[lld] Why use PROVIDE_HIDDEN defined symbol in linker script is GLOBAL when partial linking?

[hstk30-hw]

lds:

SECTIONS
{
  . mySec:
  {
    PROVIDE_HIDDEN(__mysec_start = .);
    KEEP (*(SORT(.probs*)))
    PROVIDE_HIDDEN(__mysec_end = .);
  }
};

main.c

extern void *__mysec_start;
extern void *__mysec_end;

int getNum(void) {
    return &__mysec_end - &__mysec_start;
}

int main() {
  return getNum();
}

Command like:

clang -c main.c -o main.o
ld.lld main.o -o main -T lds -r

And the symbol info like:

 8: 0000000000000000     0 NOTYPE  GLOBAL HIDDEN     1 __mysec_end
 9: 0000000000000000     0 NOTYPE  GLOBAL HIDDEN     1 __mysec_start

without -r the output like:

 8: 0000000000000000     0 NOTYPE  LOCAL HIDDEN     1 __mysec_end
 9: 0000000000000000     0 NOTYPE  LOCAL HIDDEN     1 __mysec_start

And ld always LOCAL w/wo -r

gold is GLOBAL with -r.

I'm not found the standard about this (about the bindind of symbol defined in linker script).

[hstk30-hw]

CC @rui314 @MaskRay

[MaskRay]

The generic ABI says:

A hidden symbol contained in a relocatable object must be either removed or converted to STB_LOCAL binding by the link-editor when the relocatable object is included in an executable file or shared object.

lld converts hidden symbols to STB_LOCAL when producing an EXE/DSO. GNU ld and gold don't do this.
(gold seems inconsistent. It creates STB_LOCAL STV_HIDDEN _GLOBAL_OFFSET_TABLE_)

[hstk30-hw]

In my example, the symbol is defined in linker script, not in a relocatable object. It's a trick :)

So, it seems lld not follow the rule. lld should output LOCAL HIDDEN symbol like ld?

[MaskRay]

lld actually follows the rule but GNU ld/gold don't.

Keeping a global symbol in relocatable output allows ld -r a.o b.o -o ab.ro; ld ab.o c.o to have a similar behavior to ld a.o b.o c.o.