[PATCH 2/2] notes: break set_display_notes() into smaller functions
In 8164c961e1 (format-patch: use --notes behavior for format.notes, 2019-12-09), we introduced set_display_notes() which was a monolithic function with three mutually exclusive branches. Break the function up into three small and simple functions that each are only responsible for one task.
This family of functions accepts an `int *show_notes` instead of returning a value suitable for assignment to `show_notes`. This is for two reasons. First of all, this guarantees that the external `show_notes` variable changes in lockstep with the `struct display_notes_opt`. Second, this prompts future developers to be careful about doing something meaningful with this value. In fact, a NULL check is intentionally omitted because causing a segfault here would tell the future developer that they are meant to use the value for something meaningful.
One alternative was making the family of functions accept a `struct rev_info *` instead of the `struct display_notes_opt *`, since the former contains the `show_notes` field as well. This does not work because we have to call git_config() before repo_init_revisions(). However, if we had a `struct rev_info`, we'd need to initialize it before it gets assigned values from git_config(). As a result, we break the circular dependency by having standalone `int show_notes` and `struct display_notes_opt notes_opt` variables which temporarily hold values from git_config() until the values are copied over to `rev`.
To implement this change, we need to get a pointer to `rev_info::show_notes`. Unfortunately, this is not possible with bitfields and only direct-assignment is possible. Change `rev_info::show_notes` to a non-bitfield int so that we can get its address.
Signed-off-by: Denton Liu <liu.denton@gmail.com>
---
builtin/log.c | 7 ++++++-
notes.c | 43 +++++++++++++++++++++++--------------------
notes.h | 19 ++++++++++++-------
revision.c | 6 +++---
revision.h | 2 +-
5 files changed, 45 insertions(+), 32 deletions(-)
Show changes to 5 files +45 −32
builtin/log.c, notes.c, notes.h, revision.c, revision.h
diff --git a/builtin/log.c b/builtin/log.c
index 4225615e7f..b6d43a4a47 100644
--- a/builtin/log.c
+++ b/builtin/log.c
@@ -868,7 +868,12 @@ static int git_format_config(const char *var, const char *value, void *cb)
}
if (!strcmp(var, "format.notes")) {
int b = git_parse_maybe_bool(value);
- show_notes = set_display_notes(¬es_opt, b, b < 0 ? value : NULL);
+ if (b < 0)
+ enable_ref_display_notes(¬es_opt, &show_notes, value);
+ else if (b)
+ enable_default_display_notes(¬es_opt, &show_notes);
+ else
+ disable_display_notes(¬es_opt, &show_notes);
return 0;
}
diff --git a/notes.c b/notes.c
index c93feff4ab..3133bb181f 100644
--- a/notes.c
+++ b/notes.c
@@ -1045,28 +1045,31 @@ void init_display_notes(struct display_notes_opt *opt)
opt->use_default_notes = -1;
}
-int set_display_notes(struct display_notes_opt *opt, int show_notes, const char *opt_ref)
+void enable_default_display_notes(struct display_notes_opt *opt, int *show_notes)
{
- if (show_notes) {
- if (opt_ref) {
- struct strbuf buf = STRBUF_INIT;
- strbuf_addstr(&buf, opt_ref);
- expand_notes_ref(&buf);
- string_list_append(&opt->extra_notes_refs,
- strbuf_detach(&buf, NULL));
- } else {
- opt->use_default_notes = 1;
- }
- } else {
- opt->use_default_notes = -1;
- /* we have been strdup'ing ourselves, so trick
- * string_list into free()ing strings */
- opt->extra_notes_refs.strdup_strings = 1;
- string_list_clear(&opt->extra_notes_refs, 0);
- opt->extra_notes_refs.strdup_strings = 0;
- }
+ opt->use_default_notes = 1;
+ *show_notes = 1;
+}
- return !!show_notes;
+void enable_ref_display_notes(struct display_notes_opt *opt, int *show_notes,
+ const char *ref) {
+ struct strbuf buf = STRBUF_INIT;
+ strbuf_addstr(&buf, ref);
+ expand_notes_ref(&buf);
+ string_list_append(&opt->extra_notes_refs,
+ strbuf_detach(&buf, NULL));
+ *show_notes = 1;
+}
+
+void disable_display_notes(struct display_notes_opt *opt, int *show_notes)
+{
+ opt->use_default_notes = -1;
+ /* we have been strdup'ing ourselves, so trick
+ * string_list into free()ing strings */
+ opt->extra_notes_refs.strdup_strings = 1;
+ string_list_clear(&opt->extra_notes_refs, 0);
+ opt->extra_notes_refs.strdup_strings = 0;
+ *show_notes = 0;
}
void load_display_notes(struct display_notes_opt *opt)
diff --git a/notes.h b/notes.h
index a476bfa066..3e78448181 100644
--- a/notes.h
+++ b/notes.h
@@ -266,14 +266,19 @@ struct display_notes_opt {
void init_display_notes(struct display_notes_opt *opt);
/*
- * Set a display_notes_opt to a given state. 'show_notes' is a boolean
- * representing whether or not to show notes. 'opt_ref' points to a
- * string for the notes ref, or is NULL if the default notes should be
- * used.
- *
- * Return 'show_notes' normalized to 1 or 0.
+ * This family of functions enables or disables the display of notes. In
+ * particular, 'enable_default_display_notes' will display the default notes,
+ * 'enable_default_display_notes' will display the notes ref 'ref' and
+ * 'disable_display_notes' will disable notes, including those added by previous
+ * invocations of the 'enable_*_display_notes' functions.
+ *
+ * 'show_notes' is a points to a boolean which will be set to 1 if notes are
+ * displayed, else 0. It must not be NULL.
*/
-int set_display_notes(struct display_notes_opt *opt, int show_notes, const char *opt_ref);
+void enable_default_display_notes(struct display_notes_opt *opt, int *show_notes);
+void enable_ref_display_notes(struct display_notes_opt *opt, int *show_notes,
+ const char *ref);
+void disable_display_notes(struct display_notes_opt *opt, int *show_notes);
/*
* Load the notes machinery for displaying several notes trees.
diff --git a/revision.c b/revision.c
index c2d8d24939..1b12ed742b 100644
--- a/revision.c
+++ b/revision.c
@@ -2172,7 +2172,7 @@ static int handle_revision_opt(struct rev_info *revs, int argc, const char **arg
die("'%s': not a non-negative integer", arg);
revs->expand_tabs_in_log = val;
} else if (!strcmp(arg, "--show-notes") || !strcmp(arg, "--notes")) {
- revs->show_notes = set_display_notes(&revs->notes_opt, 1, NULL);
+ enable_default_display_notes(&revs->notes_opt, &revs->show_notes);
revs->show_notes_given = 1;
} else if (!strcmp(arg, "--show-signature")) {
revs->show_signature = 1;
@@ -2191,10 +2191,10 @@ static int handle_revision_opt(struct rev_info *revs, int argc, const char **arg
if (starts_with(arg, "--show-notes=") &&
revs->notes_opt.use_default_notes < 0)
revs->notes_opt.use_default_notes = 1;
- revs->show_notes = set_display_notes(&revs->notes_opt, 1, optarg);
+ enable_ref_display_notes(&revs->notes_opt, &revs->show_notes, optarg);
revs->show_notes_given = 1;
} else if (!strcmp(arg, "--no-notes")) {
- revs->show_notes = set_display_notes(&revs->notes_opt, 0, NULL);
+ disable_display_notes(&revs->notes_opt, &revs->show_notes);
revs->show_notes_given = 1;
} else if (!strcmp(arg, "--standard-notes")) {
revs->show_notes_given = 1;
diff --git a/revision.h b/revision.h
index 4134dc6029..72520780f4 100644
--- a/revision.h
+++ b/revision.h
@@ -177,10 +177,10 @@ struct rev_info {
always_show_header:1;
/* Format info */
+ int show_notes;
unsigned int shown_one:1,
shown_dashes:1,
show_merge:1,
- show_notes:1,
show_notes_given:1,
show_signature:1,
pretty_given:1,
--
2.24.0.627.geba02921db
Denton Liu