1 //===--- lib/CodeGen/DIE.cpp - DWARF Info Entries -------------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // Data structures for DWARF info entries.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "llvm/CodeGen/DIE.h"
15 #include "DwarfCompileUnit.h"
16 #include "DwarfDebug.h"
17 #include "DwarfUnit.h"
18 #include "llvm/ADT/Twine.h"
19 #include "llvm/CodeGen/AsmPrinter.h"
20 #include "llvm/IR/DataLayout.h"
21 #include "llvm/MC/MCAsmInfo.h"
22 #include "llvm/MC/MCContext.h"
23 #include "llvm/MC/MCStreamer.h"
24 #include "llvm/MC/MCSymbol.h"
25 #include "llvm/Support/Debug.h"
26 #include "llvm/Support/ErrorHandling.h"
27 #include "llvm/Support/Format.h"
28 #include "llvm/Support/FormattedStream.h"
29 #include "llvm/Support/LEB128.h"
30 #include "llvm/Support/MD5.h"
31 #include "llvm/Support/raw_ostream.h"
32 using namespace llvm;
33 
34 #define DEBUG_TYPE "dwarfdebug"
35 
36 //===----------------------------------------------------------------------===//
37 // DIEAbbrevData Implementation
38 //===----------------------------------------------------------------------===//
39 
40 /// Profile - Used to gather unique data for the abbreviation folding set.
41 ///
42 void DIEAbbrevData::Profile(FoldingSetNodeID &ID) const {
43   // Explicitly cast to an integer type for which FoldingSetNodeID has
44   // overloads.  Otherwise MSVC 2010 thinks this call is ambiguous.
45   ID.AddInteger(unsigned(Attribute));
46   ID.AddInteger(unsigned(Form));
47   if (Form == dwarf::DW_FORM_implicit_const)
48     ID.AddInteger(Value);
49 }
50 
51 //===----------------------------------------------------------------------===//
52 // DIEAbbrev Implementation
53 //===----------------------------------------------------------------------===//
54 
55 /// Profile - Used to gather unique data for the abbreviation folding set.
56 ///
57 void DIEAbbrev::Profile(FoldingSetNodeID &ID) const {
58   ID.AddInteger(unsigned(Tag));
59   ID.AddInteger(unsigned(Children));
60 
61   // For each attribute description.
62   for (unsigned i = 0, N = Data.size(); i < N; ++i)
63     Data[i].Profile(ID);
64 }
65 
66 /// Emit - Print the abbreviation using the specified asm printer.
67 ///
68 void DIEAbbrev::Emit(const AsmPrinter *AP) const {
69   // Emit its Dwarf tag type.
70   AP->EmitULEB128(Tag, dwarf::TagString(Tag).data());
71 
72   // Emit whether it has children DIEs.
73   AP->EmitULEB128((unsigned)Children, dwarf::ChildrenString(Children).data());
74 
75   // For each attribute description.
76   for (unsigned i = 0, N = Data.size(); i < N; ++i) {
77     const DIEAbbrevData &AttrData = Data[i];
78 
79     // Emit attribute type.
80     AP->EmitULEB128(AttrData.getAttribute(),
81                     dwarf::AttributeString(AttrData.getAttribute()).data());
82 
83     // Emit form type.
84 #ifndef NDEBUG
85     // Could be an assertion, but this way we can see the failing form code
86     // easily, which helps track down where it came from.
87     if (!dwarf::isValidFormForVersion(AttrData.getForm(),
88                                       AP->getDwarfVersion())) {
89       DEBUG(dbgs() << "Invalid form " << format("0x%x", AttrData.getForm())
90                    << " for DWARF version " << AP->getDwarfVersion() << "\n");
91       llvm_unreachable("Invalid form for specified DWARF version");
92     }
93 #endif
94     AP->EmitULEB128(AttrData.getForm(),
95                     dwarf::FormEncodingString(AttrData.getForm()).data());
96 
97     // Emit value for DW_FORM_implicit_const.
98     if (AttrData.getForm() == dwarf::DW_FORM_implicit_const)
99       AP->EmitSLEB128(AttrData.getValue());
100   }
101 
102   // Mark end of abbreviation.
103   AP->EmitULEB128(0, "EOM(1)");
104   AP->EmitULEB128(0, "EOM(2)");
105 }
106 
107 LLVM_DUMP_METHOD
108 void DIEAbbrev::print(raw_ostream &O) const {
109   O << "Abbreviation @"
110     << format("0x%lx", (long)(intptr_t)this)
111     << "  "
112     << dwarf::TagString(Tag)
113     << " "
114     << dwarf::ChildrenString(Children)
115     << '\n';
116 
117   for (unsigned i = 0, N = Data.size(); i < N; ++i) {
118     O << "  "
119       << dwarf::AttributeString(Data[i].getAttribute())
120       << "  "
121       << dwarf::FormEncodingString(Data[i].getForm());
122 
123     if (Data[i].getForm() == dwarf::DW_FORM_implicit_const)
124       O << " " << Data[i].getValue();
125 
126     O << '\n';
127   }
128 }
129 
130 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
131 LLVM_DUMP_METHOD void DIEAbbrev::dump() const {
132   print(dbgs());
133 }
134 #endif
135 
136 //===----------------------------------------------------------------------===//
137 // DIEAbbrevSet Implementation
138 //===----------------------------------------------------------------------===//
139 
140 DIEAbbrevSet::~DIEAbbrevSet() {
141   for (DIEAbbrev *Abbrev : Abbreviations)
142     Abbrev->~DIEAbbrev();
143 }
144 
145 DIEAbbrev &DIEAbbrevSet::uniqueAbbreviation(DIE &Die) {
146 
147   FoldingSetNodeID ID;
148   DIEAbbrev Abbrev = Die.generateAbbrev();
149   Abbrev.Profile(ID);
150 
151   void *InsertPos;
152   if (DIEAbbrev *Existing =
153           AbbreviationsSet.FindNodeOrInsertPos(ID, InsertPos)) {
154     Die.setAbbrevNumber(Existing->getNumber());
155     return *Existing;
156   }
157 
158   // Move the abbreviation to the heap and assign a number.
159   DIEAbbrev *New = new (Alloc) DIEAbbrev(std::move(Abbrev));
160   Abbreviations.push_back(New);
161   New->setNumber(Abbreviations.size());
162   Die.setAbbrevNumber(Abbreviations.size());
163 
164   // Store it for lookup.
165   AbbreviationsSet.InsertNode(New, InsertPos);
166   return *New;
167 }
168 
169 void DIEAbbrevSet::Emit(const AsmPrinter *AP, MCSection *Section) const {
170   if (!Abbreviations.empty()) {
171     // Start the debug abbrev section.
172     AP->OutStreamer->SwitchSection(Section);
173     AP->emitDwarfAbbrevs(Abbreviations);
174   }
175 }
176 
177 //===----------------------------------------------------------------------===//
178 // DIE Implementation
179 //===----------------------------------------------------------------------===//
180 
181 DIE *DIE::getParent() const {
182   return Owner.dyn_cast<DIE*>();
183 }
184 
185 DIEAbbrev DIE::generateAbbrev() const {
186   DIEAbbrev Abbrev(Tag, hasChildren());
187   for (const DIEValue &V : values())
188     if (V.getForm() == dwarf::DW_FORM_implicit_const)
189       Abbrev.AddImplicitConstAttribute(V.getAttribute(),
190                                        V.getDIEInteger().getValue());
191     else
192       Abbrev.AddAttribute(V.getAttribute(), V.getForm());
193   return Abbrev;
194 }
195 
196 unsigned DIE::getDebugSectionOffset() const {
197   const DIEUnit *Unit = getUnit();
198   assert(Unit && "DIE must be owned by a DIEUnit to get its absolute offset");
199   return Unit->getDebugSectionOffset() + getOffset();
200 }
201 
202 const DIE *DIE::getUnitDie() const {
203   const DIE *p = this;
204   while (p) {
205     if (p->getTag() == dwarf::DW_TAG_compile_unit ||
206         p->getTag() == dwarf::DW_TAG_type_unit)
207       return p;
208     p = p->getParent();
209   }
210   return nullptr;
211 }
212 
213 const DIEUnit *DIE::getUnit() const {
214   const DIE *UnitDie = getUnitDie();
215   if (UnitDie)
216     return UnitDie->Owner.dyn_cast<DIEUnit*>();
217   return nullptr;
218 }
219 
220 DIEValue DIE::findAttribute(dwarf::Attribute Attribute) const {
221   // Iterate through all the attributes until we find the one we're
222   // looking for, if we can't find it return NULL.
223   for (const auto &V : values())
224     if (V.getAttribute() == Attribute)
225       return V;
226   return DIEValue();
227 }
228 
229 LLVM_DUMP_METHOD
230 static void printValues(raw_ostream &O, const DIEValueList &Values,
231                         StringRef Type, unsigned Size, unsigned IndentCount) {
232   O << Type << ": Size: " << Size << "\n";
233 
234   unsigned I = 0;
235   const std::string Indent(IndentCount, ' ');
236   for (const auto &V : Values.values()) {
237     O << Indent;
238     O << "Blk[" << I++ << "]";
239     O << "  " << dwarf::FormEncodingString(V.getForm()) << " ";
240     V.print(O);
241     O << "\n";
242   }
243 }
244 
245 LLVM_DUMP_METHOD
246 void DIE::print(raw_ostream &O, unsigned IndentCount) const {
247   const std::string Indent(IndentCount, ' ');
248   O << Indent << "Die: " << format("0x%lx", (long)(intptr_t) this)
249     << ", Offset: " << Offset << ", Size: " << Size << "\n";
250 
251   O << Indent << dwarf::TagString(getTag()) << " "
252     << dwarf::ChildrenString(hasChildren()) << "\n";
253 
254   IndentCount += 2;
255   for (const auto &V : values()) {
256     O << Indent;
257     O << dwarf::AttributeString(V.getAttribute());
258     O << "  " << dwarf::FormEncodingString(V.getForm()) << " ";
259     V.print(O);
260     O << "\n";
261   }
262   IndentCount -= 2;
263 
264   for (const auto &Child : children())
265     Child.print(O, IndentCount + 4);
266 
267   O << "\n";
268 }
269 
270 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
271 LLVM_DUMP_METHOD void DIE::dump() const {
272   print(dbgs());
273 }
274 #endif
275 
276 unsigned DIE::computeOffsetsAndAbbrevs(const AsmPrinter *AP,
277                                        DIEAbbrevSet &AbbrevSet,
278                                        unsigned CUOffset) {
279   // Unique the abbreviation and fill in the abbreviation number so this DIE
280   // can be emitted.
281   const DIEAbbrev &Abbrev = AbbrevSet.uniqueAbbreviation(*this);
282 
283   // Set compile/type unit relative offset of this DIE.
284   setOffset(CUOffset);
285 
286   // Add the byte size of the abbreviation code.
287   CUOffset += getULEB128Size(getAbbrevNumber());
288 
289   // Add the byte size of all the DIE attribute values.
290   for (const auto &V : values())
291     CUOffset += V.SizeOf(AP);
292 
293   // Let the children compute their offsets and abbreviation numbers.
294   if (hasChildren()) {
295     (void)Abbrev;
296     assert(Abbrev.hasChildren() && "Children flag not set");
297 
298     for (auto &Child : children())
299       CUOffset = Child.computeOffsetsAndAbbrevs(AP, AbbrevSet, CUOffset);
300 
301     // Each child chain is terminated with a zero byte, adjust the offset.
302     CUOffset += sizeof(int8_t);
303   }
304 
305   // Compute the byte size of this DIE and all of its children correctly. This
306   // is needed so that top level DIE can help the compile unit set its length
307   // correctly.
308   setSize(CUOffset - getOffset());
309   return CUOffset;
310 }
311 
312 //===----------------------------------------------------------------------===//
313 // DIEUnit Implementation
314 //===----------------------------------------------------------------------===//
315 DIEUnit::DIEUnit(uint16_t V, uint8_t A, dwarf::Tag UnitTag)
316     : Die(UnitTag), Section(nullptr), Offset(0), Length(0), Version(V),
317       AddrSize(A)
318 {
319   Die.Owner = this;
320   assert((UnitTag == dwarf::DW_TAG_compile_unit ||
321           UnitTag == dwarf::DW_TAG_type_unit ||
322           UnitTag == dwarf::DW_TAG_partial_unit) && "expected a unit TAG");
323 }
324 
325 void DIEValue::EmitValue(const AsmPrinter *AP) const {
326   switch (Ty) {
327   case isNone:
328     llvm_unreachable("Expected valid DIEValue");
329 #define HANDLE_DIEVALUE(T)                                                     \
330   case is##T:                                                                  \
331     getDIE##T().EmitValue(AP, Form);                                           \
332     break;
333 #include "llvm/CodeGen/DIEValue.def"
334   }
335 }
336 
337 unsigned DIEValue::SizeOf(const AsmPrinter *AP) const {
338   switch (Ty) {
339   case isNone:
340     llvm_unreachable("Expected valid DIEValue");
341 #define HANDLE_DIEVALUE(T)                                                     \
342   case is##T:                                                                  \
343     return getDIE##T().SizeOf(AP, Form);
344 #include "llvm/CodeGen/DIEValue.def"
345   }
346   llvm_unreachable("Unknown DIE kind");
347 }
348 
349 LLVM_DUMP_METHOD
350 void DIEValue::print(raw_ostream &O) const {
351   switch (Ty) {
352   case isNone:
353     llvm_unreachable("Expected valid DIEValue");
354 #define HANDLE_DIEVALUE(T)                                                     \
355   case is##T:                                                                  \
356     getDIE##T().print(O);                                                      \
357     break;
358 #include "llvm/CodeGen/DIEValue.def"
359   }
360 }
361 
362 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
363 LLVM_DUMP_METHOD void DIEValue::dump() const {
364   print(dbgs());
365 }
366 #endif
367 
368 //===----------------------------------------------------------------------===//
369 // DIEInteger Implementation
370 //===----------------------------------------------------------------------===//
371 
372 /// EmitValue - Emit integer of appropriate size.
373 ///
374 void DIEInteger::EmitValue(const AsmPrinter *Asm, dwarf::Form Form) const {
375   switch (Form) {
376   case dwarf::DW_FORM_implicit_const:
377   case dwarf::DW_FORM_flag_present:
378     // Emit something to keep the lines and comments in sync.
379     // FIXME: Is there a better way to do this?
380     Asm->OutStreamer->AddBlankLine();
381     return;
382   case dwarf::DW_FORM_flag:
383   case dwarf::DW_FORM_ref1:
384   case dwarf::DW_FORM_data1:
385   case dwarf::DW_FORM_strx1:
386   case dwarf::DW_FORM_addrx1:
387   case dwarf::DW_FORM_ref2:
388   case dwarf::DW_FORM_data2:
389   case dwarf::DW_FORM_strx2:
390   case dwarf::DW_FORM_addrx2:
391   case dwarf::DW_FORM_strx3:
392   case dwarf::DW_FORM_strp:
393   case dwarf::DW_FORM_ref4:
394   case dwarf::DW_FORM_data4:
395   case dwarf::DW_FORM_ref_sup4:
396   case dwarf::DW_FORM_strx4:
397   case dwarf::DW_FORM_addrx4:
398   case dwarf::DW_FORM_ref8:
399   case dwarf::DW_FORM_ref_sig8:
400   case dwarf::DW_FORM_data8:
401   case dwarf::DW_FORM_ref_sup8:
402   case dwarf::DW_FORM_GNU_ref_alt:
403   case dwarf::DW_FORM_GNU_strp_alt:
404   case dwarf::DW_FORM_line_strp:
405   case dwarf::DW_FORM_sec_offset:
406   case dwarf::DW_FORM_strp_sup:
407   case dwarf::DW_FORM_addr:
408   case dwarf::DW_FORM_ref_addr:
409     Asm->OutStreamer->EmitIntValue(Integer, SizeOf(Asm, Form));
410     return;
411   case dwarf::DW_FORM_GNU_str_index:
412   case dwarf::DW_FORM_GNU_addr_index:
413   case dwarf::DW_FORM_ref_udata:
414   case dwarf::DW_FORM_strx:
415   case dwarf::DW_FORM_udata:
416     Asm->EmitULEB128(Integer);
417     return;
418   case dwarf::DW_FORM_sdata:
419     Asm->EmitSLEB128(Integer);
420     return;
421   default: llvm_unreachable("DIE Value form not supported yet");
422   }
423 }
424 
425 /// SizeOf - Determine size of integer value in bytes.
426 ///
427 unsigned DIEInteger::SizeOf(const AsmPrinter *AP, dwarf::Form Form) const {
428   switch (Form) {
429   case dwarf::DW_FORM_implicit_const:
430   case dwarf::DW_FORM_flag_present:
431     return 0;
432   case dwarf::DW_FORM_flag:
433   case dwarf::DW_FORM_ref1:
434   case dwarf::DW_FORM_data1:
435   case dwarf::DW_FORM_strx1:
436   case dwarf::DW_FORM_addrx1:
437     return sizeof(int8_t);
438   case dwarf::DW_FORM_ref2:
439   case dwarf::DW_FORM_data2:
440   case dwarf::DW_FORM_strx2:
441   case dwarf::DW_FORM_addrx2:
442     return sizeof(int16_t);
443   case dwarf::DW_FORM_strx3:
444     return 3;
445   case dwarf::DW_FORM_ref4:
446   case dwarf::DW_FORM_data4:
447   case dwarf::DW_FORM_ref_sup4:
448   case dwarf::DW_FORM_strx4:
449   case dwarf::DW_FORM_addrx4:
450     return sizeof(int32_t);
451   case dwarf::DW_FORM_ref8:
452   case dwarf::DW_FORM_ref_sig8:
453   case dwarf::DW_FORM_data8:
454   case dwarf::DW_FORM_ref_sup8:
455     return sizeof(int64_t);
456   case dwarf::DW_FORM_ref_addr:
457     if (AP->getDwarfVersion() == 2)
458       return AP->getPointerSize();
459     LLVM_FALLTHROUGH;
460   case dwarf::DW_FORM_strp:
461   case dwarf::DW_FORM_GNU_ref_alt:
462   case dwarf::DW_FORM_GNU_strp_alt:
463   case dwarf::DW_FORM_line_strp:
464   case dwarf::DW_FORM_sec_offset:
465   case dwarf::DW_FORM_strp_sup:
466     switch (AP->OutStreamer->getContext().getDwarfFormat()) {
467     case dwarf::DWARF32:
468       return 4;
469     case dwarf::DWARF64:
470       return 8;
471     }
472     llvm_unreachable("Invalid DWARF format");
473   case dwarf::DW_FORM_GNU_str_index:
474   case dwarf::DW_FORM_GNU_addr_index:
475   case dwarf::DW_FORM_ref_udata:
476   case dwarf::DW_FORM_strx:
477   case dwarf::DW_FORM_udata:
478     return getULEB128Size(Integer);
479   case dwarf::DW_FORM_sdata:
480     return getSLEB128Size(Integer);
481   case dwarf::DW_FORM_addr:
482     return AP->getPointerSize();
483   default: llvm_unreachable("DIE Value form not supported yet");
484   }
485 }
486 
487 LLVM_DUMP_METHOD
488 void DIEInteger::print(raw_ostream &O) const {
489   O << "Int: " << (int64_t)Integer << "  0x";
490   O.write_hex(Integer);
491 }
492 
493 //===----------------------------------------------------------------------===//
494 // DIEExpr Implementation
495 //===----------------------------------------------------------------------===//
496 
497 /// EmitValue - Emit expression value.
498 ///
499 void DIEExpr::EmitValue(const AsmPrinter *AP, dwarf::Form Form) const {
500   AP->EmitDebugThreadLocal(Expr, SizeOf(AP, Form));
501 }
502 
503 /// SizeOf - Determine size of expression value in bytes.
504 ///
505 unsigned DIEExpr::SizeOf(const AsmPrinter *AP, dwarf::Form Form) const {
506   if (Form == dwarf::DW_FORM_data4) return 4;
507   if (Form == dwarf::DW_FORM_sec_offset) return 4;
508   if (Form == dwarf::DW_FORM_strp) return 4;
509   return AP->getPointerSize();
510 }
511 
512 LLVM_DUMP_METHOD
513 void DIEExpr::print(raw_ostream &O) const { O << "Expr: " << *Expr; }
514 
515 //===----------------------------------------------------------------------===//
516 // DIELabel Implementation
517 //===----------------------------------------------------------------------===//
518 
519 /// EmitValue - Emit label value.
520 ///
521 void DIELabel::EmitValue(const AsmPrinter *AP, dwarf::Form Form) const {
522   AP->EmitLabelReference(Label, SizeOf(AP, Form),
523                          Form == dwarf::DW_FORM_strp ||
524                              Form == dwarf::DW_FORM_sec_offset ||
525                              Form == dwarf::DW_FORM_ref_addr ||
526                              Form == dwarf::DW_FORM_data4);
527 }
528 
529 /// SizeOf - Determine size of label value in bytes.
530 ///
531 unsigned DIELabel::SizeOf(const AsmPrinter *AP, dwarf::Form Form) const {
532   if (Form == dwarf::DW_FORM_data4) return 4;
533   if (Form == dwarf::DW_FORM_sec_offset) return 4;
534   if (Form == dwarf::DW_FORM_strp) return 4;
535   return AP->MAI->getCodePointerSize();
536 }
537 
538 LLVM_DUMP_METHOD
539 void DIELabel::print(raw_ostream &O) const { O << "Lbl: " << Label->getName(); }
540 
541 //===----------------------------------------------------------------------===//
542 // DIEDelta Implementation
543 //===----------------------------------------------------------------------===//
544 
545 /// EmitValue - Emit delta value.
546 ///
547 void DIEDelta::EmitValue(const AsmPrinter *AP, dwarf::Form Form) const {
548   AP->EmitLabelDifference(LabelHi, LabelLo, SizeOf(AP, Form));
549 }
550 
551 /// SizeOf - Determine size of delta value in bytes.
552 ///
553 unsigned DIEDelta::SizeOf(const AsmPrinter *AP, dwarf::Form Form) const {
554   if (Form == dwarf::DW_FORM_data4) return 4;
555   if (Form == dwarf::DW_FORM_sec_offset) return 4;
556   if (Form == dwarf::DW_FORM_strp) return 4;
557   return AP->MAI->getCodePointerSize();
558 }
559 
560 LLVM_DUMP_METHOD
561 void DIEDelta::print(raw_ostream &O) const {
562   O << "Del: " << LabelHi->getName() << "-" << LabelLo->getName();
563 }
564 
565 //===----------------------------------------------------------------------===//
566 // DIEString Implementation
567 //===----------------------------------------------------------------------===//
568 
569 /// EmitValue - Emit string value.
570 ///
571 void DIEString::EmitValue(const AsmPrinter *AP, dwarf::Form Form) const {
572   // Index of string in symbol table.
573   switch (Form) {
574   case dwarf::DW_FORM_GNU_str_index:
575   case dwarf::DW_FORM_strx:
576   case dwarf::DW_FORM_strx1:
577   case dwarf::DW_FORM_strx2:
578   case dwarf::DW_FORM_strx3:
579   case dwarf::DW_FORM_strx4:
580     DIEInteger(S.getIndex()).EmitValue(AP, Form);
581     return;
582   case dwarf::DW_FORM_strp:
583     if (AP->MAI->doesDwarfUseRelocationsAcrossSections())
584       DIELabel(S.getSymbol()).EmitValue(AP, Form);
585     else
586       DIEInteger(S.getOffset()).EmitValue(AP, Form);
587     return;
588   default:
589     llvm_unreachable("Expected valid string form");
590   }
591 }
592 
593 /// SizeOf - Determine size of delta value in bytes.
594 ///
595 unsigned DIEString::SizeOf(const AsmPrinter *AP, dwarf::Form Form) const {
596   // Index of string in symbol table.
597   switch (Form) {
598   case dwarf::DW_FORM_GNU_str_index:
599   case dwarf::DW_FORM_strx:
600   case dwarf::DW_FORM_strx1:
601   case dwarf::DW_FORM_strx2:
602   case dwarf::DW_FORM_strx3:
603   case dwarf::DW_FORM_strx4:
604     return DIEInteger(S.getIndex()).SizeOf(AP, Form);
605   case dwarf::DW_FORM_strp:
606     if (AP->MAI->doesDwarfUseRelocationsAcrossSections())
607       return DIELabel(S.getSymbol()).SizeOf(AP, Form);
608     return DIEInteger(S.getOffset()).SizeOf(AP, Form);
609   default:
610     llvm_unreachable("Expected valid string form");
611   }
612 }
613 
614 LLVM_DUMP_METHOD
615 void DIEString::print(raw_ostream &O) const {
616   O << "String: " << S.getString();
617 }
618 
619 //===----------------------------------------------------------------------===//
620 // DIEInlineString Implementation
621 //===----------------------------------------------------------------------===//
622 void DIEInlineString::EmitValue(const AsmPrinter *AP, dwarf::Form Form) const {
623   if (Form == dwarf::DW_FORM_string) {
624     for (char ch : S)
625       AP->EmitInt8(ch);
626     AP->EmitInt8(0);
627     return;
628   }
629   llvm_unreachable("Expected valid string form");
630 }
631 
632 unsigned DIEInlineString::SizeOf(const AsmPrinter *AP, dwarf::Form Form) const {
633   // Emit string bytes + NULL byte.
634   return S.size() + 1;
635 }
636 
637 LLVM_DUMP_METHOD
638 void DIEInlineString::print(raw_ostream &O) const {
639   O << "InlineString: " << S;
640 }
641 
642 //===----------------------------------------------------------------------===//
643 // DIEEntry Implementation
644 //===----------------------------------------------------------------------===//
645 
646 /// EmitValue - Emit debug information entry offset.
647 ///
648 void DIEEntry::EmitValue(const AsmPrinter *AP, dwarf::Form Form) const {
649 
650   switch (Form) {
651   case dwarf::DW_FORM_ref1:
652   case dwarf::DW_FORM_ref2:
653   case dwarf::DW_FORM_ref4:
654   case dwarf::DW_FORM_ref8:
655     AP->OutStreamer->EmitIntValue(Entry->getOffset(), SizeOf(AP, Form));
656     return;
657 
658   case dwarf::DW_FORM_ref_udata:
659     AP->EmitULEB128(Entry->getOffset());
660     return;
661 
662   case dwarf::DW_FORM_ref_addr: {
663     // Get the absolute offset for this DIE within the debug info/types section.
664     unsigned Addr = Entry->getDebugSectionOffset();
665     if (const MCSymbol *SectionSym =
666             Entry->getUnit()->getCrossSectionRelativeBaseAddress()) {
667       AP->EmitLabelPlusOffset(SectionSym, Addr, SizeOf(AP, Form), true);
668       return;
669     }
670 
671     AP->OutStreamer->EmitIntValue(Addr, SizeOf(AP, Form));
672     return;
673   }
674   default:
675     llvm_unreachable("Improper form for DIE reference");
676   }
677 }
678 
679 unsigned DIEEntry::SizeOf(const AsmPrinter *AP, dwarf::Form Form) const {
680   switch (Form) {
681   case dwarf::DW_FORM_ref1:
682     return 1;
683   case dwarf::DW_FORM_ref2:
684     return 2;
685   case dwarf::DW_FORM_ref4:
686     return 4;
687   case dwarf::DW_FORM_ref8:
688     return 8;
689   case dwarf::DW_FORM_ref_udata:
690     return getULEB128Size(Entry->getOffset());
691   case dwarf::DW_FORM_ref_addr:
692     if (AP->getDwarfVersion() == 2)
693       return AP->MAI->getCodePointerSize();
694     switch (AP->OutStreamer->getContext().getDwarfFormat()) {
695     case dwarf::DWARF32:
696       return 4;
697     case dwarf::DWARF64:
698       return 8;
699     }
700     llvm_unreachable("Invalid DWARF format");
701 
702   default:
703     llvm_unreachable("Improper form for DIE reference");
704   }
705 }
706 
707 LLVM_DUMP_METHOD
708 void DIEEntry::print(raw_ostream &O) const {
709   O << format("Die: 0x%lx", (long)(intptr_t)&Entry);
710 }
711 
712 //===----------------------------------------------------------------------===//
713 // DIELoc Implementation
714 //===----------------------------------------------------------------------===//
715 
716 /// ComputeSize - calculate the size of the location expression.
717 ///
718 unsigned DIELoc::ComputeSize(const AsmPrinter *AP) const {
719   if (!Size) {
720     for (const auto &V : values())
721       Size += V.SizeOf(AP);
722   }
723 
724   return Size;
725 }
726 
727 /// EmitValue - Emit location data.
728 ///
729 void DIELoc::EmitValue(const AsmPrinter *Asm, dwarf::Form Form) const {
730   switch (Form) {
731   default: llvm_unreachable("Improper form for block");
732   case dwarf::DW_FORM_block1: Asm->EmitInt8(Size);    break;
733   case dwarf::DW_FORM_block2: Asm->EmitInt16(Size);   break;
734   case dwarf::DW_FORM_block4: Asm->EmitInt32(Size);   break;
735   case dwarf::DW_FORM_block:
736   case dwarf::DW_FORM_exprloc:
737     Asm->EmitULEB128(Size); break;
738   }
739 
740   for (const auto &V : values())
741     V.EmitValue(Asm);
742 }
743 
744 /// SizeOf - Determine size of location data in bytes.
745 ///
746 unsigned DIELoc::SizeOf(const AsmPrinter *AP, dwarf::Form Form) const {
747   switch (Form) {
748   case dwarf::DW_FORM_block1: return Size + sizeof(int8_t);
749   case dwarf::DW_FORM_block2: return Size + sizeof(int16_t);
750   case dwarf::DW_FORM_block4: return Size + sizeof(int32_t);
751   case dwarf::DW_FORM_block:
752   case dwarf::DW_FORM_exprloc:
753     return Size + getULEB128Size(Size);
754   default: llvm_unreachable("Improper form for block");
755   }
756 }
757 
758 LLVM_DUMP_METHOD
759 void DIELoc::print(raw_ostream &O) const {
760   printValues(O, *this, "ExprLoc", Size, 5);
761 }
762 
763 //===----------------------------------------------------------------------===//
764 // DIEBlock Implementation
765 //===----------------------------------------------------------------------===//
766 
767 /// ComputeSize - calculate the size of the block.
768 ///
769 unsigned DIEBlock::ComputeSize(const AsmPrinter *AP) const {
770   if (!Size) {
771     for (const auto &V : values())
772       Size += V.SizeOf(AP);
773   }
774 
775   return Size;
776 }
777 
778 /// EmitValue - Emit block data.
779 ///
780 void DIEBlock::EmitValue(const AsmPrinter *Asm, dwarf::Form Form) const {
781   switch (Form) {
782   default: llvm_unreachable("Improper form for block");
783   case dwarf::DW_FORM_block1: Asm->EmitInt8(Size);    break;
784   case dwarf::DW_FORM_block2: Asm->EmitInt16(Size);   break;
785   case dwarf::DW_FORM_block4: Asm->EmitInt32(Size);   break;
786   case dwarf::DW_FORM_block:  Asm->EmitULEB128(Size); break;
787   case dwarf::DW_FORM_data16: break;
788   }
789 
790   for (const auto &V : values())
791     V.EmitValue(Asm);
792 }
793 
794 /// SizeOf - Determine size of block data in bytes.
795 ///
796 unsigned DIEBlock::SizeOf(const AsmPrinter *AP, dwarf::Form Form) const {
797   switch (Form) {
798   case dwarf::DW_FORM_block1: return Size + sizeof(int8_t);
799   case dwarf::DW_FORM_block2: return Size + sizeof(int16_t);
800   case dwarf::DW_FORM_block4: return Size + sizeof(int32_t);
801   case dwarf::DW_FORM_block:  return Size + getULEB128Size(Size);
802   case dwarf::DW_FORM_data16: return 16;
803   default: llvm_unreachable("Improper form for block");
804   }
805 }
806 
807 LLVM_DUMP_METHOD
808 void DIEBlock::print(raw_ostream &O) const {
809   printValues(O, *this, "Blk", Size, 5);
810 }
811 
812 //===----------------------------------------------------------------------===//
813 // DIELocList Implementation
814 //===----------------------------------------------------------------------===//
815 
816 unsigned DIELocList::SizeOf(const AsmPrinter *AP, dwarf::Form Form) const {
817   if (Form == dwarf::DW_FORM_data4)
818     return 4;
819   if (Form == dwarf::DW_FORM_sec_offset)
820     return 4;
821   return AP->MAI->getCodePointerSize();
822 }
823 
824 /// EmitValue - Emit label value.
825 ///
826 void DIELocList::EmitValue(const AsmPrinter *AP, dwarf::Form Form) const {
827   DwarfDebug *DD = AP->getDwarfDebug();
828   MCSymbol *Label = DD->getDebugLocs().getList(Index).Label;
829   AP->emitDwarfSymbolReference(Label, /*ForceOffset*/ DD->useSplitDwarf());
830 }
831 
832 LLVM_DUMP_METHOD
833 void DIELocList::print(raw_ostream &O) const { O << "LocList: " << Index; }
834