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-c/ExecutionEngine.h"
18#include "llvm/ExecutionEngine/JITSymbol.h"
19#include "llvm/ExecutionEngine/RuntimeDyld.h"
20#include "llvm/Support/CBindingWrapping.h"
21#include <cstddef>
22#include <cstdint>
23#include <string>
24
25namespace llvm {
26
27class ExecutionEngine;
28
29namespace object {
30 class ObjectFile;
31} // end namespace object
32
33class MCJITMemoryManager : public RuntimeDyld::MemoryManager {
34public:
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
51private:
52 void anchor() override;
53};
54
55// RuntimeDyld clients often want to handle the memory management of
56// what gets placed where. For JIT clients, this is the subset of
57// JITMemoryManager required for dynamic loading of binaries.
58//
59// FIXME: As the RuntimeDyld fills out, additional routines will be needed
60// for the varying types of objects to be allocated.
61class RTDyldMemoryManager : public MCJITMemoryManager,
62 public LegacyJITSymbolResolver {
63public:
64 RTDyldMemoryManager() = default;
65 RTDyldMemoryManager(const RTDyldMemoryManager&) = delete;
66 void operator=(const RTDyldMemoryManager&) = delete;
67 ~RTDyldMemoryManager() override;
68
69 /// Register EH frames in the current process.
70 static void registerEHFramesInProcess(uint8_t *Addr, size_t Size);
71
72 /// Deregister EH frames in the current proces.
73 static void deregisterEHFramesInProcess(uint8_t *Addr, size_t Size);
74
75 void registerEHFrames(uint8_t *Addr, uint64_t LoadAddr, size_t Size) override;
76 void deregisterEHFrames() override;
77
78 /// This method returns the address of the specified function or variable in
79 /// the current process.
80 static uint64_t getSymbolAddressInProcess(const std::string &Name);
81
82 /// Legacy symbol lookup - DEPRECATED! Please override findSymbol instead.
83 ///
84 /// This method returns the address of the specified function or variable.
85 /// It is used to resolve symbols during module linking.
86 virtual uint64_t getSymbolAddress(const std::string &Name) {
87 return getSymbolAddressInProcess(Name);
88 }
89
90 /// This method returns a RuntimeDyld::SymbolInfo for the specified function
91 /// or variable. It is used to resolve symbols during module linking.
92 ///
93 /// By default this falls back on the legacy lookup method:
94 /// 'getSymbolAddress'. The address returned by getSymbolAddress is treated as
95 /// a strong, exported symbol, consistent with historical treatment by
96 /// RuntimeDyld.
97 ///
98 /// Clients writing custom RTDyldMemoryManagers are encouraged to override
99 /// this method and return a SymbolInfo with the flags set correctly. This is
100 /// necessary for RuntimeDyld to correctly handle weak and non-exported symbols.
101 JITSymbol findSymbol(const std::string &Name) override {
102 return JITSymbol(getSymbolAddress(Name), JITSymbolFlags::Exported);
103 }
104
105 /// Legacy symbol lookup -- DEPRECATED! Please override
106 /// findSymbolInLogicalDylib instead.
107 ///
108 /// Default to treating all modules as separate.
109 virtual uint64_t getSymbolAddressInLogicalDylib(const std::string &Name) {
110 return 0;
111 }
112
113 /// Default to treating all modules as separate.
114 ///
115 /// By default this falls back on the legacy lookup method:
116 /// 'getSymbolAddressInLogicalDylib'. The address returned by
117 /// getSymbolAddressInLogicalDylib is treated as a strong, exported symbol,
118 /// consistent with historical treatment by RuntimeDyld.
119 ///
120 /// Clients writing custom RTDyldMemoryManagers are encouraged to override
121 /// this method and return a SymbolInfo with the flags set correctly. This is
122 /// necessary for RuntimeDyld to correctly handle weak and non-exported symbols.
123 JITSymbol
124 findSymbolInLogicalDylib(const std::string &Name) override {
125 return JITSymbol(getSymbolAddressInLogicalDylib(Name),
126 JITSymbolFlags::Exported);
127 }
128
129 /// This method returns the address of the specified function. As such it is
130 /// only useful for resolving library symbols, not code generated symbols.
131 ///
132 /// If \p AbortOnFailure is false and no function with the given name is
133 /// found, this function returns a null pointer. Otherwise, it prints a
134 /// message to stderr and aborts.
135 ///
136 /// This function is deprecated for memory managers to be used with
137 /// MCJIT or RuntimeDyld. Use getSymbolAddress instead.
138 virtual void *getPointerToNamedFunction(const std::string &Name,
139 bool AbortOnFailure = true);
140
141protected:
142 struct EHFrame {
143 uint8_t *Addr;
144 size_t Size;
145 };
146 typedef std::vector<EHFrame> EHFrameInfos;
147 EHFrameInfos EHFrames;
148
149private:
150 void anchor() override;
151};
152
153// Create wrappers for C Binding types (see CBindingWrapping.h).
154DEFINE_SIMPLE_CONVERSION_FUNCTIONS(
155 RTDyldMemoryManager, LLVMMCJITMemoryManagerRef)
156
157} // end namespace llvm
158
159#endif // LLVM_EXECUTIONENGINE_RTDYLDMEMORYMANAGER_H
160