Re: LT_AC_PROG_SED

[Ralf Wildenhues]

Hi Gary,

[ eliding the libtool list ]

* Gary V. Vaughan wrote on Fri, Feb 10, 2006 at 11:52:04AM CET:
> Ralf Wildenhues wrote:
> 
> To forestall cries of "not backwards compatible!" from the peanut
> gallery after the release, I'd like to commit the attached patches
> (sorry I took so long to roll it up and post it).  The branch-1-5
> patch addresses your remaining issues with LT_AC_PROG_SED.

Hmm.

> Okay to commit?

Comments inline.  Please note my comments are completely untested,
so please take them with a grain of salt.

Cheers,
Ralf

> Index: ChangeLog
> from  Gary V. Vaughan  <address@hidden>
>       * libtool.m4 (LT_AC_PROG_SED): Rename to AC_PROG_SED and only define
>       if autoconf failed to provide a definition.  AC_SUBST([SED]) for
>       compatibility with future autoconf release of AC_PROG_SED.  Provide
>       an autoupdate alias to LT_AC_PROG_SED for projects that used this
>       undocumented macro.
>  
> Index: libtool-1-5/libtool.m4
> ===================================================================
> --- libtool-1-5.orig/libtool.m4
> +++ libtool-1-5/libtool.m4
> @@ -5987,17 +5987,15 @@ AC_DEFUN([LT_AC_PROG_RC],
>  [AC_CHECK_TOOL(RC, windres, no)
>  ])
>  
> +m4_ifndef([AC_PROG_SED], [
>  ############################################################
>  # NOTE: This macro has been submitted for inclusion into   #
>  #  GNU Autoconf as AC_PROG_SED.  When it is available in   #
>  #  a released version of Autoconf we should remove this    #
>  #  macro and use it instead.                               #
>  ############################################################
> -# LT_AC_PROG_SED
> -# --------------
> -# Check for a fully-functional sed program, that truncates
> -# as few characters as possible.  Prefer GNU sed if found.
> -AC_DEFUN([LT_AC_PROG_SED],
> +
> +AC_DEFUN([AC_PROG_SED],

With old aclocal, this will pull in libtool.m4 for users of AC_PROG_SED.
This is definitely not ok.

>  [AC_MSG_CHECKING([for a sed that does not truncate output])
>  AC_CACHE_VAL(lt_cv_path_SED,
>  [# Loop through the user's path and test for sed and gsed.
> @@ -6047,5 +6045,13 @@ for lt_ac_sed in $lt_ac_sed_list /usr/xp
>  done
>  ])
>  SED=$lt_cv_path_SED
> +AC_SUBST([SED])
>  AC_MSG_RESULT([$SED])
> -])
> +])#AC_PROG_SED
> +])#m4_ifndef
> +
> +# Old name:
> +AU_ALIAS([LT_AC_PROG_SED], [AC_PROG_SED])
> +dnl aclocal-1.4 backwards compatibility:
> +dnl AC_DEFUN([LT_AC_PROG_SED], [])
> +

With old aclocal, this will pull in libtool.m4 for users of
LT_AC_PROG_SED.

That may actually be ok for them, but it won't do what you want:
forward compatiblity plus automatic independence of libtool.m4
without user changes, as soon as autoconf-2.60 is out.  Right?

Ah, maybe you rather want users to switch to AC_PROG_SED, but
help them with the autoupdate note?

> Index: ChangeLog
> from  Gary V. Vaughan  <address@hidden>
>       * libltdl/m4/lt~obsolete (LT_AC_PROG_SED): Removed in favour
>       of...
>       * libltdl/m4/libtool.m4 (LT_AC_PROG_SED): Declarations for
>       compatibility with old versions of libtool, and old versions of
>       aclocal.
> 
> Index: libtool-HEAD/libltdl/m4/libtool.m4
> ===================================================================
> --- libtool-HEAD.orig/libltdl/m4/libtool.m4
> +++ libtool-HEAD/libltdl/m4/libtool.m4
> @@ -6758,6 +6758,11 @@ AC_MSG_RESULT([$SED])
>  ])#AC_PROG_SED
>  ])#m4_ifndef
>  
> +# Old name:
> +AU_ALIAS([LT_AC_PROG_SED], [AC_PROG_SED])

Is it allowed to AU_ALIAS a macro that is not AC_DEFUN'ed?
(I just changed AC_PROG_SED to be m4_defun'ed, not AC_DEFUN'ed).

> +dnl aclocal-1.4 backwards compatibility:
> +dnl AC_DEFUN([LT_AC_PROG_SED], [])

With old aclocal, this will pull in libtool.m4 for users of
LT_AC_PROG_SED.

>  # _LT_CHECK_XSI_SHELL
>  # -------------------
> Index: libtool-HEAD/libltdl/m4/lt~obsolete.m4
> ===================================================================
> --- libtool-HEAD.orig/libltdl/m4/lt~obsolete.m4
> +++ libtool-HEAD/libltdl/m4/lt~obsolete.m4
> @@ -58,7 +58,6 @@ m4_ifndef([AC_LIBTOOL_PROG_COMPILER_PIC]
>  m4_ifndef([AC_LIBTOOL_PROG_LD_SHLIBS],       
> [AU_DEFUN([AC_LIBTOOL_PROG_LD_SHLIBS])])
>  m4_ifndef([AC_LIBTOOL_POSTDEP_PREDEP],       
> [AU_DEFUN([AC_LIBTOOL_POSTDEP_PREDEP])])
>  m4_ifndef([LT_AC_PROG_EGREP],                [AU_DEFUN([LT_AC_PROG_EGREP])])
> -m4_ifndef([LT_AC_PROG_SED],          [AU_DEFUN([LT_AC_PROG_SED])])

Doing this will pull in an older also-installed libtool.m4: some
aclocal versions will not fall for the 1.4 hack above but still won't
see the AU_ALIAS.  Actually, AU_ALIAS isn't matched before 1.9.5.

>  m4_ifndef([_LT_CC_BASENAME],         [AU_DEFUN([_LT_CC_BASENAME])])
>  m4_ifndef([_LT_COMPILER_BOILERPLATE],        
> [AU_DEFUN([_LT_COMPILER_BOILERPLATE])])
>  m4_ifndef([_LT_LINKER_BOILERPLATE],  [AU_DEFUN([_LT_LINKER_BOILERPLATE])])