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) {
975 if (!DL.isUnknown()) {
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(Asm->MF->getFunction()->getContext());
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) &&
1075 !MI.getDebugLoc().isUnknown()) {
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 (!PrologEndLoc.isUnknown()) {
1172 DebugLoc FnStartDL =
1173 PrologEndLoc.getFnDebugLoc(MF->getFunction()->getContext());
1175 // We'd like to list the prologue as "not statements" but GDB behaves
1176 // poorly if we do that. Revisit this with caution/GDB (7.5+) testing.
1177 recordSourceLine(FnStartDL.getLine(), FnStartDL.getCol(),
1178 FnStartDL.getScope(MF->getFunction()->getContext()),
1179 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 // We can't call MCSection::getLabelEndName, as it's only safe to do so
1669 // if we know the section name up-front. For user-created sections, the
1670 // resulting label may not be valid to use as a label. (section names can
1671 // use a greater set of characters on some systems)
1672 Sym = Asm->createTempSymbol("debug_end");
1673 Asm->OutStreamer.SwitchSection(Section);
1674 Asm->OutStreamer.EmitLabel(Sym);
1677 // Insert a final terminator.
1678 SectionMap[Section].push_back(SymbolCU(nullptr, Sym));
1681 DenseMap<DwarfCompileUnit *, std::vector<ArangeSpan>> Spans;
1683 for (auto &I : SectionMap) {
1684 const MCSection *Section = I.first;
1685 SmallVector<SymbolCU, 8> &List = I.second;
1686 if (List.size() < 2)
1689 // If we have no section (e.g. common), just write out
1690 // individual spans for each symbol.
1692 for (const SymbolCU &Cur : List) {
1694 Span.Start = Cur.Sym;
1697 Spans[Cur.CU].push_back(Span);
1702 // Sort the symbols by offset within the section.
1703 std::sort(List.begin(), List.end(),
1704 [&](const SymbolCU &A, const SymbolCU &B) {
1705 unsigned IA = A.Sym ? Asm->OutStreamer.GetSymbolOrder(A.Sym) : 0;
1706 unsigned IB = B.Sym ? Asm->OutStreamer.GetSymbolOrder(B.Sym) : 0;
1708 // Symbols with no order assigned should be placed at the end.
1709 // (e.g. section end labels)
1717 // Build spans between each label.
1718 const MCSymbol *StartSym = List[0].Sym;
1719 for (size_t n = 1, e = List.size(); n < e; n++) {
1720 const SymbolCU &Prev = List[n - 1];
1721 const SymbolCU &Cur = List[n];
1723 // Try and build the longest span we can within the same CU.
1724 if (Cur.CU != Prev.CU) {
1726 Span.Start = StartSym;
1728 Spans[Prev.CU].push_back(Span);
1734 // Start the dwarf aranges section.
1735 Asm->OutStreamer.SwitchSection(
1736 Asm->getObjFileLowering().getDwarfARangesSection());
1738 unsigned PtrSize = Asm->getDataLayout().getPointerSize();
1740 // Build a list of CUs used.
1741 std::vector<DwarfCompileUnit *> CUs;
1742 for (const auto &it : Spans) {
1743 DwarfCompileUnit *CU = it.first;
1747 // Sort the CU list (again, to ensure consistent output order).
1748 std::sort(CUs.begin(), CUs.end(), [](const DwarfUnit *A, const DwarfUnit *B) {
1749 return A->getUniqueID() < B->getUniqueID();
1752 // Emit an arange table for each CU we used.
1753 for (DwarfCompileUnit *CU : CUs) {
1754 std::vector<ArangeSpan> &List = Spans[CU];
1756 // Describe the skeleton CU's offset and length, not the dwo file's.
1757 if (auto *Skel = CU->getSkeleton())
1760 // Emit size of content not including length itself.
1761 unsigned ContentSize =
1762 sizeof(int16_t) + // DWARF ARange version number
1763 sizeof(int32_t) + // Offset of CU in the .debug_info section
1764 sizeof(int8_t) + // Pointer Size (in bytes)
1765 sizeof(int8_t); // Segment Size (in bytes)
1767 unsigned TupleSize = PtrSize * 2;
1769 // 7.20 in the Dwarf specs requires the table to be aligned to a tuple.
1771 OffsetToAlignment(sizeof(int32_t) + ContentSize, TupleSize);
1773 ContentSize += Padding;
1774 ContentSize += (List.size() + 1) * TupleSize;
1776 // For each compile unit, write the list of spans it covers.
1777 Asm->OutStreamer.AddComment("Length of ARange Set");
1778 Asm->EmitInt32(ContentSize);
1779 Asm->OutStreamer.AddComment("DWARF Arange version number");
1780 Asm->EmitInt16(dwarf::DW_ARANGES_VERSION);
1781 Asm->OutStreamer.AddComment("Offset Into Debug Info Section");
1782 Asm->emitSectionOffset(CU->getLabelBegin());
1783 Asm->OutStreamer.AddComment("Address Size (in bytes)");
1784 Asm->EmitInt8(PtrSize);
1785 Asm->OutStreamer.AddComment("Segment Size (in bytes)");
1788 Asm->OutStreamer.EmitFill(Padding, 0xff);
1790 for (const ArangeSpan &Span : List) {
1791 Asm->EmitLabelReference(Span.Start, PtrSize);
1793 // Calculate the size as being from the span start to it's end.
1795 Asm->EmitLabelDifference(Span.End, Span.Start, PtrSize);
1797 // For symbols without an end marker (e.g. common), we
1798 // write a single arange entry containing just that one symbol.
1799 uint64_t Size = SymSize[Span.Start];
1803 Asm->OutStreamer.EmitIntValue(Size, PtrSize);
1807 Asm->OutStreamer.AddComment("ARange terminator");
1808 Asm->OutStreamer.EmitIntValue(0, PtrSize);
1809 Asm->OutStreamer.EmitIntValue(0, PtrSize);
1813 // Emit visible names into a debug ranges section.
1814 void DwarfDebug::emitDebugRanges() {
1815 // Start the dwarf ranges section.
1816 Asm->OutStreamer.SwitchSection(
1817 Asm->getObjFileLowering().getDwarfRangesSection());
1819 // Size for our labels.
1820 unsigned char Size = Asm->getDataLayout().getPointerSize();
1822 // Grab the specific ranges for the compile units in the module.
1823 for (const auto &I : CUMap) {
1824 DwarfCompileUnit *TheCU = I.second;
1826 if (auto *Skel = TheCU->getSkeleton())
1829 // Iterate over the misc ranges for the compile units in the module.
1830 for (const RangeSpanList &List : TheCU->getRangeLists()) {
1831 // Emit our symbol so we can find the beginning of the range.
1832 Asm->OutStreamer.EmitLabel(List.getSym());
1834 for (const RangeSpan &Range : List.getRanges()) {
1835 const MCSymbol *Begin = Range.getStart();
1836 const MCSymbol *End = Range.getEnd();
1837 assert(Begin && "Range without a begin symbol?");
1838 assert(End && "Range without an end symbol?");
1839 if (auto *Base = TheCU->getBaseAddress()) {
1840 Asm->EmitLabelDifference(Begin, Base, Size);
1841 Asm->EmitLabelDifference(End, Base, Size);
1843 Asm->OutStreamer.EmitSymbolValue(Begin, Size);
1844 Asm->OutStreamer.EmitSymbolValue(End, Size);
1848 // And terminate the list with two 0 values.
1849 Asm->OutStreamer.EmitIntValue(0, Size);
1850 Asm->OutStreamer.EmitIntValue(0, Size);
1855 // DWARF5 Experimental Separate Dwarf emitters.
1857 void DwarfDebug::initSkeletonUnit(const DwarfUnit &U, DIE &Die,
1858 std::unique_ptr<DwarfUnit> NewU) {
1859 NewU->addString(Die, dwarf::DW_AT_GNU_dwo_name,
1860 U.getCUNode().getSplitDebugFilename());
1862 if (!CompilationDir.empty())
1863 NewU->addString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
1865 addGnuPubAttributes(*NewU, Die);
1867 SkeletonHolder.addUnit(std::move(NewU));
1870 // This DIE has the following attributes: DW_AT_comp_dir, DW_AT_stmt_list,
1871 // DW_AT_low_pc, DW_AT_high_pc, DW_AT_ranges, DW_AT_dwo_name, DW_AT_dwo_id,
1872 // DW_AT_addr_base, DW_AT_ranges_base.
1873 DwarfCompileUnit &DwarfDebug::constructSkeletonCU(const DwarfCompileUnit &CU) {
1875 auto OwnedUnit = make_unique<DwarfCompileUnit>(
1876 CU.getUniqueID(), CU.getCUNode(), Asm, this, &SkeletonHolder);
1877 DwarfCompileUnit &NewCU = *OwnedUnit;
1878 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoSection());
1880 NewCU.initStmtList();
1882 initSkeletonUnit(CU, NewCU.getUnitDie(), std::move(OwnedUnit));
1887 // Emit the .debug_info.dwo section for separated dwarf. This contains the
1888 // compile units that would normally be in debug_info.
1889 void DwarfDebug::emitDebugInfoDWO() {
1890 assert(useSplitDwarf() && "No split dwarf debug info?");
1891 // Don't emit relocations into the dwo file.
1892 InfoHolder.emitUnits(/* UseOffsets */ true);
1895 // Emit the .debug_abbrev.dwo section for separated dwarf. This contains the
1896 // abbreviations for the .debug_info.dwo section.
1897 void DwarfDebug::emitDebugAbbrevDWO() {
1898 assert(useSplitDwarf() && "No split dwarf?");
1899 InfoHolder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevDWOSection());
1902 void DwarfDebug::emitDebugLineDWO() {
1903 assert(useSplitDwarf() && "No split dwarf?");
1904 Asm->OutStreamer.SwitchSection(
1905 Asm->getObjFileLowering().getDwarfLineDWOSection());
1906 SplitTypeUnitFileTable.Emit(Asm->OutStreamer);
1909 // Emit the .debug_str.dwo section for separated dwarf. This contains the
1910 // string section and is identical in format to traditional .debug_str
1912 void DwarfDebug::emitDebugStrDWO() {
1913 assert(useSplitDwarf() && "No split dwarf?");
1914 const MCSection *OffSec =
1915 Asm->getObjFileLowering().getDwarfStrOffDWOSection();
1916 InfoHolder.emitStrings(Asm->getObjFileLowering().getDwarfStrDWOSection(),
1920 MCDwarfDwoLineTable *DwarfDebug::getDwoLineTable(const DwarfCompileUnit &CU) {
1921 if (!useSplitDwarf())
1924 SplitTypeUnitFileTable.setCompilationDir(CU.getCUNode().getDirectory());
1925 return &SplitTypeUnitFileTable;
1928 static uint64_t makeTypeSignature(StringRef Identifier) {
1930 Hash.update(Identifier);
1931 // ... take the least significant 8 bytes and return those. Our MD5
1932 // implementation always returns its results in little endian, swap bytes
1934 MD5::MD5Result Result;
1936 return support::endian::read64le(Result + 8);
1939 void DwarfDebug::addDwarfTypeUnitType(DwarfCompileUnit &CU,
1940 StringRef Identifier, DIE &RefDie,
1941 DICompositeType CTy) {
1942 // Fast path if we're building some type units and one has already used the
1943 // address pool we know we're going to throw away all this work anyway, so
1944 // don't bother building dependent types.
1945 if (!TypeUnitsUnderConstruction.empty() && AddrPool.hasBeenUsed())
1948 const DwarfTypeUnit *&TU = DwarfTypeUnits[CTy];
1950 CU.addDIETypeSignature(RefDie, *TU);
1954 bool TopLevelType = TypeUnitsUnderConstruction.empty();
1955 AddrPool.resetUsedFlag();
1957 auto OwnedUnit = make_unique<DwarfTypeUnit>(
1958 InfoHolder.getUnits().size() + TypeUnitsUnderConstruction.size(), CU, Asm,
1959 this, &InfoHolder, getDwoLineTable(CU));
1960 DwarfTypeUnit &NewTU = *OwnedUnit;
1961 DIE &UnitDie = NewTU.getUnitDie();
1963 TypeUnitsUnderConstruction.push_back(
1964 std::make_pair(std::move(OwnedUnit), CTy));
1966 NewTU.addUInt(UnitDie, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
1969 uint64_t Signature = makeTypeSignature(Identifier);
1970 NewTU.setTypeSignature(Signature);
1972 if (useSplitDwarf())
1973 NewTU.initSection(Asm->getObjFileLowering().getDwarfTypesDWOSection());
1975 CU.applyStmtList(UnitDie);
1977 Asm->getObjFileLowering().getDwarfTypesSection(Signature));
1980 NewTU.setType(NewTU.createTypeDIE(CTy));
1983 auto TypeUnitsToAdd = std::move(TypeUnitsUnderConstruction);
1984 TypeUnitsUnderConstruction.clear();
1986 // Types referencing entries in the address table cannot be placed in type
1988 if (AddrPool.hasBeenUsed()) {
1990 // Remove all the types built while building this type.
1991 // This is pessimistic as some of these types might not be dependent on
1992 // the type that used an address.
1993 for (const auto &TU : TypeUnitsToAdd)
1994 DwarfTypeUnits.erase(TU.second);
1996 // Construct this type in the CU directly.
1997 // This is inefficient because all the dependent types will be rebuilt
1998 // from scratch, including building them in type units, discovering that
1999 // they depend on addresses, throwing them out and rebuilding them.
2000 CU.constructTypeDIE(RefDie, CTy);
2004 // If the type wasn't dependent on fission addresses, finish adding the type
2005 // and all its dependent types.
2006 for (auto &TU : TypeUnitsToAdd)
2007 InfoHolder.addUnit(std::move(TU.first));
2009 CU.addDIETypeSignature(RefDie, NewTU);
2012 // Accelerator table mutators - add each name along with its companion
2013 // DIE to the proper table while ensuring that the name that we're going
2014 // to reference is in the string table. We do this since the names we
2015 // add may not only be identical to the names in the DIE.
2016 void DwarfDebug::addAccelName(StringRef Name, const DIE &Die) {
2017 if (!useDwarfAccelTables())
2019 AccelNames.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2023 void DwarfDebug::addAccelObjC(StringRef Name, const DIE &Die) {
2024 if (!useDwarfAccelTables())
2026 AccelObjC.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2030 void DwarfDebug::addAccelNamespace(StringRef Name, const DIE &Die) {
2031 if (!useDwarfAccelTables())
2033 AccelNamespace.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),
2037 void DwarfDebug::addAccelType(StringRef Name, const DIE &Die, char Flags) {
2038 if (!useDwarfAccelTables())
2040 AccelTypes.AddName(Name, InfoHolder.getStringPool().getSymbol(*Asm, Name),