[Kaleidoscope][BuildingAJIT] Add code for Chapter 5 - remote JITing.

This chapter demonstrates lazily JITing from ASTs with the expressions being
executed on a remote machine via a TCP connection. It needs some polish, but is
substantially complete.

Currently x86-64 SysV ABI (Darwin and Linux) only, but other architectures
can be supported by changing the server code to use alternative ABI support
classes from llvm/include/llvm/ExecutionEngine/Orc/OrcABISupport.h.

llvm-svn: 271193

1 files changed, 74 insertions, 0 deletions

diff --git a/llvm/examples/Kaleidoscope/BuildingAJIT/Chapter5/RemoteJITUtils.h b/llvm/examples/Kaleidoscope/BuildingAJIT/Chapter5/RemoteJITUtils.h
new file mode 100644
index 00000000000..869d0a7ef39
--- /dev/null
+++ b/llvm/examples/Kaleidoscope/BuildingAJIT/Chapter5/RemoteJITUtils.h
@@ -0,0 +1,74 @@
+//===-- RemoteJITUtils.h - Utilities for remote-JITing with LLI -*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Utilities for remote-JITing with LLI.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_TOOLS_LLI_REMOTEJITUTILS_H
+#define LLVM_TOOLS_LLI_REMOTEJITUTILS_H
+
+#include "llvm/ExecutionEngine/Orc/RPCChannel.h"
+#include "llvm/ExecutionEngine/RTDyldMemoryManager.h"
+#include <mutex>
+
+#if !defined(_MSC_VER) && !defined(__MINGW32__)
+#include <unistd.h>
+#else
+#include <io.h>
+#endif
+
+/// RPC channel that reads from and writes from file descriptors.
+class FDRPCChannel final : public llvm::orc::remote::RPCChannel {
+public:
+  FDRPCChannel(int InFD, int OutFD) : InFD(InFD), OutFD(OutFD) {}
+
+  llvm::Error readBytes(char *Dst, unsigned Size) override {
+    assert(Dst && "Attempt to read into null.");
+    ssize_t Completed = 0;
+    while (Completed < static_cast<ssize_t>(Size)) {
+      ssize_t Read = ::read(InFD, Dst + Completed, Size - Completed);
+      if (Read <= 0) {
+        auto ErrNo = errno;
+        if (ErrNo == EAGAIN || ErrNo == EINTR)
+          continue;
+        else
+          return llvm::errorCodeToError(
+                   std::error_code(errno, std::generic_category()));
+      }
+      Completed += Read;
+    }
+    return llvm::Error::success();
+  }
+
+  llvm::Error appendBytes(const char *Src, unsigned Size) override {
+    assert(Src && "Attempt to append from null.");
+    ssize_t Completed = 0;
+    while (Completed < static_cast<ssize_t>(Size)) {
+      ssize_t Written = ::write(OutFD, Src + Completed, Size - Completed);
+      if (Written < 0) {
+        auto ErrNo = errno;
+        if (ErrNo == EAGAIN || ErrNo == EINTR)
+          continue;
+        else
+          return llvm::errorCodeToError(
+                   std::error_code(errno, std::generic_category()));
+      }
+      Completed += Written;
+    }
+    return llvm::Error::success();
+  }
+
+  llvm::Error send() override { return llvm::Error::success(); }
+
+private:
+  int InFD, OutFD;
+};
+
+#endif