[SYCL] Improve plugins loading (#6658)

Author: romanovvlad

sycl/source/detail/pi.cpp

@@ -387,12 +387,15 @@ static void initializePlugins(std::vector<plugin> &Plugins) {
     std::cerr << "SYCL_PI_TRACE[all]: "
               << "No Plugins Found." << std::endl;
 
+  const std::string LibSYCLDir =
+      sycl::detail::OSUtil::getCurrentDSODir() + sycl::detail::OSUtil::DirSep;
+
   for (unsigned int I = 0; I < PluginNames.size(); I++) {
     std::shared_ptr<PiPlugin> PluginInformation = std::make_shared<PiPlugin>(
         PiPlugin{_PI_H_VERSION_STRING, _PI_H_VERSION_STRING,
                  /*Targets=*/nullptr, /*FunctionPointers=*/{}});
 
-    void *Library = loadPlugin(PluginNames[I].first);
+    void *Library = loadPlugin(LibSYCLDir + PluginNames[I].first);
 
     if (!Library) {
       if (trace(PI_TRACE_ALL)) {

sycl/test/basic_tests/library_loading.cpp

@@ -8,9 +8,9 @@
 using namespace sycl;
 
 int main() {
-  // CHECK: {{(SYCL_PI_TRACE\[-1\]: dlopen\(libpi_cuda.so\) failed with)|(SYCL_PI_TRACE\[basic\]: Plugin found and successfully loaded: libpi_cuda.so)}}
-  // CHECK: {{(SYCL_PI_TRACE\[-1\]: dlopen\(libpi_hip.so\) failed with)|(SYCL_PI_TRACE\[basic\]: Plugin found and successfully loaded: libpi_hip.so)}}
-  // CHECK: {{(SYCL_PI_TRACE\[-1\]: dlopen\(libpi_esimd_emulator.so\) failed with)|(SYCL_PI_TRACE\[basic\]: Plugin found and successfully loaded: libpi_esimd_emulator.so)}}
+  // CHECK: {{(SYCL_PI_TRACE\[-1\]: dlopen\(.*/libpi_cuda.so\) failed with)|(SYCL_PI_TRACE\[basic\]: Plugin found and successfully loaded: libpi_cuda.so)}}
+  // CHECK: {{(SYCL_PI_TRACE\[-1\]: dlopen\(.*/libpi_hip.so\) failed with)|(SYCL_PI_TRACE\[basic\]: Plugin found and successfully loaded: libpi_hip.so)}}
+  // CHECK: {{(SYCL_PI_TRACE\[-1\]: dlopen\(.*/libpi_esimd_emulator.so\) failed with)|(SYCL_PI_TRACE\[basic\]: Plugin found and successfully loaded: libpi_esimd_emulator.so)}}
   queue q;
   q.submit([&](handler &cgh) {});
 }