Fix maintenance hazards caused by ill-considered use of default: cases.

Remove default cases from assorted switches over ObjectClass and some
related enum types, so that we'll get compiler warnings when someone
adds a new enum value without accounting for it in all these places.

In passing, re-order some switch cases as needed to match the declaration
of enum ObjectClass.  OK, that's just neatnik-ism, but I dislike code
that looks like it was assembled with the help of a dartboard.

Discussion: https://postgr.es/m/20170512221010.nglatgt5azzdxjlj@alvherre.pgsql

src/backend/catalog/dependency.c

@@ -1204,6 +1204,10 @@ doDeletion(const ObjectAddress *object, int flags)
 			RemoveSchemaById(object->objectId);
 			break;
 
+		case OCLASS_STATISTIC_EXT:
+			RemoveStatisticsById(object->objectId);
+			break;
+
 		case OCLASS_TSPARSER:
 			RemoveTSParserById(object->objectId);
 			break;
@@ -1265,13 +1269,20 @@ doDeletion(const ObjectAddress *object, int flags)
 			DropTransformById(object->objectId);
 			break;
 
-		case OCLASS_STATISTIC_EXT:
-			RemoveStatisticsById(object->objectId);
+			/*
+			 * These global object types are not supported here.
+			 */
+		case OCLASS_ROLE:
+		case OCLASS_DATABASE:
+		case OCLASS_TBLSPACE:
+		case OCLASS_SUBSCRIPTION:
+			elog(ERROR, "global objects cannot be deleted by doDeletion");
 			break;
 
-		default:
-			elog(ERROR, "unrecognized object class: %u",
-				 object->classId);
+			/*
+			 * There's intentionally no default: case here; we want the
+			 * compiler to warn if a new OCLASS hasn't been handled above.
+			 */
 	}
 }
 

src/backend/commands/alter.c

@@ -543,7 +543,8 @@ ExecAlterObjectSchemaStmt(AlterObjectSchemaStmt *stmt,
  * so it only needs to cover object types that can be members of an
  * extension, and it doesn't have to deal with certain special cases
  * such as not wanting to process array types --- those should never
- * be direct members of an extension anyway.
+ * be direct members of an extension anyway.  Nonetheless, we insist
+ * on listing all OCLASS types in the switch.
  *
  * Returns the OID of the object's previous namespace, or InvalidOid if
  * object doesn't have a schema.
@@ -578,12 +579,13 @@ AlterObjectNamespace_oid(Oid classId, Oid objid, Oid nspOid,
 			oldNspOid = AlterTypeNamespace_oid(objid, nspOid, objsMoved);
 			break;
 
+		case OCLASS_PROC:
 		case OCLASS_COLLATION:
 		case OCLASS_CONVERSION:
 		case OCLASS_OPERATOR:
 		case OCLASS_OPCLASS:
 		case OCLASS_OPFAMILY:
-		case OCLASS_PROC:
+		case OCLASS_STATISTIC_EXT:
 		case OCLASS_TSPARSER:
 		case OCLASS_TSDICT:
 		case OCLASS_TSTEMPLATE:
@@ -600,8 +602,38 @@ AlterObjectNamespace_oid(Oid classId, Oid objid, Oid nspOid,
 			}
 			break;
 
-		default:
+		case OCLASS_CAST:
+		case OCLASS_CONSTRAINT:
+		case OCLASS_DEFAULT:
+		case OCLASS_LANGUAGE:
+		case OCLASS_LARGEOBJECT:
+		case OCLASS_AM:
+		case OCLASS_AMOP:
+		case OCLASS_AMPROC:
+		case OCLASS_REWRITE:
+		case OCLASS_TRIGGER:
+		case OCLASS_SCHEMA:
+		case OCLASS_ROLE:
+		case OCLASS_DATABASE:
+		case OCLASS_TBLSPACE:
+		case OCLASS_FDW:
+		case OCLASS_FOREIGN_SERVER:
+		case OCLASS_USER_MAPPING:
+		case OCLASS_DEFACL:
+		case OCLASS_EXTENSION:
+		case OCLASS_EVENT_TRIGGER:
+		case OCLASS_POLICY:
+		case OCLASS_PUBLICATION:
+		case OCLASS_PUBLICATION_REL:
+		case OCLASS_SUBSCRIPTION:
+		case OCLASS_TRANSFORM:
+			/* ignore object types that don't have schema-qualified names */
 			break;
+
+			/*
+			 * There's intentionally no default: case here; we want the
+			 * compiler to warn if a new OCLASS hasn't been handled above.
+			 */
 	}
 
 	return oldNspOid;

src/backend/commands/event_trigger.c

@@ -1122,8 +1122,15 @@ EventTriggerSupportsObjectType(ObjectType obtype)
 		case OBJECT_USER_MAPPING:
 		case OBJECT_VIEW:
 			return true;
+
+			/*
+			 * There's intentionally no default: case here; we want the
+			 * compiler to warn if a new ObjectType hasn't been handled above.
+			 */
 	}
-	return true;
+
+	/* Shouldn't get here, but if we do, say "no support" */
+	return false;
 }
 
 /*
@@ -1155,12 +1162,13 @@ EventTriggerSupportsObjectClass(ObjectClass objclass)
 		case OCLASS_OPERATOR:
 		case OCLASS_OPCLASS:
 		case OCLASS_OPFAMILY:
+		case OCLASS_AM:
 		case OCLASS_AMOP:
 		case OCLASS_AMPROC:
 		case OCLASS_REWRITE:
 		case OCLASS_TRIGGER:
 		case OCLASS_SCHEMA:
-		case OCLASS_TRANSFORM:
+		case OCLASS_STATISTIC_EXT:
 		case OCLASS_TSPARSER:
 		case OCLASS_TSDICT:
 		case OCLASS_TSTEMPLATE:
@@ -1171,15 +1179,20 @@ EventTriggerSupportsObjectClass(ObjectClass objclass)
 		case OCLASS_DEFACL:
 		case OCLASS_EXTENSION:
 		case OCLASS_POLICY:
-		case OCLASS_AM:
 		case OCLASS_PUBLICATION:
 		case OCLASS_PUBLICATION_REL:
 		case OCLASS_SUBSCRIPTION:
-		case OCLASS_STATISTIC_EXT:
+		case OCLASS_TRANSFORM:
 			return true;
+
+			/*
+			 * There's intentionally no default: case here; we want the
+			 * compiler to warn if a new OCLASS hasn't been handled above.
+			 */
 	}
 
-	return true;
+	/* Shouldn't get here, but if we do, say "no support" */
+	return false;
 }
 
 bool
@@ -1204,10 +1217,15 @@ EventTriggerSupportsGrantObjectType(GrantObjectType objtype)
 		case ACL_OBJECT_NAMESPACE:
 		case ACL_OBJECT_TYPE:
 			return true;
-		default:
-			Assert(false);
-			return true;
+
+			/*
+			 * There's intentionally no default: case here; we want the
+			 * compiler to warn if a new ACL class hasn't been handled above.
+			 */
 	}
+
+	/* Shouldn't get here, but if we do, say "no support" */
+	return false;
 }
 
 /*
@@ -2229,35 +2247,50 @@ stringify_grantobjtype(GrantObjectType objtype)
 			return "TABLESPACE";
 		case ACL_OBJECT_TYPE:
 			return "TYPE";
-		default:
-			elog(ERROR, "unrecognized type %d", objtype);
-			return "???";		/* keep compiler quiet */
 	}
+
+	elog(ERROR, "unrecognized grant object type: %d", (int) objtype);
+	return "???";		/* keep compiler quiet */
 }
 
 /*
  * Return the GrantObjectType as a string; as above, but use the spelling
- * in ALTER DEFAULT PRIVILEGES commands instead.
+ * in ALTER DEFAULT PRIVILEGES commands instead.  Generally this is just
+ * the plural.
  */
 static const char *
 stringify_adefprivs_objtype(GrantObjectType objtype)
 {
 	switch (objtype)
 	{
+		case ACL_OBJECT_COLUMN:
+			return "COLUMNS";
 		case ACL_OBJECT_RELATION:
 			return "TABLES";
-			break;
-		case ACL_OBJECT_FUNCTION:
-			return "FUNCTIONS";
-			break;
 		case ACL_OBJECT_SEQUENCE:
 			return "SEQUENCES";
-			break;
+		case ACL_OBJECT_DATABASE:
+			return "DATABASES";
+		case ACL_OBJECT_DOMAIN:
+			return "DOMAINS";
+		case ACL_OBJECT_FDW:
+			return "FOREIGN DATA WRAPPERS";
+		case ACL_OBJECT_FOREIGN_SERVER:
+			return "FOREIGN SERVERS";
+		case ACL_OBJECT_FUNCTION:
+			return "FUNCTIONS";
+		case ACL_OBJECT_LANGUAGE:
+			return "LANGUAGES";
+		case ACL_OBJECT_LARGEOBJECT:
+			return "LARGE OBJECTS";
+		case ACL_OBJECT_NAMESPACE:
+			return "SCHEMAS";
+		case ACL_OBJECT_TABLESPACE:
+			return "TABLESPACES";
 		case ACL_OBJECT_TYPE:
 			return "TYPES";
-			break;
-		default:
-			elog(ERROR, "unrecognized type %d", objtype);
-			return "???";		/* keep compiler quiet */
 	}
+
+	elog(ERROR, "unrecognized grant object type: %d", (int) objtype);
+	return "???";		/* keep compiler quiet */
 }