From d4350df06cfeb0d9d5d7fe99b898c1a7ef237c97 Mon Sep 17 00:00:00 2001
From: Sami Imseih <simseih@amazon.com>
Date: Thu, 13 Mar 2025 16:15:59 -0500
Subject: [PATCH 1/1] Add a handler to validate an EXPLAIN option defined by an
 extension.

---
 src/backend/commands/explain_state.c | 28 +++++++++++++++++++++++++++-
 src/include/commands/explain_state.h | 11 ++++++++++-
 2 files changed, 37 insertions(+), 2 deletions(-)

diff --git a/src/backend/commands/explain_state.c b/src/backend/commands/explain_state.c
index 8e6eea20ba8..a052355f3c5 100644
--- a/src/backend/commands/explain_state.c
+++ b/src/backend/commands/explain_state.c
@@ -198,6 +198,14 @@ ParseExplainOptionList(ExplainState *es, List *options, ParseState *pstate)
 
 	/* if the summary was not set explicitly, set default value */
 	es->summary = (summary_set) ? es->summary : es->analyze;
+
+	/* Validate the extension options */
+	foreach(lc, options)
+	{
+		DefElem    *opt = (DefElem *) lfirst(lc);
+
+		ValidateExtensionExplainOption(es, opt);
+	}
 }
 
 /*
@@ -320,7 +328,7 @@ ApplyExtensionExplainOption(ExplainState *es, DefElem *opt, ParseState *pstate)
 		if (strcmp(ExplainExtensionOptionArray[i].option_name,
 				   opt->defname) == 0)
 		{
-			ExplainExtensionOptionArray[i].option_handler(es, opt, pstate);
+			ExplainExtensionOptionArray[i].option_handler.apply(es, opt, pstate);
 			return true;
 		}
 	}
@@ -328,6 +336,24 @@ ApplyExtensionExplainOption(ExplainState *es, DefElem *opt, ParseState *pstate)
 	return false;
 }
 
+/*
+ * Validate an EXPLAIN option registered by an extension.
+ *
+ * Should only be called after ApplyExtensionExplainOption.
+ */
+void
+ValidateExtensionExplainOption(ExplainState *es, DefElem *opt)
+{
+	for (int i = 0; i < ExplainExtensionOptionsAssigned; ++i)
+	{
+		if (strcmp(ExplainExtensionOptionArray[i].option_name,
+				   opt->defname) == 0)
+		{
+			ExplainExtensionOptionArray[i].option_handler.validate(es, opt);
+		}
+	}
+}
+
 /*
  * Map the name of an EXPLAIN extension to an integer ID.
  *
diff --git a/src/include/commands/explain_state.h b/src/include/commands/explain_state.h
index 6c161bfb615..6850d4c06b4 100644
--- a/src/include/commands/explain_state.h
+++ b/src/include/commands/explain_state.h
@@ -76,7 +76,15 @@ typedef struct ExplainState
 	int			extension_state_allocated;
 } ExplainState;
 
-typedef void (*ExplainOptionHandler) (ExplainState *, DefElem *, ParseState *);
+typedef void (*ExplainOptionApply) (ExplainState *, DefElem *, ParseState *);
+typedef void (*ExplainOptionValidate) (ExplainState *, DefElem *);
+
+
+typedef struct ExplainOptionHandler
+{
+	ExplainOptionApply apply;
+	ExplainOptionValidate validate;
+} ExplainOptionHandler;
 
 extern ExplainState *NewExplainState(void);
 extern void ParseExplainOptionList(ExplainState *es, List *options,
@@ -92,5 +100,6 @@ extern void RegisterExtensionExplainOption(const char *option_name,
 										   ExplainOptionHandler handler);
 extern bool ApplyExtensionExplainOption(ExplainState *es, DefElem *opt,
 										ParseState *pstate);
+extern void ValidateExtensionExplainOption(ExplainState *es, DefElem *opt);
 
 #endif							/* EXPLAIN_STATE_H */
-- 
2.39.5 (Apple Git-154)