--- Em qui, 23/10/08, Olin Lathrop <olin_piclist@embedinc.com> escreveu:

> ...
> On the PIC 18 there are separate data and return address
> stacks, so this is
> not a issue.  I didn't realize that all C functions are
> allowed to be called
> with different number of arguments.  Is this really the
> case?  To me this
> seems like a really brain dead choice considering that
> fixed number of
> ...

The problem with C is that the compiler relies only on the function prototy=
pes to check for argument types and number. The prototypes are usually kept=
 in header files ("*.h"), which are source (text) files. If the header file=
 is changed one can foil the compiler and say the function takes any type a=
nd number of arguments he wants.

Hi-Tech PICC has an interesting approach: It embeds in the object files a m=
agic number (signature) that says what type and number of arguments it take=
s and what type it returns. Then the linker catches such errors.

Most compilers will allow you to call a function without a protype acceptin=
g any arguments you give it, but then it issues a warning.

Pascal has a good approach with the Units, that include together the code a=
nd the prototypes for everything.

Regards,

Isaac


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