[M3devel] interesting osf cc option for uninitialized variables

[Rodney M. Bates]

Jay K wrote:
>   -trapuv
>       Forces all uninitialized stack variables to be initialized with
>       0xfff58005fff58005. When this value is used as a floating-point vari-
>       able, it is treated as a floating-point NaN and causes a floating-point
>       trap.  When it is used as a pointer, an address or segmentation viola-
>       tion usually occurs.

In the case of a pointer, doing this would violate the Modula-3 language rule
that all variables are initialized to a bit pattern that represents a valid
member of the variable's type.  For a pointer, this would have to be either
the address of an allocated heap object or NIL.  Only the NIL makes any sense.

I like the idea for floats, though, and I consider a NaN to be a valid member
of the type.

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> Relates to recent discussion.
> This should probably be how longreals are initialize for this target.
> Though in reality I'm not very motivated to make this target esp. better than any others.
> It is interesting to see though what features people have put into C compilers.
> 
> 
>  - Jay
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