macOS Linker (ld) problems

I'm having a weird problem with the linker I cannot explain. Before filing it as a possible bug, I'd like to have your opinion on that.

Brief description:
I'm building an executable (command-line) that requires some external libraries.
Let's say I need to link (statically) with:
/usr/local/lib/libfoo.a
/usr/local/lib/libbar.a
/usr/local/lib/libfoo++.a
/usr/local/lib/libbar++.a

The external libraries (are given (to ld) by XCode using the form:
-lfoo -lbar -lfoo++ -lbar++

The problem: ld reports a bunch of unresolved symbols.

If I invoke by hand ld by specifying the static libs directly as input files instead of libraries everything works fine:
ld ... /usr/local/lib/libfoo.a /usr/locallib/libbar.a /usr/local/lib/libfoo++.a /usr/local/lib/libbar++.a

Interested?
If you want to reproduce it, download the xmlrpc-c library from Sourceforge
(xmlrpc-c.sourceforge.net), build it and install it under /usr/local and try to build one of the example first using the form that uses the -l<lib> flag, and then with the other form.

In my case I also discovered that ONLY ONE library needs to be listed using /usr/local/lib/<blah>.a...

To be more specific, this is *NOT* working:
ld <...> -lxmlrpc++ -lxmlrpc_server_abyss++ -lxmlrpc_server++ -lxmlrpc_server_abyss -lxmlrpc_server -lxmlrpc_abyss -lxmlrpc_util -lxmlrpc_xmlparse -lxmlrpc_xmltok -lxmlrpc

and this IS WORKING:
-lxmlrpc++ -lxmlrpc_server_abyss++ -lxmlrpc_server++ -lxmlrpc_server_abyss -lxmlrpc_server -lxmlrpc_abyss -lxmlrpc_util -lxmlrpc_xmlparse -lxmlrpc_xmltok /usr/local/lib/xmlrpc.a

Weird isn't it?
Am I missing something?
Is it really a bug ?

Thanks for your opinion.
Fab

lazydog said:

Hi

I may be totally wrong here but, but it looks you only need /usr/local/lib/xmlrpc.a for linking. The -lx is shorthand for /usr/local/lib/libx.a. So looking at the two examples, the first is linking to non existing libraries, while the second is linking to /usr/local/lib/xmlrpc.a.

b e n

EDIT: It just occurred to me that the 1st line doesn't work because it's trying to link to /usr/local/lib/libxmlrpc.a which doesn't exist, hence the reason why the 2nd line works.

Click to expand...

My bad... In my second example I was meant to put /usr/local/lib/libxmlrpc.a

Right now I have my Xcode project that list all the external library in the project, *BUT* the libxmlrpc.a is listed in the "Other linker flags"...

In conclusion it really seems to me the linker is really doing something wrong...

Fab

Well, I have not tried to re-use the same feature as I have found a workaround.
Instead of listing the libraries in the project, I'm adding (manually) all my dependencies to the linker command line, through the line "Other Linker Settings".
This solution not only fixes my problem, but it also allow me to specify different libraries for different configuration (Debug/Release).

Fab