shared libraries linked into executable when they are not neccessary

[Tom Kacvinsky]

Hi Jose,

On Thu, Oct 23, 2025 at 10:56 AM Jose E. Marchesi <jose.marchesi@oracle.com>
wrote:

>
> What DSO is being linked that you don't expect?
>
> There are some DSOs that are linked in every non-static executable, such
> as ld-linux-x86-64.so, linux-vdso.so, and likely libc.so.6, libm etc.
>

These are not the usual glibc shared libraries.  These are boost
libraries that resolve
symbols from some of our static libraries.  But the thing is, I cannot
determine why
all of the boost libraries we specify on the link line are used, when we
really need
only two.

I'd attach my map file, but it's 15 MB.  That would be a no-no.

Tom


> > Hi,
> >
> > Not sure if this is the right list for asking this question.  If it's
> not,
> > please point me to the right list.
> >
> > I am confused as to why a shared library - which isn't needed by
> > an executable - is linked in.
> >
> > I am using binutils 2.39
> >
> > The link line contains
> >
> > -fuse-ld=gold -Wl,--as-needed -Wl,-Map,map.txt -Wl,--cref
> >
> > When I look at map.txt, I cannot find why the shared library is
> > necessary.  What should I look for?
> >
> > This is happening with binutils 2.45 as well.
> >
> > Thanks,
> >
> > Tom
>
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