Configure Scala and C++ code formatting

Based on the scripts and configuration used by Scala Native.

Author: jonas

.clang-format

@@ -0,0 +1,7 @@
+---
+# Documentation: https://clang.llvm.org/docs/ClangFormatStyleOptions.html
+BasedOnStyle: LLVM
+IndentWidth: 4
+---
+Language: Cpp
+...

.gitignore

@@ -1 +1,3 @@
 target/
+scripts/.coursier
+scripts/.scalafmt-*

.scalafmt.conf

@@ -0,0 +1,8 @@
+style = defaultWithAlign
+docstrings = JavaDoc
+assumeStandardLibraryStripMargin = true
+project.excludeFilters = [
+  tests/samples
+]
+project.git = true
+runner.dialect = Scala211

.travis.yml

@@ -5,6 +5,10 @@ compiler: gcc
 script:
  - docker-compose build $TEST_ENV
  - docker-compose run $TEST_ENV
+ - if [[ "$TEST_ENV" = *llvm-5.0 ]]; then
+     docker-compose run --rm $TEST_ENV script/scalafmt --test;
+     docker-compose run --rm $TEST_ENV script/clangfmt --test;
+   fi
 
 matrix:
   include:

CONTRIBUTING.md

@@ -32,6 +32,22 @@ sbt ~test
 
 ## Coding Guidelines
 
+Code should be formatted with `./scripts/scalafmt` and `./scripts/clangfmt`.
+Make sure that all of your contributions are properly formatted before
+suggesting any changes. You can check the formatting using either:
+
+```sh
+script/scalafmt --test
+script/clangfmt --test
+```
+
+or:
+
+```sh
+docker-compose run --rm ubuntu-18.04-llvm-6.0 script/scalafmt --test
+docker-compose run --rm ubuntu-18.04-llvm-6.0 script/clangfmt --test
+```
+
 The C++ tool is built on Clang and Libtooling and should respect the conventions of
 LLVM and Clang tools. The code itself should adhere to the [LLVM Coding Standards],
 specifically:
@@ -40,4 +56,4 @@ specifically:
  - [Use `\n` instead of `std::endl`](https://llvm.org/docs/CodingStandards.html#avoid-std-endl)
    and remember to flush when reporting errors.
 
- [LLVM Coding Standards]: https://llvm.org/docs/CodingStandards.html
+ [LLVM Coding Standards]: https://llvm.org/docs/CodingStandards.html

Dockerfile

@@ -7,7 +7,7 @@ RUN set -x \
  && echo "deb https://dl.bintray.com/sbt/debian /" > /etc/apt/sources.list.d/sbt.list \
  && apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv 2EE0EA64E40A89B84B2DF73499E82A75642AC823 \
  && apt update \
- && apt install -y curl build-essential openjdk-8-jdk-headless sbt cmake make \
+ && apt install -y curl build-essential openjdk-8-jdk-headless sbt cmake make clang-format-5.0 \
  && rm -rf /var/lib/apt/lists/*
 
 ARG LLVM_VERSION=6.0

scripts/clangfmt

@@ -0,0 +1,74 @@
+#!/bin/bash
+#
+# Format C/C++ code using clang-format.
+#
+# To ensure reproducible formatting the script checks that clang-format
+# is from the most recent version of LLVM supported by Scala Native.
+#
+# Usage: $0 [--test]
+#
+# Set CLANG_FORMAT_PATH to configure path to clang-format.
+
+set -euo pipefail
+IFS=$'\n\t'
+
+# The required version of clang-format.
+CLANG_FORMAT_VERSION=5.0
+CLANG_FORMAT_VERSION_STRING="clang-format version $CLANG_FORMAT_VERSION"
+
+die() {
+  while [ "$#" -gt 0 ]; do
+    echo >&2 "$1"; shift
+  done
+  exit 1
+}
+
+check_clang_format_version() {
+  cmd="$1"
+  [ -e "$(type -P "$cmd")" ] && \
+    "$cmd" --version 2> /dev/null | grep -q "$CLANG_FORMAT_VERSION_STRING"
+}
+
+clang_format=
+
+if [ -n "${CLANG_FORMAT_PATH:-}" ]; then
+  check_clang_format_version "$CLANG_FORMAT_PATH" || \
+    die "CLANG_FORMAT_PATH does not have required version $CLANG_FORMAT_VERSION" \
+        "CLANG_FORMAT_PATH points to $CLANG_FORMAT_PATH"
+  clang_format="$CLANG_FORMAT_PATH"
+else
+  for cmd in "clang-format-$CLANG_FORMAT_VERSION" clang-format; do
+    if check_clang_format_version "$cmd"; then
+      clang_format="$cmd"
+      break
+    fi
+  done
+fi
+
+if [ -z "$clang_format" ]; then
+  die "clang-format version $CLANG_FORMAT_VERSION not found" \
+      "Install LLVM version $CLANG_FORMAT_VERSION and rerun."
+fi
+
+test_mode=
+
+while [ "$#" -gt 0 ]; do
+  arg="$1"
+  case "$arg" in
+    --test) test_mode=true; shift ;;
+    --*)    die "Unknown argument: $arg" "Usage: $0 [--test]" ;;
+    *)      break ;;
+  esac
+done
+
+if [ "$#" -gt 0 ]; then
+  "$clang_format" --style=file -i "$@"
+else
+  find . -name "*.[ch]" -or -name "*.cpp" | xargs "$clang_format" --style=file -i
+fi
+
+if [ "$test_mode" = true ]; then
+  git diff --quiet --exit-code || \
+    die "C/C++ code formatting changes detected" \
+        "Run \`$0\` to reformat."
+fi

scripts/scalafmt

@@ -0,0 +1,20 @@
+#!/usr/bin/env bash
+
+# set -x
+
+HERE="`dirname $0`"
+VERSION="1.2.0"
+COURSIER="$HERE/.coursier"
+SCALAFMT="$HERE/.scalafmt-$VERSION"
+
+if [ ! -f $COURSIER ]; then
+  curl -L -o $COURSIER https://git.io/vgvpD
+  chmod +x $COURSIER
+fi
+
+if [ ! -f $SCALAFMT ]; then
+  $COURSIER bootstrap com.geirsson:scalafmt-cli_2.11:$VERSION --main org.scalafmt.cli.Cli -o $SCALAFMT
+  chmod +x $SCALAFMT
+fi
+
+$SCALAFMT "$@"