scripts: gen-doc: enforce python virtual environment

System tools for sphinx etc tend to be behind the versions available
via pip. Prefer the pip version and automatically enable the Python
virtual environment when starting the script.

Signed-off-by: Liam Girdwood <liam.r.girdwood@intel.com>

Author: lgirdwood

scripts/gen-doc.sh

@@ -6,8 +6,25 @@
 # According to instructions:
 # https://thesofproject.github.io/latest/howtos/process/docbuild.html
 
-# fail immediately on any errors
-set -e
+# this needs to run from the Zephyr python virtual environment
+# so that the python packages are available (and more up to date than
+# the system packages).
+
+# check if Zephyr environment is set up
+if [ ! -z "$ZEPHYR_BASE" ]; then
+    VENV_DIR="$ZEPHYR_BASE/.venv"
+    echo "Using Zephyr environment at $ZEPHYR_BASE"
+elif [ ! -z "$SOF_WORKSPACE" ]; then
+    VENV_DIR="$SOF_WORKSPACE/zephyr/.venv"
+    echo "Using SOF/Zephyr environment at $SOF_WORKSPACE"
+else
+    # fallback to the zephyr default from the getting started guide
+    VENV_DIR="$HOME/zephyrproject/.venv"
+    echo "Using default Zephyr environment at $VENV_DIR"
+fi
+
+# start the virtual environment
+source ${VENV_DIR}/bin/activate
 
 function print_usage()
 {
@@ -133,3 +150,6 @@ then
 	cd "$DOCS_REPO"
 	make publish
 fi
+
+# cleanup
+deactivate