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();
799 // FIXME: There shouldn't be any variables without DIEs.
802 // FIXME: Consider the time-space tradeoff of just storing the unit pointer
803 // in the ConcreteVariables list, rather than looking it up again here.
804 // DIE::getUnit isn't simple - it walks parent pointers, etc.
805 DwarfCompileUnit *Unit = lookupUnit(VariableDie->getUnit());
807 DbgVariable *AbsVar = getExistingAbstractVariable(Var->getVariable());
808 if (AbsVar && AbsVar->getDIE()) {
809 Unit->addDIEEntry(*VariableDie, dwarf::DW_AT_abstract_origin,
812 Unit->applyVariableAttributes(*Var, *VariableDie);
816 void DwarfDebug::finishSubprogramDefinitions() {
817 const Module *M = MMI->getModule();
819 NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
820 for (MDNode *N : CU_Nodes->operands()) {
821 DICompileUnit TheCU(N);
822 // Construct subprogram DIE and add variables DIEs.
823 DwarfCompileUnit *SPCU =
824 static_cast<DwarfCompileUnit *>(CUMap.lookup(TheCU));
825 DIArray Subprograms = TheCU.getSubprograms();
826 for (unsigned i = 0, e = Subprograms.getNumElements(); i != e; ++i) {
827 DISubprogram SP(Subprograms.getElement(i));
828 // Perhaps the subprogram is in another CU (such as due to comdat
829 // folding, etc), in which case ignore it here.
830 if (SPMap[SP] != SPCU)
832 DIE *D = SPCU->getDIE(SP);
833 if (DIE *AbsSPDIE = AbstractSPDies.lookup(SP)) {
835 // If this subprogram has an abstract definition, reference that
836 SPCU->addDIEEntry(*D, dwarf::DW_AT_abstract_origin, *AbsSPDIE);
839 // Lazily construct the subprogram if we didn't see either concrete or
840 // inlined versions during codegen.
841 D = SPCU->getOrCreateSubprogramDIE(SP);
842 // And attach the attributes
843 SPCU->applySubprogramAttributesToDefinition(SP, *D);
850 // Collect info for variables that were optimized out.
851 void DwarfDebug::collectDeadVariables() {
852 const Module *M = MMI->getModule();
854 if (NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu")) {
855 for (MDNode *N : CU_Nodes->operands()) {
856 DICompileUnit TheCU(N);
857 // Construct subprogram DIE and add variables DIEs.
858 DwarfCompileUnit *SPCU =
859 static_cast<DwarfCompileUnit *>(CUMap.lookup(TheCU));
860 assert(SPCU && "Unable to find Compile Unit!");
861 DIArray Subprograms = TheCU.getSubprograms();
862 for (unsigned i = 0, e = Subprograms.getNumElements(); i != e; ++i) {
863 DISubprogram SP(Subprograms.getElement(i));
864 if (ProcessedSPNodes.count(SP) != 0)
866 assert(SP.isSubprogram() &&
867 "CU's subprogram list contains a non-subprogram");
868 assert(SP.isDefinition() &&
869 "CU's subprogram list contains a subprogram declaration");
870 DIArray Variables = SP.getVariables();
871 if (Variables.getNumElements() == 0)
874 DIE *SPDIE = AbstractSPDies.lookup(SP);
876 SPDIE = SPCU->getDIE(SP);
878 for (unsigned vi = 0, ve = Variables.getNumElements(); vi != ve; ++vi) {
879 DIVariable DV(Variables.getElement(vi));
880 assert(DV.isVariable());
881 DbgVariable NewVar(DV, this);
882 auto VariableDie = SPCU->constructVariableDIE(NewVar);
883 SPCU->applyVariableAttributes(NewVar, *VariableDie);
884 SPDIE->addChild(std::move(VariableDie));
891 void DwarfDebug::finalizeModuleInfo() {
892 finishSubprogramDefinitions();
894 finishVariableDefinitions();
896 // Collect info for variables that were optimized out.
897 collectDeadVariables();
899 // Handle anything that needs to be done on a per-unit basis after
900 // all other generation.
901 for (const auto &TheU : getUnits()) {
902 // Emit DW_AT_containing_type attribute to connect types with their
903 // vtable holding type.
904 TheU->constructContainingTypeDIEs();
906 // Add CU specific attributes if we need to add any.
907 if (TheU->getUnitDie().getTag() == dwarf::DW_TAG_compile_unit) {
908 // If we're splitting the dwarf out now that we've got the entire
909 // CU then add the dwo id to it.
910 DwarfCompileUnit *SkCU =
911 static_cast<DwarfCompileUnit *>(TheU->getSkeleton());
912 if (useSplitDwarf()) {
913 // Emit a unique identifier for this CU.
914 uint64_t ID = DIEHash(Asm).computeCUSignature(TheU->getUnitDie());
915 TheU->addUInt(TheU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
916 dwarf::DW_FORM_data8, ID);
917 SkCU->addUInt(SkCU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
918 dwarf::DW_FORM_data8, ID);
920 // We don't keep track of which addresses are used in which CU so this
921 // is a bit pessimistic under LTO.
922 if (!AddrPool.isEmpty())
923 addSectionLabel(*Asm, *SkCU, SkCU->getUnitDie(),
924 dwarf::DW_AT_GNU_addr_base, DwarfAddrSectionSym,
925 DwarfAddrSectionSym);
926 if (!TheU->getRangeLists().empty())
927 addSectionLabel(*Asm, *SkCU, SkCU->getUnitDie(),
928 dwarf::DW_AT_GNU_ranges_base,
929 DwarfDebugRangeSectionSym, DwarfDebugRangeSectionSym);
932 // If we have code split among multiple sections or non-contiguous
933 // ranges of code then emit a DW_AT_ranges attribute on the unit that will
934 // remain in the .o file, otherwise add a DW_AT_low_pc.
935 // FIXME: We should use ranges allow reordering of code ala
936 // .subsections_via_symbols in mach-o. This would mean turning on
937 // ranges for all subprogram DIEs for mach-o.
938 DwarfCompileUnit &U =
939 SkCU ? *SkCU : static_cast<DwarfCompileUnit &>(*TheU);
940 unsigned NumRanges = TheU->getRanges().size();
943 addSectionLabel(*Asm, U, U.getUnitDie(), dwarf::DW_AT_ranges,
944 Asm->GetTempSymbol("cu_ranges", U.getUniqueID()),
945 DwarfDebugRangeSectionSym);
947 // A DW_AT_low_pc attribute may also be specified in combination with
948 // DW_AT_ranges to specify the default base address for use in
949 // location lists (see Section 2.6.2) and range lists (see Section
951 U.addUInt(U.getUnitDie(), dwarf::DW_AT_low_pc, dwarf::DW_FORM_addr,
954 RangeSpan &Range = TheU->getRanges().back();
955 U.addLocalLabelAddress(U.getUnitDie(), dwarf::DW_AT_low_pc,
957 U.addLabelDelta(U.getUnitDie(), dwarf::DW_AT_high_pc, Range.getEnd(),
964 // Compute DIE offsets and sizes.
965 InfoHolder.computeSizeAndOffsets();
967 SkeletonHolder.computeSizeAndOffsets();
970 void DwarfDebug::endSections() {
971 // Filter labels by section.
972 for (const SymbolCU &SCU : ArangeLabels) {
973 if (SCU.Sym->isInSection()) {
974 // Make a note of this symbol and it's section.
975 const MCSection *Section = &SCU.Sym->getSection();
976 if (!Section->getKind().isMetadata())
977 SectionMap[Section].push_back(SCU);
979 // Some symbols (e.g. common/bss on mach-o) can have no section but still
980 // appear in the output. This sucks as we rely on sections to build
981 // arange spans. We can do it without, but it's icky.
982 SectionMap[nullptr].push_back(SCU);
986 // Build a list of sections used.
987 std::vector<const MCSection *> Sections;
988 for (const auto &it : SectionMap) {
989 const MCSection *Section = it.first;
990 Sections.push_back(Section);
993 // Sort the sections into order.
994 // This is only done to ensure consistent output order across different runs.
995 std::sort(Sections.begin(), Sections.end(), SectionSort);
997 // Add terminating symbols for each section.
998 for (unsigned ID = 0, E = Sections.size(); ID != E; ID++) {
999 const MCSection *Section = Sections[ID];
1000 MCSymbol *Sym = nullptr;
1003 // We can't call MCSection::getLabelEndName, as it's only safe to do so
1004 // if we know the section name up-front. For user-created sections, the
1005 // resulting label may not be valid to use as a label. (section names can
1006 // use a greater set of characters on some systems)
1007 Sym = Asm->GetTempSymbol("debug_end", ID);
1008 Asm->OutStreamer.SwitchSection(Section);
1009 Asm->OutStreamer.EmitLabel(Sym);
1012 // Insert a final terminator.
1013 SectionMap[Section].push_back(SymbolCU(nullptr, Sym));
1017 // Emit all Dwarf sections that should come after the content.
1018 void DwarfDebug::endModule() {
1019 assert(CurFn == nullptr);
1020 assert(CurMI == nullptr);
1025 // End any existing sections.
1026 // TODO: Does this need to happen?
1029 // Finalize the debug info for the module.
1030 finalizeModuleInfo();
1034 // Emit all the DIEs into a debug info section.
1037 // Corresponding abbreviations into a abbrev section.
1038 emitAbbreviations();
1040 // Emit info into a debug aranges section.
1041 if (GenerateARangeSection)
1044 // Emit info into a debug ranges section.
1047 if (useSplitDwarf()) {
1050 emitDebugAbbrevDWO();
1053 // Emit DWO addresses.
1054 AddrPool.emit(*Asm, Asm->getObjFileLowering().getDwarfAddrSection());
1056 // Emit info into a debug loc section.
1059 // Emit info into the dwarf accelerator table sections.
1060 if (useDwarfAccelTables()) {
1063 emitAccelNamespaces();
1067 // Emit the pubnames and pubtypes sections if requested.
1068 if (HasDwarfPubSections) {
1069 emitDebugPubNames(GenerateGnuPubSections);
1070 emitDebugPubTypes(GenerateGnuPubSections);
1075 AbstractVariables.clear();
1077 // Reset these for the next Module if we have one.
1081 // Find abstract variable, if any, associated with Var.
1082 DbgVariable *DwarfDebug::getExistingAbstractVariable(const DIVariable &DV,
1083 DIVariable &Cleansed) {
1084 LLVMContext &Ctx = DV->getContext();
1085 // More then one inlined variable corresponds to one abstract variable.
1086 // FIXME: This duplication of variables when inlining should probably be
1087 // removed. It's done to allow each DIVariable to describe its location
1088 // because the DebugLoc on the dbg.value/declare isn't accurate. We should
1089 // make it accurate then remove this duplication/cleansing stuff.
1090 Cleansed = cleanseInlinedVariable(DV, Ctx);
1091 auto I = AbstractVariables.find(Cleansed);
1092 if (I != AbstractVariables.end())
1093 return I->second.get();
1097 DbgVariable *DwarfDebug::getExistingAbstractVariable(const DIVariable &DV) {
1098 DIVariable Cleansed;
1099 return getExistingAbstractVariable(DV, Cleansed);
1102 void DwarfDebug::createAbstractVariable(const DIVariable &Var,
1103 LexicalScope *Scope) {
1104 auto AbsDbgVariable = make_unique<DbgVariable>(Var, this);
1105 addScopeVariable(Scope, AbsDbgVariable.get());
1106 AbstractVariables[Var] = std::move(AbsDbgVariable);
1109 void DwarfDebug::ensureAbstractVariableIsCreated(const DIVariable &DV,
1110 const MDNode *ScopeNode) {
1111 DIVariable Cleansed = DV;
1112 if (getExistingAbstractVariable(DV, Cleansed))
1115 createAbstractVariable(Cleansed, LScopes.getOrCreateAbstractScope(ScopeNode));
1119 DwarfDebug::ensureAbstractVariableIsCreatedIfScoped(const DIVariable &DV,
1120 const MDNode *ScopeNode) {
1121 DIVariable Cleansed = DV;
1122 if (getExistingAbstractVariable(DV, Cleansed))
1125 if (LexicalScope *Scope = LScopes.findAbstractScope(ScopeNode))
1126 createAbstractVariable(Cleansed, Scope);
1129 // If Var is a current function argument then add it to CurrentFnArguments list.
1130 bool DwarfDebug::addCurrentFnArgument(DbgVariable *Var, LexicalScope *Scope) {
1131 if (!LScopes.isCurrentFunctionScope(Scope))
1133 DIVariable DV = Var->getVariable();
1134 if (DV.getTag() != dwarf::DW_TAG_arg_variable)
1136 unsigned ArgNo = DV.getArgNumber();
1140 size_t Size = CurrentFnArguments.size();
1142 CurrentFnArguments.resize(CurFn->getFunction()->arg_size());
1143 // llvm::Function argument size is not good indicator of how many
1144 // arguments does the function have at source level.
1146 CurrentFnArguments.resize(ArgNo * 2);
1147 assert(!CurrentFnArguments[ArgNo - 1]);
1148 CurrentFnArguments[ArgNo - 1] = Var;
1152 // Collect variable information from side table maintained by MMI.
1153 void DwarfDebug::collectVariableInfoFromMMITable(
1154 SmallPtrSet<const MDNode *, 16> &Processed) {
1155 for (const auto &VI : MMI->getVariableDbgInfo()) {
1158 Processed.insert(VI.Var);
1159 DIVariable DV(VI.Var);
1160 LexicalScope *Scope = LScopes.findLexicalScope(VI.Loc);
1162 // If variable scope is not found then skip this variable.
1166 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
1167 ConcreteVariables.push_back(make_unique<DbgVariable>(DV, this));
1168 DbgVariable *RegVar = ConcreteVariables.back().get();
1169 RegVar->setFrameIndex(VI.Slot);
1170 addScopeVariable(Scope, RegVar);
1174 // Get .debug_loc entry for the instruction range starting at MI.
1175 static DebugLocEntry::Value getDebugLocValue(const MachineInstr *MI) {
1176 const MDNode *Var = MI->getDebugVariable();
1178 assert(MI->getNumOperands() == 3);
1179 if (MI->getOperand(0).isReg()) {
1180 MachineLocation MLoc;
1181 // If the second operand is an immediate, this is a
1182 // register-indirect address.
1183 if (!MI->getOperand(1).isImm())
1184 MLoc.set(MI->getOperand(0).getReg());
1186 MLoc.set(MI->getOperand(0).getReg(), MI->getOperand(1).getImm());
1187 return DebugLocEntry::Value(Var, MLoc);
1189 if (MI->getOperand(0).isImm())
1190 return DebugLocEntry::Value(Var, MI->getOperand(0).getImm());
1191 if (MI->getOperand(0).isFPImm())
1192 return DebugLocEntry::Value(Var, MI->getOperand(0).getFPImm());
1193 if (MI->getOperand(0).isCImm())
1194 return DebugLocEntry::Value(Var, MI->getOperand(0).getCImm());
1196 llvm_unreachable("Unexpected 3 operand DBG_VALUE instruction!");
1199 /// Determine whether two variable pieces overlap.
1200 static bool piecesOverlap(DIVariable P1, DIVariable P2) {
1201 if (!P1.isVariablePiece() || !P2.isVariablePiece())
1203 unsigned l1 = P1.getPieceOffset();
1204 unsigned l2 = P2.getPieceOffset();
1205 unsigned r1 = l1 + P1.getPieceSize();
1206 unsigned r2 = l2 + P2.getPieceSize();
1207 // True where [l1,r1[ and [r1,r2[ overlap.
1208 return (l1 < r2) && (l2 < r1);
1211 /// Build the location list for all DBG_VALUEs in the function that
1212 /// describe the same variable. If the ranges of several independent
1213 /// pieces of the same variable overlap partially, split them up and
1214 /// combine the ranges. The resulting DebugLocEntries are will have
1215 /// strict monotonically increasing begin addresses and will never
1220 // Ranges History [var, loc, piece ofs size]
1221 // 0 | [x, (reg0, piece 0, 32)]
1222 // 1 | | [x, (reg1, piece 32, 32)] <- IsPieceOfPrevEntry
1224 // 3 | [clobber reg0]
1225 // 4 [x, (mem, piece 0, 64)] <- overlapping with both previous pieces of x.
1229 // [0-1] [x, (reg0, piece 0, 32)]
1230 // [1-3] [x, (reg0, piece 0, 32), (reg1, piece 32, 32)]
1231 // [3-4] [x, (reg1, piece 32, 32)]
1232 // [4- ] [x, (mem, piece 0, 64)]
1234 DwarfDebug::buildLocationList(SmallVectorImpl<DebugLocEntry> &DebugLoc,
1235 const DbgValueHistoryMap::InstrRanges &Ranges) {
1236 typedef std::pair<DIVariable, DebugLocEntry::Value> Range;
1237 SmallVector<Range, 4> OpenRanges;
1239 for (auto I = Ranges.begin(), E = Ranges.end(); I != E; ++I) {
1240 const MachineInstr *Begin = I->first;
1241 const MachineInstr *End = I->second;
1242 assert(Begin->isDebugValue() && "Invalid History entry");
1244 // Check if a variable is inaccessible in this range.
1245 if (!Begin->isDebugValue() ||
1246 (Begin->getNumOperands() > 1 && Begin->getOperand(0).isReg() &&
1247 !Begin->getOperand(0).getReg())) {
1252 // If this piece overlaps with any open ranges, truncate them.
1253 DIVariable DIVar = Begin->getDebugVariable();
1254 auto Last = std::remove_if(OpenRanges.begin(), OpenRanges.end(), [&](Range R){
1255 return piecesOverlap(DIVar, R.first);
1257 OpenRanges.erase(Last, OpenRanges.end());
1259 const MCSymbol *StartLabel = getLabelBeforeInsn(Begin);
1260 assert(StartLabel && "Forgot label before DBG_VALUE starting a range!");
1262 const MCSymbol *EndLabel;
1264 EndLabel = getLabelAfterInsn(End);
1265 else if (std::next(I) == Ranges.end())
1266 EndLabel = FunctionEndSym;
1268 EndLabel = getLabelBeforeInsn(std::next(I)->first);
1269 assert(EndLabel && "Forgot label after instruction ending a range!");
1271 DEBUG(dbgs() << "DotDebugLoc: " << *Begin << "\n");
1273 auto Value = getDebugLocValue(Begin);
1274 DebugLocEntry Loc(StartLabel, EndLabel, Value);
1275 if (DebugLoc.empty() || !DebugLoc.back().Merge(Loc)) {
1276 // Add all values from still valid non-overlapping pieces.
1277 for (auto Range : OpenRanges)
1278 Loc.addValue(Range.second);
1279 DebugLoc.push_back(std::move(Loc));
1281 // Add this value to the list of open ranges.
1282 if (DIVar.isVariablePiece())
1283 OpenRanges.push_back(std::make_pair(DIVar, Value));
1285 DEBUG(dbgs() << "Values:\n";
1286 for (auto Value : DebugLoc.back().getValues())
1287 Value.getVariable()->dump();
1288 dbgs() << "-----\n");
1293 // Find variables for each lexical scope.
1295 DwarfDebug::collectVariableInfo(SmallPtrSet<const MDNode *, 16> &Processed) {
1296 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1297 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1299 // Grab the variable info that was squirreled away in the MMI side-table.
1300 collectVariableInfoFromMMITable(Processed);
1302 for (const auto &I : DbgValues) {
1303 DIVariable DV(I.first);
1304 if (Processed.count(DV))
1307 // Instruction ranges, specifying where DV is accessible.
1308 const auto &Ranges = I.second;
1312 LexicalScope *Scope = nullptr;
1313 if (MDNode *IA = DV.getInlinedAt()) {
1314 DebugLoc DL = DebugLoc::getFromDILocation(IA);
1315 Scope = LScopes.findInlinedScope(DebugLoc::get(
1316 DL.getLine(), DL.getCol(), DV.getContext(), IA));
1318 Scope = LScopes.findLexicalScope(DV.getContext());
1319 // If variable scope is not found then skip this variable.
1323 Processed.insert(getEntireVariable(DV));
1324 const MachineInstr *MInsn = Ranges.front().first;
1325 assert(MInsn->isDebugValue() && "History must begin with debug value");
1326 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
1327 ConcreteVariables.push_back(make_unique<DbgVariable>(MInsn, this));
1328 DbgVariable *RegVar = ConcreteVariables.back().get();
1329 addScopeVariable(Scope, RegVar);
1331 // Check if the first DBG_VALUE is valid for the rest of the function.
1332 if (Ranges.size() == 1 && Ranges.front().second == nullptr)
1335 // Handle multiple DBG_VALUE instructions describing one variable.
1336 RegVar->setDotDebugLocOffset(DotDebugLocEntries.size());
1338 DotDebugLocEntries.resize(DotDebugLocEntries.size() + 1);
1339 DebugLocList &LocList = DotDebugLocEntries.back();
1342 Asm->GetTempSymbol("debug_loc", DotDebugLocEntries.size() - 1);
1344 // Build the location list for this variable.
1345 buildLocationList(LocList.List, Ranges);
1348 // Collect info for variables that were optimized out.
1349 DIArray Variables = DISubprogram(FnScope->getScopeNode()).getVariables();
1350 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1351 DIVariable DV(Variables.getElement(i));
1352 assert(DV.isVariable());
1353 if (!Processed.insert(DV))
1355 if (LexicalScope *Scope = LScopes.findLexicalScope(DV.getContext())) {
1356 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
1357 ConcreteVariables.push_back(make_unique<DbgVariable>(DV, this));
1358 addScopeVariable(Scope, ConcreteVariables.back().get());
1363 // Return Label preceding the instruction.
1364 MCSymbol *DwarfDebug::getLabelBeforeInsn(const MachineInstr *MI) {
1365 MCSymbol *Label = LabelsBeforeInsn.lookup(MI);
1366 assert(Label && "Didn't insert label before instruction");
1370 // Return Label immediately following the instruction.
1371 MCSymbol *DwarfDebug::getLabelAfterInsn(const MachineInstr *MI) {
1372 return LabelsAfterInsn.lookup(MI);
1375 // Process beginning of an instruction.
1376 void DwarfDebug::beginInstruction(const MachineInstr *MI) {
1377 assert(CurMI == nullptr);
1379 // Check if source location changes, but ignore DBG_VALUE locations.
1380 if (!MI->isDebugValue()) {
1381 DebugLoc DL = MI->getDebugLoc();
1382 if (DL != PrevInstLoc && (!DL.isUnknown() || UnknownLocations)) {
1385 if (DL == PrologEndLoc) {
1386 Flags |= DWARF2_FLAG_PROLOGUE_END;
1387 PrologEndLoc = DebugLoc();
1389 if (PrologEndLoc.isUnknown())
1390 Flags |= DWARF2_FLAG_IS_STMT;
1392 if (!DL.isUnknown()) {
1393 const MDNode *Scope = DL.getScope(Asm->MF->getFunction()->getContext());
1394 recordSourceLine(DL.getLine(), DL.getCol(), Scope, Flags);
1396 recordSourceLine(0, 0, nullptr, 0);
1400 // Insert labels where requested.
1401 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1402 LabelsBeforeInsn.find(MI);
1405 if (I == LabelsBeforeInsn.end())
1408 // Label already assigned.
1413 PrevLabel = MMI->getContext().CreateTempSymbol();
1414 Asm->OutStreamer.EmitLabel(PrevLabel);
1416 I->second = PrevLabel;
1419 // Process end of an instruction.
1420 void DwarfDebug::endInstruction() {
1421 assert(CurMI != nullptr);
1422 // Don't create a new label after DBG_VALUE instructions.
1423 // They don't generate code.
1424 if (!CurMI->isDebugValue())
1425 PrevLabel = nullptr;
1427 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1428 LabelsAfterInsn.find(CurMI);
1432 if (I == LabelsAfterInsn.end())
1435 // Label already assigned.
1439 // We need a label after this instruction.
1441 PrevLabel = MMI->getContext().CreateTempSymbol();
1442 Asm->OutStreamer.EmitLabel(PrevLabel);
1444 I->second = PrevLabel;
1447 // Each LexicalScope has first instruction and last instruction to mark
1448 // beginning and end of a scope respectively. Create an inverse map that list
1449 // scopes starts (and ends) with an instruction. One instruction may start (or
1450 // end) multiple scopes. Ignore scopes that are not reachable.
1451 void DwarfDebug::identifyScopeMarkers() {
1452 SmallVector<LexicalScope *, 4> WorkList;
1453 WorkList.push_back(LScopes.getCurrentFunctionScope());
1454 while (!WorkList.empty()) {
1455 LexicalScope *S = WorkList.pop_back_val();
1457 const SmallVectorImpl<LexicalScope *> &Children = S->getChildren();
1458 if (!Children.empty())
1459 WorkList.append(Children.begin(), Children.end());
1461 if (S->isAbstractScope())
1464 for (const InsnRange &R : S->getRanges()) {
1465 assert(R.first && "InsnRange does not have first instruction!");
1466 assert(R.second && "InsnRange does not have second instruction!");
1467 requestLabelBeforeInsn(R.first);
1468 requestLabelAfterInsn(R.second);
1473 static DebugLoc findPrologueEndLoc(const MachineFunction *MF) {
1474 // First known non-DBG_VALUE and non-frame setup location marks
1475 // the beginning of the function body.
1476 for (const auto &MBB : *MF)
1477 for (const auto &MI : MBB)
1478 if (!MI.isDebugValue() && !MI.getFlag(MachineInstr::FrameSetup) &&
1479 !MI.getDebugLoc().isUnknown())
1480 return MI.getDebugLoc();
1484 // Gather pre-function debug information. Assumes being called immediately
1485 // after the function entry point has been emitted.
1486 void DwarfDebug::beginFunction(const MachineFunction *MF) {
1489 // If there's no debug info for the function we're not going to do anything.
1490 if (!MMI->hasDebugInfo())
1493 auto DI = FunctionDIs.find(MF->getFunction());
1494 if (DI == FunctionDIs.end())
1497 // Grab the lexical scopes for the function, if we don't have any of those
1498 // then we're not going to be able to do anything.
1499 LScopes.initialize(*MF);
1500 if (LScopes.empty())
1503 assert(DbgValues.empty() && "DbgValues map wasn't cleaned!");
1505 // Make sure that each lexical scope will have a begin/end label.
1506 identifyScopeMarkers();
1508 // Set DwarfDwarfCompileUnitID in MCContext to the Compile Unit this function
1509 // belongs to so that we add to the correct per-cu line table in the
1511 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1512 // FnScope->getScopeNode() and DI->second should represent the same function,
1513 // though they may not be the same MDNode due to inline functions merged in
1514 // LTO where the debug info metadata still differs (either due to distinct
1515 // written differences - two versions of a linkonce_odr function
1516 // written/copied into two separate files, or some sub-optimal metadata that
1517 // isn't structurally identical (see: file path/name info from clang, which
1518 // includes the directory of the cpp file being built, even when the file name
1519 // is absolute (such as an <> lookup header)))
1520 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1521 assert(TheCU && "Unable to find compile unit!");
1522 if (Asm->OutStreamer.hasRawTextSupport())
1523 // Use a single line table if we are generating assembly.
1524 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1526 Asm->OutStreamer.getContext().setDwarfCompileUnitID(TheCU->getUniqueID());
1528 // Emit a label for the function so that we have a beginning address.
1529 FunctionBeginSym = Asm->GetTempSymbol("func_begin", Asm->getFunctionNumber());
1530 // Assumes in correct section after the entry point.
1531 Asm->OutStreamer.EmitLabel(FunctionBeginSym);
1533 // Calculate history for local variables.
1534 calculateDbgValueHistory(MF, Asm->TM.getSubtargetImpl()->getRegisterInfo(),
1537 // Request labels for the full history.
1538 for (const auto &I : DbgValues) {
1539 const auto &Ranges = I.second;
1543 // The first mention of a function argument gets the FunctionBeginSym
1544 // label, so arguments are visible when breaking at function entry.
1545 DIVariable DV(Ranges.front().first->getDebugVariable());
1546 if (DV.isVariable() && DV.getTag() == dwarf::DW_TAG_arg_variable &&
1547 getDISubprogram(DV.getContext()).describes(MF->getFunction())) {
1548 if (!DV.isVariablePiece())
1549 LabelsBeforeInsn[Ranges.front().first] = FunctionBeginSym;
1551 // Mark all non-overlapping initial pieces.
1552 for (auto I = Ranges.begin(); I != Ranges.end(); ++I) {
1553 DIVariable Piece = I->first->getDebugVariable();
1554 if (std::all_of(Ranges.begin(), I,
1555 [&](DbgValueHistoryMap::InstrRange Pred){
1556 return !piecesOverlap(Piece, Pred.first->getDebugVariable());
1558 LabelsBeforeInsn[I->first] = FunctionBeginSym;
1565 for (const auto &Range : Ranges) {
1566 requestLabelBeforeInsn(Range.first);
1568 requestLabelAfterInsn(Range.second);
1572 PrevInstLoc = DebugLoc();
1573 PrevLabel = FunctionBeginSym;
1575 // Record beginning of function.
1576 PrologEndLoc = findPrologueEndLoc(MF);
1577 if (!PrologEndLoc.isUnknown()) {
1578 DebugLoc FnStartDL =
1579 PrologEndLoc.getFnDebugLoc(MF->getFunction()->getContext());
1581 FnStartDL.getLine(), FnStartDL.getCol(),
1582 FnStartDL.getScope(MF->getFunction()->getContext()),
1583 // We'd like to list the prologue as "not statements" but GDB behaves
1584 // poorly if we do that. Revisit this with caution/GDB (7.5+) testing.
1585 DWARF2_FLAG_IS_STMT);
1589 void DwarfDebug::addScopeVariable(LexicalScope *LS, DbgVariable *Var) {
1590 if (addCurrentFnArgument(Var, LS))
1592 SmallVectorImpl<DbgVariable *> &Vars = ScopeVariables[LS];
1593 DIVariable DV = Var->getVariable();
1594 // Variables with positive arg numbers are parameters.
1595 if (unsigned ArgNum = DV.getArgNumber()) {
1596 // Keep all parameters in order at the start of the variable list to ensure
1597 // function types are correct (no out-of-order parameters)
1599 // This could be improved by only doing it for optimized builds (unoptimized
1600 // builds have the right order to begin with), searching from the back (this
1601 // would catch the unoptimized case quickly), or doing a binary search
1602 // rather than linear search.
1603 SmallVectorImpl<DbgVariable *>::iterator I = Vars.begin();
1604 while (I != Vars.end()) {
1605 unsigned CurNum = (*I)->getVariable().getArgNumber();
1606 // A local (non-parameter) variable has been found, insert immediately
1610 // A later indexed parameter has been found, insert immediately before it.
1611 if (CurNum > ArgNum)
1615 Vars.insert(I, Var);
1619 Vars.push_back(Var);
1622 // Gather and emit post-function debug information.
1623 void DwarfDebug::endFunction(const MachineFunction *MF) {
1624 // Every beginFunction(MF) call should be followed by an endFunction(MF) call,
1625 // though the beginFunction may not be called at all.
1626 // We should handle both cases.
1630 assert(CurFn == MF);
1631 assert(CurFn != nullptr);
1633 if (!MMI->hasDebugInfo() || LScopes.empty() ||
1634 !FunctionDIs.count(MF->getFunction())) {
1635 // If we don't have a lexical scope for this function then there will
1636 // be a hole in the range information. Keep note of this by setting the
1637 // previously used section to nullptr.
1638 PrevSection = nullptr;
1644 // Define end label for subprogram.
1645 FunctionEndSym = Asm->GetTempSymbol("func_end", Asm->getFunctionNumber());
1646 // Assumes in correct section after the entry point.
1647 Asm->OutStreamer.EmitLabel(FunctionEndSym);
1649 // Set DwarfDwarfCompileUnitID in MCContext to default value.
1650 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1652 SmallPtrSet<const MDNode *, 16> ProcessedVars;
1653 collectVariableInfo(ProcessedVars);
1655 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1656 DwarfCompileUnit &TheCU = *SPMap.lookup(FnScope->getScopeNode());
1658 // Construct abstract scopes.
1659 for (LexicalScope *AScope : LScopes.getAbstractScopesList()) {
1660 DISubprogram SP(AScope->getScopeNode());
1661 assert(SP.isSubprogram());
1662 // Collect info for variables that were optimized out.
1663 DIArray Variables = SP.getVariables();
1664 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1665 DIVariable DV(Variables.getElement(i));
1666 assert(DV && DV.isVariable());
1667 if (!ProcessedVars.insert(DV))
1669 ensureAbstractVariableIsCreated(DV, DV.getContext());
1671 constructAbstractSubprogramScopeDIE(TheCU, AScope);
1674 DIE &CurFnDIE = constructSubprogramScopeDIE(TheCU, FnScope);
1675 if (!CurFn->getTarget().Options.DisableFramePointerElim(*CurFn))
1676 TheCU.addFlag(CurFnDIE, dwarf::DW_AT_APPLE_omit_frame_ptr);
1678 // Add the range of this function to the list of ranges for the CU.
1679 RangeSpan Span(FunctionBeginSym, FunctionEndSym);
1680 TheCU.addRange(std::move(Span));
1681 PrevSection = Asm->getCurrentSection();
1685 // Ownership of DbgVariables is a bit subtle - ScopeVariables owns all the
1686 // DbgVariables except those that are also in AbstractVariables (since they
1687 // can be used cross-function)
1688 ScopeVariables.clear();
1689 CurrentFnArguments.clear();
1691 LabelsBeforeInsn.clear();
1692 LabelsAfterInsn.clear();
1693 PrevLabel = nullptr;
1697 // Register a source line with debug info. Returns the unique label that was
1698 // emitted and which provides correspondence to the source line list.
1699 void DwarfDebug::recordSourceLine(unsigned Line, unsigned Col, const MDNode *S,
1704 unsigned Discriminator = 0;
1705 if (DIScope Scope = DIScope(S)) {
1706 assert(Scope.isScope());
1707 Fn = Scope.getFilename();
1708 Dir = Scope.getDirectory();
1709 if (Scope.isLexicalBlock())
1710 Discriminator = DILexicalBlock(S).getDiscriminator();
1712 unsigned CUID = Asm->OutStreamer.getContext().getDwarfCompileUnitID();
1713 Src = static_cast<DwarfCompileUnit &>(*InfoHolder.getUnits()[CUID])
1714 .getOrCreateSourceID(Fn, Dir);
1716 Asm->OutStreamer.EmitDwarfLocDirective(Src, Line, Col, Flags, 0,
1720 //===----------------------------------------------------------------------===//
1722 //===----------------------------------------------------------------------===//
1724 // Emit initial Dwarf sections with a label at the start of each one.
1725 void DwarfDebug::emitSectionLabels() {
1726 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
1728 // Dwarf sections base addresses.
1729 DwarfInfoSectionSym =
1730 emitSectionSym(Asm, TLOF.getDwarfInfoSection(), "section_info");
1731 if (useSplitDwarf()) {
1732 DwarfInfoDWOSectionSym =
1733 emitSectionSym(Asm, TLOF.getDwarfInfoDWOSection(), "section_info_dwo");
1734 DwarfTypesDWOSectionSym =
1735 emitSectionSym(Asm, TLOF.getDwarfTypesDWOSection(), "section_types_dwo");
1737 DwarfAbbrevSectionSym =
1738 emitSectionSym(Asm, TLOF.getDwarfAbbrevSection(), "section_abbrev");
1739 if (useSplitDwarf())
1740 DwarfAbbrevDWOSectionSym = emitSectionSym(
1741 Asm, TLOF.getDwarfAbbrevDWOSection(), "section_abbrev_dwo");
1742 if (GenerateARangeSection)
1743 emitSectionSym(Asm, TLOF.getDwarfARangesSection());
1745 DwarfLineSectionSym =
1746 emitSectionSym(Asm, TLOF.getDwarfLineSection(), "section_line");
1747 if (GenerateGnuPubSections) {
1748 DwarfGnuPubNamesSectionSym =
1749 emitSectionSym(Asm, TLOF.getDwarfGnuPubNamesSection());
1750 DwarfGnuPubTypesSectionSym =
1751 emitSectionSym(Asm, TLOF.getDwarfGnuPubTypesSection());
1752 } else if (HasDwarfPubSections) {
1753 emitSectionSym(Asm, TLOF.getDwarfPubNamesSection());
1754 emitSectionSym(Asm, TLOF.getDwarfPubTypesSection());
1757 DwarfStrSectionSym =
1758 emitSectionSym(Asm, TLOF.getDwarfStrSection(), "info_string");
1759 if (useSplitDwarf()) {
1760 DwarfStrDWOSectionSym =
1761 emitSectionSym(Asm, TLOF.getDwarfStrDWOSection(), "skel_string");
1762 DwarfAddrSectionSym =
1763 emitSectionSym(Asm, TLOF.getDwarfAddrSection(), "addr_sec");
1764 DwarfDebugLocSectionSym =
1765 emitSectionSym(Asm, TLOF.getDwarfLocDWOSection(), "skel_loc");
1767 DwarfDebugLocSectionSym =
1768 emitSectionSym(Asm, TLOF.getDwarfLocSection(), "section_debug_loc");
1769 DwarfDebugRangeSectionSym =
1770 emitSectionSym(Asm, TLOF.getDwarfRangesSection(), "debug_range");
1773 // Recursively emits a debug information entry.
1774 void DwarfDebug::emitDIE(DIE &Die) {
1775 // Get the abbreviation for this DIE.
1776 const DIEAbbrev &Abbrev = Die.getAbbrev();
1778 // Emit the code (index) for the abbreviation.
1779 if (Asm->isVerbose())
1780 Asm->OutStreamer.AddComment("Abbrev [" + Twine(Abbrev.getNumber()) +
1781 "] 0x" + Twine::utohexstr(Die.getOffset()) +
1782 ":0x" + Twine::utohexstr(Die.getSize()) + " " +
1783 dwarf::TagString(Abbrev.getTag()));
1784 Asm->EmitULEB128(Abbrev.getNumber());
1786 const SmallVectorImpl<DIEValue *> &Values = Die.getValues();
1787 const SmallVectorImpl<DIEAbbrevData> &AbbrevData = Abbrev.getData();
1789 // Emit the DIE attribute values.
1790 for (unsigned i = 0, N = Values.size(); i < N; ++i) {
1791 dwarf::Attribute Attr = AbbrevData[i].getAttribute();
1792 dwarf::Form Form = AbbrevData[i].getForm();
1793 assert(Form && "Too many attributes for DIE (check abbreviation)");
1795 if (Asm->isVerbose()) {
1796 Asm->OutStreamer.AddComment(dwarf::AttributeString(Attr));
1797 if (Attr == dwarf::DW_AT_accessibility)
1798 Asm->OutStreamer.AddComment(dwarf::AccessibilityString(
1799 cast<DIEInteger>(Values[i])->getValue()));
1802 // Emit an attribute using the defined form.
1803 Values[i]->EmitValue(Asm, Form);
1806 // Emit the DIE children if any.
1807 if (Abbrev.hasChildren()) {
1808 for (auto &Child : Die.getChildren())
1811 Asm->OutStreamer.AddComment("End Of Children Mark");
1816 // Emit the debug info section.
1817 void DwarfDebug::emitDebugInfo() {
1818 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1820 Holder.emitUnits(this, DwarfAbbrevSectionSym);
1823 // Emit the abbreviation section.
1824 void DwarfDebug::emitAbbreviations() {
1825 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1827 Holder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevSection());
1830 // Emit the last address of the section and the end of the line matrix.
1831 void DwarfDebug::emitEndOfLineMatrix(unsigned SectionEnd) {
1832 // Define last address of section.
1833 Asm->OutStreamer.AddComment("Extended Op");
1836 Asm->OutStreamer.AddComment("Op size");
1837 Asm->EmitInt8(Asm->getDataLayout().getPointerSize() + 1);
1838 Asm->OutStreamer.AddComment("DW_LNE_set_address");
1839 Asm->EmitInt8(dwarf::DW_LNE_set_address);
1841 Asm->OutStreamer.AddComment("Section end label");
1843 Asm->OutStreamer.EmitSymbolValue(
1844 Asm->GetTempSymbol("section_end", SectionEnd),
1845 Asm->getDataLayout().getPointerSize());
1847 // Mark end of matrix.
1848 Asm->OutStreamer.AddComment("DW_LNE_end_sequence");
1854 // Emit visible names into a hashed accelerator table section.
1855 void DwarfDebug::emitAccelNames() {
1856 AccelNames.FinalizeTable(Asm, "Names");
1857 Asm->OutStreamer.SwitchSection(
1858 Asm->getObjFileLowering().getDwarfAccelNamesSection());
1859 MCSymbol *SectionBegin = Asm->GetTempSymbol("names_begin");
1860 Asm->OutStreamer.EmitLabel(SectionBegin);
1862 // Emit the full data.
1863 AccelNames.Emit(Asm, SectionBegin, &InfoHolder);
1866 // Emit objective C classes and categories into a hashed accelerator table
1868 void DwarfDebug::emitAccelObjC() {
1869 AccelObjC.FinalizeTable(Asm, "ObjC");
1870 Asm->OutStreamer.SwitchSection(
1871 Asm->getObjFileLowering().getDwarfAccelObjCSection());
1872 MCSymbol *SectionBegin = Asm->GetTempSymbol("objc_begin");
1873 Asm->OutStreamer.EmitLabel(SectionBegin);
1875 // Emit the full data.
1876 AccelObjC.Emit(Asm, SectionBegin, &InfoHolder);
1879 // Emit namespace dies into a hashed accelerator table.
1880 void DwarfDebug::emitAccelNamespaces() {
1881 AccelNamespace.FinalizeTable(Asm, "namespac");
1882 Asm->OutStreamer.SwitchSection(
1883 Asm->getObjFileLowering().getDwarfAccelNamespaceSection());
1884 MCSymbol *SectionBegin = Asm->GetTempSymbol("namespac_begin");
1885 Asm->OutStreamer.EmitLabel(SectionBegin);
1887 // Emit the full data.
1888 AccelNamespace.Emit(Asm, SectionBegin, &InfoHolder);
1891 // Emit type dies into a hashed accelerator table.
1892 void DwarfDebug::emitAccelTypes() {
1894 AccelTypes.FinalizeTable(Asm, "types");
1895 Asm->OutStreamer.SwitchSection(
1896 Asm->getObjFileLowering().getDwarfAccelTypesSection());
1897 MCSymbol *SectionBegin = Asm->GetTempSymbol("types_begin");
1898 Asm->OutStreamer.EmitLabel(SectionBegin);
1900 // Emit the full data.
1901 AccelTypes.Emit(Asm, SectionBegin, &InfoHolder);
1904 // Public name handling.
1905 // The format for the various pubnames:
1907 // dwarf pubnames - offset/name pairs where the offset is the offset into the CU
1908 // for the DIE that is named.
1910 // gnu pubnames - offset/index value/name tuples where the offset is the offset
1911 // into the CU and the index value is computed according to the type of value
1912 // for the DIE that is named.
1914 // For type units the offset is the offset of the skeleton DIE. For split dwarf
1915 // it's the offset within the debug_info/debug_types dwo section, however, the
1916 // reference in the pubname header doesn't change.
1918 /// computeIndexValue - Compute the gdb index value for the DIE and CU.
1919 static dwarf::PubIndexEntryDescriptor computeIndexValue(DwarfUnit *CU,
1921 dwarf::GDBIndexEntryLinkage Linkage = dwarf::GIEL_STATIC;
1923 // We could have a specification DIE that has our most of our knowledge,
1924 // look for that now.
1925 DIEValue *SpecVal = Die->findAttribute(dwarf::DW_AT_specification);
1927 DIE &SpecDIE = cast<DIEEntry>(SpecVal)->getEntry();
1928 if (SpecDIE.findAttribute(dwarf::DW_AT_external))
1929 Linkage = dwarf::GIEL_EXTERNAL;
1930 } else if (Die->findAttribute(dwarf::DW_AT_external))
1931 Linkage = dwarf::GIEL_EXTERNAL;
1933 switch (Die->getTag()) {
1934 case dwarf::DW_TAG_class_type:
1935 case dwarf::DW_TAG_structure_type:
1936 case dwarf::DW_TAG_union_type:
1937 case dwarf::DW_TAG_enumeration_type:
1938 return dwarf::PubIndexEntryDescriptor(
1939 dwarf::GIEK_TYPE, CU->getLanguage() != dwarf::DW_LANG_C_plus_plus
1940 ? dwarf::GIEL_STATIC
1941 : dwarf::GIEL_EXTERNAL);
1942 case dwarf::DW_TAG_typedef:
1943 case dwarf::DW_TAG_base_type:
1944 case dwarf::DW_TAG_subrange_type:
1945 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_TYPE, dwarf::GIEL_STATIC);
1946 case dwarf::DW_TAG_namespace:
1947 return dwarf::GIEK_TYPE;
1948 case dwarf::DW_TAG_subprogram:
1949 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_FUNCTION, Linkage);
1950 case dwarf::DW_TAG_constant:
1951 case dwarf::DW_TAG_variable:
1952 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE, Linkage);
1953 case dwarf::DW_TAG_enumerator:
1954 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE,
1955 dwarf::GIEL_STATIC);
1957 return dwarf::GIEK_NONE;
1961 /// emitDebugPubNames - Emit visible names into a debug pubnames section.
1963 void DwarfDebug::emitDebugPubNames(bool GnuStyle) {
1964 const MCSection *PSec =
1965 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubNamesSection()
1966 : Asm->getObjFileLowering().getDwarfPubNamesSection();
1968 emitDebugPubSection(GnuStyle, PSec, "Names", &DwarfUnit::getGlobalNames);
1971 void DwarfDebug::emitDebugPubSection(
1972 bool GnuStyle, const MCSection *PSec, StringRef Name,
1973 const StringMap<const DIE *> &(DwarfUnit::*Accessor)() const) {
1974 for (const auto &NU : CUMap) {
1975 DwarfCompileUnit *TheU = NU.second;
1977 const auto &Globals = (TheU->*Accessor)();
1979 if (Globals.empty())
1982 if (auto Skeleton = static_cast<DwarfCompileUnit *>(TheU->getSkeleton()))
1984 unsigned ID = TheU->getUniqueID();
1986 // Start the dwarf pubnames section.
1987 Asm->OutStreamer.SwitchSection(PSec);
1990 Asm->OutStreamer.AddComment("Length of Public " + Name + " Info");
1991 MCSymbol *BeginLabel = Asm->GetTempSymbol("pub" + Name + "_begin", ID);
1992 MCSymbol *EndLabel = Asm->GetTempSymbol("pub" + Name + "_end", ID);
1993 Asm->EmitLabelDifference(EndLabel, BeginLabel, 4);
1995 Asm->OutStreamer.EmitLabel(BeginLabel);
1997 Asm->OutStreamer.AddComment("DWARF Version");
1998 Asm->EmitInt16(dwarf::DW_PUBNAMES_VERSION);
2000 Asm->OutStreamer.AddComment("Offset of Compilation Unit Info");
2001 Asm->EmitSectionOffset(TheU->getLabelBegin(), TheU->getSectionSym());
2003 Asm->OutStreamer.AddComment("Compilation Unit Length");
2004 Asm->EmitLabelDifference(TheU->getLabelEnd(), TheU->getLabelBegin(), 4);
2006 // Emit the pubnames for this compilation unit.
2007 for (const auto &GI : Globals) {
2008 const char *Name = GI.getKeyData();
2009 const DIE *Entity = GI.second;
2011 Asm->OutStreamer.AddComment("DIE offset");
2012 Asm->EmitInt32(Entity->getOffset());
2015 dwarf::PubIndexEntryDescriptor Desc = computeIndexValue(TheU, Entity);
2016 Asm->OutStreamer.AddComment(
2017 Twine("Kind: ") + dwarf::GDBIndexEntryKindString(Desc.Kind) + ", " +
2018 dwarf::GDBIndexEntryLinkageString(Desc.Linkage));
2019 Asm->EmitInt8(Desc.toBits());
2022 Asm->OutStreamer.AddComment("External Name");
2023 Asm->OutStreamer.EmitBytes(StringRef(Name, GI.getKeyLength() + 1));
2026 Asm->OutStreamer.AddComment("End Mark");
2028 Asm->OutStreamer.EmitLabel(EndLabel);
2032 void DwarfDebug::emitDebugPubTypes(bool GnuStyle) {
2033 const MCSection *PSec =
2034 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubTypesSection()
2035 : Asm->getObjFileLowering().getDwarfPubTypesSection();
2037 emitDebugPubSection(GnuStyle, PSec, "Types", &DwarfUnit::getGlobalTypes);
2040 // Emit visible names into a debug str section.
2041 void DwarfDebug::emitDebugStr() {
2042 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
2043 Holder.emitStrings(Asm->getObjFileLowering().getDwarfStrSection());
2046 /// Emits an optimal (=sorted) sequence of DW_OP_pieces.
2047 void DwarfDebug::emitLocPieces(ByteStreamer &Streamer,
2048 const DITypeIdentifierMap &Map,
2049 ArrayRef<DebugLocEntry::Value> Values) {
2050 typedef DebugLocEntry::Value Piece;
2051 SmallVector<Piece, 4> Pieces(Values.begin(), Values.end());
2052 assert(std::all_of(Pieces.begin(), Pieces.end(), [](Piece &P) {
2053 return DIVariable(P.getVariable()).isVariablePiece();
2054 }) && "all values are expected to be pieces");
2056 // Sort the pieces so they can be emitted using DW_OP_piece.
2057 std::sort(Pieces.begin(), Pieces.end(), [](const Piece &A, const Piece &B) {
2058 DIVariable VarA(A.getVariable());
2059 DIVariable VarB(B.getVariable());
2060 return VarA.getPieceOffset() < VarB.getPieceOffset();
2062 // Remove any duplicate entries by dropping all but the first.
2063 Pieces.erase(std::unique(Pieces.begin(), Pieces.end(),
2064 [] (const Piece &A,const Piece &B){
2065 return A.getVariable() == B.getVariable();
2068 unsigned Offset = 0;
2069 for (auto Piece : Pieces) {
2070 DIVariable Var(Piece.getVariable());
2071 unsigned PieceOffset = Var.getPieceOffset();
2072 unsigned PieceSize = Var.getPieceSize();
2073 assert(Offset <= PieceOffset && "overlapping pieces in DebugLocEntry");
2074 if (Offset < PieceOffset) {
2075 // The DWARF spec seriously mandates pieces with no locations for gaps.
2076 Asm->EmitDwarfOpPiece(Streamer, (PieceOffset-Offset)*8);
2077 Offset += PieceOffset-Offset;
2080 Offset += PieceSize;
2082 const unsigned SizeOfByte = 8;
2083 assert(!Var.isIndirect() && "indirect address for piece");
2085 unsigned VarSize = Var.getSizeInBits(Map);
2086 assert(PieceSize+PieceOffset <= VarSize/SizeOfByte
2087 && "piece is larger than or outside of variable");
2088 assert(PieceSize*SizeOfByte != VarSize
2089 && "piece covers entire variable");
2091 if (Piece.isLocation() && Piece.getLoc().isReg())
2092 Asm->EmitDwarfRegOpPiece(Streamer,
2094 PieceSize*SizeOfByte);
2096 emitDebugLocValue(Streamer, Piece);
2097 Asm->EmitDwarfOpPiece(Streamer, PieceSize*SizeOfByte);
2103 void DwarfDebug::emitDebugLocEntry(ByteStreamer &Streamer,
2104 const DebugLocEntry &Entry) {
2105 const DebugLocEntry::Value Value = Entry.getValues()[0];
2106 DIVariable DV(Value.getVariable());
2107 if (DV.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 // This DIE has the following attributes: DW_AT_comp_dir, DW_AT_dwo_name,
2483 DwarfTypeUnit &DwarfDebug::constructSkeletonTU(DwarfTypeUnit &TU) {
2484 DwarfCompileUnit &CU = static_cast<DwarfCompileUnit &>(
2485 *SkeletonHolder.getUnits()[TU.getCU().getUniqueID()]);
2487 auto OwnedUnit = make_unique<DwarfTypeUnit>(TU.getUniqueID(), CU, Asm, this,
2489 DwarfTypeUnit &NewTU = *OwnedUnit;
2490 NewTU.setTypeSignature(TU.getTypeSignature());
2491 NewTU.setType(nullptr);
2493 Asm->getObjFileLowering().getDwarfTypesSection(TU.getTypeSignature()));
2495 initSkeletonUnit(TU, NewTU.getUnitDie(), std::move(OwnedUnit));
2499 // Emit the .debug_info.dwo section for separated dwarf. This contains the
2500 // compile units that would normally be in debug_info.
2501 void DwarfDebug::emitDebugInfoDWO() {
2502 assert(useSplitDwarf() && "No split dwarf debug info?");
2503 // Don't pass an abbrev symbol, using a constant zero instead so as not to
2504 // emit relocations into the dwo file.
2505 InfoHolder.emitUnits(this, /* AbbrevSymbol */ nullptr);
2508 // Emit the .debug_abbrev.dwo section for separated dwarf. This contains the
2509 // abbreviations for the .debug_info.dwo section.
2510 void DwarfDebug::emitDebugAbbrevDWO() {
2511 assert(useSplitDwarf() && "No split dwarf?");
2512 InfoHolder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevDWOSection());
2515 void DwarfDebug::emitDebugLineDWO() {
2516 assert(useSplitDwarf() && "No split dwarf?");
2517 Asm->OutStreamer.SwitchSection(
2518 Asm->getObjFileLowering().getDwarfLineDWOSection());
2519 SplitTypeUnitFileTable.Emit(Asm->OutStreamer);
2522 // Emit the .debug_str.dwo section for separated dwarf. This contains the
2523 // string section and is identical in format to traditional .debug_str
2525 void DwarfDebug::emitDebugStrDWO() {
2526 assert(useSplitDwarf() && "No split dwarf?");
2527 const MCSection *OffSec =
2528 Asm->getObjFileLowering().getDwarfStrOffDWOSection();
2529 const MCSymbol *StrSym = DwarfStrSectionSym;
2530 InfoHolder.emitStrings(Asm->getObjFileLowering().getDwarfStrDWOSection(),
2534 MCDwarfDwoLineTable *DwarfDebug::getDwoLineTable(const DwarfCompileUnit &CU) {
2535 if (!useSplitDwarf())
2538 SplitTypeUnitFileTable.setCompilationDir(CU.getCUNode().getDirectory());
2539 return &SplitTypeUnitFileTable;
2542 static uint64_t makeTypeSignature(StringRef Identifier) {
2544 Hash.update(Identifier);
2545 // ... take the least significant 8 bytes and return those. Our MD5
2546 // implementation always returns its results in little endian, swap bytes
2548 MD5::MD5Result Result;
2550 return *reinterpret_cast<support::ulittle64_t *>(Result + 8);
2553 void DwarfDebug::addDwarfTypeUnitType(DwarfCompileUnit &CU,
2554 StringRef Identifier, DIE &RefDie,
2555 DICompositeType CTy) {
2556 // Fast path if we're building some type units and one has already used the
2557 // address pool we know we're going to throw away all this work anyway, so
2558 // don't bother building dependent types.
2559 if (!TypeUnitsUnderConstruction.empty() && AddrPool.hasBeenUsed())
2562 const DwarfTypeUnit *&TU = DwarfTypeUnits[CTy];
2564 CU.addDIETypeSignature(RefDie, *TU);
2568 bool TopLevelType = TypeUnitsUnderConstruction.empty();
2569 AddrPool.resetUsedFlag();
2571 auto OwnedUnit = make_unique<DwarfTypeUnit>(
2572 InfoHolder.getUnits().size() + TypeUnitsUnderConstruction.size(), CU, Asm,
2573 this, &InfoHolder, getDwoLineTable(CU));
2574 DwarfTypeUnit &NewTU = *OwnedUnit;
2575 DIE &UnitDie = NewTU.getUnitDie();
2577 TypeUnitsUnderConstruction.push_back(
2578 std::make_pair(std::move(OwnedUnit), CTy));
2580 NewTU.addUInt(UnitDie, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
2583 uint64_t Signature = makeTypeSignature(Identifier);
2584 NewTU.setTypeSignature(Signature);
2586 if (useSplitDwarf())
2587 NewTU.initSection(Asm->getObjFileLowering().getDwarfTypesDWOSection(),
2588 DwarfTypesDWOSectionSym);
2590 CU.applyStmtList(UnitDie);
2592 Asm->getObjFileLowering().getDwarfTypesSection(Signature));
2595 NewTU.setType(NewTU.createTypeDIE(CTy));
2598 auto TypeUnitsToAdd = std::move(TypeUnitsUnderConstruction);
2599 TypeUnitsUnderConstruction.clear();
2601 // Types referencing entries in the address table cannot be placed in type
2603 if (AddrPool.hasBeenUsed()) {
2605 // Remove all the types built while building this type.
2606 // This is pessimistic as some of these types might not be dependent on
2607 // the type that used an address.
2608 for (const auto &TU : TypeUnitsToAdd)
2609 DwarfTypeUnits.erase(TU.second);
2611 // Construct this type in the CU directly.
2612 // This is inefficient because all the dependent types will be rebuilt
2613 // from scratch, including building them in type units, discovering that
2614 // they depend on addresses, throwing them out and rebuilding them.
2615 CU.constructTypeDIE(RefDie, CTy);
2619 // If the type wasn't dependent on fission addresses, finish adding the type
2620 // and all its dependent types.
2621 for (auto &TU : TypeUnitsToAdd) {
2622 if (useSplitDwarf())
2623 TU.first->setSkeleton(constructSkeletonTU(*TU.first));
2624 InfoHolder.addUnit(std::move(TU.first));
2627 CU.addDIETypeSignature(RefDie, NewTU);
2630 void DwarfDebug::attachLowHighPC(DwarfCompileUnit &Unit, DIE &D,
2631 MCSymbol *Begin, MCSymbol *End) {
2632 assert(Begin && "Begin label should not be null!");
2633 assert(End && "End label should not be null!");
2634 assert(Begin->isDefined() && "Invalid starting label");
2635 assert(End->isDefined() && "Invalid end label");
2637 Unit.addLabelAddress(D, dwarf::DW_AT_low_pc, Begin);
2638 if (DwarfVersion < 4)
2639 Unit.addLabelAddress(D, dwarf::DW_AT_high_pc, End);
2641 Unit.addLabelDelta(D, dwarf::DW_AT_high_pc, End, Begin);
2644 // Accelerator table mutators - add each name along with its companion
2645 // DIE to the proper table while ensuring that the name that we're going
2646 // to reference is in the string table. We do this since the names we
2647 // add may not only be identical to the names in the DIE.
2648 void DwarfDebug::addAccelName(StringRef Name, const DIE &Die) {
2649 if (!useDwarfAccelTables())
2651 AccelNames.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2655 void DwarfDebug::addAccelObjC(StringRef Name, const DIE &Die) {
2656 if (!useDwarfAccelTables())
2658 AccelObjC.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2662 void DwarfDebug::addAccelNamespace(StringRef Name, const DIE &Die) {
2663 if (!useDwarfAccelTables())
2665 AccelNamespace.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2669 void DwarfDebug::addAccelType(StringRef Name, const DIE &Die, char Flags) {
2670 if (!useDwarfAccelTables())
2672 AccelTypes.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),