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/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/MCDwarf.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/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"
58 #define DEBUG_TYPE "dwarfdebug"
61 DisableDebugInfoPrinting("disable-debug-info-print", cl::Hidden,
62 cl::desc("Disable debug info printing"));
65 GenerateGnuPubSections("generate-gnu-dwarf-pub-sections", cl::Hidden,
66 cl::desc("Generate GNU-style pubnames and pubtypes"),
69 static cl::opt<bool> GenerateARangeSection("generate-arange-section",
71 cl::desc("Generate dwarf aranges"),
75 enum DefaultOnOff { Default, Enable, Disable };
78 static cl::opt<DefaultOnOff> UnknownLocations(
79 "use-unknown-locations", cl::Hidden,
80 cl::desc("Make an absence of debug location information explicit."),
81 cl::values(clEnumVal(Default, "At top of block or after label"),
82 clEnumVal(Enable, "In all cases"), clEnumVal(Disable, "Never")),
85 static cl::opt<DefaultOnOff>
86 DwarfAccelTables("dwarf-accel-tables", cl::Hidden,
87 cl::desc("Output prototype dwarf accelerator tables."),
88 cl::values(clEnumVal(Default, "Default for platform"),
89 clEnumVal(Enable, "Enabled"),
90 clEnumVal(Disable, "Disabled")),
93 static cl::opt<DefaultOnOff>
94 DwarfPubSections("generate-dwarf-pub-sections", cl::Hidden,
95 cl::desc("Generate DWARF pubnames and pubtypes sections"),
96 cl::values(clEnumVal(Default, "Default for platform"),
97 clEnumVal(Enable, "Enabled"),
98 clEnumVal(Disable, "Disabled")),
101 enum LinkageNameOption {
106 static cl::opt<LinkageNameOption>
107 DwarfLinkageNames("dwarf-linkage-names", cl::Hidden,
108 cl::desc("Which DWARF linkage-name attributes to emit."),
109 cl::values(clEnumValN(DefaultLinkageNames, "Default",
110 "Default for platform"),
111 clEnumValN(AllLinkageNames, "All", "All"),
112 clEnumValN(AbstractLinkageNames, "Abstract",
113 "Abstract subprograms")),
114 cl::init(DefaultLinkageNames));
116 static const char *const DWARFGroupName = "dwarf";
117 static const char *const DWARFGroupDescription = "DWARF Emission";
118 static const char *const DbgTimerName = "writer";
119 static const char *const DbgTimerDescription = "DWARF Debug Writer";
121 void DebugLocDwarfExpression::emitOp(uint8_t Op, const char *Comment) {
123 Op, Comment ? Twine(Comment) + " " + dwarf::OperationEncodingString(Op)
124 : dwarf::OperationEncodingString(Op));
127 void DebugLocDwarfExpression::emitSigned(int64_t Value) {
128 BS.EmitSLEB128(Value, Twine(Value));
131 void DebugLocDwarfExpression::emitUnsigned(uint64_t Value) {
132 BS.EmitULEB128(Value, Twine(Value));
135 bool DebugLocDwarfExpression::isFrameRegister(const TargetRegisterInfo &TRI,
136 unsigned MachineReg) {
137 // This information is not available while emitting .debug_loc entries.
141 //===----------------------------------------------------------------------===//
143 bool DbgVariable::isBlockByrefVariable() const {
144 assert(Var && "Invalid complex DbgVariable!");
145 return Var->getType().resolve()->isBlockByrefStruct();
148 const DIType *DbgVariable::getType() const {
149 DIType *Ty = Var->getType().resolve();
150 // FIXME: isBlockByrefVariable should be reformulated in terms of complex
151 // addresses instead.
152 if (Ty->isBlockByrefStruct()) {
153 /* Byref variables, in Blocks, are declared by the programmer as
154 "SomeType VarName;", but the compiler creates a
155 __Block_byref_x_VarName struct, and gives the variable VarName
156 either the struct, or a pointer to the struct, as its type. This
157 is necessary for various behind-the-scenes things the compiler
158 needs to do with by-reference variables in blocks.
160 However, as far as the original *programmer* is concerned, the
161 variable should still have type 'SomeType', as originally declared.
163 The following function dives into the __Block_byref_x_VarName
164 struct to find the original type of the variable. This will be
165 passed back to the code generating the type for the Debug
166 Information Entry for the variable 'VarName'. 'VarName' will then
167 have the original type 'SomeType' in its debug information.
169 The original type 'SomeType' will be the type of the field named
170 'VarName' inside the __Block_byref_x_VarName struct.
172 NOTE: In order for this to not completely fail on the debugger
173 side, the Debug Information Entry for the variable VarName needs to
174 have a DW_AT_location that tells the debugger how to unwind through
175 the pointers and __Block_byref_x_VarName struct to find the actual
176 value of the variable. The function addBlockByrefType does this. */
177 DIType *subType = Ty;
178 uint16_t tag = Ty->getTag();
180 if (tag == dwarf::DW_TAG_pointer_type)
181 subType = resolve(cast<DIDerivedType>(Ty)->getBaseType());
183 auto Elements = cast<DICompositeType>(subType)->getElements();
184 for (unsigned i = 0, N = Elements.size(); i < N; ++i) {
185 auto *DT = cast<DIDerivedType>(Elements[i]);
186 if (getName() == DT->getName())
187 return resolve(DT->getBaseType());
193 ArrayRef<DbgVariable::FrameIndexExpr> DbgVariable::getFrameIndexExprs() const {
194 if (FrameIndexExprs.size() == 1)
195 return FrameIndexExprs;
197 assert(all_of(FrameIndexExprs,
198 [](const FrameIndexExpr &A) { return A.Expr->isFragment(); }) &&
199 "multiple FI expressions without DW_OP_LLVM_fragment");
200 std::sort(FrameIndexExprs.begin(), FrameIndexExprs.end(),
201 [](const FrameIndexExpr &A, const FrameIndexExpr &B) -> bool {
202 return A.Expr->getFragmentInfo()->OffsetInBits <
203 B.Expr->getFragmentInfo()->OffsetInBits;
205 return FrameIndexExprs;
208 static const DwarfAccelTable::Atom TypeAtoms[] = {
209 DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset, dwarf::DW_FORM_data4),
210 DwarfAccelTable::Atom(dwarf::DW_ATOM_die_tag, dwarf::DW_FORM_data2),
211 DwarfAccelTable::Atom(dwarf::DW_ATOM_type_flags, dwarf::DW_FORM_data1)};
213 DwarfDebug::DwarfDebug(AsmPrinter *A, Module *M)
214 : DebugHandlerBase(A), DebugLocs(A->OutStreamer->isVerboseAsm()),
215 InfoHolder(A, "info_string", DIEValueAllocator),
216 SkeletonHolder(A, "skel_string", DIEValueAllocator),
217 IsDarwin(A->TM.getTargetTriple().isOSDarwin()),
218 AccelNames(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
219 dwarf::DW_FORM_data4)),
220 AccelObjC(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
221 dwarf::DW_FORM_data4)),
222 AccelNamespace(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
223 dwarf::DW_FORM_data4)),
224 AccelTypes(TypeAtoms), DebuggerTuning(DebuggerKind::Default) {
227 const Triple &TT = Asm->TM.getTargetTriple();
229 // Make sure we know our "debugger tuning." The target option takes
230 // precedence; fall back to triple-based defaults.
231 if (Asm->TM.Options.DebuggerTuning != DebuggerKind::Default)
232 DebuggerTuning = Asm->TM.Options.DebuggerTuning;
234 DebuggerTuning = DebuggerKind::LLDB;
235 else if (TT.isPS4CPU())
236 DebuggerTuning = DebuggerKind::SCE;
238 DebuggerTuning = DebuggerKind::GDB;
240 // Turn on accelerator tables for LLDB by default.
241 if (DwarfAccelTables == Default)
242 HasDwarfAccelTables = tuneForLLDB();
244 HasDwarfAccelTables = DwarfAccelTables == Enable;
246 HasAppleExtensionAttributes = tuneForLLDB();
248 // Handle split DWARF.
249 HasSplitDwarf = !Asm->TM.Options.MCOptions.SplitDwarfFile.empty();
251 // Pubnames/pubtypes on by default for GDB.
252 if (DwarfPubSections == Default)
253 HasDwarfPubSections = tuneForGDB();
255 HasDwarfPubSections = DwarfPubSections == Enable;
257 // SCE defaults to linkage names only for abstract subprograms.
258 if (DwarfLinkageNames == DefaultLinkageNames)
259 UseAllLinkageNames = !tuneForSCE();
261 UseAllLinkageNames = DwarfLinkageNames == AllLinkageNames;
263 unsigned DwarfVersionNumber = Asm->TM.Options.MCOptions.DwarfVersion;
264 unsigned DwarfVersion = DwarfVersionNumber ? DwarfVersionNumber
265 : MMI->getModule()->getDwarfVersion();
266 // Use dwarf 4 by default if nothing is requested.
267 DwarfVersion = DwarfVersion ? DwarfVersion : dwarf::DWARF_VERSION;
269 // Work around a GDB bug. GDB doesn't support the standard opcode;
270 // SCE doesn't support GNU's; LLDB prefers the standard opcode, which
271 // is defined as of DWARF 3.
272 // See GDB bug 11616 - DW_OP_form_tls_address is unimplemented
273 // https://sourceware.org/bugzilla/show_bug.cgi?id=11616
274 UseGNUTLSOpcode = tuneForGDB() || DwarfVersion < 3;
276 // GDB does not fully support the DWARF 4 representation for bitfields.
277 UseDWARF2Bitfields = (DwarfVersion < 4) || tuneForGDB();
279 Asm->OutStreamer->getContext().setDwarfVersion(DwarfVersion);
282 // Define out of line so we don't have to include DwarfUnit.h in DwarfDebug.h.
283 DwarfDebug::~DwarfDebug() { }
285 static bool isObjCClass(StringRef Name) {
286 return Name.startswith("+") || Name.startswith("-");
289 static bool hasObjCCategory(StringRef Name) {
290 if (!isObjCClass(Name))
293 return Name.find(") ") != StringRef::npos;
296 static void getObjCClassCategory(StringRef In, StringRef &Class,
297 StringRef &Category) {
298 if (!hasObjCCategory(In)) {
299 Class = In.slice(In.find('[') + 1, In.find(' '));
304 Class = In.slice(In.find('[') + 1, In.find('('));
305 Category = In.slice(In.find('[') + 1, In.find(' '));
308 static StringRef getObjCMethodName(StringRef In) {
309 return In.slice(In.find(' ') + 1, In.find(']'));
312 // Add the various names to the Dwarf accelerator table names.
313 // TODO: Determine whether or not we should add names for programs
314 // that do not have a DW_AT_name or DW_AT_linkage_name field - this
315 // is only slightly different than the lookup of non-standard ObjC names.
316 void DwarfDebug::addSubprogramNames(const DISubprogram *SP, DIE &Die) {
317 if (!SP->isDefinition())
319 addAccelName(SP->getName(), Die);
321 // If the linkage name is different than the name, go ahead and output
322 // that as well into the name table.
323 if (SP->getLinkageName() != "" && SP->getName() != SP->getLinkageName())
324 addAccelName(SP->getLinkageName(), Die);
326 // If this is an Objective-C selector name add it to the ObjC accelerator
328 if (isObjCClass(SP->getName())) {
329 StringRef Class, Category;
330 getObjCClassCategory(SP->getName(), Class, Category);
331 addAccelObjC(Class, Die);
333 addAccelObjC(Category, Die);
334 // Also add the base method name to the name table.
335 addAccelName(getObjCMethodName(SP->getName()), Die);
339 /// Check whether we should create a DIE for the given Scope, return true
340 /// if we don't create a DIE (the corresponding DIE is null).
341 bool DwarfDebug::isLexicalScopeDIENull(LexicalScope *Scope) {
342 if (Scope->isAbstractScope())
345 // We don't create a DIE if there is no Range.
346 const SmallVectorImpl<InsnRange> &Ranges = Scope->getRanges();
350 if (Ranges.size() > 1)
353 // We don't create a DIE if we have a single Range and the end label
355 return !getLabelAfterInsn(Ranges.front().second);
358 template <typename Func> static void forBothCUs(DwarfCompileUnit &CU, Func F) {
360 if (auto *SkelCU = CU.getSkeleton())
361 if (CU.getCUNode()->getSplitDebugInlining())
365 void DwarfDebug::constructAbstractSubprogramScopeDIE(LexicalScope *Scope) {
366 assert(Scope && Scope->getScopeNode());
367 assert(Scope->isAbstractScope());
368 assert(!Scope->getInlinedAt());
370 auto *SP = cast<DISubprogram>(Scope->getScopeNode());
372 ProcessedSPNodes.insert(SP);
374 // Find the subprogram's DwarfCompileUnit in the SPMap in case the subprogram
375 // was inlined from another compile unit.
376 auto &CU = *CUMap.lookup(SP->getUnit());
377 forBothCUs(CU, [&](DwarfCompileUnit &CU) {
378 CU.constructAbstractSubprogramScopeDIE(Scope);
382 void DwarfDebug::addGnuPubAttributes(DwarfUnit &U, DIE &D) const {
383 if (!GenerateGnuPubSections)
386 U.addFlag(D, dwarf::DW_AT_GNU_pubnames);
389 // Create new DwarfCompileUnit for the given metadata node with tag
390 // DW_TAG_compile_unit.
392 DwarfDebug::constructDwarfCompileUnit(const DICompileUnit *DIUnit) {
393 StringRef FN = DIUnit->getFilename();
394 CompilationDir = DIUnit->getDirectory();
396 auto OwnedUnit = make_unique<DwarfCompileUnit>(
397 InfoHolder.getUnits().size(), DIUnit, Asm, this, &InfoHolder);
398 DwarfCompileUnit &NewCU = *OwnedUnit;
399 DIE &Die = NewCU.getUnitDie();
400 InfoHolder.addUnit(std::move(OwnedUnit));
401 if (useSplitDwarf()) {
402 NewCU.setSkeleton(constructSkeletonCU(NewCU));
403 NewCU.addString(Die, dwarf::DW_AT_GNU_dwo_name,
404 Asm->TM.Options.MCOptions.SplitDwarfFile);
407 // LTO with assembly output shares a single line table amongst multiple CUs.
408 // To avoid the compilation directory being ambiguous, let the line table
409 // explicitly describe the directory of all files, never relying on the
410 // compilation directory.
411 if (!Asm->OutStreamer->hasRawTextSupport() || SingleCU)
412 Asm->OutStreamer->getContext().setMCLineTableCompilationDir(
413 NewCU.getUniqueID(), CompilationDir);
415 StringRef Producer = DIUnit->getProducer();
416 StringRef Flags = DIUnit->getFlags();
417 if (!Flags.empty()) {
418 std::string ProducerWithFlags = Producer.str() + " " + Flags.str();
419 NewCU.addString(Die, dwarf::DW_AT_producer, ProducerWithFlags);
421 NewCU.addString(Die, dwarf::DW_AT_producer, Producer);
423 NewCU.addUInt(Die, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
424 DIUnit->getSourceLanguage());
425 NewCU.addString(Die, dwarf::DW_AT_name, FN);
427 if (!useSplitDwarf()) {
428 NewCU.initStmtList();
430 // If we're using split dwarf the compilation dir is going to be in the
431 // skeleton CU and so we don't need to duplicate it here.
432 if (!CompilationDir.empty())
433 NewCU.addString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
435 addGnuPubAttributes(NewCU, Die);
438 if (useAppleExtensionAttributes()) {
439 if (DIUnit->isOptimized())
440 NewCU.addFlag(Die, dwarf::DW_AT_APPLE_optimized);
442 StringRef Flags = DIUnit->getFlags();
444 NewCU.addString(Die, dwarf::DW_AT_APPLE_flags, Flags);
446 if (unsigned RVer = DIUnit->getRuntimeVersion())
447 NewCU.addUInt(Die, dwarf::DW_AT_APPLE_major_runtime_vers,
448 dwarf::DW_FORM_data1, RVer);
452 NewCU.setSection(Asm->getObjFileLowering().getDwarfInfoDWOSection());
454 NewCU.setSection(Asm->getObjFileLowering().getDwarfInfoSection());
456 if (DIUnit->getDWOId()) {
457 // This CU is either a clang module DWO or a skeleton CU.
458 NewCU.addUInt(Die, dwarf::DW_AT_GNU_dwo_id, dwarf::DW_FORM_data8,
460 if (!DIUnit->getSplitDebugFilename().empty())
461 // This is a prefabricated skeleton CU.
462 NewCU.addString(Die, dwarf::DW_AT_GNU_dwo_name,
463 DIUnit->getSplitDebugFilename());
466 CUMap.insert({DIUnit, &NewCU});
467 CUDieMap.insert({&Die, &NewCU});
471 void DwarfDebug::constructAndAddImportedEntityDIE(DwarfCompileUnit &TheCU,
472 const DIImportedEntity *N) {
473 if (DIE *D = TheCU.getOrCreateContextDIE(N->getScope()))
474 D->addChild(TheCU.constructImportedEntityDIE(N));
477 /// Sort and unique GVEs by comparing their fragment offset.
478 static SmallVectorImpl<DwarfCompileUnit::GlobalExpr> &
479 sortGlobalExprs(SmallVectorImpl<DwarfCompileUnit::GlobalExpr> &GVEs) {
480 std::sort(GVEs.begin(), GVEs.end(),
481 [](DwarfCompileUnit::GlobalExpr A, DwarfCompileUnit::GlobalExpr B) {
482 if (A.Expr != B.Expr && A.Expr && B.Expr) {
483 auto FragmentA = A.Expr->getFragmentInfo();
484 auto FragmentB = B.Expr->getFragmentInfo();
485 if (FragmentA && FragmentB)
486 return FragmentA->OffsetInBits < FragmentB->OffsetInBits;
490 GVEs.erase(std::unique(GVEs.begin(), GVEs.end(),
491 [](DwarfCompileUnit::GlobalExpr A,
492 DwarfCompileUnit::GlobalExpr B) {
493 return A.Expr == B.Expr;
499 // Emit all Dwarf sections that should come prior to the content. Create
500 // global DIEs and emit initial debug info sections. This is invoked by
501 // the target AsmPrinter.
502 void DwarfDebug::beginModule() {
503 NamedRegionTimer T(DbgTimerName, DbgTimerDescription, DWARFGroupName,
504 DWARFGroupDescription, TimePassesIsEnabled);
505 if (DisableDebugInfoPrinting)
508 const Module *M = MMI->getModule();
510 unsigned NumDebugCUs = std::distance(M->debug_compile_units_begin(),
511 M->debug_compile_units_end());
512 // Tell MMI whether we have debug info.
513 MMI->setDebugInfoAvailability(NumDebugCUs > 0);
514 SingleCU = NumDebugCUs == 1;
515 DenseMap<DIGlobalVariable *, SmallVector<DwarfCompileUnit::GlobalExpr, 1>>
517 for (const GlobalVariable &Global : M->globals()) {
518 SmallVector<DIGlobalVariableExpression *, 1> GVs;
519 Global.getDebugInfo(GVs);
520 for (auto *GVE : GVs)
521 GVMap[GVE->getVariable()].push_back({&Global, GVE->getExpression()});
524 for (DICompileUnit *CUNode : M->debug_compile_units()) {
525 DwarfCompileUnit &CU = constructDwarfCompileUnit(CUNode);
526 for (auto *IE : CUNode->getImportedEntities())
527 CU.addImportedEntity(IE);
530 for (auto *GVE : CUNode->getGlobalVariables())
531 GVMap[GVE->getVariable()].push_back({nullptr, GVE->getExpression()});
532 DenseSet<DIGlobalVariable *> Processed;
533 for (auto *GVE : CUNode->getGlobalVariables()) {
534 DIGlobalVariable *GV = GVE->getVariable();
535 if (Processed.insert(GV).second)
536 CU.getOrCreateGlobalVariableDIE(GV, sortGlobalExprs(GVMap[GV]));
539 for (auto *Ty : CUNode->getEnumTypes()) {
540 // The enum types array by design contains pointers to
541 // MDNodes rather than DIRefs. Unique them here.
542 CU.getOrCreateTypeDIE(cast<DIType>(Ty));
544 for (auto *Ty : CUNode->getRetainedTypes()) {
545 // The retained types array by design contains pointers to
546 // MDNodes rather than DIRefs. Unique them here.
547 if (DIType *RT = dyn_cast<DIType>(Ty))
548 // There is no point in force-emitting a forward declaration.
549 CU.getOrCreateTypeDIE(RT);
551 // Emit imported_modules last so that the relevant context is already
553 for (auto *IE : CUNode->getImportedEntities())
554 constructAndAddImportedEntityDIE(CU, IE);
558 void DwarfDebug::finishVariableDefinitions() {
559 for (const auto &Var : ConcreteVariables) {
560 DIE *VariableDie = Var->getDIE();
562 // FIXME: Consider the time-space tradeoff of just storing the unit pointer
563 // in the ConcreteVariables list, rather than looking it up again here.
564 // DIE::getUnit isn't simple - it walks parent pointers, etc.
565 DwarfCompileUnit *Unit = CUDieMap.lookup(VariableDie->getUnitDie());
567 DbgVariable *AbsVar = getExistingAbstractVariable(
568 InlinedVariable(Var->getVariable(), Var->getInlinedAt()));
569 if (AbsVar && AbsVar->getDIE()) {
570 Unit->addDIEEntry(*VariableDie, dwarf::DW_AT_abstract_origin,
573 Unit->applyVariableAttributes(*Var, *VariableDie);
577 void DwarfDebug::finishSubprogramDefinitions() {
578 for (const DISubprogram *SP : ProcessedSPNodes)
579 if (SP->getUnit()->getEmissionKind() != DICompileUnit::NoDebug)
580 forBothCUs(*CUMap.lookup(SP->getUnit()), [&](DwarfCompileUnit &CU) {
581 CU.finishSubprogramDefinition(SP);
585 void DwarfDebug::finalizeModuleInfo() {
586 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
588 finishSubprogramDefinitions();
590 finishVariableDefinitions();
592 // Handle anything that needs to be done on a per-unit basis after
593 // all other generation.
594 for (const auto &P : CUMap) {
595 auto &TheCU = *P.second;
596 // Emit DW_AT_containing_type attribute to connect types with their
597 // vtable holding type.
598 TheCU.constructContainingTypeDIEs();
600 // Add CU specific attributes if we need to add any.
601 // If we're splitting the dwarf out now that we've got the entire
602 // CU then add the dwo id to it.
603 auto *SkCU = TheCU.getSkeleton();
604 if (useSplitDwarf()) {
605 // Emit a unique identifier for this CU.
606 uint64_t ID = DIEHash(Asm).computeCUSignature(TheCU.getUnitDie());
607 TheCU.addUInt(TheCU.getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
608 dwarf::DW_FORM_data8, ID);
609 SkCU->addUInt(SkCU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
610 dwarf::DW_FORM_data8, ID);
612 // We don't keep track of which addresses are used in which CU so this
613 // is a bit pessimistic under LTO.
614 if (!AddrPool.isEmpty()) {
615 const MCSymbol *Sym = TLOF.getDwarfAddrSection()->getBeginSymbol();
616 SkCU->addSectionLabel(SkCU->getUnitDie(), dwarf::DW_AT_GNU_addr_base,
619 if (!SkCU->getRangeLists().empty()) {
620 const MCSymbol *Sym = TLOF.getDwarfRangesSection()->getBeginSymbol();
621 SkCU->addSectionLabel(SkCU->getUnitDie(), dwarf::DW_AT_GNU_ranges_base,
626 // If we have code split among multiple sections or non-contiguous
627 // ranges of code then emit a DW_AT_ranges attribute on the unit that will
628 // remain in the .o file, otherwise add a DW_AT_low_pc.
629 // FIXME: We should use ranges allow reordering of code ala
630 // .subsections_via_symbols in mach-o. This would mean turning on
631 // ranges for all subprogram DIEs for mach-o.
632 DwarfCompileUnit &U = SkCU ? *SkCU : TheCU;
633 if (unsigned NumRanges = TheCU.getRanges().size()) {
635 // A DW_AT_low_pc attribute may also be specified in combination with
636 // DW_AT_ranges to specify the default base address for use in
637 // location lists (see Section 2.6.2) and range lists (see Section
639 U.addUInt(U.getUnitDie(), dwarf::DW_AT_low_pc, dwarf::DW_FORM_addr, 0);
641 U.setBaseAddress(TheCU.getRanges().front().getStart());
642 U.attachRangesOrLowHighPC(U.getUnitDie(), TheCU.takeRanges());
645 auto *CUNode = cast<DICompileUnit>(P.first);
646 // If compile Unit has macros, emit "DW_AT_macro_info" attribute.
647 if (CUNode->getMacros())
648 U.addSectionLabel(U.getUnitDie(), dwarf::DW_AT_macro_info,
649 U.getMacroLabelBegin(),
650 TLOF.getDwarfMacinfoSection()->getBeginSymbol());
653 // Compute DIE offsets and sizes.
654 InfoHolder.computeSizeAndOffsets();
656 SkeletonHolder.computeSizeAndOffsets();
659 // Emit all Dwarf sections that should come after the content.
660 void DwarfDebug::endModule() {
661 assert(CurFn == nullptr);
662 assert(CurMI == nullptr);
664 // If we aren't actually generating debug info (check beginModule -
665 // conditionalized on !DisableDebugInfoPrinting and the presence of the
666 // llvm.dbg.cu metadata node)
667 if (!MMI->hasDebugInfo())
670 // Finalize the debug info for the module.
671 finalizeModuleInfo();
678 // Emit info into a debug loc section.
681 // Corresponding abbreviations into a abbrev section.
684 // Emit all the DIEs into a debug info section.
687 // Emit info into a debug aranges section.
688 if (GenerateARangeSection)
691 // Emit info into a debug ranges section.
694 // Emit info into a debug macinfo section.
697 if (useSplitDwarf()) {
700 emitDebugAbbrevDWO();
702 // Emit DWO addresses.
703 AddrPool.emit(*Asm, Asm->getObjFileLowering().getDwarfAddrSection());
706 // Emit info into the dwarf accelerator table sections.
707 if (useDwarfAccelTables()) {
710 emitAccelNamespaces();
714 // Emit the pubnames and pubtypes sections if requested.
715 if (HasDwarfPubSections) {
716 emitDebugPubNames(GenerateGnuPubSections);
717 emitDebugPubTypes(GenerateGnuPubSections);
721 AbstractVariables.clear();
724 // Find abstract variable, if any, associated with Var.
726 DwarfDebug::getExistingAbstractVariable(InlinedVariable IV,
727 const DILocalVariable *&Cleansed) {
728 // More then one inlined variable corresponds to one abstract variable.
730 auto I = AbstractVariables.find(Cleansed);
731 if (I != AbstractVariables.end())
732 return I->second.get();
736 DbgVariable *DwarfDebug::getExistingAbstractVariable(InlinedVariable IV) {
737 const DILocalVariable *Cleansed;
738 return getExistingAbstractVariable(IV, Cleansed);
741 void DwarfDebug::createAbstractVariable(const DILocalVariable *Var,
742 LexicalScope *Scope) {
743 assert(Scope && Scope->isAbstractScope());
744 auto AbsDbgVariable = make_unique<DbgVariable>(Var, /* IA */ nullptr);
745 InfoHolder.addScopeVariable(Scope, AbsDbgVariable.get());
746 AbstractVariables[Var] = std::move(AbsDbgVariable);
749 void DwarfDebug::ensureAbstractVariableIsCreated(InlinedVariable IV,
750 const MDNode *ScopeNode) {
751 const DILocalVariable *Cleansed = nullptr;
752 if (getExistingAbstractVariable(IV, Cleansed))
755 createAbstractVariable(Cleansed, LScopes.getOrCreateAbstractScope(
756 cast<DILocalScope>(ScopeNode)));
759 void DwarfDebug::ensureAbstractVariableIsCreatedIfScoped(
760 InlinedVariable IV, const MDNode *ScopeNode) {
761 const DILocalVariable *Cleansed = nullptr;
762 if (getExistingAbstractVariable(IV, Cleansed))
765 if (LexicalScope *Scope =
766 LScopes.findAbstractScope(cast_or_null<DILocalScope>(ScopeNode)))
767 createAbstractVariable(Cleansed, Scope);
770 // Collect variable information from side table maintained by MF.
771 void DwarfDebug::collectVariableInfoFromMFTable(
772 DenseSet<InlinedVariable> &Processed) {
773 for (const auto &VI : Asm->MF->getVariableDbgInfo()) {
776 assert(VI.Var->isValidLocationForIntrinsic(VI.Loc) &&
777 "Expected inlined-at fields to agree");
779 InlinedVariable Var(VI.Var, VI.Loc->getInlinedAt());
780 Processed.insert(Var);
781 LexicalScope *Scope = LScopes.findLexicalScope(VI.Loc);
783 // If variable scope is not found then skip this variable.
787 ensureAbstractVariableIsCreatedIfScoped(Var, Scope->getScopeNode());
788 auto RegVar = make_unique<DbgVariable>(Var.first, Var.second);
789 RegVar->initializeMMI(VI.Expr, VI.Slot);
790 if (InfoHolder.addScopeVariable(Scope, RegVar.get()))
791 ConcreteVariables.push_back(std::move(RegVar));
795 // Get .debug_loc entry for the instruction range starting at MI.
796 static DebugLocEntry::Value getDebugLocValue(const MachineInstr *MI) {
797 const DIExpression *Expr = MI->getDebugExpression();
799 assert(MI->getNumOperands() == 4);
800 if (MI->getOperand(0).isReg()) {
801 MachineLocation MLoc;
802 // If the second operand is an immediate, this is a
803 // register-indirect address.
804 if (!MI->getOperand(1).isImm())
805 MLoc.set(MI->getOperand(0).getReg());
807 MLoc.set(MI->getOperand(0).getReg(), MI->getOperand(1).getImm());
808 return DebugLocEntry::Value(Expr, MLoc);
810 if (MI->getOperand(0).isImm())
811 return DebugLocEntry::Value(Expr, MI->getOperand(0).getImm());
812 if (MI->getOperand(0).isFPImm())
813 return DebugLocEntry::Value(Expr, MI->getOperand(0).getFPImm());
814 if (MI->getOperand(0).isCImm())
815 return DebugLocEntry::Value(Expr, MI->getOperand(0).getCImm());
817 llvm_unreachable("Unexpected 4-operand DBG_VALUE instruction!");
820 /// \brief If this and Next are describing different fragments of the same
821 /// variable, merge them by appending Next's values to the current
823 /// Return true if the merge was successful.
824 bool DebugLocEntry::MergeValues(const DebugLocEntry &Next) {
825 if (Begin == Next.Begin) {
826 auto *FirstExpr = cast<DIExpression>(Values[0].Expression);
827 auto *FirstNextExpr = cast<DIExpression>(Next.Values[0].Expression);
828 if (!FirstExpr->isFragment() || !FirstNextExpr->isFragment())
831 // We can only merge entries if none of the fragments overlap any others.
832 // In doing so, we can take advantage of the fact that both lists are
834 for (unsigned i = 0, j = 0; i < Values.size(); ++i) {
835 for (; j < Next.Values.size(); ++j) {
836 int res = DebugHandlerBase::fragmentCmp(
837 cast<DIExpression>(Values[i].Expression),
838 cast<DIExpression>(Next.Values[j].Expression));
839 if (res == 0) // The two expressions overlap, we can't merge.
841 // Values[i] is entirely before Next.Values[j],
842 // so go back to the next entry of Values.
845 // Next.Values[j] is entirely before Values[i], so go on to the
846 // next entry of Next.Values.
850 addValues(Next.Values);
857 /// Build the location list for all DBG_VALUEs in the function that
858 /// describe the same variable. If the ranges of several independent
859 /// fragments of the same variable overlap partially, split them up and
860 /// combine the ranges. The resulting DebugLocEntries are will have
861 /// strict monotonically increasing begin addresses and will never
866 // Ranges History [var, loc, fragment ofs size]
867 // 0 | [x, (reg0, fragment 0, 32)]
868 // 1 | | [x, (reg1, fragment 32, 32)] <- IsFragmentOfPrevEntry
870 // 3 | [clobber reg0]
871 // 4 [x, (mem, fragment 0, 64)] <- overlapping with both previous fragments of
876 // [0-1] [x, (reg0, fragment 0, 32)]
877 // [1-3] [x, (reg0, fragment 0, 32), (reg1, fragment 32, 32)]
878 // [3-4] [x, (reg1, fragment 32, 32)]
879 // [4- ] [x, (mem, fragment 0, 64)]
881 DwarfDebug::buildLocationList(SmallVectorImpl<DebugLocEntry> &DebugLoc,
882 const DbgValueHistoryMap::InstrRanges &Ranges) {
883 SmallVector<DebugLocEntry::Value, 4> OpenRanges;
885 for (auto I = Ranges.begin(), E = Ranges.end(); I != E; ++I) {
886 const MachineInstr *Begin = I->first;
887 const MachineInstr *End = I->second;
888 assert(Begin->isDebugValue() && "Invalid History entry");
890 // Check if a variable is inaccessible in this range.
891 if (Begin->getNumOperands() > 1 &&
892 Begin->getOperand(0).isReg() && !Begin->getOperand(0).getReg()) {
897 // If this fragment overlaps with any open ranges, truncate them.
898 const DIExpression *DIExpr = Begin->getDebugExpression();
899 auto Last = remove_if(OpenRanges, [&](DebugLocEntry::Value R) {
900 return fragmentsOverlap(DIExpr, R.getExpression());
902 OpenRanges.erase(Last, OpenRanges.end());
904 const MCSymbol *StartLabel = getLabelBeforeInsn(Begin);
905 assert(StartLabel && "Forgot label before DBG_VALUE starting a range!");
907 const MCSymbol *EndLabel;
909 EndLabel = getLabelAfterInsn(End);
910 else if (std::next(I) == Ranges.end())
911 EndLabel = Asm->getFunctionEnd();
913 EndLabel = getLabelBeforeInsn(std::next(I)->first);
914 assert(EndLabel && "Forgot label after instruction ending a range!");
916 DEBUG(dbgs() << "DotDebugLoc: " << *Begin << "\n");
918 auto Value = getDebugLocValue(Begin);
919 DebugLocEntry Loc(StartLabel, EndLabel, Value);
920 bool couldMerge = false;
922 // If this is a fragment, it may belong to the current DebugLocEntry.
923 if (DIExpr->isFragment()) {
924 // Add this value to the list of open ranges.
925 OpenRanges.push_back(Value);
927 // Attempt to add the fragment to the last entry.
928 if (!DebugLoc.empty())
929 if (DebugLoc.back().MergeValues(Loc))
934 // Need to add a new DebugLocEntry. Add all values from still
935 // valid non-overlapping fragments.
936 if (OpenRanges.size())
937 Loc.addValues(OpenRanges);
939 DebugLoc.push_back(std::move(Loc));
942 // Attempt to coalesce the ranges of two otherwise identical
944 auto CurEntry = DebugLoc.rbegin();
946 dbgs() << CurEntry->getValues().size() << " Values:\n";
947 for (auto &Value : CurEntry->getValues())
952 auto PrevEntry = std::next(CurEntry);
953 if (PrevEntry != DebugLoc.rend() && PrevEntry->MergeRanges(*CurEntry))
958 DbgVariable *DwarfDebug::createConcreteVariable(LexicalScope &Scope,
959 InlinedVariable IV) {
960 ensureAbstractVariableIsCreatedIfScoped(IV, Scope.getScopeNode());
961 ConcreteVariables.push_back(make_unique<DbgVariable>(IV.first, IV.second));
962 InfoHolder.addScopeVariable(&Scope, ConcreteVariables.back().get());
963 return ConcreteVariables.back().get();
966 // Determine whether this DBG_VALUE is valid at the beginning of the function.
967 static bool validAtEntry(const MachineInstr *MInsn) {
968 auto MBB = MInsn->getParent();
969 // Is it in the entry basic block?
970 if (!MBB->pred_empty())
972 for (MachineBasicBlock::const_reverse_iterator I(MInsn); I != MBB->rend(); ++I)
973 if (!(I->isDebugValue() || I->getFlag(MachineInstr::FrameSetup)))
978 // Find variables for each lexical scope.
979 void DwarfDebug::collectVariableInfo(DwarfCompileUnit &TheCU,
980 const DISubprogram *SP,
981 DenseSet<InlinedVariable> &Processed) {
982 // Grab the variable info that was squirreled away in the MMI side-table.
983 collectVariableInfoFromMFTable(Processed);
985 for (const auto &I : DbgValues) {
986 InlinedVariable IV = I.first;
987 if (Processed.count(IV))
990 // Instruction ranges, specifying where IV is accessible.
991 const auto &Ranges = I.second;
995 LexicalScope *Scope = nullptr;
996 if (const DILocation *IA = IV.second)
997 Scope = LScopes.findInlinedScope(IV.first->getScope(), IA);
999 Scope = LScopes.findLexicalScope(IV.first->getScope());
1000 // If variable scope is not found then skip this variable.
1004 Processed.insert(IV);
1005 DbgVariable *RegVar = createConcreteVariable(*Scope, IV);
1007 const MachineInstr *MInsn = Ranges.front().first;
1008 assert(MInsn->isDebugValue() && "History must begin with debug value");
1010 // Check if there is a single DBG_VALUE, valid throughout the function.
1011 // A single constant is also considered valid for the entire function.
1012 if (Ranges.size() == 1 &&
1013 (MInsn->getOperand(0).isImm() ||
1014 (validAtEntry(MInsn) && Ranges.front().second == nullptr))) {
1015 RegVar->initializeDbgValue(MInsn);
1019 // Handle multiple DBG_VALUE instructions describing one variable.
1020 DebugLocStream::ListBuilder List(DebugLocs, TheCU, *Asm, *RegVar, *MInsn);
1022 // Build the location list for this variable.
1023 SmallVector<DebugLocEntry, 8> Entries;
1024 buildLocationList(Entries, Ranges);
1026 // If the variable has a DIBasicType, extract it. Basic types cannot have
1027 // unique identifiers, so don't bother resolving the type with the
1029 const DIBasicType *BT = dyn_cast<DIBasicType>(
1030 static_cast<const Metadata *>(IV.first->getType()));
1032 // Finalize the entry by lowering it into a DWARF bytestream.
1033 for (auto &Entry : Entries)
1034 Entry.finalize(*Asm, List, BT);
1037 // Collect info for variables that were optimized out.
1038 for (const DILocalVariable *DV : SP->getVariables()) {
1039 if (Processed.insert(InlinedVariable(DV, nullptr)).second)
1040 if (LexicalScope *Scope = LScopes.findLexicalScope(DV->getScope()))
1041 createConcreteVariable(*Scope, InlinedVariable(DV, nullptr));
1045 // Process beginning of an instruction.
1046 void DwarfDebug::beginInstruction(const MachineInstr *MI) {
1047 DebugHandlerBase::beginInstruction(MI);
1050 // Check if source location changes, but ignore DBG_VALUE and CFI locations.
1051 if (MI->isDebugValue() || MI->isCFIInstruction())
1053 const DebugLoc &DL = MI->getDebugLoc();
1054 // When we emit a line-0 record, we don't update PrevInstLoc; so look at
1055 // the last line number actually emitted, to see if it was line 0.
1056 unsigned LastAsmLine =
1057 Asm->OutStreamer->getContext().getCurrentDwarfLoc().getLine();
1059 if (DL == PrevInstLoc) {
1060 // If we have an ongoing unspecified location, nothing to do here.
1063 // We have an explicit location, same as the previous location.
1064 // But we might be coming back to it after a line 0 record.
1065 if (LastAsmLine == 0 && DL.getLine() != 0) {
1066 // Reinstate the source location but not marked as a statement.
1067 const MDNode *Scope = DL.getScope();
1068 recordSourceLine(DL.getLine(), DL.getCol(), Scope, /*Flags=*/0);
1074 // We have an unspecified location, which might want to be line 0.
1075 // If we have already emitted a line-0 record, don't repeat it.
1076 if (LastAsmLine == 0)
1078 // If user said Don't Do That, don't do that.
1079 if (UnknownLocations == Disable)
1081 // See if we have a reason to emit a line-0 record now.
1082 // Reasons to emit a line-0 record include:
1083 // - User asked for it (UnknownLocations).
1084 // - Instruction has a label, so it's referenced from somewhere else,
1085 // possibly debug information; we want it to have a source location.
1086 // - Instruction is at the top of a block; we don't want to inherit the
1087 // location from the physically previous (maybe unrelated) block.
1088 if (UnknownLocations == Enable || PrevLabel ||
1089 (PrevInstBB && PrevInstBB != MI->getParent())) {
1090 // Preserve the file and column numbers, if we can, to save space in
1091 // the encoded line table.
1092 // Do not update PrevInstLoc, it remembers the last non-0 line.
1093 const MDNode *Scope = nullptr;
1094 unsigned Column = 0;
1096 Scope = PrevInstLoc.getScope();
1097 Column = PrevInstLoc.getCol();
1099 recordSourceLine(/*Line=*/0, Column, Scope, /*Flags=*/0);
1104 // We have an explicit location, different from the previous location.
1105 // Don't repeat a line-0 record, but otherwise emit the new location.
1106 // (The new location might be an explicit line 0, which we do emit.)
1107 if (PrevInstLoc && DL.getLine() == 0 && LastAsmLine == 0)
1110 if (DL == PrologEndLoc) {
1111 Flags |= DWARF2_FLAG_PROLOGUE_END | DWARF2_FLAG_IS_STMT;
1112 PrologEndLoc = DebugLoc();
1114 // If the line changed, we call that a new statement; unless we went to
1115 // line 0 and came back, in which case it is not a new statement.
1116 unsigned OldLine = PrevInstLoc ? PrevInstLoc.getLine() : LastAsmLine;
1117 if (DL.getLine() && DL.getLine() != OldLine)
1118 Flags |= DWARF2_FLAG_IS_STMT;
1120 const MDNode *Scope = DL.getScope();
1121 recordSourceLine(DL.getLine(), DL.getCol(), Scope, Flags);
1123 // If we're not at line 0, remember this location.
1128 static DebugLoc findPrologueEndLoc(const MachineFunction *MF) {
1129 // First known non-DBG_VALUE and non-frame setup location marks
1130 // the beginning of the function body.
1131 for (const auto &MBB : *MF)
1132 for (const auto &MI : MBB)
1133 if (!MI.isDebugValue() && !MI.getFlag(MachineInstr::FrameSetup) &&
1135 return MI.getDebugLoc();
1139 // Gather pre-function debug information. Assumes being called immediately
1140 // after the function entry point has been emitted.
1141 void DwarfDebug::beginFunctionImpl(const MachineFunction *MF) {
1144 if (LScopes.empty())
1147 // Set DwarfDwarfCompileUnitID in MCContext to the Compile Unit this function
1148 // belongs to so that we add to the correct per-cu line table in the
1150 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1151 // FnScope->getScopeNode() and DI->second should represent the same function,
1152 // though they may not be the same MDNode due to inline functions merged in
1153 // LTO where the debug info metadata still differs (either due to distinct
1154 // written differences - two versions of a linkonce_odr function
1155 // written/copied into two separate files, or some sub-optimal metadata that
1156 // isn't structurally identical (see: file path/name info from clang, which
1157 // includes the directory of the cpp file being built, even when the file name
1158 // is absolute (such as an <> lookup header)))
1159 auto *SP = cast<DISubprogram>(FnScope->getScopeNode());
1160 DwarfCompileUnit *TheCU = CUMap.lookup(SP->getUnit());
1162 assert(SP->getUnit()->getEmissionKind() == DICompileUnit::NoDebug &&
1163 "DICompileUnit missing from llvm.dbg.cu?");
1166 if (Asm->OutStreamer->hasRawTextSupport())
1167 // Use a single line table if we are generating assembly.
1168 Asm->OutStreamer->getContext().setDwarfCompileUnitID(0);
1170 Asm->OutStreamer->getContext().setDwarfCompileUnitID(TheCU->getUniqueID());
1172 // Record beginning of function.
1173 PrologEndLoc = findPrologueEndLoc(MF);
1174 if (DILocation *L = PrologEndLoc) {
1175 // We'd like to list the prologue as "not statements" but GDB behaves
1176 // poorly if we do that. Revisit this with caution/GDB (7.5+) testing.
1177 auto *SP = L->getInlinedAtScope()->getSubprogram();
1178 recordSourceLine(SP->getScopeLine(), 0, SP, DWARF2_FLAG_IS_STMT);
1182 void DwarfDebug::skippedNonDebugFunction() {
1183 // If we don't have a subprogram for this function then there will be a hole
1184 // in the range information. Keep note of this by setting the previously used
1185 // section to nullptr.
1190 // Gather and emit post-function debug information.
1191 void DwarfDebug::endFunctionImpl(const MachineFunction *MF) {
1192 const DISubprogram *SP = MF->getFunction()->getSubprogram();
1194 assert(CurFn == MF &&
1195 "endFunction should be called with the same function as beginFunction");
1197 // Set DwarfDwarfCompileUnitID in MCContext to default value.
1198 Asm->OutStreamer->getContext().setDwarfCompileUnitID(0);
1200 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1201 assert(!FnScope || SP == FnScope->getScopeNode());
1202 DwarfCompileUnit &TheCU = *CUMap.lookup(SP->getUnit());
1204 DenseSet<InlinedVariable> ProcessedVars;
1205 collectVariableInfo(TheCU, SP, ProcessedVars);
1207 // Add the range of this function to the list of ranges for the CU.
1208 TheCU.addRange(RangeSpan(Asm->getFunctionBegin(), Asm->getFunctionEnd()));
1210 // Under -gmlt, skip building the subprogram if there are no inlined
1211 // subroutines inside it. But with -fdebug-info-for-profiling, the subprogram
1212 // is still needed as we need its source location.
1213 if (!TheCU.getCUNode()->getDebugInfoForProfiling() &&
1214 TheCU.getCUNode()->getEmissionKind() == DICompileUnit::LineTablesOnly &&
1215 LScopes.getAbstractScopesList().empty() && !IsDarwin) {
1216 assert(InfoHolder.getScopeVariables().empty());
1217 PrevLabel = nullptr;
1223 size_t NumAbstractScopes = LScopes.getAbstractScopesList().size();
1225 // Construct abstract scopes.
1226 for (LexicalScope *AScope : LScopes.getAbstractScopesList()) {
1227 auto *SP = cast<DISubprogram>(AScope->getScopeNode());
1228 // Collect info for variables that were optimized out.
1229 for (const DILocalVariable *DV : SP->getVariables()) {
1230 if (!ProcessedVars.insert(InlinedVariable(DV, nullptr)).second)
1232 ensureAbstractVariableIsCreated(InlinedVariable(DV, nullptr),
1234 assert(LScopes.getAbstractScopesList().size() == NumAbstractScopes
1235 && "ensureAbstractVariableIsCreated inserted abstract scopes");
1237 constructAbstractSubprogramScopeDIE(AScope);
1240 ProcessedSPNodes.insert(SP);
1241 TheCU.constructSubprogramScopeDIE(SP, FnScope);
1242 if (auto *SkelCU = TheCU.getSkeleton())
1243 if (!LScopes.getAbstractScopesList().empty() &&
1244 TheCU.getCUNode()->getSplitDebugInlining())
1245 SkelCU->constructSubprogramScopeDIE(SP, FnScope);
1248 // Ownership of DbgVariables is a bit subtle - ScopeVariables owns all the
1249 // DbgVariables except those that are also in AbstractVariables (since they
1250 // can be used cross-function)
1251 InfoHolder.getScopeVariables().clear();
1252 PrevLabel = nullptr;
1256 // Register a source line with debug info. Returns the unique label that was
1257 // emitted and which provides correspondence to the source line list.
1258 void DwarfDebug::recordSourceLine(unsigned Line, unsigned Col, const MDNode *S,
1263 unsigned Discriminator = 0;
1264 if (auto *Scope = cast_or_null<DIScope>(S)) {
1265 Fn = Scope->getFilename();
1266 Dir = Scope->getDirectory();
1267 if (auto *LBF = dyn_cast<DILexicalBlockFile>(Scope))
1268 if (getDwarfVersion() >= 4)
1269 Discriminator = LBF->getDiscriminator();
1271 unsigned CUID = Asm->OutStreamer->getContext().getDwarfCompileUnitID();
1272 Src = static_cast<DwarfCompileUnit &>(*InfoHolder.getUnits()[CUID])
1273 .getOrCreateSourceID(Fn, Dir);
1275 Asm->OutStreamer->EmitDwarfLocDirective(Src, Line, Col, Flags, 0,
1279 //===----------------------------------------------------------------------===//
1281 //===----------------------------------------------------------------------===//
1283 // Emit the debug info section.
1284 void DwarfDebug::emitDebugInfo() {
1285 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1286 Holder.emitUnits(/* UseOffsets */ false);
1289 // Emit the abbreviation section.
1290 void DwarfDebug::emitAbbreviations() {
1291 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1293 Holder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevSection());
1296 void DwarfDebug::emitAccel(DwarfAccelTable &Accel, MCSection *Section,
1297 StringRef TableName) {
1298 Accel.FinalizeTable(Asm, TableName);
1299 Asm->OutStreamer->SwitchSection(Section);
1301 // Emit the full data.
1302 Accel.emit(Asm, Section->getBeginSymbol(), this);
1305 // Emit visible names into a hashed accelerator table section.
1306 void DwarfDebug::emitAccelNames() {
1307 emitAccel(AccelNames, Asm->getObjFileLowering().getDwarfAccelNamesSection(),
1311 // Emit objective C classes and categories into a hashed accelerator table
1313 void DwarfDebug::emitAccelObjC() {
1314 emitAccel(AccelObjC, Asm->getObjFileLowering().getDwarfAccelObjCSection(),
1318 // Emit namespace dies into a hashed accelerator table.
1319 void DwarfDebug::emitAccelNamespaces() {
1320 emitAccel(AccelNamespace,
1321 Asm->getObjFileLowering().getDwarfAccelNamespaceSection(),
1325 // Emit type dies into a hashed accelerator table.
1326 void DwarfDebug::emitAccelTypes() {
1327 emitAccel(AccelTypes, Asm->getObjFileLowering().getDwarfAccelTypesSection(),
1331 // Public name handling.
1332 // The format for the various pubnames:
1334 // dwarf pubnames - offset/name pairs where the offset is the offset into the CU
1335 // for the DIE that is named.
1337 // gnu pubnames - offset/index value/name tuples where the offset is the offset
1338 // into the CU and the index value is computed according to the type of value
1339 // for the DIE that is named.
1341 // For type units the offset is the offset of the skeleton DIE. For split dwarf
1342 // it's the offset within the debug_info/debug_types dwo section, however, the
1343 // reference in the pubname header doesn't change.
1345 /// computeIndexValue - Compute the gdb index value for the DIE and CU.
1346 static dwarf::PubIndexEntryDescriptor computeIndexValue(DwarfUnit *CU,
1348 // Entities that ended up only in a Type Unit reference the CU instead (since
1349 // the pub entry has offsets within the CU there's no real offset that can be
1350 // provided anyway). As it happens all such entities (namespaces and types,
1351 // types only in C++ at that) are rendered as TYPE+EXTERNAL. If this turns out
1352 // not to be true it would be necessary to persist this information from the
1353 // point at which the entry is added to the index data structure - since by
1354 // the time the index is built from that, the original type/namespace DIE in a
1355 // type unit has already been destroyed so it can't be queried for properties
1357 if (Die->getTag() == dwarf::DW_TAG_compile_unit)
1358 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_TYPE,
1359 dwarf::GIEL_EXTERNAL);
1360 dwarf::GDBIndexEntryLinkage Linkage = dwarf::GIEL_STATIC;
1362 // We could have a specification DIE that has our most of our knowledge,
1363 // look for that now.
1364 if (DIEValue SpecVal = Die->findAttribute(dwarf::DW_AT_specification)) {
1365 DIE &SpecDIE = SpecVal.getDIEEntry().getEntry();
1366 if (SpecDIE.findAttribute(dwarf::DW_AT_external))
1367 Linkage = dwarf::GIEL_EXTERNAL;
1368 } else if (Die->findAttribute(dwarf::DW_AT_external))
1369 Linkage = dwarf::GIEL_EXTERNAL;
1371 switch (Die->getTag()) {
1372 case dwarf::DW_TAG_class_type:
1373 case dwarf::DW_TAG_structure_type:
1374 case dwarf::DW_TAG_union_type:
1375 case dwarf::DW_TAG_enumeration_type:
1376 return dwarf::PubIndexEntryDescriptor(
1377 dwarf::GIEK_TYPE, CU->getLanguage() != dwarf::DW_LANG_C_plus_plus
1378 ? dwarf::GIEL_STATIC
1379 : dwarf::GIEL_EXTERNAL);
1380 case dwarf::DW_TAG_typedef:
1381 case dwarf::DW_TAG_base_type:
1382 case dwarf::DW_TAG_subrange_type:
1383 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_TYPE, dwarf::GIEL_STATIC);
1384 case dwarf::DW_TAG_namespace:
1385 return dwarf::GIEK_TYPE;
1386 case dwarf::DW_TAG_subprogram:
1387 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_FUNCTION, Linkage);
1388 case dwarf::DW_TAG_variable:
1389 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE, Linkage);
1390 case dwarf::DW_TAG_enumerator:
1391 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE,
1392 dwarf::GIEL_STATIC);
1394 return dwarf::GIEK_NONE;
1398 /// emitDebugPubNames - Emit visible names into a debug pubnames section.
1400 void DwarfDebug::emitDebugPubNames(bool GnuStyle) {
1401 MCSection *PSec = GnuStyle
1402 ? Asm->getObjFileLowering().getDwarfGnuPubNamesSection()
1403 : Asm->getObjFileLowering().getDwarfPubNamesSection();
1405 emitDebugPubSection(GnuStyle, PSec, "Names",
1406 &DwarfCompileUnit::getGlobalNames);
1409 void DwarfDebug::emitDebugPubSection(
1410 bool GnuStyle, MCSection *PSec, StringRef Name,
1411 const StringMap<const DIE *> &(DwarfCompileUnit::*Accessor)() const) {
1412 for (const auto &NU : CUMap) {
1413 DwarfCompileUnit *TheU = NU.second;
1415 const auto &Globals = (TheU->*Accessor)();
1417 if (Globals.empty())
1420 if (auto *Skeleton = TheU->getSkeleton())
1423 // Start the dwarf pubnames section.
1424 Asm->OutStreamer->SwitchSection(PSec);
1427 Asm->OutStreamer->AddComment("Length of Public " + Name + " Info");
1428 MCSymbol *BeginLabel = Asm->createTempSymbol("pub" + Name + "_begin");
1429 MCSymbol *EndLabel = Asm->createTempSymbol("pub" + Name + "_end");
1430 Asm->EmitLabelDifference(EndLabel, BeginLabel, 4);
1432 Asm->OutStreamer->EmitLabel(BeginLabel);
1434 Asm->OutStreamer->AddComment("DWARF Version");
1435 Asm->EmitInt16(dwarf::DW_PUBNAMES_VERSION);
1437 Asm->OutStreamer->AddComment("Offset of Compilation Unit Info");
1438 Asm->emitDwarfSymbolReference(TheU->getLabelBegin());
1440 Asm->OutStreamer->AddComment("Compilation Unit Length");
1441 Asm->EmitInt32(TheU->getLength());
1443 // Emit the pubnames for this compilation unit.
1444 for (const auto &GI : Globals) {
1445 const char *Name = GI.getKeyData();
1446 const DIE *Entity = GI.second;
1448 Asm->OutStreamer->AddComment("DIE offset");
1449 Asm->EmitInt32(Entity->getOffset());
1452 dwarf::PubIndexEntryDescriptor Desc = computeIndexValue(TheU, Entity);
1453 Asm->OutStreamer->AddComment(
1454 Twine("Kind: ") + dwarf::GDBIndexEntryKindString(Desc.Kind) + ", " +
1455 dwarf::GDBIndexEntryLinkageString(Desc.Linkage));
1456 Asm->EmitInt8(Desc.toBits());
1459 Asm->OutStreamer->AddComment("External Name");
1460 Asm->OutStreamer->EmitBytes(StringRef(Name, GI.getKeyLength() + 1));
1463 Asm->OutStreamer->AddComment("End Mark");
1465 Asm->OutStreamer->EmitLabel(EndLabel);
1469 void DwarfDebug::emitDebugPubTypes(bool GnuStyle) {
1470 MCSection *PSec = GnuStyle
1471 ? Asm->getObjFileLowering().getDwarfGnuPubTypesSection()
1472 : Asm->getObjFileLowering().getDwarfPubTypesSection();
1474 emitDebugPubSection(GnuStyle, PSec, "Types",
1475 &DwarfCompileUnit::getGlobalTypes);
1478 /// Emit null-terminated strings into a debug str section.
1479 void DwarfDebug::emitDebugStr() {
1480 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1481 Holder.emitStrings(Asm->getObjFileLowering().getDwarfStrSection());
1484 void DwarfDebug::emitDebugLocEntry(ByteStreamer &Streamer,
1485 const DebugLocStream::Entry &Entry) {
1486 auto &&Comments = DebugLocs.getComments(Entry);
1487 auto Comment = Comments.begin();
1488 auto End = Comments.end();
1489 for (uint8_t Byte : DebugLocs.getBytes(Entry))
1490 Streamer.EmitInt8(Byte, Comment != End ? *(Comment++) : "");
1493 static void emitDebugLocValue(const AsmPrinter &AP, const DIBasicType *BT,
1494 ByteStreamer &Streamer,
1495 const DebugLocEntry::Value &Value,
1496 DwarfExpression &DwarfExpr) {
1497 auto *DIExpr = Value.getExpression();
1498 DIExpressionCursor ExprCursor(DIExpr);
1499 DwarfExpr.addFragmentOffset(DIExpr);
1501 if (Value.isInt()) {
1502 if (BT && (BT->getEncoding() == dwarf::DW_ATE_signed ||
1503 BT->getEncoding() == dwarf::DW_ATE_signed_char))
1504 DwarfExpr.addSignedConstant(Value.getInt());
1506 DwarfExpr.addUnsignedConstant(Value.getInt());
1507 } else if (Value.isLocation()) {
1508 MachineLocation Location = Value.getLoc();
1509 if (Location.isIndirect())
1510 DwarfExpr.setMemoryLocationKind();
1511 SmallVector<uint64_t, 8> Ops;
1512 if (Location.isIndirect() && Location.getOffset()) {
1513 Ops.push_back(dwarf::DW_OP_plus);
1514 Ops.push_back(Location.getOffset());
1516 Ops.append(DIExpr->elements_begin(), DIExpr->elements_end());
1517 DIExpressionCursor Cursor(Ops);
1518 const TargetRegisterInfo &TRI = *AP.MF->getSubtarget().getRegisterInfo();
1519 if (!DwarfExpr.addMachineRegExpression(TRI, Cursor, Location.getReg()))
1521 return DwarfExpr.addExpression(std::move(Cursor));
1522 } else if (Value.isConstantFP()) {
1523 APInt RawBytes = Value.getConstantFP()->getValueAPF().bitcastToAPInt();
1524 DwarfExpr.addUnsignedConstant(RawBytes);
1526 DwarfExpr.addExpression(std::move(ExprCursor));
1529 void DebugLocEntry::finalize(const AsmPrinter &AP,
1530 DebugLocStream::ListBuilder &List,
1531 const DIBasicType *BT) {
1532 DebugLocStream::EntryBuilder Entry(List, Begin, End);
1533 BufferByteStreamer Streamer = Entry.getStreamer();
1534 DebugLocDwarfExpression DwarfExpr(AP.getDwarfVersion(), Streamer);
1535 const DebugLocEntry::Value &Value = Values[0];
1536 if (Value.isFragment()) {
1537 // Emit all fragments that belong to the same variable and range.
1538 assert(all_of(Values, [](DebugLocEntry::Value P) {
1539 return P.isFragment();
1540 }) && "all values are expected to be fragments");
1541 assert(std::is_sorted(Values.begin(), Values.end()) &&
1542 "fragments are expected to be sorted");
1544 for (auto Fragment : Values)
1545 emitDebugLocValue(AP, BT, Streamer, Fragment, DwarfExpr);
1548 assert(Values.size() == 1 && "only fragments may have >1 value");
1549 emitDebugLocValue(AP, BT, Streamer, Value, DwarfExpr);
1551 DwarfExpr.finalize();
1554 void DwarfDebug::emitDebugLocEntryLocation(const DebugLocStream::Entry &Entry) {
1556 Asm->OutStreamer->AddComment("Loc expr size");
1557 Asm->EmitInt16(DebugLocs.getBytes(Entry).size());
1560 APByteStreamer Streamer(*Asm);
1561 emitDebugLocEntry(Streamer, Entry);
1564 // Emit locations into the debug loc section.
1565 void DwarfDebug::emitDebugLoc() {
1566 // Start the dwarf loc section.
1567 Asm->OutStreamer->SwitchSection(
1568 Asm->getObjFileLowering().getDwarfLocSection());
1569 unsigned char Size = Asm->MAI->getCodePointerSize();
1570 for (const auto &List : DebugLocs.getLists()) {
1571 Asm->OutStreamer->EmitLabel(List.Label);
1572 const DwarfCompileUnit *CU = List.CU;
1573 for (const auto &Entry : DebugLocs.getEntries(List)) {
1574 // Set up the range. This range is relative to the entry point of the
1575 // compile unit. This is a hard coded 0 for low_pc when we're emitting
1576 // ranges, or the DW_AT_low_pc on the compile unit otherwise.
1577 if (auto *Base = CU->getBaseAddress()) {
1578 Asm->EmitLabelDifference(Entry.BeginSym, Base, Size);
1579 Asm->EmitLabelDifference(Entry.EndSym, Base, Size);
1581 Asm->OutStreamer->EmitSymbolValue(Entry.BeginSym, Size);
1582 Asm->OutStreamer->EmitSymbolValue(Entry.EndSym, Size);
1585 emitDebugLocEntryLocation(Entry);
1587 Asm->OutStreamer->EmitIntValue(0, Size);
1588 Asm->OutStreamer->EmitIntValue(0, Size);
1592 void DwarfDebug::emitDebugLocDWO() {
1593 Asm->OutStreamer->SwitchSection(
1594 Asm->getObjFileLowering().getDwarfLocDWOSection());
1595 for (const auto &List : DebugLocs.getLists()) {
1596 Asm->OutStreamer->EmitLabel(List.Label);
1597 for (const auto &Entry : DebugLocs.getEntries(List)) {
1598 // Just always use start_length for now - at least that's one address
1599 // rather than two. We could get fancier and try to, say, reuse an
1600 // address we know we've emitted elsewhere (the start of the function?
1601 // The start of the CU or CU subrange that encloses this range?)
1602 Asm->EmitInt8(dwarf::DW_LLE_startx_length);
1603 unsigned idx = AddrPool.getIndex(Entry.BeginSym);
1604 Asm->EmitULEB128(idx);
1605 Asm->EmitLabelDifference(Entry.EndSym, Entry.BeginSym, 4);
1607 emitDebugLocEntryLocation(Entry);
1609 Asm->EmitInt8(dwarf::DW_LLE_end_of_list);
1614 const MCSymbol *Start, *End;
1617 // Emit a debug aranges section, containing a CU lookup for any
1618 // address we can tie back to a CU.
1619 void DwarfDebug::emitDebugARanges() {
1620 // Provides a unique id per text section.
1621 MapVector<MCSection *, SmallVector<SymbolCU, 8>> SectionMap;
1623 // Filter labels by section.
1624 for (const SymbolCU &SCU : ArangeLabels) {
1625 if (SCU.Sym->isInSection()) {
1626 // Make a note of this symbol and it's section.
1627 MCSection *Section = &SCU.Sym->getSection();
1628 if (!Section->getKind().isMetadata())
1629 SectionMap[Section].push_back(SCU);
1631 // Some symbols (e.g. common/bss on mach-o) can have no section but still
1632 // appear in the output. This sucks as we rely on sections to build
1633 // arange spans. We can do it without, but it's icky.
1634 SectionMap[nullptr].push_back(SCU);
1638 DenseMap<DwarfCompileUnit *, std::vector<ArangeSpan>> Spans;
1640 for (auto &I : SectionMap) {
1641 MCSection *Section = I.first;
1642 SmallVector<SymbolCU, 8> &List = I.second;
1643 if (List.size() < 1)
1646 // If we have no section (e.g. common), just write out
1647 // individual spans for each symbol.
1649 for (const SymbolCU &Cur : List) {
1651 Span.Start = Cur.Sym;
1654 Spans[Cur.CU].push_back(Span);
1659 // Sort the symbols by offset within the section.
1661 List.begin(), List.end(), [&](const SymbolCU &A, const SymbolCU &B) {
1662 unsigned IA = A.Sym ? Asm->OutStreamer->GetSymbolOrder(A.Sym) : 0;
1663 unsigned IB = B.Sym ? Asm->OutStreamer->GetSymbolOrder(B.Sym) : 0;
1665 // Symbols with no order assigned should be placed at the end.
1666 // (e.g. section end labels)
1674 // Insert a final terminator.
1675 List.push_back(SymbolCU(nullptr, Asm->OutStreamer->endSection(Section)));
1677 // Build spans between each label.
1678 const MCSymbol *StartSym = List[0].Sym;
1679 for (size_t n = 1, e = List.size(); n < e; n++) {
1680 const SymbolCU &Prev = List[n - 1];
1681 const SymbolCU &Cur = List[n];
1683 // Try and build the longest span we can within the same CU.
1684 if (Cur.CU != Prev.CU) {
1686 Span.Start = StartSym;
1689 Spans[Prev.CU].push_back(Span);
1695 // Start the dwarf aranges section.
1696 Asm->OutStreamer->SwitchSection(
1697 Asm->getObjFileLowering().getDwarfARangesSection());
1699 unsigned PtrSize = Asm->MAI->getCodePointerSize();
1701 // Build a list of CUs used.
1702 std::vector<DwarfCompileUnit *> CUs;
1703 for (const auto &it : Spans) {
1704 DwarfCompileUnit *CU = it.first;
1708 // Sort the CU list (again, to ensure consistent output order).
1709 std::sort(CUs.begin(), CUs.end(),
1710 [](const DwarfCompileUnit *A, const DwarfCompileUnit *B) {
1711 return A->getUniqueID() < B->getUniqueID();
1714 // Emit an arange table for each CU we used.
1715 for (DwarfCompileUnit *CU : CUs) {
1716 std::vector<ArangeSpan> &List = Spans[CU];
1718 // Describe the skeleton CU's offset and length, not the dwo file's.
1719 if (auto *Skel = CU->getSkeleton())
1722 // Emit size of content not including length itself.
1723 unsigned ContentSize =
1724 sizeof(int16_t) + // DWARF ARange version number
1725 sizeof(int32_t) + // Offset of CU in the .debug_info section
1726 sizeof(int8_t) + // Pointer Size (in bytes)
1727 sizeof(int8_t); // Segment Size (in bytes)
1729 unsigned TupleSize = PtrSize * 2;
1731 // 7.20 in the Dwarf specs requires the table to be aligned to a tuple.
1733 OffsetToAlignment(sizeof(int32_t) + ContentSize, TupleSize);
1735 ContentSize += Padding;
1736 ContentSize += (List.size() + 1) * TupleSize;
1738 // For each compile unit, write the list of spans it covers.
1739 Asm->OutStreamer->AddComment("Length of ARange Set");
1740 Asm->EmitInt32(ContentSize);
1741 Asm->OutStreamer->AddComment("DWARF Arange version number");
1742 Asm->EmitInt16(dwarf::DW_ARANGES_VERSION);
1743 Asm->OutStreamer->AddComment("Offset Into Debug Info Section");
1744 Asm->emitDwarfSymbolReference(CU->getLabelBegin());
1745 Asm->OutStreamer->AddComment("Address Size (in bytes)");
1746 Asm->EmitInt8(PtrSize);
1747 Asm->OutStreamer->AddComment("Segment Size (in bytes)");
1750 Asm->OutStreamer->emitFill(Padding, 0xff);
1752 for (const ArangeSpan &Span : List) {
1753 Asm->EmitLabelReference(Span.Start, PtrSize);
1755 // Calculate the size as being from the span start to it's end.
1757 Asm->EmitLabelDifference(Span.End, Span.Start, PtrSize);
1759 // For symbols without an end marker (e.g. common), we
1760 // write a single arange entry containing just that one symbol.
1761 uint64_t Size = SymSize[Span.Start];
1765 Asm->OutStreamer->EmitIntValue(Size, PtrSize);
1769 Asm->OutStreamer->AddComment("ARange terminator");
1770 Asm->OutStreamer->EmitIntValue(0, PtrSize);
1771 Asm->OutStreamer->EmitIntValue(0, PtrSize);
1775 /// Emit address ranges into a debug ranges section.
1776 void DwarfDebug::emitDebugRanges() {
1777 // Start the dwarf ranges section.
1778 Asm->OutStreamer->SwitchSection(
1779 Asm->getObjFileLowering().getDwarfRangesSection());
1781 // Size for our labels.
1782 unsigned char Size = Asm->MAI->getCodePointerSize();
1784 // Grab the specific ranges for the compile units in the module.
1785 for (const auto &I : CUMap) {
1786 DwarfCompileUnit *TheCU = I.second;
1788 if (auto *Skel = TheCU->getSkeleton())
1791 // Iterate over the misc ranges for the compile units in the module.
1792 for (const RangeSpanList &List : TheCU->getRangeLists()) {
1793 // Emit our symbol so we can find the beginning of the range.
1794 Asm->OutStreamer->EmitLabel(List.getSym());
1796 for (const RangeSpan &Range : List.getRanges()) {
1797 const MCSymbol *Begin = Range.getStart();
1798 const MCSymbol *End = Range.getEnd();
1799 assert(Begin && "Range without a begin symbol?");
1800 assert(End && "Range without an end symbol?");
1801 if (auto *Base = TheCU->getBaseAddress()) {
1802 Asm->EmitLabelDifference(Begin, Base, Size);
1803 Asm->EmitLabelDifference(End, Base, Size);
1805 Asm->OutStreamer->EmitSymbolValue(Begin, Size);
1806 Asm->OutStreamer->EmitSymbolValue(End, Size);
1810 // And terminate the list with two 0 values.
1811 Asm->OutStreamer->EmitIntValue(0, Size);
1812 Asm->OutStreamer->EmitIntValue(0, Size);
1817 void DwarfDebug::handleMacroNodes(DIMacroNodeArray Nodes, DwarfCompileUnit &U) {
1818 for (auto *MN : Nodes) {
1819 if (auto *M = dyn_cast<DIMacro>(MN))
1821 else if (auto *F = dyn_cast<DIMacroFile>(MN))
1822 emitMacroFile(*F, U);
1824 llvm_unreachable("Unexpected DI type!");
1828 void DwarfDebug::emitMacro(DIMacro &M) {
1829 Asm->EmitULEB128(M.getMacinfoType());
1830 Asm->EmitULEB128(M.getLine());
1831 StringRef Name = M.getName();
1832 StringRef Value = M.getValue();
1833 Asm->OutStreamer->EmitBytes(Name);
1834 if (!Value.empty()) {
1835 // There should be one space between macro name and macro value.
1837 Asm->OutStreamer->EmitBytes(Value);
1839 Asm->EmitInt8('\0');
1842 void DwarfDebug::emitMacroFile(DIMacroFile &F, DwarfCompileUnit &U) {
1843 assert(F.getMacinfoType() == dwarf::DW_MACINFO_start_file);
1844 Asm->EmitULEB128(dwarf::DW_MACINFO_start_file);
1845 Asm->EmitULEB128(F.getLine());
1846 DIFile *File = F.getFile();
1848 U.getOrCreateSourceID(File->getFilename(), File->getDirectory());
1849 Asm->EmitULEB128(FID);
1850 handleMacroNodes(F.getElements(), U);
1851 Asm->EmitULEB128(dwarf::DW_MACINFO_end_file);
1854 /// Emit macros into a debug macinfo section.
1855 void DwarfDebug::emitDebugMacinfo() {
1856 // Start the dwarf macinfo section.
1857 Asm->OutStreamer->SwitchSection(
1858 Asm->getObjFileLowering().getDwarfMacinfoSection());
1860 for (const auto &P : CUMap) {
1861 auto &TheCU = *P.second;
1862 auto *SkCU = TheCU.getSkeleton();
1863 DwarfCompileUnit &U = SkCU ? *SkCU : TheCU;
1864 auto *CUNode = cast<DICompileUnit>(P.first);
1865 Asm->OutStreamer->EmitLabel(U.getMacroLabelBegin());
1866 handleMacroNodes(CUNode->getMacros(), U);
1868 Asm->OutStreamer->AddComment("End Of Macro List Mark");
1872 // DWARF5 Experimental Separate Dwarf emitters.
1874 void DwarfDebug::initSkeletonUnit(const DwarfUnit &U, DIE &Die,
1875 std::unique_ptr<DwarfCompileUnit> NewU) {
1876 NewU->addString(Die, dwarf::DW_AT_GNU_dwo_name,
1877 Asm->TM.Options.MCOptions.SplitDwarfFile);
1879 if (!CompilationDir.empty())
1880 NewU->addString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
1882 addGnuPubAttributes(*NewU, Die);
1884 SkeletonHolder.addUnit(std::move(NewU));
1887 // This DIE has the following attributes: DW_AT_comp_dir, DW_AT_stmt_list,
1888 // DW_AT_low_pc, DW_AT_high_pc, DW_AT_ranges, DW_AT_dwo_name, DW_AT_dwo_id,
1889 // DW_AT_addr_base, DW_AT_ranges_base.
1890 DwarfCompileUnit &DwarfDebug::constructSkeletonCU(const DwarfCompileUnit &CU) {
1892 auto OwnedUnit = make_unique<DwarfCompileUnit>(
1893 CU.getUniqueID(), CU.getCUNode(), Asm, this, &SkeletonHolder);
1894 DwarfCompileUnit &NewCU = *OwnedUnit;
1895 NewCU.setSection(Asm->getObjFileLowering().getDwarfInfoSection());
1897 NewCU.initStmtList();
1899 initSkeletonUnit(CU, NewCU.getUnitDie(), std::move(OwnedUnit));
1904 // Emit the .debug_info.dwo section for separated dwarf. This contains the
1905 // compile units that would normally be in debug_info.
1906 void DwarfDebug::emitDebugInfoDWO() {
1907 assert(useSplitDwarf() && "No split dwarf debug info?");
1908 // Don't emit relocations into the dwo file.
1909 InfoHolder.emitUnits(/* UseOffsets */ true);
1912 // Emit the .debug_abbrev.dwo section for separated dwarf. This contains the
1913 // abbreviations for the .debug_info.dwo section.
1914 void DwarfDebug::emitDebugAbbrevDWO() {
1915 assert(useSplitDwarf() && "No split dwarf?");
1916 InfoHolder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevDWOSection());
1919 void DwarfDebug::emitDebugLineDWO() {
1920 assert(useSplitDwarf() && "No split dwarf?");
1921 Asm->OutStreamer->SwitchSection(
1922 Asm->getObjFileLowering().getDwarfLineDWOSection());
1923 SplitTypeUnitFileTable.Emit(*Asm->OutStreamer, MCDwarfLineTableParams());
1926 // Emit the .debug_str.dwo section for separated dwarf. This contains the
1927 // string section and is identical in format to traditional .debug_str
1929 void DwarfDebug::emitDebugStrDWO() {
1930 assert(useSplitDwarf() && "No split dwarf?");
1931 MCSection *OffSec = Asm->getObjFileLowering().getDwarfStrOffDWOSection();
1932 InfoHolder.emitStrings(Asm->getObjFileLowering().getDwarfStrDWOSection(),
1936 MCDwarfDwoLineTable *DwarfDebug::getDwoLineTable(const DwarfCompileUnit &CU) {
1937 if (!useSplitDwarf())
1940 SplitTypeUnitFileTable.setCompilationDir(CU.getCUNode()->getDirectory());
1941 return &SplitTypeUnitFileTable;
1944 uint64_t DwarfDebug::makeTypeSignature(StringRef Identifier) {
1946 Hash.update(Identifier);
1947 // ... take the least significant 8 bytes and return those. Our MD5
1948 // implementation always returns its results in little endian, so we actually
1949 // need the "high" word.
1950 MD5::MD5Result Result;
1952 return Result.high();
1955 void DwarfDebug::addDwarfTypeUnitType(DwarfCompileUnit &CU,
1956 StringRef Identifier, DIE &RefDie,
1957 const DICompositeType *CTy) {
1958 // Fast path if we're building some type units and one has already used the
1959 // address pool we know we're going to throw away all this work anyway, so
1960 // don't bother building dependent types.
1961 if (!TypeUnitsUnderConstruction.empty() && AddrPool.hasBeenUsed())
1964 auto Ins = TypeSignatures.insert(std::make_pair(CTy, 0));
1966 CU.addDIETypeSignature(RefDie, Ins.first->second);
1970 bool TopLevelType = TypeUnitsUnderConstruction.empty();
1971 AddrPool.resetUsedFlag();
1973 auto OwnedUnit = make_unique<DwarfTypeUnit>(CU, Asm, this, &InfoHolder,
1974 getDwoLineTable(CU));
1975 DwarfTypeUnit &NewTU = *OwnedUnit;
1976 DIE &UnitDie = NewTU.getUnitDie();
1977 TypeUnitsUnderConstruction.emplace_back(std::move(OwnedUnit), CTy);
1979 NewTU.addUInt(UnitDie, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
1982 uint64_t Signature = makeTypeSignature(Identifier);
1983 NewTU.setTypeSignature(Signature);
1984 Ins.first->second = Signature;
1986 if (useSplitDwarf())
1987 NewTU.setSection(Asm->getObjFileLowering().getDwarfTypesDWOSection());
1989 CU.applyStmtList(UnitDie);
1990 NewTU.setSection(Asm->getObjFileLowering().getDwarfTypesSection(Signature));
1993 NewTU.setType(NewTU.createTypeDIE(CTy));
1996 auto TypeUnitsToAdd = std::move(TypeUnitsUnderConstruction);
1997 TypeUnitsUnderConstruction.clear();
1999 // Types referencing entries in the address table cannot be placed in type
2001 if (AddrPool.hasBeenUsed()) {
2003 // Remove all the types built while building this type.
2004 // This is pessimistic as some of these types might not be dependent on
2005 // the type that used an address.
2006 for (const auto &TU : TypeUnitsToAdd)
2007 TypeSignatures.erase(TU.second);
2009 // Construct this type in the CU directly.
2010 // This is inefficient because all the dependent types will be rebuilt
2011 // from scratch, including building them in type units, discovering that
2012 // they depend on addresses, throwing them out and rebuilding them.
2013 CU.constructTypeDIE(RefDie, cast<DICompositeType>(CTy));
2017 // If the type wasn't dependent on fission addresses, finish adding the type
2018 // and all its dependent types.
2019 for (auto &TU : TypeUnitsToAdd) {
2020 InfoHolder.computeSizeAndOffsetsForUnit(TU.first.get());
2021 InfoHolder.emitUnit(TU.first.get(), useSplitDwarf());
2024 CU.addDIETypeSignature(RefDie, Signature);
2027 // Accelerator table mutators - add each name along with its companion
2028 // DIE to the proper table while ensuring that the name that we're going
2029 // to reference is in the string table. We do this since the names we
2030 // add may not only be identical to the names in the DIE.
2031 void DwarfDebug::addAccelName(StringRef Name, const DIE &Die) {
2032 if (!useDwarfAccelTables())
2034 AccelNames.AddName(InfoHolder.getStringPool().getEntry(*Asm, Name), &Die);
2037 void DwarfDebug::addAccelObjC(StringRef Name, const DIE &Die) {
2038 if (!useDwarfAccelTables())
2040 AccelObjC.AddName(InfoHolder.getStringPool().getEntry(*Asm, Name), &Die);
2043 void DwarfDebug::addAccelNamespace(StringRef Name, const DIE &Die) {
2044 if (!useDwarfAccelTables())
2046 AccelNamespace.AddName(InfoHolder.getStringPool().getEntry(*Asm, Name), &Die);
2049 void DwarfDebug::addAccelType(StringRef Name, const DIE &Die, char Flags) {
2050 if (!useDwarfAccelTables())
2052 AccelTypes.AddName(InfoHolder.getStringPool().getEntry(*Asm, Name), &Die);
2055 uint16_t DwarfDebug::getDwarfVersion() const {
2056 return Asm->OutStreamer->getContext().getDwarfVersion();