Subject: [PATCH 1/2] parse-options: introduce die_for_required_opt()

From: Siddharth Shrimali <[email-masked]>
Date: Wed, 3 Jun 2026 16:40:43 +0530

Introduce a new helper function die_for_required_opt() to check if a
given option is present without its required prerequisite option.

This provides a centralized API for handling simple option dependencies
(i.e., X requires Y), matching the style of the existing mutual-exclusion
helpers like die_for_incompatible_opt{2,3,4}().

Suggested-by: Christian Couder <[email-masked]>
Signed-off-by: Siddharth Shrimali <[email-masked]>
---
 parse-options.c | 7 +++++++
 parse-options.h | 3 +++
 2 files changed, 10 insertions(+)

diff --git a/parse-options.c b/parse-options.c
index a676da86f5..e100f9a0c1 100644
--- a/parse-options.c
+++ b/parse-options.c
@@ -1558,3 +1558,10 @@ void die_for_incompatible_opt4(int opt1, const char *opt1_name,
 		break;
 	}
 }
+
+void die_for_required_opt(int opt1, const char *opt1_name,
+			  int opt2, const char *opt2_name)
+{
+	if (opt1 && !opt2)
+		die(_("the option '%s' requires '%s'"), opt1_name, opt2_name);
+}
diff --git a/parse-options.h b/parse-options.h
index 0d1f738f8d..99dc53325d 100644
--- a/parse-options.h
+++ b/parse-options.h
@@ -460,6 +460,9 @@ static inline void die_for_incompatible_opt2(int opt1, const char *opt1_name,
 				  0, "");
 }
 
+void die_for_required_opt(int opt1, const char *opt1_name,
+			  int opt2, const char *opt2_name);
+
 /*
  * Use these assertions for callbacks that expect to be called with NONEG and
  * NOARG respectively, and do not otherwise handle the "unset" and "arg"
-- 
2.54.0