llvm/include/llvm/ExecutionEngine/Orc/MachOPlatform.h

   1 //===-- MachOPlatform.h - Utilities for executing MachO in Orc --*- 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 // Utilities for executing JIT'd MachO in Orc.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #ifndef LLVM_EXECUTIONENGINE_ORC_MACHOPLATFORM_H
  14 #define LLVM_EXECUTIONENGINE_ORC_MACHOPLATFORM_H
  15
  16 #include "llvm/ADT/StringRef.h"
  17 #include "llvm/ExecutionEngine/Orc/Core.h"
  18 #include "llvm/ExecutionEngine/Orc/ExecutionUtils.h"
  19 #include "llvm/ExecutionEngine/Orc/ObjectLinkingLayer.h"
  20
  21 #include <future>
  22 #include <thread>
  23 #include <vector>
  24
  25 namespace llvm {
  26 namespace orc {
  27
  28 /// Enable registration of JIT'd ObjC classes and selectors.
  29 Error enableObjCRegistration(const char *PathToLibObjC);
  30 bool objCRegistrationEnabled();
  31
  32 class MachOJITDylibInitializers {
  33 public:
  34   struct SectionExtent {
  35     SectionExtent() = default;
  36     SectionExtent(JITTargetAddress Address, uint64_t NumPtrs)
  37         : Address(Address), NumPtrs(NumPtrs) {}
  38     JITTargetAddress Address = 0;
  39     uint64_t NumPtrs = 0;
  40   };
  41
  42   using RawPointerSectionList = std::vector<SectionExtent>;
  43
  44   void setObjCImageInfoAddr(JITTargetAddress ObjCImageInfoAddr) {
  45     this->ObjCImageInfoAddr = ObjCImageInfoAddr;
  46   }
  47
  48   void addModInitsSection(SectionExtent ModInit) {
  49     ModInitSections.push_back(std::move(ModInit));
  50   }
  51
  52   const RawPointerSectionList &getModInitsSections() const {
  53     return ModInitSections;
  54   }
  55
  56   void addObjCSelRefsSection(SectionExtent ObjCSelRefs) {
  57     ObjCSelRefsSections.push_back(std::move(ObjCSelRefs));
  58   }
  59
  60   const RawPointerSectionList &getObjCSelRefsSections() const {
  61     return ObjCSelRefsSections;
  62   }
  63
  64   void addObjCClassListSection(SectionExtent ObjCClassList) {
  65     ObjCClassListSections.push_back(std::move(ObjCClassList));
  66   }
  67
  68   const RawPointerSectionList &getObjCClassListSections() const {
  69     return ObjCClassListSections;
  70   }
  71
  72   void runModInits() const;
  73   void registerObjCSelectors() const;
  74   Error registerObjCClasses() const;
  75
  76 private:
  77
  78   JITTargetAddress ObjCImageInfoAddr;
  79   RawPointerSectionList ModInitSections;
  80   RawPointerSectionList ObjCSelRefsSections;
  81   RawPointerSectionList ObjCClassListSections;
  82 };
  83
  84 class MachOJITDylibDeinitializers {};
  85
  86 /// Mediates between MachO initialization and ExecutionSession state.
  87 class MachOPlatform : public Platform {
  88 public:
  89   using InitializerSequence =
  90       std::vector<std::pair<JITDylib *, MachOJITDylibInitializers>>;
  91
  92   using DeinitializerSequence =
  93       std::vector<std::pair<JITDylib *, MachOJITDylibDeinitializers>>;
  94
  95   MachOPlatform(ExecutionSession &ES, ObjectLinkingLayer &ObjLinkingLayer,
  96                 std::unique_ptr<MemoryBuffer> StandardSymbolsObject);
  97
  98   ExecutionSession &getExecutionSession() const { return ES; }
  99
 100   Error setupJITDylib(JITDylib &JD) override;
 101   Error notifyAdding(ResourceTracker &RT,
 102                      const MaterializationUnit &MU) override;
 103   Error notifyRemoving(ResourceTracker &RT) override;
 104
 105   Expected<InitializerSequence> getInitializerSequence(JITDylib &JD);
 106
 107   Expected<DeinitializerSequence> getDeinitializerSequence(JITDylib &JD);
 108
 109 private:
 110   // This ObjectLinkingLayer plugin scans JITLink graphs for __mod_init_func,
 111   // __objc_classlist and __sel_ref sections and records their extents so that
 112   // they can be run in the target process.
 113   class InitScraperPlugin : public ObjectLinkingLayer::Plugin {
 114   public:
 115     InitScraperPlugin(MachOPlatform &MP) : MP(MP) {}
 116
 117     void modifyPassConfig(MaterializationResponsibility &MR, const Triple &TT,
 118                           jitlink::PassConfiguration &Config) override;
 119
 120     LocalDependenciesMap getSyntheticSymbolLocalDependencies(
 121         MaterializationResponsibility &MR) override;
 122
 123     // FIXME: We should be tentatively tracking scraped sections and discarding
 124     // if the MR fails.
 125     Error notifyFailed(MaterializationResponsibility &MR) override {
 126       return Error::success();
 127     }
 128
 129     Error notifyRemovingResources(ResourceKey K) override {
 130       return Error::success();
 131     }
 132
 133     void notifyTransferringResources(ResourceKey DstKey,
 134                                      ResourceKey SrcKey) override {}
 135
 136   private:
 137     using InitSymbolDepMap =
 138         DenseMap<MaterializationResponsibility *, JITLinkSymbolVector>;
 139
 140     void preserveInitSectionIfPresent(JITLinkSymbolVector &Syms,
 141                                       jitlink::LinkGraph &G,
 142                                       StringRef SectionName);
 143
 144     Error processObjCImageInfo(jitlink::LinkGraph &G,
 145                                MaterializationResponsibility &MR);
 146
 147     std::mutex InitScraperMutex;
 148     MachOPlatform &MP;
 149     DenseMap<JITDylib *, std::pair<uint32_t, uint32_t>> ObjCImageInfos;
 150     InitSymbolDepMap InitSymbolDeps;
 151   };
 152
 153   void registerInitInfo(JITDylib &JD, JITTargetAddress ObjCImageInfoAddr,
 154                         MachOJITDylibInitializers::SectionExtent ModInits,
 155                         MachOJITDylibInitializers::SectionExtent ObjCSelRefs,
 156                         MachOJITDylibInitializers::SectionExtent ObjCClassList);
 157
 158   ExecutionSession &ES;
 159   ObjectLinkingLayer &ObjLinkingLayer;
 160   std::unique_ptr<MemoryBuffer> StandardSymbolsObject;
 161
 162   DenseMap<JITDylib *, SymbolLookupSet> RegisteredInitSymbols;
 163
 164   // InitSeqs gets its own mutex to avoid locking the whole session when
 165   // aggregating data from the jitlink.
 166   std::mutex InitSeqsMutex;
 167   DenseMap<JITDylib *, MachOJITDylibInitializers> InitSeqs;
 168 };
 169
 170 } // end namespace orc
 171 } // end namespace llvm
 172
 173 #endif // LLVM_EXECUTIONENGINE_ORC_MACHOPLATFORM_H