grep API: call grep_config() after grep_init()

The grep_init() function used the odd pattern of initializing the
passed-in "struct grep_opt" with a statically defined "grep_defaults"
struct, which would be modified in-place when we invoked
grep_config().

So we effectively (b) initialized config, (a) then defaults, (c)
followed by user options. Usually those are ordered as "a", "b" and
"c" instead.

As the comments being removed here show the previous behavior needed
to be carefully explained as we'd potentially share the populated
configuration among different instances of grep_init(). In practice we
didn't do that, but now that it can't be a concern anymore let's
remove those comments.

This does not change the behavior of any of the configuration
variables or options. That would have been the case if we didn't move
around the grep_config() call in "builtin/log.c". But now that we call
"grep_config" after "git_log_config" and "git_format_config" we'll
need to pass in the already initialized "struct grep_opt *".

See 6ba9bb7 (grep: copy struct in one fell swoop, 2020-11-29) and
7687a05 (grep: move the configuration parsing logic to grep.[ch],
2012-10-09) for the commits that added the comments.

The memcpy() pattern here will be optimized away and follows the
convention of other *_init() functions. See 5726a6b (*.c *_init():
define in terms of corresponding *_INIT macro, 2021-07-01).

Signed-off-by: Ævar Arnfjörð Bjarmason <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: avar

builtin/grep.c

@@ -285,7 +285,7 @@ static int wait_all(void)
 
 static int grep_cmd_config(const char *var, const char *value, void *cb)
 {
-	int st = grep_config(var, value, NULL);
+	int st = grep_config(var, value, cb);
 	if (git_color_default_config(var, value, NULL) < 0)
 		st = -1;
 
@@ -966,8 +966,8 @@ int cmd_grep(int argc, const char **argv, const char *prefix)
 	};
 	grep_prefix = prefix;
 
-	git_config(grep_cmd_config, NULL);
 	grep_init(&opt, the_repository);
+	git_config(grep_cmd_config, &opt);
 
 	/*
 	 * If there is no -- then the paths must exist in the working

builtin/log.c

@@ -520,8 +520,6 @@ static int git_log_config(const char *var, const char *value, void *cb)
 		return 0;
 	}
 
-	if (grep_config(var, value, cb) < 0)
-		return -1;
 	if (git_gpg_config(var, value, cb) < 0)
 		return -1;
 	return git_diff_ui_config(var, value, cb);
@@ -536,6 +534,8 @@ int cmd_whatchanged(int argc, const char **argv, const char *prefix)
 	git_config(git_log_config, NULL);
 
 	repo_init_revisions(the_repository, &rev, prefix);
+	git_config(grep_config, &rev.grep_filter);
+
 	rev.diff = 1;
 	rev.simplify_history = 0;
 	memset(&opt, 0, sizeof(opt));
@@ -650,6 +650,8 @@ int cmd_show(int argc, const char **argv, const char *prefix)
 
 	memset(&match_all, 0, sizeof(match_all));
 	repo_init_revisions(the_repository, &rev, prefix);
+	git_config(grep_config, &rev.grep_filter);
+
 	rev.diff = 1;
 	rev.always_show_header = 1;
 	rev.no_walk = 1;
@@ -733,6 +735,8 @@ int cmd_log_reflog(int argc, const char **argv, const char *prefix)
 
 	repo_init_revisions(the_repository, &rev, prefix);
 	init_reflog_walk(&rev.reflog_info);
+	git_config(grep_config, &rev.grep_filter);
+
 	rev.verbose_header = 1;
 	memset(&opt, 0, sizeof(opt));
 	opt.def = "HEAD";
@@ -766,6 +770,8 @@ int cmd_log(int argc, const char **argv, const char *prefix)
 	git_config(git_log_config, NULL);
 
 	repo_init_revisions(the_repository, &rev, prefix);
+	git_config(grep_config, &rev.grep_filter);
+
 	rev.always_show_header = 1;
 	memset(&opt, 0, sizeof(opt));
 	opt.def = "HEAD";
@@ -1848,10 +1854,13 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 	extra_hdr.strdup_strings = 1;
 	extra_to.strdup_strings = 1;
 	extra_cc.strdup_strings = 1;
+
 	init_log_defaults();
 	init_display_notes(&notes_opt);
 	git_config(git_format_config, NULL);
 	repo_init_revisions(the_repository, &rev, prefix);
+	git_config(grep_config, &rev.grep_filter);
+
 	rev.show_notes = show_notes;
 	memcpy(&rev.notes_opt, &notes_opt, sizeof(notes_opt));
 	rev.commit_format = CMIT_FMT_EMAIL;

grep.c

@@ -19,27 +19,6 @@ 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] = GIT_COLOR_MAGENTA,
-		[GREP_COLOR_FUNCTION] = "",
-		[GREP_COLOR_LINENO] = GIT_COLOR_GREEN,
-		[GREP_COLOR_COLUMNNO] = GIT_COLOR_GREEN,
-		[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,
-};
-
 static const char *color_grep_slots[] = {
 	[GREP_COLOR_CONTEXT]	    = "context",
 	[GREP_COLOR_FILENAME]	    = "filename",
@@ -75,20 +54,12 @@ define_list_config_array_extra(color_grep_slots, {"match"});
  */
 int grep_config(const char *var, const char *value, void *cb)
 {
-	struct grep_opt *opt = &grep_defaults;
+	struct grep_opt *opt = cb;
 	const char *slot;
 
 	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;
@@ -134,14 +105,10 @@ int grep_config(const char *var, const char *value, void *cb)
 	return 0;
 }
 
-/*
- * Initialize one instance of grep_opt and copy the
- * default values from the template we read the configuration
- * information in an earlier call to git_config(grep_config).
- */
 void grep_init(struct grep_opt *opt, struct repository *repo)
 {
-	*opt = grep_defaults;
+	struct grep_opt blank = GREP_OPT_INIT;
+	memcpy(opt, &blank, sizeof(*opt));
 
 	opt->repo = repo;
 	opt->pattern_tail = &opt->pattern_list;

grep.h

@@ -179,6 +179,27 @@ struct grep_opt {
 	void *output_priv;
 };
 
+#define GREP_OPT_INIT { \
+	.relative = 1, \
+	.pathname = 1, \
+	.max_depth = -1, \
+	.pattern_type_option = GREP_PATTERN_TYPE_UNSPECIFIED, \
+	.colors = { \
+		[GREP_COLOR_CONTEXT] = "", \
+		[GREP_COLOR_FILENAME] = GIT_COLOR_MAGENTA, \
+		[GREP_COLOR_FUNCTION] = "", \
+		[GREP_COLOR_LINENO] = GIT_COLOR_GREEN, \
+		[GREP_COLOR_COLUMNNO] = GIT_COLOR_GREEN, \
+		[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, \
+}
+
 int grep_config(const char *var, const char *value, void *);
 void grep_init(struct grep_opt *, struct repository *repo);
 void grep_commit_pattern_type(enum grep_pattern_type, struct grep_opt *opt);