bug#22522: Commit b88e9cded7ae3756e3a2ec4a23e8df352a0239f9 breaks emacs dumping for me

[Andy Moreton]

On Wed 03 Feb 2016, Ken Brown wrote:

> On 2/3/2016 3:41 AM, Paul Eggert wrote:
>> Ken Brown wrote:
>>>> I installed the attached patch into the Emacs master, to try to work
>>>> around this problem by putting GCC into C11 mode. Please give it a try.
>>>
>>> No, that didn't fix it.
>> 
>> Can you investigate why not?  The patch should cause 'configure' to put 
>> -stdc=gnu11 into CFLAGS. If you look at config.log, it should have 
>> something like this:
>> 
>> configure:5924: checking for gcc option to enable C11 features
>> ...
>> configure:6146: result: -std=gnu11
>> 
>> If this isn't the result, what is the result and why?
>
> Yes, that's the result. Compiling with that option caused __STDC_VERSION__ to
> be defined as 201112L. But it didn't affect __ISO_C_VISIBLE, which is what
> guards the declaration of aligned_alloc.
>
>> I'd rather not go that route, as __ISO_C_VISIBLE is supposed to be private.
>> I installed the attached patch instead; please give it a try.
>
> We're almost there.  After your change, I get the following in config.h:
>
> /* Define to 1 if you have the declaration of `aligned_alloc', and to 0 if you
>    don't. */
> #define HAVE_DECL_ALIGNED_ALLOC 0
>
> So we need the following additional change:
>
> diff --git a/src/lisp.h b/src/lisp.h
> index a99002b..c8363be 100644
> --- a/src/lisp.h
> +++ b/src/lisp.h
> @@ -3775,7 +3775,7 @@ INLINE void (check_cons_list) (void) { 
> lisp_h_check_cons_list (); }
>  #if !defined DOUG_LEA_MALLOC && !defined HYBRID_MALLOC && !defined 
> SYSTEM_MALLOC
>  extern size_t __malloc_extra_blocks;
>  #endif
> -#ifndef HAVE_DECL_ALIGNED_ALLOC
> +#if !HAVE_DECL_ALIGNED_ALLOC
>  extern void *aligned_alloc (size_t, size_t) ATTRIBUTE_MALLOC_SIZE ((2));
>  #endif
>  extern void malloc_enable_thread (void);
>

With this change applied to changeset 5fcd89f52ec6, I have successfully built:
  64bit cygwin w32
  64bit mingw64
  32bit mingw32
  32bit mingw32 --with-wide-int

Thanks Ken (and Paul) for sorting this out.

   AndyM