Fix building unit tests targetting windows

Fixes MSVC's LNK4217 warnings and MinGW errors.

.circleci/config.yml

@@ -54,6 +54,9 @@ jobs:
             ../cmake/build_win32.sh
             make lmms
             make
+      - run:
+          name: Build tests
+          command: cd build && make tests
       - *ccache_stats
       - *save_cache
   mingw64:
@@ -71,6 +74,9 @@ jobs:
             mkdir build && cd build
             ../cmake/build_win64.sh
             make
+      - run:
+          name: Build tests
+          command: cd build && make tests
       - *ccache_stats
       - *save_cache
   linux.gcc:

.travis/script.sh

@@ -24,12 +24,10 @@ else
 	"$TRAVIS_BUILD_DIR/.travis/$TRAVIS_OS_NAME.$TARGET_OS.script.sh"
 
 	make -j4
+	make tests
 
 	if [[ $TARGET_OS != win* ]]; then
-
-		make tests
 		tests/tests
-
 	fi
 
 	# Package and upload non-tagged builds

src/CMakeLists.txt

@@ -116,12 +116,15 @@ TARGET_INCLUDE_DIRECTORIES(lmms
 	PUBLIC ${CMAKE_CURRENT_BINARY_DIR}
 )
 
-# GENERATE_EXPORT_HEADER doesn't do this automatically for OBJECT libraries
+# CMake doesn't define target_EXPORTS for OBJECT libraries.
+# See the documentation of DEFINE_SYMBOL for details.
+# Also add LMMS_STATIC_DEFINE for targets linking against it.
 TARGET_COMPILE_DEFINITIONS(lmmsobjs
 	PRIVATE -Dlmmsobjs_EXPORTS
+	INTERFACE -DLMMS_STATIC_DEFINE
 )
 TARGET_COMPILE_DEFINITIONS(lmms
-	PRIVATE -Dlmmsobjs_EXPORTS
+	PRIVATE $<TARGET_PROPERTY:lmmsobjs,INTERFACE_COMPILE_DEFINITIONS>
 )
 
 # Set Visual Studio startup project to lmms
@@ -389,4 +392,4 @@ ELSE(NOT MSVC)
 		#				"${VCPKG_ROOT}/bin/libsoundio.dll"
 		#			DESTINATION .)
 		#ENDIF()
-ENDIF(NOT MSVC)
+ENDIF(NOT MSVC)

tests/CMakeLists.txt

@@ -19,5 +19,8 @@ ADD_EXECUTABLE(tests
 
 	src/tracks/AutomationTrackTest.cpp
 )
+TARGET_COMPILE_DEFINITIONS(tests
+	PRIVATE $<TARGET_PROPERTY:lmmsobjs,INTERFACE_COMPILE_DEFINITIONS>
+)
 TARGET_LINK_LIBRARIES(tests ${QT_LIBRARIES} ${QT_QTTEST_LIBRARY})
 TARGET_LINK_LIBRARIES(tests ${LMMS_REQUIRED_LIBS})