[cfe-commits] r167397 - /cfe/trunk/lib/Frontend/CompilerInvocation.cpp

[Matt Beaumont-Gay]

On Mon, Nov 5, 2012 at 4:02 PM, Douglas Gregor <dgregor at apple.com> wrote:
>
> On Nov 5, 2012, at 3:58 PM, Matt Beaumont-Gay <matthewbg at google.com> wrote:
>
>> On Mon, Nov 5, 2012 at 11:45 AM, Douglas Gregor <dgregor at apple.com> wrote:
>>> Author: dgregor
>>> Date: Mon Nov  5 13:45:09 2012
>>> New Revision: 167397
>>>
>>> URL: http://llvm.org/viewvc/llvm-project?rev=167397&view=rev
>>> Log:
>>> Hash the various compiler version, target, preprocessor, and
>>> header-search options into the module hash. We're just using
>>> ADT/Hashing.hpp for this, which isn't as cryptographically strong as
>>> I'd like, but it'll do.
>>
>> Why do you want a cryptographic hash here?
>
>
> Simply because I don't trust that the existing hashes won't produce conflicts.

CityHash passes SMHasher with flying colors: http://code.google.com/p/smhasher/

How much do you care about the possibility of somebody trying to craft
modules with colliding hashes?