[SYCL] Allow overriding plugin libraries

sycl/source/detail/config.def

@@ -31,3 +31,7 @@ CONFIG(SYCL_CACHE_THRESHOLD, 16, __SYCL_CACHE_THRESHOLD)
 CONFIG(SYCL_CACHE_MIN_DEVICE_IMAGE_SIZE, 16, __SYCL_CACHE_MIN_DEVICE_IMAGE_SIZE)
 CONFIG(SYCL_CACHE_MAX_DEVICE_IMAGE_SIZE, 16, __SYCL_CACHE_MAX_DEVICE_IMAGE_SIZE)
 CONFIG(INTEL_ENABLE_OFFLOAD_ANNOTATIONS, 1, __SYCL_INTEL_ENABLE_OFFLOAD_ANNOTATIONS)
+CONFIG(SYCL_OVERRIDE_PI_OPENCL, 1024, __SYCL_OVERRIDE_PI_OPENCL)
+CONFIG(SYCL_OVERRIDE_PI_LEVEL_ZERO, 1024, __SYCL_OVERRIDE_PI_LEVEL_ZERO)
+CONFIG(SYCL_OVERRIDE_PI_CUDA, 1024, __SYCL_OVERRIDE_PI_CUDA)
+CONFIG(SYCL_OVERRIDE_PI_ROCM, 1024, __SYCL_OVERRIDE_PI_ROCM)

sycl/source/detail/pi.cpp

@@ -225,19 +225,34 @@ std::string memFlagsToString(pi_mem_flags Flags) {
 std::shared_ptr<plugin> GlobalPlugin;
 
 // Find the plugin at the appropriate location and return the location.
-bool findPlugins(std::vector<std::pair<std::string, backend>> &PluginNames) {
+std::vector<std::pair<std::string, backend>> findPlugins() {
+  std::vector<std::pair<std::string, backend>> PluginNames;
+
   // TODO: Based on final design discussions, change the location where the
   // plugin must be searched; how to identify the plugins etc. Currently the
   // search is done for libpi_opencl.so/pi_opencl.dll file in LD_LIBRARY_PATH
   // env only.
   //
+  const char *OpenCLPluginName =
+      SYCLConfig<SYCL_OVERRIDE_PI_OPENCL>::get()
+          ? SYCLConfig<SYCL_OVERRIDE_PI_OPENCL>::get()
+          : __SYCL_OPENCL_PLUGIN_NAME;
+  const char *L0PluginName =
+      SYCLConfig<SYCL_OVERRIDE_PI_LEVEL_ZERO>::get()
+          ? SYCLConfig<SYCL_OVERRIDE_PI_LEVEL_ZERO>::get()
+          : __SYCL_LEVEL_ZERO_PLUGIN_NAME;
+  const char *CUDAPluginName = SYCLConfig<SYCL_OVERRIDE_PI_CUDA>::get()
+                                   ? SYCLConfig<SYCL_OVERRIDE_PI_CUDA>::get()
+                                   : __SYCL_CUDA_PLUGIN_NAME;
+  const char *ROCMPluginName = SYCLConfig<SYCL_OVERRIDE_PI_ROCM>::get()
+                                   ? SYCLConfig<SYCL_OVERRIDE_PI_ROCM>::get()
+                                   : __SYCL_ROCM_PLUGIN_NAME;
   device_filter_list *FilterList = SYCLConfig<SYCL_DEVICE_FILTER>::get();
   if (!FilterList) {
-    PluginNames.emplace_back(__SYCL_OPENCL_PLUGIN_NAME, backend::opencl);
-    PluginNames.emplace_back(__SYCL_LEVEL_ZERO_PLUGIN_NAME,
-                             backend::level_zero);
-    PluginNames.emplace_back(__SYCL_CUDA_PLUGIN_NAME, backend::cuda);
-    PluginNames.emplace_back(__SYCL_ROCM_PLUGIN_NAME, backend::rocm);
+    PluginNames.emplace_back(OpenCLPluginName, backend::opencl);
+    PluginNames.emplace_back(L0PluginName, backend::level_zero);
+    PluginNames.emplace_back(CUDAPluginName, backend::cuda);
+    PluginNames.emplace_back(ROCMPluginName, backend::rocm);
   } else {
     std::vector<device_filter> Filters = FilterList->get();
     bool OpenCLFound = false;
@@ -248,26 +263,25 @@ bool findPlugins(std::vector<std::pair<std::string, backend>> &PluginNames) {
       backend Backend = Filter.Backend;
       if (!OpenCLFound &&
           (Backend == backend::opencl || Backend == backend::all)) {
-        PluginNames.emplace_back(__SYCL_OPENCL_PLUGIN_NAME, backend::opencl);
+        PluginNames.emplace_back(OpenCLPluginName, backend::opencl);
         OpenCLFound = true;
       }
       if (!LevelZeroFound &&
           (Backend == backend::level_zero || Backend == backend::all)) {
-        PluginNames.emplace_back(__SYCL_LEVEL_ZERO_PLUGIN_NAME,
-                                 backend::level_zero);
+        PluginNames.emplace_back(L0PluginName, backend::level_zero);
         LevelZeroFound = true;
       }
       if (!CudaFound && (Backend == backend::cuda || Backend == backend::all)) {
-        PluginNames.emplace_back(__SYCL_CUDA_PLUGIN_NAME, backend::cuda);
+        PluginNames.emplace_back(CUDAPluginName, backend::cuda);
         CudaFound = true;
       }
       if (!RocmFound && (Backend == backend::rocm || Backend == backend::all)) {
-        PluginNames.emplace_back(__SYCL_ROCM_PLUGIN_NAME, backend::rocm);
+        PluginNames.emplace_back(ROCMPluginName, backend::rocm);
         RocmFound = true;
       }
     }
   }
-  return true;
+  return PluginNames;
 }
 
 // Load the Plugin by calling the OS dependent library loading call.
@@ -321,8 +335,7 @@ const std::vector<plugin> &initialize() {
 }
 
 static void initializePlugins(std::vector<plugin> *Plugins) {
-  std::vector<std::pair<std::string, backend>> PluginNames;
-  findPlugins(PluginNames);
+  std::vector<std::pair<std::string, backend>> PluginNames = findPlugins();
 
   if (PluginNames.empty() && trace(PI_TRACE_ALL))
     std::cerr << "SYCL_PI_TRACE[all]: "

sycl/test/basic_tests/pluign_overrides_negative.cpp

@@ -0,0 +1,16 @@
+// RUN: %clangxx -fsycl %s -o %t.out
+// RUN: env SYCL_OVERRIDE_PI_OPENCL=opencl_test env SYCL_OVERRIDE_PI_LEVEL_ZERO=l0_test env SYCL_OVERRIDE_PI_CUDA=cuda_test env SYCL_OVERRIDE_PI_ROCM=rocm_test env SYCL_PI_TRACE=-1 %t.out > %t.log 2>&1
+// RUN: FileCheck %s --input-file %t.log
+
+#include <sycl/sycl.hpp>
+
+int main() {
+  sycl::queue Q;
+
+  return 0;
+}
+
+// CHECK: SYCL_PI_TRACE[all]: Check if plugin is present. Failed to load plugin: opencl_test
+// CHECK: SYCL_PI_TRACE[all]: Check if plugin is present. Failed to load plugin: l0_test
+// CHECK: SYCL_PI_TRACE[all]: Check if plugin is present. Failed to load plugin: cuda_test
+// CHECK: SYCL_PI_TRACE[all]: Check if plugin is present. Failed to load plugin: rocm_test

sycl/test/basic_tests/pluign_overrides_positive.cpp

@@ -0,0 +1,43 @@
+// RUN: %clangxx -fsycl -DFAKE_PLUGIN -shared %s -o %t_fake_plugin.so
+// RUN: %clangxx -fsycl %s -o %t.out
+// RUN: env SYCL_OVERRIDE_PI_OPENCL=%t_fake_plugin.so env SYCL_OVERRIDE_PI_LEVEL_ZERO=%t_fake_plugin.so env SYCL_OVERRIDE_PI_CUDA=%t_fake_plugin.so env SYCL_OVERRIDE_PI_ROCM=%t_fake_plugin.so env SYCL_PI_TRACE=-1 %t.out > %t.log 2>&1
+// RUN: FileCheck %s --input-file %t.log
+// REQUIRES: linux
+
+#ifdef FAKE_PLUGIN
+
+#include <CL/sycl/detail/pi.h>
+
+pi_result piPlatformsGet(pi_uint32 NumEntries, pi_platform *Platforms,
+                         pi_uint32 *NumPlatforms) {
+  return PI_INVALID_OPERATION;
+}
+
+pi_result piTearDown(void *) { return PI_SUCCESS; }
+
+pi_result piPluginInit(pi_plugin *PluginInit) {
+  PluginInit->PiFunctionTable.piPlatformsGet = piPlatformsGet;
+  PluginInit->PiFunctionTable.piTearDown = piTearDown;
+  return PI_SUCCESS;
+}
+
+#else
+
+#include <sycl/sycl.hpp>
+
+int main() {
+  try {
+    sycl::platform P{sycl::default_selector{}};
+  } catch (...) {
+    // NOP
+  }
+
+  return 0;
+}
+
+#endif
+
+// CHECK: SYCL_PI_TRACE[basic]: Plugin found and successfully loaded: {{[0-9a-zA-Z_\/\.-]+}}_fake_plugin.so
+// CHECK: SYCL_PI_TRACE[basic]: Plugin found and successfully loaded: {{[0-9a-zA-Z_\/\.-]+}}_fake_plugin.so
+// CHECK: SYCL_PI_TRACE[basic]: Plugin found and successfully loaded: {{[0-9a-zA-Z_\/\.-]+}}_fake_plugin.so
+// CHECK: SYCL_PI_TRACE[basic]: Plugin found and successfully loaded: {{[0-9a-zA-Z_\/\.-]+}}_fake_plugin.so