Re: Help with bit-field semantics in C and C++

[Mark Mitchell <mark at codesourcery dot com>]

Gabriel Dos Reis wrote:

> Mark Mitchell <mark@codesourcery.com> writes:
>
>
> [...]
>
> | conversion instructions inserted.  Since EDG passes basically every
> | known testsuite,
>
> That is a very interesting argument.
> Who sits the baby-sitter, e.g. who makes sure that those testsuite are
> enough to make sure that a compiler that passes it is bug-free?
> Actually, by your argument, EDG should stop releasing any version of
> their front-ends -- yet they still release bug-fixes, even thiugh they
> have passed known  testsuites. 
>  
Huh?  That's a reduction-to-absurdity argument.

The people who write testsuites for a living think a lot about corner 
cases and try to write tests that cause compilers to get the corner 
cases wrong.  They go through the standard line-by-line, thinking of 
pathological things.  None of them have ever written the test that David 
is suggesting.  So, that doesn't mean David is wrong, in and of itself; 
he might have thought of something nobody else thought of.  But, I 
certainly consider the fact that no testsuite checks for this case as 
evidence against David's position.

--
Mark Mitchell
CodeSourcery, LLC
(916) 791-8304
mark@codesourcery.com