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      1 //===-- llvm/CodeGen/DwarfCompileUnit.h - Dwarf Compile Unit ---*- 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 contains support for writing dwarf compile unit.
     11 //
     12 //===----------------------------------------------------------------------===//
     13 
     14 #ifndef LLVM_LIB_CODEGEN_ASMPRINTER_DWARFCOMPILEUNIT_H
     15 #define LLVM_LIB_CODEGEN_ASMPRINTER_DWARFCOMPILEUNIT_H
     16 
     17 #include "DwarfUnit.h"
     18 #include "llvm/IR/DebugInfo.h"
     19 #include "llvm/Support/Dwarf.h"
     20 
     21 namespace llvm {
     22 
     23 class StringRef;
     24 class AsmPrinter;
     25 class DIE;
     26 class DwarfDebug;
     27 class DwarfFile;
     28 class MCSymbol;
     29 class LexicalScope;
     30 
     31 class DwarfCompileUnit : public DwarfUnit {
     32   /// A numeric ID unique among all CUs in the module
     33   unsigned UniqueID;
     34 
     35   /// Offset of the UnitDie from beginning of debug info section.
     36   unsigned DebugInfoOffset = 0;
     37 
     38   /// The attribute index of DW_AT_stmt_list in the compile unit DIE, avoiding
     39   /// the need to search for it in applyStmtList.
     40   DIE::value_iterator StmtListValue;
     41 
     42   /// Skeleton unit associated with this unit.
     43   DwarfCompileUnit *Skeleton;
     44 
     45   /// The start of the unit within its section.
     46   MCSymbol *LabelBegin;
     47 
     48   /// The start of the unit macro info within macro section.
     49   MCSymbol *MacroLabelBegin;
     50 
     51   typedef llvm::SmallVector<const MDNode *, 8> ImportedEntityList;
     52   typedef llvm::DenseMap<const MDNode *, ImportedEntityList>
     53   ImportedEntityMap;
     54 
     55   ImportedEntityMap ImportedEntities;
     56 
     57   /// GlobalNames - A map of globally visible named entities for this unit.
     58   StringMap<const DIE *> GlobalNames;
     59 
     60   /// GlobalTypes - A map of globally visible types for this unit.
     61   StringMap<const DIE *> GlobalTypes;
     62 
     63   // List of range lists for a given compile unit, separate from the ranges for
     64   // the CU itself.
     65   SmallVector<RangeSpanList, 1> CURangeLists;
     66 
     67   // List of ranges for a given compile unit.
     68   SmallVector<RangeSpan, 2> CURanges;
     69 
     70   // The base address of this unit, if any. Used for relative references in
     71   // ranges/locs.
     72   const MCSymbol *BaseAddress;
     73 
     74   /// \brief Construct a DIE for the given DbgVariable without initializing the
     75   /// DbgVariable's DIE reference.
     76   DIE *constructVariableDIEImpl(const DbgVariable &DV, bool Abstract);
     77 
     78   bool isDwoUnit() const override;
     79 
     80   bool includeMinimalInlineScopes() const;
     81 
     82 public:
     83   DwarfCompileUnit(unsigned UID, const DICompileUnit *Node, AsmPrinter *A,
     84                    DwarfDebug *DW, DwarfFile *DWU);
     85 
     86   unsigned getUniqueID() const { return UniqueID; }
     87   unsigned getDebugInfoOffset() const { return DebugInfoOffset; }
     88   void setDebugInfoOffset(unsigned DbgInfoOff) { DebugInfoOffset = DbgInfoOff; }
     89 
     90   DwarfCompileUnit *getSkeleton() const {
     91     return Skeleton;
     92   }
     93 
     94   void initStmtList();
     95 
     96   /// Apply the DW_AT_stmt_list from this compile unit to the specified DIE.
     97   void applyStmtList(DIE &D);
     98 
     99   /// getOrCreateGlobalVariableDIE - get or create global variable DIE.
    100   DIE *getOrCreateGlobalVariableDIE(const DIGlobalVariable *GV);
    101 
    102   /// addLabelAddress - Add a dwarf label attribute data and value using
    103   /// either DW_FORM_addr or DW_FORM_GNU_addr_index.
    104   void addLabelAddress(DIE &Die, dwarf::Attribute Attribute,
    105                        const MCSymbol *Label);
    106 
    107   /// addLocalLabelAddress - Add a dwarf label attribute data and value using
    108   /// DW_FORM_addr only.
    109   void addLocalLabelAddress(DIE &Die, dwarf::Attribute Attribute,
    110                             const MCSymbol *Label);
    111 
    112   /// addSectionDelta - Add a label delta attribute data and value.
    113   DIE::value_iterator addSectionDelta(DIE &Die, dwarf::Attribute Attribute,
    114                                       const MCSymbol *Hi, const MCSymbol *Lo);
    115 
    116   DwarfCompileUnit &getCU() override { return *this; }
    117 
    118   unsigned getOrCreateSourceID(StringRef FileName, StringRef DirName) override;
    119 
    120   void addImportedEntity(const DIImportedEntity* IE) {
    121     DIScope *Scope = IE->getScope();
    122     assert(Scope && "Invalid Scope encoding!");
    123     if (!isa<DILocalScope>(Scope))
    124       // No need to add imported enities that are not local declaration.
    125       return;
    126 
    127     auto *LocalScope = cast<DILocalScope>(Scope)->getNonLexicalBlockFileScope();
    128     ImportedEntities[LocalScope].push_back(IE);
    129   }
    130 
    131   /// addRange - Add an address range to the list of ranges for this unit.
    132   void addRange(RangeSpan Range);
    133 
    134   void attachLowHighPC(DIE &D, const MCSymbol *Begin, const MCSymbol *End);
    135 
    136   /// addSectionLabel - Add a Dwarf section label attribute data and value.
    137   ///
    138   DIE::value_iterator addSectionLabel(DIE &Die, dwarf::Attribute Attribute,
    139                                       const MCSymbol *Label,
    140                                       const MCSymbol *Sec);
    141 
    142   /// \brief Find DIE for the given subprogram and attach appropriate
    143   /// DW_AT_low_pc and DW_AT_high_pc attributes. If there are global
    144   /// variables in this scope then create and insert DIEs for these
    145   /// variables.
    146   DIE &updateSubprogramScopeDIE(const DISubprogram *SP);
    147 
    148   void constructScopeDIE(LexicalScope *Scope,
    149                          SmallVectorImpl<DIE *> &FinalChildren);
    150 
    151   /// \brief A helper function to construct a RangeSpanList for a given
    152   /// lexical scope.
    153   void addScopeRangeList(DIE &ScopeDIE, SmallVector<RangeSpan, 2> Range);
    154 
    155   void attachRangesOrLowHighPC(DIE &D, SmallVector<RangeSpan, 2> Ranges);
    156 
    157   void attachRangesOrLowHighPC(DIE &D,
    158                                const SmallVectorImpl<InsnRange> &Ranges);
    159   /// \brief This scope represents inlined body of a function. Construct
    160   /// DIE to represent this concrete inlined copy of the function.
    161   DIE *constructInlinedScopeDIE(LexicalScope *Scope);
    162 
    163   /// \brief Construct new DW_TAG_lexical_block for this scope and
    164   /// attach DW_AT_low_pc/DW_AT_high_pc labels.
    165   DIE *constructLexicalScopeDIE(LexicalScope *Scope);
    166 
    167   /// constructVariableDIE - Construct a DIE for the given DbgVariable.
    168   DIE *constructVariableDIE(DbgVariable &DV, bool Abstract = false);
    169 
    170   DIE *constructVariableDIE(DbgVariable &DV, const LexicalScope &Scope,
    171                             DIE *&ObjectPointer);
    172 
    173   /// A helper function to create children of a Scope DIE.
    174   DIE *createScopeChildrenDIE(LexicalScope *Scope,
    175                               SmallVectorImpl<DIE *> &Children,
    176                               unsigned *ChildScopeCount = nullptr);
    177 
    178   /// \brief Construct a DIE for this subprogram scope.
    179   void constructSubprogramScopeDIE(LexicalScope *Scope);
    180 
    181   DIE *createAndAddScopeChildren(LexicalScope *Scope, DIE &ScopeDIE);
    182 
    183   void constructAbstractSubprogramScopeDIE(LexicalScope *Scope);
    184 
    185   /// \brief Construct import_module DIE.
    186   DIE *constructImportedEntityDIE(const DIImportedEntity *Module);
    187 
    188   void finishSubprogramDefinition(const DISubprogram *SP);
    189 
    190   /// Set the skeleton unit associated with this unit.
    191   void setSkeleton(DwarfCompileUnit &Skel) { Skeleton = &Skel; }
    192 
    193   const MCSymbol *getSectionSym() const {
    194     assert(Section);
    195     return Section->getBeginSymbol();
    196   }
    197 
    198   unsigned getLength() {
    199     return sizeof(uint32_t) + // Length field
    200         getHeaderSize() + UnitDie.getSize();
    201   }
    202 
    203   void emitHeader(bool UseOffsets) override;
    204 
    205   MCSymbol *getLabelBegin() const {
    206     assert(Section);
    207     return LabelBegin;
    208   }
    209 
    210   MCSymbol *getMacroLabelBegin() const {
    211     return MacroLabelBegin;
    212   }
    213 
    214   /// Add a new global name to the compile unit.
    215   void addGlobalName(StringRef Name, DIE &Die, const DIScope *Context) override;
    216 
    217   /// Add a new global type to the compile unit.
    218   void addGlobalType(const DIType *Ty, const DIE &Die,
    219                      const DIScope *Context) override;
    220 
    221   const StringMap<const DIE *> &getGlobalNames() const { return GlobalNames; }
    222   const StringMap<const DIE *> &getGlobalTypes() const { return GlobalTypes; }
    223 
    224   /// Add DW_AT_location attribute for a DbgVariable based on provided
    225   /// MachineLocation.
    226   void addVariableAddress(const DbgVariable &DV, DIE &Die,
    227                           MachineLocation Location);
    228   /// Add an address attribute to a die based on the location provided.
    229   void addAddress(DIE &Die, dwarf::Attribute Attribute,
    230                   const MachineLocation &Location);
    231 
    232   /// Start with the address based on the location provided, and generate the
    233   /// DWARF information necessary to find the actual variable (navigating the
    234   /// extra location information encoded in the type) based on the starting
    235   /// location.  Add the DWARF information to the die.
    236   void addComplexAddress(const DbgVariable &DV, DIE &Die,
    237                          dwarf::Attribute Attribute,
    238                          const MachineLocation &Location);
    239 
    240   /// Add a Dwarf loclistptr attribute data and value.
    241   void addLocationList(DIE &Die, dwarf::Attribute Attribute, unsigned Index);
    242   void applyVariableAttributes(const DbgVariable &Var, DIE &VariableDie);
    243 
    244   /// Add a Dwarf expression attribute data and value.
    245   void addExpr(DIELoc &Die, dwarf::Form Form, const MCExpr *Expr);
    246 
    247   void applySubprogramAttributesToDefinition(const DISubprogram *SP,
    248                                              DIE &SPDie);
    249 
    250   /// getRangeLists - Get the vector of range lists.
    251   const SmallVectorImpl<RangeSpanList> &getRangeLists() const {
    252     return (Skeleton ? Skeleton : this)->CURangeLists;
    253   }
    254 
    255   /// getRanges - Get the list of ranges for this unit.
    256   const SmallVectorImpl<RangeSpan> &getRanges() const { return CURanges; }
    257   SmallVector<RangeSpan, 2> takeRanges() { return std::move(CURanges); }
    258 
    259   void setBaseAddress(const MCSymbol *Base) { BaseAddress = Base; }
    260   const MCSymbol *getBaseAddress() const { return BaseAddress; }
    261 };
    262 
    263 } // end llvm namespace
    264 
    265 #endif
    266