Stanislav Sedov schrieb:
On Sun, 17 May 2009 14:36:03 +0200
Christoph Mallon <christoph.mal...@gmx.de> mentioned:
Aliasing behavior is stritcly described in
ISO C99 standard, so there's a good point to enforcing strict-aliasing clear
code in our kernel.
If you like this addition because of this reason, I have to disappoint
you: This addition has absolutly *nothing* to do with strict-aliasing.
I didn't meant I like this change only from aliasing point of view: certianly,
the code readability argument is very important. But this change also
works towards the strict aliasing problem solving too: there's just
a less chance someone will reuse a variable, address of which was
previously taken.
Something like this would violate strict-aliasing:
int i;
short* p = (short*)&i;
A short pointer may never point at an int object (ISO/IEC 9899:1999 (E)
ยง6.5:7).
The suggested paragraph has nothing to do with strict-aliasing. It's
"just" about reusing the same variable in different contexts. Reusing
the same variable in different contexts is bad, because it's harder for
a human reader to identify the def-use-chains and additionally if the
address of the variable has escaped (just a "normal" alias problem,
nothing about type-punning and strict-aliasing) the generated code will
be worse.
Please, can we stop this now? It was already rejected. It's a pity, but
maintaining status quo for style(9) seems to be too holy. *sigh*
Christoph
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