[COMMITTED] gas: sframe: do not test whether offsetT exceeds INT64_MIN..INT64_MAX

[Jens Remus]

On 1/13/2026 4:52 PM, Jan Beulich wrote:
> On 13.01.2026 16:46, Jens Remus wrote:
>> On 1/13/2026 4:37 PM, Jan Beulich wrote:
>>> On 13.01.2026 16:27, Jens Remus wrote:
>>>> On 1/13/2026 2:59 PM, Jan Beulich wrote:
>>>>> On 13.01.2026 14:24, Jens Remus wrote:
>>>>>> A value of type offsetT, which is either a signed 32-bit or 64-bit
>>>>>> integer, cannot exceed the range of INT64_MIN..INT64_MAX.  This
>>>>>> resolves the following compile error:
>>>>>>
>>>>>> ../../binutils-gdb/gas/gen-sframe.c: In function ‘get_offset_size_in_bytes’:
>>>>>> ../../binutils-gdb/gas/gen-sframe.c:213:45: error: comparison is always true due to limited range of data type [-Werror=type-limits]
>>>>>>   213 |   else if ((sizeof (offsetT) > 4) && (value <= INT64_MAX && value >= INT64_MIN))
>>>>>>       |                                             ^~
>>>>>> ../../binutils-gdb/gas/gen-sframe.c:213:67: error: comparison is always true due to limited range of data type [-Werror=type-limits]
>>>>>>   213 |   else if ((sizeof (offsetT) > 4) && (value <= INT64_MAX && value >= INT64_MIN))
>>>>>
>>>>> This same error ...
>>>>>
>>>>>> --- a/gas/gen-sframe.c
>>>>>> +++ b/gas/gen-sframe.c
>>>>>> @@ -210,7 +210,7 @@ get_offset_size_in_bytes (offsetT value)
>>>>>>      size = 2;
>>>>>>    else if (value <= INT32_MAX && value >= INT32_MIN)
>>>>>
>>>>> ... will trigger here on a !BFD64 build.
>>>>
>>>> Argh!  Good catch! Thanks for letting me know!  How do I resolve this
>>>> properly?  Shall I commit another fix "gas: sframe: do not test whether
>>>> 32-bit offsetT exceeds INT32_MIN..INT32_MAX" or shall I better revert
>>>> both commits and start fresh with a v3 review of the initial patch?
>>>
>>> Incrementally is fine with me.
>>>
>>>> I propose the following as solution:
>>>>
>>>>   if (value <= INT8_MAX && value >= INT8_MIN)
>>>>     size = 1;
>>>>   else if (value <= INT16_MAX && value >= INT16_MIN)
>>>>     size = 2;
>>>>   else if ((sizeof (offsetT) == 4) || (value <= INT32_MAX && value >= INT32_MIN))
>>>
>>> Depending on the internal workings of compilers, this may still trigger
>>> the same diagnostic. I.e. depending on whether the rhs of the || is
>>> eliminated ahead of or after when these kinds of warnings are issued.
>>> A pre-processor conditional involving BFD64 may be better.
>>
>> Is the following patch ok?
> 
> In principle yes; the part I need to defer to Indu or you is whether ...
> 
>> --- a/gas/gen-sframe.c
>> +++ b/gas/gen-sframe.c
>> @@ -208,10 +208,15 @@ get_offset_size_in_bytes (offsetT value)
>>      size = 1;
>>    else if (value <= INT16_MAX && value >= INT16_MIN)
>>      size = 2;
>> +#ifdef BFD64
>>    else if (value <= INT32_MAX && value >= INT32_MIN)
>>      size = 4;
>> -  else if (sizeof (offsetT) > 4)
>> +  else
>>      size = 8;
>> +#else
>> +  else
>> +    size = 4;
>> +#endif
> 
> ... 8-byte sizes really are entirely impossible to use when !BFD64. Since
> it's an offsetT that is passed in, this would seem logical, but I'd rather
> have Indu / you double-check.

Condensed excerpt from gas/as.h:

#ifdef BFD64
typedef int64_t bfd_signed_vma;
#else /* not BFD64  */
typedef int32_t bfd_signed_vma;
#endif /* not BFD64  */

typedef bfd_signed_vma offsetT;

If BFD64, then offsetT is a signed 64-bit integer.  Otherwise it is a
signed 32-bit integer.  As a result it is impossible for !BFD64 to have
a 64-bit offsetT.

Or were you concerned whether SFrame would be broken for !BFD64 targets
in general?  AFAIK SFrame does only allow 8-bit, 16-bit, and 32-bit
SFrame offsets.  64-bit ones are not supported:

Excerpt from gas/gen-sframe.c:

#define SFRAME_FRE_OFFSET_FUNC_MAP_INDEX_1B  0 /* SFRAME_FRE_OFFSET_1B.  */
#define SFRAME_FRE_OFFSET_FUNC_MAP_INDEX_2B  1 /* SFRAME_FRE_OFFSET_2B.  */
#define SFRAME_FRE_OFFSET_FUNC_MAP_INDEX_4B  2 /* SFRAME_FRE_OFFSET_4B.  */
#define SFRAME_FRE_OFFSET_FUNC_MAP_INDEX_8B  3 /* Not supported in SFrame.  */

Regards,
Jens
-- 
Jens Remus
Linux on Z Development (D3303)
jremus@de.ibm.com / jremus@linux.ibm.com

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