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| 1 | +//===-- LinkGraphLinkingLayer.h - Link LinkGraphs with JITLink --*- C++ -*-===// |
| 2 | +// |
| 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 |
| 6 | +// |
| 7 | +//===----------------------------------------------------------------------===// |
| 8 | +// |
| 9 | +// LinkGraphLinkingLayer and associated utilities. |
| 10 | +// |
| 11 | +//===----------------------------------------------------------------------===// |
| 12 | + |
| 13 | +#ifndef LLVM_EXECUTIONENGINE_ORC_LINKGRAPHLINKINGLAYER_H |
| 14 | +#define LLVM_EXECUTIONENGINE_ORC_LINKGRAPHLINKINGLAYER_H |
| 15 | + |
| 16 | +#include "llvm/ADT/STLExtras.h" |
| 17 | +#include "llvm/ADT/StringRef.h" |
| 18 | +#include "llvm/ExecutionEngine/JITLink/JITLinkMemoryManager.h" |
| 19 | +#include "llvm/ExecutionEngine/Orc/Core.h" |
| 20 | +#include "llvm/ExecutionEngine/Orc/Layer.h" |
| 21 | +#include "llvm/ExecutionEngine/Orc/LinkGraphLayer.h" |
| 22 | +#include "llvm/Support/Error.h" |
| 23 | +#include <algorithm> |
| 24 | +#include <cassert> |
| 25 | +#include <functional> |
| 26 | +#include <memory> |
| 27 | +#include <mutex> |
| 28 | +#include <utility> |
| 29 | +#include <vector> |
| 30 | + |
| 31 | +namespace llvm { |
| 32 | + |
| 33 | +namespace jitlink { |
| 34 | +class EHFrameRegistrar; |
| 35 | +} // namespace jitlink |
| 36 | + |
| 37 | +namespace orc { |
| 38 | + |
| 39 | +/// LinkGraphLinkingLayer links LinkGraphs into the Executor using JITLink. |
| 40 | +/// |
| 41 | +/// Clients can use this class to add LinkGraphs to an ExecutionSession, and it |
| 42 | +/// serves as a base for the ObjectLinkingLayer that can link object files. |
| 43 | +class LinkGraphLinkingLayer : public LinkGraphLayer, private ResourceManager { |
| 44 | + class JITLinkCtx; |
| 45 | + |
| 46 | +public: |
| 47 | + /// Plugin instances can be added to the ObjectLinkingLayer to receive |
| 48 | + /// callbacks when code is loaded or emitted, and when JITLink is being |
| 49 | + /// configured. |
| 50 | + class Plugin { |
| 51 | + public: |
| 52 | + virtual ~Plugin(); |
| 53 | + virtual void modifyPassConfig(MaterializationResponsibility &MR, |
| 54 | + jitlink::LinkGraph &G, |
| 55 | + jitlink::PassConfiguration &Config) {} |
| 56 | + |
| 57 | + // Deprecated. Don't use this in new code. There will be a proper mechanism |
| 58 | + // for capturing object buffers. |
| 59 | + virtual void notifyMaterializing(MaterializationResponsibility &MR, |
| 60 | + jitlink::LinkGraph &G, |
| 61 | + jitlink::JITLinkContext &Ctx, |
| 62 | + MemoryBufferRef InputObject) {} |
| 63 | + |
| 64 | + virtual void notifyLoaded(MaterializationResponsibility &MR) {} |
| 65 | + virtual Error notifyEmitted(MaterializationResponsibility &MR) { |
| 66 | + return Error::success(); |
| 67 | + } |
| 68 | + virtual Error notifyFailed(MaterializationResponsibility &MR) = 0; |
| 69 | + virtual Error notifyRemovingResources(JITDylib &JD, ResourceKey K) = 0; |
| 70 | + virtual void notifyTransferringResources(JITDylib &JD, ResourceKey DstKey, |
| 71 | + ResourceKey SrcKey) = 0; |
| 72 | + }; |
| 73 | + |
| 74 | + /// Construct a LinkGraphLinkingLayer using the ExecutorProcessControl |
| 75 | + /// instance's memory manager. |
| 76 | + LinkGraphLinkingLayer(ExecutionSession &ES); |
| 77 | + |
| 78 | + /// Construct a LinkGraphLinkingLayer using a custom memory manager. |
| 79 | + LinkGraphLinkingLayer(ExecutionSession &ES, |
| 80 | + jitlink::JITLinkMemoryManager &MemMgr); |
| 81 | + |
| 82 | + /// Construct an LinkGraphLinkingLayer. Takes ownership of the given |
| 83 | + /// JITLinkMemoryManager. This method is a temporary hack to simplify |
| 84 | + /// co-existence with RTDyldObjectLinkingLayer (which also owns its |
| 85 | + /// allocators). |
| 86 | + LinkGraphLinkingLayer(ExecutionSession &ES, |
| 87 | + std::unique_ptr<jitlink::JITLinkMemoryManager> MemMgr); |
| 88 | + |
| 89 | + /// Destroy the LinkGraphLinkingLayer. |
| 90 | + ~LinkGraphLinkingLayer(); |
| 91 | + |
| 92 | + /// Add a plugin. |
| 93 | + LinkGraphLinkingLayer & addPlugin(std::shared_ptr<Plugin> P) { |
| 94 | + std::lock_guard<std::mutex> Lock(LayerMutex); |
| 95 | + Plugins.push_back(std::move(P)); |
| 96 | + return *this; |
| 97 | + } |
| 98 | + |
| 99 | + /// Remove a plugin. This remove applies only to subsequent links (links |
| 100 | + /// already underway will continue to use the plugin), and does not of itself |
| 101 | + /// destroy the plugin -- destruction will happen once all shared pointers |
| 102 | + /// (including those held by in-progress links) are destroyed. |
| 103 | + void removePlugin(Plugin &P) { |
| 104 | + std::lock_guard<std::mutex> Lock(LayerMutex); |
| 105 | + auto I = llvm::find_if(Plugins, [&]( const std::shared_ptr<Plugin> &Elem) { |
| 106 | + return Elem.get() == &P; |
| 107 | + }); |
| 108 | + assert(I != Plugins.end() && "Plugin not present"); |
| 109 | + Plugins.erase(I); |
| 110 | + } |
| 111 | + |
| 112 | + /// Emit a LinkGraph. |
| 113 | + void emit(std::unique_ptr<MaterializationResponsibility> R, |
| 114 | + std::unique_ptr<jitlink::LinkGraph> G) override; |
| 115 | + |
| 116 | + /// Instructs this LinkgraphLinkingLayer instance to override the symbol flags |
| 117 | + /// found in the LinkGraph with the flags supplied by the |
| 118 | + /// MaterializationResponsibility instance. This is a workaround to support |
| 119 | + /// symbol visibility in COFF, which does not use the libObject's |
| 120 | + /// SF_Exported flag. Use only when generating / adding COFF object files. |
| 121 | + /// |
| 122 | + /// FIXME: We should be able to remove this if/when COFF properly tracks |
| 123 | + /// exported symbols. |
| 124 | + LinkGraphLinkingLayer & |
| 125 | + setOverrideObjectFlagsWithResponsibilityFlags(bool OverrideObjectFlags) { |
| 126 | + this->OverrideObjectFlags = OverrideObjectFlags; |
| 127 | + return *this; |
| 128 | + } |
| 129 | + |
| 130 | + /// If set, this LinkGraphLinkingLayer instance will claim responsibility |
| 131 | + /// for any symbols provided by a given object file that were not already in |
| 132 | + /// the MaterializationResponsibility instance. Setting this flag allows |
| 133 | + /// higher-level program representations (e.g. LLVM IR) to be added based on |
| 134 | + /// only a subset of the symbols they provide, without having to write |
| 135 | + /// intervening layers to scan and add the additional symbols. This trades |
| 136 | + /// diagnostic quality for convenience however: If all symbols are enumerated |
| 137 | + /// up-front then clashes can be detected and reported early (and usually |
| 138 | + /// deterministically). If this option is set, clashes for the additional |
| 139 | + /// symbols may not be detected until late, and detection may depend on |
| 140 | + /// the flow of control through JIT'd code. Use with care. |
| 141 | + LinkGraphLinkingLayer & |
| 142 | + setAutoClaimResponsibilityForObjectSymbols(bool AutoClaimObjectSymbols) { |
| 143 | + this->AutoClaimObjectSymbols = AutoClaimObjectSymbols; |
| 144 | + return *this; |
| 145 | + } |
| 146 | + |
| 147 | +protected: |
| 148 | + /// Emit a LinkGraph with the given backing buffer. |
| 149 | + /// |
| 150 | + /// This overload is intended for use by ObjectLinkingLayer. |
| 151 | + void emit(std::unique_ptr<MaterializationResponsibility> R, |
| 152 | + std::unique_ptr<jitlink::LinkGraph> G, |
| 153 | + std::unique_ptr<MemoryBuffer> ObjBuf); |
| 154 | + |
| 155 | + std::function<void(std::unique_ptr<MemoryBuffer>)> ReturnObjectBuffer; |
| 156 | + |
| 157 | +private: |
| 158 | + using FinalizedAlloc = jitlink::JITLinkMemoryManager::FinalizedAlloc; |
| 159 | + |
| 160 | + Error recordFinalizedAlloc(MaterializationResponsibility &MR, |
| 161 | + FinalizedAlloc FA); |
| 162 | + |
| 163 | + Error handleRemoveResources(JITDylib &JD, ResourceKey K) override; |
| 164 | + void handleTransferResources(JITDylib &JD, ResourceKey DstKey, |
| 165 | + ResourceKey SrcKey) override; |
| 166 | + |
| 167 | + mutable std::mutex LayerMutex; |
| 168 | + jitlink::JITLinkMemoryManager &MemMgr; |
| 169 | + std::unique_ptr<jitlink::JITLinkMemoryManager> MemMgrOwnership; |
| 170 | + bool OverrideObjectFlags = false; |
| 171 | + bool AutoClaimObjectSymbols = false; |
| 172 | + DenseMap<ResourceKey, std::vector<FinalizedAlloc>> Allocs; |
| 173 | + std::vector<std::shared_ptr<Plugin>> Plugins; |
| 174 | +}; |
| 175 | + |
| 176 | +class EHFrameRegistrationPlugin : public LinkGraphLinkingLayer::Plugin { |
| 177 | +public: |
| 178 | + EHFrameRegistrationPlugin( |
| 179 | + ExecutionSession &ES, |
| 180 | + std::unique_ptr<jitlink::EHFrameRegistrar> Registrar); |
| 181 | + void modifyPassConfig(MaterializationResponsibility &MR, |
| 182 | + jitlink::LinkGraph &G, |
| 183 | + jitlink::PassConfiguration &PassConfig) override; |
| 184 | + Error notifyEmitted(MaterializationResponsibility &MR) override; |
| 185 | + Error notifyFailed(MaterializationResponsibility &MR) override; |
| 186 | + Error notifyRemovingResources(JITDylib &JD, ResourceKey K) override; |
| 187 | + void notifyTransferringResources(JITDylib &JD, ResourceKey DstKey, |
| 188 | + ResourceKey SrcKey) override; |
| 189 | + |
| 190 | +private: |
| 191 | + std::mutex EHFramePluginMutex; |
| 192 | + ExecutionSession &ES; |
| 193 | + std::unique_ptr<jitlink::EHFrameRegistrar> Registrar; |
| 194 | + DenseMap<MaterializationResponsibility *, ExecutorAddrRange> InProcessLinks; |
| 195 | + DenseMap<ResourceKey, std::vector<ExecutorAddrRange>> EHFrameRanges; |
| 196 | +}; |
| 197 | + |
| 198 | +} // end namespace orc |
| 199 | +} // end namespace llvm |
| 200 | + |
| 201 | +#endif // LLVM_EXECUTIONENGINE_ORC_LINKGRAPHLINKINGLAYER_H |
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