From 1d4c9025e0eb16f7b447a8ebaa4e625c497c617d Mon Sep 17 00:00:00 2001
From: Brian Gaeke <gaeke@uiuc.edu>
Date: Wed, 3 Mar 2004 08:14:25 +0000
Subject: [PATCH] Add my regression finding by binary searching cvs script.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12095 91177308-0d34-0410-b5e6-96231b3b80d8
---
 utils/RegressionFinder.pl | 185 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 185 insertions(+)
 create mode 100755 utils/RegressionFinder.pl

diff --git a/utils/RegressionFinder.pl b/utils/RegressionFinder.pl
new file mode 100755
index 00000000000..94c8c736771
--- /dev/null
+++ b/utils/RegressionFinder.pl
@@ -0,0 +1,185 @@
+#! /usr/dcs/software/supported/bin/perl
+# Script to find regressions by binary-searching a time interval in the CVS tree. 
+# Written by Brian Gaeke on 2-Mar-2004
+#
+
+use Getopt::Std;
+use POSIX;
+use Time::Local;
+use IO::Handle;
+
+sub usage {
+    print STDERR <<END;
+findRegression [-I] -w WTIME -d DTIME -t TOOLS -c SCRIPT
+
+The -w, -d, -t, and -c options are required.
+Run findRegression in the top level of an LLVM tree.
+WTIME is a time when you are sure the regression does NOT exist ("Works").
+DTIME is a time when you are sure the regression DOES exist ("Doesntwork").
+WTIME and DTIME are both in the format: "YYYY/MM/DD HH:MM".
+-I means run builds at WTIME and DTIME first to make sure.
+TOOLS is a comma separated list of tools to rebuild before running SCRIPT.
+SCRIPT exits 1 if the regression is present in TOOLS; 0 otherwise.
+END
+    exit 1;
+}
+
+sub timeAsSeconds {
+    my ($timestr) = @_;
+
+    if ( $timestr =~ /(\d\d\d\d)\/(\d\d)\/(\d\d) (\d\d):(\d\d)/ ) {
+        my ( $year, $mon, $mday, $hour, $min ) = ( $1, $2, $3, $4, $5 );
+        return timegm( 0, $min, $hour, $mday, $mon - 1, $year );
+    }
+    else {
+        die "** Can't parse date + time: $timestr\n";
+    }
+}
+
+sub timeAsString {
+    my ($secs) = @_;
+    return strftime( "%Y/%m/%d %H:%M", gmtime($secs) );
+}
+
+sub run {
+    my ($cmdline) = @_;
+    print LOG "** Running: $cmdline\n";
+	return system($cmdline);
+}
+
+sub buildLibrariesAndTools {
+    run("sh /home/vadve/gaeke/scripts/run-configure");
+    run("$MAKE -C lib/Support");
+    run("$MAKE -C utils");
+    run("$MAKE -C lib");
+    foreach my $tool (@TOOLS) { run("$MAKE -C tools/$tool"); }
+}
+
+sub contains {
+    my ( $file, $regex ) = @_;
+    local (*FILE);
+    open( FILE, "<$file" ) or die "** can't read $file: $!\n";
+    while (<FILE>) {
+        if (/$regex/) {
+            close FILE;
+            return 1;
+        }
+    }
+    close FILE;
+    return 0;
+}
+
+sub updateSources {
+    my ($time) = @_;
+    my $inst = "include/llvm/Instruction.h";
+    unlink($inst);
+    run( "cvs update -D'" . timeAsString($time) . "'" );
+    if ( !contains( $inst, 'class Instruction.*Annotable' ) ) {
+        run("patch -F100 -p0 < makeInstructionAnnotable.patch");
+    }
+}
+
+sub regressionPresentAt {
+    my ($time) = @_;
+
+    updateSources($time);
+    buildLibrariesAndTools();
+    my $rc = run($SCRIPT);
+    if ($rc) {
+        print LOG "** Found that regression was PRESENT at "
+          . timeAsString($time) . "\n";
+        return 1;
+    }
+    else {
+        print LOG "** Found that regression was ABSENT at "
+          . timeAsString($time) . "\n";
+        return 0;
+    }
+}
+
+sub regressionAbsentAt {
+    my ($time) = @_;
+    return !regressionPresentAt($time);
+}
+
+sub closeTo {
+    my ( $time1, $time2 ) = @_;
+    return abs( $time1 - $time2 ) < 600;    # 10 minutes seems reasonable.
+}
+
+sub halfWayPoint {
+    my ( $time1, $time2 ) = @_;
+    my $halfSpan = int( abs( $time1 - $time2 ) / 2 );
+    if ( $time1 < $time2 ) {
+        return $time1 + $halfSpan;
+    }
+    else {
+        return $time2 + $halfSpan;
+    }
+}
+
+sub checkBoundaryConditions {
+    print LOG "** Checking for presence of regression at ", timeAsString($DTIME),
+      "\n";
+    if ( !regressionPresentAt($DTIME) ) {
+        die ( "** Can't help you; $SCRIPT says regression absent at dtime: "
+              . timeAsString($DTIME)
+              . "\n" );
+    }
+    print LOG "** Checking for absence of regression at ", timeAsString($WTIME),
+      "\n";
+    if ( !regressionAbsentAt($WTIME) ) {
+        die ( "** Can't help you; $SCRIPT says regression present at wtime: "
+              . timeAsString($WTIME)
+              . "\n" );
+    }
+}
+
+##############################################################################
+
+# Set up log files
+open (STDERR, ">&STDOUT") || die "** Can't redirect std.err: $!\n";
+autoflush STDOUT 1;
+autoflush STDERR 1;
+open (LOG, ">RegFinder.log") || die "** can't write RegFinder.log: $!\n";
+autoflush LOG 1;
+# Check command line arguments and environment variables
+getopts('Iw:d:t:c:');
+if ( !( $opt_w && $opt_d && $opt_t && $opt_c ) ) {
+    usage;
+}
+$MAKE  = $ENV{'MAKE'};
+$MAKE  = 'gmake' unless $MAKE;
+$WTIME = timeAsSeconds($opt_w);
+print LOG "** Assuming worked at ", timeAsString($WTIME), "\n";
+$DTIME = timeAsSeconds($opt_d);
+print LOG "** Assuming didn't work at ", timeAsString($DTIME), "\n";
+$opt_t =~ s/\s*//g;
+$SCRIPT = $opt_c;
+die "** $SCRIPT is not executable or not found\n" unless -x $SCRIPT;
+print LOG "** Checking for the regression using $SCRIPT\n";
+@TOOLS = split ( /,/, $opt_t );
+print LOG (
+    "** Going to rebuild: ",
+    ( join ", ", @TOOLS ),
+    " before each $SCRIPT run\n"
+);
+if ($opt_I) { checkBoundaryConditions(); }
+# do the dirty work:
+while ( !closeTo( $DTIME, $WTIME ) ) {
+    my $halfPt = halfWayPoint( $DTIME, $WTIME );
+    print LOG "** Checking whether regression is present at ",
+      timeAsString($halfPt), "\n";
+    if ( regressionPresentAt($halfPt) ) {
+        $DTIME = $halfPt;
+    }
+    else {
+        $WTIME = $halfPt;
+    }
+}
+# Tell them what we found
+print LOG "** Narrowed it down to:\n";
+print LOG "** Worked at: ",       timeAsString($WTIME), "\n";
+print LOG "** Did not work at: ", timeAsString($DTIME), "\n";
+close LOG;
+exit 0;
-- 
2.34.1