From 48bb3c8642602f9ecec9bc05d48782a527ea7c66 Mon Sep 17 00:00:00 2001
From: Tyler Yahn <MrAlias@users.noreply.github.com>
Date: Sun, 18 Feb 2024 07:51:13 -0800
Subject: [PATCH] Add the `log/embedded` package (#4932)

* Add the log/embedded package

* Embed the Logger and LoggerProvider types
---
 log/embedded/embedded.go | 47 ++++++++++++++++++++++++++++++++++++++++
 log/logger.go            |  6 ++++-
 log/provider.go          |  7 +++++-
 3 files changed, 58 insertions(+), 2 deletions(-)
 create mode 100644 log/embedded/embedded.go

diff --git a/log/embedded/embedded.go b/log/embedded/embedded.go
new file mode 100644
index 000000000..eeecbdae1
--- /dev/null
+++ b/log/embedded/embedded.go
@@ -0,0 +1,47 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package embedded provides interfaces embedded within the [OpenTelemetry Logs
+// Bridge API].
+//
+// Implementers of the [OpenTelemetry Logs Bridge API] can embed the relevant
+// type from this package into their implementation directly. Doing so will
+// result in a compilation error for users when the [OpenTelemetry Logs Bridge
+// API] is extended (which is something that can happen without a major version
+// bump of the API package).
+//
+// [OpenTelemetry Logs Bridge API]: https://github.com/open-telemetry/opentelemetry-go/tree/d3dcb3999c5689a7bb803cb0529e55a651ed14f1/log
+package embedded // import "go.opentelemetry.io/otel/log/embedded"
+
+// LoggerProvider is embedded in the [Logs Bridge API LoggerProvider].
+//
+// Embed this interface in your implementation of the [Logs Bridge API
+// LoggerProvider] if you want users to experience a compilation error,
+// signaling they need to update to your latest implementation, when the [Logs
+// Bridge API LoggerProvider] interface is extended (which is something that
+// can happen without a major version bump of the API package).
+//
+// [Logs Bridge API LoggerProvider]: https://github.com/open-telemetry/opentelemetry-go/blob/d3dcb3999c5689a7bb803cb0529e55a651ed14f1/log/provider.go#L22-L32
+type LoggerProvider interface{ loggerProvider() }
+
+// Logger is embedded in [Logs Bridge API Logger].
+//
+// Embed this interface in your implementation of the [Logs Bridge API Logger]
+// if you want users to experience a compilation error, signaling they need to
+// update to your latest implementation, when the [Logs Bridge API Logger]
+// interface is extended (which is something that can happen without a major
+// version bump of the API package).
+//
+// [Logs Bridge API Logger]: https://github.com/open-telemetry/opentelemetry-go/blob/d3dcb3999c5689a7bb803cb0529e55a651ed14f1/log/logger.go#L28-L39
+type Logger interface{ logger() }
diff --git a/log/logger.go b/log/logger.go
index aefc42c2b..2b00ba094 100644
--- a/log/logger.go
+++ b/log/logger.go
@@ -18,6 +18,7 @@ import (
 	"context"
 
 	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/log/embedded"
 )
 
 // Logger emits log records.
@@ -26,7 +27,10 @@ import (
 // package documentation on API implementation for information on how to set
 // default behavior for unimplemented methods.
 type Logger interface {
-	// TODO (#4909): embed an embedded type from otel/log/embedded.
+	// Users of the interface can ignore this. This embedded type is only used
+	// by implementations of this interface. See the "API Implementations"
+	// section of the package documentation for more information.
+	embedded.Logger
 
 	// Emit emits a log record.
 	//
diff --git a/log/provider.go b/log/provider.go
index 76c870ac2..4a0da4023 100644
--- a/log/provider.go
+++ b/log/provider.go
@@ -14,13 +14,18 @@
 
 package log // import "go.opentelemetry.io/otel/log"
 
+import "go.opentelemetry.io/otel/log/embedded"
+
 // LoggerProvider provides access to [Logger].
 //
 // Warning: Methods may be added to this interface in minor releases. See
 // package documentation on API implementation for information on how to set
 // default behavior for unimplemented methods.
 type LoggerProvider interface {
-	// TODO (#4909): embed an embedded type from otel/log/embedded.
+	// Users of the interface can ignore this. This embedded type is only used
+	// by implementations of this interface. See the "API Implementations"
+	// section of the package documentation for more information.
+	embedded.LoggerProvider
 
 	// Logger returns a new [Logger] with the provided name and configuration.
 	//