[PATCH, libgfortran] Add overflow check to xmalloc

[Bernhard Reutner-Fischer]

> >> On Tue, May 20, 2014 at 12:42 AM, Janne Blomqvist
> >> <blomqvist.janne@gmail.com> wrote:
> >>> On Thu, May 15, 2014 at 1:00 AM, Janne Blomqvist
> >>> <blomqvist.janne@gmail.com> wrote:
> >>>> Hi,
> >>>>
> >>>> a common malloc() pattern is "malloc(num_foo * sizeof(foo_t)", that
> >>>> is, create space for an array of type foo_t with num_foo elements.
> >>>> There is a slight danger here in that the multiplication can overflow
> >>>> and wrap around, and then the caller thinks it has a larger array than
> >>>> what malloc has actually created. The attached patch changes the
> >>>> libgfortran xmalloc() function to have an API similar to calloc() with
> >>>> two arguments, and the implementation checks for wraparound.
> >>>
> >>> Hello,
> >>>
> >>> attached is an updated patch which instead introduces a new function,
> >>> xmallocarray, with the overflow check, and leaves the existing xmalloc
> >>> as is. Thus avoiding the extra checking in the common case where one
> >>> of the arguments to xmallocarray would be 1.
> >>>
> >>> Tested on x86_64-unknown-linux-gnu, Ok for trunk?
> >>>

I would prefer if xcmalloc would not be named xmallocarray.

Thanks,

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