1 #include "DwarfCompileUnit.h"
3 #include "DwarfExpression.h"
4 #include "llvm/CodeGen/MachineFunction.h"
5 #include "llvm/IR/DataLayout.h"
6 #include "llvm/IR/GlobalValue.h"
7 #include "llvm/IR/GlobalVariable.h"
8 #include "llvm/IR/Instruction.h"
9 #include "llvm/MC/MCAsmInfo.h"
10 #include "llvm/MC/MCStreamer.h"
11 #include "llvm/Target/TargetFrameLowering.h"
12 #include "llvm/Target/TargetLoweringObjectFile.h"
13 #include "llvm/Target/TargetMachine.h"
14 #include "llvm/Target/TargetSubtargetInfo.h"
15 #include "llvm/Target/TargetRegisterInfo.h"
19 DwarfCompileUnit::DwarfCompileUnit(unsigned UID, DICompileUnit Node,
20 AsmPrinter *A, DwarfDebug *DW,
22 : DwarfUnit(UID, dwarf::DW_TAG_compile_unit, Node, A, DW, DWU),
23 Skeleton(nullptr), LabelBegin(nullptr), BaseAddress(nullptr) {
24 insertDIE(Node, &getUnitDie());
27 /// addLabelAddress - Add a dwarf label attribute data and value using
28 /// DW_FORM_addr or DW_FORM_GNU_addr_index.
30 void DwarfCompileUnit::addLabelAddress(DIE &Die, dwarf::Attribute Attribute,
31 const MCSymbol *Label) {
33 // Don't use the address pool in non-fission or in the skeleton unit itself.
34 // FIXME: Once GDB supports this, it's probably worthwhile using the address
35 // pool from the skeleton - maybe even in non-fission (possibly fewer
36 // relocations by sharing them in the pool, but we have other ideas about how
37 // to reduce the number of relocations as well/instead).
38 if (!DD->useSplitDwarf() || !Skeleton)
39 return addLocalLabelAddress(Die, Attribute, Label);
42 DD->addArangeLabel(SymbolCU(this, Label));
44 unsigned idx = DD->getAddressPool().getIndex(Label);
45 DIEValue *Value = new (DIEValueAllocator) DIEInteger(idx);
46 Die.addValue(Attribute, dwarf::DW_FORM_GNU_addr_index, Value);
49 void DwarfCompileUnit::addLocalLabelAddress(DIE &Die,
50 dwarf::Attribute Attribute,
51 const MCSymbol *Label) {
53 DD->addArangeLabel(SymbolCU(this, Label));
55 Die.addValue(Attribute, dwarf::DW_FORM_addr,
56 Label ? (DIEValue *)new (DIEValueAllocator) DIELabel(Label)
57 : new (DIEValueAllocator) DIEInteger(0));
60 unsigned DwarfCompileUnit::getOrCreateSourceID(StringRef FileName,
62 // If we print assembly, we can't separate .file entries according to
63 // compile units. Thus all files will belong to the default compile unit.
65 // FIXME: add a better feature test than hasRawTextSupport. Even better,
66 // extend .file to support this.
67 return Asm->OutStreamer.EmitDwarfFileDirective(
69 Asm->OutStreamer.hasRawTextSupport() ? 0 : getUniqueID());
72 // Return const expression if value is a GEP to access merged global
74 // i8* getelementptr ({ i8, i8, i8, i8 }* @_MergedGlobals, i32 0, i32 0)
75 static const ConstantExpr *getMergedGlobalExpr(const Value *V) {
76 const ConstantExpr *CE = dyn_cast_or_null<ConstantExpr>(V);
77 if (!CE || CE->getNumOperands() != 3 ||
78 CE->getOpcode() != Instruction::GetElementPtr)
81 // First operand points to a global struct.
82 Value *Ptr = CE->getOperand(0);
83 if (!isa<GlobalValue>(Ptr) ||
84 !isa<StructType>(cast<PointerType>(Ptr->getType())->getElementType()))
87 // Second operand is zero.
88 const ConstantInt *CI = dyn_cast_or_null<ConstantInt>(CE->getOperand(1));
89 if (!CI || !CI->isZero())
92 // Third operand is offset.
93 if (!isa<ConstantInt>(CE->getOperand(2)))
99 /// getOrCreateGlobalVariableDIE - get or create global variable DIE.
100 DIE *DwarfCompileUnit::getOrCreateGlobalVariableDIE(DIGlobalVariable GV) {
101 // Check for pre-existence.
102 if (DIE *Die = getDIE(GV))
105 assert(GV.isGlobalVariable());
107 DIScope GVContext = GV.getContext();
108 DIType GTy = DD->resolve(GV.getType());
110 // Construct the context before querying for the existence of the DIE in
111 // case such construction creates the DIE.
112 DIE *ContextDIE = getOrCreateContextDIE(GVContext);
115 DIE *VariableDIE = &createAndAddDIE(GV.getTag(), *ContextDIE, GV);
118 if (DIDerivedType SDMDecl = GV.getStaticDataMemberDeclaration()) {
119 DeclContext = resolve(SDMDecl.getContext());
120 assert(SDMDecl.isStaticMember() && "Expected static member decl");
121 assert(GV.isDefinition());
122 // We need the declaration DIE that is in the static member's class.
123 DIE *VariableSpecDIE = getOrCreateStaticMemberDIE(SDMDecl);
124 addDIEEntry(*VariableDIE, dwarf::DW_AT_specification, *VariableSpecDIE);
126 DeclContext = GV.getContext();
127 // Add name and type.
128 addString(*VariableDIE, dwarf::DW_AT_name, GV.getDisplayName());
129 addType(*VariableDIE, GTy);
132 if (!GV.isLocalToUnit())
133 addFlag(*VariableDIE, dwarf::DW_AT_external);
135 // Add line number info.
136 addSourceLine(*VariableDIE, GV);
139 if (!GV.isDefinition())
140 addFlag(*VariableDIE, dwarf::DW_AT_declaration);
143 bool addToAccelTable = false;
144 bool isGlobalVariable = GV.getGlobal() != nullptr;
145 if (isGlobalVariable) {
146 addToAccelTable = true;
147 DIELoc *Loc = new (DIEValueAllocator) DIELoc();
148 const MCSymbol *Sym = Asm->getSymbol(GV.getGlobal());
149 if (GV.getGlobal()->isThreadLocal()) {
150 // FIXME: Make this work with -gsplit-dwarf.
151 unsigned PointerSize = Asm->getDataLayout().getPointerSize();
152 assert((PointerSize == 4 || PointerSize == 8) &&
153 "Add support for other sizes if necessary");
154 // Based on GCC's support for TLS:
155 if (!DD->useSplitDwarf()) {
156 // 1) Start with a constNu of the appropriate pointer size
157 addUInt(*Loc, dwarf::DW_FORM_data1,
158 PointerSize == 4 ? dwarf::DW_OP_const4u : dwarf::DW_OP_const8u);
159 // 2) containing the (relocated) offset of the TLS variable
160 // within the module's TLS block.
161 addExpr(*Loc, dwarf::DW_FORM_udata,
162 Asm->getObjFileLowering().getDebugThreadLocalSymbol(Sym));
164 addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_GNU_const_index);
165 addUInt(*Loc, dwarf::DW_FORM_udata,
166 DD->getAddressPool().getIndex(Sym, /* TLS */ true));
168 // 3) followed by a custom OP to make the debugger do a TLS lookup.
169 addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_GNU_push_tls_address);
171 DD->addArangeLabel(SymbolCU(this, Sym));
172 addOpAddress(*Loc, Sym);
175 addBlock(*VariableDIE, dwarf::DW_AT_location, Loc);
176 // Add the linkage name.
177 StringRef LinkageName = GV.getLinkageName();
178 if (!LinkageName.empty())
179 // From DWARF4: DIEs to which DW_AT_linkage_name may apply include:
180 // TAG_common_block, TAG_constant, TAG_entry_point, TAG_subprogram and
182 addString(*VariableDIE,
183 DD->getDwarfVersion() >= 4 ? dwarf::DW_AT_linkage_name
184 : dwarf::DW_AT_MIPS_linkage_name,
185 GlobalValue::getRealLinkageName(LinkageName));
186 } else if (const ConstantInt *CI =
187 dyn_cast_or_null<ConstantInt>(GV.getConstant())) {
188 addConstantValue(*VariableDIE, CI, GTy);
189 } else if (const ConstantExpr *CE = getMergedGlobalExpr(GV.getConstant())) {
190 addToAccelTable = true;
191 // GV is a merged global.
192 DIELoc *Loc = new (DIEValueAllocator) DIELoc();
193 Value *Ptr = CE->getOperand(0);
194 MCSymbol *Sym = Asm->getSymbol(cast<GlobalValue>(Ptr));
195 DD->addArangeLabel(SymbolCU(this, Sym));
196 addOpAddress(*Loc, Sym);
197 addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_constu);
198 SmallVector<Value *, 3> Idx(CE->op_begin() + 1, CE->op_end());
199 addUInt(*Loc, dwarf::DW_FORM_udata,
200 Asm->getDataLayout().getIndexedOffset(Ptr->getType(), Idx));
201 addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_plus);
202 addBlock(*VariableDIE, dwarf::DW_AT_location, Loc);
205 if (addToAccelTable) {
206 DD->addAccelName(GV.getName(), *VariableDIE);
208 // If the linkage name is different than the name, go ahead and output
209 // that as well into the name table.
210 if (GV.getLinkageName() != "" && GV.getName() != GV.getLinkageName())
211 DD->addAccelName(GV.getLinkageName(), *VariableDIE);
214 addGlobalName(GV.getName(), *VariableDIE, DeclContext);
218 void DwarfCompileUnit::addRange(RangeSpan Range) {
219 bool SameAsPrevCU = this == DD->getPrevCU();
221 // If we have no current ranges just add the range and return, otherwise,
222 // check the current section and CU against the previous section and CU we
223 // emitted into and the subprogram was contained within. If these are the
224 // same then extend our current range, otherwise add this as a new range.
225 if (CURanges.empty() || !SameAsPrevCU ||
226 (&CURanges.back().getEnd()->getSection() !=
227 &Range.getEnd()->getSection())) {
228 CURanges.push_back(Range);
232 CURanges.back().setEnd(Range.getEnd());
235 void DwarfCompileUnit::addSectionLabel(DIE &Die, dwarf::Attribute Attribute,
236 const MCSymbol *Label,
237 const MCSymbol *Sec) {
238 if (Asm->MAI->doesDwarfUseRelocationsAcrossSections())
239 addLabel(Die, Attribute,
240 DD->getDwarfVersion() >= 4 ? dwarf::DW_FORM_sec_offset
241 : dwarf::DW_FORM_data4,
244 addSectionDelta(Die, Attribute, Label, Sec);
247 void DwarfCompileUnit::initStmtList(MCSymbol *DwarfLineSectionSym) {
248 // Define start line table label for each Compile Unit.
249 MCSymbol *LineTableStartSym =
250 Asm->OutStreamer.getDwarfLineTableSymbol(getUniqueID());
252 stmtListIndex = UnitDie.getValues().size();
254 // DW_AT_stmt_list is a offset of line number information for this
255 // compile unit in debug_line section. For split dwarf this is
256 // left in the skeleton CU and so not included.
257 // The line table entries are not always emitted in assembly, so it
258 // is not okay to use line_table_start here.
259 addSectionLabel(UnitDie, dwarf::DW_AT_stmt_list, LineTableStartSym,
260 DwarfLineSectionSym);
263 void DwarfCompileUnit::applyStmtList(DIE &D) {
264 D.addValue(dwarf::DW_AT_stmt_list,
265 UnitDie.getAbbrev().getData()[stmtListIndex].getForm(),
266 UnitDie.getValues()[stmtListIndex]);
269 void DwarfCompileUnit::attachLowHighPC(DIE &D, const MCSymbol *Begin,
270 const MCSymbol *End) {
271 assert(Begin && "Begin label should not be null!");
272 assert(End && "End label should not be null!");
273 assert(Begin->isDefined() && "Invalid starting label");
274 assert(End->isDefined() && "Invalid end label");
276 addLabelAddress(D, dwarf::DW_AT_low_pc, Begin);
277 if (DD->getDwarfVersion() < 4)
278 addLabelAddress(D, dwarf::DW_AT_high_pc, End);
280 addLabelDelta(D, dwarf::DW_AT_high_pc, End, Begin);
283 // Find DIE for the given subprogram and attach appropriate DW_AT_low_pc
284 // and DW_AT_high_pc attributes. If there are global variables in this
285 // scope then create and insert DIEs for these variables.
286 DIE &DwarfCompileUnit::updateSubprogramScopeDIE(DISubprogram SP) {
287 DIE *SPDie = getOrCreateSubprogramDIE(SP, includeMinimalInlineScopes());
289 attachLowHighPC(*SPDie, DD->getFunctionBeginSym(), DD->getFunctionEndSym());
290 if (!DD->getCurrentFunction()->getTarget().Options.DisableFramePointerElim(
291 *DD->getCurrentFunction()))
292 addFlag(*SPDie, dwarf::DW_AT_APPLE_omit_frame_ptr);
294 // Only include DW_AT_frame_base in full debug info
295 if (!includeMinimalInlineScopes()) {
296 const TargetRegisterInfo *RI =
297 Asm->TM.getSubtargetImpl()->getRegisterInfo();
298 MachineLocation Location(RI->getFrameRegister(*Asm->MF));
299 if (RI->isPhysicalRegister(Location.getReg()))
300 addAddress(*SPDie, dwarf::DW_AT_frame_base, Location);
303 // Add name to the name table, we do this here because we're guaranteed
304 // to have concrete versions of our DW_TAG_subprogram nodes.
305 DD->addSubprogramNames(SP, *SPDie);
310 // Construct a DIE for this scope.
311 void DwarfCompileUnit::constructScopeDIE(
312 LexicalScope *Scope, SmallVectorImpl<std::unique_ptr<DIE>> &FinalChildren) {
313 if (!Scope || !Scope->getScopeNode())
316 DIScope DS(Scope->getScopeNode());
318 assert((Scope->getInlinedAt() || !DS.isSubprogram()) &&
319 "Only handle inlined subprograms here, use "
320 "constructSubprogramScopeDIE for non-inlined "
323 SmallVector<std::unique_ptr<DIE>, 8> Children;
325 // We try to create the scope DIE first, then the children DIEs. This will
326 // avoid creating un-used children then removing them later when we find out
327 // the scope DIE is null.
328 std::unique_ptr<DIE> ScopeDIE;
329 if (Scope->getParent() && DS.isSubprogram()) {
330 ScopeDIE = constructInlinedScopeDIE(Scope);
333 // We create children when the scope DIE is not null.
334 createScopeChildrenDIE(Scope, Children);
336 // Early exit when we know the scope DIE is going to be null.
337 if (DD->isLexicalScopeDIENull(Scope))
340 unsigned ChildScopeCount;
342 // We create children here when we know the scope DIE is not going to be
343 // null and the children will be added to the scope DIE.
344 createScopeChildrenDIE(Scope, Children, &ChildScopeCount);
346 // Skip imported directives in gmlt-like data.
347 if (!includeMinimalInlineScopes()) {
348 // There is no need to emit empty lexical block DIE.
349 for (const auto &E : DD->findImportedEntitiesForScope(DS))
351 constructImportedEntityDIE(DIImportedEntity(E.second)));
354 // If there are only other scopes as children, put them directly in the
355 // parent instead, as this scope would serve no purpose.
356 if (Children.size() == ChildScopeCount) {
357 FinalChildren.insert(FinalChildren.end(),
358 std::make_move_iterator(Children.begin()),
359 std::make_move_iterator(Children.end()));
362 ScopeDIE = constructLexicalScopeDIE(Scope);
363 assert(ScopeDIE && "Scope DIE should not be null.");
367 for (auto &I : Children)
368 ScopeDIE->addChild(std::move(I));
370 FinalChildren.push_back(std::move(ScopeDIE));
373 void DwarfCompileUnit::addSectionDelta(DIE &Die, dwarf::Attribute Attribute,
374 const MCSymbol *Hi, const MCSymbol *Lo) {
375 DIEValue *Value = new (DIEValueAllocator) DIEDelta(Hi, Lo);
376 Die.addValue(Attribute, DD->getDwarfVersion() >= 4 ? dwarf::DW_FORM_sec_offset
377 : dwarf::DW_FORM_data4,
381 void DwarfCompileUnit::addScopeRangeList(DIE &ScopeDIE,
382 SmallVector<RangeSpan, 2> Range) {
383 // Emit offset in .debug_range as a relocatable label. emitDIE will handle
384 // emitting it appropriately.
385 auto *RangeSectionSym = DD->getRangeSectionSym();
388 Asm->GetTempSymbol("debug_ranges", DD->getNextRangeNumber()),
391 // Under fission, ranges are specified by constant offsets relative to the
392 // CU's DW_AT_GNU_ranges_base.
394 addSectionDelta(ScopeDIE, dwarf::DW_AT_ranges, List.getSym(),
397 addSectionLabel(ScopeDIE, dwarf::DW_AT_ranges, List.getSym(),
400 // Add the range list to the set of ranges to be emitted.
401 (Skeleton ? Skeleton : this)->CURangeLists.push_back(std::move(List));
404 void DwarfCompileUnit::attachRangesOrLowHighPC(
405 DIE &Die, SmallVector<RangeSpan, 2> Ranges) {
406 if (Ranges.size() == 1) {
407 const auto &single = Ranges.front();
408 attachLowHighPC(Die, single.getStart(), single.getEnd());
410 addScopeRangeList(Die, std::move(Ranges));
413 void DwarfCompileUnit::attachRangesOrLowHighPC(
414 DIE &Die, const SmallVectorImpl<InsnRange> &Ranges) {
415 SmallVector<RangeSpan, 2> List;
416 List.reserve(Ranges.size());
417 for (const InsnRange &R : Ranges)
418 List.push_back(RangeSpan(DD->getLabelBeforeInsn(R.first),
419 DD->getLabelAfterInsn(R.second)));
420 attachRangesOrLowHighPC(Die, std::move(List));
423 // This scope represents inlined body of a function. Construct DIE to
424 // represent this concrete inlined copy of the function.
426 DwarfCompileUnit::constructInlinedScopeDIE(LexicalScope *Scope) {
427 assert(Scope->getScopeNode());
428 DIScope DS(Scope->getScopeNode());
429 DISubprogram InlinedSP = getDISubprogram(DS);
430 // Find the subprogram's DwarfCompileUnit in the SPMap in case the subprogram
431 // was inlined from another compile unit.
432 DIE *OriginDIE = DU->getAbstractSPDies()[InlinedSP];
433 assert(OriginDIE && "Unable to find original DIE for an inlined subprogram.");
435 auto ScopeDIE = make_unique<DIE>(dwarf::DW_TAG_inlined_subroutine);
436 addDIEEntry(*ScopeDIE, dwarf::DW_AT_abstract_origin, *OriginDIE);
438 attachRangesOrLowHighPC(*ScopeDIE, Scope->getRanges());
440 // Add the call site information to the DIE.
441 DILocation DL(Scope->getInlinedAt());
442 addUInt(*ScopeDIE, dwarf::DW_AT_call_file, None,
443 getOrCreateSourceID(DL.getFilename(), DL.getDirectory()));
444 addUInt(*ScopeDIE, dwarf::DW_AT_call_line, None, DL.getLineNumber());
446 // Add name to the name table, we do this here because we're guaranteed
447 // to have concrete versions of our DW_TAG_inlined_subprogram nodes.
448 DD->addSubprogramNames(InlinedSP, *ScopeDIE);
453 // Construct new DW_TAG_lexical_block for this scope and attach
454 // DW_AT_low_pc/DW_AT_high_pc labels.
456 DwarfCompileUnit::constructLexicalScopeDIE(LexicalScope *Scope) {
457 if (DD->isLexicalScopeDIENull(Scope))
460 auto ScopeDIE = make_unique<DIE>(dwarf::DW_TAG_lexical_block);
461 if (Scope->isAbstractScope())
464 attachRangesOrLowHighPC(*ScopeDIE, Scope->getRanges());
469 /// constructVariableDIE - Construct a DIE for the given DbgVariable.
470 std::unique_ptr<DIE> DwarfCompileUnit::constructVariableDIE(DbgVariable &DV,
472 auto D = constructVariableDIEImpl(DV, Abstract);
478 DwarfCompileUnit::constructVariableDIEImpl(const DbgVariable &DV,
480 // Define variable debug information entry.
481 auto VariableDie = make_unique<DIE>(DV.getTag());
484 applyVariableAttributes(DV, *VariableDie);
488 // Add variable address.
490 unsigned Offset = DV.getDotDebugLocOffset();
492 addLocationList(*VariableDie, dwarf::DW_AT_location, Offset);
496 // Check if variable is described by a DBG_VALUE instruction.
497 if (const MachineInstr *DVInsn = DV.getMInsn()) {
498 assert(DVInsn->getNumOperands() == 4);
499 if (DVInsn->getOperand(0).isReg()) {
500 const MachineOperand RegOp = DVInsn->getOperand(0);
501 // If the second operand is an immediate, this is an indirect value.
502 if (DVInsn->getOperand(1).isImm()) {
503 MachineLocation Location(RegOp.getReg(),
504 DVInsn->getOperand(1).getImm());
505 addVariableAddress(DV, *VariableDie, Location);
506 } else if (RegOp.getReg())
507 addVariableAddress(DV, *VariableDie, MachineLocation(RegOp.getReg()));
508 } else if (DVInsn->getOperand(0).isImm())
509 addConstantValue(*VariableDie, DVInsn->getOperand(0), DV.getType());
510 else if (DVInsn->getOperand(0).isFPImm())
511 addConstantFPValue(*VariableDie, DVInsn->getOperand(0));
512 else if (DVInsn->getOperand(0).isCImm())
513 addConstantValue(*VariableDie, DVInsn->getOperand(0).getCImm(),
519 // .. else use frame index.
520 int FI = DV.getFrameIndex();
522 unsigned FrameReg = 0;
523 const TargetFrameLowering *TFI =
524 Asm->TM.getSubtargetImpl()->getFrameLowering();
525 int Offset = TFI->getFrameIndexReference(*Asm->MF, FI, FrameReg);
526 MachineLocation Location(FrameReg, Offset);
527 addVariableAddress(DV, *VariableDie, Location);
533 std::unique_ptr<DIE> DwarfCompileUnit::constructVariableDIE(
534 DbgVariable &DV, const LexicalScope &Scope, DIE *&ObjectPointer) {
535 auto Var = constructVariableDIE(DV, Scope.isAbstractScope());
536 if (DV.isObjectPointer())
537 ObjectPointer = Var.get();
541 DIE *DwarfCompileUnit::createScopeChildrenDIE(
542 LexicalScope *Scope, SmallVectorImpl<std::unique_ptr<DIE>> &Children,
543 unsigned *ChildScopeCount) {
544 DIE *ObjectPointer = nullptr;
546 for (DbgVariable *DV : DU->getScopeVariables().lookup(Scope))
547 Children.push_back(constructVariableDIE(*DV, *Scope, ObjectPointer));
549 unsigned ChildCountWithoutScopes = Children.size();
551 for (LexicalScope *LS : Scope->getChildren())
552 constructScopeDIE(LS, Children);
555 *ChildScopeCount = Children.size() - ChildCountWithoutScopes;
557 return ObjectPointer;
560 void DwarfCompileUnit::constructSubprogramScopeDIE(LexicalScope *Scope) {
561 assert(Scope && Scope->getScopeNode());
562 assert(!Scope->getInlinedAt());
563 assert(!Scope->isAbstractScope());
564 DISubprogram Sub(Scope->getScopeNode());
566 assert(Sub.isSubprogram());
568 DD->getProcessedSPNodes().insert(Sub);
570 DIE &ScopeDIE = updateSubprogramScopeDIE(Sub);
572 // If this is a variadic function, add an unspecified parameter.
573 DITypeArray FnArgs = Sub.getType().getTypeArray();
575 // Collect lexical scope children first.
576 // ObjectPointer might be a local (non-argument) local variable if it's a
577 // block's synthetic this pointer.
578 if (DIE *ObjectPointer = createAndAddScopeChildren(Scope, ScopeDIE))
579 addDIEEntry(ScopeDIE, dwarf::DW_AT_object_pointer, *ObjectPointer);
581 // If we have a single element of null, it is a function that returns void.
582 // If we have more than one elements and the last one is null, it is a
583 // variadic function.
584 if (FnArgs.getNumElements() > 1 &&
585 !FnArgs.getElement(FnArgs.getNumElements() - 1) &&
586 !includeMinimalInlineScopes())
587 ScopeDIE.addChild(make_unique<DIE>(dwarf::DW_TAG_unspecified_parameters));
590 DIE *DwarfCompileUnit::createAndAddScopeChildren(LexicalScope *Scope,
592 // We create children when the scope DIE is not null.
593 SmallVector<std::unique_ptr<DIE>, 8> Children;
594 DIE *ObjectPointer = createScopeChildrenDIE(Scope, Children);
597 for (auto &I : Children)
598 ScopeDIE.addChild(std::move(I));
600 return ObjectPointer;
604 DwarfCompileUnit::constructAbstractSubprogramScopeDIE(LexicalScope *Scope) {
605 DIE *&AbsDef = DU->getAbstractSPDies()[Scope->getScopeNode()];
609 DISubprogram SP(Scope->getScopeNode());
613 if (includeMinimalInlineScopes())
614 ContextDIE = &getUnitDie();
615 // Some of this is duplicated from DwarfUnit::getOrCreateSubprogramDIE, with
616 // the important distinction that the DIDescriptor is not associated with the
617 // DIE (since the DIDescriptor will be associated with the concrete DIE, if
618 // any). It could be refactored to some common utility function.
619 else if (DISubprogram SPDecl = SP.getFunctionDeclaration()) {
620 ContextDIE = &getUnitDie();
621 getOrCreateSubprogramDIE(SPDecl);
623 ContextDIE = getOrCreateContextDIE(resolve(SP.getContext()));
625 // Passing null as the associated DIDescriptor because the abstract definition
626 // shouldn't be found by lookup.
628 &createAndAddDIE(dwarf::DW_TAG_subprogram, *ContextDIE, DIDescriptor());
629 applySubprogramAttributesToDefinition(SP, *AbsDef);
631 if (!includeMinimalInlineScopes())
632 addUInt(*AbsDef, dwarf::DW_AT_inline, None, dwarf::DW_INL_inlined);
633 if (DIE *ObjectPointer = createAndAddScopeChildren(Scope, *AbsDef))
634 addDIEEntry(*AbsDef, dwarf::DW_AT_object_pointer, *ObjectPointer);
638 DwarfCompileUnit::constructImportedEntityDIE(const DIImportedEntity &Module) {
639 assert(Module.Verify() &&
640 "Use one of the MDNode * overloads to handle invalid metadata");
641 std::unique_ptr<DIE> IMDie = make_unique<DIE>((dwarf::Tag)Module.getTag());
642 insertDIE(Module, IMDie.get());
644 DIDescriptor Entity = resolve(Module.getEntity());
645 if (Entity.isNameSpace())
646 EntityDie = getOrCreateNameSpace(DINameSpace(Entity));
647 else if (Entity.isSubprogram())
648 EntityDie = getOrCreateSubprogramDIE(DISubprogram(Entity));
649 else if (Entity.isType())
650 EntityDie = getOrCreateTypeDIE(DIType(Entity));
651 else if (Entity.isGlobalVariable())
652 EntityDie = getOrCreateGlobalVariableDIE(DIGlobalVariable(Entity));
654 EntityDie = getDIE(Entity);
656 addSourceLine(*IMDie, Module.getLineNumber(),
657 Module.getContext().getFilename(),
658 Module.getContext().getDirectory());
659 addDIEEntry(*IMDie, dwarf::DW_AT_import, *EntityDie);
660 StringRef Name = Module.getName();
662 addString(*IMDie, dwarf::DW_AT_name, Name);
667 void DwarfCompileUnit::finishSubprogramDefinition(DISubprogram SP) {
669 if (DIE *AbsSPDIE = DU->getAbstractSPDies().lookup(SP)) {
671 // If this subprogram has an abstract definition, reference that
672 addDIEEntry(*D, dwarf::DW_AT_abstract_origin, *AbsSPDIE);
674 if (!D && !includeMinimalInlineScopes())
675 // Lazily construct the subprogram if we didn't see either concrete or
676 // inlined versions during codegen. (except in -gmlt ^ where we want
677 // to omit these entirely)
678 D = getOrCreateSubprogramDIE(SP);
680 // And attach the attributes
681 applySubprogramAttributesToDefinition(SP, *D);
684 void DwarfCompileUnit::collectDeadVariables(DISubprogram SP) {
685 assert(SP.isSubprogram() && "CU's subprogram list contains a non-subprogram");
686 assert(SP.isDefinition() &&
687 "CU's subprogram list contains a subprogram declaration");
688 DIArray Variables = SP.getVariables();
689 if (Variables.getNumElements() == 0)
692 DIE *SPDIE = DU->getAbstractSPDies().lookup(SP);
696 for (unsigned vi = 0, ve = Variables.getNumElements(); vi != ve; ++vi) {
697 DIVariable DV(Variables.getElement(vi));
698 assert(DV.isVariable());
699 DbgVariable NewVar(DV, DIExpression(nullptr), DD);
700 auto VariableDie = constructVariableDIE(NewVar);
701 applyVariableAttributes(NewVar, *VariableDie);
702 SPDIE->addChild(std::move(VariableDie));
706 void DwarfCompileUnit::emitHeader(const MCSymbol *ASectionSym) const {
707 // Don't bother labeling the .dwo unit, as its offset isn't used.
709 Asm->OutStreamer.EmitLabel(LabelBegin);
711 DwarfUnit::emitHeader(ASectionSym);
714 /// addGlobalName - Add a new global name to the compile unit.
715 void DwarfCompileUnit::addGlobalName(StringRef Name, DIE &Die,
717 if (includeMinimalInlineScopes())
719 std::string FullName = getParentContextString(Context) + Name.str();
720 GlobalNames[FullName] = &Die;
723 /// Add a new global type to the unit.
724 void DwarfCompileUnit::addGlobalType(DIType Ty, const DIE &Die,
726 if (includeMinimalInlineScopes())
728 std::string FullName = getParentContextString(Context) + Ty.getName().str();
729 GlobalTypes[FullName] = &Die;
732 /// addVariableAddress - Add DW_AT_location attribute for a
733 /// DbgVariable based on provided MachineLocation.
734 void DwarfCompileUnit::addVariableAddress(const DbgVariable &DV, DIE &Die,
735 MachineLocation Location) {
736 if (DV.variableHasComplexAddress())
737 addComplexAddress(DV, Die, dwarf::DW_AT_location, Location);
738 else if (DV.isBlockByrefVariable())
739 addBlockByrefAddress(DV, Die, dwarf::DW_AT_location, Location);
741 addAddress(Die, dwarf::DW_AT_location, Location,
742 DV.getVariable().isIndirect());
745 /// Add an address attribute to a die based on the location provided.
746 void DwarfCompileUnit::addAddress(DIE &Die, dwarf::Attribute Attribute,
747 const MachineLocation &Location,
749 DIELoc *Loc = new (DIEValueAllocator) DIELoc();
752 if (Location.isReg() && !Indirect)
753 validReg = addRegisterOpPiece(*Loc, Location.getReg());
755 validReg = addRegisterOffset(*Loc, Location.getReg(), Location.getOffset());
760 if (!Location.isReg() && Indirect)
761 addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_deref);
763 // Now attach the location information to the DIE.
764 addBlock(Die, Attribute, Loc);
767 /// Start with the address based on the location provided, and generate the
768 /// DWARF information necessary to find the actual variable given the extra
769 /// address information encoded in the DbgVariable, starting from the starting
770 /// location. Add the DWARF information to the die.
771 void DwarfCompileUnit::addComplexAddress(const DbgVariable &DV, DIE &Die,
772 dwarf::Attribute Attribute,
773 const MachineLocation &Location) {
774 DIELoc *Loc = new (DIEValueAllocator) DIELoc();
775 DIEDwarfExpression DwarfExpr(*Asm, *this, *Loc);
776 DIExpression Expr = DV.getExpression();
777 if (Location.getOffset()) {
778 if (DwarfExpr.AddMachineRegIndirect(Location.getReg(),
779 Location.getOffset())) {
780 DwarfExpr.AddExpression(Expr);
781 assert(!DV.getVariable().isIndirect()
782 && "double indirection not handled");
785 if (DwarfExpr.AddMachineRegExpression(Expr, Location.getReg()))
786 if (DV.getVariable().isIndirect())
787 DwarfExpr.EmitOp(dwarf::DW_OP_deref);
790 // Now attach the location information to the DIE.
791 addBlock(Die, Attribute, Loc);
794 /// Add a Dwarf loclistptr attribute data and value.
795 void DwarfCompileUnit::addLocationList(DIE &Die, dwarf::Attribute Attribute,
797 DIEValue *Value = new (DIEValueAllocator) DIELocList(Index);
798 dwarf::Form Form = DD->getDwarfVersion() >= 4 ? dwarf::DW_FORM_sec_offset
799 : dwarf::DW_FORM_data4;
800 Die.addValue(Attribute, Form, Value);
803 void DwarfCompileUnit::applyVariableAttributes(const DbgVariable &Var,
805 StringRef Name = Var.getName();
807 addString(VariableDie, dwarf::DW_AT_name, Name);
808 addSourceLine(VariableDie, Var.getVariable());
809 addType(VariableDie, Var.getType());
810 if (Var.isArtificial())
811 addFlag(VariableDie, dwarf::DW_AT_artificial);
814 /// Add a Dwarf expression attribute data and value.
815 void DwarfCompileUnit::addExpr(DIELoc &Die, dwarf::Form Form,
816 const MCExpr *Expr) {
817 DIEValue *Value = new (DIEValueAllocator) DIEExpr(Expr);
818 Die.addValue((dwarf::Attribute)0, Form, Value);
821 void DwarfCompileUnit::applySubprogramAttributesToDefinition(DISubprogram SP,
823 DISubprogram SPDecl = SP.getFunctionDeclaration();
824 DIScope Context = resolve(SPDecl ? SPDecl.getContext() : SP.getContext());
825 applySubprogramAttributes(SP, SPDie, includeMinimalInlineScopes());
826 addGlobalName(SP.getName(), SPDie, Context);
829 bool DwarfCompileUnit::isDwoUnit() const {
830 return DD->useSplitDwarf() && Skeleton;
833 bool DwarfCompileUnit::includeMinimalInlineScopes() const {
834 return getCUNode().getEmissionKind() == DIBuilder::LineTablesOnly ||
835 (DD->useSplitDwarf() && !Skeleton);
837 } // end llvm namespace