Tony Hoare (Mr. Quicksort, CSP, etc...) has softened his stance since "The Emperor's Old Clothes", but his concern was that ADA is too complicated to be understandable and safe. I hated Pascal because the array length was part of its type... but maybe that kind of thinking is apparently what it takes to avoid bugs like Heartbleed.
Can I suggest you take a quick look at ATS? The language itself is kind of horrid (and I am a ML fan) and the learning curve is way steep, but the thin, dependently typed layer over C aspect is actually quite nice.
Note: I'm not suggesting it for current production use, but rather as something that could be expanded further in the future.
