Allow arbitrary levels of analyze/rewriting

This has been saved for the 7.3 release:

http://candle.pha.pa.us/cgi-bin/pgpatches2

---------------------------------------------------------------------------

Fernando Nasser wrote:

Hi,

This patch will allow arbitrary levels of analyze / rewriting
by making the static variables extra_before and extra_after
automatic so we can use recursion.

It gets much easier to generate extra commands now, and one can rest
assured that the extra commands will be properly analyzed/rewritten.

Without this patch, if a command produced by transformation tries to
use these static lists their first contents would be lost with
unpredictable results. I know I could fix this by just using nconc()
instead of assignments, but the resulting order of the commands would
not be exactly what one could expect.

--
Fernando Nasser
Red Hat Canada Ltd. E-Mail: fnasser@redhat.com
2323 Yonge Street, Suite #300
Toronto, Ontario M4P 2C9

Index: src/backend/parser/analyze.c
===================================================================
RCS file: /projects/cvsroot/pgsql/src/backend/parser/analyze.c,v
retrieving revision 1.213
diff -c -p -r1.213 analyze.c
*** src/backend/parser/analyze.c	2002/01/03 23:21:31	1.213
--- src/backend/parser/analyze.c	2002/02/12 15:35:58
*************** typedef struct
*** 64,80 ****
} CreateStmtContext;

! static Query *transformStmt(ParseState *pstate, Node *stmt);
static Query *transformDeleteStmt(ParseState *pstate, DeleteStmt *stmt);
! static Query *transformInsertStmt(ParseState *pstate, InsertStmt *stmt);
static Query *transformIndexStmt(ParseState *pstate, IndexStmt *stmt);
! static Query *transformRuleStmt(ParseState *query, RuleStmt *stmt);
static Query *transformSelectStmt(ParseState *pstate, SelectStmt *stmt);
static Query *transformSetOperationStmt(ParseState *pstate, SelectStmt *stmt);
static Node *transformSetOperationTree(ParseState *pstate, SelectStmt *stmt);
static Query *transformUpdateStmt(ParseState *pstate, UpdateStmt *stmt);
! static Query *transformCreateStmt(ParseState *pstate, CreateStmt *stmt);
! static Query *transformAlterTableStmt(ParseState *pstate, AlterTableStmt *stmt);
static void transformColumnDefinition(ParseState *pstate,
CreateStmtContext *cxt,
ColumnDef *column);
--- 64,85 ----
} CreateStmtContext;

! static Query *transformStmt(ParseState *pstate, Node *stmt,
! List **extras_before, List **extras_after);
static Query *transformDeleteStmt(ParseState *pstate, DeleteStmt *stmt);
! static Query *transformInsertStmt(ParseState *pstate, InsertStmt *stmt,
! List **extras_before, List **extras_after);
static Query *transformIndexStmt(ParseState *pstate, IndexStmt *stmt);
! static Query *transformRuleStmt(ParseState *query, RuleStmt *stmt,
! List **extras_before, List **extras_after);
static Query *transformSelectStmt(ParseState *pstate, SelectStmt *stmt);
static Query *transformSetOperationStmt(ParseState *pstate, SelectStmt *stmt);
static Node *transformSetOperationTree(ParseState *pstate, SelectStmt *stmt);
static Query *transformUpdateStmt(ParseState *pstate, UpdateStmt *stmt);
! static Query *transformCreateStmt(ParseState *pstate, CreateStmt *stmt,
! List **extras_before, List **extras_after);
! static Query *transformAlterTableStmt(ParseState *pstate, AlterTableStmt *stmt,
! List **extras_before, List **extras_after);
static void transformColumnDefinition(ParseState *pstate,
CreateStmtContext *cxt,
ColumnDef *column);
*************** static Oid transformFkeyGetColType(Creat
*** 101,109 ****
static void release_pstate_resources(ParseState *pstate);
static FromExpr *makeFromExpr(List *fromlist, Node *quals);

- /* kluge to return extra info from transformCreateStmt() */
- static List *extras_before;
- static List *extras_after;

/*
--- 106,111 ----
*************** parse_analyze(Node *parseTree, ParseStat
*** 121,137 ****
List	   *result = NIL;
ParseState *pstate = make_parsestate(parentParseState);
Query	   *query;

! extras_before = extras_after = NIL;
!
! query = transformStmt(pstate, parseTree);
release_pstate_resources(pstate);

while (extras_before != NIL)
{
! result = lappend(result,
! transformStmt(pstate, lfirst(extras_before)));
! release_pstate_resources(pstate);
extras_before = lnext(extras_before);
}

--- 123,138 ----
List	   *result = NIL;
ParseState *pstate = make_parsestate(parentParseState);
Query	   *query;
+ 	/* Lists to return extra commands from transformation */
+ 	List *extras_before = NIL;
+ 	List *extras_after = NIL;

! query = transformStmt(pstate, parseTree, &extras_before, &extras_after);
release_pstate_resources(pstate);

while (extras_before != NIL)
{
! result = nconc(result, parse_analyze(lfirst(extras_before), pstate));
extras_before = lnext(extras_before);
}

*************** parse_analyze(Node *parseTree, ParseStat
*** 139,147 ****

while (extras_after != NIL)
{
! result = lappend(result,
! transformStmt(pstate, lfirst(extras_after)));
! release_pstate_resources(pstate);
extras_after = lnext(extras_after);
}

--- 140,146 ----

while (extras_after != NIL)
{
! result = nconc(result, parse_analyze(lfirst(extras_after), pstate));
extras_after = lnext(extras_after);
}

*************** release_pstate_resources(ParseState *pst
*** 164,170 ****
* transform a Parse tree into a Query tree.
*/
static Query *
! transformStmt(ParseState *pstate, Node *parseTree)
{
Query *result = NULL;

--- 163,170 ----
*	  transform a Parse tree into a Query tree.
*/
static Query *
! transformStmt(ParseState *pstate, Node *parseTree,
! 			  List **extras_before,	List **extras_after)
{
Query	   *result = NULL;

*************** transformStmt(ParseState *pstate, Node *
*** 174,180 ****
* Non-optimizable statements
*/
case T_CreateStmt:
! result = transformCreateStmt(pstate, (CreateStmt *) parseTree);
break;

case T_IndexStmt:
--- 174,181 ----
* Non-optimizable statements
*/
case T_CreateStmt:
! 			result = transformCreateStmt(pstate, (CreateStmt *) parseTree,
! 									extras_before, extras_after);
break;

case T_IndexStmt:
*************** transformStmt(ParseState *pstate, Node *
*** 182,195 ****
break;

case T_RuleStmt:
! result = transformRuleStmt(pstate, (RuleStmt *) parseTree);
break;

case T_ViewStmt:
{
ViewStmt *n = (ViewStmt *) parseTree;

! n->query = transformStmt(pstate, (Node *) n->query);

/*
* If a list of column names was given, run through and
--- 183,198 ----
break;

case T_RuleStmt:
! result = transformRuleStmt(pstate, (RuleStmt *) parseTree,
! extras_before, extras_after);
break;

case T_ViewStmt:
{
ViewStmt *n = (ViewStmt *) parseTree;

! n->query = transformStmt(pstate, (Node *) n->query,
! extras_before, extras_after);

/*
* If a list of column names was given, run through and
*************** transformStmt(ParseState *pstate, Node *
*** 239,258 ****

result = makeNode(Query);
result->commandType = CMD_UTILITY;
! n->query = transformStmt(pstate, (Node *) n->query);
result->utilityStmt = (Node *) parseTree;
}
break;

case T_AlterTableStmt:
! result = transformAlterTableStmt(pstate, (AlterTableStmt *) parseTree);
break;

/*
* Optimizable statements
*/
case T_InsertStmt:
! result = transformInsertStmt(pstate, (InsertStmt *) parseTree);
break;

case T_DeleteStmt:
--- 242,264 ----

result = makeNode(Query);
result->commandType = CMD_UTILITY;
! n->query = transformStmt(pstate, (Node *) n->query,
! extras_before, extras_after);
result->utilityStmt = (Node *) parseTree;
}
break;

case T_AlterTableStmt:
! result = transformAlterTableStmt(pstate, (AlterTableStmt *) parseTree,
! extras_before, extras_after);
break;

/*
* Optimizable statements
*/
case T_InsertStmt:
! result = transformInsertStmt(pstate, (InsertStmt *) parseTree,
! extras_before, extras_after);
break;

case T_DeleteStmt:
*************** transformDeleteStmt(ParseState *pstate, 
*** 337,343 ****
*	  transform an Insert Statement
*/
static Query *
! transformInsertStmt(ParseState *pstate, InsertStmt *stmt)
{
Query	   *qry = makeNode(Query);
List	   *sub_rtable;
--- 343,350 ----
*	  transform an Insert Statement
*/
static Query *
! transformInsertStmt(ParseState *pstate, InsertStmt *stmt,
! 					List **extras_before, List **extras_after)
{
Query	   *qry = makeNode(Query);
List	   *sub_rtable;
*************** transformInsertStmt(ParseState *pstate, 
*** 402,408 ****
sub_pstate->p_rtable = sub_rtable;
sub_pstate->p_namespace = sub_namespace;

! selectQuery = transformStmt(sub_pstate, stmt->selectStmt);

release_pstate_resources(sub_pstate);
pfree(sub_pstate);
--- 409,420 ----
sub_pstate->p_rtable = sub_rtable;
sub_pstate->p_namespace = sub_namespace;

! /*
! * Note: we are not expecting that extras_before and extras_after
! * are going to be used by the transformation of the SELECT statement.
! */
! selectQuery = transformStmt(sub_pstate, stmt->selectStmt,
! extras_before, extras_after);

release_pstate_resources(sub_pstate);
pfree(sub_pstate);
*************** CreateIndexName(char *table_name, char *
*** 658,664 ****
*	  - thomas 1997-12-02
*/
static Query *
! transformCreateStmt(ParseState *pstate, CreateStmt *stmt)
{
CreateStmtContext cxt;
Query	   *q;
--- 670,677 ----
*	  - thomas 1997-12-02
*/
static Query *
! transformCreateStmt(ParseState *pstate, CreateStmt *stmt,
! 					List **extras_before, List **extras_after)
{
CreateStmtContext cxt;
Query	   *q;
*************** transformCreateStmt(ParseState *pstate, 
*** 728,735 ****
q->utilityStmt = (Node *) stmt;
stmt->tableElts = cxt.columns;
stmt->constraints = cxt.ckconstraints;
! 	extras_before = cxt.blist;
! 	extras_after = cxt.alist;

return q;
}
--- 741,748 ----
q->utilityStmt = (Node *) stmt;
stmt->tableElts = cxt.columns;
stmt->constraints = cxt.ckconstraints;
! 	*extras_before = nconc (*extras_before, cxt.blist);
! 	*extras_after = nconc (cxt.alist, *extras_after);

return q;
}
*************** transformIndexStmt(ParseState *pstate, I
*** 1668,1674 ****
*	  trees which is transformed into a list of query trees.
*/
static Query *
! transformRuleStmt(ParseState *pstate, RuleStmt *stmt)
{
Query	   *qry;
RangeTblEntry *oldrte;
--- 1681,1688 ----
*	  trees which is transformed into a list of query trees.
*/
static Query *
! transformRuleStmt(ParseState *pstate, RuleStmt *stmt,
! 				List **extras_before, List **extras_after)
{
Query	   *qry;
RangeTblEntry *oldrte;
*************** transformRuleStmt(ParseState *pstate, Ru
*** 1797,1803 ****
addRTEtoQuery(sub_pstate, newrte, false, true);

/* Transform the rule action statement */
! top_subqry = transformStmt(sub_pstate, action);

/*
* We cannot support utility-statement actions (eg NOTIFY)
--- 1811,1818 ----
addRTEtoQuery(sub_pstate, newrte, false, true);

/* Transform the rule action statement */
! top_subqry = transformStmt(sub_pstate, action,
! extras_before, extras_after);

/*
* We cannot support utility-statement actions (eg NOTIFY)
*************** transformUpdateStmt(ParseState *pstate, 
*** 2494,2500 ****
*	transform an Alter Table Statement
*/
static Query *
! transformAlterTableStmt(ParseState *pstate, AlterTableStmt *stmt)
{
CreateStmtContext cxt;
Query	   *qry;
--- 2509,2516 ----
*	transform an Alter Table Statement
*/
static Query *
! transformAlterTableStmt(ParseState *pstate, AlterTableStmt *stmt,
! 						List **extras_before, List **extras_after)
{
CreateStmtContext cxt;
Query	   *qry;
*************** transformAlterTableStmt(ParseState *psta
*** 2534,2541 ****
transformFKConstraints(pstate, &cxt);

((ColumnDef *) stmt->def)->constraints = cxt.ckconstraints;
! extras_before = cxt.blist;
! extras_after = cxt.alist;
break;

case 'C':
--- 2550,2557 ----
transformFKConstraints(pstate, &cxt);

((ColumnDef *) stmt->def)->constraints = cxt.ckconstraints;
! *extras_before = nconc(*extras_before, cxt.blist);
! *extras_after = nconc(cxt.alist, *extras_after);
break;

case 'C':
*************** transformAlterTableStmt(ParseState *psta
*** 2571,2578 ****

Assert(cxt.columns == NIL);
stmt->def = (Node *) nconc(cxt.ckconstraints, cxt.fkconstraints);
! extras_before = cxt.blist;
! extras_after = cxt.alist;
break;

default:
--- 2587,2594 ----

Assert(cxt.columns == NIL);
stmt->def = (Node *) nconc(cxt.ckconstraints, cxt.fkconstraints);
! *extras_before = nconc(*extras_before, cxt.blist);
! *extras_after = nconc(cxt.alist, *extras_after);
break;

default:

---------------------------(end of broadcast)---------------------------
TIP 5: Have you checked our extensive FAQ?

http://www.postgresql.org/users-lounge/docs/faq.html

-- 
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 853-3000
  +  If your life is a hard drive,     |  830 Blythe Avenue
  +  Christ can be your backup.        |  Drexel Hill, Pennsylvania 19026

Your patch has been added to the PostgreSQL unapplied patches list at:

http://candle.pha.pa.us/cgi-bin/pgpatches

I will try to apply it within the next 48 hours.

---------------------------------------------------------------------------

Fernando Nasser wrote:

Hi,

This patch will allow arbitrary levels of analyze / rewriting
by making the static variables extra_before and extra_after
automatic so we can use recursion.

It gets much easier to generate extra commands now, and one can rest
assured that the extra commands will be properly analyzed/rewritten.

Without this patch, if a command produced by transformation tries to
use these static lists their first contents would be lost with
unpredictable results. I know I could fix this by just using nconc()
instead of assignments, but the resulting order of the commands would
not be exactly what one could expect.

--
Fernando Nasser
Red Hat Canada Ltd. E-Mail: fnasser@redhat.com
2323 Yonge Street, Suite #300
Toronto, Ontario M4P 2C9

Index: src/backend/parser/analyze.c
===================================================================
RCS file: /projects/cvsroot/pgsql/src/backend/parser/analyze.c,v
retrieving revision 1.213
diff -c -p -r1.213 analyze.c
*** src/backend/parser/analyze.c	2002/01/03 23:21:31	1.213
--- src/backend/parser/analyze.c	2002/02/12 15:35:58
*************** typedef struct
*** 64,80 ****
} CreateStmtContext;

! static Query *transformStmt(ParseState *pstate, Node *stmt);
static Query *transformDeleteStmt(ParseState *pstate, DeleteStmt *stmt);
! static Query *transformInsertStmt(ParseState *pstate, InsertStmt *stmt);
static Query *transformIndexStmt(ParseState *pstate, IndexStmt *stmt);
! static Query *transformRuleStmt(ParseState *query, RuleStmt *stmt);
static Query *transformSelectStmt(ParseState *pstate, SelectStmt *stmt);
static Query *transformSetOperationStmt(ParseState *pstate, SelectStmt *stmt);
static Node *transformSetOperationTree(ParseState *pstate, SelectStmt *stmt);
static Query *transformUpdateStmt(ParseState *pstate, UpdateStmt *stmt);
! static Query *transformCreateStmt(ParseState *pstate, CreateStmt *stmt);
! static Query *transformAlterTableStmt(ParseState *pstate, AlterTableStmt *stmt);
static void transformColumnDefinition(ParseState *pstate,
CreateStmtContext *cxt,
ColumnDef *column);
--- 64,85 ----
} CreateStmtContext;

! static Query *transformStmt(ParseState *pstate, Node *stmt,
! List **extras_before, List **extras_after);
static Query *transformDeleteStmt(ParseState *pstate, DeleteStmt *stmt);
! static Query *transformInsertStmt(ParseState *pstate, InsertStmt *stmt,
! List **extras_before, List **extras_after);
static Query *transformIndexStmt(ParseState *pstate, IndexStmt *stmt);
! static Query *transformRuleStmt(ParseState *query, RuleStmt *stmt,
! List **extras_before, List **extras_after);
static Query *transformSelectStmt(ParseState *pstate, SelectStmt *stmt);
static Query *transformSetOperationStmt(ParseState *pstate, SelectStmt *stmt);
static Node *transformSetOperationTree(ParseState *pstate, SelectStmt *stmt);
static Query *transformUpdateStmt(ParseState *pstate, UpdateStmt *stmt);
! static Query *transformCreateStmt(ParseState *pstate, CreateStmt *stmt,
! List **extras_before, List **extras_after);
! static Query *transformAlterTableStmt(ParseState *pstate, AlterTableStmt *stmt,
! List **extras_before, List **extras_after);
static void transformColumnDefinition(ParseState *pstate,
CreateStmtContext *cxt,
ColumnDef *column);
*************** static Oid transformFkeyGetColType(Creat
*** 101,109 ****
static void release_pstate_resources(ParseState *pstate);
static FromExpr *makeFromExpr(List *fromlist, Node *quals);

- /* kluge to return extra info from transformCreateStmt() */
- static List *extras_before;
- static List *extras_after;

/*
--- 106,111 ----
*************** parse_analyze(Node *parseTree, ParseStat
*** 121,137 ****
List	   *result = NIL;
ParseState *pstate = make_parsestate(parentParseState);
Query	   *query;

! extras_before = extras_after = NIL;
!
! query = transformStmt(pstate, parseTree);
release_pstate_resources(pstate);

while (extras_before != NIL)
{
! result = lappend(result,
! transformStmt(pstate, lfirst(extras_before)));
! release_pstate_resources(pstate);
extras_before = lnext(extras_before);
}

--- 123,138 ----
List	   *result = NIL;
ParseState *pstate = make_parsestate(parentParseState);
Query	   *query;
+ 	/* Lists to return extra commands from transformation */
+ 	List *extras_before = NIL;
+ 	List *extras_after = NIL;

! query = transformStmt(pstate, parseTree, &extras_before, &extras_after);
release_pstate_resources(pstate);

while (extras_before != NIL)
{
! result = nconc(result, parse_analyze(lfirst(extras_before), pstate));
extras_before = lnext(extras_before);
}

*************** parse_analyze(Node *parseTree, ParseStat
*** 139,147 ****

while (extras_after != NIL)
{
! result = lappend(result,
! transformStmt(pstate, lfirst(extras_after)));
! release_pstate_resources(pstate);
extras_after = lnext(extras_after);
}

--- 140,146 ----

while (extras_after != NIL)
{
! result = nconc(result, parse_analyze(lfirst(extras_after), pstate));
extras_after = lnext(extras_after);
}

*************** release_pstate_resources(ParseState *pst
*** 164,170 ****
* transform a Parse tree into a Query tree.
*/
static Query *
! transformStmt(ParseState *pstate, Node *parseTree)
{
Query *result = NULL;

--- 163,170 ----
*	  transform a Parse tree into a Query tree.
*/
static Query *
! transformStmt(ParseState *pstate, Node *parseTree,
! 			  List **extras_before,	List **extras_after)
{
Query	   *result = NULL;

*************** transformStmt(ParseState *pstate, Node *
*** 174,180 ****
* Non-optimizable statements
*/
case T_CreateStmt:
! result = transformCreateStmt(pstate, (CreateStmt *) parseTree);
break;

case T_IndexStmt:
--- 174,181 ----
* Non-optimizable statements
*/
case T_CreateStmt:
! 			result = transformCreateStmt(pstate, (CreateStmt *) parseTree,
! 									extras_before, extras_after);
break;

case T_IndexStmt:
*************** transformStmt(ParseState *pstate, Node *
*** 182,195 ****
break;

case T_RuleStmt:
! result = transformRuleStmt(pstate, (RuleStmt *) parseTree);
break;

case T_ViewStmt:
{
ViewStmt *n = (ViewStmt *) parseTree;

! n->query = transformStmt(pstate, (Node *) n->query);

/*
* If a list of column names was given, run through and
--- 183,198 ----
break;

case T_RuleStmt:
! result = transformRuleStmt(pstate, (RuleStmt *) parseTree,
! extras_before, extras_after);
break;

case T_ViewStmt:
{
ViewStmt *n = (ViewStmt *) parseTree;

! n->query = transformStmt(pstate, (Node *) n->query,
! extras_before, extras_after);

/*
* If a list of column names was given, run through and
*************** transformStmt(ParseState *pstate, Node *
*** 239,258 ****

result = makeNode(Query);
result->commandType = CMD_UTILITY;
! n->query = transformStmt(pstate, (Node *) n->query);
result->utilityStmt = (Node *) parseTree;
}
break;

case T_AlterTableStmt:
! result = transformAlterTableStmt(pstate, (AlterTableStmt *) parseTree);
break;

/*
* Optimizable statements
*/
case T_InsertStmt:
! result = transformInsertStmt(pstate, (InsertStmt *) parseTree);
break;

case T_DeleteStmt:
--- 242,264 ----

result = makeNode(Query);
result->commandType = CMD_UTILITY;
! n->query = transformStmt(pstate, (Node *) n->query,
! extras_before, extras_after);
result->utilityStmt = (Node *) parseTree;
}
break;

case T_AlterTableStmt:
! result = transformAlterTableStmt(pstate, (AlterTableStmt *) parseTree,
! extras_before, extras_after);
break;

/*
* Optimizable statements
*/
case T_InsertStmt:
! result = transformInsertStmt(pstate, (InsertStmt *) parseTree,
! extras_before, extras_after);
break;

case T_DeleteStmt:
*************** transformDeleteStmt(ParseState *pstate, 
*** 337,343 ****
*	  transform an Insert Statement
*/
static Query *
! transformInsertStmt(ParseState *pstate, InsertStmt *stmt)
{
Query	   *qry = makeNode(Query);
List	   *sub_rtable;
--- 343,350 ----
*	  transform an Insert Statement
*/
static Query *
! transformInsertStmt(ParseState *pstate, InsertStmt *stmt,
! 					List **extras_before, List **extras_after)
{
Query	   *qry = makeNode(Query);
List	   *sub_rtable;
*************** transformInsertStmt(ParseState *pstate, 
*** 402,408 ****
sub_pstate->p_rtable = sub_rtable;
sub_pstate->p_namespace = sub_namespace;

! selectQuery = transformStmt(sub_pstate, stmt->selectStmt);

release_pstate_resources(sub_pstate);
pfree(sub_pstate);
--- 409,420 ----
sub_pstate->p_rtable = sub_rtable;
sub_pstate->p_namespace = sub_namespace;

! /*
! * Note: we are not expecting that extras_before and extras_after
! * are going to be used by the transformation of the SELECT statement.
! */
! selectQuery = transformStmt(sub_pstate, stmt->selectStmt,
! extras_before, extras_after);

release_pstate_resources(sub_pstate);
pfree(sub_pstate);
*************** CreateIndexName(char *table_name, char *
*** 658,664 ****
*	  - thomas 1997-12-02
*/
static Query *
! transformCreateStmt(ParseState *pstate, CreateStmt *stmt)
{
CreateStmtContext cxt;
Query	   *q;
--- 670,677 ----
*	  - thomas 1997-12-02
*/
static Query *
! transformCreateStmt(ParseState *pstate, CreateStmt *stmt,
! 					List **extras_before, List **extras_after)
{
CreateStmtContext cxt;
Query	   *q;
*************** transformCreateStmt(ParseState *pstate, 
*** 728,735 ****
q->utilityStmt = (Node *) stmt;
stmt->tableElts = cxt.columns;
stmt->constraints = cxt.ckconstraints;
! 	extras_before = cxt.blist;
! 	extras_after = cxt.alist;

return q;
}
--- 741,748 ----
q->utilityStmt = (Node *) stmt;
stmt->tableElts = cxt.columns;
stmt->constraints = cxt.ckconstraints;
! 	*extras_before = nconc (*extras_before, cxt.blist);
! 	*extras_after = nconc (cxt.alist, *extras_after);

return q;
}
*************** transformIndexStmt(ParseState *pstate, I
*** 1668,1674 ****
*	  trees which is transformed into a list of query trees.
*/
static Query *
! transformRuleStmt(ParseState *pstate, RuleStmt *stmt)
{
Query	   *qry;
RangeTblEntry *oldrte;
--- 1681,1688 ----
*	  trees which is transformed into a list of query trees.
*/
static Query *
! transformRuleStmt(ParseState *pstate, RuleStmt *stmt,
! 				List **extras_before, List **extras_after)
{
Query	   *qry;
RangeTblEntry *oldrte;
*************** transformRuleStmt(ParseState *pstate, Ru
*** 1797,1803 ****
addRTEtoQuery(sub_pstate, newrte, false, true);

/* Transform the rule action statement */
! top_subqry = transformStmt(sub_pstate, action);

/*
* We cannot support utility-statement actions (eg NOTIFY)
--- 1811,1818 ----
addRTEtoQuery(sub_pstate, newrte, false, true);

/* Transform the rule action statement */
! top_subqry = transformStmt(sub_pstate, action,
! extras_before, extras_after);

/*
* We cannot support utility-statement actions (eg NOTIFY)
*************** transformUpdateStmt(ParseState *pstate, 
*** 2494,2500 ****
*	transform an Alter Table Statement
*/
static Query *
! transformAlterTableStmt(ParseState *pstate, AlterTableStmt *stmt)
{
CreateStmtContext cxt;
Query	   *qry;
--- 2509,2516 ----
*	transform an Alter Table Statement
*/
static Query *
! transformAlterTableStmt(ParseState *pstate, AlterTableStmt *stmt,
! 						List **extras_before, List **extras_after)
{
CreateStmtContext cxt;
Query	   *qry;
*************** transformAlterTableStmt(ParseState *psta
*** 2534,2541 ****
transformFKConstraints(pstate, &cxt);

((ColumnDef *) stmt->def)->constraints = cxt.ckconstraints;
! extras_before = cxt.blist;
! extras_after = cxt.alist;
break;

case 'C':
--- 2550,2557 ----
transformFKConstraints(pstate, &cxt);

((ColumnDef *) stmt->def)->constraints = cxt.ckconstraints;
! *extras_before = nconc(*extras_before, cxt.blist);
! *extras_after = nconc(cxt.alist, *extras_after);
break;

case 'C':
*************** transformAlterTableStmt(ParseState *psta
*** 2571,2578 ****

Assert(cxt.columns == NIL);
stmt->def = (Node *) nconc(cxt.ckconstraints, cxt.fkconstraints);
! extras_before = cxt.blist;
! extras_after = cxt.alist;
break;

default:
--- 2587,2594 ----

Assert(cxt.columns == NIL);
stmt->def = (Node *) nconc(cxt.ckconstraints, cxt.fkconstraints);
! *extras_before = nconc(*extras_before, cxt.blist);
! *extras_after = nconc(cxt.alist, *extras_after);
break;

default:

---------------------------(end of broadcast)---------------------------
TIP 5: Have you checked our extensive FAQ?

http://www.postgresql.org/users-lounge/docs/faq.html

-- 
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 853-3000
  +  If your life is a hard drive,     |  830 Blythe Avenue
  +  Christ can be your backup.        |  Drexel Hill, Pennsylvania 19026

Patch applied. Thanks.

---------------------------------------------------------------------------

Fernando Nasser wrote:

Hi,

This patch will allow arbitrary levels of analyze / rewriting
by making the static variables extra_before and extra_after
automatic so we can use recursion.

It gets much easier to generate extra commands now, and one can rest
assured that the extra commands will be properly analyzed/rewritten.

Without this patch, if a command produced by transformation tries to
use these static lists their first contents would be lost with
unpredictable results. I know I could fix this by just using nconc()
instead of assignments, but the resulting order of the commands would
not be exactly what one could expect.

--
Fernando Nasser
Red Hat Canada Ltd. E-Mail: fnasser@redhat.com
2323 Yonge Street, Suite #300
Toronto, Ontario M4P 2C9

Index: src/backend/parser/analyze.c
===================================================================
RCS file: /projects/cvsroot/pgsql/src/backend/parser/analyze.c,v
retrieving revision 1.213
diff -c -p -r1.213 analyze.c
*** src/backend/parser/analyze.c	2002/01/03 23:21:31	1.213
--- src/backend/parser/analyze.c	2002/02/12 15:35:58
*************** typedef struct
*** 64,80 ****
} CreateStmtContext;

! static Query *transformStmt(ParseState *pstate, Node *stmt);
static Query *transformDeleteStmt(ParseState *pstate, DeleteStmt *stmt);
! static Query *transformInsertStmt(ParseState *pstate, InsertStmt *stmt);
static Query *transformIndexStmt(ParseState *pstate, IndexStmt *stmt);
! static Query *transformRuleStmt(ParseState *query, RuleStmt *stmt);
static Query *transformSelectStmt(ParseState *pstate, SelectStmt *stmt);
static Query *transformSetOperationStmt(ParseState *pstate, SelectStmt *stmt);
static Node *transformSetOperationTree(ParseState *pstate, SelectStmt *stmt);
static Query *transformUpdateStmt(ParseState *pstate, UpdateStmt *stmt);
! static Query *transformCreateStmt(ParseState *pstate, CreateStmt *stmt);
! static Query *transformAlterTableStmt(ParseState *pstate, AlterTableStmt *stmt);
static void transformColumnDefinition(ParseState *pstate,
CreateStmtContext *cxt,
ColumnDef *column);
--- 64,85 ----
} CreateStmtContext;

! static Query *transformStmt(ParseState *pstate, Node *stmt,
! List **extras_before, List **extras_after);
static Query *transformDeleteStmt(ParseState *pstate, DeleteStmt *stmt);
! static Query *transformInsertStmt(ParseState *pstate, InsertStmt *stmt,
! List **extras_before, List **extras_after);
static Query *transformIndexStmt(ParseState *pstate, IndexStmt *stmt);
! static Query *transformRuleStmt(ParseState *query, RuleStmt *stmt,
! List **extras_before, List **extras_after);
static Query *transformSelectStmt(ParseState *pstate, SelectStmt *stmt);
static Query *transformSetOperationStmt(ParseState *pstate, SelectStmt *stmt);
static Node *transformSetOperationTree(ParseState *pstate, SelectStmt *stmt);
static Query *transformUpdateStmt(ParseState *pstate, UpdateStmt *stmt);
! static Query *transformCreateStmt(ParseState *pstate, CreateStmt *stmt,
! List **extras_before, List **extras_after);
! static Query *transformAlterTableStmt(ParseState *pstate, AlterTableStmt *stmt,
! List **extras_before, List **extras_after);
static void transformColumnDefinition(ParseState *pstate,
CreateStmtContext *cxt,
ColumnDef *column);
*************** static Oid transformFkeyGetColType(Creat
*** 101,109 ****
static void release_pstate_resources(ParseState *pstate);
static FromExpr *makeFromExpr(List *fromlist, Node *quals);

- /* kluge to return extra info from transformCreateStmt() */
- static List *extras_before;
- static List *extras_after;

/*
--- 106,111 ----
*************** parse_analyze(Node *parseTree, ParseStat
*** 121,137 ****
List	   *result = NIL;
ParseState *pstate = make_parsestate(parentParseState);
Query	   *query;

! extras_before = extras_after = NIL;
!
! query = transformStmt(pstate, parseTree);
release_pstate_resources(pstate);

while (extras_before != NIL)
{
! result = lappend(result,
! transformStmt(pstate, lfirst(extras_before)));
! release_pstate_resources(pstate);
extras_before = lnext(extras_before);
}

--- 123,138 ----
List	   *result = NIL;
ParseState *pstate = make_parsestate(parentParseState);
Query	   *query;
+ 	/* Lists to return extra commands from transformation */
+ 	List *extras_before = NIL;
+ 	List *extras_after = NIL;

! query = transformStmt(pstate, parseTree, &extras_before, &extras_after);
release_pstate_resources(pstate);

while (extras_before != NIL)
{
! result = nconc(result, parse_analyze(lfirst(extras_before), pstate));
extras_before = lnext(extras_before);
}

*************** parse_analyze(Node *parseTree, ParseStat
*** 139,147 ****

while (extras_after != NIL)
{
! result = lappend(result,
! transformStmt(pstate, lfirst(extras_after)));
! release_pstate_resources(pstate);
extras_after = lnext(extras_after);
}

--- 140,146 ----

while (extras_after != NIL)
{
! result = nconc(result, parse_analyze(lfirst(extras_after), pstate));
extras_after = lnext(extras_after);
}

*************** release_pstate_resources(ParseState *pst
*** 164,170 ****
* transform a Parse tree into a Query tree.
*/
static Query *
! transformStmt(ParseState *pstate, Node *parseTree)
{
Query *result = NULL;

--- 163,170 ----
*	  transform a Parse tree into a Query tree.
*/
static Query *
! transformStmt(ParseState *pstate, Node *parseTree,
! 			  List **extras_before,	List **extras_after)
{
Query	   *result = NULL;

*************** transformStmt(ParseState *pstate, Node *
*** 174,180 ****
* Non-optimizable statements
*/
case T_CreateStmt:
! result = transformCreateStmt(pstate, (CreateStmt *) parseTree);
break;

case T_IndexStmt:
--- 174,181 ----
* Non-optimizable statements
*/
case T_CreateStmt:
! 			result = transformCreateStmt(pstate, (CreateStmt *) parseTree,
! 									extras_before, extras_after);
break;

case T_IndexStmt:
*************** transformStmt(ParseState *pstate, Node *
*** 182,195 ****
break;

case T_RuleStmt:
! result = transformRuleStmt(pstate, (RuleStmt *) parseTree);
break;

case T_ViewStmt:
{
ViewStmt *n = (ViewStmt *) parseTree;

! n->query = transformStmt(pstate, (Node *) n->query);

/*
* If a list of column names was given, run through and
--- 183,198 ----
break;

case T_RuleStmt:
! result = transformRuleStmt(pstate, (RuleStmt *) parseTree,
! extras_before, extras_after);
break;

case T_ViewStmt:
{
ViewStmt *n = (ViewStmt *) parseTree;

! n->query = transformStmt(pstate, (Node *) n->query,
! extras_before, extras_after);

/*
* If a list of column names was given, run through and
*************** transformStmt(ParseState *pstate, Node *
*** 239,258 ****

result = makeNode(Query);
result->commandType = CMD_UTILITY;
! n->query = transformStmt(pstate, (Node *) n->query);
result->utilityStmt = (Node *) parseTree;
}
break;

case T_AlterTableStmt:
! result = transformAlterTableStmt(pstate, (AlterTableStmt *) parseTree);
break;

/*
* Optimizable statements
*/
case T_InsertStmt:
! result = transformInsertStmt(pstate, (InsertStmt *) parseTree);
break;

case T_DeleteStmt:
--- 242,264 ----

result = makeNode(Query);
result->commandType = CMD_UTILITY;
! n->query = transformStmt(pstate, (Node *) n->query,
! extras_before, extras_after);
result->utilityStmt = (Node *) parseTree;
}
break;

case T_AlterTableStmt:
! result = transformAlterTableStmt(pstate, (AlterTableStmt *) parseTree,
! extras_before, extras_after);
break;

/*
* Optimizable statements
*/
case T_InsertStmt:
! result = transformInsertStmt(pstate, (InsertStmt *) parseTree,
! extras_before, extras_after);
break;

case T_DeleteStmt:
*************** transformDeleteStmt(ParseState *pstate, 
*** 337,343 ****
*	  transform an Insert Statement
*/
static Query *
! transformInsertStmt(ParseState *pstate, InsertStmt *stmt)
{
Query	   *qry = makeNode(Query);
List	   *sub_rtable;
--- 343,350 ----
*	  transform an Insert Statement
*/
static Query *
! transformInsertStmt(ParseState *pstate, InsertStmt *stmt,
! 					List **extras_before, List **extras_after)
{
Query	   *qry = makeNode(Query);
List	   *sub_rtable;
*************** transformInsertStmt(ParseState *pstate, 
*** 402,408 ****
sub_pstate->p_rtable = sub_rtable;
sub_pstate->p_namespace = sub_namespace;

! selectQuery = transformStmt(sub_pstate, stmt->selectStmt);

release_pstate_resources(sub_pstate);
pfree(sub_pstate);
--- 409,420 ----
sub_pstate->p_rtable = sub_rtable;
sub_pstate->p_namespace = sub_namespace;

! /*
! * Note: we are not expecting that extras_before and extras_after
! * are going to be used by the transformation of the SELECT statement.
! */
! selectQuery = transformStmt(sub_pstate, stmt->selectStmt,
! extras_before, extras_after);

release_pstate_resources(sub_pstate);
pfree(sub_pstate);
*************** CreateIndexName(char *table_name, char *
*** 658,664 ****
*	  - thomas 1997-12-02
*/
static Query *
! transformCreateStmt(ParseState *pstate, CreateStmt *stmt)
{
CreateStmtContext cxt;
Query	   *q;
--- 670,677 ----
*	  - thomas 1997-12-02
*/
static Query *
! transformCreateStmt(ParseState *pstate, CreateStmt *stmt,
! 					List **extras_before, List **extras_after)
{
CreateStmtContext cxt;
Query	   *q;
*************** transformCreateStmt(ParseState *pstate, 
*** 728,735 ****
q->utilityStmt = (Node *) stmt;
stmt->tableElts = cxt.columns;
stmt->constraints = cxt.ckconstraints;
! 	extras_before = cxt.blist;
! 	extras_after = cxt.alist;

return q;
}
--- 741,748 ----
q->utilityStmt = (Node *) stmt;
stmt->tableElts = cxt.columns;
stmt->constraints = cxt.ckconstraints;
! 	*extras_before = nconc (*extras_before, cxt.blist);
! 	*extras_after = nconc (cxt.alist, *extras_after);

return q;
}
*************** transformIndexStmt(ParseState *pstate, I
*** 1668,1674 ****
*	  trees which is transformed into a list of query trees.
*/
static Query *
! transformRuleStmt(ParseState *pstate, RuleStmt *stmt)
{
Query	   *qry;
RangeTblEntry *oldrte;
--- 1681,1688 ----
*	  trees which is transformed into a list of query trees.
*/
static Query *
! transformRuleStmt(ParseState *pstate, RuleStmt *stmt,
! 				List **extras_before, List **extras_after)
{
Query	   *qry;
RangeTblEntry *oldrte;
*************** transformRuleStmt(ParseState *pstate, Ru
*** 1797,1803 ****
addRTEtoQuery(sub_pstate, newrte, false, true);

/* Transform the rule action statement */
! top_subqry = transformStmt(sub_pstate, action);

/*
* We cannot support utility-statement actions (eg NOTIFY)
--- 1811,1818 ----
addRTEtoQuery(sub_pstate, newrte, false, true);

/* Transform the rule action statement */
! top_subqry = transformStmt(sub_pstate, action,
! extras_before, extras_after);

/*
* We cannot support utility-statement actions (eg NOTIFY)
*************** transformUpdateStmt(ParseState *pstate, 
*** 2494,2500 ****
*	transform an Alter Table Statement
*/
static Query *
! transformAlterTableStmt(ParseState *pstate, AlterTableStmt *stmt)
{
CreateStmtContext cxt;
Query	   *qry;
--- 2509,2516 ----
*	transform an Alter Table Statement
*/
static Query *
! transformAlterTableStmt(ParseState *pstate, AlterTableStmt *stmt,
! 						List **extras_before, List **extras_after)
{
CreateStmtContext cxt;
Query	   *qry;
*************** transformAlterTableStmt(ParseState *psta
*** 2534,2541 ****
transformFKConstraints(pstate, &cxt);

((ColumnDef *) stmt->def)->constraints = cxt.ckconstraints;
! extras_before = cxt.blist;
! extras_after = cxt.alist;
break;

case 'C':
--- 2550,2557 ----
transformFKConstraints(pstate, &cxt);

((ColumnDef *) stmt->def)->constraints = cxt.ckconstraints;
! *extras_before = nconc(*extras_before, cxt.blist);
! *extras_after = nconc(cxt.alist, *extras_after);
break;

case 'C':
*************** transformAlterTableStmt(ParseState *psta
*** 2571,2578 ****

Assert(cxt.columns == NIL);
stmt->def = (Node *) nconc(cxt.ckconstraints, cxt.fkconstraints);
! extras_before = cxt.blist;
! extras_after = cxt.alist;
break;

default:
--- 2587,2594 ----

Assert(cxt.columns == NIL);
stmt->def = (Node *) nconc(cxt.ckconstraints, cxt.fkconstraints);
! *extras_before = nconc(*extras_before, cxt.blist);
! *extras_after = nconc(cxt.alist, *extras_after);
break;

default:

---------------------------(end of broadcast)---------------------------
TIP 5: Have you checked our extensive FAQ?

http://www.postgresql.org/users-lounge/docs/faq.html

-- 
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 853-3000
  +  If your life is a hard drive,     |  830 Blythe Avenue
  +  Christ can be your backup.        |  Drexel Hill, Pennsylvania 19026