lock3.prop

C程序漏洞检查

void
uno_check(void)					 // handle multiple locks
{
	if (select("lock", FCALL, NONE))	 // find all calls to lock
	if (select("", DEF, NONE))		 // select symbols defined in call
	{	if (match(1, DEF, NONE)) 	 // check if any were previously marked
			error("lock after lock"); // if so, complain
		else
			mark(1);		 // else mark the symbol
	}

	if (select("unlock", FCALL, NONE))	 // find all calls to unlock
	if (select("", USE, NONE))		 // select symbols used in call
	{	if (match(1, DEF, NONE))	 //check if previously marked
			unmark();		 // if so, remove the mark
		else				 // else complain
			error("unlock without preceding lock");
	}

	if (path_ends())			 // at any return or exit statement
	if (marked(1, ANY, NONE))		 // check if any locks in effect
		error("lock without unlock");	 // if so, complain
}