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 // Only include DW_AT_frame_base in full debug info
323 if (SPCU.getCUNode().getEmissionKind() != DIBuilder::LineTablesOnly) {
324 const TargetRegisterInfo *RI =
325 Asm->TM.getSubtargetImpl()->getRegisterInfo();
326 MachineLocation Location(RI->getFrameRegister(*Asm->MF));
327 SPCU.addAddress(*SPDie, dwarf::DW_AT_frame_base, Location);
330 // Add name to the name table, we do this here because we're guaranteed
331 // to have concrete versions of our DW_TAG_subprogram nodes.
332 addSubprogramNames(SP, *SPDie);
337 /// Check whether we should create a DIE for the given Scope, return true
338 /// if we don't create a DIE (the corresponding DIE is null).
339 bool DwarfDebug::isLexicalScopeDIENull(LexicalScope *Scope) {
340 if (Scope->isAbstractScope())
343 // We don't create a DIE if there is no Range.
344 const SmallVectorImpl<InsnRange> &Ranges = Scope->getRanges();
348 if (Ranges.size() > 1)
351 // We don't create a DIE if we have a single Range and the end label
353 return !getLabelAfterInsn(Ranges.front().second);
356 static void addSectionLabel(AsmPrinter &Asm, DwarfUnit &U, DIE &D,
357 dwarf::Attribute A, const MCSymbol *L,
358 const MCSymbol *Sec) {
359 if (Asm.MAI->doesDwarfUseRelocationsAcrossSections())
360 U.addSectionLabel(D, A, L);
362 U.addSectionDelta(D, A, L, Sec);
365 void DwarfDebug::addScopeRangeList(DwarfCompileUnit &TheCU, DIE &ScopeDIE,
366 const SmallVectorImpl<InsnRange> &Range) {
367 // Emit offset in .debug_range as a relocatable label. emitDIE will handle
368 // emitting it appropriately.
369 MCSymbol *RangeSym = Asm->GetTempSymbol("debug_ranges", GlobalRangeCount++);
371 // Under fission, ranges are specified by constant offsets relative to the
372 // CU's DW_AT_GNU_ranges_base.
374 TheCU.addSectionDelta(ScopeDIE, dwarf::DW_AT_ranges, RangeSym,
375 DwarfDebugRangeSectionSym);
377 addSectionLabel(*Asm, TheCU, ScopeDIE, dwarf::DW_AT_ranges, RangeSym,
378 DwarfDebugRangeSectionSym);
380 RangeSpanList List(RangeSym);
381 for (const InsnRange &R : Range) {
382 RangeSpan Span(getLabelBeforeInsn(R.first), getLabelAfterInsn(R.second));
383 List.addRange(std::move(Span));
386 // Add the range list to the set of ranges to be emitted.
387 TheCU.addRangeList(std::move(List));
390 void DwarfDebug::attachRangesOrLowHighPC(DwarfCompileUnit &TheCU, DIE &Die,
391 const SmallVectorImpl<InsnRange> &Ranges) {
392 assert(!Ranges.empty());
393 if (Ranges.size() == 1)
394 attachLowHighPC(TheCU, Die, getLabelBeforeInsn(Ranges.front().first),
395 getLabelAfterInsn(Ranges.front().second));
397 addScopeRangeList(TheCU, Die, Ranges);
400 // Construct new DW_TAG_lexical_block for this scope and attach
401 // DW_AT_low_pc/DW_AT_high_pc labels.
403 DwarfDebug::constructLexicalScopeDIE(DwarfCompileUnit &TheCU,
404 LexicalScope *Scope) {
405 if (isLexicalScopeDIENull(Scope))
408 auto ScopeDIE = make_unique<DIE>(dwarf::DW_TAG_lexical_block);
409 if (Scope->isAbstractScope())
412 attachRangesOrLowHighPC(TheCU, *ScopeDIE, Scope->getRanges());
417 // This scope represents inlined body of a function. Construct DIE to
418 // represent this concrete inlined copy of the function.
420 DwarfDebug::constructInlinedScopeDIE(DwarfCompileUnit &TheCU,
421 LexicalScope *Scope) {
422 assert(Scope->getScopeNode());
423 DIScope DS(Scope->getScopeNode());
424 DISubprogram InlinedSP = getDISubprogram(DS);
425 // Find the subprogram's DwarfCompileUnit in the SPMap in case the subprogram
426 // was inlined from another compile unit.
427 DIE *OriginDIE = AbstractSPDies[InlinedSP];
428 assert(OriginDIE && "Unable to find original DIE for an inlined subprogram.");
430 auto ScopeDIE = make_unique<DIE>(dwarf::DW_TAG_inlined_subroutine);
431 TheCU.addDIEEntry(*ScopeDIE, dwarf::DW_AT_abstract_origin, *OriginDIE);
433 attachRangesOrLowHighPC(TheCU, *ScopeDIE, Scope->getRanges());
435 InlinedSubprogramDIEs.insert(OriginDIE);
437 // Add the call site information to the DIE.
438 DILocation DL(Scope->getInlinedAt());
439 TheCU.addUInt(*ScopeDIE, dwarf::DW_AT_call_file, None,
440 TheCU.getOrCreateSourceID(DL.getFilename(), DL.getDirectory()));
441 TheCU.addUInt(*ScopeDIE, dwarf::DW_AT_call_line, None, DL.getLineNumber());
443 // Add name to the name table, we do this here because we're guaranteed
444 // to have concrete versions of our DW_TAG_inlined_subprogram nodes.
445 addSubprogramNames(InlinedSP, *ScopeDIE);
450 static std::unique_ptr<DIE> constructVariableDIE(DwarfCompileUnit &TheCU,
452 const LexicalScope &Scope,
453 DIE *&ObjectPointer) {
454 auto Var = TheCU.constructVariableDIE(DV, Scope.isAbstractScope());
455 if (DV.isObjectPointer())
456 ObjectPointer = Var.get();
460 DIE *DwarfDebug::createScopeChildrenDIE(
461 DwarfCompileUnit &TheCU, LexicalScope *Scope,
462 SmallVectorImpl<std::unique_ptr<DIE>> &Children,
463 unsigned *ChildScopeCount) {
464 DIE *ObjectPointer = nullptr;
466 for (DbgVariable *DV : ScopeVariables.lookup(Scope))
467 Children.push_back(constructVariableDIE(TheCU, *DV, *Scope, ObjectPointer));
469 unsigned ChildCountWithoutScopes = Children.size();
471 for (LexicalScope *LS : Scope->getChildren())
472 constructScopeDIE(TheCU, LS, Children);
475 *ChildScopeCount = Children.size() - ChildCountWithoutScopes;
477 return ObjectPointer;
480 DIE *DwarfDebug::createAndAddScopeChildren(DwarfCompileUnit &TheCU,
481 LexicalScope *Scope, DIE &ScopeDIE) {
482 // We create children when the scope DIE is not null.
483 SmallVector<std::unique_ptr<DIE>, 8> Children;
484 DIE *ObjectPointer = createScopeChildrenDIE(TheCU, Scope, Children);
487 for (auto &I : Children)
488 ScopeDIE.addChild(std::move(I));
490 return ObjectPointer;
493 void DwarfDebug::constructAbstractSubprogramScopeDIE(DwarfCompileUnit &TheCU,
494 LexicalScope *Scope) {
495 assert(Scope && Scope->getScopeNode());
496 assert(Scope->isAbstractScope());
497 assert(!Scope->getInlinedAt());
499 DISubprogram SP(Scope->getScopeNode());
501 ProcessedSPNodes.insert(SP);
503 DIE *&AbsDef = AbstractSPDies[SP];
507 // Find the subprogram's DwarfCompileUnit in the SPMap in case the subprogram
508 // was inlined from another compile unit.
509 DwarfCompileUnit &SPCU = *SPMap[SP];
512 // Some of this is duplicated from DwarfUnit::getOrCreateSubprogramDIE, with
513 // the important distinction that the DIDescriptor is not associated with the
514 // DIE (since the DIDescriptor will be associated with the concrete DIE, if
515 // any). It could be refactored to some common utility function.
516 if (DISubprogram SPDecl = SP.getFunctionDeclaration()) {
517 ContextDIE = &SPCU.getUnitDie();
518 SPCU.getOrCreateSubprogramDIE(SPDecl);
520 ContextDIE = SPCU.getOrCreateContextDIE(resolve(SP.getContext()));
522 // Passing null as the associated DIDescriptor because the abstract definition
523 // shouldn't be found by lookup.
524 AbsDef = &SPCU.createAndAddDIE(dwarf::DW_TAG_subprogram, *ContextDIE,
526 SPCU.applySubprogramAttributesToDefinition(SP, *AbsDef);
528 SPCU.addUInt(*AbsDef, dwarf::DW_AT_inline, None, dwarf::DW_INL_inlined);
529 if (DIE *ObjectPointer = createAndAddScopeChildren(SPCU, Scope, *AbsDef))
530 SPCU.addDIEEntry(*AbsDef, dwarf::DW_AT_object_pointer, *ObjectPointer);
533 DIE &DwarfDebug::constructSubprogramScopeDIE(DwarfCompileUnit &TheCU,
534 LexicalScope *Scope) {
535 assert(Scope && Scope->getScopeNode());
536 assert(!Scope->getInlinedAt());
537 assert(!Scope->isAbstractScope());
538 DISubprogram Sub(Scope->getScopeNode());
540 assert(Sub.isSubprogram());
542 ProcessedSPNodes.insert(Sub);
544 DIE &ScopeDIE = updateSubprogramScopeDIE(TheCU, Sub);
546 // Collect arguments for current function.
547 assert(LScopes.isCurrentFunctionScope(Scope));
548 DIE *ObjectPointer = nullptr;
549 for (DbgVariable *ArgDV : CurrentFnArguments)
552 constructVariableDIE(TheCU, *ArgDV, *Scope, ObjectPointer));
554 // If this is a variadic function, add an unspecified parameter.
555 DITypeArray FnArgs = Sub.getType().getTypeArray();
556 // If we have a single element of null, it is a function that returns void.
557 // If we have more than one elements and the last one is null, it is a
558 // variadic function.
559 if (FnArgs.getNumElements() > 1 &&
560 !FnArgs.getElement(FnArgs.getNumElements() - 1))
561 ScopeDIE.addChild(make_unique<DIE>(dwarf::DW_TAG_unspecified_parameters));
563 // Collect lexical scope children first.
564 // ObjectPointer might be a local (non-argument) local variable if it's a
565 // block's synthetic this pointer.
566 if (DIE *BlockObjPtr = createAndAddScopeChildren(TheCU, Scope, ScopeDIE)) {
567 assert(!ObjectPointer && "multiple object pointers can't be described");
568 ObjectPointer = BlockObjPtr;
572 TheCU.addDIEEntry(ScopeDIE, dwarf::DW_AT_object_pointer, *ObjectPointer);
577 // Construct a DIE for this scope.
578 void DwarfDebug::constructScopeDIE(
579 DwarfCompileUnit &TheCU, LexicalScope *Scope,
580 SmallVectorImpl<std::unique_ptr<DIE>> &FinalChildren) {
581 if (!Scope || !Scope->getScopeNode())
584 DIScope DS(Scope->getScopeNode());
586 assert((Scope->getInlinedAt() || !DS.isSubprogram()) &&
587 "Only handle inlined subprograms here, use "
588 "constructSubprogramScopeDIE for non-inlined "
591 SmallVector<std::unique_ptr<DIE>, 8> Children;
593 // We try to create the scope DIE first, then the children DIEs. This will
594 // avoid creating un-used children then removing them later when we find out
595 // the scope DIE is null.
596 std::unique_ptr<DIE> ScopeDIE;
597 if (Scope->getParent() && DS.isSubprogram()) {
598 ScopeDIE = constructInlinedScopeDIE(TheCU, Scope);
601 // We create children when the scope DIE is not null.
602 createScopeChildrenDIE(TheCU, Scope, Children);
604 // Early exit when we know the scope DIE is going to be null.
605 if (isLexicalScopeDIENull(Scope))
608 unsigned ChildScopeCount;
610 // We create children here when we know the scope DIE is not going to be
611 // null and the children will be added to the scope DIE.
612 createScopeChildrenDIE(TheCU, Scope, Children, &ChildScopeCount);
614 // There is no need to emit empty lexical block DIE.
615 std::pair<ImportedEntityMap::const_iterator,
616 ImportedEntityMap::const_iterator> Range =
617 std::equal_range(ScopesWithImportedEntities.begin(),
618 ScopesWithImportedEntities.end(),
619 std::pair<const MDNode *, const MDNode *>(DS, nullptr),
621 for (ImportedEntityMap::const_iterator i = Range.first; i != Range.second;
624 constructImportedEntityDIE(TheCU, DIImportedEntity(i->second)));
625 // If there are only other scopes as children, put them directly in the
626 // parent instead, as this scope would serve no purpose.
627 if (Children.size() == ChildScopeCount) {
628 FinalChildren.insert(FinalChildren.end(),
629 std::make_move_iterator(Children.begin()),
630 std::make_move_iterator(Children.end()));
633 ScopeDIE = constructLexicalScopeDIE(TheCU, Scope);
634 assert(ScopeDIE && "Scope DIE should not be null.");
638 for (auto &I : Children)
639 ScopeDIE->addChild(std::move(I));
641 FinalChildren.push_back(std::move(ScopeDIE));
644 void DwarfDebug::addGnuPubAttributes(DwarfUnit &U, DIE &D) const {
645 if (!GenerateGnuPubSections)
648 U.addFlag(D, dwarf::DW_AT_GNU_pubnames);
651 // Create new DwarfCompileUnit for the given metadata node with tag
652 // DW_TAG_compile_unit.
653 DwarfCompileUnit &DwarfDebug::constructDwarfCompileUnit(DICompileUnit DIUnit) {
654 StringRef FN = DIUnit.getFilename();
655 CompilationDir = DIUnit.getDirectory();
657 auto OwnedUnit = make_unique<DwarfCompileUnit>(
658 InfoHolder.getUnits().size(), DIUnit, Asm, this, &InfoHolder);
659 DwarfCompileUnit &NewCU = *OwnedUnit;
660 DIE &Die = NewCU.getUnitDie();
661 InfoHolder.addUnit(std::move(OwnedUnit));
663 // LTO with assembly output shares a single line table amongst multiple CUs.
664 // To avoid the compilation directory being ambiguous, let the line table
665 // explicitly describe the directory of all files, never relying on the
666 // compilation directory.
667 if (!Asm->OutStreamer.hasRawTextSupport() || SingleCU)
668 Asm->OutStreamer.getContext().setMCLineTableCompilationDir(
669 NewCU.getUniqueID(), CompilationDir);
671 NewCU.addString(Die, dwarf::DW_AT_producer, DIUnit.getProducer());
672 NewCU.addUInt(Die, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
673 DIUnit.getLanguage());
674 NewCU.addString(Die, dwarf::DW_AT_name, FN);
676 if (!useSplitDwarf()) {
677 NewCU.initStmtList(DwarfLineSectionSym);
679 // If we're using split dwarf the compilation dir is going to be in the
680 // skeleton CU and so we don't need to duplicate it here.
681 if (!CompilationDir.empty())
682 NewCU.addString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
684 addGnuPubAttributes(NewCU, Die);
687 if (DIUnit.isOptimized())
688 NewCU.addFlag(Die, dwarf::DW_AT_APPLE_optimized);
690 StringRef Flags = DIUnit.getFlags();
692 NewCU.addString(Die, dwarf::DW_AT_APPLE_flags, Flags);
694 if (unsigned RVer = DIUnit.getRunTimeVersion())
695 NewCU.addUInt(Die, dwarf::DW_AT_APPLE_major_runtime_vers,
696 dwarf::DW_FORM_data1, RVer);
701 if (useSplitDwarf()) {
702 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoDWOSection(),
703 DwarfInfoDWOSectionSym);
704 NewCU.setSkeleton(constructSkeletonCU(NewCU));
706 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoSection(),
707 DwarfInfoSectionSym);
709 CUMap.insert(std::make_pair(DIUnit, &NewCU));
710 CUDieMap.insert(std::make_pair(&Die, &NewCU));
714 void DwarfDebug::constructAndAddImportedEntityDIE(DwarfCompileUnit &TheCU,
716 DIImportedEntity Module(N);
717 assert(Module.Verify());
718 if (DIE *D = TheCU.getOrCreateContextDIE(Module.getContext()))
719 D->addChild(constructImportedEntityDIE(TheCU, Module));
723 DwarfDebug::constructImportedEntityDIE(DwarfCompileUnit &TheCU,
724 const DIImportedEntity &Module) {
725 assert(Module.Verify() &&
726 "Use one of the MDNode * overloads to handle invalid metadata");
727 std::unique_ptr<DIE> IMDie = make_unique<DIE>((dwarf::Tag)Module.getTag());
728 TheCU.insertDIE(Module, IMDie.get());
730 DIDescriptor Entity = resolve(Module.getEntity());
731 if (Entity.isNameSpace())
732 EntityDie = TheCU.getOrCreateNameSpace(DINameSpace(Entity));
733 else if (Entity.isSubprogram())
734 EntityDie = TheCU.getOrCreateSubprogramDIE(DISubprogram(Entity));
735 else if (Entity.isType())
736 EntityDie = TheCU.getOrCreateTypeDIE(DIType(Entity));
738 EntityDie = TheCU.getDIE(Entity);
740 TheCU.addSourceLine(*IMDie, Module.getLineNumber(),
741 Module.getContext().getFilename(),
742 Module.getContext().getDirectory());
743 TheCU.addDIEEntry(*IMDie, dwarf::DW_AT_import, *EntityDie);
744 StringRef Name = Module.getName();
746 TheCU.addString(*IMDie, dwarf::DW_AT_name, Name);
751 // Emit all Dwarf sections that should come prior to the content. Create
752 // global DIEs and emit initial debug info sections. This is invoked by
753 // the target AsmPrinter.
754 void DwarfDebug::beginModule() {
755 if (DisableDebugInfoPrinting)
758 const Module *M = MMI->getModule();
760 FunctionDIs = makeSubprogramMap(*M);
762 // If module has named metadata anchors then use them, otherwise scan the
763 // module using debug info finder to collect debug info.
764 NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
767 TypeIdentifierMap = generateDITypeIdentifierMap(CU_Nodes);
769 // Emit initial sections so we can reference labels later.
772 SingleCU = CU_Nodes->getNumOperands() == 1;
774 for (MDNode *N : CU_Nodes->operands()) {
775 DICompileUnit CUNode(N);
776 DwarfCompileUnit &CU = constructDwarfCompileUnit(CUNode);
777 DIArray ImportedEntities = CUNode.getImportedEntities();
778 for (unsigned i = 0, e = ImportedEntities.getNumElements(); i != e; ++i)
779 ScopesWithImportedEntities.push_back(std::make_pair(
780 DIImportedEntity(ImportedEntities.getElement(i)).getContext(),
781 ImportedEntities.getElement(i)));
782 std::sort(ScopesWithImportedEntities.begin(),
783 ScopesWithImportedEntities.end(), less_first());
784 DIArray GVs = CUNode.getGlobalVariables();
785 for (unsigned i = 0, e = GVs.getNumElements(); i != e; ++i)
786 CU.getOrCreateGlobalVariableDIE(DIGlobalVariable(GVs.getElement(i)));
787 DIArray SPs = CUNode.getSubprograms();
788 for (unsigned i = 0, e = SPs.getNumElements(); i != e; ++i)
789 SPMap.insert(std::make_pair(SPs.getElement(i), &CU));
790 DIArray EnumTypes = CUNode.getEnumTypes();
791 for (unsigned i = 0, e = EnumTypes.getNumElements(); i != e; ++i) {
792 DIType Ty(EnumTypes.getElement(i));
793 // The enum types array by design contains pointers to
794 // MDNodes rather than DIRefs. Unique them here.
795 DIType UniqueTy(resolve(Ty.getRef()));
796 CU.getOrCreateTypeDIE(UniqueTy);
798 DIArray RetainedTypes = CUNode.getRetainedTypes();
799 for (unsigned i = 0, e = RetainedTypes.getNumElements(); i != e; ++i) {
800 DIType Ty(RetainedTypes.getElement(i));
801 // The retained types array by design contains pointers to
802 // MDNodes rather than DIRefs. Unique them here.
803 DIType UniqueTy(resolve(Ty.getRef()));
804 CU.getOrCreateTypeDIE(UniqueTy);
806 // Emit imported_modules last so that the relevant context is already
808 for (unsigned i = 0, e = ImportedEntities.getNumElements(); i != e; ++i)
809 constructAndAddImportedEntityDIE(CU, ImportedEntities.getElement(i));
812 // Tell MMI that we have debug info.
813 MMI->setDebugInfoAvailability(true);
815 // Prime section data.
816 SectionMap[Asm->getObjFileLowering().getTextSection()];
819 void DwarfDebug::finishVariableDefinitions() {
820 for (const auto &Var : ConcreteVariables) {
821 DIE *VariableDie = Var->getDIE();
823 // FIXME: Consider the time-space tradeoff of just storing the unit pointer
824 // in the ConcreteVariables list, rather than looking it up again here.
825 // DIE::getUnit isn't simple - it walks parent pointers, etc.
826 DwarfCompileUnit *Unit = lookupUnit(VariableDie->getUnit());
828 DbgVariable *AbsVar = getExistingAbstractVariable(Var->getVariable());
829 if (AbsVar && AbsVar->getDIE()) {
830 Unit->addDIEEntry(*VariableDie, dwarf::DW_AT_abstract_origin,
833 Unit->applyVariableAttributes(*Var, *VariableDie);
837 void DwarfDebug::finishSubprogramDefinitions() {
838 const Module *M = MMI->getModule();
840 NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
841 for (MDNode *N : CU_Nodes->operands()) {
842 DICompileUnit TheCU(N);
843 // Construct subprogram DIE and add variables DIEs.
844 DwarfCompileUnit *SPCU =
845 static_cast<DwarfCompileUnit *>(CUMap.lookup(TheCU));
846 DIArray Subprograms = TheCU.getSubprograms();
847 for (unsigned i = 0, e = Subprograms.getNumElements(); i != e; ++i) {
848 DISubprogram SP(Subprograms.getElement(i));
849 // Perhaps the subprogram is in another CU (such as due to comdat
850 // folding, etc), in which case ignore it here.
851 if (SPMap[SP] != SPCU)
853 DIE *D = SPCU->getDIE(SP);
854 if (DIE *AbsSPDIE = AbstractSPDies.lookup(SP)) {
856 // If this subprogram has an abstract definition, reference that
857 SPCU->addDIEEntry(*D, dwarf::DW_AT_abstract_origin, *AbsSPDIE);
860 // Lazily construct the subprogram if we didn't see either concrete or
861 // inlined versions during codegen.
862 D = SPCU->getOrCreateSubprogramDIE(SP);
863 // And attach the attributes
864 SPCU->applySubprogramAttributesToDefinition(SP, *D);
871 // Collect info for variables that were optimized out.
872 void DwarfDebug::collectDeadVariables() {
873 const Module *M = MMI->getModule();
875 if (NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu")) {
876 for (MDNode *N : CU_Nodes->operands()) {
877 DICompileUnit TheCU(N);
878 // Construct subprogram DIE and add variables DIEs.
879 DwarfCompileUnit *SPCU =
880 static_cast<DwarfCompileUnit *>(CUMap.lookup(TheCU));
881 assert(SPCU && "Unable to find Compile Unit!");
882 DIArray Subprograms = TheCU.getSubprograms();
883 for (unsigned i = 0, e = Subprograms.getNumElements(); i != e; ++i) {
884 DISubprogram SP(Subprograms.getElement(i));
885 if (ProcessedSPNodes.count(SP) != 0)
887 assert(SP.isSubprogram() &&
888 "CU's subprogram list contains a non-subprogram");
889 assert(SP.isDefinition() &&
890 "CU's subprogram list contains a subprogram declaration");
891 DIArray Variables = SP.getVariables();
892 if (Variables.getNumElements() == 0)
895 DIE *SPDIE = AbstractSPDies.lookup(SP);
897 SPDIE = SPCU->getDIE(SP);
899 for (unsigned vi = 0, ve = Variables.getNumElements(); vi != ve; ++vi) {
900 DIVariable DV(Variables.getElement(vi));
901 assert(DV.isVariable());
902 DbgVariable NewVar(DV, this);
903 auto VariableDie = SPCU->constructVariableDIE(NewVar);
904 SPCU->applyVariableAttributes(NewVar, *VariableDie);
905 SPDIE->addChild(std::move(VariableDie));
912 void DwarfDebug::finalizeModuleInfo() {
913 finishSubprogramDefinitions();
915 finishVariableDefinitions();
917 // Collect info for variables that were optimized out.
918 collectDeadVariables();
920 // Handle anything that needs to be done on a per-unit basis after
921 // all other generation.
922 for (const auto &TheU : getUnits()) {
923 // Emit DW_AT_containing_type attribute to connect types with their
924 // vtable holding type.
925 TheU->constructContainingTypeDIEs();
927 // Add CU specific attributes if we need to add any.
928 if (TheU->getUnitDie().getTag() == dwarf::DW_TAG_compile_unit) {
929 // If we're splitting the dwarf out now that we've got the entire
930 // CU then add the dwo id to it.
931 DwarfCompileUnit *SkCU =
932 static_cast<DwarfCompileUnit *>(TheU->getSkeleton());
933 if (useSplitDwarf()) {
934 // Emit a unique identifier for this CU.
935 uint64_t ID = DIEHash(Asm).computeCUSignature(TheU->getUnitDie());
936 TheU->addUInt(TheU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
937 dwarf::DW_FORM_data8, ID);
938 SkCU->addUInt(SkCU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
939 dwarf::DW_FORM_data8, ID);
941 // We don't keep track of which addresses are used in which CU so this
942 // is a bit pessimistic under LTO.
943 if (!AddrPool.isEmpty())
944 addSectionLabel(*Asm, *SkCU, SkCU->getUnitDie(),
945 dwarf::DW_AT_GNU_addr_base, DwarfAddrSectionSym,
946 DwarfAddrSectionSym);
947 if (!TheU->getRangeLists().empty())
948 addSectionLabel(*Asm, *SkCU, SkCU->getUnitDie(),
949 dwarf::DW_AT_GNU_ranges_base,
950 DwarfDebugRangeSectionSym, DwarfDebugRangeSectionSym);
953 // If we have code split among multiple sections or non-contiguous
954 // ranges of code then emit a DW_AT_ranges attribute on the unit that will
955 // remain in the .o file, otherwise add a DW_AT_low_pc.
956 // FIXME: We should use ranges allow reordering of code ala
957 // .subsections_via_symbols in mach-o. This would mean turning on
958 // ranges for all subprogram DIEs for mach-o.
959 DwarfCompileUnit &U =
960 SkCU ? *SkCU : static_cast<DwarfCompileUnit &>(*TheU);
961 unsigned NumRanges = TheU->getRanges().size();
964 addSectionLabel(*Asm, U, U.getUnitDie(), dwarf::DW_AT_ranges,
965 Asm->GetTempSymbol("cu_ranges", U.getUniqueID()),
966 DwarfDebugRangeSectionSym);
968 // A DW_AT_low_pc attribute may also be specified in combination with
969 // DW_AT_ranges to specify the default base address for use in
970 // location lists (see Section 2.6.2) and range lists (see Section
972 U.addUInt(U.getUnitDie(), dwarf::DW_AT_low_pc, dwarf::DW_FORM_addr,
975 RangeSpan &Range = TheU->getRanges().back();
976 attachLowHighPC(U, U.getUnitDie(), Range.getStart(), Range.getEnd());
982 // Compute DIE offsets and sizes.
983 InfoHolder.computeSizeAndOffsets();
985 SkeletonHolder.computeSizeAndOffsets();
988 void DwarfDebug::endSections() {
989 // Filter labels by section.
990 for (const SymbolCU &SCU : ArangeLabels) {
991 if (SCU.Sym->isInSection()) {
992 // Make a note of this symbol and it's section.
993 const MCSection *Section = &SCU.Sym->getSection();
994 if (!Section->getKind().isMetadata())
995 SectionMap[Section].push_back(SCU);
997 // Some symbols (e.g. common/bss on mach-o) can have no section but still
998 // appear in the output. This sucks as we rely on sections to build
999 // arange spans. We can do it without, but it's icky.
1000 SectionMap[nullptr].push_back(SCU);
1004 // Build a list of sections used.
1005 std::vector<const MCSection *> Sections;
1006 for (const auto &it : SectionMap) {
1007 const MCSection *Section = it.first;
1008 Sections.push_back(Section);
1011 // Sort the sections into order.
1012 // This is only done to ensure consistent output order across different runs.
1013 std::sort(Sections.begin(), Sections.end(), SectionSort);
1015 // Add terminating symbols for each section.
1016 for (unsigned ID = 0, E = Sections.size(); ID != E; ID++) {
1017 const MCSection *Section = Sections[ID];
1018 MCSymbol *Sym = nullptr;
1021 // We can't call MCSection::getLabelEndName, as it's only safe to do so
1022 // if we know the section name up-front. For user-created sections, the
1023 // resulting label may not be valid to use as a label. (section names can
1024 // use a greater set of characters on some systems)
1025 Sym = Asm->GetTempSymbol("debug_end", ID);
1026 Asm->OutStreamer.SwitchSection(Section);
1027 Asm->OutStreamer.EmitLabel(Sym);
1030 // Insert a final terminator.
1031 SectionMap[Section].push_back(SymbolCU(nullptr, Sym));
1035 // Emit all Dwarf sections that should come after the content.
1036 void DwarfDebug::endModule() {
1037 assert(CurFn == nullptr);
1038 assert(CurMI == nullptr);
1043 // End any existing sections.
1044 // TODO: Does this need to happen?
1047 // Finalize the debug info for the module.
1048 finalizeModuleInfo();
1052 // Emit all the DIEs into a debug info section.
1055 // Corresponding abbreviations into a abbrev section.
1056 emitAbbreviations();
1058 // Emit info into a debug aranges section.
1059 if (GenerateARangeSection)
1062 // Emit info into a debug ranges section.
1065 if (useSplitDwarf()) {
1068 emitDebugAbbrevDWO();
1071 // Emit DWO addresses.
1072 AddrPool.emit(*Asm, Asm->getObjFileLowering().getDwarfAddrSection());
1074 // Emit info into a debug loc section.
1077 // Emit info into the dwarf accelerator table sections.
1078 if (useDwarfAccelTables()) {
1081 emitAccelNamespaces();
1085 // Emit the pubnames and pubtypes sections if requested.
1086 if (HasDwarfPubSections) {
1087 emitDebugPubNames(GenerateGnuPubSections);
1088 emitDebugPubTypes(GenerateGnuPubSections);
1093 AbstractVariables.clear();
1095 // Reset these for the next Module if we have one.
1099 // Find abstract variable, if any, associated with Var.
1100 DbgVariable *DwarfDebug::getExistingAbstractVariable(const DIVariable &DV,
1101 DIVariable &Cleansed) {
1102 LLVMContext &Ctx = DV->getContext();
1103 // More then one inlined variable corresponds to one abstract variable.
1104 // FIXME: This duplication of variables when inlining should probably be
1105 // removed. It's done to allow each DIVariable to describe its location
1106 // because the DebugLoc on the dbg.value/declare isn't accurate. We should
1107 // make it accurate then remove this duplication/cleansing stuff.
1108 Cleansed = cleanseInlinedVariable(DV, Ctx);
1109 auto I = AbstractVariables.find(Cleansed);
1110 if (I != AbstractVariables.end())
1111 return I->second.get();
1115 DbgVariable *DwarfDebug::getExistingAbstractVariable(const DIVariable &DV) {
1116 DIVariable Cleansed;
1117 return getExistingAbstractVariable(DV, Cleansed);
1120 void DwarfDebug::createAbstractVariable(const DIVariable &Var,
1121 LexicalScope *Scope) {
1122 auto AbsDbgVariable = make_unique<DbgVariable>(Var, this);
1123 addScopeVariable(Scope, AbsDbgVariable.get());
1124 AbstractVariables[Var] = std::move(AbsDbgVariable);
1127 void DwarfDebug::ensureAbstractVariableIsCreated(const DIVariable &DV,
1128 const MDNode *ScopeNode) {
1129 DIVariable Cleansed = DV;
1130 if (getExistingAbstractVariable(DV, Cleansed))
1133 createAbstractVariable(Cleansed, LScopes.getOrCreateAbstractScope(ScopeNode));
1137 DwarfDebug::ensureAbstractVariableIsCreatedIfScoped(const DIVariable &DV,
1138 const MDNode *ScopeNode) {
1139 DIVariable Cleansed = DV;
1140 if (getExistingAbstractVariable(DV, Cleansed))
1143 if (LexicalScope *Scope = LScopes.findAbstractScope(ScopeNode))
1144 createAbstractVariable(Cleansed, Scope);
1147 // If Var is a current function argument then add it to CurrentFnArguments list.
1148 bool DwarfDebug::addCurrentFnArgument(DbgVariable *Var, LexicalScope *Scope) {
1149 if (!LScopes.isCurrentFunctionScope(Scope))
1151 DIVariable DV = Var->getVariable();
1152 if (DV.getTag() != dwarf::DW_TAG_arg_variable)
1154 unsigned ArgNo = DV.getArgNumber();
1158 size_t Size = CurrentFnArguments.size();
1160 CurrentFnArguments.resize(CurFn->getFunction()->arg_size());
1161 // llvm::Function argument size is not good indicator of how many
1162 // arguments does the function have at source level.
1164 CurrentFnArguments.resize(ArgNo * 2);
1165 assert(!CurrentFnArguments[ArgNo - 1]);
1166 CurrentFnArguments[ArgNo - 1] = Var;
1170 // Collect variable information from side table maintained by MMI.
1171 void DwarfDebug::collectVariableInfoFromMMITable(
1172 SmallPtrSetImpl<const MDNode *> &Processed) {
1173 for (const auto &VI : MMI->getVariableDbgInfo()) {
1176 Processed.insert(VI.Var);
1177 DIVariable DV(VI.Var);
1178 LexicalScope *Scope = LScopes.findLexicalScope(VI.Loc);
1180 // If variable scope is not found then skip this variable.
1184 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
1185 ConcreteVariables.push_back(make_unique<DbgVariable>(DV, this));
1186 DbgVariable *RegVar = ConcreteVariables.back().get();
1187 RegVar->setFrameIndex(VI.Slot);
1188 addScopeVariable(Scope, RegVar);
1192 // Get .debug_loc entry for the instruction range starting at MI.
1193 static DebugLocEntry::Value getDebugLocValue(const MachineInstr *MI) {
1194 const MDNode *Var = MI->getDebugVariable();
1196 assert(MI->getNumOperands() == 3);
1197 if (MI->getOperand(0).isReg()) {
1198 MachineLocation MLoc;
1199 // If the second operand is an immediate, this is a
1200 // register-indirect address.
1201 if (!MI->getOperand(1).isImm())
1202 MLoc.set(MI->getOperand(0).getReg());
1204 MLoc.set(MI->getOperand(0).getReg(), MI->getOperand(1).getImm());
1205 return DebugLocEntry::Value(Var, MLoc);
1207 if (MI->getOperand(0).isImm())
1208 return DebugLocEntry::Value(Var, MI->getOperand(0).getImm());
1209 if (MI->getOperand(0).isFPImm())
1210 return DebugLocEntry::Value(Var, MI->getOperand(0).getFPImm());
1211 if (MI->getOperand(0).isCImm())
1212 return DebugLocEntry::Value(Var, MI->getOperand(0).getCImm());
1214 llvm_unreachable("Unexpected 3 operand DBG_VALUE instruction!");
1217 /// Determine whether two variable pieces overlap.
1218 static bool piecesOverlap(DIVariable P1, DIVariable P2) {
1219 if (!P1.isVariablePiece() || !P2.isVariablePiece())
1221 unsigned l1 = P1.getPieceOffset();
1222 unsigned l2 = P2.getPieceOffset();
1223 unsigned r1 = l1 + P1.getPieceSize();
1224 unsigned r2 = l2 + P2.getPieceSize();
1225 // True where [l1,r1[ and [r1,r2[ overlap.
1226 return (l1 < r2) && (l2 < r1);
1229 /// Build the location list for all DBG_VALUEs in the function that
1230 /// describe the same variable. If the ranges of several independent
1231 /// pieces of the same variable overlap partially, split them up and
1232 /// combine the ranges. The resulting DebugLocEntries are will have
1233 /// strict monotonically increasing begin addresses and will never
1238 // Ranges History [var, loc, piece ofs size]
1239 // 0 | [x, (reg0, piece 0, 32)]
1240 // 1 | | [x, (reg1, piece 32, 32)] <- IsPieceOfPrevEntry
1242 // 3 | [clobber reg0]
1243 // 4 [x, (mem, piece 0, 64)] <- overlapping with both previous pieces of x.
1247 // [0-1] [x, (reg0, piece 0, 32)]
1248 // [1-3] [x, (reg0, piece 0, 32), (reg1, piece 32, 32)]
1249 // [3-4] [x, (reg1, piece 32, 32)]
1250 // [4- ] [x, (mem, piece 0, 64)]
1252 DwarfDebug::buildLocationList(SmallVectorImpl<DebugLocEntry> &DebugLoc,
1253 const DbgValueHistoryMap::InstrRanges &Ranges) {
1254 SmallVector<DebugLocEntry::Value, 4> OpenRanges;
1256 for (auto I = Ranges.begin(), E = Ranges.end(); I != E; ++I) {
1257 const MachineInstr *Begin = I->first;
1258 const MachineInstr *End = I->second;
1259 assert(Begin->isDebugValue() && "Invalid History entry");
1261 // Check if a variable is inaccessible in this range.
1262 if (Begin->getNumOperands() > 1 &&
1263 Begin->getOperand(0).isReg() && !Begin->getOperand(0).getReg()) {
1268 // If this piece overlaps with any open ranges, truncate them.
1269 DIVariable DIVar = Begin->getDebugVariable();
1270 auto Last = std::remove_if(OpenRanges.begin(), OpenRanges.end(),
1271 [&](DebugLocEntry::Value R) {
1272 return piecesOverlap(DIVar, R.getVariable());
1274 OpenRanges.erase(Last, OpenRanges.end());
1276 const MCSymbol *StartLabel = getLabelBeforeInsn(Begin);
1277 assert(StartLabel && "Forgot label before DBG_VALUE starting a range!");
1279 const MCSymbol *EndLabel;
1281 EndLabel = getLabelAfterInsn(End);
1282 else if (std::next(I) == Ranges.end())
1283 EndLabel = FunctionEndSym;
1285 EndLabel = getLabelBeforeInsn(std::next(I)->first);
1286 assert(EndLabel && "Forgot label after instruction ending a range!");
1288 DEBUG(dbgs() << "DotDebugLoc: " << *Begin << "\n");
1290 auto Value = getDebugLocValue(Begin);
1291 DebugLocEntry Loc(StartLabel, EndLabel, Value);
1292 bool couldMerge = false;
1294 // If this is a piece, it may belong to the current DebugLocEntry.
1295 if (DIVar.isVariablePiece()) {
1296 // Add this value to the list of open ranges.
1297 OpenRanges.push_back(Value);
1299 // Attempt to add the piece to the last entry.
1300 if (!DebugLoc.empty())
1301 if (DebugLoc.back().MergeValues(Loc))
1306 // Need to add a new DebugLocEntry. Add all values from still
1307 // valid non-overlapping pieces.
1308 if (OpenRanges.size())
1309 Loc.addValues(OpenRanges);
1311 DebugLoc.push_back(std::move(Loc));
1314 // Attempt to coalesce the ranges of two otherwise identical
1316 auto CurEntry = DebugLoc.rbegin();
1317 auto PrevEntry = std::next(CurEntry);
1318 if (PrevEntry != DebugLoc.rend() && PrevEntry->MergeRanges(*CurEntry))
1319 DebugLoc.pop_back();
1321 DEBUG(dbgs() << "Values:\n";
1322 for (auto Value : CurEntry->getValues())
1323 Value.getVariable()->dump();
1324 dbgs() << "-----\n");
1329 // Find variables for each lexical scope.
1331 DwarfDebug::collectVariableInfo(SmallPtrSetImpl<const MDNode *> &Processed) {
1332 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1333 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1335 // Grab the variable info that was squirreled away in the MMI side-table.
1336 collectVariableInfoFromMMITable(Processed);
1338 for (const auto &I : DbgValues) {
1339 DIVariable DV(I.first);
1340 if (Processed.count(DV))
1343 // Instruction ranges, specifying where DV is accessible.
1344 const auto &Ranges = I.second;
1348 LexicalScope *Scope = nullptr;
1349 if (MDNode *IA = DV.getInlinedAt()) {
1350 DebugLoc DL = DebugLoc::getFromDILocation(IA);
1351 Scope = LScopes.findInlinedScope(DebugLoc::get(
1352 DL.getLine(), DL.getCol(), DV.getContext(), IA));
1354 Scope = LScopes.findLexicalScope(DV.getContext());
1355 // If variable scope is not found then skip this variable.
1359 Processed.insert(getEntireVariable(DV));
1360 const MachineInstr *MInsn = Ranges.front().first;
1361 assert(MInsn->isDebugValue() && "History must begin with debug value");
1362 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
1363 ConcreteVariables.push_back(make_unique<DbgVariable>(MInsn, this));
1364 DbgVariable *RegVar = ConcreteVariables.back().get();
1365 addScopeVariable(Scope, RegVar);
1367 // Check if the first DBG_VALUE is valid for the rest of the function.
1368 if (Ranges.size() == 1 && Ranges.front().second == nullptr)
1371 // Handle multiple DBG_VALUE instructions describing one variable.
1372 RegVar->setDotDebugLocOffset(DotDebugLocEntries.size());
1374 DotDebugLocEntries.resize(DotDebugLocEntries.size() + 1);
1375 DebugLocList &LocList = DotDebugLocEntries.back();
1378 Asm->GetTempSymbol("debug_loc", DotDebugLocEntries.size() - 1);
1380 // Build the location list for this variable.
1381 buildLocationList(LocList.List, Ranges);
1384 // Collect info for variables that were optimized out.
1385 DIArray Variables = DISubprogram(FnScope->getScopeNode()).getVariables();
1386 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1387 DIVariable DV(Variables.getElement(i));
1388 assert(DV.isVariable());
1389 if (!Processed.insert(DV))
1391 if (LexicalScope *Scope = LScopes.findLexicalScope(DV.getContext())) {
1392 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
1393 ConcreteVariables.push_back(make_unique<DbgVariable>(DV, this));
1394 addScopeVariable(Scope, ConcreteVariables.back().get());
1399 // Return Label preceding the instruction.
1400 MCSymbol *DwarfDebug::getLabelBeforeInsn(const MachineInstr *MI) {
1401 MCSymbol *Label = LabelsBeforeInsn.lookup(MI);
1402 assert(Label && "Didn't insert label before instruction");
1406 // Return Label immediately following the instruction.
1407 MCSymbol *DwarfDebug::getLabelAfterInsn(const MachineInstr *MI) {
1408 return LabelsAfterInsn.lookup(MI);
1411 // Process beginning of an instruction.
1412 void DwarfDebug::beginInstruction(const MachineInstr *MI) {
1413 assert(CurMI == nullptr);
1415 // Check if source location changes, but ignore DBG_VALUE locations.
1416 if (!MI->isDebugValue()) {
1417 DebugLoc DL = MI->getDebugLoc();
1418 if (DL != PrevInstLoc && (!DL.isUnknown() || UnknownLocations)) {
1421 if (DL == PrologEndLoc) {
1422 Flags |= DWARF2_FLAG_PROLOGUE_END;
1423 PrologEndLoc = DebugLoc();
1425 if (PrologEndLoc.isUnknown())
1426 Flags |= DWARF2_FLAG_IS_STMT;
1428 if (!DL.isUnknown()) {
1429 const MDNode *Scope = DL.getScope(Asm->MF->getFunction()->getContext());
1430 recordSourceLine(DL.getLine(), DL.getCol(), Scope, Flags);
1432 recordSourceLine(0, 0, nullptr, 0);
1436 // Insert labels where requested.
1437 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1438 LabelsBeforeInsn.find(MI);
1441 if (I == LabelsBeforeInsn.end())
1444 // Label already assigned.
1449 PrevLabel = MMI->getContext().CreateTempSymbol();
1450 Asm->OutStreamer.EmitLabel(PrevLabel);
1452 I->second = PrevLabel;
1455 // Process end of an instruction.
1456 void DwarfDebug::endInstruction() {
1457 assert(CurMI != nullptr);
1458 // Don't create a new label after DBG_VALUE instructions.
1459 // They don't generate code.
1460 if (!CurMI->isDebugValue())
1461 PrevLabel = nullptr;
1463 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1464 LabelsAfterInsn.find(CurMI);
1468 if (I == LabelsAfterInsn.end())
1471 // Label already assigned.
1475 // We need a label after this instruction.
1477 PrevLabel = MMI->getContext().CreateTempSymbol();
1478 Asm->OutStreamer.EmitLabel(PrevLabel);
1480 I->second = PrevLabel;
1483 // Each LexicalScope has first instruction and last instruction to mark
1484 // beginning and end of a scope respectively. Create an inverse map that list
1485 // scopes starts (and ends) with an instruction. One instruction may start (or
1486 // end) multiple scopes. Ignore scopes that are not reachable.
1487 void DwarfDebug::identifyScopeMarkers() {
1488 SmallVector<LexicalScope *, 4> WorkList;
1489 WorkList.push_back(LScopes.getCurrentFunctionScope());
1490 while (!WorkList.empty()) {
1491 LexicalScope *S = WorkList.pop_back_val();
1493 const SmallVectorImpl<LexicalScope *> &Children = S->getChildren();
1494 if (!Children.empty())
1495 WorkList.append(Children.begin(), Children.end());
1497 if (S->isAbstractScope())
1500 for (const InsnRange &R : S->getRanges()) {
1501 assert(R.first && "InsnRange does not have first instruction!");
1502 assert(R.second && "InsnRange does not have second instruction!");
1503 requestLabelBeforeInsn(R.first);
1504 requestLabelAfterInsn(R.second);
1509 static DebugLoc findPrologueEndLoc(const MachineFunction *MF) {
1510 // First known non-DBG_VALUE and non-frame setup location marks
1511 // the beginning of the function body.
1512 for (const auto &MBB : *MF)
1513 for (const auto &MI : MBB)
1514 if (!MI.isDebugValue() && !MI.getFlag(MachineInstr::FrameSetup) &&
1515 !MI.getDebugLoc().isUnknown())
1516 return MI.getDebugLoc();
1520 // Gather pre-function debug information. Assumes being called immediately
1521 // after the function entry point has been emitted.
1522 void DwarfDebug::beginFunction(const MachineFunction *MF) {
1525 // If there's no debug info for the function we're not going to do anything.
1526 if (!MMI->hasDebugInfo())
1529 auto DI = FunctionDIs.find(MF->getFunction());
1530 if (DI == FunctionDIs.end())
1533 // Grab the lexical scopes for the function, if we don't have any of those
1534 // then we're not going to be able to do anything.
1535 LScopes.initialize(*MF);
1536 if (LScopes.empty())
1539 assert(DbgValues.empty() && "DbgValues map wasn't cleaned!");
1541 // Make sure that each lexical scope will have a begin/end label.
1542 identifyScopeMarkers();
1544 // Set DwarfDwarfCompileUnitID in MCContext to the Compile Unit this function
1545 // belongs to so that we add to the correct per-cu line table in the
1547 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1548 // FnScope->getScopeNode() and DI->second should represent the same function,
1549 // though they may not be the same MDNode due to inline functions merged in
1550 // LTO where the debug info metadata still differs (either due to distinct
1551 // written differences - two versions of a linkonce_odr function
1552 // written/copied into two separate files, or some sub-optimal metadata that
1553 // isn't structurally identical (see: file path/name info from clang, which
1554 // includes the directory of the cpp file being built, even when the file name
1555 // is absolute (such as an <> lookup header)))
1556 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1557 assert(TheCU && "Unable to find compile unit!");
1558 if (Asm->OutStreamer.hasRawTextSupport())
1559 // Use a single line table if we are generating assembly.
1560 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1562 Asm->OutStreamer.getContext().setDwarfCompileUnitID(TheCU->getUniqueID());
1564 // Emit a label for the function so that we have a beginning address.
1565 FunctionBeginSym = Asm->GetTempSymbol("func_begin", Asm->getFunctionNumber());
1566 // Assumes in correct section after the entry point.
1567 Asm->OutStreamer.EmitLabel(FunctionBeginSym);
1569 // Calculate history for local variables.
1570 calculateDbgValueHistory(MF, Asm->TM.getSubtargetImpl()->getRegisterInfo(),
1573 // Request labels for the full history.
1574 for (const auto &I : DbgValues) {
1575 const auto &Ranges = I.second;
1579 // The first mention of a function argument gets the FunctionBeginSym
1580 // label, so arguments are visible when breaking at function entry.
1581 DIVariable DV(Ranges.front().first->getDebugVariable());
1582 if (DV.isVariable() && DV.getTag() == dwarf::DW_TAG_arg_variable &&
1583 getDISubprogram(DV.getContext()).describes(MF->getFunction())) {
1584 if (!DV.isVariablePiece())
1585 LabelsBeforeInsn[Ranges.front().first] = FunctionBeginSym;
1587 // Mark all non-overlapping initial pieces.
1588 for (auto I = Ranges.begin(); I != Ranges.end(); ++I) {
1589 DIVariable Piece = I->first->getDebugVariable();
1590 if (std::all_of(Ranges.begin(), I,
1591 [&](DbgValueHistoryMap::InstrRange Pred){
1592 return !piecesOverlap(Piece, Pred.first->getDebugVariable());
1594 LabelsBeforeInsn[I->first] = FunctionBeginSym;
1601 for (const auto &Range : Ranges) {
1602 requestLabelBeforeInsn(Range.first);
1604 requestLabelAfterInsn(Range.second);
1608 PrevInstLoc = DebugLoc();
1609 PrevLabel = FunctionBeginSym;
1611 // Record beginning of function.
1612 PrologEndLoc = findPrologueEndLoc(MF);
1613 if (!PrologEndLoc.isUnknown()) {
1614 DebugLoc FnStartDL =
1615 PrologEndLoc.getFnDebugLoc(MF->getFunction()->getContext());
1617 FnStartDL.getLine(), FnStartDL.getCol(),
1618 FnStartDL.getScope(MF->getFunction()->getContext()),
1619 // We'd like to list the prologue as "not statements" but GDB behaves
1620 // poorly if we do that. Revisit this with caution/GDB (7.5+) testing.
1621 DWARF2_FLAG_IS_STMT);
1625 void DwarfDebug::addScopeVariable(LexicalScope *LS, DbgVariable *Var) {
1626 if (addCurrentFnArgument(Var, LS))
1628 SmallVectorImpl<DbgVariable *> &Vars = ScopeVariables[LS];
1629 DIVariable DV = Var->getVariable();
1630 // Variables with positive arg numbers are parameters.
1631 if (unsigned ArgNum = DV.getArgNumber()) {
1632 // Keep all parameters in order at the start of the variable list to ensure
1633 // function types are correct (no out-of-order parameters)
1635 // This could be improved by only doing it for optimized builds (unoptimized
1636 // builds have the right order to begin with), searching from the back (this
1637 // would catch the unoptimized case quickly), or doing a binary search
1638 // rather than linear search.
1639 SmallVectorImpl<DbgVariable *>::iterator I = Vars.begin();
1640 while (I != Vars.end()) {
1641 unsigned CurNum = (*I)->getVariable().getArgNumber();
1642 // A local (non-parameter) variable has been found, insert immediately
1646 // A later indexed parameter has been found, insert immediately before it.
1647 if (CurNum > ArgNum)
1651 Vars.insert(I, Var);
1655 Vars.push_back(Var);
1658 // Gather and emit post-function debug information.
1659 void DwarfDebug::endFunction(const MachineFunction *MF) {
1660 // Every beginFunction(MF) call should be followed by an endFunction(MF) call,
1661 // though the beginFunction may not be called at all.
1662 // We should handle both cases.
1666 assert(CurFn == MF);
1667 assert(CurFn != nullptr);
1669 if (!MMI->hasDebugInfo() || LScopes.empty() ||
1670 !FunctionDIs.count(MF->getFunction())) {
1671 // If we don't have a lexical scope for this function then there will
1672 // be a hole in the range information. Keep note of this by setting the
1673 // previously used section to nullptr.
1679 // Define end label for subprogram.
1680 FunctionEndSym = Asm->GetTempSymbol("func_end", Asm->getFunctionNumber());
1681 // Assumes in correct section after the entry point.
1682 Asm->OutStreamer.EmitLabel(FunctionEndSym);
1684 // Set DwarfDwarfCompileUnitID in MCContext to default value.
1685 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1687 SmallPtrSet<const MDNode *, 16> ProcessedVars;
1688 collectVariableInfo(ProcessedVars);
1690 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1691 DwarfCompileUnit &TheCU = *SPMap.lookup(FnScope->getScopeNode());
1693 // Construct abstract scopes.
1694 for (LexicalScope *AScope : LScopes.getAbstractScopesList()) {
1695 DISubprogram SP(AScope->getScopeNode());
1696 assert(SP.isSubprogram());
1697 // Collect info for variables that were optimized out.
1698 DIArray Variables = SP.getVariables();
1699 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1700 DIVariable DV(Variables.getElement(i));
1701 assert(DV && DV.isVariable());
1702 if (!ProcessedVars.insert(DV))
1704 ensureAbstractVariableIsCreated(DV, DV.getContext());
1706 constructAbstractSubprogramScopeDIE(TheCU, AScope);
1709 DIE &CurFnDIE = constructSubprogramScopeDIE(TheCU, FnScope);
1710 if (!CurFn->getTarget().Options.DisableFramePointerElim(*CurFn))
1711 TheCU.addFlag(CurFnDIE, dwarf::DW_AT_APPLE_omit_frame_ptr);
1713 // Add the range of this function to the list of ranges for the CU.
1714 RangeSpan Span(FunctionBeginSym, FunctionEndSym);
1715 TheCU.addRange(std::move(Span));
1718 // Ownership of DbgVariables is a bit subtle - ScopeVariables owns all the
1719 // DbgVariables except those that are also in AbstractVariables (since they
1720 // can be used cross-function)
1721 ScopeVariables.clear();
1722 CurrentFnArguments.clear();
1724 LabelsBeforeInsn.clear();
1725 LabelsAfterInsn.clear();
1726 PrevLabel = nullptr;
1730 // Register a source line with debug info. Returns the unique label that was
1731 // emitted and which provides correspondence to the source line list.
1732 void DwarfDebug::recordSourceLine(unsigned Line, unsigned Col, const MDNode *S,
1737 unsigned Discriminator = 0;
1738 if (DIScope Scope = DIScope(S)) {
1739 assert(Scope.isScope());
1740 Fn = Scope.getFilename();
1741 Dir = Scope.getDirectory();
1742 if (Scope.isLexicalBlockFile())
1743 Discriminator = DILexicalBlockFile(S).getDiscriminator();
1745 unsigned CUID = Asm->OutStreamer.getContext().getDwarfCompileUnitID();
1746 Src = static_cast<DwarfCompileUnit &>(*InfoHolder.getUnits()[CUID])
1747 .getOrCreateSourceID(Fn, Dir);
1749 Asm->OutStreamer.EmitDwarfLocDirective(Src, Line, Col, Flags, 0,
1753 //===----------------------------------------------------------------------===//
1755 //===----------------------------------------------------------------------===//
1757 // Emit initial Dwarf sections with a label at the start of each one.
1758 void DwarfDebug::emitSectionLabels() {
1759 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
1761 // Dwarf sections base addresses.
1762 DwarfInfoSectionSym =
1763 emitSectionSym(Asm, TLOF.getDwarfInfoSection(), "section_info");
1764 if (useSplitDwarf()) {
1765 DwarfInfoDWOSectionSym =
1766 emitSectionSym(Asm, TLOF.getDwarfInfoDWOSection(), "section_info_dwo");
1767 DwarfTypesDWOSectionSym =
1768 emitSectionSym(Asm, TLOF.getDwarfTypesDWOSection(), "section_types_dwo");
1770 DwarfAbbrevSectionSym =
1771 emitSectionSym(Asm, TLOF.getDwarfAbbrevSection(), "section_abbrev");
1772 if (useSplitDwarf())
1773 DwarfAbbrevDWOSectionSym = emitSectionSym(
1774 Asm, TLOF.getDwarfAbbrevDWOSection(), "section_abbrev_dwo");
1775 if (GenerateARangeSection)
1776 emitSectionSym(Asm, TLOF.getDwarfARangesSection());
1778 DwarfLineSectionSym =
1779 emitSectionSym(Asm, TLOF.getDwarfLineSection(), "section_line");
1780 if (GenerateGnuPubSections) {
1781 DwarfGnuPubNamesSectionSym =
1782 emitSectionSym(Asm, TLOF.getDwarfGnuPubNamesSection());
1783 DwarfGnuPubTypesSectionSym =
1784 emitSectionSym(Asm, TLOF.getDwarfGnuPubTypesSection());
1785 } else if (HasDwarfPubSections) {
1786 emitSectionSym(Asm, TLOF.getDwarfPubNamesSection());
1787 emitSectionSym(Asm, TLOF.getDwarfPubTypesSection());
1790 DwarfStrSectionSym =
1791 emitSectionSym(Asm, TLOF.getDwarfStrSection(), "info_string");
1792 if (useSplitDwarf()) {
1793 DwarfStrDWOSectionSym =
1794 emitSectionSym(Asm, TLOF.getDwarfStrDWOSection(), "skel_string");
1795 DwarfAddrSectionSym =
1796 emitSectionSym(Asm, TLOF.getDwarfAddrSection(), "addr_sec");
1797 DwarfDebugLocSectionSym =
1798 emitSectionSym(Asm, TLOF.getDwarfLocDWOSection(), "skel_loc");
1800 DwarfDebugLocSectionSym =
1801 emitSectionSym(Asm, TLOF.getDwarfLocSection(), "section_debug_loc");
1802 DwarfDebugRangeSectionSym =
1803 emitSectionSym(Asm, TLOF.getDwarfRangesSection(), "debug_range");
1806 // Recursively emits a debug information entry.
1807 void DwarfDebug::emitDIE(DIE &Die) {
1808 // Get the abbreviation for this DIE.
1809 const DIEAbbrev &Abbrev = Die.getAbbrev();
1811 // Emit the code (index) for the abbreviation.
1812 if (Asm->isVerbose())
1813 Asm->OutStreamer.AddComment("Abbrev [" + Twine(Abbrev.getNumber()) +
1814 "] 0x" + Twine::utohexstr(Die.getOffset()) +
1815 ":0x" + Twine::utohexstr(Die.getSize()) + " " +
1816 dwarf::TagString(Abbrev.getTag()));
1817 Asm->EmitULEB128(Abbrev.getNumber());
1819 const SmallVectorImpl<DIEValue *> &Values = Die.getValues();
1820 const SmallVectorImpl<DIEAbbrevData> &AbbrevData = Abbrev.getData();
1822 // Emit the DIE attribute values.
1823 for (unsigned i = 0, N = Values.size(); i < N; ++i) {
1824 dwarf::Attribute Attr = AbbrevData[i].getAttribute();
1825 dwarf::Form Form = AbbrevData[i].getForm();
1826 assert(Form && "Too many attributes for DIE (check abbreviation)");
1828 if (Asm->isVerbose()) {
1829 Asm->OutStreamer.AddComment(dwarf::AttributeString(Attr));
1830 if (Attr == dwarf::DW_AT_accessibility)
1831 Asm->OutStreamer.AddComment(dwarf::AccessibilityString(
1832 cast<DIEInteger>(Values[i])->getValue()));
1835 // Emit an attribute using the defined form.
1836 Values[i]->EmitValue(Asm, Form);
1839 // Emit the DIE children if any.
1840 if (Abbrev.hasChildren()) {
1841 for (auto &Child : Die.getChildren())
1844 Asm->OutStreamer.AddComment("End Of Children Mark");
1849 // Emit the debug info section.
1850 void DwarfDebug::emitDebugInfo() {
1851 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1853 Holder.emitUnits(this, DwarfAbbrevSectionSym);
1856 // Emit the abbreviation section.
1857 void DwarfDebug::emitAbbreviations() {
1858 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1860 Holder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevSection());
1863 // Emit the last address of the section and the end of the line matrix.
1864 void DwarfDebug::emitEndOfLineMatrix(unsigned SectionEnd) {
1865 // Define last address of section.
1866 Asm->OutStreamer.AddComment("Extended Op");
1869 Asm->OutStreamer.AddComment("Op size");
1870 Asm->EmitInt8(Asm->getDataLayout().getPointerSize() + 1);
1871 Asm->OutStreamer.AddComment("DW_LNE_set_address");
1872 Asm->EmitInt8(dwarf::DW_LNE_set_address);
1874 Asm->OutStreamer.AddComment("Section end label");
1876 Asm->OutStreamer.EmitSymbolValue(
1877 Asm->GetTempSymbol("section_end", SectionEnd),
1878 Asm->getDataLayout().getPointerSize());
1880 // Mark end of matrix.
1881 Asm->OutStreamer.AddComment("DW_LNE_end_sequence");
1887 void DwarfDebug::emitAccel(DwarfAccelTable &Accel, const MCSection *Section,
1888 StringRef TableName, StringRef SymName) {
1889 Accel.FinalizeTable(Asm, TableName);
1890 Asm->OutStreamer.SwitchSection(Section);
1891 auto *SectionBegin = Asm->GetTempSymbol(SymName);
1892 Asm->OutStreamer.EmitLabel(SectionBegin);
1894 // Emit the full data.
1895 Accel.Emit(Asm, SectionBegin, &InfoHolder, DwarfStrSectionSym);
1898 // Emit visible names into a hashed accelerator table section.
1899 void DwarfDebug::emitAccelNames() {
1900 emitAccel(AccelNames, Asm->getObjFileLowering().getDwarfAccelNamesSection(),
1901 "Names", "names_begin");
1904 // Emit objective C classes and categories into a hashed accelerator table
1906 void DwarfDebug::emitAccelObjC() {
1907 emitAccel(AccelObjC, Asm->getObjFileLowering().getDwarfAccelObjCSection(),
1908 "ObjC", "objc_begin");
1911 // Emit namespace dies into a hashed accelerator table.
1912 void DwarfDebug::emitAccelNamespaces() {
1913 emitAccel(AccelNamespace,
1914 Asm->getObjFileLowering().getDwarfAccelNamespaceSection(),
1915 "namespac", "namespac_begin");
1918 // Emit type dies into a hashed accelerator table.
1919 void DwarfDebug::emitAccelTypes() {
1920 emitAccel(AccelTypes, Asm->getObjFileLowering().getDwarfAccelTypesSection(),
1921 "types", "types_begin");
1924 // Public name handling.
1925 // The format for the various pubnames:
1927 // dwarf pubnames - offset/name pairs where the offset is the offset into the CU
1928 // for the DIE that is named.
1930 // gnu pubnames - offset/index value/name tuples where the offset is the offset
1931 // into the CU and the index value is computed according to the type of value
1932 // for the DIE that is named.
1934 // For type units the offset is the offset of the skeleton DIE. For split dwarf
1935 // it's the offset within the debug_info/debug_types dwo section, however, the
1936 // reference in the pubname header doesn't change.
1938 /// computeIndexValue - Compute the gdb index value for the DIE and CU.
1939 static dwarf::PubIndexEntryDescriptor computeIndexValue(DwarfUnit *CU,
1941 dwarf::GDBIndexEntryLinkage Linkage = dwarf::GIEL_STATIC;
1943 // We could have a specification DIE that has our most of our knowledge,
1944 // look for that now.
1945 DIEValue *SpecVal = Die->findAttribute(dwarf::DW_AT_specification);
1947 DIE &SpecDIE = cast<DIEEntry>(SpecVal)->getEntry();
1948 if (SpecDIE.findAttribute(dwarf::DW_AT_external))
1949 Linkage = dwarf::GIEL_EXTERNAL;
1950 } else if (Die->findAttribute(dwarf::DW_AT_external))
1951 Linkage = dwarf::GIEL_EXTERNAL;
1953 switch (Die->getTag()) {
1954 case dwarf::DW_TAG_class_type:
1955 case dwarf::DW_TAG_structure_type:
1956 case dwarf::DW_TAG_union_type:
1957 case dwarf::DW_TAG_enumeration_type:
1958 return dwarf::PubIndexEntryDescriptor(
1959 dwarf::GIEK_TYPE, CU->getLanguage() != dwarf::DW_LANG_C_plus_plus
1960 ? dwarf::GIEL_STATIC
1961 : dwarf::GIEL_EXTERNAL);
1962 case dwarf::DW_TAG_typedef:
1963 case dwarf::DW_TAG_base_type:
1964 case dwarf::DW_TAG_subrange_type:
1965 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_TYPE, dwarf::GIEL_STATIC);
1966 case dwarf::DW_TAG_namespace:
1967 return dwarf::GIEK_TYPE;
1968 case dwarf::DW_TAG_subprogram:
1969 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_FUNCTION, Linkage);
1970 case dwarf::DW_TAG_constant:
1971 case dwarf::DW_TAG_variable:
1972 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE, Linkage);
1973 case dwarf::DW_TAG_enumerator:
1974 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE,
1975 dwarf::GIEL_STATIC);
1977 return dwarf::GIEK_NONE;
1981 /// emitDebugPubNames - Emit visible names into a debug pubnames section.
1983 void DwarfDebug::emitDebugPubNames(bool GnuStyle) {
1984 const MCSection *PSec =
1985 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubNamesSection()
1986 : Asm->getObjFileLowering().getDwarfPubNamesSection();
1988 emitDebugPubSection(GnuStyle, PSec, "Names", &DwarfUnit::getGlobalNames);
1991 void DwarfDebug::emitDebugPubSection(
1992 bool GnuStyle, const MCSection *PSec, StringRef Name,
1993 const StringMap<const DIE *> &(DwarfUnit::*Accessor)() const) {
1994 for (const auto &NU : CUMap) {
1995 DwarfCompileUnit *TheU = NU.second;
1997 const auto &Globals = (TheU->*Accessor)();
1999 if (Globals.empty())
2002 if (auto Skeleton = static_cast<DwarfCompileUnit *>(TheU->getSkeleton()))
2004 unsigned ID = TheU->getUniqueID();
2006 // Start the dwarf pubnames section.
2007 Asm->OutStreamer.SwitchSection(PSec);
2010 Asm->OutStreamer.AddComment("Length of Public " + Name + " Info");
2011 MCSymbol *BeginLabel = Asm->GetTempSymbol("pub" + Name + "_begin", ID);
2012 MCSymbol *EndLabel = Asm->GetTempSymbol("pub" + Name + "_end", ID);
2013 Asm->EmitLabelDifference(EndLabel, BeginLabel, 4);
2015 Asm->OutStreamer.EmitLabel(BeginLabel);
2017 Asm->OutStreamer.AddComment("DWARF Version");
2018 Asm->EmitInt16(dwarf::DW_PUBNAMES_VERSION);
2020 Asm->OutStreamer.AddComment("Offset of Compilation Unit Info");
2021 Asm->EmitSectionOffset(TheU->getLabelBegin(), TheU->getSectionSym());
2023 Asm->OutStreamer.AddComment("Compilation Unit Length");
2024 Asm->EmitLabelDifference(TheU->getLabelEnd(), TheU->getLabelBegin(), 4);
2026 // Emit the pubnames for this compilation unit.
2027 for (const auto &GI : Globals) {
2028 const char *Name = GI.getKeyData();
2029 const DIE *Entity = GI.second;
2031 Asm->OutStreamer.AddComment("DIE offset");
2032 Asm->EmitInt32(Entity->getOffset());
2035 dwarf::PubIndexEntryDescriptor Desc = computeIndexValue(TheU, Entity);
2036 Asm->OutStreamer.AddComment(
2037 Twine("Kind: ") + dwarf::GDBIndexEntryKindString(Desc.Kind) + ", " +
2038 dwarf::GDBIndexEntryLinkageString(Desc.Linkage));
2039 Asm->EmitInt8(Desc.toBits());
2042 Asm->OutStreamer.AddComment("External Name");
2043 Asm->OutStreamer.EmitBytes(StringRef(Name, GI.getKeyLength() + 1));
2046 Asm->OutStreamer.AddComment("End Mark");
2048 Asm->OutStreamer.EmitLabel(EndLabel);
2052 void DwarfDebug::emitDebugPubTypes(bool GnuStyle) {
2053 const MCSection *PSec =
2054 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubTypesSection()
2055 : Asm->getObjFileLowering().getDwarfPubTypesSection();
2057 emitDebugPubSection(GnuStyle, PSec, "Types", &DwarfUnit::getGlobalTypes);
2060 // Emit visible names into a debug str section.
2061 void DwarfDebug::emitDebugStr() {
2062 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
2063 Holder.emitStrings(Asm->getObjFileLowering().getDwarfStrSection());
2066 /// Emits an optimal (=sorted) sequence of DW_OP_pieces.
2067 void DwarfDebug::emitLocPieces(ByteStreamer &Streamer,
2068 const DITypeIdentifierMap &Map,
2069 ArrayRef<DebugLocEntry::Value> Values) {
2070 assert(std::all_of(Values.begin(), Values.end(), [](DebugLocEntry::Value P) {
2071 return P.isVariablePiece();
2072 }) && "all values are expected to be pieces");
2073 assert(std::is_sorted(Values.begin(), Values.end()) &&
2074 "pieces are expected to be sorted");
2076 unsigned Offset = 0;
2077 for (auto Piece : Values) {
2078 DIVariable Var = Piece.getVariable();
2079 unsigned PieceOffset = Var.getPieceOffset();
2080 unsigned PieceSize = Var.getPieceSize();
2081 assert(Offset <= PieceOffset && "overlapping or duplicate pieces");
2082 if (Offset < PieceOffset) {
2083 // The DWARF spec seriously mandates pieces with no locations for gaps.
2084 Asm->EmitDwarfOpPiece(Streamer, (PieceOffset-Offset)*8);
2085 Offset += PieceOffset-Offset;
2088 Offset += PieceSize;
2090 const unsigned SizeOfByte = 8;
2091 assert(!Var.isIndirect() && "indirect address for piece");
2093 unsigned VarSize = Var.getSizeInBits(Map);
2094 assert(PieceSize+PieceOffset <= VarSize/SizeOfByte
2095 && "piece is larger than or outside of variable");
2096 assert(PieceSize*SizeOfByte != VarSize
2097 && "piece covers entire variable");
2099 if (Piece.isLocation() && Piece.getLoc().isReg())
2100 Asm->EmitDwarfRegOpPiece(Streamer,
2102 PieceSize*SizeOfByte);
2104 emitDebugLocValue(Streamer, Piece);
2105 Asm->EmitDwarfOpPiece(Streamer, PieceSize*SizeOfByte);
2111 void DwarfDebug::emitDebugLocEntry(ByteStreamer &Streamer,
2112 const DebugLocEntry &Entry) {
2113 const DebugLocEntry::Value Value = Entry.getValues()[0];
2114 if (Value.isVariablePiece())
2115 // Emit all pieces that belong to the same variable and range.
2116 return emitLocPieces(Streamer, TypeIdentifierMap, Entry.getValues());
2118 assert(Entry.getValues().size() == 1 && "only pieces may have >1 value");
2119 emitDebugLocValue(Streamer, Value);
2122 void DwarfDebug::emitDebugLocValue(ByteStreamer &Streamer,
2123 const DebugLocEntry::Value &Value) {
2124 DIVariable DV = Value.getVariable();
2126 if (Value.isInt()) {
2127 DIBasicType BTy(resolve(DV.getType()));
2128 if (BTy.Verify() && (BTy.getEncoding() == dwarf::DW_ATE_signed ||
2129 BTy.getEncoding() == dwarf::DW_ATE_signed_char)) {
2130 Streamer.EmitInt8(dwarf::DW_OP_consts, "DW_OP_consts");
2131 Streamer.EmitSLEB128(Value.getInt());
2133 Streamer.EmitInt8(dwarf::DW_OP_constu, "DW_OP_constu");
2134 Streamer.EmitULEB128(Value.getInt());
2136 } else if (Value.isLocation()) {
2137 MachineLocation Loc = Value.getLoc();
2138 if (!DV.hasComplexAddress())
2140 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2142 // Complex address entry.
2143 unsigned N = DV.getNumAddrElements();
2145 if (N >= 2 && DV.getAddrElement(0) == DIBuilder::OpPlus) {
2146 if (Loc.getOffset()) {
2148 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2149 Streamer.EmitInt8(dwarf::DW_OP_deref, "DW_OP_deref");
2150 Streamer.EmitInt8(dwarf::DW_OP_plus_uconst, "DW_OP_plus_uconst");
2151 Streamer.EmitSLEB128(DV.getAddrElement(1));
2153 // If first address element is OpPlus then emit
2154 // DW_OP_breg + Offset instead of DW_OP_reg + Offset.
2155 MachineLocation TLoc(Loc.getReg(), DV.getAddrElement(1));
2156 Asm->EmitDwarfRegOp(Streamer, TLoc, DV.isIndirect());
2160 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2163 // Emit remaining complex address elements.
2164 for (; i < N; ++i) {
2165 uint64_t Element = DV.getAddrElement(i);
2166 if (Element == DIBuilder::OpPlus) {
2167 Streamer.EmitInt8(dwarf::DW_OP_plus_uconst, "DW_OP_plus_uconst");
2168 Streamer.EmitULEB128(DV.getAddrElement(++i));
2169 } else if (Element == DIBuilder::OpDeref) {
2171 Streamer.EmitInt8(dwarf::DW_OP_deref, "DW_OP_deref");
2172 } else if (Element == DIBuilder::OpPiece) {
2174 // handled in emitDebugLocEntry.
2176 llvm_unreachable("unknown Opcode found in complex address");
2180 // else ... ignore constant fp. There is not any good way to
2181 // to represent them here in dwarf.
2185 void DwarfDebug::emitDebugLocEntryLocation(const DebugLocEntry &Entry) {
2186 Asm->OutStreamer.AddComment("Loc expr size");
2187 MCSymbol *begin = Asm->OutStreamer.getContext().CreateTempSymbol();
2188 MCSymbol *end = Asm->OutStreamer.getContext().CreateTempSymbol();
2189 Asm->EmitLabelDifference(end, begin, 2);
2190 Asm->OutStreamer.EmitLabel(begin);
2192 APByteStreamer Streamer(*Asm);
2193 emitDebugLocEntry(Streamer, Entry);
2195 Asm->OutStreamer.EmitLabel(end);
2198 // Emit locations into the debug loc section.
2199 void DwarfDebug::emitDebugLoc() {
2200 // Start the dwarf loc section.
2201 Asm->OutStreamer.SwitchSection(
2202 Asm->getObjFileLowering().getDwarfLocSection());
2203 unsigned char Size = Asm->getDataLayout().getPointerSize();
2204 for (const auto &DebugLoc : DotDebugLocEntries) {
2205 Asm->OutStreamer.EmitLabel(DebugLoc.Label);
2206 const DwarfCompileUnit *CU = DebugLoc.CU;
2207 assert(!CU->getRanges().empty());
2208 for (const auto &Entry : DebugLoc.List) {
2209 // Set up the range. This range is relative to the entry point of the
2210 // compile unit. This is a hard coded 0 for low_pc when we're emitting
2211 // ranges, or the DW_AT_low_pc on the compile unit otherwise.
2212 if (CU->getRanges().size() == 1) {
2213 // Grab the begin symbol from the first range as our base.
2214 const MCSymbol *Base = CU->getRanges()[0].getStart();
2215 Asm->EmitLabelDifference(Entry.getBeginSym(), Base, Size);
2216 Asm->EmitLabelDifference(Entry.getEndSym(), Base, Size);
2218 Asm->OutStreamer.EmitSymbolValue(Entry.getBeginSym(), Size);
2219 Asm->OutStreamer.EmitSymbolValue(Entry.getEndSym(), Size);
2222 emitDebugLocEntryLocation(Entry);
2224 Asm->OutStreamer.EmitIntValue(0, Size);
2225 Asm->OutStreamer.EmitIntValue(0, Size);
2229 void DwarfDebug::emitDebugLocDWO() {
2230 Asm->OutStreamer.SwitchSection(
2231 Asm->getObjFileLowering().getDwarfLocDWOSection());
2232 for (const auto &DebugLoc : DotDebugLocEntries) {
2233 Asm->OutStreamer.EmitLabel(DebugLoc.Label);
2234 for (const auto &Entry : DebugLoc.List) {
2235 // Just always use start_length for now - at least that's one address
2236 // rather than two. We could get fancier and try to, say, reuse an
2237 // address we know we've emitted elsewhere (the start of the function?
2238 // The start of the CU or CU subrange that encloses this range?)
2239 Asm->EmitInt8(dwarf::DW_LLE_start_length_entry);
2240 unsigned idx = AddrPool.getIndex(Entry.getBeginSym());
2241 Asm->EmitULEB128(idx);
2242 Asm->EmitLabelDifference(Entry.getEndSym(), Entry.getBeginSym(), 4);
2244 emitDebugLocEntryLocation(Entry);
2246 Asm->EmitInt8(dwarf::DW_LLE_end_of_list_entry);
2251 const MCSymbol *Start, *End;
2254 // Emit a debug aranges section, containing a CU lookup for any
2255 // address we can tie back to a CU.
2256 void DwarfDebug::emitDebugARanges() {
2257 // Start the dwarf aranges section.
2258 Asm->OutStreamer.SwitchSection(
2259 Asm->getObjFileLowering().getDwarfARangesSection());
2261 typedef DenseMap<DwarfCompileUnit *, std::vector<ArangeSpan>> SpansType;
2265 // Build a list of sections used.
2266 std::vector<const MCSection *> Sections;
2267 for (const auto &it : SectionMap) {
2268 const MCSection *Section = it.first;
2269 Sections.push_back(Section);
2272 // Sort the sections into order.
2273 // This is only done to ensure consistent output order across different runs.
2274 std::sort(Sections.begin(), Sections.end(), SectionSort);
2276 // Build a set of address spans, sorted by CU.
2277 for (const MCSection *Section : Sections) {
2278 SmallVector<SymbolCU, 8> &List = SectionMap[Section];
2279 if (List.size() < 2)
2282 // Sort the symbols by offset within the section.
2283 std::sort(List.begin(), List.end(),
2284 [&](const SymbolCU &A, const SymbolCU &B) {
2285 unsigned IA = A.Sym ? Asm->OutStreamer.GetSymbolOrder(A.Sym) : 0;
2286 unsigned IB = B.Sym ? Asm->OutStreamer.GetSymbolOrder(B.Sym) : 0;
2288 // Symbols with no order assigned should be placed at the end.
2289 // (e.g. section end labels)
2297 // If we have no section (e.g. common), just write out
2298 // individual spans for each symbol.
2300 for (const SymbolCU &Cur : List) {
2302 Span.Start = Cur.Sym;
2305 Spans[Cur.CU].push_back(Span);
2308 // Build spans between each label.
2309 const MCSymbol *StartSym = List[0].Sym;
2310 for (size_t n = 1, e = List.size(); n < e; n++) {
2311 const SymbolCU &Prev = List[n - 1];
2312 const SymbolCU &Cur = List[n];
2314 // Try and build the longest span we can within the same CU.
2315 if (Cur.CU != Prev.CU) {
2317 Span.Start = StartSym;
2319 Spans[Prev.CU].push_back(Span);
2326 unsigned PtrSize = Asm->getDataLayout().getPointerSize();
2328 // Build a list of CUs used.
2329 std::vector<DwarfCompileUnit *> CUs;
2330 for (const auto &it : Spans) {
2331 DwarfCompileUnit *CU = it.first;
2335 // Sort the CU list (again, to ensure consistent output order).
2336 std::sort(CUs.begin(), CUs.end(), [](const DwarfUnit *A, const DwarfUnit *B) {
2337 return A->getUniqueID() < B->getUniqueID();
2340 // Emit an arange table for each CU we used.
2341 for (DwarfCompileUnit *CU : CUs) {
2342 std::vector<ArangeSpan> &List = Spans[CU];
2344 // Emit size of content not including length itself.
2345 unsigned ContentSize =
2346 sizeof(int16_t) + // DWARF ARange version number
2347 sizeof(int32_t) + // Offset of CU in the .debug_info section
2348 sizeof(int8_t) + // Pointer Size (in bytes)
2349 sizeof(int8_t); // Segment Size (in bytes)
2351 unsigned TupleSize = PtrSize * 2;
2353 // 7.20 in the Dwarf specs requires the table to be aligned to a tuple.
2355 OffsetToAlignment(sizeof(int32_t) + ContentSize, TupleSize);
2357 ContentSize += Padding;
2358 ContentSize += (List.size() + 1) * TupleSize;
2360 // For each compile unit, write the list of spans it covers.
2361 Asm->OutStreamer.AddComment("Length of ARange Set");
2362 Asm->EmitInt32(ContentSize);
2363 Asm->OutStreamer.AddComment("DWARF Arange version number");
2364 Asm->EmitInt16(dwarf::DW_ARANGES_VERSION);
2365 Asm->OutStreamer.AddComment("Offset Into Debug Info Section");
2366 Asm->EmitSectionOffset(CU->getLocalLabelBegin(), CU->getLocalSectionSym());
2367 Asm->OutStreamer.AddComment("Address Size (in bytes)");
2368 Asm->EmitInt8(PtrSize);
2369 Asm->OutStreamer.AddComment("Segment Size (in bytes)");
2372 Asm->OutStreamer.EmitFill(Padding, 0xff);
2374 for (const ArangeSpan &Span : List) {
2375 Asm->EmitLabelReference(Span.Start, PtrSize);
2377 // Calculate the size as being from the span start to it's end.
2379 Asm->EmitLabelDifference(Span.End, Span.Start, PtrSize);
2381 // For symbols without an end marker (e.g. common), we
2382 // write a single arange entry containing just that one symbol.
2383 uint64_t Size = SymSize[Span.Start];
2387 Asm->OutStreamer.EmitIntValue(Size, PtrSize);
2391 Asm->OutStreamer.AddComment("ARange terminator");
2392 Asm->OutStreamer.EmitIntValue(0, PtrSize);
2393 Asm->OutStreamer.EmitIntValue(0, PtrSize);
2397 // Emit visible names into a debug ranges section.
2398 void DwarfDebug::emitDebugRanges() {
2399 // Start the dwarf ranges section.
2400 Asm->OutStreamer.SwitchSection(
2401 Asm->getObjFileLowering().getDwarfRangesSection());
2403 // Size for our labels.
2404 unsigned char Size = Asm->getDataLayout().getPointerSize();
2406 // Grab the specific ranges for the compile units in the module.
2407 for (const auto &I : CUMap) {
2408 DwarfCompileUnit *TheCU = I.second;
2410 // Iterate over the misc ranges for the compile units in the module.
2411 for (const RangeSpanList &List : TheCU->getRangeLists()) {
2412 // Emit our symbol so we can find the beginning of the range.
2413 Asm->OutStreamer.EmitLabel(List.getSym());
2415 for (const RangeSpan &Range : List.getRanges()) {
2416 const MCSymbol *Begin = Range.getStart();
2417 const MCSymbol *End = Range.getEnd();
2418 assert(Begin && "Range without a begin symbol?");
2419 assert(End && "Range without an end symbol?");
2420 if (TheCU->getRanges().size() == 1) {
2421 // Grab the begin symbol from the first range as our base.
2422 const MCSymbol *Base = TheCU->getRanges()[0].getStart();
2423 Asm->EmitLabelDifference(Begin, Base, Size);
2424 Asm->EmitLabelDifference(End, Base, Size);
2426 Asm->OutStreamer.EmitSymbolValue(Begin, Size);
2427 Asm->OutStreamer.EmitSymbolValue(End, Size);
2431 // And terminate the list with two 0 values.
2432 Asm->OutStreamer.EmitIntValue(0, Size);
2433 Asm->OutStreamer.EmitIntValue(0, Size);
2436 // Now emit a range for the CU itself.
2437 if (TheCU->getRanges().size() > 1) {
2438 Asm->OutStreamer.EmitLabel(
2439 Asm->GetTempSymbol("cu_ranges", TheCU->getUniqueID()));
2440 for (const RangeSpan &Range : TheCU->getRanges()) {
2441 const MCSymbol *Begin = Range.getStart();
2442 const MCSymbol *End = Range.getEnd();
2443 assert(Begin && "Range without a begin symbol?");
2444 assert(End && "Range without an end symbol?");
2445 Asm->OutStreamer.EmitSymbolValue(Begin, Size);
2446 Asm->OutStreamer.EmitSymbolValue(End, Size);
2448 // And terminate the list with two 0 values.
2449 Asm->OutStreamer.EmitIntValue(0, Size);
2450 Asm->OutStreamer.EmitIntValue(0, Size);
2455 // DWARF5 Experimental Separate Dwarf emitters.
2457 void DwarfDebug::initSkeletonUnit(const DwarfUnit &U, DIE &Die,
2458 std::unique_ptr<DwarfUnit> NewU) {
2459 NewU->addLocalString(Die, dwarf::DW_AT_GNU_dwo_name,
2460 U.getCUNode().getSplitDebugFilename());
2462 if (!CompilationDir.empty())
2463 NewU->addLocalString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
2465 addGnuPubAttributes(*NewU, Die);
2467 SkeletonHolder.addUnit(std::move(NewU));
2470 // This DIE has the following attributes: DW_AT_comp_dir, DW_AT_stmt_list,
2471 // DW_AT_low_pc, DW_AT_high_pc, DW_AT_ranges, DW_AT_dwo_name, DW_AT_dwo_id,
2472 // DW_AT_addr_base, DW_AT_ranges_base.
2473 DwarfCompileUnit &DwarfDebug::constructSkeletonCU(const DwarfCompileUnit &CU) {
2475 auto OwnedUnit = make_unique<DwarfCompileUnit>(
2476 CU.getUniqueID(), CU.getCUNode(), Asm, this, &SkeletonHolder);
2477 DwarfCompileUnit &NewCU = *OwnedUnit;
2478 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoSection(),
2479 DwarfInfoSectionSym);
2481 NewCU.initStmtList(DwarfLineSectionSym);
2483 initSkeletonUnit(CU, NewCU.getUnitDie(), std::move(OwnedUnit));
2488 // Emit the .debug_info.dwo section for separated dwarf. This contains the
2489 // compile units that would normally be in debug_info.
2490 void DwarfDebug::emitDebugInfoDWO() {
2491 assert(useSplitDwarf() && "No split dwarf debug info?");
2492 // Don't pass an abbrev symbol, using a constant zero instead so as not to
2493 // emit relocations into the dwo file.
2494 InfoHolder.emitUnits(this, /* AbbrevSymbol */ nullptr);
2497 // Emit the .debug_abbrev.dwo section for separated dwarf. This contains the
2498 // abbreviations for the .debug_info.dwo section.
2499 void DwarfDebug::emitDebugAbbrevDWO() {
2500 assert(useSplitDwarf() && "No split dwarf?");
2501 InfoHolder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevDWOSection());
2504 void DwarfDebug::emitDebugLineDWO() {
2505 assert(useSplitDwarf() && "No split dwarf?");
2506 Asm->OutStreamer.SwitchSection(
2507 Asm->getObjFileLowering().getDwarfLineDWOSection());
2508 SplitTypeUnitFileTable.Emit(Asm->OutStreamer);
2511 // Emit the .debug_str.dwo section for separated dwarf. This contains the
2512 // string section and is identical in format to traditional .debug_str
2514 void DwarfDebug::emitDebugStrDWO() {
2515 assert(useSplitDwarf() && "No split dwarf?");
2516 const MCSection *OffSec =
2517 Asm->getObjFileLowering().getDwarfStrOffDWOSection();
2518 InfoHolder.emitStrings(Asm->getObjFileLowering().getDwarfStrDWOSection(),
2522 MCDwarfDwoLineTable *DwarfDebug::getDwoLineTable(const DwarfCompileUnit &CU) {
2523 if (!useSplitDwarf())
2526 SplitTypeUnitFileTable.setCompilationDir(CU.getCUNode().getDirectory());
2527 return &SplitTypeUnitFileTable;
2530 static uint64_t makeTypeSignature(StringRef Identifier) {
2532 Hash.update(Identifier);
2533 // ... take the least significant 8 bytes and return those. Our MD5
2534 // implementation always returns its results in little endian, swap bytes
2536 MD5::MD5Result Result;
2538 return *reinterpret_cast<support::ulittle64_t *>(Result + 8);
2541 void DwarfDebug::addDwarfTypeUnitType(DwarfCompileUnit &CU,
2542 StringRef Identifier, DIE &RefDie,
2543 DICompositeType CTy) {
2544 // Fast path if we're building some type units and one has already used the
2545 // address pool we know we're going to throw away all this work anyway, so
2546 // don't bother building dependent types.
2547 if (!TypeUnitsUnderConstruction.empty() && AddrPool.hasBeenUsed())
2550 const DwarfTypeUnit *&TU = DwarfTypeUnits[CTy];
2552 CU.addDIETypeSignature(RefDie, *TU);
2556 bool TopLevelType = TypeUnitsUnderConstruction.empty();
2557 AddrPool.resetUsedFlag();
2559 auto OwnedUnit = make_unique<DwarfTypeUnit>(
2560 InfoHolder.getUnits().size() + TypeUnitsUnderConstruction.size(), CU, Asm,
2561 this, &InfoHolder, getDwoLineTable(CU));
2562 DwarfTypeUnit &NewTU = *OwnedUnit;
2563 DIE &UnitDie = NewTU.getUnitDie();
2565 TypeUnitsUnderConstruction.push_back(
2566 std::make_pair(std::move(OwnedUnit), CTy));
2568 NewTU.addUInt(UnitDie, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
2571 uint64_t Signature = makeTypeSignature(Identifier);
2572 NewTU.setTypeSignature(Signature);
2574 if (useSplitDwarf())
2575 NewTU.initSection(Asm->getObjFileLowering().getDwarfTypesDWOSection(),
2576 DwarfTypesDWOSectionSym);
2578 CU.applyStmtList(UnitDie);
2580 Asm->getObjFileLowering().getDwarfTypesSection(Signature));
2583 NewTU.setType(NewTU.createTypeDIE(CTy));
2586 auto TypeUnitsToAdd = std::move(TypeUnitsUnderConstruction);
2587 TypeUnitsUnderConstruction.clear();
2589 // Types referencing entries in the address table cannot be placed in type
2591 if (AddrPool.hasBeenUsed()) {
2593 // Remove all the types built while building this type.
2594 // This is pessimistic as some of these types might not be dependent on
2595 // the type that used an address.
2596 for (const auto &TU : TypeUnitsToAdd)
2597 DwarfTypeUnits.erase(TU.second);
2599 // Construct this type in the CU directly.
2600 // This is inefficient because all the dependent types will be rebuilt
2601 // from scratch, including building them in type units, discovering that
2602 // they depend on addresses, throwing them out and rebuilding them.
2603 CU.constructTypeDIE(RefDie, CTy);
2607 // If the type wasn't dependent on fission addresses, finish adding the type
2608 // and all its dependent types.
2609 for (auto &TU : TypeUnitsToAdd)
2610 InfoHolder.addUnit(std::move(TU.first));
2612 CU.addDIETypeSignature(RefDie, NewTU);
2615 void DwarfDebug::attachLowHighPC(DwarfCompileUnit &Unit, DIE &D,
2616 const MCSymbol *Begin, const MCSymbol *End) {
2617 assert(Begin && "Begin label should not be null!");
2618 assert(End && "End label should not be null!");
2619 assert(Begin->isDefined() && "Invalid starting label");
2620 assert(End->isDefined() && "Invalid end label");
2622 Unit.addLabelAddress(D, dwarf::DW_AT_low_pc, Begin);
2623 if (DwarfVersion < 4)
2624 Unit.addLabelAddress(D, dwarf::DW_AT_high_pc, End);
2626 Unit.addLabelDelta(D, dwarf::DW_AT_high_pc, End, Begin);
2629 // Accelerator table mutators - add each name along with its companion
2630 // DIE to the proper table while ensuring that the name that we're going
2631 // to reference is in the string table. We do this since the names we
2632 // add may not only be identical to the names in the DIE.
2633 void DwarfDebug::addAccelName(StringRef Name, const DIE &Die) {
2634 if (!useDwarfAccelTables())
2636 AccelNames.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2640 void DwarfDebug::addAccelObjC(StringRef Name, const DIE &Die) {
2641 if (!useDwarfAccelTables())
2643 AccelObjC.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2647 void DwarfDebug::addAccelNamespace(StringRef Name, const DIE &Die) {
2648 if (!useDwarfAccelTables())
2650 AccelNamespace.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2654 void DwarfDebug::addAccelType(StringRef Name, const DIE &Die, char Flags) {
2655 if (!useDwarfAccelTables())
2657 AccelTypes.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),