[BUILD] Revisit EventLogger deprecation

CHANGELOG.md

@@ -15,6 +15,18 @@ Increment the:
 
 ## [Unreleased]
 
+* [BUILD] Revisit EventLogger deprecation
+  [#3855](https://github.com/open-telemetry/opentelemetry-cpp/pull/3855)
+
+Important changes:
+
+* [BUILD] Revisit EventLogger deprecation
+  [#3855](https://github.com/open-telemetry/opentelemetry-cpp/pull/3855)
+
+  * File `DEPRECATED.md` contains information about current deprecation
+    plans.
+  * Please adjust your application accordingly, to avoid disruption.
+
 ## [1.25 2026-02-07]
 
 * [RELEASE] Bump main branch to 1.25.0-dev (#3759)

DEPRECATED.md

@@ -46,7 +46,87 @@ N/A
 
 ## [opentelemetry-cpp API]
 
-N/A
+### Deprecation of EventLogger
+
+#### Announcement (EventLogger)
+
+The `EventLogger` API was deprecated by:
+
+* [API] Deprecate event logger
+  [#3285](https://github.com/open-telemetry/opentelemetry-cpp/pull/3285)
+
+on Feb 25, 2025, as published in release 1.20.
+
+#### Motivation (EventLogger)
+
+The specification for `EventLogger` was deprecated by:
+
+* Deprecate Event API and SDK in favor of Emit Event in the Log API
+  [#4319](https://github.com/open-telemetry/opentelemetry-specification/pull/4319)
+
+The opentelemetry-cpp API and SDK deprecates the EventLogger to be aligned
+with the opentelemetry specification.
+
+#### Scope (EventLogger)
+
+The following classes or methods are deprecated in ABI version 1:
+
+* API
+  * class opentelemetry::logs::EventLogger
+  * class opentelemetry::logs::EventLoggerProvider
+  * class opentelemetry::logs::NoopEventLogger
+  * class opentelemetry::logs::NoopEventLoggerProvider
+  * method opentelemetry::logs::Provider::GetEventLoggerProvider()
+  * method opentelemetry::logs::Provider::SetEventLoggerProvider()
+* SDK
+  * class opentelemetry::sdk::logs::EventLogger
+  * class opentelemetry::sdk::logs::EventLoggerProvider
+  * class opentelemetry::sdk::logs::EventLoggerProviderFactory
+
+The same are removed from ABI version 2.
+
+#### Mitigation (EventLogger)
+
+In respective order, the following should be used in place of `EventLogger`:
+
+* API
+  * class opentelemetry::logs::Logger
+  * class opentelemetry::logs::LoggerProvider
+  * class opentelemetry::logs::NoopLogger
+  * class opentelemetry::logs::NoopLoggerProvider
+  * method opentelemetry::logs::Provider::GetLoggerProvider()
+  * method opentelemetry::logs::Provider::SetLoggerProvider()
+* SDK
+  * class opentelemetry::sdk::logs::Logger
+  * class opentelemetry::sdk::logs::LoggerProvider
+  * class opentelemetry::sdk::logs::LoggerProviderFactory
+
+Instrumented applications, that currently use
+`opentelemetry::logs::Provider::GetEventLoggerProvider()`,
+are strongly encouraged to migrate and use
+`opentelemetry::logs::Provider::GetLoggerProvider()` instead.
+
+Main applications, when installing and configuring an SDK, that currently use
+`opentelemetry::logs::Provider::SetEventLoggerProvider()`,
+are strongly encouraged to migrate and use
+`opentelemetry::logs::Provider::SetLoggerProvider()` instead.
+
+This migration can be implemented now,
+as `Logger` is available already in ABI version 1.
+
+This migration is mandatory and a pre requisite for adoption of ABI version 2 later.
+
+#### Planned removal (EventLogger)
+
+All the deprecated code is already removed from ABI version 2, since Feb
+2025.
+
+While EventLogger will not be removed from ABI version 1,
+the ABI version 1 itself will be deprecated and decommissioned in the long
+term, after ABI version 2 is declared stable.
+
+By the time only ABI version 2 is available and supported,
+any code still using the deprecated `EventLogger` will break.
 
 ## [opentelemetry-cpp SDK]
 

api/include/opentelemetry/logs/event_logger.h

@@ -15,21 +15,11 @@ OPENTELEMETRY_BEGIN_NAMESPACE
 namespace logs
 {
 #if OPENTELEMETRY_ABI_VERSION_NO < 2
-#  if defined(_MSC_VER)
-#    pragma warning(push)
-#    pragma warning(disable : 4996)
-#  elif defined(__GNUC__) && !defined(__clang__) && !defined(__apple_build_version__)
-#    pragma GCC diagnostic push
-#    pragma GCC diagnostic ignored "-Wdeprecated-declarations"
-#  elif defined(__clang__) || defined(__apple_build_version__)
-#    pragma clang diagnostic push
-#    pragma clang diagnostic ignored "-Wdeprecated-declarations"
-#  endif
-
 /**
  * Handles event log record creation.
+ * @deprecated
  **/
-class OPENTELEMETRY_DEPRECATED EventLogger
+class EventLogger
 {
 public:
   virtual ~EventLogger() = default;
@@ -88,14 +78,6 @@ class OPENTELEMETRY_DEPRECATED EventLogger
   void IgnoreTraitResult(ValueType &&...)
   {}
 };
-
-#  if defined(_MSC_VER)
-#    pragma warning(pop)
-#  elif defined(__GNUC__) && !defined(__clang__) && !defined(__apple_build_version__)
-#    pragma GCC diagnostic pop
-#  elif defined(__clang__) || defined(__apple_build_version__)
-#    pragma clang diagnostic pop
-#  endif
 #endif
 }  // namespace logs
 OPENTELEMETRY_END_NAMESPACE

api/include/opentelemetry/logs/event_logger_provider.h

@@ -15,21 +15,11 @@ class EventLogger;
 class Logger;
 
 #if OPENTELEMETRY_ABI_VERSION_NO < 2
-#  if defined(_MSC_VER)
-#    pragma warning(push)
-#    pragma warning(disable : 4996)
-#  elif defined(__GNUC__) && !defined(__clang__) && !defined(__apple_build_version__)
-#    pragma GCC diagnostic push
-#    pragma GCC diagnostic ignored "-Wdeprecated-declarations"
-#  elif defined(__clang__) || defined(__apple_build_version__)
-#    pragma clang diagnostic push
-#    pragma clang diagnostic ignored "-Wdeprecated-declarations"
-#  endif
-
 /**
  * Creates new EventLogger instances.
+ * @deprecated
  */
-class OPENTELEMETRY_DEPRECATED EventLoggerProvider
+class EventLoggerProvider
 {
 public:
   virtual ~EventLoggerProvider() = default;
@@ -43,14 +33,6 @@ class OPENTELEMETRY_DEPRECATED EventLoggerProvider
       nostd::shared_ptr<Logger> delegate_logger,
       nostd::string_view event_domain) noexcept = 0;
 };
-
-#  if defined(_MSC_VER)
-#    pragma warning(pop)
-#  elif defined(__GNUC__) && !defined(__clang__) && !defined(__apple_build_version__)
-#    pragma GCC diagnostic pop
-#  elif defined(__clang__) || defined(__apple_build_version__)
-#    pragma clang diagnostic pop
-#  endif
 #endif
 }  // namespace logs
 OPENTELEMETRY_END_NAMESPACE

api/include/opentelemetry/logs/noop.h

@@ -91,17 +91,10 @@ class NoopLoggerProvider final : public LoggerProvider
 };
 
 #if OPENTELEMETRY_ABI_VERSION_NO < 2
-#  if defined(_MSC_VER)
-#    pragma warning(push)
-#    pragma warning(disable : 4996)
-#  elif defined(__GNUC__) && !defined(__clang__) && !defined(__apple_build_version__)
-#    pragma GCC diagnostic push
-#    pragma GCC diagnostic ignored "-Wdeprecated-declarations"
-#  elif defined(__clang__) || defined(__apple_build_version__)
-#    pragma clang diagnostic push
-#    pragma clang diagnostic ignored "-Wdeprecated-declarations"
-#  endif
-
+/**
+ * No-op implementation of a EventLogger.
+ * @deprecated
+ */
 class NoopEventLogger final : public EventLogger
 {
 public:
@@ -120,6 +113,7 @@ class NoopEventLogger final : public EventLogger
 
 /**
  * No-op implementation of a EventLoggerProvider.
+ * @deprecated
  */
 class NoopEventLoggerProvider final : public EventLoggerProvider
 {
@@ -138,14 +132,6 @@ class NoopEventLoggerProvider final : public EventLoggerProvider
 private:
   nostd::shared_ptr<EventLogger> event_logger_;
 };
-
-#  if defined(_MSC_VER)
-#    pragma warning(pop)
-#  elif defined(__GNUC__) && !defined(__clang__) && !defined(__apple_build_version__)
-#    pragma GCC diagnostic pop
-#  elif defined(__clang__) || defined(__apple_build_version__)
-#    pragma clang diagnostic pop
-#  endif
 #endif
 
 }  // namespace logs

api/include/opentelemetry/logs/provider.h

@@ -48,21 +48,12 @@ class OPENTELEMETRY_EXPORT Provider
   }
 
 #if OPENTELEMETRY_ABI_VERSION_NO < 2
-#  if defined(_MSC_VER)
-#    pragma warning(push)
-#    pragma warning(disable : 4996)
-#  elif defined(__GNUC__) && !defined(__clang__) && !defined(__apple_build_version__)
-#    pragma GCC diagnostic push
-#    pragma GCC diagnostic ignored "-Wdeprecated-declarations"
-#  elif defined(__clang__) || defined(__apple_build_version__)
-#    pragma clang diagnostic push
-#    pragma clang diagnostic ignored "-Wdeprecated-declarations"
-#  endif
   /**
    * Returns the singleton EventLoggerProvider.
    *
    * By default, a no-op EventLoggerProvider is returned. This will never return a
    * nullptr EventLoggerProvider.
+   * @deprecated
    */
   OPENTELEMETRY_DEPRECATED static nostd::shared_ptr<EventLoggerProvider>
   GetEventLoggerProvider() noexcept
@@ -73,20 +64,14 @@ class OPENTELEMETRY_EXPORT Provider
 
   /**
    * Changes the singleton EventLoggerProvider.
+   * @deprecated
    */
   OPENTELEMETRY_DEPRECATED static void SetEventLoggerProvider(
       const nostd::shared_ptr<EventLoggerProvider> &tp) noexcept
   {
     std::lock_guard<common::SpinLockMutex> guard(GetLock());
     GetEventProvider() = tp;
   }
-#  if defined(_MSC_VER)
-#    pragma warning(pop)
-#  elif defined(__GNUC__) && !defined(__clang__) && !defined(__apple_build_version__)
-#    pragma GCC diagnostic pop
-#  elif defined(__clang__) || defined(__apple_build_version__)
-#    pragma clang diagnostic pop
-#  endif
 #endif
 
 private:
@@ -97,32 +82,12 @@ class OPENTELEMETRY_EXPORT Provider
   }
 
 #if OPENTELEMETRY_ABI_VERSION_NO < 2
-#  if defined(_MSC_VER)
-#    pragma warning(push)
-#    pragma warning(disable : 4996)
-#  elif defined(__GNUC__) && !defined(__clang__) && !defined(__apple_build_version__)
-#    pragma GCC diagnostic push
-#    pragma GCC diagnostic ignored "-Wdeprecated-declarations"
-#  elif defined(__clang__) || defined(__apple_build_version__)
-#    pragma clang diagnostic push
-#    pragma clang diagnostic ignored "-Wdeprecated-declarations"
-#  endif
-
-  OPENTELEMETRY_DEPRECATED
   OPENTELEMETRY_API_SINGLETON static nostd::shared_ptr<EventLoggerProvider> &
   GetEventProvider() noexcept
   {
     static nostd::shared_ptr<EventLoggerProvider> provider(new NoopEventLoggerProvider);
     return provider;
   }
-
-#  if defined(_MSC_VER)
-#    pragma warning(pop)
-#  elif defined(__GNUC__) && !defined(__clang__) && !defined(__apple_build_version__)
-#    pragma GCC diagnostic pop
-#  elif defined(__clang__) || defined(__apple_build_version__)
-#    pragma clang diagnostic pop
-#  endif
 #endif
 
   OPENTELEMETRY_API_SINGLETON static common::SpinLockMutex &GetLock() noexcept

api/test/logs/logger_test.cc

@@ -161,6 +161,23 @@ TEST(Logger, LogMethodOverloads)
 }
 
 #if OPENTELEMETRY_ABI_VERSION_NO < 2
+
+/*
+ * opentelemetry::logs::Provider::GetLoggerProvider() is deprecated.
+ * Suppress warnings in tests, to have a clean build and coverage.
+ */
+
+#  if defined(_MSC_VER)
+#    pragma warning(push)
+#    pragma warning(disable : 4996)
+#  elif defined(__GNUC__) && !defined(__clang__) && !defined(__apple_build_version__)
+#    pragma GCC diagnostic push
+#    pragma GCC diagnostic ignored "-Wdeprecated-declarations"
+#  elif defined(__clang__) || defined(__apple_build_version__)
+#    pragma clang diagnostic push
+#    pragma clang diagnostic ignored "-Wdeprecated-declarations"
+#  endif
+
 TEST(Logger, EventLogMethodOverloads)
 {
   auto lp = Provider::GetLoggerProvider();
@@ -192,6 +209,15 @@ TEST(Logger, EventLogMethodOverloads)
   event_logger->EmitEvent("event name", Severity::kDebug,
                           opentelemetry::common::MakeAttributes(vec));
 }
+
+#  if defined(_MSC_VER)
+#    pragma warning(pop)
+#  elif defined(__GNUC__) && !defined(__clang__) && !defined(__apple_build_version__)
+#    pragma GCC diagnostic pop
+#  elif defined(__clang__) || defined(__apple_build_version__)
+#    pragma clang diagnostic pop
+#  endif
+
 #endif
 
 // Define a basic Logger class

api/test/logs/provider_test.cc

@@ -74,6 +74,24 @@ TEST(Provider, GetLogger)
 }
 
 #if OPENTELEMETRY_ABI_VERSION_NO < 2
+
+/*
+ * opentelemetry::logs::Provider::GetEventLoggerProvider() is deprecated.
+ * opentelemetry::logs::Provider::SetEventLoggerProvider() is deprecated.
+ * Suppress warnings in tests, to have a clean build and coverage.
+ */
+
+#  if defined(_MSC_VER)
+#    pragma warning(push)
+#    pragma warning(disable : 4996)
+#  elif defined(__GNUC__) && !defined(__clang__) && !defined(__apple_build_version__)
+#    pragma GCC diagnostic push
+#    pragma GCC diagnostic ignored "-Wdeprecated-declarations"
+#  elif defined(__clang__) || defined(__apple_build_version__)
+#    pragma clang diagnostic push
+#    pragma clang diagnostic ignored "-Wdeprecated-declarations"
+#  endif
+
 class TestEventLoggerProvider : public EventLoggerProvider
 {
 public:
@@ -115,4 +133,13 @@ TEST(Provider, CreateEventLogger)
 
   EXPECT_EQ(nullptr, logger);
 }
+
+#  if defined(_MSC_VER)
+#    pragma warning(pop)
+#  elif defined(__GNUC__) && !defined(__clang__) && !defined(__apple_build_version__)
+#    pragma GCC diagnostic pop
+#  elif defined(__clang__) || defined(__apple_build_version__)
+#    pragma clang diagnostic pop
+#  endif
+
 #endif