[PATCH] gas: fix silent failure of .cfi_sections .sframe on unsupported targets

[Jens Remus]

On 3/10/2026 7:07 AM, Indu Bhagat via Binutils wrote:
> [Resending as I messed up one of the email in the to list in the
> previous attempt].
> 
> Starting in Binutils 2.46, the .cfi_sections .sframe directive failed
> silently when targeting unsupported architectures (e.g., i386 or even
> x32 on x86_64).  This happened because the sframe_as_bad macro only
> checked for the command-line flag --gsframe (GEN_SFRAME_ENABLED) and
> ignored the explicit request via the assembler directive
> (CFI_EMIT_sframe).
> 
> This patch ensures that an error is emitted (for unsupported targets) if
> SFrame is requested via either the command line or the .cfi_sections
> directive, while maintaining silence for 'opportunistic' sframe
> generation (GEN_SFRAME_CONFIG_ENABLED).
> 
> Add two testcases:
>   - cfi-sframe-x86_64-err-1.d: usage of --32 with .cfi_sections .sframe,
>   - cfi-sframe-x86_64-err-2.d: usage of --gsframe --32 without
>     .cfi_sections .sframe
> GAS is expected to error out in both the cases.
> 
> This fixes PR gas/33962 - .cfi_sections directive with .sframe on
> unsupported targets does not error.
> 
> gas/
> 	PR gas/33962
> 	* dw2gencfi.c (dot_cfi_sections): Ensure as_bad is called if
> 	SFrame was explicitly requested via directive.
> 	* gen-sframe.h: Remove sframe_as_bad macro.
> gas/testsuite/
> 	PR gas/33962
> 	* gas/cfi-sframe/cfi-sframe-x86_64-err-1.s: New test.
> 	* gas/cfi-sframe/cfi-sframe-x86_64-err-1.d: New test.
> 	* gas/cfi-sframe/cfi-sframe-x86_64-err-2.s: New test.
> 	* gas/cfi-sframe/cfi-sframe-x86_64-err-1.d: New test.
> 	* gas/cfi-sframe/cfi-sframe.exp: Run the new tests.

Thank you for fixing this issue!


> diff --git a/gas/dw2gencfi.c b/gas/dw2gencfi.c

> @@ -2620,9 +2620,18 @@ cfi_finish (void)
>  	}
>        else
>  #endif
> -	/* Avoid erroring with DEFAULT_SFRAME for non-default options, like
> -	   -32 on x86_64.  */
> -	sframe_as_bad ("%s", _(".sframe not supported for target"));
> +	/* Issue an error for unsupported targets, like --32 on x86_64.  Avoid
> +	   erroring when default-enabled at configure-time though, because we
> +	   interpret default-enabled as "opportunistic SFrames".  Users don't
> +	   want to be bothered by something preventing emission of SFrames in
> +	   such a case.  */
> +	{
> +	  if (flag_gen_sframe == GEN_SFRAME_ENABLED

This issues an error for --gsframe[-N].

> +	      || ((all_cfi_sections & CFI_EMIT_sframe) != 0
> +		  && flag_gen_sframe != GEN_SFRAME_DISABLED
> +		  && flag_gen_sframe != GEN_SFRAME_CONFIG_ENABLED))

IIUC this issues an error for .cfi_sections .sframe, but only if not
--gsframe=no, which takes precedence, and not 'opportunistic' SFrame
generation (GEN_SFRAME_CONFIG_ENABLED).

Why should .cfi_sections .sframe be ignored when used with
'opportunistic' SFrame generation (GEN_SFRAME_CONFIG_ENABLED)?

> +	    as_bad (_(".sframe not supported for target"));
> +	}
>      }
>  
>    if ((all_cfi_sections & CFI_EMIT_debug_frame) != 0)

> diff --git a/gas/gen-sframe.h b/gas/gen-sframe.h

> @@ -21,16 +21,6 @@
>  #ifndef GENSFRAME_H
>  #define GENSFRAME_H
>  
> -/* Errors shouldn't be emitted either if SFrames are default-enabled, as
> -   we interpret default-enabled as "opportunistic SFrames".  Users don't
> -   want to be bothered by something preventing emission of SFrames in
> -   such a case.  */
> -#define sframe_as_bad(format, ...) \
> -  do {					       \
> -    if (flag_gen_sframe == GEN_SFRAME_ENABLED) \
> -      as_bad (format, __VA_ARGS__);            \
> -  } while (0)
> -
>  /* The entity is not tracked.  */
>  #define SFRAME_FRE_ELEM_LOC_NONE	0
>  /* The location of the tracked entity is based on a register.  May or may not
Thanks and regards,
Jens
-- 
Jens Remus
Linux on Z Development (D3303)
jremus@de.ibm.com / jremus@linux.ibm.com

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