Re: [PIC] Learning C

With many embedded compilers, x may or may not be on the stack, as the
compiler will, in some cases, use non-stack memory for local variables.
This is especially true on smaller microcontrollers with limited stack
space.

One would need to read the compiler manual to determine if x will always be
on the stack,  whether there is a way to force x to be on the stack,  or if
there is a compiler specific way to get the stack pointer.

On Sat, Nov 16, 2024, 4:09 AM smplx <[email protected]> wrote:

> write a function:
>
> void * get_stack_ptr(void)
> {
>         int x;
>
>         return &x;
> }
>
> This will return the address of the local variable x which will be on the
> stack.
>
> use it as:
>
>         if ((unsigned long)get_stack_ptr() == (unsigned long)fixed_value+N)
>
> // where N is a constant TBD (around +/- 4 to 12)
>
>
> On Fri, 15 Nov 2024, David VanHorn wrote:
>
> > Same here. I can work with c fairly well, but some things seem unusually
> > difficult in c.  Like comparing the current value of the stack pointer
> to a
> > fixed value ( used in my sanity check routine)  I assume there is a way
> to
> > get there.
> >
> > On Sun, Nov 10, 2024, 11:34 AM David C Brown <[email protected]> wrote:
> >
> >> Although I enjoy programming in Assembler, the fact that so many
> libraries
> >> abd code examples are in C I think that the time has come for me to
> learn
> >> that language.
> >>
> >> Any advice on how to do that would be welcomed, be it a book or online
> >> resources.
> >> I am a competent programmer having programmed in  with Forth, Fortran.
> >> \Pascal, Visual basic
> >> __________________________________________
> >> David C Brown
> >> 43 Bings Road
> >> Whaley Bridge
> >> High Peak                           Phone: 01663 733236
> >> Derbyshire                eMail: [email protected]
> >> SK23 7ND          web: www.bings-knowle.co.uk/dcb
> >> <http://www.jb.man.ac.uk/~dcb>
> >>
> >>
> >>
> >> *Sent from my etch-a-sketch*
> >> --
> >> http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive
> >> View/change your membership options at
> >> https://mailman.mit.edu/mailman/listinfo/piclist
> >>
> > --
> > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive
> > View/change your membership options at
> > https://mailman.mit.edu/mailman/listinfo/piclist
> --
> http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive
> View/change your membership options at
> https://mailman.mit.edu/mailman/listinfo/piclist
>
-- 
http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive
View/change your membership options at
https://mailman.mit.edu/mailman/listinfo/piclist