//===---- llvm-jitlink.h - Session and format-specific decls ----*- 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
//
//===----------------------------------------------------------------------===//
//
// llvm-jitlink Session class and tool utilities.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_TOOLS_LLVM_JITLINK_LLVM_JITLINK_H
#define LLVM_TOOLS_LLVM_JITLINK_LLVM_JITLINK_H

#include "llvm/ADT/StringSet.h"
#include "llvm/ExecutionEngine/Orc/Core.h"
#include "llvm/ExecutionEngine/Orc/EPCIndirectionUtils.h"
#include "llvm/ExecutionEngine/Orc/ExecutorProcessControl.h"
#include "llvm/ExecutionEngine/Orc/LazyObjectLinkingLayer.h"
#include "llvm/ExecutionEngine/Orc/ObjectLinkingLayer.h"
#include "llvm/ExecutionEngine/Orc/RedirectionManager.h"
#include "llvm/ExecutionEngine/Orc/SimpleRemoteEPC.h"
#include "llvm/ExecutionEngine/RuntimeDyldChecker.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/Regex.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/TargetParser/SubtargetFeature.h"
#include "llvm/TargetParser/Triple.h"

namespace llvm {

struct Session {

  struct LazyLinkingSupport {
    LazyLinkingSupport(std::unique_ptr<orc::EPCIndirectionUtils> EPCIU,
                       std::unique_ptr<orc::RedirectableSymbolManager> RSMgr,
                       orc::ObjectLinkingLayer &ObjLinkingLayer)
        : EPCIU(std::move(EPCIU)), RSMgr(std::move(RSMgr)),
          LazyObjLinkingLayer(ObjLinkingLayer,
                              this->EPCIU->getLazyCallThroughManager(),
                              *this->RSMgr) {}
    ~LazyLinkingSupport() {
      if (auto Err = EPCIU->cleanup())
        LazyObjLinkingLayer.getExecutionSession().reportError(std::move(Err));
    }

    std::unique_ptr<orc::EPCIndirectionUtils> EPCIU;
    std::unique_ptr<orc::RedirectableSymbolManager> RSMgr;
    orc::LazyObjectLinkingLayer LazyObjLinkingLayer;
  };

  orc::ExecutionSession ES;
  orc::JITDylib *MainJD = nullptr;
  orc::JITDylib *ProcessSymsJD = nullptr;
  orc::JITDylib *PlatformJD = nullptr;
  orc::ObjectLinkingLayer ObjLayer;
  std::unique_ptr<LazyLinkingSupport> LazyLinking;
  orc::JITDylibSearchOrder JDSearchOrder;
  SubtargetFeatures Features;

  ~Session();

  static Expected<std::unique_ptr<Session>> Create(Triple TT,
                                                   SubtargetFeatures Features);
  void dumpSessionInfo(raw_ostream &OS);
  void modifyPassConfig(jitlink::LinkGraph &G,
                        jitlink::PassConfiguration &PassConfig);

  using MemoryRegionInfo = RuntimeDyldChecker::MemoryRegionInfo;

  struct FileInfo {
    StringMap<MemoryRegionInfo> SectionInfos;
    StringMap<SmallVector<MemoryRegionInfo, 1>> StubInfos;
    StringMap<MemoryRegionInfo> GOTEntryInfos;

    using Symbol = jitlink::Symbol;
    using LinkGraph = jitlink::LinkGraph;
    using GetSymbolTargetFunction =
        unique_function<Expected<Symbol &>(LinkGraph &G, jitlink::Block &)>;
    Error registerGOTEntry(LinkGraph &G, Symbol &Sym,
                           GetSymbolTargetFunction GetSymbolTarget);
    Error registerStubEntry(LinkGraph &G, Symbol &Sym,
                            GetSymbolTargetFunction GetSymbolTarget);
    Error registerMultiStubEntry(LinkGraph &G, Symbol &Sym,
                                 GetSymbolTargetFunction GetSymbolTarget);
  };

  using DynLibJDMap = std::map<std::string, orc::JITDylib *, std::less<>>;
  using SymbolInfoMap = DenseMap<orc::SymbolStringPtr, MemoryRegionInfo>;
  using FileInfoMap = StringMap<FileInfo>;

  Expected<orc::JITDylib *> getOrLoadDynamicLibrary(StringRef LibPath);
  Error loadAndLinkDynamicLibrary(orc::JITDylib &JD, StringRef LibPath);

  orc::ObjectLayer &getLinkLayer(bool Lazy) {
    assert((!Lazy || LazyLinking) &&
           "Lazy linking requested but not available");
    return Lazy ? static_cast<orc::ObjectLayer &>(
                      LazyLinking->LazyObjLinkingLayer)
                : static_cast<orc::ObjectLayer &>(ObjLayer);
  }

  Expected<FileInfo &> findFileInfo(StringRef FileName);
  Expected<MemoryRegionInfo &> findSectionInfo(StringRef FileName,
                                               StringRef SectionName);
  Expected<MemoryRegionInfo &> findStubInfo(StringRef FileName,
                                            StringRef TargetName,
                                            StringRef KindNameFilter);
  Expected<MemoryRegionInfo &> findGOTEntryInfo(StringRef FileName,
                                                StringRef TargetName);

  bool isSymbolRegistered(const orc::SymbolStringPtr &Name);
  Expected<MemoryRegionInfo &> findSymbolInfo(const orc::SymbolStringPtr &Name,
                                              Twine ErrorMsgStem);

  DynLibJDMap DynLibJDs;

  SymbolInfoMap SymbolInfos;
  FileInfoMap FileInfos;

  StringSet<> HarnessFiles;
  StringSet<> HarnessExternals;
  StringSet<> HarnessDefinitions;
  DenseMap<StringRef, StringRef> CanonicalWeakDefs;

  std::optional<Regex> ShowGraphsRegex;

private:
  Session(std::unique_ptr<orc::ExecutorProcessControl> EPC, Error &Err);
};

/// Record symbols, GOT entries, stubs, and sections for ELF file.
Error registerELFGraphInfo(Session &S, jitlink::LinkGraph &G);

/// Record symbols, GOT entries, stubs, and sections for MachO file.
Error registerMachOGraphInfo(Session &S, jitlink::LinkGraph &G);

/// Record symbols, GOT entries, stubs, and sections for COFF file.
Error registerCOFFGraphInfo(Session &S, jitlink::LinkGraph &G);

/// Adds a statistics gathering plugin if any stats options are used.
void enableStatistics(Session &S, bool UsingOrcRuntime);

} // end namespace llvm

#endif // LLVM_TOOLS_LLVM_JITLINK_LLVM_JITLINK_H