1 //===-- ObjectLinkingLayer.h - JITLink-based jit linking layer --*- C++ -*-===//
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //===----------------------------------------------------------------------===//
9 // Contains the definition for an JITLink-based, in-process object linking
12 //===----------------------------------------------------------------------===//
14 #ifndef LLVM_EXECUTIONENGINE_ORC_OBJECTLINKINGLAYER_H
15 #define LLVM_EXECUTIONENGINE_ORC_OBJECTLINKINGLAYER_H
17 #include "llvm/ADT/STLExtras.h"
18 #include "llvm/ADT/StringMap.h"
19 #include "llvm/ADT/StringRef.h"
20 #include "llvm/ExecutionEngine/JITLink/JITLink.h"
21 #include "llvm/ExecutionEngine/JITSymbol.h"
22 #include "llvm/ExecutionEngine/Orc/Core.h"
23 #include "llvm/ExecutionEngine/Orc/Layer.h"
24 #include "llvm/Support/Error.h"
37 class EHFrameRegistrar;
39 } // namespace jitlink
47 class ObjectLinkingLayerJITLinkContext;
49 /// An ObjectLayer implementation built on JITLink.
51 /// Clients can use this class to add relocatable object files to an
52 /// ExecutionSession, and it typically serves as the base layer (underneath
53 /// a compiling layer like IRCompileLayer) for the rest of the JIT.
54 class ObjectLinkingLayer : public ObjectLayer {
55 friend class ObjectLinkingLayerJITLinkContext;
58 /// Plugin instances can be added to the ObjectLinkingLayer to receive
59 /// callbacks when code is loaded or emitted, and when JITLink is being
63 using JITLinkSymbolVector = std::vector<const jitlink::Symbol *>;
64 using LocalDependenciesMap = DenseMap<SymbolStringPtr, JITLinkSymbolVector>;
67 virtual void modifyPassConfig(MaterializationResponsibility &MR,
69 jitlink::PassConfiguration &Config) {}
71 virtual void notifyLoaded(MaterializationResponsibility &MR) {}
72 virtual Error notifyEmitted(MaterializationResponsibility &MR) {
73 return Error::success();
75 virtual Error notifyRemovingModule(VModuleKey K) {
76 return Error::success();
78 virtual Error notifyRemovingAllModules() { return Error::success(); }
80 /// Return any dependencies that synthetic symbols (e.g. init symbols)
81 /// have on locally scoped jitlink::Symbols. This is used by the
82 /// ObjectLinkingLayer to update the dependencies for the synthetic
84 virtual LocalDependenciesMap
85 getSyntheticSymbolLocalDependencies(MaterializationResponsibility &MR) {
86 return LocalDependenciesMap();
90 using ReturnObjectBufferFunction =
91 std::function<void(std::unique_ptr<MemoryBuffer>)>;
93 /// Construct an ObjectLinkingLayer with the given NotifyLoaded,
94 /// and NotifyEmitted functors.
95 ObjectLinkingLayer(ExecutionSession &ES,
96 std::unique_ptr<jitlink::JITLinkMemoryManager> MemMgr);
98 /// Destruct an ObjectLinkingLayer.
99 ~ObjectLinkingLayer();
101 /// Set an object buffer return function. By default object buffers are
102 /// deleted once the JIT has linked them. If a return function is set then
103 /// it will be called to transfer ownership of the buffer instead.
104 void setReturnObjectBuffer(ReturnObjectBufferFunction ReturnObjectBuffer) {
105 this->ReturnObjectBuffer = std::move(ReturnObjectBuffer);
108 /// Add a pass-config modifier.
109 ObjectLinkingLayer &addPlugin(std::unique_ptr<Plugin> P) {
110 std::lock_guard<std::mutex> Lock(LayerMutex);
111 Plugins.push_back(std::move(P));
116 void emit(MaterializationResponsibility R,
117 std::unique_ptr<MemoryBuffer> O) override;
119 /// Instructs this ObjectLinkingLayer instance to override the symbol flags
120 /// found in the AtomGraph with the flags supplied by the
121 /// MaterializationResponsibility instance. This is a workaround to support
122 /// symbol visibility in COFF, which does not use the libObject's
123 /// SF_Exported flag. Use only when generating / adding COFF object files.
125 /// FIXME: We should be able to remove this if/when COFF properly tracks
126 /// exported symbols.
128 setOverrideObjectFlagsWithResponsibilityFlags(bool OverrideObjectFlags) {
129 this->OverrideObjectFlags = OverrideObjectFlags;
133 /// If set, this ObjectLinkingLayer instance will claim responsibility
134 /// for any symbols provided by a given object file that were not already in
135 /// the MaterializationResponsibility instance. Setting this flag allows
136 /// higher-level program representations (e.g. LLVM IR) to be added based on
137 /// only a subset of the symbols they provide, without having to write
138 /// intervening layers to scan and add the additional symbols. This trades
139 /// diagnostic quality for convenience however: If all symbols are enumerated
140 /// up-front then clashes can be detected and reported early (and usually
141 /// deterministically). If this option is set, clashes for the additional
142 /// symbols may not be detected until late, and detection may depend on
143 /// the flow of control through JIT'd code. Use with care.
145 setAutoClaimResponsibilityForObjectSymbols(bool AutoClaimObjectSymbols) {
146 this->AutoClaimObjectSymbols = AutoClaimObjectSymbols;
151 using AllocPtr = std::unique_ptr<jitlink::JITLinkMemoryManager::Allocation>;
153 void modifyPassConfig(MaterializationResponsibility &MR, const Triple &TT,
154 jitlink::PassConfiguration &PassConfig);
155 void notifyLoaded(MaterializationResponsibility &MR);
156 Error notifyEmitted(MaterializationResponsibility &MR, AllocPtr Alloc);
158 Error removeModule(VModuleKey K);
159 Error removeAllModules();
161 mutable std::mutex LayerMutex;
162 std::unique_ptr<jitlink::JITLinkMemoryManager> MemMgr;
163 bool OverrideObjectFlags = false;
164 bool AutoClaimObjectSymbols = false;
165 ReturnObjectBufferFunction ReturnObjectBuffer;
166 DenseMap<VModuleKey, AllocPtr> TrackedAllocs;
167 std::vector<AllocPtr> UntrackedAllocs;
168 std::vector<std::unique_ptr<Plugin>> Plugins;
171 class EHFrameRegistrationPlugin : public ObjectLinkingLayer::Plugin {
173 EHFrameRegistrationPlugin(jitlink::EHFrameRegistrar &Registrar);
174 Error notifyEmitted(MaterializationResponsibility &MR) override;
175 void modifyPassConfig(MaterializationResponsibility &MR, const Triple &TT,
176 jitlink::PassConfiguration &PassConfig) override;
177 Error notifyRemovingModule(VModuleKey K) override;
178 Error notifyRemovingAllModules() override;
182 struct EHFrameRange {
183 JITTargetAddress Addr = 0;
187 std::mutex EHFramePluginMutex;
188 jitlink::EHFrameRegistrar &Registrar;
189 DenseMap<MaterializationResponsibility *, EHFrameRange> InProcessLinks;
190 DenseMap<VModuleKey, EHFrameRange> TrackedEHFrameRanges;
191 std::vector<EHFrameRange> UntrackedEHFrameRanges;
194 } // end namespace orc
195 } // end namespace llvm
197 #endif // LLVM_EXECUTIONENGINE_ORC_OBJECTLINKINGLAYER_H