malloc.prop

来自「C程序漏洞检查！」· PROP 代码 · 共 32 行

void
uno_check(void)
{
	if (select("malloc", FCALL, NONE))		/* unmarked symbols of type function call */
	{	if (select("", DEF, NONE))		/* unmarked symbols DEFined in those stmnts */
		{	if (match(1, DEF, NONE))	/* are there matching symbols with mark 1? */
				error("malloc follows malloc");
			else
				mark(1);		/* mark 1 */
		} else
			error("result of malloc unused");
	} else

	if (select("free", FCALL, NONE))
	{	if (select("", USE, NONE))
		{	if (match(1, DEF, NONE))
				unmark();		/* remove mark */
			else
				error("free without malloc");
		} else
			error("no argument to free");
	}

	if (path_ends())
	{	if (marked(1, ANY, NONE))
		{	if (known_zero())
				no_error();
			else
				error("malloc without free");
	}	}
}