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Code cleanup inspired by recent resname bug report (doesn't fix the bug

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yet, though).  Avoid using nth() to fetch tlist entries; provide a
common routine get_tle_by_resno() to search a tlist for a particular
resno.  This replaces a couple uses of nth() and a dozen hand-coded
search loops.  Also, replace a few uses of nth(length-1, list) with
llast().
This commit is contained in:
Tom Lane
2003-08-11 20:46:47 +00:00
parent cae912d05b
commit 88381ade63
12 changed files with 161 additions and 316 deletions
Download Patch File Download Diff File Expand all files Collapse all files

46
src/backend/parser/parse_relation.c
View File

@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/parser/parse_relation.c,v 1.87 2003/08/04 02:40:02 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/parser/parse_relation.c,v 1.88 2003/08/11 20:46:46 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -1599,21 +1599,14 @@ get_rte_attribute_type(RangeTblEntry *rte, AttrNumber attnum,
case RTE_SUBQUERY:
{
/* Subselect RTE --- get type info from subselect's tlist */
List *tlistitem;
TargetEntry *te = get_tle_by_resno(rte->subquery->targetList,
attnum);
foreach(tlistitem, rte->subquery->targetList)
{
TargetEntry *te = (TargetEntry *) lfirst(tlistitem);
if (te->resdom->resjunk || te->resdom->resno != attnum)
continue;
*vartype = te->resdom->restype;
*vartypmod = te->resdom->restypmod;
return;
}
/* falling off end of list shouldn't happen... */
elog(ERROR, "subquery %s does not have attribute %d",
rte->eref->aliasname, attnum);
if (te == NULL || te->resdom->resjunk)
elog(ERROR, "subquery %s does not have attribute %d",
rte->eref->aliasname, attnum);
*vartype = te->resdom->restype;
*vartypmod = te->resdom->restypmod;
}
break;
case RTE_FUNCTION:
@@ -1777,6 +1770,29 @@ get_rte_attribute_is_dropped(RangeTblEntry *rte, AttrNumber attnum)
return result;
}
/*
* Given a targetlist and a resno, return the matching TargetEntry
*
* Returns NULL if resno is not present in list.
*
* Note: we need to search, rather than just indexing with nth(), because
* not all tlists are sorted by resno.
*/
TargetEntry *
get_tle_by_resno(List *tlist, AttrNumber resno)
{
List *i;
foreach(i, tlist)
{
TargetEntry *tle = (TargetEntry *) lfirst(i);
if (tle->resdom->resno == resno)
return tle;
}
return NULL;
}
/*
* given relation and att name, return id of variable
*

158
src/backend/parser/parse_target.c
View File

@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/parser/parse_target.c,v 1.110 2003/08/04 02:40:02 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/parser/parse_target.c,v 1.111 2003/08/11 20:46:46 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -100,49 +100,55 @@ transformTargetEntry(ParseState *pstate,
List *
transformTargetList(ParseState *pstate, List *targetlist)
{
List *p_target = NIL;
FastList p_target;
List *o_target;
while (targetlist != NIL)
FastListInit(&p_target);
foreach(o_target, targetlist)
{
ResTarget *res = (ResTarget *) lfirst(targetlist);
ResTarget *res = (ResTarget *) lfirst(o_target);
if (IsA(res->val, ColumnRef))
{
ColumnRef *cref = (ColumnRef *) res->val;
List *fields = cref->fields;
int numnames = length(fields);
if (numnames == 1 && strcmp(strVal(lfirst(fields)), "*") == 0)
if (strcmp(strVal(llast(fields)), "*") == 0)
{
/*
* Target item is a single '*', expand all tables (eg.
* SELECT * FROM emp)
*/
p_target = nconc(p_target,
ExpandAllTables(pstate));
}
else if (strcmp(strVal(nth(numnames - 1, fields)), "*") == 0)
{
/*
* Target item is relation.*, expand that table (eg.
* SELECT emp.*, dname FROM emp, dept)
*/
char *schemaname;
char *relname;
RangeTblEntry *rte;
int sublevels_up;
int numnames = length(fields);
switch (numnames)
if (numnames == 1)
{
case 2:
schemaname = NULL;
relname = strVal(lfirst(fields));
break;
case 3:
schemaname = strVal(lfirst(fields));
relname = strVal(lsecond(fields));
break;
case 4:
/*
* Target item is a single '*', expand all tables
* (e.g., SELECT * FROM emp)
*/
FastConc(&p_target,
ExpandAllTables(pstate));
}
else
{
/*
* Target item is relation.*, expand that table
* (e.g., SELECT emp.*, dname FROM emp, dept)
*/
char *schemaname;
char *relname;
RangeTblEntry *rte;
int sublevels_up;
switch (numnames)
{
case 2:
schemaname = NULL;
relname = strVal(lfirst(fields));
break;
case 3:
schemaname = strVal(lfirst(fields));
relname = strVal(lsecond(fields));
break;
case 4:
{
char *name1 = strVal(lfirst(fields));
@@ -152,57 +158,56 @@ transformTargetList(ParseState *pstate, List *targetlist)
*/
if (strcmp(name1, get_database_name(MyDatabaseId)) != 0)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cross-database references are not implemented")));
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cross-database references are not implemented")));
schemaname = strVal(lsecond(fields));
relname = strVal(lthird(fields));
break;
}
default:
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("improper qualified name (too many dotted names): %s",
NameListToString(fields))));
schemaname = NULL; /* keep compiler quiet */
relname = NULL;
break;
default:
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("improper qualified name (too many dotted names): %s",
NameListToString(fields))));
schemaname = NULL; /* keep compiler quiet */
relname = NULL;
break;
}
rte = refnameRangeTblEntry(pstate, schemaname, relname,
&sublevels_up);
if (rte == NULL)
rte = addImplicitRTE(pstate, makeRangeVar(schemaname,
relname));
FastConc(&p_target,
expandRelAttrs(pstate, rte));
}
rte = refnameRangeTblEntry(pstate, schemaname, relname,
&sublevels_up);
if (rte == NULL)
rte = addImplicitRTE(pstate, makeRangeVar(schemaname,
relname));
p_target = nconc(p_target,
expandRelAttrs(pstate, rte));
}
else
{
/* Plain ColumnRef node, treat it as an expression */
p_target = lappend(p_target,
transformTargetEntry(pstate,
res->val,
NULL,
res->name,
false));
FastAppend(&p_target,
transformTargetEntry(pstate,
res->val,
NULL,
res->name,
false));
}
}
else
{
/* Everything else but ColumnRef */
p_target = lappend(p_target,
transformTargetEntry(pstate,
res->val,
NULL,
res->name,
false));
FastAppend(&p_target,
transformTargetEntry(pstate,
res->val,
NULL,
res->name,
false));
}
targetlist = lnext(targetlist);
}
return p_target;
return FastListValue(&p_target);
}
@@ -264,23 +269,14 @@ markTargetListOrigin(ParseState *pstate, Resdom *res, Var *var)
case RTE_SUBQUERY:
{
/* Subselect-in-FROM: copy up from the subselect */
List *subtl;
TargetEntry *te = get_tle_by_resno(rte->subquery->targetList,
attnum);
foreach(subtl, rte->subquery->targetList)
{
TargetEntry *subte = (TargetEntry *) lfirst(subtl);
if (subte->resdom->resjunk ||
subte->resdom->resno != attnum)
continue;
res->resorigtbl = subte->resdom->resorigtbl;
res->resorigcol = subte->resdom->resorigcol;
break;
}
/* falling off end of list shouldn't happen... */
if (subtl == NIL)
if (te == NULL || te->resdom->resjunk)
elog(ERROR, "subquery %s does not have attribute %d",
rte->eref->aliasname, attnum);
res->resorigtbl = te->resdom->resorigtbl;
res->resorigcol = te->resdom->resorigcol;
}
break;
case RTE_JOIN: