Re: Replace mh_xmalloc() with mh_xcalloc() (previously "[mmh] Future work")

[Philipp Takacs]

[2016-03-14 09:29] m...@mmmmarascio.xyz
> scrīpsit markus schnalke <mei...@marmaro.de>:
> 
> > [2016-03-13 12:46] m...@mmmmarascio.xyz
> > > 
> > > As suggested, the attached patch changes calls to mh_xmalloc() into calls
> > > to mh_xcalloc().
> > 
> > If feasable, I would suggest, to apply the changes in two commits:
> > 
> > 1) replace mh_xmalloc() with mh_xcalloc()
> > 2) remove the casts
> 
> Thanks for the feedback.  The attached patch accomplishes the first of
> these two suggested commits.  It leaves existing casts alone and it leaves
> the parentheses used with sizeof alone.

Thanks for the work, it's committed.

Do you have a patch, which removes the casts?

[2016-03-13 12:46] m...@mmmmarascio.xyz
>
> But I don't understand the idea of an mh_xfree(void **).  Would you mind
> explaining the idea further?  Would the mh_xfree() be used everywhere
> instead of free()?  If I understand more, I may be able to complete the task.

After a discussion with Markus we have decided to call this function better
mh_free0(void *). The idea is to have a function which not only frees the
memory, it should also set the pointer to NULL. An example implementation
is attached.

With this function following code should run without a problem:

char *ptr = mh_xcalloc(42, sizeof(char *));
//do work
mh_free0(&ptr);
assert(ptr == NULL);

Philipp

#include <stdlib.h>

void
mh_free0(void *ptr)
{
	void **pointer = ptr;
	free(*pointer);
	*pointer = NULL;
}

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