[CF 6054] v2 - let ALTER COLUMN SET DATA TYPE cope with POLICY dependency

This branch was automatically generated by a robot using patches from an
email thread registered at:

https://commitfest.postgresql.org/patch/6054

The branch will be overwritten each time a new patch version is posted to
the thread, and also periodically to check for bitrot caused by changes
on the master branch.

Patch(es): https://www.postgresql.org/message-id/CACJufxGPcBzdL9T6Qh=OFecN8zqxuU0QXfYF8F3WYV=uzwYCdA@mail.gmail.com
Author(s): Jian He

Author: Commitfest Bot

src/backend/commands/policy.c

@@ -24,15 +24,18 @@
 #include "catalog/namespace.h"
 #include "catalog/objectaccess.h"
 #include "catalog/pg_authid.h"
+#include "catalog/pg_depend.h"
 #include "catalog/pg_policy.h"
 #include "catalog/pg_type.h"
+#include "commands/comment.h"
 #include "commands/policy.h"
 #include "miscadmin.h"
 #include "nodes/pg_list.h"
 #include "parser/parse_clause.h"
 #include "parser/parse_collate.h"
 #include "parser/parse_node.h"
 #include "parser/parse_relation.h"
+#include "parser/parse_utilcmd.h"
 #include "rewrite/rewriteManip.h"
 #include "rewrite/rowsecurity.h"
 #include "utils/acl.h"
@@ -566,7 +569,7 @@ RemoveRoleFromObjectPolicy(Oid roleid, Oid classid, Oid policy_id)
  * stmt - the CreatePolicyStmt that describes the policy to create.
  */
 ObjectAddress
-CreatePolicy(CreatePolicyStmt *stmt)
+CreatePolicy(CreatePolicyStmt *stmt, const char *queryString)
 {
 	Relation	pg_policy_rel;
 	Oid			policy_id;
@@ -576,8 +579,7 @@ CreatePolicy(CreatePolicyStmt *stmt)
 	Datum	   *role_oids;
 	int			nitems = 0;
 	ArrayType  *role_ids;
-	ParseState *qual_pstate;
-	ParseState *with_check_pstate;
+	ParseState *pstate;
 	ParseNamespaceItem *nsitem;
 	Node	   *qual;
 	Node	   *with_check_qual;
@@ -615,10 +617,6 @@ CreatePolicy(CreatePolicyStmt *stmt)
 	role_oids = policy_role_list_to_array(stmt->roles, &nitems);
 	role_ids = construct_array_builtin(role_oids, nitems, OIDOID);
 
-	/* Parse the supplied clause */
-	qual_pstate = make_parsestate(NULL);
-	with_check_pstate = make_parsestate(NULL);
-
 	/* zero-clear */
 	memset(values, 0, sizeof(values));
 	memset(isnull, 0, sizeof(isnull));
@@ -628,35 +626,23 @@ CreatePolicy(CreatePolicyStmt *stmt)
 										0,
 										RangeVarCallbackForPolicy,
 										stmt);
+	if (!stmt->transformed)
+		stmt = transformPolicyStmt(table_id, stmt, queryString);
 
-	/* Open target_table to build quals. No additional lock is necessary. */
-	target_table = relation_open(table_id, NoLock);
+	qual = stmt->qual;
+	with_check_qual = stmt->with_check;
 
-	/* Add for the regular security quals */
-	nsitem = addRangeTableEntryForRelation(qual_pstate, target_table,
-										   AccessShareLock,
-										   NULL, false, false);
-	addNSItemToQuery(qual_pstate, nsitem, false, true, true);
+	/* we'll need the pstate->rtable for recordDependencyOnExpr */
+	pstate = make_parsestate(NULL);
+	pstate->p_sourcetext = queryString;
 
-	/* Add for the with-check quals */
-	nsitem = addRangeTableEntryForRelation(with_check_pstate, target_table,
+	/* No additional lock is necessary. */
+	target_table = relation_open(table_id, NoLock);
+
+	nsitem = addRangeTableEntryForRelation(pstate, target_table,
 										   AccessShareLock,
 										   NULL, false, false);
-	addNSItemToQuery(with_check_pstate, nsitem, false, true, true);
-
-	qual = transformWhereClause(qual_pstate,
-								stmt->qual,
-								EXPR_KIND_POLICY,
-								"POLICY");
-
-	with_check_qual = transformWhereClause(with_check_pstate,
-										   stmt->with_check,
-										   EXPR_KIND_POLICY,
-										   "POLICY");
-
-	/* Fix up collation information */
-	assign_expr_collations(qual_pstate, qual);
-	assign_expr_collations(with_check_pstate, with_check_qual);
+	addNSItemToQuery(pstate, nsitem, false, true, true);
 
 	/* Open pg_policy catalog */
 	pg_policy_rel = table_open(PolicyRelationId, RowExclusiveLock);
@@ -724,11 +710,11 @@ CreatePolicy(CreatePolicyStmt *stmt)
 
 	recordDependencyOn(&myself, &target, DEPENDENCY_AUTO);
 
-	recordDependencyOnExpr(&myself, qual, qual_pstate->p_rtable,
+	recordDependencyOnExpr(&myself, qual, pstate->p_rtable,
 						   DEPENDENCY_NORMAL);
 
 	recordDependencyOnExpr(&myself, with_check_qual,
-						   with_check_pstate->p_rtable, DEPENDENCY_NORMAL);
+						   pstate->p_rtable, DEPENDENCY_NORMAL);
 
 	/* Register role dependencies */
 	target.classId = AuthIdRelationId;
@@ -749,12 +735,16 @@ CreatePolicy(CreatePolicyStmt *stmt)
 
 	/* Clean up. */
 	heap_freetuple(policy_tuple);
-	free_parsestate(qual_pstate);
-	free_parsestate(with_check_pstate);
+	free_parsestate(pstate);
 	systable_endscan(sscan);
 	relation_close(target_table, NoLock);
 	table_close(pg_policy_rel, RowExclusiveLock);
 
+	/* Add any requested comment */
+	if (stmt->polcomment != NULL)
+		CreateComments(policy_id, PolicyRelationId, 0,
+					   stmt->polcomment);
+
 	return myself;
 }
 
@@ -1277,3 +1267,55 @@ relation_has_policies(Relation rel)
 
 	return ret;
 }
+
+/*
+ * PoliciesGetRelations -
+ * Collect all relations this policy depends on.
+ * The policy's check qual or qual may reference other relations, we include
+ * those as well.
+ */
+List *
+PoliciesGetRelations(Oid policyId)
+{
+	List	   *result = NIL;
+	Relation	depRel;
+	ScanKeyData key[2];
+	SysScanDesc depScan;
+	HeapTuple	depTup;
+
+	/*
+	 * We scan pg_depend to find those things that policy being depended on.
+	 */
+	depRel = table_open(DependRelationId, AccessShareLock);
+
+	ScanKeyInit(&key[0],
+				Anum_pg_depend_classid,
+				BTEqualStrategyNumber, F_OIDEQ,
+				ObjectIdGetDatum(PolicyRelationId));
+	ScanKeyInit(&key[1],
+				Anum_pg_depend_objid,
+				BTEqualStrategyNumber, F_OIDEQ,
+				ObjectIdGetDatum(policyId));
+
+	depScan = systable_beginscan(depRel, DependDependerIndexId, true,
+								 NULL, 2, key);
+	while (HeapTupleIsValid(depTup = systable_getnext(depScan)))
+	{
+		Form_pg_depend pg_depend = (Form_pg_depend) GETSTRUCT(depTup);
+
+		/* Prepend oid of the relation with this policy. */
+		if (pg_depend->refclassid == RelationRelationId)
+		{
+			if (pg_depend->deptype == DEPENDENCY_AUTO)
+				result = lcons_oid(pg_depend->refobjid, result);
+			else
+				result = lappend_oid(result, pg_depend->refobjid);
+		}
+	}
+	systable_endscan(depScan);
+
+	relation_close(depRel, AccessShareLock);
+
+	Assert(result != NIL);
+	return result;
+}