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/Endian.h"
40 #include "llvm/Support/ErrorHandling.h"
41 #include "llvm/Support/FormattedStream.h"
42 #include "llvm/Support/LEB128.h"
43 #include "llvm/Support/MD5.h"
44 #include "llvm/Support/Path.h"
45 #include "llvm/Support/Timer.h"
46 #include "llvm/Target/TargetFrameLowering.h"
47 #include "llvm/Target/TargetLoweringObjectFile.h"
48 #include "llvm/Target/TargetMachine.h"
49 #include "llvm/Target/TargetOptions.h"
50 #include "llvm/Target/TargetRegisterInfo.h"
51 #include "llvm/Target/TargetSubtargetInfo.h"
54 #define DEBUG_TYPE "dwarfdebug"
57 DisableDebugInfoPrinting("disable-debug-info-print", cl::Hidden,
58 cl::desc("Disable debug info printing"));
60 static cl::opt<bool> UnknownLocations(
61 "use-unknown-locations", cl::Hidden,
62 cl::desc("Make an absence of debug location information explicit."),
66 GenerateGnuPubSections("generate-gnu-dwarf-pub-sections", cl::Hidden,
67 cl::desc("Generate GNU-style pubnames and pubtypes"),
70 static cl::opt<bool> GenerateARangeSection("generate-arange-section",
72 cl::desc("Generate dwarf aranges"),
76 enum DefaultOnOff { Default, Enable, Disable };
79 static cl::opt<DefaultOnOff>
80 DwarfAccelTables("dwarf-accel-tables", cl::Hidden,
81 cl::desc("Output prototype dwarf accelerator tables."),
82 cl::values(clEnumVal(Default, "Default for platform"),
83 clEnumVal(Enable, "Enabled"),
84 clEnumVal(Disable, "Disabled"), clEnumValEnd),
87 static cl::opt<DefaultOnOff>
88 SplitDwarf("split-dwarf", cl::Hidden,
89 cl::desc("Output DWARF5 split debug info."),
90 cl::values(clEnumVal(Default, "Default for platform"),
91 clEnumVal(Enable, "Enabled"),
92 clEnumVal(Disable, "Disabled"), clEnumValEnd),
95 static cl::opt<DefaultOnOff>
96 DwarfPubSections("generate-dwarf-pub-sections", cl::Hidden,
97 cl::desc("Generate DWARF pubnames and pubtypes sections"),
98 cl::values(clEnumVal(Default, "Default for platform"),
99 clEnumVal(Enable, "Enabled"),
100 clEnumVal(Disable, "Disabled"), clEnumValEnd),
103 static const char *const DWARFGroupName = "DWARF Emission";
104 static const char *const DbgTimerName = "DWARF Debug Writer";
106 //===----------------------------------------------------------------------===//
108 /// resolve - Look in the DwarfDebug map for the MDNode that
109 /// corresponds to the reference.
110 template <typename T> T DbgVariable::resolve(DIRef<T> Ref) const {
111 return DD->resolve(Ref);
114 bool DbgVariable::isBlockByrefVariable() const {
115 assert(Var.isVariable() && "Invalid complex DbgVariable!");
116 return Var.isBlockByrefVariable(DD->getTypeIdentifierMap());
119 DIType DbgVariable::getType() const {
120 DIType Ty = Var.getType().resolve(DD->getTypeIdentifierMap());
121 // FIXME: isBlockByrefVariable should be reformulated in terms of complex
122 // addresses instead.
123 if (Var.isBlockByrefVariable(DD->getTypeIdentifierMap())) {
124 /* Byref variables, in Blocks, are declared by the programmer as
125 "SomeType VarName;", but the compiler creates a
126 __Block_byref_x_VarName struct, and gives the variable VarName
127 either the struct, or a pointer to the struct, as its type. This
128 is necessary for various behind-the-scenes things the compiler
129 needs to do with by-reference variables in blocks.
131 However, as far as the original *programmer* is concerned, the
132 variable should still have type 'SomeType', as originally declared.
134 The following function dives into the __Block_byref_x_VarName
135 struct to find the original type of the variable. This will be
136 passed back to the code generating the type for the Debug
137 Information Entry for the variable 'VarName'. 'VarName' will then
138 have the original type 'SomeType' in its debug information.
140 The original type 'SomeType' will be the type of the field named
141 'VarName' inside the __Block_byref_x_VarName struct.
143 NOTE: In order for this to not completely fail on the debugger
144 side, the Debug Information Entry for the variable VarName needs to
145 have a DW_AT_location that tells the debugger how to unwind through
146 the pointers and __Block_byref_x_VarName struct to find the actual
147 value of the variable. The function addBlockByrefType does this. */
149 uint16_t tag = Ty.getTag();
151 if (tag == dwarf::DW_TAG_pointer_type)
152 subType = resolve(DIDerivedType(Ty).getTypeDerivedFrom());
154 DIArray Elements = DICompositeType(subType).getElements();
155 for (unsigned i = 0, N = Elements.getNumElements(); i < N; ++i) {
156 DIDerivedType DT(Elements.getElement(i));
157 if (getName() == DT.getName())
158 return (resolve(DT.getTypeDerivedFrom()));
164 static LLVM_CONSTEXPR DwarfAccelTable::Atom TypeAtoms[] = {
165 DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset, dwarf::DW_FORM_data4),
166 DwarfAccelTable::Atom(dwarf::DW_ATOM_die_tag, dwarf::DW_FORM_data2),
167 DwarfAccelTable::Atom(dwarf::DW_ATOM_type_flags, dwarf::DW_FORM_data1)};
169 DwarfDebug::DwarfDebug(AsmPrinter *A, Module *M)
170 : Asm(A), MMI(Asm->MMI), FirstCU(nullptr), PrevLabel(nullptr),
171 GlobalRangeCount(0), InfoHolder(A, "info_string", DIEValueAllocator),
172 UsedNonDefaultText(false),
173 SkeletonHolder(A, "skel_string", DIEValueAllocator),
174 AccelNames(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
175 dwarf::DW_FORM_data4)),
176 AccelObjC(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
177 dwarf::DW_FORM_data4)),
178 AccelNamespace(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
179 dwarf::DW_FORM_data4)),
180 AccelTypes(TypeAtoms) {
182 DwarfInfoSectionSym = DwarfAbbrevSectionSym = DwarfStrSectionSym = nullptr;
183 DwarfDebugRangeSectionSym = DwarfDebugLocSectionSym = nullptr;
184 DwarfLineSectionSym = nullptr;
185 DwarfAddrSectionSym = nullptr;
186 DwarfAbbrevDWOSectionSym = DwarfStrDWOSectionSym = nullptr;
187 FunctionBeginSym = FunctionEndSym = nullptr;
191 // Turn on accelerator tables for Darwin by default, pubnames by
192 // default for non-Darwin, and handle split dwarf.
193 bool IsDarwin = Triple(A->getTargetTriple()).isOSDarwin();
195 if (DwarfAccelTables == Default)
196 HasDwarfAccelTables = IsDarwin;
198 HasDwarfAccelTables = DwarfAccelTables == Enable;
200 if (SplitDwarf == Default)
201 HasSplitDwarf = false;
203 HasSplitDwarf = SplitDwarf == Enable;
205 if (DwarfPubSections == Default)
206 HasDwarfPubSections = !IsDarwin;
208 HasDwarfPubSections = DwarfPubSections == Enable;
210 unsigned DwarfVersionNumber = Asm->TM.Options.MCOptions.DwarfVersion;
211 DwarfVersion = DwarfVersionNumber ? DwarfVersionNumber
212 : MMI->getModule()->getDwarfVersion();
214 Asm->OutStreamer.getContext().setDwarfVersion(DwarfVersion);
217 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
222 // Define out of line so we don't have to include DwarfUnit.h in DwarfDebug.h.
223 DwarfDebug::~DwarfDebug() { }
225 // Switch to the specified MCSection and emit an assembler
226 // temporary label to it if SymbolStem is specified.
227 static MCSymbol *emitSectionSym(AsmPrinter *Asm, const MCSection *Section,
228 const char *SymbolStem = nullptr) {
229 Asm->OutStreamer.SwitchSection(Section);
233 MCSymbol *TmpSym = Asm->GetTempSymbol(SymbolStem);
234 Asm->OutStreamer.EmitLabel(TmpSym);
238 static bool isObjCClass(StringRef Name) {
239 return Name.startswith("+") || Name.startswith("-");
242 static bool hasObjCCategory(StringRef Name) {
243 if (!isObjCClass(Name))
246 return Name.find(") ") != StringRef::npos;
249 static void getObjCClassCategory(StringRef In, StringRef &Class,
250 StringRef &Category) {
251 if (!hasObjCCategory(In)) {
252 Class = In.slice(In.find('[') + 1, In.find(' '));
257 Class = In.slice(In.find('[') + 1, In.find('('));
258 Category = In.slice(In.find('[') + 1, In.find(' '));
262 static StringRef getObjCMethodName(StringRef In) {
263 return In.slice(In.find(' ') + 1, In.find(']'));
266 // Helper for sorting sections into a stable output order.
267 static bool SectionSort(const MCSection *A, const MCSection *B) {
268 std::string LA = (A ? A->getLabelBeginName() : "");
269 std::string LB = (B ? B->getLabelBeginName() : "");
273 // Add the various names to the Dwarf accelerator table names.
274 // TODO: Determine whether or not we should add names for programs
275 // that do not have a DW_AT_name or DW_AT_linkage_name field - this
276 // is only slightly different than the lookup of non-standard ObjC names.
277 void DwarfDebug::addSubprogramNames(DISubprogram SP, DIE &Die) {
278 if (!SP.isDefinition())
280 addAccelName(SP.getName(), Die);
282 // If the linkage name is different than the name, go ahead and output
283 // that as well into the name table.
284 if (SP.getLinkageName() != "" && SP.getName() != SP.getLinkageName())
285 addAccelName(SP.getLinkageName(), Die);
287 // If this is an Objective-C selector name add it to the ObjC accelerator
289 if (isObjCClass(SP.getName())) {
290 StringRef Class, Category;
291 getObjCClassCategory(SP.getName(), Class, Category);
292 addAccelObjC(Class, Die);
294 addAccelObjC(Category, Die);
295 // Also add the base method name to the name table.
296 addAccelName(getObjCMethodName(SP.getName()), Die);
300 /// isSubprogramContext - Return true if Context is either a subprogram
301 /// or another context nested inside a subprogram.
302 bool DwarfDebug::isSubprogramContext(const MDNode *Context) {
305 DIDescriptor D(Context);
306 if (D.isSubprogram())
309 return isSubprogramContext(resolve(DIType(Context).getContext()));
313 // Find DIE for the given subprogram and attach appropriate DW_AT_low_pc
314 // and DW_AT_high_pc attributes. If there are global variables in this
315 // scope then create and insert DIEs for these variables.
316 DIE &DwarfDebug::updateSubprogramScopeDIE(DwarfCompileUnit &SPCU,
318 DIE *SPDie = SPCU.getOrCreateSubprogramDIE(SP);
320 attachLowHighPC(SPCU, *SPDie, FunctionBeginSym, FunctionEndSym);
322 const TargetRegisterInfo *RI = Asm->TM.getSubtargetImpl()->getRegisterInfo();
323 MachineLocation Location(RI->getFrameRegister(*Asm->MF));
324 SPCU.addAddress(*SPDie, dwarf::DW_AT_frame_base, Location);
326 // Add name to the name table, we do this here because we're guaranteed
327 // to have concrete versions of our DW_TAG_subprogram nodes.
328 addSubprogramNames(SP, *SPDie);
333 /// Check whether we should create a DIE for the given Scope, return true
334 /// if we don't create a DIE (the corresponding DIE is null).
335 bool DwarfDebug::isLexicalScopeDIENull(LexicalScope *Scope) {
336 if (Scope->isAbstractScope())
339 // We don't create a DIE if there is no Range.
340 const SmallVectorImpl<InsnRange> &Ranges = Scope->getRanges();
344 if (Ranges.size() > 1)
347 // We don't create a DIE if we have a single Range and the end label
349 return !getLabelAfterInsn(Ranges.front().second);
352 static void addSectionLabel(AsmPrinter &Asm, DwarfUnit &U, DIE &D,
353 dwarf::Attribute A, const MCSymbol *L,
354 const MCSymbol *Sec) {
355 if (Asm.MAI->doesDwarfUseRelocationsAcrossSections())
356 U.addSectionLabel(D, A, L);
358 U.addSectionDelta(D, A, L, Sec);
361 void DwarfDebug::addScopeRangeList(DwarfCompileUnit &TheCU, DIE &ScopeDIE,
362 const SmallVectorImpl<InsnRange> &Range) {
363 // Emit offset in .debug_range as a relocatable label. emitDIE will handle
364 // emitting it appropriately.
365 MCSymbol *RangeSym = Asm->GetTempSymbol("debug_ranges", GlobalRangeCount++);
367 // Under fission, ranges are specified by constant offsets relative to the
368 // CU's DW_AT_GNU_ranges_base.
370 TheCU.addSectionDelta(ScopeDIE, dwarf::DW_AT_ranges, RangeSym,
371 DwarfDebugRangeSectionSym);
373 addSectionLabel(*Asm, TheCU, ScopeDIE, dwarf::DW_AT_ranges, RangeSym,
374 DwarfDebugRangeSectionSym);
376 RangeSpanList List(RangeSym);
377 for (const InsnRange &R : Range) {
378 RangeSpan Span(getLabelBeforeInsn(R.first), getLabelAfterInsn(R.second));
379 List.addRange(std::move(Span));
382 // Add the range list to the set of ranges to be emitted.
383 TheCU.addRangeList(std::move(List));
386 void DwarfDebug::attachRangesOrLowHighPC(DwarfCompileUnit &TheCU, DIE &Die,
387 const SmallVectorImpl<InsnRange> &Ranges) {
388 assert(!Ranges.empty());
389 if (Ranges.size() == 1)
390 attachLowHighPC(TheCU, Die, getLabelBeforeInsn(Ranges.front().first),
391 getLabelAfterInsn(Ranges.front().second));
393 addScopeRangeList(TheCU, Die, Ranges);
396 // Construct new DW_TAG_lexical_block for this scope and attach
397 // DW_AT_low_pc/DW_AT_high_pc labels.
399 DwarfDebug::constructLexicalScopeDIE(DwarfCompileUnit &TheCU,
400 LexicalScope *Scope) {
401 if (isLexicalScopeDIENull(Scope))
404 auto ScopeDIE = make_unique<DIE>(dwarf::DW_TAG_lexical_block);
405 if (Scope->isAbstractScope())
408 attachRangesOrLowHighPC(TheCU, *ScopeDIE, Scope->getRanges());
413 // This scope represents inlined body of a function. Construct DIE to
414 // represent this concrete inlined copy of the function.
416 DwarfDebug::constructInlinedScopeDIE(DwarfCompileUnit &TheCU,
417 LexicalScope *Scope) {
418 assert(Scope->getScopeNode());
419 DIScope DS(Scope->getScopeNode());
420 DISubprogram InlinedSP = getDISubprogram(DS);
421 // Find the subprogram's DwarfCompileUnit in the SPMap in case the subprogram
422 // was inlined from another compile unit.
423 DIE *OriginDIE = AbstractSPDies[InlinedSP];
424 assert(OriginDIE && "Unable to find original DIE for an inlined subprogram.");
426 auto ScopeDIE = make_unique<DIE>(dwarf::DW_TAG_inlined_subroutine);
427 TheCU.addDIEEntry(*ScopeDIE, dwarf::DW_AT_abstract_origin, *OriginDIE);
429 attachRangesOrLowHighPC(TheCU, *ScopeDIE, Scope->getRanges());
431 InlinedSubprogramDIEs.insert(OriginDIE);
433 // Add the call site information to the DIE.
434 DILocation DL(Scope->getInlinedAt());
435 TheCU.addUInt(*ScopeDIE, dwarf::DW_AT_call_file, None,
436 TheCU.getOrCreateSourceID(DL.getFilename(), DL.getDirectory()));
437 TheCU.addUInt(*ScopeDIE, dwarf::DW_AT_call_line, None, DL.getLineNumber());
439 // Add name to the name table, we do this here because we're guaranteed
440 // to have concrete versions of our DW_TAG_inlined_subprogram nodes.
441 addSubprogramNames(InlinedSP, *ScopeDIE);
446 static std::unique_ptr<DIE> constructVariableDIE(DwarfCompileUnit &TheCU,
448 const LexicalScope &Scope,
449 DIE *&ObjectPointer) {
450 auto Var = TheCU.constructVariableDIE(DV, Scope.isAbstractScope());
451 if (DV.isObjectPointer())
452 ObjectPointer = Var.get();
456 DIE *DwarfDebug::createScopeChildrenDIE(
457 DwarfCompileUnit &TheCU, LexicalScope *Scope,
458 SmallVectorImpl<std::unique_ptr<DIE>> &Children,
459 unsigned *ChildScopeCount) {
460 DIE *ObjectPointer = nullptr;
462 for (DbgVariable *DV : ScopeVariables.lookup(Scope))
463 Children.push_back(constructVariableDIE(TheCU, *DV, *Scope, ObjectPointer));
465 unsigned ChildCountWithoutScopes = Children.size();
467 for (LexicalScope *LS : Scope->getChildren())
468 constructScopeDIE(TheCU, LS, Children);
471 *ChildScopeCount = Children.size() - ChildCountWithoutScopes;
473 return ObjectPointer;
476 DIE *DwarfDebug::createAndAddScopeChildren(DwarfCompileUnit &TheCU,
477 LexicalScope *Scope, DIE &ScopeDIE) {
478 // We create children when the scope DIE is not null.
479 SmallVector<std::unique_ptr<DIE>, 8> Children;
480 DIE *ObjectPointer = createScopeChildrenDIE(TheCU, Scope, Children);
483 for (auto &I : Children)
484 ScopeDIE.addChild(std::move(I));
486 return ObjectPointer;
489 void DwarfDebug::constructAbstractSubprogramScopeDIE(DwarfCompileUnit &TheCU,
490 LexicalScope *Scope) {
491 assert(Scope && Scope->getScopeNode());
492 assert(Scope->isAbstractScope());
493 assert(!Scope->getInlinedAt());
495 DISubprogram SP(Scope->getScopeNode());
497 ProcessedSPNodes.insert(SP);
499 DIE *&AbsDef = AbstractSPDies[SP];
503 // Find the subprogram's DwarfCompileUnit in the SPMap in case the subprogram
504 // was inlined from another compile unit.
505 DwarfCompileUnit &SPCU = *SPMap[SP];
508 // Some of this is duplicated from DwarfUnit::getOrCreateSubprogramDIE, with
509 // the important distinction that the DIDescriptor is not associated with the
510 // DIE (since the DIDescriptor will be associated with the concrete DIE, if
511 // any). It could be refactored to some common utility function.
512 if (DISubprogram SPDecl = SP.getFunctionDeclaration()) {
513 ContextDIE = &SPCU.getUnitDie();
514 SPCU.getOrCreateSubprogramDIE(SPDecl);
516 ContextDIE = SPCU.getOrCreateContextDIE(resolve(SP.getContext()));
518 // Passing null as the associated DIDescriptor because the abstract definition
519 // shouldn't be found by lookup.
520 AbsDef = &SPCU.createAndAddDIE(dwarf::DW_TAG_subprogram, *ContextDIE,
522 SPCU.applySubprogramAttributesToDefinition(SP, *AbsDef);
524 SPCU.addUInt(*AbsDef, dwarf::DW_AT_inline, None, dwarf::DW_INL_inlined);
525 if (DIE *ObjectPointer = createAndAddScopeChildren(SPCU, Scope, *AbsDef))
526 SPCU.addDIEEntry(*AbsDef, dwarf::DW_AT_object_pointer, *ObjectPointer);
529 DIE &DwarfDebug::constructSubprogramScopeDIE(DwarfCompileUnit &TheCU,
530 LexicalScope *Scope) {
531 assert(Scope && Scope->getScopeNode());
532 assert(!Scope->getInlinedAt());
533 assert(!Scope->isAbstractScope());
534 DISubprogram Sub(Scope->getScopeNode());
536 assert(Sub.isSubprogram());
538 ProcessedSPNodes.insert(Sub);
540 DIE &ScopeDIE = updateSubprogramScopeDIE(TheCU, Sub);
542 // Collect arguments for current function.
543 assert(LScopes.isCurrentFunctionScope(Scope));
544 DIE *ObjectPointer = nullptr;
545 for (DbgVariable *ArgDV : CurrentFnArguments)
548 constructVariableDIE(TheCU, *ArgDV, *Scope, ObjectPointer));
550 // If this is a variadic function, add an unspecified parameter.
551 DITypeArray FnArgs = Sub.getType().getTypeArray();
552 // If we have a single element of null, it is a function that returns void.
553 // If we have more than one elements and the last one is null, it is a
554 // variadic function.
555 if (FnArgs.getNumElements() > 1 &&
556 !FnArgs.getElement(FnArgs.getNumElements() - 1))
557 ScopeDIE.addChild(make_unique<DIE>(dwarf::DW_TAG_unspecified_parameters));
559 // Collect lexical scope children first.
560 // ObjectPointer might be a local (non-argument) local variable if it's a
561 // block's synthetic this pointer.
562 if (DIE *BlockObjPtr = createAndAddScopeChildren(TheCU, Scope, ScopeDIE)) {
563 assert(!ObjectPointer && "multiple object pointers can't be described");
564 ObjectPointer = BlockObjPtr;
568 TheCU.addDIEEntry(ScopeDIE, dwarf::DW_AT_object_pointer, *ObjectPointer);
573 // Construct a DIE for this scope.
574 void DwarfDebug::constructScopeDIE(
575 DwarfCompileUnit &TheCU, LexicalScope *Scope,
576 SmallVectorImpl<std::unique_ptr<DIE>> &FinalChildren) {
577 if (!Scope || !Scope->getScopeNode())
580 DIScope DS(Scope->getScopeNode());
582 assert((Scope->getInlinedAt() || !DS.isSubprogram()) &&
583 "Only handle inlined subprograms here, use "
584 "constructSubprogramScopeDIE for non-inlined "
587 SmallVector<std::unique_ptr<DIE>, 8> Children;
589 // We try to create the scope DIE first, then the children DIEs. This will
590 // avoid creating un-used children then removing them later when we find out
591 // the scope DIE is null.
592 std::unique_ptr<DIE> ScopeDIE;
593 if (Scope->getParent() && DS.isSubprogram()) {
594 ScopeDIE = constructInlinedScopeDIE(TheCU, Scope);
597 // We create children when the scope DIE is not null.
598 createScopeChildrenDIE(TheCU, Scope, Children);
600 // Early exit when we know the scope DIE is going to be null.
601 if (isLexicalScopeDIENull(Scope))
604 unsigned ChildScopeCount;
606 // We create children here when we know the scope DIE is not going to be
607 // null and the children will be added to the scope DIE.
608 createScopeChildrenDIE(TheCU, Scope, Children, &ChildScopeCount);
610 // There is no need to emit empty lexical block DIE.
611 std::pair<ImportedEntityMap::const_iterator,
612 ImportedEntityMap::const_iterator> Range =
613 std::equal_range(ScopesWithImportedEntities.begin(),
614 ScopesWithImportedEntities.end(),
615 std::pair<const MDNode *, const MDNode *>(DS, nullptr),
617 for (ImportedEntityMap::const_iterator i = Range.first; i != Range.second;
620 constructImportedEntityDIE(TheCU, DIImportedEntity(i->second)));
621 // If there are only other scopes as children, put them directly in the
622 // parent instead, as this scope would serve no purpose.
623 if (Children.size() == ChildScopeCount) {
624 FinalChildren.insert(FinalChildren.end(),
625 std::make_move_iterator(Children.begin()),
626 std::make_move_iterator(Children.end()));
629 ScopeDIE = constructLexicalScopeDIE(TheCU, Scope);
630 assert(ScopeDIE && "Scope DIE should not be null.");
634 for (auto &I : Children)
635 ScopeDIE->addChild(std::move(I));
637 FinalChildren.push_back(std::move(ScopeDIE));
640 void DwarfDebug::addGnuPubAttributes(DwarfUnit &U, DIE &D) const {
641 if (!GenerateGnuPubSections)
644 U.addFlag(D, dwarf::DW_AT_GNU_pubnames);
647 // Create new DwarfCompileUnit for the given metadata node with tag
648 // DW_TAG_compile_unit.
649 DwarfCompileUnit &DwarfDebug::constructDwarfCompileUnit(DICompileUnit DIUnit) {
650 StringRef FN = DIUnit.getFilename();
651 CompilationDir = DIUnit.getDirectory();
653 auto OwnedUnit = make_unique<DwarfCompileUnit>(
654 InfoHolder.getUnits().size(), DIUnit, Asm, this, &InfoHolder);
655 DwarfCompileUnit &NewCU = *OwnedUnit;
656 DIE &Die = NewCU.getUnitDie();
657 InfoHolder.addUnit(std::move(OwnedUnit));
659 // LTO with assembly output shares a single line table amongst multiple CUs.
660 // To avoid the compilation directory being ambiguous, let the line table
661 // explicitly describe the directory of all files, never relying on the
662 // compilation directory.
663 if (!Asm->OutStreamer.hasRawTextSupport() || SingleCU)
664 Asm->OutStreamer.getContext().setMCLineTableCompilationDir(
665 NewCU.getUniqueID(), CompilationDir);
667 NewCU.addString(Die, dwarf::DW_AT_producer, DIUnit.getProducer());
668 NewCU.addUInt(Die, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
669 DIUnit.getLanguage());
670 NewCU.addString(Die, dwarf::DW_AT_name, FN);
672 if (!useSplitDwarf()) {
673 NewCU.initStmtList(DwarfLineSectionSym);
675 // If we're using split dwarf the compilation dir is going to be in the
676 // skeleton CU and so we don't need to duplicate it here.
677 if (!CompilationDir.empty())
678 NewCU.addString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
680 addGnuPubAttributes(NewCU, Die);
683 if (DIUnit.isOptimized())
684 NewCU.addFlag(Die, dwarf::DW_AT_APPLE_optimized);
686 StringRef Flags = DIUnit.getFlags();
688 NewCU.addString(Die, dwarf::DW_AT_APPLE_flags, Flags);
690 if (unsigned RVer = DIUnit.getRunTimeVersion())
691 NewCU.addUInt(Die, dwarf::DW_AT_APPLE_major_runtime_vers,
692 dwarf::DW_FORM_data1, RVer);
697 if (useSplitDwarf()) {
698 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoDWOSection(),
699 DwarfInfoDWOSectionSym);
700 NewCU.setSkeleton(constructSkeletonCU(NewCU));
702 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoSection(),
703 DwarfInfoSectionSym);
705 CUMap.insert(std::make_pair(DIUnit, &NewCU));
706 CUDieMap.insert(std::make_pair(&Die, &NewCU));
710 void DwarfDebug::constructAndAddImportedEntityDIE(DwarfCompileUnit &TheCU,
712 DIImportedEntity Module(N);
713 assert(Module.Verify());
714 if (DIE *D = TheCU.getOrCreateContextDIE(Module.getContext()))
715 D->addChild(constructImportedEntityDIE(TheCU, Module));
719 DwarfDebug::constructImportedEntityDIE(DwarfCompileUnit &TheCU,
720 const DIImportedEntity &Module) {
721 assert(Module.Verify() &&
722 "Use one of the MDNode * overloads to handle invalid metadata");
723 std::unique_ptr<DIE> IMDie = make_unique<DIE>((dwarf::Tag)Module.getTag());
724 TheCU.insertDIE(Module, IMDie.get());
726 DIDescriptor Entity = resolve(Module.getEntity());
727 if (Entity.isNameSpace())
728 EntityDie = TheCU.getOrCreateNameSpace(DINameSpace(Entity));
729 else if (Entity.isSubprogram())
730 EntityDie = TheCU.getOrCreateSubprogramDIE(DISubprogram(Entity));
731 else if (Entity.isType())
732 EntityDie = TheCU.getOrCreateTypeDIE(DIType(Entity));
734 EntityDie = TheCU.getDIE(Entity);
736 TheCU.addSourceLine(*IMDie, Module.getLineNumber(),
737 Module.getContext().getFilename(),
738 Module.getContext().getDirectory());
739 TheCU.addDIEEntry(*IMDie, dwarf::DW_AT_import, *EntityDie);
740 StringRef Name = Module.getName();
742 TheCU.addString(*IMDie, dwarf::DW_AT_name, Name);
747 // Emit all Dwarf sections that should come prior to the content. Create
748 // global DIEs and emit initial debug info sections. This is invoked by
749 // the target AsmPrinter.
750 void DwarfDebug::beginModule() {
751 if (DisableDebugInfoPrinting)
754 const Module *M = MMI->getModule();
756 FunctionDIs = makeSubprogramMap(*M);
758 // If module has named metadata anchors then use them, otherwise scan the
759 // module using debug info finder to collect debug info.
760 NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
763 TypeIdentifierMap = generateDITypeIdentifierMap(CU_Nodes);
765 // Emit initial sections so we can reference labels later.
768 SingleCU = CU_Nodes->getNumOperands() == 1;
770 for (MDNode *N : CU_Nodes->operands()) {
771 DICompileUnit CUNode(N);
772 DwarfCompileUnit &CU = constructDwarfCompileUnit(CUNode);
773 DIArray ImportedEntities = CUNode.getImportedEntities();
774 for (unsigned i = 0, e = ImportedEntities.getNumElements(); i != e; ++i)
775 ScopesWithImportedEntities.push_back(std::make_pair(
776 DIImportedEntity(ImportedEntities.getElement(i)).getContext(),
777 ImportedEntities.getElement(i)));
778 std::sort(ScopesWithImportedEntities.begin(),
779 ScopesWithImportedEntities.end(), less_first());
780 DIArray GVs = CUNode.getGlobalVariables();
781 for (unsigned i = 0, e = GVs.getNumElements(); i != e; ++i)
782 CU.createGlobalVariableDIE(DIGlobalVariable(GVs.getElement(i)));
783 DIArray SPs = CUNode.getSubprograms();
784 for (unsigned i = 0, e = SPs.getNumElements(); i != e; ++i)
785 SPMap.insert(std::make_pair(SPs.getElement(i), &CU));
786 DIArray EnumTypes = CUNode.getEnumTypes();
787 for (unsigned i = 0, e = EnumTypes.getNumElements(); i != e; ++i) {
788 DIType Ty(EnumTypes.getElement(i));
789 // The enum types array by design contains pointers to
790 // MDNodes rather than DIRefs. Unique them here.
791 DIType UniqueTy(resolve(Ty.getRef()));
792 CU.getOrCreateTypeDIE(UniqueTy);
794 DIArray RetainedTypes = CUNode.getRetainedTypes();
795 for (unsigned i = 0, e = RetainedTypes.getNumElements(); i != e; ++i) {
796 DIType Ty(RetainedTypes.getElement(i));
797 // The retained types array by design contains pointers to
798 // MDNodes rather than DIRefs. Unique them here.
799 DIType UniqueTy(resolve(Ty.getRef()));
800 CU.getOrCreateTypeDIE(UniqueTy);
802 // Emit imported_modules last so that the relevant context is already
804 for (unsigned i = 0, e = ImportedEntities.getNumElements(); i != e; ++i)
805 constructAndAddImportedEntityDIE(CU, ImportedEntities.getElement(i));
808 // Tell MMI that we have debug info.
809 MMI->setDebugInfoAvailability(true);
811 // Prime section data.
812 SectionMap[Asm->getObjFileLowering().getTextSection()];
815 void DwarfDebug::finishVariableDefinitions() {
816 for (const auto &Var : ConcreteVariables) {
817 DIE *VariableDie = Var->getDIE();
819 // FIXME: Consider the time-space tradeoff of just storing the unit pointer
820 // in the ConcreteVariables list, rather than looking it up again here.
821 // DIE::getUnit isn't simple - it walks parent pointers, etc.
822 DwarfCompileUnit *Unit = lookupUnit(VariableDie->getUnit());
824 DbgVariable *AbsVar = getExistingAbstractVariable(Var->getVariable());
825 if (AbsVar && AbsVar->getDIE()) {
826 Unit->addDIEEntry(*VariableDie, dwarf::DW_AT_abstract_origin,
829 Unit->applyVariableAttributes(*Var, *VariableDie);
833 void DwarfDebug::finishSubprogramDefinitions() {
834 const Module *M = MMI->getModule();
836 NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
837 for (MDNode *N : CU_Nodes->operands()) {
838 DICompileUnit TheCU(N);
839 // Construct subprogram DIE and add variables DIEs.
840 DwarfCompileUnit *SPCU =
841 static_cast<DwarfCompileUnit *>(CUMap.lookup(TheCU));
842 DIArray Subprograms = TheCU.getSubprograms();
843 for (unsigned i = 0, e = Subprograms.getNumElements(); i != e; ++i) {
844 DISubprogram SP(Subprograms.getElement(i));
845 // Perhaps the subprogram is in another CU (such as due to comdat
846 // folding, etc), in which case ignore it here.
847 if (SPMap[SP] != SPCU)
849 DIE *D = SPCU->getDIE(SP);
850 if (DIE *AbsSPDIE = AbstractSPDies.lookup(SP)) {
852 // If this subprogram has an abstract definition, reference that
853 SPCU->addDIEEntry(*D, dwarf::DW_AT_abstract_origin, *AbsSPDIE);
856 // Lazily construct the subprogram if we didn't see either concrete or
857 // inlined versions during codegen.
858 D = SPCU->getOrCreateSubprogramDIE(SP);
859 // And attach the attributes
860 SPCU->applySubprogramAttributesToDefinition(SP, *D);
867 // Collect info for variables that were optimized out.
868 void DwarfDebug::collectDeadVariables() {
869 const Module *M = MMI->getModule();
871 if (NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu")) {
872 for (MDNode *N : CU_Nodes->operands()) {
873 DICompileUnit TheCU(N);
874 // Construct subprogram DIE and add variables DIEs.
875 DwarfCompileUnit *SPCU =
876 static_cast<DwarfCompileUnit *>(CUMap.lookup(TheCU));
877 assert(SPCU && "Unable to find Compile Unit!");
878 DIArray Subprograms = TheCU.getSubprograms();
879 for (unsigned i = 0, e = Subprograms.getNumElements(); i != e; ++i) {
880 DISubprogram SP(Subprograms.getElement(i));
881 if (ProcessedSPNodes.count(SP) != 0)
883 assert(SP.isSubprogram() &&
884 "CU's subprogram list contains a non-subprogram");
885 assert(SP.isDefinition() &&
886 "CU's subprogram list contains a subprogram declaration");
887 DIArray Variables = SP.getVariables();
888 if (Variables.getNumElements() == 0)
891 DIE *SPDIE = AbstractSPDies.lookup(SP);
893 SPDIE = SPCU->getDIE(SP);
895 for (unsigned vi = 0, ve = Variables.getNumElements(); vi != ve; ++vi) {
896 DIVariable DV(Variables.getElement(vi));
897 assert(DV.isVariable());
898 DbgVariable NewVar(DV, this);
899 auto VariableDie = SPCU->constructVariableDIE(NewVar);
900 SPCU->applyVariableAttributes(NewVar, *VariableDie);
901 SPDIE->addChild(std::move(VariableDie));
908 void DwarfDebug::finalizeModuleInfo() {
909 finishSubprogramDefinitions();
911 finishVariableDefinitions();
913 // Collect info for variables that were optimized out.
914 collectDeadVariables();
916 // Handle anything that needs to be done on a per-unit basis after
917 // all other generation.
918 for (const auto &TheU : getUnits()) {
919 // Emit DW_AT_containing_type attribute to connect types with their
920 // vtable holding type.
921 TheU->constructContainingTypeDIEs();
923 // Add CU specific attributes if we need to add any.
924 if (TheU->getUnitDie().getTag() == dwarf::DW_TAG_compile_unit) {
925 // If we're splitting the dwarf out now that we've got the entire
926 // CU then add the dwo id to it.
927 DwarfCompileUnit *SkCU =
928 static_cast<DwarfCompileUnit *>(TheU->getSkeleton());
929 if (useSplitDwarf()) {
930 // Emit a unique identifier for this CU.
931 uint64_t ID = DIEHash(Asm).computeCUSignature(TheU->getUnitDie());
932 TheU->addUInt(TheU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
933 dwarf::DW_FORM_data8, ID);
934 SkCU->addUInt(SkCU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
935 dwarf::DW_FORM_data8, ID);
937 // We don't keep track of which addresses are used in which CU so this
938 // is a bit pessimistic under LTO.
939 if (!AddrPool.isEmpty())
940 addSectionLabel(*Asm, *SkCU, SkCU->getUnitDie(),
941 dwarf::DW_AT_GNU_addr_base, DwarfAddrSectionSym,
942 DwarfAddrSectionSym);
943 if (!TheU->getRangeLists().empty())
944 addSectionLabel(*Asm, *SkCU, SkCU->getUnitDie(),
945 dwarf::DW_AT_GNU_ranges_base,
946 DwarfDebugRangeSectionSym, DwarfDebugRangeSectionSym);
949 // If we have code split among multiple sections or non-contiguous
950 // ranges of code then emit a DW_AT_ranges attribute on the unit that will
951 // remain in the .o file, otherwise add a DW_AT_low_pc.
952 // FIXME: We should use ranges allow reordering of code ala
953 // .subsections_via_symbols in mach-o. This would mean turning on
954 // ranges for all subprogram DIEs for mach-o.
955 DwarfCompileUnit &U =
956 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 attachLowHighPC(U, U.getUnitDie(), Range.getStart(), Range.getEnd());
978 // Compute DIE offsets and sizes.
979 InfoHolder.computeSizeAndOffsets();
981 SkeletonHolder.computeSizeAndOffsets();
984 void DwarfDebug::endSections() {
985 // Filter labels by section.
986 for (const SymbolCU &SCU : ArangeLabels) {
987 if (SCU.Sym->isInSection()) {
988 // Make a note of this symbol and it's section.
989 const MCSection *Section = &SCU.Sym->getSection();
990 if (!Section->getKind().isMetadata())
991 SectionMap[Section].push_back(SCU);
993 // Some symbols (e.g. common/bss on mach-o) can have no section but still
994 // appear in the output. This sucks as we rely on sections to build
995 // arange spans. We can do it without, but it's icky.
996 SectionMap[nullptr].push_back(SCU);
1000 // Build a list of sections used.
1001 std::vector<const MCSection *> Sections;
1002 for (const auto &it : SectionMap) {
1003 const MCSection *Section = it.first;
1004 Sections.push_back(Section);
1007 // Sort the sections into order.
1008 // This is only done to ensure consistent output order across different runs.
1009 std::sort(Sections.begin(), Sections.end(), SectionSort);
1011 // Add terminating symbols for each section.
1012 for (unsigned ID = 0, E = Sections.size(); ID != E; ID++) {
1013 const MCSection *Section = Sections[ID];
1014 MCSymbol *Sym = nullptr;
1017 // We can't call MCSection::getLabelEndName, as it's only safe to do so
1018 // if we know the section name up-front. For user-created sections, the
1019 // resulting label may not be valid to use as a label. (section names can
1020 // use a greater set of characters on some systems)
1021 Sym = Asm->GetTempSymbol("debug_end", ID);
1022 Asm->OutStreamer.SwitchSection(Section);
1023 Asm->OutStreamer.EmitLabel(Sym);
1026 // Insert a final terminator.
1027 SectionMap[Section].push_back(SymbolCU(nullptr, Sym));
1031 // Emit all Dwarf sections that should come after the content.
1032 void DwarfDebug::endModule() {
1033 assert(CurFn == nullptr);
1034 assert(CurMI == nullptr);
1039 // End any existing sections.
1040 // TODO: Does this need to happen?
1043 // Finalize the debug info for the module.
1044 finalizeModuleInfo();
1048 // Emit all the DIEs into a debug info section.
1051 // Corresponding abbreviations into a abbrev section.
1052 emitAbbreviations();
1054 // Emit info into a debug aranges section.
1055 if (GenerateARangeSection)
1058 // Emit info into a debug ranges section.
1061 if (useSplitDwarf()) {
1064 emitDebugAbbrevDWO();
1067 // Emit DWO addresses.
1068 AddrPool.emit(*Asm, Asm->getObjFileLowering().getDwarfAddrSection());
1070 // Emit info into a debug loc section.
1073 // Emit info into the dwarf accelerator table sections.
1074 if (useDwarfAccelTables()) {
1077 emitAccelNamespaces();
1081 // Emit the pubnames and pubtypes sections if requested.
1082 if (HasDwarfPubSections) {
1083 emitDebugPubNames(GenerateGnuPubSections);
1084 emitDebugPubTypes(GenerateGnuPubSections);
1089 AbstractVariables.clear();
1091 // Reset these for the next Module if we have one.
1095 // Find abstract variable, if any, associated with Var.
1096 DbgVariable *DwarfDebug::getExistingAbstractVariable(const DIVariable &DV,
1097 DIVariable &Cleansed) {
1098 LLVMContext &Ctx = DV->getContext();
1099 // More then one inlined variable corresponds to one abstract variable.
1100 // FIXME: This duplication of variables when inlining should probably be
1101 // removed. It's done to allow each DIVariable to describe its location
1102 // because the DebugLoc on the dbg.value/declare isn't accurate. We should
1103 // make it accurate then remove this duplication/cleansing stuff.
1104 Cleansed = cleanseInlinedVariable(DV, Ctx);
1105 auto I = AbstractVariables.find(Cleansed);
1106 if (I != AbstractVariables.end())
1107 return I->second.get();
1111 DbgVariable *DwarfDebug::getExistingAbstractVariable(const DIVariable &DV) {
1112 DIVariable Cleansed;
1113 return getExistingAbstractVariable(DV, Cleansed);
1116 void DwarfDebug::createAbstractVariable(const DIVariable &Var,
1117 LexicalScope *Scope) {
1118 auto AbsDbgVariable = make_unique<DbgVariable>(Var, this);
1119 addScopeVariable(Scope, AbsDbgVariable.get());
1120 AbstractVariables[Var] = std::move(AbsDbgVariable);
1123 void DwarfDebug::ensureAbstractVariableIsCreated(const DIVariable &DV,
1124 const MDNode *ScopeNode) {
1125 DIVariable Cleansed = DV;
1126 if (getExistingAbstractVariable(DV, Cleansed))
1129 createAbstractVariable(Cleansed, LScopes.getOrCreateAbstractScope(ScopeNode));
1133 DwarfDebug::ensureAbstractVariableIsCreatedIfScoped(const DIVariable &DV,
1134 const MDNode *ScopeNode) {
1135 DIVariable Cleansed = DV;
1136 if (getExistingAbstractVariable(DV, Cleansed))
1139 if (LexicalScope *Scope = LScopes.findAbstractScope(ScopeNode))
1140 createAbstractVariable(Cleansed, Scope);
1143 // If Var is a current function argument then add it to CurrentFnArguments list.
1144 bool DwarfDebug::addCurrentFnArgument(DbgVariable *Var, LexicalScope *Scope) {
1145 if (!LScopes.isCurrentFunctionScope(Scope))
1147 DIVariable DV = Var->getVariable();
1148 if (DV.getTag() != dwarf::DW_TAG_arg_variable)
1150 unsigned ArgNo = DV.getArgNumber();
1154 size_t Size = CurrentFnArguments.size();
1156 CurrentFnArguments.resize(CurFn->getFunction()->arg_size());
1157 // llvm::Function argument size is not good indicator of how many
1158 // arguments does the function have at source level.
1160 CurrentFnArguments.resize(ArgNo * 2);
1161 assert(!CurrentFnArguments[ArgNo - 1]);
1162 CurrentFnArguments[ArgNo - 1] = Var;
1166 // Collect variable information from side table maintained by MMI.
1167 void DwarfDebug::collectVariableInfoFromMMITable(
1168 SmallPtrSetImpl<const MDNode *> &Processed) {
1169 for (const auto &VI : MMI->getVariableDbgInfo()) {
1172 Processed.insert(VI.Var);
1173 DIVariable DV(VI.Var);
1174 LexicalScope *Scope = LScopes.findLexicalScope(VI.Loc);
1176 // If variable scope is not found then skip this variable.
1180 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
1181 ConcreteVariables.push_back(make_unique<DbgVariable>(DV, this));
1182 DbgVariable *RegVar = ConcreteVariables.back().get();
1183 RegVar->setFrameIndex(VI.Slot);
1184 addScopeVariable(Scope, RegVar);
1188 // Get .debug_loc entry for the instruction range starting at MI.
1189 static DebugLocEntry::Value getDebugLocValue(const MachineInstr *MI) {
1190 const MDNode *Var = MI->getDebugVariable();
1192 assert(MI->getNumOperands() == 3);
1193 if (MI->getOperand(0).isReg()) {
1194 MachineLocation MLoc;
1195 // If the second operand is an immediate, this is a
1196 // register-indirect address.
1197 if (!MI->getOperand(1).isImm())
1198 MLoc.set(MI->getOperand(0).getReg());
1200 MLoc.set(MI->getOperand(0).getReg(), MI->getOperand(1).getImm());
1201 return DebugLocEntry::Value(Var, MLoc);
1203 if (MI->getOperand(0).isImm())
1204 return DebugLocEntry::Value(Var, MI->getOperand(0).getImm());
1205 if (MI->getOperand(0).isFPImm())
1206 return DebugLocEntry::Value(Var, MI->getOperand(0).getFPImm());
1207 if (MI->getOperand(0).isCImm())
1208 return DebugLocEntry::Value(Var, MI->getOperand(0).getCImm());
1210 llvm_unreachable("Unexpected 3 operand DBG_VALUE instruction!");
1213 /// Determine whether two variable pieces overlap.
1214 static bool piecesOverlap(DIVariable P1, DIVariable P2) {
1215 if (!P1.isVariablePiece() || !P2.isVariablePiece())
1217 unsigned l1 = P1.getPieceOffset();
1218 unsigned l2 = P2.getPieceOffset();
1219 unsigned r1 = l1 + P1.getPieceSize();
1220 unsigned r2 = l2 + P2.getPieceSize();
1221 // True where [l1,r1[ and [r1,r2[ overlap.
1222 return (l1 < r2) && (l2 < r1);
1225 /// Build the location list for all DBG_VALUEs in the function that
1226 /// describe the same variable. If the ranges of several independent
1227 /// pieces of the same variable overlap partially, split them up and
1228 /// combine the ranges. The resulting DebugLocEntries are will have
1229 /// strict monotonically increasing begin addresses and will never
1234 // Ranges History [var, loc, piece ofs size]
1235 // 0 | [x, (reg0, piece 0, 32)]
1236 // 1 | | [x, (reg1, piece 32, 32)] <- IsPieceOfPrevEntry
1238 // 3 | [clobber reg0]
1239 // 4 [x, (mem, piece 0, 64)] <- overlapping with both previous pieces of x.
1243 // [0-1] [x, (reg0, piece 0, 32)]
1244 // [1-3] [x, (reg0, piece 0, 32), (reg1, piece 32, 32)]
1245 // [3-4] [x, (reg1, piece 32, 32)]
1246 // [4- ] [x, (mem, piece 0, 64)]
1248 DwarfDebug::buildLocationList(SmallVectorImpl<DebugLocEntry> &DebugLoc,
1249 const DbgValueHistoryMap::InstrRanges &Ranges) {
1250 SmallVector<DebugLocEntry::Value, 4> OpenRanges;
1252 for (auto I = Ranges.begin(), E = Ranges.end(); I != E; ++I) {
1253 const MachineInstr *Begin = I->first;
1254 const MachineInstr *End = I->second;
1255 assert(Begin->isDebugValue() && "Invalid History entry");
1257 // Check if a variable is inaccessible in this range.
1258 if (Begin->getNumOperands() > 1 &&
1259 Begin->getOperand(0).isReg() && !Begin->getOperand(0).getReg()) {
1264 // If this piece overlaps with any open ranges, truncate them.
1265 DIVariable DIVar = Begin->getDebugVariable();
1266 auto Last = std::remove_if(OpenRanges.begin(), OpenRanges.end(),
1267 [&](DebugLocEntry::Value R) {
1268 return piecesOverlap(DIVar, R.getVariable());
1270 OpenRanges.erase(Last, OpenRanges.end());
1272 const MCSymbol *StartLabel = getLabelBeforeInsn(Begin);
1273 assert(StartLabel && "Forgot label before DBG_VALUE starting a range!");
1275 const MCSymbol *EndLabel;
1277 EndLabel = getLabelAfterInsn(End);
1278 else if (std::next(I) == Ranges.end())
1279 EndLabel = FunctionEndSym;
1281 EndLabel = getLabelBeforeInsn(std::next(I)->first);
1282 assert(EndLabel && "Forgot label after instruction ending a range!");
1284 DEBUG(dbgs() << "DotDebugLoc: " << *Begin << "\n");
1286 auto Value = getDebugLocValue(Begin);
1287 DebugLocEntry Loc(StartLabel, EndLabel, Value);
1288 bool couldMerge = false;
1290 // If this is a piece, it may belong to the current DebugLocEntry.
1291 if (DIVar.isVariablePiece()) {
1292 // Add this value to the list of open ranges.
1293 OpenRanges.push_back(Value);
1295 // Attempt to add the piece to the last entry.
1296 if (!DebugLoc.empty())
1297 if (DebugLoc.back().MergeValues(Loc))
1302 // Need to add a new DebugLocEntry. Add all values from still
1303 // valid non-overlapping pieces.
1304 if (OpenRanges.size())
1305 Loc.addValues(OpenRanges);
1307 DebugLoc.push_back(std::move(Loc));
1310 // Attempt to coalesce the ranges of two otherwise identical
1312 auto CurEntry = DebugLoc.rbegin();
1313 auto PrevEntry = std::next(CurEntry);
1314 if (PrevEntry != DebugLoc.rend() && PrevEntry->MergeRanges(*CurEntry))
1315 DebugLoc.pop_back();
1317 DEBUG(dbgs() << "Values:\n";
1318 for (auto Value : CurEntry->getValues())
1319 Value.getVariable()->dump();
1320 dbgs() << "-----\n");
1325 // Find variables for each lexical scope.
1327 DwarfDebug::collectVariableInfo(SmallPtrSetImpl<const MDNode *> &Processed) {
1328 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1329 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1331 // Grab the variable info that was squirreled away in the MMI side-table.
1332 collectVariableInfoFromMMITable(Processed);
1334 for (const auto &I : DbgValues) {
1335 DIVariable DV(I.first);
1336 if (Processed.count(DV))
1339 // Instruction ranges, specifying where DV is accessible.
1340 const auto &Ranges = I.second;
1344 LexicalScope *Scope = nullptr;
1345 if (MDNode *IA = DV.getInlinedAt()) {
1346 DebugLoc DL = DebugLoc::getFromDILocation(IA);
1347 Scope = LScopes.findInlinedScope(DebugLoc::get(
1348 DL.getLine(), DL.getCol(), DV.getContext(), IA));
1350 Scope = LScopes.findLexicalScope(DV.getContext());
1351 // If variable scope is not found then skip this variable.
1355 Processed.insert(getEntireVariable(DV));
1356 const MachineInstr *MInsn = Ranges.front().first;
1357 assert(MInsn->isDebugValue() && "History must begin with debug value");
1358 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
1359 ConcreteVariables.push_back(make_unique<DbgVariable>(MInsn, this));
1360 DbgVariable *RegVar = ConcreteVariables.back().get();
1361 addScopeVariable(Scope, RegVar);
1363 // Check if the first DBG_VALUE is valid for the rest of the function.
1364 if (Ranges.size() == 1 && Ranges.front().second == nullptr)
1367 // Handle multiple DBG_VALUE instructions describing one variable.
1368 RegVar->setDotDebugLocOffset(DotDebugLocEntries.size());
1370 DotDebugLocEntries.resize(DotDebugLocEntries.size() + 1);
1371 DebugLocList &LocList = DotDebugLocEntries.back();
1374 Asm->GetTempSymbol("debug_loc", DotDebugLocEntries.size() - 1);
1376 // Build the location list for this variable.
1377 buildLocationList(LocList.List, Ranges);
1380 // Collect info for variables that were optimized out.
1381 DIArray Variables = DISubprogram(FnScope->getScopeNode()).getVariables();
1382 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1383 DIVariable DV(Variables.getElement(i));
1384 assert(DV.isVariable());
1385 if (!Processed.insert(DV))
1387 if (LexicalScope *Scope = LScopes.findLexicalScope(DV.getContext())) {
1388 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
1389 ConcreteVariables.push_back(make_unique<DbgVariable>(DV, this));
1390 addScopeVariable(Scope, ConcreteVariables.back().get());
1395 // Return Label preceding the instruction.
1396 MCSymbol *DwarfDebug::getLabelBeforeInsn(const MachineInstr *MI) {
1397 MCSymbol *Label = LabelsBeforeInsn.lookup(MI);
1398 assert(Label && "Didn't insert label before instruction");
1402 // Return Label immediately following the instruction.
1403 MCSymbol *DwarfDebug::getLabelAfterInsn(const MachineInstr *MI) {
1404 return LabelsAfterInsn.lookup(MI);
1407 // Process beginning of an instruction.
1408 void DwarfDebug::beginInstruction(const MachineInstr *MI) {
1409 assert(CurMI == nullptr);
1411 // Check if source location changes, but ignore DBG_VALUE locations.
1412 if (!MI->isDebugValue()) {
1413 DebugLoc DL = MI->getDebugLoc();
1414 if (DL != PrevInstLoc && (!DL.isUnknown() || UnknownLocations)) {
1417 if (DL == PrologEndLoc) {
1418 Flags |= DWARF2_FLAG_PROLOGUE_END;
1419 PrologEndLoc = DebugLoc();
1421 if (PrologEndLoc.isUnknown())
1422 Flags |= DWARF2_FLAG_IS_STMT;
1424 if (!DL.isUnknown()) {
1425 const MDNode *Scope = DL.getScope(Asm->MF->getFunction()->getContext());
1426 recordSourceLine(DL.getLine(), DL.getCol(), Scope, Flags);
1428 recordSourceLine(0, 0, nullptr, 0);
1432 // Insert labels where requested.
1433 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1434 LabelsBeforeInsn.find(MI);
1437 if (I == LabelsBeforeInsn.end())
1440 // Label already assigned.
1445 PrevLabel = MMI->getContext().CreateTempSymbol();
1446 Asm->OutStreamer.EmitLabel(PrevLabel);
1448 I->second = PrevLabel;
1451 // Process end of an instruction.
1452 void DwarfDebug::endInstruction() {
1453 assert(CurMI != nullptr);
1454 // Don't create a new label after DBG_VALUE instructions.
1455 // They don't generate code.
1456 if (!CurMI->isDebugValue())
1457 PrevLabel = nullptr;
1459 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1460 LabelsAfterInsn.find(CurMI);
1464 if (I == LabelsAfterInsn.end())
1467 // Label already assigned.
1471 // We need a label after this instruction.
1473 PrevLabel = MMI->getContext().CreateTempSymbol();
1474 Asm->OutStreamer.EmitLabel(PrevLabel);
1476 I->second = PrevLabel;
1479 // Each LexicalScope has first instruction and last instruction to mark
1480 // beginning and end of a scope respectively. Create an inverse map that list
1481 // scopes starts (and ends) with an instruction. One instruction may start (or
1482 // end) multiple scopes. Ignore scopes that are not reachable.
1483 void DwarfDebug::identifyScopeMarkers() {
1484 SmallVector<LexicalScope *, 4> WorkList;
1485 WorkList.push_back(LScopes.getCurrentFunctionScope());
1486 while (!WorkList.empty()) {
1487 LexicalScope *S = WorkList.pop_back_val();
1489 const SmallVectorImpl<LexicalScope *> &Children = S->getChildren();
1490 if (!Children.empty())
1491 WorkList.append(Children.begin(), Children.end());
1493 if (S->isAbstractScope())
1496 for (const InsnRange &R : S->getRanges()) {
1497 assert(R.first && "InsnRange does not have first instruction!");
1498 assert(R.second && "InsnRange does not have second instruction!");
1499 requestLabelBeforeInsn(R.first);
1500 requestLabelAfterInsn(R.second);
1505 static DebugLoc findPrologueEndLoc(const MachineFunction *MF) {
1506 // First known non-DBG_VALUE and non-frame setup location marks
1507 // the beginning of the function body.
1508 for (const auto &MBB : *MF)
1509 for (const auto &MI : MBB)
1510 if (!MI.isDebugValue() && !MI.getFlag(MachineInstr::FrameSetup) &&
1511 !MI.getDebugLoc().isUnknown())
1512 return MI.getDebugLoc();
1516 // Gather pre-function debug information. Assumes being called immediately
1517 // after the function entry point has been emitted.
1518 void DwarfDebug::beginFunction(const MachineFunction *MF) {
1521 // If there's no debug info for the function we're not going to do anything.
1522 if (!MMI->hasDebugInfo())
1525 auto DI = FunctionDIs.find(MF->getFunction());
1526 if (DI == FunctionDIs.end())
1529 // Grab the lexical scopes for the function, if we don't have any of those
1530 // then we're not going to be able to do anything.
1531 LScopes.initialize(*MF);
1532 if (LScopes.empty())
1535 assert(DbgValues.empty() && "DbgValues map wasn't cleaned!");
1537 // Make sure that each lexical scope will have a begin/end label.
1538 identifyScopeMarkers();
1540 // Set DwarfDwarfCompileUnitID in MCContext to the Compile Unit this function
1541 // belongs to so that we add to the correct per-cu line table in the
1543 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1544 // FnScope->getScopeNode() and DI->second should represent the same function,
1545 // though they may not be the same MDNode due to inline functions merged in
1546 // LTO where the debug info metadata still differs (either due to distinct
1547 // written differences - two versions of a linkonce_odr function
1548 // written/copied into two separate files, or some sub-optimal metadata that
1549 // isn't structurally identical (see: file path/name info from clang, which
1550 // includes the directory of the cpp file being built, even when the file name
1551 // is absolute (such as an <> lookup header)))
1552 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1553 assert(TheCU && "Unable to find compile unit!");
1554 if (Asm->OutStreamer.hasRawTextSupport())
1555 // Use a single line table if we are generating assembly.
1556 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1558 Asm->OutStreamer.getContext().setDwarfCompileUnitID(TheCU->getUniqueID());
1560 // Emit a label for the function so that we have a beginning address.
1561 FunctionBeginSym = Asm->GetTempSymbol("func_begin", Asm->getFunctionNumber());
1562 // Assumes in correct section after the entry point.
1563 Asm->OutStreamer.EmitLabel(FunctionBeginSym);
1565 // Calculate history for local variables.
1566 calculateDbgValueHistory(MF, Asm->TM.getSubtargetImpl()->getRegisterInfo(),
1569 // Request labels for the full history.
1570 for (const auto &I : DbgValues) {
1571 const auto &Ranges = I.second;
1575 // The first mention of a function argument gets the FunctionBeginSym
1576 // label, so arguments are visible when breaking at function entry.
1577 DIVariable DV(Ranges.front().first->getDebugVariable());
1578 if (DV.isVariable() && DV.getTag() == dwarf::DW_TAG_arg_variable &&
1579 getDISubprogram(DV.getContext()).describes(MF->getFunction())) {
1580 if (!DV.isVariablePiece())
1581 LabelsBeforeInsn[Ranges.front().first] = FunctionBeginSym;
1583 // Mark all non-overlapping initial pieces.
1584 for (auto I = Ranges.begin(); I != Ranges.end(); ++I) {
1585 DIVariable Piece = I->first->getDebugVariable();
1586 if (std::all_of(Ranges.begin(), I,
1587 [&](DbgValueHistoryMap::InstrRange Pred){
1588 return !piecesOverlap(Piece, Pred.first->getDebugVariable());
1590 LabelsBeforeInsn[I->first] = FunctionBeginSym;
1597 for (const auto &Range : Ranges) {
1598 requestLabelBeforeInsn(Range.first);
1600 requestLabelAfterInsn(Range.second);
1604 PrevInstLoc = DebugLoc();
1605 PrevLabel = FunctionBeginSym;
1607 // Record beginning of function.
1608 PrologEndLoc = findPrologueEndLoc(MF);
1609 if (!PrologEndLoc.isUnknown()) {
1610 DebugLoc FnStartDL =
1611 PrologEndLoc.getFnDebugLoc(MF->getFunction()->getContext());
1613 FnStartDL.getLine(), FnStartDL.getCol(),
1614 FnStartDL.getScope(MF->getFunction()->getContext()),
1615 // We'd like to list the prologue as "not statements" but GDB behaves
1616 // poorly if we do that. Revisit this with caution/GDB (7.5+) testing.
1617 DWARF2_FLAG_IS_STMT);
1621 void DwarfDebug::addScopeVariable(LexicalScope *LS, DbgVariable *Var) {
1622 if (addCurrentFnArgument(Var, LS))
1624 SmallVectorImpl<DbgVariable *> &Vars = ScopeVariables[LS];
1625 DIVariable DV = Var->getVariable();
1626 // Variables with positive arg numbers are parameters.
1627 if (unsigned ArgNum = DV.getArgNumber()) {
1628 // Keep all parameters in order at the start of the variable list to ensure
1629 // function types are correct (no out-of-order parameters)
1631 // This could be improved by only doing it for optimized builds (unoptimized
1632 // builds have the right order to begin with), searching from the back (this
1633 // would catch the unoptimized case quickly), or doing a binary search
1634 // rather than linear search.
1635 SmallVectorImpl<DbgVariable *>::iterator I = Vars.begin();
1636 while (I != Vars.end()) {
1637 unsigned CurNum = (*I)->getVariable().getArgNumber();
1638 // A local (non-parameter) variable has been found, insert immediately
1642 // A later indexed parameter has been found, insert immediately before it.
1643 if (CurNum > ArgNum)
1647 Vars.insert(I, Var);
1651 Vars.push_back(Var);
1654 // Gather and emit post-function debug information.
1655 void DwarfDebug::endFunction(const MachineFunction *MF) {
1656 // Every beginFunction(MF) call should be followed by an endFunction(MF) call,
1657 // though the beginFunction may not be called at all.
1658 // We should handle both cases.
1662 assert(CurFn == MF);
1663 assert(CurFn != nullptr);
1665 if (!MMI->hasDebugInfo() || LScopes.empty() ||
1666 !FunctionDIs.count(MF->getFunction())) {
1667 // If we don't have a lexical scope for this function then there will
1668 // be a hole in the range information. Keep note of this by setting the
1669 // previously used section to nullptr.
1675 // Define end label for subprogram.
1676 FunctionEndSym = Asm->GetTempSymbol("func_end", Asm->getFunctionNumber());
1677 // Assumes in correct section after the entry point.
1678 Asm->OutStreamer.EmitLabel(FunctionEndSym);
1680 // Set DwarfDwarfCompileUnitID in MCContext to default value.
1681 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1683 SmallPtrSet<const MDNode *, 16> ProcessedVars;
1684 collectVariableInfo(ProcessedVars);
1686 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1687 DwarfCompileUnit &TheCU = *SPMap.lookup(FnScope->getScopeNode());
1689 // Construct abstract scopes.
1690 for (LexicalScope *AScope : LScopes.getAbstractScopesList()) {
1691 DISubprogram SP(AScope->getScopeNode());
1692 assert(SP.isSubprogram());
1693 // Collect info for variables that were optimized out.
1694 DIArray Variables = SP.getVariables();
1695 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1696 DIVariable DV(Variables.getElement(i));
1697 assert(DV && DV.isVariable());
1698 if (!ProcessedVars.insert(DV))
1700 ensureAbstractVariableIsCreated(DV, DV.getContext());
1702 constructAbstractSubprogramScopeDIE(TheCU, AScope);
1705 DIE &CurFnDIE = constructSubprogramScopeDIE(TheCU, FnScope);
1706 if (!CurFn->getTarget().Options.DisableFramePointerElim(*CurFn))
1707 TheCU.addFlag(CurFnDIE, dwarf::DW_AT_APPLE_omit_frame_ptr);
1709 // Add the range of this function to the list of ranges for the CU.
1710 RangeSpan Span(FunctionBeginSym, FunctionEndSym);
1711 TheCU.addRange(std::move(Span));
1714 // Ownership of DbgVariables is a bit subtle - ScopeVariables owns all the
1715 // DbgVariables except those that are also in AbstractVariables (since they
1716 // can be used cross-function)
1717 ScopeVariables.clear();
1718 CurrentFnArguments.clear();
1720 LabelsBeforeInsn.clear();
1721 LabelsAfterInsn.clear();
1722 PrevLabel = nullptr;
1726 // Register a source line with debug info. Returns the unique label that was
1727 // emitted and which provides correspondence to the source line list.
1728 void DwarfDebug::recordSourceLine(unsigned Line, unsigned Col, const MDNode *S,
1733 unsigned Discriminator = 0;
1734 if (DIScope Scope = DIScope(S)) {
1735 assert(Scope.isScope());
1736 Fn = Scope.getFilename();
1737 Dir = Scope.getDirectory();
1738 if (Scope.isLexicalBlockFile())
1739 Discriminator = DILexicalBlockFile(S).getDiscriminator();
1741 unsigned CUID = Asm->OutStreamer.getContext().getDwarfCompileUnitID();
1742 Src = static_cast<DwarfCompileUnit &>(*InfoHolder.getUnits()[CUID])
1743 .getOrCreateSourceID(Fn, Dir);
1745 Asm->OutStreamer.EmitDwarfLocDirective(Src, Line, Col, Flags, 0,
1749 //===----------------------------------------------------------------------===//
1751 //===----------------------------------------------------------------------===//
1753 // Emit initial Dwarf sections with a label at the start of each one.
1754 void DwarfDebug::emitSectionLabels() {
1755 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
1757 // Dwarf sections base addresses.
1758 DwarfInfoSectionSym =
1759 emitSectionSym(Asm, TLOF.getDwarfInfoSection(), "section_info");
1760 if (useSplitDwarf()) {
1761 DwarfInfoDWOSectionSym =
1762 emitSectionSym(Asm, TLOF.getDwarfInfoDWOSection(), "section_info_dwo");
1763 DwarfTypesDWOSectionSym =
1764 emitSectionSym(Asm, TLOF.getDwarfTypesDWOSection(), "section_types_dwo");
1766 DwarfAbbrevSectionSym =
1767 emitSectionSym(Asm, TLOF.getDwarfAbbrevSection(), "section_abbrev");
1768 if (useSplitDwarf())
1769 DwarfAbbrevDWOSectionSym = emitSectionSym(
1770 Asm, TLOF.getDwarfAbbrevDWOSection(), "section_abbrev_dwo");
1771 if (GenerateARangeSection)
1772 emitSectionSym(Asm, TLOF.getDwarfARangesSection());
1774 DwarfLineSectionSym =
1775 emitSectionSym(Asm, TLOF.getDwarfLineSection(), "section_line");
1776 if (GenerateGnuPubSections) {
1777 DwarfGnuPubNamesSectionSym =
1778 emitSectionSym(Asm, TLOF.getDwarfGnuPubNamesSection());
1779 DwarfGnuPubTypesSectionSym =
1780 emitSectionSym(Asm, TLOF.getDwarfGnuPubTypesSection());
1781 } else if (HasDwarfPubSections) {
1782 emitSectionSym(Asm, TLOF.getDwarfPubNamesSection());
1783 emitSectionSym(Asm, TLOF.getDwarfPubTypesSection());
1786 DwarfStrSectionSym =
1787 emitSectionSym(Asm, TLOF.getDwarfStrSection(), "info_string");
1788 if (useSplitDwarf()) {
1789 DwarfStrDWOSectionSym =
1790 emitSectionSym(Asm, TLOF.getDwarfStrDWOSection(), "skel_string");
1791 DwarfAddrSectionSym =
1792 emitSectionSym(Asm, TLOF.getDwarfAddrSection(), "addr_sec");
1793 DwarfDebugLocSectionSym =
1794 emitSectionSym(Asm, TLOF.getDwarfLocDWOSection(), "skel_loc");
1796 DwarfDebugLocSectionSym =
1797 emitSectionSym(Asm, TLOF.getDwarfLocSection(), "section_debug_loc");
1798 DwarfDebugRangeSectionSym =
1799 emitSectionSym(Asm, TLOF.getDwarfRangesSection(), "debug_range");
1802 // Recursively emits a debug information entry.
1803 void DwarfDebug::emitDIE(DIE &Die) {
1804 // Get the abbreviation for this DIE.
1805 const DIEAbbrev &Abbrev = Die.getAbbrev();
1807 // Emit the code (index) for the abbreviation.
1808 if (Asm->isVerbose())
1809 Asm->OutStreamer.AddComment("Abbrev [" + Twine(Abbrev.getNumber()) +
1810 "] 0x" + Twine::utohexstr(Die.getOffset()) +
1811 ":0x" + Twine::utohexstr(Die.getSize()) + " " +
1812 dwarf::TagString(Abbrev.getTag()));
1813 Asm->EmitULEB128(Abbrev.getNumber());
1815 const SmallVectorImpl<DIEValue *> &Values = Die.getValues();
1816 const SmallVectorImpl<DIEAbbrevData> &AbbrevData = Abbrev.getData();
1818 // Emit the DIE attribute values.
1819 for (unsigned i = 0, N = Values.size(); i < N; ++i) {
1820 dwarf::Attribute Attr = AbbrevData[i].getAttribute();
1821 dwarf::Form Form = AbbrevData[i].getForm();
1822 assert(Form && "Too many attributes for DIE (check abbreviation)");
1824 if (Asm->isVerbose()) {
1825 Asm->OutStreamer.AddComment(dwarf::AttributeString(Attr));
1826 if (Attr == dwarf::DW_AT_accessibility)
1827 Asm->OutStreamer.AddComment(dwarf::AccessibilityString(
1828 cast<DIEInteger>(Values[i])->getValue()));
1831 // Emit an attribute using the defined form.
1832 Values[i]->EmitValue(Asm, Form);
1835 // Emit the DIE children if any.
1836 if (Abbrev.hasChildren()) {
1837 for (auto &Child : Die.getChildren())
1840 Asm->OutStreamer.AddComment("End Of Children Mark");
1845 // Emit the debug info section.
1846 void DwarfDebug::emitDebugInfo() {
1847 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1849 Holder.emitUnits(this, DwarfAbbrevSectionSym);
1852 // Emit the abbreviation section.
1853 void DwarfDebug::emitAbbreviations() {
1854 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1856 Holder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevSection());
1859 // Emit the last address of the section and the end of the line matrix.
1860 void DwarfDebug::emitEndOfLineMatrix(unsigned SectionEnd) {
1861 // Define last address of section.
1862 Asm->OutStreamer.AddComment("Extended Op");
1865 Asm->OutStreamer.AddComment("Op size");
1866 Asm->EmitInt8(Asm->getDataLayout().getPointerSize() + 1);
1867 Asm->OutStreamer.AddComment("DW_LNE_set_address");
1868 Asm->EmitInt8(dwarf::DW_LNE_set_address);
1870 Asm->OutStreamer.AddComment("Section end label");
1872 Asm->OutStreamer.EmitSymbolValue(
1873 Asm->GetTempSymbol("section_end", SectionEnd),
1874 Asm->getDataLayout().getPointerSize());
1876 // Mark end of matrix.
1877 Asm->OutStreamer.AddComment("DW_LNE_end_sequence");
1883 // Emit visible names into a hashed accelerator table section.
1884 void DwarfDebug::emitAccelNames() {
1885 AccelNames.FinalizeTable(Asm, "Names");
1886 Asm->OutStreamer.SwitchSection(
1887 Asm->getObjFileLowering().getDwarfAccelNamesSection());
1888 MCSymbol *SectionBegin = Asm->GetTempSymbol("names_begin");
1889 Asm->OutStreamer.EmitLabel(SectionBegin);
1891 // Emit the full data.
1892 AccelNames.Emit(Asm, SectionBegin, &InfoHolder);
1895 // Emit objective C classes and categories into a hashed accelerator table
1897 void DwarfDebug::emitAccelObjC() {
1898 AccelObjC.FinalizeTable(Asm, "ObjC");
1899 Asm->OutStreamer.SwitchSection(
1900 Asm->getObjFileLowering().getDwarfAccelObjCSection());
1901 MCSymbol *SectionBegin = Asm->GetTempSymbol("objc_begin");
1902 Asm->OutStreamer.EmitLabel(SectionBegin);
1904 // Emit the full data.
1905 AccelObjC.Emit(Asm, SectionBegin, &InfoHolder);
1908 // Emit namespace dies into a hashed accelerator table.
1909 void DwarfDebug::emitAccelNamespaces() {
1910 AccelNamespace.FinalizeTable(Asm, "namespac");
1911 Asm->OutStreamer.SwitchSection(
1912 Asm->getObjFileLowering().getDwarfAccelNamespaceSection());
1913 MCSymbol *SectionBegin = Asm->GetTempSymbol("namespac_begin");
1914 Asm->OutStreamer.EmitLabel(SectionBegin);
1916 // Emit the full data.
1917 AccelNamespace.Emit(Asm, SectionBegin, &InfoHolder);
1920 // Emit type dies into a hashed accelerator table.
1921 void DwarfDebug::emitAccelTypes() {
1923 AccelTypes.FinalizeTable(Asm, "types");
1924 Asm->OutStreamer.SwitchSection(
1925 Asm->getObjFileLowering().getDwarfAccelTypesSection());
1926 MCSymbol *SectionBegin = Asm->GetTempSymbol("types_begin");
1927 Asm->OutStreamer.EmitLabel(SectionBegin);
1929 // Emit the full data.
1930 AccelTypes.Emit(Asm, SectionBegin, &InfoHolder);
1933 // Public name handling.
1934 // The format for the various pubnames:
1936 // dwarf pubnames - offset/name pairs where the offset is the offset into the CU
1937 // for the DIE that is named.
1939 // gnu pubnames - offset/index value/name tuples where the offset is the offset
1940 // into the CU and the index value is computed according to the type of value
1941 // for the DIE that is named.
1943 // For type units the offset is the offset of the skeleton DIE. For split dwarf
1944 // it's the offset within the debug_info/debug_types dwo section, however, the
1945 // reference in the pubname header doesn't change.
1947 /// computeIndexValue - Compute the gdb index value for the DIE and CU.
1948 static dwarf::PubIndexEntryDescriptor computeIndexValue(DwarfUnit *CU,
1950 dwarf::GDBIndexEntryLinkage Linkage = dwarf::GIEL_STATIC;
1952 // We could have a specification DIE that has our most of our knowledge,
1953 // look for that now.
1954 DIEValue *SpecVal = Die->findAttribute(dwarf::DW_AT_specification);
1956 DIE &SpecDIE = cast<DIEEntry>(SpecVal)->getEntry();
1957 if (SpecDIE.findAttribute(dwarf::DW_AT_external))
1958 Linkage = dwarf::GIEL_EXTERNAL;
1959 } else if (Die->findAttribute(dwarf::DW_AT_external))
1960 Linkage = dwarf::GIEL_EXTERNAL;
1962 switch (Die->getTag()) {
1963 case dwarf::DW_TAG_class_type:
1964 case dwarf::DW_TAG_structure_type:
1965 case dwarf::DW_TAG_union_type:
1966 case dwarf::DW_TAG_enumeration_type:
1967 return dwarf::PubIndexEntryDescriptor(
1968 dwarf::GIEK_TYPE, CU->getLanguage() != dwarf::DW_LANG_C_plus_plus
1969 ? dwarf::GIEL_STATIC
1970 : dwarf::GIEL_EXTERNAL);
1971 case dwarf::DW_TAG_typedef:
1972 case dwarf::DW_TAG_base_type:
1973 case dwarf::DW_TAG_subrange_type:
1974 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_TYPE, dwarf::GIEL_STATIC);
1975 case dwarf::DW_TAG_namespace:
1976 return dwarf::GIEK_TYPE;
1977 case dwarf::DW_TAG_subprogram:
1978 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_FUNCTION, Linkage);
1979 case dwarf::DW_TAG_constant:
1980 case dwarf::DW_TAG_variable:
1981 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE, Linkage);
1982 case dwarf::DW_TAG_enumerator:
1983 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE,
1984 dwarf::GIEL_STATIC);
1986 return dwarf::GIEK_NONE;
1990 /// emitDebugPubNames - Emit visible names into a debug pubnames section.
1992 void DwarfDebug::emitDebugPubNames(bool GnuStyle) {
1993 const MCSection *PSec =
1994 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubNamesSection()
1995 : Asm->getObjFileLowering().getDwarfPubNamesSection();
1997 emitDebugPubSection(GnuStyle, PSec, "Names", &DwarfUnit::getGlobalNames);
2000 void DwarfDebug::emitDebugPubSection(
2001 bool GnuStyle, const MCSection *PSec, StringRef Name,
2002 const StringMap<const DIE *> &(DwarfUnit::*Accessor)() const) {
2003 for (const auto &NU : CUMap) {
2004 DwarfCompileUnit *TheU = NU.second;
2006 const auto &Globals = (TheU->*Accessor)();
2008 if (Globals.empty())
2011 if (auto Skeleton = static_cast<DwarfCompileUnit *>(TheU->getSkeleton()))
2013 unsigned ID = TheU->getUniqueID();
2015 // Start the dwarf pubnames section.
2016 Asm->OutStreamer.SwitchSection(PSec);
2019 Asm->OutStreamer.AddComment("Length of Public " + Name + " Info");
2020 MCSymbol *BeginLabel = Asm->GetTempSymbol("pub" + Name + "_begin", ID);
2021 MCSymbol *EndLabel = Asm->GetTempSymbol("pub" + Name + "_end", ID);
2022 Asm->EmitLabelDifference(EndLabel, BeginLabel, 4);
2024 Asm->OutStreamer.EmitLabel(BeginLabel);
2026 Asm->OutStreamer.AddComment("DWARF Version");
2027 Asm->EmitInt16(dwarf::DW_PUBNAMES_VERSION);
2029 Asm->OutStreamer.AddComment("Offset of Compilation Unit Info");
2030 Asm->EmitSectionOffset(TheU->getLabelBegin(), TheU->getSectionSym());
2032 Asm->OutStreamer.AddComment("Compilation Unit Length");
2033 Asm->EmitLabelDifference(TheU->getLabelEnd(), TheU->getLabelBegin(), 4);
2035 // Emit the pubnames for this compilation unit.
2036 for (const auto &GI : Globals) {
2037 const char *Name = GI.getKeyData();
2038 const DIE *Entity = GI.second;
2040 Asm->OutStreamer.AddComment("DIE offset");
2041 Asm->EmitInt32(Entity->getOffset());
2044 dwarf::PubIndexEntryDescriptor Desc = computeIndexValue(TheU, Entity);
2045 Asm->OutStreamer.AddComment(
2046 Twine("Kind: ") + dwarf::GDBIndexEntryKindString(Desc.Kind) + ", " +
2047 dwarf::GDBIndexEntryLinkageString(Desc.Linkage));
2048 Asm->EmitInt8(Desc.toBits());
2051 Asm->OutStreamer.AddComment("External Name");
2052 Asm->OutStreamer.EmitBytes(StringRef(Name, GI.getKeyLength() + 1));
2055 Asm->OutStreamer.AddComment("End Mark");
2057 Asm->OutStreamer.EmitLabel(EndLabel);
2061 void DwarfDebug::emitDebugPubTypes(bool GnuStyle) {
2062 const MCSection *PSec =
2063 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubTypesSection()
2064 : Asm->getObjFileLowering().getDwarfPubTypesSection();
2066 emitDebugPubSection(GnuStyle, PSec, "Types", &DwarfUnit::getGlobalTypes);
2069 // Emit visible names into a debug str section.
2070 void DwarfDebug::emitDebugStr() {
2071 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
2072 Holder.emitStrings(Asm->getObjFileLowering().getDwarfStrSection());
2075 /// Emits an optimal (=sorted) sequence of DW_OP_pieces.
2076 void DwarfDebug::emitLocPieces(ByteStreamer &Streamer,
2077 const DITypeIdentifierMap &Map,
2078 ArrayRef<DebugLocEntry::Value> Values) {
2079 assert(std::all_of(Values.begin(), Values.end(), [](DebugLocEntry::Value P) {
2080 return P.isVariablePiece();
2081 }) && "all values are expected to be pieces");
2082 assert(std::is_sorted(Values.begin(), Values.end()) &&
2083 "pieces are expected to be sorted");
2085 unsigned Offset = 0;
2086 for (auto Piece : Values) {
2087 DIVariable Var = Piece.getVariable();
2088 unsigned PieceOffset = Var.getPieceOffset();
2089 unsigned PieceSize = Var.getPieceSize();
2090 assert(Offset <= PieceOffset && "overlapping or duplicate pieces");
2091 if (Offset < PieceOffset) {
2092 // The DWARF spec seriously mandates pieces with no locations for gaps.
2093 Asm->EmitDwarfOpPiece(Streamer, (PieceOffset-Offset)*8);
2094 Offset += PieceOffset-Offset;
2097 Offset += PieceSize;
2099 const unsigned SizeOfByte = 8;
2100 assert(!Var.isIndirect() && "indirect address for piece");
2102 unsigned VarSize = Var.getSizeInBits(Map);
2103 assert(PieceSize+PieceOffset <= VarSize/SizeOfByte
2104 && "piece is larger than or outside of variable");
2105 assert(PieceSize*SizeOfByte != VarSize
2106 && "piece covers entire variable");
2108 if (Piece.isLocation() && Piece.getLoc().isReg())
2109 Asm->EmitDwarfRegOpPiece(Streamer,
2111 PieceSize*SizeOfByte);
2113 emitDebugLocValue(Streamer, Piece);
2114 Asm->EmitDwarfOpPiece(Streamer, PieceSize*SizeOfByte);
2120 void DwarfDebug::emitDebugLocEntry(ByteStreamer &Streamer,
2121 const DebugLocEntry &Entry) {
2122 const DebugLocEntry::Value Value = Entry.getValues()[0];
2123 if (Value.isVariablePiece())
2124 // Emit all pieces that belong to the same variable and range.
2125 return emitLocPieces(Streamer, TypeIdentifierMap, Entry.getValues());
2127 assert(Entry.getValues().size() == 1 && "only pieces may have >1 value");
2128 emitDebugLocValue(Streamer, Value);
2131 void DwarfDebug::emitDebugLocValue(ByteStreamer &Streamer,
2132 const DebugLocEntry::Value &Value) {
2133 DIVariable DV = Value.getVariable();
2135 if (Value.isInt()) {
2136 DIBasicType BTy(resolve(DV.getType()));
2137 if (BTy.Verify() && (BTy.getEncoding() == dwarf::DW_ATE_signed ||
2138 BTy.getEncoding() == dwarf::DW_ATE_signed_char)) {
2139 Streamer.EmitInt8(dwarf::DW_OP_consts, "DW_OP_consts");
2140 Streamer.EmitSLEB128(Value.getInt());
2142 Streamer.EmitInt8(dwarf::DW_OP_constu, "DW_OP_constu");
2143 Streamer.EmitULEB128(Value.getInt());
2145 } else if (Value.isLocation()) {
2146 MachineLocation Loc = Value.getLoc();
2147 if (!DV.hasComplexAddress())
2149 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2151 // Complex address entry.
2152 unsigned N = DV.getNumAddrElements();
2154 if (N >= 2 && DV.getAddrElement(0) == DIBuilder::OpPlus) {
2155 if (Loc.getOffset()) {
2157 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2158 Streamer.EmitInt8(dwarf::DW_OP_deref, "DW_OP_deref");
2159 Streamer.EmitInt8(dwarf::DW_OP_plus_uconst, "DW_OP_plus_uconst");
2160 Streamer.EmitSLEB128(DV.getAddrElement(1));
2162 // If first address element is OpPlus then emit
2163 // DW_OP_breg + Offset instead of DW_OP_reg + Offset.
2164 MachineLocation TLoc(Loc.getReg(), DV.getAddrElement(1));
2165 Asm->EmitDwarfRegOp(Streamer, TLoc, DV.isIndirect());
2169 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2172 // Emit remaining complex address elements.
2173 for (; i < N; ++i) {
2174 uint64_t Element = DV.getAddrElement(i);
2175 if (Element == DIBuilder::OpPlus) {
2176 Streamer.EmitInt8(dwarf::DW_OP_plus_uconst, "DW_OP_plus_uconst");
2177 Streamer.EmitULEB128(DV.getAddrElement(++i));
2178 } else if (Element == DIBuilder::OpDeref) {
2180 Streamer.EmitInt8(dwarf::DW_OP_deref, "DW_OP_deref");
2181 } else if (Element == DIBuilder::OpPiece) {
2183 // handled in emitDebugLocEntry.
2185 llvm_unreachable("unknown Opcode found in complex address");
2189 // else ... ignore constant fp. There is not any good way to
2190 // to represent them here in dwarf.
2194 void DwarfDebug::emitDebugLocEntryLocation(const DebugLocEntry &Entry) {
2195 Asm->OutStreamer.AddComment("Loc expr size");
2196 MCSymbol *begin = Asm->OutStreamer.getContext().CreateTempSymbol();
2197 MCSymbol *end = Asm->OutStreamer.getContext().CreateTempSymbol();
2198 Asm->EmitLabelDifference(end, begin, 2);
2199 Asm->OutStreamer.EmitLabel(begin);
2201 APByteStreamer Streamer(*Asm);
2202 emitDebugLocEntry(Streamer, Entry);
2204 Asm->OutStreamer.EmitLabel(end);
2207 // Emit locations into the debug loc section.
2208 void DwarfDebug::emitDebugLoc() {
2209 // Start the dwarf loc section.
2210 Asm->OutStreamer.SwitchSection(
2211 Asm->getObjFileLowering().getDwarfLocSection());
2212 unsigned char Size = Asm->getDataLayout().getPointerSize();
2213 for (const auto &DebugLoc : DotDebugLocEntries) {
2214 Asm->OutStreamer.EmitLabel(DebugLoc.Label);
2215 const DwarfCompileUnit *CU = DebugLoc.CU;
2216 assert(!CU->getRanges().empty());
2217 for (const auto &Entry : DebugLoc.List) {
2218 // Set up the range. This range is relative to the entry point of the
2219 // compile unit. This is a hard coded 0 for low_pc when we're emitting
2220 // ranges, or the DW_AT_low_pc on the compile unit otherwise.
2221 if (CU->getRanges().size() == 1) {
2222 // Grab the begin symbol from the first range as our base.
2223 const MCSymbol *Base = CU->getRanges()[0].getStart();
2224 Asm->EmitLabelDifference(Entry.getBeginSym(), Base, Size);
2225 Asm->EmitLabelDifference(Entry.getEndSym(), Base, Size);
2227 Asm->OutStreamer.EmitSymbolValue(Entry.getBeginSym(), Size);
2228 Asm->OutStreamer.EmitSymbolValue(Entry.getEndSym(), Size);
2231 emitDebugLocEntryLocation(Entry);
2233 Asm->OutStreamer.EmitIntValue(0, Size);
2234 Asm->OutStreamer.EmitIntValue(0, Size);
2238 void DwarfDebug::emitDebugLocDWO() {
2239 Asm->OutStreamer.SwitchSection(
2240 Asm->getObjFileLowering().getDwarfLocDWOSection());
2241 for (const auto &DebugLoc : DotDebugLocEntries) {
2242 Asm->OutStreamer.EmitLabel(DebugLoc.Label);
2243 for (const auto &Entry : DebugLoc.List) {
2244 // Just always use start_length for now - at least that's one address
2245 // rather than two. We could get fancier and try to, say, reuse an
2246 // address we know we've emitted elsewhere (the start of the function?
2247 // The start of the CU or CU subrange that encloses this range?)
2248 Asm->EmitInt8(dwarf::DW_LLE_start_length_entry);
2249 unsigned idx = AddrPool.getIndex(Entry.getBeginSym());
2250 Asm->EmitULEB128(idx);
2251 Asm->EmitLabelDifference(Entry.getEndSym(), Entry.getBeginSym(), 4);
2253 emitDebugLocEntryLocation(Entry);
2255 Asm->EmitInt8(dwarf::DW_LLE_end_of_list_entry);
2260 const MCSymbol *Start, *End;
2263 // Emit a debug aranges section, containing a CU lookup for any
2264 // address we can tie back to a CU.
2265 void DwarfDebug::emitDebugARanges() {
2266 // Start the dwarf aranges section.
2267 Asm->OutStreamer.SwitchSection(
2268 Asm->getObjFileLowering().getDwarfARangesSection());
2270 typedef DenseMap<DwarfCompileUnit *, std::vector<ArangeSpan>> SpansType;
2274 // Build a list of sections used.
2275 std::vector<const MCSection *> Sections;
2276 for (const auto &it : SectionMap) {
2277 const MCSection *Section = it.first;
2278 Sections.push_back(Section);
2281 // Sort the sections into order.
2282 // This is only done to ensure consistent output order across different runs.
2283 std::sort(Sections.begin(), Sections.end(), SectionSort);
2285 // Build a set of address spans, sorted by CU.
2286 for (const MCSection *Section : Sections) {
2287 SmallVector<SymbolCU, 8> &List = SectionMap[Section];
2288 if (List.size() < 2)
2291 // Sort the symbols by offset within the section.
2292 std::sort(List.begin(), List.end(),
2293 [&](const SymbolCU &A, const SymbolCU &B) {
2294 unsigned IA = A.Sym ? Asm->OutStreamer.GetSymbolOrder(A.Sym) : 0;
2295 unsigned IB = B.Sym ? Asm->OutStreamer.GetSymbolOrder(B.Sym) : 0;
2297 // Symbols with no order assigned should be placed at the end.
2298 // (e.g. section end labels)
2306 // If we have no section (e.g. common), just write out
2307 // individual spans for each symbol.
2309 for (const SymbolCU &Cur : List) {
2311 Span.Start = Cur.Sym;
2314 Spans[Cur.CU].push_back(Span);
2317 // Build spans between each label.
2318 const MCSymbol *StartSym = List[0].Sym;
2319 for (size_t n = 1, e = List.size(); n < e; n++) {
2320 const SymbolCU &Prev = List[n - 1];
2321 const SymbolCU &Cur = List[n];
2323 // Try and build the longest span we can within the same CU.
2324 if (Cur.CU != Prev.CU) {
2326 Span.Start = StartSym;
2328 Spans[Prev.CU].push_back(Span);
2335 unsigned PtrSize = Asm->getDataLayout().getPointerSize();
2337 // Build a list of CUs used.
2338 std::vector<DwarfCompileUnit *> CUs;
2339 for (const auto &it : Spans) {
2340 DwarfCompileUnit *CU = it.first;
2344 // Sort the CU list (again, to ensure consistent output order).
2345 std::sort(CUs.begin(), CUs.end(), [](const DwarfUnit *A, const DwarfUnit *B) {
2346 return A->getUniqueID() < B->getUniqueID();
2349 // Emit an arange table for each CU we used.
2350 for (DwarfCompileUnit *CU : CUs) {
2351 std::vector<ArangeSpan> &List = Spans[CU];
2353 // Emit size of content not including length itself.
2354 unsigned ContentSize =
2355 sizeof(int16_t) + // DWARF ARange version number
2356 sizeof(int32_t) + // Offset of CU in the .debug_info section
2357 sizeof(int8_t) + // Pointer Size (in bytes)
2358 sizeof(int8_t); // Segment Size (in bytes)
2360 unsigned TupleSize = PtrSize * 2;
2362 // 7.20 in the Dwarf specs requires the table to be aligned to a tuple.
2364 OffsetToAlignment(sizeof(int32_t) + ContentSize, TupleSize);
2366 ContentSize += Padding;
2367 ContentSize += (List.size() + 1) * TupleSize;
2369 // For each compile unit, write the list of spans it covers.
2370 Asm->OutStreamer.AddComment("Length of ARange Set");
2371 Asm->EmitInt32(ContentSize);
2372 Asm->OutStreamer.AddComment("DWARF Arange version number");
2373 Asm->EmitInt16(dwarf::DW_ARANGES_VERSION);
2374 Asm->OutStreamer.AddComment("Offset Into Debug Info Section");
2375 Asm->EmitSectionOffset(CU->getLocalLabelBegin(), CU->getLocalSectionSym());
2376 Asm->OutStreamer.AddComment("Address Size (in bytes)");
2377 Asm->EmitInt8(PtrSize);
2378 Asm->OutStreamer.AddComment("Segment Size (in bytes)");
2381 Asm->OutStreamer.EmitFill(Padding, 0xff);
2383 for (const ArangeSpan &Span : List) {
2384 Asm->EmitLabelReference(Span.Start, PtrSize);
2386 // Calculate the size as being from the span start to it's end.
2388 Asm->EmitLabelDifference(Span.End, Span.Start, PtrSize);
2390 // For symbols without an end marker (e.g. common), we
2391 // write a single arange entry containing just that one symbol.
2392 uint64_t Size = SymSize[Span.Start];
2396 Asm->OutStreamer.EmitIntValue(Size, PtrSize);
2400 Asm->OutStreamer.AddComment("ARange terminator");
2401 Asm->OutStreamer.EmitIntValue(0, PtrSize);
2402 Asm->OutStreamer.EmitIntValue(0, PtrSize);
2406 // Emit visible names into a debug ranges section.
2407 void DwarfDebug::emitDebugRanges() {
2408 // Start the dwarf ranges section.
2409 Asm->OutStreamer.SwitchSection(
2410 Asm->getObjFileLowering().getDwarfRangesSection());
2412 // Size for our labels.
2413 unsigned char Size = Asm->getDataLayout().getPointerSize();
2415 // Grab the specific ranges for the compile units in the module.
2416 for (const auto &I : CUMap) {
2417 DwarfCompileUnit *TheCU = I.second;
2419 // Iterate over the misc ranges for the compile units in the module.
2420 for (const RangeSpanList &List : TheCU->getRangeLists()) {
2421 // Emit our symbol so we can find the beginning of the range.
2422 Asm->OutStreamer.EmitLabel(List.getSym());
2424 for (const RangeSpan &Range : List.getRanges()) {
2425 const MCSymbol *Begin = Range.getStart();
2426 const MCSymbol *End = Range.getEnd();
2427 assert(Begin && "Range without a begin symbol?");
2428 assert(End && "Range without an end symbol?");
2429 if (TheCU->getRanges().size() == 1) {
2430 // Grab the begin symbol from the first range as our base.
2431 const MCSymbol *Base = TheCU->getRanges()[0].getStart();
2432 Asm->EmitLabelDifference(Begin, Base, Size);
2433 Asm->EmitLabelDifference(End, Base, Size);
2435 Asm->OutStreamer.EmitSymbolValue(Begin, Size);
2436 Asm->OutStreamer.EmitSymbolValue(End, Size);
2440 // And terminate the list with two 0 values.
2441 Asm->OutStreamer.EmitIntValue(0, Size);
2442 Asm->OutStreamer.EmitIntValue(0, Size);
2445 // Now emit a range for the CU itself.
2446 if (TheCU->getRanges().size() > 1) {
2447 Asm->OutStreamer.EmitLabel(
2448 Asm->GetTempSymbol("cu_ranges", TheCU->getUniqueID()));
2449 for (const RangeSpan &Range : TheCU->getRanges()) {
2450 const MCSymbol *Begin = Range.getStart();
2451 const MCSymbol *End = Range.getEnd();
2452 assert(Begin && "Range without a begin symbol?");
2453 assert(End && "Range without an end symbol?");
2454 Asm->OutStreamer.EmitSymbolValue(Begin, Size);
2455 Asm->OutStreamer.EmitSymbolValue(End, Size);
2457 // And terminate the list with two 0 values.
2458 Asm->OutStreamer.EmitIntValue(0, Size);
2459 Asm->OutStreamer.EmitIntValue(0, Size);
2464 // DWARF5 Experimental Separate Dwarf emitters.
2466 void DwarfDebug::initSkeletonUnit(const DwarfUnit &U, DIE &Die,
2467 std::unique_ptr<DwarfUnit> NewU) {
2468 NewU->addLocalString(Die, dwarf::DW_AT_GNU_dwo_name,
2469 U.getCUNode().getSplitDebugFilename());
2471 if (!CompilationDir.empty())
2472 NewU->addLocalString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
2474 addGnuPubAttributes(*NewU, Die);
2476 SkeletonHolder.addUnit(std::move(NewU));
2479 // This DIE has the following attributes: DW_AT_comp_dir, DW_AT_stmt_list,
2480 // DW_AT_low_pc, DW_AT_high_pc, DW_AT_ranges, DW_AT_dwo_name, DW_AT_dwo_id,
2481 // DW_AT_addr_base, DW_AT_ranges_base.
2482 DwarfCompileUnit &DwarfDebug::constructSkeletonCU(const DwarfCompileUnit &CU) {
2484 auto OwnedUnit = make_unique<DwarfCompileUnit>(
2485 CU.getUniqueID(), CU.getCUNode(), Asm, this, &SkeletonHolder);
2486 DwarfCompileUnit &NewCU = *OwnedUnit;
2487 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoSection(),
2488 DwarfInfoSectionSym);
2490 NewCU.initStmtList(DwarfLineSectionSym);
2492 initSkeletonUnit(CU, NewCU.getUnitDie(), std::move(OwnedUnit));
2497 // Emit the .debug_info.dwo section for separated dwarf. This contains the
2498 // compile units that would normally be in debug_info.
2499 void DwarfDebug::emitDebugInfoDWO() {
2500 assert(useSplitDwarf() && "No split dwarf debug info?");
2501 // Don't pass an abbrev symbol, using a constant zero instead so as not to
2502 // emit relocations into the dwo file.
2503 InfoHolder.emitUnits(this, /* AbbrevSymbol */ nullptr);
2506 // Emit the .debug_abbrev.dwo section for separated dwarf. This contains the
2507 // abbreviations for the .debug_info.dwo section.
2508 void DwarfDebug::emitDebugAbbrevDWO() {
2509 assert(useSplitDwarf() && "No split dwarf?");
2510 InfoHolder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevDWOSection());
2513 void DwarfDebug::emitDebugLineDWO() {
2514 assert(useSplitDwarf() && "No split dwarf?");
2515 Asm->OutStreamer.SwitchSection(
2516 Asm->getObjFileLowering().getDwarfLineDWOSection());
2517 SplitTypeUnitFileTable.Emit(Asm->OutStreamer);
2520 // Emit the .debug_str.dwo section for separated dwarf. This contains the
2521 // string section and is identical in format to traditional .debug_str
2523 void DwarfDebug::emitDebugStrDWO() {
2524 assert(useSplitDwarf() && "No split dwarf?");
2525 const MCSection *OffSec =
2526 Asm->getObjFileLowering().getDwarfStrOffDWOSection();
2527 const MCSymbol *StrSym = DwarfStrSectionSym;
2528 InfoHolder.emitStrings(Asm->getObjFileLowering().getDwarfStrDWOSection(),
2532 MCDwarfDwoLineTable *DwarfDebug::getDwoLineTable(const DwarfCompileUnit &CU) {
2533 if (!useSplitDwarf())
2536 SplitTypeUnitFileTable.setCompilationDir(CU.getCUNode().getDirectory());
2537 return &SplitTypeUnitFileTable;
2540 static uint64_t makeTypeSignature(StringRef Identifier) {
2542 Hash.update(Identifier);
2543 // ... take the least significant 8 bytes and return those. Our MD5
2544 // implementation always returns its results in little endian, swap bytes
2546 MD5::MD5Result Result;
2548 return *reinterpret_cast<support::ulittle64_t *>(Result + 8);
2551 void DwarfDebug::addDwarfTypeUnitType(DwarfCompileUnit &CU,
2552 StringRef Identifier, DIE &RefDie,
2553 DICompositeType CTy) {
2554 // Fast path if we're building some type units and one has already used the
2555 // address pool we know we're going to throw away all this work anyway, so
2556 // don't bother building dependent types.
2557 if (!TypeUnitsUnderConstruction.empty() && AddrPool.hasBeenUsed())
2560 const DwarfTypeUnit *&TU = DwarfTypeUnits[CTy];
2562 CU.addDIETypeSignature(RefDie, *TU);
2566 bool TopLevelType = TypeUnitsUnderConstruction.empty();
2567 AddrPool.resetUsedFlag();
2569 auto OwnedUnit = make_unique<DwarfTypeUnit>(
2570 InfoHolder.getUnits().size() + TypeUnitsUnderConstruction.size(), CU, Asm,
2571 this, &InfoHolder, getDwoLineTable(CU));
2572 DwarfTypeUnit &NewTU = *OwnedUnit;
2573 DIE &UnitDie = NewTU.getUnitDie();
2575 TypeUnitsUnderConstruction.push_back(
2576 std::make_pair(std::move(OwnedUnit), CTy));
2578 NewTU.addUInt(UnitDie, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
2581 uint64_t Signature = makeTypeSignature(Identifier);
2582 NewTU.setTypeSignature(Signature);
2584 if (useSplitDwarf())
2585 NewTU.initSection(Asm->getObjFileLowering().getDwarfTypesDWOSection(),
2586 DwarfTypesDWOSectionSym);
2588 CU.applyStmtList(UnitDie);
2590 Asm->getObjFileLowering().getDwarfTypesSection(Signature));
2593 NewTU.setType(NewTU.createTypeDIE(CTy));
2596 auto TypeUnitsToAdd = std::move(TypeUnitsUnderConstruction);
2597 TypeUnitsUnderConstruction.clear();
2599 // Types referencing entries in the address table cannot be placed in type
2601 if (AddrPool.hasBeenUsed()) {
2603 // Remove all the types built while building this type.
2604 // This is pessimistic as some of these types might not be dependent on
2605 // the type that used an address.
2606 for (const auto &TU : TypeUnitsToAdd)
2607 DwarfTypeUnits.erase(TU.second);
2609 // Construct this type in the CU directly.
2610 // This is inefficient because all the dependent types will be rebuilt
2611 // from scratch, including building them in type units, discovering that
2612 // they depend on addresses, throwing them out and rebuilding them.
2613 CU.constructTypeDIE(RefDie, CTy);
2617 // If the type wasn't dependent on fission addresses, finish adding the type
2618 // and all its dependent types.
2619 for (auto &TU : TypeUnitsToAdd)
2620 InfoHolder.addUnit(std::move(TU.first));
2622 CU.addDIETypeSignature(RefDie, NewTU);
2625 void DwarfDebug::attachLowHighPC(DwarfCompileUnit &Unit, DIE &D,
2626 const MCSymbol *Begin, const MCSymbol *End) {
2627 assert(Begin && "Begin label should not be null!");
2628 assert(End && "End label should not be null!");
2629 assert(Begin->isDefined() && "Invalid starting label");
2630 assert(End->isDefined() && "Invalid end label");
2632 Unit.addLabelAddress(D, dwarf::DW_AT_low_pc, Begin);
2633 if (DwarfVersion < 4)
2634 Unit.addLabelAddress(D, dwarf::DW_AT_high_pc, End);
2636 Unit.addLabelDelta(D, dwarf::DW_AT_high_pc, End, Begin);
2639 // Accelerator table mutators - add each name along with its companion
2640 // DIE to the proper table while ensuring that the name that we're going
2641 // to reference is in the string table. We do this since the names we
2642 // add may not only be identical to the names in the DIE.
2643 void DwarfDebug::addAccelName(StringRef Name, const DIE &Die) {
2644 if (!useDwarfAccelTables())
2646 AccelNames.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2650 void DwarfDebug::addAccelObjC(StringRef Name, const DIE &Die) {
2651 if (!useDwarfAccelTables())
2653 AccelObjC.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2657 void DwarfDebug::addAccelNamespace(StringRef Name, const DIE &Die) {
2658 if (!useDwarfAccelTables())
2660 AccelNamespace.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2664 void DwarfDebug::addAccelType(StringRef Name, const DIE &Die, char Flags) {
2665 if (!useDwarfAccelTables())
2667 AccelTypes.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),