Merge branch 'ma/grep-init-default'

Code clean-up.

* ma/grep-init-default:
  MyFirstObjectWalk: drop `init_walken_defaults()`
  grep: copy struct in one fell swoop
  grep: use designated initializers for `grep_defaults`
  grep: don't set up a "default" repo for grep

Documentation/MyFirstObjectWalk.txt

@@ -182,30 +182,6 @@ its `init_log_defaults()` sets its own state (`decoration_style`) and asks
 `grep` and `diff` to initialize themselves by calling each of their
 initialization functions.
 
-For our first example within `git walken`, we don't intend to use any other
-components within Git, and we don't have any configuration to do.  However, we
-may want to add some later, so for now, we can add an empty placeholder. Create
-a new function in `builtin/walken.c`:
-
-----
-static void init_walken_defaults(void)
-{
-	/*
-	 * We don't actually need the same components `git log` does; leave this
-	 * empty for now.
-	 */
-}
-----
-
-Make sure to add a line invoking it inside of `cmd_walken()`.
-
-----
-int cmd_walken(int argc, const char **argv, const char *prefix)
-{
-	init_walken_defaults();
-}
-----
-
 ==== Configuring From `.gitconfig`
 
 Next, we should have a look at any relevant configuration settings (i.e.,
@@ -388,17 +364,9 @@ Next, let's try to filter the commits we see based on their author. This is
 equivalent to running `git log --author=<pattern>`. We can add a filter by
 modifying `rev_info.grep_filter`, which is a `struct grep_opt`.
 
-First some setup. Add `init_grep_defaults()` to `init_walken_defaults()` and add
-`grep_config()` to `git_walken_config()`:
+First some setup. Add `grep_config()` to `git_walken_config()`:
 
 ----
-static void init_walken_defaults(void)
-{
-	init_grep_defaults(the_repository);
-}
-
-...
-
 static int git_walken_config(const char *var, const char *value, void *cb)
 {
 	grep_config(var, value, cb);

builtin/grep.c

@@ -950,7 +950,6 @@ int cmd_grep(int argc, const char **argv, const char *prefix)
 		OPT_END()
 	};
 
-	init_grep_defaults(the_repository);
 	git_config(grep_cmd_config, NULL);
 	grep_init(&opt, the_repository, prefix);
 

builtin/log.c

@@ -133,7 +133,6 @@ static int log_line_range_callback(const struct option *option, const char *arg,
 
 static void init_log_defaults(void)
 {
-	init_grep_defaults(the_repository);
 	init_diff_ui_defaults();
 
 	decoration_style = auto_decoration_style();

grep.c

@@ -14,7 +14,31 @@ static int grep_source_load(struct grep_source *gs);
 static int grep_source_is_binary(struct grep_source *gs,
 				 struct index_state *istate);
 
-static struct grep_opt grep_defaults;
+static void std_output(struct grep_opt *opt, const void *buf, size_t size)
+{
+	fwrite(buf, size, 1, stdout);
+}
+
+static struct grep_opt grep_defaults = {
+	.relative = 1,
+	.pathname = 1,
+	.max_depth = -1,
+	.pattern_type_option = GREP_PATTERN_TYPE_UNSPECIFIED,
+	.colors = {
+		[GREP_COLOR_CONTEXT] = "",
+		[GREP_COLOR_FILENAME] = "",
+		[GREP_COLOR_FUNCTION] = "",
+		[GREP_COLOR_LINENO] = "",
+		[GREP_COLOR_COLUMNNO] = "",
+		[GREP_COLOR_MATCH_CONTEXT] = GIT_COLOR_BOLD_RED,
+		[GREP_COLOR_MATCH_SELECTED] = GIT_COLOR_BOLD_RED,
+		[GREP_COLOR_SELECTED] = "",
+		[GREP_COLOR_SEP] = GIT_COLOR_CYAN,
+	},
+	.only_matching = 0,
+	.color = -1,
+	.output = std_output,
+};
 
 #ifdef USE_LIBPCRE2
 static pcre2_general_context *pcre2_global_context;
@@ -42,50 +66,6 @@ static const char *color_grep_slots[] = {
 	[GREP_COLOR_SEP]	    = "separator",
 };
 
-static void std_output(struct grep_opt *opt, const void *buf, size_t size)
-{
-	fwrite(buf, size, 1, stdout);
-}
-
-static void color_set(char *dst, const char *color_bytes)
-{
-	xsnprintf(dst, COLOR_MAXLEN, "%s", color_bytes);
-}
-
-/*
- * Initialize the grep_defaults template with hardcoded defaults.
- * We could let the compiler do this, but without C99 initializers
- * the code gets unwieldy and unreadable, so...
- */
-void init_grep_defaults(struct repository *repo)
-{
-	struct grep_opt *opt = &grep_defaults;
-	static int run_once;
-
-	if (run_once)
-		return;
-	run_once++;
-
-	memset(opt, 0, sizeof(*opt));
-	opt->repo = repo;
-	opt->relative = 1;
-	opt->pathname = 1;
-	opt->max_depth = -1;
-	opt->pattern_type_option = GREP_PATTERN_TYPE_UNSPECIFIED;
-	color_set(opt->colors[GREP_COLOR_CONTEXT], "");
-	color_set(opt->colors[GREP_COLOR_FILENAME], "");
-	color_set(opt->colors[GREP_COLOR_FUNCTION], "");
-	color_set(opt->colors[GREP_COLOR_LINENO], "");
-	color_set(opt->colors[GREP_COLOR_COLUMNNO], "");
-	color_set(opt->colors[GREP_COLOR_MATCH_CONTEXT], GIT_COLOR_BOLD_RED);
-	color_set(opt->colors[GREP_COLOR_MATCH_SELECTED], GIT_COLOR_BOLD_RED);
-	color_set(opt->colors[GREP_COLOR_SELECTED], "");
-	color_set(opt->colors[GREP_COLOR_SEP], GIT_COLOR_CYAN);
-	opt->only_matching = 0;
-	opt->color = -1;
-	opt->output = std_output;
-}
-
 static int parse_pattern_type_arg(const char *opt, const char *arg)
 {
 	if (!strcmp(arg, "default"))
@@ -115,6 +95,14 @@ int grep_config(const char *var, const char *value, void *cb)
 	if (userdiff_config(var, value) < 0)
 		return -1;
 
+	/*
+	 * The instance of grep_opt that we set up here is copied by
+	 * grep_init() to be used by each individual invocation.
+	 * When populating a new field of this structure here, be
+	 * sure to think about ownership -- e.g., you might need to
+	 * override the shallow copy in grep_init() with a deep copy.
+	 */
+
 	if (!strcmp(var, "grep.extendedregexp")) {
 		opt->extended_regexp_option = git_config_bool(var, value);
 		return 0;
@@ -172,9 +160,6 @@ int grep_config(const char *var, const char *value, void *cb)
  */
 void grep_init(struct grep_opt *opt, struct repository *repo, const char *prefix)
 {
-	struct grep_opt *def = &grep_defaults;
-	int i;
-
 #if defined(USE_LIBPCRE2)
 	if (!pcre2_global_context)
 		pcre2_global_context = pcre2_general_context_create(
@@ -186,26 +171,13 @@ void grep_init(struct grep_opt *opt, struct repository *repo, const char *prefix
 	pcre_free = free;
 #endif
 
-	memset(opt, 0, sizeof(*opt));
+	*opt = grep_defaults;
+
 	opt->repo = repo;
 	opt->prefix = prefix;
 	opt->prefix_length = (prefix && *prefix) ? strlen(prefix) : 0;
 	opt->pattern_tail = &opt->pattern_list;
 	opt->header_tail = &opt->header_list;
-
-	opt->only_matching = def->only_matching;
-	opt->color = def->color;
-	opt->extended_regexp_option = def->extended_regexp_option;
-	opt->pattern_type_option = def->pattern_type_option;
-	opt->linenum = def->linenum;
-	opt->columnnum = def->columnnum;
-	opt->max_depth = def->max_depth;
-	opt->pathname = def->pathname;
-	opt->relative = def->relative;
-	opt->output = def->output;
-
-	for (i = 0; i < NR_GREP_COLORS; i++)
-		color_set(opt->colors[i], def->colors[i]);
 }
 
 void grep_destroy(void)

grep.h

@@ -170,7 +170,6 @@ struct grep_opt {
 	void *output_priv;
 };
 
-void init_grep_defaults(struct repository *);
 int grep_config(const char *var, const char *value, void *);
 void grep_init(struct grep_opt *, struct repository *repo, const char *prefix);
 void grep_destroy(void);

revision.c

@@ -1827,7 +1827,6 @@ void repo_init_revisions(struct repository *r,
 	revs->commit_format = CMIT_FMT_DEFAULT;
 	revs->expand_tabs_in_log_default = 8;
 
-	init_grep_defaults(revs->repo);
 	grep_init(&revs->grep_filter, revs->repo, prefix);
 	revs->grep_filter.status_only = 1;