HAVE_ATTR_enabled mishandling?

[Chung-Ju Wu]

On 7/10/13 5:51 AM, David Given wrote:
> I think I have found a bug. This is in stock gcc 4.8.1...
>
> My backend does not use the 'enabled' attribute; therefore the following
> code in insn-attr.h kicks in:
>
>    #ifndef HAVE_ATTR_enabled
>    #define HAVE_ATTR_enabled 0
>    #endif
>
> Therefore the following code in gcc/lra-constraints.c is enabled:
>
>    #ifdef HAVE_ATTR_enabled
>        if (curr_id->alternative_enabled_p != NULL
> 	  && ! curr_id->alternative_enabled_p[nalt])
> 	continue;
>    #endif
>
> ->alternative_enabled_p is bogus; therefore segfault.
>
> Elsewhere I see structures of the form:
>
>    #if HAVE_ATTR_enabled
>    ...
>    #endif
>
> So I think that #ifdef above is a straight typo. Certainly, changing it
> to a #if makes the crash go away...
>

I faced exactly the same problem as yours.

When I was trying to enable LRA on my target, I got segfault as well
because I did not have 'enabled' attribute in my target.md file.

I was told it was due to my faulty md design.  The simplest workaround
is to define 'enabled' attribute so I took it.  But I suspected that
may be a latent issue.

It's so happy to see others have the same question and provide a solution.
Certainly, whether your solution is correct should be reviewed by LRA
maintainer, Vladmir Makarov, so I cc him in the list.


Best regards,
jasonwucj