From fab9d9f34979650a63b3be59ea69962923ac6617 Mon Sep 17 00:00:00 2001
From: "vignesh.c" <vignesh21@gmail.com>
Date: Thu, 27 Oct 2022 14:00:46 +0530
Subject: [PATCH v3] Tab completion for ALTER FUNCTION/PROCEDURE/ROUTINE.

Tab completion for ALTER FUNCTION/PROCEDURE/ROUTINE action was missing,
added the tab completion for the same.
---
 src/bin/psql/tab-complete.c | 57 ++++++++++++++++++++++++++++++++++---
 1 file changed, 53 insertions(+), 4 deletions(-)

diff --git a/src/bin/psql/tab-complete.c b/src/bin/psql/tab-complete.c
index 13014f074f..4d0bbc034d 100644
--- a/src/bin/psql/tab-complete.c
+++ b/src/bin/psql/tab-complete.c
@@ -1149,6 +1149,16 @@ static const SchemaQuery Query_for_trigger_of_table = {
 "CREATE", "CONNECT", "TEMPORARY", "EXECUTE", "USAGE", "SET", "ALTER SYSTEM", \
 "ALL"
 
+/* ALTER PROCEDURE options */
+#define Alter_procedure_options \
+"DEPENDS ON EXTENSION", "EXTERNAL SECURITY", "NO DEPENDS ON EXTENSION", \
+"OWNER TO", "RENAME TO", "RESET", "SECURITY", "SET"
+
+/* ALTER ROUTINE options */
+#define Alter_routine_options \
+Alter_procedure_options, "COST", "IMMUTABLE", "LEAKPROOF", "NOT LEAKPROOF", \
+"PARALLEL", "ROWS", "STABLE", "VOLATILE"
+
 /*
  * These object types were introduced later than our support cutoff of
  * server version 9.2.  We use the VersionedQuery infrastructure so that
@@ -1812,12 +1822,51 @@ psql_completion(const char *text, int start, int end)
 		else
 			COMPLETE_WITH_FUNCTION_ARG(prev2_wd);
 	}
-	/* ALTER FUNCTION,PROCEDURE,ROUTINE <name> (...) */
-	else if (Matches("ALTER", "FUNCTION|PROCEDURE|ROUTINE", MatchAny, MatchAny))
+	/* ALTER FUNCTION <name> (...) */
+	else if (Matches("ALTER", "FUNCTION", MatchAny, MatchAny))
+	{
+		if (ends_with(prev_wd, ')'))
+			COMPLETE_WITH(Alter_routine_options, "CALLED ON NULL INPUT",
+						  "RETURNS NULL ON NULL INPUT", "STRICT", "SUPPORT");
+		else
+			COMPLETE_WITH_FUNCTION_ARG(prev2_wd);
+	}
+	/* ALTER FUNCTION|ROUTINE <name> (...) PARALLEL */
+	else if (Matches("ALTER", "FUNCTION|ROUTINE", MatchAny, MatchAny,
+			 "PARALLEL"))
+		COMPLETE_WITH("RESTRICTED", "SAFE", "UNSAFE");
+	/*
+	 * ALTER FUNCTION|PROCEDURE|ROUTINE <name> (...)
+	 * [EXTERNAL] SECURITY
+	 */
+	else if (Matches("ALTER", "FUNCTION|PROCEDURE|ROUTINE", MatchAny, MatchAny,
+					 "SECURITY") ||
+			 Matches("ALTER", "FUNCTION|PROCEDURE|ROUTINE", MatchAny, MatchAny,
+					 "EXTERNAL", "SECURITY"))
+		COMPLETE_WITH("DEFINER" ,"INVOKER");
+	/* ALTER FUNCTION|PROCEDURE|ROUTINE <name> (...) RESET */
+	else if (Matches("ALTER", "FUNCTION|PROCEDURE|ROUTINE", MatchAny, MatchAny,
+					 "RESET"))
+		COMPLETE_WITH_QUERY_VERBATIM_PLUS(Query_for_list_of_set_vars,
+										  "ALL");
+	/* ALTER FUNCTION|PROCEDURE|ROUTINE <name> (...) SET */
+	else if (Matches("ALTER", "FUNCTION|PROCEDURE|ROUTINE", MatchAny, MatchAny,
+					 "SET"))
+		COMPLETE_WITH_QUERY_VERBATIM_PLUS(Query_for_list_of_set_vars,
+										  "SCHEMA");
+	/* ALTER PROCEDURE <name> (...) */
+	else if (Matches("ALTER", "PROCEDURE", MatchAny, MatchAny))
+	{
+		if (ends_with(prev_wd, ')'))
+			COMPLETE_WITH(Alter_procedure_options);
+		else
+			COMPLETE_WITH_FUNCTION_ARG(prev2_wd);
+	}
+	/* ALTER ROUTINE <name> (...) */
+	else if (Matches("ALTER", "ROUTINE", MatchAny, MatchAny))
 	{
 		if (ends_with(prev_wd, ')'))
-			COMPLETE_WITH("OWNER TO", "RENAME TO", "SET SCHEMA",
-						  "DEPENDS ON EXTENSION", "NO DEPENDS ON EXTENSION");
+			COMPLETE_WITH(Alter_routine_options);
 		else
 			COMPLETE_WITH_FUNCTION_ARG(prev2_wd);
 	}
-- 
2.34.1