1 //===-- RTDyldMemoryManager.cpp - Memory manager for MC-JIT -----*- C++ -*-===// 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 // Interface of the runtime dynamic memory manager base class. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #ifndef LLVM_EXECUTIONENGINE_RTDYLDMEMORYMANAGER_H 15 #define LLVM_EXECUTIONENGINE_RTDYLDMEMORYMANAGER_H 16 17 #include "RuntimeDyld.h" 18 #include "llvm-c/ExecutionEngine.h" 19 #include "llvm/ADT/StringRef.h" 20 #include "llvm/Support/CBindingWrapping.h" 21 #include "llvm/Support/Memory.h" 22 23 namespace llvm { 24 25 class ExecutionEngine; 26 27 namespace object { 28 class ObjectFile; 29 } 30 31 class MCJITMemoryManager : public RuntimeDyld::MemoryManager { 32 public: 33 /// This method is called after an object has been loaded into memory but 34 /// before relocations are applied to the loaded sections. The object load 35 /// may have been initiated by MCJIT to resolve an external symbol for another 36 /// object that is being finalized. In that case, the object about which 37 /// the memory manager is being notified will be finalized immediately after 38 /// the memory manager returns from this call. 39 /// 40 /// Memory managers which are preparing code for execution in an external 41 /// address space can use this call to remap the section addresses for the 42 /// newly loaded object. notifyObjectLoaded(ExecutionEngine * EE,const object::ObjectFile &)43 virtual void notifyObjectLoaded(ExecutionEngine *EE, 44 const object::ObjectFile &) {} 45 }; 46 47 // RuntimeDyld clients often want to handle the memory management of 48 // what gets placed where. For JIT clients, this is the subset of 49 // JITMemoryManager required for dynamic loading of binaries. 50 // 51 // FIXME: As the RuntimeDyld fills out, additional routines will be needed 52 // for the varying types of objects to be allocated. 53 class RTDyldMemoryManager : public MCJITMemoryManager, 54 public RuntimeDyld::SymbolResolver { 55 RTDyldMemoryManager(const RTDyldMemoryManager&) = delete; 56 void operator=(const RTDyldMemoryManager&) = delete; 57 public: RTDyldMemoryManager()58 RTDyldMemoryManager() {} 59 ~RTDyldMemoryManager() override; 60 61 void registerEHFrames(uint8_t *Addr, uint64_t LoadAddr, size_t Size) override; 62 void deregisterEHFrames(uint8_t *Addr, uint64_t LoadAddr, size_t Size) override; 63 64 /// This method returns the address of the specified function or variable in 65 /// the current process. 66 static uint64_t getSymbolAddressInProcess(const std::string &Name); 67 68 /// Legacy symbol lookup - DEPRECATED! Please override findSymbol instead. 69 /// 70 /// This method returns the address of the specified function or variable. 71 /// It is used to resolve symbols during module linking. getSymbolAddress(const std::string & Name)72 virtual uint64_t getSymbolAddress(const std::string &Name) { 73 return getSymbolAddressInProcess(Name); 74 } 75 76 /// This method returns a RuntimeDyld::SymbolInfo for the specified function 77 /// or variable. It is used to resolve symbols during module linking. 78 /// 79 /// By default this falls back on the legacy lookup method: 80 /// 'getSymbolAddress'. The address returned by getSymbolAddress is treated as 81 /// a strong, exported symbol, consistent with historical treatment by 82 /// RuntimeDyld. 83 /// 84 /// Clients writing custom RTDyldMemoryManagers are encouraged to override 85 /// this method and return a SymbolInfo with the flags set correctly. This is 86 /// necessary for RuntimeDyld to correctly handle weak and non-exported symbols. findSymbol(const std::string & Name)87 RuntimeDyld::SymbolInfo findSymbol(const std::string &Name) override { 88 return RuntimeDyld::SymbolInfo(getSymbolAddress(Name), 89 JITSymbolFlags::Exported); 90 } 91 92 /// Legacy symbol lookup -- DEPRECATED! Please override 93 /// findSymbolInLogicalDylib instead. 94 /// 95 /// Default to treating all modules as separate. getSymbolAddressInLogicalDylib(const std::string & Name)96 virtual uint64_t getSymbolAddressInLogicalDylib(const std::string &Name) { 97 return 0; 98 } 99 100 /// Default to treating all modules as separate. 101 /// 102 /// By default this falls back on the legacy lookup method: 103 /// 'getSymbolAddressInLogicalDylib'. The address returned by 104 /// getSymbolAddressInLogicalDylib is treated as a strong, exported symbol, 105 /// consistent with historical treatment by RuntimeDyld. 106 /// 107 /// Clients writing custom RTDyldMemoryManagers are encouraged to override 108 /// this method and return a SymbolInfo with the flags set correctly. This is 109 /// necessary for RuntimeDyld to correctly handle weak and non-exported symbols. 110 RuntimeDyld::SymbolInfo findSymbolInLogicalDylib(const std::string & Name)111 findSymbolInLogicalDylib(const std::string &Name) override { 112 return RuntimeDyld::SymbolInfo(getSymbolAddressInLogicalDylib(Name), 113 JITSymbolFlags::Exported); 114 } 115 116 /// This method returns the address of the specified function. As such it is 117 /// only useful for resolving library symbols, not code generated symbols. 118 /// 119 /// If \p AbortOnFailure is false and no function with the given name is 120 /// found, this function returns a null pointer. Otherwise, it prints a 121 /// message to stderr and aborts. 122 /// 123 /// This function is deprecated for memory managers to be used with 124 /// MCJIT or RuntimeDyld. Use getSymbolAddress instead. 125 virtual void *getPointerToNamedFunction(const std::string &Name, 126 bool AbortOnFailure = true); 127 }; 128 129 // Create wrappers for C Binding types (see CBindingWrapping.h). 130 DEFINE_SIMPLE_CONVERSION_FUNCTIONS( 131 RTDyldMemoryManager, LLVMMCJITMemoryManagerRef) 132 133 } // namespace llvm 134 135 136 #endif 137