Function ExecEvalSubPlan

src/backend/executor/execExprInterp.c:4155–4164

* Hand off evaluation of a subplan to nodeSubplan.c */

 * Hand off evaluation of a subplan to nodeSubplan.c
 */
void
ExecEvalSubPlan(ExprState *state, ExprEvalStep *op, ExprContext *econtext)
{
	SubPlanState *sstate = op->d.subplan.sstate;

	/* could potentially be nested, so make sure there's enough stack */
	check_stack_depth();

	*op->resvalue = ExecSubPlan(sstate, econtext, op->resnull);
}

/*
 * Evaluate a wholerow Var expression.