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(DIRef<T> Ref) const {
133 return DD->resolve(Ref);
136 bool DbgVariable::isBlockByrefVariable() const {
137 assert(Var.isVariable() && "Invalid complex DbgVariable!");
138 return Var.isBlockByrefVariable(DD->getTypeIdentifierMap());
141 DIType DbgVariable::getType() const {
142 DIType Ty = Var.getType().resolve(DD->getTypeIdentifierMap());
143 // FIXME: isBlockByrefVariable should be reformulated in terms of complex
144 // addresses instead.
145 if (Var.isBlockByrefVariable(DD->getTypeIdentifierMap())) {
146 /* Byref variables, in Blocks, are declared by the programmer as
147 "SomeType VarName;", but the compiler creates a
148 __Block_byref_x_VarName struct, and gives the variable VarName
149 either the struct, or a pointer to the struct, as its type. This
150 is necessary for various behind-the-scenes things the compiler
151 needs to do with by-reference variables in blocks.
153 However, as far as the original *programmer* is concerned, the
154 variable should still have type 'SomeType', as originally declared.
156 The following function dives into the __Block_byref_x_VarName
157 struct to find the original type of the variable. This will be
158 passed back to the code generating the type for the Debug
159 Information Entry for the variable 'VarName'. 'VarName' will then
160 have the original type 'SomeType' in its debug information.
162 The original type 'SomeType' will be the type of the field named
163 'VarName' inside the __Block_byref_x_VarName struct.
165 NOTE: In order for this to not completely fail on the debugger
166 side, the Debug Information Entry for the variable VarName needs to
167 have a DW_AT_location that tells the debugger how to unwind through
168 the pointers and __Block_byref_x_VarName struct to find the actual
169 value of the variable. The function addBlockByrefType does this. */
171 uint16_t tag = Ty.getTag();
173 if (tag == dwarf::DW_TAG_pointer_type)
174 subType = resolve(DIDerivedType(Ty).getTypeDerivedFrom());
176 DIArray Elements = DICompositeType(subType).getElements();
177 for (unsigned i = 0, N = Elements.getNumElements(); i < N; ++i) {
178 DIDerivedType DT(Elements.getElement(i));
179 if (getName() == DT.getName())
180 return (resolve(DT.getTypeDerivedFrom()));
186 static LLVM_CONSTEXPR DwarfAccelTable::Atom TypeAtoms[] = {
187 DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset, dwarf::DW_FORM_data4),
188 DwarfAccelTable::Atom(dwarf::DW_ATOM_die_tag, dwarf::DW_FORM_data2),
189 DwarfAccelTable::Atom(dwarf::DW_ATOM_type_flags, dwarf::DW_FORM_data1)};
191 DwarfDebug::DwarfDebug(AsmPrinter *A, Module *M)
192 : Asm(A), MMI(Asm->MMI), PrevLabel(nullptr),
193 InfoHolder(A, "info_string", DIEValueAllocator),
194 UsedNonDefaultText(false),
195 SkeletonHolder(A, "skel_string", DIEValueAllocator),
196 IsDarwin(Triple(A->getTargetTriple()).isOSDarwin()),
197 IsPS4(Triple(A->getTargetTriple()).isPS4()),
198 AccelNames(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
199 dwarf::DW_FORM_data4)),
200 AccelObjC(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
201 dwarf::DW_FORM_data4)),
202 AccelNamespace(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
203 dwarf::DW_FORM_data4)),
204 AccelTypes(TypeAtoms) {
209 // Turn on accelerator tables for Darwin by default, pubnames by
210 // default for non-Darwin/PS4, and handle split dwarf.
211 if (DwarfAccelTables == Default)
212 HasDwarfAccelTables = IsDarwin;
214 HasDwarfAccelTables = DwarfAccelTables == Enable;
216 if (SplitDwarf == Default)
217 HasSplitDwarf = false;
219 HasSplitDwarf = SplitDwarf == Enable;
221 if (DwarfPubSections == Default)
222 HasDwarfPubSections = !IsDarwin && !IsPS4;
224 HasDwarfPubSections = DwarfPubSections == Enable;
226 unsigned DwarfVersionNumber = Asm->TM.Options.MCOptions.DwarfVersion;
227 DwarfVersion = DwarfVersionNumber ? DwarfVersionNumber
228 : MMI->getModule()->getDwarfVersion();
230 // Darwin and PS4 use the standard TLS opcode (defined in DWARF 3).
231 // Everybody else uses GNU's.
232 UseGNUTLSOpcode = !(IsDarwin || IsPS4) || DwarfVersion < 3;
234 Asm->OutStreamer.getContext().setDwarfVersion(DwarfVersion);
237 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
242 // Define out of line so we don't have to include DwarfUnit.h in DwarfDebug.h.
243 DwarfDebug::~DwarfDebug() { }
245 static bool isObjCClass(StringRef Name) {
246 return Name.startswith("+") || Name.startswith("-");
249 static bool hasObjCCategory(StringRef Name) {
250 if (!isObjCClass(Name))
253 return Name.find(") ") != StringRef::npos;
256 static void getObjCClassCategory(StringRef In, StringRef &Class,
257 StringRef &Category) {
258 if (!hasObjCCategory(In)) {
259 Class = In.slice(In.find('[') + 1, In.find(' '));
264 Class = In.slice(In.find('[') + 1, In.find('('));
265 Category = In.slice(In.find('[') + 1, In.find(' '));
269 static StringRef getObjCMethodName(StringRef In) {
270 return In.slice(In.find(' ') + 1, In.find(']'));
273 // Add the various names to the Dwarf accelerator table names.
274 // TODO: Determine whether or not we should add names for programs
275 // that do not have a DW_AT_name or DW_AT_linkage_name field - this
276 // is only slightly different than the lookup of non-standard ObjC names.
277 void DwarfDebug::addSubprogramNames(DISubprogram SP, DIE &Die) {
278 if (!SP.isDefinition())
280 addAccelName(SP.getName(), Die);
282 // If the linkage name is different than the name, go ahead and output
283 // that as well into the name table.
284 if (SP.getLinkageName() != "" && SP.getName() != SP.getLinkageName())
285 addAccelName(SP.getLinkageName(), Die);
287 // If this is an Objective-C selector name add it to the ObjC accelerator
289 if (isObjCClass(SP.getName())) {
290 StringRef Class, Category;
291 getObjCClassCategory(SP.getName(), Class, Category);
292 addAccelObjC(Class, Die);
294 addAccelObjC(Category, Die);
295 // Also add the base method name to the name table.
296 addAccelName(getObjCMethodName(SP.getName()), Die);
300 /// isSubprogramContext - Return true if Context is either a subprogram
301 /// or another context nested inside a subprogram.
302 bool DwarfDebug::isSubprogramContext(const MDNode *Context) {
305 DIDescriptor D(Context);
306 if (D.isSubprogram())
309 return isSubprogramContext(resolve(DIType(Context).getContext()));
313 /// Check whether we should create a DIE for the given Scope, return true
314 /// if we don't create a DIE (the corresponding DIE is null).
315 bool DwarfDebug::isLexicalScopeDIENull(LexicalScope *Scope) {
316 if (Scope->isAbstractScope())
319 // We don't create a DIE if there is no Range.
320 const SmallVectorImpl<InsnRange> &Ranges = Scope->getRanges();
324 if (Ranges.size() > 1)
327 // We don't create a DIE if we have a single Range and the end label
329 return !getLabelAfterInsn(Ranges.front().second);
332 template <typename Func> void forBothCUs(DwarfCompileUnit &CU, Func F) {
334 if (auto *SkelCU = CU.getSkeleton())
338 void DwarfDebug::constructAbstractSubprogramScopeDIE(LexicalScope *Scope) {
339 assert(Scope && Scope->getScopeNode());
340 assert(Scope->isAbstractScope());
341 assert(!Scope->getInlinedAt());
343 const MDNode *SP = Scope->getScopeNode();
345 ProcessedSPNodes.insert(SP);
347 // Find the subprogram's DwarfCompileUnit in the SPMap in case the subprogram
348 // was inlined from another compile unit.
349 auto &CU = SPMap[SP];
350 forBothCUs(*CU, [&](DwarfCompileUnit &CU) {
351 CU.constructAbstractSubprogramScopeDIE(Scope);
355 void DwarfDebug::addGnuPubAttributes(DwarfUnit &U, DIE &D) const {
356 if (!GenerateGnuPubSections)
359 U.addFlag(D, dwarf::DW_AT_GNU_pubnames);
362 // Create new DwarfCompileUnit for the given metadata node with tag
363 // DW_TAG_compile_unit.
364 DwarfCompileUnit &DwarfDebug::constructDwarfCompileUnit(DICompileUnit DIUnit) {
365 StringRef FN = DIUnit.getFilename();
366 CompilationDir = DIUnit.getDirectory();
368 auto OwnedUnit = make_unique<DwarfCompileUnit>(
369 InfoHolder.getUnits().size(), DIUnit, Asm, this, &InfoHolder);
370 DwarfCompileUnit &NewCU = *OwnedUnit;
371 DIE &Die = NewCU.getUnitDie();
372 InfoHolder.addUnit(std::move(OwnedUnit));
374 NewCU.setSkeleton(constructSkeletonCU(NewCU));
376 // LTO with assembly output shares a single line table amongst multiple CUs.
377 // To avoid the compilation directory being ambiguous, let the line table
378 // explicitly describe the directory of all files, never relying on the
379 // compilation directory.
380 if (!Asm->OutStreamer.hasRawTextSupport() || SingleCU)
381 Asm->OutStreamer.getContext().setMCLineTableCompilationDir(
382 NewCU.getUniqueID(), CompilationDir);
384 NewCU.addString(Die, dwarf::DW_AT_producer, DIUnit.getProducer());
385 NewCU.addUInt(Die, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
386 DIUnit.getLanguage());
387 NewCU.addString(Die, dwarf::DW_AT_name, FN);
389 if (!useSplitDwarf()) {
390 NewCU.initStmtList();
392 // If we're using split dwarf the compilation dir is going to be in the
393 // skeleton CU and so we don't need to duplicate it here.
394 if (!CompilationDir.empty())
395 NewCU.addString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
397 addGnuPubAttributes(NewCU, Die);
400 if (DIUnit.isOptimized())
401 NewCU.addFlag(Die, dwarf::DW_AT_APPLE_optimized);
403 StringRef Flags = DIUnit.getFlags();
405 NewCU.addString(Die, dwarf::DW_AT_APPLE_flags, Flags);
407 if (unsigned RVer = DIUnit.getRunTimeVersion())
408 NewCU.addUInt(Die, dwarf::DW_AT_APPLE_major_runtime_vers,
409 dwarf::DW_FORM_data1, RVer);
412 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoDWOSection());
414 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoSection());
416 CUMap.insert(std::make_pair(DIUnit, &NewCU));
417 CUDieMap.insert(std::make_pair(&Die, &NewCU));
421 void DwarfDebug::constructAndAddImportedEntityDIE(DwarfCompileUnit &TheCU,
423 DIImportedEntity Module(N);
424 assert(Module.Verify());
425 if (DIE *D = TheCU.getOrCreateContextDIE(Module.getContext()))
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(N);
449 DwarfCompileUnit &CU = constructDwarfCompileUnit(CUNode);
450 DIArray ImportedEntities = CUNode.getImportedEntities();
451 for (unsigned i = 0, e = ImportedEntities.getNumElements(); i != e; ++i)
452 ScopesWithImportedEntities.push_back(std::make_pair(
453 DIImportedEntity(ImportedEntities.getElement(i)).getContext(),
454 ImportedEntities.getElement(i)));
455 // Stable sort to preserve the order of appearance of imported entities.
456 // This is to avoid out-of-order processing of interdependent declarations
457 // within the same scope, e.g. { namespace A = base; namespace B = A; }
458 std::stable_sort(ScopesWithImportedEntities.begin(),
459 ScopesWithImportedEntities.end(), less_first());
460 DIArray GVs = CUNode.getGlobalVariables();
461 for (unsigned i = 0, e = GVs.getNumElements(); i != e; ++i)
462 CU.getOrCreateGlobalVariableDIE(DIGlobalVariable(GVs.getElement(i)));
463 DIArray SPs = CUNode.getSubprograms();
464 for (unsigned i = 0, e = SPs.getNumElements(); i != e; ++i)
465 SPMap.insert(std::make_pair(SPs.getElement(i), &CU));
466 DIArray EnumTypes = CUNode.getEnumTypes();
467 for (unsigned i = 0, e = EnumTypes.getNumElements(); i != e; ++i) {
468 DIType Ty(EnumTypes.getElement(i));
469 // The enum types array by design contains pointers to
470 // MDNodes rather than DIRefs. Unique them here.
471 DIType UniqueTy(resolve(Ty.getRef()));
472 CU.getOrCreateTypeDIE(UniqueTy);
474 DIArray RetainedTypes = CUNode.getRetainedTypes();
475 for (unsigned i = 0, e = RetainedTypes.getNumElements(); i != e; ++i) {
476 DIType Ty(RetainedTypes.getElement(i));
477 // The retained types array by design contains pointers to
478 // MDNodes rather than DIRefs. Unique them here.
479 DIType UniqueTy(resolve(Ty.getRef()));
480 CU.getOrCreateTypeDIE(UniqueTy);
482 // Emit imported_modules last so that the relevant context is already
484 for (unsigned i = 0, e = ImportedEntities.getNumElements(); i != e; ++i)
485 constructAndAddImportedEntityDIE(CU, ImportedEntities.getElement(i));
488 // Tell MMI that we have debug info.
489 MMI->setDebugInfoAvailability(true);
492 void DwarfDebug::finishVariableDefinitions() {
493 for (const auto &Var : ConcreteVariables) {
494 DIE *VariableDie = Var->getDIE();
496 // FIXME: Consider the time-space tradeoff of just storing the unit pointer
497 // in the ConcreteVariables list, rather than looking it up again here.
498 // DIE::getUnit isn't simple - it walks parent pointers, etc.
499 DwarfCompileUnit *Unit = lookupUnit(VariableDie->getUnit());
501 DbgVariable *AbsVar = getExistingAbstractVariable(Var->getVariable());
502 if (AbsVar && AbsVar->getDIE()) {
503 Unit->addDIEEntry(*VariableDie, dwarf::DW_AT_abstract_origin,
506 Unit->applyVariableAttributes(*Var, *VariableDie);
510 void DwarfDebug::finishSubprogramDefinitions() {
511 for (const auto &P : SPMap)
512 forBothCUs(*P.second, [&](DwarfCompileUnit &CU) {
513 CU.finishSubprogramDefinition(DISubprogram(P.first));
518 // Collect info for variables that were optimized out.
519 void DwarfDebug::collectDeadVariables() {
520 const Module *M = MMI->getModule();
522 if (NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu")) {
523 for (MDNode *N : CU_Nodes->operands()) {
524 DICompileUnit TheCU(N);
525 // Construct subprogram DIE and add variables DIEs.
526 DwarfCompileUnit *SPCU =
527 static_cast<DwarfCompileUnit *>(CUMap.lookup(TheCU));
528 assert(SPCU && "Unable to find Compile Unit!");
529 DIArray Subprograms = TheCU.getSubprograms();
530 for (unsigned i = 0, e = Subprograms.getNumElements(); i != e; ++i) {
531 DISubprogram SP(Subprograms.getElement(i));
532 if (ProcessedSPNodes.count(SP) != 0)
534 SPCU->collectDeadVariables(SP);
540 void DwarfDebug::finalizeModuleInfo() {
541 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
543 finishSubprogramDefinitions();
545 finishVariableDefinitions();
547 // Collect info for variables that were optimized out.
548 collectDeadVariables();
550 // Handle anything that needs to be done on a per-unit basis after
551 // all other generation.
552 for (const auto &P : CUMap) {
553 auto &TheCU = *P.second;
554 // Emit DW_AT_containing_type attribute to connect types with their
555 // vtable holding type.
556 TheCU.constructContainingTypeDIEs();
558 // Add CU specific attributes if we need to add any.
559 // If we're splitting the dwarf out now that we've got the entire
560 // CU then add the dwo id to it.
561 auto *SkCU = TheCU.getSkeleton();
562 if (useSplitDwarf()) {
563 // Emit a unique identifier for this CU.
564 uint64_t ID = DIEHash(Asm).computeCUSignature(TheCU.getUnitDie());
565 TheCU.addUInt(TheCU.getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
566 dwarf::DW_FORM_data8, ID);
567 SkCU->addUInt(SkCU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
568 dwarf::DW_FORM_data8, ID);
570 // We don't keep track of which addresses are used in which CU so this
571 // is a bit pessimistic under LTO.
572 if (!AddrPool.isEmpty()) {
573 const MCSymbol *Sym = TLOF.getDwarfAddrSection()->getBeginSymbol();
574 SkCU->addSectionLabel(SkCU->getUnitDie(), dwarf::DW_AT_GNU_addr_base,
577 if (!SkCU->getRangeLists().empty()) {
578 const MCSymbol *Sym = TLOF.getDwarfRangesSection()->getBeginSymbol();
579 SkCU->addSectionLabel(SkCU->getUnitDie(), dwarf::DW_AT_GNU_ranges_base,
584 // If we have code split among multiple sections or non-contiguous
585 // ranges of code then emit a DW_AT_ranges attribute on the unit that will
586 // remain in the .o file, otherwise add a DW_AT_low_pc.
587 // FIXME: We should use ranges allow reordering of code ala
588 // .subsections_via_symbols in mach-o. This would mean turning on
589 // ranges for all subprogram DIEs for mach-o.
590 DwarfCompileUnit &U = SkCU ? *SkCU : TheCU;
591 if (unsigned NumRanges = TheCU.getRanges().size()) {
593 // A DW_AT_low_pc attribute may also be specified in combination with
594 // DW_AT_ranges to specify the default base address for use in
595 // location lists (see Section 2.6.2) and range lists (see Section
597 U.addUInt(U.getUnitDie(), dwarf::DW_AT_low_pc, dwarf::DW_FORM_addr, 0);
599 TheCU.setBaseAddress(TheCU.getRanges().front().getStart());
600 U.attachRangesOrLowHighPC(U.getUnitDie(), TheCU.takeRanges());
604 // Compute DIE offsets and sizes.
605 InfoHolder.computeSizeAndOffsets();
607 SkeletonHolder.computeSizeAndOffsets();
610 // Emit all Dwarf sections that should come after the content.
611 void DwarfDebug::endModule() {
612 assert(CurFn == nullptr);
613 assert(CurMI == nullptr);
615 // If we aren't actually generating debug info (check beginModule -
616 // conditionalized on !DisableDebugInfoPrinting and the presence of the
617 // llvm.dbg.cu metadata node)
618 if (!MMI->hasDebugInfo())
621 // Finalize the debug info for the module.
622 finalizeModuleInfo();
629 // Emit info into a debug loc section.
632 // Corresponding abbreviations into a abbrev section.
635 // Emit all the DIEs into a debug info section.
638 // Emit info into a debug aranges section.
639 if (GenerateARangeSection)
642 // Emit info into a debug ranges section.
645 if (useSplitDwarf()) {
648 emitDebugAbbrevDWO();
650 // Emit DWO addresses.
651 AddrPool.emit(*Asm, Asm->getObjFileLowering().getDwarfAddrSection());
654 // Emit info into the dwarf accelerator table sections.
655 if (useDwarfAccelTables()) {
658 emitAccelNamespaces();
662 // Emit the pubnames and pubtypes sections if requested.
663 if (HasDwarfPubSections) {
664 emitDebugPubNames(GenerateGnuPubSections);
665 emitDebugPubTypes(GenerateGnuPubSections);
670 AbstractVariables.clear();
673 // Find abstract variable, if any, associated with Var.
674 DbgVariable *DwarfDebug::getExistingAbstractVariable(const DIVariable &DV,
675 DIVariable &Cleansed) {
676 LLVMContext &Ctx = DV->getContext();
677 // More then one inlined variable corresponds to one abstract variable.
678 // FIXME: This duplication of variables when inlining should probably be
679 // removed. It's done to allow each DIVariable to describe its location
680 // because the DebugLoc on the dbg.value/declare isn't accurate. We should
681 // make it accurate then remove this duplication/cleansing stuff.
682 Cleansed = cleanseInlinedVariable(DV, Ctx);
683 auto I = AbstractVariables.find(Cleansed);
684 if (I != AbstractVariables.end())
685 return I->second.get();
689 DbgVariable *DwarfDebug::getExistingAbstractVariable(const DIVariable &DV) {
691 return getExistingAbstractVariable(DV, Cleansed);
694 void DwarfDebug::createAbstractVariable(const DIVariable &Var,
695 LexicalScope *Scope) {
696 auto AbsDbgVariable = make_unique<DbgVariable>(Var, DIExpression(), this);
697 InfoHolder.addScopeVariable(Scope, AbsDbgVariable.get());
698 AbstractVariables[Var] = std::move(AbsDbgVariable);
701 void DwarfDebug::ensureAbstractVariableIsCreated(const DIVariable &DV,
702 const MDNode *ScopeNode) {
703 DIVariable Cleansed = DV;
704 if (getExistingAbstractVariable(DV, Cleansed))
707 createAbstractVariable(Cleansed, LScopes.getOrCreateAbstractScope(
708 cast<MDLocalScope>(ScopeNode)));
712 DwarfDebug::ensureAbstractVariableIsCreatedIfScoped(const DIVariable &DV,
713 const MDNode *ScopeNode) {
714 DIVariable Cleansed = DV;
715 if (getExistingAbstractVariable(DV, Cleansed))
718 if (LexicalScope *Scope =
719 LScopes.findAbstractScope(cast_or_null<MDLocalScope>(ScopeNode)))
720 createAbstractVariable(Cleansed, Scope);
723 // Collect variable information from side table maintained by MMI.
724 void DwarfDebug::collectVariableInfoFromMMITable(
725 SmallPtrSetImpl<const MDNode *> &Processed) {
726 for (const auto &VI : MMI->getVariableDbgInfo()) {
729 Processed.insert(VI.Var);
730 LexicalScope *Scope = LScopes.findLexicalScope(VI.Loc);
732 // If variable scope is not found then skip this variable.
736 DIVariable DV(VI.Var);
737 assert(DV->isValidLocationForIntrinsic(VI.Loc) &&
738 "Expected inlined-at fields to agree");
739 DIExpression Expr(VI.Expr);
740 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
741 auto RegVar = make_unique<DbgVariable>(DV, Expr, this, VI.Slot);
742 if (InfoHolder.addScopeVariable(Scope, RegVar.get()))
743 ConcreteVariables.push_back(std::move(RegVar));
747 // Get .debug_loc entry for the instruction range starting at MI.
748 static DebugLocEntry::Value getDebugLocValue(const MachineInstr *MI) {
749 const MDNode *Expr = MI->getDebugExpression();
750 const MDNode *Var = MI->getDebugVariable();
752 assert(MI->getNumOperands() == 4);
753 if (MI->getOperand(0).isReg()) {
754 MachineLocation MLoc;
755 // If the second operand is an immediate, this is a
756 // register-indirect address.
757 if (!MI->getOperand(1).isImm())
758 MLoc.set(MI->getOperand(0).getReg());
760 MLoc.set(MI->getOperand(0).getReg(), MI->getOperand(1).getImm());
761 return DebugLocEntry::Value(Var, Expr, MLoc);
763 if (MI->getOperand(0).isImm())
764 return DebugLocEntry::Value(Var, Expr, MI->getOperand(0).getImm());
765 if (MI->getOperand(0).isFPImm())
766 return DebugLocEntry::Value(Var, Expr, MI->getOperand(0).getFPImm());
767 if (MI->getOperand(0).isCImm())
768 return DebugLocEntry::Value(Var, Expr, MI->getOperand(0).getCImm());
770 llvm_unreachable("Unexpected 4-operand DBG_VALUE instruction!");
773 /// Determine whether two variable pieces overlap.
774 static bool piecesOverlap(DIExpression P1, DIExpression P2) {
775 if (!P1.isBitPiece() || !P2.isBitPiece())
777 unsigned l1 = P1.getBitPieceOffset();
778 unsigned l2 = P2.getBitPieceOffset();
779 unsigned r1 = l1 + P1.getBitPieceSize();
780 unsigned r2 = l2 + P2.getBitPieceSize();
781 // True where [l1,r1[ and [r1,r2[ overlap.
782 return (l1 < r2) && (l2 < r1);
785 /// Build the location list for all DBG_VALUEs in the function that
786 /// describe the same variable. If the ranges of several independent
787 /// pieces of the same variable overlap partially, split them up and
788 /// combine the ranges. The resulting DebugLocEntries are will have
789 /// strict monotonically increasing begin addresses and will never
794 // Ranges History [var, loc, piece ofs size]
795 // 0 | [x, (reg0, piece 0, 32)]
796 // 1 | | [x, (reg1, piece 32, 32)] <- IsPieceOfPrevEntry
798 // 3 | [clobber reg0]
799 // 4 [x, (mem, piece 0, 64)] <- overlapping with both previous pieces of
804 // [0-1] [x, (reg0, piece 0, 32)]
805 // [1-3] [x, (reg0, piece 0, 32), (reg1, piece 32, 32)]
806 // [3-4] [x, (reg1, piece 32, 32)]
807 // [4- ] [x, (mem, piece 0, 64)]
809 DwarfDebug::buildLocationList(SmallVectorImpl<DebugLocEntry> &DebugLoc,
810 const DbgValueHistoryMap::InstrRanges &Ranges) {
811 SmallVector<DebugLocEntry::Value, 4> OpenRanges;
813 for (auto I = Ranges.begin(), E = Ranges.end(); I != E; ++I) {
814 const MachineInstr *Begin = I->first;
815 const MachineInstr *End = I->second;
816 assert(Begin->isDebugValue() && "Invalid History entry");
818 // Check if a variable is inaccessible in this range.
819 if (Begin->getNumOperands() > 1 &&
820 Begin->getOperand(0).isReg() && !Begin->getOperand(0).getReg()) {
825 // If this piece overlaps with any open ranges, truncate them.
826 DIExpression DIExpr = Begin->getDebugExpression();
827 auto Last = std::remove_if(OpenRanges.begin(), OpenRanges.end(),
828 [&](DebugLocEntry::Value R) {
829 return piecesOverlap(DIExpr, R.getExpression());
831 OpenRanges.erase(Last, OpenRanges.end());
833 const MCSymbol *StartLabel = getLabelBeforeInsn(Begin);
834 assert(StartLabel && "Forgot label before DBG_VALUE starting a range!");
836 const MCSymbol *EndLabel;
838 EndLabel = getLabelAfterInsn(End);
839 else if (std::next(I) == Ranges.end())
840 EndLabel = Asm->getFunctionEnd();
842 EndLabel = getLabelBeforeInsn(std::next(I)->first);
843 assert(EndLabel && "Forgot label after instruction ending a range!");
845 DEBUG(dbgs() << "DotDebugLoc: " << *Begin << "\n");
847 auto Value = getDebugLocValue(Begin);
848 DebugLocEntry Loc(StartLabel, EndLabel, Value);
849 bool couldMerge = false;
851 // If this is a piece, it may belong to the current DebugLocEntry.
852 if (DIExpr.isBitPiece()) {
853 // Add this value to the list of open ranges.
854 OpenRanges.push_back(Value);
856 // Attempt to add the piece to the last entry.
857 if (!DebugLoc.empty())
858 if (DebugLoc.back().MergeValues(Loc))
863 // Need to add a new DebugLocEntry. Add all values from still
864 // valid non-overlapping pieces.
865 if (OpenRanges.size())
866 Loc.addValues(OpenRanges);
868 DebugLoc.push_back(std::move(Loc));
871 // Attempt to coalesce the ranges of two otherwise identical
873 auto CurEntry = DebugLoc.rbegin();
874 auto PrevEntry = std::next(CurEntry);
875 if (PrevEntry != DebugLoc.rend() && PrevEntry->MergeRanges(*CurEntry))
879 dbgs() << CurEntry->getValues().size() << " Values:\n";
880 for (auto Value : CurEntry->getValues()) {
881 Value.getVariable()->dump();
882 Value.getExpression()->dump();
890 // Find variables for each lexical scope.
892 DwarfDebug::collectVariableInfo(DwarfCompileUnit &TheCU, DISubprogram SP,
893 SmallPtrSetImpl<const MDNode *> &Processed) {
894 // Grab the variable info that was squirreled away in the MMI side-table.
895 collectVariableInfoFromMMITable(Processed);
897 for (const auto &I : DbgValues) {
898 DIVariable DV(I.first);
899 if (Processed.count(DV))
902 // Instruction ranges, specifying where DV is accessible.
903 const auto &Ranges = I.second;
907 LexicalScope *Scope = nullptr;
908 if (MDLocation *IA = DV.get()->getInlinedAt())
909 Scope = LScopes.findInlinedScope(DV.get()->getScope(), IA);
911 Scope = LScopes.findLexicalScope(DV.get()->getScope());
912 // If variable scope is not found then skip this variable.
916 Processed.insert(DV);
917 const MachineInstr *MInsn = Ranges.front().first;
918 assert(MInsn->isDebugValue() && "History must begin with debug value");
919 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
920 ConcreteVariables.push_back(make_unique<DbgVariable>(MInsn, this));
921 DbgVariable *RegVar = ConcreteVariables.back().get();
922 InfoHolder.addScopeVariable(Scope, RegVar);
924 // Check if the first DBG_VALUE is valid for the rest of the function.
925 if (Ranges.size() == 1 && Ranges.front().second == nullptr)
928 // Handle multiple DBG_VALUE instructions describing one variable.
929 RegVar->setDotDebugLocOffset(DotDebugLocEntries.size());
931 DotDebugLocEntries.resize(DotDebugLocEntries.size() + 1);
932 DebugLocList &LocList = DotDebugLocEntries.back();
934 LocList.Label = Asm->createTempSymbol("debug_loc");
936 // Build the location list for this variable.
937 buildLocationList(LocList.List, Ranges);
938 // Finalize the entry by lowering it into a DWARF bytestream.
939 for (auto &Entry : LocList.List)
940 Entry.finalize(*Asm, TypeIdentifierMap);
943 // Collect info for variables that were optimized out.
944 DIArray Variables = SP.getVariables();
945 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
946 DIVariable DV(Variables.getElement(i));
947 assert(DV.isVariable());
948 if (!Processed.insert(DV).second)
950 if (LexicalScope *Scope = LScopes.findLexicalScope(DV.get()->getScope())) {
951 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
953 ConcreteVariables.push_back(make_unique<DbgVariable>(DV, NoExpr, this));
954 InfoHolder.addScopeVariable(Scope, ConcreteVariables.back().get());
959 // Return Label preceding the instruction.
960 MCSymbol *DwarfDebug::getLabelBeforeInsn(const MachineInstr *MI) {
961 MCSymbol *Label = LabelsBeforeInsn.lookup(MI);
962 assert(Label && "Didn't insert label before instruction");
966 // Return Label immediately following the instruction.
967 MCSymbol *DwarfDebug::getLabelAfterInsn(const MachineInstr *MI) {
968 return LabelsAfterInsn.lookup(MI);
971 // Process beginning of an instruction.
972 void DwarfDebug::beginInstruction(const MachineInstr *MI) {
973 assert(CurMI == nullptr);
975 // Check if source location changes, but ignore DBG_VALUE locations.
976 if (!MI->isDebugValue()) {
977 DebugLoc DL = MI->getDebugLoc();
978 if (DL != PrevInstLoc) {
982 if (DL == PrologEndLoc) {
983 Flags |= DWARF2_FLAG_PROLOGUE_END;
984 PrologEndLoc = DebugLoc();
985 Flags |= DWARF2_FLAG_IS_STMT;
988 Asm->OutStreamer.getContext().getCurrentDwarfLoc().getLine())
989 Flags |= DWARF2_FLAG_IS_STMT;
991 const MDNode *Scope = DL.getScope();
992 recordSourceLine(DL.getLine(), DL.getCol(), Scope, Flags);
993 } else if (UnknownLocations) {
995 recordSourceLine(0, 0, nullptr, 0);
1000 // Insert labels where requested.
1001 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1002 LabelsBeforeInsn.find(MI);
1005 if (I == LabelsBeforeInsn.end())
1008 // Label already assigned.
1013 PrevLabel = MMI->getContext().CreateTempSymbol();
1014 Asm->OutStreamer.EmitLabel(PrevLabel);
1016 I->second = PrevLabel;
1019 // Process end of an instruction.
1020 void DwarfDebug::endInstruction() {
1021 assert(CurMI != nullptr);
1022 // Don't create a new label after DBG_VALUE instructions.
1023 // They don't generate code.
1024 if (!CurMI->isDebugValue())
1025 PrevLabel = nullptr;
1027 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1028 LabelsAfterInsn.find(CurMI);
1032 if (I == LabelsAfterInsn.end())
1035 // Label already assigned.
1039 // We need a label after this instruction.
1041 PrevLabel = MMI->getContext().CreateTempSymbol();
1042 Asm->OutStreamer.EmitLabel(PrevLabel);
1044 I->second = PrevLabel;
1047 // Each LexicalScope has first instruction and last instruction to mark
1048 // beginning and end of a scope respectively. Create an inverse map that list
1049 // scopes starts (and ends) with an instruction. One instruction may start (or
1050 // end) multiple scopes. Ignore scopes that are not reachable.
1051 void DwarfDebug::identifyScopeMarkers() {
1052 SmallVector<LexicalScope *, 4> WorkList;
1053 WorkList.push_back(LScopes.getCurrentFunctionScope());
1054 while (!WorkList.empty()) {
1055 LexicalScope *S = WorkList.pop_back_val();
1057 const SmallVectorImpl<LexicalScope *> &Children = S->getChildren();
1058 if (!Children.empty())
1059 WorkList.append(Children.begin(), Children.end());
1061 if (S->isAbstractScope())
1064 for (const InsnRange &R : S->getRanges()) {
1065 assert(R.first && "InsnRange does not have first instruction!");
1066 assert(R.second && "InsnRange does not have second instruction!");
1067 requestLabelBeforeInsn(R.first);
1068 requestLabelAfterInsn(R.second);
1073 static DebugLoc findPrologueEndLoc(const MachineFunction *MF) {
1074 // First known non-DBG_VALUE and non-frame setup location marks
1075 // the beginning of the function body.
1076 for (const auto &MBB : *MF)
1077 for (const auto &MI : MBB)
1078 if (!MI.isDebugValue() && !MI.getFlag(MachineInstr::FrameSetup) &&
1080 // Did the target forget to set the FrameSetup flag for CFI insns?
1081 assert(!MI.isCFIInstruction() &&
1082 "First non-frame-setup instruction is a CFI instruction.");
1083 return MI.getDebugLoc();
1088 // Gather pre-function debug information. Assumes being called immediately
1089 // after the function entry point has been emitted.
1090 void DwarfDebug::beginFunction(const MachineFunction *MF) {
1093 // If there's no debug info for the function we're not going to do anything.
1094 if (!MMI->hasDebugInfo())
1097 auto DI = FunctionDIs.find(MF->getFunction());
1098 if (DI == FunctionDIs.end())
1101 // Grab the lexical scopes for the function, if we don't have any of those
1102 // then we're not going to be able to do anything.
1103 LScopes.initialize(*MF);
1104 if (LScopes.empty())
1107 assert(DbgValues.empty() && "DbgValues map wasn't cleaned!");
1109 // Make sure that each lexical scope will have a begin/end label.
1110 identifyScopeMarkers();
1112 // Set DwarfDwarfCompileUnitID in MCContext to the Compile Unit this function
1113 // belongs to so that we add to the correct per-cu line table in the
1115 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1116 // FnScope->getScopeNode() and DI->second should represent the same function,
1117 // though they may not be the same MDNode due to inline functions merged in
1118 // LTO where the debug info metadata still differs (either due to distinct
1119 // written differences - two versions of a linkonce_odr function
1120 // written/copied into two separate files, or some sub-optimal metadata that
1121 // isn't structurally identical (see: file path/name info from clang, which
1122 // includes the directory of the cpp file being built, even when the file name
1123 // is absolute (such as an <> lookup header)))
1124 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1125 assert(TheCU && "Unable to find compile unit!");
1126 if (Asm->OutStreamer.hasRawTextSupport())
1127 // Use a single line table if we are generating assembly.
1128 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1130 Asm->OutStreamer.getContext().setDwarfCompileUnitID(TheCU->getUniqueID());
1132 // Calculate history for local variables.
1133 calculateDbgValueHistory(MF, Asm->MF->getSubtarget().getRegisterInfo(),
1136 // Request labels for the full history.
1137 for (const auto &I : DbgValues) {
1138 const auto &Ranges = I.second;
1142 // The first mention of a function argument gets the CurrentFnBegin
1143 // label, so arguments are visible when breaking at function entry.
1144 DIVariable DIVar(Ranges.front().first->getDebugVariable());
1145 if (DIVar.isVariable() && DIVar.getTag() == dwarf::DW_TAG_arg_variable &&
1146 getDISubprogram(DIVar.getContext()).describes(MF->getFunction())) {
1147 LabelsBeforeInsn[Ranges.front().first] = Asm->getFunctionBegin();
1148 if (Ranges.front().first->getDebugExpression().isBitPiece()) {
1149 // Mark all non-overlapping initial pieces.
1150 for (auto I = Ranges.begin(); I != Ranges.end(); ++I) {
1151 DIExpression Piece = I->first->getDebugExpression();
1152 if (std::all_of(Ranges.begin(), I,
1153 [&](DbgValueHistoryMap::InstrRange Pred) {
1154 return !piecesOverlap(Piece, Pred.first->getDebugExpression());
1156 LabelsBeforeInsn[I->first] = Asm->getFunctionBegin();
1163 for (const auto &Range : Ranges) {
1164 requestLabelBeforeInsn(Range.first);
1166 requestLabelAfterInsn(Range.second);
1170 PrevInstLoc = DebugLoc();
1171 PrevLabel = Asm->getFunctionBegin();
1173 // Record beginning of function.
1174 PrologEndLoc = findPrologueEndLoc(MF);
1175 if (MDLocation *L = PrologEndLoc) {
1176 // We'd like to list the prologue as "not statements" but GDB behaves
1177 // poorly if we do that. Revisit this with caution/GDB (7.5+) testing.
1178 auto *SP = L->getInlinedAtScope()->getSubprogram();
1179 recordSourceLine(SP->getScopeLine(), 0, SP, DWARF2_FLAG_IS_STMT);
1183 // Gather and emit post-function debug information.
1184 void DwarfDebug::endFunction(const MachineFunction *MF) {
1185 assert(CurFn == MF &&
1186 "endFunction should be called with the same function as beginFunction");
1188 if (!MMI->hasDebugInfo() || LScopes.empty() ||
1189 !FunctionDIs.count(MF->getFunction())) {
1190 // If we don't have a lexical scope for this function then there will
1191 // be a hole in the range information. Keep note of this by setting the
1192 // previously used section to nullptr.
1198 // Set DwarfDwarfCompileUnitID in MCContext to default value.
1199 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1201 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1202 DISubprogram SP(FnScope->getScopeNode());
1203 DwarfCompileUnit &TheCU = *SPMap.lookup(SP);
1205 SmallPtrSet<const MDNode *, 16> ProcessedVars;
1206 collectVariableInfo(TheCU, SP, ProcessedVars);
1208 // Add the range of this function to the list of ranges for the CU.
1209 TheCU.addRange(RangeSpan(Asm->getFunctionBegin(), Asm->getFunctionEnd()));
1211 // Under -gmlt, skip building the subprogram if there are no inlined
1212 // subroutines inside it.
1213 if (TheCU.getCUNode().getEmissionKind() == DIBuilder::LineTablesOnly &&
1214 LScopes.getAbstractScopesList().empty() && !IsDarwin) {
1215 assert(InfoHolder.getScopeVariables().empty());
1216 assert(DbgValues.empty());
1217 // FIXME: This wouldn't be true in LTO with a -g (with inlining) CU followed
1218 // by a -gmlt CU. Add a test and remove this assertion.
1219 assert(AbstractVariables.empty());
1220 LabelsBeforeInsn.clear();
1221 LabelsAfterInsn.clear();
1222 PrevLabel = nullptr;
1228 size_t NumAbstractScopes = LScopes.getAbstractScopesList().size();
1230 // Construct abstract scopes.
1231 for (LexicalScope *AScope : LScopes.getAbstractScopesList()) {
1232 DISubprogram SP(AScope->getScopeNode());
1233 assert(SP.isSubprogram());
1234 // Collect info for variables that were optimized out.
1235 DIArray Variables = SP.getVariables();
1236 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1237 DIVariable DV(Variables.getElement(i));
1238 assert(DV && DV.isVariable());
1239 if (!ProcessedVars.insert(DV).second)
1241 ensureAbstractVariableIsCreated(DV, DV.getContext());
1242 assert(LScopes.getAbstractScopesList().size() == NumAbstractScopes
1243 && "ensureAbstractVariableIsCreated inserted abstract scopes");
1245 constructAbstractSubprogramScopeDIE(AScope);
1248 TheCU.constructSubprogramScopeDIE(FnScope);
1249 if (auto *SkelCU = TheCU.getSkeleton())
1250 if (!LScopes.getAbstractScopesList().empty())
1251 SkelCU->constructSubprogramScopeDIE(FnScope);
1254 // Ownership of DbgVariables is a bit subtle - ScopeVariables owns all the
1255 // DbgVariables except those that are also in AbstractVariables (since they
1256 // can be used cross-function)
1257 InfoHolder.getScopeVariables().clear();
1259 LabelsBeforeInsn.clear();
1260 LabelsAfterInsn.clear();
1261 PrevLabel = nullptr;
1265 // Register a source line with debug info. Returns the unique label that was
1266 // emitted and which provides correspondence to the source line list.
1267 void DwarfDebug::recordSourceLine(unsigned Line, unsigned Col, const MDNode *S,
1272 unsigned Discriminator = 0;
1273 if (DIScope Scope = DIScope(S)) {
1274 assert(Scope.isScope());
1275 Fn = Scope.getFilename();
1276 Dir = Scope.getDirectory();
1277 if (Scope.isLexicalBlockFile())
1278 Discriminator = DILexicalBlockFile(S).getDiscriminator();
1280 unsigned CUID = Asm->OutStreamer.getContext().getDwarfCompileUnitID();
1281 Src = static_cast<DwarfCompileUnit &>(*InfoHolder.getUnits()[CUID])
1282 .getOrCreateSourceID(Fn, Dir);
1284 Asm->OutStreamer.EmitDwarfLocDirective(Src, Line, Col, Flags, 0,
1288 //===----------------------------------------------------------------------===//
1290 //===----------------------------------------------------------------------===//
1292 // Emit the debug info section.
1293 void DwarfDebug::emitDebugInfo() {
1294 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1295 Holder.emitUnits(/* UseOffsets */ false);
1298 // Emit the abbreviation section.
1299 void DwarfDebug::emitAbbreviations() {
1300 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1302 Holder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevSection());
1305 void DwarfDebug::emitAccel(DwarfAccelTable &Accel, const MCSection *Section,
1306 StringRef TableName) {
1307 Accel.FinalizeTable(Asm, TableName);
1308 Asm->OutStreamer.SwitchSection(Section);
1310 // Emit the full data.
1311 Accel.emit(Asm, Section->getBeginSymbol(), this);
1314 // Emit visible names into a hashed accelerator table section.
1315 void DwarfDebug::emitAccelNames() {
1316 emitAccel(AccelNames, Asm->getObjFileLowering().getDwarfAccelNamesSection(),
1320 // Emit objective C classes and categories into a hashed accelerator table
1322 void DwarfDebug::emitAccelObjC() {
1323 emitAccel(AccelObjC, Asm->getObjFileLowering().getDwarfAccelObjCSection(),
1327 // Emit namespace dies into a hashed accelerator table.
1328 void DwarfDebug::emitAccelNamespaces() {
1329 emitAccel(AccelNamespace,
1330 Asm->getObjFileLowering().getDwarfAccelNamespaceSection(),
1334 // Emit type dies into a hashed accelerator table.
1335 void DwarfDebug::emitAccelTypes() {
1336 emitAccel(AccelTypes, Asm->getObjFileLowering().getDwarfAccelTypesSection(),
1340 // Public name handling.
1341 // The format for the various pubnames:
1343 // dwarf pubnames - offset/name pairs where the offset is the offset into the CU
1344 // for the DIE that is named.
1346 // gnu pubnames - offset/index value/name tuples where the offset is the offset
1347 // into the CU and the index value is computed according to the type of value
1348 // for the DIE that is named.
1350 // For type units the offset is the offset of the skeleton DIE. For split dwarf
1351 // it's the offset within the debug_info/debug_types dwo section, however, the
1352 // reference in the pubname header doesn't change.
1354 /// computeIndexValue - Compute the gdb index value for the DIE and CU.
1355 static dwarf::PubIndexEntryDescriptor computeIndexValue(DwarfUnit *CU,
1357 dwarf::GDBIndexEntryLinkage Linkage = dwarf::GIEL_STATIC;
1359 // We could have a specification DIE that has our most of our knowledge,
1360 // look for that now.
1361 DIEValue *SpecVal = Die->findAttribute(dwarf::DW_AT_specification);
1363 DIE &SpecDIE = cast<DIEEntry>(SpecVal)->getEntry();
1364 if (SpecDIE.findAttribute(dwarf::DW_AT_external))
1365 Linkage = dwarf::GIEL_EXTERNAL;
1366 } else if (Die->findAttribute(dwarf::DW_AT_external))
1367 Linkage = dwarf::GIEL_EXTERNAL;
1369 switch (Die->getTag()) {
1370 case dwarf::DW_TAG_class_type:
1371 case dwarf::DW_TAG_structure_type:
1372 case dwarf::DW_TAG_union_type:
1373 case dwarf::DW_TAG_enumeration_type:
1374 return dwarf::PubIndexEntryDescriptor(
1375 dwarf::GIEK_TYPE, CU->getLanguage() != dwarf::DW_LANG_C_plus_plus
1376 ? dwarf::GIEL_STATIC
1377 : dwarf::GIEL_EXTERNAL);
1378 case dwarf::DW_TAG_typedef:
1379 case dwarf::DW_TAG_base_type:
1380 case dwarf::DW_TAG_subrange_type:
1381 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_TYPE, dwarf::GIEL_STATIC);
1382 case dwarf::DW_TAG_namespace:
1383 return dwarf::GIEK_TYPE;
1384 case dwarf::DW_TAG_subprogram:
1385 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_FUNCTION, Linkage);
1386 case dwarf::DW_TAG_variable:
1387 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE, Linkage);
1388 case dwarf::DW_TAG_enumerator:
1389 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE,
1390 dwarf::GIEL_STATIC);
1392 return dwarf::GIEK_NONE;
1396 /// emitDebugPubNames - Emit visible names into a debug pubnames section.
1398 void DwarfDebug::emitDebugPubNames(bool GnuStyle) {
1399 const MCSection *PSec =
1400 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubNamesSection()
1401 : Asm->getObjFileLowering().getDwarfPubNamesSection();
1403 emitDebugPubSection(GnuStyle, PSec, "Names",
1404 &DwarfCompileUnit::getGlobalNames);
1407 void DwarfDebug::emitDebugPubSection(
1408 bool GnuStyle, const MCSection *PSec, StringRef Name,
1409 const StringMap<const DIE *> &(DwarfCompileUnit::*Accessor)() const) {
1410 for (const auto &NU : CUMap) {
1411 DwarfCompileUnit *TheU = NU.second;
1413 const auto &Globals = (TheU->*Accessor)();
1415 if (Globals.empty())
1418 if (auto *Skeleton = TheU->getSkeleton())
1421 // Start the dwarf pubnames section.
1422 Asm->OutStreamer.SwitchSection(PSec);
1425 Asm->OutStreamer.AddComment("Length of Public " + Name + " Info");
1426 MCSymbol *BeginLabel = Asm->createTempSymbol("pub" + Name + "_begin");
1427 MCSymbol *EndLabel = Asm->createTempSymbol("pub" + Name + "_end");
1428 Asm->EmitLabelDifference(EndLabel, BeginLabel, 4);
1430 Asm->OutStreamer.EmitLabel(BeginLabel);
1432 Asm->OutStreamer.AddComment("DWARF Version");
1433 Asm->EmitInt16(dwarf::DW_PUBNAMES_VERSION);
1435 Asm->OutStreamer.AddComment("Offset of Compilation Unit Info");
1436 Asm->emitSectionOffset(TheU->getLabelBegin());
1438 Asm->OutStreamer.AddComment("Compilation Unit Length");
1439 Asm->EmitInt32(TheU->getLength());
1441 // Emit the pubnames for this compilation unit.
1442 for (const auto &GI : Globals) {
1443 const char *Name = GI.getKeyData();
1444 const DIE *Entity = GI.second;
1446 Asm->OutStreamer.AddComment("DIE offset");
1447 Asm->EmitInt32(Entity->getOffset());
1450 dwarf::PubIndexEntryDescriptor Desc = computeIndexValue(TheU, Entity);
1451 Asm->OutStreamer.AddComment(
1452 Twine("Kind: ") + dwarf::GDBIndexEntryKindString(Desc.Kind) + ", " +
1453 dwarf::GDBIndexEntryLinkageString(Desc.Linkage));
1454 Asm->EmitInt8(Desc.toBits());
1457 Asm->OutStreamer.AddComment("External Name");
1458 Asm->OutStreamer.EmitBytes(StringRef(Name, GI.getKeyLength() + 1));
1461 Asm->OutStreamer.AddComment("End Mark");
1463 Asm->OutStreamer.EmitLabel(EndLabel);
1467 void DwarfDebug::emitDebugPubTypes(bool GnuStyle) {
1468 const MCSection *PSec =
1469 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubTypesSection()
1470 : Asm->getObjFileLowering().getDwarfPubTypesSection();
1472 emitDebugPubSection(GnuStyle, PSec, "Types",
1473 &DwarfCompileUnit::getGlobalTypes);
1476 // Emit visible names into a debug str section.
1477 void DwarfDebug::emitDebugStr() {
1478 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1479 Holder.emitStrings(Asm->getObjFileLowering().getDwarfStrSection());
1483 void DwarfDebug::emitDebugLocEntry(ByteStreamer &Streamer,
1484 const DebugLocEntry &Entry) {
1485 auto Comment = Entry.getComments().begin();
1486 auto End = Entry.getComments().end();
1487 for (uint8_t Byte : Entry.getDWARFBytes())
1488 Streamer.EmitInt8(Byte, Comment != End ? *(Comment++) : "");
1491 static void emitDebugLocValue(const AsmPrinter &AP,
1492 const DITypeIdentifierMap &TypeIdentifierMap,
1493 ByteStreamer &Streamer,
1494 const DebugLocEntry::Value &Value,
1495 unsigned PieceOffsetInBits) {
1496 DIVariable DV = Value.getVariable();
1497 DebugLocDwarfExpression DwarfExpr(*AP.MF->getSubtarget().getRegisterInfo(),
1498 AP.getDwarfDebug()->getDwarfVersion(),
1501 if (Value.isInt()) {
1502 DIBasicType BTy(DV.getType().resolve(TypeIdentifierMap));
1503 if (BTy.Verify() && (BTy.getEncoding() == dwarf::DW_ATE_signed ||
1504 BTy.getEncoding() == dwarf::DW_ATE_signed_char))
1505 DwarfExpr.AddSignedConstant(Value.getInt());
1507 DwarfExpr.AddUnsignedConstant(Value.getInt());
1508 } else if (Value.isLocation()) {
1509 MachineLocation Loc = Value.getLoc();
1510 DIExpression Expr = Value.getExpression();
1511 if (!Expr || (Expr.getNumElements() == 0))
1513 AP.EmitDwarfRegOp(Streamer, Loc);
1515 // Complex address entry.
1516 if (Loc.getOffset()) {
1517 DwarfExpr.AddMachineRegIndirect(Loc.getReg(), Loc.getOffset());
1518 DwarfExpr.AddExpression(Expr.begin(), Expr.end(), PieceOffsetInBits);
1520 DwarfExpr.AddMachineRegExpression(Expr, Loc.getReg(),
1524 // else ... ignore constant fp. There is not any good way to
1525 // to represent them here in dwarf.
1530 void DebugLocEntry::finalize(const AsmPrinter &AP,
1531 const DITypeIdentifierMap &TypeIdentifierMap) {
1532 BufferByteStreamer Streamer(DWARFBytes, Comments);
1533 const DebugLocEntry::Value Value = Values[0];
1534 if (Value.isBitPiece()) {
1535 // Emit all pieces that belong to the same variable and range.
1536 assert(std::all_of(Values.begin(), Values.end(), [](DebugLocEntry::Value P) {
1537 return P.isBitPiece();
1538 }) && "all values are expected to be pieces");
1539 assert(std::is_sorted(Values.begin(), Values.end()) &&
1540 "pieces are expected to be sorted");
1542 unsigned Offset = 0;
1543 for (auto Piece : Values) {
1544 DIExpression Expr = Piece.getExpression();
1545 unsigned PieceOffset = Expr.getBitPieceOffset();
1546 unsigned PieceSize = Expr.getBitPieceSize();
1547 assert(Offset <= PieceOffset && "overlapping or duplicate pieces");
1548 if (Offset < PieceOffset) {
1549 // The DWARF spec seriously mandates pieces with no locations for gaps.
1550 DebugLocDwarfExpression Expr(*AP.MF->getSubtarget().getRegisterInfo(),
1551 AP.getDwarfDebug()->getDwarfVersion(),
1553 Expr.AddOpPiece(PieceOffset-Offset, 0);
1554 Offset += PieceOffset-Offset;
1556 Offset += PieceSize;
1559 DIVariable Var = Piece.getVariable();
1560 unsigned VarSize = Var.getSizeInBits(TypeIdentifierMap);
1561 assert(PieceSize+PieceOffset <= VarSize
1562 && "piece is larger than or outside of variable");
1563 assert(PieceSize != VarSize
1564 && "piece covers entire variable");
1566 emitDebugLocValue(AP, TypeIdentifierMap, Streamer, Piece, PieceOffset);
1569 assert(Values.size() == 1 && "only pieces may have >1 value");
1570 emitDebugLocValue(AP, TypeIdentifierMap, Streamer, Value, 0);
1575 void DwarfDebug::emitDebugLocEntryLocation(const DebugLocEntry &Entry) {
1576 Asm->OutStreamer.AddComment("Loc expr size");
1577 MCSymbol *begin = Asm->OutStreamer.getContext().CreateTempSymbol();
1578 MCSymbol *end = Asm->OutStreamer.getContext().CreateTempSymbol();
1579 Asm->EmitLabelDifference(end, begin, 2);
1580 Asm->OutStreamer.EmitLabel(begin);
1582 APByteStreamer Streamer(*Asm);
1583 emitDebugLocEntry(Streamer, Entry);
1585 Asm->OutStreamer.EmitLabel(end);
1588 // Emit locations into the debug loc section.
1589 void DwarfDebug::emitDebugLoc() {
1590 // Start the dwarf loc section.
1591 Asm->OutStreamer.SwitchSection(
1592 Asm->getObjFileLowering().getDwarfLocSection());
1593 unsigned char Size = Asm->getDataLayout().getPointerSize();
1594 for (const auto &DebugLoc : DotDebugLocEntries) {
1595 Asm->OutStreamer.EmitLabel(DebugLoc.Label);
1596 const DwarfCompileUnit *CU = DebugLoc.CU;
1597 for (const auto &Entry : DebugLoc.List) {
1598 // Set up the range. This range is relative to the entry point of the
1599 // compile unit. This is a hard coded 0 for low_pc when we're emitting
1600 // ranges, or the DW_AT_low_pc on the compile unit otherwise.
1601 if (auto *Base = CU->getBaseAddress()) {
1602 Asm->EmitLabelDifference(Entry.getBeginSym(), Base, Size);
1603 Asm->EmitLabelDifference(Entry.getEndSym(), Base, Size);
1605 Asm->OutStreamer.EmitSymbolValue(Entry.getBeginSym(), Size);
1606 Asm->OutStreamer.EmitSymbolValue(Entry.getEndSym(), Size);
1609 emitDebugLocEntryLocation(Entry);
1611 Asm->OutStreamer.EmitIntValue(0, Size);
1612 Asm->OutStreamer.EmitIntValue(0, Size);
1616 void DwarfDebug::emitDebugLocDWO() {
1617 Asm->OutStreamer.SwitchSection(
1618 Asm->getObjFileLowering().getDwarfLocDWOSection());
1619 for (const auto &DebugLoc : DotDebugLocEntries) {
1620 Asm->OutStreamer.EmitLabel(DebugLoc.Label);
1621 for (const auto &Entry : DebugLoc.List) {
1622 // Just always use start_length for now - at least that's one address
1623 // rather than two. We could get fancier and try to, say, reuse an
1624 // address we know we've emitted elsewhere (the start of the function?
1625 // The start of the CU or CU subrange that encloses this range?)
1626 Asm->EmitInt8(dwarf::DW_LLE_start_length_entry);
1627 unsigned idx = AddrPool.getIndex(Entry.getBeginSym());
1628 Asm->EmitULEB128(idx);
1629 Asm->EmitLabelDifference(Entry.getEndSym(), Entry.getBeginSym(), 4);
1631 emitDebugLocEntryLocation(Entry);
1633 Asm->EmitInt8(dwarf::DW_LLE_end_of_list_entry);
1638 const MCSymbol *Start, *End;
1641 // Emit a debug aranges section, containing a CU lookup for any
1642 // address we can tie back to a CU.
1643 void DwarfDebug::emitDebugARanges() {
1644 // Provides a unique id per text section.
1645 MapVector<const MCSection *, SmallVector<SymbolCU, 8>> SectionMap;
1647 // Filter labels by section.
1648 for (const SymbolCU &SCU : ArangeLabels) {
1649 if (SCU.Sym->isInSection()) {
1650 // Make a note of this symbol and it's section.
1651 const MCSection *Section = &SCU.Sym->getSection();
1652 if (!Section->getKind().isMetadata())
1653 SectionMap[Section].push_back(SCU);
1655 // Some symbols (e.g. common/bss on mach-o) can have no section but still
1656 // appear in the output. This sucks as we rely on sections to build
1657 // arange spans. We can do it without, but it's icky.
1658 SectionMap[nullptr].push_back(SCU);
1662 // Add terminating symbols for each section.
1663 for (const auto &I : SectionMap) {
1664 const MCSection *Section = I.first;
1665 MCSymbol *Sym = nullptr;
1668 Sym = Asm->OutStreamer.endSection(Section);
1670 // Insert a final terminator.
1671 SectionMap[Section].push_back(SymbolCU(nullptr, Sym));
1674 DenseMap<DwarfCompileUnit *, std::vector<ArangeSpan>> Spans;
1676 for (auto &I : SectionMap) {
1677 const MCSection *Section = I.first;
1678 SmallVector<SymbolCU, 8> &List = I.second;
1679 if (List.size() < 2)
1682 // If we have no section (e.g. common), just write out
1683 // individual spans for each symbol.
1685 for (const SymbolCU &Cur : List) {
1687 Span.Start = Cur.Sym;
1690 Spans[Cur.CU].push_back(Span);
1695 // Sort the symbols by offset within the section.
1696 std::sort(List.begin(), List.end(),
1697 [&](const SymbolCU &A, const SymbolCU &B) {
1698 unsigned IA = A.Sym ? Asm->OutStreamer.GetSymbolOrder(A.Sym) : 0;
1699 unsigned IB = B.Sym ? Asm->OutStreamer.GetSymbolOrder(B.Sym) : 0;
1701 // Symbols with no order assigned should be placed at the end.
1702 // (e.g. section end labels)
1710 // Build spans between each label.
1711 const MCSymbol *StartSym = List[0].Sym;
1712 for (size_t n = 1, e = List.size(); n < e; n++) {
1713 const SymbolCU &Prev = List[n - 1];
1714 const SymbolCU &Cur = List[n];
1716 // Try and build the longest span we can within the same CU.
1717 if (Cur.CU != Prev.CU) {
1719 Span.Start = StartSym;
1721 Spans[Prev.CU].push_back(Span);
1727 // Start the dwarf aranges section.
1728 Asm->OutStreamer.SwitchSection(
1729 Asm->getObjFileLowering().getDwarfARangesSection());
1731 unsigned PtrSize = Asm->getDataLayout().getPointerSize();
1733 // Build a list of CUs used.
1734 std::vector<DwarfCompileUnit *> CUs;
1735 for (const auto &it : Spans) {
1736 DwarfCompileUnit *CU = it.first;
1740 // Sort the CU list (again, to ensure consistent output order).
1741 std::sort(CUs.begin(), CUs.end(), [](const DwarfUnit *A, const DwarfUnit *B) {
1742 return A->getUniqueID() < B->getUniqueID();
1745 // Emit an arange table for each CU we used.
1746 for (DwarfCompileUnit *CU : CUs) {
1747 std::vector<ArangeSpan> &List = Spans[CU];
1749 // Describe the skeleton CU's offset and length, not the dwo file's.
1750 if (auto *Skel = CU->getSkeleton())
1753 // Emit size of content not including length itself.
1754 unsigned ContentSize =
1755 sizeof(int16_t) + // DWARF ARange version number
1756 sizeof(int32_t) + // Offset of CU in the .debug_info section
1757 sizeof(int8_t) + // Pointer Size (in bytes)
1758 sizeof(int8_t); // Segment Size (in bytes)
1760 unsigned TupleSize = PtrSize * 2;
1762 // 7.20 in the Dwarf specs requires the table to be aligned to a tuple.
1764 OffsetToAlignment(sizeof(int32_t) + ContentSize, TupleSize);
1766 ContentSize += Padding;
1767 ContentSize += (List.size() + 1) * TupleSize;
1769 // For each compile unit, write the list of spans it covers.
1770 Asm->OutStreamer.AddComment("Length of ARange Set");
1771 Asm->EmitInt32(ContentSize);
1772 Asm->OutStreamer.AddComment("DWARF Arange version number");
1773 Asm->EmitInt16(dwarf::DW_ARANGES_VERSION);
1774 Asm->OutStreamer.AddComment("Offset Into Debug Info Section");
1775 Asm->emitSectionOffset(CU->getLabelBegin());
1776 Asm->OutStreamer.AddComment("Address Size (in bytes)");
1777 Asm->EmitInt8(PtrSize);
1778 Asm->OutStreamer.AddComment("Segment Size (in bytes)");
1781 Asm->OutStreamer.EmitFill(Padding, 0xff);
1783 for (const ArangeSpan &Span : List) {
1784 Asm->EmitLabelReference(Span.Start, PtrSize);
1786 // Calculate the size as being from the span start to it's end.
1788 Asm->EmitLabelDifference(Span.End, Span.Start, PtrSize);
1790 // For symbols without an end marker (e.g. common), we
1791 // write a single arange entry containing just that one symbol.
1792 uint64_t Size = SymSize[Span.Start];
1796 Asm->OutStreamer.EmitIntValue(Size, PtrSize);
1800 Asm->OutStreamer.AddComment("ARange terminator");
1801 Asm->OutStreamer.EmitIntValue(0, PtrSize);
1802 Asm->OutStreamer.EmitIntValue(0, PtrSize);
1806 // Emit visible names into a debug ranges section.
1807 void DwarfDebug::emitDebugRanges() {
1808 // Start the dwarf ranges section.
1809 Asm->OutStreamer.SwitchSection(
1810 Asm->getObjFileLowering().getDwarfRangesSection());
1812 // Size for our labels.
1813 unsigned char Size = Asm->getDataLayout().getPointerSize();
1815 // Grab the specific ranges for the compile units in the module.
1816 for (const auto &I : CUMap) {
1817 DwarfCompileUnit *TheCU = I.second;
1819 if (auto *Skel = TheCU->getSkeleton())
1822 // Iterate over the misc ranges for the compile units in the module.
1823 for (const RangeSpanList &List : TheCU->getRangeLists()) {
1824 // Emit our symbol so we can find the beginning of the range.
1825 Asm->OutStreamer.EmitLabel(List.getSym());
1827 for (const RangeSpan &Range : List.getRanges()) {
1828 const MCSymbol *Begin = Range.getStart();
1829 const MCSymbol *End = Range.getEnd();
1830 assert(Begin && "Range without a begin symbol?");
1831 assert(End && "Range without an end symbol?");
1832 if (auto *Base = TheCU->getBaseAddress()) {
1833 Asm->EmitLabelDifference(Begin, Base, Size);
1834 Asm->EmitLabelDifference(End, Base, Size);
1836 Asm->OutStreamer.EmitSymbolValue(Begin, Size);
1837 Asm->OutStreamer.EmitSymbolValue(End, Size);
1841 // And terminate the list with two 0 values.
1842 Asm->OutStreamer.EmitIntValue(0, Size);
1843 Asm->OutStreamer.EmitIntValue(0, Size);
1848 // DWARF5 Experimental Separate Dwarf emitters.
1850 void DwarfDebug::initSkeletonUnit(const DwarfUnit &U, DIE &Die,
1851 std::unique_ptr<DwarfUnit> NewU) {
1852 NewU->addString(Die, dwarf::DW_AT_GNU_dwo_name,
1853 U.getCUNode().getSplitDebugFilename());
1855 if (!CompilationDir.empty())
1856 NewU->addString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
1858 addGnuPubAttributes(*NewU, Die);
1860 SkeletonHolder.addUnit(std::move(NewU));
1863 // This DIE has the following attributes: DW_AT_comp_dir, DW_AT_stmt_list,
1864 // DW_AT_low_pc, DW_AT_high_pc, DW_AT_ranges, DW_AT_dwo_name, DW_AT_dwo_id,
1865 // DW_AT_addr_base, DW_AT_ranges_base.
1866 DwarfCompileUnit &DwarfDebug::constructSkeletonCU(const DwarfCompileUnit &CU) {
1868 auto OwnedUnit = make_unique<DwarfCompileUnit>(
1869 CU.getUniqueID(), CU.getCUNode(), Asm, this, &SkeletonHolder);
1870 DwarfCompileUnit &NewCU = *OwnedUnit;
1871 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoSection());
1873 NewCU.initStmtList();
1875 initSkeletonUnit(CU, NewCU.getUnitDie(), std::move(OwnedUnit));
1880 // Emit the .debug_info.dwo section for separated dwarf. This contains the
1881 // compile units that would normally be in debug_info.
1882 void DwarfDebug::emitDebugInfoDWO() {
1883 assert(useSplitDwarf() && "No split dwarf debug info?");
1884 // Don't emit relocations into the dwo file.
1885 InfoHolder.emitUnits(/* UseOffsets */ true);
1888 // Emit the .debug_abbrev.dwo section for separated dwarf. This contains the
1889 // abbreviations for the .debug_info.dwo section.
1890 void DwarfDebug::emitDebugAbbrevDWO() {
1891 assert(useSplitDwarf() && "No split dwarf?");
1892 InfoHolder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevDWOSection());
1895 void DwarfDebug::emitDebugLineDWO() {
1896 assert(useSplitDwarf() && "No split dwarf?");
1897 Asm->OutStreamer.SwitchSection(
1898 Asm->getObjFileLowering().getDwarfLineDWOSection());
1899 SplitTypeUnitFileTable.Emit(Asm->OutStreamer);
1902 // Emit the .debug_str.dwo section for separated dwarf. This contains the
1903 // string section and is identical in format to traditional .debug_str
1905 void DwarfDebug::emitDebugStrDWO() {
1906 assert(useSplitDwarf() && "No split dwarf?");
1907 const MCSection *OffSec =
1908 Asm->getObjFileLowering().getDwarfStrOffDWOSection();
1909 InfoHolder.emitStrings(Asm->getObjFileLowering().getDwarfStrDWOSection(),
1913 MCDwarfDwoLineTable *DwarfDebug::getDwoLineTable(const DwarfCompileUnit &CU) {
1914 if (!useSplitDwarf())
1917 SplitTypeUnitFileTable.setCompilationDir(CU.getCUNode().getDirectory());
1918 return &SplitTypeUnitFileTable;
1921 static uint64_t makeTypeSignature(StringRef Identifier) {
1923 Hash.update(Identifier);
1924 // ... take the least significant 8 bytes and return those. Our MD5
1925 // implementation always returns its results in little endian, swap bytes
1927 MD5::MD5Result Result;
1929 return support::endian::read64le(Result + 8);
1932 void DwarfDebug::addDwarfTypeUnitType(DwarfCompileUnit &CU,
1933 StringRef Identifier, DIE &RefDie,
1934 DICompositeType CTy) {
1935 // Fast path if we're building some type units and one has already used the
1936 // address pool we know we're going to throw away all this work anyway, so
1937 // don't bother building dependent types.
1938 if (!TypeUnitsUnderConstruction.empty() && AddrPool.hasBeenUsed())
1941 const DwarfTypeUnit *&TU = DwarfTypeUnits[CTy];
1943 CU.addDIETypeSignature(RefDie, *TU);
1947 bool TopLevelType = TypeUnitsUnderConstruction.empty();
1948 AddrPool.resetUsedFlag();
1950 auto OwnedUnit = make_unique<DwarfTypeUnit>(
1951 InfoHolder.getUnits().size() + TypeUnitsUnderConstruction.size(), CU, Asm,
1952 this, &InfoHolder, getDwoLineTable(CU));
1953 DwarfTypeUnit &NewTU = *OwnedUnit;
1954 DIE &UnitDie = NewTU.getUnitDie();
1956 TypeUnitsUnderConstruction.push_back(
1957 std::make_pair(std::move(OwnedUnit), CTy));
1959 NewTU.addUInt(UnitDie, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
1962 uint64_t Signature = makeTypeSignature(Identifier);
1963 NewTU.setTypeSignature(Signature);
1965 if (useSplitDwarf())
1966 NewTU.initSection(Asm->getObjFileLowering().getDwarfTypesDWOSection());
1968 CU.applyStmtList(UnitDie);
1970 Asm->getObjFileLowering().getDwarfTypesSection(Signature));
1973 NewTU.setType(NewTU.createTypeDIE(CTy));
1976 auto TypeUnitsToAdd = std::move(TypeUnitsUnderConstruction);
1977 TypeUnitsUnderConstruction.clear();
1979 // Types referencing entries in the address table cannot be placed in type
1981 if (AddrPool.hasBeenUsed()) {
1983 // Remove all the types built while building this type.
1984 // This is pessimistic as some of these types might not be dependent on
1985 // the type that used an address.
1986 for (const auto &TU : TypeUnitsToAdd)
1987 DwarfTypeUnits.erase(TU.second);
1989 // Construct this type in the CU directly.
1990 // This is inefficient because all the dependent types will be rebuilt
1991 // from scratch, including building them in type units, discovering that
1992 // they depend on addresses, throwing them out and rebuilding them.
1993 CU.constructTypeDIE(RefDie, CTy);
1997 // If the type wasn't dependent on fission addresses, finish adding the type
1998 // and all its dependent types.
1999 for (auto &TU : TypeUnitsToAdd)
2000 InfoHolder.addUnit(std::move(TU.first));
2002 CU.addDIETypeSignature(RefDie, NewTU);
2005 // Accelerator table mutators - add each name along with its companion
2006 // DIE to the proper table while ensuring that the name that we're going
2007 // to reference is in the string table. We do this since the names we
2008 // add may not only be identical to the names in the DIE.
2009 void DwarfDebug::addAccelName(StringRef Name, const DIE &Die) {
2010 if (!useDwarfAccelTables())
2012 AccelNames.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2016 void DwarfDebug::addAccelObjC(StringRef Name, const DIE &Die) {
2017 if (!useDwarfAccelTables())
2019 AccelObjC.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2023 void DwarfDebug::addAccelNamespace(StringRef Name, const DIE &Die) {
2024 if (!useDwarfAccelTables())
2026 AccelNamespace.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2030 void DwarfDebug::addAccelType(StringRef Name, const DIE &Die, char Flags) {
2031 if (!useDwarfAccelTables())
2033 AccelTypes.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),