Re: [PATCH, ARM]: Fix diagnostics & disallow ARM instructions on V7M cores

[Paul Brook <paul@codesourcery.com>]

On Thursday 11 May 2006 22:23, Julian Brown wrote:
> + #define THUMB_ONLY      (ARM_EXT_V7 | ARM_EXT_V7M)
> + #define THUMB_ONLY_EXCEPT (ARM_EXT_V7A | ARM_EXT_V7R)

I don't think these are necessary.  In opcode_select we already have:

          if (!ARM_CPU_HAS_FEATURE (cpu_variant, arm_ext_v1))
            as_bad (_("selected processor does not support ARM opcodes"));

That condition should be ok whenever we need to check for a Thumb-only core.

> *************** md_begin (void)
> *** 18396,18401 ****
> --- 18417,18424 ----
>  
>     ARM_MERGE_FEATURE_SETS (cpu_variant, *mcpu_cpu_opt, *mfpu_opt);
>  
> +   autoselect_thumb_from_cpu_variant ();
> +
>     arm_arch_used = thumb_arch_used = arm_arch_none;

Defaulting to thumb mode if a Thumb only core is specified on the commandline 
ok I guess, however...
  
>   #if defined OBJ_COFF || defined OBJ_ELF
> *************** s_arm_cpu (int ignored ATTRIBUTE_UNUSED)
> *** 19457,19462 ****
> --- 19480,19486 ----
>             selected_cpu_name[i] = 0;
>           }
>         ARM_MERGE_FEATURE_SETS (cpu_variant, *mcpu_cpu_opt, *mfpu_opt);
> +         autoselect_thumb_from_cpu_variant ();

I don't think making .arch armv7 imply .thumb is a good idea. 
If we do this we should also make .arch armv4 imply .arm.

Paul