no_atomic.sh

#!/bin/bash
set -euo pipefail
IFS=$'\n\t'
cd "$(dirname "$0")"/..

# Update the list of targets that do not support atomic/CAS operations.
#
# Usage:
#    ./ci/no_atomic.sh

file=no_atomic.rs

# `"max-atomic-width" == 0` means that atomic is not supported at all.
# We do not have a cfg for targets with {8,16}-bit atomic only, so
# for now we treat them the same as targets that do not support atomic.
# It is not clear exactly what `"max-atomic-width" == null` means, but they
# actually seem to have the same max-atomic-width as the target-pointer-width.
# The targets currently included in this group are "mipsel-sony-psp",
# "thumbv4t-none-eabi", "thumbv6m-none-eabi", all of which are
# `"target-pointer-width" == "32"`, so assuming them `"max-atomic-width" == 32`
# for now.
no_atomic=$(RUSTC_BOOTSTRAP=1 rustc +stable -Z unstable-options --print all-target-specs-json | jq -r '. | to_entries[] | select((.value."max-atomic-width" == 0) or (.value."min-atomic-width" and .value."min-atomic-width" != 8)) | "    \"" + .key + "\","')

cat >"${file}" <<EOF
// This file is @generated by ${0##*/}.
// It is not intended for manual editing.

const NO_ATOMIC: &[&str] = &[
${no_atomic}
];
EOF