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"
15 #include "ByteStreamer.h"
17 #include "DebugLocEntry.h"
18 #include "DwarfCompileUnit.h"
19 #include "DwarfExpression.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/DIE.h"
26 #include "llvm/CodeGen/MachineFunction.h"
27 #include "llvm/CodeGen/MachineModuleInfo.h"
28 #include "llvm/IR/Constants.h"
29 #include "llvm/IR/DIBuilder.h"
30 #include "llvm/IR/DataLayout.h"
31 #include "llvm/IR/DebugInfo.h"
32 #include "llvm/IR/Instructions.h"
33 #include "llvm/IR/Module.h"
34 #include "llvm/IR/ValueHandle.h"
35 #include "llvm/MC/MCAsmInfo.h"
36 #include "llvm/MC/MCSection.h"
37 #include "llvm/MC/MCStreamer.h"
38 #include "llvm/MC/MCSymbol.h"
39 #include "llvm/Support/CommandLine.h"
40 #include "llvm/Support/Debug.h"
41 #include "llvm/Support/Dwarf.h"
42 #include "llvm/Support/Endian.h"
43 #include "llvm/Support/ErrorHandling.h"
44 #include "llvm/Support/FormattedStream.h"
45 #include "llvm/Support/LEB128.h"
46 #include "llvm/Support/MD5.h"
47 #include "llvm/Support/Path.h"
48 #include "llvm/Support/Timer.h"
49 #include "llvm/Support/raw_ostream.h"
50 #include "llvm/Target/TargetFrameLowering.h"
51 #include "llvm/Target/TargetLoweringObjectFile.h"
52 #include "llvm/Target/TargetMachine.h"
53 #include "llvm/Target/TargetOptions.h"
54 #include "llvm/Target/TargetRegisterInfo.h"
55 #include "llvm/Target/TargetSubtargetInfo.h"
58 #define DEBUG_TYPE "dwarfdebug"
61 DisableDebugInfoPrinting("disable-debug-info-print", cl::Hidden,
62 cl::desc("Disable debug info printing"));
64 static cl::opt<bool> UnknownLocations(
65 "use-unknown-locations", cl::Hidden,
66 cl::desc("Make an absence of debug location information explicit."),
70 GenerateGnuPubSections("generate-gnu-dwarf-pub-sections", cl::Hidden,
71 cl::desc("Generate GNU-style pubnames and pubtypes"),
74 static cl::opt<bool> GenerateARangeSection("generate-arange-section",
76 cl::desc("Generate dwarf aranges"),
80 enum DefaultOnOff { Default, Enable, Disable };
83 static cl::opt<DefaultOnOff>
84 DwarfAccelTables("dwarf-accel-tables", cl::Hidden,
85 cl::desc("Output prototype dwarf accelerator tables."),
86 cl::values(clEnumVal(Default, "Default for platform"),
87 clEnumVal(Enable, "Enabled"),
88 clEnumVal(Disable, "Disabled"), clEnumValEnd),
91 static cl::opt<DefaultOnOff>
92 SplitDwarf("split-dwarf", cl::Hidden,
93 cl::desc("Output DWARF5 split debug info."),
94 cl::values(clEnumVal(Default, "Default for platform"),
95 clEnumVal(Enable, "Enabled"),
96 clEnumVal(Disable, "Disabled"), clEnumValEnd),
99 static cl::opt<DefaultOnOff>
100 DwarfPubSections("generate-dwarf-pub-sections", cl::Hidden,
101 cl::desc("Generate DWARF pubnames and pubtypes sections"),
102 cl::values(clEnumVal(Default, "Default for platform"),
103 clEnumVal(Enable, "Enabled"),
104 clEnumVal(Disable, "Disabled"), clEnumValEnd),
107 static const char *const DWARFGroupName = "DWARF Emission";
108 static const char *const DbgTimerName = "DWARF Debug Writer";
110 void DebugLocDwarfExpression::EmitOp(uint8_t Op, const char *Comment) {
112 Op, Comment ? Twine(Comment) + " " + dwarf::OperationEncodingString(Op)
113 : dwarf::OperationEncodingString(Op));
116 void DebugLocDwarfExpression::EmitSigned(int64_t Value) {
117 BS.EmitSLEB128(Value, Twine(Value));
120 void DebugLocDwarfExpression::EmitUnsigned(uint64_t Value) {
121 BS.EmitULEB128(Value, Twine(Value));
124 bool DebugLocDwarfExpression::isFrameRegister(unsigned MachineReg) {
125 // This information is not available while emitting .debug_loc entries.
129 //===----------------------------------------------------------------------===//
131 /// resolve - Look in the DwarfDebug map for the MDNode that
132 /// corresponds to the reference.
133 template <typename T> T *DbgVariable::resolve(TypedDebugNodeRef<T> Ref) const {
134 return DD->resolve(Ref);
137 bool DbgVariable::isBlockByrefVariable() const {
138 assert(Var && "Invalid complex DbgVariable!");
139 return Var->getType()
140 .resolve(DD->getTypeIdentifierMap())
141 ->isBlockByrefStruct();
144 const MDType *DbgVariable::getType() const {
145 MDType *Ty = Var->getType().resolve(DD->getTypeIdentifierMap());
146 // FIXME: isBlockByrefVariable should be reformulated in terms of complex
147 // addresses instead.
148 if (Ty->isBlockByrefStruct()) {
149 /* Byref variables, in Blocks, are declared by the programmer as
150 "SomeType VarName;", but the compiler creates a
151 __Block_byref_x_VarName struct, and gives the variable VarName
152 either the struct, or a pointer to the struct, as its type. This
153 is necessary for various behind-the-scenes things the compiler
154 needs to do with by-reference variables in blocks.
156 However, as far as the original *programmer* is concerned, the
157 variable should still have type 'SomeType', as originally declared.
159 The following function dives into the __Block_byref_x_VarName
160 struct to find the original type of the variable. This will be
161 passed back to the code generating the type for the Debug
162 Information Entry for the variable 'VarName'. 'VarName' will then
163 have the original type 'SomeType' in its debug information.
165 The original type 'SomeType' will be the type of the field named
166 'VarName' inside the __Block_byref_x_VarName struct.
168 NOTE: In order for this to not completely fail on the debugger
169 side, the Debug Information Entry for the variable VarName needs to
170 have a DW_AT_location that tells the debugger how to unwind through
171 the pointers and __Block_byref_x_VarName struct to find the actual
172 value of the variable. The function addBlockByrefType does this. */
173 MDType *subType = Ty;
174 uint16_t tag = Ty->getTag();
176 if (tag == dwarf::DW_TAG_pointer_type)
177 subType = resolve(cast<MDDerivedType>(Ty)->getBaseType());
179 auto Elements = cast<MDCompositeTypeBase>(subType)->getElements();
180 for (unsigned i = 0, N = Elements.size(); i < N; ++i) {
181 auto *DT = cast<MDDerivedTypeBase>(Elements[i]);
182 if (getName() == DT->getName())
183 return resolve(DT->getBaseType());
189 static LLVM_CONSTEXPR DwarfAccelTable::Atom TypeAtoms[] = {
190 DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset, dwarf::DW_FORM_data4),
191 DwarfAccelTable::Atom(dwarf::DW_ATOM_die_tag, dwarf::DW_FORM_data2),
192 DwarfAccelTable::Atom(dwarf::DW_ATOM_type_flags, dwarf::DW_FORM_data1)};
194 DwarfDebug::DwarfDebug(AsmPrinter *A, Module *M)
195 : Asm(A), MMI(Asm->MMI), PrevLabel(nullptr),
196 InfoHolder(A, "info_string", DIEValueAllocator),
197 UsedNonDefaultText(false),
198 SkeletonHolder(A, "skel_string", DIEValueAllocator),
199 IsDarwin(Triple(A->getTargetTriple()).isOSDarwin()),
200 IsPS4(Triple(A->getTargetTriple()).isPS4()),
201 AccelNames(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
202 dwarf::DW_FORM_data4)),
203 AccelObjC(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
204 dwarf::DW_FORM_data4)),
205 AccelNamespace(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
206 dwarf::DW_FORM_data4)),
207 AccelTypes(TypeAtoms) {
212 // Turn on accelerator tables for Darwin by default, pubnames by
213 // default for non-Darwin/PS4, and handle split dwarf.
214 if (DwarfAccelTables == Default)
215 HasDwarfAccelTables = IsDarwin;
217 HasDwarfAccelTables = DwarfAccelTables == Enable;
219 if (SplitDwarf == Default)
220 HasSplitDwarf = false;
222 HasSplitDwarf = SplitDwarf == Enable;
224 if (DwarfPubSections == Default)
225 HasDwarfPubSections = !IsDarwin && !IsPS4;
227 HasDwarfPubSections = DwarfPubSections == Enable;
229 unsigned DwarfVersionNumber = Asm->TM.Options.MCOptions.DwarfVersion;
230 DwarfVersion = DwarfVersionNumber ? DwarfVersionNumber
231 : MMI->getModule()->getDwarfVersion();
233 // Darwin and PS4 use the standard TLS opcode (defined in DWARF 3).
234 // Everybody else uses GNU's.
235 UseGNUTLSOpcode = !(IsDarwin || IsPS4) || DwarfVersion < 3;
237 Asm->OutStreamer.getContext().setDwarfVersion(DwarfVersion);
240 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
245 // Define out of line so we don't have to include DwarfUnit.h in DwarfDebug.h.
246 DwarfDebug::~DwarfDebug() { }
248 static bool isObjCClass(StringRef Name) {
249 return Name.startswith("+") || Name.startswith("-");
252 static bool hasObjCCategory(StringRef Name) {
253 if (!isObjCClass(Name))
256 return Name.find(") ") != StringRef::npos;
259 static void getObjCClassCategory(StringRef In, StringRef &Class,
260 StringRef &Category) {
261 if (!hasObjCCategory(In)) {
262 Class = In.slice(In.find('[') + 1, In.find(' '));
267 Class = In.slice(In.find('[') + 1, In.find('('));
268 Category = In.slice(In.find('[') + 1, In.find(' '));
272 static StringRef getObjCMethodName(StringRef In) {
273 return In.slice(In.find(' ') + 1, In.find(']'));
276 // Add the various names to the Dwarf accelerator table names.
277 // TODO: Determine whether or not we should add names for programs
278 // that do not have a DW_AT_name or DW_AT_linkage_name field - this
279 // is only slightly different than the lookup of non-standard ObjC names.
280 void DwarfDebug::addSubprogramNames(const MDSubprogram *SP, DIE &Die) {
281 if (!SP->isDefinition())
283 addAccelName(SP->getName(), Die);
285 // If the linkage name is different than the name, go ahead and output
286 // that as well into the name table.
287 if (SP->getLinkageName() != "" && SP->getName() != SP->getLinkageName())
288 addAccelName(SP->getLinkageName(), Die);
290 // If this is an Objective-C selector name add it to the ObjC accelerator
292 if (isObjCClass(SP->getName())) {
293 StringRef Class, Category;
294 getObjCClassCategory(SP->getName(), Class, Category);
295 addAccelObjC(Class, Die);
297 addAccelObjC(Category, Die);
298 // Also add the base method name to the name table.
299 addAccelName(getObjCMethodName(SP->getName()), Die);
303 /// isSubprogramContext - Return true if Context is either a subprogram
304 /// or another context nested inside a subprogram.
305 bool DwarfDebug::isSubprogramContext(const MDNode *Context) {
308 if (isa<MDSubprogram>(Context))
310 if (auto *T = dyn_cast<MDType>(Context))
311 return isSubprogramContext(resolve(T->getScope()));
315 /// Check whether we should create a DIE for the given Scope, return true
316 /// if we don't create a DIE (the corresponding DIE is null).
317 bool DwarfDebug::isLexicalScopeDIENull(LexicalScope *Scope) {
318 if (Scope->isAbstractScope())
321 // We don't create a DIE if there is no Range.
322 const SmallVectorImpl<InsnRange> &Ranges = Scope->getRanges();
326 if (Ranges.size() > 1)
329 // We don't create a DIE if we have a single Range and the end label
331 return !getLabelAfterInsn(Ranges.front().second);
334 template <typename Func> void forBothCUs(DwarfCompileUnit &CU, Func F) {
336 if (auto *SkelCU = CU.getSkeleton())
340 void DwarfDebug::constructAbstractSubprogramScopeDIE(LexicalScope *Scope) {
341 assert(Scope && Scope->getScopeNode());
342 assert(Scope->isAbstractScope());
343 assert(!Scope->getInlinedAt());
345 const MDNode *SP = Scope->getScopeNode();
347 ProcessedSPNodes.insert(SP);
349 // Find the subprogram's DwarfCompileUnit in the SPMap in case the subprogram
350 // was inlined from another compile unit.
351 auto &CU = SPMap[SP];
352 forBothCUs(*CU, [&](DwarfCompileUnit &CU) {
353 CU.constructAbstractSubprogramScopeDIE(Scope);
357 void DwarfDebug::addGnuPubAttributes(DwarfUnit &U, DIE &D) const {
358 if (!GenerateGnuPubSections)
361 U.addFlag(D, dwarf::DW_AT_GNU_pubnames);
364 // Create new DwarfCompileUnit for the given metadata node with tag
365 // DW_TAG_compile_unit.
367 DwarfDebug::constructDwarfCompileUnit(const MDCompileUnit *DIUnit) {
368 StringRef FN = DIUnit->getFilename();
369 CompilationDir = DIUnit->getDirectory();
371 auto OwnedUnit = make_unique<DwarfCompileUnit>(
372 InfoHolder.getUnits().size(), DIUnit, Asm, this, &InfoHolder);
373 DwarfCompileUnit &NewCU = *OwnedUnit;
374 DIE &Die = NewCU.getUnitDie();
375 InfoHolder.addUnit(std::move(OwnedUnit));
377 NewCU.setSkeleton(constructSkeletonCU(NewCU));
379 // LTO with assembly output shares a single line table amongst multiple CUs.
380 // To avoid the compilation directory being ambiguous, let the line table
381 // explicitly describe the directory of all files, never relying on the
382 // compilation directory.
383 if (!Asm->OutStreamer.hasRawTextSupport() || SingleCU)
384 Asm->OutStreamer.getContext().setMCLineTableCompilationDir(
385 NewCU.getUniqueID(), CompilationDir);
387 NewCU.addString(Die, dwarf::DW_AT_producer, DIUnit->getProducer());
388 NewCU.addUInt(Die, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
389 DIUnit->getSourceLanguage());
390 NewCU.addString(Die, dwarf::DW_AT_name, FN);
392 if (!useSplitDwarf()) {
393 NewCU.initStmtList();
395 // If we're using split dwarf the compilation dir is going to be in the
396 // skeleton CU and so we don't need to duplicate it here.
397 if (!CompilationDir.empty())
398 NewCU.addString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
400 addGnuPubAttributes(NewCU, Die);
403 if (DIUnit->isOptimized())
404 NewCU.addFlag(Die, dwarf::DW_AT_APPLE_optimized);
406 StringRef Flags = DIUnit->getFlags();
408 NewCU.addString(Die, dwarf::DW_AT_APPLE_flags, Flags);
410 if (unsigned RVer = DIUnit->getRuntimeVersion())
411 NewCU.addUInt(Die, dwarf::DW_AT_APPLE_major_runtime_vers,
412 dwarf::DW_FORM_data1, RVer);
415 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoDWOSection());
417 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoSection());
419 CUMap.insert(std::make_pair(DIUnit, &NewCU));
420 CUDieMap.insert(std::make_pair(&Die, &NewCU));
424 void DwarfDebug::constructAndAddImportedEntityDIE(DwarfCompileUnit &TheCU,
425 const MDImportedEntity *N) {
426 if (DIE *D = TheCU.getOrCreateContextDIE(N->getScope()))
427 D->addChild(TheCU.constructImportedEntityDIE(N));
430 // Emit all Dwarf sections that should come prior to the content. Create
431 // global DIEs and emit initial debug info sections. This is invoked by
432 // the target AsmPrinter.
433 void DwarfDebug::beginModule() {
434 if (DisableDebugInfoPrinting)
437 const Module *M = MMI->getModule();
439 FunctionDIs = makeSubprogramMap(*M);
441 NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
444 TypeIdentifierMap = generateDITypeIdentifierMap(CU_Nodes);
446 SingleCU = CU_Nodes->getNumOperands() == 1;
448 for (MDNode *N : CU_Nodes->operands()) {
449 auto *CUNode = cast<MDCompileUnit>(N);
450 DwarfCompileUnit &CU = constructDwarfCompileUnit(CUNode);
451 for (auto *IE : CUNode->getImportedEntities())
452 ScopesWithImportedEntities.push_back(std::make_pair(IE->getScope(), IE));
453 // Stable sort to preserve the order of appearance of imported entities.
454 // This is to avoid out-of-order processing of interdependent declarations
455 // within the same scope, e.g. { namespace A = base; namespace B = A; }
456 std::stable_sort(ScopesWithImportedEntities.begin(),
457 ScopesWithImportedEntities.end(), less_first());
458 for (auto *GV : CUNode->getGlobalVariables())
459 CU.getOrCreateGlobalVariableDIE(GV);
460 for (auto *SP : CUNode->getSubprograms())
461 SPMap.insert(std::make_pair(SP, &CU));
462 for (auto *Ty : CUNode->getEnumTypes()) {
463 // The enum types array by design contains pointers to
464 // MDNodes rather than DIRefs. Unique them here.
465 CU.getOrCreateTypeDIE(cast<MDType>(resolve(Ty->getRef())));
467 for (auto *Ty : CUNode->getRetainedTypes()) {
468 // The retained types array by design contains pointers to
469 // MDNodes rather than DIRefs. Unique them here.
470 CU.getOrCreateTypeDIE(cast<MDType>(resolve(Ty->getRef())));
472 // Emit imported_modules last so that the relevant context is already
474 for (auto *IE : CUNode->getImportedEntities())
475 constructAndAddImportedEntityDIE(CU, IE);
478 // Tell MMI that we have debug info.
479 MMI->setDebugInfoAvailability(true);
482 void DwarfDebug::finishVariableDefinitions() {
483 for (const auto &Var : ConcreteVariables) {
484 DIE *VariableDie = Var->getDIE();
486 // FIXME: Consider the time-space tradeoff of just storing the unit pointer
487 // in the ConcreteVariables list, rather than looking it up again here.
488 // DIE::getUnit isn't simple - it walks parent pointers, etc.
489 DwarfCompileUnit *Unit = lookupUnit(VariableDie->getUnit());
491 DbgVariable *AbsVar = getExistingAbstractVariable(
492 InlinedVariable(Var->getVariable(), Var->getInlinedAt()));
493 if (AbsVar && AbsVar->getDIE()) {
494 Unit->addDIEEntry(*VariableDie, dwarf::DW_AT_abstract_origin,
497 Unit->applyVariableAttributes(*Var, *VariableDie);
501 void DwarfDebug::finishSubprogramDefinitions() {
502 for (const auto &P : SPMap)
503 forBothCUs(*P.second, [&](DwarfCompileUnit &CU) {
504 CU.finishSubprogramDefinition(cast<MDSubprogram>(P.first));
509 // Collect info for variables that were optimized out.
510 void DwarfDebug::collectDeadVariables() {
511 const Module *M = MMI->getModule();
513 if (NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu")) {
514 for (MDNode *N : CU_Nodes->operands()) {
515 auto *TheCU = cast<MDCompileUnit>(N);
516 // Construct subprogram DIE and add variables DIEs.
517 DwarfCompileUnit *SPCU =
518 static_cast<DwarfCompileUnit *>(CUMap.lookup(TheCU));
519 assert(SPCU && "Unable to find Compile Unit!");
520 for (auto *SP : TheCU->getSubprograms()) {
521 if (ProcessedSPNodes.count(SP) != 0)
523 SPCU->collectDeadVariables(SP);
529 void DwarfDebug::finalizeModuleInfo() {
530 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
532 finishSubprogramDefinitions();
534 finishVariableDefinitions();
536 // Collect info for variables that were optimized out.
537 collectDeadVariables();
539 // Handle anything that needs to be done on a per-unit basis after
540 // all other generation.
541 for (const auto &P : CUMap) {
542 auto &TheCU = *P.second;
543 // Emit DW_AT_containing_type attribute to connect types with their
544 // vtable holding type.
545 TheCU.constructContainingTypeDIEs();
547 // Add CU specific attributes if we need to add any.
548 // If we're splitting the dwarf out now that we've got the entire
549 // CU then add the dwo id to it.
550 auto *SkCU = TheCU.getSkeleton();
551 if (useSplitDwarf()) {
552 // Emit a unique identifier for this CU.
553 uint64_t ID = DIEHash(Asm).computeCUSignature(TheCU.getUnitDie());
554 TheCU.addUInt(TheCU.getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
555 dwarf::DW_FORM_data8, ID);
556 SkCU->addUInt(SkCU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
557 dwarf::DW_FORM_data8, ID);
559 // We don't keep track of which addresses are used in which CU so this
560 // is a bit pessimistic under LTO.
561 if (!AddrPool.isEmpty()) {
562 const MCSymbol *Sym = TLOF.getDwarfAddrSection()->getBeginSymbol();
563 SkCU->addSectionLabel(SkCU->getUnitDie(), dwarf::DW_AT_GNU_addr_base,
566 if (!SkCU->getRangeLists().empty()) {
567 const MCSymbol *Sym = TLOF.getDwarfRangesSection()->getBeginSymbol();
568 SkCU->addSectionLabel(SkCU->getUnitDie(), dwarf::DW_AT_GNU_ranges_base,
573 // If we have code split among multiple sections or non-contiguous
574 // ranges of code then emit a DW_AT_ranges attribute on the unit that will
575 // remain in the .o file, otherwise add a DW_AT_low_pc.
576 // FIXME: We should use ranges allow reordering of code ala
577 // .subsections_via_symbols in mach-o. This would mean turning on
578 // ranges for all subprogram DIEs for mach-o.
579 DwarfCompileUnit &U = SkCU ? *SkCU : TheCU;
580 if (unsigned NumRanges = TheCU.getRanges().size()) {
582 // A DW_AT_low_pc attribute may also be specified in combination with
583 // DW_AT_ranges to specify the default base address for use in
584 // location lists (see Section 2.6.2) and range lists (see Section
586 U.addUInt(U.getUnitDie(), dwarf::DW_AT_low_pc, dwarf::DW_FORM_addr, 0);
588 TheCU.setBaseAddress(TheCU.getRanges().front().getStart());
589 U.attachRangesOrLowHighPC(U.getUnitDie(), TheCU.takeRanges());
593 // Compute DIE offsets and sizes.
594 InfoHolder.computeSizeAndOffsets();
596 SkeletonHolder.computeSizeAndOffsets();
599 // Emit all Dwarf sections that should come after the content.
600 void DwarfDebug::endModule() {
601 assert(CurFn == nullptr);
602 assert(CurMI == nullptr);
604 // If we aren't actually generating debug info (check beginModule -
605 // conditionalized on !DisableDebugInfoPrinting and the presence of the
606 // llvm.dbg.cu metadata node)
607 if (!MMI->hasDebugInfo())
610 // Finalize the debug info for the module.
611 finalizeModuleInfo();
618 // Emit info into a debug loc section.
621 // Corresponding abbreviations into a abbrev section.
624 // Emit all the DIEs into a debug info section.
627 // Emit info into a debug aranges section.
628 if (GenerateARangeSection)
631 // Emit info into a debug ranges section.
634 if (useSplitDwarf()) {
637 emitDebugAbbrevDWO();
639 // Emit DWO addresses.
640 AddrPool.emit(*Asm, Asm->getObjFileLowering().getDwarfAddrSection());
643 // Emit info into the dwarf accelerator table sections.
644 if (useDwarfAccelTables()) {
647 emitAccelNamespaces();
651 // Emit the pubnames and pubtypes sections if requested.
652 if (HasDwarfPubSections) {
653 emitDebugPubNames(GenerateGnuPubSections);
654 emitDebugPubTypes(GenerateGnuPubSections);
659 AbstractVariables.clear();
662 // Find abstract variable, if any, associated with Var.
664 DwarfDebug::getExistingAbstractVariable(InlinedVariable IV,
665 const MDLocalVariable *&Cleansed) {
666 // More then one inlined variable corresponds to one abstract variable.
668 auto I = AbstractVariables.find(Cleansed);
669 if (I != AbstractVariables.end())
670 return I->second.get();
674 DbgVariable *DwarfDebug::getExistingAbstractVariable(InlinedVariable IV) {
675 const MDLocalVariable *Cleansed;
676 return getExistingAbstractVariable(IV, Cleansed);
679 void DwarfDebug::createAbstractVariable(const MDLocalVariable *Var,
680 LexicalScope *Scope) {
681 auto AbsDbgVariable =
682 make_unique<DbgVariable>(Var, /* IA */ nullptr, /* Expr */ nullptr, this);
683 InfoHolder.addScopeVariable(Scope, AbsDbgVariable.get());
684 AbstractVariables[Var] = std::move(AbsDbgVariable);
687 void DwarfDebug::ensureAbstractVariableIsCreated(InlinedVariable IV,
688 const MDNode *ScopeNode) {
689 const MDLocalVariable *Cleansed = nullptr;
690 if (getExistingAbstractVariable(IV, Cleansed))
693 createAbstractVariable(Cleansed, LScopes.getOrCreateAbstractScope(
694 cast<MDLocalScope>(ScopeNode)));
697 void DwarfDebug::ensureAbstractVariableIsCreatedIfScoped(
698 InlinedVariable IV, const MDNode *ScopeNode) {
699 const MDLocalVariable *Cleansed = nullptr;
700 if (getExistingAbstractVariable(IV, Cleansed))
703 if (LexicalScope *Scope =
704 LScopes.findAbstractScope(cast_or_null<MDLocalScope>(ScopeNode)))
705 createAbstractVariable(Cleansed, Scope);
708 // Collect variable information from side table maintained by MMI.
709 void DwarfDebug::collectVariableInfoFromMMITable(
710 DenseSet<InlinedVariable> &Processed) {
711 for (const auto &VI : MMI->getVariableDbgInfo()) {
714 assert(VI.Var->isValidLocationForIntrinsic(VI.Loc) &&
715 "Expected inlined-at fields to agree");
717 InlinedVariable Var(VI.Var, VI.Loc->getInlinedAt());
718 Processed.insert(Var);
719 LexicalScope *Scope = LScopes.findLexicalScope(VI.Loc);
721 // If variable scope is not found then skip this variable.
725 const MDExpression *Expr = cast_or_null<MDExpression>(VI.Expr);
726 ensureAbstractVariableIsCreatedIfScoped(Var, Scope->getScopeNode());
728 make_unique<DbgVariable>(Var.first, Var.second, Expr, this, VI.Slot);
729 if (InfoHolder.addScopeVariable(Scope, RegVar.get()))
730 ConcreteVariables.push_back(std::move(RegVar));
734 // Get .debug_loc entry for the instruction range starting at MI.
735 static DebugLocEntry::Value getDebugLocValue(const MachineInstr *MI) {
736 const MDExpression *Expr = MI->getDebugExpression();
738 assert(MI->getNumOperands() == 4);
739 if (MI->getOperand(0).isReg()) {
740 MachineLocation MLoc;
741 // If the second operand is an immediate, this is a
742 // register-indirect address.
743 if (!MI->getOperand(1).isImm())
744 MLoc.set(MI->getOperand(0).getReg());
746 MLoc.set(MI->getOperand(0).getReg(), MI->getOperand(1).getImm());
747 return DebugLocEntry::Value(Expr, MLoc);
749 if (MI->getOperand(0).isImm())
750 return DebugLocEntry::Value(Expr, MI->getOperand(0).getImm());
751 if (MI->getOperand(0).isFPImm())
752 return DebugLocEntry::Value(Expr, MI->getOperand(0).getFPImm());
753 if (MI->getOperand(0).isCImm())
754 return DebugLocEntry::Value(Expr, MI->getOperand(0).getCImm());
756 llvm_unreachable("Unexpected 4-operand DBG_VALUE instruction!");
759 /// Determine whether two variable pieces overlap.
760 static bool piecesOverlap(const MDExpression *P1, const MDExpression *P2) {
761 if (!P1->isBitPiece() || !P2->isBitPiece())
763 unsigned l1 = P1->getBitPieceOffset();
764 unsigned l2 = P2->getBitPieceOffset();
765 unsigned r1 = l1 + P1->getBitPieceSize();
766 unsigned r2 = l2 + P2->getBitPieceSize();
767 // True where [l1,r1[ and [r1,r2[ overlap.
768 return (l1 < r2) && (l2 < r1);
771 /// Build the location list for all DBG_VALUEs in the function that
772 /// describe the same variable. If the ranges of several independent
773 /// pieces of the same variable overlap partially, split them up and
774 /// combine the ranges. The resulting DebugLocEntries are will have
775 /// strict monotonically increasing begin addresses and will never
780 // Ranges History [var, loc, piece ofs size]
781 // 0 | [x, (reg0, piece 0, 32)]
782 // 1 | | [x, (reg1, piece 32, 32)] <- IsPieceOfPrevEntry
784 // 3 | [clobber reg0]
785 // 4 [x, (mem, piece 0, 64)] <- overlapping with both previous pieces of
790 // [0-1] [x, (reg0, piece 0, 32)]
791 // [1-3] [x, (reg0, piece 0, 32), (reg1, piece 32, 32)]
792 // [3-4] [x, (reg1, piece 32, 32)]
793 // [4- ] [x, (mem, piece 0, 64)]
795 DwarfDebug::buildLocationList(SmallVectorImpl<DebugLocEntry> &DebugLoc,
796 const DbgValueHistoryMap::InstrRanges &Ranges) {
797 SmallVector<DebugLocEntry::Value, 4> OpenRanges;
799 for (auto I = Ranges.begin(), E = Ranges.end(); I != E; ++I) {
800 const MachineInstr *Begin = I->first;
801 const MachineInstr *End = I->second;
802 assert(Begin->isDebugValue() && "Invalid History entry");
804 // Check if a variable is inaccessible in this range.
805 if (Begin->getNumOperands() > 1 &&
806 Begin->getOperand(0).isReg() && !Begin->getOperand(0).getReg()) {
811 // If this piece overlaps with any open ranges, truncate them.
812 const MDExpression *DIExpr = Begin->getDebugExpression();
813 auto Last = std::remove_if(OpenRanges.begin(), OpenRanges.end(),
814 [&](DebugLocEntry::Value R) {
815 return piecesOverlap(DIExpr, R.getExpression());
817 OpenRanges.erase(Last, OpenRanges.end());
819 const MCSymbol *StartLabel = getLabelBeforeInsn(Begin);
820 assert(StartLabel && "Forgot label before DBG_VALUE starting a range!");
822 const MCSymbol *EndLabel;
824 EndLabel = getLabelAfterInsn(End);
825 else if (std::next(I) == Ranges.end())
826 EndLabel = Asm->getFunctionEnd();
828 EndLabel = getLabelBeforeInsn(std::next(I)->first);
829 assert(EndLabel && "Forgot label after instruction ending a range!");
831 DEBUG(dbgs() << "DotDebugLoc: " << *Begin << "\n");
833 auto Value = getDebugLocValue(Begin);
834 DebugLocEntry Loc(StartLabel, EndLabel, Value);
835 bool couldMerge = false;
837 // If this is a piece, it may belong to the current DebugLocEntry.
838 if (DIExpr->isBitPiece()) {
839 // Add this value to the list of open ranges.
840 OpenRanges.push_back(Value);
842 // Attempt to add the piece to the last entry.
843 if (!DebugLoc.empty())
844 if (DebugLoc.back().MergeValues(Loc))
849 // Need to add a new DebugLocEntry. Add all values from still
850 // valid non-overlapping pieces.
851 if (OpenRanges.size())
852 Loc.addValues(OpenRanges);
854 DebugLoc.push_back(std::move(Loc));
857 // Attempt to coalesce the ranges of two otherwise identical
859 auto CurEntry = DebugLoc.rbegin();
860 auto PrevEntry = std::next(CurEntry);
861 if (PrevEntry != DebugLoc.rend() && PrevEntry->MergeRanges(*CurEntry))
865 dbgs() << CurEntry->getValues().size() << " Values:\n";
866 for (auto Value : CurEntry->getValues()) {
867 Value.getExpression()->dump();
875 // Find variables for each lexical scope.
876 void DwarfDebug::collectVariableInfo(DwarfCompileUnit &TheCU,
877 const MDSubprogram *SP,
878 DenseSet<InlinedVariable> &Processed) {
879 // Grab the variable info that was squirreled away in the MMI side-table.
880 collectVariableInfoFromMMITable(Processed);
882 for (const auto &I : DbgValues) {
883 InlinedVariable IV = I.first;
884 if (Processed.count(IV))
887 // Instruction ranges, specifying where IV is accessible.
888 const auto &Ranges = I.second;
892 LexicalScope *Scope = nullptr;
893 if (const MDLocation *IA = IV.second)
894 Scope = LScopes.findInlinedScope(IV.first->getScope(), IA);
896 Scope = LScopes.findLexicalScope(IV.first->getScope());
897 // If variable scope is not found then skip this variable.
901 Processed.insert(IV);
902 const MachineInstr *MInsn = Ranges.front().first;
903 assert(MInsn->isDebugValue() && "History must begin with debug value");
904 ensureAbstractVariableIsCreatedIfScoped(IV, Scope->getScopeNode());
905 ConcreteVariables.push_back(make_unique<DbgVariable>(MInsn, this));
906 DbgVariable *RegVar = ConcreteVariables.back().get();
907 InfoHolder.addScopeVariable(Scope, RegVar);
909 // Check if the first DBG_VALUE is valid for the rest of the function.
910 if (Ranges.size() == 1 && Ranges.front().second == nullptr)
913 // Handle multiple DBG_VALUE instructions describing one variable.
914 RegVar->setDebugLocListIndex(
915 DebugLocs.startList(&TheCU, Asm->createTempSymbol("debug_loc")));
917 // Build the location list for this variable.
918 SmallVector<DebugLocEntry, 8> Entries;
919 buildLocationList(Entries, Ranges);
921 // If the variable has an MDBasicType, extract it. Basic types cannot have
922 // unique identifiers, so don't bother resolving the type with the
924 const MDBasicType *BT = dyn_cast<MDBasicType>(
925 static_cast<const Metadata *>(IV.first->getType()));
927 // Finalize the entry by lowering it into a DWARF bytestream.
928 for (auto &Entry : Entries)
929 Entry.finalize(*Asm, DebugLocs, BT);
932 // Collect info for variables that were optimized out.
933 for (const MDLocalVariable *DV : SP->getVariables()) {
934 if (!Processed.insert(InlinedVariable(DV, nullptr)).second)
936 if (LexicalScope *Scope = LScopes.findLexicalScope(DV->getScope())) {
937 ensureAbstractVariableIsCreatedIfScoped(InlinedVariable(DV, nullptr),
938 Scope->getScopeNode());
939 ConcreteVariables.push_back(make_unique<DbgVariable>(
940 DV, /* IA */ nullptr, /* Expr */ nullptr, this));
941 InfoHolder.addScopeVariable(Scope, ConcreteVariables.back().get());
946 // Return Label preceding the instruction.
947 MCSymbol *DwarfDebug::getLabelBeforeInsn(const MachineInstr *MI) {
948 MCSymbol *Label = LabelsBeforeInsn.lookup(MI);
949 assert(Label && "Didn't insert label before instruction");
953 // Return Label immediately following the instruction.
954 MCSymbol *DwarfDebug::getLabelAfterInsn(const MachineInstr *MI) {
955 return LabelsAfterInsn.lookup(MI);
958 // Process beginning of an instruction.
959 void DwarfDebug::beginInstruction(const MachineInstr *MI) {
960 assert(CurMI == nullptr);
962 // Check if source location changes, but ignore DBG_VALUE locations.
963 if (!MI->isDebugValue()) {
964 DebugLoc DL = MI->getDebugLoc();
965 if (DL != PrevInstLoc) {
969 if (DL == PrologEndLoc) {
970 Flags |= DWARF2_FLAG_PROLOGUE_END;
971 PrologEndLoc = DebugLoc();
972 Flags |= DWARF2_FLAG_IS_STMT;
975 Asm->OutStreamer.getContext().getCurrentDwarfLoc().getLine())
976 Flags |= DWARF2_FLAG_IS_STMT;
978 const MDNode *Scope = DL.getScope();
979 recordSourceLine(DL.getLine(), DL.getCol(), Scope, Flags);
980 } else if (UnknownLocations) {
982 recordSourceLine(0, 0, nullptr, 0);
987 // Insert labels where requested.
988 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
989 LabelsBeforeInsn.find(MI);
992 if (I == LabelsBeforeInsn.end())
995 // Label already assigned.
1000 PrevLabel = MMI->getContext().CreateTempSymbol();
1001 Asm->OutStreamer.EmitLabel(PrevLabel);
1003 I->second = PrevLabel;
1006 // Process end of an instruction.
1007 void DwarfDebug::endInstruction() {
1008 assert(CurMI != nullptr);
1009 // Don't create a new label after DBG_VALUE instructions.
1010 // They don't generate code.
1011 if (!CurMI->isDebugValue())
1012 PrevLabel = nullptr;
1014 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1015 LabelsAfterInsn.find(CurMI);
1019 if (I == LabelsAfterInsn.end())
1022 // Label already assigned.
1026 // We need a label after this instruction.
1028 PrevLabel = MMI->getContext().CreateTempSymbol();
1029 Asm->OutStreamer.EmitLabel(PrevLabel);
1031 I->second = PrevLabel;
1034 // Each LexicalScope has first instruction and last instruction to mark
1035 // beginning and end of a scope respectively. Create an inverse map that list
1036 // scopes starts (and ends) with an instruction. One instruction may start (or
1037 // end) multiple scopes. Ignore scopes that are not reachable.
1038 void DwarfDebug::identifyScopeMarkers() {
1039 SmallVector<LexicalScope *, 4> WorkList;
1040 WorkList.push_back(LScopes.getCurrentFunctionScope());
1041 while (!WorkList.empty()) {
1042 LexicalScope *S = WorkList.pop_back_val();
1044 const SmallVectorImpl<LexicalScope *> &Children = S->getChildren();
1045 if (!Children.empty())
1046 WorkList.append(Children.begin(), Children.end());
1048 if (S->isAbstractScope())
1051 for (const InsnRange &R : S->getRanges()) {
1052 assert(R.first && "InsnRange does not have first instruction!");
1053 assert(R.second && "InsnRange does not have second instruction!");
1054 requestLabelBeforeInsn(R.first);
1055 requestLabelAfterInsn(R.second);
1060 static DebugLoc findPrologueEndLoc(const MachineFunction *MF) {
1061 // First known non-DBG_VALUE and non-frame setup location marks
1062 // the beginning of the function body.
1063 for (const auto &MBB : *MF)
1064 for (const auto &MI : MBB)
1065 if (!MI.isDebugValue() && !MI.getFlag(MachineInstr::FrameSetup) &&
1067 // Did the target forget to set the FrameSetup flag for CFI insns?
1068 assert(!MI.isCFIInstruction() &&
1069 "First non-frame-setup instruction is a CFI instruction.");
1070 return MI.getDebugLoc();
1075 // Gather pre-function debug information. Assumes being called immediately
1076 // after the function entry point has been emitted.
1077 void DwarfDebug::beginFunction(const MachineFunction *MF) {
1080 // If there's no debug info for the function we're not going to do anything.
1081 if (!MMI->hasDebugInfo())
1084 auto DI = FunctionDIs.find(MF->getFunction());
1085 if (DI == FunctionDIs.end())
1088 // Grab the lexical scopes for the function, if we don't have any of those
1089 // then we're not going to be able to do anything.
1090 LScopes.initialize(*MF);
1091 if (LScopes.empty())
1094 assert(DbgValues.empty() && "DbgValues map wasn't cleaned!");
1096 // Make sure that each lexical scope will have a begin/end label.
1097 identifyScopeMarkers();
1099 // Set DwarfDwarfCompileUnitID in MCContext to the Compile Unit this function
1100 // belongs to so that we add to the correct per-cu line table in the
1102 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1103 // FnScope->getScopeNode() and DI->second should represent the same function,
1104 // though they may not be the same MDNode due to inline functions merged in
1105 // LTO where the debug info metadata still differs (either due to distinct
1106 // written differences - two versions of a linkonce_odr function
1107 // written/copied into two separate files, or some sub-optimal metadata that
1108 // isn't structurally identical (see: file path/name info from clang, which
1109 // includes the directory of the cpp file being built, even when the file name
1110 // is absolute (such as an <> lookup header)))
1111 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1112 assert(TheCU && "Unable to find compile unit!");
1113 if (Asm->OutStreamer.hasRawTextSupport())
1114 // Use a single line table if we are generating assembly.
1115 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1117 Asm->OutStreamer.getContext().setDwarfCompileUnitID(TheCU->getUniqueID());
1119 // Calculate history for local variables.
1120 calculateDbgValueHistory(MF, Asm->MF->getSubtarget().getRegisterInfo(),
1123 // Request labels for the full history.
1124 for (const auto &I : DbgValues) {
1125 const auto &Ranges = I.second;
1129 // The first mention of a function argument gets the CurrentFnBegin
1130 // label, so arguments are visible when breaking at function entry.
1131 const MDLocalVariable *DIVar = Ranges.front().first->getDebugVariable();
1132 if (DIVar->getTag() == dwarf::DW_TAG_arg_variable &&
1133 getDISubprogram(DIVar->getScope())->describes(MF->getFunction())) {
1134 LabelsBeforeInsn[Ranges.front().first] = Asm->getFunctionBegin();
1135 if (Ranges.front().first->getDebugExpression()->isBitPiece()) {
1136 // Mark all non-overlapping initial pieces.
1137 for (auto I = Ranges.begin(); I != Ranges.end(); ++I) {
1138 const MDExpression *Piece = I->first->getDebugExpression();
1139 if (std::all_of(Ranges.begin(), I,
1140 [&](DbgValueHistoryMap::InstrRange Pred) {
1141 return !piecesOverlap(Piece, Pred.first->getDebugExpression());
1143 LabelsBeforeInsn[I->first] = Asm->getFunctionBegin();
1150 for (const auto &Range : Ranges) {
1151 requestLabelBeforeInsn(Range.first);
1153 requestLabelAfterInsn(Range.second);
1157 PrevInstLoc = DebugLoc();
1158 PrevLabel = Asm->getFunctionBegin();
1160 // Record beginning of function.
1161 PrologEndLoc = findPrologueEndLoc(MF);
1162 if (MDLocation *L = PrologEndLoc) {
1163 // We'd like to list the prologue as "not statements" but GDB behaves
1164 // poorly if we do that. Revisit this with caution/GDB (7.5+) testing.
1165 auto *SP = L->getInlinedAtScope()->getSubprogram();
1166 recordSourceLine(SP->getScopeLine(), 0, SP, DWARF2_FLAG_IS_STMT);
1170 // Gather and emit post-function debug information.
1171 void DwarfDebug::endFunction(const MachineFunction *MF) {
1172 assert(CurFn == MF &&
1173 "endFunction should be called with the same function as beginFunction");
1175 if (!MMI->hasDebugInfo() || LScopes.empty() ||
1176 !FunctionDIs.count(MF->getFunction())) {
1177 // If we don't have a lexical scope for this function then there will
1178 // be a hole in the range information. Keep note of this by setting the
1179 // previously used section to nullptr.
1185 // Set DwarfDwarfCompileUnitID in MCContext to default value.
1186 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1188 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1189 auto *SP = cast<MDSubprogram>(FnScope->getScopeNode());
1190 DwarfCompileUnit &TheCU = *SPMap.lookup(SP);
1192 DenseSet<InlinedVariable> ProcessedVars;
1193 collectVariableInfo(TheCU, SP, ProcessedVars);
1195 // Add the range of this function to the list of ranges for the CU.
1196 TheCU.addRange(RangeSpan(Asm->getFunctionBegin(), Asm->getFunctionEnd()));
1198 // Under -gmlt, skip building the subprogram if there are no inlined
1199 // subroutines inside it.
1200 if (TheCU.getCUNode()->getEmissionKind() == DIBuilder::LineTablesOnly &&
1201 LScopes.getAbstractScopesList().empty() && !IsDarwin) {
1202 assert(InfoHolder.getScopeVariables().empty());
1203 assert(DbgValues.empty());
1204 // FIXME: This wouldn't be true in LTO with a -g (with inlining) CU followed
1205 // by a -gmlt CU. Add a test and remove this assertion.
1206 assert(AbstractVariables.empty());
1207 LabelsBeforeInsn.clear();
1208 LabelsAfterInsn.clear();
1209 PrevLabel = nullptr;
1215 size_t NumAbstractScopes = LScopes.getAbstractScopesList().size();
1217 // Construct abstract scopes.
1218 for (LexicalScope *AScope : LScopes.getAbstractScopesList()) {
1219 auto *SP = cast<MDSubprogram>(AScope->getScopeNode());
1220 // Collect info for variables that were optimized out.
1221 for (const MDLocalVariable *DV : SP->getVariables()) {
1222 if (!ProcessedVars.insert(InlinedVariable(DV, nullptr)).second)
1224 ensureAbstractVariableIsCreated(InlinedVariable(DV, nullptr),
1226 assert(LScopes.getAbstractScopesList().size() == NumAbstractScopes
1227 && "ensureAbstractVariableIsCreated inserted abstract scopes");
1229 constructAbstractSubprogramScopeDIE(AScope);
1232 TheCU.constructSubprogramScopeDIE(FnScope);
1233 if (auto *SkelCU = TheCU.getSkeleton())
1234 if (!LScopes.getAbstractScopesList().empty())
1235 SkelCU->constructSubprogramScopeDIE(FnScope);
1238 // Ownership of DbgVariables is a bit subtle - ScopeVariables owns all the
1239 // DbgVariables except those that are also in AbstractVariables (since they
1240 // can be used cross-function)
1241 InfoHolder.getScopeVariables().clear();
1243 LabelsBeforeInsn.clear();
1244 LabelsAfterInsn.clear();
1245 PrevLabel = nullptr;
1249 // Register a source line with debug info. Returns the unique label that was
1250 // emitted and which provides correspondence to the source line list.
1251 void DwarfDebug::recordSourceLine(unsigned Line, unsigned Col, const MDNode *S,
1256 unsigned Discriminator = 0;
1257 if (auto *Scope = cast_or_null<MDScope>(S)) {
1258 Fn = Scope->getFilename();
1259 Dir = Scope->getDirectory();
1260 if (auto *LBF = dyn_cast<MDLexicalBlockFile>(Scope))
1261 Discriminator = LBF->getDiscriminator();
1263 unsigned CUID = Asm->OutStreamer.getContext().getDwarfCompileUnitID();
1264 Src = static_cast<DwarfCompileUnit &>(*InfoHolder.getUnits()[CUID])
1265 .getOrCreateSourceID(Fn, Dir);
1267 Asm->OutStreamer.EmitDwarfLocDirective(Src, Line, Col, Flags, 0,
1271 //===----------------------------------------------------------------------===//
1273 //===----------------------------------------------------------------------===//
1275 // Emit the debug info section.
1276 void DwarfDebug::emitDebugInfo() {
1277 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1278 Holder.emitUnits(/* UseOffsets */ false);
1281 // Emit the abbreviation section.
1282 void DwarfDebug::emitAbbreviations() {
1283 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1285 Holder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevSection());
1288 void DwarfDebug::emitAccel(DwarfAccelTable &Accel, const MCSection *Section,
1289 StringRef TableName) {
1290 Accel.FinalizeTable(Asm, TableName);
1291 Asm->OutStreamer.SwitchSection(Section);
1293 // Emit the full data.
1294 Accel.emit(Asm, Section->getBeginSymbol(), this);
1297 // Emit visible names into a hashed accelerator table section.
1298 void DwarfDebug::emitAccelNames() {
1299 emitAccel(AccelNames, Asm->getObjFileLowering().getDwarfAccelNamesSection(),
1303 // Emit objective C classes and categories into a hashed accelerator table
1305 void DwarfDebug::emitAccelObjC() {
1306 emitAccel(AccelObjC, Asm->getObjFileLowering().getDwarfAccelObjCSection(),
1310 // Emit namespace dies into a hashed accelerator table.
1311 void DwarfDebug::emitAccelNamespaces() {
1312 emitAccel(AccelNamespace,
1313 Asm->getObjFileLowering().getDwarfAccelNamespaceSection(),
1317 // Emit type dies into a hashed accelerator table.
1318 void DwarfDebug::emitAccelTypes() {
1319 emitAccel(AccelTypes, Asm->getObjFileLowering().getDwarfAccelTypesSection(),
1323 // Public name handling.
1324 // The format for the various pubnames:
1326 // dwarf pubnames - offset/name pairs where the offset is the offset into the CU
1327 // for the DIE that is named.
1329 // gnu pubnames - offset/index value/name tuples where the offset is the offset
1330 // into the CU and the index value is computed according to the type of value
1331 // for the DIE that is named.
1333 // For type units the offset is the offset of the skeleton DIE. For split dwarf
1334 // it's the offset within the debug_info/debug_types dwo section, however, the
1335 // reference in the pubname header doesn't change.
1337 /// computeIndexValue - Compute the gdb index value for the DIE and CU.
1338 static dwarf::PubIndexEntryDescriptor computeIndexValue(DwarfUnit *CU,
1340 dwarf::GDBIndexEntryLinkage Linkage = dwarf::GIEL_STATIC;
1342 // We could have a specification DIE that has our most of our knowledge,
1343 // look for that now.
1344 DIEValue *SpecVal = Die->findAttribute(dwarf::DW_AT_specification);
1346 DIE &SpecDIE = cast<DIEEntry>(SpecVal)->getEntry();
1347 if (SpecDIE.findAttribute(dwarf::DW_AT_external))
1348 Linkage = dwarf::GIEL_EXTERNAL;
1349 } else if (Die->findAttribute(dwarf::DW_AT_external))
1350 Linkage = dwarf::GIEL_EXTERNAL;
1352 switch (Die->getTag()) {
1353 case dwarf::DW_TAG_class_type:
1354 case dwarf::DW_TAG_structure_type:
1355 case dwarf::DW_TAG_union_type:
1356 case dwarf::DW_TAG_enumeration_type:
1357 return dwarf::PubIndexEntryDescriptor(
1358 dwarf::GIEK_TYPE, CU->getLanguage() != dwarf::DW_LANG_C_plus_plus
1359 ? dwarf::GIEL_STATIC
1360 : dwarf::GIEL_EXTERNAL);
1361 case dwarf::DW_TAG_typedef:
1362 case dwarf::DW_TAG_base_type:
1363 case dwarf::DW_TAG_subrange_type:
1364 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_TYPE, dwarf::GIEL_STATIC);
1365 case dwarf::DW_TAG_namespace:
1366 return dwarf::GIEK_TYPE;
1367 case dwarf::DW_TAG_subprogram:
1368 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_FUNCTION, Linkage);
1369 case dwarf::DW_TAG_variable:
1370 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE, Linkage);
1371 case dwarf::DW_TAG_enumerator:
1372 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE,
1373 dwarf::GIEL_STATIC);
1375 return dwarf::GIEK_NONE;
1379 /// emitDebugPubNames - Emit visible names into a debug pubnames section.
1381 void DwarfDebug::emitDebugPubNames(bool GnuStyle) {
1382 const MCSection *PSec =
1383 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubNamesSection()
1384 : Asm->getObjFileLowering().getDwarfPubNamesSection();
1386 emitDebugPubSection(GnuStyle, PSec, "Names",
1387 &DwarfCompileUnit::getGlobalNames);
1390 void DwarfDebug::emitDebugPubSection(
1391 bool GnuStyle, const MCSection *PSec, StringRef Name,
1392 const StringMap<const DIE *> &(DwarfCompileUnit::*Accessor)() const) {
1393 for (const auto &NU : CUMap) {
1394 DwarfCompileUnit *TheU = NU.second;
1396 const auto &Globals = (TheU->*Accessor)();
1398 if (Globals.empty())
1401 if (auto *Skeleton = TheU->getSkeleton())
1404 // Start the dwarf pubnames section.
1405 Asm->OutStreamer.SwitchSection(PSec);
1408 Asm->OutStreamer.AddComment("Length of Public " + Name + " Info");
1409 MCSymbol *BeginLabel = Asm->createTempSymbol("pub" + Name + "_begin");
1410 MCSymbol *EndLabel = Asm->createTempSymbol("pub" + Name + "_end");
1411 Asm->EmitLabelDifference(EndLabel, BeginLabel, 4);
1413 Asm->OutStreamer.EmitLabel(BeginLabel);
1415 Asm->OutStreamer.AddComment("DWARF Version");
1416 Asm->EmitInt16(dwarf::DW_PUBNAMES_VERSION);
1418 Asm->OutStreamer.AddComment("Offset of Compilation Unit Info");
1419 Asm->emitSectionOffset(TheU->getLabelBegin());
1421 Asm->OutStreamer.AddComment("Compilation Unit Length");
1422 Asm->EmitInt32(TheU->getLength());
1424 // Emit the pubnames for this compilation unit.
1425 for (const auto &GI : Globals) {
1426 const char *Name = GI.getKeyData();
1427 const DIE *Entity = GI.second;
1429 Asm->OutStreamer.AddComment("DIE offset");
1430 Asm->EmitInt32(Entity->getOffset());
1433 dwarf::PubIndexEntryDescriptor Desc = computeIndexValue(TheU, Entity);
1434 Asm->OutStreamer.AddComment(
1435 Twine("Kind: ") + dwarf::GDBIndexEntryKindString(Desc.Kind) + ", " +
1436 dwarf::GDBIndexEntryLinkageString(Desc.Linkage));
1437 Asm->EmitInt8(Desc.toBits());
1440 Asm->OutStreamer.AddComment("External Name");
1441 Asm->OutStreamer.EmitBytes(StringRef(Name, GI.getKeyLength() + 1));
1444 Asm->OutStreamer.AddComment("End Mark");
1446 Asm->OutStreamer.EmitLabel(EndLabel);
1450 void DwarfDebug::emitDebugPubTypes(bool GnuStyle) {
1451 const MCSection *PSec =
1452 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubTypesSection()
1453 : Asm->getObjFileLowering().getDwarfPubTypesSection();
1455 emitDebugPubSection(GnuStyle, PSec, "Types",
1456 &DwarfCompileUnit::getGlobalTypes);
1459 // Emit visible names into a debug str section.
1460 void DwarfDebug::emitDebugStr() {
1461 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1462 Holder.emitStrings(Asm->getObjFileLowering().getDwarfStrSection());
1465 void DwarfDebug::emitDebugLocEntry(ByteStreamer &Streamer,
1466 const DebugLocStream::Entry &Entry) {
1467 auto &&Comments = DebugLocs.getComments(Entry);
1468 auto Comment = Comments.begin();
1469 auto End = Comments.end();
1470 for (uint8_t Byte : DebugLocs.getBytes(Entry))
1471 Streamer.EmitInt8(Byte, Comment != End ? *(Comment++) : "");
1474 static void emitDebugLocValue(const AsmPrinter &AP, const MDBasicType *BT,
1475 ByteStreamer &Streamer,
1476 const DebugLocEntry::Value &Value,
1477 unsigned PieceOffsetInBits) {
1478 DebugLocDwarfExpression DwarfExpr(*AP.MF->getSubtarget().getRegisterInfo(),
1479 AP.getDwarfDebug()->getDwarfVersion(),
1482 if (Value.isInt()) {
1483 if (BT && (BT->getEncoding() == dwarf::DW_ATE_signed ||
1484 BT->getEncoding() == dwarf::DW_ATE_signed_char))
1485 DwarfExpr.AddSignedConstant(Value.getInt());
1487 DwarfExpr.AddUnsignedConstant(Value.getInt());
1488 } else if (Value.isLocation()) {
1489 MachineLocation Loc = Value.getLoc();
1490 const MDExpression *Expr = Value.getExpression();
1491 if (!Expr || !Expr->getNumElements())
1493 AP.EmitDwarfRegOp(Streamer, Loc);
1495 // Complex address entry.
1496 if (Loc.getOffset()) {
1497 DwarfExpr.AddMachineRegIndirect(Loc.getReg(), Loc.getOffset());
1498 DwarfExpr.AddExpression(Expr->expr_op_begin(), Expr->expr_op_end(),
1501 DwarfExpr.AddMachineRegExpression(Expr, Loc.getReg(),
1505 // else ... ignore constant fp. There is not any good way to
1506 // to represent them here in dwarf.
1510 void DebugLocEntry::finalize(const AsmPrinter &AP, DebugLocStream &Locs,
1511 const MDBasicType *BT) {
1512 Locs.startEntry(Begin, End);
1513 BufferByteStreamer Streamer = Locs.getStreamer();
1514 const DebugLocEntry::Value &Value = Values[0];
1515 if (Value.isBitPiece()) {
1516 // Emit all pieces that belong to the same variable and range.
1517 assert(std::all_of(Values.begin(), Values.end(), [](DebugLocEntry::Value P) {
1518 return P.isBitPiece();
1519 }) && "all values are expected to be pieces");
1520 assert(std::is_sorted(Values.begin(), Values.end()) &&
1521 "pieces are expected to be sorted");
1523 unsigned Offset = 0;
1524 for (auto Piece : Values) {
1525 const MDExpression *Expr = Piece.getExpression();
1526 unsigned PieceOffset = Expr->getBitPieceOffset();
1527 unsigned PieceSize = Expr->getBitPieceSize();
1528 assert(Offset <= PieceOffset && "overlapping or duplicate pieces");
1529 if (Offset < PieceOffset) {
1530 // The DWARF spec seriously mandates pieces with no locations for gaps.
1531 DebugLocDwarfExpression Expr(*AP.MF->getSubtarget().getRegisterInfo(),
1532 AP.getDwarfDebug()->getDwarfVersion(),
1534 Expr.AddOpPiece(PieceOffset-Offset, 0);
1535 Offset += PieceOffset-Offset;
1537 Offset += PieceSize;
1539 emitDebugLocValue(AP, BT, Streamer, Piece, PieceOffset);
1542 assert(Values.size() == 1 && "only pieces may have >1 value");
1543 emitDebugLocValue(AP, BT, Streamer, Value, 0);
1547 void DwarfDebug::emitDebugLocEntryLocation(const DebugLocStream::Entry &Entry) {
1548 Asm->OutStreamer.AddComment("Loc expr size");
1549 MCSymbol *begin = Asm->OutStreamer.getContext().CreateTempSymbol();
1550 MCSymbol *end = Asm->OutStreamer.getContext().CreateTempSymbol();
1551 Asm->EmitLabelDifference(end, begin, 2);
1552 Asm->OutStreamer.EmitLabel(begin);
1554 APByteStreamer Streamer(*Asm);
1555 emitDebugLocEntry(Streamer, Entry);
1557 Asm->OutStreamer.EmitLabel(end);
1560 // Emit locations into the debug loc section.
1561 void DwarfDebug::emitDebugLoc() {
1562 // Start the dwarf loc section.
1563 Asm->OutStreamer.SwitchSection(
1564 Asm->getObjFileLowering().getDwarfLocSection());
1565 unsigned char Size = Asm->getDataLayout().getPointerSize();
1566 for (const auto &List : DebugLocs.getLists()) {
1567 Asm->OutStreamer.EmitLabel(List.Label);
1568 const DwarfCompileUnit *CU = List.CU;
1569 for (const auto &Entry : DebugLocs.getEntries(List)) {
1570 // Set up the range. This range is relative to the entry point of the
1571 // compile unit. This is a hard coded 0 for low_pc when we're emitting
1572 // ranges, or the DW_AT_low_pc on the compile unit otherwise.
1573 if (auto *Base = CU->getBaseAddress()) {
1574 Asm->EmitLabelDifference(Entry.BeginSym, Base, Size);
1575 Asm->EmitLabelDifference(Entry.EndSym, Base, Size);
1577 Asm->OutStreamer.EmitSymbolValue(Entry.BeginSym, Size);
1578 Asm->OutStreamer.EmitSymbolValue(Entry.EndSym, Size);
1581 emitDebugLocEntryLocation(Entry);
1583 Asm->OutStreamer.EmitIntValue(0, Size);
1584 Asm->OutStreamer.EmitIntValue(0, Size);
1588 void DwarfDebug::emitDebugLocDWO() {
1589 Asm->OutStreamer.SwitchSection(
1590 Asm->getObjFileLowering().getDwarfLocDWOSection());
1591 for (const auto &List : DebugLocs.getLists()) {
1592 Asm->OutStreamer.EmitLabel(List.Label);
1593 for (const auto &Entry : DebugLocs.getEntries(List)) {
1594 // Just always use start_length for now - at least that's one address
1595 // rather than two. We could get fancier and try to, say, reuse an
1596 // address we know we've emitted elsewhere (the start of the function?
1597 // The start of the CU or CU subrange that encloses this range?)
1598 Asm->EmitInt8(dwarf::DW_LLE_start_length_entry);
1599 unsigned idx = AddrPool.getIndex(Entry.BeginSym);
1600 Asm->EmitULEB128(idx);
1601 Asm->EmitLabelDifference(Entry.EndSym, Entry.BeginSym, 4);
1603 emitDebugLocEntryLocation(Entry);
1605 Asm->EmitInt8(dwarf::DW_LLE_end_of_list_entry);
1610 const MCSymbol *Start, *End;
1613 // Emit a debug aranges section, containing a CU lookup for any
1614 // address we can tie back to a CU.
1615 void DwarfDebug::emitDebugARanges() {
1616 // Provides a unique id per text section.
1617 MapVector<const MCSection *, SmallVector<SymbolCU, 8>> SectionMap;
1619 // Filter labels by section.
1620 for (const SymbolCU &SCU : ArangeLabels) {
1621 if (SCU.Sym->isInSection()) {
1622 // Make a note of this symbol and it's section.
1623 const MCSection *Section = &SCU.Sym->getSection();
1624 if (!Section->getKind().isMetadata())
1625 SectionMap[Section].push_back(SCU);
1627 // Some symbols (e.g. common/bss on mach-o) can have no section but still
1628 // appear in the output. This sucks as we rely on sections to build
1629 // arange spans. We can do it without, but it's icky.
1630 SectionMap[nullptr].push_back(SCU);
1634 // Add terminating symbols for each section.
1635 for (const auto &I : SectionMap) {
1636 const MCSection *Section = I.first;
1637 MCSymbol *Sym = nullptr;
1640 Sym = Asm->OutStreamer.endSection(Section);
1642 // Insert a final terminator.
1643 SectionMap[Section].push_back(SymbolCU(nullptr, Sym));
1646 DenseMap<DwarfCompileUnit *, std::vector<ArangeSpan>> Spans;
1648 for (auto &I : SectionMap) {
1649 const MCSection *Section = I.first;
1650 SmallVector<SymbolCU, 8> &List = I.second;
1651 if (List.size() < 2)
1654 // If we have no section (e.g. common), just write out
1655 // individual spans for each symbol.
1657 for (const SymbolCU &Cur : List) {
1659 Span.Start = Cur.Sym;
1662 Spans[Cur.CU].push_back(Span);
1667 // Sort the symbols by offset within the section.
1668 std::sort(List.begin(), List.end(),
1669 [&](const SymbolCU &A, const SymbolCU &B) {
1670 unsigned IA = A.Sym ? Asm->OutStreamer.GetSymbolOrder(A.Sym) : 0;
1671 unsigned IB = B.Sym ? Asm->OutStreamer.GetSymbolOrder(B.Sym) : 0;
1673 // Symbols with no order assigned should be placed at the end.
1674 // (e.g. section end labels)
1682 // Build spans between each label.
1683 const MCSymbol *StartSym = List[0].Sym;
1684 for (size_t n = 1, e = List.size(); n < e; n++) {
1685 const SymbolCU &Prev = List[n - 1];
1686 const SymbolCU &Cur = List[n];
1688 // Try and build the longest span we can within the same CU.
1689 if (Cur.CU != Prev.CU) {
1691 Span.Start = StartSym;
1693 Spans[Prev.CU].push_back(Span);
1699 // Start the dwarf aranges section.
1700 Asm->OutStreamer.SwitchSection(
1701 Asm->getObjFileLowering().getDwarfARangesSection());
1703 unsigned PtrSize = Asm->getDataLayout().getPointerSize();
1705 // Build a list of CUs used.
1706 std::vector<DwarfCompileUnit *> CUs;
1707 for (const auto &it : Spans) {
1708 DwarfCompileUnit *CU = it.first;
1712 // Sort the CU list (again, to ensure consistent output order).
1713 std::sort(CUs.begin(), CUs.end(), [](const DwarfUnit *A, const DwarfUnit *B) {
1714 return A->getUniqueID() < B->getUniqueID();
1717 // Emit an arange table for each CU we used.
1718 for (DwarfCompileUnit *CU : CUs) {
1719 std::vector<ArangeSpan> &List = Spans[CU];
1721 // Describe the skeleton CU's offset and length, not the dwo file's.
1722 if (auto *Skel = CU->getSkeleton())
1725 // Emit size of content not including length itself.
1726 unsigned ContentSize =
1727 sizeof(int16_t) + // DWARF ARange version number
1728 sizeof(int32_t) + // Offset of CU in the .debug_info section
1729 sizeof(int8_t) + // Pointer Size (in bytes)
1730 sizeof(int8_t); // Segment Size (in bytes)
1732 unsigned TupleSize = PtrSize * 2;
1734 // 7.20 in the Dwarf specs requires the table to be aligned to a tuple.
1736 OffsetToAlignment(sizeof(int32_t) + ContentSize, TupleSize);
1738 ContentSize += Padding;
1739 ContentSize += (List.size() + 1) * TupleSize;
1741 // For each compile unit, write the list of spans it covers.
1742 Asm->OutStreamer.AddComment("Length of ARange Set");
1743 Asm->EmitInt32(ContentSize);
1744 Asm->OutStreamer.AddComment("DWARF Arange version number");
1745 Asm->EmitInt16(dwarf::DW_ARANGES_VERSION);
1746 Asm->OutStreamer.AddComment("Offset Into Debug Info Section");
1747 Asm->emitSectionOffset(CU->getLabelBegin());
1748 Asm->OutStreamer.AddComment("Address Size (in bytes)");
1749 Asm->EmitInt8(PtrSize);
1750 Asm->OutStreamer.AddComment("Segment Size (in bytes)");
1753 Asm->OutStreamer.EmitFill(Padding, 0xff);
1755 for (const ArangeSpan &Span : List) {
1756 Asm->EmitLabelReference(Span.Start, PtrSize);
1758 // Calculate the size as being from the span start to it's end.
1760 Asm->EmitLabelDifference(Span.End, Span.Start, PtrSize);
1762 // For symbols without an end marker (e.g. common), we
1763 // write a single arange entry containing just that one symbol.
1764 uint64_t Size = SymSize[Span.Start];
1768 Asm->OutStreamer.EmitIntValue(Size, PtrSize);
1772 Asm->OutStreamer.AddComment("ARange terminator");
1773 Asm->OutStreamer.EmitIntValue(0, PtrSize);
1774 Asm->OutStreamer.EmitIntValue(0, PtrSize);
1778 // Emit visible names into a debug ranges section.
1779 void DwarfDebug::emitDebugRanges() {
1780 // Start the dwarf ranges section.
1781 Asm->OutStreamer.SwitchSection(
1782 Asm->getObjFileLowering().getDwarfRangesSection());
1784 // Size for our labels.
1785 unsigned char Size = Asm->getDataLayout().getPointerSize();
1787 // Grab the specific ranges for the compile units in the module.
1788 for (const auto &I : CUMap) {
1789 DwarfCompileUnit *TheCU = I.second;
1791 if (auto *Skel = TheCU->getSkeleton())
1794 // Iterate over the misc ranges for the compile units in the module.
1795 for (const RangeSpanList &List : TheCU->getRangeLists()) {
1796 // Emit our symbol so we can find the beginning of the range.
1797 Asm->OutStreamer.EmitLabel(List.getSym());
1799 for (const RangeSpan &Range : List.getRanges()) {
1800 const MCSymbol *Begin = Range.getStart();
1801 const MCSymbol *End = Range.getEnd();
1802 assert(Begin && "Range without a begin symbol?");
1803 assert(End && "Range without an end symbol?");
1804 if (auto *Base = TheCU->getBaseAddress()) {
1805 Asm->EmitLabelDifference(Begin, Base, Size);
1806 Asm->EmitLabelDifference(End, Base, Size);
1808 Asm->OutStreamer.EmitSymbolValue(Begin, Size);
1809 Asm->OutStreamer.EmitSymbolValue(End, Size);
1813 // And terminate the list with two 0 values.
1814 Asm->OutStreamer.EmitIntValue(0, Size);
1815 Asm->OutStreamer.EmitIntValue(0, Size);
1820 // DWARF5 Experimental Separate Dwarf emitters.
1822 void DwarfDebug::initSkeletonUnit(const DwarfUnit &U, DIE &Die,
1823 std::unique_ptr<DwarfUnit> NewU) {
1824 NewU->addString(Die, dwarf::DW_AT_GNU_dwo_name,
1825 U.getCUNode()->getSplitDebugFilename());
1827 if (!CompilationDir.empty())
1828 NewU->addString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
1830 addGnuPubAttributes(*NewU, Die);
1832 SkeletonHolder.addUnit(std::move(NewU));
1835 // This DIE has the following attributes: DW_AT_comp_dir, DW_AT_stmt_list,
1836 // DW_AT_low_pc, DW_AT_high_pc, DW_AT_ranges, DW_AT_dwo_name, DW_AT_dwo_id,
1837 // DW_AT_addr_base, DW_AT_ranges_base.
1838 DwarfCompileUnit &DwarfDebug::constructSkeletonCU(const DwarfCompileUnit &CU) {
1840 auto OwnedUnit = make_unique<DwarfCompileUnit>(
1841 CU.getUniqueID(), CU.getCUNode(), Asm, this, &SkeletonHolder);
1842 DwarfCompileUnit &NewCU = *OwnedUnit;
1843 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoSection());
1845 NewCU.initStmtList();
1847 initSkeletonUnit(CU, NewCU.getUnitDie(), std::move(OwnedUnit));
1852 // Emit the .debug_info.dwo section for separated dwarf. This contains the
1853 // compile units that would normally be in debug_info.
1854 void DwarfDebug::emitDebugInfoDWO() {
1855 assert(useSplitDwarf() && "No split dwarf debug info?");
1856 // Don't emit relocations into the dwo file.
1857 InfoHolder.emitUnits(/* UseOffsets */ true);
1860 // Emit the .debug_abbrev.dwo section for separated dwarf. This contains the
1861 // abbreviations for the .debug_info.dwo section.
1862 void DwarfDebug::emitDebugAbbrevDWO() {
1863 assert(useSplitDwarf() && "No split dwarf?");
1864 InfoHolder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevDWOSection());
1867 void DwarfDebug::emitDebugLineDWO() {
1868 assert(useSplitDwarf() && "No split dwarf?");
1869 Asm->OutStreamer.SwitchSection(
1870 Asm->getObjFileLowering().getDwarfLineDWOSection());
1871 SplitTypeUnitFileTable.Emit(Asm->OutStreamer);
1874 // Emit the .debug_str.dwo section for separated dwarf. This contains the
1875 // string section and is identical in format to traditional .debug_str
1877 void DwarfDebug::emitDebugStrDWO() {
1878 assert(useSplitDwarf() && "No split dwarf?");
1879 const MCSection *OffSec =
1880 Asm->getObjFileLowering().getDwarfStrOffDWOSection();
1881 InfoHolder.emitStrings(Asm->getObjFileLowering().getDwarfStrDWOSection(),
1885 MCDwarfDwoLineTable *DwarfDebug::getDwoLineTable(const DwarfCompileUnit &CU) {
1886 if (!useSplitDwarf())
1889 SplitTypeUnitFileTable.setCompilationDir(CU.getCUNode()->getDirectory());
1890 return &SplitTypeUnitFileTable;
1893 static uint64_t makeTypeSignature(StringRef Identifier) {
1895 Hash.update(Identifier);
1896 // ... take the least significant 8 bytes and return those. Our MD5
1897 // implementation always returns its results in little endian, swap bytes
1899 MD5::MD5Result Result;
1901 return support::endian::read64le(Result + 8);
1904 void DwarfDebug::addDwarfTypeUnitType(DwarfCompileUnit &CU,
1905 StringRef Identifier, DIE &RefDie,
1906 const MDCompositeType *CTy) {
1907 // Fast path if we're building some type units and one has already used the
1908 // address pool we know we're going to throw away all this work anyway, so
1909 // don't bother building dependent types.
1910 if (!TypeUnitsUnderConstruction.empty() && AddrPool.hasBeenUsed())
1913 const DwarfTypeUnit *&TU = DwarfTypeUnits[CTy];
1915 CU.addDIETypeSignature(RefDie, *TU);
1919 bool TopLevelType = TypeUnitsUnderConstruction.empty();
1920 AddrPool.resetUsedFlag();
1922 auto OwnedUnit = make_unique<DwarfTypeUnit>(
1923 InfoHolder.getUnits().size() + TypeUnitsUnderConstruction.size(), CU, Asm,
1924 this, &InfoHolder, getDwoLineTable(CU));
1925 DwarfTypeUnit &NewTU = *OwnedUnit;
1926 DIE &UnitDie = NewTU.getUnitDie();
1928 TypeUnitsUnderConstruction.push_back(
1929 std::make_pair(std::move(OwnedUnit), CTy));
1931 NewTU.addUInt(UnitDie, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
1934 uint64_t Signature = makeTypeSignature(Identifier);
1935 NewTU.setTypeSignature(Signature);
1937 if (useSplitDwarf())
1938 NewTU.initSection(Asm->getObjFileLowering().getDwarfTypesDWOSection());
1940 CU.applyStmtList(UnitDie);
1942 Asm->getObjFileLowering().getDwarfTypesSection(Signature));
1945 NewTU.setType(NewTU.createTypeDIE(CTy));
1948 auto TypeUnitsToAdd = std::move(TypeUnitsUnderConstruction);
1949 TypeUnitsUnderConstruction.clear();
1951 // Types referencing entries in the address table cannot be placed in type
1953 if (AddrPool.hasBeenUsed()) {
1955 // Remove all the types built while building this type.
1956 // This is pessimistic as some of these types might not be dependent on
1957 // the type that used an address.
1958 for (const auto &TU : TypeUnitsToAdd)
1959 DwarfTypeUnits.erase(TU.second);
1961 // Construct this type in the CU directly.
1962 // This is inefficient because all the dependent types will be rebuilt
1963 // from scratch, including building them in type units, discovering that
1964 // they depend on addresses, throwing them out and rebuilding them.
1965 CU.constructTypeDIE(RefDie, cast<MDCompositeType>(CTy));
1969 // If the type wasn't dependent on fission addresses, finish adding the type
1970 // and all its dependent types.
1971 for (auto &TU : TypeUnitsToAdd)
1972 InfoHolder.addUnit(std::move(TU.first));
1974 CU.addDIETypeSignature(RefDie, NewTU);
1977 // Accelerator table mutators - add each name along with its companion
1978 // DIE to the proper table while ensuring that the name that we're going
1979 // to reference is in the string table. We do this since the names we
1980 // add may not only be identical to the names in the DIE.
1981 void DwarfDebug::addAccelName(StringRef Name, const DIE &Die) {
1982 if (!useDwarfAccelTables())
1984 AccelNames.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
1988 void DwarfDebug::addAccelObjC(StringRef Name, const DIE &Die) {
1989 if (!useDwarfAccelTables())
1991 AccelObjC.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
1995 void DwarfDebug::addAccelNamespace(StringRef Name, const DIE &Die) {
1996 if (!useDwarfAccelTables())
1998 AccelNamespace.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2002 void DwarfDebug::addAccelType(StringRef Name, const DIE &Die, char Flags) {
2003 if (!useDwarfAccelTables())
2005 AccelTypes.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),