Re: [PATCH] PR tdep/9390: Fix possible typo on xstorxstormy16-tdep.c

[Pedro Alves <palves@redhat.com>]

[Adding Corinna, listed as xstormy16 maintainer in MAINTAINERS.
Hi Corinna.  Do we still care about this port?]

The fix makes sense to me, though I know nothing about
xstormy16 either.

Thanks,
Pedro Alves

On 09/16/2014 09:14 PM, Sergio Durigan Junior wrote:
> This patch (probably) fixes the bug described in PR tdep/9390, which
> is about a wrong check in the following code:
> 
>     ...
> 
>     /* optional copying of args in r2-r7 to r10-r13.  */
>     /* Probably only in optimized case but legal action for prologue.  */
>     else if ((inst & 0xff00) == 0x4600	/* 46SD   mov rD, rS */
> 	     && (inst & 0x00f0) >= 0x0020 && (inst & 0x00f0) <= 0x0070
> 	     && (inst & 0x000f) >= 0x00a0 && (inst & 0x000f) <= 0x000d)
>                 ^^^^^^^^^^^^^^^^^^^^^^^^^
>     ...
> 
> This condition will never trigger, and the fix proposed in the bug
> (which made sense to me) was to test against 0x000a.  I tried finding
> documentation about this target, but couldn't find anything.  I don't
> even know if it is still used, but decided to submit the fix anyway.
> 
> Tested on my x86_64 Fedora 20 GNU/Linux.
> 
> gdb/ChangeLog:
> 2014-09-16  Sergio Durigan Junior  <sergiodj@redhat.com>
> 
> 	PR tdep/9390
> 	* xstorxstormy16-tdep.c (xstormy16_analyze_prologue): Fix possible
> 	typo when using logical AND to determine instruction type.
> ---
>  gdb/ChangeLog        | 6 ++++++
>  gdb/xstormy16-tdep.c | 2 +-
>  2 files changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/gdb/ChangeLog b/gdb/ChangeLog
> index 8216274..622976d 100644
> --- a/gdb/ChangeLog
> +++ b/gdb/ChangeLog
> @@ -1,5 +1,11 @@
>  2014-09-16  Sergio Durigan Junior  <sergiodj@redhat.com>
>  
> +	PR tdep/9390
> +	* xstorxstormy16-tdep.c (xstormy16_analyze_prologue): Fix possible
> +	typo when using logical AND to determine instruction type.
> +
> +2014-09-16  Sergio Durigan Junior  <sergiodj@redhat.com>
> +
>  	* objc-lang.c (find_implementation_from_class): Remove dead code.
>  
>  2014-09-16  Sergio Durigan Junior  <sergiodj@redhat.com>
> diff --git a/gdb/xstormy16-tdep.c b/gdb/xstormy16-tdep.c
> index af3ff32..9692742 100644
> --- a/gdb/xstormy16-tdep.c
> +++ b/gdb/xstormy16-tdep.c
> @@ -374,7 +374,7 @@ xstormy16_analyze_prologue (struct gdbarch *gdbarch,
>        /* Probably only in optimized case but legal action for prologue.  */
>        else if ((inst & 0xff00) == 0x4600	/* 46SD   mov rD, rS */
>  	       && (inst & 0x00f0) >= 0x0020 && (inst & 0x00f0) <= 0x0070
> -	       && (inst & 0x000f) >= 0x00a0 && (inst & 0x000f) <= 0x000d)
> +	       && (inst & 0x000f) >= 0x000a && (inst & 0x000f) <= 0x000d)
>  	;
>  
>        /* Optional copying of args in r2-r7 to stack.  */
>