Re: LTLIBOBJS not built when using AC_REPLACE_FUNCS without AC_CONFIG_LIBOBJ_DIR

[Ralf Wildenhues]

Hello Chris,

thanks for the bug report and the analysis you have already done.

* Chris Pickett wrote on Sun, Dec 28, 2008 at 07:19:43AM CET:
>
> It turns out that I can fix my problem by adding @LTLIBOBJS@ to  
> libcheck_la_DEPENDENCIES, which is something I set explicitly but  
> neglected to mention earlier.
>
> Ralf Wildenhues wrote:
>> mkdir src
>> cat >configure.ac <<\END
>> AC_INIT(a,1)
>> AM_INIT_AUTOMAKE(foreign)
>> AC_CONFIG_FILES(Makefile src/Makefile)
>> AC_PROG_CC
>> AC_PROG_LIBTOOL
>> AC_REPLACE_FUNCS([strsignal])
>> AC_OUTPUT
>> END
>> echo 'SUBDIRS = src' > Makefile.am
>> cat >src/Makefile.am <<\END
>
> However, if you simply add
>
> libcheck_la_DEPENDENCIES =
>
> at this point (at the top of the src/Makefile.am) to your minimal  
> example, then strsignal.lo is produced under OS X, but not under  
> msys/gcc.

Wait a minute.  Even if I add
  libcheck_la_DEPENDENCIES =
  libcheckinternal_la_DEPENDENCIES =

then automake 1.10.2 still fails with
| src/Makefile.am:1: required file `src/strsignal.c' not found

Do you not see that happen?

Now, let's assume you have src/strsignal.c.  Then automake will succeed.
You say that things work OK under OS X but not with MSYS/MinGW.  Can you
please look what configure decides about strsignal there, and show the
failing 'make' output, best in a clean build tree?

> However, if you then take out the libcheckinternal bits it  
> fails (correctly) on OS X again.  It looks like libcheckinternal is  
> causing strsignal.lo to get built on OS X but not on sys/gcc.

Aside, why do you even need to touch the *_DEPENDENCIES variables at
all?

* Chris Pickett wrote on Sun, Dec 28, 2008 at 07:31:22AM CET:
>
>> In tracking this down, I found out that neither @LTLIBOBJS@ nor  
>> @LTALLOCA@ are mentioned in either the "Linking the Program" manual  
>> section or the "Program and Library Variables" section in the 
>> paragraphs talking about _DEPENDENCIES, although @LIBOBJS@ and @ALLOCA@ 
>> are.

Well, but that node deals with linking a program only, not linking a
library.  LTLIBOBJS and LTALLOCA are dealt with when Libtool libraries
are discussed, see
  info Automake "A Shared Libary"
and
  info Automake LTLIBOBJS

While I agree that it might not be obvious, I don't think the "Linking"
node should be filled with those details.  Also, the LIBOBJS node
already hints at LTLIBOBJS.

> Also, it's probably worth fixing this paragraph:
>
> `Using these variables is very similar to doing conditional
> compilation using `AC_SUBST' variables, as described in *note
> Conditional Sources::.  That is, when building a program, `$(LIBOBJS)'
> and `$(ALLOCA)' should be added to the associated `*_LDADD' variable,
> or to the `*_LIBADD' variable when building a library.  However there
> is no need to list the corresponding sources in `EXTRA_*_SOURCES' nor
> to define `*_DEPENDENCIES'.  Automake automatically adds `$(LIBOBJS)'
> and `$(ALLOCA)' to the dependencies, and it will discover the list of
> corresponding source files automatically (by tracing the invocations of
> the `AC_LIBSOURCE' Autoconf macros).'
>
> to replace the last `.' with `, unless you have already defined  
> *_DEPENDENCIES explicitly for another purpose, in which case you must  
> add these variables manually.'  This is consistent with the logic in the  
> previously mentioned sections about *_DEPENDENCIES.

Thanks, I am pushing this, slightly reworded change, both branches, and
adding you to THANKS.

Cheers,
Ralf

2008-12-29  Chris Pickett  <address@hidden>  (tiny change)

        * doc/automake.texi (LIBOBJS): Clarify overriding of
        `*_DEPENDENCIES'.
        * THANKS: Update.

diff --git a/doc/automake.texi b/doc/automake.texi
index 92b2a09..122a62a 100644
--- a/doc/automake.texi
+++ b/doc/automake.texi
@@ -5738,7 +5738,9 @@ However there is no need to list the corresponding 
sources in
 automatically adds @samp{$(LIBOBJS)} and @samp{$(ALLOCA)} to the
 dependencies, and it will discover the list of corresponding source
 files automatically (by tracing the invocations of the
address@hidden Autoconf macros).
address@hidden Autoconf macros).  However, if you have already
+defined @samp{*_DEPENDENCIES} explicitly for an unrelated reason, then
+you have to add these variables manually.
 
 These variables are usually used to build a portability library that
 is linked with all the programs of the project.  We now review a