scripts/cog/resources/fx

#!/bin/bash
# Copyright 2026 The Fuchsia Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

readonly GIT_CITC_PATH="$(which git-citc)"
readonly COG_FUCHSIA_DIR="$(readlink -f "$(dirname "${BASH_SOURCE[0]}")/../..")"
readonly CARTFS_FUCHSIA_DIR="${COG_FUCHSIA_DIR}/cartfs-dir/fuchsia"

set -e

if [[ ! -e "${CARTFS_FUCHSIA_DIR}" ]]; then
  echo "Error: unable to find the cartfs symlink. Run the setup script to fix this."
  exit 1
fi

# Compute the base commit hash
base_commit_hash=$("${GIT_CITC_PATH}" api.get-repo-states fuchsia | grep base_commit_hash | awk '{print $2}' | tr -d '"')
base_commit_hash_in_cartfs=$(cd "${CARTFS_FUCHSIA_DIR}" && git rev-parse HEAD)

# if the base commit hash is different from the one in CartFS, then we need to
# update the CartFS.
if [[ "${base_commit_hash}" != "${base_commit_hash_in_cartfs}" ]]; then
  echo "Updating CartFS to base commit hash ${base_commit_hash}..."
  "${COG_FUCHSIA_DIR}/scripts/cog/setup_cog_workspace.py"
fi

diff_output=$("${GIT_CITC_PATH}" cli.diff "${base_commit_hash}" @)

# Copy over any added or modified files to the CartFS.
added_or_modified_files=$(echo "${diff_output}" | grep '^\[[AM]\]' | awk '{print $2}')
for file in ${added_or_modified_files[@]}; do
  sha256_cog=$(sha256sum "${COG_FUCHSIA_DIR}/${file}" | awk '{print $1}')
  sha256_cartfs=""
  if [[ -f "${CARTFS_FUCHSIA_DIR}/${file}" ]]; then
    sha256_cartfs=$(sha256sum "${CARTFS_FUCHSIA_DIR}/${file}" | awk '{print $1}')
  fi
  if [[ "${sha256_cog}" != "${sha256_cartfs}" ]]; then
    cp "${COG_FUCHSIA_DIR}/${file}" "${CARTFS_FUCHSIA_DIR}/${file}"
  fi
done

# Delete files in CartFS
deleted_files=$(echo "${diff_output}" | grep '^\[D\]' | awk '{print $2}')
for file in ${deleted_files[@]}; do
  if [[ -f "${CARTFS_FUCHSIA_DIR}/${file}" ]]; then
    rm "${CARTFS_FUCHSIA_DIR}/${file}"
  fi
done

command="$1"
if [[ "$command" =~ ^(set|build|test|add-test|add-host-test|set-main-pb|args)$ ]]; then
  # We need to run this here to make sure that the PATH is updated with the
  # prebuilts in the CartFS. If we do not do this then we will pick up the wrong
  # hermetic-env.
  source "${CARTFS_FUCHSIA_DIR}/scripts/fx-env.sh" && fx-update-path
  (
    cd "${CARTFS_FUCHSIA_DIR}"
    exec "${CARTFS_FUCHSIA_DIR}/scripts/fx" "$@"
  )
else
  exec "${COG_FUCHSIA_DIR}/scripts/fx" "$@"
fi