I recently had a colleague show me a digest on the potential issues of LLVM. I am not sure how valid this information is, and its an interesting read- if your into this sort-of-stuff 
Here is the link to the original thread What is the bad side about LLVM?
The article text is shown below with reference material.
The great majority of active development of LLVM, is financed by Apple, Google, and Qualcomm.
For the most part, it’s a Good Thing to have big companies put their weight behind making LLVM better.
On the other hand, LLVM is quietly becoming a strategy for companies to assert their own proprietary intellectual property, as industry standard.
Consider, for example, Go. Go is an entirely Google-owned language, and LLVM supports it as a first-class front end. However, use of LLVM’s Go implementation, implies acceptance of Google’s terms to use Go.
I imagine that a brilliant but evil lawyer could use those terms, to find a way to make trouble, for almost any user of Go.
Now certainly, Google does not seem to be in a hurry to sue anyone, over the use of Go.
But the personalities of tech companies can shift over time.
Remember that Sun used to be a very lovable, hacker-friendly tech company. They created Java and played nice with it.
Until Oracle acquired Sun, and decided to sue every big company that ever considered using Java in their projects.
I’m picking on Google, but similar arguments could be made for Qualcomm, Apple, Samsung, Sony, and most of the other big companies who are contributing platform and language specific extensions to LLVM.
The LLVM Foundation was fully cognizant of these issues. About four years ago, they made some kind of attempt to reconcile all these different intellectual properties, under a common license agreement.
That effort has resulted in the foundation more or less throwing up its hands, and saying “you guys figure it out.”
In other words: companies that contribute to LLVM, retain the rights to their intellectual property, under whatever terms the companies choose.
Now gcc sidestepped this whole issue, because it came with its own highly opinionated license.
This concern is not a deal breaker for LLVM, either as a technology or as a melting pot. Hackers tend to play nice with one another, even across company boundaries.
My personal concern is: all it takes is one Darl McBride, to shit in the pool that everyone’s enjoying all nicely together… to twirl his dark moustache, cackle with glee, and declare that the entirety of LLVM is MINE, ALL MINE!!!
History has a way of repeating itself. Hope I’m wrong.