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 bool couldMerge = false;
1277 // If this is a piece, it may belong to the current DebugLocEntry.
1278 if (DIVar.isVariablePiece()) {
1279 // Add this value to the list of open ranges.
1280 OpenRanges.push_back(std::make_pair(DIVar, Value));
1282 // Attempt to add the piece to the last entry.
1283 if (!DebugLoc.empty())
1284 if (DebugLoc.back().MergeValues(Loc))
1289 // Need to add a new DebugLocEntry. Add all values from still
1290 // valid non-overlapping pieces.
1291 for (auto Range : OpenRanges)
1292 Loc.addValue(Range.second);
1293 DebugLoc.push_back(std::move(Loc));
1296 // Attempt to coalesce the ranges of two otherwise identical
1298 auto CurEntry = DebugLoc.rbegin();
1299 auto PrevEntry = std::next(CurEntry);
1300 if (PrevEntry != DebugLoc.rend() && PrevEntry->MergeRanges(*CurEntry))
1301 DebugLoc.pop_back();
1303 DEBUG(dbgs() << "Values:\n";
1304 for (auto Value : CurEntry->getValues())
1305 Value.getVariable()->dump();
1306 dbgs() << "-----\n");
1311 // Find variables for each lexical scope.
1313 DwarfDebug::collectVariableInfo(SmallPtrSet<const MDNode *, 16> &Processed) {
1314 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1315 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1317 // Grab the variable info that was squirreled away in the MMI side-table.
1318 collectVariableInfoFromMMITable(Processed);
1320 for (const auto &I : DbgValues) {
1321 DIVariable DV(I.first);
1322 if (Processed.count(DV))
1325 // Instruction ranges, specifying where DV is accessible.
1326 const auto &Ranges = I.second;
1330 LexicalScope *Scope = nullptr;
1331 if (MDNode *IA = DV.getInlinedAt()) {
1332 DebugLoc DL = DebugLoc::getFromDILocation(IA);
1333 Scope = LScopes.findInlinedScope(DebugLoc::get(
1334 DL.getLine(), DL.getCol(), DV.getContext(), IA));
1336 Scope = LScopes.findLexicalScope(DV.getContext());
1337 // If variable scope is not found then skip this variable.
1341 Processed.insert(getEntireVariable(DV));
1342 const MachineInstr *MInsn = Ranges.front().first;
1343 assert(MInsn->isDebugValue() && "History must begin with debug value");
1344 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
1345 ConcreteVariables.push_back(make_unique<DbgVariable>(MInsn, this));
1346 DbgVariable *RegVar = ConcreteVariables.back().get();
1347 addScopeVariable(Scope, RegVar);
1349 // Check if the first DBG_VALUE is valid for the rest of the function.
1350 if (Ranges.size() == 1 && Ranges.front().second == nullptr)
1353 // Handle multiple DBG_VALUE instructions describing one variable.
1354 RegVar->setDotDebugLocOffset(DotDebugLocEntries.size());
1356 DotDebugLocEntries.resize(DotDebugLocEntries.size() + 1);
1357 DebugLocList &LocList = DotDebugLocEntries.back();
1360 Asm->GetTempSymbol("debug_loc", DotDebugLocEntries.size() - 1);
1362 // Build the location list for this variable.
1363 buildLocationList(LocList.List, Ranges);
1366 // Collect info for variables that were optimized out.
1367 DIArray Variables = DISubprogram(FnScope->getScopeNode()).getVariables();
1368 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1369 DIVariable DV(Variables.getElement(i));
1370 assert(DV.isVariable());
1371 if (!Processed.insert(DV))
1373 if (LexicalScope *Scope = LScopes.findLexicalScope(DV.getContext())) {
1374 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
1375 ConcreteVariables.push_back(make_unique<DbgVariable>(DV, this));
1376 addScopeVariable(Scope, ConcreteVariables.back().get());
1381 // Return Label preceding the instruction.
1382 MCSymbol *DwarfDebug::getLabelBeforeInsn(const MachineInstr *MI) {
1383 MCSymbol *Label = LabelsBeforeInsn.lookup(MI);
1384 assert(Label && "Didn't insert label before instruction");
1388 // Return Label immediately following the instruction.
1389 MCSymbol *DwarfDebug::getLabelAfterInsn(const MachineInstr *MI) {
1390 return LabelsAfterInsn.lookup(MI);
1393 // Process beginning of an instruction.
1394 void DwarfDebug::beginInstruction(const MachineInstr *MI) {
1395 assert(CurMI == nullptr);
1397 // Check if source location changes, but ignore DBG_VALUE locations.
1398 if (!MI->isDebugValue()) {
1399 DebugLoc DL = MI->getDebugLoc();
1400 if (DL != PrevInstLoc && (!DL.isUnknown() || UnknownLocations)) {
1403 if (DL == PrologEndLoc) {
1404 Flags |= DWARF2_FLAG_PROLOGUE_END;
1405 PrologEndLoc = DebugLoc();
1407 if (PrologEndLoc.isUnknown())
1408 Flags |= DWARF2_FLAG_IS_STMT;
1410 if (!DL.isUnknown()) {
1411 const MDNode *Scope = DL.getScope(Asm->MF->getFunction()->getContext());
1412 recordSourceLine(DL.getLine(), DL.getCol(), Scope, Flags);
1414 recordSourceLine(0, 0, nullptr, 0);
1418 // Insert labels where requested.
1419 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1420 LabelsBeforeInsn.find(MI);
1423 if (I == LabelsBeforeInsn.end())
1426 // Label already assigned.
1431 PrevLabel = MMI->getContext().CreateTempSymbol();
1432 Asm->OutStreamer.EmitLabel(PrevLabel);
1434 I->second = PrevLabel;
1437 // Process end of an instruction.
1438 void DwarfDebug::endInstruction() {
1439 assert(CurMI != nullptr);
1440 // Don't create a new label after DBG_VALUE instructions.
1441 // They don't generate code.
1442 if (!CurMI->isDebugValue())
1443 PrevLabel = nullptr;
1445 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1446 LabelsAfterInsn.find(CurMI);
1450 if (I == LabelsAfterInsn.end())
1453 // Label already assigned.
1457 // We need a label after this instruction.
1459 PrevLabel = MMI->getContext().CreateTempSymbol();
1460 Asm->OutStreamer.EmitLabel(PrevLabel);
1462 I->second = PrevLabel;
1465 // Each LexicalScope has first instruction and last instruction to mark
1466 // beginning and end of a scope respectively. Create an inverse map that list
1467 // scopes starts (and ends) with an instruction. One instruction may start (or
1468 // end) multiple scopes. Ignore scopes that are not reachable.
1469 void DwarfDebug::identifyScopeMarkers() {
1470 SmallVector<LexicalScope *, 4> WorkList;
1471 WorkList.push_back(LScopes.getCurrentFunctionScope());
1472 while (!WorkList.empty()) {
1473 LexicalScope *S = WorkList.pop_back_val();
1475 const SmallVectorImpl<LexicalScope *> &Children = S->getChildren();
1476 if (!Children.empty())
1477 WorkList.append(Children.begin(), Children.end());
1479 if (S->isAbstractScope())
1482 for (const InsnRange &R : S->getRanges()) {
1483 assert(R.first && "InsnRange does not have first instruction!");
1484 assert(R.second && "InsnRange does not have second instruction!");
1485 requestLabelBeforeInsn(R.first);
1486 requestLabelAfterInsn(R.second);
1491 static DebugLoc findPrologueEndLoc(const MachineFunction *MF) {
1492 // First known non-DBG_VALUE and non-frame setup location marks
1493 // the beginning of the function body.
1494 for (const auto &MBB : *MF)
1495 for (const auto &MI : MBB)
1496 if (!MI.isDebugValue() && !MI.getFlag(MachineInstr::FrameSetup) &&
1497 !MI.getDebugLoc().isUnknown())
1498 return MI.getDebugLoc();
1502 // Gather pre-function debug information. Assumes being called immediately
1503 // after the function entry point has been emitted.
1504 void DwarfDebug::beginFunction(const MachineFunction *MF) {
1507 // If there's no debug info for the function we're not going to do anything.
1508 if (!MMI->hasDebugInfo())
1511 auto DI = FunctionDIs.find(MF->getFunction());
1512 if (DI == FunctionDIs.end())
1515 // Grab the lexical scopes for the function, if we don't have any of those
1516 // then we're not going to be able to do anything.
1517 LScopes.initialize(*MF);
1518 if (LScopes.empty())
1521 assert(DbgValues.empty() && "DbgValues map wasn't cleaned!");
1523 // Make sure that each lexical scope will have a begin/end label.
1524 identifyScopeMarkers();
1526 // Set DwarfDwarfCompileUnitID in MCContext to the Compile Unit this function
1527 // belongs to so that we add to the correct per-cu line table in the
1529 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1530 // FnScope->getScopeNode() and DI->second should represent the same function,
1531 // though they may not be the same MDNode due to inline functions merged in
1532 // LTO where the debug info metadata still differs (either due to distinct
1533 // written differences - two versions of a linkonce_odr function
1534 // written/copied into two separate files, or some sub-optimal metadata that
1535 // isn't structurally identical (see: file path/name info from clang, which
1536 // includes the directory of the cpp file being built, even when the file name
1537 // is absolute (such as an <> lookup header)))
1538 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1539 assert(TheCU && "Unable to find compile unit!");
1540 if (Asm->OutStreamer.hasRawTextSupport())
1541 // Use a single line table if we are generating assembly.
1542 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1544 Asm->OutStreamer.getContext().setDwarfCompileUnitID(TheCU->getUniqueID());
1546 // Emit a label for the function so that we have a beginning address.
1547 FunctionBeginSym = Asm->GetTempSymbol("func_begin", Asm->getFunctionNumber());
1548 // Assumes in correct section after the entry point.
1549 Asm->OutStreamer.EmitLabel(FunctionBeginSym);
1551 // Calculate history for local variables.
1552 calculateDbgValueHistory(MF, Asm->TM.getSubtargetImpl()->getRegisterInfo(),
1555 // Request labels for the full history.
1556 for (const auto &I : DbgValues) {
1557 const auto &Ranges = I.second;
1561 // The first mention of a function argument gets the FunctionBeginSym
1562 // label, so arguments are visible when breaking at function entry.
1563 DIVariable DV(Ranges.front().first->getDebugVariable());
1564 if (DV.isVariable() && DV.getTag() == dwarf::DW_TAG_arg_variable &&
1565 getDISubprogram(DV.getContext()).describes(MF->getFunction())) {
1566 if (!DV.isVariablePiece())
1567 LabelsBeforeInsn[Ranges.front().first] = FunctionBeginSym;
1569 // Mark all non-overlapping initial pieces.
1570 for (auto I = Ranges.begin(); I != Ranges.end(); ++I) {
1571 DIVariable Piece = I->first->getDebugVariable();
1572 if (std::all_of(Ranges.begin(), I,
1573 [&](DbgValueHistoryMap::InstrRange Pred){
1574 return !piecesOverlap(Piece, Pred.first->getDebugVariable());
1576 LabelsBeforeInsn[I->first] = FunctionBeginSym;
1583 for (const auto &Range : Ranges) {
1584 requestLabelBeforeInsn(Range.first);
1586 requestLabelAfterInsn(Range.second);
1590 PrevInstLoc = DebugLoc();
1591 PrevLabel = FunctionBeginSym;
1593 // Record beginning of function.
1594 PrologEndLoc = findPrologueEndLoc(MF);
1595 if (!PrologEndLoc.isUnknown()) {
1596 DebugLoc FnStartDL =
1597 PrologEndLoc.getFnDebugLoc(MF->getFunction()->getContext());
1599 FnStartDL.getLine(), FnStartDL.getCol(),
1600 FnStartDL.getScope(MF->getFunction()->getContext()),
1601 // We'd like to list the prologue as "not statements" but GDB behaves
1602 // poorly if we do that. Revisit this with caution/GDB (7.5+) testing.
1603 DWARF2_FLAG_IS_STMT);
1607 void DwarfDebug::addScopeVariable(LexicalScope *LS, DbgVariable *Var) {
1608 if (addCurrentFnArgument(Var, LS))
1610 SmallVectorImpl<DbgVariable *> &Vars = ScopeVariables[LS];
1611 DIVariable DV = Var->getVariable();
1612 // Variables with positive arg numbers are parameters.
1613 if (unsigned ArgNum = DV.getArgNumber()) {
1614 // Keep all parameters in order at the start of the variable list to ensure
1615 // function types are correct (no out-of-order parameters)
1617 // This could be improved by only doing it for optimized builds (unoptimized
1618 // builds have the right order to begin with), searching from the back (this
1619 // would catch the unoptimized case quickly), or doing a binary search
1620 // rather than linear search.
1621 SmallVectorImpl<DbgVariable *>::iterator I = Vars.begin();
1622 while (I != Vars.end()) {
1623 unsigned CurNum = (*I)->getVariable().getArgNumber();
1624 // A local (non-parameter) variable has been found, insert immediately
1628 // A later indexed parameter has been found, insert immediately before it.
1629 if (CurNum > ArgNum)
1633 Vars.insert(I, Var);
1637 Vars.push_back(Var);
1640 // Gather and emit post-function debug information.
1641 void DwarfDebug::endFunction(const MachineFunction *MF) {
1642 // Every beginFunction(MF) call should be followed by an endFunction(MF) call,
1643 // though the beginFunction may not be called at all.
1644 // We should handle both cases.
1648 assert(CurFn == MF);
1649 assert(CurFn != nullptr);
1651 if (!MMI->hasDebugInfo() || LScopes.empty() ||
1652 !FunctionDIs.count(MF->getFunction())) {
1653 // If we don't have a lexical scope for this function then there will
1654 // be a hole in the range information. Keep note of this by setting the
1655 // previously used section to nullptr.
1656 PrevSection = nullptr;
1662 // Define end label for subprogram.
1663 FunctionEndSym = Asm->GetTempSymbol("func_end", Asm->getFunctionNumber());
1664 // Assumes in correct section after the entry point.
1665 Asm->OutStreamer.EmitLabel(FunctionEndSym);
1667 // Set DwarfDwarfCompileUnitID in MCContext to default value.
1668 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1670 SmallPtrSet<const MDNode *, 16> ProcessedVars;
1671 collectVariableInfo(ProcessedVars);
1673 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1674 DwarfCompileUnit &TheCU = *SPMap.lookup(FnScope->getScopeNode());
1676 // Construct abstract scopes.
1677 for (LexicalScope *AScope : LScopes.getAbstractScopesList()) {
1678 DISubprogram SP(AScope->getScopeNode());
1679 assert(SP.isSubprogram());
1680 // Collect info for variables that were optimized out.
1681 DIArray Variables = SP.getVariables();
1682 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1683 DIVariable DV(Variables.getElement(i));
1684 assert(DV && DV.isVariable());
1685 if (!ProcessedVars.insert(DV))
1687 ensureAbstractVariableIsCreated(DV, DV.getContext());
1689 constructAbstractSubprogramScopeDIE(TheCU, AScope);
1692 DIE &CurFnDIE = constructSubprogramScopeDIE(TheCU, FnScope);
1693 if (!CurFn->getTarget().Options.DisableFramePointerElim(*CurFn))
1694 TheCU.addFlag(CurFnDIE, dwarf::DW_AT_APPLE_omit_frame_ptr);
1696 // Add the range of this function to the list of ranges for the CU.
1697 RangeSpan Span(FunctionBeginSym, FunctionEndSym);
1698 TheCU.addRange(std::move(Span));
1699 PrevSection = Asm->getCurrentSection();
1703 // Ownership of DbgVariables is a bit subtle - ScopeVariables owns all the
1704 // DbgVariables except those that are also in AbstractVariables (since they
1705 // can be used cross-function)
1706 ScopeVariables.clear();
1707 CurrentFnArguments.clear();
1709 LabelsBeforeInsn.clear();
1710 LabelsAfterInsn.clear();
1711 PrevLabel = nullptr;
1715 // Register a source line with debug info. Returns the unique label that was
1716 // emitted and which provides correspondence to the source line list.
1717 void DwarfDebug::recordSourceLine(unsigned Line, unsigned Col, const MDNode *S,
1722 unsigned Discriminator = 0;
1723 if (DIScope Scope = DIScope(S)) {
1724 assert(Scope.isScope());
1725 Fn = Scope.getFilename();
1726 Dir = Scope.getDirectory();
1727 if (Scope.isLexicalBlock())
1728 Discriminator = DILexicalBlock(S).getDiscriminator();
1730 unsigned CUID = Asm->OutStreamer.getContext().getDwarfCompileUnitID();
1731 Src = static_cast<DwarfCompileUnit &>(*InfoHolder.getUnits()[CUID])
1732 .getOrCreateSourceID(Fn, Dir);
1734 Asm->OutStreamer.EmitDwarfLocDirective(Src, Line, Col, Flags, 0,
1738 //===----------------------------------------------------------------------===//
1740 //===----------------------------------------------------------------------===//
1742 // Emit initial Dwarf sections with a label at the start of each one.
1743 void DwarfDebug::emitSectionLabels() {
1744 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
1746 // Dwarf sections base addresses.
1747 DwarfInfoSectionSym =
1748 emitSectionSym(Asm, TLOF.getDwarfInfoSection(), "section_info");
1749 if (useSplitDwarf()) {
1750 DwarfInfoDWOSectionSym =
1751 emitSectionSym(Asm, TLOF.getDwarfInfoDWOSection(), "section_info_dwo");
1752 DwarfTypesDWOSectionSym =
1753 emitSectionSym(Asm, TLOF.getDwarfTypesDWOSection(), "section_types_dwo");
1755 DwarfAbbrevSectionSym =
1756 emitSectionSym(Asm, TLOF.getDwarfAbbrevSection(), "section_abbrev");
1757 if (useSplitDwarf())
1758 DwarfAbbrevDWOSectionSym = emitSectionSym(
1759 Asm, TLOF.getDwarfAbbrevDWOSection(), "section_abbrev_dwo");
1760 if (GenerateARangeSection)
1761 emitSectionSym(Asm, TLOF.getDwarfARangesSection());
1763 DwarfLineSectionSym =
1764 emitSectionSym(Asm, TLOF.getDwarfLineSection(), "section_line");
1765 if (GenerateGnuPubSections) {
1766 DwarfGnuPubNamesSectionSym =
1767 emitSectionSym(Asm, TLOF.getDwarfGnuPubNamesSection());
1768 DwarfGnuPubTypesSectionSym =
1769 emitSectionSym(Asm, TLOF.getDwarfGnuPubTypesSection());
1770 } else if (HasDwarfPubSections) {
1771 emitSectionSym(Asm, TLOF.getDwarfPubNamesSection());
1772 emitSectionSym(Asm, TLOF.getDwarfPubTypesSection());
1775 DwarfStrSectionSym =
1776 emitSectionSym(Asm, TLOF.getDwarfStrSection(), "info_string");
1777 if (useSplitDwarf()) {
1778 DwarfStrDWOSectionSym =
1779 emitSectionSym(Asm, TLOF.getDwarfStrDWOSection(), "skel_string");
1780 DwarfAddrSectionSym =
1781 emitSectionSym(Asm, TLOF.getDwarfAddrSection(), "addr_sec");
1782 DwarfDebugLocSectionSym =
1783 emitSectionSym(Asm, TLOF.getDwarfLocDWOSection(), "skel_loc");
1785 DwarfDebugLocSectionSym =
1786 emitSectionSym(Asm, TLOF.getDwarfLocSection(), "section_debug_loc");
1787 DwarfDebugRangeSectionSym =
1788 emitSectionSym(Asm, TLOF.getDwarfRangesSection(), "debug_range");
1791 // Recursively emits a debug information entry.
1792 void DwarfDebug::emitDIE(DIE &Die) {
1793 // Get the abbreviation for this DIE.
1794 const DIEAbbrev &Abbrev = Die.getAbbrev();
1796 // Emit the code (index) for the abbreviation.
1797 if (Asm->isVerbose())
1798 Asm->OutStreamer.AddComment("Abbrev [" + Twine(Abbrev.getNumber()) +
1799 "] 0x" + Twine::utohexstr(Die.getOffset()) +
1800 ":0x" + Twine::utohexstr(Die.getSize()) + " " +
1801 dwarf::TagString(Abbrev.getTag()));
1802 Asm->EmitULEB128(Abbrev.getNumber());
1804 const SmallVectorImpl<DIEValue *> &Values = Die.getValues();
1805 const SmallVectorImpl<DIEAbbrevData> &AbbrevData = Abbrev.getData();
1807 // Emit the DIE attribute values.
1808 for (unsigned i = 0, N = Values.size(); i < N; ++i) {
1809 dwarf::Attribute Attr = AbbrevData[i].getAttribute();
1810 dwarf::Form Form = AbbrevData[i].getForm();
1811 assert(Form && "Too many attributes for DIE (check abbreviation)");
1813 if (Asm->isVerbose()) {
1814 Asm->OutStreamer.AddComment(dwarf::AttributeString(Attr));
1815 if (Attr == dwarf::DW_AT_accessibility)
1816 Asm->OutStreamer.AddComment(dwarf::AccessibilityString(
1817 cast<DIEInteger>(Values[i])->getValue()));
1820 // Emit an attribute using the defined form.
1821 Values[i]->EmitValue(Asm, Form);
1824 // Emit the DIE children if any.
1825 if (Abbrev.hasChildren()) {
1826 for (auto &Child : Die.getChildren())
1829 Asm->OutStreamer.AddComment("End Of Children Mark");
1834 // Emit the debug info section.
1835 void DwarfDebug::emitDebugInfo() {
1836 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1838 Holder.emitUnits(this, DwarfAbbrevSectionSym);
1841 // Emit the abbreviation section.
1842 void DwarfDebug::emitAbbreviations() {
1843 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1845 Holder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevSection());
1848 // Emit the last address of the section and the end of the line matrix.
1849 void DwarfDebug::emitEndOfLineMatrix(unsigned SectionEnd) {
1850 // Define last address of section.
1851 Asm->OutStreamer.AddComment("Extended Op");
1854 Asm->OutStreamer.AddComment("Op size");
1855 Asm->EmitInt8(Asm->getDataLayout().getPointerSize() + 1);
1856 Asm->OutStreamer.AddComment("DW_LNE_set_address");
1857 Asm->EmitInt8(dwarf::DW_LNE_set_address);
1859 Asm->OutStreamer.AddComment("Section end label");
1861 Asm->OutStreamer.EmitSymbolValue(
1862 Asm->GetTempSymbol("section_end", SectionEnd),
1863 Asm->getDataLayout().getPointerSize());
1865 // Mark end of matrix.
1866 Asm->OutStreamer.AddComment("DW_LNE_end_sequence");
1872 // Emit visible names into a hashed accelerator table section.
1873 void DwarfDebug::emitAccelNames() {
1874 AccelNames.FinalizeTable(Asm, "Names");
1875 Asm->OutStreamer.SwitchSection(
1876 Asm->getObjFileLowering().getDwarfAccelNamesSection());
1877 MCSymbol *SectionBegin = Asm->GetTempSymbol("names_begin");
1878 Asm->OutStreamer.EmitLabel(SectionBegin);
1880 // Emit the full data.
1881 AccelNames.Emit(Asm, SectionBegin, &InfoHolder);
1884 // Emit objective C classes and categories into a hashed accelerator table
1886 void DwarfDebug::emitAccelObjC() {
1887 AccelObjC.FinalizeTable(Asm, "ObjC");
1888 Asm->OutStreamer.SwitchSection(
1889 Asm->getObjFileLowering().getDwarfAccelObjCSection());
1890 MCSymbol *SectionBegin = Asm->GetTempSymbol("objc_begin");
1891 Asm->OutStreamer.EmitLabel(SectionBegin);
1893 // Emit the full data.
1894 AccelObjC.Emit(Asm, SectionBegin, &InfoHolder);
1897 // Emit namespace dies into a hashed accelerator table.
1898 void DwarfDebug::emitAccelNamespaces() {
1899 AccelNamespace.FinalizeTable(Asm, "namespac");
1900 Asm->OutStreamer.SwitchSection(
1901 Asm->getObjFileLowering().getDwarfAccelNamespaceSection());
1902 MCSymbol *SectionBegin = Asm->GetTempSymbol("namespac_begin");
1903 Asm->OutStreamer.EmitLabel(SectionBegin);
1905 // Emit the full data.
1906 AccelNamespace.Emit(Asm, SectionBegin, &InfoHolder);
1909 // Emit type dies into a hashed accelerator table.
1910 void DwarfDebug::emitAccelTypes() {
1912 AccelTypes.FinalizeTable(Asm, "types");
1913 Asm->OutStreamer.SwitchSection(
1914 Asm->getObjFileLowering().getDwarfAccelTypesSection());
1915 MCSymbol *SectionBegin = Asm->GetTempSymbol("types_begin");
1916 Asm->OutStreamer.EmitLabel(SectionBegin);
1918 // Emit the full data.
1919 AccelTypes.Emit(Asm, SectionBegin, &InfoHolder);
1922 // Public name handling.
1923 // The format for the various pubnames:
1925 // dwarf pubnames - offset/name pairs where the offset is the offset into the CU
1926 // for the DIE that is named.
1928 // gnu pubnames - offset/index value/name tuples where the offset is the offset
1929 // into the CU and the index value is computed according to the type of value
1930 // for the DIE that is named.
1932 // For type units the offset is the offset of the skeleton DIE. For split dwarf
1933 // it's the offset within the debug_info/debug_types dwo section, however, the
1934 // reference in the pubname header doesn't change.
1936 /// computeIndexValue - Compute the gdb index value for the DIE and CU.
1937 static dwarf::PubIndexEntryDescriptor computeIndexValue(DwarfUnit *CU,
1939 dwarf::GDBIndexEntryLinkage Linkage = dwarf::GIEL_STATIC;
1941 // We could have a specification DIE that has our most of our knowledge,
1942 // look for that now.
1943 DIEValue *SpecVal = Die->findAttribute(dwarf::DW_AT_specification);
1945 DIE &SpecDIE = cast<DIEEntry>(SpecVal)->getEntry();
1946 if (SpecDIE.findAttribute(dwarf::DW_AT_external))
1947 Linkage = dwarf::GIEL_EXTERNAL;
1948 } else if (Die->findAttribute(dwarf::DW_AT_external))
1949 Linkage = dwarf::GIEL_EXTERNAL;
1951 switch (Die->getTag()) {
1952 case dwarf::DW_TAG_class_type:
1953 case dwarf::DW_TAG_structure_type:
1954 case dwarf::DW_TAG_union_type:
1955 case dwarf::DW_TAG_enumeration_type:
1956 return dwarf::PubIndexEntryDescriptor(
1957 dwarf::GIEK_TYPE, CU->getLanguage() != dwarf::DW_LANG_C_plus_plus
1958 ? dwarf::GIEL_STATIC
1959 : dwarf::GIEL_EXTERNAL);
1960 case dwarf::DW_TAG_typedef:
1961 case dwarf::DW_TAG_base_type:
1962 case dwarf::DW_TAG_subrange_type:
1963 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_TYPE, dwarf::GIEL_STATIC);
1964 case dwarf::DW_TAG_namespace:
1965 return dwarf::GIEK_TYPE;
1966 case dwarf::DW_TAG_subprogram:
1967 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_FUNCTION, Linkage);
1968 case dwarf::DW_TAG_constant:
1969 case dwarf::DW_TAG_variable:
1970 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE, Linkage);
1971 case dwarf::DW_TAG_enumerator:
1972 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE,
1973 dwarf::GIEL_STATIC);
1975 return dwarf::GIEK_NONE;
1979 /// emitDebugPubNames - Emit visible names into a debug pubnames section.
1981 void DwarfDebug::emitDebugPubNames(bool GnuStyle) {
1982 const MCSection *PSec =
1983 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubNamesSection()
1984 : Asm->getObjFileLowering().getDwarfPubNamesSection();
1986 emitDebugPubSection(GnuStyle, PSec, "Names", &DwarfUnit::getGlobalNames);
1989 void DwarfDebug::emitDebugPubSection(
1990 bool GnuStyle, const MCSection *PSec, StringRef Name,
1991 const StringMap<const DIE *> &(DwarfUnit::*Accessor)() const) {
1992 for (const auto &NU : CUMap) {
1993 DwarfCompileUnit *TheU = NU.second;
1995 const auto &Globals = (TheU->*Accessor)();
1997 if (Globals.empty())
2000 if (auto Skeleton = static_cast<DwarfCompileUnit *>(TheU->getSkeleton()))
2002 unsigned ID = TheU->getUniqueID();
2004 // Start the dwarf pubnames section.
2005 Asm->OutStreamer.SwitchSection(PSec);
2008 Asm->OutStreamer.AddComment("Length of Public " + Name + " Info");
2009 MCSymbol *BeginLabel = Asm->GetTempSymbol("pub" + Name + "_begin", ID);
2010 MCSymbol *EndLabel = Asm->GetTempSymbol("pub" + Name + "_end", ID);
2011 Asm->EmitLabelDifference(EndLabel, BeginLabel, 4);
2013 Asm->OutStreamer.EmitLabel(BeginLabel);
2015 Asm->OutStreamer.AddComment("DWARF Version");
2016 Asm->EmitInt16(dwarf::DW_PUBNAMES_VERSION);
2018 Asm->OutStreamer.AddComment("Offset of Compilation Unit Info");
2019 Asm->EmitSectionOffset(TheU->getLabelBegin(), TheU->getSectionSym());
2021 Asm->OutStreamer.AddComment("Compilation Unit Length");
2022 Asm->EmitLabelDifference(TheU->getLabelEnd(), TheU->getLabelBegin(), 4);
2024 // Emit the pubnames for this compilation unit.
2025 for (const auto &GI : Globals) {
2026 const char *Name = GI.getKeyData();
2027 const DIE *Entity = GI.second;
2029 Asm->OutStreamer.AddComment("DIE offset");
2030 Asm->EmitInt32(Entity->getOffset());
2033 dwarf::PubIndexEntryDescriptor Desc = computeIndexValue(TheU, Entity);
2034 Asm->OutStreamer.AddComment(
2035 Twine("Kind: ") + dwarf::GDBIndexEntryKindString(Desc.Kind) + ", " +
2036 dwarf::GDBIndexEntryLinkageString(Desc.Linkage));
2037 Asm->EmitInt8(Desc.toBits());
2040 Asm->OutStreamer.AddComment("External Name");
2041 Asm->OutStreamer.EmitBytes(StringRef(Name, GI.getKeyLength() + 1));
2044 Asm->OutStreamer.AddComment("End Mark");
2046 Asm->OutStreamer.EmitLabel(EndLabel);
2050 void DwarfDebug::emitDebugPubTypes(bool GnuStyle) {
2051 const MCSection *PSec =
2052 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubTypesSection()
2053 : Asm->getObjFileLowering().getDwarfPubTypesSection();
2055 emitDebugPubSection(GnuStyle, PSec, "Types", &DwarfUnit::getGlobalTypes);
2058 // Emit visible names into a debug str section.
2059 void DwarfDebug::emitDebugStr() {
2060 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
2061 Holder.emitStrings(Asm->getObjFileLowering().getDwarfStrSection());
2064 /// Emits an optimal (=sorted) sequence of DW_OP_pieces.
2065 void DwarfDebug::emitLocPieces(ByteStreamer &Streamer,
2066 const DITypeIdentifierMap &Map,
2067 ArrayRef<DebugLocEntry::Value> Values) {
2068 typedef DebugLocEntry::Value Piece;
2069 SmallVector<Piece, 4> Pieces(Values.begin(), Values.end());
2070 assert(std::all_of(Pieces.begin(), Pieces.end(), [](Piece &P) {
2071 return DIVariable(P.getVariable()).isVariablePiece();
2072 }) && "all values are expected to be pieces");
2074 // Sort the pieces so they can be emitted using DW_OP_piece.
2075 std::sort(Pieces.begin(), Pieces.end(), [](const Piece &A, const Piece &B) {
2076 DIVariable VarA(A.getVariable());
2077 DIVariable VarB(B.getVariable());
2078 return VarA.getPieceOffset() < VarB.getPieceOffset();
2080 // Remove any duplicate entries by dropping all but the first.
2081 Pieces.erase(std::unique(Pieces.begin(), Pieces.end(),
2082 [] (const Piece &A,const Piece &B){
2083 return A.getVariable() == B.getVariable();
2086 unsigned Offset = 0;
2087 for (auto Piece : Pieces) {
2088 DIVariable Var(Piece.getVariable());
2089 unsigned PieceOffset = Var.getPieceOffset();
2090 unsigned PieceSize = Var.getPieceSize();
2091 assert(Offset <= PieceOffset && "overlapping pieces in DebugLocEntry");
2092 if (Offset < PieceOffset) {
2093 // The DWARF spec seriously mandates pieces with no locations for gaps.
2094 Asm->EmitDwarfOpPiece(Streamer, (PieceOffset-Offset)*8);
2095 Offset += PieceOffset-Offset;
2098 Offset += PieceSize;
2100 const unsigned SizeOfByte = 8;
2101 assert(!Var.isIndirect() && "indirect address for piece");
2103 unsigned VarSize = Var.getSizeInBits(Map);
2104 assert(PieceSize+PieceOffset <= VarSize/SizeOfByte
2105 && "piece is larger than or outside of variable");
2106 assert(PieceSize*SizeOfByte != VarSize
2107 && "piece covers entire variable");
2109 if (Piece.isLocation() && Piece.getLoc().isReg())
2110 Asm->EmitDwarfRegOpPiece(Streamer,
2112 PieceSize*SizeOfByte);
2114 emitDebugLocValue(Streamer, Piece);
2115 Asm->EmitDwarfOpPiece(Streamer, PieceSize*SizeOfByte);
2121 void DwarfDebug::emitDebugLocEntry(ByteStreamer &Streamer,
2122 const DebugLocEntry &Entry) {
2123 const DebugLocEntry::Value Value = Entry.getValues()[0];
2124 DIVariable DV(Value.getVariable());
2125 if (DV.isVariablePiece())
2126 // Emit all pieces that belong to the same variable and range.
2127 return emitLocPieces(Streamer, TypeIdentifierMap, Entry.getValues());
2129 assert(Entry.getValues().size() == 1 && "only pieces may have >1 value");
2130 emitDebugLocValue(Streamer, Value);
2133 void DwarfDebug::emitDebugLocValue(ByteStreamer &Streamer,
2134 const DebugLocEntry::Value &Value) {
2135 DIVariable DV(Value.getVariable());
2137 if (Value.isInt()) {
2138 DIBasicType BTy(resolve(DV.getType()));
2139 if (BTy.Verify() && (BTy.getEncoding() == dwarf::DW_ATE_signed ||
2140 BTy.getEncoding() == dwarf::DW_ATE_signed_char)) {
2141 Streamer.EmitInt8(dwarf::DW_OP_consts, "DW_OP_consts");
2142 Streamer.EmitSLEB128(Value.getInt());
2144 Streamer.EmitInt8(dwarf::DW_OP_constu, "DW_OP_constu");
2145 Streamer.EmitULEB128(Value.getInt());
2147 } else if (Value.isLocation()) {
2148 MachineLocation Loc = Value.getLoc();
2149 if (!DV.hasComplexAddress())
2151 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2153 // Complex address entry.
2154 unsigned N = DV.getNumAddrElements();
2156 if (N >= 2 && DV.getAddrElement(0) == DIBuilder::OpPlus) {
2157 if (Loc.getOffset()) {
2159 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2160 Streamer.EmitInt8(dwarf::DW_OP_deref, "DW_OP_deref");
2161 Streamer.EmitInt8(dwarf::DW_OP_plus_uconst, "DW_OP_plus_uconst");
2162 Streamer.EmitSLEB128(DV.getAddrElement(1));
2164 // If first address element is OpPlus then emit
2165 // DW_OP_breg + Offset instead of DW_OP_reg + Offset.
2166 MachineLocation TLoc(Loc.getReg(), DV.getAddrElement(1));
2167 Asm->EmitDwarfRegOp(Streamer, TLoc, DV.isIndirect());
2171 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2174 // Emit remaining complex address elements.
2175 for (; i < N; ++i) {
2176 uint64_t Element = DV.getAddrElement(i);
2177 if (Element == DIBuilder::OpPlus) {
2178 Streamer.EmitInt8(dwarf::DW_OP_plus_uconst, "DW_OP_plus_uconst");
2179 Streamer.EmitULEB128(DV.getAddrElement(++i));
2180 } else if (Element == DIBuilder::OpDeref) {
2182 Streamer.EmitInt8(dwarf::DW_OP_deref, "DW_OP_deref");
2183 } else if (Element == DIBuilder::OpPiece) {
2185 // handled in emitDebugLocEntry.
2187 llvm_unreachable("unknown Opcode found in complex address");
2191 // else ... ignore constant fp. There is not any good way to
2192 // to represent them here in dwarf.
2196 void DwarfDebug::emitDebugLocEntryLocation(const DebugLocEntry &Entry) {
2197 Asm->OutStreamer.AddComment("Loc expr size");
2198 MCSymbol *begin = Asm->OutStreamer.getContext().CreateTempSymbol();
2199 MCSymbol *end = Asm->OutStreamer.getContext().CreateTempSymbol();
2200 Asm->EmitLabelDifference(end, begin, 2);
2201 Asm->OutStreamer.EmitLabel(begin);
2203 APByteStreamer Streamer(*Asm);
2204 emitDebugLocEntry(Streamer, Entry);
2206 Asm->OutStreamer.EmitLabel(end);
2209 // Emit locations into the debug loc section.
2210 void DwarfDebug::emitDebugLoc() {
2211 // Start the dwarf loc section.
2212 Asm->OutStreamer.SwitchSection(
2213 Asm->getObjFileLowering().getDwarfLocSection());
2214 unsigned char Size = Asm->getDataLayout().getPointerSize();
2215 for (const auto &DebugLoc : DotDebugLocEntries) {
2216 Asm->OutStreamer.EmitLabel(DebugLoc.Label);
2217 const DwarfCompileUnit *CU = DebugLoc.CU;
2218 assert(!CU->getRanges().empty());
2219 for (const auto &Entry : DebugLoc.List) {
2220 // Set up the range. This range is relative to the entry point of the
2221 // compile unit. This is a hard coded 0 for low_pc when we're emitting
2222 // ranges, or the DW_AT_low_pc on the compile unit otherwise.
2223 if (CU->getRanges().size() == 1) {
2224 // Grab the begin symbol from the first range as our base.
2225 const MCSymbol *Base = CU->getRanges()[0].getStart();
2226 Asm->EmitLabelDifference(Entry.getBeginSym(), Base, Size);
2227 Asm->EmitLabelDifference(Entry.getEndSym(), Base, Size);
2229 Asm->OutStreamer.EmitSymbolValue(Entry.getBeginSym(), Size);
2230 Asm->OutStreamer.EmitSymbolValue(Entry.getEndSym(), Size);
2233 emitDebugLocEntryLocation(Entry);
2235 Asm->OutStreamer.EmitIntValue(0, Size);
2236 Asm->OutStreamer.EmitIntValue(0, Size);
2240 void DwarfDebug::emitDebugLocDWO() {
2241 Asm->OutStreamer.SwitchSection(
2242 Asm->getObjFileLowering().getDwarfLocDWOSection());
2243 for (const auto &DebugLoc : DotDebugLocEntries) {
2244 Asm->OutStreamer.EmitLabel(DebugLoc.Label);
2245 for (const auto &Entry : DebugLoc.List) {
2246 // Just always use start_length for now - at least that's one address
2247 // rather than two. We could get fancier and try to, say, reuse an
2248 // address we know we've emitted elsewhere (the start of the function?
2249 // The start of the CU or CU subrange that encloses this range?)
2250 Asm->EmitInt8(dwarf::DW_LLE_start_length_entry);
2251 unsigned idx = AddrPool.getIndex(Entry.getBeginSym());
2252 Asm->EmitULEB128(idx);
2253 Asm->EmitLabelDifference(Entry.getEndSym(), Entry.getBeginSym(), 4);
2255 emitDebugLocEntryLocation(Entry);
2257 Asm->EmitInt8(dwarf::DW_LLE_end_of_list_entry);
2262 const MCSymbol *Start, *End;
2265 // Emit a debug aranges section, containing a CU lookup for any
2266 // address we can tie back to a CU.
2267 void DwarfDebug::emitDebugARanges() {
2268 // Start the dwarf aranges section.
2269 Asm->OutStreamer.SwitchSection(
2270 Asm->getObjFileLowering().getDwarfARangesSection());
2272 typedef DenseMap<DwarfCompileUnit *, std::vector<ArangeSpan>> SpansType;
2276 // Build a list of sections used.
2277 std::vector<const MCSection *> Sections;
2278 for (const auto &it : SectionMap) {
2279 const MCSection *Section = it.first;
2280 Sections.push_back(Section);
2283 // Sort the sections into order.
2284 // This is only done to ensure consistent output order across different runs.
2285 std::sort(Sections.begin(), Sections.end(), SectionSort);
2287 // Build a set of address spans, sorted by CU.
2288 for (const MCSection *Section : Sections) {
2289 SmallVector<SymbolCU, 8> &List = SectionMap[Section];
2290 if (List.size() < 2)
2293 // Sort the symbols by offset within the section.
2294 std::sort(List.begin(), List.end(),
2295 [&](const SymbolCU &A, const SymbolCU &B) {
2296 unsigned IA = A.Sym ? Asm->OutStreamer.GetSymbolOrder(A.Sym) : 0;
2297 unsigned IB = B.Sym ? Asm->OutStreamer.GetSymbolOrder(B.Sym) : 0;
2299 // Symbols with no order assigned should be placed at the end.
2300 // (e.g. section end labels)
2308 // If we have no section (e.g. common), just write out
2309 // individual spans for each symbol.
2311 for (const SymbolCU &Cur : List) {
2313 Span.Start = Cur.Sym;
2316 Spans[Cur.CU].push_back(Span);
2319 // Build spans between each label.
2320 const MCSymbol *StartSym = List[0].Sym;
2321 for (size_t n = 1, e = List.size(); n < e; n++) {
2322 const SymbolCU &Prev = List[n - 1];
2323 const SymbolCU &Cur = List[n];
2325 // Try and build the longest span we can within the same CU.
2326 if (Cur.CU != Prev.CU) {
2328 Span.Start = StartSym;
2330 Spans[Prev.CU].push_back(Span);
2337 unsigned PtrSize = Asm->getDataLayout().getPointerSize();
2339 // Build a list of CUs used.
2340 std::vector<DwarfCompileUnit *> CUs;
2341 for (const auto &it : Spans) {
2342 DwarfCompileUnit *CU = it.first;
2346 // Sort the CU list (again, to ensure consistent output order).
2347 std::sort(CUs.begin(), CUs.end(), [](const DwarfUnit *A, const DwarfUnit *B) {
2348 return A->getUniqueID() < B->getUniqueID();
2351 // Emit an arange table for each CU we used.
2352 for (DwarfCompileUnit *CU : CUs) {
2353 std::vector<ArangeSpan> &List = Spans[CU];
2355 // Emit size of content not including length itself.
2356 unsigned ContentSize =
2357 sizeof(int16_t) + // DWARF ARange version number
2358 sizeof(int32_t) + // Offset of CU in the .debug_info section
2359 sizeof(int8_t) + // Pointer Size (in bytes)
2360 sizeof(int8_t); // Segment Size (in bytes)
2362 unsigned TupleSize = PtrSize * 2;
2364 // 7.20 in the Dwarf specs requires the table to be aligned to a tuple.
2366 OffsetToAlignment(sizeof(int32_t) + ContentSize, TupleSize);
2368 ContentSize += Padding;
2369 ContentSize += (List.size() + 1) * TupleSize;
2371 // For each compile unit, write the list of spans it covers.
2372 Asm->OutStreamer.AddComment("Length of ARange Set");
2373 Asm->EmitInt32(ContentSize);
2374 Asm->OutStreamer.AddComment("DWARF Arange version number");
2375 Asm->EmitInt16(dwarf::DW_ARANGES_VERSION);
2376 Asm->OutStreamer.AddComment("Offset Into Debug Info Section");
2377 Asm->EmitSectionOffset(CU->getLocalLabelBegin(), CU->getLocalSectionSym());
2378 Asm->OutStreamer.AddComment("Address Size (in bytes)");
2379 Asm->EmitInt8(PtrSize);
2380 Asm->OutStreamer.AddComment("Segment Size (in bytes)");
2383 Asm->OutStreamer.EmitFill(Padding, 0xff);
2385 for (const ArangeSpan &Span : List) {
2386 Asm->EmitLabelReference(Span.Start, PtrSize);
2388 // Calculate the size as being from the span start to it's end.
2390 Asm->EmitLabelDifference(Span.End, Span.Start, PtrSize);
2392 // For symbols without an end marker (e.g. common), we
2393 // write a single arange entry containing just that one symbol.
2394 uint64_t Size = SymSize[Span.Start];
2398 Asm->OutStreamer.EmitIntValue(Size, PtrSize);
2402 Asm->OutStreamer.AddComment("ARange terminator");
2403 Asm->OutStreamer.EmitIntValue(0, PtrSize);
2404 Asm->OutStreamer.EmitIntValue(0, PtrSize);
2408 // Emit visible names into a debug ranges section.
2409 void DwarfDebug::emitDebugRanges() {
2410 // Start the dwarf ranges section.
2411 Asm->OutStreamer.SwitchSection(
2412 Asm->getObjFileLowering().getDwarfRangesSection());
2414 // Size for our labels.
2415 unsigned char Size = Asm->getDataLayout().getPointerSize();
2417 // Grab the specific ranges for the compile units in the module.
2418 for (const auto &I : CUMap) {
2419 DwarfCompileUnit *TheCU = I.second;
2421 // Iterate over the misc ranges for the compile units in the module.
2422 for (const RangeSpanList &List : TheCU->getRangeLists()) {
2423 // Emit our symbol so we can find the beginning of the range.
2424 Asm->OutStreamer.EmitLabel(List.getSym());
2426 for (const RangeSpan &Range : List.getRanges()) {
2427 const MCSymbol *Begin = Range.getStart();
2428 const MCSymbol *End = Range.getEnd();
2429 assert(Begin && "Range without a begin symbol?");
2430 assert(End && "Range without an end symbol?");
2431 if (TheCU->getRanges().size() == 1) {
2432 // Grab the begin symbol from the first range as our base.
2433 const MCSymbol *Base = TheCU->getRanges()[0].getStart();
2434 Asm->EmitLabelDifference(Begin, Base, Size);
2435 Asm->EmitLabelDifference(End, Base, Size);
2437 Asm->OutStreamer.EmitSymbolValue(Begin, Size);
2438 Asm->OutStreamer.EmitSymbolValue(End, Size);
2442 // And terminate the list with two 0 values.
2443 Asm->OutStreamer.EmitIntValue(0, Size);
2444 Asm->OutStreamer.EmitIntValue(0, Size);
2447 // Now emit a range for the CU itself.
2448 if (TheCU->getRanges().size() > 1) {
2449 Asm->OutStreamer.EmitLabel(
2450 Asm->GetTempSymbol("cu_ranges", TheCU->getUniqueID()));
2451 for (const RangeSpan &Range : TheCU->getRanges()) {
2452 const MCSymbol *Begin = Range.getStart();
2453 const MCSymbol *End = Range.getEnd();
2454 assert(Begin && "Range without a begin symbol?");
2455 assert(End && "Range without an end symbol?");
2456 Asm->OutStreamer.EmitSymbolValue(Begin, Size);
2457 Asm->OutStreamer.EmitSymbolValue(End, Size);
2459 // And terminate the list with two 0 values.
2460 Asm->OutStreamer.EmitIntValue(0, Size);
2461 Asm->OutStreamer.EmitIntValue(0, Size);
2466 // DWARF5 Experimental Separate Dwarf emitters.
2468 void DwarfDebug::initSkeletonUnit(const DwarfUnit &U, DIE &Die,
2469 std::unique_ptr<DwarfUnit> NewU) {
2470 NewU->addLocalString(Die, dwarf::DW_AT_GNU_dwo_name,
2471 U.getCUNode().getSplitDebugFilename());
2473 if (!CompilationDir.empty())
2474 NewU->addLocalString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
2476 addGnuPubAttributes(*NewU, Die);
2478 SkeletonHolder.addUnit(std::move(NewU));
2481 // This DIE has the following attributes: DW_AT_comp_dir, DW_AT_stmt_list,
2482 // DW_AT_low_pc, DW_AT_high_pc, DW_AT_ranges, DW_AT_dwo_name, DW_AT_dwo_id,
2483 // DW_AT_addr_base, DW_AT_ranges_base.
2484 DwarfCompileUnit &DwarfDebug::constructSkeletonCU(const DwarfCompileUnit &CU) {
2486 auto OwnedUnit = make_unique<DwarfCompileUnit>(
2487 CU.getUniqueID(), CU.getCUNode(), Asm, this, &SkeletonHolder);
2488 DwarfCompileUnit &NewCU = *OwnedUnit;
2489 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoSection(),
2490 DwarfInfoSectionSym);
2492 NewCU.initStmtList(DwarfLineSectionSym);
2494 initSkeletonUnit(CU, NewCU.getUnitDie(), std::move(OwnedUnit));
2499 // This DIE has the following attributes: DW_AT_comp_dir, DW_AT_dwo_name,
2501 DwarfTypeUnit &DwarfDebug::constructSkeletonTU(DwarfTypeUnit &TU) {
2502 DwarfCompileUnit &CU = static_cast<DwarfCompileUnit &>(
2503 *SkeletonHolder.getUnits()[TU.getCU().getUniqueID()]);
2505 auto OwnedUnit = make_unique<DwarfTypeUnit>(TU.getUniqueID(), CU, Asm, this,
2507 DwarfTypeUnit &NewTU = *OwnedUnit;
2508 NewTU.setTypeSignature(TU.getTypeSignature());
2509 NewTU.setType(nullptr);
2511 Asm->getObjFileLowering().getDwarfTypesSection(TU.getTypeSignature()));
2513 initSkeletonUnit(TU, NewTU.getUnitDie(), std::move(OwnedUnit));
2517 // Emit the .debug_info.dwo section for separated dwarf. This contains the
2518 // compile units that would normally be in debug_info.
2519 void DwarfDebug::emitDebugInfoDWO() {
2520 assert(useSplitDwarf() && "No split dwarf debug info?");
2521 // Don't pass an abbrev symbol, using a constant zero instead so as not to
2522 // emit relocations into the dwo file.
2523 InfoHolder.emitUnits(this, /* AbbrevSymbol */ nullptr);
2526 // Emit the .debug_abbrev.dwo section for separated dwarf. This contains the
2527 // abbreviations for the .debug_info.dwo section.
2528 void DwarfDebug::emitDebugAbbrevDWO() {
2529 assert(useSplitDwarf() && "No split dwarf?");
2530 InfoHolder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevDWOSection());
2533 void DwarfDebug::emitDebugLineDWO() {
2534 assert(useSplitDwarf() && "No split dwarf?");
2535 Asm->OutStreamer.SwitchSection(
2536 Asm->getObjFileLowering().getDwarfLineDWOSection());
2537 SplitTypeUnitFileTable.Emit(Asm->OutStreamer);
2540 // Emit the .debug_str.dwo section for separated dwarf. This contains the
2541 // string section and is identical in format to traditional .debug_str
2543 void DwarfDebug::emitDebugStrDWO() {
2544 assert(useSplitDwarf() && "No split dwarf?");
2545 const MCSection *OffSec =
2546 Asm->getObjFileLowering().getDwarfStrOffDWOSection();
2547 const MCSymbol *StrSym = DwarfStrSectionSym;
2548 InfoHolder.emitStrings(Asm->getObjFileLowering().getDwarfStrDWOSection(),
2552 MCDwarfDwoLineTable *DwarfDebug::getDwoLineTable(const DwarfCompileUnit &CU) {
2553 if (!useSplitDwarf())
2556 SplitTypeUnitFileTable.setCompilationDir(CU.getCUNode().getDirectory());
2557 return &SplitTypeUnitFileTable;
2560 static uint64_t makeTypeSignature(StringRef Identifier) {
2562 Hash.update(Identifier);
2563 // ... take the least significant 8 bytes and return those. Our MD5
2564 // implementation always returns its results in little endian, swap bytes
2566 MD5::MD5Result Result;
2568 return *reinterpret_cast<support::ulittle64_t *>(Result + 8);
2571 void DwarfDebug::addDwarfTypeUnitType(DwarfCompileUnit &CU,
2572 StringRef Identifier, DIE &RefDie,
2573 DICompositeType CTy) {
2574 // Fast path if we're building some type units and one has already used the
2575 // address pool we know we're going to throw away all this work anyway, so
2576 // don't bother building dependent types.
2577 if (!TypeUnitsUnderConstruction.empty() && AddrPool.hasBeenUsed())
2580 const DwarfTypeUnit *&TU = DwarfTypeUnits[CTy];
2582 CU.addDIETypeSignature(RefDie, *TU);
2586 bool TopLevelType = TypeUnitsUnderConstruction.empty();
2587 AddrPool.resetUsedFlag();
2589 auto OwnedUnit = make_unique<DwarfTypeUnit>(
2590 InfoHolder.getUnits().size() + TypeUnitsUnderConstruction.size(), CU, Asm,
2591 this, &InfoHolder, getDwoLineTable(CU));
2592 DwarfTypeUnit &NewTU = *OwnedUnit;
2593 DIE &UnitDie = NewTU.getUnitDie();
2595 TypeUnitsUnderConstruction.push_back(
2596 std::make_pair(std::move(OwnedUnit), CTy));
2598 NewTU.addUInt(UnitDie, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
2601 uint64_t Signature = makeTypeSignature(Identifier);
2602 NewTU.setTypeSignature(Signature);
2604 if (useSplitDwarf())
2605 NewTU.initSection(Asm->getObjFileLowering().getDwarfTypesDWOSection(),
2606 DwarfTypesDWOSectionSym);
2608 CU.applyStmtList(UnitDie);
2610 Asm->getObjFileLowering().getDwarfTypesSection(Signature));
2613 NewTU.setType(NewTU.createTypeDIE(CTy));
2616 auto TypeUnitsToAdd = std::move(TypeUnitsUnderConstruction);
2617 TypeUnitsUnderConstruction.clear();
2619 // Types referencing entries in the address table cannot be placed in type
2621 if (AddrPool.hasBeenUsed()) {
2623 // Remove all the types built while building this type.
2624 // This is pessimistic as some of these types might not be dependent on
2625 // the type that used an address.
2626 for (const auto &TU : TypeUnitsToAdd)
2627 DwarfTypeUnits.erase(TU.second);
2629 // Construct this type in the CU directly.
2630 // This is inefficient because all the dependent types will be rebuilt
2631 // from scratch, including building them in type units, discovering that
2632 // they depend on addresses, throwing them out and rebuilding them.
2633 CU.constructTypeDIE(RefDie, CTy);
2637 // If the type wasn't dependent on fission addresses, finish adding the type
2638 // and all its dependent types.
2639 for (auto &TU : TypeUnitsToAdd) {
2640 if (useSplitDwarf())
2641 TU.first->setSkeleton(constructSkeletonTU(*TU.first));
2642 InfoHolder.addUnit(std::move(TU.first));
2645 CU.addDIETypeSignature(RefDie, NewTU);
2648 void DwarfDebug::attachLowHighPC(DwarfCompileUnit &Unit, DIE &D,
2649 MCSymbol *Begin, MCSymbol *End) {
2650 assert(Begin && "Begin label should not be null!");
2651 assert(End && "End label should not be null!");
2652 assert(Begin->isDefined() && "Invalid starting label");
2653 assert(End->isDefined() && "Invalid end label");
2655 Unit.addLabelAddress(D, dwarf::DW_AT_low_pc, Begin);
2656 if (DwarfVersion < 4)
2657 Unit.addLabelAddress(D, dwarf::DW_AT_high_pc, End);
2659 Unit.addLabelDelta(D, dwarf::DW_AT_high_pc, End, Begin);
2662 // Accelerator table mutators - add each name along with its companion
2663 // DIE to the proper table while ensuring that the name that we're going
2664 // to reference is in the string table. We do this since the names we
2665 // add may not only be identical to the names in the DIE.
2666 void DwarfDebug::addAccelName(StringRef Name, const DIE &Die) {
2667 if (!useDwarfAccelTables())
2669 AccelNames.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2673 void DwarfDebug::addAccelObjC(StringRef Name, const DIE &Die) {
2674 if (!useDwarfAccelTables())
2676 AccelObjC.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2680 void DwarfDebug::addAccelNamespace(StringRef Name, const DIE &Die) {
2681 if (!useDwarfAccelTables())
2683 AccelNamespace.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2687 void DwarfDebug::addAccelType(StringRef Name, const DIE &Die, char Flags) {
2688 if (!useDwarfAccelTables())
2690 AccelTypes.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),