cmake: add imported target for Libtorrent

cmake/Modules/FindLibtorrentRasterbar.cmake

@@ -91,3 +91,15 @@ find_package_handle_standard_args(LibtorrentRasterbar DEFAULT_MSG
 mark_as_advanced(LibtorrentRasterbar_INCLUDE_DIR LibtorrentRasterbar_LIBRARY
     LibtorrentRasterbar_ORIG_CMAKE_FIND_LIBRARY_SUFFIXES
     LibtorrentRasterbar_ENCRYPTION_INDEX)
+
+if (LibtorrentRasterbar_FOUND AND NOT TARGET LibtorrentRasterbar::LibTorrent)
+    add_library(LibtorrentRasterbar::LibTorrent UNKNOWN IMPORTED)
+
+    set_target_properties(LibtorrentRasterbar::LibTorrent PROPERTIES
+        IMPORTED_LINK_INTERFACE_LANGUAGES "CXX"
+        IMPORTED_LOCATION "${LibtorrentRasterbar_LIBRARY}"
+        INTERFACE_INCLUDE_DIRECTORIES "${LibtorrentRasterbar_INCLUDE_DIRS}"
+        INTERFACE_LINK_LIBRARIES "${LibtorrentRasterbar_LIBRARIES}"
+        INTERFACE_COMPILE_OPTIONS "${LibtorrentRasterbar_DEFINITIONS}"
+    )
+endif()

src/CMakeLists.txt

@@ -6,8 +6,6 @@ include(MacroLinkQtComponents)
 include(QbtTargetSources)
 
 find_package(LibtorrentRasterbar REQUIRED)
-include_directories(SYSTEM ${LibtorrentRasterbar_INCLUDE_DIRS})
-add_compile_options(${LibtorrentRasterbar_DEFINITIONS})
 
 # Boost
 set(Boost_USE_MULTITHREADED ON)

src/base/CMakeLists.txt

@@ -113,7 +113,7 @@ tristatebool.cpp
 )
 
 add_library(qbt_base STATIC ${QBT_BASE_HEADERS} ${QBT_BASE_SOURCES})
-target_link_libraries(qbt_base ${ZLIB_LIBRARIES} ${LibtorrentRasterbar_LIBRARIES})
+target_link_libraries(qbt_base ${ZLIB_LIBRARIES} LibtorrentRasterbar::LibTorrent)
 target_link_qt_components(qbt_base Core Network Xml)
 if (QT4_FOUND)
     if (GUI)