From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS53758 23.128.96.0/24 X-Spam-Status: No, score=-3.7 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED, SPF_HELO_PASS,SPF_PASS shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by dcvr.yhbt.net (Postfix) with ESMTP id 053181F8C8 for ; Mon, 4 Oct 2021 15:06:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235463AbhJDPIW (ORCPT ); Mon, 4 Oct 2021 11:08:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58556 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235461AbhJDPIR (ORCPT ); Mon, 4 Oct 2021 11:08:17 -0400 Received: from mail-ed1-x532.google.com (mail-ed1-x532.google.com [IPv6:2a00:1450:4864:20::532]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C7198C061745 for ; Mon, 4 Oct 2021 08:06:27 -0700 (PDT) Received: by mail-ed1-x532.google.com with SMTP id r18so65952444edv.12 for ; Mon, 04 Oct 2021 08:06:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=Bq61P6D0Jnz6xbWmO5USVQbKs/lUttrBFLhn9lUYDdM=; b=qlPyMKBwWZC5I50Qi7smRRMPxrOZ4P7h+OGMbe0Sxmlbk3NOTqJzStDmpo5Fx6CxLc lFH49syMDftPZMIH4bCUiFPnPQd15qI12ctTRWNlk3wSnxv34Ee6dwtes1xT4Yup6HZj KLqdxZD9oLvfIX910+0mjZ8RrDbspxNX48ea6eFIc1mX3yHR8o82OENYxz9MVmO8mGVs B16L7UharR8aPkEjNZ6hH0KGxUgCL6YBqVmHeqs7g7fefY4yj93iL+0k5TfLItk7xKWW QdsOARKEUbBVE4GuJGwj+GZhxcq8qtBgywG/49qdsfPZSKymNnawrfd9x4bT/TVfJvWZ X1Fg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=Bq61P6D0Jnz6xbWmO5USVQbKs/lUttrBFLhn9lUYDdM=; b=lMgSM1BCFJ6fYH+ZH1pRyOYlt63gq+QLDK08fOYA1+5samjIHaIhtxnSrNKj5svkcP 5VhN56mU6NKY0KsM7lTs6iJ3RO9RG8U5oTuhBWZMEZz9eXZR8GMBvjQysQ3pQ5An013t NojhOCwgN1GO4p8rWZfgE2YcUJO71SvdOXyB8MwynF3BhUAfxooWeBzf/0dRsOtsYdqX 4jjxRgu7ZDgS34D34jVaqcGoYYn20gOMlECyjiORwnW9eKQfyWfCn4kxB7A3/LBp6BEP Xx7K+oL0tjCWorF8ufH+u4tVlIQdJUHpP0fVvfingJCkj8wIZEL1O61hxL7ma2+kGgnp JIQA== X-Gm-Message-State: AOAM532gLndpgqepMxqoZlvPASKqx4bIS63UVaA7JQn0sEilTPz/Iwe1 R2aH4fcaC1HWjAzGrdr5thNKlSALnCEkBwJv7eg= X-Google-Smtp-Source: ABdhPJxT39tqahy46KrhR/CtJNd1gZjSd5bvHhKAk4KsXwzcWJdKgDHT7Mw0uvgD2JOTnGLinf/3A8a6aRX4LTjYbE4= X-Received: by 2002:a17:906:544f:: with SMTP id d15mr18186650ejp.520.1633359851090; Mon, 04 Oct 2021 08:04:11 -0700 (PDT) MIME-Version: 1.0 References: <87y278n8tt.fsf@evledraar.gmail.com> In-Reply-To: <87y278n8tt.fsf@evledraar.gmail.com> From: Elijah Newren Date: Mon, 4 Oct 2021 08:04:00 -0700 Message-ID: Subject: Re: [PATCH 02/10] merge-recursive.c: call a new unpack_trees_options_init() function To: =?UTF-8?B?w4Z2YXIgQXJuZmrDtnLDsCBCamFybWFzb24=?= Cc: Git Mailing List , Junio C Hamano , =?UTF-8?B?Tmd1eeG7hW4gVGjDoWkgTmfhu41jIER1eQ==?= , =?UTF-8?Q?Martin_=C3=85gren?= , Andrzej Hunt , Jeff King Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org On Mon, Oct 4, 2021 at 7:49 AM =C3=86var Arnfj=C3=B6r=C3=B0 Bjarmason wrote: > > On Mon, Oct 04 2021, Elijah Newren wrote: > > > On Sun, Oct 3, 2021 at 5:46 PM =C3=86var Arnfj=C3=B6r=C3=B0 Bjarmason <= avarab@gmail.com> wrote: > >> > >> In the preceding commit we introduced a new UNPACK_TREES_OPTIONS_INIT > >> macro, but "merge-recursive.c" could not be converted to it since > >> it (re-)initializes a "struct unpack_trees_options" on the heap. > >> > >> In order to convert use the macro as the source of truth for > >> initialization we need to not only convert the initialization in > >> unpack_trees_start(), but also call the new > >> unpack_trees_options_init() just after the CALLOC_ARRAY() in > >> merge_start(). > > > > Um...why? > > Replied below. > > >> When we call merge_trees() we'll call merge_start() followed by > >> merge_trees_internal(), and it will call unpack_trees_start() before > >> it does much of anything. So it's covered by an initialization in > >> unpack_trees_start(). > >> > >> But when merge_recursive() is called it will call merge_start() > >> followed by merge_recursive_internal(), which won't call > >> unpack_trees_start() until its own call call to > >> merge_trees_internal(), but in the meantime it might end up using that > >> calloc'd "struct unpack_trees_options". > > > > Nothing in merge-recursive.c usings unpack_opts before > > unpack_trees_start() or after unpack_trees_finish(). If anyone > > attempts to use it elsewhere, that would itself be a bug. So, I'd > > replace the above three paragraphs with: > > > > "Change the initialization of opt->priv_unpack_opts from using memset > > to 0, with unpack_trees_options_init()." > > > > or something like that, and then drop your change to merge_start(). > > Sure, I'll defer to you about being confident about that. I didn't want > to leave a copy if it hanging without the proper initialization in case > there were new callers. > > >> This was OK before, as setup_unpack_trees_porcelain() would call > >> strvec_init(), and our "struct dir_struct" in turn is OK with being > >> NULL'd. Let's convert the former to macro initialization, we'll deal > >> with the latter in a subsequent commit. > > > > This is quite confusing; it's really hard to understand how this > > relates to the rest of the commit message. I have to read the code to > > see what you're doing, and then write my own commit message in my head > > because the wording in this paragraph still doesn't parse. > > > > I'd make the change strvec_init/STRVEC_INIT changes be a separate > > patch. I suspect it'll be easier to write the commit message for it > > as a standalone commit as well. > > Sure, FWIW I had it split up locally, and figured it would be easier to > explain if the API usage change came with the initialization change that > made it possible. > > >> > >> Signed-off-by: =C3=86var Arnfj=C3=B6r=C3=B0 Bjarmason > >> --- > >> merge-recursive.c | 3 ++- > >> unpack-trees.c | 8 ++++++-- > >> unpack-trees.h | 5 ++++- > >> 3 files changed, 12 insertions(+), 4 deletions(-) > >> > >> diff --git a/merge-recursive.c b/merge-recursive.c > >> index e594d4c3fa1..d24a4903f1d 100644 > >> --- a/merge-recursive.c > >> +++ b/merge-recursive.c > >> @@ -405,7 +405,7 @@ static int unpack_trees_start(struct merge_options= *opt, > >> struct tree_desc t[3]; > >> struct index_state tmp_index =3D { NULL }; > >> > >> - memset(&opt->priv->unpack_opts, 0, sizeof(opt->priv->unpack_op= ts)); > >> + unpack_trees_options_init(&opt->priv->unpack_opts); > >> if (opt->priv->call_depth) > >> opt->priv->unpack_opts.index_only =3D 1; > >> else > >> @@ -3704,6 +3704,7 @@ static int merge_start(struct merge_options *opt= , struct tree *head) > >> > >> CALLOC_ARRAY(opt->priv, 1); > >> string_list_init_dup(&opt->priv->df_conflict_file_set); > >> + unpack_trees_options_init(&opt->priv->unpack_opts); > > > > Drop this hunk. > > Speaking of splitting things up in more understandable ways: If we're > going to hard rely on the interaction between merge_start() and > unpack_trees_start() wouldn't it make sense to lead with a change that > dropped that memset, which if this invariant holds is also redundant to > the CALLOC() of opt->priv in merge_start() in the pre-image. It is not redundant, and that would be a very confusing change. merge-recursive is so named because its main driving function contains recursive calls to itself. merge_start() is not involved in that recursion. For readability, we should initialize unpack_opts before each use.