[cfe-commits] patch: add __attribute__((halting))

[Douglas Gregor]

On Jul 5, 2010, at 11:55 PM, Nick Lewycky wrote:

> This patch adds support for an attribute used to indicate that the function in question will not loop indefinitely. This is a counter-part to the LLVM patch http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20100705/103672.html which must be applied first.
> 
> The idea is that we can't currently delete the dead code:
>   void foo(set<int> *s) { s->find(10); }
> because the compiler is afraid that set<>::find may have the side-effect of infinite looping. With a halting attribute manually applied in key places, such as the declaration of find(), we can unstick dead code elimination and ultimately reduce code size.
> 
> Please review!


The patch looks good, although you're missing PCH (de-)serialization code for the new attribute.

	- Doug
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