-#!/usr/bin/perl
+#! /usr/bin/env perl
-# Copyright (c) 2001 Nathan L. Binkert
+# Copyright (c) 2003 The Regents of The University of Michigan
# All rights reserved.
#
-# Permission to redistribute, use, copy, and modify this software
-# without fee is hereby granted, provided that the following
-# conditions are met:
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met: redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer;
+# redistributions in binary form must reproduce the above copyright
+# notice, this list of conditions and the following disclaimer in the
+# documentation and/or other materials provided with the distribution;
+# neither the name of the copyright holders nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
#
-# 1. This entire notice is included in all source code copies of any
-# software which is or includes a copy or modification of this
-# software.
-# 2. The name of the author may not be used to endorse or promote
-# products derived from this software without specific prior
-# written permission.
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#
-# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
-# OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
-# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
-# ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
-# DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
-# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
-# GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
-# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
-# WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
-# NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
-# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-#
-
-use Algorithm::Diff qw(diff);
-use vars qw ($opt_C $opt_c $opt_u $opt_U);
-
-$opt_u = "";
-$opt_c = undef;
+# Authors: Nathan Binkert
+# Steve Reinhardt
-$diffsize = 2000;
-# After we've read up to a certain point in each file, the number of items
-# we've read from each file will differ by $FLD (could be 0)
-my $File_Length_Difference = 0;
-my $Context_Lines = 9;
-
-$progname = $0;
-if (scalar(@ARGV) != 2) {
- usage();
-}
+# Diff two streams.
+#
+# Unlike regular diff, this script does not read in the entire input
+# before doing a diff, so it can be used on lengthy outputs piped from
+# other programs (e.g., M5 traces). The best way to do this is to
+# take advantage of the power of Perl's open function, which will
+# automatically fork a subprocess if the last character in the
+# "filename" is a pipe (|). Thus to compare the instruction traces
+# from two versions of m5 (m5a and m5b), you can do this:
+#
+# rundiff 'm5a --traceflags=InstExec |' 'm5b --traceflags=InstExec |'
+#
-my ($filename1, $filename2);
-($filename1, $start1) = parse_filearg($ARGV[0]);
-($filename2, $start2) = parse_filearg($ARGV[1]);
+use strict;
+use FileHandle;
+use Getopt::Std;
-if ($filename1 eq "-" && $filename2 eq "-") {
- die "Only one of the inputs may be standard in\n";
-}
+#
+# Options:
+# -c <n> : print n lines of context before & after changes
+# -l <n> : use n lines of lookahead
+# -x : use "complex" diff from Algorithm::Diff (see below)
+#
+our ($opt_c, $opt_l, $opt_x);
+getopts('c:l:x');
-my ($file1, $file2);
-if ($filename1 eq "-") {
- $file1 = STDIN;
-} else {
- open(FILE1, $filename1) || die "can't open $file1: $!\n";
- $file1 = FILE1;
-}
+#
+# For the highest-quality (minimal) diffs, we can use the
+# Algorithm::Diff package. By default, a built-in, simple, and
+# generally quite adequate algorithm will be used. If you have
+# Algorithm::Diff installed on your system, and don't mind having the
+# script go slower (like 3-4x slower, based on informal observation),
+# then specify '-x' on the command line to use it.
+my $use_complexdiff = defined($opt_x);
+
+if ($use_complexdiff) {
+ # Don't use 'use', as that's a compile-time option and will fail
+ # on systems that don't have Algorithm::Diff installed even if
+ # $use_complexdiff is false. 'require' is evaluated at runtime,
+ # so it's OK.
+ require Algorithm::Diff;
+ import Algorithm::Diff qw(traverse_sequences);
+};
+
+my $lookahead_lines = $opt_l || 200;
+
+# in theory you could have different amounts of context before and
+# after a diff, but until someone needs that there's only one arg to
+# set both.
+my $precontext_lines = $opt_c || 3;
+my $postcontext_lines = $precontext_lines;
+
+my $file1 = $ARGV[0];
+my $file2 = $ARGV[1];
+
+die "Need two args." if (!(defined($file1) && defined($file2)));
+
+my ($fh1, $fh2);
+open($fh1, $file1) or die "Can't open $file1";
+open($fh2, $file2) or die "Can't open $file2";
+
+# print files to output so we know which is which
+print "-$file1\n";
+print "+$file2\n";
+
+# buffer of matching lines for pre-diff context
+my @precontext = ();
+# number of post-diff matching lines remaining to print
+my $postcontext = 0;
+
+# lookahead buffers for $file1 and $file2 respectively
+my @lines1 = ();
+my @lines2 = ();
+
+# Next line number available to print from each file. Generally this
+# corresponds to the oldest line in @precontext, or the oldest line in
+# @lines1 and @lines2 if @precontext is empty.
+my $lineno1 = 1;
+my $lineno2 = 1;
+
+# Fill a lookahead buffer to $lookahead_lines lines (or until EOF).
+sub fill
+{
+ my ($fh, $array) = @_;
-if ($filename2 eq "-") {
- $file2 = STDIN;
-} else {
- open(FILE2, $filename2) || die "can't open $file2: $!\n";
- $file2 = FILE2;
+ while (@$array < $lookahead_lines) {
+ my $line = <$fh>;
+ last if (!defined($line));
+ push @$array, $line;
+ }
}
-my $file_offset1 = ffw($file1, $start1);
-my $file_offset2 = ffw($file2, $start2);
-
-$skip_first = 0;
-my (@buf1, @buf2, @printbuf1, @printbuf2);
-
-$Compare_Ahead = 0;
-
-while (!eof($file1) && !eof($file2)) {
- my $line1 = <$file1>; chomp $line1;
- my $line2 = <$file2>; chomp $line2;
- my $printline1 = $line1;
- my $printline2 = $line2;
-
- push @buf1, $line1;
- push @buf2, $line2;
- push @printbuf1, $printline1;
- push @printbuf2, $printline2;
-
-# while ($Compare_Ahead < $Context_Lines) {
-# $line1 = @buf1[$Compare_Ahead];
-# $line2 = @buf2[$Compare_Ahead];
-# $line2 =~ s/ *--.*$//;
-# if ($line1 ne $line2) { last; }
-# ++$Compare_Ahead;
-# }
-
- $line1 = @buf1[$Compare_Ahead];
- $line2 = @buf2[$Compare_Ahead];
- $line2 =~ s/ *--.*$//;
-
- if ($line1 ne $line2) {
- while (!eof($file1) && scalar(@buf1) < $diffsize) {
- $line = <$file1>; chomp $line;
- my $printline = $line;
+# Print and delete n lines from front of given array with given prefix.
+sub printlines
+{
+ my ($array, $n, $prefix) = @_;
- push @printbuf1, $printline;
- push @buf1, $line;
- }
-
- while (!eof($file2) && scalar(@buf2) < $diffsize) {
- $line = <$file2>; chomp $line;
- my $printline = $line;
-# $line =~ s/ *--.*$//;
-
- push @printbuf2, $printline;
- push @buf2, $line;
+ while ($n--) {
+ my $line = shift @$array;
+ last if (!defined($line));
+ print $prefix, $line;
}
+}
- my $diffs = diff(\@buf1, \@buf2);
-
- next unless @$diffs;
-
- my @hunklist;
- my ($hunk,$oldhunk);
- # Loop over hunks. If a hunk overlaps with the last hunk, join them.
- # Otherwise, print out the old one.
- foreach my $piece (@$diffs) {
- $hunk = new Hunk ($piece, $Context_Lines, scalar(@buf1));
- next unless $oldhunk;
-
- if ($hunk->does_overlap($oldhunk)) {
- $hunk->prepend_hunk($oldhunk);
- } else {
- push @hunklist, $oldhunk;
- }
- } continue {
- $oldhunk = $hunk;
- }
-
- my $change = 0;
- while (scalar(@hunklist) && !$change) {
- $hunk = pop @hunklist;
- $change = $hunk->{"change"};
- }
- push @hunklist, $hunk;
- $last_start1 = $hunk->{"start1"};
- $last_start2 = $hunk->{"start2"};
- $last_end1 = $hunk->{"end1"};
- $last_end2 = $hunk->{"end2"};
-
- while (scalar(@hunklist)) {
- $hunk = shift @hunklist;
-# $hunk->output_diff(\@buf1, \@buf2);
- $hunk->output_diff(\@printbuf1, \@printbuf2);
+# Print a difference region where n1 lines of file1 were replaced by
+# n2 lines of file2 (where either n1 or n2 could be zero).
+sub printdiff
+{
+ my ($n1, $n2)= @_;
+
+ # If the precontext buffer is full or we're at the beginning of a
+ # file, then this is a new diff region, so we should print a
+ # header indicating the current line numbers. If we're past the
+ # beginning and the precontext buffer isn't full, then whatever
+ # we're about to print is contiguous with the end of the last
+ # region we printed, so we just concatenate them on the output.
+ if (@precontext == $precontext_lines || ($lineno1 == 0 && $lineno2 == 0)) {
+ print "@@ -$lineno1 +$lineno2 @@\n";
}
- $last_end1 -= $Context_Lines - 1;
- $last_end2 -= $Context_Lines - 1;
- $file_offset1 += $last_end1;
- $file_offset2 += $last_end2;
- @printbuf1 = @printbuf1[$last_end1..$#printbuf1];
- @printbuf2 = @printbuf2[$last_end2..$#printbuf2];
- @buf1 = @buf1[$last_end1..$#buf1];
- @buf2 = @buf2[$last_end2..$#buf2];
- while (scalar(@buf1) > $Context_Lines &&
- scalar(@buf2) > $Context_Lines) {
- $foo1 = @buf1[$Context_Lines];
- $foo2 = @buf2[$Context_Lines];
- if (scalar($foo1) != scalar($foo2) || $foo1 ne $foo2) { last; }
- $foo1 = shift @printbuf1;
- $foo2 = shift @printbuf2;
- $foo1 = shift @buf1;
- $foo2 = shift @buf2;
- ++$file_offset1;
- ++$file_offset2;
+ # Print and clear the precontext buffer.
+ if (@precontext) {
+ print ' ', join(' ', @precontext);
+ $lineno1 += scalar(@precontext);
+ $lineno2 += scalar(@precontext);
+ @precontext = ();
}
- } else {
- ++$file_offset1;
- ++$file_offset2;
- $foo1 = shift @printbuf1;
- $foo2 = shift @printbuf2;
- $foo1 = shift @buf1;
- $foo2 = shift @buf2;
- }
-}
-
-close $file1;
-close $file2;
-sub ffw() {
- if (scalar(@_) != 2) { die "improper usage of ffw\n"; }
+ # Print the differing lines.
+ printlines(\@lines1, $n1, '-');
+ printlines(\@lines2, $n2, '+');
+ $lineno1 += $n1;
+ $lineno2 += $n2;
- my $FILE = $_[0];
- my $start = $_[1];
- my $count = 0;
+ # Set $postcontext to print the next $postcontext_lines matching lines.
+ $postcontext = $postcontext_lines;
- while ($start-- > 0 && !eof($FILE)) {
- <$FILE>;
- $count++;
- }
-
- if ($start > 0) {die "File too short for ffw amount\n"; }
- return $count;
-}
-
-sub parse_filearg() {
- $start = 0;
- split /:/, @_[0];
- if (scalar(@_) > 2) { usage(); }
-
- $file = $_[0];
- if (scalar(@_) > 1) { $start = $_[1]; }
-
- return ($file, $start);
-}
-
-sub usage() {
- printf "usage: $progname <file1>[:start] <file2>[:start]\n";
- exit 1;
+ # Normally we flush after the postcontext lines are printed, but if
+ # the user has decreed that there aren't any we need to flush now
+ if ($postcontext == 0) {
+ STDOUT->flush();
+ }
}
-# Package Hunk. A Hunk is a group of Blocks which overlap because of the
-# context surrounding each block. (So if we're not using context, every
-# hunk will contain one block.)
-{
-package Hunk;
-
-sub new {
-# Arg1 is output from &LCS::diff (which corresponds to one Block)
-# Arg2 is the number of items (lines, e.g.,) of context around each block
-#
-# This subroutine changes $File_Length_Difference
+########################
#
-# Fields in a Hunk:
-# blocks - a list of Block objects
-# start - index in file 1 where first block of the hunk starts
-# end - index in file 1 where last block of the hunk ends
+# Complex diff algorithm
#
-# Variables:
-# before_diff - how much longer file 2 is than file 1 due to all hunks
-# until but NOT including this one
-# after_diff - difference due to all hunks including this one
- my ($class, $piece, $context_items, $maxlen) = @_;
-
- my $block = new Block ($piece); # this modifies $FLD!
-
- my $before_diff = $File_Length_Difference; # BEFORE this hunk
- my $after_diff = $before_diff + $block->{"length_diff"};
- $File_Length_Difference += $block->{"length_diff"};
-
- # @remove_array and @insert_array hold the items to insert and remove
- # Save the start & beginning of each array. If the array doesn't exist
- # though (e.g., we're only adding items in this block), then figure
- # out the line number based on the line number of the other file and
- # the current difference in file lenghts
- my @remove_array = $block->remove;
- my @insert_array = $block->insert;
- my ($a1, $a2, $b1, $b2, $start1, $start2, $end1, $end2, $change);
- $a1 = @remove_array ? $remove_array[0 ]->{"item_no"} : -1;
- $a2 = @remove_array ? $remove_array[-1]->{"item_no"} : -1;
- $b1 = @insert_array ? $insert_array[0 ]->{"item_no"} : -1;
- $b2 = @insert_array ? $insert_array[-1]->{"item_no"} : -1;
-
- $start1 = $a1 == -1 ? $b1 - $before_diff : $a1;
- $end1 = $a2 == -1 ? $b2 - $after_diff : $a2;
- $start2 = $b1 == -1 ? $a1 + $before_diff : $b1;
- $end2 = $b2 == -1 ? $a2 + $after_diff : $b2;
- $change = scalar(@remove_array) && scalar(@insert_array);
-
- # At first, a hunk will have just one Block in it
- my $hunk = {
- "start1" => $start1,
- "start2" => $start2,
- "end1" => $end1,
- "end2" => $end2,
- "maxlen" => $maxlen,
- "change" => $change,
- "blocks" => [$block],
- };
- bless $hunk, $class;
-
- $hunk->flag_context($context_items);
-
- return $hunk;
-}
+########################
-# Change the "start" and "end" fields to note that context should be added
-# to this hunk
-sub flag_context {
- my ($hunk, $context_items) = @_;
- return unless $context_items; # no context
-
- # add context before
- my $start1 = $hunk->{"start1"};
- my $num_added = $context_items > $start1 ? $start1 : $context_items;
- $hunk->{"start1"} -= $num_added;
- $hunk->{"start2"} -= $num_added;
-
- # context after
- my $end1 = $hunk->{"end1"};
- $num_added = ($end1+$context_items > $hunk->{"maxlen"}) ?
- $hunk->{"maxlen"} - $end1 :
- $context_items;
- $hunk->{"end1"} += $num_added;
- $hunk->{"end2"} += $num_added;
-}
+{
+ my $match_found;
+ my $discard_lines1;
+ my $discard_lines2;
+
+ sub match { $match_found = 1; }
+ sub discard1 { $discard_lines1++ unless $match_found; }
+ sub discard2 { $discard_lines2++ unless $match_found; }
+
+ sub complex_diff
+ {
+ $match_found = 0;
+ $discard_lines1 = 0;
+ $discard_lines2 = 0;
+
+ # See Diff.pm. Note that even though this call generates a
+ # complete diff of both lookahead buffers, all we use it for
+ # is to figure out how many lines to discard off the front of
+ # each buffer to resync the streams.
+ traverse_sequences( \@lines1, \@lines2,
+ { MATCH => \&match,
+ DISCARD_A => \&discard1,
+ DISCARD_B => \&discard2 });
+
+ if (!$match_found) {
+ printdiff(scalar(@lines1), scalar(@lines2));
+ die "Lost sync!";
+ }
-# Is there an overlap between hunk arg0 and old hunk arg1?
-# Note: if end of old hunk is one less than beginning of second, they overlap
-sub does_overlap {
- my ($hunk, $oldhunk) = @_;
- return "" unless $oldhunk; # first time through, $oldhunk is empty
+ # Since we shouldn't get here unless the first lines of the
+ # buffers are different, then we must discard some lines off
+ # at least one of the buffers.
+ die if ($discard_lines1 == 0 && $discard_lines2 == 0);
- # Do I actually need to test both?
- return ($hunk->{"start1"} - $oldhunk->{"end1"} <= 1 ||
- $hunk->{"start2"} - $oldhunk->{"end2"} <= 1);
+ printdiff($discard_lines1, $discard_lines2);
+ }
}
-# Prepend hunk arg1 to hunk arg0
-# Note that arg1 isn't updated! Only arg0 is.
-sub prepend_hunk {
- my ($hunk, $oldhunk) = @_;
-
- $hunk->{"start1"} = $oldhunk->{"start1"};
- $hunk->{"start2"} = $oldhunk->{"start2"};
-
- unshift (@{$hunk->{"blocks"}}, @{$oldhunk->{"blocks"}});
-}
+#######################
+#
+# Simple diff algorithm
+#
+#######################
+# Check for a pair of matching lines; if found, generate appropriate
+# diff output.
+sub checkmatch
+{
+ my ($n1, $n2) = @_;
+
+ # Check if two adjacent lines match, to reduce false resyncs
+ # (particularly on unrelated blank lines). This generates
+ # larger-than-necessary diffs when a single line really should be
+ # treated as common; if that bugs you, use Algorithm::Diff.
+ if ($lines1[$n1] eq $lines2[$n2] && $lines1[$n1+1] eq $lines2[$n2+1]) {
+ printdiff($n1, $n2);
+ return 1;
+ }
-# DIFF OUTPUT ROUTINES. THESE ROUTINES CONTAIN DIFF FORMATTING INFO...
-sub output_diff {
- if (defined $main::opt_u) {&output_unified_diff(@_)}
- elsif (defined $main::opt_c) {&output_context_diff(@_)}
- else {die "unknown diff"}
+ return 0;
}
-sub output_unified_diff {
- my ($hunk, $fileref1, $fileref2) = @_;
- my @blocklist;
-
- # Calculate item number range.
- my $range1 = $hunk->unified_range(1, $file_offset1);
- my $range2 = $hunk->unified_range(2, $file_offset2);
- print "@@ -$range1 +$range2 @@\n";
-
- # Outlist starts containing the hunk of file 1.
- # Removing an item just means putting a '-' in front of it.
- # Inserting an item requires getting it from file2 and splicing it in.
- # We splice in $num_added items. Remove blocks use $num_added because
- # splicing changed the length of outlist.
- # We remove $num_removed items. Insert blocks use $num_removed because
- # their item numbers---corresponding to positions in file *2*--- don't take
- # removed items into account.
- my $low = $hunk->{"start1"};
- my $hi = $hunk->{"end1"};
- my ($num_added, $num_removed) = (0,0);
- my @outlist = @$fileref1[$low..$hi];
- map {s/^/ /} @outlist; # assume it's just context
-
- foreach my $block (@{$hunk->{"blocks"}}) {
- foreach my $item ($block->remove) {
- my $op = $item->{"sign"}; # -
- my $offset = $item->{"item_no"} - $low + $num_added;
- $outlist[$offset] =~ s/^ /$op/;
- $num_removed++;
- }
- foreach my $item ($block->insert) {
- my $op = $item->{"sign"}; # +
- my $i = $item->{"item_no"};
- my $offset = $i - $hunk->{"start2"} + $num_removed;
- splice(@outlist,$offset,0,"$op$$fileref2[$i]");
- $num_added++;
+sub simple_diff
+{
+ # Look for differences of $cnt lines to resync,
+ # increasing $cnt from 1 to $lookahead_lines until we find
+ # something.
+ for (my $cnt = 1; $cnt < $lookahead_lines-1; ++$cnt) {
+ # Check for n lines in one file being replaced by
+ # n lines in the other.
+ return if checkmatch($cnt, $cnt);
+ # Find differences where n lines in one file were
+ # replaced by m lines in the other. We let m = $cnt
+ # and iterate for n = 0 to $cnt-1.
+ for (my $n = 0; $n < $cnt; ++$n) {
+ return if checkmatch($n, $cnt);
+ return if checkmatch($cnt, $n);
}
}
- map {s/$/\n/} @outlist; # add \n's
- print @outlist;
-
+ printdiff(scalar(@lines1), scalar(@lines2));
+ die "Lost sync!";
}
-sub output_context_diff {
- my ($hunk, $fileref1, $fileref2) = @_;
- my @blocklist;
-
- print "***************\n";
- # Calculate item number range.
- my $range1 = $hunk->context_range(1, $file_offset1);
- my $range2 = $hunk->context_range(2, $file_offset2);
-
- # Print out file 1 part for each block in context diff format if there are
- # any blocks that remove items
- print "*** $range1 ****\n";
- my $low = $hunk->{"start1"};
- my $hi = $hunk->{"end1"};
- if (@blocklist = grep {$_->remove} @{$hunk->{"blocks"}}) {
- my @outlist = @$fileref1[$low..$hi];
- map {s/^/ /} @outlist; # assume it's just context
- foreach my $block (@blocklist) {
- my $op = $block->op; # - or !
- foreach my $item ($block->remove) {
- $outlist[$item->{"item_no"} - $low] =~ s/^ /$op/;
- }
- }
- map {s/$/\n/} @outlist; # add \n's
- print @outlist;
+# Set the pointer to the appropriate diff function.
+#
+# Note that in either case the function determines how many lines to
+# discard from the front of each lookahead buffer to resync the
+# streams, then prints the appropriate diff output and discards them.
+# After the function returns, it should always be the case that
+# $lines1[0] eq $lines2[0].
+my $find_diff = $use_complexdiff ? \&complex_diff : \&simple_diff;
+
+# The main loop.
+while (1) {
+ # keep lookahead buffers topped up
+ fill($fh1, \@lines1);
+ fill($fh2, \@lines2);
+
+ # peek at first line in each buffer
+ my $l1 = $lines1[0];
+ my $l2 = $lines2[0];
+
+ if (!defined($l1) && !defined($l2)) {
+ # reached EOF on both streams: exit
+ exit(1);
}
- print "--- $range2 ----\n";
- $low = $hunk->{"start2"};
- $hi = $hunk->{"end2"};
- if (@blocklist = grep {$_->insert} @{$hunk->{"blocks"}}) {
- my @outlist = @$fileref2[$low..$hi];
- map {s/^/ /} @outlist; # assume it's just context
- foreach my $block (@blocklist) {
- my $op = $block->op; # + or !
- foreach my $item ($block->insert) {
- $outlist[$item->{"item_no"} - $low] =~ s/^ /$op/;
+ if ($l1 eq $l2) {
+ # matching lines: delete from lookahead buffer
+ shift @lines1;
+ shift @lines2;
+ # figure out what to do with this line
+ if ($postcontext > 0) {
+ # we're in the post-context of a diff: print it
+ print ' ', $l1;
+ $lineno1++;
+ $lineno2++;
+ if (--$postcontext == 0) {
+ STDOUT->flush();
+ }
+ }
+ else {
+ # we're in the middle of a matching region... save this
+ # line for precontext in case we run into a difference.
+ push @precontext, $l1;
+ # don't let precontext buffer get bigger than needed
+ while (@precontext > $precontext_lines) {
+ shift @precontext;
+ $lineno1++;
+ $lineno2++;
}
}
- map {s/$/\n/} @outlist; # add \n's
- print @outlist;
}
-}
-
-sub context_range {
-# Generate a range of item numbers to print. Only print 1 number if the range
-# has only one item in it. Otherwise, it's 'start,end'
- my ($hunk, $flag, $offset) = @_;
- my ($start, $end) = ($hunk->{"start$flag"},$hunk->{"end$flag"});
-
- # index from 1, not zero
- $start += $offset + 1;
- $end += $offset + 1;
- my $range = ($start < $end) ? "$start,$end" : $end;
- return $range;
-}
-
-sub unified_range {
-# Generate a range of item numbers to print for unified diff
-# Print number where block starts, followed by number of lines in the block
-# (don't print number of lines if it's 1)
- my ($hunk, $flag, $offset) = @_;
- my ($start, $end) = ($hunk->{"start$flag"},$hunk->{"end$flag"});
-
- # index from 1, not zero
- $start += $offset + 1;
- $end += $offset + 1;
- my $length = $end - $start + 1;
- my $first = $length < 2 ? $end : $start; # strange, but correct...
- my $range = $length== 1 ? $first : "$first,$length";
- return $range;
-}
-} # end Package Hunk
-
-# Package Block. A block is an operation removing, adding, or changing
-# a group of items. Basically, this is just a list of changes, where each
-# change adds or deletes a single item.
-# (Change could be a separate class, but it didn't seem worth it)
-{
-package Block;
-sub new {
-# Input is a chunk from &Algorithm::LCS::diff
-# Fields in a block:
-# length_diff - how much longer file 2 is than file 1 due to this block
-# Each change has:
-# sign - '+' for insert, '-' for remove
-# item_no - number of the item in the file (e.g., line number)
-# We don't bother storing the text of the item
-#
- my ($class,$chunk) = @_;
- my @changes = ();
-
-# This just turns each change into a hash.
- foreach my $item (@$chunk) {
- my ($sign, $item_no, $text) = @$item;
- my $hashref = {"sign" => $sign, "item_no" => $item_no};
- push @changes, $hashref;
+ else {
+ # Mismatch. Deal with it.
+ &$find_diff();
}
-
- my $block = { "changes" => \@changes };
- bless $block, $class;
-
- $block->{"length_diff"} = $block->insert - $block->remove;
- return $block;
}
-
-
-# LOW LEVEL FUNCTIONS
-sub op {
-# what kind of block is this?
- my $block = shift;
- my $insert = $block->insert;
- my $remove = $block->remove;
-
- $remove && $insert and return '!';
- $remove and return '-';
- $insert and return '+';
- warn "unknown block type";
- return '^'; # context block
-}
-
-# Returns a list of the changes in this block that remove items
-# (or the number of removals if called in scalar context)
-sub remove { return grep {$_->{"sign"} eq '-'} @{shift->{"changes"}}; }
-
-# Returns a list of the changes in this block that insert items
-sub insert { return grep {$_->{"sign"} eq '+'} @{shift->{"changes"}}; }
-
-} # end of package Block
projects / gem5.git / blobdiff