Re: memparse(), simple_strtoul() prototypes...

From: Francis Moreau
Date: Tue Feb 20 2007 - 03:19:53 EST

On 2/19/07, Avi Kivity <avi@xxxxxxxxxx> wrote:
Francis Moreau wrote:
>> > unsigned long simple_strtoul(const char *cp, char **endp,unsigned
>> int base)
> hm, I don't get your point. I understand why we cast 'cp' into a (char
> *) but that's not my point. My point is why aren't all function
> parameters are not const ?

'cp' can be passed as const, because simple_strtoul() does not modify
it. 'endp' cannot be passed as const, because simple_strtoul() cannot
know whether the caller would want to modify the string or not.

Whichever way it is written, it is broken. If changed to 'const', it
would preclude the caller from modifying the string if one has a
non-const string. As written, it can silently convert a const string to
a non-const string. However, as written it is (a) standard conforming,
and (b) more useful.

ok I think I finally got it and I agree that both ways are broken.

Maybe changing simple_strtoul() prototype as follow would be better ?

int simple_strtoul(const char *cp, unsigned long *value, unsigned base)

the function would return the number of parsed char, and 'value' would
be the result.
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