Restore some of ZE_ENABLE_LOADER_DEBUG_TRACE

Signed-off-by: Russell McGuire <russell.w.mcguire@intel.com>

Author: rwmcguir

README.md

@@ -46,14 +46,19 @@ When the `-DBUILD_STATIC=1` is executed, the dynamic loader and layers are not b
 Testing with the static loader requires a build of the dynamic loader or an installation of the dynamic loader to exist in the library path.
 
 # Debug Trace
+
+> **Deprecated:** `ZE_ENABLE_LOADER_DEBUG_TRACE` is deprecated and will be removed in a future release.
+> Use `ZEL_LOADER_LOG_CONSOLE=1` with `ZEL_LOADER_LOGGING_LEVEL=trace` instead, which provides
+> the same or enhanced information with structured timestamps, thread IDs, and log levels via the logging system.
+
 The Level Zero Loader has the ability to print warnings and errors which occur within the internals of the Level Zero Loader itself.
 
 To enable this debug tracing feature, set the environment variable `ZE_ENABLE_LOADER_DEBUG_TRACE=1`.
 
 This will enforce the Loader to print all errors whether fatal or non-fatal to stderr with the PREFIX `ZE_LOADER_DEBUG_TRACE:`.
 
 
-# Logging to File
+# Logging to File or Console
 The Level Zero Loader provides built-in logging controlled via environment variables:
 
 | Environment Variable | Default | Description |

source/lib/ze_lib.cpp

@@ -64,6 +64,10 @@ namespace ze_lib
     __zedlllocal context_t::context_t()
     {
         debugTraceEnabled = getenv_tobool( "ZE_ENABLE_LOADER_DEBUG_TRACE" );
+        if (debugTraceEnabled) {
+            std::cerr << "ZE_LOADER_DEBUG_TRACE: WARNING: ZE_ENABLE_LOADER_DEBUG_TRACE is deprecated and will be removed in a future release." << std::endl;
+            std::cerr << "ZE_LOADER_DEBUG_TRACE: WARNING: Use ZEL_LOADER_LOG_CONSOLE=1 with ZEL_LOADER_LOGGING_LEVEL=trace instead." << std::endl;
+        }
         memset(&initialzeDdiTable, 0, sizeof(ze_dditable_t));
         memset(&initialzetDdiTable, 0, sizeof(zet_dditable_t));
         memset(&initialzesDdiTable, 0, sizeof(zes_dditable_t));

source/loader/ze_loader.cpp

@@ -25,6 +25,9 @@ namespace loader
     context_t *context;
 
     void context_t::debug_trace_message(std::string message, std::string result) {
+        if (debugTraceEnabled) {
+            std::cerr << "ZE_LOADER_DEBUG_TRACE:" << message << result << std::endl;
+        }
         zel_logger->log_trace(message + result);
     };
 
@@ -618,6 +621,10 @@ namespace loader
         loader::loaderDispatch->pRuntime->version = ZE_API_VERSION_CURRENT;
         loader::loaderDispatch->pRuntime->isValidFlag = 1;
         debugTraceEnabled = getenv_tobool( "ZE_ENABLE_LOADER_DEBUG_TRACE" );
+        if (debugTraceEnabled) {
+            std::cerr << "ZE_LOADER_DEBUG_TRACE: WARNING: ZE_ENABLE_LOADER_DEBUG_TRACE is deprecated and will be removed in a future release." << std::endl;
+            std::cerr << "ZE_LOADER_DEBUG_TRACE: WARNING: Use ZEL_LOADER_LOG_CONSOLE=1 with ZEL_LOADER_LOGGING_LEVEL=trace instead." << std::endl;
+        }
         // DDI Driver Extension Path is enabled by default.
         // This can be overridden by the environment variable ZE_ENABLE_LOADER_DRIVER_DDI_PATH.
         std::string ddiPathConfig = getenv_string("ZE_ENABLE_LOADER_DRIVER_DDI_PATH");

source/utils/CMakeLists.txt

@@ -7,3 +7,10 @@ add_library(level_zero_utils STATIC ${logging_files})
 target_include_directories(level_zero_utils PUBLIC ${CMAKE_CURRENT_SOURCE_DIR})
 
 set_property(TARGET level_zero_utils PROPERTY POSITION_INDEPENDENT_CODE ON)
+
+# Hide all symbols — ZeLogger is an internal implementation detail, not a public ABI.
+# Each consumer (loader, validation layer, static shim) links its own copy.
+# Prevents runtime symbol interposition when multiple copies coexist in one process.
+if(NOT WIN32)
+    target_compile_options(level_zero_utils PRIVATE -fvisibility=hidden -fvisibility-inlines-hidden)
+endif()