Function ExecInitTableFunctionResult

src/backend/executor/execSRF.c:55–90

* Prepare function call in FROM (ROWS FROM) for execution. * * This is used by nodeFunctionscan.c. */

 * This is used by nodeFunctionscan.c.
 */
SetExprState *
ExecInitTableFunctionResult(Expr *expr,
							ExprContext *econtext, PlanState *parent)
{
	SetExprState *state = makeNode(SetExprState);

	state->funcReturnsSet = false;
	state->expr = expr;
	state->func.fn_oid = InvalidOid;

	/*
	 * Normally the passed expression tree will be a FuncExpr, since the
	 * grammar only allows a function call at the top level of a table
	 * function reference.  However, if the function doesn't return set then
	 * the planner might have replaced the function call via constant-folding
	 * or inlining.  So if we see any other kind of expression node, execute
	 * it via the general ExecEvalExpr() code.  That code path will not
	 * support set-returning functions buried in the expression, though.
	 */
	if (IsA(expr, FuncExpr))
	{
		FuncExpr   *func = (FuncExpr *) expr;

		state->funcReturnsSet = func->funcretset;
		state->args = ExecInitExprList(func->args, parent);

		init_sexpr(func->funcid, func->inputcollid, expr, state, parent,
				   econtext->ecxt_per_query_memory, func->funcretset, false);
	}
	else
	{
		state->elidedFuncState = ExecInitExpr(expr, parent);
	}

	return state;
}

/*
 *		ExecMakeTableFunctionResult