1 //===--- DebugInfo.cpp - Debug Information Helper Classes -----------------===//
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 // This file implements the helper classes used to build and interpret debug
11 // information in LLVM IR form.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #include "llvm/IR/DebugInfo.h"
16 #include "LLVMContextImpl.h"
17 #include "llvm/ADT/STLExtras.h"
18 #include "llvm/ADT/SmallPtrSet.h"
19 #include "llvm/ADT/SmallString.h"
20 #include "llvm/Analysis/ValueTracking.h"
21 #include "llvm/IR/Constants.h"
22 #include "llvm/IR/DIBuilder.h"
23 #include "llvm/IR/DerivedTypes.h"
24 #include "llvm/IR/Instructions.h"
25 #include "llvm/IR/IntrinsicInst.h"
26 #include "llvm/IR/Intrinsics.h"
27 #include "llvm/IR/Module.h"
28 #include "llvm/IR/ValueHandle.h"
29 #include "llvm/Support/Debug.h"
30 #include "llvm/Support/Dwarf.h"
31 #include "llvm/Support/raw_ostream.h"
32 using namespace llvm;
33 using namespace llvm::dwarf;
34 
35 //===----------------------------------------------------------------------===//
36 // DIDescriptor
37 //===----------------------------------------------------------------------===//
38 
39 bool DIDescriptor::Verify() const {
40   return DbgNode &&
41          (DIDerivedType(DbgNode).Verify() ||
42           DICompositeType(DbgNode).Verify() || DIBasicType(DbgNode).Verify() ||
43           DIVariable(DbgNode).Verify() || DISubprogram(DbgNode).Verify() ||
44           DIGlobalVariable(DbgNode).Verify() || DIFile(DbgNode).Verify() ||
45           DICompileUnit(DbgNode).Verify() || DINameSpace(DbgNode).Verify() ||
46           DILexicalBlock(DbgNode).Verify() ||
47           DILexicalBlockFile(DbgNode).Verify() ||
48           DISubrange(DbgNode).Verify() || DIEnumerator(DbgNode).Verify() ||
49           DIObjCProperty(DbgNode).Verify() ||
50           DITemplateTypeParameter(DbgNode).Verify() ||
51           DITemplateValueParameter(DbgNode).Verify() ||
52           DIImportedEntity(DbgNode).Verify() || DIExpression(DbgNode).Verify());
53 }
54 
55 static Value *getField(const MDNode *DbgNode, unsigned Elt) {
56   if (!DbgNode || Elt >= DbgNode->getNumOperands())
57     return nullptr;
58   return DbgNode->getOperand(Elt);
59 }
60 
61 static MDNode *getNodeField(const MDNode *DbgNode, unsigned Elt) {
62   return dyn_cast_or_null<MDNode>(getField(DbgNode, Elt));
63 }
64 
65 static StringRef getStringField(const MDNode *DbgNode, unsigned Elt) {
66   if (MDString *MDS = dyn_cast_or_null<MDString>(getField(DbgNode, Elt)))
67     return MDS->getString();
68   return StringRef();
69 }
70 
71 StringRef DIDescriptor::getStringField(unsigned Elt) const {
72   return ::getStringField(DbgNode, Elt);
73 }
74 
75 uint64_t DIDescriptor::getUInt64Field(unsigned Elt) const {
76   if (!DbgNode)
77     return 0;
78 
79   if (Elt < DbgNode->getNumOperands())
80     if (ConstantInt *CI =
81             dyn_cast_or_null<ConstantInt>(DbgNode->getOperand(Elt)))
82       return CI->getZExtValue();
83 
84   return 0;
85 }
86 
87 int64_t DIDescriptor::getInt64Field(unsigned Elt) const {
88   if (!DbgNode)
89     return 0;
90 
91   if (Elt < DbgNode->getNumOperands())
92     if (ConstantInt *CI =
93             dyn_cast_or_null<ConstantInt>(DbgNode->getOperand(Elt)))
94       return CI->getSExtValue();
95 
96   return 0;
97 }
98 
99 DIDescriptor DIDescriptor::getDescriptorField(unsigned Elt) const {
100   MDNode *Field = getNodeField(DbgNode, Elt);
101   return DIDescriptor(Field);
102 }
103 
104 GlobalVariable *DIDescriptor::getGlobalVariableField(unsigned Elt) const {
105   if (!DbgNode)
106     return nullptr;
107 
108   if (Elt < DbgNode->getNumOperands())
109     return dyn_cast_or_null<GlobalVariable>(DbgNode->getOperand(Elt));
110   return nullptr;
111 }
112 
113 Constant *DIDescriptor::getConstantField(unsigned Elt) const {
114   if (!DbgNode)
115     return nullptr;
116 
117   if (Elt < DbgNode->getNumOperands())
118     return dyn_cast_or_null<Constant>(DbgNode->getOperand(Elt));
119   return nullptr;
120 }
121 
122 Function *DIDescriptor::getFunctionField(unsigned Elt) const {
123   if (!DbgNode)
124     return nullptr;
125 
126   if (Elt < DbgNode->getNumOperands())
127     return dyn_cast_or_null<Function>(DbgNode->getOperand(Elt));
128   return nullptr;
129 }
130 
131 void DIDescriptor::replaceFunctionField(unsigned Elt, Function *F) {
132   if (!DbgNode)
133     return;
134 
135   if (Elt < DbgNode->getNumOperands()) {
136     MDNode *Node = const_cast<MDNode *>(DbgNode);
137     Node->replaceOperandWith(Elt, F);
138   }
139 }
140 
141 static unsigned DIVariableInlinedAtIndex = 4;
142 MDNode *DIVariable::getInlinedAt() const {
143   return getNodeField(DbgNode, DIVariableInlinedAtIndex);
144 }
145 
146 /// \brief Return the size reported by the variable's type.
147 unsigned DIVariable::getSizeInBits(const DITypeIdentifierMap &Map) {
148   DIType Ty = getType().resolve(Map);
149   // Follow derived types until we reach a type that
150   // reports back a size.
151   while (Ty.isDerivedType() && !Ty.getSizeInBits()) {
152     DIDerivedType DT(&*Ty);
153     Ty = DT.getTypeDerivedFrom().resolve(Map);
154   }
155   assert(Ty.getSizeInBits() && "type with size 0");
156   return Ty.getSizeInBits();
157 }
158 
159 uint64_t DIExpression::getElement(unsigned Idx) const {
160   unsigned I = Idx + 1;
161   assert(I < getNumHeaderFields() &&
162          "non-existing complex address element requested");
163   return getHeaderFieldAs<int64_t>(I);
164 }
165 
166 bool DIExpression::isVariablePiece() const {
167   return getNumElements() && getElement(0) == dwarf::DW_OP_piece;
168 }
169 
170 uint64_t DIExpression::getPieceOffset() const {
171   assert(isVariablePiece());
172   return getElement(1);
173 }
174 
175 uint64_t DIExpression::getPieceSize() const {
176   assert(isVariablePiece());
177   return getElement(2);
178 }
179 
180 //===----------------------------------------------------------------------===//
181 // Predicates
182 //===----------------------------------------------------------------------===//
183 
184 bool DIDescriptor::isSubroutineType() const {
185   return isCompositeType() && getTag() == dwarf::DW_TAG_subroutine_type;
186 }
187 
188 bool DIDescriptor::isBasicType() const {
189   if (!DbgNode)
190     return false;
191   switch (getTag()) {
192   case dwarf::DW_TAG_base_type:
193   case dwarf::DW_TAG_unspecified_type:
194     return true;
195   default:
196     return false;
197   }
198 }
199 
200 bool DIDescriptor::isDerivedType() const {
201   if (!DbgNode)
202     return false;
203   switch (getTag()) {
204   case dwarf::DW_TAG_typedef:
205   case dwarf::DW_TAG_pointer_type:
206   case dwarf::DW_TAG_ptr_to_member_type:
207   case dwarf::DW_TAG_reference_type:
208   case dwarf::DW_TAG_rvalue_reference_type:
209   case dwarf::DW_TAG_const_type:
210   case dwarf::DW_TAG_volatile_type:
211   case dwarf::DW_TAG_restrict_type:
212   case dwarf::DW_TAG_member:
213   case dwarf::DW_TAG_inheritance:
214   case dwarf::DW_TAG_friend:
215     return true;
216   default:
217     // CompositeTypes are currently modelled as DerivedTypes.
218     return isCompositeType();
219   }
220 }
221 
222 bool DIDescriptor::isCompositeType() const {
223   if (!DbgNode)
224     return false;
225   switch (getTag()) {
226   case dwarf::DW_TAG_array_type:
227   case dwarf::DW_TAG_structure_type:
228   case dwarf::DW_TAG_union_type:
229   case dwarf::DW_TAG_enumeration_type:
230   case dwarf::DW_TAG_subroutine_type:
231   case dwarf::DW_TAG_class_type:
232     return true;
233   default:
234     return false;
235   }
236 }
237 
238 bool DIDescriptor::isVariable() const {
239   if (!DbgNode)
240     return false;
241   switch (getTag()) {
242   case dwarf::DW_TAG_auto_variable:
243   case dwarf::DW_TAG_arg_variable:
244     return true;
245   default:
246     return false;
247   }
248 }
249 
250 bool DIDescriptor::isType() const {
251   return isBasicType() || isCompositeType() || isDerivedType();
252 }
253 
254 bool DIDescriptor::isSubprogram() const {
255   return DbgNode && getTag() == dwarf::DW_TAG_subprogram;
256 }
257 
258 bool DIDescriptor::isGlobalVariable() const {
259   return DbgNode && (getTag() == dwarf::DW_TAG_variable ||
260                      getTag() == dwarf::DW_TAG_constant);
261 }
262 
263 bool DIDescriptor::isScope() const {
264   if (!DbgNode)
265     return false;
266   switch (getTag()) {
267   case dwarf::DW_TAG_compile_unit:
268   case dwarf::DW_TAG_lexical_block:
269   case dwarf::DW_TAG_subprogram:
270   case dwarf::DW_TAG_namespace:
271   case dwarf::DW_TAG_file_type:
272     return true;
273   default:
274     break;
275   }
276   return isType();
277 }
278 
279 bool DIDescriptor::isTemplateTypeParameter() const {
280   return DbgNode && getTag() == dwarf::DW_TAG_template_type_parameter;
281 }
282 
283 bool DIDescriptor::isTemplateValueParameter() const {
284   return DbgNode && (getTag() == dwarf::DW_TAG_template_value_parameter ||
285                      getTag() == dwarf::DW_TAG_GNU_template_template_param ||
286                      getTag() == dwarf::DW_TAG_GNU_template_parameter_pack);
287 }
288 
289 bool DIDescriptor::isCompileUnit() const {
290   return DbgNode && getTag() == dwarf::DW_TAG_compile_unit;
291 }
292 
293 bool DIDescriptor::isFile() const {
294   return DbgNode && getTag() == dwarf::DW_TAG_file_type;
295 }
296 
297 bool DIDescriptor::isNameSpace() const {
298   return DbgNode && getTag() == dwarf::DW_TAG_namespace;
299 }
300 
301 bool DIDescriptor::isLexicalBlockFile() const {
302   return DbgNode && getTag() == dwarf::DW_TAG_lexical_block &&
303          DbgNode->getNumOperands() == 3 && getNumHeaderFields() == 2;
304 }
305 
306 bool DIDescriptor::isLexicalBlock() const {
307   // FIXME: There are always exactly 4 header fields in DILexicalBlock, but
308   // something relies on this returning true for DILexicalBlockFile.
309   return DbgNode && getTag() == dwarf::DW_TAG_lexical_block &&
310          DbgNode->getNumOperands() == 3 &&
311          (getNumHeaderFields() == 2 || getNumHeaderFields() == 4);
312 }
313 
314 bool DIDescriptor::isSubrange() const {
315   return DbgNode && getTag() == dwarf::DW_TAG_subrange_type;
316 }
317 
318 bool DIDescriptor::isEnumerator() const {
319   return DbgNode && getTag() == dwarf::DW_TAG_enumerator;
320 }
321 
322 bool DIDescriptor::isObjCProperty() const {
323   return DbgNode && getTag() == dwarf::DW_TAG_APPLE_property;
324 }
325 
326 bool DIDescriptor::isImportedEntity() const {
327   return DbgNode && (getTag() == dwarf::DW_TAG_imported_module ||
328                      getTag() == dwarf::DW_TAG_imported_declaration);
329 }
330 
331 bool DIDescriptor::isExpression() const {
332   return DbgNode && (getTag() == dwarf::DW_TAG_expression);
333 }
334 
335 //===----------------------------------------------------------------------===//
336 // Simple Descriptor Constructors and other Methods
337 //===----------------------------------------------------------------------===//
338 
339 void DIDescriptor::replaceAllUsesWith(LLVMContext &VMContext, DIDescriptor D) {
340 
341   assert(DbgNode && "Trying to replace an unverified type!");
342 
343   // Since we use a TrackingVH for the node, its easy for clients to manufacture
344   // legitimate situations where they want to replaceAllUsesWith() on something
345   // which, due to uniquing, has merged with the source. We shield clients from
346   // this detail by allowing a value to be replaced with replaceAllUsesWith()
347   // itself.
348   const MDNode *DN = D;
349   if (DbgNode == DN) {
350     SmallVector<Value*, 10> Ops(DbgNode->getNumOperands());
351     for (size_t i = 0; i != Ops.size(); ++i)
352       Ops[i] = DbgNode->getOperand(i);
353     DN = MDNode::get(VMContext, Ops);
354   }
355 
356   MDNode *Node = const_cast<MDNode *>(DbgNode);
357   const Value *V = cast_or_null<Value>(DN);
358   Node->replaceAllUsesWith(const_cast<Value *>(V));
359   MDNode::deleteTemporary(Node);
360   DbgNode = DN;
361 }
362 
363 void DIDescriptor::replaceAllUsesWith(MDNode *D) {
364 
365   assert(DbgNode && "Trying to replace an unverified type!");
366   assert(DbgNode != D && "This replacement should always happen");
367   MDNode *Node = const_cast<MDNode *>(DbgNode);
368   const MDNode *DN = D;
369   const Value *V = cast_or_null<Value>(DN);
370   Node->replaceAllUsesWith(const_cast<Value *>(V));
371   MDNode::deleteTemporary(Node);
372 }
373 
374 bool DICompileUnit::Verify() const {
375   if (!isCompileUnit())
376     return false;
377 
378   // Don't bother verifying the compilation directory or producer string
379   // as those could be empty.
380   if (getFilename().empty())
381     return false;
382 
383   return DbgNode->getNumOperands() == 7 && getNumHeaderFields() == 8;
384 }
385 
386 bool DIObjCProperty::Verify() const {
387   if (!isObjCProperty())
388     return false;
389 
390   // Don't worry about the rest of the strings for now.
391   return DbgNode->getNumOperands() == 3 && getNumHeaderFields() == 6;
392 }
393 
394 /// \brief Check if a field at position Elt of a MDNode is a MDNode.
395 ///
396 /// We currently allow an empty string and an integer.
397 /// But we don't allow a non-empty string in a MDNode field.
398 static bool fieldIsMDNode(const MDNode *DbgNode, unsigned Elt) {
399   // FIXME: This function should return true, if the field is null or the field
400   // is indeed a MDNode: return !Fld || isa<MDNode>(Fld).
401   Value *Fld = getField(DbgNode, Elt);
402   if (Fld && isa<MDString>(Fld) && !cast<MDString>(Fld)->getString().empty())
403     return false;
404   return true;
405 }
406 
407 /// \brief Check if a field at position Elt of a MDNode is a MDString.
408 static bool fieldIsMDString(const MDNode *DbgNode, unsigned Elt) {
409   Value *Fld = getField(DbgNode, Elt);
410   return !Fld || isa<MDString>(Fld);
411 }
412 
413 /// \brief Check if a value can be a reference to a type.
414 static bool isTypeRef(const Value *Val) {
415   return !Val ||
416          (isa<MDString>(Val) && !cast<MDString>(Val)->getString().empty()) ||
417          (isa<MDNode>(Val) && DIType(cast<MDNode>(Val)).isType());
418 }
419 
420 /// \brief Check if referenced field might be a type.
421 static bool fieldIsTypeRef(const MDNode *DbgNode, unsigned Elt) {
422   Value *Fld = getField(DbgNode, Elt);
423   return isTypeRef(Fld);
424 }
425 
426 /// \brief Check if a value can be a ScopeRef.
427 static bool isScopeRef(const Value *Val) {
428   return !Val ||
429     (isa<MDString>(Val) && !cast<MDString>(Val)->getString().empty()) ||
430     // Not checking for Val->isScope() here, because it would work
431     // only for lexical scopes and not all subclasses of DIScope.
432     isa<MDNode>(Val);
433 }
434 
435 /// \brief Check if a field at position Elt of a MDNode can be a ScopeRef.
436 static bool fieldIsScopeRef(const MDNode *DbgNode, unsigned Elt) {
437   Value *Fld = getField(DbgNode, Elt);
438   return isScopeRef(Fld);
439 }
440 
441 bool DIType::Verify() const {
442   if (!isType())
443     return false;
444   // Make sure Context @ field 2 is MDNode.
445   if (!fieldIsScopeRef(DbgNode, 2))
446     return false;
447 
448   // FIXME: Sink this into the various subclass verifies.
449   uint16_t Tag = getTag();
450   if (!isBasicType() && Tag != dwarf::DW_TAG_const_type &&
451       Tag != dwarf::DW_TAG_volatile_type && Tag != dwarf::DW_TAG_pointer_type &&
452       Tag != dwarf::DW_TAG_ptr_to_member_type &&
453       Tag != dwarf::DW_TAG_reference_type &&
454       Tag != dwarf::DW_TAG_rvalue_reference_type &&
455       Tag != dwarf::DW_TAG_restrict_type && Tag != dwarf::DW_TAG_array_type &&
456       Tag != dwarf::DW_TAG_enumeration_type &&
457       Tag != dwarf::DW_TAG_subroutine_type &&
458       Tag != dwarf::DW_TAG_inheritance && Tag != dwarf::DW_TAG_friend &&
459       getFilename().empty())
460     return false;
461 
462   // DIType is abstract, it should be a BasicType, a DerivedType or
463   // a CompositeType.
464   if (isBasicType())
465     return DIBasicType(DbgNode).Verify();
466   else if (isCompositeType())
467     return DICompositeType(DbgNode).Verify();
468   else if (isDerivedType())
469     return DIDerivedType(DbgNode).Verify();
470   else
471     return false;
472 }
473 
474 bool DIBasicType::Verify() const {
475   return isBasicType() && DbgNode->getNumOperands() == 3 &&
476          getNumHeaderFields() == 8;
477 }
478 
479 bool DIDerivedType::Verify() const {
480   // Make sure DerivedFrom @ field 3 is TypeRef.
481   if (!fieldIsTypeRef(DbgNode, 3))
482     return false;
483   if (getTag() == dwarf::DW_TAG_ptr_to_member_type)
484     // Make sure ClassType @ field 4 is a TypeRef.
485     if (!fieldIsTypeRef(DbgNode, 4))
486       return false;
487 
488   return isDerivedType() && DbgNode->getNumOperands() >= 4 &&
489          DbgNode->getNumOperands() <= 8 && getNumHeaderFields() >= 7 &&
490          getNumHeaderFields() <= 8;
491 }
492 
493 bool DICompositeType::Verify() const {
494   if (!isCompositeType())
495     return false;
496 
497   // Make sure DerivedFrom @ field 3 and ContainingType @ field 5 are TypeRef.
498   if (!fieldIsTypeRef(DbgNode, 3))
499     return false;
500   if (!fieldIsTypeRef(DbgNode, 5))
501     return false;
502 
503   // Make sure the type identifier at field 7 is MDString, it can be null.
504   if (!fieldIsMDString(DbgNode, 7))
505     return false;
506 
507   // A subroutine type can't be both & and &&.
508   if (isLValueReference() && isRValueReference())
509     return false;
510 
511   return DbgNode->getNumOperands() == 8 && getNumHeaderFields() == 8;
512 }
513 
514 bool DISubprogram::Verify() const {
515   if (!isSubprogram())
516     return false;
517 
518   // Make sure context @ field 2 is a ScopeRef and type @ field 3 is a MDNode.
519   if (!fieldIsScopeRef(DbgNode, 2))
520     return false;
521   if (!fieldIsMDNode(DbgNode, 3))
522     return false;
523   // Containing type @ field 4.
524   if (!fieldIsTypeRef(DbgNode, 4))
525     return false;
526 
527   // A subprogram can't be both & and &&.
528   if (isLValueReference() && isRValueReference())
529     return false;
530 
531   // If a DISubprogram has an llvm::Function*, then scope chains from all
532   // instructions within the function should lead to this DISubprogram.
533   if (auto *F = getFunction()) {
534     LLVMContext &Ctxt = F->getContext();
535     for (auto &BB : *F) {
536       for (auto &I : BB) {
537         DebugLoc DL = I.getDebugLoc();
538         if (DL.isUnknown())
539           continue;
540 
541         MDNode *Scope = nullptr;
542         MDNode *IA = nullptr;
543         // walk the inlined-at scopes
544         while (DL.getScopeAndInlinedAt(Scope, IA, F->getContext()), IA)
545           DL = DebugLoc::getFromDILocation(IA);
546         DL.getScopeAndInlinedAt(Scope, IA, Ctxt);
547         assert(!IA);
548         while (!DIDescriptor(Scope).isSubprogram()) {
549           DILexicalBlockFile D(Scope);
550           Scope = D.isLexicalBlockFile()
551                       ? D.getScope()
552                       : DebugLoc::getFromDILexicalBlock(Scope).getScope(Ctxt);
553         }
554         if (!DISubprogram(Scope).describes(F))
555           return false;
556       }
557     }
558   }
559   return DbgNode->getNumOperands() == 9 && getNumHeaderFields() == 12;
560 }
561 
562 bool DIGlobalVariable::Verify() const {
563   if (!isGlobalVariable())
564     return false;
565 
566   if (getDisplayName().empty())
567     return false;
568   // Make sure context @ field 1 is an MDNode.
569   if (!fieldIsMDNode(DbgNode, 1))
570     return false;
571   // Make sure that type @ field 3 is a DITypeRef.
572   if (!fieldIsTypeRef(DbgNode, 3))
573     return false;
574   // Make sure StaticDataMemberDeclaration @ field 5 is MDNode.
575   if (!fieldIsMDNode(DbgNode, 5))
576     return false;
577 
578   return DbgNode->getNumOperands() == 6 && getNumHeaderFields() == 7;
579 }
580 
581 bool DIVariable::Verify() const {
582   if (!isVariable())
583     return false;
584 
585   // Make sure context @ field 1 is an MDNode.
586   if (!fieldIsMDNode(DbgNode, 1))
587     return false;
588   // Make sure that type @ field 3 is a DITypeRef.
589   if (!fieldIsTypeRef(DbgNode, 3))
590     return false;
591 
592   // Check the number of header fields, which is common between complex and
593   // simple variables.
594   if (getNumHeaderFields() != 4)
595     return false;
596 
597   // Variable without an inline location.
598   if (DbgNode->getNumOperands() == 4)
599     return true;
600 
601   // Variable with an inline location.
602   return getInlinedAt() != nullptr && DbgNode->getNumOperands() == 5;
603 }
604 
605 bool DIExpression::Verify() const {
606   // Empty DIExpressions may be represented as a nullptr.
607   if (!DbgNode)
608     return true;
609 
610   return isExpression() && DbgNode->getNumOperands() == 1;
611 }
612 
613 bool DILocation::Verify() const {
614   if (!DbgNode)
615     return false;
616 
617   return DbgNode->getNumOperands() == 4;
618 }
619 
620 bool DINameSpace::Verify() const {
621   if (!isNameSpace())
622     return false;
623   return DbgNode->getNumOperands() == 3 && getNumHeaderFields() == 3;
624 }
625 
626 MDNode *DIFile::getFileNode() const { return getNodeField(DbgNode, 1); }
627 
628 bool DIFile::Verify() const {
629   return isFile() && DbgNode->getNumOperands() == 2;
630 }
631 
632 bool DIEnumerator::Verify() const {
633   return isEnumerator() && DbgNode->getNumOperands() == 1 &&
634          getNumHeaderFields() == 3;
635 }
636 
637 bool DISubrange::Verify() const {
638   return isSubrange() && DbgNode->getNumOperands() == 1 &&
639          getNumHeaderFields() == 3;
640 }
641 
642 bool DILexicalBlock::Verify() const {
643   return isLexicalBlock() && DbgNode->getNumOperands() == 3 &&
644          getNumHeaderFields() == 4;
645 }
646 
647 bool DILexicalBlockFile::Verify() const {
648   return isLexicalBlockFile() && DbgNode->getNumOperands() == 3 &&
649          getNumHeaderFields() == 2;
650 }
651 
652 bool DITemplateTypeParameter::Verify() const {
653   return isTemplateTypeParameter() && DbgNode->getNumOperands() == 4 &&
654          getNumHeaderFields() == 4;
655 }
656 
657 bool DITemplateValueParameter::Verify() const {
658   return isTemplateValueParameter() && DbgNode->getNumOperands() == 5 &&
659          getNumHeaderFields() == 4;
660 }
661 
662 bool DIImportedEntity::Verify() const {
663   return isImportedEntity() && DbgNode->getNumOperands() == 3 &&
664          getNumHeaderFields() == 3;
665 }
666 
667 MDNode *DIDerivedType::getObjCProperty() const {
668   return getNodeField(DbgNode, 4);
669 }
670 
671 MDString *DICompositeType::getIdentifier() const {
672   return cast_or_null<MDString>(getField(DbgNode, 7));
673 }
674 
675 #ifndef NDEBUG
676 static void VerifySubsetOf(const MDNode *LHS, const MDNode *RHS) {
677   for (unsigned i = 0; i != LHS->getNumOperands(); ++i) {
678     // Skip the 'empty' list (that's a single i32 0, rather than truly empty).
679     if (i == 0 && isa<ConstantInt>(LHS->getOperand(i)))
680       continue;
681     const MDNode *E = cast<MDNode>(LHS->getOperand(i));
682     bool found = false;
683     for (unsigned j = 0; !found && j != RHS->getNumOperands(); ++j)
684       found = E == RHS->getOperand(j);
685     assert(found && "Losing a member during member list replacement");
686   }
687 }
688 #endif
689 
690 void DICompositeType::setArraysHelper(MDNode *Elements, MDNode *TParams) {
691   TrackingVH<MDNode> N(*this);
692   if (Elements) {
693 #ifndef NDEBUG
694     // Check that the new list of members contains all the old members as well.
695     if (const MDNode *El = cast_or_null<MDNode>(N->getOperand(4)))
696       VerifySubsetOf(El, Elements);
697 #endif
698     N->replaceOperandWith(4, Elements);
699   }
700   if (TParams)
701     N->replaceOperandWith(6, TParams);
702   DbgNode = N;
703 }
704 
705 DIScopeRef DIScope::getRef() const {
706   if (!isCompositeType())
707     return DIScopeRef(*this);
708   DICompositeType DTy(DbgNode);
709   if (!DTy.getIdentifier())
710     return DIScopeRef(*this);
711   return DIScopeRef(DTy.getIdentifier());
712 }
713 
714 void DICompositeType::setContainingType(DICompositeType ContainingType) {
715   TrackingVH<MDNode> N(*this);
716   N->replaceOperandWith(5, ContainingType.getRef());
717   DbgNode = N;
718 }
719 
720 bool DIVariable::isInlinedFnArgument(const Function *CurFn) {
721   assert(CurFn && "Invalid function");
722   if (!getContext().isSubprogram())
723     return false;
724   // This variable is not inlined function argument if its scope
725   // does not describe current function.
726   return !DISubprogram(getContext()).describes(CurFn);
727 }
728 
729 bool DISubprogram::describes(const Function *F) {
730   assert(F && "Invalid function");
731   if (F == getFunction())
732     return true;
733   StringRef Name = getLinkageName();
734   if (Name.empty())
735     Name = getName();
736   if (F->getName() == Name)
737     return true;
738   return false;
739 }
740 
741 MDNode *DISubprogram::getVariablesNodes() const {
742   return getNodeField(DbgNode, 8);
743 }
744 
745 DIArray DISubprogram::getVariables() const {
746   return DIArray(getNodeField(DbgNode, 8));
747 }
748 
749 Value *DITemplateValueParameter::getValue() const {
750   return getField(DbgNode, 3);
751 }
752 
753 DIScopeRef DIScope::getContext() const {
754 
755   if (isType())
756     return DIType(DbgNode).getContext();
757 
758   if (isSubprogram())
759     return DIScopeRef(DISubprogram(DbgNode).getContext());
760 
761   if (isLexicalBlock())
762     return DIScopeRef(DILexicalBlock(DbgNode).getContext());
763 
764   if (isLexicalBlockFile())
765     return DIScopeRef(DILexicalBlockFile(DbgNode).getContext());
766 
767   if (isNameSpace())
768     return DIScopeRef(DINameSpace(DbgNode).getContext());
769 
770   assert((isFile() || isCompileUnit()) && "Unhandled type of scope.");
771   return DIScopeRef(nullptr);
772 }
773 
774 StringRef DIScope::getName() const {
775   if (isType())
776     return DIType(DbgNode).getName();
777   if (isSubprogram())
778     return DISubprogram(DbgNode).getName();
779   if (isNameSpace())
780     return DINameSpace(DbgNode).getName();
781   assert((isLexicalBlock() || isLexicalBlockFile() || isFile() ||
782           isCompileUnit()) &&
783          "Unhandled type of scope.");
784   return StringRef();
785 }
786 
787 StringRef DIScope::getFilename() const {
788   if (!DbgNode)
789     return StringRef();
790   return ::getStringField(getNodeField(DbgNode, 1), 0);
791 }
792 
793 StringRef DIScope::getDirectory() const {
794   if (!DbgNode)
795     return StringRef();
796   return ::getStringField(getNodeField(DbgNode, 1), 1);
797 }
798 
799 DIArray DICompileUnit::getEnumTypes() const {
800   if (!DbgNode || DbgNode->getNumOperands() < 7)
801     return DIArray();
802 
803   return DIArray(getNodeField(DbgNode, 2));
804 }
805 
806 DIArray DICompileUnit::getRetainedTypes() const {
807   if (!DbgNode || DbgNode->getNumOperands() < 7)
808     return DIArray();
809 
810   return DIArray(getNodeField(DbgNode, 3));
811 }
812 
813 DIArray DICompileUnit::getSubprograms() const {
814   if (!DbgNode || DbgNode->getNumOperands() < 7)
815     return DIArray();
816 
817   return DIArray(getNodeField(DbgNode, 4));
818 }
819 
820 DIArray DICompileUnit::getGlobalVariables() const {
821   if (!DbgNode || DbgNode->getNumOperands() < 7)
822     return DIArray();
823 
824   return DIArray(getNodeField(DbgNode, 5));
825 }
826 
827 DIArray DICompileUnit::getImportedEntities() const {
828   if (!DbgNode || DbgNode->getNumOperands() < 7)
829     return DIArray();
830 
831   return DIArray(getNodeField(DbgNode, 6));
832 }
833 
834 void DICompileUnit::replaceSubprograms(DIArray Subprograms) {
835   assert(Verify() && "Expected compile unit");
836   if (Subprograms == getSubprograms())
837     return;
838 
839   const_cast<MDNode *>(DbgNode)->replaceOperandWith(4, Subprograms);
840 }
841 
842 void DICompileUnit::replaceGlobalVariables(DIArray GlobalVariables) {
843   assert(Verify() && "Expected compile unit");
844   if (GlobalVariables == getGlobalVariables())
845     return;
846 
847   const_cast<MDNode *>(DbgNode)->replaceOperandWith(5, GlobalVariables);
848 }
849 
850 DILocation DILocation::copyWithNewScope(LLVMContext &Ctx,
851                                         DILexicalBlockFile NewScope) {
852   SmallVector<Value *, 10> Elts;
853   assert(Verify());
854   for (unsigned I = 0; I < DbgNode->getNumOperands(); ++I) {
855     if (I != 2)
856       Elts.push_back(DbgNode->getOperand(I));
857     else
858       Elts.push_back(NewScope);
859   }
860   MDNode *NewDIL = MDNode::get(Ctx, Elts);
861   return DILocation(NewDIL);
862 }
863 
864 unsigned DILocation::computeNewDiscriminator(LLVMContext &Ctx) {
865   std::pair<const char *, unsigned> Key(getFilename().data(), getLineNumber());
866   return ++Ctx.pImpl->DiscriminatorTable[Key];
867 }
868 
869 DIVariable llvm::createInlinedVariable(MDNode *DV, MDNode *InlinedScope,
870                                        LLVMContext &VMContext) {
871   assert(DIVariable(DV).Verify() && "Expected a DIVariable");
872   if (!InlinedScope)
873     return cleanseInlinedVariable(DV, VMContext);
874 
875   // Insert inlined scope.
876   SmallVector<Value *, 8> Elts;
877   for (unsigned I = 0, E = DIVariableInlinedAtIndex; I != E; ++I)
878     Elts.push_back(DV->getOperand(I));
879   Elts.push_back(InlinedScope);
880 
881   DIVariable Inlined(MDNode::get(VMContext, Elts));
882   assert(Inlined.Verify() && "Expected to create a DIVariable");
883   return Inlined;
884 }
885 
886 DIVariable llvm::cleanseInlinedVariable(MDNode *DV, LLVMContext &VMContext) {
887   assert(DIVariable(DV).Verify() && "Expected a DIVariable");
888   if (!DIVariable(DV).getInlinedAt())
889     return DIVariable(DV);
890 
891   // Remove inlined scope.
892   SmallVector<Value *, 8> Elts;
893   for (unsigned I = 0, E = DIVariableInlinedAtIndex; I != E; ++I)
894     Elts.push_back(DV->getOperand(I));
895 
896   DIVariable Cleansed(MDNode::get(VMContext, Elts));
897   assert(Cleansed.Verify() && "Expected to create a DIVariable");
898   return Cleansed;
899 }
900 
901 DISubprogram llvm::getDISubprogram(const MDNode *Scope) {
902   DIDescriptor D(Scope);
903   if (D.isSubprogram())
904     return DISubprogram(Scope);
905 
906   if (D.isLexicalBlockFile())
907     return getDISubprogram(DILexicalBlockFile(Scope).getContext());
908 
909   if (D.isLexicalBlock())
910     return getDISubprogram(DILexicalBlock(Scope).getContext());
911 
912   return DISubprogram();
913 }
914 
915 DICompositeType llvm::getDICompositeType(DIType T) {
916   if (T.isCompositeType())
917     return DICompositeType(T);
918 
919   if (T.isDerivedType()) {
920     // This function is currently used by dragonegg and dragonegg does
921     // not generate identifier for types, so using an empty map to resolve
922     // DerivedFrom should be fine.
923     DITypeIdentifierMap EmptyMap;
924     return getDICompositeType(
925         DIDerivedType(T).getTypeDerivedFrom().resolve(EmptyMap));
926   }
927 
928   return DICompositeType();
929 }
930 
931 DITypeIdentifierMap
932 llvm::generateDITypeIdentifierMap(const NamedMDNode *CU_Nodes) {
933   DITypeIdentifierMap Map;
934   for (unsigned CUi = 0, CUe = CU_Nodes->getNumOperands(); CUi != CUe; ++CUi) {
935     DICompileUnit CU(CU_Nodes->getOperand(CUi));
936     DIArray Retain = CU.getRetainedTypes();
937     for (unsigned Ti = 0, Te = Retain.getNumElements(); Ti != Te; ++Ti) {
938       if (!Retain.getElement(Ti).isCompositeType())
939         continue;
940       DICompositeType Ty(Retain.getElement(Ti));
941       if (MDString *TypeId = Ty.getIdentifier()) {
942         // Definition has priority over declaration.
943         // Try to insert (TypeId, Ty) to Map.
944         std::pair<DITypeIdentifierMap::iterator, bool> P =
945             Map.insert(std::make_pair(TypeId, Ty));
946         // If TypeId already exists in Map and this is a definition, replace
947         // whatever we had (declaration or definition) with the definition.
948         if (!P.second && !Ty.isForwardDecl())
949           P.first->second = Ty;
950       }
951     }
952   }
953   return Map;
954 }
955 
956 //===----------------------------------------------------------------------===//
957 // DebugInfoFinder implementations.
958 //===----------------------------------------------------------------------===//
959 
960 void DebugInfoFinder::reset() {
961   CUs.clear();
962   SPs.clear();
963   GVs.clear();
964   TYs.clear();
965   Scopes.clear();
966   NodesSeen.clear();
967   TypeIdentifierMap.clear();
968   TypeMapInitialized = false;
969 }
970 
971 void DebugInfoFinder::InitializeTypeMap(const Module &M) {
972   if (!TypeMapInitialized)
973     if (NamedMDNode *CU_Nodes = M.getNamedMetadata("llvm.dbg.cu")) {
974       TypeIdentifierMap = generateDITypeIdentifierMap(CU_Nodes);
975       TypeMapInitialized = true;
976     }
977 }
978 
979 void DebugInfoFinder::processModule(const Module &M) {
980   InitializeTypeMap(M);
981   if (NamedMDNode *CU_Nodes = M.getNamedMetadata("llvm.dbg.cu")) {
982     for (unsigned i = 0, e = CU_Nodes->getNumOperands(); i != e; ++i) {
983       DICompileUnit CU(CU_Nodes->getOperand(i));
984       addCompileUnit(CU);
985       DIArray GVs = CU.getGlobalVariables();
986       for (unsigned i = 0, e = GVs.getNumElements(); i != e; ++i) {
987         DIGlobalVariable DIG(GVs.getElement(i));
988         if (addGlobalVariable(DIG)) {
989           processScope(DIG.getContext());
990           processType(DIG.getType().resolve(TypeIdentifierMap));
991         }
992       }
993       DIArray SPs = CU.getSubprograms();
994       for (unsigned i = 0, e = SPs.getNumElements(); i != e; ++i)
995         processSubprogram(DISubprogram(SPs.getElement(i)));
996       DIArray EnumTypes = CU.getEnumTypes();
997       for (unsigned i = 0, e = EnumTypes.getNumElements(); i != e; ++i)
998         processType(DIType(EnumTypes.getElement(i)));
999       DIArray RetainedTypes = CU.getRetainedTypes();
1000       for (unsigned i = 0, e = RetainedTypes.getNumElements(); i != e; ++i)
1001         processType(DIType(RetainedTypes.getElement(i)));
1002       DIArray Imports = CU.getImportedEntities();
1003       for (unsigned i = 0, e = Imports.getNumElements(); i != e; ++i) {
1004         DIImportedEntity Import = DIImportedEntity(Imports.getElement(i));
1005         DIDescriptor Entity = Import.getEntity().resolve(TypeIdentifierMap);
1006         if (Entity.isType())
1007           processType(DIType(Entity));
1008         else if (Entity.isSubprogram())
1009           processSubprogram(DISubprogram(Entity));
1010         else if (Entity.isNameSpace())
1011           processScope(DINameSpace(Entity).getContext());
1012       }
1013     }
1014   }
1015 }
1016 
1017 void DebugInfoFinder::processLocation(const Module &M, DILocation Loc) {
1018   if (!Loc)
1019     return;
1020   InitializeTypeMap(M);
1021   processScope(Loc.getScope());
1022   processLocation(M, Loc.getOrigLocation());
1023 }
1024 
1025 void DebugInfoFinder::processType(DIType DT) {
1026   if (!addType(DT))
1027     return;
1028   processScope(DT.getContext().resolve(TypeIdentifierMap));
1029   if (DT.isCompositeType()) {
1030     DICompositeType DCT(DT);
1031     processType(DCT.getTypeDerivedFrom().resolve(TypeIdentifierMap));
1032     if (DT.isSubroutineType()) {
1033       DITypeArray DTA = DISubroutineType(DT).getTypeArray();
1034       for (unsigned i = 0, e = DTA.getNumElements(); i != e; ++i)
1035         processType(DTA.getElement(i).resolve(TypeIdentifierMap));
1036       return;
1037     }
1038     DIArray DA = DCT.getElements();
1039     for (unsigned i = 0, e = DA.getNumElements(); i != e; ++i) {
1040       DIDescriptor D = DA.getElement(i);
1041       if (D.isType())
1042         processType(DIType(D));
1043       else if (D.isSubprogram())
1044         processSubprogram(DISubprogram(D));
1045     }
1046   } else if (DT.isDerivedType()) {
1047     DIDerivedType DDT(DT);
1048     processType(DDT.getTypeDerivedFrom().resolve(TypeIdentifierMap));
1049   }
1050 }
1051 
1052 void DebugInfoFinder::processScope(DIScope Scope) {
1053   if (Scope.isType()) {
1054     DIType Ty(Scope);
1055     processType(Ty);
1056     return;
1057   }
1058   if (Scope.isCompileUnit()) {
1059     addCompileUnit(DICompileUnit(Scope));
1060     return;
1061   }
1062   if (Scope.isSubprogram()) {
1063     processSubprogram(DISubprogram(Scope));
1064     return;
1065   }
1066   if (!addScope(Scope))
1067     return;
1068   if (Scope.isLexicalBlock()) {
1069     DILexicalBlock LB(Scope);
1070     processScope(LB.getContext());
1071   } else if (Scope.isLexicalBlockFile()) {
1072     DILexicalBlockFile LBF = DILexicalBlockFile(Scope);
1073     processScope(LBF.getScope());
1074   } else if (Scope.isNameSpace()) {
1075     DINameSpace NS(Scope);
1076     processScope(NS.getContext());
1077   }
1078 }
1079 
1080 void DebugInfoFinder::processSubprogram(DISubprogram SP) {
1081   if (!addSubprogram(SP))
1082     return;
1083   processScope(SP.getContext().resolve(TypeIdentifierMap));
1084   processType(SP.getType());
1085   DIArray TParams = SP.getTemplateParams();
1086   for (unsigned I = 0, E = TParams.getNumElements(); I != E; ++I) {
1087     DIDescriptor Element = TParams.getElement(I);
1088     if (Element.isTemplateTypeParameter()) {
1089       DITemplateTypeParameter TType(Element);
1090       processScope(TType.getContext().resolve(TypeIdentifierMap));
1091       processType(TType.getType().resolve(TypeIdentifierMap));
1092     } else if (Element.isTemplateValueParameter()) {
1093       DITemplateValueParameter TVal(Element);
1094       processScope(TVal.getContext().resolve(TypeIdentifierMap));
1095       processType(TVal.getType().resolve(TypeIdentifierMap));
1096     }
1097   }
1098 }
1099 
1100 void DebugInfoFinder::processDeclare(const Module &M,
1101                                      const DbgDeclareInst *DDI) {
1102   MDNode *N = dyn_cast<MDNode>(DDI->getVariable());
1103   if (!N)
1104     return;
1105   InitializeTypeMap(M);
1106 
1107   DIDescriptor DV(N);
1108   if (!DV.isVariable())
1109     return;
1110 
1111   if (!NodesSeen.insert(DV))
1112     return;
1113   processScope(DIVariable(N).getContext());
1114   processType(DIVariable(N).getType().resolve(TypeIdentifierMap));
1115 }
1116 
1117 void DebugInfoFinder::processValue(const Module &M, const DbgValueInst *DVI) {
1118   MDNode *N = dyn_cast<MDNode>(DVI->getVariable());
1119   if (!N)
1120     return;
1121   InitializeTypeMap(M);
1122 
1123   DIDescriptor DV(N);
1124   if (!DV.isVariable())
1125     return;
1126 
1127   if (!NodesSeen.insert(DV))
1128     return;
1129   processScope(DIVariable(N).getContext());
1130   processType(DIVariable(N).getType().resolve(TypeIdentifierMap));
1131 }
1132 
1133 bool DebugInfoFinder::addType(DIType DT) {
1134   if (!DT)
1135     return false;
1136 
1137   if (!NodesSeen.insert(DT))
1138     return false;
1139 
1140   TYs.push_back(DT);
1141   return true;
1142 }
1143 
1144 bool DebugInfoFinder::addCompileUnit(DICompileUnit CU) {
1145   if (!CU)
1146     return false;
1147   if (!NodesSeen.insert(CU))
1148     return false;
1149 
1150   CUs.push_back(CU);
1151   return true;
1152 }
1153 
1154 bool DebugInfoFinder::addGlobalVariable(DIGlobalVariable DIG) {
1155   if (!DIG)
1156     return false;
1157 
1158   if (!NodesSeen.insert(DIG))
1159     return false;
1160 
1161   GVs.push_back(DIG);
1162   return true;
1163 }
1164 
1165 bool DebugInfoFinder::addSubprogram(DISubprogram SP) {
1166   if (!SP)
1167     return false;
1168 
1169   if (!NodesSeen.insert(SP))
1170     return false;
1171 
1172   SPs.push_back(SP);
1173   return true;
1174 }
1175 
1176 bool DebugInfoFinder::addScope(DIScope Scope) {
1177   if (!Scope)
1178     return false;
1179   // FIXME: Ocaml binding generates a scope with no content, we treat it
1180   // as null for now.
1181   if (Scope->getNumOperands() == 0)
1182     return false;
1183   if (!NodesSeen.insert(Scope))
1184     return false;
1185   Scopes.push_back(Scope);
1186   return true;
1187 }
1188 
1189 //===----------------------------------------------------------------------===//
1190 // DIDescriptor: dump routines for all descriptors.
1191 //===----------------------------------------------------------------------===//
1192 
1193 void DIDescriptor::dump() const {
1194   print(dbgs());
1195   dbgs() << '\n';
1196 }
1197 
1198 void DIDescriptor::print(raw_ostream &OS) const {
1199   if (!DbgNode)
1200     return;
1201 
1202   if (const char *Tag = dwarf::TagString(getTag()))
1203     OS << "[ " << Tag << " ]";
1204 
1205   if (this->isSubrange()) {
1206     DISubrange(DbgNode).printInternal(OS);
1207   } else if (this->isCompileUnit()) {
1208     DICompileUnit(DbgNode).printInternal(OS);
1209   } else if (this->isFile()) {
1210     DIFile(DbgNode).printInternal(OS);
1211   } else if (this->isEnumerator()) {
1212     DIEnumerator(DbgNode).printInternal(OS);
1213   } else if (this->isBasicType()) {
1214     DIType(DbgNode).printInternal(OS);
1215   } else if (this->isDerivedType()) {
1216     DIDerivedType(DbgNode).printInternal(OS);
1217   } else if (this->isCompositeType()) {
1218     DICompositeType(DbgNode).printInternal(OS);
1219   } else if (this->isSubprogram()) {
1220     DISubprogram(DbgNode).printInternal(OS);
1221   } else if (this->isGlobalVariable()) {
1222     DIGlobalVariable(DbgNode).printInternal(OS);
1223   } else if (this->isVariable()) {
1224     DIVariable(DbgNode).printInternal(OS);
1225   } else if (this->isObjCProperty()) {
1226     DIObjCProperty(DbgNode).printInternal(OS);
1227   } else if (this->isNameSpace()) {
1228     DINameSpace(DbgNode).printInternal(OS);
1229   } else if (this->isScope()) {
1230     DIScope(DbgNode).printInternal(OS);
1231   } else if (this->isExpression()) {
1232     DIExpression(DbgNode).printInternal(OS);
1233   }
1234 }
1235 
1236 void DISubrange::printInternal(raw_ostream &OS) const {
1237   int64_t Count = getCount();
1238   if (Count != -1)
1239     OS << " [" << getLo() << ", " << Count - 1 << ']';
1240   else
1241     OS << " [unbounded]";
1242 }
1243 
1244 void DIScope::printInternal(raw_ostream &OS) const {
1245   OS << " [" << getDirectory() << "/" << getFilename() << ']';
1246 }
1247 
1248 void DICompileUnit::printInternal(raw_ostream &OS) const {
1249   DIScope::printInternal(OS);
1250   OS << " [";
1251   unsigned Lang = getLanguage();
1252   if (const char *LangStr = dwarf::LanguageString(Lang))
1253     OS << LangStr;
1254   else
1255     (OS << "lang 0x").write_hex(Lang);
1256   OS << ']';
1257 }
1258 
1259 void DIEnumerator::printInternal(raw_ostream &OS) const {
1260   OS << " [" << getName() << " :: " << getEnumValue() << ']';
1261 }
1262 
1263 void DIType::printInternal(raw_ostream &OS) const {
1264   if (!DbgNode)
1265     return;
1266 
1267   StringRef Res = getName();
1268   if (!Res.empty())
1269     OS << " [" << Res << "]";
1270 
1271   // TODO: Print context?
1272 
1273   OS << " [line " << getLineNumber() << ", size " << getSizeInBits()
1274      << ", align " << getAlignInBits() << ", offset " << getOffsetInBits();
1275   if (isBasicType())
1276     if (const char *Enc =
1277             dwarf::AttributeEncodingString(DIBasicType(DbgNode).getEncoding()))
1278       OS << ", enc " << Enc;
1279   OS << "]";
1280 
1281   if (isPrivate())
1282     OS << " [private]";
1283   else if (isProtected())
1284     OS << " [protected]";
1285   else if (isPublic())
1286     OS << " [public]";
1287 
1288   if (isArtificial())
1289     OS << " [artificial]";
1290 
1291   if (isForwardDecl())
1292     OS << " [decl]";
1293   else if (getTag() == dwarf::DW_TAG_structure_type ||
1294            getTag() == dwarf::DW_TAG_union_type ||
1295            getTag() == dwarf::DW_TAG_enumeration_type ||
1296            getTag() == dwarf::DW_TAG_class_type)
1297     OS << " [def]";
1298   if (isVector())
1299     OS << " [vector]";
1300   if (isStaticMember())
1301     OS << " [static]";
1302 
1303   if (isLValueReference())
1304     OS << " [reference]";
1305 
1306   if (isRValueReference())
1307     OS << " [rvalue reference]";
1308 }
1309 
1310 void DIDerivedType::printInternal(raw_ostream &OS) const {
1311   DIType::printInternal(OS);
1312   OS << " [from " << getTypeDerivedFrom().getName() << ']';
1313 }
1314 
1315 void DICompositeType::printInternal(raw_ostream &OS) const {
1316   DIType::printInternal(OS);
1317   DIArray A = getElements();
1318   OS << " [" << A.getNumElements() << " elements]";
1319 }
1320 
1321 void DINameSpace::printInternal(raw_ostream &OS) const {
1322   StringRef Name = getName();
1323   if (!Name.empty())
1324     OS << " [" << Name << ']';
1325 
1326   OS << " [line " << getLineNumber() << ']';
1327 }
1328 
1329 void DISubprogram::printInternal(raw_ostream &OS) const {
1330   // TODO : Print context
1331   OS << " [line " << getLineNumber() << ']';
1332 
1333   if (isLocalToUnit())
1334     OS << " [local]";
1335 
1336   if (isDefinition())
1337     OS << " [def]";
1338 
1339   if (getScopeLineNumber() != getLineNumber())
1340     OS << " [scope " << getScopeLineNumber() << "]";
1341 
1342   if (isPrivate())
1343     OS << " [private]";
1344   else if (isProtected())
1345     OS << " [protected]";
1346   else if (isPublic())
1347     OS << " [public]";
1348 
1349   if (isLValueReference())
1350     OS << " [reference]";
1351 
1352   if (isRValueReference())
1353     OS << " [rvalue reference]";
1354 
1355   StringRef Res = getName();
1356   if (!Res.empty())
1357     OS << " [" << Res << ']';
1358 }
1359 
1360 void DIGlobalVariable::printInternal(raw_ostream &OS) const {
1361   StringRef Res = getName();
1362   if (!Res.empty())
1363     OS << " [" << Res << ']';
1364 
1365   OS << " [line " << getLineNumber() << ']';
1366 
1367   // TODO : Print context
1368 
1369   if (isLocalToUnit())
1370     OS << " [local]";
1371 
1372   if (isDefinition())
1373     OS << " [def]";
1374 }
1375 
1376 void DIVariable::printInternal(raw_ostream &OS) const {
1377   StringRef Res = getName();
1378   if (!Res.empty())
1379     OS << " [" << Res << ']';
1380 
1381   OS << " [line " << getLineNumber() << ']';
1382 }
1383 
1384 void DIExpression::printInternal(raw_ostream &OS) const {
1385   for (unsigned I = 0; I < getNumElements(); ++I) {
1386     uint64_t OpCode = getElement(I);
1387     OS << " [" << OperationEncodingString(OpCode);
1388     switch (OpCode) {
1389     case DW_OP_plus: {
1390       OS << " " << getElement(++I);
1391       break;
1392     }
1393     case DW_OP_piece: {
1394       unsigned Offset = getElement(++I);
1395       unsigned Size = getElement(++I);
1396       OS << " offset=" << Offset << ", size=" << Size;
1397       break;
1398     }
1399     default:
1400       // Else bail out early. This may be a line table entry.
1401       OS << "Unknown]";
1402       return;
1403     }
1404     OS << "]";
1405   }
1406 }
1407 
1408 void DIObjCProperty::printInternal(raw_ostream &OS) const {
1409   StringRef Name = getObjCPropertyName();
1410   if (!Name.empty())
1411     OS << " [" << Name << ']';
1412 
1413   OS << " [line " << getLineNumber() << ", properties " << getUnsignedField(6)
1414      << ']';
1415 }
1416 
1417 static void printDebugLoc(DebugLoc DL, raw_ostream &CommentOS,
1418                           const LLVMContext &Ctx) {
1419   if (!DL.isUnknown()) { // Print source line info.
1420     DIScope Scope(DL.getScope(Ctx));
1421     assert(Scope.isScope() && "Scope of a DebugLoc should be a DIScope.");
1422     // Omit the directory, because it's likely to be long and uninteresting.
1423     CommentOS << Scope.getFilename();
1424     CommentOS << ':' << DL.getLine();
1425     if (DL.getCol() != 0)
1426       CommentOS << ':' << DL.getCol();
1427     DebugLoc InlinedAtDL = DebugLoc::getFromDILocation(DL.getInlinedAt(Ctx));
1428     if (!InlinedAtDL.isUnknown()) {
1429       CommentOS << " @[ ";
1430       printDebugLoc(InlinedAtDL, CommentOS, Ctx);
1431       CommentOS << " ]";
1432     }
1433   }
1434 }
1435 
1436 void DIVariable::printExtendedName(raw_ostream &OS) const {
1437   const LLVMContext &Ctx = DbgNode->getContext();
1438   StringRef Res = getName();
1439   if (!Res.empty())
1440     OS << Res << "," << getLineNumber();
1441   if (MDNode *InlinedAt = getInlinedAt()) {
1442     DebugLoc InlinedAtDL = DebugLoc::getFromDILocation(InlinedAt);
1443     if (!InlinedAtDL.isUnknown()) {
1444       OS << " @[";
1445       printDebugLoc(InlinedAtDL, OS, Ctx);
1446       OS << "]";
1447     }
1448   }
1449 }
1450 
1451 template <> DIRef<DIScope>::DIRef(const Value *V) : Val(V) {
1452   assert(isScopeRef(V) && "DIScopeRef should be a MDString or MDNode");
1453 }
1454 template <> DIRef<DIType>::DIRef(const Value *V) : Val(V) {
1455   assert(isTypeRef(V) && "DITypeRef should be a MDString or MDNode");
1456 }
1457 
1458 template <>
1459 DIScopeRef DIDescriptor::getFieldAs<DIScopeRef>(unsigned Elt) const {
1460   return DIScopeRef(getField(DbgNode, Elt));
1461 }
1462 template <> DITypeRef DIDescriptor::getFieldAs<DITypeRef>(unsigned Elt) const {
1463   return DITypeRef(getField(DbgNode, Elt));
1464 }
1465 
1466 bool llvm::StripDebugInfo(Module &M) {
1467   bool Changed = false;
1468 
1469   // Remove all of the calls to the debugger intrinsics, and remove them from
1470   // the module.
1471   if (Function *Declare = M.getFunction("llvm.dbg.declare")) {
1472     while (!Declare->use_empty()) {
1473       CallInst *CI = cast<CallInst>(Declare->user_back());
1474       CI->eraseFromParent();
1475     }
1476     Declare->eraseFromParent();
1477     Changed = true;
1478   }
1479 
1480   if (Function *DbgVal = M.getFunction("llvm.dbg.value")) {
1481     while (!DbgVal->use_empty()) {
1482       CallInst *CI = cast<CallInst>(DbgVal->user_back());
1483       CI->eraseFromParent();
1484     }
1485     DbgVal->eraseFromParent();
1486     Changed = true;
1487   }
1488 
1489   for (Module::named_metadata_iterator NMI = M.named_metadata_begin(),
1490          NME = M.named_metadata_end(); NMI != NME;) {
1491     NamedMDNode *NMD = NMI;
1492     ++NMI;
1493     if (NMD->getName().startswith("llvm.dbg.")) {
1494       NMD->eraseFromParent();
1495       Changed = true;
1496     }
1497   }
1498 
1499   for (Module::iterator MI = M.begin(), ME = M.end(); MI != ME; ++MI)
1500     for (Function::iterator FI = MI->begin(), FE = MI->end(); FI != FE;
1501          ++FI)
1502       for (BasicBlock::iterator BI = FI->begin(), BE = FI->end(); BI != BE;
1503            ++BI) {
1504         if (!BI->getDebugLoc().isUnknown()) {
1505           Changed = true;
1506           BI->setDebugLoc(DebugLoc());
1507         }
1508       }
1509 
1510   return Changed;
1511 }
1512 
1513 unsigned llvm::getDebugMetadataVersionFromModule(const Module &M) {
1514   Value *Val = M.getModuleFlag("Debug Info Version");
1515   if (!Val)
1516     return 0;
1517   return cast<ConstantInt>(Val)->getZExtValue();
1518 }
1519 
1520 llvm::DenseMap<const llvm::Function *, llvm::DISubprogram>
1521 llvm::makeSubprogramMap(const Module &M) {
1522   DenseMap<const Function *, DISubprogram> R;
1523 
1524   NamedMDNode *CU_Nodes = M.getNamedMetadata("llvm.dbg.cu");
1525   if (!CU_Nodes)
1526     return R;
1527 
1528   for (MDNode *N : CU_Nodes->operands()) {
1529     DICompileUnit CUNode(N);
1530     DIArray SPs = CUNode.getSubprograms();
1531     for (unsigned i = 0, e = SPs.getNumElements(); i != e; ++i) {
1532       DISubprogram SP(SPs.getElement(i));
1533       if (Function *F = SP.getFunction())
1534         R.insert(std::make_pair(F, SP));
1535     }
1536   }
1537   return R;
1538 }
1539