daml/dev-env/lib/dade-common

# -*- shell-script -*-
# Common development environment definitions
#

# Check if DADE_DEBUG is set. In cases when outside shell has set -u,
# and DADE_DEBUG is not set, then -z "${DADE_DEBUG}" would fail.
# This form ensures that it is not the case
if [[ -n "${DADE_DEBUG+x}" ]]; then
    set -x
fi

DADE_CURRENT_SCRIPT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
DADE_BASE_ROOT="$( cd "${DADE_CURRENT_SCRIPT_DIR}/../../" && pwd)"

errcho() {
  >&2 echo "[dev-env] $@"
}

readAbsolutePath() {
  perl -MCwd -e 'print Cwd::abs_path shift' $1
}

# Detect if we are being used within another working tree and bail out.
OLD_PWD="$PWD"
while [ "$PWD" != "/" ]; do
  if [ -h "$PWD" ]; then # follow symlink if PWD is one
    cd $(readAbsolutePath "$PWD")
  fi
  if [[ -e dev-env/lib/dade-common && "$PWD" != "$DADE_BASE_ROOT" ]]; then
    errcho "Fatal: Using dev-env from $DADE_BASE_ROOT, but running under $PWD."
    errcho "Please source the right dev-env profile:"
    errcho "  bash: 'source $PWD/dev-env/profile_bash.sh'"
    errcho "  zsh:  'source $PWD/dev-env/profile_zsh.sh'"

    exit 1
  fi
  cd ..
done
cd "$OLD_PWD"

export DADE_REPO_ROOT="${DADE_REPO_ROOT:-$DADE_BASE_ROOT}"
export DADE_DEVENV_DIR="${DADE_BASE_ROOT}/dev-env"
export DADE_LIB_DIR="${DADE_DEVENV_DIR}/lib"
# If specified, use the outer layer, e.g. dev-env bootstrap script in another
# repository, special var director.
export DADE_VAR_DIR="${DADE_VAR_DIR:-$DADE_DEVENV_DIR/var}"
# DADE_GC_ROOTS_ROOT is used by the CI builds on shared nfs
DADE_GC_ROOTS="${DADE_GC_ROOTS_ROOT:-}${DADE_VAR_DIR}/gc-roots"

# Make sure that Nix is available
source "${DADE_CURRENT_SCRIPT_DIR}/ensure-nix"

# Compute expected dade base hash
dadeBaseHash() {
    nix-hash "$DADE_DEVENV_DIR/../nix"
}

# List tools defined in dade
dadeListTools() {
    cat $(nix-build $DADE_BASE_ROOT/nix -A dade.tools-list)
}

# dadeGetOutput get output of a target
#
#   target: Attribute in the $DADE_BASE_ROOT/nix/default.nix tools attrset to
#     realize.
#   outputName: the output name of the Nix derivation, where the derivation is
#     relalized into. This is necessary, since Nix's --add-root produces a
#     unpredictable symlink name.
dadeGetOutput() {
    local target=$1
    local outputName=$2
    local output="$target"
    if [[ "$outputName" != "out" ]]; then
        output="${output}-${outputName}"
    fi
    echo $output
}

# buildTool <attribute> <outputName> <force>
#
#   attribute: Attribute in the $DADE_BASE_ROOT/nix/default.nix tools attrset to
#     realize.
#   outputName: the output name of the Nix derivation, where the derivation is
#     relalized into. This is necessary, since Nix's --add-root produces a
#     unpredictable symlink name.
#   force: if set to 1, forces re-initialization of the tool.
#   target: the output location (defaults to "$DADE_GC_ROOTS/$attribute").
buildTool() {
  local attribute=$1
  local outputName=$2
  local force=$3
  shift 3
  if [[ $# -gt 0 ]]; then
      local target=$1
      local customTarget=1
      shift 1
  else
      local target="$DADE_GC_ROOTS/$attribute"
      local customTarget=0
  fi
  local hashfile="${target}.hash"
  local hash="nope"
  local currentHash="$(dadeBaseHash)"
  local forced=""
  test -e "$hashfile" && hash="$(cat "$hashfile")"

  # Build the tool if no the garbage collector root exists or if the
  # hash of the definitions is different.
  # We depend on the behavior of nix-build to name a gc root as target-foo, for
  # a non-out output.
  DADE_BUILD_RESULT="$(dadeGetOutput $target $outputName)"
  if [[ ! -e "$DADE_BUILD_RESULT" || "$force" -eq 1 || "$hash" != "$currentHash" ]]; then
    set -e
    test "$force" -eq 1 && forced=" (forced)"
    errcho "Building tools.${attribute}${forced}..."
    # Allow to fail, so we can capture outpath and to capture the exit code too.
    set +e
    outpath=$(nix-build "${DADE_BASE_ROOT}/nix/default.nix" -A "tools.${attribute}" -Q -o "${target}")
    local dade_build_exit_code=$?
    set -e
    if [[ "$dade_build_exit_code" != "0" ]]; then
      errcho "Build of tools.$attribute has failed!"
      exit 1
    fi
    errcho "Built tools.$attribute in $outpath and linked to $DADE_BUILD_RESULT"
    if [[ $customTarget -eq 0 ]]; then
        printf "$currentHash" >| "$hashfile"
    fi
    set +e
  fi
}

# execTool <attribute> <outputName> <binary>
execTool() {
  local attribute=$1
  local outputName=$2
  local binary=$3
  shift 3
  [[ $PATH =~ (^|.*:)$DADE_DEVENV_DIR/bin($|:.*) ]] || \
    eval "$(${DADE_DEVENV_DIR}/bin/dade assist)"
  buildTool $attribute $outputName 0
  exec "$(readlink "$DADE_BUILD_RESULT")/bin/$binary" "$@"
}

# linkTool <attribute> <outputName> <target>
linkTool() {
  local attribute=$1
  local outputName=$2
  local target=$3
  shift 3
  buildTool $attribute $outputName 1 $target
}