[fpc-pascal] Re: cross compiling x64_64 to i386 linux

[Seth Grover]

Okay, in further investigation I am now manually forcing fpc to use
i386-linux-ld for linking by using the "-Pi386 -XPi386-linux-"
compiler flags (-P for the target and -XP for the binutils prefix). I
assume there's something wrong in my fpc.cfg or it would do this
manually, but I don't know what it is. Still, at least I'm getting
i386-linux-ld to be called.

However, ld is still not searching /usr/lib32. I also tried manually
adding -Fl/usr/lib32 to the fpc command line but that didn't help.

So apparently I have to somehow tell ld to look there...

-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



On Mon, Nov 2, 2009 at 12:45 PM, Seth Grover <sethdgrover at gmail.com> wrote:
> 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
>