Re: ****tability: Harmony between PC and microcontroller

Tomás Ó hÉilidhe <toe@[EMAIL PROTECTED]
> writes:
> On May 6, 12:33 pm, Chris Dollin <chris.dol...@[EMAIL PROTECTED]
> wrote:
>> That just means that those microcontrollers aren't a natural fit
>> to C, so programmers writing looks-like-C for them need to be
>> aware that natural-C idioms might not work as nicely.
>
>
> This is what I'm against. When I first started programming in C for
> embedded systems, I was weary of the compiler's compliance to the

(I presume you mean "wary", not "weary".)

> Standard. I was hesitant to rely on rules from the Standard when it
> came to things like:
>     * Minimum size of integer types

Nitpick: The standard defines minimum ranges for integer types, but
the effect is the same.

I've heard of C-like compilers that provide a type "int" with a range
narrower than -32767 .. +32767.  That's ok, as long as there's no
claim that it conforms to the C standard.  But I would expect the
compiler's do***entation to *clearly* state the ways in which it fails
to conform.

>     * Behaviour of overflow

For floating-point and signed integers, the standard doesn't define
the behavior of overflow.  For unsigned integers, the required
behavior is well defined; it wraps around modulo 2**N.  I'd be
surprised if even a non-conforming C-like compiler didn't do this (it
should be straightforward to implement in hardware).  But again, if
the behavior differs from what the standard specifies, I'd expect it
to be clearly stated in the do***entation.

>     * Existance and usage of a stack

The C standard doesn't even use the word "stack" (and *please* let's
not re-open the argument about what "stack" means).  It does require
that functions can be called recursively.  If the implementation can't
sup****t that, then again, I'd expect that to be clearly do***ented.

[snip]

-- 
Keith Thompson (The_Other_Keith) <kst-u@[EMAIL PROTECTED]
>
Nokia
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