Generate a fresh Travis config file using the haskell-ci script

Summary:
The old Travis script still had targets to test against GHC < 8.0,
and wasn't using Cabal `new-build` among other things.

Reviewers: bgamari, RyanGlScott

Reviewed By: RyanGlScott

Differential Revision: https://phabricator.haskell.org/D4681

.gitignore

+cabal.project.local
+cabal.project.local~
+
 # Specific generated files
 GNUmakefile
 dist-install/
 dist/
+dist-newstyle/
+.ghc.environment.*
 ghc.mk

.travis.yml

-env:
- - GHCVER=7.8.4
- - GHCVER=7.10.3
- - GHCVER=8.0.2
- - GHCVER=8.2.1
- - GHCVER=head
+# This Travis job script has been generated by a script via
+#
+#   runghc make_travis_yml_2.hs 'array.cabal'
+#
+# For more information, see https://github.com/hvr/multi-ghc-travis
+#
+language: c
+sudo: false
+
+git:
+  submodules: false  # whether to recursively clone submodules
+
+cache:
+  directories:
+    - $HOME/.cabal/packages
+    - $HOME/.cabal/store
+
+before_cache:
+  - rm -fv $HOME/.cabal/packages/hackage.haskell.org/build-reports.log
+  # remove files that are regenerated by 'cabal update'
+  - rm -fv $HOME/.cabal/packages/hackage.haskell.org/00-index.*
+  - rm -fv $HOME/.cabal/packages/hackage.haskell.org/*.json
+  - rm -fv $HOME/.cabal/packages/hackage.haskell.org/01-index.cache
+  - rm -fv $HOME/.cabal/packages/hackage.haskell.org/01-index.tar
+  - rm -fv $HOME/.cabal/packages/hackage.haskell.org/01-index.tar.idx
+
+  - rm -rfv $HOME/.cabal/packages/head.hackage
 
 matrix:
+  include:
+    - compiler: "ghc-8.0.2"
+    # env: TEST=--disable-tests BENCH=--disable-benchmarks
+      addons: {apt: {packages: [ghc-ppa-tools,cabal-install-head,ghc-8.0.2], sources: [hvr-ghc]}}
+    - compiler: "ghc-8.2.1"
+    # env: TEST=--disable-tests BENCH=--disable-benchmarks
+      addons: {apt: {packages: [ghc-ppa-tools,cabal-install-head,ghc-8.2.1], sources: [hvr-ghc]}}
+    - compiler: "ghc-8.4.2"
+    # env: TEST=--disable-tests BENCH=--disable-benchmarks
+      addons: {apt: {packages: [ghc-ppa-tools,cabal-install-head,ghc-8.4.2], sources: [hvr-ghc]}}
+    - compiler: "ghc-head"
+      addons: {apt: {packages: [ghc-ppa-tools,cabal-install-head,ghc-head], sources: [hvr-ghc]}}
+
   allow_failures:
-   - env: GHCVER=head
+    - compiler: "ghc-head"
 
 before_install:
- - sudo add-apt-repository -y ppa:hvr/ghc
- - sudo apt-get update
- - sudo apt-get install cabal-install-head ghc-$GHCVER
- - export PATH=/opt/ghc/bin:$PATH
+  - HC=${CC}
+  - HCPKG=${HC/ghc/ghc-pkg}
+  - unset CC
+  - ROOTDIR=$(pwd)
+  - mkdir -p $HOME/.local/bin
+  - "PATH=/opt/ghc/bin:/opt/ghc-ppa-tools/bin:$HOME/local/bin:$PATH"
+  - HCNUMVER=$(( $(${HC} --numeric-version|sed -E 's/([0-9]+)\.([0-9]+)\.([0-9]+).*/\1 * 10000 + \2 * 100 + \3/') ))
+  - echo $HCNUMVER
 
 install:
- - cabal update
- - ghc --version
+  - cabal --version
+  - echo "$(${HC} --version) [$(${HC} --print-project-git-commit-id 2> /dev/null || echo '?')]"
+  - BENCH=${BENCH---enable-benchmarks}
+  - TEST=${TEST---enable-tests}
+  - HADDOCK=${HADDOCK-true}
+  - INSTALLED=${INSTALLED-true}
+  - GHCHEAD=${GHCHEAD-false}
+  - travis_retry cabal update -v
+  - "sed -i.bak 's/^jobs:/-- jobs:/' ${HOME}/.cabal/config"
+  - rm -fv cabal.project cabal.project.local
+  - grep -Ev -- '^\s*--' ${HOME}/.cabal/config | grep -Ev '^\s*$'
+  - "printf 'packages: \".\"\\n' > cabal.project"
+  - cat cabal.project
+  - if [ -f "./configure.ac" ]; then
+      (cd "." && autoreconf -i);
+    fi
+  - rm -f cabal.project.freeze
+  - cabal new-build -w ${HC} ${TEST} ${BENCH} --project-file="cabal.project" --dep -j2 all
+  - cabal new-build -w ${HC} --disable-tests --disable-benchmarks --project-file="cabal.project" --dep -j2 all
+  - rm -rf .ghc.environment.* "."/dist
+  - DISTDIR=$(mktemp -d /tmp/dist-test.XXXX)
 
+# Here starts the actual work to be performed for the package under test;
+# any command which exits with a non-zero exit code causes the build to fail.
 script:
- - cabal configure -v2
- - cabal build
- - cabal check
- - cabal sdist
- - export SRC_TGZ=$(cabal info . | awk '{print $2 ".tar.gz";exit}') ;
-   cd dist/;
-   if [ -f "$SRC_TGZ" ]; then
-      cabal install "$SRC_TGZ";
-   else
-      echo "expected '$SRC_TGZ' not found";
-      exit 1;
-   fi
+  # test that source-distributions can be generated
+  - (cd "." && cabal sdist)
+  - mv "."/dist/array-*.tar.gz ${DISTDIR}/
+  - cd ${DISTDIR} || false
+  - find . -maxdepth 1 -name '*.tar.gz' -exec tar -xvf '{}' \;
+  - "printf 'packages: array-*/*.cabal\\n' > cabal.project"
+  - cat cabal.project
+  # this builds all libraries and executables (without tests/benchmarks)
+  - cabal new-build -w ${HC} --disable-tests --disable-benchmarks all
+
+  # # Build with installed constraints for packages in global-db
+  # - if $INSTALLED; then echo cabal new-build -w ${HC} --disable-tests --disable-benchmarks $(${HCPKG} list --global --simple-output --names-only | sed 's/\([a-zA-Z0-9-]\{1,\}\) */--constraint="\1 installed" /g') all | sh; else echo "Not building with installed constraints"; fi
+
+  # build & run tests, build benchmarks
+  - cabal new-build -w ${HC} ${TEST} ${BENCH} all
+
+  # cabal check
+  - (cd array-* && cabal check)
+
+  # haddock
+  - rm -rf ./dist-newstyle
+  - if $HADDOCK; then cabal new-haddock -w ${HC} ${TEST} ${BENCH} all; else echo "Skipping haddock generation";fi
+
+# REGENDATA ["array.cabal"]
+# EOF

array.cabal

@@ -9,7 +9,7 @@ synopsis:      Mutable and immutable arrays
 category:      Data Structures
 build-type:    Simple
 cabal-version: >=1.10
-tested-with:   GHC==8.4.1, GHC==8.2.1, GHC==8.0.2
+tested-with:   GHC==8.4.2, GHC==8.2.1, GHC==8.0.2
 description:
     In addition to providing the "Data.Array" module
     <http://www.haskell.org/onlinereport/haskell2010/haskellch14.html as specified in the Haskell 2010 Language Report>,