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Diffstat (limited to 'include/llvm/ExecutionEngine/Orc/JITSymbol.h')
-rw-r--r-- | include/llvm/ExecutionEngine/Orc/JITSymbol.h | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/include/llvm/ExecutionEngine/Orc/JITSymbol.h b/include/llvm/ExecutionEngine/Orc/JITSymbol.h new file mode 100644 index 0000000..a670222 --- /dev/null +++ b/include/llvm/ExecutionEngine/Orc/JITSymbol.h @@ -0,0 +1,74 @@ +//===----------- JITSymbol.h - JIT symbol abstraction -----------*- C++ -*-===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// Abstraction for target process addresses. +// +//===----------------------------------------------------------------------===// + +#ifndef LLVM_EXECUTIONENGINE_ORC_JITSYMBOL_H +#define LLVM_EXECUTIONENGINE_ORC_JITSYMBOL_H + +#include "llvm/Support/DataTypes.h" +#include <cassert> +#include <functional> + +namespace llvm { +namespace orc { + +/// @brief Represents an address in the target process's address space. +typedef uint64_t TargetAddress; + +/// @brief Represents a symbol in the JIT. +class JITSymbol { +public: + typedef std::function<TargetAddress()> GetAddressFtor; + + /// @brief Create a 'null' symbol that represents failure to find a symbol + /// definition. + JITSymbol(std::nullptr_t) : CachedAddr(0) {} + + /// @brief Create a symbol for a definition with a known address. + JITSymbol(TargetAddress Addr) + : CachedAddr(Addr) {} + + /// @brief Create a symbol for a definition that doesn't have a known address + /// yet. + /// @param GetAddress A functor to materialize a definition (fixing the + /// address) on demand. + /// + /// This constructor allows a JIT layer to provide a reference to a symbol + /// definition without actually materializing the definition up front. The + /// user can materialize the definition at any time by calling the getAddress + /// method. + JITSymbol(GetAddressFtor GetAddress) + : CachedAddr(0), GetAddress(std::move(GetAddress)) {} + + /// @brief Returns true if the symbol exists, false otherwise. + explicit operator bool() const { return CachedAddr || GetAddress; } + + /// @brief Get the address of the symbol in the target address space. Returns + /// '0' if the symbol does not exist. + TargetAddress getAddress() { + if (GetAddress) { + CachedAddr = GetAddress(); + assert(CachedAddr && "Symbol could not be materialized."); + GetAddress = nullptr; + } + return CachedAddr; + } + +private: + TargetAddress CachedAddr; + GetAddressFtor GetAddress; +}; + +} // End namespace orc. +} // End namespace llvm. + +#endif // LLVM_EXECUTIONENGINE_ORC_JITSYMBOL_H |