```cmake
option(ENABLE_ada "Build Ada interface to PLplot" OFF)
# Eventually configure this.
set(GNATMAKE_EXECUTABLE gnatmake)
# This location can be obtained from last element in object search path
# generated by "gnatls -v" command.
# This works for Debian stable.  Eventually configure this.
set(GNAT_DIR /usr/lib/gcc-lib/i486-linux/3.3.5/adalib/)
```

Implement configuration of all things Ada.
user
```cmake
# cmake/modules/ada.cmake
#
# Copyright (C) 2007 Alan W. Irwin
#
# This file is part of PLplot.
#
# PLplot is free software; you can redistribute it and/or modify
# it under the terms of the GNU Library General Public License as published
# by the Free Software Foundation; version 2 of the License.
#
# PLplot 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 Library General Public License for more details.
#
# You should have received a copy of the GNU Library General Public License
# along with the file PLplot; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301  USA

# Module for determining Ada bindings configuration options

option(ENABLE_ada "Enable Ada bindings" OFF)

if(ENABLE_ada)
  find_program(GNATMAKE_EXECUTABLE gnatmake)
  if(NOT GNATMAKE_EXECUTABLE)
    message(STATUS "WARNING: "
      "gnatmake not found. Disabling ada bindings")
      set(ENABLE_ada OFF CACHE BOOL "Enable Ada bindings" FORCE)
  endif(NOT GNATMAKE_EXECUTABLE)
endif(ENABLE_ada)

if(ENABLE_ada)
  find_library(GNAT_LIB gnat)
  if(NOT GNAT_LIB)
    message(STATUS "WARNING: "
      "gnat library not found. Disabling ada bindings")
      set(ENABLE_ada OFF CACHE BOOL "Enable Ada bindings" FORCE)
  endif(NOT GNAT_LIB)
endif(ENABLE_ada)

if(ENABLE_ada)
  enable_language(Ada)
endif(ENABLE_ada)
```
assistant