bootstrap/3847: GCC 3.0 SEGVs while bootstrapping (-fexceptions only)

[chronos_tachyon at mail dot com]

>Number:         3847
>Category:       bootstrap
>Synopsis:       GCC 3.0 SEGVs while bootstrapping (-fexceptions only)
>Confidential:   no
>Severity:       critical
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          ice-on-legal-code
>Submitter-Id:   net
>Arrival-Date:   Fri Jul 27 12:26:01 PDT 2001
>Closed-Date:
>Last-Modified:
>Originator:     Chronos Tachyon
>Release:        3.0
>Organization:
n/a
>Environment:
System: Linux chronos 2.4.5 #1 Mon Jun 18 20:06:52 CDT 2001 i586 unknown
Architecture: i586
	Machine is a 300MHz AMD K6-2, with 512MB SDRAM
	Kernel is Linux 2.4.5
	Distribution is Slackware 7.0, heavily customized
	C Library is GLIBC 2.2.3
host: i386-pc-linux-gnu
build: i386-pc-linux-gnu
target: i386-pc-linux-gnu
configured with: ../gcc-3.0/configure --prefix=/usr/pkg/gcc-3.0 --host=i386-pc-linux --with-gnu-as --with-gnu-ld --enable-languages=c
>Description:
	I compiled a C-only, bootstrap version of GCC 3.0, then attempted to
	move on and produce a full version with all languages enabled.  The
	xgcc bootstrap compiler bombed out with a Segmentation fault.

	Details from "gcc -v":
		Specs: /usr/pkg/gcc-3.0/lib/gcc-lib/i386-pc-linux/3.0/specs
		Thread model: single
		gcc version 3.0
>How-To-Repeat:
	I attempted to build GCC 3.0 using the following configure command:

	export CFLAGS="-O2 -fomit-frame-pointer -march=486 -mcpu=pentium"
	../gcc-3.0/configure --prefix=/usr/pkg/gcc-3.0 --host=i386-pc-linux \
		--with-gnu-ld --with-gnu-as --enable-threads=posix

	However, about an hour into the build process, xgcc bombed out:

	[In directory: <build>/gcc]
	<build>/gcc/xgcc -B<build>/gcc/ \
		-B/usr/pkg/gcc-3.0/i386-pc-linux/bin/ \
		-B/usr/pkg/gcc-3.0/i386-pc-linux/lib/ \
		-isystem /usr/pkg/gcc-3.0/i386-pc-linux/include \
		-O2 -DIN_GCC -W -Wall -Wwrite-strings -Wstrict-prototypes \
		-Wmissing-prototypes -isystem ./include -fPIC -g1 \
		-DHAVE_GTHR_DEFAULT -DIN_LIBGCC2 -D__GCC_FLOAT_NOT_NEEDED \
		-I. -I. -I<source>/gcc -I<source>/gcc/. \
		-I<source>/gcc/config -I<source>/gcc/../include -fexceptions \
		-c <source>/gcc/unwind-dw2.c -o libgcc/./unwind-dw2.o
	[Snip four irrelevant warning messages]
	<source>/gcc/unwind-dw2.c: At top level:
	<source>/gcc/unwind-dw2.c:1123: Internal error: Segmentation fault
	Please submit a full bug report,
	with preprocessed source if appropriate.
	See <URL:http://www.gnu.org/software/gcc/bugs.html> for instructions.

	I tried trimming command line options until the file compiled
	successfully, and -fexceptions was determined to be the culprit.

	I suspected that the xgcc bootstrap compiler did not have exception
	support for some reason, then SEGV-ed when it encountered any files
	compiled with "-fexceptions". Replacing -fexceptions with
	-fno-exceptions in the proper Makefile fragment allowed unwind-dw2*.c
	to compile without incident, although I did not bother trying to
	progress further in this state.

	Clearing out the build directory and reconfiguring the compiler with
	the undocumented --enable-sjlj-exceptions flag improved the
	situation, but libstdc++ still bombed out without completing.  Here
	is the command where it fails:

	[In directory: <build>/i386-pc-linux/libstdc++-v3/libsupc++]
	<build>/gcc/xgcc -B<build>/gcc/ -nostdinc++ \
		-L<build>/i386-pc-linux/libstdc++-v3/src
		-L<build>/i386-pc-linux/libstdc++-v3/src/.libs
		-B/usr/pkg/gcc-3.0/i386-pc-linux/bin/ \
		-B/usr/pkg/gcc-3.0/i386-pc-linux/lib/ \
		-isystem /usr/pkg/gcc-3.0/i386-pc-linux/include \
		-I<source>/libstdc++-v3/../gcc \
		-I<source>/libstdc++-v3/../include \
		-I<source>/libstdc++-v3/include \
		-I<source>/libstdc++-v3/include/std \
		-I<source>/libstdc++-v3/include/c_std \
		-I../include -I<source>/libstdc++-v3/libsupc++ \
		-g -O2 -D_GNU_SOURCE -fno-implicit-templates -Wall \
		-Wno-format -W -Wwrite-strings -Winline \
		-fdiagnostics-show-location=once -ffunction-sections \
		-fdata-sections -g \
		-c <source>/libstdc++-v3/libsupc++/eh_personality.cc \
		-fPIC -DPIC -o eh_personality.o
	<source>/libstdc++-v3/libsupc++/eh_personality.cc: In function `void __cxa_call_unexpected(_Unwind_Exception*)':
	<source>/libstdc++-v3/libsupc++/eh_personality.cc:403: warning: new declaration `void __cxa_call_unexpected(_Unwind_Exception*)'
	<source>/libstdc++-v3/libsupc++/eh_personality.cc:403: warning: ambiguates built-in declaration `void __cxa_call_unexpected(void*)'
	<source>/libstdc++-v3/libsupc++/eh_personality.cc: In function `void __cxa_call_unexpected(_Unwind_Exception*)':
	<source>/libstdc++-v3/libsupc++/eh_personality.cc:443: Internal error: Segmentation fault
	Please submit a full bug report,
	with preprocessed source if appropriate.
	See <URL:http://www.gnu.org/software/gcc/bugs.html> for instructions.

>Fix:
	None that I am aware of.
>Release-Note:
>Audit-Trail:
>Unformatted: