Further observations regarding alloca on i586-pc-linux-gnu

[Martin von Loewis]

> "Full expression" isn't a term I'm familiar with.  

This is a term from the ISO C++ standard, 1.8 [intro.execution]/12

>> A <em>full­expression</em> is an expression that is not a
>> subexpression of another expression. If a language construct is
>> defined to produce an implicit call of a function, a use of the
>> language construct is considered to be an expression for the
>> purposes of this definition.

> It seems that alloca must be the first thing after a sequence point.
> How to enforce or even warn about this I have absolutely no idea.

Yes, it would be tricky to explain under what circumstances it works
and when it doesn't. If we'd enforce a rule, it would probably outlaw
cases that do work right now. So it seems more reasonable to support
it everywhere.

Martin