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))
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 if (auto *Global = dyn_cast_or_null<GlobalVariable>(GV.getConstant())) {
144 addToAccelTable = true;
145 DIELoc *Loc = new (DIEValueAllocator) DIELoc();
146 const MCSymbol *Sym = Asm->getSymbol(Global);
147 if (Global->isThreadLocal()) {
148 // FIXME: Make this work with -gsplit-dwarf.
149 unsigned PointerSize = Asm->getDataLayout().getPointerSize();
150 assert((PointerSize == 4 || PointerSize == 8) &&
151 "Add support for other sizes if necessary");
152 // Based on GCC's support for TLS:
153 if (!DD->useSplitDwarf()) {
154 // 1) Start with a constNu of the appropriate pointer size
155 addUInt(*Loc, dwarf::DW_FORM_data1,
156 PointerSize == 4 ? dwarf::DW_OP_const4u : dwarf::DW_OP_const8u);
157 // 2) containing the (relocated) offset of the TLS variable
158 // within the module's TLS block.
159 addExpr(*Loc, dwarf::DW_FORM_udata,
160 Asm->getObjFileLowering().getDebugThreadLocalSymbol(Sym));
162 addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_GNU_const_index);
163 addUInt(*Loc, dwarf::DW_FORM_udata,
164 DD->getAddressPool().getIndex(Sym, /* TLS */ true));
166 // 3) followed by an OP to make the debugger do a TLS lookup.
167 addUInt(*Loc, dwarf::DW_FORM_data1,
168 DD->useGNUTLSOpcode() ? dwarf::DW_OP_GNU_push_tls_address
169 : dwarf::DW_OP_form_tls_address);
171 DD->addArangeLabel(SymbolCU(this, Sym));
172 addOpAddress(*Loc, Sym);
175 addBlock(*VariableDIE, dwarf::DW_AT_location, Loc);
176 addLinkageName(*VariableDIE, GV.getLinkageName());
177 } else if (const ConstantInt *CI =
178 dyn_cast_or_null<ConstantInt>(GV.getConstant())) {
179 addConstantValue(*VariableDIE, CI, GTy);
180 } else if (const ConstantExpr *CE = getMergedGlobalExpr(GV.getConstant())) {
181 addToAccelTable = true;
182 // GV is a merged global.
183 DIELoc *Loc = new (DIEValueAllocator) DIELoc();
184 Value *Ptr = CE->getOperand(0);
185 MCSymbol *Sym = Asm->getSymbol(cast<GlobalValue>(Ptr));
186 DD->addArangeLabel(SymbolCU(this, Sym));
187 addOpAddress(*Loc, Sym);
188 addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_constu);
189 SmallVector<Value *, 3> Idx(CE->op_begin() + 1, CE->op_end());
190 addUInt(*Loc, dwarf::DW_FORM_udata,
191 Asm->getDataLayout().getIndexedOffset(Ptr->getType(), Idx));
192 addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_plus);
193 addBlock(*VariableDIE, dwarf::DW_AT_location, Loc);
196 if (addToAccelTable) {
197 DD->addAccelName(GV.getName(), *VariableDIE);
199 // If the linkage name is different than the name, go ahead and output
200 // that as well into the name table.
201 if (GV.getLinkageName() != "" && GV.getName() != GV.getLinkageName())
202 DD->addAccelName(GV.getLinkageName(), *VariableDIE);
205 addGlobalName(GV.getName(), *VariableDIE, DeclContext);
209 void DwarfCompileUnit::addRange(RangeSpan Range) {
210 bool SameAsPrevCU = this == DD->getPrevCU();
212 // If we have no current ranges just add the range and return, otherwise,
213 // check the current section and CU against the previous section and CU we
214 // emitted into and the subprogram was contained within. If these are the
215 // same then extend our current range, otherwise add this as a new range.
216 if (CURanges.empty() || !SameAsPrevCU ||
217 (&CURanges.back().getEnd()->getSection() !=
218 &Range.getEnd()->getSection())) {
219 CURanges.push_back(Range);
223 CURanges.back().setEnd(Range.getEnd());
226 void DwarfCompileUnit::addSectionLabel(DIE &Die, dwarf::Attribute Attribute,
227 const MCSymbol *Label,
228 const MCSymbol *Sec) {
229 if (Asm->MAI->doesDwarfUseRelocationsAcrossSections())
230 addLabel(Die, Attribute,
231 DD->getDwarfVersion() >= 4 ? dwarf::DW_FORM_sec_offset
232 : dwarf::DW_FORM_data4,
235 addSectionDelta(Die, Attribute, Label, Sec);
238 void DwarfCompileUnit::initStmtList() {
239 // Define start line table label for each Compile Unit.
240 MCSymbol *LineTableStartSym =
241 Asm->OutStreamer.getDwarfLineTableSymbol(getUniqueID());
243 stmtListIndex = UnitDie.getValues().size();
245 // DW_AT_stmt_list is a offset of line number information for this
246 // compile unit in debug_line section. For split dwarf this is
247 // left in the skeleton CU and so not included.
248 // The line table entries are not always emitted in assembly, so it
249 // is not okay to use line_table_start here.
250 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
251 addSectionLabel(UnitDie, dwarf::DW_AT_stmt_list, LineTableStartSym,
252 TLOF.getDwarfLineSection()->getBeginSymbol());
255 void DwarfCompileUnit::applyStmtList(DIE &D) {
256 D.addValue(dwarf::DW_AT_stmt_list,
257 UnitDie.getAbbrev().getData()[stmtListIndex].getForm(),
258 UnitDie.getValues()[stmtListIndex]);
261 void DwarfCompileUnit::attachLowHighPC(DIE &D, const MCSymbol *Begin,
262 const MCSymbol *End) {
263 assert(Begin && "Begin label should not be null!");
264 assert(End && "End label should not be null!");
265 assert(Begin->isDefined() && "Invalid starting label");
266 assert(End->isDefined() && "Invalid end label");
268 addLabelAddress(D, dwarf::DW_AT_low_pc, Begin);
269 if (DD->getDwarfVersion() < 4)
270 addLabelAddress(D, dwarf::DW_AT_high_pc, End);
272 addLabelDelta(D, dwarf::DW_AT_high_pc, End, Begin);
275 // Find DIE for the given subprogram and attach appropriate DW_AT_low_pc
276 // and DW_AT_high_pc attributes. If there are global variables in this
277 // scope then create and insert DIEs for these variables.
278 DIE &DwarfCompileUnit::updateSubprogramScopeDIE(DISubprogram SP) {
279 DIE *SPDie = getOrCreateSubprogramDIE(SP, includeMinimalInlineScopes());
281 attachLowHighPC(*SPDie, Asm->getFunctionBegin(), Asm->getFunctionEnd());
282 if (!DD->getCurrentFunction()->getTarget().Options.DisableFramePointerElim(
283 *DD->getCurrentFunction()))
284 addFlag(*SPDie, dwarf::DW_AT_APPLE_omit_frame_ptr);
286 // Only include DW_AT_frame_base in full debug info
287 if (!includeMinimalInlineScopes()) {
288 const TargetRegisterInfo *RI = Asm->MF->getSubtarget().getRegisterInfo();
289 MachineLocation Location(RI->getFrameRegister(*Asm->MF));
290 if (RI->isPhysicalRegister(Location.getReg()))
291 addAddress(*SPDie, dwarf::DW_AT_frame_base, Location);
294 // Add name to the name table, we do this here because we're guaranteed
295 // to have concrete versions of our DW_TAG_subprogram nodes.
296 DD->addSubprogramNames(SP, *SPDie);
301 // Construct a DIE for this scope.
302 void DwarfCompileUnit::constructScopeDIE(
303 LexicalScope *Scope, SmallVectorImpl<std::unique_ptr<DIE>> &FinalChildren) {
304 if (!Scope || !Scope->getScopeNode())
307 DIScope DS(Scope->getScopeNode());
309 assert((Scope->getInlinedAt() || !isa<MDSubprogram>(DS)) &&
310 "Only handle inlined subprograms here, use "
311 "constructSubprogramScopeDIE for non-inlined "
314 SmallVector<std::unique_ptr<DIE>, 8> Children;
316 // We try to create the scope DIE first, then the children DIEs. This will
317 // avoid creating un-used children then removing them later when we find out
318 // the scope DIE is null.
319 std::unique_ptr<DIE> ScopeDIE;
320 if (Scope->getParent() && isa<MDSubprogram>(DS)) {
321 ScopeDIE = constructInlinedScopeDIE(Scope);
324 // We create children when the scope DIE is not null.
325 createScopeChildrenDIE(Scope, Children);
327 // Early exit when we know the scope DIE is going to be null.
328 if (DD->isLexicalScopeDIENull(Scope))
331 unsigned ChildScopeCount;
333 // We create children here when we know the scope DIE is not going to be
334 // null and the children will be added to the scope DIE.
335 createScopeChildrenDIE(Scope, Children, &ChildScopeCount);
337 // Skip imported directives in gmlt-like data.
338 if (!includeMinimalInlineScopes()) {
339 // There is no need to emit empty lexical block DIE.
340 for (const auto &E : DD->findImportedEntitiesForScope(DS))
342 constructImportedEntityDIE(cast<MDImportedEntity>(E.second)));
345 // If there are only other scopes as children, put them directly in the
346 // parent instead, as this scope would serve no purpose.
347 if (Children.size() == ChildScopeCount) {
348 FinalChildren.insert(FinalChildren.end(),
349 std::make_move_iterator(Children.begin()),
350 std::make_move_iterator(Children.end()));
353 ScopeDIE = constructLexicalScopeDIE(Scope);
354 assert(ScopeDIE && "Scope DIE should not be null.");
358 for (auto &I : Children)
359 ScopeDIE->addChild(std::move(I));
361 FinalChildren.push_back(std::move(ScopeDIE));
364 void DwarfCompileUnit::addSectionDelta(DIE &Die, dwarf::Attribute Attribute,
365 const MCSymbol *Hi, const MCSymbol *Lo) {
366 DIEValue *Value = new (DIEValueAllocator) DIEDelta(Hi, Lo);
367 Die.addValue(Attribute, DD->getDwarfVersion() >= 4 ? dwarf::DW_FORM_sec_offset
368 : dwarf::DW_FORM_data4,
372 void DwarfCompileUnit::addScopeRangeList(DIE &ScopeDIE,
373 SmallVector<RangeSpan, 2> Range) {
374 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
376 // Emit offset in .debug_range as a relocatable label. emitDIE will handle
377 // emitting it appropriately.
378 const MCSymbol *RangeSectionSym =
379 TLOF.getDwarfRangesSection()->getBeginSymbol();
381 RangeSpanList List(Asm->createTempSymbol("debug_ranges"), std::move(Range));
383 // Under fission, ranges are specified by constant offsets relative to the
384 // CU's DW_AT_GNU_ranges_base.
386 addSectionDelta(ScopeDIE, dwarf::DW_AT_ranges, List.getSym(),
389 addSectionLabel(ScopeDIE, dwarf::DW_AT_ranges, List.getSym(),
392 // Add the range list to the set of ranges to be emitted.
393 (Skeleton ? Skeleton : this)->CURangeLists.push_back(std::move(List));
396 void DwarfCompileUnit::attachRangesOrLowHighPC(
397 DIE &Die, SmallVector<RangeSpan, 2> Ranges) {
398 if (Ranges.size() == 1) {
399 const auto &single = Ranges.front();
400 attachLowHighPC(Die, single.getStart(), single.getEnd());
402 addScopeRangeList(Die, std::move(Ranges));
405 void DwarfCompileUnit::attachRangesOrLowHighPC(
406 DIE &Die, const SmallVectorImpl<InsnRange> &Ranges) {
407 SmallVector<RangeSpan, 2> List;
408 List.reserve(Ranges.size());
409 for (const InsnRange &R : Ranges)
410 List.push_back(RangeSpan(DD->getLabelBeforeInsn(R.first),
411 DD->getLabelAfterInsn(R.second)));
412 attachRangesOrLowHighPC(Die, std::move(List));
415 // This scope represents inlined body of a function. Construct DIE to
416 // represent this concrete inlined copy of the function.
418 DwarfCompileUnit::constructInlinedScopeDIE(LexicalScope *Scope) {
419 assert(Scope->getScopeNode());
420 DIScope DS(Scope->getScopeNode());
421 DISubprogram InlinedSP = getDISubprogram(DS);
422 // Find the subprogram's DwarfCompileUnit in the SPMap in case the subprogram
423 // was inlined from another compile unit.
424 DIE *OriginDIE = DU->getAbstractSPDies()[InlinedSP];
425 assert(OriginDIE && "Unable to find original DIE for an inlined subprogram.");
427 auto ScopeDIE = make_unique<DIE>(dwarf::DW_TAG_inlined_subroutine);
428 addDIEEntry(*ScopeDIE, dwarf::DW_AT_abstract_origin, *OriginDIE);
430 attachRangesOrLowHighPC(*ScopeDIE, Scope->getRanges());
432 // Add the call site information to the DIE.
433 const MDLocation *IA = Scope->getInlinedAt();
434 addUInt(*ScopeDIE, dwarf::DW_AT_call_file, None,
435 getOrCreateSourceID(IA->getFilename(), IA->getDirectory()));
436 addUInt(*ScopeDIE, dwarf::DW_AT_call_line, None, IA->getLine());
438 // Add name to the name table, we do this here because we're guaranteed
439 // to have concrete versions of our DW_TAG_inlined_subprogram nodes.
440 DD->addSubprogramNames(InlinedSP, *ScopeDIE);
445 // Construct new DW_TAG_lexical_block for this scope and attach
446 // DW_AT_low_pc/DW_AT_high_pc labels.
448 DwarfCompileUnit::constructLexicalScopeDIE(LexicalScope *Scope) {
449 if (DD->isLexicalScopeDIENull(Scope))
452 auto ScopeDIE = make_unique<DIE>(dwarf::DW_TAG_lexical_block);
453 if (Scope->isAbstractScope())
456 attachRangesOrLowHighPC(*ScopeDIE, Scope->getRanges());
461 /// constructVariableDIE - Construct a DIE for the given DbgVariable.
462 std::unique_ptr<DIE> DwarfCompileUnit::constructVariableDIE(DbgVariable &DV,
464 auto D = constructVariableDIEImpl(DV, Abstract);
470 DwarfCompileUnit::constructVariableDIEImpl(const DbgVariable &DV,
472 // Define variable debug information entry.
473 auto VariableDie = make_unique<DIE>(DV.getTag());
476 applyVariableAttributes(DV, *VariableDie);
480 // Add variable address.
482 unsigned Offset = DV.getDotDebugLocOffset();
484 addLocationList(*VariableDie, dwarf::DW_AT_location, Offset);
488 // Check if variable is described by a DBG_VALUE instruction.
489 if (const MachineInstr *DVInsn = DV.getMInsn()) {
490 assert(DVInsn->getNumOperands() == 4);
491 if (DVInsn->getOperand(0).isReg()) {
492 const MachineOperand RegOp = DVInsn->getOperand(0);
493 // If the second operand is an immediate, this is an indirect value.
494 if (DVInsn->getOperand(1).isImm()) {
495 MachineLocation Location(RegOp.getReg(),
496 DVInsn->getOperand(1).getImm());
497 addVariableAddress(DV, *VariableDie, Location);
498 } else if (RegOp.getReg())
499 addVariableAddress(DV, *VariableDie, MachineLocation(RegOp.getReg()));
500 } else if (DVInsn->getOperand(0).isImm())
501 addConstantValue(*VariableDie, DVInsn->getOperand(0), DV.getType());
502 else if (DVInsn->getOperand(0).isFPImm())
503 addConstantFPValue(*VariableDie, DVInsn->getOperand(0));
504 else if (DVInsn->getOperand(0).isCImm())
505 addConstantValue(*VariableDie, DVInsn->getOperand(0).getCImm(),
511 // .. else use frame index.
512 if (DV.getFrameIndex().back() == ~0)
515 auto Expr = DV.getExpression().begin();
516 DIELoc *Loc = new (DIEValueAllocator) DIELoc();
517 DIEDwarfExpression DwarfExpr(*Asm, *this, *Loc);
518 for (auto FI : DV.getFrameIndex()) {
519 unsigned FrameReg = 0;
520 const TargetFrameLowering *TFI = Asm->MF->getSubtarget().getFrameLowering();
521 int Offset = TFI->getFrameIndexReference(*Asm->MF, FI, FrameReg);
522 assert(Expr != DV.getExpression().end() &&
523 "Wrong number of expressions");
524 DwarfExpr.AddMachineRegIndirect(FrameReg, Offset);
525 DwarfExpr.AddExpression((*Expr)->expr_op_begin(), (*Expr)->expr_op_end());
528 addBlock(*VariableDie, dwarf::DW_AT_location, Loc);
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 = cast<MDSubprogram>(Scope->getScopeNode());
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.size() > 1 && !FnArgs[FnArgs.size() - 1] &&
583 !includeMinimalInlineScopes())
584 ScopeDIE.addChild(make_unique<DIE>(dwarf::DW_TAG_unspecified_parameters));
587 DIE *DwarfCompileUnit::createAndAddScopeChildren(LexicalScope *Scope,
589 // We create children when the scope DIE is not null.
590 SmallVector<std::unique_ptr<DIE>, 8> Children;
591 DIE *ObjectPointer = createScopeChildrenDIE(Scope, Children);
594 for (auto &I : Children)
595 ScopeDIE.addChild(std::move(I));
597 return ObjectPointer;
601 DwarfCompileUnit::constructAbstractSubprogramScopeDIE(LexicalScope *Scope) {
602 DIE *&AbsDef = DU->getAbstractSPDies()[Scope->getScopeNode()];
606 DISubprogram SP = cast<MDSubprogram>(Scope->getScopeNode());
610 if (includeMinimalInlineScopes())
611 ContextDIE = &getUnitDie();
612 // Some of this is duplicated from DwarfUnit::getOrCreateSubprogramDIE, with
613 // the important distinction that the DIDescriptor is not associated with the
614 // DIE (since the DIDescriptor will be associated with the concrete DIE, if
615 // any). It could be refactored to some common utility function.
616 else if (DISubprogram SPDecl = SP.getFunctionDeclaration()) {
617 ContextDIE = &getUnitDie();
618 getOrCreateSubprogramDIE(SPDecl);
620 ContextDIE = getOrCreateContextDIE(resolve(SP.getContext()));
622 // Passing null as the associated DIDescriptor because the abstract definition
623 // shouldn't be found by lookup.
625 &createAndAddDIE(dwarf::DW_TAG_subprogram, *ContextDIE, DIDescriptor());
626 applySubprogramAttributesToDefinition(SP, *AbsDef);
628 if (!includeMinimalInlineScopes())
629 addUInt(*AbsDef, dwarf::DW_AT_inline, None, dwarf::DW_INL_inlined);
630 if (DIE *ObjectPointer = createAndAddScopeChildren(Scope, *AbsDef))
631 addDIEEntry(*AbsDef, dwarf::DW_AT_object_pointer, *ObjectPointer);
635 DwarfCompileUnit::constructImportedEntityDIE(const DIImportedEntity &Module) {
636 std::unique_ptr<DIE> IMDie = make_unique<DIE>((dwarf::Tag)Module->getTag());
637 insertDIE(Module, IMDie.get());
639 auto *Entity = resolve(Module->getEntity());
640 if (auto *NS = dyn_cast<MDNamespace>(Entity))
641 EntityDie = getOrCreateNameSpace(NS);
642 else if (auto *SP = dyn_cast<MDSubprogram>(Entity))
643 EntityDie = getOrCreateSubprogramDIE(SP);
644 else if (auto *T = dyn_cast<MDType>(Entity))
645 EntityDie = getOrCreateTypeDIE(T);
646 else if (auto *GV = dyn_cast<MDGlobalVariable>(Entity))
647 EntityDie = getOrCreateGlobalVariableDIE(GV);
649 EntityDie = getDIE(Entity);
651 addSourceLine(*IMDie, Module->getLine(), Module->getScope()->getFilename(),
652 Module->getScope()->getDirectory());
653 addDIEEntry(*IMDie, dwarf::DW_AT_import, *EntityDie);
654 StringRef Name = Module->getName();
656 addString(*IMDie, dwarf::DW_AT_name, Name);
661 void DwarfCompileUnit::finishSubprogramDefinition(DISubprogram SP) {
663 if (DIE *AbsSPDIE = DU->getAbstractSPDies().lookup(SP)) {
665 // If this subprogram has an abstract definition, reference that
666 addDIEEntry(*D, dwarf::DW_AT_abstract_origin, *AbsSPDIE);
668 if (!D && !includeMinimalInlineScopes())
669 // Lazily construct the subprogram if we didn't see either concrete or
670 // inlined versions during codegen. (except in -gmlt ^ where we want
671 // to omit these entirely)
672 D = getOrCreateSubprogramDIE(SP);
674 // And attach the attributes
675 applySubprogramAttributesToDefinition(SP, *D);
678 void DwarfCompileUnit::collectDeadVariables(DISubprogram SP) {
679 assert(SP && "CU's subprogram list contains a non-subprogram");
680 assert(SP.isDefinition() &&
681 "CU's subprogram list contains a subprogram declaration");
682 auto Variables = SP->getVariables();
683 if (Variables.size() == 0)
686 DIE *SPDIE = DU->getAbstractSPDies().lookup(SP);
690 for (DIVariable DV : Variables) {
691 DbgVariable NewVar(DV, DIExpression(), DD);
692 auto VariableDie = constructVariableDIE(NewVar);
693 applyVariableAttributes(NewVar, *VariableDie);
694 SPDIE->addChild(std::move(VariableDie));
698 void DwarfCompileUnit::emitHeader(bool UseOffsets) {
699 // Don't bother labeling the .dwo unit, as its offset isn't used.
701 LabelBegin = Asm->createTempSymbol("cu_begin");
702 Asm->OutStreamer.EmitLabel(LabelBegin);
705 DwarfUnit::emitHeader(UseOffsets);
708 /// addGlobalName - Add a new global name to the compile unit.
709 void DwarfCompileUnit::addGlobalName(StringRef Name, DIE &Die,
711 if (includeMinimalInlineScopes())
713 std::string FullName = getParentContextString(Context) + Name.str();
714 GlobalNames[FullName] = &Die;
717 /// Add a new global type to the unit.
718 void DwarfCompileUnit::addGlobalType(DIType Ty, const DIE &Die,
720 if (includeMinimalInlineScopes())
722 std::string FullName = getParentContextString(Context) + Ty.getName().str();
723 GlobalTypes[FullName] = &Die;
726 /// addVariableAddress - Add DW_AT_location attribute for a
727 /// DbgVariable based on provided MachineLocation.
728 void DwarfCompileUnit::addVariableAddress(const DbgVariable &DV, DIE &Die,
729 MachineLocation Location) {
730 if (DV.variableHasComplexAddress())
731 addComplexAddress(DV, Die, dwarf::DW_AT_location, Location);
732 else if (DV.isBlockByrefVariable())
733 addBlockByrefAddress(DV, Die, dwarf::DW_AT_location, Location);
735 addAddress(Die, dwarf::DW_AT_location, Location);
738 /// Add an address attribute to a die based on the location provided.
739 void DwarfCompileUnit::addAddress(DIE &Die, dwarf::Attribute Attribute,
740 const MachineLocation &Location) {
741 DIELoc *Loc = new (DIEValueAllocator) DIELoc();
744 if (Location.isReg())
745 validReg = addRegisterOpPiece(*Loc, Location.getReg());
747 validReg = addRegisterOffset(*Loc, Location.getReg(), Location.getOffset());
752 // Now attach the location information to the DIE.
753 addBlock(Die, Attribute, Loc);
756 /// Start with the address based on the location provided, and generate the
757 /// DWARF information necessary to find the actual variable given the extra
758 /// address information encoded in the DbgVariable, starting from the starting
759 /// location. Add the DWARF information to the die.
760 void DwarfCompileUnit::addComplexAddress(const DbgVariable &DV, DIE &Die,
761 dwarf::Attribute Attribute,
762 const MachineLocation &Location) {
763 DIELoc *Loc = new (DIEValueAllocator) DIELoc();
764 DIEDwarfExpression DwarfExpr(*Asm, *this, *Loc);
765 assert(DV.getExpression().size() == 1);
766 DIExpression Expr = DV.getExpression().back();
768 if (Location.getOffset()) {
769 ValidReg = DwarfExpr.AddMachineRegIndirect(Location.getReg(),
770 Location.getOffset());
772 DwarfExpr.AddExpression(Expr->expr_op_begin(), Expr->expr_op_end());
774 ValidReg = DwarfExpr.AddMachineRegExpression(Expr, Location.getReg());
776 // Now attach the location information to the DIE.
778 addBlock(Die, Attribute, Loc);
781 /// Add a Dwarf loclistptr attribute data and value.
782 void DwarfCompileUnit::addLocationList(DIE &Die, dwarf::Attribute Attribute,
784 DIEValue *Value = new (DIEValueAllocator) DIELocList(Index);
785 dwarf::Form Form = DD->getDwarfVersion() >= 4 ? dwarf::DW_FORM_sec_offset
786 : dwarf::DW_FORM_data4;
787 Die.addValue(Attribute, Form, Value);
790 void DwarfCompileUnit::applyVariableAttributes(const DbgVariable &Var,
792 StringRef Name = Var.getName();
794 addString(VariableDie, dwarf::DW_AT_name, Name);
795 addSourceLine(VariableDie, Var.getVariable());
796 addType(VariableDie, Var.getType());
797 if (Var.isArtificial())
798 addFlag(VariableDie, dwarf::DW_AT_artificial);
801 /// Add a Dwarf expression attribute data and value.
802 void DwarfCompileUnit::addExpr(DIELoc &Die, dwarf::Form Form,
803 const MCExpr *Expr) {
804 DIEValue *Value = new (DIEValueAllocator) DIEExpr(Expr);
805 Die.addValue((dwarf::Attribute)0, Form, Value);
808 void DwarfCompileUnit::applySubprogramAttributesToDefinition(DISubprogram SP,
810 DISubprogram SPDecl = SP.getFunctionDeclaration();
811 DIScope Context = resolve(SPDecl ? SPDecl.getContext() : SP.getContext());
812 applySubprogramAttributes(SP, SPDie, includeMinimalInlineScopes());
813 addGlobalName(SP.getName(), SPDie, Context);
816 bool DwarfCompileUnit::isDwoUnit() const {
817 return DD->useSplitDwarf() && Skeleton;
820 bool DwarfCompileUnit::includeMinimalInlineScopes() const {
821 return getCUNode().getEmissionKind() == DIBuilder::LineTablesOnly ||
822 (DD->useSplitDwarf() && !Skeleton);
824 } // end llvm namespace