Nope.

The Attorney General of Texas, at the time Ted Cruz, sued to overturn this rule that many companies had. The way the law is now is that if you have a CC permit and leave the gun in your car then it is OK to bring it on to company property even if the company has strict rules forbidding such a thing.

A lot of folks got a big laugh out of this since Cruz, who is now a Senator, is always ranting about how big government is running over the rights of business owners when he did the very same thing.

I do know of one energy company that made it clear that if you are seen with a gun in your hand on their property their security people will shoot first and ask questions later, so if you want to open carry it is up to you if you think you can get away with it.