Re: LTLIBOBJS not built when using AC_REPLACE_FUNCS without AC_CONFIG_LIBOBJ_DIR

[Chris Pickett]

Hi Ralf,

Ralf Wildenhues wrote:
> 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?

Oops, I assumed src/strsignal.c was there because in your original 
example you wrote:

>
> autoreconf -vif  # will error out unless src/strsignal.c exists
>
> ./configure ac_cv_func_strsignal=no  # to fake nonexistent function
> make             # will build and link strsignal.lo

and because I attached it to my original message.  touch src/strsignal.c 
is suffficient.

> Now, let's assume you have src/strsignal.c.  Then automake will succeed.

Only with `libcheck_la_DEPENDENCIES =' alone, not if 
`libcheckinternal_la_DEPENDENCIES =' is there also.

> 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?

OS X:

$ ./configure ac_cv_func_strsignal=no
...
checking for strsignal... (cached) no
...
$ make
...
mv -f .deps/libcheck.Tpo .deps/libcheck.Plo
/bin/sh ../libtool --tag=CC   --mode=link gcc  -g -O2   -o libcheck.la 
-rpath /usr/local/lib libcheck.lo strsignal.lo
mv -f .deps/libcheckinternal.Tpo .deps/libcheckinternal.Plo
/bin/sh ../libtool --tag=CC   --mode=link gcc  -g -O2   -o 
libcheckinternal.la -rpath /usr/local/lib libcheckinternal.lo strsignal.lo
libtool: link: gcc -dynamiclib -Wl,-undefined -Wl,dynamic_lookup -o 
.libs/libcheckinternal.0.dylib  .libs/libcheckinternal.o 
.libs/strsignal.o      -install_name 
/usr/local/lib/libcheckinternal.0.dylib -compatibility_version 1 
-current_version 1.0 -Wl,-single_module
libtool: link: gcc -dynamiclib -Wl,-undefined -Wl,dynamic_lookup -o 
.libs/libcheck.0.dylib  .libs/libcheck.o .libs/strsignal.o 
-install_name  /usr/local/lib/libcheck.0.dylib -compatibility_version 1 
-current_version 1.0 -Wl,-single_module
...

MSYS/MinGW:

$ ./configure
...
checking for strsignal... no
...
$ make
...
mv -f .deps/libcheck.Tpo .deps/libcheck.Plo
/bin/sh ../libtool --tag=CC   --mode=link gcc  -g -O2   -o libcheck.la 
-rpath /usr/local/lib libcheck.lo strsignal.lo
libtool: link: `strsignal.lo' is not a valid libtool object
make[1]: *** [libcheck.la] Error 1
...

Was that the info you wanted?

> > 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?

The following horror:

EXPORT_SYM      = exported.sym
$(EXPORT_SYM): check.h.in
        sed -n -e 
's/^..*CK_EXPORT[[:space:]][[:space:]]*\([[:alnum:]_][[:alnum:]_]*\)..*$$/\1/p' 
@top_srcdir@/src/check.h.in > $@

libcheck_la_DEPENDENCIES= $(EXPORT_SYM)
libcheck_la_LDFLAGS     = -export-symbols $(EXPORT_SYM)
libcheck_la_SOURCES     = $(CFILES) $(HFILES)
libcheck_la_LIBADD      = @GCOV_LIBS@

libcheckinternal_la_SOURCES     = $(libcheck_la_SOURCES)
libcheckinternal_la_LIBADD      = @GCOV_LIBS@

At one point it did have @LTLIBOBJS@ in the _DEPENDENCIES line, but I 
switched to using the lib/ subdir and a libcompat (with an eye towards 
Gnulib).  Is there a better way to write this, besides commoning up 
@GCOV_LIBS@ in a single LIBADD = @GCOV_LIBS@ line?

> * 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.

Fair enough re: Linking the Program, but please consider 1.patch re: 
Program and Library Variables.  As it stands I believe that "only" 
$(LIBOBJS) and $(ALLOCA) being copied to _DEPENDENCIES is wrong.

> > 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.

Thanks, glad I could help.

Chris

diff --git a/doc/automake.texi b/doc/automake.texi
index ce4cbcc..9a13454 100644
--- a/doc/automake.texi
+++ b/doc/automake.texi
@@ -5517,11 +5517,13 @@ program are built, consider using the 
@code{BUILT_SOURCES} variable
 
 If @code{_DEPENDENCIES} is not supplied, it is computed by Automake.
 The automatically-assigned value is the contents of @code{_LDADD} or
address@hidden, with most configure substitutions, @option{-l}, @option{-L},
address@hidden and @option{-dlpreopen} options removed.  The configure
-substitutions that are left in are only @samp{$(LIBOBJS)} and
address@hidden(ALLOCA)}; these are left because it is known that they will not
-cause an invalid value for @code{_DEPENDENCIES} to be generated.
address@hidden, with most configure substitutions, @option{-l},
address@hidden, @option{-dlopen} and @option{-dlpreopen} options removed.
+The only configure substitutions that are left in are @samp{$(LIBOBJS)}
+and @samp{$(ALLOCA)} (for programs) and @samp{$(LTLIBOBJS)} and
address@hidden(LTALLOCA)} (for libraries); these are left because it is known
+that they will not cause an invalid value for @code{_DEPENDENCIES} to be
+generated.
 
 @code{_DEPENDENCIES} is more likely used to perform conditional
 compilation using an @code{AC_SUBST} variable that contains a list of