include/llvm/ExecutionEngine/Orc/JITSymbol.h

   1 //===----------- JITSymbol.h - JIT symbol abstraction -----------*- C++ -*-===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // Abstraction for target process addresses.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #ifndef LLVM_EXECUTIONENGINE_ORC_JITSYMBOL_H
  15 #define LLVM_EXECUTIONENGINE_ORC_JITSYMBOL_H
  16
  17 #include <functional>
  18
  19 namespace llvm {
  20
  21 /// @brief Represents an address in the target process's address space.
  22 typedef uint64_t TargetAddress;
  23
  24 /// @brief Represents a symbol in the JIT.
  25 class JITSymbol {
  26 public:
  27   typedef std::function<TargetAddress()> GetAddressFtor;
  28
  29   JITSymbol(std::nullptr_t) : CachedAddr(0) {}
  30
  31   JITSymbol(GetAddressFtor GetAddress)
  32       : CachedAddr(0), GetAddress(std::move(GetAddress)) {}
  33
  34   /// @brief Returns true if the symbol exists, false otherwise.
  35   explicit operator bool() const { return CachedAddr || GetAddress; }
  36
  37   /// @brief Get the address of the symbol in the target address space. Returns
  38   ///        '0' if the symbol does not exist.
  39   TargetAddress getAddress() {
  40     if (GetAddress) {
  41       CachedAddr = GetAddress();
  42       assert(CachedAddr && "Symbol could not be materialized.");
  43       GetAddress = nullptr;
  44     }
  45     return CachedAddr;
  46   }
  47
  48 private:
  49   TargetAddress CachedAddr;
  50   GetAddressFtor GetAddress;
  51 };
  52
  53 }
  54
  55 #endif // LLVM_EXECUTIONENGINE_ORC_JITSYMBOL_H