[fpc-pascal] cross compiling x64_64 to i386 linux

[Seth Grover]

I'm trying to cross-compile on Ubuntu 9.10 x86_64 for i386. Here's
what I've done so far:

I got FPC from the fixes_2_4 branch in SVN and did make/make install.

I used samplecfg to generate /etc/fpc/fpc.cfg.

I followed the wiki
(http://wiki.lazarus.freepascal.org/Cross_compiling#To_Linux) and did
the steps listed there, including creating the i386-linux-ld and
i386-linux-ls scripts in /usr/bin and compiling for the i386 target,
so I ended up with a ppc386.

 At this point I could do a simple "hello world" program which would
generate a 64-bit binary if i selected x86_64 for the target in
lazarus under "Compiler Options | Code" and a 32-bit binary if i
selected i386 as the target. So far so good.

I then tried to compile something a bit more complicated (not that
much more, though: I just tried to include "cthreads") and I got an
error about crti.so not being found:

/usr/bin/ld: skipping incompatible /usr/lib/crti.o when searching for
/usr/lib/crti.o
/usr/bin/ld: cannot find /usr/lib/crti.o
build.lpr(16,1) Error: Error while linking

As the Wiki is extremely vague as to what to do for fpc.cfg (Sorry,
but "Edit your /etc/fpc.cfg file if needed" is not very useful), I did
change this line:

#-Fl/lib;/usr/lib

to

-Fl/lib;/usr/lib;-Fl/lib32;/usr/lib32

However, to no avail. However, I did discover that /usr/lib32 doesn't
even have crti.o, so a little more investigation made me realize I
needed to install the "libc6-dev-i386" package, after which I did, in
fact, have that file.

However, I'm still unable to compile a 32-bit executable that includes
"cthreads" in its uses clause. ld still complains about not being able
to find crti.o, despite my having added /usr/lib32 to the -Fl line of
my fpc.cfg.

I do have this in my fpc.cfg:
==============================
# set binutils prefix

#IFNDEF CPUI386
#IFNDEF CPUAMD64
#DEFINE NEEDCROSSBINUTILS
#ENDIF
#ENDIF


#IFNDEF linux
#DEFINE NEEDCROSSBINUTILS
#ENDIF


#IFDEF FPC_CROSSCOMPILING
#IFDEF NEEDCROSSBINUTILS
  -XP$fpctarget-
#ENDIF NEEDCROSSBINUTILS
#ENDIF
==============================

but I don't know if that's correct or whatever, that's just what
samplecfg generated.

Observe:
compiling for 64-bit
==============================
$ /usr/local/bin/fpc  -MObjFPC -Scgi -O1 -gl -vewnhi -l -Fu. -obuild build.lpr
Hint: Start of reading config file /etc/fpc.cfg
Hint: End of reading config file /etc/fpc.cfg
Free Pascal Compiler version 2.3.1 [2009/11/02] for x86_64
Copyright (c) 1993-2009 by Florian Klaempfl
Target OS: Linux for x86-64
Compiling build.lpr
Linking build
ld here i am
ld.real: warning: link.res contains output sections; did you forget -T?
17 lines compiled, 0.2 sec
2 hint(s) issued
==============================

attempting to compile for 32-bit
==============================
$ /usr/local/bin/fpc -Pi386 -MObjFPC -Scgi -O1 -gl -vewnhi -l -Fu.
-obuild build.lpr
Hint: Start of reading config file /etc/fpc.cfg
Hint: End of reading config file /etc/fpc.cfg
Free Pascal Compiler version 2.3.1 [2009/11/02] for i386
Copyright (c) 1993-2009 by Florian Klaempfl
Target OS: Linux for i386
Compiling build.lpr
Linking build
ld: warning: link.res contains output sections; did you forget -T?
ld: skipping incompatible /usr/lib/crti.o when searching for /usr/lib/crti.o
ld: cannot find /usr/lib/crti.o
build.lpr(16,1) Error: Error while linking
build.lpr(16,1) Fatal: There were 1 errors compiling module, stopping
Fatal: Compilation aborted
Error: /usr/local/bin/ppc386 returned an error exitcode (normal if you
did not specify a source file to be compiled)
==============================

I sort of think that /usr/bin/i386-linux-ld isn't being called. I
added an "echo here I am" sort of line to that bash script, and I
never see that echo happen.

I'm sure there's some magic I need to do in my fpc.cfg file, but I'm
having a hard time finding specifically what it is. I'd really like to
be able to compile for x86_64 and i386 in the same development
environment simply by selecting a different target from the Lazarus UI
and have it "just work."

If anyone can offer assistance, I'd surely appreciate it.

-SG

--
This email is fiction. Any resemblance to actual events
or persons living or dead is purely coincidental.

Seth Grover
sethdgrover[at]gmail[dot]com