModule(const Module *M) {
173 Value *Val = M->getModuleFlag("Dwarf Version");
175 return dwarf::DWARF_VERSION;
176 return cast<ConstantInt>(Val)->getZExtValue();
179 DwarfDebug::DwarfDebug(AsmPrinter *A, Module *M)
180 : Asm(A), MMI(Asm->MMI), FirstCU(0), PrevLabel(NULL), GlobalRangeCount(0),
181 InfoHolder(A, "info_string", DIEValueAllocator),
182 UsedNonDefaultText(false),
183 SkeletonHolder(A, "skel_string", DIEValueAllocator) {
185 DwarfInfoSectionSym = DwarfAbbrevSectionSym = DwarfStrSectionSym = 0;
186 DwarfDebugRangeSectionSym = DwarfDebugLocSectionSym = DwarfLineSectionSym = 0;
187 DwarfAddrSectionSym = 0;
188 DwarfAbbrevDWOSectionSym = DwarfStrDWOSectionSym = 0;
189 FunctionBeginSym = FunctionEndSym = 0;
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
214 : getDwarfVersionFromModule(MMI->getModule());
217 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
222 // Switch to the specified MCSection and emit an assembler
223 // temporary label to it if SymbolStem is specified.
224 static MCSymbol *emitSectionSym(AsmPrinter *Asm, const MCSection *Section,
225 const char *SymbolStem = 0) {
226 Asm->OutStreamer.SwitchSection(Section);
230 MCSymbol *TmpSym = Asm->GetTempSymbol(SymbolStem);
231 Asm->OutStreamer.EmitLabel(TmpSym);
235 DwarfFile::~DwarfFile() {
236 for (DwarfUnit *DU : CUs)
240 MCSymbol *DwarfFile::getStringPoolSym() {
241 return Asm->GetTempSymbol(StringPref);
244 MCSymbol *DwarfFile::getStringPoolEntry(StringRef Str) {
245 std::pair<MCSymbol *, unsigned> &Entry =
246 StringPool.GetOrCreateValue(Str).getValue();
250 Entry.second = NextStringPoolNumber++;
251 return Entry.first = Asm->GetTempSymbol(StringPref, Entry.second);
254 unsigned DwarfFile::getStringPoolIndex(StringRef Str) {
255 std::pair<MCSymbol *, unsigned> &Entry =
256 StringPool.GetOrCreateValue(Str).getValue();
260 Entry.second = NextStringPoolNumber++;
261 Entry.first = Asm->GetTempSymbol(StringPref, Entry.second);
265 unsigned DwarfFile::getAddrPoolIndex(const MCSymbol *Sym, bool TLS) {
266 std::pair<AddrPool::iterator, bool> P = AddressPool.insert(
267 std::make_pair(Sym, AddressPoolEntry(NextAddrPoolNumber, TLS)));
269 ++NextAddrPoolNumber;
270 return P.first->second.Number;
273 // Define a unique number for the abbreviation.
275 void DwarfFile::assignAbbrevNumber(DIEAbbrev &Abbrev) {
276 // Check the set for priors.
277 DIEAbbrev *InSet = AbbreviationsSet.GetOrInsertNode(&Abbrev);
279 // If it's newly added.
280 if (InSet == &Abbrev) {
281 // Add to abbreviation list.
282 Abbreviations.push_back(&Abbrev);
284 // Assign the vector position + 1 as its number.
285 Abbrev.setNumber(Abbreviations.size());
287 // Assign existing abbreviation number.
288 Abbrev.setNumber(InSet->getNumber());
292 static bool isObjCClass(StringRef Name) {
293 return Name.startswith("+") || Name.startswith("-");
296 static bool hasObjCCategory(StringRef Name) {
297 if (!isObjCClass(Name))
300 return Name.find(") ") != StringRef::npos;
303 static void getObjCClassCategory(StringRef In, StringRef &Class,
304 StringRef &Category) {
305 if (!hasObjCCategory(In)) {
306 Class = In.slice(In.find('[') + 1, In.find(' '));
311 Class = In.slice(In.find('[') + 1, In.find('('));
312 Category = In.slice(In.find('[') + 1, In.find(' '));
316 static StringRef getObjCMethodName(StringRef In) {
317 return In.slice(In.find(' ') + 1, In.find(']'));
320 // Helper for sorting sections into a stable output order.
321 static bool SectionSort(const MCSection *A, const MCSection *B) {
322 std::string LA = (A ? A->getLabelBeginName() : "");
323 std::string LB = (B ? B->getLabelBeginName() : "");
327 // Add the various names to the Dwarf accelerator table names.
328 // TODO: Determine whether or not we should add names for programs
329 // that do not have a DW_AT_name or DW_AT_linkage_name field - this
330 // is only slightly different than the lookup of non-standard ObjC names.
331 static void addSubprogramNames(DwarfUnit *TheU, DISubprogram SP, DIE *Die) {
332 if (!SP.isDefinition())
334 TheU->addAccelName(SP.getName(), Die);
336 // If the linkage name is different than the name, go ahead and output
337 // that as well into the name table.
338 if (SP.getLinkageName() != "" && SP.getName() != SP.getLinkageName())
339 TheU->addAccelName(SP.getLinkageName(), Die);
341 // If this is an Objective-C selector name add it to the ObjC accelerator
343 if (isObjCClass(SP.getName())) {
344 StringRef Class, Category;
345 getObjCClassCategory(SP.getName(), Class, Category);
346 TheU->addAccelObjC(Class, Die);
348 TheU->addAccelObjC(Category, Die);
349 // Also add the base method name to the name table.
350 TheU->addAccelName(getObjCMethodName(SP.getName()), Die);
354 /// isSubprogramContext - Return true if Context is either a subprogram
355 /// or another context nested inside a subprogram.
356 bool DwarfDebug::isSubprogramContext(const MDNode *Context) {
359 DIDescriptor D(Context);
360 if (D.isSubprogram())
363 return isSubprogramContext(resolve(DIType(Context).getContext()));
367 // Find DIE for the given subprogram and attach appropriate DW_AT_low_pc
368 // and DW_AT_high_pc attributes. If there are global variables in this
369 // scope then create and insert DIEs for these variables.
370 DIE *DwarfDebug::updateSubprogramScopeDIE(DwarfCompileUnit *SPCU,
372 DIE *SPDie = SPCU->getDIE(SP);
374 assert(SPDie && "Unable to find subprogram DIE!");
376 // If we're updating an abstract DIE, then we will be adding the children and
377 // object pointer later on. But what we don't want to do is process the
378 // concrete DIE twice.
379 if (DIE *AbsSPDIE = AbstractSPDies.lookup(SP)) {
380 // Pick up abstract subprogram DIE.
382 SPCU->createAndAddDIE(dwarf::DW_TAG_subprogram, *SPCU->getUnitDie());
383 SPCU->addDIEEntry(SPDie, dwarf::DW_AT_abstract_origin, AbsSPDIE);
385 DISubprogram SPDecl = SP.getFunctionDeclaration();
386 if (!SPDecl.isSubprogram()) {
387 // There is not any need to generate specification DIE for a function
388 // defined at compile unit level. If a function is defined inside another
389 // function then gdb prefers the definition at top level and but does not
390 // expect specification DIE in parent function. So avoid creating
391 // specification DIE for a function defined inside a function.
392 DIScope SPContext = resolve(SP.getContext());
393 if (SP.isDefinition() && !SPContext.isCompileUnit() &&
394 !SPContext.isFile() && !isSubprogramContext(SPContext)) {
395 SPCU->addFlag(SPDie, dwarf::DW_AT_declaration);
398 DICompositeType SPTy = SP.getType();
399 DIArray Args = SPTy.getTypeArray();
400 uint16_t SPTag = SPTy.getTag();
401 if (SPTag == dwarf::DW_TAG_subroutine_type)
402 SPCU->constructSubprogramArguments(*SPDie, Args);
403 DIE *SPDeclDie = SPDie;
404 SPDie = SPCU->createAndAddDIE(dwarf::DW_TAG_subprogram,
405 *SPCU->getUnitDie());
406 SPCU->addDIEEntry(SPDie, dwarf::DW_AT_specification, SPDeclDie);
411 attachLowHighPC(SPCU, SPDie, FunctionBeginSym, FunctionEndSym);
413 const TargetRegisterInfo *RI = Asm->TM.getRegisterInfo();
414 MachineLocation Location(RI->getFrameRegister(*Asm->MF));
415 SPCU->addAddress(SPDie, dwarf::DW_AT_frame_base, Location);
417 // Add name to the name table, we do this here because we're guaranteed
418 // to have concrete versions of our DW_TAG_subprogram nodes.
419 addSubprogramNames(SPCU, SP, SPDie);
424 /// Check whether we should create a DIE for the given Scope, return true
425 /// if we don't create a DIE (the corresponding DIE is null).
426 bool DwarfDebug::isLexicalScopeDIENull(LexicalScope *Scope) {
427 if (Scope->isAbstractScope())
430 // We don't create a DIE if there is no Range.
431 const SmallVectorImpl<InsnRange> &Ranges = Scope->getRanges();
435 if (Ranges.size() > 1)
438 // We don't create a DIE if we have a single Range and the end label
440 SmallVectorImpl<InsnRange>::const_iterator RI = Ranges.begin();
441 MCSymbol *End = getLabelAfterInsn(RI->second);
445 static void addSectionLabel(AsmPrinter *Asm, DwarfUnit *U, DIE *D,
446 dwarf::Attribute A, const MCSymbol *L,
447 const MCSymbol *Sec) {
448 if (Asm->MAI->doesDwarfUseRelocationsAcrossSections())
449 U->addSectionLabel(D, A, L);
451 U->addSectionDelta(D, A, L, Sec);
454 void DwarfDebug::addScopeRangeList(DwarfCompileUnit *TheCU, DIE *ScopeDIE,
455 const SmallVectorImpl<InsnRange> &Range) {
456 // Emit offset in .debug_range as a relocatable label. emitDIE will handle
457 // emitting it appropriately.
458 MCSymbol *RangeSym = Asm->GetTempSymbol("debug_ranges", GlobalRangeCount++);
459 addSectionLabel(Asm, TheCU, ScopeDIE, dwarf::DW_AT_ranges, RangeSym,
460 DwarfDebugRangeSectionSym);
462 RangeSpanList List(RangeSym);
463 for (const InsnRange &R : Range) {
464 RangeSpan Span(getLabelBeforeInsn(R.first), getLabelAfterInsn(R.second));
465 List.addRange(std::move(Span));
468 // Add the range list to the set of ranges to be emitted.
469 TheCU->addRangeList(std::move(List));
472 // Construct new DW_TAG_lexical_block for this scope and attach
473 // DW_AT_low_pc/DW_AT_high_pc labels.
474 DIE *DwarfDebug::constructLexicalScopeDIE(DwarfCompileUnit *TheCU,
475 LexicalScope *Scope) {
476 if (isLexicalScopeDIENull(Scope))
479 DIE *ScopeDIE = new DIE(dwarf::DW_TAG_lexical_block);
480 if (Scope->isAbstractScope())
483 const SmallVectorImpl<InsnRange> &ScopeRanges = Scope->getRanges();
485 // If we have multiple ranges, emit them into the range section.
486 if (ScopeRanges.size() > 1) {
487 addScopeRangeList(TheCU, ScopeDIE, ScopeRanges);
491 // Construct the address range for this DIE.
492 SmallVectorImpl<InsnRange>::const_iterator RI = ScopeRanges.begin();
493 MCSymbol *Start = getLabelBeforeInsn(RI->first);
494 MCSymbol *End = getLabelAfterInsn(RI->second);
495 assert(End && "End label should not be null!");
497 assert(Start->isDefined() && "Invalid starting label for an inlined scope!");
498 assert(End->isDefined() && "Invalid end label for an inlined scope!");
500 attachLowHighPC(TheCU, ScopeDIE, Start, End);
505 // This scope represents inlined body of a function. Construct DIE to
506 // represent this concrete inlined copy of the function.
507 DIE *DwarfDebug::constructInlinedScopeDIE(DwarfCompileUnit *TheCU,
508 LexicalScope *Scope) {
509 const SmallVectorImpl<InsnRange> &ScopeRanges = Scope->getRanges();
510 assert(!ScopeRanges.empty() &&
511 "LexicalScope does not have instruction markers!");
513 if (!Scope->getScopeNode())
515 DIScope DS(Scope->getScopeNode());
516 DISubprogram InlinedSP = getDISubprogram(DS);
517 DIE *OriginDIE = TheCU->getDIE(InlinedSP);
519 DEBUG(dbgs() << "Unable to find original DIE for an inlined subprogram.");
523 DIE *ScopeDIE = new DIE(dwarf::DW_TAG_inlined_subroutine);
524 TheCU->addDIEEntry(ScopeDIE, dwarf::DW_AT_abstract_origin, OriginDIE);
526 // If we have multiple ranges, emit them into the range section.
527 if (ScopeRanges.size() > 1)
528 addScopeRangeList(TheCU, ScopeDIE, ScopeRanges);
530 SmallVectorImpl<InsnRange>::const_iterator RI = ScopeRanges.begin();
531 MCSymbol *StartLabel = getLabelBeforeInsn(RI->first);
532 MCSymbol *EndLabel = getLabelAfterInsn(RI->second);
534 if (StartLabel == 0 || EndLabel == 0)
535 llvm_unreachable("Unexpected Start and End labels for an inlined scope!");
537 assert(StartLabel->isDefined() &&
538 "Invalid starting label for an inlined scope!");
539 assert(EndLabel->isDefined() && "Invalid end label for an inlined scope!");
541 attachLowHighPC(TheCU, ScopeDIE, StartLabel, EndLabel);
544 InlinedSubprogramDIEs.insert(OriginDIE);
546 // Add the call site information to the DIE.
547 DILocation DL(Scope->getInlinedAt());
549 ScopeDIE, dwarf::DW_AT_call_file, None,
550 TheCU->getOrCreateSourceID(DL.getFilename(), DL.getDirectory()));
551 TheCU->addUInt(ScopeDIE, dwarf::DW_AT_call_line, None, DL.getLineNumber());
553 // Add name to the name table, we do this here because we're guaranteed
554 // to have concrete versions of our DW_TAG_inlined_subprogram nodes.
555 addSubprogramNames(TheCU, InlinedSP, ScopeDIE);
560 DIE *DwarfDebug::createScopeChildrenDIE(DwarfCompileUnit *TheCU,
562 SmallVectorImpl<DIE *> &Children) {
563 DIE *ObjectPointer = NULL;
565 // Collect arguments for current function.
566 if (LScopes.isCurrentFunctionScope(Scope)) {
567 for (DbgVariable *ArgDV : CurrentFnArguments)
570 TheCU->constructVariableDIE(*ArgDV, Scope->isAbstractScope())) {
571 Children.push_back(Arg);
572 if (ArgDV->isObjectPointer())
576 // If this is a variadic function, add an unspecified parameter.
577 DISubprogram SP(Scope->getScopeNode());
578 DIArray FnArgs = SP.getType().getTypeArray();
579 if (FnArgs.getElement(FnArgs.getNumElements() - 1)
580 .isUnspecifiedParameter()) {
581 DIE *Ellipsis = new DIE(dwarf::DW_TAG_unspecified_parameters);
582 Children.push_back(Ellipsis);
586 // Collect lexical scope children first.
587 for (DbgVariable *DV : ScopeVariables.lookup(Scope))
588 if (DIE *Variable = TheCU->constructVariableDIE(*DV,
589 Scope->isAbstractScope())) {
590 Children.push_back(Variable);
591 if (DV->isObjectPointer())
592 ObjectPointer = Variable;
594 for (LexicalScope *LS : Scope->getChildren())
595 if (DIE *Nested = constructScopeDIE(TheCU, LS))
596 Children.push_back(Nested);
597 return ObjectPointer;
600 // Construct a DIE for this scope.
601 DIE *DwarfDebug::constructScopeDIE(DwarfCompileUnit *TheCU,
602 LexicalScope *Scope) {
603 if (!Scope || !Scope->getScopeNode())
606 // Unique scope where applicable.
607 DIScope DS(resolve(DIScope(Scope->getScopeNode()).getRef()));
609 SmallVector<DIE *, 8> Children;
610 DIE *ObjectPointer = NULL;
611 bool ChildrenCreated = false;
613 // We try to create the scope DIE first, then the children DIEs. This will
614 // avoid creating un-used children then removing them later when we find out
615 // the scope DIE is null.
616 DIE *ScopeDIE = NULL;
617 if (Scope->getInlinedAt())
618 ScopeDIE = constructInlinedScopeDIE(TheCU, Scope);
619 else if (DS.isSubprogram()) {
620 ProcessedSPNodes.insert(DS);
621 if (Scope->isAbstractScope()) {
622 ScopeDIE = TheCU->getDIE(DS);
623 // Note down abstract DIE.
625 AbstractSPDies.insert(std::make_pair(DS, ScopeDIE));
627 ScopeDIE = updateSubprogramScopeDIE(TheCU, DISubprogram(DS));
629 // Early exit when we know the scope DIE is going to be null.
630 if (isLexicalScopeDIENull(Scope))
633 // We create children here when we know the scope DIE is not going to be
634 // null and the children will be added to the scope DIE.
635 ObjectPointer = createScopeChildrenDIE(TheCU, Scope, Children);
636 ChildrenCreated = true;
638 // There is no need to emit empty lexical block DIE.
639 std::pair<ImportedEntityMap::const_iterator,
640 ImportedEntityMap::const_iterator> Range =
642 ScopesWithImportedEntities.begin(),
643 ScopesWithImportedEntities.end(),
644 std::pair<const MDNode *, const MDNode *>(DS, (const MDNode *)0),
646 if (Children.empty() && Range.first == Range.second)
648 ScopeDIE = constructLexicalScopeDIE(TheCU, Scope);
649 assert(ScopeDIE && "Scope DIE should not be null.");
650 for (ImportedEntityMap::const_iterator i = Range.first; i != Range.second;
652 constructImportedEntityDIE(TheCU, i->second, ScopeDIE);
656 assert(Children.empty() &&
657 "We create children only when the scope DIE is not null.");
660 if (!ChildrenCreated)
661 // We create children when the scope DIE is not null.
662 ObjectPointer = createScopeChildrenDIE(TheCU, Scope, Children);
665 for (DIE *I : Children)
666 ScopeDIE->addChild(I);
668 if (DS.isSubprogram() && ObjectPointer != NULL)
669 TheCU->addDIEEntry(ScopeDIE, dwarf::DW_AT_object_pointer, ObjectPointer);
674 void DwarfDebug::addGnuPubAttributes(DwarfUnit *U, DIE *D) const {
675 if (!GenerateGnuPubSections)
678 U->addFlag(D, dwarf::DW_AT_GNU_pubnames);
681 // Create new DwarfCompileUnit for the given metadata node with tag
682 // DW_TAG_compile_unit.
683 DwarfCompileUnit *DwarfDebug::constructDwarfCompileUnit(DICompileUnit DIUnit) {
684 StringRef FN = DIUnit.getFilename();
685 CompilationDir = DIUnit.getDirectory();
687 DIE *Die = new DIE(dwarf::DW_TAG_compile_unit);
688 DwarfCompileUnit *NewCU = new DwarfCompileUnit(
689 InfoHolder.getUnits().size(), Die, DIUnit, Asm, this, &InfoHolder);
690 InfoHolder.addUnit(NewCU);
691 if (!Asm->OutStreamer.hasRawTextSupport() || SingleCU)
692 Asm->OutStreamer.getContext().setMCLineTableCompilationDir(
693 NewCU->getUniqueID(), CompilationDir);
695 NewCU->addString(Die, dwarf::DW_AT_producer, DIUnit.getProducer());
696 NewCU->addUInt(Die, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
697 DIUnit.getLanguage());
698 NewCU->addString(Die, dwarf::DW_AT_name, FN);
700 if (!useSplitDwarf()) {
701 NewCU->initStmtList(DwarfLineSectionSym);
703 // If we're using split dwarf the compilation dir is going to be in the
704 // skeleton CU and so we don't need to duplicate it here.
705 if (!CompilationDir.empty())
706 NewCU->addString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
708 addGnuPubAttributes(NewCU, Die);
711 if (DIUnit.isOptimized())
712 NewCU->addFlag(Die, dwarf::DW_AT_APPLE_optimized);
714 StringRef Flags = DIUnit.getFlags();
716 NewCU->addString(Die, dwarf::DW_AT_APPLE_flags, Flags);
718 if (unsigned RVer = DIUnit.getRunTimeVersion())
719 NewCU->addUInt(Die, dwarf::DW_AT_APPLE_major_runtime_vers,
720 dwarf::DW_FORM_data1, RVer);
725 if (useSplitDwarf()) {
726 NewCU->initSection(Asm->getObjFileLowering().getDwarfInfoDWOSection(),
727 DwarfInfoDWOSectionSym);
728 NewCU->setSkeleton(constructSkeletonCU(NewCU));
730 NewCU->initSection(Asm->getObjFileLowering().getDwarfInfoSection(),
731 DwarfInfoSectionSym);
733 CUMap.insert(std::make_pair(DIUnit, NewCU));
734 CUDieMap.insert(std::make_pair(Die, NewCU));
738 // Construct subprogram DIE.
739 void DwarfDebug::constructSubprogramDIE(DwarfCompileUnit *TheCU,
741 // FIXME: We should only call this routine once, however, during LTO if a
742 // program is defined in multiple CUs we could end up calling it out of
743 // beginModule as we walk the CUs.
745 DwarfCompileUnit *&CURef = SPMap[N];
751 if (!SP.isDefinition())
752 // This is a method declaration which will be handled while constructing
756 DIE *SubprogramDie = TheCU->getOrCreateSubprogramDIE(SP);
758 // Expose as a global name.
759 TheCU->addGlobalName(SP.getName(), SubprogramDie, resolve(SP.getContext()));
762 void DwarfDebug::constructImportedEntityDIE(DwarfCompileUnit *TheCU,
764 DIImportedEntity Module(N);
765 assert(Module.Verify());
766 if (DIE *D = TheCU->getOrCreateContextDIE(Module.getContext()))
767 constructImportedEntityDIE(TheCU, Module, D);
770 void DwarfDebug::constructImportedEntityDIE(DwarfCompileUnit *TheCU,
771 const MDNode *N, DIE *Context) {
772 DIImportedEntity Module(N);
773 assert(Module.Verify());
774 return constructImportedEntityDIE(TheCU, Module, Context);
777 void DwarfDebug::constructImportedEntityDIE(DwarfCompileUnit *TheCU,
778 const DIImportedEntity &Module,
780 assert(Module.Verify() &&
781 "Use one of the MDNode * overloads to handle invalid metadata");
782 assert(Context && "Should always have a context for an imported_module");
783 DIE *IMDie = new DIE(Module.getTag());
784 TheCU->insertDIE(Module, IMDie);
786 DIDescriptor Entity = Module.getEntity();
787 if (Entity.isNameSpace())
788 EntityDie = TheCU->getOrCreateNameSpace(DINameSpace(Entity));
789 else if (Entity.isSubprogram())
790 EntityDie = TheCU->getOrCreateSubprogramDIE(DISubprogram(Entity));
791 else if (Entity.isType())
792 EntityDie = TheCU->getOrCreateTypeDIE(DIType(Entity));
794 EntityDie = TheCU->getDIE(Entity);
795 TheCU->addSourceLine(IMDie, Module.getLineNumber(),
796 Module.getContext().getFilename(),
797 Module.getContext().getDirectory());
798 TheCU->addDIEEntry(IMDie, dwarf::DW_AT_import, EntityDie);
799 StringRef Name = Module.getName();
801 TheCU->addString(IMDie, dwarf::DW_AT_name, Name);
802 Context->addChild(IMDie);
805 // Emit all Dwarf sections that should come prior to the content. Create
806 // global DIEs and emit initial debug info sections. This is invoked by
807 // the target AsmPrinter.
808 void DwarfDebug::beginModule() {
809 if (DisableDebugInfoPrinting)
812 const Module *M = MMI->getModule();
814 // If module has named metadata anchors then use them, otherwise scan the
815 // module using debug info finder to collect debug info.
816 NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
819 TypeIdentifierMap = generateDITypeIdentifierMap(CU_Nodes);
821 // Emit initial sections so we can reference labels later.
824 SingleCU = CU_Nodes->getNumOperands() == 1;
826 for (MDNode *N : CU_Nodes->operands()) {
827 DICompileUnit CUNode(N);
828 DwarfCompileUnit *CU = constructDwarfCompileUnit(CUNode);
829 DIArray ImportedEntities = CUNode.getImportedEntities();
830 for (unsigned i = 0, e = ImportedEntities.getNumElements(); i != e; ++i)
831 ScopesWithImportedEntities.push_back(std::make_pair(
832 DIImportedEntity(ImportedEntities.getElement(i)).getContext(),
833 ImportedEntities.getElement(i)));
834 std::sort(ScopesWithImportedEntities.begin(),
835 ScopesWithImportedEntities.end(), less_first());
836 DIArray GVs = CUNode.getGlobalVariables();
837 for (unsigned i = 0, e = GVs.getNumElements(); i != e; ++i)
838 CU->createGlobalVariableDIE(DIGlobalVariable(GVs.getElement(i)));
839 DIArray SPs = CUNode.getSubprograms();
840 for (unsigned i = 0, e = SPs.getNumElements(); i != e; ++i)
841 constructSubprogramDIE(CU, SPs.getElement(i));
842 DIArray EnumTypes = CUNode.getEnumTypes();
843 for (unsigned i = 0, e = EnumTypes.getNumElements(); i != e; ++i)
844 CU->getOrCreateTypeDIE(EnumTypes.getElement(i));
845 DIArray RetainedTypes = CUNode.getRetainedTypes();
846 for (unsigned i = 0, e = RetainedTypes.getNumElements(); i != e; ++i) {
847 DIType Ty(RetainedTypes.getElement(i));
848 // The retained types array by design contains pointers to
849 // MDNodes rather than DIRefs. Unique them here.
850 DIType UniqueTy(resolve(Ty.getRef()));
851 CU->getOrCreateTypeDIE(UniqueTy);
853 // Emit imported_modules last so that the relevant context is already
855 for (unsigned i = 0, e = ImportedEntities.getNumElements(); i != e; ++i)
856 constructImportedEntityDIE(CU, ImportedEntities.getElement(i));
859 // Tell MMI that we have debug info.
860 MMI->setDebugInfoAvailability(true);
862 // Prime section data.
863 SectionMap[Asm->getObjFileLowering().getTextSection()];
866 // Attach DW_AT_inline attribute with inlined subprogram DIEs.
867 void DwarfDebug::computeInlinedDIEs() {
868 // Attach DW_AT_inline attribute with inlined subprogram DIEs.
869 for (DIE *ISP : InlinedSubprogramDIEs)
870 FirstCU->addUInt(ISP, dwarf::DW_AT_inline, None, dwarf::DW_INL_inlined);
872 for (const auto &AI : AbstractSPDies) {
873 DIE *ISP = AI.second;
874 if (InlinedSubprogramDIEs.count(ISP))
876 FirstCU->addUInt(ISP, dwarf::DW_AT_inline, None, dwarf::DW_INL_inlined);
880 // Collect info for variables that were optimized out.
881 void DwarfDebug::collectDeadVariables() {
882 const Module *M = MMI->getModule();
884 if (NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu")) {
885 for (MDNode *N : CU_Nodes->operands()) {
886 DICompileUnit TheCU(N);
887 DIArray Subprograms = TheCU.getSubprograms();
888 for (unsigned i = 0, e = Subprograms.getNumElements(); i != e; ++i) {
889 DISubprogram SP(Subprograms.getElement(i));
890 if (ProcessedSPNodes.count(SP) != 0)
892 if (!SP.isSubprogram())
894 if (!SP.isDefinition())
896 DIArray Variables = SP.getVariables();
897 if (Variables.getNumElements() == 0)
900 // Construct subprogram DIE and add variables DIEs.
901 DwarfCompileUnit *SPCU =
902 static_cast<DwarfCompileUnit *>(CUMap.lookup(TheCU));
903 assert(SPCU && "Unable to find Compile Unit!");
904 // FIXME: See the comment in constructSubprogramDIE about duplicate
906 constructSubprogramDIE(SPCU, SP);
907 DIE *SPDIE = SPCU->getDIE(SP);
908 for (unsigned vi = 0, ve = Variables.getNumElements(); vi != ve; ++vi) {
909 DIVariable DV(Variables.getElement(vi));
910 if (!DV.isVariable())
912 DbgVariable NewVar(DV, NULL, this);
913 if (DIE *VariableDIE = SPCU->constructVariableDIE(NewVar, false))
914 SPDIE->addChild(VariableDIE);
921 void DwarfDebug::finalizeModuleInfo() {
922 // Collect info for variables that were optimized out.
923 collectDeadVariables();
925 // Attach DW_AT_inline attribute with inlined subprogram DIEs.
926 computeInlinedDIEs();
928 // Handle anything that needs to be done on a per-unit basis after
929 // all other generation.
930 for (DwarfUnit *TheU : getUnits()) {
931 // Emit DW_AT_containing_type attribute to connect types with their
932 // vtable holding type.
933 TheU->constructContainingTypeDIEs();
935 // Add CU specific attributes if we need to add any.
936 if (TheU->getUnitDie()->getTag() == dwarf::DW_TAG_compile_unit) {
937 // If we're splitting the dwarf out now that we've got the entire
938 // CU then add the dwo id to it.
939 DwarfCompileUnit *SkCU =
940 static_cast<DwarfCompileUnit *>(TheU->getSkeleton());
941 if (useSplitDwarf()) {
942 // Emit a unique identifier for this CU.
943 uint64_t ID = DIEHash(Asm).computeCUSignature(*TheU->getUnitDie());
944 TheU->addUInt(TheU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
945 dwarf::DW_FORM_data8, ID);
946 SkCU->addUInt(SkCU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
947 dwarf::DW_FORM_data8, ID);
950 // If we have code split among multiple sections or non-contiguous
951 // ranges of code then emit a DW_AT_ranges attribute on the unit that will
952 // remain in the .o file, otherwise add a DW_AT_low_pc.
953 // FIXME: We should use ranges allow reordering of code ala
954 // .subsections_via_symbols in mach-o. This would mean turning on
955 // ranges for all subprogram DIEs for mach-o.
956 DwarfCompileUnit *U = SkCU ? SkCU : static_cast<DwarfCompileUnit *>(TheU);
957 unsigned NumRanges = TheU->getRanges().size();
960 addSectionLabel(Asm, U, U->getUnitDie(), dwarf::DW_AT_ranges,
961 Asm->GetTempSymbol("cu_ranges", U->getUniqueID()),
962 DwarfDebugRangeSectionSym);
964 // A DW_AT_low_pc attribute may also be specified in combination with
965 // DW_AT_ranges to specify the default base address for use in
966 // location lists (see Section 2.6.2) and range lists (see Section
968 U->addUInt(U->getUnitDie(), dwarf::DW_AT_low_pc, dwarf::DW_FORM_addr,
971 RangeSpan &Range = TheU->getRanges().back();
972 U->addLocalLabelAddress(U->getUnitDie(), dwarf::DW_AT_low_pc,
974 U->addLabelDelta(U->getUnitDie(), dwarf::DW_AT_high_pc,
975 Range.getEnd(), Range.getStart());
981 // Compute DIE offsets and sizes.
982 InfoHolder.computeSizeAndOffsets();
984 SkeletonHolder.computeSizeAndOffsets();
987 void DwarfDebug::endSections() {
988 // Filter labels by section.
989 for (const SymbolCU &SCU : ArangeLabels) {
990 if (SCU.Sym->isInSection()) {
991 // Make a note of this symbol and it's section.
992 const MCSection *Section = &SCU.Sym->getSection();
993 if (!Section->getKind().isMetadata())
994 SectionMap[Section].push_back(SCU);
996 // Some symbols (e.g. common/bss on mach-o) can have no section but still
997 // appear in the output. This sucks as we rely on sections to build
998 // arange spans. We can do it without, but it's icky.
999 SectionMap[NULL].push_back(SCU);
1003 // Build a list of sections used.
1004 std::vector<const MCSection *> Sections;
1005 for (const auto &it : SectionMap) {
1006 const MCSection *Section = it.first;
1007 Sections.push_back(Section);
1010 // Sort the sections into order.
1011 // This is only done to ensure consistent output order across different runs.
1012 std::sort(Sections.begin(), Sections.end(), SectionSort);
1014 // Add terminating symbols for each section.
1015 for (unsigned ID = 0, E = Sections.size(); ID != E; ID++) {
1016 const MCSection *Section = Sections[ID];
1017 MCSymbol *Sym = NULL;
1020 // We can't call MCSection::getLabelEndName, as it's only safe to do so
1021 // if we know the section name up-front. For user-created sections, the
1022 // resulting label may not be valid to use as a label. (section names can
1023 // use a greater set of characters on some systems)
1024 Sym = Asm->GetTempSymbol("debug_end", ID);
1025 Asm->OutStreamer.SwitchSection(Section);
1026 Asm->OutStreamer.EmitLabel(Sym);
1029 // Insert a final terminator.
1030 SectionMap[Section].push_back(SymbolCU(NULL, Sym));
1034 // Emit all Dwarf sections that should come after the content.
1035 void DwarfDebug::endModule() {
1042 // End any existing sections.
1043 // TODO: Does this need to happen?
1046 // Finalize the debug info for the module.
1047 finalizeModuleInfo();
1051 // Emit all the DIEs into a debug info section.
1054 // Corresponding abbreviations into a abbrev section.
1055 emitAbbreviations();
1057 // Emit info into a debug loc section.
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 InfoHolder.emitAddresses(Asm->getObjFileLowering().getDwarfAddrSection());
1076 // Emit info into the dwarf accelerator table sections.
1077 if (useDwarfAccelTables()) {
1080 emitAccelNamespaces();
1084 // Emit the pubnames and pubtypes sections if requested.
1085 if (HasDwarfPubSections) {
1086 emitDebugPubNames(GenerateGnuPubSections);
1087 emitDebugPubTypes(GenerateGnuPubSections);
1093 // Reset these for the next Module if we have one.
1097 // Find abstract variable, if any, associated with Var.
1098 DbgVariable *DwarfDebug::findAbstractVariable(DIVariable &DV,
1099 DebugLoc ScopeLoc) {
1100 LLVMContext &Ctx = DV->getContext();
1101 // More then one inlined variable corresponds to one abstract variable.
1102 DIVariable Var = cleanseInlinedVariable(DV, Ctx);
1103 DbgVariable *AbsDbgVariable = AbstractVariables.lookup(Var);
1105 return AbsDbgVariable;
1107 LexicalScope *Scope = LScopes.findAbstractScope(ScopeLoc.getScope(Ctx));
1111 AbsDbgVariable = new DbgVariable(Var, NULL, this);
1112 addScopeVariable(Scope, AbsDbgVariable);
1113 AbstractVariables[Var] = AbsDbgVariable;
1114 return AbsDbgVariable;
1117 // If Var is a current function argument then add it to CurrentFnArguments list.
1118 bool DwarfDebug::addCurrentFnArgument(DbgVariable *Var, LexicalScope *Scope) {
1119 if (!LScopes.isCurrentFunctionScope(Scope))
1121 DIVariable DV = Var->getVariable();
1122 if (DV.getTag() != dwarf::DW_TAG_arg_variable)
1124 unsigned ArgNo = DV.getArgNumber();
1128 size_t Size = CurrentFnArguments.size();
1130 CurrentFnArguments.resize(CurFn->getFunction()->arg_size());
1131 // llvm::Function argument size is not good indicator of how many
1132 // arguments does the function have at source level.
1134 CurrentFnArguments.resize(ArgNo * 2);
1135 CurrentFnArguments[ArgNo - 1] = Var;
1139 // Collect variable information from side table maintained by MMI.
1140 void DwarfDebug::collectVariableInfoFromMMITable(
1141 SmallPtrSet<const MDNode *, 16> &Processed) {
1142 for (const auto &VI : MMI->getVariableDbgInfo()) {
1145 Processed.insert(VI.Var);
1146 DIVariable DV(VI.Var);
1147 LexicalScope *Scope = LScopes.findLexicalScope(VI.Loc);
1149 // If variable scope is not found then skip this variable.
1153 DbgVariable *AbsDbgVariable = findAbstractVariable(DV, VI.Loc);
1154 DbgVariable *RegVar = new DbgVariable(DV, AbsDbgVariable, this);
1155 RegVar->setFrameIndex(VI.Slot);
1156 if (!addCurrentFnArgument(RegVar, Scope))
1157 addScopeVariable(Scope, RegVar);
1159 AbsDbgVariable->setFrameIndex(VI.Slot);
1163 // Return true if debug value, encoded by DBG_VALUE instruction, is in a
1165 static bool isDbgValueInDefinedReg(const MachineInstr *MI) {
1166 assert(MI->isDebugValue() && "Invalid DBG_VALUE machine instruction!");
1167 return MI->getNumOperands() == 3 && MI->getOperand(0).isReg() &&
1168 MI->getOperand(0).getReg() &&
1169 (MI->getOperand(1).isImm() ||
1170 (MI->getOperand(1).isReg() && MI->getOperand(1).getReg() == 0U));
1173 // Get .debug_loc entry for the instruction range starting at MI.
1174 static DebugLocEntry getDebugLocEntry(AsmPrinter *Asm,
1175 const MCSymbol *FLabel,
1176 const MCSymbol *SLabel,
1177 const MachineInstr *MI) {
1178 const MDNode *Var = MI->getOperand(MI->getNumOperands() - 1).getMetadata();
1180 assert(MI->getNumOperands() == 3);
1181 if (MI->getOperand(0).isReg()) {
1182 MachineLocation MLoc;
1183 // If the second operand is an immediate, this is a
1184 // register-indirect address.
1185 if (!MI->getOperand(1).isImm())
1186 MLoc.set(MI->getOperand(0).getReg());
1188 MLoc.set(MI->getOperand(0).getReg(), MI->getOperand(1).getImm());
1189 return DebugLocEntry(FLabel, SLabel, MLoc, Var);
1191 if (MI->getOperand(0).isImm())
1192 return DebugLocEntry(FLabel, SLabel, MI->getOperand(0).getImm());
1193 if (MI->getOperand(0).isFPImm())
1194 return DebugLocEntry(FLabel, SLabel, MI->getOperand(0).getFPImm());
1195 if (MI->getOperand(0).isCImm())
1196 return DebugLocEntry(FLabel, SLabel, MI->getOperand(0).getCImm());
1198 llvm_unreachable("Unexpected 3 operand DBG_VALUE instruction!");
1201 // Find variables for each lexical scope.
1203 DwarfDebug::collectVariableInfo(SmallPtrSet<const MDNode *, 16> &Processed) {
1205 // Grab the variable info that was squirreled away in the MMI side-table.
1206 collectVariableInfoFromMMITable(Processed);
1208 for (const MDNode *Var : UserVariables) {
1209 if (Processed.count(Var))
1212 // History contains relevant DBG_VALUE instructions for Var and instructions
1214 SmallVectorImpl<const MachineInstr *> &History = DbgValues[Var];
1215 if (History.empty())
1217 const MachineInstr *MInsn = History.front();
1220 LexicalScope *Scope = NULL;
1221 if (DV.getTag() == dwarf::DW_TAG_arg_variable &&
1222 DISubprogram(DV.getContext()).describes(CurFn->getFunction()))
1223 Scope = LScopes.getCurrentFunctionScope();
1224 else if (MDNode *IA = DV.getInlinedAt())
1225 Scope = LScopes.findInlinedScope(DebugLoc::getFromDILocation(IA));
1227 Scope = LScopes.findLexicalScope(cast<MDNode>(DV->getOperand(1)));
1228 // If variable scope is not found then skip this variable.
1232 Processed.insert(DV);
1233 assert(MInsn->isDebugValue() && "History must begin with debug value");
1234 DbgVariable *AbsVar = findAbstractVariable(DV, MInsn->getDebugLoc());
1235 DbgVariable *RegVar = new DbgVariable(DV, AbsVar, this);
1236 if (!addCurrentFnArgument(RegVar, Scope))
1237 addScopeVariable(Scope, RegVar);
1239 AbsVar->setMInsn(MInsn);
1241 // Simplify ranges that are fully coalesced.
1242 if (History.size() <= 1 ||
1243 (History.size() == 2 && MInsn->isIdenticalTo(History.back()))) {
1244 RegVar->setMInsn(MInsn);
1248 // Handle multiple DBG_VALUE instructions describing one variable.
1249 RegVar->setDotDebugLocOffset(DotDebugLocEntries.size());
1251 for (SmallVectorImpl<const MachineInstr *>::const_iterator
1252 HI = History.begin(),
1255 const MachineInstr *Begin = *HI;
1256 assert(Begin->isDebugValue() && "Invalid History entry");
1258 // Check if DBG_VALUE is truncating a range.
1259 if (Begin->getNumOperands() > 1 && Begin->getOperand(0).isReg() &&
1260 !Begin->getOperand(0).getReg())
1263 // Compute the range for a register location.
1264 const MCSymbol *FLabel = getLabelBeforeInsn(Begin);
1265 const MCSymbol *SLabel = 0;
1268 // If Begin is the last instruction in History then its value is valid
1269 // until the end of the function.
1270 SLabel = FunctionEndSym;
1272 const MachineInstr *End = HI[1];
1273 DEBUG(dbgs() << "DotDebugLoc Pair:\n"
1274 << "\t" << *Begin << "\t" << *End << "\n");
1275 if (End->isDebugValue())
1276 SLabel = getLabelBeforeInsn(End);
1278 // End is a normal instruction clobbering the range.
1279 SLabel = getLabelAfterInsn(End);
1280 assert(SLabel && "Forgot label after clobber instruction");
1285 // The value is valid until the next DBG_VALUE or clobber.
1286 DotDebugLocEntries.push_back(
1287 getDebugLocEntry(Asm, FLabel, SLabel, Begin));
1289 DotDebugLocEntries.push_back(DebugLocEntry());
1292 // Collect info for variables that were optimized out.
1293 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1294 DIArray Variables = DISubprogram(FnScope->getScopeNode()).getVariables();
1295 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1296 DIVariable DV(Variables.getElement(i));
1297 if (!DV || !DV.isVariable() || !Processed.insert(DV))
1299 if (LexicalScope *Scope = LScopes.findLexicalScope(DV.getContext()))
1300 addScopeVariable(Scope, new DbgVariable(DV, NULL, this));
1304 // Return Label preceding the instruction.
1305 MCSymbol *DwarfDebug::getLabelBeforeInsn(const MachineInstr *MI) {
1306 MCSymbol *Label = LabelsBeforeInsn.lookup(MI);
1307 assert(Label && "Didn't insert label before instruction");
1311 // Return Label immediately following the instruction.
1312 MCSymbol *DwarfDebug::getLabelAfterInsn(const MachineInstr *MI) {
1313 return LabelsAfterInsn.lookup(MI);
1316 // Process beginning of an instruction.
1317 void DwarfDebug::beginInstruction(const MachineInstr *MI) {
1320 // Check if source location changes, but ignore DBG_VALUE locations.
1321 if (!MI->isDebugValue()) {
1322 DebugLoc DL = MI->getDebugLoc();
1323 if (DL != PrevInstLoc && (!DL.isUnknown() || UnknownLocations)) {
1326 if (DL == PrologEndLoc) {
1327 Flags |= DWARF2_FLAG_PROLOGUE_END;
1328 PrologEndLoc = DebugLoc();
1330 if (PrologEndLoc.isUnknown())
1331 Flags |= DWARF2_FLAG_IS_STMT;
1333 if (!DL.isUnknown()) {
1334 const MDNode *Scope = DL.getScope(Asm->MF->getFunction()->getContext());
1335 recordSourceLine(DL.getLine(), DL.getCol(), Scope, Flags);
1337 recordSourceLine(0, 0, 0, 0);
1341 // Insert labels where requested.
1342 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1343 LabelsBeforeInsn.find(MI);
1346 if (I == LabelsBeforeInsn.end())
1349 // Label already assigned.
1354 PrevLabel = MMI->getContext().CreateTempSymbol();
1355 Asm->OutStreamer.EmitLabel(PrevLabel);
1357 I->second = PrevLabel;
1360 // Process end of an instruction.
1361 void DwarfDebug::endInstruction() {
1363 // Don't create a new label after DBG_VALUE instructions.
1364 // They don't generate code.
1365 if (!CurMI->isDebugValue())
1368 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1369 LabelsAfterInsn.find(CurMI);
1373 if (I == LabelsAfterInsn.end())
1376 // Label already assigned.
1380 // We need a label after this instruction.
1382 PrevLabel = MMI->getContext().CreateTempSymbol();
1383 Asm->OutStreamer.EmitLabel(PrevLabel);
1385 I->second = PrevLabel;
1388 // Each LexicalScope has first instruction and last instruction to mark
1389 // beginning and end of a scope respectively. Create an inverse map that list
1390 // scopes starts (and ends) with an instruction. One instruction may start (or
1391 // end) multiple scopes. Ignore scopes that are not reachable.
1392 void DwarfDebug::identifyScopeMarkers() {
1393 SmallVector<LexicalScope *, 4> WorkList;
1394 WorkList.push_back(LScopes.getCurrentFunctionScope());
1395 while (!WorkList.empty()) {
1396 LexicalScope *S = WorkList.pop_back_val();
1398 const SmallVectorImpl<LexicalScope *> &Children = S->getChildren();
1399 if (!Children.empty())
1400 WorkList.append(Children.begin(), Children.end());
1402 if (S->isAbstractScope())
1405 for (const InsnRange &R : S->getRanges()) {
1406 assert(R.first && "InsnRange does not have first instruction!");
1407 assert(R.second && "InsnRange does not have second instruction!");
1408 requestLabelBeforeInsn(R.first);
1409 requestLabelAfterInsn(R.second);
1414 // Gather pre-function debug information. Assumes being called immediately
1415 // after the function entry point has been emitted.
1416 void DwarfDebug::beginFunction(const MachineFunction *MF) {
1419 // If there's no debug info for the function we're not going to do anything.
1420 if (!MMI->hasDebugInfo())
1423 // Grab the lexical scopes for the function, if we don't have any of those
1424 // then we're not going to be able to do anything.
1425 LScopes.initialize(*MF);
1426 if (LScopes.empty())
1429 assert(UserVariables.empty() && DbgValues.empty() && "Maps weren't cleaned");
1431 // Make sure that each lexical scope will have a begin/end label.
1432 identifyScopeMarkers();
1434 // Set DwarfDwarfCompileUnitID in MCContext to the Compile Unit this function
1435 // belongs to so that we add to the correct per-cu line table in the
1437 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1438 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1439 assert(TheCU && "Unable to find compile unit!");
1440 if (Asm->OutStreamer.hasRawTextSupport())
1441 // Use a single line table if we are generating assembly.
1442 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1444 Asm->OutStreamer.getContext().setDwarfCompileUnitID(TheCU->getUniqueID());
1446 // Emit a label for the function so that we have a beginning address.
1447 FunctionBeginSym = Asm->GetTempSymbol("func_begin", Asm->getFunctionNumber());
1448 // Assumes in correct section after the entry point.
1449 Asm->OutStreamer.EmitLabel(FunctionBeginSym);
1451 const TargetRegisterInfo *TRI = Asm->TM.getRegisterInfo();
1452 // LiveUserVar - Map physreg numbers to the MDNode they contain.
1453 std::vector<const MDNode *> LiveUserVar(TRI->getNumRegs());
1455 for (MachineFunction::const_iterator I = MF->begin(), E = MF->end(); I != E;
1457 bool AtBlockEntry = true;
1458 for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end();
1460 const MachineInstr *MI = II;
1462 if (MI->isDebugValue()) {
1463 assert(MI->getNumOperands() > 1 && "Invalid machine instruction!");
1465 // Keep track of user variables.
1467 MI->getOperand(MI->getNumOperands() - 1).getMetadata();
1469 // Variable is in a register, we need to check for clobbers.
1470 if (isDbgValueInDefinedReg(MI))
1471 LiveUserVar[MI->getOperand(0).getReg()] = Var;
1473 // Check the history of this variable.
1474 SmallVectorImpl<const MachineInstr *> &History = DbgValues[Var];
1475 if (History.empty()) {
1476 UserVariables.push_back(Var);
1477 // The first mention of a function argument gets the FunctionBeginSym
1478 // label, so arguments are visible when breaking at function entry.
1480 if (DV.isVariable() && DV.getTag() == dwarf::DW_TAG_arg_variable &&
1481 getDISubprogram(DV.getContext()).describes(MF->getFunction()))
1482 LabelsBeforeInsn[MI] = FunctionBeginSym;
1484 // We have seen this variable before. Try to coalesce DBG_VALUEs.
1485 const MachineInstr *Prev = History.back();
1486 if (Prev->isDebugValue()) {
1487 // Coalesce identical entries at the end of History.
1488 if (History.size() >= 2 &&
1489 Prev->isIdenticalTo(History[History.size() - 2])) {
1490 DEBUG(dbgs() << "Coalescing identical DBG_VALUE entries:\n"
1491 << "\t" << *Prev << "\t"
1492 << *History[History.size() - 2] << "\n");
1496 // Terminate old register assignments that don't reach MI;
1497 MachineFunction::const_iterator PrevMBB = Prev->getParent();
1498 if (PrevMBB != I && (!AtBlockEntry || std::next(PrevMBB) != I) &&
1499 isDbgValueInDefinedReg(Prev)) {
1500 // Previous register assignment needs to terminate at the end of
1502 MachineBasicBlock::const_iterator LastMI =
1503 PrevMBB->getLastNonDebugInstr();
1504 if (LastMI == PrevMBB->end()) {
1505 // Drop DBG_VALUE for empty range.
1506 DEBUG(dbgs() << "Dropping DBG_VALUE for empty range:\n"
1507 << "\t" << *Prev << "\n");
1509 } else if (std::next(PrevMBB) != PrevMBB->getParent()->end())
1510 // Terminate after LastMI.
1511 History.push_back(LastMI);
1515 History.push_back(MI);
1517 // Not a DBG_VALUE instruction.
1518 if (!MI->isPosition())
1519 AtBlockEntry = false;
1521 // First known non-DBG_VALUE and non-frame setup location marks
1522 // the beginning of the function body.
1523 if (!MI->getFlag(MachineInstr::FrameSetup) &&
1524 (PrologEndLoc.isUnknown() && !MI->getDebugLoc().isUnknown()))
1525 PrologEndLoc = MI->getDebugLoc();
1527 // Check if the instruction clobbers any registers with debug vars.
1528 for (const MachineOperand &MO : MI->operands()) {
1529 if (!MO.isReg() || !MO.isDef() || !MO.getReg())
1531 for (MCRegAliasIterator AI(MO.getReg(), TRI, true); AI.isValid();
1534 const MDNode *Var = LiveUserVar[Reg];
1537 // Reg is now clobbered.
1538 LiveUserVar[Reg] = 0;
1540 // Was MD last defined by a DBG_VALUE referring to Reg?
1541 DbgValueHistoryMap::iterator HistI = DbgValues.find(Var);
1542 if (HistI == DbgValues.end())
1544 SmallVectorImpl<const MachineInstr *> &History = HistI->second;
1545 if (History.empty())
1547 const MachineInstr *Prev = History.back();
1548 // Sanity-check: Register assignments are terminated at the end of
1550 if (!Prev->isDebugValue() || Prev->getParent() != MI->getParent())
1552 // Is the variable still in Reg?
1553 if (!isDbgValueInDefinedReg(Prev) ||
1554 Prev->getOperand(0).getReg() != Reg)
1556 // Var is clobbered. Make sure the next instruction gets a label.
1557 History.push_back(MI);
1564 for (auto &I : DbgValues) {
1565 SmallVectorImpl<const MachineInstr *> &History = I.second;
1566 if (History.empty())
1569 // Make sure the final register assignments are terminated.
1570 const MachineInstr *Prev = History.back();
1571 if (Prev->isDebugValue() && isDbgValueInDefinedReg(Prev)) {
1572 const MachineBasicBlock *PrevMBB = Prev->getParent();
1573 MachineBasicBlock::const_iterator LastMI =
1574 PrevMBB->getLastNonDebugInstr();
1575 if (LastMI == PrevMBB->end())
1576 // Drop DBG_VALUE for empty range.
1578 else if (PrevMBB != &PrevMBB->getParent()->back()) {
1579 // Terminate after LastMI.
1580 History.push_back(LastMI);
1583 // Request labels for the full history.
1584 for (const MachineInstr *MI : History) {
1585 if (MI->isDebugValue())
1586 requestLabelBeforeInsn(MI);
1588 requestLabelAfterInsn(MI);
1592 PrevInstLoc = DebugLoc();
1593 PrevLabel = FunctionBeginSym;
1595 // Record beginning of function.
1596 if (!PrologEndLoc.isUnknown()) {
1597 DebugLoc FnStartDL =
1598 PrologEndLoc.getFnDebugLoc(MF->getFunction()->getContext());
1600 FnStartDL.getLine(), FnStartDL.getCol(),
1601 FnStartDL.getScope(MF->getFunction()->getContext()),
1602 // We'd like to list the prologue as "not statements" but GDB behaves
1603 // poorly if we do that. Revisit this with caution/GDB (7.5+) testing.
1604 DWARF2_FLAG_IS_STMT);
1608 void DwarfDebug::addScopeVariable(LexicalScope *LS, DbgVariable *Var) {
1609 SmallVectorImpl<DbgVariable *> &Vars = ScopeVariables[LS];
1610 DIVariable DV = Var->getVariable();
1611 // Variables with positive arg numbers are parameters.
1612 if (unsigned ArgNum = DV.getArgNumber()) {
1613 // Keep all parameters in order at the start of the variable list to ensure
1614 // function types are correct (no out-of-order parameters)
1616 // This could be improved by only doing it for optimized builds (unoptimized
1617 // builds have the right order to begin with), searching from the back (this
1618 // would catch the unoptimized case quickly), or doing a binary search
1619 // rather than linear search.
1620 SmallVectorImpl<DbgVariable *>::iterator I = Vars.begin();
1621 while (I != Vars.end()) {
1622 unsigned CurNum = (*I)->getVariable().getArgNumber();
1623 // A local (non-parameter) variable has been found, insert immediately
1627 // A later indexed parameter has been found, insert immediately before it.
1628 if (CurNum > ArgNum)
1632 Vars.insert(I, Var);
1636 Vars.push_back(Var);
1639 // Gather and emit post-function debug information.
1640 void DwarfDebug::endFunction(const MachineFunction *MF) {
1641 // Every beginFunction(MF) call should be followed by an endFunction(MF) call,
1642 // though the beginFunction may not be called at all.
1643 // We should handle both cases.
1647 assert(CurFn == MF);
1650 if (!MMI->hasDebugInfo() || LScopes.empty()) {
1651 // If we don't have a lexical scope for this function then there will
1652 // be a hole in the range information. Keep note of this by setting the
1653 // previously used section to nullptr.
1654 PrevSection = nullptr;
1660 // Define end label for subprogram.
1661 FunctionEndSym = Asm->GetTempSymbol("func_end", Asm->getFunctionNumber());
1662 // Assumes in correct section after the entry point.
1663 Asm->OutStreamer.EmitLabel(FunctionEndSym);
1665 // Set DwarfDwarfCompileUnitID in MCContext to default value.
1666 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1668 SmallPtrSet<const MDNode *, 16> ProcessedVars;
1669 collectVariableInfo(ProcessedVars);
1671 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1672 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1673 assert(TheCU && "Unable to find compile unit!");
1675 // Construct abstract scopes.
1676 for (LexicalScope *AScope : LScopes.getAbstractScopesList()) {
1677 DISubprogram SP(AScope->getScopeNode());
1678 if (SP.isSubprogram()) {
1679 // Collect info for variables that were optimized out.
1680 DIArray Variables = SP.getVariables();
1681 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1682 DIVariable DV(Variables.getElement(i));
1683 if (!DV || !DV.isVariable() || !ProcessedVars.insert(DV))
1685 // Check that DbgVariable for DV wasn't created earlier, when
1686 // findAbstractVariable() was called for inlined instance of DV.
1687 LLVMContext &Ctx = DV->getContext();
1688 DIVariable CleanDV = cleanseInlinedVariable(DV, Ctx);
1689 if (AbstractVariables.lookup(CleanDV))
1691 if (LexicalScope *Scope = LScopes.findAbstractScope(DV.getContext()))
1692 addScopeVariable(Scope, new DbgVariable(DV, NULL, this));
1695 if (ProcessedSPNodes.count(AScope->getScopeNode()) == 0)
1696 constructScopeDIE(TheCU, AScope);
1699 DIE *CurFnDIE = constructScopeDIE(TheCU, FnScope);
1700 if (!CurFn->getTarget().Options.DisableFramePointerElim(*CurFn))
1701 TheCU->addFlag(CurFnDIE, dwarf::DW_AT_APPLE_omit_frame_ptr);
1703 // Add the range of this function to the list of ranges for the CU.
1704 RangeSpan Span(FunctionBeginSym, FunctionEndSym);
1705 TheCU->addRange(std::move(Span));
1706 PrevSection = Asm->getCurrentSection();
1710 for (auto &I : ScopeVariables)
1711 DeleteContainerPointers(I.second);
1712 ScopeVariables.clear();
1713 DeleteContainerPointers(CurrentFnArguments);
1714 UserVariables.clear();
1716 AbstractVariables.clear();
1717 LabelsBeforeInsn.clear();
1718 LabelsAfterInsn.clear();
1723 // Register a source line with debug info. Returns the unique label that was
1724 // emitted and which provides correspondence to the source line list.
1725 void DwarfDebug::recordSourceLine(unsigned Line, unsigned Col, const MDNode *S,
1730 unsigned Discriminator = 0;
1732 DIDescriptor Scope(S);
1734 if (Scope.isCompileUnit()) {
1735 DICompileUnit CU(S);
1736 Fn = CU.getFilename();
1737 Dir = CU.getDirectory();
1738 } else if (Scope.isFile()) {
1740 Fn = F.getFilename();
1741 Dir = F.getDirectory();
1742 } else if (Scope.isSubprogram()) {
1744 Fn = SP.getFilename();
1745 Dir = SP.getDirectory();
1746 } else if (Scope.isLexicalBlockFile()) {
1747 DILexicalBlockFile DBF(S);
1748 Fn = DBF.getFilename();
1749 Dir = DBF.getDirectory();
1750 } else if (Scope.isLexicalBlock()) {
1751 DILexicalBlock DB(S);
1752 Fn = DB.getFilename();
1753 Dir = DB.getDirectory();
1754 Discriminator = DB.getDiscriminator();
1756 llvm_unreachable("Unexpected scope info");
1758 unsigned CUID = Asm->OutStreamer.getContext().getDwarfCompileUnitID();
1759 Src = static_cast<DwarfCompileUnit *>(InfoHolder.getUnits()[CUID])
1760 ->getOrCreateSourceID(Fn, Dir);
1762 Asm->OutStreamer.EmitDwarfLocDirective(Src, Line, Col, Flags, 0,
1766 //===----------------------------------------------------------------------===//
1768 //===----------------------------------------------------------------------===//
1770 // Compute the size and offset of a DIE. The offset is relative to start of the
1771 // CU. It returns the offset after laying out the DIE.
1772 unsigned DwarfFile::computeSizeAndOffset(DIE *Die, unsigned Offset) {
1773 // Record the abbreviation.
1774 assignAbbrevNumber(Die->getAbbrev());
1776 // Get the abbreviation for this DIE.
1777 const DIEAbbrev &Abbrev = Die->getAbbrev();
1780 Die->setOffset(Offset);
1782 // Start the size with the size of abbreviation code.
1783 Offset += getULEB128Size(Die->getAbbrevNumber());
1785 const SmallVectorImpl<DIEValue *> &Values = Die->getValues();
1786 const SmallVectorImpl<DIEAbbrevData> &AbbrevData = Abbrev.getData();
1788 // Size the DIE attribute values.
1789 for (unsigned i = 0, N = Values.size(); i < N; ++i)
1790 // Size attribute value.
1791 Offset += Values[i]->SizeOf(Asm, AbbrevData[i].getForm());
1793 // Get the children.
1794 const std::vector<DIE *> &Children = Die->getChildren();
1796 // Size the DIE children if any.
1797 if (!Children.empty()) {
1798 assert(Abbrev.hasChildren() && "Children flag not set");
1800 for (DIE *Child : Children)
1801 Offset = computeSizeAndOffset(Child, Offset);
1803 // End of children marker.
1804 Offset += sizeof(int8_t);
1807 Die->setSize(Offset - Die->getOffset());
1811 // Compute the size and offset for each DIE.
1812 void DwarfFile::computeSizeAndOffsets() {
1813 // Offset from the first CU in the debug info section is 0 initially.
1814 unsigned SecOffset = 0;
1816 // Iterate over each compile unit and set the size and offsets for each
1817 // DIE within each compile unit. All offsets are CU relative.
1818 for (DwarfUnit *TheU : CUs) {
1819 TheU->setDebugInfoOffset(SecOffset);
1821 // CU-relative offset is reset to 0 here.
1822 unsigned Offset = sizeof(int32_t) + // Length of Unit Info
1823 TheU->getHeaderSize(); // Unit-specific headers
1825 // EndOffset here is CU-relative, after laying out
1826 // all of the CU DIE.
1827 unsigned EndOffset = computeSizeAndOffset(TheU->getUnitDie(), Offset);
1828 SecOffset += EndOffset;
1832 // Emit initial Dwarf sections with a label at the start of each one.
1833 void DwarfDebug::emitSectionLabels() {
1834 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
1836 // Dwarf sections base addresses.
1837 DwarfInfoSectionSym =
1838 emitSectionSym(Asm, TLOF.getDwarfInfoSection(), "section_info");
1839 if (useSplitDwarf())
1840 DwarfInfoDWOSectionSym =
1841 emitSectionSym(Asm, TLOF.getDwarfInfoDWOSection(), "section_info_dwo");
1842 DwarfAbbrevSectionSym =
1843 emitSectionSym(Asm, TLOF.getDwarfAbbrevSection(), "section_abbrev");
1844 if (useSplitDwarf())
1845 DwarfAbbrevDWOSectionSym = emitSectionSym(
1846 Asm, TLOF.getDwarfAbbrevDWOSection(), "section_abbrev_dwo");
1847 if (GenerateARangeSection)
1848 emitSectionSym(Asm, TLOF.getDwarfARangesSection());
1850 DwarfLineSectionSym =
1851 emitSectionSym(Asm, TLOF.getDwarfLineSection(), "section_line");
1852 emitSectionSym(Asm, TLOF.getDwarfLocSection());
1853 if (GenerateGnuPubSections) {
1854 DwarfGnuPubNamesSectionSym =
1855 emitSectionSym(Asm, TLOF.getDwarfGnuPubNamesSection());
1856 DwarfGnuPubTypesSectionSym =
1857 emitSectionSym(Asm, TLOF.getDwarfGnuPubTypesSection());
1858 } else if (HasDwarfPubSections) {
1859 emitSectionSym(Asm, TLOF.getDwarfPubNamesSection());
1860 emitSectionSym(Asm, TLOF.getDwarfPubTypesSection());
1863 DwarfStrSectionSym =
1864 emitSectionSym(Asm, TLOF.getDwarfStrSection(), "info_string");
1865 if (useSplitDwarf()) {
1866 DwarfStrDWOSectionSym =
1867 emitSectionSym(Asm, TLOF.getDwarfStrDWOSection(), "skel_string");
1868 DwarfAddrSectionSym =
1869 emitSectionSym(Asm, TLOF.getDwarfAddrSection(), "addr_sec");
1871 DwarfDebugRangeSectionSym =
1872 emitSectionSym(Asm, TLOF.getDwarfRangesSection(), "debug_range");
1874 DwarfDebugLocSectionSym =
1875 emitSectionSym(Asm, TLOF.getDwarfLocSection(), "section_debug_loc");
1878 // Recursively emits a debug information entry.
1879 void DwarfDebug::emitDIE(DIE *Die) {
1880 // Get the abbreviation for this DIE.
1881 const DIEAbbrev &Abbrev = Die->getAbbrev();
1883 // Emit the code (index) for the abbreviation.
1884 if (Asm->isVerbose())
1885 Asm->OutStreamer.AddComment("Abbrev [" + Twine(Abbrev.getNumber()) +
1886 "] 0x" + Twine::utohexstr(Die->getOffset()) +
1887 ":0x" + Twine::utohexstr(Die->getSize()) + " " +
1888 dwarf::TagString(Abbrev.getTag()));
1889 Asm->EmitULEB128(Abbrev.getNumber());
1891 const SmallVectorImpl<DIEValue *> &Values = Die->getValues();
1892 const SmallVectorImpl<DIEAbbrevData> &AbbrevData = Abbrev.getData();
1894 // Emit the DIE attribute values.
1895 for (unsigned i = 0, N = Values.size(); i < N; ++i) {
1896 dwarf::Attribute Attr = AbbrevData[i].getAttribute();
1897 dwarf::Form Form = AbbrevData[i].getForm();
1898 assert(Form && "Too many attributes for DIE (check abbreviation)");
1900 if (Asm->isVerbose()) {
1901 Asm->OutStreamer.AddComment(dwarf::AttributeString(Attr));
1902 if (Attr == dwarf::DW_AT_accessibility)
1903 Asm->OutStreamer.AddComment(dwarf::AccessibilityString(
1904 cast<DIEInteger>(Values[i])->getValue()));
1907 // Emit an attribute using the defined form.
1908 Values[i]->EmitValue(Asm, Form);
1911 // Emit the DIE children if any.
1912 if (Abbrev.hasChildren()) {
1913 const std::vector<DIE *> &Children = Die->getChildren();
1915 for (DIE *Child : Children)
1918 Asm->OutStreamer.AddComment("End Of Children Mark");
1923 // Emit the various dwarf units to the unit section USection with
1924 // the abbreviations going into ASection.
1925 void DwarfFile::emitUnits(DwarfDebug *DD, const MCSection *ASection,
1926 const MCSymbol *ASectionSym) {
1927 for (DwarfUnit *TheU : CUs) {
1928 DIE *Die = TheU->getUnitDie();
1929 const MCSection *USection = TheU->getSection();
1930 Asm->OutStreamer.SwitchSection(USection);
1932 // Emit the compile units header.
1933 Asm->OutStreamer.EmitLabel(TheU->getLabelBegin());
1935 // Emit size of content not including length itself
1936 Asm->OutStreamer.AddComment("Length of Unit");
1937 Asm->EmitInt32(TheU->getHeaderSize() + Die->getSize());
1939 TheU->emitHeader(ASection, ASectionSym);
1942 Asm->OutStreamer.EmitLabel(TheU->getLabelEnd());
1946 // Emit the debug info section.
1947 void DwarfDebug::emitDebugInfo() {
1948 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1950 Holder.emitUnits(this, Asm->getObjFileLowering().getDwarfAbbrevSection(),
1951 DwarfAbbrevSectionSym);
1954 // Emit the abbreviation section.
1955 void DwarfDebug::emitAbbreviations() {
1956 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1958 Holder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevSection());
1961 void DwarfFile::emitAbbrevs(const MCSection *Section) {
1962 // Check to see if it is worth the effort.
1963 if (!Abbreviations.empty()) {
1964 // Start the debug abbrev section.
1965 Asm->OutStreamer.SwitchSection(Section);
1967 // For each abbrevation.
1968 for (const DIEAbbrev *Abbrev : Abbreviations) {
1969 // Emit the abbrevations code (base 1 index.)
1970 Asm->EmitULEB128(Abbrev->getNumber(), "Abbreviation Code");
1972 // Emit the abbreviations data.
1976 // Mark end of abbreviations.
1977 Asm->EmitULEB128(0, "EOM(3)");
1981 // Emit the last address of the section and the end of the line matrix.
1982 void DwarfDebug::emitEndOfLineMatrix(unsigned SectionEnd) {
1983 // Define last address of section.
1984 Asm->OutStreamer.AddComment("Extended Op");
1987 Asm->OutStreamer.AddComment("Op size");
1988 Asm->EmitInt8(Asm->getDataLayout().getPointerSize() + 1);
1989 Asm->OutStreamer.AddComment("DW_LNE_set_address");
1990 Asm->EmitInt8(dwarf::DW_LNE_set_address);
1992 Asm->OutStreamer.AddComment("Section end label");
1994 Asm->OutStreamer.EmitSymbolValue(
1995 Asm->GetTempSymbol("section_end", SectionEnd),
1996 Asm->getDataLayout().getPointerSize());
1998 // Mark end of matrix.
1999 Asm->OutStreamer.AddComment("DW_LNE_end_sequence");
2005 // Emit visible names into a hashed accelerator table section.
2006 void DwarfDebug::emitAccelNames() {
2008 DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset, dwarf::DW_FORM_data4));
2009 for (DwarfUnit *TheU : getUnits()) {
2010 for (const auto &GI : TheU->getAccelNames()) {
2011 StringRef Name = GI.getKey();
2012 for (const DIE *D : GI.second)
2013 AT.AddName(Name, D);
2017 AT.FinalizeTable(Asm, "Names");
2018 Asm->OutStreamer.SwitchSection(
2019 Asm->getObjFileLowering().getDwarfAccelNamesSection());
2020 MCSymbol *SectionBegin = Asm->GetTempSymbol("names_begin");
2021 Asm->OutStreamer.EmitLabel(SectionBegin);
2023 // Emit the full data.
2024 AT.Emit(Asm, SectionBegin, &InfoHolder);
2027 // Emit objective C classes and categories into a hashed accelerator table
2029 void DwarfDebug::emitAccelObjC() {
2031 DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset, dwarf::DW_FORM_data4));
2032 for (DwarfUnit *TheU : getUnits()) {
2033 for (const auto &GI : TheU->getAccelObjC()) {
2034 StringRef Name = GI.getKey();
2035 for (const DIE *D : GI.second)
2036 AT.AddName(Name, D);
2040 AT.FinalizeTable(Asm, "ObjC");
2041 Asm->OutStreamer.SwitchSection(
2042 Asm->getObjFileLowering().getDwarfAccelObjCSection());
2043 MCSymbol *SectionBegin = Asm->GetTempSymbol("objc_begin");
2044 Asm->OutStreamer.EmitLabel(SectionBegin);
2046 // Emit the full data.
2047 AT.Emit(Asm, SectionBegin, &InfoHolder);
2050 // Emit namespace dies into a hashed accelerator table.
2051 void DwarfDebug::emitAccelNamespaces() {
2053 DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset, dwarf::DW_FORM_data4));
2054 for (DwarfUnit *TheU : getUnits()) {
2055 for (const auto &GI : TheU->getAccelNamespace()) {
2056 StringRef Name = GI.getKey();
2057 for (const DIE *D : GI.second)
2058 AT.AddName(Name, D);
2062 AT.FinalizeTable(Asm, "namespac");
2063 Asm->OutStreamer.SwitchSection(
2064 Asm->getObjFileLowering().getDwarfAccelNamespaceSection());
2065 MCSymbol *SectionBegin = Asm->GetTempSymbol("namespac_begin");
2066 Asm->OutStreamer.EmitLabel(SectionBegin);
2068 // Emit the full data.
2069 AT.Emit(Asm, SectionBegin, &InfoHolder);
2072 // Emit type dies into a hashed accelerator table.
2073 void DwarfDebug::emitAccelTypes() {
2074 std::vector<DwarfAccelTable::Atom> Atoms;
2076 DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset, dwarf::DW_FORM_data4));
2078 DwarfAccelTable::Atom(dwarf::DW_ATOM_die_tag, dwarf::DW_FORM_data2));
2080 DwarfAccelTable::Atom(dwarf::DW_ATOM_type_flags, dwarf::DW_FORM_data1));
2081 DwarfAccelTable AT(Atoms);
2082 for (DwarfUnit *TheU : getUnits()) {
2083 for (const auto &GI : TheU->getAccelTypes()) {
2084 StringRef Name = GI.getKey();
2085 for (const auto &DI : GI.second)
2086 AT.AddName(Name, DI.first, DI.second);
2090 AT.FinalizeTable(Asm, "types");
2091 Asm->OutStreamer.SwitchSection(
2092 Asm->getObjFileLowering().getDwarfAccelTypesSection());
2093 MCSymbol *SectionBegin = Asm->GetTempSymbol("types_begin");
2094 Asm->OutStreamer.EmitLabel(SectionBegin);
2096 // Emit the full data.
2097 AT.Emit(Asm, SectionBegin, &InfoHolder);
2100 // Public name handling.
2101 // The format for the various pubnames:
2103 // dwarf pubnames - offset/name pairs where the offset is the offset into the CU
2104 // for the DIE that is named.
2106 // gnu pubnames - offset/index value/name tuples where the offset is the offset
2107 // into the CU and the index value is computed according to the type of value
2108 // for the DIE that is named.
2110 // For type units the offset is the offset of the skeleton DIE. For split dwarf
2111 // it's the offset within the debug_info/debug_types dwo section, however, the
2112 // reference in the pubname header doesn't change.
2114 /// computeIndexValue - Compute the gdb index value for the DIE and CU.
2115 static dwarf::PubIndexEntryDescriptor computeIndexValue(DwarfUnit *CU,
2117 dwarf::GDBIndexEntryLinkage Linkage = dwarf::GIEL_STATIC;
2119 // We could have a specification DIE that has our most of our knowledge,
2120 // look for that now.
2121 DIEValue *SpecVal = Die->findAttribute(dwarf::DW_AT_specification);
2123 DIE *SpecDIE = cast<DIEEntry>(SpecVal)->getEntry();
2124 if (SpecDIE->findAttribute(dwarf::DW_AT_external))
2125 Linkage = dwarf::GIEL_EXTERNAL;
2126 } else if (Die->findAttribute(dwarf::DW_AT_external))
2127 Linkage = dwarf::GIEL_EXTERNAL;
2129 switch (Die->getTag()) {
2130 case dwarf::DW_TAG_class_type:
2131 case dwarf::DW_TAG_structure_type:
2132 case dwarf::DW_TAG_union_type:
2133 case dwarf::DW_TAG_enumeration_type:
2134 return dwarf::PubIndexEntryDescriptor(
2135 dwarf::GIEK_TYPE, CU->getLanguage() != dwarf::DW_LANG_C_plus_plus
2136 ? dwarf::GIEL_STATIC
2137 : dwarf::GIEL_EXTERNAL);
2138 case dwarf::DW_TAG_typedef:
2139 case dwarf::DW_TAG_base_type:
2140 case dwarf::DW_TAG_subrange_type:
2141 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_TYPE, dwarf::GIEL_STATIC);
2142 case dwarf::DW_TAG_namespace:
2143 return dwarf::GIEK_TYPE;
2144 case dwarf::DW_TAG_subprogram:
2145 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_FUNCTION, Linkage);
2146 case dwarf::DW_TAG_constant:
2147 case dwarf::DW_TAG_variable:
2148 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE, Linkage);
2149 case dwarf::DW_TAG_enumerator:
2150 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE,
2151 dwarf::GIEL_STATIC);
2153 return dwarf::GIEK_NONE;
2157 /// emitDebugPubNames - Emit visible names into a debug pubnames section.
2159 void DwarfDebug::emitDebugPubNames(bool GnuStyle) {
2160 const MCSection *PSec =
2161 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubNamesSection()
2162 : Asm->getObjFileLowering().getDwarfPubNamesSection();
2164 emitDebugPubSection(GnuStyle, PSec, "Names", &DwarfUnit::getGlobalNames);
2167 void DwarfDebug::emitDebugPubSection(
2168 bool GnuStyle, const MCSection *PSec, StringRef Name,
2169 const StringMap<const DIE *> &(DwarfUnit::*Accessor)() const) {
2170 for (const auto &NU : CUMap) {
2171 DwarfCompileUnit *TheU = NU.second;
2173 const auto &Globals = (TheU->*Accessor)();
2175 if (Globals.empty())
2178 if (auto Skeleton = static_cast<DwarfCompileUnit *>(TheU->getSkeleton()))
2180 unsigned ID = TheU->getUniqueID();
2182 // Start the dwarf pubnames section.
2183 Asm->OutStreamer.SwitchSection(PSec);
2186 Asm->OutStreamer.AddComment("Length of Public " + Name + " Info");
2187 MCSymbol *BeginLabel = Asm->GetTempSymbol("pub" + Name + "_begin", ID);
2188 MCSymbol *EndLabel = Asm->GetTempSymbol("pub" + Name + "_end", ID);
2189 Asm->EmitLabelDifference(EndLabel, BeginLabel, 4);
2191 Asm->OutStreamer.EmitLabel(BeginLabel);
2193 Asm->OutStreamer.AddComment("DWARF Version");
2194 Asm->EmitInt16(dwarf::DW_PUBNAMES_VERSION);
2196 Asm->OutStreamer.AddComment("Offset of Compilation Unit Info");
2197 Asm->EmitSectionOffset(TheU->getLabelBegin(), TheU->getSectionSym());
2199 Asm->OutStreamer.AddComment("Compilation Unit Length");
2200 Asm->EmitLabelDifference(TheU->getLabelEnd(), TheU->getLabelBegin(), 4);
2202 // Emit the pubnames for this compilation unit.
2203 for (const auto &GI : Globals) {
2204 const char *Name = GI.getKeyData();
2205 const DIE *Entity = GI.second;
2207 Asm->OutStreamer.AddComment("DIE offset");
2208 Asm->EmitInt32(Entity->getOffset());
2211 dwarf::PubIndexEntryDescriptor Desc = computeIndexValue(TheU, Entity);
2212 Asm->OutStreamer.AddComment(
2213 Twine("Kind: ") + dwarf::GDBIndexEntryKindString(Desc.Kind) + ", " +
2214 dwarf::GDBIndexEntryLinkageString(Desc.Linkage));
2215 Asm->EmitInt8(Desc.toBits());
2218 Asm->OutStreamer.AddComment("External Name");
2219 Asm->OutStreamer.EmitBytes(StringRef(Name, GI.getKeyLength() + 1));
2222 Asm->OutStreamer.AddComment("End Mark");
2224 Asm->OutStreamer.EmitLabel(EndLabel);
2228 void DwarfDebug::emitDebugPubTypes(bool GnuStyle) {
2229 const MCSection *PSec =
2230 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubTypesSection()
2231 : Asm->getObjFileLowering().getDwarfPubTypesSection();
2233 emitDebugPubSection(GnuStyle, PSec, "Types", &DwarfUnit::getGlobalTypes);
2236 // Emit strings into a string section.
2237 void DwarfFile::emitStrings(const MCSection *StrSection,
2238 const MCSection *OffsetSection = NULL,
2239 const MCSymbol *StrSecSym = NULL) {
2241 if (StringPool.empty())
2244 // Start the dwarf str section.
2245 Asm->OutStreamer.SwitchSection(StrSection);
2247 // Get all of the string pool entries and put them in an array by their ID so
2248 // we can sort them.
2249 SmallVector<std::pair<unsigned, const StrPool::value_type *>, 64 > Entries;
2251 for (const auto &I : StringPool)
2252 Entries.push_back(std::make_pair(I.second.second, &I));
2254 array_pod_sort(Entries.begin(), Entries.end());
2256 for (const auto &Entry : Entries) {
2257 // Emit a label for reference from debug information entries.
2258 Asm->OutStreamer.EmitLabel(Entry.second->getValue().first);
2260 // Emit the string itself with a terminating null byte.
2261 Asm->OutStreamer.EmitBytes(StringRef(Entry.second->getKeyData(),
2262 Entry.second->getKeyLength() + 1));
2265 // If we've got an offset section go ahead and emit that now as well.
2266 if (OffsetSection) {
2267 Asm->OutStreamer.SwitchSection(OffsetSection);
2268 unsigned offset = 0;
2269 unsigned size = 4; // FIXME: DWARF64 is 8.
2270 for (const auto &Entry : Entries) {
2271 Asm->OutStreamer.EmitIntValue(offset, size);
2272 offset += Entry.second->getKeyLength() + 1;
2277 // Emit addresses into the section given.
2278 void DwarfFile::emitAddresses(const MCSection *AddrSection) {
2280 if (AddressPool.empty())
2283 // Start the dwarf addr section.
2284 Asm->OutStreamer.SwitchSection(AddrSection);
2286 // Order the address pool entries by ID
2287 SmallVector<const MCExpr *, 64> Entries(AddressPool.size());
2289 for (const auto &I : AddressPool)
2290 Entries[I.second.Number] =
2292 ? Asm->getObjFileLowering().getDebugThreadLocalSymbol(I.first)
2293 : MCSymbolRefExpr::Create(I.first, Asm->OutContext);
2295 for (const MCExpr *Entry : Entries)
2296 Asm->OutStreamer.EmitValue(Entry, Asm->getDataLayout().getPointerSize());
2299 // Emit visible names into a debug str section.
2300 void DwarfDebug::emitDebugStr() {
2301 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
2302 Holder.emitStrings(Asm->getObjFileLowering().getDwarfStrSection());
2305 void DwarfDebug::emitDebugLocEntry(ByteStreamer &Streamer,
2306 const DebugLocEntry &Entry) {
2307 DIVariable DV(Entry.getVariable());
2308 if (Entry.isInt()) {
2309 DIBasicType BTy(resolve(DV.getType()));
2310 if (BTy.Verify() && (BTy.getEncoding() == dwarf::DW_ATE_signed ||
2311 BTy.getEncoding() == dwarf::DW_ATE_signed_char)) {
2312 Streamer.EmitInt8(dwarf::DW_OP_consts, "DW_OP_consts");
2313 Streamer.EmitSLEB128(Entry.getInt());
2315 Streamer.EmitInt8(dwarf::DW_OP_constu, "DW_OP_constu");
2316 Streamer.EmitULEB128(Entry.getInt());
2318 } else if (Entry.isLocation()) {
2319 MachineLocation Loc = Entry.getLoc();
2320 if (!DV.hasComplexAddress())
2322 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2324 // Complex address entry.
2325 unsigned N = DV.getNumAddrElements();
2327 if (N >= 2 && DV.getAddrElement(0) == DIBuilder::OpPlus) {
2328 if (Loc.getOffset()) {
2330 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2331 Streamer.EmitInt8(dwarf::DW_OP_deref, "DW_OP_deref");
2332 Streamer.EmitInt8(dwarf::DW_OP_plus_uconst, "DW_OP_plus_uconst");
2333 Streamer.EmitSLEB128(DV.getAddrElement(1));
2335 // If first address element is OpPlus then emit
2336 // DW_OP_breg + Offset instead of DW_OP_reg + Offset.
2337 MachineLocation TLoc(Loc.getReg(), DV.getAddrElement(1));
2338 Asm->EmitDwarfRegOp(Streamer, TLoc, DV.isIndirect());
2342 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2345 // Emit remaining complex address elements.
2346 for (; i < N; ++i) {
2347 uint64_t Element = DV.getAddrElement(i);
2348 if (Element == DIBuilder::OpPlus) {
2349 Streamer.EmitInt8(dwarf::DW_OP_plus_uconst, "DW_OP_plus_uconst");
2350 Streamer.EmitULEB128(DV.getAddrElement(++i));
2351 } else if (Element == DIBuilder::OpDeref) {
2353 Streamer.EmitInt8(dwarf::DW_OP_deref, "DW_OP_deref");
2355 llvm_unreachable("unknown Opcode found in complex address");
2359 // else ... ignore constant fp. There is not any good way to
2360 // to represent them here in dwarf.
2364 // Emit locations into the debug loc section.
2365 void DwarfDebug::emitDebugLoc() {
2366 if (DotDebugLocEntries.empty())
2369 for (SmallVectorImpl<DebugLocEntry>::iterator
2370 I = DotDebugLocEntries.begin(),
2371 E = DotDebugLocEntries.end();
2373 DebugLocEntry &Entry = *I;
2374 if (I + 1 != DotDebugLocEntries.end())
2378 // Start the dwarf loc section.
2379 Asm->OutStreamer.SwitchSection(
2380 Asm->getObjFileLowering().getDwarfLocSection());
2381 unsigned char Size = Asm->getDataLayout().getPointerSize();
2382 Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("debug_loc", 0));
2384 for (SmallVectorImpl<DebugLocEntry>::const_iterator
2385 I = DotDebugLocEntries.begin(),
2386 E = DotDebugLocEntries.end();
2387 I != E; ++I, ++index) {
2388 const DebugLocEntry &Entry = *I;
2389 if (Entry.isMerged())
2392 if (Entry.isEmpty()) {
2393 Asm->OutStreamer.EmitIntValue(0, Size);
2394 Asm->OutStreamer.EmitIntValue(0, Size);
2395 Asm->OutStreamer.EmitLabel(Asm->GetTempSymbol("debug_loc", index));
2397 // Set up the range.
2398 Asm->OutStreamer.EmitSymbolValue(Entry.getBeginSym(), Size);
2399 Asm->OutStreamer.EmitSymbolValue(Entry.getEndSym(), Size);
2400 Asm->OutStreamer.AddComment("Loc expr size");
2401 MCSymbol *begin = Asm->OutStreamer.getContext().CreateTempSymbol();
2402 MCSymbol *end = Asm->OutStreamer.getContext().CreateTempSymbol();
2403 Asm->EmitLabelDifference(end, begin, 2);
2404 Asm->OutStreamer.EmitLabel(begin);
2406 APByteStreamer Streamer(*Asm);
2407 emitDebugLocEntry(Streamer, Entry);
2409 Asm->OutStreamer.EmitLabel(end);
2415 const MCSymbol *Start, *End;
2418 // Emit a debug aranges section, containing a CU lookup for any
2419 // address we can tie back to a CU.
2420 void DwarfDebug::emitDebugARanges() {
2421 // Start the dwarf aranges section.
2422 Asm->OutStreamer.SwitchSection(
2423 Asm->getObjFileLowering().getDwarfARangesSection());
2425 typedef DenseMap<DwarfCompileUnit *, std::vector<ArangeSpan> > SpansType;
2429 // Build a list of sections used.
2430 std::vector<const MCSection *> Sections;
2431 for (const auto &it : SectionMap) {
2432 const MCSection *Section = it.first;
2433 Sections.push_back(Section);
2436 // Sort the sections into order.
2437 // This is only done to ensure consistent output order across different runs.
2438 std::sort(Sections.begin(), Sections.end(), SectionSort);
2440 // Build a set of address spans, sorted by CU.
2441 for (const MCSection *Section : Sections) {
2442 SmallVector<SymbolCU, 8> &List = SectionMap[Section];
2443 if (List.size() < 2)
2446 // Sort the symbols by offset within the section.
2447 std::sort(List.begin(), List.end(),
2448 [&](const SymbolCU &A, const SymbolCU &B) {
2449 unsigned IA = A.Sym ? Asm->OutStreamer.GetSymbolOrder(A.Sym) : 0;
2450 unsigned IB = B.Sym ? Asm->OutStreamer.GetSymbolOrder(B.Sym) : 0;
2452 // Symbols with no order assigned should be placed at the end.
2453 // (e.g. section end labels)
2461 // If we have no section (e.g. common), just write out
2462 // individual spans for each symbol.
2463 if (Section == NULL) {
2464 for (const SymbolCU &Cur : List) {
2466 Span.Start = Cur.Sym;
2469 Spans[Cur.CU].push_back(Span);
2472 // Build spans between each label.
2473 const MCSymbol *StartSym = List[0].Sym;
2474 for (size_t n = 1, e = List.size(); n < e; n++) {
2475 const SymbolCU &Prev = List[n - 1];
2476 const SymbolCU &Cur = List[n];
2478 // Try and build the longest span we can within the same CU.
2479 if (Cur.CU != Prev.CU) {
2481 Span.Start = StartSym;
2483 Spans[Prev.CU].push_back(Span);
2490 unsigned PtrSize = Asm->getDataLayout().getPointerSize();
2492 // Build a list of CUs used.
2493 std::vector<DwarfCompileUnit *> CUs;
2494 for (const auto &it : Spans) {
2495 DwarfCompileUnit *CU = it.first;
2499 // Sort the CU list (again, to ensure consistent output order).
2500 std::sort(CUs.begin(), CUs.end(), [](const DwarfUnit *A, const DwarfUnit *B) {
2501 return A->getUniqueID() < B->getUniqueID();
2504 // Emit an arange table for each CU we used.
2505 for (DwarfCompileUnit *CU : CUs) {
2506 std::vector<ArangeSpan> &List = Spans[CU];
2508 // Emit size of content not including length itself.
2509 unsigned ContentSize =
2510 sizeof(int16_t) + // DWARF ARange version number
2511 sizeof(int32_t) + // Offset of CU in the .debug_info section
2512 sizeof(int8_t) + // Pointer Size (in bytes)
2513 sizeof(int8_t); // Segment Size (in bytes)
2515 unsigned TupleSize = PtrSize * 2;
2517 // 7.20 in the Dwarf specs requires the table to be aligned to a tuple.
2519 OffsetToAlignment(sizeof(int32_t) + ContentSize, TupleSize);
2521 ContentSize += Padding;
2522 ContentSize += (List.size() + 1) * TupleSize;
2524 // For each compile unit, write the list of spans it covers.
2525 Asm->OutStreamer.AddComment("Length of ARange Set");
2526 Asm->EmitInt32(ContentSize);
2527 Asm->OutStreamer.AddComment("DWARF Arange version number");
2528 Asm->EmitInt16(dwarf::DW_ARANGES_VERSION);
2529 Asm->OutStreamer.AddComment("Offset Into Debug Info Section");
2530 Asm->EmitSectionOffset(CU->getLocalLabelBegin(), CU->getLocalSectionSym());
2531 Asm->OutStreamer.AddComment("Address Size (in bytes)");
2532 Asm->EmitInt8(PtrSize);
2533 Asm->OutStreamer.AddComment("Segment Size (in bytes)");
2536 Asm->OutStreamer.EmitFill(Padding, 0xff);
2538 for (const ArangeSpan &Span : List) {
2539 Asm->EmitLabelReference(Span.Start, PtrSize);
2541 // Calculate the size as being from the span start to it's end.
2543 Asm->EmitLabelDifference(Span.End, Span.Start, PtrSize);
2545 // For symbols without an end marker (e.g. common), we
2546 // write a single arange entry containing just that one symbol.
2547 uint64_t Size = SymSize[Span.Start];
2551 Asm->OutStreamer.EmitIntValue(Size, PtrSize);
2555 Asm->OutStreamer.AddComment("ARange terminator");
2556 Asm->OutStreamer.EmitIntValue(0, PtrSize);
2557 Asm->OutStreamer.EmitIntValue(0, PtrSize);
2561 // Emit visible names into a debug ranges section.
2562 void DwarfDebug::emitDebugRanges() {
2563 // Start the dwarf ranges section.
2564 Asm->OutStreamer.SwitchSection(
2565 Asm->getObjFileLowering().getDwarfRangesSection());
2567 // Size for our labels.
2568 unsigned char Size = Asm->getDataLayout().getPointerSize();
2570 // Grab the specific ranges for the compile units in the module.
2571 for (const auto &I : CUMap) {
2572 DwarfCompileUnit *TheCU = I.second;
2574 // Emit a symbol so we can find the beginning of our ranges.
2575 Asm->OutStreamer.EmitLabel(TheCU->getLabelRange());
2577 // Iterate over the misc ranges for the compile units in the module.
2578 for (const RangeSpanList &List : TheCU->getRangeLists()) {
2579 // Emit our symbol so we can find the beginning of the range.
2580 Asm->OutStreamer.EmitLabel(List.getSym());
2582 for (const RangeSpan &Range : List.getRanges()) {
2583 const MCSymbol *Begin = Range.getStart();
2584 const MCSymbol *End = Range.getEnd();
2585 assert(Begin && "Range without a begin symbol?");
2586 assert(End && "Range without an end symbol?");
2587 Asm->OutStreamer.EmitSymbolValue(Begin, Size);
2588 Asm->OutStreamer.EmitSymbolValue(End, Size);
2591 // And terminate the list with two 0 values.
2592 Asm->OutStreamer.EmitIntValue(0, Size);
2593 Asm->OutStreamer.EmitIntValue(0, Size);
2596 // Now emit a range for the CU itself.
2597 if (TheCU->getRanges().size() > 1) {
2598 Asm->OutStreamer.EmitLabel(
2599 Asm->GetTempSymbol("cu_ranges", TheCU->getUniqueID()));
2600 for (const RangeSpan &Range : TheCU->getRanges()) {
2601 const MCSymbol *Begin = Range.getStart();
2602 const MCSymbol *End = Range.getEnd();
2603 assert(Begin && "Range without a begin symbol?");
2604 assert(End && "Range without an end symbol?");
2605 Asm->OutStreamer.EmitSymbolValue(Begin, Size);
2606 Asm->OutStreamer.EmitSymbolValue(End, Size);
2608 // And terminate the list with two 0 values.
2609 Asm->OutStreamer.EmitIntValue(0, Size);
2610 Asm->OutStreamer.EmitIntValue(0, Size);
2615 // DWARF5 Experimental Separate Dwarf emitters.
2617 void DwarfDebug::initSkeletonUnit(const DwarfUnit *U, DIE *Die,
2619 NewU->addLocalString(Die, dwarf::DW_AT_GNU_dwo_name,
2620 U->getCUNode().getSplitDebugFilename());
2622 // Relocate to the beginning of the addr_base section, else 0 for the
2623 // beginning of the one for this compile unit.
2624 if (Asm->MAI->doesDwarfUseRelocationsAcrossSections())
2625 NewU->addSectionLabel(Die, dwarf::DW_AT_GNU_addr_base, DwarfAddrSectionSym);
2627 NewU->addSectionOffset(Die, dwarf::DW_AT_GNU_addr_base, 0);
2629 if (!CompilationDir.empty())
2630 NewU->addLocalString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
2632 addGnuPubAttributes(NewU, Die);
2634 SkeletonHolder.addUnit(NewU);
2637 // This DIE has the following attributes: DW_AT_comp_dir, DW_AT_stmt_list,
2638 // DW_AT_low_pc, DW_AT_high_pc, DW_AT_ranges, DW_AT_dwo_name, DW_AT_dwo_id,
2639 // DW_AT_ranges_base, DW_AT_addr_base.
2640 // TODO: Implement DW_AT_ranges_base.
2641 DwarfCompileUnit *DwarfDebug::constructSkeletonCU(const DwarfCompileUnit *CU) {
2643 DIE *Die = new DIE(dwarf::DW_TAG_compile_unit);
2644 DwarfCompileUnit *NewCU = new DwarfCompileUnit(
2645 CU->getUniqueID(), Die, CU->getCUNode(), Asm, this, &SkeletonHolder);
2646 NewCU->initSection(Asm->getObjFileLowering().getDwarfInfoSection(),
2647 DwarfInfoSectionSym);
2649 NewCU->initStmtList(DwarfLineSectionSym);
2651 initSkeletonUnit(CU, Die, NewCU);
2656 // This DIE has the following attributes: DW_AT_comp_dir, DW_AT_dwo_name,
2658 DwarfTypeUnit *DwarfDebug::constructSkeletonTU(DwarfTypeUnit *TU) {
2659 DwarfCompileUnit &CU = static_cast<DwarfCompileUnit &>(
2660 *SkeletonHolder.getUnits()[TU->getCU().getUniqueID()]);
2662 DIE *Die = new DIE(dwarf::DW_TAG_type_unit);
2663 DwarfTypeUnit *NewTU =
2664 new DwarfTypeUnit(TU->getUniqueID(), Die, CU, Asm, this, &SkeletonHolder);
2665 NewTU->setTypeSignature(TU->getTypeSignature());
2666 NewTU->setType(NULL);
2668 Asm->getObjFileLowering().getDwarfTypesSection(TU->getTypeSignature()));
2670 initSkeletonUnit(TU, Die, NewTU);
2674 // Emit the .debug_info.dwo section for separated dwarf. This contains the
2675 // compile units that would normally be in debug_info.
2676 void DwarfDebug::emitDebugInfoDWO() {
2677 assert(useSplitDwarf() && "No split dwarf debug info?");
2678 InfoHolder.emitUnits(this,
2679 Asm->getObjFileLowering().getDwarfAbbrevDWOSection(),
2680 DwarfAbbrevDWOSectionSym);
2683 // Emit the .debug_abbrev.dwo section for separated dwarf. This contains the
2684 // abbreviations for the .debug_info.dwo section.
2685 void DwarfDebug::emitDebugAbbrevDWO() {
2686 assert(useSplitDwarf() && "No split dwarf?");
2687 InfoHolder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevDWOSection());
2690 void DwarfDebug::emitDebugLineDWO() {
2691 assert(useSplitDwarf() && "No split dwarf?");
2692 Asm->OutStreamer.SwitchSection(
2693 Asm->getObjFileLowering().getDwarfLineDWOSection());
2694 SplitTypeUnitFileTable.Emit(Asm->OutStreamer);
2697 // Emit the .debug_str.dwo section for separated dwarf. This contains the
2698 // string section and is identical in format to traditional .debug_str
2700 void DwarfDebug::emitDebugStrDWO() {
2701 assert(useSplitDwarf() && "No split dwarf?");
2702 const MCSection *OffSec =
2703 Asm->getObjFileLowering().getDwarfStrOffDWOSection();
2704 const MCSymbol *StrSym = DwarfStrSectionSym;
2705 InfoHolder.emitStrings(Asm->getObjFileLowering().getDwarfStrDWOSection(),
2709 MCDwarfDwoLineTable *DwarfDebug::getDwoLineTable(const DwarfCompileUnit &CU) {
2710 if (!useSplitDwarf())
2713 SplitTypeUnitFileTable.setCompilationDir(CU.getCUNode().getDirectory());
2714 return &SplitTypeUnitFileTable;
2717 void DwarfDebug::addDwarfTypeUnitType(DwarfCompileUnit &CU,
2718 StringRef Identifier, DIE *RefDie,
2719 DICompositeType CTy) {
2720 // Flag the type unit reference as a declaration so that if it contains
2721 // members (implicit special members, static data member definitions, member
2722 // declarations for definitions in this CU, etc) consumers don't get confused
2723 // and think this is a full definition.
2724 CU.addFlag(RefDie, dwarf::DW_AT_declaration);
2726 const DwarfTypeUnit *&TU = DwarfTypeUnits[CTy];
2728 CU.addDIETypeSignature(RefDie, *TU);
2732 DIE *UnitDie = new DIE(dwarf::DW_TAG_type_unit);
2733 DwarfTypeUnit *NewTU =
2734 new DwarfTypeUnit(InfoHolder.getUnits().size(), UnitDie, CU, Asm, this,
2735 &InfoHolder, getDwoLineTable(CU));
2737 InfoHolder.addUnit(NewTU);
2739 NewTU->addUInt(UnitDie, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
2743 Hash.update(Identifier);
2744 // ... take the least significant 8 bytes and return those. Our MD5
2745 // implementation always returns its results in little endian, swap bytes
2747 MD5::MD5Result Result;
2749 uint64_t Signature = *reinterpret_cast<support::ulittle64_t *>(Result + 8);
2750 NewTU->setTypeSignature(Signature);
2751 if (useSplitDwarf())
2752 NewTU->setSkeleton(constructSkeletonTU(NewTU));
2754 CU.applyStmtList(*UnitDie);
2756 NewTU->setType(NewTU->createTypeDIE(CTy));
2760 ? Asm->getObjFileLowering().getDwarfTypesDWOSection(Signature)
2761 : Asm->getObjFileLowering().getDwarfTypesSection(Signature));
2763 CU.addDIETypeSignature(RefDie, *NewTU);
2766 void DwarfDebug::attachLowHighPC(DwarfCompileUnit *Unit, DIE *D,
2767 MCSymbol *Begin, MCSymbol *End) {
2768 Unit->addLabelAddress(D, dwarf::DW_AT_low_pc, Begin);
2769 if (DwarfVersion < 4)
2770 Unit->addLabelAddress(D, dwarf::DW_AT_high_pc, End);
2772 Unit->addLabelDelta(D, dwarf::DW_AT_high_pc, End, Begin);