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), 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 addLinkageName(*VariableDIE, GV.getLinkageName());
178 } else if (const ConstantInt *CI =
179 dyn_cast_or_null<ConstantInt>(GV.getConstant())) {
180 addConstantValue(*VariableDIE, CI, GTy);
181 } else if (const ConstantExpr *CE = getMergedGlobalExpr(GV.getConstant())) {
182 addToAccelTable = true;
183 // GV is a merged global.
184 DIELoc *Loc = new (DIEValueAllocator) DIELoc();
185 Value *Ptr = CE->getOperand(0);
186 MCSymbol *Sym = Asm->getSymbol(cast<GlobalValue>(Ptr));
187 DD->addArangeLabel(SymbolCU(this, Sym));
188 addOpAddress(*Loc, Sym);
189 addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_constu);
190 SmallVector<Value *, 3> Idx(CE->op_begin() + 1, CE->op_end());
191 addUInt(*Loc, dwarf::DW_FORM_udata,
192 Asm->getDataLayout().getIndexedOffset(Ptr->getType(), Idx));
193 addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_plus);
194 addBlock(*VariableDIE, dwarf::DW_AT_location, Loc);
197 if (addToAccelTable) {
198 DD->addAccelName(GV.getName(), *VariableDIE);
200 // If the linkage name is different than the name, go ahead and output
201 // that as well into the name table.
202 if (GV.getLinkageName() != "" && GV.getName() != GV.getLinkageName())
203 DD->addAccelName(GV.getLinkageName(), *VariableDIE);
206 addGlobalName(GV.getName(), *VariableDIE, DeclContext);
210 void DwarfCompileUnit::addRange(RangeSpan Range) {
211 bool SameAsPrevCU = this == DD->getPrevCU();
213 // If we have no current ranges just add the range and return, otherwise,
214 // check the current section and CU against the previous section and CU we
215 // emitted into and the subprogram was contained within. If these are the
216 // same then extend our current range, otherwise add this as a new range.
217 if (CURanges.empty() || !SameAsPrevCU ||
218 (&CURanges.back().getEnd()->getSection() !=
219 &Range.getEnd()->getSection())) {
220 CURanges.push_back(Range);
224 CURanges.back().setEnd(Range.getEnd());
227 void DwarfCompileUnit::addSectionLabel(DIE &Die, dwarf::Attribute Attribute,
228 const MCSymbol *Label,
229 const MCSymbol *Sec) {
230 if (Asm->MAI->doesDwarfUseRelocationsAcrossSections())
231 addLabel(Die, Attribute,
232 DD->getDwarfVersion() >= 4 ? dwarf::DW_FORM_sec_offset
233 : dwarf::DW_FORM_data4,
236 addSectionDelta(Die, Attribute, Label, Sec);
239 void DwarfCompileUnit::initStmtList() {
240 // Define start line table label for each Compile Unit.
241 MCSymbol *LineTableStartSym =
242 Asm->OutStreamer.getDwarfLineTableSymbol(getUniqueID());
244 stmtListIndex = UnitDie.getValues().size();
246 // DW_AT_stmt_list is a offset of line number information for this
247 // compile unit in debug_line section. For split dwarf this is
248 // left in the skeleton CU and so not included.
249 // The line table entries are not always emitted in assembly, so it
250 // is not okay to use line_table_start here.
251 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
252 addSectionLabel(UnitDie, dwarf::DW_AT_stmt_list, LineTableStartSym,
253 TLOF.getDwarfLineSection()->getBeginSymbol());
256 void DwarfCompileUnit::applyStmtList(DIE &D) {
257 D.addValue(dwarf::DW_AT_stmt_list,
258 UnitDie.getAbbrev().getData()[stmtListIndex].getForm(),
259 UnitDie.getValues()[stmtListIndex]);
262 void DwarfCompileUnit::attachLowHighPC(DIE &D, const MCSymbol *Begin,
263 const MCSymbol *End) {
264 assert(Begin && "Begin label should not be null!");
265 assert(End && "End label should not be null!");
266 assert(Begin->isDefined() && "Invalid starting label");
267 assert(End->isDefined() && "Invalid end label");
269 addLabelAddress(D, dwarf::DW_AT_low_pc, Begin);
270 if (DD->getDwarfVersion() < 4)
271 addLabelAddress(D, dwarf::DW_AT_high_pc, End);
273 addLabelDelta(D, dwarf::DW_AT_high_pc, End, Begin);
276 // Find DIE for the given subprogram and attach appropriate DW_AT_low_pc
277 // and DW_AT_high_pc attributes. If there are global variables in this
278 // scope then create and insert DIEs for these variables.
279 DIE &DwarfCompileUnit::updateSubprogramScopeDIE(DISubprogram SP) {
280 DIE *SPDie = getOrCreateSubprogramDIE(SP, includeMinimalInlineScopes());
282 attachLowHighPC(*SPDie, Asm->getFunctionBegin(), Asm->getFunctionEnd());
283 if (!DD->getCurrentFunction()->getTarget().Options.DisableFramePointerElim(
284 *DD->getCurrentFunction()))
285 addFlag(*SPDie, dwarf::DW_AT_APPLE_omit_frame_ptr);
287 // Only include DW_AT_frame_base in full debug info
288 if (!includeMinimalInlineScopes()) {
289 const TargetRegisterInfo *RI = Asm->MF->getSubtarget().getRegisterInfo();
290 MachineLocation Location(RI->getFrameRegister(*Asm->MF));
291 if (RI->isPhysicalRegister(Location.getReg()))
292 addAddress(*SPDie, dwarf::DW_AT_frame_base, Location);
295 // Add name to the name table, we do this here because we're guaranteed
296 // to have concrete versions of our DW_TAG_subprogram nodes.
297 DD->addSubprogramNames(SP, *SPDie);
302 // Construct a DIE for this scope.
303 void DwarfCompileUnit::constructScopeDIE(
304 LexicalScope *Scope, SmallVectorImpl<std::unique_ptr<DIE>> &FinalChildren) {
305 if (!Scope || !Scope->getScopeNode())
308 DIScope DS(Scope->getScopeNode());
310 assert((Scope->getInlinedAt() || !DS.isSubprogram()) &&
311 "Only handle inlined subprograms here, use "
312 "constructSubprogramScopeDIE for non-inlined "
315 SmallVector<std::unique_ptr<DIE>, 8> Children;
317 // We try to create the scope DIE first, then the children DIEs. This will
318 // avoid creating un-used children then removing them later when we find out
319 // the scope DIE is null.
320 std::unique_ptr<DIE> ScopeDIE;
321 if (Scope->getParent() && DS.isSubprogram()) {
322 ScopeDIE = constructInlinedScopeDIE(Scope);
325 // We create children when the scope DIE is not null.
326 createScopeChildrenDIE(Scope, Children);
328 // Early exit when we know the scope DIE is going to be null.
329 if (DD->isLexicalScopeDIENull(Scope))
332 unsigned ChildScopeCount;
334 // We create children here when we know the scope DIE is not going to be
335 // null and the children will be added to the scope DIE.
336 createScopeChildrenDIE(Scope, Children, &ChildScopeCount);
338 // Skip imported directives in gmlt-like data.
339 if (!includeMinimalInlineScopes()) {
340 // There is no need to emit empty lexical block DIE.
341 for (const auto &E : DD->findImportedEntitiesForScope(DS))
343 constructImportedEntityDIE(DIImportedEntity(E.second)));
346 // If there are only other scopes as children, put them directly in the
347 // parent instead, as this scope would serve no purpose.
348 if (Children.size() == ChildScopeCount) {
349 FinalChildren.insert(FinalChildren.end(),
350 std::make_move_iterator(Children.begin()),
351 std::make_move_iterator(Children.end()));
354 ScopeDIE = constructLexicalScopeDIE(Scope);
355 assert(ScopeDIE && "Scope DIE should not be null.");
359 for (auto &I : Children)
360 ScopeDIE->addChild(std::move(I));
362 FinalChildren.push_back(std::move(ScopeDIE));
365 void DwarfCompileUnit::addSectionDelta(DIE &Die, dwarf::Attribute Attribute,
366 const MCSymbol *Hi, const MCSymbol *Lo) {
367 DIEValue *Value = new (DIEValueAllocator) DIEDelta(Hi, Lo);
368 Die.addValue(Attribute, DD->getDwarfVersion() >= 4 ? dwarf::DW_FORM_sec_offset
369 : dwarf::DW_FORM_data4,
373 void DwarfCompileUnit::addScopeRangeList(DIE &ScopeDIE,
374 SmallVector<RangeSpan, 2> Range) {
375 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
377 // Emit offset in .debug_range as a relocatable label. emitDIE will handle
378 // emitting it appropriately.
379 const MCSymbol *RangeSectionSym =
380 TLOF.getDwarfRangesSection()->getBeginSymbol();
383 Asm->GetTempSymbol("debug_ranges", DD->getNextRangeNumber()),
386 // Under fission, ranges are specified by constant offsets relative to the
387 // CU's DW_AT_GNU_ranges_base.
389 addSectionDelta(ScopeDIE, dwarf::DW_AT_ranges, List.getSym(),
392 addSectionLabel(ScopeDIE, dwarf::DW_AT_ranges, List.getSym(),
395 // Add the range list to the set of ranges to be emitted.
396 (Skeleton ? Skeleton : this)->CURangeLists.push_back(std::move(List));
399 void DwarfCompileUnit::attachRangesOrLowHighPC(
400 DIE &Die, SmallVector<RangeSpan, 2> Ranges) {
401 if (Ranges.size() == 1) {
402 const auto &single = Ranges.front();
403 attachLowHighPC(Die, single.getStart(), single.getEnd());
405 addScopeRangeList(Die, std::move(Ranges));
408 void DwarfCompileUnit::attachRangesOrLowHighPC(
409 DIE &Die, const SmallVectorImpl<InsnRange> &Ranges) {
410 SmallVector<RangeSpan, 2> List;
411 List.reserve(Ranges.size());
412 for (const InsnRange &R : Ranges)
413 List.push_back(RangeSpan(DD->getLabelBeforeInsn(R.first),
414 DD->getLabelAfterInsn(R.second)));
415 attachRangesOrLowHighPC(Die, std::move(List));
418 // This scope represents inlined body of a function. Construct DIE to
419 // represent this concrete inlined copy of the function.
421 DwarfCompileUnit::constructInlinedScopeDIE(LexicalScope *Scope) {
422 assert(Scope->getScopeNode());
423 DIScope DS(Scope->getScopeNode());
424 DISubprogram InlinedSP = getDISubprogram(DS);
425 // Find the subprogram's DwarfCompileUnit in the SPMap in case the subprogram
426 // was inlined from another compile unit.
427 DIE *OriginDIE = DU->getAbstractSPDies()[InlinedSP];
428 assert(OriginDIE && "Unable to find original DIE for an inlined subprogram.");
430 auto ScopeDIE = make_unique<DIE>(dwarf::DW_TAG_inlined_subroutine);
431 addDIEEntry(*ScopeDIE, dwarf::DW_AT_abstract_origin, *OriginDIE);
433 attachRangesOrLowHighPC(*ScopeDIE, Scope->getRanges());
435 // Add the call site information to the DIE.
436 DILocation DL(Scope->getInlinedAt());
437 addUInt(*ScopeDIE, dwarf::DW_AT_call_file, None,
438 getOrCreateSourceID(DL.getFilename(), DL.getDirectory()));
439 addUInt(*ScopeDIE, dwarf::DW_AT_call_line, None, DL.getLineNumber());
441 // Add name to the name table, we do this here because we're guaranteed
442 // to have concrete versions of our DW_TAG_inlined_subprogram nodes.
443 DD->addSubprogramNames(InlinedSP, *ScopeDIE);
448 // Construct new DW_TAG_lexical_block for this scope and attach
449 // DW_AT_low_pc/DW_AT_high_pc labels.
451 DwarfCompileUnit::constructLexicalScopeDIE(LexicalScope *Scope) {
452 if (DD->isLexicalScopeDIENull(Scope))
455 auto ScopeDIE = make_unique<DIE>(dwarf::DW_TAG_lexical_block);
456 if (Scope->isAbstractScope())
459 attachRangesOrLowHighPC(*ScopeDIE, Scope->getRanges());
464 /// constructVariableDIE - Construct a DIE for the given DbgVariable.
465 std::unique_ptr<DIE> DwarfCompileUnit::constructVariableDIE(DbgVariable &DV,
467 auto D = constructVariableDIEImpl(DV, Abstract);
473 DwarfCompileUnit::constructVariableDIEImpl(const DbgVariable &DV,
475 // Define variable debug information entry.
476 auto VariableDie = make_unique<DIE>(DV.getTag());
479 applyVariableAttributes(DV, *VariableDie);
483 // Add variable address.
485 unsigned Offset = DV.getDotDebugLocOffset();
487 addLocationList(*VariableDie, dwarf::DW_AT_location, Offset);
491 // Check if variable is described by a DBG_VALUE instruction.
492 if (const MachineInstr *DVInsn = DV.getMInsn()) {
493 assert(DVInsn->getNumOperands() == 4);
494 if (DVInsn->getOperand(0).isReg()) {
495 const MachineOperand RegOp = DVInsn->getOperand(0);
496 // If the second operand is an immediate, this is an indirect value.
497 if (DVInsn->getOperand(1).isImm()) {
498 MachineLocation Location(RegOp.getReg(),
499 DVInsn->getOperand(1).getImm());
500 addVariableAddress(DV, *VariableDie, Location);
501 } else if (RegOp.getReg())
502 addVariableAddress(DV, *VariableDie, MachineLocation(RegOp.getReg()));
503 } else if (DVInsn->getOperand(0).isImm())
504 addConstantValue(*VariableDie, DVInsn->getOperand(0), DV.getType());
505 else if (DVInsn->getOperand(0).isFPImm())
506 addConstantFPValue(*VariableDie, DVInsn->getOperand(0));
507 else if (DVInsn->getOperand(0).isCImm())
508 addConstantValue(*VariableDie, DVInsn->getOperand(0).getCImm(),
514 // .. else use frame index.
515 if (DV.getFrameIndex().back() == ~0)
518 auto Expr = DV.getExpression().begin();
519 DIELoc *Loc = new (DIEValueAllocator) DIELoc();
520 DIEDwarfExpression DwarfExpr(*Asm, *this, *Loc);
521 for (auto FI : DV.getFrameIndex()) {
522 unsigned FrameReg = 0;
523 const TargetFrameLowering *TFI = Asm->MF->getSubtarget().getFrameLowering();
524 int Offset = TFI->getFrameIndexReference(*Asm->MF, FI, FrameReg);
525 assert(Expr != DV.getExpression().end() &&
526 "Wrong number of expressions");
527 DwarfExpr.AddMachineRegIndirect(FrameReg, Offset);
528 DwarfExpr.AddExpression(Expr->begin(), Expr->end());
531 addBlock(*VariableDie, dwarf::DW_AT_location, Loc);
536 std::unique_ptr<DIE> DwarfCompileUnit::constructVariableDIE(
537 DbgVariable &DV, const LexicalScope &Scope, DIE *&ObjectPointer) {
538 auto Var = constructVariableDIE(DV, Scope.isAbstractScope());
539 if (DV.isObjectPointer())
540 ObjectPointer = Var.get();
544 DIE *DwarfCompileUnit::createScopeChildrenDIE(
545 LexicalScope *Scope, SmallVectorImpl<std::unique_ptr<DIE>> &Children,
546 unsigned *ChildScopeCount) {
547 DIE *ObjectPointer = nullptr;
549 for (DbgVariable *DV : DU->getScopeVariables().lookup(Scope))
550 Children.push_back(constructVariableDIE(*DV, *Scope, ObjectPointer));
552 unsigned ChildCountWithoutScopes = Children.size();
554 for (LexicalScope *LS : Scope->getChildren())
555 constructScopeDIE(LS, Children);
558 *ChildScopeCount = Children.size() - ChildCountWithoutScopes;
560 return ObjectPointer;
563 void DwarfCompileUnit::constructSubprogramScopeDIE(LexicalScope *Scope) {
564 assert(Scope && Scope->getScopeNode());
565 assert(!Scope->getInlinedAt());
566 assert(!Scope->isAbstractScope());
567 DISubprogram Sub(Scope->getScopeNode());
569 assert(Sub.isSubprogram());
571 DD->getProcessedSPNodes().insert(Sub);
573 DIE &ScopeDIE = updateSubprogramScopeDIE(Sub);
575 // If this is a variadic function, add an unspecified parameter.
576 DITypeArray FnArgs = Sub.getType().getTypeArray();
578 // Collect lexical scope children first.
579 // ObjectPointer might be a local (non-argument) local variable if it's a
580 // block's synthetic this pointer.
581 if (DIE *ObjectPointer = createAndAddScopeChildren(Scope, ScopeDIE))
582 addDIEEntry(ScopeDIE, dwarf::DW_AT_object_pointer, *ObjectPointer);
584 // If we have a single element of null, it is a function that returns void.
585 // If we have more than one elements and the last one is null, it is a
586 // variadic function.
587 if (FnArgs.getNumElements() > 1 &&
588 !FnArgs.getElement(FnArgs.getNumElements() - 1) &&
589 !includeMinimalInlineScopes())
590 ScopeDIE.addChild(make_unique<DIE>(dwarf::DW_TAG_unspecified_parameters));
593 DIE *DwarfCompileUnit::createAndAddScopeChildren(LexicalScope *Scope,
595 // We create children when the scope DIE is not null.
596 SmallVector<std::unique_ptr<DIE>, 8> Children;
597 DIE *ObjectPointer = createScopeChildrenDIE(Scope, Children);
600 for (auto &I : Children)
601 ScopeDIE.addChild(std::move(I));
603 return ObjectPointer;
607 DwarfCompileUnit::constructAbstractSubprogramScopeDIE(LexicalScope *Scope) {
608 DIE *&AbsDef = DU->getAbstractSPDies()[Scope->getScopeNode()];
612 DISubprogram SP(Scope->getScopeNode());
616 if (includeMinimalInlineScopes())
617 ContextDIE = &getUnitDie();
618 // Some of this is duplicated from DwarfUnit::getOrCreateSubprogramDIE, with
619 // the important distinction that the DIDescriptor is not associated with the
620 // DIE (since the DIDescriptor will be associated with the concrete DIE, if
621 // any). It could be refactored to some common utility function.
622 else if (DISubprogram SPDecl = SP.getFunctionDeclaration()) {
623 ContextDIE = &getUnitDie();
624 getOrCreateSubprogramDIE(SPDecl);
626 ContextDIE = getOrCreateContextDIE(resolve(SP.getContext()));
628 // Passing null as the associated DIDescriptor because the abstract definition
629 // shouldn't be found by lookup.
631 &createAndAddDIE(dwarf::DW_TAG_subprogram, *ContextDIE, DIDescriptor());
632 applySubprogramAttributesToDefinition(SP, *AbsDef);
634 if (!includeMinimalInlineScopes())
635 addUInt(*AbsDef, dwarf::DW_AT_inline, None, dwarf::DW_INL_inlined);
636 if (DIE *ObjectPointer = createAndAddScopeChildren(Scope, *AbsDef))
637 addDIEEntry(*AbsDef, dwarf::DW_AT_object_pointer, *ObjectPointer);
641 DwarfCompileUnit::constructImportedEntityDIE(const DIImportedEntity &Module) {
642 assert(Module.Verify() &&
643 "Use one of the MDNode * overloads to handle invalid metadata");
644 std::unique_ptr<DIE> IMDie = make_unique<DIE>((dwarf::Tag)Module.getTag());
645 insertDIE(Module, IMDie.get());
647 DIDescriptor Entity = resolve(Module.getEntity());
648 if (Entity.isNameSpace())
649 EntityDie = getOrCreateNameSpace(DINameSpace(Entity));
650 else if (Entity.isSubprogram())
651 EntityDie = getOrCreateSubprogramDIE(DISubprogram(Entity));
652 else if (Entity.isType())
653 EntityDie = getOrCreateTypeDIE(DIType(Entity));
654 else if (Entity.isGlobalVariable())
655 EntityDie = getOrCreateGlobalVariableDIE(DIGlobalVariable(Entity));
657 EntityDie = getDIE(Entity);
659 addSourceLine(*IMDie, Module.getLineNumber(),
660 Module.getContext().getFilename(),
661 Module.getContext().getDirectory());
662 addDIEEntry(*IMDie, dwarf::DW_AT_import, *EntityDie);
663 StringRef Name = Module.getName();
665 addString(*IMDie, dwarf::DW_AT_name, Name);
670 void DwarfCompileUnit::finishSubprogramDefinition(DISubprogram SP) {
672 if (DIE *AbsSPDIE = DU->getAbstractSPDies().lookup(SP)) {
674 // If this subprogram has an abstract definition, reference that
675 addDIEEntry(*D, dwarf::DW_AT_abstract_origin, *AbsSPDIE);
677 if (!D && !includeMinimalInlineScopes())
678 // Lazily construct the subprogram if we didn't see either concrete or
679 // inlined versions during codegen. (except in -gmlt ^ where we want
680 // to omit these entirely)
681 D = getOrCreateSubprogramDIE(SP);
683 // And attach the attributes
684 applySubprogramAttributesToDefinition(SP, *D);
687 void DwarfCompileUnit::collectDeadVariables(DISubprogram SP) {
688 assert(SP.isSubprogram() && "CU's subprogram list contains a non-subprogram");
689 assert(SP.isDefinition() &&
690 "CU's subprogram list contains a subprogram declaration");
691 DIArray Variables = SP.getVariables();
692 if (Variables.getNumElements() == 0)
695 DIE *SPDIE = DU->getAbstractSPDies().lookup(SP);
699 for (unsigned vi = 0, ve = Variables.getNumElements(); vi != ve; ++vi) {
700 DIVariable DV(Variables.getElement(vi));
701 assert(DV.isVariable());
702 DbgVariable NewVar(DV, DIExpression(), DD);
703 auto VariableDie = constructVariableDIE(NewVar);
704 applyVariableAttributes(NewVar, *VariableDie);
705 SPDIE->addChild(std::move(VariableDie));
709 void DwarfCompileUnit::emitHeader(bool UseOffsets) {
710 // Don't bother labeling the .dwo unit, as its offset isn't used.
712 LabelBegin = Asm->createTempSymbol("cu_begin", getUniqueID());
713 Asm->OutStreamer.EmitLabel(LabelBegin);
716 DwarfUnit::emitHeader(UseOffsets);
719 /// addGlobalName - Add a new global name to the compile unit.
720 void DwarfCompileUnit::addGlobalName(StringRef Name, DIE &Die,
722 if (includeMinimalInlineScopes())
724 std::string FullName = getParentContextString(Context) + Name.str();
725 GlobalNames[FullName] = &Die;
728 /// Add a new global type to the unit.
729 void DwarfCompileUnit::addGlobalType(DIType Ty, const DIE &Die,
731 if (includeMinimalInlineScopes())
733 std::string FullName = getParentContextString(Context) + Ty.getName().str();
734 GlobalTypes[FullName] = &Die;
737 /// addVariableAddress - Add DW_AT_location attribute for a
738 /// DbgVariable based on provided MachineLocation.
739 void DwarfCompileUnit::addVariableAddress(const DbgVariable &DV, DIE &Die,
740 MachineLocation Location) {
741 if (DV.variableHasComplexAddress())
742 addComplexAddress(DV, Die, dwarf::DW_AT_location, Location);
743 else if (DV.isBlockByrefVariable())
744 addBlockByrefAddress(DV, Die, dwarf::DW_AT_location, Location);
746 addAddress(Die, dwarf::DW_AT_location, Location);
749 /// Add an address attribute to a die based on the location provided.
750 void DwarfCompileUnit::addAddress(DIE &Die, dwarf::Attribute Attribute,
751 const MachineLocation &Location) {
752 DIELoc *Loc = new (DIEValueAllocator) DIELoc();
755 if (Location.isReg())
756 validReg = addRegisterOpPiece(*Loc, Location.getReg());
758 validReg = addRegisterOffset(*Loc, Location.getReg(), Location.getOffset());
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 assert(DV.getExpression().size() == 1);
777 DIExpression Expr = DV.getExpression().back();
779 if (Location.getOffset()) {
780 ValidReg = DwarfExpr.AddMachineRegIndirect(Location.getReg(),
781 Location.getOffset());
783 DwarfExpr.AddExpression(Expr.begin(), Expr.end());
785 ValidReg = DwarfExpr.AddMachineRegExpression(Expr, Location.getReg());
787 // Now attach the location information to the DIE.
789 addBlock(Die, Attribute, Loc);
792 /// Add a Dwarf loclistptr attribute data and value.
793 void DwarfCompileUnit::addLocationList(DIE &Die, dwarf::Attribute Attribute,
795 DIEValue *Value = new (DIEValueAllocator) DIELocList(Index);
796 dwarf::Form Form = DD->getDwarfVersion() >= 4 ? dwarf::DW_FORM_sec_offset
797 : dwarf::DW_FORM_data4;
798 Die.addValue(Attribute, Form, Value);
801 void DwarfCompileUnit::applyVariableAttributes(const DbgVariable &Var,
803 StringRef Name = Var.getName();
805 addString(VariableDie, dwarf::DW_AT_name, Name);
806 addSourceLine(VariableDie, Var.getVariable());
807 addType(VariableDie, Var.getType());
808 if (Var.isArtificial())
809 addFlag(VariableDie, dwarf::DW_AT_artificial);
812 /// Add a Dwarf expression attribute data and value.
813 void DwarfCompileUnit::addExpr(DIELoc &Die, dwarf::Form Form,
814 const MCExpr *Expr) {
815 DIEValue *Value = new (DIEValueAllocator) DIEExpr(Expr);
816 Die.addValue((dwarf::Attribute)0, Form, Value);
819 void DwarfCompileUnit::applySubprogramAttributesToDefinition(DISubprogram SP,
821 DISubprogram SPDecl = SP.getFunctionDeclaration();
822 DIScope Context = resolve(SPDecl ? SPDecl.getContext() : SP.getContext());
823 applySubprogramAttributes(SP, SPDie, includeMinimalInlineScopes());
824 addGlobalName(SP.getName(), SPDie, Context);
827 bool DwarfCompileUnit::isDwoUnit() const {
828 return DD->useSplitDwarf() && Skeleton;
831 bool DwarfCompileUnit::includeMinimalInlineScopes() const {
832 return getCUNode().getEmissionKind() == DIBuilder::LineTablesOnly ||
833 (DD->useSplitDwarf() && !Skeleton);
835 } // end llvm namespace