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 SmallVectorImpl<InsnRange>::const_iterator RI = Ranges.begin();
350 MCSymbol *End = getLabelAfterInsn(RI->second);
354 static void addSectionLabel(AsmPrinter &Asm, DwarfUnit &U, DIE &D,
355 dwarf::Attribute A, const MCSymbol *L,
356 const MCSymbol *Sec) {
357 if (Asm.MAI->doesDwarfUseRelocationsAcrossSections())
358 U.addSectionLabel(D, A, L);
360 U.addSectionDelta(D, A, L, Sec);
363 void DwarfDebug::addScopeRangeList(DwarfCompileUnit &TheCU, DIE &ScopeDIE,
364 const SmallVectorImpl<InsnRange> &Range) {
365 // Emit offset in .debug_range as a relocatable label. emitDIE will handle
366 // emitting it appropriately.
367 MCSymbol *RangeSym = Asm->GetTempSymbol("debug_ranges", GlobalRangeCount++);
369 // Under fission, ranges are specified by constant offsets relative to the
370 // CU's DW_AT_GNU_ranges_base.
372 TheCU.addSectionDelta(ScopeDIE, dwarf::DW_AT_ranges, RangeSym,
373 DwarfDebugRangeSectionSym);
375 addSectionLabel(*Asm, TheCU, ScopeDIE, dwarf::DW_AT_ranges, RangeSym,
376 DwarfDebugRangeSectionSym);
378 RangeSpanList List(RangeSym);
379 for (const InsnRange &R : Range) {
380 RangeSpan Span(getLabelBeforeInsn(R.first), getLabelAfterInsn(R.second));
381 List.addRange(std::move(Span));
384 // Add the range list to the set of ranges to be emitted.
385 TheCU.addRangeList(std::move(List));
388 void DwarfDebug::attachRangesOrLowHighPC(DwarfCompileUnit &TheCU, DIE &Die,
389 const SmallVectorImpl<InsnRange> &Ranges) {
390 assert(!Ranges.empty());
391 if (Ranges.size() == 1)
392 attachLowHighPC(TheCU, Die, getLabelBeforeInsn(Ranges.front().first),
393 getLabelAfterInsn(Ranges.front().second));
395 addScopeRangeList(TheCU, Die, Ranges);
398 // Construct new DW_TAG_lexical_block for this scope and attach
399 // DW_AT_low_pc/DW_AT_high_pc labels.
401 DwarfDebug::constructLexicalScopeDIE(DwarfCompileUnit &TheCU,
402 LexicalScope *Scope) {
403 if (isLexicalScopeDIENull(Scope))
406 auto ScopeDIE = make_unique<DIE>(dwarf::DW_TAG_lexical_block);
407 if (Scope->isAbstractScope())
410 attachRangesOrLowHighPC(TheCU, *ScopeDIE, Scope->getRanges());
415 // This scope represents inlined body of a function. Construct DIE to
416 // represent this concrete inlined copy of the function.
418 DwarfDebug::constructInlinedScopeDIE(DwarfCompileUnit &TheCU,
419 LexicalScope *Scope) {
420 assert(Scope->getScopeNode());
421 DIScope DS(Scope->getScopeNode());
422 DISubprogram InlinedSP = getDISubprogram(DS);
423 // Find the subprogram's DwarfCompileUnit in the SPMap in case the subprogram
424 // was inlined from another compile unit.
425 DIE *OriginDIE = AbstractSPDies[InlinedSP];
426 assert(OriginDIE && "Unable to find original DIE for an inlined subprogram.");
428 auto ScopeDIE = make_unique<DIE>(dwarf::DW_TAG_inlined_subroutine);
429 TheCU.addDIEEntry(*ScopeDIE, dwarf::DW_AT_abstract_origin, *OriginDIE);
431 attachRangesOrLowHighPC(TheCU, *ScopeDIE, Scope->getRanges());
433 InlinedSubprogramDIEs.insert(OriginDIE);
435 // Add the call site information to the DIE.
436 DILocation DL(Scope->getInlinedAt());
437 TheCU.addUInt(*ScopeDIE, dwarf::DW_AT_call_file, None,
438 TheCU.getOrCreateSourceID(DL.getFilename(), DL.getDirectory()));
439 TheCU.addUInt(*ScopeDIE, dwarf::DW_AT_call_line, None, DL.getLineNumber());
441 // Add name to the name table, we do this here because we're guaranteed
442 // to have concrete versions of our DW_TAG_inlined_subprogram nodes.
443 addSubprogramNames(InlinedSP, *ScopeDIE);
448 static std::unique_ptr<DIE> constructVariableDIE(DwarfCompileUnit &TheCU,
450 const LexicalScope &Scope,
451 DIE *&ObjectPointer) {
452 auto Var = TheCU.constructVariableDIE(DV, Scope.isAbstractScope());
453 if (DV.isObjectPointer())
454 ObjectPointer = Var.get();
458 DIE *DwarfDebug::createScopeChildrenDIE(
459 DwarfCompileUnit &TheCU, LexicalScope *Scope,
460 SmallVectorImpl<std::unique_ptr<DIE>> &Children) {
461 DIE *ObjectPointer = nullptr;
463 // Collect arguments for current function.
464 if (LScopes.isCurrentFunctionScope(Scope)) {
465 for (DbgVariable *ArgDV : CurrentFnArguments)
468 constructVariableDIE(TheCU, *ArgDV, *Scope, ObjectPointer));
470 // If this is a variadic function, add an unspecified parameter.
471 DISubprogram SP(Scope->getScopeNode());
472 DITypeArray FnArgs = SP.getType().getTypeArray();
473 // If we have a single element of null, it is a function that returns void.
474 // If we have more than one elements and the last one is null, it is a
475 // variadic function.
476 if (FnArgs.getNumElements() > 1 &&
477 !FnArgs.getElement(FnArgs.getNumElements() - 1))
479 make_unique<DIE>(dwarf::DW_TAG_unspecified_parameters));
482 // Collect lexical scope children first.
483 for (DbgVariable *DV : ScopeVariables.lookup(Scope))
484 Children.push_back(constructVariableDIE(TheCU, *DV, *Scope, ObjectPointer));
486 for (LexicalScope *LS : Scope->getChildren())
487 if (std::unique_ptr<DIE> Nested = constructScopeDIE(TheCU, LS))
488 Children.push_back(std::move(Nested));
489 return ObjectPointer;
492 void DwarfDebug::createAndAddScopeChildren(DwarfCompileUnit &TheCU,
493 LexicalScope *Scope, DIE &ScopeDIE) {
494 // We create children when the scope DIE is not null.
495 SmallVector<std::unique_ptr<DIE>, 8> Children;
496 if (DIE *ObjectPointer = createScopeChildrenDIE(TheCU, Scope, Children))
497 TheCU.addDIEEntry(ScopeDIE, dwarf::DW_AT_object_pointer, *ObjectPointer);
500 for (auto &I : Children)
501 ScopeDIE.addChild(std::move(I));
504 void DwarfDebug::constructAbstractSubprogramScopeDIE(DwarfCompileUnit &TheCU,
505 LexicalScope *Scope) {
506 assert(Scope && Scope->getScopeNode());
507 assert(Scope->isAbstractScope());
508 assert(!Scope->getInlinedAt());
510 DISubprogram SP(Scope->getScopeNode());
512 ProcessedSPNodes.insert(SP);
514 DIE *&AbsDef = AbstractSPDies[SP];
518 // Find the subprogram's DwarfCompileUnit in the SPMap in case the subprogram
519 // was inlined from another compile unit.
520 DwarfCompileUnit &SPCU = *SPMap[SP];
523 // Some of this is duplicated from DwarfUnit::getOrCreateSubprogramDIE, with
524 // the important distinction that the DIDescriptor is not associated with the
525 // DIE (since the DIDescriptor will be associated with the concrete DIE, if
526 // any). It could be refactored to some common utility function.
527 if (DISubprogram SPDecl = SP.getFunctionDeclaration()) {
528 ContextDIE = &SPCU.getUnitDie();
529 SPCU.getOrCreateSubprogramDIE(SPDecl);
531 ContextDIE = SPCU.getOrCreateContextDIE(resolve(SP.getContext()));
533 // Passing null as the associated DIDescriptor because the abstract definition
534 // shouldn't be found by lookup.
535 AbsDef = &SPCU.createAndAddDIE(dwarf::DW_TAG_subprogram, *ContextDIE,
537 SPCU.applySubprogramAttributesToDefinition(SP, *AbsDef);
539 SPCU.addUInt(*AbsDef, dwarf::DW_AT_inline, None, dwarf::DW_INL_inlined);
540 createAndAddScopeChildren(SPCU, Scope, *AbsDef);
543 DIE &DwarfDebug::constructSubprogramScopeDIE(DwarfCompileUnit &TheCU,
544 LexicalScope *Scope) {
545 assert(Scope && Scope->getScopeNode());
546 assert(!Scope->getInlinedAt());
547 assert(!Scope->isAbstractScope());
548 DISubprogram Sub(Scope->getScopeNode());
550 assert(Sub.isSubprogram());
552 ProcessedSPNodes.insert(Sub);
554 DIE &ScopeDIE = updateSubprogramScopeDIE(TheCU, Sub);
556 createAndAddScopeChildren(TheCU, Scope, ScopeDIE);
561 // Construct a DIE for this scope.
562 std::unique_ptr<DIE> DwarfDebug::constructScopeDIE(DwarfCompileUnit &TheCU,
563 LexicalScope *Scope) {
564 if (!Scope || !Scope->getScopeNode())
567 DIScope DS(Scope->getScopeNode());
569 assert((Scope->getInlinedAt() || !DS.isSubprogram()) &&
570 "Only handle inlined subprograms here, use "
571 "constructSubprogramScopeDIE for non-inlined "
574 SmallVector<std::unique_ptr<DIE>, 8> Children;
576 // We try to create the scope DIE first, then the children DIEs. This will
577 // avoid creating un-used children then removing them later when we find out
578 // the scope DIE is null.
579 std::unique_ptr<DIE> ScopeDIE;
580 if (Scope->getParent() && DS.isSubprogram()) {
581 ScopeDIE = constructInlinedScopeDIE(TheCU, Scope);
584 // We create children when the scope DIE is not null.
585 createScopeChildrenDIE(TheCU, Scope, Children);
587 // Early exit when we know the scope DIE is going to be null.
588 if (isLexicalScopeDIENull(Scope))
591 // We create children here when we know the scope DIE is not going to be
592 // null and the children will be added to the scope DIE.
593 createScopeChildrenDIE(TheCU, Scope, Children);
595 // There is no need to emit empty lexical block DIE.
596 std::pair<ImportedEntityMap::const_iterator,
597 ImportedEntityMap::const_iterator> Range =
598 std::equal_range(ScopesWithImportedEntities.begin(),
599 ScopesWithImportedEntities.end(),
600 std::pair<const MDNode *, const MDNode *>(DS, nullptr),
602 if (Children.empty() && Range.first == Range.second)
604 ScopeDIE = constructLexicalScopeDIE(TheCU, Scope);
605 assert(ScopeDIE && "Scope DIE should not be null.");
606 for (ImportedEntityMap::const_iterator i = Range.first; i != Range.second;
608 constructImportedEntityDIE(TheCU, i->second, *ScopeDIE);
612 for (auto &I : Children)
613 ScopeDIE->addChild(std::move(I));
618 void DwarfDebug::addGnuPubAttributes(DwarfUnit &U, DIE &D) const {
619 if (!GenerateGnuPubSections)
622 U.addFlag(D, dwarf::DW_AT_GNU_pubnames);
625 // Create new DwarfCompileUnit for the given metadata node with tag
626 // DW_TAG_compile_unit.
627 DwarfCompileUnit &DwarfDebug::constructDwarfCompileUnit(DICompileUnit DIUnit) {
628 StringRef FN = DIUnit.getFilename();
629 CompilationDir = DIUnit.getDirectory();
631 auto OwnedUnit = make_unique<DwarfCompileUnit>(
632 InfoHolder.getUnits().size(), DIUnit, Asm, this, &InfoHolder);
633 DwarfCompileUnit &NewCU = *OwnedUnit;
634 DIE &Die = NewCU.getUnitDie();
635 InfoHolder.addUnit(std::move(OwnedUnit));
637 // LTO with assembly output shares a single line table amongst multiple CUs.
638 // To avoid the compilation directory being ambiguous, let the line table
639 // explicitly describe the directory of all files, never relying on the
640 // compilation directory.
641 if (!Asm->OutStreamer.hasRawTextSupport() || SingleCU)
642 Asm->OutStreamer.getContext().setMCLineTableCompilationDir(
643 NewCU.getUniqueID(), CompilationDir);
645 NewCU.addString(Die, dwarf::DW_AT_producer, DIUnit.getProducer());
646 NewCU.addUInt(Die, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
647 DIUnit.getLanguage());
648 NewCU.addString(Die, dwarf::DW_AT_name, FN);
650 if (!useSplitDwarf()) {
651 NewCU.initStmtList(DwarfLineSectionSym);
653 // If we're using split dwarf the compilation dir is going to be in the
654 // skeleton CU and so we don't need to duplicate it here.
655 if (!CompilationDir.empty())
656 NewCU.addString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
658 addGnuPubAttributes(NewCU, Die);
661 if (DIUnit.isOptimized())
662 NewCU.addFlag(Die, dwarf::DW_AT_APPLE_optimized);
664 StringRef Flags = DIUnit.getFlags();
666 NewCU.addString(Die, dwarf::DW_AT_APPLE_flags, Flags);
668 if (unsigned RVer = DIUnit.getRunTimeVersion())
669 NewCU.addUInt(Die, dwarf::DW_AT_APPLE_major_runtime_vers,
670 dwarf::DW_FORM_data1, RVer);
675 if (useSplitDwarf()) {
676 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoDWOSection(),
677 DwarfInfoDWOSectionSym);
678 NewCU.setSkeleton(constructSkeletonCU(NewCU));
680 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoSection(),
681 DwarfInfoSectionSym);
683 CUMap.insert(std::make_pair(DIUnit, &NewCU));
684 CUDieMap.insert(std::make_pair(&Die, &NewCU));
688 void DwarfDebug::constructImportedEntityDIE(DwarfCompileUnit &TheCU,
690 DIImportedEntity Module(N);
691 assert(Module.Verify());
692 if (DIE *D = TheCU.getOrCreateContextDIE(Module.getContext()))
693 constructImportedEntityDIE(TheCU, Module, *D);
696 void DwarfDebug::constructImportedEntityDIE(DwarfCompileUnit &TheCU,
697 const MDNode *N, DIE &Context) {
698 DIImportedEntity Module(N);
699 assert(Module.Verify());
700 return constructImportedEntityDIE(TheCU, Module, Context);
703 void DwarfDebug::constructImportedEntityDIE(DwarfCompileUnit &TheCU,
704 const DIImportedEntity &Module,
706 assert(Module.Verify() &&
707 "Use one of the MDNode * overloads to handle invalid metadata");
708 DIE &IMDie = TheCU.createAndAddDIE(Module.getTag(), Context, Module);
710 DIDescriptor Entity = resolve(Module.getEntity());
711 if (Entity.isNameSpace())
712 EntityDie = TheCU.getOrCreateNameSpace(DINameSpace(Entity));
713 else if (Entity.isSubprogram())
714 EntityDie = TheCU.getOrCreateSubprogramDIE(DISubprogram(Entity));
715 else if (Entity.isType())
716 EntityDie = TheCU.getOrCreateTypeDIE(DIType(Entity));
718 EntityDie = TheCU.getDIE(Entity);
719 TheCU.addSourceLine(IMDie, Module.getLineNumber(),
720 Module.getContext().getFilename(),
721 Module.getContext().getDirectory());
722 TheCU.addDIEEntry(IMDie, dwarf::DW_AT_import, *EntityDie);
723 StringRef Name = Module.getName();
725 TheCU.addString(IMDie, dwarf::DW_AT_name, Name);
728 // Emit all Dwarf sections that should come prior to the content. Create
729 // global DIEs and emit initial debug info sections. This is invoked by
730 // the target AsmPrinter.
731 void DwarfDebug::beginModule() {
732 if (DisableDebugInfoPrinting)
735 const Module *M = MMI->getModule();
737 FunctionDIs = makeSubprogramMap(*M);
739 // If module has named metadata anchors then use them, otherwise scan the
740 // module using debug info finder to collect debug info.
741 NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
744 TypeIdentifierMap = generateDITypeIdentifierMap(CU_Nodes);
746 // Emit initial sections so we can reference labels later.
749 SingleCU = CU_Nodes->getNumOperands() == 1;
751 for (MDNode *N : CU_Nodes->operands()) {
752 DICompileUnit CUNode(N);
753 DwarfCompileUnit &CU = constructDwarfCompileUnit(CUNode);
754 DIArray ImportedEntities = CUNode.getImportedEntities();
755 for (unsigned i = 0, e = ImportedEntities.getNumElements(); i != e; ++i)
756 ScopesWithImportedEntities.push_back(std::make_pair(
757 DIImportedEntity(ImportedEntities.getElement(i)).getContext(),
758 ImportedEntities.getElement(i)));
759 std::sort(ScopesWithImportedEntities.begin(),
760 ScopesWithImportedEntities.end(), less_first());
761 DIArray GVs = CUNode.getGlobalVariables();
762 for (unsigned i = 0, e = GVs.getNumElements(); i != e; ++i)
763 CU.createGlobalVariableDIE(DIGlobalVariable(GVs.getElement(i)));
764 DIArray SPs = CUNode.getSubprograms();
765 for (unsigned i = 0, e = SPs.getNumElements(); i != e; ++i)
766 SPMap.insert(std::make_pair(SPs.getElement(i), &CU));
767 DIArray EnumTypes = CUNode.getEnumTypes();
768 for (unsigned i = 0, e = EnumTypes.getNumElements(); i != e; ++i) {
769 DIType Ty(EnumTypes.getElement(i));
770 // The enum types array by design contains pointers to
771 // MDNodes rather than DIRefs. Unique them here.
772 DIType UniqueTy(resolve(Ty.getRef()));
773 CU.getOrCreateTypeDIE(UniqueTy);
775 DIArray RetainedTypes = CUNode.getRetainedTypes();
776 for (unsigned i = 0, e = RetainedTypes.getNumElements(); i != e; ++i) {
777 DIType Ty(RetainedTypes.getElement(i));
778 // The retained types array by design contains pointers to
779 // MDNodes rather than DIRefs. Unique them here.
780 DIType UniqueTy(resolve(Ty.getRef()));
781 CU.getOrCreateTypeDIE(UniqueTy);
783 // Emit imported_modules last so that the relevant context is already
785 for (unsigned i = 0, e = ImportedEntities.getNumElements(); i != e; ++i)
786 constructImportedEntityDIE(CU, ImportedEntities.getElement(i));
789 // Tell MMI that we have debug info.
790 MMI->setDebugInfoAvailability(true);
792 // Prime section data.
793 SectionMap[Asm->getObjFileLowering().getTextSection()];
796 void DwarfDebug::finishVariableDefinitions() {
797 for (const auto &Var : ConcreteVariables) {
798 DIE *VariableDie = Var->getDIE();
800 // FIXME: Consider the time-space tradeoff of just storing the unit pointer
801 // in the ConcreteVariables list, rather than looking it up again here.
802 // DIE::getUnit isn't simple - it walks parent pointers, etc.
803 DwarfCompileUnit *Unit = lookupUnit(VariableDie->getUnit());
805 DbgVariable *AbsVar = getExistingAbstractVariable(Var->getVariable());
806 if (AbsVar && AbsVar->getDIE()) {
807 Unit->addDIEEntry(*VariableDie, dwarf::DW_AT_abstract_origin,
810 Unit->applyVariableAttributes(*Var, *VariableDie);
814 void DwarfDebug::finishSubprogramDefinitions() {
815 const Module *M = MMI->getModule();
817 NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
818 for (MDNode *N : CU_Nodes->operands()) {
819 DICompileUnit TheCU(N);
820 // Construct subprogram DIE and add variables DIEs.
821 DwarfCompileUnit *SPCU =
822 static_cast<DwarfCompileUnit *>(CUMap.lookup(TheCU));
823 DIArray Subprograms = TheCU.getSubprograms();
824 for (unsigned i = 0, e = Subprograms.getNumElements(); i != e; ++i) {
825 DISubprogram SP(Subprograms.getElement(i));
826 // Perhaps the subprogram is in another CU (such as due to comdat
827 // folding, etc), in which case ignore it here.
828 if (SPMap[SP] != SPCU)
830 DIE *D = SPCU->getDIE(SP);
831 if (DIE *AbsSPDIE = AbstractSPDies.lookup(SP)) {
833 // If this subprogram has an abstract definition, reference that
834 SPCU->addDIEEntry(*D, dwarf::DW_AT_abstract_origin, *AbsSPDIE);
837 // Lazily construct the subprogram if we didn't see either concrete or
838 // inlined versions during codegen.
839 D = SPCU->getOrCreateSubprogramDIE(SP);
840 // And attach the attributes
841 SPCU->applySubprogramAttributesToDefinition(SP, *D);
848 // Collect info for variables that were optimized out.
849 void DwarfDebug::collectDeadVariables() {
850 const Module *M = MMI->getModule();
852 if (NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu")) {
853 for (MDNode *N : CU_Nodes->operands()) {
854 DICompileUnit TheCU(N);
855 // Construct subprogram DIE and add variables DIEs.
856 DwarfCompileUnit *SPCU =
857 static_cast<DwarfCompileUnit *>(CUMap.lookup(TheCU));
858 assert(SPCU && "Unable to find Compile Unit!");
859 DIArray Subprograms = TheCU.getSubprograms();
860 for (unsigned i = 0, e = Subprograms.getNumElements(); i != e; ++i) {
861 DISubprogram SP(Subprograms.getElement(i));
862 if (ProcessedSPNodes.count(SP) != 0)
864 assert(SP.isSubprogram() &&
865 "CU's subprogram list contains a non-subprogram");
866 assert(SP.isDefinition() &&
867 "CU's subprogram list contains a subprogram declaration");
868 DIArray Variables = SP.getVariables();
869 if (Variables.getNumElements() == 0)
872 DIE *SPDIE = AbstractSPDies.lookup(SP);
874 SPDIE = SPCU->getDIE(SP);
876 for (unsigned vi = 0, ve = Variables.getNumElements(); vi != ve; ++vi) {
877 DIVariable DV(Variables.getElement(vi));
878 assert(DV.isVariable());
879 DbgVariable NewVar(DV, this);
880 auto VariableDie = SPCU->constructVariableDIE(NewVar);
881 SPCU->applyVariableAttributes(NewVar, *VariableDie);
882 SPDIE->addChild(std::move(VariableDie));
889 void DwarfDebug::finalizeModuleInfo() {
890 finishSubprogramDefinitions();
892 finishVariableDefinitions();
894 // Collect info for variables that were optimized out.
895 collectDeadVariables();
897 // Handle anything that needs to be done on a per-unit basis after
898 // all other generation.
899 for (const auto &TheU : getUnits()) {
900 // Emit DW_AT_containing_type attribute to connect types with their
901 // vtable holding type.
902 TheU->constructContainingTypeDIEs();
904 // Add CU specific attributes if we need to add any.
905 if (TheU->getUnitDie().getTag() == dwarf::DW_TAG_compile_unit) {
906 // If we're splitting the dwarf out now that we've got the entire
907 // CU then add the dwo id to it.
908 DwarfCompileUnit *SkCU =
909 static_cast<DwarfCompileUnit *>(TheU->getSkeleton());
910 if (useSplitDwarf()) {
911 // Emit a unique identifier for this CU.
912 uint64_t ID = DIEHash(Asm).computeCUSignature(TheU->getUnitDie());
913 TheU->addUInt(TheU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
914 dwarf::DW_FORM_data8, ID);
915 SkCU->addUInt(SkCU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
916 dwarf::DW_FORM_data8, ID);
918 // We don't keep track of which addresses are used in which CU so this
919 // is a bit pessimistic under LTO.
920 if (!AddrPool.isEmpty())
921 addSectionLabel(*Asm, *SkCU, SkCU->getUnitDie(),
922 dwarf::DW_AT_GNU_addr_base, DwarfAddrSectionSym,
923 DwarfAddrSectionSym);
924 if (!TheU->getRangeLists().empty())
925 addSectionLabel(*Asm, *SkCU, SkCU->getUnitDie(),
926 dwarf::DW_AT_GNU_ranges_base,
927 DwarfDebugRangeSectionSym, DwarfDebugRangeSectionSym);
930 // If we have code split among multiple sections or non-contiguous
931 // ranges of code then emit a DW_AT_ranges attribute on the unit that will
932 // remain in the .o file, otherwise add a DW_AT_low_pc.
933 // FIXME: We should use ranges allow reordering of code ala
934 // .subsections_via_symbols in mach-o. This would mean turning on
935 // ranges for all subprogram DIEs for mach-o.
936 DwarfCompileUnit &U =
937 SkCU ? *SkCU : static_cast<DwarfCompileUnit &>(*TheU);
938 unsigned NumRanges = TheU->getRanges().size();
941 addSectionLabel(*Asm, U, U.getUnitDie(), dwarf::DW_AT_ranges,
942 Asm->GetTempSymbol("cu_ranges", U.getUniqueID()),
943 DwarfDebugRangeSectionSym);
945 // A DW_AT_low_pc attribute may also be specified in combination with
946 // DW_AT_ranges to specify the default base address for use in
947 // location lists (see Section 2.6.2) and range lists (see Section
949 U.addUInt(U.getUnitDie(), dwarf::DW_AT_low_pc, dwarf::DW_FORM_addr,
952 RangeSpan &Range = TheU->getRanges().back();
953 attachLowHighPC(U, U.getUnitDie(), Range.getStart(), Range.getEnd());
959 // Compute DIE offsets and sizes.
960 InfoHolder.computeSizeAndOffsets();
962 SkeletonHolder.computeSizeAndOffsets();
965 void DwarfDebug::endSections() {
966 // Filter labels by section.
967 for (const SymbolCU &SCU : ArangeLabels) {
968 if (SCU.Sym->isInSection()) {
969 // Make a note of this symbol and it's section.
970 const MCSection *Section = &SCU.Sym->getSection();
971 if (!Section->getKind().isMetadata())
972 SectionMap[Section].push_back(SCU);
974 // Some symbols (e.g. common/bss on mach-o) can have no section but still
975 // appear in the output. This sucks as we rely on sections to build
976 // arange spans. We can do it without, but it's icky.
977 SectionMap[nullptr].push_back(SCU);
981 // Build a list of sections used.
982 std::vector<const MCSection *> Sections;
983 for (const auto &it : SectionMap) {
984 const MCSection *Section = it.first;
985 Sections.push_back(Section);
988 // Sort the sections into order.
989 // This is only done to ensure consistent output order across different runs.
990 std::sort(Sections.begin(), Sections.end(), SectionSort);
992 // Add terminating symbols for each section.
993 for (unsigned ID = 0, E = Sections.size(); ID != E; ID++) {
994 const MCSection *Section = Sections[ID];
995 MCSymbol *Sym = nullptr;
998 // We can't call MCSection::getLabelEndName, as it's only safe to do so
999 // if we know the section name up-front. For user-created sections, the
1000 // resulting label may not be valid to use as a label. (section names can
1001 // use a greater set of characters on some systems)
1002 Sym = Asm->GetTempSymbol("debug_end", ID);
1003 Asm->OutStreamer.SwitchSection(Section);
1004 Asm->OutStreamer.EmitLabel(Sym);
1007 // Insert a final terminator.
1008 SectionMap[Section].push_back(SymbolCU(nullptr, Sym));
1012 // Emit all Dwarf sections that should come after the content.
1013 void DwarfDebug::endModule() {
1014 assert(CurFn == nullptr);
1015 assert(CurMI == nullptr);
1020 // End any existing sections.
1021 // TODO: Does this need to happen?
1024 // Finalize the debug info for the module.
1025 finalizeModuleInfo();
1029 // Emit all the DIEs into a debug info section.
1032 // Corresponding abbreviations into a abbrev section.
1033 emitAbbreviations();
1035 // Emit info into a debug aranges section.
1036 if (GenerateARangeSection)
1039 // Emit info into a debug ranges section.
1042 if (useSplitDwarf()) {
1045 emitDebugAbbrevDWO();
1048 // Emit DWO addresses.
1049 AddrPool.emit(*Asm, Asm->getObjFileLowering().getDwarfAddrSection());
1051 // Emit info into a debug loc section.
1054 // Emit info into the dwarf accelerator table sections.
1055 if (useDwarfAccelTables()) {
1058 emitAccelNamespaces();
1062 // Emit the pubnames and pubtypes sections if requested.
1063 if (HasDwarfPubSections) {
1064 emitDebugPubNames(GenerateGnuPubSections);
1065 emitDebugPubTypes(GenerateGnuPubSections);
1070 AbstractVariables.clear();
1072 // Reset these for the next Module if we have one.
1076 // Find abstract variable, if any, associated with Var.
1077 DbgVariable *DwarfDebug::getExistingAbstractVariable(const DIVariable &DV,
1078 DIVariable &Cleansed) {
1079 LLVMContext &Ctx = DV->getContext();
1080 // More then one inlined variable corresponds to one abstract variable.
1081 // FIXME: This duplication of variables when inlining should probably be
1082 // removed. It's done to allow each DIVariable to describe its location
1083 // because the DebugLoc on the dbg.value/declare isn't accurate. We should
1084 // make it accurate then remove this duplication/cleansing stuff.
1085 Cleansed = cleanseInlinedVariable(DV, Ctx);
1086 auto I = AbstractVariables.find(Cleansed);
1087 if (I != AbstractVariables.end())
1088 return I->second.get();
1092 DbgVariable *DwarfDebug::getExistingAbstractVariable(const DIVariable &DV) {
1093 DIVariable Cleansed;
1094 return getExistingAbstractVariable(DV, Cleansed);
1097 void DwarfDebug::createAbstractVariable(const DIVariable &Var,
1098 LexicalScope *Scope) {
1099 auto AbsDbgVariable = make_unique<DbgVariable>(Var, this);
1100 addScopeVariable(Scope, AbsDbgVariable.get());
1101 AbstractVariables[Var] = std::move(AbsDbgVariable);
1104 void DwarfDebug::ensureAbstractVariableIsCreated(const DIVariable &DV,
1105 const MDNode *ScopeNode) {
1106 DIVariable Cleansed = DV;
1107 if (getExistingAbstractVariable(DV, Cleansed))
1110 createAbstractVariable(Cleansed, LScopes.getOrCreateAbstractScope(ScopeNode));
1114 DwarfDebug::ensureAbstractVariableIsCreatedIfScoped(const DIVariable &DV,
1115 const MDNode *ScopeNode) {
1116 DIVariable Cleansed = DV;
1117 if (getExistingAbstractVariable(DV, Cleansed))
1120 if (LexicalScope *Scope = LScopes.findAbstractScope(ScopeNode))
1121 createAbstractVariable(Cleansed, Scope);
1124 // If Var is a current function argument then add it to CurrentFnArguments list.
1125 bool DwarfDebug::addCurrentFnArgument(DbgVariable *Var, LexicalScope *Scope) {
1126 if (!LScopes.isCurrentFunctionScope(Scope))
1128 DIVariable DV = Var->getVariable();
1129 if (DV.getTag() != dwarf::DW_TAG_arg_variable)
1131 unsigned ArgNo = DV.getArgNumber();
1135 size_t Size = CurrentFnArguments.size();
1137 CurrentFnArguments.resize(CurFn->getFunction()->arg_size());
1138 // llvm::Function argument size is not good indicator of how many
1139 // arguments does the function have at source level.
1141 CurrentFnArguments.resize(ArgNo * 2);
1142 assert(!CurrentFnArguments[ArgNo - 1]);
1143 CurrentFnArguments[ArgNo - 1] = Var;
1147 // Collect variable information from side table maintained by MMI.
1148 void DwarfDebug::collectVariableInfoFromMMITable(
1149 SmallPtrSetImpl<const MDNode *> &Processed) {
1150 for (const auto &VI : MMI->getVariableDbgInfo()) {
1153 Processed.insert(VI.Var);
1154 DIVariable DV(VI.Var);
1155 LexicalScope *Scope = LScopes.findLexicalScope(VI.Loc);
1157 // If variable scope is not found then skip this variable.
1161 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
1162 ConcreteVariables.push_back(make_unique<DbgVariable>(DV, this));
1163 DbgVariable *RegVar = ConcreteVariables.back().get();
1164 RegVar->setFrameIndex(VI.Slot);
1165 addScopeVariable(Scope, RegVar);
1169 // Get .debug_loc entry for the instruction range starting at MI.
1170 static DebugLocEntry::Value getDebugLocValue(const MachineInstr *MI) {
1171 const MDNode *Var = MI->getDebugVariable();
1173 assert(MI->getNumOperands() == 3);
1174 if (MI->getOperand(0).isReg()) {
1175 MachineLocation MLoc;
1176 // If the second operand is an immediate, this is a
1177 // register-indirect address.
1178 if (!MI->getOperand(1).isImm())
1179 MLoc.set(MI->getOperand(0).getReg());
1181 MLoc.set(MI->getOperand(0).getReg(), MI->getOperand(1).getImm());
1182 return DebugLocEntry::Value(Var, MLoc);
1184 if (MI->getOperand(0).isImm())
1185 return DebugLocEntry::Value(Var, MI->getOperand(0).getImm());
1186 if (MI->getOperand(0).isFPImm())
1187 return DebugLocEntry::Value(Var, MI->getOperand(0).getFPImm());
1188 if (MI->getOperand(0).isCImm())
1189 return DebugLocEntry::Value(Var, MI->getOperand(0).getCImm());
1191 llvm_unreachable("Unexpected 3 operand DBG_VALUE instruction!");
1194 /// Determine whether two variable pieces overlap.
1195 static bool piecesOverlap(DIVariable P1, DIVariable P2) {
1196 if (!P1.isVariablePiece() || !P2.isVariablePiece())
1198 unsigned l1 = P1.getPieceOffset();
1199 unsigned l2 = P2.getPieceOffset();
1200 unsigned r1 = l1 + P1.getPieceSize();
1201 unsigned r2 = l2 + P2.getPieceSize();
1202 // True where [l1,r1[ and [r1,r2[ overlap.
1203 return (l1 < r2) && (l2 < r1);
1206 /// Build the location list for all DBG_VALUEs in the function that
1207 /// describe the same variable. If the ranges of several independent
1208 /// pieces of the same variable overlap partially, split them up and
1209 /// combine the ranges. The resulting DebugLocEntries are will have
1210 /// strict monotonically increasing begin addresses and will never
1215 // Ranges History [var, loc, piece ofs size]
1216 // 0 | [x, (reg0, piece 0, 32)]
1217 // 1 | | [x, (reg1, piece 32, 32)] <- IsPieceOfPrevEntry
1219 // 3 | [clobber reg0]
1220 // 4 [x, (mem, piece 0, 64)] <- overlapping with both previous pieces of x.
1224 // [0-1] [x, (reg0, piece 0, 32)]
1225 // [1-3] [x, (reg0, piece 0, 32), (reg1, piece 32, 32)]
1226 // [3-4] [x, (reg1, piece 32, 32)]
1227 // [4- ] [x, (mem, piece 0, 64)]
1229 DwarfDebug::buildLocationList(SmallVectorImpl<DebugLocEntry> &DebugLoc,
1230 const DbgValueHistoryMap::InstrRanges &Ranges) {
1231 SmallVector<DebugLocEntry::Value, 4> OpenRanges;
1233 for (auto I = Ranges.begin(), E = Ranges.end(); I != E; ++I) {
1234 const MachineInstr *Begin = I->first;
1235 const MachineInstr *End = I->second;
1236 assert(Begin->isDebugValue() && "Invalid History entry");
1238 // Check if a variable is inaccessible in this range.
1239 if (Begin->getNumOperands() > 1 &&
1240 Begin->getOperand(0).isReg() && !Begin->getOperand(0).getReg()) {
1245 // If this piece overlaps with any open ranges, truncate them.
1246 DIVariable DIVar = Begin->getDebugVariable();
1247 auto Last = std::remove_if(OpenRanges.begin(), OpenRanges.end(),
1248 [&](DebugLocEntry::Value R) {
1249 return piecesOverlap(DIVar, R.getVariable());
1251 OpenRanges.erase(Last, OpenRanges.end());
1253 const MCSymbol *StartLabel = getLabelBeforeInsn(Begin);
1254 assert(StartLabel && "Forgot label before DBG_VALUE starting a range!");
1256 const MCSymbol *EndLabel;
1258 EndLabel = getLabelAfterInsn(End);
1259 else if (std::next(I) == Ranges.end())
1260 EndLabel = FunctionEndSym;
1262 EndLabel = getLabelBeforeInsn(std::next(I)->first);
1263 assert(EndLabel && "Forgot label after instruction ending a range!");
1265 DEBUG(dbgs() << "DotDebugLoc: " << *Begin << "\n");
1267 auto Value = getDebugLocValue(Begin);
1268 DebugLocEntry Loc(StartLabel, EndLabel, Value);
1269 bool couldMerge = false;
1271 // If this is a piece, it may belong to the current DebugLocEntry.
1272 if (DIVar.isVariablePiece()) {
1273 // Add this value to the list of open ranges.
1274 OpenRanges.push_back(Value);
1276 // Attempt to add the piece to the last entry.
1277 if (!DebugLoc.empty())
1278 if (DebugLoc.back().MergeValues(Loc))
1283 // Need to add a new DebugLocEntry. Add all values from still
1284 // valid non-overlapping pieces.
1285 if (OpenRanges.size())
1286 Loc.addValues(OpenRanges);
1288 DebugLoc.push_back(std::move(Loc));
1291 // Attempt to coalesce the ranges of two otherwise identical
1293 auto CurEntry = DebugLoc.rbegin();
1294 auto PrevEntry = std::next(CurEntry);
1295 if (PrevEntry != DebugLoc.rend() && PrevEntry->MergeRanges(*CurEntry))
1296 DebugLoc.pop_back();
1298 DEBUG(dbgs() << "Values:\n";
1299 for (auto Value : CurEntry->getValues())
1300 Value.getVariable()->dump();
1301 dbgs() << "-----\n");
1306 // Find variables for each lexical scope.
1308 DwarfDebug::collectVariableInfo(SmallPtrSetImpl<const MDNode *> &Processed) {
1309 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1310 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1312 // Grab the variable info that was squirreled away in the MMI side-table.
1313 collectVariableInfoFromMMITable(Processed);
1315 for (const auto &I : DbgValues) {
1316 DIVariable DV(I.first);
1317 if (Processed.count(DV))
1320 // Instruction ranges, specifying where DV is accessible.
1321 const auto &Ranges = I.second;
1325 LexicalScope *Scope = nullptr;
1326 if (MDNode *IA = DV.getInlinedAt()) {
1327 DebugLoc DL = DebugLoc::getFromDILocation(IA);
1328 Scope = LScopes.findInlinedScope(DebugLoc::get(
1329 DL.getLine(), DL.getCol(), DV.getContext(), IA));
1331 Scope = LScopes.findLexicalScope(DV.getContext());
1332 // If variable scope is not found then skip this variable.
1336 Processed.insert(getEntireVariable(DV));
1337 const MachineInstr *MInsn = Ranges.front().first;
1338 assert(MInsn->isDebugValue() && "History must begin with debug value");
1339 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
1340 ConcreteVariables.push_back(make_unique<DbgVariable>(MInsn, this));
1341 DbgVariable *RegVar = ConcreteVariables.back().get();
1342 addScopeVariable(Scope, RegVar);
1344 // Check if the first DBG_VALUE is valid for the rest of the function.
1345 if (Ranges.size() == 1 && Ranges.front().second == nullptr)
1348 // Handle multiple DBG_VALUE instructions describing one variable.
1349 RegVar->setDotDebugLocOffset(DotDebugLocEntries.size());
1351 DotDebugLocEntries.resize(DotDebugLocEntries.size() + 1);
1352 DebugLocList &LocList = DotDebugLocEntries.back();
1355 Asm->GetTempSymbol("debug_loc", DotDebugLocEntries.size() - 1);
1357 // Build the location list for this variable.
1358 buildLocationList(LocList.List, Ranges);
1361 // Collect info for variables that were optimized out.
1362 DIArray Variables = DISubprogram(FnScope->getScopeNode()).getVariables();
1363 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1364 DIVariable DV(Variables.getElement(i));
1365 assert(DV.isVariable());
1366 if (!Processed.insert(DV))
1368 if (LexicalScope *Scope = LScopes.findLexicalScope(DV.getContext())) {
1369 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
1370 ConcreteVariables.push_back(make_unique<DbgVariable>(DV, this));
1371 addScopeVariable(Scope, ConcreteVariables.back().get());
1376 // Return Label preceding the instruction.
1377 MCSymbol *DwarfDebug::getLabelBeforeInsn(const MachineInstr *MI) {
1378 MCSymbol *Label = LabelsBeforeInsn.lookup(MI);
1379 assert(Label && "Didn't insert label before instruction");
1383 // Return Label immediately following the instruction.
1384 MCSymbol *DwarfDebug::getLabelAfterInsn(const MachineInstr *MI) {
1385 return LabelsAfterInsn.lookup(MI);
1388 // Process beginning of an instruction.
1389 void DwarfDebug::beginInstruction(const MachineInstr *MI) {
1390 assert(CurMI == nullptr);
1392 // Check if source location changes, but ignore DBG_VALUE locations.
1393 if (!MI->isDebugValue()) {
1394 DebugLoc DL = MI->getDebugLoc();
1395 if (DL != PrevInstLoc && (!DL.isUnknown() || UnknownLocations)) {
1398 if (DL == PrologEndLoc) {
1399 Flags |= DWARF2_FLAG_PROLOGUE_END;
1400 PrologEndLoc = DebugLoc();
1402 if (PrologEndLoc.isUnknown())
1403 Flags |= DWARF2_FLAG_IS_STMT;
1405 if (!DL.isUnknown()) {
1406 const MDNode *Scope = DL.getScope(Asm->MF->getFunction()->getContext());
1407 recordSourceLine(DL.getLine(), DL.getCol(), Scope, Flags);
1409 recordSourceLine(0, 0, nullptr, 0);
1413 // Insert labels where requested.
1414 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1415 LabelsBeforeInsn.find(MI);
1418 if (I == LabelsBeforeInsn.end())
1421 // Label already assigned.
1426 PrevLabel = MMI->getContext().CreateTempSymbol();
1427 Asm->OutStreamer.EmitLabel(PrevLabel);
1429 I->second = PrevLabel;
1432 // Process end of an instruction.
1433 void DwarfDebug::endInstruction() {
1434 assert(CurMI != nullptr);
1435 // Don't create a new label after DBG_VALUE instructions.
1436 // They don't generate code.
1437 if (!CurMI->isDebugValue())
1438 PrevLabel = nullptr;
1440 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1441 LabelsAfterInsn.find(CurMI);
1445 if (I == LabelsAfterInsn.end())
1448 // Label already assigned.
1452 // We need a label after this instruction.
1454 PrevLabel = MMI->getContext().CreateTempSymbol();
1455 Asm->OutStreamer.EmitLabel(PrevLabel);
1457 I->second = PrevLabel;
1460 // Each LexicalScope has first instruction and last instruction to mark
1461 // beginning and end of a scope respectively. Create an inverse map that list
1462 // scopes starts (and ends) with an instruction. One instruction may start (or
1463 // end) multiple scopes. Ignore scopes that are not reachable.
1464 void DwarfDebug::identifyScopeMarkers() {
1465 SmallVector<LexicalScope *, 4> WorkList;
1466 WorkList.push_back(LScopes.getCurrentFunctionScope());
1467 while (!WorkList.empty()) {
1468 LexicalScope *S = WorkList.pop_back_val();
1470 const SmallVectorImpl<LexicalScope *> &Children = S->getChildren();
1471 if (!Children.empty())
1472 WorkList.append(Children.begin(), Children.end());
1474 if (S->isAbstractScope())
1477 for (const InsnRange &R : S->getRanges()) {
1478 assert(R.first && "InsnRange does not have first instruction!");
1479 assert(R.second && "InsnRange does not have second instruction!");
1480 requestLabelBeforeInsn(R.first);
1481 requestLabelAfterInsn(R.second);
1486 static DebugLoc findPrologueEndLoc(const MachineFunction *MF) {
1487 // First known non-DBG_VALUE and non-frame setup location marks
1488 // the beginning of the function body.
1489 for (const auto &MBB : *MF)
1490 for (const auto &MI : MBB)
1491 if (!MI.isDebugValue() && !MI.getFlag(MachineInstr::FrameSetup) &&
1492 !MI.getDebugLoc().isUnknown())
1493 return MI.getDebugLoc();
1497 // Gather pre-function debug information. Assumes being called immediately
1498 // after the function entry point has been emitted.
1499 void DwarfDebug::beginFunction(const MachineFunction *MF) {
1502 // If there's no debug info for the function we're not going to do anything.
1503 if (!MMI->hasDebugInfo())
1506 auto DI = FunctionDIs.find(MF->getFunction());
1507 if (DI == FunctionDIs.end())
1510 // Grab the lexical scopes for the function, if we don't have any of those
1511 // then we're not going to be able to do anything.
1512 LScopes.initialize(*MF);
1513 if (LScopes.empty())
1516 assert(DbgValues.empty() && "DbgValues map wasn't cleaned!");
1518 // Make sure that each lexical scope will have a begin/end label.
1519 identifyScopeMarkers();
1521 // Set DwarfDwarfCompileUnitID in MCContext to the Compile Unit this function
1522 // belongs to so that we add to the correct per-cu line table in the
1524 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1525 // FnScope->getScopeNode() and DI->second should represent the same function,
1526 // though they may not be the same MDNode due to inline functions merged in
1527 // LTO where the debug info metadata still differs (either due to distinct
1528 // written differences - two versions of a linkonce_odr function
1529 // written/copied into two separate files, or some sub-optimal metadata that
1530 // isn't structurally identical (see: file path/name info from clang, which
1531 // includes the directory of the cpp file being built, even when the file name
1532 // is absolute (such as an <> lookup header)))
1533 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1534 assert(TheCU && "Unable to find compile unit!");
1535 if (Asm->OutStreamer.hasRawTextSupport())
1536 // Use a single line table if we are generating assembly.
1537 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1539 Asm->OutStreamer.getContext().setDwarfCompileUnitID(TheCU->getUniqueID());
1541 // Emit a label for the function so that we have a beginning address.
1542 FunctionBeginSym = Asm->GetTempSymbol("func_begin", Asm->getFunctionNumber());
1543 // Assumes in correct section after the entry point.
1544 Asm->OutStreamer.EmitLabel(FunctionBeginSym);
1546 // Calculate history for local variables.
1547 calculateDbgValueHistory(MF, Asm->TM.getSubtargetImpl()->getRegisterInfo(),
1550 // Request labels for the full history.
1551 for (const auto &I : DbgValues) {
1552 const auto &Ranges = I.second;
1556 // The first mention of a function argument gets the FunctionBeginSym
1557 // label, so arguments are visible when breaking at function entry.
1558 DIVariable DV(Ranges.front().first->getDebugVariable());
1559 if (DV.isVariable() && DV.getTag() == dwarf::DW_TAG_arg_variable &&
1560 getDISubprogram(DV.getContext()).describes(MF->getFunction())) {
1561 if (!DV.isVariablePiece())
1562 LabelsBeforeInsn[Ranges.front().first] = FunctionBeginSym;
1564 // Mark all non-overlapping initial pieces.
1565 for (auto I = Ranges.begin(); I != Ranges.end(); ++I) {
1566 DIVariable Piece = I->first->getDebugVariable();
1567 if (std::all_of(Ranges.begin(), I,
1568 [&](DbgValueHistoryMap::InstrRange Pred){
1569 return !piecesOverlap(Piece, Pred.first->getDebugVariable());
1571 LabelsBeforeInsn[I->first] = FunctionBeginSym;
1578 for (const auto &Range : Ranges) {
1579 requestLabelBeforeInsn(Range.first);
1581 requestLabelAfterInsn(Range.second);
1585 PrevInstLoc = DebugLoc();
1586 PrevLabel = FunctionBeginSym;
1588 // Record beginning of function.
1589 PrologEndLoc = findPrologueEndLoc(MF);
1590 if (!PrologEndLoc.isUnknown()) {
1591 DebugLoc FnStartDL =
1592 PrologEndLoc.getFnDebugLoc(MF->getFunction()->getContext());
1594 FnStartDL.getLine(), FnStartDL.getCol(),
1595 FnStartDL.getScope(MF->getFunction()->getContext()),
1596 // We'd like to list the prologue as "not statements" but GDB behaves
1597 // poorly if we do that. Revisit this with caution/GDB (7.5+) testing.
1598 DWARF2_FLAG_IS_STMT);
1602 void DwarfDebug::addScopeVariable(LexicalScope *LS, DbgVariable *Var) {
1603 if (addCurrentFnArgument(Var, LS))
1605 SmallVectorImpl<DbgVariable *> &Vars = ScopeVariables[LS];
1606 DIVariable DV = Var->getVariable();
1607 // Variables with positive arg numbers are parameters.
1608 if (unsigned ArgNum = DV.getArgNumber()) {
1609 // Keep all parameters in order at the start of the variable list to ensure
1610 // function types are correct (no out-of-order parameters)
1612 // This could be improved by only doing it for optimized builds (unoptimized
1613 // builds have the right order to begin with), searching from the back (this
1614 // would catch the unoptimized case quickly), or doing a binary search
1615 // rather than linear search.
1616 SmallVectorImpl<DbgVariable *>::iterator I = Vars.begin();
1617 while (I != Vars.end()) {
1618 unsigned CurNum = (*I)->getVariable().getArgNumber();
1619 // A local (non-parameter) variable has been found, insert immediately
1623 // A later indexed parameter has been found, insert immediately before it.
1624 if (CurNum > ArgNum)
1628 Vars.insert(I, Var);
1632 Vars.push_back(Var);
1635 // Gather and emit post-function debug information.
1636 void DwarfDebug::endFunction(const MachineFunction *MF) {
1637 // Every beginFunction(MF) call should be followed by an endFunction(MF) call,
1638 // though the beginFunction may not be called at all.
1639 // We should handle both cases.
1643 assert(CurFn == MF);
1644 assert(CurFn != nullptr);
1646 if (!MMI->hasDebugInfo() || LScopes.empty() ||
1647 !FunctionDIs.count(MF->getFunction())) {
1648 // If we don't have a lexical scope for this function then there will
1649 // be a hole in the range information. Keep note of this by setting the
1650 // previously used section to nullptr.
1651 PrevSection = nullptr;
1657 // Define end label for subprogram.
1658 FunctionEndSym = Asm->GetTempSymbol("func_end", Asm->getFunctionNumber());
1659 // Assumes in correct section after the entry point.
1660 Asm->OutStreamer.EmitLabel(FunctionEndSym);
1662 // Set DwarfDwarfCompileUnitID in MCContext to default value.
1663 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1665 SmallPtrSet<const MDNode *, 16> ProcessedVars;
1666 collectVariableInfo(ProcessedVars);
1668 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1669 DwarfCompileUnit &TheCU = *SPMap.lookup(FnScope->getScopeNode());
1671 // Construct abstract scopes.
1672 for (LexicalScope *AScope : LScopes.getAbstractScopesList()) {
1673 DISubprogram SP(AScope->getScopeNode());
1674 assert(SP.isSubprogram());
1675 // Collect info for variables that were optimized out.
1676 DIArray Variables = SP.getVariables();
1677 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1678 DIVariable DV(Variables.getElement(i));
1679 assert(DV && DV.isVariable());
1680 if (!ProcessedVars.insert(DV))
1682 ensureAbstractVariableIsCreated(DV, DV.getContext());
1684 constructAbstractSubprogramScopeDIE(TheCU, AScope);
1687 DIE &CurFnDIE = constructSubprogramScopeDIE(TheCU, FnScope);
1688 if (!CurFn->getTarget().Options.DisableFramePointerElim(*CurFn))
1689 TheCU.addFlag(CurFnDIE, dwarf::DW_AT_APPLE_omit_frame_ptr);
1691 // Add the range of this function to the list of ranges for the CU.
1692 RangeSpan Span(FunctionBeginSym, FunctionEndSym);
1693 TheCU.addRange(std::move(Span));
1694 PrevSection = Asm->getCurrentSection();
1698 // Ownership of DbgVariables is a bit subtle - ScopeVariables owns all the
1699 // DbgVariables except those that are also in AbstractVariables (since they
1700 // can be used cross-function)
1701 ScopeVariables.clear();
1702 CurrentFnArguments.clear();
1704 LabelsBeforeInsn.clear();
1705 LabelsAfterInsn.clear();
1706 PrevLabel = nullptr;
1710 // Register a source line with debug info. Returns the unique label that was
1711 // emitted and which provides correspondence to the source line list.
1712 void DwarfDebug::recordSourceLine(unsigned Line, unsigned Col, const MDNode *S,
1717 unsigned Discriminator = 0;
1718 if (DIScope Scope = DIScope(S)) {
1719 assert(Scope.isScope());
1720 Fn = Scope.getFilename();
1721 Dir = Scope.getDirectory();
1722 if (Scope.isLexicalBlockFile())
1723 Discriminator = DILexicalBlockFile(S).getDiscriminator();
1725 unsigned CUID = Asm->OutStreamer.getContext().getDwarfCompileUnitID();
1726 Src = static_cast<DwarfCompileUnit &>(*InfoHolder.getUnits()[CUID])
1727 .getOrCreateSourceID(Fn, Dir);
1729 Asm->OutStreamer.EmitDwarfLocDirective(Src, Line, Col, Flags, 0,
1733 //===----------------------------------------------------------------------===//
1735 //===----------------------------------------------------------------------===//
1737 // Emit initial Dwarf sections with a label at the start of each one.
1738 void DwarfDebug::emitSectionLabels() {
1739 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
1741 // Dwarf sections base addresses.
1742 DwarfInfoSectionSym =
1743 emitSectionSym(Asm, TLOF.getDwarfInfoSection(), "section_info");
1744 if (useSplitDwarf()) {
1745 DwarfInfoDWOSectionSym =
1746 emitSectionSym(Asm, TLOF.getDwarfInfoDWOSection(), "section_info_dwo");
1747 DwarfTypesDWOSectionSym =
1748 emitSectionSym(Asm, TLOF.getDwarfTypesDWOSection(), "section_types_dwo");
1750 DwarfAbbrevSectionSym =
1751 emitSectionSym(Asm, TLOF.getDwarfAbbrevSection(), "section_abbrev");
1752 if (useSplitDwarf())
1753 DwarfAbbrevDWOSectionSym = emitSectionSym(
1754 Asm, TLOF.getDwarfAbbrevDWOSection(), "section_abbrev_dwo");
1755 if (GenerateARangeSection)
1756 emitSectionSym(Asm, TLOF.getDwarfARangesSection());
1758 DwarfLineSectionSym =
1759 emitSectionSym(Asm, TLOF.getDwarfLineSection(), "section_line");
1760 if (GenerateGnuPubSections) {
1761 DwarfGnuPubNamesSectionSym =
1762 emitSectionSym(Asm, TLOF.getDwarfGnuPubNamesSection());
1763 DwarfGnuPubTypesSectionSym =
1764 emitSectionSym(Asm, TLOF.getDwarfGnuPubTypesSection());
1765 } else if (HasDwarfPubSections) {
1766 emitSectionSym(Asm, TLOF.getDwarfPubNamesSection());
1767 emitSectionSym(Asm, TLOF.getDwarfPubTypesSection());
1770 DwarfStrSectionSym =
1771 emitSectionSym(Asm, TLOF.getDwarfStrSection(), "info_string");
1772 if (useSplitDwarf()) {
1773 DwarfStrDWOSectionSym =
1774 emitSectionSym(Asm, TLOF.getDwarfStrDWOSection(), "skel_string");
1775 DwarfAddrSectionSym =
1776 emitSectionSym(Asm, TLOF.getDwarfAddrSection(), "addr_sec");
1777 DwarfDebugLocSectionSym =
1778 emitSectionSym(Asm, TLOF.getDwarfLocDWOSection(), "skel_loc");
1780 DwarfDebugLocSectionSym =
1781 emitSectionSym(Asm, TLOF.getDwarfLocSection(), "section_debug_loc");
1782 DwarfDebugRangeSectionSym =
1783 emitSectionSym(Asm, TLOF.getDwarfRangesSection(), "debug_range");
1786 // Recursively emits a debug information entry.
1787 void DwarfDebug::emitDIE(DIE &Die) {
1788 // Get the abbreviation for this DIE.
1789 const DIEAbbrev &Abbrev = Die.getAbbrev();
1791 // Emit the code (index) for the abbreviation.
1792 if (Asm->isVerbose())
1793 Asm->OutStreamer.AddComment("Abbrev [" + Twine(Abbrev.getNumber()) +
1794 "] 0x" + Twine::utohexstr(Die.getOffset()) +
1795 ":0x" + Twine::utohexstr(Die.getSize()) + " " +
1796 dwarf::TagString(Abbrev.getTag()));
1797 Asm->EmitULEB128(Abbrev.getNumber());
1799 const SmallVectorImpl<DIEValue *> &Values = Die.getValues();
1800 const SmallVectorImpl<DIEAbbrevData> &AbbrevData = Abbrev.getData();
1802 // Emit the DIE attribute values.
1803 for (unsigned i = 0, N = Values.size(); i < N; ++i) {
1804 dwarf::Attribute Attr = AbbrevData[i].getAttribute();
1805 dwarf::Form Form = AbbrevData[i].getForm();
1806 assert(Form && "Too many attributes for DIE (check abbreviation)");
1808 if (Asm->isVerbose()) {
1809 Asm->OutStreamer.AddComment(dwarf::AttributeString(Attr));
1810 if (Attr == dwarf::DW_AT_accessibility)
1811 Asm->OutStreamer.AddComment(dwarf::AccessibilityString(
1812 cast<DIEInteger>(Values[i])->getValue()));
1815 // Emit an attribute using the defined form.
1816 Values[i]->EmitValue(Asm, Form);
1819 // Emit the DIE children if any.
1820 if (Abbrev.hasChildren()) {
1821 for (auto &Child : Die.getChildren())
1824 Asm->OutStreamer.AddComment("End Of Children Mark");
1829 // Emit the debug info section.
1830 void DwarfDebug::emitDebugInfo() {
1831 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1833 Holder.emitUnits(this, DwarfAbbrevSectionSym);
1836 // Emit the abbreviation section.
1837 void DwarfDebug::emitAbbreviations() {
1838 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1840 Holder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevSection());
1843 // Emit the last address of the section and the end of the line matrix.
1844 void DwarfDebug::emitEndOfLineMatrix(unsigned SectionEnd) {
1845 // Define last address of section.
1846 Asm->OutStreamer.AddComment("Extended Op");
1849 Asm->OutStreamer.AddComment("Op size");
1850 Asm->EmitInt8(Asm->getDataLayout().getPointerSize() + 1);
1851 Asm->OutStreamer.AddComment("DW_LNE_set_address");
1852 Asm->EmitInt8(dwarf::DW_LNE_set_address);
1854 Asm->OutStreamer.AddComment("Section end label");
1856 Asm->OutStreamer.EmitSymbolValue(
1857 Asm->GetTempSymbol("section_end", SectionEnd),
1858 Asm->getDataLayout().getPointerSize());
1860 // Mark end of matrix.
1861 Asm->OutStreamer.AddComment("DW_LNE_end_sequence");
1867 // Emit visible names into a hashed accelerator table section.
1868 void DwarfDebug::emitAccelNames() {
1869 AccelNames.FinalizeTable(Asm, "Names");
1870 Asm->OutStreamer.SwitchSection(
1871 Asm->getObjFileLowering().getDwarfAccelNamesSection());
1872 MCSymbol *SectionBegin = Asm->GetTempSymbol("names_begin");
1873 Asm->OutStreamer.EmitLabel(SectionBegin);
1875 // Emit the full data.
1876 AccelNames.Emit(Asm, SectionBegin, &InfoHolder);
1879 // Emit objective C classes and categories into a hashed accelerator table
1881 void DwarfDebug::emitAccelObjC() {
1882 AccelObjC.FinalizeTable(Asm, "ObjC");
1883 Asm->OutStreamer.SwitchSection(
1884 Asm->getObjFileLowering().getDwarfAccelObjCSection());
1885 MCSymbol *SectionBegin = Asm->GetTempSymbol("objc_begin");
1886 Asm->OutStreamer.EmitLabel(SectionBegin);
1888 // Emit the full data.
1889 AccelObjC.Emit(Asm, SectionBegin, &InfoHolder);
1892 // Emit namespace dies into a hashed accelerator table.
1893 void DwarfDebug::emitAccelNamespaces() {
1894 AccelNamespace.FinalizeTable(Asm, "namespac");
1895 Asm->OutStreamer.SwitchSection(
1896 Asm->getObjFileLowering().getDwarfAccelNamespaceSection());
1897 MCSymbol *SectionBegin = Asm->GetTempSymbol("namespac_begin");
1898 Asm->OutStreamer.EmitLabel(SectionBegin);
1900 // Emit the full data.
1901 AccelNamespace.Emit(Asm, SectionBegin, &InfoHolder);
1904 // Emit type dies into a hashed accelerator table.
1905 void DwarfDebug::emitAccelTypes() {
1907 AccelTypes.FinalizeTable(Asm, "types");
1908 Asm->OutStreamer.SwitchSection(
1909 Asm->getObjFileLowering().getDwarfAccelTypesSection());
1910 MCSymbol *SectionBegin = Asm->GetTempSymbol("types_begin");
1911 Asm->OutStreamer.EmitLabel(SectionBegin);
1913 // Emit the full data.
1914 AccelTypes.Emit(Asm, SectionBegin, &InfoHolder);
1917 // Public name handling.
1918 // The format for the various pubnames:
1920 // dwarf pubnames - offset/name pairs where the offset is the offset into the CU
1921 // for the DIE that is named.
1923 // gnu pubnames - offset/index value/name tuples where the offset is the offset
1924 // into the CU and the index value is computed according to the type of value
1925 // for the DIE that is named.
1927 // For type units the offset is the offset of the skeleton DIE. For split dwarf
1928 // it's the offset within the debug_info/debug_types dwo section, however, the
1929 // reference in the pubname header doesn't change.
1931 /// computeIndexValue - Compute the gdb index value for the DIE and CU.
1932 static dwarf::PubIndexEntryDescriptor computeIndexValue(DwarfUnit *CU,
1934 dwarf::GDBIndexEntryLinkage Linkage = dwarf::GIEL_STATIC;
1936 // We could have a specification DIE that has our most of our knowledge,
1937 // look for that now.
1938 DIEValue *SpecVal = Die->findAttribute(dwarf::DW_AT_specification);
1940 DIE &SpecDIE = cast<DIEEntry>(SpecVal)->getEntry();
1941 if (SpecDIE.findAttribute(dwarf::DW_AT_external))
1942 Linkage = dwarf::GIEL_EXTERNAL;
1943 } else if (Die->findAttribute(dwarf::DW_AT_external))
1944 Linkage = dwarf::GIEL_EXTERNAL;
1946 switch (Die->getTag()) {
1947 case dwarf::DW_TAG_class_type:
1948 case dwarf::DW_TAG_structure_type:
1949 case dwarf::DW_TAG_union_type:
1950 case dwarf::DW_TAG_enumeration_type:
1951 return dwarf::PubIndexEntryDescriptor(
1952 dwarf::GIEK_TYPE, CU->getLanguage() != dwarf::DW_LANG_C_plus_plus
1953 ? dwarf::GIEL_STATIC
1954 : dwarf::GIEL_EXTERNAL);
1955 case dwarf::DW_TAG_typedef:
1956 case dwarf::DW_TAG_base_type:
1957 case dwarf::DW_TAG_subrange_type:
1958 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_TYPE, dwarf::GIEL_STATIC);
1959 case dwarf::DW_TAG_namespace:
1960 return dwarf::GIEK_TYPE;
1961 case dwarf::DW_TAG_subprogram:
1962 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_FUNCTION, Linkage);
1963 case dwarf::DW_TAG_constant:
1964 case dwarf::DW_TAG_variable:
1965 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE, Linkage);
1966 case dwarf::DW_TAG_enumerator:
1967 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE,
1968 dwarf::GIEL_STATIC);
1970 return dwarf::GIEK_NONE;
1974 /// emitDebugPubNames - Emit visible names into a debug pubnames section.
1976 void DwarfDebug::emitDebugPubNames(bool GnuStyle) {
1977 const MCSection *PSec =
1978 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubNamesSection()
1979 : Asm->getObjFileLowering().getDwarfPubNamesSection();
1981 emitDebugPubSection(GnuStyle, PSec, "Names", &DwarfUnit::getGlobalNames);
1984 void DwarfDebug::emitDebugPubSection(
1985 bool GnuStyle, const MCSection *PSec, StringRef Name,
1986 const StringMap<const DIE *> &(DwarfUnit::*Accessor)() const) {
1987 for (const auto &NU : CUMap) {
1988 DwarfCompileUnit *TheU = NU.second;
1990 const auto &Globals = (TheU->*Accessor)();
1992 if (Globals.empty())
1995 if (auto Skeleton = static_cast<DwarfCompileUnit *>(TheU->getSkeleton()))
1997 unsigned ID = TheU->getUniqueID();
1999 // Start the dwarf pubnames section.
2000 Asm->OutStreamer.SwitchSection(PSec);
2003 Asm->OutStreamer.AddComment("Length of Public " + Name + " Info");
2004 MCSymbol *BeginLabel = Asm->GetTempSymbol("pub" + Name + "_begin", ID);
2005 MCSymbol *EndLabel = Asm->GetTempSymbol("pub" + Name + "_end", ID);
2006 Asm->EmitLabelDifference(EndLabel, BeginLabel, 4);
2008 Asm->OutStreamer.EmitLabel(BeginLabel);
2010 Asm->OutStreamer.AddComment("DWARF Version");
2011 Asm->EmitInt16(dwarf::DW_PUBNAMES_VERSION);
2013 Asm->OutStreamer.AddComment("Offset of Compilation Unit Info");
2014 Asm->EmitSectionOffset(TheU->getLabelBegin(), TheU->getSectionSym());
2016 Asm->OutStreamer.AddComment("Compilation Unit Length");
2017 Asm->EmitLabelDifference(TheU->getLabelEnd(), TheU->getLabelBegin(), 4);
2019 // Emit the pubnames for this compilation unit.
2020 for (const auto &GI : Globals) {
2021 const char *Name = GI.getKeyData();
2022 const DIE *Entity = GI.second;
2024 Asm->OutStreamer.AddComment("DIE offset");
2025 Asm->EmitInt32(Entity->getOffset());
2028 dwarf::PubIndexEntryDescriptor Desc = computeIndexValue(TheU, Entity);
2029 Asm->OutStreamer.AddComment(
2030 Twine("Kind: ") + dwarf::GDBIndexEntryKindString(Desc.Kind) + ", " +
2031 dwarf::GDBIndexEntryLinkageString(Desc.Linkage));
2032 Asm->EmitInt8(Desc.toBits());
2035 Asm->OutStreamer.AddComment("External Name");
2036 Asm->OutStreamer.EmitBytes(StringRef(Name, GI.getKeyLength() + 1));
2039 Asm->OutStreamer.AddComment("End Mark");
2041 Asm->OutStreamer.EmitLabel(EndLabel);
2045 void DwarfDebug::emitDebugPubTypes(bool GnuStyle) {
2046 const MCSection *PSec =
2047 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubTypesSection()
2048 : Asm->getObjFileLowering().getDwarfPubTypesSection();
2050 emitDebugPubSection(GnuStyle, PSec, "Types", &DwarfUnit::getGlobalTypes);
2053 // Emit visible names into a debug str section.
2054 void DwarfDebug::emitDebugStr() {
2055 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
2056 Holder.emitStrings(Asm->getObjFileLowering().getDwarfStrSection());
2059 /// Emits an optimal (=sorted) sequence of DW_OP_pieces.
2060 void DwarfDebug::emitLocPieces(ByteStreamer &Streamer,
2061 const DITypeIdentifierMap &Map,
2062 ArrayRef<DebugLocEntry::Value> Values) {
2063 assert(std::all_of(Values.begin(), Values.end(), [](DebugLocEntry::Value P) {
2064 return P.isVariablePiece();
2065 }) && "all values are expected to be pieces");
2066 assert(std::is_sorted(Values.begin(), Values.end()) &&
2067 "pieces are expected to be sorted");
2069 unsigned Offset = 0;
2070 for (auto Piece : Values) {
2071 DIVariable Var = Piece.getVariable();
2072 unsigned PieceOffset = Var.getPieceOffset();
2073 unsigned PieceSize = Var.getPieceSize();
2074 assert(Offset <= PieceOffset && "overlapping or duplicate pieces");
2075 if (Offset < PieceOffset) {
2076 // The DWARF spec seriously mandates pieces with no locations for gaps.
2077 Asm->EmitDwarfOpPiece(Streamer, (PieceOffset-Offset)*8);
2078 Offset += PieceOffset-Offset;
2081 Offset += PieceSize;
2083 const unsigned SizeOfByte = 8;
2084 assert(!Var.isIndirect() && "indirect address for piece");
2086 unsigned VarSize = Var.getSizeInBits(Map);
2087 assert(PieceSize+PieceOffset <= VarSize/SizeOfByte
2088 && "piece is larger than or outside of variable");
2089 assert(PieceSize*SizeOfByte != VarSize
2090 && "piece covers entire variable");
2092 if (Piece.isLocation() && Piece.getLoc().isReg())
2093 Asm->EmitDwarfRegOpPiece(Streamer,
2095 PieceSize*SizeOfByte);
2097 emitDebugLocValue(Streamer, Piece);
2098 Asm->EmitDwarfOpPiece(Streamer, PieceSize*SizeOfByte);
2104 void DwarfDebug::emitDebugLocEntry(ByteStreamer &Streamer,
2105 const DebugLocEntry &Entry) {
2106 const DebugLocEntry::Value Value = Entry.getValues()[0];
2107 if (Value.isVariablePiece())
2108 // Emit all pieces that belong to the same variable and range.
2109 return emitLocPieces(Streamer, TypeIdentifierMap, Entry.getValues());
2111 assert(Entry.getValues().size() == 1 && "only pieces may have >1 value");
2112 emitDebugLocValue(Streamer, Value);
2115 void DwarfDebug::emitDebugLocValue(ByteStreamer &Streamer,
2116 const DebugLocEntry::Value &Value) {
2117 DIVariable DV = Value.getVariable();
2119 if (Value.isInt()) {
2120 DIBasicType BTy(resolve(DV.getType()));
2121 if (BTy.Verify() && (BTy.getEncoding() == dwarf::DW_ATE_signed ||
2122 BTy.getEncoding() == dwarf::DW_ATE_signed_char)) {
2123 Streamer.EmitInt8(dwarf::DW_OP_consts, "DW_OP_consts");
2124 Streamer.EmitSLEB128(Value.getInt());
2126 Streamer.EmitInt8(dwarf::DW_OP_constu, "DW_OP_constu");
2127 Streamer.EmitULEB128(Value.getInt());
2129 } else if (Value.isLocation()) {
2130 MachineLocation Loc = Value.getLoc();
2131 if (!DV.hasComplexAddress())
2133 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2135 // Complex address entry.
2136 unsigned N = DV.getNumAddrElements();
2138 if (N >= 2 && DV.getAddrElement(0) == DIBuilder::OpPlus) {
2139 if (Loc.getOffset()) {
2141 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2142 Streamer.EmitInt8(dwarf::DW_OP_deref, "DW_OP_deref");
2143 Streamer.EmitInt8(dwarf::DW_OP_plus_uconst, "DW_OP_plus_uconst");
2144 Streamer.EmitSLEB128(DV.getAddrElement(1));
2146 // If first address element is OpPlus then emit
2147 // DW_OP_breg + Offset instead of DW_OP_reg + Offset.
2148 MachineLocation TLoc(Loc.getReg(), DV.getAddrElement(1));
2149 Asm->EmitDwarfRegOp(Streamer, TLoc, DV.isIndirect());
2153 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2156 // Emit remaining complex address elements.
2157 for (; i < N; ++i) {
2158 uint64_t Element = DV.getAddrElement(i);
2159 if (Element == DIBuilder::OpPlus) {
2160 Streamer.EmitInt8(dwarf::DW_OP_plus_uconst, "DW_OP_plus_uconst");
2161 Streamer.EmitULEB128(DV.getAddrElement(++i));
2162 } else if (Element == DIBuilder::OpDeref) {
2164 Streamer.EmitInt8(dwarf::DW_OP_deref, "DW_OP_deref");
2165 } else if (Element == DIBuilder::OpPiece) {
2167 // handled in emitDebugLocEntry.
2169 llvm_unreachable("unknown Opcode found in complex address");
2173 // else ... ignore constant fp. There is not any good way to
2174 // to represent them here in dwarf.
2178 void DwarfDebug::emitDebugLocEntryLocation(const DebugLocEntry &Entry) {
2179 Asm->OutStreamer.AddComment("Loc expr size");
2180 MCSymbol *begin = Asm->OutStreamer.getContext().CreateTempSymbol();
2181 MCSymbol *end = Asm->OutStreamer.getContext().CreateTempSymbol();
2182 Asm->EmitLabelDifference(end, begin, 2);
2183 Asm->OutStreamer.EmitLabel(begin);
2185 APByteStreamer Streamer(*Asm);
2186 emitDebugLocEntry(Streamer, Entry);
2188 Asm->OutStreamer.EmitLabel(end);
2191 // Emit locations into the debug loc section.
2192 void DwarfDebug::emitDebugLoc() {
2193 // Start the dwarf loc section.
2194 Asm->OutStreamer.SwitchSection(
2195 Asm->getObjFileLowering().getDwarfLocSection());
2196 unsigned char Size = Asm->getDataLayout().getPointerSize();
2197 for (const auto &DebugLoc : DotDebugLocEntries) {
2198 Asm->OutStreamer.EmitLabel(DebugLoc.Label);
2199 const DwarfCompileUnit *CU = DebugLoc.CU;
2200 assert(!CU->getRanges().empty());
2201 for (const auto &Entry : DebugLoc.List) {
2202 // Set up the range. This range is relative to the entry point of the
2203 // compile unit. This is a hard coded 0 for low_pc when we're emitting
2204 // ranges, or the DW_AT_low_pc on the compile unit otherwise.
2205 if (CU->getRanges().size() == 1) {
2206 // Grab the begin symbol from the first range as our base.
2207 const MCSymbol *Base = CU->getRanges()[0].getStart();
2208 Asm->EmitLabelDifference(Entry.getBeginSym(), Base, Size);
2209 Asm->EmitLabelDifference(Entry.getEndSym(), Base, Size);
2211 Asm->OutStreamer.EmitSymbolValue(Entry.getBeginSym(), Size);
2212 Asm->OutStreamer.EmitSymbolValue(Entry.getEndSym(), Size);
2215 emitDebugLocEntryLocation(Entry);
2217 Asm->OutStreamer.EmitIntValue(0, Size);
2218 Asm->OutStreamer.EmitIntValue(0, Size);
2222 void DwarfDebug::emitDebugLocDWO() {
2223 Asm->OutStreamer.SwitchSection(
2224 Asm->getObjFileLowering().getDwarfLocDWOSection());
2225 for (const auto &DebugLoc : DotDebugLocEntries) {
2226 Asm->OutStreamer.EmitLabel(DebugLoc.Label);
2227 for (const auto &Entry : DebugLoc.List) {
2228 // Just always use start_length for now - at least that's one address
2229 // rather than two. We could get fancier and try to, say, reuse an
2230 // address we know we've emitted elsewhere (the start of the function?
2231 // The start of the CU or CU subrange that encloses this range?)
2232 Asm->EmitInt8(dwarf::DW_LLE_start_length_entry);
2233 unsigned idx = AddrPool.getIndex(Entry.getBeginSym());
2234 Asm->EmitULEB128(idx);
2235 Asm->EmitLabelDifference(Entry.getEndSym(), Entry.getBeginSym(), 4);
2237 emitDebugLocEntryLocation(Entry);
2239 Asm->EmitInt8(dwarf::DW_LLE_end_of_list_entry);
2244 const MCSymbol *Start, *End;
2247 // Emit a debug aranges section, containing a CU lookup for any
2248 // address we can tie back to a CU.
2249 void DwarfDebug::emitDebugARanges() {
2250 // Start the dwarf aranges section.
2251 Asm->OutStreamer.SwitchSection(
2252 Asm->getObjFileLowering().getDwarfARangesSection());
2254 typedef DenseMap<DwarfCompileUnit *, std::vector<ArangeSpan>> SpansType;
2258 // Build a list of sections used.
2259 std::vector<const MCSection *> Sections;
2260 for (const auto &it : SectionMap) {
2261 const MCSection *Section = it.first;
2262 Sections.push_back(Section);
2265 // Sort the sections into order.
2266 // This is only done to ensure consistent output order across different runs.
2267 std::sort(Sections.begin(), Sections.end(), SectionSort);
2269 // Build a set of address spans, sorted by CU.
2270 for (const MCSection *Section : Sections) {
2271 SmallVector<SymbolCU, 8> &List = SectionMap[Section];
2272 if (List.size() < 2)
2275 // Sort the symbols by offset within the section.
2276 std::sort(List.begin(), List.end(),
2277 [&](const SymbolCU &A, const SymbolCU &B) {
2278 unsigned IA = A.Sym ? Asm->OutStreamer.GetSymbolOrder(A.Sym) : 0;
2279 unsigned IB = B.Sym ? Asm->OutStreamer.GetSymbolOrder(B.Sym) : 0;
2281 // Symbols with no order assigned should be placed at the end.
2282 // (e.g. section end labels)
2290 // If we have no section (e.g. common), just write out
2291 // individual spans for each symbol.
2293 for (const SymbolCU &Cur : List) {
2295 Span.Start = Cur.Sym;
2298 Spans[Cur.CU].push_back(Span);
2301 // Build spans between each label.
2302 const MCSymbol *StartSym = List[0].Sym;
2303 for (size_t n = 1, e = List.size(); n < e; n++) {
2304 const SymbolCU &Prev = List[n - 1];
2305 const SymbolCU &Cur = List[n];
2307 // Try and build the longest span we can within the same CU.
2308 if (Cur.CU != Prev.CU) {
2310 Span.Start = StartSym;
2312 Spans[Prev.CU].push_back(Span);
2319 unsigned PtrSize = Asm->getDataLayout().getPointerSize();
2321 // Build a list of CUs used.
2322 std::vector<DwarfCompileUnit *> CUs;
2323 for (const auto &it : Spans) {
2324 DwarfCompileUnit *CU = it.first;
2328 // Sort the CU list (again, to ensure consistent output order).
2329 std::sort(CUs.begin(), CUs.end(), [](const DwarfUnit *A, const DwarfUnit *B) {
2330 return A->getUniqueID() < B->getUniqueID();
2333 // Emit an arange table for each CU we used.
2334 for (DwarfCompileUnit *CU : CUs) {
2335 std::vector<ArangeSpan> &List = Spans[CU];
2337 // Emit size of content not including length itself.
2338 unsigned ContentSize =
2339 sizeof(int16_t) + // DWARF ARange version number
2340 sizeof(int32_t) + // Offset of CU in the .debug_info section
2341 sizeof(int8_t) + // Pointer Size (in bytes)
2342 sizeof(int8_t); // Segment Size (in bytes)
2344 unsigned TupleSize = PtrSize * 2;
2346 // 7.20 in the Dwarf specs requires the table to be aligned to a tuple.
2348 OffsetToAlignment(sizeof(int32_t) + ContentSize, TupleSize);
2350 ContentSize += Padding;
2351 ContentSize += (List.size() + 1) * TupleSize;
2353 // For each compile unit, write the list of spans it covers.
2354 Asm->OutStreamer.AddComment("Length of ARange Set");
2355 Asm->EmitInt32(ContentSize);
2356 Asm->OutStreamer.AddComment("DWARF Arange version number");
2357 Asm->EmitInt16(dwarf::DW_ARANGES_VERSION);
2358 Asm->OutStreamer.AddComment("Offset Into Debug Info Section");
2359 Asm->EmitSectionOffset(CU->getLocalLabelBegin(), CU->getLocalSectionSym());
2360 Asm->OutStreamer.AddComment("Address Size (in bytes)");
2361 Asm->EmitInt8(PtrSize);
2362 Asm->OutStreamer.AddComment("Segment Size (in bytes)");
2365 Asm->OutStreamer.EmitFill(Padding, 0xff);
2367 for (const ArangeSpan &Span : List) {
2368 Asm->EmitLabelReference(Span.Start, PtrSize);
2370 // Calculate the size as being from the span start to it's end.
2372 Asm->EmitLabelDifference(Span.End, Span.Start, PtrSize);
2374 // For symbols without an end marker (e.g. common), we
2375 // write a single arange entry containing just that one symbol.
2376 uint64_t Size = SymSize[Span.Start];
2380 Asm->OutStreamer.EmitIntValue(Size, PtrSize);
2384 Asm->OutStreamer.AddComment("ARange terminator");
2385 Asm->OutStreamer.EmitIntValue(0, PtrSize);
2386 Asm->OutStreamer.EmitIntValue(0, PtrSize);
2390 // Emit visible names into a debug ranges section.
2391 void DwarfDebug::emitDebugRanges() {
2392 // Start the dwarf ranges section.
2393 Asm->OutStreamer.SwitchSection(
2394 Asm->getObjFileLowering().getDwarfRangesSection());
2396 // Size for our labels.
2397 unsigned char Size = Asm->getDataLayout().getPointerSize();
2399 // Grab the specific ranges for the compile units in the module.
2400 for (const auto &I : CUMap) {
2401 DwarfCompileUnit *TheCU = I.second;
2403 // Iterate over the misc ranges for the compile units in the module.
2404 for (const RangeSpanList &List : TheCU->getRangeLists()) {
2405 // Emit our symbol so we can find the beginning of the range.
2406 Asm->OutStreamer.EmitLabel(List.getSym());
2408 for (const RangeSpan &Range : List.getRanges()) {
2409 const MCSymbol *Begin = Range.getStart();
2410 const MCSymbol *End = Range.getEnd();
2411 assert(Begin && "Range without a begin symbol?");
2412 assert(End && "Range without an end symbol?");
2413 if (TheCU->getRanges().size() == 1) {
2414 // Grab the begin symbol from the first range as our base.
2415 const MCSymbol *Base = TheCU->getRanges()[0].getStart();
2416 Asm->EmitLabelDifference(Begin, Base, Size);
2417 Asm->EmitLabelDifference(End, Base, Size);
2419 Asm->OutStreamer.EmitSymbolValue(Begin, Size);
2420 Asm->OutStreamer.EmitSymbolValue(End, Size);
2424 // And terminate the list with two 0 values.
2425 Asm->OutStreamer.EmitIntValue(0, Size);
2426 Asm->OutStreamer.EmitIntValue(0, Size);
2429 // Now emit a range for the CU itself.
2430 if (TheCU->getRanges().size() > 1) {
2431 Asm->OutStreamer.EmitLabel(
2432 Asm->GetTempSymbol("cu_ranges", TheCU->getUniqueID()));
2433 for (const RangeSpan &Range : TheCU->getRanges()) {
2434 const MCSymbol *Begin = Range.getStart();
2435 const MCSymbol *End = Range.getEnd();
2436 assert(Begin && "Range without a begin symbol?");
2437 assert(End && "Range without an end symbol?");
2438 Asm->OutStreamer.EmitSymbolValue(Begin, Size);
2439 Asm->OutStreamer.EmitSymbolValue(End, Size);
2441 // And terminate the list with two 0 values.
2442 Asm->OutStreamer.EmitIntValue(0, Size);
2443 Asm->OutStreamer.EmitIntValue(0, Size);
2448 // DWARF5 Experimental Separate Dwarf emitters.
2450 void DwarfDebug::initSkeletonUnit(const DwarfUnit &U, DIE &Die,
2451 std::unique_ptr<DwarfUnit> NewU) {
2452 NewU->addLocalString(Die, dwarf::DW_AT_GNU_dwo_name,
2453 U.getCUNode().getSplitDebugFilename());
2455 if (!CompilationDir.empty())
2456 NewU->addLocalString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
2458 addGnuPubAttributes(*NewU, Die);
2460 SkeletonHolder.addUnit(std::move(NewU));
2463 // This DIE has the following attributes: DW_AT_comp_dir, DW_AT_stmt_list,
2464 // DW_AT_low_pc, DW_AT_high_pc, DW_AT_ranges, DW_AT_dwo_name, DW_AT_dwo_id,
2465 // DW_AT_addr_base, DW_AT_ranges_base.
2466 DwarfCompileUnit &DwarfDebug::constructSkeletonCU(const DwarfCompileUnit &CU) {
2468 auto OwnedUnit = make_unique<DwarfCompileUnit>(
2469 CU.getUniqueID(), CU.getCUNode(), Asm, this, &SkeletonHolder);
2470 DwarfCompileUnit &NewCU = *OwnedUnit;
2471 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoSection(),
2472 DwarfInfoSectionSym);
2474 NewCU.initStmtList(DwarfLineSectionSym);
2476 initSkeletonUnit(CU, NewCU.getUnitDie(), std::move(OwnedUnit));
2481 // Emit the .debug_info.dwo section for separated dwarf. This contains the
2482 // compile units that would normally be in debug_info.
2483 void DwarfDebug::emitDebugInfoDWO() {
2484 assert(useSplitDwarf() && "No split dwarf debug info?");
2485 // Don't pass an abbrev symbol, using a constant zero instead so as not to
2486 // emit relocations into the dwo file.
2487 InfoHolder.emitUnits(this, /* AbbrevSymbol */ nullptr);
2490 // Emit the .debug_abbrev.dwo section for separated dwarf. This contains the
2491 // abbreviations for the .debug_info.dwo section.
2492 void DwarfDebug::emitDebugAbbrevDWO() {
2493 assert(useSplitDwarf() && "No split dwarf?");
2494 InfoHolder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevDWOSection());
2497 void DwarfDebug::emitDebugLineDWO() {
2498 assert(useSplitDwarf() && "No split dwarf?");
2499 Asm->OutStreamer.SwitchSection(
2500 Asm->getObjFileLowering().getDwarfLineDWOSection());
2501 SplitTypeUnitFileTable.Emit(Asm->OutStreamer);
2504 // Emit the .debug_str.dwo section for separated dwarf. This contains the
2505 // string section and is identical in format to traditional .debug_str
2507 void DwarfDebug::emitDebugStrDWO() {
2508 assert(useSplitDwarf() && "No split dwarf?");
2509 const MCSection *OffSec =
2510 Asm->getObjFileLowering().getDwarfStrOffDWOSection();
2511 const MCSymbol *StrSym = DwarfStrSectionSym;
2512 InfoHolder.emitStrings(Asm->getObjFileLowering().getDwarfStrDWOSection(),
2516 MCDwarfDwoLineTable *DwarfDebug::getDwoLineTable(const DwarfCompileUnit &CU) {
2517 if (!useSplitDwarf())
2520 SplitTypeUnitFileTable.setCompilationDir(CU.getCUNode().getDirectory());
2521 return &SplitTypeUnitFileTable;
2524 static uint64_t makeTypeSignature(StringRef Identifier) {
2526 Hash.update(Identifier);
2527 // ... take the least significant 8 bytes and return those. Our MD5
2528 // implementation always returns its results in little endian, swap bytes
2530 MD5::MD5Result Result;
2532 return *reinterpret_cast<support::ulittle64_t *>(Result + 8);
2535 void DwarfDebug::addDwarfTypeUnitType(DwarfCompileUnit &CU,
2536 StringRef Identifier, DIE &RefDie,
2537 DICompositeType CTy) {
2538 // Fast path if we're building some type units and one has already used the
2539 // address pool we know we're going to throw away all this work anyway, so
2540 // don't bother building dependent types.
2541 if (!TypeUnitsUnderConstruction.empty() && AddrPool.hasBeenUsed())
2544 const DwarfTypeUnit *&TU = DwarfTypeUnits[CTy];
2546 CU.addDIETypeSignature(RefDie, *TU);
2550 bool TopLevelType = TypeUnitsUnderConstruction.empty();
2551 AddrPool.resetUsedFlag();
2553 auto OwnedUnit = make_unique<DwarfTypeUnit>(
2554 InfoHolder.getUnits().size() + TypeUnitsUnderConstruction.size(), CU, Asm,
2555 this, &InfoHolder, getDwoLineTable(CU));
2556 DwarfTypeUnit &NewTU = *OwnedUnit;
2557 DIE &UnitDie = NewTU.getUnitDie();
2559 TypeUnitsUnderConstruction.push_back(
2560 std::make_pair(std::move(OwnedUnit), CTy));
2562 NewTU.addUInt(UnitDie, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
2565 uint64_t Signature = makeTypeSignature(Identifier);
2566 NewTU.setTypeSignature(Signature);
2568 if (useSplitDwarf())
2569 NewTU.initSection(Asm->getObjFileLowering().getDwarfTypesDWOSection(),
2570 DwarfTypesDWOSectionSym);
2572 CU.applyStmtList(UnitDie);
2574 Asm->getObjFileLowering().getDwarfTypesSection(Signature));
2577 NewTU.setType(NewTU.createTypeDIE(CTy));
2580 auto TypeUnitsToAdd = std::move(TypeUnitsUnderConstruction);
2581 TypeUnitsUnderConstruction.clear();
2583 // Types referencing entries in the address table cannot be placed in type
2585 if (AddrPool.hasBeenUsed()) {
2587 // Remove all the types built while building this type.
2588 // This is pessimistic as some of these types might not be dependent on
2589 // the type that used an address.
2590 for (const auto &TU : TypeUnitsToAdd)
2591 DwarfTypeUnits.erase(TU.second);
2593 // Construct this type in the CU directly.
2594 // This is inefficient because all the dependent types will be rebuilt
2595 // from scratch, including building them in type units, discovering that
2596 // they depend on addresses, throwing them out and rebuilding them.
2597 CU.constructTypeDIE(RefDie, CTy);
2601 // If the type wasn't dependent on fission addresses, finish adding the type
2602 // and all its dependent types.
2603 for (auto &TU : TypeUnitsToAdd)
2604 InfoHolder.addUnit(std::move(TU.first));
2606 CU.addDIETypeSignature(RefDie, NewTU);
2609 void DwarfDebug::attachLowHighPC(DwarfCompileUnit &Unit, DIE &D,
2610 const MCSymbol *Begin, const MCSymbol *End) {
2611 assert(Begin && "Begin label should not be null!");
2612 assert(End && "End label should not be null!");
2613 assert(Begin->isDefined() && "Invalid starting label");
2614 assert(End->isDefined() && "Invalid end label");
2616 Unit.addLabelAddress(D, dwarf::DW_AT_low_pc, Begin);
2617 if (DwarfVersion < 4)
2618 Unit.addLabelAddress(D, dwarf::DW_AT_high_pc, End);
2620 Unit.addLabelDelta(D, dwarf::DW_AT_high_pc, End, Begin);
2623 // Accelerator table mutators - add each name along with its companion
2624 // DIE to the proper table while ensuring that the name that we're going
2625 // to reference is in the string table. We do this since the names we
2626 // add may not only be identical to the names in the DIE.
2627 void DwarfDebug::addAccelName(StringRef Name, const DIE &Die) {
2628 if (!useDwarfAccelTables())
2630 AccelNames.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2634 void DwarfDebug::addAccelObjC(StringRef Name, const DIE &Die) {
2635 if (!useDwarfAccelTables())
2637 AccelObjC.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2641 void DwarfDebug::addAccelNamespace(StringRef Name, const DIE &Die) {
2642 if (!useDwarfAccelTables())
2644 AccelNamespace.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2648 void DwarfDebug::addAccelType(StringRef Name, const DIE &Die, char Flags) {
2649 if (!useDwarfAccelTables())
2651 AccelTypes.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),