From: Junio C Hamano <gitster@pobox.com>
To: Ezekiel Newren <ezekielnewren@gmail.com>
Cc: Phillip Wood <phillip.wood123@gmail.com>,
Ezekiel Newren via GitGitGadget <gitgitgadget@gmail.com>,
git@vger.kernel.org, Elijah Newren <newren@gmail.com>,
Ben Knoble <ben.knoble@gmail.com>, Jeff King <peff@peff.net>
Subject: Re: [PATCH v5 10/13] xdiff: delete rchg aliasing
Date: Wed, 24 Sep 2025 14:31:28 -0700 [thread overview]
Message-ID: <xmqqikh7k05r.fsf@gitster.g> (raw)
In-Reply-To: <CAH=ZcbAcvoXJYPHE=mcZSqPLuUPxKcSs-vd307X7uXi+aG3evw@mail.gmail.com> (Ezekiel Newren's message of "Wed, 24 Sep 2025 09:58:11 -0600")
Ezekiel Newren <ezekielnewren@gmail.com> writes:
> I have a question for everyone: Does preparing C code to be translated
> into Rust count as a valid reason for changing it? Provided that there
> is no violation of the Git style (or very small in some cases).
>
> If my intent was to keep this as C code forever I'd agree, but...
You'd agree that "I am preparing this for eventual rewrite" would be
a valid reason? Or you are agreeing with something else?
> My
> other reason is that it more closely follows Rust paradigms. Creating
> multiple pointers to the same memory in Rust subverts the borrow
> checker's ability to keep track of who owns the memory.
Sure. But looking at the use of rchg[12] in xdl_build_script(), if
they were "const char *", combined with the fact that they are local
and their addresses are never taken (to be leaked to our callers),
you wouldn't have much trouble with the current code, or would you
still have issues?
next prev parent reply other threads:[~2025-09-24 21:31 UTC|newest]
Thread overview: 158+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-09-07 19:45 [PATCH 00/17] Use rust types in xdiff Ezekiel Newren via GitGitGadget
2025-09-07 19:45 ` [PATCH 01/17] xdiff: delete static forward declarations in xprepare Ezekiel Newren via GitGitGadget
2025-09-09 8:55 ` Elijah Newren
2025-09-07 19:45 ` [PATCH 02/17] xdiff: delete local variables and initialize/free xdfile_t directly Ezekiel Newren via GitGitGadget
2025-09-09 8:56 ` Elijah Newren
2025-09-07 19:45 ` [PATCH 03/17] xdiff: delete unnecessary fields from xrecord_t and xdfile_t Ezekiel Newren via GitGitGadget
2025-09-09 8:56 ` Elijah Newren
2025-09-07 19:45 ` [PATCH 04/17] xdiff: delete xdl_get_rec() in xemit Ezekiel Newren via GitGitGadget
2025-09-09 8:56 ` Elijah Newren
2025-09-07 19:45 ` [PATCH 05/17] xdiff: delete struct diffdata_t Ezekiel Newren via GitGitGadget
2025-09-09 8:56 ` Elijah Newren
2025-09-07 19:45 ` [PATCH 06/17] xdiff: delete redundant array xdfile_t.ha Ezekiel Newren via GitGitGadget
2025-09-09 8:57 ` Elijah Newren
2025-09-07 19:45 ` [PATCH 07/17] xdiff: delete fields ha, line, size in xdlclass_t in favor of an xrecord_t Ezekiel Newren via GitGitGadget
2025-09-09 8:57 ` Elijah Newren
2025-09-07 19:45 ` [PATCH 08/17] xdiff: delete chastore from xdfile_t, view with --color-words Ezekiel Newren via GitGitGadget
2025-09-09 8:58 ` Elijah Newren
2025-09-09 13:50 ` Phillip Wood
2025-09-09 20:33 ` Junio C Hamano
2025-09-10 22:02 ` Ben Knoble
2025-09-07 19:45 ` [PATCH 09/17] xdiff: treat xdfile_t.rchg like an enum Ezekiel Newren via GitGitGadget
2025-09-09 8:58 ` Elijah Newren
2025-09-07 19:45 ` [PATCH 10/17] compat/rust_types.h: define rust primitive types Ezekiel Newren via GitGitGadget
2025-09-08 15:08 ` Junio C Hamano
2025-09-08 16:15 ` Ezekiel Newren
2025-09-07 19:45 ` [PATCH 11/17] xdiff: include compat/rust_types.h Ezekiel Newren via GitGitGadget
2025-09-07 19:45 ` [PATCH 12/17] xdiff: make xrecord_t.ptr a u8 instead of char Ezekiel Newren via GitGitGadget
2025-09-07 19:45 ` [PATCH 13/17] xdiff: make xrecord_t.size a usize instead of long Ezekiel Newren via GitGitGadget
2025-09-07 19:45 ` [PATCH 14/17] xdiff: split xrecord_t.ha into line_hash and minimal_perfect_hash Ezekiel Newren via GitGitGadget
2025-09-07 19:45 ` [PATCH 15/17] xdiff: make xdfile_t.nrec a usize instead of long Ezekiel Newren via GitGitGadget
2025-09-07 19:45 ` [PATCH 16/17] xdiff: make xdfile_t.nreff " Ezekiel Newren via GitGitGadget
2025-09-07 19:45 ` [PATCH 17/17] xdiff: change the types of dstart, dend, rchg, and rindex in xdfile_t Ezekiel Newren via GitGitGadget
2025-09-16 21:56 ` [PATCH 00/17] Use rust types in xdiff Junio C Hamano
2025-09-16 22:01 ` Ezekiel Newren
2025-09-17 2:16 ` Elijah Newren
2025-09-17 13:53 ` Junio C Hamano
2025-09-17 6:22 ` Junio C Hamano
2025-09-18 23:56 ` [PATCH v2 00/10] " Ezekiel Newren via GitGitGadget
2025-09-18 23:56 ` [PATCH v2 01/10] xdiff: delete static forward declarations in xprepare Ezekiel Newren via GitGitGadget
2025-09-18 23:56 ` [PATCH v2 02/10] xdiff: delete local variables and initialize/free xdfile_t directly Ezekiel Newren via GitGitGadget
2025-09-18 23:56 ` [PATCH v2 03/10] xdiff: delete unnecessary fields from xrecord_t and xdfile_t Ezekiel Newren via GitGitGadget
2025-09-18 23:56 ` [PATCH v2 04/10] xdiff: delete xdl_get_rec() in xemit Ezekiel Newren via GitGitGadget
2025-09-18 23:56 ` [PATCH v2 05/10] xdiff: delete struct diffdata_t Ezekiel Newren via GitGitGadget
2025-09-18 23:56 ` [PATCH v2 06/10] xdiff: delete redundant array xdfile_t.ha Ezekiel Newren via GitGitGadget
2025-09-18 23:56 ` [PATCH v2 07/10] xdiff: delete fields ha, line, size in xdlclass_t in favor of an xrecord_t Ezekiel Newren via GitGitGadget
2025-09-18 23:56 ` [PATCH v2 08/10] xdiff: delete chastore from xdfile_t Ezekiel Newren via GitGitGadget
2025-09-18 23:56 ` [PATCH v2 10/10] xdiff: treat xdfile_t.rchg like an enum Ezekiel Newren via GitGitGadget
2025-09-19 0:33 ` [PATCH v2 00/10] Use rust types in xdiff Junio C Hamano
2025-09-19 0:41 ` Ezekiel Newren
2025-09-19 15:15 ` Ezekiel Newren
2025-09-19 15:16 ` [PATCH v3 00/10] Cleanup xdfile_t and xrecord_t " Ezekiel Newren via GitGitGadget
2025-09-19 15:16 ` [PATCH v3 01/10] xdiff: delete static forward declarations in xprepare Ezekiel Newren via GitGitGadget
2025-09-20 17:16 ` Junio C Hamano
2025-09-20 17:41 ` Ezekiel Newren
2025-09-20 18:31 ` Elijah Newren
2025-09-20 22:25 ` Ben Knoble
2025-09-20 22:43 ` Junio C Hamano
2025-09-20 17:46 ` Ben Knoble
2025-09-20 18:46 ` Jeff King
2025-09-20 22:25 ` Ben Knoble
2025-09-20 22:52 ` Junio C Hamano
2025-09-20 23:15 ` Jeff King
2025-09-19 15:16 ` [PATCH v3 02/10] xdiff: delete local variables and initialize/free xdfile_t directly Ezekiel Newren via GitGitGadget
2025-09-20 17:36 ` Junio C Hamano
2025-09-19 15:16 ` [PATCH v3 03/10] xdiff: delete unnecessary fields from xrecord_t and xdfile_t Ezekiel Newren via GitGitGadget
2025-09-19 15:16 ` [PATCH v3 04/10] xdiff: delete xdl_get_rec() in xemit Ezekiel Newren via GitGitGadget
2025-09-20 17:48 ` Junio C Hamano
2025-09-21 13:06 ` Phillip Wood
2025-09-21 15:07 ` Ezekiel Newren
2025-09-19 15:16 ` [PATCH v3 05/10] xdiff: delete struct diffdata_t Ezekiel Newren via GitGitGadget
2025-09-21 13:06 ` Phillip Wood
2025-09-21 16:03 ` Ezekiel Newren
2025-09-19 15:16 ` [PATCH v3 06/10] xdiff: delete redundant array xdfile_t.ha Ezekiel Newren via GitGitGadget
2025-09-19 15:16 ` [PATCH v3 07/10] xdiff: delete fields ha, line, size in xdlclass_t in favor of an xrecord_t Ezekiel Newren via GitGitGadget
2025-09-21 13:06 ` Phillip Wood
2025-09-21 16:07 ` Ezekiel Newren
2025-09-19 15:16 ` [PATCH v3 08/10] xdiff: delete chastore from xdfile_t Ezekiel Newren via GitGitGadget
2025-09-19 15:16 ` [PATCH v3 09/10] xdiff: delete rchg aliasing Ezekiel Newren via GitGitGadget
2025-09-21 13:07 ` Phillip Wood
2025-09-21 16:37 ` Ezekiel Newren
2025-09-19 15:16 ` [PATCH v3 10/10] xdiff: treat xdfile_t.rchg like an enum Ezekiel Newren via GitGitGadget
2025-09-21 0:00 ` Junio C Hamano
2025-09-21 0:38 ` Ezekiel Newren
2025-09-21 9:19 ` Phillip Wood
2025-09-21 16:11 ` Ezekiel Newren
2025-09-19 23:30 ` [PATCH v3 00/10] Cleanup xdfile_t and xrecord_t in xdiff Elijah Newren
2025-09-19 23:37 ` Ezekiel Newren
2025-09-22 19:51 ` [PATCH v4 00/12] " Ezekiel Newren via GitGitGadget
2025-09-22 19:51 ` [PATCH v4 01/12] xdiff: delete static forward declarations in xprepare Ezekiel Newren via GitGitGadget
2025-09-22 19:51 ` [PATCH v4 02/12] xdiff: delete local variables and initialize/free xdfile_t directly Ezekiel Newren via GitGitGadget
2025-09-22 19:51 ` [PATCH v4 03/12] xdiff: delete unnecessary fields from xrecord_t and xdfile_t Ezekiel Newren via GitGitGadget
2025-09-22 19:51 ` [PATCH v4 04/12] xdiff: delete superfluous function xdl_get_rec() in xemit Ezekiel Newren via GitGitGadget
2025-09-22 19:51 ` [PATCH v4 05/12] xdiff: delete superfluous local variables that alias fields in xrecord_t Ezekiel Newren via GitGitGadget
2025-09-22 19:51 ` [PATCH v4 06/12] xdiff: delete struct diffdata_t Ezekiel Newren via GitGitGadget
2025-09-22 19:51 ` [PATCH v4 07/12] xdiff: delete redundant array xdfile_t.ha Ezekiel Newren via GitGitGadget
2025-09-22 19:51 ` [PATCH v4 08/12] xdiff: delete fields ha, line, size in xdlclass_t in favor of an xrecord_t Ezekiel Newren via GitGitGadget
2025-09-22 19:51 ` [PATCH v4 09/12] xdiff: delete chastore from xdfile_t Ezekiel Newren via GitGitGadget
2025-09-22 19:51 ` [PATCH v4 10/12] xdiff: delete rchg aliasing Ezekiel Newren via GitGitGadget
2025-09-22 19:51 ` [PATCH v4 11/12] xdiff: use bool literals for xdfile_t.rchg Ezekiel Newren via GitGitGadget
2025-09-22 19:51 ` [PATCH v4 12/12] xdiff: refactor 'char *rchg' to 'bool *changed' in xdfile_t Ezekiel Newren via GitGitGadget
2025-09-22 22:39 ` [PATCH v4 00/12] Cleanup xdfile_t and xrecord_t in xdiff Junio C Hamano
2025-09-23 0:13 ` Ezekiel Newren
2025-09-23 1:06 ` Junio C Hamano
2025-09-23 1:30 ` Ezekiel Newren
2025-09-23 14:12 ` Junio C Hamano
2025-09-23 16:50 ` Ezekiel Newren
2025-09-23 21:24 ` [PATCH v5 00/13] " Ezekiel Newren via GitGitGadget
2025-09-23 21:24 ` [PATCH v5 01/13] xdiff: delete static forward declarations in xprepare Ezekiel Newren via GitGitGadget
2025-09-23 21:24 ` [PATCH v5 02/13] xdiff: delete local variables and initialize/free xdfile_t directly Ezekiel Newren via GitGitGadget
2025-09-23 21:24 ` [PATCH v5 03/13] xdiff: delete unnecessary fields from xrecord_t and xdfile_t Ezekiel Newren via GitGitGadget
2025-09-23 21:24 ` [PATCH v5 04/13] xdiff: delete superfluous function xdl_get_rec() in xemit Ezekiel Newren via GitGitGadget
2025-09-30 13:31 ` Kristoffer Haugsbakk
2025-09-30 19:35 ` Ezekiel Newren
2025-09-30 20:05 ` Junio C Hamano
2025-09-23 21:24 ` [PATCH v5 05/13] xdiff: delete superfluous local variables that alias fields in xrecord_t Ezekiel Newren via GitGitGadget
2025-09-24 10:22 ` Phillip Wood
2025-09-24 14:52 ` Ezekiel Newren
2025-09-23 21:24 ` [PATCH v5 06/13] xdiff: delete struct diffdata_t Ezekiel Newren via GitGitGadget
2025-09-23 21:24 ` [PATCH v5 07/13] xdiff: delete redundant array xdfile_t.ha Ezekiel Newren via GitGitGadget
2025-09-23 21:24 ` [PATCH v5 08/13] xdiff: delete fields ha, line, size in xdlclass_t in favor of an xrecord_t Ezekiel Newren via GitGitGadget
2025-09-23 21:24 ` [PATCH v5 09/13] xdiff: delete chastore from xdfile_t Ezekiel Newren via GitGitGadget
2025-09-23 21:24 ` [PATCH v5 10/13] xdiff: delete rchg aliasing Ezekiel Newren via GitGitGadget
2025-09-24 10:22 ` Phillip Wood
2025-09-24 15:01 ` Ezekiel Newren
2025-09-24 15:34 ` Junio C Hamano
2025-09-24 15:58 ` Ezekiel Newren
2025-09-24 21:31 ` Junio C Hamano [this message]
2025-09-24 22:46 ` Ezekiel Newren
2025-09-25 7:09 ` Junio C Hamano
2025-09-25 22:02 ` Ezekiel Newren
2025-09-23 21:24 ` [PATCH v5 11/13] xdiff: rename rchg -> changed in xdfile_t Ezekiel Newren via GitGitGadget
2025-09-24 10:22 ` Phillip Wood
2025-09-24 15:10 ` Ezekiel Newren
2025-09-24 15:18 ` Phillip Wood
2025-09-23 21:24 ` [PATCH v5 12/13] xdiff: use enum macros NONE(0), SOME(1), TOO_MANY(2) in xprepare.c Ezekiel Newren via GitGitGadget
2025-09-24 10:21 ` Phillip Wood
2025-09-24 14:46 ` Ezekiel Newren
2025-09-24 15:18 ` Phillip Wood
2025-09-24 17:29 ` Junio C Hamano
2025-09-25 18:40 ` Ezekiel Newren
2025-09-26 2:29 ` Ezekiel Newren
2025-09-23 21:24 ` [PATCH v5 13/13] xdiff: change type of xdfile_t.changed from char to bool Ezekiel Newren via GitGitGadget
2025-09-24 10:21 ` Phillip Wood
2025-09-24 15:14 ` Ezekiel Newren
2025-09-26 22:41 ` [PATCH v6 00/12] Cleanup xdfile_t and xrecord_t in xdiff Ezekiel Newren via GitGitGadget
2025-09-26 22:41 ` [PATCH v6 01/12] xdiff: delete static forward declarations in xprepare Ezekiel Newren via GitGitGadget
2025-09-26 22:41 ` [PATCH v6 02/12] xdiff: delete local variables and initialize/free xdfile_t directly Ezekiel Newren via GitGitGadget
2025-09-26 22:41 ` [PATCH v6 03/12] xdiff: delete unnecessary fields from xrecord_t and xdfile_t Ezekiel Newren via GitGitGadget
2025-09-26 22:41 ` [PATCH v6 04/12] xdiff: delete superfluous function xdl_get_rec() in xemit Ezekiel Newren via GitGitGadget
2025-09-26 22:41 ` [PATCH v6 05/12] xdiff: delete local variables that alias fields in xrecord_t Ezekiel Newren via GitGitGadget
2025-09-26 22:41 ` [PATCH v6 06/12] xdiff: delete struct diffdata_t Ezekiel Newren via GitGitGadget
2025-09-26 22:41 ` [PATCH v6 07/12] xdiff: delete redundant array xdfile_t.ha Ezekiel Newren via GitGitGadget
2025-09-26 22:41 ` [PATCH v6 08/12] xdiff: delete fields ha, line, size in xdlclass_t in favor of an xrecord_t Ezekiel Newren via GitGitGadget
2025-09-26 22:41 ` [PATCH v6 09/12] xdiff: delete chastore from xdfile_t Ezekiel Newren via GitGitGadget
2025-09-26 22:41 ` [PATCH v6 10/12] xdiff: rename rchg -> changed in xdfile_t Ezekiel Newren via GitGitGadget
2025-09-26 22:41 ` [PATCH v6 11/12] xdiff: add macros DISCARD(0), KEEP(1), INVESTIGATE(2) in xprepare.c Ezekiel Newren via GitGitGadget
2025-09-26 22:41 ` [PATCH v6 12/12] xdiff: change type of xdfile_t.changed from char to bool Ezekiel Newren via GitGitGadget
2025-10-03 13:47 ` [PATCH v6 00/12] Cleanup xdfile_t and xrecord_t in xdiff Phillip Wood
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