Fix Travis clang-format check

.travis-build.sh

@@ -9,23 +9,37 @@ if grep -nr '\s$' src *.yml *.txt *.md Doxyfile .gitignore .gitmodules .travis*
     exit 1
 fi
 
-for f in $(git diff --name-only --diff-filter=ACMRTUXB --cached); do
-    if ! echo "$f" | egrep -q "[.](cpp|h)$"; then
-        continue
+# Only run clang-format on Linux because we don't have 4.0 on OS X images
+if [ "$TRAVIS_OS_NAME" = "linux" ]; then
+    # Default clang-format points to default 3.5 version one
+    CLANG_FORMAT=clang-format-4.0
+    $CLANG_FORMAT --version
+
+    if [ "$TRAVIS_EVENT_TYPE" = "pull_request" ]; then
+        # Get list of every file modified in this pull request
+        files_to_lint="$(git diff --name-only --diff-filter=ACMRTUXB $TRAVIS_COMMIT_RANGE | grep '^src/[^.]*[.]\(cpp\|h\)$')"
+    else
+        # Check everything for branch pushes
+        files_to_lint="$(find src/ -name '*.cpp' -or -name '*.h')"
     fi
-    if ! echo "$f" | egrep -q "^src/"; then
-        continue
-    fi
-    d=$(diff -u "$f" <(clang-format "$f"))
+
+    # Turn off tracing for this because it's too verbose
+    set +x
+
+    for f in $files_to_lint; do
+        d=$(diff -u "$f" <($CLANG_FORMAT "$f"))
         if ! [ -z "$d" ]; then
             echo "!!! $f not compliant to coding style, here is the fix:"
             echo "$d"
             fail=1
         fi
-done
+    done
 
-if [ "$fail" = 1 ]; then
+    set -x
+
+    if [ "$fail" = 1 ]; then
         exit 1
+    fi
 fi
 
 #if OS is linux or is not set

.travis.yml

@@ -17,6 +17,7 @@ addons:
   apt:
     sources:
       - ubuntu-toolchain-r-test
+      - llvm-toolchain-precise
     packages:
       - gcc-6
       - g++-6
@@ -25,6 +26,7 @@ addons:
       - xorg-dev
       - lib32stdc++6 # For CMake
       - lftp # To upload builds
+      - clang-format-4.0
 
 cache:
   directories: