0002-Introduce-pg_proc.proissafe-and-func_is_safe.patch

From 7831b2c571784a614dd4ee4b48730187b0c0a8d1 Mon Sep 17 00:00:00 2001
From: Nikita Glukhov <n.gluhov@postgrespro.ru>
Date: Wed, 31 Aug 2022 23:02:06 +0300
Subject: [PATCH 2/5] Introduce pg_proc.proissafe and func_is_safe()

---
 src/backend/utils/cache/lsyscache.c | 19 +++++++++++++++++++
 src/include/catalog/pg_proc.h       |  3 +++
 src/include/utils/lsyscache.h       |  1 +
 3 files changed, 23 insertions(+)

diff --git a/src/backend/utils/cache/lsyscache.c b/src/backend/utils/cache/lsyscache.c
index a16a63f4957..ff3005077b2 100644
--- a/src/backend/utils/cache/lsyscache.c
+++ b/src/backend/utils/cache/lsyscache.c
@@ -1830,6 +1830,25 @@ get_func_leakproof(Oid funcid)
 	return result;
 }
 
+/*
+ * func_is_safe
+ *		Given procedure id, return the function's proissafe flag.
+ */
+bool
+func_is_safe(Oid funcid)
+{
+	HeapTuple	tp;
+	bool		result;
+
+	tp = SearchSysCache1(PROCOID, ObjectIdGetDatum(funcid));
+	if (!HeapTupleIsValid(tp))
+		elog(ERROR, "cache lookup failed for function %u", funcid);
+
+	result = ((Form_pg_proc) GETSTRUCT(tp))->proissafe;
+	ReleaseSysCache(tp);
+	return result;
+}
+
 /*
  * get_func_support
  *
diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
index 76310d4cc9a..2ae8942b014 100644
--- a/src/include/catalog/pg_proc.h
+++ b/src/include/catalog/pg_proc.h
@@ -70,6 +70,9 @@ CATALOG(pg_proc,1255,ProcedureRelationId) BKI_BOOTSTRAP BKI_ROWTYPE_OID(81,Proce
 	/* returns a set? */
 	bool		proretset BKI_DEFAULT(f);
 
+	/* can return error info through FuncCallError instead of throwing it? */
+	bool		proissafe BKI_DEFAULT(f);
+
 	/* see PROVOLATILE_ categories below */
 	char		provolatile BKI_DEFAULT(i);
 
diff --git a/src/include/utils/lsyscache.h b/src/include/utils/lsyscache.h
index 50f02883052..c66365fdf2c 100644
--- a/src/include/utils/lsyscache.h
+++ b/src/include/utils/lsyscache.h
@@ -130,6 +130,7 @@ extern char func_volatile(Oid funcid);
 extern char func_parallel(Oid funcid);
 extern char get_func_prokind(Oid funcid);
 extern bool get_func_leakproof(Oid funcid);
+extern bool func_is_safe(Oid funcid);
 extern RegProcedure get_func_support(Oid funcid);
 extern Oid	get_relname_relid(const char *relname, Oid relnamespace);
 extern char *get_rel_name(Oid relid);
-- 
2.25.1