Modernize some code a bit

Modernize code in ExecRelCheck() and ExecConstraints() a bit,
preparing the way for some new code.

Co-authored-by: jian he <jian.universality@gmail.com>
Reviewed-by: Xuneng Zhou <xunengzhou@gmail.com>
Reviewed-by: Navneet Kumar <thanit3111@gmail.com>
Reviewed-by: Álvaro Herrera <alvherre@alvh.no-ip.org>
Discussion: https://postgr.es/m/CACJufxHArQysbDkWFmvK+D1TPHQWWTxWN15cMuUaTYX3xhQXgg@mail.gmail.com

diff --git a/src/backend/executor/execMain.c b/src/backend/executor/execMain.c
index 1cd4dbd2b90d6d79bb39ad9f77ddb39eba519778..a22712755713087a8a519e0a4786e4d3753b3d7c 100644 (file)
--- a/src/backend/executor/execMain.c
+++ b/src/backend/executor/execMain.c
@@ -1855,7 +1855,6 @@ ExecRelCheck(ResultRelInfo *resultRelInfo,
        ConstrCheck *check = rel->rd_att->constr->check;
        ExprContext *econtext;
        MemoryContext oldContext;
-       int                     i;
 
        /*
         * CheckConstraintFetch let this pass with only a warning, but now we
@@ -1874,9 +1873,8 @@ ExecRelCheck(ResultRelInfo *resultRelInfo,
        if (resultRelInfo->ri_CheckConstraintExprs == NULL)
        {
                oldContext = MemoryContextSwitchTo(estate->es_query_cxt);
-               resultRelInfo->ri_CheckConstraintExprs =
-                       (ExprState **) palloc0(ncheck * sizeof(ExprState *));
-               for (i = 0; i < ncheck; i++)
+               resultRelInfo->ri_CheckConstraintExprs = palloc0_array(ExprState *, ncheck);
+               for (int i = 0; i < ncheck; i++)
                {
                        Expr       *checkconstr;
 
@@ -1902,7 +1900,7 @@ ExecRelCheck(ResultRelInfo *resultRelInfo,
        econtext->ecxt_scantuple = slot;
 
        /* And evaluate the constraints */
-       for (i = 0; i < ncheck; i++)
+       for (int i = 0; i < ncheck; i++)
        {
                ExprState  *checkconstr = resultRelInfo->ri_CheckConstraintExprs[i];
 
@@ -2061,16 +2059,16 @@ ExecConstraints(ResultRelInfo *resultRelInfo,
 
        Assert(constr);                         /* we should not be called otherwise */
 
+       /*
+        * Verify not-null constraints.
+        */
        if (constr->has_not_null)
        {
-               int                     natts = tupdesc->natts;
-               int                     attrChk;
-
-               for (attrChk = 1; attrChk <= natts; attrChk++)
+               for (AttrNumber attnum = 1; attnum <= tupdesc->natts; attnum++)
                {
-                       Form_pg_attribute att = TupleDescAttr(tupdesc, attrChk - 1);
+                       Form_pg_attribute att = TupleDescAttr(tupdesc, attnum - 1);
 
-                       if (att->attnotnull && slot_attisnull(slot, attrChk))
+                       if (att->attnotnull && slot_attisnull(slot, attnum))
                        {
                                char       *val_desc;
                                Relation        orig_rel = rel;
@@ -2115,16 +2113,19 @@ ExecConstraints(ResultRelInfo *resultRelInfo,
                                                                                                                 64);
 
                                ereport(ERROR,
-                                               (errcode(ERRCODE_NOT_NULL_VIOLATION),
-                                                errmsg("null value in column \"%s\" of relation \"%s\" violates not-null constraint",
-                                                               NameStr(att->attname),
-                                                               RelationGetRelationName(orig_rel)),
-                                                val_desc ? errdetail("Failing row contains %s.", val_desc) : 0,
-                                                errtablecol(orig_rel, attrChk)));
+                                               errcode(ERRCODE_NOT_NULL_VIOLATION),
+                                               errmsg("null value in column \"%s\" of relation \"%s\" violates not-null constraint",
+                                                          NameStr(att->attname),
+                                                          RelationGetRelationName(orig_rel)),
+                                               val_desc ? errdetail("Failing row contains %s.", val_desc) : 0,
+                                               errtablecol(orig_rel, attnum));
                        }
                }
        }
 
+       /*
+        * Verify check constraints.
+        */
        if (rel->rd_rel->relchecks > 0)
        {
                const char *failed;