[PATCH] malloc: fix undefined behavior in obstack.h [BZ #32393]

[Paul Eggert]

On 2025-04-28 20:39, Collin Funk wrote:

> +# define PTR_UINT_TYPE __UINTPTR_TYPE__

Let's call this new macro __PTR_UINT_TYPE instead, to avoid namespace 
pollution.


> +#define __PTR_ALIGN(B, P, A) \
> +  (sizeof (PTR_INT_TYPE) < sizeof (void *) \
> +   ? (B) + (((P) - (B) + (A)) & ~(A))      \
> +   : (P) + ((- (PTR_UINT_TYPE) (P)) & (A)))

This collides with Gnulib, which needs to do this a different way to 
avoid a compiler error with Oracle Developer Studio. Although admittedly 
it'll take a bit of work to merge with Gnulib, let's not make merging 
harder.

How about the attached patch instead?
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