Add a test for the dependency on host-only types from alpaka libraries

HeterogeneousCore/AlpakaTest/BuildFile.xml

@@ -1,6 +1,14 @@
 <use name="FWCore/Framework"/>
 <use name="HeterogeneousCore/AlpakaCore"/>
 <use name="HeterogeneousCore/AlpakaInterface"/>
+<!--
+Let the alpaka libraries depend on the main library.
+The possible syntaxes are:
+  <use name="HeterogeneousCore/AlpakaTest" for="alpaka"/>
+  <use name="1" for="alpaka"/>
+  <flags USE_ALPAKA="1"/>
+-->
+<use name="HeterogeneousCore/AlpakaTest" for="alpaka"/>
 <flags ALPAKA_BACKENDS="1"/>
 <export>
   <lib name="1"/>

HeterogeneousCore/AlpakaTest/interface/HostOnlyType.h

@@ -0,0 +1,21 @@
+#ifndef HeterogeneousCore_AlpakaTest_interface_HostOnlyType_h
+#define HeterogeneousCore_AlpakaTest_interface_HostOnlyType_h
+
+namespace alpakatest {
+
+  /* A simple class to demonstarte the dependency on host-only types from alpaka libraries */
+  class HostOnlyType {
+  public:
+    HostOnlyType() : value_{0} {}
+    HostOnlyType(int value) : value_{value} {}
+    void set(int value) { value_ = value; }
+    int get() { return value_; }
+    void print();
+
+  private:
+    int value_;
+  };
+
+}  // namespace alpakatest
+
+#endif  // HeterogeneousCore_AlpakaTest_interface_HostOnlyType_h

HeterogeneousCore/AlpakaTest/interface/alpaka/printAnswer.h

@@ -0,0 +1,12 @@
+#ifndef HeterogeneousCore_AlpakaTest_interface_alpaka_printAnswer_h
+#define HeterogeneousCore_AlpakaTest_interface_alpaka_printAnswer_h
+
+#include "HeterogeneousCore/AlpakaInterface/interface/config.h"
+
+namespace ALPAKA_ACCELERATOR_NAMESPACE::alpakatest {
+
+  void printAnswer();
+
+}  // namespace ALPAKA_ACCELERATOR_NAMESPACE::alpakatest
+
+#endif  // HeterogeneousCore_AlpakaTest_interface_alpaka_printAnswer_h

HeterogeneousCore/AlpakaTest/src/HostOnlyType.cc

@@ -0,0 +1,9 @@
+#include <iostream>
+
+#include "HeterogeneousCore/AlpakaTest/interface/HostOnlyType.h"
+
+namespace alpakatest {
+
+  void HostOnlyType::print() { std::cout << "The HostOnlyType value is " << value_ << '\n'; }
+
+}  // namespace alpakatest

HeterogeneousCore/AlpakaTest/src/alpaka/printAnswer.cc

@@ -0,0 +1,14 @@
+#include "HeterogeneousCore/AlpakaInterface/interface/config.h"
+#include "HeterogeneousCore/AlpakaTest/interface/HostOnlyType.h"
+#include "HeterogeneousCore/AlpakaTest/interface/alpaka/printAnswer.h"
+
+namespace ALPAKA_ACCELERATOR_NAMESPACE::alpakatest {
+  using namespace ::alpakatest;
+
+  // A simple function to demonstarte the dependency on host-only types from alpaka libraries
+  void printAnswer() {
+    HostOnlyType answer(42);
+    answer.print();
+  }
+
+}  // namespace ALPAKA_ACCELERATOR_NAMESPACE::alpakatest

HeterogeneousCore/AlpakaTest/test/BuildFile.xml

@@ -13,3 +13,9 @@
   <!-- dependence only to trigger the unit test when AMD GPU is (expected to be) present -->
   <use name="rocm"/>
 </test>
+
+<bin name="alpakaTestPrintAnswer" file="alpaka/printAnswer.cpp">
+  <use name="HeterogeneousCore/AlpakaInterface"/>
+  <use name='HeterogeneousCore/AlpakaTest'/>
+  <flags ALPAKA_BACKENDS="1"/>
+</bin>

HeterogeneousCore/AlpakaTest/test/alpaka/printAnswer.cpp

@@ -0,0 +1,8 @@
+#include "HeterogeneousCore/AlpakaInterface/interface/config.h"
+#include "HeterogeneousCore/AlpakaTest/interface/alpaka/printAnswer.h"
+
+// each test binary is built for a single Alpaka backend
+using namespace ALPAKA_ACCELERATOR_NAMESPACE;
+using namespace ALPAKA_ACCELERATOR_NAMESPACE::alpakatest;
+
+int main() { printAnswer(); }