[PATCH] nptl_db: Re-use the ELF-to-abilist converter for ABI checking

[Szabolcs Nagy]

The 06/29/2021 12:13, Florian Weimer wrote:
> The previous approach uses readelf -DWs, which does not produce
> a stable output format (older binutils versions do not include
> symbol version information).  This commit re-uses scripts/abilist.awk
> with a tweak to include GLIBC_PRIVATE symbols.  This awk script
> is based on objdump -T output, which appears to be stable over time.
> 
> For me, this fixes nptl/db-symbols with binutils 2.30.  Also tested in
> the usual way (build-many-glibcs.py is still running, but is looking
> good so far).

thanks, it looks good.

Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>


> 
> ---
>  nptl_db/Makefile       |  9 +++++++--
>  nptl_db/db-symbols.awk | 15 +++++----------
>  scripts/abilist.awk    |  2 +-
>  3 files changed, 13 insertions(+), 13 deletions(-)
> 
> diff --git a/nptl_db/Makefile b/nptl_db/Makefile
> index c04aa6140a..8ad4f90e84 100644
> --- a/nptl_db/Makefile
> +++ b/nptl_db/Makefile
> @@ -54,8 +54,13 @@ tests-special += $(objpfx)db-symbols.out
>  include ../Rules
>  
>  $(objpfx)db-symbols.out: $(objpfx)db-symbols.v.i \
> -			 $(common-objpfx)libc.so
> -	LC_ALL=C $(READELF) -W -D -s $(filter %.so,$^) | $(AWK) -f $< > $@; \
> +			 $(objpfx)libc.symlist-private
> +	LC_ALL=C $(AWK) -f $^ > $@; \
>  	$(evaluate-test)
>  
>  $(objpfx)db-symbols.v.i: db-symbols.awk
> +
> +$(objpfx)libc.symlist-private: $(..)scripts/abilist.awk \
> +  $(common-objpfx)libc.dynsym
> +	LC_ALL=C $(AWK) -v include_private=1 -f $^ > $@T
> +	mv -f $@T $@
> diff --git a/nptl_db/db-symbols.awk b/nptl_db/db-symbols.awk
> index fe90d3b435..67034c3e89 100644
> --- a/nptl_db/db-symbols.awk
> +++ b/nptl_db/db-symbols.awk
> @@ -1,5 +1,5 @@
> -# This script processes the output of 'readelf -W -D -s' on the libc.so
> -# we've just built.  It checks for all the symbols used in td_symbol_list.
> +# This script processes the libc.so abilist (with GLIBC_PRIVATE
> +# symbols included).  It checks for all the symbols used in td_symbol_list.
>  
>  BEGIN {
>  %define DB_MAIN_VARIABLE(name) /* Nothing. */
> @@ -12,18 +12,14 @@ BEGIN {
>     in_symtab = 0;
>  }
>  
> -/Symbol table for image/ { in_symtab=1; next }
> -NF == 0 { in_symtab=0; next }
> -
> -!in_symtab { next }
> -
> -NF >= 8 && $7 != "UND" { seen[$NF] = 1 }
> +/^GLIBC_PRIVATE / {
> +    seen[$2] = 1
> +}
>  
>  END {
>    status = 0;
>  
>    for (s in required) {
> -    s = s "@@GLIBC_PRIVATE"
>      if (s in seen) print s, "ok";
>      else {
>        status = 1;
> @@ -33,7 +29,6 @@ END {
>  
>    any = "";
>    for (s in th_unique) {
> -    s = s "@@GLIBC_PRIVATE"
>      if (s in seen) {
>        any = s;
>        break;
> diff --git a/scripts/abilist.awk b/scripts/abilist.awk
> index a43400d5b4..24a34ccbed 100644
> --- a/scripts/abilist.awk
> +++ b/scripts/abilist.awk
> @@ -55,7 +55,7 @@ $2 == "g" || $2 == "w" && (NF == 7 || NF == 8) {
>    # caused STV_HIDDEN symbols to appear in .dynsym, though that is useless.
>    if (NF > 7 && $7 == ".hidden") next;
>  
> -  if (version == "GLIBC_PRIVATE") next;
> +  if (version == "GLIBC_PRIVATE" && !include_private) next;
>  
>    desc = "";
>    if (type == "D" && ($4 == ".tbss" || $4 == ".tdata")) {
>