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      1 //===-  HexagonRelocator.h ------------------------------------------------===//
      2 //
      3 //                     The MCLinker Project
      4 //
      5 // This file is distributed under the University of Illinois Open Source
      6 // License. See LICENSE.TXT for details.
      7 //
      8 //===----------------------------------------------------------------------===//
      9 #ifndef TARGET_HEXAGON_HEXAGONRELOCATOR_H
     10 #define TARGET_HEXAGON_HEXAGONRELOCATOR_H
     11 
     12 #include <mcld/LD/Relocator.h>
     13 #include <mcld/Target/GOT.h>
     14 #include <mcld/Target/PLT.h>
     15 #include <mcld/Target/KeyEntryMap.h>
     16 #include "HexagonLDBackend.h"
     17 
     18 namespace mcld {
     19 
     20 class ResolveInfo;
     21 class LinkerConfig;
     22 
     23 /** \class HexagonRelocator
     24  *  \brief HexagonRelocator creates and destroys the Hexagon relocations.
     25  *
     26  */
     27 class HexagonRelocator : public Relocator
     28 {
     29 public:
     30   typedef KeyEntryMap<ResolveInfo, PLTEntryBase> SymPLTMap;
     31   typedef KeyEntryMap<ResolveInfo, HexagonGOTEntry> SymGOTMap;
     32   typedef KeyEntryMap<ResolveInfo, HexagonGOTEntry> SymGOTPLTMap;
     33   typedef KeyEntryMap<Relocation, Relocation> RelRelMap;
     34 
     35 public:
     36   /** \enum ReservedEntryType
     37    *  \brief The reserved entry type of reserved space in ResolveInfo.
     38    *
     39    *  This is used for sacnRelocation to record what kinds of entries are
     40    *  reserved for this resolved symbol. In Hexagon, there are three kinds
     41    *  of entries, GOT, PLT, and dynamic relocation.
     42    *
     43    *  bit:  3     2     1     0
     44    *   |    | PLT | GOT | Rel |
     45    *
     46    *  value    Name         - Description
     47    *
     48    *  0000     None         - no reserved entry
     49    *  0001     ReserveRel   - reserve an dynamic relocation entry
     50    *  0010     ReserveGOT   - reserve an GOT entry
     51    *  0100     ReservePLT   - reserve an PLT entry and the corresponding GOT,
     52    *
     53    */
     54   enum ReservedEntryType {
     55     None         = 0,
     56     ReserveRel   = 1,
     57     ReserveGOT   = 2,
     58     ReservePLT   = 4,
     59   };
     60 
     61   /** \enum EntryValue
     62    *  \brief The value of the entries. The symbol value will be decided at after
     63    *  layout, so we mark the entry during scanRelocation and fill up the actual
     64    *  value when applying relocations.
     65    */
     66   enum EntryValue {
     67     Default = 0,
     68     SymVal  = 1
     69   };
     70 
     71   HexagonRelocator(HexagonLDBackend& pParent, const LinkerConfig& pConfig);
     72   ~HexagonRelocator();
     73 
     74   Result applyRelocation(Relocation& pRelocation);
     75 
     76   /// scanRelocation - determine the empty entries are needed or not and create
     77   /// the empty entries if needed.
     78   /// For Hexagon, following entries are check to create:
     79   /// - GOT entry (for .got and .got.plt sections)
     80   /// - PLT entry (for .plt section)
     81   /// - dynamin relocation entries (for .rel.plt and .rel.dyn sections)
     82   void scanRelocation(Relocation& pReloc,
     83                       IRBuilder& pBuilder,
     84                       Module& pModule,
     85                       LDSection& pSection,
     86                       Input& pInput);
     87 
     88   // Handle partial linking
     89   void partialScanRelocation(Relocation& pReloc,
     90                              Module& pModule,
     91                              const LDSection& pSection);
     92 
     93   HexagonLDBackend& getTarget()
     94   { return m_Target; }
     95 
     96   const HexagonLDBackend& getTarget() const
     97   { return m_Target; }
     98 
     99   const char* getName(Relocation::Type pType) const;
    100 
    101   Size getSize(Relocation::Type pType) const;
    102 
    103   const SymPLTMap& getSymPLTMap() const { return m_SymPLTMap; }
    104   SymPLTMap&       getSymPLTMap()       { return m_SymPLTMap; }
    105 
    106   const SymGOTMap& getSymGOTMap() const { return m_SymGOTMap; }
    107   SymGOTMap&       getSymGOTMap()       { return m_SymGOTMap; }
    108 
    109   const SymGOTPLTMap& getSymGOTPLTMap() const { return m_SymGOTPLTMap; }
    110   SymGOTPLTMap&       getSymGOTPLTMap()       { return m_SymGOTPLTMap; }
    111 
    112   const RelRelMap& getRelRelMap() const { return m_RelRelMap; }
    113   RelRelMap&       getRelRelMap()       { return m_RelRelMap; }
    114 
    115 protected:
    116   /// addCopyReloc - add a copy relocation into .rela.dyn for pSym
    117   /// @param pSym - A resolved copy symbol that defined in BSS section
    118   void addCopyReloc(ResolveInfo& pSym, HexagonLDBackend& pTarget);
    119 
    120   /// defineSymbolforCopyReloc - allocate a space in BSS section and
    121   /// and force define the copy of pSym to BSS section
    122   /// @return the output LDSymbol of the copy symbol
    123   LDSymbol& defineSymbolforCopyReloc(IRBuilder& pLinker,
    124                                      const ResolveInfo& pSym,
    125                                      HexagonLDBackend& pTarget);
    126 
    127 private:
    128   virtual void scanLocalReloc(Relocation& pReloc,
    129                               IRBuilder& pBuilder,
    130                               Module& pModule,
    131                               LDSection& pSection);
    132 
    133   virtual void scanGlobalReloc(Relocation& pReloc,
    134                                IRBuilder& pBuilder,
    135                                Module& pModule,
    136                                LDSection& pSection);
    137 
    138   HexagonLDBackend& m_Target;
    139   SymPLTMap m_SymPLTMap;
    140   SymGOTMap m_SymGOTMap;
    141   SymGOTPLTMap m_SymGOTPLTMap;
    142   RelRelMap m_RelRelMap;
    143 };
    144 
    145 } // namespace of mcld
    146 
    147 #endif
    148 
    149