Re: git: 51e8e8b0f369 - main - Merge commit e24f90190c77 from llvm git (by Brad Smith):

On Nov 7, 2025, at 23:03, Mark Millard <marklmi@yahoo.com> wrote:

> On Nov 7, 2025, at 19:51, Mark Millard <marklmi@yahoo.com> wrote:
> 
>> Dimitry Andric <dim_at_FreeBSD.org> wrote on
>> Date: Thu, 06 Nov 2025 15:56:54 UTC :
>> 
>>> On 5 Nov 2025, at 08:56, Herbert J. Skuhra <herbert@gojira.at> wrote:
>>>> 
>>>> On Fri, 31 Oct 2025 14:48:06 +0100, Jose Luis Duran wrote:
>>>>> 
>>>>> On Wed, Oct 29, 2025 at 3:50 PM Dimitry Andric <dim@freebsd.org> wrote:
>>>>>> 
>>>>>> The branch main has been updated by dim:
>>>>>> 
>>>>>> URL: https://cgit.FreeBSD.org/src/commit/?id=51e8e8b0f36933814b1be08913857727876aece5
>>>>>> 
>>>>>> 
>> . . .
>>>>>> 
>>>>>> Merge commit e24f90190c77 from llvm git (by Brad Smith):
>>>>>> 
>>>>>> [Driver] Enable outline atomics for FreeBSD/aarch64 (#156089)
>>>>>> 
>>>>>> The compiler_rt helper functions have been built since 12.4, 13.1, 14
>>>>>> and anything newer.
>>>>>> 
>>>>>> 
>> . . .
>>>>> I'm sure you're probably aware by now, but aarch64 builds are failing
>>>>> after this commit:
>>>>> 
>>>>> https://ci.freebsd.org/job/FreeBSD-main-aarch64-build/33100/
>>>> 
>>>> I am now getting this error on stable/15 (aarch64) after this change was
>>>> reverted in f6a81b18a467.
>>>> 
>>>> I have already tried:
>>>> 
>>>> % rm -rf /usr/obj/usr
>>>> % rm -rf ~/.cache/ccache
>>>> % make SRCCONF=/dev/null __MAKE_CONF=/dev/null buildworld
>>>> 
>>>> I am now trying to rebuild world with llvm19 from ports.
>>> 
>>> I have repeatedly tried to reproduce this problem, but I have been unsuccessful.
>> 
>> I tried to set up a simple context to experiment with but ended up
>> blocked for what I intended. Nothing blocked making a .o for
>> which:
>> 
>>    6: 0000000000000000     4 FUNC    GLOBAL HIDDEN      2 shared_static_routine
>> 
>> Nothing blocked making a .a for which:
>> 
>>    6: 0000000000000000     4 FUNC    GLOBAL HIDDEN      2 shared_static_routine
>> 
>> But every one of my attempts to form a .so with such a GLOBAL HIDDEN status
>> based on the .a instead ended up with the likes of:
>> 
>>   30: 0000000000010538     4 FUNC    LOCAL  HIDDEN     12 shared_static_routine
>> 
>> So I did not get to the stage of a program that uses a .so with GLOBAL HIDDEN
>> status involved.
>> 
>> I tried commands that used each of: /usr/bin/ld ,  /usr/bin/ld.lld ,
>> /usr/local/bin/ld.bfd , and /usr/local/bin/aarch64-unknown-freebsd16.0-ld .
>> 
>> I did similarly on amd64.
>> 
>> All of them converted the GLOBAL to be a LOCAL in the .so .
>> 
>> The context used is main 16.
>> 
>> It looks like the toolchain is deliberately avoiding generating the
>> GLOBAL HIDDEN combination in the .so .
>> 
>>> If anybody has a system where this reliably occurs, and can give me access to it (no privileged user needed, as long as git is installed), that would be nice.
> 
> 
> Turns out that my intended test was based on a partial
> misinterpretation of the original error messages. I'll
> need to set up a somewhat different test later.
> 

Here is the small example context I came up with to test. I show
commands to use in comments for each of the 3 tiny source files.


File #1 of 3:

// shared_static_routine.c :

// cc -std=c17 -Wpedantic -Wall -o shared_static_routine.o -fPIC -c shared_static_routine.c -fvisibility=internal
// ar rcs libstatic_routine.a shared_static_routine.o

// Note: Ends up with GLOBAL binding and HIDDEN visibility in libstatic_routine.a


void shared_static_routine(void) {}


File #2 of 3:

// shared_static_referencing_routine.c :

// BAD:  cc -shared -fPIC -Wl,-soname,libshared_routine.so -o libshared_routine.so                      shared_static_referencing_routine.c
// vs.
// GOOD: cc -shared -fPIC -Wl,-soname,libshared_routine.so -o libshared_routine.so -L. -lstatic_routine shared_static_referencing_routine.c


extern void shared_static_routine(void);

void shared_static_referencing_routine(void) { shared_static_routine(); }


File #3 of 3:

// shared_routine_main.c :

// cc -o shared_routine_main.o -fPIC -c shared_routine_main.c
// Then . . .

// For good libshared_routine.so case:
// SUFFICIENT:
// cc -o shared_routine_main   -fPIC    shared_routine_main.o -L.                  -lshared_routine -Wl,-rpath=.
// ALSO WORKS:
// cc -o shared_routine_main   -fPIC    shared_routine_main.o -L. -lstatic_routine -lshared_routine -Wl,-rpath=.

// For the bad libshared_routine.so case, the SUFFICIENT case above reports:
//
// ld: error: undefined reference: shared_static_routine
// >>> referenced by ./libshared_routine.so (disallowed by --no-allow-shlib-undefined)
// cc: error: linker command failed with exit code 1 (use -v to see invocation)

// For the bad libshared_routine.so case, the ALSO WORKS case above reports:
//
// ld: error: non-exported symbol 'shared_static_routine' in './libstatic_routine.a(shared_static_routine.o)' is referenced by DSO './libshared_routine.so'
// cc: error: linker command failed with exit code 1 (use -v to see invocation)


extern void shared_static_referencing_routine(void);

int main(void) { shared_static_referencing_routine(); }


===
Mark Millard
marklmi at yahoo.com