Revert "[SYCL] Allow overriding plugin libraries (#4067)" (#4659)

This reverts commit 29f3a92.

There're ways of achieving the same without SYCL runtime modifications.

Author: Alexander Batashev

sycl/source/detail/config.def

@@ -34,8 +34,4 @@ 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_HIP, 1024, __SYCL_OVERRIDE_PI_HIP)
 CONFIG(SYCL_ENABLE_DEFAULT_CONTEXTS, 1, __SYCL_ENABLE_DEFAULT_CONTEXTS)

sycl/source/detail/pi.cpp

@@ -278,26 +278,13 @@ std::vector<std::pair<std::string, backend>> findPlugins() {
   // 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 *HIPPluginName = SYCLConfig<SYCL_OVERRIDE_PI_HIP>::get()
-                                  ? SYCLConfig<SYCL_OVERRIDE_PI_HIP>::get()
-                                  : __SYCL_HIP_PLUGIN_NAME;
   device_filter_list *FilterList = SYCLConfig<SYCL_DEVICE_FILTER>::get();
   if (!FilterList) {
-    PluginNames.emplace_back(OpenCLPluginName, backend::opencl);
-    PluginNames.emplace_back(L0PluginName, backend::level_zero);
-    PluginNames.emplace_back(CUDAPluginName, backend::cuda);
-    PluginNames.emplace_back(HIPPluginName, backend::hip);
+    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_HIP_PLUGIN_NAME, backend::hip);
   } else {
     std::vector<device_filter> Filters = FilterList->get();
     bool OpenCLFound = false;
@@ -308,20 +295,21 @@ std::vector<std::pair<std::string, backend>> findPlugins() {
       backend Backend = Filter.Backend;
       if (!OpenCLFound &&
           (Backend == backend::opencl || Backend == backend::all)) {
-        PluginNames.emplace_back(OpenCLPluginName, backend::opencl);
+        PluginNames.emplace_back(__SYCL_OPENCL_PLUGIN_NAME, backend::opencl);
         OpenCLFound = true;
       }
       if (!LevelZeroFound &&
           (Backend == backend::level_zero || Backend == backend::all)) {
-        PluginNames.emplace_back(L0PluginName, backend::level_zero);
+        PluginNames.emplace_back(__SYCL_LEVEL_ZERO_PLUGIN_NAME,
+                                 backend::level_zero);
         LevelZeroFound = true;
       }
       if (!CudaFound && (Backend == backend::cuda || Backend == backend::all)) {
-        PluginNames.emplace_back(CUDAPluginName, backend::cuda);
+        PluginNames.emplace_back(__SYCL_CUDA_PLUGIN_NAME, backend::cuda);
         CudaFound = true;
       }
       if (!HIPFound && (Backend == backend::hip || Backend == backend::all)) {
-        PluginNames.emplace_back(HIPPluginName, backend::hip);
+        PluginNames.emplace_back(__SYCL_HIP_PLUGIN_NAME, backend::hip);
         HIPFound = true;
       }
     }