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 "DwarfCompileUnit.h"
18 #include "DwarfExpression.h"
19 #include "DwarfUnit.h"
20 #include "llvm/ADT/STLExtras.h"
21 #include "llvm/ADT/Statistic.h"
22 #include "llvm/ADT/StringExtras.h"
23 #include "llvm/ADT/Triple.h"
24 #include "llvm/CodeGen/DIE.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/Support/raw_ostream.h"
49 #include "llvm/Target/TargetFrameLowering.h"
50 #include "llvm/Target/TargetLoweringObjectFile.h"
51 #include "llvm/Target/TargetMachine.h"
52 #include "llvm/Target/TargetOptions.h"
53 #include "llvm/Target/TargetRegisterInfo.h"
54 #include "llvm/Target/TargetSubtargetInfo.h"
57 #define DEBUG_TYPE "dwarfdebug"
60 DisableDebugInfoPrinting("disable-debug-info-print", cl::Hidden,
61 cl::desc("Disable debug info printing"));
63 static cl::opt<bool> UnknownLocations(
64 "use-unknown-locations", cl::Hidden,
65 cl::desc("Make an absence of debug location information explicit."),
69 GenerateGnuPubSections("generate-gnu-dwarf-pub-sections", cl::Hidden,
70 cl::desc("Generate GNU-style pubnames and pubtypes"),
73 static cl::opt<bool> GenerateARangeSection("generate-arange-section",
75 cl::desc("Generate dwarf aranges"),
79 enum DefaultOnOff { Default, Enable, Disable };
82 static cl::opt<DefaultOnOff>
83 DwarfAccelTables("dwarf-accel-tables", cl::Hidden,
84 cl::desc("Output prototype dwarf accelerator tables."),
85 cl::values(clEnumVal(Default, "Default for platform"),
86 clEnumVal(Enable, "Enabled"),
87 clEnumVal(Disable, "Disabled"), clEnumValEnd),
90 static cl::opt<DefaultOnOff>
91 SplitDwarf("split-dwarf", cl::Hidden,
92 cl::desc("Output DWARF5 split debug info."),
93 cl::values(clEnumVal(Default, "Default for platform"),
94 clEnumVal(Enable, "Enabled"),
95 clEnumVal(Disable, "Disabled"), clEnumValEnd),
98 static cl::opt<DefaultOnOff>
99 DwarfPubSections("generate-dwarf-pub-sections", cl::Hidden,
100 cl::desc("Generate DWARF pubnames and pubtypes sections"),
101 cl::values(clEnumVal(Default, "Default for platform"),
102 clEnumVal(Enable, "Enabled"),
103 clEnumVal(Disable, "Disabled"), clEnumValEnd),
106 static const char *const DWARFGroupName = "DWARF Emission";
107 static const char *const DbgTimerName = "DWARF Debug Writer";
109 void DebugLocDwarfExpression::EmitOp(uint8_t Op, const char *Comment) {
111 Op, Comment ? Twine(Comment) + " " + dwarf::OperationEncodingString(Op)
112 : dwarf::OperationEncodingString(Op));
115 void DebugLocDwarfExpression::EmitSigned(int64_t Value) {
116 BS.EmitSLEB128(Value, Twine(Value));
119 void DebugLocDwarfExpression::EmitUnsigned(uint64_t Value) {
120 BS.EmitULEB128(Value, Twine(Value));
123 bool DebugLocDwarfExpression::isFrameRegister(unsigned MachineReg) {
124 // This information is not available while emitting .debug_loc entries.
128 //===----------------------------------------------------------------------===//
130 /// resolve - Look in the DwarfDebug map for the MDNode that
131 /// corresponds to the reference.
132 template <typename T> T *DbgVariable::resolve(TypedDebugNodeRef<T> Ref) const {
133 return DD->resolve(Ref);
136 bool DbgVariable::isBlockByrefVariable() const {
137 assert(Var && "Invalid complex DbgVariable!");
138 return Var->getType()
139 .resolve(DD->getTypeIdentifierMap())
140 ->isBlockByrefStruct();
143 DIType DbgVariable::getType() const {
144 MDType *Ty = Var->getType().resolve(DD->getTypeIdentifierMap());
145 // FIXME: isBlockByrefVariable should be reformulated in terms of complex
146 // addresses instead.
147 if (Ty->isBlockByrefStruct()) {
148 /* Byref variables, in Blocks, are declared by the programmer as
149 "SomeType VarName;", but the compiler creates a
150 __Block_byref_x_VarName struct, and gives the variable VarName
151 either the struct, or a pointer to the struct, as its type. This
152 is necessary for various behind-the-scenes things the compiler
153 needs to do with by-reference variables in blocks.
155 However, as far as the original *programmer* is concerned, the
156 variable should still have type 'SomeType', as originally declared.
158 The following function dives into the __Block_byref_x_VarName
159 struct to find the original type of the variable. This will be
160 passed back to the code generating the type for the Debug
161 Information Entry for the variable 'VarName'. 'VarName' will then
162 have the original type 'SomeType' in its debug information.
164 The original type 'SomeType' will be the type of the field named
165 'VarName' inside the __Block_byref_x_VarName struct.
167 NOTE: In order for this to not completely fail on the debugger
168 side, the Debug Information Entry for the variable VarName needs to
169 have a DW_AT_location that tells the debugger how to unwind through
170 the pointers and __Block_byref_x_VarName struct to find the actual
171 value of the variable. The function addBlockByrefType does this. */
172 MDType *subType = Ty;
173 uint16_t tag = Ty->getTag();
175 if (tag == dwarf::DW_TAG_pointer_type)
176 subType = resolve(DITypeRef(cast<MDDerivedType>(Ty)->getBaseType()));
178 auto Elements = cast<MDCompositeTypeBase>(subType)->getElements();
179 for (unsigned i = 0, N = Elements.size(); i < N; ++i) {
180 auto *DT = cast<MDDerivedTypeBase>(Elements[i]);
181 if (getName() == DT->getName())
182 return resolve(DITypeRef(DT->getBaseType()));
188 static LLVM_CONSTEXPR DwarfAccelTable::Atom TypeAtoms[] = {
189 DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset, dwarf::DW_FORM_data4),
190 DwarfAccelTable::Atom(dwarf::DW_ATOM_die_tag, dwarf::DW_FORM_data2),
191 DwarfAccelTable::Atom(dwarf::DW_ATOM_type_flags, dwarf::DW_FORM_data1)};
193 DwarfDebug::DwarfDebug(AsmPrinter *A, Module *M)
194 : Asm(A), MMI(Asm->MMI), PrevLabel(nullptr),
195 InfoHolder(A, "info_string", DIEValueAllocator),
196 UsedNonDefaultText(false),
197 SkeletonHolder(A, "skel_string", DIEValueAllocator),
198 IsDarwin(Triple(A->getTargetTriple()).isOSDarwin()),
199 IsPS4(Triple(A->getTargetTriple()).isPS4()),
200 AccelNames(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
201 dwarf::DW_FORM_data4)),
202 AccelObjC(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
203 dwarf::DW_FORM_data4)),
204 AccelNamespace(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
205 dwarf::DW_FORM_data4)),
206 AccelTypes(TypeAtoms) {
211 // Turn on accelerator tables for Darwin by default, pubnames by
212 // default for non-Darwin/PS4, and handle split dwarf.
213 if (DwarfAccelTables == Default)
214 HasDwarfAccelTables = IsDarwin;
216 HasDwarfAccelTables = DwarfAccelTables == Enable;
218 if (SplitDwarf == Default)
219 HasSplitDwarf = false;
221 HasSplitDwarf = SplitDwarf == Enable;
223 if (DwarfPubSections == Default)
224 HasDwarfPubSections = !IsDarwin && !IsPS4;
226 HasDwarfPubSections = DwarfPubSections == Enable;
228 unsigned DwarfVersionNumber = Asm->TM.Options.MCOptions.DwarfVersion;
229 DwarfVersion = DwarfVersionNumber ? DwarfVersionNumber
230 : MMI->getModule()->getDwarfVersion();
232 // Darwin and PS4 use the standard TLS opcode (defined in DWARF 3).
233 // Everybody else uses GNU's.
234 UseGNUTLSOpcode = !(IsDarwin || IsPS4) || DwarfVersion < 3;
236 Asm->OutStreamer.getContext().setDwarfVersion(DwarfVersion);
239 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
244 // Define out of line so we don't have to include DwarfUnit.h in DwarfDebug.h.
245 DwarfDebug::~DwarfDebug() { }
247 static bool isObjCClass(StringRef Name) {
248 return Name.startswith("+") || Name.startswith("-");
251 static bool hasObjCCategory(StringRef Name) {
252 if (!isObjCClass(Name))
255 return Name.find(") ") != StringRef::npos;
258 static void getObjCClassCategory(StringRef In, StringRef &Class,
259 StringRef &Category) {
260 if (!hasObjCCategory(In)) {
261 Class = In.slice(In.find('[') + 1, In.find(' '));
266 Class = In.slice(In.find('[') + 1, In.find('('));
267 Category = In.slice(In.find('[') + 1, In.find(' '));
271 static StringRef getObjCMethodName(StringRef In) {
272 return In.slice(In.find(' ') + 1, In.find(']'));
275 // Add the various names to the Dwarf accelerator table names.
276 // TODO: Determine whether or not we should add names for programs
277 // that do not have a DW_AT_name or DW_AT_linkage_name field - this
278 // is only slightly different than the lookup of non-standard ObjC names.
279 void DwarfDebug::addSubprogramNames(DISubprogram SP, DIE &Die) {
280 if (!SP->isDefinition())
282 addAccelName(SP->getName(), Die);
284 // If the linkage name is different than the name, go ahead and output
285 // that as well into the name table.
286 if (SP->getLinkageName() != "" && SP->getName() != SP->getLinkageName())
287 addAccelName(SP->getLinkageName(), Die);
289 // If this is an Objective-C selector name add it to the ObjC accelerator
291 if (isObjCClass(SP->getName())) {
292 StringRef Class, Category;
293 getObjCClassCategory(SP->getName(), Class, Category);
294 addAccelObjC(Class, Die);
296 addAccelObjC(Category, Die);
297 // Also add the base method name to the name table.
298 addAccelName(getObjCMethodName(SP->getName()), Die);
302 /// isSubprogramContext - Return true if Context is either a subprogram
303 /// or another context nested inside a subprogram.
304 bool DwarfDebug::isSubprogramContext(const MDNode *Context) {
307 if (isa<MDSubprogram>(Context))
309 if (auto *T = dyn_cast<MDType>(Context))
310 return isSubprogramContext(resolve(T->getScope()));
314 /// Check whether we should create a DIE for the given Scope, return true
315 /// if we don't create a DIE (the corresponding DIE is null).
316 bool DwarfDebug::isLexicalScopeDIENull(LexicalScope *Scope) {
317 if (Scope->isAbstractScope())
320 // We don't create a DIE if there is no Range.
321 const SmallVectorImpl<InsnRange> &Ranges = Scope->getRanges();
325 if (Ranges.size() > 1)
328 // We don't create a DIE if we have a single Range and the end label
330 return !getLabelAfterInsn(Ranges.front().second);
333 template <typename Func> void forBothCUs(DwarfCompileUnit &CU, Func F) {
335 if (auto *SkelCU = CU.getSkeleton())
339 void DwarfDebug::constructAbstractSubprogramScopeDIE(LexicalScope *Scope) {
340 assert(Scope && Scope->getScopeNode());
341 assert(Scope->isAbstractScope());
342 assert(!Scope->getInlinedAt());
344 const MDNode *SP = Scope->getScopeNode();
346 ProcessedSPNodes.insert(SP);
348 // Find the subprogram's DwarfCompileUnit in the SPMap in case the subprogram
349 // was inlined from another compile unit.
350 auto &CU = SPMap[SP];
351 forBothCUs(*CU, [&](DwarfCompileUnit &CU) {
352 CU.constructAbstractSubprogramScopeDIE(Scope);
356 void DwarfDebug::addGnuPubAttributes(DwarfUnit &U, DIE &D) const {
357 if (!GenerateGnuPubSections)
360 U.addFlag(D, dwarf::DW_AT_GNU_pubnames);
363 // Create new DwarfCompileUnit for the given metadata node with tag
364 // DW_TAG_compile_unit.
365 DwarfCompileUnit &DwarfDebug::constructDwarfCompileUnit(DICompileUnit DIUnit) {
366 StringRef FN = DIUnit->getFilename();
367 CompilationDir = DIUnit->getDirectory();
369 auto OwnedUnit = make_unique<DwarfCompileUnit>(
370 InfoHolder.getUnits().size(), DIUnit, Asm, this, &InfoHolder);
371 DwarfCompileUnit &NewCU = *OwnedUnit;
372 DIE &Die = NewCU.getUnitDie();
373 InfoHolder.addUnit(std::move(OwnedUnit));
375 NewCU.setSkeleton(constructSkeletonCU(NewCU));
377 // LTO with assembly output shares a single line table amongst multiple CUs.
378 // To avoid the compilation directory being ambiguous, let the line table
379 // explicitly describe the directory of all files, never relying on the
380 // compilation directory.
381 if (!Asm->OutStreamer.hasRawTextSupport() || SingleCU)
382 Asm->OutStreamer.getContext().setMCLineTableCompilationDir(
383 NewCU.getUniqueID(), CompilationDir);
385 NewCU.addString(Die, dwarf::DW_AT_producer, DIUnit->getProducer());
386 NewCU.addUInt(Die, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
387 DIUnit->getSourceLanguage());
388 NewCU.addString(Die, dwarf::DW_AT_name, FN);
390 if (!useSplitDwarf()) {
391 NewCU.initStmtList();
393 // If we're using split dwarf the compilation dir is going to be in the
394 // skeleton CU and so we don't need to duplicate it here.
395 if (!CompilationDir.empty())
396 NewCU.addString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
398 addGnuPubAttributes(NewCU, Die);
401 if (DIUnit->isOptimized())
402 NewCU.addFlag(Die, dwarf::DW_AT_APPLE_optimized);
404 StringRef Flags = DIUnit->getFlags();
406 NewCU.addString(Die, dwarf::DW_AT_APPLE_flags, Flags);
408 if (unsigned RVer = DIUnit->getRuntimeVersion())
409 NewCU.addUInt(Die, dwarf::DW_AT_APPLE_major_runtime_vers,
410 dwarf::DW_FORM_data1, RVer);
413 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoDWOSection());
415 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoSection());
417 CUMap.insert(std::make_pair(DIUnit, &NewCU));
418 CUDieMap.insert(std::make_pair(&Die, &NewCU));
422 void DwarfDebug::constructAndAddImportedEntityDIE(DwarfCompileUnit &TheCU,
424 DIImportedEntity Module = cast<MDImportedEntity>(N);
425 if (DIE *D = TheCU.getOrCreateContextDIE(Module->getScope()))
426 D->addChild(TheCU.constructImportedEntityDIE(Module));
429 // Emit all Dwarf sections that should come prior to the content. Create
430 // global DIEs and emit initial debug info sections. This is invoked by
431 // the target AsmPrinter.
432 void DwarfDebug::beginModule() {
433 if (DisableDebugInfoPrinting)
436 const Module *M = MMI->getModule();
438 FunctionDIs = makeSubprogramMap(*M);
440 NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
443 TypeIdentifierMap = generateDITypeIdentifierMap(CU_Nodes);
445 SingleCU = CU_Nodes->getNumOperands() == 1;
447 for (MDNode *N : CU_Nodes->operands()) {
448 DICompileUnit CUNode = cast<MDCompileUnit>(N);
449 DwarfCompileUnit &CU = constructDwarfCompileUnit(CUNode);
450 for (auto *IE : CUNode->getImportedEntities())
451 ScopesWithImportedEntities.push_back(std::make_pair(IE->getScope(), IE));
452 // Stable sort to preserve the order of appearance of imported entities.
453 // This is to avoid out-of-order processing of interdependent declarations
454 // within the same scope, e.g. { namespace A = base; namespace B = A; }
455 std::stable_sort(ScopesWithImportedEntities.begin(),
456 ScopesWithImportedEntities.end(), less_first());
457 for (auto *GV : CUNode->getGlobalVariables())
458 CU.getOrCreateGlobalVariableDIE(GV);
459 for (auto *SP : CUNode->getSubprograms())
460 SPMap.insert(std::make_pair(SP, &CU));
461 for (DIType Ty : CUNode->getEnumTypes()) {
462 // The enum types array by design contains pointers to
463 // MDNodes rather than DIRefs. Unique them here.
464 DIType UniqueTy = cast<MDType>(resolve(Ty->getRef()));
465 CU.getOrCreateTypeDIE(UniqueTy);
467 for (DIType Ty : CUNode->getRetainedTypes()) {
468 // The retained types array by design contains pointers to
469 // MDNodes rather than DIRefs. Unique them here.
470 DIType UniqueTy = cast<MDType>(resolve(Ty->getRef()));
471 CU.getOrCreateTypeDIE(UniqueTy);
473 // Emit imported_modules last so that the relevant context is already
475 for (auto *IE : CUNode->getImportedEntities())
476 constructAndAddImportedEntityDIE(CU, IE);
479 // Tell MMI that we have debug info.
480 MMI->setDebugInfoAvailability(true);
483 void DwarfDebug::finishVariableDefinitions() {
484 for (const auto &Var : ConcreteVariables) {
485 DIE *VariableDie = Var->getDIE();
487 // FIXME: Consider the time-space tradeoff of just storing the unit pointer
488 // in the ConcreteVariables list, rather than looking it up again here.
489 // DIE::getUnit isn't simple - it walks parent pointers, etc.
490 DwarfCompileUnit *Unit = lookupUnit(VariableDie->getUnit());
492 DbgVariable *AbsVar = getExistingAbstractVariable(
493 InlinedVariable(Var->getVariable(), Var->getInlinedAt()));
494 if (AbsVar && AbsVar->getDIE()) {
495 Unit->addDIEEntry(*VariableDie, dwarf::DW_AT_abstract_origin,
498 Unit->applyVariableAttributes(*Var, *VariableDie);
502 void DwarfDebug::finishSubprogramDefinitions() {
503 for (const auto &P : SPMap)
504 forBothCUs(*P.second, [&](DwarfCompileUnit &CU) {
505 CU.finishSubprogramDefinition(cast<MDSubprogram>(P.first));
510 // Collect info for variables that were optimized out.
511 void DwarfDebug::collectDeadVariables() {
512 const Module *M = MMI->getModule();
514 if (NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu")) {
515 for (MDNode *N : CU_Nodes->operands()) {
516 DICompileUnit TheCU = cast<MDCompileUnit>(N);
517 // Construct subprogram DIE and add variables DIEs.
518 DwarfCompileUnit *SPCU =
519 static_cast<DwarfCompileUnit *>(CUMap.lookup(TheCU));
520 assert(SPCU && "Unable to find Compile Unit!");
521 for (auto *SP : TheCU->getSubprograms()) {
522 if (ProcessedSPNodes.count(SP) != 0)
524 SPCU->collectDeadVariables(SP);
530 void DwarfDebug::finalizeModuleInfo() {
531 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
533 finishSubprogramDefinitions();
535 finishVariableDefinitions();
537 // Collect info for variables that were optimized out.
538 collectDeadVariables();
540 // Handle anything that needs to be done on a per-unit basis after
541 // all other generation.
542 for (const auto &P : CUMap) {
543 auto &TheCU = *P.second;
544 // Emit DW_AT_containing_type attribute to connect types with their
545 // vtable holding type.
546 TheCU.constructContainingTypeDIEs();
548 // Add CU specific attributes if we need to add any.
549 // If we're splitting the dwarf out now that we've got the entire
550 // CU then add the dwo id to it.
551 auto *SkCU = TheCU.getSkeleton();
552 if (useSplitDwarf()) {
553 // Emit a unique identifier for this CU.
554 uint64_t ID = DIEHash(Asm).computeCUSignature(TheCU.getUnitDie());
555 TheCU.addUInt(TheCU.getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
556 dwarf::DW_FORM_data8, ID);
557 SkCU->addUInt(SkCU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
558 dwarf::DW_FORM_data8, ID);
560 // We don't keep track of which addresses are used in which CU so this
561 // is a bit pessimistic under LTO.
562 if (!AddrPool.isEmpty()) {
563 const MCSymbol *Sym = TLOF.getDwarfAddrSection()->getBeginSymbol();
564 SkCU->addSectionLabel(SkCU->getUnitDie(), dwarf::DW_AT_GNU_addr_base,
567 if (!SkCU->getRangeLists().empty()) {
568 const MCSymbol *Sym = TLOF.getDwarfRangesSection()->getBeginSymbol();
569 SkCU->addSectionLabel(SkCU->getUnitDie(), dwarf::DW_AT_GNU_ranges_base,
574 // If we have code split among multiple sections or non-contiguous
575 // ranges of code then emit a DW_AT_ranges attribute on the unit that will
576 // remain in the .o file, otherwise add a DW_AT_low_pc.
577 // FIXME: We should use ranges allow reordering of code ala
578 // .subsections_via_symbols in mach-o. This would mean turning on
579 // ranges for all subprogram DIEs for mach-o.
580 DwarfCompileUnit &U = SkCU ? *SkCU : TheCU;
581 if (unsigned NumRanges = TheCU.getRanges().size()) {
583 // A DW_AT_low_pc attribute may also be specified in combination with
584 // DW_AT_ranges to specify the default base address for use in
585 // location lists (see Section 2.6.2) and range lists (see Section
587 U.addUInt(U.getUnitDie(), dwarf::DW_AT_low_pc, dwarf::DW_FORM_addr, 0);
589 TheCU.setBaseAddress(TheCU.getRanges().front().getStart());
590 U.attachRangesOrLowHighPC(U.getUnitDie(), TheCU.takeRanges());
594 // Compute DIE offsets and sizes.
595 InfoHolder.computeSizeAndOffsets();
597 SkeletonHolder.computeSizeAndOffsets();
600 // Emit all Dwarf sections that should come after the content.
601 void DwarfDebug::endModule() {
602 assert(CurFn == nullptr);
603 assert(CurMI == nullptr);
605 // If we aren't actually generating debug info (check beginModule -
606 // conditionalized on !DisableDebugInfoPrinting and the presence of the
607 // llvm.dbg.cu metadata node)
608 if (!MMI->hasDebugInfo())
611 // Finalize the debug info for the module.
612 finalizeModuleInfo();
619 // Emit info into a debug loc section.
622 // Corresponding abbreviations into a abbrev section.
625 // Emit all the DIEs into a debug info section.
628 // Emit info into a debug aranges section.
629 if (GenerateARangeSection)
632 // Emit info into a debug ranges section.
635 if (useSplitDwarf()) {
638 emitDebugAbbrevDWO();
640 // Emit DWO addresses.
641 AddrPool.emit(*Asm, Asm->getObjFileLowering().getDwarfAddrSection());
644 // Emit info into the dwarf accelerator table sections.
645 if (useDwarfAccelTables()) {
648 emitAccelNamespaces();
652 // Emit the pubnames and pubtypes sections if requested.
653 if (HasDwarfPubSections) {
654 emitDebugPubNames(GenerateGnuPubSections);
655 emitDebugPubTypes(GenerateGnuPubSections);
660 AbstractVariables.clear();
663 // Find abstract variable, if any, associated with Var.
664 DbgVariable *DwarfDebug::getExistingAbstractVariable(InlinedVariable IV,
665 DIVariable &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) {
676 return getExistingAbstractVariable(IV, Cleansed);
679 void DwarfDebug::createAbstractVariable(const DIVariable &Var,
680 LexicalScope *Scope) {
681 auto AbsDbgVariable =
682 make_unique<DbgVariable>(Var, nullptr, DIExpression(), this);
683 InfoHolder.addScopeVariable(Scope, AbsDbgVariable.get());
684 AbstractVariables[Var] = std::move(AbsDbgVariable);
687 void DwarfDebug::ensureAbstractVariableIsCreated(InlinedVariable IV,
688 const MDNode *ScopeNode) {
690 if (getExistingAbstractVariable(IV, Cleansed))
693 createAbstractVariable(Cleansed, LScopes.getOrCreateAbstractScope(
694 cast<MDLocalScope>(ScopeNode)));
697 void DwarfDebug::ensureAbstractVariableIsCreatedIfScoped(
698 InlinedVariable IV, const MDNode *ScopeNode) {
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 DIExpression 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 MDNode *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(DIExpression P1, DIExpression 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 DIExpression 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, DISubprogram SP,
877 DenseSet<InlinedVariable> &Processed) {
878 // Grab the variable info that was squirreled away in the MMI side-table.
879 collectVariableInfoFromMMITable(Processed);
881 for (const auto &I : DbgValues) {
882 InlinedVariable IV = I.first;
883 if (Processed.count(IV))
886 // Instruction ranges, specifying where IV is accessible.
887 const auto &Ranges = I.second;
891 LexicalScope *Scope = nullptr;
892 if (const MDLocation *IA = IV.second)
893 Scope = LScopes.findInlinedScope(IV.first->getScope(), IA);
895 Scope = LScopes.findLexicalScope(IV.first->getScope());
896 // If variable scope is not found then skip this variable.
900 Processed.insert(IV);
901 const MachineInstr *MInsn = Ranges.front().first;
902 assert(MInsn->isDebugValue() && "History must begin with debug value");
903 ensureAbstractVariableIsCreatedIfScoped(IV, Scope->getScopeNode());
904 ConcreteVariables.push_back(make_unique<DbgVariable>(MInsn, this));
905 DbgVariable *RegVar = ConcreteVariables.back().get();
906 InfoHolder.addScopeVariable(Scope, RegVar);
908 // Check if the first DBG_VALUE is valid for the rest of the function.
909 if (Ranges.size() == 1 && Ranges.front().second == nullptr)
912 // Handle multiple DBG_VALUE instructions describing one variable.
913 RegVar->setDotDebugLocOffset(DotDebugLocEntries.size());
915 DotDebugLocEntries.resize(DotDebugLocEntries.size() + 1);
916 DebugLocList &LocList = DotDebugLocEntries.back();
918 LocList.Label = Asm->createTempSymbol("debug_loc");
920 // Build the location list for this variable.
921 buildLocationList(LocList.List, Ranges);
923 // If the variable has an MDBasicType, extract it. Basic types cannot have
924 // unique identifiers, so don't bother resolving the type with the
926 const MDBasicType *BT = dyn_cast<MDBasicType>(
927 static_cast<const Metadata *>(IV.first->getType()));
929 // Finalize the entry by lowering it into a DWARF bytestream.
930 for (auto &Entry : LocList.List)
931 Entry.finalize(*Asm, BT);
934 // Collect info for variables that were optimized out.
935 for (DIVariable DV : SP->getVariables()) {
936 if (!Processed.insert(InlinedVariable(DV, nullptr)).second)
938 if (LexicalScope *Scope = LScopes.findLexicalScope(DV->getScope())) {
939 ensureAbstractVariableIsCreatedIfScoped(InlinedVariable(DV, nullptr),
940 Scope->getScopeNode());
942 ConcreteVariables.push_back(
943 make_unique<DbgVariable>(DV, nullptr, NoExpr, this));
944 InfoHolder.addScopeVariable(Scope, ConcreteVariables.back().get());
949 // Return Label preceding the instruction.
950 MCSymbol *DwarfDebug::getLabelBeforeInsn(const MachineInstr *MI) {
951 MCSymbol *Label = LabelsBeforeInsn.lookup(MI);
952 assert(Label && "Didn't insert label before instruction");
956 // Return Label immediately following the instruction.
957 MCSymbol *DwarfDebug::getLabelAfterInsn(const MachineInstr *MI) {
958 return LabelsAfterInsn.lookup(MI);
961 // Process beginning of an instruction.
962 void DwarfDebug::beginInstruction(const MachineInstr *MI) {
963 assert(CurMI == nullptr);
965 // Check if source location changes, but ignore DBG_VALUE locations.
966 if (!MI->isDebugValue()) {
967 DebugLoc DL = MI->getDebugLoc();
968 if (DL != PrevInstLoc) {
972 if (DL == PrologEndLoc) {
973 Flags |= DWARF2_FLAG_PROLOGUE_END;
974 PrologEndLoc = DebugLoc();
975 Flags |= DWARF2_FLAG_IS_STMT;
978 Asm->OutStreamer.getContext().getCurrentDwarfLoc().getLine())
979 Flags |= DWARF2_FLAG_IS_STMT;
981 const MDNode *Scope = DL.getScope();
982 recordSourceLine(DL.getLine(), DL.getCol(), Scope, Flags);
983 } else if (UnknownLocations) {
985 recordSourceLine(0, 0, nullptr, 0);
990 // Insert labels where requested.
991 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
992 LabelsBeforeInsn.find(MI);
995 if (I == LabelsBeforeInsn.end())
998 // Label already assigned.
1003 PrevLabel = MMI->getContext().CreateTempSymbol();
1004 Asm->OutStreamer.EmitLabel(PrevLabel);
1006 I->second = PrevLabel;
1009 // Process end of an instruction.
1010 void DwarfDebug::endInstruction() {
1011 assert(CurMI != nullptr);
1012 // Don't create a new label after DBG_VALUE instructions.
1013 // They don't generate code.
1014 if (!CurMI->isDebugValue())
1015 PrevLabel = nullptr;
1017 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1018 LabelsAfterInsn.find(CurMI);
1022 if (I == LabelsAfterInsn.end())
1025 // Label already assigned.
1029 // We need a label after this instruction.
1031 PrevLabel = MMI->getContext().CreateTempSymbol();
1032 Asm->OutStreamer.EmitLabel(PrevLabel);
1034 I->second = PrevLabel;
1037 // Each LexicalScope has first instruction and last instruction to mark
1038 // beginning and end of a scope respectively. Create an inverse map that list
1039 // scopes starts (and ends) with an instruction. One instruction may start (or
1040 // end) multiple scopes. Ignore scopes that are not reachable.
1041 void DwarfDebug::identifyScopeMarkers() {
1042 SmallVector<LexicalScope *, 4> WorkList;
1043 WorkList.push_back(LScopes.getCurrentFunctionScope());
1044 while (!WorkList.empty()) {
1045 LexicalScope *S = WorkList.pop_back_val();
1047 const SmallVectorImpl<LexicalScope *> &Children = S->getChildren();
1048 if (!Children.empty())
1049 WorkList.append(Children.begin(), Children.end());
1051 if (S->isAbstractScope())
1054 for (const InsnRange &R : S->getRanges()) {
1055 assert(R.first && "InsnRange does not have first instruction!");
1056 assert(R.second && "InsnRange does not have second instruction!");
1057 requestLabelBeforeInsn(R.first);
1058 requestLabelAfterInsn(R.second);
1063 static DebugLoc findPrologueEndLoc(const MachineFunction *MF) {
1064 // First known non-DBG_VALUE and non-frame setup location marks
1065 // the beginning of the function body.
1066 for (const auto &MBB : *MF)
1067 for (const auto &MI : MBB)
1068 if (!MI.isDebugValue() && !MI.getFlag(MachineInstr::FrameSetup) &&
1070 // Did the target forget to set the FrameSetup flag for CFI insns?
1071 assert(!MI.isCFIInstruction() &&
1072 "First non-frame-setup instruction is a CFI instruction.");
1073 return MI.getDebugLoc();
1078 // Gather pre-function debug information. Assumes being called immediately
1079 // after the function entry point has been emitted.
1080 void DwarfDebug::beginFunction(const MachineFunction *MF) {
1083 // If there's no debug info for the function we're not going to do anything.
1084 if (!MMI->hasDebugInfo())
1087 auto DI = FunctionDIs.find(MF->getFunction());
1088 if (DI == FunctionDIs.end())
1091 // Grab the lexical scopes for the function, if we don't have any of those
1092 // then we're not going to be able to do anything.
1093 LScopes.initialize(*MF);
1094 if (LScopes.empty())
1097 assert(DbgValues.empty() && "DbgValues map wasn't cleaned!");
1099 // Make sure that each lexical scope will have a begin/end label.
1100 identifyScopeMarkers();
1102 // Set DwarfDwarfCompileUnitID in MCContext to the Compile Unit this function
1103 // belongs to so that we add to the correct per-cu line table in the
1105 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1106 // FnScope->getScopeNode() and DI->second should represent the same function,
1107 // though they may not be the same MDNode due to inline functions merged in
1108 // LTO where the debug info metadata still differs (either due to distinct
1109 // written differences - two versions of a linkonce_odr function
1110 // written/copied into two separate files, or some sub-optimal metadata that
1111 // isn't structurally identical (see: file path/name info from clang, which
1112 // includes the directory of the cpp file being built, even when the file name
1113 // is absolute (such as an <> lookup header)))
1114 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1115 assert(TheCU && "Unable to find compile unit!");
1116 if (Asm->OutStreamer.hasRawTextSupport())
1117 // Use a single line table if we are generating assembly.
1118 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1120 Asm->OutStreamer.getContext().setDwarfCompileUnitID(TheCU->getUniqueID());
1122 // Calculate history for local variables.
1123 calculateDbgValueHistory(MF, Asm->MF->getSubtarget().getRegisterInfo(),
1126 // Request labels for the full history.
1127 for (const auto &I : DbgValues) {
1128 const auto &Ranges = I.second;
1132 // The first mention of a function argument gets the CurrentFnBegin
1133 // label, so arguments are visible when breaking at function entry.
1134 DIVariable DIVar = Ranges.front().first->getDebugVariable();
1135 if (DIVar->getTag() == dwarf::DW_TAG_arg_variable &&
1136 getDISubprogram(DIVar->getScope())->describes(MF->getFunction())) {
1137 LabelsBeforeInsn[Ranges.front().first] = Asm->getFunctionBegin();
1138 if (Ranges.front().first->getDebugExpression()->isBitPiece()) {
1139 // Mark all non-overlapping initial pieces.
1140 for (auto I = Ranges.begin(); I != Ranges.end(); ++I) {
1141 DIExpression Piece = I->first->getDebugExpression();
1142 if (std::all_of(Ranges.begin(), I,
1143 [&](DbgValueHistoryMap::InstrRange Pred) {
1144 return !piecesOverlap(Piece, Pred.first->getDebugExpression());
1146 LabelsBeforeInsn[I->first] = Asm->getFunctionBegin();
1153 for (const auto &Range : Ranges) {
1154 requestLabelBeforeInsn(Range.first);
1156 requestLabelAfterInsn(Range.second);
1160 PrevInstLoc = DebugLoc();
1161 PrevLabel = Asm->getFunctionBegin();
1163 // Record beginning of function.
1164 PrologEndLoc = findPrologueEndLoc(MF);
1165 if (MDLocation *L = PrologEndLoc) {
1166 // We'd like to list the prologue as "not statements" but GDB behaves
1167 // poorly if we do that. Revisit this with caution/GDB (7.5+) testing.
1168 auto *SP = L->getInlinedAtScope()->getSubprogram();
1169 recordSourceLine(SP->getScopeLine(), 0, SP, DWARF2_FLAG_IS_STMT);
1173 // Gather and emit post-function debug information.
1174 void DwarfDebug::endFunction(const MachineFunction *MF) {
1175 assert(CurFn == MF &&
1176 "endFunction should be called with the same function as beginFunction");
1178 if (!MMI->hasDebugInfo() || LScopes.empty() ||
1179 !FunctionDIs.count(MF->getFunction())) {
1180 // If we don't have a lexical scope for this function then there will
1181 // be a hole in the range information. Keep note of this by setting the
1182 // previously used section to nullptr.
1188 // Set DwarfDwarfCompileUnitID in MCContext to default value.
1189 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1191 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1192 DISubprogram SP = cast<MDSubprogram>(FnScope->getScopeNode());
1193 DwarfCompileUnit &TheCU = *SPMap.lookup(SP);
1195 DenseSet<InlinedVariable> ProcessedVars;
1196 collectVariableInfo(TheCU, SP, ProcessedVars);
1198 // Add the range of this function to the list of ranges for the CU.
1199 TheCU.addRange(RangeSpan(Asm->getFunctionBegin(), Asm->getFunctionEnd()));
1201 // Under -gmlt, skip building the subprogram if there are no inlined
1202 // subroutines inside it.
1203 if (TheCU.getCUNode()->getEmissionKind() == DIBuilder::LineTablesOnly &&
1204 LScopes.getAbstractScopesList().empty() && !IsDarwin) {
1205 assert(InfoHolder.getScopeVariables().empty());
1206 assert(DbgValues.empty());
1207 // FIXME: This wouldn't be true in LTO with a -g (with inlining) CU followed
1208 // by a -gmlt CU. Add a test and remove this assertion.
1209 assert(AbstractVariables.empty());
1210 LabelsBeforeInsn.clear();
1211 LabelsAfterInsn.clear();
1212 PrevLabel = nullptr;
1218 size_t NumAbstractScopes = LScopes.getAbstractScopesList().size();
1220 // Construct abstract scopes.
1221 for (LexicalScope *AScope : LScopes.getAbstractScopesList()) {
1222 DISubprogram SP = cast<MDSubprogram>(AScope->getScopeNode());
1223 // Collect info for variables that were optimized out.
1224 for (DIVariable DV : SP->getVariables()) {
1225 if (!ProcessedVars.insert(InlinedVariable(DV, nullptr)).second)
1227 ensureAbstractVariableIsCreated(InlinedVariable(DV, nullptr),
1229 assert(LScopes.getAbstractScopesList().size() == NumAbstractScopes
1230 && "ensureAbstractVariableIsCreated inserted abstract scopes");
1232 constructAbstractSubprogramScopeDIE(AScope);
1235 TheCU.constructSubprogramScopeDIE(FnScope);
1236 if (auto *SkelCU = TheCU.getSkeleton())
1237 if (!LScopes.getAbstractScopesList().empty())
1238 SkelCU->constructSubprogramScopeDIE(FnScope);
1241 // Ownership of DbgVariables is a bit subtle - ScopeVariables owns all the
1242 // DbgVariables except those that are also in AbstractVariables (since they
1243 // can be used cross-function)
1244 InfoHolder.getScopeVariables().clear();
1246 LabelsBeforeInsn.clear();
1247 LabelsAfterInsn.clear();
1248 PrevLabel = nullptr;
1252 // Register a source line with debug info. Returns the unique label that was
1253 // emitted and which provides correspondence to the source line list.
1254 void DwarfDebug::recordSourceLine(unsigned Line, unsigned Col, const MDNode *S,
1259 unsigned Discriminator = 0;
1260 if (auto *Scope = cast_or_null<MDScope>(S)) {
1261 Fn = Scope->getFilename();
1262 Dir = Scope->getDirectory();
1263 if (auto *LBF = dyn_cast<MDLexicalBlockFile>(Scope))
1264 Discriminator = LBF->getDiscriminator();
1266 unsigned CUID = Asm->OutStreamer.getContext().getDwarfCompileUnitID();
1267 Src = static_cast<DwarfCompileUnit &>(*InfoHolder.getUnits()[CUID])
1268 .getOrCreateSourceID(Fn, Dir);
1270 Asm->OutStreamer.EmitDwarfLocDirective(Src, Line, Col, Flags, 0,
1274 //===----------------------------------------------------------------------===//
1276 //===----------------------------------------------------------------------===//
1278 // Emit the debug info section.
1279 void DwarfDebug::emitDebugInfo() {
1280 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1281 Holder.emitUnits(/* UseOffsets */ false);
1284 // Emit the abbreviation section.
1285 void DwarfDebug::emitAbbreviations() {
1286 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1288 Holder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevSection());
1291 void DwarfDebug::emitAccel(DwarfAccelTable &Accel, const MCSection *Section,
1292 StringRef TableName) {
1293 Accel.FinalizeTable(Asm, TableName);
1294 Asm->OutStreamer.SwitchSection(Section);
1296 // Emit the full data.
1297 Accel.emit(Asm, Section->getBeginSymbol(), this);
1300 // Emit visible names into a hashed accelerator table section.
1301 void DwarfDebug::emitAccelNames() {
1302 emitAccel(AccelNames, Asm->getObjFileLowering().getDwarfAccelNamesSection(),
1306 // Emit objective C classes and categories into a hashed accelerator table
1308 void DwarfDebug::emitAccelObjC() {
1309 emitAccel(AccelObjC, Asm->getObjFileLowering().getDwarfAccelObjCSection(),
1313 // Emit namespace dies into a hashed accelerator table.
1314 void DwarfDebug::emitAccelNamespaces() {
1315 emitAccel(AccelNamespace,
1316 Asm->getObjFileLowering().getDwarfAccelNamespaceSection(),
1320 // Emit type dies into a hashed accelerator table.
1321 void DwarfDebug::emitAccelTypes() {
1322 emitAccel(AccelTypes, Asm->getObjFileLowering().getDwarfAccelTypesSection(),
1326 // Public name handling.
1327 // The format for the various pubnames:
1329 // dwarf pubnames - offset/name pairs where the offset is the offset into the CU
1330 // for the DIE that is named.
1332 // gnu pubnames - offset/index value/name tuples where the offset is the offset
1333 // into the CU and the index value is computed according to the type of value
1334 // for the DIE that is named.
1336 // For type units the offset is the offset of the skeleton DIE. For split dwarf
1337 // it's the offset within the debug_info/debug_types dwo section, however, the
1338 // reference in the pubname header doesn't change.
1340 /// computeIndexValue - Compute the gdb index value for the DIE and CU.
1341 static dwarf::PubIndexEntryDescriptor computeIndexValue(DwarfUnit *CU,
1343 dwarf::GDBIndexEntryLinkage Linkage = dwarf::GIEL_STATIC;
1345 // We could have a specification DIE that has our most of our knowledge,
1346 // look for that now.
1347 DIEValue *SpecVal = Die->findAttribute(dwarf::DW_AT_specification);
1349 DIE &SpecDIE = cast<DIEEntry>(SpecVal)->getEntry();
1350 if (SpecDIE.findAttribute(dwarf::DW_AT_external))
1351 Linkage = dwarf::GIEL_EXTERNAL;
1352 } else if (Die->findAttribute(dwarf::DW_AT_external))
1353 Linkage = dwarf::GIEL_EXTERNAL;
1355 switch (Die->getTag()) {
1356 case dwarf::DW_TAG_class_type:
1357 case dwarf::DW_TAG_structure_type:
1358 case dwarf::DW_TAG_union_type:
1359 case dwarf::DW_TAG_enumeration_type:
1360 return dwarf::PubIndexEntryDescriptor(
1361 dwarf::GIEK_TYPE, CU->getLanguage() != dwarf::DW_LANG_C_plus_plus
1362 ? dwarf::GIEL_STATIC
1363 : dwarf::GIEL_EXTERNAL);
1364 case dwarf::DW_TAG_typedef:
1365 case dwarf::DW_TAG_base_type:
1366 case dwarf::DW_TAG_subrange_type:
1367 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_TYPE, dwarf::GIEL_STATIC);
1368 case dwarf::DW_TAG_namespace:
1369 return dwarf::GIEK_TYPE;
1370 case dwarf::DW_TAG_subprogram:
1371 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_FUNCTION, Linkage);
1372 case dwarf::DW_TAG_variable:
1373 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE, Linkage);
1374 case dwarf::DW_TAG_enumerator:
1375 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE,
1376 dwarf::GIEL_STATIC);
1378 return dwarf::GIEK_NONE;
1382 /// emitDebugPubNames - Emit visible names into a debug pubnames section.
1384 void DwarfDebug::emitDebugPubNames(bool GnuStyle) {
1385 const MCSection *PSec =
1386 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubNamesSection()
1387 : Asm->getObjFileLowering().getDwarfPubNamesSection();
1389 emitDebugPubSection(GnuStyle, PSec, "Names",
1390 &DwarfCompileUnit::getGlobalNames);
1393 void DwarfDebug::emitDebugPubSection(
1394 bool GnuStyle, const MCSection *PSec, StringRef Name,
1395 const StringMap<const DIE *> &(DwarfCompileUnit::*Accessor)() const) {
1396 for (const auto &NU : CUMap) {
1397 DwarfCompileUnit *TheU = NU.second;
1399 const auto &Globals = (TheU->*Accessor)();
1401 if (Globals.empty())
1404 if (auto *Skeleton = TheU->getSkeleton())
1407 // Start the dwarf pubnames section.
1408 Asm->OutStreamer.SwitchSection(PSec);
1411 Asm->OutStreamer.AddComment("Length of Public " + Name + " Info");
1412 MCSymbol *BeginLabel = Asm->createTempSymbol("pub" + Name + "_begin");
1413 MCSymbol *EndLabel = Asm->createTempSymbol("pub" + Name + "_end");
1414 Asm->EmitLabelDifference(EndLabel, BeginLabel, 4);
1416 Asm->OutStreamer.EmitLabel(BeginLabel);
1418 Asm->OutStreamer.AddComment("DWARF Version");
1419 Asm->EmitInt16(dwarf::DW_PUBNAMES_VERSION);
1421 Asm->OutStreamer.AddComment("Offset of Compilation Unit Info");
1422 Asm->emitSectionOffset(TheU->getLabelBegin());
1424 Asm->OutStreamer.AddComment("Compilation Unit Length");
1425 Asm->EmitInt32(TheU->getLength());
1427 // Emit the pubnames for this compilation unit.
1428 for (const auto &GI : Globals) {
1429 const char *Name = GI.getKeyData();
1430 const DIE *Entity = GI.second;
1432 Asm->OutStreamer.AddComment("DIE offset");
1433 Asm->EmitInt32(Entity->getOffset());
1436 dwarf::PubIndexEntryDescriptor Desc = computeIndexValue(TheU, Entity);
1437 Asm->OutStreamer.AddComment(
1438 Twine("Kind: ") + dwarf::GDBIndexEntryKindString(Desc.Kind) + ", " +
1439 dwarf::GDBIndexEntryLinkageString(Desc.Linkage));
1440 Asm->EmitInt8(Desc.toBits());
1443 Asm->OutStreamer.AddComment("External Name");
1444 Asm->OutStreamer.EmitBytes(StringRef(Name, GI.getKeyLength() + 1));
1447 Asm->OutStreamer.AddComment("End Mark");
1449 Asm->OutStreamer.EmitLabel(EndLabel);
1453 void DwarfDebug::emitDebugPubTypes(bool GnuStyle) {
1454 const MCSection *PSec =
1455 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubTypesSection()
1456 : Asm->getObjFileLowering().getDwarfPubTypesSection();
1458 emitDebugPubSection(GnuStyle, PSec, "Types",
1459 &DwarfCompileUnit::getGlobalTypes);
1462 // Emit visible names into a debug str section.
1463 void DwarfDebug::emitDebugStr() {
1464 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1465 Holder.emitStrings(Asm->getObjFileLowering().getDwarfStrSection());
1469 void DwarfDebug::emitDebugLocEntry(ByteStreamer &Streamer,
1470 const DebugLocEntry &Entry) {
1471 auto Comment = Entry.getComments().begin();
1472 auto End = Entry.getComments().end();
1473 for (uint8_t Byte : Entry.getDWARFBytes())
1474 Streamer.EmitInt8(Byte, Comment != End ? *(Comment++) : "");
1477 static void emitDebugLocValue(const AsmPrinter &AP, const MDBasicType *BT,
1478 ByteStreamer &Streamer,
1479 const DebugLocEntry::Value &Value,
1480 unsigned PieceOffsetInBits) {
1481 DebugLocDwarfExpression DwarfExpr(*AP.MF->getSubtarget().getRegisterInfo(),
1482 AP.getDwarfDebug()->getDwarfVersion(),
1485 if (Value.isInt()) {
1486 if (BT && (BT->getEncoding() == dwarf::DW_ATE_signed ||
1487 BT->getEncoding() == dwarf::DW_ATE_signed_char))
1488 DwarfExpr.AddSignedConstant(Value.getInt());
1490 DwarfExpr.AddUnsignedConstant(Value.getInt());
1491 } else if (Value.isLocation()) {
1492 MachineLocation Loc = Value.getLoc();
1493 DIExpression Expr = Value.getExpression();
1494 if (!Expr || !Expr->getNumElements())
1496 AP.EmitDwarfRegOp(Streamer, Loc);
1498 // Complex address entry.
1499 if (Loc.getOffset()) {
1500 DwarfExpr.AddMachineRegIndirect(Loc.getReg(), Loc.getOffset());
1501 DwarfExpr.AddExpression(Expr->expr_op_begin(), Expr->expr_op_end(),
1504 DwarfExpr.AddMachineRegExpression(Expr, Loc.getReg(),
1508 // else ... ignore constant fp. There is not any good way to
1509 // to represent them here in dwarf.
1513 void DebugLocEntry::finalize(const AsmPrinter &AP, const MDBasicType *BT) {
1514 BufferByteStreamer Streamer(DWARFBytes, Comments);
1515 const DebugLocEntry::Value Value = Values[0];
1516 if (Value.isBitPiece()) {
1517 // Emit all pieces that belong to the same variable and range.
1518 assert(std::all_of(Values.begin(), Values.end(), [](DebugLocEntry::Value P) {
1519 return P.isBitPiece();
1520 }) && "all values are expected to be pieces");
1521 assert(std::is_sorted(Values.begin(), Values.end()) &&
1522 "pieces are expected to be sorted");
1524 unsigned Offset = 0;
1525 for (auto Piece : Values) {
1526 DIExpression Expr = Piece.getExpression();
1527 unsigned PieceOffset = Expr->getBitPieceOffset();
1528 unsigned PieceSize = Expr->getBitPieceSize();
1529 assert(Offset <= PieceOffset && "overlapping or duplicate pieces");
1530 if (Offset < PieceOffset) {
1531 // The DWARF spec seriously mandates pieces with no locations for gaps.
1532 DebugLocDwarfExpression Expr(*AP.MF->getSubtarget().getRegisterInfo(),
1533 AP.getDwarfDebug()->getDwarfVersion(),
1535 Expr.AddOpPiece(PieceOffset-Offset, 0);
1536 Offset += PieceOffset-Offset;
1538 Offset += PieceSize;
1540 emitDebugLocValue(AP, BT, Streamer, Piece, PieceOffset);
1543 assert(Values.size() == 1 && "only pieces may have >1 value");
1544 emitDebugLocValue(AP, BT, Streamer, Value, 0);
1549 void DwarfDebug::emitDebugLocEntryLocation(const DebugLocEntry &Entry) {
1550 Asm->OutStreamer.AddComment("Loc expr size");
1551 MCSymbol *begin = Asm->OutStreamer.getContext().CreateTempSymbol();
1552 MCSymbol *end = Asm->OutStreamer.getContext().CreateTempSymbol();
1553 Asm->EmitLabelDifference(end, begin, 2);
1554 Asm->OutStreamer.EmitLabel(begin);
1556 APByteStreamer Streamer(*Asm);
1557 emitDebugLocEntry(Streamer, Entry);
1559 Asm->OutStreamer.EmitLabel(end);
1562 // Emit locations into the debug loc section.
1563 void DwarfDebug::emitDebugLoc() {
1564 // Start the dwarf loc section.
1565 Asm->OutStreamer.SwitchSection(
1566 Asm->getObjFileLowering().getDwarfLocSection());
1567 unsigned char Size = Asm->getDataLayout().getPointerSize();
1568 for (const auto &DebugLoc : DotDebugLocEntries) {
1569 Asm->OutStreamer.EmitLabel(DebugLoc.Label);
1570 const DwarfCompileUnit *CU = DebugLoc.CU;
1571 for (const auto &Entry : DebugLoc.List) {
1572 // Set up the range. This range is relative to the entry point of the
1573 // compile unit. This is a hard coded 0 for low_pc when we're emitting
1574 // ranges, or the DW_AT_low_pc on the compile unit otherwise.
1575 if (auto *Base = CU->getBaseAddress()) {
1576 Asm->EmitLabelDifference(Entry.getBeginSym(), Base, Size);
1577 Asm->EmitLabelDifference(Entry.getEndSym(), Base, Size);
1579 Asm->OutStreamer.EmitSymbolValue(Entry.getBeginSym(), Size);
1580 Asm->OutStreamer.EmitSymbolValue(Entry.getEndSym(), Size);
1583 emitDebugLocEntryLocation(Entry);
1585 Asm->OutStreamer.EmitIntValue(0, Size);
1586 Asm->OutStreamer.EmitIntValue(0, Size);
1590 void DwarfDebug::emitDebugLocDWO() {
1591 Asm->OutStreamer.SwitchSection(
1592 Asm->getObjFileLowering().getDwarfLocDWOSection());
1593 for (const auto &DebugLoc : DotDebugLocEntries) {
1594 Asm->OutStreamer.EmitLabel(DebugLoc.Label);
1595 for (const auto &Entry : DebugLoc.List) {
1596 // Just always use start_length for now - at least that's one address
1597 // rather than two. We could get fancier and try to, say, reuse an
1598 // address we know we've emitted elsewhere (the start of the function?
1599 // The start of the CU or CU subrange that encloses this range?)
1600 Asm->EmitInt8(dwarf::DW_LLE_start_length_entry);
1601 unsigned idx = AddrPool.getIndex(Entry.getBeginSym());
1602 Asm->EmitULEB128(idx);
1603 Asm->EmitLabelDifference(Entry.getEndSym(), Entry.getBeginSym(), 4);
1605 emitDebugLocEntryLocation(Entry);
1607 Asm->EmitInt8(dwarf::DW_LLE_end_of_list_entry);
1612 const MCSymbol *Start, *End;
1615 // Emit a debug aranges section, containing a CU lookup for any
1616 // address we can tie back to a CU.
1617 void DwarfDebug::emitDebugARanges() {
1618 // Provides a unique id per text section.
1619 MapVector<const MCSection *, SmallVector<SymbolCU, 8>> SectionMap;
1621 // Filter labels by section.
1622 for (const SymbolCU &SCU : ArangeLabels) {
1623 if (SCU.Sym->isInSection()) {
1624 // Make a note of this symbol and it's section.
1625 const MCSection *Section = &SCU.Sym->getSection();
1626 if (!Section->getKind().isMetadata())
1627 SectionMap[Section].push_back(SCU);
1629 // Some symbols (e.g. common/bss on mach-o) can have no section but still
1630 // appear in the output. This sucks as we rely on sections to build
1631 // arange spans. We can do it without, but it's icky.
1632 SectionMap[nullptr].push_back(SCU);
1636 // Add terminating symbols for each section.
1637 for (const auto &I : SectionMap) {
1638 const MCSection *Section = I.first;
1639 MCSymbol *Sym = nullptr;
1642 Sym = Asm->OutStreamer.endSection(Section);
1644 // Insert a final terminator.
1645 SectionMap[Section].push_back(SymbolCU(nullptr, Sym));
1648 DenseMap<DwarfCompileUnit *, std::vector<ArangeSpan>> Spans;
1650 for (auto &I : SectionMap) {
1651 const MCSection *Section = I.first;
1652 SmallVector<SymbolCU, 8> &List = I.second;
1653 if (List.size() < 2)
1656 // If we have no section (e.g. common), just write out
1657 // individual spans for each symbol.
1659 for (const SymbolCU &Cur : List) {
1661 Span.Start = Cur.Sym;
1664 Spans[Cur.CU].push_back(Span);
1669 // Sort the symbols by offset within the section.
1670 std::sort(List.begin(), List.end(),
1671 [&](const SymbolCU &A, const SymbolCU &B) {
1672 unsigned IA = A.Sym ? Asm->OutStreamer.GetSymbolOrder(A.Sym) : 0;
1673 unsigned IB = B.Sym ? Asm->OutStreamer.GetSymbolOrder(B.Sym) : 0;
1675 // Symbols with no order assigned should be placed at the end.
1676 // (e.g. section end labels)
1684 // Build spans between each label.
1685 const MCSymbol *StartSym = List[0].Sym;
1686 for (size_t n = 1, e = List.size(); n < e; n++) {
1687 const SymbolCU &Prev = List[n - 1];
1688 const SymbolCU &Cur = List[n];
1690 // Try and build the longest span we can within the same CU.
1691 if (Cur.CU != Prev.CU) {
1693 Span.Start = StartSym;
1695 Spans[Prev.CU].push_back(Span);
1701 // Start the dwarf aranges section.
1702 Asm->OutStreamer.SwitchSection(
1703 Asm->getObjFileLowering().getDwarfARangesSection());
1705 unsigned PtrSize = Asm->getDataLayout().getPointerSize();
1707 // Build a list of CUs used.
1708 std::vector<DwarfCompileUnit *> CUs;
1709 for (const auto &it : Spans) {
1710 DwarfCompileUnit *CU = it.first;
1714 // Sort the CU list (again, to ensure consistent output order).
1715 std::sort(CUs.begin(), CUs.end(), [](const DwarfUnit *A, const DwarfUnit *B) {
1716 return A->getUniqueID() < B->getUniqueID();
1719 // Emit an arange table for each CU we used.
1720 for (DwarfCompileUnit *CU : CUs) {
1721 std::vector<ArangeSpan> &List = Spans[CU];
1723 // Describe the skeleton CU's offset and length, not the dwo file's.
1724 if (auto *Skel = CU->getSkeleton())
1727 // Emit size of content not including length itself.
1728 unsigned ContentSize =
1729 sizeof(int16_t) + // DWARF ARange version number
1730 sizeof(int32_t) + // Offset of CU in the .debug_info section
1731 sizeof(int8_t) + // Pointer Size (in bytes)
1732 sizeof(int8_t); // Segment Size (in bytes)
1734 unsigned TupleSize = PtrSize * 2;
1736 // 7.20 in the Dwarf specs requires the table to be aligned to a tuple.
1738 OffsetToAlignment(sizeof(int32_t) + ContentSize, TupleSize);
1740 ContentSize += Padding;
1741 ContentSize += (List.size() + 1) * TupleSize;
1743 // For each compile unit, write the list of spans it covers.
1744 Asm->OutStreamer.AddComment("Length of ARange Set");
1745 Asm->EmitInt32(ContentSize);
1746 Asm->OutStreamer.AddComment("DWARF Arange version number");
1747 Asm->EmitInt16(dwarf::DW_ARANGES_VERSION);
1748 Asm->OutStreamer.AddComment("Offset Into Debug Info Section");
1749 Asm->emitSectionOffset(CU->getLabelBegin());
1750 Asm->OutStreamer.AddComment("Address Size (in bytes)");
1751 Asm->EmitInt8(PtrSize);
1752 Asm->OutStreamer.AddComment("Segment Size (in bytes)");
1755 Asm->OutStreamer.EmitFill(Padding, 0xff);
1757 for (const ArangeSpan &Span : List) {
1758 Asm->EmitLabelReference(Span.Start, PtrSize);
1760 // Calculate the size as being from the span start to it's end.
1762 Asm->EmitLabelDifference(Span.End, Span.Start, PtrSize);
1764 // For symbols without an end marker (e.g. common), we
1765 // write a single arange entry containing just that one symbol.
1766 uint64_t Size = SymSize[Span.Start];
1770 Asm->OutStreamer.EmitIntValue(Size, PtrSize);
1774 Asm->OutStreamer.AddComment("ARange terminator");
1775 Asm->OutStreamer.EmitIntValue(0, PtrSize);
1776 Asm->OutStreamer.EmitIntValue(0, PtrSize);
1780 // Emit visible names into a debug ranges section.
1781 void DwarfDebug::emitDebugRanges() {
1782 // Start the dwarf ranges section.
1783 Asm->OutStreamer.SwitchSection(
1784 Asm->getObjFileLowering().getDwarfRangesSection());
1786 // Size for our labels.
1787 unsigned char Size = Asm->getDataLayout().getPointerSize();
1789 // Grab the specific ranges for the compile units in the module.
1790 for (const auto &I : CUMap) {
1791 DwarfCompileUnit *TheCU = I.second;
1793 if (auto *Skel = TheCU->getSkeleton())
1796 // Iterate over the misc ranges for the compile units in the module.
1797 for (const RangeSpanList &List : TheCU->getRangeLists()) {
1798 // Emit our symbol so we can find the beginning of the range.
1799 Asm->OutStreamer.EmitLabel(List.getSym());
1801 for (const RangeSpan &Range : List.getRanges()) {
1802 const MCSymbol *Begin = Range.getStart();
1803 const MCSymbol *End = Range.getEnd();
1804 assert(Begin && "Range without a begin symbol?");
1805 assert(End && "Range without an end symbol?");
1806 if (auto *Base = TheCU->getBaseAddress()) {
1807 Asm->EmitLabelDifference(Begin, Base, Size);
1808 Asm->EmitLabelDifference(End, Base, Size);
1810 Asm->OutStreamer.EmitSymbolValue(Begin, Size);
1811 Asm->OutStreamer.EmitSymbolValue(End, Size);
1815 // And terminate the list with two 0 values.
1816 Asm->OutStreamer.EmitIntValue(0, Size);
1817 Asm->OutStreamer.EmitIntValue(0, Size);
1822 // DWARF5 Experimental Separate Dwarf emitters.
1824 void DwarfDebug::initSkeletonUnit(const DwarfUnit &U, DIE &Die,
1825 std::unique_ptr<DwarfUnit> NewU) {
1826 NewU->addString(Die, dwarf::DW_AT_GNU_dwo_name,
1827 U.getCUNode()->getSplitDebugFilename());
1829 if (!CompilationDir.empty())
1830 NewU->addString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
1832 addGnuPubAttributes(*NewU, Die);
1834 SkeletonHolder.addUnit(std::move(NewU));
1837 // This DIE has the following attributes: DW_AT_comp_dir, DW_AT_stmt_list,
1838 // DW_AT_low_pc, DW_AT_high_pc, DW_AT_ranges, DW_AT_dwo_name, DW_AT_dwo_id,
1839 // DW_AT_addr_base, DW_AT_ranges_base.
1840 DwarfCompileUnit &DwarfDebug::constructSkeletonCU(const DwarfCompileUnit &CU) {
1842 auto OwnedUnit = make_unique<DwarfCompileUnit>(
1843 CU.getUniqueID(), CU.getCUNode(), Asm, this, &SkeletonHolder);
1844 DwarfCompileUnit &NewCU = *OwnedUnit;
1845 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoSection());
1847 NewCU.initStmtList();
1849 initSkeletonUnit(CU, NewCU.getUnitDie(), std::move(OwnedUnit));
1854 // Emit the .debug_info.dwo section for separated dwarf. This contains the
1855 // compile units that would normally be in debug_info.
1856 void DwarfDebug::emitDebugInfoDWO() {
1857 assert(useSplitDwarf() && "No split dwarf debug info?");
1858 // Don't emit relocations into the dwo file.
1859 InfoHolder.emitUnits(/* UseOffsets */ true);
1862 // Emit the .debug_abbrev.dwo section for separated dwarf. This contains the
1863 // abbreviations for the .debug_info.dwo section.
1864 void DwarfDebug::emitDebugAbbrevDWO() {
1865 assert(useSplitDwarf() && "No split dwarf?");
1866 InfoHolder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevDWOSection());
1869 void DwarfDebug::emitDebugLineDWO() {
1870 assert(useSplitDwarf() && "No split dwarf?");
1871 Asm->OutStreamer.SwitchSection(
1872 Asm->getObjFileLowering().getDwarfLineDWOSection());
1873 SplitTypeUnitFileTable.Emit(Asm->OutStreamer);
1876 // Emit the .debug_str.dwo section for separated dwarf. This contains the
1877 // string section and is identical in format to traditional .debug_str
1879 void DwarfDebug::emitDebugStrDWO() {
1880 assert(useSplitDwarf() && "No split dwarf?");
1881 const MCSection *OffSec =
1882 Asm->getObjFileLowering().getDwarfStrOffDWOSection();
1883 InfoHolder.emitStrings(Asm->getObjFileLowering().getDwarfStrDWOSection(),
1887 MCDwarfDwoLineTable *DwarfDebug::getDwoLineTable(const DwarfCompileUnit &CU) {
1888 if (!useSplitDwarf())
1891 SplitTypeUnitFileTable.setCompilationDir(CU.getCUNode()->getDirectory());
1892 return &SplitTypeUnitFileTable;
1895 static uint64_t makeTypeSignature(StringRef Identifier) {
1897 Hash.update(Identifier);
1898 // ... take the least significant 8 bytes and return those. Our MD5
1899 // implementation always returns its results in little endian, swap bytes
1901 MD5::MD5Result Result;
1903 return support::endian::read64le(Result + 8);
1906 void DwarfDebug::addDwarfTypeUnitType(DwarfCompileUnit &CU,
1907 StringRef Identifier, DIE &RefDie,
1908 DICompositeType CTy) {
1909 // Fast path if we're building some type units and one has already used the
1910 // address pool we know we're going to throw away all this work anyway, so
1911 // don't bother building dependent types.
1912 if (!TypeUnitsUnderConstruction.empty() && AddrPool.hasBeenUsed())
1915 const DwarfTypeUnit *&TU = DwarfTypeUnits[CTy];
1917 CU.addDIETypeSignature(RefDie, *TU);
1921 bool TopLevelType = TypeUnitsUnderConstruction.empty();
1922 AddrPool.resetUsedFlag();
1924 auto OwnedUnit = make_unique<DwarfTypeUnit>(
1925 InfoHolder.getUnits().size() + TypeUnitsUnderConstruction.size(), CU, Asm,
1926 this, &InfoHolder, getDwoLineTable(CU));
1927 DwarfTypeUnit &NewTU = *OwnedUnit;
1928 DIE &UnitDie = NewTU.getUnitDie();
1930 TypeUnitsUnderConstruction.push_back(
1931 std::make_pair(std::move(OwnedUnit), CTy));
1933 NewTU.addUInt(UnitDie, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
1936 uint64_t Signature = makeTypeSignature(Identifier);
1937 NewTU.setTypeSignature(Signature);
1939 if (useSplitDwarf())
1940 NewTU.initSection(Asm->getObjFileLowering().getDwarfTypesDWOSection());
1942 CU.applyStmtList(UnitDie);
1944 Asm->getObjFileLowering().getDwarfTypesSection(Signature));
1947 NewTU.setType(NewTU.createTypeDIE(CTy));
1950 auto TypeUnitsToAdd = std::move(TypeUnitsUnderConstruction);
1951 TypeUnitsUnderConstruction.clear();
1953 // Types referencing entries in the address table cannot be placed in type
1955 if (AddrPool.hasBeenUsed()) {
1957 // Remove all the types built while building this type.
1958 // This is pessimistic as some of these types might not be dependent on
1959 // the type that used an address.
1960 for (const auto &TU : TypeUnitsToAdd)
1961 DwarfTypeUnits.erase(TU.second);
1963 // Construct this type in the CU directly.
1964 // This is inefficient because all the dependent types will be rebuilt
1965 // from scratch, including building them in type units, discovering that
1966 // they depend on addresses, throwing them out and rebuilding them.
1967 CU.constructTypeDIE(RefDie, CTy);
1971 // If the type wasn't dependent on fission addresses, finish adding the type
1972 // and all its dependent types.
1973 for (auto &TU : TypeUnitsToAdd)
1974 InfoHolder.addUnit(std::move(TU.first));
1976 CU.addDIETypeSignature(RefDie, NewTU);
1979 // Accelerator table mutators - add each name along with its companion
1980 // DIE to the proper table while ensuring that the name that we're going
1981 // to reference is in the string table. We do this since the names we
1982 // add may not only be identical to the names in the DIE.
1983 void DwarfDebug::addAccelName(StringRef Name, const DIE &Die) {
1984 if (!useDwarfAccelTables())
1986 AccelNames.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
1990 void DwarfDebug::addAccelObjC(StringRef Name, const DIE &Die) {
1991 if (!useDwarfAccelTables())
1993 AccelObjC.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
1997 void DwarfDebug::addAccelNamespace(StringRef Name, const DIE &Die) {
1998 if (!useDwarfAccelTables())
2000 AccelNamespace.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2004 void DwarfDebug::addAccelType(StringRef Name, const DIE &Die, char Flags) {
2005 if (!useDwarfAccelTables())
2007 AccelTypes.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),