GCC Bugzilla Bug 12017

Building gcc mainline for avr target ICEs when building libobjc:

/home/dara/mainline/objdir/gcc/xgcc -B/home/dara/mainline/objdir/gcc/ -nostdinc -B/home/
dara/mainline/objdir/avr/newlib/ -isystem /home/dara/mainline/objdir/avr/newlib/targ-include 
-isystem /home/dara/mainline/combined/newlib/libc/include -B/tmp//avr/bin/ -B/tmp//avr/lib/ 
-isystem /tmp//avr/include -isystem /tmp//avr/sys-include -L/home/dara/mainline/objdir/ld -c 
-I. -I/home/dara/mainline/combined/libobjc -O2 -g -O2 -W -Wall -Wwrite-strings -Wstrict-
prototypes -DIN_GCC -DIN_TARGET_LIBS -I/home/dara/mainline/combined/libobjc/objc -I/
home/dara/mainline/combined/libobjc/../gcc -I/home/dara/mainline/combined/libobjc/../gcc/
config -I../../gcc -I/home/dara/mainline/combined/libobjc/../include /home/dara/mainline/
combined/libobjc/sendmsg.c -o sendmsg.o
/home/dara/mainline/combined/libobjc/sendmsg.c:42:1: warning: "rtx" redefined
In file included from /home/dara/mainline/combined/libobjc/sendmsg.c:31:
/home/dara/mainline/combined/libobjc/../gcc/coretypes.h:58:1: warning: this is the location of 
the previous definition
/home/dara/mainline/combined/libobjc/sendmsg.c: In function `__objc_word_forward':

/home/dara/mainline/combined/libobjc/sendmsg.c:581: error: unable to find a register to spill in 
class `BASE_POINTER_REGS'
/home/dara/mainline/combined/libobjc/sendmsg.c:581: error: this is the insn:
(insn 49 48 50 1 /home/dara/mainline/combined/libobjc/sendmsg.c:578 (set (reg:QI 30 r30 [+6 
])
        (mem:QI (plus:HI (reg/v/f:HI 18 r18 [orig:45 res ] [45])
                (const_int 6 [0x6])) [0 S1 A8])) 9 {*movqi} (nil)
    (nil))
/home/dara/mainline/combined/libobjc/sendmsg.c:581: internal compiler error: in spill_failure, at 
reload1.c:1862
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL:http://gcc.gnu.org/bugs.html> for instructions.
make: *** [sendmsg.lo] Error 1

Here's a testcase:

typedef const struct objc_selector
{
  void *sel_id;
  const char *sel_types;
} *SEL;

typedef struct objc_object {
  struct objc_class* class_pointer;
} *id;

static id
__objc_word_forward (id rcv, SEL op, ...)
{
  void *args, *res;

  args = __builtin_apply_args ();
  res = __objc_forward (rcv, op, args);
  __builtin_return (res);
}

This reproduces the ICE with a cross cc1. No optimization flags are necessary.

The only known languages that builds for the AVR are C and C++. There has been 
work on an Ada port for the AVR here: <http://sourceforge.net/projects/avr-
ada>, but it is incomplete. Any others (such as Objective C) on the AVR are 
unknown.

Newlib is not used as the C library for the AVR. You need to get avr-libc: 
<http://savannah.nongnu.org/projects/avr-libc>

The avr-libc user manual (found online above) also has instructions on building 
and installing a full toolchain. The AVR toolchain is maintained on Linux, 
FreeBSD, and Windows, and is known to build on Solaris and recently Mac OSX. 
For the Windows port see WinAVR: <http://sourceforge.net/projects/winavr>. For 
information on OSX see recent posts to the avr-gcc-list mailing list: 
<http://www.avr1.org/mailman/listinfo/avr-gcc-list/>

Eric

Confirmed on the mainline (20030930).

Suspending as there is no avr maintainer, yet.

There are 2 AVR maintainers.
From the MAINTAINERS file (3.3.1):
avr port		Denis Chertykov		denisc@overta.ru
avr port		Marek Michalkiewicz	marekm@linux.org.pl

Woops that was a different target I was think of.

Note this is C code not Objective-C code any way.

This problem is still present on mainline.

Denis, do you have any suggestions about what may be causing this issue? Thanks.

Subject: Re:  libobjc/sendmsg.c build ICE: in spill_failure, at reload1.c:1862

"dhazeghi at yahoo dot com" <gcc-bugzilla@gcc.gnu.org> writes:

It's because __builtin_return completely unsupported.

Denis.

Fair enough. Then would it be possible to disable building of objc (and
libobjc) on avr in configure, 
and document this as such? If this sounds good, I can make a patch...

Subject: Re:  libobjc/sendmsg.c build ICE: in spill_failure, at reload1.c:1862

"dhazeghi at yahoo dot com" <gcc-bugzilla@gcc.gnu.org> writes:

> PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.
> 
> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12017
> 
> 
> 
> ------- Additional Comments From dhazeghi at yahoo dot com  2003-10-27 21:38 -------
> Fair enough. Then would it be possible to disable building of objc (and libobjc) on avr in configure, 
> and document this as such? If this sounds good, I can make a
> patch...

Please make it !

Denis.

Note the Objective-C front-end just produces C front-end trees so the problem
is in avr 
back-end and needs to be fixed, this bug also is when using the C source code
and not 
Objective-C source.
So this really needs to be fixed and not patched by not building libobjc.

Seems to be fixed in 4.3 20070817 snapshot.

An additional minor patch is needed, not for this bug, but to allow Objective-C
to build for the AVR. (It's unknown if Objective-C will actually *work* on the
AVR...)

--- gcc/config/avr/avr.h.old    2007-08-23 15:18:31.015625000 -0600
+++ gcc/config/avr/avr.h        2007-08-23 15:19:17.687500000 -0600
@@ -53,7 +53,7 @@ extern int avr_mega_p;
 extern int avr_have_mul_p;
 extern int avr_asm_only_p;
 extern int avr_have_movw_lpmx_p;
-#ifndef IN_LIBGCC2
+#if !defined(IN_LIBGCC2) && !defined(IN_TARGET_LIBS)
 extern GTY(()) section *progmem_section;
 #endif

Seems to be fixed in 4.2.1, at least. I haven't tried earlier releases.
Changing target milestone and closing bug.