1 #include "DwarfCompileUnit.h"
2 #include "DwarfExpression.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/TargetRegisterInfo.h"
14 #include "llvm/Target/TargetSubtargetInfo.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 = 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 = 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 an OP to make the debugger do a TLS lookup.
168 addUInt(*Loc, dwarf::DW_FORM_data1,
169 DD->useGNUTLSOpcode() ? dwarf::DW_OP_GNU_push_tls_address
170 : dwarf::DW_OP_form_tls_address);
172 DD->addArangeLabel(SymbolCU(this, Sym));
173 addOpAddress(*Loc, Sym);
176 addBlock(*VariableDIE, dwarf::DW_AT_location, Loc);
177 // Add the linkage name.
178 StringRef LinkageName = GV.getLinkageName();
179 if (!LinkageName.empty())
180 // From DWARF4: DIEs to which DW_AT_linkage_name may apply include:
181 // TAG_common_block, TAG_constant, TAG_entry_point, TAG_subprogram and
183 addString(*VariableDIE,
184 DD->getDwarfVersion() >= 4 ? dwarf::DW_AT_linkage_name
185 : dwarf::DW_AT_MIPS_linkage_name,
186 GlobalValue::getRealLinkageName(LinkageName));
187 } else if (const ConstantInt *CI =
188 dyn_cast_or_null<ConstantInt>(GV.getConstant())) {
189 addConstantValue(*VariableDIE, CI, GTy);
190 } else if (const ConstantExpr *CE = getMergedGlobalExpr(GV.getConstant())) {
191 addToAccelTable = true;
192 // GV is a merged global.
193 DIELoc *Loc = new (DIEValueAllocator) DIELoc();
194 Value *Ptr = CE->getOperand(0);
195 MCSymbol *Sym = Asm->getSymbol(cast<GlobalValue>(Ptr));
196 DD->addArangeLabel(SymbolCU(this, Sym));
197 addOpAddress(*Loc, Sym);
198 addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_constu);
199 SmallVector<Value *, 3> Idx(CE->op_begin() + 1, CE->op_end());
200 addUInt(*Loc, dwarf::DW_FORM_udata,
201 Asm->getDataLayout().getIndexedOffset(Ptr->getType(), Idx));
202 addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_plus);
203 addBlock(*VariableDIE, dwarf::DW_AT_location, Loc);
206 if (addToAccelTable) {
207 DD->addAccelName(GV.getName(), *VariableDIE);
209 // If the linkage name is different than the name, go ahead and output
210 // that as well into the name table.
211 if (GV.getLinkageName() != "" && GV.getName() != GV.getLinkageName())
212 DD->addAccelName(GV.getLinkageName(), *VariableDIE);
215 addGlobalName(GV.getName(), *VariableDIE, DeclContext);
219 void DwarfCompileUnit::addRange(RangeSpan Range) {
220 bool SameAsPrevCU = this == DD->getPrevCU();
222 // If we have no current ranges just add the range and return, otherwise,
223 // check the current section and CU against the previous section and CU we
224 // emitted into and the subprogram was contained within. If these are the
225 // same then extend our current range, otherwise add this as a new range.
226 if (CURanges.empty() || !SameAsPrevCU ||
227 (&CURanges.back().getEnd()->getSection() !=
228 &Range.getEnd()->getSection())) {
229 CURanges.push_back(Range);
233 CURanges.back().setEnd(Range.getEnd());
236 void DwarfCompileUnit::addSectionLabel(DIE &Die, dwarf::Attribute Attribute,
237 const MCSymbol *Label,
238 const MCSymbol *Sec) {
239 if (Asm->MAI->doesDwarfUseRelocationsAcrossSections())
240 addLabel(Die, Attribute,
241 DD->getDwarfVersion() >= 4 ? dwarf::DW_FORM_sec_offset
242 : dwarf::DW_FORM_data4,
245 addSectionDelta(Die, Attribute, Label, Sec);
248 void DwarfCompileUnit::initStmtList(MCSymbol *DwarfLineSectionSym) {
249 // Define start line table label for each Compile Unit.
250 MCSymbol *LineTableStartSym =
251 Asm->OutStreamer.getDwarfLineTableSymbol(getUniqueID());
253 stmtListIndex = UnitDie.getValues().size();
255 // DW_AT_stmt_list is a offset of line number information for this
256 // compile unit in debug_line section. For split dwarf this is
257 // left in the skeleton CU and so not included.
258 // The line table entries are not always emitted in assembly, so it
259 // is not okay to use line_table_start here.
260 addSectionLabel(UnitDie, dwarf::DW_AT_stmt_list, LineTableStartSym,
261 DwarfLineSectionSym);
264 void DwarfCompileUnit::applyStmtList(DIE &D) {
265 D.addValue(dwarf::DW_AT_stmt_list,
266 UnitDie.getAbbrev().getData()[stmtListIndex].getForm(),
267 UnitDie.getValues()[stmtListIndex]);
270 void DwarfCompileUnit::attachLowHighPC(DIE &D, const MCSymbol *Begin,
271 const MCSymbol *End) {
272 assert(Begin && "Begin label should not be null!");
273 assert(End && "End label should not be null!");
274 assert(Begin->isDefined() && "Invalid starting label");
275 assert(End->isDefined() && "Invalid end label");
277 addLabelAddress(D, dwarf::DW_AT_low_pc, Begin);
278 if (DD->getDwarfVersion() < 4)
279 addLabelAddress(D, dwarf::DW_AT_high_pc, End);
281 addLabelDelta(D, dwarf::DW_AT_high_pc, End, Begin);
284 // Find DIE for the given subprogram and attach appropriate DW_AT_low_pc
285 // and DW_AT_high_pc attributes. If there are global variables in this
286 // scope then create and insert DIEs for these variables.
287 DIE &DwarfCompileUnit::updateSubprogramScopeDIE(DISubprogram SP) {
288 DIE *SPDie = getOrCreateSubprogramDIE(SP, includeMinimalInlineScopes());
290 attachLowHighPC(*SPDie, DD->getFunctionBeginSym(), DD->getFunctionEndSym());
291 if (!DD->getCurrentFunction()->getTarget().Options.DisableFramePointerElim(
292 *DD->getCurrentFunction()))
293 addFlag(*SPDie, dwarf::DW_AT_APPLE_omit_frame_ptr);
295 // Only include DW_AT_frame_base in full debug info
296 if (!includeMinimalInlineScopes()) {
297 const TargetRegisterInfo *RI = Asm->MF->getSubtarget().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 if (DV.getFrameIndex().back() == ~0)
523 auto Expr = DV.getExpression().begin();
524 DIELoc *Loc = new (DIEValueAllocator) DIELoc();
525 DIEDwarfExpression DwarfExpr(*Asm, *this, *Loc);
526 for (auto FI : DV.getFrameIndex()) {
527 unsigned FrameReg = 0;
528 const TargetFrameLowering *TFI = Asm->MF->getSubtarget().getFrameLowering();
529 int Offset = TFI->getFrameIndexReference(*Asm->MF, FI, FrameReg);
530 assert(Expr != DV.getExpression().end() &&
531 "Wrong number of expressions");
532 DwarfExpr.AddMachineRegIndirect(FrameReg, Offset);
533 DwarfExpr.AddExpression(Expr->begin(), Expr->end());
536 addBlock(*VariableDie, dwarf::DW_AT_location, Loc);
541 std::unique_ptr<DIE> DwarfCompileUnit::constructVariableDIE(
542 DbgVariable &DV, const LexicalScope &Scope, DIE *&ObjectPointer) {
543 auto Var = constructVariableDIE(DV, Scope.isAbstractScope());
544 if (DV.isObjectPointer())
545 ObjectPointer = Var.get();
549 DIE *DwarfCompileUnit::createScopeChildrenDIE(
550 LexicalScope *Scope, SmallVectorImpl<std::unique_ptr<DIE>> &Children,
551 unsigned *ChildScopeCount) {
552 DIE *ObjectPointer = nullptr;
554 for (DbgVariable *DV : DU->getScopeVariables().lookup(Scope))
555 Children.push_back(constructVariableDIE(*DV, *Scope, ObjectPointer));
557 unsigned ChildCountWithoutScopes = Children.size();
559 for (LexicalScope *LS : Scope->getChildren())
560 constructScopeDIE(LS, Children);
563 *ChildScopeCount = Children.size() - ChildCountWithoutScopes;
565 return ObjectPointer;
568 void DwarfCompileUnit::constructSubprogramScopeDIE(LexicalScope *Scope) {
569 assert(Scope && Scope->getScopeNode());
570 assert(!Scope->getInlinedAt());
571 assert(!Scope->isAbstractScope());
572 DISubprogram Sub(Scope->getScopeNode());
574 assert(Sub.isSubprogram());
576 DD->getProcessedSPNodes().insert(Sub);
578 DIE &ScopeDIE = updateSubprogramScopeDIE(Sub);
580 // If this is a variadic function, add an unspecified parameter.
581 DITypeArray FnArgs = Sub.getType().getTypeArray();
583 // Collect lexical scope children first.
584 // ObjectPointer might be a local (non-argument) local variable if it's a
585 // block's synthetic this pointer.
586 if (DIE *ObjectPointer = createAndAddScopeChildren(Scope, ScopeDIE))
587 addDIEEntry(ScopeDIE, dwarf::DW_AT_object_pointer, *ObjectPointer);
589 // If we have a single element of null, it is a function that returns void.
590 // If we have more than one elements and the last one is null, it is a
591 // variadic function.
592 if (FnArgs.getNumElements() > 1 &&
593 !FnArgs.getElement(FnArgs.getNumElements() - 1) &&
594 !includeMinimalInlineScopes())
595 ScopeDIE.addChild(make_unique<DIE>(dwarf::DW_TAG_unspecified_parameters));
598 DIE *DwarfCompileUnit::createAndAddScopeChildren(LexicalScope *Scope,
600 // We create children when the scope DIE is not null.
601 SmallVector<std::unique_ptr<DIE>, 8> Children;
602 DIE *ObjectPointer = createScopeChildrenDIE(Scope, Children);
605 for (auto &I : Children)
606 ScopeDIE.addChild(std::move(I));
608 return ObjectPointer;
612 DwarfCompileUnit::constructAbstractSubprogramScopeDIE(LexicalScope *Scope) {
613 DIE *&AbsDef = DU->getAbstractSPDies()[Scope->getScopeNode()];
617 DISubprogram SP(Scope->getScopeNode());
621 if (includeMinimalInlineScopes())
622 ContextDIE = &getUnitDie();
623 // Some of this is duplicated from DwarfUnit::getOrCreateSubprogramDIE, with
624 // the important distinction that the DIDescriptor is not associated with the
625 // DIE (since the DIDescriptor will be associated with the concrete DIE, if
626 // any). It could be refactored to some common utility function.
627 else if (DISubprogram SPDecl = SP.getFunctionDeclaration()) {
628 ContextDIE = &getUnitDie();
629 getOrCreateSubprogramDIE(SPDecl);
631 ContextDIE = getOrCreateContextDIE(resolve(SP.getContext()));
633 // Passing null as the associated DIDescriptor because the abstract definition
634 // shouldn't be found by lookup.
636 &createAndAddDIE(dwarf::DW_TAG_subprogram, *ContextDIE, DIDescriptor());
637 applySubprogramAttributesToDefinition(SP, *AbsDef);
639 if (!includeMinimalInlineScopes())
640 addUInt(*AbsDef, dwarf::DW_AT_inline, None, dwarf::DW_INL_inlined);
641 if (DIE *ObjectPointer = createAndAddScopeChildren(Scope, *AbsDef))
642 addDIEEntry(*AbsDef, dwarf::DW_AT_object_pointer, *ObjectPointer);
646 DwarfCompileUnit::constructImportedEntityDIE(const DIImportedEntity &Module) {
647 assert(Module.Verify() &&
648 "Use one of the MDNode * overloads to handle invalid metadata");
649 std::unique_ptr<DIE> IMDie = make_unique<DIE>((dwarf::Tag)Module.getTag());
650 insertDIE(Module, IMDie.get());
652 DIDescriptor Entity = resolve(Module.getEntity());
653 if (Entity.isNameSpace())
654 EntityDie = getOrCreateNameSpace(DINameSpace(Entity));
655 else if (Entity.isSubprogram())
656 EntityDie = getOrCreateSubprogramDIE(DISubprogram(Entity));
657 else if (Entity.isType())
658 EntityDie = getOrCreateTypeDIE(DIType(Entity));
659 else if (Entity.isGlobalVariable())
660 EntityDie = getOrCreateGlobalVariableDIE(DIGlobalVariable(Entity));
662 EntityDie = getDIE(Entity);
664 addSourceLine(*IMDie, Module.getLineNumber(),
665 Module.getContext().getFilename(),
666 Module.getContext().getDirectory());
667 addDIEEntry(*IMDie, dwarf::DW_AT_import, *EntityDie);
668 StringRef Name = Module.getName();
670 addString(*IMDie, dwarf::DW_AT_name, Name);
675 void DwarfCompileUnit::finishSubprogramDefinition(DISubprogram SP) {
677 if (DIE *AbsSPDIE = DU->getAbstractSPDies().lookup(SP)) {
679 // If this subprogram has an abstract definition, reference that
680 addDIEEntry(*D, dwarf::DW_AT_abstract_origin, *AbsSPDIE);
682 if (!D && !includeMinimalInlineScopes())
683 // Lazily construct the subprogram if we didn't see either concrete or
684 // inlined versions during codegen. (except in -gmlt ^ where we want
685 // to omit these entirely)
686 D = getOrCreateSubprogramDIE(SP);
688 // And attach the attributes
689 applySubprogramAttributesToDefinition(SP, *D);
692 void DwarfCompileUnit::collectDeadVariables(DISubprogram SP) {
693 assert(SP.isSubprogram() && "CU's subprogram list contains a non-subprogram");
694 assert(SP.isDefinition() &&
695 "CU's subprogram list contains a subprogram declaration");
696 DIArray Variables = SP.getVariables();
697 if (Variables.getNumElements() == 0)
700 DIE *SPDIE = DU->getAbstractSPDies().lookup(SP);
704 for (unsigned vi = 0, ve = Variables.getNumElements(); vi != ve; ++vi) {
705 DIVariable DV(Variables.getElement(vi));
706 assert(DV.isVariable());
707 DbgVariable NewVar(DV, DIExpression(), DD);
708 auto VariableDie = constructVariableDIE(NewVar);
709 applyVariableAttributes(NewVar, *VariableDie);
710 SPDIE->addChild(std::move(VariableDie));
714 void DwarfCompileUnit::emitHeader(const MCSymbol *ASectionSym) const {
715 // Don't bother labeling the .dwo unit, as its offset isn't used.
717 Asm->OutStreamer.EmitLabel(LabelBegin);
719 DwarfUnit::emitHeader(ASectionSym);
722 /// addGlobalName - Add a new global name to the compile unit.
723 void DwarfCompileUnit::addGlobalName(StringRef Name, DIE &Die,
725 if (includeMinimalInlineScopes())
727 std::string FullName = getParentContextString(Context) + Name.str();
728 GlobalNames[FullName] = &Die;
731 /// Add a new global type to the unit.
732 void DwarfCompileUnit::addGlobalType(DIType Ty, const DIE &Die,
734 if (includeMinimalInlineScopes())
736 std::string FullName = getParentContextString(Context) + Ty.getName().str();
737 GlobalTypes[FullName] = &Die;
740 /// addVariableAddress - Add DW_AT_location attribute for a
741 /// DbgVariable based on provided MachineLocation.
742 void DwarfCompileUnit::addVariableAddress(const DbgVariable &DV, DIE &Die,
743 MachineLocation Location) {
744 if (DV.variableHasComplexAddress())
745 addComplexAddress(DV, Die, dwarf::DW_AT_location, Location);
746 else if (DV.isBlockByrefVariable())
747 addBlockByrefAddress(DV, Die, dwarf::DW_AT_location, Location);
749 addAddress(Die, dwarf::DW_AT_location, Location);
752 /// Add an address attribute to a die based on the location provided.
753 void DwarfCompileUnit::addAddress(DIE &Die, dwarf::Attribute Attribute,
754 const MachineLocation &Location) {
755 DIELoc *Loc = new (DIEValueAllocator) DIELoc();
758 if (Location.isReg())
759 validReg = addRegisterOpPiece(*Loc, Location.getReg());
761 validReg = addRegisterOffset(*Loc, Location.getReg(), Location.getOffset());
766 // Now attach the location information to the DIE.
767 addBlock(Die, Attribute, Loc);
770 /// Start with the address based on the location provided, and generate the
771 /// DWARF information necessary to find the actual variable given the extra
772 /// address information encoded in the DbgVariable, starting from the starting
773 /// location. Add the DWARF information to the die.
774 void DwarfCompileUnit::addComplexAddress(const DbgVariable &DV, DIE &Die,
775 dwarf::Attribute Attribute,
776 const MachineLocation &Location) {
777 DIELoc *Loc = new (DIEValueAllocator) DIELoc();
778 DIEDwarfExpression DwarfExpr(*Asm, *this, *Loc);
779 assert(DV.getExpression().size() == 1);
780 DIExpression Expr = DV.getExpression().back();
782 if (Location.getOffset()) {
783 ValidReg = DwarfExpr.AddMachineRegIndirect(Location.getReg(),
784 Location.getOffset());
786 DwarfExpr.AddExpression(Expr.begin(), Expr.end());
788 ValidReg = DwarfExpr.AddMachineRegExpression(Expr, Location.getReg());
790 // Now attach the location information to the DIE.
792 addBlock(Die, Attribute, Loc);
795 /// Add a Dwarf loclistptr attribute data and value.
796 void DwarfCompileUnit::addLocationList(DIE &Die, dwarf::Attribute Attribute,
798 DIEValue *Value = new (DIEValueAllocator) DIELocList(Index);
799 dwarf::Form Form = DD->getDwarfVersion() >= 4 ? dwarf::DW_FORM_sec_offset
800 : dwarf::DW_FORM_data4;
801 Die.addValue(Attribute, Form, Value);
804 void DwarfCompileUnit::applyVariableAttributes(const DbgVariable &Var,
806 StringRef Name = Var.getName();
808 addString(VariableDie, dwarf::DW_AT_name, Name);
809 addSourceLine(VariableDie, Var.getVariable());
810 addType(VariableDie, Var.getType());
811 if (Var.isArtificial())
812 addFlag(VariableDie, dwarf::DW_AT_artificial);
815 /// Add a Dwarf expression attribute data and value.
816 void DwarfCompileUnit::addExpr(DIELoc &Die, dwarf::Form Form,
817 const MCExpr *Expr) {
818 DIEValue *Value = new (DIEValueAllocator) DIEExpr(Expr);
819 Die.addValue((dwarf::Attribute)0, Form, Value);
822 void DwarfCompileUnit::applySubprogramAttributesToDefinition(DISubprogram SP,
824 DISubprogram SPDecl = SP.getFunctionDeclaration();
825 DIScope Context = resolve(SPDecl ? SPDecl.getContext() : SP.getContext());
826 applySubprogramAttributes(SP, SPDie, includeMinimalInlineScopes());
827 addGlobalName(SP.getName(), SPDie, Context);
830 bool DwarfCompileUnit::isDwoUnit() const {
831 return DD->useSplitDwarf() && Skeleton;
834 bool DwarfCompileUnit::includeMinimalInlineScopes() const {
835 return getCUNode().getEmissionKind() == DIBuilder::LineTablesOnly ||
836 (DD->useSplitDwarf() && !Skeleton);
838 } // end llvm namespace