From: Eric Sunshine Date: Sun, 05 Feb 2023 17:50:57 GMT Subject: Re: [PATCH 2/2] diff: teach diff to read gitattribute diff-algorithm Message-ID: In-Reply-To: <8e73793b0db3e84366a9c6441cc0fdc04f9614a5.1675568781.git.gitgitgadget@gmail.com> On Sat, Feb 4, 2023 at 11:47 PM John Cai via GitGitGadget wrote: > It can be useful to specify diff algorithms per file type. For example, > one may want to use the minimal diff algorithm for .json files, another > for .c files, etc. > > Teach the diff machinery to check attributes for a diff algorithm. > Enforce precedence by favoring the command line option, then looking at > attributes, then finally the config. > > To enforce precedence order, set the `xdl_opts_command_line` member > during options pasing to indicate the diff algorithm was set via command > line args. > > Signed-off-by: John Cai > --- > diff --git a/diff.c b/diff.c > @@ -3652,6 +3652,27 @@ static void builtin_diff(const char *name_a, > + if (!o->xdl_opts_command_line) { > + static struct attr_check *check; `check` is declared static... > + const char *one_diff_algo; > + const char *two_diff_algo; > + > + check = attr_check_alloc(); ... is allocated here... > + attr_check_append(check, git_attr("diff-algorithm")); > + > + git_check_attr(the_repository->index, NULL, one->path, check); > + one_diff_algo = check->items[0].value; > + git_check_attr(the_repository->index, NULL, two->path, check); > + two_diff_algo = check->items[0].value; > + > + if (!ATTR_UNSET(one_diff_algo) && !ATTR_UNSET(two_diff_algo) && > + !strcmp(one_diff_algo, two_diff_algo)) > + set_diff_algorithm(o, one_diff_algo); > + > + attr_check_free(check); ... and freed here... > + } ... so the reason for the `static` declaration is not clear. Am I missing something obvious?