CMake: Add cmake module to find libepoll-shim library

Author: sedmicha

CMakeModules/FindLibEpollShim.cmake

@@ -0,0 +1,40 @@
+#  LIBEPOLLSHIM_FOUND - System has libepoll-shim
+#  LIBEPOLLSHIM_INCLUDE_DIRS - The libepoll-shim include directories
+#  LIBEPOLLSHIM_LIBRARIES - The libraries needed to use libepoll-shim
+#  LIBEPOLLSHIM_DEFINITIONS - Compiler switches required for using libepoll-shim
+
+# use pkg-config to get the directories and then use these values
+# in the find_path() and find_library() calls
+find_package(PkgConfig)
+if (PKG_CONFIG_FOUND)
+    pkg_check_modules(PC_EPOLLSHIM QUIET epoll-shim)
+    set(LIBEPOLLSHIM_DEFINITIONS ${PC_EPOLLSHIM_CFLAGS_OTHER})
+endif()
+
+find_path(
+    EPOLLSHIM_INCLUDE_DIR libepoll-shim/sys/epoll.h
+    HINTS ${PC_EPOLLSHIM_INCLUDEDIR} ${PC_EPOLLSHIM_INCLUDE_DIRS}
+    PATH_SUFFIXES include
+)
+find_library(
+    EPOLLSHIM_LIBRARY NAMES epoll-shim libepoll-shim
+    HINTS ${PC_EPOLLSHIM_LIBDIR} ${PC_EPOLLSHIM_LIBRARY_DIRS}
+    PATH_SUFFIXES lib lib64
+)
+
+if (PC_EPOLLSHIM_VERSION)
+    # Version extracted from pkg-config
+    set(EPOLLSHIM_VERSION_STRING ${PC_EPOLLSHIM_VERSION})
+endif()
+
+# handle the QUIETLY and REQUIRED arguments and set LIBEPOLLSHIM_FOUND to TRUE
+# if all listed variables are TRUE
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(LibEpollShim
+    REQUIRED_VARS EPOLLSHIM_LIBRARY EPOLLSHIM_INCLUDE_DIR
+    VERSION_VAR EPOLLSHIM_VERSION_STRING
+)
+
+set(LIBEPOLLSHIM_LIBRARIES ${EPOLLSHIM_LIBRARY})
+set(LIBEPOLLSHIM_INCLUDE_DIRS ${EPOLLSHIM_INCLUDE_DIR}/libepoll-shim)
+mark_as_advanced(EPOLLSHIM_INCLUDE_DIR EPOLLSHIM_LIBRARY)