1 #include "DwarfCompileUnit.h"
3 #include "llvm/CodeGen/MachineFunction.h"
4 #include "llvm/IR/DataLayout.h"
5 #include "llvm/IR/GlobalValue.h"
6 #include "llvm/IR/GlobalVariable.h"
7 #include "llvm/IR/Instruction.h"
8 #include "llvm/MC/MCAsmInfo.h"
9 #include "llvm/MC/MCStreamer.h"
10 #include "llvm/Target/TargetFrameLowering.h"
11 #include "llvm/Target/TargetLoweringObjectFile.h"
12 #include "llvm/Target/TargetMachine.h"
13 #include "llvm/Target/TargetSubtargetInfo.h"
14 #include "llvm/Target/TargetRegisterInfo.h"
18 DwarfCompileUnit::DwarfCompileUnit(unsigned UID, DICompileUnit Node,
19 AsmPrinter *A, DwarfDebug *DW,
21 : DwarfUnit(UID, dwarf::DW_TAG_compile_unit, Node, A, DW, DWU),
22 Skeleton(nullptr), LabelBegin(nullptr), BaseAddress(nullptr) {
23 insertDIE(Node, &getUnitDie());
26 /// addLabelAddress - Add a dwarf label attribute data and value using
27 /// DW_FORM_addr or DW_FORM_GNU_addr_index.
29 void DwarfCompileUnit::addLabelAddress(DIE &Die, dwarf::Attribute Attribute,
30 const MCSymbol *Label) {
32 // Don't use the address pool in non-fission or in the skeleton unit itself.
33 // FIXME: Once GDB supports this, it's probably worthwhile using the address
34 // pool from the skeleton - maybe even in non-fission (possibly fewer
35 // relocations by sharing them in the pool, but we have other ideas about how
36 // to reduce the number of relocations as well/instead).
37 if (!DD->useSplitDwarf() || !Skeleton)
38 return addLocalLabelAddress(Die, Attribute, Label);
41 DD->addArangeLabel(SymbolCU(this, Label));
43 unsigned idx = DD->getAddressPool().getIndex(Label);
44 DIEValue *Value = new (DIEValueAllocator) DIEInteger(idx);
45 Die.addValue(Attribute, dwarf::DW_FORM_GNU_addr_index, Value);
48 void DwarfCompileUnit::addLocalLabelAddress(DIE &Die,
49 dwarf::Attribute Attribute,
50 const MCSymbol *Label) {
52 DD->addArangeLabel(SymbolCU(this, Label));
54 Die.addValue(Attribute, dwarf::DW_FORM_addr,
55 Label ? (DIEValue *)new (DIEValueAllocator) DIELabel(Label)
56 : new (DIEValueAllocator) DIEInteger(0));
59 unsigned DwarfCompileUnit::getOrCreateSourceID(StringRef FileName,
61 // If we print assembly, we can't separate .file entries according to
62 // compile units. Thus all files will belong to the default compile unit.
64 // FIXME: add a better feature test than hasRawTextSupport. Even better,
65 // extend .file to support this.
66 return Asm->OutStreamer.EmitDwarfFileDirective(
68 Asm->OutStreamer.hasRawTextSupport() ? 0 : getUniqueID());
71 // Return const expression if value is a GEP to access merged global
73 // i8* getelementptr ({ i8, i8, i8, i8 }* @_MergedGlobals, i32 0, i32 0)
74 static const ConstantExpr *getMergedGlobalExpr(const Value *V) {
75 const ConstantExpr *CE = dyn_cast_or_null<ConstantExpr>(V);
76 if (!CE || CE->getNumOperands() != 3 ||
77 CE->getOpcode() != Instruction::GetElementPtr)
80 // First operand points to a global struct.
81 Value *Ptr = CE->getOperand(0);
82 if (!isa<GlobalValue>(Ptr) ||
83 !isa<StructType>(cast<PointerType>(Ptr->getType())->getElementType()))
86 // Second operand is zero.
87 const ConstantInt *CI = dyn_cast_or_null<ConstantInt>(CE->getOperand(1));
88 if (!CI || !CI->isZero())
91 // Third operand is offset.
92 if (!isa<ConstantInt>(CE->getOperand(2)))
98 /// getOrCreateGlobalVariableDIE - get or create global variable DIE.
99 DIE *DwarfCompileUnit::getOrCreateGlobalVariableDIE(DIGlobalVariable GV) {
100 // Check for pre-existence.
101 if (DIE *Die = getDIE(GV))
104 assert(GV.isGlobalVariable());
106 DIScope GVContext = DD->resolve(GV.getContext());
107 DIType GTy = DD->resolve(GV.getType());
109 // Construct the context before querying for the existence of the DIE in
110 // case such construction creates the DIE.
111 DIE *ContextDIE = getOrCreateContextDIE(GVContext);
114 DIE *VariableDIE = &createAndAddDIE(GV.getTag(), *ContextDIE, GV);
117 if (DIDerivedType SDMDecl = GV.getStaticDataMemberDeclaration()) {
118 DeclContext = resolve(SDMDecl.getContext());
119 assert(SDMDecl.isStaticMember() && "Expected static member decl");
120 assert(GV.isDefinition());
121 // We need the declaration DIE that is in the static member's class.
122 DIE *VariableSpecDIE = getOrCreateStaticMemberDIE(SDMDecl);
123 addDIEEntry(*VariableDIE, dwarf::DW_AT_specification, *VariableSpecDIE);
125 DeclContext = resolve(GV.getContext());
126 // Add name and type.
127 addString(*VariableDIE, dwarf::DW_AT_name, GV.getDisplayName());
128 addType(*VariableDIE, GTy);
131 if (!GV.isLocalToUnit())
132 addFlag(*VariableDIE, dwarf::DW_AT_external);
134 // Add line number info.
135 addSourceLine(*VariableDIE, GV);
138 if (!GV.isDefinition())
139 addFlag(*VariableDIE, dwarf::DW_AT_declaration);
142 bool addToAccelTable = false;
143 bool isGlobalVariable = GV.getGlobal() != nullptr;
144 if (isGlobalVariable) {
145 addToAccelTable = true;
146 DIELoc *Loc = new (DIEValueAllocator) DIELoc();
147 const MCSymbol *Sym = Asm->getSymbol(GV.getGlobal());
148 if (GV.getGlobal()->isThreadLocal()) {
149 // FIXME: Make this work with -gsplit-dwarf.
150 unsigned PointerSize = Asm->getDataLayout().getPointerSize();
151 assert((PointerSize == 4 || PointerSize == 8) &&
152 "Add support for other sizes if necessary");
153 // Based on GCC's support for TLS:
154 if (!DD->useSplitDwarf()) {
155 // 1) Start with a constNu of the appropriate pointer size
156 addUInt(*Loc, dwarf::DW_FORM_data1,
157 PointerSize == 4 ? dwarf::DW_OP_const4u : dwarf::DW_OP_const8u);
158 // 2) containing the (relocated) offset of the TLS variable
159 // within the module's TLS block.
160 addExpr(*Loc, dwarf::DW_FORM_udata,
161 Asm->getObjFileLowering().getDebugThreadLocalSymbol(Sym));
163 addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_GNU_const_index);
164 addUInt(*Loc, dwarf::DW_FORM_udata,
165 DD->getAddressPool().getIndex(Sym, /* TLS */ true));
167 // 3) followed by a custom OP to make the debugger do a TLS lookup.
168 addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_GNU_push_tls_address);
170 DD->addArangeLabel(SymbolCU(this, Sym));
171 addOpAddress(*Loc, Sym);
174 addBlock(*VariableDIE, dwarf::DW_AT_location, Loc);
175 // Add the linkage name.
176 StringRef LinkageName = GV.getLinkageName();
177 if (!LinkageName.empty())
178 // From DWARF4: DIEs to which DW_AT_linkage_name may apply include:
179 // TAG_common_block, TAG_constant, TAG_entry_point, TAG_subprogram and
181 addString(*VariableDIE,
182 DD->getDwarfVersion() >= 4 ? dwarf::DW_AT_linkage_name
183 : dwarf::DW_AT_MIPS_linkage_name,
184 GlobalValue::getRealLinkageName(LinkageName));
185 } else if (const ConstantInt *CI =
186 dyn_cast_or_null<ConstantInt>(GV.getConstant())) {
187 addConstantValue(*VariableDIE, CI, GTy);
188 } else if (const ConstantExpr *CE = getMergedGlobalExpr(GV.getConstant())) {
189 addToAccelTable = true;
190 // GV is a merged global.
191 DIELoc *Loc = new (DIEValueAllocator) DIELoc();
192 Value *Ptr = CE->getOperand(0);
193 MCSymbol *Sym = Asm->getSymbol(cast<GlobalValue>(Ptr));
194 DD->addArangeLabel(SymbolCU(this, Sym));
195 addOpAddress(*Loc, Sym);
196 addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_constu);
197 SmallVector<Value *, 3> Idx(CE->op_begin() + 1, CE->op_end());
198 addUInt(*Loc, dwarf::DW_FORM_udata,
199 Asm->getDataLayout().getIndexedOffset(Ptr->getType(), Idx));
200 addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_plus);
201 addBlock(*VariableDIE, dwarf::DW_AT_location, Loc);
204 if (addToAccelTable) {
205 DD->addAccelName(GV.getName(), *VariableDIE);
207 // If the linkage name is different than the name, go ahead and output
208 // that as well into the name table.
209 if (GV.getLinkageName() != "" && GV.getName() != GV.getLinkageName())
210 DD->addAccelName(GV.getLinkageName(), *VariableDIE);
213 addGlobalName(GV.getName(), *VariableDIE, DeclContext);
217 void DwarfCompileUnit::addRange(RangeSpan Range) {
218 bool SameAsPrevCU = this == DD->getPrevCU();
220 // If we have no current ranges just add the range and return, otherwise,
221 // check the current section and CU against the previous section and CU we
222 // emitted into and the subprogram was contained within. If these are the
223 // same then extend our current range, otherwise add this as a new range.
224 if (CURanges.empty() || !SameAsPrevCU ||
225 (&CURanges.back().getEnd()->getSection() !=
226 &Range.getEnd()->getSection())) {
227 CURanges.push_back(Range);
231 CURanges.back().setEnd(Range.getEnd());
234 void DwarfCompileUnit::addSectionLabel(DIE &Die, dwarf::Attribute Attribute,
235 const MCSymbol *Label,
236 const MCSymbol *Sec) {
237 if (Asm->MAI->doesDwarfUseRelocationsAcrossSections())
238 addLabel(Die, Attribute,
239 DD->getDwarfVersion() >= 4 ? dwarf::DW_FORM_sec_offset
240 : dwarf::DW_FORM_data4,
243 addSectionDelta(Die, Attribute, Label, Sec);
246 void DwarfCompileUnit::initStmtList(MCSymbol *DwarfLineSectionSym) {
247 // Define start line table label for each Compile Unit.
248 MCSymbol *LineTableStartSym =
249 Asm->OutStreamer.getDwarfLineTableSymbol(getUniqueID());
251 stmtListIndex = UnitDie.getValues().size();
253 // DW_AT_stmt_list is a offset of line number information for this
254 // compile unit in debug_line section. For split dwarf this is
255 // left in the skeleton CU and so not included.
256 // The line table entries are not always emitted in assembly, so it
257 // is not okay to use line_table_start here.
258 addSectionLabel(UnitDie, dwarf::DW_AT_stmt_list, LineTableStartSym,
259 DwarfLineSectionSym);
262 void DwarfCompileUnit::applyStmtList(DIE &D) {
263 D.addValue(dwarf::DW_AT_stmt_list,
264 UnitDie.getAbbrev().getData()[stmtListIndex].getForm(),
265 UnitDie.getValues()[stmtListIndex]);
268 void DwarfCompileUnit::attachLowHighPC(DIE &D, const MCSymbol *Begin,
269 const MCSymbol *End) {
270 assert(Begin && "Begin label should not be null!");
271 assert(End && "End label should not be null!");
272 assert(Begin->isDefined() && "Invalid starting label");
273 assert(End->isDefined() && "Invalid end label");
275 addLabelAddress(D, dwarf::DW_AT_low_pc, Begin);
276 if (DD->getDwarfVersion() < 4)
277 addLabelAddress(D, dwarf::DW_AT_high_pc, End);
279 addLabelDelta(D, dwarf::DW_AT_high_pc, End, Begin);
282 // Find DIE for the given subprogram and attach appropriate DW_AT_low_pc
283 // and DW_AT_high_pc attributes. If there are global variables in this
284 // scope then create and insert DIEs for these variables.
285 DIE &DwarfCompileUnit::updateSubprogramScopeDIE(DISubprogram SP) {
286 DIE *SPDie = getOrCreateSubprogramDIE(SP, includeMinimalInlineScopes());
288 attachLowHighPC(*SPDie, DD->getFunctionBeginSym(), DD->getFunctionEndSym());
289 if (!DD->getCurrentFunction()->getTarget().Options.DisableFramePointerElim(
290 *DD->getCurrentFunction()))
291 addFlag(*SPDie, dwarf::DW_AT_APPLE_omit_frame_ptr);
293 // Only include DW_AT_frame_base in full debug info
294 if (!includeMinimalInlineScopes()) {
295 const TargetRegisterInfo *RI =
296 Asm->TM.getSubtargetImpl()->getRegisterInfo();
297 MachineLocation Location(RI->getFrameRegister(*Asm->MF));
298 addAddress(*SPDie, dwarf::DW_AT_frame_base, Location);
301 // Add name to the name table, we do this here because we're guaranteed
302 // to have concrete versions of our DW_TAG_subprogram nodes.
303 DD->addSubprogramNames(SP, *SPDie);
308 // Construct a DIE for this scope.
309 void DwarfCompileUnit::constructScopeDIE(
310 LexicalScope *Scope, SmallVectorImpl<std::unique_ptr<DIE>> &FinalChildren) {
311 if (!Scope || !Scope->getScopeNode())
314 DIScope DS(Scope->getScopeNode());
316 assert((Scope->getInlinedAt() || !DS.isSubprogram()) &&
317 "Only handle inlined subprograms here, use "
318 "constructSubprogramScopeDIE for non-inlined "
321 SmallVector<std::unique_ptr<DIE>, 8> Children;
323 // We try to create the scope DIE first, then the children DIEs. This will
324 // avoid creating un-used children then removing them later when we find out
325 // the scope DIE is null.
326 std::unique_ptr<DIE> ScopeDIE;
327 if (Scope->getParent() && DS.isSubprogram()) {
328 ScopeDIE = constructInlinedScopeDIE(Scope);
331 // We create children when the scope DIE is not null.
332 createScopeChildrenDIE(Scope, Children);
334 // Early exit when we know the scope DIE is going to be null.
335 if (DD->isLexicalScopeDIENull(Scope))
338 unsigned ChildScopeCount;
340 // We create children here when we know the scope DIE is not going to be
341 // null and the children will be added to the scope DIE.
342 createScopeChildrenDIE(Scope, Children, &ChildScopeCount);
344 // Skip imported directives in gmlt-like data.
345 if (!includeMinimalInlineScopes()) {
346 // There is no need to emit empty lexical block DIE.
347 for (const auto &E : DD->findImportedEntitiesForScope(DS))
349 constructImportedEntityDIE(DIImportedEntity(E.second)));
352 // If there are only other scopes as children, put them directly in the
353 // parent instead, as this scope would serve no purpose.
354 if (Children.size() == ChildScopeCount) {
355 FinalChildren.insert(FinalChildren.end(),
356 std::make_move_iterator(Children.begin()),
357 std::make_move_iterator(Children.end()));
360 ScopeDIE = constructLexicalScopeDIE(Scope);
361 assert(ScopeDIE && "Scope DIE should not be null.");
365 for (auto &I : Children)
366 ScopeDIE->addChild(std::move(I));
368 FinalChildren.push_back(std::move(ScopeDIE));
371 void DwarfCompileUnit::addSectionDelta(DIE &Die, dwarf::Attribute Attribute,
372 const MCSymbol *Hi, const MCSymbol *Lo) {
373 DIEValue *Value = new (DIEValueAllocator) DIEDelta(Hi, Lo);
374 Die.addValue(Attribute, DD->getDwarfVersion() >= 4 ? dwarf::DW_FORM_sec_offset
375 : dwarf::DW_FORM_data4,
379 void DwarfCompileUnit::addScopeRangeList(DIE &ScopeDIE,
380 SmallVector<RangeSpan, 2> Range) {
381 // Emit offset in .debug_range as a relocatable label. emitDIE will handle
382 // emitting it appropriately.
383 auto *RangeSectionSym = DD->getRangeSectionSym();
386 Asm->GetTempSymbol("debug_ranges", DD->getNextRangeNumber()),
389 // Under fission, ranges are specified by constant offsets relative to the
390 // CU's DW_AT_GNU_ranges_base.
392 addSectionDelta(ScopeDIE, dwarf::DW_AT_ranges, List.getSym(),
395 addSectionLabel(ScopeDIE, dwarf::DW_AT_ranges, List.getSym(),
398 // Add the range list to the set of ranges to be emitted.
399 (Skeleton ? Skeleton : this)->CURangeLists.push_back(std::move(List));
402 void DwarfCompileUnit::attachRangesOrLowHighPC(
403 DIE &Die, SmallVector<RangeSpan, 2> Ranges) {
404 if (Ranges.size() == 1) {
405 const auto &single = Ranges.front();
406 attachLowHighPC(Die, single.getStart(), single.getEnd());
408 addScopeRangeList(Die, std::move(Ranges));
411 void DwarfCompileUnit::attachRangesOrLowHighPC(
412 DIE &Die, const SmallVectorImpl<InsnRange> &Ranges) {
413 SmallVector<RangeSpan, 2> List;
414 List.reserve(Ranges.size());
415 for (const InsnRange &R : Ranges)
416 List.push_back(RangeSpan(DD->getLabelBeforeInsn(R.first),
417 DD->getLabelAfterInsn(R.second)));
418 attachRangesOrLowHighPC(Die, std::move(List));
421 // This scope represents inlined body of a function. Construct DIE to
422 // represent this concrete inlined copy of the function.
424 DwarfCompileUnit::constructInlinedScopeDIE(LexicalScope *Scope) {
425 assert(Scope->getScopeNode());
426 DIScope DS(Scope->getScopeNode());
427 DISubprogram InlinedSP = getDISubprogram(DS);
428 // Find the subprogram's DwarfCompileUnit in the SPMap in case the subprogram
429 // was inlined from another compile unit.
430 DIE *OriginDIE = DU->getAbstractSPDies()[InlinedSP];
431 assert(OriginDIE && "Unable to find original DIE for an inlined subprogram.");
433 auto ScopeDIE = make_unique<DIE>(dwarf::DW_TAG_inlined_subroutine);
434 addDIEEntry(*ScopeDIE, dwarf::DW_AT_abstract_origin, *OriginDIE);
436 attachRangesOrLowHighPC(*ScopeDIE, Scope->getRanges());
438 // Add the call site information to the DIE.
439 DILocation DL(Scope->getInlinedAt());
440 addUInt(*ScopeDIE, dwarf::DW_AT_call_file, None,
441 getOrCreateSourceID(DL.getFilename(), DL.getDirectory()));
442 addUInt(*ScopeDIE, dwarf::DW_AT_call_line, None, DL.getLineNumber());
444 // Add name to the name table, we do this here because we're guaranteed
445 // to have concrete versions of our DW_TAG_inlined_subprogram nodes.
446 DD->addSubprogramNames(InlinedSP, *ScopeDIE);
451 // Construct new DW_TAG_lexical_block for this scope and attach
452 // DW_AT_low_pc/DW_AT_high_pc labels.
454 DwarfCompileUnit::constructLexicalScopeDIE(LexicalScope *Scope) {
455 if (DD->isLexicalScopeDIENull(Scope))
458 auto ScopeDIE = make_unique<DIE>(dwarf::DW_TAG_lexical_block);
459 if (Scope->isAbstractScope())
462 attachRangesOrLowHighPC(*ScopeDIE, Scope->getRanges());
467 /// constructVariableDIE - Construct a DIE for the given DbgVariable.
468 std::unique_ptr<DIE> DwarfCompileUnit::constructVariableDIE(DbgVariable &DV,
470 auto D = constructVariableDIEImpl(DV, Abstract);
476 DwarfCompileUnit::constructVariableDIEImpl(const DbgVariable &DV,
478 // Define variable debug information entry.
479 auto VariableDie = make_unique<DIE>(DV.getTag());
482 applyVariableAttributes(DV, *VariableDie);
486 // Add variable address.
488 unsigned Offset = DV.getDotDebugLocOffset();
490 addLocationList(*VariableDie, dwarf::DW_AT_location, Offset);
494 // Check if variable is described by a DBG_VALUE instruction.
495 if (const MachineInstr *DVInsn = DV.getMInsn()) {
496 assert(DVInsn->getNumOperands() == 4);
497 if (DVInsn->getOperand(0).isReg()) {
498 const MachineOperand RegOp = DVInsn->getOperand(0);
499 // If the second operand is an immediate, this is an indirect value.
500 if (DVInsn->getOperand(1).isImm()) {
501 MachineLocation Location(RegOp.getReg(),
502 DVInsn->getOperand(1).getImm());
503 addVariableAddress(DV, *VariableDie, Location);
504 } else if (RegOp.getReg())
505 addVariableAddress(DV, *VariableDie, MachineLocation(RegOp.getReg()));
506 } else if (DVInsn->getOperand(0).isImm())
507 addConstantValue(*VariableDie, DVInsn->getOperand(0), DV.getType());
508 else if (DVInsn->getOperand(0).isFPImm())
509 addConstantFPValue(*VariableDie, DVInsn->getOperand(0));
510 else if (DVInsn->getOperand(0).isCImm())
511 addConstantValue(*VariableDie, DVInsn->getOperand(0).getCImm(),
517 // .. else use frame index.
518 int FI = DV.getFrameIndex();
520 unsigned FrameReg = 0;
521 const TargetFrameLowering *TFI =
522 Asm->TM.getSubtargetImpl()->getFrameLowering();
523 int Offset = TFI->getFrameIndexReference(*Asm->MF, FI, FrameReg);
524 MachineLocation Location(FrameReg, Offset);
525 addVariableAddress(DV, *VariableDie, Location);
531 std::unique_ptr<DIE> DwarfCompileUnit::constructVariableDIE(
532 DbgVariable &DV, const LexicalScope &Scope, DIE *&ObjectPointer) {
533 auto Var = constructVariableDIE(DV, Scope.isAbstractScope());
534 if (DV.isObjectPointer())
535 ObjectPointer = Var.get();
539 DIE *DwarfCompileUnit::createScopeChildrenDIE(
540 LexicalScope *Scope, SmallVectorImpl<std::unique_ptr<DIE>> &Children,
541 unsigned *ChildScopeCount) {
542 DIE *ObjectPointer = nullptr;
544 for (DbgVariable *DV : DU->getScopeVariables().lookup(Scope))
545 Children.push_back(constructVariableDIE(*DV, *Scope, ObjectPointer));
547 unsigned ChildCountWithoutScopes = Children.size();
549 for (LexicalScope *LS : Scope->getChildren())
550 constructScopeDIE(LS, Children);
553 *ChildScopeCount = Children.size() - ChildCountWithoutScopes;
555 return ObjectPointer;
558 void DwarfCompileUnit::constructSubprogramScopeDIE(LexicalScope *Scope) {
559 assert(Scope && Scope->getScopeNode());
560 assert(!Scope->getInlinedAt());
561 assert(!Scope->isAbstractScope());
562 DISubprogram Sub(Scope->getScopeNode());
564 assert(Sub.isSubprogram());
566 DD->getProcessedSPNodes().insert(Sub);
568 DIE &ScopeDIE = updateSubprogramScopeDIE(Sub);
570 // If this is a variadic function, add an unspecified parameter.
571 DITypeArray FnArgs = Sub.getType().getTypeArray();
573 // Collect lexical scope children first.
574 // ObjectPointer might be a local (non-argument) local variable if it's a
575 // block's synthetic this pointer.
576 if (DIE *ObjectPointer = createAndAddScopeChildren(Scope, ScopeDIE))
577 addDIEEntry(ScopeDIE, dwarf::DW_AT_object_pointer, *ObjectPointer);
579 // If we have a single element of null, it is a function that returns void.
580 // If we have more than one elements and the last one is null, it is a
581 // variadic function.
582 if (FnArgs.getNumElements() > 1 &&
583 !FnArgs.getElement(FnArgs.getNumElements() - 1) &&
584 !includeMinimalInlineScopes())
585 ScopeDIE.addChild(make_unique<DIE>(dwarf::DW_TAG_unspecified_parameters));
588 DIE *DwarfCompileUnit::createAndAddScopeChildren(LexicalScope *Scope,
590 // We create children when the scope DIE is not null.
591 SmallVector<std::unique_ptr<DIE>, 8> Children;
592 DIE *ObjectPointer = createScopeChildrenDIE(Scope, Children);
595 for (auto &I : Children)
596 ScopeDIE.addChild(std::move(I));
598 return ObjectPointer;
602 DwarfCompileUnit::constructAbstractSubprogramScopeDIE(LexicalScope *Scope) {
603 DIE *&AbsDef = DU->getAbstractSPDies()[Scope->getScopeNode()];
607 DISubprogram SP(Scope->getScopeNode());
611 if (includeMinimalInlineScopes())
612 ContextDIE = &getUnitDie();
613 // Some of this is duplicated from DwarfUnit::getOrCreateSubprogramDIE, with
614 // the important distinction that the DIDescriptor is not associated with the
615 // DIE (since the DIDescriptor will be associated with the concrete DIE, if
616 // any). It could be refactored to some common utility function.
617 else if (DISubprogram SPDecl = SP.getFunctionDeclaration()) {
618 ContextDIE = &getUnitDie();
619 getOrCreateSubprogramDIE(SPDecl);
621 ContextDIE = getOrCreateContextDIE(resolve(SP.getContext()));
623 // Passing null as the associated DIDescriptor because the abstract definition
624 // shouldn't be found by lookup.
626 &createAndAddDIE(dwarf::DW_TAG_subprogram, *ContextDIE, DIDescriptor());
627 applySubprogramAttributesToDefinition(SP, *AbsDef);
629 if (!includeMinimalInlineScopes())
630 addUInt(*AbsDef, dwarf::DW_AT_inline, None, dwarf::DW_INL_inlined);
631 if (DIE *ObjectPointer = createAndAddScopeChildren(Scope, *AbsDef))
632 addDIEEntry(*AbsDef, dwarf::DW_AT_object_pointer, *ObjectPointer);
636 DwarfCompileUnit::constructImportedEntityDIE(const DIImportedEntity &Module) {
637 assert(Module.Verify() &&
638 "Use one of the MDNode * overloads to handle invalid metadata");
639 std::unique_ptr<DIE> IMDie = make_unique<DIE>((dwarf::Tag)Module.getTag());
640 insertDIE(Module, IMDie.get());
642 DIDescriptor Entity = resolve(Module.getEntity());
643 if (Entity.isNameSpace())
644 EntityDie = getOrCreateNameSpace(DINameSpace(Entity));
645 else if (Entity.isSubprogram())
646 EntityDie = getOrCreateSubprogramDIE(DISubprogram(Entity));
647 else if (Entity.isType())
648 EntityDie = getOrCreateTypeDIE(DIType(Entity));
649 else if (Entity.isGlobalVariable())
650 EntityDie = getOrCreateGlobalVariableDIE(DIGlobalVariable(Entity));
652 EntityDie = getDIE(Entity);
654 addSourceLine(*IMDie, Module.getLineNumber(),
655 Module.getContext().getFilename(),
656 Module.getContext().getDirectory());
657 addDIEEntry(*IMDie, dwarf::DW_AT_import, *EntityDie);
658 StringRef Name = Module.getName();
660 addString(*IMDie, dwarf::DW_AT_name, Name);
665 void DwarfCompileUnit::finishSubprogramDefinition(DISubprogram SP) {
667 if (DIE *AbsSPDIE = DU->getAbstractSPDies().lookup(SP)) {
669 // If this subprogram has an abstract definition, reference that
670 addDIEEntry(*D, dwarf::DW_AT_abstract_origin, *AbsSPDIE);
672 if (!D && !includeMinimalInlineScopes())
673 // Lazily construct the subprogram if we didn't see either concrete or
674 // inlined versions during codegen. (except in -gmlt ^ where we want
675 // to omit these entirely)
676 D = getOrCreateSubprogramDIE(SP);
678 // And attach the attributes
679 applySubprogramAttributesToDefinition(SP, *D);
682 void DwarfCompileUnit::collectDeadVariables(DISubprogram SP) {
683 assert(SP.isSubprogram() && "CU's subprogram list contains a non-subprogram");
684 assert(SP.isDefinition() &&
685 "CU's subprogram list contains a subprogram declaration");
686 DIArray Variables = SP.getVariables();
687 if (Variables.getNumElements() == 0)
690 DIE *SPDIE = DU->getAbstractSPDies().lookup(SP);
694 for (unsigned vi = 0, ve = Variables.getNumElements(); vi != ve; ++vi) {
695 DIVariable DV(Variables.getElement(vi));
696 assert(DV.isVariable());
697 DbgVariable NewVar(DV, DIExpression(nullptr), DD);
698 auto VariableDie = constructVariableDIE(NewVar);
699 applyVariableAttributes(NewVar, *VariableDie);
700 SPDIE->addChild(std::move(VariableDie));
704 void DwarfCompileUnit::emitHeader(const MCSymbol *ASectionSym) const {
705 // Don't bother labeling the .dwo unit, as its offset isn't used.
707 Asm->OutStreamer.EmitLabel(LabelBegin);
709 DwarfUnit::emitHeader(ASectionSym);
712 /// addGlobalName - Add a new global name to the compile unit.
713 void DwarfCompileUnit::addGlobalName(StringRef Name, DIE &Die,
715 if (includeMinimalInlineScopes())
717 std::string FullName = getParentContextString(Context) + Name.str();
718 GlobalNames[FullName] = &Die;
721 /// Add a new global type to the unit.
722 void DwarfCompileUnit::addGlobalType(DIType Ty, const DIE &Die,
724 if (includeMinimalInlineScopes())
726 std::string FullName = getParentContextString(Context) + Ty.getName().str();
727 GlobalTypes[FullName] = &Die;
730 /// addVariableAddress - Add DW_AT_location attribute for a
731 /// DbgVariable based on provided MachineLocation.
732 void DwarfCompileUnit::addVariableAddress(const DbgVariable &DV, DIE &Die,
733 MachineLocation Location) {
734 if (DV.variableHasComplexAddress())
735 addComplexAddress(DV, Die, dwarf::DW_AT_location, Location);
736 else if (DV.isBlockByrefVariable())
737 addBlockByrefAddress(DV, Die, dwarf::DW_AT_location, Location);
739 addAddress(Die, dwarf::DW_AT_location, Location,
740 DV.getVariable().isIndirect());
743 /// Add an address attribute to a die based on the location provided.
744 void DwarfCompileUnit::addAddress(DIE &Die, dwarf::Attribute Attribute,
745 const MachineLocation &Location,
747 DIELoc *Loc = new (DIEValueAllocator) DIELoc();
749 if (Location.isReg() && !Indirect)
750 addRegisterOpPiece(*Loc, Location.getReg());
752 addRegisterOffset(*Loc, Location.getReg(), Location.getOffset());
753 if (Indirect && !Location.isReg()) {
754 addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_deref);
758 // Now attach the location information to the DIE.
759 addBlock(Die, Attribute, Loc);
762 /// Start with the address based on the location provided, and generate the
763 /// DWARF information necessary to find the actual variable given the extra
764 /// address information encoded in the DbgVariable, starting from the starting
765 /// location. Add the DWARF information to the die.
766 void DwarfCompileUnit::addComplexAddress(const DbgVariable &DV, DIE &Die,
767 dwarf::Attribute Attribute,
768 const MachineLocation &Location) {
769 DIELoc *Loc = new (DIEValueAllocator) DIELoc();
770 unsigned N = DV.getNumAddrElements();
772 if (Location.isReg()) {
773 if (N >= 2 && DV.getAddrElement(0) == dwarf::DW_OP_plus) {
774 assert(!DV.getVariable().isIndirect() &&
775 "double indirection not handled");
776 // If first address element is OpPlus then emit
777 // DW_OP_breg + Offset instead of DW_OP_reg + Offset.
778 addRegisterOffset(*Loc, Location.getReg(), DV.getAddrElement(1));
780 } else if (N >= 2 && DV.getAddrElement(0) == dwarf::DW_OP_deref) {
781 assert(!DV.getVariable().isIndirect() &&
782 "double indirection not handled");
783 addRegisterOpPiece(*Loc, Location.getReg(),
784 DV.getExpression().getPieceSize(),
785 DV.getExpression().getPieceOffset());
788 addRegisterOpPiece(*Loc, Location.getReg());
790 addRegisterOffset(*Loc, Location.getReg(), Location.getOffset());
793 uint64_t Element = DV.getAddrElement(i);
794 if (Element == dwarf::DW_OP_plus) {
795 addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_plus_uconst);
796 addUInt(*Loc, dwarf::DW_FORM_udata, DV.getAddrElement(++i));
798 } else if (Element == dwarf::DW_OP_deref) {
799 if (!Location.isReg())
800 addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_deref);
802 } else if (Element == dwarf::DW_OP_piece) {
803 const unsigned SizeOfByte = 8;
804 unsigned PieceOffsetInBits = DV.getAddrElement(++i) * SizeOfByte;
805 unsigned PieceSizeInBits = DV.getAddrElement(++i) * SizeOfByte;
806 // Emit DW_OP_bit_piece Size Offset.
807 assert(PieceSizeInBits > 0 && "piece has zero size");
808 addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_bit_piece);
809 addUInt(*Loc, dwarf::DW_FORM_udata, PieceSizeInBits);
810 addUInt(*Loc, dwarf::DW_FORM_udata, PieceOffsetInBits);
812 llvm_unreachable("unknown DIBuilder Opcode");
815 // Now attach the location information to the DIE.
816 addBlock(Die, Attribute, Loc);
819 /// Add a Dwarf loclistptr attribute data and value.
820 void DwarfCompileUnit::addLocationList(DIE &Die, dwarf::Attribute Attribute,
822 DIEValue *Value = new (DIEValueAllocator) DIELocList(Index);
823 dwarf::Form Form = DD->getDwarfVersion() >= 4 ? dwarf::DW_FORM_sec_offset
824 : dwarf::DW_FORM_data4;
825 Die.addValue(Attribute, Form, Value);
828 void DwarfCompileUnit::applyVariableAttributes(const DbgVariable &Var,
830 StringRef Name = Var.getName();
832 addString(VariableDie, dwarf::DW_AT_name, Name);
833 addSourceLine(VariableDie, Var.getVariable());
834 addType(VariableDie, Var.getType());
835 if (Var.isArtificial())
836 addFlag(VariableDie, dwarf::DW_AT_artificial);
839 /// Add a Dwarf expression attribute data and value.
840 void DwarfCompileUnit::addExpr(DIELoc &Die, dwarf::Form Form,
841 const MCExpr *Expr) {
842 DIEValue *Value = new (DIEValueAllocator) DIEExpr(Expr);
843 Die.addValue((dwarf::Attribute)0, Form, Value);
846 void DwarfCompileUnit::applySubprogramAttributesToDefinition(DISubprogram SP,
848 DISubprogram SPDecl = SP.getFunctionDeclaration();
849 DIScope Context = resolve(SPDecl ? SPDecl.getContext() : SP.getContext());
850 applySubprogramAttributes(SP, SPDie, includeMinimalInlineScopes());
851 addGlobalName(SP.getName(), SPDie, Context);
854 bool DwarfCompileUnit::isDwoUnit() const {
855 return DD->useSplitDwarf() && Skeleton;
858 bool DwarfCompileUnit::includeMinimalInlineScopes() const {
859 return getCUNode().getEmissionKind() == DIBuilder::LineTablesOnly ||
860 (DD->useSplitDwarf() && !Skeleton);
862 } // end llvm namespace