What does Coverity/clang static analysis actually do?

[BCS]

Hello Walter,

> Frankly, this is not an impressive list. These issues are discoverable
> using standard data flow analysis, and in fact are part of Digital
> Mars' optimizer. Here is the current state of it for dmd:
> 
> 1. Optimizer discovers it, but ignores the information. Due to the
> recent thread on it, I added a report for it for D (still ignored for
> C). The downside is I can no longer use *cast(char*)0=0 to drop me
> into the debugger, but I can live with that as assert(0) will do the
> same thing.

nice

> 4. Dead assignments are automatically detected and removed. I'm not
> convinced this should be reported, as it can legitimately happen when
> generating source code. Generating false positives annoy the heck out
> of users.

vote++ on silent

> 6. Arrays are solidly covered by a runtime check. There is code in the
> optimizer to detect many cases of overflows at compile time, but the
> code is currently disabled because the runtime check covers 100% of
> the cases.


I'd advocate for any compile time checks that never generate false positives 
running even if the runtime checks would get it also. I'd rather known sooner 
than later.