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);
67 /// Unit - Unit constructor.
68 DwarfUnit::DwarfUnit(unsigned UID, dwarf::Tag UnitTag, DICompileUnit Node,
69 AsmPrinter *A, DwarfDebug *DW, DwarfFile *DWU)
70 : UniqueID(UID), CUNode(Node), UnitDie(UnitTag), DebugInfoOffset(0), Asm(A),
71 DD(DW), DU(DWU), IndexTyDie(nullptr), Section(nullptr) {
72 assert(UnitTag == dwarf::DW_TAG_compile_unit ||
73 UnitTag == dwarf::DW_TAG_type_unit);
74 DIEIntegerOne = new (DIEValueAllocator) DIEInteger(1);
77 DwarfTypeUnit::DwarfTypeUnit(unsigned UID, DwarfCompileUnit &CU, AsmPrinter *A,
78 DwarfDebug *DW, DwarfFile *DWU,
79 MCDwarfDwoLineTable *SplitLineTable)
80 : DwarfUnit(UID, dwarf::DW_TAG_type_unit, CU.getCUNode(), A, DW, DWU),
81 CU(CU), SplitLineTable(SplitLineTable) {
83 addSectionOffset(UnitDie, dwarf::DW_AT_stmt_list, 0);
86 /// ~Unit - Destructor for compile unit.
87 DwarfUnit::~DwarfUnit() {
88 for (unsigned j = 0, M = DIEBlocks.size(); j < M; ++j)
89 DIEBlocks[j]->~DIEBlock();
90 for (unsigned j = 0, M = DIELocs.size(); j < M; ++j)
91 DIELocs[j]->~DIELoc();
94 /// createDIEEntry - Creates a new DIEEntry to be a proxy for a debug
95 /// information entry.
96 DIEEntry *DwarfUnit::createDIEEntry(DIE &Entry) {
97 DIEEntry *Value = new (DIEValueAllocator) DIEEntry(Entry);
101 /// getDefaultLowerBound - Return the default lower bound for an array. If the
102 /// DWARF version doesn't handle the language, return -1.
103 int64_t DwarfUnit::getDefaultLowerBound() const {
104 switch (getLanguage()) {
108 case dwarf::DW_LANG_C89:
109 case dwarf::DW_LANG_C99:
110 case dwarf::DW_LANG_C:
111 case dwarf::DW_LANG_C_plus_plus:
112 case dwarf::DW_LANG_ObjC:
113 case dwarf::DW_LANG_ObjC_plus_plus:
116 case dwarf::DW_LANG_Fortran77:
117 case dwarf::DW_LANG_Fortran90:
118 case dwarf::DW_LANG_Fortran95:
121 // The languages below have valid values only if the DWARF version >= 4.
122 case dwarf::DW_LANG_Java:
123 case dwarf::DW_LANG_Python:
124 case dwarf::DW_LANG_UPC:
125 case dwarf::DW_LANG_D:
126 if (dwarf::DWARF_VERSION >= 4)
130 case dwarf::DW_LANG_Ada83:
131 case dwarf::DW_LANG_Ada95:
132 case dwarf::DW_LANG_Cobol74:
133 case dwarf::DW_LANG_Cobol85:
134 case dwarf::DW_LANG_Modula2:
135 case dwarf::DW_LANG_Pascal83:
136 case dwarf::DW_LANG_PLI:
137 if (dwarf::DWARF_VERSION >= 4)
141 // The languages below have valid values only if the DWARF version >= 5.
142 case dwarf::DW_LANG_OpenCL:
143 case dwarf::DW_LANG_Go:
144 case dwarf::DW_LANG_Haskell:
145 case dwarf::DW_LANG_C_plus_plus_03:
146 case dwarf::DW_LANG_C_plus_plus_11:
147 case dwarf::DW_LANG_OCaml:
148 case dwarf::DW_LANG_Rust:
149 case dwarf::DW_LANG_C11:
150 case dwarf::DW_LANG_Swift:
151 case dwarf::DW_LANG_Dylan:
152 case dwarf::DW_LANG_C_plus_plus_14:
153 if (dwarf::DWARF_VERSION >= 5)
157 case dwarf::DW_LANG_Modula3:
158 case dwarf::DW_LANG_Julia:
159 case dwarf::DW_LANG_Fortran03:
160 case dwarf::DW_LANG_Fortran08:
161 if (dwarf::DWARF_VERSION >= 5)
169 /// Check whether the DIE for this MDNode can be shared across CUs.
170 static bool isShareableAcrossCUs(DIDescriptor D) {
171 // When the MDNode can be part of the type system, the DIE can be shared
173 // Combining type units and cross-CU DIE sharing is lower value (since
174 // cross-CU DIE sharing is used in LTO and removes type redundancy at that
175 // level already) but may be implementable for some value in projects
176 // building multiple independent libraries with LTO and then linking those
178 return (isa<MDType>(D) ||
179 (isa<MDSubprogram>(D) && !cast<MDSubprogram>(D)->isDefinition())) &&
180 !GenerateDwarfTypeUnits;
183 /// getDIE - Returns the debug information entry map slot for the
184 /// specified debug variable. We delegate the request to DwarfDebug
185 /// when the DIE for this MDNode can be shared across CUs. The mappings
186 /// will be kept in DwarfDebug for shareable DIEs.
187 DIE *DwarfUnit::getDIE(DIDescriptor D) const {
188 if (isShareableAcrossCUs(D))
189 return DU->getDIE(D);
190 return MDNodeToDieMap.lookup(D);
193 /// insertDIE - Insert DIE into the map. We delegate the request to DwarfDebug
194 /// when the DIE for this MDNode can be shared across CUs. The mappings
195 /// will be kept in DwarfDebug for shareable DIEs.
196 void DwarfUnit::insertDIE(DIDescriptor Desc, DIE *D) {
197 if (isShareableAcrossCUs(Desc)) {
198 DU->insertDIE(Desc, D);
201 MDNodeToDieMap.insert(std::make_pair(Desc, D));
204 /// addFlag - Add a flag that is true.
205 void DwarfUnit::addFlag(DIE &Die, dwarf::Attribute Attribute) {
206 if (DD->getDwarfVersion() >= 4)
207 Die.addValue(Attribute, dwarf::DW_FORM_flag_present, DIEIntegerOne);
209 Die.addValue(Attribute, dwarf::DW_FORM_flag, DIEIntegerOne);
212 /// addUInt - Add an unsigned integer attribute data and value.
214 void DwarfUnit::addUInt(DIE &Die, dwarf::Attribute Attribute,
215 Optional<dwarf::Form> Form, uint64_t Integer) {
217 Form = DIEInteger::BestForm(false, Integer);
218 DIEValue *Value = Integer == 1 ? DIEIntegerOne : new (DIEValueAllocator)
220 Die.addValue(Attribute, *Form, Value);
223 void DwarfUnit::addUInt(DIE &Block, dwarf::Form Form, uint64_t Integer) {
224 addUInt(Block, (dwarf::Attribute)0, Form, Integer);
227 /// addSInt - Add an signed integer attribute data and value.
229 void DwarfUnit::addSInt(DIE &Die, dwarf::Attribute Attribute,
230 Optional<dwarf::Form> Form, int64_t Integer) {
232 Form = DIEInteger::BestForm(true, Integer);
233 DIEValue *Value = new (DIEValueAllocator) DIEInteger(Integer);
234 Die.addValue(Attribute, *Form, Value);
237 void DwarfUnit::addSInt(DIELoc &Die, Optional<dwarf::Form> Form,
239 addSInt(Die, (dwarf::Attribute)0, Form, Integer);
242 /// addString - Add a string attribute data and value. We always emit a
243 /// reference to the string pool instead of immediate strings so that DIEs have
244 /// more predictable sizes. In the case of split dwarf we emit an index
245 /// into another table which gets us the static offset into the string
247 void DwarfUnit::addString(DIE &Die, dwarf::Attribute Attribute,
250 return addLocalString(Die, Attribute, String);
252 addIndexedString(Die, Attribute, String);
255 void DwarfUnit::addIndexedString(DIE &Die, dwarf::Attribute Attribute,
257 unsigned idx = DU->getStringPool().getIndex(*Asm, String);
258 DIEValue *Value = new (DIEValueAllocator) DIEInteger(idx);
259 DIEValue *Str = new (DIEValueAllocator) DIEString(Value, String);
260 Die.addValue(Attribute, dwarf::DW_FORM_GNU_str_index, Str);
263 /// addLocalString - Add a string attribute data and value. This is guaranteed
264 /// to be in the local string pool instead of indirected.
265 void DwarfUnit::addLocalString(DIE &Die, dwarf::Attribute Attribute,
267 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
268 MCSymbol *Symb = DU->getStringPool().getSymbol(*Asm, String);
270 if (Asm->MAI->doesDwarfUseRelocationsAcrossSections())
271 Value = new (DIEValueAllocator) DIELabel(Symb);
273 Value = new (DIEValueAllocator)
274 DIEDelta(Symb, TLOF.getDwarfStrSection()->getBeginSymbol());
275 DIEValue *Str = new (DIEValueAllocator) DIEString(Value, String);
276 Die.addValue(Attribute, dwarf::DW_FORM_strp, Str);
279 /// addLabel - Add a Dwarf label attribute data and value.
281 void DwarfUnit::addLabel(DIE &Die, dwarf::Attribute Attribute, dwarf::Form Form,
282 const MCSymbol *Label) {
283 DIEValue *Value = new (DIEValueAllocator) DIELabel(Label);
284 Die.addValue(Attribute, Form, Value);
287 void DwarfUnit::addLabel(DIELoc &Die, dwarf::Form Form, const MCSymbol *Label) {
288 addLabel(Die, (dwarf::Attribute)0, Form, Label);
291 /// addSectionOffset - Add an offset into a section attribute data and value.
293 void DwarfUnit::addSectionOffset(DIE &Die, dwarf::Attribute Attribute,
295 if (DD->getDwarfVersion() >= 4)
296 addUInt(Die, Attribute, dwarf::DW_FORM_sec_offset, Integer);
298 addUInt(Die, Attribute, dwarf::DW_FORM_data4, Integer);
301 unsigned DwarfTypeUnit::getOrCreateSourceID(StringRef FileName, StringRef DirName) {
302 return SplitLineTable ? SplitLineTable->getFile(DirName, FileName)
303 : getCU().getOrCreateSourceID(FileName, DirName);
306 /// addOpAddress - Add a dwarf op address data and value using the
307 /// form given and an op of either DW_FORM_addr or DW_FORM_GNU_addr_index.
309 void DwarfUnit::addOpAddress(DIELoc &Die, const MCSymbol *Sym) {
310 if (!DD->useSplitDwarf()) {
311 addUInt(Die, dwarf::DW_FORM_data1, dwarf::DW_OP_addr);
312 addLabel(Die, dwarf::DW_FORM_udata, Sym);
314 addUInt(Die, dwarf::DW_FORM_data1, dwarf::DW_OP_GNU_addr_index);
315 addUInt(Die, dwarf::DW_FORM_GNU_addr_index,
316 DD->getAddressPool().getIndex(Sym));
320 void DwarfUnit::addLabelDelta(DIE &Die, dwarf::Attribute Attribute,
321 const MCSymbol *Hi, const MCSymbol *Lo) {
322 DIEValue *Value = new (DIEValueAllocator) DIEDelta(Hi, Lo);
323 Die.addValue(Attribute, dwarf::DW_FORM_data4, Value);
326 /// addDIEEntry - Add a DIE attribute data and value.
328 void DwarfUnit::addDIEEntry(DIE &Die, dwarf::Attribute Attribute, DIE &Entry) {
329 addDIEEntry(Die, Attribute, createDIEEntry(Entry));
332 void DwarfUnit::addDIETypeSignature(DIE &Die, const DwarfTypeUnit &Type) {
333 // Flag the type unit reference as a declaration so that if it contains
334 // members (implicit special members, static data member definitions, member
335 // declarations for definitions in this CU, etc) consumers don't get confused
336 // and think this is a full definition.
337 addFlag(Die, dwarf::DW_AT_declaration);
339 Die.addValue(dwarf::DW_AT_signature, dwarf::DW_FORM_ref_sig8,
340 new (DIEValueAllocator) DIETypeSignature(Type));
343 void DwarfUnit::addDIEEntry(DIE &Die, dwarf::Attribute Attribute,
345 const DIE *DieCU = Die.getUnitOrNull();
346 const DIE *EntryCU = Entry->getEntry().getUnitOrNull();
348 // We assume that Die belongs to this CU, if it is not linked to any CU yet.
349 DieCU = &getUnitDie();
351 EntryCU = &getUnitDie();
352 Die.addValue(Attribute,
353 EntryCU == DieCU ? dwarf::DW_FORM_ref4 : dwarf::DW_FORM_ref_addr,
357 /// Create a DIE with the given Tag, add the DIE to its parent, and
358 /// call insertDIE if MD is not null.
359 DIE &DwarfUnit::createAndAddDIE(unsigned Tag, DIE &Parent, DIDescriptor N) {
360 assert(Tag != dwarf::DW_TAG_auto_variable &&
361 Tag != dwarf::DW_TAG_arg_variable);
362 Parent.addChild(make_unique<DIE>((dwarf::Tag)Tag));
363 DIE &Die = *Parent.getChildren().back();
369 /// addBlock - Add block data.
371 void DwarfUnit::addBlock(DIE &Die, dwarf::Attribute Attribute, DIELoc *Loc) {
372 Loc->ComputeSize(Asm);
373 DIELocs.push_back(Loc); // Memoize so we can call the destructor later on.
374 Die.addValue(Attribute, Loc->BestForm(DD->getDwarfVersion()), Loc);
377 void DwarfUnit::addBlock(DIE &Die, dwarf::Attribute Attribute,
379 Block->ComputeSize(Asm);
380 DIEBlocks.push_back(Block); // Memoize so we can call the destructor later on.
381 Die.addValue(Attribute, Block->BestForm(), Block);
384 /// addSourceLine - Add location information to specified debug information
386 void DwarfUnit::addSourceLine(DIE &Die, unsigned Line, StringRef File,
387 StringRef Directory) {
391 unsigned FileID = getOrCreateSourceID(File, Directory);
392 assert(FileID && "Invalid file id");
393 addUInt(Die, dwarf::DW_AT_decl_file, None, FileID);
394 addUInt(Die, dwarf::DW_AT_decl_line, None, Line);
397 /// addSourceLine - Add location information to specified debug information
399 void DwarfUnit::addSourceLine(DIE &Die, DIVariable V) {
402 addSourceLine(Die, V->getLine(), V->getScope()->getFilename(),
403 V->getScope()->getDirectory());
406 /// addSourceLine - Add location information to specified debug information
408 void DwarfUnit::addSourceLine(DIE &Die, DIGlobalVariable G) {
411 addSourceLine(Die, G->getLine(), G->getFilename(), G->getDirectory());
414 /// addSourceLine - Add location information to specified debug information
416 void DwarfUnit::addSourceLine(DIE &Die, DISubprogram SP) {
419 addSourceLine(Die, SP->getLine(), SP->getFilename(), SP->getDirectory());
422 /// addSourceLine - Add location information to specified debug information
424 void DwarfUnit::addSourceLine(DIE &Die, DIType Ty) {
427 addSourceLine(Die, Ty->getLine(), Ty->getFilename(), Ty->getDirectory());
430 /// addSourceLine - Add location information to specified debug information
432 void DwarfUnit::addSourceLine(DIE &Die, DIObjCProperty Ty) {
435 addSourceLine(Die, Ty->getLine(), Ty->getFilename(), Ty->getDirectory());
438 /// addSourceLine - Add location information to specified debug information
440 void DwarfUnit::addSourceLine(DIE &Die, DINameSpace NS) {
441 addSourceLine(Die, NS->getLine(), NS->getFilename(), NS->getDirectory());
444 /// addRegisterOp - Add register operand.
445 bool DwarfUnit::addRegisterOpPiece(DIELoc &TheDie, unsigned Reg,
446 unsigned SizeInBits, unsigned OffsetInBits) {
447 DIEDwarfExpression Expr(*Asm, *this, TheDie);
448 Expr.AddMachineRegPiece(Reg, SizeInBits, OffsetInBits);
452 /// addRegisterOffset - Add register offset.
453 bool DwarfUnit::addRegisterOffset(DIELoc &TheDie, unsigned Reg,
455 DIEDwarfExpression Expr(*Asm, *this, TheDie);
456 return Expr.AddMachineRegIndirect(Reg, Offset);
459 /* Byref variables, in Blocks, are declared by the programmer as "SomeType
460 VarName;", but the compiler creates a __Block_byref_x_VarName struct, and
461 gives the variable VarName either the struct, or a pointer to the struct, as
462 its type. This is necessary for various behind-the-scenes things the
463 compiler needs to do with by-reference variables in Blocks.
465 However, as far as the original *programmer* is concerned, the variable
466 should still have type 'SomeType', as originally declared.
468 The function getBlockByrefType dives into the __Block_byref_x_VarName
469 struct to find the original type of the variable, which is then assigned to
470 the variable's Debug Information Entry as its real type. So far, so good.
471 However now the debugger will expect the variable VarName to have the type
472 SomeType. So we need the location attribute for the variable to be an
473 expression that explains to the debugger how to navigate through the
474 pointers and struct to find the actual variable of type SomeType.
476 The following function does just that. We start by getting
477 the "normal" location for the variable. This will be the location
478 of either the struct __Block_byref_x_VarName or the pointer to the
479 struct __Block_byref_x_VarName.
481 The struct will look something like:
483 struct __Block_byref_x_VarName {
485 struct __Block_byref_x_VarName *forwarding;
486 ... <various other fields>
488 ... <maybe more fields>
491 If we are given the struct directly (as our starting point) we
492 need to tell the debugger to:
494 1). Add the offset of the forwarding field.
496 2). Follow that pointer to get the real __Block_byref_x_VarName
497 struct to use (the real one may have been copied onto the heap).
499 3). Add the offset for the field VarName, to find the actual variable.
501 If we started with a pointer to the struct, then we need to
502 dereference that pointer first, before the other steps.
503 Translating this into DWARF ops, we will need to append the following
504 to the current location description for the variable:
506 DW_OP_deref -- optional, if we start with a pointer
507 DW_OP_plus_uconst <forward_fld_offset>
509 DW_OP_plus_uconst <varName_fld_offset>
511 That is what this function does. */
513 /// addBlockByrefAddress - Start with the address based on the location
514 /// provided, and generate the DWARF information necessary to find the
515 /// actual Block variable (navigating the Block struct) based on the
516 /// starting location. Add the DWARF information to the die. For
517 /// more information, read large comment just above here.
519 void DwarfUnit::addBlockByrefAddress(const DbgVariable &DV, DIE &Die,
520 dwarf::Attribute Attribute,
521 const MachineLocation &Location) {
522 DIType Ty = DV.getType();
524 uint16_t Tag = Ty->getTag();
525 bool isPointer = false;
527 StringRef varName = DV.getName();
529 if (Tag == dwarf::DW_TAG_pointer_type) {
530 DIDerivedType DTy = cast<MDDerivedType>(Ty);
531 TmpTy = resolve(DTy->getBaseType());
535 // Find the __forwarding field and the variable field in the __Block_byref
537 DIArray Fields = cast<MDCompositeTypeBase>(TmpTy)->getElements();
538 DIDerivedType varField;
539 DIDerivedType forwardingField;
541 for (unsigned i = 0, N = Fields.size(); i < N; ++i) {
542 DIDerivedType DT = cast<MDDerivedTypeBase>(Fields[i]);
543 StringRef fieldName = DT->getName();
544 if (fieldName == "__forwarding")
545 forwardingField = DT;
546 else if (fieldName == varName)
550 // Get the offsets for the forwarding field and the variable field.
551 unsigned forwardingFieldOffset = forwardingField->getOffsetInBits() >> 3;
552 unsigned varFieldOffset = varField->getOffsetInBits() >> 2;
554 // Decode the original location, and use that as the start of the byref
555 // variable's location.
556 DIELoc *Loc = new (DIEValueAllocator) DIELoc();
559 if (Location.isReg())
560 validReg = addRegisterOpPiece(*Loc, Location.getReg());
562 validReg = addRegisterOffset(*Loc, Location.getReg(), Location.getOffset());
567 // If we started with a pointer to the __Block_byref... struct, then
568 // the first thing we need to do is dereference the pointer (DW_OP_deref).
570 addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_deref);
572 // Next add the offset for the '__forwarding' field:
573 // DW_OP_plus_uconst ForwardingFieldOffset. Note there's no point in
574 // adding the offset if it's 0.
575 if (forwardingFieldOffset > 0) {
576 addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_plus_uconst);
577 addUInt(*Loc, dwarf::DW_FORM_udata, forwardingFieldOffset);
580 // Now dereference the __forwarding field to get to the real __Block_byref
581 // struct: DW_OP_deref.
582 addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_deref);
584 // Now that we've got the real __Block_byref... struct, add the offset
585 // for the variable's field to get to the location of the actual variable:
586 // DW_OP_plus_uconst varFieldOffset. Again, don't add if it's 0.
587 if (varFieldOffset > 0) {
588 addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_plus_uconst);
589 addUInt(*Loc, dwarf::DW_FORM_udata, varFieldOffset);
592 // Now attach the location information to the DIE.
593 addBlock(Die, Attribute, Loc);
596 /// Return true if type encoding is unsigned.
597 static bool isUnsignedDIType(DwarfDebug *DD, DIType Ty) {
598 if (DIDerivedType DTy = dyn_cast<MDDerivedTypeBase>(Ty)) {
599 dwarf::Tag T = (dwarf::Tag)Ty->getTag();
600 // Encode pointer constants as unsigned bytes. This is used at least for
601 // null pointer constant emission.
602 // (Pieces of) aggregate types that get hacked apart by SROA may also be
603 // represented by a constant. Encode them as unsigned bytes.
604 // FIXME: reference and rvalue_reference /probably/ shouldn't be allowed
605 // here, but accept them for now due to a bug in SROA producing bogus
607 if (T == dwarf::DW_TAG_array_type ||
608 T == dwarf::DW_TAG_class_type ||
609 T == dwarf::DW_TAG_pointer_type ||
610 T == dwarf::DW_TAG_ptr_to_member_type ||
611 T == dwarf::DW_TAG_reference_type ||
612 T == dwarf::DW_TAG_rvalue_reference_type ||
613 T == dwarf::DW_TAG_structure_type ||
614 T == dwarf::DW_TAG_union_type)
616 assert(T == dwarf::DW_TAG_typedef || T == dwarf::DW_TAG_const_type ||
617 T == dwarf::DW_TAG_volatile_type ||
618 T == dwarf::DW_TAG_restrict_type ||
619 T == dwarf::DW_TAG_enumeration_type);
620 if (DITypeRef Deriv = DTy->getBaseType())
621 return isUnsignedDIType(DD, DD->resolve(Deriv));
622 // FIXME: Enums without a fixed underlying type have unknown signedness
623 // here, leading to incorrectly emitted constants.
624 assert(DTy->getTag() == dwarf::DW_TAG_enumeration_type);
628 DIBasicType BTy = cast<MDBasicType>(Ty);
629 unsigned Encoding = BTy->getEncoding();
630 assert((Encoding == dwarf::DW_ATE_unsigned ||
631 Encoding == dwarf::DW_ATE_unsigned_char ||
632 Encoding == dwarf::DW_ATE_signed ||
633 Encoding == dwarf::DW_ATE_signed_char ||
634 Encoding == dwarf::DW_ATE_float || Encoding == dwarf::DW_ATE_UTF ||
635 Encoding == dwarf::DW_ATE_boolean ||
636 (Ty->getTag() == dwarf::DW_TAG_unspecified_type &&
637 Ty->getName() == "decltype(nullptr)")) &&
638 "Unsupported encoding");
639 return Encoding == dwarf::DW_ATE_unsigned ||
640 Encoding == dwarf::DW_ATE_unsigned_char ||
641 Encoding == dwarf::DW_ATE_UTF || Encoding == dwarf::DW_ATE_boolean ||
642 Ty->getTag() == dwarf::DW_TAG_unspecified_type;
645 /// If this type is derived from a base type then return base type size.
646 static uint64_t getBaseTypeSize(DwarfDebug *DD, DIDerivedType Ty) {
647 unsigned Tag = Ty->getTag();
649 if (Tag != dwarf::DW_TAG_member && Tag != dwarf::DW_TAG_typedef &&
650 Tag != dwarf::DW_TAG_const_type && Tag != dwarf::DW_TAG_volatile_type &&
651 Tag != dwarf::DW_TAG_restrict_type)
652 return Ty->getSizeInBits();
654 auto *BaseType = DD->resolve(Ty->getBaseType());
656 assert(BaseType && "Unexpected invalid base type");
658 // If this is a derived type, go ahead and get the base type, unless it's a
659 // reference then it's just the size of the field. Pointer types have no need
660 // of this since they're a different type of qualification on the type.
661 if (BaseType->getTag() == dwarf::DW_TAG_reference_type ||
662 BaseType->getTag() == dwarf::DW_TAG_rvalue_reference_type)
663 return Ty->getSizeInBits();
665 if (auto *DT = dyn_cast<MDDerivedTypeBase>(BaseType))
666 return getBaseTypeSize(DD, DT);
668 return BaseType->getSizeInBits();
671 /// addConstantFPValue - Add constant value entry in variable DIE.
672 void DwarfUnit::addConstantFPValue(DIE &Die, const MachineOperand &MO) {
673 assert(MO.isFPImm() && "Invalid machine operand!");
674 DIEBlock *Block = new (DIEValueAllocator) DIEBlock();
675 APFloat FPImm = MO.getFPImm()->getValueAPF();
677 // Get the raw data form of the floating point.
678 const APInt FltVal = FPImm.bitcastToAPInt();
679 const char *FltPtr = (const char *)FltVal.getRawData();
681 int NumBytes = FltVal.getBitWidth() / 8; // 8 bits per byte.
682 bool LittleEndian = Asm->getDataLayout().isLittleEndian();
683 int Incr = (LittleEndian ? 1 : -1);
684 int Start = (LittleEndian ? 0 : NumBytes - 1);
685 int Stop = (LittleEndian ? NumBytes : -1);
687 // Output the constant to DWARF one byte at a time.
688 for (; Start != Stop; Start += Incr)
689 addUInt(*Block, dwarf::DW_FORM_data1, (unsigned char)0xFF & FltPtr[Start]);
691 addBlock(Die, dwarf::DW_AT_const_value, Block);
694 /// addConstantFPValue - Add constant value entry in variable DIE.
695 void DwarfUnit::addConstantFPValue(DIE &Die, const ConstantFP *CFP) {
696 // Pass this down to addConstantValue as an unsigned bag of bits.
697 addConstantValue(Die, CFP->getValueAPF().bitcastToAPInt(), true);
700 /// addConstantValue - Add constant value entry in variable DIE.
701 void DwarfUnit::addConstantValue(DIE &Die, const ConstantInt *CI, DIType Ty) {
702 addConstantValue(Die, CI->getValue(), Ty);
705 /// addConstantValue - Add constant value entry in variable DIE.
706 void DwarfUnit::addConstantValue(DIE &Die, const MachineOperand &MO,
708 assert(MO.isImm() && "Invalid machine operand!");
710 addConstantValue(Die, isUnsignedDIType(DD, Ty), MO.getImm());
713 void DwarfUnit::addConstantValue(DIE &Die, bool Unsigned, uint64_t Val) {
714 // FIXME: This is a bit conservative/simple - it emits negative values always
715 // sign extended to 64 bits rather than minimizing the number of bytes.
716 addUInt(Die, dwarf::DW_AT_const_value,
717 Unsigned ? dwarf::DW_FORM_udata : dwarf::DW_FORM_sdata, Val);
720 void DwarfUnit::addConstantValue(DIE &Die, const APInt &Val, DIType Ty) {
721 addConstantValue(Die, Val, isUnsignedDIType(DD, Ty));
724 // addConstantValue - Add constant value entry in variable DIE.
725 void DwarfUnit::addConstantValue(DIE &Die, const APInt &Val, bool Unsigned) {
726 unsigned CIBitWidth = Val.getBitWidth();
727 if (CIBitWidth <= 64) {
728 addConstantValue(Die, Unsigned,
729 Unsigned ? Val.getZExtValue() : Val.getSExtValue());
733 DIEBlock *Block = new (DIEValueAllocator) DIEBlock();
735 // Get the raw data form of the large APInt.
736 const uint64_t *Ptr64 = Val.getRawData();
738 int NumBytes = Val.getBitWidth() / 8; // 8 bits per byte.
739 bool LittleEndian = Asm->getDataLayout().isLittleEndian();
741 // Output the constant to DWARF one byte at a time.
742 for (int i = 0; i < NumBytes; i++) {
745 c = Ptr64[i / 8] >> (8 * (i & 7));
747 c = Ptr64[(NumBytes - 1 - i) / 8] >> (8 * ((NumBytes - 1 - i) & 7));
748 addUInt(*Block, dwarf::DW_FORM_data1, c);
751 addBlock(Die, dwarf::DW_AT_const_value, Block);
754 // Add a linkage name to the DIE.
755 void DwarfUnit::addLinkageName(DIE &Die, StringRef LinkageName) {
756 if (!LinkageName.empty())
758 DD->getDwarfVersion() >= 4 ? dwarf::DW_AT_linkage_name
759 : dwarf::DW_AT_MIPS_linkage_name,
760 GlobalValue::getRealLinkageName(LinkageName));
763 /// addTemplateParams - Add template parameters into buffer.
764 void DwarfUnit::addTemplateParams(DIE &Buffer, DIArray TParams) {
765 // Add template parameters.
766 for (unsigned i = 0, e = TParams.size(); i != e; ++i) {
767 DIDescriptor Element = TParams[i];
768 if (auto *TTP = dyn_cast<MDTemplateTypeParameter>(Element))
769 constructTemplateTypeParameterDIE(Buffer, TTP);
770 else if (auto *TVP = dyn_cast<MDTemplateValueParameter>(Element))
771 constructTemplateValueParameterDIE(Buffer, TVP);
775 /// getOrCreateContextDIE - Get context owner's DIE.
776 DIE *DwarfUnit::getOrCreateContextDIE(DIScope Context) {
777 if (!Context || isa<MDFile>(Context))
778 return &getUnitDie();
779 if (auto *T = dyn_cast<MDType>(Context))
780 return getOrCreateTypeDIE(T);
781 if (auto *NS = dyn_cast<MDNamespace>(Context))
782 return getOrCreateNameSpace(NS);
783 if (auto *SP = dyn_cast<MDSubprogram>(Context))
784 return getOrCreateSubprogramDIE(SP);
785 return getDIE(Context);
788 DIE *DwarfUnit::createTypeDIE(DICompositeType Ty) {
789 DIScope Context = resolve(Ty->getScope());
790 DIE *ContextDIE = getOrCreateContextDIE(Context);
792 if (DIE *TyDIE = getDIE(Ty))
796 DIE &TyDIE = createAndAddDIE(Ty->getTag(), *ContextDIE, Ty);
798 constructTypeDIE(TyDIE, Ty);
800 updateAcceleratorTables(Context, Ty, TyDIE);
804 /// getOrCreateTypeDIE - Find existing DIE or create new DIE for the
806 DIE *DwarfUnit::getOrCreateTypeDIE(const MDNode *TyNode) {
810 auto *Ty = cast<MDType>(TyNode);
811 assert(Ty == resolve(Ty->getRef()) &&
812 "type was not uniqued, possible ODR violation.");
814 // DW_TAG_restrict_type is not supported in DWARF2
815 if (Ty->getTag() == dwarf::DW_TAG_restrict_type && DD->getDwarfVersion() <= 2)
816 return getOrCreateTypeDIE(
817 resolve(DITypeRef(cast<MDDerivedType>(Ty)->getBaseType())));
819 // Construct the context before querying for the existence of the DIE in case
820 // such construction creates the DIE.
821 DIScope Context = resolve(Ty->getScope());
822 DIE *ContextDIE = getOrCreateContextDIE(Context);
825 if (DIE *TyDIE = getDIE(Ty))
829 DIE &TyDIE = createAndAddDIE(Ty->getTag(), *ContextDIE, Ty);
831 updateAcceleratorTables(Context, Ty, TyDIE);
833 if (auto *BT = dyn_cast<MDBasicType>(Ty))
834 constructTypeDIE(TyDIE, BT);
835 else if (DICompositeType CTy = dyn_cast<MDCompositeTypeBase>(Ty)) {
836 if (GenerateDwarfTypeUnits && !Ty->isForwardDecl())
837 if (MDString *TypeId = CTy->getRawIdentifier()) {
838 DD->addDwarfTypeUnitType(getCU(), TypeId->getString(), TyDIE, CTy);
839 // Skip updating the accelerator tables since this is not the full type.
842 constructTypeDIE(TyDIE, CTy);
844 constructTypeDIE(TyDIE, cast<MDDerivedType>(Ty));
850 void DwarfUnit::updateAcceleratorTables(DIScope Context, DIType Ty,
852 if (!Ty->getName().empty() && !Ty->isForwardDecl()) {
853 bool IsImplementation = 0;
854 if (auto *CT = dyn_cast<MDCompositeTypeBase>(Ty)) {
855 // A runtime language of 0 actually means C/C++ and that any
856 // non-negative value is some version of Objective-C/C++.
857 IsImplementation = CT->getRuntimeLang() == 0 || CT->isObjcClassComplete();
859 unsigned Flags = IsImplementation ? dwarf::DW_FLAG_type_implementation : 0;
860 DD->addAccelType(Ty->getName(), TyDIE, Flags);
862 if (!Context || isa<MDCompileUnit>(Context) || isa<MDFile>(Context) ||
863 isa<MDNamespace>(Context))
864 addGlobalType(Ty, TyDIE, Context);
868 /// addType - Add a new type attribute to the specified entity.
869 void DwarfUnit::addType(DIE &Entity, DIType Ty, dwarf::Attribute Attribute) {
870 assert(Ty && "Trying to add a type that doesn't exist?");
872 // Check for pre-existence.
873 DIEEntry *Entry = getDIEEntry(Ty);
874 // If it exists then use the existing value.
876 addDIEEntry(Entity, Attribute, Entry);
881 DIE *Buffer = getOrCreateTypeDIE(Ty);
884 Entry = createDIEEntry(*Buffer);
885 insertDIEEntry(Ty, Entry);
886 addDIEEntry(Entity, Attribute, Entry);
889 /// getParentContextString - Walks the metadata parent chain in a language
890 /// specific manner (using the compile unit language) and returns
891 /// it as a string. This is done at the metadata level because DIEs may
892 /// not currently have been added to the parent context and walking the
893 /// DIEs looking for names is more expensive than walking the metadata.
894 std::string DwarfUnit::getParentContextString(DIScope Context) const {
898 // FIXME: Decide whether to implement this for non-C++ languages.
899 if (getLanguage() != dwarf::DW_LANG_C_plus_plus)
903 SmallVector<DIScope, 1> Parents;
904 while (!isa<MDCompileUnit>(Context)) {
905 Parents.push_back(Context);
906 if (Context->getScope())
907 Context = resolve(Context->getScope());
909 // Structure, etc types will have a NULL context if they're at the top
914 // Reverse iterate over our list to go from the outermost construct to the
916 for (SmallVectorImpl<DIScope>::reverse_iterator I = Parents.rbegin(),
919 const MDScope *Ctx = *I;
920 StringRef Name = Ctx->getName();
921 if (Name.empty() && isa<MDNamespace>(Ctx))
922 Name = "(anonymous namespace)";
931 /// constructTypeDIE - Construct basic type die from DIBasicType.
932 void DwarfUnit::constructTypeDIE(DIE &Buffer, DIBasicType BTy) {
933 // Get core information.
934 StringRef Name = BTy->getName();
935 // Add name if not anonymous or intermediate type.
937 addString(Buffer, dwarf::DW_AT_name, Name);
939 // An unspecified type only has a name attribute.
940 if (BTy->getTag() == dwarf::DW_TAG_unspecified_type)
943 addUInt(Buffer, dwarf::DW_AT_encoding, dwarf::DW_FORM_data1,
946 uint64_t Size = BTy->getSizeInBits() >> 3;
947 addUInt(Buffer, dwarf::DW_AT_byte_size, None, Size);
950 /// constructTypeDIE - Construct derived type die from DIDerivedType.
951 void DwarfUnit::constructTypeDIE(DIE &Buffer, DIDerivedType DTy) {
952 // Get core information.
953 StringRef Name = DTy->getName();
954 uint64_t Size = DTy->getSizeInBits() >> 3;
955 uint16_t Tag = Buffer.getTag();
957 // Map to main type, void will not have a type.
958 DIType FromTy = resolve(DTy->getBaseType());
960 addType(Buffer, FromTy);
962 // Add name if not anonymous or intermediate type.
964 addString(Buffer, dwarf::DW_AT_name, Name);
966 // Add size if non-zero (derived types might be zero-sized.)
967 if (Size && Tag != dwarf::DW_TAG_pointer_type
968 && Tag != dwarf::DW_TAG_ptr_to_member_type)
969 addUInt(Buffer, dwarf::DW_AT_byte_size, None, Size);
971 if (Tag == dwarf::DW_TAG_ptr_to_member_type)
973 Buffer, dwarf::DW_AT_containing_type,
974 *getOrCreateTypeDIE(resolve(cast<MDDerivedType>(DTy)->getClassType())));
975 // Add source line info if available and TyDesc is not a forward declaration.
976 if (!DTy->isForwardDecl())
977 addSourceLine(Buffer, DTy);
980 /// constructSubprogramArguments - Construct function argument DIEs.
981 void DwarfUnit::constructSubprogramArguments(DIE &Buffer, DITypeArray Args) {
982 for (unsigned i = 1, N = Args.size(); i < N; ++i) {
983 DIType Ty = resolve(Args[i]);
985 assert(i == N-1 && "Unspecified parameter must be the last argument");
986 createAndAddDIE(dwarf::DW_TAG_unspecified_parameters, Buffer);
988 DIE &Arg = createAndAddDIE(dwarf::DW_TAG_formal_parameter, Buffer);
990 if (Ty->isArtificial())
991 addFlag(Arg, dwarf::DW_AT_artificial);
996 /// constructTypeDIE - Construct type DIE from DICompositeType.
997 void DwarfUnit::constructTypeDIE(DIE &Buffer, DICompositeType CTy) {
998 // Add name if not anonymous or intermediate type.
999 StringRef Name = CTy->getName();
1001 uint64_t Size = CTy->getSizeInBits() >> 3;
1002 uint16_t Tag = Buffer.getTag();
1005 case dwarf::DW_TAG_array_type:
1006 constructArrayTypeDIE(Buffer, CTy);
1008 case dwarf::DW_TAG_enumeration_type:
1009 constructEnumTypeDIE(Buffer, CTy);
1011 case dwarf::DW_TAG_subroutine_type: {
1012 // Add return type. A void return won't have a type.
1013 auto Elements = cast<MDSubroutineType>(CTy)->getTypeArray();
1014 if (Elements.size())
1015 if (auto RTy = resolve(Elements[0]))
1016 addType(Buffer, RTy);
1018 bool isPrototyped = true;
1019 if (Elements.size() == 2 && !Elements[1])
1020 isPrototyped = false;
1022 constructSubprogramArguments(Buffer, Elements);
1024 // Add prototype flag if we're dealing with a C language and the
1025 // function has been prototyped.
1026 uint16_t Language = getLanguage();
1028 (Language == dwarf::DW_LANG_C89 || Language == dwarf::DW_LANG_C99 ||
1029 Language == dwarf::DW_LANG_ObjC))
1030 addFlag(Buffer, dwarf::DW_AT_prototyped);
1032 if (CTy->isLValueReference())
1033 addFlag(Buffer, dwarf::DW_AT_reference);
1035 if (CTy->isRValueReference())
1036 addFlag(Buffer, dwarf::DW_AT_rvalue_reference);
1038 case dwarf::DW_TAG_structure_type:
1039 case dwarf::DW_TAG_union_type:
1040 case dwarf::DW_TAG_class_type: {
1041 // Add elements to structure type.
1042 DIArray Elements = CTy->getElements();
1043 for (unsigned i = 0, N = Elements.size(); i < N; ++i) {
1044 DIDescriptor Element = Elements[i];
1047 if (auto *SP = dyn_cast<MDSubprogram>(Element))
1048 getOrCreateSubprogramDIE(SP);
1049 else if (DIDerivedType DDTy = dyn_cast<MDDerivedTypeBase>(Element)) {
1050 if (DDTy->getTag() == dwarf::DW_TAG_friend) {
1051 DIE &ElemDie = createAndAddDIE(dwarf::DW_TAG_friend, Buffer);
1052 addType(ElemDie, resolve(DDTy->getBaseType()), dwarf::DW_AT_friend);
1053 } else if (DDTy->isStaticMember()) {
1054 getOrCreateStaticMemberDIE(DDTy);
1056 constructMemberDIE(Buffer, DDTy);
1058 } else if (DIObjCProperty Property = dyn_cast<MDObjCProperty>(Element)) {
1059 DIE &ElemDie = createAndAddDIE(Property->getTag(), Buffer);
1060 StringRef PropertyName = Property->getName();
1061 addString(ElemDie, dwarf::DW_AT_APPLE_property_name, PropertyName);
1062 if (Property->getType())
1063 addType(ElemDie, Property->getType());
1064 addSourceLine(ElemDie, Property);
1065 StringRef GetterName = Property->getGetterName();
1066 if (!GetterName.empty())
1067 addString(ElemDie, dwarf::DW_AT_APPLE_property_getter, GetterName);
1068 StringRef SetterName = Property->getSetterName();
1069 if (!SetterName.empty())
1070 addString(ElemDie, dwarf::DW_AT_APPLE_property_setter, SetterName);
1071 if (unsigned PropertyAttributes = Property->getAttributes())
1072 addUInt(ElemDie, dwarf::DW_AT_APPLE_property_attribute, None,
1073 PropertyAttributes);
1075 DIEEntry *Entry = getDIEEntry(Element);
1077 Entry = createDIEEntry(ElemDie);
1078 insertDIEEntry(Element, Entry);
1083 if (CTy->isAppleBlockExtension())
1084 addFlag(Buffer, dwarf::DW_AT_APPLE_block);
1086 // This is outside the DWARF spec, but GDB expects a DW_AT_containing_type
1087 // inside C++ composite types to point to the base class with the vtable.
1088 if (DICompositeType ContainingType =
1089 dyn_cast_or_null<MDCompositeType>(resolve(CTy->getVTableHolder())))
1090 addDIEEntry(Buffer, dwarf::DW_AT_containing_type,
1091 *getOrCreateTypeDIE(ContainingType));
1093 if (CTy->isObjcClassComplete())
1094 addFlag(Buffer, dwarf::DW_AT_APPLE_objc_complete_type);
1096 // Add template parameters to a class, structure or union types.
1097 // FIXME: The support isn't in the metadata for this yet.
1098 if (Tag == dwarf::DW_TAG_class_type ||
1099 Tag == dwarf::DW_TAG_structure_type || Tag == dwarf::DW_TAG_union_type)
1100 addTemplateParams(Buffer, CTy->getTemplateParams());
1108 // Add name if not anonymous or intermediate type.
1110 addString(Buffer, dwarf::DW_AT_name, Name);
1112 if (Tag == dwarf::DW_TAG_enumeration_type ||
1113 Tag == dwarf::DW_TAG_class_type || Tag == dwarf::DW_TAG_structure_type ||
1114 Tag == dwarf::DW_TAG_union_type) {
1115 // Add size if non-zero (derived types might be zero-sized.)
1116 // TODO: Do we care about size for enum forward declarations?
1118 addUInt(Buffer, dwarf::DW_AT_byte_size, None, Size);
1119 else if (!CTy->isForwardDecl())
1120 // Add zero size if it is not a forward declaration.
1121 addUInt(Buffer, dwarf::DW_AT_byte_size, None, 0);
1123 // If we're a forward decl, say so.
1124 if (CTy->isForwardDecl())
1125 addFlag(Buffer, dwarf::DW_AT_declaration);
1127 // Add source line info if available.
1128 if (!CTy->isForwardDecl())
1129 addSourceLine(Buffer, CTy);
1131 // No harm in adding the runtime language to the declaration.
1132 unsigned RLang = CTy->getRuntimeLang();
1134 addUInt(Buffer, dwarf::DW_AT_APPLE_runtime_class, dwarf::DW_FORM_data1,
1139 /// constructTemplateTypeParameterDIE - Construct new DIE for the given
1140 /// DITemplateTypeParameter.
1141 void DwarfUnit::constructTemplateTypeParameterDIE(DIE &Buffer,
1142 DITemplateTypeParameter TP) {
1144 createAndAddDIE(dwarf::DW_TAG_template_type_parameter, Buffer);
1145 // Add the type if it exists, it could be void and therefore no type.
1147 addType(ParamDIE, resolve(TP->getType()));
1148 if (!TP->getName().empty())
1149 addString(ParamDIE, dwarf::DW_AT_name, TP->getName());
1152 /// constructTemplateValueParameterDIE - Construct new DIE for the given
1153 /// DITemplateValueParameter.
1155 DwarfUnit::constructTemplateValueParameterDIE(DIE &Buffer,
1156 DITemplateValueParameter VP) {
1157 DIE &ParamDIE = createAndAddDIE(VP->getTag(), Buffer);
1159 // Add the type if there is one, template template and template parameter
1160 // packs will not have a type.
1161 if (VP->getTag() == dwarf::DW_TAG_template_value_parameter)
1162 addType(ParamDIE, resolve(VP->getType()));
1163 if (!VP->getName().empty())
1164 addString(ParamDIE, dwarf::DW_AT_name, VP->getName());
1165 if (Metadata *Val = VP->getValue()) {
1166 if (ConstantInt *CI = mdconst::dyn_extract<ConstantInt>(Val))
1167 addConstantValue(ParamDIE, CI, resolve(VP->getType()));
1168 else if (GlobalValue *GV = mdconst::dyn_extract<GlobalValue>(Val)) {
1169 // For declaration non-type template parameters (such as global values and
1171 DIELoc *Loc = new (DIEValueAllocator) DIELoc();
1172 addOpAddress(*Loc, Asm->getSymbol(GV));
1173 // Emit DW_OP_stack_value to use the address as the immediate value of the
1174 // parameter, rather than a pointer to it.
1175 addUInt(*Loc, dwarf::DW_FORM_data1, dwarf::DW_OP_stack_value);
1176 addBlock(ParamDIE, dwarf::DW_AT_location, Loc);
1177 } else if (VP->getTag() == dwarf::DW_TAG_GNU_template_template_param) {
1178 assert(isa<MDString>(Val));
1179 addString(ParamDIE, dwarf::DW_AT_GNU_template_name,
1180 cast<MDString>(Val)->getString());
1181 } else if (VP->getTag() == dwarf::DW_TAG_GNU_template_parameter_pack) {
1182 addTemplateParams(ParamDIE, cast<MDTuple>(Val));
1187 /// getOrCreateNameSpace - Create a DIE for DINameSpace.
1188 DIE *DwarfUnit::getOrCreateNameSpace(DINameSpace NS) {
1189 // Construct the context before querying for the existence of the DIE in case
1190 // such construction creates the DIE.
1191 DIE *ContextDIE = getOrCreateContextDIE(NS->getScope());
1193 if (DIE *NDie = getDIE(NS))
1195 DIE &NDie = createAndAddDIE(dwarf::DW_TAG_namespace, *ContextDIE, NS);
1197 StringRef Name = NS->getName();
1199 addString(NDie, dwarf::DW_AT_name, NS->getName());
1201 Name = "(anonymous namespace)";
1202 DD->addAccelNamespace(Name, NDie);
1203 addGlobalName(Name, NDie, NS->getScope());
1204 addSourceLine(NDie, NS);
1208 /// getOrCreateSubprogramDIE - Create new DIE using SP.
1209 DIE *DwarfUnit::getOrCreateSubprogramDIE(DISubprogram SP, bool Minimal) {
1210 // Construct the context before querying for the existence of the DIE in case
1211 // such construction creates the DIE (as is the case for member function
1214 Minimal ? &getUnitDie() : getOrCreateContextDIE(resolve(SP->getScope()));
1216 if (DIE *SPDie = getDIE(SP))
1219 if (auto *SPDecl = SP->getDeclaration()) {
1221 // Add subprogram definitions to the CU die directly.
1222 ContextDIE = &getUnitDie();
1223 // Build the decl now to ensure it precedes the definition.
1224 getOrCreateSubprogramDIE(SPDecl);
1228 // DW_TAG_inlined_subroutine may refer to this DIE.
1229 DIE &SPDie = createAndAddDIE(dwarf::DW_TAG_subprogram, *ContextDIE, SP);
1231 // Stop here and fill this in later, depending on whether or not this
1232 // subprogram turns out to have inlined instances or not.
1233 if (SP->isDefinition())
1236 applySubprogramAttributes(SP, SPDie);
1240 bool DwarfUnit::applySubprogramDefinitionAttributes(DISubprogram SP,
1242 DIE *DeclDie = nullptr;
1243 StringRef DeclLinkageName;
1244 if (auto *SPDecl = SP->getDeclaration()) {
1245 DeclDie = getDIE(SPDecl);
1246 assert(DeclDie && "This DIE should've already been constructed when the "
1247 "definition DIE was created in "
1248 "getOrCreateSubprogramDIE");
1249 DeclLinkageName = SPDecl->getLinkageName();
1252 // Add function template parameters.
1253 addTemplateParams(SPDie, SP->getTemplateParams());
1255 // Add the linkage name if we have one and it isn't in the Decl.
1256 StringRef LinkageName = SP->getLinkageName();
1257 assert(((LinkageName.empty() || DeclLinkageName.empty()) ||
1258 LinkageName == DeclLinkageName) &&
1259 "decl has a linkage name and it is different");
1260 if (DeclLinkageName.empty())
1261 addLinkageName(SPDie, LinkageName);
1266 // Refer to the function declaration where all the other attributes will be
1268 addDIEEntry(SPDie, dwarf::DW_AT_specification, *DeclDie);
1272 void DwarfUnit::applySubprogramAttributes(DISubprogram SP, DIE &SPDie,
1275 if (applySubprogramDefinitionAttributes(SP, SPDie))
1278 // Constructors and operators for anonymous aggregates do not have names.
1279 if (!SP->getName().empty())
1280 addString(SPDie, dwarf::DW_AT_name, SP->getName());
1282 // Skip the rest of the attributes under -gmlt to save space.
1286 addSourceLine(SPDie, SP);
1288 // Add the prototype if we have a prototype and we have a C like
1290 uint16_t Language = getLanguage();
1291 if (SP->isPrototyped() &&
1292 (Language == dwarf::DW_LANG_C89 || Language == dwarf::DW_LANG_C99 ||
1293 Language == dwarf::DW_LANG_ObjC))
1294 addFlag(SPDie, dwarf::DW_AT_prototyped);
1296 DISubroutineType SPTy = SP->getType();
1297 assert(SPTy->getTag() == dwarf::DW_TAG_subroutine_type &&
1298 "the type of a subprogram should be a subroutine");
1300 auto Args = SPTy->getTypeArray();
1301 // Add a return type. If this is a type like a C/C++ void type we don't add a
1304 if (auto Ty = resolve(Args[0]))
1307 unsigned VK = SP->getVirtuality();
1309 addUInt(SPDie, dwarf::DW_AT_virtuality, dwarf::DW_FORM_data1, VK);
1310 DIELoc *Block = getDIELoc();
1311 addUInt(*Block, dwarf::DW_FORM_data1, dwarf::DW_OP_constu);
1312 addUInt(*Block, dwarf::DW_FORM_udata, SP->getVirtualIndex());
1313 addBlock(SPDie, dwarf::DW_AT_vtable_elem_location, Block);
1314 ContainingTypeMap.insert(
1315 std::make_pair(&SPDie, resolve(SP->getContainingType())));
1318 if (!SP->isDefinition()) {
1319 addFlag(SPDie, dwarf::DW_AT_declaration);
1321 // Add arguments. Do not add arguments for subprogram definition. They will
1322 // be handled while processing variables.
1323 constructSubprogramArguments(SPDie, Args);
1326 if (SP->isArtificial())
1327 addFlag(SPDie, dwarf::DW_AT_artificial);
1329 if (!SP->isLocalToUnit())
1330 addFlag(SPDie, dwarf::DW_AT_external);
1332 if (SP->isOptimized())
1333 addFlag(SPDie, dwarf::DW_AT_APPLE_optimized);
1335 if (unsigned isa = Asm->getISAEncoding())
1336 addUInt(SPDie, dwarf::DW_AT_APPLE_isa, dwarf::DW_FORM_flag, isa);
1338 if (SP->isLValueReference())
1339 addFlag(SPDie, dwarf::DW_AT_reference);
1341 if (SP->isRValueReference())
1342 addFlag(SPDie, dwarf::DW_AT_rvalue_reference);
1344 if (SP->isProtected())
1345 addUInt(SPDie, dwarf::DW_AT_accessibility, dwarf::DW_FORM_data1,
1346 dwarf::DW_ACCESS_protected);
1347 else if (SP->isPrivate())
1348 addUInt(SPDie, dwarf::DW_AT_accessibility, dwarf::DW_FORM_data1,
1349 dwarf::DW_ACCESS_private);
1350 else if (SP->isPublic())
1351 addUInt(SPDie, dwarf::DW_AT_accessibility, dwarf::DW_FORM_data1,
1352 dwarf::DW_ACCESS_public);
1354 if (SP->isExplicit())
1355 addFlag(SPDie, dwarf::DW_AT_explicit);
1358 /// constructSubrangeDIE - Construct subrange DIE from DISubrange.
1359 void DwarfUnit::constructSubrangeDIE(DIE &Buffer, DISubrange SR, DIE *IndexTy) {
1360 DIE &DW_Subrange = createAndAddDIE(dwarf::DW_TAG_subrange_type, Buffer);
1361 addDIEEntry(DW_Subrange, dwarf::DW_AT_type, *IndexTy);
1363 // The LowerBound value defines the lower bounds which is typically zero for
1364 // C/C++. The Count value is the number of elements. Values are 64 bit. If
1365 // Count == -1 then the array is unbounded and we do not emit
1366 // DW_AT_lower_bound and DW_AT_count attributes.
1367 int64_t LowerBound = SR->getLowerBound();
1368 int64_t DefaultLowerBound = getDefaultLowerBound();
1369 int64_t Count = SR->getCount();
1371 if (DefaultLowerBound == -1 || LowerBound != DefaultLowerBound)
1372 addUInt(DW_Subrange, dwarf::DW_AT_lower_bound, None, LowerBound);
1375 // FIXME: An unbounded array should reference the expression that defines
1377 addUInt(DW_Subrange, dwarf::DW_AT_count, None, Count);
1380 DIE *DwarfUnit::getIndexTyDie() {
1383 // Construct an integer type to use for indexes.
1384 IndexTyDie = &createAndAddDIE(dwarf::DW_TAG_base_type, UnitDie);
1385 addString(*IndexTyDie, dwarf::DW_AT_name, "sizetype");
1386 addUInt(*IndexTyDie, dwarf::DW_AT_byte_size, None, sizeof(int64_t));
1387 addUInt(*IndexTyDie, dwarf::DW_AT_encoding, dwarf::DW_FORM_data1,
1388 dwarf::DW_ATE_unsigned);
1392 /// constructArrayTypeDIE - Construct array type DIE from DICompositeType.
1393 void DwarfUnit::constructArrayTypeDIE(DIE &Buffer, DICompositeType CTy) {
1394 if (CTy->isVector())
1395 addFlag(Buffer, dwarf::DW_AT_GNU_vector);
1397 // Emit the element type.
1398 addType(Buffer, resolve(CTy->getBaseType()));
1400 // Get an anonymous type for index type.
1401 // FIXME: This type should be passed down from the front end
1402 // as different languages may have different sizes for indexes.
1403 DIE *IdxTy = getIndexTyDie();
1405 // Add subranges to array type.
1406 DIArray Elements = CTy->getElements();
1407 for (unsigned i = 0, N = Elements.size(); i < N; ++i) {
1408 // FIXME: Should this really be such a loose cast?
1409 if (auto *Element = dyn_cast_or_null<DebugNode>(Elements[i]))
1410 if (Element->getTag() == dwarf::DW_TAG_subrange_type)
1411 constructSubrangeDIE(Buffer, cast<MDSubrange>(Element), IdxTy);
1415 /// constructEnumTypeDIE - Construct an enum type DIE from DICompositeType.
1416 void DwarfUnit::constructEnumTypeDIE(DIE &Buffer, DICompositeType CTy) {
1417 DIArray Elements = CTy->getElements();
1419 // Add enumerators to enumeration type.
1420 for (unsigned i = 0, N = Elements.size(); i < N; ++i) {
1421 auto *Enum = dyn_cast_or_null<MDEnumerator>(Elements[i]);
1423 DIE &Enumerator = createAndAddDIE(dwarf::DW_TAG_enumerator, Buffer);
1424 StringRef Name = Enum->getName();
1425 addString(Enumerator, dwarf::DW_AT_name, Name);
1426 int64_t Value = Enum->getValue();
1427 addSInt(Enumerator, dwarf::DW_AT_const_value, dwarf::DW_FORM_sdata,
1431 DIType DTy = resolve(CTy->getBaseType());
1433 addType(Buffer, DTy);
1434 addFlag(Buffer, dwarf::DW_AT_enum_class);
1438 /// constructContainingTypeDIEs - Construct DIEs for types that contain
1440 void DwarfUnit::constructContainingTypeDIEs() {
1441 for (DenseMap<DIE *, const MDNode *>::iterator CI = ContainingTypeMap.begin(),
1442 CE = ContainingTypeMap.end();
1444 DIE &SPDie = *CI->first;
1445 DIDescriptor D(CI->second);
1448 DIE *NDie = getDIE(D);
1451 addDIEEntry(SPDie, dwarf::DW_AT_containing_type, *NDie);
1455 /// constructMemberDIE - Construct member DIE from DIDerivedType.
1456 void DwarfUnit::constructMemberDIE(DIE &Buffer, DIDerivedType DT_) {
1457 // Downcast to MDDerivedType.
1458 const MDDerivedType *DT = cast<MDDerivedType>(DT_);
1460 DIE &MemberDie = createAndAddDIE(DT->getTag(), Buffer);
1461 StringRef Name = DT->getName();
1463 addString(MemberDie, dwarf::DW_AT_name, Name);
1465 addType(MemberDie, resolve(DT->getBaseType()));
1467 addSourceLine(MemberDie, DT);
1469 if (DT->getTag() == dwarf::DW_TAG_inheritance && DT->isVirtual()) {
1471 // For C++, virtual base classes are not at fixed offset. Use following
1472 // expression to extract appropriate offset from vtable.
1473 // BaseAddr = ObAddr + *((*ObAddr) - Offset)
1475 DIELoc *VBaseLocationDie = new (DIEValueAllocator) DIELoc();
1476 addUInt(*VBaseLocationDie, dwarf::DW_FORM_data1, dwarf::DW_OP_dup);
1477 addUInt(*VBaseLocationDie, dwarf::DW_FORM_data1, dwarf::DW_OP_deref);
1478 addUInt(*VBaseLocationDie, dwarf::DW_FORM_data1, dwarf::DW_OP_constu);
1479 addUInt(*VBaseLocationDie, dwarf::DW_FORM_udata, DT->getOffsetInBits());
1480 addUInt(*VBaseLocationDie, dwarf::DW_FORM_data1, dwarf::DW_OP_minus);
1481 addUInt(*VBaseLocationDie, dwarf::DW_FORM_data1, dwarf::DW_OP_deref);
1482 addUInt(*VBaseLocationDie, dwarf::DW_FORM_data1, dwarf::DW_OP_plus);
1484 addBlock(MemberDie, dwarf::DW_AT_data_member_location, VBaseLocationDie);
1486 uint64_t Size = DT->getSizeInBits();
1487 uint64_t FieldSize = getBaseTypeSize(DD, DT);
1488 uint64_t OffsetInBytes;
1490 if (FieldSize && Size != FieldSize) {
1491 // Handle bitfield, assume bytes are 8 bits.
1492 addUInt(MemberDie, dwarf::DW_AT_byte_size, None, FieldSize/8);
1493 addUInt(MemberDie, dwarf::DW_AT_bit_size, None, Size);
1495 uint64_t Offset = DT->getOffsetInBits();
1496 uint64_t AlignMask = ~(DT->getAlignInBits() - 1);
1497 uint64_t HiMark = (Offset + FieldSize) & AlignMask;
1498 uint64_t FieldOffset = (HiMark - FieldSize);
1499 Offset -= FieldOffset;
1501 // Maybe we need to work from the other end.
1502 if (Asm->getDataLayout().isLittleEndian())
1503 Offset = FieldSize - (Offset + Size);
1504 addUInt(MemberDie, dwarf::DW_AT_bit_offset, None, Offset);
1506 // Here DW_AT_data_member_location points to the anonymous
1507 // field that includes this bit field.
1508 OffsetInBytes = FieldOffset >> 3;
1510 // This is not a bitfield.
1511 OffsetInBytes = DT->getOffsetInBits() >> 3;
1513 if (DD->getDwarfVersion() <= 2) {
1514 DIELoc *MemLocationDie = new (DIEValueAllocator) DIELoc();
1515 addUInt(*MemLocationDie, dwarf::DW_FORM_data1, dwarf::DW_OP_plus_uconst);
1516 addUInt(*MemLocationDie, dwarf::DW_FORM_udata, OffsetInBytes);
1517 addBlock(MemberDie, dwarf::DW_AT_data_member_location, MemLocationDie);
1519 addUInt(MemberDie, dwarf::DW_AT_data_member_location, None,
1523 if (DT->isProtected())
1524 addUInt(MemberDie, dwarf::DW_AT_accessibility, dwarf::DW_FORM_data1,
1525 dwarf::DW_ACCESS_protected);
1526 else if (DT->isPrivate())
1527 addUInt(MemberDie, dwarf::DW_AT_accessibility, dwarf::DW_FORM_data1,
1528 dwarf::DW_ACCESS_private);
1529 // Otherwise C++ member and base classes are considered public.
1530 else if (DT->isPublic())
1531 addUInt(MemberDie, dwarf::DW_AT_accessibility, dwarf::DW_FORM_data1,
1532 dwarf::DW_ACCESS_public);
1533 if (DT->isVirtual())
1534 addUInt(MemberDie, dwarf::DW_AT_virtuality, dwarf::DW_FORM_data1,
1535 dwarf::DW_VIRTUALITY_virtual);
1537 // Objective-C properties.
1538 if (MDNode *PNode = DT->getObjCProperty())
1539 if (DIEEntry *PropertyDie = getDIEEntry(PNode))
1540 MemberDie.addValue(dwarf::DW_AT_APPLE_property, dwarf::DW_FORM_ref4,
1543 if (DT->isArtificial())
1544 addFlag(MemberDie, dwarf::DW_AT_artificial);
1547 /// getOrCreateStaticMemberDIE - Create new DIE for C++ static member.
1548 DIE *DwarfUnit::getOrCreateStaticMemberDIE(DIDerivedType DT_) {
1549 const MDDerivedType *DT = cast_or_null<MDDerivedType>(DT_);
1553 // Construct the context before querying for the existence of the DIE in case
1554 // such construction creates the DIE.
1555 DIE *ContextDIE = getOrCreateContextDIE(resolve(DT->getScope()));
1556 assert(dwarf::isType(ContextDIE->getTag()) &&
1557 "Static member should belong to a type.");
1559 if (DIE *StaticMemberDIE = getDIE(DT))
1560 return StaticMemberDIE;
1562 DIE &StaticMemberDIE = createAndAddDIE(DT->getTag(), *ContextDIE, DT);
1564 DIType Ty = resolve(DT->getBaseType());
1566 addString(StaticMemberDIE, dwarf::DW_AT_name, DT->getName());
1567 addType(StaticMemberDIE, Ty);
1568 addSourceLine(StaticMemberDIE, DT);
1569 addFlag(StaticMemberDIE, dwarf::DW_AT_external);
1570 addFlag(StaticMemberDIE, dwarf::DW_AT_declaration);
1572 // FIXME: We could omit private if the parent is a class_type, and
1573 // public if the parent is something else.
1574 if (DT->isProtected())
1575 addUInt(StaticMemberDIE, dwarf::DW_AT_accessibility, dwarf::DW_FORM_data1,
1576 dwarf::DW_ACCESS_protected);
1577 else if (DT->isPrivate())
1578 addUInt(StaticMemberDIE, dwarf::DW_AT_accessibility, dwarf::DW_FORM_data1,
1579 dwarf::DW_ACCESS_private);
1580 else if (DT->isPublic())
1581 addUInt(StaticMemberDIE, dwarf::DW_AT_accessibility, dwarf::DW_FORM_data1,
1582 dwarf::DW_ACCESS_public);
1584 if (const ConstantInt *CI = dyn_cast_or_null<ConstantInt>(DT->getConstant()))
1585 addConstantValue(StaticMemberDIE, CI, Ty);
1586 if (const ConstantFP *CFP = dyn_cast_or_null<ConstantFP>(DT->getConstant()))
1587 addConstantFPValue(StaticMemberDIE, CFP);
1589 return &StaticMemberDIE;
1592 void DwarfUnit::emitHeader(bool UseOffsets) {
1593 // Emit size of content not including length itself
1594 Asm->OutStreamer.AddComment("Length of Unit");
1595 Asm->EmitInt32(getHeaderSize() + UnitDie.getSize());
1597 Asm->OutStreamer.AddComment("DWARF version number");
1598 Asm->EmitInt16(DD->getDwarfVersion());
1599 Asm->OutStreamer.AddComment("Offset Into Abbrev. Section");
1601 // We share one abbreviations table across all units so it's always at the
1602 // start of the section. Use a relocatable offset where needed to ensure
1603 // linking doesn't invalidate that offset.
1604 const TargetLoweringObjectFile &TLOF = Asm->getObjFileLowering();
1606 Asm->emitSectionOffset(TLOF.getDwarfAbbrevSection()->getBeginSymbol());
1610 Asm->OutStreamer.AddComment("Address Size (in bytes)");
1611 Asm->EmitInt8(Asm->getDataLayout().getPointerSize());
1614 void DwarfUnit::initSection(const MCSection *Section) {
1615 assert(!this->Section);
1616 this->Section = Section;
1619 void DwarfTypeUnit::emitHeader(bool UseOffsets) {
1620 DwarfUnit::emitHeader(UseOffsets);
1621 Asm->OutStreamer.AddComment("Type Signature");
1622 Asm->OutStreamer.EmitIntValue(TypeSignature, sizeof(TypeSignature));
1623 Asm->OutStreamer.AddComment("Type DIE Offset");
1624 // In a skeleton type unit there is no type DIE so emit a zero offset.
1625 Asm->OutStreamer.EmitIntValue(Ty ? Ty->getOffset() : 0,
1626 sizeof(Ty->getOffset()));
1629 bool DwarfTypeUnit::isDwoUnit() const {
1630 // Since there are no skeleton type units, all type units are dwo type units
1631 // when split DWARF is being used.
1632 return DD->useSplitDwarf();