bazelros

#!/usr/bin/env bash

# NOTE: this build script is meant to be used EXACTLY the same as bazel. All it
# does is allows us to control the manually built ROS part with using the Bazel
# build system

# WHY NOT JUST USE BAZEL AS IS:
# TL;DR answer: ROS really doesn't play well with Bazel at all
# More details: Bazel REALLY doesn't like the idea of introducing output file
# lists that aren't determined at analysis time, or running an arbitrary check
# script to see what needs to be rebuilt; so this was the lesser of evils
# including having a build that isn't guaranteed to always work, integrating
# ROS's catkin_make with bazel (ew...), or figuring out why using the local ROS
# install as a "local_repository" causes SEGFAULTS

# Settings
REQUIRED_PACKAGE_LIST="ros/required_packages"
BUILT_PACKAGES_FILENAME="built_packages"

BAZEL="bazel"
ROS_BUILD_TARGET="//ros:build"

function is_ros_built() {
  built="$1"
  required="$2"
  [ -f "$built" ] && cmp --silent "$required" "$built"
}

# Bazel.... you've worn me down... I don't like this but you make it so
# difficult to do simple things (i.e. write a setup where the location of the
# Isaac SDK can vary between machines...)
if [ -z "$ISAAC_SDK_PATH" ]; then
  echo "ISAAC_SDK_PATH must be set for the simulator to link to Isaac SDK."
  echo "Please set the environment variable, & rerun the script. Exiting"
  exit 1
fi
sed -i "s|\(local_repository(name = \"com_nvidia_isaac\", path = \"\).*\(\")\)|\1${ISAAC_SDK_PATH}\2|" WORKSPACE

# Build ROS if we need (probably doesn't need to be Bazel anymore... but we
# came so far just for Bazel not to want to play ball)
built_package_list="$(bazel info | grep '^bazel-genfiles:' | awk '{print $2}')/ros/$BUILT_PACKAGES_FILENAME"
if ! is_ros_built "$built_package_list" "$REQUIRED_PACKAGE_LIST"; then 
  echo "ROS_BUILD_OUTDATED: the required & built package lists do not match:"
  echo -e "\t./${REQUIRED_PACKAGE_LIST}"
  echo -e "\t${built_package_list}"
  echo -e "\nROS_BUILD_OUTDATED: Using bazel to rebuild ROS packages...\n"
  "$BAZEL" build "$ROS_BUILD_TARGET" --action_env=BENCHBOT_MSGS_HASH="${BENCHBOT_MSGS_HASH:-}"
  if ! is_ros_built "$built_package_list" "$REQUIRED_PACKAGE_LIST"; then
    echo -e "\nROS_BUILD_OUTDATED: required & built package lists still do not match"
    echo "ROS_BUILD_OUTDATED: Building of ROS failed. Exiting"
    exit 1
  fi
fi

# Run Bazel exactly like normal with all of the arguments passed in
echo -e "\nROS_BUILD_VALID: ROS build is up to date. Moving on...\n"
"$BAZEL" "$@"