Don't warn for declaration-after-statement since we only support GNU99 (#3132)

This change was actually already intended in #3124. However, the
postgres Makefile manually enables this warning too. This way we undo
that.

To confirm that it works two functions were changed to make use of not
having the warning anymore.

configure

@@ -3946,6 +3946,45 @@ if test x"$citusac_cv_prog_cc_cflags__Wno_gnu_variable_sized_type_not_at_end" =
   CITUS_CFLAGS="$CITUS_CFLAGS -Wno-gnu-variable-sized-type-not-at-end"
 fi
 
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $CC supports -Wno-declaration-after-statement" >&5
+$as_echo_n "checking whether $CC supports -Wno-declaration-after-statement... " >&6; }
+if ${citusac_cv_prog_cc_cflags__Wno_declaration_after_statement+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  citusac_save_CFLAGS=$CFLAGS
+flag=-Wno-declaration-after-statement
+case $flag in -Wno*)
+	 flag=-W$(echo $flag | cut -c 6-)
+esac
+CFLAGS="$citusac_save_CFLAGS $flag"
+ac_save_c_werror_flag=$ac_c_werror_flag
+ac_c_werror_flag=yes
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main ()
+{
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  citusac_cv_prog_cc_cflags__Wno_declaration_after_statement=yes
+else
+  citusac_cv_prog_cc_cflags__Wno_declaration_after_statement=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+ac_c_werror_flag=$ac_save_c_werror_flag
+CFLAGS="$citusac_save_CFLAGS"
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $citusac_cv_prog_cc_cflags__Wno_declaration_after_statement" >&5
+$as_echo "$citusac_cv_prog_cc_cflags__Wno_declaration_after_statement" >&6; }
+if test x"$citusac_cv_prog_cc_cflags__Wno_declaration_after_statement" = x"yes"; then
+  CITUS_CFLAGS="$CITUS_CFLAGS -Wno-declaration-after-statement"
+fi
+
 # And add a few extra warnings
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $CC supports -Wendif-labels" >&5
 $as_echo_n "checking whether $CC supports -Wendif-labels... " >&6; }

configure.in

@@ -163,6 +163,7 @@ CITUSAC_PROG_CC_CFLAGS_OPT([-Wno-sign-compare])
 CITUSAC_PROG_CC_CFLAGS_OPT([-Wno-missing-field-initializers])
 CITUSAC_PROG_CC_CFLAGS_OPT([-Wno-clobbered])
 CITUSAC_PROG_CC_CFLAGS_OPT([-Wno-gnu-variable-sized-type-not-at-end])
+CITUSAC_PROG_CC_CFLAGS_OPT([-Wno-declaration-after-statement])
 # And add a few extra warnings
 CITUSAC_PROG_CC_CFLAGS_OPT([-Wendif-labels])
 CITUSAC_PROG_CC_CFLAGS_OPT([-Wmissing-format-attribute])

src/backend/distributed/planner/multi_master_planner.c

@@ -17,6 +17,7 @@
 #include "commands/extension.h"
 #include "distributed/citus_ruleutils.h"
 #include "distributed/function_utils.h"
+#include "distributed/listutils.h"
 #include "distributed/multi_logical_optimizer.h"
 #include "distributed/multi_master_planner.h"
 #include "distributed/multi_physical_planner.h"
@@ -141,13 +142,13 @@ MasterTargetList(List *workerTargetList)
 static PlannedStmt *
 BuildSelectStatement(Query *masterQuery, List *masterTargetList, CustomScan *remoteScan)
 {
-	PlannedStmt *selectStatement = NULL;
+	/* top level select query should have only one range table entry */
+	Assert(list_length(masterQuery->rtable) == 1);
 	Agg *aggregationPlan = NULL;
 	Plan *topLevelPlan = NULL;
 	List *sortClauseList = copyObject(masterQuery->sortClause);
-	ListCell *targetEntryCell = NULL;
+	List *columnNameList = NIL;
-	List *columnNameList = NULL;
+	TargetEntry *targetEntry = NULL;
-	RangeTblEntry *customScanRangeTableEntry = NULL;
 
 	PlannerGlobal *glob = makeNode(PlannerGlobal);
 	PlannerInfo *root = makeNode(PlannerInfo);
@@ -159,13 +160,11 @@ BuildSelectStatement(Query *masterQuery, List *masterTargetList, CustomScan *rem
 
 
 	/* (1) make PlannedStmt and set basic information */
-	selectStatement = makeNode(PlannedStmt);
+	PlannedStmt *selectStatement = makeNode(PlannedStmt);
 	selectStatement->canSetTag = true;
 	selectStatement->relationOids = NIL;
 	selectStatement->commandType = CMD_SELECT;
 
-	/* top level select query should have only one range table entry */
-	Assert(list_length(masterQuery->rtable) == 1);
 
 	remoteScan->custom_scan_tlist = masterTargetList;
 
@@ -276,13 +275,12 @@ BuildSelectStatement(Query *masterQuery, List *masterTargetList, CustomScan *rem
 	/*
 	 * (7) Replace rangetable with one with nice names to show in EXPLAIN plans
 	 */
-	foreach(targetEntryCell, masterTargetList)
+	foreach_ptr(targetEntry, masterTargetList)
 	{
-		TargetEntry *targetEntry = lfirst(targetEntryCell);
 		columnNameList = lappend(columnNameList, makeString(targetEntry->resname));
 	}
 
-	customScanRangeTableEntry = linitial(selectStatement->rtable);
+	RangeTblEntry *customScanRangeTableEntry = linitial(selectStatement->rtable);
 	customScanRangeTableEntry->eref = makeAlias("remote_scan", columnNameList);
 
 	return selectStatement;
@@ -371,18 +369,12 @@ FinalizeStatement(PlannerInfo *root, PlannedStmt *result, Plan *top_plan)
 static Agg *
 BuildAggregatePlan(PlannerInfo *root, Query *masterQuery, Plan *subPlan)
 {
-	Agg *aggregatePlan = NULL;
-	AggStrategy aggregateStrategy = AGG_PLAIN;
-	AggClauseCosts aggregateCosts;
-	List *aggregateTargetList = NIL;
-	List *groupColumnList = NIL;
-	Node *havingQual = NULL;
-	uint32 groupColumnCount = 0;
-
 	/* assert that we need to build an aggregate plan */
 	Assert(masterQuery->hasAggs || masterQuery->groupClause);
-
+	AggClauseCosts aggregateCosts;
-	aggregateTargetList = masterQuery->targetList;
+	AggStrategy aggregateStrategy = AGG_PLAIN;
+	List *groupColumnList = masterQuery->groupClause;
+	List *aggregateTargetList = masterQuery->targetList;
 
 	/*
 	 * Replaces SubLink nodes with SubPlan nodes in the having section of the
@@ -392,7 +384,7 @@ BuildAggregatePlan(PlannerInfo *root, Query *masterQuery, Plan *subPlan)
 	 * these when that is true. However, for some reason hasSubLinks is false
 	 * even when there are SubLinks.
 	 */
-	havingQual = SS_process_sublinks(root, masterQuery->havingQual, true);
+	Node *havingQual = SS_process_sublinks(root, masterQuery->havingQual, true);
 
 	/*
 	 * Right now this is not really needed, since we don't support correlated
@@ -409,11 +401,9 @@ BuildAggregatePlan(PlannerInfo *root, Query *masterQuery, Plan *subPlan)
 
 	get_agg_clause_costs(root, (Node *) havingQual, AGGSPLIT_SIMPLE, &aggregateCosts);
 
-	groupColumnList = masterQuery->groupClause;
-	groupColumnCount = list_length(groupColumnList);
 
 	/* if we have grouping, then initialize appropriate information */
-	if (groupColumnCount > 0)
+	if (list_length(groupColumnList) > 0)
 	{
 		bool groupingIsHashable = grouping_is_hashable(groupColumnList);
 		bool groupingIsSortable = grouping_is_sortable(groupColumnList);
@@ -460,8 +450,8 @@ BuildAggregatePlan(PlannerInfo *root, Query *masterQuery, Plan *subPlan)
 	}
 
 	/* finally create the plan */
-	aggregatePlan = makeAggNode(groupColumnList, (List *) havingQual,
+	Agg *aggregatePlan = makeAggNode(groupColumnList, (List *) havingQual,
-								aggregateStrategy, aggregateTargetList, subPlan);
+									 aggregateStrategy, aggregateTargetList, subPlan);
 
 	/* just for reproducible costs between different PostgreSQL versions */
 	aggregatePlan->plan.startup_cost = 0;