include/llvm/ExecutionEngine/Orc/GlobalMappingLayer.h

   1 //===- GlobalMappingLayer.h - Run all IR through a functor ------*- 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 // Convenience layer for injecting symbols that will appear in calls to
  10 // findSymbol.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #ifndef LLVM_EXECUTIONENGINE_ORC_GLOBALMAPPINGLAYER_H
  15 #define LLVM_EXECUTIONENGINE_ORC_GLOBALMAPPINGLAYER_H
  16
  17 #include "llvm/ExecutionEngine/JITSymbol.h"
  18 #include <map>
  19 #include <memory>
  20 #include <string>
  21
  22 namespace llvm {
  23
  24 class Module;
  25 class JITSymbolResolver;
  26
  27 namespace orc {
  28
  29 /// Global mapping layer.
  30 ///
  31 ///   This layer overrides the findSymbol method to first search a local symbol
  32 /// table that the client can define. It can be used to inject new symbol
  33 /// mappings into the JIT. Beware, however: symbols within a single IR module or
  34 /// object file will still resolve locally (via RuntimeDyld's symbol table) -
  35 /// such internal references cannot be overriden via this layer.
  36 template <typename BaseLayerT>
  37 class GlobalMappingLayer {
  38 public:
  39
  40   /// Handle to an added module.
  41   using ModuleHandleT = typename BaseLayerT::ModuleHandleT;
  42
  43   /// Construct an GlobalMappingLayer with the given BaseLayer
  44   GlobalMappingLayer(BaseLayerT &BaseLayer) : BaseLayer(BaseLayer) {}
  45
  46   /// Add the given module to the JIT.
  47   /// @return A handle for the added modules.
  48   Expected<ModuleHandleT>
  49   addModule(std::shared_ptr<Module> M,
  50             std::shared_ptr<JITSymbolResolver> Resolver) {
  51     return BaseLayer.addModule(std::move(M), std::move(Resolver));
  52   }
  53
  54   /// Remove the module set associated with the handle H.
  55   Error removeModule(ModuleHandleT H) { return BaseLayer.removeModule(H); }
  56
  57   /// Manually set the address to return for the given symbol.
  58   void setGlobalMapping(const std::string &Name, JITTargetAddress Addr) {
  59     SymbolTable[Name] = Addr;
  60   }
  61
  62   /// Remove the given symbol from the global mapping.
  63   void eraseGlobalMapping(const std::string &Name) {
  64     SymbolTable.erase(Name);
  65   }
  66
  67   /// Search for the given named symbol.
  68   ///
  69   ///          This method will first search the local symbol table, returning
  70   ///        any symbol found there. If the symbol is not found in the local
  71   ///        table then this call will be passed through to the base layer.
  72   ///
  73   /// @param Name The name of the symbol to search for.
  74   /// @param ExportedSymbolsOnly If true, search only for exported symbols.
  75   /// @return A handle for the given named symbol, if it exists.
  76   JITSymbol findSymbol(const std::string &Name, bool ExportedSymbolsOnly) {
  77     auto I = SymbolTable.find(Name);
  78     if (I != SymbolTable.end())
  79       return JITSymbol(I->second, JITSymbolFlags::Exported);
  80     return BaseLayer.findSymbol(Name, ExportedSymbolsOnly);
  81   }
  82
  83   /// Get the address of the given symbol in the context of the of the
  84   ///        module represented by the handle H. This call is forwarded to the
  85   ///        base layer's implementation.
  86   /// @param H The handle for the module to search in.
  87   /// @param Name The name of the symbol to search for.
  88   /// @param ExportedSymbolsOnly If true, search only for exported symbols.
  89   /// @return A handle for the given named symbol, if it is found in the
  90   ///         given module.
  91   JITSymbol findSymbolIn(ModuleHandleT H, const std::string &Name,
  92                          bool ExportedSymbolsOnly) {
  93     return BaseLayer.findSymbolIn(H, Name, ExportedSymbolsOnly);
  94   }
  95
  96   /// Immediately emit and finalize the module set represented by the
  97   ///        given handle.
  98   /// @param H Handle for module set to emit/finalize.
  99   Error emitAndFinalize(ModuleHandleT H) {
 100     return BaseLayer.emitAndFinalize(H);
 101   }
 102
 103 private:
 104   BaseLayerT &BaseLayer;
 105   std::map<std::string, JITTargetAddress> SymbolTable;
 106 };
 107
 108 } // end namespace orc
 109 } // end namespace llvm
 110
 111 #endif // LLVM_EXECUTIONENGINE_ORC_GLOBALMAPPINGLAYER_H