Extract API versioN

Author: CodaFi

.travis.yml

@@ -16,20 +16,20 @@ matrix:
       sudo: required
       dist: trusty
       env:
-        - LLVM_CONFIG=llvm-config-3.9
+        - LLVM_API_VERSION=3.9
       before_install:
         # Set the package config path so we can see cllvm
         - export PKG_CONFIG_PATH=/usr/local/lib/pkgconfig:"${PKG_CONFIG_PATH}"
         # Pull clang and llvm
         - wget -O - http://apt.llvm.org/llvm-snapshot.gpg.key | sudo apt-key add -
         - sudo apt-add-repository "deb http://apt.llvm.org/trusty/ llvm-toolchain-trusty-3.9 main"
         - sudo apt-get update
-        - sudo apt-get install llvm-3.9 clang-3.9
+        - sudo apt-get install llvm-${LLVM_API_VERSION}
         # Work around pre-installed clang
         - sudo rm -rf /usr/local/clang-*/bin/llvm-config
         - ls -l /usr/bin/llvm-config*
         - sudo rm -f /usr/bin/llvm-config
-        - sudo ln -s /usr/bin/llvm-config-3.9 /usr/bin/llvm-config
+        - sudo ln -s /usr/bin/llvm-config-${LLVM_API_VERSION} /usr/bin/llvm-config
         # Grab Swift
         - wget -q -O - https://swift.org/keys/all-keys.asc | gpg --import -
         - wget https://swift.org/builds/swift-3.0.2-release/ubuntu1404/swift-3.0.2-RELEASE/swift-3.0.2-RELEASE-ubuntu14.04.tar.gz