Support opfamily members in get_object_address

In the spirit of 890192e99af and 4464303405f: have get_object_address
understand individual pg_amop and pg_amproc objects.  There is no way to
refer to such objects directly in the grammar -- rather, they are almost
always considered an integral part of the opfamily that contains them.
(The only case that deals with them individually is ALTER OPERATOR
FAMILY ADD/DROP, which carries the opfamily address separately and thus
does not need it to be part of each added/dropped element's address.)
In event triggers it becomes possible to become involved with individual
amop/amproc elements, and this commit enables pg_get_object_address to
do so as well.

To make the overall coding simpler, this commit also slightly changes
the get_object_address representation for opclasses and opfamilies:
instead of having the AM name in the objargs array, I moved it as the
first element of the objnames array.  This enables the new code to use
objargs for the type names used by pg_amop and pg_amproc.

Reviewed by: Stephen Frost

2 files changed, 18 insertions, 8 deletions

diff --git a/src/backend/commands/dropcmds.c b/src/backend/commands/dropcmds.c
index e5185ba34d2..a1b0d4d2fa2 100644
--- a/src/backend/commands/dropcmds.c
+++ b/src/backend/commands/dropcmds.c
@@ -406,19 +406,27 @@ does_not_exist_skipping(ObjectType objtype, List *objname, List *objargs)
 			name = NameListToString(objname);
 			break;
 		case OBJECT_OPCLASS:
-			if (!schema_does_not_exist_skipping(objname, &msg, &name))
 			{
-				msg = gettext_noop("operator class \"%s\" does not exist for access method \"%s\", skipping");
-				name = NameListToString(objname);
-				args = strVal(linitial(objargs));
+				List *opcname = list_copy_tail(objname, 1);
+
+				if (!schema_does_not_exist_skipping(opcname, &msg, &name))
+				{
+					msg = gettext_noop("operator class \"%s\" does not exist for access method \"%s\", skipping");
+					name = NameListToString(opcname);
+					args = strVal(linitial(objname));
+				}
 			}
 			break;
 		case OBJECT_OPFAMILY:
-			if (!schema_does_not_exist_skipping(objname, &msg, &name))
 			{
-				msg = gettext_noop("operator family \"%s\" does not exist for access method \"%s\", skipping");
-				name = NameListToString(objname);
-				args = strVal(linitial(objargs));
+				List *opfname = list_copy_tail(objname, 1);
+
+				if (!schema_does_not_exist_skipping(opfname, &msg, &name))
+				{
+					msg = gettext_noop("operator family \"%s\" does not exist for access method \"%s\", skipping");
+					name = NameListToString(opfname);
+					args = strVal(linitial(objname));
+				}
 			}
 			break;
 		default:
diff --git a/src/backend/commands/event_trigger.c b/src/backend/commands/event_trigger.c
index 3fec57ea237..4bcc327a2b5 100644
--- a/src/backend/commands/event_trigger.c
+++ b/src/backend/commands/event_trigger.c
@@ -1060,6 +1060,8 @@ EventTriggerSupportsObjectType(ObjectType obtype)
 			/* no support for event triggers on event triggers */
 			return false;
 		case OBJECT_AGGREGATE:
+		case OBJECT_AMOP:
+		case OBJECT_AMPROC:
 		case OBJECT_ATTRIBUTE:
 		case OBJECT_CAST:
 		case OBJECT_COLUMN: