Andrew Walbran | 3d2c197 | 2020-04-07 12:24:26 +0100 | [diff] [blame^] | 1 | //===-- ObjectLinkingLayer.h - JITLink-based jit linking layer --*- 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 | // Contains the definition for an JITLink-based, in-process object linking |
| 10 | // layer. |
| 11 | // |
| 12 | //===----------------------------------------------------------------------===// |
| 13 | |
| 14 | #ifndef LLVM_EXECUTIONENGINE_ORC_OBJECTLINKINGLAYER_H |
| 15 | #define LLVM_EXECUTIONENGINE_ORC_OBJECTLINKINGLAYER_H |
| 16 | |
| 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" |
| 25 | #include <algorithm> |
| 26 | #include <cassert> |
| 27 | #include <functional> |
| 28 | #include <list> |
| 29 | #include <memory> |
| 30 | #include <string> |
| 31 | #include <utility> |
| 32 | #include <vector> |
| 33 | |
| 34 | namespace llvm { |
| 35 | |
| 36 | namespace jitlink { |
| 37 | class EHFrameRegistrar; |
| 38 | } // namespace jitlink |
| 39 | |
| 40 | namespace object { |
| 41 | class ObjectFile; |
| 42 | } // namespace object |
| 43 | |
| 44 | namespace orc { |
| 45 | |
| 46 | class ObjectLinkingLayerJITLinkContext; |
| 47 | |
| 48 | /// An ObjectLayer implementation built on JITLink. |
| 49 | /// |
| 50 | /// Clients can use this class to add relocatable object files to an |
| 51 | /// ExecutionSession, and it typically serves as the base layer (underneath |
| 52 | /// a compiling layer like IRCompileLayer) for the rest of the JIT. |
| 53 | class ObjectLinkingLayer : public ObjectLayer { |
| 54 | friend class ObjectLinkingLayerJITLinkContext; |
| 55 | |
| 56 | public: |
| 57 | /// Plugin instances can be added to the ObjectLinkingLayer to receive |
| 58 | /// callbacks when code is loaded or emitted, and when JITLink is being |
| 59 | /// configured. |
| 60 | class Plugin { |
| 61 | public: |
| 62 | virtual ~Plugin(); |
| 63 | virtual void modifyPassConfig(MaterializationResponsibility &MR, |
| 64 | const Triple &TT, |
| 65 | jitlink::PassConfiguration &Config) {} |
| 66 | virtual void notifyLoaded(MaterializationResponsibility &MR) {} |
| 67 | virtual Error notifyEmitted(MaterializationResponsibility &MR) { |
| 68 | return Error::success(); |
| 69 | } |
| 70 | virtual Error notifyRemovingModule(VModuleKey K) { |
| 71 | return Error::success(); |
| 72 | } |
| 73 | virtual Error notifyRemovingAllModules() { return Error::success(); } |
| 74 | }; |
| 75 | |
| 76 | /// Construct an ObjectLinkingLayer with the given NotifyLoaded, |
| 77 | /// and NotifyEmitted functors. |
| 78 | ObjectLinkingLayer(ExecutionSession &ES, |
| 79 | jitlink::JITLinkMemoryManager &MemMgr); |
| 80 | |
| 81 | /// Destruct an ObjectLinkingLayer. |
| 82 | ~ObjectLinkingLayer(); |
| 83 | |
| 84 | /// Add a pass-config modifier. |
| 85 | ObjectLinkingLayer &addPlugin(std::unique_ptr<Plugin> P) { |
| 86 | std::lock_guard<std::mutex> Lock(LayerMutex); |
| 87 | Plugins.push_back(std::move(P)); |
| 88 | return *this; |
| 89 | } |
| 90 | |
| 91 | /// Emit the object. |
| 92 | void emit(MaterializationResponsibility R, |
| 93 | std::unique_ptr<MemoryBuffer> O) override; |
| 94 | |
| 95 | /// Instructs this ObjectLinkingLayer instance to override the symbol flags |
| 96 | /// found in the AtomGraph with the flags supplied by the |
| 97 | /// MaterializationResponsibility instance. This is a workaround to support |
| 98 | /// symbol visibility in COFF, which does not use the libObject's |
| 99 | /// SF_Exported flag. Use only when generating / adding COFF object files. |
| 100 | /// |
| 101 | /// FIXME: We should be able to remove this if/when COFF properly tracks |
| 102 | /// exported symbols. |
| 103 | ObjectLinkingLayer & |
| 104 | setOverrideObjectFlagsWithResponsibilityFlags(bool OverrideObjectFlags) { |
| 105 | this->OverrideObjectFlags = OverrideObjectFlags; |
| 106 | return *this; |
| 107 | } |
| 108 | |
| 109 | /// If set, this ObjectLinkingLayer instance will claim responsibility |
| 110 | /// for any symbols provided by a given object file that were not already in |
| 111 | /// the MaterializationResponsibility instance. Setting this flag allows |
| 112 | /// higher-level program representations (e.g. LLVM IR) to be added based on |
| 113 | /// only a subset of the symbols they provide, without having to write |
| 114 | /// intervening layers to scan and add the additional symbols. This trades |
| 115 | /// diagnostic quality for convenience however: If all symbols are enumerated |
| 116 | /// up-front then clashes can be detected and reported early (and usually |
| 117 | /// deterministically). If this option is set, clashes for the additional |
| 118 | /// symbols may not be detected until late, and detection may depend on |
| 119 | /// the flow of control through JIT'd code. Use with care. |
| 120 | ObjectLinkingLayer & |
| 121 | setAutoClaimResponsibilityForObjectSymbols(bool AutoClaimObjectSymbols) { |
| 122 | this->AutoClaimObjectSymbols = AutoClaimObjectSymbols; |
| 123 | return *this; |
| 124 | } |
| 125 | |
| 126 | private: |
| 127 | using AllocPtr = std::unique_ptr<jitlink::JITLinkMemoryManager::Allocation>; |
| 128 | |
| 129 | void modifyPassConfig(MaterializationResponsibility &MR, const Triple &TT, |
| 130 | jitlink::PassConfiguration &PassConfig); |
| 131 | void notifyLoaded(MaterializationResponsibility &MR); |
| 132 | Error notifyEmitted(MaterializationResponsibility &MR, AllocPtr Alloc); |
| 133 | |
| 134 | Error removeModule(VModuleKey K); |
| 135 | Error removeAllModules(); |
| 136 | |
| 137 | mutable std::mutex LayerMutex; |
| 138 | jitlink::JITLinkMemoryManager &MemMgr; |
| 139 | bool OverrideObjectFlags = false; |
| 140 | bool AutoClaimObjectSymbols = false; |
| 141 | DenseMap<VModuleKey, AllocPtr> TrackedAllocs; |
| 142 | std::vector<AllocPtr> UntrackedAllocs; |
| 143 | std::vector<std::unique_ptr<Plugin>> Plugins; |
| 144 | }; |
| 145 | |
| 146 | class EHFrameRegistrationPlugin : public ObjectLinkingLayer::Plugin { |
| 147 | public: |
| 148 | EHFrameRegistrationPlugin(jitlink::EHFrameRegistrar &Registrar); |
| 149 | Error notifyEmitted(MaterializationResponsibility &MR) override; |
| 150 | void modifyPassConfig(MaterializationResponsibility &MR, const Triple &TT, |
| 151 | jitlink::PassConfiguration &PassConfig) override; |
| 152 | Error notifyRemovingModule(VModuleKey K) override; |
| 153 | Error notifyRemovingAllModules() override; |
| 154 | |
| 155 | private: |
| 156 | jitlink::EHFrameRegistrar &Registrar; |
| 157 | DenseMap<MaterializationResponsibility *, JITTargetAddress> InProcessLinks; |
| 158 | DenseMap<VModuleKey, JITTargetAddress> TrackedEHFrameAddrs; |
| 159 | std::vector<JITTargetAddress> UntrackedEHFrameAddrs; |
| 160 | }; |
| 161 | |
| 162 | } // end namespace orc |
| 163 | } // end namespace llvm |
| 164 | |
| 165 | #endif // LLVM_EXECUTIONENGINE_ORC_OBJECTLINKINGLAYER_H |