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.
801 // FIXME: Consider the time-space tradeoff of just storing the unit pointer
802 // in the ConcreteVariables list, rather than looking it up again here.
803 // DIE::getUnit isn't simple - it walks parent pointers, etc.
804 DwarfCompileUnit *Unit = lookupUnit(VariableDie->getUnit());
806 DbgVariable *AbsVar = getExistingAbstractVariable(Var->getVariable());
807 if (AbsVar && AbsVar->getDIE()) {
808 Unit->addDIEEntry(*VariableDie, dwarf::DW_AT_abstract_origin,
811 Unit->applyVariableAttributes(*Var, *VariableDie);
815 void DwarfDebug::finishSubprogramDefinitions() {
816 const Module *M = MMI->getModule();
818 NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
819 for (MDNode *N : CU_Nodes->operands()) {
820 DICompileUnit TheCU(N);
821 // Construct subprogram DIE and add variables DIEs.
822 DwarfCompileUnit *SPCU =
823 static_cast<DwarfCompileUnit *>(CUMap.lookup(TheCU));
824 DIArray Subprograms = TheCU.getSubprograms();
825 for (unsigned i = 0, e = Subprograms.getNumElements(); i != e; ++i) {
826 DISubprogram SP(Subprograms.getElement(i));
827 // Perhaps the subprogram is in another CU (such as due to comdat
828 // folding, etc), in which case ignore it here.
829 if (SPMap[SP] != SPCU)
831 DIE *D = SPCU->getDIE(SP);
832 if (DIE *AbsSPDIE = AbstractSPDies.lookup(SP)) {
834 // If this subprogram has an abstract definition, reference that
835 SPCU->addDIEEntry(*D, dwarf::DW_AT_abstract_origin, *AbsSPDIE);
838 // Lazily construct the subprogram if we didn't see either concrete or
839 // inlined versions during codegen.
840 D = SPCU->getOrCreateSubprogramDIE(SP);
841 // And attach the attributes
842 SPCU->applySubprogramAttributesToDefinition(SP, *D);
849 // Collect info for variables that were optimized out.
850 void DwarfDebug::collectDeadVariables() {
851 const Module *M = MMI->getModule();
853 if (NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu")) {
854 for (MDNode *N : CU_Nodes->operands()) {
855 DICompileUnit TheCU(N);
856 // Construct subprogram DIE and add variables DIEs.
857 DwarfCompileUnit *SPCU =
858 static_cast<DwarfCompileUnit *>(CUMap.lookup(TheCU));
859 assert(SPCU && "Unable to find Compile Unit!");
860 DIArray Subprograms = TheCU.getSubprograms();
861 for (unsigned i = 0, e = Subprograms.getNumElements(); i != e; ++i) {
862 DISubprogram SP(Subprograms.getElement(i));
863 if (ProcessedSPNodes.count(SP) != 0)
865 assert(SP.isSubprogram() &&
866 "CU's subprogram list contains a non-subprogram");
867 assert(SP.isDefinition() &&
868 "CU's subprogram list contains a subprogram declaration");
869 DIArray Variables = SP.getVariables();
870 if (Variables.getNumElements() == 0)
873 DIE *SPDIE = AbstractSPDies.lookup(SP);
875 SPDIE = SPCU->getDIE(SP);
877 for (unsigned vi = 0, ve = Variables.getNumElements(); vi != ve; ++vi) {
878 DIVariable DV(Variables.getElement(vi));
879 assert(DV.isVariable());
880 DbgVariable NewVar(DV, this);
881 auto VariableDie = SPCU->constructVariableDIE(NewVar);
882 SPCU->applyVariableAttributes(NewVar, *VariableDie);
883 SPDIE->addChild(std::move(VariableDie));
890 void DwarfDebug::finalizeModuleInfo() {
891 finishSubprogramDefinitions();
893 finishVariableDefinitions();
895 // Collect info for variables that were optimized out.
896 collectDeadVariables();
898 // Handle anything that needs to be done on a per-unit basis after
899 // all other generation.
900 for (const auto &TheU : getUnits()) {
901 // Emit DW_AT_containing_type attribute to connect types with their
902 // vtable holding type.
903 TheU->constructContainingTypeDIEs();
905 // Add CU specific attributes if we need to add any.
906 if (TheU->getUnitDie().getTag() == dwarf::DW_TAG_compile_unit) {
907 // If we're splitting the dwarf out now that we've got the entire
908 // CU then add the dwo id to it.
909 DwarfCompileUnit *SkCU =
910 static_cast<DwarfCompileUnit *>(TheU->getSkeleton());
911 if (useSplitDwarf()) {
912 // Emit a unique identifier for this CU.
913 uint64_t ID = DIEHash(Asm).computeCUSignature(TheU->getUnitDie());
914 TheU->addUInt(TheU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
915 dwarf::DW_FORM_data8, ID);
916 SkCU->addUInt(SkCU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
917 dwarf::DW_FORM_data8, ID);
919 // We don't keep track of which addresses are used in which CU so this
920 // is a bit pessimistic under LTO.
921 if (!AddrPool.isEmpty())
922 addSectionLabel(*Asm, *SkCU, SkCU->getUnitDie(),
923 dwarf::DW_AT_GNU_addr_base, DwarfAddrSectionSym,
924 DwarfAddrSectionSym);
925 if (!TheU->getRangeLists().empty())
926 addSectionLabel(*Asm, *SkCU, SkCU->getUnitDie(),
927 dwarf::DW_AT_GNU_ranges_base,
928 DwarfDebugRangeSectionSym, DwarfDebugRangeSectionSym);
931 // If we have code split among multiple sections or non-contiguous
932 // ranges of code then emit a DW_AT_ranges attribute on the unit that will
933 // remain in the .o file, otherwise add a DW_AT_low_pc.
934 // FIXME: We should use ranges allow reordering of code ala
935 // .subsections_via_symbols in mach-o. This would mean turning on
936 // ranges for all subprogram DIEs for mach-o.
937 DwarfCompileUnit &U =
938 SkCU ? *SkCU : static_cast<DwarfCompileUnit &>(*TheU);
939 unsigned NumRanges = TheU->getRanges().size();
942 addSectionLabel(*Asm, U, U.getUnitDie(), dwarf::DW_AT_ranges,
943 Asm->GetTempSymbol("cu_ranges", U.getUniqueID()),
944 DwarfDebugRangeSectionSym);
946 // A DW_AT_low_pc attribute may also be specified in combination with
947 // DW_AT_ranges to specify the default base address for use in
948 // location lists (see Section 2.6.2) and range lists (see Section
950 U.addUInt(U.getUnitDie(), dwarf::DW_AT_low_pc, dwarf::DW_FORM_addr,
953 RangeSpan &Range = TheU->getRanges().back();
954 U.addLocalLabelAddress(U.getUnitDie(), dwarf::DW_AT_low_pc,
956 U.addLabelDelta(U.getUnitDie(), dwarf::DW_AT_high_pc, Range.getEnd(),
963 // Compute DIE offsets and sizes.
964 InfoHolder.computeSizeAndOffsets();
966 SkeletonHolder.computeSizeAndOffsets();
969 void DwarfDebug::endSections() {
970 // Filter labels by section.
971 for (const SymbolCU &SCU : ArangeLabels) {
972 if (SCU.Sym->isInSection()) {
973 // Make a note of this symbol and it's section.
974 const MCSection *Section = &SCU.Sym->getSection();
975 if (!Section->getKind().isMetadata())
976 SectionMap[Section].push_back(SCU);
978 // Some symbols (e.g. common/bss on mach-o) can have no section but still
979 // appear in the output. This sucks as we rely on sections to build
980 // arange spans. We can do it without, but it's icky.
981 SectionMap[nullptr].push_back(SCU);
985 // Build a list of sections used.
986 std::vector<const MCSection *> Sections;
987 for (const auto &it : SectionMap) {
988 const MCSection *Section = it.first;
989 Sections.push_back(Section);
992 // Sort the sections into order.
993 // This is only done to ensure consistent output order across different runs.
994 std::sort(Sections.begin(), Sections.end(), SectionSort);
996 // Add terminating symbols for each section.
997 for (unsigned ID = 0, E = Sections.size(); ID != E; ID++) {
998 const MCSection *Section = Sections[ID];
999 MCSymbol *Sym = nullptr;
1002 // We can't call MCSection::getLabelEndName, as it's only safe to do so
1003 // if we know the section name up-front. For user-created sections, the
1004 // resulting label may not be valid to use as a label. (section names can
1005 // use a greater set of characters on some systems)
1006 Sym = Asm->GetTempSymbol("debug_end", ID);
1007 Asm->OutStreamer.SwitchSection(Section);
1008 Asm->OutStreamer.EmitLabel(Sym);
1011 // Insert a final terminator.
1012 SectionMap[Section].push_back(SymbolCU(nullptr, Sym));
1016 // Emit all Dwarf sections that should come after the content.
1017 void DwarfDebug::endModule() {
1018 assert(CurFn == nullptr);
1019 assert(CurMI == nullptr);
1024 // End any existing sections.
1025 // TODO: Does this need to happen?
1028 // Finalize the debug info for the module.
1029 finalizeModuleInfo();
1033 // Emit all the DIEs into a debug info section.
1036 // Corresponding abbreviations into a abbrev section.
1037 emitAbbreviations();
1039 // Emit info into a debug aranges section.
1040 if (GenerateARangeSection)
1043 // Emit info into a debug ranges section.
1046 if (useSplitDwarf()) {
1049 emitDebugAbbrevDWO();
1052 // Emit DWO addresses.
1053 AddrPool.emit(*Asm, Asm->getObjFileLowering().getDwarfAddrSection());
1055 // Emit info into a debug loc section.
1058 // Emit info into the dwarf accelerator table sections.
1059 if (useDwarfAccelTables()) {
1062 emitAccelNamespaces();
1066 // Emit the pubnames and pubtypes sections if requested.
1067 if (HasDwarfPubSections) {
1068 emitDebugPubNames(GenerateGnuPubSections);
1069 emitDebugPubTypes(GenerateGnuPubSections);
1074 AbstractVariables.clear();
1076 // Reset these for the next Module if we have one.
1080 // Find abstract variable, if any, associated with Var.
1081 DbgVariable *DwarfDebug::getExistingAbstractVariable(const DIVariable &DV,
1082 DIVariable &Cleansed) {
1083 LLVMContext &Ctx = DV->getContext();
1084 // More then one inlined variable corresponds to one abstract variable.
1085 // FIXME: This duplication of variables when inlining should probably be
1086 // removed. It's done to allow each DIVariable to describe its location
1087 // because the DebugLoc on the dbg.value/declare isn't accurate. We should
1088 // make it accurate then remove this duplication/cleansing stuff.
1089 Cleansed = cleanseInlinedVariable(DV, Ctx);
1090 auto I = AbstractVariables.find(Cleansed);
1091 if (I != AbstractVariables.end())
1092 return I->second.get();
1096 DbgVariable *DwarfDebug::getExistingAbstractVariable(const DIVariable &DV) {
1097 DIVariable Cleansed;
1098 return getExistingAbstractVariable(DV, Cleansed);
1101 void DwarfDebug::createAbstractVariable(const DIVariable &Var,
1102 LexicalScope *Scope) {
1103 auto AbsDbgVariable = make_unique<DbgVariable>(Var, this);
1104 addScopeVariable(Scope, AbsDbgVariable.get());
1105 AbstractVariables[Var] = std::move(AbsDbgVariable);
1108 void DwarfDebug::ensureAbstractVariableIsCreated(const DIVariable &DV,
1109 const MDNode *ScopeNode) {
1110 DIVariable Cleansed = DV;
1111 if (getExistingAbstractVariable(DV, Cleansed))
1114 createAbstractVariable(Cleansed, LScopes.getOrCreateAbstractScope(ScopeNode));
1118 DwarfDebug::ensureAbstractVariableIsCreatedIfScoped(const DIVariable &DV,
1119 const MDNode *ScopeNode) {
1120 DIVariable Cleansed = DV;
1121 if (getExistingAbstractVariable(DV, Cleansed))
1124 if (LexicalScope *Scope = LScopes.findAbstractScope(ScopeNode))
1125 createAbstractVariable(Cleansed, Scope);
1128 // If Var is a current function argument then add it to CurrentFnArguments list.
1129 bool DwarfDebug::addCurrentFnArgument(DbgVariable *Var, LexicalScope *Scope) {
1130 if (!LScopes.isCurrentFunctionScope(Scope))
1132 DIVariable DV = Var->getVariable();
1133 if (DV.getTag() != dwarf::DW_TAG_arg_variable)
1135 unsigned ArgNo = DV.getArgNumber();
1139 size_t Size = CurrentFnArguments.size();
1141 CurrentFnArguments.resize(CurFn->getFunction()->arg_size());
1142 // llvm::Function argument size is not good indicator of how many
1143 // arguments does the function have at source level.
1145 CurrentFnArguments.resize(ArgNo * 2);
1146 CurrentFnArguments[ArgNo - 1] = Var;
1150 // Collect variable information from side table maintained by MMI.
1151 void DwarfDebug::collectVariableInfoFromMMITable(
1152 SmallPtrSet<const MDNode *, 16> &Processed) {
1153 for (const auto &VI : MMI->getVariableDbgInfo()) {
1156 Processed.insert(VI.Var);
1157 DIVariable DV(VI.Var);
1158 LexicalScope *Scope = LScopes.findLexicalScope(VI.Loc);
1160 // If variable scope is not found then skip this variable.
1164 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
1165 ConcreteVariables.push_back(make_unique<DbgVariable>(DV, this));
1166 DbgVariable *RegVar = ConcreteVariables.back().get();
1167 RegVar->setFrameIndex(VI.Slot);
1168 addScopeVariable(Scope, RegVar);
1172 // Get .debug_loc entry for the instruction range starting at MI.
1173 static DebugLocEntry::Value getDebugLocValue(const MachineInstr *MI) {
1174 const MDNode *Var = MI->getDebugVariable();
1176 assert(MI->getNumOperands() == 3);
1177 if (MI->getOperand(0).isReg()) {
1178 MachineLocation MLoc;
1179 // If the second operand is an immediate, this is a
1180 // register-indirect address.
1181 if (!MI->getOperand(1).isImm())
1182 MLoc.set(MI->getOperand(0).getReg());
1184 MLoc.set(MI->getOperand(0).getReg(), MI->getOperand(1).getImm());
1185 return DebugLocEntry::Value(Var, MLoc);
1187 if (MI->getOperand(0).isImm())
1188 return DebugLocEntry::Value(Var, MI->getOperand(0).getImm());
1189 if (MI->getOperand(0).isFPImm())
1190 return DebugLocEntry::Value(Var, MI->getOperand(0).getFPImm());
1191 if (MI->getOperand(0).isCImm())
1192 return DebugLocEntry::Value(Var, MI->getOperand(0).getCImm());
1194 llvm_unreachable("Unexpected 3 operand DBG_VALUE instruction!");
1197 /// Determine whether two variable pieces overlap.
1198 static bool piecesOverlap(DIVariable P1, DIVariable P2) {
1199 if (!P1.isVariablePiece() || !P2.isVariablePiece())
1201 unsigned l1 = P1.getPieceOffset();
1202 unsigned l2 = P2.getPieceOffset();
1203 unsigned r1 = l1 + P1.getPieceSize();
1204 unsigned r2 = l2 + P2.getPieceSize();
1205 // True where [l1,r1[ and [r1,r2[ overlap.
1206 return (l1 < r2) && (l2 < r1);
1209 /// Build the location list for all DBG_VALUEs in the function that
1210 /// describe the same variable. If the ranges of several independent
1211 /// pieces of the same variable overlap partially, split them up and
1212 /// combine the ranges. The resulting DebugLocEntries are will have
1213 /// strict monotonically increasing begin addresses and will never
1218 // Ranges History [var, loc, piece ofs size]
1219 // 0 | [x, (reg0, piece 0, 32)]
1220 // 1 | | [x, (reg1, piece 32, 32)] <- IsPieceOfPrevEntry
1222 // 3 | [clobber reg0]
1223 // 4 [x, (mem, piece 0, 64)] <- overlapping with both previous pieces of x.
1227 // [0-1] [x, (reg0, piece 0, 32)]
1228 // [1-3] [x, (reg0, piece 0, 32), (reg1, piece 32, 32)]
1229 // [3-4] [x, (reg1, piece 32, 32)]
1230 // [4- ] [x, (mem, piece 0, 64)]
1232 buildLocationList(SmallVectorImpl<DebugLocEntry> &DebugLoc,
1233 const DbgValueHistoryMap::InstrRanges &Ranges,
1234 DwarfCompileUnit *TheCU) {
1235 typedef std::pair<DIVariable, DebugLocEntry::Value> Range;
1236 SmallVector<Range, 4> OpenRanges;
1238 for (auto I = Ranges.begin(), E = Ranges.end(); I != E; ++I) {
1239 const MachineInstr *Begin = I->first;
1240 const MachineInstr *End = I->second;
1241 assert(Begin->isDebugValue() && "Invalid History entry");
1243 // Check if a variable is inaccessible in this range.
1244 if (!Begin->isDebugValue() ||
1245 (Begin->getNumOperands() > 1 && Begin->getOperand(0).isReg() &&
1246 !Begin->getOperand(0).getReg())) {
1251 // If this piece overlaps with any open ranges, truncate them.
1252 DIVariable DIVar = Begin->getDebugVariable();
1253 auto Last = std::remove_if(OpenRanges.begin(), OpenRanges.end(), [&](Range R){
1254 return piecesOverlap(DIVar, R.first);
1256 OpenRanges.erase(Last, OpenRanges.end());
1258 const MCSymbol *StartLabel = getLabelBeforeInsn(Begin);
1259 assert(StartLabel && "Forgot label before DBG_VALUE starting a range!");
1261 const MCSymbol *EndLabel;
1263 EndLabel = getLabelAfterInsn(End);
1264 else if (std::next(I) == Ranges.end())
1265 EndLabel = FunctionEndSym;
1267 EndLabel = getLabelBeforeInsn(std::next(I)->first);
1268 assert(EndLabel && "Forgot label after instruction ending a range!");
1270 DEBUG(dbgs() << "DotDebugLoc: " << *Begin << "\n");
1272 auto Value = getDebugLocValue(Begin);
1273 DebugLocEntry Loc(StartLabel, EndLabel, Value, TheCU);
1274 if (DebugLoc.empty() || !DebugLoc.back().Merge(Loc)) {
1275 // Add all values from still valid non-overlapping pieces.
1276 for (auto Range : OpenRanges)
1277 Loc.addValue(Range.second);
1278 DebugLoc.push_back(std::move(Loc));
1280 // Add this value to the list of open ranges.
1281 if (DIVar.isVariablePiece())
1282 OpenRanges.push_back(std::make_pair(DIVar, Value));
1284 DEBUG(dbgs() << "Values:\n";
1285 for (auto Value : DebugLoc.back().getValues())
1286 Value.getVariable()->dump();
1287 dbgs() << "-----\n");
1292 // Find variables for each lexical scope.
1294 DwarfDebug::collectVariableInfo(SmallPtrSet<const MDNode *, 16> &Processed) {
1295 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1296 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1298 // Grab the variable info that was squirreled away in the MMI side-table.
1299 collectVariableInfoFromMMITable(Processed);
1301 for (const auto &I : DbgValues) {
1302 DIVariable DV(I.first);
1303 if (Processed.count(DV))
1306 // Instruction ranges, specifying where DV is accessible.
1307 const auto &Ranges = I.second;
1311 LexicalScope *Scope = nullptr;
1312 if (DV.getTag() == dwarf::DW_TAG_arg_variable &&
1313 DISubprogram(DV.getContext()).describes(CurFn->getFunction()))
1314 Scope = LScopes.getCurrentFunctionScope();
1315 else if (MDNode *IA = DV.getInlinedAt()) {
1316 DebugLoc DL = DebugLoc::getFromDILocation(IA);
1317 Scope = LScopes.findInlinedScope(DebugLoc::get(
1318 DL.getLine(), DL.getCol(), DV.getContext(), IA));
1320 Scope = LScopes.findLexicalScope(DV.getContext());
1321 // If variable scope is not found then skip this variable.
1325 Processed.insert(getEntireVariable(DV));
1326 const MachineInstr *MInsn = Ranges.front().first;
1327 assert(MInsn->isDebugValue() && "History must begin with debug value");
1328 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
1329 ConcreteVariables.push_back(make_unique<DbgVariable>(MInsn, this));
1330 DbgVariable *RegVar = ConcreteVariables.back().get();
1331 addScopeVariable(Scope, RegVar);
1333 // Check if the first DBG_VALUE is valid for the rest of the function.
1334 if (Ranges.size() == 1 && Ranges.front().second == nullptr)
1337 // Handle multiple DBG_VALUE instructions describing one variable.
1338 RegVar->setDotDebugLocOffset(DotDebugLocEntries.size());
1340 DotDebugLocEntries.resize(DotDebugLocEntries.size() + 1);
1341 DebugLocList &LocList = DotDebugLocEntries.back();
1343 Asm->GetTempSymbol("debug_loc", DotDebugLocEntries.size() - 1);
1345 // Build the location list for this variable.
1346 buildLocationList(LocList.List, Ranges, TheCU);
1349 // Collect info for variables that were optimized out.
1350 DIArray Variables = DISubprogram(FnScope->getScopeNode()).getVariables();
1351 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1352 DIVariable DV(Variables.getElement(i));
1353 assert(DV.isVariable());
1354 if (!Processed.insert(DV))
1356 if (LexicalScope *Scope = LScopes.findLexicalScope(DV.getContext())) {
1357 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
1358 ConcreteVariables.push_back(make_unique<DbgVariable>(DV, this));
1359 addScopeVariable(Scope, ConcreteVariables.back().get());
1364 // Return Label preceding the instruction.
1365 MCSymbol *DwarfDebug::getLabelBeforeInsn(const MachineInstr *MI) {
1366 MCSymbol *Label = LabelsBeforeInsn.lookup(MI);
1367 assert(Label && "Didn't insert label before instruction");
1371 // Return Label immediately following the instruction.
1372 MCSymbol *DwarfDebug::getLabelAfterInsn(const MachineInstr *MI) {
1373 return LabelsAfterInsn.lookup(MI);
1376 // Process beginning of an instruction.
1377 void DwarfDebug::beginInstruction(const MachineInstr *MI) {
1378 assert(CurMI == nullptr);
1380 // Check if source location changes, but ignore DBG_VALUE locations.
1381 if (!MI->isDebugValue()) {
1382 DebugLoc DL = MI->getDebugLoc();
1383 if (DL != PrevInstLoc && (!DL.isUnknown() || UnknownLocations)) {
1386 if (DL == PrologEndLoc) {
1387 Flags |= DWARF2_FLAG_PROLOGUE_END;
1388 PrologEndLoc = DebugLoc();
1390 if (PrologEndLoc.isUnknown())
1391 Flags |= DWARF2_FLAG_IS_STMT;
1393 if (!DL.isUnknown()) {
1394 const MDNode *Scope = DL.getScope(Asm->MF->getFunction()->getContext());
1395 recordSourceLine(DL.getLine(), DL.getCol(), Scope, Flags);
1397 recordSourceLine(0, 0, nullptr, 0);
1401 // Insert labels where requested.
1402 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1403 LabelsBeforeInsn.find(MI);
1406 if (I == LabelsBeforeInsn.end())
1409 // Label already assigned.
1414 PrevLabel = MMI->getContext().CreateTempSymbol();
1415 Asm->OutStreamer.EmitLabel(PrevLabel);
1417 I->second = PrevLabel;
1420 // Process end of an instruction.
1421 void DwarfDebug::endInstruction() {
1422 assert(CurMI != nullptr);
1423 // Don't create a new label after DBG_VALUE instructions.
1424 // They don't generate code.
1425 if (!CurMI->isDebugValue())
1426 PrevLabel = nullptr;
1428 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1429 LabelsAfterInsn.find(CurMI);
1433 if (I == LabelsAfterInsn.end())
1436 // Label already assigned.
1440 // We need a label after this instruction.
1442 PrevLabel = MMI->getContext().CreateTempSymbol();
1443 Asm->OutStreamer.EmitLabel(PrevLabel);
1445 I->second = PrevLabel;
1448 // Each LexicalScope has first instruction and last instruction to mark
1449 // beginning and end of a scope respectively. Create an inverse map that list
1450 // scopes starts (and ends) with an instruction. One instruction may start (or
1451 // end) multiple scopes. Ignore scopes that are not reachable.
1452 void DwarfDebug::identifyScopeMarkers() {
1453 SmallVector<LexicalScope *, 4> WorkList;
1454 WorkList.push_back(LScopes.getCurrentFunctionScope());
1455 while (!WorkList.empty()) {
1456 LexicalScope *S = WorkList.pop_back_val();
1458 const SmallVectorImpl<LexicalScope *> &Children = S->getChildren();
1459 if (!Children.empty())
1460 WorkList.append(Children.begin(), Children.end());
1462 if (S->isAbstractScope())
1465 for (const InsnRange &R : S->getRanges()) {
1466 assert(R.first && "InsnRange does not have first instruction!");
1467 assert(R.second && "InsnRange does not have second instruction!");
1468 requestLabelBeforeInsn(R.first);
1469 requestLabelAfterInsn(R.second);
1474 static DebugLoc findPrologueEndLoc(const MachineFunction *MF) {
1475 // First known non-DBG_VALUE and non-frame setup location marks
1476 // the beginning of the function body.
1477 for (const auto &MBB : *MF)
1478 for (const auto &MI : MBB)
1479 if (!MI.isDebugValue() && !MI.getFlag(MachineInstr::FrameSetup) &&
1480 !MI.getDebugLoc().isUnknown())
1481 return MI.getDebugLoc();
1485 // Gather pre-function debug information. Assumes being called immediately
1486 // after the function entry point has been emitted.
1487 void DwarfDebug::beginFunction(const MachineFunction *MF) {
1490 // If there's no debug info for the function we're not going to do anything.
1491 if (!MMI->hasDebugInfo())
1494 auto DI = FunctionDIs.find(MF->getFunction());
1495 if (DI == FunctionDIs.end())
1498 // Grab the lexical scopes for the function, if we don't have any of those
1499 // then we're not going to be able to do anything.
1500 LScopes.initialize(*MF);
1501 if (LScopes.empty())
1504 assert(DbgValues.empty() && "DbgValues map wasn't cleaned!");
1506 // Make sure that each lexical scope will have a begin/end label.
1507 identifyScopeMarkers();
1509 // Set DwarfDwarfCompileUnitID in MCContext to the Compile Unit this function
1510 // belongs to so that we add to the correct per-cu line table in the
1512 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1513 // FnScope->getScopeNode() and DI->second should represent the same function,
1514 // though they may not be the same MDNode due to inline functions merged in
1515 // LTO where the debug info metadata still differs (either due to distinct
1516 // written differences - two versions of a linkonce_odr function
1517 // written/copied into two separate files, or some sub-optimal metadata that
1518 // isn't structurally identical (see: file path/name info from clang, which
1519 // includes the directory of the cpp file being built, even when the file name
1520 // is absolute (such as an <> lookup header)))
1521 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1522 assert(TheCU && "Unable to find compile unit!");
1523 if (Asm->OutStreamer.hasRawTextSupport())
1524 // Use a single line table if we are generating assembly.
1525 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1527 Asm->OutStreamer.getContext().setDwarfCompileUnitID(TheCU->getUniqueID());
1529 // Emit a label for the function so that we have a beginning address.
1530 FunctionBeginSym = Asm->GetTempSymbol("func_begin", Asm->getFunctionNumber());
1531 // Assumes in correct section after the entry point.
1532 Asm->OutStreamer.EmitLabel(FunctionBeginSym);
1534 // Calculate history for local variables.
1535 calculateDbgValueHistory(MF, Asm->TM.getSubtargetImpl()->getRegisterInfo(),
1538 // Request labels for the full history.
1539 for (const auto &I : DbgValues) {
1540 const auto &Ranges = I.second;
1544 // The first mention of a function argument gets the FunctionBeginSym
1545 // label, so arguments are visible when breaking at function entry.
1546 DIVariable DV(Ranges.front().first->getDebugVariable());
1547 if (DV.isVariable() && DV.getTag() == dwarf::DW_TAG_arg_variable &&
1548 getDISubprogram(DV.getContext()).describes(MF->getFunction())) {
1549 if (!DV.isVariablePiece())
1550 LabelsBeforeInsn[Ranges.front().first] = FunctionBeginSym;
1552 // Mark all non-overlapping initial pieces.
1553 for (auto I = Ranges.begin(); I != Ranges.end(); ++I) {
1554 DIVariable Piece = I->first->getDebugVariable();
1555 if (std::all_of(Ranges.begin(), I,
1556 [&](DbgValueHistoryMap::InstrRange Pred){
1557 return !piecesOverlap(Piece, Pred.first->getDebugVariable());
1559 LabelsBeforeInsn[I->first] = FunctionBeginSym;
1566 for (const auto &Range : Ranges) {
1567 requestLabelBeforeInsn(Range.first);
1569 requestLabelAfterInsn(Range.second);
1573 PrevInstLoc = DebugLoc();
1574 PrevLabel = FunctionBeginSym;
1576 // Record beginning of function.
1577 PrologEndLoc = findPrologueEndLoc(MF);
1578 if (!PrologEndLoc.isUnknown()) {
1579 DebugLoc FnStartDL =
1580 PrologEndLoc.getFnDebugLoc(MF->getFunction()->getContext());
1582 FnStartDL.getLine(), FnStartDL.getCol(),
1583 FnStartDL.getScope(MF->getFunction()->getContext()),
1584 // We'd like to list the prologue as "not statements" but GDB behaves
1585 // poorly if we do that. Revisit this with caution/GDB (7.5+) testing.
1586 DWARF2_FLAG_IS_STMT);
1590 void DwarfDebug::addScopeVariable(LexicalScope *LS, DbgVariable *Var) {
1591 if (addCurrentFnArgument(Var, LS))
1593 SmallVectorImpl<DbgVariable *> &Vars = ScopeVariables[LS];
1594 DIVariable DV = Var->getVariable();
1595 // Variables with positive arg numbers are parameters.
1596 if (unsigned ArgNum = DV.getArgNumber()) {
1597 // Keep all parameters in order at the start of the variable list to ensure
1598 // function types are correct (no out-of-order parameters)
1600 // This could be improved by only doing it for optimized builds (unoptimized
1601 // builds have the right order to begin with), searching from the back (this
1602 // would catch the unoptimized case quickly), or doing a binary search
1603 // rather than linear search.
1604 SmallVectorImpl<DbgVariable *>::iterator I = Vars.begin();
1605 while (I != Vars.end()) {
1606 unsigned CurNum = (*I)->getVariable().getArgNumber();
1607 // A local (non-parameter) variable has been found, insert immediately
1611 // A later indexed parameter has been found, insert immediately before it.
1612 if (CurNum > ArgNum)
1616 Vars.insert(I, Var);
1620 Vars.push_back(Var);
1623 // Gather and emit post-function debug information.
1624 void DwarfDebug::endFunction(const MachineFunction *MF) {
1625 // Every beginFunction(MF) call should be followed by an endFunction(MF) call,
1626 // though the beginFunction may not be called at all.
1627 // We should handle both cases.
1631 assert(CurFn == MF);
1632 assert(CurFn != nullptr);
1634 if (!MMI->hasDebugInfo() || LScopes.empty() ||
1635 !FunctionDIs.count(MF->getFunction())) {
1636 // If we don't have a lexical scope for this function then there will
1637 // be a hole in the range information. Keep note of this by setting the
1638 // previously used section to nullptr.
1639 PrevSection = nullptr;
1645 // Define end label for subprogram.
1646 FunctionEndSym = Asm->GetTempSymbol("func_end", Asm->getFunctionNumber());
1647 // Assumes in correct section after the entry point.
1648 Asm->OutStreamer.EmitLabel(FunctionEndSym);
1650 // Set DwarfDwarfCompileUnitID in MCContext to default value.
1651 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1653 SmallPtrSet<const MDNode *, 16> ProcessedVars;
1654 collectVariableInfo(ProcessedVars);
1656 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1657 DwarfCompileUnit &TheCU = *SPMap.lookup(FnScope->getScopeNode());
1659 // Construct abstract scopes.
1660 for (LexicalScope *AScope : LScopes.getAbstractScopesList()) {
1661 DISubprogram SP(AScope->getScopeNode());
1662 assert(SP.isSubprogram());
1663 // Collect info for variables that were optimized out.
1664 DIArray Variables = SP.getVariables();
1665 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1666 DIVariable DV(Variables.getElement(i));
1667 assert(DV && DV.isVariable());
1668 if (!ProcessedVars.insert(DV))
1670 ensureAbstractVariableIsCreated(DV, DV.getContext());
1672 constructAbstractSubprogramScopeDIE(TheCU, AScope);
1675 DIE &CurFnDIE = constructSubprogramScopeDIE(TheCU, FnScope);
1676 if (!CurFn->getTarget().Options.DisableFramePointerElim(*CurFn))
1677 TheCU.addFlag(CurFnDIE, dwarf::DW_AT_APPLE_omit_frame_ptr);
1679 // Add the range of this function to the list of ranges for the CU.
1680 RangeSpan Span(FunctionBeginSym, FunctionEndSym);
1681 TheCU.addRange(std::move(Span));
1682 PrevSection = Asm->getCurrentSection();
1686 // Ownership of DbgVariables is a bit subtle - ScopeVariables owns all the
1687 // DbgVariables except those that are also in AbstractVariables (since they
1688 // can be used cross-function)
1689 ScopeVariables.clear();
1690 CurrentFnArguments.clear();
1692 LabelsBeforeInsn.clear();
1693 LabelsAfterInsn.clear();
1694 PrevLabel = nullptr;
1698 // Register a source line with debug info. Returns the unique label that was
1699 // emitted and which provides correspondence to the source line list.
1700 void DwarfDebug::recordSourceLine(unsigned Line, unsigned Col, const MDNode *S,
1705 unsigned Discriminator = 0;
1706 if (DIScope Scope = DIScope(S)) {
1707 assert(Scope.isScope());
1708 Fn = Scope.getFilename();
1709 Dir = Scope.getDirectory();
1710 if (Scope.isLexicalBlock())
1711 Discriminator = DILexicalBlock(S).getDiscriminator();
1713 unsigned CUID = Asm->OutStreamer.getContext().getDwarfCompileUnitID();
1714 Src = static_cast<DwarfCompileUnit &>(*InfoHolder.getUnits()[CUID])
1715 .getOrCreateSourceID(Fn, Dir);
1717 Asm->OutStreamer.EmitDwarfLocDirective(Src, Line, Col, Flags, 0,
1721 //===----------------------------------------------------------------------===//
1723 //===----------------------------------------------------------------------===//
1725 // Emit initial Dwarf sections with a label at the start of each one.
1726 void DwarfDebug::emitSectionLabels() {
1727 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
1729 // Dwarf sections base addresses.
1730 DwarfInfoSectionSym =
1731 emitSectionSym(Asm, TLOF.getDwarfInfoSection(), "section_info");
1732 if (useSplitDwarf()) {
1733 DwarfInfoDWOSectionSym =
1734 emitSectionSym(Asm, TLOF.getDwarfInfoDWOSection(), "section_info_dwo");
1735 DwarfTypesDWOSectionSym =
1736 emitSectionSym(Asm, TLOF.getDwarfTypesDWOSection(), "section_types_dwo");
1738 DwarfAbbrevSectionSym =
1739 emitSectionSym(Asm, TLOF.getDwarfAbbrevSection(), "section_abbrev");
1740 if (useSplitDwarf())
1741 DwarfAbbrevDWOSectionSym = emitSectionSym(
1742 Asm, TLOF.getDwarfAbbrevDWOSection(), "section_abbrev_dwo");
1743 if (GenerateARangeSection)
1744 emitSectionSym(Asm, TLOF.getDwarfARangesSection());
1746 DwarfLineSectionSym =
1747 emitSectionSym(Asm, TLOF.getDwarfLineSection(), "section_line");
1748 if (GenerateGnuPubSections) {
1749 DwarfGnuPubNamesSectionSym =
1750 emitSectionSym(Asm, TLOF.getDwarfGnuPubNamesSection());
1751 DwarfGnuPubTypesSectionSym =
1752 emitSectionSym(Asm, TLOF.getDwarfGnuPubTypesSection());
1753 } else if (HasDwarfPubSections) {
1754 emitSectionSym(Asm, TLOF.getDwarfPubNamesSection());
1755 emitSectionSym(Asm, TLOF.getDwarfPubTypesSection());
1758 DwarfStrSectionSym =
1759 emitSectionSym(Asm, TLOF.getDwarfStrSection(), "info_string");
1760 if (useSplitDwarf()) {
1761 DwarfStrDWOSectionSym =
1762 emitSectionSym(Asm, TLOF.getDwarfStrDWOSection(), "skel_string");
1763 DwarfAddrSectionSym =
1764 emitSectionSym(Asm, TLOF.getDwarfAddrSection(), "addr_sec");
1765 DwarfDebugLocSectionSym =
1766 emitSectionSym(Asm, TLOF.getDwarfLocDWOSection(), "skel_loc");
1768 DwarfDebugLocSectionSym =
1769 emitSectionSym(Asm, TLOF.getDwarfLocSection(), "section_debug_loc");
1770 DwarfDebugRangeSectionSym =
1771 emitSectionSym(Asm, TLOF.getDwarfRangesSection(), "debug_range");
1774 // Recursively emits a debug information entry.
1775 void DwarfDebug::emitDIE(DIE &Die) {
1776 // Get the abbreviation for this DIE.
1777 const DIEAbbrev &Abbrev = Die.getAbbrev();
1779 // Emit the code (index) for the abbreviation.
1780 if (Asm->isVerbose())
1781 Asm->OutStreamer.AddComment("Abbrev [" + Twine(Abbrev.getNumber()) +
1782 "] 0x" + Twine::utohexstr(Die.getOffset()) +
1783 ":0x" + Twine::utohexstr(Die.getSize()) + " " +
1784 dwarf::TagString(Abbrev.getTag()));
1785 Asm->EmitULEB128(Abbrev.getNumber());
1787 const SmallVectorImpl<DIEValue *> &Values = Die.getValues();
1788 const SmallVectorImpl<DIEAbbrevData> &AbbrevData = Abbrev.getData();
1790 // Emit the DIE attribute values.
1791 for (unsigned i = 0, N = Values.size(); i < N; ++i) {
1792 dwarf::Attribute Attr = AbbrevData[i].getAttribute();
1793 dwarf::Form Form = AbbrevData[i].getForm();
1794 assert(Form && "Too many attributes for DIE (check abbreviation)");
1796 if (Asm->isVerbose()) {
1797 Asm->OutStreamer.AddComment(dwarf::AttributeString(Attr));
1798 if (Attr == dwarf::DW_AT_accessibility)
1799 Asm->OutStreamer.AddComment(dwarf::AccessibilityString(
1800 cast<DIEInteger>(Values[i])->getValue()));
1803 // Emit an attribute using the defined form.
1804 Values[i]->EmitValue(Asm, Form);
1807 // Emit the DIE children if any.
1808 if (Abbrev.hasChildren()) {
1809 for (auto &Child : Die.getChildren())
1812 Asm->OutStreamer.AddComment("End Of Children Mark");
1817 // Emit the debug info section.
1818 void DwarfDebug::emitDebugInfo() {
1819 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1821 Holder.emitUnits(this, DwarfAbbrevSectionSym);
1824 // Emit the abbreviation section.
1825 void DwarfDebug::emitAbbreviations() {
1826 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1828 Holder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevSection());
1831 // Emit the last address of the section and the end of the line matrix.
1832 void DwarfDebug::emitEndOfLineMatrix(unsigned SectionEnd) {
1833 // Define last address of section.
1834 Asm->OutStreamer.AddComment("Extended Op");
1837 Asm->OutStreamer.AddComment("Op size");
1838 Asm->EmitInt8(Asm->getDataLayout().getPointerSize() + 1);
1839 Asm->OutStreamer.AddComment("DW_LNE_set_address");
1840 Asm->EmitInt8(dwarf::DW_LNE_set_address);
1842 Asm->OutStreamer.AddComment("Section end label");
1844 Asm->OutStreamer.EmitSymbolValue(
1845 Asm->GetTempSymbol("section_end", SectionEnd),
1846 Asm->getDataLayout().getPointerSize());
1848 // Mark end of matrix.
1849 Asm->OutStreamer.AddComment("DW_LNE_end_sequence");
1855 // Emit visible names into a hashed accelerator table section.
1856 void DwarfDebug::emitAccelNames() {
1857 AccelNames.FinalizeTable(Asm, "Names");
1858 Asm->OutStreamer.SwitchSection(
1859 Asm->getObjFileLowering().getDwarfAccelNamesSection());
1860 MCSymbol *SectionBegin = Asm->GetTempSymbol("names_begin");
1861 Asm->OutStreamer.EmitLabel(SectionBegin);
1863 // Emit the full data.
1864 AccelNames.Emit(Asm, SectionBegin, &InfoHolder);
1867 // Emit objective C classes and categories into a hashed accelerator table
1869 void DwarfDebug::emitAccelObjC() {
1870 AccelObjC.FinalizeTable(Asm, "ObjC");
1871 Asm->OutStreamer.SwitchSection(
1872 Asm->getObjFileLowering().getDwarfAccelObjCSection());
1873 MCSymbol *SectionBegin = Asm->GetTempSymbol("objc_begin");
1874 Asm->OutStreamer.EmitLabel(SectionBegin);
1876 // Emit the full data.
1877 AccelObjC.Emit(Asm, SectionBegin, &InfoHolder);
1880 // Emit namespace dies into a hashed accelerator table.
1881 void DwarfDebug::emitAccelNamespaces() {
1882 AccelNamespace.FinalizeTable(Asm, "namespac");
1883 Asm->OutStreamer.SwitchSection(
1884 Asm->getObjFileLowering().getDwarfAccelNamespaceSection());
1885 MCSymbol *SectionBegin = Asm->GetTempSymbol("namespac_begin");
1886 Asm->OutStreamer.EmitLabel(SectionBegin);
1888 // Emit the full data.
1889 AccelNamespace.Emit(Asm, SectionBegin, &InfoHolder);
1892 // Emit type dies into a hashed accelerator table.
1893 void DwarfDebug::emitAccelTypes() {
1895 AccelTypes.FinalizeTable(Asm, "types");
1896 Asm->OutStreamer.SwitchSection(
1897 Asm->getObjFileLowering().getDwarfAccelTypesSection());
1898 MCSymbol *SectionBegin = Asm->GetTempSymbol("types_begin");
1899 Asm->OutStreamer.EmitLabel(SectionBegin);
1901 // Emit the full data.
1902 AccelTypes.Emit(Asm, SectionBegin, &InfoHolder);
1905 // Public name handling.
1906 // The format for the various pubnames:
1908 // dwarf pubnames - offset/name pairs where the offset is the offset into the CU
1909 // for the DIE that is named.
1911 // gnu pubnames - offset/index value/name tuples where the offset is the offset
1912 // into the CU and the index value is computed according to the type of value
1913 // for the DIE that is named.
1915 // For type units the offset is the offset of the skeleton DIE. For split dwarf
1916 // it's the offset within the debug_info/debug_types dwo section, however, the
1917 // reference in the pubname header doesn't change.
1919 /// computeIndexValue - Compute the gdb index value for the DIE and CU.
1920 static dwarf::PubIndexEntryDescriptor computeIndexValue(DwarfUnit *CU,
1922 dwarf::GDBIndexEntryLinkage Linkage = dwarf::GIEL_STATIC;
1924 // We could have a specification DIE that has our most of our knowledge,
1925 // look for that now.
1926 DIEValue *SpecVal = Die->findAttribute(dwarf::DW_AT_specification);
1928 DIE &SpecDIE = cast<DIEEntry>(SpecVal)->getEntry();
1929 if (SpecDIE.findAttribute(dwarf::DW_AT_external))
1930 Linkage = dwarf::GIEL_EXTERNAL;
1931 } else if (Die->findAttribute(dwarf::DW_AT_external))
1932 Linkage = dwarf::GIEL_EXTERNAL;
1934 switch (Die->getTag()) {
1935 case dwarf::DW_TAG_class_type:
1936 case dwarf::DW_TAG_structure_type:
1937 case dwarf::DW_TAG_union_type:
1938 case dwarf::DW_TAG_enumeration_type:
1939 return dwarf::PubIndexEntryDescriptor(
1940 dwarf::GIEK_TYPE, CU->getLanguage() != dwarf::DW_LANG_C_plus_plus
1941 ? dwarf::GIEL_STATIC
1942 : dwarf::GIEL_EXTERNAL);
1943 case dwarf::DW_TAG_typedef:
1944 case dwarf::DW_TAG_base_type:
1945 case dwarf::DW_TAG_subrange_type:
1946 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_TYPE, dwarf::GIEL_STATIC);
1947 case dwarf::DW_TAG_namespace:
1948 return dwarf::GIEK_TYPE;
1949 case dwarf::DW_TAG_subprogram:
1950 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_FUNCTION, Linkage);
1951 case dwarf::DW_TAG_constant:
1952 case dwarf::DW_TAG_variable:
1953 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE, Linkage);
1954 case dwarf::DW_TAG_enumerator:
1955 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE,
1956 dwarf::GIEL_STATIC);
1958 return dwarf::GIEK_NONE;
1962 /// emitDebugPubNames - Emit visible names into a debug pubnames section.
1964 void DwarfDebug::emitDebugPubNames(bool GnuStyle) {
1965 const MCSection *PSec =
1966 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubNamesSection()
1967 : Asm->getObjFileLowering().getDwarfPubNamesSection();
1969 emitDebugPubSection(GnuStyle, PSec, "Names", &DwarfUnit::getGlobalNames);
1972 void DwarfDebug::emitDebugPubSection(
1973 bool GnuStyle, const MCSection *PSec, StringRef Name,
1974 const StringMap<const DIE *> &(DwarfUnit::*Accessor)() const) {
1975 for (const auto &NU : CUMap) {
1976 DwarfCompileUnit *TheU = NU.second;
1978 const auto &Globals = (TheU->*Accessor)();
1980 if (Globals.empty())
1983 if (auto Skeleton = static_cast<DwarfCompileUnit *>(TheU->getSkeleton()))
1985 unsigned ID = TheU->getUniqueID();
1987 // Start the dwarf pubnames section.
1988 Asm->OutStreamer.SwitchSection(PSec);
1991 Asm->OutStreamer.AddComment("Length of Public " + Name + " Info");
1992 MCSymbol *BeginLabel = Asm->GetTempSymbol("pub" + Name + "_begin", ID);
1993 MCSymbol *EndLabel = Asm->GetTempSymbol("pub" + Name + "_end", ID);
1994 Asm->EmitLabelDifference(EndLabel, BeginLabel, 4);
1996 Asm->OutStreamer.EmitLabel(BeginLabel);
1998 Asm->OutStreamer.AddComment("DWARF Version");
1999 Asm->EmitInt16(dwarf::DW_PUBNAMES_VERSION);
2001 Asm->OutStreamer.AddComment("Offset of Compilation Unit Info");
2002 Asm->EmitSectionOffset(TheU->getLabelBegin(), TheU->getSectionSym());
2004 Asm->OutStreamer.AddComment("Compilation Unit Length");
2005 Asm->EmitLabelDifference(TheU->getLabelEnd(), TheU->getLabelBegin(), 4);
2007 // Emit the pubnames for this compilation unit.
2008 for (const auto &GI : Globals) {
2009 const char *Name = GI.getKeyData();
2010 const DIE *Entity = GI.second;
2012 Asm->OutStreamer.AddComment("DIE offset");
2013 Asm->EmitInt32(Entity->getOffset());
2016 dwarf::PubIndexEntryDescriptor Desc = computeIndexValue(TheU, Entity);
2017 Asm->OutStreamer.AddComment(
2018 Twine("Kind: ") + dwarf::GDBIndexEntryKindString(Desc.Kind) + ", " +
2019 dwarf::GDBIndexEntryLinkageString(Desc.Linkage));
2020 Asm->EmitInt8(Desc.toBits());
2023 Asm->OutStreamer.AddComment("External Name");
2024 Asm->OutStreamer.EmitBytes(StringRef(Name, GI.getKeyLength() + 1));
2027 Asm->OutStreamer.AddComment("End Mark");
2029 Asm->OutStreamer.EmitLabel(EndLabel);
2033 void DwarfDebug::emitDebugPubTypes(bool GnuStyle) {
2034 const MCSection *PSec =
2035 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubTypesSection()
2036 : Asm->getObjFileLowering().getDwarfPubTypesSection();
2038 emitDebugPubSection(GnuStyle, PSec, "Types", &DwarfUnit::getGlobalTypes);
2041 // Emit visible names into a debug str section.
2042 void DwarfDebug::emitDebugStr() {
2043 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
2044 Holder.emitStrings(Asm->getObjFileLowering().getDwarfStrSection());
2047 /// Emits an optimal (=sorted) sequence of DW_OP_pieces.
2048 void DwarfDebug::emitLocPieces(ByteStreamer &Streamer,
2049 const DITypeIdentifierMap &Map,
2050 ArrayRef<DebugLocEntry::Value> Values) {
2051 typedef DebugLocEntry::Value Piece;
2052 SmallVector<Piece, 4> Pieces(Values.begin(), Values.end());
2053 assert(std::all_of(Pieces.begin(), Pieces.end(), [](Piece &P) {
2054 return DIVariable(P.getVariable()).isVariablePiece();
2055 }) && "all values are expected to be pieces");
2057 // Sort the pieces so they can be emitted using DW_OP_piece.
2058 std::sort(Pieces.begin(), Pieces.end(), [](const Piece &A, const Piece &B) {
2059 DIVariable VarA(A.getVariable());
2060 DIVariable VarB(B.getVariable());
2061 return VarA.getPieceOffset() < VarB.getPieceOffset();
2063 // Remove any duplicate entries by dropping all but the first.
2064 Pieces.erase(std::unique(Pieces.begin(), Pieces.end(),
2065 [] (const Piece &A,const Piece &B){
2066 return A.getVariable() == B.getVariable();
2069 unsigned Offset = 0;
2070 for (auto Piece : Pieces) {
2071 DIVariable Var(Piece.getVariable());
2072 unsigned PieceOffset = Var.getPieceOffset();
2073 unsigned PieceSize = Var.getPieceSize();
2074 assert(Offset <= PieceOffset && "overlapping pieces in DebugLocEntry");
2075 if (Offset < PieceOffset) {
2076 // The DWARF spec seriously mandates pieces with no locations for gaps.
2077 Asm->EmitDwarfOpPiece(Streamer, (PieceOffset-Offset)*8);
2078 Offset += PieceOffset-Offset;
2081 Offset += PieceSize;
2083 const unsigned SizeOfByte = 8;
2084 assert(!Var.isIndirect() && "indirect address for piece");
2086 unsigned VarSize = Var.getSizeInBits(Map);
2087 assert(PieceSize+PieceOffset <= VarSize/SizeOfByte
2088 && "piece is larger than or outside of variable");
2089 assert(PieceSize*SizeOfByte != VarSize
2090 && "piece covers entire variable");
2092 if (Piece.isLocation() && Piece.getLoc().isReg())
2093 Asm->EmitDwarfRegOpPiece(Streamer,
2095 PieceSize*SizeOfByte);
2097 emitDebugLocValue(Streamer, Piece);
2098 Asm->EmitDwarfOpPiece(Streamer, PieceSize*SizeOfByte);
2104 void DwarfDebug::emitDebugLocEntry(ByteStreamer &Streamer,
2105 const DebugLocEntry &Entry) {
2106 const DebugLocEntry::Value Value = Entry.getValues()[0];
2107 DIVariable DV(Value.getVariable());
2108 if (DV.isVariablePiece())
2109 // Emit all pieces that belong to the same variable and range.
2110 return emitLocPieces(Streamer, TypeIdentifierMap, Entry.getValues());
2112 assert(Entry.getValues().size() == 1 && "only pieces may have >1 value");
2113 emitDebugLocValue(Streamer, Value);
2116 void DwarfDebug::emitDebugLocValue(ByteStreamer &Streamer,
2117 const DebugLocEntry::Value &Value) {
2118 DIVariable DV(Value.getVariable());
2120 if (Value.isInt()) {
2121 DIBasicType BTy(resolve(DV.getType()));
2122 if (BTy.Verify() && (BTy.getEncoding() == dwarf::DW_ATE_signed ||
2123 BTy.getEncoding() == dwarf::DW_ATE_signed_char)) {
2124 Streamer.EmitInt8(dwarf::DW_OP_consts, "DW_OP_consts");
2125 Streamer.EmitSLEB128(Value.getInt());
2127 Streamer.EmitInt8(dwarf::DW_OP_constu, "DW_OP_constu");
2128 Streamer.EmitULEB128(Value.getInt());
2130 } else if (Value.isLocation()) {
2131 MachineLocation Loc = Value.getLoc();
2132 if (!DV.hasComplexAddress())
2134 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2136 // Complex address entry.
2137 unsigned N = DV.getNumAddrElements();
2139 if (N >= 2 && DV.getAddrElement(0) == DIBuilder::OpPlus) {
2140 if (Loc.getOffset()) {
2142 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2143 Streamer.EmitInt8(dwarf::DW_OP_deref, "DW_OP_deref");
2144 Streamer.EmitInt8(dwarf::DW_OP_plus_uconst, "DW_OP_plus_uconst");
2145 Streamer.EmitSLEB128(DV.getAddrElement(1));
2147 // If first address element is OpPlus then emit
2148 // DW_OP_breg + Offset instead of DW_OP_reg + Offset.
2149 MachineLocation TLoc(Loc.getReg(), DV.getAddrElement(1));
2150 Asm->EmitDwarfRegOp(Streamer, TLoc, DV.isIndirect());
2154 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2157 // Emit remaining complex address elements.
2158 for (; i < N; ++i) {
2159 uint64_t Element = DV.getAddrElement(i);
2160 if (Element == DIBuilder::OpPlus) {
2161 Streamer.EmitInt8(dwarf::DW_OP_plus_uconst, "DW_OP_plus_uconst");
2162 Streamer.EmitULEB128(DV.getAddrElement(++i));
2163 } else if (Element == DIBuilder::OpDeref) {
2165 Streamer.EmitInt8(dwarf::DW_OP_deref, "DW_OP_deref");
2166 } else if (Element == DIBuilder::OpPiece) {
2168 // handled in emitDebugLocEntry.
2170 llvm_unreachable("unknown Opcode found in complex address");
2174 // else ... ignore constant fp. There is not any good way to
2175 // to represent them here in dwarf.
2179 void DwarfDebug::emitDebugLocEntryLocation(const DebugLocEntry &Entry) {
2180 Asm->OutStreamer.AddComment("Loc expr size");
2181 MCSymbol *begin = Asm->OutStreamer.getContext().CreateTempSymbol();
2182 MCSymbol *end = Asm->OutStreamer.getContext().CreateTempSymbol();
2183 Asm->EmitLabelDifference(end, begin, 2);
2184 Asm->OutStreamer.EmitLabel(begin);
2186 APByteStreamer Streamer(*Asm);
2187 emitDebugLocEntry(Streamer, Entry);
2189 Asm->OutStreamer.EmitLabel(end);
2192 // Emit locations into the debug loc section.
2193 void DwarfDebug::emitDebugLoc() {
2194 // Start the dwarf loc section.
2195 Asm->OutStreamer.SwitchSection(
2196 Asm->getObjFileLowering().getDwarfLocSection());
2197 unsigned char Size = Asm->getDataLayout().getPointerSize();
2198 for (const auto &DebugLoc : DotDebugLocEntries) {
2199 Asm->OutStreamer.EmitLabel(DebugLoc.Label);
2200 for (const auto &Entry : DebugLoc.List) {
2201 // Set up the range. This range is relative to the entry point of the
2202 // compile unit. This is a hard coded 0 for low_pc when we're emitting
2203 // ranges, or the DW_AT_low_pc on the compile unit otherwise.
2204 const DwarfCompileUnit *CU = Entry.getCU();
2205 if (CU->getRanges().size() == 1) {
2206 // Grab the begin symbol from the first range as our base.
2207 const MCSymbol *Base = CU->getRanges()[0].getStart();
2208 Asm->EmitLabelDifference(Entry.getBeginSym(), Base, Size);
2209 Asm->EmitLabelDifference(Entry.getEndSym(), Base, Size);
2211 Asm->OutStreamer.EmitSymbolValue(Entry.getBeginSym(), Size);
2212 Asm->OutStreamer.EmitSymbolValue(Entry.getEndSym(), Size);
2215 emitDebugLocEntryLocation(Entry);
2217 Asm->OutStreamer.EmitIntValue(0, Size);
2218 Asm->OutStreamer.EmitIntValue(0, Size);
2222 void DwarfDebug::emitDebugLocDWO() {
2223 Asm->OutStreamer.SwitchSection(
2224 Asm->getObjFileLowering().getDwarfLocDWOSection());
2225 for (const auto &DebugLoc : DotDebugLocEntries) {
2226 Asm->OutStreamer.EmitLabel(DebugLoc.Label);
2227 for (const auto &Entry : DebugLoc.List) {
2228 // Just always use start_length for now - at least that's one address
2229 // rather than two. We could get fancier and try to, say, reuse an
2230 // address we know we've emitted elsewhere (the start of the function?
2231 // The start of the CU or CU subrange that encloses this range?)
2232 Asm->EmitInt8(dwarf::DW_LLE_start_length_entry);
2233 unsigned idx = AddrPool.getIndex(Entry.getBeginSym());
2234 Asm->EmitULEB128(idx);
2235 Asm->EmitLabelDifference(Entry.getEndSym(), Entry.getBeginSym(), 4);
2237 emitDebugLocEntryLocation(Entry);
2239 Asm->EmitInt8(dwarf::DW_LLE_end_of_list_entry);
2244 const MCSymbol *Start, *End;
2247 // Emit a debug aranges section, containing a CU lookup for any
2248 // address we can tie back to a CU.
2249 void DwarfDebug::emitDebugARanges() {
2250 // Start the dwarf aranges section.
2251 Asm->OutStreamer.SwitchSection(
2252 Asm->getObjFileLowering().getDwarfARangesSection());
2254 typedef DenseMap<DwarfCompileUnit *, std::vector<ArangeSpan>> SpansType;
2258 // Build a list of sections used.
2259 std::vector<const MCSection *> Sections;
2260 for (const auto &it : SectionMap) {
2261 const MCSection *Section = it.first;
2262 Sections.push_back(Section);
2265 // Sort the sections into order.
2266 // This is only done to ensure consistent output order across different runs.
2267 std::sort(Sections.begin(), Sections.end(), SectionSort);
2269 // Build a set of address spans, sorted by CU.
2270 for (const MCSection *Section : Sections) {
2271 SmallVector<SymbolCU, 8> &List = SectionMap[Section];
2272 if (List.size() < 2)
2275 // Sort the symbols by offset within the section.
2276 std::sort(List.begin(), List.end(),
2277 [&](const SymbolCU &A, const SymbolCU &B) {
2278 unsigned IA = A.Sym ? Asm->OutStreamer.GetSymbolOrder(A.Sym) : 0;
2279 unsigned IB = B.Sym ? Asm->OutStreamer.GetSymbolOrder(B.Sym) : 0;
2281 // Symbols with no order assigned should be placed at the end.
2282 // (e.g. section end labels)
2290 // If we have no section (e.g. common), just write out
2291 // individual spans for each symbol.
2293 for (const SymbolCU &Cur : List) {
2295 Span.Start = Cur.Sym;
2298 Spans[Cur.CU].push_back(Span);
2301 // Build spans between each label.
2302 const MCSymbol *StartSym = List[0].Sym;
2303 for (size_t n = 1, e = List.size(); n < e; n++) {
2304 const SymbolCU &Prev = List[n - 1];
2305 const SymbolCU &Cur = List[n];
2307 // Try and build the longest span we can within the same CU.
2308 if (Cur.CU != Prev.CU) {
2310 Span.Start = StartSym;
2312 Spans[Prev.CU].push_back(Span);
2319 unsigned PtrSize = Asm->getDataLayout().getPointerSize();
2321 // Build a list of CUs used.
2322 std::vector<DwarfCompileUnit *> CUs;
2323 for (const auto &it : Spans) {
2324 DwarfCompileUnit *CU = it.first;
2328 // Sort the CU list (again, to ensure consistent output order).
2329 std::sort(CUs.begin(), CUs.end(), [](const DwarfUnit *A, const DwarfUnit *B) {
2330 return A->getUniqueID() < B->getUniqueID();
2333 // Emit an arange table for each CU we used.
2334 for (DwarfCompileUnit *CU : CUs) {
2335 std::vector<ArangeSpan> &List = Spans[CU];
2337 // Emit size of content not including length itself.
2338 unsigned ContentSize =
2339 sizeof(int16_t) + // DWARF ARange version number
2340 sizeof(int32_t) + // Offset of CU in the .debug_info section
2341 sizeof(int8_t) + // Pointer Size (in bytes)
2342 sizeof(int8_t); // Segment Size (in bytes)
2344 unsigned TupleSize = PtrSize * 2;
2346 // 7.20 in the Dwarf specs requires the table to be aligned to a tuple.
2348 OffsetToAlignment(sizeof(int32_t) + ContentSize, TupleSize);
2350 ContentSize += Padding;
2351 ContentSize += (List.size() + 1) * TupleSize;
2353 // For each compile unit, write the list of spans it covers.
2354 Asm->OutStreamer.AddComment("Length of ARange Set");
2355 Asm->EmitInt32(ContentSize);
2356 Asm->OutStreamer.AddComment("DWARF Arange version number");
2357 Asm->EmitInt16(dwarf::DW_ARANGES_VERSION);
2358 Asm->OutStreamer.AddComment("Offset Into Debug Info Section");
2359 Asm->EmitSectionOffset(CU->getLocalLabelBegin(), CU->getLocalSectionSym());
2360 Asm->OutStreamer.AddComment("Address Size (in bytes)");
2361 Asm->EmitInt8(PtrSize);
2362 Asm->OutStreamer.AddComment("Segment Size (in bytes)");
2365 Asm->OutStreamer.EmitFill(Padding, 0xff);
2367 for (const ArangeSpan &Span : List) {
2368 Asm->EmitLabelReference(Span.Start, PtrSize);
2370 // Calculate the size as being from the span start to it's end.
2372 Asm->EmitLabelDifference(Span.End, Span.Start, PtrSize);
2374 // For symbols without an end marker (e.g. common), we
2375 // write a single arange entry containing just that one symbol.
2376 uint64_t Size = SymSize[Span.Start];
2380 Asm->OutStreamer.EmitIntValue(Size, PtrSize);
2384 Asm->OutStreamer.AddComment("ARange terminator");
2385 Asm->OutStreamer.EmitIntValue(0, PtrSize);
2386 Asm->OutStreamer.EmitIntValue(0, PtrSize);
2390 // Emit visible names into a debug ranges section.
2391 void DwarfDebug::emitDebugRanges() {
2392 // Start the dwarf ranges section.
2393 Asm->OutStreamer.SwitchSection(
2394 Asm->getObjFileLowering().getDwarfRangesSection());
2396 // Size for our labels.
2397 unsigned char Size = Asm->getDataLayout().getPointerSize();
2399 // Grab the specific ranges for the compile units in the module.
2400 for (const auto &I : CUMap) {
2401 DwarfCompileUnit *TheCU = I.second;
2403 // Iterate over the misc ranges for the compile units in the module.
2404 for (const RangeSpanList &List : TheCU->getRangeLists()) {
2405 // Emit our symbol so we can find the beginning of the range.
2406 Asm->OutStreamer.EmitLabel(List.getSym());
2408 for (const RangeSpan &Range : List.getRanges()) {
2409 const MCSymbol *Begin = Range.getStart();
2410 const MCSymbol *End = Range.getEnd();
2411 assert(Begin && "Range without a begin symbol?");
2412 assert(End && "Range without an end symbol?");
2413 if (TheCU->getRanges().size() == 1) {
2414 // Grab the begin symbol from the first range as our base.
2415 const MCSymbol *Base = TheCU->getRanges()[0].getStart();
2416 Asm->EmitLabelDifference(Begin, Base, Size);
2417 Asm->EmitLabelDifference(End, Base, Size);
2419 Asm->OutStreamer.EmitSymbolValue(Begin, Size);
2420 Asm->OutStreamer.EmitSymbolValue(End, Size);
2424 // And terminate the list with two 0 values.
2425 Asm->OutStreamer.EmitIntValue(0, Size);
2426 Asm->OutStreamer.EmitIntValue(0, Size);
2429 // Now emit a range for the CU itself.
2430 if (TheCU->getRanges().size() > 1) {
2431 Asm->OutStreamer.EmitLabel(
2432 Asm->GetTempSymbol("cu_ranges", TheCU->getUniqueID()));
2433 for (const RangeSpan &Range : TheCU->getRanges()) {
2434 const MCSymbol *Begin = Range.getStart();
2435 const MCSymbol *End = Range.getEnd();
2436 assert(Begin && "Range without a begin symbol?");
2437 assert(End && "Range without an end symbol?");
2438 Asm->OutStreamer.EmitSymbolValue(Begin, Size);
2439 Asm->OutStreamer.EmitSymbolValue(End, Size);
2441 // And terminate the list with two 0 values.
2442 Asm->OutStreamer.EmitIntValue(0, Size);
2443 Asm->OutStreamer.EmitIntValue(0, Size);
2448 // DWARF5 Experimental Separate Dwarf emitters.
2450 void DwarfDebug::initSkeletonUnit(const DwarfUnit &U, DIE &Die,
2451 std::unique_ptr<DwarfUnit> NewU) {
2452 NewU->addLocalString(Die, dwarf::DW_AT_GNU_dwo_name,
2453 U.getCUNode().getSplitDebugFilename());
2455 if (!CompilationDir.empty())
2456 NewU->addLocalString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
2458 addGnuPubAttributes(*NewU, Die);
2460 SkeletonHolder.addUnit(std::move(NewU));
2463 // This DIE has the following attributes: DW_AT_comp_dir, DW_AT_stmt_list,
2464 // DW_AT_low_pc, DW_AT_high_pc, DW_AT_ranges, DW_AT_dwo_name, DW_AT_dwo_id,
2465 // DW_AT_addr_base, DW_AT_ranges_base.
2466 DwarfCompileUnit &DwarfDebug::constructSkeletonCU(const DwarfCompileUnit &CU) {
2468 auto OwnedUnit = make_unique<DwarfCompileUnit>(
2469 CU.getUniqueID(), CU.getCUNode(), Asm, this, &SkeletonHolder);
2470 DwarfCompileUnit &NewCU = *OwnedUnit;
2471 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoSection(),
2472 DwarfInfoSectionSym);
2474 NewCU.initStmtList(DwarfLineSectionSym);
2476 initSkeletonUnit(CU, NewCU.getUnitDie(), std::move(OwnedUnit));
2481 // This DIE has the following attributes: DW_AT_comp_dir, DW_AT_dwo_name,
2483 DwarfTypeUnit &DwarfDebug::constructSkeletonTU(DwarfTypeUnit &TU) {
2484 DwarfCompileUnit &CU = static_cast<DwarfCompileUnit &>(
2485 *SkeletonHolder.getUnits()[TU.getCU().getUniqueID()]);
2487 auto OwnedUnit = make_unique<DwarfTypeUnit>(TU.getUniqueID(), CU, Asm, this,
2489 DwarfTypeUnit &NewTU = *OwnedUnit;
2490 NewTU.setTypeSignature(TU.getTypeSignature());
2491 NewTU.setType(nullptr);
2493 Asm->getObjFileLowering().getDwarfTypesSection(TU.getTypeSignature()));
2495 initSkeletonUnit(TU, NewTU.getUnitDie(), std::move(OwnedUnit));
2499 // Emit the .debug_info.dwo section for separated dwarf. This contains the
2500 // compile units that would normally be in debug_info.
2501 void DwarfDebug::emitDebugInfoDWO() {
2502 assert(useSplitDwarf() && "No split dwarf debug info?");
2503 // Don't pass an abbrev symbol, using a constant zero instead so as not to
2504 // emit relocations into the dwo file.
2505 InfoHolder.emitUnits(this, /* AbbrevSymbol */ nullptr);
2508 // Emit the .debug_abbrev.dwo section for separated dwarf. This contains the
2509 // abbreviations for the .debug_info.dwo section.
2510 void DwarfDebug::emitDebugAbbrevDWO() {
2511 assert(useSplitDwarf() && "No split dwarf?");
2512 InfoHolder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevDWOSection());
2515 void DwarfDebug::emitDebugLineDWO() {
2516 assert(useSplitDwarf() && "No split dwarf?");
2517 Asm->OutStreamer.SwitchSection(
2518 Asm->getObjFileLowering().getDwarfLineDWOSection());
2519 SplitTypeUnitFileTable.Emit(Asm->OutStreamer);
2522 // Emit the .debug_str.dwo section for separated dwarf. This contains the
2523 // string section and is identical in format to traditional .debug_str
2525 void DwarfDebug::emitDebugStrDWO() {
2526 assert(useSplitDwarf() && "No split dwarf?");
2527 const MCSection *OffSec =
2528 Asm->getObjFileLowering().getDwarfStrOffDWOSection();
2529 const MCSymbol *StrSym = DwarfStrSectionSym;
2530 InfoHolder.emitStrings(Asm->getObjFileLowering().getDwarfStrDWOSection(),
2534 MCDwarfDwoLineTable *DwarfDebug::getDwoLineTable(const DwarfCompileUnit &CU) {
2535 if (!useSplitDwarf())
2538 SplitTypeUnitFileTable.setCompilationDir(CU.getCUNode().getDirectory());
2539 return &SplitTypeUnitFileTable;
2542 static uint64_t makeTypeSignature(StringRef Identifier) {
2544 Hash.update(Identifier);
2545 // ... take the least significant 8 bytes and return those. Our MD5
2546 // implementation always returns its results in little endian, swap bytes
2548 MD5::MD5Result Result;
2550 return *reinterpret_cast<support::ulittle64_t *>(Result + 8);
2553 void DwarfDebug::addDwarfTypeUnitType(DwarfCompileUnit &CU,
2554 StringRef Identifier, DIE &RefDie,
2555 DICompositeType CTy) {
2556 // Fast path if we're building some type units and one has already used the
2557 // address pool we know we're going to throw away all this work anyway, so
2558 // don't bother building dependent types.
2559 if (!TypeUnitsUnderConstruction.empty() && AddrPool.hasBeenUsed())
2562 const DwarfTypeUnit *&TU = DwarfTypeUnits[CTy];
2564 CU.addDIETypeSignature(RefDie, *TU);
2568 bool TopLevelType = TypeUnitsUnderConstruction.empty();
2569 AddrPool.resetUsedFlag();
2571 auto OwnedUnit = make_unique<DwarfTypeUnit>(
2572 InfoHolder.getUnits().size() + TypeUnitsUnderConstruction.size(), CU, Asm,
2573 this, &InfoHolder, getDwoLineTable(CU));
2574 DwarfTypeUnit &NewTU = *OwnedUnit;
2575 DIE &UnitDie = NewTU.getUnitDie();
2577 TypeUnitsUnderConstruction.push_back(
2578 std::make_pair(std::move(OwnedUnit), CTy));
2580 NewTU.addUInt(UnitDie, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
2583 uint64_t Signature = makeTypeSignature(Identifier);
2584 NewTU.setTypeSignature(Signature);
2586 if (useSplitDwarf())
2587 NewTU.initSection(Asm->getObjFileLowering().getDwarfTypesDWOSection(),
2588 DwarfTypesDWOSectionSym);
2590 CU.applyStmtList(UnitDie);
2592 Asm->getObjFileLowering().getDwarfTypesSection(Signature));
2595 NewTU.setType(NewTU.createTypeDIE(CTy));
2598 auto TypeUnitsToAdd = std::move(TypeUnitsUnderConstruction);
2599 TypeUnitsUnderConstruction.clear();
2601 // Types referencing entries in the address table cannot be placed in type
2603 if (AddrPool.hasBeenUsed()) {
2605 // Remove all the types built while building this type.
2606 // This is pessimistic as some of these types might not be dependent on
2607 // the type that used an address.
2608 for (const auto &TU : TypeUnitsToAdd)
2609 DwarfTypeUnits.erase(TU.second);
2611 // Construct this type in the CU directly.
2612 // This is inefficient because all the dependent types will be rebuilt
2613 // from scratch, including building them in type units, discovering that
2614 // they depend on addresses, throwing them out and rebuilding them.
2615 CU.constructTypeDIE(RefDie, CTy);
2619 // If the type wasn't dependent on fission addresses, finish adding the type
2620 // and all its dependent types.
2621 for (auto &TU : TypeUnitsToAdd) {
2622 if (useSplitDwarf())
2623 TU.first->setSkeleton(constructSkeletonTU(*TU.first));
2624 InfoHolder.addUnit(std::move(TU.first));
2627 CU.addDIETypeSignature(RefDie, NewTU);
2630 void DwarfDebug::attachLowHighPC(DwarfCompileUnit &Unit, DIE &D,
2631 MCSymbol *Begin, MCSymbol *End) {
2632 assert(Begin && "Begin label should not be null!");
2633 assert(End && "End label should not be null!");
2634 assert(Begin->isDefined() && "Invalid starting label");
2635 assert(End->isDefined() && "Invalid end label");
2637 Unit.addLabelAddress(D, dwarf::DW_AT_low_pc, Begin);
2638 if (DwarfVersion < 4)
2639 Unit.addLabelAddress(D, dwarf::DW_AT_high_pc, End);
2641 Unit.addLabelDelta(D, dwarf::DW_AT_high_pc, End, Begin);
2644 // Accelerator table mutators - add each name along with its companion
2645 // DIE to the proper table while ensuring that the name that we're going
2646 // to reference is in the string table. We do this since the names we
2647 // add may not only be identical to the names in the DIE.
2648 void DwarfDebug::addAccelName(StringRef Name, const DIE &Die) {
2649 if (!useDwarfAccelTables())
2651 AccelNames.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2655 void DwarfDebug::addAccelObjC(StringRef Name, const DIE &Die) {
2656 if (!useDwarfAccelTables())
2658 AccelObjC.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2662 void DwarfDebug::addAccelNamespace(StringRef Name, const DIE &Die) {
2663 if (!useDwarfAccelTables())
2665 AccelNamespace.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2669 void DwarfDebug::addAccelType(StringRef Name, const DIE &Die, char Flags) {
2670 if (!useDwarfAccelTables())
2672 AccelTypes.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),