Re: link statically with one library and dynamically with another?

[Bob Friesenhahn]

On Sun, 4 May 2008, Jack Bates wrote:

> How can I link statically with one library and dynamically with another?

In an environment you don't personally control, the only way to be 
absolutely sure is to provide the full path to the static library 
(e.g. /usr/local/lib/libfoo.a) rather than using -l syntax.  That is 
what libtool itself does under the covers when it intends to link 
statically.  The problem is that virtually all Unix linkers search for 
shared libraries first and scan the path a second time for static 
libraries.

Libtool itself provides these options:

  -all-static       do not do any dynamic linking at all
  -static           do not do any dynamic linking of uninstalled libtool 
libraries
  -static-libtool-libs
                    do not do any dynamic linking of libtool libraries

Platform/linker specific options can be passed direct to the linker 
using -Wl,option type syntax.  If you are luckly, libtool will 
preserve the original location of these options in the command line. 
Getting options out of order with what they apply to is a common 
libtool bug.

> - which did successfully link dynamically with libapr and statically
> with libtidy, but libtool warned me that referencing .libs/libtidy.a was
> not portable.

You should heed that warning.  If your libtidy is not built 
appropriately for use as a loadable module (e.g. PIC code on platforms 
which need it), the the linkage may fail.  Or the module loading will 
fail at run time.  The program which loads the module may simply core 
dump.

An option you should consider is to build libtidy as a convenience 
library which can then be safely "linked" with your module.  This 
approach likely requires that you create your own build environment 
for libtidy.

Bob
===
Bob Friesenhahn
address@hidden, http://www.simplesystems.org/users/bfriesen/
GraphicsMagick Maintainer,    http://www.GraphicsMagick.org/