ptrs.prop

来自「C程序漏洞检查」· PROP 代码 · 共 40 行

void
uno_check(void)
{
	if (select("", DECL, ARRAY_DECL))
	if (refine(DEREF, DEF))
	{	mark(1);	// mark uninitialized pointer vars
//		list("mark 1");	// debugging
	}

	if (select("", USE|DEF, NONE))
	if (refine(DEREF, ALIAS))
	if (match(1, ANY,  NONE))
	{	if (known_zero())
			error("dereferencing uninitialized ptr");
		else
		{	if (known_nonzero())
				no_error();
			else
				error("dereferencing possibly uninitialized ptr");
	}	}

	if (select("", DEF, DEREF))
	if (match(1, ANY, NONE))
	{	mark(2);	// initialized ptrs are marked 2
//		list("mark 2");
	}

	if (select("free", FCALL, NONE))
	if (select("", USE, NONE))
	if (match(1, ANY, NONE))
		error("freeing an uninitialized ptr");

	if (select("free", FCALL, NONE))
	if (select("", USE, NONE))
	if (match(2, ANY, NONE))
	{	mark(1);	// this ptr is now uninitialized again
//		list("remark 1");
	}
}