Fixed Windows build.

* CMAKE_SHARED_LIBRARY_CXX_FLAGS is empty here, caused CMake errors.
 * CMake's OBJECT target has a bug that it doesn't define target_EXPORTS
   as with other library targets, so it's needed to define it manually.
   It also fixes empty flags issue.
 * Visibility headers weren't updated for OBJECT targets, they now also
   catch *Objects_EXPORTS defines.

src/CMakeLists.txt

@@ -30,7 +30,9 @@ set(MagnumMath_SRCS
 )
 add_library(MagnumMathObjects OBJECT ${MagnumMath_SRCS})
 
-set_target_properties(MagnumObjects MagnumMathObjects PROPERTIES COMPILE_FLAGS ${CMAKE_SHARED_LIBRARY_CXX_FLAGS})
+# Set shared library flags for the objects, as they will be part of shared lib
+# TODO: fix when CMake sets target_EXPORTS for OBJECT targets as well
+set_target_properties(MagnumObjects MagnumMathObjects PROPERTIES COMPILE_FLAGS "-DMagnumObjects_EXPORTS ${CMAKE_SHARED_LIBRARY_CXX_FLAGS}")
 
 # Files compiled with different flags for main library and unit test library
 set(Magnum_GracefulAssert_SRCS

src/MeshTools/CMakeLists.txt

@@ -3,7 +3,10 @@ set(MagnumMeshTools_SRCS
     Tipsify.cpp
 )
 add_library(MagnumMeshToolsObjects OBJECT ${MagnumMeshTools_SRCS})
-set_target_properties(MagnumMeshToolsObjects PROPERTIES COMPILE_FLAGS ${CMAKE_SHARED_LIBRARY_CXX_FLAGS})
+
+# Set shared library flags for the objects, as they will be part of shared lib
+# TODO: fix when CMake sets target_EXPORTS for OBJECT targets as well
+set_target_properties(MagnumMeshToolsObjects PROPERTIES COMPILE_FLAGS "-DMagnumMeshToolsObjects_EXPORTS ${CMAKE_SHARED_LIBRARY_CXX_FLAGS}")
 
 # Files compiled with different flags for main library and unit test library
 set(MagnumMeshTools_GracefulAssert_SRCS

src/MeshTools/visibilityMeshTools.h

@@ -16,7 +16,7 @@
 */
 
 #ifdef _WIN32
-    #ifdef MagnumMeshTools_EXPORTS
+    #if defined(MagnumMeshTools_EXPORTS) || defined(MagnumMeshToolsObjects_EXPORTS)
         #define MESHTOOLS_EXPORT __declspec(dllexport)
     #else
         #define MESHTOOLS_EXPORT __declspec(dllimport)

src/Physics/CMakeLists.txt

@@ -9,7 +9,6 @@ set(MagnumPhysics_SRCS
 )
 
 add_library(MagnumPhysics SHARED ${MagnumPhysics_SRCS})
-set_target_properties(MagnumPhysics PROPERTIES COMPILE_FLAGS ${CMAKE_SHARED_LIBRARY_CXX_FLAGS})
 
 target_link_libraries(MagnumPhysics Magnum)
 

src/Shaders/CMakeLists.txt

@@ -5,7 +5,7 @@ set(Shaders_SRCS
 )
 
 add_library(MagnumShaders SHARED ${Shaders_SRCS})
-set_target_properties(MagnumShaders PROPERTIES COMPILE_FLAGS ${CMAKE_SHARED_LIBRARY_CXX_FLAGS})
+
 target_link_libraries(MagnumShaders Magnum)
 
 install(TARGETS MagnumShaders DESTINATION ${MAGNUM_LIBRARY_INSTALL_DIR})

src/visibility.h

@@ -16,7 +16,7 @@
 */
 
 #ifdef _WIN32
-    #ifdef Magnum_EXPORTS
+    #if defined(Magnum_EXPORTS) || defined(MagnumObjects_EXPORTS)
         #define MAGNUM_EXPORT __declspec(dllexport)
     #else
         #define MAGNUM_EXPORT __declspec(dllimport)