1 //===-- llvm/CodeGen/DwarfUnit.cpp - Dwarf Type and Compile Units ---------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file contains support for constructing a dwarf compile unit.
12 //===----------------------------------------------------------------------===//
14 #include "DwarfUnit.h"
15 #include "DwarfAccelTable.h"
16 #include "DwarfCompileUnit.h"
17 #include "DwarfDebug.h"
18 #include "DwarfExpression.h"
19 #include "llvm/ADT/APFloat.h"
20 #include "llvm/CodeGen/MachineFunction.h"
21 #include "llvm/IR/Constants.h"
22 #include "llvm/IR/DIBuilder.h"
23 #include "llvm/IR/DataLayout.h"
24 #include "llvm/IR/GlobalVariable.h"
25 #include "llvm/IR/Instructions.h"
26 #include "llvm/IR/Mangler.h"
27 #include "llvm/MC/MCAsmInfo.h"
28 #include "llvm/MC/MCContext.h"
29 #include "llvm/MC/MCSection.h"
30 #include "llvm/MC/MCStreamer.h"
31 #include "llvm/Support/CommandLine.h"
32 #include "llvm/Target/TargetFrameLowering.h"
33 #include "llvm/Target/TargetLoweringObjectFile.h"
34 #include "llvm/Target/TargetMachine.h"
35 #include "llvm/Target/TargetRegisterInfo.h"
36 #include "llvm/Target/TargetSubtargetInfo.h"
40 #define DEBUG_TYPE "dwarfdebug"
43 GenerateDwarfTypeUnits("generate-type-units", cl::Hidden,
44 cl::desc("Generate DWARF4 type units."),
47 DIEDwarfExpression::DIEDwarfExpression(const AsmPrinter &AP, DwarfUnit &DU,
49 : DwarfExpression(AP.getDwarfDebug()->getDwarfVersion()), AP(AP), DU(DU),
52 void DIEDwarfExpression::EmitOp(uint8_t Op, const char* Comment) {
53 DU.addUInt(DIE, dwarf::DW_FORM_data1, Op);
55 void DIEDwarfExpression::EmitSigned(int64_t Value) {
56 DU.addSInt(DIE, dwarf::DW_FORM_sdata, Value);
58 void DIEDwarfExpression::EmitUnsigned(uint64_t Value) {
59 DU.addUInt(DIE, dwarf::DW_FORM_udata, Value);
61 bool DIEDwarfExpression::isFrameRegister(const TargetRegisterInfo &TRI,
62 unsigned MachineReg) {
63 return MachineReg == TRI.getFrameRegister(*AP.MF);
66 DwarfUnit::DwarfUnit(dwarf::Tag UnitTag, const DICompileUnit *Node,
67 AsmPrinter *A, DwarfDebug *DW, DwarfFile *DWU)
68 : CUNode(Node), UnitDie(*DIE::get(DIEValueAllocator, UnitTag)), Asm(A),
69 DD(DW), DU(DWU), IndexTyDie(nullptr), Section(nullptr) {
70 assert(UnitTag == dwarf::DW_TAG_compile_unit ||
71 UnitTag == dwarf::DW_TAG_type_unit);
74 DwarfTypeUnit::DwarfTypeUnit(DwarfCompileUnit &CU, AsmPrinter *A,
75 DwarfDebug *DW, DwarfFile *DWU,
76 MCDwarfDwoLineTable *SplitLineTable)
77 : DwarfUnit(dwarf::DW_TAG_type_unit, CU.getCUNode(), A, DW, DWU), CU(CU),
78 SplitLineTable(SplitLineTable) {
80 addSectionOffset(UnitDie, dwarf::DW_AT_stmt_list, 0);
83 DwarfUnit::~DwarfUnit() {
84 for (unsigned j = 0, M = DIEBlocks.size(); j < M; ++j)
85 DIEBlocks[j]->~DIEBlock();
86 for (unsigned j = 0, M = DIELocs.size(); j < M; ++j)
87 DIELocs[j]->~DIELoc();
90 int64_t DwarfUnit::getDefaultLowerBound() const {
91 switch (getLanguage()) {
95 case dwarf::DW_LANG_C89:
96 case dwarf::DW_LANG_C99:
97 case dwarf::DW_LANG_C:
98 case dwarf::DW_LANG_C_plus_plus:
99 case dwarf::DW_LANG_ObjC:
100 case dwarf::DW_LANG_ObjC_plus_plus:
103 case dwarf::DW_LANG_Fortran77:
104 case dwarf::DW_LANG_Fortran90:
105 case dwarf::DW_LANG_Fortran95:
108 // The languages below have valid values only if the DWARF version >= 4.
109 case dwarf::DW_LANG_Java:
110 case dwarf::DW_LANG_Python:
111 case dwarf::DW_LANG_UPC:
112 case dwarf::DW_LANG_D:
113 if (dwarf::DWARF_VERSION >= 4)
117 case dwarf::DW_LANG_Ada83:
118 case dwarf::DW_LANG_Ada95:
119 case dwarf::DW_LANG_Cobol74:
120 case dwarf::DW_LANG_Cobol85:
121 case dwarf::DW_LANG_Modula2:
122 case dwarf::DW_LANG_Pascal83:
123 case dwarf::DW_LANG_PLI:
124 if (dwarf::DWARF_VERSION >= 4)
128 // The languages below have valid values only if the DWARF version >= 5.
129 case dwarf::DW_LANG_OpenCL:
130 case dwarf::DW_LANG_Go:
131 case dwarf::DW_LANG_Haskell:
132 case dwarf::DW_LANG_C_plus_plus_03:
133 case dwarf::DW_LANG_C_plus_plus_11:
134 case dwarf::DW_LANG_OCaml:
135 case dwarf::DW_LANG_Rust:
136 case dwarf::DW_LANG_C11:
137 case dwarf::DW_LANG_Swift:
138 case dwarf::DW_LANG_Dylan:
139 case dwarf::DW_LANG_C_plus_plus_14:
140 if (dwarf::DWARF_VERSION >= 5)
144 case dwarf::DW_LANG_Modula3:
145 case dwarf::DW_LANG_Julia:
146 case dwarf::DW_LANG_Fortran03:
147 case dwarf::DW_LANG_Fortran08:
148 if (dwarf::DWARF_VERSION >= 5)
156 /// Check whether the DIE for this MDNode can be shared across CUs.
157 static bool isShareableAcrossCUs(const DINode *D) {
158 // When the MDNode can be part of the type system, the DIE can be shared
160 // Combining type units and cross-CU DIE sharing is lower value (since
161 // cross-CU DIE sharing is used in LTO and removes type redundancy at that
162 // level already) but may be implementable for some value in projects
163 // building multiple independent libraries with LTO and then linking those
165 return (isa<DIType>(D) ||
166 (isa<DISubprogram>(D) && !cast<DISubprogram>(D)->isDefinition())) &&
167 !GenerateDwarfTypeUnits;
170 DIE *DwarfUnit::getDIE(const DINode *D) const {
171 if (isShareableAcrossCUs(D))
172 return DU->getDIE(D);
173 return MDNodeToDieMap.lookup(D);
176 void DwarfUnit::insertDIE(const DINode *Desc, DIE *D) {
177 if (isShareableAcrossCUs(Desc)) {
178 DU->insertDIE(Desc, D);
181 MDNodeToDieMap.insert(std::make_pair(Desc, D));
184 void DwarfUnit::addFlag(DIE &Die, dwarf::Attribute Attribute) {
185 if (DD->getDwarfVersion() >= 4)
186 Die.addValue(DIEValueAllocator, Attribute, dwarf::DW_FORM_flag_present,
189 Die.addValue(DIEValueAllocator, Attribute, dwarf::DW_FORM_flag,
193 void DwarfUnit::addUInt(DIEValueList &Die, dwarf::Attribute Attribute,
194 Optional<dwarf::Form> Form, uint64_t Integer) {
196 Form = DIEInteger::BestForm(false, Integer);
197 Die.addValue(DIEValueAllocator, Attribute, *Form, DIEInteger(Integer));
200 void DwarfUnit::addUInt(DIEValueList &Block, dwarf::Form Form,
202 addUInt(Block, (dwarf::Attribute)0, Form, Integer);
205 void DwarfUnit::addSInt(DIEValueList &Die, dwarf::Attribute Attribute,
206 Optional<dwarf::Form> Form, int64_t Integer) {
208 Form = DIEInteger::BestForm(true, Integer);
209 Die.addValue(DIEValueAllocator, Attribute, *Form, DIEInteger(Integer));
212 void DwarfUnit::addSInt(DIELoc &Die, Optional<dwarf::Form> Form,
214 addSInt(Die, (dwarf::Attribute)0, Form, Integer);
217 void DwarfUnit::addString(DIE &Die, dwarf::Attribute Attribute,
219 Die.addValue(DIEValueAllocator, Attribute,
220 isDwoUnit() ? dwarf::DW_FORM_GNU_str_index : dwarf::DW_FORM_strp,
221 DIEString(DU->getStringPool().getEntry(*Asm, String)));
224 DIEValueList::value_iterator DwarfUnit::addLabel(DIEValueList &Die,
225 dwarf::Attribute Attribute,
227 const MCSymbol *Label) {
228 return Die.addValue(DIEValueAllocator, Attribute, Form, DIELabel(Label));
231 void DwarfUnit::addLabel(DIELoc &Die, dwarf::Form Form, const MCSymbol *Label) {
232 addLabel(Die, (dwarf::Attribute)0, Form, Label);
235 void DwarfUnit::addSectionOffset(DIE &Die, dwarf::Attribute Attribute,
237 if (DD->getDwarfVersion() >= 4)
238 addUInt(Die, Attribute, dwarf::DW_FORM_sec_offset, Integer);
240 addUInt(Die, Attribute, dwarf::DW_FORM_data4, Integer);
243 unsigned DwarfTypeUnit::getOrCreateSourceID(StringRef FileName, StringRef DirName) {
244 return SplitLineTable ? SplitLineTable->getFile(DirName, FileName)
245 : getCU().getOrCreateSourceID(FileName, DirName);
248 void DwarfUnit::addOpAddress(DIELoc &Die, const MCSymbol *Sym) {
249 if (!DD->useSplitDwarf()) {
250 addUInt(Die, dwarf::DW_FORM_data1, dwarf::DW_OP_addr);
251 addLabel(Die, dwarf::DW_FORM_udata, Sym);
253 addUInt(Die, dwarf::DW_FORM_data1, dwarf::DW_OP_GNU_addr_index);
254 addUInt(Die, dwarf::DW_FORM_GNU_addr_index,
255 DD->getAddressPool().getIndex(Sym));
259 void DwarfUnit::addLabelDelta(DIE &Die, dwarf::Attribute Attribute,
260 const MCSymbol *Hi, const MCSymbol *Lo) {
261 Die.addValue(DIEValueAllocator, Attribute, dwarf::DW_FORM_data4,
262 new (DIEValueAllocator) DIEDelta(Hi, Lo));
265 void DwarfUnit::addDIEEntry(DIE &Die, dwarf::Attribute Attribute, DIE &Entry) {
266 addDIEEntry(Die, Attribute, DIEEntry(Entry));
269 void DwarfUnit::addDIETypeSignature(DIE &Die, uint64_t Signature) {
270 // Flag the type unit reference as a declaration so that if it contains
271 // members (implicit special members, static data member definitions, member
272 // declarations for definitions in this CU, etc) consumers don't get confused
273 // and think this is a full definition.
274 addFlag(Die, dwarf::DW_AT_declaration);
276 Die.addValue(DIEValueAllocator, dwarf::DW_AT_signature,
277 dwarf::DW_FORM_ref_sig8, DIEInteger(Signature));
280 void DwarfUnit::addDIETypeSignature(DIE &Die, dwarf::Attribute Attribute,
281 StringRef Identifier) {
282 uint64_t Signature = DD->makeTypeSignature(Identifier);
283 Die.addValue(DIEValueAllocator, Attribute, dwarf::DW_FORM_ref_sig8,
284 DIEInteger(Signature));
287 void DwarfUnit::addDIEEntry(DIE &Die, dwarf::Attribute Attribute,
289 const DIE *DieCU = Die.getUnitOrNull();
290 const DIE *EntryCU = Entry.getEntry().getUnitOrNull();
292 // We assume that Die belongs to this CU, if it is not linked to any CU yet.
293 DieCU = &getUnitDie();
295 EntryCU = &getUnitDie();
296 Die.addValue(DIEValueAllocator, Attribute,
297 EntryCU == DieCU ? dwarf::DW_FORM_ref4 : dwarf::DW_FORM_ref_addr,
301 DIE &DwarfUnit::createAndAddDIE(unsigned Tag, DIE &Parent, const DINode *N) {
302 DIE &Die = Parent.addChild(DIE::get(DIEValueAllocator, (dwarf::Tag)Tag));
308 void DwarfUnit::addBlock(DIE &Die, dwarf::Attribute Attribute, DIELoc *Loc) {
309 Loc->ComputeSize(Asm);
310 DIELocs.push_back(Loc); // Memoize so we can call the destructor later on.
311 Die.addValue(DIEValueAllocator, Attribute,
312 Loc->BestForm(DD->getDwarfVersion()), Loc);
315 void DwarfUnit::addBlock(DIE &Die, dwarf::Attribute Attribute,
317 Block->ComputeSize(Asm);
318 DIEBlocks.push_back(Block); // Memoize so we can call the destructor later on.
319 Die.addValue(DIEValueAllocator, Attribute, Block->BestForm(), Block);
322 void DwarfUnit::addSourceLine(DIE &Die, unsigned Line, StringRef File,
323 StringRef Directory) {
327 unsigned FileID = getOrCreateSourceID(File, Directory);
328 assert(FileID && "Invalid file id");
329 addUInt(Die, dwarf::DW_AT_decl_file, None, FileID);
330 addUInt(Die, dwarf::DW_AT_decl_line, None, Line);
333 void DwarfUnit::addSourceLine(DIE &Die, const DILocalVariable *V) {
336 addSourceLine(Die, V->getLine(), V->getScope()->getFilename(),
337 V->getScope()->getDirectory());
340 void DwarfUnit::addSourceLine(DIE &Die, const DIGlobalVariable *G) {
343 addSourceLine(Die, G->getLine(), G->getFilename(), G->getDirectory());
346 void DwarfUnit::addSourceLine(DIE &Die, const DISubprogram *SP) {
349 addSourceLine(Die, SP->getLine(), SP->getFilename(), SP->getDirectory());
352 void DwarfUnit::addSourceLine(DIE &Die, const DIType *Ty) {
355 addSourceLine(Die, Ty->getLine(), Ty->getFilename(), Ty->getDirectory());
358 void DwarfUnit::addSourceLine(DIE &Die, const DIObjCProperty *Ty) {
361 addSourceLine(Die, Ty->getLine(), Ty->getFilename(), Ty->getDirectory());
364 void DwarfUnit::addSourceLine(DIE &Die, const DINamespace *NS) {
365 addSourceLine(Die, NS->getLine(), NS->getFilename(), NS->getDirectory());
368 bool DwarfUnit::addRegisterOpPiece(DIELoc &TheDie, unsigned Reg,
369 unsigned SizeInBits, unsigned OffsetInBits) {
370 DIEDwarfExpression Expr(*Asm, *this, TheDie);
371 Expr.AddMachineRegPiece(*Asm->MF->getSubtarget().getRegisterInfo(), Reg,
372 SizeInBits, OffsetInBits);
376 bool DwarfUnit::addRegisterOffset(DIELoc &TheDie, unsigned Reg,
378 DIEDwarfExpression Expr(*Asm, *this, TheDie);
379 return Expr.AddMachineRegIndirect(*Asm->MF->getSubtarget().getRegisterInfo(),
383 /* Byref variables, in Blocks, are declared by the programmer as "SomeType
384 VarName;", but the compiler creates a __Block_byref_x_VarName struct, and
385 gives the variable VarName either the struct, or a pointer to the struct, as
386 its type. This is necessary for various behind-the-scenes things the
387 compiler needs to do with by-reference variables in Blocks.
389 However, as far as the original *programmer* is concerned, the variable
390 should still have type 'SomeType', as originally declared.
392 The function getBlockByrefType dives into the __Block_byref_x_VarName
393 struct to find the original type of the variable, which is then assigned to
394 the variable's Debug Information Entry as its real type. So far, so good.
395 However now the debugger will expect the variable VarName to have the type
396 SomeType. So we need the location attribute for the variable to be an
397 expression that explains to the debugger how to navigate through the
398 pointers and struct to find the actual variable of type SomeType.
400 The following function does just that. We start by getting
401 the "normal" location for the variable. This will be the location
402 of either the struct __Block_byref_x_VarName or the pointer to the
403 struct __Block_byref_x_VarName.
405 The struct will look something like:
407 struct __Block_byref_x_VarName {
409 struct __Block_byref_x_VarName *forwarding;
410 ... <various other fields>
412 ... <maybe more fields>
415 If we are given the struct directly (as our starting point) we
416 need to tell the debugger to:
418 1). Add the offset of the forwarding field.
420 2). Follow that pointer to get the real __Block_byref_x_VarName
421 struct to use (the real one may have been copied onto the heap).
423 3). Add the offset for the field VarName, to find the actual variable.
425 If we started with a pointer to the struct, then we need to
426 dereference that pointer first, before the other steps.
427 Translating this into DWARF ops, we will need to append the following
428 to the current location description for the variable:
430 DW_OP_deref -- optional, if we start with a pointer
431 DW_OP_plus_uconst <forward_fld_offset>
433 DW_OP_plus_uconst <varName_fld_offset>
435 That is what this function does. */
437 void DwarfUnit::addBlockByrefAddress(const DbgVariable &DV, DIE &Die,
438 dwarf::Attribute Attribute,
439 const MachineLocation &Location) {
440 const DIType *Ty = DV.getType();
441 const DIType *TmpTy = Ty;
442 uint16_t Tag = Ty->getTag();
443 bool isPointer = false;
445 StringRef varName = DV.getName();
447 if (Tag == dwarf::DW_TAG_pointer_type) {
448 auto *DTy = cast<DIDerivedType>(Ty);
449 TmpTy = resolve(DTy->getBaseType());
453 // Find the __forwarding field and the variable field in the __Block_byref
455 DINodeArray Fields = cast<DICompositeType>(TmpTy)->getElements();
456 const DIDerivedType *varField = nullptr;
457 const DIDerivedType *forwardingField = nullptr;
459 for (unsigned i = 0, N = Fields.size(); i < N; ++i) {
460 auto *DT = cast<DIDerivedType>(Fields[i]);
461 StringRef fieldName = DT->getName();
462 if (fieldName == "__forwarding")
463 forwardingField = DT;
464 else if (fieldName == varName)
468 // Get the offsets for the forwarding field and the variable field.
469 unsigned forwardingFieldOffset = forwardingField->getOffsetInBits() >> 3;
470 unsigned varFieldOffset = varField->getOffsetInBits() >> 2;
472 // Decode the original location, and use that as the start of the byref
473 // variable's location.
474 DIELoc *Loc = new (DIEValueAllocator) DIELoc;
477 if (Location.isReg())
478 validReg = addRegisterOpPiece(*Loc, Location.getReg());
480 validReg = addRegisterOffset(*Loc, Location.getReg(), Location.getOffset());
485 // If we started with a pointer to the __Block_byref... struct, then
486 // the first thing we need to do is dereference the pointer (DW_OP_deref).
488 addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_deref);
490 // Next add the offset for the '__forwarding' field:
491 // DW_OP_plus_uconst ForwardingFieldOffset. Note there's no point in
492 // adding the offset if it's 0.
493 if (forwardingFieldOffset > 0) {
494 addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_plus_uconst);
495 addUInt(*Loc, dwarf::DW_FORM_udata, forwardingFieldOffset);
498 // Now dereference the __forwarding field to get to the real __Block_byref
499 // struct: DW_OP_deref.
500 addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_deref);
502 // Now that we've got the real __Block_byref... struct, add the offset
503 // for the variable's field to get to the location of the actual variable:
504 // DW_OP_plus_uconst varFieldOffset. Again, don't add if it's 0.
505 if (varFieldOffset > 0) {
506 addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_plus_uconst);
507 addUInt(*Loc, dwarf::DW_FORM_udata, varFieldOffset);
510 // Now attach the location information to the DIE.
511 addBlock(Die, Attribute, Loc);
514 /// Return true if type encoding is unsigned.
515 static bool isUnsignedDIType(DwarfDebug *DD, const DIType *Ty) {
516 if (auto *CTy = dyn_cast<DICompositeType>(Ty)) {
517 // FIXME: Enums without a fixed underlying type have unknown signedness
518 // here, leading to incorrectly emitted constants.
519 if (CTy->getTag() == dwarf::DW_TAG_enumeration_type)
522 // (Pieces of) aggregate types that get hacked apart by SROA may be
523 // represented by a constant. Encode them as unsigned bytes.
527 if (auto *DTy = dyn_cast<DIDerivedType>(Ty)) {
528 dwarf::Tag T = (dwarf::Tag)Ty->getTag();
529 // Encode pointer constants as unsigned bytes. This is used at least for
530 // null pointer constant emission.
531 // FIXME: reference and rvalue_reference /probably/ shouldn't be allowed
532 // here, but accept them for now due to a bug in SROA producing bogus
534 if (T == dwarf::DW_TAG_pointer_type ||
535 T == dwarf::DW_TAG_ptr_to_member_type ||
536 T == dwarf::DW_TAG_reference_type ||
537 T == dwarf::DW_TAG_rvalue_reference_type)
539 assert(T == dwarf::DW_TAG_typedef || T == dwarf::DW_TAG_const_type ||
540 T == dwarf::DW_TAG_volatile_type ||
541 T == dwarf::DW_TAG_restrict_type);
542 DITypeRef Deriv = DTy->getBaseType();
543 assert(Deriv && "Expected valid base type");
544 return isUnsignedDIType(DD, DD->resolve(Deriv));
547 auto *BTy = cast<DIBasicType>(Ty);
548 unsigned Encoding = BTy->getEncoding();
549 assert((Encoding == dwarf::DW_ATE_unsigned ||
550 Encoding == dwarf::DW_ATE_unsigned_char ||
551 Encoding == dwarf::DW_ATE_signed ||
552 Encoding == dwarf::DW_ATE_signed_char ||
553 Encoding == dwarf::DW_ATE_float || Encoding == dwarf::DW_ATE_UTF ||
554 Encoding == dwarf::DW_ATE_boolean ||
555 (Ty->getTag() == dwarf::DW_TAG_unspecified_type &&
556 Ty->getName() == "decltype(nullptr)")) &&
557 "Unsupported encoding");
558 return Encoding == dwarf::DW_ATE_unsigned ||
559 Encoding == dwarf::DW_ATE_unsigned_char ||
560 Encoding == dwarf::DW_ATE_UTF || Encoding == dwarf::DW_ATE_boolean ||
561 Ty->getTag() == dwarf::DW_TAG_unspecified_type;
564 void DwarfUnit::addConstantFPValue(DIE &Die, const MachineOperand &MO) {
565 assert(MO.isFPImm() && "Invalid machine operand!");
566 DIEBlock *Block = new (DIEValueAllocator) DIEBlock;
567 APFloat FPImm = MO.getFPImm()->getValueAPF();
569 // Get the raw data form of the floating point.
570 const APInt FltVal = FPImm.bitcastToAPInt();
571 const char *FltPtr = (const char *)FltVal.getRawData();
573 int NumBytes = FltVal.getBitWidth() / 8; // 8 bits per byte.
574 bool LittleEndian = Asm->getDataLayout().isLittleEndian();
575 int Incr = (LittleEndian ? 1 : -1);
576 int Start = (LittleEndian ? 0 : NumBytes - 1);
577 int Stop = (LittleEndian ? NumBytes : -1);
579 // Output the constant to DWARF one byte at a time.
580 for (; Start != Stop; Start += Incr)
581 addUInt(*Block, dwarf::DW_FORM_data1, (unsigned char)0xFF & FltPtr[Start]);
583 addBlock(Die, dwarf::DW_AT_const_value, Block);
586 void DwarfUnit::addConstantFPValue(DIE &Die, const ConstantFP *CFP) {
587 // Pass this down to addConstantValue as an unsigned bag of bits.
588 addConstantValue(Die, CFP->getValueAPF().bitcastToAPInt(), true);
591 void DwarfUnit::addConstantValue(DIE &Die, const ConstantInt *CI,
593 addConstantValue(Die, CI->getValue(), Ty);
596 void DwarfUnit::addConstantValue(DIE &Die, const MachineOperand &MO,
598 assert(MO.isImm() && "Invalid machine operand!");
600 addConstantValue(Die, isUnsignedDIType(DD, Ty), MO.getImm());
603 void DwarfUnit::addConstantValue(DIE &Die, bool Unsigned, uint64_t Val) {
604 // FIXME: This is a bit conservative/simple - it emits negative values always
605 // sign extended to 64 bits rather than minimizing the number of bytes.
606 addUInt(Die, dwarf::DW_AT_const_value,
607 Unsigned ? dwarf::DW_FORM_udata : dwarf::DW_FORM_sdata, Val);
610 void DwarfUnit::addConstantValue(DIE &Die, const APInt &Val, const DIType *Ty) {
611 addConstantValue(Die, Val, isUnsignedDIType(DD, Ty));
614 void DwarfUnit::addConstantValue(DIE &Die, const APInt &Val, bool Unsigned) {
615 unsigned CIBitWidth = Val.getBitWidth();
616 if (CIBitWidth <= 64) {
617 addConstantValue(Die, Unsigned,
618 Unsigned ? Val.getZExtValue() : Val.getSExtValue());
622 DIEBlock *Block = new (DIEValueAllocator) DIEBlock;
624 // Get the raw data form of the large APInt.
625 const uint64_t *Ptr64 = Val.getRawData();
627 int NumBytes = Val.getBitWidth() / 8; // 8 bits per byte.
628 bool LittleEndian = Asm->getDataLayout().isLittleEndian();
630 // Output the constant to DWARF one byte at a time.
631 for (int i = 0; i < NumBytes; i++) {
634 c = Ptr64[i / 8] >> (8 * (i & 7));
636 c = Ptr64[(NumBytes - 1 - i) / 8] >> (8 * ((NumBytes - 1 - i) & 7));
637 addUInt(*Block, dwarf::DW_FORM_data1, c);
640 addBlock(Die, dwarf::DW_AT_const_value, Block);
643 void DwarfUnit::addLinkageName(DIE &Die, StringRef LinkageName) {
644 if (!LinkageName.empty())
646 DD->getDwarfVersion() >= 4 ? dwarf::DW_AT_linkage_name
647 : dwarf::DW_AT_MIPS_linkage_name,
648 GlobalValue::getRealLinkageName(LinkageName));
651 void DwarfUnit::addTemplateParams(DIE &Buffer, DINodeArray TParams) {
652 // Add template parameters.
653 for (const auto *Element : TParams) {
654 if (auto *TTP = dyn_cast<DITemplateTypeParameter>(Element))
655 constructTemplateTypeParameterDIE(Buffer, TTP);
656 else if (auto *TVP = dyn_cast<DITemplateValueParameter>(Element))
657 constructTemplateValueParameterDIE(Buffer, TVP);
661 DIE *DwarfUnit::getOrCreateContextDIE(const DIScope *Context) {
662 if (!Context || isa<DIFile>(Context))
663 return &getUnitDie();
664 if (auto *T = dyn_cast<DIType>(Context))
665 return getOrCreateTypeDIE(T);
666 if (auto *NS = dyn_cast<DINamespace>(Context))
667 return getOrCreateNameSpace(NS);
668 if (auto *SP = dyn_cast<DISubprogram>(Context))
669 return getOrCreateSubprogramDIE(SP);
670 if (auto *M = dyn_cast<DIModule>(Context))
671 return getOrCreateModule(M);
672 return getDIE(Context);
675 DIE *DwarfUnit::createTypeDIE(const DICompositeType *Ty) {
676 auto *Context = resolve(Ty->getScope());
677 DIE *ContextDIE = getOrCreateContextDIE(Context);
679 if (DIE *TyDIE = getDIE(Ty))
683 DIE &TyDIE = createAndAddDIE(Ty->getTag(), *ContextDIE, Ty);
685 constructTypeDIE(TyDIE, cast<DICompositeType>(Ty));
687 if (!Ty->isExternalTypeRef())
688 updateAcceleratorTables(Context, Ty, TyDIE);
692 DIE *DwarfUnit::getOrCreateTypeDIE(const MDNode *TyNode) {
696 auto *Ty = cast<DIType>(TyNode);
698 // DW_TAG_restrict_type is not supported in DWARF2
699 if (Ty->getTag() == dwarf::DW_TAG_restrict_type && DD->getDwarfVersion() <= 2)
700 return getOrCreateTypeDIE(resolve(cast<DIDerivedType>(Ty)->getBaseType()));
702 // Construct the context before querying for the existence of the DIE in case
703 // such construction creates the DIE.
704 auto *Context = resolve(Ty->getScope());
705 DIE *ContextDIE = getOrCreateContextDIE(Context);
708 if (DIE *TyDIE = getDIE(Ty))
712 DIE &TyDIE = createAndAddDIE(Ty->getTag(), *ContextDIE, Ty);
714 updateAcceleratorTables(Context, Ty, TyDIE);
716 if (auto *BT = dyn_cast<DIBasicType>(Ty))
717 constructTypeDIE(TyDIE, BT);
718 else if (auto *STy = dyn_cast<DISubroutineType>(Ty))
719 constructTypeDIE(TyDIE, STy);
720 else if (auto *CTy = dyn_cast<DICompositeType>(Ty)) {
721 if (GenerateDwarfTypeUnits && !Ty->isForwardDecl())
722 if (MDString *TypeId = CTy->getRawIdentifier()) {
723 DD->addDwarfTypeUnitType(getCU(), TypeId->getString(), TyDIE, CTy);
724 // Skip updating the accelerator tables since this is not the full type.
727 constructTypeDIE(TyDIE, CTy);
729 constructTypeDIE(TyDIE, cast<DIDerivedType>(Ty));
735 void DwarfUnit::updateAcceleratorTables(const DIScope *Context,
736 const DIType *Ty, const DIE &TyDIE) {
737 if (!Ty->getName().empty() && !Ty->isForwardDecl()) {
738 bool IsImplementation = 0;
739 if (auto *CT = dyn_cast<DICompositeType>(Ty)) {
740 // A runtime language of 0 actually means C/C++ and that any
741 // non-negative value is some version of Objective-C/C++.
742 IsImplementation = CT->getRuntimeLang() == 0 || CT->isObjcClassComplete();
744 unsigned Flags = IsImplementation ? dwarf::DW_FLAG_type_implementation : 0;
745 DD->addAccelType(Ty->getName(), TyDIE, Flags);
747 if (!Context || isa<DICompileUnit>(Context) || isa<DIFile>(Context) ||
748 isa<DINamespace>(Context))
749 addGlobalType(Ty, TyDIE, Context);
753 void DwarfUnit::addType(DIE &Entity, const DIType *Ty,
754 dwarf::Attribute Attribute) {
755 assert(Ty && "Trying to add a type that doesn't exist?");
756 addDIEEntry(Entity, Attribute, DIEEntry(*getOrCreateTypeDIE(Ty)));
759 std::string DwarfUnit::getParentContextString(const DIScope *Context) const {
763 // FIXME: Decide whether to implement this for non-C++ languages.
764 if (getLanguage() != dwarf::DW_LANG_C_plus_plus)
768 SmallVector<const DIScope *, 1> Parents;
769 while (!isa<DICompileUnit>(Context)) {
770 Parents.push_back(Context);
771 if (Context->getScope())
772 Context = resolve(Context->getScope());
774 // Structure, etc types will have a NULL context if they're at the top
779 // Reverse iterate over our list to go from the outermost construct to the
781 for (const DIScope *Ctx : make_range(Parents.rbegin(), Parents.rend())) {
782 StringRef Name = Ctx->getName();
783 if (Name.empty() && isa<DINamespace>(Ctx))
784 Name = "(anonymous namespace)";
793 void DwarfUnit::constructTypeDIE(DIE &Buffer, const DIBasicType *BTy) {
794 // Get core information.
795 StringRef Name = BTy->getName();
796 // Add name if not anonymous or intermediate type.
798 addString(Buffer, dwarf::DW_AT_name, Name);
800 // An unspecified type only has a name attribute.
801 if (BTy->getTag() == dwarf::DW_TAG_unspecified_type)
804 addUInt(Buffer, dwarf::DW_AT_encoding, dwarf::DW_FORM_data1,
807 uint64_t Size = BTy->getSizeInBits() >> 3;
808 addUInt(Buffer, dwarf::DW_AT_byte_size, None, Size);
811 void DwarfUnit::constructTypeDIE(DIE &Buffer, const DIDerivedType *DTy) {
812 // Get core information.
813 StringRef Name = DTy->getName();
814 uint64_t Size = DTy->getSizeInBits() >> 3;
815 uint16_t Tag = Buffer.getTag();
817 // Map to main type, void will not have a type.
818 const DIType *FromTy = resolve(DTy->getBaseType());
820 addType(Buffer, FromTy);
822 // Add name if not anonymous or intermediate type.
824 addString(Buffer, dwarf::DW_AT_name, Name);
826 // Add size if non-zero (derived types might be zero-sized.)
827 if (Size && Tag != dwarf::DW_TAG_pointer_type
828 && Tag != dwarf::DW_TAG_ptr_to_member_type
829 && Tag != dwarf::DW_TAG_reference_type
830 && Tag != dwarf::DW_TAG_rvalue_reference_type)
831 addUInt(Buffer, dwarf::DW_AT_byte_size, None, Size);
833 if (Tag == dwarf::DW_TAG_ptr_to_member_type)
835 Buffer, dwarf::DW_AT_containing_type,
836 *getOrCreateTypeDIE(resolve(cast<DIDerivedType>(DTy)->getClassType())));
837 // Add source line info if available and TyDesc is not a forward declaration.
838 if (!DTy->isForwardDecl())
839 addSourceLine(Buffer, DTy);
842 void DwarfUnit::constructSubprogramArguments(DIE &Buffer, DITypeRefArray Args) {
843 for (unsigned i = 1, N = Args.size(); i < N; ++i) {
844 const DIType *Ty = resolve(Args[i]);
846 assert(i == N-1 && "Unspecified parameter must be the last argument");
847 createAndAddDIE(dwarf::DW_TAG_unspecified_parameters, Buffer);
849 DIE &Arg = createAndAddDIE(dwarf::DW_TAG_formal_parameter, Buffer);
851 if (Ty->isArtificial())
852 addFlag(Arg, dwarf::DW_AT_artificial);
857 void DwarfUnit::constructTypeDIE(DIE &Buffer, const DISubroutineType *CTy) {
858 // Add return type. A void return won't have a type.
859 auto Elements = cast<DISubroutineType>(CTy)->getTypeArray();
861 if (auto RTy = resolve(Elements[0]))
862 addType(Buffer, RTy);
864 bool isPrototyped = true;
865 if (Elements.size() == 2 && !Elements[1])
866 isPrototyped = false;
868 constructSubprogramArguments(Buffer, Elements);
870 // Add prototype flag if we're dealing with a C language and the function has
872 uint16_t Language = getLanguage();
874 (Language == dwarf::DW_LANG_C89 || Language == dwarf::DW_LANG_C99 ||
875 Language == dwarf::DW_LANG_ObjC))
876 addFlag(Buffer, dwarf::DW_AT_prototyped);
878 // Add a DW_AT_calling_convention if this has an explicit convention.
879 if (CTy->getCC() && CTy->getCC() != dwarf::DW_CC_normal)
880 addUInt(Buffer, dwarf::DW_AT_calling_convention, dwarf::DW_FORM_data1,
883 if (CTy->isLValueReference())
884 addFlag(Buffer, dwarf::DW_AT_reference);
886 if (CTy->isRValueReference())
887 addFlag(Buffer, dwarf::DW_AT_rvalue_reference);
890 void DwarfUnit::constructTypeDIE(DIE &Buffer, const DICompositeType *CTy) {
891 if (CTy->isExternalTypeRef()) {
892 StringRef Identifier = CTy->getIdentifier();
893 assert(!Identifier.empty() && "external type ref without identifier");
894 addFlag(Buffer, dwarf::DW_AT_declaration);
895 return addDIETypeSignature(Buffer, dwarf::DW_AT_signature, Identifier);
898 // Add name if not anonymous or intermediate type.
899 StringRef Name = CTy->getName();
901 uint64_t Size = CTy->getSizeInBits() >> 3;
902 uint16_t Tag = Buffer.getTag();
905 case dwarf::DW_TAG_array_type:
906 constructArrayTypeDIE(Buffer, CTy);
908 case dwarf::DW_TAG_enumeration_type:
909 constructEnumTypeDIE(Buffer, CTy);
911 case dwarf::DW_TAG_structure_type:
912 case dwarf::DW_TAG_union_type:
913 case dwarf::DW_TAG_class_type: {
914 // Add elements to structure type.
915 DINodeArray Elements = CTy->getElements();
916 for (const auto *Element : Elements) {
919 if (auto *SP = dyn_cast<DISubprogram>(Element))
920 getOrCreateSubprogramDIE(SP);
921 else if (auto *DDTy = dyn_cast<DIDerivedType>(Element)) {
922 if (DDTy->getTag() == dwarf::DW_TAG_friend) {
923 DIE &ElemDie = createAndAddDIE(dwarf::DW_TAG_friend, Buffer);
924 addType(ElemDie, resolve(DDTy->getBaseType()), dwarf::DW_AT_friend);
925 } else if (DDTy->isStaticMember()) {
926 getOrCreateStaticMemberDIE(DDTy);
928 constructMemberDIE(Buffer, DDTy);
930 } else if (auto *Property = dyn_cast<DIObjCProperty>(Element)) {
931 DIE &ElemDie = createAndAddDIE(Property->getTag(), Buffer);
932 StringRef PropertyName = Property->getName();
933 addString(ElemDie, dwarf::DW_AT_APPLE_property_name, PropertyName);
934 if (Property->getType())
935 addType(ElemDie, resolve(Property->getType()));
936 addSourceLine(ElemDie, Property);
937 StringRef GetterName = Property->getGetterName();
938 if (!GetterName.empty())
939 addString(ElemDie, dwarf::DW_AT_APPLE_property_getter, GetterName);
940 StringRef SetterName = Property->getSetterName();
941 if (!SetterName.empty())
942 addString(ElemDie, dwarf::DW_AT_APPLE_property_setter, SetterName);
943 if (unsigned PropertyAttributes = Property->getAttributes())
944 addUInt(ElemDie, dwarf::DW_AT_APPLE_property_attribute, None,
949 if (CTy->isAppleBlockExtension())
950 addFlag(Buffer, dwarf::DW_AT_APPLE_block);
952 // This is outside the DWARF spec, but GDB expects a DW_AT_containing_type
953 // inside C++ composite types to point to the base class with the vtable.
954 if (auto *ContainingType =
955 dyn_cast_or_null<DICompositeType>(resolve(CTy->getVTableHolder())))
956 addDIEEntry(Buffer, dwarf::DW_AT_containing_type,
957 *getOrCreateTypeDIE(ContainingType));
959 if (CTy->isObjcClassComplete())
960 addFlag(Buffer, dwarf::DW_AT_APPLE_objc_complete_type);
962 // Add template parameters to a class, structure or union types.
963 // FIXME: The support isn't in the metadata for this yet.
964 if (Tag == dwarf::DW_TAG_class_type ||
965 Tag == dwarf::DW_TAG_structure_type || Tag == dwarf::DW_TAG_union_type)
966 addTemplateParams(Buffer, CTy->getTemplateParams());
974 // Add name if not anonymous or intermediate type.
976 addString(Buffer, dwarf::DW_AT_name, Name);
978 if (Tag == dwarf::DW_TAG_enumeration_type ||
979 Tag == dwarf::DW_TAG_class_type || Tag == dwarf::DW_TAG_structure_type ||
980 Tag == dwarf::DW_TAG_union_type) {
981 // Add size if non-zero (derived types might be zero-sized.)
982 // TODO: Do we care about size for enum forward declarations?
984 addUInt(Buffer, dwarf::DW_AT_byte_size, None, Size);
985 else if (!CTy->isForwardDecl())
986 // Add zero size if it is not a forward declaration.
987 addUInt(Buffer, dwarf::DW_AT_byte_size, None, 0);
989 // If we're a forward decl, say so.
990 if (CTy->isForwardDecl())
991 addFlag(Buffer, dwarf::DW_AT_declaration);
993 // Add source line info if available.
994 if (!CTy->isForwardDecl())
995 addSourceLine(Buffer, CTy);
997 // No harm in adding the runtime language to the declaration.
998 unsigned RLang = CTy->getRuntimeLang();
1000 addUInt(Buffer, dwarf::DW_AT_APPLE_runtime_class, dwarf::DW_FORM_data1,
1005 void DwarfUnit::constructTemplateTypeParameterDIE(
1006 DIE &Buffer, const DITemplateTypeParameter *TP) {
1008 createAndAddDIE(dwarf::DW_TAG_template_type_parameter, Buffer);
1009 // Add the type if it exists, it could be void and therefore no type.
1011 addType(ParamDIE, resolve(TP->getType()));
1012 if (!TP->getName().empty())
1013 addString(ParamDIE, dwarf::DW_AT_name, TP->getName());
1016 void DwarfUnit::constructTemplateValueParameterDIE(
1017 DIE &Buffer, const DITemplateValueParameter *VP) {
1018 DIE &ParamDIE = createAndAddDIE(VP->getTag(), Buffer);
1020 // Add the type if there is one, template template and template parameter
1021 // packs will not have a type.
1022 if (VP->getTag() == dwarf::DW_TAG_template_value_parameter)
1023 addType(ParamDIE, resolve(VP->getType()));
1024 if (!VP->getName().empty())
1025 addString(ParamDIE, dwarf::DW_AT_name, VP->getName());
1026 if (Metadata *Val = VP->getValue()) {
1027 if (ConstantInt *CI = mdconst::dyn_extract<ConstantInt>(Val))
1028 addConstantValue(ParamDIE, CI, resolve(VP->getType()));
1029 else if (GlobalValue *GV = mdconst::dyn_extract<GlobalValue>(Val)) {
1030 // We cannot describe the location of dllimport'd entities: the
1031 // computation of their address requires loads from the IAT.
1032 if (!GV->hasDLLImportStorageClass()) {
1033 // For declaration non-type template parameters (such as global values
1035 DIELoc *Loc = new (DIEValueAllocator) DIELoc;
1036 addOpAddress(*Loc, Asm->getSymbol(GV));
1037 // Emit DW_OP_stack_value to use the address as the immediate value of
1038 // the parameter, rather than a pointer to it.
1039 addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_stack_value);
1040 addBlock(ParamDIE, dwarf::DW_AT_location, Loc);
1042 } else if (VP->getTag() == dwarf::DW_TAG_GNU_template_template_param) {
1043 assert(isa<MDString>(Val));
1044 addString(ParamDIE, dwarf::DW_AT_GNU_template_name,
1045 cast<MDString>(Val)->getString());
1046 } else if (VP->getTag() == dwarf::DW_TAG_GNU_template_parameter_pack) {
1047 addTemplateParams(ParamDIE, cast<MDTuple>(Val));
1052 DIE *DwarfUnit::getOrCreateNameSpace(const DINamespace *NS) {
1053 // Construct the context before querying for the existence of the DIE in case
1054 // such construction creates the DIE.
1055 DIE *ContextDIE = getOrCreateContextDIE(NS->getScope());
1057 if (DIE *NDie = getDIE(NS))
1059 DIE &NDie = createAndAddDIE(dwarf::DW_TAG_namespace, *ContextDIE, NS);
1061 StringRef Name = NS->getName();
1063 addString(NDie, dwarf::DW_AT_name, NS->getName());
1065 Name = "(anonymous namespace)";
1066 DD->addAccelNamespace(Name, NDie);
1067 addGlobalName(Name, NDie, NS->getScope());
1068 addSourceLine(NDie, NS);
1072 DIE *DwarfUnit::getOrCreateModule(const DIModule *M) {
1073 // Construct the context before querying for the existence of the DIE in case
1074 // such construction creates the DIE.
1075 DIE *ContextDIE = getOrCreateContextDIE(M->getScope());
1077 if (DIE *MDie = getDIE(M))
1079 DIE &MDie = createAndAddDIE(dwarf::DW_TAG_module, *ContextDIE, M);
1081 if (!M->getName().empty()) {
1082 addString(MDie, dwarf::DW_AT_name, M->getName());
1083 addGlobalName(M->getName(), MDie, M->getScope());
1085 if (!M->getConfigurationMacros().empty())
1086 addString(MDie, dwarf::DW_AT_LLVM_config_macros,
1087 M->getConfigurationMacros());
1088 if (!M->getIncludePath().empty())
1089 addString(MDie, dwarf::DW_AT_LLVM_include_path, M->getIncludePath());
1090 if (!M->getISysRoot().empty())
1091 addString(MDie, dwarf::DW_AT_LLVM_isysroot, M->getISysRoot());
1096 DIE *DwarfUnit::getOrCreateSubprogramDIE(const DISubprogram *SP, bool Minimal) {
1097 // Construct the context before querying for the existence of the DIE in case
1098 // such construction creates the DIE (as is the case for member function
1101 Minimal ? &getUnitDie() : getOrCreateContextDIE(resolve(SP->getScope()));
1103 if (DIE *SPDie = getDIE(SP))
1106 if (auto *SPDecl = SP->getDeclaration()) {
1108 // Add subprogram definitions to the CU die directly.
1109 ContextDIE = &getUnitDie();
1110 // Build the decl now to ensure it precedes the definition.
1111 getOrCreateSubprogramDIE(SPDecl);
1115 // DW_TAG_inlined_subroutine may refer to this DIE.
1116 DIE &SPDie = createAndAddDIE(dwarf::DW_TAG_subprogram, *ContextDIE, SP);
1118 // Stop here and fill this in later, depending on whether or not this
1119 // subprogram turns out to have inlined instances or not.
1120 if (SP->isDefinition())
1123 applySubprogramAttributes(SP, SPDie);
1127 bool DwarfUnit::applySubprogramDefinitionAttributes(const DISubprogram *SP,
1129 DIE *DeclDie = nullptr;
1130 StringRef DeclLinkageName;
1131 if (auto *SPDecl = SP->getDeclaration()) {
1132 DeclDie = getDIE(SPDecl);
1133 assert(DeclDie && "This DIE should've already been constructed when the "
1134 "definition DIE was created in "
1135 "getOrCreateSubprogramDIE");
1136 DeclLinkageName = SPDecl->getLinkageName();
1138 getOrCreateSourceID(SPDecl->getFilename(), SPDecl->getDirectory());
1139 unsigned DefID = getOrCreateSourceID(SP->getFilename(), SP->getDirectory());
1140 if (DeclID != DefID)
1141 addUInt(SPDie, dwarf::DW_AT_decl_file, None, DefID);
1143 if (SP->getLine() != SPDecl->getLine())
1144 addUInt(SPDie, dwarf::DW_AT_decl_line, None, SP->getLine());
1147 // Add function template parameters.
1148 addTemplateParams(SPDie, SP->getTemplateParams());
1150 // Add the linkage name if we have one and it isn't in the Decl.
1151 StringRef LinkageName = SP->getLinkageName();
1152 assert(((LinkageName.empty() || DeclLinkageName.empty()) ||
1153 LinkageName == DeclLinkageName) &&
1154 "decl has a linkage name and it is different");
1155 if (DeclLinkageName.empty() &&
1156 // Always emit it for abstract subprograms.
1157 (DD->useAllLinkageNames() || DU->getAbstractSPDies().lookup(SP)))
1158 addLinkageName(SPDie, LinkageName);
1163 // Refer to the function declaration where all the other attributes will be
1165 addDIEEntry(SPDie, dwarf::DW_AT_specification, *DeclDie);
1169 void DwarfUnit::applySubprogramAttributes(const DISubprogram *SP, DIE &SPDie,
1172 if (applySubprogramDefinitionAttributes(SP, SPDie))
1175 // Constructors and operators for anonymous aggregates do not have names.
1176 if (!SP->getName().empty())
1177 addString(SPDie, dwarf::DW_AT_name, SP->getName());
1179 // Skip the rest of the attributes under -gmlt to save space.
1183 addSourceLine(SPDie, SP);
1185 // Add the prototype if we have a prototype and we have a C like
1187 uint16_t Language = getLanguage();
1188 if (SP->isPrototyped() &&
1189 (Language == dwarf::DW_LANG_C89 || Language == dwarf::DW_LANG_C99 ||
1190 Language == dwarf::DW_LANG_ObjC))
1191 addFlag(SPDie, dwarf::DW_AT_prototyped);
1194 DITypeRefArray Args;
1195 if (const DISubroutineType *SPTy = SP->getType()) {
1196 Args = SPTy->getTypeArray();
1200 // Add a DW_AT_calling_convention if this has an explicit convention.
1201 if (CC && CC != dwarf::DW_CC_normal)
1202 addUInt(SPDie, dwarf::DW_AT_calling_convention, dwarf::DW_FORM_data1, CC);
1204 // Add a return type. If this is a type like a C/C++ void type we don't add a
1207 if (auto Ty = resolve(Args[0]))
1210 unsigned VK = SP->getVirtuality();
1212 addUInt(SPDie, dwarf::DW_AT_virtuality, dwarf::DW_FORM_data1, VK);
1213 if (SP->getVirtualIndex() != -1u) {
1214 DIELoc *Block = getDIELoc();
1215 addUInt(*Block, dwarf::DW_FORM_data1, dwarf::DW_OP_constu);
1216 addUInt(*Block, dwarf::DW_FORM_udata, SP->getVirtualIndex());
1217 addBlock(SPDie, dwarf::DW_AT_vtable_elem_location, Block);
1219 ContainingTypeMap.insert(
1220 std::make_pair(&SPDie, resolve(SP->getContainingType())));
1223 if (!SP->isDefinition()) {
1224 addFlag(SPDie, dwarf::DW_AT_declaration);
1226 // Add arguments. Do not add arguments for subprogram definition. They will
1227 // be handled while processing variables.
1228 constructSubprogramArguments(SPDie, Args);
1231 if (SP->isArtificial())
1232 addFlag(SPDie, dwarf::DW_AT_artificial);
1234 if (!SP->isLocalToUnit())
1235 addFlag(SPDie, dwarf::DW_AT_external);
1237 if (DD->useAppleExtensionAttributes()) {
1238 if (SP->isOptimized())
1239 addFlag(SPDie, dwarf::DW_AT_APPLE_optimized);
1241 if (unsigned isa = Asm->getISAEncoding())
1242 addUInt(SPDie, dwarf::DW_AT_APPLE_isa, dwarf::DW_FORM_flag, isa);
1245 if (SP->isLValueReference())
1246 addFlag(SPDie, dwarf::DW_AT_reference);
1248 if (SP->isRValueReference())
1249 addFlag(SPDie, dwarf::DW_AT_rvalue_reference);
1251 if (SP->isProtected())
1252 addUInt(SPDie, dwarf::DW_AT_accessibility, dwarf::DW_FORM_data1,
1253 dwarf::DW_ACCESS_protected);
1254 else if (SP->isPrivate())
1255 addUInt(SPDie, dwarf::DW_AT_accessibility, dwarf::DW_FORM_data1,
1256 dwarf::DW_ACCESS_private);
1257 else if (SP->isPublic())
1258 addUInt(SPDie, dwarf::DW_AT_accessibility, dwarf::DW_FORM_data1,
1259 dwarf::DW_ACCESS_public);
1261 if (SP->isExplicit())
1262 addFlag(SPDie, dwarf::DW_AT_explicit);
1265 void DwarfUnit::constructSubrangeDIE(DIE &Buffer, const DISubrange *SR,
1267 DIE &DW_Subrange = createAndAddDIE(dwarf::DW_TAG_subrange_type, Buffer);
1268 addDIEEntry(DW_Subrange, dwarf::DW_AT_type, *IndexTy);
1270 // The LowerBound value defines the lower bounds which is typically zero for
1271 // C/C++. The Count value is the number of elements. Values are 64 bit. If
1272 // Count == -1 then the array is unbounded and we do not emit
1273 // DW_AT_lower_bound and DW_AT_count attributes.
1274 int64_t LowerBound = SR->getLowerBound();
1275 int64_t DefaultLowerBound = getDefaultLowerBound();
1276 int64_t Count = SR->getCount();
1278 if (DefaultLowerBound == -1 || LowerBound != DefaultLowerBound)
1279 addUInt(DW_Subrange, dwarf::DW_AT_lower_bound, None, LowerBound);
1282 // FIXME: An unbounded array should reference the expression that defines
1284 addUInt(DW_Subrange, dwarf::DW_AT_count, None, Count);
1287 DIE *DwarfUnit::getIndexTyDie() {
1290 // Construct an integer type to use for indexes.
1291 IndexTyDie = &createAndAddDIE(dwarf::DW_TAG_base_type, UnitDie);
1292 addString(*IndexTyDie, dwarf::DW_AT_name, "sizetype");
1293 addUInt(*IndexTyDie, dwarf::DW_AT_byte_size, None, sizeof(int64_t));
1294 addUInt(*IndexTyDie, dwarf::DW_AT_encoding, dwarf::DW_FORM_data1,
1295 dwarf::DW_ATE_unsigned);
1299 void DwarfUnit::constructArrayTypeDIE(DIE &Buffer, const DICompositeType *CTy) {
1300 if (CTy->isVector())
1301 addFlag(Buffer, dwarf::DW_AT_GNU_vector);
1303 // Emit the element type.
1304 addType(Buffer, resolve(CTy->getBaseType()));
1306 // Get an anonymous type for index type.
1307 // FIXME: This type should be passed down from the front end
1308 // as different languages may have different sizes for indexes.
1309 DIE *IdxTy = getIndexTyDie();
1311 // Add subranges to array type.
1312 DINodeArray Elements = CTy->getElements();
1313 for (unsigned i = 0, N = Elements.size(); i < N; ++i) {
1314 // FIXME: Should this really be such a loose cast?
1315 if (auto *Element = dyn_cast_or_null<DINode>(Elements[i]))
1316 if (Element->getTag() == dwarf::DW_TAG_subrange_type)
1317 constructSubrangeDIE(Buffer, cast<DISubrange>(Element), IdxTy);
1321 void DwarfUnit::constructEnumTypeDIE(DIE &Buffer, const DICompositeType *CTy) {
1322 DINodeArray Elements = CTy->getElements();
1324 // Add enumerators to enumeration type.
1325 for (unsigned i = 0, N = Elements.size(); i < N; ++i) {
1326 auto *Enum = dyn_cast_or_null<DIEnumerator>(Elements[i]);
1328 DIE &Enumerator = createAndAddDIE(dwarf::DW_TAG_enumerator, Buffer);
1329 StringRef Name = Enum->getName();
1330 addString(Enumerator, dwarf::DW_AT_name, Name);
1331 int64_t Value = Enum->getValue();
1332 addSInt(Enumerator, dwarf::DW_AT_const_value, dwarf::DW_FORM_sdata,
1336 const DIType *DTy = resolve(CTy->getBaseType());
1338 addType(Buffer, DTy);
1339 addFlag(Buffer, dwarf::DW_AT_enum_class);
1343 void DwarfUnit::constructContainingTypeDIEs() {
1344 for (auto CI = ContainingTypeMap.begin(), CE = ContainingTypeMap.end();
1346 DIE &SPDie = *CI->first;
1347 const DINode *D = CI->second;
1350 DIE *NDie = getDIE(D);
1353 addDIEEntry(SPDie, dwarf::DW_AT_containing_type, *NDie);
1357 void DwarfUnit::constructMemberDIE(DIE &Buffer, const DIDerivedType *DT) {
1358 DIE &MemberDie = createAndAddDIE(DT->getTag(), Buffer);
1359 StringRef Name = DT->getName();
1361 addString(MemberDie, dwarf::DW_AT_name, Name);
1363 addType(MemberDie, resolve(DT->getBaseType()));
1365 addSourceLine(MemberDie, DT);
1367 if (DT->getTag() == dwarf::DW_TAG_inheritance && DT->isVirtual()) {
1369 // For C++, virtual base classes are not at fixed offset. Use following
1370 // expression to extract appropriate offset from vtable.
1371 // BaseAddr = ObAddr + *((*ObAddr) - Offset)
1373 DIELoc *VBaseLocationDie = new (DIEValueAllocator) DIELoc;
1374 addUInt(*VBaseLocationDie, dwarf::DW_FORM_data1, dwarf::DW_OP_dup);
1375 addUInt(*VBaseLocationDie, dwarf::DW_FORM_data1, dwarf::DW_OP_deref);
1376 addUInt(*VBaseLocationDie, dwarf::DW_FORM_data1, dwarf::DW_OP_constu);
1377 addUInt(*VBaseLocationDie, dwarf::DW_FORM_udata, DT->getOffsetInBits());
1378 addUInt(*VBaseLocationDie, dwarf::DW_FORM_data1, dwarf::DW_OP_minus);
1379 addUInt(*VBaseLocationDie, dwarf::DW_FORM_data1, dwarf::DW_OP_deref);
1380 addUInt(*VBaseLocationDie, dwarf::DW_FORM_data1, dwarf::DW_OP_plus);
1382 addBlock(MemberDie, dwarf::DW_AT_data_member_location, VBaseLocationDie);
1384 uint64_t Size = DT->getSizeInBits();
1385 uint64_t FieldSize = DD->getBaseTypeSize(DT);
1386 uint64_t OffsetInBytes;
1388 bool IsBitfield = FieldSize && Size != FieldSize;
1390 // Handle bitfield, assume bytes are 8 bits.
1391 if (DD->useDWARF2Bitfields())
1392 addUInt(MemberDie, dwarf::DW_AT_byte_size, None, FieldSize/8);
1393 addUInt(MemberDie, dwarf::DW_AT_bit_size, None, Size);
1395 uint64_t Offset = DT->getOffsetInBits();
1396 uint64_t Align = DT->getAlignInBits() ? DT->getAlignInBits() : FieldSize;
1397 uint64_t AlignMask = ~(Align - 1);
1398 // The bits from the start of the storage unit to the start of the field.
1399 uint64_t StartBitOffset = Offset - (Offset & AlignMask);
1400 // The byte offset of the field's aligned storage unit inside the struct.
1401 OffsetInBytes = (Offset - StartBitOffset) / 8;
1403 if (DD->useDWARF2Bitfields()) {
1404 uint64_t HiMark = (Offset + FieldSize) & AlignMask;
1405 uint64_t FieldOffset = (HiMark - FieldSize);
1406 Offset -= FieldOffset;
1408 // Maybe we need to work from the other end.
1409 if (Asm->getDataLayout().isLittleEndian())
1410 Offset = FieldSize - (Offset + Size);
1412 addUInt(MemberDie, dwarf::DW_AT_bit_offset, None, Offset);
1413 OffsetInBytes = FieldOffset >> 3;
1415 addUInt(MemberDie, dwarf::DW_AT_data_bit_offset, None, Offset);
1418 // This is not a bitfield.
1419 OffsetInBytes = DT->getOffsetInBits() / 8;
1422 if (DD->getDwarfVersion() <= 2) {
1423 DIELoc *MemLocationDie = new (DIEValueAllocator) DIELoc;
1424 addUInt(*MemLocationDie, dwarf::DW_FORM_data1, dwarf::DW_OP_plus_uconst);
1425 addUInt(*MemLocationDie, dwarf::DW_FORM_udata, OffsetInBytes);
1426 addBlock(MemberDie, dwarf::DW_AT_data_member_location, MemLocationDie);
1427 } else if (!IsBitfield || DD->useDWARF2Bitfields())
1428 addUInt(MemberDie, dwarf::DW_AT_data_member_location, None,
1432 if (DT->isProtected())
1433 addUInt(MemberDie, dwarf::DW_AT_accessibility, dwarf::DW_FORM_data1,
1434 dwarf::DW_ACCESS_protected);
1435 else if (DT->isPrivate())
1436 addUInt(MemberDie, dwarf::DW_AT_accessibility, dwarf::DW_FORM_data1,
1437 dwarf::DW_ACCESS_private);
1438 // Otherwise C++ member and base classes are considered public.
1439 else if (DT->isPublic())
1440 addUInt(MemberDie, dwarf::DW_AT_accessibility, dwarf::DW_FORM_data1,
1441 dwarf::DW_ACCESS_public);
1442 if (DT->isVirtual())
1443 addUInt(MemberDie, dwarf::DW_AT_virtuality, dwarf::DW_FORM_data1,
1444 dwarf::DW_VIRTUALITY_virtual);
1446 // Objective-C properties.
1447 if (DINode *PNode = DT->getObjCProperty())
1448 if (DIE *PDie = getDIE(PNode))
1449 MemberDie.addValue(DIEValueAllocator, dwarf::DW_AT_APPLE_property,
1450 dwarf::DW_FORM_ref4, DIEEntry(*PDie));
1452 if (DT->isArtificial())
1453 addFlag(MemberDie, dwarf::DW_AT_artificial);
1456 DIE *DwarfUnit::getOrCreateStaticMemberDIE(const DIDerivedType *DT) {
1460 // Construct the context before querying for the existence of the DIE in case
1461 // such construction creates the DIE.
1462 DIE *ContextDIE = getOrCreateContextDIE(resolve(DT->getScope()));
1463 assert(dwarf::isType(ContextDIE->getTag()) &&
1464 "Static member should belong to a type.");
1466 if (DIE *StaticMemberDIE = getDIE(DT))
1467 return StaticMemberDIE;
1469 DIE &StaticMemberDIE = createAndAddDIE(DT->getTag(), *ContextDIE, DT);
1471 const DIType *Ty = resolve(DT->getBaseType());
1473 addString(StaticMemberDIE, dwarf::DW_AT_name, DT->getName());
1474 addType(StaticMemberDIE, Ty);
1475 addSourceLine(StaticMemberDIE, DT);
1476 addFlag(StaticMemberDIE, dwarf::DW_AT_external);
1477 addFlag(StaticMemberDIE, dwarf::DW_AT_declaration);
1479 // FIXME: We could omit private if the parent is a class_type, and
1480 // public if the parent is something else.
1481 if (DT->isProtected())
1482 addUInt(StaticMemberDIE, dwarf::DW_AT_accessibility, dwarf::DW_FORM_data1,
1483 dwarf::DW_ACCESS_protected);
1484 else if (DT->isPrivate())
1485 addUInt(StaticMemberDIE, dwarf::DW_AT_accessibility, dwarf::DW_FORM_data1,
1486 dwarf::DW_ACCESS_private);
1487 else if (DT->isPublic())
1488 addUInt(StaticMemberDIE, dwarf::DW_AT_accessibility, dwarf::DW_FORM_data1,
1489 dwarf::DW_ACCESS_public);
1491 if (const ConstantInt *CI = dyn_cast_or_null<ConstantInt>(DT->getConstant()))
1492 addConstantValue(StaticMemberDIE, CI, Ty);
1493 if (const ConstantFP *CFP = dyn_cast_or_null<ConstantFP>(DT->getConstant()))
1494 addConstantFPValue(StaticMemberDIE, CFP);
1496 return &StaticMemberDIE;
1499 void DwarfUnit::emitHeader(bool UseOffsets) {
1500 // Emit size of content not including length itself
1501 Asm->OutStreamer->AddComment("Length of Unit");
1502 Asm->EmitInt32(getHeaderSize() + UnitDie.getSize());
1504 Asm->OutStreamer->AddComment("DWARF version number");
1505 Asm->EmitInt16(DD->getDwarfVersion());
1506 Asm->OutStreamer->AddComment("Offset Into Abbrev. Section");
1508 // We share one abbreviations table across all units so it's always at the
1509 // start of the section. Use a relocatable offset where needed to ensure
1510 // linking doesn't invalidate that offset.
1511 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
1515 Asm->emitDwarfSymbolReference(
1516 TLOF.getDwarfAbbrevSection()->getBeginSymbol(), false);
1518 Asm->OutStreamer->AddComment("Address Size (in bytes)");
1519 Asm->EmitInt8(Asm->getDataLayout().getPointerSize());
1522 void DwarfUnit::initSection(MCSection *Section) {
1523 assert(!this->Section);
1524 this->Section = Section;
1527 void DwarfTypeUnit::emitHeader(bool UseOffsets) {
1528 DwarfUnit::emitHeader(UseOffsets);
1529 Asm->OutStreamer->AddComment("Type Signature");
1530 Asm->OutStreamer->EmitIntValue(TypeSignature, sizeof(TypeSignature));
1531 Asm->OutStreamer->AddComment("Type DIE Offset");
1532 // In a skeleton type unit there is no type DIE so emit a zero offset.
1533 Asm->OutStreamer->EmitIntValue(Ty ? Ty->getOffset() : 0,
1534 sizeof(Ty->getOffset()));
1537 bool DwarfTypeUnit::isDwoUnit() const {
1538 // Since there are no skeleton type units, all type units are dwo type units
1539 // when split DWARF is being used.
1540 return DD->useSplitDwarf();