python: Provide support to select a valid python version.

- Update imports after wrapping the code.
- Fix python3 issues.
- Fix config path issues for in repo and install runs.

Closes #3537

rtemstoolkit/python-wrapper.sh

@@ -0,0 +1,54 @@
+#
+# RTEMS Tools Project (http://www.rtems.org/)
+# Copyright 2018 Chris Johns (chrisj@rtems.org)
+# All rights reserved.
+#
+# This file is part of the RTEMS Tools package in 'rtems-tools'.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are met:
+#
+# 1. Redistributions of source code must retain the above copyright notice,
+# this list of conditions and the following disclaimer.
+#
+# 2. Redistributions in binary form must reproduce the above copyright notice,
+# this list of conditions and the following disclaimer in the documentation
+# and/or other materials provided with the distribution.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+# POSSIBILITY OF SUCH DAMAGE.
+#
+
+#
+# This script wraps python finding a suitable version to use.
+#
+set -e
+if test ! -f $PYTHON_CMD; then
+  echo "error: RTEMS Toolkit python command not found: $PYTHON_CMD"
+  exit 5
+fi
+for py in python3 python2 python
+do
+  set +e
+  py_cmd=$(command -v $py)
+  set -e
+  if test -n "$RTEMS_PYTHON_OVERRIDE"; then
+    if test "$RTEMS_PYTHON_OVERRIDE" != "$py"; then
+      py_cmd=""
+    fi
+  fi
+  if test -n "$py_cmd"; then
+    exec $py_cmd $PYTHON_CMD $0 $*
+  fi
+done
+echo "error: RTEMS Toolkit no valid python found"
+exit 5