PING: [PATCH] Define GEN_AS_CONST_HEADERS when generating header files [BZ #22792]

["H.J. Lu" <hjl dot tools at gmail dot com>]

On Thu, Feb 8, 2018 at 9:58 AM, H.J. Lu <hongjiu.lu@intel.com> wrote:
> Glibc build generates header files to define constants from special .sym
> files.  If a .sym file includes the same header file which it generates,
> it leads to circular dependency.  Define GEN_AS_CONST_HEADERS when
> generating header files to avoid circular dependency.
>
> <tcb-offsets.h> is needed for i686 and it isn't needed for x86-64 at
> least since glibc 2.23.
>
> Tested on i686 and x86-64.
>
> OK for trunk?
>
> H.J.
> ---
>         [BZ #22792]
>         * Makerules ($(common-objpfx)%.h): Pass -DGEN_AS_CONST_HEADERS
>         to $(CC).
>         * sysdeps/unix/sysv/linux/i386/lowlevellock.h: Include
>         <tcb-offsets.h> only if GEN_AS_CONST_HEADERS isn't defined.
>         * sysdeps/unix/sysv/linux/x86_64/lowlevellock.h: Don't include
>         <tcb-offsets.h>.
> ---
>  Makerules                                     | 4 +++-
>  sysdeps/unix/sysv/linux/i386/lowlevellock.h   | 4 +++-
>  sysdeps/unix/sysv/linux/x86_64/lowlevellock.h | 1 -
>  3 files changed, 6 insertions(+), 3 deletions(-)
>
> diff --git a/Makerules b/Makerules
> index ef6abeac6d..10a2e83468 100644
> --- a/Makerules
> +++ b/Makerules
> @@ -276,10 +276,12 @@ ifdef gen-as-const-headers
>  # Generating headers for assembly constants.
>  # We need this defined early to get into before-compile before
>  # it's used in sysd-rules, below.
> +# Define GEN_AS_CONST_HEADERS to avoid circular dependency [BZ #22792].
>  $(common-objpfx)%.h $(common-objpfx)%.h.d: $(..)scripts/gen-as-const.awk \
>                                            %.sym $(common-before-compile)
>         $(AWK) -f $< $(filter %.sym,$^) \
> -       | $(CC) -S -o $(@:.h.d=.h)T3 $(CFLAGS) $(CPPFLAGS) -x c - \
> +       | $(CC) -S -o $(@:.h.d=.h)T3 $(CFLAGS) $(CPPFLAGS) \
> +               -DGEN_AS_CONST_HEADERS -x c - \
>                 -MD -MP -MF $(@:.h=.h.d)T -MT '$(@:.h=.h.d) $(@:.h.d=.h)'
>         sed -n 's/^.*@@@name@@@\([^@]*\)@@@value@@@[^0-9Xxa-fA-F-]*\([0-9Xxa-fA-F-][0-9Xxa-fA-F-]*\).*@@@end@@@.*$$/#define \1 \2/p' \
>                 $(@:.h.d=.h)T3 > $(@:.h.d=.h)T
> diff --git a/sysdeps/unix/sysv/linux/i386/lowlevellock.h b/sysdeps/unix/sysv/linux/i386/lowlevellock.h
> index fb59b57934..9f081e8a05 100644
> --- a/sysdeps/unix/sysv/linux/i386/lowlevellock.h
> +++ b/sysdeps/unix/sysv/linux/i386/lowlevellock.h
> @@ -26,7 +26,9 @@
>  # include <sys/param.h>
>  # include <bits/pthreadtypes.h>
>  # include <kernel-features.h>
> -# include <tcb-offsets.h>
> +# ifndef GEN_AS_CONST_HEADERS
> +#  include <tcb-offsets.h>
> +# endif
>
>  # ifndef LOCK_INSTR
>  #  ifdef UP
> diff --git a/sysdeps/unix/sysv/linux/x86_64/lowlevellock.h b/sysdeps/unix/sysv/linux/x86_64/lowlevellock.h
> index a8bcfbe4a3..eedb6fc990 100644
> --- a/sysdeps/unix/sysv/linux/x86_64/lowlevellock.h
> +++ b/sysdeps/unix/sysv/linux/x86_64/lowlevellock.h
> @@ -26,7 +26,6 @@
>  # include <sys/param.h>
>  # include <bits/pthreadtypes.h>
>  # include <kernel-features.h>
> -# include <tcb-offsets.h>
>
>  # ifndef LOCK_INSTR
>  #  ifdef UP
> --
> 2.14.3
>



-- 
H.J.