feat: Ensure correct shared library exports and build configuration. (#105)

Author: kinyoklion

CMakeLists.txt

@@ -56,15 +56,14 @@ set(OPENSSL_ROOT_DIR "/opt/homebrew/opt/[email protected]")
 find_package(OpenSSL REQUIRED)
 message(STATUS "LaunchDarkly: using OpenSSL v${OPENSSL_VERSION}")
 
-if (MSVC)
-    set(Boost_USE_STATIC_LIBS ON)
-else ()
-    if (BUILD_SHARED_LIBS)
-        set(Boost_USE_STATIC_LIBS OFF)
-    else ()
-        set(Boost_USE_STATIC_LIBS ON)
-    endif ()
-endif ()
+set(Boost_USE_STATIC_LIBS ON)
+
+if(BUILD_SHARED_LIBS)
+    # When building a shared library we hide all symbols
+    # aside from this we have specifically exported for the C-API.
+    set(CMAKE_CXX_VISIBILITY_PRESET hidden)
+    set(CMAKE_VISIBILITY_INLINES_HIDDEN 1)
+endif()
 
 set(Boost_USE_MULTITHREADED ON)
 set(Boost_USE_STATIC_RUNTIME OFF)

libs/client-sdk/src/CMakeLists.txt

@@ -43,10 +43,23 @@ add_library(${LIBNAME}
         flag_manager/flag_persistence.cpp
         bindings/c/sdk.cpp)
 
-target_link_libraries(${LIBNAME}
+if(MSVC OR (NOT BUILD_SHARED_LIBS))
+        target_link_libraries(${LIBNAME}
+                PUBLIC launchdarkly::common
+                PRIVATE Boost::headers Boost::json Boost::url launchdarkly::sse launchdarkly::internal foxy)
+else()
+        # The default static lib builds, for linux, are positition independent.
+        # So they do not link into a shared object without issues. So, when
+        # building shared objects do not link the static libraries and instead
+        # use the "src.hpp" files for required libraries.
+        # macOS shares the same path for simplicity.
+        target_link_libraries(${LIBNAME}
         PUBLIC launchdarkly::common
         PRIVATE Boost::headers launchdarkly::sse launchdarkly::internal foxy)
 
+        target_sources(${LIBNAME} PRIVATE boost.cpp)
+endif ()
+
 add_library(launchdarkly::client ALIAS ${LIBNAME})
 
 

libs/client-sdk/src/boost.cpp

@@ -0,0 +1,5 @@
+// This file is used to include boost url/json when building a shared library on linux/mac.
+// Windows links static libs in this case and does not include these src files, as there
+// are issues compiling the value.ipp file from JSON with MSVC.
+#include <boost/url/src.hpp>
+#include <boost/json/src.hpp>

libs/client-sdk/src/client.cpp

@@ -9,7 +9,7 @@ Client::Client(Config config, Context context)
                                           std::move(context),
                                           kVersion)) {}
 bool Client::Initialized() const {
-    return false;
+    return client->Initialized();
 }
 
 using FlagKey = std::string;

libs/server-sent-events/src/CMakeLists.txt

@@ -11,6 +11,7 @@ add_library(${LIBNAME} OBJECT
         parser.cpp
         event.cpp
         backoff.cpp)
+
 target_link_libraries(${LIBNAME}
         PUBLIC OpenSSL::SSL Boost::headers foxy
         PRIVATE Boost::url Boost::disable_autolinking