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(ScopeNode));
711 DwarfDebug::ensureAbstractVariableIsCreatedIfScoped(const DIVariable &DV,
712 const MDNode *ScopeNode) {
713 DIVariable Cleansed = DV;
714 if (getExistingAbstractVariable(DV, Cleansed))
717 if (LexicalScope *Scope = LScopes.findAbstractScope(ScopeNode))
718 createAbstractVariable(Cleansed, Scope);
721 // Collect variable information from side table maintained by MMI.
722 void DwarfDebug::collectVariableInfoFromMMITable(
723 SmallPtrSetImpl<const MDNode *> &Processed) {
724 for (const auto &VI : MMI->getVariableDbgInfo()) {
727 Processed.insert(VI.Var);
728 LexicalScope *Scope = LScopes.findLexicalScope(VI.Loc);
730 // If variable scope is not found then skip this variable.
734 DIVariable DV(VI.Var);
735 DIExpression Expr(VI.Expr);
736 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
737 auto RegVar = make_unique<DbgVariable>(DV, Expr, this, VI.Slot);
738 if (InfoHolder.addScopeVariable(Scope, RegVar.get()))
739 ConcreteVariables.push_back(std::move(RegVar));
743 // Get .debug_loc entry for the instruction range starting at MI.
744 static DebugLocEntry::Value getDebugLocValue(const MachineInstr *MI) {
745 const MDNode *Expr = MI->getDebugExpression();
746 const MDNode *Var = MI->getDebugVariable();
748 assert(MI->getNumOperands() == 4);
749 if (MI->getOperand(0).isReg()) {
750 MachineLocation MLoc;
751 // If the second operand is an immediate, this is a
752 // register-indirect address.
753 if (!MI->getOperand(1).isImm())
754 MLoc.set(MI->getOperand(0).getReg());
756 MLoc.set(MI->getOperand(0).getReg(), MI->getOperand(1).getImm());
757 return DebugLocEntry::Value(Var, Expr, MLoc);
759 if (MI->getOperand(0).isImm())
760 return DebugLocEntry::Value(Var, Expr, MI->getOperand(0).getImm());
761 if (MI->getOperand(0).isFPImm())
762 return DebugLocEntry::Value(Var, Expr, MI->getOperand(0).getFPImm());
763 if (MI->getOperand(0).isCImm())
764 return DebugLocEntry::Value(Var, Expr, MI->getOperand(0).getCImm());
766 llvm_unreachable("Unexpected 4-operand DBG_VALUE instruction!");
769 /// Determine whether two variable pieces overlap.
770 static bool piecesOverlap(DIExpression P1, DIExpression P2) {
771 if (!P1.isBitPiece() || !P2.isBitPiece())
773 unsigned l1 = P1.getBitPieceOffset();
774 unsigned l2 = P2.getBitPieceOffset();
775 unsigned r1 = l1 + P1.getBitPieceSize();
776 unsigned r2 = l2 + P2.getBitPieceSize();
777 // True where [l1,r1[ and [r1,r2[ overlap.
778 return (l1 < r2) && (l2 < r1);
781 /// Build the location list for all DBG_VALUEs in the function that
782 /// describe the same variable. If the ranges of several independent
783 /// pieces of the same variable overlap partially, split them up and
784 /// combine the ranges. The resulting DebugLocEntries are will have
785 /// strict monotonically increasing begin addresses and will never
790 // Ranges History [var, loc, piece ofs size]
791 // 0 | [x, (reg0, piece 0, 32)]
792 // 1 | | [x, (reg1, piece 32, 32)] <- IsPieceOfPrevEntry
794 // 3 | [clobber reg0]
795 // 4 [x, (mem, piece 0, 64)] <- overlapping with both previous pieces of
800 // [0-1] [x, (reg0, piece 0, 32)]
801 // [1-3] [x, (reg0, piece 0, 32), (reg1, piece 32, 32)]
802 // [3-4] [x, (reg1, piece 32, 32)]
803 // [4- ] [x, (mem, piece 0, 64)]
805 DwarfDebug::buildLocationList(SmallVectorImpl<DebugLocEntry> &DebugLoc,
806 const DbgValueHistoryMap::InstrRanges &Ranges) {
807 SmallVector<DebugLocEntry::Value, 4> OpenRanges;
809 for (auto I = Ranges.begin(), E = Ranges.end(); I != E; ++I) {
810 const MachineInstr *Begin = I->first;
811 const MachineInstr *End = I->second;
812 assert(Begin->isDebugValue() && "Invalid History entry");
814 // Check if a variable is inaccessible in this range.
815 if (Begin->getNumOperands() > 1 &&
816 Begin->getOperand(0).isReg() && !Begin->getOperand(0).getReg()) {
821 // If this piece overlaps with any open ranges, truncate them.
822 DIExpression DIExpr = Begin->getDebugExpression();
823 auto Last = std::remove_if(OpenRanges.begin(), OpenRanges.end(),
824 [&](DebugLocEntry::Value R) {
825 return piecesOverlap(DIExpr, R.getExpression());
827 OpenRanges.erase(Last, OpenRanges.end());
829 const MCSymbol *StartLabel = getLabelBeforeInsn(Begin);
830 assert(StartLabel && "Forgot label before DBG_VALUE starting a range!");
832 const MCSymbol *EndLabel;
834 EndLabel = getLabelAfterInsn(End);
835 else if (std::next(I) == Ranges.end())
836 EndLabel = Asm->getFunctionEnd();
838 EndLabel = getLabelBeforeInsn(std::next(I)->first);
839 assert(EndLabel && "Forgot label after instruction ending a range!");
841 DEBUG(dbgs() << "DotDebugLoc: " << *Begin << "\n");
843 auto Value = getDebugLocValue(Begin);
844 DebugLocEntry Loc(StartLabel, EndLabel, Value);
845 bool couldMerge = false;
847 // If this is a piece, it may belong to the current DebugLocEntry.
848 if (DIExpr.isBitPiece()) {
849 // Add this value to the list of open ranges.
850 OpenRanges.push_back(Value);
852 // Attempt to add the piece to the last entry.
853 if (!DebugLoc.empty())
854 if (DebugLoc.back().MergeValues(Loc))
859 // Need to add a new DebugLocEntry. Add all values from still
860 // valid non-overlapping pieces.
861 if (OpenRanges.size())
862 Loc.addValues(OpenRanges);
864 DebugLoc.push_back(std::move(Loc));
867 // Attempt to coalesce the ranges of two otherwise identical
869 auto CurEntry = DebugLoc.rbegin();
870 auto PrevEntry = std::next(CurEntry);
871 if (PrevEntry != DebugLoc.rend() && PrevEntry->MergeRanges(*CurEntry))
875 dbgs() << CurEntry->getValues().size() << " Values:\n";
876 for (auto Value : CurEntry->getValues()) {
877 Value.getVariable()->dump();
878 Value.getExpression()->dump();
886 // Find variables for each lexical scope.
888 DwarfDebug::collectVariableInfo(DwarfCompileUnit &TheCU, DISubprogram SP,
889 SmallPtrSetImpl<const MDNode *> &Processed) {
890 // Grab the variable info that was squirreled away in the MMI side-table.
891 collectVariableInfoFromMMITable(Processed);
893 for (const auto &I : DbgValues) {
894 DIVariable DV(I.first);
895 if (Processed.count(DV))
898 // Instruction ranges, specifying where DV is accessible.
899 const auto &Ranges = I.second;
903 LexicalScope *Scope = nullptr;
904 if (MDNode *IA = DV.getInlinedAt())
905 Scope = LScopes.findInlinedScope(DV.getContext(), IA);
907 Scope = LScopes.findLexicalScope(DV.getContext());
908 // If variable scope is not found then skip this variable.
912 Processed.insert(DV);
913 const MachineInstr *MInsn = Ranges.front().first;
914 assert(MInsn->isDebugValue() && "History must begin with debug value");
915 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
916 ConcreteVariables.push_back(make_unique<DbgVariable>(MInsn, this));
917 DbgVariable *RegVar = ConcreteVariables.back().get();
918 InfoHolder.addScopeVariable(Scope, RegVar);
920 // Check if the first DBG_VALUE is valid for the rest of the function.
921 if (Ranges.size() == 1 && Ranges.front().second == nullptr)
924 // Handle multiple DBG_VALUE instructions describing one variable.
925 RegVar->setDotDebugLocOffset(DotDebugLocEntries.size());
927 DotDebugLocEntries.resize(DotDebugLocEntries.size() + 1);
928 DebugLocList &LocList = DotDebugLocEntries.back();
930 LocList.Label = Asm->createTempSymbol("debug_loc");
932 // Build the location list for this variable.
933 buildLocationList(LocList.List, Ranges);
934 // Finalize the entry by lowering it into a DWARF bytestream.
935 for (auto &Entry : LocList.List)
936 Entry.finalize(*Asm, TypeIdentifierMap);
939 // Collect info for variables that were optimized out.
940 DIArray Variables = SP.getVariables();
941 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
942 DIVariable DV(Variables.getElement(i));
943 assert(DV.isVariable());
944 if (!Processed.insert(DV).second)
946 if (LexicalScope *Scope = LScopes.findLexicalScope(DV.getContext())) {
947 ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
949 ConcreteVariables.push_back(make_unique<DbgVariable>(DV, NoExpr, this));
950 InfoHolder.addScopeVariable(Scope, ConcreteVariables.back().get());
955 // Return Label preceding the instruction.
956 MCSymbol *DwarfDebug::getLabelBeforeInsn(const MachineInstr *MI) {
957 MCSymbol *Label = LabelsBeforeInsn.lookup(MI);
958 assert(Label && "Didn't insert label before instruction");
962 // Return Label immediately following the instruction.
963 MCSymbol *DwarfDebug::getLabelAfterInsn(const MachineInstr *MI) {
964 return LabelsAfterInsn.lookup(MI);
967 // Process beginning of an instruction.
968 void DwarfDebug::beginInstruction(const MachineInstr *MI) {
969 assert(CurMI == nullptr);
971 // Check if source location changes, but ignore DBG_VALUE locations.
972 if (!MI->isDebugValue()) {
973 DebugLoc DL = MI->getDebugLoc();
974 if (DL != PrevInstLoc) {
978 if (DL == PrologEndLoc) {
979 Flags |= DWARF2_FLAG_PROLOGUE_END;
980 PrologEndLoc = DebugLoc();
981 Flags |= DWARF2_FLAG_IS_STMT;
984 Asm->OutStreamer.getContext().getCurrentDwarfLoc().getLine())
985 Flags |= DWARF2_FLAG_IS_STMT;
987 const MDNode *Scope = DL.getScope();
988 recordSourceLine(DL.getLine(), DL.getCol(), Scope, Flags);
989 } else if (UnknownLocations) {
991 recordSourceLine(0, 0, nullptr, 0);
996 // Insert labels where requested.
997 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
998 LabelsBeforeInsn.find(MI);
1001 if (I == LabelsBeforeInsn.end())
1004 // Label already assigned.
1009 PrevLabel = MMI->getContext().CreateTempSymbol();
1010 Asm->OutStreamer.EmitLabel(PrevLabel);
1012 I->second = PrevLabel;
1015 // Process end of an instruction.
1016 void DwarfDebug::endInstruction() {
1017 assert(CurMI != nullptr);
1018 // Don't create a new label after DBG_VALUE instructions.
1019 // They don't generate code.
1020 if (!CurMI->isDebugValue())
1021 PrevLabel = nullptr;
1023 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1024 LabelsAfterInsn.find(CurMI);
1028 if (I == LabelsAfterInsn.end())
1031 // Label already assigned.
1035 // We need a label after this instruction.
1037 PrevLabel = MMI->getContext().CreateTempSymbol();
1038 Asm->OutStreamer.EmitLabel(PrevLabel);
1040 I->second = PrevLabel;
1043 // Each LexicalScope has first instruction and last instruction to mark
1044 // beginning and end of a scope respectively. Create an inverse map that list
1045 // scopes starts (and ends) with an instruction. One instruction may start (or
1046 // end) multiple scopes. Ignore scopes that are not reachable.
1047 void DwarfDebug::identifyScopeMarkers() {
1048 SmallVector<LexicalScope *, 4> WorkList;
1049 WorkList.push_back(LScopes.getCurrentFunctionScope());
1050 while (!WorkList.empty()) {
1051 LexicalScope *S = WorkList.pop_back_val();
1053 const SmallVectorImpl<LexicalScope *> &Children = S->getChildren();
1054 if (!Children.empty())
1055 WorkList.append(Children.begin(), Children.end());
1057 if (S->isAbstractScope())
1060 for (const InsnRange &R : S->getRanges()) {
1061 assert(R.first && "InsnRange does not have first instruction!");
1062 assert(R.second && "InsnRange does not have second instruction!");
1063 requestLabelBeforeInsn(R.first);
1064 requestLabelAfterInsn(R.second);
1069 static DebugLoc findPrologueEndLoc(const MachineFunction *MF) {
1070 // First known non-DBG_VALUE and non-frame setup location marks
1071 // the beginning of the function body.
1072 for (const auto &MBB : *MF)
1073 for (const auto &MI : MBB)
1074 if (!MI.isDebugValue() && !MI.getFlag(MachineInstr::FrameSetup) &&
1076 // Did the target forget to set the FrameSetup flag for CFI insns?
1077 assert(!MI.isCFIInstruction() &&
1078 "First non-frame-setup instruction is a CFI instruction.");
1079 return MI.getDebugLoc();
1084 // Gather pre-function debug information. Assumes being called immediately
1085 // after the function entry point has been emitted.
1086 void DwarfDebug::beginFunction(const MachineFunction *MF) {
1089 // If there's no debug info for the function we're not going to do anything.
1090 if (!MMI->hasDebugInfo())
1093 auto DI = FunctionDIs.find(MF->getFunction());
1094 if (DI == FunctionDIs.end())
1097 // Grab the lexical scopes for the function, if we don't have any of those
1098 // then we're not going to be able to do anything.
1099 LScopes.initialize(*MF);
1100 if (LScopes.empty())
1103 assert(DbgValues.empty() && "DbgValues map wasn't cleaned!");
1105 // Make sure that each lexical scope will have a begin/end label.
1106 identifyScopeMarkers();
1108 // Set DwarfDwarfCompileUnitID in MCContext to the Compile Unit this function
1109 // belongs to so that we add to the correct per-cu line table in the
1111 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1112 // FnScope->getScopeNode() and DI->second should represent the same function,
1113 // though they may not be the same MDNode due to inline functions merged in
1114 // LTO where the debug info metadata still differs (either due to distinct
1115 // written differences - two versions of a linkonce_odr function
1116 // written/copied into two separate files, or some sub-optimal metadata that
1117 // isn't structurally identical (see: file path/name info from clang, which
1118 // includes the directory of the cpp file being built, even when the file name
1119 // is absolute (such as an <> lookup header)))
1120 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1121 assert(TheCU && "Unable to find compile unit!");
1122 if (Asm->OutStreamer.hasRawTextSupport())
1123 // Use a single line table if we are generating assembly.
1124 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1126 Asm->OutStreamer.getContext().setDwarfCompileUnitID(TheCU->getUniqueID());
1128 // Calculate history for local variables.
1129 calculateDbgValueHistory(MF, Asm->MF->getSubtarget().getRegisterInfo(),
1132 // Request labels for the full history.
1133 for (const auto &I : DbgValues) {
1134 const auto &Ranges = I.second;
1138 // The first mention of a function argument gets the CurrentFnBegin
1139 // label, so arguments are visible when breaking at function entry.
1140 DIVariable DIVar(Ranges.front().first->getDebugVariable());
1141 if (DIVar.isVariable() && DIVar.getTag() == dwarf::DW_TAG_arg_variable &&
1142 getDISubprogram(DIVar.getContext()).describes(MF->getFunction())) {
1143 LabelsBeforeInsn[Ranges.front().first] = Asm->getFunctionBegin();
1144 if (Ranges.front().first->getDebugExpression().isBitPiece()) {
1145 // Mark all non-overlapping initial pieces.
1146 for (auto I = Ranges.begin(); I != Ranges.end(); ++I) {
1147 DIExpression Piece = I->first->getDebugExpression();
1148 if (std::all_of(Ranges.begin(), I,
1149 [&](DbgValueHistoryMap::InstrRange Pred) {
1150 return !piecesOverlap(Piece, Pred.first->getDebugExpression());
1152 LabelsBeforeInsn[I->first] = Asm->getFunctionBegin();
1159 for (const auto &Range : Ranges) {
1160 requestLabelBeforeInsn(Range.first);
1162 requestLabelAfterInsn(Range.second);
1166 PrevInstLoc = DebugLoc();
1167 PrevLabel = Asm->getFunctionBegin();
1169 // Record beginning of function.
1170 PrologEndLoc = findPrologueEndLoc(MF);
1171 if (MDLocation *L = PrologEndLoc) {
1172 // We'd like to list the prologue as "not statements" but GDB behaves
1173 // poorly if we do that. Revisit this with caution/GDB (7.5+) testing.
1174 auto *SP = L->getInlinedAtScope()->getSubprogram();
1175 recordSourceLine(SP->getScopeLine(), 0, SP, DWARF2_FLAG_IS_STMT);
1179 // Gather and emit post-function debug information.
1180 void DwarfDebug::endFunction(const MachineFunction *MF) {
1181 assert(CurFn == MF &&
1182 "endFunction should be called with the same function as beginFunction");
1184 if (!MMI->hasDebugInfo() || LScopes.empty() ||
1185 !FunctionDIs.count(MF->getFunction())) {
1186 // If we don't have a lexical scope for this function then there will
1187 // be a hole in the range information. Keep note of this by setting the
1188 // previously used section to nullptr.
1194 // Set DwarfDwarfCompileUnitID in MCContext to default value.
1195 Asm->OutStreamer.getContext().setDwarfCompileUnitID(0);
1197 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1198 DISubprogram SP(FnScope->getScopeNode());
1199 DwarfCompileUnit &TheCU = *SPMap.lookup(SP);
1201 SmallPtrSet<const MDNode *, 16> ProcessedVars;
1202 collectVariableInfo(TheCU, SP, ProcessedVars);
1204 // Add the range of this function to the list of ranges for the CU.
1205 TheCU.addRange(RangeSpan(Asm->getFunctionBegin(), Asm->getFunctionEnd()));
1207 // Under -gmlt, skip building the subprogram if there are no inlined
1208 // subroutines inside it.
1209 if (TheCU.getCUNode().getEmissionKind() == DIBuilder::LineTablesOnly &&
1210 LScopes.getAbstractScopesList().empty() && !IsDarwin) {
1211 assert(InfoHolder.getScopeVariables().empty());
1212 assert(DbgValues.empty());
1213 // FIXME: This wouldn't be true in LTO with a -g (with inlining) CU followed
1214 // by a -gmlt CU. Add a test and remove this assertion.
1215 assert(AbstractVariables.empty());
1216 LabelsBeforeInsn.clear();
1217 LabelsAfterInsn.clear();
1218 PrevLabel = nullptr;
1224 size_t NumAbstractScopes = LScopes.getAbstractScopesList().size();
1226 // Construct abstract scopes.
1227 for (LexicalScope *AScope : LScopes.getAbstractScopesList()) {
1228 DISubprogram SP(AScope->getScopeNode());
1229 assert(SP.isSubprogram());
1230 // Collect info for variables that were optimized out.
1231 DIArray Variables = SP.getVariables();
1232 for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
1233 DIVariable DV(Variables.getElement(i));
1234 assert(DV && DV.isVariable());
1235 if (!ProcessedVars.insert(DV).second)
1237 ensureAbstractVariableIsCreated(DV, DV.getContext());
1238 assert(LScopes.getAbstractScopesList().size() == NumAbstractScopes
1239 && "ensureAbstractVariableIsCreated inserted abstract scopes");
1241 constructAbstractSubprogramScopeDIE(AScope);
1244 TheCU.constructSubprogramScopeDIE(FnScope);
1245 if (auto *SkelCU = TheCU.getSkeleton())
1246 if (!LScopes.getAbstractScopesList().empty())
1247 SkelCU->constructSubprogramScopeDIE(FnScope);
1250 // Ownership of DbgVariables is a bit subtle - ScopeVariables owns all the
1251 // DbgVariables except those that are also in AbstractVariables (since they
1252 // can be used cross-function)
1253 InfoHolder.getScopeVariables().clear();
1255 LabelsBeforeInsn.clear();
1256 LabelsAfterInsn.clear();
1257 PrevLabel = nullptr;
1261 // Register a source line with debug info. Returns the unique label that was
1262 // emitted and which provides correspondence to the source line list.
1263 void DwarfDebug::recordSourceLine(unsigned Line, unsigned Col, const MDNode *S,
1268 unsigned Discriminator = 0;
1269 if (DIScope Scope = DIScope(S)) {
1270 assert(Scope.isScope());
1271 Fn = Scope.getFilename();
1272 Dir = Scope.getDirectory();
1273 if (Scope.isLexicalBlockFile())
1274 Discriminator = DILexicalBlockFile(S).getDiscriminator();
1276 unsigned CUID = Asm->OutStreamer.getContext().getDwarfCompileUnitID();
1277 Src = static_cast<DwarfCompileUnit &>(*InfoHolder.getUnits()[CUID])
1278 .getOrCreateSourceID(Fn, Dir);
1280 Asm->OutStreamer.EmitDwarfLocDirective(Src, Line, Col, Flags, 0,
1284 //===----------------------------------------------------------------------===//
1286 //===----------------------------------------------------------------------===//
1288 // Emit the debug info section.
1289 void DwarfDebug::emitDebugInfo() {
1290 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1291 Holder.emitUnits(/* UseOffsets */ false);
1294 // Emit the abbreviation section.
1295 void DwarfDebug::emitAbbreviations() {
1296 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1298 Holder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevSection());
1301 void DwarfDebug::emitAccel(DwarfAccelTable &Accel, const MCSection *Section,
1302 StringRef TableName) {
1303 Accel.FinalizeTable(Asm, TableName);
1304 Asm->OutStreamer.SwitchSection(Section);
1306 // Emit the full data.
1307 Accel.emit(Asm, Section->getBeginSymbol(), this);
1310 // Emit visible names into a hashed accelerator table section.
1311 void DwarfDebug::emitAccelNames() {
1312 emitAccel(AccelNames, Asm->getObjFileLowering().getDwarfAccelNamesSection(),
1316 // Emit objective C classes and categories into a hashed accelerator table
1318 void DwarfDebug::emitAccelObjC() {
1319 emitAccel(AccelObjC, Asm->getObjFileLowering().getDwarfAccelObjCSection(),
1323 // Emit namespace dies into a hashed accelerator table.
1324 void DwarfDebug::emitAccelNamespaces() {
1325 emitAccel(AccelNamespace,
1326 Asm->getObjFileLowering().getDwarfAccelNamespaceSection(),
1330 // Emit type dies into a hashed accelerator table.
1331 void DwarfDebug::emitAccelTypes() {
1332 emitAccel(AccelTypes, Asm->getObjFileLowering().getDwarfAccelTypesSection(),
1336 // Public name handling.
1337 // The format for the various pubnames:
1339 // dwarf pubnames - offset/name pairs where the offset is the offset into the CU
1340 // for the DIE that is named.
1342 // gnu pubnames - offset/index value/name tuples where the offset is the offset
1343 // into the CU and the index value is computed according to the type of value
1344 // for the DIE that is named.
1346 // For type units the offset is the offset of the skeleton DIE. For split dwarf
1347 // it's the offset within the debug_info/debug_types dwo section, however, the
1348 // reference in the pubname header doesn't change.
1350 /// computeIndexValue - Compute the gdb index value for the DIE and CU.
1351 static dwarf::PubIndexEntryDescriptor computeIndexValue(DwarfUnit *CU,
1353 dwarf::GDBIndexEntryLinkage Linkage = dwarf::GIEL_STATIC;
1355 // We could have a specification DIE that has our most of our knowledge,
1356 // look for that now.
1357 DIEValue *SpecVal = Die->findAttribute(dwarf::DW_AT_specification);
1359 DIE &SpecDIE = cast<DIEEntry>(SpecVal)->getEntry();
1360 if (SpecDIE.findAttribute(dwarf::DW_AT_external))
1361 Linkage = dwarf::GIEL_EXTERNAL;
1362 } else if (Die->findAttribute(dwarf::DW_AT_external))
1363 Linkage = dwarf::GIEL_EXTERNAL;
1365 switch (Die->getTag()) {
1366 case dwarf::DW_TAG_class_type:
1367 case dwarf::DW_TAG_structure_type:
1368 case dwarf::DW_TAG_union_type:
1369 case dwarf::DW_TAG_enumeration_type:
1370 return dwarf::PubIndexEntryDescriptor(
1371 dwarf::GIEK_TYPE, CU->getLanguage() != dwarf::DW_LANG_C_plus_plus
1372 ? dwarf::GIEL_STATIC
1373 : dwarf::GIEL_EXTERNAL);
1374 case dwarf::DW_TAG_typedef:
1375 case dwarf::DW_TAG_base_type:
1376 case dwarf::DW_TAG_subrange_type:
1377 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_TYPE, dwarf::GIEL_STATIC);
1378 case dwarf::DW_TAG_namespace:
1379 return dwarf::GIEK_TYPE;
1380 case dwarf::DW_TAG_subprogram:
1381 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_FUNCTION, Linkage);
1382 case dwarf::DW_TAG_variable:
1383 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE, Linkage);
1384 case dwarf::DW_TAG_enumerator:
1385 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE,
1386 dwarf::GIEL_STATIC);
1388 return dwarf::GIEK_NONE;
1392 /// emitDebugPubNames - Emit visible names into a debug pubnames section.
1394 void DwarfDebug::emitDebugPubNames(bool GnuStyle) {
1395 const MCSection *PSec =
1396 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubNamesSection()
1397 : Asm->getObjFileLowering().getDwarfPubNamesSection();
1399 emitDebugPubSection(GnuStyle, PSec, "Names",
1400 &DwarfCompileUnit::getGlobalNames);
1403 void DwarfDebug::emitDebugPubSection(
1404 bool GnuStyle, const MCSection *PSec, StringRef Name,
1405 const StringMap<const DIE *> &(DwarfCompileUnit::*Accessor)() const) {
1406 for (const auto &NU : CUMap) {
1407 DwarfCompileUnit *TheU = NU.second;
1409 const auto &Globals = (TheU->*Accessor)();
1411 if (Globals.empty())
1414 if (auto *Skeleton = TheU->getSkeleton())
1417 // Start the dwarf pubnames section.
1418 Asm->OutStreamer.SwitchSection(PSec);
1421 Asm->OutStreamer.AddComment("Length of Public " + Name + " Info");
1422 MCSymbol *BeginLabel = Asm->createTempSymbol("pub" + Name + "_begin");
1423 MCSymbol *EndLabel = Asm->createTempSymbol("pub" + Name + "_end");
1424 Asm->EmitLabelDifference(EndLabel, BeginLabel, 4);
1426 Asm->OutStreamer.EmitLabel(BeginLabel);
1428 Asm->OutStreamer.AddComment("DWARF Version");
1429 Asm->EmitInt16(dwarf::DW_PUBNAMES_VERSION);
1431 Asm->OutStreamer.AddComment("Offset of Compilation Unit Info");
1432 Asm->emitSectionOffset(TheU->getLabelBegin());
1434 Asm->OutStreamer.AddComment("Compilation Unit Length");
1435 Asm->EmitInt32(TheU->getLength());
1437 // Emit the pubnames for this compilation unit.
1438 for (const auto &GI : Globals) {
1439 const char *Name = GI.getKeyData();
1440 const DIE *Entity = GI.second;
1442 Asm->OutStreamer.AddComment("DIE offset");
1443 Asm->EmitInt32(Entity->getOffset());
1446 dwarf::PubIndexEntryDescriptor Desc = computeIndexValue(TheU, Entity);
1447 Asm->OutStreamer.AddComment(
1448 Twine("Kind: ") + dwarf::GDBIndexEntryKindString(Desc.Kind) + ", " +
1449 dwarf::GDBIndexEntryLinkageString(Desc.Linkage));
1450 Asm->EmitInt8(Desc.toBits());
1453 Asm->OutStreamer.AddComment("External Name");
1454 Asm->OutStreamer.EmitBytes(StringRef(Name, GI.getKeyLength() + 1));
1457 Asm->OutStreamer.AddComment("End Mark");
1459 Asm->OutStreamer.EmitLabel(EndLabel);
1463 void DwarfDebug::emitDebugPubTypes(bool GnuStyle) {
1464 const MCSection *PSec =
1465 GnuStyle ? Asm->getObjFileLowering().getDwarfGnuPubTypesSection()
1466 : Asm->getObjFileLowering().getDwarfPubTypesSection();
1468 emitDebugPubSection(GnuStyle, PSec, "Types",
1469 &DwarfCompileUnit::getGlobalTypes);
1472 // Emit visible names into a debug str section.
1473 void DwarfDebug::emitDebugStr() {
1474 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1475 Holder.emitStrings(Asm->getObjFileLowering().getDwarfStrSection());
1479 void DwarfDebug::emitDebugLocEntry(ByteStreamer &Streamer,
1480 const DebugLocEntry &Entry) {
1481 auto Comment = Entry.getComments().begin();
1482 auto End = Entry.getComments().end();
1483 for (uint8_t Byte : Entry.getDWARFBytes())
1484 Streamer.EmitInt8(Byte, Comment != End ? *(Comment++) : "");
1487 static void emitDebugLocValue(const AsmPrinter &AP,
1488 const DITypeIdentifierMap &TypeIdentifierMap,
1489 ByteStreamer &Streamer,
1490 const DebugLocEntry::Value &Value,
1491 unsigned PieceOffsetInBits) {
1492 DIVariable DV = Value.getVariable();
1493 DebugLocDwarfExpression DwarfExpr(*AP.MF->getSubtarget().getRegisterInfo(),
1494 AP.getDwarfDebug()->getDwarfVersion(),
1497 if (Value.isInt()) {
1498 DIBasicType BTy(DV.getType().resolve(TypeIdentifierMap));
1499 if (BTy.Verify() && (BTy.getEncoding() == dwarf::DW_ATE_signed ||
1500 BTy.getEncoding() == dwarf::DW_ATE_signed_char))
1501 DwarfExpr.AddSignedConstant(Value.getInt());
1503 DwarfExpr.AddUnsignedConstant(Value.getInt());
1504 } else if (Value.isLocation()) {
1505 MachineLocation Loc = Value.getLoc();
1506 DIExpression Expr = Value.getExpression();
1507 if (!Expr || (Expr.getNumElements() == 0))
1509 AP.EmitDwarfRegOp(Streamer, Loc);
1511 // Complex address entry.
1512 if (Loc.getOffset()) {
1513 DwarfExpr.AddMachineRegIndirect(Loc.getReg(), Loc.getOffset());
1514 DwarfExpr.AddExpression(Expr.begin(), Expr.end(), PieceOffsetInBits);
1516 DwarfExpr.AddMachineRegExpression(Expr, Loc.getReg(),
1520 // else ... ignore constant fp. There is not any good way to
1521 // to represent them here in dwarf.
1526 void DebugLocEntry::finalize(const AsmPrinter &AP,
1527 const DITypeIdentifierMap &TypeIdentifierMap) {
1528 BufferByteStreamer Streamer(DWARFBytes, Comments);
1529 const DebugLocEntry::Value Value = Values[0];
1530 if (Value.isBitPiece()) {
1531 // Emit all pieces that belong to the same variable and range.
1532 assert(std::all_of(Values.begin(), Values.end(), [](DebugLocEntry::Value P) {
1533 return P.isBitPiece();
1534 }) && "all values are expected to be pieces");
1535 assert(std::is_sorted(Values.begin(), Values.end()) &&
1536 "pieces are expected to be sorted");
1538 unsigned Offset = 0;
1539 for (auto Piece : Values) {
1540 DIExpression Expr = Piece.getExpression();
1541 unsigned PieceOffset = Expr.getBitPieceOffset();
1542 unsigned PieceSize = Expr.getBitPieceSize();
1543 assert(Offset <= PieceOffset && "overlapping or duplicate pieces");
1544 if (Offset < PieceOffset) {
1545 // The DWARF spec seriously mandates pieces with no locations for gaps.
1546 DebugLocDwarfExpression Expr(*AP.MF->getSubtarget().getRegisterInfo(),
1547 AP.getDwarfDebug()->getDwarfVersion(),
1549 Expr.AddOpPiece(PieceOffset-Offset, 0);
1550 Offset += PieceOffset-Offset;
1552 Offset += PieceSize;
1555 DIVariable Var = Piece.getVariable();
1556 unsigned VarSize = Var.getSizeInBits(TypeIdentifierMap);
1557 assert(PieceSize+PieceOffset <= VarSize
1558 && "piece is larger than or outside of variable");
1559 assert(PieceSize != VarSize
1560 && "piece covers entire variable");
1562 emitDebugLocValue(AP, TypeIdentifierMap, Streamer, Piece, PieceOffset);
1565 assert(Values.size() == 1 && "only pieces may have >1 value");
1566 emitDebugLocValue(AP, TypeIdentifierMap, Streamer, Value, 0);
1571 void DwarfDebug::emitDebugLocEntryLocation(const DebugLocEntry &Entry) {
1572 Asm->OutStreamer.AddComment("Loc expr size");
1573 MCSymbol *begin = Asm->OutStreamer.getContext().CreateTempSymbol();
1574 MCSymbol *end = Asm->OutStreamer.getContext().CreateTempSymbol();
1575 Asm->EmitLabelDifference(end, begin, 2);
1576 Asm->OutStreamer.EmitLabel(begin);
1578 APByteStreamer Streamer(*Asm);
1579 emitDebugLocEntry(Streamer, Entry);
1581 Asm->OutStreamer.EmitLabel(end);
1584 // Emit locations into the debug loc section.
1585 void DwarfDebug::emitDebugLoc() {
1586 // Start the dwarf loc section.
1587 Asm->OutStreamer.SwitchSection(
1588 Asm->getObjFileLowering().getDwarfLocSection());
1589 unsigned char Size = Asm->getDataLayout().getPointerSize();
1590 for (const auto &DebugLoc : DotDebugLocEntries) {
1591 Asm->OutStreamer.EmitLabel(DebugLoc.Label);
1592 const DwarfCompileUnit *CU = DebugLoc.CU;
1593 for (const auto &Entry : DebugLoc.List) {
1594 // Set up the range. This range is relative to the entry point of the
1595 // compile unit. This is a hard coded 0 for low_pc when we're emitting
1596 // ranges, or the DW_AT_low_pc on the compile unit otherwise.
1597 if (auto *Base = CU->getBaseAddress()) {
1598 Asm->EmitLabelDifference(Entry.getBeginSym(), Base, Size);
1599 Asm->EmitLabelDifference(Entry.getEndSym(), Base, Size);
1601 Asm->OutStreamer.EmitSymbolValue(Entry.getBeginSym(), Size);
1602 Asm->OutStreamer.EmitSymbolValue(Entry.getEndSym(), Size);
1605 emitDebugLocEntryLocation(Entry);
1607 Asm->OutStreamer.EmitIntValue(0, Size);
1608 Asm->OutStreamer.EmitIntValue(0, Size);
1612 void DwarfDebug::emitDebugLocDWO() {
1613 Asm->OutStreamer.SwitchSection(
1614 Asm->getObjFileLowering().getDwarfLocDWOSection());
1615 for (const auto &DebugLoc : DotDebugLocEntries) {
1616 Asm->OutStreamer.EmitLabel(DebugLoc.Label);
1617 for (const auto &Entry : DebugLoc.List) {
1618 // Just always use start_length for now - at least that's one address
1619 // rather than two. We could get fancier and try to, say, reuse an
1620 // address we know we've emitted elsewhere (the start of the function?
1621 // The start of the CU or CU subrange that encloses this range?)
1622 Asm->EmitInt8(dwarf::DW_LLE_start_length_entry);
1623 unsigned idx = AddrPool.getIndex(Entry.getBeginSym());
1624 Asm->EmitULEB128(idx);
1625 Asm->EmitLabelDifference(Entry.getEndSym(), Entry.getBeginSym(), 4);
1627 emitDebugLocEntryLocation(Entry);
1629 Asm->EmitInt8(dwarf::DW_LLE_end_of_list_entry);
1634 const MCSymbol *Start, *End;
1637 // Emit a debug aranges section, containing a CU lookup for any
1638 // address we can tie back to a CU.
1639 void DwarfDebug::emitDebugARanges() {
1640 // Provides a unique id per text section.
1641 MapVector<const MCSection *, SmallVector<SymbolCU, 8>> SectionMap;
1643 // Filter labels by section.
1644 for (const SymbolCU &SCU : ArangeLabels) {
1645 if (SCU.Sym->isInSection()) {
1646 // Make a note of this symbol and it's section.
1647 const MCSection *Section = &SCU.Sym->getSection();
1648 if (!Section->getKind().isMetadata())
1649 SectionMap[Section].push_back(SCU);
1651 // Some symbols (e.g. common/bss on mach-o) can have no section but still
1652 // appear in the output. This sucks as we rely on sections to build
1653 // arange spans. We can do it without, but it's icky.
1654 SectionMap[nullptr].push_back(SCU);
1658 // Add terminating symbols for each section.
1659 for (const auto &I : SectionMap) {
1660 const MCSection *Section = I.first;
1661 MCSymbol *Sym = nullptr;
1664 Sym = Asm->OutStreamer.endSection(Section);
1666 // Insert a final terminator.
1667 SectionMap[Section].push_back(SymbolCU(nullptr, Sym));
1670 DenseMap<DwarfCompileUnit *, std::vector<ArangeSpan>> Spans;
1672 for (auto &I : SectionMap) {
1673 const MCSection *Section = I.first;
1674 SmallVector<SymbolCU, 8> &List = I.second;
1675 if (List.size() < 2)
1678 // If we have no section (e.g. common), just write out
1679 // individual spans for each symbol.
1681 for (const SymbolCU &Cur : List) {
1683 Span.Start = Cur.Sym;
1686 Spans[Cur.CU].push_back(Span);
1691 // Sort the symbols by offset within the section.
1692 std::sort(List.begin(), List.end(),
1693 [&](const SymbolCU &A, const SymbolCU &B) {
1694 unsigned IA = A.Sym ? Asm->OutStreamer.GetSymbolOrder(A.Sym) : 0;
1695 unsigned IB = B.Sym ? Asm->OutStreamer.GetSymbolOrder(B.Sym) : 0;
1697 // Symbols with no order assigned should be placed at the end.
1698 // (e.g. section end labels)
1706 // Build spans between each label.
1707 const MCSymbol *StartSym = List[0].Sym;
1708 for (size_t n = 1, e = List.size(); n < e; n++) {
1709 const SymbolCU &Prev = List[n - 1];
1710 const SymbolCU &Cur = List[n];
1712 // Try and build the longest span we can within the same CU.
1713 if (Cur.CU != Prev.CU) {
1715 Span.Start = StartSym;
1717 Spans[Prev.CU].push_back(Span);
1723 // Start the dwarf aranges section.
1724 Asm->OutStreamer.SwitchSection(
1725 Asm->getObjFileLowering().getDwarfARangesSection());
1727 unsigned PtrSize = Asm->getDataLayout().getPointerSize();
1729 // Build a list of CUs used.
1730 std::vector<DwarfCompileUnit *> CUs;
1731 for (const auto &it : Spans) {
1732 DwarfCompileUnit *CU = it.first;
1736 // Sort the CU list (again, to ensure consistent output order).
1737 std::sort(CUs.begin(), CUs.end(), [](const DwarfUnit *A, const DwarfUnit *B) {
1738 return A->getUniqueID() < B->getUniqueID();
1741 // Emit an arange table for each CU we used.
1742 for (DwarfCompileUnit *CU : CUs) {
1743 std::vector<ArangeSpan> &List = Spans[CU];
1745 // Describe the skeleton CU's offset and length, not the dwo file's.
1746 if (auto *Skel = CU->getSkeleton())
1749 // Emit size of content not including length itself.
1750 unsigned ContentSize =
1751 sizeof(int16_t) + // DWARF ARange version number
1752 sizeof(int32_t) + // Offset of CU in the .debug_info section
1753 sizeof(int8_t) + // Pointer Size (in bytes)
1754 sizeof(int8_t); // Segment Size (in bytes)
1756 unsigned TupleSize = PtrSize * 2;
1758 // 7.20 in the Dwarf specs requires the table to be aligned to a tuple.
1760 OffsetToAlignment(sizeof(int32_t) + ContentSize, TupleSize);
1762 ContentSize += Padding;
1763 ContentSize += (List.size() + 1) * TupleSize;
1765 // For each compile unit, write the list of spans it covers.
1766 Asm->OutStreamer.AddComment("Length of ARange Set");
1767 Asm->EmitInt32(ContentSize);
1768 Asm->OutStreamer.AddComment("DWARF Arange version number");
1769 Asm->EmitInt16(dwarf::DW_ARANGES_VERSION);
1770 Asm->OutStreamer.AddComment("Offset Into Debug Info Section");
1771 Asm->emitSectionOffset(CU->getLabelBegin());
1772 Asm->OutStreamer.AddComment("Address Size (in bytes)");
1773 Asm->EmitInt8(PtrSize);
1774 Asm->OutStreamer.AddComment("Segment Size (in bytes)");
1777 Asm->OutStreamer.EmitFill(Padding, 0xff);
1779 for (const ArangeSpan &Span : List) {
1780 Asm->EmitLabelReference(Span.Start, PtrSize);
1782 // Calculate the size as being from the span start to it's end.
1784 Asm->EmitLabelDifference(Span.End, Span.Start, PtrSize);
1786 // For symbols without an end marker (e.g. common), we
1787 // write a single arange entry containing just that one symbol.
1788 uint64_t Size = SymSize[Span.Start];
1792 Asm->OutStreamer.EmitIntValue(Size, PtrSize);
1796 Asm->OutStreamer.AddComment("ARange terminator");
1797 Asm->OutStreamer.EmitIntValue(0, PtrSize);
1798 Asm->OutStreamer.EmitIntValue(0, PtrSize);
1802 // Emit visible names into a debug ranges section.
1803 void DwarfDebug::emitDebugRanges() {
1804 // Start the dwarf ranges section.
1805 Asm->OutStreamer.SwitchSection(
1806 Asm->getObjFileLowering().getDwarfRangesSection());
1808 // Size for our labels.
1809 unsigned char Size = Asm->getDataLayout().getPointerSize();
1811 // Grab the specific ranges for the compile units in the module.
1812 for (const auto &I : CUMap) {
1813 DwarfCompileUnit *TheCU = I.second;
1815 if (auto *Skel = TheCU->getSkeleton())
1818 // Iterate over the misc ranges for the compile units in the module.
1819 for (const RangeSpanList &List : TheCU->getRangeLists()) {
1820 // Emit our symbol so we can find the beginning of the range.
1821 Asm->OutStreamer.EmitLabel(List.getSym());
1823 for (const RangeSpan &Range : List.getRanges()) {
1824 const MCSymbol *Begin = Range.getStart();
1825 const MCSymbol *End = Range.getEnd();
1826 assert(Begin && "Range without a begin symbol?");
1827 assert(End && "Range without an end symbol?");
1828 if (auto *Base = TheCU->getBaseAddress()) {
1829 Asm->EmitLabelDifference(Begin, Base, Size);
1830 Asm->EmitLabelDifference(End, Base, Size);
1832 Asm->OutStreamer.EmitSymbolValue(Begin, Size);
1833 Asm->OutStreamer.EmitSymbolValue(End, Size);
1837 // And terminate the list with two 0 values.
1838 Asm->OutStreamer.EmitIntValue(0, Size);
1839 Asm->OutStreamer.EmitIntValue(0, Size);
1844 // DWARF5 Experimental Separate Dwarf emitters.
1846 void DwarfDebug::initSkeletonUnit(const DwarfUnit &U, DIE &Die,
1847 std::unique_ptr<DwarfUnit> NewU) {
1848 NewU->addString(Die, dwarf::DW_AT_GNU_dwo_name,
1849 U.getCUNode().getSplitDebugFilename());
1851 if (!CompilationDir.empty())
1852 NewU->addString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
1854 addGnuPubAttributes(*NewU, Die);
1856 SkeletonHolder.addUnit(std::move(NewU));
1859 // This DIE has the following attributes: DW_AT_comp_dir, DW_AT_stmt_list,
1860 // DW_AT_low_pc, DW_AT_high_pc, DW_AT_ranges, DW_AT_dwo_name, DW_AT_dwo_id,
1861 // DW_AT_addr_base, DW_AT_ranges_base.
1862 DwarfCompileUnit &DwarfDebug::constructSkeletonCU(const DwarfCompileUnit &CU) {
1864 auto OwnedUnit = make_unique<DwarfCompileUnit>(
1865 CU.getUniqueID(), CU.getCUNode(), Asm, this, &SkeletonHolder);
1866 DwarfCompileUnit &NewCU = *OwnedUnit;
1867 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoSection());
1869 NewCU.initStmtList();
1871 initSkeletonUnit(CU, NewCU.getUnitDie(), std::move(OwnedUnit));
1876 // Emit the .debug_info.dwo section for separated dwarf. This contains the
1877 // compile units that would normally be in debug_info.
1878 void DwarfDebug::emitDebugInfoDWO() {
1879 assert(useSplitDwarf() && "No split dwarf debug info?");
1880 // Don't emit relocations into the dwo file.
1881 InfoHolder.emitUnits(/* UseOffsets */ true);
1884 // Emit the .debug_abbrev.dwo section for separated dwarf. This contains the
1885 // abbreviations for the .debug_info.dwo section.
1886 void DwarfDebug::emitDebugAbbrevDWO() {
1887 assert(useSplitDwarf() && "No split dwarf?");
1888 InfoHolder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevDWOSection());
1891 void DwarfDebug::emitDebugLineDWO() {
1892 assert(useSplitDwarf() && "No split dwarf?");
1893 Asm->OutStreamer.SwitchSection(
1894 Asm->getObjFileLowering().getDwarfLineDWOSection());
1895 SplitTypeUnitFileTable.Emit(Asm->OutStreamer);
1898 // Emit the .debug_str.dwo section for separated dwarf. This contains the
1899 // string section and is identical in format to traditional .debug_str
1901 void DwarfDebug::emitDebugStrDWO() {
1902 assert(useSplitDwarf() && "No split dwarf?");
1903 const MCSection *OffSec =
1904 Asm->getObjFileLowering().getDwarfStrOffDWOSection();
1905 InfoHolder.emitStrings(Asm->getObjFileLowering().getDwarfStrDWOSection(),
1909 MCDwarfDwoLineTable *DwarfDebug::getDwoLineTable(const DwarfCompileUnit &CU) {
1910 if (!useSplitDwarf())
1913 SplitTypeUnitFileTable.setCompilationDir(CU.getCUNode().getDirectory());
1914 return &SplitTypeUnitFileTable;
1917 static uint64_t makeTypeSignature(StringRef Identifier) {
1919 Hash.update(Identifier);
1920 // ... take the least significant 8 bytes and return those. Our MD5
1921 // implementation always returns its results in little endian, swap bytes
1923 MD5::MD5Result Result;
1925 return support::endian::read64le(Result + 8);
1928 void DwarfDebug::addDwarfTypeUnitType(DwarfCompileUnit &CU,
1929 StringRef Identifier, DIE &RefDie,
1930 DICompositeType CTy) {
1931 // Fast path if we're building some type units and one has already used the
1932 // address pool we know we're going to throw away all this work anyway, so
1933 // don't bother building dependent types.
1934 if (!TypeUnitsUnderConstruction.empty() && AddrPool.hasBeenUsed())
1937 const DwarfTypeUnit *&TU = DwarfTypeUnits[CTy];
1939 CU.addDIETypeSignature(RefDie, *TU);
1943 bool TopLevelType = TypeUnitsUnderConstruction.empty();
1944 AddrPool.resetUsedFlag();
1946 auto OwnedUnit = make_unique<DwarfTypeUnit>(
1947 InfoHolder.getUnits().size() + TypeUnitsUnderConstruction.size(), CU, Asm,
1948 this, &InfoHolder, getDwoLineTable(CU));
1949 DwarfTypeUnit &NewTU = *OwnedUnit;
1950 DIE &UnitDie = NewTU.getUnitDie();
1952 TypeUnitsUnderConstruction.push_back(
1953 std::make_pair(std::move(OwnedUnit), CTy));
1955 NewTU.addUInt(UnitDie, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
1958 uint64_t Signature = makeTypeSignature(Identifier);
1959 NewTU.setTypeSignature(Signature);
1961 if (useSplitDwarf())
1962 NewTU.initSection(Asm->getObjFileLowering().getDwarfTypesDWOSection());
1964 CU.applyStmtList(UnitDie);
1966 Asm->getObjFileLowering().getDwarfTypesSection(Signature));
1969 NewTU.setType(NewTU.createTypeDIE(CTy));
1972 auto TypeUnitsToAdd = std::move(TypeUnitsUnderConstruction);
1973 TypeUnitsUnderConstruction.clear();
1975 // Types referencing entries in the address table cannot be placed in type
1977 if (AddrPool.hasBeenUsed()) {
1979 // Remove all the types built while building this type.
1980 // This is pessimistic as some of these types might not be dependent on
1981 // the type that used an address.
1982 for (const auto &TU : TypeUnitsToAdd)
1983 DwarfTypeUnits.erase(TU.second);
1985 // Construct this type in the CU directly.
1986 // This is inefficient because all the dependent types will be rebuilt
1987 // from scratch, including building them in type units, discovering that
1988 // they depend on addresses, throwing them out and rebuilding them.
1989 CU.constructTypeDIE(RefDie, CTy);
1993 // If the type wasn't dependent on fission addresses, finish adding the type
1994 // and all its dependent types.
1995 for (auto &TU : TypeUnitsToAdd)
1996 InfoHolder.addUnit(std::move(TU.first));
1998 CU.addDIETypeSignature(RefDie, NewTU);
2001 // Accelerator table mutators - add each name along with its companion
2002 // DIE to the proper table while ensuring that the name that we're going
2003 // to reference is in the string table. We do this since the names we
2004 // add may not only be identical to the names in the DIE.
2005 void DwarfDebug::addAccelName(StringRef Name, const DIE &Die) {
2006 if (!useDwarfAccelTables())
2008 AccelNames.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2012 void DwarfDebug::addAccelObjC(StringRef Name, const DIE &Die) {
2013 if (!useDwarfAccelTables())
2015 AccelObjC.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2019 void DwarfDebug::addAccelNamespace(StringRef Name, const DIE &Die) {
2020 if (!useDwarfAccelTables())
2022 AccelNamespace.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2026 void DwarfDebug::addAccelType(StringRef Name, const DIE &Die, char Flags) {
2027 if (!useDwarfAccelTables())
2029 AccelTypes.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),