1 #include "DwarfCompileUnit.h"
2 #include "DwarfExpression.h"
3 #include "llvm/CodeGen/MachineFunction.h"
4 #include "llvm/IR/Constants.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/TargetRegisterInfo.h"
15 #include "llvm/Target/TargetSubtargetInfo.h"
19 DwarfCompileUnit::DwarfCompileUnit(unsigned UID, const DICompileUnit *Node,
20 AsmPrinter *A, DwarfDebug *DW,
22 : DwarfUnit(UID, dwarf::DW_TAG_compile_unit, Node, A, DW, DWU),
23 Skeleton(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 Die.addValue(DIEValueAllocator, Attribute, dwarf::DW_FORM_GNU_addr_index,
49 void DwarfCompileUnit::addLocalLabelAddress(DIE &Die,
50 dwarf::Attribute Attribute,
51 const MCSymbol *Label) {
53 DD->addArangeLabel(SymbolCU(this, Label));
56 Die.addValue(DIEValueAllocator, Attribute, dwarf::DW_FORM_addr,
59 Die.addValue(DIEValueAllocator, Attribute, dwarf::DW_FORM_addr,
63 unsigned DwarfCompileUnit::getOrCreateSourceID(StringRef FileName,
65 // If we print assembly, we can't separate .file entries according to
66 // compile units. Thus all files will belong to the default compile unit.
68 // FIXME: add a better feature test than hasRawTextSupport. Even better,
69 // extend .file to support this.
70 return Asm->OutStreamer->EmitDwarfFileDirective(
72 Asm->OutStreamer->hasRawTextSupport() ? 0 : getUniqueID());
75 // Return const expression if value is a GEP to access merged global
77 // i8* getelementptr ({ i8, i8, i8, i8 }* @_MergedGlobals, i32 0, i32 0)
78 static const ConstantExpr *getMergedGlobalExpr(const Value *V) {
79 const ConstantExpr *CE = dyn_cast_or_null<ConstantExpr>(V);
80 if (!CE || CE->getNumOperands() != 3 ||
81 CE->getOpcode() != Instruction::GetElementPtr)
84 // First operand points to a global struct.
85 Value *Ptr = CE->getOperand(0);
86 if (!isa<GlobalValue>(Ptr) ||
87 !isa<StructType>(cast<PointerType>(Ptr->getType())->getElementType()))
90 // Second operand is zero.
91 const ConstantInt *CI = dyn_cast_or_null<ConstantInt>(CE->getOperand(1));
92 if (!CI || !CI->isZero())
95 // Third operand is offset.
96 if (!isa<ConstantInt>(CE->getOperand(2)))
102 /// getOrCreateGlobalVariableDIE - get or create global variable DIE.
103 DIE *DwarfCompileUnit::getOrCreateGlobalVariableDIE(
104 const DIGlobalVariable *GV, DIE *ContextDIE) {
105 // Check for pre-existence.
106 if (DIE *Die = getDIE(GV))
111 auto *GVContext = GV->getScope();
112 auto *GTy = DD->resolve(GV->getType());
114 // Construct the context before querying for the existence of the DIE in
115 // case such construction creates the DIE.
116 if (ContextDIE == nullptr)
117 ContextDIE = getOrCreateContextDIE(GVContext);
120 DIE *VariableDIE = &createAndAddDIE(GV->getTag(), *ContextDIE, GV);
121 DIScope *DeclContext;
122 if (auto *SDMDecl = GV->getStaticDataMemberDeclaration()) {
123 DeclContext = resolve(SDMDecl->getScope());
124 assert(SDMDecl->isStaticMember() && "Expected static member decl");
125 assert(GV->isDefinition());
126 // We need the declaration DIE that is in the static member's class.
127 DIE *VariableSpecDIE = getOrCreateStaticMemberDIE(SDMDecl);
128 addDIEEntry(*VariableDIE, dwarf::DW_AT_specification, *VariableSpecDIE);
130 DeclContext = GV->getScope();
131 // Add name and type.
132 addString(*VariableDIE, dwarf::DW_AT_name, GV->getDisplayName());
133 addType(*VariableDIE, GTy);
136 if (!GV->isLocalToUnit())
137 addFlag(*VariableDIE, dwarf::DW_AT_external);
139 // Add line number info.
140 addSourceLine(*VariableDIE, GV);
143 if (!GV->isDefinition())
144 addFlag(*VariableDIE, dwarf::DW_AT_declaration);
146 addGlobalName(GV->getName(), *VariableDIE, DeclContext);
149 bool addToAccelTable = false;
150 if (auto *Global = dyn_cast_or_null<GlobalVariable>(GV->getVariable())) {
151 addToAccelTable = true;
152 DIELoc *Loc = new (DIEValueAllocator) DIELoc;
153 const MCSymbol *Sym = Asm->getSymbol(Global);
154 if (Global->isThreadLocal()) {
155 // FIXME: Make this work with -gsplit-dwarf.
156 unsigned PointerSize = Asm->getDataLayout().getPointerSize();
157 assert((PointerSize == 4 || PointerSize == 8) &&
158 "Add support for other sizes if necessary");
159 // Based on GCC's support for TLS:
160 if (!DD->useSplitDwarf()) {
161 // 1) Start with a constNu of the appropriate pointer size
162 addUInt(*Loc, dwarf::DW_FORM_data1,
163 PointerSize == 4 ? dwarf::DW_OP_const4u : dwarf::DW_OP_const8u);
164 // 2) containing the (relocated) offset of the TLS variable
165 // within the module's TLS block.
166 addExpr(*Loc, dwarf::DW_FORM_udata,
167 Asm->getObjFileLowering().getDebugThreadLocalSymbol(Sym));
169 addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_GNU_const_index);
170 addUInt(*Loc, dwarf::DW_FORM_udata,
171 DD->getAddressPool().getIndex(Sym, /* TLS */ true));
173 // 3) followed by an OP to make the debugger do a TLS lookup.
174 addUInt(*Loc, dwarf::DW_FORM_data1,
175 DD->useGNUTLSOpcode() ? dwarf::DW_OP_GNU_push_tls_address
176 : dwarf::DW_OP_form_tls_address);
178 DD->addArangeLabel(SymbolCU(this, Sym));
179 addOpAddress(*Loc, Sym);
182 addBlock(*VariableDIE, dwarf::DW_AT_location, Loc);
183 addLinkageName(*VariableDIE, GV->getLinkageName());
184 } else if (const ConstantInt *CI =
185 dyn_cast_or_null<ConstantInt>(GV->getVariable())) {
186 addConstantValue(*VariableDIE, CI, GTy);
187 } else if (const ConstantExpr *CE = getMergedGlobalExpr(GV->getVariable())) {
188 addToAccelTable = true;
189 // GV is a merged global.
190 DIELoc *Loc = new (DIEValueAllocator) DIELoc;
191 Value *Ptr = CE->getOperand(0);
192 MCSymbol *Sym = Asm->getSymbol(cast<GlobalValue>(Ptr));
193 DD->addArangeLabel(SymbolCU(this, Sym));
194 addOpAddress(*Loc, Sym);
195 addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_constu);
196 SmallVector<Value *, 3> Idx(CE->op_begin() + 1, CE->op_end());
197 addUInt(*Loc, dwarf::DW_FORM_udata,
198 Asm->getDataLayout().getIndexedOffset(Ptr->getType(), Idx));
199 addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_plus);
200 addBlock(*VariableDIE, dwarf::DW_AT_location, Loc);
203 if (addToAccelTable) {
204 DD->addAccelName(GV->getName(), *VariableDIE);
206 // If the linkage name is different than the name, go ahead and output
207 // that as well into the name table.
208 if (GV->getLinkageName() != "" && GV->getName() != GV->getLinkageName())
209 DD->addAccelName(GV->getLinkageName(), *VariableDIE);
215 void DwarfCompileUnit::addRange(RangeSpan Range) {
216 bool SameAsPrevCU = this == DD->getPrevCU();
218 // If we have no current ranges just add the range and return, otherwise,
219 // check the current section and CU against the previous section and CU we
220 // emitted into and the subprogram was contained within. If these are the
221 // same then extend our current range, otherwise add this as a new range.
222 if (CURanges.empty() || !SameAsPrevCU ||
223 (&CURanges.back().getEnd()->getSection() !=
224 &Range.getEnd()->getSection())) {
225 CURanges.push_back(Range);
229 CURanges.back().setEnd(Range.getEnd());
233 DwarfCompileUnit::addSectionLabel(DIE &Die, dwarf::Attribute Attribute,
234 const MCSymbol *Label, const MCSymbol *Sec) {
235 if (Asm->MAI->doesDwarfUseRelocationsAcrossSections())
236 return addLabel(Die, Attribute,
237 DD->getDwarfVersion() >= 4 ? dwarf::DW_FORM_sec_offset
238 : dwarf::DW_FORM_data4,
240 return addSectionDelta(Die, Attribute, Label, Sec);
243 void DwarfCompileUnit::initStmtList() {
244 // Define start line table label for each Compile Unit.
245 MCSymbol *LineTableStartSym =
246 Asm->OutStreamer->getDwarfLineTableSymbol(getUniqueID());
248 // DW_AT_stmt_list is a offset of line number information for this
249 // compile unit in debug_line section. For split dwarf this is
250 // left in the skeleton CU and so not included.
251 // The line table entries are not always emitted in assembly, so it
252 // is not okay to use line_table_start here.
253 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
255 addSectionLabel(UnitDie, dwarf::DW_AT_stmt_list, LineTableStartSym,
256 TLOF.getDwarfLineSection()->getBeginSymbol());
259 void DwarfCompileUnit::applyStmtList(DIE &D) {
260 D.addValue(DIEValueAllocator, *StmtListValue);
263 void DwarfCompileUnit::attachLowHighPC(DIE &D, const MCSymbol *Begin,
264 const MCSymbol *End) {
265 assert(Begin && "Begin label should not be null!");
266 assert(End && "End label should not be null!");
267 assert(Begin->isDefined() && "Invalid starting label");
268 assert(End->isDefined() && "Invalid end label");
270 addLabelAddress(D, dwarf::DW_AT_low_pc, Begin);
271 if (DD->getDwarfVersion() < 4)
272 addLabelAddress(D, dwarf::DW_AT_high_pc, End);
274 addLabelDelta(D, dwarf::DW_AT_high_pc, End, Begin);
277 // Find DIE for the given subprogram and attach appropriate DW_AT_low_pc
278 // and DW_AT_high_pc attributes. If there are global variables in this
279 // scope then create and insert DIEs for these variables.
280 DIE &DwarfCompileUnit::updateSubprogramScopeDIE(const DISubprogram *SP) {
281 DIE *SPDie = getOrCreateSubprogramDIE(SP, includeMinimalInlineScopes());
283 attachLowHighPC(*SPDie, Asm->getFunctionBegin(), Asm->getFunctionEnd());
284 if (!DD->getCurrentFunction()->getTarget().Options.DisableFramePointerElim(
285 *DD->getCurrentFunction()))
286 addFlag(*SPDie, dwarf::DW_AT_APPLE_omit_frame_ptr);
288 // Only include DW_AT_frame_base in full debug info
289 if (!includeMinimalInlineScopes()) {
290 const TargetRegisterInfo *RI = Asm->MF->getSubtarget().getRegisterInfo();
291 MachineLocation Location(RI->getFrameRegister(*Asm->MF));
292 if (RI->isPhysicalRegister(Location.getReg()))
293 addAddress(*SPDie, dwarf::DW_AT_frame_base, Location);
296 // Add name to the name table, we do this here because we're guaranteed
297 // to have concrete versions of our DW_TAG_subprogram nodes.
298 DD->addSubprogramNames(SP, *SPDie);
303 // Construct a DIE for this scope.
304 void DwarfCompileUnit::constructScopeDIE(
305 LexicalScope *Scope, SmallVectorImpl<DIE *> &FinalChildren) {
306 if (!Scope || !Scope->getScopeNode())
309 auto *DS = Scope->getScopeNode();
311 assert((Scope->getInlinedAt() || !isa<DISubprogram>(DS)) &&
312 "Only handle inlined subprograms here, use "
313 "constructSubprogramScopeDIE for non-inlined "
316 SmallVector<DIE *, 8> Children;
318 // We try to create the scope DIE first, then the children DIEs. This will
319 // avoid creating un-used children then removing them later when we find out
320 // the scope DIE is null.
322 if (Scope->getParent() && isa<DISubprogram>(DS)) {
323 ScopeDIE = constructInlinedScopeDIE(Scope);
326 // We create children when the scope DIE is not null.
327 createScopeChildrenDIE(Scope, Children);
329 // Early exit when we know the scope DIE is going to be null.
330 if (DD->isLexicalScopeDIENull(Scope))
333 unsigned ChildScopeCount;
335 // We create children here when we know the scope DIE is not going to be
336 // null and the children will be added to the scope DIE.
337 createScopeChildrenDIE(Scope, Children, &ChildScopeCount);
340 DwarfDebug::LocalDeclMapRange LocalDeclNodeRangeForScope(nullptr, nullptr);
341 // Skip local decls in gmlt-like data.
342 if (!includeMinimalInlineScopes())
343 LocalDeclNodeRangeForScope = DD->findLocalDeclNodesForScope(DS);
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 empty(LocalDeclNodeRangeForScope)) {
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.");
357 for (const auto &DI : LocalDeclNodeRangeForScope) {
358 if (auto *IE = dyn_cast<DIImportedEntity>(DI.second))
359 Children.push_back(constructImportedEntityDIE(IE));
360 else if (auto *GV = dyn_cast<DIGlobalVariable>(DI.second))
361 getOrCreateGlobalVariableDIE(GV, ScopeDIE);
362 else if (auto *RT = dyn_cast<DIType>(DI.second))
363 getOrCreateTypeDIE(RT, ScopeDIE);
368 for (auto &I : Children)
369 ScopeDIE->addChild(std::move(I));
371 FinalChildren.push_back(std::move(ScopeDIE));
375 DwarfCompileUnit::addSectionDelta(DIE &Die, dwarf::Attribute Attribute,
376 const MCSymbol *Hi, const MCSymbol *Lo) {
377 return Die.addValue(DIEValueAllocator, Attribute,
378 DD->getDwarfVersion() >= 4 ? dwarf::DW_FORM_sec_offset
379 : dwarf::DW_FORM_data4,
380 new (DIEValueAllocator) DIEDelta(Hi, Lo));
383 void DwarfCompileUnit::addScopeRangeList(DIE &ScopeDIE,
384 SmallVector<RangeSpan, 2> Range) {
385 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
387 // Emit offset in .debug_range as a relocatable label. emitDIE will handle
388 // emitting it appropriately.
389 const MCSymbol *RangeSectionSym =
390 TLOF.getDwarfRangesSection()->getBeginSymbol();
392 RangeSpanList List(Asm->createTempSymbol("debug_ranges"), std::move(Range));
394 // Under fission, ranges are specified by constant offsets relative to the
395 // CU's DW_AT_GNU_ranges_base.
397 addSectionDelta(ScopeDIE, dwarf::DW_AT_ranges, List.getSym(),
400 addSectionLabel(ScopeDIE, dwarf::DW_AT_ranges, List.getSym(),
403 // Add the range list to the set of ranges to be emitted.
404 (Skeleton ? Skeleton : this)->CURangeLists.push_back(std::move(List));
407 void DwarfCompileUnit::attachRangesOrLowHighPC(
408 DIE &Die, SmallVector<RangeSpan, 2> Ranges) {
409 if (Ranges.size() == 1) {
410 const auto &single = Ranges.front();
411 attachLowHighPC(Die, single.getStart(), single.getEnd());
413 addScopeRangeList(Die, std::move(Ranges));
416 void DwarfCompileUnit::attachRangesOrLowHighPC(
417 DIE &Die, const SmallVectorImpl<InsnRange> &Ranges) {
418 SmallVector<RangeSpan, 2> List;
419 List.reserve(Ranges.size());
420 for (const InsnRange &R : Ranges)
421 List.push_back(RangeSpan(DD->getLabelBeforeInsn(R.first),
422 DD->getLabelAfterInsn(R.second)));
423 attachRangesOrLowHighPC(Die, std::move(List));
426 // This scope represents inlined body of a function. Construct DIE to
427 // represent this concrete inlined copy of the function.
428 DIE *DwarfCompileUnit::constructInlinedScopeDIE(LexicalScope *Scope) {
429 assert(Scope->getScopeNode());
430 auto *DS = Scope->getScopeNode();
431 auto *InlinedSP = getDISubprogram(DS);
432 // Find the subprogram's DwarfCompileUnit in the SPMap in case the subprogram
433 // was inlined from another compile unit.
434 DIE *OriginDIE = DU->getAbstractSPDies()[InlinedSP];
435 assert(OriginDIE && "Unable to find original DIE for an inlined subprogram.");
437 auto ScopeDIE = DIE::get(DIEValueAllocator, dwarf::DW_TAG_inlined_subroutine);
438 addDIEEntry(*ScopeDIE, dwarf::DW_AT_abstract_origin, *OriginDIE);
440 attachRangesOrLowHighPC(*ScopeDIE, Scope->getRanges());
442 // Add the call site information to the DIE.
443 const DILocation *IA = Scope->getInlinedAt();
444 addUInt(*ScopeDIE, dwarf::DW_AT_call_file, None,
445 getOrCreateSourceID(IA->getFilename(), IA->getDirectory()));
446 addUInt(*ScopeDIE, dwarf::DW_AT_call_line, None, IA->getLine());
448 // Add name to the name table, we do this here because we're guaranteed
449 // to have concrete versions of our DW_TAG_inlined_subprogram nodes.
450 DD->addSubprogramNames(InlinedSP, *ScopeDIE);
455 // Construct new DW_TAG_lexical_block for this scope and attach
456 // DW_AT_low_pc/DW_AT_high_pc labels.
457 DIE *DwarfCompileUnit::constructLexicalScopeDIE(LexicalScope *Scope) {
458 if (DD->isLexicalScopeDIENull(Scope))
461 auto ScopeDIE = DIE::get(DIEValueAllocator, dwarf::DW_TAG_lexical_block);
462 if (Scope->isAbstractScope())
465 attachRangesOrLowHighPC(*ScopeDIE, Scope->getRanges());
470 /// constructVariableDIE - Construct a DIE for the given DbgVariable.
471 DIE *DwarfCompileUnit::constructVariableDIE(DbgVariable &DV, bool Abstract) {
472 auto D = constructVariableDIEImpl(DV, Abstract);
477 DIE *DwarfCompileUnit::constructVariableDIEImpl(const DbgVariable &DV,
479 // Define variable debug information entry.
480 auto VariableDie = DIE::get(DIEValueAllocator, DV.getTag());
483 applyVariableAttributes(DV, *VariableDie);
487 // Add variable address.
489 unsigned Offset = DV.getDebugLocListIndex();
491 addLocationList(*VariableDie, dwarf::DW_AT_location, Offset);
495 // Check if variable is described by a DBG_VALUE instruction.
496 if (const MachineInstr *DVInsn = DV.getMInsn()) {
497 assert(DVInsn->getNumOperands() == 4);
498 if (DVInsn->getOperand(0).isReg()) {
499 const MachineOperand RegOp = DVInsn->getOperand(0);
500 // If the second operand is an immediate, this is an indirect value.
501 if (DVInsn->getOperand(1).isImm()) {
502 MachineLocation Location(RegOp.getReg(),
503 DVInsn->getOperand(1).getImm());
504 addVariableAddress(DV, *VariableDie, Location);
505 } else if (RegOp.getReg())
506 addVariableAddress(DV, *VariableDie, MachineLocation(RegOp.getReg()));
507 } else if (DVInsn->getOperand(0).isImm())
508 addConstantValue(*VariableDie, DVInsn->getOperand(0), DV.getType());
509 else if (DVInsn->getOperand(0).isFPImm())
510 addConstantFPValue(*VariableDie, DVInsn->getOperand(0));
511 else if (DVInsn->getOperand(0).isCImm())
512 addConstantValue(*VariableDie, DVInsn->getOperand(0).getCImm(),
518 // .. else use frame index.
519 if (DV.getFrameIndex().empty())
522 auto Expr = DV.getExpression().begin();
523 DIELoc *Loc = new (DIEValueAllocator) DIELoc;
524 DIEDwarfExpression DwarfExpr(*Asm, *this, *Loc);
525 for (auto FI : DV.getFrameIndex()) {
526 unsigned FrameReg = 0;
527 const TargetFrameLowering *TFI = Asm->MF->getSubtarget().getFrameLowering();
528 int Offset = TFI->getFrameIndexReference(*Asm->MF, FI, FrameReg);
529 assert(Expr != DV.getExpression().end() &&
530 "Wrong number of expressions");
531 DwarfExpr.AddMachineRegIndirect(FrameReg, Offset);
532 DwarfExpr.AddExpression((*Expr)->expr_op_begin(), (*Expr)->expr_op_end());
535 addBlock(*VariableDie, dwarf::DW_AT_location, Loc);
540 DIE *DwarfCompileUnit::constructVariableDIE(DbgVariable &DV,
541 const LexicalScope &Scope,
542 DIE *&ObjectPointer) {
543 auto Var = constructVariableDIE(DV, Scope.isAbstractScope());
544 if (DV.isObjectPointer())
549 DIE *DwarfCompileUnit::createScopeChildrenDIE(LexicalScope *Scope,
550 SmallVectorImpl<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 auto *Sub = cast<DISubprogram>(Scope->getScopeNode());
574 DD->getProcessedSPNodes().insert(Sub);
576 DIE &ScopeDIE = updateSubprogramScopeDIE(Sub);
578 // If this is a variadic function, add an unspecified parameter.
579 DITypeRefArray FnArgs = Sub->getType()->getTypeArray();
581 // Collect lexical scope children first.
582 // ObjectPointer might be a local (non-argument) local variable if it's a
583 // block's synthetic this pointer.
584 if (DIE *ObjectPointer = createAndAddScopeChildren(Scope, ScopeDIE))
585 addDIEEntry(ScopeDIE, dwarf::DW_AT_object_pointer, *ObjectPointer);
587 // If we have a single element of null, it is a function that returns void.
588 // If we have more than one elements and the last one is null, it is a
589 // variadic function.
590 if (FnArgs.size() > 1 && !FnArgs[FnArgs.size() - 1] &&
591 !includeMinimalInlineScopes())
593 DIE::get(DIEValueAllocator, dwarf::DW_TAG_unspecified_parameters));
596 DIE *DwarfCompileUnit::createAndAddScopeChildren(LexicalScope *Scope,
598 // We create children when the scope DIE is not null.
599 SmallVector<DIE *, 8> Children;
600 DIE *ObjectPointer = createScopeChildrenDIE(Scope, Children);
603 for (auto &I : Children)
604 ScopeDIE.addChild(std::move(I));
606 return ObjectPointer;
610 DwarfCompileUnit::constructAbstractSubprogramScopeDIE(LexicalScope *Scope) {
611 DIE *&AbsDef = DU->getAbstractSPDies()[Scope->getScopeNode()];
615 auto *SP = cast<DISubprogram>(Scope->getScopeNode());
619 if (includeMinimalInlineScopes())
620 ContextDIE = &getUnitDie();
621 // Some of this is duplicated from DwarfUnit::getOrCreateSubprogramDIE, with
622 // the important distinction that the debug node is not associated with the
623 // DIE (since the debug node will be associated with the concrete DIE, if
624 // any). It could be refactored to some common utility function.
625 else if (auto *SPDecl = SP->getDeclaration()) {
626 ContextDIE = &getUnitDie();
627 getOrCreateSubprogramDIE(SPDecl);
629 ContextDIE = getOrCreateContextDIE(resolve(SP->getScope()));
631 // Passing null as the associated node because the abstract definition
632 // shouldn't be found by lookup.
633 AbsDef = &createAndAddDIE(dwarf::DW_TAG_subprogram, *ContextDIE, nullptr);
634 applySubprogramAttributesToDefinition(SP, *AbsDef);
636 if (!includeMinimalInlineScopes())
637 addUInt(*AbsDef, dwarf::DW_AT_inline, None, dwarf::DW_INL_inlined);
638 if (DIE *ObjectPointer = createAndAddScopeChildren(Scope, *AbsDef))
639 addDIEEntry(*AbsDef, dwarf::DW_AT_object_pointer, *ObjectPointer);
642 DIE *DwarfCompileUnit::constructImportedEntityDIE(
643 const DIImportedEntity *Module) {
644 DIE *IMDie = DIE::get(DIEValueAllocator, (dwarf::Tag)Module->getTag());
645 insertDIE(Module, IMDie);
647 auto *Entity = resolve(Module->getEntity());
648 if (auto *NS = dyn_cast<DINamespace>(Entity))
649 EntityDie = getOrCreateNameSpace(NS);
650 else if (auto *M = dyn_cast<DIModule>(Entity))
651 EntityDie = getOrCreateModule(M);
652 else if (auto *SP = dyn_cast<DISubprogram>(Entity))
653 EntityDie = getOrCreateSubprogramDIE(SP);
654 else if (auto *T = dyn_cast<DIType>(Entity))
655 EntityDie = getOrCreateTypeDIE(T);
656 else if (auto *GV = dyn_cast<DIGlobalVariable>(Entity))
657 EntityDie = getOrCreateGlobalVariableDIE(GV);
659 EntityDie = getDIE(Entity);
661 addSourceLine(*IMDie, Module->getLine(), Module->getScope()->getFilename(),
662 Module->getScope()->getDirectory());
663 addDIEEntry(*IMDie, dwarf::DW_AT_import, *EntityDie);
664 StringRef Name = Module->getName();
666 addString(*IMDie, dwarf::DW_AT_name, Name);
671 void DwarfCompileUnit::finishSubprogramDefinition(const DISubprogram *SP) {
673 if (DIE *AbsSPDIE = DU->getAbstractSPDies().lookup(SP)) {
675 // If this subprogram has an abstract definition, reference that
676 addDIEEntry(*D, dwarf::DW_AT_abstract_origin, *AbsSPDIE);
678 if (!D && !includeMinimalInlineScopes())
679 // Lazily construct the subprogram if we didn't see either concrete or
680 // inlined versions during codegen. (except in -gmlt ^ where we want
681 // to omit these entirely)
682 D = getOrCreateSubprogramDIE(SP);
684 // And attach the attributes
685 applySubprogramAttributesToDefinition(SP, *D);
688 void DwarfCompileUnit::collectDeadVariables(const DISubprogram *SP) {
689 assert(SP && "CU's subprogram list contains a non-subprogram");
690 assert(SP->isDefinition() &&
691 "CU's subprogram list contains a subprogram declaration");
692 auto Variables = SP->getVariables();
693 if (Variables.size() == 0)
696 DIE *SPDIE = DU->getAbstractSPDies().lookup(SP);
700 for (const DILocalVariable *DV : Variables) {
701 DbgVariable NewVar(DV, /* IA */ nullptr, DD);
702 auto VariableDie = constructVariableDIE(NewVar);
703 applyVariableAttributes(NewVar, *VariableDie);
704 SPDIE->addChild(std::move(VariableDie));
708 void DwarfCompileUnit::emitHeader(bool UseOffsets) {
709 // Don't bother labeling the .dwo unit, as its offset isn't used.
711 LabelBegin = Asm->createTempSymbol("cu_begin");
712 Asm->OutStreamer->EmitLabel(LabelBegin);
715 DwarfUnit::emitHeader(UseOffsets);
718 /// addGlobalName - Add a new global name to the compile unit.
719 void DwarfCompileUnit::addGlobalName(StringRef Name, DIE &Die,
720 const DIScope *Context) {
721 if (includeMinimalInlineScopes())
723 std::string FullName = getParentContextString(Context) + Name.str();
724 GlobalNames[FullName] = &Die;
727 /// Add a new global type to the unit.
728 void DwarfCompileUnit::addGlobalType(const DIType *Ty, const DIE &Die,
729 const DIScope *Context) {
730 if (includeMinimalInlineScopes())
732 std::string FullName = getParentContextString(Context) + Ty->getName().str();
733 GlobalTypes[FullName] = &Die;
736 /// addVariableAddress - Add DW_AT_location attribute for a
737 /// DbgVariable based on provided MachineLocation.
738 void DwarfCompileUnit::addVariableAddress(const DbgVariable &DV, DIE &Die,
739 MachineLocation Location) {
740 if (DV.hasComplexAddress())
741 addComplexAddress(DV, Die, dwarf::DW_AT_location, Location);
742 else if (DV.isBlockByrefVariable())
743 addBlockByrefAddress(DV, Die, dwarf::DW_AT_location, Location);
745 addAddress(Die, dwarf::DW_AT_location, Location);
748 /// Add an address attribute to a die based on the location provided.
749 void DwarfCompileUnit::addAddress(DIE &Die, dwarf::Attribute Attribute,
750 const MachineLocation &Location) {
751 DIELoc *Loc = new (DIEValueAllocator) DIELoc;
754 if (Location.isReg())
755 validReg = addRegisterOpPiece(*Loc, Location.getReg());
757 validReg = addRegisterOffset(*Loc, Location.getReg(), Location.getOffset());
762 // Now attach the location information to the DIE.
763 addBlock(Die, Attribute, Loc);
766 /// Start with the address based on the location provided, and generate the
767 /// DWARF information necessary to find the actual variable given the extra
768 /// address information encoded in the DbgVariable, starting from the starting
769 /// location. Add the DWARF information to the die.
770 void DwarfCompileUnit::addComplexAddress(const DbgVariable &DV, DIE &Die,
771 dwarf::Attribute Attribute,
772 const MachineLocation &Location) {
773 DIELoc *Loc = new (DIEValueAllocator) DIELoc;
774 DIEDwarfExpression DwarfExpr(*Asm, *this, *Loc);
775 assert(DV.getExpression().size() == 1);
776 const DIExpression *Expr = DV.getExpression().back();
778 if (Location.getOffset()) {
779 ValidReg = DwarfExpr.AddMachineRegIndirect(Location.getReg(),
780 Location.getOffset());
782 DwarfExpr.AddExpression(Expr->expr_op_begin(), Expr->expr_op_end());
784 ValidReg = DwarfExpr.AddMachineRegExpression(Expr, Location.getReg());
786 // Now attach the location information to the DIE.
788 addBlock(Die, Attribute, Loc);
791 /// Add a Dwarf loclistptr attribute data and value.
792 void DwarfCompileUnit::addLocationList(DIE &Die, dwarf::Attribute Attribute,
794 dwarf::Form Form = DD->getDwarfVersion() >= 4 ? dwarf::DW_FORM_sec_offset
795 : dwarf::DW_FORM_data4;
796 Die.addValue(DIEValueAllocator, Attribute, Form, DIELocList(Index));
799 void DwarfCompileUnit::applyVariableAttributes(const DbgVariable &Var,
801 StringRef Name = Var.getName();
803 addString(VariableDie, dwarf::DW_AT_name, Name);
804 addSourceLine(VariableDie, Var.getVariable());
805 addType(VariableDie, Var.getType());
806 if (Var.isArtificial())
807 addFlag(VariableDie, dwarf::DW_AT_artificial);
810 /// Add a Dwarf expression attribute data and value.
811 void DwarfCompileUnit::addExpr(DIELoc &Die, dwarf::Form Form,
812 const MCExpr *Expr) {
813 Die.addValue(DIEValueAllocator, (dwarf::Attribute)0, Form, DIEExpr(Expr));
816 void DwarfCompileUnit::applySubprogramAttributesToDefinition(
817 const DISubprogram *SP, DIE &SPDie) {
818 auto *SPDecl = SP->getDeclaration();
819 auto *Context = resolve(SPDecl ? SPDecl->getScope() : SP->getScope());
820 applySubprogramAttributes(SP, SPDie, includeMinimalInlineScopes());
821 addGlobalName(SP->getName(), SPDie, Context);
824 bool DwarfCompileUnit::isDwoUnit() const {
825 return DD->useSplitDwarf() && Skeleton;
828 bool DwarfCompileUnit::includeMinimalInlineScopes() const {
829 return getCUNode()->getEmissionKind() == DIBuilder::LineTablesOnly ||
830 (DD->useSplitDwarf() && !Skeleton);
832 } // end llvm namespace