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 "DwarfDebug.h"
16 #include "ByteStreamer.h"
17 #include "DwarfCompileUnit.h"
20 #include "DwarfUnit.h"
21 #include "llvm/ADT/STLExtras.h"
22 #include "llvm/ADT/Statistic.h"
23 #include "llvm/ADT/StringExtras.h"
24 #include "llvm/ADT/Triple.h"
25 #include "llvm/CodeGen/MachineFunction.h"
26 #include "llvm/CodeGen/MachineModuleInfo.h"
27 #include "llvm/IR/Constants.h"
28 #include "llvm/IR/DIBuilder.h"
29 #include "llvm/IR/DataLayout.h"
30 #include "llvm/IR/DebugInfo.h"
31 #include "llvm/IR/Instructions.h"
32 #include "llvm/IR/Module.h"
33 #include "llvm/IR/ValueHandle.h"
34 #include "llvm/MC/MCAsmInfo.h"
35 #include "llvm/MC/MCSection.h"
36 #include "llvm/MC/MCStreamer.h"
37 #include "llvm/MC/MCSymbol.h"
38 #include "llvm/Support/CommandLine.h"
39 #include "llvm/Support/Debug.h"
40 #include "llvm/Support/Dwarf.h"
41 #include "llvm/Support/Endian.h"
42 #include "llvm/Support/ErrorHandling.h"
43 #include "llvm/Support/FormattedStream.h"
44 #include "llvm/Support/LEB128.h"
45 #include "llvm/Support/MD5.h"
46 #include "llvm/Support/Path.h"
47 #include "llvm/Support/Timer.h"
48 #include "llvm/Target/TargetFrameLowering.h"
49 #include "llvm/Target/TargetLoweringObjectFile.h"
50 #include "llvm/Target/TargetMachine.h"
51 #include "llvm/Target/TargetOptions.h"
52 #include "llvm/Target/TargetRegisterInfo.h"
53 #include "llvm/Target/TargetSubtargetInfo.h"
56 #define DEBUG_TYPE "dwarfdebug"
59 DisableDebugInfoPrinting("disable-debug-info-print", cl::Hidden,
60 cl::desc("Disable debug info printing"));
62 static cl::opt<bool> UnknownLocations(
63 "use-unknown-locations", cl::Hidden,
64 cl::desc("Make an absence of debug location information explicit."),
68 GenerateGnuPubSections("generate-gnu-dwarf-pub-sections", cl::Hidden,
69 cl::desc("Generate GNU-style pubnames and pubtypes"),
72 static cl::opt<bool> GenerateARangeSection("generate-arange-section",
74 cl::desc("Generate dwarf aranges"),
78 enum DefaultOnOff { Default, Enable, Disable };
81 static cl::opt<DefaultOnOff>
82 DwarfAccelTables("dwarf-accel-tables", cl::Hidden,
83 cl::desc("Output prototype dwarf accelerator tables."),
84 cl::values(clEnumVal(Default, "Default for platform"),
85 clEnumVal(Enable, "Enabled"),
86 clEnumVal(Disable, "Disabled"), clEnumValEnd),
89 static cl::opt<DefaultOnOff>
90 SplitDwarf("split-dwarf", cl::Hidden,
91 cl::desc("Output DWARF5 split debug info."),
92 cl::values(clEnumVal(Default, "Default for platform"),
93 clEnumVal(Enable, "Enabled"),
94 clEnumVal(Disable, "Disabled"), clEnumValEnd),
97 static cl::opt<DefaultOnOff>
98 DwarfPubSections("generate-dwarf-pub-sections", cl::Hidden,
99 cl::desc("Generate DWARF pubnames and pubtypes sections"),
100 cl::values(clEnumVal(Default, "Default for platform"),
101 clEnumVal(Enable, "Enabled"),
102 clEnumVal(Disable, "Disabled"), clEnumValEnd),
105 static const char *const DWARFGroupName = "DWARF Emission";
106 static const char *const DbgTimerName = "DWARF Debug Writer";
108 //===----------------------------------------------------------------------===//
110 /// resolve - Look in the DwarfDebug map for the MDNode that
111 /// corresponds to the reference.
112 template <typename T> T DbgVariable::resolve(DIRef<T> Ref) const {
113 return DD->resolve(Ref);
116 bool DbgVariable::isBlockByrefVariable() const {
117 assert(Var.isVariable() && "Invalid complex DbgVariable!");
118 return Var.isBlockByrefVariable(DD->getTypeIdentifierMap());
121 DIType DbgVariable::getType() const {
122 DIType Ty = Var.getType().resolve(DD->getTypeIdentifierMap());
123 // FIXME: isBlockByrefVariable should be reformulated in terms of complex
124 // addresses instead.
125 if (Var.isBlockByrefVariable(DD->getTypeIdentifierMap())) {
126 /* Byref variables, in Blocks, are declared by the programmer as
127 "SomeType VarName;", but the compiler creates a
128 __Block_byref_x_VarName struct, and gives the variable VarName
129 either the struct, or a pointer to the struct, as its type. This
130 is necessary for various behind-the-scenes things the compiler
131 needs to do with by-reference variables in blocks.
133 However, as far as the original *programmer* is concerned, the
134 variable should still have type 'SomeType', as originally declared.
136 The following function dives into the __Block_byref_x_VarName
137 struct to find the original type of the variable. This will be
138 passed back to the code generating the type for the Debug
139 Information Entry for the variable 'VarName'. 'VarName' will then
140 have the original type 'SomeType' in its debug information.
142 The original type 'SomeType' will be the type of the field named
143 'VarName' inside the __Block_byref_x_VarName struct.
145 NOTE: In order for this to not completely fail on the debugger
146 side, the Debug Information Entry for the variable VarName needs to
147 have a DW_AT_location that tells the debugger how to unwind through
148 the pointers and __Block_byref_x_VarName struct to find the actual
149 value of the variable. The function addBlockByrefType does this. */
151 uint16_t tag = Ty.getTag();
153 if (tag == dwarf::DW_TAG_pointer_type)
154 subType = resolve(DIDerivedType(Ty).getTypeDerivedFrom());
156 DIArray Elements = DICompositeType(subType).getElements();
157 for (unsigned i = 0, N = Elements.getNumElements(); i < N; ++i) {
158 DIDerivedType DT(Elements.getElement(i));
159 if (getName() == DT.getName())
160 return (resolve(DT.getTypeDerivedFrom()));
166 static LLVM_CONSTEXPR DwarfAccelTable::Atom TypeAtoms[] = {
167 DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset, dwarf::DW_FORM_data4),
168 DwarfAccelTable::Atom(dwarf::DW_ATOM_die_tag, dwarf::DW_FORM_data2),
169 DwarfAccelTable::Atom(dwarf::DW_ATOM_type_flags, dwarf::DW_FORM_data1)};
171 DwarfDebug::DwarfDebug(AsmPrinter *A, Module *M)
172 : Asm(A), MMI(Asm->MMI), FirstCU(nullptr), PrevLabel(nullptr),
173 GlobalRangeCount(0), InfoHolder(A, "info_string", DIEValueAllocator),
174 UsedNonDefaultText(false),
175 SkeletonHolder(A, "skel_string", DIEValueAllocator),
176 IsDarwin(Triple(A->getTargetTriple()).isOSDarwin()),
177 AccelNames(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
178 dwarf::DW_FORM_data4)),
179 AccelObjC(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
180 dwarf::DW_FORM_data4)),
181 AccelNamespace(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
182 dwarf::DW_FORM_data4)),
183 AccelTypes(TypeAtoms) {
185 DwarfInfoSectionSym = DwarfAbbrevSectionSym = DwarfStrSectionSym = nullptr;
186 DwarfDebugRangeSectionSym = DwarfDebugLocSectionSym = nullptr;
187 DwarfLineSectionSym = nullptr;
188 DwarfAddrSectionSym = nullptr;
189 DwarfAbbrevDWOSectionSym = DwarfStrDWOSectionSym = nullptr;
190 FunctionBeginSym = FunctionEndSym = nullptr;
194 // Turn on accelerator tables for Darwin by default, pubnames by
195 // default for non-Darwin, and handle split dwarf.
196 if (DwarfAccelTables == Default)
197 HasDwarfAccelTables = IsDarwin;
199 HasDwarfAccelTables = DwarfAccelTables == Enable;
201 if (SplitDwarf == Default)
202 HasSplitDwarf = false;
204 HasSplitDwarf = SplitDwarf == Enable;
206 if (DwarfPubSections == Default)
207 HasDwarfPubSections = !IsDarwin;
209 HasDwarfPubSections = DwarfPubSections == Enable;
211 unsigned DwarfVersionNumber = Asm->TM.Options.MCOptions.DwarfVersion;
212 DwarfVersion = DwarfVersionNumber ? DwarfVersionNumber
213 : MMI->getModule()->getDwarfVersion();
215 Asm->OutStreamer.getContext().setDwarfVersion(DwarfVersion);
218 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
223 // Define out of line so we don't have to include DwarfUnit.h in DwarfDebug.h.
224 DwarfDebug::~DwarfDebug() { }
226 // Switch to the specified MCSection and emit an assembler
227 // temporary label to it if SymbolStem is specified.
228 static MCSymbol *emitSectionSym(AsmPrinter *Asm, const MCSection *Section,
229 const char *SymbolStem = nullptr) {
230 Asm->OutStreamer.SwitchSection(Section);
234 MCSymbol *TmpSym = Asm->GetTempSymbol(SymbolStem);
235 Asm->OutStreamer.EmitLabel(TmpSym);
239 static bool isObjCClass(StringRef Name) {
240 return Name.startswith("+") || Name.startswith("-");
243 static bool hasObjCCategory(StringRef Name) {
244 if (!isObjCClass(Name))
247 return Name.find(") ") != StringRef::npos;
250 static void getObjCClassCategory(StringRef In, StringRef &Class,
251 StringRef &Category) {
252 if (!hasObjCCategory(In)) {
253 Class = In.slice(In.find('[') + 1, In.find(' '));
258 Class = In.slice(In.find('[') + 1, In.find('('));
259 Category = In.slice(In.find('[') + 1, In.find(' '));
263 static StringRef getObjCMethodName(StringRef In) {
264 return In.slice(In.find(' ') + 1, In.find(']'));
267 // Helper for sorting sections into a stable output order.
268 static bool SectionSort(const MCSection *A, const MCSection *B) {
269 std::string LA = (A ? A->getLabelBeginName() : "");
270 std::string LB = (B ? B->getLabelBeginName() : "");
274 // Add the various names to the Dwarf accelerator table names.
275 // TODO: Determine whether or not we should add names for programs
276 // that do not have a DW_AT_name or DW_AT_linkage_name field - this
277 // is only slightly different than the lookup of non-standard ObjC names.
278 void DwarfDebug::addSubprogramNames(DISubprogram SP, DIE &Die) {
279 if (!SP.isDefinition())
281 addAccelName(SP.getName(), Die);
283 // If the linkage name is different than the name, go ahead and output
284 // that as well into the name table.
285 if (SP.getLinkageName() != "" && SP.getName() != SP.getLinkageName())
286 addAccelName(SP.getLinkageName(), Die);
288 // If this is an Objective-C selector name add it to the ObjC accelerator
290 if (isObjCClass(SP.getName())) {
291 StringRef Class, Category;
292 getObjCClassCategory(SP.getName(), Class, Category);
293 addAccelObjC(Class, Die);
295 addAccelObjC(Category, Die);
296 // Also add the base method name to the name table.
297 addAccelName(getObjCMethodName(SP.getName()), Die);
301 /// isSubprogramContext - Return true if Context is either a subprogram
302 /// or another context nested inside a subprogram.
303 bool DwarfDebug::isSubprogramContext(const MDNode *Context) {
306 DIDescriptor D(Context);
307 if (D.isSubprogram())
310 return isSubprogramContext(resolve(DIType(Context).getContext()));
314 // Find DIE for the given subprogram and attach appropriate DW_AT_low_pc
315 // and DW_AT_high_pc attributes. If there are global variables in this
316 // scope then create and insert DIEs for these variables.
317 DIE &DwarfDebug::updateSubprogramScopeDIE(DwarfCompileUnit &SPCU,
319 DIE *SPDie = SPCU.getOrCreateSubprogramDIE(SP);
321 attachLowHighPC(SPCU, *SPDie, FunctionBeginSym, FunctionEndSym);
322 if (!CurFn->getTarget().Options.DisableFramePointerElim(*CurFn))
323 SPCU.addFlag(*SPDie, dwarf::DW_AT_APPLE_omit_frame_ptr);
325 // Only include DW_AT_frame_base in full debug info
326 if (SPCU.getCUNode().getEmissionKind() != DIBuilder::LineTablesOnly) {
327 const TargetRegisterInfo *RI =
328 Asm->TM.getSubtargetImpl()->getRegisterInfo();
329 MachineLocation Location(RI->getFrameRegister(*Asm->MF));
330 SPCU.addAddress(*SPDie, dwarf::DW_AT_frame_base, Location);
333 // Add name to the name table, we do this here because we're guaranteed
334 // to have concrete versions of our DW_TAG_subprogram nodes.
335 addSubprogramNames(SP, *SPDie);
340 /// Check whether we should create a DIE for the given Scope, return true
341 /// if we don't create a DIE (the corresponding DIE is null).
342 bool DwarfDebug::isLexicalScopeDIENull(LexicalScope *Scope) {
343 if (Scope->isAbstractScope())
346 // We don't create a DIE if there is no Range.
347 const SmallVectorImpl<InsnRange> &Ranges = Scope->getRanges();
351 if (Ranges.size() > 1)
354 // We don't create a DIE if we have a single Range and the end label
356 return !getLabelAfterInsn(Ranges.front().second);
359 static void addSectionLabel(AsmPrinter &Asm, DwarfUnit &U, DIE &D,
360 dwarf::Attribute A, const MCSymbol *L,
361 const MCSymbol *Sec) {
362 if (Asm.MAI->doesDwarfUseRelocationsAcrossSections())
363 U.addSectionLabel(D, A, L);
365 U.addSectionDelta(D, A, L, Sec);
368 void DwarfDebug::addScopeRangeList(DwarfCompileUnit &TheCU, DIE &ScopeDIE,
369 const SmallVectorImpl<InsnRange> &Range) {
370 // Emit offset in .debug_range as a relocatable label. emitDIE will handle
371 // emitting it appropriately.
372 MCSymbol *RangeSym = Asm->GetTempSymbol("debug_ranges", GlobalRangeCount++);
374 // Under fission, ranges are specified by constant offsets relative to the
375 // CU's DW_AT_GNU_ranges_base.
377 TheCU.addSectionDelta(ScopeDIE, dwarf::DW_AT_ranges, RangeSym,
378 DwarfDebugRangeSectionSym);
380 addSectionLabel(*Asm, TheCU, ScopeDIE, dwarf::DW_AT_ranges, RangeSym,
381 DwarfDebugRangeSectionSym);
383 RangeSpanList List(RangeSym);
384 for (const InsnRange &R : Range) {
385 RangeSpan Span(getLabelBeforeInsn(R.first), getLabelAfterInsn(R.second));
386 List.addRange(std::move(Span));
389 // Add the range list to the set of ranges to be emitted.
390 TheCU.addRangeList(std::move(List));
393 void DwarfDebug::attachRangesOrLowHighPC(DwarfCompileUnit &TheCU, DIE &Die,
394 const SmallVectorImpl<InsnRange> &Ranges) {
395 assert(!Ranges.empty());
396 if (Ranges.size() == 1)
397 attachLowHighPC(TheCU, Die, getLabelBeforeInsn(Ranges.front().first),
398 getLabelAfterInsn(Ranges.front().second));
400 addScopeRangeList(TheCU, Die, Ranges);
403 // Construct new DW_TAG_lexical_block for this scope and attach
404 // DW_AT_low_pc/DW_AT_high_pc labels.
406 DwarfDebug::constructLexicalScopeDIE(DwarfCompileUnit &TheCU,
407 LexicalScope *Scope) {
408 if (isLexicalScopeDIENull(Scope))
411 auto ScopeDIE = make_unique<DIE>(dwarf::DW_TAG_lexical_block);
412 if (Scope->isAbstractScope())
415 attachRangesOrLowHighPC(TheCU, *ScopeDIE, Scope->getRanges());
420 // This scope represents inlined body of a function. Construct DIE to
421 // represent this concrete inlined copy of the function.
423 DwarfDebug::constructInlinedScopeDIE(DwarfCompileUnit &TheCU,
424 LexicalScope *Scope) {
425 assert(Scope->getScopeNode());
426 DIScope DS(Scope->getScopeNode());
427 DISubprogram InlinedSP = getDISubprogram(DS);
428 // Find the subprogram's DwarfCompileUnit in the SPMap in case the subprogram
429 // was inlined from another compile unit.
430 DIE *OriginDIE = AbstractSPDies[InlinedSP];
431 assert(OriginDIE && "Unable to find original DIE for an inlined subprogram.");
433 auto ScopeDIE = make_unique<DIE>(dwarf::DW_TAG_inlined_subroutine);
434 TheCU.addDIEEntry(*ScopeDIE, dwarf::DW_AT_abstract_origin, *OriginDIE);
436 attachRangesOrLowHighPC(TheCU, *ScopeDIE, Scope->getRanges());
438 InlinedSubprogramDIEs.insert(OriginDIE);
440 // Add the call site information to the DIE.
441 DILocation DL(Scope->getInlinedAt());
442 TheCU.addUInt(*ScopeDIE, dwarf::DW_AT_call_file, None,
443 TheCU.getOrCreateSourceID(DL.getFilename(), DL.getDirectory()));
444 TheCU.addUInt(*ScopeDIE, dwarf::DW_AT_call_line, None, DL.getLineNumber());
446 // Add name to the name table, we do this here because we're guaranteed
447 // to have concrete versions of our DW_TAG_inlined_subprogram nodes.
448 addSubprogramNames(InlinedSP, *ScopeDIE);
453 static std::unique_ptr<DIE> constructVariableDIE(DwarfCompileUnit &TheCU,
455 const LexicalScope &Scope,
456 DIE *&ObjectPointer) {
457 auto Var = TheCU.constructVariableDIE(DV, Scope.isAbstractScope());
458 if (DV.isObjectPointer())
459 ObjectPointer = Var.get();
463 DIE *DwarfDebug::createScopeChildrenDIE(
464 DwarfCompileUnit &TheCU, LexicalScope *Scope,
465 SmallVectorImpl<std::unique_ptr<DIE>> &Children,
466 unsigned *ChildScopeCount) {
467 DIE *ObjectPointer = nullptr;
469 for (DbgVariable *DV : ScopeVariables.lookup(Scope))
470 Children.push_back(constructVariableDIE(TheCU, *DV, *Scope, ObjectPointer));
472 unsigned ChildCountWithoutScopes = Children.size();
474 for (LexicalScope *LS : Scope->getChildren())
475 constructScopeDIE(TheCU, LS, Children);
478 *ChildScopeCount = Children.size() - ChildCountWithoutScopes;
480 return ObjectPointer;
483 DIE *DwarfDebug::createAndAddScopeChildren(DwarfCompileUnit &TheCU,
484 LexicalScope *Scope, DIE &ScopeDIE) {
485 // We create children when the scope DIE is not null.
486 SmallVector<std::unique_ptr<DIE>, 8> Children;
487 DIE *ObjectPointer = createScopeChildrenDIE(TheCU, Scope, Children);
490 for (auto &I : Children)
491 ScopeDIE.addChild(std::move(I));
493 return ObjectPointer;
496 void DwarfDebug::constructAbstractSubprogramScopeDIE(DwarfCompileUnit &TheCU,
497 LexicalScope *Scope) {
498 assert(Scope && Scope->getScopeNode());
499 assert(Scope->isAbstractScope());
500 assert(!Scope->getInlinedAt());
502 DISubprogram SP(Scope->getScopeNode());
504 ProcessedSPNodes.insert(SP);
506 DIE *&AbsDef = AbstractSPDies[SP];
510 // Find the subprogram's DwarfCompileUnit in the SPMap in case the subprogram
511 // was inlined from another compile unit.
512 DwarfCompileUnit &SPCU = *SPMap[SP];
515 // Some of this is duplicated from DwarfUnit::getOrCreateSubprogramDIE, with
516 // the important distinction that the DIDescriptor is not associated with the
517 // DIE (since the DIDescriptor will be associated with the concrete DIE, if
518 // any). It could be refactored to some common utility function.
519 if (DISubprogram SPDecl = SP.getFunctionDeclaration()) {
520 ContextDIE = &SPCU.getUnitDie();
521 SPCU.getOrCreateSubprogramDIE(SPDecl);
523 ContextDIE = SPCU.getOrCreateContextDIE(resolve(SP.getContext()));
525 // Passing null as the associated DIDescriptor because the abstract definition
526 // shouldn't be found by lookup.
527 AbsDef = &SPCU.createAndAddDIE(dwarf::DW_TAG_subprogram, *ContextDIE,
529 SPCU.applySubprogramAttributesToDefinition(SP, *AbsDef);
531 if (TheCU.getCUNode().getEmissionKind() != DIBuilder::LineTablesOnly)
532 SPCU.addUInt(*AbsDef, dwarf::DW_AT_inline, None, dwarf::DW_INL_inlined);
533 if (DIE *ObjectPointer = createAndAddScopeChildren(SPCU, Scope, *AbsDef))
534 SPCU.addDIEEntry(*AbsDef, dwarf::DW_AT_object_pointer, *ObjectPointer);
537 void DwarfDebug::constructSubprogramScopeDIE(DwarfCompileUnit &TheCU,
538 LexicalScope *Scope) {
539 assert(Scope && Scope->getScopeNode());
540 assert(!Scope->getInlinedAt());
541 assert(!Scope->isAbstractScope());
542 DISubprogram Sub(Scope->getScopeNode());
544 assert(Sub.isSubprogram());
546 ProcessedSPNodes.insert(Sub);
548 DIE &ScopeDIE = updateSubprogramScopeDIE(TheCU, Sub);
550 // Collect arguments for current function.
551 assert(LScopes.isCurrentFunctionScope(Scope));
552 DIE *ObjectPointer = nullptr;
553 for (DbgVariable *ArgDV : CurrentFnArguments)
556 constructVariableDIE(TheCU, *ArgDV, *Scope, ObjectPointer));
558 // If this is a variadic function, add an unspecified parameter.
559 DITypeArray FnArgs = Sub.getType().getTypeArray();
560 // If we have a single element of null, it is a function that returns void.
561 // If we have more than one elements and the last one is null, it is a
562 // variadic function.
563 if (FnArgs.getNumElements() > 1 &&
564 !FnArgs.getElement(FnArgs.getNumElements() - 1))
565 ScopeDIE.addChild(make_unique<DIE>(dwarf::DW_TAG_unspecified_parameters));
567 // Collect lexical scope children first.
568 // ObjectPointer might be a local (non-argument) local variable if it's a
569 // block's synthetic this pointer.
570 if (DIE *BlockObjPtr = createAndAddScopeChildren(TheCU, Scope, ScopeDIE)) {
571 assert(!ObjectPointer && "multiple object pointers can't be described");
572 ObjectPointer = BlockObjPtr;
576 TheCU.addDIEEntry(ScopeDIE, dwarf::DW_AT_object_pointer, *ObjectPointer);
579 // Construct a DIE for this scope.
580 void DwarfDebug::constructScopeDIE(
581 DwarfCompileUnit &TheCU, LexicalScope *Scope,
582 SmallVectorImpl<std::unique_ptr<DIE>> &FinalChildren) {
583 if (!Scope || !Scope->getScopeNode())
586 DIScope DS(Scope->getScopeNode());
588 assert((Scope->getInlinedAt() || !DS.isSubprogram()) &&
589 "Only handle inlined subprograms here, use "
590 "constructSubprogramScopeDIE for non-inlined "
593 SmallVector<std::unique_ptr<DIE>, 8> Children;
595 // We try to create the scope DIE first, then the children DIEs. This will
596 // avoid creating un-used children then removing them later when we find out
597 // the scope DIE is null.
598 std::unique_ptr<DIE> ScopeDIE;
599 if (Scope->getParent() && DS.isSubprogram()) {
600 ScopeDIE = constructInlinedScopeDIE(TheCU, Scope);
603 // We create children when the scope DIE is not null.
604 createScopeChildrenDIE(TheCU, Scope, Children);
606 // Early exit when we know the scope DIE is going to be null.
607 if (isLexicalScopeDIENull(Scope))
610 unsigned ChildScopeCount;
612 // We create children here when we know the scope DIE is not going to be
613 // null and the children will be added to the scope DIE.
614 createScopeChildrenDIE(TheCU, Scope, Children, &ChildScopeCount);
616 // There is no need to emit empty lexical block DIE.
617 std::pair<ImportedEntityMap::const_iterator,
618 ImportedEntityMap::const_iterator> Range =
619 std::equal_range(ScopesWithImportedEntities.begin(),
620 ScopesWithImportedEntities.end(),
621 std::pair<const MDNode *, const MDNode *>(DS, nullptr),
623 for (ImportedEntityMap::const_iterator i = Range.first; i != Range.second;
626 constructImportedEntityDIE(TheCU, DIImportedEntity(i->second)));
627 // If there are only other scopes as children, put them directly in the
628 // parent instead, as this scope would serve no purpose.
629 if (Children.size() == ChildScopeCount) {
630 FinalChildren.insert(FinalChildren.end(),
631 std::make_move_iterator(Children.begin()),
632 std::make_move_iterator(Children.end()));
635 ScopeDIE = constructLexicalScopeDIE(TheCU, Scope);
636 assert(ScopeDIE && "Scope DIE should not be null.");
640 for (auto &I : Children)
641 ScopeDIE->addChild(std::move(I));
643 FinalChildren.push_back(std::move(ScopeDIE));
646 void DwarfDebug::addGnuPubAttributes(DwarfUnit &U, DIE &D) const {
647 if (!GenerateGnuPubSections)
650 U.addFlag(D, dwarf::DW_AT_GNU_pubnames);
653 // Create new DwarfCompileUnit for the given metadata node with tag
654 // DW_TAG_compile_unit.
655 DwarfCompileUnit &DwarfDebug::constructDwarfCompileUnit(DICompileUnit DIUnit) {
656 StringRef FN = DIUnit.getFilename();
657 CompilationDir = DIUnit.getDirectory();
659 auto OwnedUnit = make_unique<DwarfCompileUnit>(
660 InfoHolder.getUnits().size(), DIUnit, Asm, this, &InfoHolder);
661 DwarfCompileUnit &NewCU = *OwnedUnit;
662 DIE &Die = NewCU.getUnitDie();
663 InfoHolder.addUnit(std::move(OwnedUnit));
665 // LTO with assembly output shares a single line table amongst multiple CUs.
666 // To avoid the compilation directory being ambiguous, let the line table
667 // explicitly describe the directory of all files, never relying on the
668 // compilation directory.
669 if (!Asm->OutStreamer.hasRawTextSupport() || SingleCU)
670 Asm->OutStreamer.getContext().setMCLineTableCompilationDir(
671 NewCU.getUniqueID(), CompilationDir);
673 NewCU.addString(Die, dwarf::DW_AT_producer, DIUnit.getProducer());
674 NewCU.addUInt(Die, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
675 DIUnit.getLanguage());
676 NewCU.addString(Die, dwarf::DW_AT_name, FN);
678 if (!useSplitDwarf()) {
679 NewCU.initStmtList(DwarfLineSectionSym);
681 // If we're using split dwarf the compilation dir is going to be in the
682 // skeleton CU and so we don't need to duplicate it here.
683 if (!CompilationDir.empty())
684 NewCU.addString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
686 addGnuPubAttributes(NewCU, Die);
689 if (DIUnit.isOptimized())
690 NewCU.addFlag(Die, dwarf::DW_AT_APPLE_optimized);
692 StringRef Flags = DIUnit.getFlags();
694 NewCU.addString(Die, dwarf::DW_AT_APPLE_flags, Flags);
696 if (unsigned RVer = DIUnit.getRunTimeVersion())
697 NewCU.addUInt(Die, dwarf::DW_AT_APPLE_major_runtime_vers,
698 dwarf::DW_FORM_data1, RVer);
703 if (useSplitDwarf()) {
704 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoDWOSection(),
705 DwarfInfoDWOSectionSym);
706 NewCU.setSkeleton(constructSkeletonCU(NewCU));
708 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoSection(),
709 DwarfInfoSectionSym);
711 CUMap.insert(std::make_pair(DIUnit, &NewCU));
712 CUDieMap.insert(std::make_pair(&Die, &NewCU));
716 void DwarfDebug::constructAndAddImportedEntityDIE(DwarfCompileUnit &TheCU,
718 DIImportedEntity Module(N);
719 assert(Module.Verify());
720 if (DIE *D = TheCU.getOrCreateContextDIE(Module.getContext()))
721 D->addChild(constructImportedEntityDIE(TheCU, Module));
725 DwarfDebug::constructImportedEntityDIE(DwarfCompileUnit &TheCU,
726 const DIImportedEntity &Module) {
727 assert(Module.Verify() &&
728 "Use one of the MDNode * overloads to handle invalid metadata");
729 std::unique_ptr<DIE> IMDie = make_unique<DIE>((dwarf::Tag)Module.getTag());
730 TheCU.insertDIE(Module, IMDie.get());
732 DIDescriptor Entity = resolve(Module.getEntity());
733 if (Entity.isNameSpace())
734 EntityDie = TheCU.getOrCreateNameSpace(DINameSpace(Entity));
735 else if (Entity.isSubprogram())
736 EntityDie = TheCU.getOrCreateSubprogramDIE(DISubprogram(Entity));
737 else if (Entity.isType())
738 EntityDie = TheCU.getOrCreateTypeDIE(DIType(Entity));
740 EntityDie = TheCU.getDIE(Entity);
742 TheCU.addSourceLine(*IMDie, Module.getLineNumber(),
743 Module.getContext().getFilename(),
744 Module.getContext().getDirectory());
745 TheCU.addDIEEntry(*IMDie, dwarf::DW_AT_import, *EntityDie);
746 StringRef Name = Module.getName();
748 TheCU.addString(*IMDie, dwarf::DW_AT_name, Name);
753 // Emit all Dwarf sections that should come prior to the content. Create
754 // global DIEs and emit initial debug info sections. This is invoked by
755 // the target AsmPrinter.
756 void DwarfDebug::beginModule() {
757 if (DisableDebugInfoPrinting)
760 const Module *M = MMI->getModule();
762 FunctionDIs = makeSubprogramMap(*M);
764 // If module has named metadata anchors then use them, otherwise scan the
765 // module using debug info finder to collect debug info.
766 NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
769 TypeIdentifierMap = generateDITypeIdentifierMap(CU_Nodes);
771 // Emit initial sections so we can reference labels later.
774 SingleCU = CU_Nodes->getNumOperands() == 1;
776 for (MDNode *N : CU_Nodes->operands()) {
777 DICompileUnit CUNode(N);
778 DwarfCompileUnit &CU = constructDwarfCompileUnit(CUNode);
779 DIArray ImportedEntities = CUNode.getImportedEntities();
780 for (unsigned i = 0, e = ImportedEntities.getNumElements(); i != e; ++i)
781 ScopesWithImportedEntities.push_back(std::make_pair(
782 DIImportedEntity(ImportedEntities.getElement(i)).getContext(),
783 ImportedEntities.getElement(i)));
784 std::sort(ScopesWithImportedEntities.begin(),
785 ScopesWithImportedEntities.end(), less_first());
786 DIArray GVs = CUNode.getGlobalVariables();
787 for (unsigned i = 0, e = GVs.getNumElements(); i != e; ++i)
788 CU.getOrCreateGlobalVariableDIE(DIGlobalVariable(GVs.getElement(i)));
789 DIArray SPs = CUNode.getSubprograms();
790 for (unsigned i = 0, e = SPs.getNumElements(); i != e; ++i)
791 SPMap.insert(std::make_pair(SPs.getElement(i), &CU));
792 DIArray EnumTypes = CUNode.getEnumTypes();
793 for (unsigned i = 0, e = EnumTypes.getNumElements(); i != e; ++i) {
794 DIType Ty(EnumTypes.getElement(i));
795 // The enum types array by design contains pointers to
796 // MDNodes rather than DIRefs. Unique them here.
797 DIType UniqueTy(resolve(Ty.getRef()));
798 CU.getOrCreateTypeDIE(UniqueTy);
800 DIArray RetainedTypes = CUNode.getRetainedTypes();
801 for (unsigned i = 0, e = RetainedTypes.getNumElements(); i != e; ++i) {
802 DIType Ty(RetainedTypes.getElement(i));
803 // The retained types array by design contains pointers to
804 // MDNodes rather than DIRefs. Unique them here.
805 DIType UniqueTy(resolve(Ty.getRef()));
806 CU.getOrCreateTypeDIE(UniqueTy);
808 // Emit imported_modules last so that the relevant context is already
810 for (unsigned i = 0, e = ImportedEntities.getNumElements(); i != e; ++i)
811 constructAndAddImportedEntityDIE(CU, ImportedEntities.getElement(i));
814 // Tell MMI that we have debug info.
815 MMI->setDebugInfoAvailability(true);
817 // Prime section data.
818 SectionMap[Asm->getObjFileLowering().getTextSection()];
821 void DwarfDebug::finishVariableDefinitions() {
822 for (const auto &Var : ConcreteVariables) {
823 DIE *VariableDie = Var->getDIE();
825 // FIXME: Consider the time-space tradeoff of just storing the unit pointer
826 // in the ConcreteVariables list, rather than looking it up again here.
827 // DIE::getUnit isn't simple - it walks parent pointers, etc.
828 DwarfCompileUnit *Unit = lookupUnit(VariableDie->getUnit());
830 DbgVariable *AbsVar = getExistingAbstractVariable(Var->getVariable());
831 if (AbsVar && AbsVar->getDIE()) {
832 Unit->addDIEEntry(*VariableDie, dwarf::DW_AT_abstract_origin,
835 Unit->applyVariableAttributes(*Var, *VariableDie);
839 void DwarfDebug::finishSubprogramDefinitions() {
840 const Module *M = MMI->getModule();
842 NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
843 for (MDNode *N : CU_Nodes->operands()) {
844 DICompileUnit TheCU(N);
845 // Construct subprogram DIE and add variables DIEs.
846 DwarfCompileUnit *SPCU =
847 static_cast<DwarfCompileUnit *>(CUMap.lookup(TheCU));
848 DIArray Subprograms = TheCU.getSubprograms();
849 for (unsigned i = 0, e = Subprograms.getNumElements(); i != e; ++i) {
850 DISubprogram SP(Subprograms.getElement(i));
851 // Perhaps the subprogram is in another CU (such as due to comdat
852 // folding, etc), in which case ignore it here.
853 if (SPMap[SP] != SPCU)
855 DIE *D = SPCU->getDIE(SP);
856 if (DIE *AbsSPDIE = AbstractSPDies.lookup(SP)) {
858 // If this subprogram has an abstract definition, reference that
859 SPCU->addDIEEntry(*D, dwarf::DW_AT_abstract_origin, *AbsSPDIE);
861 if (!D && TheCU.getEmissionKind() != DIBuilder::LineTablesOnly)
862 // Lazily construct the subprogram if we didn't see either concrete or
863 // inlined versions during codegen. (except in -gmlt ^ where we want
864 // to omit these entirely)
865 D = SPCU->getOrCreateSubprogramDIE(SP);
867 // And attach the attributes
868 SPCU->applySubprogramAttributesToDefinition(SP, *D);
875 // Collect info for variables that were optimized out.
876 void DwarfDebug::collectDeadVariables() {
877 const Module *M = MMI->getModule();
879 if (NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu")) {
880 for (MDNode *N : CU_Nodes->operands()) {
881 DICompileUnit TheCU(N);
882 // Construct subprogram DIE and add variables DIEs.
883 DwarfCompileUnit *SPCU =
884 static_cast<DwarfCompileUnit *>(CUMap.lookup(TheCU));
885 assert(SPCU && "Unable to find Compile Unit!");
886 DIArray Subprograms = TheCU.getSubprograms();
887 for (unsigned i = 0, e = Subprograms.getNumElements(); i != e; ++i) {
888 DISubprogram SP(Subprograms.getElement(i));
889 if (ProcessedSPNodes.count(SP) != 0)
891 assert(SP.isSubprogram() &&
892 "CU's subprogram list contains a non-subprogram");
893 assert(SP.isDefinition() &&
894 "CU's subprogram list contains a subprogram declaration");
895 DIArray Variables = SP.getVariables();
896 if (Variables.getNumElements() == 0)
899 DIE *SPDIE = AbstractSPDies.lookup(SP);
901 SPDIE = SPCU->getDIE(SP);
903 for (unsigned vi = 0, ve = Variables.getNumElements(); vi != ve; ++vi) {
904 DIVariable DV(Variables.getElement(vi));
905 assert(DV.isVariable());
906 DbgVariable NewVar(DV, DIExpression(nullptr), this);
907 auto VariableDie = SPCU->constructVariableDIE(NewVar);
908 SPCU->applyVariableAttributes(NewVar, *VariableDie);
909 SPDIE->addChild(std::move(VariableDie));
916 void DwarfDebug::finalizeModuleInfo() {
917 finishSubprogramDefinitions();
919 finishVariableDefinitions();
921 // Collect info for variables that were optimized out.
922 collectDeadVariables();
924 // Handle anything that needs to be done on a per-unit basis after
925 // all other generation.
926 for (const auto &TheU : getUnits()) {
927 // Emit DW_AT_containing_type attribute to connect types with their
928 // vtable holding type.
929 TheU->constructContainingTypeDIEs();
931 // Add CU specific attributes if we need to add any.
932 if (TheU->getUnitDie().getTag() == dwarf::DW_TAG_compile_unit) {
933 // If we're splitting the dwarf out now that we've got the entire
934 // CU then add the dwo id to it.
935 DwarfCompileUnit *SkCU =
936 static_cast<DwarfCompileUnit *>(TheU->getSkeleton());
937 if (useSplitDwarf()) {
938 // Emit a unique identifier for this CU.
939 uint64_t ID = DIEHash(Asm).computeCUSignature(TheU->getUnitDie());
940 TheU->addUInt(TheU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
941 dwarf::DW_FORM_data8, ID);
942 SkCU->addUInt(SkCU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
943 dwarf::DW_FORM_data8, ID);
945 // We don't keep track of which addresses are used in which CU so this
946 // is a bit pessimistic under LTO.
947 if (!AddrPool.isEmpty())
948 addSectionLabel(*Asm, *SkCU, SkCU->getUnitDie(),
949 dwarf::DW_AT_GNU_addr_base, DwarfAddrSectionSym,
950 DwarfAddrSectionSym);
951 if (!TheU->getRangeLists().empty())
952 addSectionLabel(*Asm, *SkCU, SkCU->getUnitDie(),
953 dwarf::DW_AT_GNU_ranges_base,
954 DwarfDebugRangeSectionSym, DwarfDebugRangeSectionSym);
957 // If we have code split among multiple sections or non-contiguous
958 // ranges of code then emit a DW_AT_ranges attribute on the unit that will
959 // remain in the .o file, otherwise add a DW_AT_low_pc.
960 // FIXME: We should use ranges allow reordering of code ala
961 // .subsections_via_symbols in mach-o. This would mean turning on
962 // ranges for all subprogram DIEs for mach-o.
963 DwarfCompileUnit &U =
964 SkCU ? *SkCU : static_cast<DwarfCompileUnit &>(*TheU);
965 unsigned NumRanges = TheU->getRanges().size();
968 addSectionLabel(*Asm, U, U.getUnitDie(), dwarf::DW_AT_ranges,
969 Asm->GetTempSymbol("cu_ranges", U.getUniqueID()),
970 DwarfDebugRangeSectionSym);
972 // A DW_AT_low_pc attribute may also be specified in combination with
973 // DW_AT_ranges to specify the default base address for use in
974 // location lists (see Section 2.6.2) and range lists (see Section
976 U.addUInt(U.getUnitDie(), dwarf::DW_AT_low_pc, dwarf::DW_FORM_addr,
979 RangeSpan &Range = TheU->getRanges().back();
980 attachLowHighPC(U, U.getUnitDie(), Range.getStart(), Range.getEnd());
986 // Compute DIE offsets and sizes.
987 InfoHolder.computeSizeAndOffsets();
989 SkeletonHolder.computeSizeAndOffsets();
992 void DwarfDebug::endSections() {
993 // Filter labels by section.
994 for (const SymbolCU &SCU : ArangeLabels) {
995 if (SCU.Sym->isInSection()) {
996 // Make a note of this symbol and it's section.
997 const MCSection *Section = &SCU.Sym->getSection();
998 if (!Section->getKind().isMetadata())
999 SectionMap[Section].push_back(SCU);
1001 // Some symbols (e.g. common/bss on mach-o) can have no section but still
1002 // appear in the output. This sucks as we rely on sections to build
1003 // arange spans. We can do it without, but it's icky.
1004 SectionMap[nullptr].push_back(SCU);
1008 // Build a list of sections used.
1009 std::vector<const MCSection *> Sections;
1010 for (const auto &it : SectionMap) {
1011 const MCSection *Section = it.first;
1012 Sections.push_back(Section);
1015 // Sort the sections into order.
1016 // This is only done to ensure consistent output order across different runs.
1017 std::sort(Sections.begin(), Sections.end(), SectionSort);
1019 // Add terminating symbols for each section.
1020 for (unsigned ID = 0, E = Sections.size(); ID != E; ID++) {
1021 const MCSection *Section = Sections[ID];
1022 MCSymbol *Sym = nullptr;
1025 // We can't call MCSection::getLabelEndName, as it's only safe to do so
1026 // if we know the section name up-front. For user-created sections, the
1027 // resulting label may not be valid to use as a label. (section names can
1028 // use a greater set of characters on some systems)
1029 Sym = Asm->GetTempSymbol("debug_end", ID);
1030 Asm->OutStreamer.SwitchSection(Section);
1031 Asm->OutStreamer.EmitLabel(Sym);
1034 // Insert a final terminator.
1035 SectionMap[Section].push_back(SymbolCU(nullptr, Sym));
1039 // Emit all Dwarf sections that should come after the content.
1040 void DwarfDebug::endModule() {
1041 assert(CurFn == nullptr);
1042 assert(CurMI == nullptr);
1047 // End any existing sections.
1048 // TODO: Does this need to happen?
1051 // Finalize the debug info for the module.
1052 finalizeModuleInfo();
1056 // Emit all the DIEs into a debug info section.
1059 // Corresponding abbreviations into a abbrev section.
1060 emitAbbreviations();
1062 // Emit info into a debug aranges section.
1063 if (GenerateARangeSection)
1066 // Emit info into a debug ranges section.
1069 if (useSplitDwarf()) {
1072 emitDebugAbbrevDWO();
1075 // Emit DWO addresses.
1076 AddrPool.emit(*Asm, Asm->getObjFileLowering().getDwarfAddrSection());
1078 // Emit info into a debug loc section.
1081 // Emit info into the dwarf accelerator table sections.
1082 if (useDwarfAccelTables()) {
1085 emitAccelNamespaces();
1089 // Emit the pubnames and pubtypes sections if requested.
1090 if (HasDwarfPubSections) {
1091 emitDebugPubNames(GenerateGnuPubSections);
1092 emitDebugPubTypes(GenerateGnuPubSections);
1097 AbstractVariables.clear();
1099 // Reset these for the next Module if we have one.
1103 // Find abstract variable, if any, associated with Var.
1104 DbgVariable *DwarfDebug::getExistingAbstractVariable(const DIVariable &DV,
1105 DIVariable &Cleansed) {
1106 LLVMContext &Ctx = DV->getContext();
1107 // More then one inlined variable corresponds to one abstract variable.
1108 // FIXME: This duplication of variables when inlining should probably be
1109 // removed. It's done to allow each DIVariable to describe its location
1110 // because the DebugLoc on the dbg.value/declare isn't accurate. We should
1111 // make it accurate then remove this duplication/cleansing stuff.
1112 Cleansed = cleanseInlinedVariable(DV, Ctx);
1113 auto I = AbstractVariables.find(Cleansed);
1114 if (I != AbstractVariables.end())
1115 return I->second.get();
1119 DbgVariable *DwarfDebug::getExistingAbstractVariable(const DIVariable &DV) {
1120 DIVariable Cleansed;
1121 return getExistingAbstractVariable(DV, Cleansed);
1124 void DwarfDebug::createAbstractVariable(const DIVariable &Var,
1125 LexicalScope *Scope) {
1126 auto AbsDbgVariable = make_unique<DbgVariable>(Var, DIExpression(), this);
1127 addScopeVariable(Scope, AbsDbgVariable.get());
1128 AbstractVariables[Var] = std::move(AbsDbgVariable);
1131 void DwarfDebug::ensureAbstractVariableIsCreated(const DIVariable &DV,
1132 const MDNode *ScopeNode) {
1133 DIVariable Cleansed = DV;
1134 if (getExistingAbstractVariable(DV, Cleansed))
1137 createAbstractVariable(Cleansed, LScopes.getOrCreateAbstractScope(ScopeNode));
1141 DwarfDebug::ensureAbstractVariableIsCreatedIfScoped(const DIVariable &DV,
1142 const MDNode *ScopeNode) {
1143 DIVariable Cleansed = DV;
1144 if (getExistingAbstractVariable(DV, Cleansed))
1147 if (LexicalScope *Scope = LScopes.findAbstractScope(ScopeNode))
1148 createAbstractVariable(Cleansed, Scope);
1151 // If Var is a current function argument then add it to CurrentFnArguments list.
1152 bool DwarfDebug::addCurrentFnArgument(DbgVariable *Var, LexicalScope *Scope) {
1153 if (!LScopes.isCurrentFunctionScope(Scope))
1155 DIVariable DV = Var->getVariable();
1156 if (DV.getTag() != dwarf::DW_TAG_arg_variable)
1158 unsigned ArgNo = DV.getArgNumber();
1162 size_t Size = CurrentFnArguments.size();
1164 CurrentFnArguments.resize(CurFn->getFunction()->arg_size());
1165 // llvm::Function argument size is not good indicator of how many
1166 // arguments does the function have at source level.
1168 CurrentFnArguments.resize(ArgNo * 2);
1169 assert(!CurrentFnArguments[ArgNo - 1]);
1170 CurrentFnArguments[ArgNo - 1] = Var;
1174 // Collect variable information from side table maintained by MMI.
1175 void DwarfDebug::collectVariableInfoFromMMITable(
1176 SmallPtrSetImpl<const MDNode *> &Processed) {
1177 for (const auto &VI : MMI->getVariableDbgInfo()) {
1180 Processed.insert(VI.Var);
1181 DIVariable DV(VI.Var);
1182 DIExpression Expr(VI.Expr);
1183 LexicalScope *Scope = LScopes.findLexicalScope(VI.Loc);
1185 // If variable scope is not found then skip this variable.
1189 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
1190 ConcreteVariables.push_back(make_unique<DbgVariable>(DV, Expr, this));
1191 DbgVariable *RegVar = ConcreteVariables.back().get();
1192 RegVar->setFrameIndex(VI.Slot);
1193 addScopeVariable(Scope, RegVar);
1197 // Get .debug_loc entry for the instruction range starting at MI.
1198 static DebugLocEntry::Value getDebugLocValue(const MachineInstr *MI) {
1199 const MDNode *Expr = MI->getDebugExpression();
1200 const MDNode *Var = MI->getDebugVariable();
1202 assert(MI->getNumOperands() == 4);
1203 if (MI->getOperand(0).isReg()) {
1204 MachineLocation MLoc;
1205 // If the second operand is an immediate, this is a
1206 // register-indirect address.
1207 if (!MI->getOperand(1).isImm())
1208 MLoc.set(MI->getOperand(0).getReg());
1210 MLoc.set(MI->getOperand(0).getReg(), MI->getOperand(1).getImm());
1211 return DebugLocEntry::Value(Var, Expr, MLoc);
1213 if (MI->getOperand(0).isImm())
1214 return DebugLocEntry::Value(Var, Expr, MI->getOperand(0).getImm());
1215 if (MI->getOperand(0).isFPImm())
1216 return DebugLocEntry::Value(Var, Expr, MI->getOperand(0).getFPImm());
1217 if (MI->getOperand(0).isCImm())
1218 return DebugLocEntry::Value(Var, Expr, MI->getOperand(0).getCImm());
1220 llvm_unreachable("Unexpected 4-operand DBG_VALUE instruction!");
1223 /// Determine whether two variable pieces overlap.
1224 static bool piecesOverlap(DIExpression P1, DIExpression P2) {
1225 if (!P1.isVariablePiece() || !P2.isVariablePiece())
1227 unsigned l1 = P1.getPieceOffset();
1228 unsigned l2 = P2.getPieceOffset();
1229 unsigned r1 = l1 + P1.getPieceSize();
1230 unsigned r2 = l2 + P2.getPieceSize();
1231 // True where [l1,r1[ and [r1,r2[ overlap.
1232 return (l1 < r2) && (l2 < r1);
1235 /// Build the location list for all DBG_VALUEs in the function that
1236 /// describe the same variable. If the ranges of several independent
1237 /// pieces of the same variable overlap partially, split them up and
1238 /// combine the ranges. The resulting DebugLocEntries are will have
1239 /// strict monotonically increasing begin addresses and will never
1244 // Ranges History [var, loc, piece ofs size]
1245 // 0 | [x, (reg0, piece 0, 32)]
1246 // 1 | | [x, (reg1, piece 32, 32)] <- IsPieceOfPrevEntry
1248 // 3 | [clobber reg0]
1249 // 4 [x, (mem, piece 0, 64)] <- overlapping with both previous pieces of x.
1253 // [0-1] [x, (reg0, piece 0, 32)]
1254 // [1-3] [x, (reg0, piece 0, 32), (reg1, piece 32, 32)]
1255 // [3-4] [x, (reg1, piece 32, 32)]
1256 // [4- ] [x, (mem, piece 0, 64)]
1258 DwarfDebug::buildLocationList(SmallVectorImpl<DebugLocEntry> &DebugLoc,
1259 const DbgValueHistoryMap::InstrRanges &Ranges) {
1260 SmallVector<DebugLocEntry::Value, 4> OpenRanges;
1262 for (auto I = Ranges.begin(), E = Ranges.end(); I != E; ++I) {
1263 const MachineInstr *Begin = I->first;
1264 const MachineInstr *End = I->second;
1265 assert(Begin->isDebugValue() && "Invalid History entry");
1267 // Check if a variable is inaccessible in this range.
1268 if (Begin->getNumOperands() > 1 &&
1269 Begin->getOperand(0).isReg() && !Begin->getOperand(0).getReg()) {
1274 // If this piece overlaps with any open ranges, truncate them.
1275 DIExpression DIExpr = Begin->getDebugExpression();
1276 auto Last = std::remove_if(OpenRanges.begin(), OpenRanges.end(),
1277 [&](DebugLocEntry::Value R) {
1278 return piecesOverlap(DIExpr, R.getExpression());
1280 OpenRanges.erase(Last, OpenRanges.end());
1282 const MCSymbol *StartLabel = getLabelBeforeInsn(Begin);
1283 assert(StartLabel && "Forgot label before DBG_VALUE starting a range!");
1285 const MCSymbol *EndLabel;
1287 EndLabel = getLabelAfterInsn(End);
1288 else if (std::next(I) == Ranges.end())
1289 EndLabel = FunctionEndSym;
1291 EndLabel = getLabelBeforeInsn(std::next(I)->first);
1292 assert(EndLabel && "Forgot label after instruction ending a range!");
1294 DEBUG(dbgs() << "DotDebugLoc: " << *Begin << "\n");
1296 auto Value = getDebugLocValue(Begin);
1297 DebugLocEntry Loc(StartLabel, EndLabel, Value);
1298 bool couldMerge = false;
1300 // If this is a piece, it may belong to the current DebugLocEntry.
1301 if (DIExpr.isVariablePiece()) {
1302 // Add this value to the list of open ranges.
1303 OpenRanges.push_back(Value);
1305 // Attempt to add the piece to the last entry.
1306 if (!DebugLoc.empty())
1307 if (DebugLoc.back().MergeValues(Loc))
1312 // Need to add a new DebugLocEntry. Add all values from still
1313 // valid non-overlapping pieces.
1314 if (OpenRanges.size())
1315 Loc.addValues(OpenRanges);
1317 DebugLoc.push_back(std::move(Loc));
1320 // Attempt to coalesce the ranges of two otherwise identical
1322 auto CurEntry = DebugLoc.rbegin();
1323 auto PrevEntry = std::next(CurEntry);
1324 if (PrevEntry != DebugLoc.rend() && PrevEntry->MergeRanges(*CurEntry))
1325 DebugLoc.pop_back();
1328 dbgs() << CurEntry->getValues().size() << " Values:\n";
1329 for (auto Value : CurEntry->getValues()) {
1330 Value.getVariable()->dump();
1331 Value.getExpression()->dump();
1333 dbgs() << "-----\n";
1339 // Find variables for each lexical scope.
1341 DwarfDebug::collectVariableInfo(SmallPtrSetImpl<const MDNode *> &Processed) {
1342 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1343 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1345 // Grab the variable info that was squirreled away in the MMI side-table.
1346 collectVariableInfoFromMMITable(Processed);
1348 for (const auto &I : DbgValues) {
1349 DIVariable DV(I.first);
1350 if (Processed.count(DV))
1353 // Instruction ranges, specifying where DV is accessible.
1354 const auto &Ranges = I.second;
1358 LexicalScope *Scope = nullptr;
1359 if (MDNode *IA = DV.getInlinedAt()) {
1360 DebugLoc DL = DebugLoc::getFromDILocation(IA);
1361 Scope = LScopes.findInlinedScope(DebugLoc::get(
1362 DL.getLine(), DL.getCol(), DV.getContext(), IA));
1364 Scope = LScopes.findLexicalScope(DV.getContext());
1365 // If variable scope is not found then skip this variable.
1369 Processed.insert(DV);
1370 const MachineInstr *MInsn = Ranges.front().first;
1371 assert(MInsn->isDebugValue() && "History must begin with debug value");
1372 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
1373 ConcreteVariables.push_back(make_unique<DbgVariable>(MInsn, this));
1374 DbgVariable *RegVar = ConcreteVariables.back().get();
1375 addScopeVariable(Scope, RegVar);
1377 // Check if the first DBG_VALUE is valid for the rest of the function.
1378 if (Ranges.size() == 1 && Ranges.front().second == nullptr)
1381 // Handle multiple DBG_VALUE instructions describing one variable.
1382 RegVar->setDotDebugLocOffset(DotDebugLocEntries.size());
1384 DotDebugLocEntries.resize(DotDebugLocEntries.size() + 1);
1385 DebugLocList &LocList = DotDebugLocEntries.back();
1388 Asm->GetTempSymbol("debug_loc", DotDebugLocEntries.size() - 1);
1390 // Build the location list for this variable.
1391 buildLocationList(LocList.List, Ranges);
1394 // Collect info for variables that were optimized out.
1395 DIArray Variables = DISubprogram(FnScope->getScopeNode()).getVariables();
1396 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1397 DIVariable DV(Variables.getElement(i));
1398 assert(DV.isVariable());
1399 if (!Processed.insert(DV))
1401 if (LexicalScope *Scope = LScopes.findLexicalScope(DV.getContext())) {
1402 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
1403 DIExpression NoExpr;
1404 ConcreteVariables.push_back(make_unique<DbgVariable>(DV, NoExpr, this));
1405 addScopeVariable(Scope, ConcreteVariables.back().get());
1410 // Return Label preceding the instruction.
1411 MCSymbol *DwarfDebug::getLabelBeforeInsn(const MachineInstr *MI) {
1412 MCSymbol *Label = LabelsBeforeInsn.lookup(MI);
1413 assert(Label && "Didn't insert label before instruction");
1417 // Return Label immediately following the instruction.
1418 MCSymbol *DwarfDebug::getLabelAfterInsn(const MachineInstr *MI) {
1419 return LabelsAfterInsn.lookup(MI);
1422 // Process beginning of an instruction.
1423 void DwarfDebug::beginInstruction(const MachineInstr *MI) {
1424 assert(CurMI == nullptr);
1426 // Check if source location changes, but ignore DBG_VALUE locations.
1427 if (!MI->isDebugValue()) {
1428 DebugLoc DL = MI->getDebugLoc();
1429 if (DL != PrevInstLoc && (!DL.isUnknown() || UnknownLocations)) {
1432 if (DL == PrologEndLoc) {
1433 Flags |= DWARF2_FLAG_PROLOGUE_END;
1434 PrologEndLoc = DebugLoc();
1436 if (PrologEndLoc.isUnknown())
1437 Flags |= DWARF2_FLAG_IS_STMT;
1439 if (!DL.isUnknown()) {
1440 const MDNode *Scope = DL.getScope(Asm->MF->getFunction()->getContext());
1441 recordSourceLine(DL.getLine(), DL.getCol(), Scope, Flags);
1443 recordSourceLine(0, 0, nullptr, 0);
1447 // Insert labels where requested.
1448 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1449 LabelsBeforeInsn.find(MI);
1452 if (I == LabelsBeforeInsn.end())
1455 // Label already assigned.
1460 PrevLabel = MMI->getContext().CreateTempSymbol();
1461 Asm->OutStreamer.EmitLabel(PrevLabel);
1463 I->second = PrevLabel;
1466 // Process end of an instruction.
1467 void DwarfDebug::endInstruction() {
1468 assert(CurMI != nullptr);
1469 // Don't create a new label after DBG_VALUE instructions.
1470 // They don't generate code.
1471 if (!CurMI->isDebugValue())
1472 PrevLabel = nullptr;
1474 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1475 LabelsAfterInsn.find(CurMI);
1479 if (I == LabelsAfterInsn.end())
1482 // Label already assigned.
1486 // We need a label after this instruction.
1488 PrevLabel = MMI->getContext().CreateTempSymbol();
1489 Asm->OutStreamer.EmitLabel(PrevLabel);
1491 I->second = PrevLabel;
1494 // Each LexicalScope has first instruction and last instruction to mark
1495 // beginning and end of a scope respectively. Create an inverse map that list
1496 // scopes starts (and ends) with an instruction. One instruction may start (or
1497 // end) multiple scopes. Ignore scopes that are not reachable.
1498 void DwarfDebug::identifyScopeMarkers() {
1499 SmallVector<LexicalScope *, 4> WorkList;
1500 WorkList.push_back(LScopes.getCurrentFunctionScope());
1501 while (!WorkList.empty()) {
1502 LexicalScope *S = WorkList.pop_back_val();
1504 const SmallVectorImpl<LexicalScope *> &Children = S->getChildren();
1505 if (!Children.empty())
1506 WorkList.append(Children.begin(), Children.end());
1508 if (S->isAbstractScope())
1511 for (const InsnRange &R : S->getRanges()) {
1512 assert(R.first && "InsnRange does not have first instruction!");
1513 assert(R.second && "InsnRange does not have second instruction!");
1514 requestLabelBeforeInsn(R.first);
1515 requestLabelAfterInsn(R.second);
1520 static DebugLoc findPrologueEndLoc(const MachineFunction *MF) {
1521 // First known non-DBG_VALUE and non-frame setup location marks
1522 // the beginning of the function body.
1523 for (const auto &MBB : *MF)
1524 for (const auto &MI : MBB)
1525 if (!MI.isDebugValue() && !MI.getFlag(MachineInstr::FrameSetup) &&
1526 !MI.getDebugLoc().isUnknown())
1527 return MI.getDebugLoc();
1531 // Gather pre-function debug information. Assumes being called immediately
1532 // after the function entry point has been emitted.
1533 void DwarfDebug::beginFunction(const MachineFunction *MF) {
1536 // If there's no debug info for the function we're not going to do anything.
1537 if (!MMI->hasDebugInfo())
1540 auto DI = FunctionDIs.find(MF->getFunction());
1541 if (DI == FunctionDIs.end())
1544 // Grab the lexical scopes for the function, if we don't have any of those
1545 // then we're not going to be able to do anything.
1546 LScopes.initialize(*MF);
1547 if (LScopes.empty())
1550 assert(DbgValues.empty() && "DbgValues map wasn't cleaned!");
1552 // Make sure that each lexical scope will have a begin/end label.
1553 identifyScopeMarkers();
1555 // Set DwarfDwarfCompileUnitID in MCContext to the Compile Unit this function
1556 // belongs to so that we add to the correct per-cu line table in the
1558 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1559 // FnScope->getScopeNode() and DI->second should represent the same function,
1560 // though they may not be the same MDNode due to inline functions merged in
1561 // LTO where the debug info metadata still differs (either due to distinct
1562 // written differences - two versions of a linkonce_odr function
1563 // written/copied into two separate files, or some sub-optimal metadata that
1564 // isn't structurally identical (see: file path/name info from clang, which
1565 // includes the directory of the cpp file being built, even when the file name
1566 // is absolute (such as an <> lookup header)))
1567 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1568 assert(TheCU && "Unable to find compile unit!");
1569 if (Asm->OutStreamer.hasRawTextSupport())
1570 // Use a single line table if we are generating assembly.
1571 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1573 Asm->OutStreamer.getContext().setDwarfCompileUnitID(TheCU->getUniqueID());
1575 // Emit a label for the function so that we have a beginning address.
1576 FunctionBeginSym = Asm->GetTempSymbol("func_begin", Asm->getFunctionNumber());
1577 // Assumes in correct section after the entry point.
1578 Asm->OutStreamer.EmitLabel(FunctionBeginSym);
1580 // Calculate history for local variables.
1581 calculateDbgValueHistory(MF, Asm->TM.getSubtargetImpl()->getRegisterInfo(),
1584 // Request labels for the full history.
1585 for (const auto &I : DbgValues) {
1586 const auto &Ranges = I.second;
1590 // The first mention of a function argument gets the FunctionBeginSym
1591 // label, so arguments are visible when breaking at function entry.
1592 DIVariable DIVar(Ranges.front().first->getDebugVariable());
1593 if (DIVar.isVariable() && DIVar.getTag() == dwarf::DW_TAG_arg_variable &&
1594 getDISubprogram(DIVar.getContext()).describes(MF->getFunction())) {
1595 LabelsBeforeInsn[Ranges.front().first] = FunctionBeginSym;
1596 if (Ranges.front().first->getDebugExpression().isVariablePiece()) {
1597 // Mark all non-overlapping initial pieces.
1598 for (auto I = Ranges.begin(); I != Ranges.end(); ++I) {
1599 DIExpression Piece = I->first->getDebugExpression();
1600 if (std::all_of(Ranges.begin(), I,
1601 [&](DbgValueHistoryMap::InstrRange Pred) {
1602 return !piecesOverlap(Piece, Pred.first->getDebugExpression());
1604 LabelsBeforeInsn[I->first] = FunctionBeginSym;
1611 for (const auto &Range : Ranges) {
1612 requestLabelBeforeInsn(Range.first);
1614 requestLabelAfterInsn(Range.second);
1618 PrevInstLoc = DebugLoc();
1619 PrevLabel = FunctionBeginSym;
1621 // Record beginning of function.
1622 PrologEndLoc = findPrologueEndLoc(MF);
1623 if (!PrologEndLoc.isUnknown()) {
1624 DebugLoc FnStartDL =
1625 PrologEndLoc.getFnDebugLoc(MF->getFunction()->getContext());
1627 FnStartDL.getLine(), FnStartDL.getCol(),
1628 FnStartDL.getScope(MF->getFunction()->getContext()),
1629 // We'd like to list the prologue as "not statements" but GDB behaves
1630 // poorly if we do that. Revisit this with caution/GDB (7.5+) testing.
1631 DWARF2_FLAG_IS_STMT);
1635 void DwarfDebug::addScopeVariable(LexicalScope *LS, DbgVariable *Var) {
1636 if (addCurrentFnArgument(Var, LS))
1638 SmallVectorImpl<DbgVariable *> &Vars = ScopeVariables[LS];
1639 DIVariable DV = Var->getVariable();
1640 // Variables with positive arg numbers are parameters.
1641 if (unsigned ArgNum = DV.getArgNumber()) {
1642 // Keep all parameters in order at the start of the variable list to ensure
1643 // function types are correct (no out-of-order parameters)
1645 // This could be improved by only doing it for optimized builds (unoptimized
1646 // builds have the right order to begin with), searching from the back (this
1647 // would catch the unoptimized case quickly), or doing a binary search
1648 // rather than linear search.
1649 SmallVectorImpl<DbgVariable *>::iterator I = Vars.begin();
1650 while (I != Vars.end()) {
1651 unsigned CurNum = (*I)->getVariable().getArgNumber();
1652 // A local (non-parameter) variable has been found, insert immediately
1656 // A later indexed parameter has been found, insert immediately before it.
1657 if (CurNum > ArgNum)
1661 Vars.insert(I, Var);
1665 Vars.push_back(Var);
1668 // Gather and emit post-function debug information.
1669 void DwarfDebug::endFunction(const MachineFunction *MF) {
1670 // Every beginFunction(MF) call should be followed by an endFunction(MF) call,
1671 // though the beginFunction may not be called at all.
1672 // We should handle both cases.
1676 assert(CurFn == MF);
1677 assert(CurFn != nullptr);
1679 if (!MMI->hasDebugInfo() || LScopes.empty() ||
1680 !FunctionDIs.count(MF->getFunction())) {
1681 // If we don't have a lexical scope for this function then there will
1682 // be a hole in the range information. Keep note of this by setting the
1683 // previously used section to nullptr.
1689 // Define end label for subprogram.
1690 FunctionEndSym = Asm->GetTempSymbol("func_end", Asm->getFunctionNumber());
1691 // Assumes in correct section after the entry point.
1692 Asm->OutStreamer.EmitLabel(FunctionEndSym);
1694 // Set DwarfDwarfCompileUnitID in MCContext to default value.
1695 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1697 SmallPtrSet<const MDNode *, 16> ProcessedVars;
1698 collectVariableInfo(ProcessedVars);
1700 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1701 DwarfCompileUnit &TheCU = *SPMap.lookup(FnScope->getScopeNode());
1703 // Add the range of this function to the list of ranges for the CU.
1704 TheCU.addRange(RangeSpan(FunctionBeginSym, FunctionEndSym));
1706 // Under -gmlt, skip building the subprogram if there are no inlined
1707 // subroutines inside it.
1708 if (TheCU.getCUNode().getEmissionKind() == DIBuilder::LineTablesOnly &&
1709 LScopes.getAbstractScopesList().empty() && !IsDarwin) {
1710 assert(ScopeVariables.empty());
1711 assert(CurrentFnArguments.empty());
1712 assert(DbgValues.empty());
1713 assert(AbstractVariables.empty());
1714 LabelsBeforeInsn.clear();
1715 LabelsAfterInsn.clear();
1716 PrevLabel = nullptr;
1721 // Construct abstract scopes.
1722 for (LexicalScope *AScope : LScopes.getAbstractScopesList()) {
1723 DISubprogram SP(AScope->getScopeNode());
1724 assert(SP.isSubprogram());
1725 // Collect info for variables that were optimized out.
1726 DIArray Variables = SP.getVariables();
1727 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1728 DIVariable DV(Variables.getElement(i));
1729 assert(DV && DV.isVariable());
1730 if (!ProcessedVars.insert(DV))
1732 ensureAbstractVariableIsCreated(DV, DV.getContext());
1734 constructAbstractSubprogramScopeDIE(TheCU, AScope);
1737 constructSubprogramScopeDIE(TheCU, FnScope);
1740 // Ownership of DbgVariables is a bit subtle - ScopeVariables owns all the
1741 // DbgVariables except those that are also in AbstractVariables (since they
1742 // can be used cross-function)
1743 ScopeVariables.clear();
1744 CurrentFnArguments.clear();
1746 LabelsBeforeInsn.clear();
1747 LabelsAfterInsn.clear();
1748 PrevLabel = nullptr;
1752 // Register a source line with debug info. Returns the unique label that was
1753 // emitted and which provides correspondence to the source line list.
1754 void DwarfDebug::recordSourceLine(unsigned Line, unsigned Col, const MDNode *S,
1759 unsigned Discriminator = 0;
1760 if (DIScope Scope = DIScope(S)) {
1761 assert(Scope.isScope());
1762 Fn = Scope.getFilename();
1763 Dir = Scope.getDirectory();
1764 if (Scope.isLexicalBlockFile())
1765 Discriminator = DILexicalBlockFile(S).getDiscriminator();
1767 unsigned CUID = Asm->OutStreamer.getContext().getDwarfCompileUnitID();
1768 Src = static_cast<DwarfCompileUnit &>(*InfoHolder.getUnits()[CUID])
1769 .getOrCreateSourceID(Fn, Dir);
1771 Asm->OutStreamer.EmitDwarfLocDirective(Src, Line, Col, Flags, 0,
1775 //===----------------------------------------------------------------------===//
1777 //===----------------------------------------------------------------------===//
1779 // Emit initial Dwarf sections with a label at the start of each one.
1780 void DwarfDebug::emitSectionLabels() {
1781 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
1783 // Dwarf sections base addresses.
1784 DwarfInfoSectionSym =
1785 emitSectionSym(Asm, TLOF.getDwarfInfoSection(), "section_info");
1786 if (useSplitDwarf()) {
1787 DwarfInfoDWOSectionSym =
1788 emitSectionSym(Asm, TLOF.getDwarfInfoDWOSection(), "section_info_dwo");
1789 DwarfTypesDWOSectionSym =
1790 emitSectionSym(Asm, TLOF.getDwarfTypesDWOSection(), "section_types_dwo");
1792 DwarfAbbrevSectionSym =
1793 emitSectionSym(Asm, TLOF.getDwarfAbbrevSection(), "section_abbrev");
1794 if (useSplitDwarf())
1795 DwarfAbbrevDWOSectionSym = emitSectionSym(
1796 Asm, TLOF.getDwarfAbbrevDWOSection(), "section_abbrev_dwo");
1797 if (GenerateARangeSection)
1798 emitSectionSym(Asm, TLOF.getDwarfARangesSection());
1800 DwarfLineSectionSym =
1801 emitSectionSym(Asm, TLOF.getDwarfLineSection(), "section_line");
1802 if (GenerateGnuPubSections) {
1803 DwarfGnuPubNamesSectionSym =
1804 emitSectionSym(Asm, TLOF.getDwarfGnuPubNamesSection());
1805 DwarfGnuPubTypesSectionSym =
1806 emitSectionSym(Asm, TLOF.getDwarfGnuPubTypesSection());
1807 } else if (HasDwarfPubSections) {
1808 emitSectionSym(Asm, TLOF.getDwarfPubNamesSection());
1809 emitSectionSym(Asm, TLOF.getDwarfPubTypesSection());
1812 DwarfStrSectionSym =
1813 emitSectionSym(Asm, TLOF.getDwarfStrSection(), "info_string");
1814 if (useSplitDwarf()) {
1815 DwarfStrDWOSectionSym =
1816 emitSectionSym(Asm, TLOF.getDwarfStrDWOSection(), "skel_string");
1817 DwarfAddrSectionSym =
1818 emitSectionSym(Asm, TLOF.getDwarfAddrSection(), "addr_sec");
1819 DwarfDebugLocSectionSym =
1820 emitSectionSym(Asm, TLOF.getDwarfLocDWOSection(), "skel_loc");
1822 DwarfDebugLocSectionSym =
1823 emitSectionSym(Asm, TLOF.getDwarfLocSection(), "section_debug_loc");
1824 DwarfDebugRangeSectionSym =
1825 emitSectionSym(Asm, TLOF.getDwarfRangesSection(), "debug_range");
1828 // Recursively emits a debug information entry.
1829 void DwarfDebug::emitDIE(DIE &Die) {
1830 // Get the abbreviation for this DIE.
1831 const DIEAbbrev &Abbrev = Die.getAbbrev();
1833 // Emit the code (index) for the abbreviation.
1834 if (Asm->isVerbose())
1835 Asm->OutStreamer.AddComment("Abbrev [" + Twine(Abbrev.getNumber()) +
1836 "] 0x" + Twine::utohexstr(Die.getOffset()) +
1837 ":0x" + Twine::utohexstr(Die.getSize()) + " " +
1838 dwarf::TagString(Abbrev.getTag()));
1839 Asm->EmitULEB128(Abbrev.getNumber());
1841 const SmallVectorImpl<DIEValue *> &Values = Die.getValues();
1842 const SmallVectorImpl<DIEAbbrevData> &AbbrevData = Abbrev.getData();
1844 // Emit the DIE attribute values.
1845 for (unsigned i = 0, N = Values.size(); i < N; ++i) {
1846 dwarf::Attribute Attr = AbbrevData[i].getAttribute();
1847 dwarf::Form Form = AbbrevData[i].getForm();
1848 assert(Form && "Too many attributes for DIE (check abbreviation)");
1850 if (Asm->isVerbose()) {
1851 Asm->OutStreamer.AddComment(dwarf::AttributeString(Attr));
1852 if (Attr == dwarf::DW_AT_accessibility)
1853 Asm->OutStreamer.AddComment(dwarf::AccessibilityString(
1854 cast<DIEInteger>(Values[i])->getValue()));
1857 // Emit an attribute using the defined form.
1858 Values[i]->EmitValue(Asm, Form);
1861 // Emit the DIE children if any.
1862 if (Abbrev.hasChildren()) {
1863 for (auto &Child : Die.getChildren())
1866 Asm->OutStreamer.AddComment("End Of Children Mark");
1871 // Emit the debug info section.
1872 void DwarfDebug::emitDebugInfo() {
1873 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1875 Holder.emitUnits(this, DwarfAbbrevSectionSym);
1878 // Emit the abbreviation section.
1879 void DwarfDebug::emitAbbreviations() {
1880 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1882 Holder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevSection());
1885 // Emit the last address of the section and the end of the line matrix.
1886 void DwarfDebug::emitEndOfLineMatrix(unsigned SectionEnd) {
1887 // Define last address of section.
1888 Asm->OutStreamer.AddComment("Extended Op");
1891 Asm->OutStreamer.AddComment("Op size");
1892 Asm->EmitInt8(Asm->getDataLayout().getPointerSize() + 1);
1893 Asm->OutStreamer.AddComment("DW_LNE_set_address");
1894 Asm->EmitInt8(dwarf::DW_LNE_set_address);
1896 Asm->OutStreamer.AddComment("Section end label");
1898 Asm->OutStreamer.EmitSymbolValue(
1899 Asm->GetTempSymbol("section_end", SectionEnd),
1900 Asm->getDataLayout().getPointerSize());
1902 // Mark end of matrix.
1903 Asm->OutStreamer.AddComment("DW_LNE_end_sequence");
1909 void DwarfDebug::emitAccel(DwarfAccelTable &Accel, const MCSection *Section,
1910 StringRef TableName, StringRef SymName) {
1911 Accel.FinalizeTable(Asm, TableName);
1912 Asm->OutStreamer.SwitchSection(Section);
1913 auto *SectionBegin = Asm->GetTempSymbol(SymName);
1914 Asm->OutStreamer.EmitLabel(SectionBegin);
1916 // Emit the full data.
1917 Accel.Emit(Asm, SectionBegin, &InfoHolder, DwarfStrSectionSym);
1920 // Emit visible names into a hashed accelerator table section.
1921 void DwarfDebug::emitAccelNames() {
1922 emitAccel(AccelNames, Asm->getObjFileLowering().getDwarfAccelNamesSection(),
1923 "Names", "names_begin");
1926 // Emit objective C classes and categories into a hashed accelerator table
1928 void DwarfDebug::emitAccelObjC() {
1929 emitAccel(AccelObjC, Asm->getObjFileLowering().getDwarfAccelObjCSection(),
1930 "ObjC", "objc_begin");
1933 // Emit namespace dies into a hashed accelerator table.
1934 void DwarfDebug::emitAccelNamespaces() {
1935 emitAccel(AccelNamespace,
1936 Asm->getObjFileLowering().getDwarfAccelNamespaceSection(),
1937 "namespac", "namespac_begin");
1940 // Emit type dies into a hashed accelerator table.
1941 void DwarfDebug::emitAccelTypes() {
1942 emitAccel(AccelTypes, Asm->getObjFileLowering().getDwarfAccelTypesSection(),
1943 "types", "types_begin");
1946 // Public name handling.
1947 // The format for the various pubnames:
1949 // dwarf pubnames - offset/name pairs where the offset is the offset into the CU
1950 // for the DIE that is named.
1952 // gnu pubnames - offset/index value/name tuples where the offset is the offset
1953 // into the CU and the index value is computed according to the type of value
1954 // for the DIE that is named.
1956 // For type units the offset is the offset of the skeleton DIE. For split dwarf
1957 // it's the offset within the debug_info/debug_types dwo section, however, the
1958 // reference in the pubname header doesn't change.
1960 /// computeIndexValue - Compute the gdb index value for the DIE and CU.
1961 static dwarf::PubIndexEntryDescriptor computeIndexValue(DwarfUnit *CU,
1963 dwarf::GDBIndexEntryLinkage Linkage = dwarf::GIEL_STATIC;
1965 // We could have a specification DIE that has our most of our knowledge,
1966 // look for that now.
1967 DIEValue *SpecVal = Die->findAttribute(dwarf::DW_AT_specification);
1969 DIE &SpecDIE = cast<DIEEntry>(SpecVal)->getEntry();
1970 if (SpecDIE.findAttribute(dwarf::DW_AT_external))
1971 Linkage = dwarf::GIEL_EXTERNAL;
1972 } else if (Die->findAttribute(dwarf::DW_AT_external))
1973 Linkage = dwarf::GIEL_EXTERNAL;
1975 switch (Die->getTag()) {
1976 case dwarf::DW_TAG_class_type:
1977 case dwarf::DW_TAG_structure_type:
1978 case dwarf::DW_TAG_union_type:
1979 case dwarf::DW_TAG_enumeration_type:
1980 return dwarf::PubIndexEntryDescriptor(
1981 dwarf::GIEK_TYPE, CU->getLanguage() != dwarf::DW_LANG_C_plus_plus
1982 ? dwarf::GIEL_STATIC
1983 : dwarf::GIEL_EXTERNAL);
1984 case dwarf::DW_TAG_typedef:
1985 case dwarf::DW_TAG_base_type:
1986 case dwarf::DW_TAG_subrange_type:
1987 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_TYPE, dwarf::GIEL_STATIC);
1988 case dwarf::DW_TAG_namespace:
1989 return dwarf::GIEK_TYPE;
1990 case dwarf::DW_TAG_subprogram:
1991 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_FUNCTION, Linkage);
1992 case dwarf::DW_TAG_constant:
1993 case dwarf::DW_TAG_variable:
1994 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE, Linkage);
1995 case dwarf::DW_TAG_enumerator:
1996 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE,
1997 dwarf::GIEL_STATIC);
1999 return dwarf::GIEK_NONE;
2003 /// emitDebugPubNames - Emit visible names into a debug pubnames section.
2005 void DwarfDebug::emitDebugPubNames(bool GnuStyle) {
2006 const MCSection *PSec =
2007 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubNamesSection()
2008 : Asm->getObjFileLowering().getDwarfPubNamesSection();
2010 emitDebugPubSection(GnuStyle, PSec, "Names", &DwarfUnit::getGlobalNames);
2013 void DwarfDebug::emitDebugPubSection(
2014 bool GnuStyle, const MCSection *PSec, StringRef Name,
2015 const StringMap<const DIE *> &(DwarfUnit::*Accessor)() const) {
2016 for (const auto &NU : CUMap) {
2017 DwarfCompileUnit *TheU = NU.second;
2019 const auto &Globals = (TheU->*Accessor)();
2021 if (Globals.empty())
2024 if (auto Skeleton = static_cast<DwarfCompileUnit *>(TheU->getSkeleton()))
2026 unsigned ID = TheU->getUniqueID();
2028 // Start the dwarf pubnames section.
2029 Asm->OutStreamer.SwitchSection(PSec);
2032 Asm->OutStreamer.AddComment("Length of Public " + Name + " Info");
2033 MCSymbol *BeginLabel = Asm->GetTempSymbol("pub" + Name + "_begin", ID);
2034 MCSymbol *EndLabel = Asm->GetTempSymbol("pub" + Name + "_end", ID);
2035 Asm->EmitLabelDifference(EndLabel, BeginLabel, 4);
2037 Asm->OutStreamer.EmitLabel(BeginLabel);
2039 Asm->OutStreamer.AddComment("DWARF Version");
2040 Asm->EmitInt16(dwarf::DW_PUBNAMES_VERSION);
2042 Asm->OutStreamer.AddComment("Offset of Compilation Unit Info");
2043 Asm->EmitSectionOffset(TheU->getLabelBegin(), TheU->getSectionSym());
2045 Asm->OutStreamer.AddComment("Compilation Unit Length");
2046 Asm->EmitLabelDifference(TheU->getLabelEnd(), TheU->getLabelBegin(), 4);
2048 // Emit the pubnames for this compilation unit.
2049 for (const auto &GI : Globals) {
2050 const char *Name = GI.getKeyData();
2051 const DIE *Entity = GI.second;
2053 Asm->OutStreamer.AddComment("DIE offset");
2054 Asm->EmitInt32(Entity->getOffset());
2057 dwarf::PubIndexEntryDescriptor Desc = computeIndexValue(TheU, Entity);
2058 Asm->OutStreamer.AddComment(
2059 Twine("Kind: ") + dwarf::GDBIndexEntryKindString(Desc.Kind) + ", " +
2060 dwarf::GDBIndexEntryLinkageString(Desc.Linkage));
2061 Asm->EmitInt8(Desc.toBits());
2064 Asm->OutStreamer.AddComment("External Name");
2065 Asm->OutStreamer.EmitBytes(StringRef(Name, GI.getKeyLength() + 1));
2068 Asm->OutStreamer.AddComment("End Mark");
2070 Asm->OutStreamer.EmitLabel(EndLabel);
2074 void DwarfDebug::emitDebugPubTypes(bool GnuStyle) {
2075 const MCSection *PSec =
2076 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubTypesSection()
2077 : Asm->getObjFileLowering().getDwarfPubTypesSection();
2079 emitDebugPubSection(GnuStyle, PSec, "Types", &DwarfUnit::getGlobalTypes);
2082 // Emit visible names into a debug str section.
2083 void DwarfDebug::emitDebugStr() {
2084 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
2085 Holder.emitStrings(Asm->getObjFileLowering().getDwarfStrSection());
2088 /// Emits an optimal (=sorted) sequence of DW_OP_pieces.
2089 void DwarfDebug::emitLocPieces(ByteStreamer &Streamer,
2090 const DITypeIdentifierMap &Map,
2091 ArrayRef<DebugLocEntry::Value> Values) {
2092 assert(std::all_of(Values.begin(), Values.end(), [](DebugLocEntry::Value P) {
2093 return P.isVariablePiece();
2094 }) && "all values are expected to be pieces");
2095 assert(std::is_sorted(Values.begin(), Values.end()) &&
2096 "pieces are expected to be sorted");
2098 unsigned Offset = 0;
2099 for (auto Piece : Values) {
2100 DIExpression Expr = Piece.getExpression();
2101 unsigned PieceOffset = Expr.getPieceOffset();
2102 unsigned PieceSize = Expr.getPieceSize();
2103 assert(Offset <= PieceOffset && "overlapping or duplicate pieces");
2104 if (Offset < PieceOffset) {
2105 // The DWARF spec seriously mandates pieces with no locations for gaps.
2106 Asm->EmitDwarfOpPiece(Streamer, (PieceOffset-Offset)*8);
2107 Offset += PieceOffset-Offset;
2110 Offset += PieceSize;
2112 const unsigned SizeOfByte = 8;
2114 DIVariable Var = Piece.getVariable();
2115 assert(!Var.isIndirect() && "indirect address for piece");
2116 unsigned VarSize = Var.getSizeInBits(Map);
2117 assert(PieceSize+PieceOffset <= VarSize/SizeOfByte
2118 && "piece is larger than or outside of variable");
2119 assert(PieceSize*SizeOfByte != VarSize
2120 && "piece covers entire variable");
2122 if (Piece.isLocation() && Piece.getLoc().isReg())
2123 Asm->EmitDwarfRegOpPiece(Streamer,
2125 PieceSize*SizeOfByte);
2127 emitDebugLocValue(Streamer, Piece);
2128 Asm->EmitDwarfOpPiece(Streamer, PieceSize*SizeOfByte);
2134 void DwarfDebug::emitDebugLocEntry(ByteStreamer &Streamer,
2135 const DebugLocEntry &Entry) {
2136 const DebugLocEntry::Value Value = Entry.getValues()[0];
2137 if (Value.isVariablePiece())
2138 // Emit all pieces that belong to the same variable and range.
2139 return emitLocPieces(Streamer, TypeIdentifierMap, Entry.getValues());
2141 assert(Entry.getValues().size() == 1 && "only pieces may have >1 value");
2142 emitDebugLocValue(Streamer, Value);
2145 void DwarfDebug::emitDebugLocValue(ByteStreamer &Streamer,
2146 const DebugLocEntry::Value &Value) {
2147 DIVariable DV = Value.getVariable();
2149 if (Value.isInt()) {
2150 DIBasicType BTy(resolve(DV.getType()));
2151 if (BTy.Verify() && (BTy.getEncoding() == dwarf::DW_ATE_signed ||
2152 BTy.getEncoding() == dwarf::DW_ATE_signed_char)) {
2153 Streamer.EmitInt8(dwarf::DW_OP_consts, "DW_OP_consts");
2154 Streamer.EmitSLEB128(Value.getInt());
2156 Streamer.EmitInt8(dwarf::DW_OP_constu, "DW_OP_constu");
2157 Streamer.EmitULEB128(Value.getInt());
2159 } else if (Value.isLocation()) {
2160 MachineLocation Loc = Value.getLoc();
2161 DIExpression Expr = Value.getExpression();
2164 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2166 // Complex address entry.
2167 unsigned N = Expr.getNumElements();
2169 if (N >= 2 && Expr.getElement(0) == dwarf::DW_OP_plus) {
2170 if (Loc.getOffset()) {
2172 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2173 Streamer.EmitInt8(dwarf::DW_OP_deref, "DW_OP_deref");
2174 Streamer.EmitInt8(dwarf::DW_OP_plus_uconst, "DW_OP_plus_uconst");
2175 Streamer.EmitSLEB128(Expr.getElement(1));
2177 // If first address element is OpPlus then emit
2178 // DW_OP_breg + Offset instead of DW_OP_reg + Offset.
2179 MachineLocation TLoc(Loc.getReg(), Expr.getElement(1));
2180 Asm->EmitDwarfRegOp(Streamer, TLoc, DV.isIndirect());
2184 Asm->EmitDwarfRegOp(Streamer, Loc, DV.isIndirect());
2187 // Emit remaining complex address elements.
2188 for (; i < N; ++i) {
2189 uint64_t Element = Expr.getElement(i);
2190 if (Element == dwarf::DW_OP_plus) {
2191 Streamer.EmitInt8(dwarf::DW_OP_plus_uconst, "DW_OP_plus_uconst");
2192 Streamer.EmitULEB128(Expr.getElement(++i));
2193 } else if (Element == dwarf::DW_OP_deref) {
2195 Streamer.EmitInt8(dwarf::DW_OP_deref, "DW_OP_deref");
2196 } else if (Element == dwarf::DW_OP_piece) {
2198 // handled in emitDebugLocEntry.
2200 llvm_unreachable("unknown Opcode found in complex address");
2204 // else ... ignore constant fp. There is not any good way to
2205 // to represent them here in dwarf.
2209 void DwarfDebug::emitDebugLocEntryLocation(const DebugLocEntry &Entry) {
2210 Asm->OutStreamer.AddComment("Loc expr size");
2211 MCSymbol *begin = Asm->OutStreamer.getContext().CreateTempSymbol();
2212 MCSymbol *end = Asm->OutStreamer.getContext().CreateTempSymbol();
2213 Asm->EmitLabelDifference(end, begin, 2);
2214 Asm->OutStreamer.EmitLabel(begin);
2216 APByteStreamer Streamer(*Asm);
2217 emitDebugLocEntry(Streamer, Entry);
2219 Asm->OutStreamer.EmitLabel(end);
2222 // Emit locations into the debug loc section.
2223 void DwarfDebug::emitDebugLoc() {
2224 // Start the dwarf loc section.
2225 Asm->OutStreamer.SwitchSection(
2226 Asm->getObjFileLowering().getDwarfLocSection());
2227 unsigned char Size = Asm->getDataLayout().getPointerSize();
2228 for (const auto &DebugLoc : DotDebugLocEntries) {
2229 Asm->OutStreamer.EmitLabel(DebugLoc.Label);
2230 const DwarfCompileUnit *CU = DebugLoc.CU;
2231 assert(!CU->getRanges().empty());
2232 for (const auto &Entry : DebugLoc.List) {
2233 // Set up the range. This range is relative to the entry point of the
2234 // compile unit. This is a hard coded 0 for low_pc when we're emitting
2235 // ranges, or the DW_AT_low_pc on the compile unit otherwise.
2236 if (CU->getRanges().size() == 1) {
2237 // Grab the begin symbol from the first range as our base.
2238 const MCSymbol *Base = CU->getRanges()[0].getStart();
2239 Asm->EmitLabelDifference(Entry.getBeginSym(), Base, Size);
2240 Asm->EmitLabelDifference(Entry.getEndSym(), Base, Size);
2242 Asm->OutStreamer.EmitSymbolValue(Entry.getBeginSym(), Size);
2243 Asm->OutStreamer.EmitSymbolValue(Entry.getEndSym(), Size);
2246 emitDebugLocEntryLocation(Entry);
2248 Asm->OutStreamer.EmitIntValue(0, Size);
2249 Asm->OutStreamer.EmitIntValue(0, Size);
2253 void DwarfDebug::emitDebugLocDWO() {
2254 Asm->OutStreamer.SwitchSection(
2255 Asm->getObjFileLowering().getDwarfLocDWOSection());
2256 for (const auto &DebugLoc : DotDebugLocEntries) {
2257 Asm->OutStreamer.EmitLabel(DebugLoc.Label);
2258 for (const auto &Entry : DebugLoc.List) {
2259 // Just always use start_length for now - at least that's one address
2260 // rather than two. We could get fancier and try to, say, reuse an
2261 // address we know we've emitted elsewhere (the start of the function?
2262 // The start of the CU or CU subrange that encloses this range?)
2263 Asm->EmitInt8(dwarf::DW_LLE_start_length_entry);
2264 unsigned idx = AddrPool.getIndex(Entry.getBeginSym());
2265 Asm->EmitULEB128(idx);
2266 Asm->EmitLabelDifference(Entry.getEndSym(), Entry.getBeginSym(), 4);
2268 emitDebugLocEntryLocation(Entry);
2270 Asm->EmitInt8(dwarf::DW_LLE_end_of_list_entry);
2275 const MCSymbol *Start, *End;
2278 // Emit a debug aranges section, containing a CU lookup for any
2279 // address we can tie back to a CU.
2280 void DwarfDebug::emitDebugARanges() {
2281 // Start the dwarf aranges section.
2282 Asm->OutStreamer.SwitchSection(
2283 Asm->getObjFileLowering().getDwarfARangesSection());
2285 typedef DenseMap<DwarfCompileUnit *, std::vector<ArangeSpan>> SpansType;
2289 // Build a list of sections used.
2290 std::vector<const MCSection *> Sections;
2291 for (const auto &it : SectionMap) {
2292 const MCSection *Section = it.first;
2293 Sections.push_back(Section);
2296 // Sort the sections into order.
2297 // This is only done to ensure consistent output order across different runs.
2298 std::sort(Sections.begin(), Sections.end(), SectionSort);
2300 // Build a set of address spans, sorted by CU.
2301 for (const MCSection *Section : Sections) {
2302 SmallVector<SymbolCU, 8> &List = SectionMap[Section];
2303 if (List.size() < 2)
2306 // Sort the symbols by offset within the section.
2307 std::sort(List.begin(), List.end(),
2308 [&](const SymbolCU &A, const SymbolCU &B) {
2309 unsigned IA = A.Sym ? Asm->OutStreamer.GetSymbolOrder(A.Sym) : 0;
2310 unsigned IB = B.Sym ? Asm->OutStreamer.GetSymbolOrder(B.Sym) : 0;
2312 // Symbols with no order assigned should be placed at the end.
2313 // (e.g. section end labels)
2321 // If we have no section (e.g. common), just write out
2322 // individual spans for each symbol.
2324 for (const SymbolCU &Cur : List) {
2326 Span.Start = Cur.Sym;
2329 Spans[Cur.CU].push_back(Span);
2332 // Build spans between each label.
2333 const MCSymbol *StartSym = List[0].Sym;
2334 for (size_t n = 1, e = List.size(); n < e; n++) {
2335 const SymbolCU &Prev = List[n - 1];
2336 const SymbolCU &Cur = List[n];
2338 // Try and build the longest span we can within the same CU.
2339 if (Cur.CU != Prev.CU) {
2341 Span.Start = StartSym;
2343 Spans[Prev.CU].push_back(Span);
2350 unsigned PtrSize = Asm->getDataLayout().getPointerSize();
2352 // Build a list of CUs used.
2353 std::vector<DwarfCompileUnit *> CUs;
2354 for (const auto &it : Spans) {
2355 DwarfCompileUnit *CU = it.first;
2359 // Sort the CU list (again, to ensure consistent output order).
2360 std::sort(CUs.begin(), CUs.end(), [](const DwarfUnit *A, const DwarfUnit *B) {
2361 return A->getUniqueID() < B->getUniqueID();
2364 // Emit an arange table for each CU we used.
2365 for (DwarfCompileUnit *CU : CUs) {
2366 std::vector<ArangeSpan> &List = Spans[CU];
2368 // Emit size of content not including length itself.
2369 unsigned ContentSize =
2370 sizeof(int16_t) + // DWARF ARange version number
2371 sizeof(int32_t) + // Offset of CU in the .debug_info section
2372 sizeof(int8_t) + // Pointer Size (in bytes)
2373 sizeof(int8_t); // Segment Size (in bytes)
2375 unsigned TupleSize = PtrSize * 2;
2377 // 7.20 in the Dwarf specs requires the table to be aligned to a tuple.
2379 OffsetToAlignment(sizeof(int32_t) + ContentSize, TupleSize);
2381 ContentSize += Padding;
2382 ContentSize += (List.size() + 1) * TupleSize;
2384 // For each compile unit, write the list of spans it covers.
2385 Asm->OutStreamer.AddComment("Length of ARange Set");
2386 Asm->EmitInt32(ContentSize);
2387 Asm->OutStreamer.AddComment("DWARF Arange version number");
2388 Asm->EmitInt16(dwarf::DW_ARANGES_VERSION);
2389 Asm->OutStreamer.AddComment("Offset Into Debug Info Section");
2390 Asm->EmitSectionOffset(CU->getLocalLabelBegin(), CU->getLocalSectionSym());
2391 Asm->OutStreamer.AddComment("Address Size (in bytes)");
2392 Asm->EmitInt8(PtrSize);
2393 Asm->OutStreamer.AddComment("Segment Size (in bytes)");
2396 Asm->OutStreamer.EmitFill(Padding, 0xff);
2398 for (const ArangeSpan &Span : List) {
2399 Asm->EmitLabelReference(Span.Start, PtrSize);
2401 // Calculate the size as being from the span start to it's end.
2403 Asm->EmitLabelDifference(Span.End, Span.Start, PtrSize);
2405 // For symbols without an end marker (e.g. common), we
2406 // write a single arange entry containing just that one symbol.
2407 uint64_t Size = SymSize[Span.Start];
2411 Asm->OutStreamer.EmitIntValue(Size, PtrSize);
2415 Asm->OutStreamer.AddComment("ARange terminator");
2416 Asm->OutStreamer.EmitIntValue(0, PtrSize);
2417 Asm->OutStreamer.EmitIntValue(0, PtrSize);
2421 // Emit visible names into a debug ranges section.
2422 void DwarfDebug::emitDebugRanges() {
2423 // Start the dwarf ranges section.
2424 Asm->OutStreamer.SwitchSection(
2425 Asm->getObjFileLowering().getDwarfRangesSection());
2427 // Size for our labels.
2428 unsigned char Size = Asm->getDataLayout().getPointerSize();
2430 // Grab the specific ranges for the compile units in the module.
2431 for (const auto &I : CUMap) {
2432 DwarfCompileUnit *TheCU = I.second;
2434 // Iterate over the misc ranges for the compile units in the module.
2435 for (const RangeSpanList &List : TheCU->getRangeLists()) {
2436 // Emit our symbol so we can find the beginning of the range.
2437 Asm->OutStreamer.EmitLabel(List.getSym());
2439 for (const RangeSpan &Range : List.getRanges()) {
2440 const MCSymbol *Begin = Range.getStart();
2441 const MCSymbol *End = Range.getEnd();
2442 assert(Begin && "Range without a begin symbol?");
2443 assert(End && "Range without an end symbol?");
2444 if (TheCU->getRanges().size() == 1) {
2445 // Grab the begin symbol from the first range as our base.
2446 const MCSymbol *Base = TheCU->getRanges()[0].getStart();
2447 Asm->EmitLabelDifference(Begin, Base, Size);
2448 Asm->EmitLabelDifference(End, Base, Size);
2450 Asm->OutStreamer.EmitSymbolValue(Begin, Size);
2451 Asm->OutStreamer.EmitSymbolValue(End, Size);
2455 // And terminate the list with two 0 values.
2456 Asm->OutStreamer.EmitIntValue(0, Size);
2457 Asm->OutStreamer.EmitIntValue(0, Size);
2460 // Now emit a range for the CU itself.
2461 if (TheCU->getRanges().size() > 1) {
2462 Asm->OutStreamer.EmitLabel(
2463 Asm->GetTempSymbol("cu_ranges", TheCU->getUniqueID()));
2464 for (const RangeSpan &Range : TheCU->getRanges()) {
2465 const MCSymbol *Begin = Range.getStart();
2466 const MCSymbol *End = Range.getEnd();
2467 assert(Begin && "Range without a begin symbol?");
2468 assert(End && "Range without an end symbol?");
2469 Asm->OutStreamer.EmitSymbolValue(Begin, Size);
2470 Asm->OutStreamer.EmitSymbolValue(End, Size);
2472 // And terminate the list with two 0 values.
2473 Asm->OutStreamer.EmitIntValue(0, Size);
2474 Asm->OutStreamer.EmitIntValue(0, Size);
2479 // DWARF5 Experimental Separate Dwarf emitters.
2481 void DwarfDebug::initSkeletonUnit(const DwarfUnit &U, DIE &Die,
2482 std::unique_ptr<DwarfUnit> NewU) {
2483 NewU->addLocalString(Die, dwarf::DW_AT_GNU_dwo_name,
2484 U.getCUNode().getSplitDebugFilename());
2486 if (!CompilationDir.empty())
2487 NewU->addLocalString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
2489 addGnuPubAttributes(*NewU, Die);
2491 SkeletonHolder.addUnit(std::move(NewU));
2494 // This DIE has the following attributes: DW_AT_comp_dir, DW_AT_stmt_list,
2495 // DW_AT_low_pc, DW_AT_high_pc, DW_AT_ranges, DW_AT_dwo_name, DW_AT_dwo_id,
2496 // DW_AT_addr_base, DW_AT_ranges_base.
2497 DwarfCompileUnit &DwarfDebug::constructSkeletonCU(const DwarfCompileUnit &CU) {
2499 auto OwnedUnit = make_unique<DwarfCompileUnit>(
2500 CU.getUniqueID(), CU.getCUNode(), Asm, this, &SkeletonHolder);
2501 DwarfCompileUnit &NewCU = *OwnedUnit;
2502 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoSection(),
2503 DwarfInfoSectionSym);
2505 NewCU.initStmtList(DwarfLineSectionSym);
2507 initSkeletonUnit(CU, NewCU.getUnitDie(), std::move(OwnedUnit));
2512 // Emit the .debug_info.dwo section for separated dwarf. This contains the
2513 // compile units that would normally be in debug_info.
2514 void DwarfDebug::emitDebugInfoDWO() {
2515 assert(useSplitDwarf() && "No split dwarf debug info?");
2516 // Don't pass an abbrev symbol, using a constant zero instead so as not to
2517 // emit relocations into the dwo file.
2518 InfoHolder.emitUnits(this, /* AbbrevSymbol */ nullptr);
2521 // Emit the .debug_abbrev.dwo section for separated dwarf. This contains the
2522 // abbreviations for the .debug_info.dwo section.
2523 void DwarfDebug::emitDebugAbbrevDWO() {
2524 assert(useSplitDwarf() && "No split dwarf?");
2525 InfoHolder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevDWOSection());
2528 void DwarfDebug::emitDebugLineDWO() {
2529 assert(useSplitDwarf() && "No split dwarf?");
2530 Asm->OutStreamer.SwitchSection(
2531 Asm->getObjFileLowering().getDwarfLineDWOSection());
2532 SplitTypeUnitFileTable.Emit(Asm->OutStreamer);
2535 // Emit the .debug_str.dwo section for separated dwarf. This contains the
2536 // string section and is identical in format to traditional .debug_str
2538 void DwarfDebug::emitDebugStrDWO() {
2539 assert(useSplitDwarf() && "No split dwarf?");
2540 const MCSection *OffSec =
2541 Asm->getObjFileLowering().getDwarfStrOffDWOSection();
2542 InfoHolder.emitStrings(Asm->getObjFileLowering().getDwarfStrDWOSection(),
2546 MCDwarfDwoLineTable *DwarfDebug::getDwoLineTable(const DwarfCompileUnit &CU) {
2547 if (!useSplitDwarf())
2550 SplitTypeUnitFileTable.setCompilationDir(CU.getCUNode().getDirectory());
2551 return &SplitTypeUnitFileTable;
2554 static uint64_t makeTypeSignature(StringRef Identifier) {
2556 Hash.update(Identifier);
2557 // ... take the least significant 8 bytes and return those. Our MD5
2558 // implementation always returns its results in little endian, swap bytes
2560 MD5::MD5Result Result;
2562 return *reinterpret_cast<support::ulittle64_t *>(Result + 8);
2565 void DwarfDebug::addDwarfTypeUnitType(DwarfCompileUnit &CU,
2566 StringRef Identifier, DIE &RefDie,
2567 DICompositeType CTy) {
2568 // Fast path if we're building some type units and one has already used the
2569 // address pool we know we're going to throw away all this work anyway, so
2570 // don't bother building dependent types.
2571 if (!TypeUnitsUnderConstruction.empty() && AddrPool.hasBeenUsed())
2574 const DwarfTypeUnit *&TU = DwarfTypeUnits[CTy];
2576 CU.addDIETypeSignature(RefDie, *TU);
2580 bool TopLevelType = TypeUnitsUnderConstruction.empty();
2581 AddrPool.resetUsedFlag();
2583 auto OwnedUnit = make_unique<DwarfTypeUnit>(
2584 InfoHolder.getUnits().size() + TypeUnitsUnderConstruction.size(), CU, Asm,
2585 this, &InfoHolder, getDwoLineTable(CU));
2586 DwarfTypeUnit &NewTU = *OwnedUnit;
2587 DIE &UnitDie = NewTU.getUnitDie();
2589 TypeUnitsUnderConstruction.push_back(
2590 std::make_pair(std::move(OwnedUnit), CTy));
2592 NewTU.addUInt(UnitDie, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
2595 uint64_t Signature = makeTypeSignature(Identifier);
2596 NewTU.setTypeSignature(Signature);
2598 if (useSplitDwarf())
2599 NewTU.initSection(Asm->getObjFileLowering().getDwarfTypesDWOSection(),
2600 DwarfTypesDWOSectionSym);
2602 CU.applyStmtList(UnitDie);
2604 Asm->getObjFileLowering().getDwarfTypesSection(Signature));
2607 NewTU.setType(NewTU.createTypeDIE(CTy));
2610 auto TypeUnitsToAdd = std::move(TypeUnitsUnderConstruction);
2611 TypeUnitsUnderConstruction.clear();
2613 // Types referencing entries in the address table cannot be placed in type
2615 if (AddrPool.hasBeenUsed()) {
2617 // Remove all the types built while building this type.
2618 // This is pessimistic as some of these types might not be dependent on
2619 // the type that used an address.
2620 for (const auto &TU : TypeUnitsToAdd)
2621 DwarfTypeUnits.erase(TU.second);
2623 // Construct this type in the CU directly.
2624 // This is inefficient because all the dependent types will be rebuilt
2625 // from scratch, including building them in type units, discovering that
2626 // they depend on addresses, throwing them out and rebuilding them.
2627 CU.constructTypeDIE(RefDie, CTy);
2631 // If the type wasn't dependent on fission addresses, finish adding the type
2632 // and all its dependent types.
2633 for (auto &TU : TypeUnitsToAdd)
2634 InfoHolder.addUnit(std::move(TU.first));
2636 CU.addDIETypeSignature(RefDie, NewTU);
2639 void DwarfDebug::attachLowHighPC(DwarfCompileUnit &Unit, DIE &D,
2640 const MCSymbol *Begin, const MCSymbol *End) {
2641 assert(Begin && "Begin label should not be null!");
2642 assert(End && "End label should not be null!");
2643 assert(Begin->isDefined() && "Invalid starting label");
2644 assert(End->isDefined() && "Invalid end label");
2646 Unit.addLabelAddress(D, dwarf::DW_AT_low_pc, Begin);
2647 if (DwarfVersion < 4)
2648 Unit.addLabelAddress(D, dwarf::DW_AT_high_pc, End);
2650 Unit.addLabelDelta(D, dwarf::DW_AT_high_pc, End, Begin);
2653 // Accelerator table mutators - add each name along with its companion
2654 // DIE to the proper table while ensuring that the name that we're going
2655 // to reference is in the string table. We do this since the names we
2656 // add may not only be identical to the names in the DIE.
2657 void DwarfDebug::addAccelName(StringRef Name, const DIE &Die) {
2658 if (!useDwarfAccelTables())
2660 AccelNames.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2664 void DwarfDebug::addAccelObjC(StringRef Name, const DIE &Die) {
2665 if (!useDwarfAccelTables())
2667 AccelObjC.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2671 void DwarfDebug::addAccelNamespace(StringRef Name, const DIE &Die) {
2672 if (!useDwarfAccelTables())
2674 AccelNamespace.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2678 void DwarfDebug::addAccelType(StringRef Name, const DIE &Die, char Flags) {
2679 if (!useDwarfAccelTables())
2681 AccelTypes.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),