Revert "Drop epoll dependency"

This reverts commit 91f2bf81bf.

CMake/FindEpollShim.cmake

@@ -0,0 +1,17 @@
+# - Find EpollShim
+# Once done, this will define
+#
+#   EPOLLSHIM_FOUND - System has EpollShim
+#   EPOLLSHIM_INCLUDE_DIRS - The EpollShim include directories
+#   EPOLLSHIM_LIBRARIES - The libraries needed to use EpollShim
+
+find_path(EPOLLSHIM_INCLUDE_DIRS NAMES sys/epoll.h sys/timerfd.h HINTS /usr/local/include/libepoll-shim)
+find_library(EPOLLSHIM_LIBRARIES NAMES epoll-shim libepoll-shim HINTS /usr/local/lib)
+
+if (EPOLLSHIM_INCLUDE_DIRS AND EPOLLSHIM_LIBRARIES)
+	set(EPOLLSHIM_FOUND TRUE)
+endif (EPOLLSHIM_INCLUDE_DIRS AND EPOLLSHIM_LIBRARIES)
+
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(EPOLLSHIM DEFAULT_MSG EPOLLSHIM_LIBRARIES EPOLLSHIM_INCLUDE_DIRS)
+mark_as_advanced(EPOLLSHIM_INCLUDE_DIRS EPOLLSHIM_LIBRARIES)

CMakeLists.txt

@@ -68,6 +68,10 @@ find_package(PAM)
 find_package(LibInput REQUIRED)
 find_package(Libcap REQUIRED)
 
+if (CMAKE_SYSTEM_NAME STREQUAL FreeBSD)
+	find_package(EpollShim REQUIRED)
+endif (CMAKE_SYSTEM_NAME STREQUAL FreeBSD)
+
 include(FeatureSummary)
 include(Manpage)
 include(GNUInstallDirs)