check coding style in travis

.travis.yml

@@ -15,6 +15,15 @@ matrix:
     - env: TRAVIS_EMPTY_JOB_WORKAROUND=true
 
   include:
+    # check coding style
+    - env: CASE=codingstyle
+      addons:
+        apt:
+          sources:
+            - llvm-toolchain-precise-3.7
+            - ubuntu-toolchain-r-test
+          packages:
+            - clang-format-3.7
     # check typical OGS builds
     - env: CASE=FEM
     - env: CASE=IPQC
@@ -44,8 +53,9 @@ install:
   - if [[ "$CASE" == "PETSC" ]]; then travis_retry sudo apt-get install -qq libpetsc3.4.2-dev; fi
 
 script:
-  - mkdir build && cd build && cmake -DOGS_CONFIG=${CASE} $CMAKE_ARGS -DOGS_CPU_ARCHITECTURE=generic .. && cmake ..
-  - make
+  - if [[ "$CASE" != "codingstyle" ]]; then mkdir build && cd build && cmake -DOGS_CONFIG=${CASE} $CMAKE_ARGS -DOGS_CPU_ARCHITECTURE=generic .. && cmake ..; fi
+  - if [[ "$CASE" != "codingstyle" ]]; then make; fi
+  - if [[ "$CASE" == "codingstyle" ]]; then chmod +x ./scripts/ci/check_code_format.sh && ./scripts/ci/check_code_format.sh; fi
 
 notifications:
   email:

scripts/ci/check_code_format.sh

@@ -0,0 +1,30 @@
+#!/bin/bash
+#
+# Modified from https://github.com/google/closure-library/tree/master/scripts/ci
+#
+# Script to determine if files in Pull Request are properly formatted.
+# Exits with non 0 exit code if formatting is needed.
+
+CLANG_FORMAT_DIFF=clang-format-diff-3.7
+
+FILES_TO_CHECK=$(git diff --name-only master | grep -E "\.h|\.cpp$")
+
+if [ -z "${FILES_TO_CHECK}" ]; then
+  echo "No files to check for formatting."
+  exit 0
+fi
+
+FORMAT_DIFF=$(git diff -U0 master -- ${FILES_TO_CHECK} |
+              ${CLANG_FORMAT_DIFF} -p1 -style=file)
+
+if [ -z "${FORMAT_DIFF}" ]; then
+  # No formatting necessary.
+  echo "All files in PR properly formatted."
+  exit 0
+else
+  # Found diffs.
+  echo "ERROR: Found formatting errors!"
+  echo "${FORMAT_DIFF}"
+  echo "See https://goo.gl/wUEkW9 for instructions to format your PR."
+  exit 1
+fi