Strange message seen on FreeBSD 14.0 amd64

Dennis Clarke dclarke at
Wed Jul 12 10:39:29 CEST 2023

On 7/11/23 21:30, Jacob Bachmeyer wrote:
> Dennis Clarke via Gnupg-users wrote:
>> Dear GnuPG type folks :
>>     I don't know what this means. Can we just compile with a decent C
>>  compiler such as the LLVM/Clang in FreeBSD ?
>> [...]
>>         Libgcrypt v1.10.2 has been configured as follows:
>> [...]
>>    Please not that your compiler does not support the GCC style
>>    aligned attribute. Using this software may evoke bus errors.
>> hydra$
>> So what does that mean ? I *must* use GCC to compile this source ?
> It means that the sources use a GNU extension that configure has 
> detected that Clang does not properly implement.  The specific example 
> cited ("aligned") should be non-critical for you, since you are running 
> on AMD64 and that architecture does not actually require proper 
> alignment.  The resultant executables should work in your case, but at 
> reduced performance (unaligned accesses are permitted on x86-64, but are 
> slower than aligned accesses) unless SSE (which *does* have hard 
> alignment requirements) is used.  Since I note that you are disabling 
> the use of assembler modules, SSE will probably *not* be used in your 
> executable.
> In short, try it---if it works for you, great!  If GPG crashes with 
> SIGBUS, try rebuilding it with GCC before reporting a bug in GPG.  If it 
> works when built with GCC, you have found a bug (a missing feature that 
> Clang claims to have) in Clang.  Clang typically defines __GNUC__, thus 
> claiming to support GNU extensions, so this is a bug in Clang if your 
> Clang-compiled GPG does not work.
> -- Jacob

Wonderful!  Thank you for the detailed reply as well as the comfort that
this should "just work"(tm) or not. I did disable the asm goodies as I
wanted to easily ( trivially? ) be able to single step around in there
with gdb.

So then, phasers on stun and I will go forth with reckless abandon and
see what dumps core and SIGSEGBEER. Or not.

Dennis Clarke
Belt and suspenders suggested.

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