[SYCL][UR] Log sycl-ls error messages related to adapter loading

sycl/tools/sycl-ls/sycl-ls.cpp

@@ -28,6 +28,11 @@
 #ifdef _WIN32
 #include <system_error>
 #include <windows.h>
+
+#define setenv(name, var, ignore) _putenv_s(name, var)
+#define unsetenv(name) _putenv_s(name, "")
+#else
+
 #endif
 
 using namespace sycl;
@@ -261,11 +266,7 @@ static void printWarningIfFiltersUsed(bool &SuppressNumberPrinting) {
 // ONEAPI_DEVICE_SELECTOR, and SYCL_DEVICE_ALLOWLIST.
 static void unsetFilterEnvVars() {
   for (const auto &it : FilterEnvVars) {
-#ifdef _WIN32
-    _putenv_s(it.c_str(), "");
-#else
     unsetenv(it.c_str());
-#endif
   }
 }
 
@@ -363,8 +364,22 @@ int main(int argc, char **argv) {
     if (DiscardFilters && FilterEnvVars.size())
       unsetFilterEnvVars();
 
+    // Store the original UR_LOG_LOADER environment variable and enable printing
+    // of any errors related to adapter loading.
+    const char *orig_ur_log_loader_var = std::getenv("UR_LOG_LOADER");
+    std::string orig_ur_log_loader_var_str;
+    if (orig_ur_log_loader_var != NULL)
+      orig_ur_log_loader_var_str.assign(orig_ur_log_loader_var);
+
+    setenv("UR_LOG_LOADER", "level:error;output:stderr", 1);
+
     const auto &Platforms = platform::get_platforms();
 
+    if (orig_ur_log_loader_var == NULL)
+      unsetenv("UR_LOG_LOADER");
+    else
+      setenv("UR_LOG_LOADER", orig_ur_log_loader_var_str.c_str(), 1);
+
     // Keep track of the number of devices per backend
     std::map<backend, size_t> DeviceNums;
 

unified-runtime/source/common/linux/ur_lib_loader.cpp

@@ -50,9 +50,20 @@ LibLoader::loadAdapterLibrary(const char *name) {
 #endif
   HMODULE handle = dlopen(name, mode);
   if (!handle) {
-    char *err = dlerror();
-    logger::info("failed to load adapter '{}' with error: {}", name,
-                 err ? err : "unknown error");
+    const char *err = dlerror();
+
+    // Check if the error string does not contain the adapter name or if it
+    // contains a "required by" (missing symbol) message.
+    if (err &&
+        (strstr(err, name) == NULL || strstr(err, "required by") != NULL)) {
+      // If the adapter cannot be loaded due to missing dependencies or any
+      // other related error, it is considered as an error.
+      logger::error("failed to load adapter '{}' with error: {}", name, err);
+    } else {
+      // Simply having the adapter library missing isn't an error.
+      logger::info("failed to load adapter '{}' with error: {}", name,
+                   err ? err : "unknown error");
+    }
   } else {
 #if defined(ADD_FULL_PATH_LOG)
     struct link_map *dlinfo_map;