[Orc] Add a JITSymbol class to the Orc APIs, refactor APIs, update clients.

[oota-llvm.git] / include / llvm / ExecutionEngine / Orc / JITSymbol.h

diff --git a/include/llvm/ExecutionEngine/Orc/JITSymbol.h b/include/llvm/ExecutionEngine/Orc/JITSymbol.h
new file mode 100644 (file)
index 0000000..c55e43c
--- /dev/null
+++ b/include/llvm/ExecutionEngine/Orc/JITSymbol.h
@@ -0,0 +1,55 @@
+//===----------- 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 <functional>
+
+namespace llvm {
+
+/// @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;
+
+  JITSymbol(std::nullptr_t) : CachedAddr(0) {}
+
+  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;
+};
+
+}
+
+#endif // LLVM_EXECUTIONENGINE_ORC_JITSYMBOL_H