The following fixes the LTO part of the -f[no-]checking miscompare issue.
I introduce a compare-lto script similar to compare-debug where I strip
the LTO option section and re-compare. I have no easy way to test
the nonplugin path and at least for targets using simple-object to
wrap all LTO sections into one native sections we can't strip the
option section anyway so this just disables compare for those.
As a followup I'd like to add support to add extra files to compare
and for LTO bootstrap we'd like to compare cc1plus$(exeext) and
lto1$(exeext) - maybe I can come up with a pattern that works everywhere
but I guess this would be a start. But then for this we need PR85574
to be fixed first.
LTO bootstrapped on x86_64-unknown-linux-gnu.
OK for trunk?
Thanks,
Richard.
2018-05-02 Richard Biener <rguent...@suse.de>
PR bootstrap/85571
config/
* bootstrap-lto-noplugin.mk: Disable compare.
* bootstrap-lto.mk: Supply contrib/compare-lto for do-compare.
contrib/
* compare-lto: New script derived from compare-debug.
Index: config/bootstrap-lto-noplugin.mk
===================================================================
--- config/bootstrap-lto-noplugin.mk (revision 259829)
+++ config/bootstrap-lto-noplugin.mk (working copy)
@@ -6,3 +6,4 @@ STAGE3_CFLAGS += -flto=jobserver -frando
STAGEprofile_CFLAGS += -flto=jobserver -frandom-seed=1
STAGEtrain_CFLAGS += -flto=jobserver -frandom-seed=1
STAGEfeedback_CFLAGS += -flto=jobserver -frandom-seed=1
+do-compare = /bin/true
Index: config/bootstrap-lto.mk
===================================================================
--- config/bootstrap-lto.mk (revision 259829)
+++ config/bootstrap-lto.mk (working copy)
@@ -13,3 +13,5 @@ LTO_RANLIB = $$r/$(HOST_SUBDIR)/prev-gcc
LTO_EXPORTS = AR="$(LTO_AR)"; export AR; \
RANLIB="$(LTO_RANLIB)"; export RANLIB;
LTO_FLAGS_TO_PASS = AR="$(LTO_AR)" RANLIB="$(LTO_RANLIB)"
+
+do-compare = $(SHELL) $(srcdir)/contrib/compare-lto $$f1 $$f2
Index: contrib/compare-lto
===================================================================
--- contrib/compare-lto (nonexistent)
+++ contrib/compare-lto (working copy)
@@ -0,0 +1,111 @@
+#! /bin/sh
+
+# Compare copies of two given object files.
+
+# Copyright (C) 2007, 2008, 2009, 2010, 2012 Free Software Foundation
+# Originally by Alexandre Oliva <aol...@redhat.com>
+# Modified for LTO bootstrap by Richard Biener <rguent...@suse.de>
+
+# 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 3, or (at your option) any later
+# version.
+
+# 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 COPYING3. If not see
+# <http://www.gnu.org/licenses/>.
+
+rm='rm -f'
+
+case $1 in
+-p | --preserve)
+ rm='echo preserving'
+ shift
+ ;;
+esac
+
+if test $# != 2; then
+ echo 'usage: compare-lto file1.o file2.o' >&2
+ exit 1
+fi
+
+if test ! -f "$1"; then
+ echo "$1" does not exist >&2
+ exit 1
+fi
+
+if test ! -f "$2"; then
+ echo "$2" does not exist >&2
+ exit 1
+fi
+
+suf1=stripped
+while test -f "$1.$suf1"; do
+ suf1=$suf1.
+done
+
+suf2=stripped
+while test -f "$2.$suf2"; do
+ suf2=$suf2.
+done
+
+trap 'rm -f "$1.$suf1" "$2.$suf2"' 0 1 2 15
+
+if cmp "$1" "$2"; then
+ status=0
+else
+ status=1
+
+ cmd=
+ for t in objdump readelf eu-readelf; do
+ if ($t --help) 2>&1 | grep ' --\[*section-\]*headers' > /dev/null; then
+ cmd=$t
+ break
+ fi
+ done
+
+ # If there are LTO option sections, try to strip them off.
+ if test "x$cmd" = "x" ||
+ $cmd --section-headers "$1" | grep '.gnu.lto_.opts' > /dev/null ||
+ $cmd --section-headers "$2" | grep '.gnu.lto_.opts' > /dev/null ; then
+
+ echo stripping off LTO option section, then retrying >&2
+
+ seclist=".gnu.lto_.opts"
+ rsopts=`for sec in $seclist; do echo " --remove-section $sec"; done`
+
+ if (objcopy -v) 2>&1 | grep ' --remove-section' > /dev/null; then
+ objcopy $rsopts "$1" "$1.$suf1"
+ objcopy $rsopts "$2" "$2.$suf2"
+ elif (strip --help) 2>&1 | grep ' --remove-section' > /dev/null; then
+ cp "$1" "$1.$suf1"
+ strip $rsopts "$1.$suf1"
+
+ cp "$2" "$2.$suf2"
+ strip $rsopts "$2.$suf2"
+ else
+ echo failed to strip off LTO option section >&2
+ fi
+
+ trap 'rm -f "$1.$suf1" "$2.$suf2"' 0 1 2 15
+
+ if cmp "$1.$suf1" "$2.$suf2"; then
+ status=0
+ else
+ status=1
+ fi
+ fi
+fi
+
+$rm "$1.$suf1" "$2.$suf2"
+
+trap "exit $status; exit" 0 1 2 15
+
+exit $status
Property changes on: contrib/compare-lto
___________________________________________________________________
Added: svn:executable
## -0,0 +1 ##
+*
\ No newline at end of property
