#! /usr/bin/env bash
## vim:set ts=4 sw=4 et:
set -e; set -o pipefail
argv0=$0; argv0abs="$(readlink -fn "$argv0")"; argv0dir="$(dirname "$argv0abs")"

# run an interactive shell in the image
# using a rootless Podman container

image=upx-cross-compile-20230115-v2

flags=( -ti --read-only --rm )
flags+=( --cap-drop=all )               # drop all capabilities
flags+=( --network=none )               # no network needed
flags+=( -e TERM="$TERM" )              # pass $TERM
if [[ 1 == 1 ]]; then
    # run as user upx 2000:2000
    flags+=( --user 2000 )
    # map container users 0..999 to subuid-users 1..1000, and map container user 2000 to current host user
    flags+=( --uidmap=0:1:1000 --uidmap=2000:0:1 )
    # map container groups 0..999 to subgid-groups 1..1000, and map container group 2000 to current host group
    flags+=( --gidmap=0:1:1000 --gidmap=2000:0:1 )
    # NOTE: we mount the upx top-level directory read-write under /home/upx/src/upx
    # INFO: SELinux users *may* have to add ":z" to the volume mount flags; check the docs!
    flags+=( -v "${argv0dir}/../..:/home/upx/src/upx" )
    flags+=( -w /home/upx/src/upx )     # set working directory
else
    # run as user root 0:0
    # ONLY FOR DEBUGGING THE IMAGE
    # map container user/group 0 to current host user/group
    flags+=( --user 0 )
fi

podman run "${flags[@]}" "$image" bash -l

# now we can cross-compile UPX for Windows:
#   cd /home/upx/src/upx
#   rm -rf ./build/extra/cross-windows-mingw64/release
#   make build/extra/cross-windows-mingw64/release

# and we can run the clang Static Analyzer (scan-build)
#   cd /home/upx/src/upx
#   rm -rf ./build/extra/scan-build/release
#   make build/extra/scan-build/release

# and lots of other cross-compilers are installed; see "ls /usr/bin/*g++*"

# and finally see misc/cross-compile-upx-with-podman/build-all-inside-container.sh
# after running that script we can do cool things like:
#   cd /home/upx/src/upx/build/cross-compile-upx-with-podman/alpha-linux-gnu/debug
#   qemu-alpha -L /usr/alpha-linux-gnu upx --version
#   cd /home/upx/src/upx/build/cross-compile-upx-with-podman/hppa-linux-gnu/debug
#   qemu-hppa -L /usr/hppa-linux-gnu upx --version
# (similar for many other architectures/builds)
