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 //===----------------------------------------------------------------------===//
35 // DIEAbbrevData Implementation
36 //===----------------------------------------------------------------------===//
37 
38 /// Profile - Used to gather unique data for the abbreviation folding set.
39 ///
40 void DIEAbbrevData::Profile(FoldingSetNodeID &ID) const {
41   // Explicitly cast to an integer type for which FoldingSetNodeID has
42   // overloads.  Otherwise MSVC 2010 thinks this call is ambiguous.
43   ID.AddInteger(unsigned(Attribute));
44   ID.AddInteger(unsigned(Form));
45 }
46 
47 //===----------------------------------------------------------------------===//
48 // DIEAbbrev Implementation
49 //===----------------------------------------------------------------------===//
50 
51 /// Profile - Used to gather unique data for the abbreviation folding set.
52 ///
53 void DIEAbbrev::Profile(FoldingSetNodeID &ID) const {
54   ID.AddInteger(unsigned(Tag));
55   ID.AddInteger(unsigned(Children));
56 
57   // For each attribute description.
58   for (unsigned i = 0, N = Data.size(); i < N; ++i)
59     Data[i].Profile(ID);
60 }
61 
62 /// Emit - Print the abbreviation using the specified asm printer.
63 ///
64 void DIEAbbrev::Emit(const AsmPrinter *AP) const {
65   // Emit its Dwarf tag type.
66   AP->EmitULEB128(Tag, dwarf::TagString(Tag).data());
67 
68   // Emit whether it has children DIEs.
69   AP->EmitULEB128((unsigned)Children, dwarf::ChildrenString(Children).data());
70 
71   // For each attribute description.
72   for (unsigned i = 0, N = Data.size(); i < N; ++i) {
73     const DIEAbbrevData &AttrData = Data[i];
74 
75     // Emit attribute type.
76     AP->EmitULEB128(AttrData.getAttribute(),
77                     dwarf::AttributeString(AttrData.getAttribute()).data());
78 
79     // Emit form type.
80     AP->EmitULEB128(AttrData.getForm(),
81                     dwarf::FormEncodingString(AttrData.getForm()).data());
82 
83     // Emit value for DW_FORM_implicit_const.
84     if (AttrData.getForm() == dwarf::DW_FORM_implicit_const) {
85       assert(AP->getDwarfVersion() >= 5 &&
86             "DW_FORM_implicit_const is supported starting from DWARFv5");
87       AP->EmitSLEB128(AttrData.getValue());
88     }
89   }
90 
91   // Mark end of abbreviation.
92   AP->EmitULEB128(0, "EOM(1)");
93   AP->EmitULEB128(0, "EOM(2)");
94 }
95 
96 LLVM_DUMP_METHOD
97 void DIEAbbrev::print(raw_ostream &O) {
98   O << "Abbreviation @"
99     << format("0x%lx", (long)(intptr_t)this)
100     << "  "
101     << dwarf::TagString(Tag)
102     << " "
103     << dwarf::ChildrenString(Children)
104     << '\n';
105 
106   for (unsigned i = 0, N = Data.size(); i < N; ++i) {
107     O << "  "
108       << dwarf::AttributeString(Data[i].getAttribute())
109       << "  "
110       << dwarf::FormEncodingString(Data[i].getForm())
111       << '\n';
112   }
113 }
114 
115 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
116 LLVM_DUMP_METHOD void DIEAbbrev::dump() {
117   print(dbgs());
118 }
119 #endif
120 
121 //===----------------------------------------------------------------------===//
122 // DIEAbbrevSet Implementation
123 //===----------------------------------------------------------------------===//
124 
125 DIEAbbrevSet::~DIEAbbrevSet() {
126   for (DIEAbbrev *Abbrev : Abbreviations)
127     Abbrev->~DIEAbbrev();
128 }
129 
130 DIEAbbrev &DIEAbbrevSet::uniqueAbbreviation(DIE &Die) {
131 
132   FoldingSetNodeID ID;
133   DIEAbbrev Abbrev = Die.generateAbbrev();
134   Abbrev.Profile(ID);
135 
136   void *InsertPos;
137   if (DIEAbbrev *Existing =
138           AbbreviationsSet.FindNodeOrInsertPos(ID, InsertPos)) {
139     Die.setAbbrevNumber(Existing->getNumber());
140     return *Existing;
141   }
142 
143   // Move the abbreviation to the heap and assign a number.
144   DIEAbbrev *New = new (Alloc) DIEAbbrev(std::move(Abbrev));
145   Abbreviations.push_back(New);
146   New->setNumber(Abbreviations.size());
147   Die.setAbbrevNumber(Abbreviations.size());
148 
149   // Store it for lookup.
150   AbbreviationsSet.InsertNode(New, InsertPos);
151   return *New;
152 }
153 
154 void DIEAbbrevSet::Emit(const AsmPrinter *AP, MCSection *Section) const {
155   if (!Abbreviations.empty()) {
156     // Start the debug abbrev section.
157     AP->OutStreamer->SwitchSection(Section);
158     AP->emitDwarfAbbrevs(Abbreviations);
159   }
160 }
161 
162 //===----------------------------------------------------------------------===//
163 // DIE Implementation
164 //===----------------------------------------------------------------------===//
165 
166 DIE *DIE::getParent() const {
167   return Owner.dyn_cast<DIE*>();
168 }
169 
170 DIEAbbrev DIE::generateAbbrev() const {
171   DIEAbbrev Abbrev(Tag, hasChildren());
172   for (const DIEValue &V : values())
173     if (V.getForm() == dwarf::DW_FORM_implicit_const)
174       Abbrev.AddImplicitConstAttribute(V.getAttribute(),
175                                        V.getDIEInteger().getValue());
176     else
177       Abbrev.AddAttribute(V.getAttribute(), V.getForm());
178   return Abbrev;
179 }
180 
181 unsigned DIE::getDebugSectionOffset() const {
182   const DIEUnit *Unit = getUnit();
183   assert(Unit && "DIE must be owned by a DIEUnit to get its absolute offset");
184   return Unit->getDebugSectionOffset() + getOffset();
185 }
186 
187 const DIE *DIE::getUnitDie() const {
188   const DIE *p = this;
189   while (p) {
190     if (p->getTag() == dwarf::DW_TAG_compile_unit ||
191         p->getTag() == dwarf::DW_TAG_type_unit)
192       return p;
193     p = p->getParent();
194   }
195   return nullptr;
196 }
197 
198 const DIEUnit *DIE::getUnit() const {
199   const DIE *UnitDie = getUnitDie();
200   if (UnitDie)
201     return UnitDie->Owner.dyn_cast<DIEUnit*>();
202   return nullptr;
203 }
204 
205 DIEValue DIE::findAttribute(dwarf::Attribute Attribute) const {
206   // Iterate through all the attributes until we find the one we're
207   // looking for, if we can't find it return NULL.
208   for (const auto &V : values())
209     if (V.getAttribute() == Attribute)
210       return V;
211   return DIEValue();
212 }
213 
214 LLVM_DUMP_METHOD
215 static void printValues(raw_ostream &O, const DIEValueList &Values,
216                         StringRef Type, unsigned Size, unsigned IndentCount) {
217   O << Type << ": Size: " << Size << "\n";
218 
219   unsigned I = 0;
220   const std::string Indent(IndentCount, ' ');
221   for (const auto &V : Values.values()) {
222     O << Indent;
223     O << "Blk[" << I++ << "]";
224     O << "  " << dwarf::FormEncodingString(V.getForm()) << " ";
225     V.print(O);
226     O << "\n";
227   }
228 }
229 
230 LLVM_DUMP_METHOD
231 void DIE::print(raw_ostream &O, unsigned IndentCount) const {
232   const std::string Indent(IndentCount, ' ');
233   O << Indent << "Die: " << format("0x%lx", (long)(intptr_t) this)
234     << ", Offset: " << Offset << ", Size: " << Size << "\n";
235 
236   O << Indent << dwarf::TagString(getTag()) << " "
237     << dwarf::ChildrenString(hasChildren()) << "\n";
238 
239   IndentCount += 2;
240   for (const auto &V : values()) {
241     O << Indent;
242     O << dwarf::AttributeString(V.getAttribute());
243     O << "  " << dwarf::FormEncodingString(V.getForm()) << " ";
244     V.print(O);
245     O << "\n";
246   }
247   IndentCount -= 2;
248 
249   for (const auto &Child : children())
250     Child.print(O, IndentCount + 4);
251 
252   O << "\n";
253 }
254 
255 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
256 LLVM_DUMP_METHOD void DIE::dump() {
257   print(dbgs());
258 }
259 #endif
260 
261 unsigned DIE::computeOffsetsAndAbbrevs(const AsmPrinter *AP,
262                                        DIEAbbrevSet &AbbrevSet,
263                                        unsigned CUOffset) {
264   // Unique the abbreviation and fill in the abbreviation number so this DIE
265   // can be emitted.
266   const DIEAbbrev &Abbrev = AbbrevSet.uniqueAbbreviation(*this);
267 
268   // Set compile/type unit relative offset of this DIE.
269   setOffset(CUOffset);
270 
271   // Add the byte size of the abbreviation code.
272   CUOffset += getULEB128Size(getAbbrevNumber());
273 
274   // Add the byte size of all the DIE attribute values.
275   for (const auto &V : values())
276     CUOffset += V.SizeOf(AP);
277 
278   // Let the children compute their offsets and abbreviation numbers.
279   if (hasChildren()) {
280     (void)Abbrev;
281     assert(Abbrev.hasChildren() && "Children flag not set");
282 
283     for (auto &Child : children())
284       CUOffset = Child.computeOffsetsAndAbbrevs(AP, AbbrevSet, CUOffset);
285 
286     // Each child chain is terminated with a zero byte, adjust the offset.
287     CUOffset += sizeof(int8_t);
288   }
289 
290   // Compute the byte size of this DIE and all of its children correctly. This
291   // is needed so that top level DIE can help the compile unit set its length
292   // correctly.
293   setSize(CUOffset - getOffset());
294   return CUOffset;
295 }
296 
297 //===----------------------------------------------------------------------===//
298 // DIEUnit Implementation
299 //===----------------------------------------------------------------------===//
300 DIEUnit::DIEUnit(uint16_t V, uint8_t A, dwarf::Tag UnitTag)
301     : Die(UnitTag), Section(nullptr), Offset(0), Length(0), Version(V),
302       AddrSize(A)
303 {
304   Die.Owner = this;
305   assert((UnitTag == dwarf::DW_TAG_compile_unit ||
306           UnitTag == dwarf::DW_TAG_type_unit ||
307           UnitTag == dwarf::DW_TAG_partial_unit) && "expected a unit TAG");
308 }
309 
310 void DIEValue::EmitValue(const AsmPrinter *AP) const {
311   switch (Ty) {
312   case isNone:
313     llvm_unreachable("Expected valid DIEValue");
314 #define HANDLE_DIEVALUE(T)                                                     \
315   case is##T:                                                                  \
316     getDIE##T().EmitValue(AP, Form);                                           \
317     break;
318 #include "llvm/CodeGen/DIEValue.def"
319   }
320 }
321 
322 unsigned DIEValue::SizeOf(const AsmPrinter *AP) const {
323   switch (Ty) {
324   case isNone:
325     llvm_unreachable("Expected valid DIEValue");
326 #define HANDLE_DIEVALUE(T)                                                     \
327   case is##T:                                                                  \
328     return getDIE##T().SizeOf(AP, Form);
329 #include "llvm/CodeGen/DIEValue.def"
330   }
331   llvm_unreachable("Unknown DIE kind");
332 }
333 
334 LLVM_DUMP_METHOD
335 void DIEValue::print(raw_ostream &O) const {
336   switch (Ty) {
337   case isNone:
338     llvm_unreachable("Expected valid DIEValue");
339 #define HANDLE_DIEVALUE(T)                                                     \
340   case is##T:                                                                  \
341     getDIE##T().print(O);                                                      \
342     break;
343 #include "llvm/CodeGen/DIEValue.def"
344   }
345 }
346 
347 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
348 LLVM_DUMP_METHOD void DIEValue::dump() const {
349   print(dbgs());
350 }
351 #endif
352 
353 //===----------------------------------------------------------------------===//
354 // DIEInteger Implementation
355 //===----------------------------------------------------------------------===//
356 
357 /// EmitValue - Emit integer of appropriate size.
358 ///
359 void DIEInteger::EmitValue(const AsmPrinter *Asm, dwarf::Form Form) const {
360   switch (Form) {
361   case dwarf::DW_FORM_implicit_const:
362     LLVM_FALLTHROUGH;
363   case dwarf::DW_FORM_flag_present:
364     // Emit something to keep the lines and comments in sync.
365     // FIXME: Is there a better way to do this?
366     Asm->OutStreamer->AddBlankLine();
367     return;
368   case dwarf::DW_FORM_flag:
369     LLVM_FALLTHROUGH;
370   case dwarf::DW_FORM_ref1:
371     LLVM_FALLTHROUGH;
372   case dwarf::DW_FORM_data1:
373     LLVM_FALLTHROUGH;
374   case dwarf::DW_FORM_ref2:
375     LLVM_FALLTHROUGH;
376   case dwarf::DW_FORM_data2:
377     LLVM_FALLTHROUGH;
378   case dwarf::DW_FORM_strp:
379     LLVM_FALLTHROUGH;
380   case dwarf::DW_FORM_ref4:
381     LLVM_FALLTHROUGH;
382   case dwarf::DW_FORM_data4:
383     LLVM_FALLTHROUGH;
384   case dwarf::DW_FORM_ref8:
385     LLVM_FALLTHROUGH;
386   case dwarf::DW_FORM_ref_sig8:
387     LLVM_FALLTHROUGH;
388   case dwarf::DW_FORM_data8:
389     LLVM_FALLTHROUGH;
390   case dwarf::DW_FORM_GNU_ref_alt:
391     LLVM_FALLTHROUGH;
392   case dwarf::DW_FORM_GNU_strp_alt:
393     LLVM_FALLTHROUGH;
394   case dwarf::DW_FORM_line_strp:
395     LLVM_FALLTHROUGH;
396   case dwarf::DW_FORM_sec_offset:
397     LLVM_FALLTHROUGH;
398   case dwarf::DW_FORM_strp_sup:
399     LLVM_FALLTHROUGH;
400   case dwarf::DW_FORM_ref_sup:
401     LLVM_FALLTHROUGH;
402   case dwarf::DW_FORM_addr:
403     LLVM_FALLTHROUGH;
404   case dwarf::DW_FORM_ref_addr:
405     Asm->OutStreamer->EmitIntValue(Integer, SizeOf(Asm, Form));
406     return;
407   case dwarf::DW_FORM_GNU_str_index:
408     LLVM_FALLTHROUGH;
409   case dwarf::DW_FORM_GNU_addr_index:
410     LLVM_FALLTHROUGH;
411   case dwarf::DW_FORM_ref_udata:
412     LLVM_FALLTHROUGH;
413   case dwarf::DW_FORM_udata:
414     Asm->EmitULEB128(Integer);
415     return;
416   case dwarf::DW_FORM_sdata:
417     Asm->EmitSLEB128(Integer);
418     return;
419   default: llvm_unreachable("DIE Value form not supported yet");
420   }
421 }
422 
423 /// SizeOf - Determine size of integer value in bytes.
424 ///
425 unsigned DIEInteger::SizeOf(const AsmPrinter *AP, dwarf::Form Form) const {
426   switch (Form) {
427   case dwarf::DW_FORM_implicit_const: LLVM_FALLTHROUGH;
428   case dwarf::DW_FORM_flag_present: return 0;
429   case dwarf::DW_FORM_flag:  LLVM_FALLTHROUGH;
430   case dwarf::DW_FORM_ref1:  LLVM_FALLTHROUGH;
431   case dwarf::DW_FORM_data1: return sizeof(int8_t);
432   case dwarf::DW_FORM_ref2:  LLVM_FALLTHROUGH;
433   case dwarf::DW_FORM_data2: return sizeof(int16_t);
434   case dwarf::DW_FORM_ref4:  LLVM_FALLTHROUGH;
435   case dwarf::DW_FORM_data4: return sizeof(int32_t);
436   case dwarf::DW_FORM_ref8:  LLVM_FALLTHROUGH;
437   case dwarf::DW_FORM_ref_sig8:  LLVM_FALLTHROUGH;
438   case dwarf::DW_FORM_data8: return sizeof(int64_t);
439   case dwarf::DW_FORM_ref_addr:
440     if (AP->getDwarfVersion() == 2)
441       return AP->getPointerSize();
442     LLVM_FALLTHROUGH;
443   case dwarf::DW_FORM_strp:
444     LLVM_FALLTHROUGH;
445   case dwarf::DW_FORM_GNU_ref_alt:
446     LLVM_FALLTHROUGH;
447   case dwarf::DW_FORM_GNU_strp_alt:
448     LLVM_FALLTHROUGH;
449   case dwarf::DW_FORM_line_strp:
450     LLVM_FALLTHROUGH;
451   case dwarf::DW_FORM_sec_offset:
452     LLVM_FALLTHROUGH;
453   case dwarf::DW_FORM_strp_sup:
454     LLVM_FALLTHROUGH;
455   case dwarf::DW_FORM_ref_sup:
456     switch (AP->OutStreamer->getContext().getDwarfFormat()) {
457     case dwarf::DWARF32:
458       return 4;
459     case dwarf::DWARF64:
460       return 8;
461     }
462     llvm_unreachable("Invalid DWARF format");
463   case dwarf::DW_FORM_GNU_str_index:
464     LLVM_FALLTHROUGH;
465   case dwarf::DW_FORM_GNU_addr_index:
466     LLVM_FALLTHROUGH;
467   case dwarf::DW_FORM_ref_udata:
468     LLVM_FALLTHROUGH;
469   case dwarf::DW_FORM_udata:
470     return getULEB128Size(Integer);
471   case dwarf::DW_FORM_sdata:
472     return getSLEB128Size(Integer);
473   case dwarf::DW_FORM_addr:
474     return AP->getPointerSize();
475   default: llvm_unreachable("DIE Value form not supported yet");
476   }
477 }
478 
479 LLVM_DUMP_METHOD
480 void DIEInteger::print(raw_ostream &O) const {
481   O << "Int: " << (int64_t)Integer << "  0x";
482   O.write_hex(Integer);
483 }
484 
485 //===----------------------------------------------------------------------===//
486 // DIEExpr Implementation
487 //===----------------------------------------------------------------------===//
488 
489 /// EmitValue - Emit expression value.
490 ///
491 void DIEExpr::EmitValue(const AsmPrinter *AP, dwarf::Form Form) const {
492   AP->EmitDebugValue(Expr, SizeOf(AP, Form));
493 }
494 
495 /// SizeOf - Determine size of expression value in bytes.
496 ///
497 unsigned DIEExpr::SizeOf(const AsmPrinter *AP, dwarf::Form Form) const {
498   if (Form == dwarf::DW_FORM_data4) return 4;
499   if (Form == dwarf::DW_FORM_sec_offset) return 4;
500   if (Form == dwarf::DW_FORM_strp) return 4;
501   return AP->getPointerSize();
502 }
503 
504 LLVM_DUMP_METHOD
505 void DIEExpr::print(raw_ostream &O) const { O << "Expr: " << *Expr; }
506 
507 //===----------------------------------------------------------------------===//
508 // DIELabel Implementation
509 //===----------------------------------------------------------------------===//
510 
511 /// EmitValue - Emit label value.
512 ///
513 void DIELabel::EmitValue(const AsmPrinter *AP, dwarf::Form Form) const {
514   AP->EmitLabelReference(Label, SizeOf(AP, Form),
515                          Form == dwarf::DW_FORM_strp ||
516                              Form == dwarf::DW_FORM_sec_offset ||
517                              Form == dwarf::DW_FORM_ref_addr ||
518                              Form == dwarf::DW_FORM_data4);
519 }
520 
521 /// SizeOf - Determine size of label value in bytes.
522 ///
523 unsigned DIELabel::SizeOf(const AsmPrinter *AP, dwarf::Form Form) const {
524   if (Form == dwarf::DW_FORM_data4) return 4;
525   if (Form == dwarf::DW_FORM_sec_offset) return 4;
526   if (Form == dwarf::DW_FORM_strp) return 4;
527   return AP->getPointerSize();
528 }
529 
530 LLVM_DUMP_METHOD
531 void DIELabel::print(raw_ostream &O) const { O << "Lbl: " << Label->getName(); }
532 
533 //===----------------------------------------------------------------------===//
534 // DIEDelta Implementation
535 //===----------------------------------------------------------------------===//
536 
537 /// EmitValue - Emit delta value.
538 ///
539 void DIEDelta::EmitValue(const AsmPrinter *AP, dwarf::Form Form) const {
540   AP->EmitLabelDifference(LabelHi, LabelLo, SizeOf(AP, Form));
541 }
542 
543 /// SizeOf - Determine size of delta value in bytes.
544 ///
545 unsigned DIEDelta::SizeOf(const AsmPrinter *AP, dwarf::Form Form) const {
546   if (Form == dwarf::DW_FORM_data4) return 4;
547   if (Form == dwarf::DW_FORM_sec_offset) return 4;
548   if (Form == dwarf::DW_FORM_strp) return 4;
549   return AP->getPointerSize();
550 }
551 
552 LLVM_DUMP_METHOD
553 void DIEDelta::print(raw_ostream &O) const {
554   O << "Del: " << LabelHi->getName() << "-" << LabelLo->getName();
555 }
556 
557 //===----------------------------------------------------------------------===//
558 // DIEString Implementation
559 //===----------------------------------------------------------------------===//
560 
561 /// EmitValue - Emit string value.
562 ///
563 void DIEString::EmitValue(const AsmPrinter *AP, dwarf::Form Form) const {
564   assert(
565       (Form == dwarf::DW_FORM_strp || Form == dwarf::DW_FORM_GNU_str_index) &&
566       "Expected valid string form");
567 
568   // Index of string in symbol table.
569   if (Form == dwarf::DW_FORM_GNU_str_index) {
570     DIEInteger(S.getIndex()).EmitValue(AP, Form);
571     return;
572   }
573 
574   // Relocatable symbol.
575   assert(Form == dwarf::DW_FORM_strp);
576   if (AP->MAI->doesDwarfUseRelocationsAcrossSections()) {
577     DIELabel(S.getSymbol()).EmitValue(AP, Form);
578     return;
579   }
580 
581   // Offset into symbol table.
582   DIEInteger(S.getOffset()).EmitValue(AP, Form);
583 }
584 
585 /// SizeOf - Determine size of delta value in bytes.
586 ///
587 unsigned DIEString::SizeOf(const AsmPrinter *AP, dwarf::Form Form) const {
588   assert(
589       (Form == dwarf::DW_FORM_strp || Form == dwarf::DW_FORM_GNU_str_index) &&
590       "Expected valid string form");
591 
592   // Index of string in symbol table.
593   if (Form == dwarf::DW_FORM_GNU_str_index)
594     return DIEInteger(S.getIndex()).SizeOf(AP, Form);
595 
596   // Relocatable symbol.
597   if (AP->MAI->doesDwarfUseRelocationsAcrossSections())
598     return DIELabel(S.getSymbol()).SizeOf(AP, Form);
599 
600   // Offset into symbol table.
601   return DIEInteger(S.getOffset()).SizeOf(AP, Form);
602 }
603 
604 LLVM_DUMP_METHOD
605 void DIEString::print(raw_ostream &O) const {
606   O << "String: " << S.getString();
607 }
608 
609 //===----------------------------------------------------------------------===//
610 // DIEInlineString Implementation
611 //===----------------------------------------------------------------------===//
612 void DIEInlineString::EmitValue(const AsmPrinter *AP, dwarf::Form Form) const {
613   if (Form == dwarf::DW_FORM_string) {
614     for (char ch : S)
615       AP->EmitInt8(ch);
616     AP->EmitInt8(0);
617     return;
618   }
619   llvm_unreachable("Expected valid string form");
620 }
621 
622 unsigned DIEInlineString::SizeOf(const AsmPrinter *AP, dwarf::Form Form) const {
623   // Emit string bytes + NULL byte.
624   return S.size() + 1;
625 }
626 
627 LLVM_DUMP_METHOD
628 void DIEInlineString::print(raw_ostream &O) const {
629   O << "InlineString: " << S;
630 }
631 
632 //===----------------------------------------------------------------------===//
633 // DIEEntry Implementation
634 //===----------------------------------------------------------------------===//
635 
636 /// EmitValue - Emit debug information entry offset.
637 ///
638 void DIEEntry::EmitValue(const AsmPrinter *AP, dwarf::Form Form) const {
639 
640   switch (Form) {
641   case dwarf::DW_FORM_ref1:
642   case dwarf::DW_FORM_ref2:
643   case dwarf::DW_FORM_ref4:
644   case dwarf::DW_FORM_ref8:
645     AP->OutStreamer->EmitIntValue(Entry->getOffset(), SizeOf(AP, Form));
646     return;
647 
648   case dwarf::DW_FORM_ref_udata:
649     AP->EmitULEB128(Entry->getOffset());
650     return;
651 
652   case dwarf::DW_FORM_ref_addr: {
653     // Get the absolute offset for this DIE within the debug info/types section.
654     unsigned Addr = Entry->getDebugSectionOffset();
655     if (AP->MAI->doesDwarfUseRelocationsAcrossSections()) {
656       const DwarfDebug *DD = AP->getDwarfDebug();
657       if (DD)
658         assert(!DD->useSplitDwarf() &&
659                "TODO: dwo files can't have relocations.");
660       const DIEUnit *Unit = Entry->getUnit();
661       assert(Unit && "CUDie should belong to a CU.");
662       MCSection *Section = Unit->getSection();
663       if (Section) {
664         const MCSymbol *SectionSym = Section->getBeginSymbol();
665         AP->EmitLabelPlusOffset(SectionSym, Addr, SizeOf(AP, Form), true);
666         return;
667       }
668     }
669     AP->OutStreamer->EmitIntValue(Addr, SizeOf(AP, Form));
670     return;
671   }
672   default:
673     llvm_unreachable("Improper form for DIE reference");
674   }
675 }
676 
677 unsigned DIEEntry::SizeOf(const AsmPrinter *AP, dwarf::Form Form) const {
678   switch (Form) {
679   case dwarf::DW_FORM_ref1:
680     return 1;
681   case dwarf::DW_FORM_ref2:
682     return 2;
683   case dwarf::DW_FORM_ref4:
684     return 4;
685   case dwarf::DW_FORM_ref8:
686     return 8;
687   case dwarf::DW_FORM_ref_udata:
688     return getULEB128Size(Entry->getOffset());
689   case dwarf::DW_FORM_ref_addr:
690     if (AP->getDwarfVersion() == 2)
691       return AP->getPointerSize();
692     switch (AP->OutStreamer->getContext().getDwarfFormat()) {
693     case dwarf::DWARF32:
694       return 4;
695     case dwarf::DWARF64:
696       return 8;
697     }
698     llvm_unreachable("Invalid DWARF format");
699 
700   default:
701     llvm_unreachable("Improper form for DIE reference");
702   }
703 }
704 
705 LLVM_DUMP_METHOD
706 void DIEEntry::print(raw_ostream &O) const {
707   O << format("Die: 0x%lx", (long)(intptr_t)&Entry);
708 }
709 
710 //===----------------------------------------------------------------------===//
711 // DIELoc Implementation
712 //===----------------------------------------------------------------------===//
713 
714 /// ComputeSize - calculate the size of the location expression.
715 ///
716 unsigned DIELoc::ComputeSize(const AsmPrinter *AP) const {
717   if (!Size) {
718     for (const auto &V : values())
719       Size += V.SizeOf(AP);
720   }
721 
722   return Size;
723 }
724 
725 /// EmitValue - Emit location data.
726 ///
727 void DIELoc::EmitValue(const AsmPrinter *Asm, dwarf::Form Form) const {
728   switch (Form) {
729   default: llvm_unreachable("Improper form for block");
730   case dwarf::DW_FORM_block1: Asm->EmitInt8(Size);    break;
731   case dwarf::DW_FORM_block2: Asm->EmitInt16(Size);   break;
732   case dwarf::DW_FORM_block4: Asm->EmitInt32(Size);   break;
733   case dwarf::DW_FORM_block:
734   case dwarf::DW_FORM_exprloc:
735     Asm->EmitULEB128(Size); break;
736   }
737 
738   for (const auto &V : values())
739     V.EmitValue(Asm);
740 }
741 
742 /// SizeOf - Determine size of location data in bytes.
743 ///
744 unsigned DIELoc::SizeOf(const AsmPrinter *AP, dwarf::Form Form) const {
745   switch (Form) {
746   case dwarf::DW_FORM_block1: return Size + sizeof(int8_t);
747   case dwarf::DW_FORM_block2: return Size + sizeof(int16_t);
748   case dwarf::DW_FORM_block4: return Size + sizeof(int32_t);
749   case dwarf::DW_FORM_block:
750   case dwarf::DW_FORM_exprloc:
751     return Size + getULEB128Size(Size);
752   default: llvm_unreachable("Improper form for block");
753   }
754 }
755 
756 LLVM_DUMP_METHOD
757 void DIELoc::print(raw_ostream &O) const {
758   printValues(O, *this, "ExprLoc", Size, 5);
759 }
760 
761 //===----------------------------------------------------------------------===//
762 // DIEBlock Implementation
763 //===----------------------------------------------------------------------===//
764 
765 /// ComputeSize - calculate the size of the block.
766 ///
767 unsigned DIEBlock::ComputeSize(const AsmPrinter *AP) const {
768   if (!Size) {
769     for (const auto &V : values())
770       Size += V.SizeOf(AP);
771   }
772 
773   return Size;
774 }
775 
776 /// EmitValue - Emit block data.
777 ///
778 void DIEBlock::EmitValue(const AsmPrinter *Asm, dwarf::Form Form) const {
779   switch (Form) {
780   default: llvm_unreachable("Improper form for block");
781   case dwarf::DW_FORM_block1: Asm->EmitInt8(Size);    break;
782   case dwarf::DW_FORM_block2: Asm->EmitInt16(Size);   break;
783   case dwarf::DW_FORM_block4: Asm->EmitInt32(Size);   break;
784   case dwarf::DW_FORM_block:  Asm->EmitULEB128(Size); break;
785   }
786 
787   for (const auto &V : values())
788     V.EmitValue(Asm);
789 }
790 
791 /// SizeOf - Determine size of block data in bytes.
792 ///
793 unsigned DIEBlock::SizeOf(const AsmPrinter *AP, dwarf::Form Form) const {
794   switch (Form) {
795   case dwarf::DW_FORM_block1: return Size + sizeof(int8_t);
796   case dwarf::DW_FORM_block2: return Size + sizeof(int16_t);
797   case dwarf::DW_FORM_block4: return Size + sizeof(int32_t);
798   case dwarf::DW_FORM_block:  return Size + getULEB128Size(Size);
799   default: llvm_unreachable("Improper form for block");
800   }
801 }
802 
803 LLVM_DUMP_METHOD
804 void DIEBlock::print(raw_ostream &O) const {
805   printValues(O, *this, "Blk", Size, 5);
806 }
807 
808 //===----------------------------------------------------------------------===//
809 // DIELocList Implementation
810 //===----------------------------------------------------------------------===//
811 
812 unsigned DIELocList::SizeOf(const AsmPrinter *AP, dwarf::Form Form) const {
813   if (Form == dwarf::DW_FORM_data4)
814     return 4;
815   if (Form == dwarf::DW_FORM_sec_offset)
816     return 4;
817   return AP->getPointerSize();
818 }
819 
820 /// EmitValue - Emit label value.
821 ///
822 void DIELocList::EmitValue(const AsmPrinter *AP, dwarf::Form Form) const {
823   DwarfDebug *DD = AP->getDwarfDebug();
824   MCSymbol *Label = DD->getDebugLocs().getList(Index).Label;
825   AP->emitDwarfSymbolReference(Label, /*ForceOffset*/ DD->useSplitDwarf());
826 }
827 
828 LLVM_DUMP_METHOD
829 void DIELocList::print(raw_ostream &O) const { O << "LocList: " << Index; }
830