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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 :
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.
48 241 : virtual void notifyObjectLoaded(ExecutionEngine *EE,
49 241 : const object::ObjectFile &) {}
50 :
51 : private:
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.
61 : class RTDyldMemoryManager : public MCJITMemoryManager,
62 : public LegacyJITSymbolResolver {
63 : public:
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.
86 220 : virtual uint64_t getSymbolAddress(const std::string &Name) {
87 220 : 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.
101 220 : JITSymbol findSymbol(const std::string &Name) override {
102 220 : 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.
109 104 : virtual uint64_t getSymbolAddressInLogicalDylib(const std::string &Name) {
110 104 : 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
124 104 : findSymbolInLogicalDylib(const std::string &Name) override {
125 104 : return JITSymbol(getSymbolAddressInLogicalDylib(Name),
126 104 : 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 :
141 : protected:
142 : struct EHFrame {
143 : uint8_t *Addr;
144 : size_t Size;
145 : };
146 : typedef std::vector<EHFrame> EHFrameInfos;
147 : EHFrameInfos EHFrames;
148 :
149 : private:
150 : void anchor() override;
151 : };
152 :
153 : // Create wrappers for C Binding types (see CBindingWrapping.h).
154 : DEFINE_SIMPLE_CONVERSION_FUNCTIONS(
155 : RTDyldMemoryManager, LLVMMCJITMemoryManagerRef)
156 :
157 : } // end namespace llvm
158 :
159 : #endif // LLVM_EXECUTIONENGINE_RTDYLDMEMORYMANAGER_H
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