#!/bin/bash
# Computes the flags for ghcide to pass to ghci. You probably won’t be running this yourself, but rather ghcide will via configuration in hie.yaml.

set -e

cd "$(dirname "$0")/.."

ghc_version="$(ghc --numeric-version)"

# recent hie-bios requires us to output to the file at $HIE_BIOS_OUTPUT, but older builds & script/repl don’t set that var, so we default it to stdout
output_file="${HIE_BIOS_OUTPUT:-/dev/stdout}"

# do a build of dependencies up front to ensure they’re all available
cabal v2-build -v0 all --only-dependencies

build_products_dir="dist-newstyle/build/x86_64-osx/ghc-$ghc_version/build-repl"

function flags {
  # disable optimizations for faster loading
  echo "-O0"
  # don’t load .ghci files (for ghcide)
  echo "-ignore-dot-ghci"

  # where to put build products
  echo "-outputdir $build_products_dir"
  echo "-odir $build_products_dir"
  echo "-hidir $build_products_dir"
  echo "-stubdir $build_products_dir"

  # preprocessor options, for -XCPP
  echo "-optP-include"
  echo "-optP$build_products_dir/autogen/cabal_macros.h"

  # autogenerated sources, both .hs and .h (e.g. Foo_paths.hs)
  echo "-i$build_products_dir/autogen"
  echo "-I$build_products_dir/autogen"

  # .hs source dirs
  # TODO: would be nice to figure this out from cabal.project & the .cabal files
  echo "-isemantic-analysis/src"
  echo "-isemantic-ast/src"
  echo "-isemantic-core/src"
  echo "-isemantic-java/src"
  echo "-isemantic-json/src"
  echo "-isemantic-python/src"
  echo "-isemantic-tags/src"
  echo "-iapp"
  echo "-isrc"
  echo "-ibench"
  echo "-itest"

  # disable automatic selection of packages
  echo "-hide-all-packages"

  # run cabal and emit package flags from the environment file, removing comments & prefixing with -
  cabal v2-exec -v0 bash -- -c 'cat "$GHC_ENVIRONMENT"' | grep -v '^--' | sed -e 's/^/-/'

  # default language extensions
  echo "-XHaskell2010"
  echo "-XStrictData"

  # treat warnings as warnings
  echo "-Wwarn"

  # default warning flags
  echo "-Weverything"
  echo "-Wno-all-missed-specialisations"
  echo "-Wno-implicit-prelude"
  echo "-Wno-missed-specialisations"
  echo "-Wno-missing-import-lists"
  echo "-Wno-missing-local-signatures"
  echo "-Wno-monomorphism-restriction"
  echo "-Wno-name-shadowing"
  echo "-Wno-safe"
  echo "-Wno-unsafe"
  [[ "$ghc_version" = 8.6.* ]] || [[ "$ghc_version" = 8.8.* ]] && echo "-Wno-star-is-type" || true
  [[ "$ghc_version" = 8.8.* ]] && echo "-Wno-missing-deriving-strategies" || true
}

flags > "$output_file"