Compilation error on Windows with MSVC 19.41.34120.0

[magnushakansson]

Describe the bug

When building with following parameters to CMake:

-DCMAKE_MSVC_RUNTIME_LIBRARY=MultiThreaded$<$<CONFIG:Debug>:Debug>
-DBUILD_ONLY=s3;s3-crt
-DBUILD_SHARED_LIBS=OFF
-DCPP_STANDARD=17
-DCUSTOM_MEMORY_MANAGEMENT=ON
-DENABLE_TESTING=OFF
-DFORCE_SHARED_CRT=OFF
-DAWS_STATIC_MSVC_RUNTIME_LIBRARY=ON

I get:

09:53:34  C:\Jws\qix-pc3-build-ws\build\aws-sdk-cpp\lib\src\aws-cpp-sdk-core\include\smithy\client\schema\JsonTraits.h(24,46): error C2220: the following warning is treated as an error [C:\Jws\qix-pc3-build-ws\build\aws-sdk-cpp\out\x64\src\aws-cpp-sdk-core\aws-cpp-sdk-core.vcxproj]
09:53:34    (compiling source file '../../../../lib/src/aws-cpp-sdk-core/source/smithy/client/schema/TraitKey.cpp')
09:53:34    
09:53:34  C:\Jws\qix-pc3-build-ws\build\aws-sdk-cpp\lib\src\aws-cpp-sdk-core\include\smithy\client\schema\JsonTraits.h(24,46): warning C4275: non dll-interface class 'smithy::schema::TraitKeyBase' used as base for dll-interface class 'smithy::schema::TraitKey<smithy::schema::JsonNameTrait>' [C:\Jws\qix-pc3-build-ws\build\aws-sdk-cpp\out\x64\src\aws-cpp-sdk-core\aws-cpp-sdk-core.vcxproj]
09:53:34    (compiling source file '../../../../lib/src/aws-cpp-sdk-core/source/smithy/client/schema/TraitKey.cpp')
09:53:34        C:\Jws\qix-pc3-build-ws\build\aws-sdk-cpp\lib\src\aws-cpp-sdk-core\include\smithy\client\schema\TraitKey.h(7,18):
09:53:34        see declaration of 'smithy::schema::TraitKeyBase'
09:53:34        C:\Jws\qix-pc3-build-ws\build\aws-sdk-cpp\lib\src\aws-cpp-sdk-core\include\smithy\client\schema\JsonTraits.h(24,46):
09:53:34        see declaration of 'smithy::schema::TraitKey<smithy::schema::JsonNameTrait>'

Regression Issue

• Select this option if this issue appears to be a regression.

Expected Behavior

It compiled in 1.11.817

Current Behavior

Build with:

-DCMAKE_MSVC_RUNTIME_LIBRARY=MultiThreaded$<$<CONFIG:Debug>:Debug>
-DBUILD_ONLY=s3;s3-crt
-DBUILD_SHARED_LIBS=OFF
-DCPP_STANDARD=17
-DCUSTOM_MEMORY_MANAGEMENT=ON
-DENABLE_TESTING=OFF
-DFORCE_SHARED_CRT=OFF
-DAWS_STATIC_MSVC_RUNTIME_LIBRARY=ON

And you get the compilation error.

Reproduction Steps

See above.

Possible Solution

diff --git a/src/aws-cpp-sdk-core/source/smithy/client/schema/TraitKey.cpp b/src/aws-cpp-sdk-core/source/smithy/client/schema/TraitKey.cpp
index dff0c2f99..5ea4b7a27 100644
--- a/src/aws-cpp-sdk-core/source/smithy/client/schema/TraitKey.cpp
+++ b/src/aws-cpp-sdk-core/source/smithy/client/schema/TraitKey.cpp
@@ -22,7 +22,7 @@ const TraitKey<T>& TraitKey<T>::Instance() {
   return instance;
 }
 
-#ifdef _MSC_VER
+#if defined(_MSC_VER) && defined(USE_IMPORT_EXPORT)
 #define SMITHY_TEMPLATE_EXPORT __declspec(dllexport)
 #else
 #define SMITHY_TEMPLATE_EXPORT
-- 
2.49.0

Additional Information/Context

No response

AWS CPP SDK version used

1.11.895

Compiler and Version used

MSVC 19.41.34120.0

Operating System and version

Windows 11

[sbiscigl]

confirmed reproduction and pushing out a fix, thanks for bringing this to our attention!