ci: update ccache and improve its support

Update ccache to 3.2.5
Set ccache size
Display ccache statistics for each build
Disable ccache for configure phase
Export ccache bin path
travis: remove ccache stats before saving cache

.travis.yml

@@ -45,6 +45,9 @@ script:
   - python Tools/autotest/param_metadata/param_parse.py
   - Tools/scripts/build_ci.sh
 
+before_cache:
+  - ccache -z
+
 notifications:
   webhooks:
     urls:

Tools/scripts/build_ci.sh

@@ -28,6 +28,12 @@ if [ -z "$CI_BUILD_TARGET" ]; then
     CI_BUILD_TARGET="sitl linux px4-v2"
 fi
 
+if [[ "$CI_BUILD_TARGET" == *"px4"* ]]; then
+    export CCACHE_MAXSIZE="1500M"
+else
+    export CCACHE_MAXSIZE="500M"
+fi
+
 # special case for SITL testing in CI
 if [ "$CI_BUILD_TARGET" = "sitltest" ]; then
     echo "Installing pymavlink"
@@ -64,6 +70,7 @@ for t in $CI_BUILD_TARGET; do
             fi
 
             make $t -j2
+            ccache -s && ccache -z
             popd
         done
 
@@ -86,6 +93,8 @@ for t in $CI_BUILD_TARGET; do
         $waf configure --board $t --enable-benchmarks --check-c-compiler="$c_compiler" --check-cxx-compiler="$cxx_compiler"
         $waf clean
         $waf -j2 all
+        ccache -s && ccache -z
+
         if [[ $t == linux ]]; then
             $waf check
         fi

Tools/scripts/configure-ci.sh

@@ -3,13 +3,16 @@
 
 set -ex
 
+# Disable ccache for the configure phase, it's not worth it
+export CCACHE_DISABLE="true"
+
 ARM_ROOT="gcc-arm-none-eabi-4_9-2015q3"
 ARM_TARBALL="$ARM_ROOT-20150921-linux.tar.bz2"
 
 RPI_ROOT="master"
 RPI_TARBALL="$RPI_ROOT.tar.gz"
 
-CCACHE_ROOT="ccache-3.2.4"
+CCACHE_ROOT="ccache-3.2.5"
 CCACHE_TARBALL="$CCACHE_ROOT.tar.bz2"
 
 mkdir -p $HOME/opt
@@ -68,6 +71,7 @@ exportline="export PATH=$HOME/ccache"
 exportline="${exportline}:$HOME/bin"
 exportline="${exportline}:$HOME/opt/gcc-arm-none-eabi-4_9-2015q3/bin"
 exportline="${exportline}:$HOME/opt/tools-master/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian-x64/bin"
+exportline="${exportline}:$HOME/opt/$CCACHE_ROOT"
 exportline="${exportline}:\$PATH"
 
 if grep -Fxq "$exportline" ~/.profile; then