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.MF->getSubtarget().getRegisterInfo(),
50 AP.getDwarfDebug()->getDwarfVersion()),
51 AP(AP), DU(DU), DIE(DIE) {}
53 void DIEDwarfExpression::EmitOp(uint8_t Op, const char* Comment) {
54 DU.addUInt(DIE, dwarf::DW_FORM_data1, Op);
56 void DIEDwarfExpression::EmitSigned(int64_t Value) {
57 DU.addSInt(DIE, dwarf::DW_FORM_sdata, Value);
59 void DIEDwarfExpression::EmitUnsigned(uint64_t Value) {
60 DU.addUInt(DIE, dwarf::DW_FORM_udata, Value);
62 bool DIEDwarfExpression::isFrameRegister(unsigned MachineReg) {
63 return MachineReg == TRI.getFrameRegister(*AP.MF);
66 DwarfUnit::DwarfUnit(unsigned UID, dwarf::Tag UnitTag,
67 const DICompileUnit *Node, AsmPrinter *A, DwarfDebug *DW,
69 : UniqueID(UID), CUNode(Node),
70 UnitDie(*DIE::get(DIEValueAllocator, UnitTag)), DebugInfoOffset(0),
71 Asm(A), DD(DW), DU(DWU), IndexTyDie(nullptr), Section(nullptr) {
72 assert(UnitTag == dwarf::DW_TAG_compile_unit ||
73 UnitTag == dwarf::DW_TAG_type_unit);
76 DwarfTypeUnit::DwarfTypeUnit(unsigned UID, DwarfCompileUnit &CU, AsmPrinter *A,
77 DwarfDebug *DW, DwarfFile *DWU,
78 MCDwarfDwoLineTable *SplitLineTable)
79 : DwarfUnit(UID, dwarf::DW_TAG_type_unit, CU.getCUNode(), A, DW, DWU),
80 CU(CU), SplitLineTable(SplitLineTable) {
82 addSectionOffset(UnitDie, dwarf::DW_AT_stmt_list, 0);
85 DwarfUnit::~DwarfUnit() {
86 for (unsigned j = 0, M = DIEBlocks.size(); j < M; ++j)
87 DIEBlocks[j]->~DIEBlock();
88 for (unsigned j = 0, M = DIELocs.size(); j < M; ++j)
89 DIELocs[j]->~DIELoc();
92 int64_t DwarfUnit::getDefaultLowerBound() const {
93 switch (getLanguage()) {
97 case dwarf::DW_LANG_C89:
98 case dwarf::DW_LANG_C99:
99 case dwarf::DW_LANG_C:
100 case dwarf::DW_LANG_C_plus_plus:
101 case dwarf::DW_LANG_ObjC:
102 case dwarf::DW_LANG_ObjC_plus_plus:
105 case dwarf::DW_LANG_Fortran77:
106 case dwarf::DW_LANG_Fortran90:
107 case dwarf::DW_LANG_Fortran95:
110 // The languages below have valid values only if the DWARF version >= 4.
111 case dwarf::DW_LANG_Java:
112 case dwarf::DW_LANG_Python:
113 case dwarf::DW_LANG_UPC:
114 case dwarf::DW_LANG_D:
115 if (dwarf::DWARF_VERSION >= 4)
119 case dwarf::DW_LANG_Ada83:
120 case dwarf::DW_LANG_Ada95:
121 case dwarf::DW_LANG_Cobol74:
122 case dwarf::DW_LANG_Cobol85:
123 case dwarf::DW_LANG_Modula2:
124 case dwarf::DW_LANG_Pascal83:
125 case dwarf::DW_LANG_PLI:
126 if (dwarf::DWARF_VERSION >= 4)
130 // The languages below have valid values only if the DWARF version >= 5.
131 case dwarf::DW_LANG_OpenCL:
132 case dwarf::DW_LANG_Go:
133 case dwarf::DW_LANG_Haskell:
134 case dwarf::DW_LANG_C_plus_plus_03:
135 case dwarf::DW_LANG_C_plus_plus_11:
136 case dwarf::DW_LANG_OCaml:
137 case dwarf::DW_LANG_Rust:
138 case dwarf::DW_LANG_C11:
139 case dwarf::DW_LANG_Swift:
140 case dwarf::DW_LANG_Dylan:
141 case dwarf::DW_LANG_C_plus_plus_14:
142 if (dwarf::DWARF_VERSION >= 5)
146 case dwarf::DW_LANG_Modula3:
147 case dwarf::DW_LANG_Julia:
148 case dwarf::DW_LANG_Fortran03:
149 case dwarf::DW_LANG_Fortran08:
150 if (dwarf::DWARF_VERSION >= 5)
158 /// Check whether the DIE for this MDNode can be shared across CUs.
159 static bool isShareableAcrossCUs(const DINode *D) {
160 // When the MDNode can be part of the type system, the DIE can be shared
162 // Combining type units and cross-CU DIE sharing is lower value (since
163 // cross-CU DIE sharing is used in LTO and removes type redundancy at that
164 // level already) but may be implementable for some value in projects
165 // building multiple independent libraries with LTO and then linking those
167 return (isa<DIType>(D) ||
168 (isa<DISubprogram>(D) && !cast<DISubprogram>(D)->isDefinition())) &&
169 !GenerateDwarfTypeUnits;
172 DIE *DwarfUnit::getDIE(const DINode *D) const {
173 if (isShareableAcrossCUs(D))
174 return DU->getDIE(D);
175 return MDNodeToDieMap.lookup(D);
178 void DwarfUnit::insertDIE(const DINode *Desc, DIE *D) {
179 if (isShareableAcrossCUs(Desc)) {
180 DU->insertDIE(Desc, D);
183 MDNodeToDieMap.insert(std::make_pair(Desc, D));
186 void DwarfUnit::addFlag(DIE &Die, dwarf::Attribute Attribute) {
187 if (DD->getDwarfVersion() >= 4)
188 Die.addValue(DIEValueAllocator, Attribute, dwarf::DW_FORM_flag_present,
191 Die.addValue(DIEValueAllocator, Attribute, dwarf::DW_FORM_flag,
195 void DwarfUnit::addUInt(DIEValueList &Die, dwarf::Attribute Attribute,
196 Optional<dwarf::Form> Form, uint64_t Integer) {
198 Form = DIEInteger::BestForm(false, Integer);
199 Die.addValue(DIEValueAllocator, Attribute, *Form, DIEInteger(Integer));
202 void DwarfUnit::addUInt(DIEValueList &Block, dwarf::Form Form,
204 addUInt(Block, (dwarf::Attribute)0, Form, Integer);
207 void DwarfUnit::addSInt(DIEValueList &Die, dwarf::Attribute Attribute,
208 Optional<dwarf::Form> Form, int64_t Integer) {
210 Form = DIEInteger::BestForm(true, Integer);
211 Die.addValue(DIEValueAllocator, Attribute, *Form, DIEInteger(Integer));
214 void DwarfUnit::addSInt(DIELoc &Die, Optional<dwarf::Form> Form,
216 addSInt(Die, (dwarf::Attribute)0, Form, Integer);
219 void DwarfUnit::addString(DIE &Die, dwarf::Attribute Attribute,
221 Die.addValue(DIEValueAllocator, Attribute,
222 isDwoUnit() ? dwarf::DW_FORM_GNU_str_index : dwarf::DW_FORM_strp,
223 DIEString(DU->getStringPool().getEntry(*Asm, String)));
226 DIEValueList::value_iterator DwarfUnit::addLabel(DIEValueList &Die,
227 dwarf::Attribute Attribute,
229 const MCSymbol *Label) {
230 return Die.addValue(DIEValueAllocator, Attribute, Form, DIELabel(Label));
233 void DwarfUnit::addLabel(DIELoc &Die, dwarf::Form Form, const MCSymbol *Label) {
234 addLabel(Die, (dwarf::Attribute)0, Form, Label);
237 void DwarfUnit::addSectionOffset(DIE &Die, dwarf::Attribute Attribute,
239 if (DD->getDwarfVersion() >= 4)
240 addUInt(Die, Attribute, dwarf::DW_FORM_sec_offset, Integer);
242 addUInt(Die, Attribute, dwarf::DW_FORM_data4, Integer);
245 unsigned DwarfTypeUnit::getOrCreateSourceID(StringRef FileName, StringRef DirName) {
246 return SplitLineTable ? SplitLineTable->getFile(DirName, FileName)
247 : getCU().getOrCreateSourceID(FileName, DirName);
250 void DwarfUnit::addOpAddress(DIELoc &Die, const MCSymbol *Sym) {
251 if (!DD->useSplitDwarf()) {
252 addUInt(Die, dwarf::DW_FORM_data1, dwarf::DW_OP_addr);
253 addLabel(Die, dwarf::DW_FORM_udata, Sym);
255 addUInt(Die, dwarf::DW_FORM_data1, dwarf::DW_OP_GNU_addr_index);
256 addUInt(Die, dwarf::DW_FORM_GNU_addr_index,
257 DD->getAddressPool().getIndex(Sym));
261 void DwarfUnit::addLabelDelta(DIE &Die, dwarf::Attribute Attribute,
262 const MCSymbol *Hi, const MCSymbol *Lo) {
263 Die.addValue(DIEValueAllocator, Attribute, dwarf::DW_FORM_data4,
264 new (DIEValueAllocator) DIEDelta(Hi, Lo));
267 void DwarfUnit::addDIEEntry(DIE &Die, dwarf::Attribute Attribute, DIE &Entry) {
268 addDIEEntry(Die, Attribute, DIEEntry(Entry));
271 void DwarfUnit::addDIETypeSignature(DIE &Die, const DwarfTypeUnit &Type) {
272 // Flag the type unit reference as a declaration so that if it contains
273 // members (implicit special members, static data member definitions, member
274 // declarations for definitions in this CU, etc) consumers don't get confused
275 // and think this is a full definition.
276 addFlag(Die, dwarf::DW_AT_declaration);
278 Die.addValue(DIEValueAllocator, dwarf::DW_AT_signature,
279 dwarf::DW_FORM_ref_sig8, DIETypeSignature(Type));
282 void DwarfUnit::addDIETypeSignature(DIE &Die, dwarf::Attribute Attribute,
283 StringRef Identifier) {
284 uint64_t Signature = DD->makeTypeSignature(Identifier);
285 Die.addValue(DIEValueAllocator, Attribute, dwarf::DW_FORM_ref_sig8,
286 DIEInteger(Signature));
289 void DwarfUnit::addDIEEntry(DIE &Die, dwarf::Attribute Attribute,
291 const DIE *DieCU = Die.getUnitOrNull();
292 const DIE *EntryCU = Entry.getEntry().getUnitOrNull();
294 // We assume that Die belongs to this CU, if it is not linked to any CU yet.
295 DieCU = &getUnitDie();
297 EntryCU = &getUnitDie();
298 Die.addValue(DIEValueAllocator, Attribute,
299 EntryCU == DieCU ? dwarf::DW_FORM_ref4 : dwarf::DW_FORM_ref_addr,
303 DIE &DwarfUnit::createAndAddDIE(unsigned Tag, DIE &Parent, const DINode *N) {
304 DIE &Die = Parent.addChild(DIE::get(DIEValueAllocator, (dwarf::Tag)Tag));
310 void DwarfUnit::addBlock(DIE &Die, dwarf::Attribute Attribute, DIELoc *Loc) {
311 Loc->ComputeSize(Asm);
312 DIELocs.push_back(Loc); // Memoize so we can call the destructor later on.
313 Die.addValue(DIEValueAllocator, Attribute,
314 Loc->BestForm(DD->getDwarfVersion()), Loc);
317 void DwarfUnit::addBlock(DIE &Die, dwarf::Attribute Attribute,
319 Block->ComputeSize(Asm);
320 DIEBlocks.push_back(Block); // Memoize so we can call the destructor later on.
321 Die.addValue(DIEValueAllocator, Attribute, Block->BestForm(), Block);
324 void DwarfUnit::addSourceLine(DIE &Die, unsigned Line, StringRef File,
325 StringRef Directory) {
329 unsigned FileID = getOrCreateSourceID(File, Directory);
330 assert(FileID && "Invalid file id");
331 addUInt(Die, dwarf::DW_AT_decl_file, None, FileID);
332 addUInt(Die, dwarf::DW_AT_decl_line, None, Line);
335 void DwarfUnit::addSourceLine(DIE &Die, const DILocalVariable *V) {
338 addSourceLine(Die, V->getLine(), V->getScope()->getFilename(),
339 V->getScope()->getDirectory());
342 void DwarfUnit::addSourceLine(DIE &Die, const DIGlobalVariable *G) {
345 addSourceLine(Die, G->getLine(), G->getFilename(), G->getDirectory());
348 void DwarfUnit::addSourceLine(DIE &Die, const DISubprogram *SP) {
351 addSourceLine(Die, SP->getLine(), SP->getFilename(), SP->getDirectory());
354 void DwarfUnit::addSourceLine(DIE &Die, const DIType *Ty) {
357 addSourceLine(Die, Ty->getLine(), Ty->getFilename(), Ty->getDirectory());
360 void DwarfUnit::addSourceLine(DIE &Die, const DIObjCProperty *Ty) {
363 addSourceLine(Die, Ty->getLine(), Ty->getFilename(), Ty->getDirectory());
366 void DwarfUnit::addSourceLine(DIE &Die, const DINamespace *NS) {
367 addSourceLine(Die, NS->getLine(), NS->getFilename(), NS->getDirectory());
370 bool DwarfUnit::addRegisterOpPiece(DIELoc &TheDie, unsigned Reg,
371 unsigned SizeInBits, unsigned OffsetInBits) {
372 DIEDwarfExpression Expr(*Asm, *this, TheDie);
373 Expr.AddMachineRegPiece(Reg, SizeInBits, OffsetInBits);
377 bool DwarfUnit::addRegisterOffset(DIELoc &TheDie, unsigned Reg,
379 DIEDwarfExpression Expr(*Asm, *this, TheDie);
380 return Expr.AddMachineRegIndirect(Reg, Offset);
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 /// If this type is derived from a base type then return base type size.
565 static uint64_t getBaseTypeSize(DwarfDebug *DD, const DIDerivedType *Ty) {
566 unsigned Tag = Ty->getTag();
568 if (Tag != dwarf::DW_TAG_member && Tag != dwarf::DW_TAG_typedef &&
569 Tag != dwarf::DW_TAG_const_type && Tag != dwarf::DW_TAG_volatile_type &&
570 Tag != dwarf::DW_TAG_restrict_type)
571 return Ty->getSizeInBits();
573 auto *BaseType = DD->resolve(Ty->getBaseType());
575 assert(BaseType && "Unexpected invalid base type");
577 // If this is a derived type, go ahead and get the base type, unless it's a
578 // reference then it's just the size of the field. Pointer types have no need
579 // of this since they're a different type of qualification on the type.
580 if (BaseType->getTag() == dwarf::DW_TAG_reference_type ||
581 BaseType->getTag() == dwarf::DW_TAG_rvalue_reference_type)
582 return Ty->getSizeInBits();
584 if (auto *DT = dyn_cast<DIDerivedType>(BaseType))
585 return getBaseTypeSize(DD, DT);
587 return BaseType->getSizeInBits();
590 void DwarfUnit::addConstantFPValue(DIE &Die, const MachineOperand &MO) {
591 assert(MO.isFPImm() && "Invalid machine operand!");
592 DIEBlock *Block = new (DIEValueAllocator) DIEBlock;
593 APFloat FPImm = MO.getFPImm()->getValueAPF();
595 // Get the raw data form of the floating point.
596 const APInt FltVal = FPImm.bitcastToAPInt();
597 const char *FltPtr = (const char *)FltVal.getRawData();
599 int NumBytes = FltVal.getBitWidth() / 8; // 8 bits per byte.
600 bool LittleEndian = Asm->getDataLayout().isLittleEndian();
601 int Incr = (LittleEndian ? 1 : -1);
602 int Start = (LittleEndian ? 0 : NumBytes - 1);
603 int Stop = (LittleEndian ? NumBytes : -1);
605 // Output the constant to DWARF one byte at a time.
606 for (; Start != Stop; Start += Incr)
607 addUInt(*Block, dwarf::DW_FORM_data1, (unsigned char)0xFF & FltPtr[Start]);
609 addBlock(Die, dwarf::DW_AT_const_value, Block);
612 void DwarfUnit::addConstantFPValue(DIE &Die, const ConstantFP *CFP) {
613 // Pass this down to addConstantValue as an unsigned bag of bits.
614 addConstantValue(Die, CFP->getValueAPF().bitcastToAPInt(), true);
617 void DwarfUnit::addConstantValue(DIE &Die, const ConstantInt *CI,
619 addConstantValue(Die, CI->getValue(), Ty);
622 void DwarfUnit::addConstantValue(DIE &Die, const MachineOperand &MO,
624 assert(MO.isImm() && "Invalid machine operand!");
626 addConstantValue(Die, isUnsignedDIType(DD, Ty), MO.getImm());
629 void DwarfUnit::addConstantValue(DIE &Die, bool Unsigned, uint64_t Val) {
630 // FIXME: This is a bit conservative/simple - it emits negative values always
631 // sign extended to 64 bits rather than minimizing the number of bytes.
632 addUInt(Die, dwarf::DW_AT_const_value,
633 Unsigned ? dwarf::DW_FORM_udata : dwarf::DW_FORM_sdata, Val);
636 void DwarfUnit::addConstantValue(DIE &Die, const APInt &Val, const DIType *Ty) {
637 addConstantValue(Die, Val, isUnsignedDIType(DD, Ty));
640 void DwarfUnit::addConstantValue(DIE &Die, const APInt &Val, bool Unsigned) {
641 unsigned CIBitWidth = Val.getBitWidth();
642 if (CIBitWidth <= 64) {
643 addConstantValue(Die, Unsigned,
644 Unsigned ? Val.getZExtValue() : Val.getSExtValue());
648 DIEBlock *Block = new (DIEValueAllocator) DIEBlock;
650 // Get the raw data form of the large APInt.
651 const uint64_t *Ptr64 = Val.getRawData();
653 int NumBytes = Val.getBitWidth() / 8; // 8 bits per byte.
654 bool LittleEndian = Asm->getDataLayout().isLittleEndian();
656 // Output the constant to DWARF one byte at a time.
657 for (int i = 0; i < NumBytes; i++) {
660 c = Ptr64[i / 8] >> (8 * (i & 7));
662 c = Ptr64[(NumBytes - 1 - i) / 8] >> (8 * ((NumBytes - 1 - i) & 7));
663 addUInt(*Block, dwarf::DW_FORM_data1, c);
666 addBlock(Die, dwarf::DW_AT_const_value, Block);
669 void DwarfUnit::addLinkageName(DIE &Die, StringRef LinkageName) {
670 if (!LinkageName.empty() && DD->useLinkageNames())
672 DD->getDwarfVersion() >= 4 ? dwarf::DW_AT_linkage_name
673 : dwarf::DW_AT_MIPS_linkage_name,
674 GlobalValue::getRealLinkageName(LinkageName));
677 void DwarfUnit::addTemplateParams(DIE &Buffer, DINodeArray TParams) {
678 // Add template parameters.
679 for (const auto *Element : TParams) {
680 if (auto *TTP = dyn_cast<DITemplateTypeParameter>(Element))
681 constructTemplateTypeParameterDIE(Buffer, TTP);
682 else if (auto *TVP = dyn_cast<DITemplateValueParameter>(Element))
683 constructTemplateValueParameterDIE(Buffer, TVP);
687 DIE *DwarfUnit::getOrCreateContextDIE(const DIScope *Context) {
688 if (!Context || isa<DIFile>(Context))
689 return &getUnitDie();
690 if (auto *T = dyn_cast<DIType>(Context))
691 return getOrCreateTypeDIE(T);
692 if (auto *NS = dyn_cast<DINamespace>(Context))
693 return getOrCreateNameSpace(NS);
694 if (auto *SP = dyn_cast<DISubprogram>(Context))
695 return getOrCreateSubprogramDIE(SP);
696 if (auto *M = dyn_cast<DIModule>(Context))
697 return getOrCreateModule(M);
698 return getDIE(Context);
701 DIE *DwarfUnit::createTypeDIE(const DICompositeType *Ty) {
702 auto *Context = resolve(Ty->getScope());
703 DIE *ContextDIE = getOrCreateContextDIE(Context);
705 if (DIE *TyDIE = getDIE(Ty))
709 DIE &TyDIE = createAndAddDIE(Ty->getTag(), *ContextDIE, Ty);
711 constructTypeDIE(TyDIE, cast<DICompositeType>(Ty));
713 if (!Ty->isExternalTypeRef())
714 updateAcceleratorTables(Context, Ty, TyDIE);
718 DIE *DwarfUnit::getOrCreateTypeDIE(const MDNode *TyNode) {
722 auto *Ty = cast<DIType>(TyNode);
723 assert(Ty == resolve(Ty->getRef()) &&
724 "type was not uniqued, possible ODR violation.");
726 // DW_TAG_restrict_type is not supported in DWARF2
727 if (Ty->getTag() == dwarf::DW_TAG_restrict_type && DD->getDwarfVersion() <= 2)
728 return getOrCreateTypeDIE(resolve(cast<DIDerivedType>(Ty)->getBaseType()));
730 // Construct the context before querying for the existence of the DIE in case
731 // such construction creates the DIE.
732 auto *Context = resolve(Ty->getScope());
733 DIE *ContextDIE = getOrCreateContextDIE(Context);
736 if (DIE *TyDIE = getDIE(Ty))
740 DIE &TyDIE = createAndAddDIE(Ty->getTag(), *ContextDIE, Ty);
742 updateAcceleratorTables(Context, Ty, TyDIE);
744 if (auto *BT = dyn_cast<DIBasicType>(Ty))
745 constructTypeDIE(TyDIE, BT);
746 else if (auto *STy = dyn_cast<DISubroutineType>(Ty))
747 constructTypeDIE(TyDIE, STy);
748 else if (auto *CTy = dyn_cast<DICompositeType>(Ty)) {
749 if (GenerateDwarfTypeUnits && !Ty->isForwardDecl())
750 if (MDString *TypeId = CTy->getRawIdentifier()) {
751 DD->addDwarfTypeUnitType(getCU(), TypeId->getString(), TyDIE, CTy);
752 // Skip updating the accelerator tables since this is not the full type.
755 constructTypeDIE(TyDIE, CTy);
757 constructTypeDIE(TyDIE, cast<DIDerivedType>(Ty));
763 void DwarfUnit::updateAcceleratorTables(const DIScope *Context,
764 const DIType *Ty, const DIE &TyDIE) {
765 if (!Ty->getName().empty() && !Ty->isForwardDecl()) {
766 bool IsImplementation = 0;
767 if (auto *CT = dyn_cast<DICompositeType>(Ty)) {
768 // A runtime language of 0 actually means C/C++ and that any
769 // non-negative value is some version of Objective-C/C++.
770 IsImplementation = CT->getRuntimeLang() == 0 || CT->isObjcClassComplete();
772 unsigned Flags = IsImplementation ? dwarf::DW_FLAG_type_implementation : 0;
773 DD->addAccelType(Ty->getName(), TyDIE, Flags);
775 if (!Context || isa<DICompileUnit>(Context) || isa<DIFile>(Context) ||
776 isa<DINamespace>(Context))
777 addGlobalType(Ty, TyDIE, Context);
781 void DwarfUnit::addType(DIE &Entity, const DIType *Ty,
782 dwarf::Attribute Attribute) {
783 assert(Ty && "Trying to add a type that doesn't exist?");
784 addDIEEntry(Entity, Attribute, DIEEntry(*getOrCreateTypeDIE(Ty)));
787 std::string DwarfUnit::getParentContextString(const DIScope *Context) const {
791 // FIXME: Decide whether to implement this for non-C++ languages.
792 if (getLanguage() != dwarf::DW_LANG_C_plus_plus)
796 SmallVector<const DIScope *, 1> Parents;
797 while (!isa<DICompileUnit>(Context)) {
798 Parents.push_back(Context);
799 if (Context->getScope())
800 Context = resolve(Context->getScope());
802 // Structure, etc types will have a NULL context if they're at the top
807 // Reverse iterate over our list to go from the outermost construct to the
809 for (const DIScope *Ctx : make_range(Parents.rbegin(), Parents.rend())) {
810 StringRef Name = Ctx->getName();
811 if (Name.empty() && isa<DINamespace>(Ctx))
812 Name = "(anonymous namespace)";
821 void DwarfUnit::constructTypeDIE(DIE &Buffer, const DIBasicType *BTy) {
822 // Get core information.
823 StringRef Name = BTy->getName();
824 // Add name if not anonymous or intermediate type.
826 addString(Buffer, dwarf::DW_AT_name, Name);
828 // An unspecified type only has a name attribute.
829 if (BTy->getTag() == dwarf::DW_TAG_unspecified_type)
832 addUInt(Buffer, dwarf::DW_AT_encoding, dwarf::DW_FORM_data1,
835 uint64_t Size = BTy->getSizeInBits() >> 3;
836 addUInt(Buffer, dwarf::DW_AT_byte_size, None, Size);
839 void DwarfUnit::constructTypeDIE(DIE &Buffer, const DIDerivedType *DTy) {
840 // Get core information.
841 StringRef Name = DTy->getName();
842 uint64_t Size = DTy->getSizeInBits() >> 3;
843 uint16_t Tag = Buffer.getTag();
845 // Map to main type, void will not have a type.
846 const DIType *FromTy = resolve(DTy->getBaseType());
848 addType(Buffer, FromTy);
850 // Add name if not anonymous or intermediate type.
852 addString(Buffer, dwarf::DW_AT_name, Name);
854 // Add size if non-zero (derived types might be zero-sized.)
855 if (Size && Tag != dwarf::DW_TAG_pointer_type
856 && Tag != dwarf::DW_TAG_ptr_to_member_type
857 && Tag != dwarf::DW_TAG_reference_type
858 && Tag != dwarf::DW_TAG_rvalue_reference_type)
859 addUInt(Buffer, dwarf::DW_AT_byte_size, None, Size);
861 if (Tag == dwarf::DW_TAG_ptr_to_member_type)
863 Buffer, dwarf::DW_AT_containing_type,
864 *getOrCreateTypeDIE(resolve(cast<DIDerivedType>(DTy)->getClassType())));
865 // Add source line info if available and TyDesc is not a forward declaration.
866 if (!DTy->isForwardDecl())
867 addSourceLine(Buffer, DTy);
870 void DwarfUnit::constructSubprogramArguments(DIE &Buffer, DITypeRefArray Args) {
871 for (unsigned i = 1, N = Args.size(); i < N; ++i) {
872 const DIType *Ty = resolve(Args[i]);
874 assert(i == N-1 && "Unspecified parameter must be the last argument");
875 createAndAddDIE(dwarf::DW_TAG_unspecified_parameters, Buffer);
877 DIE &Arg = createAndAddDIE(dwarf::DW_TAG_formal_parameter, Buffer);
879 if (Ty->isArtificial())
880 addFlag(Arg, dwarf::DW_AT_artificial);
885 void DwarfUnit::constructTypeDIE(DIE &Buffer, const DISubroutineType *CTy) {
886 // Add return type. A void return won't have a type.
887 auto Elements = cast<DISubroutineType>(CTy)->getTypeArray();
889 if (auto RTy = resolve(Elements[0]))
890 addType(Buffer, RTy);
892 bool isPrototyped = true;
893 if (Elements.size() == 2 && !Elements[1])
894 isPrototyped = false;
896 constructSubprogramArguments(Buffer, Elements);
898 // Add prototype flag if we're dealing with a C language and the function has
900 uint16_t Language = getLanguage();
902 (Language == dwarf::DW_LANG_C89 || Language == dwarf::DW_LANG_C99 ||
903 Language == dwarf::DW_LANG_ObjC))
904 addFlag(Buffer, dwarf::DW_AT_prototyped);
906 if (CTy->isLValueReference())
907 addFlag(Buffer, dwarf::DW_AT_reference);
909 if (CTy->isRValueReference())
910 addFlag(Buffer, dwarf::DW_AT_rvalue_reference);
913 void DwarfUnit::constructTypeDIE(DIE &Buffer, const DICompositeType *CTy) {
914 if (CTy->isExternalTypeRef()) {
915 StringRef Identifier = CTy->getIdentifier();
916 assert(!Identifier.empty() && "external type ref without identifier");
917 addFlag(Buffer, dwarf::DW_AT_declaration);
918 return addDIETypeSignature(Buffer, dwarf::DW_AT_signature, Identifier);
921 // Add name if not anonymous or intermediate type.
922 StringRef Name = CTy->getName();
924 uint64_t Size = CTy->getSizeInBits() >> 3;
925 uint16_t Tag = Buffer.getTag();
928 case dwarf::DW_TAG_array_type:
929 constructArrayTypeDIE(Buffer, CTy);
931 case dwarf::DW_TAG_enumeration_type:
932 constructEnumTypeDIE(Buffer, CTy);
934 case dwarf::DW_TAG_structure_type:
935 case dwarf::DW_TAG_union_type:
936 case dwarf::DW_TAG_class_type: {
937 // Add elements to structure type.
938 DINodeArray Elements = CTy->getElements();
939 for (const auto *Element : Elements) {
942 if (auto *SP = dyn_cast<DISubprogram>(Element))
943 getOrCreateSubprogramDIE(SP);
944 else if (auto *DDTy = dyn_cast<DIDerivedType>(Element)) {
945 if (DDTy->getTag() == dwarf::DW_TAG_friend) {
946 DIE &ElemDie = createAndAddDIE(dwarf::DW_TAG_friend, Buffer);
947 addType(ElemDie, resolve(DDTy->getBaseType()), dwarf::DW_AT_friend);
948 } else if (DDTy->isStaticMember()) {
949 getOrCreateStaticMemberDIE(DDTy);
951 constructMemberDIE(Buffer, DDTy);
953 } else if (auto *Property = dyn_cast<DIObjCProperty>(Element)) {
954 DIE &ElemDie = createAndAddDIE(Property->getTag(), Buffer);
955 StringRef PropertyName = Property->getName();
956 addString(ElemDie, dwarf::DW_AT_APPLE_property_name, PropertyName);
957 if (Property->getType())
958 addType(ElemDie, resolve(Property->getType()));
959 addSourceLine(ElemDie, Property);
960 StringRef GetterName = Property->getGetterName();
961 if (!GetterName.empty())
962 addString(ElemDie, dwarf::DW_AT_APPLE_property_getter, GetterName);
963 StringRef SetterName = Property->getSetterName();
964 if (!SetterName.empty())
965 addString(ElemDie, dwarf::DW_AT_APPLE_property_setter, SetterName);
966 if (unsigned PropertyAttributes = Property->getAttributes())
967 addUInt(ElemDie, dwarf::DW_AT_APPLE_property_attribute, None,
972 if (CTy->isAppleBlockExtension())
973 addFlag(Buffer, dwarf::DW_AT_APPLE_block);
975 // This is outside the DWARF spec, but GDB expects a DW_AT_containing_type
976 // inside C++ composite types to point to the base class with the vtable.
977 if (auto *ContainingType =
978 dyn_cast_or_null<DICompositeType>(resolve(CTy->getVTableHolder())))
979 addDIEEntry(Buffer, dwarf::DW_AT_containing_type,
980 *getOrCreateTypeDIE(ContainingType));
982 if (CTy->isObjcClassComplete())
983 addFlag(Buffer, dwarf::DW_AT_APPLE_objc_complete_type);
985 // Add template parameters to a class, structure or union types.
986 // FIXME: The support isn't in the metadata for this yet.
987 if (Tag == dwarf::DW_TAG_class_type ||
988 Tag == dwarf::DW_TAG_structure_type || Tag == dwarf::DW_TAG_union_type)
989 addTemplateParams(Buffer, CTy->getTemplateParams());
997 // Add name if not anonymous or intermediate type.
999 addString(Buffer, dwarf::DW_AT_name, Name);
1001 if (Tag == dwarf::DW_TAG_enumeration_type ||
1002 Tag == dwarf::DW_TAG_class_type || Tag == dwarf::DW_TAG_structure_type ||
1003 Tag == dwarf::DW_TAG_union_type) {
1004 // Add size if non-zero (derived types might be zero-sized.)
1005 // TODO: Do we care about size for enum forward declarations?
1007 addUInt(Buffer, dwarf::DW_AT_byte_size, None, Size);
1008 else if (!CTy->isForwardDecl())
1009 // Add zero size if it is not a forward declaration.
1010 addUInt(Buffer, dwarf::DW_AT_byte_size, None, 0);
1012 // If we're a forward decl, say so.
1013 if (CTy->isForwardDecl())
1014 addFlag(Buffer, dwarf::DW_AT_declaration);
1016 // Add source line info if available.
1017 if (!CTy->isForwardDecl())
1018 addSourceLine(Buffer, CTy);
1020 // No harm in adding the runtime language to the declaration.
1021 unsigned RLang = CTy->getRuntimeLang();
1023 addUInt(Buffer, dwarf::DW_AT_APPLE_runtime_class, dwarf::DW_FORM_data1,
1028 void DwarfUnit::constructTemplateTypeParameterDIE(
1029 DIE &Buffer, const DITemplateTypeParameter *TP) {
1031 createAndAddDIE(dwarf::DW_TAG_template_type_parameter, Buffer);
1032 // Add the type if it exists, it could be void and therefore no type.
1034 addType(ParamDIE, resolve(TP->getType()));
1035 if (!TP->getName().empty())
1036 addString(ParamDIE, dwarf::DW_AT_name, TP->getName());
1039 void DwarfUnit::constructTemplateValueParameterDIE(
1040 DIE &Buffer, const DITemplateValueParameter *VP) {
1041 DIE &ParamDIE = createAndAddDIE(VP->getTag(), Buffer);
1043 // Add the type if there is one, template template and template parameter
1044 // packs will not have a type.
1045 if (VP->getTag() == dwarf::DW_TAG_template_value_parameter)
1046 addType(ParamDIE, resolve(VP->getType()));
1047 if (!VP->getName().empty())
1048 addString(ParamDIE, dwarf::DW_AT_name, VP->getName());
1049 if (Metadata *Val = VP->getValue()) {
1050 if (ConstantInt *CI = mdconst::dyn_extract<ConstantInt>(Val))
1051 addConstantValue(ParamDIE, CI, resolve(VP->getType()));
1052 else if (GlobalValue *GV = mdconst::dyn_extract<GlobalValue>(Val)) {
1053 // For declaration non-type template parameters (such as global values and
1055 DIELoc *Loc = new (DIEValueAllocator) DIELoc;
1056 addOpAddress(*Loc, Asm->getSymbol(GV));
1057 // Emit DW_OP_stack_value to use the address as the immediate value of the
1058 // parameter, rather than a pointer to it.
1059 addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_stack_value);
1060 addBlock(ParamDIE, dwarf::DW_AT_location, Loc);
1061 } else if (VP->getTag() == dwarf::DW_TAG_GNU_template_template_param) {
1062 assert(isa<MDString>(Val));
1063 addString(ParamDIE, dwarf::DW_AT_GNU_template_name,
1064 cast<MDString>(Val)->getString());
1065 } else if (VP->getTag() == dwarf::DW_TAG_GNU_template_parameter_pack) {
1066 addTemplateParams(ParamDIE, cast<MDTuple>(Val));
1071 DIE *DwarfUnit::getOrCreateNameSpace(const DINamespace *NS) {
1072 // Construct the context before querying for the existence of the DIE in case
1073 // such construction creates the DIE.
1074 DIE *ContextDIE = getOrCreateContextDIE(NS->getScope());
1076 if (DIE *NDie = getDIE(NS))
1078 DIE &NDie = createAndAddDIE(dwarf::DW_TAG_namespace, *ContextDIE, NS);
1080 StringRef Name = NS->getName();
1082 addString(NDie, dwarf::DW_AT_name, NS->getName());
1084 Name = "(anonymous namespace)";
1085 DD->addAccelNamespace(Name, NDie);
1086 addGlobalName(Name, NDie, NS->getScope());
1087 addSourceLine(NDie, NS);
1091 DIE *DwarfUnit::getOrCreateModule(const DIModule *M) {
1092 // Construct the context before querying for the existence of the DIE in case
1093 // such construction creates the DIE.
1094 DIE *ContextDIE = getOrCreateContextDIE(M->getScope());
1096 if (DIE *MDie = getDIE(M))
1098 DIE &MDie = createAndAddDIE(dwarf::DW_TAG_module, *ContextDIE, M);
1100 if (!M->getName().empty()) {
1101 addString(MDie, dwarf::DW_AT_name, M->getName());
1102 addGlobalName(M->getName(), MDie, M->getScope());
1104 if (!M->getConfigurationMacros().empty())
1105 addString(MDie, dwarf::DW_AT_LLVM_config_macros,
1106 M->getConfigurationMacros());
1107 if (!M->getIncludePath().empty())
1108 addString(MDie, dwarf::DW_AT_LLVM_include_path, M->getIncludePath());
1109 if (!M->getISysRoot().empty())
1110 addString(MDie, dwarf::DW_AT_LLVM_isysroot, M->getISysRoot());
1115 DIE *DwarfUnit::getOrCreateSubprogramDIE(const DISubprogram *SP, bool Minimal) {
1116 // Construct the context before querying for the existence of the DIE in case
1117 // such construction creates the DIE (as is the case for member function
1120 Minimal ? &getUnitDie() : getOrCreateContextDIE(resolve(SP->getScope()));
1122 if (DIE *SPDie = getDIE(SP))
1125 if (auto *SPDecl = SP->getDeclaration()) {
1127 // Add subprogram definitions to the CU die directly.
1128 ContextDIE = &getUnitDie();
1129 // Build the decl now to ensure it precedes the definition.
1130 getOrCreateSubprogramDIE(SPDecl);
1134 // DW_TAG_inlined_subroutine may refer to this DIE.
1135 DIE &SPDie = createAndAddDIE(dwarf::DW_TAG_subprogram, *ContextDIE, SP);
1137 // Stop here and fill this in later, depending on whether or not this
1138 // subprogram turns out to have inlined instances or not.
1139 if (SP->isDefinition())
1142 applySubprogramAttributes(SP, SPDie);
1146 bool DwarfUnit::applySubprogramDefinitionAttributes(const DISubprogram *SP,
1148 DIE *DeclDie = nullptr;
1149 StringRef DeclLinkageName;
1150 if (auto *SPDecl = SP->getDeclaration()) {
1151 DeclDie = getDIE(SPDecl);
1152 assert(DeclDie && "This DIE should've already been constructed when the "
1153 "definition DIE was created in "
1154 "getOrCreateSubprogramDIE");
1155 DeclLinkageName = SPDecl->getLinkageName();
1157 getOrCreateSourceID(SPDecl->getFilename(), SPDecl->getDirectory());
1158 unsigned DefID = getOrCreateSourceID(SP->getFilename(), SP->getDirectory());
1159 if (DeclID != DefID)
1160 addUInt(SPDie, dwarf::DW_AT_decl_file, None, DefID);
1162 if (SP->getLine() != SPDecl->getLine())
1163 addUInt(SPDie, dwarf::DW_AT_decl_line, None, SP->getLine());
1166 // Add function template parameters.
1167 addTemplateParams(SPDie, SP->getTemplateParams());
1169 // Add the linkage name if we have one and it isn't in the Decl.
1170 StringRef LinkageName = SP->getLinkageName();
1171 assert(((LinkageName.empty() || DeclLinkageName.empty()) ||
1172 LinkageName == DeclLinkageName) &&
1173 "decl has a linkage name and it is different");
1174 if (DeclLinkageName.empty())
1175 addLinkageName(SPDie, LinkageName);
1180 // Refer to the function declaration where all the other attributes will be
1182 addDIEEntry(SPDie, dwarf::DW_AT_specification, *DeclDie);
1186 void DwarfUnit::applySubprogramAttributes(const DISubprogram *SP, DIE &SPDie,
1189 if (applySubprogramDefinitionAttributes(SP, SPDie))
1192 // Constructors and operators for anonymous aggregates do not have names.
1193 if (!SP->getName().empty())
1194 addString(SPDie, dwarf::DW_AT_name, SP->getName());
1196 // Skip the rest of the attributes under -gmlt to save space.
1200 addSourceLine(SPDie, SP);
1202 // Add the prototype if we have a prototype and we have a C like
1204 uint16_t Language = getLanguage();
1205 if (SP->isPrototyped() &&
1206 (Language == dwarf::DW_LANG_C89 || Language == dwarf::DW_LANG_C99 ||
1207 Language == dwarf::DW_LANG_ObjC))
1208 addFlag(SPDie, dwarf::DW_AT_prototyped);
1210 DITypeRefArray Args;
1211 if (const DISubroutineType *SPTy = SP->getType())
1212 Args = SPTy->getTypeArray();
1214 // Add a return type. If this is a type like a C/C++ void type we don't add a
1217 if (auto Ty = resolve(Args[0]))
1220 unsigned VK = SP->getVirtuality();
1222 addUInt(SPDie, dwarf::DW_AT_virtuality, dwarf::DW_FORM_data1, VK);
1223 DIELoc *Block = getDIELoc();
1224 addUInt(*Block, dwarf::DW_FORM_data1, dwarf::DW_OP_constu);
1225 addUInt(*Block, dwarf::DW_FORM_udata, SP->getVirtualIndex());
1226 addBlock(SPDie, dwarf::DW_AT_vtable_elem_location, Block);
1227 ContainingTypeMap.insert(
1228 std::make_pair(&SPDie, resolve(SP->getContainingType())));
1231 if (!SP->isDefinition()) {
1232 addFlag(SPDie, dwarf::DW_AT_declaration);
1234 // Add arguments. Do not add arguments for subprogram definition. They will
1235 // be handled while processing variables.
1236 constructSubprogramArguments(SPDie, Args);
1239 if (SP->isArtificial())
1240 addFlag(SPDie, dwarf::DW_AT_artificial);
1242 if (!SP->isLocalToUnit())
1243 addFlag(SPDie, dwarf::DW_AT_external);
1245 if (SP->isOptimized())
1246 addFlag(SPDie, dwarf::DW_AT_APPLE_optimized);
1248 if (unsigned isa = Asm->getISAEncoding())
1249 addUInt(SPDie, dwarf::DW_AT_APPLE_isa, dwarf::DW_FORM_flag, isa);
1251 if (SP->isLValueReference())
1252 addFlag(SPDie, dwarf::DW_AT_reference);
1254 if (SP->isRValueReference())
1255 addFlag(SPDie, dwarf::DW_AT_rvalue_reference);
1257 if (SP->isProtected())
1258 addUInt(SPDie, dwarf::DW_AT_accessibility, dwarf::DW_FORM_data1,
1259 dwarf::DW_ACCESS_protected);
1260 else if (SP->isPrivate())
1261 addUInt(SPDie, dwarf::DW_AT_accessibility, dwarf::DW_FORM_data1,
1262 dwarf::DW_ACCESS_private);
1263 else if (SP->isPublic())
1264 addUInt(SPDie, dwarf::DW_AT_accessibility, dwarf::DW_FORM_data1,
1265 dwarf::DW_ACCESS_public);
1267 if (SP->isExplicit())
1268 addFlag(SPDie, dwarf::DW_AT_explicit);
1271 void DwarfUnit::constructSubrangeDIE(DIE &Buffer, const DISubrange *SR,
1273 DIE &DW_Subrange = createAndAddDIE(dwarf::DW_TAG_subrange_type, Buffer);
1274 addDIEEntry(DW_Subrange, dwarf::DW_AT_type, *IndexTy);
1276 // The LowerBound value defines the lower bounds which is typically zero for
1277 // C/C++. The Count value is the number of elements. Values are 64 bit. If
1278 // Count == -1 then the array is unbounded and we do not emit
1279 // DW_AT_lower_bound and DW_AT_count attributes.
1280 int64_t LowerBound = SR->getLowerBound();
1281 int64_t DefaultLowerBound = getDefaultLowerBound();
1282 int64_t Count = SR->getCount();
1284 if (DefaultLowerBound == -1 || LowerBound != DefaultLowerBound)
1285 addUInt(DW_Subrange, dwarf::DW_AT_lower_bound, None, LowerBound);
1288 // FIXME: An unbounded array should reference the expression that defines
1290 addUInt(DW_Subrange, dwarf::DW_AT_count, None, Count);
1293 DIE *DwarfUnit::getIndexTyDie() {
1296 // Construct an integer type to use for indexes.
1297 IndexTyDie = &createAndAddDIE(dwarf::DW_TAG_base_type, UnitDie);
1298 addString(*IndexTyDie, dwarf::DW_AT_name, "sizetype");
1299 addUInt(*IndexTyDie, dwarf::DW_AT_byte_size, None, sizeof(int64_t));
1300 addUInt(*IndexTyDie, dwarf::DW_AT_encoding, dwarf::DW_FORM_data1,
1301 dwarf::DW_ATE_unsigned);
1305 void DwarfUnit::constructArrayTypeDIE(DIE &Buffer, const DICompositeType *CTy) {
1306 if (CTy->isVector())
1307 addFlag(Buffer, dwarf::DW_AT_GNU_vector);
1309 // Emit the element type.
1310 addType(Buffer, resolve(CTy->getBaseType()));
1312 // Get an anonymous type for index type.
1313 // FIXME: This type should be passed down from the front end
1314 // as different languages may have different sizes for indexes.
1315 DIE *IdxTy = getIndexTyDie();
1317 // Add subranges to array type.
1318 DINodeArray Elements = CTy->getElements();
1319 for (unsigned i = 0, N = Elements.size(); i < N; ++i) {
1320 // FIXME: Should this really be such a loose cast?
1321 if (auto *Element = dyn_cast_or_null<DINode>(Elements[i]))
1322 if (Element->getTag() == dwarf::DW_TAG_subrange_type)
1323 constructSubrangeDIE(Buffer, cast<DISubrange>(Element), IdxTy);
1327 void DwarfUnit::constructEnumTypeDIE(DIE &Buffer, const DICompositeType *CTy) {
1328 DINodeArray Elements = CTy->getElements();
1330 // Add enumerators to enumeration type.
1331 for (unsigned i = 0, N = Elements.size(); i < N; ++i) {
1332 auto *Enum = dyn_cast_or_null<DIEnumerator>(Elements[i]);
1334 DIE &Enumerator = createAndAddDIE(dwarf::DW_TAG_enumerator, Buffer);
1335 StringRef Name = Enum->getName();
1336 addString(Enumerator, dwarf::DW_AT_name, Name);
1337 int64_t Value = Enum->getValue();
1338 addSInt(Enumerator, dwarf::DW_AT_const_value, dwarf::DW_FORM_sdata,
1342 const DIType *DTy = resolve(CTy->getBaseType());
1344 addType(Buffer, DTy);
1345 addFlag(Buffer, dwarf::DW_AT_enum_class);
1349 void DwarfUnit::constructContainingTypeDIEs() {
1350 for (auto CI = ContainingTypeMap.begin(), CE = ContainingTypeMap.end();
1352 DIE &SPDie = *CI->first;
1353 const DINode *D = CI->second;
1356 DIE *NDie = getDIE(D);
1359 addDIEEntry(SPDie, dwarf::DW_AT_containing_type, *NDie);
1363 void DwarfUnit::constructMemberDIE(DIE &Buffer, const DIDerivedType *DT) {
1364 DIE &MemberDie = createAndAddDIE(DT->getTag(), Buffer);
1365 StringRef Name = DT->getName();
1367 addString(MemberDie, dwarf::DW_AT_name, Name);
1369 addType(MemberDie, resolve(DT->getBaseType()));
1371 addSourceLine(MemberDie, DT);
1373 if (DT->getTag() == dwarf::DW_TAG_inheritance && DT->isVirtual()) {
1375 // For C++, virtual base classes are not at fixed offset. Use following
1376 // expression to extract appropriate offset from vtable.
1377 // BaseAddr = ObAddr + *((*ObAddr) - Offset)
1379 DIELoc *VBaseLocationDie = new (DIEValueAllocator) DIELoc;
1380 addUInt(*VBaseLocationDie, dwarf::DW_FORM_data1, dwarf::DW_OP_dup);
1381 addUInt(*VBaseLocationDie, dwarf::DW_FORM_data1, dwarf::DW_OP_deref);
1382 addUInt(*VBaseLocationDie, dwarf::DW_FORM_data1, dwarf::DW_OP_constu);
1383 addUInt(*VBaseLocationDie, dwarf::DW_FORM_udata, DT->getOffsetInBits());
1384 addUInt(*VBaseLocationDie, dwarf::DW_FORM_data1, dwarf::DW_OP_minus);
1385 addUInt(*VBaseLocationDie, dwarf::DW_FORM_data1, dwarf::DW_OP_deref);
1386 addUInt(*VBaseLocationDie, dwarf::DW_FORM_data1, dwarf::DW_OP_plus);
1388 addBlock(MemberDie, dwarf::DW_AT_data_member_location, VBaseLocationDie);
1390 uint64_t Size = DT->getSizeInBits();
1391 uint64_t FieldSize = getBaseTypeSize(DD, DT);
1392 uint64_t OffsetInBytes;
1394 if (FieldSize && Size != FieldSize) {
1395 // Handle bitfield, assume bytes are 8 bits.
1396 addUInt(MemberDie, dwarf::DW_AT_byte_size, None, FieldSize/8);
1397 addUInt(MemberDie, dwarf::DW_AT_bit_size, None, Size);
1399 // The DWARF 2 DW_AT_bit_offset is counting the bits between the most
1400 // significant bit of the aligned storage unit containing the bit field to
1401 // the most significan bit of the bit field.
1403 // FIXME: DWARF 4 states that DW_AT_data_bit_offset (which
1404 // counts from the beginning, regardless of endianness) should
1408 // Struct Align Align Align
1410 // +-----------+-----*-----+-----*-----+--
1411 // | ... |b1|b2|b3|b4|
1412 // +-----------+-----*-----+-----*-----+--
1413 // | | |<-- Size ->| |
1414 // |<---- Offset --->| |<--->|
1415 // | | | \_ DW_AT_bit_offset (little endian)
1417 // |<--------->| \_ StartBitOffset = DW_AT_bit_offset (big endian)
1418 // \ = DW_AT_data_bit_offset (biendian)
1420 uint64_t Offset = DT->getOffsetInBits();
1421 uint64_t Align = DT->getAlignInBits() ? DT->getAlignInBits() : FieldSize;
1422 uint64_t AlignMask = ~(Align - 1);
1423 // The bits from the start of the storage unit to the start of the field.
1424 uint64_t StartBitOffset = Offset - (Offset & AlignMask);
1425 // The endian-dependent DWARF 2 offset.
1426 uint64_t DwarfBitOffset = Asm->getDataLayout().isLittleEndian()
1427 ? OffsetToAlignment(Offset + Size, Align)
1430 // The byte offset of the field's aligned storage unit inside the struct.
1431 OffsetInBytes = (Offset - StartBitOffset) / 8;
1432 addUInt(MemberDie, dwarf::DW_AT_bit_offset, None, DwarfBitOffset);
1434 // This is not a bitfield.
1435 OffsetInBytes = DT->getOffsetInBits() / 8;
1437 if (DD->getDwarfVersion() <= 2) {
1438 DIELoc *MemLocationDie = new (DIEValueAllocator) DIELoc;
1439 addUInt(*MemLocationDie, dwarf::DW_FORM_data1, dwarf::DW_OP_plus_uconst);
1440 addUInt(*MemLocationDie, dwarf::DW_FORM_udata, OffsetInBytes);
1441 addBlock(MemberDie, dwarf::DW_AT_data_member_location, MemLocationDie);
1443 addUInt(MemberDie, dwarf::DW_AT_data_member_location, None,
1447 if (DT->isProtected())
1448 addUInt(MemberDie, dwarf::DW_AT_accessibility, dwarf::DW_FORM_data1,
1449 dwarf::DW_ACCESS_protected);
1450 else if (DT->isPrivate())
1451 addUInt(MemberDie, dwarf::DW_AT_accessibility, dwarf::DW_FORM_data1,
1452 dwarf::DW_ACCESS_private);
1453 // Otherwise C++ member and base classes are considered public.
1454 else if (DT->isPublic())
1455 addUInt(MemberDie, dwarf::DW_AT_accessibility, dwarf::DW_FORM_data1,
1456 dwarf::DW_ACCESS_public);
1457 if (DT->isVirtual())
1458 addUInt(MemberDie, dwarf::DW_AT_virtuality, dwarf::DW_FORM_data1,
1459 dwarf::DW_VIRTUALITY_virtual);
1461 // Objective-C properties.
1462 if (DINode *PNode = DT->getObjCProperty())
1463 if (DIE *PDie = getDIE(PNode))
1464 MemberDie.addValue(DIEValueAllocator, dwarf::DW_AT_APPLE_property,
1465 dwarf::DW_FORM_ref4, DIEEntry(*PDie));
1467 if (DT->isArtificial())
1468 addFlag(MemberDie, dwarf::DW_AT_artificial);
1471 DIE *DwarfUnit::getOrCreateStaticMemberDIE(const DIDerivedType *DT) {
1475 // Construct the context before querying for the existence of the DIE in case
1476 // such construction creates the DIE.
1477 DIE *ContextDIE = getOrCreateContextDIE(resolve(DT->getScope()));
1478 assert(dwarf::isType(ContextDIE->getTag()) &&
1479 "Static member should belong to a type.");
1481 if (DIE *StaticMemberDIE = getDIE(DT))
1482 return StaticMemberDIE;
1484 DIE &StaticMemberDIE = createAndAddDIE(DT->getTag(), *ContextDIE, DT);
1486 const DIType *Ty = resolve(DT->getBaseType());
1488 addString(StaticMemberDIE, dwarf::DW_AT_name, DT->getName());
1489 addType(StaticMemberDIE, Ty);
1490 addSourceLine(StaticMemberDIE, DT);
1491 addFlag(StaticMemberDIE, dwarf::DW_AT_external);
1492 addFlag(StaticMemberDIE, dwarf::DW_AT_declaration);
1494 // FIXME: We could omit private if the parent is a class_type, and
1495 // public if the parent is something else.
1496 if (DT->isProtected())
1497 addUInt(StaticMemberDIE, dwarf::DW_AT_accessibility, dwarf::DW_FORM_data1,
1498 dwarf::DW_ACCESS_protected);
1499 else if (DT->isPrivate())
1500 addUInt(StaticMemberDIE, dwarf::DW_AT_accessibility, dwarf::DW_FORM_data1,
1501 dwarf::DW_ACCESS_private);
1502 else if (DT->isPublic())
1503 addUInt(StaticMemberDIE, dwarf::DW_AT_accessibility, dwarf::DW_FORM_data1,
1504 dwarf::DW_ACCESS_public);
1506 if (const ConstantInt *CI = dyn_cast_or_null<ConstantInt>(DT->getConstant()))
1507 addConstantValue(StaticMemberDIE, CI, Ty);
1508 if (const ConstantFP *CFP = dyn_cast_or_null<ConstantFP>(DT->getConstant()))
1509 addConstantFPValue(StaticMemberDIE, CFP);
1511 return &StaticMemberDIE;
1514 void DwarfUnit::emitHeader(bool UseOffsets) {
1515 // Emit size of content not including length itself
1516 Asm->OutStreamer->AddComment("Length of Unit");
1517 Asm->EmitInt32(getHeaderSize() + UnitDie.getSize());
1519 Asm->OutStreamer->AddComment("DWARF version number");
1520 Asm->EmitInt16(DD->getDwarfVersion());
1521 Asm->OutStreamer->AddComment("Offset Into Abbrev. Section");
1523 // We share one abbreviations table across all units so it's always at the
1524 // start of the section. Use a relocatable offset where needed to ensure
1525 // linking doesn't invalidate that offset.
1526 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
1527 Asm->emitDwarfSymbolReference(TLOF.getDwarfAbbrevSection()->getBeginSymbol(),
1530 Asm->OutStreamer->AddComment("Address Size (in bytes)");
1531 Asm->EmitInt8(Asm->getDataLayout().getPointerSize());
1534 void DwarfUnit::initSection(MCSection *Section) {
1535 assert(!this->Section);
1536 this->Section = Section;
1539 void DwarfTypeUnit::emitHeader(bool UseOffsets) {
1540 DwarfUnit::emitHeader(UseOffsets);
1541 Asm->OutStreamer->AddComment("Type Signature");
1542 Asm->OutStreamer->EmitIntValue(TypeSignature, sizeof(TypeSignature));
1543 Asm->OutStreamer->AddComment("Type DIE Offset");
1544 // In a skeleton type unit there is no type DIE so emit a zero offset.
1545 Asm->OutStreamer->EmitIntValue(Ty ? Ty->getOffset() : 0,
1546 sizeof(Ty->getOffset()));
1549 bool DwarfTypeUnit::isDwoUnit() const {
1550 // Since there are no skeleton type units, all type units are dwo type units
1551 // when split DWARF is being used.
1552 return DD->useSplitDwarf();