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      1 //===- DebugInfo.h - Debug Information Helpers ------------------*- C++ -*-===//
      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 defines a bunch of datatypes that are useful for creating and
     11 // walking debug info in LLVM IR form. They essentially provide wrappers around
     12 // the information in the global variables that's needed when constructing the
     13 // DWARF information.
     14 //
     15 //===----------------------------------------------------------------------===//
     16 
     17 #ifndef LLVM_IR_DEBUGINFO_H
     18 #define LLVM_IR_DEBUGINFO_H
     19 
     20 #include "llvm/ADT/DenseMap.h"
     21 #include "llvm/ADT/iterator_range.h"
     22 #include "llvm/ADT/SmallPtrSet.h"
     23 #include "llvm/ADT/SmallVector.h"
     24 #include "llvm/ADT/StringRef.h"
     25 #include "llvm/IR/Metadata.h"
     26 #include "llvm/Support/Casting.h"
     27 #include "llvm/Support/Dwarf.h"
     28 
     29 namespace llvm {
     30 class BasicBlock;
     31 class Constant;
     32 class Function;
     33 class GlobalVariable;
     34 class Module;
     35 class Type;
     36 class Value;
     37 class DbgDeclareInst;
     38 class DbgValueInst;
     39 class Instruction;
     40 class MDNode;
     41 class MDString;
     42 class NamedMDNode;
     43 class LLVMContext;
     44 class raw_ostream;
     45 
     46 class DIFile;
     47 class DISubprogram;
     48 class DILexicalBlock;
     49 class DILexicalBlockFile;
     50 class DIVariable;
     51 class DIType;
     52 class DIScope;
     53 class DIObjCProperty;
     54 
     55 /// Maps from type identifier to the actual MDNode.
     56 typedef DenseMap<const MDString *, MDNode *> DITypeIdentifierMap;
     57 
     58 /// DIDescriptor - A thin wraper around MDNode to access encoded debug info.
     59 /// This should not be stored in a container, because the underlying MDNode
     60 /// may change in certain situations.
     61 class DIDescriptor {
     62   // Befriends DIRef so DIRef can befriend the protected member
     63   // function: getFieldAs<DIRef>.
     64   template <typename T> friend class DIRef;
     65 
     66 public:
     67   enum {
     68     FlagPrivate           = 1 << 0,
     69     FlagProtected         = 1 << 1,
     70     FlagFwdDecl           = 1 << 2,
     71     FlagAppleBlock        = 1 << 3,
     72     FlagBlockByrefStruct  = 1 << 4,
     73     FlagVirtual           = 1 << 5,
     74     FlagArtificial        = 1 << 6,
     75     FlagExplicit          = 1 << 7,
     76     FlagPrototyped        = 1 << 8,
     77     FlagObjcClassComplete = 1 << 9,
     78     FlagObjectPointer     = 1 << 10,
     79     FlagVector            = 1 << 11,
     80     FlagStaticMember      = 1 << 12,
     81     FlagIndirectVariable  = 1 << 13,
     82     FlagLValueReference   = 1 << 14,
     83     FlagRValueReference   = 1 << 15
     84   };
     85 
     86 protected:
     87   const MDNode *DbgNode;
     88 
     89   StringRef getStringField(unsigned Elt) const;
     90   unsigned getUnsignedField(unsigned Elt) const {
     91     return (unsigned)getUInt64Field(Elt);
     92   }
     93   uint64_t getUInt64Field(unsigned Elt) const;
     94   int64_t getInt64Field(unsigned Elt) const;
     95   DIDescriptor getDescriptorField(unsigned Elt) const;
     96 
     97   template <typename DescTy> DescTy getFieldAs(unsigned Elt) const {
     98     return DescTy(getDescriptorField(Elt));
     99   }
    100 
    101   GlobalVariable *getGlobalVariableField(unsigned Elt) const;
    102   Constant *getConstantField(unsigned Elt) const;
    103   Function *getFunctionField(unsigned Elt) const;
    104   void replaceFunctionField(unsigned Elt, Function *F);
    105 
    106 public:
    107   explicit DIDescriptor(const MDNode *N = nullptr) : DbgNode(N) {}
    108 
    109   bool Verify() const;
    110 
    111   operator MDNode *() const { return const_cast<MDNode *>(DbgNode); }
    112   MDNode *operator->() const { return const_cast<MDNode *>(DbgNode); }
    113 
    114   // An explicit operator bool so that we can do testing of DI values
    115   // easily.
    116   // FIXME: This operator bool isn't actually protecting anything at the
    117   // moment due to the conversion operator above making DIDescriptor nodes
    118   // implicitly convertable to bool.
    119   LLVM_EXPLICIT operator bool() const { return DbgNode != nullptr; }
    120 
    121   bool operator==(DIDescriptor Other) const { return DbgNode == Other.DbgNode; }
    122   bool operator!=(DIDescriptor Other) const { return !operator==(Other); }
    123 
    124   uint16_t getTag() const {
    125     return getUnsignedField(0) & ~LLVMDebugVersionMask;
    126   }
    127 
    128   bool isDerivedType() const;
    129   bool isCompositeType() const;
    130   bool isBasicType() const;
    131   bool isVariable() const;
    132   bool isSubprogram() const;
    133   bool isGlobalVariable() const;
    134   bool isScope() const;
    135   bool isFile() const;
    136   bool isCompileUnit() const;
    137   bool isNameSpace() const;
    138   bool isLexicalBlockFile() const;
    139   bool isLexicalBlock() const;
    140   bool isSubrange() const;
    141   bool isEnumerator() const;
    142   bool isType() const;
    143   bool isUnspecifiedParameter() const;
    144   bool isTemplateTypeParameter() const;
    145   bool isTemplateValueParameter() const;
    146   bool isObjCProperty() const;
    147   bool isImportedEntity() const;
    148 
    149   /// print - print descriptor.
    150   void print(raw_ostream &OS) const;
    151 
    152   /// dump - print descriptor to dbgs() with a newline.
    153   void dump() const;
    154 };
    155 
    156 /// DISubrange - This is used to represent ranges, for array bounds.
    157 class DISubrange : public DIDescriptor {
    158   friend class DIDescriptor;
    159   void printInternal(raw_ostream &OS) const;
    160 
    161 public:
    162   explicit DISubrange(const MDNode *N = nullptr) : DIDescriptor(N) {}
    163 
    164   int64_t getLo() const { return getInt64Field(1); }
    165   int64_t getCount() const { return getInt64Field(2); }
    166   bool Verify() const;
    167 };
    168 
    169 /// DIArray - This descriptor holds an array of descriptors.
    170 class DIArray : public DIDescriptor {
    171 public:
    172   explicit DIArray(const MDNode *N = nullptr) : DIDescriptor(N) {}
    173 
    174   unsigned getNumElements() const;
    175   DIDescriptor getElement(unsigned Idx) const {
    176     return getDescriptorField(Idx);
    177   }
    178 };
    179 
    180 /// DIEnumerator - A wrapper for an enumerator (e.g. X and Y in 'enum {X,Y}').
    181 /// FIXME: it seems strange that this doesn't have either a reference to the
    182 /// type/precision or a file/line pair for location info.
    183 class DIEnumerator : public DIDescriptor {
    184   friend class DIDescriptor;
    185   void printInternal(raw_ostream &OS) const;
    186 
    187 public:
    188   explicit DIEnumerator(const MDNode *N = nullptr) : DIDescriptor(N) {}
    189 
    190   StringRef getName() const { return getStringField(1); }
    191   int64_t getEnumValue() const { return getInt64Field(2); }
    192   bool Verify() const;
    193 };
    194 
    195 template <typename T> class DIRef;
    196 typedef DIRef<DIScope> DIScopeRef;
    197 typedef DIRef<DIType> DITypeRef;
    198 
    199 /// DIScope - A base class for various scopes.
    200 ///
    201 /// Although, implementation-wise, DIScope is the parent class of most
    202 /// other DIxxx classes, including DIType and its descendants, most of
    203 /// DIScope's descendants are not a substitutable subtype of
    204 /// DIScope. The DIDescriptor::isScope() method only is true for
    205 /// DIScopes that are scopes in the strict lexical scope sense
    206 /// (DICompileUnit, DISubprogram, etc.), but not for, e.g., a DIType.
    207 class DIScope : public DIDescriptor {
    208 protected:
    209   friend class DIDescriptor;
    210   void printInternal(raw_ostream &OS) const;
    211 
    212 public:
    213   explicit DIScope(const MDNode *N = nullptr) : DIDescriptor(N) {}
    214 
    215   /// Gets the parent scope for this scope node or returns a
    216   /// default constructed scope.
    217   DIScopeRef getContext() const;
    218   /// If the scope node has a name, return that, else return an empty string.
    219   StringRef getName() const;
    220   StringRef getFilename() const;
    221   StringRef getDirectory() const;
    222 
    223   /// Generate a reference to this DIScope. Uses the type identifier instead
    224   /// of the actual MDNode if possible, to help type uniquing.
    225   DIScopeRef getRef() const;
    226 };
    227 
    228 /// Represents reference to a DIDescriptor, abstracts over direct and
    229 /// identifier-based metadata references.
    230 template <typename T> class DIRef {
    231   template <typename DescTy>
    232   friend DescTy DIDescriptor::getFieldAs(unsigned Elt) const;
    233   friend DIScopeRef DIScope::getContext() const;
    234   friend DIScopeRef DIScope::getRef() const;
    235   friend class DIType;
    236 
    237   /// Val can be either a MDNode or a MDString, in the latter,
    238   /// MDString specifies the type identifier.
    239   const Value *Val;
    240   explicit DIRef(const Value *V);
    241 
    242 public:
    243   T resolve(const DITypeIdentifierMap &Map) const;
    244   StringRef getName() const;
    245   operator Value *() const { return const_cast<Value *>(Val); }
    246 };
    247 
    248 template <typename T>
    249 T DIRef<T>::resolve(const DITypeIdentifierMap &Map) const {
    250   if (!Val)
    251     return T();
    252 
    253   if (const MDNode *MD = dyn_cast<MDNode>(Val))
    254     return T(MD);
    255 
    256   const MDString *MS = cast<MDString>(Val);
    257   // Find the corresponding MDNode.
    258   DITypeIdentifierMap::const_iterator Iter = Map.find(MS);
    259   assert(Iter != Map.end() && "Identifier not in the type map?");
    260   assert(DIDescriptor(Iter->second).isType() &&
    261          "MDNode in DITypeIdentifierMap should be a DIType.");
    262   return T(Iter->second);
    263 }
    264 
    265 template <typename T> StringRef DIRef<T>::getName() const {
    266   if (!Val)
    267     return StringRef();
    268 
    269   if (const MDNode *MD = dyn_cast<MDNode>(Val))
    270     return T(MD).getName();
    271 
    272   const MDString *MS = cast<MDString>(Val);
    273   return MS->getString();
    274 }
    275 
    276 /// Specialize getFieldAs to handle fields that are references to DIScopes.
    277 template <> DIScopeRef DIDescriptor::getFieldAs<DIScopeRef>(unsigned Elt) const;
    278 /// Specialize DIRef constructor for DIScopeRef.
    279 template <> DIRef<DIScope>::DIRef(const Value *V);
    280 
    281 /// Specialize getFieldAs to handle fields that are references to DITypes.
    282 template <> DITypeRef DIDescriptor::getFieldAs<DITypeRef>(unsigned Elt) const;
    283 /// Specialize DIRef constructor for DITypeRef.
    284 template <> DIRef<DIType>::DIRef(const Value *V);
    285 
    286 /// DIType - This is a wrapper for a type.
    287 /// FIXME: Types should be factored much better so that CV qualifiers and
    288 /// others do not require a huge and empty descriptor full of zeros.
    289 class DIType : public DIScope {
    290 protected:
    291   friend class DIDescriptor;
    292   void printInternal(raw_ostream &OS) const;
    293 
    294 public:
    295   explicit DIType(const MDNode *N = nullptr) : DIScope(N) {}
    296   operator DITypeRef () const {
    297     assert(isType() &&
    298            "constructing DITypeRef from an MDNode that is not a type");
    299     return DITypeRef(&*getRef());
    300   }
    301 
    302   /// Verify - Verify that a type descriptor is well formed.
    303   bool Verify() const;
    304 
    305   DIScopeRef getContext() const { return getFieldAs<DIScopeRef>(2); }
    306   StringRef getName() const { return getStringField(3); }
    307   unsigned getLineNumber() const { return getUnsignedField(4); }
    308   uint64_t getSizeInBits() const { return getUInt64Field(5); }
    309   uint64_t getAlignInBits() const { return getUInt64Field(6); }
    310   // FIXME: Offset is only used for DW_TAG_member nodes.  Making every type
    311   // carry this is just plain insane.
    312   uint64_t getOffsetInBits() const { return getUInt64Field(7); }
    313   unsigned getFlags() const { return getUnsignedField(8); }
    314   bool isPrivate() const { return (getFlags() & FlagPrivate) != 0; }
    315   bool isProtected() const { return (getFlags() & FlagProtected) != 0; }
    316   bool isForwardDecl() const { return (getFlags() & FlagFwdDecl) != 0; }
    317   // isAppleBlock - Return true if this is the Apple Blocks extension.
    318   bool isAppleBlockExtension() const {
    319     return (getFlags() & FlagAppleBlock) != 0;
    320   }
    321   bool isBlockByrefStruct() const {
    322     return (getFlags() & FlagBlockByrefStruct) != 0;
    323   }
    324   bool isVirtual() const { return (getFlags() & FlagVirtual) != 0; }
    325   bool isArtificial() const { return (getFlags() & FlagArtificial) != 0; }
    326   bool isObjectPointer() const { return (getFlags() & FlagObjectPointer) != 0; }
    327   bool isObjcClassComplete() const {
    328     return (getFlags() & FlagObjcClassComplete) != 0;
    329   }
    330   bool isVector() const { return (getFlags() & FlagVector) != 0; }
    331   bool isStaticMember() const { return (getFlags() & FlagStaticMember) != 0; }
    332   bool isLValueReference() const {
    333     return (getFlags() & FlagLValueReference) != 0;
    334   }
    335   bool isRValueReference() const {
    336     return (getFlags() & FlagRValueReference) != 0;
    337   }
    338   bool isValid() const { return DbgNode && isType(); }
    339 
    340   /// replaceAllUsesWith - Replace all uses of debug info referenced by
    341   /// this descriptor.
    342   void replaceAllUsesWith(LLVMContext &VMContext, DIDescriptor D);
    343   void replaceAllUsesWith(MDNode *D);
    344 };
    345 
    346 /// DIBasicType - A basic type, like 'int' or 'float'.
    347 class DIBasicType : public DIType {
    348 public:
    349   explicit DIBasicType(const MDNode *N = nullptr) : DIType(N) {}
    350 
    351   unsigned getEncoding() const { return getUnsignedField(9); }
    352 
    353   /// Verify - Verify that a basic type descriptor is well formed.
    354   bool Verify() const;
    355 };
    356 
    357 /// DIDerivedType - A simple derived type, like a const qualified type,
    358 /// a typedef, a pointer or reference, et cetera.  Or, a data member of
    359 /// a class/struct/union.
    360 class DIDerivedType : public DIType {
    361   friend class DIDescriptor;
    362   void printInternal(raw_ostream &OS) const;
    363 
    364 public:
    365   explicit DIDerivedType(const MDNode *N = nullptr) : DIType(N) {}
    366 
    367   DITypeRef getTypeDerivedFrom() const { return getFieldAs<DITypeRef>(9); }
    368 
    369   /// getObjCProperty - Return property node, if this ivar is
    370   /// associated with one.
    371   MDNode *getObjCProperty() const;
    372 
    373   DITypeRef getClassType() const {
    374     assert(getTag() == dwarf::DW_TAG_ptr_to_member_type);
    375     return getFieldAs<DITypeRef>(10);
    376   }
    377 
    378   Constant *getConstant() const {
    379     assert((getTag() == dwarf::DW_TAG_member) && isStaticMember());
    380     return getConstantField(10);
    381   }
    382 
    383   /// Verify - Verify that a derived type descriptor is well formed.
    384   bool Verify() const;
    385 };
    386 
    387 /// DICompositeType - This descriptor holds a type that can refer to multiple
    388 /// other types, like a function or struct.
    389 /// DICompositeType is derived from DIDerivedType because some
    390 /// composite types (such as enums) can be derived from basic types
    391 // FIXME: Make this derive from DIType directly & just store the
    392 // base type in a single DIType field.
    393 class DICompositeType : public DIDerivedType {
    394   friend class DIDescriptor;
    395   void printInternal(raw_ostream &OS) const;
    396 
    397 public:
    398   explicit DICompositeType(const MDNode *N = nullptr) : DIDerivedType(N) {}
    399 
    400   DIArray getTypeArray() const { return getFieldAs<DIArray>(10); }
    401   void setTypeArray(DIArray Elements, DIArray TParams = DIArray());
    402   unsigned getRunTimeLang() const { return getUnsignedField(11); }
    403   DITypeRef getContainingType() const { return getFieldAs<DITypeRef>(12); }
    404   void setContainingType(DICompositeType ContainingType);
    405   DIArray getTemplateParams() const { return getFieldAs<DIArray>(13); }
    406   MDString *getIdentifier() const;
    407 
    408   /// Verify - Verify that a composite type descriptor is well formed.
    409   bool Verify() const;
    410 };
    411 
    412 /// DIFile - This is a wrapper for a file.
    413 class DIFile : public DIScope {
    414   friend class DIDescriptor;
    415 
    416 public:
    417   explicit DIFile(const MDNode *N = nullptr) : DIScope(N) {}
    418   MDNode *getFileNode() const;
    419   bool Verify() const;
    420 };
    421 
    422 /// DICompileUnit - A wrapper for a compile unit.
    423 class DICompileUnit : public DIScope {
    424   friend class DIDescriptor;
    425   void printInternal(raw_ostream &OS) const;
    426 
    427 public:
    428   explicit DICompileUnit(const MDNode *N = nullptr) : DIScope(N) {}
    429 
    430   dwarf::SourceLanguage getLanguage() const {
    431     return static_cast<dwarf::SourceLanguage>(getUnsignedField(2));
    432   }
    433   StringRef getProducer() const { return getStringField(3); }
    434 
    435   bool isOptimized() const { return getUnsignedField(4) != 0; }
    436   StringRef getFlags() const { return getStringField(5); }
    437   unsigned getRunTimeVersion() const { return getUnsignedField(6); }
    438 
    439   DIArray getEnumTypes() const;
    440   DIArray getRetainedTypes() const;
    441   DIArray getSubprograms() const;
    442   DIArray getGlobalVariables() const;
    443   DIArray getImportedEntities() const;
    444 
    445   StringRef getSplitDebugFilename() const { return getStringField(12); }
    446   unsigned getEmissionKind() const { return getUnsignedField(13); }
    447 
    448   /// Verify - Verify that a compile unit is well formed.
    449   bool Verify() const;
    450 };
    451 
    452 /// DISubprogram - This is a wrapper for a subprogram (e.g. a function).
    453 class DISubprogram : public DIScope {
    454   friend class DIDescriptor;
    455   void printInternal(raw_ostream &OS) const;
    456 
    457 public:
    458   explicit DISubprogram(const MDNode *N = nullptr) : DIScope(N) {}
    459 
    460   DIScopeRef getContext() const { return getFieldAs<DIScopeRef>(2); }
    461   StringRef getName() const { return getStringField(3); }
    462   StringRef getDisplayName() const { return getStringField(4); }
    463   StringRef getLinkageName() const { return getStringField(5); }
    464   unsigned getLineNumber() const { return getUnsignedField(6); }
    465   DICompositeType getType() const { return getFieldAs<DICompositeType>(7); }
    466 
    467   /// isLocalToUnit - Return true if this subprogram is local to the current
    468   /// compile unit, like 'static' in C.
    469   unsigned isLocalToUnit() const { return getUnsignedField(8); }
    470   unsigned isDefinition() const { return getUnsignedField(9); }
    471 
    472   unsigned getVirtuality() const { return getUnsignedField(10); }
    473   unsigned getVirtualIndex() const { return getUnsignedField(11); }
    474 
    475   DITypeRef getContainingType() const { return getFieldAs<DITypeRef>(12); }
    476 
    477   unsigned getFlags() const { return getUnsignedField(13); }
    478 
    479   unsigned isArtificial() const {
    480     return (getUnsignedField(13) & FlagArtificial) != 0;
    481   }
    482   /// isPrivate - Return true if this subprogram has "private"
    483   /// access specifier.
    484   bool isPrivate() const { return (getUnsignedField(13) & FlagPrivate) != 0; }
    485   /// isProtected - Return true if this subprogram has "protected"
    486   /// access specifier.
    487   bool isProtected() const {
    488     return (getUnsignedField(13) & FlagProtected) != 0;
    489   }
    490   /// isExplicit - Return true if this subprogram is marked as explicit.
    491   bool isExplicit() const { return (getUnsignedField(13) & FlagExplicit) != 0; }
    492   /// isPrototyped - Return true if this subprogram is prototyped.
    493   bool isPrototyped() const {
    494     return (getUnsignedField(13) & FlagPrototyped) != 0;
    495   }
    496 
    497   /// Return true if this subprogram is a C++11 reference-qualified
    498   /// non-static member function (void foo() &).
    499   unsigned isLValueReference() const {
    500     return (getUnsignedField(13) & FlagLValueReference) != 0;
    501   }
    502 
    503   /// Return true if this subprogram is a C++11
    504   /// rvalue-reference-qualified non-static member function
    505   /// (void foo() &&).
    506   unsigned isRValueReference() const {
    507     return (getUnsignedField(13) & FlagRValueReference) != 0;
    508   }
    509 
    510   unsigned isOptimized() const;
    511 
    512   /// Verify - Verify that a subprogram descriptor is well formed.
    513   bool Verify() const;
    514 
    515   /// describes - Return true if this subprogram provides debugging
    516   /// information for the function F.
    517   bool describes(const Function *F);
    518 
    519   Function *getFunction() const { return getFunctionField(15); }
    520   void replaceFunction(Function *F) { replaceFunctionField(15, F); }
    521   DIArray getTemplateParams() const { return getFieldAs<DIArray>(16); }
    522   DISubprogram getFunctionDeclaration() const {
    523     return getFieldAs<DISubprogram>(17);
    524   }
    525   MDNode *getVariablesNodes() const;
    526   DIArray getVariables() const;
    527 
    528   /// getScopeLineNumber - Get the beginning of the scope of the
    529   /// function, not necessarily where the name of the program
    530   /// starts.
    531   unsigned getScopeLineNumber() const { return getUnsignedField(19); }
    532 };
    533 
    534 /// DILexicalBlock - This is a wrapper for a lexical block.
    535 class DILexicalBlock : public DIScope {
    536 public:
    537   explicit DILexicalBlock(const MDNode *N = nullptr) : DIScope(N) {}
    538   DIScope getContext() const { return getFieldAs<DIScope>(2); }
    539   unsigned getLineNumber() const { return getUnsignedField(3); }
    540   unsigned getColumnNumber() const { return getUnsignedField(4); }
    541   unsigned getDiscriminator() const { return getUnsignedField(5); }
    542   bool Verify() const;
    543 };
    544 
    545 /// DILexicalBlockFile - This is a wrapper for a lexical block with
    546 /// a filename change.
    547 class DILexicalBlockFile : public DIScope {
    548 public:
    549   explicit DILexicalBlockFile(const MDNode *N = nullptr) : DIScope(N) {}
    550   DIScope getContext() const {
    551     if (getScope().isSubprogram())
    552       return getScope();
    553     return getScope().getContext();
    554   }
    555   unsigned getLineNumber() const { return getScope().getLineNumber(); }
    556   unsigned getColumnNumber() const { return getScope().getColumnNumber(); }
    557   DILexicalBlock getScope() const { return getFieldAs<DILexicalBlock>(2); }
    558   bool Verify() const;
    559 };
    560 
    561 /// DINameSpace - A wrapper for a C++ style name space.
    562 class DINameSpace : public DIScope {
    563   friend class DIDescriptor;
    564   void printInternal(raw_ostream &OS) const;
    565 
    566 public:
    567   explicit DINameSpace(const MDNode *N = nullptr) : DIScope(N) {}
    568   DIScope getContext() const { return getFieldAs<DIScope>(2); }
    569   StringRef getName() const { return getStringField(3); }
    570   unsigned getLineNumber() const { return getUnsignedField(4); }
    571   bool Verify() const;
    572 };
    573 
    574 /// DIUnspecifiedParameter - This is a wrapper for unspecified parameters.
    575 class DIUnspecifiedParameter : public DIDescriptor {
    576 public:
    577   explicit DIUnspecifiedParameter(const MDNode *N = nullptr)
    578     : DIDescriptor(N) {}
    579   bool Verify() const;
    580 };
    581 
    582 /// DITemplateTypeParameter - This is a wrapper for template type parameter.
    583 class DITemplateTypeParameter : public DIDescriptor {
    584 public:
    585   explicit DITemplateTypeParameter(const MDNode *N = nullptr)
    586     : DIDescriptor(N) {}
    587 
    588   DIScopeRef getContext() const { return getFieldAs<DIScopeRef>(1); }
    589   StringRef getName() const { return getStringField(2); }
    590   DITypeRef getType() const { return getFieldAs<DITypeRef>(3); }
    591   StringRef getFilename() const { return getFieldAs<DIFile>(4).getFilename(); }
    592   StringRef getDirectory() const {
    593     return getFieldAs<DIFile>(4).getDirectory();
    594   }
    595   unsigned getLineNumber() const { return getUnsignedField(5); }
    596   unsigned getColumnNumber() const { return getUnsignedField(6); }
    597   bool Verify() const;
    598 };
    599 
    600 /// DITemplateValueParameter - This is a wrapper for template value parameter.
    601 class DITemplateValueParameter : public DIDescriptor {
    602 public:
    603   explicit DITemplateValueParameter(const MDNode *N = nullptr)
    604     : DIDescriptor(N) {}
    605 
    606   DIScopeRef getContext() const { return getFieldAs<DIScopeRef>(1); }
    607   StringRef getName() const { return getStringField(2); }
    608   DITypeRef getType() const { return getFieldAs<DITypeRef>(3); }
    609   Value *getValue() const;
    610   StringRef getFilename() const { return getFieldAs<DIFile>(5).getFilename(); }
    611   StringRef getDirectory() const {
    612     return getFieldAs<DIFile>(5).getDirectory();
    613   }
    614   unsigned getLineNumber() const { return getUnsignedField(6); }
    615   unsigned getColumnNumber() const { return getUnsignedField(7); }
    616   bool Verify() const;
    617 };
    618 
    619 /// DIGlobalVariable - This is a wrapper for a global variable.
    620 class DIGlobalVariable : public DIDescriptor {
    621   friend class DIDescriptor;
    622   void printInternal(raw_ostream &OS) const;
    623 
    624 public:
    625   explicit DIGlobalVariable(const MDNode *N = nullptr) : DIDescriptor(N) {}
    626 
    627   DIScope getContext() const { return getFieldAs<DIScope>(2); }
    628   StringRef getName() const { return getStringField(3); }
    629   StringRef getDisplayName() const { return getStringField(4); }
    630   StringRef getLinkageName() const { return getStringField(5); }
    631   StringRef getFilename() const { return getFieldAs<DIFile>(6).getFilename(); }
    632   StringRef getDirectory() const {
    633     return getFieldAs<DIFile>(6).getDirectory();
    634   }
    635 
    636   unsigned getLineNumber() const { return getUnsignedField(7); }
    637   DITypeRef getType() const { return getFieldAs<DITypeRef>(8); }
    638   unsigned isLocalToUnit() const { return getUnsignedField(9); }
    639   unsigned isDefinition() const { return getUnsignedField(10); }
    640 
    641   GlobalVariable *getGlobal() const { return getGlobalVariableField(11); }
    642   Constant *getConstant() const { return getConstantField(11); }
    643   DIDerivedType getStaticDataMemberDeclaration() const {
    644     return getFieldAs<DIDerivedType>(12);
    645   }
    646 
    647   /// Verify - Verify that a global variable descriptor is well formed.
    648   bool Verify() const;
    649 };
    650 
    651 /// DIVariable - This is a wrapper for a variable (e.g. parameter, local,
    652 /// global etc).
    653 class DIVariable : public DIDescriptor {
    654   friend class DIDescriptor;
    655   void printInternal(raw_ostream &OS) const;
    656 
    657 public:
    658   explicit DIVariable(const MDNode *N = nullptr) : DIDescriptor(N) {}
    659 
    660   DIScope getContext() const { return getFieldAs<DIScope>(1); }
    661   StringRef getName() const { return getStringField(2); }
    662   DIFile getFile() const { return getFieldAs<DIFile>(3); }
    663   unsigned getLineNumber() const { return (getUnsignedField(4) << 8) >> 8; }
    664   unsigned getArgNumber() const {
    665     unsigned L = getUnsignedField(4);
    666     return L >> 24;
    667   }
    668   DITypeRef getType() const { return getFieldAs<DITypeRef>(5); }
    669 
    670   /// isArtificial - Return true if this variable is marked as "artificial".
    671   bool isArtificial() const {
    672     return (getUnsignedField(6) & FlagArtificial) != 0;
    673   }
    674 
    675   bool isObjectPointer() const {
    676     return (getUnsignedField(6) & FlagObjectPointer) != 0;
    677   }
    678 
    679   /// \brief Return true if this variable is represented as a pointer.
    680   bool isIndirect() const {
    681     return (getUnsignedField(6) & FlagIndirectVariable) != 0;
    682   }
    683 
    684   /// getInlinedAt - If this variable is inlined then return inline location.
    685   MDNode *getInlinedAt() const;
    686 
    687   /// Verify - Verify that a variable descriptor is well formed.
    688   bool Verify() const;
    689 
    690   /// HasComplexAddr - Return true if the variable has a complex address.
    691   bool hasComplexAddress() const { return getNumAddrElements() > 0; }
    692 
    693   /// \brief Return the size of this variable's complex address or
    694   /// zero if there is none.
    695   unsigned getNumAddrElements() const {
    696     if (DbgNode->getNumOperands() < 9)
    697       return 0;
    698     return getDescriptorField(8)->getNumOperands();
    699   }
    700 
    701   /// \brief return the Idx'th complex address element.
    702   uint64_t getAddrElement(unsigned Idx) const;
    703 
    704   /// isBlockByrefVariable - Return true if the variable was declared as
    705   /// a "__block" variable (Apple Blocks).
    706   bool isBlockByrefVariable(const DITypeIdentifierMap &Map) const {
    707     return (getType().resolve(Map)).isBlockByrefStruct();
    708   }
    709 
    710   /// isInlinedFnArgument - Return true if this variable provides debugging
    711   /// information for an inlined function arguments.
    712   bool isInlinedFnArgument(const Function *CurFn);
    713 
    714   void printExtendedName(raw_ostream &OS) const;
    715 };
    716 
    717 /// DILocation - This object holds location information. This object
    718 /// is not associated with any DWARF tag.
    719 class DILocation : public DIDescriptor {
    720 public:
    721   explicit DILocation(const MDNode *N) : DIDescriptor(N) {}
    722 
    723   unsigned getLineNumber() const { return getUnsignedField(0); }
    724   unsigned getColumnNumber() const { return getUnsignedField(1); }
    725   DIScope getScope() const { return getFieldAs<DIScope>(2); }
    726   DILocation getOrigLocation() const { return getFieldAs<DILocation>(3); }
    727   StringRef getFilename() const { return getScope().getFilename(); }
    728   StringRef getDirectory() const { return getScope().getDirectory(); }
    729   bool Verify() const;
    730   bool atSameLineAs(const DILocation &Other) const {
    731     return (getLineNumber() == Other.getLineNumber() &&
    732             getFilename() == Other.getFilename());
    733   }
    734   /// getDiscriminator - DWARF discriminators are used to distinguish
    735   /// identical file locations for instructions that are on different
    736   /// basic blocks. If two instructions are inside the same lexical block
    737   /// and are in different basic blocks, we create a new lexical block
    738   /// with identical location as the original but with a different
    739   /// discriminator value (lib/Transforms/Util/AddDiscriminators.cpp
    740   /// for details).
    741   unsigned getDiscriminator() const {
    742     // Since discriminators are associated with lexical blocks, make
    743     // sure this location is a lexical block before retrieving its
    744     // value.
    745     return getScope().isLexicalBlock()
    746                ? getFieldAs<DILexicalBlock>(2).getDiscriminator()
    747                : 0;
    748   }
    749   unsigned computeNewDiscriminator(LLVMContext &Ctx);
    750   DILocation copyWithNewScope(LLVMContext &Ctx, DILexicalBlock NewScope);
    751 };
    752 
    753 class DIObjCProperty : public DIDescriptor {
    754   friend class DIDescriptor;
    755   void printInternal(raw_ostream &OS) const;
    756 
    757 public:
    758   explicit DIObjCProperty(const MDNode *N) : DIDescriptor(N) {}
    759 
    760   StringRef getObjCPropertyName() const { return getStringField(1); }
    761   DIFile getFile() const { return getFieldAs<DIFile>(2); }
    762   unsigned getLineNumber() const { return getUnsignedField(3); }
    763 
    764   StringRef getObjCPropertyGetterName() const { return getStringField(4); }
    765   StringRef getObjCPropertySetterName() const { return getStringField(5); }
    766   bool isReadOnlyObjCProperty() const {
    767     return (getUnsignedField(6) & dwarf::DW_APPLE_PROPERTY_readonly) != 0;
    768   }
    769   bool isReadWriteObjCProperty() const {
    770     return (getUnsignedField(6) & dwarf::DW_APPLE_PROPERTY_readwrite) != 0;
    771   }
    772   bool isAssignObjCProperty() const {
    773     return (getUnsignedField(6) & dwarf::DW_APPLE_PROPERTY_assign) != 0;
    774   }
    775   bool isRetainObjCProperty() const {
    776     return (getUnsignedField(6) & dwarf::DW_APPLE_PROPERTY_retain) != 0;
    777   }
    778   bool isCopyObjCProperty() const {
    779     return (getUnsignedField(6) & dwarf::DW_APPLE_PROPERTY_copy) != 0;
    780   }
    781   bool isNonAtomicObjCProperty() const {
    782     return (getUnsignedField(6) & dwarf::DW_APPLE_PROPERTY_nonatomic) != 0;
    783   }
    784 
    785   /// Objective-C doesn't have an ODR, so there is no benefit in storing
    786   /// the type as a DITypeRef here.
    787   DIType getType() const { return getFieldAs<DIType>(7); }
    788 
    789   /// Verify - Verify that a derived type descriptor is well formed.
    790   bool Verify() const;
    791 };
    792 
    793 /// \brief An imported module (C++ using directive or similar).
    794 class DIImportedEntity : public DIDescriptor {
    795   friend class DIDescriptor;
    796   void printInternal(raw_ostream &OS) const;
    797 
    798 public:
    799   explicit DIImportedEntity(const MDNode *N) : DIDescriptor(N) {}
    800   DIScope getContext() const { return getFieldAs<DIScope>(1); }
    801   DIScopeRef getEntity() const { return getFieldAs<DIScopeRef>(2); }
    802   unsigned getLineNumber() const { return getUnsignedField(3); }
    803   StringRef getName() const { return getStringField(4); }
    804   bool Verify() const;
    805 };
    806 
    807 /// getDISubprogram - Find subprogram that is enclosing this scope.
    808 DISubprogram getDISubprogram(const MDNode *Scope);
    809 
    810 /// getDICompositeType - Find underlying composite type.
    811 DICompositeType getDICompositeType(DIType T);
    812 
    813 /// getOrInsertFnSpecificMDNode - Return a NameMDNode that is suitable
    814 /// to hold function specific information.
    815 NamedMDNode *getOrInsertFnSpecificMDNode(Module &M, DISubprogram SP);
    816 
    817 /// getFnSpecificMDNode - Return a NameMDNode, if available, that is
    818 /// suitable to hold function specific information.
    819 NamedMDNode *getFnSpecificMDNode(const Module &M, DISubprogram SP);
    820 
    821 /// createInlinedVariable - Create a new inlined variable based on current
    822 /// variable.
    823 /// @param DV            Current Variable.
    824 /// @param InlinedScope  Location at current variable is inlined.
    825 DIVariable createInlinedVariable(MDNode *DV, MDNode *InlinedScope,
    826                                  LLVMContext &VMContext);
    827 
    828 /// cleanseInlinedVariable - Remove inlined scope from the variable.
    829 DIVariable cleanseInlinedVariable(MDNode *DV, LLVMContext &VMContext);
    830 
    831 /// Construct DITypeIdentifierMap by going through retained types of each CU.
    832 DITypeIdentifierMap generateDITypeIdentifierMap(const NamedMDNode *CU_Nodes);
    833 
    834 /// Strip debug info in the module if it exists.
    835 /// To do this, we remove all calls to the debugger intrinsics and any named
    836 /// metadata for debugging. We also remove debug locations for instructions.
    837 /// Return true if module is modified.
    838 bool StripDebugInfo(Module &M);
    839 
    840 /// Return Debug Info Metadata Version by checking module flags.
    841 unsigned getDebugMetadataVersionFromModule(const Module &M);
    842 
    843 /// DebugInfoFinder tries to list all debug info MDNodes used in a module. To
    844 /// list debug info MDNodes used by an instruction, DebugInfoFinder uses
    845 /// processDeclare, processValue and processLocation to handle DbgDeclareInst,
    846 /// DbgValueInst and DbgLoc attached to instructions. processModule will go
    847 /// through all DICompileUnits in llvm.dbg.cu and list debug info MDNodes
    848 /// used by the CUs.
    849 class DebugInfoFinder {
    850 public:
    851   DebugInfoFinder() : TypeMapInitialized(false) {}
    852 
    853   /// processModule - Process entire module and collect debug info
    854   /// anchors.
    855   void processModule(const Module &M);
    856 
    857   /// processDeclare - Process DbgDeclareInst.
    858   void processDeclare(const Module &M, const DbgDeclareInst *DDI);
    859   /// Process DbgValueInst.
    860   void processValue(const Module &M, const DbgValueInst *DVI);
    861   /// processLocation - Process DILocation.
    862   void processLocation(const Module &M, DILocation Loc);
    863 
    864   /// Clear all lists.
    865   void reset();
    866 
    867 private:
    868   /// Initialize TypeIdentifierMap.
    869   void InitializeTypeMap(const Module &M);
    870 
    871   /// processType - Process DIType.
    872   void processType(DIType DT);
    873 
    874   /// processSubprogram - Process DISubprogram.
    875   void processSubprogram(DISubprogram SP);
    876 
    877   void processScope(DIScope Scope);
    878 
    879   /// addCompileUnit - Add compile unit into CUs.
    880   bool addCompileUnit(DICompileUnit CU);
    881 
    882   /// addGlobalVariable - Add global variable into GVs.
    883   bool addGlobalVariable(DIGlobalVariable DIG);
    884 
    885   // addSubprogram - Add subprogram into SPs.
    886   bool addSubprogram(DISubprogram SP);
    887 
    888   /// addType - Add type into Tys.
    889   bool addType(DIType DT);
    890 
    891   bool addScope(DIScope Scope);
    892 
    893 public:
    894   typedef SmallVectorImpl<DICompileUnit>::const_iterator compile_unit_iterator;
    895   typedef SmallVectorImpl<DISubprogram>::const_iterator subprogram_iterator;
    896   typedef SmallVectorImpl<DIGlobalVariable>::const_iterator global_variable_iterator;
    897   typedef SmallVectorImpl<DIType>::const_iterator type_iterator;
    898   typedef SmallVectorImpl<DIScope>::const_iterator scope_iterator;
    899 
    900   iterator_range<compile_unit_iterator> compile_units() const {
    901     return iterator_range<compile_unit_iterator>(CUs.begin(), CUs.end());
    902   }
    903 
    904   iterator_range<subprogram_iterator> subprograms() const {
    905     return iterator_range<subprogram_iterator>(SPs.begin(), SPs.end());
    906   }
    907 
    908   iterator_range<global_variable_iterator> global_variables() const {
    909     return iterator_range<global_variable_iterator>(GVs.begin(), GVs.end());
    910   }
    911 
    912   iterator_range<type_iterator> types() const {
    913     return iterator_range<type_iterator>(TYs.begin(), TYs.end());
    914   }
    915 
    916   iterator_range<scope_iterator> scopes() const {
    917     return iterator_range<scope_iterator>(Scopes.begin(), Scopes.end());
    918   }
    919 
    920   unsigned compile_unit_count() const { return CUs.size(); }
    921   unsigned global_variable_count() const { return GVs.size(); }
    922   unsigned subprogram_count() const { return SPs.size(); }
    923   unsigned type_count() const { return TYs.size(); }
    924   unsigned scope_count() const { return Scopes.size(); }
    925 
    926 private:
    927   SmallVector<DICompileUnit, 8> CUs;    // Compile Units
    928   SmallVector<DISubprogram, 8> SPs;    // Subprograms
    929   SmallVector<DIGlobalVariable, 8> GVs;    // Global Variables;
    930   SmallVector<DIType, 8> TYs;    // Types
    931   SmallVector<DIScope, 8> Scopes; // Scopes
    932   SmallPtrSet<MDNode *, 64> NodesSeen;
    933   DITypeIdentifierMap TypeIdentifierMap;
    934   /// Specify if TypeIdentifierMap is initialized.
    935   bool TypeMapInitialized;
    936 };
    937 
    938 DenseMap<const Function *, DISubprogram> makeSubprogramMap(const Module &M);
    939 
    940 } // end namespace llvm
    941 
    942 #endif
    943