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 // Only include DW_AT_frame_base in full debug info
323 if (SPCU.getCUNode().getEmissionKind() != DIBuilder::LineTablesOnly) {
324 const TargetRegisterInfo *RI =
325 Asm->TM.getSubtargetImpl()->getRegisterInfo();
326 MachineLocation Location(RI->getFrameRegister(*Asm->MF));
327 SPCU.addAddress(*SPDie, dwarf::DW_AT_frame_base, Location);
330 // Add name to the name table, we do this here because we're guaranteed
331 // to have concrete versions of our DW_TAG_subprogram nodes.
332 addSubprogramNames(SP, *SPDie);
337 /// Check whether we should create a DIE for the given Scope, return true
338 /// if we don't create a DIE (the corresponding DIE is null).
339 bool DwarfDebug::isLexicalScopeDIENull(LexicalScope *Scope) {
340 if (Scope->isAbstractScope())
343 // We don't create a DIE if there is no Range.
344 const SmallVectorImpl<InsnRange> &Ranges = Scope->getRanges();
348 if (Ranges.size() > 1)
351 // We don't create a DIE if we have a single Range and the end label
353 return !getLabelAfterInsn(Ranges.front().second);
356 static void addSectionLabel(AsmPrinter &Asm, DwarfUnit &U, DIE &D,
357 dwarf::Attribute A, const MCSymbol *L,
358 const MCSymbol *Sec) {
359 if (Asm.MAI->doesDwarfUseRelocationsAcrossSections())
360 U.addSectionLabel(D, A, L);
362 U.addSectionDelta(D, A, L, Sec);
365 void DwarfDebug::addScopeRangeList(DwarfCompileUnit &TheCU, DIE &ScopeDIE,
366 const SmallVectorImpl<InsnRange> &Range) {
367 // Emit offset in .debug_range as a relocatable label. emitDIE will handle
368 // emitting it appropriately.
369 MCSymbol *RangeSym = Asm->GetTempSymbol("debug_ranges", GlobalRangeCount++);
371 // Under fission, ranges are specified by constant offsets relative to the
372 // CU's DW_AT_GNU_ranges_base.
374 TheCU.addSectionDelta(ScopeDIE, dwarf::DW_AT_ranges, RangeSym,
375 DwarfDebugRangeSectionSym);
377 addSectionLabel(*Asm, TheCU, ScopeDIE, dwarf::DW_AT_ranges, RangeSym,
378 DwarfDebugRangeSectionSym);
380 RangeSpanList List(RangeSym);
381 for (const InsnRange &R : Range) {
382 RangeSpan Span(getLabelBeforeInsn(R.first), getLabelAfterInsn(R.second));
383 List.addRange(std::move(Span));
386 // Add the range list to the set of ranges to be emitted.
387 TheCU.addRangeList(std::move(List));
390 void DwarfDebug::attachRangesOrLowHighPC(DwarfCompileUnit &TheCU, DIE &Die,
391 const SmallVectorImpl<InsnRange> &Ranges) {
392 assert(!Ranges.empty());
393 if (Ranges.size() == 1)
394 attachLowHighPC(TheCU, Die, getLabelBeforeInsn(Ranges.front().first),
395 getLabelAfterInsn(Ranges.front().second));
397 addScopeRangeList(TheCU, Die, Ranges);
400 // Construct new DW_TAG_lexical_block for this scope and attach
401 // DW_AT_low_pc/DW_AT_high_pc labels.
403 DwarfDebug::constructLexicalScopeDIE(DwarfCompileUnit &TheCU,
404 LexicalScope *Scope) {
405 if (isLexicalScopeDIENull(Scope))
408 auto ScopeDIE = make_unique<DIE>(dwarf::DW_TAG_lexical_block);
409 if (Scope->isAbstractScope())
412 attachRangesOrLowHighPC(TheCU, *ScopeDIE, Scope->getRanges());
417 // This scope represents inlined body of a function. Construct DIE to
418 // represent this concrete inlined copy of the function.
420 DwarfDebug::constructInlinedScopeDIE(DwarfCompileUnit &TheCU,
421 LexicalScope *Scope) {
422 assert(Scope->getScopeNode());
423 DIScope DS(Scope->getScopeNode());
424 DISubprogram InlinedSP = getDISubprogram(DS);
425 // Find the subprogram's DwarfCompileUnit in the SPMap in case the subprogram
426 // was inlined from another compile unit.
427 DIE *OriginDIE = AbstractSPDies[InlinedSP];
428 assert(OriginDIE && "Unable to find original DIE for an inlined subprogram.");
430 auto ScopeDIE = make_unique<DIE>(dwarf::DW_TAG_inlined_subroutine);
431 TheCU.addDIEEntry(*ScopeDIE, dwarf::DW_AT_abstract_origin, *OriginDIE);
433 attachRangesOrLowHighPC(TheCU, *ScopeDIE, Scope->getRanges());
435 InlinedSubprogramDIEs.insert(OriginDIE);
437 // Add the call site information to the DIE.
438 DILocation DL(Scope->getInlinedAt());
439 TheCU.addUInt(*ScopeDIE, dwarf::DW_AT_call_file, None,
440 TheCU.getOrCreateSourceID(DL.getFilename(), DL.getDirectory()));
441 TheCU.addUInt(*ScopeDIE, dwarf::DW_AT_call_line, None, DL.getLineNumber());
443 // Add name to the name table, we do this here because we're guaranteed
444 // to have concrete versions of our DW_TAG_inlined_subprogram nodes.
445 addSubprogramNames(InlinedSP, *ScopeDIE);
450 static std::unique_ptr<DIE> constructVariableDIE(DwarfCompileUnit &TheCU,
452 const LexicalScope &Scope,
453 DIE *&ObjectPointer) {
454 auto Var = TheCU.constructVariableDIE(DV, Scope.isAbstractScope());
455 if (DV.isObjectPointer())
456 ObjectPointer = Var.get();
460 DIE *DwarfDebug::createScopeChildrenDIE(
461 DwarfCompileUnit &TheCU, LexicalScope *Scope,
462 SmallVectorImpl<std::unique_ptr<DIE>> &Children,
463 unsigned *ChildScopeCount) {
464 DIE *ObjectPointer = nullptr;
466 for (DbgVariable *DV : ScopeVariables.lookup(Scope))
467 Children.push_back(constructVariableDIE(TheCU, *DV, *Scope, ObjectPointer));
469 unsigned ChildCountWithoutScopes = Children.size();
471 for (LexicalScope *LS : Scope->getChildren())
472 constructScopeDIE(TheCU, LS, Children);
475 *ChildScopeCount = Children.size() - ChildCountWithoutScopes;
477 return ObjectPointer;
480 DIE *DwarfDebug::createAndAddScopeChildren(DwarfCompileUnit &TheCU,
481 LexicalScope *Scope, DIE &ScopeDIE) {
482 // We create children when the scope DIE is not null.
483 SmallVector<std::unique_ptr<DIE>, 8> Children;
484 DIE *ObjectPointer = createScopeChildrenDIE(TheCU, Scope, Children);
487 for (auto &I : Children)
488 ScopeDIE.addChild(std::move(I));
490 return ObjectPointer;
493 void DwarfDebug::constructAbstractSubprogramScopeDIE(DwarfCompileUnit &TheCU,
494 LexicalScope *Scope) {
495 assert(Scope && Scope->getScopeNode());
496 assert(Scope->isAbstractScope());
497 assert(!Scope->getInlinedAt());
499 DISubprogram SP(Scope->getScopeNode());
501 ProcessedSPNodes.insert(SP);
503 DIE *&AbsDef = AbstractSPDies[SP];
507 // Find the subprogram's DwarfCompileUnit in the SPMap in case the subprogram
508 // was inlined from another compile unit.
509 DwarfCompileUnit &SPCU = *SPMap[SP];
512 // Some of this is duplicated from DwarfUnit::getOrCreateSubprogramDIE, with
513 // the important distinction that the DIDescriptor is not associated with the
514 // DIE (since the DIDescriptor will be associated with the concrete DIE, if
515 // any). It could be refactored to some common utility function.
516 if (DISubprogram SPDecl = SP.getFunctionDeclaration()) {
517 ContextDIE = &SPCU.getUnitDie();
518 SPCU.getOrCreateSubprogramDIE(SPDecl);
520 ContextDIE = SPCU.getOrCreateContextDIE(resolve(SP.getContext()));
522 // Passing null as the associated DIDescriptor because the abstract definition
523 // shouldn't be found by lookup.
524 AbsDef = &SPCU.createAndAddDIE(dwarf::DW_TAG_subprogram, *ContextDIE,
526 SPCU.applySubprogramAttributesToDefinition(SP, *AbsDef);
528 SPCU.addUInt(*AbsDef, dwarf::DW_AT_inline, None, dwarf::DW_INL_inlined);
529 if (DIE *ObjectPointer = createAndAddScopeChildren(SPCU, Scope, *AbsDef))
530 SPCU.addDIEEntry(*AbsDef, dwarf::DW_AT_object_pointer, *ObjectPointer);
533 DIE &DwarfDebug::constructSubprogramScopeDIE(DwarfCompileUnit &TheCU,
534 LexicalScope *Scope) {
535 assert(Scope && Scope->getScopeNode());
536 assert(!Scope->getInlinedAt());
537 assert(!Scope->isAbstractScope());
538 DISubprogram Sub(Scope->getScopeNode());
540 assert(Sub.isSubprogram());
542 ProcessedSPNodes.insert(Sub);
544 DIE &ScopeDIE = updateSubprogramScopeDIE(TheCU, Sub);
546 // Collect arguments for current function.
547 assert(LScopes.isCurrentFunctionScope(Scope));
548 DIE *ObjectPointer = nullptr;
549 for (DbgVariable *ArgDV : CurrentFnArguments)
552 constructVariableDIE(TheCU, *ArgDV, *Scope, ObjectPointer));
554 // If this is a variadic function, add an unspecified parameter.
555 DITypeArray FnArgs = Sub.getType().getTypeArray();
556 // If we have a single element of null, it is a function that returns void.
557 // If we have more than one elements and the last one is null, it is a
558 // variadic function.
559 if (FnArgs.getNumElements() > 1 &&
560 !FnArgs.getElement(FnArgs.getNumElements() - 1))
561 ScopeDIE.addChild(make_unique<DIE>(dwarf::DW_TAG_unspecified_parameters));
563 // Collect lexical scope children first.
564 // ObjectPointer might be a local (non-argument) local variable if it's a
565 // block's synthetic this pointer.
566 if (DIE *BlockObjPtr = createAndAddScopeChildren(TheCU, Scope, ScopeDIE)) {
567 assert(!ObjectPointer && "multiple object pointers can't be described");
568 ObjectPointer = BlockObjPtr;
572 TheCU.addDIEEntry(ScopeDIE, dwarf::DW_AT_object_pointer, *ObjectPointer);
577 // Construct a DIE for this scope.
578 void DwarfDebug::constructScopeDIE(
579 DwarfCompileUnit &TheCU, LexicalScope *Scope,
580 SmallVectorImpl<std::unique_ptr<DIE>> &FinalChildren) {
581 if (!Scope || !Scope->getScopeNode())
584 DIScope DS(Scope->getScopeNode());
586 assert((Scope->getInlinedAt() || !DS.isSubprogram()) &&
587 "Only handle inlined subprograms here, use "
588 "constructSubprogramScopeDIE for non-inlined "
591 SmallVector<std::unique_ptr<DIE>, 8> Children;
593 // We try to create the scope DIE first, then the children DIEs. This will
594 // avoid creating un-used children then removing them later when we find out
595 // the scope DIE is null.
596 std::unique_ptr<DIE> ScopeDIE;
597 if (Scope->getParent() && DS.isSubprogram()) {
598 ScopeDIE = constructInlinedScopeDIE(TheCU, Scope);
601 // We create children when the scope DIE is not null.
602 createScopeChildrenDIE(TheCU, Scope, Children);
604 // Early exit when we know the scope DIE is going to be null.
605 if (isLexicalScopeDIENull(Scope))
608 unsigned ChildScopeCount;
610 // We create children here when we know the scope DIE is not going to be
611 // null and the children will be added to the scope DIE.
612 createScopeChildrenDIE(TheCU, Scope, Children, &ChildScopeCount);
614 // There is no need to emit empty lexical block DIE.
615 std::pair<ImportedEntityMap::const_iterator,
616 ImportedEntityMap::const_iterator> Range =
617 std::equal_range(ScopesWithImportedEntities.begin(),
618 ScopesWithImportedEntities.end(),
619 std::pair<const MDNode *, const MDNode *>(DS, nullptr),
621 for (ImportedEntityMap::const_iterator i = Range.first; i != Range.second;
624 constructImportedEntityDIE(TheCU, DIImportedEntity(i->second)));
625 // If there are only other scopes as children, put them directly in the
626 // parent instead, as this scope would serve no purpose.
627 if (Children.size() == ChildScopeCount) {
628 FinalChildren.insert(FinalChildren.end(),
629 std::make_move_iterator(Children.begin()),
630 std::make_move_iterator(Children.end()));
633 ScopeDIE = constructLexicalScopeDIE(TheCU, Scope);
634 assert(ScopeDIE && "Scope DIE should not be null.");
638 for (auto &I : Children)
639 ScopeDIE->addChild(std::move(I));
641 FinalChildren.push_back(std::move(ScopeDIE));
644 void DwarfDebug::addGnuPubAttributes(DwarfUnit &U, DIE &D) const {
645 if (!GenerateGnuPubSections)
648 U.addFlag(D, dwarf::DW_AT_GNU_pubnames);
651 // Create new DwarfCompileUnit for the given metadata node with tag
652 // DW_TAG_compile_unit.
653 DwarfCompileUnit &DwarfDebug::constructDwarfCompileUnit(DICompileUnit DIUnit) {
654 StringRef FN = DIUnit.getFilename();
655 CompilationDir = DIUnit.getDirectory();
657 auto OwnedUnit = make_unique<DwarfCompileUnit>(
658 InfoHolder.getUnits().size(), DIUnit, Asm, this, &InfoHolder);
659 DwarfCompileUnit &NewCU = *OwnedUnit;
660 DIE &Die = NewCU.getUnitDie();
661 InfoHolder.addUnit(std::move(OwnedUnit));
663 // LTO with assembly output shares a single line table amongst multiple CUs.
664 // To avoid the compilation directory being ambiguous, let the line table
665 // explicitly describe the directory of all files, never relying on the
666 // compilation directory.
667 if (!Asm->OutStreamer.hasRawTextSupport() || SingleCU)
668 Asm->OutStreamer.getContext().setMCLineTableCompilationDir(
669 NewCU.getUniqueID(), CompilationDir);
671 NewCU.addString(Die, dwarf::DW_AT_producer, DIUnit.getProducer());
672 NewCU.addUInt(Die, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
673 DIUnit.getLanguage());
674 NewCU.addString(Die, dwarf::DW_AT_name, FN);
676 if (!useSplitDwarf()) {
677 NewCU.initStmtList(DwarfLineSectionSym);
679 // If we're using split dwarf the compilation dir is going to be in the
680 // skeleton CU and so we don't need to duplicate it here.
681 if (!CompilationDir.empty())
682 NewCU.addString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
684 addGnuPubAttributes(NewCU, Die);
687 if (DIUnit.isOptimized())
688 NewCU.addFlag(Die, dwarf::DW_AT_APPLE_optimized);
690 StringRef Flags = DIUnit.getFlags();
692 NewCU.addString(Die, dwarf::DW_AT_APPLE_flags, Flags);
694 if (unsigned RVer = DIUnit.getRunTimeVersion())
695 NewCU.addUInt(Die, dwarf::DW_AT_APPLE_major_runtime_vers,
696 dwarf::DW_FORM_data1, RVer);
701 if (useSplitDwarf()) {
702 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoDWOSection(),
703 DwarfInfoDWOSectionSym);
704 NewCU.setSkeleton(constructSkeletonCU(NewCU));
706 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoSection(),
707 DwarfInfoSectionSym);
709 CUMap.insert(std::make_pair(DIUnit, &NewCU));
710 CUDieMap.insert(std::make_pair(&Die, &NewCU));
714 void DwarfDebug::constructAndAddImportedEntityDIE(DwarfCompileUnit &TheCU,
716 DIImportedEntity Module(N);
717 assert(Module.Verify());
718 if (DIE *D = TheCU.getOrCreateContextDIE(Module.getContext()))
719 D->addChild(constructImportedEntityDIE(TheCU, Module));
723 DwarfDebug::constructImportedEntityDIE(DwarfCompileUnit &TheCU,
724 const DIImportedEntity &Module) {
725 assert(Module.Verify() &&
726 "Use one of the MDNode * overloads to handle invalid metadata");
727 std::unique_ptr<DIE> IMDie = make_unique<DIE>((dwarf::Tag)Module.getTag());
728 TheCU.insertDIE(Module, IMDie.get());
730 DIDescriptor Entity = resolve(Module.getEntity());
731 if (Entity.isNameSpace())
732 EntityDie = TheCU.getOrCreateNameSpace(DINameSpace(Entity));
733 else if (Entity.isSubprogram())
734 EntityDie = TheCU.getOrCreateSubprogramDIE(DISubprogram(Entity));
735 else if (Entity.isType())
736 EntityDie = TheCU.getOrCreateTypeDIE(DIType(Entity));
738 EntityDie = TheCU.getDIE(Entity);
740 TheCU.addSourceLine(*IMDie, Module.getLineNumber(),
741 Module.getContext().getFilename(),
742 Module.getContext().getDirectory());
743 TheCU.addDIEEntry(*IMDie, dwarf::DW_AT_import, *EntityDie);
744 StringRef Name = Module.getName();
746 TheCU.addString(*IMDie, dwarf::DW_AT_name, Name);
751 // Emit all Dwarf sections that should come prior to the content. Create
752 // global DIEs and emit initial debug info sections. This is invoked by
753 // the target AsmPrinter.
754 void DwarfDebug::beginModule() {
755 if (DisableDebugInfoPrinting)
758 const Module *M = MMI->getModule();
760 FunctionDIs = makeSubprogramMap(*M);
762 // If module has named metadata anchors then use them, otherwise scan the
763 // module using debug info finder to collect debug info.
764 NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
767 TypeIdentifierMap = generateDITypeIdentifierMap(CU_Nodes);
769 // Emit initial sections so we can reference labels later.
772 SingleCU = CU_Nodes->getNumOperands() == 1;
774 for (MDNode *N : CU_Nodes->operands()) {
775 DICompileUnit CUNode(N);
776 DwarfCompileUnit &CU = constructDwarfCompileUnit(CUNode);
777 DIArray ImportedEntities = CUNode.getImportedEntities();
778 for (unsigned i = 0, e = ImportedEntities.getNumElements(); i != e; ++i)
779 ScopesWithImportedEntities.push_back(std::make_pair(
780 DIImportedEntity(ImportedEntities.getElement(i)).getContext(),
781 ImportedEntities.getElement(i)));
782 std::sort(ScopesWithImportedEntities.begin(),
783 ScopesWithImportedEntities.end(), less_first());
784 DIArray GVs = CUNode.getGlobalVariables();
785 for (unsigned i = 0, e = GVs.getNumElements(); i != e; ++i)
786 CU.getOrCreateGlobalVariableDIE(DIGlobalVariable(GVs.getElement(i)));
787 DIArray SPs = CUNode.getSubprograms();
788 for (unsigned i = 0, e = SPs.getNumElements(); i != e; ++i)
789 SPMap.insert(std::make_pair(SPs.getElement(i), &CU));
790 DIArray EnumTypes = CUNode.getEnumTypes();
791 for (unsigned i = 0, e = EnumTypes.getNumElements(); i != e; ++i) {
792 DIType Ty(EnumTypes.getElement(i));
793 // The enum types array by design contains pointers to
794 // MDNodes rather than DIRefs. Unique them here.
795 DIType UniqueTy(resolve(Ty.getRef()));
796 CU.getOrCreateTypeDIE(UniqueTy);
798 DIArray RetainedTypes = CUNode.getRetainedTypes();
799 for (unsigned i = 0, e = RetainedTypes.getNumElements(); i != e; ++i) {
800 DIType Ty(RetainedTypes.getElement(i));
801 // The retained types array by design contains pointers to
802 // MDNodes rather than DIRefs. Unique them here.
803 DIType UniqueTy(resolve(Ty.getRef()));
804 CU.getOrCreateTypeDIE(UniqueTy);
806 // Emit imported_modules last so that the relevant context is already
808 for (unsigned i = 0, e = ImportedEntities.getNumElements(); i != e; ++i)
809 constructAndAddImportedEntityDIE(CU, ImportedEntities.getElement(i));
812 // Tell MMI that we have debug info.
813 MMI->setDebugInfoAvailability(true);
815 // Prime section data.
816 SectionMap[Asm->getObjFileLowering().getTextSection()];
819 void DwarfDebug::finishVariableDefinitions() {
820 for (const auto &Var : ConcreteVariables) {
821 DIE *VariableDie = Var->getDIE();
823 // FIXME: Consider the time-space tradeoff of just storing the unit pointer
824 // in the ConcreteVariables list, rather than looking it up again here.
825 // DIE::getUnit isn't simple - it walks parent pointers, etc.
826 DwarfCompileUnit *Unit = lookupUnit(VariableDie->getUnit());
828 DbgVariable *AbsVar = getExistingAbstractVariable(Var->getVariable());
829 if (AbsVar && AbsVar->getDIE()) {
830 Unit->addDIEEntry(*VariableDie, dwarf::DW_AT_abstract_origin,
833 Unit->applyVariableAttributes(*Var, *VariableDie);
837 void DwarfDebug::finishSubprogramDefinitions() {
838 const Module *M = MMI->getModule();
840 NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
841 for (MDNode *N : CU_Nodes->operands()) {
842 DICompileUnit TheCU(N);
843 // Construct subprogram DIE and add variables DIEs.
844 DwarfCompileUnit *SPCU =
845 static_cast<DwarfCompileUnit *>(CUMap.lookup(TheCU));
846 DIArray Subprograms = TheCU.getSubprograms();
847 for (unsigned i = 0, e = Subprograms.getNumElements(); i != e; ++i) {
848 DISubprogram SP(Subprograms.getElement(i));
849 // Perhaps the subprogram is in another CU (such as due to comdat
850 // folding, etc), in which case ignore it here.
851 if (SPMap[SP] != SPCU)
853 DIE *D = SPCU->getDIE(SP);
854 if (DIE *AbsSPDIE = AbstractSPDies.lookup(SP)) {
856 // If this subprogram has an abstract definition, reference that
857 SPCU->addDIEEntry(*D, dwarf::DW_AT_abstract_origin, *AbsSPDIE);
859 if (!D && TheCU.getEmissionKind() != DIBuilder::LineTablesOnly)
860 // Lazily construct the subprogram if we didn't see either concrete or
861 // inlined versions during codegen. (except in -gmlt ^ where we want
862 // to omit these entirely)
863 D = SPCU->getOrCreateSubprogramDIE(SP);
865 // And attach the attributes
866 SPCU->applySubprogramAttributesToDefinition(SP, *D);
873 // Collect info for variables that were optimized out.
874 void DwarfDebug::collectDeadVariables() {
875 const Module *M = MMI->getModule();
877 if (NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu")) {
878 for (MDNode *N : CU_Nodes->operands()) {
879 DICompileUnit TheCU(N);
880 // Construct subprogram DIE and add variables DIEs.
881 DwarfCompileUnit *SPCU =
882 static_cast<DwarfCompileUnit *>(CUMap.lookup(TheCU));
883 assert(SPCU && "Unable to find Compile Unit!");
884 DIArray Subprograms = TheCU.getSubprograms();
885 for (unsigned i = 0, e = Subprograms.getNumElements(); i != e; ++i) {
886 DISubprogram SP(Subprograms.getElement(i));
887 if (ProcessedSPNodes.count(SP) != 0)
889 assert(SP.isSubprogram() &&
890 "CU's subprogram list contains a non-subprogram");
891 assert(SP.isDefinition() &&
892 "CU's subprogram list contains a subprogram declaration");
893 DIArray Variables = SP.getVariables();
894 if (Variables.getNumElements() == 0)
897 DIE *SPDIE = AbstractSPDies.lookup(SP);
899 SPDIE = SPCU->getDIE(SP);
901 for (unsigned vi = 0, ve = Variables.getNumElements(); vi != ve; ++vi) {
902 DIVariable DV(Variables.getElement(vi));
903 assert(DV.isVariable());
904 DbgVariable NewVar(DV, this);
905 auto VariableDie = SPCU->constructVariableDIE(NewVar);
906 SPCU->applyVariableAttributes(NewVar, *VariableDie);
907 SPDIE->addChild(std::move(VariableDie));
914 void DwarfDebug::finalizeModuleInfo() {
915 finishSubprogramDefinitions();
917 finishVariableDefinitions();
919 // Collect info for variables that were optimized out.
920 collectDeadVariables();
922 // Handle anything that needs to be done on a per-unit basis after
923 // all other generation.
924 for (const auto &TheU : getUnits()) {
925 // Emit DW_AT_containing_type attribute to connect types with their
926 // vtable holding type.
927 TheU->constructContainingTypeDIEs();
929 // Add CU specific attributes if we need to add any.
930 if (TheU->getUnitDie().getTag() == dwarf::DW_TAG_compile_unit) {
931 // If we're splitting the dwarf out now that we've got the entire
932 // CU then add the dwo id to it.
933 DwarfCompileUnit *SkCU =
934 static_cast<DwarfCompileUnit *>(TheU->getSkeleton());
935 if (useSplitDwarf()) {
936 // Emit a unique identifier for this CU.
937 uint64_t ID = DIEHash(Asm).computeCUSignature(TheU->getUnitDie());
938 TheU->addUInt(TheU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
939 dwarf::DW_FORM_data8, ID);
940 SkCU->addUInt(SkCU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
941 dwarf::DW_FORM_data8, ID);
943 // We don't keep track of which addresses are used in which CU so this
944 // is a bit pessimistic under LTO.
945 if (!AddrPool.isEmpty())
946 addSectionLabel(*Asm, *SkCU, SkCU->getUnitDie(),
947 dwarf::DW_AT_GNU_addr_base, DwarfAddrSectionSym,
948 DwarfAddrSectionSym);
949 if (!TheU->getRangeLists().empty())
950 addSectionLabel(*Asm, *SkCU, SkCU->getUnitDie(),
951 dwarf::DW_AT_GNU_ranges_base,
952 DwarfDebugRangeSectionSym, DwarfDebugRangeSectionSym);
955 // If we have code split among multiple sections or non-contiguous
956 // ranges of code then emit a DW_AT_ranges attribute on the unit that will
957 // remain in the .o file, otherwise add a DW_AT_low_pc.
958 // FIXME: We should use ranges allow reordering of code ala
959 // .subsections_via_symbols in mach-o. This would mean turning on
960 // ranges for all subprogram DIEs for mach-o.
961 DwarfCompileUnit &U =
962 SkCU ? *SkCU : static_cast<DwarfCompileUnit &>(*TheU);
963 unsigned NumRanges = TheU->getRanges().size();
966 addSectionLabel(*Asm, U, U.getUnitDie(), dwarf::DW_AT_ranges,
967 Asm->GetTempSymbol("cu_ranges", U.getUniqueID()),
968 DwarfDebugRangeSectionSym);
970 // A DW_AT_low_pc attribute may also be specified in combination with
971 // DW_AT_ranges to specify the default base address for use in
972 // location lists (see Section 2.6.2) and range lists (see Section
974 U.addUInt(U.getUnitDie(), dwarf::DW_AT_low_pc, dwarf::DW_FORM_addr,
977 RangeSpan &Range = TheU->getRanges().back();
978 attachLowHighPC(U, U.getUnitDie(), Range.getStart(), Range.getEnd());
984 // Compute DIE offsets and sizes.
985 InfoHolder.computeSizeAndOffsets();
987 SkeletonHolder.computeSizeAndOffsets();
990 void DwarfDebug::endSections() {
991 // Filter labels by section.
992 for (const SymbolCU &SCU : ArangeLabels) {
993 if (SCU.Sym->isInSection()) {
994 // Make a note of this symbol and it's section.
995 const MCSection *Section = &SCU.Sym->getSection();
996 if (!Section->getKind().isMetadata())
997 SectionMap[Section].push_back(SCU);
999 // Some symbols (e.g. common/bss on mach-o) can have no section but still
1000 // appear in the output. This sucks as we rely on sections to build
1001 // arange spans. We can do it without, but it's icky.
1002 SectionMap[nullptr].push_back(SCU);
1006 // Build a list of sections used.
1007 std::vector<const MCSection *> Sections;
1008 for (const auto &it : SectionMap) {
1009 const MCSection *Section = it.first;
1010 Sections.push_back(Section);
1013 // Sort the sections into order.
1014 // This is only done to ensure consistent output order across different runs.
1015 std::sort(Sections.begin(), Sections.end(), SectionSort);
1017 // Add terminating symbols for each section.
1018 for (unsigned ID = 0, E = Sections.size(); ID != E; ID++) {
1019 const MCSection *Section = Sections[ID];
1020 MCSymbol *Sym = nullptr;
1023 // We can't call MCSection::getLabelEndName, as it's only safe to do so
1024 // if we know the section name up-front. For user-created sections, the
1025 // resulting label may not be valid to use as a label. (section names can
1026 // use a greater set of characters on some systems)
1027 Sym = Asm->GetTempSymbol("debug_end", ID);
1028 Asm->OutStreamer.SwitchSection(Section);
1029 Asm->OutStreamer.EmitLabel(Sym);
1032 // Insert a final terminator.
1033 SectionMap[Section].push_back(SymbolCU(nullptr, Sym));
1037 // Emit all Dwarf sections that should come after the content.
1038 void DwarfDebug::endModule() {
1039 assert(CurFn == nullptr);
1040 assert(CurMI == nullptr);
1045 // End any existing sections.
1046 // TODO: Does this need to happen?
1049 // Finalize the debug info for the module.
1050 finalizeModuleInfo();
1054 // Emit all the DIEs into a debug info section.
1057 // Corresponding abbreviations into a abbrev section.
1058 emitAbbreviations();
1060 // Emit info into a debug aranges section.
1061 if (GenerateARangeSection)
1064 // Emit info into a debug ranges section.
1067 if (useSplitDwarf()) {
1070 emitDebugAbbrevDWO();
1073 // Emit DWO addresses.
1074 AddrPool.emit(*Asm, Asm->getObjFileLowering().getDwarfAddrSection());
1076 // Emit info into a debug loc section.
1079 // Emit info into the dwarf accelerator table sections.
1080 if (useDwarfAccelTables()) {
1083 emitAccelNamespaces();
1087 // Emit the pubnames and pubtypes sections if requested.
1088 if (HasDwarfPubSections) {
1089 emitDebugPubNames(GenerateGnuPubSections);
1090 emitDebugPubTypes(GenerateGnuPubSections);
1095 AbstractVariables.clear();
1097 // Reset these for the next Module if we have one.
1101 // Find abstract variable, if any, associated with Var.
1102 DbgVariable *DwarfDebug::getExistingAbstractVariable(const DIVariable &DV,
1103 DIVariable &Cleansed) {
1104 LLVMContext &Ctx = DV->getContext();
1105 // More then one inlined variable corresponds to one abstract variable.
1106 // FIXME: This duplication of variables when inlining should probably be
1107 // removed. It's done to allow each DIVariable to describe its location
1108 // because the DebugLoc on the dbg.value/declare isn't accurate. We should
1109 // make it accurate then remove this duplication/cleansing stuff.
1110 Cleansed = cleanseInlinedVariable(DV, Ctx);
1111 auto I = AbstractVariables.find(Cleansed);
1112 if (I != AbstractVariables.end())
1113 return I->second.get();
1117 DbgVariable *DwarfDebug::getExistingAbstractVariable(const DIVariable &DV) {
1118 DIVariable Cleansed;
1119 return getExistingAbstractVariable(DV, Cleansed);
1122 void DwarfDebug::createAbstractVariable(const DIVariable &Var,
1123 LexicalScope *Scope) {
1124 auto AbsDbgVariable = make_unique<DbgVariable>(Var, this);
1125 addScopeVariable(Scope, AbsDbgVariable.get());
1126 AbstractVariables[Var] = std::move(AbsDbgVariable);
1129 void DwarfDebug::ensureAbstractVariableIsCreated(const DIVariable &DV,
1130 const MDNode *ScopeNode) {
1131 DIVariable Cleansed = DV;
1132 if (getExistingAbstractVariable(DV, Cleansed))
1135 createAbstractVariable(Cleansed, LScopes.getOrCreateAbstractScope(ScopeNode));
1139 DwarfDebug::ensureAbstractVariableIsCreatedIfScoped(const DIVariable &DV,
1140 const MDNode *ScopeNode) {
1141 DIVariable Cleansed = DV;
1142 if (getExistingAbstractVariable(DV, Cleansed))
1145 if (LexicalScope *Scope = LScopes.findAbstractScope(ScopeNode))
1146 createAbstractVariable(Cleansed, Scope);
1149 // If Var is a current function argument then add it to CurrentFnArguments list.
1150 bool DwarfDebug::addCurrentFnArgument(DbgVariable *Var, LexicalScope *Scope) {
1151 if (!LScopes.isCurrentFunctionScope(Scope))
1153 DIVariable DV = Var->getVariable();
1154 if (DV.getTag() != dwarf::DW_TAG_arg_variable)
1156 unsigned ArgNo = DV.getArgNumber();
1160 size_t Size = CurrentFnArguments.size();
1162 CurrentFnArguments.resize(CurFn->getFunction()->arg_size());
1163 // llvm::Function argument size is not good indicator of how many
1164 // arguments does the function have at source level.
1166 CurrentFnArguments.resize(ArgNo * 2);
1167 assert(!CurrentFnArguments[ArgNo - 1]);
1168 CurrentFnArguments[ArgNo - 1] = Var;
1172 // Collect variable information from side table maintained by MMI.
1173 void DwarfDebug::collectVariableInfoFromMMITable(
1174 SmallPtrSetImpl<const MDNode *> &Processed) {
1175 for (const auto &VI : MMI->getVariableDbgInfo()) {
1178 Processed.insert(VI.Var);
1179 DIVariable DV(VI.Var);
1180 LexicalScope *Scope = LScopes.findLexicalScope(VI.Loc);
1182 // If variable scope is not found then skip this variable.
1186 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
1187 ConcreteVariables.push_back(make_unique<DbgVariable>(DV, this));
1188 DbgVariable *RegVar = ConcreteVariables.back().get();
1189 RegVar->setFrameIndex(VI.Slot);
1190 addScopeVariable(Scope, RegVar);
1194 // Get .debug_loc entry for the instruction range starting at MI.
1195 static DebugLocEntry::Value getDebugLocValue(const MachineInstr *MI) {
1196 const MDNode *Var = MI->getDebugVariable();
1198 assert(MI->getNumOperands() == 3);
1199 if (MI->getOperand(0).isReg()) {
1200 MachineLocation MLoc;
1201 // If the second operand is an immediate, this is a
1202 // register-indirect address.
1203 if (!MI->getOperand(1).isImm())
1204 MLoc.set(MI->getOperand(0).getReg());
1206 MLoc.set(MI->getOperand(0).getReg(), MI->getOperand(1).getImm());
1207 return DebugLocEntry::Value(Var, MLoc);
1209 if (MI->getOperand(0).isImm())
1210 return DebugLocEntry::Value(Var, MI->getOperand(0).getImm());
1211 if (MI->getOperand(0).isFPImm())
1212 return DebugLocEntry::Value(Var, MI->getOperand(0).getFPImm());
1213 if (MI->getOperand(0).isCImm())
1214 return DebugLocEntry::Value(Var, MI->getOperand(0).getCImm());
1216 llvm_unreachable("Unexpected 3 operand DBG_VALUE instruction!");
1219 /// Determine whether two variable pieces overlap.
1220 static bool piecesOverlap(DIVariable P1, DIVariable P2) {
1221 if (!P1.isVariablePiece() || !P2.isVariablePiece())
1223 unsigned l1 = P1.getPieceOffset();
1224 unsigned l2 = P2.getPieceOffset();
1225 unsigned r1 = l1 + P1.getPieceSize();
1226 unsigned r2 = l2 + P2.getPieceSize();
1227 // True where [l1,r1[ and [r1,r2[ overlap.
1228 return (l1 < r2) && (l2 < r1);
1231 /// Build the location list for all DBG_VALUEs in the function that
1232 /// describe the same variable. If the ranges of several independent
1233 /// pieces of the same variable overlap partially, split them up and
1234 /// combine the ranges. The resulting DebugLocEntries are will have
1235 /// strict monotonically increasing begin addresses and will never
1240 // Ranges History [var, loc, piece ofs size]
1241 // 0 | [x, (reg0, piece 0, 32)]
1242 // 1 | | [x, (reg1, piece 32, 32)] <- IsPieceOfPrevEntry
1244 // 3 | [clobber reg0]
1245 // 4 [x, (mem, piece 0, 64)] <- overlapping with both previous pieces of x.
1249 // [0-1] [x, (reg0, piece 0, 32)]
1250 // [1-3] [x, (reg0, piece 0, 32), (reg1, piece 32, 32)]
1251 // [3-4] [x, (reg1, piece 32, 32)]
1252 // [4- ] [x, (mem, piece 0, 64)]
1254 DwarfDebug::buildLocationList(SmallVectorImpl<DebugLocEntry> &DebugLoc,
1255 const DbgValueHistoryMap::InstrRanges &Ranges) {
1256 SmallVector<DebugLocEntry::Value, 4> OpenRanges;
1258 for (auto I = Ranges.begin(), E = Ranges.end(); I != E; ++I) {
1259 const MachineInstr *Begin = I->first;
1260 const MachineInstr *End = I->second;
1261 assert(Begin->isDebugValue() && "Invalid History entry");
1263 // Check if a variable is inaccessible in this range.
1264 if (Begin->getNumOperands() > 1 &&
1265 Begin->getOperand(0).isReg() && !Begin->getOperand(0).getReg()) {
1270 // If this piece overlaps with any open ranges, truncate them.
1271 DIVariable DIVar = Begin->getDebugVariable();
1272 auto Last = std::remove_if(OpenRanges.begin(), OpenRanges.end(),
1273 [&](DebugLocEntry::Value R) {
1274 return piecesOverlap(DIVar, R.getVariable());
1276 OpenRanges.erase(Last, OpenRanges.end());
1278 const MCSymbol *StartLabel = getLabelBeforeInsn(Begin);
1279 assert(StartLabel && "Forgot label before DBG_VALUE starting a range!");
1281 const MCSymbol *EndLabel;
1283 EndLabel = getLabelAfterInsn(End);
1284 else if (std::next(I) == Ranges.end())
1285 EndLabel = FunctionEndSym;
1287 EndLabel = getLabelBeforeInsn(std::next(I)->first);
1288 assert(EndLabel && "Forgot label after instruction ending a range!");
1290 DEBUG(dbgs() << "DotDebugLoc: " << *Begin << "\n");
1292 auto Value = getDebugLocValue(Begin);
1293 DebugLocEntry Loc(StartLabel, EndLabel, Value);
1294 bool couldMerge = false;
1296 // If this is a piece, it may belong to the current DebugLocEntry.
1297 if (DIVar.isVariablePiece()) {
1298 // Add this value to the list of open ranges.
1299 OpenRanges.push_back(Value);
1301 // Attempt to add the piece to the last entry.
1302 if (!DebugLoc.empty())
1303 if (DebugLoc.back().MergeValues(Loc))
1308 // Need to add a new DebugLocEntry. Add all values from still
1309 // valid non-overlapping pieces.
1310 if (OpenRanges.size())
1311 Loc.addValues(OpenRanges);
1313 DebugLoc.push_back(std::move(Loc));
1316 // Attempt to coalesce the ranges of two otherwise identical
1318 auto CurEntry = DebugLoc.rbegin();
1319 auto PrevEntry = std::next(CurEntry);
1320 if (PrevEntry != DebugLoc.rend() && PrevEntry->MergeRanges(*CurEntry))
1321 DebugLoc.pop_back();
1323 DEBUG(dbgs() << "Values:\n";
1324 for (auto Value : CurEntry->getValues())
1325 Value.getVariable()->dump();
1326 dbgs() << "-----\n");
1331 // Find variables for each lexical scope.
1333 DwarfDebug::collectVariableInfo(SmallPtrSetImpl<const MDNode *> &Processed) {
1334 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1335 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1337 // Grab the variable info that was squirreled away in the MMI side-table.
1338 collectVariableInfoFromMMITable(Processed);
1340 for (const auto &I : DbgValues) {
1341 DIVariable DV(I.first);
1342 if (Processed.count(DV))
1345 // Instruction ranges, specifying where DV is accessible.
1346 const auto &Ranges = I.second;
1350 LexicalScope *Scope = nullptr;
1351 if (MDNode *IA = DV.getInlinedAt()) {
1352 DebugLoc DL = DebugLoc::getFromDILocation(IA);
1353 Scope = LScopes.findInlinedScope(DebugLoc::get(
1354 DL.getLine(), DL.getCol(), DV.getContext(), IA));
1356 Scope = LScopes.findLexicalScope(DV.getContext());
1357 // If variable scope is not found then skip this variable.
1361 Processed.insert(getEntireVariable(DV));
1362 const MachineInstr *MInsn = Ranges.front().first;
1363 assert(MInsn->isDebugValue() && "History must begin with debug value");
1364 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
1365 ConcreteVariables.push_back(make_unique<DbgVariable>(MInsn, this));
1366 DbgVariable *RegVar = ConcreteVariables.back().get();
1367 addScopeVariable(Scope, RegVar);
1369 // Check if the first DBG_VALUE is valid for the rest of the function.
1370 if (Ranges.size() == 1 && Ranges.front().second == nullptr)
1373 // Handle multiple DBG_VALUE instructions describing one variable.
1374 RegVar->setDotDebugLocOffset(DotDebugLocEntries.size());
1376 DotDebugLocEntries.resize(DotDebugLocEntries.size() + 1);
1377 DebugLocList &LocList = DotDebugLocEntries.back();
1380 Asm->GetTempSymbol("debug_loc", DotDebugLocEntries.size() - 1);
1382 // Build the location list for this variable.
1383 buildLocationList(LocList.List, Ranges);
1386 // Collect info for variables that were optimized out.
1387 DIArray Variables = DISubprogram(FnScope->getScopeNode()).getVariables();
1388 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1389 DIVariable DV(Variables.getElement(i));
1390 assert(DV.isVariable());
1391 if (!Processed.insert(DV))
1393 if (LexicalScope *Scope = LScopes.findLexicalScope(DV.getContext())) {
1394 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
1395 ConcreteVariables.push_back(make_unique<DbgVariable>(DV, this));
1396 addScopeVariable(Scope, ConcreteVariables.back().get());
1401 // Return Label preceding the instruction.
1402 MCSymbol *DwarfDebug::getLabelBeforeInsn(const MachineInstr *MI) {
1403 MCSymbol *Label = LabelsBeforeInsn.lookup(MI);
1404 assert(Label && "Didn't insert label before instruction");
1408 // Return Label immediately following the instruction.
1409 MCSymbol *DwarfDebug::getLabelAfterInsn(const MachineInstr *MI) {
1410 return LabelsAfterInsn.lookup(MI);
1413 // Process beginning of an instruction.
1414 void DwarfDebug::beginInstruction(const MachineInstr *MI) {
1415 assert(CurMI == nullptr);
1417 // Check if source location changes, but ignore DBG_VALUE locations.
1418 if (!MI->isDebugValue()) {
1419 DebugLoc DL = MI->getDebugLoc();
1420 if (DL != PrevInstLoc && (!DL.isUnknown() || UnknownLocations)) {
1423 if (DL == PrologEndLoc) {
1424 Flags |= DWARF2_FLAG_PROLOGUE_END;
1425 PrologEndLoc = DebugLoc();
1427 if (PrologEndLoc.isUnknown())
1428 Flags |= DWARF2_FLAG_IS_STMT;
1430 if (!DL.isUnknown()) {
1431 const MDNode *Scope = DL.getScope(Asm->MF->getFunction()->getContext());
1432 recordSourceLine(DL.getLine(), DL.getCol(), Scope, Flags);
1434 recordSourceLine(0, 0, nullptr, 0);
1438 // Insert labels where requested.
1439 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1440 LabelsBeforeInsn.find(MI);
1443 if (I == LabelsBeforeInsn.end())
1446 // Label already assigned.
1451 PrevLabel = MMI->getContext().CreateTempSymbol();
1452 Asm->OutStreamer.EmitLabel(PrevLabel);
1454 I->second = PrevLabel;
1457 // Process end of an instruction.
1458 void DwarfDebug::endInstruction() {
1459 assert(CurMI != nullptr);
1460 // Don't create a new label after DBG_VALUE instructions.
1461 // They don't generate code.
1462 if (!CurMI->isDebugValue())
1463 PrevLabel = nullptr;
1465 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1466 LabelsAfterInsn.find(CurMI);
1470 if (I == LabelsAfterInsn.end())
1473 // Label already assigned.
1477 // We need a label after this instruction.
1479 PrevLabel = MMI->getContext().CreateTempSymbol();
1480 Asm->OutStreamer.EmitLabel(PrevLabel);
1482 I->second = PrevLabel;
1485 // Each LexicalScope has first instruction and last instruction to mark
1486 // beginning and end of a scope respectively. Create an inverse map that list
1487 // scopes starts (and ends) with an instruction. One instruction may start (or
1488 // end) multiple scopes. Ignore scopes that are not reachable.
1489 void DwarfDebug::identifyScopeMarkers() {
1490 SmallVector<LexicalScope *, 4> WorkList;
1491 WorkList.push_back(LScopes.getCurrentFunctionScope());
1492 while (!WorkList.empty()) {
1493 LexicalScope *S = WorkList.pop_back_val();
1495 const SmallVectorImpl<LexicalScope *> &Children = S->getChildren();
1496 if (!Children.empty())
1497 WorkList.append(Children.begin(), Children.end());
1499 if (S->isAbstractScope())
1502 for (const InsnRange &R : S->getRanges()) {
1503 assert(R.first && "InsnRange does not have first instruction!");
1504 assert(R.second && "InsnRange does not have second instruction!");
1505 requestLabelBeforeInsn(R.first);
1506 requestLabelAfterInsn(R.second);
1511 static DebugLoc findPrologueEndLoc(const MachineFunction *MF) {
1512 // First known non-DBG_VALUE and non-frame setup location marks
1513 // the beginning of the function body.
1514 for (const auto &MBB : *MF)
1515 for (const auto &MI : MBB)
1516 if (!MI.isDebugValue() && !MI.getFlag(MachineInstr::FrameSetup) &&
1517 !MI.getDebugLoc().isUnknown())
1518 return MI.getDebugLoc();
1522 // Gather pre-function debug information. Assumes being called immediately
1523 // after the function entry point has been emitted.
1524 void DwarfDebug::beginFunction(const MachineFunction *MF) {
1527 // If there's no debug info for the function we're not going to do anything.
1528 if (!MMI->hasDebugInfo())
1531 auto DI = FunctionDIs.find(MF->getFunction());
1532 if (DI == FunctionDIs.end())
1535 // Grab the lexical scopes for the function, if we don't have any of those
1536 // then we're not going to be able to do anything.
1537 LScopes.initialize(*MF);
1538 if (LScopes.empty())
1541 assert(DbgValues.empty() && "DbgValues map wasn't cleaned!");
1543 // Make sure that each lexical scope will have a begin/end label.
1544 identifyScopeMarkers();
1546 // Set DwarfDwarfCompileUnitID in MCContext to the Compile Unit this function
1547 // belongs to so that we add to the correct per-cu line table in the
1549 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1550 // FnScope->getScopeNode() and DI->second should represent the same function,
1551 // though they may not be the same MDNode due to inline functions merged in
1552 // LTO where the debug info metadata still differs (either due to distinct
1553 // written differences - two versions of a linkonce_odr function
1554 // written/copied into two separate files, or some sub-optimal metadata that
1555 // isn't structurally identical (see: file path/name info from clang, which
1556 // includes the directory of the cpp file being built, even when the file name
1557 // is absolute (such as an <> lookup header)))
1558 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1559 assert(TheCU && "Unable to find compile unit!");
1560 if (Asm->OutStreamer.hasRawTextSupport())
1561 // Use a single line table if we are generating assembly.
1562 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1564 Asm->OutStreamer.getContext().setDwarfCompileUnitID(TheCU->getUniqueID());
1566 // Emit a label for the function so that we have a beginning address.
1567 FunctionBeginSym = Asm->GetTempSymbol("func_begin", Asm->getFunctionNumber());
1568 // Assumes in correct section after the entry point.
1569 Asm->OutStreamer.EmitLabel(FunctionBeginSym);
1571 // Calculate history for local variables.
1572 calculateDbgValueHistory(MF, Asm->TM.getSubtargetImpl()->getRegisterInfo(),
1575 // Request labels for the full history.
1576 for (const auto &I : DbgValues) {
1577 const auto &Ranges = I.second;
1581 // The first mention of a function argument gets the FunctionBeginSym
1582 // label, so arguments are visible when breaking at function entry.
1583 DIVariable DV(Ranges.front().first->getDebugVariable());
1584 if (DV.isVariable() && DV.getTag() == dwarf::DW_TAG_arg_variable &&
1585 getDISubprogram(DV.getContext()).describes(MF->getFunction())) {
1586 if (!DV.isVariablePiece())
1587 LabelsBeforeInsn[Ranges.front().first] = FunctionBeginSym;
1589 // Mark all non-overlapping initial pieces.
1590 for (auto I = Ranges.begin(); I != Ranges.end(); ++I) {
1591 DIVariable Piece = I->first->getDebugVariable();
1592 if (std::all_of(Ranges.begin(), I,
1593 [&](DbgValueHistoryMap::InstrRange Pred){
1594 return !piecesOverlap(Piece, Pred.first->getDebugVariable());
1596 LabelsBeforeInsn[I->first] = FunctionBeginSym;
1603 for (const auto &Range : Ranges) {
1604 requestLabelBeforeInsn(Range.first);
1606 requestLabelAfterInsn(Range.second);
1610 PrevInstLoc = DebugLoc();
1611 PrevLabel = FunctionBeginSym;
1613 // Record beginning of function.
1614 PrologEndLoc = findPrologueEndLoc(MF);
1615 if (!PrologEndLoc.isUnknown()) {
1616 DebugLoc FnStartDL =
1617 PrologEndLoc.getFnDebugLoc(MF->getFunction()->getContext());
1619 FnStartDL.getLine(), FnStartDL.getCol(),
1620 FnStartDL.getScope(MF->getFunction()->getContext()),
1621 // We'd like to list the prologue as "not statements" but GDB behaves
1622 // poorly if we do that. Revisit this with caution/GDB (7.5+) testing.
1623 DWARF2_FLAG_IS_STMT);
1627 void DwarfDebug::addScopeVariable(LexicalScope *LS, DbgVariable *Var) {
1628 if (addCurrentFnArgument(Var, LS))
1630 SmallVectorImpl<DbgVariable *> &Vars = ScopeVariables[LS];
1631 DIVariable DV = Var->getVariable();
1632 // Variables with positive arg numbers are parameters.
1633 if (unsigned ArgNum = DV.getArgNumber()) {
1634 // Keep all parameters in order at the start of the variable list to ensure
1635 // function types are correct (no out-of-order parameters)
1637 // This could be improved by only doing it for optimized builds (unoptimized
1638 // builds have the right order to begin with), searching from the back (this
1639 // would catch the unoptimized case quickly), or doing a binary search
1640 // rather than linear search.
1641 SmallVectorImpl<DbgVariable *>::iterator I = Vars.begin();
1642 while (I != Vars.end()) {
1643 unsigned CurNum = (*I)->getVariable().getArgNumber();
1644 // A local (non-parameter) variable has been found, insert immediately
1648 // A later indexed parameter has been found, insert immediately before it.
1649 if (CurNum > ArgNum)
1653 Vars.insert(I, Var);
1657 Vars.push_back(Var);
1660 // Gather and emit post-function debug information.
1661 void DwarfDebug::endFunction(const MachineFunction *MF) {
1662 // Every beginFunction(MF) call should be followed by an endFunction(MF) call,
1663 // though the beginFunction may not be called at all.
1664 // We should handle both cases.
1668 assert(CurFn == MF);
1669 assert(CurFn != nullptr);
1671 if (!MMI->hasDebugInfo() || LScopes.empty() ||
1672 !FunctionDIs.count(MF->getFunction())) {
1673 // If we don't have a lexical scope for this function then there will
1674 // be a hole in the range information. Keep note of this by setting the
1675 // previously used section to nullptr.
1681 // Define end label for subprogram.
1682 FunctionEndSym = Asm->GetTempSymbol("func_end", Asm->getFunctionNumber());
1683 // Assumes in correct section after the entry point.
1684 Asm->OutStreamer.EmitLabel(FunctionEndSym);
1686 // Set DwarfDwarfCompileUnitID in MCContext to default value.
1687 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1689 SmallPtrSet<const MDNode *, 16> ProcessedVars;
1690 collectVariableInfo(ProcessedVars);
1692 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1693 DwarfCompileUnit &TheCU = *SPMap.lookup(FnScope->getScopeNode());
1695 // Add the range of this function to the list of ranges for the CU.
1696 TheCU.addRange(RangeSpan(FunctionBeginSym, FunctionEndSym));
1698 // Under -gmlt, skip building the subprogram if there are no inlined
1699 // subroutines inside it.
1700 if (TheCU.getCUNode().getEmissionKind() == DIBuilder::LineTablesOnly &&
1701 LScopes.getAbstractScopesList().empty()) {
1702 assert(ScopeVariables.empty());
1703 assert(CurrentFnArguments.empty());
1704 assert(DbgValues.empty());
1705 assert(AbstractVariables.empty());
1706 LabelsBeforeInsn.clear();
1707 LabelsAfterInsn.clear();
1708 PrevLabel = nullptr;
1713 // Construct abstract scopes.
1714 for (LexicalScope *AScope : LScopes.getAbstractScopesList()) {
1715 DISubprogram SP(AScope->getScopeNode());
1716 assert(SP.isSubprogram());
1717 // Collect info for variables that were optimized out.
1718 DIArray Variables = SP.getVariables();
1719 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1720 DIVariable DV(Variables.getElement(i));
1721 assert(DV && DV.isVariable());
1722 if (!ProcessedVars.insert(DV))
1724 ensureAbstractVariableIsCreated(DV, DV.getContext());
1726 constructAbstractSubprogramScopeDIE(TheCU, AScope);
1729 DIE &CurFnDIE = constructSubprogramScopeDIE(TheCU, FnScope);
1730 if (!CurFn->getTarget().Options.DisableFramePointerElim(*CurFn))
1731 TheCU.addFlag(CurFnDIE, dwarf::DW_AT_APPLE_omit_frame_ptr);
1734 // Ownership of DbgVariables is a bit subtle - ScopeVariables owns all the
1735 // DbgVariables except those that are also in AbstractVariables (since they
1736 // can be used cross-function)
1737 ScopeVariables.clear();
1738 CurrentFnArguments.clear();
1740 LabelsBeforeInsn.clear();
1741 LabelsAfterInsn.clear();
1742 PrevLabel = nullptr;
1746 // Register a source line with debug info. Returns the unique label that was
1747 // emitted and which provides correspondence to the source line list.
1748 void DwarfDebug::recordSourceLine(unsigned Line, unsigned Col, const MDNode *S,
1753 unsigned Discriminator = 0;
1754 if (DIScope Scope = DIScope(S)) {
1755 assert(Scope.isScope());
1756 Fn = Scope.getFilename();
1757 Dir = Scope.getDirectory();
1758 if (Scope.isLexicalBlockFile())
1759 Discriminator = DILexicalBlockFile(S).getDiscriminator();
1761 unsigned CUID = Asm->OutStreamer.getContext().getDwarfCompileUnitID();
1762 Src = static_cast<DwarfCompileUnit &>(*InfoHolder.getUnits()[CUID])
1763 .getOrCreateSourceID(Fn, Dir);
1765 Asm->OutStreamer.EmitDwarfLocDirective(Src, Line, Col, Flags, 0,
1769 //===----------------------------------------------------------------------===//
1771 //===----------------------------------------------------------------------===//
1773 // Emit initial Dwarf sections with a label at the start of each one.
1774 void DwarfDebug::emitSectionLabels() {
1775 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
1777 // Dwarf sections base addresses.
1778 DwarfInfoSectionSym =
1779 emitSectionSym(Asm, TLOF.getDwarfInfoSection(), "section_info");
1780 if (useSplitDwarf()) {
1781 DwarfInfoDWOSectionSym =
1782 emitSectionSym(Asm, TLOF.getDwarfInfoDWOSection(), "section_info_dwo");
1783 DwarfTypesDWOSectionSym =
1784 emitSectionSym(Asm, TLOF.getDwarfTypesDWOSection(), "section_types_dwo");
1786 DwarfAbbrevSectionSym =
1787 emitSectionSym(Asm, TLOF.getDwarfAbbrevSection(), "section_abbrev");
1788 if (useSplitDwarf())
1789 DwarfAbbrevDWOSectionSym = emitSectionSym(
1790 Asm, TLOF.getDwarfAbbrevDWOSection(), "section_abbrev_dwo");
1791 if (GenerateARangeSection)
1792 emitSectionSym(Asm, TLOF.getDwarfARangesSection());
1794 DwarfLineSectionSym =
1795 emitSectionSym(Asm, TLOF.getDwarfLineSection(), "section_line");
1796 if (GenerateGnuPubSections) {
1797 DwarfGnuPubNamesSectionSym =
1798 emitSectionSym(Asm, TLOF.getDwarfGnuPubNamesSection());
1799 DwarfGnuPubTypesSectionSym =
1800 emitSectionSym(Asm, TLOF.getDwarfGnuPubTypesSection());
1801 } else if (HasDwarfPubSections) {
1802 emitSectionSym(Asm, TLOF.getDwarfPubNamesSection());
1803 emitSectionSym(Asm, TLOF.getDwarfPubTypesSection());
1806 DwarfStrSectionSym =
1807 emitSectionSym(Asm, TLOF.getDwarfStrSection(), "info_string");
1808 if (useSplitDwarf()) {
1809 DwarfStrDWOSectionSym =
1810 emitSectionSym(Asm, TLOF.getDwarfStrDWOSection(), "skel_string");
1811 DwarfAddrSectionSym =
1812 emitSectionSym(Asm, TLOF.getDwarfAddrSection(), "addr_sec");
1813 DwarfDebugLocSectionSym =
1814 emitSectionSym(Asm, TLOF.getDwarfLocDWOSection(), "skel_loc");
1816 DwarfDebugLocSectionSym =
1817 emitSectionSym(Asm, TLOF.getDwarfLocSection(), "section_debug_loc");
1818 DwarfDebugRangeSectionSym =
1819 emitSectionSym(Asm, TLOF.getDwarfRangesSection(), "debug_range");
1822 // Recursively emits a debug information entry.
1823 void DwarfDebug::emitDIE(DIE &Die) {
1824 // Get the abbreviation for this DIE.
1825 const DIEAbbrev &Abbrev = Die.getAbbrev();
1827 // Emit the code (index) for the abbreviation.
1828 if (Asm->isVerbose())
1829 Asm->OutStreamer.AddComment("Abbrev [" + Twine(Abbrev.getNumber()) +
1830 "] 0x" + Twine::utohexstr(Die.getOffset()) +
1831 ":0x" + Twine::utohexstr(Die.getSize()) + " " +
1832 dwarf::TagString(Abbrev.getTag()));
1833 Asm->EmitULEB128(Abbrev.getNumber());
1835 const SmallVectorImpl<DIEValue *> &Values = Die.getValues();
1836 const SmallVectorImpl<DIEAbbrevData> &AbbrevData = Abbrev.getData();
1838 // Emit the DIE attribute values.
1839 for (unsigned i = 0, N = Values.size(); i < N; ++i) {
1840 dwarf::Attribute Attr = AbbrevData[i].getAttribute();
1841 dwarf::Form Form = AbbrevData[i].getForm();
1842 assert(Form && "Too many attributes for DIE (check abbreviation)");
1844 if (Asm->isVerbose()) {
1845 Asm->OutStreamer.AddComment(dwarf::AttributeString(Attr));
1846 if (Attr == dwarf::DW_AT_accessibility)
1847 Asm->OutStreamer.AddComment(dwarf::AccessibilityString(
1848 cast<DIEInteger>(Values[i])->getValue()));
1851 // Emit an attribute using the defined form.
1852 Values[i]->EmitValue(Asm, Form);
1855 // Emit the DIE children if any.
1856 if (Abbrev.hasChildren()) {
1857 for (auto &Child : Die.getChildren())
1860 Asm->OutStreamer.AddComment("End Of Children Mark");
1865 // Emit the debug info section.
1866 void DwarfDebug::emitDebugInfo() {
1867 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1869 Holder.emitUnits(this, DwarfAbbrevSectionSym);
1872 // Emit the abbreviation section.
1873 void DwarfDebug::emitAbbreviations() {
1874 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1876 Holder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevSection());
1879 // Emit the last address of the section and the end of the line matrix.
1880 void DwarfDebug::emitEndOfLineMatrix(unsigned SectionEnd) {
1881 // Define last address of section.
1882 Asm->OutStreamer.AddComment("Extended Op");
1885 Asm->OutStreamer.AddComment("Op size");
1886 Asm->EmitInt8(Asm->getDataLayout().getPointerSize() + 1);
1887 Asm->OutStreamer.AddComment("DW_LNE_set_address");
1888 Asm->EmitInt8(dwarf::DW_LNE_set_address);
1890 Asm->OutStreamer.AddComment("Section end label");
1892 Asm->OutStreamer.EmitSymbolValue(
1893 Asm->GetTempSymbol("section_end", SectionEnd),
1894 Asm->getDataLayout().getPointerSize());
1896 // Mark end of matrix.
1897 Asm->OutStreamer.AddComment("DW_LNE_end_sequence");
1903 void DwarfDebug::emitAccel(DwarfAccelTable &Accel, const MCSection *Section,
1904 StringRef TableName, StringRef SymName) {
1905 Accel.FinalizeTable(Asm, TableName);
1906 Asm->OutStreamer.SwitchSection(Section);
1907 auto *SectionBegin = Asm->GetTempSymbol(SymName);
1908 Asm->OutStreamer.EmitLabel(SectionBegin);
1910 // Emit the full data.
1911 Accel.Emit(Asm, SectionBegin, &InfoHolder, DwarfStrSectionSym);
1914 // Emit visible names into a hashed accelerator table section.
1915 void DwarfDebug::emitAccelNames() {
1916 emitAccel(AccelNames, Asm->getObjFileLowering().getDwarfAccelNamesSection(),
1917 "Names", "names_begin");
1920 // Emit objective C classes and categories into a hashed accelerator table
1922 void DwarfDebug::emitAccelObjC() {
1923 emitAccel(AccelObjC, Asm->getObjFileLowering().getDwarfAccelObjCSection(),
1924 "ObjC", "objc_begin");
1927 // Emit namespace dies into a hashed accelerator table.
1928 void DwarfDebug::emitAccelNamespaces() {
1929 emitAccel(AccelNamespace,
1930 Asm->getObjFileLowering().getDwarfAccelNamespaceSection(),
1931 "namespac", "namespac_begin");
1934 // Emit type dies into a hashed accelerator table.
1935 void DwarfDebug::emitAccelTypes() {
1936 emitAccel(AccelTypes, Asm->getObjFileLowering().getDwarfAccelTypesSection(),
1937 "types", "types_begin");
1940 // Public name handling.
1941 // The format for the various pubnames:
1943 // dwarf pubnames - offset/name pairs where the offset is the offset into the CU
1944 // for the DIE that is named.
1946 // gnu pubnames - offset/index value/name tuples where the offset is the offset
1947 // into the CU and the index value is computed according to the type of value
1948 // for the DIE that is named.
1950 // For type units the offset is the offset of the skeleton DIE. For split dwarf
1951 // it's the offset within the debug_info/debug_types dwo section, however, the
1952 // reference in the pubname header doesn't change.
1954 /// computeIndexValue - Compute the gdb index value for the DIE and CU.
1955 static dwarf::PubIndexEntryDescriptor computeIndexValue(DwarfUnit *CU,
1957 dwarf::GDBIndexEntryLinkage Linkage = dwarf::GIEL_STATIC;
1959 // We could have a specification DIE that has our most of our knowledge,
1960 // look for that now.
1961 DIEValue *SpecVal = Die->findAttribute(dwarf::DW_AT_specification);
1963 DIE &SpecDIE = cast<DIEEntry>(SpecVal)->getEntry();
1964 if (SpecDIE.findAttribute(dwarf::DW_AT_external))
1965 Linkage = dwarf::GIEL_EXTERNAL;
1966 } else if (Die->findAttribute(dwarf::DW_AT_external))
1967 Linkage = dwarf::GIEL_EXTERNAL;
1969 switch (Die->getTag()) {
1970 case dwarf::DW_TAG_class_type:
1971 case dwarf::DW_TAG_structure_type:
1972 case dwarf::DW_TAG_union_type:
1973 case dwarf::DW_TAG_enumeration_type:
1974 return dwarf::PubIndexEntryDescriptor(
1975 dwarf::GIEK_TYPE, CU->getLanguage() != dwarf::DW_LANG_C_plus_plus
1976 ? dwarf::GIEL_STATIC
1977 : dwarf::GIEL_EXTERNAL);
1978 case dwarf::DW_TAG_typedef:
1979 case dwarf::DW_TAG_base_type:
1980 case dwarf::DW_TAG_subrange_type:
1981 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_TYPE, dwarf::GIEL_STATIC);
1982 case dwarf::DW_TAG_namespace:
1983 return dwarf::GIEK_TYPE;
1984 case dwarf::DW_TAG_subprogram:
1985 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_FUNCTION, Linkage);
1986 case dwarf::DW_TAG_constant:
1987 case dwarf::DW_TAG_variable:
1988 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE, Linkage);
1989 case dwarf::DW_TAG_enumerator:
1990 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE,
1991 dwarf::GIEL_STATIC);
1993 return dwarf::GIEK_NONE;
1997 /// emitDebugPubNames - Emit visible names into a debug pubnames section.
1999 void DwarfDebug::emitDebugPubNames(bool GnuStyle) {
2000 const MCSection *PSec =
2001 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubNamesSection()
2002 : Asm->getObjFileLowering().getDwarfPubNamesSection();
2004 emitDebugPubSection(GnuStyle, PSec, "Names", &DwarfUnit::getGlobalNames);
2007 void DwarfDebug::emitDebugPubSection(
2008 bool GnuStyle, const MCSection *PSec, StringRef Name,
2009 const StringMap<const DIE *> &(DwarfUnit::*Accessor)() const) {
2010 for (const auto &NU : CUMap) {
2011 DwarfCompileUnit *TheU = NU.second;
2013 const auto &Globals = (TheU->*Accessor)();
2015 if (Globals.empty())
2018 if (auto Skeleton = static_cast<DwarfCompileUnit *>(TheU->getSkeleton()))
2020 unsigned ID = TheU->getUniqueID();
2022 // Start the dwarf pubnames section.
2023 Asm->OutStreamer.SwitchSection(PSec);
2026 Asm->OutStreamer.AddComment("Length of Public " + Name + " Info");
2027 MCSymbol *BeginLabel = Asm->GetTempSymbol("pub" + Name + "_begin", ID);
2028 MCSymbol *EndLabel = Asm->GetTempSymbol("pub" + Name + "_end", ID);
2029 Asm->EmitLabelDifference(EndLabel, BeginLabel, 4);
2031 Asm->OutStreamer.EmitLabel(BeginLabel);
2033 Asm->OutStreamer.AddComment("DWARF Version");
2034 Asm->EmitInt16(dwarf::DW_PUBNAMES_VERSION);
2036 Asm->OutStreamer.AddComment("Offset of Compilation Unit Info");
2037 Asm->EmitSectionOffset(TheU->getLabelBegin(), TheU->getSectionSym());
2039 Asm->OutStreamer.AddComment("Compilation Unit Length");
2040 Asm->EmitLabelDifference(TheU->getLabelEnd(), TheU->getLabelBegin(), 4);
2042 // Emit the pubnames for this compilation unit.
2043 for (const auto &GI : Globals) {
2044 const char *Name = GI.getKeyData();
2045 const DIE *Entity = GI.second;
2047 Asm->OutStreamer.AddComment("DIE offset");
2048 Asm->EmitInt32(Entity->getOffset());
2051 dwarf::PubIndexEntryDescriptor Desc = computeIndexValue(TheU, Entity);
2052 Asm->OutStreamer.AddComment(
2053 Twine("Kind: ") + dwarf::GDBIndexEntryKindString(Desc.Kind) + ", " +
2054 dwarf::GDBIndexEntryLinkageString(Desc.Linkage));
2055 Asm->EmitInt8(Desc.toBits());
2058 Asm->OutStreamer.AddComment("External Name");
2059 Asm->OutStreamer.EmitBytes(StringRef(Name, GI.getKeyLength() + 1));
2062 Asm->OutStreamer.AddComment("End Mark");
2064 Asm->OutStreamer.EmitLabel(EndLabel);
2068 void DwarfDebug::emitDebugPubTypes(bool GnuStyle) {
2069 const MCSection *PSec =
2070 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubTypesSection()
2071 : Asm->getObjFileLowering().getDwarfPubTypesSection();
2073 emitDebugPubSection(GnuStyle, PSec, "Types", &DwarfUnit::getGlobalTypes);
2076 // Emit visible names into a debug str section.
2077 void DwarfDebug::emitDebugStr() {
2078 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
2079 Holder.emitStrings(Asm->getObjFileLowering().getDwarfStrSection());
2082 /// Emits an optimal (=sorted) sequence of DW_OP_pieces.
2083 void DwarfDebug::emitLocPieces(ByteStreamer &Streamer,
2084 const DITypeIdentifierMap &Map,
2085 ArrayRef<DebugLocEntry::Value> Values) {
2086 assert(std::all_of(Values.begin(), Values.end(), [](DebugLocEntry::Value P) {
2087 return P.isVariablePiece();
2088 }) && "all values are expected to be pieces");
2089 assert(std::is_sorted(Values.begin(), Values.end()) &&
2090 "pieces are expected to be sorted");
2092 unsigned Offset = 0;
2093 for (auto Piece : Values) {
2094 DIVariable Var = Piece.getVariable();
2095 unsigned PieceOffset = Var.getPieceOffset();
2096 unsigned PieceSize = Var.getPieceSize();
2097 assert(Offset <= PieceOffset && "overlapping or duplicate pieces");
2098 if (Offset < PieceOffset) {
2099 // The DWARF spec seriously mandates pieces with no locations for gaps.
2100 Asm->EmitDwarfOpPiece(Streamer, (PieceOffset-Offset)*8);
2101 Offset += PieceOffset-Offset;
2104 Offset += PieceSize;
2106 const unsigned SizeOfByte = 8;
2107 assert(!Var.isIndirect() && "indirect address for piece");
2109 unsigned VarSize = Var.getSizeInBits(Map);
2110 assert(PieceSize+PieceOffset <= VarSize/SizeOfByte
2111 && "piece is larger than or outside of variable");
2112 assert(PieceSize*SizeOfByte != VarSize
2113 && "piece covers entire variable");
2115 if (Piece.isLocation() && Piece.getLoc().isReg())
2116 Asm->EmitDwarfRegOpPiece(Streamer,
2118 PieceSize*SizeOfByte);
2120 emitDebugLocValue(Streamer, Piece);
2121 Asm->EmitDwarfOpPiece(Streamer, PieceSize*SizeOfByte);
2127 void DwarfDebug::emitDebugLocEntry(ByteStreamer &Streamer,
2128 const DebugLocEntry &Entry) {
2129 const DebugLocEntry::Value Value = Entry.getValues()[0];
2130 if (Value.isVariablePiece())
2131 // Emit all pieces that belong to the same variable and range.
2132 return emitLocPieces(Streamer, TypeIdentifierMap, Entry.getValues());
2134 assert(Entry.getValues().size() == 1 && "only pieces may have >1 value");
2135 emitDebugLocValue(Streamer, Value);
2138 void DwarfDebug::emitDebugLocValue(ByteStreamer &Streamer,
2139 const DebugLocEntry::Value &Value) {
2140 DIVariable DV = Value.getVariable();
2142 if (Value.isInt()) {
2143 DIBasicType BTy(resolve(DV.getType()));
2144 if (BTy.Verify() && (BTy.getEncoding() == dwarf::DW_ATE_signed ||
2145 BTy.getEncoding() == dwarf::DW_ATE_signed_char)) {
2146 Streamer.EmitInt8(dwarf::DW_OP_consts, "DW_OP_consts");
2147 Streamer.EmitSLEB128(Value.getInt());
2149 Streamer.EmitInt8(dwarf::DW_OP_constu, "DW_OP_constu");
2150 Streamer.EmitULEB128(Value.getInt());
2152 } else if (Value.isLocation()) {
2153 MachineLocation Loc = Value.getLoc();
2154 if (!DV.hasComplexAddress())
2156 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2158 // Complex address entry.
2159 unsigned N = DV.getNumAddrElements();
2161 if (N >= 2 && DV.getAddrElement(0) == DIBuilder::OpPlus) {
2162 if (Loc.getOffset()) {
2164 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2165 Streamer.EmitInt8(dwarf::DW_OP_deref, "DW_OP_deref");
2166 Streamer.EmitInt8(dwarf::DW_OP_plus_uconst, "DW_OP_plus_uconst");
2167 Streamer.EmitSLEB128(DV.getAddrElement(1));
2169 // If first address element is OpPlus then emit
2170 // DW_OP_breg + Offset instead of DW_OP_reg + Offset.
2171 MachineLocation TLoc(Loc.getReg(), DV.getAddrElement(1));
2172 Asm->EmitDwarfRegOp(Streamer, TLoc, DV.isIndirect());
2176 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2179 // Emit remaining complex address elements.
2180 for (; i < N; ++i) {
2181 uint64_t Element = DV.getAddrElement(i);
2182 if (Element == DIBuilder::OpPlus) {
2183 Streamer.EmitInt8(dwarf::DW_OP_plus_uconst, "DW_OP_plus_uconst");
2184 Streamer.EmitULEB128(DV.getAddrElement(++i));
2185 } else if (Element == DIBuilder::OpDeref) {
2187 Streamer.EmitInt8(dwarf::DW_OP_deref, "DW_OP_deref");
2188 } else if (Element == DIBuilder::OpPiece) {
2190 // handled in emitDebugLocEntry.
2192 llvm_unreachable("unknown Opcode found in complex address");
2196 // else ... ignore constant fp. There is not any good way to
2197 // to represent them here in dwarf.
2201 void DwarfDebug::emitDebugLocEntryLocation(const DebugLocEntry &Entry) {
2202 Asm->OutStreamer.AddComment("Loc expr size");
2203 MCSymbol *begin = Asm->OutStreamer.getContext().CreateTempSymbol();
2204 MCSymbol *end = Asm->OutStreamer.getContext().CreateTempSymbol();
2205 Asm->EmitLabelDifference(end, begin, 2);
2206 Asm->OutStreamer.EmitLabel(begin);
2208 APByteStreamer Streamer(*Asm);
2209 emitDebugLocEntry(Streamer, Entry);
2211 Asm->OutStreamer.EmitLabel(end);
2214 // Emit locations into the debug loc section.
2215 void DwarfDebug::emitDebugLoc() {
2216 // Start the dwarf loc section.
2217 Asm->OutStreamer.SwitchSection(
2218 Asm->getObjFileLowering().getDwarfLocSection());
2219 unsigned char Size = Asm->getDataLayout().getPointerSize();
2220 for (const auto &DebugLoc : DotDebugLocEntries) {
2221 Asm->OutStreamer.EmitLabel(DebugLoc.Label);
2222 const DwarfCompileUnit *CU = DebugLoc.CU;
2223 assert(!CU->getRanges().empty());
2224 for (const auto &Entry : DebugLoc.List) {
2225 // Set up the range. This range is relative to the entry point of the
2226 // compile unit. This is a hard coded 0 for low_pc when we're emitting
2227 // ranges, or the DW_AT_low_pc on the compile unit otherwise.
2228 if (CU->getRanges().size() == 1) {
2229 // Grab the begin symbol from the first range as our base.
2230 const MCSymbol *Base = CU->getRanges()[0].getStart();
2231 Asm->EmitLabelDifference(Entry.getBeginSym(), Base, Size);
2232 Asm->EmitLabelDifference(Entry.getEndSym(), Base, Size);
2234 Asm->OutStreamer.EmitSymbolValue(Entry.getBeginSym(), Size);
2235 Asm->OutStreamer.EmitSymbolValue(Entry.getEndSym(), Size);
2238 emitDebugLocEntryLocation(Entry);
2240 Asm->OutStreamer.EmitIntValue(0, Size);
2241 Asm->OutStreamer.EmitIntValue(0, Size);
2245 void DwarfDebug::emitDebugLocDWO() {
2246 Asm->OutStreamer.SwitchSection(
2247 Asm->getObjFileLowering().getDwarfLocDWOSection());
2248 for (const auto &DebugLoc : DotDebugLocEntries) {
2249 Asm->OutStreamer.EmitLabel(DebugLoc.Label);
2250 for (const auto &Entry : DebugLoc.List) {
2251 // Just always use start_length for now - at least that's one address
2252 // rather than two. We could get fancier and try to, say, reuse an
2253 // address we know we've emitted elsewhere (the start of the function?
2254 // The start of the CU or CU subrange that encloses this range?)
2255 Asm->EmitInt8(dwarf::DW_LLE_start_length_entry);
2256 unsigned idx = AddrPool.getIndex(Entry.getBeginSym());
2257 Asm->EmitULEB128(idx);
2258 Asm->EmitLabelDifference(Entry.getEndSym(), Entry.getBeginSym(), 4);
2260 emitDebugLocEntryLocation(Entry);
2262 Asm->EmitInt8(dwarf::DW_LLE_end_of_list_entry);
2267 const MCSymbol *Start, *End;
2270 // Emit a debug aranges section, containing a CU lookup for any
2271 // address we can tie back to a CU.
2272 void DwarfDebug::emitDebugARanges() {
2273 // Start the dwarf aranges section.
2274 Asm->OutStreamer.SwitchSection(
2275 Asm->getObjFileLowering().getDwarfARangesSection());
2277 typedef DenseMap<DwarfCompileUnit *, std::vector<ArangeSpan>> SpansType;
2281 // Build a list of sections used.
2282 std::vector<const MCSection *> Sections;
2283 for (const auto &it : SectionMap) {
2284 const MCSection *Section = it.first;
2285 Sections.push_back(Section);
2288 // Sort the sections into order.
2289 // This is only done to ensure consistent output order across different runs.
2290 std::sort(Sections.begin(), Sections.end(), SectionSort);
2292 // Build a set of address spans, sorted by CU.
2293 for (const MCSection *Section : Sections) {
2294 SmallVector<SymbolCU, 8> &List = SectionMap[Section];
2295 if (List.size() < 2)
2298 // Sort the symbols by offset within the section.
2299 std::sort(List.begin(), List.end(),
2300 [&](const SymbolCU &A, const SymbolCU &B) {
2301 unsigned IA = A.Sym ? Asm->OutStreamer.GetSymbolOrder(A.Sym) : 0;
2302 unsigned IB = B.Sym ? Asm->OutStreamer.GetSymbolOrder(B.Sym) : 0;
2304 // Symbols with no order assigned should be placed at the end.
2305 // (e.g. section end labels)
2313 // If we have no section (e.g. common), just write out
2314 // individual spans for each symbol.
2316 for (const SymbolCU &Cur : List) {
2318 Span.Start = Cur.Sym;
2321 Spans[Cur.CU].push_back(Span);
2324 // Build spans between each label.
2325 const MCSymbol *StartSym = List[0].Sym;
2326 for (size_t n = 1, e = List.size(); n < e; n++) {
2327 const SymbolCU &Prev = List[n - 1];
2328 const SymbolCU &Cur = List[n];
2330 // Try and build the longest span we can within the same CU.
2331 if (Cur.CU != Prev.CU) {
2333 Span.Start = StartSym;
2335 Spans[Prev.CU].push_back(Span);
2342 unsigned PtrSize = Asm->getDataLayout().getPointerSize();
2344 // Build a list of CUs used.
2345 std::vector<DwarfCompileUnit *> CUs;
2346 for (const auto &it : Spans) {
2347 DwarfCompileUnit *CU = it.first;
2351 // Sort the CU list (again, to ensure consistent output order).
2352 std::sort(CUs.begin(), CUs.end(), [](const DwarfUnit *A, const DwarfUnit *B) {
2353 return A->getUniqueID() < B->getUniqueID();
2356 // Emit an arange table for each CU we used.
2357 for (DwarfCompileUnit *CU : CUs) {
2358 std::vector<ArangeSpan> &List = Spans[CU];
2360 // Emit size of content not including length itself.
2361 unsigned ContentSize =
2362 sizeof(int16_t) + // DWARF ARange version number
2363 sizeof(int32_t) + // Offset of CU in the .debug_info section
2364 sizeof(int8_t) + // Pointer Size (in bytes)
2365 sizeof(int8_t); // Segment Size (in bytes)
2367 unsigned TupleSize = PtrSize * 2;
2369 // 7.20 in the Dwarf specs requires the table to be aligned to a tuple.
2371 OffsetToAlignment(sizeof(int32_t) + ContentSize, TupleSize);
2373 ContentSize += Padding;
2374 ContentSize += (List.size() + 1) * TupleSize;
2376 // For each compile unit, write the list of spans it covers.
2377 Asm->OutStreamer.AddComment("Length of ARange Set");
2378 Asm->EmitInt32(ContentSize);
2379 Asm->OutStreamer.AddComment("DWARF Arange version number");
2380 Asm->EmitInt16(dwarf::DW_ARANGES_VERSION);
2381 Asm->OutStreamer.AddComment("Offset Into Debug Info Section");
2382 Asm->EmitSectionOffset(CU->getLocalLabelBegin(), CU->getLocalSectionSym());
2383 Asm->OutStreamer.AddComment("Address Size (in bytes)");
2384 Asm->EmitInt8(PtrSize);
2385 Asm->OutStreamer.AddComment("Segment Size (in bytes)");
2388 Asm->OutStreamer.EmitFill(Padding, 0xff);
2390 for (const ArangeSpan &Span : List) {
2391 Asm->EmitLabelReference(Span.Start, PtrSize);
2393 // Calculate the size as being from the span start to it's end.
2395 Asm->EmitLabelDifference(Span.End, Span.Start, PtrSize);
2397 // For symbols without an end marker (e.g. common), we
2398 // write a single arange entry containing just that one symbol.
2399 uint64_t Size = SymSize[Span.Start];
2403 Asm->OutStreamer.EmitIntValue(Size, PtrSize);
2407 Asm->OutStreamer.AddComment("ARange terminator");
2408 Asm->OutStreamer.EmitIntValue(0, PtrSize);
2409 Asm->OutStreamer.EmitIntValue(0, PtrSize);
2413 // Emit visible names into a debug ranges section.
2414 void DwarfDebug::emitDebugRanges() {
2415 // Start the dwarf ranges section.
2416 Asm->OutStreamer.SwitchSection(
2417 Asm->getObjFileLowering().getDwarfRangesSection());
2419 // Size for our labels.
2420 unsigned char Size = Asm->getDataLayout().getPointerSize();
2422 // Grab the specific ranges for the compile units in the module.
2423 for (const auto &I : CUMap) {
2424 DwarfCompileUnit *TheCU = I.second;
2426 // Iterate over the misc ranges for the compile units in the module.
2427 for (const RangeSpanList &List : TheCU->getRangeLists()) {
2428 // Emit our symbol so we can find the beginning of the range.
2429 Asm->OutStreamer.EmitLabel(List.getSym());
2431 for (const RangeSpan &Range : List.getRanges()) {
2432 const MCSymbol *Begin = Range.getStart();
2433 const MCSymbol *End = Range.getEnd();
2434 assert(Begin && "Range without a begin symbol?");
2435 assert(End && "Range without an end symbol?");
2436 if (TheCU->getRanges().size() == 1) {
2437 // Grab the begin symbol from the first range as our base.
2438 const MCSymbol *Base = TheCU->getRanges()[0].getStart();
2439 Asm->EmitLabelDifference(Begin, Base, Size);
2440 Asm->EmitLabelDifference(End, Base, Size);
2442 Asm->OutStreamer.EmitSymbolValue(Begin, Size);
2443 Asm->OutStreamer.EmitSymbolValue(End, Size);
2447 // And terminate the list with two 0 values.
2448 Asm->OutStreamer.EmitIntValue(0, Size);
2449 Asm->OutStreamer.EmitIntValue(0, Size);
2452 // Now emit a range for the CU itself.
2453 if (TheCU->getRanges().size() > 1) {
2454 Asm->OutStreamer.EmitLabel(
2455 Asm->GetTempSymbol("cu_ranges", TheCU->getUniqueID()));
2456 for (const RangeSpan &Range : TheCU->getRanges()) {
2457 const MCSymbol *Begin = Range.getStart();
2458 const MCSymbol *End = Range.getEnd();
2459 assert(Begin && "Range without a begin symbol?");
2460 assert(End && "Range without an end symbol?");
2461 Asm->OutStreamer.EmitSymbolValue(Begin, Size);
2462 Asm->OutStreamer.EmitSymbolValue(End, Size);
2464 // And terminate the list with two 0 values.
2465 Asm->OutStreamer.EmitIntValue(0, Size);
2466 Asm->OutStreamer.EmitIntValue(0, Size);
2471 // DWARF5 Experimental Separate Dwarf emitters.
2473 void DwarfDebug::initSkeletonUnit(const DwarfUnit &U, DIE &Die,
2474 std::unique_ptr<DwarfUnit> NewU) {
2475 NewU->addLocalString(Die, dwarf::DW_AT_GNU_dwo_name,
2476 U.getCUNode().getSplitDebugFilename());
2478 if (!CompilationDir.empty())
2479 NewU->addLocalString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
2481 addGnuPubAttributes(*NewU, Die);
2483 SkeletonHolder.addUnit(std::move(NewU));
2486 // This DIE has the following attributes: DW_AT_comp_dir, DW_AT_stmt_list,
2487 // DW_AT_low_pc, DW_AT_high_pc, DW_AT_ranges, DW_AT_dwo_name, DW_AT_dwo_id,
2488 // DW_AT_addr_base, DW_AT_ranges_base.
2489 DwarfCompileUnit &DwarfDebug::constructSkeletonCU(const DwarfCompileUnit &CU) {
2491 auto OwnedUnit = make_unique<DwarfCompileUnit>(
2492 CU.getUniqueID(), CU.getCUNode(), Asm, this, &SkeletonHolder);
2493 DwarfCompileUnit &NewCU = *OwnedUnit;
2494 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoSection(),
2495 DwarfInfoSectionSym);
2497 NewCU.initStmtList(DwarfLineSectionSym);
2499 initSkeletonUnit(CU, NewCU.getUnitDie(), std::move(OwnedUnit));
2504 // Emit the .debug_info.dwo section for separated dwarf. This contains the
2505 // compile units that would normally be in debug_info.
2506 void DwarfDebug::emitDebugInfoDWO() {
2507 assert(useSplitDwarf() && "No split dwarf debug info?");
2508 // Don't pass an abbrev symbol, using a constant zero instead so as not to
2509 // emit relocations into the dwo file.
2510 InfoHolder.emitUnits(this, /* AbbrevSymbol */ nullptr);
2513 // Emit the .debug_abbrev.dwo section for separated dwarf. This contains the
2514 // abbreviations for the .debug_info.dwo section.
2515 void DwarfDebug::emitDebugAbbrevDWO() {
2516 assert(useSplitDwarf() && "No split dwarf?");
2517 InfoHolder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevDWOSection());
2520 void DwarfDebug::emitDebugLineDWO() {
2521 assert(useSplitDwarf() && "No split dwarf?");
2522 Asm->OutStreamer.SwitchSection(
2523 Asm->getObjFileLowering().getDwarfLineDWOSection());
2524 SplitTypeUnitFileTable.Emit(Asm->OutStreamer);
2527 // Emit the .debug_str.dwo section for separated dwarf. This contains the
2528 // string section and is identical in format to traditional .debug_str
2530 void DwarfDebug::emitDebugStrDWO() {
2531 assert(useSplitDwarf() && "No split dwarf?");
2532 const MCSection *OffSec =
2533 Asm->getObjFileLowering().getDwarfStrOffDWOSection();
2534 InfoHolder.emitStrings(Asm->getObjFileLowering().getDwarfStrDWOSection(),
2538 MCDwarfDwoLineTable *DwarfDebug::getDwoLineTable(const DwarfCompileUnit &CU) {
2539 if (!useSplitDwarf())
2542 SplitTypeUnitFileTable.setCompilationDir(CU.getCUNode().getDirectory());
2543 return &SplitTypeUnitFileTable;
2546 static uint64_t makeTypeSignature(StringRef Identifier) {
2548 Hash.update(Identifier);
2549 // ... take the least significant 8 bytes and return those. Our MD5
2550 // implementation always returns its results in little endian, swap bytes
2552 MD5::MD5Result Result;
2554 return *reinterpret_cast<support::ulittle64_t *>(Result + 8);
2557 void DwarfDebug::addDwarfTypeUnitType(DwarfCompileUnit &CU,
2558 StringRef Identifier, DIE &RefDie,
2559 DICompositeType CTy) {
2560 // Fast path if we're building some type units and one has already used the
2561 // address pool we know we're going to throw away all this work anyway, so
2562 // don't bother building dependent types.
2563 if (!TypeUnitsUnderConstruction.empty() && AddrPool.hasBeenUsed())
2566 const DwarfTypeUnit *&TU = DwarfTypeUnits[CTy];
2568 CU.addDIETypeSignature(RefDie, *TU);
2572 bool TopLevelType = TypeUnitsUnderConstruction.empty();
2573 AddrPool.resetUsedFlag();
2575 auto OwnedUnit = make_unique<DwarfTypeUnit>(
2576 InfoHolder.getUnits().size() + TypeUnitsUnderConstruction.size(), CU, Asm,
2577 this, &InfoHolder, getDwoLineTable(CU));
2578 DwarfTypeUnit &NewTU = *OwnedUnit;
2579 DIE &UnitDie = NewTU.getUnitDie();
2581 TypeUnitsUnderConstruction.push_back(
2582 std::make_pair(std::move(OwnedUnit), CTy));
2584 NewTU.addUInt(UnitDie, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
2587 uint64_t Signature = makeTypeSignature(Identifier);
2588 NewTU.setTypeSignature(Signature);
2590 if (useSplitDwarf())
2591 NewTU.initSection(Asm->getObjFileLowering().getDwarfTypesDWOSection(),
2592 DwarfTypesDWOSectionSym);
2594 CU.applyStmtList(UnitDie);
2596 Asm->getObjFileLowering().getDwarfTypesSection(Signature));
2599 NewTU.setType(NewTU.createTypeDIE(CTy));
2602 auto TypeUnitsToAdd = std::move(TypeUnitsUnderConstruction);
2603 TypeUnitsUnderConstruction.clear();
2605 // Types referencing entries in the address table cannot be placed in type
2607 if (AddrPool.hasBeenUsed()) {
2609 // Remove all the types built while building this type.
2610 // This is pessimistic as some of these types might not be dependent on
2611 // the type that used an address.
2612 for (const auto &TU : TypeUnitsToAdd)
2613 DwarfTypeUnits.erase(TU.second);
2615 // Construct this type in the CU directly.
2616 // This is inefficient because all the dependent types will be rebuilt
2617 // from scratch, including building them in type units, discovering that
2618 // they depend on addresses, throwing them out and rebuilding them.
2619 CU.constructTypeDIE(RefDie, CTy);
2623 // If the type wasn't dependent on fission addresses, finish adding the type
2624 // and all its dependent types.
2625 for (auto &TU : TypeUnitsToAdd)
2626 InfoHolder.addUnit(std::move(TU.first));
2628 CU.addDIETypeSignature(RefDie, NewTU);
2631 void DwarfDebug::attachLowHighPC(DwarfCompileUnit &Unit, DIE &D,
2632 const MCSymbol *Begin, const MCSymbol *End) {
2633 assert(Begin && "Begin label should not be null!");
2634 assert(End && "End label should not be null!");
2635 assert(Begin->isDefined() && "Invalid starting label");
2636 assert(End->isDefined() && "Invalid end label");
2638 Unit.addLabelAddress(D, dwarf::DW_AT_low_pc, Begin);
2639 if (DwarfVersion < 4)
2640 Unit.addLabelAddress(D, dwarf::DW_AT_high_pc, End);
2642 Unit.addLabelDelta(D, dwarf::DW_AT_high_pc, End, Begin);
2645 // Accelerator table mutators - add each name along with its companion
2646 // DIE to the proper table while ensuring that the name that we're going
2647 // to reference is in the string table. We do this since the names we
2648 // add may not only be identical to the names in the DIE.
2649 void DwarfDebug::addAccelName(StringRef Name, const DIE &Die) {
2650 if (!useDwarfAccelTables())
2652 AccelNames.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2656 void DwarfDebug::addAccelObjC(StringRef Name, const DIE &Die) {
2657 if (!useDwarfAccelTables())
2659 AccelObjC.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2663 void DwarfDebug::addAccelNamespace(StringRef Name, const DIE &Die) {
2664 if (!useDwarfAccelTables())
2666 AccelNamespace.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2670 void DwarfDebug::addAccelType(StringRef Name, const DIE &Die, char Flags) {
2671 if (!useDwarfAccelTables())
2673 AccelTypes.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),