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References: <20231212020259.2451253-1-quic_johmoo@quicinc.com> <20231212020259.2451253-2-quic_johmoo@quicinc.com>
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From: Masahiro Yamada <masahiroy@kernel.org>
Date: Sat, 23 Dec 2023 02:50:55 +0900
Message-ID: <CAK7LNASZzeJzZV0hiMrcKd6FUtQXqfuvUqux8Bf+WvBmjCwNCA@mail.gmail.com>
Subject: Re: [PATCH v7 1/3] check-uapi: Introduce check-uapi.sh
To: John Moon <quic_johmoo@quicinc.com>
Cc: Nathan Chancellor <nathan@kernel.org>, Nick Desaulniers <ndesaulniers@google.com>, 
	Nicolas Schier <nicolas@fjasle.eu>, Jonathan Corbet <corbet@lwn.net>, linux-kbuild@vger.kernel.org, 
	linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, 
	linux-arm-msm@vger.kernel.org, kernel@quicinc.com, 
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>, Rob Herring <robh@kernel.org>, 
	"Carlos O'Donell" <carlos@redhat.com>, Randy Dunlap <rdunlap@infradead.org>, Arnd Bergmann <arnd@arndb.de>, 
	Bjorn Andersson <andersson@kernel.org>, Todd Kjos <tkjos@google.com>, 
	Matthias Maennich <maennich@google.com>, Giuliano Procida <gprocida@google.com>, kernel-team@android.com, 
	libabigail@sourceware.org, Dodji Seketeli <dodji@redhat.com>, 
	Trilok Soni <quic_tsoni@quicinc.com>, 
	Satya Durga Srinivasu Prabhala <quic_satyap@quicinc.com>, Jordan Crouse <jorcrous@amazon.com>
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On Tue, Dec 12, 2023 at 11:04=E2=80=AFAM John Moon <quic_johmoo@quicinc.com=
> 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@quicinc.com>
> ---
>     - Applied minor code style suggestions from v6 review.


The code looks OK. I think it should work as designed.

Line 197 is inconsistently indented by spaces instead of a space,
but I can fix it up locally.


I just thought requiring target commits as positional parameters
("check-uapi.sh treeA treeB" just like "git diff treeA treeB")
might be intuitive, but I guess everything is specified
by a short option is a design. I can live with that.


I will wait a few days, and if there is nothing more,
I will pick up 1/3 and 2/3.


--=20
Best Regards
Masahiro Yamada