不定式的完成式可以作主语的，请参见陈老师的以下解答：

http://ask.yygrammar.com/q-1052.html 

动名词的完成式可以作主语的，如下面两句摘自张道真的《英语语法大全》第1027节“动名词作主语”一节：

Having seen the world sixty years is not enough to make one wise. 

Having studied biology is an important qualification for the study of agriculture.