[UR] Logger callback function sink (#17095)

Migrated from oneapi-src/unified-runtime#1748

This PR implements
oneapi-src/unified-runtime#1330 through a new
logger sink: a user configurable callback. It introduces some spec
additions:

- `typedef void (*ur_logger_output_callback_t)(ur_logger_level_t level,
const char *pLoggerMsg, void *pUserData)`
- `urSetLoggerCallback(ur_adapter_handle_t hAdapter,
ur_logger_output_callback_t pfnLoggerCallback, void *pUserData,
ur_logger_level_t level`
)`
- `urSetLoggerCallbackLevel(ur_adapter_handle_t hAdapter,
ur_logger_level_t level)`
- `typedef enum ur_logger_level_t` (moved the logger::level enum into
the spec)

This new logger sink will only be constructed once a user makes a call
to `urSetLoggerCallback` (which is called from the UR
`urAdapterSetLoggerCallback` entry point), supplying their own callback
function. They can set the minimum logging level through
`urSetLoggerCallbackLevel`. Any subsequent logging calls will
additionally make a call to the supplied callback where the log level,
message and user data will be sent.

A callback has been setup in the SYCL RT in `sycl/source/detail/ur.cpp`
to print logs to `std::err`:
```
void urLoggerCallback([[maybe_unused]] ur_logger_level_t level, const char *msg,
                      [[maybe_unused]] void *userData) {
  std::cerr << msg << std::endl;
}
```

A new test suite `LoggerWithCallbackSink` has been added to test this
new functionality.

---------

Co-authored-by: Kenneth Benzie (Benie) <k.benzie83@gmail.com>

Author: martygrant

Diff for: sycl/source/detail/ur.cpp

@@ -77,6 +77,11 @@ void *getAdapterOpaqueData([[maybe_unused]] void *OpaqueDataParam) {
 
 ur_code_location_t codeLocationCallback(void *);
 
+void urLoggerCallback([[maybe_unused]] ur_logger_level_t level, const char *msg,
+                      [[maybe_unused]] void *userData) {
+  std::cerr << msg << std::endl;
+}
+
 namespace ur {
 bool trace(TraceLevel Level) {
   auto TraceLevelMask = SYCLConfig<SYCL_UR_TRACE>::get();
@@ -138,6 +143,11 @@ static void initializeAdapters(std::vector<AdapterPtr> &Adapters,
   UrFuncInfo<UrApiKind::urAdapterGetInfo> adapterGetInfoInfo;
   auto adapterGetInfo =
       adapterGetInfoInfo.getFuncPtrFromModule(ur::getURLoaderLibrary());
+  UrFuncInfo<UrApiKind::urAdapterSetLoggerCallback>
+      adapterSetLoggerCallbackInfo;
+  auto adapterSetLoggerCallback =
+      adapterSetLoggerCallbackInfo.getFuncPtrFromModule(
+          ur::getURLoaderLibrary());
 
   bool OwnLoaderConfig = false;
   // If we weren't provided with a custom config handle create our own.
@@ -219,6 +229,12 @@ static void initializeAdapters(std::vector<AdapterPtr> &Adapters,
                                     nullptr));
     auto syclBackend = UrToSyclBackend(adapterBackend);
     Adapters.emplace_back(std::make_shared<Adapter>(UrAdapter, syclBackend));
+
+    const char *env_value = std::getenv("UR_LOG_CALLBACK");
+    if (env_value == nullptr || std::string(env_value) != "disabled") {
+      CHECK_UR_SUCCESS(adapterSetLoggerCallback(UrAdapter, urLoggerCallback,
+                                                nullptr, UR_LOGGER_LEVEL_INFO));
+    }
   }
 
 #ifdef XPTI_ENABLE_INSTRUMENTATION

Diff for: sycl/test-e2e/External/README.md

@@ -76,4 +76,3 @@ cmake \
 make check-sycl-e2e
 
 ```
-

Diff for: sycl/test-e2e/lit.cfg.py

@@ -168,6 +168,8 @@
             lit_config.note("\tUnset " + var)
             llvm_config.with_environment(var, "")
 
+# Disable the UR logger callback sink during test runs as output to SYCL RT can interfere with some tests relying on standard input/output
+llvm_config.with_environment("UR_LOG_CALLBACK", "disabled")
 
 # Temporarily modify environment to be the same that we use when running tests
 class test_env:

Diff for: sycl/test/Unit/lit.cfg.py

@@ -95,3 +95,6 @@ def find_shlibpath_var():
 
 config.environment["SYCL_CACHE_DIR"] = config.llvm_obj_root + "/sycl_cache"
 lit_config.note("SYCL cache directory: {}".format(config.environment["SYCL_CACHE_DIR"]))
+
+# Disable the UR logger callback sink during test runs as output to SYCL RT can interfere with some tests relying on standard input/output
+config.environment["UR_LOG_CALLBACK"] = "disabled"

Diff for: sycl/test/lit.cfg.py

@@ -186,6 +186,9 @@
         )
     )
 
+# Disable the UR logger callback sink during test runs as output to SYCL RT can interfere with some tests relying on standard input/output
+llvm_config.with_environment("UR_LOG_CALLBACK", "disabled")
+
 # Dump-only tests do not have clang available
 if not dump_only_tests:
     llvm_config.use_clang(additional_flags=additional_flags)