expand_expr sign extension problem.

[Mark Mitchell]

>>>>> "Robert" == Robert Lipe <robertlipe@usa.net> writes:

    Robert> HOWEVER, looking through the list of targets that set
    Robert> this, it looks like they're all trying to circumvent the
    Robert> same problem and have reasonably well respected compilers.
    Robert> Since the code is relying on implementation-defined
    Robert> behaviour, shouldn't we fix the code instead of inserting
    Robert> more nasty comments about non-GCC host compilers?

Yes.  It's unfortunate, but true -- you really have to use an unsigned
int, rather than an enum, for this kind of thing to get portable code.

However, we can probably have our cake and eat it to by using
`autoconf' to detect the properties of the host compiler in this
respect.  There's no cross-compiler issue; we know what GCC will do,
so we're only interested in the compiler used to build stage1.  Sound
right?

--
Mark Mitchell                   mark@codesourcery.com
CodeSourcery, LLC               http://www.codesourcery.com