re PR target/14925 (libunwind enabled gcc generates incompatible libgcc_s.so.1)

2004-09-03  H.J. Lu  <hongjiu.lu@intel.com>

	PR target/14925:
	Makefile.in (LIB2ADDEHSTATIC): New.
	(LIB2ADDEHSHARED): New.
	(LIBUNWIND): New.
	(LIBUNWINDDEP): New.
	(SHLIBUNWIND_LINK): New.
	(SHLIBUNWIND_INSTALL): New.
	(libgcc.mk): Pass LIB2ADDEHSTATIC, LIB2ADDEHSHARED, LIBUNWIND,
	LIBUNWINDDEP, SHLIBUNWIND_LINK and SHLIBUNWIND_INSTALL.
	(clean): Remove libunwind*
	(stage1-start): Remove and copy stage1/libunwind*.
	(stage2-start): Remove and copy stage2/libunwind*.
	(stage3-start): Remove and copy stage3/libunwind*.
	(stage4-start): Remove and copy stage4/libunwind*.
	(stageprofile-start): Remove and copy stageprofile/libunwind*.
	(stagefeedback-start): Remove and copy stagefeedback/libunwind*.

	* config.gcc (ia64*-*-linux*): Always add t-libunwind to
	tmake_file. Add t-libunwind-elf and ia64/t-glibc-libunwind to
	tmake_file if --with-system-libunwind isn't used.

	* config/ia64/t-glibc-libunwind: New file.
	* config/t-libunwind-elf: Likewise.
	* unwind-compat.c: Likewise.
	* unwind-compat.h: Likewise.
	* unwind-dw2-fde-compat.c: Likewise.

	* config/ia64/t-glibc (LIB2ADDEH): Updated.
	* config/ia64/t-hpux (T_CFLAGS): Add -DUSE_LIBUNWIND_EXCEPTIONS.

	* config/ia64/unwind-ia64.c: Include "unwind-compat.h". Define
	aliases if needed.
	* unwind-dw2-fde-glibc.c: Likewise.
	* unwind-dw2.c: Likewise.

	* config/t-libunwind (LIB2ADDEH): Updated.
	(LIB2ADDEHSTATIC): New.
	(T_CFLAGS): Add -DUSE_LIBUNWIND_EXCEPTIONS.
	(TARGET_LIBGCC2_CFLAGS): Set to -DUSE_GAS_SYMVER.

	* configure.ac: Change --enable-libunwind-exceptions to
	--with-system-libunwind. Don't define USE_LIBUNWIND_EXCEPTIONS.
	* configure: Regenerated.
	* config.in: Updated.

	* doc/install.texi (ia64-*-linux): Require libunwind 0.98 or
	above and mention --with-system-libunwind.
	(ia64-*-hpux*): Mention --enable-libunwind-exceptions is
	removed in gcc 3.4.3 and later.

	* gcc.c (init_spec): Add -lunwind to -lgcc_s if
	USE_LIBUNWIND_EXCEPTIONS is defined.

	* mklibgcc.in: Support libunwind.

From-SVN: r87066

gcc/ChangeLog

 2004-09-03  H.J. Lu  <hongjiu.lu@intel.com>
 
+	PR target/14925:
+	Makefile.in (LIB2ADDEHSTATIC): New.
+	(LIB2ADDEHSHARED): New.
+	(LIBUNWIND): New.
+	(LIBUNWINDDEP): New.
+	(SHLIBUNWIND_LINK): New.
+	(SHLIBUNWIND_INSTALL): New.
+	(libgcc.mk): Pass LIB2ADDEHSTATIC, LIB2ADDEHSHARED, LIBUNWIND,
+	LIBUNWINDDEP, SHLIBUNWIND_LINK and SHLIBUNWIND_INSTALL.
+	(clean): Remove libunwind*
+	(stage1-start): Remove and copy stage1/libunwind*.
+	(stage2-start): Remove and copy stage2/libunwind*.
+	(stage3-start): Remove and copy stage3/libunwind*.
+	(stage4-start): Remove and copy stage4/libunwind*.
+	(stageprofile-start): Remove and copy stageprofile/libunwind*.
+	(stagefeedback-start): Remove and copy stagefeedback/libunwind*.
+
+	* config.gcc (ia64*-*-linux*): Always add t-libunwind to
+	tmake_file. Add t-libunwind-elf and ia64/t-glibc-libunwind to
+	tmake_file if --with-system-libunwind isn't used.
+
+	* config/ia64/t-glibc-libunwind: New file.
+	* config/t-libunwind-elf: Likewise.
+	* unwind-compat.c: Likewise.
+	* unwind-compat.h: Likewise.
+	* unwind-dw2-fde-compat.c: Likewise.
+
+	* config/ia64/t-glibc (LIB2ADDEH): Updated.
+	* config/ia64/t-hpux (T_CFLAGS): Add -DUSE_LIBUNWIND_EXCEPTIONS.
+
+	* config/ia64/unwind-ia64.c: Include "unwind-compat.h". Define
+	aliases if needed.
+	* unwind-dw2-fde-glibc.c: Likewise.
+	* unwind-dw2.c: Likewise.
+
+	* config/t-libunwind (LIB2ADDEH): Updated.
+	(LIB2ADDEHSTATIC): New.
+	(T_CFLAGS): Add -DUSE_LIBUNWIND_EXCEPTIONS.
+	(TARGET_LIBGCC2_CFLAGS): Set to -DUSE_GAS_SYMVER.
+
+	* configure.ac: Change --enable-libunwind-exceptions to
+	--with-system-libunwind. Don't define USE_LIBUNWIND_EXCEPTIONS.
+	* configure: Regenerated.
+	* config.in: Updated.
+
+	* doc/install.texi (ia64-*-linux): Require libunwind 0.98 or
+	above and mention --with-system-libunwind.
+	(ia64-*-hpux*): Mention --enable-libunwind-exceptions is
+	removed in gcc 3.4.3 and later.
+
+	* gcc.c (init_spec): Add -lunwind to -lgcc_s if
+	USE_LIBUNWIND_EXCEPTIONS is defined.
+
+	* mklibgcc.in: Support libunwind.
+
+2004-09-03  H.J. Lu  <hongjiu.lu@intel.com>
+
 	* config/i386/i386.c (x86_branch_hints): Remove m_PENT4 and
 	m_NOCONA.
 

gcc/Makefile.in

@@ -532,8 +532,16 @@ CRTSTUFF_CFLAGS = -O2 $(GCC_CFLAGS) $(INCLUDES) $(MULTILIB_CFLAGS) -g0 \
 # Additional sources to handle exceptions; overridden by targets as needed.
 LIB2ADDEH = $(srcdir)/unwind-dw2.c $(srcdir)/unwind-dw2-fde.c \
    $(srcdir)/unwind-sjlj.c $(srcdir)/gthr-gnat.c $(srcdir)/unwind-c.c
+LIB2ADDEHSTATIC = $(LIB2ADDEH)
+LIB2ADDEHSHARED = $(LIB2ADDEH)
 LIB2ADDEHDEP = unwind.h unwind-pe.h unwind.inc unwind-dw2-fde.h unwind-dw2.h
 
+# Don't build libunwind by default.
+LIBUNWIND =
+LIBUNWINDDEP =
+SHLIBUNWIND_LINK =
+SHLIBUNWIND_INSTALL =
+
 # nm flags to list global symbols in libgcc object files.
 SHLIB_NM_FLAGS = -pg
 
@@ -1205,7 +1213,13 @@ libgcc.mk: config.status Makefile mklibgcc $(LIB2ADD) $(LIB2ADD_ST) xgcc$(exeext
 	LIB2ADD='$(LIB2ADD)' \
 	LIB2ADD_ST='$(LIB2ADD_ST)' \
 	LIB2ADDEH='$(LIB2ADDEH)' \
+	LIB2ADDEHSTATIC='$(LIB2ADDEHSTATIC)' \
+	LIB2ADDEHSHARED='$(LIB2ADDEHSHARED)' \
 	LIB2ADDEHDEP='$(LIB2ADDEHDEP)' \
+	LIBUNWIND='$(LIBUNWIND)' \
+	LIBUNWINDDEP='$(LIBUNWINDDEP)' \
+	SHLIBUNWIND_LINK='$(SHLIBUNWIND_LINK)' \
+	SHLIBUNWIND_INSTALL='$(SHLIBUNWIND_INSTALL)' \
 	FPBIT='$(FPBIT)' \
 	FPBIT_FUNCS='$(FPBIT_FUNCS)' \
 	LIB2_DIVMOD_FUNCS='$(LIB2_DIVMOD_FUNCS)' \
@@ -3051,6 +3065,7 @@ mostlyclean: lang.mostlyclean
 clean: mostlyclean lang.clean
 	-rm -f libgcc.a libgcc_eh.a libgcov.a
 	-rm -f libgcc_s$(SHLIB_EXT) libgcc_s$(SHLIB_EXT).1
+	-rm -f libunwind*
 	-rm -f config.h tconfig.h bconfig.h tm_p.h tm.h
 	-rm -f options.c options.h optionlist
 	-rm -f cs-*
@@ -3880,6 +3895,7 @@ stage1-start:
 	-if [ -f collect-ld$(exeext) ] ; then (cd stage1 && $(LN_S) ../collect-ld$(exeext) .) ; else true ; fi
 	-rm -f stage1/libgcc.a stage1/libgcc_eh.a stage1/libgcov.a
 	-rm -f stage1/libgcc_s*$(SHLIB_EXT)
+	-rm -f stage1/libunwind*
 	-cp libgcc.a stage1
 	-$(RANLIB_FOR_TARGET) stage1/libgcc.a
 	-cp libgcov.a stage1
@@ -3888,6 +3904,7 @@ stage1-start:
 	   $(RANLIB_FOR_TARGET) stage1/libgcc_eh.a; \
 	fi
 	-cp libgcc_s*$(SHLIB_EXT) stage1
+	-cp libunwind* stage1
 	-for f in .. $(EXTRA_MULTILIB_PARTS); do if [ x$${f} != x.. ]; then \
 	  cp stage1/$${f} . ; \
 	else true; \
@@ -3915,6 +3932,7 @@ stage2-start:
 	-if [ -f collect-ld$(exeext) ] ; then (cd stage2 && $(LN_S) ../collect-ld$(exeext) .) ; else true ; fi
 	-rm -f stage2/libgcc.a stage2/libgcov.a stage2/libgcc_eh.a
 	-rm -f stage2/libgcc_s*$(SHLIB_EXT)
+	-rm -f stage2/libunwind*
 	-cp libgcc.a stage2
 	-$(RANLIB_FOR_TARGET) stage2/libgcc.a
 	-cp libgcov.a stage2
@@ -3923,6 +3941,7 @@ stage2-start:
 	   $(RANLIB_FOR_TARGET) stage2/libgcc_eh.a; \
 	fi
 	-cp libgcc_s*$(SHLIB_EXT) stage2
+	-cp libunwind* stage2
 	-for f in .. $(EXTRA_MULTILIB_PARTS); do if [ x$${f} != x.. ]; then \
 	  cp stage2/$${f} . ; \
 	else true; \
@@ -3946,6 +3965,7 @@ stage3-start:
 	-if [ -f collect-ld$(exeext) ] ; then (cd stage3 && $(LN_S) ../collect-ld$(exeext) .) ; else true ; fi
 	-rm -f stage3/libgcc.a stage3/libgcov.a stage3/libgcc_eh.a
 	-rm -f stage3/libgcc_s*$(SHLIB_EXT)
+	-rm -f stage3/libunwind*
 	-cp libgcc.a stage3
 	-$(RANLIB_FOR_TARGET) stage3/libgcc.a
 	-cp libgcov.a stage3
@@ -3954,6 +3974,7 @@ stage3-start:
 	   $(RANLIB_FOR_TARGET) stage3/libgcc_eh.a; \
 	fi
 	-cp libgcc_s*$(SHLIB_EXT) stage3
+	-cp libunwind* stage3
 	-for f in .. $(EXTRA_MULTILIB_PARTS); do if [ x$${f} != x.. ]; then \
 	  cp stage3/$${f} . ; \
 	else true; \
@@ -3977,6 +3998,7 @@ stage4-start:
 	-if [ -f collect-ld$(exeext) ] ; then (cd stage4 && $(LN_S) ../collect-ld$(exeext) .) ; else true ; fi
 	-rm -f stage4/libgcc.a stage4/libgcov.a stage4/libgcc_eh.a
 	-rm -f stage4/libgcc_s*$(SHLIB_EXT)
+	-rm -f stage4/libunwind*
 	-cp libgcc.a stage4
 	-$(RANLIB_FOR_TARGET) stage4/libgcc.a
 	-cp libgcov.a stage4
@@ -3985,6 +4007,7 @@ stage4-start:
 	   $(RANLIB_FOR_TARGET) stage4/libgcc_eh.a; \
 	fi
 	-cp libgcc_s*$(SHLIB_EXT) stage4
+	-cp libunwind* stage4
 	-for f in .. $(EXTRA_MULTILIB_PARTS); do if [ x$${f} != x.. ]; then \
 	  cp stage4/$${f} . ; \
 	else true; \
@@ -4006,6 +4029,7 @@ stageprofile-start:
 	-if [ -f collect-ld$(exeext) ] ; then (cd stageprofile && $(LN_S) ../collect-ld$(exeext) .) ; else true ; fi
 	-rm -f stageprofile/libgcc.a stageprofile/libgcov.a stageprofile/libgcc_eh.a
 	-rm -f stageprofile/libgcc_s*$(SHLIB_EXT)
+	-rm -f stageprofile/libunwind*
 	-cp libgcc.a stageprofile
 	-$(RANLIB_FOR_TARGET) stageprofile/libgcc.a
 	-cp libgcov.a stageprofile
@@ -4014,6 +4038,7 @@ stageprofile-start:
 	   $(RANLIB_FOR_TARGET) stageprofile/libgcc_eh.a; \
 	fi
 	-cp libgcc_s*$(SHLIB_EXT) stageprofile
+	-cp libunwind* stageprofile
 	-for f in .. $(EXTRA_MULTILIB_PARTS); do if [ x$${f} != x.. ]; then \
 	  cp stageprofile/$${f} . ; \
 	else true; \
@@ -4035,6 +4060,7 @@ stagefeedback-start:
 	-if [ -f collect-ld$(exeext) ] ; then (cd stagefeedback && $(LN_S) ../collect-ld$(exeext) .) ; else true ; fi
 	-rm -f stagefeedback/libgcc.a stagefeedback/libgcov.a stagefeedback/libgcc_eh.a
 	-rm -f stagefeedback/libgcc_s*$(SHLIB_EXT)
+	-rm -f stagefeedback/libunwind*
 	-rm -f *.da
 	-for dir in fixinc po testsuite $(SUBDIRS); \
 	 do \
@@ -4048,6 +4074,7 @@ stagefeedback-start:
 	   $(RANLIB_FOR_TARGET) stagefeedback/libgcc_eh.a; \
 	fi
 	-cp libgcc_s*$(SHLIB_EXT) stagefeedback
+	-cp libunwind* stagefeedback
 	-for f in .. $(EXTRA_MULTILIB_PARTS); do if [ x$${f} != x.. ]; then \
 	  cp stagefeedback/$${f} . ; \
 	else true; \

gcc/config.gcc

@@ -1148,12 +1148,12 @@ ia64*-*-freebsd*)
 	;;
 ia64*-*-linux*)
 	tm_file="${tm_file} dbxelf.h elfos.h svr4.h linux.h ia64/sysv4.h ia64/linux.h"
-	tmake_file="${tmake_file} ia64/t-ia64 ia64/t-glibc"
+	tmake_file="${tmake_file} ia64/t-ia64 t-libunwind ia64/t-glibc"
+	if test x$with_system_libunwind != xyes ; then
+		tmake_file="${tmake_file} t-libunwind-elf ia64/t-glibc-libunwind"
+	fi
 	target_cpu_default="MASK_GNU_AS|MASK_GNU_LD"
 	extra_parts="crtbegin.o crtend.o crtbeginS.o crtendS.o crtfastmath.o"
-	if test x"$use_libunwind_exceptions" = xyes; then
-	  tmake_file="$tmake_file t-libunwind"
-	fi
 	;;
 ia64*-*-hpux*)
 	tm_file="${tm_file} dbxelf.h elfos.h svr4.h ia64/sysv4.h ia64/hpux.h"

gcc/config.in

@@ -573,9 +573,6 @@
 /* Define if your assembler mis-optimizes .eh_frame data. */
 #undef USE_AS_TRADITIONAL_FORMAT
 
-/* Define if gcc should use -lunwind. */
-#undef USE_LIBUNWIND_EXCEPTIONS
-
 /* Define to 1 if the 'long long' (or '__int64') is wider than 'long' but
    still efficiently supported by the host hardware. */
 #undef USE_LONG_LONG_FOR_WIDEST_FAST_INT

gcc/config/ia64/t-glibc

-LIB2ADDEH += $(srcdir)/config/ia64/fde-glibc.c
+# Use system libunwind library on IA-64 GLIBC based system.
+LIB2ADDEH = $(srcdir)/unwind-sjlj.c $(srcdir)/unwind-c.c \
+  $(srcdir)/unwind-compat.c

gcc/config/ia64/t-glibc-libunwind

+# Build libunwind for IA-64 GLIBC based system.
+LIBUNWIND = $(srcdir)/config/ia64/fde-glibc.c \
+  $(srcdir)/config/ia64/unwind-ia64.c
+LIBUNWINDDEP = unwind.inc

gcc/config/ia64/t-hpux

@@ -23,6 +23,8 @@ LIBGCC1_TEST =
 # We do not want to include the EH stuff that linux uses, we want to use
 # the HP-UX libunwind library.
 
+T_CFLAGS += -DUSE_LIBUNWIND_EXCEPTIONS
+
 LIB2ADDEH =
 
 SHLIB_EXT = .so

gcc/config/ia64/unwind-ia64.c

@@ -37,6 +37,7 @@
 #include "tm.h"
 #include "unwind.h"
 #include "unwind-ia64.h"
+#include "unwind-compat.h"
 #include "ia64intrin.h"
 
 /* This isn't thread safe, but nice for occasional tests.  */
@@ -2381,4 +2382,24 @@ uw_identify_context (struct _Unwind_Context *context)
 }
 
 #include "unwind.inc"
+
+#if defined (USE_GAS_SYMVER) && defined (SHARED) && defined (USE_LIBUNWIND_EXCEPTIONS)
+alias (_Unwind_Backtrace);
+alias (_Unwind_DeleteException);
+alias (_Unwind_FindEnclosingFunction);
+alias (_Unwind_FindTableEntry);
+alias (_Unwind_ForcedUnwind);
+alias (_Unwind_GetBSP);
+alias (_Unwind_GetCFA);
+alias (_Unwind_GetGR);
+alias (_Unwind_GetIP);
+alias (_Unwind_GetLanguageSpecificData);
+alias (_Unwind_GetRegionStart);
+alias (_Unwind_RaiseException);
+alias (_Unwind_Resume);
+alias (_Unwind_Resume_or_Rethrow);
+alias (_Unwind_SetGR);
+alias (_Unwind_SetIP);
+#endif
+
 #endif

gcc/config/t-libunwind

+# Use the system libunwind library.
+#
 # Override the default value from t-slibgcc-elf-ver and mention -lunwind
 # so that the resulting libgcc_s.so has the necessary DT_NEEDED entry for
 # libunwind.
 SHLIB_LC = -lunwind -lc
-LIB2ADDEH = $(srcdir)/unwind-sjlj.c $(srcdir)/unwind-c.c
+LIB2ADDEH = $(srcdir)/unwind-sjlj.c $(srcdir)/unwind-c.c \
+  $(srcdir)/unwind-compat.c $(srcdir)/unwind-dw2-fde-compat.c
+LIB2ADDEHSTATIC = $(srcdir)/unwind-sjlj.c $(srcdir)/unwind-c.c
+
+T_CFLAGS += -DUSE_LIBUNWIND_EXCEPTIONS
+TARGET_LIBGCC2_CFLAGS += -DUSE_GAS_SYMVER

gcc/config/t-libunwind-elf

+# Build libunwind for ELF with the GNU linker.
+
+# Use unwind-dw2-fde-glibc
+LIBUNWIND = $(srcdir)/unwind-dw2.c $(srcdir)/unwind-dw2-fde-glibc.c
+LIBUNWINDDEP = unwind.inc unwind-dw2-fde.h unwind-dw2-fde.c
+
+SHLIBUNWIND_SOVERSION = 7
+SHLIBUNWIND_SONAME = @shlib_so_name@.so.$(SHLIBUNWIND_SOVERSION)
+SHLIBUNWIND_NAME = @shlib_dir@@shlib_so_name@.so.$(SHLIBUNWIND_SOVERSION)
+
+SHLIBUNWIND_LINK = $(GCC_FOR_TARGET) $(LIBGCC2_CFLAGS) -shared \
+	-nodefaultlibs -Wl,-h,$(SHLIBUNWIND_SONAME) \
+	-Wl,-z,text -Wl,-z,defs \
+	-o $(SHLIBUNWIND_NAME) @multilib_flags@ $(SHLIB_OBJS) -lc && \
+	rm -f $(SHLIB_SOLINK) && \
+	$(LN_S) $(SHLIBUNWIND_NAME) $(SHLIB_SOLINK)
+
+# $(slibdir) double quoted to protect it from expansion while building
+# libgcc.mk.  We want this delayed until actual install time.
+SHLIBUNWIND_INSTALL = \
+	$$(SHELL) $$(srcdir)/mkinstalldirs $$(DESTDIR)$$(slibdir)$(SHLIB_SLIBDIR_QUAL); \
+	$(INSTALL_DATA) $(SHLIBUNWIND_NAME) \
+	  $$(DESTDIR)$$(slibdir)$(SHLIB_SLIBDIR_QUAL)/$(SHLIBUNWIND_SONAME); \
+	rm -f $$(DESTDIR)$$(slibdir)$(SHLIB_SLIBDIR_QUAL)/$(SHLIB_SOLINK); \
+	$(LN_S) $(SHLIBUNWIND_SONAME) \
+	  $$(DESTDIR)$$(slibdir)$(SHLIB_SLIBDIR_QUAL)/$(SHLIB_SOLINK)

gcc/configure.ac

@@ -1114,20 +1114,10 @@ AC_ARG_ENABLE(sjlj-exceptions,
 AC_DEFINE_UNQUOTED(CONFIG_SJLJ_EXCEPTIONS, $sjlj,
   [Define 0/1 to force the choice for exception handling model.])])
 
-if test x$host = x$target; then
-   AC_CHECK_LIB(unwind, main, use_libunwind_default=yes, use_libunwind_default=no)
-else
-   use_libunwind_default=no
-fi
-# Use libunwind based exception handling.
-AC_ARG_ENABLE(libunwind-exceptions,
-[  --enable-libunwind-exceptions  force use libunwind for exceptions],
-use_libunwind_exceptions=$enableval,
-use_libunwind_exceptions=$use_libunwind_default)
-if test x"$use_libunwind_exceptions" = xyes; then
-   AC_DEFINE(USE_LIBUNWIND_EXCEPTIONS, 1,
-	[Define if gcc should use -lunwind.])
-fi
+# For platforms with the unwind ABI which includes an unwind library,
+# libunwind, we can choose to use the system libunwind.
+AC_ARG_WITH(system-libunwind,
+[  --with-system-libunwind use installed libunwind])
 
 # --------------------------------------------------------
 # Build, host, and target specific configuration fragments

gcc/doc/install.texi

@@ -2933,8 +2933,9 @@ have installed.
 IA-64 processor (also known as IPF, or Itanium Processor Family)
 running GNU/Linux.
 
-If you are using the optional libunwind library, then you must use
-libunwind 0.96 or later.
+If you are using the installed system libunwind library with
+@option{--with-system-libunwind}, then you must use libunwind 0.98 or
+later.
 
 None of the following versions of GCC has an ABI that is compatible
 with any of the other versions in this list, with the exception that
@@ -2956,6 +2957,8 @@ the option @option{--with-gnu-as} may be necessary.
 The GCC libunwind library has not been ported to HPUX. This means that for
 GCC versions 3.2.3 and earlier, @option{--enable-libunwind-exceptions}
 is required to build GCC. For GCC 3.3 and later, this is the default.
+For gcc 3.4.3 and later, @option{--enable-libunwind-exceptions} is
+removed and the system libunwind library will always be used.
 
 @html
 <hr />

gcc/gcc.c

@@ -1703,6 +1703,9 @@ init_spec (void)
 #else
 			    "-lgcc_s%M"
 #endif
+#ifdef USE_LIBUNWIND_EXCEPTIONS
+			    " -lunwind"
+#endif
 			    ,
 			    "-lgcc",
 			    "-lgcc_eh"

gcc/unwind-compat.c

+/* Backward compatibility unwind routines.
+   Copyright (C) 2004
+   Free Software Foundation, Inc.
+
+   This file is part of GCC.
+
+   GCC is free software; you can redistribute it and/or modify it
+   under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   In addition to the permissions in the GNU General Public License, the
+   Free Software Foundation gives you unlimited permission to link the
+   compiled version of this file into combinations with other programs,
+   and to distribute those combinations without any restriction coming
+   from the use of this file.  (The General Public License restrictions
+   do apply in other respects; for example, they cover modification of
+   the file, and distribution when not linked into a combined
+   executable.)
+
+   GCC is distributed in the hope that it will be useful, but WITHOUT
+   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+   or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
+   License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with GCC; see the file COPYING.  If not, write to the Free
+   Software Foundation, 59 Temple Place - Suite 330, Boston, MA
+   02111-1307, USA.  */
+
+#if defined (USE_GAS_SYMVER) && defined (USE_LIBUNWIND_EXCEPTIONS)
+#include "unwind.h"
+#include "unwind-dw2-fde.h"
+#include "unwind-compat.h"
+
+extern _Unwind_Reason_Code __libunwind_Unwind_Backtrace
+  (_Unwind_Trace_Fn, void *);
+
+_Unwind_Reason_Code
+_Unwind_Backtrace (_Unwind_Trace_Fn trace, void *trace_argument)
+{
+  return __libunwind_Unwind_Backtrace (trace, trace_argument);
+}
+symver (_Unwind_Backtrace, GCC_3.3);
+
+extern void __libunwind_Unwind_DeleteException
+  (struct _Unwind_Exception *);
+
+void
+_Unwind_DeleteException (struct _Unwind_Exception *exc)
+{
+  return __libunwind_Unwind_DeleteException (exc);
+}
+symver (_Unwind_DeleteException, GCC_3.0);
+
+extern void * __libunwind_Unwind_FindEnclosingFunction (void *);
+
+void *
+_Unwind_FindEnclosingFunction (void *pc)
+{
+  return __libunwind_Unwind_FindEnclosingFunction (pc);
+}
+symver (_Unwind_FindEnclosingFunction, GCC_3.3);
+
+extern _Unwind_Reason_Code __libunwind_Unwind_ForcedUnwind
+  (struct _Unwind_Exception *, _Unwind_Stop_Fn, void *);
+
+_Unwind_Reason_Code
+_Unwind_ForcedUnwind (struct _Unwind_Exception *exc,
+		      _Unwind_Stop_Fn stop, void * stop_argument)
+{
+  return __libunwind_Unwind_ForcedUnwind (exc, stop, stop_argument);
+}
+symver (_Unwind_ForcedUnwind, GCC_3.0);
+
+extern _Unwind_Word __libunwind_Unwind_GetCFA
+  (struct _Unwind_Context *);
+
+_Unwind_Word
+_Unwind_GetCFA (struct _Unwind_Context *context)
+{
+  return __libunwind_Unwind_GetCFA (context);
+}
+symver (_Unwind_GetCFA, GCC_3.3);
+
+#ifdef __ia64__
+extern _Unwind_Word __libunwind_Unwind_GetBSP
+  (struct _Unwind_Context *);
+
+_Unwind_Word
+_Unwind_GetBSP (struct _Unwind_Context * context)
+{
+  return __libunwind_Unwind_GetBSP (context);
+}
+symver (_Unwind_GetBSP, GCC_3.3.2);
+#else
+extern _Unwind_Ptr __libunwind_Unwind_GetDataRelBase
+  (struct _Unwind_Context *);
+
+_Unwind_Ptr
+_Unwind_GetDataRelBase (struct _Unwind_Context *context)
+{
+  return __libunwind_Unwind_GetDataRelBase (context);
+}
+symver (_Unwind_GetDataRelBase, GCC_3.0);
+
+extern _Unwind_Ptr __libunwind_Unwind_GetTextRelBase
+  (struct _Unwind_Context *);
+
+_Unwind_Ptr
+_Unwind_GetTextRelBase (struct _Unwind_Context *context)
+{
+  return __libunwind_Unwind_GetTextRelBase (context);
+}
+symver (_Unwind_GetTextRelBase, GCC_3.0);
+#endif
+
+extern _Unwind_Word __libunwind_Unwind_GetGR
+  (struct _Unwind_Context *, int );
+
+_Unwind_Word
+_Unwind_GetGR (struct _Unwind_Context *context, int index)
+{
+  return __libunwind_Unwind_GetGR (context, index);
+}
+symver (_Unwind_GetGR, GCC_3.0);
+
+extern _Unwind_Ptr __libunwind_Unwind_GetIP (struct _Unwind_Context *);
+
+_Unwind_Ptr
+_Unwind_GetIP (struct _Unwind_Context *context)
+{
+  return __libunwind_Unwind_GetIP (context);
+}
+symver (_Unwind_GetIP, GCC_3.0);
+
+extern void *__libunwind_Unwind_GetLanguageSpecificData
+  (struct _Unwind_Context *);
+
+void *
+_Unwind_GetLanguageSpecificData (struct _Unwind_Context *context)
+{
+  return __libunwind_Unwind_GetLanguageSpecificData (context);
+}
+symver (_Unwind_GetLanguageSpecificData, GCC_3.0);
+
+extern _Unwind_Ptr __libunwind_Unwind_GetRegionStart
+  (struct _Unwind_Context *);
+
+_Unwind_Ptr
+_Unwind_GetRegionStart (struct _Unwind_Context *context)
+{
+  return __libunwind_Unwind_GetRegionStart (context);
+}
+symver (_Unwind_GetRegionStart, GCC_3.0);
+
+extern _Unwind_Reason_Code __libunwind_Unwind_RaiseException
+  (struct _Unwind_Exception *);
+
+_Unwind_Reason_Code
+_Unwind_RaiseException(struct _Unwind_Exception *exc)
+{
+  return __libunwind_Unwind_RaiseException (exc);
+}
+symver (_Unwind_RaiseException, GCC_3.0);
+
+extern void __libunwind_Unwind_Resume (struct _Unwind_Exception *);
+
+void
+_Unwind_Resume (struct _Unwind_Exception *exc)
+{
+  __libunwind_Unwind_Resume (exc);
+}
+symver (_Unwind_Resume, GCC_3.0);
+
+extern _Unwind_Reason_Code __libunwind_Unwind_Resume_or_Rethrow
+   (struct _Unwind_Exception *);
+
+_Unwind_Reason_Code
+_Unwind_Resume_or_Rethrow (struct _Unwind_Exception *exc)
+{
+  return __libunwind_Unwind_Resume_or_Rethrow (exc);
+}
+symver (_Unwind_Resume_or_Rethrow, GCC_3.3);
+
+extern void __libunwind_Unwind_SetGR
+  (struct _Unwind_Context *, int, _Unwind_Word);
+
+void
+_Unwind_SetGR (struct _Unwind_Context *context, int index,
+	       _Unwind_Word val) 
+{
+  __libunwind_Unwind_SetGR (context, index, val);
+}
+symver (_Unwind_SetGR, GCC_3.0);
+
+extern void __libunwind_Unwind_SetIP
+  (struct _Unwind_Context *, _Unwind_Ptr);
+
+void
+_Unwind_SetIP (struct _Unwind_Context *context, _Unwind_Ptr val)
+{
+  return __libunwind_Unwind_SetIP (context, val);
+}
+symver (_Unwind_SetIP, GCC_3.0);
+#endif

gcc/unwind-compat.h

+/* Backward compatibility unwind routines.
+   Copyright (C) 2004
+   Free Software Foundation, Inc.
+
+   This file is part of GCC.
+
+   GCC is free software; you can redistribute it and/or modify it
+   under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   In addition to the permissions in the GNU General Public License, the
+   Free Software Foundation gives you unlimited permission to link the
+   compiled version of this file into combinations with other programs,
+   and to distribute those combinations without any restriction coming
+   from the use of this file.  (The General Public License restrictions
+   do apply in other respects; for example, they cover modification of
+   the file, and distribution when not linked into a combined
+   executable.)
+
+   GCC is distributed in the hope that it will be useful, but WITHOUT
+   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+   or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
+   License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with GCC; see the file COPYING.  If not, write to the Free
+   Software Foundation, 59 Temple Place - Suite 330, Boston, MA
+   02111-1307, USA.  */
+
+#define symver(name, version) \
+  __asm__ (".symver " #name"," #name "@" #version)
+
+#define alias(name) \
+  __typeof(name) __libunwind##name __attribute__ ((alias (#name)))

gcc/unwind-dw2-fde-compat.c

+/* Backward compatibility unwind routines.
+   Copyright (C) 2004
+   Free Software Foundation, Inc.
+
+   This file is part of GCC.
+
+   GCC is free software; you can redistribute it and/or modify it
+   under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   In addition to the permissions in the GNU General Public License, the
+   Free Software Foundation gives you unlimited permission to link the
+   compiled version of this file into combinations with other programs,
+   and to distribute those combinations without any restriction coming
+   from the use of this file.  (The General Public License restrictions
+   do apply in other respects; for example, they cover modification of
+   the file, and distribution when not linked into a combined
+   executable.)
+
+   GCC is distributed in the hope that it will be useful, but WITHOUT
+   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+   or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
+   License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with GCC; see the file COPYING.  If not, write to the Free
+   Software Foundation, 59 Temple Place - Suite 330, Boston, MA
+   02111-1307, USA.  */
+
+#if defined (USE_GAS_SYMVER) && defined (USE_LIBUNWIND_EXCEPTIONS)
+#include "unwind.h"
+#include "unwind-dw2-fde.h"
+#include "unwind-compat.h"
+
+extern const fde * __libunwind__Unwind_Find_FDE
+  (void *, struct dwarf_eh_bases *);
+
+const fde *
+_Unwind_Find_FDE (void *pc, struct dwarf_eh_bases *bases)
+{
+  __libunwind__Unwind_Find_FDE (pc, bases);
+}
+
+symver (_Unwind_Find_FDE, GCC_3.0);
+#endif

gcc/unwind-dw2-fde-glibc.c

@@ -46,6 +46,7 @@
 #define NO_BASE_OF_ENCODED_VALUE
 #include "unwind-pe.h"
 #include "unwind-dw2-fde.h"
+#include "unwind-compat.h"
 #include "gthr.h"
 
 #if !defined(inhibit_libc) && defined(HAVE_LD_EH_FRAME_HDR) \
@@ -306,3 +307,7 @@ _Unwind_Find_FDE (void *pc, struct dwarf_eh_bases *bases)
 #define _Unwind_Find_FDE _Unwind_Find_FDE
 #include "unwind-dw2-fde.c"
 #endif
+
+#if defined (USE_GAS_SYMVER) && defined (SHARED) && defined (USE_LIBUNWIND_EXCEPTIONS)
+alias (_Unwind_Find_FDE);
+#endif

gcc/unwind-dw2.c

@@ -1317,4 +1317,24 @@ uw_identify_context (struct _Unwind_Context *context)
 
 #include "unwind.inc"
 
+#if defined (USE_GAS_SYMVER) && defined (SHARED) && defined (USE_LIBUNWIND_EXCEPTIONS)
+alias (_Unwind_Backtrace);
+alias (_Unwind_DeleteException);
+alias (_Unwind_FindEnclosingFunction);
+alias (_Unwind_FindTableEntry);
+alias (_Unwind_ForcedUnwind);
+alias (_Unwind_GetDataRelBase);
+alias (_Unwind_GetTextRelBase);
+alias (_Unwind_GetCFA);
+alias (_Unwind_GetGR);
+alias (_Unwind_GetIP);
+alias (_Unwind_GetLanguageSpecificData);
+alias (_Unwind_GetRegionStart);
+alias (_Unwind_RaiseException);
+alias (_Unwind_Resume);
+alias (_Unwind_Resume_or_Rethrow);
+alias (_Unwind_SetGR);
+alias (_Unwind_SetIP);
+#endif
+
 #endif /* !USING_SJLJ_EXCEPTIONS */