[johnMG]

I'm trying to build a simple shared library from a few source code files on OS X 10.3.5.

The relevant command line in my makefile looks like this:

g++ -Wall -Wl,-shared -Wl,-soname="libVecMath.so.1" Point.o Ray.o Triangle.o Vector.o -o libVecMath.so.1.0

but it's failing with this message:

ld: unknown flag: -shared
make: *** [libVecMath.so.1.0] Error 1

which is weird. Then I checked the man page for g++, and it says that Apple's gcc doesn't accept the -shared option. (?!)

Can anyone explain how or why Apple's gcc doesn't let me build a shared lib?

Thanks.

[larkost]

I am out on a limb here... but it probably has to do with MacOS X using dylib's rather than so's. Try a bit of googling a bit on that subject.

[Angus_D]

Try -dynamiclib (and you'll be wanting to use .1.0.dylib instead of .so.1). Oh, and you might like to use -install_name as well.

[johnMG]

Ah, there we go. Thanks Angus_D.

Well, I know that you can have both .so's and .dylib's on Mac OS X. However, that said, summing up, porting from GNU/Linux to OS X, to make a dylib, and a run-on sentence, it looks like I need to:

compile with: -fno-common (and *no* -fPIC),

and then link with: -dynamiclib -install_name (no -shared or -Wl,-soname), while naming my object file with a .dylib instead of .so.

Also, thanks again Angus_D for reminding me that on GNU/Linux you name the libs .so.n.m, whereas, on OS X, they're named .n.m.dylib (where n and m are major and minor version numbers, respectively).