Arm backend: Check generated documentation edits before pushing (pytorch#23049)

Run docgen when a commit changes generated documentation. Rebuild the
pages from their templates and compare them with the committed versions.

This catches edits made only to generated pages in the original patch,
before they cause failures for later changes.

Include deleted files in the trigger check and reject untracked outputs
recreated by docgen, since git diff does not report them.

Signed-off-by: Sebastian Larsson <sebastian.larsson@arm.com>

Author: Sebastian-Larsson

backends/arm/scripts/pre-push

@@ -41,6 +41,13 @@ RUN_DOCGEN=0
 
 is_docgen_trigger_file() {
     local file_path="$1"
+    local output_path
+    for output_path in "${DOCGEN_OUTPUTS[@]}"; do
+        if [[ "$file_path" == "$output_path" ]]; then
+            return 0
+        fi
+    done
+
     case "${file_path}" in
         backends/arm/common/arm_compile_spec.py|\
         backends/arm/ethosu/*.py|\
@@ -57,21 +64,30 @@ is_docgen_trigger_file() {
 }
 
 run_docgen_check() {
-    local FAILED=0
+    local docgen_status=0
 
     echo -e "${INFO} Running Arm docgen"
     if ! python backends/arm/scripts/docgen/docgen.py; then
         echo -e "${ERROR} Failed to run Arm docgen"
-        FAILED=1
-    elif ! git diff --quiet HEAD -- "${DOCGEN_OUTPUTS[@]}"; then
+        return 1
+    fi
+
+    local untracked_outputs
+    untracked_outputs=$(git ls-files --others -- "${DOCGEN_OUTPUTS[@]}")
+    if ! git diff --quiet HEAD -- "${DOCGEN_OUTPUTS[@]}" || \
+        [[ -n "$untracked_outputs" ]]; then
         echo -e "${ERROR} Arm docgen updated generated documentation." >&2
         echo -e "${INFO} Review and commit the regenerated docs before pushing."
         git diff HEAD -- "${DOCGEN_OUTPUTS[@]}"
-        FAILED=1
+        if [[ -n "$untracked_outputs" ]]; then
+            echo -e "${INFO} Untracked generated documentation:"
+            echo "$untracked_outputs"
+        fi
+        docgen_status=1
     else
         echo -e "${SUCCESS} Arm docgen OK"
     fi
-    return "$FAILED"
+    return "$docgen_status"
 }
 
 run_op_support_checks() {
@@ -190,7 +206,7 @@ for COMMIT in ${COMMITS}; do
     fi
 
     commit_files=$(git diff-tree --no-commit-id --name-only \
-        --diff-filter=ACMR ${COMMIT} -r)
+        --diff-filter=ACDMR ${COMMIT} -r)
     if [[ $RUN_DOCGEN -eq 0 ]]; then
         for committed_file in $commit_files; do
             if is_docgen_trigger_file "${committed_file}"; then