[PATCH] readelf: Display the base symbol version as empty string

[Fangrui Song]

On Wed, Nov 5, 2025 at 5:20 PM H.J. Lu <hjl.tools@gmail.com> wrote:
>
> Update readelf to display the base symbol version as
>
> Symbol table for image contains 5 entries:
>    Num:    Value          Size Type    Bind   Vis      Ndx Name
>      0: 0000000000000000     0 NOTYPE  LOCAL  DEFAULT  UND
>      1: 0000000000003008     0 OBJECT  GLOBAL DEFAULT   10 bar@@
>      2: 0000000000000000     0 OBJECT  GLOBAL DEFAULT  ABS VERS_1
>      3: 0000000000003008     0 OBJECT  GLOBAL DEFAULT   10 bar@@VERS_1
>      4: 0000000000003000     0 OBJECT  GLOBAL DEFAULT   10 foo@
>
> instead of
>
> Symbol table for image contains 5 entries:
>    Num:    Value          Size Type    Bind   Vis      Ndx Name
>      0: 0000000000000000     0 NOTYPE  LOCAL  DEFAULT  UND
>      1: 0000000000003008     0 OBJECT  GLOBAL DEFAULT   10 bar
>      2: 0000000000000000     0 OBJECT  GLOBAL DEFAULT  ABS VERS_1
>      3: 0000000000003008     0 OBJECT  GLOBAL DEFAULT   10 bar@@VERS_1
>      4: 0000000000003000     0 OBJECT  GLOBAL DEFAULT   10 foo
>
> That is bar@@ and foo@ vs bar and foo.
>
> binutils/
>
> PR binutils/33599
> * readelf.c (process_version_sections): Replace 0x8001 with
> (VERSYM_HIDDEN | VERSYM_BASE).
> (get_symbol_version_string): Likewise.  Return "" for the base
> version.
>
> include/
>
> PR binutils/33599
> * elf/common.h (VERSYM_BASE): New.
>
> ld/
>
> PR binutils/33599
> * testsuite/ld-elf/pr33599.d: New file.
> * testsuite/ld-elf/pr33599.map: Likewise.
> * testsuite/ld-elf/pr33599.s: Likewise.
>
> OK for master?
>
> --
> H.J.

Hmm, I am not sure this readelf change is desired.

.symver bar, bar@@

is invalid assembly syntax, so it seems wise to avoid `bar@@` in readelf output.