f@3052: Upstream-Status: Backport
f@3052: Signed-off-by: Khem Raj <raj.khem@gmail.com>
f@3052: 
f@3052: From 95f5a9a866695da4e038aa4e6ccbbfd5d9cf63b7 Mon Sep 17 00:00:00 2001
f@3052: From: Joseph Myers <joseph@codesourcery.com>
f@3052: Date: Tue, 3 Jul 2012 19:14:59 +0000
f@3052: Subject: [PATCH] Avoid use of libgcc_s and libgcc_eh when building glibc.
f@3052: 
f@3052: ---
f@3052:  ChangeLog                  |   47 ++++++++++++++++++++++++++++++
f@3052:  Makeconfig                 |   68 ++++++++++++++++++++++++++++++++++++++------
f@3052:  Rules                      |   45 ++++++++++++++++++++++-------
f@3052:  elf/Makefile               |    6 +++-
f@3052:  elf/static-stubs.c         |   46 ++++++++++++++++++++++++++++++
f@3052:  ports/ChangeLog.arm        |    7 +++++
f@3052:  ports/sysdeps/arm/Makefile |    8 ++++++
f@3052:  7 files changed, 206 insertions(+), 21 deletions(-)
f@3052:  create mode 100644 elf/static-stubs.c
f@3052: 
f@3052: Index: a/libc/Makeconfig
f@3052: ===================================================================
f@3052: --- a/libc/Makeconfig	2012-07-04 18:26:22.000000000 -0700
f@3052: +++ b/libc/Makeconfig	2012-08-14 20:16:10.197093639 -0700
f@3052: @@ -415,9 +415,9 @@
f@3052:  LDFLAGS-rtld += $(hashstyle-LDFLAGS)
f@3052:  endif
f@3052:  
f@3052: -# Command for linking programs with the C library.
f@3052: +# Commands for linking programs with the C library.
f@3052:  ifndef +link
f@3052: -+link = $(CC) -nostdlib -nostartfiles -o $@ \
f@3052: ++link-before-libc = $(CC) -nostdlib -nostartfiles -o $@ \
f@3052:  	      $(sysdep-LDFLAGS) $(config-LDFLAGS) $(LDFLAGS) $(LDFLAGS-$(@F)) \
f@3052:  	      $(combreloc-LDFLAGS) $(relro-LDFLAGS) $(hashstyle-LDFLAGS) \
f@3052:  	      $(addprefix $(csu-objpfx),$(start-installed-name)) \
f@3052: @@ -426,7 +426,10 @@
f@3052:  						     $(start-installed-name))\
f@3052:  			   $(+preinit) $(link-extra-libs) \
f@3052:  			   $(common-objpfx)libc% $(+postinit),$^) \
f@3052: -	      $(link-extra-libs) $(link-libc) $(+postctor) $(+postinit)
f@3052: +	      $(link-extra-libs)
f@3052: ++link-after-libc = $(+postctor) $(+postinit)
f@3052: ++link = $(+link-before-libc) $(link-libc) $(+link-after-libc)
f@3052: ++link-tests = $(+link-before-libc) $(link-libc-tests) $(+link-after-libc)
f@3052:  endif
f@3052:  # Command for linking PIE programs with the C library.
f@3052:  ifndef +link-pie
f@3052: @@ -443,7 +446,7 @@
f@3052:  endif
f@3052:  # Command for statically linking programs with the C library.
f@3052:  ifndef +link-static
f@3052: -+link-static = $(CC) -nostdlib -nostartfiles -static -o $@ \
f@3052: ++link-static-before-libc = $(CC) -nostdlib -nostartfiles -static -o $@ \
f@3052:  	      $(sysdep-LDFLAGS) $(LDFLAGS) $(LDFLAGS-$(@F))  \
f@3052:  	      $(addprefix $(csu-objpfx),$(static-start-installed-name)) \
f@3052:  	      $(+preinit) $(+prector) \
f@3052: @@ -451,7 +454,12 @@
f@3052:  						     $(start-installed-name))\
f@3052:  			   $(+preinit) $(link-extra-libs-static) \
f@3052:  			   $(common-objpfx)libc% $(+postinit),$^) \
f@3052: -	      $(link-extra-libs-static) $(link-libc-static) $(+postctor) $(+postinit)
f@3052: +	      $(link-extra-libs-static) $(link-libc-static)
f@3052: ++link-static-after-libc = $(+postctor) $(+postinit)
f@3052: ++link-static = $(+link-static-before-libc) $(link-libc-static) \
f@3052: +	       $(+link-static-after-libc)
f@3052: ++link-static-tests = $(+link-static-before-libc) $(link-libc-static-tests) \
f@3052: +		     $(+link-static-after-libc)
f@3052:  endif
f@3052:  # Command for statically linking bounded-pointer programs with the C library.
f@3052:  ifndef +link-bounded
f@3052: @@ -475,10 +483,12 @@
f@3052:  # We need the versioned name of libc.so in the deps of $(others) et al
f@3052:  # so that the symlink to libc.so is created before anything tries to
f@3052:  # run the linked programs.
f@3052: -link-libc = -Wl,-rpath-link=$(rpath-link) \
f@3052: +link-libc-before-gnulib = -Wl,-rpath-link=$(rpath-link) \
f@3052:  	    $(common-objpfx)libc.so$(libc.so-version) \
f@3052:  	    $(common-objpfx)$(patsubst %,$(libtype.oS),c) \
f@3052: -	    $(as-needed) $(common-objpfx)elf/ld.so $(no-as-needed) $(gnulib)
f@3052: +	    $(as-needed) $(common-objpfx)elf/ld.so $(no-as-needed)
f@3052: +link-libc = $(link-libc-before-gnulib) $(gnulib)
f@3052: +link-libc-tests = $(link-libc-before-gnulib) $(gnulib-tests)
f@3052:  # This is how to find at build-time things that will be installed there.
f@3052:  rpath-dirs = math elf dlfcn nss nis rt resolv crypt
f@3052:  rpath-link = \
f@3052: @@ -488,6 +498,7 @@
f@3052:  nssobjdir := $(patsubst ../$(subdir),.,$(common-objpfx)nss)
f@3052:  resolvobjdir := $(patsubst ../$(subdir),.,$(common-objpfx)resolv)
f@3052:  link-libc = $(common-objpfx)libc.a $(otherlibs) $(gnulib) $(common-objpfx)libc.a $(gnulib)
f@3052: +link-libc-tests = $(common-objpfx)libc.a $(otherlibs) $(gnulib-tests) $(common-objpfx)libc.a $(gnulib-tests)
f@3052:  endif
f@3052:  endif
f@3052:  
f@3052: @@ -513,8 +524,43 @@
f@3052:  
f@3052:  # The static libraries.
f@3052:  link-libc-static = -Wl,--start-group $(common-objpfx)libc.a $(static-gnulib) -Wl,--end-group
f@3052: +link-libc-static-tests = -Wl,--start-group $(common-objpfx)libc.a $(static-gnulib-tests) -Wl,--end-group
f@3052:  link-libc-bounded = $(common-objpfx)libc_b.a $(gnulib) $(common-objpfx)libc_b.a
f@3052:  
f@3052: +# How to link against libgcc.  Some libgcc functions, such as those
f@3052: +# for "long long" arithmetic or software floating point, can always be
f@3052: +# built without use of C library headers and do not have any global
f@3052: +# state so can safely be linked statically into any executable or
f@3052: +# shared library requiring them; these functions are in libgcc.a.
f@3052: +# Other functions, relating to exception handling, may require C
f@3052: +# library headers to build and it may not be safe to have more than
f@3052: +# one copy of them in a process; these functions are only in
f@3052: +# libgcc_s.so and libgcc_eh.a.
f@3052: +#
f@3052: +# To avoid circular dependencies when bootstrapping, it is desirable
f@3052: +# to avoid use of libgcc_s and libgcc_eh in building glibc.  Where any
f@3052: +# glibc functionality (in particular, thread cancellation) requires
f@3052: +# exception handling, this is implemented through dlopen of libgcc_s
f@3052: +# to avoid unnecessary dependencies on libgcc_s by programs not using
f@3052: +# that functionality; executables built with glibc do not use
f@3052: +# exception handling other than through thread cancellation.
f@3052: +#
f@3052: +# Undefined references to functions from libgcc_eh or libgcc_s may
f@3052: +# arise for code built with -fexceptions.  In the case of statically
f@3052: +# linked programs installed by glibc, unwinding will never actually
f@3052: +# occur at runtime and the use of elf/static-stubs.c to resolve these
f@3052: +# references is safe.  In the case of statically linked test programs
f@3052: +# and test programs built with -fexceptions, unwinding may occur in
f@3052: +# some cases and it is preferable to link with libgcc_eh or libgcc_s
f@3052: +# so that the testing is as similar as possible to how programs will
f@3052: +# be built with the installed glibc.
f@3052: +#
f@3052: +# Some architectures have architecture-specific systems for exception
f@3052: +# handling that may involve undefined references to
f@3052: +# architecture-specific functions.  On those architectures,
f@3052: +# gnulib-arch and static-gnulib-arch may be defined in sysdeps
f@3052: +# makefiles to use additional libraries for linking executables and
f@3052: +# shared libraries built by glibc.
f@3052:  ifndef gnulib
f@3052:  ifneq ($(have-cc-with-libunwind),yes)
f@3052:    libunwind =
f@3052: @@ -522,8 +568,12 @@
f@3052:    libunwind = -lunwind
f@3052:  endif
f@3052:  libgcc_eh := -Wl,--as-needed -lgcc_s $(libunwind) -Wl,--no-as-needed
f@3052: -gnulib := -lgcc $(libgcc_eh)
f@3052: -static-gnulib := -lgcc -lgcc_eh $(libunwind)
f@3052: +gnulib-arch =
f@3052: +gnulib = -lgcc $(gnulib-arch)
f@3052: +gnulib-tests := -lgcc $(libgcc_eh)
f@3052: +static-gnulib-arch =
f@3052: +static-gnulib = -lgcc $(static-gnulib-arch)
f@3052: +static-gnulib-tests := -lgcc -lgcc_eh $(libunwind)
f@3052:  libc.so-gnulib := -lgcc
f@3052:  endif
f@3052:  +preinit = $(addprefix $(csu-objpfx),crti.o)
f@3052: Index: a/libc/Rules
f@3052: ===================================================================
f@3052: --- a/libc/Rules	2012-07-04 18:25:47.000000000 -0700
f@3052: +++ b/libc/Rules	2012-08-14 20:16:10.197093639 -0700
f@3052: @@ -1,5 +1,4 @@
f@3052: -# Copyright (C) 1991-2000,2002,2003,2004,2005,2006,2011
f@3052: -#	Free Software Foundation, Inc.
f@3052: +# Copyright (C) 1991-2012 Free Software Foundation, Inc.
f@3052:  # This file is part of the GNU C Library.
f@3052:  
f@3052:  # The GNU C Library is free software; you can redistribute it and/or
f@3052: @@ -103,29 +102,46 @@
f@3052:  # eglibc: endif
f@3052:  
f@3052:  ifeq ($(build-programs),yes)
f@3052: -binaries-all = $(others) $(sysdep-others) $(tests) $(xtests) $(test-srcs)
f@3052: -binaries-static = $(others-static) $(tests-static) $(xtests-static)
f@3052: +binaries-all-notests = $(others) $(sysdep-others)
f@3052: +binaries-all-tests = $(tests) $(xtests) $(test-srcs)
f@3052: +binaries-all = $(binaries-all-notests) $(binaries-all-tests)
f@3052: +binaries-static-notests = $(others-static)
f@3052: +binaries-static-tests = $(tests-static) $(xtests-static)
f@3052: +binaries-static = $(binaries-static-notests) $(binaries-static-tests)
f@3052:  ifeq (yesyes,$(have-fpie)$(build-shared))
f@3052:  binaries-pie = $(others-pie) $(tests-pie) $(xtests-pie)
f@3052:  else
f@3052:  binaries-pie =
f@3052:  endif
f@3052:  else
f@3052: -binaries-all = $(tests) $(xtests) $(test-srcs)
f@3052: +binaries-all-notests =
f@3052: +binaries-all-tests = $(tests) $(xtests) $(test-srcs)
f@3052: +binaries-all = $(binaries-all-tests)
f@3052: +binaries-static-notests =
f@3052: +binaries-static-tests =
f@3052:  binaries-static =
f@3052:  binaries-pie =
f@3052:  endif
f@3052:  
f@3052: -binaries-shared = $(filter-out $(binaries-pie) $(binaries-static), \
f@3052: -			       $(binaries-all))
f@3052: +binaries-shared-tests = $(filter-out $(binaries-pie) $(binaries-static), \
f@3052: +				     $(binaries-all-tests))
f@3052: +binaries-shared-notests = $(filter-out $(binaries-pie) $(binaries-static), \
f@3052: +				       $(binaries-all-notests))
f@3052:  
f@3052: -ifneq "$(strip $(binaries-shared))" ""
f@3052: -$(addprefix $(objpfx),$(binaries-shared)): %: %.o \
f@3052: +ifneq "$(strip $(binaries-shared-notests))" ""
f@3052: +$(addprefix $(objpfx),$(binaries-shared-notests)): %: %.o \
f@3052:    $(sort $(filter $(common-objpfx)lib%,$(link-libc))) \
f@3052:    $(addprefix $(csu-objpfx),start.o) $(+preinit) $(+postinit)
f@3052:  	$(+link)
f@3052:  endif
f@3052:  
f@3052: +ifneq "$(strip $(binaries-shared-tests))" ""
f@3052: +$(addprefix $(objpfx),$(binaries-shared-tests)): %: %.o \
f@3052: +  $(sort $(filter $(common-objpfx)lib%,$(link-libc))) \
f@3052: +  $(addprefix $(csu-objpfx),start.o) $(+preinit) $(+postinit)
f@3052: +	$(+link-tests)
f@3052: +endif
f@3052: +
f@3052:  ifneq "$(strip $(binaries-pie))" ""
f@3052:  $(addprefix $(objpfx),$(binaries-pie)): %: %.o \
f@3052:    $(sort $(filter $(common-objpfx)lib%,$(link-libc))) \
f@3052: @@ -133,13 +149,20 @@
f@3052:  	$(+link-pie)
f@3052:  endif
f@3052:  
f@3052: -ifneq "$(strip $(binaries-static))" ""
f@3052: -$(addprefix $(objpfx),$(binaries-static)): %: %.o \
f@3052: +ifneq "$(strip $(binaries-static-notests))" ""
f@3052: +$(addprefix $(objpfx),$(binaries-static-notests)): %: %.o \
f@3052:    $(sort $(filter $(common-objpfx)lib%,$(link-libc-static))) \
f@3052:    $(addprefix $(csu-objpfx),start.o) $(+preinit) $(+postinit)
f@3052:  	$(+link-static)
f@3052:  endif
f@3052:  
f@3052: +ifneq "$(strip $(binaries-static-tests))" ""
f@3052: +$(addprefix $(objpfx),$(binaries-static-tests)): %: %.o \
f@3052: +  $(sort $(filter $(common-objpfx)lib%,$(link-libc-static-tests))) \
f@3052: +  $(addprefix $(csu-objpfx),start.o) $(+preinit) $(+postinit)
f@3052: +	$(+link-static-tests)
f@3052: +endif
f@3052: +
f@3052:  ifeq ($(build-bounded),yes)
f@3052:  binaries-bounded = $(addsuffix -bp,$(tests) $(xtests) $(test-srcs))
f@3052:  $(addprefix $(objpfx),$(binaries-bounded)): %-bp: %.ob \
f@3052: Index: a/libc/elf/Makefile
f@3052: ===================================================================
f@3052: --- a/libc/elf/Makefile	2012-07-04 18:26:34.000000000 -0700
f@3052: +++ b/libc/elf/Makefile	2012-08-14 20:16:10.197093639 -0700
f@3052: @@ -71,6 +71,8 @@
f@3052:  install-bin	= sprof pldd
f@3052:  others-static   = sln
f@3052:  install-rootsbin = sln
f@3052: +sln-modules	:= static-stubs
f@3052: +extra-objs	+= $(sln-modules:=.o)
f@3052:  
f@3052:  ifeq (yes,$(use-ldconfig))
f@3052:  ifeq (yes,$(build-shared))
f@3052: @@ -78,7 +80,7 @@
f@3052:  others		+= ldconfig
f@3052:  install-rootsbin += ldconfig
f@3052:  
f@3052: -ldconfig-modules := cache readlib xmalloc xstrdup chroot_canon
f@3052: +ldconfig-modules := cache readlib xmalloc xstrdup chroot_canon static-stubs
f@3052:  extra-objs	+= $(ldconfig-modules:=.o)
f@3052:  endif
f@3052:  endif
f@3052: @@ -417,6 +419,8 @@
f@3052:  
f@3052:  $(objpfx)sprof: $(libdl)
f@3052:  
f@3052: +$(objpfx)sln: $(sln-modules:%=$(objpfx)%.o)
f@3052: +
f@3052:  $(objpfx)ldconfig: $(ldconfig-modules:%=$(objpfx)%.o)
f@3052:  
f@3052:  $(objpfx)pldd: $(pldd-modules:%=$(objpfx)%.o)
f@3052: Index: a/libc/elf/static-stubs.c
f@3052: ===================================================================
f@3052: --- /dev/null	1970-01-01 00:00:00.000000000 +0000
f@3052: +++ a/libc/elf/static-stubs.c	2012-08-14 20:16:10.197093639 -0700
f@3052: @@ -0,0 +1,46 @@
f@3052: +/* Stub implementations of functions to link into statically linked
f@3052: +   programs without needing libgcc_eh.
f@3052: +   Copyright (C) 2012 Free Software Foundation, Inc.
f@3052: +   This file is part of the GNU C Library.
f@3052: +
f@3052: +   The GNU C Library is free software; you can redistribute it and/or
f@3052: +   modify it under the terms of the GNU Lesser General Public
f@3052: +   License as published by the Free Software Foundation; either
f@3052: +   version 2.1 of the License, or (at your option) any later version.
f@3052: +
f@3052: +   The GNU C Library is distributed in the hope that it will be useful,
f@3052: +   but WITHOUT ANY WARRANTY; without even the implied warranty of
f@3052: +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
f@3052: +   Lesser General Public License for more details.
f@3052: +
f@3052: +   You should have received a copy of the GNU Lesser General Public
f@3052: +   License along with the GNU C Library; if not, see
f@3052: +   <http://www.gnu.org/licenses/>.  */
f@3052: +
f@3052: +/* Avoid backtrace (and so _Unwind_Backtrace) dependencies from
f@3052: +   sysdeps/unix/sysv/linux/libc_fatal.c.  */
f@3052: +#include <sysdeps/posix/libc_fatal.c>
f@3052: +
f@3052: +#include <stdlib.h>
f@3052: +#include <unwind.h>
f@3052: +
f@3052: +/* These programs do not use thread cancellation, so _Unwind_Resume
f@3052: +   and the personality routine are never actually called.  */
f@3052: +
f@3052: +void
f@3052: +_Unwind_Resume (struct _Unwind_Exception *exc __attribute__ ((unused)))
f@3052: +{
f@3052: +  abort ();
f@3052: +}
f@3052: +
f@3052: +_Unwind_Reason_Code
f@3052: +__gcc_personality_v0 (int version __attribute__ ((unused)),
f@3052: +		      _Unwind_Action actions __attribute__ ((unused)),
f@3052: +		      _Unwind_Exception_Class exception_class
f@3052: +		      __attribute__ ((unused)),
f@3052: +		      struct _Unwind_Exception *ue_header
f@3052: +		      __attribute__ ((unused)),
f@3052: +		      struct _Unwind_Context *context __attribute__ ((unused)))
f@3052: +{
f@3052: +  abort ();
f@3052: +}
f@3052: Index: a/ports/sysdeps/arm/Makefile
f@3052: ===================================================================
f@3052: --- a/ports/sysdeps/arm/Makefile	2012-07-04 18:25:41.000000000 -0700
f@3052: +++ b/ports/sysdeps/arm/Makefile	2012-08-14 20:16:10.201093638 -0700
f@3052: @@ -1,8 +1,16 @@
f@3052: +gnulib-arch = $(elfobjdir)/libgcc-stubs.a
f@3052: +static-gnulib-arch = $(elfobjdir)/libgcc-stubs.a
f@3052: +
f@3052:  ifeq ($(subdir),elf)
f@3052:  sysdep-dl-routines += tlsdesc dl-tlsdesc
f@3052:  sysdep_routines += aeabi_unwind_cpp_pr1 find_exidx tlsdesc dl-tlsdesc
f@3052:  sysdep-rtld-routines += aeabi_unwind_cpp_pr1 tlsdesc dl-tlsdesc
f@3052:  shared-only-routines += aeabi_unwind_cpp_pr1
f@3052: +
f@3052: +$(objpfx)libgcc-stubs.a: $(objpfx)aeabi_unwind_cpp_pr1.os
f@3052: +	$(build-extra-lib)
f@3052: +
f@3052: +lib-noranlib: $(objpfx)libgcc-stubs.a
f@3052:  endif
f@3052:  
f@3052:  ifeq ($(subdir),csu)