Use a large enough variable in CompilationCache::LookupScript to avoid overfl...

Use a large enough variable in CompilationCache::LookupScript to avoid overflow.

[Kasper Lund, 2009-05-19 05:40:47]

LGTM. Does this CL completely fix
http://code.google.com/p/v8/issues/detail?id=347

[Søren Thygesen Gjesse, 2009-05-19 06:27:22]

http://codereview.chromium.org/115500/diff/1/2
File src/compilation-cache.cc (right):

http://codereview.chromium.org/115500/diff/1/2#newcode141
Line 141: int generation = static_cast<int>(SCRIPT);  // First generation.
Please add a comment here to say that using int is to curcumvent a bug in gcc
x.y.z, otherwise some other person might change it back.

[Evan Martin, 2009-05-19 17:23:48]

I believe part of the reason gcc requires casts between int and enum is because
it wants to be able to do tricks that produce problems like the above bug.

If v8 relies on behaviors like the one this bug is about, maybe the compiler
flag to force large enums is better?  It looks like it's "-fno-short-enums"

[Lei Zhang, 2009-05-19 19:06:12]

Added comment. Someone from the v8 team probably need to commit this and then
upstream it to Chromium. (at least that's what ager did for my last v8 patch.)

I think -fno-short-enums is on by default. Passing this switch doesn't fix the
minimal test case.

[Kasper Lund, 2009-05-20 06:47:25]

Submitted (slightly modified) as bleeding_edge@2004.