Feature/travis ccache (#2817)

* enable?

* nop

* nop

* something different

* [BUILD] add directory cache

* merge env

* nop

* nop

* [BUILD] check for contrib

* test

* nop

* remove contrib cache?

* ups

* actually use clang?

* nop

* [BUILD] try again

should work, see travis-ci/travis-ci#4393

* try on hot cache

* getting tired of this

* getting tired of this

* forget it

* debug build for clang

* gcc6 ?

* final cleanup

* final cleanup

.travis.yml

@@ -3,7 +3,16 @@ sudo: false
 language: cpp
 os:
  - linux
-cache: apt
+
+cache:
+  - apt
+  - ccache
+  - directories:
+    - contrib/
+
+env:
+  globale:
+    - CCACHE_TEMPDIR=/tmp/.ccache-temp
 addons:
    apt:
       sources:
@@ -61,19 +70,19 @@ matrix:
       os: linux
       compiler: gcc
 
-## gcc tests class and TOPP tests (if we run into a time limit, we can split it)
-## PP Wavelet is turned off due to unstable behavior ... 
+## see for example https://github.com/taocpp/PEGTL/blob/master/.travis.yml
+## gcc tests class and TOPP tests
     - env: ENABLE_STYLE_TESTING=OFF ENABLE_TOPP_TESTING=ON ENABLE_CLASS_TESTING=ON WITH_GUI=ON ADDRESS_SANITIZER=Off BUILD_TYPE=Release
       os: linux
       compiler: gcc
 
 ## clang tests class and TOPP tests: without gui and without address sanitizer (debug build)
-    - env: ENABLE_STYLE_TESTING=OFF WITH_GUI=OFF ENABLE_TOPP_TESTING=ON ENABLE_CLASS_TESTING=ON ADDRESS_SANITIZER=Off BUILD_TYPE=Debug
+    - env: ENABLE_STYLE_TESTING=OFF WITH_GUI=OFF ENABLE_TOPP_TESTING=ON ENABLE_CLASS_TESTING=ON ADDRESS_SANITIZER=Off BUILD_TYPE=Debug CXX_FLAGS="-Qunused-arguments" CFLAGS="-Qunused-arguments" CCACHE_CPP2=1
       os: linux
       compiler: clang
 
 ## clang tests class and TOPP tests: without gui and without address sanitizer (release build)
-    - env: ENABLE_STYLE_TESTING=OFF WITH_GUI=ON ENABLE_TOPP_TESTING=ON ENABLE_CLASS_TESTING=ON ADDRESS_SANITIZER=Off BUILD_TYPE=Release
+    - env: ENABLE_STYLE_TESTING=OFF WITH_GUI=ON ENABLE_TOPP_TESTING=ON ENABLE_CLASS_TESTING=ON ADDRESS_SANITIZER=Off BUILD_TYPE=Release CXX_FLAGS="-Qunused-arguments" CFLAGS="-Qunused-arguments" CCACHE_CPP2=1
       os: linux
       compiler: clang
 
@@ -82,4 +91,3 @@ matrix:
 #      os: osx
 #      compiler: clang
 #
-

tools/travis/lnx-cibuild.before.sh

@@ -34,6 +34,7 @@ build_contrib SQLITE
 # leave contrib
 popd
 
+
 # build custom cppcheck if we want to perform style tests
 if [ "${ENABLE_STYLE_TESTING}" = "ON" ]; then
   git clone git://github.com/danmar/cppcheck.git