Re: Bigger picture of automake variables

[LCID Fire]

Ralf Wildenhues wrote:
> [ moving from automake@ ]
> 
> Hello,
> 
> * LCID Fire wrote on Sun, Dec 14, 2008 at 07:51:07PM CET:
>> Ralf Wildenhues wrote:
>>> Elsewhere, flags like AM_LDFLAGS are denoted as global.  In that case,
>>> it is meant to say that, unlike program_LDFLAGS, which applies to
>>> 'program' only, the flags apply to all binaries created by this
>>> Makefile.am (that themselves don't have per-target flags which override
>>> the "global" AM_LDFLAGS).  Makes sense a bit?
>> IMO global is used incorrectly here because it is just per Makefile.
>> Global initially made me think it really is for all Makefiles.
> 
> Good point. WDYT about the patch below?
Definitely much better than before. I have some proposes though.

> Can I get a real name for THANKS?
LCID Fire or Andreas Bergmeier - whatever you like

>> So basically variables are not ever transported between Makefiles.
> Correct.
Is this written down somewhere on the docs?

> Well, what really happens is that, with
>   AC_SUBST([VARIABLE])
> 
> in configure.ac, and
>   VARIABLE = my value from Makefile.am
> 
> in Makefile.am, the Makefile.in will contain
> 
>   VARIABLE = @VARIABLE@
>   ...
>   VARIABLE = my value from Makefile.am
> 
> and thus the latter wins.
I think this is a candidate for the docs.

> 
>>> Hope that helps.
>> Thanks, helped a great deal. These concepts were not really obvious to
>> me when reading the documentation.
> 
> Good documentation patches are always welcome.  :-)
Make the docs a wiki and I'll be eager to update the docs :)

>     Do not use 'global' for makefile-wide settings.
>     
>     * doc/automake.texi (Linking, Libtool Flags)
>     (Program and Library Variables, Flag Variables Ordering):
>     Reword instances of `global variables' that really mean
>     makefile-wide ones.
>     Report by LCID Fire <address@hidden>.
> 
> diff --git a/doc/automake.texi b/doc/automake.texi
> index fa0a277..e7ae93b 100644
> --- a/doc/automake.texi
> +++ b/doc/automake.texi
> @@ -4586,9 +4586,8 @@ Sometimes, multiple programs are built in one directory 
> but do not share
>  the same link-time requirements.  In this case, you can use the
>  @address@hidden variable (where @var{prog} is the name of the
>  program as it appears in some @code{_PROGRAMS} variable, and usually
> -written in lowercase) to override the global @code{LDADD}.  If this
> -variable exists for a given program, then that program is not linked
> -using @code{LDADD}.
> +written in lowercase) to override @code{LDADD}.  If this variable exists
> +for a given program, then that program is not linked using @code{LDADD}.
>  @vindex maude_LDADD
>  
>  For instance, in GNU cpio, @code{pax}, @code{cpio} and @code{mt} are
> @@ -5256,8 +5255,8 @@ Libtool Manual} for more options) should appear before 
> the mode
>  selection on the command line; in @file{Makefile.am}s they should
>  be listed in the @address@hidden variable.
>  
> -If @address@hidden is not defined, the global
> address@hidden variable is used instead.
> +If @address@hidden is not defined, then the variable
> address@hidden is used instead.
>  
>  These flags are passed to libtool after the @address@hidden
>  option computed by Automake (if any), so
> @@ -5495,11 +5494,11 @@ of any library built by your package.  Doing so will 
> ensure that
>  
>  @item maude_LDFLAGS
>  This variable is used to pass extra flags to the link step of a program
> -or a shared library.  It overrides the global @code{AM_LDFLAGS} variable.
> +or a shared library.  It overrides the @code{AM_LDFLAGS} variable.
>  
>  @item maude_LIBTOOLFLAGS
>  This variable is used to pass extra options to @command{libtool}.
> -It overrides the global @code{AM_LIBTOOLFLAGS} variable.
> +It overrides the @code{AM_LIBTOOLFLAGS} variable.
>  These options are output before @command{libtool}'s @address@hidden
>  option, so they should not be mode-specific options (those belong to
>  the compiler or linker flags).  @xref{Libtool Flags}.
> @@ -10768,7 +10767,7 @@ has neither @code{AM_} nor per-target cousin.
>  Finally you should not think either that the existence of a per-target
>  variable implies that of an @code{AM_} variable or that of a user
>  variable.  For instance, the @code{mumble_LDADD} per-target variable
> -overrides the global @code{LDADD} variable (which is not a user
> +overrides the makefile-wide @code{LDADD} variable (which is not a user
>  variable), and @code{mumble_LIBADD} exists only as a per-target
>  variable.  @xref{Program and Library Variables}.
-Finally you should not think either that the existence of a per-target
-variable implies that of an @code{AM_} variable or that of a user
+Finally you should not think that the existence of a per-target
+variable implies the existance of an @code{AM_} variable or of a user
 variable.  For instance, the @code{mumble_LDADD} per-target variable
-overrides the global @code{LDADD} variable (which is not a user
+overrides the makefile-wide @code{LDADD} variable (which is not a user
 variable), and @code{mumble_LIBADD} exists only as a per-target
 variable.  @xref{Program and Library Variables}.