Re: [swarm-hackers] A radical suggestion

[Marcus G. Daniels]

> Actually it fails in just the same way Swarm is failing!:

> The difference is I changed the Makefile:

> all: example
> %.o: %.m
>        gcc -fno-common -fgnu-runtime -c $< -o $@
> %.o: %.c
>        gcc -no-cpp-precomp -fno-common -c $< -o $@

The compiler has a different expectation of the runtime when you change 
to -fgnu-runtime.
Here is an example that makes the subdirectories "apple" and "gnu" with 
a pair of dynamic libraries "libobjc.dylib" and the executables 
"example".  You can see both are self-contained and runnable.  Now 
delete the "libobjc.dylib" in the "apple" subdirectory and re-run 
"example" and you'll see that you don't get the "local _objc_getClasses" 
implementation, but instead the system implementation.  In contrast, it 
doesn't work at all when you delete the libobjc.dylib in the "gnu" 
subdirectory because by default you won't have a shared library for the 
GNU runtime.  For clarity, in Makefile.common you'll see that even the 
GCC driver isn't used to link the final executable, just the linker. 
You can also see that libtool is run with -v and shows you what is 
being linked.  It's not inheriting things from the system libobjc. 
Don't be superstitious.

example.tar.gz
Description: GNU Zip compressed data