1 files changed, 30 insertions, 15 deletions
diff --git a/presubmit.sh b/presubmit.sh
index 0d356f1..227ce92 100755
--- a/presubmit.sh
+++ b/presubmit.sh
@@ -5,11 +5,14 @@
 readonly local_path=$(dirname "$0")
 source "${local_path}/utils/utils.sh"
 
-readonly shellcheck_version=" 0.3.3"
+readonly shellcheck_path="${local_path}/shellcheck/shellcheck"
+readonly shellcheck_url="https://git.linaro.org/people/kevin.brodsky/shellcheck-prebuilt.git/plain/shellcheck"
 
 # Globally excluded shellcheck "checks"
-# SC2102 - https://github.com/koalaman/shellcheck/issues/682
-readonly shellcheck_exclude_list="SC2102"
+# SC1090: shellcheck can't source files whose path is determined at runtime
+#         (we almost always use ${local_path} when sourcing)
+# SC2155: almost never an actual problem
+readonly shellcheck_exclude_list="SC1090,SC2155"
 
 declare -a shell_files
 
@@ -20,23 +23,35 @@ find_shell_files() {
   readonly shell_files
 }
 
-# Run shellcheck on all the .sh files.
-shellcheck_tests() {
-  if ! exists shellcheck; then
-    log E "No \"shellcheck\" available in your path. apt-get install shellcheck ?"
-    log E "You can also find shellcheck here: https://github.com/koalaman/shellcheck ."
-    log E "Please note that the scripts have only been tested with version ${shellcheck_version}."
-    return 1
+# Fetch shellcheck from our own prebuilt shellcheck repo.
+fetch_shellcheck() {
+  # We use a sha1 checksum to know whether we need to download a newer version.
+  local -r remote_sha1=$(safe curl -s "${shellcheck_url}.sha1")
+  local -r sha1_regex='[0-9a-f]+\s+shellcheck'
+  if ! [[ ${remote_sha1} =~ $sha1_regex ]]; then
+    log E "Invalid remote sha1: ${remote_sha1}"
+    abort
   fi
 
-  local current_shellcheck_version=$(shellcheck -V | grep -i "version:")
-  if [[ ! ${current_shellcheck_version} =~ ${shellcheck_version} ]]; then
-    log W "The scripts have only been tested with shellcheck version ${shellcheck_version}."
-    log W "Things might fail!"
+  if [[ -e "${shellcheck_path}" && -e "${shellcheck_path}.sha1" && \
+        $(< "${shellcheck_path}.sha1") == "${remote_sha1}" ]]; then
+    # We already have the latest shellcheck
+    return
   fi
 
+  # Download the latest shellcheck
+  mkdir -p "$(dirname "${shellcheck_path}")"
+  log I "Downloading shellcheck to ${shellcheck_path}"
+  safe curl -s -o "${shellcheck_path}" "${shellcheck_url}"
+  chmod +x "${shellcheck_path}"
+  # Update the sha1
+  echo "${remote_sha1}" > "${shellcheck_path}.sha1"
+}
 
-  shellcheck -e "${shellcheck_exclude_list}" "${shell_files[@]}"
+# Run shellcheck on all the .sh files.
+shellcheck_tests() {
+  fetch_shellcheck
+  "${shellcheck_path}" --color -e "${shellcheck_exclude_list}" "${shell_files[@]}"
 }
 
 # Check for invalid constructions regarding read-only variables and the local