regression/btest-gcc.sh: Support --add-passes-despite-regression

[Hans-Peter Nilsson <hans-peter dot nilsson at axis dot com>]

ISTR I've suggested this functionality before but it was turned
down as the default because it could cause spurious PASSes.  But
that's not a good enough reason: what statistically happens is
*not* that some regression somehow causes spurious PASSes, but
that a *single* long-standing regression stops
regression-checking of test-cases added later.  Not necessarily
good for a script that's supposed to test regressions...

Anyway, I made the suggested behavior optional.  Tested with and
without this option in IIRC all combinations (with/without new
fails, passes, with/without state being PASS).

Note that FAILs still aren't removed until "pass"; only new
tests that PASS are merged in.  I kept indentation style as per
surrounding code.

I'll also take the opportunity to ping the following patches to
btest-gcc.sh:
<URL:http://gcc.gnu.org/ml/gcc-patches/2005-04/msg00766.html>
Make libstdc++.sum optional
<URL:http://gcc.gnu.org/ml/gcc-patches/2005-04/msg01654.html>
Don't pass --with-newlib when target is "*-linux*".

In case the lack of review is due to a policy of never changing
or adding anything to this file, I guess the best action would
be to make a copy, so useful changes can be made.

Ok to commit?

	* btest-gcc.sh: Add support for option
	--add-passes-despite-regression.

Index: btest-gcc.sh
===================================================================
RCS file: /cvs/gcc/gcc/contrib/regression/btest-gcc.sh,v
retrieving revision 1.10
diff -p -u -r1.10 btest-gcc.sh
--- btest-gcc.sh	27 Oct 2004 18:19:41 -0000	1.10
+++ btest-gcc.sh	6 Jun 2005 03:02:16 -0000
@@ -1,7 +1,7 @@
 #!/bin/sh
 
 #  Test GCC.
-#  Copyright (C) 1999, 2000, 2001, 2002  Free Software Foundation, Inc.
+#  Copyright (C) 1999, 2000, 2001, 2002, 2005  Free Software Foundation, Inc.
 
 #  This program is free software; you can redistribute it and/or modify
 #  it under the terms of the GNU General Public License as published by
@@ -18,7 +18,20 @@
 #  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 
 # INPUT:
-# btest <target> <source> <prefix> <state> <build>
+# btest <options> <target> <source> <prefix> <state> <build>
+
+add_passes_despite_regression=0
+
+# <options> can be
+# --add-passes-despite-regression:
+#  Add new "PASSes" despite there being some regressions.
+
+case "$1" in
+ --add-passes-despite-regression)
+  add_passes_despite_regression=1; shift;;
+ --*) echo "Invalid option: $1"; exit 2;;
+esac
+
 # TARGET is the target triplet.  It should be the same one as used in
 # constructing PREFIX.  Or it can be the keyword 'native', indicating
 # a target of whatever platform the script is running on.
@@ -172,17 +191,34 @@ for LOG in $TESTLOGS ; do
 done | sort | uniq > $FAILED || exit 1
 comm -12 $FAILED $PASSES >> $REGRESS || exit 1
 NUMREGRESS=`wc -l < $REGRESS | tr -d ' '`
-if [ $NUMREGRESS -ne 0 ] ; then
+if [ $NUMREGRESS -ne 0 ] && [ $add_passes_despite_regression -eq 0 ] ; then
   echo regress-$NUMREGRESS > $RESULT
   exit 1
 fi
 
-# It passed.  Update the state.
+# Update the state.
 for LOG in $TESTLOGS ; do
   L=`basename $LOG`
   awk '/^PASS: / { print "'$L'",$2; }' $LOG || exit 1
 done | sort | uniq | comm -23 - $FAILED > ${PASSES}~ || exit 1
 [ -s ${PASSES}~ ] || exit 1
-mv ${PASSES}~ ${PASSES} || exit 1
+if [ $NUMREGRESS -ne 0 ] ; then
+  # While in regression, merge in previous PASSes, since there's a
+  # regressive difference we don't want to forget.  We don't do this
+  # when PASS (no or non-regressive difference), so we get rid of PASS
+  # lines for removed, moved or otherwise changed tests which may be
+  # added back with a different meaning later on.
+  cat ${PASSES}~ ${PASSES} | sort -u > ${PASSES}~~
+  mv ${PASSES}~~ ${PASSES} || exit 1
+  rm ${PASSES}~ || exit 1
+else
+  mv ${PASSES}~ ${PASSES} || exit 1
+fi
+
+if [ $NUMREGRESS -ne 0 ] ; then
+  echo regress-$NUMREGRESS > $RESULT
+  exit 1
+fi
+
 echo pass > $RESULT
 exit 0

brgds, H-P