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 "llvm/ExecutionEngine/JITSymbol.h" 18 #include "llvm/ExecutionEngine/RuntimeDyld.h" 19 #include "llvm/Support/CBindingWrapping.h" 20 #include "llvm-c/ExecutionEngine.h" 21 #include <cstddef> 22 #include <cstdint> 23 #include <string> 24 25 namespace llvm { 26 27 class ExecutionEngine; 28 29 namespace object { 30 class ObjectFile; 31 } // end namespace object 32 33 class MCJITMemoryManager : public RuntimeDyld::MemoryManager { 34 public: 35 // Don't hide the notifyObjectLoaded method from RuntimeDyld::MemoryManager. 36 using RuntimeDyld::MemoryManager::notifyObjectLoaded; 37 38 /// This method is called after an object has been loaded into memory but 39 /// before relocations are applied to the loaded sections. The object load 40 /// may have been initiated by MCJIT to resolve an external symbol for another 41 /// object that is being finalized. In that case, the object about which 42 /// the memory manager is being notified will be finalized immediately after 43 /// the memory manager returns from this call. 44 /// 45 /// Memory managers which are preparing code for execution in an external 46 /// address space can use this call to remap the section addresses for the 47 /// newly loaded object. 48 virtual void notifyObjectLoaded(ExecutionEngine *EE, 49 const object::ObjectFile &) {} 50 }; 51 52 // RuntimeDyld clients often want to handle the memory management of 53 // what gets placed where. For JIT clients, this is the subset of 54 // JITMemoryManager required for dynamic loading of binaries. 55 // 56 // FIXME: As the RuntimeDyld fills out, additional routines will be needed 57 // for the varying types of objects to be allocated. 58 class RTDyldMemoryManager : public MCJITMemoryManager, 59 public JITSymbolResolver { 60 public: 61 RTDyldMemoryManager() = default; 62 RTDyldMemoryManager(const RTDyldMemoryManager&) = delete; 63 void operator=(const RTDyldMemoryManager&) = delete; 64 ~RTDyldMemoryManager() override; 65 66 /// Register EH frames in the current process. 67 static void registerEHFramesInProcess(uint8_t *Addr, size_t Size); 68 69 /// Deregister EH frames in the current proces. 70 static void deregisterEHFramesInProcess(uint8_t *Addr, size_t Size); 71 72 void registerEHFrames(uint8_t *Addr, uint64_t LoadAddr, size_t Size) override { 73 registerEHFramesInProcess(Addr, Size); 74 } 75 76 void deregisterEHFrames(uint8_t *Addr, uint64_t LoadAddr, size_t Size) override { 77 deregisterEHFramesInProcess(Addr, Size); 78 } 79 80 /// This method returns the address of the specified function or variable in 81 /// the current process. 82 static uint64_t getSymbolAddressInProcess(const std::string &Name); 83 84 /// Legacy symbol lookup - DEPRECATED! Please override findSymbol instead. 85 /// 86 /// This method returns the address of the specified function or variable. 87 /// It is used to resolve symbols during module linking. 88 virtual uint64_t getSymbolAddress(const std::string &Name) { 89 return getSymbolAddressInProcess(Name); 90 } 91 92 /// This method returns a RuntimeDyld::SymbolInfo for the specified function 93 /// or variable. It is used to resolve symbols during module linking. 94 /// 95 /// By default this falls back on the legacy lookup method: 96 /// 'getSymbolAddress'. The address returned by getSymbolAddress is treated as 97 /// a strong, exported symbol, consistent with historical treatment by 98 /// RuntimeDyld. 99 /// 100 /// Clients writing custom RTDyldMemoryManagers are encouraged to override 101 /// this method and return a SymbolInfo with the flags set correctly. This is 102 /// necessary for RuntimeDyld to correctly handle weak and non-exported symbols. 103 JITSymbol findSymbol(const std::string &Name) override { 104 return JITSymbol(getSymbolAddress(Name), JITSymbolFlags::Exported); 105 } 106 107 /// Legacy symbol lookup -- DEPRECATED! Please override 108 /// findSymbolInLogicalDylib instead. 109 /// 110 /// Default to treating all modules as separate. 111 virtual uint64_t getSymbolAddressInLogicalDylib(const std::string &Name) { 112 return 0; 113 } 114 115 /// Default to treating all modules as separate. 116 /// 117 /// By default this falls back on the legacy lookup method: 118 /// 'getSymbolAddressInLogicalDylib'. The address returned by 119 /// getSymbolAddressInLogicalDylib is treated as a strong, exported symbol, 120 /// consistent with historical treatment by RuntimeDyld. 121 /// 122 /// Clients writing custom RTDyldMemoryManagers are encouraged to override 123 /// this method and return a SymbolInfo with the flags set correctly. This is 124 /// necessary for RuntimeDyld to correctly handle weak and non-exported symbols. 125 JITSymbol 126 findSymbolInLogicalDylib(const std::string &Name) override { 127 return JITSymbol(getSymbolAddressInLogicalDylib(Name), 128 JITSymbolFlags::Exported); 129 } 130 131 /// This method returns the address of the specified function. As such it is 132 /// only useful for resolving library symbols, not code generated symbols. 133 /// 134 /// If \p AbortOnFailure is false and no function with the given name is 135 /// found, this function returns a null pointer. Otherwise, it prints a 136 /// message to stderr and aborts. 137 /// 138 /// This function is deprecated for memory managers to be used with 139 /// MCJIT or RuntimeDyld. Use getSymbolAddress instead. 140 virtual void *getPointerToNamedFunction(const std::string &Name, 141 bool AbortOnFailure = true); 142 }; 143 144 // Create wrappers for C Binding types (see CBindingWrapping.h). 145 DEFINE_SIMPLE_CONVERSION_FUNCTIONS( 146 RTDyldMemoryManager, LLVMMCJITMemoryManagerRef) 147 148 } // end namespace llvm 149 150 #endif // LLVM_EXECUTIONENGINE_RTDYLDMEMORYMANAGER_H 151
