G++: GC-related ICE in CVS version

[Chip Salzenberg <chip at valinux dot com>]

When bootstrapping the current CVS sources (and back a few days), I
get a GC-related ICE when compiling libstdc++-v3:

----------------------------------------------------------------
/u/build/gcc/egcs/gcc/g++ -B/u/build/gcc/egcs/gcc/ -B/usr/local/egcs/i686-pc-linux-gnu/bin/ -DHAVE_CONFIG_H -I. -I../../../SRC/libstdc++-v3/src -I.. -nostdinc++ -I../../../SRC/libstdc++-v3 -I../../../SRC/libstdc++-v3/libio -I../../../SRC/libstdc++-v3/config/cpu/i386 -I../../../SRC/libstdc++-v3/config/gnu-linux -I/usr/local/egcs/include -pipe -g -O2 -fvtable-thunks -D_GNU_SOURCE -fno-implicit-templates -Wall -Wno-format -W -Wwrite-strings -Winline -Werror -g -fimplicit-templates -c  -fPIC -DPIC ../../../SRC/libstdc++-v3/src/misc-inst.cc -o .libs/misc-inst.lo
../../../SRC/libstdc++-v3/bits/basic_ios.h: In method `void std::basic_ios<_CharT, _Traits>::exceptions
../../../SRC/libstdc++-v3/bits/basic_ios.h: (std::_Ios_Iostate) [with _CharT = __wchar_t, _Traits =
../../../SRC/libstdc++-v3/bits/basic_ios.h: std::char_traits<__wchar_t>]':
../../../SRC/libstdc++-v3/src/misc-inst.cc:90:   instantiated from here
../../../SRC/libstdc++-v3/bits/basic_ios.h:139: Internal compiler error.
../../../SRC/libstdc++-v3/bits/basic_ios.h:139: Please submit a full bug report.
../../../SRC/libstdc++-v3/bits/basic_ios.h:139: See <URL:http://www.gnu.org/software/gcc/bugs.html> for
../../../SRC/libstdc++-v3/bits/basic_ios.h:139: instructions.
make[4]: *** [misc-inst.lo] Error 1
----------------------------------------------------------------

The debugger reveals a serious gc failure:

----------------------------------------------------------------
Program received signal SIGSEGV, Segmentation fault.
ggc_set_mark (p=0xd60) at ../SRC/gcc/ggc-page.c:748
748       bit = (((const char *) p) - entry->page) >> entry->order;
(gdb) print p
$1 = (void *) 0xd60
(gdb) print entry->page
Cannot access memory at address 0x8.
(gdb) print entry
$2 = (page_entry *) 0x0
(gdb) 
----------------------------------------------------------------

Here's my configuration:

SRC/configure --with-gcc-version-trigger=/u/build/gcc/egcs/SRC/gcc/version.c --host=i686-pc-linux-gnu --prefix=/usr/local/egcs --enable-languages=objc,c++ --enable-threads=posix --enable-shared --enable-version-specific-runtime-libs --enable-libstdcxx-v3 --enable-namespaces --enable-long-long --norecursion 

I'm using Debian's libgc5 binary, version 5.0.alpha4-8.  Under the
theory that libgc4 might not fail, I'll try that next.
-- 
Chip Salzenberg              - a.k.a. -              <chip@valinux.com>
"I wanted to play hopscotch with the impenetrable mystery of existence,
    but he stepped in a wormhole and had to go in early."  // MST3K