Re: Cocoa Newbie Question.

On Jun 11, 8:58=A0pm, Dave Seaman <dsea...@[EMAIL PROTECTED]
> wrote:
> On Wed, 11 Jun 2008 15:35:52 -0700 (PDT), piscesboy wrote:
> > I tried something different albeit much simpler. This might clear
> > things up. Here is the makefile I am using to compile this newer, much
> > simpler program of mine that mixes Objective-C and regular C code:
> > TARGET=3Dtest
> > DEBUG=3Ddebugtest
> > GCC=3Dgcc -ansi -pedantic -Wall -O2 -o
> > GCCOP=3Dgcc -ansi -pedantic -Wall -O2 -c
> > GCCMOP=3Dgcc -x objective-c -framework Foundation -c
> > OBJECTS=3Dmain.o Person.o treenode.o
> > SOURCE=3Dmain.m Person.m treenode.c
> > TRASH=3D*.o *.c~ *.h~ $(TARGET) $(DEBUG) Makefile~
> > $(TARGET): $(OBJECTS) $(SOURCE)
> > =A0 =A0$(GCC) $(TARGET) $(OBJECTS)
> > main.o: main.m defs.h
> > =A0 =A0$(GCCMOP) main.m
> > Person.o: Person.m Person.h
> > =A0 =A0$(GCCMOP) Person.m
> > treenode.o: treenode.c treenode.h
> > =A0 =A0$(GCCMOP) treenode.c
> > clean:
> > =A0 =A0rm -f $(TRASH)
> > My target is called test and depends on the objective-C files main.m,
> > and Person.m and the regular C file treenode.c
> > This is the error produced when I type 'make':
> > gcc -x objective-c -framework Foundation -c main.m
> > powerpc-apple-darwin8-gcc-4.0.1: -framework: linker input file unused
> > because linking not done
> > powerpc-apple-darwin8-gcc-4.0.1: Foundation: linker input file unused
> > because linking not done
> > gcc -x objective-c -framework Foundation -c Person.m
> > powerpc-apple-darwin8-gcc-4.0.1: -framework: linker input file unused
> > because linking not done
> > powerpc-apple-darwin8-gcc-4.0.1: Foundation: linker input file unused
> > because linking not done
> > gcc -x objective-c -framework Foundation -c treenode.c
> > powerpc-apple-darwin8-gcc-4.0.1: -framework: linker input file unused
> > because linking not done
> > powerpc-apple-darwin8-gcc-4.0.1: Foundation: linker input file unused
> > because linking not done
> > gcc -ansi -pedantic -Wall -O2 -o test main.o Person.o treenode.o
> > /usr/bin/ld: Undefined symbols:
> > .objc_class_name_NSConstantString
> > .objc_class_name_NSObject
> > .objc_class_name_NSString
> > __NSConstantStringClassReference
> > _objc_msgSend
> > _objc_msgSendSuper
> > collect2: ld returned 1 exit status
> > make: *** [test] Error 1
>
> You need "-framework Foundation" when you are linking, but not
otherwise.
> In fact, you did just the opposite, and this accounts for all the
warning
> messages and the undefined symbols error.
>
> The "-c" flag means "just compiile, don't link". =A0That's exactly what
yo=
u
> want to do on all the steps except the last one, but you are causing the
> compiler to point out repeatedly that it makes no sense to specify both
> "-c" and "-framework Foundation" on the same command line.
>
> > I think I know what is going on: that I am not linking the generated
> > object files properly. I do not know how to properly invoke the linker
> > to link the generated objective-c files mixed with C files.
>
> On the last step, where you are actually doing the linking, you left out
> "-framework Foundation". =A0This is the reason for the "Undefined
symbols"=

> error on the link step.
>
> By the way, "test" is a very poor choice for the name of an executable
> program. =A0Don't be surprised if executing the program appears to
produce=

> no response at all, since "test" is a shell builtin.

It is in fact a "test".  A dummy program that I built to learn about
Objective-C. It isn't meant to be proprietary software or a final
release at all. I have exactly 24 hours worth of Objective-C
experience as of this posting, so I am very much a novice at this
stuff.


>
> --
> Dave Seaman
> Third Circuit ignores precedent in Mumia Abu-Jamal ruling.
> <http://www.indybay.org/newsitems/2008/03/29/18489281.php>