Re: Customizing soname

[Roumen Petrov]

Alon Bar-Lev wrote:
> On 3/28/08, Peter O'Gorman <address@hidden> wrote:
> > -rpath is required for proper execution in many environments, the
> >  ability to change the soname is, as far as I can tell, not.
> >
> >  Please present a more convincing argument.
>
> Hello Peter,
>
> I think that infrastructures such as libtool should allow customization
> of any attribute that affect the output. Of course there should be defaults
> but it should allow overriding to allow customization. This especially true
> when the customization is simple to implement and to maintain.
>
> Your example of not using automake simplified rules in order to
> workaround the lack of ability to customize the soname attribute
> is correct. But it is a workaround that makes build system much
> more complex, just because customization is missing.
>
> What you recommend is instead the following automake rules:
> lib_LTLIBRARIES=module1.la
> module1_la_SOURCES=m1.c m2.c m3.c m4.c
> module1_la_LDFLAGS=-module -avoid-version -soname "@MYNAME@"
>
> install-exec-local: install-libLTLIBRARIES
>         mv -f "$(DESTDIR)$(libdir)/module1.so" "$(DESTDIR)$(libdir)/@MYNAME@"
>
>
> Write the following make rules:
>
> LTCOMPILE = $(LIBTOOL) --tag=CC $(AM_LIBTOOLFLAGS) $(LIBTOOLFLAGS) \
>         --mode=compile $(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) \
>         $(AM_CPPFLAGS) $(CPPFLAGS) $(AM_CFLAGS) $(CFLAGS)
> CCLD = $(CC)
>
> my_objects=m1.lo m2.lo m3.lo m4.lo
> @MYNAME@: $(my_objects)
>         $(LIBTOOL) --tag=CC $(AM_LIBTOOLFLAGS) \
>                 $(LIBTOOLFLAGS) --mode=link $(CCLD) $(AM_CFLAGS) $(CFLAGS) \
>                 -module -avoid-version $(LDFLAGS) -o $@ \
>                 -rpath $(libdir) $(my_objects) $(LIBS)
>
> lib_LTLIBRARIES=#create
> install-exec-hook: install-libLTLIBRARIES @MYNAME@
>         $(LIBTOOL) --mode=install $(INSTALL) "@MYNAME@" \
>                 $(DESTDIR)$(libdir)
>
> all-local:      @MYNAME@
>
> .c.lo:
> if am__fastdepCC
>         $(LTCOMPILE) -MT $@ -MD -MP -MF $(DEPDIR)/$*.Tpo -c -o $@ $<
>         mv -f $(DEPDIR)/$*.Tpo $(DEPDIR)/$*.Plo
> else
> if AMDEP
>         source='$<' object='$@' libtool=yes @AMDEPBACKSLASH@
>         DEPDIR=$(DEPDIR) $(CCDEPMODE) $(depcomp) @AMDEPBACKSLASH@
> endif
>         $(LTCOMPILE) -c -o $@ $<
> endif

But you request is not what I expect from soname:

$echo "void foo(void) {}" > module.c
$ gcc -shared -o module.so -Wl,-soname=test.so module.c
$ objdump -x module.so  | grep SONAME
 SONAME      test.so
$ /sbin/ldconfig -v -l module.so
        test.so -> module.so

You request is to change library name. So I could not understand what is 
related to SONAME. It came as a surprise to me to allow user(verdor) to 
change library name at configure time.


Roumen