Subject: [RFC PATCH v3 5/6] parse-options: parse into argv_array

From: Emily Shaffer <[email-masked]>
Date: Tue, 28 Jul 2020 15:24:54 -0700

parse-options already knows how to read into a string_list, and it knows
how to read into an argv_array as a passthrough (that is, including the
argument as well as its value). string_list and argv_array serve similar
purposes but are somewhat painful to convert between; so, let's teach
parse-options to read values of string arguments directly into an
argv_array without preserving the argument name.

This is useful if collecting generic arguments to pass through to
another command, for example, 'git hook run --arg "--quiet" --arg
"--format=pretty" some-hook'. The resulting argv_array would contain
{ "--quiet", "--format=pretty" }.

The implementation is based on that of OPT_STRING_LIST.

Signed-off-by: Emily Shaffer <[email-masked]>
---
 Documentation/technical/api-parse-options.txt |  5 +++++
 parse-options-cb.c                            | 16 ++++++++++++++++
 parse-options.h                               |  4 ++++
 3 files changed, 25 insertions(+)

diff --git a/Documentation/technical/api-parse-options.txt b/Documentation/technical/api-parse-options.txt
index 2e2e7c10c6..1e97343338 100644
--- a/Documentation/technical/api-parse-options.txt
+++ b/Documentation/technical/api-parse-options.txt
@@ -173,6 +173,11 @@ There are some macros to easily define options:
 	The string argument is stored as an element in `string_list`.
 	Use of `--no-option` will clear the list of preceding values.
 
+`OPT_ARGV_ARRAY(short, long, &struct argv_array, arg_str, description)`::
+	Introduce an option with a string argument.
+	The string argument is stored as an element in `argv_array`.
+	Use of `--no-option` will clear the list of preceding values.
+
 `OPT_INTEGER(short, long, &int_var, description)`::
 	Introduce an option with integer argument.
 	The integer is put into `int_var`.
diff --git a/parse-options-cb.c b/parse-options-cb.c
index 86cd393013..94c2dd397a 100644
--- a/parse-options-cb.c
+++ b/parse-options-cb.c
@@ -205,6 +205,22 @@ int parse_opt_string_list(const struct option *opt, const char *arg, int unset)
 	return 0;
 }
 
+int parse_opt_argv_array(const struct option *opt, const char *arg, int unset)
+{
+	struct argv_array *v = opt->value;
+
+	if (unset) {
+		argv_array_clear(v);
+		return 0;
+	}
+
+	if (!arg)
+		return -1;
+
+	argv_array_push(v, arg);
+	return 0;
+}
+
 int parse_opt_noop_cb(const struct option *opt, const char *arg, int unset)
 {
 	return 0;
diff --git a/parse-options.h b/parse-options.h
index 46af942093..e2e2de75c8 100644
--- a/parse-options.h
+++ b/parse-options.h
@@ -177,6 +177,9 @@ struct option {
 #define OPT_STRING_LIST(s, l, v, a, h) \
 				    { OPTION_CALLBACK, (s), (l), (v), (a), \
 				      (h), 0, &parse_opt_string_list }
+#define OPT_ARGV_ARRAY(s, l, v, a, h) \
+				    { OPTION_CALLBACK, (s), (l), (v), (a), \
+				      (h), 0, &parse_opt_argv_array }
 #define OPT_UYN(s, l, v, h)         { OPTION_CALLBACK, (s), (l), (v), NULL, \
 				      (h), PARSE_OPT_NOARG, &parse_opt_tertiary }
 #define OPT_EXPIRY_DATE(s, l, v, h) \
@@ -296,6 +299,7 @@ int parse_opt_commits(const struct option *, const char *, int);
 int parse_opt_commit(const struct option *, const char *, int);
 int parse_opt_tertiary(const struct option *, const char *, int);
 int parse_opt_string_list(const struct option *, const char *, int);
+int parse_opt_argv_array(const struct option *, const char *, int);
 int parse_opt_noop_cb(const struct option *, const char *, int);
 enum parse_opt_result parse_opt_unknown_cb(struct parse_opt_ctx_t *ctx,
 					   const struct option *,
-- 
2.28.0.rc0.142.g3c755180ce-goog