[orc-rt] Hoist DirectCaller test utility into header to enable re-use. (#162405)

The DirectCaller utility allows "direct" calls (with arguments
serialized into, and then immediately back out of a
WrapperFunctionBuffer) to wrapper functions. It was introduced for the
SPSWrapperFunction tests, but will be useful for testing WrapperFunction
interfaces for various orc-rt APIs too, so this commit hoists it
somewhere where it can be reused.

orc-rt/unittests/DirectCaller.h

@@ -0,0 +1,71 @@
+//===- DirectCaller.h -----------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef ORC_RT_UNITTEST_DIRECTCALLER_H
+#define ORC_RT_UNITTEST_DIRECTCALLER_H
+
+#include "orc-rt/WrapperFunction.h"
+
+#include <memory>
+#include <utility>
+
+/// Make calls and call result handlers directly on the current thread.
+class DirectCaller {
+private:
+  class DirectResultSender {
+  public:
+    virtual ~DirectResultSender() {}
+    virtual void send(orc_rt_SessionRef Session,
+                      orc_rt::WrapperFunctionBuffer ResultBytes) = 0;
+    static void send(orc_rt_SessionRef Session, void *CallCtx,
+                     orc_rt_WrapperFunctionBuffer ResultBytes) {
+      std::unique_ptr<DirectResultSender>(
+          reinterpret_cast<DirectResultSender *>(CallCtx))
+          ->send(Session, ResultBytes);
+    }
+  };
+
+  template <typename ImplFn>
+  class DirectResultSenderImpl : public DirectResultSender {
+  public:
+    DirectResultSenderImpl(ImplFn &&Fn) : Fn(std::forward<ImplFn>(Fn)) {}
+    void send(orc_rt_SessionRef Session,
+              orc_rt::WrapperFunctionBuffer ResultBytes) override {
+      Fn(Session, std::move(ResultBytes));
+    }
+
+  private:
+    std::decay_t<ImplFn> Fn;
+  };
+
+  template <typename ImplFn>
+  static std::unique_ptr<DirectResultSender>
+  makeDirectResultSender(ImplFn &&Fn) {
+    return std::make_unique<DirectResultSenderImpl<ImplFn>>(
+        std::forward<ImplFn>(Fn));
+  }
+
+public:
+  DirectCaller(orc_rt_SessionRef Session, orc_rt_WrapperFunction Fn)
+      : Session(Session), Fn(Fn) {}
+
+  template <typename HandleResultFn>
+  void operator()(HandleResultFn &&HandleResult,
+                  orc_rt::WrapperFunctionBuffer ArgBytes) {
+    auto DR =
+        makeDirectResultSender(std::forward<HandleResultFn>(HandleResult));
+    Fn(Session, reinterpret_cast<void *>(DR.release()),
+       DirectResultSender::send, ArgBytes.release());
+  }
+
+private:
+  orc_rt_SessionRef Session;
+  orc_rt_WrapperFunction Fn;
+};
+
+#endif // ORC_RT_UNITTEST_DIRECTCALLER_H

orc-rt/unittests/SPSWrapperFunctionTest.cpp

@@ -16,64 +16,12 @@
 #include "orc-rt/WrapperFunction.h"
 #include "orc-rt/move_only_function.h"
 
+#include "DirectCaller.h"
+
 #include "gtest/gtest.h"
 
 using namespace orc_rt;
 
-/// Make calls and call result handlers directly on the current thread.
-class DirectCaller {
-private:
-  class DirectResultSender {
-  public:
-    virtual ~DirectResultSender() {}
-    virtual void send(orc_rt_SessionRef Session,
-                      WrapperFunctionBuffer ResultBytes) = 0;
-    static void send(orc_rt_SessionRef Session, void *CallCtx,
-                     orc_rt_WrapperFunctionBuffer ResultBytes) {
-      std::unique_ptr<DirectResultSender>(
-          reinterpret_cast<DirectResultSender *>(CallCtx))
-          ->send(Session, ResultBytes);
-    }
-  };
-
-  template <typename ImplFn>
-  class DirectResultSenderImpl : public DirectResultSender {
-  public:
-    DirectResultSenderImpl(ImplFn &&Fn) : Fn(std::forward<ImplFn>(Fn)) {}
-    void send(orc_rt_SessionRef Session,
-              WrapperFunctionBuffer ResultBytes) override {
-      Fn(Session, std::move(ResultBytes));
-    }
-
-  private:
-    std::decay_t<ImplFn> Fn;
-  };
-
-  template <typename ImplFn>
-  static std::unique_ptr<DirectResultSender>
-  makeDirectResultSender(ImplFn &&Fn) {
-    return std::make_unique<DirectResultSenderImpl<ImplFn>>(
-        std::forward<ImplFn>(Fn));
-  }
-
-public:
-  DirectCaller(orc_rt_SessionRef Session, orc_rt_WrapperFunction Fn)
-      : Session(Session), Fn(Fn) {}
-
-  template <typename HandleResultFn>
-  void operator()(HandleResultFn &&HandleResult,
-                  WrapperFunctionBuffer ArgBytes) {
-    auto DR =
-        makeDirectResultSender(std::forward<HandleResultFn>(HandleResult));
-    Fn(Session, reinterpret_cast<void *>(DR.release()),
-       DirectResultSender::send, ArgBytes.release());
-  }
-
-private:
-  orc_rt_SessionRef Session;
-  orc_rt_WrapperFunction Fn;
-};
-
 static void void_noop_sps_wrapper(orc_rt_SessionRef Session, void *CallCtx,
                                   orc_rt_WrapperFunctionReturn Return,
                                   orc_rt_WrapperFunctionBuffer ArgBytes) {