1 //===-- llvm/CodeGen/DwarfDebug.cpp - Dwarf Debug Framework ---------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file contains support for writing dwarf debug info into asm files.
12 //===----------------------------------------------------------------------===//
14 #include "DwarfDebug.h"
15 #include "ByteStreamer.h"
17 #include "DebugLocEntry.h"
18 #include "DwarfCompileUnit.h"
19 #include "DwarfExpression.h"
20 #include "DwarfUnit.h"
21 #include "llvm/ADT/STLExtras.h"
22 #include "llvm/ADT/Statistic.h"
23 #include "llvm/ADT/StringExtras.h"
24 #include "llvm/ADT/Triple.h"
25 #include "llvm/CodeGen/DIE.h"
26 #include "llvm/CodeGen/MachineFunction.h"
27 #include "llvm/CodeGen/MachineModuleInfo.h"
28 #include "llvm/IR/Constants.h"
29 #include "llvm/IR/DIBuilder.h"
30 #include "llvm/IR/DataLayout.h"
31 #include "llvm/IR/DebugInfo.h"
32 #include "llvm/IR/Instructions.h"
33 #include "llvm/IR/Module.h"
34 #include "llvm/IR/ValueHandle.h"
35 #include "llvm/MC/MCAsmInfo.h"
36 #include "llvm/MC/MCDwarf.h"
37 #include "llvm/MC/MCSection.h"
38 #include "llvm/MC/MCStreamer.h"
39 #include "llvm/MC/MCSymbol.h"
40 #include "llvm/Support/CommandLine.h"
41 #include "llvm/Support/Debug.h"
42 #include "llvm/Support/Dwarf.h"
43 #include "llvm/Support/Endian.h"
44 #include "llvm/Support/ErrorHandling.h"
45 #include "llvm/Support/FormattedStream.h"
46 #include "llvm/Support/LEB128.h"
47 #include "llvm/Support/MD5.h"
48 #include "llvm/Support/Path.h"
49 #include "llvm/Support/Timer.h"
50 #include "llvm/Support/raw_ostream.h"
51 #include "llvm/Target/TargetFrameLowering.h"
52 #include "llvm/Target/TargetLoweringObjectFile.h"
53 #include "llvm/Target/TargetMachine.h"
54 #include "llvm/Target/TargetOptions.h"
55 #include "llvm/Target/TargetRegisterInfo.h"
56 #include "llvm/Target/TargetSubtargetInfo.h"
59 #define DEBUG_TYPE "dwarfdebug"
62 DisableDebugInfoPrinting("disable-debug-info-print", cl::Hidden,
63 cl::desc("Disable debug info printing"));
65 static cl::opt<bool> UnknownLocations(
66 "use-unknown-locations", cl::Hidden,
67 cl::desc("Make an absence of debug location information explicit."),
71 GenerateGnuPubSections("generate-gnu-dwarf-pub-sections", cl::Hidden,
72 cl::desc("Generate GNU-style pubnames and pubtypes"),
75 static cl::opt<bool> GenerateARangeSection("generate-arange-section",
77 cl::desc("Generate dwarf aranges"),
80 static cl::opt<DebuggerKind>
81 DebuggerTuningOpt("debugger-tune",
82 cl::desc("Tune debug info for a particular debugger"),
83 cl::init(DebuggerKind::Default),
85 clEnumValN(DebuggerKind::GDB, "gdb", "gdb"),
86 clEnumValN(DebuggerKind::LLDB, "lldb", "lldb"),
87 clEnumValN(DebuggerKind::SCE, "sce",
88 "SCE targets (e.g. PS4)"),
92 enum DefaultOnOff { Default, Enable, Disable };
95 static cl::opt<DefaultOnOff>
96 DwarfAccelTables("dwarf-accel-tables", cl::Hidden,
97 cl::desc("Output prototype dwarf accelerator tables."),
98 cl::values(clEnumVal(Default, "Default for platform"),
99 clEnumVal(Enable, "Enabled"),
100 clEnumVal(Disable, "Disabled"), clEnumValEnd),
103 static cl::opt<DefaultOnOff>
104 SplitDwarf("split-dwarf", cl::Hidden,
105 cl::desc("Output DWARF5 split debug info."),
106 cl::values(clEnumVal(Default, "Default for platform"),
107 clEnumVal(Enable, "Enabled"),
108 clEnumVal(Disable, "Disabled"), clEnumValEnd),
111 static cl::opt<DefaultOnOff>
112 DwarfPubSections("generate-dwarf-pub-sections", cl::Hidden,
113 cl::desc("Generate DWARF pubnames and pubtypes sections"),
114 cl::values(clEnumVal(Default, "Default for platform"),
115 clEnumVal(Enable, "Enabled"),
116 clEnumVal(Disable, "Disabled"), clEnumValEnd),
119 static cl::opt<DefaultOnOff>
120 DwarfLinkageNames("dwarf-linkage-names", cl::Hidden,
121 cl::desc("Emit DWARF linkage-name attributes."),
122 cl::values(clEnumVal(Default, "Default for platform"),
123 clEnumVal(Enable, "Enabled"),
124 clEnumVal(Disable, "Disabled"), clEnumValEnd),
127 static const char *const DWARFGroupName = "DWARF Emission";
128 static const char *const DbgTimerName = "DWARF Debug Writer";
130 void DebugLocDwarfExpression::EmitOp(uint8_t Op, const char *Comment) {
132 Op, Comment ? Twine(Comment) + " " + dwarf::OperationEncodingString(Op)
133 : dwarf::OperationEncodingString(Op));
136 void DebugLocDwarfExpression::EmitSigned(int64_t Value) {
137 BS.EmitSLEB128(Value, Twine(Value));
140 void DebugLocDwarfExpression::EmitUnsigned(uint64_t Value) {
141 BS.EmitULEB128(Value, Twine(Value));
144 bool DebugLocDwarfExpression::isFrameRegister(unsigned MachineReg) {
145 // This information is not available while emitting .debug_loc entries.
149 //===----------------------------------------------------------------------===//
151 /// resolve - Look in the DwarfDebug map for the MDNode that
152 /// corresponds to the reference.
153 template <typename T> T *DbgVariable::resolve(TypedDINodeRef<T> Ref) const {
154 return DD->resolve(Ref);
157 bool DbgVariable::isBlockByrefVariable() const {
158 assert(Var && "Invalid complex DbgVariable!");
159 return Var->getType()
160 .resolve(DD->getTypeIdentifierMap())
161 ->isBlockByrefStruct();
164 const DIType *DbgVariable::getType() const {
165 DIType *Ty = Var->getType().resolve(DD->getTypeIdentifierMap());
166 // FIXME: isBlockByrefVariable should be reformulated in terms of complex
167 // addresses instead.
168 if (Ty->isBlockByrefStruct()) {
169 /* Byref variables, in Blocks, are declared by the programmer as
170 "SomeType VarName;", but the compiler creates a
171 __Block_byref_x_VarName struct, and gives the variable VarName
172 either the struct, or a pointer to the struct, as its type. This
173 is necessary for various behind-the-scenes things the compiler
174 needs to do with by-reference variables in blocks.
176 However, as far as the original *programmer* is concerned, the
177 variable should still have type 'SomeType', as originally declared.
179 The following function dives into the __Block_byref_x_VarName
180 struct to find the original type of the variable. This will be
181 passed back to the code generating the type for the Debug
182 Information Entry for the variable 'VarName'. 'VarName' will then
183 have the original type 'SomeType' in its debug information.
185 The original type 'SomeType' will be the type of the field named
186 'VarName' inside the __Block_byref_x_VarName struct.
188 NOTE: In order for this to not completely fail on the debugger
189 side, the Debug Information Entry for the variable VarName needs to
190 have a DW_AT_location that tells the debugger how to unwind through
191 the pointers and __Block_byref_x_VarName struct to find the actual
192 value of the variable. The function addBlockByrefType does this. */
193 DIType *subType = Ty;
194 uint16_t tag = Ty->getTag();
196 if (tag == dwarf::DW_TAG_pointer_type)
197 subType = resolve(cast<DIDerivedType>(Ty)->getBaseType());
199 auto Elements = cast<DICompositeType>(subType)->getElements();
200 for (unsigned i = 0, N = Elements.size(); i < N; ++i) {
201 auto *DT = cast<DIDerivedType>(Elements[i]);
202 if (getName() == DT->getName())
203 return resolve(DT->getBaseType());
209 static LLVM_CONSTEXPR DwarfAccelTable::Atom TypeAtoms[] = {
210 DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset, dwarf::DW_FORM_data4),
211 DwarfAccelTable::Atom(dwarf::DW_ATOM_die_tag, dwarf::DW_FORM_data2),
212 DwarfAccelTable::Atom(dwarf::DW_ATOM_type_flags, dwarf::DW_FORM_data1)};
214 DwarfDebug::DwarfDebug(AsmPrinter *A, Module *M)
215 : Asm(A), MMI(Asm->MMI), DebugLocs(A->OutStreamer->isVerboseAsm()),
216 PrevLabel(nullptr), InfoHolder(A, "info_string", DIEValueAllocator),
217 SkeletonHolder(A, "skel_string", DIEValueAllocator),
218 IsDarwin(Triple(A->getTargetTriple()).isOSDarwin()),
219 AccelNames(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
220 dwarf::DW_FORM_data4)),
221 AccelObjC(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
222 dwarf::DW_FORM_data4)),
223 AccelNamespace(DwarfAccelTable::Atom(dwarf::DW_ATOM_die_offset,
224 dwarf::DW_FORM_data4)),
225 AccelTypes(TypeAtoms), DebuggerTuning(DebuggerKind::Default) {
229 Triple TT(Asm->getTargetTriple());
231 // Make sure we know our "debugger tuning." The command-line option takes
232 // precedence; fall back to triple-based defaults.
233 if (DebuggerTuningOpt != DebuggerKind::Default)
234 DebuggerTuning = DebuggerTuningOpt;
235 else if (IsDarwin || TT.isOSFreeBSD())
236 DebuggerTuning = DebuggerKind::LLDB;
237 else if (TT.isPS4CPU())
238 DebuggerTuning = DebuggerKind::SCE;
240 DebuggerTuning = DebuggerKind::GDB;
242 // Turn on accelerator tables for LLDB by default.
243 if (DwarfAccelTables == Default)
244 HasDwarfAccelTables = tuneForLLDB();
246 HasDwarfAccelTables = DwarfAccelTables == Enable;
248 // Handle split DWARF. Off by default for now.
249 if (SplitDwarf == Default)
250 HasSplitDwarf = false;
252 HasSplitDwarf = SplitDwarf == Enable;
254 // Pubnames/pubtypes on by default for GDB.
255 if (DwarfPubSections == Default)
256 HasDwarfPubSections = tuneForGDB();
258 HasDwarfPubSections = DwarfPubSections == Enable;
260 // SCE does not use linkage names.
261 if (DwarfLinkageNames == Default)
262 UseLinkageNames = !tuneForSCE();
264 UseLinkageNames = DwarfLinkageNames == Enable;
266 unsigned DwarfVersionNumber = Asm->TM.Options.MCOptions.DwarfVersion;
267 DwarfVersion = DwarfVersionNumber ? DwarfVersionNumber
268 : MMI->getModule()->getDwarfVersion();
269 // Use dwarf 4 by default if nothing is requested.
270 DwarfVersion = DwarfVersion ? DwarfVersion : dwarf::DWARF_VERSION;
272 // Work around a GDB bug. GDB doesn't support the standard opcode;
273 // SCE doesn't support GNU's; LLDB prefers the standard opcode, which
274 // is defined as of DWARF 3.
275 // See GDB bug 11616 - DW_OP_form_tls_address is unimplemented
276 // https://sourceware.org/bugzilla/show_bug.cgi?id=11616
277 UseGNUTLSOpcode = tuneForGDB() || DwarfVersion < 3;
279 Asm->OutStreamer->getContext().setDwarfVersion(DwarfVersion);
282 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
287 // Define out of line so we don't have to include DwarfUnit.h in DwarfDebug.h.
288 DwarfDebug::~DwarfDebug() { }
290 static bool isObjCClass(StringRef Name) {
291 return Name.startswith("+") || Name.startswith("-");
294 static bool hasObjCCategory(StringRef Name) {
295 if (!isObjCClass(Name))
298 return Name.find(") ") != StringRef::npos;
301 static void getObjCClassCategory(StringRef In, StringRef &Class,
302 StringRef &Category) {
303 if (!hasObjCCategory(In)) {
304 Class = In.slice(In.find('[') + 1, In.find(' '));
309 Class = In.slice(In.find('[') + 1, In.find('('));
310 Category = In.slice(In.find('[') + 1, In.find(' '));
314 static StringRef getObjCMethodName(StringRef In) {
315 return In.slice(In.find(' ') + 1, In.find(']'));
318 // Add the various names to the Dwarf accelerator table names.
319 // TODO: Determine whether or not we should add names for programs
320 // that do not have a DW_AT_name or DW_AT_linkage_name field - this
321 // is only slightly different than the lookup of non-standard ObjC names.
322 void DwarfDebug::addSubprogramNames(const DISubprogram *SP, DIE &Die) {
323 if (!SP->isDefinition())
325 addAccelName(SP->getName(), Die);
327 // If the linkage name is different than the name, go ahead and output
328 // that as well into the name table.
329 if (SP->getLinkageName() != "" && SP->getName() != SP->getLinkageName())
330 addAccelName(SP->getLinkageName(), Die);
332 // If this is an Objective-C selector name add it to the ObjC accelerator
334 if (isObjCClass(SP->getName())) {
335 StringRef Class, Category;
336 getObjCClassCategory(SP->getName(), Class, Category);
337 addAccelObjC(Class, Die);
339 addAccelObjC(Category, Die);
340 // Also add the base method name to the name table.
341 addAccelName(getObjCMethodName(SP->getName()), Die);
345 /// Check whether we should create a DIE for the given Scope, return true
346 /// if we don't create a DIE (the corresponding DIE is null).
347 bool DwarfDebug::isLexicalScopeDIENull(LexicalScope *Scope) {
348 if (Scope->isAbstractScope())
351 // We don't create a DIE if there is no Range.
352 const SmallVectorImpl<InsnRange> &Ranges = Scope->getRanges();
356 if (Ranges.size() > 1)
359 // We don't create a DIE if we have a single Range and the end label
361 return !getLabelAfterInsn(Ranges.front().second);
364 template <typename Func> void forBothCUs(DwarfCompileUnit &CU, Func F) {
366 if (auto *SkelCU = CU.getSkeleton())
370 void DwarfDebug::constructAbstractSubprogramScopeDIE(LexicalScope *Scope) {
371 assert(Scope && Scope->getScopeNode());
372 assert(Scope->isAbstractScope());
373 assert(!Scope->getInlinedAt());
375 const MDNode *SP = Scope->getScopeNode();
377 ProcessedSPNodes.insert(SP);
379 // Find the subprogram's DwarfCompileUnit in the SPMap in case the subprogram
380 // was inlined from another compile unit.
381 auto &CU = SPMap[SP];
382 forBothCUs(*CU, [&](DwarfCompileUnit &CU) {
383 CU.constructAbstractSubprogramScopeDIE(Scope);
387 void DwarfDebug::addGnuPubAttributes(DwarfUnit &U, DIE &D) const {
388 if (!GenerateGnuPubSections)
391 U.addFlag(D, dwarf::DW_AT_GNU_pubnames);
394 // Create new DwarfCompileUnit for the given metadata node with tag
395 // DW_TAG_compile_unit.
397 DwarfDebug::constructDwarfCompileUnit(const DICompileUnit *DIUnit) {
398 StringRef FN = DIUnit->getFilename();
399 CompilationDir = DIUnit->getDirectory();
401 auto OwnedUnit = make_unique<DwarfCompileUnit>(
402 InfoHolder.getUnits().size(), DIUnit, Asm, this, &InfoHolder);
403 DwarfCompileUnit &NewCU = *OwnedUnit;
404 DIE &Die = NewCU.getUnitDie();
405 InfoHolder.addUnit(std::move(OwnedUnit));
407 NewCU.setSkeleton(constructSkeletonCU(NewCU));
409 // LTO with assembly output shares a single line table amongst multiple CUs.
410 // To avoid the compilation directory being ambiguous, let the line table
411 // explicitly describe the directory of all files, never relying on the
412 // compilation directory.
413 if (!Asm->OutStreamer->hasRawTextSupport() || SingleCU)
414 Asm->OutStreamer->getContext().setMCLineTableCompilationDir(
415 NewCU.getUniqueID(), CompilationDir);
417 NewCU.addString(Die, dwarf::DW_AT_producer, DIUnit->getProducer());
418 NewCU.addUInt(Die, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
419 DIUnit->getSourceLanguage());
420 NewCU.addString(Die, dwarf::DW_AT_name, FN);
422 if (!useSplitDwarf()) {
423 NewCU.initStmtList();
425 // If we're using split dwarf the compilation dir is going to be in the
426 // skeleton CU and so we don't need to duplicate it here.
427 if (!CompilationDir.empty())
428 NewCU.addString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
430 addGnuPubAttributes(NewCU, Die);
433 if (DIUnit->isOptimized())
434 NewCU.addFlag(Die, dwarf::DW_AT_APPLE_optimized);
436 StringRef Flags = DIUnit->getFlags();
438 NewCU.addString(Die, dwarf::DW_AT_APPLE_flags, Flags);
440 if (unsigned RVer = DIUnit->getRuntimeVersion())
441 NewCU.addUInt(Die, dwarf::DW_AT_APPLE_major_runtime_vers,
442 dwarf::DW_FORM_data1, RVer);
445 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoDWOSection());
447 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoSection());
449 if (DIUnit->getDWOId()) {
450 // This CU is either a clang module DWO or a skeleton CU.
451 NewCU.addUInt(Die, dwarf::DW_AT_GNU_dwo_id, dwarf::DW_FORM_data8,
453 if (!DIUnit->getSplitDebugFilename().empty())
454 // This is a prefabricated skeleton CU.
455 NewCU.addString(Die, dwarf::DW_AT_GNU_dwo_name,
456 DIUnit->getSplitDebugFilename());
459 CUMap.insert(std::make_pair(DIUnit, &NewCU));
460 CUDieMap.insert(std::make_pair(&Die, &NewCU));
464 void DwarfDebug::constructAndAddImportedEntityDIE(DwarfCompileUnit &TheCU,
465 const DIImportedEntity *N) {
466 if (DIE *D = TheCU.getOrCreateContextDIE(N->getScope()))
467 D->addChild(TheCU.constructImportedEntityDIE(N));
470 // Emit all Dwarf sections that should come prior to the content. Create
471 // global DIEs and emit initial debug info sections. This is invoked by
472 // the target AsmPrinter.
473 void DwarfDebug::beginModule() {
474 if (DisableDebugInfoPrinting)
477 const Module *M = MMI->getModule();
479 NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
482 TypeIdentifierMap = generateDITypeIdentifierMap(CU_Nodes);
484 SingleCU = CU_Nodes->getNumOperands() == 1;
486 for (MDNode *N : CU_Nodes->operands()) {
487 auto *CUNode = cast<DICompileUnit>(N);
488 DwarfCompileUnit &CU = constructDwarfCompileUnit(CUNode);
489 for (auto *IE : CUNode->getImportedEntities())
490 CU.addImportedEntity(IE);
491 for (auto *GV : CUNode->getGlobalVariables())
492 CU.getOrCreateGlobalVariableDIE(GV);
493 for (auto *SP : CUNode->getSubprograms())
494 SPMap.insert(std::make_pair(SP, &CU));
495 for (auto *Ty : CUNode->getEnumTypes()) {
496 // The enum types array by design contains pointers to
497 // MDNodes rather than DIRefs. Unique them here.
498 CU.getOrCreateTypeDIE(cast<DIType>(resolve(Ty->getRef())));
500 for (auto *Ty : CUNode->getRetainedTypes()) {
501 // The retained types array by design contains pointers to
502 // MDNodes rather than DIRefs. Unique them here.
503 DIType *RT = cast<DIType>(resolve(Ty->getRef()));
504 if (!RT->isExternalTypeRef())
505 // There is no point in force-emitting a forward declaration.
506 CU.getOrCreateTypeDIE(RT);
508 // Emit imported_modules last so that the relevant context is already
510 for (auto *IE : CUNode->getImportedEntities())
511 constructAndAddImportedEntityDIE(CU, IE);
514 // Tell MMI that we have debug info.
515 MMI->setDebugInfoAvailability(true);
518 void DwarfDebug::finishVariableDefinitions() {
519 for (const auto &Var : ConcreteVariables) {
520 DIE *VariableDie = Var->getDIE();
522 // FIXME: Consider the time-space tradeoff of just storing the unit pointer
523 // in the ConcreteVariables list, rather than looking it up again here.
524 // DIE::getUnit isn't simple - it walks parent pointers, etc.
525 DwarfCompileUnit *Unit = lookupUnit(VariableDie->getUnit());
527 DbgVariable *AbsVar = getExistingAbstractVariable(
528 InlinedVariable(Var->getVariable(), Var->getInlinedAt()));
529 if (AbsVar && AbsVar->getDIE()) {
530 Unit->addDIEEntry(*VariableDie, dwarf::DW_AT_abstract_origin,
533 Unit->applyVariableAttributes(*Var, *VariableDie);
537 void DwarfDebug::finishSubprogramDefinitions() {
538 for (const auto &P : SPMap)
539 forBothCUs(*P.second, [&](DwarfCompileUnit &CU) {
540 CU.finishSubprogramDefinition(cast<DISubprogram>(P.first));
545 // Collect info for variables that were optimized out.
546 void DwarfDebug::collectDeadVariables() {
547 const Module *M = MMI->getModule();
549 if (NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu")) {
550 for (MDNode *N : CU_Nodes->operands()) {
551 auto *TheCU = cast<DICompileUnit>(N);
552 // Construct subprogram DIE and add variables DIEs.
553 DwarfCompileUnit *SPCU =
554 static_cast<DwarfCompileUnit *>(CUMap.lookup(TheCU));
555 assert(SPCU && "Unable to find Compile Unit!");
556 for (auto *SP : TheCU->getSubprograms()) {
557 if (ProcessedSPNodes.count(SP) != 0)
559 SPCU->collectDeadVariables(SP);
565 void DwarfDebug::finalizeModuleInfo() {
566 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
568 finishSubprogramDefinitions();
570 finishVariableDefinitions();
572 // Collect info for variables that were optimized out.
573 collectDeadVariables();
575 // Handle anything that needs to be done on a per-unit basis after
576 // all other generation.
577 for (const auto &P : CUMap) {
578 auto &TheCU = *P.second;
579 // Emit DW_AT_containing_type attribute to connect types with their
580 // vtable holding type.
581 TheCU.constructContainingTypeDIEs();
583 // Add CU specific attributes if we need to add any.
584 // If we're splitting the dwarf out now that we've got the entire
585 // CU then add the dwo id to it.
586 auto *SkCU = TheCU.getSkeleton();
587 if (useSplitDwarf()) {
588 // Emit a unique identifier for this CU.
589 uint64_t ID = DIEHash(Asm).computeCUSignature(TheCU.getUnitDie());
590 TheCU.addUInt(TheCU.getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
591 dwarf::DW_FORM_data8, ID);
592 SkCU->addUInt(SkCU->getUnitDie(), dwarf::DW_AT_GNU_dwo_id,
593 dwarf::DW_FORM_data8, ID);
595 // We don't keep track of which addresses are used in which CU so this
596 // is a bit pessimistic under LTO.
597 if (!AddrPool.isEmpty()) {
598 const MCSymbol *Sym = TLOF.getDwarfAddrSection()->getBeginSymbol();
599 SkCU->addSectionLabel(SkCU->getUnitDie(), dwarf::DW_AT_GNU_addr_base,
602 if (!SkCU->getRangeLists().empty()) {
603 const MCSymbol *Sym = TLOF.getDwarfRangesSection()->getBeginSymbol();
604 SkCU->addSectionLabel(SkCU->getUnitDie(), dwarf::DW_AT_GNU_ranges_base,
609 // If we have code split among multiple sections or non-contiguous
610 // ranges of code then emit a DW_AT_ranges attribute on the unit that will
611 // remain in the .o file, otherwise add a DW_AT_low_pc.
612 // FIXME: We should use ranges allow reordering of code ala
613 // .subsections_via_symbols in mach-o. This would mean turning on
614 // ranges for all subprogram DIEs for mach-o.
615 DwarfCompileUnit &U = SkCU ? *SkCU : TheCU;
616 if (unsigned NumRanges = TheCU.getRanges().size()) {
618 // A DW_AT_low_pc attribute may also be specified in combination with
619 // DW_AT_ranges to specify the default base address for use in
620 // location lists (see Section 2.6.2) and range lists (see Section
622 U.addUInt(U.getUnitDie(), dwarf::DW_AT_low_pc, dwarf::DW_FORM_addr, 0);
624 U.setBaseAddress(TheCU.getRanges().front().getStart());
625 U.attachRangesOrLowHighPC(U.getUnitDie(), TheCU.takeRanges());
629 // Compute DIE offsets and sizes.
630 InfoHolder.computeSizeAndOffsets();
632 SkeletonHolder.computeSizeAndOffsets();
635 // Emit all Dwarf sections that should come after the content.
636 void DwarfDebug::endModule() {
637 assert(CurFn == nullptr);
638 assert(CurMI == nullptr);
640 // If we aren't actually generating debug info (check beginModule -
641 // conditionalized on !DisableDebugInfoPrinting and the presence of the
642 // llvm.dbg.cu metadata node)
643 if (!MMI->hasDebugInfo())
646 // Finalize the debug info for the module.
647 finalizeModuleInfo();
654 // Emit info into a debug loc section.
657 // Corresponding abbreviations into a abbrev section.
660 // Emit all the DIEs into a debug info section.
663 // Emit info into a debug aranges section.
664 if (GenerateARangeSection)
667 // Emit info into a debug ranges section.
670 if (useSplitDwarf()) {
673 emitDebugAbbrevDWO();
675 // Emit DWO addresses.
676 AddrPool.emit(*Asm, Asm->getObjFileLowering().getDwarfAddrSection());
679 // Emit info into the dwarf accelerator table sections.
680 if (useDwarfAccelTables()) {
683 emitAccelNamespaces();
687 // Emit the pubnames and pubtypes sections if requested.
688 if (HasDwarfPubSections) {
689 emitDebugPubNames(GenerateGnuPubSections);
690 emitDebugPubTypes(GenerateGnuPubSections);
695 AbstractVariables.clear();
698 // Find abstract variable, if any, associated with Var.
700 DwarfDebug::getExistingAbstractVariable(InlinedVariable IV,
701 const DILocalVariable *&Cleansed) {
702 // More then one inlined variable corresponds to one abstract variable.
704 auto I = AbstractVariables.find(Cleansed);
705 if (I != AbstractVariables.end())
706 return I->second.get();
710 DbgVariable *DwarfDebug::getExistingAbstractVariable(InlinedVariable IV) {
711 const DILocalVariable *Cleansed;
712 return getExistingAbstractVariable(IV, Cleansed);
715 void DwarfDebug::createAbstractVariable(const DILocalVariable *Var,
716 LexicalScope *Scope) {
717 auto AbsDbgVariable = make_unique<DbgVariable>(Var, /* IA */ nullptr, this);
718 InfoHolder.addScopeVariable(Scope, AbsDbgVariable.get());
719 AbstractVariables[Var] = std::move(AbsDbgVariable);
722 void DwarfDebug::ensureAbstractVariableIsCreated(InlinedVariable IV,
723 const MDNode *ScopeNode) {
724 const DILocalVariable *Cleansed = nullptr;
725 if (getExistingAbstractVariable(IV, Cleansed))
728 createAbstractVariable(Cleansed, LScopes.getOrCreateAbstractScope(
729 cast<DILocalScope>(ScopeNode)));
732 void DwarfDebug::ensureAbstractVariableIsCreatedIfScoped(
733 InlinedVariable IV, const MDNode *ScopeNode) {
734 const DILocalVariable *Cleansed = nullptr;
735 if (getExistingAbstractVariable(IV, Cleansed))
738 if (LexicalScope *Scope =
739 LScopes.findAbstractScope(cast_or_null<DILocalScope>(ScopeNode)))
740 createAbstractVariable(Cleansed, Scope);
743 // Collect variable information from side table maintained by MMI.
744 void DwarfDebug::collectVariableInfoFromMMITable(
745 DenseSet<InlinedVariable> &Processed) {
746 for (const auto &VI : MMI->getVariableDbgInfo()) {
749 assert(VI.Var->isValidLocationForIntrinsic(VI.Loc) &&
750 "Expected inlined-at fields to agree");
752 InlinedVariable Var(VI.Var, VI.Loc->getInlinedAt());
753 Processed.insert(Var);
754 LexicalScope *Scope = LScopes.findLexicalScope(VI.Loc);
756 // If variable scope is not found then skip this variable.
760 ensureAbstractVariableIsCreatedIfScoped(Var, Scope->getScopeNode());
761 auto RegVar = make_unique<DbgVariable>(Var.first, Var.second, this);
762 RegVar->initializeMMI(VI.Expr, VI.Slot);
763 if (InfoHolder.addScopeVariable(Scope, RegVar.get()))
764 ConcreteVariables.push_back(std::move(RegVar));
768 // Get .debug_loc entry for the instruction range starting at MI.
769 static DebugLocEntry::Value getDebugLocValue(const MachineInstr *MI) {
770 const DIExpression *Expr = MI->getDebugExpression();
772 assert(MI->getNumOperands() == 4);
773 if (MI->getOperand(0).isReg()) {
774 MachineLocation MLoc;
775 // If the second operand is an immediate, this is a
776 // register-indirect address.
777 if (!MI->getOperand(1).isImm())
778 MLoc.set(MI->getOperand(0).getReg());
780 MLoc.set(MI->getOperand(0).getReg(), MI->getOperand(1).getImm());
781 return DebugLocEntry::Value(Expr, MLoc);
783 if (MI->getOperand(0).isImm())
784 return DebugLocEntry::Value(Expr, MI->getOperand(0).getImm());
785 if (MI->getOperand(0).isFPImm())
786 return DebugLocEntry::Value(Expr, MI->getOperand(0).getFPImm());
787 if (MI->getOperand(0).isCImm())
788 return DebugLocEntry::Value(Expr, MI->getOperand(0).getCImm());
790 llvm_unreachable("Unexpected 4-operand DBG_VALUE instruction!");
793 /// Determine whether two variable pieces overlap.
794 static bool piecesOverlap(const DIExpression *P1, const DIExpression *P2) {
795 if (!P1->isBitPiece() || !P2->isBitPiece())
797 unsigned l1 = P1->getBitPieceOffset();
798 unsigned l2 = P2->getBitPieceOffset();
799 unsigned r1 = l1 + P1->getBitPieceSize();
800 unsigned r2 = l2 + P2->getBitPieceSize();
801 // True where [l1,r1[ and [r1,r2[ overlap.
802 return (l1 < r2) && (l2 < r1);
805 /// Build the location list for all DBG_VALUEs in the function that
806 /// describe the same variable. If the ranges of several independent
807 /// pieces of the same variable overlap partially, split them up and
808 /// combine the ranges. The resulting DebugLocEntries are will have
809 /// strict monotonically increasing begin addresses and will never
814 // Ranges History [var, loc, piece ofs size]
815 // 0 | [x, (reg0, piece 0, 32)]
816 // 1 | | [x, (reg1, piece 32, 32)] <- IsPieceOfPrevEntry
818 // 3 | [clobber reg0]
819 // 4 [x, (mem, piece 0, 64)] <- overlapping with both previous pieces of
824 // [0-1] [x, (reg0, piece 0, 32)]
825 // [1-3] [x, (reg0, piece 0, 32), (reg1, piece 32, 32)]
826 // [3-4] [x, (reg1, piece 32, 32)]
827 // [4- ] [x, (mem, piece 0, 64)]
829 DwarfDebug::buildLocationList(SmallVectorImpl<DebugLocEntry> &DebugLoc,
830 const DbgValueHistoryMap::InstrRanges &Ranges) {
831 SmallVector<DebugLocEntry::Value, 4> OpenRanges;
833 for (auto I = Ranges.begin(), E = Ranges.end(); I != E; ++I) {
834 const MachineInstr *Begin = I->first;
835 const MachineInstr *End = I->second;
836 assert(Begin->isDebugValue() && "Invalid History entry");
838 // Check if a variable is inaccessible in this range.
839 if (Begin->getNumOperands() > 1 &&
840 Begin->getOperand(0).isReg() && !Begin->getOperand(0).getReg()) {
845 // If this piece overlaps with any open ranges, truncate them.
846 const DIExpression *DIExpr = Begin->getDebugExpression();
847 auto Last = std::remove_if(OpenRanges.begin(), OpenRanges.end(),
848 [&](DebugLocEntry::Value R) {
849 return piecesOverlap(DIExpr, R.getExpression());
851 OpenRanges.erase(Last, OpenRanges.end());
853 const MCSymbol *StartLabel = getLabelBeforeInsn(Begin);
854 assert(StartLabel && "Forgot label before DBG_VALUE starting a range!");
856 const MCSymbol *EndLabel;
858 EndLabel = getLabelAfterInsn(End);
859 else if (std::next(I) == Ranges.end())
860 EndLabel = Asm->getFunctionEnd();
862 EndLabel = getLabelBeforeInsn(std::next(I)->first);
863 assert(EndLabel && "Forgot label after instruction ending a range!");
865 DEBUG(dbgs() << "DotDebugLoc: " << *Begin << "\n");
867 auto Value = getDebugLocValue(Begin);
868 DebugLocEntry Loc(StartLabel, EndLabel, Value);
869 bool couldMerge = false;
871 // If this is a piece, it may belong to the current DebugLocEntry.
872 if (DIExpr->isBitPiece()) {
873 // Add this value to the list of open ranges.
874 OpenRanges.push_back(Value);
876 // Attempt to add the piece to the last entry.
877 if (!DebugLoc.empty())
878 if (DebugLoc.back().MergeValues(Loc))
883 // Need to add a new DebugLocEntry. Add all values from still
884 // valid non-overlapping pieces.
885 if (OpenRanges.size())
886 Loc.addValues(OpenRanges);
888 DebugLoc.push_back(std::move(Loc));
891 // Attempt to coalesce the ranges of two otherwise identical
893 auto CurEntry = DebugLoc.rbegin();
895 dbgs() << CurEntry->getValues().size() << " Values:\n";
896 for (auto &Value : CurEntry->getValues())
897 Value.getExpression()->dump();
901 auto PrevEntry = std::next(CurEntry);
902 if (PrevEntry != DebugLoc.rend() && PrevEntry->MergeRanges(*CurEntry))
907 DbgVariable *DwarfDebug::createConcreteVariable(LexicalScope &Scope,
908 InlinedVariable IV) {
909 ensureAbstractVariableIsCreatedIfScoped(IV, Scope.getScopeNode());
910 ConcreteVariables.push_back(
911 make_unique<DbgVariable>(IV.first, IV.second, this));
912 InfoHolder.addScopeVariable(&Scope, ConcreteVariables.back().get());
913 return ConcreteVariables.back().get();
916 // Find variables for each lexical scope.
917 void DwarfDebug::collectVariableInfo(DwarfCompileUnit &TheCU,
918 const DISubprogram *SP,
919 DenseSet<InlinedVariable> &Processed) {
920 // Grab the variable info that was squirreled away in the MMI side-table.
921 collectVariableInfoFromMMITable(Processed);
923 for (const auto &I : DbgValues) {
924 InlinedVariable IV = I.first;
925 if (Processed.count(IV))
928 // Instruction ranges, specifying where IV is accessible.
929 const auto &Ranges = I.second;
933 LexicalScope *Scope = nullptr;
934 if (const DILocation *IA = IV.second)
935 Scope = LScopes.findInlinedScope(IV.first->getScope(), IA);
937 Scope = LScopes.findLexicalScope(IV.first->getScope());
938 // If variable scope is not found then skip this variable.
942 Processed.insert(IV);
943 DbgVariable *RegVar = createConcreteVariable(*Scope, IV);
945 const MachineInstr *MInsn = Ranges.front().first;
946 assert(MInsn->isDebugValue() && "History must begin with debug value");
948 // Check if the first DBG_VALUE is valid for the rest of the function.
949 if (Ranges.size() == 1 && Ranges.front().second == nullptr) {
950 RegVar->initializeDbgValue(MInsn);
954 // Handle multiple DBG_VALUE instructions describing one variable.
955 DebugLocStream::ListBuilder List(DebugLocs, TheCU, *Asm, *RegVar, *MInsn);
957 // Build the location list for this variable.
958 SmallVector<DebugLocEntry, 8> Entries;
959 buildLocationList(Entries, Ranges);
961 // If the variable has an DIBasicType, extract it. Basic types cannot have
962 // unique identifiers, so don't bother resolving the type with the
964 const DIBasicType *BT = dyn_cast<DIBasicType>(
965 static_cast<const Metadata *>(IV.first->getType()));
967 // Finalize the entry by lowering it into a DWARF bytestream.
968 for (auto &Entry : Entries)
969 Entry.finalize(*Asm, List, BT);
972 // Collect info for variables that were optimized out.
973 for (const DILocalVariable *DV : SP->getVariables()) {
974 if (Processed.insert(InlinedVariable(DV, nullptr)).second)
975 if (LexicalScope *Scope = LScopes.findLexicalScope(DV->getScope()))
976 createConcreteVariable(*Scope, InlinedVariable(DV, nullptr));
980 // Return Label preceding the instruction.
981 MCSymbol *DwarfDebug::getLabelBeforeInsn(const MachineInstr *MI) {
982 MCSymbol *Label = LabelsBeforeInsn.lookup(MI);
983 assert(Label && "Didn't insert label before instruction");
987 // Return Label immediately following the instruction.
988 MCSymbol *DwarfDebug::getLabelAfterInsn(const MachineInstr *MI) {
989 return LabelsAfterInsn.lookup(MI);
992 // Process beginning of an instruction.
993 void DwarfDebug::beginInstruction(const MachineInstr *MI) {
994 assert(CurMI == nullptr);
996 // Check if source location changes, but ignore DBG_VALUE locations.
997 if (!MI->isDebugValue()) {
998 DebugLoc DL = MI->getDebugLoc();
999 if (DL != PrevInstLoc) {
1003 if (DL == PrologEndLoc) {
1004 Flags |= DWARF2_FLAG_PROLOGUE_END;
1005 PrologEndLoc = DebugLoc();
1006 Flags |= DWARF2_FLAG_IS_STMT;
1009 Asm->OutStreamer->getContext().getCurrentDwarfLoc().getLine())
1010 Flags |= DWARF2_FLAG_IS_STMT;
1012 const MDNode *Scope = DL.getScope();
1013 recordSourceLine(DL.getLine(), DL.getCol(), Scope, Flags);
1014 } else if (UnknownLocations) {
1016 recordSourceLine(0, 0, nullptr, 0);
1021 // Insert labels where requested.
1022 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1023 LabelsBeforeInsn.find(MI);
1026 if (I == LabelsBeforeInsn.end())
1029 // Label already assigned.
1034 PrevLabel = MMI->getContext().createTempSymbol();
1035 Asm->OutStreamer->EmitLabel(PrevLabel);
1037 I->second = PrevLabel;
1040 // Process end of an instruction.
1041 void DwarfDebug::endInstruction() {
1042 assert(CurMI != nullptr);
1043 // Don't create a new label after DBG_VALUE instructions.
1044 // They don't generate code.
1045 if (!CurMI->isDebugValue())
1046 PrevLabel = nullptr;
1048 DenseMap<const MachineInstr *, MCSymbol *>::iterator I =
1049 LabelsAfterInsn.find(CurMI);
1053 if (I == LabelsAfterInsn.end())
1056 // Label already assigned.
1060 // We need a label after this instruction.
1062 PrevLabel = MMI->getContext().createTempSymbol();
1063 Asm->OutStreamer->EmitLabel(PrevLabel);
1065 I->second = PrevLabel;
1068 // Each LexicalScope has first instruction and last instruction to mark
1069 // beginning and end of a scope respectively. Create an inverse map that list
1070 // scopes starts (and ends) with an instruction. One instruction may start (or
1071 // end) multiple scopes. Ignore scopes that are not reachable.
1072 void DwarfDebug::identifyScopeMarkers() {
1073 SmallVector<LexicalScope *, 4> WorkList;
1074 WorkList.push_back(LScopes.getCurrentFunctionScope());
1075 while (!WorkList.empty()) {
1076 LexicalScope *S = WorkList.pop_back_val();
1078 const SmallVectorImpl<LexicalScope *> &Children = S->getChildren();
1079 if (!Children.empty())
1080 WorkList.append(Children.begin(), Children.end());
1082 if (S->isAbstractScope())
1085 for (const InsnRange &R : S->getRanges()) {
1086 assert(R.first && "InsnRange does not have first instruction!");
1087 assert(R.second && "InsnRange does not have second instruction!");
1088 requestLabelBeforeInsn(R.first);
1089 requestLabelAfterInsn(R.second);
1094 static DebugLoc findPrologueEndLoc(const MachineFunction *MF) {
1095 // First known non-DBG_VALUE and non-frame setup location marks
1096 // the beginning of the function body.
1097 for (const auto &MBB : *MF)
1098 for (const auto &MI : MBB)
1099 if (!MI.isDebugValue() && !MI.getFlag(MachineInstr::FrameSetup) &&
1101 return MI.getDebugLoc();
1105 // Gather pre-function debug information. Assumes being called immediately
1106 // after the function entry point has been emitted.
1107 void DwarfDebug::beginFunction(const MachineFunction *MF) {
1110 // If there's no debug info for the function we're not going to do anything.
1111 if (!MMI->hasDebugInfo())
1114 auto DI = MF->getFunction()->getSubprogram();
1118 // Grab the lexical scopes for the function, if we don't have any of those
1119 // then we're not going to be able to do anything.
1120 LScopes.initialize(*MF);
1121 if (LScopes.empty())
1124 assert(DbgValues.empty() && "DbgValues map wasn't cleaned!");
1126 // Make sure that each lexical scope will have a begin/end label.
1127 identifyScopeMarkers();
1129 // Set DwarfDwarfCompileUnitID in MCContext to the Compile Unit this function
1130 // belongs to so that we add to the correct per-cu line table in the
1132 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1133 // FnScope->getScopeNode() and DI->second should represent the same function,
1134 // though they may not be the same MDNode due to inline functions merged in
1135 // LTO where the debug info metadata still differs (either due to distinct
1136 // written differences - two versions of a linkonce_odr function
1137 // written/copied into two separate files, or some sub-optimal metadata that
1138 // isn't structurally identical (see: file path/name info from clang, which
1139 // includes the directory of the cpp file being built, even when the file name
1140 // is absolute (such as an <> lookup header)))
1141 DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
1142 assert(TheCU && "Unable to find compile unit!");
1143 if (Asm->OutStreamer->hasRawTextSupport())
1144 // Use a single line table if we are generating assembly.
1145 Asm->OutStreamer->getContext().setDwarfCompileUnitID(0);
1147 Asm->OutStreamer->getContext().setDwarfCompileUnitID(TheCU->getUniqueID());
1149 // Calculate history for local variables.
1150 calculateDbgValueHistory(MF, Asm->MF->getSubtarget().getRegisterInfo(),
1153 // Request labels for the full history.
1154 for (const auto &I : DbgValues) {
1155 const auto &Ranges = I.second;
1159 // The first mention of a function argument gets the CurrentFnBegin
1160 // label, so arguments are visible when breaking at function entry.
1161 const DILocalVariable *DIVar = Ranges.front().first->getDebugVariable();
1162 if (DIVar->isParameter() &&
1163 getDISubprogram(DIVar->getScope())->describes(MF->getFunction())) {
1164 LabelsBeforeInsn[Ranges.front().first] = Asm->getFunctionBegin();
1165 if (Ranges.front().first->getDebugExpression()->isBitPiece()) {
1166 // Mark all non-overlapping initial pieces.
1167 for (auto I = Ranges.begin(); I != Ranges.end(); ++I) {
1168 const DIExpression *Piece = I->first->getDebugExpression();
1169 if (std::all_of(Ranges.begin(), I,
1170 [&](DbgValueHistoryMap::InstrRange Pred) {
1171 return !piecesOverlap(Piece, Pred.first->getDebugExpression());
1173 LabelsBeforeInsn[I->first] = Asm->getFunctionBegin();
1180 for (const auto &Range : Ranges) {
1181 requestLabelBeforeInsn(Range.first);
1183 requestLabelAfterInsn(Range.second);
1187 PrevInstLoc = DebugLoc();
1188 PrevLabel = Asm->getFunctionBegin();
1190 // Record beginning of function.
1191 PrologEndLoc = findPrologueEndLoc(MF);
1192 if (DILocation *L = PrologEndLoc) {
1193 // We'd like to list the prologue as "not statements" but GDB behaves
1194 // poorly if we do that. Revisit this with caution/GDB (7.5+) testing.
1195 auto *SP = L->getInlinedAtScope()->getSubprogram();
1196 recordSourceLine(SP->getScopeLine(), 0, SP, DWARF2_FLAG_IS_STMT);
1200 // Gather and emit post-function debug information.
1201 void DwarfDebug::endFunction(const MachineFunction *MF) {
1202 assert(CurFn == MF &&
1203 "endFunction should be called with the same function as beginFunction");
1205 if (!MMI->hasDebugInfo() || LScopes.empty() ||
1206 !MF->getFunction()->getSubprogram()) {
1207 // If we don't have a lexical scope for this function then there will
1208 // be a hole in the range information. Keep note of this by setting the
1209 // previously used section to nullptr.
1215 // Set DwarfDwarfCompileUnitID in MCContext to default value.
1216 Asm->OutStreamer->getContext().setDwarfCompileUnitID(0);
1218 LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
1219 auto *SP = cast<DISubprogram>(FnScope->getScopeNode());
1220 DwarfCompileUnit &TheCU = *SPMap.lookup(SP);
1222 DenseSet<InlinedVariable> ProcessedVars;
1223 collectVariableInfo(TheCU, SP, ProcessedVars);
1225 // Add the range of this function to the list of ranges for the CU.
1226 TheCU.addRange(RangeSpan(Asm->getFunctionBegin(), Asm->getFunctionEnd()));
1228 // Under -gmlt, skip building the subprogram if there are no inlined
1229 // subroutines inside it.
1230 if (TheCU.getCUNode()->getEmissionKind() == DIBuilder::LineTablesOnly &&
1231 LScopes.getAbstractScopesList().empty() && !IsDarwin) {
1232 assert(InfoHolder.getScopeVariables().empty());
1233 assert(DbgValues.empty());
1234 // FIXME: This wouldn't be true in LTO with a -g (with inlining) CU followed
1235 // by a -gmlt CU. Add a test and remove this assertion.
1236 assert(AbstractVariables.empty());
1237 LabelsBeforeInsn.clear();
1238 LabelsAfterInsn.clear();
1239 PrevLabel = nullptr;
1245 size_t NumAbstractScopes = LScopes.getAbstractScopesList().size();
1247 // Construct abstract scopes.
1248 for (LexicalScope *AScope : LScopes.getAbstractScopesList()) {
1249 auto *SP = cast<DISubprogram>(AScope->getScopeNode());
1250 // Collect info for variables that were optimized out.
1251 for (const DILocalVariable *DV : SP->getVariables()) {
1252 if (!ProcessedVars.insert(InlinedVariable(DV, nullptr)).second)
1254 ensureAbstractVariableIsCreated(InlinedVariable(DV, nullptr),
1256 assert(LScopes.getAbstractScopesList().size() == NumAbstractScopes
1257 && "ensureAbstractVariableIsCreated inserted abstract scopes");
1259 constructAbstractSubprogramScopeDIE(AScope);
1262 TheCU.constructSubprogramScopeDIE(FnScope);
1263 if (auto *SkelCU = TheCU.getSkeleton())
1264 if (!LScopes.getAbstractScopesList().empty())
1265 SkelCU->constructSubprogramScopeDIE(FnScope);
1268 // Ownership of DbgVariables is a bit subtle - ScopeVariables owns all the
1269 // DbgVariables except those that are also in AbstractVariables (since they
1270 // can be used cross-function)
1271 InfoHolder.getScopeVariables().clear();
1273 LabelsBeforeInsn.clear();
1274 LabelsAfterInsn.clear();
1275 PrevLabel = nullptr;
1279 // Register a source line with debug info. Returns the unique label that was
1280 // emitted and which provides correspondence to the source line list.
1281 void DwarfDebug::recordSourceLine(unsigned Line, unsigned Col, const MDNode *S,
1286 unsigned Discriminator = 0;
1287 if (auto *Scope = cast_or_null<DIScope>(S)) {
1288 Fn = Scope->getFilename();
1289 Dir = Scope->getDirectory();
1290 if (auto *LBF = dyn_cast<DILexicalBlockFile>(Scope))
1291 Discriminator = LBF->getDiscriminator();
1293 unsigned CUID = Asm->OutStreamer->getContext().getDwarfCompileUnitID();
1294 Src = static_cast<DwarfCompileUnit &>(*InfoHolder.getUnits()[CUID])
1295 .getOrCreateSourceID(Fn, Dir);
1297 Asm->OutStreamer->EmitDwarfLocDirective(Src, Line, Col, Flags, 0,
1301 //===----------------------------------------------------------------------===//
1303 //===----------------------------------------------------------------------===//
1305 // Emit the debug info section.
1306 void DwarfDebug::emitDebugInfo() {
1307 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1308 Holder.emitUnits(/* UseOffsets */ false);
1311 // Emit the abbreviation section.
1312 void DwarfDebug::emitAbbreviations() {
1313 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1315 Holder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevSection());
1318 void DwarfDebug::emitAccel(DwarfAccelTable &Accel, MCSection *Section,
1319 StringRef TableName) {
1320 Accel.FinalizeTable(Asm, TableName);
1321 Asm->OutStreamer->SwitchSection(Section);
1323 // Emit the full data.
1324 Accel.emit(Asm, Section->getBeginSymbol(), this);
1327 // Emit visible names into a hashed accelerator table section.
1328 void DwarfDebug::emitAccelNames() {
1329 emitAccel(AccelNames, Asm->getObjFileLowering().getDwarfAccelNamesSection(),
1333 // Emit objective C classes and categories into a hashed accelerator table
1335 void DwarfDebug::emitAccelObjC() {
1336 emitAccel(AccelObjC, Asm->getObjFileLowering().getDwarfAccelObjCSection(),
1340 // Emit namespace dies into a hashed accelerator table.
1341 void DwarfDebug::emitAccelNamespaces() {
1342 emitAccel(AccelNamespace,
1343 Asm->getObjFileLowering().getDwarfAccelNamespaceSection(),
1347 // Emit type dies into a hashed accelerator table.
1348 void DwarfDebug::emitAccelTypes() {
1349 emitAccel(AccelTypes, Asm->getObjFileLowering().getDwarfAccelTypesSection(),
1353 // Public name handling.
1354 // The format for the various pubnames:
1356 // dwarf pubnames - offset/name pairs where the offset is the offset into the CU
1357 // for the DIE that is named.
1359 // gnu pubnames - offset/index value/name tuples where the offset is the offset
1360 // into the CU and the index value is computed according to the type of value
1361 // for the DIE that is named.
1363 // For type units the offset is the offset of the skeleton DIE. For split dwarf
1364 // it's the offset within the debug_info/debug_types dwo section, however, the
1365 // reference in the pubname header doesn't change.
1367 /// computeIndexValue - Compute the gdb index value for the DIE and CU.
1368 static dwarf::PubIndexEntryDescriptor computeIndexValue(DwarfUnit *CU,
1370 dwarf::GDBIndexEntryLinkage Linkage = dwarf::GIEL_STATIC;
1372 // We could have a specification DIE that has our most of our knowledge,
1373 // look for that now.
1374 if (DIEValue SpecVal = Die->findAttribute(dwarf::DW_AT_specification)) {
1375 DIE &SpecDIE = SpecVal.getDIEEntry().getEntry();
1376 if (SpecDIE.findAttribute(dwarf::DW_AT_external))
1377 Linkage = dwarf::GIEL_EXTERNAL;
1378 } else if (Die->findAttribute(dwarf::DW_AT_external))
1379 Linkage = dwarf::GIEL_EXTERNAL;
1381 switch (Die->getTag()) {
1382 case dwarf::DW_TAG_class_type:
1383 case dwarf::DW_TAG_structure_type:
1384 case dwarf::DW_TAG_union_type:
1385 case dwarf::DW_TAG_enumeration_type:
1386 return dwarf::PubIndexEntryDescriptor(
1387 dwarf::GIEK_TYPE, CU->getLanguage() != dwarf::DW_LANG_C_plus_plus
1388 ? dwarf::GIEL_STATIC
1389 : dwarf::GIEL_EXTERNAL);
1390 case dwarf::DW_TAG_typedef:
1391 case dwarf::DW_TAG_base_type:
1392 case dwarf::DW_TAG_subrange_type:
1393 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_TYPE, dwarf::GIEL_STATIC);
1394 case dwarf::DW_TAG_namespace:
1395 return dwarf::GIEK_TYPE;
1396 case dwarf::DW_TAG_subprogram:
1397 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_FUNCTION, Linkage);
1398 case dwarf::DW_TAG_variable:
1399 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE, Linkage);
1400 case dwarf::DW_TAG_enumerator:
1401 return dwarf::PubIndexEntryDescriptor(dwarf::GIEK_VARIABLE,
1402 dwarf::GIEL_STATIC);
1404 return dwarf::GIEK_NONE;
1408 /// emitDebugPubNames - Emit visible names into a debug pubnames section.
1410 void DwarfDebug::emitDebugPubNames(bool GnuStyle) {
1411 MCSection *PSec = GnuStyle
1412 ? Asm->getObjFileLowering().getDwarfGnuPubNamesSection()
1413 : Asm->getObjFileLowering().getDwarfPubNamesSection();
1415 emitDebugPubSection(GnuStyle, PSec, "Names",
1416 &DwarfCompileUnit::getGlobalNames);
1419 void DwarfDebug::emitDebugPubSection(
1420 bool GnuStyle, MCSection *PSec, StringRef Name,
1421 const StringMap<const DIE *> &(DwarfCompileUnit::*Accessor)() const) {
1422 for (const auto &NU : CUMap) {
1423 DwarfCompileUnit *TheU = NU.second;
1425 const auto &Globals = (TheU->*Accessor)();
1427 if (Globals.empty())
1430 if (auto *Skeleton = TheU->getSkeleton())
1433 // Start the dwarf pubnames section.
1434 Asm->OutStreamer->SwitchSection(PSec);
1437 Asm->OutStreamer->AddComment("Length of Public " + Name + " Info");
1438 MCSymbol *BeginLabel = Asm->createTempSymbol("pub" + Name + "_begin");
1439 MCSymbol *EndLabel = Asm->createTempSymbol("pub" + Name + "_end");
1440 Asm->EmitLabelDifference(EndLabel, BeginLabel, 4);
1442 Asm->OutStreamer->EmitLabel(BeginLabel);
1444 Asm->OutStreamer->AddComment("DWARF Version");
1445 Asm->EmitInt16(dwarf::DW_PUBNAMES_VERSION);
1447 Asm->OutStreamer->AddComment("Offset of Compilation Unit Info");
1448 Asm->emitDwarfSymbolReference(TheU->getLabelBegin());
1450 Asm->OutStreamer->AddComment("Compilation Unit Length");
1451 Asm->EmitInt32(TheU->getLength());
1453 // Emit the pubnames for this compilation unit.
1454 for (const auto &GI : Globals) {
1455 const char *Name = GI.getKeyData();
1456 const DIE *Entity = GI.second;
1458 Asm->OutStreamer->AddComment("DIE offset");
1459 Asm->EmitInt32(Entity->getOffset());
1462 dwarf::PubIndexEntryDescriptor Desc = computeIndexValue(TheU, Entity);
1463 Asm->OutStreamer->AddComment(
1464 Twine("Kind: ") + dwarf::GDBIndexEntryKindString(Desc.Kind) + ", " +
1465 dwarf::GDBIndexEntryLinkageString(Desc.Linkage));
1466 Asm->EmitInt8(Desc.toBits());
1469 Asm->OutStreamer->AddComment("External Name");
1470 Asm->OutStreamer->EmitBytes(StringRef(Name, GI.getKeyLength() + 1));
1473 Asm->OutStreamer->AddComment("End Mark");
1475 Asm->OutStreamer->EmitLabel(EndLabel);
1479 void DwarfDebug::emitDebugPubTypes(bool GnuStyle) {
1480 MCSection *PSec = GnuStyle
1481 ? Asm->getObjFileLowering().getDwarfGnuPubTypesSection()
1482 : Asm->getObjFileLowering().getDwarfPubTypesSection();
1484 emitDebugPubSection(GnuStyle, PSec, "Types",
1485 &DwarfCompileUnit::getGlobalTypes);
1488 // Emit visible names into a debug str section.
1489 void DwarfDebug::emitDebugStr() {
1490 DwarfFile &Holder = useSplitDwarf() ? SkeletonHolder : InfoHolder;
1491 Holder.emitStrings(Asm->getObjFileLowering().getDwarfStrSection());
1494 void DwarfDebug::emitDebugLocEntry(ByteStreamer &Streamer,
1495 const DebugLocStream::Entry &Entry) {
1496 auto &&Comments = DebugLocs.getComments(Entry);
1497 auto Comment = Comments.begin();
1498 auto End = Comments.end();
1499 for (uint8_t Byte : DebugLocs.getBytes(Entry))
1500 Streamer.EmitInt8(Byte, Comment != End ? *(Comment++) : "");
1503 static void emitDebugLocValue(const AsmPrinter &AP, const DIBasicType *BT,
1504 ByteStreamer &Streamer,
1505 const DebugLocEntry::Value &Value,
1506 unsigned PieceOffsetInBits) {
1507 DebugLocDwarfExpression DwarfExpr(*AP.MF->getSubtarget().getRegisterInfo(),
1508 AP.getDwarfDebug()->getDwarfVersion(),
1511 if (Value.isInt()) {
1512 if (BT && (BT->getEncoding() == dwarf::DW_ATE_signed ||
1513 BT->getEncoding() == dwarf::DW_ATE_signed_char))
1514 DwarfExpr.AddSignedConstant(Value.getInt());
1516 DwarfExpr.AddUnsignedConstant(Value.getInt());
1517 } else if (Value.isLocation()) {
1518 MachineLocation Loc = Value.getLoc();
1519 const DIExpression *Expr = Value.getExpression();
1520 if (!Expr || !Expr->getNumElements())
1522 AP.EmitDwarfRegOp(Streamer, Loc);
1524 // Complex address entry.
1525 if (Loc.getOffset()) {
1526 DwarfExpr.AddMachineRegIndirect(Loc.getReg(), Loc.getOffset());
1527 DwarfExpr.AddExpression(Expr->expr_op_begin(), Expr->expr_op_end(),
1530 DwarfExpr.AddMachineRegExpression(Expr, Loc.getReg(),
1534 // else ... ignore constant fp. There is not any good way to
1535 // to represent them here in dwarf.
1539 void DebugLocEntry::finalize(const AsmPrinter &AP,
1540 DebugLocStream::ListBuilder &List,
1541 const DIBasicType *BT) {
1542 DebugLocStream::EntryBuilder Entry(List, Begin, End);
1543 BufferByteStreamer Streamer = Entry.getStreamer();
1544 const DebugLocEntry::Value &Value = Values[0];
1545 if (Value.isBitPiece()) {
1546 // Emit all pieces that belong to the same variable and range.
1547 assert(std::all_of(Values.begin(), Values.end(), [](DebugLocEntry::Value P) {
1548 return P.isBitPiece();
1549 }) && "all values are expected to be pieces");
1550 assert(std::is_sorted(Values.begin(), Values.end()) &&
1551 "pieces are expected to be sorted");
1553 unsigned Offset = 0;
1554 for (auto Piece : Values) {
1555 const DIExpression *Expr = Piece.getExpression();
1556 unsigned PieceOffset = Expr->getBitPieceOffset();
1557 unsigned PieceSize = Expr->getBitPieceSize();
1558 assert(Offset <= PieceOffset && "overlapping or duplicate pieces");
1559 if (Offset < PieceOffset) {
1560 // The DWARF spec seriously mandates pieces with no locations for gaps.
1561 DebugLocDwarfExpression Expr(*AP.MF->getSubtarget().getRegisterInfo(),
1562 AP.getDwarfDebug()->getDwarfVersion(),
1564 Expr.AddOpPiece(PieceOffset-Offset, 0);
1565 Offset += PieceOffset-Offset;
1567 Offset += PieceSize;
1569 emitDebugLocValue(AP, BT, Streamer, Piece, PieceOffset);
1572 assert(Values.size() == 1 && "only pieces may have >1 value");
1573 emitDebugLocValue(AP, BT, Streamer, Value, 0);
1577 void DwarfDebug::emitDebugLocEntryLocation(const DebugLocStream::Entry &Entry) {
1579 Asm->OutStreamer->AddComment("Loc expr size");
1580 Asm->EmitInt16(DebugLocs.getBytes(Entry).size());
1583 APByteStreamer Streamer(*Asm);
1584 emitDebugLocEntry(Streamer, Entry);
1587 // Emit locations into the debug loc section.
1588 void DwarfDebug::emitDebugLoc() {
1589 // Start the dwarf loc section.
1590 Asm->OutStreamer->SwitchSection(
1591 Asm->getObjFileLowering().getDwarfLocSection());
1592 unsigned char Size = Asm->getDataLayout().getPointerSize();
1593 for (const auto &List : DebugLocs.getLists()) {
1594 Asm->OutStreamer->EmitLabel(List.Label);
1595 const DwarfCompileUnit *CU = List.CU;
1596 for (const auto &Entry : DebugLocs.getEntries(List)) {
1597 // Set up the range. This range is relative to the entry point of the
1598 // compile unit. This is a hard coded 0 for low_pc when we're emitting
1599 // ranges, or the DW_AT_low_pc on the compile unit otherwise.
1600 if (auto *Base = CU->getBaseAddress()) {
1601 Asm->EmitLabelDifference(Entry.BeginSym, Base, Size);
1602 Asm->EmitLabelDifference(Entry.EndSym, Base, Size);
1604 Asm->OutStreamer->EmitSymbolValue(Entry.BeginSym, Size);
1605 Asm->OutStreamer->EmitSymbolValue(Entry.EndSym, Size);
1608 emitDebugLocEntryLocation(Entry);
1610 Asm->OutStreamer->EmitIntValue(0, Size);
1611 Asm->OutStreamer->EmitIntValue(0, Size);
1615 void DwarfDebug::emitDebugLocDWO() {
1616 Asm->OutStreamer->SwitchSection(
1617 Asm->getObjFileLowering().getDwarfLocDWOSection());
1618 for (const auto &List : DebugLocs.getLists()) {
1619 Asm->OutStreamer->EmitLabel(List.Label);
1620 for (const auto &Entry : DebugLocs.getEntries(List)) {
1621 // Just always use start_length for now - at least that's one address
1622 // rather than two. We could get fancier and try to, say, reuse an
1623 // address we know we've emitted elsewhere (the start of the function?
1624 // The start of the CU or CU subrange that encloses this range?)
1625 Asm->EmitInt8(dwarf::DW_LLE_start_length_entry);
1626 unsigned idx = AddrPool.getIndex(Entry.BeginSym);
1627 Asm->EmitULEB128(idx);
1628 Asm->EmitLabelDifference(Entry.EndSym, Entry.BeginSym, 4);
1630 emitDebugLocEntryLocation(Entry);
1632 Asm->EmitInt8(dwarf::DW_LLE_end_of_list_entry);
1637 const MCSymbol *Start, *End;
1640 // Emit a debug aranges section, containing a CU lookup for any
1641 // address we can tie back to a CU.
1642 void DwarfDebug::emitDebugARanges() {
1643 // Provides a unique id per text section.
1644 MapVector<MCSection *, SmallVector<SymbolCU, 8>> SectionMap;
1646 // Filter labels by section.
1647 for (const SymbolCU &SCU : ArangeLabels) {
1648 if (SCU.Sym->isInSection()) {
1649 // Make a note of this symbol and it's section.
1650 MCSection *Section = &SCU.Sym->getSection();
1651 if (!Section->getKind().isMetadata())
1652 SectionMap[Section].push_back(SCU);
1654 // Some symbols (e.g. common/bss on mach-o) can have no section but still
1655 // appear in the output. This sucks as we rely on sections to build
1656 // arange spans. We can do it without, but it's icky.
1657 SectionMap[nullptr].push_back(SCU);
1661 // Add terminating symbols for each section.
1662 for (const auto &I : SectionMap) {
1663 MCSection *Section = I.first;
1664 MCSymbol *Sym = nullptr;
1667 Sym = Asm->OutStreamer->endSection(Section);
1669 // Insert a final terminator.
1670 SectionMap[Section].push_back(SymbolCU(nullptr, Sym));
1673 DenseMap<DwarfCompileUnit *, std::vector<ArangeSpan>> Spans;
1675 for (auto &I : SectionMap) {
1676 const MCSection *Section = I.first;
1677 SmallVector<SymbolCU, 8> &List = I.second;
1678 if (List.size() < 2)
1681 // If we have no section (e.g. common), just write out
1682 // individual spans for each symbol.
1684 for (const SymbolCU &Cur : List) {
1686 Span.Start = Cur.Sym;
1689 Spans[Cur.CU].push_back(Span);
1694 // Sort the symbols by offset within the section.
1695 std::sort(List.begin(), List.end(),
1696 [&](const SymbolCU &A, const SymbolCU &B) {
1697 unsigned IA = A.Sym ? Asm->OutStreamer->GetSymbolOrder(A.Sym) : 0;
1698 unsigned IB = B.Sym ? Asm->OutStreamer->GetSymbolOrder(B.Sym) : 0;
1700 // Symbols with no order assigned should be placed at the end.
1701 // (e.g. section end labels)
1709 // Build spans between each label.
1710 const MCSymbol *StartSym = List[0].Sym;
1711 for (size_t n = 1, e = List.size(); n < e; n++) {
1712 const SymbolCU &Prev = List[n - 1];
1713 const SymbolCU &Cur = List[n];
1715 // Try and build the longest span we can within the same CU.
1716 if (Cur.CU != Prev.CU) {
1718 Span.Start = StartSym;
1720 Spans[Prev.CU].push_back(Span);
1726 // Start the dwarf aranges section.
1727 Asm->OutStreamer->SwitchSection(
1728 Asm->getObjFileLowering().getDwarfARangesSection());
1730 unsigned PtrSize = Asm->getDataLayout().getPointerSize();
1732 // Build a list of CUs used.
1733 std::vector<DwarfCompileUnit *> CUs;
1734 for (const auto &it : Spans) {
1735 DwarfCompileUnit *CU = it.first;
1739 // Sort the CU list (again, to ensure consistent output order).
1740 std::sort(CUs.begin(), CUs.end(), [](const DwarfUnit *A, const DwarfUnit *B) {
1741 return A->getUniqueID() < B->getUniqueID();
1744 // Emit an arange table for each CU we used.
1745 for (DwarfCompileUnit *CU : CUs) {
1746 std::vector<ArangeSpan> &List = Spans[CU];
1748 // Describe the skeleton CU's offset and length, not the dwo file's.
1749 if (auto *Skel = CU->getSkeleton())
1752 // Emit size of content not including length itself.
1753 unsigned ContentSize =
1754 sizeof(int16_t) + // DWARF ARange version number
1755 sizeof(int32_t) + // Offset of CU in the .debug_info section
1756 sizeof(int8_t) + // Pointer Size (in bytes)
1757 sizeof(int8_t); // Segment Size (in bytes)
1759 unsigned TupleSize = PtrSize * 2;
1761 // 7.20 in the Dwarf specs requires the table to be aligned to a tuple.
1763 OffsetToAlignment(sizeof(int32_t) + ContentSize, TupleSize);
1765 ContentSize += Padding;
1766 ContentSize += (List.size() + 1) * TupleSize;
1768 // For each compile unit, write the list of spans it covers.
1769 Asm->OutStreamer->AddComment("Length of ARange Set");
1770 Asm->EmitInt32(ContentSize);
1771 Asm->OutStreamer->AddComment("DWARF Arange version number");
1772 Asm->EmitInt16(dwarf::DW_ARANGES_VERSION);
1773 Asm->OutStreamer->AddComment("Offset Into Debug Info Section");
1774 Asm->emitDwarfSymbolReference(CU->getLabelBegin());
1775 Asm->OutStreamer->AddComment("Address Size (in bytes)");
1776 Asm->EmitInt8(PtrSize);
1777 Asm->OutStreamer->AddComment("Segment Size (in bytes)");
1780 Asm->OutStreamer->EmitFill(Padding, 0xff);
1782 for (const ArangeSpan &Span : List) {
1783 Asm->EmitLabelReference(Span.Start, PtrSize);
1785 // Calculate the size as being from the span start to it's end.
1787 Asm->EmitLabelDifference(Span.End, Span.Start, PtrSize);
1789 // For symbols without an end marker (e.g. common), we
1790 // write a single arange entry containing just that one symbol.
1791 uint64_t Size = SymSize[Span.Start];
1795 Asm->OutStreamer->EmitIntValue(Size, PtrSize);
1799 Asm->OutStreamer->AddComment("ARange terminator");
1800 Asm->OutStreamer->EmitIntValue(0, PtrSize);
1801 Asm->OutStreamer->EmitIntValue(0, PtrSize);
1805 // Emit visible names into a debug ranges section.
1806 void DwarfDebug::emitDebugRanges() {
1807 // Start the dwarf ranges section.
1808 Asm->OutStreamer->SwitchSection(
1809 Asm->getObjFileLowering().getDwarfRangesSection());
1811 // Size for our labels.
1812 unsigned char Size = Asm->getDataLayout().getPointerSize();
1814 // Grab the specific ranges for the compile units in the module.
1815 for (const auto &I : CUMap) {
1816 DwarfCompileUnit *TheCU = I.second;
1818 if (auto *Skel = TheCU->getSkeleton())
1821 // Iterate over the misc ranges for the compile units in the module.
1822 for (const RangeSpanList &List : TheCU->getRangeLists()) {
1823 // Emit our symbol so we can find the beginning of the range.
1824 Asm->OutStreamer->EmitLabel(List.getSym());
1826 for (const RangeSpan &Range : List.getRanges()) {
1827 const MCSymbol *Begin = Range.getStart();
1828 const MCSymbol *End = Range.getEnd();
1829 assert(Begin && "Range without a begin symbol?");
1830 assert(End && "Range without an end symbol?");
1831 if (auto *Base = TheCU->getBaseAddress()) {
1832 Asm->EmitLabelDifference(Begin, Base, Size);
1833 Asm->EmitLabelDifference(End, Base, Size);
1835 Asm->OutStreamer->EmitSymbolValue(Begin, Size);
1836 Asm->OutStreamer->EmitSymbolValue(End, Size);
1840 // And terminate the list with two 0 values.
1841 Asm->OutStreamer->EmitIntValue(0, Size);
1842 Asm->OutStreamer->EmitIntValue(0, Size);
1847 // DWARF5 Experimental Separate Dwarf emitters.
1849 void DwarfDebug::initSkeletonUnit(const DwarfUnit &U, DIE &Die,
1850 std::unique_ptr<DwarfUnit> NewU) {
1851 NewU->addString(Die, dwarf::DW_AT_GNU_dwo_name,
1852 U.getCUNode()->getSplitDebugFilename());
1854 if (!CompilationDir.empty())
1855 NewU->addString(Die, dwarf::DW_AT_comp_dir, CompilationDir);
1857 addGnuPubAttributes(*NewU, Die);
1859 SkeletonHolder.addUnit(std::move(NewU));
1862 // This DIE has the following attributes: DW_AT_comp_dir, DW_AT_stmt_list,
1863 // DW_AT_low_pc, DW_AT_high_pc, DW_AT_ranges, DW_AT_dwo_name, DW_AT_dwo_id,
1864 // DW_AT_addr_base, DW_AT_ranges_base.
1865 DwarfCompileUnit &DwarfDebug::constructSkeletonCU(const DwarfCompileUnit &CU) {
1867 auto OwnedUnit = make_unique<DwarfCompileUnit>(
1868 CU.getUniqueID(), CU.getCUNode(), Asm, this, &SkeletonHolder);
1869 DwarfCompileUnit &NewCU = *OwnedUnit;
1870 NewCU.initSection(Asm->getObjFileLowering().getDwarfInfoSection());
1872 NewCU.initStmtList();
1874 initSkeletonUnit(CU, NewCU.getUnitDie(), std::move(OwnedUnit));
1879 // Emit the .debug_info.dwo section for separated dwarf. This contains the
1880 // compile units that would normally be in debug_info.
1881 void DwarfDebug::emitDebugInfoDWO() {
1882 assert(useSplitDwarf() && "No split dwarf debug info?");
1883 // Don't emit relocations into the dwo file.
1884 InfoHolder.emitUnits(/* UseOffsets */ true);
1887 // Emit the .debug_abbrev.dwo section for separated dwarf. This contains the
1888 // abbreviations for the .debug_info.dwo section.
1889 void DwarfDebug::emitDebugAbbrevDWO() {
1890 assert(useSplitDwarf() && "No split dwarf?");
1891 InfoHolder.emitAbbrevs(Asm->getObjFileLowering().getDwarfAbbrevDWOSection());
1894 void DwarfDebug::emitDebugLineDWO() {
1895 assert(useSplitDwarf() && "No split dwarf?");
1896 Asm->OutStreamer->SwitchSection(
1897 Asm->getObjFileLowering().getDwarfLineDWOSection());
1898 SplitTypeUnitFileTable.Emit(*Asm->OutStreamer, MCDwarfLineTableParams());
1901 // Emit the .debug_str.dwo section for separated dwarf. This contains the
1902 // string section and is identical in format to traditional .debug_str
1904 void DwarfDebug::emitDebugStrDWO() {
1905 assert(useSplitDwarf() && "No split dwarf?");
1906 MCSection *OffSec = Asm->getObjFileLowering().getDwarfStrOffDWOSection();
1907 InfoHolder.emitStrings(Asm->getObjFileLowering().getDwarfStrDWOSection(),
1911 MCDwarfDwoLineTable *DwarfDebug::getDwoLineTable(const DwarfCompileUnit &CU) {
1912 if (!useSplitDwarf())
1915 SplitTypeUnitFileTable.setCompilationDir(CU.getCUNode()->getDirectory());
1916 return &SplitTypeUnitFileTable;
1919 uint64_t DwarfDebug::makeTypeSignature(StringRef Identifier) {
1921 Hash.update(Identifier);
1922 // ... take the least significant 8 bytes and return those. Our MD5
1923 // implementation always returns its results in little endian, swap bytes
1925 MD5::MD5Result Result;
1927 return support::endian::read64le(Result + 8);
1930 void DwarfDebug::addDwarfTypeUnitType(DwarfCompileUnit &CU,
1931 StringRef Identifier, DIE &RefDie,
1932 const DICompositeType *CTy) {
1933 // Fast path if we're building some type units and one has already used the
1934 // address pool we know we're going to throw away all this work anyway, so
1935 // don't bother building dependent types.
1936 if (!TypeUnitsUnderConstruction.empty() && AddrPool.hasBeenUsed())
1939 const DwarfTypeUnit *&TU = DwarfTypeUnits[CTy];
1941 CU.addDIETypeSignature(RefDie, *TU);
1945 bool TopLevelType = TypeUnitsUnderConstruction.empty();
1946 AddrPool.resetUsedFlag();
1948 auto OwnedUnit = make_unique<DwarfTypeUnit>(
1949 InfoHolder.getUnits().size() + TypeUnitsUnderConstruction.size(), CU, Asm,
1950 this, &InfoHolder, getDwoLineTable(CU));
1951 DwarfTypeUnit &NewTU = *OwnedUnit;
1952 DIE &UnitDie = NewTU.getUnitDie();
1954 TypeUnitsUnderConstruction.push_back(
1955 std::make_pair(std::move(OwnedUnit), CTy));
1957 NewTU.addUInt(UnitDie, dwarf::DW_AT_language, dwarf::DW_FORM_data2,
1960 uint64_t Signature = makeTypeSignature(Identifier);
1961 NewTU.setTypeSignature(Signature);
1963 if (useSplitDwarf())
1964 NewTU.initSection(Asm->getObjFileLowering().getDwarfTypesDWOSection());
1966 CU.applyStmtList(UnitDie);
1968 Asm->getObjFileLowering().getDwarfTypesSection(Signature));
1971 NewTU.setType(NewTU.createTypeDIE(CTy));
1974 auto TypeUnitsToAdd = std::move(TypeUnitsUnderConstruction);
1975 TypeUnitsUnderConstruction.clear();
1977 // Types referencing entries in the address table cannot be placed in type
1979 if (AddrPool.hasBeenUsed()) {
1981 // Remove all the types built while building this type.
1982 // This is pessimistic as some of these types might not be dependent on
1983 // the type that used an address.
1984 for (const auto &TU : TypeUnitsToAdd)
1985 DwarfTypeUnits.erase(TU.second);
1987 // Construct this type in the CU directly.
1988 // This is inefficient because all the dependent types will be rebuilt
1989 // from scratch, including building them in type units, discovering that
1990 // they depend on addresses, throwing them out and rebuilding them.
1991 CU.constructTypeDIE(RefDie, cast<DICompositeType>(CTy));
1995 // If the type wasn't dependent on fission addresses, finish adding the type
1996 // and all its dependent types.
1997 for (auto &TU : TypeUnitsToAdd)
1998 InfoHolder.addUnit(std::move(TU.first));
2000 CU.addDIETypeSignature(RefDie, NewTU);
2003 // Accelerator table mutators - add each name along with its companion
2004 // DIE to the proper table while ensuring that the name that we're going
2005 // to reference is in the string table. We do this since the names we
2006 // add may not only be identical to the names in the DIE.
2007 void DwarfDebug::addAccelName(StringRef Name, const DIE &Die) {
2008 if (!useDwarfAccelTables())
2010 AccelNames.AddName(InfoHolder.getStringPool().getEntry(*Asm, Name), &Die);
2013 void DwarfDebug::addAccelObjC(StringRef Name, const DIE &Die) {
2014 if (!useDwarfAccelTables())
2016 AccelObjC.AddName(InfoHolder.getStringPool().getEntry(*Asm, Name), &Die);
2019 void DwarfDebug::addAccelNamespace(StringRef Name, const DIE &Die) {
2020 if (!useDwarfAccelTables())
2022 AccelNamespace.AddName(InfoHolder.getStringPool().getEntry(*Asm, Name), &Die);
2025 void DwarfDebug::addAccelType(StringRef Name, const DIE &Die, char Flags) {
2026 if (!useDwarfAccelTables())
2028 AccelTypes.AddName(InfoHolder.getStringPool().getEntry(*Asm, Name), &Die);