Add support for clang to the android build scripts

platform_tools/android/bin/utils/setup_toolchain.sh

 #!/bin/bash
 #
 # setup_toolchain.sh: Sets toolchain environment variables used by other scripts.
 
 # Fail-fast if anything in the script fails.
 set -e
 
 # check that the preconditions for this script are met
 if [ $(type -t verbose) != 'function' ]; then
   echo "ERROR: The verbose function is expected to be defined"
@@ skipping 28 matching lines @@
   TOOLCHAIN_DIR=${SCRIPT_DIR}/../toolchains
   if [ $(uname) == "Darwin" ]; then
     verbose "Using Mac toolchain."
     TOOLCHAIN_TYPE=ndk-r$NDK_REV-$ANDROID_ARCH-darwin_v$API_LEVEL
   else
     verbose "Using Linux toolchain."
     TOOLCHAIN_TYPE=ndk-r$NDK_REV-$ANDROID_ARCH-linux_v$API_LEVEL
   fi
   exportVar ANDROID_TOOLCHAIN "${TOOLCHAIN_DIR}/${TOOLCHAIN_TYPE}/bin"
 
+  # Hack for NDK_REV == 10c to ensure that clang is present as it was
+  # added to the tarball after it was initially distributed.
+  if [ ! -x ${ANDROID_TOOLCHAIN}/clang ]; then
+    rm -rf ${TOOLCHAIN_DIR}/${TOOLCHAIN_TYPE}
+  fi
+
   # if the toolchain doesn't exist on your machine then we need to fetch it
   if [ ! -d "$ANDROID_TOOLCHAIN" ]; then
     mkdir -p $TOOLCHAIN_DIR
     # enter the toolchain directory then download, unpack, and remove the tarball
     pushd $TOOLCHAIN_DIR
     TARBALL=ndk-r$NDK_REV-v$API_LEVEL.tgz
 
     ${SCRIPT_DIR}/download_toolchains.py \
         http://chromium-skia-gm.commondatastorage.googleapis.com/android-toolchains/$TARBALL \
         $TOOLCHAIN_DIR/$TARBALL
     tar -xzf $TARBALL $TOOLCHAIN_TYPE
     rm $TARBALL
     popd
-  fi 
+  fi
 
-  verbose "Targeting NDK API $API_LEVEL for use on Android 4.0 (NDK Revision $NDK_REV) and above"  
+  verbose "Targeting NDK API $API_LEVEL (NDK Revision $NDK_REV)"
 }
 
 #check to see if the toolchain has been defined and if not setup the default toolchain
 if [ -z "$ANDROID_TOOLCHAIN" ]; then
   default_toolchain
   if [ ! -d "$ANDROID_TOOLCHAIN" ]; then
     echo "ERROR: unable to download/setup the required toolchain (${ANDROID_TOOLCHAIN})"
     return 1;
   fi
 fi
 
 GCC=$(command ls $ANDROID_TOOLCHAIN/*-gcc | head -n1)
 if [ -z "$GCC" ]; then
   echo "ERROR: Could not find Android cross-compiler in: $ANDROID_TOOLCHAIN"
   return 1
 fi
 
 # Remove the '-gcc' at the end to get the full toolchain prefix
 ANDROID_TOOLCHAIN_PREFIX=${GCC%%-gcc}
 
 CCACHE=${ANDROID_MAKE_CCACHE-$(which ccache || true)}
 
-exportVar CC "$CCACHE $ANDROID_TOOLCHAIN_PREFIX-gcc"
-exportVar CXX "$CCACHE $ANDROID_TOOLCHAIN_PREFIX-g++"
-exportVar LINK "$CCACHE $ANDROID_TOOLCHAIN_PREFIX-gcc"
+if [ -z $USE_CLANG ]; then
+  exportVar CC "$CCACHE $ANDROID_TOOLCHAIN_PREFIX-gcc"
+  exportVar CXX "$CCACHE $ANDROID_TOOLCHAIN_PREFIX-g++"
+  exportVar LINK "$CCACHE $ANDROID_TOOLCHAIN_PREFIX-gcc"
+else
+  # temporarily disable ccache as it is generating errors

[tomhudson, 2014/10/30 19:17:31]

Unrelated change?

[djsollen, 2014/10/30 19:21:22]

no it seems to be generating errors when we combine ccache and clang.

+  CCACHE=""
+  exportVar CC "$CCACHE $ANDROID_TOOLCHAIN_PREFIX-clang"
+  exportVar CXX "$CCACHE $ANDROID_TOOLCHAIN_PREFIX-clang++"
+  exportVar LINK "$CCACHE $ANDROID_TOOLCHAIN_PREFIX-clang"
+fi
 
 exportVar AR "$ANDROID_TOOLCHAIN_PREFIX-ar"
 exportVar RANLIB "$ANDROID_TOOLCHAIN_PREFIX-ranlib"
 exportVar OBJCOPY "$ANDROID_TOOLCHAIN_PREFIX-objcopy"
 exportVar STRIP "$ANDROID_TOOLCHAIN_PREFIX-strip"
 
 # Create symlinks for nm & readelf and add them to the path so that the ninja
 # build uses them instead of attempting to use the one on the system.
 # This is required to build using ninja on a Mac.
-ln -sf $ANDROID_TOOLCHAIN_PREFIX-nm $ANDROID_TOOLCHAIN/nm
-ln -sf $ANDROID_TOOLCHAIN_PREFIX-readelf $ANDROID_TOOLCHAIN/readelf
-ln -sf $ANDROID_TOOLCHAIN_PREFIX-as $ANDROID_TOOLCHAIN/as
+if [ $(uname) == "Darwin" ]; then
+  ln -sf $ANDROID_TOOLCHAIN_PREFIX-nm $ANDROID_TOOLCHAIN/nm
+  ln -sf $ANDROID_TOOLCHAIN_PREFIX-readelf $ANDROID_TOOLCHAIN/readelf
+  ln -sf $ANDROID_TOOLCHAIN_PREFIX-as $ANDROID_TOOLCHAIN/as
+fi
+
 exportVar PATH $ANDROID_TOOLCHAIN:$PATH