Add CPPLINT static code analysis

.travis.yml

@@ -8,6 +8,7 @@ cache: ccache
 sudo: required
 env:
   - CHECK_LICENSES=1
+  - CPPLINT=1
   - WITH_LIBDE265= WITH_GRAPHICS=
   - WITH_LIBDE265= WITH_GRAPHICS=1
   - WITH_LIBDE265=1 WITH_GRAPHICS=1
@@ -19,6 +20,8 @@ matrix:
   exclude:
     - compiler: clang
       env: CHECK_LICENSES=1
+    - compiler: clang
+      env: CPPLINT=1
     - compiler: clang
       env: EMSCRIPTEN_VERSION=1.37.26
     - compiler: clang

CPPLINT.cfg

@@ -0,0 +1,2 @@
+set noparent
+filter=-,+build/include_what_you_use

autogen.sh

@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/bin/bash
 set -eu
 #
 # HEIF codec.
@@ -19,6 +19,13 @@ set -eu
 # You should have received a copy of the GNU General Public License
 # along with libheif.  If not, see <http://www.gnu.org/licenses/>.
 #
+ROOT="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
+
+if [ -d "$ROOT/.git/hooks" ]; then
+    echo "Installing pre-commit hook ..."
+    ln -sf "$ROOT/scripts/pre-commit.hook" "$ROOT/.git/hooks/pre-commit"
+fi
+
 if [ -x "`which autoreconf 2>/dev/null`" ] ; then
    exec autoreconf -ivf
 fi

examples/encoder_jpeg.h

@@ -26,6 +26,8 @@
 
 #include <jpeglib.h>
 
+#include <string>
+
 #include "encoder.h"
 
 class JpegEncoder : public Encoder {

examples/encoder_png.h

@@ -20,6 +20,8 @@
 #ifndef EXAMPLE_ENCODER_PNG_H
 #define EXAMPLE_ENCODER_PNG_H
 
+#include <string>
+
 #include "encoder.h"
 
 class PngEncoder : public Encoder {