Add libevdev detection macro.

diff --git a/m4/libevdev.m4 b/m4/libevdev.m4
new file mode 100644 (file)
index 0000000..cc8dc39
--- /dev/null
+++ b/m4/libevdev.m4
@@ -0,0 +1,39 @@
+dnl Copyright © 2017 Nick Bowler
+dnl
+dnl License WTFPL2: Do What The Fuck You Want To Public License, version 2.
+dnl This is free software: you are free to do what the fuck you want to.
+dnl There is NO WARRANTY, to the extent permitted by law.
+
+dnl DX_LIB_LIBEVDEV
+dnl
+dnl Search for libevdev.  This library does not expose version information
+dnl so min-version checks are not supported.
+dnl
+dnl If a working library is found, appropriate compiler and linker flags are
+dnl stored in LIBEVDEV_CFLAGS and LIBEVDEV_LIBS, respectively, and the
+dnl action-if-ok is performed (may be empty).  If no such library is found,
+dnl then action-if-failed is performed if non-empty; otherwise configure will
+dnl stop with a fatal error.
+AC_DEFUN([DX_LIB_LIBEVDEV],
+[DX_LIB_SETUP([libevdev])dnl
+DX_LIB_PKGCONFIG_FLAGS([libevdev])
+AC_MSG_CHECKING([for libevdev])
+DX_LIB_SEARCH_LINK([libevdev], [_DX_LIB_LIBEVDEV_TEST],
+  [ [[$LIBEVDEV_CFLAGS], [$LIBEVDEV_LIBS]],
+    [[$dx_cv_libevdev_pkg_cflags], [$dx_cv_libevdev_pkg_libs],
+      [test x"$dx_cv_libevdev_pkg_found" = x"yes"]],
+    [[], [-levdev]] ])
+AS_IF([test x"$dx_cv_libevdev_lib_found" = x"yes"], [$1],
+  [m4_default([$2], [AC_MSG_FAILURE(
+[libevdev is required.  The latest version may be found at
+<https://www.freedesktop.org/wiki/Software/libevdev/>.
+m4_newline([DX_LIB_USERFLAG_BLURB([libevdev])])
+m4_newline([DX_LIB_PKGCONFIG_BLURB([libevdev])])
+])])])])
+
+dnl Internal test program for libevdev.
+m4_define([_DX_LIB_LIBEVDEV_TEST], [AC_LANG_PROGRAM(
+[#include <libevdev/libevdev.h>
+],
+[libevdev_free(libevdev_new());
+])])