Fix support scripts on Linux (#1385)

* Make it possible to run style.sh on Linux

Needs clang-format in a nonstandard location, but can be made to work.

* Fix lint.sh on Linux

* Fix multiline comment error

2 files changed, 42 insertions, 10 deletions

diff --git a/scripts/lint.sh b/scripts/lint.sh
index d474129..3d4f453 100755
--- a/scripts/lint.sh
+++ b/scripts/lint.sh
@@ -68,10 +68,21 @@ else
   command=(git ls-files)
 fi
 
+# POSIX xargs is required to run commands at least once, but cpplint.py fails
+# (with huge help text) if no files are supplied. Apple xargs avoids invocation
+# if there are no arguments. Use a temporary file to avoid depending on/testing
+# for this feature.
+TEMP=$(mktemp -t lint-files-$$.XXXXXXXXXX)
+trap "rm '$TEMP'" EXIT
+
 # Straight C++ files get regular cpplint
 "${command[@]}" "${git_options[@]}" \
     -- 'Firestore/core/**/*.'{h,cc} \
-  | xargs -0 python scripts/cpplint.py --quiet 2>&1
+  > "$TEMP"
+
+if [[ -s "$TEMP" ]]; then
+  xargs -0 python scripts/cpplint.py --quiet 2>&1 < "$TEMP"
+fi
 CPP_STATUS=$?
 
 # Objective-C++ files get a looser cpplint
@@ -79,7 +90,10 @@ CPP_STATUS=$?
     -- 'Firestore/Source/**/*.'{h,m,mm} \
       'Firestore/Example/Tests/**/*.'{h,m,mm} \
       'Firestore/core/**/*.mm' \
-  | xargs -0 python scripts/cpplint.py "${objc_lint_options[@]}" --quiet 2>&1
+  > "$TEMP"
+if [[ -s "$TEMP" ]]; then
+  xargs -0 python scripts/cpplint.py "${objc_lint_options[@]}" --quiet 2>&1 < "$TEMP"
+fi
 OBJC_STATUS=$?
 
 if [[ $CPP_STATUS != 0 || $OBJC_STATUS != 0 ]]; then
diff --git a/scripts/style.sh b/scripts/style.sh
index 8eff1e8..f82af77 100755
--- a/scripts/style.sh
+++ b/scripts/style.sh
@@ -21,18 +21,36 @@
 # Commonly
 # ./scripts/style.sh master
 
-system=$(uname -s)
-
+# Strip the clang-format version output down to the major version. Examples:
+#   clang-format version 7.0.0 (tags/google/stable/2018-01-11)
+#   clang-format version google3-trunk (trunk r333779)
 version=$(clang-format --version)
+
+# Remove leading "clang-format version"
 version="${version/*version /}"
+# Remove trailing parenthetical version details
+version="${version/ (*)/}"
+# Remove everything after the first dot (note this is a glob, not a regex)
 version="${version/.*/}"
-if [[ "$version" != 6 && "$version" != 7 ]]; then
-  # Allow an older clang-format to accommodate Travis version skew.
-  echo "Please upgrade to clang-format version 7."
-  echo "If it's installed via homebrew you can run: brew upgrade clang-format"
-  exit 1
-fi
 
+case "$version" in
+  6 | 7)
+    # Allow an older clang-format to accommodate Travis version skew.
+    ;;
+  google3-trunk)
+    echo "Please use a publicly released clang-format; a recent LLVM release"
+    echo "from http://releases.llvm.org/download.html will work."
+    echo "Prepend to PATH when running style.sh."
+    exit 1
+    ;;
+  *)
+    echo "Please upgrade to clang-format version 7."
+    echo "If it's installed via homebrew you can run: brew upgrade clang-format"
+    exit 1
+    ;;
+esac
+
+system=$(uname -s)
 if [[ "$system" == "Darwin" ]]; then
   version=$(swiftformat --version)
   version="${version/*version /}"