[PD-dev] Using Shared libs in Externals

[Ben Bogart - FMPM/F1999]

Hello all,

I'm currently playing with the possibility of writing a SDL 
(www.libsdl.org) PD external. I've ported my code to the PD external 
format and can compile, but upon loading PD refuses to load the external 
because it can't find the SDL library functions (Undefined Symbol).


So how can I access the SDL library functions from my external lib? How 
can I link my lib to the sdl lib? 

cc: -lSDL: linker input file unused since linking not done
cc: -lm: linker input file unused since linking not done
cc: -lpthread: linker input file unused since linking not done

Here is my current Makefile: (based on the 6.externs example)

current:
        echo make pd_linux, pd_nt, pd_irix5, or pd_irix6

clean: ; rm -f *.pd_linux *.o

# ----------------------- LINUX i386 -----------------------
# Altered to compile SDL PD Externals

pd_linux: ben.pd_linux

.SUFFIXES: .pd_linux

CFLAGS = -DPD -O2 -funroll-loops -fomit-frame-pointer \
    -Wall -W -Wshadow -Wstrict-prototypes -Werror \
    -Wno-unused -Wno-parentheses -Wno-switch

INCLUDE =  -I../../src

LIBS = -lSDL -lm -lpthread 

.c.pd_linux:
        cc $(CFLAGS) $(LIBS) $(INCLUDE) -o $*.o -c $*.c
        ld -export_dynamic  -shared -o $*.pd_linux $*.o -lc -lm
        strip --strip-unneeded $*.pd_linux
        rm $*.o


I'm very new to C (been tinkering for only 2 weeks) so I'm still not 
quite clear on the whole linking/compiling process. 

Any pointers would be appriciated.

If seeing my (ugly) sourcecode would help I'd be happy to send it along.

Thanks
Ben




B. Bogart
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