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      1 //===- AArch64GOT.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_AARCH64_AARCH64GOT_H
     10 #define TARGET_AARCH64_AARCH64GOT_H
     11 
     12 #include <mcld/Support/MemoryRegion.h>
     13 #include <mcld/Target/GOT.h>
     14 
     15 #include <llvm/ADT/DenseMap.h>
     16 
     17 #include <vector>
     18 
     19 namespace mcld {
     20 
     21 class LDSection;
     22 
     23 /** \class AArch64GOTEntry
     24  *  \brief GOT Entry with size of 8 bytes
     25  */
     26 class AArch64GOTEntry : public GOT::Entry<8>
     27 {
     28 public:
     29   AArch64GOTEntry(uint64_t pContent, SectionData* pParent)
     30    : GOT::Entry<8>(pContent, pParent)
     31   {}
     32 };
     33 
     34 /** \class AArch64GOT
     35  *  \brief AArch64 Global Offset Table.
     36  *
     37  *  AArch64 GOT integrates traditional .got.plt and .got sections into one.
     38  *  Traditional .got.plt is placed in the front part of GOT (PLTGOT), and
     39  *  traditional .got is placed in the rear part of GOT (GOT). When -z now and
     40  *  -z relro are given, the got section layout will be as below. Otherwise,
     41  *  there will be two seperated sections, .got and .got.plt.
     42  *
     43  *  This class may be used as .got (with no GOTPLT entry), .got.plt (with only
     44  *  GOTPLT entries) or .got (with GOTPLT and normal GOT entries)
     45  *
     46  *  AArch64 .got
     47  *            +--------------+
     48  *            |    GOT0      |
     49  *            +--------------+
     50  *            |    GOTPLT    |
     51  *            +--------------+
     52  *            |    GOT       |
     53  *            +--------------+
     54  *
     55  */
     56 class AArch64GOT : public GOT
     57 {
     58 public:
     59   AArch64GOT(LDSection &pSection);
     60 
     61   ~AArch64GOT();
     62 
     63   /// createGOT0 - create the defualt GOT0 entries. This function called when
     64   /// it's a .got section (with GOTPLT entries and normal GOT entry) or it's a
     65   /// .got.plt section
     66   void createGOT0();
     67 
     68   AArch64GOTEntry* createGOT();
     69   AArch64GOTEntry* createGOTPLT();
     70 
     71   void finalizeSectionSize();
     72 
     73   uint64_t emit(MemoryRegion& pRegion);
     74 
     75   void applyGOT0(uint64_t pAddress);
     76 
     77   void applyGOTPLT(uint64_t pPLTBase);
     78 
     79   bool hasGOT1() const;
     80 
     81 private:
     82   typedef std::vector<AArch64GOTEntry*> EntryListType;
     83   typedef EntryListType::iterator entry_iterator;
     84   typedef EntryListType::const_iterator const_entry_iterator;
     85 
     86 private:
     87   AArch64GOTEntry* m_pGOTPLTFront;
     88   AArch64GOTEntry* m_pGOTFront;
     89 
     90   /// m_GOTPLTEntries - a list of gotplt entries
     91   EntryListType m_GOTPLT;
     92 
     93   /// m_GOTEntris - a list of got entries
     94   EntryListType m_GOT;
     95 };
     96 
     97 } // namespace of mcld
     98 
     99 #endif
    100 
    101