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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  public:
     28   AArch64GOTEntry(uint64_t pContent, SectionData* pParent)
     29       : GOT::Entry<8>(pContent, pParent) {}
     30 };
     31 
     32 /** \class AArch64GOT
     33  *  \brief AArch64 Global Offset Table.
     34  *
     35  *  AArch64 GOT integrates traditional .got.plt and .got sections into one.
     36  *  Traditional .got.plt is placed in the front part of GOT (PLTGOT), and
     37  *  traditional .got is placed in the rear part of GOT (GOT). When -z now and
     38  *  -z relro are given, the got section layout will be as below. Otherwise,
     39  *  there will be two seperated sections, .got and .got.plt.
     40  *
     41  *  This class may be used as .got (with no GOTPLT entry), .got.plt (with only
     42  *  GOTPLT entries) or .got (with GOTPLT and normal GOT entries)
     43  *
     44  *  AArch64 .got
     45  *            +--------------+
     46  *            |    GOT0      |
     47  *            +--------------+
     48  *            |    GOTPLT    |
     49  *            +--------------+
     50  *            |    GOT       |
     51  *            +--------------+
     52  *
     53  */
     54 class AArch64GOT : public GOT {
     55  public:
     56   explicit AArch64GOT(LDSection& pSection);
     57 
     58   ~AArch64GOT();
     59 
     60   /// createGOT0 - create the defualt GOT0 entries. This function called when
     61   /// it's a .got section (with GOTPLT entries and normal GOT entry) or it's a
     62   /// .got.plt section
     63   void createGOT0();
     64 
     65   AArch64GOTEntry* createGOT();
     66   AArch64GOTEntry* createGOTPLT();
     67 
     68   void finalizeSectionSize();
     69 
     70   uint64_t emit(MemoryRegion& pRegion);
     71 
     72   void applyGOT0(uint64_t pAddress);
     73 
     74   void applyGOTPLT(uint64_t pPLTBase);
     75 
     76   bool hasGOT1() const;
     77 
     78  private:
     79   typedef std::vector<AArch64GOTEntry*> EntryListType;
     80   typedef EntryListType::iterator entry_iterator;
     81   typedef EntryListType::const_iterator const_entry_iterator;
     82 
     83  private:
     84   AArch64GOTEntry* m_pGOTPLTFront;
     85   AArch64GOTEntry* m_pGOTFront;
     86 
     87   /// m_GOTPLTEntries - a list of gotplt entries
     88   EntryListType m_GOTPLT;
     89 
     90   /// m_GOTEntris - a list of got entries
     91   EntryListType m_GOT;
     92 };
     93 
     94 }  // namespace mcld
     95 
     96 #endif  // TARGET_AARCH64_AARCH64GOT_H_
     97