1 //===- IdenticalCodeFolding.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 MCLD_LD_IDENTICALCODEFOLDING_H 10 #define MCLD_LD_IDENTICALCODEFOLDING_H 11 12 #include <llvm/ADT/MapVector.h> 13 #include <string> 14 #include <vector> 15 16 namespace mcld { 17 class Input; 18 class LDSection; 19 class LinkerConfig; 20 class Module; 21 class Relocation; 22 class TargetLDBackend; 23 24 /** \class IdenticalCodeFolding 25 * \brief Implementation of identical code folding for --icf=[none|all|safe] 26 * @ref Safe ICF: Pointer Safe and Unwinding Aware Identical Code Folding in 27 * Gold, http://research.google.com/pubs/pub36912.html 28 */ 29 class IdenticalCodeFolding { 30 public: 31 typedef std::pair<Input*, size_t> ObjectAndId; 32 typedef llvm::MapVector<LDSection*, ObjectAndId> KeptSections; 33 34 private: 35 class FoldingCandidate { 36 public: 37 FoldingCandidate() 38 : sect(NULL), reloc_sect(NULL), obj(NULL) 39 { } 40 FoldingCandidate(LDSection* pCode, LDSection* pReloc, Input* pInput) 41 : sect(pCode), reloc_sect(pReloc), obj(pInput) 42 { } 43 44 void initConstantContent(const TargetLDBackend& pBackend, 45 const IdenticalCodeFolding::KeptSections& pKeptSections); 46 std::string getContentWithVariables(const TargetLDBackend& pBackend, 47 const IdenticalCodeFolding::KeptSections& pKeptSections); 48 49 LDSection* sect; 50 LDSection* reloc_sect; 51 Input* obj; 52 std::string content; 53 std::vector<Relocation*> variable_relocs; 54 }; 55 56 typedef std::vector<FoldingCandidate> FoldingCandidates; 57 58 public: 59 IdenticalCodeFolding(const LinkerConfig& pConfig, 60 const TargetLDBackend& pBackend, 61 Module& pModule); 62 63 void foldIdenticalCode(); 64 65 private: 66 void findCandidates(FoldingCandidates& pCandidateList); 67 68 bool matchCandidates(FoldingCandidates& pCandidateList); 69 70 private: 71 const LinkerConfig& m_Config; 72 const TargetLDBackend& m_Backend; 73 Module& m_Module; 74 KeptSections m_KeptSections; 75 }; 76 77 } // namespace of mcld 78 79 #endif 80
