MCJIT: Add faux remote target execution to lli for the MCJIT.

Simulate a remote target address space by allocating a seperate chunk of
memory for the target and re-mapping section addresses to that prior to
execution. Later we'll want to have a truly remote process, but for now
this gets us closer to being able to test the remote target
functionality outside LLDB.

rdar://12157052

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163216 91177308-0d34-0410-b5e6-96231b3b80d8

tools/lli/RemoteTarget.cpp

@@ -0,0 +1,61 @@
+//===- RemoteTarget.cpp - LLVM Remote process JIT execution --------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Implementation of the RemoteTarget class which executes JITed code in a
+// separate address range from where it was built.
+//
+//===----------------------------------------------------------------------===//
+
+#include "RemoteTarget.h"
+#include <llvm/ADT/StringRef.h>
+#include <llvm/Support/Memory.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string>
+using namespace llvm;
+
+bool RemoteTarget::allocateSpace(size_t Size, unsigned Alignment,
+                                 uint64_t &Address) {
+  sys::MemoryBlock *Prev = Allocations.size() ? &Allocations.back() : NULL;
+  sys::MemoryBlock Mem = sys::Memory::AllocateRWX(Size, Prev, &ErrorMsg);
+  if (Mem.base() == NULL)
+    return true;
+  if ((uintptr_t)Mem.base() % Alignment) {
+    ErrorMsg = "unable to allocate sufficiently aligned memory";
+    return true;
+  }
+  Address = reinterpret_cast<uint64_t>(Mem.base());
+  return false;
+}
+
+bool RemoteTarget::loadData(uint64_t Address, const void *Data, size_t Size) {
+  memcpy ((void*)Address, Data, Size);
+  sys::MemoryBlock Mem((void*)Address, Size);
+  sys::Memory::setExecutable(Mem, &ErrorMsg);
+  return false;
+}
+
+bool RemoteTarget::loadCode(uint64_t Address, const void *Data, size_t Size) {
+  memcpy ((void*)Address, Data, Size);
+  return false;
+}
+
+bool RemoteTarget::executeCode(uint64_t Address, int &RetVal) {
+  int (*fn)(void) = (int(*)(void))Address;
+  RetVal = fn();
+  return false;
+}
+
+void RemoteTarget::create() {
+}
+
+void RemoteTarget::stop() {
+  for (unsigned i = 0, e = Allocations.size(); i != e; ++i)
+    sys::Memory::ReleaseRWX(Allocations[i]);
+}