Re: [RFC] ChangeLog generation script

[Khem Raj <raj dot khem at gmail dot com>]

On Mon, Nov 19, 2018 at 11:57 AM Siddhesh Poyarekar <siddhesh@gotplt.org> wrote:
>
> Hello,
>
> I am back from under my rock with a draft of the ChangeLog generation
> script.  I've had this ready for a while but was trying to make it run
> faster - it currently takes a little under 30 seconds to generate the
> ChangeLog between glibc-2.27 and glibc-2.28.  I hae a few ideas to
> reduce the time spent (like using git diff -U100000 instead of the two
> files) but I can pursue them after the script has gone in as well.
>
> At a high level the script accepts two inputs, a from-ref and a to-ref
> and generates a ChangeLog like output between these refs.  Note that
> this is not a proper ChangeLog; it provides a lot of the information
> that a ChangeLog would give and some additional information in context
> of its origin, i.e. the git history.
>
> The script goes through each ref in the range and for each ref, gets the
> before and after refs of each change.  For non-C code (i.e anything that
> is not *.c or *.h), it indicates whether the file was added, deleted,
> modified or renamed.
>
> For C code, it goes further for modifications and renames where the old
> and new file are not identical, by generating parse trees for the old
> and new files and compares those trees to generate a source level ChangeLog.
>
> What it can detect:
>
> - Adds, modifications, renames and deletions.
>
> - Top level objects like static variables, function declarations and
> definitions, structs and unions and assignments.
>
> - Nesting within macro conditions.  It's not perfect, but pretty decent.
>
> What it cannot do yet:
>
> - Detect changes to comments.  It's just dropping all comments right
> now, so changes that are comment-only end up seeming identical.
>
> - Changes within function definitions, struct members.  The script only
> knows that it changed, not what changed inside.
>
> - Weird macro nesting will break things.  I tried to adjust for some
> weirdness that I encountered in my testing, but I am confident that an
> 'innovative' C programmer can break this.
>
> Overall I reckon that this is good to go in terms of concept, but that's
> only because I'm the script's mommy and mommies always think their
> babies are the best.
>
> Comments welcome!

its a promising start. Have you looked into
https://keepachangelog.com/en/1.0.0/

>
> Siddhesh