I’m crazy, so I’d really like to have Objective C as a target for Roundabout. If Perl is my first-implementation and reference language, I’d like to have ObjC as the “speed and power” language.

The first step to making this happen is making ObjC — or more correctly, Cocoa — code compile on Linux with GNUstep. It’s been a really long time since I found myself staring into the abyss of having absolutely no idea what an environment expects me to do to make it go, but that’s where I am with GNUstep.

My first step was to write an overly-correct hello.m that does things Apple ObjC2 style:

And then I tried to build it:

[mdxi@fornax test]$ clang -ObjC hello.m 
hello.m:1:9: fatal error: 'Foundation/Foundation.h' file not found
#import <Foundation/Foundation.h>

1 diagnostic generated.
[mdxi@fornax test]$ 

Okay, the GNUstep intro stressed how easy it was to do things because they used Makefiles to wrap up all the irritating bits of using frameworks. I found an example GNUmakefile and modified it a bit

include $(GNUSTEP_MAKEFILES)/common.make
 
TOOL_NAME = Hello
Hello_OBJC_FILES = hello.m
 
include $(GNUSTEP_MAKEFILES)/tool.make

Which got me this, instead:

[mdxi@fornax test]$ make
GNUmakefile:1: /common.make: No such file or directory
GNUmakefile:6: /tool.make: No such file or directory
make: *** No rule to make target `/tool.make'.  Stop.

Clearly ‘make’ didn’t magic those ENV vars into existance just because you’re compiling GNUstep stuff. You’re supposed to set them somewhere, somewhen, somehow.

Yep. There’s a setup bash script. On my system:

source /opt/GNUstep/System/Library/Makefiles/GNUstep.sh

Which yeilded:

[mdxi@fornax test]$ make
This is gnustep-make 2.4.0. Type 'make print-gnustep-make-help' for help.
Making all for tool Hello...
 Compiling file hello.m ...
gcc: error trying to exec 'cc1obj': execvp: No such file or directory
make[3]: *** [obj/Hello.obj/hello.m.o] Error 1
make[2]: *** [internal-tool-all_] Error 2
make[1]: *** [Hello.all.tool.variables] Error 2
make: *** [internal-all] Error 2

Well, yeah, I know that. I don’t want to use gcc-objc. I wanna use clang, because it is the new hotness. You do that like this:

make CC=clang

Which still doesn’t quite fix things:

[mdxi@fornax test]$ make CC=clang
This is gnustep-make 2.4.0. Type 'make print-gnustep-make-help' for help.
Making all for tool Hello...
 Compiling file hello.m ...
In file included from hello.m:1:
In file included from /opt/GNUstep/Local/Library/Headers/Foundation/Foundation.h:30:
In file included from /opt/GNUstep/Local/Library/Headers/GNUstepBase/GSVersionMacros.h:193:
In file included from /opt/GNUstep/Local/Library/Headers/GNUstepBase/GSConfig.h:225:
/opt/GNUstep/Local/Library/Headers/GNUstepBase/preface.h:81:11: fatal error: 'objc/objc.h' file
      not found
 #include <objc/objc.h>
          ^
1 diagnostic generated.

Sucks that it still isn’t working, but at least the error messages are a lot awesomer.