Replace remaining castNode(…, lfirst(…)) and friends calls with l*_node() - Mailing list pgsql-hackers

Hi hackers,

We've had node-casting versions of the list extraction macros since
2017, but several cases of the written-out version have been added since
then (even by Tom, who added the l*_node() macros).

Here's a patch to convert the remaining ones.  The macros were
back-patched to all supported branches, so this won't create any
new back-patching hazards.

- ilmari

From be3556361bcba2f332f51b75aa13946359335ae2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Dagfinn=20Ilmari=20Manns=C3=A5ker?= <ilmari@ilmari.org>
Date: Wed, 7 Jul 2021 11:44:23 +0100
Subject: [PATCH] Use l*_node() family of functions where appropriate
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Instead of castNode(…, lfoo(…))
---
 src/backend/commands/publicationcmds.c         |  2 +-
 src/backend/commands/tablecmds.c               |  8 ++++----
 src/backend/executor/execPartition.c           |  2 +-
 src/backend/executor/nodeValuesscan.c          |  2 +-
 src/backend/optimizer/util/paramassign.c       |  2 +-
 src/backend/parser/parse_clause.c              |  2 +-
 src/backend/parser/parse_utilcmd.c             |  8 ++++----
 src/backend/partitioning/partbounds.c          | 18 +++++++++---------
 src/backend/rewrite/rewriteSearchCycle.c       |  8 ++++----
 src/backend/tcop/postgres.c                    |  2 +-
 src/backend/utils/adt/ruleutils.c              |  6 +++---
 src/pl/plpgsql/src/pl_exec.c                   |  2 +-
 src/test/modules/test_predtest/test_predtest.c |  4 ++--
 13 files changed, 33 insertions(+), 33 deletions(-)

diff --git a/src/backend/commands/publicationcmds.c b/src/backend/commands/publicationcmds.c
index 95c253c8e0..08f94fa324 100644
--- a/src/backend/commands/publicationcmds.c
+++ b/src/backend/commands/publicationcmds.c
@@ -515,7 +515,7 @@ OpenTableList(List *tables)
      */
     foreach(lc, tables)
     {
-        RangeVar   *rv = castNode(RangeVar, lfirst(lc));
+        RangeVar   *rv = lfirst_node(RangeVar, lc);
         bool        recurse = rv->inh;
         Relation    rel;
         Oid            myrelid;
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 97a9725df7..ba71ceed64 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -4770,7 +4770,7 @@ ATRewriteCatalogs(List **wqueue, LOCKMODE lockmode,
 
             foreach(lcmd, subcmds)
                 ATExecCmd(wqueue, tab,
-                          castNode(AlterTableCmd, lfirst(lcmd)),
+                          lfirst_node(AlterTableCmd, lcmd),
                           lockmode, pass, context);
 
             /*
@@ -12753,7 +12753,7 @@ ATPostAlterTypeParse(Oid oldId, Oid oldRelId, Oid refRelId, char *cmd,
 
             foreach(lcmd, stmt->cmds)
             {
-                AlterTableCmd *cmd = castNode(AlterTableCmd, lfirst(lcmd));
+                AlterTableCmd *cmd = lfirst_node(AlterTableCmd, lcmd);
 
                 if (cmd->subtype == AT_AddIndex)
                 {
@@ -16571,7 +16571,7 @@ transformPartitionSpec(Relation rel, PartitionSpec *partspec, char *strategy)
     /* take care of any partition expressions */
     foreach(l, partspec->partParams)
     {
-        PartitionElem *pelem = castNode(PartitionElem, lfirst(l));
+        PartitionElem *pelem = lfirst_node(PartitionElem, l);
 
         if (pelem->expr)
         {
@@ -16608,7 +16608,7 @@ ComputePartitionAttrs(ParseState *pstate, Relation rel, List *partParams, AttrNu
     attn = 0;
     foreach(lc, partParams)
     {
-        PartitionElem *pelem = castNode(PartitionElem, lfirst(lc));
+        PartitionElem *pelem = lfirst_node(PartitionElem, lc);
         Oid            atttype;
         Oid            attcollation;
 
diff --git a/src/backend/executor/execPartition.c b/src/backend/executor/execPartition.c
index 606c920b06..5c723bc54e 100644
--- a/src/backend/executor/execPartition.c
+++ b/src/backend/executor/execPartition.c
@@ -585,7 +585,7 @@ ExecInitPartitionInfo(ModifyTableState *mtstate, EState *estate,
 
         foreach(ll, wcoList)
         {
-            WithCheckOption *wco = castNode(WithCheckOption, lfirst(ll));
+            WithCheckOption *wco = lfirst_node(WithCheckOption, ll);
             ExprState  *wcoExpr = ExecInitQual(castNode(List, wco->qual),
                                                &mtstate->ps);
 
diff --git a/src/backend/executor/nodeValuesscan.c b/src/backend/executor/nodeValuesscan.c
index 5de1429fda..00bd1271e4 100644
--- a/src/backend/executor/nodeValuesscan.c
+++ b/src/backend/executor/nodeValuesscan.c
@@ -285,7 +285,7 @@ ExecInitValuesScan(ValuesScan *node, EState *estate, int eflags)
     i = 0;
     foreach(vtl, node->values_lists)
     {
-        List       *exprs = castNode(List, lfirst(vtl));
+        List       *exprs = lfirst_node(List, vtl);
 
         scanstate->exprlists[i] = exprs;
 
diff --git a/src/backend/optimizer/util/paramassign.c b/src/backend/optimizer/util/paramassign.c
index ebb424112b..61b856a959 100644
--- a/src/backend/optimizer/util/paramassign.c
+++ b/src/backend/optimizer/util/paramassign.c
@@ -431,7 +431,7 @@ process_subquery_nestloop_params(PlannerInfo *root, List *subplan_params)
 
     foreach(lc, subplan_params)
     {
-        PlannerParamItem *pitem = castNode(PlannerParamItem, lfirst(lc));
+        PlannerParamItem *pitem = lfirst_node(PlannerParamItem, lc);
 
         if (IsA(pitem->item, Var))
         {
diff --git a/src/backend/parser/parse_clause.c b/src/backend/parser/parse_clause.c
index 71c360bea5..b3f151d33b 100644
--- a/src/backend/parser/parse_clause.c
+++ b/src/backend/parser/parse_clause.c
@@ -2807,7 +2807,7 @@ transformWindowDefinitions(ParseState *pstate,
                         (errcode(ERRCODE_WINDOWING_ERROR),
                          errmsg("RANGE with offset PRECEDING/FOLLOWING requires exactly one ORDER BY column"),
                          parser_errposition(pstate, windef->location)));
-            sortcl = castNode(SortGroupClause, linitial(wc->orderClause));
+            sortcl = linitial_node(SortGroupClause, wc->orderClause);
             sortkey = get_sortgroupclause_expr(sortcl, *targetlist);
             /* Find the sort operator in pg_amop */
             if (!get_ordering_op_properties(sortcl->sortop,
diff --git a/src/backend/parser/parse_utilcmd.c b/src/backend/parser/parse_utilcmd.c
index 81d3e7990c..16abacd76c 100644
--- a/src/backend/parser/parse_utilcmd.c
+++ b/src/backend/parser/parse_utilcmd.c
@@ -2425,7 +2425,7 @@ transformIndexConstraint(Constraint *constraint, CreateStmtContext *cxt)
             /* Make sure referenced column exists. */
             foreach(columns, cxt->columns)
             {
-                column = castNode(ColumnDef, lfirst(columns));
+                column = lfirst_node(ColumnDef, columns);
                 if (strcmp(column->colname, key) == 0)
                 {
                     found = true;
@@ -2463,7 +2463,7 @@ transformIndexConstraint(Constraint *constraint, CreateStmtContext *cxt)
 
                 foreach(inher, cxt->inhRelations)
                 {
-                    RangeVar   *inh = castNode(RangeVar, lfirst(inher));
+                    RangeVar   *inh = lfirst_node(RangeVar, inher);
                     Relation    rel;
                     int            count;
 
@@ -4089,7 +4089,7 @@ transformPartitionBound(ParseState *pstate, Relation parent,
             duplicate = false;
             foreach(cell2, result_spec->listdatums)
             {
-                Const       *value2 = castNode(Const, lfirst(cell2));
+                Const       *value2 = lfirst_node(Const, cell2);
 
                 if (equal(value, value2))
                 {
@@ -4268,7 +4268,7 @@ validateInfiniteBounds(ParseState *pstate, List *blist)
 
     foreach(lc, blist)
     {
-        PartitionRangeDatum *prd = castNode(PartitionRangeDatum, lfirst(lc));
+        PartitionRangeDatum *prd = lfirst_node(PartitionRangeDatum, lc);
 
         if (kind == prd->kind)
             continue;
diff --git a/src/backend/partitioning/partbounds.c b/src/backend/partitioning/partbounds.c
index 38baaefcda..be35068384 100644
--- a/src/backend/partitioning/partbounds.c
+++ b/src/backend/partitioning/partbounds.c
@@ -453,7 +453,7 @@ get_non_null_list_datum_count(PartitionBoundSpec **boundspecs, int nparts)
 
         foreach(lc, boundspecs[i]->listdatums)
         {
-            Const       *val = castNode(Const, lfirst(lc));
+            Const       *val = lfirst_node(Const, lc);
 
             if (!val->constisnull)
                 count++;
@@ -514,7 +514,7 @@ create_list_bounds(PartitionBoundSpec **boundspecs, int nparts,
 
         foreach(c, spec->listdatums)
         {
-            Const       *val = castNode(Const, lfirst(c));
+            Const       *val = lfirst_node(Const, c);
 
             if (!val->constisnull)
             {
@@ -3015,7 +3015,7 @@ check_new_partition_bound(char *relname, Relation parent,
 
                     foreach(cell, spec->listdatums)
                     {
-                        Const       *val = castNode(Const, lfirst(cell));
+                        Const       *val = lfirst_node(Const, cell);
 
                         overlap_location = val->location;
                         if (!val->constisnull)
@@ -3400,7 +3400,7 @@ make_one_partition_rbound(PartitionKey key, int index, List *datums, bool lower)
     i = 0;
     foreach(lc, datums)
     {
-        PartitionRangeDatum *datum = castNode(PartitionRangeDatum, lfirst(lc));
+        PartitionRangeDatum *datum = lfirst_node(PartitionRangeDatum, lc);
 
         /* What's contained in this range datum? */
         bound->kind[i] = datum->kind;
@@ -4104,7 +4104,7 @@ get_qual_for_list(Relation parent, PartitionBoundSpec *spec)
          */
         foreach(cell, spec->listdatums)
         {
-            Const       *val = castNode(Const, lfirst(cell));
+            Const       *val = lfirst_node(Const, cell);
 
             if (val->constisnull)
                 list_has_null = true;
@@ -4359,8 +4359,8 @@ get_qual_for_range(Relation parent, PartitionBoundSpec *spec,
         Datum        test_result;
         bool        isNull;
 
-        ldatum = castNode(PartitionRangeDatum, lfirst(cell1));
-        udatum = castNode(PartitionRangeDatum, lfirst(cell2));
+        ldatum = lfirst_node(PartitionRangeDatum, cell1);
+        udatum = lfirst_node(PartitionRangeDatum, cell2);
 
         /*
          * Since get_range_key_properties() modifies partexprs_item, and we
@@ -4441,11 +4441,11 @@ get_qual_for_range(Relation parent, PartitionBoundSpec *spec,
             PartitionRangeDatum *ldatum_next = NULL,
                        *udatum_next = NULL;
 
-            ldatum = castNode(PartitionRangeDatum, lfirst(cell1));
+            ldatum = lfirst_node(PartitionRangeDatum, cell1);
             if (lnext(spec->lowerdatums, cell1))
                 ldatum_next = castNode(PartitionRangeDatum,
                                        lfirst(lnext(spec->lowerdatums, cell1)));
-            udatum = castNode(PartitionRangeDatum, lfirst(cell2));
+            udatum = lfirst_node(PartitionRangeDatum, cell2);
             if (lnext(spec->upperdatums, cell2))
                 udatum_next = castNode(PartitionRangeDatum,
                                        lfirst(lnext(spec->upperdatums, cell2)));
diff --git a/src/backend/rewrite/rewriteSearchCycle.c b/src/backend/rewrite/rewriteSearchCycle.c
index 599fe8e735..c50ebdba24 100644
--- a/src/backend/rewrite/rewriteSearchCycle.c
+++ b/src/backend/rewrite/rewriteSearchCycle.c
@@ -307,8 +307,8 @@ rewriteSearchAndCycle(CommonTableExpr *cte)
                       list_nth_oid(cte->ctecolcollations, i),
                       0);
         tle = makeTargetEntry((Expr *) var, i + 1, strVal(list_nth(cte->ctecolnames, i)), false);
-        tle->resorigtbl = castNode(TargetEntry, list_nth(rte1->subquery->targetList, i))->resorigtbl;
-        tle->resorigcol = castNode(TargetEntry, list_nth(rte1->subquery->targetList, i))->resorigcol;
+        tle->resorigtbl = list_nth_node(TargetEntry, rte1->subquery->targetList, i)->resorigtbl;
+        tle->resorigcol = list_nth_node(TargetEntry, rte1->subquery->targetList, i)->resorigcol;
         newq1->targetList = lappend(newq1->targetList, tle);
     }
 
@@ -482,8 +482,8 @@ rewriteSearchAndCycle(CommonTableExpr *cte)
                       list_nth_oid(cte->ctecolcollations, i),
                       0);
         tle = makeTargetEntry((Expr *) var, i + 1, strVal(list_nth(cte->ctecolnames, i)), false);
-        tle->resorigtbl = castNode(TargetEntry, list_nth(rte2->subquery->targetList, i))->resorigtbl;
-        tle->resorigcol = castNode(TargetEntry, list_nth(rte2->subquery->targetList, i))->resorigcol;
+        tle->resorigtbl = list_nth_node(TargetEntry, rte2->subquery->targetList, i)->resorigtbl;
+        tle->resorigcol = list_nth_node(TargetEntry, rte2->subquery->targetList, i)->resorigcol;
         newq2->targetList = lappend(newq2->targetList, tle);
     }
 
diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c
index 8cea10c901..530caa520b 100644
--- a/src/backend/tcop/postgres.c
+++ b/src/backend/tcop/postgres.c
@@ -785,7 +785,7 @@ pg_rewrite_query(Query *query)
          */
         foreach(lc, querytree_list)
         {
-            Query       *query = castNode(Query, lfirst(lc));
+            Query       *query = lfirst_node(Query, lc);
 
             if (query->commandType != CMD_UTILITY)
             {
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 3719755a0d..5e7108f903 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -7793,7 +7793,7 @@ find_param_referent(Param *param, deparse_context *context,
              */
             foreach(lc2, ((Plan *) ancestor)->initPlan)
             {
-                SubPlan    *subplan = castNode(SubPlan, lfirst(lc2));
+                SubPlan    *subplan = lfirst_node(SubPlan, lc2);
 
                 if (child_plan != (Plan *) list_nth(dpns->subplans,
                                                     subplan->plan_id - 1))
@@ -9407,7 +9407,7 @@ get_rule_expr(Node *node, deparse_context *context,
                         sep = "";
                         foreach(cell, spec->listdatums)
                         {
-                            Const       *val = castNode(Const, lfirst(cell));
+                            Const       *val = lfirst_node(Const, cell);
 
                             appendStringInfoString(buf, sep);
                             get_const_expr(val, context, -1);
@@ -11990,7 +11990,7 @@ get_range_partbound_string(List *bound_datums)
     foreach(cell, bound_datums)
     {
         PartitionRangeDatum *datum =
-        castNode(PartitionRangeDatum, lfirst(cell));
+        lfirst_node(PartitionRangeDatum, cell);
 
         appendStringInfoString(buf, sep);
         if (datum->kind == PARTITION_RANGE_DATUM_MINVALUE)
diff --git a/src/pl/plpgsql/src/pl_exec.c b/src/pl/plpgsql/src/pl_exec.c
index 96bb77e0b1..b5c208d83d 100644
--- a/src/pl/plpgsql/src/pl_exec.c
+++ b/src/pl/plpgsql/src/pl_exec.c
@@ -7996,7 +7996,7 @@ exec_save_simple_expr(PLpgSQL_expr *expr, CachedPlan *cplan)
     {
         /* Extract the single tlist expression */
         Assert(list_length(plan->targetlist) == 1);
-        tle_expr = castNode(TargetEntry, linitial(plan->targetlist))->expr;
+        tle_expr = linitial_node(TargetEntry, plan->targetlist)->expr;
 
         if (IsA(plan, Result))
         {
diff --git a/src/test/modules/test_predtest/test_predtest.c b/src/test/modules/test_predtest/test_predtest.c
index 9c0aadd61c..0301d48443 100644
--- a/src/test/modules/test_predtest/test_predtest.c
+++ b/src/test/modules/test_predtest/test_predtest.c
@@ -131,8 +131,8 @@ test_predtest(PG_FUNCTION_ARGS)
         elog(ERROR, "failed to decipher query plan");
     plan = stmt->planTree;
     Assert(list_length(plan->targetlist) >= 2);
-    clause1 = castNode(TargetEntry, linitial(plan->targetlist))->expr;
-    clause2 = castNode(TargetEntry, lsecond(plan->targetlist))->expr;
+    clause1 = linitial_node(TargetEntry, plan->targetlist)->expr;
+    clause2 = lsecond_node(TargetEntry, plan->targetlist)->expr;
 
     /*
      * Because the clauses are in the SELECT list, preprocess_expression did
-- 
2.30.2