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) {
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 DIE *ContextDIE = getOrCreateContextDIE(GVContext);
119 DIE *VariableDIE = &createAndAddDIE(GV->getTag(), *ContextDIE, GV);
120 DIScope *DeclContext;
121 if (auto *SDMDecl = GV->getStaticDataMemberDeclaration()) {
122 DeclContext = resolve(SDMDecl->getScope());
123 assert(SDMDecl->isStaticMember() && "Expected static member decl");
124 assert(GV->isDefinition());
125 // We need the declaration DIE that is in the static member's class.
126 DIE *VariableSpecDIE = getOrCreateStaticMemberDIE(SDMDecl);
127 addDIEEntry(*VariableDIE, dwarf::DW_AT_specification, *VariableSpecDIE);
129 DeclContext = GV->getScope();
130 // Add name and type.
131 addString(*VariableDIE, dwarf::DW_AT_name, GV->getDisplayName());
132 addType(*VariableDIE, GTy);
135 if (!GV->isLocalToUnit())
136 addFlag(*VariableDIE, dwarf::DW_AT_external);
138 // Add line number info.
139 addSourceLine(*VariableDIE, GV);
142 if (!GV->isDefinition())
143 addFlag(*VariableDIE, dwarf::DW_AT_declaration);
145 addGlobalName(GV->getName(), *VariableDIE, DeclContext);
148 bool addToAccelTable = false;
149 if (auto *Global = dyn_cast_or_null<GlobalVariable>(GV->getVariable())) {
150 addToAccelTable = true;
151 DIELoc *Loc = new (DIEValueAllocator) DIELoc;
152 const MCSymbol *Sym = Asm->getSymbol(Global);
153 if (Global->isThreadLocal()) {
154 // FIXME: Make this work with -gsplit-dwarf.
155 unsigned PointerSize = Asm->getDataLayout().getPointerSize();
156 assert((PointerSize == 4 || PointerSize == 8) &&
157 "Add support for other sizes if necessary");
158 // Based on GCC's support for TLS:
159 if (!DD->useSplitDwarf()) {
160 // 1) Start with a constNu of the appropriate pointer size
161 addUInt(*Loc, dwarf::DW_FORM_data1,
162 PointerSize == 4 ? dwarf::DW_OP_const4u : dwarf::DW_OP_const8u);
163 // 2) containing the (relocated) offset of the TLS variable
164 // within the module's TLS block.
165 addExpr(*Loc, dwarf::DW_FORM_udata,
166 Asm->getObjFileLowering().getDebugThreadLocalSymbol(Sym));
168 addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_GNU_const_index);
169 addUInt(*Loc, dwarf::DW_FORM_udata,
170 DD->getAddressPool().getIndex(Sym, /* TLS */ true));
172 // 3) followed by an OP to make the debugger do a TLS lookup.
173 addUInt(*Loc, dwarf::DW_FORM_data1,
174 DD->useGNUTLSOpcode() ? dwarf::DW_OP_GNU_push_tls_address
175 : dwarf::DW_OP_form_tls_address);
177 DD->addArangeLabel(SymbolCU(this, Sym));
178 addOpAddress(*Loc, Sym);
181 addBlock(*VariableDIE, dwarf::DW_AT_location, Loc);
182 addLinkageName(*VariableDIE, GV->getLinkageName());
183 } else if (const ConstantInt *CI =
184 dyn_cast_or_null<ConstantInt>(GV->getVariable())) {
185 addConstantValue(*VariableDIE, CI, GTy);
186 } else if (const ConstantExpr *CE = getMergedGlobalExpr(GV->getVariable())) {
187 addToAccelTable = true;
188 // GV is a merged global.
189 DIELoc *Loc = new (DIEValueAllocator) DIELoc;
190 Value *Ptr = CE->getOperand(0);
191 MCSymbol *Sym = Asm->getSymbol(cast<GlobalValue>(Ptr));
192 DD->addArangeLabel(SymbolCU(this, Sym));
193 addOpAddress(*Loc, Sym);
194 addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_constu);
195 SmallVector<Value *, 3> Idx(CE->op_begin() + 1, CE->op_end());
196 addUInt(*Loc, dwarf::DW_FORM_udata,
197 Asm->getDataLayout().getIndexedOffset(Ptr->getType(), Idx));
198 addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_plus);
199 addBlock(*VariableDIE, dwarf::DW_AT_location, Loc);
202 if (addToAccelTable) {
203 DD->addAccelName(GV->getName(), *VariableDIE);
205 // If the linkage name is different than the name, go ahead and output
206 // that as well into the name table.
207 if (GV->getLinkageName() != "" && GV->getName() != GV->getLinkageName())
208 DD->addAccelName(GV->getLinkageName(), *VariableDIE);
214 void DwarfCompileUnit::addRange(RangeSpan Range) {
215 bool SameAsPrevCU = this == DD->getPrevCU();
217 // If we have no current ranges just add the range and return, otherwise,
218 // check the current section and CU against the previous section and CU we
219 // emitted into and the subprogram was contained within. If these are the
220 // same then extend our current range, otherwise add this as a new range.
221 if (CURanges.empty() || !SameAsPrevCU ||
222 (&CURanges.back().getEnd()->getSection() !=
223 &Range.getEnd()->getSection())) {
224 CURanges.push_back(Range);
228 CURanges.back().setEnd(Range.getEnd());
232 DwarfCompileUnit::addSectionLabel(DIE &Die, dwarf::Attribute Attribute,
233 const MCSymbol *Label, const MCSymbol *Sec) {
234 if (Asm->MAI->doesDwarfUseRelocationsAcrossSections())
235 return addLabel(Die, Attribute,
236 DD->getDwarfVersion() >= 4 ? dwarf::DW_FORM_sec_offset
237 : dwarf::DW_FORM_data4,
239 return addSectionDelta(Die, Attribute, Label, Sec);
242 void DwarfCompileUnit::initStmtList() {
243 // Define start line table label for each Compile Unit.
244 MCSymbol *LineTableStartSym =
245 Asm->OutStreamer->getDwarfLineTableSymbol(getUniqueID());
247 // DW_AT_stmt_list is a offset of line number information for this
248 // compile unit in debug_line section. For split dwarf this is
249 // left in the skeleton CU and so not included.
250 // The line table entries are not always emitted in assembly, so it
251 // is not okay to use line_table_start here.
252 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
254 addSectionLabel(UnitDie, dwarf::DW_AT_stmt_list, LineTableStartSym,
255 TLOF.getDwarfLineSection()->getBeginSymbol());
258 void DwarfCompileUnit::applyStmtList(DIE &D) {
259 D.addValue(DIEValueAllocator, *StmtListValue);
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(const 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<DIE *> &FinalChildren) {
305 if (!Scope || !Scope->getScopeNode())
308 auto *DS = Scope->getScopeNode();
310 assert((Scope->getInlinedAt() || !isa<DISubprogram>(DS)) &&
311 "Only handle inlined subprograms here, use "
312 "constructSubprogramScopeDIE for non-inlined "
315 SmallVector<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.
321 if (Scope->getParent() && isa<DISubprogram>(DS)) {
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(cast<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));
366 DwarfCompileUnit::addSectionDelta(DIE &Die, dwarf::Attribute Attribute,
367 const MCSymbol *Hi, const MCSymbol *Lo) {
368 return Die.addValue(DIEValueAllocator, Attribute,
369 DD->getDwarfVersion() >= 4 ? dwarf::DW_FORM_sec_offset
370 : dwarf::DW_FORM_data4,
371 new (DIEValueAllocator) DIEDelta(Hi, Lo));
374 void DwarfCompileUnit::addScopeRangeList(DIE &ScopeDIE,
375 SmallVector<RangeSpan, 2> Range) {
376 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
378 // Emit offset in .debug_range as a relocatable label. emitDIE will handle
379 // emitting it appropriately.
380 const MCSymbol *RangeSectionSym =
381 TLOF.getDwarfRangesSection()->getBeginSymbol();
383 RangeSpanList List(Asm->createTempSymbol("debug_ranges"), std::move(Range));
385 // Under fission, ranges are specified by constant offsets relative to the
386 // CU's DW_AT_GNU_ranges_base.
388 addSectionDelta(ScopeDIE, dwarf::DW_AT_ranges, List.getSym(),
391 addSectionLabel(ScopeDIE, dwarf::DW_AT_ranges, List.getSym(),
394 // Add the range list to the set of ranges to be emitted.
395 (Skeleton ? Skeleton : this)->CURangeLists.push_back(std::move(List));
398 void DwarfCompileUnit::attachRangesOrLowHighPC(
399 DIE &Die, SmallVector<RangeSpan, 2> Ranges) {
400 if (Ranges.size() == 1) {
401 const auto &single = Ranges.front();
402 attachLowHighPC(Die, single.getStart(), single.getEnd());
404 addScopeRangeList(Die, std::move(Ranges));
407 void DwarfCompileUnit::attachRangesOrLowHighPC(
408 DIE &Die, const SmallVectorImpl<InsnRange> &Ranges) {
409 SmallVector<RangeSpan, 2> List;
410 List.reserve(Ranges.size());
411 for (const InsnRange &R : Ranges)
412 List.push_back(RangeSpan(DD->getLabelBeforeInsn(R.first),
413 DD->getLabelAfterInsn(R.second)));
414 attachRangesOrLowHighPC(Die, std::move(List));
417 // This scope represents inlined body of a function. Construct DIE to
418 // represent this concrete inlined copy of the function.
419 DIE *DwarfCompileUnit::constructInlinedScopeDIE(LexicalScope *Scope) {
420 assert(Scope->getScopeNode());
421 auto *DS = Scope->getScopeNode();
422 auto *InlinedSP = getDISubprogram(DS);
423 // Find the subprogram's DwarfCompileUnit in the SPMap in case the subprogram
424 // was inlined from another compile unit.
425 DIE *OriginDIE = DU->getAbstractSPDies()[InlinedSP];
426 assert(OriginDIE && "Unable to find original DIE for an inlined subprogram.");
428 auto ScopeDIE = DIE::get(DIEValueAllocator, dwarf::DW_TAG_inlined_subroutine);
429 addDIEEntry(*ScopeDIE, dwarf::DW_AT_abstract_origin, *OriginDIE);
431 attachRangesOrLowHighPC(*ScopeDIE, Scope->getRanges());
433 // Add the call site information to the DIE.
434 const DILocation *IA = Scope->getInlinedAt();
435 addUInt(*ScopeDIE, dwarf::DW_AT_call_file, None,
436 getOrCreateSourceID(IA->getFilename(), IA->getDirectory()));
437 addUInt(*ScopeDIE, dwarf::DW_AT_call_line, None, IA->getLine());
439 // Add name to the name table, we do this here because we're guaranteed
440 // to have concrete versions of our DW_TAG_inlined_subprogram nodes.
441 DD->addSubprogramNames(InlinedSP, *ScopeDIE);
446 // Construct new DW_TAG_lexical_block for this scope and attach
447 // DW_AT_low_pc/DW_AT_high_pc labels.
448 DIE *DwarfCompileUnit::constructLexicalScopeDIE(LexicalScope *Scope) {
449 if (DD->isLexicalScopeDIENull(Scope))
452 auto ScopeDIE = DIE::get(DIEValueAllocator, dwarf::DW_TAG_lexical_block);
453 if (Scope->isAbstractScope())
456 attachRangesOrLowHighPC(*ScopeDIE, Scope->getRanges());
461 /// constructVariableDIE - Construct a DIE for the given DbgVariable.
462 DIE *DwarfCompileUnit::constructVariableDIE(DbgVariable &DV, bool Abstract) {
463 auto D = constructVariableDIEImpl(DV, Abstract);
468 DIE *DwarfCompileUnit::constructVariableDIEImpl(const DbgVariable &DV,
470 // Define variable debug information entry.
471 auto VariableDie = DIE::get(DIEValueAllocator, DV.getTag());
474 applyVariableAttributes(DV, *VariableDie);
478 // Add variable address.
480 unsigned Offset = DV.getDebugLocListIndex();
482 addLocationList(*VariableDie, dwarf::DW_AT_location, Offset);
486 // Check if variable is described by a DBG_VALUE instruction.
487 if (const MachineInstr *DVInsn = DV.getMInsn()) {
488 assert(DVInsn->getNumOperands() == 4);
489 if (DVInsn->getOperand(0).isReg()) {
490 const MachineOperand RegOp = DVInsn->getOperand(0);
491 // If the second operand is an immediate, this is an indirect value.
492 if (DVInsn->getOperand(1).isImm()) {
493 MachineLocation Location(RegOp.getReg(),
494 DVInsn->getOperand(1).getImm());
495 addVariableAddress(DV, *VariableDie, Location);
496 } else if (RegOp.getReg())
497 addVariableAddress(DV, *VariableDie, MachineLocation(RegOp.getReg()));
498 } else if (DVInsn->getOperand(0).isImm())
499 addConstantValue(*VariableDie, DVInsn->getOperand(0), DV.getType());
500 else if (DVInsn->getOperand(0).isFPImm())
501 addConstantFPValue(*VariableDie, DVInsn->getOperand(0));
502 else if (DVInsn->getOperand(0).isCImm())
503 addConstantValue(*VariableDie, DVInsn->getOperand(0).getCImm(),
509 // .. else use frame index.
510 if (DV.getFrameIndex().empty())
513 auto Expr = DV.getExpression().begin();
514 DIELoc *Loc = new (DIEValueAllocator) DIELoc;
515 DIEDwarfExpression DwarfExpr(*Asm, *this, *Loc);
516 for (auto FI : DV.getFrameIndex()) {
517 unsigned FrameReg = 0;
518 const TargetFrameLowering *TFI = Asm->MF->getSubtarget().getFrameLowering();
519 int Offset = TFI->getFrameIndexReference(*Asm->MF, FI, FrameReg);
520 assert(Expr != DV.getExpression().end() &&
521 "Wrong number of expressions");
522 DwarfExpr.AddMachineRegIndirect(FrameReg, Offset);
523 DwarfExpr.AddExpression((*Expr)->expr_op_begin(), (*Expr)->expr_op_end());
526 addBlock(*VariableDie, dwarf::DW_AT_location, Loc);
531 DIE *DwarfCompileUnit::constructVariableDIE(DbgVariable &DV,
532 const LexicalScope &Scope,
533 DIE *&ObjectPointer) {
534 auto Var = constructVariableDIE(DV, Scope.isAbstractScope());
535 if (DV.isObjectPointer())
540 DIE *DwarfCompileUnit::createScopeChildrenDIE(LexicalScope *Scope,
541 SmallVectorImpl<DIE *> &Children,
542 unsigned *ChildScopeCount) {
543 DIE *ObjectPointer = nullptr;
545 for (DbgVariable *DV : DU->getScopeVariables().lookup(Scope))
546 Children.push_back(constructVariableDIE(*DV, *Scope, ObjectPointer));
548 unsigned ChildCountWithoutScopes = Children.size();
550 for (LexicalScope *LS : Scope->getChildren())
551 constructScopeDIE(LS, Children);
554 *ChildScopeCount = Children.size() - ChildCountWithoutScopes;
556 return ObjectPointer;
559 void DwarfCompileUnit::constructSubprogramScopeDIE(LexicalScope *Scope) {
560 assert(Scope && Scope->getScopeNode());
561 assert(!Scope->getInlinedAt());
562 assert(!Scope->isAbstractScope());
563 auto *Sub = cast<DISubprogram>(Scope->getScopeNode());
565 DD->getProcessedSPNodes().insert(Sub);
567 DIE &ScopeDIE = updateSubprogramScopeDIE(Sub);
569 // If this is a variadic function, add an unspecified parameter.
570 DITypeRefArray FnArgs = Sub->getType()->getTypeArray();
572 // Collect lexical scope children first.
573 // ObjectPointer might be a local (non-argument) local variable if it's a
574 // block's synthetic this pointer.
575 if (DIE *ObjectPointer = createAndAddScopeChildren(Scope, ScopeDIE))
576 addDIEEntry(ScopeDIE, dwarf::DW_AT_object_pointer, *ObjectPointer);
578 // If we have a single element of null, it is a function that returns void.
579 // If we have more than one elements and the last one is null, it is a
580 // variadic function.
581 if (FnArgs.size() > 1 && !FnArgs[FnArgs.size() - 1] &&
582 !includeMinimalInlineScopes())
584 DIE::get(DIEValueAllocator, dwarf::DW_TAG_unspecified_parameters));
587 DIE *DwarfCompileUnit::createAndAddScopeChildren(LexicalScope *Scope,
589 // We create children when the scope DIE is not null.
590 SmallVector<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 auto *SP = cast<DISubprogram>(Scope->getScopeNode());
610 if (includeMinimalInlineScopes())
611 ContextDIE = &getUnitDie();
612 // Some of this is duplicated from DwarfUnit::getOrCreateSubprogramDIE, with
613 // the important distinction that the debug node is not associated with the
614 // DIE (since the debug node will be associated with the concrete DIE, if
615 // any). It could be refactored to some common utility function.
616 else if (auto *SPDecl = SP->getDeclaration()) {
617 ContextDIE = &getUnitDie();
618 getOrCreateSubprogramDIE(SPDecl);
620 ContextDIE = getOrCreateContextDIE(resolve(SP->getScope()));
622 // Passing null as the associated node because the abstract definition
623 // shouldn't be found by lookup.
624 AbsDef = &createAndAddDIE(dwarf::DW_TAG_subprogram, *ContextDIE, nullptr);
625 applySubprogramAttributesToDefinition(SP, *AbsDef);
627 if (!includeMinimalInlineScopes())
628 addUInt(*AbsDef, dwarf::DW_AT_inline, None, dwarf::DW_INL_inlined);
629 if (DIE *ObjectPointer = createAndAddScopeChildren(Scope, *AbsDef))
630 addDIEEntry(*AbsDef, dwarf::DW_AT_object_pointer, *ObjectPointer);
633 DIE *DwarfCompileUnit::constructImportedEntityDIE(
634 const DIImportedEntity *Module) {
635 DIE *IMDie = DIE::get(DIEValueAllocator, (dwarf::Tag)Module->getTag());
636 insertDIE(Module, IMDie);
638 auto *Entity = resolve(Module->getEntity());
639 if (auto *NS = dyn_cast<DINamespace>(Entity))
640 EntityDie = getOrCreateNameSpace(NS);
641 else if (auto *M = dyn_cast<DIModule>(Entity))
642 EntityDie = getOrCreateModule(M);
643 else if (auto *SP = dyn_cast<DISubprogram>(Entity))
644 EntityDie = getOrCreateSubprogramDIE(SP);
645 else if (auto *T = dyn_cast<DIType>(Entity))
646 EntityDie = getOrCreateTypeDIE(T);
647 else if (auto *GV = dyn_cast<DIGlobalVariable>(Entity))
648 EntityDie = getOrCreateGlobalVariableDIE(GV);
650 EntityDie = getDIE(Entity);
652 addSourceLine(*IMDie, Module->getLine(), Module->getScope()->getFilename(),
653 Module->getScope()->getDirectory());
654 addDIEEntry(*IMDie, dwarf::DW_AT_import, *EntityDie);
655 StringRef Name = Module->getName();
657 addString(*IMDie, dwarf::DW_AT_name, Name);
662 void DwarfCompileUnit::finishSubprogramDefinition(const DISubprogram *SP) {
664 if (DIE *AbsSPDIE = DU->getAbstractSPDies().lookup(SP)) {
666 // If this subprogram has an abstract definition, reference that
667 addDIEEntry(*D, dwarf::DW_AT_abstract_origin, *AbsSPDIE);
669 if (!D && !includeMinimalInlineScopes())
670 // Lazily construct the subprogram if we didn't see either concrete or
671 // inlined versions during codegen. (except in -gmlt ^ where we want
672 // to omit these entirely)
673 D = getOrCreateSubprogramDIE(SP);
675 // And attach the attributes
676 applySubprogramAttributesToDefinition(SP, *D);
679 void DwarfCompileUnit::collectDeadVariables(const DISubprogram *SP) {
680 assert(SP && "CU's subprogram list contains a non-subprogram");
681 assert(SP->isDefinition() &&
682 "CU's subprogram list contains a subprogram declaration");
683 auto Variables = SP->getVariables();
684 if (Variables.size() == 0)
687 DIE *SPDIE = DU->getAbstractSPDies().lookup(SP);
691 for (const DILocalVariable *DV : Variables) {
692 DbgVariable NewVar(DV, /* IA */ nullptr, DD);
693 auto VariableDie = constructVariableDIE(NewVar);
694 applyVariableAttributes(NewVar, *VariableDie);
695 SPDIE->addChild(std::move(VariableDie));
699 void DwarfCompileUnit::emitHeader(bool UseOffsets) {
700 // Don't bother labeling the .dwo unit, as its offset isn't used.
702 LabelBegin = Asm->createTempSymbol("cu_begin");
703 Asm->OutStreamer->EmitLabel(LabelBegin);
706 DwarfUnit::emitHeader(UseOffsets);
709 /// addGlobalName - Add a new global name to the compile unit.
710 void DwarfCompileUnit::addGlobalName(StringRef Name, DIE &Die,
711 const DIScope *Context) {
712 if (includeMinimalInlineScopes())
714 std::string FullName = getParentContextString(Context) + Name.str();
715 GlobalNames[FullName] = &Die;
718 /// Add a new global type to the unit.
719 void DwarfCompileUnit::addGlobalType(const DIType *Ty, const DIE &Die,
720 const DIScope *Context) {
721 if (includeMinimalInlineScopes())
723 std::string FullName = getParentContextString(Context) + Ty->getName().str();
724 GlobalTypes[FullName] = &Die;
727 /// addVariableAddress - Add DW_AT_location attribute for a
728 /// DbgVariable based on provided MachineLocation.
729 void DwarfCompileUnit::addVariableAddress(const DbgVariable &DV, DIE &Die,
730 MachineLocation Location) {
731 if (DV.hasComplexAddress())
732 addComplexAddress(DV, Die, dwarf::DW_AT_location, Location);
733 else if (DV.isBlockByrefVariable())
734 addBlockByrefAddress(DV, Die, dwarf::DW_AT_location, Location);
736 addAddress(Die, dwarf::DW_AT_location, Location);
739 /// Add an address attribute to a die based on the location provided.
740 void DwarfCompileUnit::addAddress(DIE &Die, dwarf::Attribute Attribute,
741 const MachineLocation &Location) {
742 DIELoc *Loc = new (DIEValueAllocator) DIELoc;
745 if (Location.isReg())
746 validReg = addRegisterOpPiece(*Loc, Location.getReg());
748 validReg = addRegisterOffset(*Loc, Location.getReg(), Location.getOffset());
753 // Now attach the location information to the DIE.
754 addBlock(Die, Attribute, Loc);
757 /// Start with the address based on the location provided, and generate the
758 /// DWARF information necessary to find the actual variable given the extra
759 /// address information encoded in the DbgVariable, starting from the starting
760 /// location. Add the DWARF information to the die.
761 void DwarfCompileUnit::addComplexAddress(const DbgVariable &DV, DIE &Die,
762 dwarf::Attribute Attribute,
763 const MachineLocation &Location) {
764 DIELoc *Loc = new (DIEValueAllocator) DIELoc;
765 DIEDwarfExpression DwarfExpr(*Asm, *this, *Loc);
766 assert(DV.getExpression().size() == 1);
767 const DIExpression *Expr = DV.getExpression().back();
769 if (Location.getOffset()) {
770 ValidReg = DwarfExpr.AddMachineRegIndirect(Location.getReg(),
771 Location.getOffset());
773 DwarfExpr.AddExpression(Expr->expr_op_begin(), Expr->expr_op_end());
775 ValidReg = DwarfExpr.AddMachineRegExpression(Expr, Location.getReg());
777 // Now attach the location information to the DIE.
779 addBlock(Die, Attribute, Loc);
782 /// Add a Dwarf loclistptr attribute data and value.
783 void DwarfCompileUnit::addLocationList(DIE &Die, dwarf::Attribute Attribute,
785 dwarf::Form Form = DD->getDwarfVersion() >= 4 ? dwarf::DW_FORM_sec_offset
786 : dwarf::DW_FORM_data4;
787 Die.addValue(DIEValueAllocator, Attribute, Form, DIELocList(Index));
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 Die.addValue(DIEValueAllocator, (dwarf::Attribute)0, Form, DIEExpr(Expr));
807 void DwarfCompileUnit::applySubprogramAttributesToDefinition(
808 const DISubprogram *SP, DIE &SPDie) {
809 auto *SPDecl = SP->getDeclaration();
810 auto *Context = resolve(SPDecl ? SPDecl->getScope() : SP->getScope());
811 applySubprogramAttributes(SP, SPDie, includeMinimalInlineScopes());
812 addGlobalName(SP->getName(), SPDie, Context);
815 bool DwarfCompileUnit::isDwoUnit() const {
816 return DD->useSplitDwarf() && Skeleton;
819 bool DwarfCompileUnit::includeMinimalInlineScopes() const {
820 return getCUNode()->getEmissionKind() == DIBuilder::LineTablesOnly ||
821 (DD->useSplitDwarf() && !Skeleton);
823 } // end llvm namespace