1 //===-- llvm/MC/MCObjectSymbolizer.h --------------------------------------===// 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 declares the MCObjectSymbolizer class, an MCSymbolizer that is 11 // backed by an object::ObjectFile. 12 // 13 //===----------------------------------------------------------------------===// 14 15 #ifndef LLVM_MC_MCOBJECTSYMBOLIZER_H 16 #define LLVM_MC_MCOBJECTSYMBOLIZER_H 17 18 #include "llvm/ADT/DenseMap.h" 19 #include "llvm/MC/MCSymbolizer.h" 20 #include "llvm/Object/ObjectFile.h" 21 #include <vector> 22 23 namespace llvm { 24 25 class MCExpr; 26 class MCInst; 27 class MCRelocationInfo; 28 class raw_ostream; 29 30 /// \brief An ObjectFile-backed symbolizer. 31 class MCObjectSymbolizer : public MCSymbolizer { 32 protected: 33 const object::ObjectFile *Obj; 34 35 // Map a load address to the first relocation that applies there. As far as I 36 // know, if there are several relocations at the exact same address, they are 37 // related and the others can be determined from the first that was found in 38 // the relocation table. For instance, on x86-64 mach-o, a SUBTRACTOR 39 // relocation (referencing the minuend symbol) is followed by an UNSIGNED 40 // relocation (referencing the subtrahend symbol). 41 const object::RelocationRef *findRelocationAt(uint64_t Addr); 42 const object::SectionRef *findSectionContaining(uint64_t Addr); 43 44 MCObjectSymbolizer(MCContext &Ctx, std::unique_ptr<MCRelocationInfo> RelInfo, 45 const object::ObjectFile *Obj); 46 47 public: 48 /// \name Overridden MCSymbolizer methods: 49 /// @{ 50 bool tryAddingSymbolicOperand(MCInst &MI, raw_ostream &cStream, 51 int64_t Value, uint64_t Address, 52 bool IsBranch, uint64_t Offset, 53 uint64_t InstSize) override; 54 55 void tryAddingPcLoadReferenceComment(raw_ostream &cStream, 56 int64_t Value, 57 uint64_t Address) override; 58 /// @} 59 60 /// \brief Look for an external function symbol at \p Addr. 61 /// (References through the ELF PLT, Mach-O stubs, and similar). 62 /// \returns An MCExpr representing the external symbol, or 0 if not found. 63 virtual StringRef findExternalFunctionAt(uint64_t Addr); 64 65 /// \brief Create an object symbolizer for \p Obj. 66 static MCObjectSymbolizer * 67 createObjectSymbolizer(MCContext &Ctx, 68 std::unique_ptr<MCRelocationInfo> RelInfo, 69 const object::ObjectFile *Obj); 70 71 private: 72 typedef DenseMap<uint64_t, object::RelocationRef> AddrToRelocMap; 73 typedef std::vector<object::SectionRef> SortedSectionList; 74 SortedSectionList SortedSections; 75 AddrToRelocMap AddrToReloc; 76 77 void buildSectionList(); 78 void buildRelocationByAddrMap(); 79 }; 80 81 } 82 83 #endif 84