1 //===-- llvm/CodeGen/DwarfDebug.cpp - Dwarf Debug Framework ---------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file contains support for writing dwarf debug info into asm files.
12 //===----------------------------------------------------------------------===//
14 #include "ByteStreamer.h"
15 #include "DwarfDebug.h"
18 #include "DwarfUnit.h"
19 #include "llvm/ADT/STLExtras.h"
20 #include "llvm/ADT/Statistic.h"
21 #include "llvm/ADT/StringExtras.h"
22 #include "llvm/ADT/Triple.h"
23 #include "llvm/CodeGen/MachineFunction.h"
24 #include "llvm/CodeGen/MachineModuleInfo.h"
25 #include "llvm/IR/Constants.h"
26 #include "llvm/IR/DIBuilder.h"
27 #include "llvm/IR/DataLayout.h"
28 #include "llvm/IR/DebugInfo.h"
29 #include "llvm/IR/Instructions.h"
30 #include "llvm/IR/Module.h"
31 #include "llvm/IR/ValueHandle.h"
32 #include "llvm/MC/MCAsmInfo.h"
33 #include "llvm/MC/MCSection.h"
34 #include "llvm/MC/MCStreamer.h"
35 #include "llvm/MC/MCSymbol.h"
36 #include "llvm/Support/CommandLine.h"
37 #include "llvm/Support/Debug.h"
38 #include "llvm/Support/Dwarf.h"
39 #include "llvm/Support/Endian.h"
40 #include "llvm/Support/ErrorHandling.h"
41 #include "llvm/Support/FormattedStream.h"
42 #include "llvm/Support/LEB128.h"
43 #include "llvm/Support/MD5.h"
44 #include "llvm/Support/Path.h"
45 #include "llvm/Support/Timer.h"
46 #include "llvm/Target/TargetFrameLowering.h"
47 #include "llvm/Target/TargetLoweringObjectFile.h"
48 #include "llvm/Target/TargetMachine.h"
49 #include "llvm/Target/TargetOptions.h"
50 #include "llvm/Target/TargetRegisterInfo.h"
51 #include "llvm/Target/TargetSubtargetInfo.h"
54 #define DEBUG_TYPE "dwarfdebug"
57 DisableDebugInfoPrinting("disable-debug-info-print", cl::Hidden,
58 cl::desc("Disable debug info printing"));
60 static cl::opt<bool> UnknownLocations(
61 "use-unknown-locations", cl::Hidden,
62 cl::desc("Make an absence of debug location information explicit."),
66 GenerateGnuPubSections("generate-gnu-dwarf-pub-sections", cl::Hidden,
67 cl::desc("Generate GNU-style pubnames and pubtypes"),
70 static cl::opt<bool> GenerateARangeSection("generate-arange-section",
72 cl::desc("Generate dwarf aranges"),
76 enum DefaultOnOff { Default, Enable, Disable };
79 static cl::opt<DefaultOnOff>
80 DwarfAccelTables("dwarf-accel-tables", cl::Hidden,
81 cl::desc("Output prototype dwarf accelerator tables."),
82 cl::values(clEnumVal(Default, "Default for platform"),
83 clEnumVal(Enable, "Enabled"),
84 clEnumVal(Disable, "Disabled"), clEnumValEnd),
87 static cl::opt<DefaultOnOff>
88 SplitDwarf("split-dwarf", cl::Hidden,
89 cl::desc("Output DWARF5 split debug info."),
90 cl::values(clEnumVal(Default, "Default for platform"),
91 clEnumVal(Enable, "Enabled"),
92 clEnumVal(Disable, "Disabled"), clEnumValEnd),
95 static cl::opt<DefaultOnOff>
96 DwarfPubSections("generate-dwarf-pub-sections", cl::Hidden,
97 cl::desc("Generate DWARF pubnames and pubtypes sections"),
98 cl::values(clEnumVal(Default, "Default for platform"),
99 clEnumVal(Enable, "Enabled"),
100 clEnumVal(Disable, "Disabled"), clEnumValEnd),
103 static const char *const DWARFGroupName = "DWARF Emission";
104 static const char *const DbgTimerName = "DWARF Debug Writer";
106 //===----------------------------------------------------------------------===//
108 /// resolve - Look in the DwarfDebug map for the MDNode that
109 /// corresponds to the reference.
110 template <typename T> T DbgVariable::resolve(DIRef<T> Ref) const {
111 return DD->resolve(Ref);
114 bool DbgVariable::isBlockByrefVariable() const {
115 assert(Var.isVariable() && "Invalid complex DbgVariable!");
116 return Var.isBlockByrefVariable(DD->getTypeIdentifierMap());
119 DIType DbgVariable::getType() const {
120 DIType Ty = Var.getType().resolve(DD->getTypeIdentifierMap());
121 // FIXME: isBlockByrefVariable should be reformulated in terms of complex
122 // addresses instead.
123 if (Var.isBlockByrefVariable(DD->getTypeIdentifierMap())) {
124 /* Byref variables, in Blocks, are declared by the programmer as
125 "SomeType VarName;", but the compiler creates a
126 __Block_byref_x_VarName struct, and gives the variable VarName
127 either the struct, or a pointer to the struct, as its type. This
128 is necessary for various behind-the-scenes things the compiler
129 needs to do with by-reference variables in blocks.
131 However, as far as the original *programmer* is concerned, the
132 variable should still have type 'SomeType', as originally declared.
134 The following function dives into the __Block_byref_x_VarName
135 struct to find the original type of the variable. This will be
136 passed back to the code generating the type for the Debug
137 Information Entry for the variable 'VarName'. 'VarName' will then
138 have the original type 'SomeType' in its debug information.
140 The original type 'SomeType' will be the type of the field named
141 'VarName' inside the __Block_byref_x_VarName struct.
143 NOTE: In order for this to not completely fail on the debugger
144 side, the Debug Information Entry for the variable VarName needs to
145 have a DW_AT_location that tells the debugger how to unwind through
146 the pointers and __Block_byref_x_VarName struct to find the actual
147 value of the variable. The function addBlockByrefType does this. */
149 uint16_t tag = Ty.getTag();
151 if (tag == dwarf::DW_TAG_pointer_type)
152 subType = resolve(DIDerivedType(Ty).getTypeDerivedFrom());
154 DIArray Elements = DICompositeType(subType).getElements();
155 for (unsigned i = 0, N = Elements.getNumElements(); i < N; ++i) {
156 DIDerivedType DT(Elements.getElement(i));
157 if (getName() == DT.getName())
158 return (resolve(DT.getTypeDerivedFrom()));
164 static LLVM_CONSTEXPR DwarfAccelTable::Atom TypeAtoms[] = {
165 DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset, dwarf::DW_FORM_data4),
166 DwarfAccelTable::Atom(dwarf::DW_ATOM_die_tag, dwarf::DW_FORM_data2),
167 DwarfAccelTable::Atom(dwarf::DW_ATOM_type_flags, dwarf::DW_FORM_data1)};
169 DwarfDebug::DwarfDebug(AsmPrinter *A, Module *M)
170 : Asm(A), MMI(Asm->MMI), FirstCU(nullptr), PrevLabel(nullptr),
171 GlobalRangeCount(0), InfoHolder(A, "info_string", DIEValueAllocator),
172 UsedNonDefaultText(false),
173 SkeletonHolder(A, "skel_string", DIEValueAllocator),
174 AccelNames(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
175 dwarf::DW_FORM_data4)),
176 AccelObjC(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
177 dwarf::DW_FORM_data4)),
178 AccelNamespace(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
179 dwarf::DW_FORM_data4)),
180 AccelTypes(TypeAtoms) {
182 DwarfInfoSectionSym = DwarfAbbrevSectionSym = DwarfStrSectionSym = nullptr;
183 DwarfDebugRangeSectionSym = DwarfDebugLocSectionSym = nullptr;
184 DwarfLineSectionSym = nullptr;
185 DwarfAddrSectionSym = nullptr;
186 DwarfAbbrevDWOSectionSym = DwarfStrDWOSectionSym = nullptr;
187 FunctionBeginSym = FunctionEndSym = nullptr;
191 // Turn on accelerator tables for Darwin by default, pubnames by
192 // default for non-Darwin, and handle split dwarf.
193 bool IsDarwin = Triple(A->getTargetTriple()).isOSDarwin();
195 if (DwarfAccelTables == Default)
196 HasDwarfAccelTables = IsDarwin;
198 HasDwarfAccelTables = DwarfAccelTables == Enable;
200 if (SplitDwarf == Default)
201 HasSplitDwarf = false;
203 HasSplitDwarf = SplitDwarf == Enable;
205 if (DwarfPubSections == Default)
206 HasDwarfPubSections = !IsDarwin;
208 HasDwarfPubSections = DwarfPubSections == Enable;
210 unsigned DwarfVersionNumber = Asm->TM.Options.MCOptions.DwarfVersion;
211 DwarfVersion = DwarfVersionNumber ? DwarfVersionNumber
212 : MMI->getModule()->getDwarfVersion();
214 Asm->OutStreamer.getContext().setDwarfVersion(DwarfVersion);
217 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
222 // Define out of line so we don't have to include DwarfUnit.h in DwarfDebug.h.
223 DwarfDebug::~DwarfDebug() { }
225 // Switch to the specified MCSection and emit an assembler
226 // temporary label to it if SymbolStem is specified.
227 static MCSymbol *emitSectionSym(AsmPrinter *Asm, const MCSection *Section,
228 const char *SymbolStem = nullptr) {
229 Asm->OutStreamer.SwitchSection(Section);
233 MCSymbol *TmpSym = Asm->GetTempSymbol(SymbolStem);
234 Asm->OutStreamer.EmitLabel(TmpSym);
238 static bool isObjCClass(StringRef Name) {
239 return Name.startswith("+") || Name.startswith("-");
242 static bool hasObjCCategory(StringRef Name) {
243 if (!isObjCClass(Name))
246 return Name.find(") ") != StringRef::npos;
249 static void getObjCClassCategory(StringRef In, StringRef &Class,
250 StringRef &Category) {
251 if (!hasObjCCategory(In)) {
252 Class = In.slice(In.find('[') + 1, In.find(' '));
257 Class = In.slice(In.find('[') + 1, In.find('('));
258 Category = In.slice(In.find('[') + 1, In.find(' '));
262 static StringRef getObjCMethodName(StringRef In) {
263 return In.slice(In.find(' ') + 1, In.find(']'));
266 // Helper for sorting sections into a stable output order.
267 static bool SectionSort(const MCSection *A, const MCSection *B) {
268 std::string LA = (A ? A->getLabelBeginName() : "");
269 std::string LB = (B ? B->getLabelBeginName() : "");
273 // Add the various names to the Dwarf accelerator table names.
274 // TODO: Determine whether or not we should add names for programs
275 // that do not have a DW_AT_name or DW_AT_linkage_name field - this
276 // is only slightly different than the lookup of non-standard ObjC names.
277 void DwarfDebug::addSubprogramNames(DISubprogram SP, DIE &Die) {
278 if (!SP.isDefinition())
280 addAccelName(SP.getName(), Die);
282 // If the linkage name is different than the name, go ahead and output
283 // that as well into the name table.
284 if (SP.getLinkageName() != "" && SP.getName() != SP.getLinkageName())
285 addAccelName(SP.getLinkageName(), Die);
287 // If this is an Objective-C selector name add it to the ObjC accelerator
289 if (isObjCClass(SP.getName())) {
290 StringRef Class, Category;
291 getObjCClassCategory(SP.getName(), Class, Category);
292 addAccelObjC(Class, Die);
294 addAccelObjC(Category, Die);
295 // Also add the base method name to the name table.
296 addAccelName(getObjCMethodName(SP.getName()), Die);
300 /// isSubprogramContext - Return true if Context is either a subprogram
301 /// or another context nested inside a subprogram.
302 bool DwarfDebug::isSubprogramContext(const MDNode *Context) {
305 DIDescriptor D(Context);
306 if (D.isSubprogram())
309 return isSubprogramContext(resolve(DIType(Context).getContext()));
313 // Find DIE for the given subprogram and attach appropriate DW_AT_low_pc
314 // and DW_AT_high_pc attributes. If there are global variables in this
315 // scope then create and insert DIEs for these variables.
316 DIE &DwarfDebug::updateSubprogramScopeDIE(DwarfCompileUnit &SPCU,
318 DIE *SPDie = SPCU.getOrCreateSubprogramDIE(SP);
320 attachLowHighPC(SPCU, *SPDie, FunctionBeginSym, FunctionEndSym);
322 const TargetRegisterInfo *RI = Asm->TM.getSubtargetImpl()->getRegisterInfo();
323 MachineLocation Location(RI->getFrameRegister(*Asm->MF));
324 SPCU.addAddress(*SPDie, dwarf::DW_AT_frame_base, Location);
326 // Add name to the name table, we do this here because we're guaranteed
327 // to have concrete versions of our DW_TAG_subprogram nodes.
328 addSubprogramNames(SP, *SPDie);
333 /// Check whether we should create a DIE for the given Scope, return true
334 /// if we don't create a DIE (the corresponding DIE is null).
335 bool DwarfDebug::isLexicalScopeDIENull(LexicalScope *Scope) {
336 if (Scope->isAbstractScope())
339 // We don't create a DIE if there is no Range.
340 const SmallVectorImpl<InsnRange> &Ranges = Scope->getRanges();
344 if (Ranges.size() > 1)
347 // We don't create a DIE if we have a single Range and the end label
349 SmallVectorImpl<InsnRange>::const_iterator RI = Ranges.begin();
350 MCSymbol *End = getLabelAfterInsn(RI->second);
354 static void addSectionLabel(AsmPrinter &Asm, DwarfUnit &U, DIE &D,
355 dwarf::Attribute A, const MCSymbol *L,
356 const MCSymbol *Sec) {
357 if (Asm.MAI->doesDwarfUseRelocationsAcrossSections())
358 U.addSectionLabel(D, A, L);
360 U.addSectionDelta(D, A, L, Sec);
363 void DwarfDebug::addScopeRangeList(DwarfCompileUnit &TheCU, DIE &ScopeDIE,
364 const SmallVectorImpl<InsnRange> &Range) {
365 // Emit offset in .debug_range as a relocatable label. emitDIE will handle
366 // emitting it appropriately.
367 MCSymbol *RangeSym = Asm->GetTempSymbol("debug_ranges", GlobalRangeCount++);
369 // Under fission, ranges are specified by constant offsets relative to the
370 // CU's DW_AT_GNU_ranges_base.
372 TheCU.addSectionDelta(ScopeDIE, dwarf::DW_AT_ranges, RangeSym,
373 DwarfDebugRangeSectionSym);
375 addSectionLabel(*Asm, TheCU, ScopeDIE, dwarf::DW_AT_ranges, RangeSym,
376 DwarfDebugRangeSectionSym);
378 RangeSpanList List(RangeSym);
379 for (const InsnRange &R : Range) {
380 RangeSpan Span(getLabelBeforeInsn(R.first), getLabelAfterInsn(R.second));
381 List.addRange(std::move(Span));
384 // Add the range list to the set of ranges to be emitted.
385 TheCU.addRangeList(std::move(List));
388 void DwarfDebug::attachRangesOrLowHighPC(DwarfCompileUnit &TheCU, DIE &Die,
389 const SmallVectorImpl<InsnRange> &Ranges) {
390 assert(!Ranges.empty());
391 if (Ranges.size() == 1)
392 attachLowHighPC(TheCU, Die, getLabelBeforeInsn(Ranges.front().first),
393 getLabelAfterInsn(Ranges.front().second));
395 addScopeRangeList(TheCU, Die, Ranges);
398 // Construct new DW_TAG_lexical_block for this scope and attach
399 // DW_AT_low_pc/DW_AT_high_pc labels.
401 DwarfDebug::constructLexicalScopeDIE(DwarfCompileUnit &TheCU,
402 LexicalScope *Scope) {
403 if (isLexicalScopeDIENull(Scope))
406 auto ScopeDIE = make_unique<DIE>(dwarf::DW_TAG_lexical_block);
407 if (Scope->isAbstractScope())
410 attachRangesOrLowHighPC(TheCU, *ScopeDIE, Scope->getRanges());
415 // This scope represents inlined body of a function. Construct DIE to
416 // represent this concrete inlined copy of the function.
418 DwarfDebug::constructInlinedScopeDIE(DwarfCompileUnit &TheCU,
419 LexicalScope *Scope) {
420 assert(Scope->getScopeNode());
421 DIScope DS(Scope->getScopeNode());
422 DISubprogram InlinedSP = getDISubprogram(DS);
423 // Find the subprogram's DwarfCompileUnit in the SPMap in case the subprogram
424 // was inlined from another compile unit.
425 DIE *OriginDIE = AbstractSPDies[InlinedSP];
426 assert(OriginDIE && "Unable to find original DIE for an inlined subprogram.");
428 auto ScopeDIE = make_unique<DIE>(dwarf::DW_TAG_inlined_subroutine);
429 TheCU.addDIEEntry(*ScopeDIE, dwarf::DW_AT_abstract_origin, *OriginDIE);
431 attachRangesOrLowHighPC(TheCU, *ScopeDIE, Scope->getRanges());
433 InlinedSubprogramDIEs.insert(OriginDIE);
435 // Add the call site information to the DIE.
436 DILocation DL(Scope->getInlinedAt());
437 TheCU.addUInt(*ScopeDIE, dwarf::DW_AT_call_file, None,
438 TheCU.getOrCreateSourceID(DL.getFilename(), DL.getDirectory()));
439 TheCU.addUInt(*ScopeDIE, dwarf::DW_AT_call_line, None, DL.getLineNumber());
441 // Add name to the name table, we do this here because we're guaranteed
442 // to have concrete versions of our DW_TAG_inlined_subprogram nodes.
443 addSubprogramNames(InlinedSP, *ScopeDIE);
448 static std::unique_ptr<DIE> constructVariableDIE(DwarfCompileUnit &TheCU,
450 const LexicalScope &Scope,
451 DIE *&ObjectPointer) {
452 auto Var = TheCU.constructVariableDIE(DV, Scope.isAbstractScope());
453 if (DV.isObjectPointer())
454 ObjectPointer = Var.get();
458 DIE *DwarfDebug::createScopeChildrenDIE(
459 DwarfCompileUnit &TheCU, LexicalScope *Scope,
460 SmallVectorImpl<std::unique_ptr<DIE>> &Children) {
461 DIE *ObjectPointer = nullptr;
463 // Collect arguments for current function.
464 if (LScopes.isCurrentFunctionScope(Scope)) {
465 for (DbgVariable *ArgDV : CurrentFnArguments)
468 constructVariableDIE(TheCU, *ArgDV, *Scope, ObjectPointer));
470 // If this is a variadic function, add an unspecified parameter.
471 DISubprogram SP(Scope->getScopeNode());
472 DITypeArray FnArgs = SP.getType().getTypeArray();
473 // If we have a single element of null, it is a function that returns void.
474 // If we have more than one elements and the last one is null, it is a
475 // variadic function.
476 if (FnArgs.getNumElements() > 1 &&
477 !FnArgs.getElement(FnArgs.getNumElements() - 1))
479 make_unique<DIE>(dwarf::DW_TAG_unspecified_parameters));
482 // Collect lexical scope children first.
483 for (DbgVariable *DV : ScopeVariables.lookup(Scope))
484 Children.push_back(constructVariableDIE(TheCU, *DV, *Scope, ObjectPointer));
486 for (LexicalScope *LS : Scope->getChildren())
487 if (std::unique_ptr<DIE> Nested = constructScopeDIE(TheCU, LS))
488 Children.push_back(std::move(Nested));
489 return ObjectPointer;
492 void DwarfDebug::createAndAddScopeChildren(DwarfCompileUnit &TheCU,
493 LexicalScope *Scope, DIE &ScopeDIE) {
494 // We create children when the scope DIE is not null.
495 SmallVector<std::unique_ptr<DIE>, 8> Children;
496 if (DIE *ObjectPointer = createScopeChildrenDIE(TheCU, Scope, Children))
497 TheCU.addDIEEntry(ScopeDIE, dwarf::DW_AT_object_pointer, *ObjectPointer);
500 for (auto &I : Children)
501 ScopeDIE.addChild(std::move(I));
504 void DwarfDebug::constructAbstractSubprogramScopeDIE(DwarfCompileUnit &TheCU,
505 LexicalScope *Scope) {
506 assert(Scope && Scope->getScopeNode());
507 assert(Scope->isAbstractScope());
508 assert(!Scope->getInlinedAt());
510 DISubprogram SP(Scope->getScopeNode());
512 ProcessedSPNodes.insert(SP);
514 DIE *&AbsDef = AbstractSPDies[SP];
518 // Find the subprogram's DwarfCompileUnit in the SPMap in case the subprogram
519 // was inlined from another compile unit.
520 DwarfCompileUnit &SPCU = *SPMap[SP];
523 // Some of this is duplicated from DwarfUnit::getOrCreateSubprogramDIE, with
524 // the important distinction that the DIDescriptor is not associated with the
525 // DIE (since the DIDescriptor will be associated with the concrete DIE, if
526 // any). It could be refactored to some common utility function.
527 if (DISubprogram SPDecl = SP.getFunctionDeclaration()) {
528 ContextDIE = &SPCU.getUnitDie();
529 SPCU.getOrCreateSubprogramDIE(SPDecl);
531 ContextDIE = SPCU.getOrCreateContextDIE(resolve(SP.getContext()));
533 // Passing null as the associated DIDescriptor because the abstract definition
534 // shouldn't be found by lookup.
535 AbsDef = &SPCU.createAndAddDIE(dwarf::DW_TAG_subprogram, *ContextDIE,
537 SPCU.applySubprogramAttributesToDefinition(SP, *AbsDef);
539 SPCU.addUInt(*AbsDef, dwarf::DW_AT_inline, None, dwarf::DW_INL_inlined);
540 createAndAddScopeChildren(SPCU, Scope, *AbsDef);
543 DIE &DwarfDebug::constructSubprogramScopeDIE(DwarfCompileUnit &TheCU,
544 LexicalScope *Scope) {
545 assert(Scope && Scope->getScopeNode());
546 assert(!Scope->getInlinedAt());
547 assert(!Scope->isAbstractScope());
548 DISubprogram Sub(Scope->getScopeNode());
550 assert(Sub.isSubprogram());
552 ProcessedSPNodes.insert(Sub);
554 DIE &ScopeDIE = updateSubprogramScopeDIE(TheCU, Sub);
556 createAndAddScopeChildren(TheCU, Scope, ScopeDIE);
561 // Construct a DIE for this scope.
562 std::unique_ptr<DIE> DwarfDebug::constructScopeDIE(DwarfCompileUnit &TheCU,
563 LexicalScope *Scope) {
564 if (!Scope || !Scope->getScopeNode())
567 DIScope DS(Scope->getScopeNode());
569 assert((Scope->getInlinedAt() || !DS.isSubprogram()) &&
570 "Only handle inlined subprograms here, use "
571 "constructSubprogramScopeDIE for non-inlined "
574 SmallVector<std::unique_ptr<DIE>, 8> Children;
576 // We try to create the scope DIE first, then the children DIEs. This will
577 // avoid creating un-used children then removing them later when we find out
578 // the scope DIE is null.
579 std::unique_ptr<DIE> ScopeDIE;
580 if (Scope->getParent() && DS.isSubprogram()) {
581 ScopeDIE = constructInlinedScopeDIE(TheCU, Scope);
584 // We create children when the scope DIE is not null.
585 createScopeChildrenDIE(TheCU, Scope, Children);
587 // Early exit when we know the scope DIE is going to be null.
588 if (isLexicalScopeDIENull(Scope))
591 // We create children here when we know the scope DIE is not going to be
592 // null and the children will be added to the scope DIE.
593 createScopeChildrenDIE(TheCU, Scope, Children);
595 // There is no need to emit empty lexical block DIE.
596 std::pair<ImportedEntityMap::const_iterator,
597 ImportedEntityMap::const_iterator> Range =
598 std::equal_range(ScopesWithImportedEntities.begin(),
599 ScopesWithImportedEntities.end(),
600 std::pair<const MDNode *, const MDNode *>(DS, nullptr),
602 if (Children.empty() && Range.first == Range.second)
604 ScopeDIE = constructLexicalScopeDIE(TheCU, Scope);
605 assert(ScopeDIE && "Scope DIE should not be null.");
606 for (ImportedEntityMap::const_iterator i = Range.first; i != Range.second;
608 constructImportedEntityDIE(TheCU, i->second, *ScopeDIE);
612 for (auto &I : Children)
613 ScopeDIE->addChild(std::move(I));
618 void DwarfDebug::addGnuPubAttributes(DwarfUnit &U, DIE &D) const {
619 if (!GenerateGnuPubSections)
622 U.addFlag(D, dwarf::DW_AT_GNU_pubnames);
625 // Create new DwarfCompileUnit for the given metadata node with tag
626 // DW_TAG_compile_unit.
627 DwarfCompileUnit &DwarfDebug::constructDwarfCompileUnit(DICompileUnit DIUnit) {
628 StringRef FN = DIUnit.getFilename();
629 CompilationDir = DIUnit.getDirectory();
631 auto OwnedUnit = make_unique<DwarfCompileUnit>(
632 InfoHolder.getUnits().size(), DIUnit, Asm, this, &InfoHolder);
633 DwarfCompileUnit &NewCU = *OwnedUnit;
634 DIE &Die = NewCU.getUnitDie();
635 InfoHolder.addUnit(std::move(OwnedUnit));
637 // LTO with assembly output shares a single line table amongst multiple CUs.
638 // To avoid the compilation directory being ambiguous, let the line table
639 // explicitly describe the directory of all files, never relying on the
640 // compilation directory.
641 if (!Asm->OutStreamer.hasRawTextSupport() || SingleCU)
642 Asm->OutStreamer.getContext().setMCLineTableCompilationDir(
643 NewCU.getUniqueID(), CompilationDir);
645 NewCU.addString(Die, dwarf::DW_AT_producer, DIUnit.getProducer());
646 NewCU.addUInt(Die, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
647 DIUnit.getLanguage());
648 NewCU.addString(Die, dwarf::DW_AT_name, FN);
650 if (!useSplitDwarf()) {
651 NewCU.initStmtList(DwarfLineSectionSym);
653 // If we're using split dwarf the compilation dir is going to be in the
654 // skeleton CU and so we don't need to duplicate it here.
655 if (!CompilationDir.empty())
656 NewCU.addString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
658 addGnuPubAttributes(NewCU, Die);
661 if (DIUnit.isOptimized())
662 NewCU.addFlag(Die, dwarf::DW_AT_APPLE_optimized);
664 StringRef Flags = DIUnit.getFlags();
666 NewCU.addString(Die, dwarf::DW_AT_APPLE_flags, Flags);
668 if (unsigned RVer = DIUnit.getRunTimeVersion())
669 NewCU.addUInt(Die, dwarf::DW_AT_APPLE_major_runtime_vers,
670 dwarf::DW_FORM_data1, RVer);
675 if (useSplitDwarf()) {
676 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoDWOSection(),
677 DwarfInfoDWOSectionSym);
678 NewCU.setSkeleton(constructSkeletonCU(NewCU));
680 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoSection(),
681 DwarfInfoSectionSym);
683 CUMap.insert(std::make_pair(DIUnit, &NewCU));
684 CUDieMap.insert(std::make_pair(&Die, &NewCU));
688 void DwarfDebug::constructImportedEntityDIE(DwarfCompileUnit &TheCU,
690 DIImportedEntity Module(N);
691 assert(Module.Verify());
692 if (DIE *D = TheCU.getOrCreateContextDIE(Module.getContext()))
693 constructImportedEntityDIE(TheCU, Module, *D);
696 void DwarfDebug::constructImportedEntityDIE(DwarfCompileUnit &TheCU,
697 const MDNode *N, DIE &Context) {
698 DIImportedEntity Module(N);
699 assert(Module.Verify());
700 return constructImportedEntityDIE(TheCU, Module, Context);
703 void DwarfDebug::constructImportedEntityDIE(DwarfCompileUnit &TheCU,
704 const DIImportedEntity &Module,
706 assert(Module.Verify() &&
707 "Use one of the MDNode * overloads to handle invalid metadata");
708 DIE &IMDie = TheCU.createAndAddDIE(Module.getTag(), Context, Module);
710 DIDescriptor Entity = resolve(Module.getEntity());
711 if (Entity.isNameSpace())
712 EntityDie = TheCU.getOrCreateNameSpace(DINameSpace(Entity));
713 else if (Entity.isSubprogram())
714 EntityDie = TheCU.getOrCreateSubprogramDIE(DISubprogram(Entity));
715 else if (Entity.isType())
716 EntityDie = TheCU.getOrCreateTypeDIE(DIType(Entity));
718 EntityDie = TheCU.getDIE(Entity);
719 TheCU.addSourceLine(IMDie, Module.getLineNumber(),
720 Module.getContext().getFilename(),
721 Module.getContext().getDirectory());
722 TheCU.addDIEEntry(IMDie, dwarf::DW_AT_import, *EntityDie);
723 StringRef Name = Module.getName();
725 TheCU.addString(IMDie, dwarf::DW_AT_name, Name);
728 // Emit all Dwarf sections that should come prior to the content. Create
729 // global DIEs and emit initial debug info sections. This is invoked by
730 // the target AsmPrinter.
731 void DwarfDebug::beginModule() {
732 if (DisableDebugInfoPrinting)
735 const Module *M = MMI->getModule();
737 FunctionDIs = makeSubprogramMap(*M);
739 // If module has named metadata anchors then use them, otherwise scan the
740 // module using debug info finder to collect debug info.
741 NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
744 TypeIdentifierMap = generateDITypeIdentifierMap(CU_Nodes);
746 // Emit initial sections so we can reference labels later.
749 SingleCU = CU_Nodes->getNumOperands() == 1;
751 for (MDNode *N : CU_Nodes->operands()) {
752 DICompileUnit CUNode(N);
753 DwarfCompileUnit &CU = constructDwarfCompileUnit(CUNode);
754 DIArray ImportedEntities = CUNode.getImportedEntities();
755 for (unsigned i = 0, e = ImportedEntities.getNumElements(); i != e; ++i)
756 ScopesWithImportedEntities.push_back(std::make_pair(
757 DIImportedEntity(ImportedEntities.getElement(i)).getContext(),
758 ImportedEntities.getElement(i)));
759 std::sort(ScopesWithImportedEntities.begin(),
760 ScopesWithImportedEntities.end(), less_first());
761 DIArray GVs = CUNode.getGlobalVariables();
762 for (unsigned i = 0, e = GVs.getNumElements(); i != e; ++i)
763 CU.createGlobalVariableDIE(DIGlobalVariable(GVs.getElement(i)));
764 DIArray SPs = CUNode.getSubprograms();
765 for (unsigned i = 0, e = SPs.getNumElements(); i != e; ++i)
766 SPMap.insert(std::make_pair(SPs.getElement(i), &CU));
767 DIArray EnumTypes = CUNode.getEnumTypes();
768 for (unsigned i = 0, e = EnumTypes.getNumElements(); i != e; ++i) {
769 DIType Ty(EnumTypes.getElement(i));
770 // The enum types array by design contains pointers to
771 // MDNodes rather than DIRefs. Unique them here.
772 DIType UniqueTy(resolve(Ty.getRef()));
773 CU.getOrCreateTypeDIE(UniqueTy);
775 DIArray RetainedTypes = CUNode.getRetainedTypes();
776 for (unsigned i = 0, e = RetainedTypes.getNumElements(); i != e; ++i) {
777 DIType Ty(RetainedTypes.getElement(i));
778 // The retained types array by design contains pointers to
779 // MDNodes rather than DIRefs. Unique them here.
780 DIType UniqueTy(resolve(Ty.getRef()));
781 CU.getOrCreateTypeDIE(UniqueTy);
783 // Emit imported_modules last so that the relevant context is already
785 for (unsigned i = 0, e = ImportedEntities.getNumElements(); i != e; ++i)
786 constructImportedEntityDIE(CU, ImportedEntities.getElement(i));
789 // Tell MMI that we have debug info.
790 MMI->setDebugInfoAvailability(true);
792 // Prime section data.
793 SectionMap[Asm->getObjFileLowering().getTextSection()];
796 void DwarfDebug::finishVariableDefinitions() {
797 for (const auto &Var : ConcreteVariables) {
798 DIE *VariableDie = Var->getDIE();
800 // FIXME: Consider the time-space tradeoff of just storing the unit pointer
801 // in the ConcreteVariables list, rather than looking it up again here.
802 // DIE::getUnit isn't simple - it walks parent pointers, etc.
803 DwarfCompileUnit *Unit = lookupUnit(VariableDie->getUnit());
805 DbgVariable *AbsVar = getExistingAbstractVariable(Var->getVariable());
806 if (AbsVar && AbsVar->getDIE()) {
807 Unit->addDIEEntry(*VariableDie, dwarf::DW_AT_abstract_origin,
810 Unit->applyVariableAttributes(*Var, *VariableDie);
814 void DwarfDebug::finishSubprogramDefinitions() {
815 const Module *M = MMI->getModule();
817 NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
818 for (MDNode *N : CU_Nodes->operands()) {
819 DICompileUnit TheCU(N);
820 // Construct subprogram DIE and add variables DIEs.
821 DwarfCompileUnit *SPCU =
822 static_cast<DwarfCompileUnit *>(CUMap.lookup(TheCU));
823 DIArray Subprograms = TheCU.getSubprograms();
824 for (unsigned i = 0, e = Subprograms.getNumElements(); i != e; ++i) {
825 DISubprogram SP(Subprograms.getElement(i));
826 // Perhaps the subprogram is in another CU (such as due to comdat
827 // folding, etc), in which case ignore it here.
828 if (SPMap[SP] != SPCU)
830 DIE *D = SPCU->getDIE(SP);
831 if (DIE *AbsSPDIE = AbstractSPDies.lookup(SP)) {
833 // If this subprogram has an abstract definition, reference that
834 SPCU->addDIEEntry(*D, dwarf::DW_AT_abstract_origin, *AbsSPDIE);
837 // Lazily construct the subprogram if we didn't see either concrete or
838 // inlined versions during codegen.
839 D = SPCU->getOrCreateSubprogramDIE(SP);
840 // And attach the attributes
841 SPCU->applySubprogramAttributesToDefinition(SP, *D);
848 // Collect info for variables that were optimized out.
849 void DwarfDebug::collectDeadVariables() {
850 const Module *M = MMI->getModule();
852 if (NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu")) {
853 for (MDNode *N : CU_Nodes->operands()) {
854 DICompileUnit TheCU(N);
855 // Construct subprogram DIE and add variables DIEs.
856 DwarfCompileUnit *SPCU =
857 static_cast<DwarfCompileUnit *>(CUMap.lookup(TheCU));
858 assert(SPCU && "Unable to find Compile Unit!");
859 DIArray Subprograms = TheCU.getSubprograms();
860 for (unsigned i = 0, e = Subprograms.getNumElements(); i != e; ++i) {
861 DISubprogram SP(Subprograms.getElement(i));
862 if (ProcessedSPNodes.count(SP) != 0)
864 assert(SP.isSubprogram() &&
865 "CU's subprogram list contains a non-subprogram");
866 assert(SP.isDefinition() &&
867 "CU's subprogram list contains a subprogram declaration");
868 DIArray Variables = SP.getVariables();
869 if (Variables.getNumElements() == 0)
872 DIE *SPDIE = AbstractSPDies.lookup(SP);
874 SPDIE = SPCU->getDIE(SP);
876 for (unsigned vi = 0, ve = Variables.getNumElements(); vi != ve; ++vi) {
877 DIVariable DV(Variables.getElement(vi));
878 assert(DV.isVariable());
879 DbgVariable NewVar(DV, this);
880 auto VariableDie = SPCU->constructVariableDIE(NewVar);
881 SPCU->applyVariableAttributes(NewVar, *VariableDie);
882 SPDIE->addChild(std::move(VariableDie));
889 void DwarfDebug::finalizeModuleInfo() {
890 finishSubprogramDefinitions();
892 finishVariableDefinitions();
894 // Collect info for variables that were optimized out.
895 collectDeadVariables();
897 // Handle anything that needs to be done on a per-unit basis after
898 // all other generation.
899 for (const auto &TheU : getUnits()) {
900 // Emit DW_AT_containing_type attribute to connect types with their
901 // vtable holding type.
902 TheU->constructContainingTypeDIEs();
904 // Add CU specific attributes if we need to add any.
905 if (TheU->getUnitDie().getTag() == dwarf::DW_TAG_compile_unit) {
906 // If we're splitting the dwarf out now that we've got the entire
907 // CU then add the dwo id to it.
908 DwarfCompileUnit *SkCU =
909 static_cast<DwarfCompileUnit *>(TheU->getSkeleton());
910 if (useSplitDwarf()) {
911 // Emit a unique identifier for this CU.
912 uint64_t ID = DIEHash(Asm).computeCUSignature(TheU->getUnitDie());
913 TheU->addUInt(TheU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
914 dwarf::DW_FORM_data8, ID);
915 SkCU->addUInt(SkCU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
916 dwarf::DW_FORM_data8, ID);
918 // We don't keep track of which addresses are used in which CU so this
919 // is a bit pessimistic under LTO.
920 if (!AddrPool.isEmpty())
921 addSectionLabel(*Asm, *SkCU, SkCU->getUnitDie(),
922 dwarf::DW_AT_GNU_addr_base, DwarfAddrSectionSym,
923 DwarfAddrSectionSym);
924 if (!TheU->getRangeLists().empty())
925 addSectionLabel(*Asm, *SkCU, SkCU->getUnitDie(),
926 dwarf::DW_AT_GNU_ranges_base,
927 DwarfDebugRangeSectionSym, DwarfDebugRangeSectionSym);
930 // If we have code split among multiple sections or non-contiguous
931 // ranges of code then emit a DW_AT_ranges attribute on the unit that will
932 // remain in the .o file, otherwise add a DW_AT_low_pc.
933 // FIXME: We should use ranges allow reordering of code ala
934 // .subsections_via_symbols in mach-o. This would mean turning on
935 // ranges for all subprogram DIEs for mach-o.
936 DwarfCompileUnit &U =
937 SkCU ? *SkCU : static_cast<DwarfCompileUnit &>(*TheU);
938 unsigned NumRanges = TheU->getRanges().size();
941 addSectionLabel(*Asm, U, U.getUnitDie(), dwarf::DW_AT_ranges,
942 Asm->GetTempSymbol("cu_ranges", U.getUniqueID()),
943 DwarfDebugRangeSectionSym);
945 // A DW_AT_low_pc attribute may also be specified in combination with
946 // DW_AT_ranges to specify the default base address for use in
947 // location lists (see Section 2.6.2) and range lists (see Section
949 U.addUInt(U.getUnitDie(), dwarf::DW_AT_low_pc, dwarf::DW_FORM_addr,
952 RangeSpan &Range = TheU->getRanges().back();
953 U.addLocalLabelAddress(U.getUnitDie(), dwarf::DW_AT_low_pc,
955 U.addLabelDelta(U.getUnitDie(), dwarf::DW_AT_high_pc, Range.getEnd(),
962 // Compute DIE offsets and sizes.
963 InfoHolder.computeSizeAndOffsets();
965 SkeletonHolder.computeSizeAndOffsets();
968 void DwarfDebug::endSections() {
969 // Filter labels by section.
970 for (const SymbolCU &SCU : ArangeLabels) {
971 if (SCU.Sym->isInSection()) {
972 // Make a note of this symbol and it's section.
973 const MCSection *Section = &SCU.Sym->getSection();
974 if (!Section->getKind().isMetadata())
975 SectionMap[Section].push_back(SCU);
977 // Some symbols (e.g. common/bss on mach-o) can have no section but still
978 // appear in the output. This sucks as we rely on sections to build
979 // arange spans. We can do it without, but it's icky.
980 SectionMap[nullptr].push_back(SCU);
984 // Build a list of sections used.
985 std::vector<const MCSection *> Sections;
986 for (const auto &it : SectionMap) {
987 const MCSection *Section = it.first;
988 Sections.push_back(Section);
991 // Sort the sections into order.
992 // This is only done to ensure consistent output order across different runs.
993 std::sort(Sections.begin(), Sections.end(), SectionSort);
995 // Add terminating symbols for each section.
996 for (unsigned ID = 0, E = Sections.size(); ID != E; ID++) {
997 const MCSection *Section = Sections[ID];
998 MCSymbol *Sym = nullptr;
1001 // We can't call MCSection::getLabelEndName, as it's only safe to do so
1002 // if we know the section name up-front. For user-created sections, the
1003 // resulting label may not be valid to use as a label. (section names can
1004 // use a greater set of characters on some systems)
1005 Sym = Asm->GetTempSymbol("debug_end", ID);
1006 Asm->OutStreamer.SwitchSection(Section);
1007 Asm->OutStreamer.EmitLabel(Sym);
1010 // Insert a final terminator.
1011 SectionMap[Section].push_back(SymbolCU(nullptr, Sym));
1015 // Emit all Dwarf sections that should come after the content.
1016 void DwarfDebug::endModule() {
1017 assert(CurFn == nullptr);
1018 assert(CurMI == nullptr);
1023 // End any existing sections.
1024 // TODO: Does this need to happen?
1027 // Finalize the debug info for the module.
1028 finalizeModuleInfo();
1032 // Emit all the DIEs into a debug info section.
1035 // Corresponding abbreviations into a abbrev section.
1036 emitAbbreviations();
1038 // Emit info into a debug aranges section.
1039 if (GenerateARangeSection)
1042 // Emit info into a debug ranges section.
1045 if (useSplitDwarf()) {
1048 emitDebugAbbrevDWO();
1051 // Emit DWO addresses.
1052 AddrPool.emit(*Asm, Asm->getObjFileLowering().getDwarfAddrSection());
1054 // Emit info into a debug loc section.
1057 // Emit info into the dwarf accelerator table sections.
1058 if (useDwarfAccelTables()) {
1061 emitAccelNamespaces();
1065 // Emit the pubnames and pubtypes sections if requested.
1066 if (HasDwarfPubSections) {
1067 emitDebugPubNames(GenerateGnuPubSections);
1068 emitDebugPubTypes(GenerateGnuPubSections);
1073 AbstractVariables.clear();
1075 // Reset these for the next Module if we have one.
1079 // Find abstract variable, if any, associated with Var.
1080 DbgVariable *DwarfDebug::getExistingAbstractVariable(const DIVariable &DV,
1081 DIVariable &Cleansed) {
1082 LLVMContext &Ctx = DV->getContext();
1083 // More then one inlined variable corresponds to one abstract variable.
1084 // FIXME: This duplication of variables when inlining should probably be
1085 // removed. It's done to allow each DIVariable to describe its location
1086 // because the DebugLoc on the dbg.value/declare isn't accurate. We should
1087 // make it accurate then remove this duplication/cleansing stuff.
1088 Cleansed = cleanseInlinedVariable(DV, Ctx);
1089 auto I = AbstractVariables.find(Cleansed);
1090 if (I != AbstractVariables.end())
1091 return I->second.get();
1095 DbgVariable *DwarfDebug::getExistingAbstractVariable(const DIVariable &DV) {
1096 DIVariable Cleansed;
1097 return getExistingAbstractVariable(DV, Cleansed);
1100 void DwarfDebug::createAbstractVariable(const DIVariable &Var,
1101 LexicalScope *Scope) {
1102 auto AbsDbgVariable = make_unique<DbgVariable>(Var, this);
1103 addScopeVariable(Scope, AbsDbgVariable.get());
1104 AbstractVariables[Var] = std::move(AbsDbgVariable);
1107 void DwarfDebug::ensureAbstractVariableIsCreated(const DIVariable &DV,
1108 const MDNode *ScopeNode) {
1109 DIVariable Cleansed = DV;
1110 if (getExistingAbstractVariable(DV, Cleansed))
1113 createAbstractVariable(Cleansed, LScopes.getOrCreateAbstractScope(ScopeNode));
1117 DwarfDebug::ensureAbstractVariableIsCreatedIfScoped(const DIVariable &DV,
1118 const MDNode *ScopeNode) {
1119 DIVariable Cleansed = DV;
1120 if (getExistingAbstractVariable(DV, Cleansed))
1123 if (LexicalScope *Scope = LScopes.findAbstractScope(ScopeNode))
1124 createAbstractVariable(Cleansed, Scope);
1127 // If Var is a current function argument then add it to CurrentFnArguments list.
1128 bool DwarfDebug::addCurrentFnArgument(DbgVariable *Var, LexicalScope *Scope) {
1129 if (!LScopes.isCurrentFunctionScope(Scope))
1131 DIVariable DV = Var->getVariable();
1132 if (DV.getTag() != dwarf::DW_TAG_arg_variable)
1134 unsigned ArgNo = DV.getArgNumber();
1138 size_t Size = CurrentFnArguments.size();
1140 CurrentFnArguments.resize(CurFn->getFunction()->arg_size());
1141 // llvm::Function argument size is not good indicator of how many
1142 // arguments does the function have at source level.
1144 CurrentFnArguments.resize(ArgNo * 2);
1145 assert(!CurrentFnArguments[ArgNo - 1]);
1146 CurrentFnArguments[ArgNo - 1] = Var;
1150 // Collect variable information from side table maintained by MMI.
1151 void DwarfDebug::collectVariableInfoFromMMITable(
1152 SmallPtrSetImpl<const MDNode *> &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 DwarfDebug::buildLocationList(SmallVectorImpl<DebugLocEntry> &DebugLoc,
1233 const DbgValueHistoryMap::InstrRanges &Ranges) {
1234 SmallVector<DebugLocEntry::Value, 4> OpenRanges;
1236 for (auto I = Ranges.begin(), E = Ranges.end(); I != E; ++I) {
1237 const MachineInstr *Begin = I->first;
1238 const MachineInstr *End = I->second;
1239 assert(Begin->isDebugValue() && "Invalid History entry");
1241 // Check if a variable is inaccessible in this range.
1242 if (Begin->getNumOperands() > 1 &&
1243 Begin->getOperand(0).isReg() && !Begin->getOperand(0).getReg()) {
1248 // If this piece overlaps with any open ranges, truncate them.
1249 DIVariable DIVar = Begin->getDebugVariable();
1250 auto Last = std::remove_if(OpenRanges.begin(), OpenRanges.end(),
1251 [&](DebugLocEntry::Value R) {
1252 return piecesOverlap(DIVar, R.getVariable());
1254 OpenRanges.erase(Last, OpenRanges.end());
1256 const MCSymbol *StartLabel = getLabelBeforeInsn(Begin);
1257 assert(StartLabel && "Forgot label before DBG_VALUE starting a range!");
1259 const MCSymbol *EndLabel;
1261 EndLabel = getLabelAfterInsn(End);
1262 else if (std::next(I) == Ranges.end())
1263 EndLabel = FunctionEndSym;
1265 EndLabel = getLabelBeforeInsn(std::next(I)->first);
1266 assert(EndLabel && "Forgot label after instruction ending a range!");
1268 DEBUG(dbgs() << "DotDebugLoc: " << *Begin << "\n");
1270 auto Value = getDebugLocValue(Begin);
1271 DebugLocEntry Loc(StartLabel, EndLabel, Value);
1272 bool couldMerge = false;
1274 // If this is a piece, it may belong to the current DebugLocEntry.
1275 if (DIVar.isVariablePiece()) {
1276 // Add this value to the list of open ranges.
1277 OpenRanges.push_back(Value);
1279 // Attempt to add the piece to the last entry.
1280 if (!DebugLoc.empty())
1281 if (DebugLoc.back().MergeValues(Loc))
1286 // Need to add a new DebugLocEntry. Add all values from still
1287 // valid non-overlapping pieces.
1288 if (OpenRanges.size())
1289 Loc.addValues(OpenRanges);
1291 DebugLoc.push_back(std::move(Loc));
1294 // Attempt to coalesce the ranges of two otherwise identical
1296 auto CurEntry = DebugLoc.rbegin();
1297 auto PrevEntry = std::next(CurEntry);
1298 if (PrevEntry != DebugLoc.rend() && PrevEntry->MergeRanges(*CurEntry))
1299 DebugLoc.pop_back();
1301 DEBUG(dbgs() << "Values:\n";
1302 for (auto Value : CurEntry->getValues())
1303 Value.getVariable()->dump();
1304 dbgs() << "-----\n");
1309 // Find variables for each lexical scope.
1311 DwarfDebug::collectVariableInfo(SmallPtrSetImpl<const MDNode *> &Processed) {
1312 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1313 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1315 // Grab the variable info that was squirreled away in the MMI side-table.
1316 collectVariableInfoFromMMITable(Processed);
1318 for (const auto &I : DbgValues) {
1319 DIVariable DV(I.first);
1320 if (Processed.count(DV))
1323 // Instruction ranges, specifying where DV is accessible.
1324 const auto &Ranges = I.second;
1328 LexicalScope *Scope = nullptr;
1329 if (MDNode *IA = DV.getInlinedAt()) {
1330 DebugLoc DL = DebugLoc::getFromDILocation(IA);
1331 Scope = LScopes.findInlinedScope(DebugLoc::get(
1332 DL.getLine(), DL.getCol(), DV.getContext(), IA));
1334 Scope = LScopes.findLexicalScope(DV.getContext());
1335 // If variable scope is not found then skip this variable.
1339 Processed.insert(getEntireVariable(DV));
1340 const MachineInstr *MInsn = Ranges.front().first;
1341 assert(MInsn->isDebugValue() && "History must begin with debug value");
1342 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
1343 ConcreteVariables.push_back(make_unique<DbgVariable>(MInsn, this));
1344 DbgVariable *RegVar = ConcreteVariables.back().get();
1345 addScopeVariable(Scope, RegVar);
1347 // Check if the first DBG_VALUE is valid for the rest of the function.
1348 if (Ranges.size() == 1 && Ranges.front().second == nullptr)
1351 // Handle multiple DBG_VALUE instructions describing one variable.
1352 RegVar->setDotDebugLocOffset(DotDebugLocEntries.size());
1354 DotDebugLocEntries.resize(DotDebugLocEntries.size() + 1);
1355 DebugLocList &LocList = DotDebugLocEntries.back();
1358 Asm->GetTempSymbol("debug_loc", DotDebugLocEntries.size() - 1);
1360 // Build the location list for this variable.
1361 buildLocationList(LocList.List, Ranges);
1364 // Collect info for variables that were optimized out.
1365 DIArray Variables = DISubprogram(FnScope->getScopeNode()).getVariables();
1366 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1367 DIVariable DV(Variables.getElement(i));
1368 assert(DV.isVariable());
1369 if (!Processed.insert(DV))
1371 if (LexicalScope *Scope = LScopes.findLexicalScope(DV.getContext())) {
1372 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
1373 ConcreteVariables.push_back(make_unique<DbgVariable>(DV, this));
1374 addScopeVariable(Scope, ConcreteVariables.back().get());
1379 // Return Label preceding the instruction.
1380 MCSymbol *DwarfDebug::getLabelBeforeInsn(const MachineInstr *MI) {
1381 MCSymbol *Label = LabelsBeforeInsn.lookup(MI);
1382 assert(Label && "Didn't insert label before instruction");
1386 // Return Label immediately following the instruction.
1387 MCSymbol *DwarfDebug::getLabelAfterInsn(const MachineInstr *MI) {
1388 return LabelsAfterInsn.lookup(MI);
1391 // Process beginning of an instruction.
1392 void DwarfDebug::beginInstruction(const MachineInstr *MI) {
1393 assert(CurMI == nullptr);
1395 // Check if source location changes, but ignore DBG_VALUE locations.
1396 if (!MI->isDebugValue()) {
1397 DebugLoc DL = MI->getDebugLoc();
1398 if (DL != PrevInstLoc && (!DL.isUnknown() || UnknownLocations)) {
1401 if (DL == PrologEndLoc) {
1402 Flags |= DWARF2_FLAG_PROLOGUE_END;
1403 PrologEndLoc = DebugLoc();
1405 if (PrologEndLoc.isUnknown())
1406 Flags |= DWARF2_FLAG_IS_STMT;
1408 if (!DL.isUnknown()) {
1409 const MDNode *Scope = DL.getScope(Asm->MF->getFunction()->getContext());
1410 recordSourceLine(DL.getLine(), DL.getCol(), Scope, Flags);
1412 recordSourceLine(0, 0, nullptr, 0);
1416 // Insert labels where requested.
1417 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1418 LabelsBeforeInsn.find(MI);
1421 if (I == LabelsBeforeInsn.end())
1424 // Label already assigned.
1429 PrevLabel = MMI->getContext().CreateTempSymbol();
1430 Asm->OutStreamer.EmitLabel(PrevLabel);
1432 I->second = PrevLabel;
1435 // Process end of an instruction.
1436 void DwarfDebug::endInstruction() {
1437 assert(CurMI != nullptr);
1438 // Don't create a new label after DBG_VALUE instructions.
1439 // They don't generate code.
1440 if (!CurMI->isDebugValue())
1441 PrevLabel = nullptr;
1443 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1444 LabelsAfterInsn.find(CurMI);
1448 if (I == LabelsAfterInsn.end())
1451 // Label already assigned.
1455 // We need a label after this instruction.
1457 PrevLabel = MMI->getContext().CreateTempSymbol();
1458 Asm->OutStreamer.EmitLabel(PrevLabel);
1460 I->second = PrevLabel;
1463 // Each LexicalScope has first instruction and last instruction to mark
1464 // beginning and end of a scope respectively. Create an inverse map that list
1465 // scopes starts (and ends) with an instruction. One instruction may start (or
1466 // end) multiple scopes. Ignore scopes that are not reachable.
1467 void DwarfDebug::identifyScopeMarkers() {
1468 SmallVector<LexicalScope *, 4> WorkList;
1469 WorkList.push_back(LScopes.getCurrentFunctionScope());
1470 while (!WorkList.empty()) {
1471 LexicalScope *S = WorkList.pop_back_val();
1473 const SmallVectorImpl<LexicalScope *> &Children = S->getChildren();
1474 if (!Children.empty())
1475 WorkList.append(Children.begin(), Children.end());
1477 if (S->isAbstractScope())
1480 for (const InsnRange &R : S->getRanges()) {
1481 assert(R.first && "InsnRange does not have first instruction!");
1482 assert(R.second && "InsnRange does not have second instruction!");
1483 requestLabelBeforeInsn(R.first);
1484 requestLabelAfterInsn(R.second);
1489 static DebugLoc findPrologueEndLoc(const MachineFunction *MF) {
1490 // First known non-DBG_VALUE and non-frame setup location marks
1491 // the beginning of the function body.
1492 for (const auto &MBB : *MF)
1493 for (const auto &MI : MBB)
1494 if (!MI.isDebugValue() && !MI.getFlag(MachineInstr::FrameSetup) &&
1495 !MI.getDebugLoc().isUnknown())
1496 return MI.getDebugLoc();
1500 // Gather pre-function debug information. Assumes being called immediately
1501 // after the function entry point has been emitted.
1502 void DwarfDebug::beginFunction(const MachineFunction *MF) {
1505 // If there's no debug info for the function we're not going to do anything.
1506 if (!MMI->hasDebugInfo())
1509 auto DI = FunctionDIs.find(MF->getFunction());
1510 if (DI == FunctionDIs.end())
1513 // Grab the lexical scopes for the function, if we don't have any of those
1514 // then we're not going to be able to do anything.
1515 LScopes.initialize(*MF);
1516 if (LScopes.empty())
1519 assert(DbgValues.empty() && "DbgValues map wasn't cleaned!");
1521 // Make sure that each lexical scope will have a begin/end label.
1522 identifyScopeMarkers();
1524 // Set DwarfDwarfCompileUnitID in MCContext to the Compile Unit this function
1525 // belongs to so that we add to the correct per-cu line table in the
1527 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1528 // FnScope->getScopeNode() and DI->second should represent the same function,
1529 // though they may not be the same MDNode due to inline functions merged in
1530 // LTO where the debug info metadata still differs (either due to distinct
1531 // written differences - two versions of a linkonce_odr function
1532 // written/copied into two separate files, or some sub-optimal metadata that
1533 // isn't structurally identical (see: file path/name info from clang, which
1534 // includes the directory of the cpp file being built, even when the file name
1535 // is absolute (such as an <> lookup header)))
1536 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1537 assert(TheCU && "Unable to find compile unit!");
1538 if (Asm->OutStreamer.hasRawTextSupport())
1539 // Use a single line table if we are generating assembly.
1540 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1542 Asm->OutStreamer.getContext().setDwarfCompileUnitID(TheCU->getUniqueID());
1544 // Emit a label for the function so that we have a beginning address.
1545 FunctionBeginSym = Asm->GetTempSymbol("func_begin", Asm->getFunctionNumber());
1546 // Assumes in correct section after the entry point.
1547 Asm->OutStreamer.EmitLabel(FunctionBeginSym);
1549 // Calculate history for local variables.
1550 calculateDbgValueHistory(MF, Asm->TM.getSubtargetImpl()->getRegisterInfo(),
1553 // Request labels for the full history.
1554 for (const auto &I : DbgValues) {
1555 const auto &Ranges = I.second;
1559 // The first mention of a function argument gets the FunctionBeginSym
1560 // label, so arguments are visible when breaking at function entry.
1561 DIVariable DV(Ranges.front().first->getDebugVariable());
1562 if (DV.isVariable() && DV.getTag() == dwarf::DW_TAG_arg_variable &&
1563 getDISubprogram(DV.getContext()).describes(MF->getFunction())) {
1564 if (!DV.isVariablePiece())
1565 LabelsBeforeInsn[Ranges.front().first] = FunctionBeginSym;
1567 // Mark all non-overlapping initial pieces.
1568 for (auto I = Ranges.begin(); I != Ranges.end(); ++I) {
1569 DIVariable Piece = I->first->getDebugVariable();
1570 if (std::all_of(Ranges.begin(), I,
1571 [&](DbgValueHistoryMap::InstrRange Pred){
1572 return !piecesOverlap(Piece, Pred.first->getDebugVariable());
1574 LabelsBeforeInsn[I->first] = FunctionBeginSym;
1581 for (const auto &Range : Ranges) {
1582 requestLabelBeforeInsn(Range.first);
1584 requestLabelAfterInsn(Range.second);
1588 PrevInstLoc = DebugLoc();
1589 PrevLabel = FunctionBeginSym;
1591 // Record beginning of function.
1592 PrologEndLoc = findPrologueEndLoc(MF);
1593 if (!PrologEndLoc.isUnknown()) {
1594 DebugLoc FnStartDL =
1595 PrologEndLoc.getFnDebugLoc(MF->getFunction()->getContext());
1597 FnStartDL.getLine(), FnStartDL.getCol(),
1598 FnStartDL.getScope(MF->getFunction()->getContext()),
1599 // We'd like to list the prologue as "not statements" but GDB behaves
1600 // poorly if we do that. Revisit this with caution/GDB (7.5+) testing.
1601 DWARF2_FLAG_IS_STMT);
1605 void DwarfDebug::addScopeVariable(LexicalScope *LS, DbgVariable *Var) {
1606 if (addCurrentFnArgument(Var, LS))
1608 SmallVectorImpl<DbgVariable *> &Vars = ScopeVariables[LS];
1609 DIVariable DV = Var->getVariable();
1610 // Variables with positive arg numbers are parameters.
1611 if (unsigned ArgNum = DV.getArgNumber()) {
1612 // Keep all parameters in order at the start of the variable list to ensure
1613 // function types are correct (no out-of-order parameters)
1615 // This could be improved by only doing it for optimized builds (unoptimized
1616 // builds have the right order to begin with), searching from the back (this
1617 // would catch the unoptimized case quickly), or doing a binary search
1618 // rather than linear search.
1619 SmallVectorImpl<DbgVariable *>::iterator I = Vars.begin();
1620 while (I != Vars.end()) {
1621 unsigned CurNum = (*I)->getVariable().getArgNumber();
1622 // A local (non-parameter) variable has been found, insert immediately
1626 // A later indexed parameter has been found, insert immediately before it.
1627 if (CurNum > ArgNum)
1631 Vars.insert(I, Var);
1635 Vars.push_back(Var);
1638 // Gather and emit post-function debug information.
1639 void DwarfDebug::endFunction(const MachineFunction *MF) {
1640 // Every beginFunction(MF) call should be followed by an endFunction(MF) call,
1641 // though the beginFunction may not be called at all.
1642 // We should handle both cases.
1646 assert(CurFn == MF);
1647 assert(CurFn != nullptr);
1649 if (!MMI->hasDebugInfo() || LScopes.empty() ||
1650 !FunctionDIs.count(MF->getFunction())) {
1651 // If we don't have a lexical scope for this function then there will
1652 // be a hole in the range information. Keep note of this by setting the
1653 // previously used section to nullptr.
1654 PrevSection = nullptr;
1660 // Define end label for subprogram.
1661 FunctionEndSym = Asm->GetTempSymbol("func_end", Asm->getFunctionNumber());
1662 // Assumes in correct section after the entry point.
1663 Asm->OutStreamer.EmitLabel(FunctionEndSym);
1665 // Set DwarfDwarfCompileUnitID in MCContext to default value.
1666 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1668 SmallPtrSet<const MDNode *, 16> ProcessedVars;
1669 collectVariableInfo(ProcessedVars);
1671 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1672 DwarfCompileUnit &TheCU = *SPMap.lookup(FnScope->getScopeNode());
1674 // Construct abstract scopes.
1675 for (LexicalScope *AScope : LScopes.getAbstractScopesList()) {
1676 DISubprogram SP(AScope->getScopeNode());
1677 assert(SP.isSubprogram());
1678 // Collect info for variables that were optimized out.
1679 DIArray Variables = SP.getVariables();
1680 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1681 DIVariable DV(Variables.getElement(i));
1682 assert(DV && DV.isVariable());
1683 if (!ProcessedVars.insert(DV))
1685 ensureAbstractVariableIsCreated(DV, DV.getContext());
1687 constructAbstractSubprogramScopeDIE(TheCU, AScope);
1690 DIE &CurFnDIE = constructSubprogramScopeDIE(TheCU, FnScope);
1691 if (!CurFn->getTarget().Options.DisableFramePointerElim(*CurFn))
1692 TheCU.addFlag(CurFnDIE, dwarf::DW_AT_APPLE_omit_frame_ptr);
1694 // Add the range of this function to the list of ranges for the CU.
1695 RangeSpan Span(FunctionBeginSym, FunctionEndSym);
1696 TheCU.addRange(std::move(Span));
1697 PrevSection = Asm->getCurrentSection();
1701 // Ownership of DbgVariables is a bit subtle - ScopeVariables owns all the
1702 // DbgVariables except those that are also in AbstractVariables (since they
1703 // can be used cross-function)
1704 ScopeVariables.clear();
1705 CurrentFnArguments.clear();
1707 LabelsBeforeInsn.clear();
1708 LabelsAfterInsn.clear();
1709 PrevLabel = nullptr;
1713 // Register a source line with debug info. Returns the unique label that was
1714 // emitted and which provides correspondence to the source line list.
1715 void DwarfDebug::recordSourceLine(unsigned Line, unsigned Col, const MDNode *S,
1720 unsigned Discriminator = 0;
1721 if (DIScope Scope = DIScope(S)) {
1722 assert(Scope.isScope());
1723 Fn = Scope.getFilename();
1724 Dir = Scope.getDirectory();
1725 if (Scope.isLexicalBlockFile())
1726 Discriminator = DILexicalBlockFile(S).getDiscriminator();
1728 unsigned CUID = Asm->OutStreamer.getContext().getDwarfCompileUnitID();
1729 Src = static_cast<DwarfCompileUnit &>(*InfoHolder.getUnits()[CUID])
1730 .getOrCreateSourceID(Fn, Dir);
1732 Asm->OutStreamer.EmitDwarfLocDirective(Src, Line, Col, Flags, 0,
1736 //===----------------------------------------------------------------------===//
1738 //===----------------------------------------------------------------------===//
1740 // Emit initial Dwarf sections with a label at the start of each one.
1741 void DwarfDebug::emitSectionLabels() {
1742 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
1744 // Dwarf sections base addresses.
1745 DwarfInfoSectionSym =
1746 emitSectionSym(Asm, TLOF.getDwarfInfoSection(), "section_info");
1747 if (useSplitDwarf()) {
1748 DwarfInfoDWOSectionSym =
1749 emitSectionSym(Asm, TLOF.getDwarfInfoDWOSection(), "section_info_dwo");
1750 DwarfTypesDWOSectionSym =
1751 emitSectionSym(Asm, TLOF.getDwarfTypesDWOSection(), "section_types_dwo");
1753 DwarfAbbrevSectionSym =
1754 emitSectionSym(Asm, TLOF.getDwarfAbbrevSection(), "section_abbrev");
1755 if (useSplitDwarf())
1756 DwarfAbbrevDWOSectionSym = emitSectionSym(
1757 Asm, TLOF.getDwarfAbbrevDWOSection(), "section_abbrev_dwo");
1758 if (GenerateARangeSection)
1759 emitSectionSym(Asm, TLOF.getDwarfARangesSection());
1761 DwarfLineSectionSym =
1762 emitSectionSym(Asm, TLOF.getDwarfLineSection(), "section_line");
1763 if (GenerateGnuPubSections) {
1764 DwarfGnuPubNamesSectionSym =
1765 emitSectionSym(Asm, TLOF.getDwarfGnuPubNamesSection());
1766 DwarfGnuPubTypesSectionSym =
1767 emitSectionSym(Asm, TLOF.getDwarfGnuPubTypesSection());
1768 } else if (HasDwarfPubSections) {
1769 emitSectionSym(Asm, TLOF.getDwarfPubNamesSection());
1770 emitSectionSym(Asm, TLOF.getDwarfPubTypesSection());
1773 DwarfStrSectionSym =
1774 emitSectionSym(Asm, TLOF.getDwarfStrSection(), "info_string");
1775 if (useSplitDwarf()) {
1776 DwarfStrDWOSectionSym =
1777 emitSectionSym(Asm, TLOF.getDwarfStrDWOSection(), "skel_string");
1778 DwarfAddrSectionSym =
1779 emitSectionSym(Asm, TLOF.getDwarfAddrSection(), "addr_sec");
1780 DwarfDebugLocSectionSym =
1781 emitSectionSym(Asm, TLOF.getDwarfLocDWOSection(), "skel_loc");
1783 DwarfDebugLocSectionSym =
1784 emitSectionSym(Asm, TLOF.getDwarfLocSection(), "section_debug_loc");
1785 DwarfDebugRangeSectionSym =
1786 emitSectionSym(Asm, TLOF.getDwarfRangesSection(), "debug_range");
1789 // Recursively emits a debug information entry.
1790 void DwarfDebug::emitDIE(DIE &Die) {
1791 // Get the abbreviation for this DIE.
1792 const DIEAbbrev &Abbrev = Die.getAbbrev();
1794 // Emit the code (index) for the abbreviation.
1795 if (Asm->isVerbose())
1796 Asm->OutStreamer.AddComment("Abbrev [" + Twine(Abbrev.getNumber()) +
1797 "] 0x" + Twine::utohexstr(Die.getOffset()) +
1798 ":0x" + Twine::utohexstr(Die.getSize()) + " " +
1799 dwarf::TagString(Abbrev.getTag()));
1800 Asm->EmitULEB128(Abbrev.getNumber());
1802 const SmallVectorImpl<DIEValue *> &Values = Die.getValues();
1803 const SmallVectorImpl<DIEAbbrevData> &AbbrevData = Abbrev.getData();
1805 // Emit the DIE attribute values.
1806 for (unsigned i = 0, N = Values.size(); i < N; ++i) {
1807 dwarf::Attribute Attr = AbbrevData[i].getAttribute();
1808 dwarf::Form Form = AbbrevData[i].getForm();
1809 assert(Form && "Too many attributes for DIE (check abbreviation)");
1811 if (Asm->isVerbose()) {
1812 Asm->OutStreamer.AddComment(dwarf::AttributeString(Attr));
1813 if (Attr == dwarf::DW_AT_accessibility)
1814 Asm->OutStreamer.AddComment(dwarf::AccessibilityString(
1815 cast<DIEInteger>(Values[i])->getValue()));
1818 // Emit an attribute using the defined form.
1819 Values[i]->EmitValue(Asm, Form);
1822 // Emit the DIE children if any.
1823 if (Abbrev.hasChildren()) {
1824 for (auto &Child : Die.getChildren())
1827 Asm->OutStreamer.AddComment("End Of Children Mark");
1832 // Emit the debug info section.
1833 void DwarfDebug::emitDebugInfo() {
1834 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1836 Holder.emitUnits(this, DwarfAbbrevSectionSym);
1839 // Emit the abbreviation section.
1840 void DwarfDebug::emitAbbreviations() {
1841 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1843 Holder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevSection());
1846 // Emit the last address of the section and the end of the line matrix.
1847 void DwarfDebug::emitEndOfLineMatrix(unsigned SectionEnd) {
1848 // Define last address of section.
1849 Asm->OutStreamer.AddComment("Extended Op");
1852 Asm->OutStreamer.AddComment("Op size");
1853 Asm->EmitInt8(Asm->getDataLayout().getPointerSize() + 1);
1854 Asm->OutStreamer.AddComment("DW_LNE_set_address");
1855 Asm->EmitInt8(dwarf::DW_LNE_set_address);
1857 Asm->OutStreamer.AddComment("Section end label");
1859 Asm->OutStreamer.EmitSymbolValue(
1860 Asm->GetTempSymbol("section_end", SectionEnd),
1861 Asm->getDataLayout().getPointerSize());
1863 // Mark end of matrix.
1864 Asm->OutStreamer.AddComment("DW_LNE_end_sequence");
1870 // Emit visible names into a hashed accelerator table section.
1871 void DwarfDebug::emitAccelNames() {
1872 AccelNames.FinalizeTable(Asm, "Names");
1873 Asm->OutStreamer.SwitchSection(
1874 Asm->getObjFileLowering().getDwarfAccelNamesSection());
1875 MCSymbol *SectionBegin = Asm->GetTempSymbol("names_begin");
1876 Asm->OutStreamer.EmitLabel(SectionBegin);
1878 // Emit the full data.
1879 AccelNames.Emit(Asm, SectionBegin, &InfoHolder);
1882 // Emit objective C classes and categories into a hashed accelerator table
1884 void DwarfDebug::emitAccelObjC() {
1885 AccelObjC.FinalizeTable(Asm, "ObjC");
1886 Asm->OutStreamer.SwitchSection(
1887 Asm->getObjFileLowering().getDwarfAccelObjCSection());
1888 MCSymbol *SectionBegin = Asm->GetTempSymbol("objc_begin");
1889 Asm->OutStreamer.EmitLabel(SectionBegin);
1891 // Emit the full data.
1892 AccelObjC.Emit(Asm, SectionBegin, &InfoHolder);
1895 // Emit namespace dies into a hashed accelerator table.
1896 void DwarfDebug::emitAccelNamespaces() {
1897 AccelNamespace.FinalizeTable(Asm, "namespac");
1898 Asm->OutStreamer.SwitchSection(
1899 Asm->getObjFileLowering().getDwarfAccelNamespaceSection());
1900 MCSymbol *SectionBegin = Asm->GetTempSymbol("namespac_begin");
1901 Asm->OutStreamer.EmitLabel(SectionBegin);
1903 // Emit the full data.
1904 AccelNamespace.Emit(Asm, SectionBegin, &InfoHolder);
1907 // Emit type dies into a hashed accelerator table.
1908 void DwarfDebug::emitAccelTypes() {
1910 AccelTypes.FinalizeTable(Asm, "types");
1911 Asm->OutStreamer.SwitchSection(
1912 Asm->getObjFileLowering().getDwarfAccelTypesSection());
1913 MCSymbol *SectionBegin = Asm->GetTempSymbol("types_begin");
1914 Asm->OutStreamer.EmitLabel(SectionBegin);
1916 // Emit the full data.
1917 AccelTypes.Emit(Asm, SectionBegin, &InfoHolder);
1920 // Public name handling.
1921 // The format for the various pubnames:
1923 // dwarf pubnames - offset/name pairs where the offset is the offset into the CU
1924 // for the DIE that is named.
1926 // gnu pubnames - offset/index value/name tuples where the offset is the offset
1927 // into the CU and the index value is computed according to the type of value
1928 // for the DIE that is named.
1930 // For type units the offset is the offset of the skeleton DIE. For split dwarf
1931 // it's the offset within the debug_info/debug_types dwo section, however, the
1932 // reference in the pubname header doesn't change.
1934 /// computeIndexValue - Compute the gdb index value for the DIE and CU.
1935 static dwarf::PubIndexEntryDescriptor computeIndexValue(DwarfUnit *CU,
1937 dwarf::GDBIndexEntryLinkage Linkage = dwarf::GIEL_STATIC;
1939 // We could have a specification DIE that has our most of our knowledge,
1940 // look for that now.
1941 DIEValue *SpecVal = Die->findAttribute(dwarf::DW_AT_specification);
1943 DIE &SpecDIE = cast<DIEEntry>(SpecVal)->getEntry();
1944 if (SpecDIE.findAttribute(dwarf::DW_AT_external))
1945 Linkage = dwarf::GIEL_EXTERNAL;
1946 } else if (Die->findAttribute(dwarf::DW_AT_external))
1947 Linkage = dwarf::GIEL_EXTERNAL;
1949 switch (Die->getTag()) {
1950 case dwarf::DW_TAG_class_type:
1951 case dwarf::DW_TAG_structure_type:
1952 case dwarf::DW_TAG_union_type:
1953 case dwarf::DW_TAG_enumeration_type:
1954 return dwarf::PubIndexEntryDescriptor(
1955 dwarf::GIEK_TYPE, CU->getLanguage() != dwarf::DW_LANG_C_plus_plus
1956 ? dwarf::GIEL_STATIC
1957 : dwarf::GIEL_EXTERNAL);
1958 case dwarf::DW_TAG_typedef:
1959 case dwarf::DW_TAG_base_type:
1960 case dwarf::DW_TAG_subrange_type:
1961 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_TYPE, dwarf::GIEL_STATIC);
1962 case dwarf::DW_TAG_namespace:
1963 return dwarf::GIEK_TYPE;
1964 case dwarf::DW_TAG_subprogram:
1965 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_FUNCTION, Linkage);
1966 case dwarf::DW_TAG_constant:
1967 case dwarf::DW_TAG_variable:
1968 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE, Linkage);
1969 case dwarf::DW_TAG_enumerator:
1970 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE,
1971 dwarf::GIEL_STATIC);
1973 return dwarf::GIEK_NONE;
1977 /// emitDebugPubNames - Emit visible names into a debug pubnames section.
1979 void DwarfDebug::emitDebugPubNames(bool GnuStyle) {
1980 const MCSection *PSec =
1981 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubNamesSection()
1982 : Asm->getObjFileLowering().getDwarfPubNamesSection();
1984 emitDebugPubSection(GnuStyle, PSec, "Names", &DwarfUnit::getGlobalNames);
1987 void DwarfDebug::emitDebugPubSection(
1988 bool GnuStyle, const MCSection *PSec, StringRef Name,
1989 const StringMap<const DIE *> &(DwarfUnit::*Accessor)() const) {
1990 for (const auto &NU : CUMap) {
1991 DwarfCompileUnit *TheU = NU.second;
1993 const auto &Globals = (TheU->*Accessor)();
1995 if (Globals.empty())
1998 if (auto Skeleton = static_cast<DwarfCompileUnit *>(TheU->getSkeleton()))
2000 unsigned ID = TheU->getUniqueID();
2002 // Start the dwarf pubnames section.
2003 Asm->OutStreamer.SwitchSection(PSec);
2006 Asm->OutStreamer.AddComment("Length of Public " + Name + " Info");
2007 MCSymbol *BeginLabel = Asm->GetTempSymbol("pub" + Name + "_begin", ID);
2008 MCSymbol *EndLabel = Asm->GetTempSymbol("pub" + Name + "_end", ID);
2009 Asm->EmitLabelDifference(EndLabel, BeginLabel, 4);
2011 Asm->OutStreamer.EmitLabel(BeginLabel);
2013 Asm->OutStreamer.AddComment("DWARF Version");
2014 Asm->EmitInt16(dwarf::DW_PUBNAMES_VERSION);
2016 Asm->OutStreamer.AddComment("Offset of Compilation Unit Info");
2017 Asm->EmitSectionOffset(TheU->getLabelBegin(), TheU->getSectionSym());
2019 Asm->OutStreamer.AddComment("Compilation Unit Length");
2020 Asm->EmitLabelDifference(TheU->getLabelEnd(), TheU->getLabelBegin(), 4);
2022 // Emit the pubnames for this compilation unit.
2023 for (const auto &GI : Globals) {
2024 const char *Name = GI.getKeyData();
2025 const DIE *Entity = GI.second;
2027 Asm->OutStreamer.AddComment("DIE offset");
2028 Asm->EmitInt32(Entity->getOffset());
2031 dwarf::PubIndexEntryDescriptor Desc = computeIndexValue(TheU, Entity);
2032 Asm->OutStreamer.AddComment(
2033 Twine("Kind: ") + dwarf::GDBIndexEntryKindString(Desc.Kind) + ", " +
2034 dwarf::GDBIndexEntryLinkageString(Desc.Linkage));
2035 Asm->EmitInt8(Desc.toBits());
2038 Asm->OutStreamer.AddComment("External Name");
2039 Asm->OutStreamer.EmitBytes(StringRef(Name, GI.getKeyLength() + 1));
2042 Asm->OutStreamer.AddComment("End Mark");
2044 Asm->OutStreamer.EmitLabel(EndLabel);
2048 void DwarfDebug::emitDebugPubTypes(bool GnuStyle) {
2049 const MCSection *PSec =
2050 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubTypesSection()
2051 : Asm->getObjFileLowering().getDwarfPubTypesSection();
2053 emitDebugPubSection(GnuStyle, PSec, "Types", &DwarfUnit::getGlobalTypes);
2056 // Emit visible names into a debug str section.
2057 void DwarfDebug::emitDebugStr() {
2058 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
2059 Holder.emitStrings(Asm->getObjFileLowering().getDwarfStrSection());
2062 /// Emits an optimal (=sorted) sequence of DW_OP_pieces.
2063 void DwarfDebug::emitLocPieces(ByteStreamer &Streamer,
2064 const DITypeIdentifierMap &Map,
2065 ArrayRef<DebugLocEntry::Value> Values) {
2066 assert(std::all_of(Values.begin(), Values.end(), [](DebugLocEntry::Value P) {
2067 return P.isVariablePiece();
2068 }) && "all values are expected to be pieces");
2069 assert(std::is_sorted(Values.begin(), Values.end()) &&
2070 "pieces are expected to be sorted");
2072 unsigned Offset = 0;
2073 for (auto Piece : Values) {
2074 DIVariable Var = Piece.getVariable();
2075 unsigned PieceOffset = Var.getPieceOffset();
2076 unsigned PieceSize = Var.getPieceSize();
2077 assert(Offset <= PieceOffset && "overlapping or duplicate pieces");
2078 if (Offset < PieceOffset) {
2079 // The DWARF spec seriously mandates pieces with no locations for gaps.
2080 Asm->EmitDwarfOpPiece(Streamer, (PieceOffset-Offset)*8);
2081 Offset += PieceOffset-Offset;
2084 Offset += PieceSize;
2086 const unsigned SizeOfByte = 8;
2087 assert(!Var.isIndirect() && "indirect address for piece");
2089 unsigned VarSize = Var.getSizeInBits(Map);
2090 assert(PieceSize+PieceOffset <= VarSize/SizeOfByte
2091 && "piece is larger than or outside of variable");
2092 assert(PieceSize*SizeOfByte != VarSize
2093 && "piece covers entire variable");
2095 if (Piece.isLocation() && Piece.getLoc().isReg())
2096 Asm->EmitDwarfRegOpPiece(Streamer,
2098 PieceSize*SizeOfByte);
2100 emitDebugLocValue(Streamer, Piece);
2101 Asm->EmitDwarfOpPiece(Streamer, PieceSize*SizeOfByte);
2107 void DwarfDebug::emitDebugLocEntry(ByteStreamer &Streamer,
2108 const DebugLocEntry &Entry) {
2109 const DebugLocEntry::Value Value = Entry.getValues()[0];
2110 if (Value.isVariablePiece())
2111 // Emit all pieces that belong to the same variable and range.
2112 return emitLocPieces(Streamer, TypeIdentifierMap, Entry.getValues());
2114 assert(Entry.getValues().size() == 1 && "only pieces may have >1 value");
2115 emitDebugLocValue(Streamer, Value);
2118 void DwarfDebug::emitDebugLocValue(ByteStreamer &Streamer,
2119 const DebugLocEntry::Value &Value) {
2120 DIVariable DV = Value.getVariable();
2122 if (Value.isInt()) {
2123 DIBasicType BTy(resolve(DV.getType()));
2124 if (BTy.Verify() && (BTy.getEncoding() == dwarf::DW_ATE_signed ||
2125 BTy.getEncoding() == dwarf::DW_ATE_signed_char)) {
2126 Streamer.EmitInt8(dwarf::DW_OP_consts, "DW_OP_consts");
2127 Streamer.EmitSLEB128(Value.getInt());
2129 Streamer.EmitInt8(dwarf::DW_OP_constu, "DW_OP_constu");
2130 Streamer.EmitULEB128(Value.getInt());
2132 } else if (Value.isLocation()) {
2133 MachineLocation Loc = Value.getLoc();
2134 if (!DV.hasComplexAddress())
2136 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2138 // Complex address entry.
2139 unsigned N = DV.getNumAddrElements();
2141 if (N >= 2 && DV.getAddrElement(0) == DIBuilder::OpPlus) {
2142 if (Loc.getOffset()) {
2144 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2145 Streamer.EmitInt8(dwarf::DW_OP_deref, "DW_OP_deref");
2146 Streamer.EmitInt8(dwarf::DW_OP_plus_uconst, "DW_OP_plus_uconst");
2147 Streamer.EmitSLEB128(DV.getAddrElement(1));
2149 // If first address element is OpPlus then emit
2150 // DW_OP_breg + Offset instead of DW_OP_reg + Offset.
2151 MachineLocation TLoc(Loc.getReg(), DV.getAddrElement(1));
2152 Asm->EmitDwarfRegOp(Streamer, TLoc, DV.isIndirect());
2156 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2159 // Emit remaining complex address elements.
2160 for (; i < N; ++i) {
2161 uint64_t Element = DV.getAddrElement(i);
2162 if (Element == DIBuilder::OpPlus) {
2163 Streamer.EmitInt8(dwarf::DW_OP_plus_uconst, "DW_OP_plus_uconst");
2164 Streamer.EmitULEB128(DV.getAddrElement(++i));
2165 } else if (Element == DIBuilder::OpDeref) {
2167 Streamer.EmitInt8(dwarf::DW_OP_deref, "DW_OP_deref");
2168 } else if (Element == DIBuilder::OpPiece) {
2170 // handled in emitDebugLocEntry.
2172 llvm_unreachable("unknown Opcode found in complex address");
2176 // else ... ignore constant fp. There is not any good way to
2177 // to represent them here in dwarf.
2181 void DwarfDebug::emitDebugLocEntryLocation(const DebugLocEntry &Entry) {
2182 Asm->OutStreamer.AddComment("Loc expr size");
2183 MCSymbol *begin = Asm->OutStreamer.getContext().CreateTempSymbol();
2184 MCSymbol *end = Asm->OutStreamer.getContext().CreateTempSymbol();
2185 Asm->EmitLabelDifference(end, begin, 2);
2186 Asm->OutStreamer.EmitLabel(begin);
2188 APByteStreamer Streamer(*Asm);
2189 emitDebugLocEntry(Streamer, Entry);
2191 Asm->OutStreamer.EmitLabel(end);
2194 // Emit locations into the debug loc section.
2195 void DwarfDebug::emitDebugLoc() {
2196 // Start the dwarf loc section.
2197 Asm->OutStreamer.SwitchSection(
2198 Asm->getObjFileLowering().getDwarfLocSection());
2199 unsigned char Size = Asm->getDataLayout().getPointerSize();
2200 for (const auto &DebugLoc : DotDebugLocEntries) {
2201 Asm->OutStreamer.EmitLabel(DebugLoc.Label);
2202 const DwarfCompileUnit *CU = DebugLoc.CU;
2203 assert(!CU->getRanges().empty());
2204 for (const auto &Entry : DebugLoc.List) {
2205 // Set up the range. This range is relative to the entry point of the
2206 // compile unit. This is a hard coded 0 for low_pc when we're emitting
2207 // ranges, or the DW_AT_low_pc on the compile unit otherwise.
2208 if (CU->getRanges().size() == 1) {
2209 // Grab the begin symbol from the first range as our base.
2210 const MCSymbol *Base = CU->getRanges()[0].getStart();
2211 Asm->EmitLabelDifference(Entry.getBeginSym(), Base, Size);
2212 Asm->EmitLabelDifference(Entry.getEndSym(), Base, Size);
2214 Asm->OutStreamer.EmitSymbolValue(Entry.getBeginSym(), Size);
2215 Asm->OutStreamer.EmitSymbolValue(Entry.getEndSym(), Size);
2218 emitDebugLocEntryLocation(Entry);
2220 Asm->OutStreamer.EmitIntValue(0, Size);
2221 Asm->OutStreamer.EmitIntValue(0, Size);
2225 void DwarfDebug::emitDebugLocDWO() {
2226 Asm->OutStreamer.SwitchSection(
2227 Asm->getObjFileLowering().getDwarfLocDWOSection());
2228 for (const auto &DebugLoc : DotDebugLocEntries) {
2229 Asm->OutStreamer.EmitLabel(DebugLoc.Label);
2230 for (const auto &Entry : DebugLoc.List) {
2231 // Just always use start_length for now - at least that's one address
2232 // rather than two. We could get fancier and try to, say, reuse an
2233 // address we know we've emitted elsewhere (the start of the function?
2234 // The start of the CU or CU subrange that encloses this range?)
2235 Asm->EmitInt8(dwarf::DW_LLE_start_length_entry);
2236 unsigned idx = AddrPool.getIndex(Entry.getBeginSym());
2237 Asm->EmitULEB128(idx);
2238 Asm->EmitLabelDifference(Entry.getEndSym(), Entry.getBeginSym(), 4);
2240 emitDebugLocEntryLocation(Entry);
2242 Asm->EmitInt8(dwarf::DW_LLE_end_of_list_entry);
2247 const MCSymbol *Start, *End;
2250 // Emit a debug aranges section, containing a CU lookup for any
2251 // address we can tie back to a CU.
2252 void DwarfDebug::emitDebugARanges() {
2253 // Start the dwarf aranges section.
2254 Asm->OutStreamer.SwitchSection(
2255 Asm->getObjFileLowering().getDwarfARangesSection());
2257 typedef DenseMap<DwarfCompileUnit *, std::vector<ArangeSpan>> SpansType;
2261 // Build a list of sections used.
2262 std::vector<const MCSection *> Sections;
2263 for (const auto &it : SectionMap) {
2264 const MCSection *Section = it.first;
2265 Sections.push_back(Section);
2268 // Sort the sections into order.
2269 // This is only done to ensure consistent output order across different runs.
2270 std::sort(Sections.begin(), Sections.end(), SectionSort);
2272 // Build a set of address spans, sorted by CU.
2273 for (const MCSection *Section : Sections) {
2274 SmallVector<SymbolCU, 8> &List = SectionMap[Section];
2275 if (List.size() < 2)
2278 // Sort the symbols by offset within the section.
2279 std::sort(List.begin(), List.end(),
2280 [&](const SymbolCU &A, const SymbolCU &B) {
2281 unsigned IA = A.Sym ? Asm->OutStreamer.GetSymbolOrder(A.Sym) : 0;
2282 unsigned IB = B.Sym ? Asm->OutStreamer.GetSymbolOrder(B.Sym) : 0;
2284 // Symbols with no order assigned should be placed at the end.
2285 // (e.g. section end labels)
2293 // If we have no section (e.g. common), just write out
2294 // individual spans for each symbol.
2296 for (const SymbolCU &Cur : List) {
2298 Span.Start = Cur.Sym;
2301 Spans[Cur.CU].push_back(Span);
2304 // Build spans between each label.
2305 const MCSymbol *StartSym = List[0].Sym;
2306 for (size_t n = 1, e = List.size(); n < e; n++) {
2307 const SymbolCU &Prev = List[n - 1];
2308 const SymbolCU &Cur = List[n];
2310 // Try and build the longest span we can within the same CU.
2311 if (Cur.CU != Prev.CU) {
2313 Span.Start = StartSym;
2315 Spans[Prev.CU].push_back(Span);
2322 unsigned PtrSize = Asm->getDataLayout().getPointerSize();
2324 // Build a list of CUs used.
2325 std::vector<DwarfCompileUnit *> CUs;
2326 for (const auto &it : Spans) {
2327 DwarfCompileUnit *CU = it.first;
2331 // Sort the CU list (again, to ensure consistent output order).
2332 std::sort(CUs.begin(), CUs.end(), [](const DwarfUnit *A, const DwarfUnit *B) {
2333 return A->getUniqueID() < B->getUniqueID();
2336 // Emit an arange table for each CU we used.
2337 for (DwarfCompileUnit *CU : CUs) {
2338 std::vector<ArangeSpan> &List = Spans[CU];
2340 // Emit size of content not including length itself.
2341 unsigned ContentSize =
2342 sizeof(int16_t) + // DWARF ARange version number
2343 sizeof(int32_t) + // Offset of CU in the .debug_info section
2344 sizeof(int8_t) + // Pointer Size (in bytes)
2345 sizeof(int8_t); // Segment Size (in bytes)
2347 unsigned TupleSize = PtrSize * 2;
2349 // 7.20 in the Dwarf specs requires the table to be aligned to a tuple.
2351 OffsetToAlignment(sizeof(int32_t) + ContentSize, TupleSize);
2353 ContentSize += Padding;
2354 ContentSize += (List.size() + 1) * TupleSize;
2356 // For each compile unit, write the list of spans it covers.
2357 Asm->OutStreamer.AddComment("Length of ARange Set");
2358 Asm->EmitInt32(ContentSize);
2359 Asm->OutStreamer.AddComment("DWARF Arange version number");
2360 Asm->EmitInt16(dwarf::DW_ARANGES_VERSION);
2361 Asm->OutStreamer.AddComment("Offset Into Debug Info Section");
2362 Asm->EmitSectionOffset(CU->getLocalLabelBegin(), CU->getLocalSectionSym());
2363 Asm->OutStreamer.AddComment("Address Size (in bytes)");
2364 Asm->EmitInt8(PtrSize);
2365 Asm->OutStreamer.AddComment("Segment Size (in bytes)");
2368 Asm->OutStreamer.EmitFill(Padding, 0xff);
2370 for (const ArangeSpan &Span : List) {
2371 Asm->EmitLabelReference(Span.Start, PtrSize);
2373 // Calculate the size as being from the span start to it's end.
2375 Asm->EmitLabelDifference(Span.End, Span.Start, PtrSize);
2377 // For symbols without an end marker (e.g. common), we
2378 // write a single arange entry containing just that one symbol.
2379 uint64_t Size = SymSize[Span.Start];
2383 Asm->OutStreamer.EmitIntValue(Size, PtrSize);
2387 Asm->OutStreamer.AddComment("ARange terminator");
2388 Asm->OutStreamer.EmitIntValue(0, PtrSize);
2389 Asm->OutStreamer.EmitIntValue(0, PtrSize);
2393 // Emit visible names into a debug ranges section.
2394 void DwarfDebug::emitDebugRanges() {
2395 // Start the dwarf ranges section.
2396 Asm->OutStreamer.SwitchSection(
2397 Asm->getObjFileLowering().getDwarfRangesSection());
2399 // Size for our labels.
2400 unsigned char Size = Asm->getDataLayout().getPointerSize();
2402 // Grab the specific ranges for the compile units in the module.
2403 for (const auto &I : CUMap) {
2404 DwarfCompileUnit *TheCU = I.second;
2406 // Iterate over the misc ranges for the compile units in the module.
2407 for (const RangeSpanList &List : TheCU->getRangeLists()) {
2408 // Emit our symbol so we can find the beginning of the range.
2409 Asm->OutStreamer.EmitLabel(List.getSym());
2411 for (const RangeSpan &Range : List.getRanges()) {
2412 const MCSymbol *Begin = Range.getStart();
2413 const MCSymbol *End = Range.getEnd();
2414 assert(Begin && "Range without a begin symbol?");
2415 assert(End && "Range without an end symbol?");
2416 if (TheCU->getRanges().size() == 1) {
2417 // Grab the begin symbol from the first range as our base.
2418 const MCSymbol *Base = TheCU->getRanges()[0].getStart();
2419 Asm->EmitLabelDifference(Begin, Base, Size);
2420 Asm->EmitLabelDifference(End, Base, Size);
2422 Asm->OutStreamer.EmitSymbolValue(Begin, Size);
2423 Asm->OutStreamer.EmitSymbolValue(End, Size);
2427 // And terminate the list with two 0 values.
2428 Asm->OutStreamer.EmitIntValue(0, Size);
2429 Asm->OutStreamer.EmitIntValue(0, Size);
2432 // Now emit a range for the CU itself.
2433 if (TheCU->getRanges().size() > 1) {
2434 Asm->OutStreamer.EmitLabel(
2435 Asm->GetTempSymbol("cu_ranges", TheCU->getUniqueID()));
2436 for (const RangeSpan &Range : TheCU->getRanges()) {
2437 const MCSymbol *Begin = Range.getStart();
2438 const MCSymbol *End = Range.getEnd();
2439 assert(Begin && "Range without a begin symbol?");
2440 assert(End && "Range without an end symbol?");
2441 Asm->OutStreamer.EmitSymbolValue(Begin, Size);
2442 Asm->OutStreamer.EmitSymbolValue(End, Size);
2444 // And terminate the list with two 0 values.
2445 Asm->OutStreamer.EmitIntValue(0, Size);
2446 Asm->OutStreamer.EmitIntValue(0, Size);
2451 // DWARF5 Experimental Separate Dwarf emitters.
2453 void DwarfDebug::initSkeletonUnit(const DwarfUnit &U, DIE &Die,
2454 std::unique_ptr<DwarfUnit> NewU) {
2455 NewU->addLocalString(Die, dwarf::DW_AT_GNU_dwo_name,
2456 U.getCUNode().getSplitDebugFilename());
2458 if (!CompilationDir.empty())
2459 NewU->addLocalString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
2461 addGnuPubAttributes(*NewU, Die);
2463 SkeletonHolder.addUnit(std::move(NewU));
2466 // This DIE has the following attributes: DW_AT_comp_dir, DW_AT_stmt_list,
2467 // DW_AT_low_pc, DW_AT_high_pc, DW_AT_ranges, DW_AT_dwo_name, DW_AT_dwo_id,
2468 // DW_AT_addr_base, DW_AT_ranges_base.
2469 DwarfCompileUnit &DwarfDebug::constructSkeletonCU(const DwarfCompileUnit &CU) {
2471 auto OwnedUnit = make_unique<DwarfCompileUnit>(
2472 CU.getUniqueID(), CU.getCUNode(), Asm, this, &SkeletonHolder);
2473 DwarfCompileUnit &NewCU = *OwnedUnit;
2474 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoSection(),
2475 DwarfInfoSectionSym);
2477 NewCU.initStmtList(DwarfLineSectionSym);
2479 initSkeletonUnit(CU, NewCU.getUnitDie(), std::move(OwnedUnit));
2484 // Emit the .debug_info.dwo section for separated dwarf. This contains the
2485 // compile units that would normally be in debug_info.
2486 void DwarfDebug::emitDebugInfoDWO() {
2487 assert(useSplitDwarf() && "No split dwarf debug info?");
2488 // Don't pass an abbrev symbol, using a constant zero instead so as not to
2489 // emit relocations into the dwo file.
2490 InfoHolder.emitUnits(this, /* AbbrevSymbol */ nullptr);
2493 // Emit the .debug_abbrev.dwo section for separated dwarf. This contains the
2494 // abbreviations for the .debug_info.dwo section.
2495 void DwarfDebug::emitDebugAbbrevDWO() {
2496 assert(useSplitDwarf() && "No split dwarf?");
2497 InfoHolder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevDWOSection());
2500 void DwarfDebug::emitDebugLineDWO() {
2501 assert(useSplitDwarf() && "No split dwarf?");
2502 Asm->OutStreamer.SwitchSection(
2503 Asm->getObjFileLowering().getDwarfLineDWOSection());
2504 SplitTypeUnitFileTable.Emit(Asm->OutStreamer);
2507 // Emit the .debug_str.dwo section for separated dwarf. This contains the
2508 // string section and is identical in format to traditional .debug_str
2510 void DwarfDebug::emitDebugStrDWO() {
2511 assert(useSplitDwarf() && "No split dwarf?");
2512 const MCSection *OffSec =
2513 Asm->getObjFileLowering().getDwarfStrOffDWOSection();
2514 const MCSymbol *StrSym = DwarfStrSectionSym;
2515 InfoHolder.emitStrings(Asm->getObjFileLowering().getDwarfStrDWOSection(),
2519 MCDwarfDwoLineTable *DwarfDebug::getDwoLineTable(const DwarfCompileUnit &CU) {
2520 if (!useSplitDwarf())
2523 SplitTypeUnitFileTable.setCompilationDir(CU.getCUNode().getDirectory());
2524 return &SplitTypeUnitFileTable;
2527 static uint64_t makeTypeSignature(StringRef Identifier) {
2529 Hash.update(Identifier);
2530 // ... take the least significant 8 bytes and return those. Our MD5
2531 // implementation always returns its results in little endian, swap bytes
2533 MD5::MD5Result Result;
2535 return *reinterpret_cast<support::ulittle64_t *>(Result + 8);
2538 void DwarfDebug::addDwarfTypeUnitType(DwarfCompileUnit &CU,
2539 StringRef Identifier, DIE &RefDie,
2540 DICompositeType CTy) {
2541 // Fast path if we're building some type units and one has already used the
2542 // address pool we know we're going to throw away all this work anyway, so
2543 // don't bother building dependent types.
2544 if (!TypeUnitsUnderConstruction.empty() && AddrPool.hasBeenUsed())
2547 const DwarfTypeUnit *&TU = DwarfTypeUnits[CTy];
2549 CU.addDIETypeSignature(RefDie, *TU);
2553 bool TopLevelType = TypeUnitsUnderConstruction.empty();
2554 AddrPool.resetUsedFlag();
2556 auto OwnedUnit = make_unique<DwarfTypeUnit>(
2557 InfoHolder.getUnits().size() + TypeUnitsUnderConstruction.size(), CU, Asm,
2558 this, &InfoHolder, getDwoLineTable(CU));
2559 DwarfTypeUnit &NewTU = *OwnedUnit;
2560 DIE &UnitDie = NewTU.getUnitDie();
2562 TypeUnitsUnderConstruction.push_back(
2563 std::make_pair(std::move(OwnedUnit), CTy));
2565 NewTU.addUInt(UnitDie, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
2568 uint64_t Signature = makeTypeSignature(Identifier);
2569 NewTU.setTypeSignature(Signature);
2571 if (useSplitDwarf())
2572 NewTU.initSection(Asm->getObjFileLowering().getDwarfTypesDWOSection(),
2573 DwarfTypesDWOSectionSym);
2575 CU.applyStmtList(UnitDie);
2577 Asm->getObjFileLowering().getDwarfTypesSection(Signature));
2580 NewTU.setType(NewTU.createTypeDIE(CTy));
2583 auto TypeUnitsToAdd = std::move(TypeUnitsUnderConstruction);
2584 TypeUnitsUnderConstruction.clear();
2586 // Types referencing entries in the address table cannot be placed in type
2588 if (AddrPool.hasBeenUsed()) {
2590 // Remove all the types built while building this type.
2591 // This is pessimistic as some of these types might not be dependent on
2592 // the type that used an address.
2593 for (const auto &TU : TypeUnitsToAdd)
2594 DwarfTypeUnits.erase(TU.second);
2596 // Construct this type in the CU directly.
2597 // This is inefficient because all the dependent types will be rebuilt
2598 // from scratch, including building them in type units, discovering that
2599 // they depend on addresses, throwing them out and rebuilding them.
2600 CU.constructTypeDIE(RefDie, CTy);
2604 // If the type wasn't dependent on fission addresses, finish adding the type
2605 // and all its dependent types.
2606 for (auto &TU : TypeUnitsToAdd)
2607 InfoHolder.addUnit(std::move(TU.first));
2609 CU.addDIETypeSignature(RefDie, NewTU);
2612 void DwarfDebug::attachLowHighPC(DwarfCompileUnit &Unit, DIE &D,
2613 const MCSymbol *Begin, const MCSymbol *End) {
2614 assert(Begin && "Begin label should not be null!");
2615 assert(End && "End label should not be null!");
2616 assert(Begin->isDefined() && "Invalid starting label");
2617 assert(End->isDefined() && "Invalid end label");
2619 Unit.addLabelAddress(D, dwarf::DW_AT_low_pc, Begin);
2620 if (DwarfVersion < 4)
2621 Unit.addLabelAddress(D, dwarf::DW_AT_high_pc, End);
2623 Unit.addLabelDelta(D, dwarf::DW_AT_high_pc, End, Begin);
2626 // Accelerator table mutators - add each name along with its companion
2627 // DIE to the proper table while ensuring that the name that we're going
2628 // to reference is in the string table. We do this since the names we
2629 // add may not only be identical to the names in the DIE.
2630 void DwarfDebug::addAccelName(StringRef Name, const DIE &Die) {
2631 if (!useDwarfAccelTables())
2633 AccelNames.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2637 void DwarfDebug::addAccelObjC(StringRef Name, const DIE &Die) {
2638 if (!useDwarfAccelTables())
2640 AccelObjC.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2644 void DwarfDebug::addAccelNamespace(StringRef Name, const DIE &Die) {
2645 if (!useDwarfAccelTables())
2647 AccelNamespace.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2651 void DwarfDebug::addAccelType(StringRef Name, const DIE &Die, char Flags) {
2652 if (!useDwarfAccelTables())
2654 AccelTypes.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),