reference, declarationdefinition
definition → references, declarations, derived classes, virtual overrides
reference to multiple definitions → definitions
unreferenced
    1
    2
    3
    4
    5
    6
    7
    8
    9
   10
   11
   12
   13
   14
   15
   16
   17
   18
   19
   20
   21
   22
   23
   24
   25
   26
   27
   28
   29
   30
   31
   32
   33
   34
   35
   36
   37
   38
   39
   40
   41
   42
   43
   44
   45
   46
   47
   48
   49
   50
   51
   52
   53
   54
   55
   56
   57
   58
   59
   60
   61
   62
   63
   64
   65
   66
   67
   68
   69
   70
   71
   72
   73
   74
   75
   76
   77
   78
   79
   80
   81
   82
   83
   84
   85
   86
   87
   88
   89
   90
   91
   92
   93
   94
   95
   96
   97
   98
   99
  100
  101
  102
  103
  104
  105
  106
  107
  108
  109
  110
  111
  112
  113
  114
  115
  116
  117
  118
  119
  120
  121
  122
  123
  124
  125
  126
  127
  128
  129
  130
  131
  132
  133
  134
  135
  136
  137
  138
  139
  140
  141
  142
  143
  144
  145
  146
  147
  148
  149
  150
  151
  152
  153
  154
  155
  156
  157
  158
  159
  160
  161
  162
  163
  164
  165
  166
//===---------------- Layer.h -- Layer interfaces --------------*- 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
//
//===----------------------------------------------------------------------===//
//
// Layer interfaces.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_EXECUTIONENGINE_ORC_LAYER_H
#define LLVM_EXECUTIONENGINE_ORC_LAYER_H

#include "llvm/ExecutionEngine/Orc/Core.h"
#include "llvm/ExecutionEngine/Orc/ThreadSafeModule.h"
#include "llvm/IR/Module.h"
#include "llvm/Support/MemoryBuffer.h"

namespace llvm {
namespace orc {

/// Interface for layers that accept LLVM IR.
class IRLayer {
public:
  IRLayer(ExecutionSession &ES);
  virtual ~IRLayer();

  /// Returns the ExecutionSession for this layer.
  ExecutionSession &getExecutionSession() { return ES; }

  /// Sets the CloneToNewContextOnEmit flag (false by default).
  ///
  /// When set, IR modules added to this layer will be cloned on to a new
  /// context before emit is called. This can be used by clients who want
  /// to load all IR using one LLVMContext (to save memory via type and
  /// constant uniquing), but want to move Modules to fresh contexts before
  /// compiling them to enable concurrent compilation.
  /// Single threaded clients, or clients who load every module on a new
  /// context, need not set this.
  void setCloneToNewContextOnEmit(bool CloneToNewContextOnEmit) {
    this->CloneToNewContextOnEmit = CloneToNewContextOnEmit;
  }

  /// Returns the current value of the CloneToNewContextOnEmit flag.
  bool getCloneToNewContextOnEmit() const { return CloneToNewContextOnEmit; }

  /// Adds a MaterializationUnit representing the given IR to the given
  /// JITDylib.
  virtual Error add(JITDylib &JD, ThreadSafeModule TSM,
                    VModuleKey K = VModuleKey());

  /// Emit should materialize the given IR.
  virtual void emit(MaterializationResponsibility R, ThreadSafeModule TSM) = 0;

private:
  bool CloneToNewContextOnEmit = false;
  ExecutionSession &ES;
};

/// IRMaterializationUnit is a convenient base class for MaterializationUnits
/// wrapping LLVM IR. Represents materialization responsibility for all symbols
/// in the given module. If symbols are overridden by other definitions, then
/// their linkage is changed to available-externally.
class IRMaterializationUnit : public MaterializationUnit {
public:
  using SymbolNameToDefinitionMap = std::map<SymbolStringPtr, GlobalValue *>;

  /// Create an IRMaterializationLayer. Scans the module to build the
  /// SymbolFlags and SymbolToDefinition maps.
  IRMaterializationUnit(ExecutionSession &ES, ThreadSafeModule TSM,
                        VModuleKey K);

  /// Create an IRMaterializationLayer from a module, and pre-existing
  /// SymbolFlags and SymbolToDefinition maps. The maps must provide
  /// entries for each definition in M.
  /// This constructor is useful for delegating work from one
  /// IRMaterializationUnit to another.
  IRMaterializationUnit(ThreadSafeModule TSM, VModuleKey K,
                        SymbolFlagsMap SymbolFlags,
                        SymbolNameToDefinitionMap SymbolToDefinition);

  /// Return the ModuleIdentifier as the name for this MaterializationUnit.
  StringRef getName() const override;

  const ThreadSafeModule &getModule() const { return TSM; }

protected:
  ThreadSafeModule TSM;
  SymbolNameToDefinitionMap SymbolToDefinition;

private:
  void discard(const JITDylib &JD, const SymbolStringPtr &Name) override;
};

/// MaterializationUnit that materializes modules by calling the 'emit' method
/// on the given IRLayer.
class BasicIRLayerMaterializationUnit : public IRMaterializationUnit {
public:
  BasicIRLayerMaterializationUnit(IRLayer &L, VModuleKey K,
                                  ThreadSafeModule TSM);

private:

  void materialize(MaterializationResponsibility R) override;

  IRLayer &L;
  VModuleKey K;
};

/// Interface for Layers that accept object files.
class ObjectLayer {
public:
  ObjectLayer(ExecutionSession &ES);
  virtual ~ObjectLayer();

  /// Returns the execution session for this layer.
  ExecutionSession &getExecutionSession() { return ES; }

  /// Adds a MaterializationUnit representing the given IR to the given
  /// JITDylib.
  virtual Error add(JITDylib &JD, std::unique_ptr<MemoryBuffer> O,
                    VModuleKey K = VModuleKey());

  /// Emit should materialize the given IR.
  virtual void emit(MaterializationResponsibility R,
                    std::unique_ptr<MemoryBuffer> O) = 0;

private:
  ExecutionSession &ES;
};

/// Materializes the given object file (represented by a MemoryBuffer
/// instance) by calling 'emit' on the given ObjectLayer.
class BasicObjectLayerMaterializationUnit : public MaterializationUnit {
public:
  static Expected<std::unique_ptr<BasicObjectLayerMaterializationUnit>>
  Create(ObjectLayer &L, VModuleKey K, std::unique_ptr<MemoryBuffer> O);

  BasicObjectLayerMaterializationUnit(ObjectLayer &L, VModuleKey K,
                                      std::unique_ptr<MemoryBuffer> O,
                                      SymbolFlagsMap SymbolFlags);

  /// Return the buffer's identifier as the name for this MaterializationUnit.
  StringRef getName() const override;

private:

  void materialize(MaterializationResponsibility R) override;
  void discard(const JITDylib &JD, const SymbolStringPtr &Name) override;

  ObjectLayer &L;
  std::unique_ptr<MemoryBuffer> O;
};

/// Returns a SymbolFlagsMap for the object file represented by the given
/// buffer, or an error if the buffer does not contain a valid object file.
// FIXME: Maybe move to Core.h?
Expected<SymbolFlagsMap> getObjectSymbolFlags(ExecutionSession &ES,
                                              MemoryBufferRef ObjBuffer);

} // End namespace orc
} // End namespace llvm

#endif // LLVM_EXECUTIONENGINE_ORC_LAYER_H