OpenTelemetry ApiView fix (#3784)

eng/scripts/Get-ApiViewCommandLine.ps1

@@ -50,4 +50,9 @@ foreach ($incDir in $AllLibIncDirs) {
     $CmdLine += " -I " + $incDir
 }
 
+# Define an _azure_APIVIEW macro so that the public headers that depend on 3rd party headers apply a work around
+# for declaring 3rd party dependencies in a minimalistic way that is sufficient for the ApiView generation.
+# Otherwise, ApiView would've been including 3rd party types for review, which is not what we want.
+$CmdLine += " -D_azure_APIVIEW"
+
 $CmdLine

sdk/core/azure-core-tracing-opentelemetry/CMakeLists.txt

@@ -40,6 +40,7 @@ if (BUILD_AZURE_CORE_TRACING_OPENTELEMETRY)
 
     set(
       AZURE_CORE_OPENTELEMETRY_HEADER
+        inc/azure/core/tracing/opentelemetry/internal/apiview.hpp
         inc/azure/core/tracing/opentelemetry/opentelemetry.hpp
         src/opentelemetry_private.hpp
     )

sdk/core/azure-core-tracing-opentelemetry/inc/azure/core/tracing/opentelemetry/internal/apiview.hpp

@@ -0,0 +1,22 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+#pragma once
+
+// This file is supposed to be included only when generating files for ApiView.
+// All the declarations here are only sufficient for the ApiView generation to not fail.
+
+namespace opentelemetry {
+namespace nostd {
+  template <typename> struct shared_ptr
+  {
+  };
+} // namespace nostd
+namespace trace {
+  struct TracerProvider;
+  struct Provider
+  {
+    static nostd::shared_ptr<TracerProvider> GetTracerProvider();
+  };
+} // namespace trace
+} // namespace opentelemetry

sdk/core/azure-core-tracing-opentelemetry/inc/azure/core/tracing/opentelemetry/opentelemetry.hpp

@@ -4,6 +4,10 @@
 #pragma once
 
 #include <azure/core/tracing/tracing.hpp>
+
+#if defined(_azure_APIVIEW)
+#include "azure/core/tracing/opentelemetry/internal/apiview.hpp"
+#else
 #if defined(_MSC_VER)
 // The OpenTelemetry headers generate a couple of warnings on MSVC in the OTel 1.2 package, suppress
 // the warnings across the includes.
@@ -17,6 +21,7 @@
 #if defined(_MSC_VER)
 #pragma warning(pop)
 #endif
+#endif
 
 namespace Azure { namespace Core { namespace Tracing { namespace OpenTelemetry {