Add cmake config module

configure.ac

@@ -45,6 +45,7 @@ AM_INIT_AUTOMAKE([-Wall -Werror dist-bzip2 subdir-objects])
 AC_CONFIG_HEADERS([config.h])
 AC_CONFIG_SRCDIR([config.h.in])
 AC_CONFIG_MACRO_DIR([m4])
+AC_PROG_SED
 PKG_PROG_PKG_CONFIG
 PKG_INSTALLDIR()
 

lib/EtherCATConfig.cmake.in

@@ -0,0 +1,49 @@
+#----------------------------------------------------------------------------
+#
+#  Copyright (C) 2021 Bjarne von Horn, Ingenieurgemeinschaft IgH
+#
+#  This file is part of the IgH EtherCAT Master.
+#
+#  The IgH EtherCAT Master is free software; you can redistribute it and/or
+#  modify it under the terms of the GNU General Public License version 2, as
+#  published by the Free Software Foundation.
+#
+#  The IgH EtherCAT Master is distributed in the hope that it will be useful,
+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General
+#  Public License for more details.
+#
+#  You should have received a copy of the GNU General Public License along
+#  with the IgH EtherCAT Master; if not, write to the Free Software
+#  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+#
+#  ---
+#
+#  The license mentioned above concerns the source code only. Using the
+#  EtherCAT technology and brand is only permitted in compliance with the
+#  industrial property and similar rights of Beckhoff Automation GmbH.
+#
+#  vim: tw=78
+#
+#----------------------------------------------------------------------------
+
+
+find_library(EtherCAT_LIBRARY
+    NAMES EtherCAT
+    PATHS %libdir%
+)
+
+find_path(EtherCAT_INCLUDE_DIR
+    NAMES ecrt.h
+    PATHS %includedir%
+)
+
+mark_as_advanced(EtherCAT_LIBRARY EtherCAT_INCLUDE_DIR)
+
+if(NOT TARGET EtherLab::EtherCAT)
+    add_library(EtherLab::EtherCAT SHARED IMPORTED)
+    set_target_properties(EtherLab::EtherCAT PROPERTIES
+        INTERFACE_INCLUDE_DIRECTORIES "${EtherCAT_INCLUDE_DIR}"
+        IMPORTED_LOCATION "${EtherCAT_LIBRARY}"
+    )
+endif()

lib/Makefile.am

@@ -75,6 +75,10 @@ libethercat_la_LDFLAGS = -version-info 2:0:1
 
 pkgconfig_DATA = libethercat.pc
 
+cmakedir = $(libdir)/cmake
+
+cmake_DATA = EtherCATConfig.cmake
+
 #------------------------------------------------------------------------------
 
 if ENABLE_RTDM
@@ -98,3 +102,8 @@ endif
 endif
 
 #------------------------------------------------------------------------------
+
+# we need to replace the variables manually, because autotools does not expand them.
+
+EtherCATConfig.cmake: $(srcdir)/EtherCATConfig.cmake.in Makefile
+	$(SED) -e 's,%libdir%,$(libdir),' -e 's,%includedir%,$(includedir),' $< > $@