Rewrite Travis file

- build on more compilers
  • GCC 7, 8, and 9 on Linux
  • clang 6, 7, and 8 on Linux
  • xcode 9.4 and 10.2 on macOS
- update to xenial
- remove all workarounds/special cases
- don't pull in/update all of homebrew on macOS builds (this was quite slow)

.travis.yml

@@ -1,76 +1,110 @@
+dist: xenial
 sudo: required
 language: cpp
-dist: trusty
+os: linux
 
 matrix:
   include:
 
-  - os: linux
-    addons: &gcc5
-        apt:
-          packages:
-            - g++-5
-          sources:
-            - ubuntu-toolchain-r-test
-
-  - os: linux
-    addons: &gcc6
-        apt:
-          packages:
-            - g++-6
-          sources:
-            - ubuntu-toolchain-r-test
+  #####
+  ## Clang on macOS
+  #####
 
+  # xcode 9.4
   - os: osx
-    osx_image: xcode9.2
-    compiler: clang
-    
+    osx_image: xcode9.4
+
+  # xcode 10.2
   - os: osx
-    osx_image: xcode8.3
-    compiler: clang
+    osx_image: xcode10.2
+
+  #####
+  ## Clang on Linux
+  #####
+
+  # clang 6
+  - addons:
+      apt:
+        sources:
+          - ubuntu-toolchain-r-test
+          - llvm-toolchain-xenial-6
+        packages:
+          - clang-6.0
+          - uuid-dev
+    env:
+      - SET_COMPILERS="CC=clang-6.0 && CXX=clang++-6.0"
+
+  # clang 7
+  - addons:
+      apt:
+        sources:
+          - ubuntu-toolchain-r-test
+          - llvm-toolchain-xenial-7
+        packages:
+          - clang-7
+          - uuid-dev
+    env:
+      - SET_COMPILERS="CC=clang-7 && CXX=clang++-7"
+
+  # clang 8
+  - addons:
+      apt:
+        sources:
+          - ubuntu-toolchain-r-test
+          - llvm-toolchain-xenial-8
+        packages:
+          - clang-8
+          - uuid-dev
+    env:
+      - SET_COMPILERS="CC=clang-8 && CXX=clang++-8"
+
+  #####
+  ## GCC on Linux
+  #####
+
+  # gcc 7
+  - addons:
+      apt:
+        sources:
+          - ubuntu-toolchain-r-test
+        packages:
+          - g++-7
+          - uuid-dev
+    env:
+      - SET_COMPILERS="CC=gcc-7 && CXX=g++-7"
+
+  # gcc 8
+  - addons:
+      apt:
+        sources:
+          - ubuntu-toolchain-r-test
+        packages:
+          - g++-8
+          - uuid-dev
+    env:
+      - SET_COMPILERS="CC=gcc-8 && CXX=g++-8"
+
+  # gcc 9
+  - addons:
+      apt:
+        sources:
+          - ubuntu-toolchain-r-test
+        packages:
+          - g++-9
+          - uuid-dev
+    env:
+      - SET_COMPILERS="CC=gcc-9 && CXX=g++-9"
 
 before_install:
-   # Workaround for Travis CI macOS bug (https://github.com/travis-ci/travis-ci/issues/6307)
-   # See https://github.com/searchivarius/nmslib/pull/259
-  - |
-    if [ "${TRAVIS_OS_NAME}" == "osx" ]; then
-        command curl -sSL https://rvm.io/mpapis.asc | gpg --import -;
-        rvm get head || true
-    fi
-  
-script:
-  - export CHECKOUT_PATH=`pwd`;
-  - echo "ROOT_PATH= $ROOT_PATH"
-  - echo "CHECKOUT_PATH= $CHECKOUT_PATH"
+  # We have to do this here instead of just setting the env vars in the matrix
+  # because the compilers need to override the default setup
+  - eval "${SET_COMPILERS}"
 
-  #######################################################################################
-  # Install a recent CMake (unless already installed on OS X)
-  #######################################################################################
-  - |
-    if [[ "${TRAVIS_OS_NAME}" == "linux" ]]; then
-      CMAKE_URL="http://www.cmake.org/files/v3.10/cmake-3.10.2-Linux-x86_64.tar.gz"
-      mkdir cmake && travis_retry wget --no-check-certificate --quiet -O - ${CMAKE_URL} | tar --strip-components=1 -xz -C cmake
-      export PATH=${DEPS_DIR}/cmake/bin:${PATH}
-    else
-      brew upgrade cmake || echo "suppress failures in order to ignore warnings"
-      brew link --overwrite cmake
-    fi
-  - cmake --version
+before_script:
+  - cd "${TRAVIS_BUILD_DIR}"
+  - mkdir build && cd build
+  - cmake .. -DCMAKE_BUILD_TYPE="Debug"
 
-  - | 
-    if [[ "${TRAVIS_OS_NAME}" == "linux" ]]; then
-      sudo apt-get install uuid-dev
-    fi
-  #######################################################################################
-  # Build the library
-  #######################################################################################
-  - |
-    cd "${CHECKOUT_PATH}"
-    mkdir build
-    cd build
-    cmake .. -DCMAKE_BUILD_TYPE="Debug"
-    sudo make install
-  #######################################################################################
-  # Run the tests
-  #######################################################################################
+script:
+  - cmake --build . -- -j${JOBS} && sudo make install
   - ./crossguid-test