Fix handling of CREATE DOMAIN with GENERATED constraint syntax

Stuff like

    CREATE DOMAIN foo AS int CONSTRAINT cc GENERATED ALWAYS AS (2) STORED

is not supported for domains, but the parser allows it, because it's
the same syntax as for table constraints.  But CreateDomain() did not
explicitly handle all ConstrType values, so the above would get an
internal error like

    ERROR:  unrecognized constraint subtype: 4

Fix that by providing a user-facing error message for all ConstrType
values.  Also, remove the switch default case, so future additions to
ConstrType are caught.

Reported-by: Jian He <jian.universality@gmail.com>
Discussion: https://www.postgresql.org/message-id/CACJufxF8fmM=Dbm4pDFuV_nKGz2-No0k4YifhrF3-rjXTWJM3w@mail.gmail.com

diff --git a/src/backend/commands/typecmds.c b/src/backend/commands/typecmds.c
index 971a8a1ebc5c06431d10563ce6d2aa39ab60cfb7..da591c0922b490475002469290d3bf34ff22cc74 100644 (file)
--- a/src/backend/commands/typecmds.c
+++ b/src/backend/commands/typecmds.c
@@ -1011,10 +1011,14 @@ DefineDomain(CreateDomainStmt *stmt)
                                                 errmsg("specifying constraint deferrability not supported for domains")));
                                break;
 
-                       default:
-                               elog(ERROR, "unrecognized constraint subtype: %d",
-                                        (int) constr->contype);
+                       case CONSTR_GENERATED:
+                       case CONSTR_IDENTITY:
+                               ereport(ERROR,
+                                               (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+                                                errmsg("specifying GENERATED not supported for domains")));
                                break;
+
+                               /* no default, to let compiler warn about missing case */
                }
        }