On Tue, Mar 28, 2023 at 2:42 AM John Moon <quic_johmoo@xxxxxxxxxxx> wrote:
>
> While the kernel community has been good at maintaining backwards
> compatibility with kernel UAPIs, it would be helpful to have a tool
> to check if a commit introduces changes that break backwards
> compatibility.
>
> To that end, introduce check-uapi.sh: a simple shell script that
> checks for changes to UAPI headers using libabigail.
>
> libabigail is "a framework which aims at helping developers and
> software distributors to spot some ABI-related issues like interface
> incompatibility in ELF shared libraries by performing a static
> analysis of the ELF binaries at hand."
>
> The script uses one of libabigail's tools, "abidiff", to compile the
> changed header before and after the commit to detect any changes.
>
> abidiff "compares the ABI of two shared libraries in ELF format. It
> emits a meaningful report describing the differences between the two
> ABIs."
>
> The script also includes the ability to check the compatibility of
> all UAPI headers across commits. This allows developers to inspect
> the stability of the UAPIs over time.
>
> Signed-off-by: John Moon <quic_johmoo@xxxxxxxxxxx>
> ---
> - Refactored to exclusively check headers installed by make
> headers_install. This simplified the code dramatically and removed
> the need to perform complex git diffs.
> - Removed the "-m" flag. Since we're checking all installed headers
> every time, a flag to check only modified files didn't make sense.
> - Added info message when usr/include/Makefile is not present that
> it's likely because that file was only introduced in v5.3.
> - Changed default behavior of log file. Now, the script will not
> create a log file unless you pass "-l <file>".
> - Simplified exit handler.
> - Added -j $MAX_THREADS to make headers_install to improve speed.
> - Cleaned up variable references.
>
> scripts/check-uapi.sh | 488 ++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 488 insertions(+)
> create mode 100755 scripts/check-uapi.sh
>
> +
> +# Save the current git tree state, stashing if needed
> +save_tree_state() {
> + printf "Saving current tree state... "
> + current_ref="$(git rev-parse HEAD)"
> + readonly current_ref
> + if tree_is_dirty; then
> + unstash="true"
> + git stash push --quiet
> + fi
> + printf "OK\n"
> +}
> +
> +# Restore the git tree state, unstashing if needed
> +restore_tree_state() {
> + if [ -z "$current_ref" ]; then
> + return 0
> + fi
> +
> + printf "Restoring current tree state... "
> + git checkout --quiet "$current_ref"
This does not restore the original state.
I was on a branch before running this script.
After everything is finished, I am on a detached commit
because $current_ref is not a branch.
> + if ! do_compile "$(get_header_tree "$past_ref")/include" "$past_header" "${past_header}.bin" 2> "$log"; then
> + eprintf "error - couldn't compile version of UAPI header %s at %s\n" "$file" "$past_ref"
> + cat "$log" >&2
> + exit "$FAIL_COMPILE"
> + fi
> +
> + "$ABIDIFF" --non-reachable-types "${past_header}.bin" "${base_header}.bin" > "$log" && ret="$?" || ret="$?"
[bikeshed] I might want to write like this:
ret=0
"$ABIDIFF" --non-reachable-types "${past_header}.bin"
"${base_header}.bin" > "$log" || ret="$?"
> +
> +
> + if [ "$quiet" = "true" ]; then
> + run "$base_ref" "$past_ref" "$abi_error_log" "$@" > /dev/null
> + else
> + run "$base_ref" "$past_ref" "$abi_error_log" "$@"
> + fi
if [ "$quiet" = "true" ]; then
exec > /dev/null
fi
run "$base_ref" "$past_ref" "$abi_error_log" "$@"
is more elegant because this is the last line of main()
and exit_handler() does not print anything.
--
Best Regards
Masahiro Yamada
