Re: Cross-compiling hosted on Linux

[Delio Brignoli]

Hi,

Even though what you are trying to do is theoretically possible by  
wasting countless hours chasing up a version of gcc's source with  
apple patches and then making it work, breaking some licenses by  
installing their SDK libs on a different platform and then rewriting a  
number of utilities used by the build process I do not recommend you  
try.

Sadly, Apple does not support compiling for OSX on any platform other  
than... (drum roll) OSX.
Also Apple does not allow you to run their OS in a virtual machine. So  
I believe you will not be able to compile an executable targeted to  
OSX from your linux machine :(

Xcode is downloadable as an *huge* (a little more than 1GB) disk image  
from Apple. It is made up of an IDE, gcc, Apple's substitute for  
"make", SDK libraries for various versions of their OS and a thousands  
other development related utilities.

Xcode will be easy to use if all you need to do is build: open project  
file, hit build&run icon.

HTH (at least to avoid hours of fruitless attempts)
--
Delio

On 9/02/2008, at 4:06 PM, Aidan Gauland wrote:

If I was just trying to compile some command line program (like  
lynx), this would be a dawdle (probably).  But this program's build  
environment for Mac OS X uses Xcode, AND it makes a .app directory,  
for the Finder (if you don't know what the .... I'm talking  
about.....sorry, I just looked, and couldn't find anything  
explanatory on the net....it's just some weird way of organising  
files and folders in a directory named "foo.app", so it shows up to  
the Finder as a single file.  Lets not start an OS API flame war now  
though.)  So that complicates this problem a bit, and is what I need  
help with.

-Aidan

Volker Kuhlmann wrote:
On Fri 08 Feb 2008 19:12:24 NZDT +1300, A Thomas wrote:
Long version: I use Linux at home (duh), and the school I go to uses
Mac OS X (some Intel, some PPC), and I want to be able to use this
program at the school, but it would be a pain to compile it on the
school computers (mainly because I would have to puzzle out Xcode),
also if I need a new feature or bug fix in a new version, I would  
have
to go through this all again.  So if I could compile this program  
for
Mac, from Linux, that would save a lot of time.
What did your googling come up with? I put in "gcc macosx  
crosscompile
linux" and the top link to ubuntuforums is right on topic, but not  
all
that helpful - people who heard "gcc" and "cross-copile" in the same
sentence answering that gcc can do it, but otherwise not much clue to
the how (pretty much my experience with ubuntuforums in general - all
question, not much answer).
You're dealing with a complex issue and need to look at it one step  
at a
time. What gcc calls cross-compile is generating code for one  
processsor
on another one. Yes gcc can do that. You'll have to recompile gcc for
that as AFAIK no Linux distributor ships a gcc which is compiled for
more than the architecture it's running on. Keep in mind that gcc
compiles for processors only - it's what it calls hosts or
architectures, it does not really compile for operating systems. For
Apples you're looking at PPC and x86.
If you want to make the code actually run on another OS, you'll  
have to
get a linker which can all of a) create executable code for that
OS, b) link against the standard runtime environment of that OS, c)  
link
against any other libraries that the OS or your application uses. At
least b) needs substantial information about "macosx" on your Linux
machine - you guessed it, it's not there. You get to put it there  
first.
As pointed out by others, you'll need that xcode, it's unclear to me
whether it is available on Linux. Also, comments like "on mac osx  
we use
a specially doctored gcc made by apple" don't suggest to me that
develop-on-Linux-run-on-Macosx is that far advanced.
So this is what you need to sort out. If you make it, let us all know
and write it up somewhere. My guess is that only someone proficient  
in
developing on both Linux and Macosx independently will be able to put
something like this together, esp as all the parts might not yet be
available.
Volker