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//===--- COFFPlatform.h -- Utilities for executing COFF in Orc --*- C++ -*-===//

//

// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.

// See https://llvm.org/LICENSE.txt for license information.

// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

//

//===----------------------------------------------------------------------===//

//

// Utilities for executing JIT'd COFF in Orc.

//

//===----------------------------------------------------------------------===//

#ifndef LLVM_EXECUTIONENGINE_ORC_COFFPLATFORM_H

#define LLVM_EXECUTIONENGINE_ORC_COFFPLATFORM_H

#include "llvm/ADT/StringRef.h"

#include "llvm/ExecutionEngine/Orc/COFFVCRuntimeSupport.h"

#include "llvm/ExecutionEngine/Orc/Core.h"

#include "llvm/ExecutionEngine/Orc/ExecutionUtils.h"

#include "llvm/ExecutionEngine/Orc/ExecutorProcessControl.h"

#include "llvm/ExecutionEngine/Orc/ObjectLinkingLayer.h"

#include "llvm/ExecutionEngine/Orc/Shared/ExecutorAddress.h"

#include <future>

#include <memory>

#include <thread>

#include <vector>

namespace llvm {

namespace orc {

/// Mediates between COFF initialization and ExecutionSession state.

class COFFPlatform : public Platform {

public:

  /// A function that will be called with the name of dll file that must be

  /// loaded.

  using LoadDynamicLibrary =

      unique_function<Error(JITDylib &JD, StringRef DLLFileName)>;

  /// Try to create a COFFPlatform instance, adding the ORC runtime to the

  /// given JITDylib.

  static Expected<std::unique_ptr<COFFPlatform>>

  Create(ExecutionSession &ES, ObjectLinkingLayer &ObjLinkingLayer,

         JITDylib &PlatformJD, const char *OrcRuntimePath,

         LoadDynamicLibrary LoadDynLibrary, bool StaticVCRuntime = false,

         const char *VCRuntimePath = nullptr,

         std::optional<SymbolAliasMap> RuntimeAliases = std::nullopt);

  ExecutionSession &getExecutionSession() const { return ES; }

  ObjectLinkingLayer &getObjectLinkingLayer() const { return ObjLinkingLayer; }

  Error setupJITDylib(JITDylib &JD) override;

  Error teardownJITDylib(JITDylib &JD) override;

  Error notifyAdding(ResourceTracker &RT,

                     const MaterializationUnit &MU) override;

  Error notifyRemoving(ResourceTracker &RT) override;

  /// Returns an AliasMap containing the default aliases for the COFFPlatform.

  /// This can be modified by clients when constructing the platform to add

  /// or remove aliases.

  static SymbolAliasMap standardPlatformAliases(ExecutionSession &ES);

  /// Returns the array of required CXX aliases.

  static ArrayRef<std::pair<const char *, const char *>> requiredCXXAliases();

  /// Returns the array of standard runtime utility aliases for COFF.

  static ArrayRef<std::pair<const char *, const char *>>

  standardRuntimeUtilityAliases();

  static bool isInitializerSection(StringRef Name) {

    return Name.startswith(".CRT");

  }

  static StringRef getSEHFrameSectionName() { return ".pdata"; }

private:

  using COFFJITDylibDepInfo = std::vector<ExecutorAddr>;

  using COFFJITDylibDepInfoMap =

      std::vector<std::pair<ExecutorAddr, COFFJITDylibDepInfo>>;

  using COFFObjectSectionsMap =

      SmallVector<std::pair<std::string, ExecutorAddrRange>>;

  using PushInitializersSendResultFn =

      unique_function<void(Expected<COFFJITDylibDepInfoMap>)>;

  using SendSymbolAddressFn = unique_function<void(Expected<ExecutorAddr>)>;

  using JITDylibDepMap = DenseMap<JITDylib *, SmallVector<JITDylib *>>;

  // The COFFPlatformPlugin scans/modifies LinkGraphs to support COFF

  // platform features including initializers, exceptions, and language

  // runtime registration.

  class COFFPlatformPlugin : public ObjectLinkingLayer::Plugin {

  public:

    COFFPlatformPlugin(COFFPlatform &CP) : CP(CP) {}

    void modifyPassConfig(MaterializationResponsibility &MR,

                          jitlink::LinkGraph &G,

                          jitlink::PassConfiguration &Config) override;

    SyntheticSymbolDependenciesMap

    getSyntheticSymbolDependencies(MaterializationResponsibility &MR) override;

    // FIXME: We should be tentatively tracking scraped sections and discarding

    // if the MR fails.

    Error notifyFailed(MaterializationResponsibility &MR) override {

      return Error::success();

    }

    Error notifyRemovingResources(JITDylib &JD, ResourceKey K) override {

      return Error::success();

    }

    void notifyTransferringResources(JITDylib &JD, ResourceKey DstKey,

                                     ResourceKey SrcKey) override {}

  private:

    using InitSymbolDepMap =

        DenseMap<MaterializationResponsibility *, JITLinkSymbolSet>;

    Error associateJITDylibHeaderSymbol(jitlink::LinkGraph &G,

                                        MaterializationResponsibility &MR,

                                        bool Bootstrap);

    Error preserveInitializerSections(jitlink::LinkGraph &G,

                                      MaterializationResponsibility &MR);

    Error registerObjectPlatformSections(jitlink::LinkGraph &G, JITDylib &JD);

    Error registerObjectPlatformSectionsInBootstrap(jitlink::LinkGraph &G,

                                                    JITDylib &JD);

    std::mutex PluginMutex;

    COFFPlatform &CP;

    InitSymbolDepMap InitSymbolDeps;

  };

  struct JDBootstrapState {

    JITDylib *JD = nullptr;

    std::string JDName;

    ExecutorAddr HeaderAddr;

    std::list<COFFObjectSectionsMap> ObjectSectionsMaps;

    SmallVector<std::pair<std::string, ExecutorAddr>> Initializers;

  };

  static bool supportedTarget(const Triple &TT);

  COFFPlatform(ExecutionSession &ES, ObjectLinkingLayer &ObjLinkingLayer,

               JITDylib &PlatformJD, const char *OrcRuntimePath,

               LoadDynamicLibrary LoadDynLibrary, bool StaticVCRuntime,

               const char *VCRuntimePath, Error &Err);

  // Associate COFFPlatform JIT-side runtime support functions with handlers.

  Error associateRuntimeSupportFunctions(JITDylib &PlatformJD);

  // Records the addresses of runtime symbols used by the platform.

  Error bootstrapCOFFRuntime(JITDylib &PlatformJD);

  // Run a specific void function if it exists.

  Error runSymbolIfExists(JITDylib &PlatformJD, StringRef SymbolName);

  // Run collected initializers in boostrap stage.

  Error runBootstrapInitializers(JDBootstrapState &BState);

  Error runBootstrapSubsectionInitializers(JDBootstrapState &BState,

                                           StringRef Start, StringRef End);

  // Build dependency graph of a JITDylib

  Expected<JITDylibDepMap> buildJDDepMap(JITDylib &JD);

  Expected<MemoryBufferRef> getPerJDObjectFile();

  // Implements rt_pushInitializers by making repeat async lookups for

  // initializer symbols (each lookup may spawn more initializer symbols if

  // it pulls in new materializers, e.g. from objects in a static library).

  void pushInitializersLoop(PushInitializersSendResultFn SendResult,

                            JITDylibSP JD, JITDylibDepMap &JDDepMap);

  void rt_pushInitializers(PushInitializersSendResultFn SendResult,

                           ExecutorAddr JDHeaderAddr);

  void rt_lookupSymbol(SendSymbolAddressFn SendResult, ExecutorAddr Handle,

                       StringRef SymbolName);

  ExecutionSession &ES;

  ObjectLinkingLayer &ObjLinkingLayer;

  LoadDynamicLibrary LoadDynLibrary;

  std::unique_ptr<COFFVCRuntimeBootstrapper> VCRuntimeBootstrap;

  std::unique_ptr<MemoryBuffer> OrcRuntimeArchiveBuffer;

  std::unique_ptr<object::Archive> OrcRuntimeArchive;

  bool StaticVCRuntime;

  SymbolStringPtr COFFHeaderStartSymbol;

  // State of bootstrap in progress

  std::map<JITDylib *, JDBootstrapState> JDBootstrapStates;

  std::atomic<bool> Bootstrapping;

  ExecutorAddr orc_rt_coff_platform_bootstrap;

  ExecutorAddr orc_rt_coff_platform_shutdown;

  ExecutorAddr orc_rt_coff_register_object_sections;

  ExecutorAddr orc_rt_coff_deregister_object_sections;

  ExecutorAddr orc_rt_coff_register_jitdylib;

  ExecutorAddr orc_rt_coff_deregister_jitdylib;

  DenseMap<JITDylib *, ExecutorAddr> JITDylibToHeaderAddr;

  DenseMap<ExecutorAddr, JITDylib *> HeaderAddrToJITDylib;

  DenseMap<JITDylib *, SymbolLookupSet> RegisteredInitSymbols;

  std::set<std::string> DylibsToPreload;

  std::mutex PlatformMutex;

};

} // end namespace orc

} // end namespace llvm

#endif // LLVM_EXECUTIONENGINE_ORC_COFFPLATFORM_H