Re: Mac OS X dynamic loading and Lua5.0.2

[Peter Colson <pcolson@...>]

On 22/03/2005, at 9:37 PM, Mike Pall wrote:

> Hi,
>
> PA wrote:
> > Mike Pall provided the following incantation to compile modules on Mac
> > OS X:
> >
> > local CompileCommand = "gcc -O2 -fno-common -c -o"
> > local LinkCommand = "gcc -bundle -undefined dynamic_lookup -o"
> >
> > Works like a charm.
>
> Yes, but on Lua 5.1 only!
>
> The original posting asked about Lua 5.0.2. But this one doesn't have 
> any
> support for Mac OS X. You need to patch it. Look into src/lib/loadlib.c
> at the bottom. However this patch requires you to compile your modules
> as dylibs (and not as bundles).

I'm quite happy to go to 5.1 since it offers better OS X support. I'm 
using Lua under OS X more as a quick test/prototype environ for another 
platform.

Tried making 5.1 (work5) and this line:

gcc -o lua  lua.o -L. -llua -llualib -lm -ldl -Wl,-E

fails with OS X ld not supporting the '-E' flag. Any hints as to what 
might work? I'll keep looking at this end, but I'm also learning the 
ropes with OS X build procedures as well.

> Peter Colson wrote:
> > So far I keep getting a Nil return from loadlib.
>
> The second return value should tell you what went wrong. Try:
>
> lua -e 'print(loadlib("xyz.so", "_luaopen_xyz"))'
>
> For Lua 5.0.2 "xyz.so" has to be in the current dir.

Tried this under 5.0.2 and it said 'loadlib not supported'. That makes  
sense. Then tried it on what I think was an old version of my test 
dylib using Lua5.1 libs that had been built without the ld '-E' param 
and it actually got into the luaopen_test (once I added '_' to the func 
name) before failing with a segmentation fault. Rebuilding my test 
module and linking to the new Lua5.1 libs produced heaps of undefined 
symbols which I think is due to removing '-E' and not adding the 
correct OS X options. Also had to re-ranlib the Lua5.1 libs according 
to another message that appeared.

> With Lua 5.1 you should use require("xyz") and put the module into the
> proper path ( /usr/local/lib/lua/5.1/xyz.so ).

Under OS X is the extension typically ',dylib' or '.so' or doesn't it 
really matter?


Regards,
Peter Colson.